The attitude to jacks among motorists is different: someone considers him an ordinary piece of iron, someone sees in him an assistant who has helped out more than once in critical situations, someone is a "instrument of torture", they say, "... it's hard to lift and lower , and besides, you will rip your hands off the asphalt ... ”.
Each - his own, but much depends on the type of jack and the ability to handle it correctly.
For example, my first acquaintance with an ordinary screw jack did not bode well. The "harmful tool" strove to rip off the sides of the car, which he finally achieved, leaving another "battle scar" on the wing of the already battered Zhiguli. But after a while, either his conscience woke up, or I became more careful, but the relationship between us improved and complete "mutual understanding" came about. Now, while “pumping up the muscles” with a rhombic jack, I increasingly remember the “old friend” who easily raised and lowered the car.
But from nostalgia to business.
To begin with, we will consider the main characteristics, advantages and disadvantages of certain types of jacks, that is, everything you need to know when choosing this important car accessory.
MAIN FEATURES OF JACKS
Lifting capacity - the maximum effort developed by the jack (indicated in kilograms or tons).
Pick-up is the part of the jack designed to rest against the car. It can be made in the form of a folding rod (for screw and most rack and pinion) or a rigidly fixed bracket called a lifting heel (hydraulic, rhombic, etc.).
Support platform - the lower supporting part of the jack. There are two requirements for it. The first is to prevent lateral sliding (achieved through the shape of the surface). The second is to ensure minimal indentation into the ground at a given load capacity.
The minimum (initial) pickup height is the smallest vertical distance from the support platform to the pickup in its lower working position.
Maximum lift height - the greatest vertical distance from the support platform to the pickup when lifting the load to full height.
Maximum working stroke - the greatest vertical movement of the pick-up from the bottom to the top position.
The force on the drive handle is the force that must be applied when lifting the load. This parameter depends on the weight of the vehicle being lifted and the type of jack. In some species, it changes during the ascent.
Stability is the ability of the jack to maintain its working position when forces tend to move the vehicle in the longitudinal or transverse direction. These forces can occur if the jack is incorrectly installed (tilted), due to a slope in the road or a strong gust of wind.
Stability mainly depends on the area of the support part and how rigidly it is connected to other parts of the jack.
Versatility - adaptability of the jack for lifting vehicles of all types when different ways their settings.
TYPES OF JACKS
Screw jacks
Most motorists call them "Zhiguli", since for more than 30 years it is the screw jacks that have been equipped with rear-wheel drive VAZs, and since 1977 the "extended" version has been included in the Niva toolkit.
The lifting capacity of screw jacks is from 0.5 to 1 ton. A steel body and a small-diameter screw act as load-bearing elements. The torque from the drive crank is transmitted to the screw through bevel gears. Depending on the direction of rotation of the handle, the screw raises or lowers the folding grip.
For picking up on the bottom of the car, special eyes are provided, which, due to their unfortunate location, are constantly clogged with dirt, and in winter they also freeze up, which makes it impossible to raise the car.
After several "salty" winters, the eyes can become so weak due to corrosion that when the car is lifted, they will simply burst at the seam, and the car will collapse to the ground. We think it's not difficult to guess what this threatens the driver with. Take care of your hands, gentlemen!
When choosing a screw jack, the owner of "Niva" should pay attention to the marking: jack for "classic" - 2101-3901250 (maximum lifting height 470 mm), for "Niva" and its modifications - 2121-3901250 (maximum lifting height 510 mm). Otherwise, only the front wheels can be replaced with the standard Zhiguli jack on the Niva. This is due to the fact that the rear suspension of the VAZ SUV has a greater free play, and the jack 2101-3901250, raised to the maximum height, will not be able to take the rear wheels off the ground.
ADVANTAGES screw jack: small and stable force on the drive handle, significant working stroke and maximum lifting height, light weight and low price.
LIMITATIONS screw jack: small area supports and, as a result, insufficient stability, large overall dimensions.
Old car models, for example GAZ-21 "Volga", were equipped with such jacks, their carrying capacity was 0.5 and more tons. The main bearing element of the structure is a one-sided toothed rack, along which the ratchet housing moves with a folding pick-up fixed on it. You can change the direction of movement using the up-down switch.
Modern models with a carrying capacity of 2-2.5 tons and more are capable of lifting a car to a height of 1 meter (and this is not the limit!), In addition, due to the presence of special hinges, they can be used as a manual winch. All this was appreciated by off-road lovers who have resigned themselves to a weight of one and a half to two dozen kilograms and meter dimensions of rack and pinion jacks.
ADVANTAGES: long stroke and maximum lift height, constant force throughout the entire stroke.
LIMITATIONS: impressive weight and dimensions (especially in modern models).
Post-screw jacks
Such jacks are used mainly for Gazelles and UAZ vehicles, and their carrying capacity ranges from 0.8 to 3 tons.
There are two supporting elements, this is a body and a large-section screw. By design, post-screw jacks are divided into single-screw and twin-screw.
The principle of operation of single-screw jacks is as follows: the drive handle rotates the support nut relative to the body through a bevel pair of gears, pushing the screw with a lifting heel. For twin-screw screws, the support nut is the body itself. A second screw with a larger thread in the other direction is screwed into the screw with a large diameter. The rotation of the drive handle is transferred through the ratchet mechanism to the large diameter screw, and it is extended from the housing, while another screw is extended from it, increasing the lift height.
ADVANTAGES: structural rigidity, good stability.
LIMITATIONS: high weight and initial lifting height, low lifting height (for single-screw).
They are used in front-wheel drive VAZs of the "eighth" family. Although such jacks can be called universal, since they can be used to lift almost any vehicle, the mass of which does not exceed 1 ton (carrying capacity is not more than 0.7-0.8 tons).
Carrying elements: power screw and two levers (upper and lower).
On the top there is a pickup and a screw nut, and on the bottom there is a hinged stop for the screw and a support platform.
The principle of operation is as follows: rotation of the drive handle increases the angle between the lower arm (with the support platform) and the upper arm (on which the pick is located), thereby providing lifting.
ADVANTAGES: light weight and initial lifting height, large working stroke.
LIMITATIONS: poor stability and insufficient rigidity of the structure, increased effort on the handle at the beginning of the ascent.
Hydraulic jacks
They can be called "heavy artillery" - carrying capacity from 1 to several hundred tons. This leads to their use in the repair of trucks and other heavy equipment. By design, they are divided into single and multi-plunger.
The main bearing elements are the body, the extendable piston (plunger) and the working fluid (usually oil). The housing has two functions: it is a piston guide cylinder and a reservoir for the working fluid. A screw with a lifting heel is screwed into the plunger, thus, by unscrewing the screw, it is possible, if necessary, to increase the maximum lifting height.
The force from the drive handle is transmitted through the lever to the pressure pump. When moving upward, the liquid from the reservoir is sucked into the pump cavity, and when pressed, it is pumped into the cavity of the working cylinder, pushing the plunger. Backflow of liquid is prevented by valves (suction and discharge). To lower the load, it is necessary to unscrew the shut-off needle, while the liquid is displaced from the pump cavity back into the reservoir.
For all their might, hydraulic jacks are some of the most demanding. So, for example, to maintain the jack in working order, it is necessary to regularly monitor the oil level, monitor the tightness of the oil seals and valves. Such a jack can only be transported and stored in an upright position, otherwise the working fluid (oil) may leak out of the reservoir.
ADVANTAGES: structural rigidity, good stability, little force on the drive handle
LIMITATIONS: large weight and initial lifting height, complex device, small working stroke (for single-plunger), high cost.
In stores you can find two types: mechanical (screw) and hydraulic. Mechanical jacks of this type were used at one time in front-wheel drive vehicles "Moskvich".
Carrying capacity ranges from 0.7 to 2 tons.
As load-bearing elements in this design, four articulated levers are used, forming a rhombus (hence, in general, the name).
The load is lifted by changing the angles between the levers, which accordingly leads to an increase / decrease in the distance between the pick-up and the support platform.
ADVANTAGES: structural rigidity, large bearing surface, versatility.
LIMITATIONS: low working stroke, increased effort on the drive handle (for mechanical), high cost and high weight (for hydraulic).
This is a kind of symbiosis of lever and rhombic jacks. At present, they are being used in a family of VAZ "dozens". Compared to lever jacks, these jacks have a slightly higher carrying capacity - about 1 ton, and the principle of operation is practically the same.
ADVANTAGES: small starting height and weight, compactness (if desired, the jack can fit into a 13-inch "spare wheel").
LIMITATIONS: poor stability, increased force on the drive handle, low structural rigidity.
This is a purely garage or service equipment, it is not worth using it on the road (and even more so on a slope), there is a high probability of a jack breakdown. Carrying capacity from 2 tons or more.
In fact, it is a hydraulic jack of a modified design: a low steel body on small wheels, from which a lever with a lifting heel is extended by a plunger. As a rule, for the convenience of work, they are equipped with a long drive handle, due to which the applied force is reduced and it becomes possible to perform all operations with the jack while standing.
ADVANTAGES: good stability, low initial height, structural rigidity, low effort on the drive handle.
LIMITATIONS: high cost, the ability to work only on a flat and hard surface, large weight.
It is worth considering that we have considered only the basic designs of jacks, and if we talk about professional equipment, then there are also such: rolling pneumatic (well suited for work in tire shops), combined bottle (hydraulics / pneumatics), rolling two-level, hydraulic hook-on, wagon etc.
TEST PROCEDURE
We decided to test jacks according to “ full program". First, we define the basic geometric characteristics: the minimum (initial) pickup height (H min), the maximum lift height (H max) and the maximum working stroke (L max). Secondly, we will measure the force on the drive handle (kg) at the beginning / middle / end of the lift. Next, we will assess the stability of the car on each jack (on a five-point scale). Finally, we will weigh and determine the overall dimensions (length / width / height) according to the maximum values.
The tests were carried out on a VAZ-2112 car (own weight 1.01 tonnes), GOODYEAR Ultra Grip 400 rubber, dimension 175 / 70R14. The surface under the seating platform is firm and level (concrete).
It should be noted that some models of jacks were installed directly under the "flanging" of the car's bottom, which increased H max by 10-15 mm, while the design of the lifting heel of others did not allow this.
USEFUL TIPS
And finally, a few useful tips, which will help to avoid troubles when working with jacks and forced repairs on the road.
... If a malfunction catches you on the road (for example, a flat tire), then turn on the hazard warning lights and, gradually slowing down, look for an area with an even and hard (as far as possible) surface for repairs. In the city, do not park your car near an intersection or traffic light, it is better to drive a few meters on a flat tire than cause an accident. After stopping the car (in accordance with clause 7.2 of the SDA of the Russian Federation), it is necessary to put up an emergency stop sign behind the car at a distance of at least 15 m in settlements and at least 30 m outside settlements. After that, you can safely proceed to troubleshooting.
... It is advisable to start dismantling a flat tire with the preparation of the necessary tool, a jack and a spare wheel. Then, fixing the wheel, located diagonally from the wheel to be replaced, with wheel chocks in both directions, install the jack (without lifting the machine!) And make sure that it stands level, without skewing. Next, loosen the wheel fasteners (nuts or bolts) and begin to smoothly raise the car, while observing the longitudinal displacement of the body, and at the slightest hint of it, lower and reinstall the jack. When the distance between the suspended wheel and the ground reaches 30-50 millimeters, unscrew the fasteners, remove the deflated wheel and install a new wheel. After finishing the repairs and putting the car on "all four", do not forget to finally tighten the fasteners and measure the tire pressure.
... If you are working with a jack in the garage, then after lifting the car, be sure to place additional supports (tripods, blocks, etc.) under the load-bearing elements of the body.
It is strictly forbidden to work under a vehicle that is only on a jack!
... As the proud owner of a car trailer, make sure that your car jack has sufficient maximum lift to lift its wheel if necessary.
Rhombic jack
In our opinion, this is a worthy representative of the family of rhombic jacks, devoid of many of the shortcomings of its "relatives".
The structural elements of the structure inspire confidence, while the jack is compact and lightweight, so there will be no problems with its placement in the car. The profile of the lifting foot makes it possible to substitute it under the "flange", increasing the maximum lifting height. The length of the removable drive handle is 470 mm, and the length of the lever is 150 mm, which significantly reduces the applied force and allows you not to injure your hands when working (which is usually the case with rhombic jacks with a folding non-removable handle). The jack hung out the front wheel of the car by 70 mm (if necessary, 30-50 mm). We gave a solid “four” for stability, and although the testing took place in almost “ideal” conditions, this hero will not let you down on the road.
The jack is packed in a cardboard box, which is likely to be short-lived. There are no instructions in Russian. A sticker on one of the levers reads ( English): “When changing wheels, you must put the car on the handbrake and block the wheels located on the opposite side of the replaced one. Do not exceed the permissible load - 1 ton. "
PRICE: Moscow average $ 9.5.
A worthy replacement for the standard jack "Zhiguli", "Samar" and "Lad". It is more comfortable, more stable and more beautiful. If handled correctly, it will serve you for more than one year, it is a pity that there is no transport bag or cover.
Combined lever-screw jack
A combined jack should combine all the advantages of a lever and rhombic jack, it is, but it would not hurt to get rid of the shortcomings. Until then ...
The support platform and the heel are made on hinges, therefore, by rotating the handle, it is necessary to control their position. Problems arise on uneven surfaces with correct installation. When raising and lowering the car, you need to monitor the level of the handle, otherwise your fingers will meet the asphalt, which is unpleasant. The maximum lifting height is 400 mm, the suspended wheel is lifted off the ground by 105 mm! However, this is not all that this jack is capable of; if desired, it can be "tightened" up to 420-430 mm. But we do not recommend experimenting - the probability of a car falling is high. Already in the middle of the ascent, the vibrations from the rotation of the drive handle rock the car quite strongly. Another nuance - when the lift height reaches 430 mm, the rear wheel (from the side of the suspended front wheel) will lift off the ground by 50 mm. And given the poor stability of the combined jack, it is very dangerous, a gust of wind or careless installation of the wheel - and the car will collapse to the ground.
The advantages of the jack include its compactness (fits into a 13-inch spare tire) and lightness. The design is quite rigid and, if the jack is not overloaded, then it will cope with its task.
PRICE: Moscow average $ 4.5.
Large maximum lift heights, small dimensions and weight are counterbalanced by poor stability and an awkward drive handle. The jack has a carrying case, but no instructions. One of the main advantages is the very low price.
Hydraulic bottle jack
In fact, the jack can lift the car by 380 mm, but it had to be installed in a place under the bottom, where the "paws" of the lifts at the service station are usually brought. And they are in a depression, so the lifting height has decreased. We do not recommend installing a jack directly under the flange - the area of the lifting heel is like that of a five-ruble coin. However, even at the same time, he raised the suspended wheel to the required 35 mm from the ground. Despite the diminutiveness of the lifting heel, the car is not in danger of falling - the jack is stable like a tank. It is convenient and easy to use. The folding telescopic handle, approx. 310 mm long, also serves as a key to the control valve. The only requirement is to store and transport the jack in an upright position, for this it is enough to put it in a compact plastic case with a convenient handle and put it in the trunk.
PRICE: Moscow average $ 18.5.
Disadvantages of a hydraulic jack are the need for maintenance and a large initial lifting height. But a student can easily cope with TO, especially since the whole process is described in detail in the instructions in Russian. It also contains detailed explanatory diagrams, signs, causes and troubleshooting methods. For most domestic cars, such a jack will fit with a margin of a few millimeters.
Excellent stability, comfortable handle, large carrying capacity (with small dimensions), comfortable case - all these are the advantages of this jack.
Hydraulic sliding jack
Such a hydraulic trolley jack is ideal for operation in a garage (in a garage, not in a service station). Four metal castors make it easy to move without lifting. A 360-degree pivot handle helps you operate the jack from any convenient side. The model under test has a so-called pre-lift lever, which allows, within 1-2 seconds, to set the lifting heel directly to the height required to start lifting (ie, in our case, under the car's bottom). After that, you can start working with the pump plunger. The maximum lift height can be increased by 93 mm (543 mm) by installing a special spacer (supplied) under the lifting foot. We didn’t use it, and indeed we raised the car only by 410 mm, while the hanging front wheel rose by 115 mm, and the rear one almost lifted off the ground. Although there is no need to worry about the stability of the car - it stands like a glove. The 625 mm long drive arm is fitted with an anatomically rubberized handle and also acts as a key for the control valve. With enough skill, you can install a jack under the rear beam or axle and hang out two wheels at once, since the carrying capacity of three tons allows you to do this. But this is inconvenient with a standard drive arm.
PRICE of a hydraulic trolley jack: average in Moscow is $ 79.
If you love repairing your car or are just trying to keep an eye on its technical condition, then this hydraulic rolling jack will be your reliable assistant. Of course, you can take it with you in the car, but, firstly, it is quite large (in the scale of the trunk), secondly, heavy, and thirdly, it is difficult to install it correctly on the side of the road. So it's better to use something simpler on the way.
Combined pneumatic / hydraulic bottle jack
The ease with which the car "soared up" was simply amazed (this is easy to explain, because the pneumatic jack is designed for 12 tons, but only 1010 kg had to be lifted). But it is inconvenient to use such a jack as a road jack. His lot is work in stationary conditions, where his main advantage will be revealed - the possibility of using compressed air for lifting energy. You just need to connect a pneumatic jack through a special connector to the compressor and press the lever for supplying pressure to the receiver - the air will do the rest for you. In this case, you can forget about the drive handle of the hydraulic pump, especially since the shape of the control valve allows you to open and close it by hand, without a key.
PRICE of a pneumatic jack: Moscow average $ 127.
Ideal for tire shops and service stations. It makes no sense for a car enthusiast to buy it, since in the conditions of an ordinary garage it will not be possible to realize all the possibilities of the jack.
- There is a legend that in ancient times the jack was used in hostilities as a tool used to break the gates to the besieged city. For this reason, the design of the jack was classified. According to legend, the jack structure was sold (one of the first cases of espionage known to history). According to another version, a wandering artist painted a portrait of a nobleman who was leaning on a jack. After that, the artist reproduced the drawing and transferred (or sold) it to the warring side.
- The idea of creating the world's first hydraulic car lift was born by accident. Its author - Peter Lunati, who was engaged in car repair, during a visit to the hairdresser saw how the master easily fixed the chair at the desired height. Less than a year later, in 1925, Lunati manufactured a car platform lift with a central hydraulic stand, powered by a hydraulic unit with a hand pump.
see also
|
||||||||||||||||||||||||||
Write a review on the article "Jack"
Excerpt from the Jack
Remaining fenced off from any communication, I spent my days in the complete "silence of loneliness." Until, finally, unable to bear it any longer, she went down to the basement again ...The room I found Morone in a month ago was empty this time. One could only hope that the brave cardinal was still alive. And I sincerely wished him luck, which, unfortunately, was clearly lacking for the prisoners of Karaffa.
And since I was already in the basement anyway, after a little thought, I decided to look further, and carefully opened the next door ...
And there, on some terrible torture "instrument" lay a completely naked, bloody young girl, whose body was a real mixture of live burnt meat, cuts and blood that covered her from head to toe ... more - Karaffy, fortunately for me, was not in the torture room.
I quietly walked over to the unfortunate woman and gently stroked her swollen, tender cheek. The girl groaned. Then, carefully taking her fragile fingers in my palm, I slowly began to "heal" her ... Soon, clean, gray eyes looked at me in surprise ...
- Quiet, dear ... Lie still. I will try to help you as much as possible. But I don’t know if I’ll have enough time ... You were tortured very much, and I’m not sure if I can quickly "patch" it all. Relax, my dear, and try to remember something kind ... if you can.
The girl (she turned out to be quite a child) groaned, trying to say something, but for some reason the words did not work. She bellowed, unable to pronounce even the shortest word clearly. And then an eerie understanding flashed through me - this unfortunate woman had no language !!! They pulled him out ... so she wouldn't say too much! So that she would not shout the truth when they burn at the stake ... So that she could not say what they did to her ...
Oh my God! .. Is it really PEOPLE doing all this ???
Slightly calming my dead heart, I tried to address her mentally - the girl heard. Which meant she was gifted! .. One of those whom the Pope hated so fiercely. And who so brutally burned alive on their terrifying human bonfires ...
- What did they do to you, dear?! .. Why did they take away your speech ?!
Trying to tighten the rough rags that had fallen from her body higher with disobedient trembling hands, I whispered in shock.
- Do not be afraid of anything, my dear, just think what you would like to say, and I will try to hear you. What's your name, girl?
- Damiana ... - the answer whispered softly.
- Hold on, Damiana, - I smiled as gently as possible. - Hold on, don't slip away, I'll try to help you!
But the girl just shook her head slowly, and a clean, lonely tear rolled down her battered cheek ...
- Thank you ... for the kindness. But I'm not a tenant already ... - her quiet "mental" voice rustled in response. - Help me ... Help me "go away." Please ... I can't take it anymore ... They'll be back soon ... Please! They defiled me ... Please help me to "leave" ... You know how. Help ... I will thank you "there" and remember you ...
She grabbed my wrist with her thin, tortured fingers, grabbing it with a death grip, as if she knew for sure - I really could help her ... I could give the desired peace ...
Sharp pain twisted my tired heart ... This sweet, brutally tortured girl, almost a child, as if for mercy, asked me to die !!! The executioners not only wounded her fragile body - they defiled her pure soul, together they raped her! .. And now, Damiana was ready to “leave”. She asked for death as deliverance, even for a moment, without thinking about salvation. She was tortured and desecrated, and did not want to live ... Anna appeared before my eyes ... God, really, she was waiting for the same scary end? !! Will I be able to save her from this nightmare ?!
Damiana looked at me imploringly with her clear gray eyes, which reflected inhumanly deep pain, wild in its strength ... She could no longer fight. She didn't have the strength to do it. And in order not to betray herself, she preferred to leave ...
What kind of "people" were those who committed such cruelty ?! What kind of monsters trampled our pure Earth, desecrating it with their meanness and "black" soul? .. I cried quietly, stroking the sweet face of this courageous, unhappy little girl, who did not even live a small part of her sad, failed life ... And mine the soul was burning with hatred! Hatred of the monster who called himself the Roman Pope ... the viceroy of God ... and the most holy Father ... enjoying his rotten power and wealth, while in his own terrible basement a wonderful, pure soul was leaving life. She left of her own accord ... Since she could no longer endure the transcendent pain inflicted on her by the order of the same “holy” Pope ...
Oh, how I hated him !!! .. With all my heart, with all my soul I hated! And I knew that I would take revenge on him, no matter what it cost me. For everyone who died so brutally on his orders ... For his father ... for Girolamo ... for this kind, pure girl ... and for everyone else from whom he playfully took away the opportunity to live their dear and only one in this body, earthly life.
- I will help you, girl ... I will help you dear ... - gently lulling her, I quietly whispered. - Calm down, honey, there will be no more pain. My father went there ... I spoke to him. There is only light and peace ... Relax, my dear ... I will fulfill your desire. Now you are going to leave - do not be afraid. You won't feel anything ... I'll help you, Damiana. I'll be with you...
An amazingly beautiful entity emerged from her mutilated physical body. She looked the way Damiana was before she appeared in this damn place.
- Thank you ... - her quiet voice whispered. - Thank you for the kindness ... and for the freedom. I will remember you.
She began to rise smoothly along the luminous channel.
- Goodbye Damiana ... Let your new life will be happy and bright! You will still find your happiness, girl ... And you will find good people. Goodbye...
Her heart quietly stopped ... And the exhausted soul flew away freely to where no one could hurt her anymore. A sweet, kind girl left without knowing how wonderful and joyful her broken, unlived life could be ... how many good people her Gift could make her happy ... how high and bright her unknown love could be ... and how sonorous and the voices of her children who were not born in this life could happily sound ...
Damiana's face soothed in death smoothed out, and she seemed just asleep, she was so pure and beautiful now ... Bitterly sobbing, I sank into a rough sitting next to her empty body ... My heart froze with bitterness and resentment for her innocent, torn life ... And somewhere, very deep in the soul, fierce hatred arose, threatening to break out, and sweep all this criminal, terrifying world from the face of the Earth ...
Finally, somehow gathering myself, I once again glanced at the brave child girl, mentally wishing her peace and happiness in her new world, and quietly walked out the door ...
The horror I saw paralyzed my consciousness, depriving me of the desire to explore the papal basement further ... threatening to bring down on me someone's next suffering, which could be even more terrible. As I was about to go upstairs, I suddenly suddenly felt a weak, but very persistent call. Listening in surprise, I finally realized that my name was from here, from the same basement. And then, forgetting all previous fears, I decided to check.
It is difficult to imagine home renovation without it. Without this device, changing a wheel on the road is almost impossible. With the help of the device, even a child can lift the car, as you might have guessed, we are, of course, talking about a jack.
Before the advent of lifts, jacks were almost the only device that could lift a large load and repair or replace one or another part. Despite the relative simplicity of its design, the jack does its job well and is very popular among motorists. In this article I will try to talk about what jacks are, as well as about how to choose a good jack, having considered the advantages and disadvantages of each of them.
The choice is complicated by a large assortment, it would be much easier for the buyer to have two or three of them, however, in any case, buyers win from the competition of manufacturers. The most important thing is to understand which jack you need and to distinguish a fake from the original. So, let's figure out what you need to pay attention to when choosing a jack.
Carrying capacity
The first is the most important parameter, of course, the carrying capacity. Its performance and, to a greater extent, its price depends on what weight the jack can lift. Agree, what's the difference who released or what color the jack, if it cannot lift what you need. Each device has its own threshold, that is, the maximum weight that can be lifted. Before how to buy a jack be sure to specify the weight of your car, then add about 200-300 kg to this figure, this will be the carrying capacity that you need. The stock is made so that if the car is loaded, your jack does not let you down, for example, there may be things in the trunk or any other cargo that will have to be unloaded if your jack cannot lift your car. A weak jack can not withstand and cause harm to you or your car, or at least fail, as a result, and "money down the drain", and instead of a quick repair, you will have to wait for help or call a tow truck.
Rhombic jack
For owners of passenger cars, a mechanical-type rhombic jack is suitable, with a small margin of carrying capacity of 1.5-2 tons. Such a jack is designed to weigh approximately 1.3 tons, which is equal to the weight of an average sedan. Nobody forbids you to buy a more powerful jack, but it will be a waste of money, since you will never test the true potential of this jack in practice.
Rolling jack
For people who often repair cars or are seriously involved in car repairs, it is very suitable rolling jack, carrying capacity from 3-8 tons. Here the stock will be relevant, since heavier cars may come to you to be "repaired".
Owners of heavy vehicles should take a closer look at jacks with a carrying capacity of 15-30 tons, and more is possible. When buying, you should take into account the carrying capacity of the machine, since a puncture or breakdown can occur exactly at the moment when you are loaded. Example: the weight of a KamAZ car is 10 tons, its carrying capacity is 14 tons, I recommend buying a jack with a carrying capacity of at least 24-28 tons.
Lifting height
This parameter is responsible for the height to which the load is able to lift in relation to the surface on which it stands. Usually 30-50 cm is sufficient for changing a wheel or steering rack. If necessary, you can jack the car higher using various wooden or metal supports, or even buy a rack jack that can lift the car to a height of 1.50 meters above the ground. As a rule, it is necessary to lift this high in exceptional cases, such as when the machine is bogged down in mud or other similar situations.
Rack jack
Pickup height
The pickup height is, in fact, the height of the jack itself. The pickup height is the height from which it is able to start lifting. This point must be taken into account by the owners of cars with low ground clearance (ground clearance). If you buy a jack that is too high or the lifting height is higher than the point you need to raise, then you simply cannot jack the car, even having a very good jack for this. There are really options, you can, for example, make a tunnel or find a flat place with a hole in which you can install such a jack. If the ground clearance of your car is less than 15 cm, I recommend buying a rolling or screw jack, they have a pick-up height of 6-9 cm.
Jack type (drive options)
Mechanical jack
The simplest budget type of jack is mechanical. They have the simplest design - a handle that rotates a threaded steel pin, as a result of which the weight is lifted. Such a jack is suitable for those who rarely use a jack and have impressive physical abilities. This option is hardly suitable for women drivers.
Hydraulic jack
Hydraulic jacks- lifting is carried out due to the oil pressure, which is created in the cylinder when working with the handle. Hydraulic jacks are the most common among motorists because they are very reliable, have excellent performance and are capable of lifting serious weight. And most importantly, for lifting you will not need to make any effort, with "one finger" you can lift a multi-ton machine. Suitable for frequent use.
Pneumatic jacks(pneumatic jacks) - lift by forcing air into the working chamber. For their operation, a source of compressed air is required, for example: a pneumatic network, a gas cylinder or an exhaust pipe. The principle is simple, pressure arises in the chamber, which increases its size, as a result of which there is a rise. No effort is needed to work with such a device, the most important thing is to correctly connect and install the jack in the right place. Such jacks can be found in auto repair shops and service stations, as well as on strings. The pneumatic jack is also an integral part of off-road enthusiasts and all kinds of rallies, with their help the car can be "taken out" from any swamp and mud.
For overall development and consolidating the information received, I recommend looking at the cognitive video how to choose a jack... I will end on this, I hope my advice will help you make a choice and buy a good jack. I would be grateful if you add the article to your social bookmarks. networks or share with friends. Those who wish to supplement my story can do it using the comment form.
Precise positioning of dimensional parts in height, Maintenance cars with the need to lift its body, components and assemblies above the supporting surface require a mechanism specially designed for this purpose called a jack.
This device is familiar to every car enthusiast.
In addition, most of its varieties can be found in service centers and tire changers.
The main purpose of the jack is to raise the load resting on it to a low height.
The operation of the mechanism is most indicative in hydraulic models, where the principle of communicating vessels is the cornerstone and Pascal's law is implemented.
All types of jacks are united by one property - the use of a lever in one form or another during operation.
For hydraulic models, this is, respectively, a hydraulic lever.
At its core, a jack is a technically simple mechanism.
It differs from other lifting devices in mobility and in that it is located directly under the load, and during operation does not require auxiliary devices, for example, chains or ropes.
Used primarily:
- In construction, for example, when lifting parts of a structure, large blocks.
- When repairing cars. It is indispensable when performing tire fitting, where it is used to raise the car body, which allows the wheel to be freed from the weight of the vehicle.
- As a lift for moving, mounting large parts and equipment on supports.
Each type of jack has a unique design, and is created for specific tasks.
Device and characteristics
A classic hydraulic jack consists of the following elements:
- The support base is the sole of the case.
In addition, the design provides for the presence of several valves:
- Pumping valve - responsible for moving the liquid from the reserve tank to the working cylinder, blocking its reverse movement.
- Safety valve - prevents overloading of the jack. Works as a bypass valve in the hydraulic system.
Material
It all depends on the design and lifting capacity of the jack.
Roll-up models for passenger cars often aluminum, while hardened steel and cast iron are used for cargo hydraulic options.
The material and its thickness directly affect the carrying capacity of the mechanism as a whole.
Dimensions, weight and lifting capacity of jacks
The lifting capacity of the jack is its main characteristic, which is determined by the design.
As a rule, the larger the dimensions of this mechanism, the greater its carrying capacity.
So the bottle hydraulic model with a carrying capacity of 2 tons at its low height (on average 150 - 180 mm) weighs 2 - 3 kg.
At the same time, the rack and pinion long version designed for the same carrying capacity can have a height of up to 1 meter or more, and its weight is about 10 - 15 kg.
Everything depends on the design and purpose of the product.
The most lifting jacks among the jacks are hydraulic, where individual models are capable of lifting and holding up to 100 tons.
Screw ones have the smallest carrying capacity - up to 1 ton.
Another characteristic that must be taken into account when choosing is the lifting height of the jack.
It represents the maximum distance between the upper pick-up point and the support of the product.
Is the sum of the following characteristics:
- Pick-up height - the smallest distance between the top pick-up point and the base support. Drawing a parallel with the car - its clearance.
- The working stroke of the rod is the greatest distance between the upper and lower positions of the jack (vertically).
The stroke of the rod directly determines the height to which it is possible to lift the load relative to the original location point.
Types of jacks and their price
According to the principle of operation, the following main types of jacks are distinguished:
Mechanical
A technically simple lifting device, which in most cases is equipped with passenger cars. The work is based on the application of mechanical force to move the working mechanism, for example, a screw pin.
Hydraulic
It works by pumping a fluid into the working cavity, for example, hydraulic oil or brake fluid. The single-valve models are equipped exclusively with a valve that prevents the backflow of fluid, and the two-valve versions are additionally equipped with a bypass safety valve, which prevents damage to the jack itself if the permissible load is exceeded.
Pneumatic
The lifting mechanism is activated by pumping air into its cavity.
Some models are capable of operating on car exhaust gases (connected to the exhaust pipe), while the industrial air version requires efficient compressor equipment.
Electric
It is no longer a kind of jack, but a way of activating the working mechanism. In other words, even mechanical models, where a mechanical force is applied by the motor shaft, can be considered electrical. Some models can be powered by a car cigarette lighter.
Electro-hydraulic
The hydraulics are electrically powered. A vivid example of the previous point. Some models are additionally equipped with a manual drive.
Pneumohydraulic
The hydraulics are powered by an air compressor.
By design, the following types of jacks are distinguished:
Rhombic
The pantograph tool is pure mechanics.
The lifting part resembles a diamond shape, where each side is movably connected to the adjacent one.
Lateral opposite corners are closed by rotation of the pin, because of which the upper and lower corners diverge.
Other names are trapezoidal jack, trapezoid.
Price - from 600 rubles.
Tablet
The hydraulic part in the form of a low-profile cylinder is connected to a separate hydraulic actuator.
The cost starts at 3.5 thousand rubles, and depends on the carrying capacity.
Rack
It is based on a toothed rack along which the lifting mechanism moves. Another representative of mechanics. Price - from 3 thousand rubles.
Klinovoy
The drive can be mechanics or hydraulics.
Another name is the expanding wedge.
The cost is around 10 thousand rubles and more.
Bottle
It got its name from its design with a sharply protruding main working cylinder. The work is mainly based on the hydraulic principle.
Such a jack is often called a telescopic jack, since the rod in its initial position is hidden in a cylinder, literally, like the knees of a telescopic fishing rod.
There is a single-rod and double-rod.
The last option has another name - two-plunger, and it is notable for the fact that the stroke of its rod is twice that of a similar single-piston model.
Sometimes there are three-rod versions.
Price - from 500 rubles.
Lever
At the heart of the design is a rack, which is extended by means of a swinging drive arm.
The cost is 3 thousand rubles and more.
Screw
The rotation of the screw is converted to translational motion lifting platform.
Pulling
Pulling force is used in work. For lifting loads, they are suspended from a solid support.
They are also used for tightening metal structures, parts of the hull of ships. Some models have a hook or other load securing mechanism mounted directly to the stem. The chain version involves fastening the hook (s) to the rod by means of a lug by means of strong chains. The cost often reaches 100 thousand rubles or more.
Movable
The classic design is a lifting arm mounted on a bed with wheels, equipped with a thrust heel. It is driven by a horizontal hydraulic cylinder.
This design is called "frog".
Another option is a scissor mechanism, where the mechanism folds into a body - a bed, like scissors.
On sale there are models with a switch for raising and lowering modes.
A similar mobile jack is used to work with cars, it can be short, medium and long wheelbase, and is selected depending on the depth of the location of the dimes of the vehicle, into which the pickup rests when lifting.
Cost - from 1 thousand rubles.
Jack "Selson"
Pneumatics representative.
This is a kind of pillow with a rubber-cord shell, which increases in height when air is supplied.
Such an inflatable jack is quite expensive - in the region of 30 - 35 thousand rubles.
By appointment, the most popular are the following jacks:
Car ... It is used in car repairs, in tire fitting.
Cable ... Specially designed lifting device for lifting cable drums.
... For lifting freight and passenger wagons, as well as locomotives.
Travel. For lifting individual elements, as well as the assembled structure of the rail-sleeper grid.
The screw version used in the construction of wooden houses and log buildings.
For furniture. A technically simple product in the form of a lever, with the help of which the furniture elements are slightly torn off the floor, and the so-called transport platforms included in the kit are inserted into the formed gap.
Such sets are designed for self-transportation of furniture.
Specialized jacks
The following tools are mainly used in car repairs:
Auto tipper
Designed to lift the car from the side, with an emphasis on the opposite installation of the wheel mechanism.
Repair stand
Also known as a car rack, a device that performs a fall arrest function to additionally hold a car raised by other devices. A support stand for the car prevents it from falling, being rigidly fixed at a given height. Not intended for lifting loads
Transmission rack jack
Used to install and dismantle the vehicle gearbox.
Such a transmission option is a specific and highly targeted equipment.
Yamny
An auxiliary mechanism for hanging the axles of a car on a pit or a scissor lift. Another name is a ditch jack.
By design features, they are distinguished:
- Two stage with two hooks located at different heights. This two-level, bottle-type mechanism combines the classic and low-grip jacks described below.
- With a low paw - has a minimum pickup height, up to 20 millimeters or less. Salient feature- a side-protruding pick-up foot, which picks up the load under its lower edge. Hence another name - a hook jack.
- Low-profile - for lifting cars with low ground clearance.
Exclusively conditionally jacks can be divided into:
- Household - relatively cheap models designed for lifting loads with light weight, in particular - cars. These are the so-called garage jacks - inexpensive mechanisms that allow the production of DIY repair vehicles at home, including wheel replacement. In general, we are talking about budget products.
- Professional - hydraulic reinforced structures designed for fast lifting of light and heavy loads. They are used in modern service centers, repair shops and even in industrial plants. This includes highly specialized models.
Accessories
You can find various accessories for the jack on the free market, for example, a rubber pad for a pickup, a support and an adapter.
The latter consists of two support platforms fixed on a bar, which, in turn, is installed on the rod.
This is a kind of jack “splitter”.
Advantages and disadvantages of different jacks
Each type of jack has its pros and cons, which determine the appropriateness of their use in specific situations:
- Rack and pinion - suitable for working with low-lying loads, but unstable, have a small support area, as well as inconvenient dimensions. To lift the car, the latter must have special recesses in the bottom.
- Rhombic screw - compact when folded, reliable, stable. But they are characterized by a small lifting height.
- Hydraulic - stable, compact and comfortable, they provide quick and easy lifting of the load. In addition, they have a high efficiency factor, have a high load-carrying capacity. But they require regular maintenance, have a short service life, and are not able to lift loads to great heights.
- Pneumatic - easy to operate, stable on any ground. At the same time, the pillows are easily damaged by cutting or sharp objects. When using compressed air, a separate compressor is required.
The choice of a jack should be made based on what tasks you plan to solve with this tool.
Jack(from Dutch. Dommekracht; German Daumkraft, Wagenwinde, Hebe-
winde) – lifting and lowering mechanism supporting
the cargo (structures and equipment) carried on it, on
small height (200-500mm), as well as for shift-
or movement of cargo for insignificant distances
standing, alignment of structures during their installation.
The jack is indispensable in cases where you need to get a lot of effort, mainly used to lift loads of various weight categories.
Interesting Facts. There is a legend that in ancient times the jack was used in hostilities as a tool used to break the gates to the besieged city. For this reason, the design of the jack was classified. According to legend, the jack structure was sold (one of the first cases of espionage known to history). According to another version, a wandering artist painted a portrait of a nobleman who was leaning on a jack. After that, the artist reproduced the drawing and transferred (or sold) it to the warring side.
The idea of creating the world's first hydraulic car lift was born by accident. Its author - Peter Lunati, who was engaged in car repair, during a visit to the hairdresser saw how the master easily fixed the chair at the desired height. Less than a year has passed since 1925 year Lunati manufactured a car platform lift with a central hydraulic stand powered by a hydraulic unit with a hand pump.
Application. Jacks are irreplaceable:
▬ in the everyday life of motorists and car repair shops,
▬ in the work of warehouses and production facilities of various levels.
▬ in the construction industry, jacks are used:
▪ when performing auxiliary work, on the main
installation and repair work when it is necessary to raise
cargo weighing 1000 tons or more to a low height,
usually up to 0.6 ÷ 0.6 m;
▪ also for moving loads horizontally and
verification of structures during their installation;
▪ the jack can also be an integral part of the construction
tel machines and devices.
Dignity jacks:
They are lightweight and easily carried from place to place;
Jacks are experiencing at least once a year.
Classification of jacks... Jacks distinguish between:
but). By appointment:
●- reconciling- for small movements of equipment (10-
40mm) in the design position, which are
are usually screw and less often hydraulic
● lifting- for significant movements of equipment -
Vania (50-350 mm);
b). By design(depending on the specific
application ki - those where the focus is mainly on
is applied to mechanics, and in which they are used
personal fluids or compressed air as
lifting force):
● rack,
● screw,
● hydraulic.
● pneumatic;
a B C D
Fig. 15. Jacks (by appointment):
but - rack and pinion; b - screw; in - hydraulic; r - pneumatic.
The most common are screw jacks, rack and pinion jacks and hydraulic jacks.
in). By mobility:
● stationary,
● portable,
● mobile.
b in
Fig. 16. Jacks (for mobility):
but - stationary; b - portable; in - mobile.
Generally accepted characteristics of jacks:
- lifting capacity- characterizes the maximum possible lifting weight -
my cargo;
- pick-up height- the minimum distance between the supporting surface
(ground, floor) and pickup (jack support point)
in the lower working position, respectively - lower
the edge of the cargo (in the automotive context, this is the clearance);
- lifting height- the maximum distance from the supporting surface to
pickup in the upper working position;
- working stroke- the distance between the lower and upper working position of the
- own weight- weight of the jack in working order;
For some types of jacks, the same characteristic is also relevant gear ratio - for example, the ratio of the plunger area of a hydraulic pump to the area of the lifting plunger in hydraulic jacks.
The effort on the handle of a jack with manual pumping or the power of the electric pump motor depends on it.
General arrangement of jacks.
