What is the use of the adjustment arm How to adjust the automatic adjustment arm manually

Because vehicle braking safety is affected by many factors, the adjustment of the brake clearance of drum brakes is of great help to vehicle braking safety, so the automatic adjustment arm has been widely used in passenger and freight vehicles. This article briefly introduces the structure and characteristics of the automatic adjustment arm.

1. Brake clearance adjustment and automatic clearance adjustment.

Brake clearance adjustment refers to the adjustment of the gap between the brake friction pair component - the brake drum and the brake lining. In the process of using the car, frequent braking will lead to the continuous wear of the brake pair components, resulting in the gap between the brake drum and the shoe pads increasing to varying degrees, resulting in the lengthening of the pedal stroke, the thrust of the brake chamber decreased, the braking lag and the braking force decreased.

In order to ensure the safety of the vehicle, maintain the relative stability of the pedal stroke and the balance of the work between the brakes, the brake clearance needs to be adjusted (the adjustment here refers to the adjustment in the process of use), and the adjustment mode is divided into manual and automatic adjustment.

Second, the gap automatic adjustment arm and its characteristics.

With the increase of brake wear and brake clearance, the untimely and random nature of manual adjustment can lead to inconsistent clearance between brakes, prolonged braking response time, wheel deviation, vehicle tail flicking and even brake failure. To solve these problems, the brake clearance needs to be checked regularly and manually adjusted to keep it constant. The clearance adjustment of drum brake is realized by the connecting rod system between the camshaft and the brake chamber - the brake arm, there is a worm gear and worm pair inside the brake arm, and the cam is driven to rotate by adjusting the worm gear to rotate, and the excess clearance between the friction pairs is eliminated.

The automatic clearance adjustment arm is to set an automatic adjustment mechanism in the brake arm to drive the cam to rotate and eliminate the excess braking clearance outside the set clearance between the friction pairs. The gap automatic adjustment arm has the following characteristics:

Ensure that each wheel brake has a constant and consistent braking clearance, so that the braking of the whole vehicle is more sensitive, balanced and effective, shorten the braking distance, even if the thickness of the wheel brake shoe is inconsistent, the degree of wear is different, but also to ensure the best efficiency of braking, which is especially important when the axle comes from different manufacturers, brakes and friction pair materials are different, manual regular adjustment will cause different gaps between brakes due to different wear between different brakes, resulting in uneven braking force distribution.

Reduced braking reaction time and compressed air consumption. Thanks to the elimination of unwanted backlash, the brake chamber applies the brake chamber in the shortest possible strokes and in the best working area, resulting in the best braking efficiency, the shortest braking reaction time and the lowest air consumption.

It is easy to install, easy to use and maintain.

It is to adjust the brakes of the car to make the brakes of the car better.

Open the observation hole on the dust cover, observe the direction of rotation of the adjustment nut that makes the brake clearance smaller, usually clockwise, rotate the nut until there is no clearance, and the resistance is obviously greater when the stop, and then rotate 180 degrees in the opposite direction, and the adjustment is completed.

The adjustment arm is divided into manual adjustment arm and automatic adjustment arm pin. The automatic adjustment arm is designed with different braking clearance values according to the different axle models. In normal use, if the clearance exceeds the limit value, the brake adjustment arm will drive the one-way clutch mechanism inside the drive to adjust the clearance value by one gear when the braking action is completed, so that the brake clearance can be kept within a correct range.

The automatic adjustment arm is generally composed of shell (shell, bushing), transmission part (worm, worm gear), one-way clutch (gear, clutch spring, clutch ring), control device (control panel, control arm, cover plate, rack, return spring) and worm hold-down part (worm coil spring, thrust washer, screw cap, needle roller bearing, worm bearing), etc. After the brake shoe is in contact with the brake drum, the adjustment arm angle hall dissipation due to the elastic deformation of the force transmission parts is not adjusted. (Photo by photo:.)

Pacific Automobile Network Wu Jiahong).

It refers to the automatic brake clearance adjustment arm, referred to as the automatic adjustment arm, which can automatically and timely adjust the clearance increased by wear, so that the brake clearance is always kept within the design range. The angular stroke of the adjustment arm due to the elastic deformation of the force transmission parts after the brake shoe is in contact with the brake drum is not adjusted.

When braking is initiated, the adjustment arm drives the camshaft to rotate the clearance angle and the excess clearance angle, and accurately records the resulting wear. At this time, the cam angular stroke is rough and rough in the clearance area, and the clearance area is characterized by little change in braking torque.

When braking continues, the cam angular travel enters the elastic deformation zone, and the braking torque rises sharply until the car stops. Release the pedal, brake back, braking torque down, cam angle travel back to the clearance zone. According to the excess clearance recorded during braking, the internal adjustment mechanism drives the camshaft to rotate at a certain angle through the worm gear, so as to complete an adjustment.

When there is an excess clearance between the shoe and the brake drum, the camshaft adds the excess clearance "B" angle to the bench calendar during braking, and the adjustment arm slewing stroke at this time can be divided into three parts: normal clearance angle "A", excess clearance angle "B" and elastic angle "C". During braking, the automatic adjustment arm can automatically recognize these three strokes and adjust only the excess clearance.

After using the automatic adjustment arm, the vehicle has the following characteristics when driving:

1. Ensure that the wheels have a constant brake clearance, and the brakes are safe and reliable;

2. The push rod stroke of the brake cylinder is short, and the braking is fast and reliable;

3. Before braking, the push rod of the brake cylinder is always in the initial position to ensure the best braking torque;

4. Make the braking effect of all wheels consistent and stable;

5. Reduce the consumption of compressed air and prolong the life of the air compressor, brake cylinder and other components in the compressed air system;

6. Reduce the consumption of rock mold materials and prolong the service life of brake parts;

7. It is easy to install and use, reduces the number of manual maintenance, and improves economic benefits;

8. The adjustment mechanism is enclosed in the shell and is well protected, so as to avoid moisture, dirt and collision.

The brake adjustment arm has a great impact on the driving safety of the car, so its function must also be vigilant. With the deepening of development, the control mode of the product has gradually been adjusted, roughly including two, one is the manual adjustment arm, the other is the automatic adjustment arm, the functional difference between the two is more obvious, and the value that can be played is also significantly different. In contrast, the application advantages of the latter are more obvious, which can be roughly compared in the following aspects:

1.Guarantee of constant clearance.

The use of this product ensures that the vehicle maintains a constant braking clearance after a period of driving, so that the best braking effect can be guaranteed regardless of the change in the degree of wear.

2.Reduced braking reaction time.

This function can also be greatly achieved by reducing the consumption of compressed air, which is of great significance in ensuring the safety function of the vehicle.

3.Easy to install.

Compared to manual adjustment arm products, the automatic adjustment arm is less difficult to install, which is also its advantage.

4.Brake equalization.

Especially with the increasing number of axles, the brake equalization effect that this product can exert is more prominent.

Manual and automatic adjustment arms are different from the appearance.

The automatic adjustment arm is generally larger, and it will send you a ** directly, you can see that this is the automatic adjustment arm.

This is the manual adjustment arm.

The automatic one is definitely a little more automatic than the manual one, and there is a spring inside, and the elastic force of the spring prompts the turbine to adjust automatically.

The car adjustment arm should be the brake clearance adjustment arm, which is divided into automatic adjustment and manual adjustment.

Most of the domestic truck aftermarket uses manual adjustment arm, because its relatively low cost of automatic adjustment, the aftermarket selling price is relatively cheap.

At present, the manual adjustment arm in the market is divided into different structures, with steel ball structure, and the nut that is adjusted in appearance is 19 squares

As shown in Fig. The other is the most used cleatpiece structural adjustment arm, which adopts the principle of adding an iron card to the outside and not retreating from the worm, the cost is relatively low, the structure is firm, and it is a product that is widely used in the current after-sales market.

Generally, the adjustment arm should be the adjustment arm for braking.

Are you talking about the engine's valve adjustment arm?

Summary. The automatic adjustment arm generally does not need to be manually adjusted, but the quality of most of the automatic adjustment arms on the market is worrying, some will lose their effect, and even some will have a smaller brake clearance or even the phenomenon of wheel dragging. At this time, it is necessary to check whether the adjustment arm is working properly, and you can use a ruler to measure it.

Adjust the brake clearance according to the above method, then let go of the parking brake, step on the foot brake, keep it still, another person needs to measure the push out length of the brake cylinder push rod, the left and right push out length should be the same or almost, if there is an abnormality on one side, you need to pay attention to it.

The automatic adjustment arm generally does not need to be manually adjusted, but the quality of most of the automatic adjustment arms on the market is worrying, some will lose their effect, and even some will have a smaller brake clearance or even the phenomenon of wheel dragging. At this time, you need to check whether the adjustment arm is working properly, and you can use a ruler to measure it. Adjust the braking clearance according to the above method, then let go of the parking brake, step on the foot bridge and brake, keep it still, another person needs to measure the push out length of the brake cylinder push rod, the left and right push out length should be the same or about the same, if there is an abnormality on the thick side, you need to pay attention to it.

Generally, it is not required.