Find the working principle and working process of vacuum booster.

The working principle is: vacuum (negative pressure) to increase the driver to apply to the pedal; The working process is: the thrust generated when the vacuum servo air chamber is working, and the pedal force is the same, which directly acts on the brake master cylinder pusher.

Vacuum booster.

The point at which the pressure difference between the servo diaphragm and the servo diaphragm reaches its maximum when the input force is increased to increase the part that uses vacuum (negative pressure) to increase the force exerted by the driver. From this point on, the increase in the output force is equal to the increase in the input force. The vacuum servo chamber is composed of a front and rear shell, and a servo chamber diaphragm is clamped between the two, and the servo chamber is divided into two chambers, front and back.

There are channels A and B on the servo chamber diaphragm seat, channel A is used to communicate the front cavity of the servo air chamber and the control valve, and channel B is used to communicate the rear cavity of the servo air chamber and the control valve. The thrust generated when the vacuum servo chamber is working, like the pedal force, acts directly on the brake master cylinder pushrod.

Extended Information: Mechanism of Action of Vacuum Booster:

1. When the engine is running, step on it.

Brake pedal. Under the action of the actuator, the valve of the vacuum is closed, and at the same time, the air valve at the other end of the actuator is opened, and when the air enters (the cause of the gasping sound caused by pressing the brake pedal), the air pressure in the cavity is unbalanced.

2. Under the action of negative pressure, the diaphragm is pulled to one end of the brake master cylinder, and then the push rod of the brake master cylinder is driven, which realizes the function of further amplifying the leg force.

3. There is only a small pressure difference on both sides of the diaphragm, and due to the large area of the diaphragm, it can still produce a large thrust to push the diaphragm to the end with low pressure.

When the brake is released, the control valve push rod spring 15 makes the control valve push rod and the air valve move to the right, and the vacuum valve leaves the valve seat on the diaphragm seat and opens. The front and rear chambers of the servo air chamber are connected and are in a vacuum state. The diaphragm seat and the diaphragm return under the action of the diaphragm return spring, and the brake master cylinder releases the braking effect.

If the vacuum booster fails or there is no vacuum in the vacuum line, the control valve push rod will directly push the diaphragm seat and the brake master cylinder push rod through the air valve to move, so that the brake master cylinder will generate braking pressure, but the force acting on the pedal will increase.

Basic structure. When vacuum booster does not work, air valve 10 and control valve push rod 12 leave rubber reaction disc 7 under the effect of control valve push rod spring 15, are in right end limit position, and make vacuum valve 9 leave the valve seat on diaphragm seat 8, that is, vacuum valve is in open state.

And the vacuum valve is pressed on the air valve by the valve spring 16 again, that is, the air valve is in the closed state. At this time, the front and rear chambers of the servo air chamber are connected to each other and isolated from the atmosphere. When the engine is working, a certain vacuum level can be generated in the front and rear chambers.

The principle of inhaling air when the engine is working is used to create a vacuum on one side of the booster, and the pressure difference relative to the normal air pressure on the other side, and use this pressure difference to strengthen the braking thrust.

1. If there is a small pressure difference on both sides of the diaphragm, due to the large area of the diaphragm, a large thrust can still be generated to push the diaphragm to the end with low pressure. The vacuum booster system also controls the vacuum entering the booster at the same time when braking, so that the diaphragm moves, and assists manpower to step and push the brake pedal by using the push rod on the diaphragm through the intermodal device.

2. When the engine is turned off, because there is no intake vacuum, there is no power assist, and the artificial force required for braking will be very large. It should be noted here that there are many novices who think that there is no brake when the engine is turned off, which is not true. It should be correct that the engine is turned off, and the manual pedaling force required for braking will become very large because there is no assistance.

The working principle of the vacuum-assisted envy device is as follows: 1. The brake booster pump uses the principle of inhaling air when the engine is working, causing a vacuum on one side of the booster, and a pressure difference is generated relative to the normal air pressure on the other side, and the pressure difference is used to strengthen the braking thrust. Even if there is only a small pressure difference between the two sides of the diaphragm, due to the large area of the diaphragm, a large thrust can still be generated to push the diaphragm to the end with less pressure;

2. In the working state, the push rod return spring makes the brake pedal in the initial position, at this time, the check valve of the connection position of the vacuum tube and the vacuum booster is in the open state, inside the booster, the diaphragm divides it into the true air chamber and the application air chamber, these two air chambers can communicate with each other, both are isolated from the outside world in most of the time, and the air chamber and the atmosphere can be connected by having two valve devices;

3. When the engine is running, press the brake pedal, under the effect of the push rod, the valve of the vacuum is closed, at the same time, the air valve at the other end of the push rod is opened, and after the air enters (the reason for the gasping sound produced by stepping on the brake pedal) will cause the unbalanced state of air pressure in the cavity, under the action of negative pressure, the diaphragm is pulled to one end of the brake master cylinder, and then the push rod of the brake master cylinder is driven, which realizes the function of further amplifying the leg force.

Millions of car purchase subsidies.

Vacuum boosters are an important part of the braking system, and their performance and component damage have a direct impact on the safety of the car. In order to ensure driving safety, the performance and failure of the vacuum booster must be checked regularly and adjusted or replaced in time. In order to facilitate testing and commissioning, it is necessary to understand the structure and working principle of the vacuum booster first.

The structure of the vacuum booster is composed of pistons, diaphragms, return springs, push rods and levers, check valves, air valves and plungers (vacuum valves) and other components, and the form is a single diaphragm vacuum suspension type. The working principle of the vacuum booster is installed between the brake pedal push and the brake main cylinder, which plays the role of assisting the car's braking. Without braking, the diaphragm in the booster is suspended in a vacuum and is balanced by the vacuum and return spring in chambers A and B.

When the driver presses the brake pedal, the brake pedal operating lever makes the plunger move to the left, and at the same time, the air valve also moves to the left under the action of spring thrust, closing the passage of the diaphragm A and B chambers, and opening the air valve. At this time, a pressure difference is generated on both sides of the diaphragm, so that the diaphragm piston moves to the left, and the main cylinder piston is braked through the push rod, so as to realize the function of auxiliary braking. After braking, the force of the brake pedal disappears, the diaphragm is pushed back to the equilibrium position under the slippage of the return spring, the joystick moves to the right, the air valve is closed at this time, the vacuum valve is opened, the passage of chambers A and B is connected, and the two sides of the diaphragm reach the same vacuum degree again, and an effective braking is completed.

In order to ensure the proper operation of the car's brakes, the performance and faults of the vacuum booster need to be checked. Factors such as insufficient vacuum in the intake manifold, leakage or damage in the vacuum line, leakage of diaphragm, and poor closure of the air valve can cause the vacuum booster to operate poorly. Methods such as seal performance checks, auxiliary function checks, vacuum ** checks, vacuum check valves, and vacuum booster air valve checks can be used to ensure proper operation of the vacuum booster.

In addition, when replacing or adjusting the vacuum booster, it is necessary to check the size from the left end of the actuator to the mounting surface of the brake main cylinder to ensure the speed and effectiveness of the brakes. At the same time, when checking the vacuum booster, it is necessary to pay attention to the inspection methods and steps mentioned above to ensure the accuracy of the detection.

The vacuum booster acts on the hydraulic line behind the master cylinder. The brake booster pump, commonly known as the brake booster pump, is in the braking process, controls the vacuum entering the booster pump, makes the diaphragm move, and uses the push rod on the diaphragm to assist manpower to step and push the brake pedal through the intermodal device, so as to amplify the force of the driver pedal. The working principle of the vacuum booster is as follows:

1. The brake booster pump uses the principle of inhaling air when the engine is working, causing a vacuum on one side of the booster, which produces a pressure difference relative to the normal air pressure on the other side, and uses this pressure difference to strengthen the braking thrust. Even if there is only a small pressure difference between the two sides of the diaphragm, due to the large area of the diaphragm, a large thrust can still be generated to push the diaphragm to the end with less pressure;

2. In the working state, the push rod return spring makes the brake pedal in the initial position, at this time, the check valve of the connection position of the vacuum tube and the vacuum booster is in the open state, inside the booster, the diaphragm divides it into the true air chamber and the application air chamber, these two air chambers can communicate with each other, both are isolated from the outside world in most of the time, and the air chamber and the atmosphere can be connected by having two valve devices;

3. When the engine is running, press the brake pedal, under the effect of the push rod, the valve of the vacuum is closed, at the same time, the air valve at the other end of the push rod is opened, and after the air enters (the reason for the panting sound produced by stepping on the brake pedal) will cause the air pressure in the cavity to be unbalanced, under the action of negative pressure, the diaphragm is pulled to one end of the brake master cylinder, and then the push rod of the brake master cylinder is driven, which realizes the function of further amplifying the force of the front of the leg.

Millions of car purchase subsidies.