JP2006258248A - Brake for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein since an auxiliary booster of a brake for a vehicle uses an engine as a power source, braking as the brake is not obtained in stopping of the engine and stopping of the engine during traveling is dangerous. <P>SOLUTION: In the brake for the vehicle, friction force generated by braking is converted to a liquid pressure and braking is obtained by the converted liquid pressure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a self-boosting action in disc brakes and drum brakes that are brakes for vehicles.

Vehicle brakes are roughly classified into disc brakes and drum brakes. Ordinary passenger cars are equipped with disc brakes on the front wheels and drum brakes on the rear wheels. Some passenger cars have disc brakes on all four wheels. Drum brakes are widely installed mainly on large vehicles.

Disc brakes do not have the self-boosting effect found in drum brakes, and the brake pad area, which is a frictional body, is much smaller than the brake shoes of drum brakes. This is because it needs to be pressed with force. For the above reason, sufficient braking cannot be obtained only by the force with which a person steps on the brake pedal.

Therefore, it is common to use an auxiliary pressure booster called a master bag that uses the negative pressure of the engine. The master bag acts on the brake pedal by using the negative pressure generated by the engine during the suction process to ensure braking as a disc brake. The effect is designed so that sufficient braking can be achieved even when the brake pedal is operated with a small force.

It is well known that drum brakes have a self-boosting action. However, in trucks and the like, strong braking is required due to an increase in the vehicle weight and load capacity, and the self-boosting action inherently cannot provide sufficient braking. For this reason, an auxiliary pressure booster such as that found in disc brakes is attached to obtain stronger braking. The auxiliary pressure booster attached to the drum brake is also powered by the engine.
JP 2002-174275 A

The problem with the auxiliary pressure booster represented by the master bag, which is indispensable for vehicle brakes, is that it uses the rotation of the engine. It is an absolute condition that the engine is in the starting state. If the engine stops for some reason, the pressure boosting function will be lost. This means that the brake is not exerted at all in the disc brake, and the braking performance is significantly impaired in the drum brake.

It can be said that this is a very dangerous state, considering that it is not absolutely possible to stop the engine while driving. It also means that you are driving back and forth with such a dangerous situation.
An auxiliary pressure booster such as a master bag has a complicated structure and includes many causes of failure. In particular, the seal and the rubber hose for maintaining the negative pressure are deteriorated due to changes over time, and it is difficult to maintain the function thereof, and sufficient braking may not be obtained even during engine start. In addition, the device itself is expensive and causes a cost increase.

As described above, the object of the present invention is to provide braking as a brake even when the engine is stopped, and at the same time, ensure safety and reduce costs by eliminating equipment related to the auxiliary pressure booster. There is. Therefore, the present invention provides a disc brake having a self-boosting action and a drum brake that exerts the self-boosting action more strongly.
The self-boosting action handled in the present invention does not have the self-boosting action inherent in the drum brake in order to avoid confusion with the self-boosting action inherent in the drum brake.

The vehicle brakes while the vehicle is running, and the brake device works to rotate in the same rotational direction as the wheels due to the frictional force between the friction bodies, and it works very strongly against the part that supports the brake device. The present invention pays attention and has a mechanism for converting the force to be turned into a hydraulic pressure, and is a means for obtaining a self-boosting action by adding to the brake cylinder for operating the friction body by the converted hydraulic pressure, Solving problems related to brakes.

The feature of the present invention is that it pays attention to the force of turning by the frictional force. The force to rotate is very strong against the part that supports the brake device. When converted to hydraulic pressure, there is an advantage that higher hydraulic pressure can be obtained, and self-boosting action is easy. It means that it is obtained. This is due to the synergistic effect of the force to rotate and the hydraulic pressure. The hydraulic pressure that is converted from the initial braking to the strong braking that causes the tire to lock is required to be always higher than the hydraulic pressure from the master cylinder. The given turning force is further increased by the hydraulic pressure and has a self-boosting action, but if this is the case, the tire will eventually lock. Therefore, the present invention also has a mechanism for controlling the hydraulic pressure.

The hydraulic pressure to be converted is determined by the frictional force. Clarify that strong friction force generates high hydraulic pressure, and self-boosting action in vehicle brakes due to the synergistic effect of friction force and hydraulic pressure, and does not depend on engine rotation. .

A means for obtaining a self-boosting action in a disc brake will be described.
The means to convert the force to rotate (hereinafter referred to as frictional force) into hydraulic pressure to press the brake pad (2) is the disc brake body based on the support (12), hydraulic cylinder (10) Obtained from a link mechanism consisting of

The link mechanism will be described from FIG. Attach one end of the disc brake body end to the support (12) in a cantilevered state with a fulcrum pin (13) At this time, the disc brake main body is in a state where it can freely rotate around the fulcrum pin (13).
Similarly, the hydraulic cylinder (10) is fixed to the support (12) in a cantilever manner by the end pin (15). The connecting pin (14) connects the disc brake body and the hydraulic cylinder (10).
The link mechanism constituted as described above is in a state in which the disc brake main body can turn around the fulcrum pin (13) within the stroke range of the hydraulic cylinder (10).

The means for obtaining the self-boosting action is that the disc brake body is pivoted around the fulcrum pin (13) in the direction of the axis (17) by the friction force generated by braking, and is connected to one end of the disc brake body. By compressing the hydraulic cylinder (10) and obtaining hydraulic pressure inside it. This hydraulic pressure is always higher than the hydraulic pressure from the master cylinder.

The fact that the disc brake body turns by frictional force means that the turning of the disc brake body changes from the state shown by the broken line to the state shown by the solid line from FIG. In the cross-sectional view of FIG. 4, it refers to a change from (a) to (b).
The action point (16) is displaced by the action point displacement (26) in the direction of the axis (17) in accordance with the turning amount.

The state represented by the broken line represents the turning limit, but the actual operation does not turn so far. In this state, there is no compression of the hydraulic cylinder (10), and no hydraulic pressure is generated. Therefore, a self-boosting effect cannot be obtained.

The hydraulic pressure from the hydraulic cylinder (10) is added to the pipeline 2 (23) from the master cylinder (28) via the pipeline 3 (24) and the pressure control valve (18), and the brake pad (2) Self-boosting action is obtained by pressing more strongly. The increase in the hydraulic pressure in the hydraulic cylinder (10) is due to an increase in frictional force. Due to the synergistic effect of hydraulic pressure and frictional force, a stronger pressing force can be applied to the brake pad (2), and self-boosting action is exhibited.

In order for the disc brake body to pivot in the direction of the axis (17) about the fulcrum pin (13) by frictional force, the position of the action point (16) and the position of the fulcrum pin (13) are important.
The condition is that the position of the fulcrum pin (13) is more in the outer circumferential direction than the action point (16) with respect to the shaft core (17).
In order for the disc brake main body to obtain a larger turning force, it is important to set the position of the fulcrum pin (13) in the outer peripheral direction and secure the distance from the action point (16).

The means for obtaining the self-boosting action according to the present invention has the following reasons for turning the disc brake body in the axial direction.
As described above, it is important to secure the distance between the fulcrum pin (13) and the action point (16) in order to obtain the self-boosting action. However, when the disc brake body turns, the action point (16) also changes. It will be displaced in the axial direction. That is, the distance between the fulcrum pin (13) and the action point (16) can be increased simultaneously with the turning. This means that the turning force increases as the turning proceeds.

Conversely, it is possible to set the turn in the outer circumferential direction, but as the turn proceeds, the distance between the fulcrum pin (13) and the action point (16) becomes smaller, and as a result, the turning force becomes weaker. For the above reasons, in the present invention, the turning direction is the direction of the axis (17), and the turning force increases as the turning proceeds.

A means for obtaining a self-boosting action in the drum brake will be described.
In FIG. 5, braking while the vehicle is running means that friction is generated on the sliding surfaces of the brake drum (41) and the brake shoes (42, 43) which are friction bodies of the brake device. means.
This friction acts as a force that the entire brake device tries to rotate in the same direction as the rotation of the wheel, and the braking is secured by fixing the back plate (40) to which the brake device is attached to a part of the vehicle. .

Since the force to rotate due to the frictional force acts very strongly on the brake shoes (42, 43), the portion supporting the brake shoes is firmly fixed to the back plate (40).
As described above, the present invention pays attention to the frictional force and has a mechanism for converting into a hydraulic pressure for spreading the brake shoe in the drum brake.

The means for converting the frictional force into hydraulic pressure to spread the brake shoes (42, 43) is that the hydraulic cylinder (49) is attached to the back plate (40), and the brake shoes (42, 43) are It is obtained by compressing the hydraulic cylinder (49).

The operation of the hydraulic cylinder (49) when the brake drum (41) rotates counterclockwise from FIG. 6 will be described.
The hydraulic pressure to obtain the self-boosting action is that the brake shoe (42, 43) is rotated in the same rotational direction as the brake drum (41) by the frictional force generated by braking, and at one end of the brake shoe (42). It works in the direction of compressing the piston L (51) of the hydraulic cylinder (49).

At this time, hydraulic pressure is generated inside the hydraulic cylinder (49). By adding this hydraulic pressure to the brake cylinder (48) from the pipe (24), a self-boosting action is obtained.
A strong friction force generates a high hydraulic pressure and obtains stronger braking. This can provide a self-boosting action due to the synergistic effect of frictional force and hydraulic pressure.

The vehicular brake having a self-boosting action according to the present invention does not require an auxiliary pressure boosting device and can be eliminated. As described above, the auxiliary booster is indispensable in the conventional vehicle brake. However, in order for the auxiliary booster to perform its function, it is an absolute condition that the engine is being started. Stopping the engine meant that braking as a brake was not performed.

According to the vehicle brake having a self-boosting action according to the present invention, braking can be obtained regardless of the start and stop of the engine, and therefore the auxiliary pressure booster can be eliminated. The abolition of the auxiliary pressure booster can be expected to sufficiently reduce the production cost. At the same time, the ability to ensure braking even in the event of an emergency situation where the engine stops while traveling is to ensure the highest priority of safety.

As an effect limited to the disc brake, it is possible to make the wear of each sliding surface uniform.
The self-boosting action according to the present invention is obtained when the disc brake body turns, and the turning amount is determined by the strength of braking, which is a frictional force. If this is applied during actual driving, the force that depresses the brake pedal (30) when braking the vehicle varies in various ways due to various factors.
This means that the amount that the disc brake body turns varies in many ways, and considering the sliding part with the brake pad (2) and brake rotor (9), the sliding position is the same. Will change.

In the conventional disc brake, the sliding surface of the brake rotor (9) rotates, but the distance from the shaft core (17) does not change and the sliding position does not change. In the disc brake according to the present invention, the brake pad (2) turns together with the disc brake body, so that the sliding position changes within the range of the operating point displacement (26). By changing the sliding position, the wear of the sliding surfaces of the brake pad (2) and the brake rotor (9) can be made uniform.

The principle that the wear of each sliding surface can be made uniform according to the present invention can be replaced by the operation of sharpening the blade with a grindstone. If the blade is reciprocated at the same position with respect to the grindstone surface, there will be no less grooves on the blade surface and the grindstone surface. This is the progress of wear in the conventional disc brake. The brake pads (2) and brake rotor (9) were made of uneven materials, and foreign matter was caught.

In order to prevent this, the position of the grindstone surface is changed each time the cutter is reciprocated. By doing so, the blade surface and the grindstone surface are evenly worn. Changing the position of the grinding wheel surface is equivalent to changing the position of the brake pad, and from this principle, wear of each sliding surface of the disc brake according to the present invention can be made uniform.

When the brake pad (2) wears out and reaches the limit of use, it must be replaced. Since the sliding surface of the brake rotor (9) at that time is evenly worn, it is not necessary to align the sliding surface of the brake rotor (9). In the case of a conventional disc brake, the sliding surfaces of the brake rotor (9) are aligned to make a uniform surface.

In addition, when the sliding surface of the brake rotor (9) is evenly worn, it is possible to obtain a beautiful appearance. Many road wheel designs allow the sliding surface of the brake rotor (9) to be seen well. Even in a car with a long mileage, the brilliant sliding surface of the brake rotor (9) beyond the time of a new car can be expected to have a beautiful appearance.

An embodiment in which the present invention is applied to a disc brake will be described.
As shown in FIG. 3, the link mechanism for compressing the hydraulic cylinder (10) by frictional force and obtaining the hydraulic pressure inside is based on the support (12) (generally called steering knuckle). It is formed by a disc brake body and a hydraulic cylinder (10).
The disc brake body is fixed to the support (12) in a cantilevered state with one end at its end being freely movable by a fulcrum pin (13). Since the fulcrum pin (13) receives all of the force received during braking, it is necessary to consider rigidity and wear resistance.

FIG. 3 is a view of the disc brake as viewed from the outer peripheral direction, and the fulcrum pin (13) is represented by a cross section aa.
The end of the disc brake body is fitted into the Y-shaped part of the support (12), and the fulcrum pin (13) is passed through. Fix the fulcrum pin (13) with a stopper. The fulcrum pin (13) is heat-treated and the surface is polished so that strength and wear resistance can be obtained.
The hardened metal 2 (7) is press-fitted into the fulcrum pin hole at the end of the disc brake body where the fulcrum pin (13) is inserted. Also attach Metal 3 (8) in the thrust direction. Lubricant should be applied to the fulcrum pin (13) and both sides sealed.

As shown in FIG. 1, the hydraulic cylinder (10) is attached by fixing one end of the end to the support (12) with an end pin (15) in a freely movable state. Finally, the disc brake body and the hydraulic cylinder (10) are connected by the connecting pin (14) as shown in section bb in FIG.
A spring (11) is provided inside the hydraulic cylinder (10), and has a function of returning the disc brake body from the state of turning by the frictional force to the state before turning. The spring (11) is not limited to the inside of the hydraulic cylinder (10). If the disc brake body returns to its original position from turning, the mounting and shape can be arbitrarily determined.

With the link mechanism configured as described above, the turning amount of the disc brake main body is within the stroke range of the hydraulic cylinder (10). The hydraulic cylinder (10) has a role of a stopper that determines the turning amount of the disc brake body, but it is also possible to arbitrarily provide a turning limit stopper on the support (12). This stopper should be provided even when a hydraulic cylinder is used as a turning stopper if higher safety is taken into consideration.

In order for the disc brake body to pivot about the fulcrum pin (13) in the direction of the axis (17), the position of the point of action (16) where the frictional force acts and the position of the fulcrum pin (13) are important. The condition is that the position of the fulcrum pin (13) is more in the outer peripheral direction than the action point (16) with respect to the shaft core (17). In order to obtain a larger self-boosting action, it is necessary to increase the turning force, which is a means for obtaining the hydraulic pressure.

In order to increase the turning force of the disc brake body, the positional relationship between the position of the fulcrum pin (13), which is the center of turning, and the action point (16) is considered.
The position of the fulcrum pin (13) is preferably in the outer peripheral direction with respect to the shaft core (17). Conversely, the position of the action point (16) should be closer to the axis (17). In other words, how large the distance between the fulcrum pin (13) and the action point (16) can be set is a major factor in determining the turning force.

The position of the action point (16) is almost determined by the size of the brake itself, but the position of the fulcrum pin (13) can be arbitrarily determined to some extent. It can be set in the outer peripheral direction to a position where it does not interfere with the load wheel, and the distance from the action point (16) is increased. On the contrary, it is better to determine the position of the fulcrum pin (13) according to the load wheel, and to determine the position of the action point (16) from which the turning force that is the required hydraulic pressure is obtained.

When the present invention is applied to a motorcycle, the position of the fulcrum pin (13) is not restricted, so that the distance from the action point (16) can be increased, so that a higher hydraulic pressure can be easily obtained. It becomes possible. Originally, since the motorcycle does not have an auxiliary pressure booster, the present invention is most suitable for the motorcycle.
By the above means, the self-boosting action in the disc brake is obtained by obtaining a hydraulic pressure higher than the hydraulic pressure from the master cylinder (28).

FIG. 3 shows the force applied to the disc brake body during braking by arrows (34, 35). When the frictional force is applied, the disc brake body simultaneously applies the rotational force (34) and the torsional force (35). The force (34) in the rotational direction works well because it works at right angles to the fulcrum pin (13), but the force in the torsional direction (35) works in the direction to twist the fulcrum pin (13). A heavy burden is placed on the pin (13), the support (12), and the caliper (1).

Therefore, in the present invention, a tongue-like protrusion (5) is provided at the end of the disc brake body to support the torsional force (35) at the other end of the disc brake body.
Both surfaces of the tongue-shaped protrusion (5) are flat and are fitted in a slidable fitting state to the insertion portion of the support (12), and receive a twisting force (35) acting on the fulcrum pin (13). In addition, there is a metal 1 (6) in the insertion part of the support (12), and wear resistance is taken into consideration.

FIG. 4 shows an embodiment including piping. The hydraulic equipment required to obtain the self-boosting action according to the present invention includes the following. A check valve (20), a pressure control valve (18), and a stop valve (21).
The check valve (20) is installed between the pipeline 1 (22) and the pipeline 2 (23). The check valve (20) is a device that allows flow in only one direction, and the hydraulic pressure generated by the self-boosting is higher than the hydraulic pressure from the master cylinder (28). Do not.

The stop valve (21) attached to the master cylinder (28) is linked to the brake pedal (30). When the brake pedal (30) is depressed, the pipe line in the valve is closed and the brake pedal (30) It is structured to open the valve pipe line by releasing. As with the check valve (20), it works to prevent high hydraulic pressure from flowing back to the master cylinder (28) side. At the same time, when the brake pedal (30) is released, the brake cylinder (3) and hydraulic cylinder (10) It has the function of returning the liquid inside to the reservoir tank (29).

The pressure control pressure valve (18) between the pipe line 2 (23) and the pipe line 3 (24) is for pressure reduction, and controls the pressure generated in the hydraulic cylinder (10) by the self-boosting action. Has a function. The hydraulic pressure in line 3 (24) with self-boosting action is higher than the hydraulic pressure in line 2 (23) from the master cylinder (28), but the self-boosting action is In some cases, the brake may be locked.

The pressure control valve (18) has a function of controlling the strength of the self-boosting action and preventing the brake from being easily locked. Pressure adjustment for that is performed.
In the present invention, the pressure of the pressure control valve (18) is adjusted by the hydraulic pressure from the master cylinder (28). The hydraulic pressure from the master cylinder is added to the pressure adjusting section (19) of the pressure control valve (18) from the pipe (22). The pressure of the pressure control valve (18) is determined by the force of depressing the brake pedal (30), and the strength of the self-boosting action is controlled by the force of depressing the brake pedal (30).

Light braking should be applied when the brake pedal (30) is lightly depressed, and conversely, strong braking can be obtained when the brake pedal (30) is strongly depressed. This is so that braking suitable for human sensitivity can be obtained.

An embodiment in which the present invention is applied to a drum brake will be described.
As shown in FIG. 5, the hydraulic cylinder (49) is attached to the fixed end of the brake shoe (42, 43).
The hydraulic cylinder (49) has all the force required for braking, so it has sufficient strength for mounting, is firmly attached to the back plate (40), and the piston (51, 52) tip is hardened. , Do not wear.

The spring (50) functions to return the pistons (51, 52) to their original positions when the brake is released. Therefore, the spring (50) needs to be set stronger than the return spring (45). From the above configuration, the present invention obtains a self-boosting action in the brake drum.
In the drum brake of the type shown in FIG. 5, the self-boosting action according to the present invention can be obtained in either direction of rotation as indicated by the direction of rotation (39).

FIG. 6 shows an embodiment including piping. The piping equipment required for obtaining the self-boosting action according to the present invention is the same as that of the disk brake described above, and the individual functions also work.
The embodiment of the piping shown in FIG. 7 is different from FIGS. 4 and 6 in that a safety valve (19) is used for pressure adjustment. Basically, it functions to prevent the tire from locking.

In recent vehicle brakes, the ABS (anti-lock brake system) device can automatically eliminate tire locks, so in combination with ABS, ABS functions as pressure control, so pressure adjustment This is an ideal combination because it is not necessary, and ABS is effective for the vehicle brake according to the present invention.

It is a front view which shows the Example in a disc brake. It is sectional drawing which shows the Example in a disc brake. It is a top view which shows the Example in a disc brake. The example of piping in a disc brake is shown. It is a front view which shows the Example in a drum brake. The example of piping in a drum brake is shown. The example of piping in a drum brake is shown.

Explanation of symbols

1. Caliper
2. Brake pad
3. Brake cylinder
4. Brake piston
5. Tongue protrusion
6.Metal 1
7.Metal 2
8.Metal 3
9. Brake rotor
10.Hydraulic cylinder
11.Spring
12.Support
13.fulcrum pin
14.Connecting pin
15.End pin
16. Action point
17.Shaft core
18.Reducing valve
19.Safety valve
20.Check valve
21. Stop valve
22.Pipe 1
23. Line 2
24. Line 3
25. Line 4
26.Working point displacement
27. Hydraulic cylinder compression
28.Master cylinder
29.Reservoir tank
30. Brake pedal
31. Disc brake for front wheels
32. Disc brake for rear wheel
33.Rotation direction
34. Rotational force
35. Torsional force
36. (missing number)
37. (missing number)
38. (missing number)
39.Rotation direction
40.Back plate
41. Brake drum
42. Brake shoe L
43. Brake shoe R
44.Shaft core
45.Return spring
46. Brake piston L
47 Brake piston R
48. Brake cylinder
49.Hydraulic cylinder
50.Spring
51.Piston L
52.Piston R

Claims (5)

When the vehicle brakes while traveling and the brake device acts as a force to turn in the same rotational direction as the wheels due to friction between friction bodies, the force to turn is converted into hydraulic pressure. Brake for vehicles. In the disc brake, one end of the disc brake body end is attached to the support body in a cantilevered manner by a fulcrum pin, the disc brake body is in a state of free swiveling movement around the fulcrum pin, and the hydraulic cylinder is supported by an end pin. 2. A link mechanism comprising a disc brake main body and a hydraulic cylinder is formed by connecting the pin to the end of the disc brake main body with a connecting pin. A vehicular disc brake that obtains hydraulic pressure inside a hydraulic cylinder by rotating a disc brake body in an axial direction and compressing a connected hydraulic cylinder. In the drum brake, a hydraulic cylinder is attached to the brake shoe fixed end side, and the hydraulic cylinder is compressed by the brake shoe by the force of turning to claim 1 to obtain the hydraulic pressure inside the hydraulic cylinder. Drum brake. A vehicular brake that obtains braking by pressing a brake pad in a disc brake, which is a friction body, and pushing a brake shoe in a drum brake by a hydraulic pressure converted from a force to rotate. A vehicular brake having a mechanism for controlling the converted hydraulic pressure, and the hydraulic pressure control is controlled by the hydraulic pressure from a master cylinder obtained by depressing a brake pedal.

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