WO2018181783A1

WO2018181783A1 - Vehicle brake

Info

Publication number: WO2018181783A1
Application number: PCT/JP2018/013383
Authority: WO
Inventors: 真吾岩崎
Original assignee: 株式会社アドヴィックス
Priority date: 2017-03-30
Filing date: 2018-03-29
Publication date: 2018-10-04
Also published as: JP2018169038A

Abstract

This vehicle brake is provided with, for example: a strut set for automatically adjusting the gap between two brake shoes; and a strut guide for supporting the strut set movably in the extending direction and for limiting movement of the strut set in a direction intersecting the extending direction.

Description

Vehicle brake

This disclosure relates to a vehicle brake.

Conventionally, there is known a vehicle brake in which a strut set having an automatic adjustment function that suppresses an increase in shoe clearance due to lining wear between two brake shoes (for example, Patent Document 1).

JP 2002-147506 A

This type of vehicle brake is configured so that the overall length of the strut set is increased by rotating an adjuster wheel by an adjuster lever that swings in conjunction with a brake shoe or a piston that drives the brake shoe. In such a configuration, when wear occurs in the lining, the amount of movement of the brake shoe increases, the rotation angle of the adjuster wheel increases, and the length of the strut set increases. As a result, the brake shoe comes close to the drum, so that an increase in shoe clearance due to wear of the lining is suppressed.

However, in this type of vehicle brake, for example, if the position and posture of the strut set change and the desired relative position and relative posture of the adjuster lever and adjuster wheel cannot be obtained, There is a risk that the desired automatic adjustment function by setting may be difficult to obtain.

Therefore, one of the problems of the present invention is to obtain a vehicle brake in which, for example, the automatic adjustment function of the shoe clearance by the strut set is less likely to be impaired.

The vehicle brake according to the present disclosure includes, for example, a back plate, a cylinder that accommodates two pistons that are fixed to the back plate and protrudes by the action of hydraulic pressure, and the two protruding and supported by the back plate. The two brake shoes pressed against the drum that rotates relative to the back plate by each of the pistons, and the first end that can contact one of the two brake shoes and the other can be contacted A rotating portion that extends between the second end portion and is interposed between the two brake shoes and rotates about an axis in the extending direction, and a non-rotating portion that is screwed to the rotating portion. When the pressing member interlocked with the piston or the brake shoe rotates the rotating portion with respect to the non-rotating portion, the amount of movement of the brake shoe is reduced. The strut set is configured to be longer in the extending direction as it increases, and automatically adjusts the distance between the two brake shoes, and supports the strut set to be movable in the extending direction. A strut guide for restricting movement in a direction intersecting the extending direction.

In the above vehicle brake, the strut set position and posture are further stabilized by the strut guide. Therefore, according to such a configuration, for example, the automatic adjustment function of the strut set is less likely to be impaired.

FIG. 1 is a schematic and exemplary side view of the vehicular brake according to the first embodiment from the outside in the vehicle width direction. FIG. 2 is an enlarged view of a part of FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a schematic and exemplary side view of the vehicle brake according to the second embodiment at the same position as in FIG. 2. FIG. 5 is a schematic and exemplary side view of the vehicle brake according to the third embodiment at the same position as in FIG. 2.

Hereinafter, exemplary embodiments of the present invention will be disclosed. The configuration of the embodiment shown below, and the operation and result (effect) brought about by the configuration are examples. The present invention can be realized by configurations other than those disclosed in the following embodiments. According to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

In each figure, for the sake of convenience, the front in the vehicle front-rear direction is indicated by an arrow X, the outer side in the vehicle width direction (axle direction) is indicated by an arrow Y, and the upper side in the vehicle vertical direction is indicated by an arrow Z. .

(First embodiment)
[Configuration of brake device]
FIG. 1 is a side view of the brake device 1 from the outside in the vehicle width direction. The brake device 1 (vehicle brake) is housed inside a peripheral wall (not shown) of a cylindrical wheel. The brake device 1 is a so-called drum brake. The brake device 1 includes two

brake shoes

3L and 3R (3) that are separated from each other in the front-rear direction. The two brake shoes 3 extend in an arc shape along the inner peripheral surface 2 a of the cylindrical drum 2. The drum 2 rotates integrally with the wheel around a rotation center C along the vehicle width direction (direction Y). The brake device 1 moves the two brake shoes 3 so as to come into contact with the inner peripheral surface 2 a of the cylindrical drum 2. Thereby, the drum 2 and the wheel are braked by the friction between the brake shoe 3 and the drum 2. The brake shoe 3 is an example of a braking member.

The brake device 1 includes a disk-shaped back plate 6. The back plate 6 is provided in a posture intersecting with the rotation center C. That is, the back plate 6 extends substantially along the direction intersecting the rotation center C, specifically, substantially along the direction orthogonal to the rotation center C. The back plate 6 directly or indirectly supports each component of the brake device 1. That is, the back plate 6 is an example of a support member. The back plate 6 is connected to a connection member (not shown) with the vehicle body. The connection member is, for example, a part of the suspension (for example, an arm, a link, an attachment member, etc.). The opening 6b provided in the back plate 6 is used for coupling with the connection member. The brake device 1 can be used for both driving wheels and non-driving wheels. In addition, when the brake device 1 is used for driving wheels, an axle shaft (not shown) passes through an opening 6c provided in the back plate 6.

[Brake shoe operation by wheel cylinder]
The brake device 1 includes a wheel cylinder 51 (cylinder) that operates by hydraulic pressure as an actuator that moves the brake shoe 3. The wheel cylinder 51, the brake shoe 3, and the like are disposed outside the back plate 6 in the vehicle width direction. The brake shoe 3 is movably supported on the back plate 6. Specifically, the lower end 3a of the brake shoe 3 is supported by the back plate 6 so as to be rotatable around the rotation center C11. The rotation center C11 is substantially parallel to the rotation center C of the wheel. The wheel cylinder 51 is supported by the upper end portion of the back plate 6. The wheel cylinder 51 has two pistons 52 (see FIG. 3) (not shown) that can project in the vehicle front-rear direction (left-right direction in FIG. 1). The wheel cylinder 51 projects the two pistons 52 in response to the pressurization. The two protruding pistons 52 push the upper end 3b of the brake shoe 3, respectively. Due to the protrusion of the two pistons 52, the two brake shoes 3 each rotate around the rotation center C11 and move so that the upper end portions 3b are separated from each other in the vehicle front-rear direction. As a result, the two brake shoes 3 move radially outward of the rotation center C of the wheel. A belt-like lining 31 along the cylindrical surface is provided on the outer periphery of each brake shoe 3. Therefore, the lining 31 and the inner peripheral surface 2 a of the drum 2 come into contact with each other by the movement of the two brake shoes 3 radially outward of the rotation center C. The friction between the lining 31 and the inner peripheral surface 2a brakes the drum 2 and thus the wheel. The brake device 1 includes

return members

32 and 80. The

return members

32 and 80 move the two brake shoes 3 from the position (braking position) where the two brake shoes 3 come into contact with the inner peripheral surface 2a of the drum 2 when the operation of pushing the brake shoes 3 by the wheel cylinder 51 is released. It moves to a position (non-braking position) that does not come into contact with the inner peripheral surface 2a. The

return members

32 and 80 are elastic members such as coil springs, for example, and force each brake shoe 3 to approach the other brake shoe 3, that is, force away from the inner peripheral surface 2 a of the drum 2. give.

[Function and configuration of strut set]
2 is an enlarged view of a part of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. A strut set 70 is interposed between the two brake shoes 3. The strut set 70 has an end portion 70a and an opposite end portion 70b, and extends substantially along the direction X between the

end portions

70a and 70b. The end portion 70a is in contact with the brake shoe 3L, and the end portion 70b is in contact with the brake shoe 3R. The end portion 70a is an example of a first end portion, and the end portion 70b is an example of a second end portion.

The strut set 70 is in a state where the two brake shoes 3 are close to each other, that is, in a state where the hydraulic pressure of the wheel cylinder 51 is lowered and close to each other by the action of the

return members

32, 80, etc. (non-braking state). It is sandwiched between the brake shoes 3. On the other hand, in the strut set 70, when the hydraulic pressure of the wheel cylinder 51 increases, the piston 52 pushes the two brake shoes 3, and the two brake shoes 3 are separated from each other (braking state), the two brake shoes 3, a gap (not shown) is formed between the

end portions

70 a and 70 b and the brake shoe 3.

The end portion 70a has a U-shaped bifurcated portion (not shown) opened toward the tip in the extending direction (direction X). The bifurcated portion sandwiches the bottom of the notch 3c of the brake shoe 3L in a direction (direction Y) perpendicular to the paper surface of FIG. Further, the side edge portions of the notch 3c of the brake shoe 3L facing each other sandwich the end portion 70a in a direction (direction Z) along the paper surface of FIG. Similarly, the bifurcated portion provided at the tip of the end portion 70b sandwiches the bottom portion of the notch 3c of the brake shoe 3R in the direction Y, and the side edge portions of the notch 3c of the brake shoe 3R facing each other end in the direction Z. Is sandwiched. With such a configuration, even when the gap between the

end portions

70a and 70b and the notch 3c of the brake shoe 3 is widened, the strut set 70 is prevented from falling off between the two brake shoes 3. ing

The strut set 70 has a mechanical automatic adjustment function that automatically lengthens the length between the

end portions

70a and 70b. Here, as described above, the strut set 70 is sandwiched between the two brake shoes 3 in a non-braking state. Therefore, the strut set 70 has a function of automatically adjusting the distance between the two brake shoes 3 in the non-braking state.

Although the strut set 70 will be described in detail later, the stroke between the

ends

70a and 70b increases as the stroke of the brake shoe 3R increases due to the action of the adjuster lever 4 interlocked with the brake shoe 3R (or the piston 52 that drives the brake shoe 3R). Is configured to be long. Here, the stroke of the brake shoe 3R increases as the lining 31 wears. Therefore, as the lining 31 wears and the stroke of the brake shoe 3R increases, the length between the

end portions

70a and 70b of the strut set 70 becomes longer. When the length between the

end portions

70a and 70b is increased, the interval between the two brake shoes 3 in the non-braking state is widened, and the positions (non-braking positions) of the two brake shoes 3 in the non-braking state are within the drum 2. Approach the peripheral surface 2a. From the above, the strut set 70 approaches the non-braking position of the two brake shoes 3 and the inner peripheral surface 2a of the drum 2 as the wear of the lining 31 increases. In other words, the strut set 70 can suppress an increase in the movement distance from the non-braking position of the brake shoe 3 to the braking position, that is, the shoe clearance due to increased wear of the lining 31. The adjuster lever 4 is an example of a pressing member.

In order to achieve such a function, the strut set 70 has a rotation / linear motion conversion mechanism including

non-rotating members

71a and 71b and a rotating member 72, for example. The rotating member 72 can also be referred to as an adjuster wheel. The rotating member 72 is supported by the

non-rotating members

71a and 71b so as to be rotatable about an axis Ax along the extending direction of the strut set 70, and is screw-coupled to one of the

non-rotating members

71a and 71b. As an example, the male screw provided in the rotating member 72 is inserted into the female screw hole provided in the non-rotating member 71a, and the non-rotating member 71b rotatably supports the rotating member 72. The rotating member 72 is configured to rotate only in a predetermined direction by the swinging of the adjuster lever 4 according to the reciprocating movement of the brake shoe 3R (or the piston 52 that drives the brake shoe 3R). Specifically, a ratchet gear 72a having a plurality of teeth arranged at a constant pitch is provided on the outer periphery of the rotating member 72, and the ratchet gear 72a is configured to mesh only in one direction of movement of the adjuster lever 4. Has been. The screw mechanism has a spiral such that the rotating member 72 protrudes from the non-rotating member 71a by the rotation of the ratchet gear 72a in a predetermined direction. In this case, the tip (not shown) of the adjuster lever 4 swings along the outer surface of the tooth as long as the wear amount of the lining 31 does not increase and the swing stroke is small. However, when the wear amount of the lining 31 increases and the swing stroke increases and the tip of the adjuster lever 4 gets over the teeth, the tip of the adjuster lever 4 pushes the teeth at the next swing timing, and the ratchet gear 72a. That is, the rotating member 72 rotates in a predetermined direction. As a result, the rotating member 72 protrudes from the non-rotating member 71a, and the length between the

end portions

70a and 70b of the strut set 70 is increased. As described above, the strut set 70 rotates the ratchet gear 72a by one tooth according to the increase in the wear amount of the lining 31, thereby increasing the length between the

end portions

70a and 70b, and the shoe clearance. Can be suppressed. The

non-rotating members

71a and 71b are examples of non-rotating parts, and the rotating member 72 is an example of a rotating part.

In such a configuration, if the desired engagement position and engagement posture between the adjuster lever 4 and the ratchet gear 72a cannot be obtained due to the strut set 70 tilting or moving, the position of the strut set 70 can be reduced. There is a risk that it will be difficult to obtain the automatic adjustment function of the period. Therefore, the brake device 1 according to the present embodiment includes a strut guide 90 in order to further stabilize the posture of the strut set 70.

[Structure of strut guide]
The strut guide 90 supports the strut set 70 so as to be movable in the extending direction of the strut set 70, that is, in the direction along the axis Ax of the strut set 70. The strut set 70 restricts movement in the direction intersecting the extending direction.

Specifically, as shown in FIGS. 2 and 3, a through portion 70 c having a cylindrical outer surface of the strut set 70 passes through a cylindrical through hole 90 a provided in the strut guide 90. In such a configuration, the maximum inclination angle of the strut set 70 can be set by the clearance between the through portion 70c and the through hole 90a. Therefore, according to the present embodiment, it is possible to suppress the automatic adjustment function from being impaired due to a change in the position or posture of the strut set 70.

Furthermore, the strut guide 90 is integrated with the wheel cylinder 51. Specifically, as shown in FIG. 3, the strut guide 90 is arranged in parallel with the wheel cylinder 51 and is provided at the tip of an arm 51 a extending from the wheel cylinder 51. 90 is one member. According to such a configuration, for example, the wheel cylinder 51 with the strut guide 90 can be manufactured at a time, for example, by casting or the like. Therefore, according to this embodiment, since the number of parts decreases compared with the case where the strut guide 90 and the wheel cylinder 51 are comprised separately, for example, the effort and cost of manufacturing the brake device 1 are easily reduced. . Further, since the strut guide 90 is made of the same metal material as the wheel cylinder 51, its rigidity and strength are easily set relatively high.

2, the return member 80 is a coil spring, and includes a coil portion 81, arms 82 at both ends thereof, and hooks 83 provided at the tips of the arms 82. The hook 83 is hooked on a notch 3 d provided on the outer peripheral side of the brake shoe 3. Here, the coil portion 81 is wound around the outer periphery of the strut guide 90. According to such a configuration, the inside of the coil portion 81 of the return member 80 can be used as a space where the strut guide 90 and the strut set 70 exist. Therefore, according to the present embodiment, for example, the strut guide 90 and the strut set 70 and the coil portion 81 are arranged at different positions, and the brake device 1 has a dead space inside the coil portion 81. Parts can be arranged more efficiently. Eventually, there may be a merit that the brake device 1 can be configured more compactly.

As described above, in this embodiment, the strut guide 90 supports the strut set 70 so as to be movable in the extending direction of the strut set 70 and restricts movement in a direction intersecting the extending direction of the strut set 70. is doing. According to such a structure, it can suppress that the automatic adjustment function by the strut set 70 is impaired by the change of the position and attitude | position of the strut set 70. FIG. Furthermore, since the strut set 70 is supported by the strut guide 90, the clearance between the brake shoe 3 and the

end portions

70a and 70b of the strut set 70 can be set wider, so that, for example, parts can be manufactured more easily, The effect of being easily assembled can also be obtained. Note that setting a wide clearance between the brake shoe 3 and the

end portions

70a and 70b of the strut set 70 is useful for preventing the movement of the brake shoe 3 in the Z direction.

In this embodiment, the strut guide 90 is configured integrally with the wheel cylinder 51. According to such a configuration, for example, labor and cost for manufacturing the brake device 1 are likely to be reduced.

In this embodiment, the coil portion 81 of the return member 80 is wound around the outer periphery of the strut guide 90. According to such a configuration, for example, the layout efficiency of parts in the brake device 1 may be increased.

(Second Embodiment)
The brake device 1A of the second embodiment shown in FIG. 4 has the same configuration as the brake device 1 of the first embodiment. Therefore, also in this embodiment, the same result based on the same configuration as the first embodiment is obtained.

However, in this embodiment, the strut guide 90A is a separate member from the wheel cylinder 51, and is coupled to the wheel cylinder 51 via a coupling mechanism. In the present embodiment, as an example, the strut guide 90A includes an arm 90b and an attachment piece 90c provided at the tip of the arm 90b, and the attachment piece 90c is attached to the wheel cylinder 51 by a fixture 100 such as a screw. And are fixed. According to such a configuration, since the restriction of the order between the step of penetrating the strut set 70 into the strut guide 90A and the step of inserting the strut guide 90A into the coil portion 81 of the return member 80 can be eliminated, the brake device In some cases, the labor and cost of manufacturing 1A can be reduced. Note that the connection between the strut guide 90A and the wheel cylinder 51 is not limited to a connection using a fixing tool such as a screw. For example, a connection using another fixing tool such as a rivet or a connection using a snap fit mechanism may be used. Good. Further, the strut guide 90A can be made of a material different from that of the wheel cylinder 51 and other components such as a synthetic resin material. Therefore, for example, the advantage that the strut guide 90A can be configured to be lighter and the slidability between the strut guide 90A and the strut set 70 can be further improved.

(Third embodiment)
The brake device 1B of the third embodiment shown in FIG. 5 has the same configuration as the brake device 1 of the first embodiment. Therefore, also in this embodiment, the same result based on the same configuration as the first embodiment is obtained.

However, in this embodiment, the strut guide 90A and the strut set 70 are not accommodated in the coil portion 81 of the return member 80, and the strut guide 90A and the strut set 70 and the return member 80 are arranged in parallel in the brake device 1B. Is provided. When there is a sufficient space for arranging parts in the brake device 1B, the brake device 1B may be manufactured more easily or more quickly by adopting such a layout.

As mentioned above, although embodiment of this invention was illustrated, the said embodiment is an example and is not intending limiting the range of invention. The above embodiment can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the spirit of the invention. In addition, the specifications (structure, type, direction, shape, size, length, width, thickness, height, number, arrangement, position, material, etc.) of each configuration, shape, etc. are appropriately changed. Can be implemented.

For example, the strut guide is not limited to a cylindrical shape as disclosed in the above embodiment, as long as it can suppress posture change and position change. For example, the structure which has an open cross section may be sufficient, and the structure which supports a strut set in multiple places may be sufficient. Further, the strut guide may be fixed to a part other than the wheel cylinder, such as a back plate or a part fixed to the back plate, or may be integrated with them, that is, a part other than the wheel cylinder. Moreover, the structure of a strut set is not limited to the said embodiment, It can implement | achieve as various structures.

Claims

Back plate,
A cylinder containing two pistons fixed to the back plate and protruding by the action of hydraulic pressure;
Two brake shoes movably supported on the back plate and pressed against a drum that rotates relative to the back plate by each of the projecting two pistons;
One of the two brake shoes extends between a first end that can abut against one of the two brake shoes and a second end that can abut against the other, and is interposed between the two brake shoes. And a non-rotating portion that is screw-coupled to the rotating portion, and a pressing member that interlocks with the piston or the brake shoe rotates the rotating portion relative to the non-rotating portion. A strut set configured to be longer in the extending direction as the amount of movement of the brake shoes increases, and to automatically adjust the distance between the two brake shoes;
A strut guide that supports the strut set movably in the extending direction and restricts movement of the strut set in a direction intersecting the extending direction;
Brake for vehicles equipped with.
The vehicle brake according to claim 1, wherein the strut guide is formed integrally with the cylinder.
The vehicle brake according to claim 2, wherein the strut guide is a member different from the cylinder attached to the cylinder.
A coil spring is provided between the two brake shoes along the extending direction and biases the two brake shoes in a direction approaching each other, and the coil portion of the coil spring is arranged around the outer periphery of the strut guide. The vehicle brake according to any one of claims 1 to 3, wherein the brake is disposed in a state of being wound around the vehicle.