JP2002061688A - Electrically-operated brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make more difficult to apply force such as flexing in the vicinity of the connection point to each connection member transmitting drive force of an actuator to a brake device main unit. SOLUTION: A crank arm 19 is fixed to an output shaft 25 of an actuator 20, this crank arm 19 is connected to a brake lever 16 by a connector 18. The connecter 18 is connected capable of relatively turning respectively by connection pins 26, 27 relating to the crank arm 19 and the brake lever 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric brake device using a motor as a drive source.

[0002]

2. Description of the Related Art Conventionally, as an electric brake device, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 11-99934. As shown in FIG. 9, in this electric brake, the rotary motor 51 of the actuator 50 is connected to the ball screw mechanism 5.
2 is driven to rotate, and the ball screw mechanism 52 has its output shaft 53
Is pulled. Then, the brake lever 55 connected to the brake cable 54 rotates, and the brake lever 55 cooperates with the strut 56 to form a pair of brake shoes 57a and 57b.
Is pressed against the friction surface 58a of the brake drum 58. That is, in this electric brake, the brake lever 55 that rotates is operated by the actuator 50 that moves the output shaft 53 straight.

[0003]

The brake cable 5 connected to the output shaft 53 of the ball screw mechanism 52
One end of 4 goes straight on the axis of the output shaft 53. On the other hand, the other end of the brake cable 54 connected to the brake lever 55 moves along an arc-shaped trajectory on which the end of the brake lever 55 moves. One end of the brake cable 54 is connected to a mounting nut 59 screwed to the output shaft 53, and the other end is also directly connected to an end of the brake lever 55. For this reason, when the actuator 50 pulls the brake cable 54, as shown in FIG. 10, the brake cable 54 bends near the connection point with the output shaft 53 or near the connection point with the brake lever 55. Become. Therefore, since the brake cable 54 bends near the connection points at both ends for each braking, part of the power of the motor 51 is wasted, and the brake cable 54 may be damaged due to long-term use. was there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to make each connecting member for transmitting a driving force of an actuator to a brake device main body to bend the vicinity of the connecting point. It is an object of the present invention to provide an electric brake device capable of suppressing unnecessary use of power of an actuator by making it harder to apply a force, and further improving reliability in use for a long period of time.

[0005]

According to a first aspect of the present invention, there is provided an actuator for rotating an operating member which presses a braking member against a friction surface of a member to be braked by an actuator. In the electric brake device that is caused to move, the actuator includes an output shaft that is controlled to rotate forward and backward, a rotating member is fixed to the output shaft, and a rotating outer peripheral portion of the rotating member; The rotation outer peripheral portion of the operation member is connected to a connection member by a connection member, and the connection member, the rotation member, and the operation member are connected so as not to apply a force to bend the vicinity of each connection point. That is the gist.

According to the first aspect of the present invention, when the operating member is rotated, the connecting point between the rotating member fixed to the output shaft and the connecting member, and the connecting point between the connecting member and the operating member. Therefore, no excessive force is applied to each member to bend the vicinity of the connection point. Therefore, the power of the actuator is not wasted, and unnecessary force is not applied to the rotating member, the connecting member, and the operating member.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a backing plate fixed to a vehicle, wherein the braked body has a friction surface, and is a brake drum which rotates with wheels. The brake body is a brake shoe pressed against a friction surface of the brake drum, and the operation member is rotatably supported by the backing plate or the brake shoe, and is rotated. The gist of the present invention is a brake lever that presses the brake shoe against a friction surface of the brake drum.

According to the invention described in claim 2, according to claim 1
In addition to the operation of the invention described in the above, at the time of operation of the actuator in the drum brake, at each connection point of the rotating member and the connection member, and at the connection point of the connection member and the brake lever, each member will bend near the connection point No excessive force is added.

According to a third aspect of the present invention, in the second aspect, the connecting member is a connector made of a rigid body, and the connector is relatively rotated with respect to the rotating member and the brake lever, respectively. The point is that they are connected as much as possible.

According to the invention described in claim 3, according to claim 2
In addition to the effects of the invention described in (1), a connector made of a rigid body is less likely to extend due to a tensile force even after repeated use, as compared with a cord-like traction member such as a wire cable. Therefore, the positional relationship between the rotating member and the brake lever is unlikely to change from the initial state, and the effectiveness of the brake is unlikely to decrease from the initial state. As a result, it is possible to eliminate the necessity of adjusting the effectiveness of the brake over a longer period.

According to a fourth aspect of the present invention, in the second aspect, the connecting member is a cord-like traction member, and the cord-like traction member is provided with respect to the turning member or the brake lever. Wound or unwound so as to be wound or unwound with the rotation of the turning member or the brake lever, or is supported so as to be rotatable relative to the turning member or the brake lever. The gist of the present invention is that it is connected to the connected connecting member.

According to the invention described in claim 4, according to claim 2,
In addition to the operation of the invention described in the above, at each connecting point between the rotating member and the cord-like connecting member and between the cord-like connecting member and the brake lever, it is impossible to bend each member near the connecting point. No force is applied.

According to a fifth aspect of the present invention, in the fourth aspect, the cord-like traction member is a wire cable, and the turning member is a pulley. According to the invention described in claim 5, in addition to the effect of the invention described in claim 4, a wire cable and a pulley, and
At each connection point between the wire cable and the brake lever, no excessive force is applied to each member to bend the vicinity of the connection point.

According to a sixth aspect of the present invention, in the first aspect of the invention, the actuator comprises a worm fixed to the motor main body and a rotating shaft of the motor main body. The output shaft comprises a worm gear fixed on a rotation shaft of a worm wheel.

According to the invention of claim 6, according to claim 1,
In addition to the effects of the invention described in any one of claims to 5, a high-speed, low-torque motor can be used. In addition, since the actuator does not operate depending on the input from the output side and does not reversely drive the actuator, the state where the brake is applied when the power is not supplied is maintained. As a result, a parking brake that does not consume power during braking can be provided.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the actuator is arranged such that a rotation axis of the motor body is on a plane perpendicular to a central axis of the backing plate with respect to the backing plate. The gist is that they are fixed so as to be arranged.

According to the invention described in claim 7, according to claim 6,
In addition to the operation of the invention described in (1), since the rotation axis, which is a factor determining the maximum length of the actuator, is arranged parallel to the backing plate, the size of the electric brake device including the actuator becomes smaller. .

[0018]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, the electric brake device 10 includes a backing plate 11, a brake drum 12 as a braked body, and a brake shoe 1 as a brake body.
3a, 13b, an adjuster 14, an anchor 15, a brake lever 16 as an operating member, a strut 17, a connector 18 as a connecting member, a crank arm 19 as a rotating member, and an actuator 20.

As shown in FIG. 3, the backing plate 1
1 is fixed to the axle tube AT, and the brake drum 12 is fixed to the axle AS together with the wheels W. As shown in FIG. 1, the brake shoes 13 a and 13 b are formed as a pair, and each upper end is connected to the adjuster 14, and each lower end is arranged on both sides of the anchor 15. Each shoe 1
The shoe return springs 3a and 13b are urged by a shoe return spring (not shown) such that the lower ends thereof respectively contact the anchors 15. And each brake shoe 13
When the lower ends of the a and 13b are operated to be separated from the anchor 15, the brake shoes 13a and 13b apply the brake lining 21 attached to the outer peripheral surface of the arc-shaped rim to the friction surface 12a of the brake drum 12. Press.

The brake lever 16 is connected to the brake shoe 13
The upper end of the brake shoe 13a is rotatably connected to the upper part of the web of the brake shoe 13a by a connecting pin 22.

The strut 17 is provided between the upper part of the brake lever 16 and the upper part of the left brake shoe 13b, and is engaged with the brake lever 16 and the brake shoe 13b, respectively. When the brake lever 16 is rotated clockwise so as to be separated from the brake shoe 13a, the brake lever 16 is moved to the brake shoe 13a connected by the connecting pin 22.
And the brake shoes 13b connected via the struts 17 are displaced away from each other, and pressed against the friction surfaces 12a of the brake drum 12, respectively.

As shown in FIG.
0 is fixed to the back surface 11a of the backing plate 11. The actuator 20 includes a motor main body 23, a speed reduction unit 24, and an output shaft 25, as shown in FIG. The speed reduction unit 24 includes a speed reduction mechanism including a worm 24 a fixed to the rotation shaft 23 a of the motor main body 23 and a worm wheel 24 b fixed to the output shaft 25.

As shown in FIG. 3, the output shaft 25 extends through the backing plate 11 to the front side of the plate 11. The actuator 20 is fixed to the backing plate 11 such that the rotation axis of the motor main body 23 is disposed on a plane orthogonal to the central axis G of the plate 11.

As shown in FIGS. 1 to 3, a crank arm 19 is fixed to the tip of the output shaft 25. The crank arm 19 is fixed to the output shaft 25 so that its tip is located below the output shaft 25. The distal end of the crank arm 19 and the lower end of the brake lever 16 are connected by a connector 18. The connector 18
One end thereof is connected to the crank arm 19 by the connecting pin 26.
The other end side is rotatably connected to the brake lever 16 by a connection pin 27. When the output shaft 25 is rotated forward or backward in a predetermined angle range by controlling the actuator 20,
The crank arm 19 rotates within a predetermined angle range, and the brake lever 16 rotates through the connector 18.

The operation of the electric brake device configured as described above will be described. This electric brake device 1
0 is controlled by a controller (not shown) provided in the vehicle. When the brake pedal and the parking brake lever are not operated, the controller controls the actuator 20 to bring the crank arm 19 into the state shown by the two-dot chain line in FIG.

When the crank arm 19 is arranged in the state shown by the two-dot chain line in FIG.
The brake shoe 13a connected by the connecting pin 22 is not pressed against the friction surface 12a of the brake drum 12, and the brake shoe 13b is connected via the strut 17 to the friction surface 1a.
Do not press against 2a. At this time, both brake shoes 13
a, 13b are retracted from the friction surface 12a of the brake drum 12 by the shoe return spring, and
Is held in contact with

On the other hand, when the brake pedal is depressed, the controller controls the actuator 20 in accordance with the depression amount to rotate the crank arm 19 clockwise, for example, to the state shown by the solid line in FIG.

When the crank arm 19 is arranged in the state shown by the solid line in FIG. 1, the brake lever 16 presses the brake shoes 13a, 13b against the friction surface 12a. As a result, braking is applied to the brake drum 12.

When the parking brake lever is operated, the controller controls the actuator 20 to rotate the output shaft 25 in the normal direction, thereby rotating the crank arm 19 clockwise, for example, to the state shown by the solid line in FIG. Then, the controller stops energizing the actuator 20 while the parking brake lever is operated. Then, the reverse rotation of the motor main body 23 due to the input from the output shaft 25 is regulated by the action of the worm gear constituting the speed reduction unit 24 of the actuator 20, and the braking state is maintained without energization. When the parking brake lever is released, the controller controls the actuator 20 to reverse the output shaft 25 and return the crank arm 19 to the state shown by the two-dot chain line in FIG. Then, the braking state of the brake is released.

When the operation of the actuator 20 causes the crank arm 19 to rotate clockwise or counterclockwise between the state shown by the two-dot chain line in FIG. 1 and the state shown by the solid line in FIG. It relatively rotates with respect to the crank arm 19 via a connecting pin 26, and relatively rotates with respect to the brake lever 16 via a connecting pin 27. Therefore, at each connection point between the crank arm 19 and the connector 18 and between the connector 18 and the brake lever 16, the crank arm 19, the connector 18 or the brake lever 16 are connected.
Does not apply excessive force to bend the vicinity of the connection point. For this reason, the power of the motor main body 23 is not wasted, and the crank arm 19, the connector 18 and the brake lever 16 are hardly damaged even when used for a long period of time, and the reliability is improved.

According to the embodiment described in detail above, the following effects can be obtained. (1) The crank arm 19 is fixed to the output shaft 25 of the actuator 20, and the crank arm 19 and the brake lever 16 are connected by the connector 18. Then, the connector 18 is connected to the crank arm 19 and the brake lever 1.
6 by connecting pins 26 and 27, respectively. Therefore, at each connection point, an unreasonable force for bending the vicinity of each connection point to the crank arm 19, the connector 18, and the brake lever 16 at each connection point is less likely to be applied. As a result, the power of the motor main body 23 is hardly wasted, and power consumption can be reduced. Further, even if the crank arm 19, the connector 18 and the brake lever 16
Is less likely to be damaged, so that the reliability can be further improved.

(2) Since the brake lever 16 and the crank arm 19 are connected by the connector 18 which is a rigid body, the brake lever 16 does not easily extend even when a repeated pulling force is applied, as compared with a case where a wire cable is used. Accordingly, the positional relationship between the brake lever 16 and the crank arm 19 is unlikely to change from the initial state, so that the effectiveness of the brake is unlikely to change from the initial state. For this reason, adjustment of the effectiveness of the brake can be made unnecessary over a longer period.

(3) Since the actuator 20 is composed of the motor main body 23 and the speed reducer 24, a DC motor with high rotation and low torque can be used. (4) Since the speed reducer 24 is formed of a worm gear that does not reversely operate due to an input from the output shaft 25, the braking state can be maintained without energizing the motor body 23. Therefore, during operation as a parking brake, the braking state can be maintained without consuming power.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, the only difference is that the crank arm 19 as the rotating member in the first embodiment is changed to the pulley 30 and the connector 18 as the connecting member is changed to the wire cable 31. This is different from the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Only the pulley 30 and the wire cable 31 will be described in detail.

As shown in FIGS. 6 to 8, a pulley 30 as a rotating member is fixed to the tip of the output shaft 25. The pulley 30 is formed in a fan shape with a predetermined angle,
5 below. One end of a wire cable 31 as a cord-like traction member is connected to the pulley 30. In addition, the wire cable 31 is wound so as to be wound or unwound in the guide groove 30a as the pulley 30 rotates.

On the other hand, the other end of the wire cable 31 is connected to a connecting pin 32 as a connecting member rotatably supported on the lower end of the brake lever 16, as shown in FIG.

When the output shaft 25 is rotated forward or backward in a predetermined angle range by controlling the actuator 20,
The pulley 30 rotates within a predetermined angle range, and the wire cable 3
The brake lever 16 is rotated via the first lever 1.

When the pulley 30 rotates clockwise or counterclockwise between the state shown by the two-dot chain line in FIG. 6 and the state shown by the solid line in FIG. 7, the wire cable 31 At the connection point, it relatively rotates via the connection pin 32, and at the connection point with the pulley 30, the guide groove 3 of the pulley 30
0a is guided to extend tangentially. Therefore, the wire cable 31 and the brake lever 16, and
At the connection point between the wire cable 31 and the pulley 30, no excessive force is applied to the wire cable 31 or the brake lever 16 to bend the vicinity of the connection point. For this reason, the power of the motor main body 23 is not wasted, and the wire cable 31 and the brake lever 16 are hardly damaged even when used for a long period of time, so that the reliability is improved.

According to the present embodiment described in detail above, each of the effects (1), (3) and (4) of the first embodiment can be obtained. Hereinafter, embodiments other than the above embodiment will be listed.

The drive source of the actuator is, for example, D
It is not limited to a high rotation and low torque type motor such as a C motor, but may be a low rotation and high torque type motor such as an ultrasonic motor and a wobble motor. In this case, since the rotating member can be directly fixed to the output shaft of the motor, a speed reduction mechanism is not required, and the size of the entire brake device having the actuator can be further reduced.

The speed reduction mechanism of the actuator is not limited to the worm gear, but may be a gear device including a planetary gear. In this case, since the motor body 23 rotates in the reverse direction by the torque input from the output shaft 25, the braking state is not maintained in the non-energized state. To solve this, an electromagnetic brake for braking when not energized is connected to the actuator and the output shaft 25.
May be provided during the operation of the actuator to control the actuator to be in the non-braking state. Also in this configuration, the braking state can be maintained without consuming power when operating as a parking brake.

The cord-like traction member is not limited to a wire cable, and may be, for example, a chain.・ The basic structure of the drum brake body is
Not limited to trailing, it may be a reading or a duo servo.

Hereinafter, the technical ideas grasped from each of the above embodiments will be described together with their effects. (1) In the invention according to any one of claims 1 to 5, the actuator reversely operates the motor main body and the motor main body according to an input from an output side while reducing the output of the motor main body. An electric brake device comprising a decelerating means (a worm 24a and a worm wheel 24b) that does not perform the operation. According to such a configuration, a motor having high rotation and low torque can be used, and a braking state can be maintained without consuming electric power during operation as a parking brake.

(2) In the invention according to any one of claims 1 to 5, the actuator comprises a motor main body and holding means (electromagnetic brake) for preventing the motor main body from being reversely operated by an input from an output side. ). According to such a configuration, during operation as a parking brake, the braking state can be maintained without consuming power.

(3) The electric brake device according to any one of claims 1 to 5, wherein the actuator comprises an ultrasonic motor or a wobble motor. According to such a configuration, the speed reduction mechanism is not required, and the entire brake device having the actuator can be further reduced in size.

[0047]

According to the first to seventh aspects of the present invention, a force for bending the vicinity of the connection point of each connection member for transmitting the driving force of the actuator to the brake device main body is less likely to be applied. Thus, it is possible to suppress unnecessary consumption of the power of the actuator, and to further improve the reliability in use for a long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an electric brake device according to a first embodiment.

FIG. 2 is a schematic front view showing an operation state.

FIG. 3 is a schematic sectional view taken along line AA in FIG. 1;

FIG. 4 is a schematic front view of an actuator.

FIG. 5 is a schematic view of a connecting member.

FIG. 6 is a front view of an electric brake device according to a second embodiment.

FIG. 7 is a schematic front view showing an operation state.

FIG. 8 is a schematic sectional view taken along the line BB in FIG. 6;

FIG. 9 is a schematic front view showing a conventional electric brake device.

FIG. 10 is a schematic diagram showing a connection state of a wire cable during operation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Electric brake device, 11 ... Backing plate, 12 ... Brake drum as braked body, 12a ...
Friction surfaces, 13a, 13b: brake shoes as braking bodies, 16: brake levers as operating members, 18: connectors as connecting members, 19: crank arms as rotating members, 20: actuators, 23: motor body, Reference numeral 24: speed reduction unit, 24a: worm, 24b: worm wheel, 25: output shaft, 30: pulley as a rotating member, 31: wire cable as a connecting member and a cord-like traction member, 32: connecting pin as a connecting member , G: central axis.

Claims (7)

[Claims] An operating member (16) that presses a braking body (13a, 13b) against a friction surface (12a) of a body to be braked (12) by a rotating operation is rotated by an actuator (20). In the electric brake device, the actuator (20) includes an output shaft (25) that is controlled to rotate forward and backward, and a rotating member (19, 30) is fixed to the output shaft (25). The rotating outer peripheral portions of the rotating members (19, 30) and the rotating outer peripheral portion of the operating member (16) are connected by connecting members (18, 31), and the connecting members (18.3) are connected.
1) An electric brake device wherein the rotating member (19.30) and the operating member (16) are connected so as not to apply a force to bend the vicinity of each connecting point. 2. A brake drum (12) having a backing plate (11) fixed to a vehicle, the braked body having a friction surface (12a), and rotating with wheels. Brake shoes (13a, 13a, 13b) pressed against the friction surface (12a) of the brake drum (12)
13b), wherein the operating member (16) is provided on the backing plate (1).
1) or the brake shoe (13a, 13b)
And a brake lever (16) which is rotatably supported with respect to the brake drum (12a) and presses the brake shoes (13a, 13b) against a friction surface (12a) of the brake drum (12) by being rotated. The electric brake device according to claim 1, wherein 3. The connector according to claim 2, wherein the connecting member is a connector made of a rigid body, and the connector is rotatably connected to the rotating member and the brake lever. 3. The electric brake device according to claim 1. 4. The connecting member is a bendable traction member (31) that can be flexibly deformed, and the traction member is rotatable with respect to the turning member (30) or the brake lever (16). The member (30) or the brake lever (16) is wound or unwound so as to be wound or unwound with the rotation thereof,
Alternatively, the rotating member (30) or the brake lever (1
The coupling member (3) supported so as to be relatively rotatable with respect to (6).
The electric brake device according to claim 2, wherein the electric brake device is connected to (2). 5. The wire-like traction member comprises a wire cable (3).
The electric brake device according to claim 4, wherein in 1), the rotating member is a pulley (30). 6. The actuator (20), wherein a worm (24a) is fixed to the motor main body (23) and a rotation shaft (23a) of the motor main body (23), and the output shaft (25) is a worm. The electric brake device according to any one of claims 1 to 5, comprising a worm gear fixed on a rotation shaft of the wheel (24b). 7. The actuator (20) is arranged such that a rotation axis (23a) of the motor body (23) is perpendicular to a center axis (G) of the plate (11) with respect to the backing plate (11). The electric brake device according to claim 6, wherein the electric brake device is fixed so as to be disposed thereon.