JP4168301B2 - Electric brake device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brake device used for applying a braking force to a vehicle or the like, for example, and more particularly to an electric brake device that generates a braking force by an electric motor.
[0002]
[Prior art]
In general, a mounting member provided on a non-rotating portion of a vehicle, a caliper mounted to the mounting member so as to be displaceable in the axial direction of the disk, and pressed by the caliper on both sides of the disk, 2. Description of the Related Art A brake device serving as a disc brake including a pair of friction pads for imparting a friction is known.
[0003]
In these brake devices, an electric motor is provided in the caliper, and the rotational output (torque) of the electric motor is converted into the axial displacement of the piston, thereby pressing the pair of friction pads on both sides of the disk. There is known an electric brake device configured as described above (for example, WO96 / 03301).
[0004]
In this type of prior art electric brake device, a motor stator of an electric motor is fixed in a caliper as an electric actuator that is a means for generating axial pressing force on a piston, and is radially inward of the motor stator. Is provided with a motor rotor and a ball screw mechanism for converting the rotation of the motor rotor into the axial displacement of the piston on the inner peripheral side of the motor rotor.
[0005]
When the driver of the vehicle depresses the brake pedal, the electric brake device of the prior art rotates the electric motor with a rotation angle or rotation torque corresponding to the operation amount at this time, and the ball screw mechanism The rotation of the electric motor is converted into the axial displacement of the piston, and a pair of friction pads are pressed against both sides of the disk by the axial pressing force of the piston, thereby applying a braking force to the vehicle via the disk. . In this case, when one friction pad on the action part side (for example, the inner side) of the pair of friction pads is pressed against one side surface of the disk by the piston, the pressing reaction force at this time acts on the caliper, so that the caliper is attached. The member is slid and displaced in the direction opposite to the pressing direction of the piston with respect to the member. Thereby, the reaction part provided in the caliper presses the other friction pad against the other side surface of the disc, and the disc is sandwiched between the one friction pad and the other friction pad, and a braking force is applied.
[0006]
[Problems to be solved by the invention]
By the way, the electric brake device according to the related art described above, when applying a braking force to the rotating disk, slides and moves the caliper in the direction opposite to the pressing direction of the piston. The disc is sandwiched between the friction pad and the outer friction pad to generate a braking force.
[0007]
However, when releasing the braking force, even if the electric motor is rotated in the reverse direction and the piston is retracted from the disk, the caliper has an electric motor inside, so that the caliper is relatively heavy. Therefore, even if the clearance between the inner friction pad and the disk can be secured, the clearance should be secured between the outer friction pad and the disk. There is a problem that it is difficult to do.
[0008]
For this reason, in the prior art, even when the braking force is released, the outer friction pad may continue to contact the disk, and a so-called pad drag phenomenon may occur, and the outer friction pad may be worn out early. In addition, for example, there is a problem that the driving force of the vehicle is wasted due to dragging of the friction pad, and the fuel efficiency is lowered.
[0009]
The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to ensure a good pad clearance when the braking force is released, to prevent the pad drag phenomenon, An object of the present invention is to provide an electric brake device capable of reducing wear and improving the service life and contributing to improvement of fuel consumption of a vehicle.
[0010]
Another object of the present invention is to automatically adjust the clearance between the disc and the friction pad even when the friction pad gradually wears out as the brake operation is repeated, improving the responsiveness during the brake operation. An object of the present invention is to provide an electric brake device that can be used.
[0011]
[Means for Solving the Problems]
To solve the problems described above, the present invention includes a mounting member fixed to a non-rotating portion of the vehicle, Ru is slidably supported by a pair of slide pins in the axial direction of the disk relative to the mounting member and · the Yaripa, disposed across the disk, a pair of friction pads provided retractably with respect to the disk in the axial direction of the disc, provided in the carry path, the pair of friction pads against the disc in the electric brake device of Bei obtaining configuration and an electric actuator for advancing and retracting, provided on one of said mounting member or said caliper, extends between the mounting member and the caliper in the sliding direction of the caliper, the and one guide member that is provided in an intermediate portion between the pair of slide pins, a positioning member mounted with a sliding resistance on the guide direction on the guide member, The end side is the positioning member, the other end engaged with each other one of the mounting member or the caliper, is deformed in accordance with the amount of movement relative to the mounting member of the caliper during braking, reacting portion side of the caliper during braking release consists of a resilient member which defines a clearance with respect to the disk of the friction pad, the sliding resistance of the positioning member is made larger than the restoring force when the elastic member is deformed by the amount range of the clearance, the positioning member is characterized by sliding to Rukoto to the guide member after the elastic member has the maximum amount of deformation.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a longitudinal sectional view of an electric brake device according to an embodiment of the present invention, and FIG. 2 is a view of the electric brake device as viewed from above.
[0014]
In the figure, reference numeral 10 denotes a carrier as a mounting member attached to a non-rotating portion of the vehicle. The carrier 10 is fixed to a non-rotating portion (not shown) of the vehicle via a bolt or the like, as shown in FIG. Are provided with a pair of arms 10A and 10B extending in the axial direction of the disk 7 (from the inner side to the outer side).
[0015]
And each arm part 10A, 10B of the carrier 10 straddles the outer peripheral side of the disk 7 rotating integrally with the vehicle wheel (not shown), and an inner side friction pad 6 described later on both sides in the axial direction of the disk 7 The outer friction pad 8 is slidably supported. The carrier 10 is provided with an arch-shaped reinforcing portion 10C that integrally connects the arm portions 10A and 10B on the outer side of the disk 7, and the reinforcing portion 10C increases the rigidity of the carrier 10 as a whole.
[0016]
Reference numeral 11 denotes a fixed end fixed to the carrier via a pair of sliding pins 12A and 12B. The fixed end 11 is formed of a rigid material as a U-shaped frame plate as shown in FIG. The side is fixed to the ends of the sliding pins 12A and 12B by means such as screwing. The fixed end 11 extends in the left-right direction on the back side (right side in FIG. 2) of the housing 2 to be described later, and a return rod 11A as a guide member is integrally provided at an intermediate portion thereof.
[0017]
That is, the return rod 11A constitutes a part of the carrier 10, and the distal end side of the return rod 11A is slidably inserted into the housing 2 through the insertion hole 30 described later.
[0018]
An electric caliper 1 is attached to the carrier 10 so as to be displaceable in the axial direction of the disk 7. The electric caliper 1 is a housing 2 positioned on one end side (inner side) of the disk 7, as shown in FIG. And a claw part 9 as a reaction part located on the other end side (outer side) of the disk 7 and a bridge part 33 integrally connecting the housing 2 to the claw part 9 across the outer peripheral side of the disk 7 A lid 34 is provided on one end side of the housing 2.
[0019]
Further, the housing 2 is provided with connecting portions 2A and 2B spaced apart in the circumferential direction of the disk 7, and the connecting portions 2A and 2B are inserted into the outer peripheral sides of the sliding pins 12A and 12B as shown in FIG. ing. The electric caliper 1 is supported by the connecting portions 2A and 2B (sliding pins 12A and 12B) so as to be slidable in the axial direction of the disk 7 (left and right direction in FIG. 2) with respect to the carrier 10. .
[0020]
Further, the lid body 34 of the housing 2 is provided with a stepped hole having a large diameter portion and a small diameter portion coaxially from the outside of the lid body 34 (the right side in FIG. 1). The small-diameter portion is an insertion hole 30 that penetrates the lid body 34 without penetrating the lid body 34. For this reason, a flange 34B is formed in a portion where the large diameter portion does not penetrate and the small diameter portion penetrates. A return mechanism cover 35 is provided outside the stepped hole (on the right side in FIG. 1). The return mechanism cover 35 is coaxial with the insertion hole 30 and has the same diameter as the insertion hole 30. A hole 35A is drilled.
[0021]
The return rod 11A is slidably inserted into the return mechanism lid hole 35A and the insertion hole 30. In the large diameter portion of the stepped hole, the disc spring 31A as an elastic body comes into contact with the flange 34B, and the coil spring 31B comes into contact with the disc spring 31A as a positioning member and returns its axis to the rod 11A. Is inserted. Here, the inner diameter of the coil spring 31B in a state where no external force is applied is set slightly smaller than the diameter of the return rod 11A, so that the coil spring 31B has a considerable amount of sliding resistance on the return rod 11A. The sliding resistance value is set to be considerably larger than the force value necessary for contracting the disc spring 31A. The return mechanism 31 is formed by the return mechanism cover 35, the return mechanism cover hole 35A, the return rod 11A, the disc spring 31A, the coil spring 31B, and the flange 34B.
[0022]
An electric motor as an electric actuator is configured by the motor rotor 3 and the motor stator 4 inside the housing 2. The motor rotor 3 is electrically connected to an external power supply device (not shown) and supplied with power. Rotates around its axis. At this time, the rotation direction of the motor rotor 3 can be rotated forward and reverse by switching the current during power feeding.
[0023]
A piston 21A is slidably fitted in the motor rotor 3, and a ball screw mechanism 21 is provided on a sliding portion between the inner peripheral surface of the motor rotor 3 and the outer peripheral surface of the piston 21A. Thereby, when the motor rotor 3 rotates, the piston 21 </ b> A moves in the axial direction (advance / retreat operation) by the ball screw mechanism 21.
[0024]
Reference numeral 32 denotes a detent plate provided on one end (rear end) side of the piston 21A. The detent plate 32 is fixed to the piston 21A at a position close to the lid 34, and its outer peripheral side is a latch of the lid 34. The groove 34A is slidably locked. Then, the rotation of the piston 21A within the motor rotor 3 is restricted by the anti-rotation plate 34, and the piston 21A moves forward and backward in the axial direction (left and right direction in FIG. 1) without rotating.
[0025]
A pressing head 5 as an action part is fixed to the other end side of the piston 21A using a bolt or the like, and the pressing head 5 moves forward and backward in the axial direction together with the piston 21A. When the piston 21 </ b> A moves in the left direction in FIG. 1, the pressing head 5 is configured to press an inner friction pad 6, which will be described later, to the disk 7.
[0026]
Reference numerals 6 and 8 denote a pair of friction pads disposed on both sides of the disk 7. The friction pads 6 and 8 can move in the axial direction of the disk 7 to the arms 10A and 10B of the carrier 10 shown in FIG. It is supported by.
[0027]
Next, the operation of the electric brake device of the present embodiment configured as described above will be described below.
[0028]
When power is supplied to the electric motor for braking from an external power supply device (not shown) by brake operation, the motor rotor 3 rotates forward, and the piston 21A moves to the left in FIG. 3 as shown in FIG. The pressing head 5 presses the inner friction pad 6 toward one side of the disk 7.
[0029]
Further, as shown in FIG. 4, the entire electric caliper 1 is slid rightward in FIG. 4 with respect to the carrier 10 by the reaction force of the pressing pad 5 pressing the inner friction pad 6 toward one side of the disk 7. Dynamic displacement. As a result, the outer friction pad 8 is pressed toward the other side of the disk 7 together with the claw portion 9 of the electric caliper 1.
[0030]
Further, when the piston 21A moves to the left in FIG. 3, the pressing head 5 further presses the inner friction pad 6 toward one side of the disk 7, and the reaction force causes the entire electric caliper 1 to move against the carrier 10. Further, the outer side friction pad 8 is further pressed toward the other side of the disk 7 together with the claw portion 9 of the electric caliper 1 due to sliding displacement in the right direction in FIG.
[0031]
The friction pads 6 and 8 thus hold the disc 7 strongly from both sides, thereby giving a braking force to the rotating disc 7.
[0032]
When the entire electric caliper 1 is slid and displaced in the right direction in FIG. 4 with respect to the carrier 10, the flange 34 </ b> B integrated with the electric caliper 1 is illustrated with respect to the fixed end 11 integrated with the carrier 10. 4, but the sliding resistance between the coil spring 31 </ b> B and the return rod 11 </ b> A is greater than the force required for the disc spring 31 </ b> A to contract in the return mechanism 31, so the coil spring 31 </ b> B is moved to the right in FIG. 4. Does not move, and the disc spring 31A is contracted.
[0033]
On the other hand, when the brake operation is released, an electric power is supplied to the electric motor from an external power supply device (not shown) in order to release the braking, by switching the current from the aforementioned braking. Then, the motor rotor 3 rotates in the opposite direction to that in the above-described braking, and as shown in FIG. 5, the piston 21A moves in the right direction in FIG. The pressure toward the one side of the disk 7 is released, and the inner friction pad 6 is separated from the disk 7.
[0034]
As the inner friction pad 6 moves away from the disk 7, the reaction force that moves the electric caliper 1 to the right in FIG. 6 with respect to the carrier 10 is eliminated as shown in FIG. Due to the force that the disc spring 31A, which has been shrunk during braking, tries to return to its original position, the entire electric caliper 1 moves to the left in FIG. 6 with respect to the fixed end 11 integrated with the carrier 10, and thus the electric caliper The outer friction pad 8 pressed against the disk 7 by the one claw portion 9 is separated from the disk 7.
[0035]
At this time, the pressing head 5 and the inner friction pad 6, and the claw portion 9 and the outer friction pad 8 are not fixed to each other, but when the pressure on the disk 7 is released, the friction pads 6 and 8 are released. Is supported by the carrier 10 so as to be movable in the axial direction of the disk 7, so that it is separated from the disk 7 due to a shake during rotation of the disk 7.
[0036]
Thus, according to the embodiment of the present invention, the outer friction pad 8 can be reliably separated from the disk 7 by the force with which the disc spring 31A contracted during braking attempts to return to the original state.
[0037]
As a result, dragging of the outer friction pad 8 during non-braking can be eliminated, so that wear of the friction pad can be reduced, life and reliability can be improved, and fuel efficiency of the vehicle can be improved.
[0038]
When the friction pads 6 and 8 are worn and the distance between the disc 7 and the disc 7 increases by a certain amount or more, the sliding displacement of the piston 21A during braking increases, and accordingly, the electric caliper 1 with respect to the carrier 10 is increased. Although the amount of displacement also increases, in the electric brake device of the present invention, if the amount of displacement of the electric caliper 1 relative to the carrier 10 exceeds the amount that can be compressed and deformed by the disc spring 31A during the brake operation, the disc spring 31A After the compression deformation, the flange 34B returns the coil spring 31B inserted into the return rod 11A with sliding resistance and the sliding spring 31A having the maximum amount of deformation by the amount of displacement exceeding the return rod 11A. Slide against.
[0039]
When the brake operation is released, the coil spring 31B remains at the position after sliding, so that the disc spring 31A moves the electric caliper 1 in the left direction in FIG. 1 at a position where it contacts the coil spring 31B at the position after sliding. The outer friction pad 8 is separated from the disk 7 by pushing and restoring from the compression deformation state.
[0040]
At this time, the amount that the electric caliper 1 is returned by the disc spring 31A is substantially equal to the maximum compression deformation amount of the disc spring 31A, and the distance between the outer friction pad 8 and the disk 7 is the maximum compression deformation amount of the disc spring 31A. Is adjusted to be approximately equal to the length.
[0041]
Further, in the electric brake device of the present invention, the position of the piston 21A in the electric caliper 1 when the inner friction pad 6 is pressed against the disk 7 at the time of the brake operation can be estimated from the change in current during power supply. When the brake operation is released, power is supplied so as to return the piston 21A by a certain amount with reference to the position, and the amount by which the electric caliper 1 is returned by the disc spring 31A, that is, the inner friction pad 6 is disc by the disc spring 31A. 7 is also constant, the distance between the inner friction pad 6 and the disk 7 is adjusted to be constant.
[0042]
Thus, since the distance between the friction pads 6 and 8 and the disk 7 is always adjusted to be constant, even when the friction pads 6 and 8 are worn, the distance between the friction pad and the disk increases and the brake operation starts. It is possible to prevent the time until the friction pad is actually pressed against the disk from being changed, and to improve the responsiveness during brake operation.
[0044]
In this embodiment, the coil spring is used as the positioning member. However, the present invention is not limited to this, and as shown in FIG. 7 (partially enlarged view of the return mechanism), a wave shape is formed in the cylindrical case 31E. The spring 31D may be housed, or the other may cause a considerable amount of sliding resistance with the return rod 11A.
[0045]
Further, in order to adjust the maximum compression deformation amount of the disc spring 31A and to prevent the disc spring 31A from being deformed excessively and changing its elasticity, for example, as shown in FIG. A ring 31F may be provided between the flange 34B.
[0046]
Further, the elastic member is not limited to the disc spring 31A, and any elastic member may be used as long as it is deformed according to the amount of movement of the electric caliper 1 relative to the carrier 10 during braking and returns the electric caliper 1 to the outer side by a restoring force when braking is released. Other elastic bodies such as rubber and coil springs may be used.
[0047]
In the present embodiment, the elastic member is compressed by the movement of the caliper relative to the carrier as the mounting member, and the caliper is moved by the restoring force to separate the outer friction pad from the disk. For example, the elastic member may be extended by the movement of the caliper with respect to the carrier using a tension spring, and the caliper may be moved by the restoring force so that the outer friction pad is separated from the disk.
[0048]
Further, in the present embodiment, a guide member is provided on the carrier that is an attachment member, a positioning member is provided on the guide member, and one end of the elastic member is engaged with the positioning member and the other end is engaged with the caliper. However, the present invention is not limited to this. A guide member is provided on the caliper, a positioning member is provided on the guide member, one end of the elastic member is the positioning member, and the other end is the mounting member. It is good also as a structure which each engages.
[0049]
【The invention's effect】
As described above, the present invention is provided on one of the mounting member or the caliper, extends between the mounting member and the caliper in the sliding direction of the caliper, between the pair of slide pins and one guide member that is provided in an intermediate portion, and a positioning member mounted with a sliding resistance on the guide direction on the guide member, to the positioning member one end, the other end to the other of the attachment member or the caliper The positioning member comprises an elastic member that engages and is deformed according to the amount of movement of the caliper relative to the mounting member during braking, and that defines a clearance with respect to the disk of the friction pad on the reaction part side of the caliper during braking release. sliding resistance is made larger than the restoring force when the elastic member is deformed by the amount range of said clearance, said positioning member By sliding to Rukoto to the guide member after the serial elastic member has a maximum amount of deformation, the pad clearance when releasing the braking force can be favorably ensured, it is possible to prevent dragging phenomenon of the pad, the wear of the friction pad the by reducing can improve the lifetime and Ru der it can contribute to improved fuel efficiency of the vehicle. In addition, the sliding resistance of the positioning member is configured to be larger than the restoring force when the elastic member is deformed by the clearance, and the positioning member is the guide member after the elastic member is deformed by the maximum amount. against the slide to Rukoto, even when gradually worn friction pads after repeated braking operation, by the positioning member is moved in accordance with the wear of the friction pad against the sliding resistance between the guide member In addition, the clearance between the disc and the friction pad can be automatically adjusted to improve the responsiveness during brake operation.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of one embodiment of an electric brake device according to the present invention.
FIG. 2 is a top view of one embodiment of the electric brake device of the present invention.
FIG. 3 is a longitudinal sectional view showing the operation of the electric brake device of the present invention.
[Fig. 4] Same as above [Fig. 5] Same as above [Fig. 6] Same as above [Fig. 7] This is a modification of the embodiment of the electric brake device of the present invention.

Claims (1)

A mounting member fixed to a non-rotating portion of the vehicle, and Ruki Yaripa is slidably supported by a pair of slide pins in the axial direction of the disk relative to the mounting member, arranged across the disc, the disc a pair of friction pads provided retractably with respect to the disk in the axial direction of the provided carry path, configured electric brake of obtaining Bei and an electric actuator for advancing and retracting the pair of friction pads against the disc In the device
Said mounting member or provided on one of the caliper, extends between the mounting member and the caliper in the sliding direction of the caliper, the pair of one that is provided in an intermediate portion between the sliding pin guide Members,
A positioning member mounted on the guide member with sliding resistance in the guide direction;
One end side is engaged with the positioning member, the other end side is engaged with either the mounting member or the caliper, and is deformed according to the amount of movement of the caliper relative to the mounting member at the time of braking , and the reaction part side of the caliper at the time of braking release Consisting of an elastic member that regulates the clearance of the friction pad to the disk,
The sliding resistance of the positioning member is configured to be greater than the restoring force when the elastic member is deformed by the clearance, and the positioning member is deformed with respect to the guide member after the elastic member is deformed by the maximum amount. electric brake apparatus according to claim sliding to Rukoto Te.

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