JPH11132266A - Electric disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the connection of a driving member and a pressing member without increasing the number of parts of a disc brake and also without generating hitting sound between the driving member and the pressing member in the vibration of the disc brake, in an electric disc brake in which the driving member and the pressing member are provided to transmit driving force of a motor to a friction pad. SOLUTION: A driving member 100 and a pressing member 70 are brought in to contact with each other so that the driving member 100 may be inclined in relation to the pressing member 70, and the driving member 100 and the pressing member 70 are elastically connected to each other by an elastic member 124 so that the contact state of the driving member 100 and the pressing member 70 may be maintained in the vibration of a disc brake 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric disk brake using a motor as a drive source, and more particularly to a drive member provided in the electric disk brake for transmitting the driving force of the motor to a friction material. And a pressing member.

[0002]

2. Description of the Related Art Generally, the above-mentioned electric disc brake is
(a) a disk that rotates with wheels, (b) a friction material pressed against the disk to suppress the rotation of the disk, (c) a motor, and (d) a driving force of the motor transmitted to the friction material. A driving member that is inseparably connected to a motor and is driven by the motor;
A pressing member that receives an operating force from the driving member between the driving member and the friction material and presses the friction material against the disc;
A driving force transmission device having a coupling mechanism for coupling the driving member and the pressing member so that the driving force of the motor is transmitted to the pressing member via the driving member is provided.

[0003] One conventional example is WO96 / WO.
03301. In this conventional example,
An intermediate member is provided between the driving member and the pressing member so as to be in contact with them, so that the driving force of the motor is transmitted to the friction material through the driving member, the intermediate member, and the pressing member in that order. Has become. Further, the driving member is in contact with one end of the intermediate member, and the other end of the intermediate member is in contact with the pressing member. In this state, the driving member is allowed to be inclined with respect to the pressing member. ing. Further, the driving member and the pressing member are connected by a metal bellows straddling the intermediate member in a state where the inclination of the driving member with respect to the pressing member is allowed but the relative rotation is prevented.

[0004]

However, in this conventional example, since the driving member and the pressing member are connected via an intermediate member,
There is a problem that the number of parts of the disc brake increases and the size of the disc brake tends to increase.

[0005] In a general disc brake, it is desirable that no striking sound is generated when the disc brake vibrates.
However, in this conventional example, the bellows does not elastically connect the driving member and the pressing member so that the contact state between the driving member, the intermediate member, and the pressing member is maintained during the vibration of the disc brake. Absent. Therefore, in this conventional example, it is expected that a large gap is generated between the driving member and the intermediate member and between the pressing member and the intermediate member when the disk brake vibrates. It is expected that a tapping sound is generated between the member and the intermediate member and the pressing member. Therefore, this conventional example also has a problem that the driving force transmission device is likely to generate a tapping sound when the disk brake vibrates.

The present invention has been made in view of the above circumstances, and an object of the present invention is to connect a driving member and a pressing member provided for transmitting a driving force of a motor to a friction material in an electric disk brake to each other. An object of the present invention is to solve the above-mentioned problem by improving a mechanism for performing the above.

[0007] This problem is solved by the following electric disk brake. In the following description,
Each aspect of the present invention will be described in the same form as the claims, with the respective items numbered. This is to clarify the possibility of adopting the features described in each section in combination.

(1) A disk that rotates with wheels, a friction material pressed against the disk to suppress the rotation of the disk, a motor, and a driving force transmission device that transmits the driving force of the motor to the friction material (A) a driving member which is inseparably connected to the motor and driven by the motor, and (b) receives the operating force from the driving member between the driving member and the friction material to thereby form the friction material A pressing member that presses against the disc; and (c) a connection mechanism that connects the driving member and the pressing member so that the driving force of the motor is transmitted to the pressing member via the driving member. The driving member and the pressing member are elastically connected to each other by the elastic member so that the driving member can tiltably contact the pressing member and the contact state is maintained when the electric disc brake vibrates. And a driving force transmitting device having a coupling mechanism that engages with the electric disk brake. In this disc brake,
The driving member and the pressing member are connected without the intermediate member. Therefore, according to this disc brake, the drive member and the pressing member can be connected without increasing the number of parts or enlarging the size. In this disc brake, the driving member and the pressing member are formed by the elastic member.
They are elastically connected so that their contact state is maintained during the vibration of the disc brake. Therefore, according to this disc brake, it is possible to suppress the occurrence of a large gap between the driving member and the pressing member at the time of its vibration, and it is also possible to suppress strong collision between the two members. It is also possible to suppress the occurrence of a tapping sound from these two members. According to this disc brake, since the driving member and the pressing member are connected so that the driving member can be inclined with respect to the pressing member, when the driving member is inclined with respect to the pressing member, the driving member and the pressing member are bent by the pressing member. Neither the moment nor the bending moment acts on the drive member, which makes it easy to optimize the surface pressure distribution on the contact surface of the friction material with the disk, and in the motor, the rotor is inclined with respect to the stator. Can be easily prevented. Further, according to the disc brake, the inclination of the driving member with respect to the pressing member can be realized without using an intermediate member, unlike the conventional example. In addition,
In this disc brake, the "pressing member" may be one that can be separated from the friction material or one that cannot be separated. It is not essential that the pressing member is separate from the friction material, and the pressing member may be formed integrally with the friction material. (2) The elastic member always presses the driving member and the pressing member together by the elastic force thereof (1).
Electric disc brake according to the item. (3) The driving force transmission device further includes a motion conversion mechanism provided between the motor and the driving member, for converting a rotational motion of the motor into a linear motion of the driving member,
The electric disc brake according to (1) or (2), wherein the pressing member and the driving member are arranged behind the friction material along a straight line crossing the disc. (4) The electric disc brake according to any one of (1) to (3), wherein the elastic member is mainly composed of a metal plate. (5) The electric disc brake according to any one of (1) to (3), wherein the elastic member is mainly formed of an elastic body such as rubber. (6) The electric disc brake according to any one of (1) to (5), wherein the coupling mechanism includes a spherical contact structure that causes the pressing member and the driving member to contact each other with a spherical surface. (7) the coupling mechanism is formed on the pressing member, the first fitting portion is one of the convex portion and the concave portion to be fitted to each other,
The first and second fitting portions contact the second fitting portion formed on the driving member, which is the other of the convex portion and the concave portion, such that the driving member can tilt with respect to the pressing member, and the (1) The electric disc brake according to any one of (1) to (6), including a free fitting structure in which the gap is provided between the first and second fitting portions so as not to hinder the inclination. (8) wherein the pressing member is brought into contact with the rear surface of the friction material such that the pressing member cannot tilt with respect to the friction material.
The electric disc brake according to any one of (1) to (7). (9) The electric disc brake according to any one of (1) to (8), wherein the pressing member is brought into flat contact with the rear surface of the friction material. (10) The structure according to any one of (1) to (9), wherein the structure for attaching the elastic member to the driving member and the pressing member does not have a function of preventing relative rotation between the driving member and the pressing member. The electric disc brake according to 1. The elastic member has a rotation preventing function for preventing relative rotation between the driving member and the pressing member, in addition to a contact maintaining function for maintaining a contact state between the driving member and the pressing member when the electric disk brake vibrates. Is designed to have a contact maintaining function only,
It is difficult to exert the contact maintaining function at a high level. Therefore, according to the disk brake described in this section, it is easy to exert the contact maintaining function at a high level, and as a result, it is possible to satisfactorily suppress a tapping sound when the disk brake vibrates. (11) Of the elastic members, at least one of the first and second mounting portions respectively attached to the driving member and the pressing member is the one corresponding to the driving member and the pressing member utilizing its own elasticity. The electric disc brake according to any one of (1) to (10), which is engaged with the engaging portion.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some specific embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an electric disk brake (hereinafter, simply referred to as "disk brake") 10 according to a first embodiment of the present invention. Disc brake 1
0 is a disk 12 as a rotating body that rotates with the wheels.
It has. Both sides of the disk 12 are friction surfaces 1
4, and a pair of friction pads 20a and 20b are disposed to face the friction surfaces 14. Each friction pad 20
Each of the friction members 22a and 20b has a friction member 22 in contact with each friction surface 14 on the front surface, and a steel back plate 24 is fixed to the rear surface of the friction member 22.

The disc brake 10 includes a pad supporting mechanism 26 and a pad pressing mechanism 28. First, the pad supporting mechanism 26 will be described.

The disc brake 10 has a mounting bracket 30. The mounting bracket 30 is cantilevered and fixedly attached to the vehicle body so as to straddle the disk 12. The mounting bracket 30 includes: (a) a pair of friction pads 20a, 20b each having a friction surface 14 at a position sandwiching the disc 12 from both sides;
(B) a portion (receiving member) that receives a frictional force generated in each of the friction pads 20a, 20b when the friction pad 20a, 20b contacts the disk 12 when the friction pad 20a, 20b contacts the disk 12. ing.

Next, the pad pressing mechanism 28 will be described. The disc brake 10 has a caliper 60. The caliper 60 presses the pair of friction pads 20a and 20b against the disk 12 from both sides thereof while straddling the disk 12. The caliper 60 is movably supported in a direction parallel to the rotation axis of the disk 12 by a pair of pin slide mechanisms (not shown) attached to the mounting bracket 30 in parallel with the rotation axis of the disk 12. The caliper 60 has a pad pressing-related portion 60a, a motor mounting portion 60b, and a support portion 60c.
The motor housing 62 is screwed to the motor mounting portion 60b.

The pad pressing portion 60a has a pressing portion 64 located behind the inner pad 20a located inside the vehicle body and a rear portion of the outer pad 20b located outside the vehicle body. The reaction portion 66 and the pressing portions 6
Connecting part 68 connecting the reaction part 4 and the reaction part 66 to each other
Are formed.

In the pressing portion 64, a pressing member 70 is brought into flat contact with the back surface of the inner pad 20a.
The pressing member 70 is separate from the inner pad 20a. Behind the pressing member 70, an ultrasonic motor 72 is disposed coaxially with the axis of the pressing member 70. Pressing member 70
The ultrasonic motor 72 and the ultrasonic motor 72 are connected by a ball screw mechanism 74 as a motion conversion mechanism.

The ultrasonic motor (hereinafter simply referred to as "motor") 72 is of a traveling wave type. As is well known, the motor 72 applies ultrasonic vibration to the stator 82 to generate a surface wave, and rotates the rotor 84 by a frictional force acting between the stator 82 and the rotor 84. The motor 72 includes a bottomed cylindrical motor housing 62.
The stator 82 and the rotor 84 are accommodated coaxially. The motor 72 can be changed to another motor, for example, a DC motor.

The motor housing 62 has a main body 60a having a through hole at the bottom and a cover 62 for closing the through hole.
b are separate parts from each other and are screwed. The motor housing 62 is screwed to the motor mounting portion 60b at an opening thereof.

The ball screw mechanism 74 is formed by screwing a male screw member (screw shaft) 100 as a "drive member" and a female screw member (screw nut) 102 via a plurality of balls (not shown). ing. The male screw member 100 is limited in rotation but is allowed to move in the axial direction, while the female screw member 102 is allowed to rotate but is limited in axial movement. Specifically, the male screw member 100 is non-rotatably attached to the cover 62b of the motor housing 62 by a spline fitting portion 104 as a rotation preventing portion. On the other hand, the female screw member 102
The radial thrust bearing 106 and the radial bearing 10 are mounted on the caliper 60 and the motor housing 62.
8 and a radial bearing 110 so as to be rotatable and axially immovable. The rotor 84 is attached to the female screw member 104 so as not to rotate relatively.

Therefore, when the rotor 84 rotates forward, the female screw member 102 also rotates forward, and when the female screw member 102 rotates forward, the male screw member 100 moves forward (moves rightward in the drawing) and the pressing member 70 moves in a direction to bring the inner pad 20a closer to the disk 12. Conversely, the rotor 84
When the female screw member 102 rotates in the reverse direction, the male screw member 100 retreats (moves to the left in the figure) when the female screw member 102 rotates in the reverse direction, so that the pressing member 70 moves together with the inner pad 20a. It is allowed to move in a direction away from the disk 12.

A convex partial spherical surface 116 is formed on the front end surface (the right end surface in the figure) of the male screw member 100, and a concave partial spherical surface 118 is formed on the back surface of the pressing member 70 correspondingly. . Male screw member 100 has its partial spherical surface 1
At 16, it is brought into contact with the partial spherical surface 118 of the pressing member 70. The radius of the partial spherical surface 116 is smaller than the radius of the partial spherical surface 118 so that the male screw member 100 and the pressing member 70 abut each other so that the male screw member 100 can tilt with respect to the pressing member 70. Have been.

A concave portion 120 is formed at the center of the partial spherical surface 116 of the male screw member 100, and a convex portion 122 is formed correspondingly at the center of the partial spherical surface 118 of the pressing member 70. The convex portion 122 allows the male screw member 100 to incline with respect to the pressing member 70 in the concave portion 120, but prevents the pressing member 70 from moving parallel to the male screw member 100 in the radial direction. It is inserted. Therefore, when the disc brake 10 is actuated, the pressing member 70 is prevented from moving parallel to the male screw member 100 in the radial direction, and the disc brake 10
When assembling, the pressing member 70 can be easily and accurately positioned with respect to the male screw member 100.

The male screw member 100 and the pressing member 70 are connected by an elastic member 124. The elastic member 124 is
It is composed of at least a pair of leaf springs. Each pair of leaf springs is opposed to each other with a gap in one diameter direction of the male screw member 100. The elastic member 124 is fixedly attached to the rear surface of the pressing member 70 at the base end 126 thereof. Further, the elastic member 124 has a distal end portion 128 with respect to the proximal end portion 126, and
Is elastically deformable in the radial direction of the
Are elastically engaged with the front end of the male screw member 100. The elastic member 124 is designed such that an elastic force in the direction of pressing the male screw member 100 against the pressing member 70 is always generated in a state where the male screw member 100 and the pressing member 70 are in contact with each other. Thereby, it is suppressed that the male screw member 100 is separated from the pressing member 70 in the axial direction at the time of the vibration of the disc brake 10 and a gap is formed therebetween. However,
The elastic member 124 allows the male screw member 100 to be inclined with respect to the pressing member 70.

The distance between each pair of leaf springs is designed to gradually increase at the distal end portion 128 as the distance from the pressing member 70 increases. Thereby, the disc brake 1
0, the male screw member 100 and the pressing member 70
When approaching each other, the male screw member 100 is easily attached to the elastic member 124 with a small force.

Therefore, in this embodiment, since the male screw member 100 can be inclined with respect to the pressing member 70, the motor 72 provides a pair of friction pads 20a, 20b.
The caliper 60 is elastically deformed in a direction in which the reaction portion 66 and the pressing portion 64 are separated from each other, and as a result, the male screw member 100 Even when inclined, the male screw member 100 does not give a bending moment to the pressing member 70. Therefore, the surface pressure of the friction pads 20a, 20b on the contact surface with the disk 12 due to the elastic deformation of the caliper 60 is suppressed from being higher on the outer peripheral side of the friction pads 20a, 20b than on the inner peripheral side, As a result, uneven wear of each of the friction pads 20a and 20b due to such uneven surface pressure is suppressed.

In the present embodiment, as described above, since the male screw member 100 can be inclined with respect to the pressing member 70, the pressing member 70 does not apply a bending moment to the male screw member 100. As a result, the motor 72 can always be operated in a normal state. Male thread member 1
00 is not squeezed in the caliper 60 and the motor housing 62,
4 is not inclined with respect to the stator 82, and as a result, the contact state between the rotor 84 and the stator 82 does not become defective.

In this embodiment, since the male screw member 100 and the pressing member 70 are connected without any intermediate member, the number of parts of the disc brake 10 can be increased. The male screw member 100 and the pressing member 70 can be connected without increasing the directional dimension.

Further, in this embodiment, since the engagement of the male screw member 100 with the pressing member 70 is performed elastically, the connecting operation between the male screw member 100 and the pressing member 70 is facilitated. The assembly work of the disc brake 10 becomes easy.

In this embodiment, since the relative rotation between the male screw member 100 and the pressing member 70 is allowed in the assembled disk brake 10, for example, the pressing member is used to replace the friction pads 20a and 20b. When it is necessary to separate the cover 70 from the inner pad 20a and the cover 62b is rotated integrally with the male screw member 100, the screw member 10 is
0 is separated from the inner pad 20a, so that the pressing member 70 can be separated from the inner pad 20a. As described above, according to the present embodiment, the pad replacement operation can be easily performed.

As is clear from the above description, in the present embodiment, the front end face of the male screw member 100 is
Contact structure and elastic member 1 for making spherical contact with the back of 0
And 24 together form a “coupling mechanism”;
The coupling mechanism, the pressing member 70, and the male screw member 100 cooperate with each other to form a "driving force transmission device".

Next, a disc brake 200 according to a second embodiment of the present invention will be described. However, this embodiment has many elements in common with the first embodiment described above, and differs only in the element that connects the pressing member and the external thread member to each other. Therefore, only the element will be described in detail, and other elements will be described. For, the same reference numerals are used to omit a detailed description.

As shown in FIG.
At 0, the pressing member 202 is shaped to have a recess 204 on its back. This recess 204
The distal end portion of the male screw member 206 is fitted in such a state that the distal end surface thereof contacts the bottom surface of the concave portion 204. A convex partial spherical surface 208 is formed on the distal end surface, and a concave partial spherical surface 210 is formed on the bottom surface.
Is smaller than the radius of the partial spherical surface 210.
Further, a gap 212 is formed between the outer peripheral surface of the distal end portion of the male screw member 206 and the inner peripheral surface of the concave portion 204 of the pressing member 202.
The male screw member 206 and the pressing member 202 are formed in a size that does not hinder the predetermined inclination.

The female screw member 102 of the male screw member 206
An annular groove 214 is formed in a portion protruding from the groove.
The male screw member 206 and the pressing member 202 are elastic members 216
Are connected by This elastic member 216 is also composed of at least one pair of leaf springs as in the first embodiment. The elastic member 216 is attached to the pressing member 202 at a base end thereof, and has a plurality of convex portions 218 extending inward facing each other at the distal end.
Are formed. When the convex portion 218 is fitted into the annular groove 214, the pressing member 202 and the male screw member 20 are inserted.
6 are resiliently connected.

In the present embodiment, a recess 220 is formed in the front surface of the pressing member 202, that is, in the center of the surface in contact with the inner pad 20a. This is because it may be more effective to locally contact the inner pad 20a only at an appropriate position than to contact the inner pad 20a on the entire front surface, in order to optimize the surface pressure distribution of the inner pad 20a.

Next, a disc brake 300 according to a third embodiment of the present invention will be described. However, this embodiment has many elements in common with the previous second embodiment, and differs only in the element that connects the pressing member and the external thread member to each other. Therefore, only the element will be described in detail, and other elements will be described. For, the same reference numerals are used to omit a detailed description.

As shown in FIG. 3, an annular groove 302 is formed on the inner peripheral surface of the concave portion 210 of the pressing member 202. The annular groove 302 is formed along one circumference centering on the axis of the pressing member 202. A rubber ring 304 is mounted in the annular groove 302. The inner diameter of the ring 304 is slightly larger than the outer diameter of the male screw member 306,
The tip of the male screw member 306 is press-fitted into a through hole of the ring 304. The ring 304 is elastically pressed against the outer peripheral surface of the male screw member 306, and
6 is not displaced from the ring 304. Therefore, when the male screw member 306 attempts to separate from the pressing member 202, an elastic force for suppressing the separation is generated in the ring 304. As a result, the male screw member 306 and the pressing member 20
2 is maintained in contact. That is, in the present embodiment, the ring 304 constitutes an “elastic member”, and the ring 304 and the portion of the male screw member 306 and the pressing member 202 related to the ring 304 cooperate with each other to “press”. It constitutes a mechanism.

Although some embodiments of the present invention have been described in detail with reference to the drawings, various modifications may be made based on the knowledge of those skilled in the art without departing from the scope of the claims. Of course, the present invention can be implemented in an improved form.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an electric disc brake according to a first embodiment of the present invention.

FIG. 2 is a side sectional view showing an electric disc brake according to a second embodiment of the present invention.

FIG. 3 is a side sectional view showing an electric disc brake according to a third embodiment of the present invention.

[Explanation of symbols]

 10, 200, 300 Electric disc brake 12 Disc 22 Friction material 70, 202 Pressing member 72 Ultrasonic motor 100, 206, 306 Male thread member 102 Female thread member 124, 216 Elastic member 304 Ring

Claims (1)

[Claims] 1. A disk rotating with a wheel, a friction material pressed against the disk to suppress the rotation of the disk, a motor, and a driving force transmission device for transmitting a driving force of the motor to the friction material. (A) a drive member which is inseparably connected to a motor and driven by the motor; and (b) a friction member is actuated by the drive member between the drive member and the friction member to receive the friction material from the disk. (C) a connecting mechanism for connecting the driving member and the pressing member so that the driving force of the motor is transmitted to the pressing member via the driving member; and The driving member and the pressing member are elastically connected by an elastic member so that the driving member is tiltably contacted with the pressing member, and the contact state is maintained during the vibration of the electric disk brake. Electric disc brake which comprises a driving force transmission device and a connecting mechanism for.