JP2001099203A - Dynamo-electric disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable compactness while preventing generation of interference with a circumferential member. SOLUTION: A lower outer peripheral part 9a and an upper outer peripheral part 9b of a caliper body 9 is formed in a flat shape such that the former 9a may be formed in a shape more resembling to the shape of a drive shaft while the latter 9b may be formed in a shape more resembling to the shape of the inner peripheral part of a wheel being substantially planar, whereby prevention of interference between the body 9, the drive shaft and the wheel can be attained by restraining a gap to the minimum between the part 9a and the drive shaft and a gap between the part 9b and the substantially planar inner peripheral part of the wheel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric disc brake for generating a braking force by the rotation of an electric motor.

[0002]

2. Description of the Related Art As a braking device for a vehicle such as an automobile, for example, a so-called "dry brake" device is known which generates a braking force by an output of an electric motor without using a hydraulic output by a brake fluid.

[0003] As a dry brake device, for example, an electric disk in which the rotational motion of an electric motor is converted into forward and backward movement of a piston by a motion converting mechanism and a brake pad is pressed against the disk rotor by the piston to generate a braking force. There is a brake. In this type of electric disc brake, a brake pedal depression force (or displacement amount) by a driver is detected by a sensor, and a controller controls the rotation of the electric motor according to the detection to obtain a desired braking force. ing.

In the above-described electric disc brake, various sensors are used to determine the rotational speed of each wheel,
By detecting vehicle conditions such as vehicle speed, vehicle acceleration, steering angle, and vehicle lateral acceleration, and controlling the rotation of the electric motor based on these detections by a controller, boost control, antilock control, traction control, and vehicle Stabilization control and the like can be incorporated relatively easily. FIGS. 5 and 6 show examples of the above-described electric disc brake.
There are the following.

[0005] This electric disc brake 1 has a pair of brake pads 3, 3 arranged on both sides of a disc rotor 2.
4, a piston 5 provided to face one of the pair of brake pads 3 and 4 (the brake pad 3), an electric motor 8 in which a motor rotor 6 is housed in a stator 7 (a so-called adduction type), A caliper body 9 for accommodating an electric motor 8, a claw 10 fixed to the caliper body 9 and straddling the disk rotor 2 and facing the other of the pair of brake pads 3 and 4 (brake pad 4); And a motion converting mechanism 12A for converting the rotational motion of the piston 6 into a linear motion to move the piston 5 forward and backward. A part of the motion converting mechanism 12A is housed in the motor rotor 6. Further, the stator 7 is formed in a substantially cylindrical shape, and as a result, as shown in FIG. 6, the outer peripheral shape of the motor rotor 6 in the stator 7 as viewed from the axial direction (hereinafter referred to as the axial direction) is circular. Furthermore, the caliper body 9 is
Are stored in a state of being in close contact with each other, and the shape viewed from the axial direction is circular.

[0006]

By the way, in the above-mentioned prior art, the caliper body 9 has a substantially circular outer peripheral shape viewed from the axial direction of the disk rotor 2 due to the shape of the stator 7. On the other hand, the claw portion 10 is
The outer peripheral shape viewed from the axial direction is substantially rectangular from the relationship between the shapes of the brake pads 3 and 4. The caliper main body 9 and the claw portion 10 have a radial length of the disk rotor 2 as viewed from the axial direction of the disk rotor 2, in addition to the difference in the outer peripheral shape, the motor rotor 6 of the caliper main body 9. , As shown in the above prior art,
Since a part of 12A is stored, the caliper body 9 has to be longer than the claw portion 10. Therefore, when this type of electric disc brake is installed on the vehicle body, the caliper main body 9 does not interfere with the surrounding members (for example, a drive shaft or the like that is disposed radially inward of the disc rotor 2 with respect to the caliper main body 9). In this manner, the disk rotor 2 is compactly arranged as close as possible to the peripheral member in the radial direction. However, due to the radial length relationship between the caliper main body 9 and the claw portion 10, a space is formed between the claw portion 10 and the surrounding member in the radial direction of the disk rotor 2. As a result, although there is room for installing the claw portion 10 as close as possible to the peripheral member in the radial direction of the disk rotor 2, due to the difference in the radial length between the caliper body 9 and the claw portion 10, The claw portion 10 can no longer be brought closer to the surrounding member in the radial direction of the disk rotor 2, and can be installed in consideration of the difference in the radial length between the caliper body 9 and the claw portion 10. In addition, there is also a restriction, which hinders the compactness of the brake device including the disk rotor 2.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an electric disc brake capable of preventing interference with surrounding members and reducing the size of the apparatus.

[0008]

According to the first aspect of the present invention,
A pair of brake pads arranged on both sides of the disk rotor, a piston provided to face one of the pair of brake pads, an electric motor in which the motor rotor is housed in a stator, and a caliper body in which the electric motor is housed. ,
A claw portion provided integrally with the caliper body and straddling the disk rotor and facing the other of the pair of brake pads; and a motion conversion mechanism for converting the rotational motion of the motor rotor into a linear motion to advance and retract the piston. Wherein the stator has a substantially cylindrical shape whose outer peripheral shape is non-circular when viewed from the axial direction of the motor rotor, and the caliper main body has a shape along the stator. According to a second aspect of the present invention, in the configuration according to the first aspect, the outer peripheral shape of the stator as viewed from the axial direction of the motor rotor includes two arcs each including the two chords from a circle having two chords opposed to each other. Is cut off. The invention according to claim 3 is
3. The configuration according to claim 2, wherein one of the two strings has an outwardly concave shape, and the other has an outwardly convex shape. According to a fourth aspect of the present invention, in the configuration of the first aspect, the outer peripheral shape of the motor rotor in the stator as viewed from the axial direction is a shape obtained by cutting an arc including the chord from a circle having one chord. Features.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, an electric disc brake 1 according to the first embodiment has a caliper body provided on one side (usually inside the body) of a disc rotor 2 which rotates together with wheels (not shown). A claw 10 formed substantially in a C shape and extending to the opposite side across the disk rotor 2 is integrally connected to the caliper body 9 by a bolt (not shown). Both sides of the disk rotor 2,
That is, the brake pads 3 and 4 are provided between the disk rotor 2 and the caliper body 9 and between the tip of the claw portion 10 respectively. The brake pads 3 and 4 are supported by a carrier (not shown) fixed to the vehicle body so as to be movable along the axial direction of the disk rotor 2, and receive braking torque by the carrier.
The caliper body 9 is slidably guided along the axial direction of the disk rotor 2 by a slide pin (not shown) attached to the carrier. Also, the caliper body 9
Is arranged so that its lower part (the lower part in FIG. 2) faces the drive shaft (not shown), and its upper part (the upper part in FIG. 2) faces the inner periphery of the wheel (not shown). Has become.

An electric motor 8 (DD motor) is provided in the caliper body 9 to which the annular flange portion 10A of the claw portion 10 is connected.
And a rotation detector 11, and a ball lamp unit.
12 is the electric motor 8 from the annular flange 10A side of the claw 10
Are inserted in the motor rotor 6. Caliper body 9
A cover 14 is attached to a rear end portion of the vehicle by bolts (not shown).

The electric motor 8 comprises a substantially cylindrical stator 7 fixed substantially in close contact with the inner peripheral portion of the caliper body 9,
The motor rotor 6 is rotatably supported by slide bearings 15 and 16 on the caliper body 9 so as to face the inner peripheral portion of the stator 7 and is movably supported in the axial direction.

As shown in FIG. 2, the stator 7 connects two stator main portions 71, 71 which are substantially arcuate and have the same shape and are arranged opposite to each other, and connects the two stator main portions 71, 71 to each other. And two first and second stator sub-portions (spacers) 72 and 73 having the same shape. First and second stator sub-portions (the lower one in FIG. 2 is referred to as a first stator sub-portion and the upper one is referred to as a second stator sub-portion).
Reference numerals 2 and 73 denote arcs on the inner peripheral side when viewed from the axial direction of the motor rotor 6 (front and back sides in FIG. 2; hereinafter, referred to as axial direction), and outer peripheral sides (outer peripheral portions) 72a and 73a are linear. The outer peripheral surface portions 72b, 73b on the lower side and the upper side in FIG. 2 including the outer peripheral portions 72a, 73a are flat.

The stator 7 includes first and second stator sub-portions.
Since the outer peripheral surfaces 72b and 73b have flat outer peripheral surface portions 72b and 73b, the outer peripheral shapes viewed from the axial direction are opposite to each other.
2 is a shape obtained by cutting out two arcs each including the two strings from a circle having two strings (outer peripheral portions 72a, 73a). FIG. Has become. Further, the caliper body 9 for accommodating the stator 7 in close contact therewith has a shape along the stator 7, and corresponds to the lower and upper outer peripheral surfaces 72b, 73b in FIG. 9b, the outer peripheral shape viewed from the axial direction is a shape obtained by cutting two arcs each including the two chords from a circle having two chords opposed to each other. And the caliper body 9
Is arranged such that its lower outer peripheral surface 9a faces a drive shaft (not shown) and its upper outer peripheral surface 9b faces the planar inner peripheral portion of a wheel (not shown). I have.

The rotation detector 11 includes a resolver stator 18 fixed to a resolver case 17 attached to the caliper body 9 by bolts (not shown), and a resolver stator 18.
A substantially cylindrical resolver presser 19 is attached to the motor rotor 6 so as to face the motor rotor 6.
A resolver rotor 19 fixed via A is provided, and the rotational speed (number of rotations) of the motor rotor 6 is detected based on the relative rotation of these resolvers. A connector 20 and a cable 21 connected to the electric motor 8 and the rotation detector 11 are attached to the cover 14, and the electric motor 8 responds to a control signal (electric signal) from a controller (not shown). Thus, the motor rotor 6 can be rotated by a desired angle at a desired torque. The connector 20 and the cable 21 are inclined with respect to the axial direction of the disk rotor 2 and extend radially outward to avoid interference with members such as arms, links, knuckles, and struts of the suspension device of the vehicle. Have been.

The ball lamp unit 12 includes an electric motor 8
A ball ramp mechanism 22 for converting the rotational motion of the motor rotor 6 into a linear motion, the piston 5 for pressing the brake pad 3, and an adjusting nut 23 interposed therebetween.
And a limiter mechanism 24 for transmitting the rotation of the ball ramp mechanism 22 to the adjustment nut 23.

The ball ramp mechanism 22 is in contact with the flange 10A of the claw 10 and is fixed to the claw 10 so as not to rotate by a pin (not shown). Movable disk 26,
And a ball 27 (steel ball) interposed between them. The movable disk 26 is integrally formed with a cylindrical portion 28 that is inserted into the fixed disk 25 and extends to the inside of the caliper body 9. The cylindrical portion 28 is spline-coupled to the inner peripheral portion of the motor rotor 6, and these spline-coupled portions 28A are fixed in the rotational direction and the radial direction in consideration of the slidability in the axial direction, dimensional tolerance and assembly. Play is provided.

On the opposing surfaces of the fixed disk 25 and the movable disk 26, three ball grooves 29, 30 are formed, each extending in an arc along the circumferential direction, and the ball 27 is inserted between them. The relative rotation of the fixed disk 25 and the movable disk 26 causes the three balls 27 to form ball grooves.
The fixed disk 25 and the movable disk 26 move relative to each other in the axial direction according to the rotation angle by rolling in the insides 29 and 30.

The adjusting nut 23 comprises a cylindrical portion 31 and a flange portion 32 formed outside the one end (the left side in FIG. 1). The cylindrical portion 31 is inserted through the cylindrical portion 28 of the movable disk 26.
It is rotatably supported by a plain bearing 33 and has a flange 32
Abuts against one end of the movable disk 26 and is rotatably supported by a thrust bearing 34. The cylindrical portion 31 of the adjusting nut 23 extends to the inside of the motor rotor 6 in the caliper body 9, and a limiter mechanism 24 is mounted on the outer periphery of the distal end portion.

The limiter mechanism 24 includes a cylindrical portion of the adjustment nut 23.
A substantially cylindrical limiter 35 and a substantially cylindrical spring holder 36 are rotatably fitted to the outer periphery of the distal end portion of the 31, and are connected to each other by a coil spring 37. The limiter 35 and the spring holder 36 are engaged with each other so that they can rotate relative to each other within a predetermined range, and a predetermined set load is applied in the rotation direction by the coil spring 37. Thus, it can rotate clockwise (clockwise as viewed from the left in FIG. 1) against the set load of the coil spring 37.
The engagement recess 35A formed in the limiter 35 is
The limiter 35 is rotatable within a predetermined range with respect to the cylindrical portion 28. Adjustment nut 23
The outer periphery of the tip of the cylindrical portion 31 has a clutch spring 38
(Coil spring) is wound, and one end thereof is connected to the spring holder 36.
Acts as a one-way clutch by expanding and contracting the diameter by torsion, and transmits only the clockwise rotation of the spring holder 36 to the cylindrical portion 31 of the adjustment nut 23.

The piston 5 is screwed into a screw portion 39 formed on the inner peripheral portion of the adjusting nut 23, and advances toward the brake pad 3 when the adjusting nut 23 rotates clockwise with respect to the piston 5. It has become. In the cylindrical portion 31 of the adjusting nut 23, a detent rod 40, one end of which is fixed to the resolver case 17 by a nut 40A, is inserted. The other end of the detent rod 40 can slide on the piston 5 in the axial direction. And is engaged so as to restrict rotation. A plurality of disc springs 43 are interposed between a flange portion 41 formed in an intermediate portion of the rotation preventing rod 40 and a flange portion 42 formed in the cylindrical portion 31 of the adjustment nut 23, and the spring force is provided. The adjustment nut 23 is urged rightward in FIG. And the detent rod 40 by the nut 40A
The urging force (set load of the disc spring 43) on the adjustment nut 23 can be adjusted by moving the position in the axial direction.

The ball ramp mechanism 22, the adjusting nut 23, and the piston 5 are provided with a case 44 for covering them and integrally sub-assembling the ball ramp unit 12. Flange on front end of case 44 and adjustment nut
A wave washer 45 is interposed between the flange portion 32 and the flange portion 32 so as to provide an appropriate resistance to the rotation of the adjustment nut 23. In FIG. 1, reference numeral 46 denotes a piston boot.

In the electric disc brake 1 configured as described above, the lower outer peripheral surface portion 9a of the caliper body 9 faces (approaches) a drive shaft (not shown), and the upper outer peripheral surface portion 9b is a wheel (shown). (Omitted) so as to face (close to) the substantially planar inner peripheral portion. In the electric disc brake 1, the caliper body 9 along the stator 7 has a flat shape on the upper and lower sides in FIG. 2, and the radial length of the disc rotor 2 viewed from the axial direction of the disc rotor 2 (FIG. Vertical length)
And the length of the substantially rectangular claw portion 10 in the radial direction of the disk rotor 2 as viewed from the axial direction of the disk rotor 2 is almost the same. For this reason, as described above, the circumference of the caliper body 9 in the radial direction of the disk rotor 2 is prevented so as not to interfere with the substantially planar inner peripheral portion (peripheral member) of the drive shaft (not shown) and the wheel (not shown). When the disk rotor 2 is compactly arranged as close as possible to the member, almost no space is formed between the claw portion 10 and the peripheral member in the radial direction of the disk rotor 2, that is, both the caliper body 9 and the claw portion 10 It will be arranged close to the peripheral member. Therefore, the brake device including the disk rotor 2 can be downsized. Furthermore, in the first embodiment, the lower and upper outer peripheral surface portions 9a and 9b of the caliper main body 9 are formed in a planar shape, and the lower outer peripheral surface portion 9a has a shape more (closer) to the drive shaft. At the same time, since the upper outer peripheral surface portion 9b has a shape more closely (closer) to the substantially planar inner peripheral portion (not shown) of the wheel, interference between the caliper body 9 and the drive shaft and the wheel is prevented. The gap between the lower outer peripheral surface portion 9a and the drive shaft facing the lower outer peripheral surface portion 9a and the substantially planar inner peripheral portion of the wheel facing the upper outer peripheral surface portion 9b and the upper outer peripheral surface portion 9b ( (Not shown) can be achieved by minimizing the necessary gap, and the overall size of the apparatus can be reduced accordingly.

A ball ramp mechanism (motion conversion mechanism)
The cylindrical portion 28 of the movable disk 26 and the cylindrical portion 31 of the adjusting nut 23 are housed in the motor rotor 6, and there are restrictions on reducing the diameter of the motor rotor 6. Although it was difficult to make the disc brake 1 compact and prevent interference with surrounding members, according to the present embodiment, the motor rotor 6 is not reduced (that is, the motion conversion mechanism) as described above. Of this electric disc brake 1
And the interference with surrounding members can be prevented, and the function of the electric brake (dry brake) can be maintained satisfactorily.

The movable disk of the ball ramp mechanism 22
The cylindrical portion 28 of the cylinder 26 and the cylindrical portion 31 of the adjustment nut 23 are housed in the motor rotor 6, and the diameter of the motor rotor 6 increases accordingly, and the diameter of the piston 5 operated via the ball ramp mechanism 22 is reduced. It becomes easy to obtain the desired thrust by making it larger. Further, as described above, the cylindrical portion 28 of the movable disk 26 of the ball ramp mechanism 22, the cylindrical portion 31 of the adjustment nut 23, and the like are housed in the motor rotor 6, the diameter of the motor rotor 6 is increased, and the motor torque is reduced. Since it is proportional to the square of the diameter of the motor rotor 6, a large motor torque can be obtained, and accordingly, in order to obtain a desired motor torque, the axial length of the motor rotor 6 can be shortened. Accordingly, the electric motor 8 and thus the electric disc brake 1 can be made compact.

During braking, when the motor rotor 6 of the electric motor 8 rotates clockwise with a predetermined torque in response to a signal from a controller (not shown), the spline coupling portion 28
The movable disk 26 of the ball ramp mechanism 22 rotates through A, and the ball 27 rolls along the ball grooves 29 and 30 to advance the movable disk 26 toward the brake pad 3 along the axial direction. This thrust is applied to the adjustment nut 23 via the thrust bearing 34.
Is transmitted to the piston 5 via the screw portion 39, and the one brake pad 3 is
The caliper body 9 moves along the slide pin of the carrier due to the reaction force, and the claw portion 10 presses the other brake pad 4 against the disk rotor 2, and the braking force according to the torque of the electric motor 8. Occurs.

At this time, the ball groove of the ball ramp mechanism 22
By reducing the inclination of 29 and 30, the lead for the rotational displacement can be set sufficiently small, so that the boosting ratio can be increased, the output of the electric motor 8 can be small, and the power consumption can be reduced. The size of the motor can be reduced.

A ball ramp mechanism 22 for driving the brake pads 5 and 6 on both sides of the disk rotor 2 is disposed adjacent to the disk rotor 2 and is fixed inside the substantially C-shaped claw 10. By arranging the electric motor 8 on the outside, the distance between the ball ramp mechanism 22 and the brake pads 3 and 4 can be sufficiently reduced, and the thrust can be directly transmitted by the claw portion 10. As a result, the caliper body 9 of the electric motor 8 does not directly receive the load at the time of braking, so that the caliper body 9 can be made thinner and lighter materials can be used, and the weight reduction and the heat dissipation of the electric motor 8 are promoted. be able to. In addition, since the reaction force during braking does not directly act on the bearing of the motor rotor 6, the structure of the bearing of the electric motor 8 can be simplified.

When the brake is released, the electric motor 8 is rotated in the reverse direction, and the movable disk 26 is rotated counterclockwise to the original position, and the movable disk 26, the adjusting nut 23 and the piston 5 are retracted by the spring force of the disc spring 43. Then, the brake pads 3, 4 are separated from the disk rotor 2, and the braking is released.

Next, compensation of wear of the brake pads 3 and 4 will be described. When there is no wear on the brake pad 3 or after the wear adjustment described later has been performed, the rotation of the motor rotor 6 causes the piston 5 to move from the non-braking position A (not shown) to the pad clearance C (not shown) during braking. When the brake pad 3 advances to the braking start position B (not shown) where the brake pad 3 abuts on the disk rotor 2, the engaging projection 28 B of the cylindrical portion 28 of the movable disk 26 is moved along the engaging recess 35 A of the limiter 35. It rotates and moves from one end to the other end of the engagement recess 35A.

Further, when the piston 5 presses the brake pad 3 against the disk rotor 2 and moves to the braking position D (not shown), the engaging projection 28B rotates the limiter 35 clockwise, and the rotational force is applied to the coil. It is transmitted to the adjustment nut 23 via the spring 37 and the clutch spring 38. At this time, since the piston 5 is pressing the brake pad 3 and a large frictional force is generated in the screw portion 39 between the piston 5 and the adjusting nut 23, the coil spring 37 is bent and the adjusting nut 23 does not rotate. . And at the time of braking release,
When the piston 5 retreats to the non-braking position A due to the reverse rotation of the movable disk 26, the engagement projection 28B abuts against one end of the engagement recess 35A to rotate the limiter 35 and the spring holder 36 counterclockwise. The piston 5 does not rotate because the clutch spring 38 expands in diameter and idles. In this way, pad wear is not adjusted and constant pad clearance is maintained.

When the brake pad 3 is worn, the brake pad 3 is moved from the non-braking position A to the pad clearance C by the clockwise rotation of the motor rotor 6 during braking.
To the position B, and the engaging projection 28B is
Even when moving from one end to the other end of A, the piston 5 does not press the brake pad 3 due to the wear W (not shown). When the motor rotor 6 further rotates, the movable disk
26 and the adjusting nut 23 advance to the position D toward the disk rotor 2 and the piston 5 causes the brake pad 3 to abut on the disk rotor 2. During this time, the engagement projection 28B is
35 is rotated clockwise, the rotational force of which is adjusted via the coil spring 37 and the clutch spring 38.
But the piston 5 is not pressing the brake pad 3 and the threaded portion between the piston 5 and the adjustment nut 23
Since a large frictional force is not generated at 39, the adjustment nut 23 rotates clockwise to further advance the piston 5 toward the brake pad 3 to adjust the wear of the pad.

When the piston 5 moves to a position E (not shown) for pressing the brake pad 3 against the disk rotor 2, a large frictional force is generated in the screw portion 39 between the piston 5 and the adjustment nut 23. Then, the coil spring 37 is bent, and the rotation of the adjustment nut 23 is stopped. When the piston 5 retreats to the non-braking position A due to the counterclockwise rotation of the motor rotor 6 at the time of braking release, the engaging projection 28
B contacts one end of the engagement recess 35A to rotate the limiter 35 counterclockwise, but the clutch nut 38 expands and idles, so that the adjustment nut 23 does not rotate. In this way, the clearance W between the brake pad 3 and the piston 5 at the non-braking position caused by the wear is equal to the predetermined value W '.
[Not shown], the brake pad 3
The piston 5 is operated only once by a certain percentage of the wear
Can be advanced from the adjustment nut 23 to the brake pad 3 side. By repeating this, the wear of the pad can be adjusted.

As described above, a pad wear adjusting member such as the cylindrical portion 31, the limiter 35, the spring holder 36, the coil spring 37, and the clutch spring 38 of the adjusting nut 23 is provided to adjust the wear of the pad. However, the wear adjusting member of this pad is housed in the motor rotor 6, which is a restriction in reducing the diameter of the motor rotor 6, and a part of the motion conversion mechanism is inside the motor rotor 6 as described above. In addition to being housed, it is more difficult to reduce the diameter of the motor rotor 6 to make the electric disc brake 1 compact and prevent interference with surrounding members. On the other hand, in the present embodiment, the motor rotor 6 accommodating the pad wear adjusting member for performing pad wear adjustment is not reduced in diameter as described above (that is, the pad wear adjusting member is replaced with the motor rotor 6). The electric disc brake 1 can be made compact and interference with surrounding members can be prevented.
The function (wear adjustment function) of the electric brake (dry brake) can be maintained well.

Instead of the first embodiment, the stator 7 and the caliper body 9 of the electric motor 8 may be constructed as shown in FIG. 3 (for convenience, referred to as a second embodiment).
The second embodiment is used when a wheel (not shown) has an inner peripheral portion having a substantially concave shape (a shape along an upper outer peripheral surface portion 9d described later). The stator 7 according to the second embodiment has a substantially arc-shaped two stator main portions 71, 71 disposed so as to face each other, and a second stator main portion 71, 71 disposed so as to connect the two stator main portions 71, 71. 1, and a second stator sub-portion (spacer) 74, 75.

The outer peripheral surface portion 74a (the lower side in FIG. 3) of the first stator sub-portion 74 has a shape that is concave toward the inner peripheral side when viewed from the axial direction (the front and back direction in FIG. 3), and extends in the axial direction. It has become. The outer peripheral surface portion 75a (upper side in FIG. 3) of the second stator sub-portion 75 has an outwardly convex shape as viewed in the axial direction, and has a shape extending in the axial direction.

In the stator 7, the outer peripheral surface portion 74a of the first stator sub-portion 74 is concave toward the inner peripheral side, and the outer peripheral surface portion 75a of the second stator sub-portion 75 is outwardly convex. The outer peripheral shape viewed from the axial direction is the two opposing chords (the line segment obtained by viewing the outer peripheral surface portion 74a from the axial direction and the outer peripheral surface portion).
75a is a shape obtained by cutting out two arcs each including the two chords from a circle having a line segment obtained by looking at the axial direction, and one of the two chords (the outer peripheral surface portion 74a is viewed from the axial direction). The other (the line segment obtained by viewing the outer peripheral surface 75a from the axial direction) has an outwardly convex shape.

The caliper body 9 for accommodating the stator 7 in close contact therewith is substantially cylindrical and has a concave outer peripheral surface 74.
a and a lower peripheral surface portion 9c, 9d corresponding to the convex outer peripheral surface portion 75a. The outer peripheral shape viewed from the axial direction is such that the lower outer peripheral surface portion 9c is outwardly concave, and Outer peripheral surface
9d is formed convexly outward. The caliper body 9 has a lower outer peripheral surface portion 9c facing a drive shaft (not shown), and an upper outer peripheral surface portion 9d having a substantially concave shape of a wheel (not shown) (a shape along the upper outer peripheral surface portion 9d). Is arranged so as to face the inner peripheral portion of the vehicle.

In the second embodiment configured as described above, the caliper main body 9 along the shape of the stator 7 has a length in the radial direction of the disk rotor 2 as viewed from the axial direction of the disk rotor 2 (the vertical direction in FIG. 3). The length of the disk rotor 2 in the radial direction of the disk rotor 2 as viewed from the axial direction of the disk rotor 2 in the substantially rectangular claw portion 10 is almost eliminated.
Therefore, as described above, the caliper body 9 does not interfere with the substantially concave inner peripheral portion (peripheral member) of the drive shaft (not shown) and the wheel (not shown), so that the caliper main body 9 extends radially around the disk rotor 2. When the disk rotor 2 is compactly arranged as close as possible to the member, almost no space is formed between the claw portion 10 and the peripheral member in the radial direction of the disk rotor 2, that is, both the caliper body 9 and the claw portion 10 It will be arranged close to the peripheral member. Therefore, the brake device including the disk rotor 2 can be downsized. Further, in the second embodiment, the lower outer peripheral surface 9c of the caliper body 9 is formed in a concave shape, and the lower outer peripheral surface 9c is formed on the drive shaft (not shown) as compared with the first embodiment. Since the shape becomes more conformal, prevention of interference between the caliper body 9 and the drive shaft and the wheel is performed by a lower outer peripheral surface portion.
The gap between the drive shaft 9c and the drive shaft facing the lower outer peripheral surface portion 9c can be made smaller than in the first embodiment, and the entire device can be downsized accordingly. be able to. Also, the upper outer peripheral surface portion 9d
Has a shape that is outwardly convex when viewed from the axial direction and extends along a substantially concave inner peripheral portion of a wheel (not shown) facing the upper outer peripheral surface portion 9d. The outer peripheral surface 9d of the wheel and the substantially concave inner peripheral portion of the wheel facing the upper outer peripheral surface 9d need a gap between the upper outer peripheral surface 9d and the substantially concave inner peripheral portion of the wheel. This can be minimized, and the entire device can be made more compact.

The stator 7 and the caliper body 9 of the electric motor 8 may be configured as shown in FIG. 4 (for convenience, referred to as a third embodiment). In the third embodiment,
This is used when the wheel (not shown) has an inner peripheral portion of a substantially concave arc (shape along the upper outer peripheral surface portion 9f described later). The stator 7 according to the third embodiment includes an arc-shaped stator main portion 76 with a part missing, and a stator main portion 76.
And a stator sub-portion (spacer) 77 provided so as to fill the missing portion. The stator sub-portion 77 has a circular arc on the inner peripheral side and a linear outer peripheral side (outer peripheral portion) 77a when viewed from the axial direction (the direction of the front and back in FIG. 4), and an outer peripheral portion including the outer peripheral portion 77a. 77b is flat.

Since the stator 7 has the flat outer peripheral surface portion 77b, the outer peripheral shape viewed from the axial direction is as follows.
It has a shape obtained by cutting out an arc including the string (outer peripheral portion 77a) from a circle having one opposing chord (outer peripheral portion 77a). The caliper body 9 along the shape of the stator 7
It has an outer peripheral surface portion (lower outer peripheral surface portion) 9e having a shape corresponding to the outer peripheral surface portion 77b, and the outer peripheral shape viewed from the axial direction is a shape obtained by cutting an arc including the chord from a circle having one chord. I have. Then, the caliper body 9 has a lower (outer side in FIG. 4) outer peripheral surface portion 9e attached to a drive shaft (not shown).
, And an arc-shaped (convex) upper outer peripheral surface portion 9f is arranged so as to face a concave inner peripheral portion (not shown) of the wheel.

In the third embodiment configured as described above, the caliper body 9 shaped along the stator 7 has a length in the radial direction of the disk rotor 2 viewed from the axial direction of the disk rotor 2 (the vertical direction in FIG. 4). The length of the disk rotor 2 in the radial direction of the disk rotor 2 as viewed from the axial direction of the disk rotor 2 in the substantially rectangular claw portion 10 is almost eliminated.
For this reason, as described above, the caliper main body 9 is disposed in the radial direction of the disk rotor 2 so as not to interfere with the inner peripheral portion (peripheral member) of the substantially concave arc of the drive shaft (not shown) and the wheel (not shown). When the compact member is arranged as close as possible to the surrounding member, almost no space is formed between the claw portion 10 and the surrounding member in the radial direction of the disk rotor 2, that is, the caliper body 9 and the claw portion 10 Both will be arranged close to the peripheral member. Therefore, the brake device including the disk rotor 2 can be downsized. Further, in the third embodiment, the lower outer peripheral surface portion 9e of the caliper main body 9 has a planar shape, and the lower outer peripheral surface portion 9e has a shape substantially along a drive shaft (not shown). 9 and the drive shaft can be prevented by reducing the clearance between the lower outer peripheral surface portion 9e and the drive shaft facing the lower outer peripheral surface portion 9e. Can be made more compact. Further, the upper outer peripheral surface portion 9f has an outwardly convex shape when viewed from the axial direction, and extends along a substantially concave inner peripheral portion of a wheel (not shown) facing the upper outer peripheral surface portion 9f. The upper outer peripheral surface portion 9f and the substantially concave inner peripheral portion of the wheel facing the upper outer peripheral surface portion 9f receive the interference, and the upper outer peripheral surface portion 9f and the substantially concave inner peripheral portion of the wheel. Can be minimized to a necessary minimum, and the entire apparatus can be downsized accordingly.

[0043]

According to the first aspect of the present invention, the caliper body along the stator has a non-circular outer peripheral shape as viewed from the axial direction of the disk rotor, and is viewed from the axial direction of the disk rotor in the caliper body. It is possible to shorten the radial length of the disk rotor so that there is almost no difference from the radial length of the disk rotor viewed from the axial direction of the disk rotor in the substantially rectangular claw portion,
With this configuration, when the caliper body is compactly arranged as close as possible to the peripheral member in the radial direction of the disk rotor so as not to interfere with the peripheral member, the claw portion and the peripheral portion are arranged in the radial direction of the disk rotor. Little space is formed between the member and the member, that is, both the caliper body and the claw portion are arranged close to the peripheral member. Therefore, the brake device including the disk rotor can be downsized.

According to the second aspect of the present invention, the outer peripheral shape of the stator viewed from the axial direction of the motor rotor is a shape obtained by cutting two arcs respectively including the two chords from a circle having two chords opposed to each other. The surface portion corresponding to the two chords in the caliper body shaped along the stator has a planar shape. Therefore, by disposing the caliper body with one of the two planar surfaces facing the drive shaft, the gap between the drive shaft and the caliper can be reduced to avoid interference with the drive shaft. As a result, the entire apparatus can be made more compact. In addition, by disposing the caliper body such that the other of the two planar surfaces of the caliper body faces a planar portion (for example, a planar inner peripheral portion of a wheel) disposed around the caliper body. The gap between the parts can be reduced.

According to the third aspect of the present invention, the surface of the caliper body corresponding to one of the two strings having a concave shape has a concave shape extending in the axial direction, and faces the surface. Since the shape is more in line with the drive shaft, interference with the drive shaft can be prevented by reducing the gap between the drive shaft and the device, and the overall device can be made more compact. Claim 4
According to the invention described in (1), the surface portion of the caliper main body corresponding to one string has a concave shape extending in the axial direction and has a shape along the drive shaft facing the surface portion, thereby preventing interference with the drive shaft. Can be reduced by reducing the gap between the drive shaft and the drive shaft, and the overall device can be made compact.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view schematically showing the electric motor and the caliper main body of FIG.

FIG. 3 is a sectional view schematically showing a second embodiment of the present invention.

FIG. 4 is a sectional view schematically showing a third embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing an example of a conventional electric disc brake.

FIG. 6 is a sectional view schematically showing the electric motor and the caliper main body of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric disc brake 7 Stator 72, 73 First and second stator subportions 72a, 73a Outer peripheral portion 8 Electric motor 9 Caliper body 9a, 9b Lower and upper outer peripheral surfaces

Claims (4)

[Claims] 1. A pair of brake pads disposed on both sides of a disk rotor, a piston provided to face one of the pair of brake pads, an electric motor in which a motor rotor is housed in a stator, and an electric motor. A caliper body to be stored, a claw part provided integrally with the caliper body and straddling the disk rotor and facing the other of the pair of brake pads, and converting the rotational motion of the motor rotor into a linear motion to form the piston. A motion conversion mechanism for moving forward and backward, the stator has a substantially cylindrical shape whose outer peripheral shape is non-circular when viewed from the axial direction of the motor rotor,
The caliper body is shaped along the stator. 2. The stator according to claim 1, wherein an outer peripheral shape of the motor rotor as viewed from the axial direction is a shape obtained by cutting two arcs including the two chords from a circle having two chords opposed to each other. The electric disc brake according to claim 1. 3. The electric disc brake according to claim 2, wherein one of the two strings has an outwardly concave shape, and the other has an outwardly convex shape. 4. The electric disk brake according to claim 1, wherein an outer peripheral shape of the stator viewed from an axial direction of the motor rotor is a shape obtained by cutting an arc including the chord from a circle having one chord. .