JP2010090994A - Electric brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake device attaining space saving of the brake device in a vehicle, and preferably facilitating mounting of an in-wheel motor. <P>SOLUTION: A block 206 is provided on an output shaft of an in-wheel motor 200 disposed within a wheel 204, and a brake shoe 220 is disposed between the inner circumferential surface of the wheel 204 and the block 206. The block 206 is rotated by drive of the in-wheel motor 200, whereby it rotative force is converted to a translational force in the radial direction of the brake shoe 220. When the brake shoe 220 is driven radially outwardly by the rotation of the block 206, a chip of the brake shoe 220 is pressed onto the wheel 104, whereby a braking force is given to the wheel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric brake device that obtains a braking force of a vehicle by electric energy.

2. Description of the Related Art Conventionally, as a device for braking a vehicle, a disc brake device including a disc rotor that rotates with a wheel and a caliper fixed to the vehicle body side is known (see, for example, Patent Document 1). The caliper is configured to include a pair of friction materials arranged with the disc rotor interposed therebetween. When the friction material is driven via hydraulic pressure or an electric mechanism, the friction material pinches the disk rotor to generate a braking force.
Japanese Patent Laid-Open No. 2004-360841

  However, since such a disc brake device has a structure in which a friction material is pressed perpendicularly to the disc rotor, a cylinder and a drive mechanism serving as a drive portion thereof increase in the vehicle width direction. When a so-called floating caliper is used, it is necessary to secure a gap for moving the cylinder and the like along with wear of the friction material, and there is room for improvement from the viewpoint of the installation space of the vehicle. Normally, since only one caliper is disposed on the circumference of the disk rotor, one caliper is designed to be large.

  On the other hand, in recent years, it has been proposed to employ an in-wheel motor system in which an in-wheel motor is installed corresponding to each drive wheel of a vehicle and its braking / driving force can be independently controlled. For example, there are those that transmit the output of the motor to the wheel via a reduction gear, and those that directly rotate the wheel by a motor without using a reduction gear by a direct drive system. According to such an in-wheel motor, regenerative braking force can be given to a drive wheel by carrying out regenerative control of a motor. However, since this regenerative braking alone may not provide sufficient braking force as a whole vehicle, a vehicle equipped with an in-wheel motor is usually equipped with a regular hydraulic brake using hydraulic pressure. . That is, smooth and safe braking can be performed by performing cooperative control using both the regenerative braking force and the hydraulic braking force of the motor. However, when such an in-wheel motor system is adopted, since the motor is arranged in the wheel, there is a problem that it becomes difficult to secure the installation space described above when the above-described disc brake device for hydraulic braking is installed. there were.

  The present invention has been made in view of such a situation, and provides a structure of a brake device that realizes space saving of a brake device in a vehicle, and preferably enables easy mounting of an in-wheel motor. Objective.

  In order to solve the above problems, an electric brake device according to an aspect of the present invention includes an in-wheel motor attached to a vehicle body and disposed in a wheel of a wheel, and an annular main body fixed to an output shaft of the in-wheel motor. A pressing member provided with a plurality of protrusions having an inclined surface whose height in the radial direction is changed at the tip of the outer peripheral surface of the main body and projecting radially outward, and an inner peripheral surface of the wheel It is attached to the vehicle body so as to be disposed between the pressure member and the pressing member, and one end side thereof is disposed opposite to the inner peripheral surface of the wheel, while the other end side has an inclined surface of the protrusion and a complementary facing surface. A brake shoe, a biasing member that biases the brake shoe in a direction away from the inner peripheral surface of the wheel, and an in-wheel motor that drives the brake shoe to control the rotation angle of the pressing member. Against changing the relative positions of the projections, thereby and a control unit for driving to displace between a braking position to be pressed against the brake shoe to the standby position and the wheel remote from the wheel.

  The in-wheel motor here may be one that generates only a braking force for the wheels, or one that generates a driving force. In addition, what is called a brake drum may be integrally fixed to the “wheel”, and in that case, the brake drum and the brake drum can be interpreted as a “wheel”.

  In this aspect, the pressing member is provided on the output shaft of the in-wheel motor disposed in the wheel, and the brake shoe is disposed between the inner peripheral surface of the wheel and the pressing member. When the pressing member rotates by driving the in-wheel motor, the rotational force is converted into the translational force in the radial direction of the brake shoe. When the brake shoe is driven radially outward by the rotation of the pressing member, the tip of the brake shoe is pressed against the wheel, so that a braking force is applied to the wheel.

  According to this aspect, since the mechanism for applying the braking force to the wheel is disposed in the radial direction of the wheel, the space occupied by the brake device in the width direction of the wheel can be reduced. If the in-wheel motor is used not only as a braking device but also as a driving device, space saving of the entire vehicle can be realized.

  According to the present invention, it is possible to realize a space saving of a brake device in a vehicle.

The best mode for carrying out the present invention will be described below with reference to the drawings.
[First Embodiment]
The vehicle of this embodiment is equipped with an in-wheel motor drive device on its drive wheel side (front wheel side in this embodiment), and a brake device using an in-wheel motor on the driven wheel side (rear wheel side in this embodiment). Is installed.

FIG. 1 is a schematic structural diagram showing the internal structure of the drive device according to the first embodiment.
An in-wheel motor 100 connected to a suspension (not shown) is disposed on each of the left and right front wheels of the vehicle. The in-wheel motor 100 constitutes a main part of the drive device, and is driven and controlled by an electronic control device (hereinafter referred to as “ECU”) (not shown) as a “control unit” mounted on the vehicle. That is, the ECU calculates a motor command value (torque command value) based on the driver's accelerator operation amount input from the accelerator pedal, and drives a drive circuit (not shown) connected to the battery to the in-wheel motor 100. The energization control is executed. In addition, a signal indicating the depression operation amount from the brake pedal and a signal indicating the steering angle and the like are input from the brake pedal to the ECU, and are reflected in the control of the in-wheel motor 100 as necessary. For example, when a brake pedal is operated by the driver and a deceleration request is input, the ECU causes the in-wheel motor 100 to function as a generator to perform regenerative braking, and charges the battery as necessary. Since such in-wheel motor control is known per se, detailed description thereof will be omitted.

  As illustrated, in the in-wheel motor 100, a wheel 104 on which a tire 102 is mounted is fixed to a hub wheel 108 by a hub nut 106. The hub wheel 108 is fixed to the output shaft 112 protruding from the motor housing 110 and rotates together with the output shaft 112. An electric motor 114 is accommodated in the motor housing 110. A gear housing 120 that houses a gear reducer 118 that reduces the rotation of the rotor 116 of the electric motor 114 is connected and fixed to the side surface of the motor housing 110 on the vehicle body side. The rotational output generated by the electric motor 114 is transmitted to the output shaft 112, the hub wheel 108, and the wheel 104 via the gear reducer 118. The wheel 104 is rotationally driven together with the tire 102 by the transmitted rotational force.

  An annular stator 130 is fixed to the inner wall surface of the motor housing 110, a rotor 116 is disposed inside the stator 130, and an output shaft 112 is rotatably housed inside the rotor 116. For example, the stator 130 is formed by laminating a plurality of plate-shaped electromagnetic steel plates, and an annular iron core 132a in which slots and teeth extending alternately in the central direction, that is, in the central direction of the rotor 116, and each tooth of the iron core 132a. And a three-phase magnetic field coil 132b wound around the part. By sequentially supplying current to the magnetic field coil 132b assembled in this manner at a predetermined timing, a rotating magnetic field can be generated in the stator 130 and the rotor 116 can be rotated.

  On the other hand, the rotor 116 disposed on the inner peripheral side of the stator 130 is formed with an insertion hole 116a through which the output shaft 112 is rotatably inserted in the central portion over the entire axial length. The output shaft 112 rotates independently of the rotor 116 by a plurality of bearings disposed in the insertion hole 116a. The rotor 116 includes a large-diameter portion that faces the stator 130 and a small-diameter portion that extends to the gear reducer 118 side. A plurality of permanent magnets 136 are arranged at equal intervals on the outer peripheral surface of the large-diameter portion, and the attracting action and the repulsive action are repeated via the permanent magnet 136 as the rotating magnetic field generated by the stator 130 moves. Is rotated in a desired direction at a desired speed.

  A small-diameter portion of the rotor 116 extends to the inside of the gear housing 120, and a rotor gear 140 that meshes with the first gear 138a of the gear reducer 118 is formed at the tip portion. Inside, a gear shaft 142 that supports the first gear 138a is supported by a plurality of bearings. A small-diameter second gear 138b is fixed to the gear shaft 142. Further, the second gear 138 b meshes with a large-diameter third gear 138 c that is fixed to the output shaft 112. Accordingly, the rotational force of the rotor 116 is transmitted to the output shaft 112 while increasing the torque while being decelerated to a predetermined speed by the gear reducer 118, and rotationally drives the wheel 104 and the tire 102.

  FIG. 2 is a schematic structural diagram schematically showing the internal structure of the braking apparatus according to the first embodiment. (A) shows the figure seen from the inner side of a wheel, (B) shows the notch sectional view seen from the side, (C) represents the partial enlarged view of (A).

  An in-wheel motor 200 connected to a suspension (not shown) is disposed on each of the left and right rear wheels. The in-wheel motor 200 is supported by the vehicle body and has substantially the same internal structure as the in-wheel motor 100 on the front wheel side, but a wheel 204 is loosely fitted to the tip of the output shaft via a bearing device 202. That is, although the output shaft of the in-wheel motor 200 supports the wheel 204, the rotational force is not transmitted to the wheel 204. Accordingly, the driven wheel (rear wheel) is rotationally driven according to the operation of the drive wheel (front wheel) except during braking. The details of the internal structure of the in-wheel motor 200 will be omitted.

  A gear is integrally fixed at the center of the output shaft of the in-wheel motor 200, and an annular block 206 (corresponding to a “pressing member”) is fitted and fixed so as to be concentrically inserted into the gear. . Three protrusions 210, 212, and 214 that protrude outward in the radial direction are provided on the outer peripheral surface of the block 206. In the present embodiment, the protrusion 212 is provided at a position shifted by 30 degrees in the rotation direction with respect to the protrusion 210, and the protrusion 214 is provided at a position shifted by 180 degrees. These protrusions rotate in the same direction by the rotation of the block 206, that is, the rotation of the output shaft.

  Further, an annular support portion 208 is provided concentrically outside the block 206 (not shown in FIG. 5B). The support portion 208 has a predetermined width and thickness, and is fixed to the vehicle body via an arm (not shown). Brake shoes 220, 222, and 224 are supported in the vicinity of positions facing the protrusions 210, 212, and 214 of the support portion 208 so as to be displaceable in the radial direction. That is, an insertion hole through which each brake shoe can be inserted is provided in the vicinity of the position of the support portion 208 facing each projection, and a spring receiving portion 226 is provided so as to surround the insertion hole. A flange portion is provided at the center in the longitudinal direction of each brake shoe, and a spring 228 (corresponding to an “urging member”) that biases each brake shoe toward the block 206 side between the flange portion and the spring receiving portion 226. Is included. For this reason, each brake shoe is displaced to the block 206 side when no radial outward force is applied from the block 206 side, but the flange portion is locked to the outer peripheral surface of the support portion 208. Therefore, the amount of displacement is regulated.

  A lining 230 (corresponding to “friction material”) is fixed to the surface of each brake shoe facing the inner periphery of the wheel 204. When the lining 230 is pressed against the inner peripheral surface of the wheel 204 as shown in the figure, a braking force due to a frictional force is applied to the wheel. That is, as shown in FIG. 6C, the tip surface of the protrusion 210 is an inclined surface that becomes shorter as it goes in the direction of rotation of a thin arrow (referred to as “forward rotation” for convenience), while the brake facing this The end surface of the shoe 220 (the end surface opposite to the lining 230) is a complementary inclined surface that is elongated in the same direction. At the time of non-braking, as shown in the figure, the axis of the brake shoe 220 and the axis of the protrusion 210 are displaced in the rotational direction, and the brake shoe 220 is held at the standby position close to the block 206 by the urging force of the spring 228. . When the brake shoe 220 is in this standby position, the lining 230 is completely separated from the inner peripheral surface of the wheel 204, so that no braking force is applied to the wheel by this braking device.

  On the other hand, during braking, the ECU energizes the in-wheel motor 200 to rotate the block 206 forward. As a result, the brake shoe 220 is driven toward the wheel 204 (in the direction of the thick arrow) against the urging force of the spring 228. The block 206 is held at a braking position rotated at an angle where the axis of the brake shoe 220 and the axis of the protrusion 210 coincide with each other as shown in FIG. 5A, and the lining 230 is pressed against the inner peripheral surface of the wheel 204. . At this time, the brake shoes 222 and 224 are similarly pressed with the lining 230 against the inner peripheral surface of the wheel 204, and the wheel 204 receives a braking force due to friction at three locations. When the target braking force is obtained in this way, the ECU executes the control to reversely rotate the in-wheel motor 200 and return the block 206 to the original position. As a result, the pressing force by the protrusion is released, and each brake shoe returns to the standby position by the urging force of the spring 228.

  As described above, in the present embodiment, since the plurality of linings 230 are simultaneously pressed against the wheel 204 using the rotation of the in-wheel motor 200, one friction material can be made thin and small. Become. Further, there is no need to provide a cylinder, a piston, etc., and a space inside the vehicle can be secured.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the present embodiment, the configuration of the braking device is different from that of the first embodiment. In the present embodiment, components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  FIG. 3 is a schematic structural diagram schematically showing the internal structure of the braking system according to the second embodiment. (A) represents a partially cutaway cross-sectional view and corresponds to FIG. (B) is a perspective view showing the structure of the principal part.

  In the present embodiment, a brake disc 350 is fixed concentrically with respect to the wheel 204. The brake disc 350 has a stepped disk shape and is assembled so that the bearing device 202 is fitted. That is, the wheel 204 is loosely fitted to the tip of the output shaft of the in-wheel motor 200 via the bearing device 202 and the brake disc 350.

  A gear is integrally fixed to the output shaft of the in-wheel motor 200, and a disk-like block 306 is fitted and fixed so as to be concentrically inserted into the gear. In the vicinity of the outer peripheral portion of the block 306 facing the brake disc 350, as shown in FIG. 3B, three protrusions 310 protruding toward the brake disc 350 are provided at predetermined intervals in the circumferential direction. ing. These protrusions are rotated in the same direction by the rotation of the block 306, that is, the rotation of the output shaft.

  In addition, brake shoes 320 are respectively disposed at positions facing the protrusions 310 between the block 306 and the brake disc 350 (only one is shown in the figure for convenience). The brake shoe 320 is supported by a support portion (not shown) fixed to the vehicle body so as to be displaceable in a direction approaching or separating from the brake disc 350. The support portion is provided with a spring (not shown) that urges the brake shoe 320 in a direction away from the brake disc 350. A structure similar to that shown in FIG. 2 can be applied as the structure of the spring and the spring receiver that receives the spring, but the illustration thereof is omitted. Each brake shoe is displaced to the block 306 side when no force is applied from the block 306 side to the brake disc 350 side.

  A lining 330 is fixed to the surface of each brake shoe facing the brake disc 350. When the lining 330 is pressed against the brake disc 350, a braking force by a frictional force is applied to the wheel. That is, as shown in FIG. 5B, the tip surface of the projection 310 is an inclined surface that becomes shorter as it goes in the direction of rotation of a thin arrow (referred to as “forward rotation” for convenience), while the brake facing this The end surface of the shoe 320 (the end surface opposite to the lining 330) is a complementary inclined surface that is elongated in the same direction. During non-braking, the brake shoe 320 is held at the standby position close to the block 306 by the biasing force of the spring. When the brake shoe 320 is in this standby position, the lining 330 is completely separated from the brake disc 350, so that no braking force is applied to the wheels by this braking device.

  On the other hand, during braking, the ECU energizes the in-wheel motor 200 to rotate the block 306 forward. As a result, the brake shoe 320 is driven toward the brake disc 350 (in the direction of the thick arrow) against the urging force of the spring. As a result, the lining 330 is pressed against the brake disc 350, and the brake disc 350 receives a braking force due to friction at three locations. When the target braking force is obtained in this way, the ECU performs a control to reversely rotate the in-wheel motor 200 and return the block 306 to the original position. As a result, the pressing force by the protrusion is released, and each brake shoe returns to the standby position by the biasing force of the spring.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added to the embodiments based on the knowledge of those skilled in the art, and such modifications have been added. Embodiments may also be included within the scope of the present invention.

FIG. 4 is a schematic structural diagram schematically showing the internal structure of a braking system according to a modification of the second embodiment. This figure corresponds to FIG.
In the second embodiment, as shown in FIG. 3, the braking force is obtained by pressing the lining 330 against one surface of the brake disc 350. In the modified example, as shown in FIG. 4, the braking force may be obtained by pressing the lining 330 from both sides of the brake disk 360.

  That is, in the present modification, the brake disc 360 is fixed to the middle portion of the wheel 204 in the axial direction. The brake disc 360 includes an annular portion provided so as to protrude from the inner peripheral surface of the wheel 204 inward by a predetermined amount. On the other hand, a pair of blocks 306 are fitted and fixed to the output shaft of the in-wheel motor 200 via a gear. The pair of blocks 306 are opposed to each other with a predetermined interval so as to sandwich the brake disk 360. Projections 310 similar to those shown in FIG. 3 are provided on the surface of each block 306 facing the brake disc 360, and brake shoes 320 are disposed between the projections 310 and the brake disc 360, respectively. Has been. As in the second embodiment, the brake shoe 320 is supported by a support portion (not shown) fixed to the vehicle body so as to be displaceable in a direction approaching or separating from the brake disc 350.

  At the time of non-braking, each brake shoe 320 is held at a standby position close to the block 306 and the lining 330 is completely separated from the brake disc 360, so that braking force is applied to the wheels by this braking device. There is no. On the other hand, the brake shoe 320 is driven to the brake disc 350 side by rotating the block 306 during braking, and the lining 330 is pressed against the brake disc 350. As a result, the brake disc 360 receives a braking force due to friction at six locations including both sides. In this way, by adopting a configuration in which the brake disc 360 is clamped from both sides, a greater braking force can be exerted.

  In each embodiment, the in-wheel motor 200 has been described as having the same structure as the in-wheel motor 100. However, for example, a stepping motor may be applied, and the in-wheel motor 200 may be configured as a motor having a different structure.

  In each embodiment, a driving device is provided on the front wheel side, and a braking device is provided on the rear wheel side. That is, in braking control, regenerative braking is performed on the front wheel side, while braking control by friction is executed on the rear wheel side. In a modified example, the driving device and the braking device may be integrally formed on the driving wheel side. Specifically, the in-wheel motor 100 shown in FIG. 1 may be configured to also serve as the in-wheel motor 200 shown in FIGS. For example, the output shaft for driving and the output shaft for braking may be switched by a clutch or a gear mechanism.

  In each embodiment, as a braking device including the in-wheel motor 200, a device that operates based on an operation of a brake pedal is shown. In the modification, the braking device including the in-wheel motor 200 may be configured as a so-called parking brake device that locks the braking state.

It is a schematic structure figure showing the internal structure of the drive concerning a 1st embodiment. It is a schematic structure figure showing simply the internal structure of the brake equipment concerning a 1st embodiment. It is a schematic structure figure showing simply the internal structure of the brake equipment concerning a 2nd embodiment. It is a schematic structure figure showing simply the internal structure of the brake equipment concerning the modification of a 2nd embodiment.

Explanation of symbols

  100 in-wheel motor, 102 tire, 104 wheel, 112 output shaft, 200 in-wheel motor, 202 bearing device, 204 wheel, 206 block, 208 support part, 210 protrusion, 212 protrusion, 214 protrusion, 220 brake shoe, 222 brake shoe , 228 spring, 230 lining, 306 block, 310 protrusion, 320 brake shoe, 330 lining, 350 brake disc, 360 brake disc.

Claims (1)

An in-wheel motor attached to the vehicle body and arranged in the wheel of the wheel;
A plurality of annular main bodies fixed to the output shaft of the in-wheel motor, the outer peripheral surfaces of the main bodies projecting outward in the radial direction, and at the tips thereof, a plurality of inclined surfaces with varying radial heights; A pressing member provided with a protrusion;
It is attached to the vehicle body so as to be disposed between the inner peripheral surface of the wheel and the pressing member, and one end side thereof is disposed opposite to the inner peripheral surface of the wheel, while the protrusion is formed on the other end side. A brake shoe having an opposing surface complementary to the inclined surface;
A biasing member that biases the brake shoe in a direction away from the inner peripheral surface of the wheel;
By controlling the rotation angle of the pressing member by driving the in-wheel motor, the relative position of the protrusion with respect to the brake shoe is changed, and thereby the brake shoe is moved to the standby position separated from the wheel and the wheel. A controller that drives to displace between the braking position to be pressed; and
An electric brake device comprising:

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