JP2019108916A - Brake device - Google Patents

Abstract

To provide a brake device which can obtain a stable brake force by improving the detection accuracy of brake torque.SOLUTION: A pressing plate member 67 makes a rotating plate 66a and a fixed plate 66b friction-engaged with each other by being pressed in an axial line direction of a rotating shaft L1 of the rotating plate. Return springs 74, 75 impart pressing forces which withstand a pressing force of the pressing plate member 67 to the pressing plate member 67. A movable ring 71 supports the fixed plate 66b so as to permit the movement of the rotating shaft L1 in the axial line direction, and to prohibit rotation exceeding allowance which is set in a peripheral direction with an axial line as a center. A torque receiving member 68 is permitted in movement in the axial line direction, and prohibited in rotation in the peripheral direction with the axial line as a center, and receives torque transmitted from the fixed plate 66b. A conversion mechanism 76 converts the torque received by the torque receiving member 68 to the pressing force of the pressing plate member 67. A detector 82 detects a reaction force with respect to the pressing force.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a brake device that generates an engagement force between a rotating member and a fixing member.

  Conventionally, a motor with an electromagnetic brake integrally provided with a drive motor and a braking motor is known (see, for example, Patent Document 1). This type of device includes a drive motor, an electromagnetic brake, a thrust generating mechanism, and a braking motor. The drive motor rotates a motor shaft integrally attached to the rotor. The electromagnetic brake changes the electromagnetic attraction force by increasing or decreasing the current supplied to the braking solenoid according to the braking request generated by the driver's brake pedal operation to move the brake rotor to the brake stator to brake the motor shaft. Do.

Unexamined-Japanese-Patent No. 2017-112673 JP, 2014-209017, A

  However, the coefficient of friction of the friction material between the brake stator and the brake rotor changes due to wear due to contact. In general, in a hydraulic friction brake device, an oil pressure sensor is provided on a wheel cylinder, and a brake torque is estimated based on oil pressure information obtained from the oil pressure sensor. Therefore, as described above, there is a possibility that the determination of the brake torque may change due to the change of the friction coefficient of the friction material. Thus, it is preferable to control the pressing force that causes the brake stator and the brake rotor to be frictionally engaged according to the braking request, rather than controlling the moving amount of the brake rotor according to the braking request.

  For example, Patent Document 2 describes a driving force transmission device including a strain sensor that detects a reaction force to the thrust of the cam mechanism so that the thrust of the cam mechanism that presses the clutch can be precisely adjusted. ing. The drive device controls the current supplied to the motor based on the information obtained from the strain sensor. The strain sensor is attached to one side of the peripheral edge of the ring-shaped diaphragm. A plurality of coiled spring members to which a reaction force is transmitted are attached to the other surface of the diaphragm in the circumferential direction of the dial. The spring member transmits an elastic force generated by being elastically deformed by a reaction force transmitted from the cam mechanism to the diaphragm, and mitigates an impact on the strain sensor from the cam mechanism. The strain sensor detects the amount of deformation of the outer peripheral edge of the diaphragm through the spring member. However, the spring member may not uniformly transmit the reaction force on the diaphragm surface overlapping the surface on which the strain sensor is disposed. Therefore, there is a possibility that a distortion sensor can not detect a precise reaction force by using a spring member. In the brake device, since it is necessary to control the braking force with high accuracy in accordance with the braking request, there is room for improvement in means for accurately controlling the engagement force for generating the braking force.

  The present invention has been made in view of the above technical problems, and an object thereof is to provide a brake device capable of obtaining a stable braking force by improving the detection accuracy of the brake torque.

  In order to achieve the above object, according to the present invention, there is provided a rotating member which is rotated by a torque transmitted from a driving power source, a fixed member disposed opposite to the rotating member, and an axis of a rotating shaft of the rotating member. A brake device comprising: a pressing member generating an engagement force between the rotating member and the fixing member by being moved in a direction; and an elastic member applying an elastic force against the engagement force to the pressing member At least a play along the rotation direction of the rotating member is given to the fixed member to transmit torque transmitted from the rotating member to the fixed member, and torque transmitted from the torque transmitting member A conversion mechanism that converts the thrust in the axial direction and applies the converted thrust to the engagement force, and a reaction force generated by the engagement force is transmitted from the rotating member. In which torque is or torque thereof, characterized in that it comprises a detecting section for determining axial force converted the axial direction.

  According to the present invention, the torque transmitting member for transmitting the torque transmitted from the rotating member to the fixed member, and the torque transmitted from the torque transmitting member are converted into axial thrust, and the converted thrust is applied to the engagement force. And a conversion mechanism. Therefore, the reaction force to the engagement force is accurately transmitted to the detection unit. As a result, the detection unit can accurately determine the torque transmitted from the rotating member or the axial force in the axial direction to which the torque is converted. Therefore, the detection accuracy of the brake torque is improved to achieve stable control. Power can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the drive device which employ | adopted an example of the brake device concerning embodiment of this invention. It is an expanded sectional view which shows the principal part of the brake device shown in FIG. It is sectional drawing which shows an example of the conversion mechanism shown in FIG. It is sectional drawing which shows another embodiment of an engagement force provision mechanism. It is sectional drawing which shows other embodiment which changed the position of the detector. FIG. 10 is a cross-sectional view showing another embodiment in which the position of the detector is changed.

  FIG. 1 is a cross-sectional view showing a drive device adopting an example of a brake device according to an embodiment of the present invention. As shown in FIG. 1, the drive device 10 is mounted on a vehicle, and the first drive wheel 11 disposed on the right side in the vehicle width direction, the second drive wheel 12 disposed on the left side, and the first drive wheel 11, the second motor 14 for the second drive wheel 12, the first power transmission mechanism 15 for the first drive wheel 11, the second power transmission mechanism 16 for the second drive wheel 12, a differential A mechanism 17, a first brake mechanism 18 for the first drive wheel 11, and a second brake mechanism 19 for the second drive wheel 12 are provided. The right and left sides in the vehicle width direction shown in FIG. 1 are, for example, the left and right directions when the vehicle is viewed from the back (rear) in FIG. 1, and the vehicle is viewed from the front (front) In the case of FIG. 1, the left-right direction is reversed.

  In addition, the first drive wheel 11, the first motor 13, the first power transmission mechanism 15, the first brake mechanism 18, the second drive wheel 12, the second motor 14, the second power transmission mechanism 16, and the second brake mechanism 19. Are disposed approximately symmetrically on both sides of the center in the vehicle width direction. Therefore, in the following description, the first drive wheel 11, the first motor 13, the first power transmission mechanism 15, and the first brake mechanism 18 disposed on the right side in the vehicle width direction will be described. The mechanism disposed on the left side has the same or similar configuration as the mechanism disposed on the right side, and therefore, the same members and the same numbers and the suffix “L” are given to the same members, and the detailed description here is omitted. The first motor 13 and the second motor 14 are an example of a driving force source in the embodiment of the present invention.

  The first motor 13 is a motor that generates a driving force for traveling to be transmitted to the first drive wheel 11, and is a motor having a power generation function, and is configured by a synchronous motor of a permanent magnet type as one example. Specifically, an annular stator 22 is attached to the inside of a drum-shaped motor housing 21, and a rotor 23 is provided inside the stator 22. The rotor 23 is integrally connected to the output shaft 24, and the output shaft 24 rotates about the rotation axis L 1 by the drive of the first motor 13. The output shaft 24 is rotatably supported via bearings 27, 28 provided on partitions 25, 26 on both sides of the motor housing 21.

  The first power transmission mechanism 15 includes an output gear 30, a countershaft 31, a counter driven gear 32, a pinion gear 33, and a final reduction gear 34, and transmits the driving force output from the first motor 13 to the first drive wheel 11. .

  The output gear 30 is connected to the left end of the output shaft 24 in the vehicle width direction. The counter shaft 31 is disposed in parallel with the output shaft 24. Connected to the counter shaft 31 is a two-step gear in which a pinion gear 33 and a counter driven gear 32 are integrally mounted coaxially. The counter driven gear 32 meshes with the output gear 30. The pinion gear 33 is smaller in diameter than the counter driven gear 32. A final reduction gear 34 larger in diameter than the pinion gear 33 meshes with the pinion gear 33.

  The final reduction gear 34 is connected to a countershaft 35 disposed parallel to the countershaft 31. The countershaft 35 is connected to one end of the drive shaft 36 by spline connection. The drive shaft 36 has a connection mechanism (not shown) such as a constant velocity joint for changing the rotational axes at both ends in the height direction of the vehicle, similarly to the drive shaft known in the prior art. The other end of the drive shaft 36 is connected to the first drive wheel 11. The drive shaft 36 is disposed coaxially with the countershaft 35.

  The first power transmission mechanism 15 in the present embodiment increases the torque of the output gear 30 according to the gear ratio between the output gear 30 and the counter driven gear 32 and the gear ratio between the pinion gear 33 and the final reduction gear 34 to drive shaft It may be comprised by the reduction mechanism transmitted to 36.

  The first power transmission mechanism 15 is housed inside the center housing 37. The above-described motor housing 21 is attached to the center housing 37 on the right side in the vehicle width direction. Further, the countershaft 31 and the countershaft 35 are rotatably supported via a bearing by a partition attached to the center housing 37.

  Further, the output shaft 24 of the first motor 13 is coaxially disposed with the output shaft 24L of the second motor 14, and the drive shaft 36 of the first power transmission mechanism 15 is a drive of the second power transmission mechanism 16. It is disposed coaxially with the shaft 36L. Further, the counter shaft 31 of the first power transmission mechanism 15 is coaxial with the counter shaft 31 L of the second power transmission mechanism 16, and the countershaft 35 of the first power transmission mechanism 15 is an auxiliary of the second power transmission mechanism 16. It is disposed coaxially with the shaft 35L.

  The differential mechanism 17 is a mechanism capable of making different torques transmitted to the output shaft 24 of the first power transmission mechanism 15 and the output shaft 24L of the second power transmission mechanism 16 different from each other. The differential mechanism 17 includes a connecting shaft 39, a flange portion 40, a fastening plate 41, an extension shaft 42, an accommodating portion 43, a snap ring 44, a yoke 45, a pressing plate 46, a cylindrical portion 47, a coil spring 48, and a coil 49. It is configured.

  The connecting shaft 39 is connected to one end of the output shaft 24 by spline connection. The flange portion 40 is formed on the connecting shaft 39 coaxially with the rotation axis L1. Spline teeth 40 a are formed on the outer peripheral surface of the flange portion 40. Further, an annular fastening plate 41 is disposed concentrically with the flange portion 40. Spline teeth 41 a are formed on the inner peripheral surface of the fastening plate 41. The flange portion 40 and the fastening plate 41 are movable in the axial direction of the rotation axis L1 by the engagement of the spline teeth 40a and 41a.

  An extension shaft 42 is connected to one end of the output shaft 24L of the second motor 14 by spline connection. A housing portion 43 is integrally formed on the extension shaft 42 with the connecting shaft 39. The housing portion 43 has a recess 38 formed in a substantially C-shaped cross section with the open side facing the output shaft 24. The fastening plate 41 described above is rotatably attached to the recess 38. Further, on the open side of the recess 38, a snap ring 44 is attached for preventing the fastening plate 41 from coming out of the recess 38.

  An annular yoke 45 is integrally attached to the recess 38, and an annular pressing plate 46 is disposed between the yoke 45 and the fastening plate 41. The pressure plate 46 and the recess 38 are splined. That is, the pressing plate 46 can rotate integrally with the recess 38 and move in the axial direction in the recess 38.

  The pressing plate 46 is made of a magnetic material, and a cylindrical portion 47 extending on the bottom surface side of the recess 38 in the axial direction is formed in the inner diameter portion thereof. The coil spring 48 is disposed on the outer periphery of the cylindrical portion 47 so as to be compressed between the bottom surface of the recess 38 and the pressing plate 46, and biases the pressing plate 46 toward the fastening plate 41 in the axial direction. Furthermore, a coil 49 is disposed on the outer periphery of the housing portion 43.

  The coil 49 generates a magnetic force against the elastic force of the coil spring 48 by being energized. The magnetic force acts on the pressure plate 46 so as to be axially separated from the fastening plate 41. On the other hand, when the coil 49 is not energized, the pressing plate 46 is pressed against the fastening plate 41 by the elastic force of the coil spring 48. A frictional force corresponding to the elastic force of the coil spring 48 is generated between the pressing plate 46 and the fastening plate 41. The friction force is a degree to which the pressing plate 46 and the fastening plate 41 do not rotate relative to each other due to the torque difference acting on the left and right output shafts 24 when traveling straight ahead or traveling on a traveling path having a relatively large turning radius. It is defined in The differential mechanism 17 constitutes a friction clutch in which the coil 49 is an electromagnetic actuator.

  The first brake mechanism 18 includes a service brake mechanism 51 and a parking brake mechanism 52. The parking brake mechanism 52 is operated at the time of parking or stopping to hold the braking force. The service brake mechanism 51 includes a hydraulic brake mechanism 53.

  The hydraulic brake mechanism 53 includes a master cylinder unit 55, a power hydraulic pressure source 56, a hydraulic pressure actuator 57, and a hydraulic pressure circuit 58 connecting them.

  The power hydraulic pressure source 56 includes an accumulator, a pressure sensor, a motor, and a pump (all not shown) and the like, and brake fluid to be applied to the master cylinder unit 55 by accumulating brake hydraulic pressure in a predetermined pressure range in the accumulator. Generate pressure. The brake fluid pressure (accumulator pressure) stored in the accumulator is detected by a pressure sensor so that it falls within a predetermined pressure range. If the accumulator pressure is low, suction and discharge operation of the brake fluid by the pump is performed by driving the motor. Let it go.

  Master cylinder unit 55 may be, for example, a master cylinder with a hydraulic pressure booster. The hydraulic booster-equipped master cylinder includes a hydraulic pressure booster 60, a master cylinder 61, a regulator 62, and a reservoir 63. By depressing the brake pedal 64, the brake fluid of the master cylinder 61 is pressurized. The hydraulic pressure booster 60 is connected to the brake pedal 64, amplifies the pedal depression force applied to the brake pedal 64, and transmits it to the master cylinder 61. By supplying the brake fluid from the power hydraulic pressure source 56 to the hydraulic pressure booster 60 via the regulator 62, the depression force (pedal depression force) of the brake pedal 64 is amplified. Master cylinder 61 generates a master cylinder pressure having a predetermined boost ratio with respect to the pedal depression force.

  Master cylinder 61 communicates with reservoir 63 when the depression on brake pedal 64 is released. On the other hand, the regulator 62 is in communication with both the reservoir 63 and the accumulator of the power hydraulic pressure source 56, and uses the reservoir 63 as a low pressure source and an accumulator as a high pressure source. Pressure).

  The hydraulic actuator 57 appropriately adjusts the hydraulic pressure of the brake fluid supplied from the power hydraulic pressure source 56 or the master cylinder unit 55 and transmits it to the wheel cylinder. The wheel cylinders are respectively provided in service brake mechanisms 51 and 51L described later in detail. Although the hydraulic brake mechanism 53 is used in the present embodiment, the present invention is not limited to this, and for example, a pneumatic brake mechanism may be used. The hydraulic brake mechanism 53 is an example of an engagement force application mechanism.

  FIG. 2 is an enlarged sectional view showing an essential part of the drive device shown in FIG. As shown in FIG. 2, the service brake mechanism 51 includes a friction plate 66, a pressing plate member 67, a torque receiving member 68, a conversion mechanism 76 (a first conversion mechanism 76-1, a second conversion mechanism 76-2), and a screw shaft. It has 69 and so on.

  The friction plate 66 has a surface formed of a friction material, and has an annular rotating plate 66a (66a-1, 66a-2) and an annular fixed plate 66b (66b-1, 66b-2, 66b-3). It consists of In this embodiment, the rotating plate 66a comprises a first rotating plate 66a-1 and a second rotating plate 66a-2, and the fixing plate 66b comprises a first fixing plate 66b-1 and a second fixing plate 66b-2. , And the third fixed plate 66b-3. The rotating plate 66a is disposed one by one between the three fixed plates 66b. The number and arrangement order of the friction plates 66 are not limited to the embodiment described above.

  The rotating plate 66 a is fixed to the boss member 70. The boss member 70 is connected to the output shaft 24 by spline connection and rotates together with the output shaft 24. The fixed plate 66 b is supported by the movable ring 71 by spline connection. That is, the movable ring 71 has a connecting portion 71a which connects the fixed plate 66b by spline connection. The coupling portion 71a is splined, and movably supports the fixed plate 66b in the axial direction of the rotation axis L1.

  A rotary plate 66a and a fixed plate 66b are alternately arranged in the axial direction, thereby forming a multi-plate friction plate. In this embodiment, the flange-like pressing plate 67a provided on the pressing plate member 67 is pressed toward the left in the vehicle width direction, so that a frictional engagement force is generated between the rotating plate 66a and the fixed plate 66b. The braking force is generated on the output shaft 24 by the engagement force. Alternatively, the rotation plate 66a may be moved toward the fixed plate 66b to generate an engagement force by friction. Alternatively, the rotation plate 66a may be sandwiched between the pair of fixing plates 66b to generate an engagement force by friction. The rotating plate 66a is an example of the rotating member in the embodiment of the present invention. The fixing plate 66b is an example of the fixing member in the embodiment of the present invention.

  An annular fixed ring 72 is disposed on the outer periphery of the movable ring 71. The fixing ring 72 has an outer surface fixed to the motor housing 21. The fixed ring 72 is formed with a concave portion 72a having a substantially C-shaped cross section with the open side directed to the right in the vehicle width direction. The recess 72a accommodates the friction plate 66 and the movable ring 71 described above, and has an opening 72b through which the output shaft 24 is inserted and a receiving surface 72c that receives the pressing force transmitted from the pressing plate 67a. The opening 72b is formed at the center of the bottom surface 72d of the recess 72a, and the receiving surface 72c is provided on the bottom surface 72d excluding the opening 72b.

  An inner peripheral groove 92 and an outer peripheral groove 93 each having a semicircular cross section are provided at the joint between the outer peripheral portion of the movable ring 71 and the side surface 72 e of the recess 72 a (inner peripheral portion of the fixed ring 72). The inner circumferential groove 92 and the outer circumferential groove 93 overlap to form a rectilinear groove 94 having a substantially circular cross section and extending in parallel to the axial direction. A plurality of rectilinear grooves 94 are provided in the circumferential direction about the axis. Each straight advance groove 94 is provided with a guide pin 73 which is an example of a rolling element. The guide pin 73 is a pin whose circumferential surface is parallel to the axial direction. The rectilinear groove 94 has a slight play in the circumferential direction about the axis of the rotation axis L1 with respect to the guide pin 73, and stops the rotation of the movable ring 71 in the circumferential direction beyond the play, and a fixed ring 72 allows the movable ring 71 to move in the axial direction of the rotation axis L1. That is, the rectilinear grooves 94 allow the torque transmitted from the rotating plate 66a to pass through the first fixed plate 66b-1 by allowing rotation of the fixed plate 66b and the movable ring 71 as described above. To communicate. The guide pin 73 and the rectilinear groove 94 are an example of the torque transmission member in the embodiment of the present invention.

  In the present embodiment, the guide pin 73 is a parallel pin having a circular cross section. However, the guide pin 73 may be a parallel pin having a rectangular cross section, for example. In this case, the inner circumferential groove 92 and the outer circumferential groove 93 may have a cross-sectional shape that fits into the cross-sectional shape of the guide pin 73. Also, instead of the guide pin 73, a sphere may be used. A plurality of spheres may be used for each of the rectilinear grooves 94.

  A pair of return springs 74 and 75 are disposed on both sides of the guide pin 73 in the axial direction. The pair of return springs 74 and 75 abut on the guide pin 73 in the axial direction. One return spring 74 is in contact with the bottom surface 72 d of the fixed ring 72 on the opposite side of the guide pin 73 in the axial direction. The other return spring 75 is in contact with a pressing plate 67a on the opposite side to the guide pin 73 in the axial direction. The diameter of the return springs 74 and 75 may be the same as or smaller than the diameter of the guide pin 73. The return springs 74, 75 may be of the same size and elasticity.

  The pair of return springs 74 and 75 apply an elastic force to the pressing plate 67a against the pressure of the pressing plate 67a. As a result, the pair of return springs 74, 75 functions to close back the path that transmits the pressing force toward the pressing plate 67a. Instead of the return springs 74 and 75, an elastic member elastically deformable in the axial direction may be used. The return springs 74 and 75 are an example of the elastic member in the embodiment of the present invention.

  The pressing plate member 67 has a pressing plate 67a and a cylinder portion 67b, and is disposed inside the brake housing 79 in a state where rotation in the circumferential direction about the axis of the rotational axis L1 and movement in the axial direction are permitted. It has been incorporated. The pressing plate 67 a is formed in a flange shape, and is disposed at a position facing the receiving surface 72 c with the friction plate 66 interposed therebetween. The pressing plate 67a presses the first fixed plate 66b-1 and the return spring 75 toward the left in the vehicle width direction as described above. The cylinder portion 67 b is a cylindrical portion formed in a substantially C-shaped cross section with the open side directed to the right in the vehicle width direction. The pressing plate 67a is formed on the outer peripheral portion of the cylinder portion 67b and to the left in the vehicle width direction.

  Torque receiving member 68 is supported on the outer peripheral portion of cylinder portion 67b and inside brake housing 79 so that rotation in the circumferential direction about the axis of rotation axis L1 is stopped and axial movement is possible. ing. The torque receiving member 68 has a torque receiving plate 68a, a receiving pressure piston portion 68b, and a nut portion 68c. The torque receiving member 68 may be attached to the pressing plate member 67 so as to be movable relative to the axial direction of the rotation axis L1.

  The brake housing 79 is fixed to the motor housing 21. The rotation stop of the torque receiving member 68 may be performed by a spline joint 68 h provided between the torque receiving member 68 and the inner wall of the brake housing 79.

  The torque receiving plate 68a is disposed on the right side in the vehicle width direction with respect to the pressing plate 67a and opposite to the pressing plate 67a. The first conversion mechanism 76-1 is provided between the torque receiving plate 68a and the pressing plate 67a. The first conversion mechanism 76-1 receives the torque transmitted from the rotating plate 66a to convert the torque into a pressing force toward the bottom surface 72d of the fixed ring 72, that is, a thrust along the axial direction of the rotation axis L1. And boost the thrust. The thrust converted into thrust along the axial direction and boosted is applied to the pressing plate 67a.

  That is, the movable ring 71 has play in the circumferential direction centering on the axis of the rotation axis L1 with the guide pin 73. Further, the movement of the torque receiving member 68 in the axial direction is stopped by a feed screw mechanism described later in detail. Therefore, when the torque transmitted from the rotating plate 66a is transmitted to the pressing plate member 67 via the first fixed plate 66b-1, the conversion mechanism 76 transmits the torque transmitted to the pressing plate member 67 in the vehicle width direction. The pressure is converted to the leftward pressure and the pressure is increased.

  The second conversion mechanism 76-2 is provided between the third fixed plate 66 b-3 and the bottom surface 72 d of the fixed ring 72. The second conversion mechanism 90-2 uses the torque transmitted to the third fixed plate 66 b-3 as the pressing force (thrust in the direction opposite to the thrust generated by the first conversion mechanism 76-1) toward the pressing plate 67 a Convert and boost its thrust. The thrust is applied to the third fixed plate 66b-3. The thrust generated by the first conversion mechanism 76-1 and the second conversion mechanism 76-2 is a force for sandwiching the rotating plate 66a between the pressing plate 67a and the third fixed plate 66b-3. The second conversion mechanism 76-2 may be omitted. Also, a thrust bearing may be used instead of the second conversion mechanism 76-2.

  The pressure receiving piston portion 68b has a cylindrical portion 68d sliding on the outer periphery of the cylinder portion 67b and a partition wall 68e sealing the inside of the cylinder portion 67b, and the wheel cylinder 77 is interposed between the cylinder portion 67b and the partition wall 68e. Form. Further, the torque receiving member 68 including the receiving pressure piston portion 68b is prevented from moving in the axial direction of the rotation axis L1 by screwing a nut portion 68c described later in detail with the screw shaft 69. The nut portion 68c, the spline joint portion 68h, and the screw shaft 69 constitute a feed screw mechanism which converts the rotational motion transmitted from the rotor shaft 80a into a linear motion and transmits the linear motion to the torque receiving member 68.

  An oil passage 68 f is formed in the torque receiving member 68. An oil passage 78 communicating with the oil passage 68f is formed in the brake housing 79. The torque receiving member 68 is moved in the axial direction of the rotation axis L1 by the feed screw mechanism, so the oil passage 68f is formed larger in diameter than the oil passage 78 in consideration of that amount.

  Pressure oil is supplied to the wheel cylinder 77 from the hydraulic actuator 57 of the hydraulic brake mechanism 53 via the oil passage 78 and the oil passage 68f. When pressure oil is supplied to the wheel cylinder 77 through the oil passages 68f and 78, the cylinder portion 67b is pressed leftward in the vehicle width direction because the partition wall 68e acts as a fixed wall. As a result, the pressing plate 67 a is pressed to the left in the vehicle width direction with respect to the torque receiving member 68 to generate an engagement force on the friction plate 66.

  The pressing plate member 67 generates an engagement force between the rotating plate 66a and the fixed plate 66b from the position where the pressing plate member 67 comes in contact with the torque receiving member 68 via the conversion mechanism 76 when the pressure oil is supplied. Moved to the left). The position in contact with the torque receiving member 68 via the conversion mechanism 76 is a release position at which the engagement force is released. The braking position is appropriately changed by the required braking force.

  The nut portion 68 c has a female screw 68 g on the inner periphery, and the female screw 68 g engages with a male screw 69 a formed on the outer periphery of the screw shaft 69. The screw shaft 69 is connected to the rotor shaft 80 a of the parking motor 80. The connection is performed by spline connection. That is, the screw shaft 69 is movable in the axial direction of the rotation axis L1 with respect to the rotor shaft 80a, and is coupled so as to be able to transmit torque in the rotational direction about the axis of the rotation axis L1.

  The screw shaft 69 moves the torque receiving member 68 in the axial direction by driving the parking motor 80. Movement of the torque receiving member 68 is performed at a braking position (position to the left in the vehicle width direction) that generates an engagement force between the rotating plate 66a and the fixed plate 66b and a release position (the vehicle width direction) It takes place between the right). The braking position at this time is a position of the braking position of the service brake mechanism 51 at which the engagement force necessary to maintain the stopped state of the vehicle can be obtained. The release position corresponds to an initial position described later in detail, and the initial position is appropriately changed by adjustment control described later in detail.

  The outer periphery of the rear end 69 b of the screw shaft 69 is fitted in the opening 79 a of the brake housing 79. The fitting is a fitting that can move in the axial direction of the output shaft 24, can rotate in the circumferential direction about the output shaft 24, and can ensure a fluid-tight state by an oil seal or the like. The parking motor 80, the screw shaft 69, the torque receiving member 68 and the like constitute a parking brake mechanism 52.

  The parking brake mechanism 52 is configured to maintain the frictional engagement between the rotating plate 66a and the fixed plate 66b even when the power of the vehicle is turned off. Specifically, the parking brake mechanism 52 moves the torque receiving member 68 toward the braking position by, for example, rotating the parking motor 80 forward.

  The screw shaft 69 has a flange portion 69c on the outer periphery, and a thrust bearing 81 is provided on the flange portion 69c, for example. The thrust bearing 81 is disposed between the flange portion 69c and the facing portion 79b of the brake housing 79 facing in the vehicle width direction with respect to the flange portion 69c, and the force acting in the axial direction of the output shaft 24 (thrust, Receive the thrust). A detector 82 for detecting an axial force transmitted along the axial direction from the screw shaft 69 is attached to the facing portion 79 b.

  The detector 82 may include, for example, a pair of pressure plates arranged to face each other in the vehicle width direction, and a strain gauge (both not shown), and the strain gauge may be sandwiched between the pair of pressure plates. The thrust bearing 81 is in contact with one pressing plate, and the opposing portion 79b is in contact with the other pressing plate. When an axial force (load) in the axial direction is applied to the screw shaft 69, the flange portion 69c is bent toward the right in the vehicle width direction even on the outer diameter side from the inner diameter side. The thrust bearing 81 receives the deformation caused by the bending of the flange portion 69c as an axial force. The pair of pressure plates and the strain gauges are formed in a ring shape having an opening for allowing the rear end 69b of the screw shaft 69 to pass through in the present embodiment. A plurality of strain gauges may be provided at positions separated in the radial direction from the axis of the rotation axis L1 and at positions obtained by equally dividing the circumference around the axis.

  The detector 82 detects the amount of displacement of the thrust bearing 81 in the axial direction that occurs when axial force in the axial direction is applied to the screw shaft 69, and sends information on the detected displacement to the control unit 83. The control unit 83 has a determination unit 83a, and the determination unit 83a determines the axial force based on the displacement amount. The detector 82 is not limited to detecting the axial deformation of the screw shaft 69. For example, the detector 82 is provided on the right side of the pressing plate 67a in the vehicle width direction, and the amount of deformation in the twisting direction of the pressing plate 67a. May be detected. Further, the detector 82 is not limited to a strain gauge, but may be a detector using, for example, a piezoelectric element or a pressure-sensitive element. The detector 82 and the controller 83 are an example of a detector in the embodiment of the present invention.

  When it is necessary to lock the parking, for example, when the shift lever 86 is switched to the parking position, the control unit 83 causes the parking motor 80 to rotate forward while monitoring the axial force determined by the determining unit 83a. The driver 87 is energized. Thereby, the torque receiving member 68 moves along the axial direction and toward the braking position. That is, the parking motor 80 applies a torque for generating a thrust along the axial direction to the torque receiving member 68. As a result, a frictional engagement force is generated on the friction plate 66.

  As the thrust is increased, the engagement force generated on the friction plate 66 is increased. The reaction force that resists the engagement force deforms the screw shaft 69 in the axial direction. When the amount of deformation becomes such that the parking lock can be performed, the determination unit 83a determines the axial force according to the amount of deformation, and the control unit 83 stops the energization of the motor driver 87. As a result, the driving of the parking motor 80 is stopped. As a result, the rotating plate 66a and the fixed plate 66b are maintained in a pressure-bonded state. Therefore, even when the power of the vehicle is turned off, the braking force can be maintained.

  Further, when the parking brake is released, the control unit 83 energizes the motor driver 87 to reverse the parking motor 80, for example, while monitoring the axial force determined by the determination unit 83a, and receives the torque receiving member. Move 68 towards the release position. Thereafter, when the determination unit 83a determines the amount of deformation (axial force) that can release the parking lock, the motor driver 87 is deenergized.

  The parking motor 80 has a rotation angle detection unit 84 that detects the rotation angle of the rotor shaft 80a. The rotation angle detection unit 84 sends information on the detected rotation angle to the control unit 83. The control unit 83 includes the storage unit 83b, and stores the information of the rotation angle at the time of obtaining the axial force at which the parking lock can be released as the initial position in the storage unit 83b each time the parking lock is released. That is, the controller 83 controls the nut portion 68c of the feed screw mechanism based on the rotation angle of the rotor shaft 80a, that is, the initial position in the axial direction of the torque receiving member 68, that is, the engagement based on the degree of wear of the friction plate 66. Adjust the force release position.

  Therefore, it is possible to suppress or prevent the play of the conversion mechanism 76 caused by the change of the gap of the friction surface of the friction plate 66 by using for a long time. That is, as the clearance of the friction surface of the friction plate 66 becomes wider, the adjustment of the initial position adjusts the initial position so that the torque receiving member 68 approaches the braking position. Further, since the pressing plate member 67 is pressed by the engagement force applying mechanism on the basis of the initial position of the torque receiving member 68 adjusted according to the clearance of the friction surface of the friction plate 66, the service brake mechanism 51 is normally operated. The braking force of the brake can always be maintained at the same braking force. Note that, instead of the feed screw mechanism and the parking motor 80, an actuator such as an electric cylinder may be used.

  FIG. 3 is a cross-sectional view showing an example of the first conversion mechanism shown in FIG. As shown in FIG. 3, the first conversion mechanism 76-1 is provided between the torque receiving plate 68 a and the pressing plate 67 a. A plurality of conversion mechanisms 76-1 are provided at predetermined intervals in the circumferential direction about the rotation axis L1. The conversion mechanism 76-1 includes a first groove 88 provided in the pressing plate 67a, a second groove 89 provided in the torque receiving plate 68a, and a ball inserted between the first groove 88 and the second groove 89. 91 is provided. Each of the first groove 88 and the second groove 89 has a substantially L-shaped cross section. The spheres 91 are formed substantially of a rigid metal or other material.

  The first groove 88 has a first cam surface 88 a and a second cam surface 88 b connected to the first cam surface 88 a. The second groove 89 has a third cam surface 89 a and a fourth cam surface 89 b connected to the third cam surface 89 a. The ball 91 is inserted between the first groove 88 and the second groove 89 so as to point-contact each of the first cam surface 88a, the second cam surface 88b, the third cam surface 89a, and the fourth cam surface 89b. There is. The spherical body 91, the first groove 88 and the second groove 89 are set in size and angle of the inner surface so that a slight gap 76a is generated between the pressing plate 67a and the torque receiving plate 68a.

  When torque directed in the circumferential direction is generated in the pressing plate 67a, the first cam surface 88a and the fourth cam surface 89b direct one of the first cam surface 88a and the fourth cam surface 89b to the other. It has become an inclined surface to approach. When torque directed in the circumferential direction is generated in the pressing plate 67a, the second cam surface 88b and the third cam surface 89a direct one of the second cam surface 88b and the third cam surface 89a to the other. It has become an inclined surface to approach. Specifically, the first cam surface 88a and the fourth cam surface 89b may be parallel. The second cam surface 88b and the third cam surface 89a may be parallel. The first cam surface 88a and the third cam surface 89a may have the same inclination angle with respect to the reference surface along the circumferential direction. The first cam surface 88a, the second cam surface 88b, the third cam surface 89a, and the fourth cam surface 89b constitute a front cam.

  The torque transmitted from the rotating plate 66a at the time of braking is applied circumferentially to the pressing plate 67a. The pressure receiving force (thrust) by the hydraulic pressure obtained from the hydraulic brake mechanism 53 at the time of braking is applied to the torque receiving plate 68 a toward the left in the vehicle width direction. When receiving the torque transmitted from rotating plate 66a at the time of braking, conversion mechanism 76 converts the torque into a thrust directed leftward in the vehicle width direction and adds the thrust to the pressing force to increase the pressing force. . The second conversion mechanism 76-2 has the same or the same configuration as that of the first conversion mechanism 76-1 described above, and thus the detailed description thereof will be omitted.

  FIG. 4 is a cross-sectional view showing another embodiment of the engagement force application mechanism. The first brake mechanism 100 shown in FIG. 5 is an electromagnetic friction brake mechanism. The first brake mechanism 100 includes an armature 98 and a coil 99. The armature 98 is formed in an annular shape by a magnetic body, and is axially movably provided inside the motor housing 21. The armature 98 has a pressing plate 98a, a pressing plate 98b, an outer peripheral groove 98c, and a coupling portion 98d. The pressing plate 98a presses the first rotating plate 66a-1. The pressed plate 98 b is disposed to face the torque receiving plate 68 a of the torque receiving member 68, and the pressure is transmitted from the torque receiving plate 68 a. The torque receiving member 68 is the same as or similar to that described in FIG.

  A first conversion mechanism 90-1 having the same configuration as the conversion mechanism 76-1 described with reference to FIG. 3 is provided between the pressure receiving plate 98b and the torque receiving plate 68a. The first conversion mechanism 90-1 converts the torque transmitted to the pressed plate 98b into the pressing force of the torque receiving plate 68a (engaging force pinched between the bottom surface 72d), and increases the pressing force. In addition, a second conversion mechanism 90-2 having the same configuration as the second conversion mechanism 76-2 described in FIG. 3 is provided between the second fixing plate 66b-2 and the bottom surface 72d of the fixing ring 72. . The second conversion mechanism 90-2 converts the torque transmitted to the second fixed plate 66b-2 into a pressing force toward the pressing plate 98a (engaging force sandwiching the pressing plate 98a), and the pressing force is converted. Boost power.

  The guide pin 73 is fitted between the outer peripheral groove 98 c and the inner peripheral groove 92 provided in the fixed ring 72. The outer peripheral groove 98c functions in the same manner as the outer peripheral groove 93 described in FIG. The outer circumferential groove 93, the inner circumferential groove 92, and the guide pins 73 are provided at predetermined intervals in the circumferential direction in the same manner as described with reference to FIG. The rectilinear groove 94 constituted by the inner circumferential groove 92 and the outer circumferential groove 98 c has a slight play with the guide pin 73 in the circumferential direction centering on the axis of the rotation axis L 1. The guide pin 73 and the rectilinear groove 94 prevent the rotation of the armature 98 in the circumferential direction beyond its play and allow the axial movement of the armature 98 relative to the fixed ring 72. Armature 98 has joint part 98d. The coupling portion 98 d axially movably supports the second fixing plate 66 b-2 and the third fixing plate 66 b-3 by spline coupling.

  The coil 99 is provided inside the fixed ring 72 and on the outer periphery of the armature 98, and sucks the armature 98 when energized. The suction direction of the armature 98 is such a direction (leftward in the vehicle width direction) that the pressing plate 98a presses the first rotating plate 66a-1 in the axial direction. Further, the attraction force of the armature 98 is larger than the biasing force of the return springs 74 and 75. In the output shaft 24 of the first motor 13, when the coil 99 is energized, the armature 98 moves to the left in the vehicle width direction. As a result, the rotating plate 66a and the fixed plate 66b are frictionally engaged and braked. The armature 98 performs substantially the same function as the pressing plate member 67, and is an example of the pressing member in the embodiment of the present invention.

  The pair of return springs 74 and 75 bias the armature 98 toward the torque receiving member 68 when the coil 99 is de-energized. The torque receiving member 68 has a nut portion 68c. The nut portion 68 c engages with an external thread 69 a provided on the screw shaft 69. The torque receiving member 68 is rotationally fixed as described above, and is moved between the braking position and the initial position by the driving of the parking motor 80. In this embodiment, the detector 82 is mounted at the same position as described in FIG. The initial position of the torque receiving member 68 is adjusted by controlling the rotation angle of the parking motor 80 based on the axial force obtained from the detector 82 when the parking lock is released. In FIG. 4, the same members as those described in FIG. 2 are assigned the same reference numerals and detailed explanations thereof will be omitted. Further, although the coil 99 is disposed on the outer diameter side of the armature 98 of the fixed ring 72, it may be disposed between the armature 98 and the partition wall 26.

  FIG. 5 is a cross-sectional view showing another embodiment in which the position of the detector is changed. As shown in FIG. 5, the detector 82 is attached to the torque receiving member 68. Specifically, the detector 82 is attached to the surface 68i on the opposite side to the armature 98 of the both surfaces facing in the axial direction of the rotation axis L1 of the torque receiving plate 68a. The surface 68i is deformed so as to twist in the circumferential direction about the axis line as torque is transmitted. The detector 82 detects the amount of deformation according to the twist. The determination unit 83a determines the torque to be transmitted based on the information obtained from the detector 82. Control unit 83 adjusts the initial position of torque receiving member 68 based on the determined torque. In FIG. 5, the same members as those described in FIG. 4 are assigned the same reference numerals and detailed explanations thereof will be omitted.

  FIG. 6 is a cross-sectional view showing another embodiment in which the position of the detector is changed. As shown in FIG. 6, the detector 82 is attached to a first motor 13 which is a driving motor. Specifically, the first motor 13 has stator teeth 102 attached to the stator yoke 101. In the stator teeth 102, a first support plate 103 and a second support plate 104 are disposed opposite to each other at both ends in the axial direction of the rotation axis L1. The first support plate 103 and the second support plate 104 are support plates for maintaining a gap (gap) between the stator 22 and the rotor 23 in a gap adjusted by an adjustment mechanism (not shown) at the time of assembly.

  A third conversion mechanism 106 is provided between one end of the stator teeth 102 and the first support plate 103, and a fourth conversion mechanism 107 is provided between the other end of the stator teeth 102 and the second support plate 104. ing. The third conversion mechanism 106 and the fourth conversion mechanism 107 have the same or similar configuration as the conversion mechanism 76 shown in FIG. That is, in the stator teeth 102, a reaction force with respect to the torque of the rotor 23 is generated. The third conversion mechanism 106 and the fourth conversion mechanism 107 convert the reaction force generated on the stator teeth 102 into thrust in the axial direction of the rotation axis L1. The second support plate 104 is provided so as to protrude toward the partition 21a of the motor housing 21 on the inner diameter side of the flange portion 104a whose length in the radial direction is longer than that of the first support plate 103 in the cross section and the flange portion 104a. It has a tube portion 104b. The front end of the cylindrical portion 104 b is fixed to the partition 21 a of the motor housing 21. The detector 82 is attached to the flange portion 104a, and detects the amount of deformation of the second support plate 104 in which the flange portion 104a is bent in the axial direction with respect to the cylindrical portion 104b as an axial force along the axial direction. The first support plate 103 and the second support plate 104 are prevented from rotating in the circumferential direction about the axis of the rotation axis L1, and can be deformed (moved) in the axial direction, so they will be described with reference to FIG. The same action as the torque receiving member 68 is performed.

  Although the embodiment shown in FIG. 6 includes the first conversion mechanism 90-1 and the second conversion mechanism 90-2 described in FIG. 4 in addition to the third conversion mechanism 106 and the fourth conversion mechanism 107. The present invention is not limited to this, and the first conversion mechanism 90-1 and the second conversion mechanism 90-2 may be omitted, and only the third conversion mechanism 106 and the fourth conversion mechanism 107 may be provided. In FIG. 6, the same members as those described in FIG. 4 are assigned the same reference numerals and detailed explanations thereof will be omitted.

  As mentioned above, this invention is not limited to the structure shown by embodiment mentioned above, Comprising: It can change suitably and can be implemented in the range which claims. For example, the present invention may be used in a caliper type brake device in which a rotating plate is sandwiched by a pair of fixing members. Further, although the rotating plate 66a is described as being configured to rotate by the torque transmitted from the first motor 13, it may alternatively be configured to be rotated by the torque transmitted from the engine. Furthermore, the initial position of the torque receiving member 68 is not limited to when the parking lock is released. For example, when the vehicle is stopped, the parking lock and its release may be quickly performed and adjusted to the release.

  In each of the above embodiments, the initial position of the torque receiving member 68 at the time of releasing the parking lock is adjusted based on the information obtained from the detector 82. However, the present invention is not limited to this. The detector 82 may be used as a detector for detecting the brake torque of the mechanism 51. In each of the above embodiments, the torque generated in the friction plate or the axial force obtained by converting the torque is detected. However, the present invention is not limited thereto. For example, the torque generated in the regenerative braking mechanism or the torque is converted It may include a detector that detects the axial force that has been generated.

  Next, technical ideas that can be grasped from the above embodiments will be additionally described below.

(Supplementary Note 1)
The rotating member and the fixing are performed by being pressed in the axial direction of a rotating member that is rotated by a torque transmitted from a driving force source, a fixed member disposed opposite to the rotating member, and a rotating shaft of the rotating member. A brake device comprising: a pressing member generating an engagement force with the member; and an elastic member applying an elastic force against the engagement force to the pressing member.
A torque transmitting member for transmitting the torque transmitted from the rotating member to the fixed member by giving the fixed member a play along at least the rotation direction of the rotating member;
A torque receiving member that is prevented from rotating in the circumferential direction about the axis and receives the torque transmitted from the torque transmitting member;
A conversion mechanism that converts the torque transmitted to the torque receiving member into thrust in the axial direction, and applies the converted thrust to the engagement force;
A detection unit is provided that detects a torque transmitted from the rotating member by detecting a reaction force generated with the engagement force, or a detection unit that determines an axial force in the axial direction obtained by converting the torque. Brake equipment.

(Supplementary Note 2)
In the brake device described in Appendix 1,
The torque receiving member is caused to generate a thrust whose rotational motion is converted into a linear motion, to move the torque receiving member in the axial direction, and the torque obtained based on the torque or the axial force obtained from the detection unit. A brake device comprising an actuator for adjusting the position of the receiving member in the axial direction.

(Supplementary Note 3)
In the brake device according to Supplementary Note 1 or 2,
The said conversion mechanism is provided between the said press member and the said torque receiving member, The brake apparatus characterized by the above-mentioned.

(Supplementary Note 4)
In the brake device according to any one of supplementary notes 1 to 3,
The said conversion mechanism is provided between the said fixing member and a predetermined fixed ring, The brake apparatus characterized by the above-mentioned.

(Supplementary Note 5)
In the brake device according to any one of supplementary notes 1 to 4,
A movable ring disposed on the inner diameter side of the fixed ring and supporting the fixed member;
The torque transmission member includes a rectilinear groove extending rectilinearly in the axial direction between an inner peripheral portion of a predetermined fixed ring and an outer peripheral portion of the movable ring, and a rolling element inserted in the rectilinear groove The rectilinear groove has a clearance in the circumferential direction about the axis with respect to the rolling element, and the movable ring can be moved in the axial direction relative to the fixed ring and the clearance is exceeded A brake device characterized by preventing rotation of the movable ring in the circumferential direction.

(Supplementary Note 6)
In the brake device described in Appendix 5,
The said elastic member is an inside of the said rectilinear groove, and is provided in the both sides of the said rolling element, respectively, The brake apparatus characterized by the above-mentioned.

  DESCRIPTION OF SYMBOLS 10 ... Drive device, 11 ... 1st drive wheel, 12 ... 2nd drive wheel, 13 ... 1st motor, 14 ... 2nd motor, 15 ... 1st power transmission mechanism, 16 ... 2nd power transmission mechanism, 17 ... difference 18, 100: first brake mechanism, 19: second brake mechanism, 51: service brake mechanism, 52: parking brake mechanism, 66: friction plate, 67: pressing plate member, 68: torque receiving member, 69: Screw shaft 71: Movable ring 72: Fixed ring 73: Guide pin 74, 75: Return spring 76, 90: Conversion mechanism 80: Parking motor 83: Control section 94: Straight groove 103: First support plate, 104: second support plate, 106: first conversion mechanism, 107: second conversion mechanism.

Claims (1)

A rotating member rotated by a torque transmitted from a driving force source,
A fixing member disposed opposite to the rotating member;
A pressing member that generates an engagement force between the rotating member and the fixing member by being moved in the axial direction of the rotating shaft of the rotating member;
And a resilient member for applying an elastic force against the engagement force to the pressing member.
A torque transmitting member for causing the fixed member to have at least a play along the rotation direction of the rotating member to transmit torque transmitted from the rotating member to the fixed member;
A conversion mechanism that converts torque transmitted from the torque transmission member into thrust in the axial direction, and applies the converted thrust to the engagement force;
It is characterized by comprising a detection unit that determines a torque transmitted from the rotating member by detecting a reaction force generated as a result of the engagement force, or an axial force in the axial direction obtained by converting the torque. Brake equipment.

Images