Electric braking system and method for assembling the electric braking system

Abstract

To provide an easily assembled electric braking device. [Solution] The electric braking device (1) is configured such that a claw portion (21A) having a occlusal claw (210) and a pressing mechanism (121) are mechanically separable, and comprises a circuit board (11) that supplies power to an electric motor (23) and an electric unit (120), a first case (10) to which the circuit board (11), the electric unit (120) and the pressing mechanism (121) are fixed, and a second case (20) to which the claw portion (21A) and a ratchet gear (22) are fixed.

Description

Technical Field

[0001] The present disclosure relates to an electric braking device and a method for assembling the electric braking device.

Background Art

[0002] Patent Document 1 discloses a braking device in which an electric motor and a lock mechanism are assembled to a gear case that houses a speed reducer, and a board case that houses a circuit board is assembled to the gear case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the braking device disclosed in Patent Document 1, when assembling the gear case and the board case, the electric motor housed in the gear case and the solenoid of the lock mechanism are arranged in the same assembly and are electrically connected to the circuit board. In these electrical connections, since the dimensional tolerances and assembly tolerances of each component are stacked, high dimensional accuracy and assembly accuracy are required for each component. One aspect of the present disclosure aims to provide an electric braking device that can be easily assembled.

Means for Solving the Problems

[0005] To solve the above problems, an electric braking device according to one aspect of the present disclosure amplifies the rotational torque of an electric motor with a reduction gear, converts the rotational torque amplified by the reduction gear into axial force with a linear motion conversion mechanism, and uses the axial force converted by the linear motion conversion mechanism to press a friction member against a rotating member that rotates together with the wheel of a vehicle, thereby generating a braking force on the wheel, comprising: a ratchet gear that is rotationally driven by the rotational torque of the electric motor; and a drive unit having a meshing pawl that transitions the state of the meshing pawl between a meshed state in which it is engaged with the ratchet gear and a non-mesh state in which the meshing state is released. The electric braking device comprises, the drive unit having a claw portion having the occlusal claw, a pressing mechanism that presses the claw portion to transition the occlusal claw from the non-occlusal state to the occlusal state, and an electric unit that drives the pressing mechanism, wherein the claw portion and the pressing mechanism are configured to be mechanically separable, and the device comprises a circuit board that supplies power to the electric motor and the electric unit, a first case to which the circuit board, the electric unit and the pressing mechanism are fixed, and a second case which is a separate case from the first case to which the claw portion and the ratchet gear are fixed. [Effects of the Invention]

[0006] According to one aspect of this disclosure, an electric braking system can be easily assembled. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram showing one example of the configuration of an electric braking system according to one embodiment of the present disclosure. [Figure 2] This diagram shows the relationship between the occlusal teeth and the ratchet gear. [Figure 3] This figure is used to illustrate a method for assembling an electric braking device according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0008] Figure 1 is a schematic diagram showing one configuration example of an electric braking device according to one embodiment of the present disclosure. The electric braking device 1 shown in Figure 1 is a braking device that generates braking force on the wheels of a vehicle by pressing a friction member 27 against a rotating member 30 that rotates together with the wheels of the vehicle. The electric braking device 1 comprises a first case 10, a circuit board 11, a first drive unit 12, a second case 20, a second drive unit 21, a ratchet gear 22, an electric motor 23, a reduction gear 24, a linear motion conversion mechanism 25, a piston 26, a friction member 27, and a cylinder 28.

[0009] The first case 10 has a first part 10A and a second part 10B. The circuit board 11 and the first drive unit 12 are fixed to the first part 10A. The second part 10B is the lid of the first part 10A. The circuit board 11 controls various parts of the electric braking device 1. The circuit board 11 has a first connection part 11A and a second connection part 11B. The first connection part 11A and the second connection part 11B are, for example, terminal holes into which power supply pins can be inserted. The circuit board 11 supplies power to the devices electrically connected to the first connection part 11A and the second connection part 11B. One of the front and back sides of the circuit board 11 faces the second part 10B, and the other side faces the second case 20. Between the circuit board 11 and the second case 20 is a first fixing part 10C for fixing the first drive unit 12, and a housing part 10D for housing the second drive unit 21, ratchet gear 22, etc., which are fixed to the second case 20.

[0010] The first drive unit 12 and the second drive unit 21 are examples of drive units. The first drive unit 12 and the second drive unit 21 are configured to be mechanically separable. The first drive unit 12 is fixed to the first fixed part 10C of the first case 10, and the second drive unit 21 is fixed to the second case 20. The first drive unit 12 is, for example, a solenoid actuator. The first drive unit 12 includes an electric motor 120, a pressing mechanism 121, and a first power supply pin 122. The second drive unit 21 has a claw portion 21A and a case 21B.

[0011] The first power supply pin 122 is electrically connected to the circuit board 11. The first drive unit 12 is supplied with power from the circuit board 11 via the first power supply pin 122. The motor unit 120 is, for example, a solenoid coil. The pressing mechanism 121 is, for example, a plunger (movable iron core). The motor unit 120 drives the pressing mechanism 121.

[0012] The claw portion 21A of the second drive unit 21 is, for example, a locking pin having an occlusal claw 210, a locking portion 211, and a biasing portion 212. The occlusal claw 210 is a claw that can occlude with the teeth of the ratchet gear 22. The biasing part 212 biases the pawl portion 21A in a direction that causes the occlusal pawl 210 to move away from the ratchet gear 22. The locking portion 211 locks the claw portion 21A to the inside of the case 21B. The locking portion 211 is pressed against the inner wall of the case 21B by the biasing force of the biasing portion 212. Case 21B has an opening 21C on the surface facing the first drive unit 12 into which the pressing mechanism 121 can be inserted.

[0013] The electric motor 23 has a motor shaft 230 and a second power supply pin 231. The second power supply pin 231 is electrically connected to the circuit board 11. Power is supplied to the electric motor 23 from the circuit board 11 via the second power supply pin 231. The ratchet gear 22 is fixed to the motor shaft 230 of the electric motor 23. The rotational torque of the electric motor 23 is amplified by the reduction gear 24 and transmitted to the linear motion conversion mechanism 25. The linear motion conversion mechanism 25 has a rotating shaft 25A and a linear motion section 25B. The linear motion conversion mechanism 25 converts the rotational torque of the electric motor 23 into axial force.

[0014] The piston 26 is fixed to the linear motion section 25B of the linear motion conversion mechanism 25. The linear motion section 25B and the piston 26 move linearly in a direction corresponding to the rotation direction of the motor shaft 230 of the electric motor 23. The axial force converted linearly by the linear motion conversion mechanism 25 causes the piston 26 to press the friction member 27 against the rotating member 30.

[0015] When a magnetic field is generated due to the flow of current through the winding of the electric unit 120, the tip 121A of the pressing mechanism 121 protrudes from the first part 10A of the first case 10 and contacts the contact surface 211A of the locking part 211 of the pawl part 21A through the opening 21C. The pressing mechanism 121 presses the pawl part 21A toward the ratchet gear 22 against the biasing force of the biasing part 212.

[0016] FIG. 2 is a diagram showing the relationship between the engaging pawl and the ratchet gear. The engaging pawl 210 is configured to be able to transition between an engaged state shown by a dashed line in FIG. 2 and a non-engaged state shown by a solid line in FIG. 2. In the engaged state, the engaging pawl 210 is engaged with the teeth of the ratchet gear 22. In the engaged state, the motor shaft 230 is rotatable in the forward rotation direction Fwd, but is restricted from rotating in the reverse rotation direction Rvs. The non-engaged state is a state in which the engaged state is released, and the engaging pawl 210 is not engaged with the teeth of the ratchet gear 22. In the non-engaged state, the motor shaft 230 is rotatable in both the forward rotation direction Fwd and the reverse rotation direction Rvs.

[0017] When the pressing mechanism 121 presses the pawl part 21A against the biasing force of the biasing part 212, the engaging pawl 210 of the pawl part 21A is pressed against the ratchet gear 22. When the reaction force of the pressing force is transmitted in the pressed state and the motor shaft 230 is rotated in the reverse rotation direction Rvs, and the ratchet gear 22 abuts against the engaging pawl 210, the engaging pawl 210 transitions to the engaged state.

[0018] After the engaging pawl 210 enters the engaged state, it does not transition to the non-engaged state while a rotational torque is generated in the reverse rotation direction Rvs. To release the engaged state of the engaging pawl 210, for example, the following steps are taken. The electric motor 23 generates a motor torque to make the rotational torque in the reverse rotation direction Rvs not generated, and rotates the ratchet gear 22 in the forward rotation direction Fwd. By setting the current flowing through the winding of the electric unit 120 to be below a predetermined value, the biasing force of the biasing part 212 separates the engaging pawl 210 from the ratchet gear 22.

[0019] FIG. 3 is a diagram used to explain a method of assembling an electric braking device according to an embodiment of the present disclosure. In the following description, a method of assembling the first drive unit 12 and the second drive unit 21 among the methods of assembling the electric braking device 1 will be described. The method of assembling the electric braking device 1 described using FIG. 3 includes a first fixing step, a second fixing step, a motor mounting step, and an assembling step.

[0020] (First Fixing Step) The first fixing step is a step of fixing the circuit board 11 and the first drive unit 12 to the first case 10. More specifically, in the first fixing step, the electric unit 120 and the pressing mechanism 121 are fixed to the first fixing portion 10C of the first portion 10A of the first case 10, and the circuit board 11 is fixed to the first portion 10A of the first case 10.

[0021] The first drive unit 12 may be fixed to the first fixing portion 10C by fastening members such as screws, snap fits, etc. When the first drive unit 12 is fixed to the first case 10 by a fastening member, an insert nut or the like may be provided on the first case 10. The electric unit 120 of the first drive unit 12 may be insert-molded during the molding of the first case 10.

[0022] When fixing the circuit board 11 to the first case 10, the fixing position of the circuit board 11 with respect to the first case 10 is determined so that the first power supply pin 122 of the first drive unit 12 is connected to the first connection portion 11A. When the first power supply pin 122 of the first drive unit 12 is connected to the first connection portion 11A of the circuit board 11, power can be supplied from the circuit board 11 to the first drive unit 12.

[0023] (Motor Mounting Step) The motor mounting process involves fixing the electric motor 23 to the second case 20. The electric motor 23 is mounted to the second case 20 so that the ratchet gear 22 can be fixed in a position that allows the occlusal jaw 210 to transition between an occlusal state and an unocclusal state. In Figure 3, the second drive unit 21 is fixed to the first surface 20A of the second case 20, and the electric motor 23 is mounted to the second surface 20B opposite the first surface 20A. Fasteners such as screws or snap-fit ​​fasteners may be used to mount the electric motor 23. The motor shaft 230 of the electric motor 23 penetrates the second case 20 from the second surface 20B to the first surface 20A. The second power supply pin 231 of the electric motor 23 extends from the first surface 20A side to the second surface 20B side of the second case 20 in a position that does not come into contact with the ratchet gear 22, etc., when assembling the electric braking device 1.

[0024] (Second fixing process) The second fixing step is to fix at least the claw portion 21A and the ratchet gear 22 to the second case 20. The ratchet gear 22 is fixed to the motor shaft 230 of the electric motor 23 which is fixed to the second case 20 by the motor mounting step.

[0025] The claw portion 21A may, for example, be incorporated into the case 21B and fixed to the first surface 20A of the second case in the state of the second drive unit 21. The case 21B may be manufactured integrally with the second case 20, in which case the claw portion 21A may be insert-molded during the molding of the second case 20. Alternatively, the claw portion 21A may be inserted into the case 21B which is integrally molded with the second case 20. In the second fixing step, the reducer 24, the linear motion conversion mechanism 25, etc., are also fixed to the second case 20.

[0026] (Assembly process) The assembly process is performed after the first fixing process, the motor mounting process, and the second fixing process. The first part 10A of the first case 10 after the first fixing process and the second case 20 after the second fixing process are assembled. For example, each part fixed to the first side 20A of the second case 20 is housed in the housing part 10D of the first part 10A so that the second power supply pin 231 of the electric motor 23 attached to the second case 20 is connected to the second connection part 11B of the circuit board 11 fixed to the first part 10A. Power is supplied from the circuit board 11 to the electric motor 23 by connecting the second power supply pin 231 of the electric motor 23 to the second connection part 11B of the circuit board 11. After connecting the second power supply pin 231 to the second connection part 11B and housing the second drive unit 21 and the ratchet gear 22 in the housing part 10D, the second case 20 and the first part 10A are fixed together. For fixing the second case 20 to the first part 10A, fastening members such as screws or snap-fits may be used. Then, the second part 10B is fixed to the first part 10A. For fixing the second part 10B to the first part 10A, fastening members such as screws, snap-fits, welding, etc. may be used.

[0027] The area of ​​the opening 21C and the area of ​​the contact surface 211A of the second drive unit 21 are larger than the area of ​​the contact surface of the tip portion 121A of the pressing mechanism 121. Therefore, in the assembly process, sufficient tolerance can be ensured in the assembly accuracy between the pressing mechanism 121 and the claw portion 20A. The area of ​​the opening 21C and the area of ​​the contact surface 211A of the second drive unit 21 may be brought closer to the area of ​​the contact surface of the tip portion 121A of the pressing mechanism 121, as long as sufficient tolerance can be ensured.

[0028] The tip portion 121A of the pressing mechanism 121 and the case 21B of the second drive unit 21 may be provided with a tapered portion such that the pressing mechanism 121 retracts toward the first fixing portion 10C when the pressing mechanism 121 comes into contact with the case 21B during the assembly process. This reduces the possibility of the pressing mechanism 121 being damaged or the surface of the case 21B being scratched during the assembly process.

[0029] The first fixing process may be performed simultaneously with the motor mounting process and the second fixing process, or before the motor mounting process, or after the second fixing process and before the assembly process.

[0030] [Variation] In the above embodiment, the claw portion 21A of the second drive unit 21 is provided with a locking portion 211. However, the claw portion 21A of the second drive unit 21 does not need to have a locking portion 211, as long as it is configured so that it does not come out of the case 21B due to the biasing force of the biasing portion 212. For example, the second drive unit 21 may have a portion on the opening 21C side of the case 21B that locks the claw portion 21A but does not lock the pressing mechanism 121. Also, the area of ​​the tip portion 121A of the pressing mechanism 121 may be larger than the contact surface 211A of the locking portion 211 of the claw portion 21A, as long as it is large enough to pass through the opening 21C of the case 21B.

[0031] In the above embodiment, the occlusal claw 210 transitions to an occlusal state when the pressing mechanism 121 pushes the claw portion 21A against the biasing force of the biasing portion 212. Alternatively, the occlusal claw 210 transitions to an unocclusal state when the ratchet gear 22 is rotated in the Fwd direction, and the biasing force of the biasing portion 212 separates the occlusal claw 210 from the ratchet gear 22. However, the method for transitioning the state of the occlusal claw 210 between the occlusal state and the unocclusal state is not limited to the above method. For example, the first drive unit 12 may be composed of an electric motor and a linear motion conversion mechanism. Alternatively, a lever or the like may be provided on the claw portion 21A, and the pressing mechanism 121 may operate the lever or the like.

[0032] In the above embodiment, the ratchet gear 22 is fixed to the motor shaft 230 of the electric motor 23. However, the ratchet gear 22 does not have to be directly fixed to the motor shaft 230 of the electric motor 23, as long as it is configured to be rotationally driven by the rotational torque of the electric motor 23. If the ratchet gear 22 is not fixed to the motor shaft 230 of the electric motor 23, the ratchet gear 22 may be fixed to the second case 20 in the second fixing step, and then the electric motor 23 may be fixed to the second case 20 in the motor mounting step. If the ratchet gear 22 is not fixed to the motor shaft 230 of the electric motor 23, the electric motor 23 does not have to be fixed to the second case.

[0033] 〔summary〕 An electric braking device according to one aspect of the present disclosure is an electric braking device that amplifies the rotational torque of an electric motor with a reduction gear, converts the rotational torque amplified by the reduction gear into axial force with a linear motion conversion mechanism, and uses the axial force converted by the linear motion conversion mechanism to press a friction member against a rotating member that rotates together with the wheel of a vehicle, thereby generating a braking force on the wheel, comprising: a ratchet gear that is rotationally driven by the rotational torque of the electric motor; and a drive unit that has a meshing pawl and transitions the state of the meshing pawl between a meshed state in which it is engaged with the ratchet gear and a non-mesh state in which the meshing state is released. In the electric braking device, the drive unit includes a claw portion having the occlusal claw, a pressing mechanism that presses the claw portion to transition the occlusal claw from the non-occlusal state to the occlusal state, and an electric unit that drives the pressing mechanism, wherein the claw portion and the pressing mechanism are configured to be mechanically separable, and the device includes a circuit board that supplies power to the electric motor and the electric unit, a first case to which the circuit board, the electric unit and the pressing mechanism are fixed, and a second case which is a separate case from the first case to which the claw portion and the ratchet gear are fixed. In the electric braking device of this disclosure, a pawl portion having a pawl that can engage with a ratchet gear and a pressing mechanism are configured to be mechanically separable. This allows the pawl portion and the pressing mechanism to be separated and fixed to a first case and a second case, respectively. Here, the circuit board and the electric unit are components that require reliable electrical connection. Furthermore, the clenching jaws and the ratchet gear are components that require high assembly precision. By fixing the circuit board and the electric unit that receives power from the circuit board to the first case, the electrical connection between the circuit board and the electric unit can be easily ensured. By fixing the clenching jaws and the ratchet gear to the second case, the assembly precision between the clenching jaws and the ratchet gear can be easily ensured. Therefore, the electric braking device can be easily assembled.

[0034] In one aspect of the present disclosure, the contact surface of the pressing mechanism and the contacted surface of the claw, which come into contact when the pressing mechanism presses the claw, have different areas. In the electric braking device of this disclosure, the contact surface of the pressing mechanism and the contacted surface of the claw that come into contact when the pressing mechanism presses the claw are made to have different areas. This ensures that a tolerance is maintained in the assembly accuracy between the claw and the pressing mechanism, thereby facilitating the assembly of the first case and the second case.

[0035] In an electric braking device according to one aspect of the present disclosure, the electric motor is mounted in the second case and has a power supply pin that receives power from the circuit board, and the power supply pin contacts a connection portion provided on the circuit board. In the electric braking device of this disclosure, the electric motor is mounted in the second case, and power is supplied to the electric motor via the electric motor's power pins, which are in contact with the connection points on the circuit board. As described above, the electrical connection between the electric motor and the circuit board is ensured. Therefore, when assembling the first and second cases, care must be taken only to ensure that the electric motor's power pins are in contact with the connection points on the circuit board. In other words, assembly of the first and second cases is made easy.

[0036] An assembly method for an electric braking device according to one aspect of the present disclosure is an assembly method for an electric braking device according to the above aspect, comprising: a first fixing step of fixing the circuit board, the electric unit, and the pressing mechanism to the first case; a second fixing step of fixing the pawl and the ratchet gear to the second case; and an assembly step of assembling the first case and the second case after the first fixing step and the second fixing step. The first fixing step makes it easy to ensure the electrical connection between the circuit board and the motor, as described above. The second fixing step makes it easy to ensure the assembly accuracy between the meshing pawl and the ratchet gear, as described above.

[0037] An electric braking device according to one aspect of the present disclosure is a method for assembling the electric braking device according to the above aspect, comprising: a first fixing step of fixing the circuit board, the electric unit, and the pressing mechanism to the first case; a motor mounting step of attaching the electric motor to the second case; a second fixing step of fixing the pawl and the ratchet gear to the second case; and an assembly step of aligning the power supply pin of the electric motor with the connection part of the circuit board after the first fixing step, the second fixing step, and the motor mounting step, and assembling the first case and the second case. The first and second cases can be easily assembled as described above through the first fixing process, the second fixing process, the motor mounting process, and the assembly process.

[0038] [Additional Notes] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. [Explanation of Symbols]

[0039] 1 Electric braking device 10. Case 1 11 Circuit board 11A First connection section 11B Second connection section 12 First drive unit 20. Case 2 21 Second drive unit 22 Ratchet Gears 23 Electric motor 24 Reducer 25 Linear motion conversion mechanism 27 Friction Members 30 Rotating Member 120 Electric part 121 Pressing mechanism 121A Tip 211A Contacted surface 231 Second power supply pin

Claims

1. An electric braking device that amplifies the rotational torque of an electric motor with a reduction gear, converts the rotational torque amplified by the reduction gear into axial force with a linear motion conversion mechanism, and uses the axial force converted by the linear motion conversion mechanism to press a friction member against a rotating member that rotates together with the vehicle's wheel, thereby generating a braking force on the wheel, A ratchet gear that is rotationally driven by the rotational torque of the aforementioned electric motor, An electric braking device comprising an occlusal claw and a drive unit that transitions the state of the occlusal claw between an occlusal state in which it is engaged with the ratchet gear and an unocclusal state in which the occlusal state is released, The drive unit includes a nail portion having the occlusal nail, a pressing mechanism that presses the nail portion to transition the occlusal nail from the non-occlusal state to the occlusal state, and an electric unit that drives the pressing mechanism, wherein the nail portion and the pressing mechanism are configured to be mechanically separable. A circuit board that supplies power to the electric motor and the motorized part, A first case in which the circuit board, the electric unit, and the pressing mechanism are fixed, A second case, which is a separate case from the first case, to which the pawl portion and the ratchet gear are fixed, An electric braking system characterized by having the following features.

2. The electric braking device according to claim 1, wherein the contact surface of the pressing mechanism and the contacted surface of the claw that come into contact when the pressing mechanism presses the claw have different areas.

3. The electric motor is mounted in the second case and has power supply pins that receive power from the circuit board. The electric braking device according to claim 1 or 2, wherein the power supply pin contacts a connection portion provided on the circuit board.

4. A method for assembling an electric braking device according to claim 1 or 2, A first fixing step involves fixing the circuit board, the electric unit, and the pressing mechanism to the first case. A second fixing step involves fixing the pawl portion and the ratchet gear to the second case, After the first fixing step and the second fixing step, an assembly step is performed to assemble the first case and the second case, A method for assembling an electric braking system, including [a specific component].

5. A method for assembling an electric braking device according to claim 3, A first fixing step involves fixing the circuit board, the electric unit, and the pressing mechanism to the first case. A motor mounting step of attaching the electric motor to the second case, A second fixing step involves fixing the pawl portion and the ratchet gear to the second case, After the first fixing step, the second fixing step and the motor mounting step, an assembly step is performed in which the power supply pins of the electric motor and the connection portion of the circuit board are aligned and the first case and the second case are assembled. A method for assembling an electric braking system, including [a specific component].

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