Braking device

Abstract

To provide a braking device capable of maintaining brake force without complicating a shape of a rotary member.SOLUTION: A braking device increases brake force by rotating a rotating shaft 24a of an electric motor to a brake force increase direction Y1, and decreases the brake force by rotating the rotating shaft 24a to a brake force decrease direction Y2. The braking device includes a rotary member 31 which rotates in conjunction with the rotating shaft 24a, a guide member 33 which is disposed away from the rotary member 31, a lock member 35 which can be arranged at a fastening position and a retreat position, and a moving device 100. When the rotary member 31 is rotated to the brake force decrease direction Y2 in a state where the lock member 35 is positioned at the fastening position, force for fastening the lock member 35 between the rotary member 31 and the guide member 33 becomes large, and further rotation of the rotary member 31 to the brake force decrease direction Y2 is stopped.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a braking system for a vehicle. [Background technology]

[0002] Patent Document 1 describes an example of a braking device that can apply a braking force to a vehicle according to the drive amount of an electric motor. In this braking device, when increasing the braking force of the vehicle, the electric motor is driven so that the rotating shaft of the electric motor rotates in a direction that increases the braking force. On the other hand, when decreasing the braking force, the electric motor is driven so that the rotating shaft rotates in a direction that decreases the braking force, which is the opposite direction to the direction that increases the braking force.

[0003] The braking device described in Patent Document 1 has a braking force retention mechanism. The braking force retention mechanism retains the braking force by restricting rotation of the rotating shaft in a direction to reduce the braking force. That is, the braking force retention mechanism has a ratchet gear and a pawl member provided on the rotating shaft. The pawl member is movable in an advancing direction, which brings its tip closer to the ratchet gear, and in a retracting direction, which moves its tip away from the ratchet gear. When the rotating shaft is rotated in a direction to reduce the braking force with the tip of the pawl member in contact with the ratchet gear, the tip of the pawl member engages with the teeth of the ratchet gear. This engagement between the teeth and the tip restricts further rotation of the rotating shaft in the direction to reduce the braking force, thereby retaining the braking force. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6248588 Summary of the Invention [Problem to be solved by the invention]

[0005] In the braking force retaining mechanism, when the tip of the pawl member is engaged with the teeth of the ratchet gear, it is necessary to provide the ratchet gear with a device that satisfies the following two points. - The movement of the claw member in the retraction direction can be restricted. - The ratchet gear must be able to restrict rotation in the direction that reduces the braking force.

[0006] If a ratchet gear is constructed to satisfy these two requirements, the shape of the ratchet gear will end up being complicated. [Means for solving the problem]

[0007] A braking device that solves the above problem is a device that applies braking force to a vehicle using an electric motor as a power source. The braking device includes: a rotating member that is rotationally driven by the electric motor and rotates in a braking force increasing direction in which the braking force increases and in a braking force decreasing direction in which the braking force decreases; a guide member that is positioned at a distance from the rotating member; a locking member that is movable between a clamping position where the rotating member is clamped between the rotating member and the guide member when the rotating member rotates and a retracted position where the rotating member is not clamped between the rotating member and the guide member even when the rotating member rotates; and a moving device that moves the locking member between the clamping position and the retracted position. When the rotating member is rotated in the braking force decreasing direction with the locking member positioned at the clamping position, the locking member is clamped between the rotating member and the guide member, and the clamping force between the rotating member and the guide member increases, stopping further rotation of the rotating member in the braking force decreasing direction.

[0008] According to the above configuration, the vehicle's braking force can be increased by driving the electric motor so that the rotating member rotates in a direction that increases the braking force. To maintain the braking force, the movement device is operated to move the locking member from the retracted position to the clamping position. When the rotating member rotates in a direction that decreases the braking force in this state, the rotation of the rotating member displaces the locking member in a direction corresponding to the direction in which the braking force decreases. This increases the clamping force that clamps the locking member between the rotating member and the guide member. As a result, the engagement force generated between the rotating member and the locking member increases, stopping the rotation of the rotating member in the direction that decreases the braking force. This maintains the braking force.

[0009] In other words, with the above configuration, since the rotation of the rotating member in the direction of decreasing the braking force can be restricted by increasing the clamping force, it is not necessary to use a member with a complex shape as the rotating member. Therefore, with the above configuration, it is possible to maintain the braking force without having to make the shape of the rotating member complex. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a braking device according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a locking device in the braking device. [Figure 3] FIG. 3 is a schematic diagram showing the locking device. [Figure 4] FIG. 4 is a diagram showing the operation of the locking device. [Figure 5] FIG. 5 is a diagram showing the operation of the locking device. [Figure 6] FIG. 6 is a diagram showing the operation of the locking device. [Figure 7] FIG. 7 is a schematic diagram showing a part of a locking device in a braking device according to the second embodiment. [Figure 8] FIG. 8 is a schematic diagram showing a locking device in a braking device according to a third embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a locking device in a braking device according to a fourth embodiment. [Figure 10]FIG. 10 is a schematic diagram showing the locking device. [Figure 11] FIG. 11 is a schematic diagram showing a modified example of the locking device. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) A first embodiment of a braking device will be described below with reference to FIGS. FIG. 1 shows a braking device 20 provided on a vehicle.

[0012] <Overall configuration of braking device 20> The braking device 20 includes a brake disc 21 that rotates integrally with the wheel 10, and a brake caliper 22 that is supported on the vehicle body. The brake disc 21 is the part of the braking device 20 that is subjected to friction.

[0013] The brake caliper 22 supports two friction materials 23. With the brake disc 21 as the center, one of the two directions along the axle 11 to which the wheel 10 is connected is designated as a first axle direction X1, and the other is designated as a second axle direction X2. At this time, one of the two friction materials 23 is positioned further in the first axle direction X1 than the brake disc 21, and the other friction material 23 is positioned further in the second axle direction X2 than the brake disc 21. Each friction material 23 is displaceable so as to move relatively closer to and farther away from the brake disc 21. The two friction materials 23 sandwich the brake disc 21, thereby applying a braking force to the vehicle.

[0014] The brake caliper 22 is provided with an electric motor 24, a reduction mechanism 25, and a linear motion conversion mechanism 26. The electric motor 24 has a rotating shaft 24a that rotates when driven by the electric motor 24. Driving the electric motor 24 when increasing the braking force of the vehicle is referred to as "forward driving," and driving the electric motor 24 when decreasing the braking force is referred to as "reverse driving." Furthermore, the rotation direction of the rotating shaft 24a when the electric motor 24 drives forward is referred to as the "braking force increasing direction Y1," and the rotation direction of the rotating shaft 24a when the electric motor 24 drives reverse is referred to as the "braking force decreasing direction Y2" (see FIG. 2). The braking force decreasing direction Y2 is the opposite direction to the braking force increasing direction Y1.

[0015] The reduction mechanism 25 has a plurality of gears 25a and a shaft member 25b that functions as the output shaft of the reduction mechanism 25. The reduction mechanism 25 reduces the rotation of the rotary shaft 24a of the electric motor 24 and outputs the reduced rotation to the shaft member 25b. The shaft member 25b rotates in a direction corresponding to the rotation direction of the rotary shaft 24a of the electric motor 24.

[0016] The linear motion conversion mechanism 26 is configured to convert the rotation of the shaft member 25b into linear motion and output it to the friction materials 23. For example, the linear motion conversion mechanism 26 includes a screw member 26a connected to the shaft member 25b and a piston 26b. The outer peripheral surface of the screw member 26a is externally threaded, while the inner peripheral surface of the piston 26b is internally threaded. That is, the outer peripheral surface of the screw member 26a is externally threaded, and the inner peripheral surface of the piston 26b is internally threaded, into which the external thread of the screw member 26a is threaded. Therefore, when the shaft member 25b and the screw member 26a rotate, the piston 26b moves linearly. When the electric motor 24 is driven forward, the piston 26b moves in the first axle direction X1. Therefore, each friction material 23 moves relatively closer to the brake disc 21. On the other hand, when the electric motor 24 is driven backward, the piston 26b moves in the second axle direction X2. That is, when the electric motor 24 is driven to rotate the rotary shaft 24a in the braking force increasing direction Y1, the braking force of the vehicle is increased. On the other hand, when the electric motor 24 is driven to rotate the rotary shaft 24a in the braking force decreasing direction Y2, the braking force of the vehicle is decreased. Therefore, it can be said that the braking force increasing direction Y1 is the rotation direction when the braking force increases, and the braking force decreasing direction Y2 is the rotation direction when the braking force decreases. It can also be said that the braking device 20 is a device that applies braking force to the vehicle using the electric motor 24 as a power source.

[0017] The braking device 20 includes a locking device 30 that maintains the braking force of the vehicle. The locking device 30 maintains the braking force by restricting the rotation of the rotary shaft 24a of the electric motor 24 in the braking force reducing direction Y2.

[0018] <Configuration of locking device 30> 1 and 2, the locking device 30 includes a rotating member 31 fixed to the rotating shaft 24a. That is, the rotating member 31 rotates in accordance with the rotation of the rotating shaft 24a. In other words, the rotating member 31 is rotationally driven by the electric motor 24.

[0019] The rotating member 31 has a plate shape. For example, the rotating member 31 has a generally disk shape. In this embodiment, the rotating shaft 24a passes through the center of the rotating member 31. Therefore, the rotation center of the rotating member 31 is located on the central axis of the rotating shaft 24a. Therefore, when the braking force is to be increased, the rotating member 31 rotates in a braking force increasing direction Y1, and when the braking force is to be decreased, the rotating member 31 rotates in a braking force decreasing direction Y2.

[0020] A plurality of protrusions 31a are provided along the circumferential direction on the peripheral surface 311 of the rotating member 31. In this embodiment, the plurality of protrusions 31a are provided at equal intervals around the entire circumference of the peripheral surface 311. In other words, the rotating member 31 can also be said to be an external gear. It can also be said that a plurality of recesses 31b are formed on the rotating member 31 by the protrusions 31a adjacent to each other in the circumferential direction.

[0021] The locking device 30 includes a guide member 33. The guide member 33 is supported immovably relative to the housing of the brake caliper 22. The guide member 33 is disposed apart from the rotating member 31. In other words, a gap SP is present between the guide member 33 and the rotating member 31, and the guide member 33 does not come into contact with the rotating member 31.

[0022] In this embodiment, the guide member 33 is located outside the rotation member 31 in the radial direction centered on the central axis AX of the rotation member 31. That is, the guide member 33 is disposed facing the rotation member 31, outside the rotational radial direction of the rotation member 31. Therefore, a gap SP is present between the guide member 33 and the peripheral surface 311 of the rotation member 31.

[0023] The guide member 33 extends generally in the braking force reducing direction Y2. The guide member 33 has a guide surface 331. The guide surface 331 has a portion that faces the circumferential surface 311 of the rotating member 31 with the gap SP therebetween. In this embodiment, the guide surface 331 has a portion that gradually narrows the gap between the guide member 33 and the rotating member 31 in the braking force reducing direction Y2. In other words, the guide surface 331 has a portion where the linear distance from the central axis AX of the rotating member 31 to the guide surface 331 becomes shorter in the braking force reducing direction Y2. Therefore, the guide member 33 is provided so that the gap between the guide member 33 and the rotating member 31 becomes narrower in the braking force reducing direction Y2.

[0024] 2 and 3, the locking device 30 includes a locking member 35. The locking member 35 is disposed between the rotating member 31 and the guide member 33. The locking member 35 is provided in the housing of the brake caliper 22 in a state in which it can move in an advancing direction Z1 and a retracting direction Z2, which is the opposite direction to the advancing direction Z1.

[0025] For example, the locking device 30 includes a support shaft 37 that extends in the same direction as the rotating shaft 24a, and an arm 39 that is supported by the support shaft 37 in a swingable state. One of the two ends of the arm 39 is a first end 391, and the other is a second end 392. In this case, the linear distance from the first end 391 to the second end 392 is longer than the diameter of the rotating member 31.

[0026] A first end 391 of the arm 39 is supported by the support shaft 37, and a second end 392 of the arm 39 supports the locking member 35. The arm 39 supports the locking member 35 via a pin 41 that extends in the same direction as the support shaft 37. Therefore, the locking member 35 is able to swing freely around the pin 41. In the example shown in Figures 2 and 3, the clockwise direction in Figure 2 corresponds to the advancement direction Z1, and the counterclockwise direction in Figure 2 corresponds to the retraction direction Z2.

[0027] The locking device 30 includes a first biasing member 43 that biases the locking member 35 in the retracting direction Z2. In the locking device 30 shown in Figures 2 and 3, the first biasing member 43 applies a biasing force to the arm 39, thereby biasing the locking member 35 in the retracting direction Z2.

[0028] The locking member 35 can be in a retracted state shown in FIG. 2 and a clamped state shown in FIG. 3. The retracted state is a state in which the locking member 35 is not clamped between the rotating member 31 and the guide member 33, as shown in FIG. 2. In the retracted state, the locking member 35 is not in contact with at least one of the rotating member 31 and the guide member 33. However, if the locking member 35 is in contact with the rotating member 31, the locking member 35 may become caught in the rotation of the rotating member 31, resulting in unintended locking. Therefore, in the retracted state, it is desirable that the locking member 35 not be in contact with the rotating member 31, as shown in FIG. 2.

[0029] On the other hand, the clamped state is a state in which the locking member 35 is clamped between the rotating member 31 and the guide member 33, as shown in Fig. 3. When the locking member 35 is in the clamped state, the locking member 35 contacts both the circumferential surface 311 of the rotating member 31 and the guide surface 331.

[0030] In this embodiment, the position of the locking member 35 when it is in the retracted state is referred to as the "retracted position." Also, the position of the locking member 35 when it is in the clamping state is referred to as the "clamping position."

[0031] When the locking member 35, which is in the retracted state, is moved in the advance direction Z1, the locking member 35 enters the clamping state. That is, the locking member 35 is positioned at the clamping position. On the other hand, when the locking member 35, which is in the clamping state, is moved in the retraction direction Z2, the locking member 35 enters the retracted state. That is, the locking member 35 is positioned at the retracted position. In other words, the movement direction of the locking member 35 to place the locking member 35 at the clamping position is the advance direction Z1, and the movement direction of the locking member 35 to place the locking member 35 at the retracted position is the retraction direction Z2. Therefore, when the direction in which the locking member 35 moves from the clamping position to the retracted position is defined as the "predetermined direction," the retraction direction Z2 corresponds to the "predetermined direction."

[0032] The locking member 35 has a first surface 351 facing the circumferential surface 311 of the rotating member 31 and a second surface 352 facing the guide surface 331. Of both ends of the locking member 35, the end located in the retraction direction Z2 is referred to as a base end 353, and the end located in the advancement direction Z1 is referred to as a tip end 354. When the distance between the first surface 351 and the second surface 352 is the width of the locking member 35 between the rotating member 31 and the guide member 33, the width of the locking member 35 between the rotating member 31 and the guide member 33 increases in the retraction direction Z2. In this embodiment, the base end 353 is supported by the arm 39.

[0033] A first surface 351 of the locking member 35 is provided with a plurality of recesses 35a along the longitudinal direction of the locking member 35. The recesses 35a are arranged at equal intervals. When the locking member 35 is in the clamped state, the protrusions 31a of the rotating member 31 are fitted into the respective recesses 35a. In other words, when the plurality of protrusions 31a are fitted into the plurality of recesses 35a, respectively, the protrusions 35b between adjacent recesses 35a can be engaged with the protrusions 31a of the rotating member 31. In this case, it can also be said that the protrusions 35b of the locking member 35 are fitted into the recesses 31b between adjacent protrusions 31a of the rotating member 31.

[0034] The locking device 30 includes an actuator 50 supported by a housing of the brake caliper 22. The actuator 50 has an electromagnetic solenoid 51. The electromagnetic solenoid 51 has a shaft member 52 that moves forward and backward, and an electromagnetic coil 53. The shaft member 52 is displaced in a direction toward a base end 353 of the locking member 35 and a direction away from the base end 353. When current is applied to the electromagnetic coil 53, the shaft member 52 approaches the locking member 35 by electromagnetic force and comes into contact with the base end 353. The shaft member 52 then pushes the locking member 35, causing the locking member 35 to move in the advancing direction Z1.

[0035] The actuator 50 has a second biasing member 55 that biases the shaft member 52 in a direction that moves it away from the locking member 35. Therefore, when the electromagnetic coil 53 is de-energized, the biasing force of the second biasing member 55 moves the shaft member 52 in a direction that moves it away from the locking member 35. In other words, the state in which the shaft member 52 presses the locking member 35 is released. As a result, the locking member 35 is allowed to move in the retraction direction Z2. In this embodiment, the actuator 50, the support shaft 37, the arm 39, and the first biasing member 43 constitute an example of a moving device 100 that moves the locking member 35 between the clamping position and the retracted position.

[0036] <Control device 60> 1, the braking device 20 includes a control device 60. The control device 60 controls the electric motor 24 and the actuator 50. That is, the control device 60 controls the electric motor 24 and the actuator 50 to adjust the braking force of the vehicle.

[0037] Such a control device 60 may be configured as a circuit including one or more processors operating according to a computer program, one or more dedicated hardware circuits such as dedicated hardware for performing at least some of the various processes, or a combination thereof. Dedicated hardware can include, for example, an application-specific integrated circuit (ASIC). The processor includes a CPU and memory such as RAM and ROM, which stores program code or instructions configured to cause the CPU to perform processes. The memory, i.e., storage medium, includes any available medium accessible by a general-purpose or dedicated computer.

[0038] <Actions and Effects of the Present Embodiment> First, with reference to FIGS. 2 to 5, a case where a braking force is applied to the vehicle and then the braking force is maintained will be described.

[0039] When no braking force is being applied to the vehicle, the electromagnetic coil 53 of the actuator 50 is de-energized. Therefore, in the locking device 30, the locking member 35 is in a retracted state as shown in FIG. 2. That is, the locking member 35 is in the retracted position. When the electric motor 24 is driven forward under the control of the control device 60 in this state, the rotating shaft 24a rotates in the braking force increasing direction Y1. As a result, the friction materials 23 move relatively closer to the brake disc 21. When the friction materials 23 begin to clamp the brake disc 21, the application of braking force to the vehicle begins. By increasing the force with which the friction materials 23 clamp the brake disc 21, the braking force of the vehicle increases.

[0040] When the braking force is to be maintained, the control device 60 controls the electric motor 24 to maintain the rotation angle of the rotary shaft 24a. Next, the control device 60 controls the start of energizing the electromagnetic coil 53 of the actuator 50. Then, as shown in FIG. 3 , the shaft member 52 of the actuator 50 moves, and the shaft member 52 pushes the base end 353 of the locking member 35, which is in the retracted state. This causes the locking member 35 to move in the advancing direction Z1. In other words, the locking member 35 moves from the retracted position toward the clamping position. In this respect, in this embodiment, the shaft member 52 corresponds to a "displacement member" that displaces when the locking member 35, which is in the retracted state, moves in the advancing direction Z1.

[0041] When the locking member 35 moves in the advancing direction Z1, the locking member 35 enters a clamping state as shown in FIGS. 3 and 4 . That is, the locking member 35 is positioned at the clamping position. When the locking member 35 is positioned at the clamping position, the electric motor 24 is de-energized. Then, a reaction force against the force of each friction material 23 clamping the brake disc 21 is transmitted to the reduction mechanism 25 via the linear motion conversion mechanism 26. As a result, the rotating shaft 24a of the electric motor 24 and the rotating member 31 rotate in the braking force reducing direction Y2 as shown by the hollow arrow A1 in FIG. 5 . Then, as shown by the hollow arrow A2 in FIG. 5 , this rotation of the rotating member 31 retracts the locking member 35. That is, the locking member 35 is displaced in a direction corresponding to the braking force reducing direction Y2. When the locking member 35 is displaced in this manner, a clamping force, which is a force clamping the locking member 35 between the rotating member 31 and the guide member 33, increases. In other words, when the rotation member 31 is rotated in the braking force decreasing direction Y2 with the lock member 35 in the clamping position, the lock member 35 is clamped between the rotation member 31 and the guide member 33. As a result, the clamping force increases.

[0042] In this embodiment, a portion is formed in which the gap between the guide member 33 and the rotating member 31 narrows as the gap approaches the braking force decreasing direction Y2. Therefore, by rotating the rotating member 31 in the braking force decreasing direction Y2 to retract the locking member 35, the clamping force can be increased.

[0043] The locking member 35 also has a portion where the distance between the first surface 351 and the second surface 352 becomes wider toward the base end 353. Therefore, by rotating the rotating member 31 in the braking force decreasing direction Y2 to retract the locking member 35, the clamping force can be increased.

[0044] The greater the clamping force, the greater the force pressing the first surface 351 of the locking member 35 against the circumferential surface 311 of the rotating member 31. When the force pressing the first surface 351 against the circumferential surface 311 of the rotating member 31 increases, the engagement force generated between the rotating member 31 and the locking member 35 increases.

[0045] Therefore, by increasing the clamping force by rotating the rotating member 31 in the braking force decreasing direction Y2, the engagement force generated between the rotating member 31 and the locking member 35 increases. As a result, further rotation of the rotating member 31 in the braking force decreasing direction Y2 is stopped by the locking member 35. This maintains the braking force.

[0046] That is, in this embodiment, since the braking force can be maintained by increasing the clamping force, it is not necessary to employ a member with a complex shape as the rotating member 31. In this embodiment, when the rotation of the rotating member 31 in the braking force reducing direction Y2 is stopped by the locking member 35, the multiple convex portions 31a of the rotating member 31 are fitted into the multiple concave portions 35a of the locking member 35. In this case, the convex portions 35b between adjacent concave portions 35a of the locking member 35 engage with the convex portions 31a of the rotating member 31. In other words, the locking member 35 can restrict the rotation of the rotating member 31 in the braking force reducing direction Y2 at multiple locations.

[0047] When further rotation of the rotating member 31 in the braking force decreasing direction Y2 is stopped, the supply of electricity to the electromagnetic coil 53 of the actuator 50 is stopped. Then, the biasing force of the second biasing member 55 causes the shaft member 52 of the actuator 50 to move away from the locking member 35. However, because the locking member 35 is sandwiched between the rotating member 31 and the guide member 33, even if the biasing force of the first biasing member 43 is transmitted to the locking member 35 via the arm 39, the displacement of the locking member 35 in the retraction direction Z2 is restricted. Therefore, even when the supply of electricity to the electric motor 24 and the actuator 50 is stopped, the braking force can be maintained.

[0048] Next, with reference to FIGS. 2 and 6, a case where the state in which the braking force is maintained by the locking device 30 is released will be described. By driving the electric motor 24 forward, the rotating shaft 24a and the rotating member 31 rotate in the braking force increasing direction Y1, as indicated by the open arrow A3 in FIG. 6 . Then, following the rotation of the rotating member 31, the locking member 35 is displaced in a direction to reduce the clamping force, as indicated by the open arrow A4 in FIG. 6 . As the clamping force decreases due to the displacement of the locking member 35, the engagement force between the rotating member 31 and the locking member 35 decreases. When the engagement force decreases, the biasing force of the first biasing member 43 causes the locking member 35 to begin moving in the retracting direction Z2, as shown in FIG. 6 . As a result, the locking member 35, which was in the clamping state as shown in FIG. 2 , enters the retracted state. This releases the braking force, allowing the rotating shaft 24a and the rotating member 31 to rotate in the braking force decreasing direction Y2. In this state, when the electric motor 24 is driven in the reverse direction under the control of the control device 60, the friction materials 23 move away from the brake discs 21. As a result, the state in which the braking force is applied to the vehicle is released.

[0049] (Second embodiment) A second embodiment of the braking device will be described with reference to Figure 7. The second embodiment differs from the first embodiment in that it is provided with a function to limit excessive insertion of the locking member 35. In the following explanation, differences from the first embodiment will be mainly described, and components that are the same as or equivalent to those in the first embodiment will be given the same reference numerals and redundant explanations will be omitted.

[0050] 7, of the ends of the guide member 33, the end farther from the actuator 50 is referred to as a first end 332, and the end closer to the actuator 50 is referred to as a second end 333. A limiting wall 34 is provided at the first end 332 of the guide member 33. The limiting wall 34 protrudes from the first end 332 of the guide member 33 toward the rotating member 31. Therefore, the limiting wall 34 can come into contact with a tip end 354 of the locking member 35. When the tip end 354 comes into contact with the limiting wall 34, displacement of the locking member 35 in a direction corresponding to the braking force reducing direction Y2 is restricted.

[0051] In other words, if the position of the locking member 35 when the tip portion 354 is in contact with the limiting wall 34 is defined as the "prescribed position," the limiting wall 34 restricts the locking member 35 from being displaced beyond the prescribed position in a direction corresponding to the braking force reduction direction Y2. In other words, the limiting wall 34 can be said to restrict the amount of movement of the locking member 35 when the locking member 35 moves while being sandwiched between the rotating member 31 and the guide member 33 due to rotation of the rotating member 31 in the braking force reduction direction Y2. Therefore, the limiting wall 34 corresponds to the "restricting portion."

[0052] <Actions and Effects of the Present Embodiment> When the rotation member 31 rotates in the braking force reducing direction Y2 with the locking member 35 in the clamping position, the locking member 35 is displaced in a direction corresponding to the braking force reducing direction Y2. That is, the locking member 35 is retracted.

[0053] As the locking member 35 is displaced in this manner, the clamping force with which the locking member 35 is clamped between the rotating member 31 and the guide member 33 increases. However, if the clamping force becomes too large, there is a risk that the load applied to the locking member 35 due to clamping the locking member 35 between the rotating member 31 and the guide member 33 will become excessive. Furthermore, if the clamping force is too large, when an attempt is made to release the clamped state of the locking member 35 by rotating the rotating member 31 in the braking force increasing direction Y1, there is a risk that the displacement of the locking member 35 linked to the rotation of the rotating member 31 in the braking force increasing direction Y1 will not be realized. In this case, there is a risk that the locking member 35 will not be able to be put into the retracted state.

[0054] In this regard, in this embodiment, by providing the limiting wall 34, it is possible to prevent the locking member 35 from being inserted too far. As a result, it is possible to prevent the clamping force from becoming excessive. Therefore, it is possible to prevent the load applied to the locking member 35 from becoming excessive when the locking member 35 is clamped between the rotating member 31 and the guide member 33. Furthermore, it is possible to prevent the clamped state of the locking member 35 from being unable to be released when an attempt is made to release the clamped state of the locking member 35 by rotating the rotating member 31 in the braking force increasing direction Y1.

[0055] (Third embodiment) A third embodiment of a braking device will be described with reference to Figure 8. The third embodiment differs from the above-described embodiments in the configuration of the actuator and in that a locking member is connected to the actuator. In the following description, differences from the above-described embodiments will be mainly described, and components that are the same as or equivalent to those in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0056] As shown in Fig. 8, the actuator 50A includes a linear motion member 52A. The linear motion member 52A is movable forward and backward in its extension direction. The actuator 50A is capable of moving the linear motion member 52A in a first linear motion direction D1 and a second linear motion direction D2, which is the opposite direction to the first linear motion direction D1. That is, when the actuator 50A is driven forward, the linear motion member 52A moves in the first linear motion direction D1. On the other hand, when the actuator 50A is driven backward, the linear motion member 52A moves in the second linear motion direction D2.

[0057] The first linear motion direction D1 is the direction in which the linear motion member 52A moves when moving the locking member 35 in the advancing direction Z1, while the second linear motion direction D2 is the direction in which the linear motion member 52A moves when moving the locking member 35 in the retracting direction Z2.

[0058] In this embodiment, the actuator 50A is configured so that the position of the linearly moving member 52A is maintained when the supply of electricity to the actuator 50A is stopped. A first end of a flexible member 57 is connected to a tip end 521A of the linear motion member 52A, and a base end portion 353 of the locking member 35 is connected to a second end of the flexible member 57. In other words, the locking member 35 is connected to the linear motion member 52A via the flexible member 57.

[0059] The flexible member 57 is configured to be freely deformable. That is, the flexible member 57 allows the locking member 35 to be displaced relative to the linear motion member 52A by its own deformation. For example, a flexible joint or a coil spring can be used as the flexible member 57.

[0060] <Actions and Effects of the Present Embodiment> In this embodiment, the locking member 35 is connected to a linear motion member 52A, which is a component of the actuator 50A, via a flexible member 57. Therefore, the locking member 35 can be placed in a retracted state or a clamped state by moving the linear motion member 52A. Therefore, the locking device 30 can omit the support shaft 37, the arm 39, and the first biasing member 43.

[0061] Furthermore, the flexible member 57 connecting the linear motion member 52A and the locking member 35 is deformable. As a result, the actuator 50A can support the locking member 35 so that the locking member 35 can be displaced relative to the linear motion member 52A. In this embodiment, the linear motion member 52A corresponds to the "displacement member."

[0062] Incidentally, the actuator 50A may be replaced with the actuator 50. In this case, the supply of electricity to the electromagnetic coil 53 of the actuator 50 is stopped while the locking member 35 restricts the rotation of the rotating member 31 in the braking force reducing direction Y2. In this state, the clamping force that clamps the locking member 35 between the rotating member 31 and the guide member 33 is large, so that the movement of the shaft member 52 of the actuator 50 and the locking member 35 connected to the shaft member 52 in the retracting direction Z2 can be restricted.

[0063] (Fourth embodiment) A fourth embodiment of the braking device will be described with reference to Figures 9 and 10. In the following description, differences from the above-described embodiments will be mainly described, and the same reference numerals will be used to designate the same or corresponding components as those in the above-described embodiments, and redundant description will be omitted.

[0064] The locking device 30A will be described with reference to Figures 9 and 10. Figure 10 is a schematic cross-sectional view of the electric motor 24A and the locking device 30A shown in Figure 9 taken along line 10-10.

[0065] The electric motor 24A includes a case 70 that rotates integrally with the rotary shaft 24aA. In this embodiment, the case 70 corresponds to the "rotating member." The case 70 has a cylindrical portion 71, a first lid portion 72 that closes a first end of the cylindrical portion 71, and a second lid portion 73 that closes a second end of the cylindrical portion 71. A surface 721 of the first lid portion 72 and a surface 731 of the second lid portion 73 are planes that are perpendicular to the rotary shaft 24aA.

[0066] Locking device 30A includes guide member 33A that is arranged so that a gap is present between it and first cover part 72. More specifically, a gap is present between surface 721 of first cover part 72 and guide member 33A.

[0067] The locking device 30A includes a locking member 35A that is movable in an advancing direction Z1A and a retreating direction Z2A. The retreating direction Z2A is the opposite direction to the advancing direction Z1A. The advancing direction Z1A and the retreating direction Z2A are directions that are perpendicular to the extension direction of the rotation shaft 24aA.

[0068] The locking member 35A can be in a clamped state where it is clamped between the first cover portion 72 and the guide member 33A, and in a retracted state where it is not clamped between the first cover portion 72 and the guide member 33A. The position of the locking member 35A in the clamped state is the clamped position. The position of the locking member 35A in the retracted state is the retracted position. When the locking member 35A is in the retracted state, the locking member 35A does not come into contact with the case 70. In other words, the locking member 35A does not prevent the case 70 from rotating.

[0069] On the other hand, when the locking member 35A is in the clamped state as shown in Figures 9 and 10, the locking member 35A comes into contact with both the surface 721 of the first lid part 72 and the guide surface 331A of the guide member 33A.

[0070] The locking device 30A has a moving device 100B that moves the locking member 35 between a retracted position and a clamping position. The moving device 100B has an actuator 50B. By operating the actuator 50B, the guide member 33A, which was in the retracted state, can be moved in the advancing direction Z1A, and the guide member 33A can be placed in the clamping state. By operating the actuator 50B, the guide member 33A, which was in the clamping state, can be moved in the retracting direction Z2A, and the guide member 33A can be placed in the retracted state.

[0071] <Actions and Effects of the Present Embodiment> When the electric motor 24A is driven forward, the braking force of the vehicle increases. To maintain the braking force, the actuator 50B is driven while the rotational angles of the rotary shaft 24aA and the case 70 are maintained, thereby clamping the guide member 33A, which was in the retracted state. When the electric motor 24A is de-energized, the rotary shaft 24aA and the case 70 rotate in the braking force reduction direction Y2. The rotation of the case 70 then displaces the guide member 33A in a direction corresponding to the braking force reduction direction Y2. As a result, the force clamping the guide member 33A between the case 70 and the guide member 33A increases. This stops further rotation of the case 70 and the rotary shaft 24aA in the braking force reduction direction Y2. Therefore, the braking force can be maintained.

[0072] (Example of change) The above-described embodiments can be modified as follows: The above-described embodiments and the following modifications can be combined with each other within the scope of technical compatibility.

[0073] In the first, second, and third embodiments, the locking member 35 does not have to be provided with the recess 35a into which the protrusion 31a provided on the rotating member 31 can be fitted. In this case, the locking member 35 may be made of an elastic body so that the locking member 35 elastically deforms when the protrusion 31a comes into contact with the first surface 351 of the locking member 35, for example.

[0074] In the first, second, and third embodiments, the protrusion 31a does not have to be provided on the rotation member 31. Even in this case, by increasing the clamping force that clamps the locking member 35 between the rotation member 31 and the guide member 33, further rotation of the rotation member 31 in the braking force decreasing direction Y2 can be restricted.

[0075] In the second embodiment, it is not necessary to provide the limiting wall 34. Even in this case, by providing a portion between the rotating member 31 and the guide member 33 through which the guide member 33 cannot pass, it is possible to limit the displacement of the locking member 35 beyond the specified position in the direction corresponding to the braking force reducing direction Y2.

[0076] Furthermore, by providing the guide member 33 with a portion that cannot pass through the gap SP between the rotating member 31 and the guide member 33, it is possible to restrict the locking member 35 from being displaced beyond a specified position in a direction corresponding to the braking force reduction direction Y2.

[0077] In the first, second, and third embodiments, the locking member 35 does not necessarily have to have a portion where the distance between the first surface 351 and the second surface 352 becomes wider toward the base end 353.

[0078] In the first, second and third embodiments, the guide surface 331 does not have to have a portion where the distance between the guide member 33 and the rotating member 31 becomes shorter as it moves in the braking force decreasing direction Y2.

[0079] The locking device 30 may have a structure as shown in FIG. 11. An actuator 50B of the locking device 30 includes an electromagnetic solenoid 51. The electromagnetic solenoid 51 has a shaft member 52B that moves back and forth when an electromagnetic coil 53 is energized. A locking member 35 is connected to the shaft member 52B in a swingable manner. For example, the shaft member 52 supports the locking member 35 via a pin 41A. The pin 41A extends in the same direction as the rotating shaft 24a of the electric motor 24. The pin 41A is fixed to the tip of the shaft member 52. Meanwhile, the pin 41A supports the locking member 35 in a swingable manner in the direction indicated by the arrow in FIG. 11.

[0080] With the locking member 35 restricting the rotation of the rotating member 31 in the braking force decreasing direction Y2, the supply of electricity to the electromagnetic coil 53 of the actuator 50 is stopped. In this state, the clamping force that clamps the locking member 35 between the rotating member 31 and the guide member 33 is large, so movement of the shaft member 52B and the locking member 35 connected to the shaft member 52B in the retracting direction Z2 can be restricted. In other words, the braking force can be maintained.

[0081] In the first, second, and third embodiments, multiple gears 25a may be used as the rotating member. This eliminates the need to provide a rotating member 31 separately from the multiple gears 25a, thereby enabling the braking device to be made more compact. Note that when multiple gears 25a are used as the rotating member, using the portion of the electric motor 24 before the rotation is decelerated as the rotating member is preferable because the torque is smaller and it is easier to stop the rotation of the rotating member than when using the portion of the electric motor 24 after the rotation is decelerated as the rotating member.

[0082] In the first, second, and third embodiments, the rotating member 31 may be attached to a member other than the rotating shaft 24a as long as the member rotates in response to the rotation of the electric motor 24. For example, the rotating member 31 may be attached to the shaft member 25b.

[0083] The braking device may have a configuration other than the braking device 20 shown in FIG. 1 . For example, the braking device may be a device equipped with an electric cylinder that generates hydraulic pressure in response to the drive of an electric motor. If the rotation of the rotating member that rotates in response to the drive of the electric motor in the direction of decreasing the braking force is restricted by a locking member, the movement of the piston in the direction of increasing the volume of the cylinder chamber of the electric cylinder can be restricted. This makes it possible to maintain hydraulic pressure, and ultimately the braking force of the vehicle. [Explanation of symbols]

[0084] 20…braking device 24,24A...electric motor 24a, 24Aa...Rotation shaft 31...Rotating member 311...peripheral surface 31a, 35b...Convex part 31b, 35a...recess 33, 33A...Guide member 331, 331A...Guide surface 34...Restriction wall (an example of a restriction part) 35, 35A...locking member 351...Side 1 352…Second side 353...Proximal end 354...Tip 50, 50A, 50B... Actuator 52, 52B... Shaft member (an example of a displacement member) 52A... Linear motion member (an example of a displacement member) 70...Case (an example of a rotating member) 100,100B…Mobile device SP…Gap

Claims

1. A braking device that applies braking force to a vehicle using an electric motor as a power source, a rotating member that is rotationally driven by the electric motor and that rotates in a braking force increasing direction, which is a rotation direction when the braking force increases, and in a braking force decreasing direction, which is a rotation direction when the braking force decreases; a guide member disposed apart from the rotating member; a locking member configured to be movable between a clamping position where the locking member is clamped between the rotating member and the guide member when the rotating member rotates, and a retracted position where the locking member is not clamped between the rotating member and the guide member even when the rotating member rotates; a moving device that moves the locking member between the clamping position and the retracted position, When the rotating member is rotated in the braking force reducing direction with the locking member positioned at the clamping position, the locking member is clamped between the rotating member and the guide member, and the clamping force between the rotating member and the guide member increases, thereby stopping further rotation of the rotating member in the braking force reducing direction, the guide member is disposed radially outward of the rotating member so as to face the rotating member, and the distance between the guide member and the rotating member is narrowed in the braking force reducing direction, When the locking member is located at the clamping position, the locking member is located between the rotating member and the guide member on the outer side in the rotational radial direction of the rotating member, and the locking member comes into contact with both the rotating member and the guide member. Braking device.

2. A braking device that applies braking force to a vehicle using an electric motor as a power source, a rotating member that is rotationally driven by the electric motor and that rotates in a braking force increasing direction, which is a rotation direction when the braking force increases, and in a braking force decreasing direction, which is a rotation direction when the braking force decreases; a guide member disposed apart from the rotating member; a locking member configured to be movable between a clamping position where the locking member is clamped between the rotating member and the guide member when the rotating member rotates, and a retracted position where the locking member is not clamped between the rotating member and the guide member even when the rotating member rotates; a moving device that moves the locking member between the clamping position and the retracted position, When the rotating member is rotated in the braking force reducing direction with the locking member positioned at the clamping position, the locking member is clamped between the rotating member and the guide member, and the clamping force between the rotating member and the guide member increases, thereby stopping further rotation of the rotating member in the braking force reducing direction, the guide member is disposed radially outward of the rotary member and facing the rotary member, When the locking member is located at the clamping position, the locking member is located between the rotating member and the guide member on the outer side in the rotational radial direction of the rotating member, and the locking member is in contact with both the rotating member and the guide member, When the direction in which the locking member moves from the clamping position to the retracted position is defined as a predetermined direction, the width of the locking member between the rotating member and the guide member increases in the predetermined direction. Braking device.

3. A braking device that applies braking force to a vehicle using an electric motor as a power source, a rotating member that is rotationally driven by the electric motor and that rotates in a braking force increasing direction, which is a rotation direction when the braking force increases, and in a braking force decreasing direction, which is a rotation direction when the braking force decreases; a guide member disposed apart from the rotating member; a locking member configured to be movable between a clamping position where the locking member is clamped between the rotating member and the guide member when the rotating member rotates, and a retracted position where the locking member is not clamped between the rotating member and the guide member even when the rotating member rotates; a moving device that moves the locking member between the clamping position and the retracted position, When the rotating member is rotated in the braking force reducing direction with the locking member positioned at the clamping position, the locking member is clamped between the rotating member and the guide member, and the clamping force between the rotating member and the guide member increases, thereby stopping further rotation of the rotating member in the braking force reducing direction, The braking device includes a limiting portion that limits the amount of movement of the locking member when the locking member moves while being sandwiched between the rotating member and the guide member due to rotation of the rotating member in the braking force reducing direction. Braking device.

4. A braking device that applies braking force to a vehicle using an electric motor as a power source, a rotating member that is rotationally driven by the electric motor and that rotates in a braking force increasing direction, which is a rotation direction when the braking force increases, and in a braking force decreasing direction, which is a rotation direction when the braking force decreases; a guide member disposed apart from the rotating member; a locking member configured to be movable between a clamping position where the locking member is clamped between the rotating member and the guide member when the rotating member rotates, and a retracted position where the locking member is not clamped between the rotating member and the guide member even when the rotating member rotates; a moving device that moves the locking member between the clamping position and the retracted position, When the rotating member is rotated in the braking force reducing direction with the locking member positioned at the clamping position, the locking member is clamped between the rotating member and the guide member, and the clamping force between the rotating member and the guide member increases, thereby stopping further rotation of the rotating member in the braking force reducing direction, the moving device includes an actuator that is activated by energization; the actuator has a displacement member that is displaced when current is applied to the actuator, The locking member is capable of being displaced relative to the displacement member. Braking device.

5. One of the rotating member and the locking member is provided with a convex portion, and the other is provided with a concave portion into which the convex portion can be fitted. The braking device according to any one of claims 1 to 4.

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