JP7548179B2 - Vehicle brake device - Google Patents

Description

The present invention relates to a vehicle brake device.

Conventionally, electric vehicle brake devices are known that convert the rotation of a rotating member driven by a motor into linear motion of a linear motion member, and the linear motion of the linear motion member presses pads against the wheel discs via pistons.

JP 2020-51596 A

For example, in the vehicle brake device of Patent Document 1, the linear motion member rotates relative to the piston when the rotating member rotates, and the rotation is restricted when the linear motion member abuts against a rotation limiting portion provided on the piston. When the rotation of the linear motion member is restricted by the rotation limiting portion, the linear motion member moves linearly. Here, when the rotation of the linear motion member is restricted, there is a risk of abnormal noise being generated due to the linear motion member abutting against the rotation limiting portion.

The object of the present invention is to provide a vehicle brake device that can suppress the generation of abnormal noise.

The first aspect of the present invention is a vehicle brake device capable of restricting the rotation of a wheel (2) by pressing a pad (4) against a disk (3) that is rotatably mounted together with the wheel, and includes a body (20), a cylinder (30), a piston (40), a motor (50), a rotary-linear motion conversion unit (600), and an engagement unit (90). The cylinder is provided in the body. The piston is housed in the cylinder and moves within the cylinder to press the pad against the disk. The motor has a rotor (51) that rotates when electricity is applied.

The rotary-linear motion conversion unit has a rotary member (60), a linear motion member (70), a forward rotation limiting unit (811), and a reverse rotation limiting unit (821). The rotary member rotates in conjunction with the rotation of the rotor. The linear motion member moves linearly in a first direction (D1) toward the pad in response to the forward rotation of the rotary member, and moves linearly in a second direction (D2) away from the pad in response to the reverse rotation of the rotary member. The forward rotation limiting unit is provided on the piston, and limits the forward rotation of the linear motion member when it abuts against the linear motion member. The reverse rotation limiting unit is provided on the piston, and limits the reverse rotation of the linear motion member when it abuts against the linear motion member.

The engagement portion has a first forward rotation engagement portion (91) and a first reverse rotation engagement portion (93), as well as a second forward rotation engagement portion (92) and a second reverse rotation engagement portion (94). The first forward rotation engagement portion and the first reverse rotation engagement portion are provided on the piston. The second forward rotation engagement portion and the second reverse rotation engagement portion are provided on the linear motion member. When the forward rotation of the linear motion member is restricted by the forward rotation restriction portion, the engagement portion is in a forward rotation engagement state in which the first forward rotation engagement portion and the second forward rotation engagement portion overlap in the axial direction of the piston. When the rotating member reverses from the forward rotation engagement state and the reverse rotation of the linear motion member is restricted by the reverse rotation restriction portion, the engagement portion is in a reverse rotation engagement state in which the first reverse rotation engagement portion and the second reverse rotation engagement portion overlap in the axial direction of the piston.

When in the forward rotation engagement state, the linear motion member moves linearly in a first direction toward the pad in response to the forward rotation of the rotating member, and the piston is biased in the first direction together with the rotation limiting portion and pressed against the pad. When in the reverse rotation engagement state, the linear motion member moves linearly in a second direction away from the pad in response to the reverse rotation of the rotating member, and the piston is biased in the second direction together with the rotation limiting portion and moves away from the pad. In this way, the engagement portion can improve the piston's ability to follow the linear motion of the linear motion member.

The first forward rotation engagement portion has a forward inclined surface (911) that is a surface inclined with respect to the axis of the piston. The first reverse rotation engagement portion has a reverse inclined surface (931) that is a surface inclined with respect to the axis of the piston. When the linear motion member abuts against the forward rotation limiting portion, the second forward rotation engagement portion moves along the forward inclined surface. When the linear motion member abuts against the reverse rotation limiting portion, the second reverse rotation engagement portion moves along the reverse inclined surface.

Therefore, the second forward rotation engagement portion of the linear motion member moves along the forward rotation inclined surface and abuts against the forward rotation limiting portion. Also, the second reverse rotation engagement portion of the linear motion member moves along the reverse rotation inclined surface and abuts against the reverse rotation limiting portion. As a result, when the second forward rotation engagement portion moves along the forward rotation inclined surface or when the second reverse rotation engagement portion moves along the reverse rotation inclined surface, the angular velocity of the relative rotation of the linear motion member with respect to the piston gradually decreases, and the linear motion member abuts against the forward rotation limiting portion or reverse rotation limiting portion at a relatively low angular velocity. Therefore, the impact when the linear motion member abuts against the forward rotation limiting portion or reverse rotation limiting portion can be mitigated, and the generation of abnormal noise can be suppressed.

The vehicle brake device of the second aspect of the present invention, like the first aspect, includes a body (20), a cylinder (30), a piston (40), a motor (50), a rotary-linear motion conversion unit (600), and an engagement unit (90). The forward rotation limiting unit has a forward rotation elastic member that is an elastic member that can abut against the second forward rotation engagement unit. The reverse rotation limiting unit has a reverse rotation elastic member (96) that is an elastic member that can abut against the second reverse rotation engagement unit.

Therefore, when the linear motion member abuts against the forward rotation limiting portion, the second forward rotation engaging portion abuts against the forward rotation elastic member. Also, when the linear motion member abuts against the reverse rotation limiting portion, the second reverse rotation engaging portion abuts against the reverse rotation elastic member. Therefore, the impact when the linear motion member abuts against the forward rotation limiting portion or the reverse rotation limiting portion can be mitigated, and the generation of abnormal noise can be suppressed.

1 is a cross-sectional view showing a vehicle brake device according to a first embodiment; 4 is a cross-sectional view showing a state in which forward rotation of a linear motion member of the vehicle brake device of the first embodiment is restricted; FIG. 4 is a cross-sectional view showing a state in which reverse rotation of a linear motion member of the vehicle brake device of the first embodiment is restricted; FIG. IV-IV line cross-sectional view of FIG. 2. 4 is a partial cross-sectional view showing a state in which a linear motion member of the vehicle brake device of the first embodiment abuts on a forward rotation limiting portion; FIG. 4 is a partial cross-sectional view showing a state in which a linear motion member of the vehicle brake device of the first embodiment abuts on a reverse rotation limiting portion; FIG. 2 is a cross-sectional view showing a piston and a rotation limiting portion of the vehicle brake device according to the first embodiment; FIG. 1 is a cross-sectional view showing a portion of a vehicle brake device according to a first embodiment; 13 is a cross-sectional view showing a state in which forward rotation of a linear motion member of a vehicle brake device of a comparative example is restricted; FIG. 13 is a cross-sectional view showing a state in which reverse rotation of a linear motion member of a vehicle brake device according to a comparative example is restricted; FIG. 13 is a cross-sectional view showing a piston and a rotation limiting portion of a vehicle brake device according to a comparative example. FIG. 4 is a diagram showing an example of operation of the vehicle brake device of the first embodiment, illustrating a change in angular velocity of a linearly moving member over time. FIG. 6 is a cross-sectional view showing a portion of a vehicle brake device according to a second embodiment. FIG. 11 is a cross-sectional view showing a portion of a vehicle brake device according to a third embodiment. FIG. 13 is a cross-sectional view showing a portion of a vehicle brake device according to a fourth embodiment.

Below, vehicle brake devices according to multiple embodiments will be described with reference to the drawings. Note that components that are essentially the same in multiple embodiments will be given the same reference numerals and descriptions will be omitted.

First Embodiment
A vehicle brake device of a first embodiment is shown in Fig. 1. The vehicle brake device 10 is provided, for example, on a wheel 2 of a vehicle 1. The vehicle brake device 10 can restrict the rotation of the wheel 2 by pressing a pad 4 against a disk 3 that is provided rotatably together with the wheel 2. This makes it possible to decelerate or stop the vehicle 1 while it is moving, or to maintain the vehicle 1 in a stopped state while it is stopped.

The vehicle brake device 10 includes a body 20, a cylinder 30, a piston 40, a motor 50, a rotary-linear motion conversion unit 600, an engagement unit 90, etc.

The cylinder 30 is provided in the body 20. The piston 40 is housed in the cylinder 30 and moves within the cylinder 30 to press the pad 4 against the disk 3. The motor 50 has a rotor 51 that rotates when electricity is applied.

More specifically, the body 20 is, for example, a caliper, and is provided on the vehicle 1. The body 20 is provided with pads 4 and 5. The pads 4 and 5 are provided on the body 20 so as to sandwich the outer edge of the disk 3 therebetween.

The cylinder 30 has a cylinder tube portion 31, a cylinder bottom portion 32, and a cylinder hole portion 33. The cylinder tube portion 31 is formed in a cylindrical shape. The cylinder bottom portion 32 is formed integrally with the cylinder tube portion 31 so as to close one end of the cylinder tube portion 31. The cylinder hole portion 33 is formed so as to penetrate the center of the cylinder bottom portion 32. The cylinder 30 is provided in the body 20 so that the end of the cylinder tube portion 31 opposite the cylinder bottom portion 32 faces the pad 4.

The piston 40 has a piston cylinder portion 41 and a piston bottom portion 42. The piston cylinder portion 41 is formed in a substantially cylindrical shape. The piston bottom portion 42 is formed integrally with the piston cylinder portion 41 so as to close one end of the piston cylinder portion 41. The surface of the piston bottom portion 42 facing the piston cylinder portion 41 is formed in a circular flat shape in the center, and the periphery is formed in a tapered surface shape. The piston 40 is housed inside the cylinder cylinder portion 31 so that the end of the piston cylinder portion 41 opposite the piston bottom portion 42 faces the cylinder bottom portion 32.

A seal member 11 is provided between the cylinder tube portion 31 and the piston tube portion 41. The seal member 11 is formed in an annular shape from an elastic material such as rubber. The seal member 11 is provided in an annular groove formed in the inner peripheral wall of the cylinder tube portion 31. The seal member 11 can maintain an airtight or liquidtight relationship between the cylinder tube portion 31 and the piston tube portion 41 by having the inner edge portion slidably contact the outer peripheral wall of the piston tube portion 41.

The piston 40 can reciprocate within the cylinder 30 in the direction of the axis Ax1 of the piston 40. This allows the piston bottom 42 to come into contact with the pad 4 and move away from the pad 4. When the piston 40 moves in a direction approaching the pad 4, it presses the pad 4 against the disk 3. This causes the outer edge of the disk 3 to be sandwiched between the pad 4 and the pad 5, restricting the rotation of the wheel 2.

The motor 50 has a rotor 51 and a motor shaft 52. The motor shaft 52 is provided at the center of rotation of the rotor 51 and can rotate together with the rotor 51. When electricity is applied to the motor 50, the rotor 51 rotates and torque is output from the motor shaft 52.

The motor 50 is controlled by an ECU (not shown). By controlling the supply of electricity to the motor 50, the ECU can control the operation of the motor 50 so that the rotor 51 rotates in the forward or reverse direction.

The rotary-linear motion conversion unit 600 has a rotary member 60, a linear motion member 70, a forward rotation limiting unit 811, and a reverse rotation limiting unit 821. The rotary member 60 rotates in conjunction with the rotation of the rotor 51. The linear motion member 70 moves linearly in a first direction D1 toward the pad 4 in response to the forward rotation of the rotary member 60, and moves linearly in a second direction D2 away from the pad 4 in response to the reverse rotation of the rotary member 60. The forward rotation limiting unit 811 is provided on the piston 40, and limits the forward rotation of the linear motion member 70 when it abuts against the linear motion member 70. The reverse rotation limiting unit 821 is provided on the piston 40, and limits the reverse rotation of the linear motion member 70 when it abuts against the linear motion member 70.

More specifically, the rotating member 60 has a rotating shaft portion 61 and a rotating flange portion 62. The rotating shaft portion 61 is formed, for example, in a cylindrical shape. A male thread portion 601 is formed in a part of the axial direction of the outer peripheral wall of the rotating shaft portion 61. The rotating flange portion 62 is formed in a substantially annular plate shape so as to protrude radially outward from the outer peripheral wall between one end of the rotating shaft portion 61 and the male thread portion 601. The rotating member 60 is provided in the cylinder 30 so that one end of the rotating shaft portion 61 is inserted into the cylinder hole portion 33, the rotating flange portion 62 is located inside the cylinder tube portion 31, and the other end side of the rotating shaft portion 61 is located inside the piston tube portion 41.

A thrust bearing 12 is provided between the rotating flange portion 62 and the cylinder bottom portion 32. The thrust bearing 12 rotatably supports the rotating member 60 while receiving a load in the thrust direction from the rotating flange portion 62.

The end of the cylinder 30 on the cylinder bottom 32 side is provided with a rotation transmission unit 500. The rotation transmission unit 500 has a reducer 53 and an output unit 54. The reducer 53 has, for example, multiple gears, and reduces and outputs the torque of the motor 50 output from the motor shaft 52. The output unit 54 is provided to connect the reducer 53 to one end of the rotating shaft unit 61. The output unit 54 outputs the torque of the motor 50 reduced by the reducer 53 to the rotating member 60. As a result, when the rotor 51 of the motor 50 rotates in the forward direction, the rotating member 60 rotates in the forward direction, and when the rotor 51 rotates in the reverse direction, the rotating member 60 rotates in the reverse direction. In this way, the rotating member 60 rotates in conjunction with the rotation of the rotor 51.

The linear motion member 70 has a linear motion tubular portion 71 and a linear motion flange portion 72. The linear motion tubular portion 71 is formed in a cylindrical shape. A female thread portion 701 that can be screwed into the male thread portion 601 is formed on the inner peripheral wall of the linear motion tubular portion 71. The outer edge portion of one end face of the linear motion tubular portion 71 is formed in a tapered surface shape. The linear motion flange portion 72 is formed so as to protrude radially outward from the outer peripheral wall on one end side of the linear motion tubular portion 71. Two linear motion flange portions 72 are formed at equal intervals in the circumferential direction of the linear motion tubular portion 71 (see Figures 1 to 3).

The linear motion member 70 is provided radially outside the rotating shaft portion 61 such that the female threaded portion 701 is screwed into the male threaded portion 601 of the rotating member 60, and one end of the linear motion cylinder portion 71 faces the piston bottom portion 42. When the rotating member 60 rotates in the forward rotation direction R1, the linear motion member 70 rotates in the forward rotation direction R1 together with the rotation of the rotating member 60 (see FIG. 2). When the rotating member 60 rotates in the reverse direction R2, the linear motion member 70 rotates in the reverse direction R2 together with the rotation of the rotating member 60 (see FIG. 3).

The piston 40 is provided with a rotation limiting portion 800. The rotation limiting portion 800 has a rotation limiting portion main body 80, a forward rotation limiting protrusion 81, and a reverse rotation limiting protrusion 82. The rotation limiting portion main body 80 is formed in a substantially cylindrical shape. The outer diameter of the rotation limiting portion main body 80 is set to be substantially the same as the inner diameter of the piston tube portion 41. The rotation limiting portion 800 is provided on the piston 40 so that the outer peripheral wall of the rotation limiting portion main body 80 faces the inner peripheral wall of the piston tube portion 41. Therefore, the rotation limiting portion 800 can rotate together with the piston 40.

The forward rotation limiting protrusions 81 are formed so as to protrude radially inward from the inner peripheral wall of the rotation limiting body 80 and extend in the axial direction of the rotation limiting body 80. Two forward rotation limiting protrusions 81 are formed at equal intervals in the circumferential direction of the rotation limiting body 80 (see Figures 2 and 3). Two reverse rotation limiting protrusions 82 are formed so as to protrude radially inward from the inner peripheral wall of the rotation limiting body 80 and extend in the axial direction of the rotation limiting body 80. Two reverse rotation limiting protrusions 82 are formed at equal intervals in the circumferential direction of the rotation limiting body 80 (see Figures 2 and 3). The forward rotation limiting protrusions 81 and the reverse rotation limiting protrusions 82 are alternately arranged at equal intervals in the circumferential direction of the rotation limiting body 80.

The forward rotation limiting portion 811 is formed on the forward rotation limiting protrusion 81 so as to face one circumferential side of the rotation limiting portion main body 80 (see Figures 1 to 7). The reverse rotation limiting portion 821 is formed on the reverse rotation limiting protrusion 82 so as to face the other circumferential side of the rotation limiting portion main body 80 (see Figures 1 to 7). Here, when viewed from the axial Ax1 direction of the piston 40, the linear motion member 70 is provided so that the linear motion flange portion 72 is located between the forward rotation limiting portion 811 and the reverse rotation limiting portion 821 in the circumferential direction of the rotation limiting portion main body 80 (see Figures 2 and 3).

When the forward rotation limiting portion 811 abuts against the linear flange portion 72 of the linear member 70, it limits the forward rotation of the linear member 70. When the reverse rotation limiting portion 821 abuts against the linear flange portion 72 of the linear member 70, it limits the reverse rotation of the linear member 70.

2, when the rotating member 60 rotates forward, i.e., in the forward direction R1, the linear motion member 70 also rotates forward, and the linear motion flange portion 72 abuts against the forward rotation limiting portion 811, the rotation of the linear motion member 70 in the forward direction, i.e., in the forward direction R1, is restricted. Because the male thread portion 601 and the female thread portion 701 are screwed together, when the rotating member 60 further rotates forward in a state in which the forward rotation of the linear motion member 70 is restricted, the linear motion member 70 moves relative to the rotating member 60 in the first direction D1, which is a direction toward the pad 4 (see FIG. 1). That is, the linear motion member 70 moves linearly in the first direction D1 toward the pad 4 in response to the forward rotation of the rotating member 60.

As shown in FIG. 3, when the rotating member 60 rotates in the reverse direction R2, the linear motion member 70 also rotates in the reverse direction, and the linear motion flange portion 72 abuts against the reverse motion limiting portion 821, the rotation of the linear motion member 70 in the reverse direction R2 is restricted. Since the male thread portion 601 and the female thread portion 701 are screwed together, when the rotating member 60 further rotates in the reverse direction while the reverse motion of the linear motion member 70 is restricted, the linear motion member 70 moves relative to the rotating member 60 in the second direction D2, which is a direction away from the pad 4 (see FIG. 1). That is, the linear motion member 70 moves linearly in the second direction D2, which moves away from the pad 4, in response to the reverse rotation of the rotating member 60.

In addition, since the outer peripheral wall of the piston cylinder portion 41 is in slidable contact with the seal member 11 and the piston bottom portion 42 can abut against the pad 4, the relative rotation of the piston 40 with respect to the cylinder 30 is restricted by friction with the seal member 11 or the pad 4. Therefore, the relative rotation of the rotation restriction portion 800 with respect to the cylinder 30 is also restricted.

The engagement portion 90 has a first forward rotation engagement portion 91 and a first reverse rotation engagement portion 93, as well as a second forward rotation engagement portion 92 and a second reverse rotation engagement portion 94. The first forward rotation engagement portion 91 and the first reverse rotation engagement portion 93 are provided on the piston 40. The second forward rotation engagement portion 92 and the second reverse rotation engagement portion 94 are provided on the linear motion member 70. When the forward rotation of the linear motion member 70 is restricted by the forward rotation restriction portion 811, the engagement portion 90 is in a forward rotation engagement state in which the first forward rotation engagement portion 91 and the second forward rotation engagement portion 92 overlap in the axial direction of the piston 40. When the rotating member 60 reverses from the forward rotation engagement state and the reverse rotation of the linear motion member 70 is restricted by the reverse rotation restriction portion 821, the engagement portion 90 is in a reverse rotation engagement state in which the first reverse rotation engagement portion 93 and the second reverse rotation engagement portion 94 overlap in the axial direction of the piston 40.

More specifically, the first forward rotation engagement portion 91 is formed on the forward rotation limiting protrusion 81 of the rotation limiting portion 800 provided on the piston 40. The first forward rotation engagement portion 91 is formed to face the side opposite the piston bottom portion 42 (see Figures 1 to 7). The first reverse rotation engagement portion 93 is formed on the reverse rotation limiting protrusion 82 of the rotation limiting portion 800 provided on the piston 40. The first reverse rotation engagement portion 93 is formed to face the piston bottom portion 42 (see Figures 1 to 7).

The second forward engagement portion 92 is formed at one circumferential end of the linear cylinder portion 71 of the linear flange portion 72. The second reverse engagement portion 94 is formed at the other circumferential end of the linear cylinder portion 71 of the linear flange portion 72 (see Figures 2 and 3).

2, when the forward rotation of the linear motion member 70 is restricted by the forward rotation restricting portion 811, the engagement portion 90 is in a forward rotation engagement state in which the first forward rotation engagement portion 91 and the second forward rotation engagement portion 92 overlap in the axial Ax1 direction of the piston 40. At this time, the first forward rotation engagement portion 91 and the second forward rotation engagement portion 92 abut, i.e., engage (see FIGS. 2, 4, and 5). Therefore, when the linear motion member 70 moves in the first direction D1 in response to the forward rotation of the rotating member 60 in the forward rotation engagement state, the piston 40 is biased in the first direction D1 together with the rotation restricting portion 800 and pressed against the pad 4. As a result, the pad 4 is pressed against the disc 3, the disc 3 is sandwiched between the pad 4 and the pad 5, and the rotation of the wheel 2 is restricted.

3, when the rotating member 60 rotates in the reverse direction from the forward rotation engagement state and the reverse rotation of the linear motion member 70 is restricted by the reverse rotation restriction portion 821, the engagement portion 90 is in a reverse rotation engagement state in which the first reverse rotation engagement portion 93 and the second reverse rotation engagement portion 94 overlap in the direction of the axis Ax1 of the piston 40. At this time, the first reverse rotation engagement portion 93 and the second reverse rotation engagement portion 94 abut, i.e., engage with each other (see FIGS. 3 and 6). Therefore, when the linear motion member 70 moves linearly in the second direction D2 away from the pad 4 in response to the reverse rotation of the rotating member 60 in the reverse rotation engagement state, the piston 40 is biased in the second direction D2 together with the rotation restriction portion 800 and moves away from the pad 4. This releases the pad 4 from being pressed against the disk 3, and the restriction on the rotation of the wheel 2 is released.

The first forward rotation engagement portion 91 has a forward inclined surface 911, which is a surface inclined with respect to the axis Ax1 of the piston 40. The first reverse rotation engagement portion 93 has a reverse rotation inclined surface 931, which is a surface inclined with respect to the axis Ax1 of the piston 40. When the linear motion member 70 abuts against the forward rotation limiting portion 811, the second forward rotation engagement portion 92 moves along the forward rotation inclined surface 911. When the linear motion member 70 abuts against the reverse rotation limiting portion 821, the second reverse rotation engagement portion 94 moves along the reverse rotation inclined surface 931.

More specifically, the forward inclined surface 911 is formed on the first forward engagement portion 91 so as to be inclined with respect to the axis Ax1 of the piston 40 (see Figures 4 to 7). The reverse inclined surface 931 is formed on the first reverse engagement portion 93 so as to be inclined with respect to the axis Ax1 of the piston 40 (see Figures 4 to 8).

As shown in FIG. 5, when the linear motion member 70 rotates in a direction in which it abuts against the forward rotation limiting portion 811, i.e., in the forward rotation direction R1, the second forward rotation engaging portion 92 moves along the forward rotation inclined surface 911. As a result, the second forward rotation engaging portion 92 abuts against the forward rotation limiting portion 811 (see FIG. 2).

As shown in FIG. 6, when the linear motion member 70 rotates in a direction in which it abuts against the reverse rotation limiting portion 821, i.e., in the reverse rotation direction R2, the second reverse rotation engaging portion 94 moves along the reverse rotation inclined surface 931. As a result, the second reverse rotation engaging portion 94 abuts against the reverse rotation limiting portion 821 (see FIG. 3).

<2> In this embodiment, when the linear motion member 70 abuts against the forward rotation limiting portion 811, the first abutment position Pt1, which is the position where the second forward rotation engagement portion 92 and the first forward rotation engagement portion 91 first abut, is between one end and the other end of the forward rotation inclined surface 911 in the axial Ax1 direction of the piston 40. When the linear motion member 70 abuts against the reverse rotation limiting portion 821, the second abutment position Pt2, which is the position where the second reverse rotation engagement portion 94 and the first reverse rotation engagement portion 93 first abut, is between one end and the other end of the reverse rotation inclined surface 931 in the axial Ax1 direction of the piston 40.

More specifically, as shown in FIG. 5, when the linear motion member 70 rotates in a direction in which it abuts against the forward rotation limiting portion 811, i.e., in the forward rotation direction R1, the second forward rotation engagement portion 92 first abuts against the forward rotation inclined surface 911 of the first forward rotation engagement portion 91 at the first abutment position Pt1. Also, as shown in FIG. 6, when the linear motion member 70 rotates in a direction in which it abuts against the reverse rotation limiting portion 821, i.e., in the reverse rotation direction R2, the second reverse rotation engagement portion 94 first abuts against the reverse rotation inclined surface 931 of the first reverse rotation engagement portion 93 at the second abutment position Pt2.

Here, the problems with the comparative embodiment will be described. The comparative embodiment differs from the present embodiment in that the first forward rotation engagement portion 91 does not have a forward rotation inclined surface 911, and the first reverse rotation engagement portion 93 does not have a reverse rotation inclined surface 931.

In the comparative embodiment, since the first forward rotation engagement portion 91 does not have a forward rotation inclined surface 911 (see FIGS. 9 to 11), when the linear motion member 70 rotates in a direction in which it abuts against the forward rotation limiting portion 811, i.e., in the forward rotation direction R1, the second forward rotation engagement portion 92 abuts against the forward rotation limiting portion 811 without a decrease in angular velocity (see FIG. 9). Therefore, there is a risk of abnormal noise being generated due to the impact when the second forward rotation engagement portion 92 abuts against the forward rotation limiting portion 811.

In addition, since the first reverse rotation engagement portion 93 does not have a reverse rotation inclined surface 931 (see Figures 9 to 11), when the linear motion member 70 rotates in a direction in which it abuts against the reverse rotation limiting portion 821, i.e., in the reverse rotation direction R2, the second reverse rotation engagement portion 94 abuts against the reverse rotation limiting portion 821 without a decrease in angular velocity (see Figure 10). Therefore, there is a risk of abnormal noise being generated due to the impact when the second reverse rotation engagement portion 94 abuts against the reverse rotation limiting portion 821.

On the other hand, in this embodiment, as described above, when the linear motion member 70 rotates in a direction in which it abuts against the forward rotation limiting portion 811, i.e., in the forward rotation direction R1, the second forward rotation engagement portion 92 first abuts against the forward rotation inclined surface 911 of the first forward rotation engagement portion 91 at the first abutment position Pt1, moves along the forward rotation inclined surface 911, and then abuts against the forward rotation limiting portion 811. Therefore, as shown in FIG. 12, the angular velocity of the linear motion member 70 gradually decreases after the second forward rotation engagement portion 92 abuts against the forward rotation inclined surface 911 at time t1, and becomes relatively low when the second forward rotation engagement portion 92 abuts against the forward rotation limiting portion 811 at time t2. As a result, the linear motion member 70 abuts against the forward rotation limiting portion 811 at a relatively low angular velocity. Therefore, the impact when the linear motion member 70 abuts against the forward rotation limiting portion 811 can be mitigated, and the generation of abnormal noise can be suppressed.

In addition, in this embodiment, as described above, when rotating in a direction to abut against the reverse rotation limiting portion 821, i.e., in the reverse rotation direction R2, the second reverse rotation engagement portion 94 first abuts against the reverse rotation inclined surface 931 of the first reverse rotation engagement portion 93 at the second abutment position Pt2, moves along the reverse rotation inclined surface 931, and then abuts against the reverse rotation limiting portion 821. This causes the linear motion member 70 to abut against the reverse rotation limiting portion 821 at a relatively low angular velocity. Therefore, the impact when the linear motion member 70 abuts against the reverse rotation limiting portion 821 can be mitigated, and the generation of abnormal noise can be suppressed.

As described above, in the present embodiment, <1> the engagement portion 90 has the first forward rotation engagement portion 91 and the first reverse rotation engagement portion 93, as well as the second forward rotation engagement portion 92 and the second reverse rotation engagement portion 94. The first forward rotation engagement portion 91 and the first reverse rotation engagement portion 93 are provided on the piston 40. The second forward rotation engagement portion 92 and the second reverse rotation engagement portion 94 are provided on the linear motion member 70. When the forward rotation of the linear motion member 70 is restricted by the forward rotation restriction portion 811, the engagement portion 90 is in a forward rotation engagement state in which the first forward rotation engagement portion 91 and the second forward rotation engagement portion 92 overlap in the axial direction of the piston 40. When the rotation member 60 rotates in reverse from the forward rotation engagement state and the reverse rotation of the linear motion member 70 is restricted by the reverse rotation restriction portion 821, the engagement portion 90 is in a reverse rotation engagement state in which the first reverse rotation engagement portion 93 and the second reverse rotation engagement portion 94 overlap in the axial direction of the piston 40.

When the linear member 70 moves linearly in a first direction D1 toward the pad 4 in response to the forward rotation of the rotating member 60 in the forward rotation engaged state, the piston 40 is urged in the first direction D1 together with the rotation limiting portion 800 and pressed against the pad 4. When the linear member 70 moves linearly in a second direction D2 away from the pad 4 in response to the reverse rotation of the rotating member 60 in the reverse rotation engaged state, the piston 40 is urged in the second direction D2 together with the rotation limiting portion 800 and moves away from the pad 4. In this way, the engagement portion 90 can improve the ability of the piston 40 to follow the linear movement of the linear member 70.

The first forward rotation engagement portion 91 has a forward inclined surface 911, which is a surface inclined with respect to the axis Ax1 of the piston 40. The first reverse rotation engagement portion 93 has a reverse rotation inclined surface 931, which is a surface inclined with respect to the axis Ax1 of the piston 40. When the linear motion member 70 abuts against the forward rotation limiting portion 811, the second forward rotation engagement portion 92 moves along the forward rotation inclined surface 911. When the linear motion member 70 abuts against the reverse rotation limiting portion 821, the second reverse rotation engagement portion 94 moves along the reverse rotation inclined surface 931.

Therefore, the second forward rotation engagement portion 92 of the linear motion member 70 moves along the forward rotation inclined surface 911 and abuts against the forward rotation limiting portion 811. Also, the second reverse rotation engagement portion 94 of the linear motion member 70 moves along the reverse rotation inclined surface 931 and abuts against the reverse rotation limiting portion 821. As a result, when the second forward rotation engagement portion 92 moves along the forward rotation inclined surface 911 or when the second reverse rotation engagement portion 94 moves along the reverse rotation inclined surface 931, the angular velocity of the relative rotation of the linear motion member 70 with respect to the piston 40 gradually decreases, and the linear motion member 70 abuts against the forward rotation limiting portion 811 or the reverse rotation limiting portion 821 at a relatively low angular velocity. Therefore, the impact when the linear motion member 70 abuts against the forward rotation limiting portion 811 or the reverse rotation limiting portion 821 can be mitigated, and the generation of abnormal noise can be suppressed.

<2> In this embodiment, when the linear motion member 70 abuts against the forward rotation limiting portion 811, the first abutment position Pt1, which is the position where the second forward rotation engagement portion 92 and the first forward rotation engagement portion 91 first abut, is between one end and the other end of the forward rotation inclined surface 911 in the axial Ax1 direction of the piston 40. When the linear motion member 70 abuts against the reverse rotation limiting portion 821, the second abutment position Pt2, which is the position where the second reverse rotation engagement portion 94 and the first reverse rotation engagement portion 93 first abut, is between one end and the other end of the reverse rotation inclined surface 931 in the axial Ax1 direction of the piston 40.

Therefore, when the linear motion member 70 rotates forward, the second forward rotation engagement portion 92 can be reliably brought into contact with the forward rotation inclined surface 911 of the first forward rotation engagement portion 91, the second forward rotation engagement portion 92 can be moved along the forward rotation inclined surface 911, and then the linear motion member 70 can be brought into contact with the forward rotation limiting portion 811. When the linear motion member 70 rotates reversely, the second reverse rotation engagement portion 94 can be reliably brought into contact with the reverse rotation inclined surface 931 of the first reverse rotation engagement portion 93, the second reverse rotation engagement portion 94 can be moved along the reverse rotation inclined surface 931, and then the linear motion member 70 can be brought into contact with the reverse rotation limiting portion 821. Therefore, the impact when the linear motion member 70 abuts on the forward rotation limiting portion 811 or the reverse rotation limiting portion 821 can be reliably mitigated, and the generation of abnormal noise can be suppressed.

Second Embodiment
A part of a vehicle brake device according to the second embodiment is shown in Fig. 13. The second embodiment differs from the first embodiment in the configurations of a forward rotation inclined surface 911 and a reverse rotation inclined surface 931.

<3> In this embodiment, the forward inclined surface 911 is formed so that the friction coefficient increases toward the forward rotation limiting section 811. The reverse inclined surface 931 is formed so that the friction coefficient increases toward the reverse rotation limiting section 821 (see FIG. 13).

More specifically, the forward inclined surface 911 is formed so that the surface roughness increases toward the forward limiting section 811, for example, so that the friction coefficient increases toward the forward limiting section 811. The reverse inclined surface 931 is formed so that the surface roughness increases toward the reverse limiting section 821, for example, so that the friction coefficient increases toward the reverse limiting section 821.

Therefore, in this embodiment, when the second forward rotation engagement portion 92 moves along the forward rotation inclined surface 911, or when the second reverse rotation engagement portion 94 moves along the reverse rotation inclined surface 931, the angular velocity of the relative rotation of the linear motion member 70 with respect to the piston 40 can be further reduced. Therefore, the impact when the linear motion member 70 abuts against the forward rotation limiting portion 811 or the reverse rotation limiting portion 821 can be further mitigated, and the generation of abnormal noise can be further suppressed.

Third Embodiment
A portion of a vehicle brake device according to the third embodiment is shown in Fig. 14. The third embodiment differs from the first embodiment in the configurations of a first forward rotation engaging portion 91, a first reverse rotation engaging portion 93, a forward rotation limiting portion 811, and a reverse rotation limiting portion 821.

In this embodiment, the first forward rotation engagement portion 91 does not have a forward rotation inclined surface 911. The first reverse rotation engagement portion 93 does not have a reverse rotation inclined surface 931 (see FIG. 14).

<5> In this embodiment, the forward rotation limiting portion 811 has a forward rotation elastic member (not shown) that is an elastic member that can abut against the second forward rotation engaging portion 92. The reverse rotation limiting portion 821 has a reverse rotation elastic member 96 that is an elastic member that can abut against the second reverse rotation engaging portion 94.

More specifically, the forward rotation elastic member and the reverse rotation elastic member 96 are formed to be elastically deformable, for example, from rubber or the like.

In this embodiment, when the linear motion member 70 abuts against the forward rotation limiting portion 811, the second forward rotation engaging portion 92 abuts against the forward rotation elastic member. When the linear motion member 70 abuts against the reverse rotation limiting portion 821, the second reverse rotation engaging portion 94 abuts against the reverse rotation elastic member 96. This reduces the impact when the linear motion member 70 abuts against the forward rotation limiting portion 811 or the reverse rotation limiting portion 821, and suppresses the generation of abnormal noise.

(Fourth embodiment)
A part of a vehicle brake device according to the fourth embodiment is shown in Fig. 15. The fourth embodiment differs from the first embodiment in the configurations of a forward rotation limiting portion 811 and a reverse rotation limiting portion 821.

<4> In this embodiment, the forward rotation limiting portion 811 has a forward rotation elastic member (not shown) that is an elastic member that can abut against the second forward rotation engaging portion 92. The reverse rotation limiting portion 821 has a reverse rotation elastic member 96 that is an elastic member that can abut against the second reverse rotation engaging portion 94.

More specifically, the forward rotation elastic member and the reverse rotation elastic member 96 are formed to be elastically deformable, for example, from rubber, as in the third embodiment.

In this embodiment, the effects of the forward inclined surface 911 and the reverse inclined surface 931 in the first embodiment and the effects of the forward elastic member and the reverse elastic member 96 in the third embodiment can be achieved, and the impact when the linear motion member 70 abuts against the forward rotation limiting portion 811 or the reverse rotation limiting portion 821 can be more effectively mitigated, and the generation of abnormal noise can be more effectively suppressed.

Other Embodiments
The present invention can combine the above-mentioned embodiments as long as there are no structural impediments. For example, the second embodiment and the third embodiment can be combined to form the forward inclined surface 911 so that the friction coefficient increases toward the forward rotation limiting portion 811, and the reverse inclined surface 931 so that the friction coefficient increases toward the reverse rotation limiting portion 821, and a forward rotation elastic member that is an elastic member that can abut against the second forward rotation engaging portion 92 and a reverse rotation elastic member 96 that is an elastic member that can abut against the second reverse rotation engaging portion 94 are provided.

In the above embodiment, an example was shown in which the rotation of the rotating member 60 is converted into linear motion of the linear motion member 70 by the male threaded portion 601 and the female threaded portion 701 being screwed together. In contrast, in other embodiments, for example, a ball screw may be provided between the rotating member 60 and the linear motion member 70, and the rotation of the rotating member 60 may be converted into linear motion of the linear motion member 70.

In another embodiment, hydraulic oil may be supplied to the inside of the piston 40, for example, to press the piston 40 against the pad 4 by hydraulic pressure.

The vehicle brake device of the present invention may be applied to all of the vehicle's multiple wheels, or to only some of the wheels.

The vehicle brake device of the present invention can be used as a braking brake to slow down or stop a moving vehicle, and can also be used as a parking brake.

As such, the present disclosure is not limited to the above-described embodiments, but can be implemented in various forms without departing from the spirit of the present disclosure.

2 Wheel, 3 Disk, 4 Pad, 10 Vehicle brake device, 20 Body, 30 Cylinder, 40 Piston, 50 Motor, 51 Rotor, 60 Rotating member, 70 Linear member, 90 Engagement part, 91 First normal rotation engagement part, 92 Second normal rotation engagement part, 93 First reverse rotation engagement part, 94 Second reverse rotation engagement part, 600 Rotation-linear motion conversion part, 811 Normal rotation limit part, 821 Reverse rotation limit part, 911 Normal rotation inclined surface, 931 Reverse rotation inclined surface, D1 First direction, D2 Second direction

Claims (5)

A vehicle brake device capable of restricting the rotation of a wheel (2) by pressing a pad (4) against a disk (3) that is rotatable together with the wheel, comprising:
A body (20);
A cylinder (30) provided in the body;
a piston (40) accommodated in the cylinder and moving within the cylinder to press the pad against the disk;
A motor (50) having a rotor (51) that rotates when energized;
A rotating member (60) that rotates in conjunction with the rotation of the rotor;
a linear motion member (70) that moves linearly in a first direction (D1) toward the pad in response to a forward rotation of the rotating member, and moves linearly in a second direction (D2) away from the pad in response to a reverse rotation of the rotating member;
A forward rotation limiting portion (811) that is provided on the piston and limits forward rotation of the linear motion member when the piston abuts against the linear motion member; and
a rotation-to-linear motion conversion unit (600) having a reverse rotation limiting unit (821) that is provided on the piston and limits the reverse rotation of the linear motion member when the linear motion member abuts against the piston;
A first forward rotation engaging portion (91) and a first reverse rotation engaging portion (93) provided on the piston, and
A second forward rotation engaging portion (92) and a second reverse rotation engaging portion (94) are provided on the linear motion member,
When the forward rotation of the linear motion member is restricted by the forward rotation restricting portion, the first forward rotation engaging portion and the second forward rotation engaging portion are in a forward rotation engaged state in which they overlap in the axial direction of the piston,
an engagement portion (90) that is in a reverse engagement state in which the first reverse engagement portion and the second reverse engagement portion overlap in the axial direction of the piston when the rotation member rotates in a reverse direction from the forward rotation engagement state and the reverse rotation of the linear motion member is restricted by the reverse rotation restriction portion,
The first forward rotation engagement portion has a forward rotation inclined surface (911) that is a surface inclined with respect to the axis of the piston,
The first reverse engagement portion has a reverse inclined surface (931) that is a surface inclined with respect to the axis of the piston,
When the linear motion member abuts against the forward rotation limiting portion, the second forward rotation engaging portion moves along the forward rotation inclined surface,
When the linear motion member abuts against the reverse rotation limiting portion, the second reverse rotation engaging portion moves along the reverse rotation inclined surface. a first abutment position (Pt1) at which the second normal rotation engagement portion and the first normal rotation engagement portion first abut when the linear motion member abuts against the normal rotation limiting portion is between one end and the other end of the normal rotation inclined surface in the axial direction of the piston,
2. The vehicle brake device according to claim 1, wherein a second abutment position (Pt2), which is a position where the second reverse engagement portion and the first reverse engagement portion first abut when the linear motion member abuts against the reverse rotation limiting portion, is between one end and the other end of the reverse rotation inclined surface in the axial direction of the piston. The forward rotation inclined surface is formed so that a friction coefficient increases toward the forward rotation limiting portion,
3. The vehicle brake device according to claim 1, wherein the reverse rotation inclined surface is formed so that a coefficient of friction increases toward the reverse rotation limiting portion. the forward rotation limiting portion has a forward rotation elastic member that is an elastic member that can come into contact with the second forward rotation engaging portion,
4. The vehicle brake device according to claim 1, wherein the reverse rotation limiting portion has a reverse rotation elastic member (96) that is an elastic member capable of coming into contact with the second reverse rotation engaging portion. A vehicle brake device capable of restricting the rotation of a wheel (2) by pressing a pad (4) against a disk (3) that is rotatable together with the wheel, comprising:
A body (20);
A cylinder (30) provided in the body;
a piston (40) accommodated in the cylinder and moving within the cylinder to press the pad against the disk;
A motor (50) having a rotor (51) that rotates when energized;
A rotating member (60) that rotates in conjunction with the rotation of the rotor;
a linear motion member (70) that moves linearly in a first direction (D1) toward the pad in response to a forward rotation of the rotating member, and moves linearly in a second direction (D2) away from the pad in response to a reverse rotation of the rotating member;
A forward rotation limiting portion (811) that is provided on the piston and limits forward rotation of the linear motion member when the piston abuts against the linear motion member; and
a rotation-to-linear motion conversion unit (600) having a reverse rotation limiting unit (821) that is provided on the piston and limits the reverse rotation of the linear motion member when the linear motion member abuts against the piston;
A first forward rotation engaging portion (91) and a first reverse rotation engaging portion (93) provided on the piston, and
A second forward rotation engaging portion (92) and a second reverse rotation engaging portion (94) are provided on the linear motion member,
When the forward rotation of the linear motion member is restricted by the forward rotation restricting portion, the first forward rotation engaging portion and the second forward rotation engaging portion are in a forward rotation engaged state in which they overlap in the axial direction of the piston,
an engagement portion (90) that is in a reverse engagement state in which the first reverse engagement portion and the second reverse engagement portion overlap in the axial direction of the piston when the rotation member rotates in a reverse direction from the forward rotation engagement state and the reverse rotation of the linear motion member is restricted by the reverse rotation restriction portion,
the forward rotation limiting portion has a forward rotation elastic member that is an elastic member that can come into contact with the second forward rotation engaging portion,
The reverse rotation limiting portion has a reverse rotation elastic member (96) that is an elastic member capable of contacting the second reverse rotation engaging portion.

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