JP7590643B2 - Brake system - Google Patents

Description

The present invention relates to a brake device for a vehicle seat.

Conventionally, a clutch device disclosed in Patent Document 1 below is known as a technology related to a brake device that is disposed in a vehicle seat and controls the torque transmitted from an input member to an output member when adjusting the position of the vehicle seat, for example. This clutch device is configured as a clutch device that transmits input torque input from a lever member in response to operation of an operating lever to a pinion gear via a rotation transmission member and outputs the input torque, and restricts rotation of the pinion gear when the input torque is eliminated. More specifically, a roller pressed by a spring enters a wedge-shaped space formed between the cam surface of an output cam attached to the pinion gear and the inner peripheral surface of the housing, thereby restricting rotation of the pinion gear. From this restricted state, the rotation transmission member rotates against the spring force in response to the operation of the operating lever, and the roller pressed by the pressing piece of this rotation transmission member moves against the spring and out of the wedge-shaped space, releasing the restriction. In this unrestricted state, the output side cam pressed by the rotation transmission member rotates, causing the pinion gear to rotate.

JP 2011-153675 A JP 2018-141478 A

In the above-mentioned configuration, as shown in FIG. 17, in order to ensure strength, etc., in a neutral state where there is no input torque, a gap G is provided between the pressing piece 201 of the rotation transmission member biased by the spring and the roller 203 biased by the spring 202 to enter the wedge-shaped space. In FIG. 17, the cam surface of the output cam is indicated by the reference numeral 204, and the inner peripheral surface of the housing is indicated by the reference numeral 205.

Such a gap causes play between when the rotation transmission member starts to rotate and when the pressing piece comes into contact with the roller (hereinafter referred to as "operation play"), and there is a problem in that this operation play reduces operability.

One known technology for suppressing such operational play is the clutch device disclosed in Patent Document 2. In this clutch device, a resin plate that is engaged and fixed to the rotation transmission member is press-fitted and fixed to the inner peripheral surface of the housing. With this configuration, even if the input torque is eliminated after the roller is released from the wedge-shaped space by the pressing piece of the rotation transmission member, which rotates in response to the input torque, the friction force between the resin plate and the housing makes it difficult for the rotation transmission member to rotate. As a result, the contact state between the pressing piece and the roller when pressed is maintained even after the input torque is eliminated, so the above-mentioned operational play can be suppressed.

However, in the above-mentioned configuration in which friction between the resin plate and the housing is used to suppress operating play, frictional force is always present when the rotation transmission member rotates, i.e., when the operating lever is operated, which creates the problem of an increased required operating force.

The present invention was made to solve the above-mentioned problems, and its purpose is to provide a configuration that can suppress operating play without increasing the operating force.

In order to achieve the above object, the invention of claim 1 described in the claims is as follows:
A brake device (10) for a vehicle seat that transmits and outputs an input torque from an input member (20) to an output member (30) via a rotation transmission member (40) and restricts rotation of the output member when the torque input to the input member is eliminated, comprising:
The output member is
An output shaft (35);
a brake cam (32) coaxially connected to the output shaft and having a plurality of cam surfaces (32a) formed on an outer circumferential surface thereof;
a ring (31) arranged such that a pair of wedge-shaped spaces are formed for each cam surface by an inner circumferential surface (31a) and the plurality of cam surfaces facing the inner circumferential surface;
a brake roller (33) for restricting relative rotation between the ring and the brake cam by entering the wedge-shaped space;
a biasing member (34) for biasing the brake roller toward the wedge-shaped space;
Equipped with
the rotation transmission member is a cylindrical member having a bottom and including a cylindrical portion and a side wall portion, and is configured to rotate in response to rotation of the input member to cause the brake roller to leave the wedge-shaped space against the biasing force of the biasing member and to rotate the brake cam,
an inner circumferential surface of the cylindrical portion faces a cam surface of the input member to form a wedge-shaped space into which an input side roller of the input member fits;
The side wall portion of the rotation transmission member is formed with a through hole (42a) through which the cylindrical portion (35b) of the output shaft passes and a regulating portion for disengaging the brake roller from the wedge-shaped space ,
The present invention is characterized in that a bush (50) is provided between the through hole and the cylindrical portion, and is in frictional contact with both the inner circumferential surface of the through hole and the outer circumferential surface of the cylindrical portion.
The symbols in parentheses above indicate the corresponding relationship with the specific means described in the embodiments described later.

In the invention of claim 1, a rotation transmission member is provided that rotates in response to the rotation of the input member to disengage the brake roller from the wedge-shaped space against the biasing force of the biasing member and rotate the brake cam connected to the output shaft. The rotation transmission member is formed with a through hole through which the cylindrical portion of the output shaft passes, and a bush is provided between the through hole and the cylindrical portion, which is in frictional contact with the inner peripheral surface of the through hole and the outer peripheral surface of the cylindrical portion.

As a result, even if the input torque disappears after the brake roller leaves the wedge-shaped space due to the rotation transmission member rotating in response to the input torque, the rotation transmission member is in frictional contact with the bush at its through hole, and a frictional force acts to maintain the contact state between the rotation transmission member and the brake roller, so the above-mentioned operating play can be suppressed. Furthermore, when the rotation transmission member rotates with the brake roller leaving the wedge-shaped space, the output shaft rotates integrally with the rotation transmission member, so no friction occurs in the bush interposed between the output shaft and the rotation transmission member, and the above-mentioned operating force does not increase. Therefore, a configuration can be realized that can suppress operating play without increasing the operating force.

1 is a side view showing a vehicle seat device to which a brake device according to the present invention is applied; FIG. 2 is a perspective view of the brake device as viewed from the input side. FIG. 2 is a perspective view of the brake device as seen from the output side. FIG. FIG. 2 is a side view of the brake device as viewed from the input side. FIG. 2 is a side view of the brake device as viewed from the output side. FIG. 6 is an enlarged cross-sectional view showing the X1-X1 cross section shown in FIG. 5 . 5 is an enlarged cross-sectional view showing the X2-X2 cross section shown in FIG. 4. 5 is an enlarged cross-sectional view showing a cross section taken along the line X3-X3 in FIG. 4. 5 is an enlarged cross-sectional view showing the X4-X4 cross section shown in FIG. 4. FIG. 12A is a view of the second cam as seen from the input side, and FIG. 12B is a side view of FIG. 12A. 13A is a diagram of the rotation transmission member as viewed from the input side, and FIG. 13B is a side view of FIG. 13A. FIG. 4 is an enlarged perspective view of a bush. Figure 15 (A) is an explanatory diagram illustrating a state in which a contact state between the regulating portion of the rotation transmission member and the second roller is maintained, and Figure 15 (B) is an explanatory diagram illustrating a state in which a contact state between the second roller and the regulating portion that is different from the state in Figure 15 (A) is maintained. 4 is a graph showing the change in operating torque in the brake device according to the present embodiment and the change in operating torque in a conventional configuration with operating play, with respect to the operating angle of the operating lever. FIG. 13 is an explanatory diagram illustrating an operating play in a conventional structure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle seat device to which a brake device for a vehicle seat according to the present invention is applied will be described with reference to the drawings.
1, the vehicle seat device 100 mainly includes a seat rail 101 that is slidable back and forth relative to a vehicle floor B, a seat cushion 102 that is attached to the seat rail 101 via a seat bracket (not shown) or the like, and a seat back 103 that is supported so as to be tiltable relative to the seat cushion 102. A vehicle seat brake device (clutch device) 10 according to the present invention is disposed on one side of the seat cushion 102, and an operating lever 104 is connected to the brake device 10.

This brake device 10 serves to adjust the height of the seat cushion 102 as desired by transmitting the input torque from the operating lever 104 to a known height mechanism (output mechanism) provided on the seat bracket via an input member and an output member, etc.

In other words, the brake device 10 transmits the torque input from the input member to the output member in response to the operation of the operating lever 104, and is configured so that when the torque input to the input member disappears, the rotation of the output member is restricted and only the input member returns to the neutral position. Therefore, in the brake device 10, when the operating lever 104 is in the horizontal neutral position N, the output member is fixed so as not to rotate so as to maintain the height of the seat cushion 102.

When the operating lever 104 of the brake device 10 is swung in the upward direction U to raise the height of the seat cushion 102, an input torque corresponding to this swinging operation is transmitted to the height mechanism via the input member and the output member. This raises the height of the seat cushion 102. Then, when the input torque is eliminated, the output member maintains its rotation angle, and the input member returns to the neutral position together with the operating lever 104, so that the raised height of the seat cushion 102 is maintained.

On the other hand, when the operating lever 104 of the brake device 10 is swung in the downward direction D to lower the height of the seat cushion 102, an input torque corresponding to this swinging operation is transmitted to the height mechanism via the input member and the output member. This lowers the height of the seat cushion 102. Then, when the input torque is eliminated, the output member maintains its rotation angle, and the input member returns to the neutral position together with the operating lever 104, so that the lowered height of the seat cushion 102 is maintained.

Next, the configuration of the brake device 10 will be described with reference to the drawings.
As shown in Figures 2 to 11, the brake device 10 includes an input member 20 having a lever member 21, a cover 22, a wave washer 23, a first cam 24, six first rollers 25, three first springs 26, and two washers 27, 28, an output member 30 having a ring 31, a second cam 32, ten second rollers 33, five second springs 34, a pinion gear 35, and a friction spring 36, a rotation transmission member 40, a bush 50, and a bracket 60, and the input member 20 and the output member 30 are arranged coaxially via the rotation transmission member 40.

First, each part constituting the input member 20 will be described.
The lever member 21 is fastened to the operating lever 104 by using three tapping screws 110 that function as fastening members, and plays a role in transmitting input torque generated by the swing operation of the operating lever 104 to the first cam 24, etc. In addition, in Fig. 8, for the sake of convenience, the operating lever 104 and the tapping screws 110 are illustrated by two-dot chain lines.

As shown in Figs. 2, 5 and 7, the lever member 21 is flat and has three recesses 21a, each of which is made up of an arc-shaped bottom edge 21b and one side edge 21c and the other side edge 21d that are connected to the bottom edge 21b, and is recessed inward relative to the outer edge. In this embodiment, the term "flat" refers to a shape obtained by processing a plate-shaped material with parallel front and back surfaces, and includes a shape in which some of the recesses are uneven. The recesses 21a have the same shape and are arranged at equal intervals in the circumferential direction. In addition, an engagement hole 21e with which the first cam 24 engages is formed in the center of the lever member 21, and three through holes 21f for fixing the tapping screws 110 are formed around the engagement hole 21e.

As shown in Figures 7 and 8, the cover 22 is an input side cover formed in a generally cylindrical shape with a bottom, including a side wall portion 22a that serves as the bottom, and a cylindrical portion 22f. A through hole 22b is formed in the center of the side wall portion 22a, through which an engaging protrusion 24b of the first cam 24 described below is inserted. This through hole 22b is formed so that the engaging protrusion 24b does not come into contact when the first cam 24 rotates. In addition, three guide pieces 22c, three insertion holes 22d, and three restriction portions 22e are provided around the through hole 22b.

Each guide piece 22c controls the rotation range of the lever member 21, and is formed by cutting out a part of the side wall portion 22a toward the input side at positions that are equally spaced in the circumferential direction. The guide piece 22c is formed so that it abuts against one side edge 21c when the lever member 21 rotates to one end of the rotation range, and abuts against the other side edge 21d when the lever member 21 rotates to the other end of the rotation range. In this embodiment, as shown in FIG. 5, each recess 21a is arranged so that it faces the guide piece 22c at the center of the bottom edge 21b in the neutral position. This makes the rotation angle of the lever member 21 from the neutral position to one end of the rotation range the same as the rotation angle of the lever member 21 to the other end of the rotation range.

Each insertion hole 22d is elongated so as not to come into contact with the tapping screw 110 that moves with the rotation of the lever member 21, and is formed so as to connect to the cut-out portion of the guide piece 22c.

Each regulating portion 22e is equally spaced in the circumferential direction and is formed by cutting out a portion of the side wall portion 22a toward the output side so that it is positioned between the first rollers 25 that correspond to a pair of cam surfaces 24a described below (see Figure 9).

The cylindrical portion 22f is formed in a cylindrical shape such that slits are interposed between the multiple extensions. More specifically, the cylindrical portion 22f is formed such that six extensions 22g and six slits 22h are positioned at equal intervals, and a ring 31 is pressed into the inner peripheral surface side of each extension 22g. In addition, each slit 22h has the same shape, and is formed so that the opening width becomes wider as it is farther away from the side wall portion 22a. In this embodiment, in order to achieve both a reduction in the press-in force and ensuring the necessary welding strength, the circumferential length of each extension 22g at the welded portion is set to be about twice the circumferential width of the slit 22h.

As shown in FIG. 8, the wave washer 23 is positioned to apply an axial biasing force to both the side wall portion 22a of the cover 22 and the first cam 24. By positioning the wave washer 23 in this manner, axial play is suppressed, which makes it possible to stabilize the vertical position of the inner surface of the first cam 24 and the rotation transmission member 40 and to stabilize the operation of the second roller 33.

7 and 9, the first cam 24 has three pairs of cam surfaces 24a at equal intervals on its outer peripheral surface, and each cam surface 24a is arranged to form six wedge-shaped spaces between the inner peripheral surface 41a of the rotation transmission member 40 described later. At the center of the first cam 24, an engagement protrusion 24b is provided so as to protrude toward the input side and engages with the engagement hole 21e of the lever member 21 when inserted through the through hole 22b of the cover 22. In addition, three grooves 24c are provided at equal intervals on the outer peripheral surface of the first cam 24, and each groove 24c is formed so that a tapping screw 110 fastened to the lever member 21 can be inserted into it (see FIG. 9).

Each first roller 25 is an input roller formed in a substantially cylindrical shape, and is arranged so that its diameter has a play to allow forward and reverse rotation within a pair of opposing wedge-shaped spaces formed by the cam surface 24a of the first cam 24 and the inner peripheral surface 41a of the rotation transmission member 40. As shown in FIG. 9, the restricting portion 22e of the cover 22 is located between the first rollers 25 that correspond to the pair of cam surfaces 24a.

The first spring 26 is a coil spring-shaped biasing member, and as shown in FIG. 9, is arranged so that one end biases the first roller 25 toward the regulating portion 22e, and the other end biases a different first roller 25 toward a different regulating portion 22e.

The washer 27 is disposed between the first roller 25 and the first spring 26 and the side wall portion 22a of the cover 22, and functions to prevent contact between the expanding and contracting first spring 26 and the side wall portion 22a, and to suppress movement of the first roller 25 toward the axial input side.

The washer 28 is disposed between the first roller 25 and the first spring 26 and the side wall portion 42 of the rotation transmission member 40, and functions to prevent contact between the expanding and contracting first spring 26 and the side wall portion 42, and to suppress movement of the first roller 25 toward the axial output side.

Next, each part constituting the output member 30 will be described.
2 to 4, the ring 31 is an annular member whose outer circumferential surface constitutes part of the outer shell of the brake device 10. As shown in Fig. 10, the ring 31 is disposed such that a wedge-shaped space is formed for each cam surface 32a by its inner circumferential surface 31a and the cam surface 32a of the second cam 32 facing the inner circumferential surface 31a. The ring 31 is also formed such that its outer circumferential surface is press-fitted into the inner circumferential surface side of each extension portion 22g of the cover 22.

As shown in Figures 12(A) and 12(B), the second cam 32 has five pairs of cam surfaces 32a at equal intervals on its outer peripheral surface, and each cam surface 32a is arranged to form ten wedge-shaped spaces between itself and the inner peripheral surface 31a of the ring 31 (see Figure 10). An engagement hole 32b is formed in the center of the second cam 32 for coaxial engagement with the pinion gear 35. In addition, five engagement protrusions 32c are arranged at equal intervals in the circumferential direction on the input side end surface of the second cam 32. The second cam 32 can be an example of a "brake cam."

Each second roller 33 is formed in a generally cylindrical shape, and is arranged so that its diameter has a play to allow forward and reverse rotation within a pair of opposing wedge-shaped spaces formed by the cam surface 32a of the second cam 32 and the inner peripheral surface 31a of the ring 31. As shown in FIG. 10, a regulating portion 42c of the rotation transmission member 40 (described later) is located between the second rollers 33 that correspond to the pair of cam surfaces 32a. The second rollers 33 may be an example of a "brake roller."

The second spring 34 is a coil spring-shaped biasing member, and as shown in FIG. 10, is arranged so that one end biases the second roller 33 toward the regulating portion 42c, and the other end biases a different second roller 33 toward a different regulating portion 42c.

As shown in Figures 7 and 8, an engagement protrusion 35a that engages with the engagement hole 32b of the second cam 32 is formed on the input side of the pinion gear 35, and a cylindrical portion 35b is formed so as to extend coaxially from the engagement protrusion 35a. The pinion gear 35 can be an example of an "output shaft."

As shown in Figures 7 and 8, the friction spring 36 is arranged so that the engagement hole 36a engages with the engagement protrusion 35a of the pinion gear 35 together with the engagement hole 32b of the second cam 32. This friction spring 36 slides against the inner peripheral surface 31a of the ring 31 when the pinion gear 35 rotates, thereby applying a biasing force to the pinion gear 35 in the reverse rotation direction.

Next, the rotation transmission member 40 and the bush 50 for transmitting the torque input from the input member 20 to the output member 30 will be described.
13A and 13B, the rotation transmission member 40 is formed in a generally cylindrical shape with a bottom, and includes a cylindrical portion 41 and a side wall portion 42. The cylindrical portion 41 is disposed so that its inner circumferential surface 41a faces each of the cam surfaces 24a of the first cam 24 to form the wedge-shaped space (see FIG. 11).

The side wall portion 42 has a through hole 42a formed in its center through which the cylindrical portion 35b of the pinion gear 35 is inserted, and five engagement holes 42b are formed at equal intervals in the circumferential direction based on the through hole 42a. As shown in FIG. 11, each engagement hole 42b is formed so that the engagement protrusions 32c of the second cam 32 are inserted through them with a predetermined gap in the circumferential direction.

A restricting portion 42c extending toward the output side is provided on the outer edge of each engagement hole 42b by utilizing the cut-and-raised portions formed when the engagement hole 42b is formed. Each restricting portion 42c is formed to be equidistantly spaced in the circumferential direction and positioned between the second rollers 33 corresponding to the pair of cam surfaces 24a of the second cam 32 (see FIG. 10). For convenience, FIG. 10 illustrates the restricting portion 42c as not contacting the second rollers 33.

As shown in FIG. 14, the bush 50 is configured to include a substantially cylindrical bush main body 51 with axially formed slits 53, and a flange portion 52. The bush main body 51 is formed by bending a metal plate material with a resin coating applied to the plate surfaces constituting the outer peripheral surface 51a and the inner peripheral surface 51b into a cylindrical shape. When no external force is applied, the inner diameter of the inner peripheral surface 51b of the bush main body 51 is slightly smaller than the outer diameter of the cylindrical portion 35b of the pinion gear 35, and when assembled to the outer peripheral surface of the cylindrical portion 35b, the outer peripheral surface 51a is in frictional contact with the inner peripheral surface of the through hole 42a of the rotation transmission member 40.

The bush 50 configured in this manner is arranged so that the outer peripheral surface 51a of the bush main body 51 is in frictional contact with the inner peripheral surface of the through hole 42a of the rotation transmission member 40 when the inner peripheral surface 51b of the bush main body 51 is assembled to the outer peripheral surface of the cylindrical portion 35b. With the bush 50 arranged in this manner, when the rotation transmission member 40 rotates relative to the pinion gear 35, a frictional force that suppresses the relative rotation acts on the rotation transmission member 40 via the bush 50.

The bracket 60 is a cover member that covers the ring 31, the second cam 32, etc. from the output side, and has a through hole 61 formed in the center through which the pinion gear 35 passes, and a total of three connection holes 62 formed at one end and the other end for connecting to the seat cushion 102.

In the brake device 10 configured in this manner, the cover 22 is welded and fixed to the outer circumferential surface of the ring 31 with the ring 31 pressed into the inner circumferential surface of each extension 22g. Specifically, the cover 22 is welded and fixed at a position a predetermined distance L (e.g., 2 mm: see FIG. 4) away from the input end face of the ring 31 so that the circumferential weld length of each extension 22g is a predetermined angle (e.g., 30°) based on the rotation axis. For example, laser welding or TIG welding can be used as the welding method. In FIG. 4, the welded portion W is shown by a thick line.

Next, the operation of the input member 20, the output member 30, etc. in the brake device 10 configured as described above will be described with reference to FIGS.
When the operating lever 104 is not operated, the lever member 21 and the first cam 24 are positioned in the neutral position with the two first rollers 25, each biased by a different first spring 26, being pressed from different directions against one regulating portion 22e.

When the operating lever 104 is swung from the neutral position N in the upward direction U or downward direction D in response to the operating force applied to the operating lever 104, the lever member 21 and the first cam 24 rotate in a direction corresponding to the swinging operation. At that time, the first roller 25 corresponding to the cam surface 24a on the rotating direction side of the pair of cam surfaces 24a enters the gap space formed by the cam surface 24a, resulting in a locked state, and the rotation transmission member 40 forming the gap space also rotates together with the first cam 24. Meanwhile, the first roller 25 corresponding to the other cam surface 24a is maintained in a state of being pressed against the restricting portion 22e by the first spring 26.

As described above, the second roller 33, which is pressed in the rotation direction by the restricting portion 42c of the rotating rotation transmission member 40, leaves the wedge-shaped space, and the restriction on the relative rotation of the second cam 32 with respect to the ring 31 is released. Therefore, when the rotation transmission member 40 rotates in response to the rotation of the input member 20, the restricting portion 42c functions to cause the second roller 33 to leave the wedge-shaped space against the biasing force of the second spring 34.

Then, the engaging protrusion 32c of the second cam 32 that is inserted into the engaging hole 42b of the rotation transmission member 40 is pressed against the outer edge of the engaging hole 42b, and the second cam 32 rotates together with the rotation transmission member 40, and the pinion gear 35 that engages with this second cam 32 rotates. Therefore, with the second roller 33 removed from the wedge-shaped space, the engaging hole 42b functions to rotate the second cam 32 by pressing the engaging protrusion 32c in the rotation direction.

As a result, the input torque input from the input member 20 is transmitted to the height mechanism via the pinion gear 35 of the output member 30. In this way, when the pinion gear 35 rotates together with the rotation transmission member 40, the bush 50 interposed between the inner circumferential surface of the through hole 42a of the rotation transmission member 40 and the outer circumferential surface of the cylindrical portion 35b of the pinion gear 35 also rotates together, so no frictional force is generated in the bush 50.

When the input torque is eliminated by releasing the operating force, the first roller 25, which has been receiving a force from the cam surface 24a, returns to its original position so as to be pressed against the restricting portion 22e by the biasing force of the first spring 26. Therefore, the first roller 25, which is trying to return to its original position as described above, exerts a force on the rotation transmission member 40 to rotate it in the opposite direction to that during operation. At this time, since the rotation transmission member 40 is in frictional contact with the outer peripheral surface 51a of the bush 50 at the through hole 42a, the rotation transmission member 40 is prevented from rotating in the opposite direction as described above. As a result, even after the input torque is eliminated, the contact state between the restricting portion 42c of the rotation transmission member 40 and the second roller 33 is maintained as shown in FIG. 15(A), so that the operating play from when the rotation transmission member 40 starts to rotate in the same direction as the previous time until it contacts the second roller 33 at the restricting portion 42c can be eliminated.

When the operating lever 104 is operated in the opposite direction to the previous operation, the regulating part 42c is not in contact with the second roller 33 in the rotation direction during the first operation, so there is some operating play. However, during subsequent operations in the same rotation direction, as shown in FIG. 15(B), the regulating part 42c is in contact with a different second roller 33 than in the state shown in FIG. 15(A), so the operating play can be eliminated.

Next, the effect of the brake device 10 in reducing the operating force will be described with reference to FIG. 16. In FIG. 16, the change in operating torque in the brake device 10 according to this embodiment is shown as T1, and the change in operating torque in a conventional configuration with operating play is shown as T2, with respect to the operating angle of the operating lever 104.

As shown in FIG. 16, in a conventional configuration with operating play, even if the operating angle starts to increase as the operating lever 104 begins to be operated, the pressing piece (see reference number 201 in FIG. 17) of the rotation transmission member is not in contact with the roller (see reference number 203 in FIG. 17), so the rotation transmission member etc. does not rotate and the operating torque T2 required for operation does not increase significantly. After that, when the pressing piece comes into contact with the roller and the rotation transmission member etc. begins to rotate, the operating angle increases, and the operating torque T2 increases sharply and then stabilizes.

In contrast, in the brake device 10 with reduced operating play, when the operating angle begins to increase by starting to operate the operating lever 104, the restricting portion 42c of the rotation transmission member 40 is already in contact with the second roller 33 as described above, so the rotation transmission member 40 etc. immediately begins to rotate and the operating torque T1 required for operation increases. After that, when the operating angle reaches a point where the pinion gear 35 rotates integrally with the rotation transmission member 40, the frictional force of the bush 50 no longer acts, and the operating torque T1 stabilizes at approximately the same value as the operating torque T2.

As described above, in the brake device 10 according to this embodiment, a rotation transmission member 40 is provided that rotates in response to the rotation of the input member 20 to disengage the second roller 33 from the wedge-shaped space against the biasing force of the second spring 34 and rotate the second cam 32 connected to the pinion gear 35. The rotation transmission member 40 is provided with a through hole 42a through which the cylindrical portion 35b of the pinion gear 35 passes, and a bushing 50 is provided between the through hole 42a and the cylindrical portion 35b, which is in frictional contact with both the inner peripheral surface of the through hole 42a and the outer peripheral surface of the cylindrical portion 35b.

As a result, even if the input torque disappears after the second roller 33 leaves the wedge-shaped space due to the rotation transmission member 40 rotating in response to the input torque, the rotation transmission member 40 is in frictional contact with the bush 50 at its through hole 42a, and a frictional force acts to maintain the contact state between the rotation transmission member 40 and the second roller 33, so the above-mentioned operating play can be suppressed. Furthermore, when the rotation transmission member 40 rotates with the second roller 33 leaving the wedge-shaped space, the pinion gear 35 rotates integrally with the rotation transmission member 40, so friction does not occur in the bush 50 interposed between the pinion gear 35 and the rotation transmission member 40, and the above-mentioned operating force does not increase. Therefore, a configuration that can suppress the operating play without increasing the operating force can be realized.

[Other embodiments]
The present invention is not limited to the above-described embodiment, and may be embodied as follows, for example.
(1) The bushing 50 is not limited to being constructed by bending a metal plate having a resin coating on its surface into a cylindrical shape, but may be any member that exerts a frictional force on the through hole 42a of the rotation transmission member 40, and may be constructed, for example, from a cylindrical member made of resin.

REFERENCE SIGNS LIST 10 Brake device 20 Input member 30 Output member 31 Ring 31a Inner peripheral surface 32 Second cam (brake cam)
32a... cam surface 33... second roller (brake roller)
34...Second spring (biasing member)
35...Pinion gear (output shaft)
35b: cylindrical portion 40: rotation transmission member 42a: through hole 50: bush 51: bush body 100: vehicle seat device

Claims (1)

1. A brake device for a vehicle seat that transmits an input torque from an input member through a rotation transmission member to an output member and outputs the torque, and restricts rotation of the output member when the torque input to the input member is eliminated, comprising:
The output member is
An output shaft;
a brake cam that is coaxially connected to the output shaft and has a plurality of cam surfaces formed on an outer circumferential surface thereof;
a ring disposed such that a pair of wedge-shaped spaces are formed for each cam surface by an inner circumferential surface and the plurality of cam surfaces facing the inner circumferential surface;
a brake roller for restricting relative rotation between the ring and the brake cam by entering the wedge-shaped space;
A biasing member that biases the brake roller toward the wedge-shaped space;
Equipped with
the rotation transmission member is a cylindrical member having a bottom and including a cylindrical portion and a side wall portion, and is configured to rotate in response to rotation of the input member to cause the brake roller to leave the wedge-shaped space against the biasing force of the biasing member and to rotate the brake cam,
an inner circumferential surface of the cylindrical portion faces a cam surface of the input member to form a wedge-shaped space into which an input side roller of the input member fits;
a through hole through which the cylindrical portion of the output shaft passes and a restricting portion for disengaging the brake roller from the wedge-shaped space are formed in the side wall portion of the rotation transmission member;
A brake device, comprising: a bushing provided between the through hole and the cylindrical portion, the bushing being in frictional contact with an inner circumferential surface of the through hole and an outer circumferential surface of the cylindrical portion.

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