Brake system for vehicle seats

Abstract

By forming a bolt insertion hole through the center of the wedge cam instead of an internal threaded hole, manufacturing efficiency can be improved and manufacturing costs can be reduced. [Solution] The drive mechanism 10 includes a fixing bolt 32 and a nut 33 that integrally connect the lever bracket 24 and the wedge cam 19. The lever bracket has a bolt hole 24b through which the shaft portion 32b of the fixing bolt is inserted. The wedge cam has a bolt insertion hole 19b through which the shaft portion of the fixing bolt can be inserted, and also has a recess 19d on one edge of the bolt insertion hole through which the head portion 32a of the fixing bolt engages, thereby restricting the rotation of the fixing bolt. The shaft portion is rotatably connected to the lever bracket and the wedge cam by fastening a nut 33 to the tip through which a male thread 13c formed on the outer circumference is inserted into the bolt insertion hole.

Description

Technical Field

[0001] The present invention relates to a braking device for a vehicle seat incorporated in a position adjustment mechanism such as a seat lifter mechanism for adjusting the height position of a seat cushion that serves as a seating surface of a seat, or a reclining mechanism for adjusting the angular position of a seat back that serves as a backrest of the seat.

Background Art

[0002] As a braking device for this type of vehicle seat, for example, the one described in Patent Document 1 below has been proposed.

[0003] The braking device described in this Patent Document 1 is incorporated in, for example, a seat lifter mechanism, and transmits an operating force in the forward or reverse direction input to an operating lever to a pinion shaft, which is an output shaft, via a roller clutch mechanism and outputs it to the vehicle seat.

[0004] One end portion in the longitudinal direction of the operating lever is formed in a substantially circular shape, and a bolt insertion hole through which the shaft portion of the bolt is inserted is formed through the center of the one end portion. Further, on the inner surface of the one end portion, engaging grooves extending radially in three directions around the bolt insertion hole are formed.

[0005] On one end portion side of the operating lever, a bottomed cylindrical support body that forms a part of the roller clutch mechanism is provided. Inside this support body, a substantially disk-shaped cam, which is an input member, is accommodated and arranged. In the center of this cam, a female screw hole into which the male screw portion of the shaft portion of the bolt is screwed is formed. Further, the cam is provided, on one end side in the axial direction, with a convex central portion that engages with the engaging groove of the operating lever and bridges extending radially in three directions from the central portion.

[0006] Then, while engaging the convex central portion and the bridges of the cam with the engaging groove of the operating lever, the operating lever and the cam are fastened by a bolt, and the operating force of the operating lever is transmitted to the cam.

Prior Art Documents

[0007] [Patent Document 1] WO2010 / 109127A1 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the brake device described in Patent Document 1 fastens the operating lever and the cam together with a bolt, and a female threaded hole is formed in the center of the cam into which the male threaded portion of the bolt shaft is screwed. Since this female threaded hole must be processed separately from the cam's forming process, the cam forming process becomes complicated, leading to a decrease in manufacturing efficiency and an increase in manufacturing costs. In other words, while cams are generally formed from metal materials by press working, the female threaded hole requires separate processing such as tapping or cutting after the cam has been formed. As a result, there is a risk that manufacturing efficiency will decrease and manufacturing costs will increase.

[0009] This invention has been made in view of the technical problems of the conventional brake devices described above. Since the wedge cam does not have a female screw hole, but only a bolt insertion hole is formed, no processing other than press forming is required, and the present invention provides a brake device for a vehicle seat that improves manufacturing efficiency and reduces manufacturing costs. [Means for solving the problem]

[0010] The present invention relates to a brake device provided on a seat adjuster of a vehicle seat, comprising: a brake mechanism that includes a drive-side gear provided at one end of the output shaft, and that puts the output shaft in a braking state so as not to rotate in response to a reverse input from the drive-side gear; and a drive mechanism that releases the braking state of the output shaft and allows the output shaft to rotate in either the forward or reverse direction when an operating member is rotated from a neutral position in either the forward or reverse direction, wherein the brake mechanism and the drive mechanism are arranged coaxially with each other. The drive mechanism comprises a lever bracket, a wedge cam that rotates integrally with the lever bracket, and a bolt and nut that integrally connect the lever bracket and the wedge cam. The lever bracket has a bolt hole through which the shaft of the bolt is inserted in a through state, The wedge cam has a bolt insertion hole through which the shaft of the bolt can be inserted, and a recess into which the head of the bolt can be fitted while its rotation is restricted. The shaft portion of the bolt has a male threaded portion formed on its outer circumference, and the lever bracket and the wedge cam are rotatably connected as a single unit by fastening the nut to the tip portion which penetrates the bolt insertion hole and the bolt hole of the lever bracket. [Effects of the Invention]

[0011] According to the present invention, since the wedge cam only has a simple bolt insertion hole instead of a female screw hole, it is possible to improve the efficiency of the brake device manufacturing process and reduce manufacturing costs. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view showing an example of a vehicle seat equipped with a seat lifting mechanism and a seat reclining mechanism as position adjustment mechanisms. [Figure 2] This is a right side view of the brake device according to the present invention. [Figure 3] Figure 2 is a front view of the brake system. [Figure 4]It is a perspective view of the braking device shown in FIG. 2. [Figure 5] It is a sectional view taken along the line A-A of FIG. 3. [Figure 6] It is an exploded perspective view of the respective components of the brake mechanism part and the drive mechanism part in the braking device shown in FIG. 2. [Figure 7] It is an explanatory view of the neutral state of the brake mechanism part shown with the drive mechanism part removed. [Figure 8] It is a perspective view of the pinion shaft provided in the present embodiment. [Figure 9] It is a front view of the drive wheel provided in the present embodiment. [Figure 10] It is a sectional view taken along the line B-B of FIG. 9. [Figure 11] It is a perspective view of the drive wheel provided in the present embodiment. [Figure 12] It is a perspective view of the cover member provided in the present embodiment. [Figure 13] It is a view taken in the direction of arrow C in FIG. 5, showing the wedge cam and the bolt provided in the present embodiment. [Figure 14] It is a front view showing the drive mechanism part with the lever bracket and the cover member of the present embodiment removed. [Figure 15] It shows the state in which the lever bracket in the present embodiment is rotated clockwise from the neutral position. (a) is a front view seen from the lever bracket side, (b) is a front view of the drive mechanism part with the lever bracket and the cover member removed, and (c) is a front view of the drive wheel with the drive mechanism part removed. [Figure 16] It shows the state in which the lever bracket in the present embodiment is rotated counterclockwise from the neutral position. (a) is a front view seen from the lever bracket side, (b) is a front view of the drive mechanism part with the lever bracket and the cover member removed, and (c) is a front view of the drive wheel with the drive mechanism part removed. [Figure 17] It is a sectional view corresponding to the sectional view taken along the line A-A of FIG. 3 for explaining the case where the bolt insertion hole of the wedge cam and the shaft part of the bolt in the present embodiment are lightly press-fitted. [Figure 18]It is a view seen from the direction of arrow C in FIG. 5 for explaining the case where the concave portion of the wedge cam and the head portion of the bolt are lightly press-fitted in the present embodiment.

Mode for Carrying Out the Invention

[0013] Hereinafter, an embodiment of a brake device for a vehicle seat (hereinafter, simply referred to as "seat") according to the present invention will be described.

[0014] FIG. 1 shows an example of a seat provided with a position adjustment structure. As shown in FIG. 1, the seat 1 includes, as a so-called position adjustment mechanism, a seat slide mechanism 2 for adjusting the front-rear position of the seat 1, a seat lifter mechanism for adjusting the height position of a seat cushion 3 serving as a seating surface, and a reclining mechanism for adjusting the angle of a seat back 4 serving as a backrest portion. As an operation for each of these mechanisms, an operation lever 5 which is an operation member of the seat lifter mechanism and an operation lever 6 of the reclining mechanism are provided side by side on the side portion of the seat cushion 3.

[0015] This is a known structure in which, when paying attention to the seat lifter mechanism in the seat 1 shown in FIG. 1, each time the operation lever 5 of the seat lifter mechanism is pulled upward from, for example, a neutral position (in the following description, the state where the operation lever 5 is in the neutral position is also referred to as a "neutral state"), the position of the seat cushion 3 gradually increases, while conversely, each time the operation lever 5 is pushed downward from the neutral position, the position of the seat cushion 3 gradually decreases. Thereby, the height position adjustment function of the seating surface of the seat 1 is exhibited.

[0016] (Configuration of Brake Device) FIG. 2 is a right side view of the brake device according to the present invention, FIG. 3 is a front view of the brake device shown in FIG. 2, FIG. 4 is a perspective view of the brake device shown in FIG. 2, FIG. 5 is a cross-sectional view taken along line A-A of FIG. 3, FIG. 6 is an exploded perspective view of the respective components of the brake mechanism portion and the drive mechanism portion in the brake device shown in FIG. 2, FIG. 7 is an explanatory view of the neutral state of the brake mechanism portion shown with the drive mechanism portion removed, and FIG. 8 is a perspective view of a pinion shaft used in the present embodiment.

[0017] In the explanation of each figure, the direction of the rotation axis of the pinion shaft 12, which is the output shaft described later, will be referred to as the "axial direction," the right side of Figure 6 (housing 11 side) that is close to the seat (not shown) will be referred to as the "axial inner side," and the left side of Figure 6 (lever bracket 24 side) that is away from the seat (not shown) will be referred to as the "axial outer side."

[0018] As shown in Figure 2 and the exploded perspective view in Figure 6, the brake device 7 forms a nearly cylindrical case by butting a bottomed cylindrical brake housing, the housing 11, with a lid-shaped cover member 22. Some components of the brake mechanism 9 and the drive mechanism 10, which will be described later, are housed coaxially within this case. A pinion shaft 12, which is substantially shared by the brake mechanism 9 and the drive mechanism 10, is positioned axially at the center of the housing 11 that forms the case. A lever bracket 24, which functions as an operating member together with the operating lever 5 shown in Figure 1, is rotatably positioned coaxially with the pinion shaft 12, integrally with the wedge cam 19 that constitutes the drive mechanism 10, at one end of the pinion shaft 12. A pinion gear 12a, which is a drive-side gear that penetrates the housing 11 and is exposed to the outside, is integrally provided at the axially inner end of the pinion shaft 12.

[0019] The lever bracket 24 can be rotated in either the forward or reverse direction from the neutral position. The operating lever 5 is secured to the lever bracket 24 by two screws (not shown) that pass through screw insertion holes 24a, which will be described later, formed on the outer circumference of the lever bracket 24.

[0020] The brake device 7 is then fixed to the side bracket (not shown) of the seat 1 shown in Figure 1 using the three mounting holes 8a of the mounting bracket 8 fixed to the bottom surface of the housing 11, and the pinion gear 12a of the pinion shaft 12 meshes with the driven gear on the seat lifter mechanism side, which is the drive mechanism of the seat 1 (not shown).

[0021] In this brake device 7, when the lever bracket 24 is in the neutral position, a braking state is maintained so that the pinion shaft 12 does not rotate due to reverse input from the pinion shaft 12 side. On the other hand, when the lever bracket 24 is rotated from the neutral position in either the forward or reverse direction, the braking state of the pinion shaft 12 is released, and the rotation of the pinion shaft 12 is permitted. This rotation of the pinion shaft 12 is converted into rotational displacement of the driven gear of the seat lifter mechanism (not shown) via the pinion gear 12a, and further converted into vertical displacement of the seat cushion 3 of the seat 1 via the link mechanism.

[0022] Furthermore, in this type of brake device 7, because the stroke of the lever bracket 24 is relatively small, the intended purpose can often be achieved by repeatedly rotating the lever bracket 24 in a specific direction multiple times.

[0023] As mentioned earlier, as shown in Figures 2 and 6, the brake mechanism 9 and some components of the drive mechanism 10 are arranged adjacent to each other coaxially inside the case formed by the housing 11 and the cover member 22. In the following explanation, the structure will be described mainly using Figure 6, which makes the three-dimensional shape and arrangement of each component relatively easy to understand, and other figures will be referred to as appropriate when necessary.

[0024] As shown in Figure 6, the brake mechanism 9 comprises a housing 11, a pinion shaft 12 rotatably supported by the housing 11, a pair of substantially semicircular lock plates 14 arranged facing each other inside the housing 11, a lock spring 15 shared by these pairs of lock plates 14, another pair of lock plates 16 of the same shape arranged overlapping the pair of lock plates 14 axially outward inside the housing 11, and a lock spring 17 shared by these pairs of lock plates 16.

[0025] The drive mechanism 10 includes a shallow dish-shaped drive wheel 18 arranged on the axially outer side of the pair of lock plates 16, a cover member 22 that forms a case when it abuts against the housing 11 on the brake mechanism 9 side, a disc-shaped wedge cam 19 arranged on the axially inner side of the cover member 22, six rollers 20 arranged at 120° positions on the outer circumferential surface of the wedge cam 19, three roller biasing springs 23, and the lever bracket 24 as an operating member, which is also arranged on the axially outer side of the cover member 22.

[0026] The housing 11 of the brake mechanism 9 shown in Figure 6 is formed by drawing and press-forming a sheet metal material of a predetermined thickness into a roughly deep dish shape, and the inner circumferential surface of the housing 11 is the friction cylindrical surface 13 which is the braking surface.

[0027] Furthermore, a shaft hole 11a is formed through the bottom of the housing 11, extending axially, into which the large-diameter shaft portion 12b of the pinion shaft 12 on the pinion gear 12a side is inserted. This shaft hole 11a is formed in a cylindrical shape with a flange extending axially along its edge. In addition, three flange portions 11b extending radially outward are formed at the opening edge of the housing 11, and a locking recess 11c is formed at the tip of each flange portion 11b, with a recess in the center. These locking recesses 11c serve as connection and fixing portions with the cover member 22, which will be described later.

[0028] As shown in Figure 6, the pinion shaft 12 of the brake mechanism 9 includes, as also shown in Figure 8, a pinion gear 12a as a drive-side gear, a large-diameter shaft portion 12b as a bearing portion rotatably supported in the shaft hole 11a of the housing 11, a tip shaft portion 12c provided at the tip of the pinion gear 12a, and a substantially rectangular shaft-shaped irregular shaft portion 12d located on the opposite side in the axial direction from the tip shaft portion 12c of the large-diameter shaft portion 12b.

[0029] The irregularly shaped shaft portion 12d of the pinion shaft 12 has a roughly oval cross-section, with a pair of two-sided width portions 21d, 21d arranged opposite each other almost parallel to each other (inclined at a predetermined angle so as to narrow toward the outer diameter side of the arc) with respect to the rotation center Z of the pinion shaft 12, and a pair of two-sided width connecting portions (a pair of arc-shaped portions 21f, 21f) connecting the ends of the pair of two-sided width portions 21d, 21d, and a pair of restricting portions 21e, 21e that protrude radially outward from the pair of two-sided width connecting portions to restrict the axial movement of the pinion shaft 12. Furthermore, in the axial direction of the pinion shaft 12, the portion that does not have the pair of restricting portions 21e, 21e has a pair of arc-shaped portions 21f, 21f with the rotation center Z of the pinion shaft 12 as the center of curvature. The irregularly shaped shaft portion 12d and the large-diameter shaft portion 12b have roughly the same outer diameter and constitute the maximum diameter of the pinion shaft 12 as a whole. In addition, the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d function as acting parts that exert external force on the two sets of lock plates 14, 16.

[0030] The pair of restricting portions 21e, 21e of the pinion shaft 12 are positioned symmetrically across the rotation center Z of the pinion shaft 12, in the circumferential intermediate portion of the pair of arc-shaped portions 21f, 21f of the irregularly shaped shaft portion 12d, and are formed in a flattened (plate-like) shape extending along the radial direction. Furthermore, the pair of restricting portions 21e, 21e are offset in the axial direction towards the large-diameter shaft portion 12b, and this offset arrangement allows the drive wheel 18, which will be described later, to engage with the arc-shaped portions 21f, 21f remaining on the large-diameter shaft portion 12b side.

[0031] Furthermore, the pair of restricting portions 21e, 21e of the pinion shaft 12 each have a pair of generally flat axial sides that are almost parallel to each other, and are set to a generally constant thickness in their extending direction (radial direction). In addition, the axial end faces of this pair of restricting portions 21e, 21e are also generally parallel and flat, and the end face on the large-diameter shaft portion 12b side abuts against the inner bottom surface of the housing 11, thereby restricting the movement of the pinion shaft 12 inward (towards the seat) in the axial direction.

[0032] As shown in Figure 6, the pair of lock plates 14 of the brake mechanism 9 are arranged symmetrically from left to right or vertically, facing each other, so that they sit on the inner bottom surface of the housing 11 and the outer circumferential surfaces of both ends are in contact with the friction cylindrical surface 13, as also shown in Figure 7. Furthermore, another pair of lock plates 16 are placed on top of the pair of lock plates 14, facing each other in the axial direction of the pinion shaft 12, so as to be symmetrically from left to right or vertically. On the outer circumferential surfaces of these two pairs of lock plates 14 and 16, at both ends spaced apart with the recess 25 in between, arc-shaped braking lock surfaces 26 are formed that can contact the friction cylindrical surface 13 of the housing 11.

[0033] Furthermore, a lock spring 15 is interposed between the two ends (first ends) of one pair of lock plates 14 as a biasing means. That is, this lock spring 15 biases the two ends (first ends) of one pair of lock plates 14 in a direction that moves them apart from each other. Similarly, a lock spring 17 is interposed between the two ends (second ends) of another pair of lock plates 16 as a biasing means. That is, this lock spring 17 biases the two ends (second ends) of one pair of lock plates 16 in a direction that moves them apart from each other.

[0034] The lock springs 15 and 17 are of the so-called composite spring type, each consisting of leaf springs 15a and 17a bent into an approximately M shape, with coil springs 15b and 17b sandwiched between the ends of the legs of the leaf springs 15a and 17a, respectively. The recesses 15c and 17c of the approximately M-shaped leaf springs 15a and 17a are fitted into a pair of restricting parts 21e and 21e of the pinion shaft 12, respectively, as shown in Figure 7, and are supported by the pinion shaft 12 via the pair of restricting parts 21e and 21e. The coil springs 15b and 17b bias the legs of the leaf springs 15a and 17a in the direction of spreading apart.

[0035] In the brake mechanism 9 configured in this way, the pinion shaft 12 shown in Figure 6 is inserted so that the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d are positioned within the opposing gaps between one pair of lock plates 14 and the other pair of lock plates 16, as shown in Figures 5 and 7. Furthermore, the irregularly shaped shaft portion 12d is loosely fitted into the square hole 28a of the drive wheel 18, which will be described later, so as to allow rotation by a small angle.

[0036] As shown in Figure 7, a pair of release claws 29b of the drive wheel 18, which will be described later, are fitted into recesses 25 of each of the two sets of lock plates 14 and 16 on their outer circumferences, with a gap in the rotational direction of the pinion shaft 12. The arc-shaped outer surfaces of these release claws 29b are in a non-contact state with respect to the friction cylindrical surface 13 of the housing 11, with a gap of a predetermined width between them.

[0037] Furthermore, the axial dimensions are set such that the two sets of lock plates 14 and 16 are not pinched in the axial direction even when the release claw portion 29d contacts the inner bottom surface of the housing 11, thereby ensuring the operating space for the brake mechanism portion 9.

[0038] As shown in Figure 7, on the opposing end faces of a pair of lock plates 16 located on both sides of the irregularly shaped shaft portion 12d of the pinion shaft 12, arc-shaped protrusions 16a and 16b are formed at positions corresponding to two locations on the left and right of the rotation center of the irregularly shaped shaft portion 12d, where they face the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d. A lock spring 17 is interposed between the two ends (second ends) of this pair of lock plates 16, biasing them in a direction that moves them apart from each other.

[0039] Therefore, a pair of lock plates 16 rotate by a predetermined amount along the friction cylindrical surface 13 of the housing 11, so that the distance between the first ends of the lock plates 16 is smaller than the distance between the second ends of the lock plates 16. As a result, of the pair of protrusions 16a and 16b formed on the opposing end faces of this pair of lock plates 16, one protrusion 16b contacts one side of the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d, while the other protrusion 16a is spaced apart from the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d.

[0040] These relationships are also true for the other pair of lock plates 14 shown in Figure 6, where a lock spring 15 is interposed between the ends (first ends) of the pair of lock plates 14, biasing them in a direction that separates them from each other. Therefore, as will be described later, the two-sided width portions 21d, 21d that function as the acting parts of the irregularly shaped shaft portion 12d will be in rotational contact with the two pairs of lock plates 14, 16 without any gaps.

[0041] In addition, the two-sided width portions 21d, 21d of the pinion shaft 12 shown in Figure 7 are set as tapered surfaces that are inclined towards both the upper and lower ends, with the central part in the vertical direction of the figure as the apex. However, the two-sided width portions 21d, 21d may also be simple flat surfaces without inclination.

[0042] Figure 9 is a front view of the drive wheel 18 used in this embodiment, Figure 10 is a cross-sectional view of Figure 9 along line BB, Figure 11 is a perspective view of the drive wheel 18 used in this embodiment, Figure 12 is a perspective view of the cover member 22 used in this embodiment, and Figure 13 is a view taken along arrow C in Figure 5, showing the wedge cam 19 and fixing bolt 32 used in this embodiment. Figure 14 is a front view of the drive mechanism 10 with the lever bracket 24 and cover member 22 of this embodiment removed.

[0043] As shown in Figures 6, the drive wheel 18 of the drive mechanism 10 has a disc-shaped drum portion 28 having a square hole 28a in the center and an annular outer ring portion 28b on its outer circumference, and a resin portion 29 formed to cover the inner bottom and outer circumference of the drum portion 28.

[0044] The drum portion 28 is formed in a shallow dish shape by press-forming an iron-based metal sheet, and a rectangular hole 28a is formed axially through the center so that the irregularly shaped shaft portion 12d of the pinion shaft 12 can be fitted into it, allowing it to rotate integrally with the pinion shaft 12. The drum portion 28 also has an annular flange outer ring portion 28b integrally provided on its outer circumference, and the inner circumferential surface 28c of the outer ring portion 28b is formed in a perfect circle. This inner circumferential surface 28c functions as a friction surface that presses against the outer circumferential surfaces of multiple rollers 20 via a wedge cam 19, which will be described later, and applies a wedge friction force. The drum portion 28 also has two through holes 28d on either side of the rectangular hole 28a, and these through holes 28d are used as fixing parts for integration when insert-molding the resin portion 29.

[0045] The resin part 29 is formed on the outer surface, inner bottom, and outer circumferential surface of the outer ring part 28b of the drum part 28 using a synthetic resin material such as PA66 nylon by a method such as so-called insert molding, and the outer circumferential part 29a is formed in an annular shape that covers the outer ring part 28b.

[0046] On the rear side of the drive wheel 18, that is, on the rear side of the outer circumference 29a of the resin part 29, a pair of arc-shaped release claws 29b are integrally formed, projecting toward the two sets of lock plates 14 and 16. Therefore, each of these release claws 29b is formed as part of the resin part 29.

[0047] Furthermore, a friction resistance portion 30 is provided on the outer circumference 29a of the resin portion 29, which is formed to cover the outer ring portion 28b of the drum portion 28, on the outer circumference side of the drive wheel 18, and is positioned to face the friction cylindrical surface 13 of the housing 11 from the radial direction.

[0048] As shown in Figures 9 to 11, each friction resistance portion 30 is provided in four positions at approximately 90° equal intervals in the circumferential direction of the outer peripheral portion 29a of the resin portion 29. Each friction resistance portion 30 is formed in a rising, inclined shape from the housing 11 side toward the lever bracket 24, and is also formed in an arc shape of a predetermined length along the circumferential direction of the outer peripheral portion 29a. Furthermore, each friction resistance portion 30 is formed in a rising, inclined shape toward the lever bracket 24, and an arc-shaped gap portion 31 is formed between its inner surface 30a and the outer peripheral surface of the outer ring portion 28b of the drum portion 28.

[0049] Each of these gaps 31 has an opening 31a on the lever bracket 24 side due to the upward-rising structure of each friction resistance part 30 toward the lever part, allowing radial elastic deformation of the friction resistance part 30 and applying spring force to the friction resistance part 30. When the drive wheel 18 is housed inside the housing 11, insertion is improved, and each outer surface of each friction resistance part 30 is elastically pressed radially against the friction cylindrical surface 13.

[0050] Furthermore, there is a predetermined amount of play in the rotational direction between the square hole 28a of the drive wheel 18 and the irregularly shaped shaft portion 12d of the pinion shaft 12.

[0051] The cover member 22 of the drive mechanism 10 shown in Figure 6 is formed in a substantially disc shape from a metal plate, for example, by pressing, as also shown in Figure 12. This cover member 22 has three claw portions 22a at 120° angular positions in the circumferential direction on its outer edge, which engage with the locking recess 11c of the housing 11 when assembled with the housing 11, and a bifoliate-shaped insertion hole 22b is formed through the center in the axial direction.

[0052] As shown in Figures 2 and 4, the three claw portions 22a are fitted into the locking recess 11c of the housing 11, and then their tips are crimped and crushed to fix the cover member 22 to the housing 11. The fitting hole 22b has three fan-shaped holes 22e formed at 120° positions on the inner periphery of the central hole, which allow rotation of the three projections 19e of the fitting projection 19c of the wedge cam 19, which will be described later.

[0053] Furthermore, as shown in Figures 3, 6, and 12, the cover member 22 has three protrusions 22c on one side facing the lever bracket 24, positioned to correspond to each of the claw portions 22a. These three protrusions 22c are located within the three window holes 24d of the lever bracket 24, which will be described later. In addition, the cover member 22 has three protruding pieces 22d projecting toward the wedge cam 19 at 120° circumferential positions between the protrusions 22c. These three protruding pieces 22d are formed by cutting and bending a portion of the peripheral wall of the cover member 22, and are bent at approximately a right angle toward the wedge cam 19 relative to the peripheral wall of the cover member 22, and are positioned between two rollers 20a and 20b, which will be described later, among the multiple rollers 20. Each protruding piece 22d is designed to restrict the rotational movement of either one of the rollers 20a or 20b during the rotation of the wedge cam 19.

[0054] The wedge cam 19 of the drive mechanism 10 shown in Figure 6 is formed in a disc shape, as shown in Figures 13 and 14, and is approximately circular when viewed from the front. It has three radially outwardly protruding cam portions 19a at 120° positions in the circumferential direction. Therefore, when this wedge cam 19 is positioned between the drive wheel 18 and the cover member 22, the protruding pieces 22d of the cover member 22 (dotted lines in Figure 14) are positioned in the wedge-shaped gap formed between the inner circumferential surface of the outer ring portion 28b of the drive wheel 18 and the outer circumferential surface of each cam portion 19a.

[0055] Furthermore, the wedge cam 19 has a bolt insertion hole 19b formed axially through its central position, through which the shaft portion 32b of the fixing bolt 32 (described later) is inserted, and a substantially triangular fitting projection 19c is integrally provided on the outer surface on the lever bracket 24 side. This fitting projection 19c has three protrusions 19e extending radially from the outer circumference of the central part by press working, and protrudes to the outside through the fitting hole 22b of the cover member 22, fitting into the fitting groove portion 24c of the lever bracket 24 (described later) with a gap. As a result, the wedge cam 19 can rotate integrally with the lever bracket 24.

[0056] Furthermore, as shown in Figure 13, the wedge cam 19 has a recess 19d formed on the opposite side, that is, in the center of the inner surface on the cover member 22 side, as a result of press forming the fitting projection 19c into a convex shape. This recess 19d is formed in a roughly triangular shape in the center, corresponding to the fitting projection 19c, and the three outer surfaces 32d of the head 32a face each other with a small gap between them, and the head 32a is housed within the recess 19d while engaging with it. In this way, the three inner surfaces 19f of the recess 19d function as a rotation prevention mechanism for the fixing bolt 32.

[0057] The six rollers 20 of the drive mechanism 10 shown in Figure 6 are each made of metal and have the same outer diameter and axial length. As shown in Figure 14, two rollers are arranged on each side of each cam portion 19a of the wedge cam 19. As previously mentioned, the protruding pieces 22d of the cover member 22 are positioned axially between these two closely spaced pairs of rollers 20a and 20b. Therefore, the left and right rollers 20a and 20b are positioned within the gap between the outer circumferential surface of each cam portion 19a and the inner circumferential surface 28c of the drive wheel 18, sandwiching each protruding piece 22d. As the wedge cam 19 rotates, the outer surfaces of each cam portion 19a are pressed against each other, creating a wedge effect.

[0058] The three roller biasing springs 23 of the drive mechanism 10 shown in Figure 6 are composed of axially long coil springs, as shown in Figure 14. They are positioned between adjacent cam portions 19a of the wedge cam 19 in the circumferential direction along the inner circumferential surface of the outer ring portion 28b of the drive wheel 18, and both axial ends of each spring elastically contact an adjacent pair of rollers 20a and another pair of rollers 20b from the circumferential direction, biasing each roller 20a and 20b in the direction of the corresponding cam portion 19a.

[0059] As a result, when the operating lever 5 shown in Figure 1 is rotated from the neutral position in either the forward or reverse direction, the cam portion 19a of the wedge cam 19 rotates the drive wheel 18 integrally via one of the rollers 20a or rollers 20b. Then, when the operating force is released, the biasing force of the roller biasing springs 23 causes the wedge cam 19, lever bracket 24, and operating lever 5 to return to the neutral position, leaving the drive wheel 18 in that position, via the rollers 20a or rollers 20b. This will be explained in detail in the following section on the function of the brake device.

[0060] As shown in Figure 6, the lever bracket 24 of the drive mechanism 10 is formed from a metal material into a disc shape by press molding, as shown in Figures 2 to 5. Two screw insertion holes 24a are formed on the outer circumference for inserting screws that connect to the operating lever 5. The lever bracket 24 also has a bolt hole 24b formed axially through the center, through which the shaft portion 32b of the fixing bolt 32 is inserted.

[0061] Furthermore, the lever bracket 24 has a fitting groove 24c formed by press molding around the bolt hole 24b, into which the fitting projection 19c of the wedge cam 19 fits from the axial direction. The fitting groove 24c is formed to have the same outer shape as the fitting projection 19c, and the entire fitting projection 19c fits snugly inside, creating a unified structure between the lever bracket 24 and the wedge cam 19, thereby efficiently transmitting the rotational force of the lever bracket 24 to the wedge cam 19.

[0062] Furthermore, the lever bracket 24 has three arc-shaped window holes 24d formed through its outer circumference at equally spaced positions of 120° in the circumferential direction. Three protrusions 22c of the cover member 22, which is engaged with the inside, pass through each of these window holes 24d, and these three protrusions 22c restrict the range of rotation of the lever bracket 24 when it is rotated in the forward or reverse direction.

[0063] As shown in Figures 2 to 6 and Figure 13, the fixing bolt 32 is a general hexagonal bolt having a hexagonal head 32a and a shaft portion 32b with male threads 32c formed on its outer circumference. The shaft portion 32b passes through the bolt insertion hole 19b of the wedge cam 19 and the bolt hole 24b of the lever bracket 24, and a nut 33 is fastened to the tip of the penetrating shaft portion 32b to fasten and fix the wedge cam 19 to the lever bracket 24. As shown in Figure 5, the axial length (height) of the head 32a is formed to be smaller than the groove depth of the recess 19d of the wedge cam 19, so that when fitted into the recess 19d, the head 32a does not protrude from the recess 19d and the entire head is housed within the recess 19d. Furthermore, when the head 32a is fitted (engaged) into the recess 19d, the three outer surfaces 32d engage with the three corresponding inner surfaces 19f of the recess 19d with gaps in between.

[0064] The nut 33 is also a typical hexagonal nut, with an internal female screw hole 33a into which the male thread 32c at the tip of the shaft is screwed, and the external surface 33b is formed in a hexagonal shape that can be held in place with a socket wrench or the like.

[0065] (Brake system function) The functions of the brake system 7 configured as described above are as follows:

[0066] When the operating lever 5 is not rotated together with the lever bracket 24 in the position shown in Figure 3, the wedge cam 19 is held in a neutral position together with each roller 20 by the biasing force of the roller biasing spring 23, as shown in Figures 3 and 14.

[0067] In other words, in the neutral state shown in Figures 3 and 14, the wedge cam 19 in the drive mechanism 10 is also in its initial neutral position due to the spring force of the roller biasing springs 23 via each roller 20, and therefore the drive wheel 18 is held in its initial rotational position as shown in Figure 14.

[0068] Simultaneously, as shown in Figure 7, in the brake mechanism 9, one of the protrusions 16a and 16b of each of the two sets of lock plates 14 and 16, each biased by lock springs 15 and 17, presses against the two-sided width portions 21d and 21d of the pinion shaft 12, while the braking lock surfaces 26 at both ends press against the friction cylindrical surface 13 of the housing 11. As a result, the pinion shaft 12 is prevented from rotating in both the forward and reverse directions, and maintains its braking state through the frictional force between the two (the braking lock surfaces 26 of each lock plate 14 and 16 and the friction cylindrical surface 13 of the housing 11).

[0069] In this case, even if a reverse input is applied to the brake device 7 from the seat lifter mechanism side due to the occupant's seating, the braking state can be maintained by the frictional force between the friction cylindrical surface 13 of the housing 11 and the braking lock surfaces 26 of the two sets of lock plates 14 and 16. Thus, in the brake mechanism 9, the friction cylindrical surface 13 of the housing 11 and the two sets of lock plates 14 and 16, including the lock springs 15 and 17, function as direct braking elements.

[0070] On the other hand, when adjusting the height position using the seat lifter mechanism as described above, in order to release the braking state of the brake mechanism 9 in the brake device 7, the lever bracket 24 of the drive mechanism 10 is rotated in the forward or reverse direction together with the operating lever 5 shown in Figure 1.

[0071] Let's consider the case where the lever bracket 24, together with the operating lever 5, is rotated in either the forward or reverse direction from the neutral position of the drive mechanism 10 shown in Figures 3 and 14, for example, clockwise from the state shown in Figure 3.

[0072] Figure 15 shows the lever bracket 24 in this embodiment rotated clockwise from the neutral position, where (a) is a front view seen from the lever bracket 24 side, (b) is a front view of the drive mechanism 10 with the lever bracket 24 and cover member 22 removed, and (c) is a front view of the drive wheel 18 with the drive mechanism 10 removed.

[0073] As shown in Figure 15(a), when the lever bracket 24 is rotated clockwise (in the direction of the arrow) by the operating lever 5, the wedge cam 19 of the drive mechanism 10 also rotates integrally in the same direction, as shown in Figure 14(b). As a result, each cam portion 19a rotates one of the three rollers 20a clockwise against the spring force of each roller biasing spring 23. Then, due to the wedge effect of the rotation of each cam portion 19a, the outer surface of each roller 20a presses against the inner surface 28c of the outer ring portion 28b of the drum portion 28 of the drive wheel 18, causing the drive wheel 18 to rotate clockwise as well. In other words, the drive wheel 18 is rotated clockwise by the wedge effect of each roller 20a.

[0074] At this time, the other three rollers 20b are restricted from rotating by the three protruding pieces 22d (dummy lines) of the cover member 22 which is fixed via the housing 11, as shown in Figure 15(b), and are only pressed by the spring force of the compressed roller biasing springs 23.

[0075] The drive wheel 18, which is rotationally driven by the wedge effect between the wedge cam 19 and each roller 20a, first releases the rotation restriction on the pinion shaft 12 by the two sets of lock plates 14 and 16. That is, as the drive wheel 18 rotates clockwise, the two release claws 29b shown in Figure 7 rotate their respective lock plates 14 and 16 in the same direction. As a result, the clamping of the two-sided width portions 21d, 21d of the pinion shaft 12 by the two sets of lock plates 14 and 16 is released, and the braking state of the brake mechanism 9 is effectively released. With this release of the braking state, the pinion shaft 12 becomes rotatable relative to the housing 11 together with the two sets of lock plates 14 and 16.

[0076] Next, as shown in Figure 15(c), the rotation of the pinion shaft 12 by the drive wheel 18 pushed by each roller 20a occurs after it has rotated by a predetermined amount of play provided between the square hole 28a and the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d on the pinion shaft 12 side. The contact between the square hole 28a and the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d causes the pinion shaft 12 to rotate clockwise from the position shown in Figure 7. This rotation of the pinion shaft 12 is none other than the rotation of the pinion gear 12a, and this rotation of the pinion gear 12a causes the driven gear of the seat shifter mechanism (not shown) that meshes with the pinion gear 12a to rotate, causing the height position of the seat 1 to be displaced, for example, to a higher position.

[0077] As is clear from the above explanation, the vertical displacement of the seat 1 in Figure 1, based on the function of the seat lifter mechanism, is small compared to the amount of rotation of the operating lever 5. Therefore, in most cases, the rotation of the operating lever 5 will need to be repeated multiple times.

[0078] When the operating force of the operating lever 5 is released, the restorative force of the roller biasing springs 23 causes the operating lever 5, as well as the rollers 20a and wedge cams 19 of the drive mechanism 10, to rotate back from the state shown in Figure 15(b) to the initial neutral position shown in Figure 14.

[0079] At this time, each protruding piece 22d of the cover member 22 restricts each roller 20a from rotating beyond the neutral position. As a result, each cam portion 19a of the wedge cam 19 and each roller 20b do not come into contact, and the rotation of the wedge cam 19 is not transmitted to the drive wheel 18. Therefore, the drive wheel 18 remains in the position it rotated to earlier via each friction resistance portion 30, and the wedge cam 19 and roller 20a rotate back to the initial state shown in Figure 14 without rotation of the drive wheel 18 and the pinion shaft 12.

[0080] Figure 16 shows the lever bracket in this embodiment rotated counterclockwise from the neutral position, where (a) is a front view seen from the lever bracket side, (b) is a front view of the drive mechanism with the lever bracket and cover member removed, and (c) is a front view of the drive wheel with the drive mechanism removed.

[0081] Next, we will describe the case where the lever bracket 24 is rotated in the reverse direction (counterclockwise) together with the operating lever 5 from the neutral position of the drive mechanism 10 shown in Figure 14.

[0082] As shown in Figure 16(a), as the lever bracket 24 rotates counterclockwise (in the direction of the arrow), the wedge cam 19 of the drive mechanism 10 also rotates in the same counterclockwise direction, as shown in Figure 16(b). Each cam portion 19a then rotates the other three rollers 20b counterclockwise against the spring force of the roller biasing springs 23. As the wedge cam 19 rotates, the outer circumferential surfaces of each roller 20b are pressed against the inner circumferential surface 28c of the drum portion 28 of the drive wheel 18 by each cam portion 19a, creating a wedge effect and causing the drive wheel 18 to rotate counterclockwise as well. At this time, the rotation of one of the three rollers 20a is restricted by the three protruding pieces 22d via the housing 11, and they are pressed against the protruding pieces 22d by the spring force of the compressed roller biasing springs 23.

[0083] When the drive wheel 18 is driven to rotate counterclockwise, it first releases the restriction on the rotation of the pinion shaft 12 by the two sets of lock plates 14 and 16. That is, as the drive wheel 18 rotates counterclockwise from the position shown in Figure 7, the two release claws 29b, 29b cause each of the lock plates 14 and 16 to rotate in the same direction, opposite to the previous direction. As a result, the clamping of the two-sided width portions 21d, 21d of the pinion shaft 12 by the two sets of lock plates 14 and 16 is released, and the braking state of the brake mechanism 9 is effectively released. With this release of the braking state, the pinion shaft 12 becomes rotatable relative to the housing 11 together with the two sets of lock plates 14 and 16.

[0084] Next, the rotation of the pinion shaft 12 by the drive wheel 18 pushed by each roller 20b occurs after it has rotated by a predetermined amount of play provided between the square hole 28a and the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d on the pinion shaft 12 side, as shown in Figure 16(c). The contact between the square hole 28a and the two-sided width portions 21d, 21d of the irregularly shaped shaft portion 12d causes the pinion shaft 12 to rotate in the counterclockwise direction shown in Figure 7. As a result, the counterclockwise rotation of the pinion gear 12a causes the driven gear of the seat shifter mechanism (not shown) that meshes with the pinion gear 12a to rotate, and the height position of the seat 1 is displaced, for example, to the lower side.

[0085] When the operating force of the operating lever 5 is released, the restorative force of each roller biasing spring 23 causes the operating lever 5, as well as each roller 20a and wedge cam 19 of the drive mechanism 10, to rotate back to the initial neutral position shown in Figure 14 from the state shown in Figure 16(c). Here, the cam portions 19a of the wedge cam 19 and each roller 20a do not come into contact, and the rotation of the wedge cam 19 is not transmitted to the drive wheel 18. Therefore, the drive wheel 18 remains in the position it rotated to earlier via each friction resistance portion 30, and the wedge cam 19 and roller 20a rotate back to the initial state shown in Figure 14 without rotation of the drive wheel 18 or the pinion shaft 12.

[0086] (Effects of this embodiment) Furthermore, since the drive wheel 18 is provided with friction resistance portions 30 that are constantly pressed against the friction cylindrical surface 13 of the housing 11 by elastic spring force at four positions on its outer circumference 29a, the following effects can be obtained.

[0087] In other words, as described above, when the lever bracket 24 is rotated in the forward or reverse direction together with the operating lever 5 from the neutral position of the drive mechanism 10 to a braking state where the wedge cam 19 etc. are in the forward or reverse rotation position, and then the operation of the operating lever 5 is released to return to the neutral position, the drive wheel 18 has four friction resistance parts 30 that elastically contact the friction cylindrical surface 13 of the housing 11, so the occurrence of rotation together with the wedge cam 19 is suppressed.

[0088] In other words, when the operation of the operating lever 5 (lever bracket 24) is released, the wedge action of either one of the rollers 20a or rollers 20b is released, and the wedge cam 19 returns to the neutral rotation position due to the biasing force of the roller biasing springs 23. At this time, the cam portion 19a and the other roller 20a or roller 20b do not come into contact, but one of the rollers 20a or rollers 20b is pressed against the cam portion 19a due to the biasing force of the roller biasing springs 23. As a result, a small frictional resistance is generated between one of the rollers 20a or rollers 20b and the drive wheel 18, and this frictional resistance causes the drive wheel 18 to rotate to the same neutral position. However, because the outer surfaces of each friction resistance portion 30 of the drive wheel 18 are pressed elastically against the friction cylindrical surface 13 of the housing 11, sufficient frictional force for braking is generated between the drive wheel 18 and the housing 11, thus suppressing the occurrence of rotation together with the wedge cam 19. Therefore, stable and reliable operation of the seat lifter mechanism by the operating lever 5 can be obtained.

[0089] Furthermore, since the friction resistance parts 30 are provided in four positions at 90° intervals in the circumferential direction, a sufficient and stable frictional force can be secured against the friction cylindrical surface 13 of the housing 11, and as a result, the occurrence of the drive wheel 18 rotating together can be further suppressed.

[0090] Moreover, because the rotation of the drive wheel 18 is suppressed in this way, the friction resistance parts 30 are simply integrated into the drive wheel 18, eliminating the need to provide a separate component such as a wave washer between the brake housing and the drive wheel, as in conventional technology. This reduces the number of parts, thereby improving manufacturing efficiency and lowering operating costs.

[0091] Furthermore, the friction resistance portion 30 of the drive wheel 18 can be formed together with the outer peripheral portion 29a of the resin portion 29 when the resin portion 29 is molded onto the drum portion 28, thus further improving manufacturing efficiency.

[0092] Furthermore, since a gap 31 is formed inside each friction resistance portion 30 to impart elastic spring force to the friction resistance portion 30, it becomes possible to elastically press the friction resistance portion 30 against the friction cylindrical surface 13. As a result, a stable frictional force of the drive wheel 18 against the housing 11 can be obtained stably over a long period of time.

[0093] Since the gap 31 has an opening 31a on one side in the axial direction, the elastic deformation of the friction resistance portion 30 becomes easier compared to the case where there is no opening 31a, allowing it to make more flexible elastic contact with the friction cylindrical surface 13.

[0094] Furthermore, in this embodiment, since the release claw portion 29b for releasing the braking state of the pinion shaft 12 is integrally provided on the resin portion 29 of the drive wheel 18, it can be molded together during resin molding, thereby improving manufacturing efficiency and reducing work costs compared to when they are provided as separate parts.

[0095] In this embodiment, by forming a simple bolt insertion hole 19b in the wedge cam 19 instead of an internal screw hole, machining of the internal screw hole is unnecessary, and the wedge cam 19 can be formed by press working alone. Therefore, the forming process of the wedge cam 19 itself is simplified, improving manufacturing efficiency and reducing manufacturing costs. In other words, the bolt insertion hole 19b can be formed together with the press forming of the wedge cam 19. Therefore, complicated machining other than press working is unnecessary, resulting in improved manufacturing efficiency.

[0096] Furthermore, since the recess 19d of the wedge cam 19 functions as an anti-rotation mechanism for the fixing bolt 32 when tightening the nut 33, a separate anti-rotation mechanism for the fixing bolt 32 is unnecessary, which is also advantageous in terms of manufacturing costs.

[0097] Furthermore, since the wedge cam 19 can be formed together with the recess 19d, which functions as an anti-rotation mechanism for the head 32a of the fixing bolt 32, by the same press working process, the overall formability of the wedge cam 19 is further improved, and the reduction of manufacturing costs can be promoted. In particular, as mentioned above, since the recess 19d is formed as a result of forming the fitting projection 19c by press working, the forming work is easier compared to when it is formed separately. Moreover, the recess 19d makes it possible to effectively utilize the dead space on the outer surface of the wedge cam 19.

[0098] Furthermore, since the lever bracket 24 and the wedge cam 19 can be connected using readily available, inexpensive fixing bolts 32 and nuts 33, manufacturing costs can be reduced in this respect as well.

[0099] Furthermore, in the brake device 7 according to this embodiment, the bolt insertion hole 19b of the wedge cam 19 and the shaft portion 32b of the bolt 32 are assembled in a loosely fitted state, but they may also be fixed by light press-fitting. For example, as shown in Figure 17, the inner surface of the bolt insertion hole 19b of the wedge cam 19 may be made into a gear shape or tooth shape with irregularities, and a non-threaded shaft portion may be provided at the connection point (root) between the shaft portion 32b of the bolt 32 and the head 32a, and this shaft portion may be lightly press-fitted into the gear-shaped or tooth-shaped bolt insertion hole.

[0100] Alternatively, as shown in Figure 18, the head 32a of the bolt 32 can be lightly press-fitted into the three inner surfaces 19f of the recess 19d of the wedge cam 19 in a tight fit, without any gap between the three outer surfaces 32d and the three inner surfaces 19f of the recess 19d.

[0101] Furthermore, in another embodiment, an elastic member (for example, an O-ring made of rubber or resin) may be interposed between the bolt insertion hole 19b of the wedge cam 19 and the shaft portion 32b of the bolt 32, and the bolt may be lightly press-fitted.

[0102] In each of these embodiments, for example, shown in Figure 18, when assembling the components, if the hexagonal head 32a of the fixing bolt 32 is inserted axially into the recess 19d of the wedge cam 19, the three outer surfaces 32d of the head 32a of the fixing bolt 32 are lightly press-fitted and locked into the opposing inner surfaces 19f of the triangular recess 19d. As a result, the fixing bolt 32 is held in a stable, temporary fixing state with no looseness in the recess 19d of the wedge cam 19. Therefore, since the fixing bolt 32 and the wedge cam 19 are integrated, subsequent operations such as inserting the bolt into the bolt hole 24b of the lever bracket 24 and tightening the nut 33 become easier, resulting in a smoother assembly process.

[0103] Furthermore, the same effects and advantages as those of the embodiment shown in Figure 18 can be obtained in the embodiment shown in Figure 17, as well as when an elastic member is interposed between the bolt insertion hole 19b and the shaft portion 32b.

[0104] The present invention is not limited to the configuration of the above embodiment. For example, an elastic member, such as a soft rubber or resin material, can be interposed between the recess 19d of the wedge cam 19 and the head 32a of the fixing bolt 32 to prevent rattling. As in the case of light press-fitting, the head 32a of the fixing bolt 32 is prevented from rattling in the recess 19d by the elastic member, resulting in a stable temporary fastening state, which facilitates the assembly of the wedge cam 19 and the lever bracket 24.

[0105] Furthermore, although the brake device 7 according to this embodiment has a brake mechanism 9 using two sets of lock plates 14 and 16, it can also be applied to brake devices having a brake mechanism using multiple rollers. [Explanation of Symbols]

[0106] 5…Operating lever (operating component) 7…Brake system 8…Mounting bracket 9... Brake mechanism 10…Drive mechanism 11…Housing (Brake Housing) 11a…Shaft hole 12... Pinion shaft (output shaft) 12a... Pinion gear (drive gear) 12b...Large diameter shaft section 12c…Irregular shaft part 14, 16… Lock Plate 15, 17... Lock spring 18…Drive wheel 19...Kusabi Kam 19a... Cam section 19b... Bolt insertion hole 19c…Mating protrusion 19d…recess 19f…Three inner aspects 20, 20a, 20b... Laura 22... Cover component 23... Roller-equipped spring 24... Lever bracket 24b... Bolt hole 32… Fixing bolts (bolts) 32a...Head 32b...Shaft part 32c... Male screw 32d... Three exterior surfaces 33... Nut

Claims

1. A brake device comprising: a brake mechanism provided on a seat adjuster of a vehicle seat, including a drive-side gear provided at one end of the output shaft, which puts the output shaft in a braking state so as not to rotate in response to a reverse input from the drive-side gear; and a drive mechanism that releases the braking state of the output shaft and allows the output shaft to rotate in either the forward or reverse direction when the operating member is rotated from the neutral position in either the forward or reverse direction, wherein the brake mechanism and the drive mechanism are arranged coaxially with each other, The drive mechanism comprises a lever bracket, a wedge cam that rotates integrally with the lever bracket, and a bolt and nut that integrally connect the lever bracket and the wedge cam. The lever bracket has a bolt hole through which the shaft of the bolt is inserted in a through state, The wedge cam has a bolt insertion hole through which the shaft of the bolt can be inserted, and a recess into which the head of the bolt can be fitted while its rotation is restricted. A brake device for a vehicle seat, characterized in that the shaft portion of the bolt has a male threaded portion formed on its outer circumference, and the lever bracket and the wedge cam are rotatably coupled together by fastening the nut to the tip portion which penetrates the bolt insertion hole and the bolt hole of the lever bracket.

2. A brake device for a vehicle seat according to claim 1, The recess of the wedge cam is formed in a roughly triangular shape, while the head of the bolt is formed in a hexagonal shape. A brake device for a vehicle seat, characterized in that the rotation of the bolt is restricted by locking at three points on the outer surface of the head opposite the inner surface of the substantially triangular recess.

3. A brake device for a vehicle seat according to claim 2, A brake device for a vehicle seat, characterized in that the shaft portion of the bolt is passed through the bolt insertion hole of the wedge cam by light press-fitting from the axial direction.

4. A brake device for a vehicle seat according to claim 2, A brake device for a vehicle seat, characterized in that the head of the bolt is lightly press-fitted into the recess of the wedge cam from the axial direction.

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