Brake system for vehicle seats

Abstract

To provide a brake device for vehicle seats that reduces the number of parts, thereby improving manufacturing efficiency and lowering manufacturing costs. [Solution] The system includes a brake mechanism 9 that brakes the pinion shaft 12 to prevent it from rotating in response to reverse input from the pinion gear 12a, and a drive mechanism 10 that releases the braking state of the pinion shaft and allows it to rotate in either the forward or reverse direction when the operating lever 5 is rotated from the neutral position in either the forward or reverse direction. The brake mechanism has a housing 11 with a friction cylindrical surface 13 on its inner circumference, and the drive mechanism has a drive wheel 18 that rotates the operating lever and the pinion shaft together while releasing the braking state of the pinion shaft. The drive wheel has friction resistance parts 30 at four locations in the circumferential direction that are pressed against the friction cylindrical surface of the housing by elastic force.

Description

Technical Field

[0001] The present invention relates to a brake 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 brake device for this type of vehicle seat, for example, the one described in Patent Document 1 below has been proposed.

[0003] The brake 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 rotation direction input to an operating lever to an output shaft via an input-side clutch and an output-side clutch, and outputs it to the vehicle seat.

[0004] In the input-side clutch, a disk-shaped wedge cam, which is an input-side inner ring member, is accommodated and arranged inside an input-side outer ring member, and a wave washer, which is a rotation suppression member, is provided in a pressure contact state between the input-side outer ring member and a release bracket.

[0005] When the rotational operation of the operating lever is released and returned to the neutral position, it becomes easy for rotation to occur between the input-side outer ring member and the housing due to the rotational return force from the wedge cam, but the rotation of the input-side outer ring member is suppressed by the biasing force of the wave washer. That is, the wave washer suppresses the rotation of the input-side outer ring member by applying a biasing force that axially presses the wedge cam against the input-side outer ring member with respect to the housing.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] However, the brake device described in Patent Document 1 requires the separate provision of a wave washer to suppress the rotation of the input-side outer ring member. This leads to an increase in the number of parts, as well as deterioration of manufacturing efficiency and a rise in manufacturing costs.

[0008] This invention has been made in view of the technical problems of the prior art described above, and provides a brake device for a vehicle seat that can reduce the number of parts, thereby improving manufacturing efficiency and lowering manufacturing costs. [Means for solving the problem]

[0009] The brake device for a vehicle seat according to the present invention is provided on the seat adjuster of the vehicle seat and includes 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 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 brake mechanism has a brake housing on which a friction cylindrical surface is formed on the inner circumferential surface. The drive mechanism is located inside the brake housing and has a drive wheel that rotates the operating member and the output shaft together while releasing the braking state of the output shaft. The drive wheel is characterized in that it has frictional resistance portions on its outer circumference that are pressed against the friction cylindrical surface of the brake housing by elastic force at least at three locations in the circumferential direction. [Effects of the Invention]

[0010] According to the present invention, it is possible to reduce the number of parts in a brake device, thereby improving manufacturing efficiency and lowering manufacturing costs. [Brief explanation of the drawing]

[0011] [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] Figure 2 is a perspective view of the brake system. [Figure 5] This is a cross-sectional view along line AA in Figure 3. [Figure 6] Figure 2 shows exploded perspective views of the components of the brake mechanism and drive mechanism in the brake system. [Figure 7] This is an explanatory diagram of the brake mechanism in its neutral state, with the drive mechanism removed. [Figure 8] This is a perspective view of the pinion shaft used in this embodiment. [Figure 9] This is a front view of the drive wheel used in this embodiment. [Figure 10] Figure 9 is a cross-sectional view along line BB. [Figure 11] This is a perspective view of the drive wheel used in this embodiment. [Figure 12] This is a perspective view of the cover member used in this embodiment. [Figure 13] This is a front view showing the drive mechanism of this embodiment with the lever bracket and cover member removed. [Figure 14] The lever bracket in this embodiment is shown 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 with the lever bracket and cover removed, and (c) is a front view of the drive wheel with the drive mechanism removed. [Figure 15]The figure shows the state where the lever bracket in this 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.

Mode for Carrying Out the Invention

[0012] 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.

[0013] FIG. 1 shows an example of a seat provided with a position adjustment structure.

[0014] 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 seat surface, and a reclining mechanism for adjusting the angle adjustment of a seat back 4 serving as a backrest. 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] And in the seat 1 shown in FIG. 1, when paying attention to the seat lifter mechanism, every 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 becomes higher, while conversely, every time the operation lever 5 is pushed downward from the neutral position, the position of the seat cushion 3 gradually becomes lower, and it has a known structure. Thereby, the height position adjustment function of the seat surface of the seat 1 is exhibited.

[0016] (Configuration of the Brake Device) Figure 2 is a right side view of the brake device according to the present invention, Figure 3 is a front view of the brake device shown in Figure 2, Figure 4 is a perspective view of the brake device shown in Figure 2, Figure 5 is a cross-sectional view along line AA in Figure 3, Figure 6 is an exploded perspective view of the components of the brake mechanism and drive mechanism in the brake device shown in Figure 2, Figure 7 is an explanatory diagram of the brake mechanism in a neutral state with the drive mechanism removed, and Figure 8 is a perspective view of the pinion shaft used in this 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 front view showing 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] As shown in Figure 6, the disc-shaped wedge cam 19 of the drive mechanism 10 is formed in a nearly circular shape when viewed from the front, and has three radially outwardly protruding cam portions 19a at 120° positions in the circumferential direction, as shown in Figure 13. 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 13) 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 female screw hole 19b formed through it axially at its central position, 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 its central part, protruding to the outside through the fitting hole 22b of the cover member 22, and fitting into the fitting groove 24c of the lever bracket 24, which will be described later. As a result, the wedge cam 19 can rotate integrally with the lever bracket 24.

[0056] 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 13, 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.

[0057] As shown in Figure 6, the three roller biasing springs 23 of the drive mechanism 10 are composed of axially long coil springs, and 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. The axial ends of each spring elastically contact an adjacent pair of rollers 20a and another pair of rollers 20b from the circumferential direction, respectively, biasing each roller 20a and 20b in the direction of the corresponding cam portion 19a.

[0058] 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.

[0059] As shown in Figures 2 to 5, the lever bracket 24 of the drive mechanism 10 in Figure 6 is formed from a metal material into a disc shape by press molding. Two screw insertion holes 24a are formed on the outer circumference for inserting screws that connect to the operating lever 5, and a bolt insertion hole 24b is formed in the center for inserting a fixing bolt 32. The fixing bolt 32 has a hexagonal head 32a and a shaft portion 32b with male threads formed on its outer circumference. The shaft portion 32b is inserted through the bolt insertion hole 24b and fastened to the female threaded hole 19b of the wedge cam 19, thereby fastening and fixing the wedge cam 19 to the lever bracket 24.

[0060] Furthermore, the lever bracket 24 has a fitting groove 24c formed by press molding around the bolt insertion 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.

[0061] 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.

[0062] (Brake system function) The functions of the brake system 7 configured as described above are as follows:

[0063] 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 13.

[0064] In other words, in the neutral state shown in Figures 3 and 13, 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 13.

[0065] 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).

[0066] 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.

[0067] 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.

[0068] Let's consider a scenario where the lever bracket 24, along 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 13, for example, clockwise from the state shown in Figure 3.

[0069] Figure 14 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.

[0070] As shown in Figure 14(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.

[0071] 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 14(b), and are only pressed by the spring force of the compressed roller biasing springs 23.

[0072] 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.

[0073] Next, as shown in Figure 14(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.

[0074] 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.

[0075] 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 14(b) to the initial neutral position shown in Figure 13.

[0076] 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 13 without rotation of the drive wheel 18 and the pinion shaft 12.

[0077] Figure 15 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.

[0078] 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 13.

[0079] As shown in Figure 15(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 15(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.

[0080] 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.

[0081] 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 15(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.

[0082] 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 13 from the state shown in Figure 15(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 13 without rotation of the drive wheel 18 or the pinion shaft 12.

[0083] (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.

[0084] 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.

[0085] 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 by 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, since the outer surface of each frictional resistance portion 30 of the drive wheel 18 is pressed elastically against the friction cylindrical surface 13 of the housing 11, a sufficient frictional force for braking is generated between it 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 achieved.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] The present invention is not limited to the configuration of the above embodiment. For example, at least three or more friction resistance portions 30 are provided on the outer peripheral portion 29a of the resin portion 29. In addition, in the above embodiment, the gap portion 31 provided inside the friction resistance portion 30 has an opening 31a on one side, but it is also possible to form a through-hole in the axial direction to provide openings on both sides.

[0093] In the brake device 7 according to this embodiment, the brake mechanism 9 uses two sets of lock plates 14 and 16, but as disclosed in the prior art documents, it can also be applied to brake devices having a brake mechanism using multiple rollers. [Explanation of symbols]

[0094] 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... Female screw hole 19c…Mating protrusion 20, 20a, 20b... Laura 22... Cover component 23... Roller-equipped spring 24…Lever bracket

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 brake mechanism has a brake housing on which a friction cylindrical surface is formed on the inner circumferential surface. The drive mechanism is located inside the brake housing and has a drive wheel that rotates the operating member and the output shaft together while releasing the braking state of the output shaft. The brake device for a vehicle seat adjuster is characterized in that the drive wheel has friction resistance portions on its outer circumference that press against the friction cylindrical surface of the brake housing at least three locations in the circumferential direction by elastic force.

2. In the brake device for a vehicle seat according to claim 1, The drive wheel comprises a disc-shaped metal drum portion having a cylindrical outer ring portion on its outer circumference, and a resin portion formed such that a part of it covers the outer surface of the outer ring portion of the drum portion. The brake device for a vehicle seat adjuster is characterized in that the resin portion has a friction resistance portion that elastically contacts the friction cylindrical surface of the brake housing from the radial direction while covering the outer peripheral surface of the outer ring portion on the outer peripheral side.

3. A brake device for a vehicle seat adjuster according to claim 2, A brake device for a vehicle seat adjuster, characterized in that a gap is provided between the outer ring portion of the drum portion and the friction resistance portion of the resin portion, which imparts a spring force to the friction resistance portion by radial elastic deformation.

4. A brake device for a vehicle seat adjuster according to claim 3, The brake device for a vehicle seat adjuster is characterized in that the gap portion is open on at least one side in the axial direction of the drive wheel.

5. A brake device for a vehicle seat adjuster according to claim 2, A brake device for a vehicle seat adjuster, characterized in that the resin portion of the drive wheel integrally has a release claw portion for releasing the braking state of the output shaft of the brake mechanism.

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