Resin bush and vehicle seat

Abstract

To inhibit occurrences of rattling and abnormal noise.SOLUTION: A resin bush 30 has a cylindrical part 30A which is formed in a non-circular cylindrical form when viewed in an axial direction. The cylindrical part 30A is sandwiched between an inner peripheral surface of a circular hole 26 formed at a component of a vehicle seat and an outer peripheral surface of a shaft 22 inserted into the circular hole 26 to be deformed elastically.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat, and more particularly to a resin bushing provided in a vehicle seat. [Background technology]

[0002] In the seat side armrest mounting structure disclosed in Patent Document 1 below, a resin bushing is interposed between the armrest frame and the pivot shaft, which is intended to suppress the generation of abnormal noise caused by friction between the armrest frame and the pivot shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-199964 Summary of the Invention [Problem to be solved by the invention]

[0004] In the prior art plastic bushings described above, clearances are provided between the armrest frame and the bushing and between the bushing and the pivot shaft to take into consideration ease of assembly of the armrest frame to the pivot shaft and resistance when the armrest frame rotates. If this clearance becomes large due to dimensional errors, rattles and abnormal noises may occur due to vibrations while the vehicle is running.

[0005] An object of the present invention is to provide a resin bushing and a vehicle seat that can suppress the generation of rattle and abnormal noise. [Means for solving the problem]

[0006] The resin bushing of the first embodiment has a tubular portion formed in a non-circular cylindrical shape when viewed from the axial direction, and the tubular portion is sandwiched between the inner surface of a circular hole formed in a component of the vehicle seat and the outer surface of a shaft inserted into the circular hole, thereby elastically deforming.

[0007] In the resin bushing of the first aspect, the tubular portion, which is formed in a non-circular tubular shape when viewed from the axial direction, is sandwiched between the inner circumferential surface of a circular hole formed in a component of the vehicle seat and the outer circumferential surface of a shaft inserted into the circular hole and elastically deforms. Multiple points on the outer circumferential surface of the tubular portion are pressed against the inner circumferential surface of the circular hole, and multiple points on the inner circumferential surface are pressed against the outer circumferential surface of the shaft. This makes it possible to suppress rattle and abnormal noise.

[0008] The resin bushing of the second aspect is the first aspect, wherein the cylindrical portion is formed in a substantially triangular cylindrical shape when viewed from the axial direction.

[0009] In the resin bushing of the second aspect, the cylindrical portion, which is formed into a generally triangular cylindrical shape when viewed from the axial direction, is sandwiched between the inner peripheral surface of the circular hole and the outer peripheral surface of the shaft and elastically deforms. Three points on the outer peripheral surface of this cylindrical portion are pressed against the inner peripheral surface of the circular hole, and three points on the inner peripheral surface are pressed against the outer peripheral surface of the shaft. This effectively suppresses the generation of rattles and abnormal noise.

[0010] The resin bushing of a third aspect is the first or second aspect, wherein the cylindrical portion has one or more slits extending in the axial direction.

[0011] In the resin bushing of the third embodiment, when the cylindrical portion is sandwiched between the inner surface of the circular hole and the outer surface of the shaft and elastically deforms, the change in the circumferential length of the cylindrical portion can be absorbed by the above-mentioned slits.

[0012] A fourth aspect of the vehicle seat comprises a component having a circular hole formed therein, a shaft inserted into the circular hole, and a resin bushing as described in claim 1 or claim 2, in which the tubular portion is sandwiched between the inner surface of the circular hole and the outer surface of the shaft.

[0013] In the vehicle seat of the fourth aspect, a shaft is inserted into a circular hole formed in a component, and the cylindrical portion of the resin bushing is sandwiched between the inner circumferential surface of the circular hole and the outer circumferential surface of the shaft. This resin bushing is one of the first to third aspects, and therefore the above-mentioned effects can be obtained. [Effects of the Invention]

[0014] As described above, the resin bushing and vehicle seat according to the present invention can suppress the occurrence of rattles and abnormal noises. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a side view showing a vehicle seat according to an embodiment; [Figure 2] 1 is a cross-sectional view showing a portion of a vehicle seat according to an embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing a cylindrical portion of the resin bushing according to the embodiment. [Figure 4] 10A and 10B are explanatory diagrams for explaining interference between the resin bush and the circular hole and the shaft. [Figure 5] FIG. 3 is a cross-sectional view showing a comparative example and corresponding to FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0016] A vehicle seat 10 according to one embodiment of the present invention will be described below with reference to Figures 1 to 4. Note that arrows FR, LH, and UP shown in Figures 1 and 2 indicate the front, left, and top of the vehicle seat 10, respectively.

[0017] 1, a vehicle seat 10 according to this embodiment includes a seat cushion 12 on which an occupant sits, a seatback 14 that supports the occupant's back, a headrest 16 that supports the occupant's head, and an armrest 18 that supports the occupant's arms. The armrest 18 is attached to the left side of the seatback 14, for example.

[0018] An armrest bracket 20 (see FIG. 2) is provided on the left side of the seat back 14. The bracket 20 is made of, for example, a press-formed metal plate, and is fixed to a frame (not shown) of the seat back 14. A shaft 22, which is a support shaft for the armrest 18, is fixed to the bracket 20.

[0019] The shaft 22 is made of, for example, a solid round metal bar, and has a stepped cylindrical shape with its axis extending in the left-right direction of the vehicle seat 10. The shaft 22 is fixed to the bracket 20 while passing through the bracket 20. A frame 24 of the armrest 18 is rotatably supported on the shaft 22. The frame 24 corresponds to the "component" in this invention.

[0020] A circular hole 26 having an axial direction that coincides with the left-right direction of the vehicle seat 10 is formed in the frame 24. The shaft 22 is inserted into this circular hole 26. The inner diameter of the circular hole 26 is set to be larger than the outer diameter of the shaft 22, and a resin bushing 30 is interposed between the inner peripheral surface of the circular hole 26 and the outer peripheral surface of the shaft 22.

[0021] The resin bushing 30 is made of a resin such as nylon and is formed into a stepped cylindrical shape with its axis extending in the left-right direction. The resin bushing 30 integrally includes a cylindrical portion 30A and a flange portion 30B that extends radially outward from one axial end of the cylindrical portion 30A in a flange-like shape. The flange portion 30B is disposed between the bracket 20 and the frame 24.

[0022] As shown in Fig. 3, the cylindrical portion 30A has a non-circular (here, approximately triangular) cylindrical shape when viewed in the axial direction. This approximately triangular cylindrical portion 30A has three vertices V1, V2, and V3 (reference numerals omitted in Fig. 4) arranged at 120-degree intervals (i.e., at equal intervals) in the circumferential direction. This cylindrical portion 30A is sandwiched between the inner circumferential surface of the circular hole 26 and the outer circumferential surface of the shaft 22, and is elastically deformed into a shape close to a cylinder. Note that hatching of the cross section of the cylindrical portion 30A is omitted in Fig. 4.

[0023] The diameter of the circumscribing circle of the cylindrical portion 30A is set to be larger than the diameter of the circular hole 26. Specifically, the cylindrical portion 30A is naturally shaped such that three locations OS1, OS2, and OS3 on the outer periphery, indicated by dots in FIG. 4, protrude radially outward from the circular hole 26. However, when the cylindrical portion 30A is inserted into the circular hole 26 and elastically deformed, the outer periphery surfaces of the three locations OS1, OS2, and OS3 strongly interfere with (are pressed against) the inner periphery surface of the circular hole 26. Furthermore, the diameter of the inscribing circle of the cylindrical portion 30A is set to be smaller than the diameter of the shaft 22. Specifically, the cylindrical portion 30A is naturally shaped such that three locations IS1, IS2, and IS3 on the inner periphery, indicated by dots in FIG. 4, protrude radially inward from the shaft 22. However, when the shaft 22 is inserted inside the cylindrical portion 30A and elastically deformed, the inner periphery surfaces of the three locations IS1, IS2, and IS3 strongly interfere with (are pressed against) the outer periphery surface of the shaft 22.

[0024] The three locations OS1, OS2, and OS3 that strongly interfere with the inner circumferential surface of the circular hole 26 are aligned at a pitch of 120 degrees in the circumferential direction of the cylindrical portion 30A. The three locations IS1, IS2, and IS3 that strongly interfere with the outer circumferential surface of the shaft 22 are aligned at a pitch of 120 degrees in the circumferential direction of the cylindrical portion 30A, and are arranged at a pitch that is offset by 60 degrees in the circumferential direction of the cylindrical portion 30A from the three locations OS1, OS2, and OS3.

[0025] The cylindrical portion 30A is formed with a plurality of (three in this example) slits 32 extending in the axial direction of the cylindrical portion 30A. The three slits 32 are aligned at a pitch of 120 degrees in the circumferential direction of the cylindrical portion 30A and are arranged at a pitch that is offset by 30 degrees in the circumferential direction of the cylindrical portion 30A from the three locations OS1, OS2, OS3 and the three locations IS1, IS2, IS3. These slits 32 divide the cylindrical portion 30A into three parts.

[0026] When the cylindrical portion 30A is sandwiched between the inner peripheral surface of the circular hole 26 and the outer peripheral surface of the shaft 22 and elastically deforms, each slit 32 shrinks in the circumferential direction of the cylindrical portion 30A (the width dimension of each slit 32 along the circumferential direction of the cylindrical portion 30A becomes smaller), thereby absorbing changes in the circumferential length of the cylindrical portion 30A.

[0027] In the vehicle seat 10 configured as described above, resin bushings 30 are interposed between the bracket 20 of the seat back 14 and the frame 24 of the armrest 18, and between the shaft 22 and the frame 24. This reduces sliding resistance when the armrest 18 is rotated relative to the seat back 14, prevents wear on the shaft 22 and the frame 24, and prevents abnormal noise caused by metal parts coming into contact with each other.

[0028] In the resin bushing 30 described above, the cylindrical portion 30A, which is formed in a non-circular (here, substantially triangular) cylindrical shape when viewed in the axial direction, is sandwiched and elastically deformed between the inner circumferential surface of a circular hole 26 formed in the frame 24 of the armrest 18 and the outer circumferential surface of the shaft 22 inserted into the circular hole 26. Three points on the outer circumferential surface of this cylindrical portion 30A are pressed against the inner circumferential surface of the circular hole 26, and three points on the inner circumferential surface are pressed against the outer circumferential surface of the shaft 22. This makes it possible to effectively suppress the generation of rattles and abnormal noise.

[0029] The above-mentioned effects will be further explained using a comparative example shown in Fig. 5. In a resin bushing 30' according to this comparative example, the tubular portion 30A' is formed in a cylindrical shape. In this comparative example, dimensional tolerances are set for the outer diameter D1 of the tubular portion 30A', the inner diameter D2 of the circular hole 26, the outer diameter d1 of the shaft 22, and the inner diameter d2 of the tubular portion 30A', taking into consideration the ease of insertion when fitting the tubular portion 30A' into the circular hole 26 of the frame 24, the ease of insertion when fitting a shaft inside the tubular portion 30A', and the rotational torque when rotating the armrest 18 relative to the seat back 14.

[0030] The above dimensional tolerances are set to a minimum clearance to ensure smooth rotation of the armrest 18. If this clearance is the median or maximum of each tolerance, rattles and abnormal noises may occur due to vibrations while the vehicle is running. In other words, the minimum clearance D2 min (Minimum tolerance of D2)-D1 max (Maximum tolerance of D1) is set to 0, the maximum clearance is D2 max (Maximum tolerance of D2)-D1 min (Minimum tolerance value of D1) is the maximum tolerance range. Similarly, d2 min (Minimum tolerance of d2)-d1 max If you set (maximum tolerance of d1) to 0, the maximum clearance, d2 max (Maximum tolerance of d2)-d1 min (Minimum tolerance value of d1) is the maximum tolerance range. In many cases, this clearance is the cause of rattles and abnormal noises.

[0031] In this regard, in this embodiment, the outer surface of the tubular portion 30A of the resin bushing 30 strongly interferes with the inner surface of the circular hole 26 of the frame 24, and the inner surface of the tubular portion 30A strongly interferes with the outer surface of the shaft 22, thereby suppressing the occurrence of rattles and abnormal noises.

[0032] Moreover, in this resin bushing 30, the cylindrical portion 30A is formed with a plurality of (here, three) slits 32 extending in the axial direction. Therefore, when the cylindrical portion 30A is sandwiched between the inner peripheral surface of the circular hole 26 and the outer peripheral surface of the shaft 22 and elastically deforms, the change in the circumferential length of the cylindrical portion 30A can be absorbed by the slits 32. In other words, because the contact points of the cylindrical portion 30A with the circular hole 26 and the shaft 22 are shifted in the circumferential direction of the cylindrical portion 30A, the circumferential length of the cylindrical portion 30A increases when the cylindrical portion 30A elastically deforms, but the increase in the circumferential length can be absorbed by the slits 32.

[0033] In the above embodiment, the cylindrical portion 30A is formed in a substantially triangular cylindrical shape when viewed from the axial direction, but this is not limiting. The cylindrical portion may also be formed in a substantially polygonal cylindrical shape.

[0034] Furthermore, in the above embodiment, three slits 32 are formed in the cylindrical portion 30A, but the number of slits is not limited to this and can be changed as appropriate.

[0035] In the above embodiment, the present invention has been described as being applied to the resin bushing 30 provided between the frame 24 and the shaft 22 of the armrest 18, but the present invention is not limited to this. For example, the present invention may be applied to a resin bushing provided in a free hinge that connects a retractable seatback of a vehicle rear seat to the vehicle body.

[0036] In addition, the present invention can be implemented with various modifications within the scope of the gist thereof. Furthermore, it goes without saying that the scope of the rights of the present invention is not limited to the above-described embodiment. [Explanation of symbols]

[0037] 10 Vehicle seats 22 shaft 24 Armrest frame (component) 26 circular hole 30 Resin bushing 30A cylindrical part 32 Slit

Claims

1. A resin bushing has a cylindrical portion formed in a non-circular cylindrical shape when viewed from the axial direction, and the cylindrical portion is sandwiched between the inner surface of a circular hole formed in a component of a vehicle seat and the outer surface of a shaft inserted into the circular hole, thereby elastically deforming.

2. 2. The resin bushing according to claim 1, wherein the cylindrical portion is formed in a generally triangular cylindrical shape when viewed in the axial direction.

3. 3. The resin bushing according to claim 1, wherein the cylindrical portion has one or more slits extending in the axial direction.

4. a component member having a circular hole formed therein; a shaft inserted into the circular hole; The resin bushing according to claim 1 or 2, wherein the cylindrical portion is sandwiched between an inner peripheral surface of the circular hole and an outer peripheral surface of the shaft; A vehicle seat comprising:

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