Damper and seat suspension mechanism

Abstract

To make proper damping force function according to a relative displacement.SOLUTION: Three-dimensional fabrics 31,32 are provided in one of a first member 10 and a second member 20 provided relatively movably so that a clearance C between itself and the other in a direction orthogonal to a movement direction partially varies along the movement direction. Therefore, by a relative position of the first member 10 and the second member 20, a compression amount of the three-dimensional fabrics 31,32 by compression members 51,52 is varied, and accordingly, sliding resistance force applied to both of them varies. Thus, by adjustment of the clearance C between the three-dimensional fabrics 31,32 and the first member 10 or the second member 20, damping force generated when the first member 10 and the second member 20 relatively move can be set to various characteristics.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a damper and a seat suspension mechanism using such a damper.

Background Art

[0002] In a seat suspension mechanism for supporting an automobile seat, a suspension disposed between a wheel and a vehicle body, etc., various dampers (shock absorbers) for absorbing vibrations during running are disposed. Further, not limited to vehicles such as automobiles, various industrial equipment, joints of robots, opening / closing parts and hinge parts of doors, notebook personal computers, etc., various dampers are used for vibration absorption, shock buffering, etc. As these dampers, as in Patent Document 1, a damper (viscous damper or oil damper) that fills a cylinder with a viscous fluid and utilizes viscous resistance by sliding a piston inside it, and a friction damper that utilizes the frictional force between a piston and a cylinder, as in Patent Document 2, are known.

[0003] When utilizing the viscous resistance of a viscous fluid as in Patent Document 1, sufficient damping force may not be obtained in the region of small stroke and low speed. Further, the friction damper of Patent Document 2 may become a rigid body and not function as a damper due to a large frictional damping force in the case of small stroke input.

[0004] On the other hand, Patent Document 3 discloses a damper in which a movable inner cylinder that is axially slidable inside an outer cylinder and has an orifice formed in its peripheral wall is disposed, and further, a piston around which a linear member that generates frictional force is wound is disposed inside the movable inner cylinder, and the outer cylinder including the inside of the movable inner cylinder is filled with a viscous liquid (low-consistency grease) (see FIG. 21). According to this damper, when the piston moves together with the movable inner cylinder, almost no damping force acts, and when the piston relatively moves inside the movable inner cylinder, a high damping force is exhibited due to the viscous friction with the movable inner cylinder and the viscous resistance when the viscous liquid passes through the orifice.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2015-78725 [Patent Document 2] Japanese Patent Publication No. 2015-117754 [Patent Document 3] Japanese Patent Publication No. 2020-197239 [Overview of the project] [Problems that the invention aims to solve]

[0006] Unlike the dampers disclosed in Patent Documents 1 and 2, the damper disclosed in Patent Document 3 can increase the damping force according to the stroke amount. Therefore, when applied to a seat suspension mechanism, it is possible to set the damper so that in areas where vibration isolation by the action of a spring mechanism is suitable, such as minute vibrations, there is an area where almost no damping force acts (free play area), and for impact vibrations, there is an area where a high damping force acts.

[0007] In the damper of Patent Document 3, the free-play region where damping force is almost ineffective is the range in which the piston moves together with the movable inner cylinder, that is, the range in which the movable inner cylinder moves independently of the outer cylinder. On the other hand, the range in which it is desirable to set the seat suspension mechanism so that high damping force does not function is near the equilibrium point. Therefore, it is necessary to set the damper's free-play region to correspond to the equilibrium point within the vertical stroke range of the seat suspension mechanism. However, the movable inner cylinder moves independently of the outer cylinder, and the positional relationship between the movable inner cylinder and the piston is not constant. Therefore, even if the relative position of the outer cylinder and the piston is initially set to a predetermined position, the position of the movable inner cylinder cannot be restricted, and the starting point for entering the free-play region cannot always be set to a specific position. Therefore, depending on the vibrations input to the suspension mechanism, the free-play region may not correspond to the equilibrium point of the suspension mechanism. In addition, since the damper of Patent Document 3 uses grease, the grease softens due to frictional heat associated with continuous operation, and the viscous damping force decreases.

[0008] The present invention has been made in view of the above, and aims to provide a damper and a seat suspension mechanism using the same that can change the damping force depending on the relative position of the first member and the second member, can keep constant the position at which the damping force enters a region where it hardly acts (free play region), and can further suppress the decrease in damping force due to continuous operation. [Means for solving the problem]

[0009] To solve the above problems, the damper of the present invention is A first member and a second member are provided to be relatively movable, A three-dimensional fabric is provided on one of the first member and the second member such that the clearance between the first member and the second member in a direction perpendicular to the direction of movement of the first member and the second member changes partially along the direction of movement, A compression member provided on the other side of the first member and the second member, which compresses the three-dimensional fabric when the first member and the second member move relative to each other, It has, The amount of compression of the three-dimensional fabric by the compression member changes as the clearance changes due to the relative positions of the first and second members, and a sliding resistance force acts in accordance with that amount of compression. It is characterized by the following:

[0010] Preferably, the three-dimensional fabric is provided such that, when the relative positions of the first and second members are within a predetermined range, the amount of compression is smaller than in the range beyond the predetermined range, and the sliding resistance force is less than or equal to a predetermined value. The predetermined range can be configured to be a predetermined range centered on the neutral position in the relative movement range of the first member and the second member.

[0011] Preferably, a ball member supported by a retainer is provided between the first member and the second member, and in a range where the amount of compression of the three-dimensional fabric exceeds a predetermined level, the rolling of the ball member is suppressed and the coefficient of friction increases. It is preferable that the second member has the characteristic of temporarily becoming rigid due to the wedge effect of the ball member when the position of the second member relative to the first member is at the end position of the relative movement range. Preferably, the three-dimensional fabric is laminated on the side of the support plate provided on one of the first and second members that faces the other member. It is preferable that the support plate and the compression member are made of spring steel. It is preferable that a restricting member is provided between the support plate and one of the first member and the second member to restrict the amount of deflection of the support plate. It is preferable that the three-dimensional fabric is a three-dimensional knitted fabric. It is more preferable that the monofilaments or multifilaments constituting the three-dimensional knitted fabric are made of polyester resin.

[0012] Furthermore, the present invention relates to a seat suspension mechanism which is positioned between the vehicle body structure and the seat and elastically biases an upper frame attached to the seat side with respect to a lower frame attached to the vehicle body structure side by a spring mechanism, The present invention provides a seat suspension mechanism in which the damper is used as a damper that exerts a damping force to absorb energy when the upper frame moves up and down relative to the lower frame. [Effects of the Invention]

[0013] According to the present invention, a three-dimensional fabric is provided on one of the first and second members, which are provided to be relatively movable, such that the clearance between them in a direction perpendicular to their direction of movement partially changes along the direction of movement. Therefore, the amount of compression of the three-dimensional fabric by the compression member changes depending on the relative position of the first and second members, and this changes the sliding resistance force acting between them. Thus, by adjusting the clearance between the three-dimensional fabric and either the first or second member, the damping force generated when the first and second members move relative to each other can be set to various characteristics. Since the damping force is determined by the relationship between the clearance between the three-dimensional fabric and either the first or second member and the relative position of the first and second members, the position at which the damping force enters a region where it hardly acts (free play region) can be easily set to a predetermined position. Furthermore, by using a three-dimensional fabric, especially a three-dimensional knitted fabric, the decrease in damping force due to continuous operation can be suppressed.

[0014] Therefore, when applied to seat suspension mechanisms, etc., it becomes possible to accurately align the equilibrium point with the damper's free-play region, efficiently dampen vibrations near the equilibrium point through the action of the spring mechanism, and easily create a structure that exhibits high damping force near the upper and lower moving ends. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a longitudinal cross-sectional view showing a damper according to one embodiment of the present invention. [Figure 2]Figure 2 is a sectional view taken along line A-A of Figure 1. [Figure 3] Figure 3 is a longitudinal sectional view showing a damper according to another embodiment. [Figure 4] Figures 4(a) to (c) show an example of a three-dimensional solid fabric. Figure 4(a) is a sectional view, Figure 4(b) is a plan view of one ground fabric, and Figure 4(c) is a plan view of the other ground fabric. [Figure 5] Figure 5(a) is a schematic view showing how the connecting threads are woven in an X shape when viewed from the widthwise section of the three-dimensional solid fabric, and Figure 5(b) is a schematic view showing how the connecting threads are woven in an I shape when viewed from the roll direction (longitudinal direction) side of the same three-dimensional solid fabric. [Figure 6] Figure 6 is a view showing an example of a seat suspension mechanism to which a damper is attached. [Figure 7] Figures 7(a) to (c) are views for explaining the operation of the damper according to the embodiment shown in Figures 1 and 2. [Figure 8] It is a view for explaining the experimental method of Experimental Example 1. [Figure 9] It is a view showing the load-deflection characteristics of the three-dimensional solid fabric used in Experimental Example 1. [Figure 10] Figure 10 is a Lissajous figure showing the experimental results in Experimental Example 1 when the compression amount of the three-dimensional solid fabric is 1.75 mm. [Figure 11] Figure 11 is a Lissajous figure showing the experimental results in Experimental Example 1 when the compression amount of the three-dimensional solid fabric is 3.5 mm. [Figure 12] Figure 12 is a Lissajous figure showing the experimental results in Experimental Example 1 when the compression amount of the three-dimensional solid fabric is 5.25 mm. [Figure 13] Figure 13 is a figure plotting the peak value of the sliding resistance force against the compression amount of the three-dimensional solid fabric in Experimental Example 1. [Figure 14] Figure 14 is a Lissajous figure showing the experimental results of Experimental Example 2 for the damper shown in Figures 1 and 2. [Figure 15]Figure 15 is a Lissajous figure showing the experimental results of Experimental Example 2, which was measured by removing the block member, which acts as a regulating member, from the damper shown in Figures 1 and 2. [Figure 16] Figure 16 is a Lissajous figure showing the experimental results of Experiment Example 2 for the damper shown in Figure 3. [Figure 17] Figure 17 is a Lissajous figure showing the experimental results of Experimental Example 2, which was measured by removing the block member, which acts as a regulating member, from the damper shown in Figure 3. [Figure 18] Figure 18 shows the experimental results of Experimental Example 3, relating to the damper according to the embodiment and a conventional damper. [Figure 19] Figure 19 shows the state of wear on the sliding surface of the tertiary wool three-dimensional knitted fabric used in Experimental Example 3. [Figure 20] Figure 20 shows the load-deflection characteristics of the three-dimensional knitted fabric used in Experimental Example 3, before and after the experiment. [Figure 21] Figure 21 is a longitudinal cross-sectional view showing the schematic configuration of a conventional damper. [Modes for carrying out the invention]

[0016] The present invention will be described in more detail below based on the embodiments shown in the drawings. Figures 1 and 2 show the damper 1 of this embodiment. The damper 1 of this embodiment is an expandable type having a first member 10 and a second member 20, both of which are relatively movable in the linear direction, and is composed of three-dimensional fabrics 31, 32, support plates 41, 42 and compression members 51, 52, etc.

[0017] The first member 10 is formed in a substantially cylindrical shape having a predetermined length. Its shape is substantially rectangular in cross-section, with two opposing surfaces 11 and 12 being flat surfaces. The other two opposing surfaces 13 and 14 have thickened portions 13a and 14a near the flat surfaces 11 and 12, and guide portions 13b and 14b extending in the longitudinal direction are formed between the thickened portions 13a and 14a.

[0018] The second member 20 is formed in a substantially rectangular cross-section, with both ends 21 and 22 in the width direction fitting into guide portions 13b and 14b formed in the first member 10, and being movable along the guide portions 13b and 14b. An insertion hole 10b is provided in one end wall 10a of the first member 10, and the second member 20 is inserted into the hollow portion of the first member 10 through this insertion hole 10b, with both ends 21 and 22 in the width direction engaging with the guide portions 13b and 14b. In this embodiment, the second member 20 is a hollow body, but this is for weight considerations, and it is not limited to this and may be solid depending on the mechanism to which it is applied. Furthermore, the second member 20 is not limited to a substantially rectangular cross-section as long as it can move linearly relative to the first member 10 and can support the compression members 51 and 52 described later and perform the function of compressing the three-dimensional fabric 31 and 32.

[0019] Furthermore, retainers 13c and 14c, which have a substantially C-shaped cross-section, are interposed between the guide portions 13b and 14b of the first member 10 and both ends 21 and 22 in the width direction of the second member 20, and three ball members 13d and 14d are provided at the center and both ends of the cross-section of the retainers 13c and 14c, respectively. Thus, both ends 21 and 22 in the width direction of the second member 20 are supported in the cross-sectional direction by being held by the retainers 13c and 14c and the three ball members 13d and 14d. The retainers 13c and 14c are interposed in the second member 20 near the tip (near the other end 10c of the first member 10), similar to the compression members 51 and 52 described later, and move by a predetermined amount along the direction of movement when the second member 20 moves relative to the first member 10.

[0020] The materials constituting the first member 10 and the second member 20 are not limited, but they are made of aluminum of a predetermined thickness considering durability and thermal conductivity. The ball members 13d and 14d are made of synthetic resin in this embodiment, but they may also be made of metal.

[0021] The three-dimensional fabrics 31 and 32 are supported on the first member 10 such that the clearance C between it and the second member 20 (the clearance in a direction perpendicular to the direction of movement of the second member 20 relative to the first member 10) changes partially along the direction of movement.

[0022] Specifically, support plates 41 and 42 are attached to the inner wall side of the flat surfaces 11 and 12 of the first member 10. The support plates 41 and 42 are preferably made of spring steel and are bent to have, when viewed from the side, one flat end portion 41a and 42a, an inclined portion 41b and 42b extending diagonally from the one end portion 41a and 42a, and the other end portion 41c and 42c extending from the inclined portion 41b and 42b so as to be substantially parallel to the one end portion 41a and 42a.

[0023] One support plate 41 is provided such that one end 41a is screwed to the inner wall of one flat surface 11 near the center of the first member 10 in the longitudinal direction, and the other end 41c is located closer to the one end wall 10a of the first member 10. The other support plate 42 is provided such that one end 42a is screwed to the inner wall of the other flat surface 12 near the one end wall 10a of the first member 10, and the other end 42c is located near the center of the first member 10 in the longitudinal direction.

[0024] In this embodiment, the three-dimensional fabrics 31 and 32 are both made of the same thickness. One three-dimensional fabric 31 is laminated and fixed on one support plate 41, and the other three-dimensional fabric 32 is laminated and fixed on the other support plate 42. The fixing means are not limited, but in this embodiment, hook-and-loop fasteners 41d and 42d are attached to each support plate 41 and 42, and the three-dimensional fabrics 31 and 32 are fixed via these hook-and-loop fasteners 41d and 42d.

[0025] As a result, in one three-dimensional fabric 31, the clearance C with the second member 20 is maximized at the first portion 31a located on one end 41a of the support plate 41, the clearance C with the second member 20 gradually decreases at the second portion 31b located on the inclined portion 41b as it moves toward the end wall 10a of the first member 10, and the clearance C with the second member 20 is minimized at the third portion 31c located on the other end 41c. The other three-dimensional fabric 32 has the opposite positional relationship. In other words, at the first portion 32a of the first member 10 located on one end 42a of the other support plate 42, the clearance C with the second member 20 is maximized. At the second portion 32b located on the inclined portion 42b, the clearance C with the second member 20 gradually decreases as it moves toward the other end 10c of the first member 10, and at the third portion 32c located on the other end 42c, the clearance C with the second member 20 is minimized.

[0026] Thus, the clearance C between the three-dimensional fabrics 31 and 32 and the second member 20 can be partially varied depending on the configuration in which the three-dimensional fabrics 31 and 32 are placed within the first member 10 of the support plates 41 and 42 that support them.

[0027] Furthermore, a block member 15 is provided between the other end 41c of one support plate 41 located near the end wall 10a of the first member 10 and the inner surface of the first member 10, as a restricting member to restrict the amount of deflection of one support plate 41. Similarly, a block member 16 is provided between the other end 42c of the other support plate 42 located near the center of the first member 10 and the inner surface of the first member 10, as a restricting member to restrict the amount of deflection of the other support plate 42.

[0028] The three-dimensional fabrics 31 and 32 are selected from three-dimensionally constructed woven fabrics, knitted fabrics, or nonwoven fabrics. Among these, it is more preferable to use a three-dimensional knitted fabric 100 that has appropriate rigidity and elasticity in both the compression direction and the surface direction (see Figures 4 and 5). The three-dimensional knitted fabric 100 is formed by joining a pair of ground knitted fabrics 110 and 120, which are spaced apart from each other, with a connecting yarn 130. The thickness of the ground yarn that forms the ground knitted fabrics 110 and 120 is selected to provide the necessary stiffness for the three-dimensional knitted fabric while not making the knitting process difficult. In addition, it is possible to use monofilament as the ground yarn, but it is also possible to use multifilament from the viewpoint of softness of texture and surface feel. It is also possible to use multifilament yarn for the connecting yarn 130, but it is preferable to use monofilament yarn because it is easier to obtain the desired elasticity.

[0029] Various materials can be used as the ground yarn or connecting yarn 130 that forms the ground fabrics 110 and 120. Examples include synthetic fibers such as polypropylene, polyester, polyamide, polyacrylonitrile, and rayon, as well as regenerated fibers and natural fibers such as wool, silk, and cotton. These materials may be used individually or in combination as desired. Preferably, the materials are thermoplastic polyester fibers such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyamide fibers such as nylon 6 and nylon 66, polyolefin fibers such as polyethylene and polypropylene, or combinations of two or more of these fibers. Polyester fibers are more preferable because they have excellent recyclability and heat resistance.

[0030] The arrangement of the connecting yarns 130 (pile structure) is not limited, but after knitting the three-dimensional knitted fabric 100, when viewed from the width direction, it can be knitted in an X shape as shown in Figure 5(a), and when viewed from the roll direction (longitudinal direction), it can be knitted in an I shape as shown in Figure 5(b).

[0031] Furthermore, the three-dimensional knitted fabric 100, in its raw state, does not have a fixed shape and is subject to shrinkage and stretching. Therefore, in the final stage of manufacturing, it undergoes a process called heat setting, where its shape and thickness are fixed by heat at around 140°C.

[0032] The compression members 51 and 52 are provided on the second member 20 and press against the three-dimensional fabric 31 and 32 when moving relative to the first member 10. As long as the compression members 51 and 52 perform this function, their shape and material are not limited, and they may be formed integrally with the first member 10, or they may be formed separately and then integrated using screws or the like.

[0033] In this embodiment, the compression members 51 and 52 are formed from spring steel and are provided on the second member 20 in a form that bulges outwards in the direction of the three-dimensional fabrics 31 and 32, which are located on the first member 10 side. In this embodiment, as shown in Figures 1 and 2, they are fixed to two opposing surfaces 23 and 24 of the second member 20 and have a trapezoidal shape that bulges outwards. Since the trapezoidal upper end surfaces 51a and 52a are the surfaces that come into contact with the three-dimensional fabrics 31 and 32, low-concentration grease is applied to these upper end surfaces 51a and 52a.

[0034] As described above, the clearance C between the three-dimensional fabrics 31 and 32 is maximized at one end 31a and 32a relative to the second member 20. For this reason, the compression members 51 and 52 are set to be in positions corresponding to the one end 31a and 32a in the region where the damping force is to be kept below a predetermined level (free play region). Specifically, as shown in Figure 1, one end 31a of one three-dimensional fabric 31 is closer to the other end 10c of the first member 10 than one end 32a of the other three-dimensional fabric 32. Therefore, the compression members 51 and 52 are also set to correspond to this difference in the positions of the one end 31a and 32a, such that one compression member 51 is closer to the other end 10c of the first member 10 than the other compression member 52. Thus, in this embodiment, the clearance C of the three-dimensional fabrics 31 and 32 with respect to the second member 20, that is, the shape of the support plates 41 and 42 and the formation positions of the compression members 51 and 52, allows the region where the damping force is to be set to a predetermined value, such as the free-play region, within the range of movement of the second member 20 relative to the first member 10, to be set to a desired position, for example, near the center of the first member 10 (the neutral position when applied to a suspension mechanism).

[0035] Furthermore, for example, as shown in damper 1A in Figure 3, if one end 41a of one support plate 41 is positioned closer to the one end wall 10a of the first member 10, similar to the other support plate 42, a free-play region where the damping force is below a predetermined level is formed closer to the one end wall 10a. In this embodiment, each support plate 41, 42 is shaped to have one end 41a, 42a and the other end 41c, 42c that are substantially parallel, and an inclined portion 41b, 42b that connects the two. However, by shaping each support plate 41, 42 in a different way, or by shaping the compression members 51, 52 in an appropriate shape, various damping force characteristics can be exhibited within the relative movement range of the first member 10 and the second member 20.

[0036] Figure 6 shows an example of a seat suspension mechanism 1000. This seat suspension mechanism 1000 has a lower frame 1100 as a fixed member attached to the vehicle body structure (not shown) and an upper frame 1200 attached to the seat (not shown), with the upper frame 1200 being supported by the lower frame 1100 via a parallel link 1300. It is also elastically supported via a spring mechanism. The damper 1 is installed by connecting the first member 10 to the lower frame 1100 and the second member 20 to the upper frame 1200.

[0037] Figures 7(a) to 7(c) show the relative positional relationship between the first member 10 and the second member 20 within the stroke range of the upper frame 1200, with (a) showing the relative positional relationship at the upper end position, (b) at the neutral position, and (c) at the lower end position.

[0038] As shown in Figure 7(a), at the upper end of the upper frame 1200, one compression member 51 of the second member 20 contacts the third portion 31c of one of the three-dimensional fabrics 31, but the other compression member 52 does not contact the other three-dimensional fabric 32. One compression member 51 presses the third portion 31c of one of the three-dimensional fabrics 31 outward (towards the inner surface of the first member 10). Since the third portion 31c is located on the other end 41c, which is the free end of one of the support plates 41, the other end 41c is also pressed outward. Since a block member 15 is disposed between the other end 41c and the first member 10, when it comes into contact with the block member 15, it is unable to displace outward, and one of the three-dimensional fabrics 31 is compressed in the thickness direction. As a result, a restoring force acts on one of the three-dimensional fabrics 31, and a sliding resistance force corresponding to the amount of compression of the three-dimensional fabric 31 acts on the second member 20 via the one compression member 51. This results in a high damping force at the upper end position.

[0039] As the second member 20 moves from the upper end position to the neutral position shown in Figure 7(b) relative to the first member 10, one compression member 51 passes through the second portion 31b of the one three-dimensional fabric 31 and reaches a position corresponding to the first portion 31a. Since the second portion 31b is a region where the clearance C gradually widens, the sliding resistance force gradually decreases, and the amount of compression of the first portion 31a is minimized at the position corresponding to the first portion 31a. At this time, the other compression member 52 is in a position corresponding to the first portion 32a of the other three-dimensional fabric 32. At this neutral position, the spacing between the one compression member 51 and the other compression member 52 is set so that they both correspond to the first portions 31a and 32a, which are the fixed ends of the first member 10. As a result, the amount of compression of the first portion 32a of the other three-dimensional fabric 32 by the other compression member 52 is also minimized within the range of movement of the second member 20, and the sliding resistance force (damping force) at the neutral position is minimized. Therefore, it is possible to easily and reliably set the neutral position to a free-play area where the damping force is less than or equal to a predetermined level.

[0040] As the second member 20 moves from a neutral position relative to the first member 10 to the lower end position shown in Figure 7(c), one compression member 51 moves away from the area to which one three-dimensional fabric 31 is attached, and the other compression member 52 comes into contact with the third portion 32c of the other three-dimensional fabric 32. The other compression member 52 presses the third portion 32c of the other three-dimensional fabric 32 outward (towards the inner surface of the first member 10). Since the third portion 32c is located on the other end portion 42c, which is the free end of the other support plate 42, the other end portion 42c is also pressed outward. However, when it comes into contact with the block member 16 disposed between the other end portion 42c and the first member 10, it is unable to be displaced outward, and the other three-dimensional fabric 32 is compressed in the thickness direction. As a result, the restoring force of the other three-dimensional fabric 32 acts on the second member 20 via the other compression member 52, and a sliding resistance force corresponding to the amount of compression of the other three-dimensional fabric 32 acts on the second member 20. As a result, a high damping force acts at the lower end position.

[0041] Thus, according to this embodiment, high damping force can be exerted at the upper and lower ends of the suspension mechanism 1000, and the damping force can be reduced at the neutral position. Therefore, by selecting the thickness and material of the three-dimensional fabrics 31 and 32, the restoring force of the three-dimensional fabrics 31 and 32 at the neutral position can be set to a predetermined level or lower, thereby easily setting the damping force at the neutral position to a predetermined level or lower free play area.

[0042] (Experimental Example 1) (Relationship between compression amount and sliding resistance of three-dimensional knitted fabric) As shown in Figure 8, a steel plate was sandwiched between two three-dimensional knitted fabrics, and the load was measured when the steel plate was slid between them. Low-concentration grease was applied between the steel plate and each three-dimensional knitted fabric. The three-dimensional knitted fabrics used were manufactured by Asahi Kasei Advance Co., Ltd., product number: AKE70044, with a thickness of 7 mm under no load. The compression amounts were 1.75 mm (compression ratio 25%), 3.5 mm (compression ratio 50%), and 5.25 mm (compression ratio 75%), and the input vibration amplitudes were 5 mm, 10 mm, and 20 mm, with frequencies of 1 Hz and 2 Hz sine waves. The load-deflection characteristics of the three-dimensional knitted fabrics used are shown in Figure 9.

[0043] Figures 10 to 12 show Lissajous figures. The sliding resistance force of the three-dimensional knitted fabric was 49-66 N when the compression amount was 1.75 mm, 85-109 N when the compression amount was 3.5 mm, and 460-559 N when the compression amount was 5.25 mm.

[0044] Figure 13 plots the peak value of the sliding resistance force (vertical axis) against the compression amount (horizontal axis) of the three-dimensional knitted fabric when excited with a sinusoidal wave of 20 mm amplitude and 2 Hz frequency. The sliding resistance force increases significantly between a compression amount of 3.5 mm and 5.25 mm, which is consistent with the trend of the load-deflection characteristics (see Figure 9). From these experimental results, it can be seen that the sliding resistance force is generated by the frictional force between the iron plate (corresponding to compression members 51 and 52) and the three-dimensional knitted fabric. The sliding resistance force is constant and does not depend on the excitation frequency, but is proportional to the amplitude. However, a slight hysteresis occurs when the amplitude returns after reaching its maximum.

[0045] (Experimental Example 2) (Sliding resistance force of the prototype damper of the embodiment) The sliding resistance force of each prototype damper 1 and 1A described in the embodiment was evaluated. The input vibration was a sine wave with amplitudes of 5 mm, 10 mm, 20 mm, and 25 mm, and frequencies of 0.5 Hz, 1.0 Hz, and 2.0 Hz. Damper 1 has the structure shown in Figures 1 and 2, and is a type in which a free play area with damping force below a predetermined level is provided near the center of the first member 10. Damper 1A is a type in which a free play area with damping force below a predetermined level is provided near one end wall 10a of the first member 10, as shown in Figure 3. In addition, a comparison was made between cases in which block members 15 and 16 as restricting members were present and cases in which they were not provided.

[0046] The compression amount of the three-dimensional knitted fabrics used as three-dimensional woven fabrics 31 and 32 was 1.4 mm in the free play area and 5.6 mm in the attenuation section (the area including the upper end position in Figure 7(a) and the lower end position in Figure 7(c)).

[0047] The results are shown in Figures 14 to 17. As shown in Figure 14, when block members 15 and 16 are arranged, the sliding resistance force of damper 1 is 9 to 16 N at the neutral position (0 mm) and 385 to 417 N at the lower end position (+25 mm). N At the upper end position of -25mm, the N was 308-345N. In the configuration without block members, as shown in Figure 15, the N was 4-15N at 0mm, 26-35N at +25mm, and 32-43N at -25mm. Therefore, a low sliding resistance force could be achieved at the neutral position of the suspension mechanism, and a high sliding resistance force could be obtained at the upper and lower end positions. However, if block members 15 and 16 are not placed, the sliding resistance force at the upper and lower end positions will be small, so in order to obtain a high sliding resistance force at the upper and lower end positions when the support plates 41 and 42 are made of spring steel, it is preferable to restrict the sliding resistance force with block members 15 and 16.

[0048] Figures 16 and 17 are Lissajous figures showing the experimental results for damper 1A. At the lower end position, with a displacement of +25 mm, the sliding resistance force increased, with peak values ​​of 871-947 N with the block and 76-104 N without the block.

[0049] In this way, the sliding resistance can be adjusted in various ways by the presence or absence of the block members 15 and 16. Block members 15 and 16 can be provided to increase the sliding resistance at the upper and lower end positions, while the configuration can be made without block members 15 and 16 if a lower sliding resistance is acceptable. The sliding resistance can also be adjusted by the spring force of the spring steel of the support plates 41 and 42. The sliding resistance can also be changed by forming the support plates 41 and 42 from a rigid body instead of spring steel, but it is preferable to form them from spring steel considering the sliding properties of the second member 20.

[0050] In the Lissajous figure shown in Figure 14, the damping force in the direction from the neutral position to the lower end is much greater than the damping force in the opposite direction, and similarly, the damping force in the direction from the neutral position to the upper end is much greater than the damping force in the opposite direction. This is because, in the direction from the neutral position to the end position (i.e., the lower or upper end), the movement of the support plates 41 and 42 is restricted by the block members 15 and 16, compressing the three-dimensional fabric 31 and 32. At the same time, the ball members 13d and 14d, supported by the retainers 13c and 14c surrounding both ends 21 and 22 in the width direction of the second member 20, are pressed, increasing the coefficient of friction, and the ball members 13d and 14d exert a wedge effect. Due to this wedge effect, the damper 1 becomes substantially rigid. Due to this characteristic of becoming virtually rigid, there is a temporary period during which no acceleration acts, and the damping force at the end position increases sharply in the direction from the neutral position to the end position (see Figure 14). In other words, there is a temporary period during which the motion of damper 1 stops and the increase in acceleration also stops. On the other hand, when the second member 20 moves in the opposite direction, that is, from the lower end position or upper end position towards the neutral position, the wedge effect of the ball members 13d and 14d is released, and the friction coefficient decreases due to the sliding and rolling of the retainers 13c and 14c and the ball members 13d and 14d. According to this embodiment, the wedge effect and variable friction coefficient allow the sliding resistance force to be varied depending on the direction of movement of the second member 20, enabling efficient stopping and restarting of motion at the top and bottom dead centers. As shown in Figure 14, the damping force when moving from the lower or upper end position towards the neutral position is extremely small, almost the same as near the neutral position. This means that the range over which vibrations can be absorbed by phase control is wide, facilitating the absorption of impact vibrations and vibration absorption by phase control, and making it possible to achieve vibration absorption and impact absorption functions equivalent to those of a suspension mechanism with a larger stroke with a smaller stroke. Therefore, by applying the damper of this embodiment to a suspension mechanism, it is possible to contribute to the thinning and weight reduction of the suspension mechanism.

[0051] (Experimental Example 3) The damper 1 according to the embodiment and the conventional damper shown in Patent Document 3 (see Figure 21) were operated continuously for 1000 cycles with a sine wave of 20 mm amplitude and 2 Hz frequency, and the changes in the peak value of the sliding resistance force were compared. The results are shown in Figure 18 (in Figure 18, "New" indicates data for the damper 1 according to the embodiment, and "Conventional" indicates data for the conventional damper).

[0052] In 1000 continuous cycles, the sliding resistance of the conventional damper decreased from 478N to 127N, a decrease of 73%, while the sliding resistance of damper 1 only decreased from 461N to 304N, a decrease of 34%. However, damper 1 showed a faster decrease in sliding resistance up to 100 cycles. This is because the decrease in sliding resistance immediately after the start of operation is due to the plastic deformation of the multifilaments constituting the ground fabrics 110 and 120 of the three-dimensional knitted fabric 100. Figure 19 shows the state of the multifilaments of the ground fabrics 110 and 120, with a plastic deformation of 0.5 mm in the thickness direction. Figure 20 shows the load-deflection characteristics of the three-dimensional knitted fabric 100 used in damper 1, measured before and after this experiment. As shown in Figure 20, the effect of the 0.5 mm plastic deformation is reflected in the change in hysteresis. This change is due to an increase in the engagement force between the ground fabrics 110 and 120 and the connecting yarn 130, and also contributes to the stabilization of the restoring force shown in Figure 18.

[0053] In other words, the three-dimensional knitted fabric 100 used in the experiment is constructed using monofilaments and multifilaments, but due to the generation of frictional heat during continuous operation, the temperature of the monofilaments constituting the connecting yarn rises to near the heat-set temperature mentioned above. As a result, a restoring force acts from the monofilaments to the multifilaments, and the thickness of the three-dimensional knitted fabric 100 is restored. As a result, the sliding resistance force during continuous operation converges to a nearly constant value, as shown in Figure 18.

[0054] As described above, with the damper of this embodiment, by adjusting the amount of compression by setting the three-dimensional fabrics 31 and 32, any damping characteristics can be applied in the relative movement direction of the first member 10 and the second member 20, and the free play area can also be set to a desired position. Furthermore, compared to conventional viscous damping dampers, the decrease in damping force due to continuous operation can be reduced. Moreover, when three-dimensional knitted fabrics are used as the three-dimensional fabrics 31 and 32, the recovery characteristics due to their heat-setting temperature act autonomously due to frictional heat, contributing to the suppression of the decrease in damping force due to heat. [Explanation of Symbols]

[0055] 1 Damper 10 First Member 13b, 14b Guide section 13c, 14c retainer 13d, 14d Ball member 20 Second Member 31,32 Three-dimensional fabric 41,42 Support plate 51, 52 Compression members 100 Three-Dimensional Knitted Fabrics 1000 Seat Suspension Mechanism

Claims

1. A first member and a second member are provided to be relatively movable, A three-dimensional fabric is provided on one of the first member and the second member such that the clearance between the first member and the second member in a direction perpendicular to the direction of movement of the first member and the second member changes partially along the direction of movement, A compression member provided on the other side of the first member and the second member, which compresses the three-dimensional fabric when the first member and the second member move relative to each other, It has, The amount of compression of the three-dimensional fabric by the compression member changes as the clearance changes due to the relative positions of the first and second members, and a sliding resistance force acts in accordance with that amount of compression. Damper.

2. The damper according to claim 1, wherein the three-dimensional fabric is provided such that when the relative positions of the first member and the second member are within a predetermined range, the amount of compression is smaller than in a range beyond the predetermined range, and the sliding resistance force is less than or equal to a predetermined value.

3. The damper according to claim 2, wherein the predetermined range is a predetermined range centered on the neutral position in the relative movement range of the first member and the second member.

4. The damper according to claim 2, wherein a ball member supported by a retainer is provided between the first member and the second member, and in a range where the amount of compression of the three-dimensional fabric exceeds a predetermined value, the rolling of the ball member is suppressed and the coefficient of friction increases.

5. The damper according to claim 4, which has the characteristic of temporarily becoming rigid due to the wedge effect of the ball member when the position of the second member relative to the first member is at the end position of the relative movement range of the first member and the second member.

6. The damper according to claim 1, wherein the three-dimensional fabric is laminated on the side facing the other of the first and second members in a support plate provided on one of the first and second members.

7. The damper according to claim 6, wherein the support plate and the compression member are formed from spring steel.

8. The damper according to claim 7, wherein a restricting member is disposed between the support plate and one of the first member and the second member to restrict the amount of deflection of the support plate.

9. The damper according to claim 1, wherein the three-dimensional fabric is a three-dimensional knitted fabric.

10. The damper according to claim 9, wherein the monofilament or multifilament constituting the three-dimensional knitted fabric is made of a polyester resin.

11. A seat suspension mechanism is positioned between the vehicle body structure and the seat, and elastically biases an upper frame attached to the seat side with respect to a lower frame attached to the vehicle body structure side by a spring mechanism, A seat suspension mechanism in which a damper according to any one of claims 1 to 10 is used as a damper that exhibits a damping force to absorb energy when the upper frame moves up and down relative to the lower frame.

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