Spring member

Abstract

A spring member according to the present invention comprises a coil spring formed by a spirally wound wire, and a seat part that is provided at one end of the coil spring and bears the coil spring load. The seat part includes a sheet that covers a portion of one end of the coil spring, an insulator that is provided between the sheet and the coil spring, and an adhesive that bonds the insulator and the coil spring. In the seat part, the position of the adhesive on the edge of the one end side of the coil spring is positioned on the edge end of the coil spring or nearer the other end side than the edge end.

Description

Spring material

[0001] The present invention relates to a spring member.

[0002] A spring member is known that includes a coil spring formed by helically winding a wire rod and a seat portion that is provided at the end of the coil spring and receives the load of the coil spring (see, for example, Patent Document 1). In this spring member, an elastic insulator is disposed between the coil spring and the seat portion, and the coil spring and the insulator are fixed together with an adhesive.

[0003] Japanese Patent Application Laid-Open No. 2019-157886

[0004] Incidentally, spring members are required to have durability against high loads.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a spring member that can improve durability against load.

[0006] In order to solve the above-mentioned problems and achieve the object, the spring member of the present invention comprises a coil spring made of wire wound in a spiral shape, and a seat portion provided at one end of the coil spring and receiving the load of the coil spring, wherein the seat portion has a sheet covering a portion of one end of the coil spring, an insulator provided between the sheet and the coil spring, and an adhesive that bonds the insulator and the coil spring, and is characterized in that in the sheet portion, the end of the adhesive on the one end side of the coil spring is positioned at the edge of the coil spring or closer to the other end than the edge.

[0007] In addition, the spring member of the present invention is characterized in that, in the above invention, in the sheet portion, the positions of the ends of the insulator and the adhesive on one end side of the coil spring are located at the edge of the coil spring or on the other end side of the edge.

[0008] Furthermore, the spring member according to the present invention is characterized in that, in the above invention, the ends of the insulator and the adhesive on one end side of the coil spring are each located within a range of 0.1000 turns from the edge end relative to the end face of the coil spring.

[0009] Furthermore, the spring member according to the present invention is characterized in that, in the above invention, the position of the end of the adhesive on one end side of the coil spring is located within a range of 0.0125 turns from the edge end with respect to the end face of the coil spring.

[0010] According to the present invention, it is possible to obtain a spring member that can improve durability against load.

[0011] FIG. 1 is a diagram illustrating a configuration of a spring member according to an embodiment of the present invention. FIG. 2 is an enlarged view of a portion of the spring member shown in FIG. 1. FIG. 3 is a diagram illustrating the configuration of a conventional spring member that serves as a reference. FIG. 4 is a diagram illustrating a method of cutting an insulator in analysis. FIG. 5 is a diagram (part 1) illustrating an example in which a portion of an insulator is cut in a spring member. FIG. 6 is a diagram (part 2) illustrating an example in which a portion of an insulator is cut in a spring member. FIG. 7 is a diagram illustrating analysis results for a spring member according to an embodiment of the present invention. FIG. 8 is an enlarged view of a portion of a spring member according to a first modification of an embodiment of the present invention. FIG. 9 is a diagram illustrating analysis results for a spring member according to the first modification. FIG. 10 is a cross-sectional view illustrating a configuration of a portion of a spring member according to a second modification of an embodiment of the present invention.

[0012] In the following description, a spring member will be described as a form for carrying out the present invention (hereinafter referred to as an "embodiment"). However, the present invention is not limited to this embodiment. Furthermore, in the drawings, the same parts are given the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the relationship between the thickness and width of each part, the ratio of each part, etc., may differ from reality. Furthermore, the drawings may include parts with different dimensions and ratios.

[0013] (Embodiment) Fig. 1 is a diagram showing the configuration of a spring member according to one embodiment of the present invention. Fig. 2 is an enlarged view of a portion of the spring member shown in Fig. 1. The spring member 1 includes a coil spring 2 formed by spirally winding a wire rod, and a seat portion 3 provided at an end of the coil spring 2 and adapted to receive the load of the coil spring.

[0014] The coil spring 2 is formed using, for example, a flat spring steel made of metal, resin, or the like. In this embodiment, the wire is wound around an axis extending in the Z direction shown in Fig. 1. For the sake of explanation, the side of the coil spring 2 on which the seat portion 3 is disposed is referred to as the base end side (one end side), and the side opposite to the side on which the seat portion 3 is disposed is referred to as the tip side (other end side), and a load is applied to the coil spring 2 that presses the tip side (other end side) toward the base end side (one end side).

[0015] The sheet portion 3 has a sheet 31 that covers a part of the base end of the coil spring 2, an insulator 32 that is provided between the sheet 31 and the coil spring 2, and an adhesive 33 that bonds the insulator 32 and the coil spring 2 together.

[0016] The sheet 31 has a concave shape that covers a portion of the base end of the coil spring 2. The sheet 31 has a length less than one turn of the coil spring 2 and covers the base end of the coil spring 2. Specifically, the sheet 31 covers a portion of the side surface of the base end of the coil spring 2 and exposes the end surface (the surface intersecting the longitudinal (extension) direction of the wire rod). Therefore, the coil spring 2 can be displaced in the extension direction (Y direction shown in FIG. 2 ) by elastic deformation of the adhesive 33 or the like. Herein, one turn corresponds to one full turn of the wire rod of the coil spring 2 around the winding axis. Hereinafter, the end of the coil spring 2 on the sheet portion 3 side (the end on the base end side) is defined as the base point (turn 0), and the winding position around the winding axis is referred to as the "turn." In this case, the first turn corresponds to the position from the base point that corresponds to the above-mentioned one full turn.

[0017] The insulator 32 is made of an elastic material, such as rubber, and is disposed between the sheet 31 and the coil spring 2 within the area where the sheet 31 is disposed. The adhesive 33 is made of, for example, a resin.

[0018] In the sheet portion 3 according to the present embodiment, the positions of the ends of the insulator 32 and the adhesive 33 on the base end side of the coil spring 2 include the edge of the coil spring 2 and are located closer to the wire side than the edge. The edge here corresponds to the outer edge that forms the end face of the coil spring 2.

[0019] Next, the arrangement of the insulator 32 and adhesive 33 will be described with reference to Figures 3 to 8. Here, the results of an analysis of stress in the area where the insulator 32 or adhesive 33 is arranged will be described. In the analysis, an analytical model was created for the coil spring 2, sheet 31, insulator 32, and adhesive 33, and the arrangement, material, mesh (element division), interaction (parameters), and boundary conditions were set, and the stress at the interface between the insulator 32 and adhesive 33 was calculated. The stress was output as shear stress, and the difference (percentage) from this shear stress relative to a reference was calculated.

[0020] Fig. 3 is a diagram illustrating the configuration of a conventional spring member used as a reference. The comparison reference spring member shown in Fig. 3 includes a coil spring 2 (see Fig. 1) and a seat portion 300 provided at the end of the coil spring 2 to receive the load of the coil spring.

[0021] The sheet portion 300 has a sheet 310 that covers a part of the base end of the coil spring 2, an insulator 320 that is provided between the sheet 310 and the coil spring 2, and an adhesive 330 that bonds the insulator 320 and the coil spring 2 together.

[0022] The sheet 310 has a concave shape that covers a portion of the coil spring 2. The sheet 310 has a length that is less than one turn of the coil spring 2, and covers the base end portion of the coil spring 2. Specifically, the sheet 310 covers a portion of the side surface and a portion of the end surface of the coil spring 2. The sheet 310 is formed using a resin or metal material.

[0023] The insulator 320 is made of an elastic material, such as rubber, and is disposed between the sheet 310 and the coil spring 2 within the area where the sheet 310 is disposed. The adhesive 330 is made of, for example, a resin.

[0024] Similar to the sheet 310, the insulator 320 and the adhesive 330 cover a portion of the side surface and a portion of the end surface of the coil spring 2. Therefore, the movement of the coil spring 2 in the extension direction (Y direction in FIG. 3 ) is restricted by the sheet portion 300. In the analysis, a model of the above-mentioned comparison reference spring member was created, and the shear stress was calculated.

[0025] In this analysis, the maximum shear stress was calculated for a configuration in which the end of the insulator 32 on the end side of the coil spring 2 was cut. FIG. 4 is a diagram for explaining the cutting method for the insulator in the analysis. For example, as with the insulator 32 shown in FIG. 4 , the shear stress was analyzed for each insulator 32 in which a portion was cut at each dashed line. At this time, the adhesive 33 was also cut in the same way. This cutting was performed by moving the positions of the ends of the insulator 32 and adhesive 33 on the end side of the coil spring 2 from the base end of the coil spring 2 to the tip side of the coil spring 2 (the side along the wire).

[0026] In this analysis, a model having an insulator and adhesive flush with the end face of the coil spring 2, a model of a comparison reference spring member, and a model in which part of the insulator 32 and adhesive 33 have been cut are created, as shown in Figures 1 and 2. Figures 5 and 6 are diagrams showing an example of a spring member in which part of the insulator has been cut. By cutting the insulator 32 and adhesive 33, an analytical model such as that shown in Figures 5 and 6 is created.

[0027] 5 includes a coil spring 120 corresponding to coil spring 2 and a sheet portion 130A corresponding to sheet portion 3. Sheet portion 130A has a sheet 131 corresponding to sheet 31, an insulator 132A corresponding to insulator 32, and an adhesive 133A corresponding to adhesive 33. Model 110 is a model corresponding to a configuration in which insulator 32 and adhesive 33 shown in FIGS. 1 and 2 are cut by 0.0750 (=0.0125×6) turns from the end on the base end surface side of coil spring 2.

[0028] Model 111 shown in Fig. 6 includes a coil spring 120 corresponding to coil spring 2 and a seat portion 130B corresponding to seat portion 3. Sheet portion 130B includes a sheet 131 corresponding to sheet 31, an insulator 132B corresponding to insulator 32, and an adhesive 133B corresponding to adhesive 33. Model 111 corresponds to a configuration in which insulator 32 and adhesive 33 shown in Figs. 1 and 2 are cut by 0.0375 (= 0.0125 x 3) turns from the end on the base end surface side of coil spring 2. It is preferable that the setting conditions, such as mesh, for each member in models 110 and 111 are the same.

[0029] In this analysis, the shear stress was calculated for a flush model (see Figures 1 and 2), a model with 0.0375 turns cut, a model with 0.0750 turns cut, and a model with 0.1125 turns cut.

[0030] Fig. 7 is a diagram for explaining the analysis results, showing the results of analysis of models in which the insulator and adhesive were cut. Fig. 7 shows the ratio of shear stress to the reference, with sample A as a flush model (see Fig. 2), sample B as a model with 0.0375 turns cut (see Fig. 6), sample C as a model with 0.0750 turns cut (see Fig. 5), sample D as a model with 0.1125 turns cut, and the reference being a model of a comparative reference spring member (see Fig. 3).

[0031] As shown in Figure 7, samples A to C each had reduced shear stress compared to the reference. Furthermore, the analysis results showed that the shear stress was lowest for the flush model, and that the shear stress increased as the number of cut turns increased. On the other hand, the model in which 0.1125 turns were cut (sample D) had a higher shear stress than the reference. This is thought to be because a reduction in the adhesive mass (adhesive area) of adhesive 33, etc., reduces the area over which adhesive 33 receives a load from coil spring 2, thereby increasing shear stress.

[0032] From the results shown in FIG. 7, it can be said that the cut amount of the insulator and adhesive that can reduce the shear stress relative to the standard ranges from flush (0 turns) to 0.1000 turns.

[0033] In the above-described embodiment, in the sheet portion 3 attached to the end of the coil spring 2, the positions of the ends of the insulator 32 and the adhesive 33 on the base end side of the coil spring 2 are located at the edge of the coil spring 2 or closer to the other end than the edge, specifically in a range from flush (0th turn) to 0.1000th turn with the base end surface of the coil spring 2. According to this embodiment, by ensuring that the end positions of the insulator 32 and the adhesive 33 satisfy the above-described conditions, damage caused by the edge of the coil spring 2 digging into the adhesive 33 or the insulator 32 when a load is applied to the coil spring 2 toward the sheet portion 3 can be suppressed, and as a result, a spring member with improved durability against loads can be obtained.

[0034] Furthermore, according to the embodiment, the amounts of the insulator 32 and the adhesive 33 used can be reduced compared to the conventional case, thereby making the spring member 1 lighter in weight than the conventional case.

[0035] Furthermore, according to the embodiment, the above-described configuration allows the natural frequency to be made higher than that of the prior art, and as a result, damage to the spring member 1 can be further suppressed.

[0036] (Variation 1) Next, Variation 1 of the embodiment of the present invention will be described with reference to Figs. 8 and 9. Fig. 8 is an enlarged view of a portion of the spring member according to Variation 1. Variation 1 describes a configuration in which only the adhesive is cut out from the above-described spring member. Note that the same components as those in the above-described embodiment are given the same reference numerals.

[0037] The spring member of this variation 1 comprises a coil spring 2 made of spirally wound wire, and a seat portion 3A provided at the end (the end on the base end side) of the coil spring 2 and receiving the load of the coil spring.

[0038] The sheet portion 3A has a sheet 31A that covers a part of the base end of the coil spring 2, an insulator 32A that is provided between the sheet 31A and the coil spring 2, and an adhesive 33A that bonds the insulator 32A and the coil spring 2 together.

[0039] The sheet 31A has a concave shape that covers a portion of the coil spring 2. The sheet 31A has a length that is less than one turn of the coil spring 2, and covers the base end portion of the coil spring 2. Specifically, the sheet 31A covers a portion of the side surface and a portion of the end surface of the coil spring 2.

[0040] The insulator 32A is made of an elastic material, such as rubber. The insulator 32A is disposed between the sheet 31A and the coil spring 2 within the area where the sheet 31A is disposed. The adhesive 33A is made of, for example, a resin. The adhesive 33A covers a portion of the side surface of the coil spring 2, and the end of the adhesive 33A is provided flush with the end surface of the coil spring 2.

[0041] In the sheet portion 3A according to the present first modification, the position of the end of the adhesive 33A on the coil spring 2 side includes the edge of the coil spring 2 and is located closer to the base end than the edge.

[0042] 9 is a diagram for explaining the analysis results, showing the results of analyzing a model in which the adhesive was cut. In FIG. 9, sample E is a flush model (see FIG. 8), and sample F is a model in which 0.0125 turns have been cut, and the ratio of shear stress to the reference is shown. In this case, it is preferable to set the effective range for each cut amount, including the flush, to ±0.05 with respect to the number of turns cut, taking into account manufacturing errors.

[0043] As shown in Figure 9, the shear stress of samples E and F was reduced relative to the reference. In addition, when only the adhesive was cut, the model cut by 0.0125 turns had a lower shear stress than the flush model.

[0044] From the results shown in FIG. 9, it can be said that the cutting amount of only the adhesive that can reduce the shear stress compared to the reference is effective from at least flush (0 turns) to 0.0125 turns.

[0045] In the above-described first modification, in the sheet portion 3A attached to the base end of the coil spring 2, the position of the end of the adhesive 33A on the base end side of the coil spring 2 is set to be flush with the base end surface of the coil spring 2 (0th turn) to 0.0125th turn. According to this first modification, as in the above-described embodiment, damage to the edge of the coil spring 2 caused by the adhesive 33A digging into it can be suppressed, and as a result, a spring member with improved durability against load can be obtained.

[0046] (Variation 2) Next, Variation 2 of the embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view showing the configuration of a portion of a spring member according to Variation 2 of the embodiment of the present invention. Variation 2 describes a configuration in which only the side surface of the coil spring 2 is cut out in the above-described spring member. Note that the same components as those in the above-described embodiment are given the same reference numerals.

[0047] The spring member according to the second modified example includes a coil spring 2 formed by spirally winding a wire rod, and a seat portion 3B provided at the base end of the coil spring 2 to receive the load of the coil spring.

[0048] The sheet portion 3B has a sheet 31 that covers a part of the base end of the coil spring 2, an insulator 32B that is provided between the sheet 31 and the coil spring 2, and an adhesive 33B that bonds the insulator 32B and the coil spring 2 together.

[0049] The insulator 32B is made of an elastic material, such as rubber, and is disposed between the sheet 31 and the coil spring 2 within the area where the sheet 31 is disposed. The adhesive 33B is made of, for example, a resin.

[0050] In the sheet portion 3B according to the second modification, the ends of the insulator 32B and the adhesive 33B on the base end side of the coil spring 2 are located closer to the tip end than the edge of the coil spring 2. Furthermore, in the second modification, the insulator 32B and the adhesive 33B cover a portion of the base end surface of the coil spring 2. The insulator 32B and the adhesive 33B in the second modification cover a portion of the base end surface of the coil spring 2 and a portion of the side surface on the base end side of the coil spring 2, while leaving a portion of the side surface exposed. In this case, for example, on the side surface of the coil spring 2, the ends of the insulator 32B and the adhesive 33B on the coil spring 2 side are located in a range from flush with the end surface of the coil spring 2 (0th turn) to the tip end side up to 0.1000th turn.

[0051] In this way, in variant example 2, an insulator / adhesive is provided at the base end of the coil spring 2, while a portion of the insulator / adhesive provided on the side surface connected to the end face of the coil spring 2 is cut off.

[0052] In the above-described second modification, insulator 32B and adhesive 33B are configured to cover the base end surface and part of the side surface of coil spring 2 while exposing the side surface that is continuous with the end surface in sheet portion 3B attached to the base end of coil spring 2. According to this second modification, as in the above-described embodiment, damage to the edge of coil spring 2 that would otherwise be caused by cutting into adhesive 33B can be suppressed, and as a result, a spring member that can improve durability against load can be obtained.

[0053] As such, the present invention can include various embodiments not described here, and various design changes can be made without departing from the technical concept defined by the claims. In the above-described embodiment and variant example 2, the positions of the ends of the insulator and adhesive do not need to be flush with each other, and the end positions may be offset from each other.

[0054] As described above, the spring member according to the present invention is suitable for improving durability against load.

[0055] REFERENCE SIGNS LIST 1 Spring member 2 Coil spring 3, 3A, 3B Sheet portion 31, 31A Sheet 32, 32A, 32B Insulator 33, 33A, 33B Adhesive

Claims

1. A spring member comprising: a coil spring formed by spirally winding wire; and a sheet portion provided at one end of the coil spring and receiving the load of the coil spring, wherein the sheet portion has: a sheet covering part of one end of the coil spring; an insulator provided between the sheet and the coil spring; and an adhesive for bonding the insulator and the coil spring; and wherein an end of the adhesive on the one end side of the coil spring in the sheet portion is positioned at an edge of the coil spring or on the other end side of the edge.

2. The spring member according to claim 1, characterized in that in the sheet portion, the ends of the insulator and the adhesive on one end side of the coil spring are positioned at the edge of the coil spring or on the other end side of the edge.

3. The spring member according to claim 2, characterized in that the ends of the insulator and the adhesive on one end side of the coil spring are each located within a range of 0.1000 turns from the edge end with respect to the end face of the coil spring.

4. The spring member according to claim 1, characterized in that the adhesive is positioned such that the end of one end of the coil spring is located within 0.0125 turns from the edge of the end face of the coil spring.

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