Coil spring holding structure and coil spring holding method

Abstract

To provide a holding structure of a coil spring which can easily hold the coil spring in a preset position of a holding member, and a holding method of the coil spring.SOLUTION: A coil spring 10 is composed of a diameter change part 14 and a base part 13. The diameter change part 14 is formed into a shape in which a coil diameter gradually becomes small as progressing toward an extension end 15 of the coil spring 10 in a free state that the diameter change part is not elastically deformed, and also formed into a shape protruding to the inside of the coil spring 10 in a radial direction from an internal peripheral face of the base part 13. Three protrusions 22 are formed at a face 211 of the holding member 20 at a side at which the coil spring 10 is held. In a holding state, external peripheral faces of the three protrusions 22 are pressed to the internal peripheral face of the coil spring 10, and in a form that the diameter change part 14 is pressed by the protrusions 22, the diameter change part 14 is elastically deformed to the outside of the coil spring 10 in the radial direction.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a holding structure for a coil spring and a holding method for a coil spring. [Background technology]

[0002] Conventionally, coil springs have been widely used as biasing members for biasing (for example, Patent Document 1). The coil spring described in Patent Document 1 is disposed in a sandwiched state between two members. As a result, the coil spring is held in a compressed state between the two members.

[0003] It has also been proposed to fix the coil spring to a clamping member that clamps the coil spring, etc. In this case, the coil spring is fixed to the clamping member by adhesion or welding. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-174438 A Summary of the Invention [Problem to be solved by the invention]

[0005] When holding a coil spring by sandwiching it between two members, it is necessary to position and arrange the coil spring and the two members, apply pressure to the two members so that the coil spring is compressed, etc. Therefore, in this case, the work of holding the coil spring becomes complicated.

[0006] Furthermore, even when the coil spring is held by bonding or welding to two members, the work of bonding or welding becomes necessary, making the work of holding the coil spring more complicated. [Means for solving the problem]

[0007] Various aspects of the device for solving the above problems will now be described. [Mode 1] A holding structure for a coil spring that is held by a holding member, the coil spring comprising a variable diameter portion that constitutes an end portion in the axial direction and a base portion that constitutes the portion other than the variable diameter portion, the variable diameter portion having a shape in which, in a free state not elastically deformed, the coil diameter gradually changes in one direction toward the extended end of the coil spring and has a shape that protrudes in the radial direction of the coil spring from the circumferential surface of the base portion, the holding member having a plurality of protrusions on a surface that holds the coil spring, and in a held state in which the coil spring is held by the holding member, the circumferential surface of each of the plurality of protrusions is pressed against the circumferential surface of the coil spring and at least one of the plurality of protrusions pushes away the variable diameter portion, so that the variable diameter portion is elastically deformed in the radial direction of the coil spring.

[0008] According to the above configuration, in the held state, the restoring force of the elastically deformed diameter-changing portion can press the circumferential surface of the coil spring against the circumferential surfaces of the multiple protrusions. This pressing force can hold the coil spring in the multiple protrusions, i.e., the holding member. Therefore, the coil spring can be easily fixed and held in a position determined by the multiple protrusions by using the multiple protrusions, without bonding the coil spring to the holding member by adhesive or welding.

[0009] [Mode 2] A coil spring holding structure as described in [Mode 1], wherein the arrangement of the multiple protrusions on the holding member and the shape of the held portion, which is the part of the coil spring on the side of the holding member, are determined in a manner that enables the multiple protrusions and the coil spring to be combined so that the peripheral surfaces of the multiple protrusions and the held portion are positioned opposite each other while the variable diameter portion remains in the free state.

[0010] According to the above configuration, when the coil spring is held by the holding member, the coil spring can first be assembled to the holding member while keeping the diameter-changing portion of the coil spring in a free state and avoiding the multiple protrusions of the holding member. In this way, the task of assembling the coil spring to the holding member can be performed easily and smoothly. Then, by rotating the coil spring around the axis, the diameter-changing portion can be pushed aside by at least one of the multiple protrusions, thereby elastically deforming the diameter-changing portion. Therefore, according to the above configuration, the coil spring can be fixed and held to the holding member by the simple task of assembling the coil spring to the holding member in a free state and then rotating it.

[0011] [Aspect 3] A coil spring holding structure as described in [Aspect 1] or [Aspect 2], wherein the multiple protrusions are composed of three protrusions arranged on the same circle at intervals of less than 180 degrees.

[0012] According to the above configuration, the coil spring can be stably held by three-point support by the three protrusions provided on the holding member. [Mode 4] A holding structure for a coil spring according to any one of [Mode 1] to [Mode 3], wherein the protrusion has a cylindrical shape extending in the axial direction.

[0013] According to the above configuration, the circumferential surface of the convex portion and the circumferential surface of the coil spring can both be made arc-shaped, making it possible to create a structure in which large forces are less likely to act locally on the contact portion between the circumferential surface of the convex portion and the circumferential surface of the coil spring.

[0014] [Mode 5] [Mode 1] - [Mode 4], a coil spring holding method that is applicable to the coil spring holding structure described in any one of [Mode 1] to [Mode 4] and holds the coil spring with the holding member, comprising: an assembling step of assembling the coil spring with the holding member so that the peripheral surfaces of the multiple convex portions and the peripheral surface of a held portion that is the part of the coil spring on the side of the holding member are in an opposing positional relationship; and a rotating step of rotating the coil spring and the holding member relatively around the axis of the coil spring after the assembling step in a rotational direction such that the variable diameter portion is pushed aside by at least one of the multiple convex portions.

[0015] According to the above-mentioned holding method, by assembling the coil spring with the holding member and then rotating the holding member, the diameter changing portion can be elastically deformed by at least one of the multiple protrusions pushing aside the diameter changing portion. The restoring force of the diameter changing portion thus elastically deformed causes the circumferential surface of the coil spring to be pressed against the circumferential surfaces of the multiple protrusions. This pressing force allows the coil spring to be held by the multiple protrusions, i.e., the holding member. According to the above-mentioned holding method, the coil spring can be fixed and held by the holding member by the simple operation of assembling the coil spring with the holding member and then rotating the holding member. Effect of the Invention

[0016] According to the present invention, the coil spring can be easily held at a predetermined position on the holding member. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view showing a holding structure for a coil spring according to an embodiment; [Diagram 2] FIG. 4 is a plan view of the holding member of the embodiment. [Diagram 3] 3 is a cross-sectional view of the holding member taken along line 3-3 in FIG. 2. [Figure 4] FIG. 2 is a plan view of the coil spring of the embodiment. [Diagram 5]FIG. [Figure 6] 11 is a plan view showing a state in which the coil spring and the holding member are combined. FIG. [Figure 7] 13 is a plan view showing a coil spring and a holding member during rotation. FIG. [Figure 8] 11 is a plan view showing a state in which the coil spring is held by a holding member. FIG. [Figure 9] FIG. 11 is a plan view showing a coil spring holding structure according to a modified example. [Figure 10] 13 is a plan view showing a state in which the coil spring and the holding member of the modified example are combined. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of a coil spring holding structure and a coil spring holding method will be described. As shown in FIG. 1, in the holding structure according to this embodiment, a coil spring 10 is held by a holding member 20.

[0019] <Retaining material> As shown in FIGS. 1 to 3, the holding member 20 has a flat base portion 21 and three protrusions 22. As shown in FIG.

[0020] The three protrusions 22 are provided to protrude from a surface 211 of the base 21 on the side that holds the coil spring 10 (FIG. 1). The three protrusions 22 are arranged at 120 degree intervals on the same circle whose center is point C1 (FIG. 2). Each protrusion 22 has a cylindrical shape extending in the direction in which the axis L1 of the coil spring 10 extends (hereinafter referred to as the axis L1 direction).

[0021] <Coil springs> 1, coil spring 10 is a so-called coiled wave spring in which a corrugated spring wire (steel in this embodiment) that corrugates in the extension direction is spirally wound in a right-handed manner. Coil spring 10 is composed of an effective winding portion 101, which is a portion that acts as a spring, and an end winding portion 102 provided at one end in the direction of axis L1.

[0022] The coil spring 10 comprises a base portion 13 and a variable diameter portion 14 . <Base section> 4 and 5, base portion 13 extends in the direction of axis L1 with the same coil diameter. Base portion 13 constitutes the portion of coil spring 10 other than variable diameter portion 14. In detail, base portion 13 is constituted by the entire effective winding portion 101 (see FIG. 1) and a part of end winding portion 102 (specifically, the portion on the effective winding portion 101 side).

[0023] <Variable diameter part> Variable diameter portion 14 constitutes a portion of end winding portion 102 (see FIG. 1) on the extended end 15 side. In a free state where it is not elastically deformed, variable diameter portion 14 has a shape in which the coil diameter gradually changes in one direction (in this embodiment, the direction in which the coil diameter becomes smaller) toward extended end 15. This variable diameter portion 14 has a shape that protrudes from the inner circumferential surface of base portion 13 toward the radially inward direction of coil spring 10.

[0024] Hereinafter, as shown in FIG. 4, the diameter of a circle tangent to the inner peripheral surface of the base portion 13 is defined as the "coil inner diameter R1". In addition, the diameter of a circle centered on the axis L1 and tangent to the inner peripheral surface of the base end portion 16 of the diameter-changing portion 14 is defined as the "base end diameter R2". In addition, the diameter of a circle centered on the axis L1 and tangent to the inner peripheral surface of the extended end 15 of the diameter-changing portion 14 is defined as the "tip diameter R3". In addition, as shown in FIG. 2, the diameter of a circle extending to surround the three protrusions 22 and tangent to the outer peripheral surfaces of the three protrusions 22 is defined as the "protrusion diameter R4".

[0025] In this embodiment, as shown in FIG. 2 or 4, the arrangement of the three protrusions 22 on the retaining member 20 and the shape of each part of the coil spring 10 are determined so as to satisfy the following [Configuration A] to [Configuration C].

[0026] [Configuration A] The coil inner diameter R1 and the base end diameter R2 are approximately equal (R1=R2). [Configuration B] The tip diameter R3 is smaller than the base diameter R2 (R3 <R2)。 [Configuration C] The convex portion diameter R4 is larger than the tip diameter R3 and smaller than the coil inner diameter R1 (R3 <R4<R1)。

[0027] 6 shows an example of a state in which the coil spring 10 in a free state in which each part is not elastically deformed is combined with the holding member 20. As shown in FIG. 6, the three protrusions 22 can be combined with the coil spring 10 so that the outer circumferential surfaces of the three protrusions 22 and the inner circumferential surface of the held portion 103 (see FIG. 5) of the coil spring 10 face each other while the diameter changing portion 14 is in a free state in which the diameter changing portion 14 is not elastically deformed. In this embodiment, the arrangement of the three protrusions 22 on the holding member 20 and the shape of the held portion 103, which is the portion of the coil spring 10 on the holding member 20 side, are determined so as to realize such a configuration. Note that, as shown in FIG. 5, the held portion 103 includes the diameter changing portion 14 and a portion of the base portion 13 on the diameter changing portion 14 side.

[0028] The procedure for holding the coil spring 10 of this embodiment in the holding member 20 will be described below. <Combination process> When the coil spring 10 is held by the holding member 20, an assembly step is first performed.

[0029] In the assembling process, the coil spring 10 is assembled to the holding member 20 so that the outer peripheral surfaces of the three protrusions 22 face the inner peripheral surface of the held portion 103 of the coil spring 10. Specifically, first, the coil spring 10 and the holding member 20 are aligned so that the positional relationship between the coil spring 10 and the three protrusions 22 of the holding member 20 is as shown in FIG. 6. Thereafter, the coil spring 10 is pressed into the holding member 20, whereby the coil spring 10 is assembled to the holding member 20.

[0030] According to this embodiment, through such operations, it is possible to assemble the coil spring 10 to the holding member 20 while keeping the variable diameter portion 14 of the coil spring 10 in a free state and avoiding the three protruding portions 22 of the holding member 20. This makes it possible to assemble the coil spring 10 to the holding member 20 simply and smoothly.

[0031] <Rotation process> After the combining step, a rotating step is performed. In the rotating process, the coil spring 10 and the retaining member 20 are rotated relatively around the axis L1 in a rotation direction (the direction indicated by the arrow A in FIG. 6) in which the diameter-changing portion 14 is pushed aside by at least one of the three protrusions 22.

[0032] 6 to 8, the right-handed coil spring 10 is rotated counterclockwise relative to the retaining member 20. Then, the rotation of the coil spring 10 is stopped at a position before the protrusion 22 reaches the extended end 15 of the diameter-changing portion 14 (the position shown in FIG. 8).

[0033] In this rotation process, as the coil spring 10 rotates, the diameter change portion 14 is pushed aside by the protruding portion 22 in accordance with the shape of the inner peripheral surface of the diameter change portion 14, as shown by the arrow B in Figs. 7 and 8, so that the diameter change portion 14 gradually elastically deforms radially outward. At this time, the restoring force of the elastically deformed diameter change portion 14 generates a force pressing the inner peripheral surface of the coil spring 10 against the outer peripheral surfaces of the three protruding portions 22, and this pressing force can be gradually increased. Then, by stopping the rotation of the coil spring 10 at a position before the protruding portion 22 reaches the extended end 15 of the diameter change portion 14, the pressing force remains in a moderately large state. In this embodiment, the pressing force causes the coil spring 10 to be held by the three protruding portions 22, i.e., the holding member 20.

[0034] According to this embodiment, the coil spring 10 can be easily fixed and held in a position determined by the protrusions 22 by using the three protrusions 22, without joining the coil spring 10 to the holding member 20 by adhesive or welding. Moreover, the holding structure for holding the coil spring 10 on the holding member 20 can be realized through a simple operation of combining the coil spring 10 with the holding member 20 in a free state and then rotating it.

[0035] <Action and effect> According to this embodiment, the following advantageous effects can be obtained. (1) The coil spring 10 is composed of a diameter-changing portion 14 and a base portion 13. In a free state where the diameter-changing portion 14 is not elastically deformed, the diameter of the coil spring 10 gradually changes in one direction toward the extended end 15 of the coil spring 10, and the diameter-changing portion 14 protrudes from the inner peripheral surface of the base portion 13 toward the radially inward direction of the coil spring 10. Three protrusions 22 are provided on a surface 211 of the holding member 20 on the side that holds the coil spring 10. In the held state (the state shown in FIG. 8 ), the outer peripheral surfaces of the three protrusions 22 are pressed against the inner peripheral surface of the coil spring 10, and the diameter-changing portion 14 is pushed aside by the protrusions 22, so that the diameter-changing portion 14 is elastically deformed toward the radially outward direction of the coil spring 10. According to this embodiment, the coil spring 10 can be easily fixed and held at a position determined by the three protrusions 22 by utilizing the three protrusions 22, without joining the coil spring 10 to the holding member 20 by adhesion or welding.

[0036] (2) In this embodiment, it is possible to assemble the three protrusions 22 and the coil spring 10 so that the outer peripheral surfaces of the three protrusions 22 face the inner peripheral surface of the held portion 103 while the diameter-changing portion 14 remains in a free state. This makes it possible to easily and smoothly assemble the coil spring 10 to the holding member 20.

[0037] (3) The three protrusions 22 are arranged on the same circle at intervals of 120 degrees. Therefore, the coil spring 10 can be stably held by three-point support by the three protrusions 22 provided on the holding member 20.

[0038] (4) The protrusion 22 has a cylindrical shape extending in the direction of the axis L1. This allows the outer circumferential surface of the protrusion 22 and the inner circumferential surface of the coil spring 10 to be both arc-shaped, making it possible to achieve a structure in which a large force is unlikely to act locally on the contact portion between the outer circumferential surface of the protrusion 22 and the inner circumferential surface of the coil spring 10.

[0039] (5) Through the assembling step and the rotating step, the coil spring 10 is held by the holding member 20. Therefore, the coil spring 10 can be fixed to and held by the holding member 20 by a simple operation of assembling the coil spring 10 with the holding member 20 and then rotating the coil spring 10.

[0040] <Modification> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0041] In the combining step, the three protrusions 22 and the coil spring 10 may be combined such that the outer peripheral surfaces of the three protrusions 22 face the inner peripheral surface of the held portion 103 with the variable diameter portion 14 elastically deformed. As long as such an operation is possible, the arrangement of the three protrusions 22 on the holding member 20 and the shape of the held portion 103 of the coil spring 10 may be changed as desired.

[0042] In this case, although it is necessary to elastically deform diameter changing portion 14 in the assembling step, coil spring 10 can be assembled to retaining member 20 by elastically deforming diameter changing portion 14 with a small force. Moreover, in the subsequent rotating step, coil spring 10 is rotated relative to retaining member 20 to increase the amount of elastic deformation of diameter changing portion 14, and the pressing force that presses the inner circumferential surface of coil spring 10 against the outer circumferential surfaces of three protruding portions 22 can be appropriately increased.

[0043] The intervals between the three protrusions 22 are not limited to 120 degrees and can be changed as desired. The three protrusions 22 may be arranged on the same circle at intervals of less than 180 degrees.

[0044] The convex portion 22 may have any shape, such as an elliptical cylinder, a semicircular cylinder, or a rectangular cylinder. The holding member 20 is not limited to having three protrusions 22, but may have two protrusions 22, or four or more protrusions 22.

[0045] The shape of the surface 211 of the base 21 that holds the coil spring 10 is not limited to a flat surface, but may be changed as desired, for example, to a curved surface. As shown in an example in Figures 9 and 10, a holding structure can be adopted in which the outer circumferential surface of the coil spring 30 is pressed against the outer circumferential surfaces of a plurality of protrusions 42, thereby holding the coil spring 30 by the holding member 20.

[0046] In this case, in a free state where it is not elastically deformed, diameter-changing portion 34 has a shape in which the coil diameter gradually increases toward extended end 35 of coil spring 30. Diameter-changing portion 34 has a shape that protrudes radially outward of coil spring 30 from the outer circumferential surface of base portion 33. Three protrusions 42 are arranged to surround the periphery of coil spring 30.

[0047] According to the above configuration, in the held state, the restoring force of the elastically deformed diameter-changing portion 34 can cause the outer circumferential surface of the coil spring 30 to be pressed against the outer circumferential surfaces of the multiple protrusions 42. This pressing force can hold the coil spring 30 in the multiple protrusions 42, i.e., the holding member 40. Therefore, the coil spring 30 can be easily fixed and held in a position determined by the multiple protrusions 42 by using the multiple protrusions 42, without joining the coil spring 30 to the holding member 40 by adhesion or welding.

[0048] In the above configuration, when the coil spring 30 is held by the holding member 40, the coil spring 30 may be combined with the holding member 40 as shown in Fig. 10, and then rotated about the axis L2 relative to the holding member 40 as shown in Fig. 9. This allows the diameter-changing portion 34 to be elastically deformed by being pushed aside by the protrusions 42, so that the outer circumferential surface of the coil spring 30 is pressed against the outer circumferential surfaces of the multiple protrusions 42 by the restoring force of the diameter-changing portion 34. This pressing force allows the coil spring 30 to be held by the multiple protrusions 42, i.e., the holding member 40.

[0049] In this case, as shown in Figure 9, it is preferable that the multiple protrusions 42 and the coil spring 30 can be combined so that the outer peripheral surfaces of the multiple protrusions 42 and the coil spring 30 are in an opposing positional relationship while the variable diameter portion 34 remains in a free state without elastic deformation.

[0050] According to this configuration, the coil spring 30 can be fixed and held by the holding member 40 by the simple operation of combining the coil spring 30 with the holding member 40 in a free state and then rotating it.

[0051] The coil spring holding structure and the coil spring holding method according to the above embodiment are not limited to being applied to right-handed coil springs, but can also be applied to left-handed coil springs. In this case, in the rotation step, the left-handed coil spring may be rotated clockwise relative to the holding member.

[0052] The coil spring holding structure and the coil spring holding method according to the above-described embodiments are not limited to application to coil springs that are coiled wave springs, but can also be applied to coil springs in which the spring wire is wound in a simple spiral shape.

[0053] The coil spring holding structure and the coil spring holding method according to the above-described embodiment can be applied to coil springs made of metal materials such as hard steel wire, piano wire, and stainless steel wire, as well as to coil springs made of resin materials. [Explanation of symbols]

[0054] 10...Coil spring 101...Effective winding section 102…Seat roll 103…Holded part 13…Base section 14...Variable diameter section 15...Extended end 16...Proximal part 20...Retaining member 21...Base 211...face 22…Convex part 30…Coil spring 33…Base section 34...Variable diameter section 35…Extended end 40...Retaining member 42…Convex part

Claims

1. A holding structure for holding a coil spring by a holding member, The coil spring includes a variable diameter portion that constitutes an end portion in an axial direction, and a base portion that constitutes a portion other than the variable diameter portion, the variable diameter portion has a shape in which, in a free state in which it is not elastically deformed, a coil diameter gradually changes in one direction toward an extension end of the coil spring, and has a shape that protrudes in a radial direction of the coil spring from a peripheral surface of the base portion; the holding member is provided with a plurality of protrusions on a surface that holds the coil spring, a relative position of the coil spring and the holding member includes a first position and a second position obtained by rotating the coil spring around an axis line from the first position, In the first position, the coil spring is pushed toward the holding member while avoiding the plurality of protrusions, so that the coil spring is combined with the plurality of protrusions while remaining in the free state; In the second position, the peripheral surface of each of the plurality of protrusions is pressed against the peripheral surface of the coil spring, and the diameter-changing portion is elastically deformed in the radial direction in a manner to be pushed aside by at least one of the plurality of protrusions. Coil spring retention structure.

2. The plurality of protrusions are composed of three protrusions arranged on the same circle at intervals of less than 180 degrees. The coil spring holding structure according to claim 1 .

3. The convex portion has a cylindrical shape extending in the axial direction.

3. A coil spring holding structure according to claim 1 or 2.

4. A method for holding a coil spring, which is applied to the holding structure for a coil spring according to claim 1 or 2, and holds the coil spring by the holding member, comprising: a combining step of pressing the coil spring toward the holding member while avoiding the plurality of protrusions, thereby combining the coil spring with the plurality of protrusions while maintaining the free state; and a rotating step of rotating the coil spring and the holding member relatively around the axis of the coil spring in a rotation direction such that the diameter-changing portion is pushed aside by at least one of the plurality of protrusions after the assembling step. How to hold a coil spring.

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