Compression spring

Abstract

To provide a compression spring capable of restraining a lateral displacement amount at the time of elastic deformation.SOLUTION: A compression spring 1 has a unit pair structure 3 comprising a pair of unit structures 2. The unit structure 2 has: a first annular member 2a and a second annular member 2b separated from each other in an axial direction; and three spring members 2c phase-displaced from each other in a peripheral direction, and each linearly extending from a first end 2c1 communicated with the first annular member 2a to a second end 2c2 communicated with the second annular member 2b at a position displaced from the first end 2c1 in the peripheral direction. The unit pair structure 3 has such a structure that the pair of first annular members 2a of the unit structure 2 is integrally communicated with each other, so that the pair of unit structures 2 is symmetrical to each other in a plane S vertical to an axial direction. The spring member 2c satisfies a following condition A under a state before elastic deformation. Condition A: 1.8≤W / T≤2.5. In this condition, W is a radial width of the first end 2c1 of the spring member 2c, and T is a width of the first end 2c1 of the spring member 2c in a front view of the spring member.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] There is known a compression spring having a unit pair structure composed of a pair of unit structures. The unit structure has a first annular member and a second annular member spaced apart from each other in the axial direction, and three spring members provided with a circumferential phase shift and linearly extending from a first end continuous with the first annular member to a second end continuous with the second annular member at a position circumferentially shifted from the first end with respect to the first end. The unit pair structure has a structure in which the first annular members of the pair of unit structures are integrally connected so that the pair of unit structures have a symmetrical shape with respect to a plane perpendicular to the axial direction. (See, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the unit pair structure of the compression spring as described above is axially compressed, there is a tendency to generate a lateral displacement in which, with respect to one of the second annular members, the other second annular member is displaced so as to shift in a predetermined direction (lateral direction) perpendicular to the axial direction. If the amount of lateral displacement generated during elastic deformation is excessive, not only does the load transmission efficiency in the compression direction decrease, but also plastic deformation is likely to occur in which the unit pair structure adapts to the lateral displacement due to continuous or repeated expansion and contraction in the compressed state. When a compression spring that is likely to cause such lateral plastic deformation is used, for example, in a discharge device, variations in the discharge amount are likely to occur.

[0005] Therefore, an object of the present invention is to provide a compression spring capable of suppressing the amount of lateral displacement during elastic deformation.

Means for Solving the Problem

[0006] One aspect of the present invention is as follows.

[0007] [1] It has a unit pair structure composed of a pair of unit structures, The unit structure includes a first annular member and a second annular member that are spaced apart from each other in the axial direction along a central axis, and three spring members that are provided with a phase shift in the circumferential direction around the central axis and linearly extend in a predetermined path from a first end connected to the first annular member to a second end connected to the second annular member at a position shifted in the circumferential direction with respect to the first end. The unit pair structure has a structure in which the first annular members of the pair of unit structures are integrally connected so that the pair of unit structures have symmetrical shapes with respect to a plane perpendicular to the axial direction. The spring member is a compression spring that satisfies the following condition A in a state before elastic deformation. Condition A: 1.8 ≦ W / T ≦ 2.5 However, W is the radial width of the first end of the spring member, and T is the width of the first end of the spring member in a direction perpendicular to the central axis in a front view of the spring member, which is a projection view when viewed from the center point of the predetermined path of the spring member toward the central axis.

[0008] [2] The spring member further satisfies the following condition B in a state before elastic deformation, and is the compression spring according to [1]. Condition B: 0.5 ≦ H / D ≦ 0.6 However, H is the axial width of the spring member, and D is the outer diameter of the unit pair structure.

[0009] [3] The spring member further satisfies the following condition C in a state before elastic deformation, and is the compression spring according to [1] or [2]. Condition C: 1.0 ≦ (W / T) × (H / D) ≦ 1.5 However, W is the radial width of the first end of the spring member, T is the width of the first end of the spring member, H is the axial width of the spring member, and D is the outer diameter of the unit pair structure.

[0010] [4] A compression spring according to any one of [1] to [3], a cylinder, a piston, and an operating member that discharges fluid through the inside of the cylinder by operating the piston against the cylinder in response to an operation against the elastic force of the compression spring. A discharge device having

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a compression spring capable of suppressing the lateral displacement amount during elastic deformation.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

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Figure 5

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Figure 8

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be exemplified and described with reference to the drawings.

[0014] As shown in FIGS. 1 to 2, in one embodiment of the present invention, the compression spring 1 has a unit pair structure 3 composed of a pair of unit structures 2 (two in a row in this embodiment). The unit structure 2 includes a first annular member 2a and a second annular member 2b that are spaced apart from each other in the axial direction along the central axis O, and three spring members 2c that are provided with a phase shift in the circumferential direction around the central axis O and linearly extend along a predetermined path P from a first end 2c1 connected to the first annular member 2a to a second end 2c2 connected to the second annular member 2b at a position circumferentially shifted with respect to the first end 2c1. The unit pair structure 3 has a structure in which the first annular members 2a of the pair of unit structures 2 are integrally connected so that the pair of unit structures 2 have a symmetrical shape with respect to a plane S perpendicular to the axial direction.

[0015] The spring member 2c may be configured to satisfy the following condition A in a state before elastic deformation. Condition A: 1.8 ≦ W / T ≦ 2.5 However, W is the radial width of the first end 2c1 of the spring member 2c, and T is the width (lateral width) of the first end 2c1 of the spring member 2c in a direction perpendicular to the central axis O in a front view of the spring member (see FIG. 1), which is a projection view when viewed from the center point C of the predetermined path P of the spring member 2c toward the central axis O of the compression spring 1. According to the above configuration, the lateral displacement amount X of the unit pair structure 3 during elastic deformation (see Fig. 5) can be suppressed, so that the compression spring 1 capable of suppressing the lateral displacement amount X during elastic deformation can be realized. The radial direction is the direction perpendicular to the central axis O. In the present embodiment, as will be described later, since the spring member 2c has a shape that is point-symmetric with respect to the center point C in the front view of the spring member, the radial width of the second end 2c2 of the spring member 2c may be used as W, and the lateral width of the second end 2c2 of the spring member 2c may be used as T. The first end 2c1 and the second end 2c2 of the spring member 2c may each have a shape having a corner radius 2c3 of an appropriate size in the front view of the spring member as shown in Fig. 1. In this case, as T, the lateral width in the case where the corner radius 2c3 is not provided (see the two-dot chain line in Fig. 2) may be used. The first end 2c1 and the second end 2c2 of the spring member 2c may each have a shape having a corner radius 2c3 of an appropriate size when viewed in the circumferential direction. In this case, as W, the radial width in the case where the corner radius 2c3 is not provided may be used.

[0016] The spring member 2c may be configured to satisfy the following condition B in the state before elastic deformation. Condition B: 0.5 ≦ H / D ≦ 0.6 However, H is the axial width of the spring member 2c, and D is the outer diameter of the unit pair structure 3. According to the above configuration, the compression spring 1 capable of suppressing the lateral displacement amount X during elastic deformation can be realized.

[0017] The spring member 2c may be configured to satisfy the following condition C in the state before elastic deformation. Condition B: 1.0 ≦ (W / T) × (H / D) ≦ 1.5 However, W is the radial width of the first end 2c1 of the spring member 2c, T is the lateral width of the first end 2c1 of the spring member 2c, H is the axial width of the spring member 2c, and D is the outer diameter of the unit pair structure 3. According to the above configuration, the compression spring 1 capable of suppressing the lateral displacement amount X during elastic deformation can be realized.

[0018] The spring member 2c may be configured to satisfy any combination of Condition A, Condition B, and Condition C in a state before elastic deformation. By satisfying more conditions, a higher suppression effect on the lateral displacement amount X can be obtained.

[0019] Note that the number of unit pair structures 3 provided in the compression spring 1 is not limited to two and can be set as appropriate. For example, it may be one, or may be three or more. The two unit pair structures 3 are continuous in the axial direction without shifting the phase in the circumferential direction from each other. However, it is not limited to this. For example, they may be configured to be continuous in the axial direction with a 180° phase shift in the circumferential direction. The three spring members 2c provided in the unit structure 2 may have substantially the same shape as long as their phases are shifted, and a slight difference in shape is allowed as long as any combination of Condition A, Condition B, and Condition C is satisfied in a state before elastic deformation.

[0020] The spring member 2c satisfies the following Condition D in a state before elastic deformation. Condition D: θ < θ1 and θ < θ2 However, θ is an acute angle on the acute angle side formed with respect to a perpendicular line that is perpendicular to the central axis O and connects the end of the predetermined path P on the first end 2c1 and the end of the predetermined path P on the second end 2c2 as viewed in the front view of the spring member. θ1 is an acute angle on the acute angle side formed with respect to the perpendicular line by the line that contacts the predetermined path P at the first end 2c1 as viewed in the front view of the spring member. θ2 is an acute angle on the acute angle side formed with respect to the perpendicular line by the line that contacts the predetermined path P at the second end 2c2 as viewed in the front view of the spring member.

[0021] The spring member 2c linearly extends along the predetermined path P while continuously changing the area of the cross-section perpendicular to the predetermined path P, and satisfies the following Condition E in a state before elastic deformation. Condition E: Sc < S1 and Sc < S2 However, Sc is the area of the cross-section passing through the center point C, S1 is the area of the cross-section passing through the first end 2c1, and S2 is the area of the cross-section passing through the second end 2c2.

[0022] The spring member 2c has a shape that is point-symmetrical with respect to the center point C in the front view of the spring member. Further, the spring member 2c has an S-shaped in the state before elastic deformation in the front view of the spring member. Note that the S-shaped means a shape that bends to one side once and then bends to the other side once from one end to the other end.

[0023] The unit pair structure 3 has an inner peripheral edge that forms a circular shape based on an equilateral triangle in a top view, with each vertex facing the center point C of the spring member 2c. According to the above configuration, even when the spring member 2c deforms so as to enter radially inward at the middle part in the length direction during compression of the compression spring 1, a substantial decrease in the inner diameter of the compression spring 1 can be suppressed.

[0024] The first annular member 2a and the second annular member 2b of the unit pair structure 3 have a circular outer peripheral edge in a top view, but are not limited thereto, and may have a polygonal outer peripheral edge, for example.

[0025] In consideration of the environment such as recyclability, when a resin product incorporating the compression spring 1 is formed only of a polyolefin resin such as polypropylene or polyethylene, it is preferable that the compression spring 1 is also formed of a polyolefin resin. Note that the compression spring 1 is not limited to a polyolefin resin, and may be formed of a resin other than a polyolefin resin, such as POM (polyoxymethylene), for example. By making the compression spring 1 resin-made, the recyclability when the compression spring 1 is incorporated into a resin product can be enhanced.

[0026] As shown in FIGS. 3 to 4, in the present embodiment, the discharge container 4 has a container body 5 having a mouth portion 5a, and a discharge device 6 attached to the mouth portion 5a for discharging the content as a fluid in the container body 5 according to an operation. The discharge device 6 includes a compression spring 1, a cylinder 8, a piston 10, and an operating member 11 that discharges the fluid through the inside of the cylinder 8 by operating the piston 10 with respect to the cylinder 8 according to an operation against the elastic force of the compression spring 1. According to the above configuration, by making the entire discharge device 6 made of resin (for example, made of polyolefin resin), a discharge container 4 with high recyclability can be realized. Further, by using the compression spring 1 that can suppress the lateral displacement amount X during elastic deformation, it is possible to make it difficult for the discharge amount to vary.

[0027] The operating member 11 includes a push-down head 7 that receives a push-down operation, a piston 10, and a stem 9 that is pushed down with the piston 10 with respect to the cylinder 8 by a push-down operation against the repulsive force of the compression spring 1 and rises with the piston 10 with respect to the cylinder 8 by the repulsive force of the compression spring 1 when the push-down operation is released. By the reciprocating motion, the fluid in the cylinder 8 is sent to the push-down head 7 and discharged through the push-down head 7. According to the above configuration, the discharge device 6 can be configured as a push-down head type pump. The discharge device 6 is not limited to a push-down head type pump, and may be configured as, for example, a trigger type pump.

[0028] The stem 9 extends through the radially inner side of the compression spring 1. According to the compression spring 1 that can suppress the lateral displacement amount X during elastic deformation, interference during the expansion and contraction operation of the compression spring 1 with respect to the stem 9 disposed on the radially inner side of the compression spring 1 can be suppressed, so that the compression spring 1 can be arranged with good space efficiency. Further, since the inner peripheral edge of the unit pair structure 3 forms a circular shape based on an equilateral triangle, the above interference can be suppressed.

[0029] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be variously modified without departing from the gist of the present invention.

Example

[0030] Regarding a compression spring as an example having a unit pair structure with a shape equivalent to the shape described in the above-described embodiment and shown in FIGS. 1 to 2, an analysis was performed to examine the influence of each of W / T, H / D, and (W / T)×(H / D) on the lateral displacement amount X. In the analysis, while changing the values of the above various parameters, as shown in FIG. 5, the lateral displacement amount X when an axial compression force was applied from the other end with one end in the axial direction of the example fixed was calculated. The example was made of a polyolefin resin. As a result, as shown in FIGS. 6 to 8, it was found that the lateral displacement amount X could be suppressed to be equal to or less than that of a conventional product (made of POM) within a range satisfying conditions A to C regarding W / T, H / D, and (W / T)×(H / D).

Explanation of Signs

[0031] 1 Compression spring 2 Unit structure 2a First annular member 2b Second annular member 2c Spring member 2c1 First end 2c2 Second end 2c3 Corner radius 3 Unit pair structure 4 Discharge container 5 Container body 5a Mouth part 6 Discharge device 7 Pushing head 8 Cylinder 9 Stem 10 Piston 11 Actuating member C Center point D Outer diameter H Axial width O Central axis P Predetermined path S Plane S1 Area S2 Area Sc Area T Width W Radial width X Lateral displacement amount θ Angle θ1 Angle θ2 angle

Claims

1. It has a unit pair structure composed of a pair of unit structures, wherein each unit structure includes a first annular member and a second annular member spaced apart from each other in an axial direction along a central axis, and three spring members provided with a phase shift in a circumferential direction around the central axis and linearly extending along a predetermined path from a first end connected to the first annular member to a second end connected to the second annular member at a position shifted in the circumferential direction with respect to the first end; the unit pair structure has a structure in which the first annular members of the pair of unit structures are integrally connected so that the pair of unit structures have a symmetrical shape with respect to a plane perpendicular to the axial direction; the spring member is a compression spring that satisfies the following condition A in a state before elastic deformation. Condition A: 1.8 ≤ W / T ≤ 2.5 where W is the radial width of the first end of the spring member, and T is the width of the first end of the spring member in a direction perpendicular to the central axis in a front view of the spring member, which is a projection view when viewed from the center point of the predetermined path of the spring member toward the central axis.

2. The compression spring according to claim 1, wherein the spring member further satisfies the following condition B in a state before elastic deformation. Condition B: 0.5 ≤ H / D ≤ 0.6 where H is the axial width of the spring member, and D is the outer diameter of the unit pair structure.

3. The compression spring according to claim 1, wherein the spring member further satisfies the following condition C in a state before elastic deformation. Condition C: 1.0 ≤ (W / T) × (H / D) ≤ 1.5 where W is the radial width of the first end of the spring member, T is the width of the first end of the spring member, H is the axial width of the spring member, and D is the outer diameter of the unit pair structure.

4. A discharge device, comprising the compression spring according to claim 1, a cylinder, a piston, and an operating member that discharges fluid through the inside of the cylinder by operating the piston with respect to the cylinder in response to an operation against the elastic force of the compression spring.

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