JP7527744B2 - Compression spring - Google Patents

Description

The present invention relates to a compression spring.

A compression spring is known that includes two annular bases and a number of spring bodies that are circumferentially out of phase with each other and each extend linearly to connect the two bases (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 10-73138

Conventional compression springs like those described above tend to have stress concentrated at the base of the spring body when compressed, which makes them prone to sagging due to plastic deformation at the base.

Therefore, the object of the present invention is to provide a compression spring that is less likely to sag.

The compression spring of the present invention includes two pedestals that are spaced apart from each other in the axial direction along the axis and each form a ring centered on the axis, and a plurality of spring bodies that are arranged with a phase shift in the circumferential direction around the axis and each connects the two pedestals, and each of the spring bodies has two root parts that are arranged with a phase shift from each other in the circumferential direction, and an annular part that connects the two root parts within a region located between the two pedestals along the axial direction and forms a ring when viewed in the radial direction along a straight line perpendicular to the axis.

In the above configuration, the compression spring of the present invention is preferably a compression spring in which each of the annular portions is made up of two arc-shaped portions each connecting the two root portions.

In the above configuration, the compression spring of the present invention is preferably a compression spring in which each of the annular portions forms a flat annular shape having a major axis that is inclined with respect to the axial direction.

In the above configuration, the compression spring of the present invention is preferably a compression spring in which each of the annular portions has a notch on the inside of the branch portion from each of the base portions.

In the above configuration, the compression spring of the present invention is preferably a compression spring in which the base portion of each of the spring bodies is curved in the circumferential direction when the compression spring is in its natural state before compression.

The container dispenser of the present invention is preferably a container dispenser that has a built-in compression spring and an operating part that expands and contracts by compressing and releasing the compression spring, discharging the contents of the container by the expansion and contraction.

The present invention provides a compression spring that is less likely to sag.

FIG. 2 is a side view showing a compression spring according to an embodiment of the present invention. FIG. 2 is an exploded view of the compression spring shown in FIG. 1 . FIG. 3 is an enlarged view showing a part of the unit structure shown in FIG. 2 . 3A is an enlarged view showing a part of the unit pair structure shown in FIG. 2, FIG. 3B is an enlarged view showing a state when compressed from the state shown in FIG. 3A, and FIG. 3C is an enlarged view showing a state when further compressed from the state shown in FIG. 2 is a partially sectional side view showing an example of a container dispenser incorporating the compression spring shown in FIG. 1. 1A is an analysis result showing the stress distribution in the compression spring of the embodiment when compressed (displacement 6 mm), FIG. 1B is an analysis result showing the stress distribution when further compressed from the state shown in FIG. 1A (displacement 12 mm), and FIG. 1C is an analysis result showing the stress distribution when further compressed from the state shown in FIG. 1B (displacement 18 mm). 7 is an analysis result corresponding to FIG. 6 for a compression spring of a comparative example.

The following describes an embodiment of the present invention with reference to the drawings.

As shown in Figures 1 and 2, a compression spring 1 according to one embodiment of the present invention is a synthetic resin spring having a unit pair continuous structure 4 made up of three unit pair structures 3. Each unit pair structure 3 is made up of a pair of unit structures 2 with different winding directions. Each unit structure 2 has three spring bodies 5 and two bases 6. Note that Figures 1 and 2 show the reference symbols for the spring bodies 5 and bases 6 for only one unit structure 2.

As shown in Figs. 1 to 3, each unit structure 2 has two pedestals 6 that are spaced apart from each other in the axial direction along the axis O and each form a ring centered on the axis O, and a plurality of spring bodies 5 that are arranged with a phase shift in the circumferential direction around the axis O and each connects two pedestals 6. Each spring body 5 has two root parts 5a that are arranged with a circumferential shift from each other, and an annular part 5b that connects the two root parts 5a in a region located between the two pedestals 6 along the axial direction (hereinafter also referred to as the inter-pedestal annular region) and forms a ring when viewed in the radial direction along a straight line perpendicular to the axis O. Note that the number of spring bodies 5 included in each unit structure 2 is three in this embodiment as described above, but it may be two or four or more. The detailed structure of each unit structure 2 will be described below.

Each pedestal 6 is in the shape of a circular flat plate. The two pedestals 6 are identical in shape and size. The multiple spring bodies 5 are identical in shape and size and are arranged at equal intervals in the circumferential direction. The multiple spring bodies 5 are also arranged so as not to interfere with each other when the unit structure 2 is compressed in the axial direction.

As shown in FIG. 3, the root portion 5a of each spring body 5 is curved in the circumferential direction in the natural state before compression of the compression spring 1. More specifically, each root portion 5a protrudes from the base 6 in the axial direction within the annular region between the bases, and curves in the circumferential direction toward the side where the opposite root portion 5a is located. Note that each root portion 5a is not limited to a configuration in which it protrudes from the base 6 in the axial direction (i.e., the angle between the base 6 and the root portion 5a is a right angle). In order to suppress stress concentration on the root portion 5a when the compression spring 1 is compressed, it is preferable that the angle between the base 6 and the root portion 5a is as close to a right angle as possible. By configuring each root portion 5a to be curved in the circumferential direction, the angle between the base 6 and the root portion 5a can be set to a right angle or an angle closer to a right angle, thereby suppressing stress concentration on the root portion 5a.

The two base portions 5a of each spring body 5 have shapes and sizes that are rotationally symmetrical with respect to the center of the annular portion 5b in the developed view.

Each annular portion 5b is made up of two arc-shaped portions 5c, each of which connects two base portions 5a and forms an arc in an exploded view. The two arc-shaped portions 5c are curved in opposite directions to each other and have a shape and size that are rotationally symmetrical about the center of the annular portion 5b. Note that each arc-shaped portion 5c may be configured to form an arc shape other than a circular arc.

Each annular portion 5b is a flattened ring having a long axis that is inclined relative to the axial direction in the developed view. The two arc-shaped portions 5c have shapes and sizes that are symmetrical to each other with respect to the long axis.

Each annular portion 5b has a notch 5d on the inside of the branched portion from the base portion 5a. In other words, a notch 5d is provided at each of two locations (intersections of the inner peripheral edge and the long axis) where the two arc-shaped portions 5c join on the inner peripheral edge of each annular portion 5b. Each notch 5d is U-shaped in the developed view. The two notches 5d have shapes and sizes that are rotationally symmetrical to each other about the center of the annular portion 5b.

Each annular portion 5b is spaced apart from the two pedestals 6 when the compression spring is in its natural state. In other words, each arc-shaped portion 5c forms a predetermined distance in the axial direction with respect to the opposing pedestal 6 when the compression spring is in its natural state.

When each spring body 5 is compressed in the axial direction, it elastically deforms so that the annular portion 5b falls in a direction in which the long axis of the annular portion 5b approaches a direction perpendicular to the axial direction, as shown in Figures 4(a) to (c). When each spring body 5 is compressed in the axial direction, the annular portion 5b first falls and comes into contact with the two pedestals 6, as shown in Figure 4(b). When each spring body 5 is further compressed in the axial direction, it elastically deforms so that the annular portion 5b is sandwiched between the two pedestals 6 and crushed in the axial direction, as shown in Figure 4(c).

According to this embodiment, each spring body 5 can bear the load not only at the two root portions 5a but also at the annular portion 5b (two arc-shaped portions 5c), so stress concentration at the root portion 5a can be suppressed. Therefore, it is possible to make it difficult for the root portion 5a to sag due to plastic deformation (reduction in the axial length of the compression spring 1 in its natural state). In particular, after the annular portion 5b abuts against the two pedestals 6 during compression, the annular portion 5b can directly bear the compressive load from the two pedestals 6, so that the load bearing rate at the annular portion 5b can be increased and stress concentration at the root portion 5a can be effectively suppressed.

Furthermore, according to this embodiment, the two root portions 5a of each spring body 5 are symmetrical to each other, and the two arc-shaped portions 5c are symmetrical to each other, so that the load during compression can be better dispersed, thereby further suppressing the concentration of stress on the root portion 5a.

As shown in Figures 1 and 2, each unit pair structure 3 is made up of a pair of unit structures 2 that are identical except for the winding directions of the multiple spring bodies 5, and the pair of unit structures 2 are adjacent to each other in the axial direction and are connected together as one unit. Note that "different winding directions" means that when viewed toward one side in the axial direction, in one unit structure 2, each spring body 5 is right-handed (i.e., the rear root part 5a is located to the right of the front root part 5a), and in the other unit structure 2, each spring body 5 is left-handed (i.e., the rear root part 5a is located to the left of the front root part 5a).

Each unit pair structure 3 is a plane-symmetrical structure with respect to a plane that passes through the axial center and is perpendicular to the axis O. However, the unit pair structure 3 is not limited to a plane-symmetrical structure. In other words, in each unit pair structure 3, the orientation of one unit structure 2 can be changed around the axis O independently of the orientation of the other unit structure 2.

When an axial compressive load is applied to each unit pair structure 3 as shown by the thick arrow in FIG. 1, the base 6 located at the axial center of the unit pair structure 3 rotates in the circumferential direction as shown by the hollow arrow in FIG. 1, thereby allowing the multiple spring bodies 5 to expand in the circumferential direction instead of the radial direction. Therefore, according to this embodiment, it is possible to suppress radial expansion of the compression spring 1 when compressed. Note that this effect can be achieved even if each unit pair structure 3 is not a structure that is plane-symmetrical with respect to a plane that passes through the axial center and is perpendicular to the axis O.

The unit pair continuous structure 4 is made up of multiple unit pair structures 3, and is a structure in which multiple unit pair structures 3 are lined up in the axial direction and connected together. Therefore, according to this embodiment, a large expansion and contraction stroke amount corresponding to the number of unit pair structures 3 can be ensured. Note that, as described above, the number of unit pair structures 3 included in the unit pair continuous structure 4 is three in this embodiment, but it may be two, four or more.

As shown in FIG. 5, the compression spring 1 can be used in a container dispenser 10 capable of dispensing the contents of a container 11. The container dispenser 10 has an operating section 12 that incorporates the compression spring 1 and expands and contracts by compressing the compression spring 1 in the axial direction (the direction along the axis O, as described above) (hereinafter also referred to as the compression operation) and releasing it, thereby dispensing the contents of the container 11 through this expansion and contraction.

The container dispenser 10 is a commonly known push-down head type pump in which the operating unit 12 includes a push-down head 13. Note that the container dispenser 10 is not limited to push-down head type pumps.

All components of the container dispenser 10, including the compression spring 1, are made of synthetic resin. Therefore, the container dispenser 10 has excellent recyclability and can be disposed of as a recycled product without separation.

The operating unit 12 has a built-in compression spring 1 and an expandable structure 12a that expands and contracts in the axial direction by compressing and releasing the compression operation. The expandable structure 12a is composed of a push-down head 13, a cylindrical stem 14 centered on axis O that is integrally connected to the push-down head 13, an attachment cap 15, and a stem retaining member 16 that is fixed to the container 11 by the attachment cap 15. The push-down head 13 is provided radially outward from the stem 14 and has a cylindrical peripheral wall 13a centered on axis O. The attachment cap 15 is provided radially outward from the stem 14 and has a cylindrical guide wall 15a centered on axis O that can guide the peripheral wall 13a in the axial direction.

The compression spring 1 is disposed in an annular space S surrounded by the stem 14, the peripheral wall 13a, and the guide wall 15a. The compression spring 1 is held in the axial direction by being sandwiched between the lower surface of the push-down head 13 and the upper surface of the stem retaining member 16.

According to this embodiment, the compression spring 1 is resistant to sagging, making it possible to realize a highly durable dispenser for containers 10. In addition, according to this embodiment, the compression spring 1 is resistant to radial expansion when compressed, making it possible to easily realize a compact dispenser for containers 10.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the invention.

Therefore, the compression spring 1 of the above-described embodiment can be modified in various ways, for example as described below.

The compression spring 1 of the above-mentioned embodiment can be modified in various ways as long as it is a compression spring 1 that includes two pedestals 6 that are spaced apart from each other in the axial direction along the axis O and each form a ring centered on the axis O, and a plurality of spring bodies 5 that are arranged with a phase shift in the circumferential direction around the axis O and each connects two pedestals 6, and each spring body 5 has two root portions 5a that are arranged with a circumferential shift from each other, and an annular portion 5b that connects the two root portions 5a in an area located between the two pedestals 6 along the axial direction and forms a ring when viewed in the radial direction along a straight line perpendicular to the axis O.

For example, the base 6 may have an annular shape other than a circular ring shape. Furthermore, the compression spring 1 is not limited to a configuration having a unit pair continuous structure 4, and may have, for example, one unit pair structure 3. The compression spring 1 is not limited to a configuration having at least one unit pair structure 3, and may have, for example, one unit structure 2. Each annular portion 5b is not limited to a configuration consisting of two arc-shaped portions 5c, is not limited to a configuration forming a flat annular shape, and is not limited to a configuration having a notched portion 5d. Each root portion 5a of each spring body 5 is not limited to a configuration curved in the circumferential direction.

In addition, it is preferable that the compression spring 1 of the above-mentioned embodiment is a compression spring 1 in which each annular portion 5b is composed of two arc-shaped portions 5c each of which connects two root portions 5a.

In the above-described embodiment, the compression spring 1 is preferably a compression spring 1 in which each annular portion 5b is a flattened annular portion having a major axis that is inclined relative to the axial direction.

In the above-described embodiment, the compression spring 1 is preferably a compression spring 1 in which each annular portion 5b has a notch portion 5d on the inside of the branch portion from each base portion 5a in the above configuration.

In the above-described embodiment, the compression spring 1 is preferably a compression spring 1 in which the root portion 5a of each spring body 5 is curved in the circumferential direction in the natural state before compression of the compression spring 1.

Furthermore, the container dispenser 10 of the above-mentioned embodiment can be modified in various ways as long as it is a container dispenser 10 having a compression spring 1.

However, it is preferable that the container dispenser 10 of the above-mentioned embodiment is a container dispenser 10 having an operating part 12 that compresses the compression spring 1 and releases the compression spring 1 to dispense the contents of the container 11.

Moreover, it is more preferable that the container dispenser 10 of the above-mentioned embodiment is a container dispenser 10 having an operating part 12 that incorporates a compression spring 1 and expands and contracts by compressing and releasing the compression spring 1, thereby discharging the contents of the container 11.

As an example of the present invention, the stress distribution during compression of the compression spring shown in Figure 1 was analyzed by computer simulation. The results are shown in Figures 6(a) to (c). As a comparative example, an analysis was also performed on a compression spring that had a linear portion instead of an annular portion. The results are shown in Figures 7(a) to (c). This analysis confirmed that stress was concentrated on the inner curved portion of the base of the spring body in both the example and the comparative example.

The stress values at the inside of the curved root portion obtained by the above analysis are shown in Table 1. It can be seen that the embodiment having the annular portion can significantly suppress the stress concentration at the root portion, especially when it is compressed greatly.

REFERENCE SIGNS LIST 1 compression spring 2 unit structure 3 unit pair structure 4 unit pair continuous structure 5 spring body 5a root portion 5b annular portion 5c arc-shaped portion 5d cutout portion 6 base 10 container dispenser 11 container 12 operating portion 12a telescopic structure 13 push-down head 13a peripheral wall 14 stem 15 mounting cap 15a guide wall 16 stem removal prevention member O axis S annular space

Claims (6)

The rotor includes two pedestals spaced apart from each other in an axial direction along an axis line, each of which is annular about the axis line, and a plurality of spring bodies that are provided with a phase difference in a circumferential direction around the axis line, each of which connects the two pedestals,
A compression spring, wherein each of the spring bodies has two root portions that are offset from each other in the circumferential direction, and an annular portion that connects the two root portions within a region located between the two pedestals along the axial direction and forms a ring shape when viewed radially along a straight line perpendicular to the axis. The compression spring of claim 1, wherein each of the annular portions consists of two arcuate portions each connecting the two root portions. The compression spring according to claim 1 or 2, wherein each of the annular portions is a flattened annular portion having a major axis inclined relative to the axial direction. The compression spring according to any one of claims 1 to 3, wherein each of the annular portions has a notch on the inside of the branch portion from each of the base portions. The compression spring according to any one of claims 1 to 4, wherein the root portion of each of the spring bodies is curved in the circumferential direction when the compression spring is in its natural state before compression. A dispenser for a container that incorporates a compression spring according to any one of claims 1 to 5 and has an operating part that expands and contracts by compressing and releasing the compression spring, discharging the contents of the container by the expansion and contraction.