Spring, method for inserting spring, and jig for inserting spring

Abstract

To provide a spring that functions as a support member in a structure.SOLUTION: A spring has a first hook located at a first end, a second hook located at a second end opposite the first end, and a coil part between the first hook and the second hook. An outer diameter on the first end side is larger than an outer diameter on the second end side. The first hook is a rod that overlaps with the coil part in a direction parallel to a central axis of the coil part, and does not overlap with the central axis in the direction. The second hook is a rod that overlaps with the coil part in the direction, and may overlap with the central axis in the direction.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] One embodiment of the present invention relates to a spring, a tool and a method for inserting a spring into a structure such as a tube, or a method and a tool for inserting a spring into a tube whose outer diameter is smaller than the outer diameter of the spring. [Background technology]

[0002] A spring (coil spring) has the property that when torque is applied to increase the number of turns, the overall length increases and the outer diameter decreases, and when the torque is released, the spring returns to its original shape. By utilizing this property, the spring can be inserted into a structure such as a tube whose outer diameter is smaller than the spring. Since the spring inserted into the structure does not completely block the structure, it can function as a support member that holds a solid of a certain size within the tube while allowing the passage of fluids such as gas and liquid (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-142299 A [Patent Document 2] JP 2015-16425 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a spring having a novel structure. Alternatively, an object of the present invention is to provide a spring that functions as a support member in a structure such as a tube. Alternatively, an object of the present invention is to provide a method and a tool for inserting the above-mentioned spring into a tube whose outer diameter is smaller than that of the spring. [Means for solving the problem]

[0005] One embodiment of the present invention is a spring. The spring has a first hook located at a first end, a second hook located at a second end opposite the first end, and a coil portion between the first hook and the second hook. The outer diameter of the first end side is larger than the outer diameter of the second end side. The first hook is a rod that overlaps with the coil portion in a direction parallel to the central axis of the coil portion, but does not overlap with the central axis in said direction.

[0006] One embodiment of the present invention is a method of inserting a spring into a tube. The spring comprises a first hook located at a first end, a second hook located at a second end opposite the first end, and a coiled portion between the first and second hooks. The method includes placing the second end into the tube, and moving the spring into the tube while rotating the first hook about a central axis of the coiled portion while fixing the second end to increase the number of turns of the spring. The outer diameter of the first end side is larger than the outer diameter of the second end side and the inner diameter of the tube. The first hook is a rod that overlaps the coiled portion in a direction parallel to the central axis of the coiled portion and does not overlap the central axis in the method.

[0007] One embodiment of the present invention is a jig for inserting a spring into a tube. The jig includes a shaft and a base. The shaft has a slit at a first end and a grip portion at a second end. The base has a through hole in the center through which the shaft can pass and a linear groove that does not intersect with the through hole.

[0008] One embodiment of the present invention is a jig for inserting a spring into a tube. The jig includes a shaft having a slit at one end, a rotor having a through hole through which the shaft can pass, and a clamp bar attached to the rotor and having at least a portion extending in a direction parallel to the central axis of the through hole. The clamp bar has a slit at its tip. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 2 is a schematic side view of a spring according to an embodiment of the present invention. [Figure 1B] 2 is a schematic diagram of a first end of a spring according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic side view of a spring according to an embodiment of the present invention. [Figure 3A] FIG. 2 is a schematic side view of a spring according to an embodiment of the present invention. [Figure 3B] 2 is a schematic diagram of a first end of a spring according to an embodiment of the present invention. [Figure 4A] FIG. 2 is a schematic side view of a jig for inserting a spring into a structure according to an embodiment of the present invention. [Figure 4B] FIG. 2 is a schematic front view of a jig for inserting a spring into a structure according to an embodiment of the present invention. [Figure 5A] FIG. 2 is a schematic perspective view of a jig for inserting a spring into a structure according to an embodiment of the present invention. [Figure 5B] FIG. 2 is a schematic front view of a jig for inserting a spring into a structure according to an embodiment of the present invention. [Figure 6A] FIG. 2 is a schematic perspective view of a structure into which a spring is inserted according to an embodiment of the present invention. [Figure 6B] 5A to 5C are schematic side views showing a method of inserting a spring into a structure according to an embodiment of the present invention. [Figure 6C] 5A to 5C are schematic side views showing a method of inserting a spring into a structure according to an embodiment of the present invention. [Figure 7] 5A to 5C are schematic side views showing a method of inserting a spring into a structure according to an embodiment of the present invention. [Figure 8A] FIG. 2 is a schematic side view of a jig for inserting a spring into a structure according to an embodiment of the present invention. [Figure 8B] FIG. 2 is a schematic top view of a portion of a fixture for inserting a spring into a structure, according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, each embodiment of the invention disclosed in this application will be described with reference to the drawings. However, the present invention can be embodied in various forms without departing from the gist of the invention, and the present invention should not be interpreted as being limited to the description of the embodiments exemplified below.

[0011] In order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. In this specification and each drawing, elements having the same functions as those explained in the previous drawings may be given the same reference numerals, and duplicate explanations may be omitted.

[0012] In this specification and drawings, the same reference numerals are used to collectively represent multiple identical or similar components, and a hyphen and a natural number are added to each of the multiple components to distinguish them from one another. The same reference numerals and letters are used to distinguish each of multiple parts of a single component.

[0013] A spring according to one embodiment of the present invention, and a method and a tool for inserting the spring into a structure will be described below.

[0014] 1. Spring 1A shows a schematic side view of a spring 100 according to one embodiment of the present invention. The spring 100 is a so-called coil spring. The spring 100 is made of a wire containing a metal (a zero-valent metal) such as iron, aluminum, copper, chromium, molybdenum, tungsten, or titanium, or an alloy such as stainless steel, and the wire is wound in a coil shape around a central axis Ax shown by a dashed line in FIG. 1A. Hereinafter, the direction parallel to the central axis Ax is defined as the z direction, and the directions perpendicular to the z direction and perpendicular to each other are defined as the x direction and the y direction.

[0015] The spring 100 is composed of a coil portion 102 wound in a coil shape, a first hook 104 provided at one end (first end) of the wire, and a second hook 106 provided at one end (second end) of the wire located opposite to the first end. The outer diameter of the spring 100 is not constant throughout, and as shown in FIG. 1A, when the spring 100 is in a natural state, the outer diameter D1 on the first end side is larger than the outer diameter D2 on the second end side. Therefore, the coil portion 102 can be composed of a plurality of parts, and for example, the coil portion 102 can be composed of a first part 102-1 on the first end side, a second part 102-2 on the second end side, and an intermediate part 102-3 located between the first part 102-1 and the second part 102-2. The central axes of the first part 102-1, the second part 102-2, and the intermediate part 102-3 are substantially coaxial and coincide with the central axis Ax. The outer diameter D1 of the first portion 102-1 is constant or approximately constant along the central axis Ax, and similarly, the outer diameter D2 of the second portion 102-2 is constant or approximately constant along the central axis Ax, while the outer diameter of the intermediate portion 102-3 decreases from the outer diameter D1 to the outer diameter D2 as the distance from the first portion 102-1 increases.

[0016] Alternatively, as shown in FIG. 2, spring 100 may be configured such that the outer diameter of coil portion 102 gradually changes from D2 to D1 from the first end side to the second end side.

[0017] As shown in FIG. 1B, the wire is bent at the first end to form a first hook 104. Unlike the coil portion 102, in which the wire is curved, the first hook 104 is a straight rod. The first hook 104 overlaps with the portion other than the first hook 104, i.e., the coil portion 102, in a direction parallel to the central axis Ax (i.e., the z direction). The first hook 104 may extend in a direction perpendicular or substantially perpendicular to the central axis Ax (i.e., in the xy plane), or may extend so as to intersect with the xy plane (not shown). The first hook 104 does not overlap with the central axis Ax in the z direction. Furthermore, the length of the first hook 104 is shorter than the outer diameter D1.

[0018] More specifically, as shown in FIG. 1A and FIG. 1B, the spring 100 is configured so that not only the first hook 104 does not overlap with the central axis Ax in the z direction, but also the extension direction of the first hook 104 does not overlap (does not intersect) with the central axis Ax in the z direction. Alternatively, as shown in FIG. 3A and FIG. 3B, the spring 100 is configured so that the extension direction of the first hook 104 overlaps (intersects) with the central axis Ax in the z direction, but the first hook 104 itself does not overlap with the central axis Ax in the z direction. The end of the first hook 104 may overlap with the wire that wraps around it directly above (FIG. 1B), or, although not shown, it does not have to overlap with the wire that wraps around it directly above. As will be described later, by arranging the first hook 104 so that it does not overlap with the central axis Ax in the z direction, the spring 100 can be easily inserted into a tube having an inner diameter smaller than the outer diameter D1.

[0019] Similarly, as shown in FIG. 1C, the wire is bent at the second end to form a second hook 106. Like the first hook 104, the second hook 106 is also a straight rod and overlaps with the portion other than the second hook 106, i.e., the coil portion 102, in the z direction. However, the second hook 106 overlaps with the central axis Ax in the z direction. The second hook 106 may extend in a direction perpendicular or substantially perpendicular to the central axis Ax (i.e., in the xy plane), or, although not shown, may extend so as to intersect with the xy plane. The end of the second hook 106 may also overlap with the wire that wraps around directly below it (FIG. 1C), or, although not shown, may not overlap with the wire that wraps around directly below it. The extension directions of the first hook 104 and the second hook 106 when the spring 100 is at its natural length can be determined arbitrarily, and may be parallel or perpendicular to each other, or may intersect at any angle.

[0020] 2. Jig 4A and 4B are schematic side and front views of a jig 120 for inserting the spring 100 shown in FIG. 1A to FIG. 2, i.e., the spring 100 in which the first hook 104 does not overlap the central axis Ax and the extension direction of the first hook 104 does not intersect with the central axis Ax, into a structure such as a tube. As shown in these figures, the jig 120 mainly comprises a shaft 122, a grip portion 124, and a base 126. The jig 120 may further comprise a handle 128. All or a part of the shaft 122, the grip portion 124, the base 126, and the handle 128 may include a metal such as iron, aluminum, or copper, or an alloy such as stainless steel or brass, or may include a resin such as an epoxy resin, a phenolic resin, or a fluororesin. The resin may be a fiber-reinforced plastic including glass fiber, carbon fiber, or the like. By making all or part of the shaft 122, grip portion 124, base 126, and handle 128 contain resin, it is possible to provide a jig 120 that is lightweight and therefore has improved operability.

[0021] The shaft 122 extends linearly and has a notch (slit) 122a at one end. The notch 122a is formed to receive and engage with the second hook 106 provided at the second end of the spring 100. Therefore, the notch 122a is provided so that its width (length in a direction perpendicular to the extension direction of the notch 122a) and depth (length in the extension direction of the shaft 122) are equal to or greater than the diameter of the wire constituting the spring 100. Meanwhile, a grip portion 124 is provided at the other end of the shaft 122. The structure of the grip portion 124 is arbitrary, and as described later, it is sufficient to be configured so that the spring 100 inserted into the structure can be held with the second hook 106 of the spring 100 received in the notch 122a. Therefore, for example, the grip portion 124 may be a bar inclined from the extension direction of the shaft 122, or a T- or Y-shaped rod branched off from the shaft 122. Grip portion 124 may be integrated with shaft 122, or may be attached to shaft 122 as an independent member. Because grip portion 124 and shaft 122 are fixed, the relative distance and positional relationship between grip portion 124, shaft 122, and notch 122a does not change. Although not shown, a through hole through which the second hook of spring 100 passes may be provided at the end of shaft 122 instead of notch 122a.

[0022] The base 126 functions as a base material for gripping the first hook 104 of the spring 100 and applying a torque to the first hook 104 so as to increase the number of turns, thereby pushing out the spring 100 in the z direction while rotating around the central axis Ax. The shape of the base 126 may be disk-like, polygonal, or the contour in the xy plane may be composed of curves and straight lines. The base 126 is provided with a through hole through which the shaft 122 can pass, and thus the base 126 and the shaft 122 can rotate relatively with the shaft 122 inserted in the through hole, and can move relatively along the extension direction of the shaft 122. The handle 128 is connected or fixed to the base 126, and the base 126 can be rotated around the extension direction of the shaft 122 by using the handle 128. The configuration of the handle 128 can also be selected appropriately, and any configuration that can rotate the base 126 while attached to the shaft 122 may be adopted. 4A and 4B, it may be one or more rods extending perpendicularly to the extension direction of shaft 122 from the side of base 126, or it may be a steering wheel (not shown) provided on the grip part 124 side of base 126. Handle 128 may be integrated with base 126, or may be attached to base 126 as an independent member.

[0023] A linear groove 126a extending on the xy plane is provided on the surface of the base 126 (the surface opposite to the grip portion 124). The groove 126a is configured to receive and engage with the first hook 104 of the spring 100. Thus, similar to the notch 122a, the groove 126a is provided such that its width (length in a direction perpendicular to the direction in which the groove 126a extends) and depth (length in the direction in which the shaft 122 extends) are equal to or greater than the diameter of the wire of the spring 100. The base 126 is configured such that its maximum length (diameter if it is disc-shaped) D3 in the xy plane is smaller than the outer diameter D1 of the spring 100. Therefore, with the shaft 122 inserted into the spring 100 and the first hook 104 received in the groove 126a, the spring 100 can be pushed out in the z direction via the base 126, and interference with a structure such as a tube into which the spring 100 is inserted can be avoided.

[0024] Furthermore, in order to more reliably grip the first hook 104 when applying torque to the spring 100, the base 126 may be provided with an engagement portion 126b continuous with the groove 126a. The engagement portion 126b constitutes a part of the groove 126a, and is a portion that is not exposed from the base 126 in the z direction. In other words, the groove 126a may be formed so that the direction in which the surface of the base 126 extends (the x direction in FIG. 5B) intersects with the direction in which the bottom surface, indicated by the dotted line in FIG. 5B, extends. The engagement portion 126b is provided so that its height (length in the z direction) is equal to or greater than the diameter of the wire.

[0025] 3.How to insert the spring A tube is given as an example of a structure into which spring 100 is inserted, and a method of inserting spring 100 will be described with reference to the schematic perspective view of FIG. 6A, schematic side views of FIG. 4A and FIGS. 6B to 7, and schematic front view of FIG. 4B.

[0026] The inner diameter D4 of the tube 130 into which the spring 100 is inserted (see FIG. 6A) is larger than the outer diameter D2 of the second end of the spring 100, but smaller than the outer diameter D1 of the first end. Therefore, after the spring 100 is inserted into the tube 130, the spring 100 does not fall out of the tube 130. Also, since the spring 100 is made of wires, there are gaps between the wires. Therefore, it is possible to hold a solid object larger than the gaps between the wires when inserted into the tube 130 within the tube 130 without clogging the tube 130, and at the same time, it is possible to allow the passage of fluids such as liquids and gases.

[0027] First, as shown in Fig. 4A, the spring 100 is attached to the jig 120. That is, the shaft 122 is inserted into the through hole of the base 126, and then inserted into the spring 100. The first hook 104 and the second hook 106 of the spring 100 are accommodated in the groove 126a and the notch 122a, respectively. In this state, the central axis Ax of the coil portion 102 and the extension direction of the shaft 122 are approximately aligned.

[0028] Thereafter, the second end of the spring 100 is inserted into the tube 130 and moved in the z direction (FIG. 6B). Since the inner diameter D4 is smaller than the outer diameter D1, when the spring 100 is moved in the z direction, the tube 130 comes into contact with the middle portion 102-3 or the first portion 102-1 of the spring 100. In this state, the rotation of the grip portion 124 is fixed, and while moving the spring 100 in the z direction, the base 126 is rotated so that the number of turns of the spring 100 increases (see the dotted arrow in FIG. 4B). The base 126 may be rotated using the handle 128, which allows a larger torque to be applied to the spring 100. As described above, the second hook 106 provided at the second end of the spring 100 is received in the notch 122a, but the relative distance and positional relationship between the grip portion 124 and the notch 122a does not change. Additionally, the groove 126a of the base 126 accommodates the first hook 104 provided at the first end of the spring 100. Therefore, by rotating the base 126, the second hook 106 rotates without rotating the first hook 104, and as a result, the number of turns of the spring 100 can be increased.

[0029] As the number of turns of spring 100 increases, the outer diameter of spring 100 decreases from D1. Therefore, as spring 100 moves in the z direction, middle portion 102-3 and first portion 102-1 of spring 100 can be gradually inserted into tube 130. When the outer diameter of spring 100 finally reaches outer diameter D1' which is equal to or smaller than inner diameter D4 of tube 130 (FIG. 7), the entire spring 100 can be inserted into tube 130.

[0030] As described above, the groove 126a provided in the base 126 does not intersect with the through hole of the base 126 through which the shaft 122 passes, i.e., does not interfere with the through hole. Therefore, the groove 126a can rotate around the extension direction of the shaft 122 as the base 126 rotates. In addition, the first hook 104 of the spring 100 is provided so as not to overlap with the central axis of the coil part 102 in the z direction. Therefore, when the spring 100 is attached to the jig 120, the second hook 106 can be easily and reliably fixed to the notch 122a without being interfered with by the first hook 104. By rotating the base 126 with the first hook 104 and the second hook 106 accommodated in the groove 126a of the base 126 and the notch 122a of the shaft 122, respectively, a torque can be easily applied to the spring 100, the number of turns can be increased, and the outer diameter can be reduced. In particular, by accommodating the first hook 104 in the groove 126a, the contact area of ​​the first hook 104 with the base 126 becomes large, so that a large torque can be applied. Therefore, high work efficiency can be maintained even when a large spring 100 is inserted into the tube 130. Furthermore, since the shaft 122 and the first hook 104 do not interfere with each other, the outer diameter of the shaft 122 can be set large within the range of the minimum inner diameter of the spring 100 (the inner diameter of the second portion 102-2), so that the jig 120 is given high rigidity and a large torque can be applied to the spring 100. As a result, the spring 100 can be easily inserted and fixed into the tube 130 having an inner diameter D4 smaller than the outer diameter D1 in the natural state.

[0031] Thereafter, the torque applied to the spring 100 is released. As a result, a restoring force acts on the spring 100 to return it to its original state, and the outer diameter increases. However, since the outer diameter D1 of the spring 100 in its natural state is larger than the inner diameter D4, the outer diameter of the spring 100 maintains the inner diameter D4, and as a result, a large frictional force acts between the spring 100 and the tube 130. This frictional force prevents the spring 100 from falling off the tube 130, and also enables the retention of a solid object provided inside the tube 130.

[0032] 4.Modifications of the fixture As a modification of the jig 120, a schematic side view of a jig 140 for inserting the spring 100 shown in Fig. 3A and Fig. 3B, i.e., the spring 100 in which the first hook 104 does not overlap with the central axis Ax but the extension direction of the first hook 104 intersects with the central axis Ax, into a structure such as a tube is shown in Fig. 8A. As shown in Fig. 8A, the jig 140 mainly comprises a shaft 142, a rotor 146, and a clamp bar 150. The jig 140 may further comprise a handle 148. The shaft 142, the rotor 146, the handle 148, and the clamp bar 150 may also include the above-mentioned metal, alloy, or resin.

[0033] The shaft 142 extends linearly and has an engaging portion 142a at one end. The engaging portion 142a is formed to receive and engage with the second hook 106 provided at the second end of the spring 100, similar to the notch 122a. Therefore, there is no restriction on the shape of the engaging portion 142a. For example, the engaging portion 142a may be a notch as shown in FIG. 8A, or may be a through hole that penetrates the shaft 142, although not shown. When the engaging portion 142a is a notch, the width (length in a direction perpendicular to the direction in which the notch extends) and the depth (length in the direction in which the shaft 142 extends) are provided so as to be equal to or greater than the diameter of the wire constituting the spring 100. When the engaging portion 142a is a through hole, the engaging portion 142a is provided so as to be equal to or greater than the diameter of the wire. On the other hand, the other end of the shaft 142 serves to hold the spring 100 inserted into the structure with the second hook 106 of the spring 100 accommodated in the engagement portion 142a. Therefore, the other end of the shaft 142 may be rod-shaped as shown in FIG. 8A, or may have a shape similar to that of the grip portion 124 of the jig 120, although not shown.

[0034] The rotor 146 has a through hole through which the shaft 142 passes. This allows the shaft 142 and the rotor 146 to rotate relatively around the central axis of the rotor 146.

[0035] The clamp bar 150 is also connected to the rotor 146. The clamp bar 150 extends from the rotor 146 side to the engagement portion 142a side. The clamp bar 150 may extend in a direction parallel to the central axis of the through hole of the rotor 146 (z direction), or may extend at an angle inclined from the z direction. As shown in FIG. 8B, an engagement portion 150a is also provided at the tip of the clamp bar 150. The engagement portion 150a is formed to receive and engage with the first hook 104 provided at the first end of the spring 100. Therefore, there is no restriction on the structure of the engagement portion 150a, and the engagement portion 150a may be a cut as shown in FIG. 8B, or may be a through hole penetrating the clamp bar 150, although not shown. Like engaging portion 142a, when engaging portion 150a is a notch, it is provided so that its width (length in a direction perpendicular to the direction in which the notch extends) and depth (length in the direction in which clamp bar 150 extends) are equal to or greater than the diameter of the wire constituting spring 100. When engaging portion 150a is a through hole, engaging portion 150a is provided so that its diameter is equal to or greater than the diameter of the wire.

[0036] An optional handle 148 is coupled to the rotor 146. The provision of the handle 148 assists in the rotation of the rotor 146. The configuration of the handle 148 may also be selected as appropriate, and similar to the handle 128, any configuration may be used that allows the rotor 146 to be rotated while attached to the shaft 142. Similar to the jig 120, the handle 148 may be integral with the rotor 146, or may be attached to the rotor 146 as an independent member.

[0037] When using the jig 140 having the above-mentioned configuration, the spring 100 is inserted into the structure with the second hook 106 of the spring 100 housed in the engagement portion 142a. This makes it possible to suppress the overall rotation of the spring 100. Meanwhile, the first hook 104 is gripped by the engagement portion 150a provided at the tip of the clamp bar 150. In this state, the rotor 146 is rotated. The rotor 146 may be rotated using the handle 148, which allows a larger torque to be applied to the spring 100. As the rotor 146 rotates, the clamp bar 150 also rotates around the shaft 142, allowing a torque to be applied to the spring 100. As in the case of using the jig 120, by rotating the rotor 146 using the handle 148 so that the number of turns of the spring 100 increases, the outer diameter of the spring 100 decreases from D1, and therefore the middle portion 102-3 and the first portion 102-1 of the spring 100 can be gradually inserted into a structure such as the tube 130 as the spring 100 moves in the z direction. Thereafter, the torque applied to the spring 100 is released. This causes a restoring force to act on the spring 100, which tends to return it to its original state, and the outer diameter increases, which prevents the spring 100 from falling off the structure and enables the retention of a solid body provided in the structure.

[0038] As described above, the first hook 104 of the spring 100 is provided so as not to overlap with the central axis of the coil portion 102 in the z-direction, so that even when the jig 140 is used, the first hook 104 does not interfere with the shaft 142. Therefore, when the spring 100 is attached to the jig 140, the second hook 106 can be easily and reliably fixed to the engagement portion 142a without being interfered with by the first hook 104. In addition, the engagement portion 150a that engages with the first hook 104 rotates around the extension direction of the shaft 122 while gripping the spring 100 as the base 126 rotates, so that a torque can be easily applied to the spring 100 to increase the number of turns and reduce the outer diameter. Furthermore, since there is no interference between the shaft 142 and the first hook 104, the outer diameter of the shaft 142 can be set large within the range of the minimum inner diameter of the spring 100 (the inner diameter of the second portion 102-2), so that the jig 140 is given high rigidity and can apply a large torque to the spring 100. In particular, since the jig 140 can be made lighter by making the rotor 146 the part to which force is applied when applying torque to the spring 100, high operability is achieved even when a large spring 100 is used. As a result, the spring 100 can be easily inserted and fixed into a structure such as a tube 130 having an inner diameter D4 smaller than the outer diameter D1 in the natural state.

[0039] The above-described embodiments of the present invention may be combined as appropriate as long as they are not mutually inconsistent. Furthermore, those in which a person skilled in the art appropriately adds or deletes components or modifies the design based on each embodiment are also included in the scope of the present invention as long as they include the gist of the present invention.

[0040] Furthermore, even if there are other effects and advantages different from those brought about by the respective embodiments described above, those which are clear from the description in this specification or which can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0041] 100: spring, 102: coil portion, 102-1: first portion, 102-2: second portion, 102-3: middle portion, 104: first hook, 106: second hook, 120: jig, 122: shaft, 122a: notch, 124: grip portion, 126: base, 126a: groove, 126b: engagement portion, 128: handle, 130: tube, 140: jig, 142: shaft, 142a: engagement portion, 146: rotor, 148: handle, 150: clamp bar, 150a: engagement portion

Claims

1. a first hook located at the first end; a second hook located at a second end opposite the first end; and a coil portion between the first hook and the second hook, The outer diameter of the first end side is larger than the outer diameter of the second end side, A spring, wherein the first hook is a rod that overlaps the coil portion in a direction parallel to a central axis of the coil portion, but does not overlap the central axis in said direction.

2. The spring of claim 1 , wherein the extension direction of the rod does not intersect the central axis in said direction.

3. The spring of claim 1 , wherein the second hook is a rod that overlaps with the coil portion in the direction and overlaps with the central axis in the direction.

4. the coil portion has a first portion on the first end side, a second portion on the second end side, and an intermediate portion between the first portion and the second portion, 2. The spring of claim 1, wherein an outer diameter of said first portion and said second portion is constant and an outer diameter of said intermediate portion decreases with increasing distance from said first portion.

5. A method of inserting a spring into a tube, The spring is a first hook located at the first end; a second hook located at a second end opposite the first end; and a coil portion between the first hook and the second hook, The method comprises: disposing the second end within the tube; and and moving the spring into the tube while rotating the first hook about a central axis of the coil portion to increase the number of turns of the spring while keeping the second end fixed; The outer diameter of the first end side is larger than the outer diameter of the second end side and the inner diameter of the tube, The method of claim 1, wherein the first hook is a rod that overlaps the coil portion in a direction parallel to a central axis of the coil portion, but does not overlap the central axis in said direction.

6. The method of claim 5 , wherein the extension direction of the rod does not intersect the central axis in said direction.

7. The method of claim 5 , wherein the second hook is a rod that overlaps the coil portion in the direction and overlaps the central axis in the direction.

8. the coil portion has a first portion on the first end side, a second portion on the second end side, and an intermediate portion between the first portion and the second portion, 6. The method of claim 5, wherein the outer diameter of the first portion and the second portion is constant and the outer diameter of the intermediate portion decreases with increasing distance from the first portion.

9. This is a tool for inserting springs into tubes. a shaft having a slit at a first end and a grip portion at a second end; A jig comprising a base having a through hole in the center through which the shaft can pass and having a linear groove that does not intersect with the through hole.

10. The fixture of claim 9 , further comprising a handle attached to the base for rotating the base about the shaft.

11. The spring is a first hook located at the first end; a second hook located at a second end opposite the first end; and a coil portion between the first hook and the second hook, the first hook is a rod that overlaps with the coil portion in a direction parallel to a central axis of the coil portion, and does not overlap with the central axis in the direction; The fixture of claim 9 , wherein the groove is configured to receive the first hook.

12. The jig of claim 11 , wherein the extension direction of the rod does not intersect the central axis in said direction.

13. The jig according to claim 11 , wherein an outer diameter of the first end is greater than an outer diameter of the second end and an inner diameter of the tube.

14. the second hook is a rod that overlaps with the coil portion in the direction and overlaps with the central axis in the direction; The fixture of claim 11 , wherein the slit is configured to receive the second hook.

15. the coil portion has a first portion on the first end side, a second portion on the second end side, and an intermediate portion between the first portion and the second portion, The fixture of claim 11 , wherein an outer diameter of the first portion and the second portion is constant, and an outer diameter of the intermediate portion decreases with increasing distance from the first portion.

16. This is a tool for inserting springs into tubes. a shaft having a first engagement portion at one end thereof for receiving the second end of the spring; a rotor having a through hole through which the shaft can pass; and a clamp bar attached to the rotor and extending from the rotor toward the first engagement portion; The clamp bar has a second engagement portion at a tip thereof that receives a first end of the spring opposite the second end.

17. The fixture of claim 16 , further comprising a handle attached to the rotor for rotating the rotor about the shaft.

18. The spring is a first hook located at the first end; a second hook located at the second end; and a coil portion between the first hook and the second hook, The jig of claim 16 , wherein the first hook is a rod that overlaps the coil portion in a direction parallel to a central axis of the coil portion, but does not overlap the central axis in said direction.

19. The jig of claim 18 , wherein the extension direction of the rod does not intersect the central axis in said direction.

20. The jig according to claim 18 , wherein an outer diameter of the first end is greater than an outer diameter of the second end and an inner diameter of the tube.

21. The jig of claim 18 , wherein the second hook is a rod that overlaps with the coil portion in the direction and overlaps with the central axis in the direction.

22. the coil portion has a first portion on the first end side, a second portion on the second end side, and an intermediate portion between the first portion and the second portion, 20. The fixture of claim 18, wherein an outer diameter of the first portion and the second portion is constant and an outer diameter of the intermediate portion decreases with increasing distance from the first portion.

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