JP2020133840A - Mounting structure of tension coil spring - Google Patents

Abstract

To provide a mounting structure of a tension coil spring, which can inhibit breakage of hook portions of the tension coil spring.SOLUTION: A coil spring 51 is attached in a tension state with a hook portion 53 connected to a shaft portion 45 of a link 33 and with a hook portion 54 connected to a connecting portion 42a of a link receiving portion 42. The link 33 can be displaced relatively to the link receiving portion 42 in a direction intersecting each of the tension direction of a spring body portion 52 and the extension direction of the shaft portion 45, and the coil spring 51 is displaced while maintaining the tension state with the relative displacement. An annular member 61 includes a first hook portion 63 hooked on the shaft portion 45 and a second hook portion 64 on which the hook portion 53 is hooked. When the coil spring 51 is displaced, the second hook portion 64 is pulled by the pulling force of the coil spring 51, so that the first hook portion 63 is rotated along the shaft portion 45 in a manner that the second hook portion 64 is lined up with the first hook portion 63 across the shaft portion 45 in the pulling direction.SELECTED DRAWING: Figure 5

Description

The present invention relates to a mounting structure for a tension coil spring.

Conventionally, tension coil springs have been used in various devices (see, for example, Patent Document 1). 7 and 8 show an example in which a tension coil spring is attached to a walking vehicle that assists the elderly or the like in walking. Hereinafter, the mounting structure of the tension coil spring will be described with reference to FIGS. 7 and 8. The walking vehicle is provided with a foldable leg body, and FIGS. 7 and 8 are side views showing an upper portion of the leg body portion in the walking vehicle. Further, FIG. 7 shows an open leg state (deployed state) of the leg body portion, and FIG. 8 shows a closed leg state (folded state) of the leg body portion.

As shown in FIGS. 7 and 8, the walking vehicle 80 includes a pair of left and right leg portions 81, and each of these leg portions 81 has a front leg frame 82 and a rear leg frame 83. Each leg body 81 has an open leg state in which the front leg frame 82 and the rear leg frame 83 are separated from each other (state shown in FIG. 7) and a closed leg state in which the front leg frame 82 and the rear leg frame 83 are close to each other (FIG. 8). It is possible to shift to the state shown in).

The leg body portion 81 is provided with a link portion 85 connected to the front leg frame 82 and the rear leg frame 83, respectively. In the link portion 85, a pair of links 86 and 87 are rotatably connected via a shaft portion 88, and of the links 86 and 87, the link 86 is rotatably connected to the front leg frame 82 to link. 87 is rotatably connected to the rear leg frame 83. The link portion 85 is deformed in conjunction with the opening and closing of the leg body portion 81, and when the leg body portion 81 is in the open leg state, the links 86 and 87 are in the deployed state (see FIG. 7). When the leg body portion 81 is closed, the links 86 and 87 are bent upward (see FIG. 8).

A tension coil spring 91 is attached to the link portion 85. The tension coil spring 91 has a spring body 92 formed to be expandable and contractible by winding the wire in a coil shape, and a first spring body 92 formed on both ends of the spring body 92 by forming both ends of the wire into an arc shape. It has a hook portion 93 and a second hook portion 94. In the tension coil spring 91, the first hook portion 93 is hooked on the shaft portion 86a provided on the link 86 of the link portion 85, and the second hook portion 94 is hooked on the connecting portion 95a of the bracket 95 fixed to the rear leg frame 83. It is attached by being hooked. In this mounted state, the tension coil spring 91 is in a tension state in which the spring main body 92 is pulled.

In the above configuration, the link 86 is displaced relative to the bracket 95 as the leg portion 81 opens and closes, in other words, as the link portion 85 deforms. In this case, the link 86 is displaced relative to the bracket 95 in a direction intersecting each of the extending direction of the shaft portion 86a and the pulling direction of the tension coil spring 91. Therefore, the tension coil spring 91 connected to the link 86 and the bracket 95 is displaced in the tension state due to the relative displacement. As a result, in the closed leg state of the leg portion 81, the link 86 is pulled toward the bracket 95 by the tensile force of the tension coil spring 91, and as a result, the bent state of the link portion 86 is maintained, and thus the leg body The closed leg state of the portion 81 is maintained.

JP-A-2010-106967

By the way, in the above-mentioned mounting structure of the tension coil spring 91, when the tension coil spring 91 is displaced due to the relative displacement of the link 86 with respect to the bracket 95, the tension coil spring 91 is hooked on the shaft portion 86a of the link 86. The portion 93 is displaced while rotating along the outer peripheral surface of the shaft portion 86a. Here, when the first hook portion 93 rotates around the shaft portion 86a, it is assumed that a sliding resistance is generated between the first hook portion 93 and the shaft portion 86a. In this case, since the first hook portion 93 is pressed against the outer peripheral surface of the shaft portion 86a by the tensile force of the tension coil spring 91, it is relatively between the first hook portion 93 and the shaft portion 86a. It is expected that a large sliding resistance will occur. Therefore, when the tension coil spring 91 is displaced, the first hook portion 93 rotates around the shaft portion 86a while resisting the sliding resistance, and therefore, a specific portion of the first hook portion 93 (for example, the first hook). There is a concern that stress concentration will occur at the base end portion of the arc portion in the portion 93 and the first hook portion 93 will break.

It should be noted that such a problem of breakage of the hook portion does not necessarily occur only when the tension coil spring is attached to the walking vehicle, but also occurs when the tension coil spring is attached to a device other than the walking vehicle. It's a problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mounting structure for a tension coil spring capable of suppressing breakage of a hook portion of the tension coil spring.

In order to solve the above problems, the mounting structure of the tension coil spring of the first invention has a spring body portion formed to be expandable and contractible by winding the wire rod in a coil shape, and both ends of the wire rod have an arc shape. A tension coil spring having a first hook portion and a second hook portion formed on both ends of the spring body portion, a first member having a first connecting portion to which the first hook portion is connected, and the above. The tension coil spring includes a second member having a second connecting portion to which the second hook portion is connected, the first hook portion is connected to the first connecting portion, and the second hook portion is the first. By being connected to the two connecting portions, the spring main body portion is attached in a tensioned state pulled to the extending side, and the first member is pulled by the spring main body portion with respect to the second member. The tension coil spring mounting structure is such that the tension coil spring can be relatively displaced in a direction intersecting the tension direction, and the tension coil spring is displaced while maintaining the tension state in accordance with the relative displacement. The first connecting portion includes a shaft portion extending in a direction intersecting each of the displacement direction in which the first member is relatively displaced and the tension direction of the spring body portion, and the first hook portion is attached to the shaft portion. As a configuration for connecting, a first hooking portion that is hooked on the shaft portion and is rotatable along the outer peripheral surface of the shaft portion in the hooked state is provided integrally with the first hooking portion. A second hook portion is provided on the opposite side of the shaft portion from the first hook portion and the first hook portion is hooked, and the relative displacement of the first member is provided. At the time of the accompanying displacement of the tension coil spring, the second hook portion is pulled by the tensile force of the tension coil spring, so that the second hook portion pulls the first hook portion and the shaft portion in the tension direction. The first hook portion is rotated along the shaft portion so as to be sandwiched and lined up.

According to the present invention, in the tension coil spring, the first hook portion is connected to the first connection portion of the first member, and the second hook portion is the second member of the second member in a state where the spring main body portion is pulled. It is connected to the connection part. The first member can be displaced relative to the second member, and the tension coil spring is displaced while maintaining the tension state due to the relative displacement.

The first connecting portion is a shaft portion extending in a direction intersecting the relative displacement displacement direction of the first member and the tensile direction of the tension coil spring. As a configuration for connecting the first hook portion to the shaft portion, a first hook portion and a second hook portion integrated with each other are provided, and the first hook portion is hooked on the shaft portion and is hooked on the second hook portion. The first hook part is hooked.

When the tension coil spring is displaced due to the relative displacement of the first member, the tension coil spring pulls the second hook portion so that the second hook portion is aligned with the first hook portion across the shaft portion in the tension direction. Located in. At this time, the second hooking portion is positioned as described above while the first hooking portion rotates along the shaft portion. In such a configuration, the first hook portion rotates along the shaft portion, so that the second hook portion and the tension coil spring in which the first hook portion is hooked on the second hook portion are semi-integrated. Therefore, it will rotate around the shaft portion. In this case, since it is possible to suppress the occurrence of sliding resistance between the second hook portion and the first hook portion, it is possible to suppress the occurrence of stress concentration due to the sliding resistance in the first hook portion. Can be done. As a result, it is possible to suppress breakage of the hook portion due to stress concentration.

In the first invention, the attachment structure of the tension coil spring of the second invention includes a hole through which the shaft portion is inserted, and includes an annular member that surrounds the hole, and the inside of the annular member. The peripheral side is characterized in that the first hooking portion and the second hooking portion are formed at positions opposite to each other with the hole portion interposed therebetween.

According to the present invention, the first hook portion and the second hook portion can be easily formed by using the annular member.

In the second invention, the attachment structure of the tension coil spring of the third invention is such that the shaft portion is provided on the shaft body on which the first hook portion is hooked and on the tip end side of the shaft body, and is more than the shaft body. The annular member has a head having an enlarged diameter, and the annular member has connecting portions connecting the first hooking portion and the second hooking portion on both sides of the hole portion, and each connecting portion thereof. Each of the portions includes an opposing region in which the radius of curvature of the inner peripheral portion is larger than the radius of the head portion and faces each other with the hole portion interposed therebetween, and in the first hooking portion, the inner peripheral portion thereof is included. The radius of curvature of the portion is larger than the radius of the shaft body and smaller than the radius of the head.

According to the present invention, a head for preventing slipping is provided on the tip end side of the shaft portion. In such a configuration, in the annular member, the radius of curvature of the inner peripheral portion of each connecting portion connecting the first hook portion and the second hook portion on both sides of the hole portion is larger than the radius of the head. An enlarged facing area is included. In this case, the space between the facing regions in the hole is an insertion region through which the head can be inserted. Therefore, the annular member can be attached to the shaft portion while passing the shaft portion through the insertion region. Therefore, in this case, the annular member can be easily attached to the shaft portion with the head.

On the other hand, in the first hook portion, the radius of curvature of the inner peripheral portion thereof is larger than the radius of the shaft body and smaller than the radius of the head. In this case, when the first hook portion rotates along the outer peripheral surface of the shaft portion (shaft body), it is possible to prevent the first hook portion from being displaced with respect to the shaft body in a direction different from the rotation direction. be able to. Therefore, it is easy to keep the state where the first hook portion and the second hook portion are aligned in the tensile direction of the tension coil spring, and as a result, a sliding resistance is generated between the second hook portion and the first hook portion. Can be suitably suppressed. Therefore, in this case, it is possible to preferably suppress the breakage of the hook portion due to the sliding resistance while facilitating the attachment of the annular member to the shaft portion.

The attachment structure of the tension coil spring of the fourth invention is characterized in that, in the third invention, the radius of curvature of the inner peripheral portion of the second hook portion is smaller than that of the first hook portion. ..

According to the present invention, since the radius of curvature of the inner peripheral portion of the second hook portion is smaller than that of the first hook portion, it is possible to prevent the first hook portion hooked on the second hook portion from being displaced. be able to. As a result, when the tension coil spring is displaced, it is easy to keep the state where the first hook portion and the second hook portion are aligned in the tension direction of the tension coil spring, and as a result, the second hook portion and the first hook portion are separated from each other. It is possible to preferably suppress the generation of sliding resistance between them. Therefore, in this case, breakage of the hook portion due to sliding resistance can be suitably suppressed.

A perspective view of a walking vehicle with the legs open, as viewed diagonally from the front. A perspective view of a walking vehicle with its legs closed, as viewed diagonally from the front. The side view which shows the structure around the interlocking mechanism in the open leg state of a leg body part enlarged. The side view which shows the structure around the interlocking mechanism in a closed state of a leg body part enlarged. The side view which shows the mounting structure of a coil spring. Front view of the annular member. It is a side view which shows an example of the attachment structure which attached the tension coil spring to a pedestrian vehicle, and shows the open leg state of a leg body part. It is a side view which shows an example of the attachment structure which attached the tension coil spring to a pedestrian vehicle, and shows the closed state of the leg body part.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. 1 and 2 are perspective views of the walking vehicle 10 as viewed diagonally from the front. FIG. 1 shows a state in which the leg body portion 11 of the walking vehicle 10 is open, and FIG. 2 shows a state in which the legs are closed. Further, in the following description, the moving direction when moving the walking vehicle 10 is the front-rear direction, and the direction orthogonal to the front-rear direction is the left-right direction.

As shown in FIG. 1, the walking vehicle 10 includes a pair of leg bodies 11 provided apart from each other in the left-right direction, a seat portion 12 provided between the leg bodies 11, and each leg body portion 11. A backrest component 13 for forming the backrest 14 is provided.

Each leg body 11 has a front leg frame 15 and a rear leg frame 16 extending vertically. Each of these leg frames 15 and 16 is made of a light metal such as aluminum. A front wheel 17 is attached to the lower end of the front leg frame 15, and a rear wheel 18 is attached to the lower end of the rear leg frame 16.

The front leg frame 15 and the rear leg frame 16 are rotatably connected to each other via a rotation shaft 22 extending in the left-right direction at the upper end portion of each other. As a result, the front leg frame 15 and the rear leg frame 16 are rotatable about the rotation shaft 22. Then, due to the rotation, the leg body portion 11 has an open leg state in which the lower portions of the leg frames 15 and 16 are separated from each other (state shown in FIG. 1) and a closed leg in which the lower portions of the leg frames 15 and 16 approach each other. It is possible to shift to the state (state shown in FIG. 2). Further, in the closed leg state, the lower parts of the leg frames 15 and 16 approach each other, so that the leg body portion 11 is in a folded state. In this folded state, the walking vehicle 10 can stand on its own.

The hind leg frame 16 has a tubular shape, and the strut frame 23 is inserted into the rear leg frame 16 from above. The position of the support column 23 can be adjusted in the vertical direction when the support frame 23 is inserted into the rear leg frame 16. Then, the support column frame 23 is fixed to the rear leg frame 16 at the position adjusted position by using the screw member 24. Further, the handle 26 and the brake lever 27 are attached to the upper end portion of the support column frame 23 via the attachment portion 25. The height position (handle height) of the handle 26 can be adjusted by adjusting the vertical position of the support frame 23.

The seat portion 12 is made of a resin seat material, and is attached to two seat portion frames 28 and 29 provided apart from each other in the front-rear direction. The seat frames 28 and 29 are made of a pipe material extending in the left-right direction. Both ends of the front seat frame 28 are fixed to the front leg frame 15 of each leg body 11, and both ends of the rear seat frame 29 are fixed to the rear leg frame 16 of each leg body portion 11. Has been done.

The backrest component 13 is connected to the upper end of each leg portion 11 and is formed in an arch shape (substantially U-shaped) that is convex toward the front. The front end of the backrest component 13 is used as the backrest 14.

The backrest component 13 is rotatably connected to each leg 11 via a rotation shaft 22. The backrest component 13 is located between a backrest position (see FIG. 1) that forms the backrest 14 by rotation around each rotation shaft 22 and a retracted position (see FIG. 2) that is retracted upward from the backrest position. It is said that it can be moved at. Further, the backrest component 13 is provided with a handle member 13a that grips the backrest component 13 when the backrest component 13 is rotated.

The walking vehicle 10 is provided with an interlocking mechanism 30 that switches the leg body portion 11 between the open leg state and the closed leg state in conjunction with the rotation of the backrest component portion 13. The interlocking mechanism 30 is provided for each leg body portion 11, and connects the leg body portion 11 and the backrest component portion 13, respectively. By this interlocking mechanism 30, when the backrest component 13 is in the backrest position, the leg body 11 is in the open leg state, and when the backrest component 13 is in the retracted position, the leg body 11 is in the closed leg state. As such, both 11 and 13 are interlocked with each other.

Subsequently, the configuration of the interlocking mechanism 30 will be described in detail with reference to FIGS. 3 and 4. 3 and 4 are side views showing an enlarged configuration around the interlocking mechanism 30. FIG. 3 shows the open leg state of the leg body portion 11, and FIG. 4 shows the closed leg state.

As shown in FIGS. 3 and 4, the interlocking mechanism 30 has a link portion 31 that connects the front leg frame 15 and the rear leg frame 16 of the leg body portion 11, and a link that connects the link portion 31 and the backrest component portion 13. It has a connecting portion 32. The link portion 31 has a pair of metal links 33, 34 that are arranged below the backrest constituent portion 13 and extend linearly, and a shaft portion 35 that connects the ends of the links 33, 34 to each other. ing. The shaft portion 35 extends in the left-right direction, and the links 33 and 34 are rotatable about the shaft portion 35.

Of the pair of links 33 and 34, one link 33 is rotatably connected to the front leg frame 15 via the shaft portion 37, and the other link 34 is rotatably connected to the rear leg frame 16 via the shaft portion 38. Is connected to. Both of these shaft portions 37 and 38 extend in the left-right direction like the shaft portion 35. Specifically, a link receiving portion 41 is fixed to the front leg frame 15, and an end portion of the link 33 on the opposite axis portion 35 side is connected to the link receiving portion 41 via a shaft portion 37. Further, a link receiving portion 42 is fixed to the rear leg frame 16, and an end portion of the link 34 on the opposite axis portion 35 side is connected to the link receiving portion 42 via a shaft portion 38.

In the link portion 31, each of the links 33 and 34 rotates with respect to the shaft portion 35. The link portion 31 is in an unfolded state (see FIG. 3) in which the links 33 and 34 are expanded so as to extend back and forth by rotation of the links 33 and 34, and the links 33 and 34 project upward. It is said that it can be deformed into a bent state (see FIG. 4). In this case, when the link portion 31 is in the expanded state, the leg body portion 11 is in the open leg state, and when the link portion 31 is in the bent state, the leg body portion 11 is in the closed leg state accordingly. It has become like.

The link 33 is provided with a shaft portion 45 that comes into contact with the link 34 when the link portion 31 is in the deployed state (see FIG. 3). The shaft portion 45 is formed of a columnar pin extending in the left-right direction, and is provided at a boundary portion with the link 34 at the link 33. In this case, when the contacted portion 34a provided on the link 34 comes into contact with the shaft portion 45, it is regulated that the links 33 and 34 are bent so as to project downward. Then, by this regulation, it is regulated that the leg body portion 11 moves from the open leg state to the further open leg side.

When the link portion 31 is in the bent state, the contacted portion 34b provided on the link 34 comes into contact with the shaft portion 45. In this case, the contact is restricted from further bending of the links 33 and 34. Then, by this regulation, it is regulated that the leg body portion 11 further moves from the closed leg state to the closed leg side. As a result, the leg body portion 11 can operate only in the range from the open leg state to the closed leg state.

The link connecting portion 32 is made of a long material extending in a straight line, and connects the link portion 31 and the backrest constituent portion 13 in the vertical direction. The link connecting portion 32 is rotatably connected to the link portion 31 and the backrest forming portion 13, respectively. With the link connecting portion 32, when the backrest constituent portion 13 is in the backrest position, the link portion 31 is in the expanded state, and when the backrest constituent portion 13 is in the retracted position, the link portion 31 is in the bent state. As such, the backrest constituent portion 13 and the link portion 31 are interlocked with each other.

The link connecting portion 32 has a rod-shaped main body portion 32a and a pair of connecting portions 32b and 32c fixed to both ends of the main body portion 32a. The main body 32a is made of a metal rod, and the connecting parts 32b and 32c are made of a metal plate. In the link connecting portion 32, one connecting portion 32b is rotatably connected to the backrest component 13 via the shaft portion 46, and the other connecting portion 32c is rotatably connected to the link portion 31 via the shaft portion 35. It is connected. The shaft portion 46 is a shaft extending in the left-right direction, and is arranged in front of the rotation shaft 22 of the backrest constituent portion 13.

Subsequently, the action when each leg body portion 11 is switched between the open leg state and the closed leg state in conjunction with the rotation operation of the backrest constituent portion 13 by the interlocking mechanism 30 described above will be described.

As shown in FIG. 3, when the backrest constituent portion 13 is in the backrest position, the leg body portion 11 is in the open leg state. When the backrest constituent portion 13 is rotated upward from the backrest position toward the retracted position, the link portion 31 is pulled upward by the backrest constituent portion 13 via the link connecting portion 32. Then, the link portion 31 is deformed so that the links 33 and 34 are bent upward, and the front leg frame 15 and the rear leg frame 16 approach each other with the deformation of the link portion 31. Then, when the backrest component 13 is rotated to the retracted position, as shown in FIG. 4, the front leg frame 15 and the rear leg frame 16 are folded into each other, and the leg body portion 11 is closed.

Contrary to the above case, when the backrest component 13 is rotated downward from the retracted position to the backrest position, the link portion 31 is pushed down by the backrest component 13 via the link connecting portion 32. Be done. Then, the link portion 31 is expanded accordingly, and the front leg frame 15 and the rear leg frame 16 are separated from each other as the link portion 31 is expanded. Then, when the backrest constituent portion 13 is rotated to the backrest position, the leg body portion 11 is brought into the open leg state.

Here, the walking vehicle 10 is provided with a coil spring 51 as a member for holding the closed leg state of the leg body portion 11. Hereinafter, the mounting structure of the coil spring 51 will be described with reference to FIG. 5 in addition to FIGS. 3 and 4. Note that FIG. 5 is a side view showing the mounting structure of the coil spring 51.

As shown in FIGS. 3 to 5, the coil spring 51 is composed of a tension coil spring. The coil spring 51 is formed at both ends of a spring body 52 formed by winding a metal wire 51a into a coil shape and by forming both ends of the wire 51a into an arc shape. It has a pair of hook portions 53 and 54. Each of the hook portions 53 and 54 is a round hook, and is arranged so as to be offset by 90 ° in the axial direction of the coil spring 51. The hook portion 53 corresponds to the first hook portion, and the hook portion 54 corresponds to the second hook portion.

The coil spring 51 is provided for each leg body portion 11. The coil spring 51 is attached by connecting the hook portion 53 to the shaft portion 45 provided on the link 33 of the link portion 31 and connecting the hook portion 54 to the connecting portion 42a provided on the link receiving portion 42. There is. In this case, the coil spring 51 is attached in a tension state in which the spring main body 52 is pulled (extended) from its natural length. In the mounted state of the coil spring 51, the pulling direction in which the coil spring 51 is pulled is set to intersect the extending direction of the shaft portion 45 (that is, the left-right direction), and more specifically, the direction is orthogonal to the extending direction of the shaft portion 45. ing.

Here, as described above, when the leg body portion 11 is switched between the open leg state and the closed leg state, the link portion 31 is deformed into the unfolded state and the bent state in conjunction with the switching. When the link portion 31 is deformed, the link 33 of the link portion 31 is displaced relative to the link receiving portion 42 (and thus the rear leg frame 16). In this case, the displacement direction in which the link 33 is displaced relative to the link receiving portion 42 (hereinafter, abbreviated as the displacement direction of the link 33) is a direction intersecting the tensile direction of the coil spring 51. Further, the displacement direction of the link 33 is a direction that intersects with the extending direction of the shaft portion 45, and more specifically, is a direction orthogonal to the extending direction of the shaft portion 45. In this case, the link 33 corresponds to the first member, and the link receiving portion 42 corresponds to the second member. Further, the shaft portion 45 corresponds to the first connecting portion, and the connecting portion 42a corresponds to the second connecting portion.

Since the link 33 is displaced relative to the link receiving portion 42, the coil spring 51 connected to the shaft portion 45 of the link 33 and the connecting portion 42a of the link receiving portion 42 is displaced according to the relative displacement. It has become so. Upon displacement of the coil spring 51, the coil spring 51 is displaced while maintaining the tension state, and more specifically, the coil spring 51 is displaced in the tension state over the entire displacement range of the displacement.

Since the coil spring 51 is in a tension state over the entire displacement range, the link 33 is connected to the link receiving portion by the tensile force of the coil spring 51 in the bent state of the link portion 31, that is, in the closed leg state of the leg body portion 11. It is in a state of being pulled to the side of 42. As a result, in the closed leg state of the leg body portion 11, the link portion 31 is suppressed from being deformed to the unfolded state side, and thus the leg body portion 11 is suppressed from being switched to the open leg state. As a result, the link portion 31 is held in the bent state, and the leg body portion 11 is held in the closed state.

Subsequently, a connection configuration in which the hook portions 53 and 54 of the coil spring 51 are connected to the shaft portion 45 and the connection portion 42a, respectively, will be described. First, of the hook portions 53 and 54, a connection configuration in which the hook portion 54 is connected to the connection portion 42a of the link receiving portion 42 will be described.

The link receiving portion 42 is formed of a steel plate and extends vertically along the rear leg frame 16. The link receiving portion 42 has a protruding piece 42b that protrudes forward from the intermediate portion in the vertical direction thereof. The tip side of the protruding piece 42b is bent outward in the left-right direction, and the bent portion forms a connecting portion 42a. The connecting portion 42a is formed with a hole portion 56 penetrating in the front-rear direction. The hook portion 54 of the coil spring 51 is inserted through the hole portion 56, and the hook portion 54 is hooked on the connecting portion 42a in the inserted state.

Subsequently, the configuration of the connecting portion in which the hook portion 53 is connected to the shaft portion 45 will be described.

As described above, the shaft portion 45 has a columnar shape extending in the left-right direction. The shaft portion 45 has a shaft main body 45a whose base end portion is fixed to the link 33, and a head portion 45b provided at the tip end portion of the shaft main body 45a. The outer diameter of the head 45b is larger than the outer diameter of the shaft body 45a.

An annular member 61 formed in an annular shape is attached to the shaft portion 45. The annular member 61 is formed of a metal flat plate and is formed in a substantially annular shape. The annular member 61 has a hole 62 inside the annular member 61, and is attached to the shaft 45 with the shaft 45 inserted through the hole 62.

FIG. 6 shows a front view of the annular member 61. Hereinafter, the configuration of the annular member 61 will be described with reference to FIGS. 6 and 6 in addition to FIGS. 3 to 5.

As shown in FIGS. 3 to 6, the annular member 61 has a first hook portion 63 hooked on the shaft portion 45 and a second hook portion 64 on which the hook portion 53 of the coil spring 51 is hooked on the inner peripheral side thereof. have. The first hook portion 63 and the second hook portion 64 are formed on opposite sides of the hole 62.

The first hook portion 63 and the second hook portion 64 each have an arc shape in which the inner peripheral portions thereof are convex on opposite sides. The radius of curvature r1 of the inner peripheral portion of the first hook portion 63 is made larger than the radius of the shaft body 45a of the shaft portion 45 and smaller than the radius of the head portion 45b of the shaft portion 45. Specifically, the radius of curvature r1 of the inner peripheral portion of the first hook portion 63 is slightly larger than the radius of the shaft body 45a. Further, the radius of curvature r2 of the inner peripheral portion of the second hook portion 64 is smaller than the radius of curvature r1 of the inner peripheral portion of the first hook portion 63. Specifically, the radius of curvature r2 of the inner peripheral portion of the second hook portion 64 is set to be half or less of the radius of curvature r1 of the first hook portion 63.

The annular member 61 has connecting portions 66 connecting the first hooking portion 63 and the second hooking portion 64 on both sides of the hole 62. Each connecting portion 66 has a first portion 67 continuous with the first hook portion 63 and a second portion 68 continuous with the second hook portion 64. The first portion 67 of each connecting portion 66 faces each other with the hole 62 interposed therebetween, and the second portion 68 of each connecting portion 66 faces each other with the hole 62 interposed therebetween. Each first portion 67 corresponds to an opposite region.

In each first portion 67, the inner peripheral portion thereof has an arc shape, and more specifically, each inner peripheral portion has an arc shape which is convex on the opposite side to each other. In each first portion 67, the radius of curvature r3 of the inner peripheral portion thereof is made larger than the radius of the head portion 45b of the shaft portion 45. As a result, the region between the first portions 67 in the hole 62 is an insertion region 62a through which the head 45b can be inserted. In FIG. 6, the head 45b is shown by a chain double-dashed line for reference.

In each second portion 68, the inner peripheral portion thereof is linear. In each second portion 68, the inner peripheral portion connects the inner peripheral portion of the first portion 67 and the inner peripheral portion of the second hook portion 64, and is inclined so as to approach each other toward the second hook portion 64 side. ing.

As shown in FIG. 5, the annular member 61 has its first hook portion 63 hooked on the shaft body 45a of the shaft portion 45, and the hook portion 53 of the coil spring 51 is hooked on the second hook portion 64. As a result, the hook portion 53 is connected to the shaft portion 45 via the annular member 61. In this case, in the annular member 61, the first hook portion 63 and the second hook portion 64 are arranged on opposite sides of the shaft portion 45. Specifically, the second hook portion 64 is pulled by the tensile force of the coil spring 51, so that the second hook portion 64 and the first hook portion 63 are arranged side by side in the tensile direction of the coil spring 51 with the shaft portion 45 interposed therebetween. Has been done.

As described above, when the link 33 of the link portion 31 is displaced relative to the link receiving portion 42 as the leg body portion 11 shifts to the open leg state and the closed leg state, the coil spring is associated therewith. 51 is displaced. When the coil spring 51 is displaced, the tensile force of the coil spring 51 pulls the second hook portion 64 of the annular member 61, so that the second hook portion 64 sandwiches the shaft portion 45 in the pulling direction. It is located so as to be aligned with the first hook portion 63 (see FIGS. 3 to 5). In this case, the second hook portion 64 is positioned as described above while the first hook portion 63 rotates along the outer peripheral surface of the shaft portion 45.

In such a configuration, the first hook portion 63 rotates along the shaft portion 45, so that the second hook portion 64 and the coil spring 51 in which the hook portion 53 is hooked on the second hook portion 64 are in the middle. Together, it rotates around the shaft portion 45. In this case, since it is possible to suppress the occurrence of sliding resistance between the second hook portion 64 and the hook portion 53, it is possible to suppress the occurrence of stress concentration due to the sliding resistance in the hook portion 53. it can. As a result, breakage of the hook portion 53 due to stress concentration can be suppressed.

Since the annular member 61 is formed to have a strength sufficiently higher than that of the wire rod 51a of the coil spring 51, the first hook portion 63 has the above-described configuration in which the first hook portion 63 rotates along the shaft portion 45. However, damage is prevented.

According to the configuration of the present embodiment described in detail above, the following excellent effects can be obtained.

The first hooking portion 63 and the second hooking portion 64 are provided on the inner peripheral side of the annular member 61 at positions opposite to each other with the hole portion 62 interposed therebetween. In this case, the first hook portion 63 and the second hook portion 64 can be easily formed by using the annular member 61.

In the annular member 61, the radius of curvature r3 of the inner peripheral portion is the radius of the head 45b of the shaft portion 45 at each connecting portion 66 connecting the first hook portion 63 and the second hook portion 64 on both sides of the hole 62. The first part 67, which is larger than the above, is included. In this case, the insertion region 62a through which the head 45b can be inserted is set between the first portions 67 in the hole portion 62. Therefore, the annular member 61 can be attached to the shaft portion 45 while passing the shaft portion 45 through the insertion region 62a. Therefore, in this case, the annular member 61 can be easily attached to the shaft portion 45 with the head portion 45b.

On the other hand, in the first hook portion 63, the radius of curvature r1 of the inner peripheral portion thereof is made larger than the radius of the shaft body 45a of the shaft portion 45 and smaller than the radius of the head portion 45b. In this case, when the first hook portion 63 rotates along the outer peripheral surface of the shaft portion 45 (shaft body 45a), the first hook portion 63 is displaced with respect to the shaft body 45a in a direction different from the rotation direction. Can be suppressed. Therefore, it is easy to keep the state where the first hook portion 63 and the second hook portion 64 are aligned in the tensile direction of the coil spring 51, and as a result, the sliding resistance is increased between the second hook portion 64 and the hook portion 53. It can be suitably suppressed from occurring. Therefore, in this case, it is possible to preferably suppress the breakage of the hook portion 53 due to the sliding resistance while facilitating the attachment of the annular member 61 to the shaft portion 45.

In the second hook portion 64, the radius of curvature r2 of the inner peripheral portion thereof is made smaller than the radius of curvature r1 of the inner peripheral portion of the first hook portion 63. In this case, it is possible to prevent the hook portion 53 hooked on the second hook portion 64 from being displaced. As a result, when the coil spring 51 is displaced, it is easy to keep the state in which the first hook portion 63 and the second hook portion 64 are aligned in the tensile direction of the coil spring 51, and as a result, the second hook portion 64 and the hook portion 53. It is possible to preferably suppress the occurrence of sliding resistance between the two. Therefore, in this case, the breakage of the hook portion 53 due to the sliding resistance can be suitably suppressed.

The present invention is not limited to the above embodiment, and may be implemented as follows, for example.

(1) The form of the annular member 61 is not necessarily limited to that of the above embodiment. In particular, in the above embodiment, the magnitude relation of the radius of curvature r1 to r3 of each inner peripheral portion of the first hooking portion 63, the second hooking portion 64 and the first portion 67 is r2 <r1 <r3. May be changed. For example, it is conceivable that the radius of curvature r2 of the second hooking portion 64 is the same as the radius of curvature r1 of the first hooking portion 63. Further, the annular member 61 (hole portion 62) may have a perfect circular shape, and the radii of curvature r1 to r3 of the respective portions 63, 64, 66 may have the same size. Further, the inner peripheral portions of the first hook portion 63 and the second hook portion 64 do not necessarily have to have an arc shape, and may have other shapes such as a V shape and a U shape.

(2) In the above embodiment, the first hook portion 63 and the second hook portion 64 are formed by using the annular member 61, but the hook members forming these hook portions 63 and 64 do not necessarily have to be annular. Absent. For example, it is conceivable to form a C-shaped member by removing one of the connecting portions 66 of the annular member 61, and to use the C-shaped member as a hooking member. Further, the hooking member may be formed by using a plate-shaped member or a linear member bent in an S shape. In this case, the pair of hook portions (bent portions) of the S-shaped member are the hook portions 63 and 64, respectively.

(3) For example, in the configuration of the above embodiment, in addition to the connection portion (first connection portion) to which the hook portion 53 of the coil spring 51 is connected, the connection portion (second connection portion) to which the hook portion 54 is connected. Is also considered to be formed by the shaft portion. Therefore, in such a case, when connecting the hook portion 54 to the shaft portion, the connection configuration of the present invention using the annular member 61 may be adopted. In this case, the first hook portion 63 of the annular member 61 is hooked on the shaft portion, and the hook portion 54 is hooked on the second hook portion 64.

Further, in the configuration of the above embodiment, of the two connection portions (first connection portion and second connection portion) to which the hook portions 53 and 54 are connected, only the connection portion to which the hook portion 54 is connected is formed by the shaft portion. It is also possible that it will be done. Therefore, in such a case, the connection configuration of the present invention using the annular member 61 may be adopted.

(4) In the above embodiment, when connecting the hook portion 53 made of a round hook to the shaft portion 45, the connection configuration of the present invention using the annular member 61 is adopted, but a U-shaped hook, a half-round hook, and a diaphragm round are used. The connection configuration of the present invention can also be applied when connecting another hook portion formed in an arc shape such as a hook to the shaft portion 45.

(5) In the above embodiment, the coil spring mounting structure of the present invention is applied to the coil spring 51 that holds the leg portion 11 of the walking vehicle 10 in the closed leg state, but the coil spring is not limited to the walking vehicle 10 and is not limited to the walking vehicle 10. It is conceivable that it is generally used for a mobile vehicle having an openable / closable leg body that can be switched between an open leg state and a closed leg state. Therefore, in such a case, the coil spring mounting structure of the present invention may be applied.

Further, the coil spring mounting structure of the present invention does not necessarily have to be applied to a coil spring that holds the leg closed state, and can be similarly applied to a coil spring used for other purposes. ..

10 ... Walking vehicle, 33 ... Link as the first member, 42 ... Link receiving portion as the second member, 42a ... Connecting portion as the second connecting portion, 45 ... Shaft portion as the first connecting portion, 45a ... Shaft Main body, 45b ... Head, 51 ... Coil spring as tension coil spring, 51a ... Wire rod, 52 ... Spring main body, 53 ... Hook part as first hook part, 54 ... Hook part as second hook part, 61 ... annular member, 62 ... hole portion, 63 ... first hooking portion, 64 ... second hooking portion, 66 ... connecting portion, 67 ... first portion as an opposing region.

Claims (4)

A spring body that is stretchable by winding the wire into a coil, and a first hook and a second hook that are formed on both ends of the spring body by making both ends of the wire arcuate. A tension coil spring having a part and
A first member having a first connecting portion to which the first hook portion is connected, and
A second member having a second connecting portion to which the second hook portion is connected is provided.
The tension coil spring is pulled toward the extension side of the spring main body portion by connecting the first hook portion to the first connecting portion and connecting the second hook portion to the second connecting portion. It is installed in a tensioned state,
The first member can be displaced relative to the second member in a direction intersecting the tension direction in which the spring body is pulled, and the tension coil spring maintains the tension state with the relative displacement. It is a mounting structure of a tension coil spring that is displaced as it is.
The first connecting portion includes a shaft portion extending in a direction intersecting each of the displacement direction in which the first member is relatively displaced and the tension direction of the spring body portion.
As a configuration for connecting the first hook portion to the shaft portion,
A first hook portion that is hooked on the shaft portion and is rotatable along the outer peripheral surface of the shaft portion in the hooked state, and a first hook portion.
A second hooking portion that is provided integrally with the first hooking portion, is arranged on the opposite side of the shaft portion from the first hooking portion, and is hooked by the first hook portion. Prepare,
When the tension coil spring is displaced due to the relative displacement of the first member, the second hook portion is pulled by the tensile force of the tension coil spring, so that the second hook portion is moved in the tension direction. A mounting structure for a tension coil spring, wherein the first hooking portion is rotated along the shaft portion so as to be arranged so as to sandwich the first hooking portion and the shaft portion. It has a hole through which the shaft is inserted, and includes an annular member that surrounds the hole.
The first aspect of the present invention is characterized in that the first hooking portion and the second hooking portion are formed on the inner peripheral side of the annular member at positions opposite to each other with the hole portion interposed therebetween. The mounting structure of the tension coil spring described. The shaft portion has a shaft main body on which the first hook portion is hooked, and a head portion provided on the tip end side of the shaft main body and having a diameter larger than that of the shaft main body.
The annular member has connecting portions connecting the first hooking portion and the second hooking portion on both sides of the hole portion.
Each of these connecting portions includes an opposing region in which the radius of curvature of the inner peripheral portion is made larger than the radius of the head portion and faces each other across the hole portion.
The tension coil spring according to claim 2, wherein the radius of curvature of the inner peripheral portion of the first hook portion is larger than the radius of the shaft body and smaller than the radius of the head portion. Mounting structure. The mounting structure for a tension coil spring according to claim 3, wherein the radius of curvature of the inner peripheral portion of the second hook portion is smaller than that of the first hook portion.

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