JPH0573931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a joint structure for a coil spring that can be applied, for example, to connecting garter springs.

[Conventional technology]

Conventionally, there are joint structures for connecting coil springs, such as those shown in FIGS. 3 and 4, for example. We will give an overview of these.

In FIG. 3, an example of a joint structure of a coil spring is shown. The outer diameter of the connecting portion 30 of one coil spring 31 is formed to be slightly larger than the inner diameter of the connecting portion of the other coil spring 32, and the connecting portion 30, that is, the end of one coil spring 31 is connected to the other coil spring 32. It has a joint structure that is screwed into the end of the spring 32 for connection.

In FIG. 4, another example of the joint structure of the coil spring is shown. The coil springs 41 and 42 are connected to each other via a core metal 40 of the coil spring. The outer diameter of the core metal 40 is larger than the inner diameter of the coil springs 41 and 42, and the wire diameter of the core metal 40 is the same or almost the same as the wire diameter of the coil springs 41 and 42. In this joint structure, coil springs 41 and 42 are screwed into a core metal 40 and connected.

[Problem that the invention seeks to solve]

However, in the joint structure of the coil springs shown in Figures 3 and 4, the joints in both cases have double coil windings, so the rigidity of the joints is high and they are repeatedly subjected to bending loads. Furthermore, since the other coil spring or the coil spring of the core metal is simply screwed into the recess between the strands of the coil spring, there is a problem that the connection easily comes off when subjected to strong tensile force. be. In particular, in the case of garter springs used as springs for holding oil seal lips or spring belts for power transmission, considering their usage, bending loads and strength must be applied to the joints at both ends to make them endless. tensile force etc. are applied repeatedly. Therefore, it is not preferable to use the joint structure of the coil spring as shown in FIGS. 3 and 4 for the connection portion of the coil spring, and there are problems.

An object of the present invention is to solve the above-mentioned problems, and even if the coil spring is repeatedly subjected to bending loads, breakage does not occur at the connecting portion of the coil spring, and the durability against bending is improved. Coil springs that do not disconnect even when subjected to strong tensile forces, are especially suitable for use as joint structures for garter springs, and can maintain the shape and function of the joint over a long period of time. The purpose is to provide a joint structure.

[Means for solving problems]

In order to solve the above problems and achieve the above objects, the present invention is configured as follows. That is, in the present invention, the ends of the coil spring are configured with a pitch winding having a gap,
More specifically, the joint structure of a coil spring is characterized in that the connecting portions of each of the ends are screwed together in a lapped state, and a core bar is inserted into the connecting portion of the end portions. Specifically, the gap formed by the pitch winding is approximately equal to the wire diameter of the coil spring, and the core metal made of the coil spring is inserted into the end portion over a range where the end portion wraps or beyond. The wire diameter of the cored metal is approximately half the diameter of the wire at the end, the outer diameter of the cored metal is larger than the inner diameter of the end, and the coil spring of the cored metal is tightly wound. The present invention relates to a joint structure for a coil spring, characterized in that the joint structure is formed into a pitch winding having a gap having a length that is approximately the same as the diameter of the wire at the end, and is further applicable to a garter spring.

[Effect]

The joint structure of the coil spring according to the present invention constructed as described above operates as follows. The strands of the connecting portions of the coil springs to be connected are wrapped alternately to completely engage and firmly connect the ends of the coil springs to each other,
The core bar functions to prevent the wires in the connecting portion from coming out of the engaged state by wrapping alternately, thereby reinforcing the connected state of the coil spring. Further, the gap provided between the strands of the connecting portion of each of the coil springs facilitates screwing in the strands of the mating coil spring, and further,
Since the core metal is a coil spring and the diameter of the wire is smaller than the diameter of the wire at the end of the coil spring, the rigidity of the connecting portion of the coil spring is extremely small and bending load is reduced. It will not be damaged even if it is exposed to

〔Example〕

Hereinafter, embodiments of the joint structure of a coil spring according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a joint structure of a coil spring according to the present invention.
The ends of the coil springs 11 and 12 are connected to each other via the metal core 10. The average coil diameter of these coil springs 11 and 12,
The inner diameter, outer diameter, and wire diameter are approximately the same. Furthermore,
Each end or connection has a coil pitch of 1
Pitch winding is performed such that gaps 13 and 14, that is, gaps 13 and 14, are formed between the wires over a range of more than one turn. These coil springs 11,
12 are connected by screwing so that the other strand fits into the gaps 13 and 14 provided respectively, and wraps one or more turns. Therefore, as shown in FIG. There is no heavy winding structure, and the wires of the coil springs 11 and 12 alternately wrap and mesh to form a strong connection. The core metal 10 is made of a coil spring, and its outer diameter is larger than the inner diameter of the coil springs 11 and 12, and its strand diameter is approximately 1/2 of the strand diameter of the coil springs 11 and 12. There is. As shown in FIG. 1, the core metal 10 is screwed into the inside of the connecting portion of the coil springs 11, 12, so it holds the coil springs 11, 12 from the inside, and the strands at the connecting portion of the coil springs 11, 12 are held together. prevent the mesh from disengaging. Furthermore, although the coil springs 11 and 12 are screwed together so as to overlap at least one turn, the core bar 10 is formed to extend over the range of the wrapping or beyond.

FIG. 2 is a sectional view showing another embodiment of the joint structure of a coil spring according to the present invention. The coil springs 21 and 22 to be connected have the same structure as the embodiment shown in FIG. The coil springs 21 and 22 are formed over a range of one turn or more, and the wires to be connected enter the gaps 23 and 24 so as to wrap one turn or more of each other.
The wires are screwed together and the wires are wrapped alternately and interlocked to connect. The differences between this example and the example shown in FIG. 1 are as follows:
The pitch of the coil spring of the core metal 20 is set to the diameter of the strands of the coil springs 21 and 22,
Therefore, the core metal 20 is connected to the coil springs 21 and 22.
It is screwed into the recess between the wires, that is, the adjacent portion, and holds the connecting portion of the coil springs 21 and 22 from the inside. Moreover, although the coil springs 21 and 22 are screwed together so as to overlap each other by at least one turn, the core bar 20 is
It is formed to extend over the range that it wraps or beyond.

Next, the operation of the joint structure of the coil spring according to the present invention will be explained in detail. To connect the coil springs 11 and 12 or the coil springs 21 and 22 to each other, first insert the coil springs of the core metals 10 and 20 into one of the coil springs. Next, attach the other coil spring to the core metals 10 and 20.
Screw in along the outer diameter of the coil spring, and then screw in so that the ends of the coil springs overlap each other. At this time, since gaps 13, 14 and 23, 24 are formed between the coil springs, the wires at the ends of each coil spring smoothly enter, wrap and engage alternately, and are easily connected. and is strongly connected. Since the core metals 10 and 20 are held from the inside of the connection portions of these coil springs 11 and 12 and 21 and 22 so that the engagement between the wires does not come loose, even if a strong tensile force is applied, the connection portions It will never come off. In addition, the connecting portions of the coil springs 11, 12 and 21, 22 do not have a double-wound coil shape as in the conventional case.
Moreover, since the core metals 10 and 20 are coil springs, and the diameter of their wires is also made small, the coil 1
The rigidity of the connecting portions 1, 12 and 21, 22 can be made small, and in particular, the rigidity of the core bar 20 shown in FIG. This improves durability against bending. Therefore, the joint structure of this coil spring can be applied to garter springs, which are required to be resistant to breakage even when subjected to repeated bending loads, and whose connecting portions do not come off even when subjected to high-strength tensile forces. . Garter springs are springs that are used for tightening by connecting the ends of tightly wound coil springs into a ring shape, and the joint structure according to the present invention is most suitable for the connection part to make the coil springs endless. This makes it possible to maintain the shape and function of the garter spring, making it possible to use it for a long period of time.

Although the embodiments of the joint structure of the coil spring according to the present invention have been described in detail above,
It goes without saying that this invention is not limited to the details of the above-mentioned embodiments, but can be modified in various ways within the technical scope of the invention, which is limited only by the matters described in the claims. For example, although the joint structure has been described for coil springs whose wire diameters are approximately the same, it goes without saying that the present invention can be similarly applied to coil springs whose wire diameters are different. It goes without saying that the present invention can also be applied to coil springs with slightly different inner diameters, outer diameters, average coil diameters, etc.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the end of one coil spring is screwed into the end of the other coil spring, and the wires of the connecting portion of each coil spring are alternately wrapped and connected. At the same time, because a core metal is inserted inside this connection point, the strands of each coil spring are strongly engaged. However, the core metal prevents the mesh from coming loose, and even when subjected to strong tensile force, the coil springs do not The connection will never come off. Further, the pitch of the connecting portion of each coil spring is set to such an extent that a gap corresponding to the diameter of the strands of the coil spring can be created between the strands over a range of one turn or more,
Because the wires of the other coil spring fit into this gap, screwing can be done smoothly when connecting the coil springs.Furthermore, as mentioned above, the coil springs have their wires wrapped alternately. Because they are connected so that they mesh together, and the diameter of the core metal wire is made small,
The rigidity of the connecting portion of the coil spring is significantly reduced, and even if it is repeatedly subjected to bending loads, it will not break, and bending durability can be improved. The joint structure of a coil spring according to the present invention is applied to both ends of a single coil spring to form an endless coil spring, and is used in garter springs that are used in places that are repeatedly subjected to strong tensile force and bending load. Garter springs made in this way can maintain their shape and function and can be used for a long period of time. It has a great effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the joint structure of a coil spring according to the present invention, FIG. 2 is a schematic diagram showing another embodiment of the joint structure of a coil spring according to the present invention, and FIG. 3 is a schematic diagram showing another embodiment of the joint structure of a coil spring according to the present invention. Schematic diagram showing the joint structure of the spring,
and FIG. 4 are schematic diagrams showing another conventional coil spring joint structure. 10, 20... Core metal, 11, 12, 21, 22
...Coil spring, 13, 14, 23, 24...
gap.

Claims (1)

[Scope of Claims] 1 The ends of the coil spring are formed into a pitch winding with a gap, and the connecting portions of each of the ends are connected by screwing in a lap state, but the connecting portion of the end portions has a core. Coil spring joint structure characterized by gold inserted. 2. The joint structure of a coil spring according to claim 1, wherein the gap formed by the pitch winding is approximately equal to the diameter of the wire of the coil spring. 3. The joint structure of a coil spring according to claim 1, wherein the core metal is inserted into the end portion over a range where the end portion wraps or beyond. 4. The joint structure of a coil spring according to claim 1, wherein the core metal is made of a coil spring, and the wire diameter of the core metal is about half of the wire diameter of the end portion. . 5. The joint structure of a coil spring according to claim 4, wherein the outer diameter of the core metal is larger than the inner diameter of the end portion. 6. Claim 4, characterized in that the coil spring of the core metal is configured to be tightly wound.
Coil spring joint structure described in section. 7. The coil spring according to claim 4, wherein the coil spring of the core metal is configured with a pitch winding having a gap of approximately the same length as the diameter of the wire at the end. joint structure. 8. The coil spring joint structure according to claim 1, which is applicable to a garter spring.