JP5554222B2 - Spiral spring - Google Patents

Description

  The present invention relates to a spiral spring obtained by forming a spring wire into a spiral shape.

  Spiral springs are widely used in automobile seat recliners and window regulators. This type of spiral spring has a spring wire formed into a spiral shape. The spring wire usually has an inner attachment portion attached to an inner peripheral end thereof and an outer attachment portion attached to an outer peripheral end thereof. The outer mounting portion can be displaced within a predetermined angle range with respect to the inner mounting portion. When the outer attachment portion is displaced with respect to the inner attachment portion, the spiral spring is deformed to the attachment state (the state where the initial load acts on the spiral spring) to the maximum load state (the state where the maximum load acts on the spiral spring 10). Can change. When the spiral spring is in the maximum load state, a force in a direction to restore the spiral spring from the maximum load state to the attached state is generated in the spiral spring.

  Among such spiral springs, as shown in Patent Document 1, there is a case where the spiral spring is attached to an inner attachment portion in which a cross section in a direction perpendicular to the axis is rectangular. That is, the outer peripheral surface of the inner mounting portion has a first plane, a second plane, a third plane, and a fourth plane that are arranged so that the cross section is rectangular. In the spiral spring of Patent Document 1, in order to attach the spring wire to the inner attachment portion having a rectangular cross section, a locking portion that follows the outer peripheral surface of the inner attachment portion is formed at the inner peripheral end of the spring wire. The relative movement between the spring wire and the inner mounting portion is regulated by fitting the locking portion to the inner mounting portion.

JP 2003-148533 A

  In the conventional spiral spring, as shown in FIG. 4, the locking portion formed at the inner peripheral end of the spring wire is formed in a shape that follows each of the first to fourth planes of the inner attachment portion. For this reason, if the spiral spring is to be changed from the mounted state to the maximum load state, the spring wire constituting the locking portion and the spring wire on the outer side thereof are in contact with each other at a plurality of locations, and the spring wire is deformed freely. Was inhibited. As a result, in the conventional spiral spring, when the spiral spring is changed from the mounted state to the maximum load state, the force applied to the spiral spring increases rapidly, and the angle range in which linear spring characteristics can be obtained is narrow. Had.

  For this reason, in the spiral spring of patent document 1, a processus | protrusion is formed in the outer surface of an inner side spring wire, or the inner surface of an outer spring wire, and reduction of the contact area when spring wires contact each other is achieved. Yes. When the contact area between the opposing spring wires is reduced, the frictional force generated between the spring wires is also reduced. As a result, the above-described problem is solved. However, since the technique of Patent Document 1 is not a technique for restricting the contact between the spring wire constituting the locking portion and the outer spring wire at a plurality of locations, a sufficient effect cannot be obtained.

  The present application has been made in view of the above-described circumstances, and is a spiral spring that can obtain a linear spring characteristic in a wider angle range as compared with the conventional spiral spring attached to an inner mounting portion having a rectangular cross section. The purpose is to provide.

  The spiral spring of the present application has a first plane, a second plane, a third plane, and a fourth plane that are arranged so that the cross section is rectangular, and an outer peripheral surface that has four corners connecting adjacent planes. It is attached to the provided inner attachment part. This spiral spring includes a spring wire formed in a spiral shape. At the end portion on the inner peripheral side of the spring wire, a locking portion having a shape following three planes among the four planes of the inner attachment portion is formed. The locking portion is provided at the inner circumferential end of the spring wire, and is provided adjacent to the first locking portion having a shape following the first plane of the inner mounting portion, and the inner side. A second locking portion having a shape following the second plane adjacent to the first plane of the mounting portion; and a third plane provided adjacent to the second locking portion and adjacent to the second plane of the inner mounting portion. A third locking portion having a shape to follow is provided. When the inner attachment portion is viewed from the axial direction with the spiral spring attached to the inner attachment portion, the tip of the first locking portion is between the middle position of the first plane and the end on the fourth plane side. Is located.

  In this spiral spring, the locking portion provided at the end portion on the inner peripheral side of the spring wire is formed in a shape that follows the three planes of the outer peripheral surface of the inner attachment portion. For this reason, when a load is applied to the spiral spring, the contact between the spring wire constituting the locking portion and the outer spring wire is prevented at a plurality of locations. As a result, it is possible to obtain a linear spring characteristic in a wider angle range as compared with the conventional case. On the other hand, even if the locking portion has a shape that follows three planes, the first locking portion has a shape that follows at least half of the first plane. For this reason, relative movement between the spiral spring and the inner mounting portion is restricted, and the function as the spiral spring can be exhibited.

  In the spiral spring, the locking portion formed on the spring wire is provided between the first locking portion and the second locking portion, and a corner portion that connects the first plane and the second plane of the inner mounting portion. The first corner portion having a shape that follows the shape, and the second corner portion that is provided between the second locking portion and the third locking portion, and has a shape that follows the corner portion that connects the second plane and the third plane of the inner mounting portion. And two corners.

  In the above spiral spring, when the spiral spring is attached to the inner attachment portion, the spiral spring is attached by displacing the outer peripheral end of the spring wire with respect to the inner peripheral end of the spring wire within a predetermined angular range. When the spiral spring is in the maximum load state, the spring wire constituting the latching portion and the outside of the latching portion are arranged only at the first corner of the latching portion. It is preferable that the spring wire which is located contacts. According to such a configuration, since the contact between the spring wires can be suppressed without increasing the distance between the inner spring wire and the outer spring wire, linear spring characteristics can be obtained in a limited space. The range of angles that can be made can be made wider.

  Moreover, in said spiral spring, it is preferable that the mutually opposing surface of the spring wire shape | molded by the spiral shape is a flat plane, and the convex part is not formed. According to such a structure, since it is not necessary to form a convex part in the opposing surface of a spring wire, surface processing of a spring wire becomes unnecessary and a spiral spring can be manufactured easily. Moreover, the shape at the time of a maximum load can be made small by the part by which a convex part is not formed.

The top view (attachment state) of the spiral spring which concerns on a present Example. The top view of the spiral spring which concerns on a present Example (the intermediate state which transfers to a maximum load state from an attachment state). The figure which expands and shows the edge part of the inner peripheral side of the spiral spring of a present Example. The top view (attachment state) of the spiral spring which concerns on a comparative example. The graph which shows together the spring characteristic of the spiral spring of a present Example, and the spring characteristic of the spiral spring of a comparative example. The figure which combines and shows the calculation example which calculated the contact pressure which arises on the surface of the spring wire of the spiral spring of a present Example, and the calculation example which calculated the contact pressure which arises on the surface of the spring wire of the spiral spring of a comparative example.

  A spiral spring 10 according to the present embodiment will be described with reference to the drawings. The spiral spring 10 according to the present embodiment is used as a return spring for a recliner for an automobile seat. As shown in FIG. 1, the spiral spring 10 is constituted by a spring wire 12 formed in a spiral shape, and a predetermined interval is provided between the spring wires 12. The spring wire 12 is formed of a strip-shaped steel material (for example, a hard steel wire material). The mutually opposing surfaces (that is, the inner surface and the outer surface) of the spring wire 12 are flat surfaces, and no convex portions are formed on these surfaces. Further, a lubricating film is formed on the surface of the spring wire 12. The lubricating coating can be formed by a reactive lubricant treatment, a coating-type lubricant treatment, a coating-type lubricant treatment, or the like. Typically, a metal soap can be used for the lubricating coating.

  As shown in FIG. 3, one end of the spring wire 12 (an inner peripheral end formed in a spiral shape) is attached to the inner attachment portion 30. The inner mounting portion 30 is fixed to a housing (not shown), and is formed so that a cross-sectional shape in a direction perpendicular to the axis is a rectangular shape. That is, the outer peripheral surface of the inner mounting portion 30 has four corners 34, 38, 42, and 46 that connect the first plane 32, the second plane 36, the third plane 40, and the fourth plane 44 and the adjacent planes. have.

  An inner locking portion 24 is formed at the inner peripheral end of the spring wire 12. The inner locking portion 24 has a shape that follows three of the four planes of the inner mounting portion 30. That is, the inner locking portion 24 includes a first locking portion 14 that follows the first plane 32 of the inner mounting portion 30, a second locking portion 18 that follows the second plane 36 of the inner mounting portion 30, and an inner mounting portion. It has the 3rd latching | locking part 22 which follows the 3rd plane 40 of 30. Further, the inner locking portion 24 includes a corner portion 16 that follows the corner portion 34 that connects the first plane 32 and the second plane 36, and a corner portion that follows the corner portion 38 that connects the second plane 36 and the third plane 40. 20 and a corner 23 that follows the corner 42 connecting the third plane 40 and the fourth plane 44. The spiral spring 10 is attached to the inner attachment portion 30 by the inner locking portion 24 being fitted on the outer peripheral surface of the inner attachment portion 30. Note that “following” here also means that both are in contact with each other so that no gap is formed between the inner locking portion 24 and the outer peripheral surface of the inner mounting portion 30. Absent. For this reason, even if there is a gap between the inner locking portion 24 and the outer peripheral surface of the inner mounting portion 30, if the gap is substantially negligible, it corresponds to "following" here. To do.

  When the spiral spring 10 and the inner attachment portion 30 are viewed from the axial direction in a free state in which the spiral spring 10 is simply attached to the inner attachment portion 30 (a state in which no load is applied to the spiral spring 10) (ie, in FIG. When viewed as shown), the tip end 14a of the first locking portion 14 is located at the end (D in the drawing) on the fourth plane 44 side of the first plane 32 from the center position (C in the drawing) of the first plane 32. The length of the 1st latching | locking part 14 is adjusted so that it may be located in the range to. On the other hand, the second locking portion 18 is shaped to follow the range from the end of the second plane 36 on the first plane 32 side to the end of the third plane 40 side, and the third locking portion 22 The third plane 40 is shaped to follow the range from the end on the second plane 36 side to the end on the fourth plane 44 side.

  An outer locking portion 26 is formed at the outer peripheral end of the spring wire 12 (see FIG. 1 and the like). When the spiral spring 10 is attached to the automobile seat recliner, the outer locking portion 26 is connected to an operation lever of the automobile seat recliner (not shown).

  When the spiral spring 10 is attached to the recliner of the automobile seat, when the operator rotates the operation lever of the recliner, the rotation operation is transmitted to the outer locking portion 26. The inner locking portion 24 of the spiral spring 10 is attached to the inner attachment portion 30 so as not to rotate. Therefore, when the lever operation of the operator is transmitted to the outer locking portion 26, the outer locking portion 26 rotates (displaces) in the circumferential direction with respect to the inner mounting portion 30, as shown in FIG. When the outer locking portion 26 rotates in the circumferential direction with respect to the inner mounting portion 30, the spiral spring 10 is deformed, and the interval between the spring wire 12 located on the inner side and the spring wire 12 located on the outer side becomes narrower and restored. Force is generated. For this reason, if the force which operates the operation lever of a recliner is cancelled | released, the spiral spring 10 will return to an original shape, and the space | interval of the spring wire 12 located inside and the spring wire 12 located outside will become large.

  In the automobile seat recliner, the angle range in which the operation lever can be operated is restricted, and thus the range in which the outer locking portion 26 can rotate with respect to the inner attachment portion 30 is also restricted. Further, when the operation lever is in the attachment position (attachment state), an initial load is set on the operation lever. That is, the outer locking portion 26 is mounted in a mounting state (position indicated by a two-dot chain line in FIG. 2) rotated from a free state (that is, a state where no load is applied to the spiral spring 10) by a predetermined angle. It rotates to the maximum load state (the state where the maximum load is applied to the spiral spring 10 (the position further rotated from the position shown by the solid line in FIG. 2)) in which the operator rotates the operating lever to the maximum. When the spiral spring 10 is in a free state or an attached state, a predetermined interval is formed between the spring wires 12 of the spiral spring 10. That is, the inner spring wire 12 and the outer spring wire 12 do not contact each other. On the other hand, when the spiral spring 10 reaches the maximum load state, the gap between the opposing spring wires 12 is reduced, and the corner 16 of the inner locking portion 24 (the first locking portion 14 and the second locking portion 18 are connected). The spring wire 12 constituting the inner locking portion 24 and the spring wire 12 positioned outside thereof are in contact with each other.

  Next, the spring characteristics of the spiral spring 10 described above will be described in comparison with the spiral spring 50 of the comparative example shown in FIG. The spiral spring 50 of the comparative example is different from the spiral spring 10 of the present embodiment in that the inner locking portion 54 is formed in a shape that follows all four planes constituting the outer peripheral surface of the inner mounting portion. The material and outer diameter of the wire are the same as those of the spiral spring 10 of this embodiment. FIG. 5 is a diagram illustrating both the spring characteristics of the spiral spring 10 according to the present embodiment and the spring characteristics of the spiral spring 50 according to the comparative example. 5 indicates the torque (restoring force) generated by the spiral spring, and the horizontal axis in FIG. 5 indicates the rotation angle of the outer locking portion (26 or 56) with respect to the inner locking portion (24 or 54). Is shown. As is apparent from the figure, the spiral spring 10 of this embodiment has a linear spring characteristic when the rotation angle of the outer locking portion 26 is in the range of 0 to 145 °. On the other hand, the spiral spring 50 according to the comparative example exhibits linear spring characteristics when the rotation angle of the outer locking portion 56 is in the range of 0 to 130 °, but is generated from the spiral spring 50 when the rotation angle exceeds 130 °. Torque increases rapidly. Therefore, it turns out that the spiral spring 10 of a present Example has a linear spring characteristic in a wide angle range rather than the spiral spring 50 of a comparative example. As a result, the spiral spring 10 of this embodiment achieves a linear spring characteristic within an angular range in which the outer locking portion 26 rotates from the mounted state to the maximum load state.

The reason why the spiral spring 10 of the present embodiment has linear spring characteristics in a wider angle range than the spiral spring 50 of the comparative example is considered to be as follows. FIG. 6A is a result of obtaining the contact pressure generated on the surface of the spring wire 12 when the spiral spring 10 of the present embodiment is in the maximum load state by simulation, and FIG. 6B is a comparison example. It is the result of having calculated | required by the simulation the contact pressure which arises on the surface of the spring wire 52 when the spiral spring 50 is made into a maximum load state. In the figure, the portion where the color is displayed light is the portion where the contact pressure is high, and is the portion where the spring wires are in contact. 6 (a) and 6 (b), it seems that a gap is formed between the spring wires in the portion where the contact pressure is high (the portion where the color is thin). This is because the plate thickness of the spring wire is not considered in the simulation. Also, in FIGS. 6A and 6B, an outer mounting portion (a circular portion displayed on the outer locking portion) that engages with the outer locking portion 26 is also displayed.
As shown in FIG. 6A, in the spiral spring 10 of the present embodiment, the spring wire 12 constituting the inner locking portion 24 and the spring wire 12 positioned outside the inner locking portion 24 are connected to the inner side. Contact is made only at the corner 16 of the stopper 24 (the corner connecting the first locking portion 14 and the second locking portion 18). For this reason, in the spiral spring 10 of a present Example, it will be suppressed that the deformation | transformation of the spring wire 12 is restrained and the contact pressure which arises on the surface of the spring wire 12 is also suppressed low. On the other hand, as shown in FIG. 6B, in the spiral spring 50 of the comparative example, the spring wire 52 constituting the inner locking portion 54 and the spring wire 52 positioned outside the inner locking portion 54 are 3 Two corners (i.e., the corner corresponding to the corner connecting the first locking portion and the second locking portion of this embodiment, the corner connecting the second locking portion and the third locking portion) The corresponding portion, the portion corresponding to the corner portion connecting the third locking portion and the fourth locking portion). For this reason, in the spiral spring 50 of the comparative example, it is considered that the deformation of the spring wire 52 is largely restricted, and the contact pressure generated on the surface of the spring wire 52 is also high. As a result, in the spiral spring 10 of this embodiment, it is considered that linear spring characteristics can be realized in a wider angle range than the spiral spring 50 of the comparative example.

  In addition, even if the inner locking portion has a shape that follows the four planes constituting the outer peripheral surface of the inner mounting portion as in the spiral spring 50 of the comparative example, the contact between the spring wires can be increased by widening the spacing between the spring wires. It is possible to prevent and obtain a linear spring characteristic in a wide angle range. However, when the interval between the spring wires is widened, the outer diameter of the spiral spring becomes larger, and there arises a problem that the position of the outer mounting portion must be moved radially outward. Therefore, in the configuration in which the inner locking portion is shaped to follow the four planes constituting the outer peripheral surface of the inner mounting portion as in the spiral spring 50 of the comparative example, the spiral spring can be downsized and the spring is linear over a wide angle range. The two effects of obtaining characteristics cannot be realized simultaneously.

  Further, in the spiral spring 10 of this embodiment, the inner locking portion 24 has a shape that follows only the three flat surfaces 32, 36, and 40 of the outer peripheral surface of the inner mounting portion 30. By adjusting the position of the tip 14a, the inner locking portion 24 is prevented from rotating with respect to the inner mounting portion 30. That is, in the spiral spring 10 of the present embodiment, when the spiral spring 10 is attached to the inner attachment portion 30, when the spiral spring 10 and the inner attachment portion 30 are viewed from the axial direction (as shown in FIG. 3). The distal end 14a of the first locking portion 14 is located in a range from the center position (C in the figure) of the first plane 32 to the end (D in the figure) of the first plane 32 on the fourth plane 44 side. Further, the length of the first locking portion 14 is adjusted. As a result, the inner locking portion 24 is restricted from rotating with respect to the inner mounting portion 30.

  Table 1 shows the spiral spring with the tip of the first locking portion 14 changed in position, mounted on an actual automobile seat recliner, and when the operating lever is operated, the inner locking portion is against the inner mounting portion. The result of the experiment which confirmed whether it rotated was shown. As can be seen from Table 1, the front end 14a of the first locking portion 14 is located on the fourth plane 44 side from the center position (C in the figure) of the first plane 32, so that the inner mounting of the inner locking portion 24 is achieved. The rotation with respect to the portion 30 could be prevented.

  As described above, in the spiral spring 10 of this embodiment, the inner locking portion 24 is shaped to follow the three planes 32, 36, and 40 of the inner mounting portion 30, so that the spring wire 12 between the spiral springs 10 is formed. A linear spring characteristic can be realized in a wide range without widening the interval. Further, the inner locking portion 24 can be prevented from rotating with respect to the inner mounting portion 30 by adjusting the position of the tip 14a of the inner locking portion 24 as described above.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. For example, the material of the spring wire is not limited to carbon steel, and known materials such as stainless steel and copper can be used.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

10 spiral spring 12 spring wire 24 inner locking portion 26 outer locking portion 30 inner mounting portion

Claims (4)

On the inner mounting portion having an outer peripheral surface having four corners connecting the adjacent planes, and the first plane, the second plane, the third plane, and the fourth plane arranged so that the cross section is rectangular. A spiral spring mounted,
It has a spring wire formed in a spiral shape,
At the end on the inner peripheral side of the spring wire, a locking portion having a shape following the three planes among the four planes of the inner mounting portion is formed,
The locking part is
A first locking portion provided at an inner circumferential end of the spring wire, and having a shape following the first plane of the inner mounting portion;
A second locking portion provided adjacent to the first locking portion and having a shape following the second plane adjacent to the first plane of the inner mounting portion;
A third locking portion provided adjacent to the second locking portion and having a shape following the third plane adjacent to the second plane of the inner mounting portion;
When the inner attachment portion is viewed from the axial direction with the spiral spring attached to the inner attachment portion, the tip of the first locking portion is located between the middle position of the first plane and the end portion on the fourth plane side. A spiral spring. The locking part formed on the spring wire is
A first corner portion provided between the first locking portion and the second locking portion and having a shape following the corner portion connecting the first plane and the second plane of the inner mounting portion;
A second corner portion provided between the second locking portion and the third locking portion and having a shape following the corner portion connecting the second plane and the third plane of the inner mounting portion;
The spiral spring according to claim 1, further comprising: When the spiral spring is mounted on the inner mounting portion, the spiral spring can be changed from the mounted state to the maximum load state by displacing the outer peripheral end of the spring wire with respect to the inner peripheral end of the spring wire within a predetermined angle range. Has been
The spring wire material which comprises a latching | locking part and the spring wire material located in the outer side of the latching | locking part contact only in the 1st corner | angular part of a latching | locking part when a spiral spring is made into a maximum load state. The spiral spring described in 1.   The spiral spring according to any one of claims 1 to 3, wherein the mutually facing surfaces of the spirally shaped spring wire are flat planes, and no protrusion is formed.