Fastening structure using cam lever

Abstract

To provide a fastening structure using a cam lever that enables temporary tightening and main tightening with an operation only on a cam lever side and can optionally set a pressing direction of a cam lever.SOLUTION: A fastening structure using a cam lever includes: a fastening member 10 screwed to a traction member 30; and a cam lever 12 including a cam part 14, including a first contact part and a first support part, and a second contact part and a second support part and configured such that a longest distance between the second contact part and the second support part becomes longer than a longest distance between the first contact part and the first support part. The fastening member 10 is supported by the first support part or the second support part in the cam part 14. The fastening member 10 slides between the first support part and the second support part with a switching operation of the cam lever 12 between the erecting position and inclined position.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a tightening structure, and more particularly to a tightening structure that uses a cam lever for final tightening. [Background technology]

[0002] A fastening structure that uses a cam lever for the final tightening can achieve a high tightening force without using tools, so it is often used when frequent attachment and detachment is required or in narrow spaces where there is little space to insert tools.

[0003] A commonly known fastening structure using a cam lever is disclosed in Patent Document 1. The fastening structure disclosed in Patent Document 1 is basically composed of a skewer member that penetrates the fastening element, a nut disposed at one end of the skewer member, and a cam lever disposed at the other end. The cam lever is provided with a tie nut having a screw-engagement portion disposed in a direction perpendicular to the arrangement direction of the skewer member, and this tie nut is screwed onto the skewer member and serves as a rotation axis when rotating the cam lever, thereby achieving both holding the skewer member and fastening operation by the cam lever.

[0004] In a fastening mechanism configured as described above, the fastening element is pre-fastened by a nut placed on one end of the skewer-shaped member, and then the fastening element is fully fastened by rotating the cam lever to pull the skewer-shaped member. With a fastening mechanism configured as described above, the fastening element can be fully fastened without tools, and the fastening element can be easily and quickly attached and detached.

[0005] However, in the fastening structure disclosed in Patent Document 1, it is generally necessary to place a screw element such as a nut on the end of one end side of the skewer member (the side where the cam lever is not placed) to perform temporary fastening. For this reason, temporary fastening may not be possible if the gap on one end side of the skewer member is narrow. In addition, temporary fastening can also be performed by rotating the drum nut together with the cam lever placed on the other end side of the skewer member, but this requires a space around the nut to rotate the cam lever. Furthermore, if the direction in which the cam lever is tilted is specified, the direction of the cam lever at the end of the temporary fastening state may not match the direction in which the cam lever should be tilted, which may cause a problem in which final fastening cannot be performed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5749054 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention aims to provide a tightening structure using a cam lever that makes it possible to perform preliminary tightening and final tightening by operating only the cam lever, and also allows the tilting direction of the cam lever to be determined arbitrarily. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the tightening structure using a cam lever according to the present invention has a tightening member that screws into a traction member that attracts a tightening element to be tightened, a first support portion consisting of a first contact portion and a pair of the first contact portion that contacts the tightening element when the tightening element is upright, and a second support portion consisting of a second contact portion and a pair of the second contact portion that contacts the tightening element when the tightening element is tilted, and is configured so that a maximum distance D2 between the second contact portion and the second support portion is longer than a maximum distance D1 between the first contact portion and the first support portion, and is characterized in that the tightening member is supported by the first support portion or the second support portion of the cam portion, and the tightening member slides between the first support portion and the second support portion as the cam lever switches between upright and tilted positions.

[0009] In the fastening structure using the cam lever having the above-mentioned characteristics, at least a part of the fastening member may be supported so as to straddle a pair of the cam portions arranged opposite to each other, and a stop beam may be provided between the pair of the cam portions. With such a characteristic, it is possible to prevent the cam lever from coming off the fastening member when the cam lever is operated.

[0010] In addition, the fastening member in the fastening structure using the cam lever having the above-mentioned characteristics may be a high nut having a flange portion, and the flange portion may be bridged between the pair of cam portions. With such characteristics, the range of engagement with the male thread portion provided on the towing member can be made wide. Even if the range of engagement is wide, the protrusion width above the support surface can be suppressed, so that the height of the entire fastening structure can be suppressed.

[0011] Furthermore, it is desirable that the flange portion in the fastening structure using the cam lever having the above-mentioned characteristics is provided with a support that is subjected to at least one of anti-slip processing and enlargement processing. By having such a characteristic, it is possible to make the fastening member easier to turn, and temporary fastening can be performed efficiently. Effect of the Invention

[0012] According to the tightening structure using the cam lever having the above-mentioned characteristics, it is possible to perform pre-tightening and final tightening by operating only the cam lever. In addition, since there is no need to rotate the cam lever when pre-tightening, the tilt direction of the cam lever can be determined arbitrarily. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is an exploded perspective view showing the configuration of a fastening structure using a cam lever according to an embodiment. [Diagram 2] FIG. 4 is a cross-sectional view showing a configuration of a clamping nut, which is an example of a clamping member used in the embodiment. [Diagram 3] FIG. 4 is a cross-sectional view showing a configuration of a cam lever used in the embodiment. [Figure 4] FIG. 4 is a perspective view showing a configuration of a cam lever used in the embodiment. [Diagram 5] 10 is an exploded cross-sectional view for explaining an assembly sequence when applying a fastening structure using a cam lever according to an embodiment. FIG. [Figure 6] 11 is a cross-sectional view for explaining a provisionally fastened state in a fastening structure using a cam lever according to an embodiment. FIG. [Figure 7] 11 is a cross-sectional view for explaining a final fastening state in a fastening structure using a cam lever according to an embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiment of the fastening structure using a cam lever of the present invention will be described in detail with reference to the drawings. Note that the embodiment shown below is a part of the preferred embodiment of the present invention, and even if a part of the configuration is changed, it can be considered as an embodiment of the invention as long as the effect of the invention is exhibited.

[0015] [composition] First, a configuration in the case where a fastening structure using a cam lever according to this embodiment is applied will be described with reference to Fig. 1 to Fig. 4. In the drawings, Fig. 1 is an exploded perspective view showing the configuration of a fastening structure using a cam lever according to this embodiment. Fig. 2 is a cross-sectional view showing the configuration of a fastening nut, which is an example of a fastening member used in this embodiment, and Fig. 3 is a cross-sectional view showing the configuration of a cam lever used in this embodiment. Furthermore, Fig. 4 is a perspective view showing the configuration of a cam lever used in this embodiment.

[0016] The tightening structure using a cam lever according to the embodiment (hereinafter simply referred to as the tightening structure) is basically composed of a tightening member 10, a cam lever 12, and a towing member 30. In this embodiment, the tightening element 40 is a roof bar 42 that is attached to the roof of an automobile or the like, and a mounting bracket 44 that is fixed to this roof bar 42, and the towing member 30 is a U-bolt that is arranged to straddle the underside of the roof bar 42.

[0017] The fastening member 10 is an element that screws into the towing member 30, and the fastening structure according to the embodiment is fully fastened by lifting the fastening member 10 in a direction away from the fastening element 40. In this embodiment, a nut (fastening nut) is used as the fastening member 10, and the towing member 30 is provided with a male screw portion 30a. This fastening member 10 is a high nut having a flange portion 10a at one end in the axial direction of the nut. By adopting a high nut having such a configuration as the fastening member 10, the part supported by the cam lever 12 can be the flange portion 10a, and it is possible to widen the screwing range of the fastening member 10 while suppressing the height of the entire fastening structure. Therefore, it is possible to avoid a situation in which the male screw portion 30a of the towing member 30 protrudes from the fastening member 10 and interferes with the rotation operation of the cam lever 12. Furthermore, in the fastening member 10 according to this embodiment, supports 10b are provided on the flange portion 10a to facilitate the screwing and temporary fastening of the fastening member 10. It goes without saying that the size of the flange portion 10a may be changed so that it has the function of the supports 10b.

[0018] The cam lever 12 serves to pull up the clamping member 10 in a direction away from the clamping element 40 by means of a switching operation between upright and tilted positions. The cam lever 12 is basically composed of a cam portion 14, a lever base end portion 16, and a pressing portion 18. The cam portion 14 has a first contact portion 14a1, a first support portion 14a2 paired with the first contact portion 14a1, a second contact portion 14b1, and a second support portion 14b2 paired with the second contact portion 14b1. Here, the first contact portion 14a1 is a portion (surface, line, or multiple points) that contacts the clamping element 40 when the cam lever 12 is in the upright position, and the second contact portion 14b1 is a portion (surface, line, or multiple points) that contacts the clamping element 40 when the cam lever 12 is in the tilted position. Also, the first support portion 14a2 is a surface that supports the clamping member 10 when the cam lever 12 is in the upright position, and the second support portion 14b2 is a surface that supports the clamping member 10 when the cam lever 12 is in the tilted position. Further, arc-shaped connecting surfaces 14c1 and 14c2 are provided between the first contact portion 14a1 and the second contact portion 14b1, and between the first support portion 14a2 and the second support portion 14b2, respectively, so as to facilitate the rolling of the cam lever 12 and the sliding of the clamping member 10.

[0019] Also, the first contact portion 14a1 and the first support portion 14a2, and the second contact portion 14b1 and the second support portion 14b2 are configured to be parallel to each other. When the longest distance between the first contact portion 14a1 and the first support portion 14a2 is D1, and the longest distance between the second contact portion 14b1 and the second support portion 14b2 is D2, they are configured such that the relationship D1 < D2 holds. With such a configuration, it becomes possible to pull up the clamping member 10 as the cam lever 12 tilts.

[0020] The lever base end portion 16 is configured by arranging a pair of cam portions 14 opposite to each other, and the pressing portion 18 is a plate-like piece provided so as to straddle the pair of cam portions 14 constituting the lever base end portion 16. Note that in this embodiment, the upright and tilted positions of the cam lever 12 are determined by the direction of the pressing portion 18. The state where the pressing portion 18 is arranged parallel to the traction member 30 is defined as "upright", and the state where the pressing portion 18 is arranged in a direction intersecting the traction member 30 is defined as "tilted".

[0021] The cam lever 12 according to this embodiment is configured to have anti-slip beams 20a, 20b provided between a pair of cam portions 14 at the portion of the cam portion 14 located at the stop end when the cam lever 12 is erected and at the portion of the cam portion 14 located at the stop end when the cam lever 12 is tilted. By providing the anti-slip beams 20a, 20b, it is possible to prevent the fastening member 10 from coming off the cam lever 12, and it is possible to ensure the stability of rotational operations such as erecting and tilting.

[0022] [Actions and Effects] Next, an example of an application form of the fastening structure having the above-mentioned characteristics will be described with reference to Figures 5 to 7. First, as shown in Figure 5, a U-bolt as the pulling member 30 is arranged on the roof bar 42 and the mounting bracket 44 as the fastening element 40, and the male thread portion 30a of the pulling member 30 is inserted between the pair of cam portions 14 of the cam lever 12 and the pair of retaining beams 20a, 20b.

[0023] With the male screw portion 30a inserted into the cam lever 12, the fastening member 10 is screwed into the male screw portion 30a. The flange portion 10a (support 10b in this embodiment) of the fastening member 10 is supported by being hung across a pair of cam portions 14 that constitute the cam lever 12. Therefore, the cam lever 12 is held down by the fastening member 10, and the cam lever 12 itself is prevented from coming off. As a result, the cam lever 12 according to this embodiment can be rotated to switch between an upright state and a tilted state without having a rotation axis that intersects with the male screw portion 30 of the traction member 30.

[0024] In addition, since the fastening member 10 does not support the rotation axis of the cam lever 12, it is possible to adjust the fastening state with respect to the male thread portion 30a by rotating only the fastening member 10. In the fastening structure according to the embodiment, the fastening member 10 is fastened after the cam lever 12 is set in the upright state, and the traction member 30 is temporarily fastened.

[0025] After the temporary tightening of the pulling member 30 is completed, the pressing portion 18 of the cam lever 12 is pushed in the tilting direction (the direction indicated by the arrow a) as shown in FIG. 6, thereby tilting the cam lever 12 as shown in FIG. 7. The tightening member 10 is regulated in its axial tilt by the male thread portion 30a of the pulling member 30, so that the tightening member 10 tries to maintain its position. Therefore, when the cam lever 12 is tilted, the flange portion 10a (support 10b) of the tightening member 10 slides on its support surface, and the supporting surface is switched from the first support portion 14a2 to the second support portion 14b2. The distance D1 between the first contact portion 14a1 and the first support portion 14a2 is shorter than the distance D2 between the second contact portion 14b1 and the second support portion 14b2. As a result, as the support distance changes from D1 to D2 due to tilting of the cam lever 12, the fastening member 10 is pulled in a direction away from the mounting bracket 44 constituting the fastening element 40 (indicated by arrow b), and final fastening is completed.

[0026] In this way, according to the tightening structure of this embodiment, it is possible to perform pre-tightening and final tightening by operating only the cam lever 12 side (the front side of the tightening element 40) without operating the back side of the tightening element 40. In addition, since there is no need to rotate the cam lever 12 when performing pre-tightening, the tilting direction of the cam lever 12 can be determined as desired.

[0027] In the above embodiment, it has been described that a long nut having a flange portion 10a is used as the fastening member 10. However, if support by the cam portion 14 is possible, a normal nut can also be used as the fastening member 10. Also, in the above embodiment, it has been described that the fastening member 10 is a nut and the pulling member 30 is provided with a male thread portion 30a. However, the fastening member 10 in the present application may be a bolt, or the pulling member 30 may be provided with a female thread portion and screwed into this. In such a configuration, it is preferable to support the fastening member 10 by having the bolt head of the bolt that constitutes the fastening member 10 span the pair of cam portions 14.

[0028] Also, in the above-described embodiment, it has been described that the first contact portion 14a1 and the first support portion 14a2, and the second contact portion 14b1 and the second support portion 14b2 in the cam portion 14 each have parallel surfaces. However, the first contact portion 14a1 and the first support portion 14a2, and the second contact portion 14b1 and the second support portion 14b2 do not necessarily have to be parallel, and it is sufficient that the respective longest distances D1 and D2 have a relationship of D1 < D2. If it has such a feature, it becomes possible to lift the clamping member 10 by operating the cam lever 12. For this reason, if the clamping member 10 can be slid between the first support portion 14a2 and the second support portion 14b2, the first contact portion 14a1, the first support portion 14a2, the second contact portion 14b1, and the second support portion 14b2 do not have to be surfaces, and may be constituted by linear portions, or a plurality of protrusions (dot-like portions).

Explanation of Signs

[0029] 10......... clamping member, 10a......... flange portion, 10b......... support, 12......... cam lever, 14......... cam portion, 14a1......... first contact portion, 14a2......... first support portion, 14b1......... second contact portion, 14b2......... second support portion, 14c1, 14c2......... connection surface, 16......... lever base end portion, 18......... pressing portion, 20a, 20b......... retaining beams, 30......... traction member, 30a......... male screw portion, 40......... clamping element, 42......... roof bar, 44......... mounting bracket.

Claims

1. A tightening member that is screwed onto a pulling member that attracts the tightening element to be tightened; a cam lever having a cam portion including a first contact portion that contacts the tightening element when the lever is upright and a first support portion that is configured as a pair with the first contact portion, and a second contact portion that contacts the tightening element when the lever is tilted and a second support portion that is configured as a pair with the second contact portion, the cam portion being configured such that a maximum distance D2 between the second contact portion and the second support portion is longer than a maximum distance D1 between the first contact portion and the first support portion; A tightening structure using a cam lever, characterized in that the tightening member is supported by the first support portion or the second support portion of the cam portion, and the tightening member slides between the first support portion and the second support portion as the cam lever switches between upright and tilted positions.

2. At least a portion of the fastening member is supported so as to straddle the pair of cam portions disposed opposite to each other, 2. The fastening structure using a cam lever according to claim 1, wherein a stopper beam is suspended between the pair of cam portions.

3. 3. The fastening structure using a cam lever according to claim 2, wherein the fastening member is a high-tension nut having a flange portion, and the flange portion is bridged between the pair of cam portions.

4. 4. The fastening structure using a cam lever according to claim 3, characterized in that the flange portion is provided with a support that is subjected to at least one of anti-slip processing and enlargement processing.

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