Clamp with hinge

Abstract

Provided is a hinge structure capable of preventing the phenomenon in which a hinge that links a lid and a body cracks in the course of work to close the lid with respect to the body.　This clamp is configured so that a first member and a second member are linked by a hinge and bending the hinge brings the first member and the second member into mutual contact. The hinge comprises: outer portions that extend to the same lengths, in a constant thickness, from the first member and the second member; a central portion that is located between the outer portions and is thinner than the outer portions; and curved portions that extend between the respective outer portions and the central portion. The curved portions are curved so that, when the hinge is extended, the shapes of the curved portions that form the outer side when the hinge is bent are such that the curved portions become gradually thinner from the outer portions toward the central portion. When the hinge is extended, the shape of the hinge that forms the inner side when the hinge is bent is straight from the first member to the second member.

Description

hinged clamp

[0001] The present invention relates to clamps, and more particularly to clamps with a hinged lid and body.

[0002] One-piece molded parts, in which the lid and body are connected by a hinge, are widely used in various industries due to the convenience of integrated parts and the reduction in the number of molding dies required. In the automotive industry, pipe clamps with hinged lids are used to secure long parts such as vehicle piping and hoses to vehicles. One-piece molded parts with hinged lids are also used in protectors that house electrical wires and wiring harnesses. The materials used for one-piece molded parts are selected appropriately depending on the location and environment of use. For example, polyamide-based plastics are selected for high-temperature areas, while plastics such as polypropylene and polyethylene are selected for areas requiring chemical resistance. For pipe clamps placed under the vehicle floor, polypropylene (PP) and semi-aromatic polyamide (PA6T) are selected for their acid resistance. One-piece molded parts with hinged lids and bodies are known to improve the ease of pipe assembly and reduce costs.

[0003] However, if the length of the hinge portion is increased, a gap will be created between the lid and the main body after the lid is closed, creating a gap between the lid and the object being fastened, which can cause the fastened object to rattle due to vehicle vibration. To address this issue, the gap between the lid and the main body (the length of the hinge portion) must be narrowed in order to bend the hinge with the smallest radius after the lid is closed. Furthermore, in a hinge structure where the hinge portion is uniform in thickness, flat, and parallel, and the hinge bending angle is 180°, the hinge bending may only begin in a narrow range biased to the left or right of the base of the hinge due to the processing accuracy of the mold, and the hinge shape after the lid is closed may not be as expected.

[0004] This causes the starting point of the bending to change during the rotational movement of the hinged lid when it is closed, increasing the strain on the hinge.In other words, a one-piece molded product in which the lid and body are connected by a hinge requires high processing precision in the mold, and it is necessary to adjust the mold, which requires precision, to prevent the above-mentioned effects from the hinge bending, and to check the state of the hinge bending on the molded product.

[0005] Conventional hinge structures include those shown in Patent Documents 1 to 4 that control the shape of the starting point of the hinge bending when the lid is closed to prevent the hinge from cracking when the lid is closed. However, hinge structures in which the bending angle of the hinge is 180° can cause the hinge to crack when the lid is closed, and more effective improvements are desired.

[0006] JP 10-185003, JP 2020-149938, JP 2014-043909, JP 09-137823

[0007] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a hinge structure that can prevent the hinge from cracking during the lid closing operation.

[0008] To achieve this object, one aspect of the present invention is a clamp in which a first member and a second member are connected by a hinge, and the first member and the second member are configured to abut when the hinge is bent, wherein the hinge comprises: outer portions extending from the first member and the second member of the same length and with a constant thickness; a central portion located between the outer portions and thinner than the outer portions; and curved portions extending between each of the outer portions and the central portion, wherein the shape of the curved portions that become outer when the hinge is bent is curved so that the thickness of the curved portions gradually decreases from the outer portions toward the central portion when the hinge is extended; and the shape of the hinge that becomes inner when the hinge is bent is a straight shape from the first member to the second member when the hinge is extended.

[0009] Preferably, in the clamp, the hinge is made of polypropylene.

[0010] According to the present invention, a hinge structure can be obtained that can prevent the hinge connecting the lid and the main body from cracking during the operation of closing the lid on the main body.

[0011] Fig. 1 is a perspective view of a hinged clamp according to an embodiment of the present invention; Fig. 2 is a side view of a hinge structure of a hinged clamp according to an embodiment of the present invention; Fig. 3 is a diagram showing the hinge structure of a hinged clamp according to an embodiment of the present invention when the hinge bending angle is 180°; Fig. 4 is a diagram showing the results of an experiment evaluating the hinge structure of a hinged clamp according to an embodiment of the present invention and a conventional hinge structure.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] 1 shows a perspective view of a hinged clamp 100 according to an embodiment of the present invention. The hinged clamp 100 is a pipe clamp commonly used to secure, for example, piping arranged under the floor of an automobile, or fuel or brake piping, to the vehicle body.

[0014] The hinged clamp 100 has a body portion 130, hinges 110, 120, and lid portions 140, 150 connected to the hinges 110, 120. The hinged clamp 100 is a one-piece molded pipe clamp in which the lid portions 140, 150 and the body portion 130 are connected by the hinges 110, 120, and the material of the pipe clamp is a thermoplastic, with the hinges 110, 120 preferably having hinge structures injection molded from polypropylene.

[0015] By bending the hinge 110, the lid portion 140 can be brought into contact with a predetermined location on the main body portion 130, thereby placing the lid portion 140 in a closed state, and by bending the hinge 120, the lid portion 150 can be brought into contact with a predetermined location on the main body portion 130, thereby placing the lid portion 150 in a closed state.

[0016] 2 is a side view of the hinge structure of the hinge 110 of the hinged clamp 100 according to an embodiment of the present invention. In FIG. 2, the hinge 110 is shown in the extended (open) state of the hinge 110 shown in FIG.

[0017] The hinge 110 has outer portions 220 extending from each of the ends 250 of the lid portions 140, 150 and the end 260 of the body portion 130, a central portion 210 located between the outer portions 220, and curved portions 215 extending between each of the outer portions 220 and the central portion 210.

[0018] Each of the outer portions 220 extends the same length and with a constant thickness from an end 250 of the lid portions 140, 150 and an end 260 of the main body portion 130. The central portion 210 is configured to be thinner than the outer portions 220. The curved portion 215, which faces outward (the lower side of FIG. 2 : surface B) when the hinge 110 is bent, is curved such that the thickness of the curved portion 215 gradually decreases from the outer portion 220 toward the central portion 210 when the hinge 110 is extended. The curved portion 215, which faces inward (the upper side of FIG. 2 : surface A) when the hinge 110 is bent, is straight between the end 250 and the end 260 when the hinge 110 is extended.

[0019] In this way, the hinge 110 is configured so that the part that becomes the outer side (side B) when the hinge 110 is bent gradually becomes thinner from the straight outer part 220 through the curved part 215, with the central part 210 being the thinnest part.

[0020] 3 is a diagram showing the hinge structure of the hinged clamp 100 according to the embodiment of the present invention in a state where the bending angle of the hinge 110 is 180°. As shown in FIG. 3, in this state, the ends 250 of the cover portions 140, 150 and the end 260 of the main body portion 130 abut against each other, and the cover portions 140, 150 are closed relative to the main body portion 130.

[0021] When the hinge 110 transitions from the open state of FIG. 2 to the closed state of FIG. 3 , the central portion 210 of the hinge 110 is configured to be the thinnest, which makes it possible to control the start point of bending of the hinge 110 to the central portion 210. In addition to this configuration, the outer portions 220 are not curved, but are configured to have a straight shape to avoid excessive thickness, which prevents the stress applied to the central portion 210 from concentrating on the central portion 210 until it has completely bent 180° after it starts bending. As a result, as shown in FIG. 3 , the bending propagates from the central portion 210 to the curved portion 215, causing the hinge 110 to bend in an arc shape as a whole, thereby preventing the hinge 110 from cracking.

[0022] [Evaluation Test] FIG. 4 shows the results of an experiment evaluating the hinge structure of the hinged clamp 100 according to the embodiment of the present invention and a conventional hinge structure.

[0023] The left side of Fig. 4 shows the state in which the hinge is extended for hinge structure 440a according to the present invention and comparative examples 410a, 420a, and 430a. The right side of Fig. 4 shows the state of the hinge structure 440a according to the present invention and comparative examples 410a, 420a, and 430a as stress distribution when these hinges are bent 90°.

[0024] Polypropylene was used as the hinge material for both the hinge of the present invention and the hinge of the comparative example. Pipe clamps made of polypropylene with a conventional hinge structure with a 180° bending angle have the same problem of the hinge not maintaining the expected hinge shape after the lid is closed, as with polyamide-based products. Therefore, polypropylene was used as the hinge material, and the stress distribution of the hinge when bent and whether the hinge would crack were evaluated. The distance between the main body and the lid was set to the same, and the minimum thickness of each part was defined relatively as t2 < t0 < t1.

[0025] When the stress distribution of hinge structure 440a according to the present invention is examined when hinge 442 is bent 90°, it can be seen that the greatest force is applied to the central portion at thickness t0, and that the force applied therefrom gradually decreases evenly to the left and right. In this regard, it has been confirmed that hinge structure 440a according to the present invention does not crack even when the hinge is bent 180°, and this structure is effective even when polypropylene, which has become the common hinge material in recent years, is used.

[0026] In contrast, in comparative example 410a, the thickness (t1) of hinge 412 is uniform, so the stress when bent 90 degrees is not greatest in the center, and the starting point of the bending is not determined. As a result, in comparative example 410a, there is a possibility that the lid portions 140, 150 and the main body portion 130 may not abut at the desired position. From the hinge structure of comparative example 410a, it is expected that the starting point of the bending will not be determined even if the thickness of hinge 412 is changed.

[0027] Comparative example 420a has a structure in which the base portion of hinge 422 is thick while the central portion is the thinnest (t2) compared to the other examples, and the stress in the central portion is very large, the starting point of bending is concentrated at one point in the central portion, and in fact, if an attempt is made to bend beyond 90°, hinge 422 may break. From the hinge structure of comparative example 420a, it is expected that the thickness of hinge 422 will require reconsideration depending on the molded product.

[0028] In comparative example 430a, the hinge 432 has a curved structure as a whole, which makes it easier for the starting point of bending to be located near the center of the hinge. However, when examining the stress near the base of the hinge 432 when bent 90 degrees, it is clear that the load distribution near the base is different on both sides. This is thought to be due to the fact that the thickness of the hinge 432 is constant throughout its entire length, which causes the load distribution to be inconsistent. As a result, when the hinge 432 is further bent 180 degrees, the load distribution may become uneven and crack from the concentrated area. Furthermore, as described above, the hinge 432 is curved as a whole, and the overall length of the hinge 432 is relatively longer than in the other examples. Therefore, when the hinge 432 is used, there is a possibility that the cover portions 140, 150 may abut at a misaligned position relative to the main body portion 130 when the cover portions 140, 150 are closed relative to the main body portion 130. The hinge structure of comparative example 430a may not have the expected hinge shape after the lid is closed, and the hinge 432 may crack. If a crack occurs, processing using a new mold to match the crack will be required, which is expected to be uneconomical.

[0029] The hinge structure 440a according to the present invention is based on the hinge 110 shown in FIG. 2 . In the present invention, the hinge 110 has a central portion 210 (t0), an outer portion 220 (t1), and a curved portion 215 between the central portion 210 and the outer portion 220. When the hinge structure 440a according to the present invention moves from an extended state to a 90° bent state, bending first begins at the central portion 210 (t0) of the hinge 110. The bending then propagates to the curved portions 215 located on the left and right of the central portion 210, causing bending behavior over a wide range of the entire hinge 110. At a 90° bent state, the hinge structure 440a is in the state shown on the right in FIG. 4 . The hinge 110 according to the present invention can be further bent up to 180° as shown in FIG. 3 . However, in this case, a large load is placed on the outer portion 220 near the base of the hinge 110. In the present invention, unlike the base portion of the hinge of comparative example 420a, outer portion 220 is configured to be slightly thicker than central portion 210 and to have a constant thickness so that it can accommodate bending up to 180° even in situations where the load on outer portion 220, which is the base portion of hinge 110, increases (in the example of hinge structure 440a in Figure 4, the thickness of outer portion 220 is (t1) relative to the thickness (t0) of central portion 210, and it is desirable for t0 / t1 to be approximately 0.8).

[0030] Furthermore, in hinge structure 440a according to the present invention, the total line length of the hinge before bending is set to be similar to the total line length of the hinge after bending it 180 degrees. That is, in FIG. 2 , the upper side (side A) of hinge 110 in FIG. 2 becomes the inside when hinge 110 is bent, and the upper side of hinge 110 has a straight shape. On the other hand, in FIG. 2 , the lower side (side B) of hinge 110 in FIG. 2 becomes the outside when hinge 110 is bent, and the outside (side B) of the hinge has a curved portion due to curved portion 215. Therefore, in the state of FIG. 2 where hinge 110 is not bent, side B, which becomes the outside when hinge 110 is bent, is longer than the total line length of side A, which becomes the inside when hinge 110 is bent. In other words, when the hinge 110 is bent, the outer surface B (the surface on which force is applied in the direction of expansion) is designed to be longer than the inner surface A (the surface on which force is applied in the direction of contraction), resulting in a structure that can reduce the burden on the hinge 110 during the process of bending the hinge 110.

[0031] As described above, in the hinge 110 according to the present invention, the central portion 210 is thinner than the other portions, so that the starting point of bending of the hinge 110 can be set at the central portion 210, and further, the total line length of the outer surface of the hinge 110 is designed to be relatively long, so that the burden on the hinge 110 is reduced when the hinge 110 bends up to 180°.

[0032] It should be noted that increasing the overall length of the hinge 110 can reduce the load on the hinge 110 when the hinge 110 is bent. However, it should be noted that with such a structure, when the lid portions 140, 150 are closed on the main body portion 130, the lid portions 140, 150 may abut at positions that are offset from the main body portion 130. Therefore, in the present invention, by configuring the central portion 210, the curved portion 215, and the outer portion 220 as described above without configuring the overall length of the hinge 110 to be relatively long, when the hinge 110 is bent as shown in FIG. 3 , the load on the hinge 110 can be reduced while the end portions 250 of the lid portions 140, 150 and the end portion 260 of the main body portion 130 abut at desired positions.

[0033] As described above, the hinge of the present invention has a structure that is less likely to crack than conventional hinges, and allows the lid to abut against the main body without causing misalignment. Therefore, the hinge of the present invention reduces the time and labor required for adjustment during the manufacturing stage, making it more economical.

[0034] Furthermore, the hinge of the present invention can provide a hinge that will not break even when the clamp hinge is made of polypropylene (PP). In recent years, polypropylene (PP) has been used as the hinge material for vehicle pipe clamps. However, polypropylene (PP) hinge structures often fail to achieve the desired shape or break during the pipe clamp lid closing operation, and this is particularly likely to occur at temperatures as low as 0°C. The hinge structure of the present invention is applicable to various plastic materials, but is particularly useful when manufactured from polypropylene (PP) and used in low-temperature environments.

[0035] Although one embodiment and example of the hinged clamp according to the present invention have been described above, it is readily understood that the present invention is not limited to the above-described example and that various modifications can be made thereto. Furthermore, as long as these modifications fall within the scope of the claims and their equivalents, they are naturally included within the technical scope of the present invention. While the above-described example is directed to a lid and a body having a predetermined shape, this is merely an example, and the present invention is not limited to this specific example.

[0036] 100 hinged clamp 110, 120 hinge 130 body portion 140, 150 lid portion 210 central portion 215 curved portion 220 outer portion 250, 260 end portions

Claims

1. A clamp in which a first member and a second member are connected by a hinge, and the first member and the second member are configured to abut against each other by bending the hinge, the hinge comprising: outer portions extending from the first member and the second member of the same length and with a constant thickness, a central portion between the outer portions and thinner than the outer portions, and curved portions extending between each of the outer portions and the central portion, the shape of the curved portions that become outer when the hinge is bent being curved such that the thickness of the curved portions gradually decreases from the outer portions toward the central portion when the hinge is extended, and the shape of the hinge that becomes inner when the hinge is bent being a straight shape from the first member to the second member when the hinge is extended.

2. The clamp of claim 1, wherein said hinge is formed of polypropylene.

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