Fastening structure

Abstract

The fastening structure of the present disclosure includes: a first member having a through hole; a second member; and a fastener that is inserted through the through hole and fastens the first member and the second member together, in the fastening structure, the rigidity of a portion of the first member around the through hole is lower than the rigidity of a portion of the second member fastened by the fastener.

Description

Technical Field

[0001] The present disclosure relates to a fastening structure for fastening a plurality of components together by a fastener such as a bolt. Background Art

[0002] Figure 7 is a perspective view showing an outline of a structure in which a compressor 103 is mounted on an engine 101, Figure 8 is a side view thereof, Figure 9 is a front view thereof. A hanger 102 for suspension is mounted on the engine 101. A bracket 104 is mounted on the compressor 103, and the bracket 104 is fastened to the side surface of the hanger 102 by a bolt 105. It should be noted that details of other fastening portions for mounting the compressor 103 to the engine 101 are not shown. Summary of the Invention

[0003] Problems to be Solved by the Invention

[0004] As the vehicle runs repeatedly, that is, as the engine is repeatedly used, wear called fretting sometimes occurs on the contact surface between the bracket 104 and the hanger 102. Fretting is wear caused by mutual friction of components.

[0005] In order to prevent fretting, the following measures can be considered: (1) increasing the number of fasteners to increase the surface pressure between components; (2) increasing the tightening torque of the fasteners to increase the surface pressure between components; (3) forming a wear-preventing protective layer on the fastening surface of the components; (4) applying a wear-preventing lubricant to the fastening surface of the components. However, no matter which measure is adopted, the cost related to fastening will increase. In addition, depending on the shape and material of the components, etc., these measures may sometimes not be feasible.

[0006] Regarding a fastening structure formed by fastening a plurality of components together by a fastener, the inventors of the present disclosure have found through research that the main causes of fretting in this structure are as follows.

[0007] Figure 10 is a diagram schematically showing a cross section of the fastening structure. Through holes 62 and 72 are respectively formed in a first component 61 and a second component 71, and the first component 61 and the second component 71 are fastened together by a bolt 81 and a nut 82 inserted through the two through holes 62 and 72.

[0008] Even if it is designed such that the opposing surfaces of the first component 61 and the second component 71 are in surface contact with each other, due to manufacturing errors and assembly errors of the first component 61 and the second component 71 respectively, etc., as Figure 10As in the example shown, even though the bolt is tightened firmly, the abutting surfaces of the first member 61 and the second member 71 do not come into surface contact. Only the abutting portions 63 and 73 of a part of the first member 61 and the second member 71 abut, and a gap G is formed in the remaining portions.

[0009] When the first member 61 and the second member 71 are in a vibrating environment in this tightened state, the abutting portions 63 and 73 are not likely to move relative to each other. In contrast, the portions 64 and 74 separated by the gap G are likely to move relative to each other. When the two portions 64 and 74 move relative to each other, the two portions 64 and 74 will come into contact with each other and generate friction, thereby causing fretting wear.

[0010] An object of the present disclosure is to provide a fastening structure that fastens a plurality of members together by a fastener and does not cause fretting wear.

[0011] Solution to the problem

[0012] The fastening structure of the present disclosure includes: a first member having a through hole; a second member; and a fastener that is inserted through the through hole and fastens the first member and the second member together. In this fastening structure, the rigidity of the portion around the through hole in the first member is lower than the rigidity of the portion fastened by the fastener in the second member.

[0013] Advantageous effects of the invention

[0014] According to the present disclosure, the members fastened by the fastener are deformed under the action of the fastening force of the fastener, so that the fastened members come into surface contact with each other, and thus the generation of fretting wear can be suppressed. Description of the drawings

[0015] Figure 1 It is a view showing the fastening state of the first member and the second member.

[0016] Figure 2 It is a sectional view of the first member.

[0017] Figure 3 It is a view showing a first modification.

[0018] Figure 4 It is a view showing a second modification.

[0019] Figure 5 It is a sectional view of the bracket.

[0020] Figure 6 It is a view showing the fastening state of the bracket and the hanger.

[0021] Figure 7 It is a view showing a state where a compressor is mounted on an engine.

[0022] Figure 8 is Figure 7 a side view of

[0023] Figure 9 is Figure 7 a front view of

[0024] Figure 10 a figure showing the prior art

[0025] Description of reference numerals

[0026] 1: First component;

[0027] 2: Through-hole;

[0028] 3: Large-diameter part;

[0029] 4: Small-diameter part;

[0030] 6: Contact part;

[0031] 7: Thin-wall part;

[0032] 11: Second component;

[0033] 12: Through-hole;

[0034] 16: Contact part;

[0035] 21: Bolt;

[0036] 22: Nut. Detailed implementation manners

[0037] Next, a fastening structure of an embodiment of the present disclosure will be specifically described with reference to the drawings. It should be noted that the embodiments described below are all comprehensive or specific examples. In addition, each figure is a schematic diagram and is not necessarily a strictly drawn figure. Further, in each figure, substantially the same components are labeled with the same reference numerals, and repeated descriptions may be omitted or simplified.

[0038] Figure 1 schematically shows a structure in which a first component 1 and a second component 11 of the present embodiment are fastened together by a bolt 21 and a nut 22 as a kind of fastener. Figure 1 The upper half of Figure 1 shows the state before fastening the bolt (a state of being loosely tightened), Figure 2 and the lower half of

[0039] Through holes 2 and 12 are respectively formed in the first member 1 and the second member 11, and a bolt 21 is inserted through the through holes 2 and 12. The opposing surfaces of the first member 1 and the second member 11 are not parallel to each other. Around the through holes 2 and 12, the abutting portion 6 in the first member 1 abuts against the abutting portion 16 in the second member 11, and a gap G is provided in the remaining portion.

[0040] In the through hole 2 of the first member 1, the side closer to the second member 11 (the right side in the figure) is a large-diameter portion 3, and the side farther from the second member 11 (the left side in the figure) is a small-diameter portion 4. Thus, in the portion around the through hole 2 in the first member 1, the portion opposite to the second member 11 is a thin-wall portion 7. Therefore, the rigidity of the portion around the through hole 2 in the first member 1 is lower than the rigidity of the second member 11.

[0041] As Figure 1 shown in the lower half of [], when the bolt 21 and the nut 22 are tightened tightly, the thin-wall portion 7 of the first member 1 deforms under the action of the tightening force, so that the first member 1 and the second member 11 are in surface contact around the through holes 2 and 12. Through the surface contact between the first member 1 and the second member 11, the frictional force between the first member 1 and the second member 11 will increase. Even when the first member 1 and the second member 11 are in a vibrating environment, the first member 1 and the second member 11 will not move relative to each other, thereby being able to suppress the generation of fretting wear.

[0042] Figure 3 shows a first modification example of the first member 1. In this modification example, it is assumed that the portion around the through hole 2 of the first member 1 is a thin-wall portion 7, thereby replacing the formation of a large-diameter portion and a small-diameter portion in the through hole 2 ( Figure 3 the upper half of []). Thus, when the bolt 21 and the nut 22 are tightened tightly, the thin-wall portion 7 of the first member 1 deforms under the action of the tightening force, so that the first member 1 and the second member 11 are in surface contact around the through holes 2 and 12 ( Figure 3 the lower half of []).

[0043] Figure 4 shows a second modification example of the first member 1. In this modification example, the wall thickness of the portion around the through hole 2 of the first member 1 is the same as that in the example of the prior art ( Figure 10 ), but a material with low rigidity, such as aluminum alloy, etc., is used as the material of the first member 1 ( Figure 4 the upper half of []). Thus, when the bolt 21 and the nut 22 are tightened tightly, the second member 11 will not deform. In contrast, the first member 1 deforms under the action of the tightening force, so that the first member 1 and the second member 11 are in surface contact around the through holes 2 and 12 ( Figure 4 the lower half of []).

[0044] Figure 5It is a cross-sectional view of the fastening portion of the bracket 31 that is installed on the compressor, and the bracket 31 is used to mount the compressor on the engine. A through hole 32 is formed in the bracket 31, and a large-diameter portion 33 and a small-diameter portion 34 are formed in the through hole 32. Moreover, a thin-wall portion 37 is formed in the portion around the large-diameter portion 33.

[0045] The inner diameters of the large-diameter portion 33 and the small-diameter portion 34 and the outer diameter of the thin-wall portion 37 are designed based on the material of the bracket 31 and the like. For example, when the material of the bracket 31 is FC250 cast iron according to Japanese Industrial Standard JIS, preferably, the inner diameter of the large-diameter portion 33 is 15 mm, the inner diameter of the small-diameter portion 34 is 11.8 mm, the outer diameter of the thin-wall portion 37 is 22 mm, and the thickness of the thin-wall portion 37 is 3.5 mm.

[0046] Figure 6 It is a cross-sectional view of a structure in which the bracket 31 (the first component) and a hanger 41 (the second component) for suspending an engine (not shown) are fastened together by a bolt 51. An internal thread 42 that engages with the bolt 51 is formed in the hanger 41. When the bracket 31 and the hanger 41 are fastened together by the bolt 51, the thin-wall portion 37 around the through hole 32 deforms under the action of the fastening force, so that the bracket 31 and the hanger 41 are in surface contact. Thereby, it is possible to suppress fretting wear from occurring at the contact surface between the bracket 31 and the hanger 41.

[0047] As described above, according to the present disclosure, the components fastened by the fastener deform under the action of the fastening force of the fastener, so that the fastened components are in surface contact with each other, and thus it is possible to suppress the occurrence of fretting wear.

[0048] Industrial Applicability

[0049] The fastening structure of the present disclosure is suitable for applications where a plurality of components are fastened together by a fastener.

Claims

1. A fastening structure, comprising: A first component having a through-hole; A second component; And A fastener inserted through the through-hole to fasten the first component and the second component together, The fastening structure is characterized in that The rigidity of the portion around the through-hole in the first component is lower than the rigidity of the portion in the second component that is fastened by the fastener.

2. The fastening structure according to claim 1, wherein The second component is provided with a through-hole, The fastener is inserted through the through-holes of the first component and the second component respectively.

3. The fastening structure according to claim 1 or 2, wherein The first component is a bracket for mounting a compressor to an engine, The second component is a hanger for suspending the engine.

4. The fastening structure according to claim 1 or 2, wherein The portion around the through-hole in the first component is formed as a thin-walled portion.

5. The fastening structure according to claim 1 or 2, wherein In the through-hole, the side close to the second component is formed as a large-diameter portion, and the side far from the second component is formed as a small-diameter portion, so that the portion around the through-hole in the first component is formed as a thin-walled portion.

6. The fastening structure according to claim 1 or 2, wherein The rigidity of the material of the portion around the through-hole in the first component is lower than the rigidity of the material of the portion in the second component that is fastened by the fastener.

7. A fastening structure, comprising A first component having a through-hole; A second component; And A fastener inserted through the through-hole to fasten the first component and the second component together, The fastening structure is characterized in that The first component and the second component are in surface contact by deformation of at least one of the first component and the second component under the action of the fastening force of the fastener.

8. The fastening structure according to claim 7, wherein The first component is a bracket for mounting a compressor to an engine, The second component is a hanger for suspending the engine.

9. The fastening structure according to claim 7, wherein The portion around the through-hole in the first component is formed as a thin-walled portion.

10. The fastening structure according to claim 7, wherein In the through-hole, the side close to the second component is formed as a large-diameter portion, and the side far from the second component is formed as a small-diameter portion, so that the portion around the through-hole in the first component is formed as a thin-walled portion.

11. The fastening structure according to claim 7, wherein The rigidity of the material of the portion around the through-hole in the first component is lower than the rigidity of the material of the portion in the second component that is fastened by the fastener.

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