Contracted materials

Abstract

To provide a technology for suppressing creep deformation while reducing costs in fastened members fastened with screw members. A fastened member (10) fixed to a vehicle body member (16) comprises a base (20) having a reference surface that receives the seating surface of a screw member (14), an insertion hole formed in the base (20) for inserting the screw member (14), and a deformation portion formed on the reference surface. When the screw member (14) is fastened, the deformation portion and the base (20) are sandwiched between the vehicle body member (16) and the seating surface, and undergo plastic and elastic deformation.

Description

[Technical Field]

[0001] The present invention relates to a fastened member that is fastened to a vehicle body member by a screw member. [Background technology]

[0002] Patent Document 1 discloses that a fiber-reinforced composite material formed in layers of thermosetting resin and carbon fiber is fastened to a metal material with a bolt. The fiber-reinforced composite material has a fastening through-hole for inserting the bolt and an iron coating layer on the inner periphery of the through-hole. The iron coating layer is formed by adhering powder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-253697 Summary of the Invention [Problem to be solved by the invention]

[0004] The fiber reinforced composite material disclosed in Patent Document 1 is costly because iron must be attached to the through-holes for fastening, and a separate material must be prepared from the base material, and then a process for attaching the iron is performed.

[0005] An object of the present invention is to provide a technique for suppressing creep deformation while reducing costs in fastened members fastened with screw members. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present invention is a fastened member fixed to a vehicle body member, the fastened member comprising: a base portion having a reference surface that receives the seating surface of a screw member; an insertion hole portion formed in the base portion for inserting the screw member; and a deforming portion formed on the reference surface. When the screw member is fastened, the deforming portion and the base portion are sandwiched between the vehicle body member and the seating surface and undergo plastic and elastic deformation. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique for suppressing creep deformation while reducing costs in fastened members fastened with screw members. [Brief explanation of the drawings]

[0008] [Figure 1] 10A and 10B are diagrams showing a fastened member fixed to a vehicle body member by a screw member according to an embodiment of the present invention; [Figure 2] 2(A) is a top view of the workpiece 10, and FIG. 2(B) is a cross-sectional view of the base 20 taken along line AA in FIG. 2(A). [Figure 3] 10A and 10B are diagrams for explaining fastening of the base portion by a screw member. [Figure 4] FIG. 4 is a cross-sectional view of the fastened members in a fastening completed state. [Figure 5] FIG. 10 is a plan view of a modified example of fastened members. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1 is a diagram showing a fastened member 10 fixed to a vehicle body member 16 by a screw member 14 of the embodiment. The fastened member 10 includes a base 20, a case 22, and an extension 24, which are integrally molded from the same resin material.

[0010] The case 22 accommodates and holds the electronic component 12. The electronic component 12 may be an electronic circuit board such as an in-vehicle ECU (electronic control unit). The electronic circuit board may be arranged vertically or horizontally. In other words, the fastened member 10 functions as a component holder that holds the electronic component 12.

[0011] The extension portion 24 is formed in a columnar shape and extends from the case 22. The base portion 20 is fixed to the vehicle body member 16 by the screw member 14. When fastened, the base portion 20 is sandwiched between the screw member 14 and the vehicle body member 16, and is pressed against the vehicle body member 16 by the axial force of the screw member 14. The base portion 20 has an insertion hole portion 26 into which the screw member 14 can be inserted. A plurality of base portions 20 and extension portions 24 are provided for the case 22.

[0012] The vehicle body member 16 is, for example, a vehicle body panel, a vehicle body frame, or a metal bracket fixed to the vehicle body frame, and in any case is a member that constitutes the vehicle body. The vehicle body member 16 has a screw hole portion 16a that constitutes a female screw. The screw member 14 fastens the base portion 20 to the vehicle body member 16. The screw member 14 is, for example, a bolt.

[0013] The case 22 is positioned away from the surface of the vehicle body member 16. The shape, length, and angle of the extension 24 relative to the case 22 can be set according to the mounting position of the electronic component 12, and are not limited to the form shown in FIG. 1. In any case, the extension 24 extends toward the vehicle body member 16 to which it is to be mounted. The base 20 is connected to the extension 24.

[0014] Fig. 2(A) is a top view showing a part of the workpiece 10, and Fig. 2(B) is a cross-sectional view of the base 20 taken along line AA in Fig. 2(A). The base 20 has an insertion hole 26, a reference surface 28, and a protrusion 30.

[0015] The insertion hole 26 is formed through the center of the base 20, and the threaded portion of the screw member 14 can be inserted therein. The central axis direction of the insertion hole 26 is simply referred to as the axial direction. The central axis direction of the insertion hole 26 is substantially the same as the axial direction of the screw member 14 in the attached state. The circumferential direction is the direction that is perpendicular to the axial direction and rotates around the axis. The radial direction is the direction that is perpendicular to the axial direction and extends radially.

[0016] The reference surface 28 is a flat surface of the base 20. The protrusions 30 are formed to protrude from the reference surface 28. A plurality of the protrusions 30 are formed spaced apart in the circumferential direction. By providing the protrusions 30 at intervals, they can be crushed more easily than if they were formed in an annular shape.

[0017] The protrusions 30 are formed so that their radial width is longer than their circumferential width. Alternatively, the plurality of protrusions 30 may include a protrusion 30 formed so that its radial width is longer than its circumferential width. The protrusions 30 are formed elongated along the radial direction. This allows the protrusions 30 to extend radially, which generates stress on both the inner diameter side and the outer diameter side during fastening, reducing stress bias.

[0018] The protrusions 30 are formed in a fan shape whose circumferential width increases along the radially outward direction. The multiple protrusions 30 may include protrusions 30 formed in a fan shape whose circumferential width increases along the radially outward direction. Since the circumferential width differs between the inner diameter side and the outer diameter side, the stress generated during fastening can be set to decrease from the inner diameter side toward the outer diameter side. This makes it possible to suppress creep deformation toward the outer diameter side, maintain the fastening force on the outer diameter side where the contact surface increases, and suppress rattle over time.

[0019] The multiple protrusions 30 are positioned away from the edge of the insertion hole 26. This prevents some of the multiple protrusions 30 from being crushed radially inward during fastening, causing the screw member 14 to tilt.

[0020] The plurality of protrusions 30 are disposed closer to the inner circumferential edge of the base 20 than to the outer circumferential edge. The plurality of protrusions 30 are formed flat. The plurality of protrusions 30 may be formed with a curved surface, for example, in a hemispherical or hemispherical shape. The plurality of protrusions 30 may be spaced apart not only in the circumferential direction but also in the radial direction.

[0021] Fig. 3 is a diagram for explaining fastening of the base 20 by the screw member 14. Fig. 3(A) shows the base 20 in a state before fastening, and Fig. 3(B) shows the base 20 in a state after fastening is completed. Figs. 3(A) and 3(B) are cross-sectional views of the base 20 shown in Fig. 2(A) taken along line AA.

[0022] The screw member 14 has a head 32, a bearing surface 34, a cylindrical portion 36, and a threaded portion 38. The bearing surface 34 is located on the back surface of the head 32. The cylindrical portion 36 is located closer to the head 32 than the threaded portion 38 and hangs down from the back surface of the head 32. The threaded portion 38 forms a male screw. When the head 32 is rotated by a tool, the threaded portion 38 advances and retreats relative to the screw hole portion 16a.

[0023] 3(A), with the base 20 placed on the vehicle body member 16, the insertion hole 26 is aligned with the screw hole 16a of the vehicle body member 16, and the screw member 14 is inserted into the insertion hole 26. The insertion hole 26 has a larger diameter than the cylindrical portion 36 and the screw portion 38.

[0024] 3(B), the screw portion 38 is threaded into the screw hole 16a, and the seating surface 34 presses against the protruding portion 30. The protruding portion 30 is deformed so as to be crushed, and the reference surface 28 receives the seating surface 34. The screw member 14 is screwed in until it reaches the reference surface 28, deforming the protruding portion 30 and its surrounding area.

[0025] The protrusion 30 constitutes a deformation portion that is deformed when pressed against the seat surface 34 during fastening. The protrusion 30, which is a deformation portion, undergoes at least plastic deformation, and may partially undergo elastic deformation.

[0026] As shown in Figure 3(B), a protrusion 30 remains protruding from the head 32. The multiple protrusions 30 include a protrusion 30 formed to protrude radially outward from the seating surface 34. In other words, the protrusion 30 extends radially outward beyond the seating surface 34, and is formed at a position where it protrudes radially outward from the seating surface 34. This allows the worker to visually check the degree of crushing of the protrusion 30, making it easier to check the degree of tightening of the screw member 14.

[0027] Figure 4 is a cross-sectional view of the workpieces 10 in a fastened state. Figure 4(A) shows a cross-section of the base 20 taken along line AA in Figure 2(A), and Figure 4(B) shows a cross-section of the base 20 taken along line BB in Figure 2(A). That is, Figure 4(A) shows a cross-section of a portion where the protrusion 30 is provided, and Figure 4(B) shows a cross-section of a portion where the protrusion 30 is not provided.

[0028] As shown in FIG. 4(A), the protrusion 30 and a portion of the base 20 located on the back side of the protrusion 30 are pressed by the seating surface 34 and deform together to form a first deformation region 40. The first deformation region 40 is the portion pressed by the seating surface 34, and refers to the protrusion 30 and a region of the base 20 that overlaps with the protrusion 30 in the axial direction. As shown in FIG. 4(B), the base 20 without the protrusion 30 is pressed against the reference surface 28 by the seating surface 34 to form a second deformation region 42. The second deformation region 42 refers to a region of the base 20 that overlaps with the seating surface 34 but does not overlap with the protrusion 30.

[0029] The first deformation region 40 is longer in the axial direction by the height of the protrusion 30 than the second deformation region 42, and therefore experiences a greater stress. Therefore, the first deformation region 40 undergoes plastic and elastic deformation. The first deformation region 40 does not undergo plastic deformation only at the protrusion 30; rather, the entire first deformation region 40 is compressed, and although it may be difficult to distinguish the boundary between plastic deformation and elastic deformation, a larger volume fraction of the first deformation region 40 undergoes plastic deformation than the second deformation region 42. The second deformation region 42 undergoes elastic deformation and may also undergo plastic deformation depending on the axial force of the screw member 14.

[0030] Since the multiple protrusions 30 are spaced apart in the circumferential direction, the first deformation region 40, where stress is large, and the second deformation region 42, where stress is small, are located separately in the circumferential direction. Stress applied to the first deformation region 40 can be released to the second deformation region 42, and the occurrence of creep in the first deformation region 40 can be suppressed.

[0031] Fig. 5 is a plan view of a modified fastened member 100. The modified fastened member 100 differs from the fastened member 10 shown in Fig. 2(A) in the arrangement of the multiple protrusions 130.

[0032] The reference surface 28 has a first region 28a and a second region 28b, each of which is divided into half by a straight line passing through the central axis. The first region 28a is located closer to the extending portion 24 than the second region 28b. The first region 28a is located closer to the extending portion 24 than the second region 28b, and is continuous with the extending portion 24 in a top view. The second region 28b may be arranged so as not to be continuous with the extending portion 24 in a top view. The first region 28a may be closer to the case 22 than the second region 28b.

[0033] The first region 28a, which is closer to the extending portion 24, receives a load from the case 22 via the extending portion 24. Therefore, the first deformation region 40 formed in the first region 28a may be subjected to excessive stress. Therefore, the multiple protrusions 130 are arranged more on the second region 28b than on the first region 28a. This makes it possible to prevent creep deformation of the first deformation region 40 located on the extending portion 24 side.

[0034] 5 shows an embodiment in which the plurality of protrusions 30 are arranged over half the circumference and are arranged so as to avoid the first region 28a, but this is not limiting. The plurality of protrusions 30 may be arranged by the load applied from the extension portion 24, and may be arranged, for example, excluding a rotation angle of 90 degrees or 120 degrees instead of half the circumference.

[0035] The present disclosure has been described above based on examples. The present disclosure is not limited to the above examples, and various modifications such as design changes may be made based on the knowledge of those skilled in the art.

[0036] For example, the fastened member 10 may be integrally formed by the base portion 20 and the extension portion 24 and connected to a separate member such as a case 22. [Explanation of symbols]

[0037] 10 fastened member, 12 electronic component, 14 screw member, 16 vehicle body member, 16a screw hole portion, 20 base portion, 22 case, 24 extension portion, 26 insertion hole portion, 28 reference surface, 28a first region, 28b second region, 30 protrusion portion, 32 head portion, 34 seat surface, 36 cylindrical portion, 38 screw portion, 40 first deformation region, 42 second deformation region.

Claims

1. A fastened member fixed to a vehicle body side member, a base portion having a reference surface that receives a seating surface of the screw member; an insertion hole formed in the base portion for inserting the screw member; a deformation portion formed on the reference surface, The fastened member is characterized in that the deformation portion and the base portion are sandwiched between the vehicle body member and the seat surface and are plastically and elastically deformed when fastened by the screw member.

2. The fastened workpieces according to claim 1 , wherein the deformed portion is a protruding portion formed to protrude from the reference surface.

3. The fastened workpieces according to claim 2 , wherein the protrusions are formed in a plurality of positions spaced apart from one another in the circumferential direction.

4. 4. The fastened workpiece according to claim 3, wherein the plurality of protrusions include a protrusion formed to protrude radially outward from the seating surface.

5. 5. The fastened workpieces according to claim 3, wherein the plurality of protrusions include a protrusion formed so that its radial width is longer than its circumferential width.

6. 5. The fastened members according to claim 3, wherein the plurality of protrusions include a protrusion formed in a fan shape whose circumferential width increases radially outward.

7. 5. The fastened workpiece according to claim 3, wherein the plurality of protrusions are positioned away from the edge of the insertion hole.

8. a case for supporting electronic components; an extension extending from the case and connecting to the base, the reference surface having a first region and a second region divided in half; the first region is located closer to the extension portion than the second region, The fastened members according to claim 3 or 4, wherein the number of the plurality of protrusions arranged in the first region is smaller than that in the second region.

Images