Strut mount

Abstract

To provide a strut mount that makes it easier to ensure the joint strength between the first member and the second member. [Solution] Multiple circular through holes 24 penetrating in the direction of axis C are provided at multiple locations in the circumferential direction of the annular first flange 22 of the first member 20. Multiple ribs 35 protruding from the annular second flange 33 of the second member 30 are inserted into these multiple through holes 24. The ribs 35 have an annular cross-section perpendicular to the direction of axis C, and the tip of the rib 35 is widened in diameter, thereby crimping and fixing the first member 20 and the second member 30 together. Thus, it is easier to ensure the joint strength between the first member 20 and the second member 30.

Description

Technical Field

[0001] The present invention relates to a strut mount in which a first member and a second member sandwiching a vibration isolation base are joined to each other, and more particularly to a strut mount that can easily ensure the joining strength between the first member and the second member.

Background Art

[0002] Regarding a suspension mechanism in a vehicle such as an automobile, a strut mount is interposed between the vehicle body and the piston rod of a shock absorber. Some strut mounts have a first member and a second member attached to the vehicle body side, which sandwich an elastic vibration isolation base up and down. In the strut mount described in Patent Document 1, a plate-like claw protrudes downward from the flange portion of the upper first member, and the claw is bent radially inward (in the plate thickness direction of the claw) and applied to the lower second member, thereby caulking and fixing (joining) the first member and the second member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the joining method described in Patent Document 1, there is a problem that the claw is relatively easily bent radially outward (in the plate thickness direction of the claw), and it is difficult to ensure the joining strength between the first member and the second member.

[0005] The present invention has been made to solve the above-described problems, and an object thereof is to provide a strut mount that can easily ensure the joining strength between the first member and the second member.

Means for Solving the Problems

[0006] To achieve this objective, the strut mount of the present invention is interposed between the vehicle body and the piston rod of a shock absorber and comprises: an inner member attached to the tip of the piston rod; an annular vibration-damping base made of an elastic material attached to the inner member so as to surround the axis of the piston rod; and a first member and a second member attached to the vehicle body and sandwiching the vibration-damping base in the axial direction. The first member comprises a first flange formed in an annular shape that protrudes radially outward from the vibration-damping base, and multiple circular through holes that penetrate in the axial direction are provided at multiple locations in the circumferential direction of the first flange. The second member comprises an annular second flange that is superimposed on the first flange in the axial direction, and a plurality of ribs that protrude from the second flange and are inserted into each of the plurality of through holes, and whose cross-section perpendicular to the axial direction is formed in an annular shape. The first member and the second member are crimped and fixed together by expanding the diameter of the tips of the ribs inserted into the through holes. [Effects of the Invention]

[0007] According to the strut mount described in claim 1, multiple circular through-holes penetrating in the axial direction are provided at multiple locations in the circumferential direction of the annular first flange of the first member. Multiple ribs protruding from the annular second flange of the second member are inserted into these multiple through-holes. The ribs have an annular cross-section perpendicular to the axial direction, and the first member and the second member are crimped together by expanding the diameter of the tip of the rib. If the diameter of the tip of the rib is reduced, the crimping is released, but compared to the case of simply bending a plate-shaped claw in the thickness direction as in the conventional technology, a large force is required to reduce the diameter of the rib. Therefore, crimping with ribs makes it easier to ensure the joint strength between the first member and the second member.

[0008] The strut mount described in claim 2 provides the following effects in addition to those of the strut mount described in claim 1. The first flange has a first outer surface on the opposite side of the axial direction from the second flange. The inner circumferential surface of the through hole has an enlarged hole portion at the connection point with the first outer surface, which widens towards the first outer surface. The tip of the enlarged rib contacts the enlarged hole portion, thereby crimping and fixing the first member and the second member, with the rib positioned on the second flange side of the first outer surface. In this way, since the rib for crimping does not protrude from the first outer surface, the first outer surface around the through hole can be easily brought into close contact with other members (e.g., the vehicle body, bolts, nuts, etc.).

[0009] The strut mount described in claim 3 provides the following effects in addition to those of the strut mount described in claim 1 or 2. The strut mount comprises a plurality of bolts for fastening the first member and the second member to the vehicle body. These bolts are inserted into a plurality of mounting holes that penetrate the first flange and the second flange in the thickness direction. The heads of the bolts overlap the first outer surface of the first flange on the side opposite to the second flange in the axial direction, and the shafts of the bolts protrude from the second outer surface of the second flange on the side opposite to the first flange in the axial direction. Therefore, when fastening the first member and the second member to the vehicle body with bolts, the second outer surface of the portion where the mounting holes are opened overlaps the vehicle body. The second outer surface is formed in the same plane as the portion where the mounting holes are opened and the portion located on the opposite side of the rib in the axial direction (near the rib). As a result, the second outer surface near the rib may also overlap the vehicle body.

[0010] In this case, if the first flange is positioned to overlap the vehicle body instead of the second flange, the vehicle body may overlap the first outer surface around the through-hole into which the rib is inserted. If the tip of the rib in this through-hole protrudes from the first outer surface, the tip of the rib may cause the first outer surface to lift away from the vehicle body, potentially leading to problems with fastening the first and second components to the vehicle body. In contrast, this strut mount is configured so that the second outer surface, opposite to the tip of the rib, overlaps with the vehicle body, rather than the first outer surface where the tip of the rib may protrude. Therefore, it is possible to prevent the second outer surface from lifting away from the vehicle body due to the tip of the rib, which could cause problems with fastening.

[0011] The strut mount described in claim 4 provides the following effects in addition to those of the strut mount described in claim 1 or 2. Here, in order to crimp and fix the first member and the second member, for example, the tip of a cylindrical rib is inserted into a through hole, and the tip of the rib is expanded in diameter by press working. Specifically, in press working, the tip of the rib is expanded in diameter by inserting a pin of a press die into the rib hole, which is a hole on the inner circumference side of the rib, and pressing the tapered portion provided on the base end of the pin against the tip of the rib. Since the rib hole opens on the second outer surface of the second flange, which is on the opposite side of the axial direction from the first flange (opposite the tip of the pin), for example, the pin can be made to protrude from the second outer surface during press working, and the degree of freedom of the pin height can be ensured. Thus, the degree of freedom of the method of expanding the diameter of the rib and crimping it can be ensured.

[0012] The strut mount according to claim 5 provides the following effects in addition to those of the strut mount according to claim 4. The strut mount includes a plurality of bolts for fastening the first member and the second member to the vehicle body. These plurality of bolts are inserted into two or more of the plurality of rib holes. By using the rib holes formed by the ribs for crimping as mounting holes into which the bolts for fastening to the vehicle body are inserted, the number of holes to be drilled in the first flange and the second flange can be reduced compared to when they are provided separately. As a result, costs such as drilling holes in the first flange and the second flange can be reduced. [Brief explanation of the drawing]

[0013] [Figure 1] This is a top view of the strut mount in the first embodiment. [Figure 2] This is a cross-sectional view of the strut mount along line II-II in Figure 1. [Figure 3] This is a schematic diagram illustrating a method for manufacturing a strut mount. [Figure 4] This is a top view of the strut mount in the second embodiment. [Figure 5] Figure 4 is a cross-sectional view of the strut mount along the VV line. [Modes for carrying out the invention]

[0014] Preferred embodiments will be described below with reference to the attached drawings. Figure 1 is a top view of the strut mount 10 in the first embodiment. Figure 2 is a cross-sectional view of the strut mount 10 along the line II-II in Figure 1. Figure 2 shows the strut mount 10 mounted on a vehicle.

[0015] The strut mount 10 is a vibration damping device in the vehicle's suspension mechanism that reduces vibrations transmitted from the wheel side to the vehicle body side. The strut mount 10 is interposed between the bracket 2 of the vehicle body and the piston rod 4 of the shock absorber.

[0016] More specifically, the strut mount 10 comprises a cylindrical inner member 11 attached to the tip (upper end) of the piston rod 4, an outer member 12 attached to the bracket 2, and a vibration-damping base 13 connecting the inner member 11 and the outer member 12. The axis C of the inner member 11 coincides with the axis C of the piston rod 4. In the following description, the direction parallel to axis C is referred to as the axis C direction, the radial direction perpendicular to axis C is simply abbreviated as the radial direction, and the circumferential direction around axis C is simply abbreviated as the circumferential direction.

[0017] The inner member 11 is a member made of metal such as steel or aluminum alloy. The inner member 11 includes a cylindrical main body portion 11a centered on the axis C, and an annular plate portion 11b that projects radially outward from the upper end of the main body portion 11a. The plate portion 11b is a flat plate perpendicular to the axis C. The inner member 11 is attached to the piston rod 4 by inserting and fastening the tip of the piston rod 4 on the inner peripheral side of the main body portion 11a.

[0018] The vibration isolation base 13 is an annular member made of an elastic body that covers the upper surface, lower surface, and outer peripheral surface of the plate portion 11b. In this embodiment, the elastic body is rubber, but the elastic body may be composed of a thermoplastic elastomer, a foamed synthetic resin, or the like. The vibration isolation base 13 is vulcanized and adhered to the plate portion 11b.

[0019] The outer member 12 is a member made of metal such as steel or aluminum alloy. The outer member 12 is fastened to the bracket 2 of the vehicle body by bolts 14 and nuts 15. The outer member 12 includes a first member 20 and a second member 30 that sandwich the vibration isolation base 13 in the direction of the axis C. The first member 20 is provided below the vibration isolation base 13, and the second member 30 is provided above the vibration isolation base 13.

[0020] The first member 20 is a flat plate perpendicular to the axis C and is formed in a substantially rhombic shape in a top view. The first member 20 includes a first clamping portion 21 that supports the vibration isolation base 13 from below, and a first flange 22 that projects radially outward from the outer peripheral edge of the first clamping portion 21. The first clamping portion 21 and the first flange 22 are integrally formed.

[0021] The first clamping portion 21 is an annular plate-shaped portion provided with a circular hole 21a penetrating in the direction of the axis C at the radial center. The main body portion 11a of the inner member 11 and the piston rod 4 are inserted through the inside of the hole 21a. Also, a spring seat 6 is caulked and fixed inside the hole 21a.

[0022] The first flange 22 is an annular portion that extends radially outward from the entire circumference of the outer edge of the first clamping portion 21, that is, an annular portion that extends radially outward from the vibration-damping base 13. The first flange 22 comprises a first inner surface 22a, which is the upper surface on the second member 30 side, and a first outer surface 22b, which is the lower surface on the opposite side of the axis C from the second member 30 and the first inner surface 22a. The first flange 22 is provided with circular mounting holes 23 and through holes 24 that penetrate in the axis C direction, opening into the first inner surface 22a and the first outer surface 22b, respectively.

[0023] Mounting holes 23 are provided at two locations near the interior angles of less than 90 degrees in the roughly diamond shape. Bolts 14 for fastening to the bracket 2 are inserted into the mounting holes 23. The head 14a of the bolt 14 is superimposed on the first outer surface 22b. A press-fit portion 14c is provided on the head 14a side (base end side) of the shaft portion 14b of the bolt 14, which is press-fitted into the mounting hole 23.

[0024] The through holes 24 are provided at six equally spaced locations in the circumferential direction of the first flange 22. Two of the six are located between the mounting holes 23 and the axis C. The inner circumferential surface of the through holes 24 has an enlarged diameter section 25 at the connection point with the first outer surface 22b, which tapers in diameter toward the first outer surface 22b. That is, the enlarged diameter section 25 is a portion formed by chamfering the edges between the inner circumferential surface of the through hole 24 and the first outer surface 22b. The inner circumferential surface of the through holes 24, excluding the enlarged diameter section 25, has a uniform inner diameter along the axis C.

[0025] The second member 30 is formed in a substantially rhomboid shape when viewed from above, similar to the first member 20. The second member 30 includes a second clamping portion 31 that clamps the vibration-damping base 13 in the axial direction C between itself and the first clamping portion 21, a cylindrical portion 32 extending downward from the outer peripheral edge of the second clamping portion 31, a second flange 33 protruding radially outward from the lower end of the cylindrical portion 32, and a plurality of ribs 35 protruding from the second flange 33. These second clamping portion 31, cylindrical portion 32, second flange 33, and ribs 35 are integrally formed by press-forming a single sheet of material.

[0026] The second clamping portion 31 is an annular plate-shaped part with a circular hole 31a that penetrates in the direction of axis C, located in the radial center. This hole 31a exposes the inner member 11 and the piston rod 4 when viewed from above. The cylindrical portion 32 is a cylindrical part that contacts the outer circumferential surface of the vibration-damping base 13 around its entire circumference. Thus, the vibration-damping base 13 is housed in the cup-shaped portion formed by the second clamping portion 31 and the cylindrical portion 32.

[0027] The second flange 33 is an annular portion that protrudes radially outward from the entire circumference of the lower end of the cylindrical portion 32, that is, an annular portion that protrudes radially outward from the vibration-damping base 13. The second flange 33 is superimposed on the first flange 22 in the direction of axis C. The second flange 33 comprises a second inner surface 33a, which is the lower surface on the side of the first member 20, and a second outer surface 33b, which is the upper surface on the opposite side of axis C from the first member 20 and the second inner surface 33a.

[0028] The second flange 33 is provided with circular mounting holes 34 that penetrate in the direction of axis C, opening into the second inner surface 33a and the second outer surface 33b, respectively. The mounting holes 34 are provided at positions that communicate with the two mounting holes 23 of the first flange 22. When the shaft portion 14b of the bolt 14 is inserted into the mounting holes 23 and 34 and the head 14a of the bolt 14 is placed on the first outer surface 22b, the shaft portion 14b protrudes upward from the second outer surface 33b. The first member 20 and the second member 30 are fastened to the bracket 2 by inserting this upwardly protruding shaft portion 14b into the hole 2a of the bracket 2 and fitting a nut 15 onto the tip of the shaft portion 14b with the second outer surface 33b placed on the bracket 2.

[0029] The rib 35 is a portion that protrudes from the second inner surface 33a of the second flange 33, and its cross-section perpendicular to the axis C is formed in an annular shape. The rib hole 36, which is a hole on the inner circumference side of the rib 35, opens not only at the tip of the rib 35 but also on the second outer surface 33b. Six ribs 35 are provided so that each is inserted into one of the six through holes 24. The first member 20 and the second member 30 are crimped and fixed together by these ribs 35.

[0030] Furthermore, the second outer surface 33b of the second flange 33 is formed on the same plane in the area where the mounting hole 34 is opened and in the area located on the opposite side of the rib 35 in the direction of axis C (near the rib 35). This second outer surface 33b near the rib 35 is superimposed on the bracket 2.

[0031] Referring to Figure 3, the method of crimping and fixing using the rib 35 will be explained. Figure 3 is a schematic diagram showing the crimping method as one of the manufacturing methods for the strut mount 10. Note that in Figure 3, the press molds for crimping (lower mold 41 and upper mold 42) are shown upside down in order to match the positional relationship of the first member 20 and the second member 30 with that of Figure 2. That is, during crimping and fixing, the upper side of the paper in Figure 3 becomes the lower side, and the lower side of the paper becomes the upper side. In the following explanation, the method of crimping and fixing will be explained focusing on one rib 35, but the same work and process will be performed on the other five ribs 35 simultaneously with the rib 35 of focus.

[0032] As for the crimping method, first, as shown on the left side of Figure 3, the rib 35 of the second flange 33 is formed into a cylindrical shape that extends straight in the direction of axis C (the vertical direction in the plane of the paper of Figure 3). The outer diameter of this rib 35 is approximately the same as the inner diameter of the through hole 24 of the first flange 22. Next, the cylindrical rib 35 is inserted into the through hole 24, and the overlapping first flange 22 (first member 20) and second flange 33 (second member 30) are set in a press die.

[0033] The press die comprises a lower die 41 that supports the second outer surface 33b of the second flange 33 from below, and an upper die 42 located above the first flange 22. Pressing is performed by the upper die 42 moving downward in the direction of axis C relative to the lower die 41.

[0034] On the upper surface of the lower mold 41 (the surface on the second flange 33 side), a retractable hole 43 is provided so as to be recessed in the direction of axis C, at a position that communicates with the rib hole 36 of the set second flange 33. The retractable hole 43 is a circular hole having approximately the same inner diameter as the rib hole 36.

[0035] A substantially cylindrical pin 44 protrudes in the direction of axis C from the lower surface of the upper mold 42 (the surface on the first flange 22 side) from a position opposite the retraction hole 43 in the direction of axis C. The pin 44 comprises a tip portion 44a, a tapered portion 44b provided on the base end side (the lower surface side of the upper mold 42), and an intermediate portion 44c that connects the tip portion 44a and the tapered portion 44b in the direction of axis C. The tip portion 44a is the part in which the ridge line between the tip surface and the outer peripheral surface of the pin 44 is chamfered.

[0036] The tapered portion 44b is a part that widens in a tapered shape toward the lower surface so as to form a concave corner between the lower surface of the upper mold 42 and the outer circumferential surface of the pin 44. The slope of the tapered portion 44b with respect to the axis of the pin 44 is approximately 45 degrees.

[0037] The outer diameter of the boundary between the tapered portion 44b and the intermediate portion 44c is approximately the same as the inner diameter of the cylindrical rib hole 36. The outer diameter of the intermediate portion 44c decreases slightly from this boundary towards the tip portion 44a. That is, the gradient of the intermediate portion 44c with respect to the axis of the pin 44 is extremely small (for example, about 1 to 2 degrees). Therefore, the inner diameter of the rib hole 36 and the outer diameter of the intermediate portion 44c are almost the same over almost the entire length of the rib hole 36 in the direction of the axis C.

[0038] With the overlapping first flange 22 and second flange 33 set in the lower die 41, the upper die 42 is moved toward the lower die 41, as shown in the center of Figure 3, to press-work the first flange 22 and second flange 33. At this time, the pin 44 is inserted into the rib hole 36, and the tapered portion 44b of the pin 44 is pressed against the tip of the cylindrical rib 35.

[0039] As a result, the tip of the rib 35 undergoes plastic deformation to expand in diameter along the tapered portion 44b and comes into contact with the enlarged hole portion 25 of the through hole 24. Finally, as shown on the right side of Figure 3, the first member 20 and the second member 30 are removed from between the lower mold 41 and the upper mold 42, thereby obtaining the first member 20 and the second member 30 that have been crimped and fixed by the expansion of the rib 35.

[0040] Furthermore, since the rib hole 36 opens into the second outer surface 33b of the second flange 33, the pin 44 can be made to protrude from the second outer surface 33b during press working. Also, since the pin 44 protruding from the second outer surface 33b is inserted into the retraction hole 43, interference between the pin 44 and the lower die 41 can be suppressed. In this way, freedom of the height of the pin 44 can be ensured, and freedom of the method of expanding the diameter of the rib 35 and crimping it in place can be ensured.

[0041] Furthermore, if the rib hole 36 does not open to the second outer surface 33b, the height of the pin 44 must be set so that it does not hit the bottom of the rib hole 36. In this case, during press working, the material around the rib hole 36 is more likely to plastically deform inward toward the relatively large gap between the bottom of the rib hole 36 and the tip surface of the pin 44. Similarly, during press working, the material around the rib hole 36 is more likely to plastically deform inward toward the relatively large gap between the inner circumferential surface of the rib hole 36 and the chamfered portion of the tip 44a. As a result, the force received by the rib 35 from the tapered portion 44b decreases, resulting in insufficient diameter expansion of the rib 35, and potentially insufficient joint strength due to crimping by the rib 35.

[0042] In contrast, in this embodiment, during press working, the tip portion 44a of the pin 44 is located within the retraction hole 43, and within the rib hole 36, there is an intermediate portion 44c where the inner and outer diameters of the rib hole 36 are almost the same, extending over approximately the entire length in the direction of axis C. As a result, the inside of the rib hole 36 is almost completely filled with the intermediate portion 44c, making it difficult for the material surrounding the rib hole 36 to undergo plastic deformation inward. Therefore, the tapered portion 44b can sufficiently expand the diameter of the rib 35, and the joint strength of the riveting fixation by the rib 35 can be ensured.

[0043] According to the strut mount 10 described above, the cross-section of the rib 35 perpendicular to the axis C direction is formed in an annular shape, and the tip of the rib 35 is expanded in diameter, thereby crimping and fixing the first member 20 and the second member 30. If the tip of this rib 35 is reduced in diameter, the crimping is released. However, compared to the case where a plate-shaped claw for crimping is bent in the thickness direction of the plate, as in the prior art (for example, Japanese Patent Publication No. 2010-14133), a large force is required to reduce the diameter of the rib 35. Therefore, with crimping and fixing by the rib 35, it is easier to ensure the joint strength between the first member 20 and the second member 30.

[0044] Furthermore, if the first member 20 and the second member 30 are joined by welding instead of riveting, the penetration during welding may be insufficient depending on the plate thickness of the first flange 22 and the second flange 33 and the performance of the welding machine. In other words, welding may not be able to ensure the joint strength between the first member 20 and the second member 30.

[0045] In contrast, with riveting fixation using ribs 35, joint strength can be ensured almost independently of the plate thickness of the first flange 22 and the second flange 33. In other words, with riveting fixation using ribs 35, a degree of freedom in the plate thickness of the first flange 22 and the second flange 33 can be ensured.

[0046] Furthermore, once the first member 20 and the second member 30 have been coated with a rust-preventive cationic coating, they cannot be welded together. Due to film formation during welding, there is a risk of defects occurring if cationic coating is applied after welding. Therefore, when welding the first member 20 and the second member 30, it is necessary to apply a rust-preventive black coating after welding. Since the black coating is applied individually to each welded first member 20 and second member 30, it is time-consuming during mass production.

[0047] In this embodiment, the first member 20 and the second member 30 are joined by crimping, which does not require current to be supplied to them, so cationic coating can be performed before joining. Since cationic coating can be applied to a large number of first members 20 and second members 30 at once, it is easier to reduce the number of man-hours during mass production.

[0048] When the first member 20 and the second member 30 are crimped and fixed together, the tip of the enlarged rib 35 contacts the enlarged hole portion 25 of the through hole 24, and the rib 35 is positioned on the second flange 33 side of the first outer surface 22b. In this way, since the rib 35 for crimping does not protrude from the first outer surface 22b, it is possible to make the first outer surface 22b around the through hole 24 adhere closely to other members.

[0049] In this embodiment, there is no member that is in close contact with the periphery of the through-hole 24. However, if the joint portion formed by the rib 35 and the through-hole 24 is inverted, for example, the bracket 2 will overlap the first outer surface 22b surrounding the through-hole 24. Furthermore, by making the head 14a of the bolt 14 larger or by bringing the mounting holes 23, 34 closer to the through-hole 24, the head 14a of the bolt 14 will overlap the first outer surface 22b surrounding the through-hole 24. If the tip of the rib 35 protrudes from the first outer surface 22b, these brackets 2 and bolts 14 will not be in close contact with the first outer surface 22b and will float above it. This may cause problems in fastening the first member 20 and the second member 30 to the bracket 2 with the bolts 14 and nuts 15. However, by preventing such protrusion and making it easier to bring the brackets 2 and bolts 14 into close contact with the first outer surface 22b surrounding the through-hole 24, problems in fastening can be suppressed.

[0050] However, even if the rib 35 is designed not to protrude from the first outer surface 22b, such protrusion may occur due to manufacturing tolerances or other factors. If this occurs, as described above, problems may arise in fastening the first member 20 and the second member 30 to the bracket 2.

[0051] In contrast, in this embodiment, the second outer surface 33b, which is opposite to the tip of the rib 35, is configured to overlap the bracket 2, rather than the first outer surface 22b, which may have the tip of the rib 35 protruding. Therefore, it is possible to prevent the second outer surface 33b from lifting away from the bracket 2 due to the tip of the rib 35, which would cause fastening problems.

[0052] In this embodiment, mounting holes 23 and 34 for fastening bolts 14 to the first member 20 and the second member 30 are provided in the bracket 2 separately from the rib holes 36. This allows the first outer surface 22b at the position where the head 14a of the bolt 14 overlaps to be separated from the area around the through hole 24 into which the rib 35 is inserted. As a result, even if the tip of the rib 35 protrudes from the first outer surface 22b, it is less likely for the tip of the rib 35 to come into contact with the head 14a, making it easier to bring the bolt 14 into close contact with the first outer surface 22b. Consequently, problems with fastening by the bolt 14 can be suppressed.

[0053] Next, a second embodiment will be described with reference to Figures 4 and 5. In the second embodiment, a case will be described in which a rib hole 56 is used as a mounting hole into which a bolt 14 for fastening the first member 20 and the second member 30 to the bracket 2 is inserted. Note that parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions will be omitted below.

[0054] Figure 4 is a top view of the strut mount 50 in the second embodiment. Figure 5 is a cross-sectional view of the strut mount 50 along the VV line in Figure 4. Figure 5 shows the strut mount 50 mounted on a vehicle, similar to Figure 2.

[0055] The strut mount 50 omits two of the six joints formed by through holes 24 and ribs 35 in the strut mount 10 of the first embodiment, specifically the two joints between the mounting holes 23 and 34 and the axis C. Furthermore, the strut mount 50 has joints (rib holes 56) formed by through holes 51 and ribs 55 at the positions of the two mounting holes 23 and 34 in the first embodiment. The other parts of the strut mount 50 are configured identically to the parts of the strut mount 10 in the first embodiment.

[0056] The through-hole 51 is a circular hole that penetrates the first flange 22 in the direction of axis C, opening into the first inner surface 22a and the first outer surface 22b, respectively. The through-hole 51 is provided at two locations in the circumferential direction of the first flange 22. The inner circumferential surface of the through-hole 51 has an enlarged diameter hole portion 52 at the connection point with the first outer surface 22b, which tapers in diameter towards the first outer surface 22b. The inner circumferential surface of the through-hole 51, excluding the enlarged diameter hole portion 52, has a uniform inner diameter along the direction of axis C. Thus, the through-hole 51 has substantially the same shape as the through-hole 24 described in the first embodiment, but has a larger inner diameter than the through-hole 24.

[0057] The rib 55 is a portion that protrudes from the second inner surface 33a of the second flange 33, and its cross-section perpendicular to the axis C is formed in an annular shape. The rib hole 56, which is a hole on the inner circumference side of the rib 55, opens not only at the tip of the rib 55 but also on the second outer surface 33b. Two ribs 55 are provided so that they are inserted into two through holes 51, respectively.

[0058] With the rib 55 inserted into the through hole 51, the tip of the rib 55 is expanded in the same manner as the expansion of the rib 35 in the first embodiment. The expanded rib 55 rivets and fixes the first member 20 and the second member 30 together. Thus, the rib 55 and the rib hole 56 are substantially the same shape as the rib 35 and rib hole 36 described in the first embodiment, with the outer diameter of the rib 55 being larger than that of the rib 35 and the inner diameter of the rib hole 56 being larger than that of the rib hole 36.

[0059] When the shaft portion 14b of the bolt 14 is inserted into the rib hole 56 and the head portion 14a of the bolt 14 is placed on the first outer surface 22b, the shaft portion 14b protrudes upward from the second outer surface 33b. The press-fit portion 14c provided on the head portion 14a side of the shaft portion 14b is press-fitted into the rib hole 56, thereby fixing the bolt 14 to the first member 20 and the second member 30.

[0060] The shaft portion 14b protruding upward from the second outer surface 33b is inserted into the hole 2a of the bracket 2, and with the second outer surface 33b superimposed on the bracket 2, the nut 15 is fitted onto the tip of the shaft portion 14b, thereby fastening the first member 20 and the second member 30 to the bracket 2. In this embodiment, the rib holes 56 formed by the rib 55 for crimping are used as mounting holes into which bolts 14 for fastening to the bracket 2 of the vehicle body are inserted. Therefore, compared to the first embodiment in which these holes are provided separately, the number of holes to be drilled in the first flange 22 and the second flange 33 can be reduced. As a result, the cost of drilling holes in the first flange 22 and the second flange 33 can be reduced. Specifically, when holes are drilled by press working, the cost of the mold for press working can be reduced.

[0061] In this embodiment, the inner diameter of the rib hole 56 used as a mounting hole for the bolt 14 is different from the inner diameter of the rib hole 36 that is not used as a mounting hole. This makes it easier for workers inserting the bolt 14 into the mounting hole to find the mounting hole among the multiple rib holes 36 and 56. Furthermore, the inner diameter of the rib hole 56 is larger than the inner diameter of the rib hole 36, and the outer diameter of the rib 55 is larger than the outer diameter of the rib 35. This larger rib 55 improves the joint strength of the crimped fixing. On the other hand, because the rib 35 is small, it is easier to provide a joint portion by the rib 35 even in the narrow space between the first flange 22 and the second flange 33. In addition, because the rib 35 is small, the load required to expand the diameter of the rib 35 can be reduced, making the crimping fixing work easier.

[0062] The tip of the enlarged rib 55 contacts the enlarged hole portion 52 of the through hole 51, and the rib 55 is positioned on the second flange 33 side of the first outer surface 22b. Therefore, the head 14a of the bolt 14 can be easily brought into close contact with the first outer surface 22b surrounding the rib hole 56 and the through hole 51. Thus, it is possible to suppress the lifting of the head 14a from the first outer surface 22b due to the tip of the rib 55 contacting the head 14a, and thus suppress problems with fastening the bolt 14 that may occur as a result of this lifting.

[0063] Furthermore, since the bolt 14 is inserted into the rib hole 56, the reduction in diameter of the tip of the enlarged rib 55 can be suppressed. In particular, since the press-fit portion 14c of the bolt 14 is press-fitted into the rib hole 56, the reduction in diameter of the tip of the rib 55 can be further suppressed. As a result, it is possible to suppress the release of the crimped fixation between the first member 20 and the second member 30 due to the reduction in diameter of the tip of the rib 55. In other words, the joint strength of the crimped fixation by the rib 55 can be improved.

[0064] Although the present invention has been described above based on embodiments, it can be easily inferred that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention. For example, the first member 20 may be provided with a cylindrical portion 32 such as the second member 30, or the cylindrical portion 32 may be omitted from the second member 30. The bolt 14 and nut 15 may be inverted, and the nut 15 may be superimposed on the first outer surface 22b.

[0065] The number of parts listed in the above embodiment is merely an example, and it is certainly possible to use other numbers. For example, the number of joints formed by the ribs 35, 55 and through holes 24, 51 is not limited to a total of 6; there may be 5 or fewer, or 7 or more such joints. Also, the number of mounting holes 23, 34, rib holes 56, and bolts 14 may be 3 or more.

[0066] The positions of the joints formed by the ribs 35, 55 and the through holes 24, 51 may be changed as appropriate. The joints may not be in a position that overlaps with the bracket 2, nor may they be in a position that overlaps with the bracket 2. Also, the joints may not be in a position that overlaps with the bolts 14 and nuts 15, nor may they be in a position that overlaps with the bolts 14 and nuts 15. Furthermore, the inner diameters of the rib holes 56 and the mounting holes 23, 34 may be changed as appropriate according to the size of the bolts 14 inserted into them. The inner diameter of the rib hole 36 may be the same as the inner diameters of the rib holes 56 and the mounting holes 23, 34, or it may be larger than them.

[0067] In the above embodiment, the case in which the tips of the ribs 35 and 55 are located on the second flange 33 side of the first outer surface 22b has been described, but this is not necessarily the only case. For example, the tips of the ribs 35 and 55 may protrude from the first outer surface 22b. Also, the enlarged diameter portions 25 and 52 of the through holes 24 and 51 may be omitted, and the tips of the ribs 35 and 55 may be enlarged in a flange shape so as to follow the first outer surface 22b.

[0068] In the above embodiment, a case was described in which the first member 20 having through holes 24, 51 supports the vibration-damping base 13 from below, and the second member 30 having ribs 35, 55 is placed over the vibration-damping base 13. However, the embodiment is not necessarily limited to this. The first member 20 and the second member 30 may be inverted vertically so that the second member 30 having ribs 35, 55 supports the vibration-damping base 13 from below, and the first member 20 having through holes 24, 51 is placed over the vibration-damping base 13. [Explanation of Symbols]

[0069] 2. Bracket (part of the vehicle body) 4. Piston rod (part of the shock absorber) 10.50 Strut Mount 11 Inner member 13 Vibration Isolation Base 14 volts 14a head 14b Shaft 20 First Member 22 First flange 22b 1st outer surface 23,34 mounting holes 24,51 Through hole 25,52 Enlarged diameter hole section 30 Second Member 33. Second flange 33b 2nd outer surface 35.55 Rib 36,56 rib holes C axis

Claims

1. In a strut mount interposed between the vehicle body and the piston rod of the shock absorber, An inner member attached to the tip of the piston rod, An annular vibration-damping base made of an elastic material is attached to the inner member so as to surround the axis of the piston rod, It comprises a first member and a second member that are attached to the vehicle body and sandwich the vibration-damping base in the axial direction, The first member includes a first flange formed in an annular shape that protrudes radially outward from the vibration-damping base, Multiple circular through holes extending axially are provided at several locations in the circumferential direction of the first flange. The second member comprises an annular second flange superimposed axially on the first flange, It comprises a plurality of ribs, each protruding from the second flange and inserted into each of the plurality of through holes, with a cross-section perpendicular to the axial direction formed in an annular shape, A strut mount characterized in that the first member and the second member are crimped and fixed together by expanding the diameter of the tip of the rib inserted into the through hole.

2. The first flange has a first outer surface opposite to the second flange in the axial direction, The inner circumferential surface of the through hole is provided with an enlarged diameter hole portion at the connection point with the first outer surface, which widens in diameter toward the first outer surface. The strut mount according to claim 1, characterized in that the tip of the enlarged rib contacts the enlarged hole, thereby crimping and fixing the first member and the second member, and the rib is positioned on the second flange side of the first outer surface.

3. The first flange has a first outer surface opposite to the second flange in the axial direction, The second flange has a second outer surface opposite to the first flange in the axial direction, The strut mount comprises a plurality of bolts for fastening the first member and the second member to the vehicle body. Multiple bolts are inserted into multiple mounting holes that penetrate the first flange and the second flange in the thickness direction, such that the heads of the bolts overlap the first outer surface and the shafts of the bolts protrude from the second outer surface. The strut mount according to claim 1 or 2, characterized in that the second outer surface is formed such that the portion where the mounting hole is opened and the portion located on the opposite side in the axial direction from the rib are on the same plane.

4. The second flange has a second outer surface opposite to the first flange in the axial direction, The strut mount according to claim 1 or 2, characterized in that a rib hole, which is a hole on the inner circumference side of the rib, is opened on the second outer surface.

5. The strut mount comprises a plurality of bolts for fastening the first member and the second member to the vehicle body. The strut mount according to claim 4, characterized in that the multiple bolts are each inserted into two or more of the multiple rib holes.

Images