Strut mount

Abstract

To provide a strut mount capable of reducing a thickness dimension of a vehicle body-side member.SOLUTION: A strut mount includes: a vehicle body-side member 10 connected to a vehicle body D; a rod-side member 20 to which a tip of a piston rod PR is connected; and an elastic member 30 disposed between the vehicle body-side member 10 and the rod-side member 20. As an inner diameter d1 of a through hole OP on the vehicle body BD is larger than an inner diameter D1 of a lower cylindrical portion 14, a region S1 where an input from a bound damper BB1 and reaction force from the vehicle body BD are overlapped, is formed in a case when the input from the bound damper BB1 is acted on the vehicle body-side member 10, and the input and the reaction force can be canceled for the region S1. As a result, generation of shearing stress on the vehicle body-side member 10 can be suppressed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a strut mount, and more particularly to a strut mount that can suppress the occurrence of shear stress in a vehicle body member. [Background technology]

[0002] BACKGROUND ART A strut mount that is interposed between a vehicle body and a piston rod of a shock absorber is known (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-102506 A (e.g., Figure 3) Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional strut mount described above has a problem in that shear stress is easily generated in the vehicle body member due to the load received during driving.

[0005] This problem will be explained with reference to Figure 3, which is a longitudinal cross-sectional view of a conventional strut mount 1000. As shown in Figure 3, the strut mount 1000 includes a vehicle body side member 1010 that is connected to the vehicle body BD, a rod side member 1020 to which the tip of the piston rod PR is connected, and an elastic member 1030 that is interposed between the vehicle body side member 1010 and the rod side member 1020.

[0006] While the vehicle is moving, an input (arrow B) from the shock absorber's bound bumper (not shown) acts on the underside of the vehicle body side member 1010 of the strut mount 1000, and a reaction force (arrow A) from the vehicle body BD in response to that input acts on the upper surface of the vehicle body side member 1010.

[0007] In this case, the input force from the bound bumper (arrow B) acts on the central part of the body side member 1010 centered on the piston rod PR, while the reaction force from the body BD (arrow A) acts on the outer edge part of the body side member 1010.

[0008] Therefore, there was a problem in that shear stress occurred in the area between the area where the input from the bound bumper (arrow B) acts and the area where the reaction force from the vehicle body BD (arrow A) acts (the area hatched with cross-hatching in Figure 3, hereinafter referred to as the "intermediate area 1010a").

[0009] The present invention has been made to solve the above-mentioned problems, and has an object to provide a strut mount that can suppress the occurrence of shear stress in a vehicle body member. [Means for solving the problem]

[0010] To achieve this object, the strut mount of the present invention is interposed between a vehicle body and a piston rod of a shock absorber, and comprises a vehicle body side member connected to the vehicle body, a rod side member to which the tip of the piston rod is connected, and an elastic member interposed between the vehicle body side member and the rod side member, The vehicle body side member includes an upper cylindrical portion formed in a cylindrical shape surrounding the rod side member, a bottom portion formed by protruding radially inward from a lower end side of the upper cylindrical portion, an arm portion formed by protruding radially outward from the lower end side of the upper cylindrical portion and having an upper surface to which the vehicle body is connected, and a lower cylindrical portion protruding from a lower surface of the arm portion and formed in a cylindrical shape approximately concentric with the upper cylindrical portion, The outer diameter of a region on the lower surface of the vehicle body side member where the bound bumper of the shock absorber can abut is larger than the inner diameter of a region on the upper surface of the vehicle body side member where the vehicle body is connected. The inner diameter of the lower cylindrical portion is larger than the outer diameter of the upper cylindrical portion. do. [Effects of the Invention]

[0011] The strut mount of claim 1 includes a vehicle-body member connected to the vehicle body, a rod-side member connected to the tip of the piston rod, and an elastic member interposed between the vehicle-body member and the rod-side member, and the outer diameter of the area on the underside of the vehicle-body member where the shock absorber's bound bumper can contact is larger than the inner diameter of the area on the upper surface of the vehicle-body member where the vehicle body is connected. Therefore, when an input from the bound bumper acts on the vehicle-body member, an area is formed where the input from the bound bumper and the reaction force from the vehicle body overlap, and the input and reaction force can be offset by this overlapping area, thereby suppressing the generation of shear stress in the vehicle-body member.

[0012] car The body-side member includes an upper cylindrical portion formed in a cylindrical shape surrounding the rod-side member, a bottom portion formed by extending radially inward from the lower end of the upper cylindrical portion, an arm portion formed by extending radially outward from the lower end of the upper cylindrical portion and having an upper surface for connecting to the vehicle body, and a lower cylindrical portion protruding from the lower surface of the arm portion and formed in a cylindrical shape approximately concentric with the upper cylindrical portion, and because the inner diameter of the lower cylindrical portion is larger than the outer diameter of the upper cylindrical portion, an area where the input force from the bound bumper and the reaction force from the vehicle body overlap can be formed in the arm portion of the vehicle-side member. Therefore, the input force and the reaction force are offset by the amount of the overlap, and shear stress can be suppressed in the vehicle-side member.

[0013] Claim 2 According to the strut mount described, claims 1 In addition to the effects of the strut mount described above, the vehicle body component has a flat, flush underside of the base and the underside of the arm at least radially inward of the lower tube portion, which distributes the force from the bound bumper to both the base and the arm. This reduces shear stress in the vehicle body component compared to a configuration in which the force from the bound bumper acts primarily on the underside of the arm.

[0014] Furthermore, by forming the underside of the arm portion at least radially inward of the lower tube portion as a flat surface, it is easier to secure an area where the input from the bound bumper and the reaction force from the vehicle body overlap, compared to a configuration in which the underside of the arm portion at least radially inward of the lower tube portion has a step.

[0015] Claim 3 According to the strut mount described, claims 2 In addition to the effects of the strut mount described above, the arm portion of the vehicle body side member is formed as a plate with approximately parallel upper and lower surfaces, which allows the input force from the bound bumper and the reaction force from the vehicle body to be more efficiently offset than, for example, a configuration in which the upper and lower surfaces are not parallel.

[0016] Claim 4 The strut mount described has a through hole through which the piston rod of the shock absorber is inserted, and is provided with a ring member connected to the underside of the vehicle body member, so that input from the bound bumper can be applied to the vehicle body member via the ring member.

[0017] In this case, the outer diameter of the upper surface of the ring member is made larger than the inner diameter of the area on the upper surface of the vehicle body side member to which the vehicle body is connected. 3 In addition to the effects of the strut mount described in any one of the above, even if the outer diameter of the upper surface of the bound bumper is smaller than the inner diameter of the area on the upper surface of the vehicle body member to which the vehicle body is connected, an area can be formed where the input force from the bound bumper and the reaction force from the vehicle body overlap, thereby canceling out the input force and reaction force by the amount of the overlap, and suppressing the generation of shear stress in the vehicle body member.

[0018] Claim 5 According to the strut mount described, claims 4 In addition to the effects of the strut mount described above, the ring member has a larger outer diameter on the top surface than on the bottom surface, which effectively expands the input force from the bound bumper to a region where it overlaps with the reaction force from the vehicle body. The ring member can also be made lighter. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1(a) is a top view of a strut mount according to a first embodiment of the present invention, and FIG. 1(b) is a vertical cross-sectional view of the strut mount taken along line Ib-Ib in FIG. 1(a). [Figure 2] 10(a) is a vertical cross-sectional view of a strut mount according to a second embodiment, and FIG. 10(b) is a vertical cross-sectional view of a strut mount according to a third embodiment. [Figure 3] FIG. 1 is a vertical cross-sectional view of a conventional strut mount. DETAILED DESCRIPTION OF THE INVENTION

[0020] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Figure 1(a) is a top view of a strut mount 1 according to a first embodiment of the present invention, and Figure 1(b) is a longitudinal cross-sectional view of the strut mount 1 taken along line Ib-Ib in Figure 1(a). Figure 1(b) shows the strut mount 1 mounted on a vehicle body BD.

[0021] 1, strut mount 1 is interposed between a vehicle body BD and a piston rod PR of a shock absorber. In detail, strut mount 1 includes a vehicle body member 10 connected to the vehicle body BD, a rod side member 20 to which the tip of the piston rod PR is connected, and an elastic member 30 interposed between the vehicle body member 10 and the rod side member 20.

[0022] The vehicle body side member 10 and the rod side member 20 are made of a metal material, and the elastic member 30 is made of a rubber-like elastic body. In this embodiment, the vehicle body side member 10 is made of an aluminum alloy casting, and the rod side member 20 is made of a steel material.

[0023] The vehicle body side member 10 comprises an upper tube portion 11 formed in a tubular shape (approximately cylindrical with the axis O as its center) that surrounds the rod side member 20, a bottom portion 12 formed by extending radially inward from the lower end side of the upper tube portion 11, an arm portion 13 formed by extending radially outward from the lower end side of the upper tube portion 11 and having an upper surface to which the vehicle body BD is connected, and a lower tube portion 14 protruding from the lower surface of the arm portion 13 and formed in a tubular shape (approximately cylindrical with the axis O as its center) that is approximately concentric with the upper tube portion 11.

[0024] A disk-shaped upper cover member 40 is disposed at the upper end of the upper cylindrical portion 11, and an elastic member 30 is disposed between this upper cover member 40 and the bottom portion 12 in a state where it is compressed in the direction of the axis O. A circular through-hole is formed in the center of the upper cover member 40, and a nut N1 that is fastened to the tip of the piston rod PR is inserted into this through-hole.

[0025] Before the upper cover member 40 is installed, a bent piece protrudes from the upper end of the upper tube portion 11 around the entire circumference, and by bending the bent piece radially inward, the upper cover member 40 is crimped and fixed to the upper end of the upper tube portion 11.

[0026] A circular through-hole is formed in the center of the bottom portion 12, and a piston rod PR is inserted through this through-hole. In this embodiment, the thickness dimension (dimension in the direction of the axis O) of the bottom portion 12 is larger than the thickness dimension of the arm portion 13.

[0027] The arm portion 13 is formed in a generally triangular shape when viewed from above, and is formed in a flat plate shape with a generally constant thickness dimension (dimension in the direction of the axis O). Fastening holes 13a are formed through the arm portion 13 at a plurality of locations (three locations in this embodiment) that are equally spaced in the circumferential direction, and nuts N2 are fastened to the tips of bolts B2 inserted into each of the fastening holes 13a, thereby connecting (fastening and fixing) the vehicle body BD to the upper surface of the arm portion 13.

[0028] In this embodiment, the upper surface of the arm portion 13 is a flat surface perpendicular to the axis O. A circular through-hole OP is formed through the vehicle body BD, and the inner diameter of the through-hole OP is d1 (hereinafter referred to as "inner diameter d1"). Note that, taking into account the dimensional tolerance of the through-hole OP, a flat surface that can abut against the lower surface of the vehicle body BD is secured on the upper surface of the arm portion 13 over an area wider than the inner diameter d1 (toward the axis O). Furthermore, the upper surface of the arm portion 13 and the outer peripheral surface of the upper tube portion 11 are smoothly connected by a cross-sectional arc shape.

[0029] The lower surface of the arm portion 13, at least the lower surface radially inward (toward the axis O) of the lower cylinder portion 14, is flush with the lower surface of the bottom portion 12, and a flat surface approximately parallel to the upper surface of the arm portion 13 is formed radially inward of the lower cylinder portion 14.

[0030] A recess is formed on the inner peripheral surface of the lower cylinder portion 14, and a protrusion of the bound bumper BB1 of the shock absorber is fitted into this recess, thereby holding the bound bumper BB1 on the lower cylinder portion 14. In other words, the upper surface of the bound bumper BB1 can abut against the lower surface of the bottom portion 12 and the lower surface of the arm portion 13.

[0031] The minimum value of the inner diameter of the lower cylindrical portion 14 is D1 (hereinafter referred to as "inner diameter D1"). This inner diameter D1 is larger than the outer diameter of the upper cylindrical portion 11 and also larger than the inner diameter d1 of the through hole OP of the vehicle body BD (d1 <D1)。

[0032] The rod-side member 20 has a cylindrical tube portion with a circular through-hole formed therethrough and a protruding portion formed to protrude radially outward from the tube portion, and is connected (fastened and fixed) to the tip of the piston rod PR by fastening a nut N1 to the tip of the piston rod PR inserted into the through-hole of the tube portion. An elastic member 30 is vulcanization-bonded to the rod-side member 20 around the entire periphery of the protruding portion.

[0033] According to the strut mount 1, the outer diameter of the area on the underside of the vehicle body member 10 where the bound bumper BB1 of the shock absorber can abut is larger than the inner diameter of the area on the upper surface of the vehicle body member 10 where the vehicle body BD is connected. In detail, the minimum inner diameter D1 of the lower cylindrical portion 14 is larger than the inner diameter d1 of the through hole OP of the vehicle body BD (d1 <D1)。

[0034] As a result, when an input from the bound bumper BB1 acts on the vehicle body member 10 as the vehicle travels, an area (indicated by the symbol "S1" in FIG. 1, hereinafter referred to as "area S1") where the input from the bound bumper BB1 and the reaction force from the vehicle body BD overlap is formed, and the input and reaction force can be offset by the amount of area S1. As a result, it is possible to suppress the generation of shear stress in the vehicle body member 10 (arm portion 13).

[0035] In the vehicle body side member 10, the lower surface of the bottom portion 12 and the lower surface of the arm portion 13 at least radially inward of the lower cylinder portion 14 are formed as a flush flat surface, so that the force from the bound bumper BB1 can be distributed to both the bottom portion 12 and the arm portion 13. Therefore, for example, by positioning the lower surface of the bottom portion 12 higher than the lower surface of the arm portion 13 and forming a step between them, the strength required for the arm portion 13 can be reduced compared to a configuration in which the force from the bound bumper BB1 acts mainly on the lower surface of the arm portion 13. As a result, the thickness dimension of the vehicle body side member 10 (arm portion 13) can be reduced.

[0036] Furthermore, by forming the entire lower surface of at least the arm portion 13 radially inward from the lower cylinder portion 14 as a flat surface, an area with which the upper surface of the bound bumper BB1 can come into contact can be secured. Therefore, compared to a configuration in which, for example, the lower surface of at least the arm portion 13 radially inward from the lower cylinder portion 14 has a step (a configuration in which a portion of the lower surface is positioned higher than the rest, and the upper surface of the bound bumper BB1 mainly comes into contact with that rest), it is easier to secure an area S1 where the input from the bound bumper BB1 and the reaction force from the vehicle body BD overlap.

[0037] The arm portion 13 is formed in the shape of a plate with its upper and lower surfaces being approximately parallel, and therefore, compared to a configuration in which, for example, the upper and lower surfaces are non-parallel, the input force from the bound bumper BB1 and the reaction force from the vehicle body BD can be more efficiently offset.

[0038] In this embodiment, as described above, the thickness dimension (dimension in the direction of axis O) of bottom portion 12 is larger than the thickness dimension (dimension in the direction of axis O) of arm portion 13, and the upper surface of arm portion 13 and the outer peripheral surface of upper tubular portion 11 are smoothly connected by a cross-sectional arc shape. Therefore, the strength of bottom portion 12 can be utilized to ensure the strength of the base portion of arm portion 13 (portion on the upper tubular portion 11 side).

[0039] Next, a second embodiment will be described. In the first embodiment, the bound bumper BB1 is held by the lower cylindrical portion 14 of the vehicle body member 10, but in the second embodiment, the bound bumper BB2 is fitted and fixed to the outside of the piston rod PR of the shock absorber. That is, the outer diameter of the upper surface of the bound bumper BB2 in the second embodiment is made smaller than the outer diameter of the upper surface of the bound bumper BB1 in the first embodiment. In this embodiment, the outer diameter of the upper surface of the bound bumper BB2 is made smaller than the inner diameter d1 of the through hole OP in the vehicle body BD.

[0040] Figure 2(a) is a vertical cross-sectional view of a strut mount 201 in the second embodiment, and corresponds to Figure 1(b). Note that the same parts as those in the first embodiment described above are given the same reference numerals, and their description will be omitted.

[0041] 2(a), the strut mount 201 includes a ring member 250 made of a metal material, and the upper surface of the ring member 250 is connected by adhesive to the bottom portion 12 and the lower surface of the arm portion 13 of the vehicle body side member 10. In this embodiment, the ring member 250 is made of an aluminum alloy casting.

[0042] The ring member 250 is a disc-shaped member with a circular through-hole formed through the center, and a piston rod PR is inserted through the through-hole. The upper and lower surfaces of the ring member 250 are flat surfaces parallel to each other.

[0043] The dimension of the outer diameter of the upper surface of the ring member 250 is D2 (hereinafter referred to as "outer diameter D2"), and this outer diameter D2 is made larger than the outer diameter of the upper cylinder portion 11 and also larger than the inner diameter d1 of the through-hole OP of the vehicle body BD (d1 < D2). Therefore, the input from the bumper BB2 can be applied to the vehicle body side member 10 (bottom portion 12 and arm portion 13) via the ring member 250.

[0044] Thereby, even when the outer diameter of the upper surface of the bumper BB2 is smaller than the inner diameter d1 of the through-hole OP of the vehicle body BD (the inner diameter of the region where the vehicle body BD is connected to the upper surface of the vehicle body side member 10), a region S2 where the input from the bumper BB2 and the reaction force from the vehicle body BD overlap can be formed. Therefore, due to that region S2, the input and the reaction force can be offset, and the generation of shear stress in the vehicle body side member 10 (arm portion 13) can be suppressed.

[0045] Since the strut mount 201 in the second embodiment has a configuration in which the ring member 250 is disposed (connected) to the strut mount 1 in the first embodiment, the strut mount 1 in the first embodiment can be diverted. Therefore, for example, when the specifications of the shock absorber are changed (the bumper BB1 is changed to the bumper BB2), it is not necessary to design a new strut mount different from the strut mount 1 in accordance with the change.

[0046] The outer diameter D2 of the upper surface of the ring member 250 is made larger than the outer diameter of the lower surface. Therefore, the input from the bumper BB2 can be efficiently expanded by the ring member 250 to the region where it overlaps with the reaction force from the vehicle body BD. Also, the ring member 250 can be lightened due to the chamfered side surface.

[0047] Next, a third embodiment will be described. Figure 2(b) is a vertical cross-sectional view of a strut mount 301 in the third embodiment, and corresponds to Figure 1(b). Note that the same parts as those in the above-mentioned embodiments are given the same reference numerals, and their description will be omitted.

[0048] As shown in Figure 2(b), strut mount 301 has the same configuration as strut mount 1 in the first embodiment, except that it does not include lower cylinder portion 14. Ring member 350 has the same configuration as ring member 250 in the second embodiment, except that it additionally includes protrusion 351.

[0049] The ring member 350 has a protrusion 351 protruding from its upper surface around the entire circumference, and the protrusion 351 is press-fitted into a through-hole in the center of the bottom portion 12, thereby press-fitting and fixing the ring member 350 to the underside of the vehicle body side member 10 (bottom portion 12). This makes it possible to prevent the ring member 350 from falling off, compared to when it is bonded. Note that the protrusion 351 may be formed discontinuously in the circumferential direction.

[0050] The present invention has been described above based on an embodiment, but the present invention is not limited to the above embodiment, and it can be easily inferred that various improvements and modifications are possible within the scope of the present invention.

[0051] The numerical values ​​given in the above embodiment are merely examples, and other numerical values ​​can of course be adopted. Similarly, the number of each component to be provided is arbitrary.

[0052] In the above embodiments, the vehicle body member 10 and the ring members 250, 350 are formed by casting, but they may also be formed by cutting. Also, the ring members 250, 350 may be formed from a resin material such as PPA or PPS.

[0053] In the second or third embodiment, the structure has been described in which the ring members 250, 350 are connected (disposed) to the vehicle body side member 10 by adhesive or press fitting, but other structures may also be employed.

[0054] For example, a structure may be used in which an internal thread is threaded on the inner peripheral surface of the through-hole of the bottom portion 12 and an external thread is threaded on the outer peripheral surface of the protruding portion 351 of the ring member 350, and these are screwed together. Alternatively, for example, a structure may be used in which a bent piece is protruded from the lower surface of the arm portion 13 along the entire circumference (or intermittently in the circumferential direction), and the bent piece is bent radially inward and abuts against the inclined surfaces of the ring members 250, 350 (i.e., a structure substantially the same as the structure in which the upper cover member 40 is crimped and fixed by a bent piece protruding from the upper end of the upper cylindrical portion 11). [Explanation of symbols]

[0055] 1,201,301 Strut mount 10 Body side components 11 Upper cylinder part 12 Bottom 13 Arm 14 Lower cylinder part D1 Inner diameter of lower cylinder 20 Rod side member 30 Elastic member 250,350 Ring member D2 Outer diameter of the top surface of the ring member BD body d1 Inner diameter of through hole in the body PR piston rod BB1, BB2 Bound Bumper

Claims

1. In a strut mount interposed between a vehicle body and a piston rod of a shock absorber, a vehicle body side member connected to the vehicle body; a rod side member to which the tip of the piston rod is connected; an elastic member interposed between the vehicle body side member and the rod side member, The vehicle body side member is an upper cylindrical portion formed in a cylindrical shape surrounding the rod side member; a bottom portion formed by extending radially inward from a lower end side of the upper cylindrical portion; an arm portion formed to extend radially outward from a lower end side of the upper cylindrical portion and having an upper surface to which the vehicle body is connected; a lower cylinder portion protruding from the underside of the arm portion and formed in a cylindrical shape substantially concentric with the upper cylinder portion; an outer diameter of a region on the lower surface of the vehicle body side member where a bound bumper of the shock absorber can abut is larger than an inner diameter of a region on the upper surface of the vehicle body side member where the vehicle body is connected; A strut mount characterized in that the inner diameter of the lower cylindrical portion is larger than the outer diameter of the upper cylindrical portion.

2. 2. The strut mount according to claim 1, wherein the vehicle body member has a lower surface of the bottom portion and a lower surface of the arm portion radially inward of the lower cylindrical portion formed as a flat surface.

3. 3. The strut mount according to claim 2, wherein the arm portion of the vehicle body member is formed in a plate shape with an upper surface and a lower surface that are substantially parallel to each other.

4. a ring member having a through hole formed therethrough through which the piston rod of the shock absorber is inserted and connected to a lower surface of the vehicle body member; 4. The strut mount according to claim 1, wherein the outer diameter of the upper surface of the ring member is larger than the inner diameter of the region of the upper surface of the vehicle body member to which the vehicle body is connected.

5. 5. The strut mount according to claim 4, wherein the outer diameter of the upper surface of the ring member is larger than the outer diameter of the lower surface.

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