vibration isolating device

Abstract

The present application provides a kind of anti-vibration device, it does not need the mounting operation of mass block relative to support, and can efficiently adjust the inherent vibration frequency of support.Due to the mass block part (22) is formed on the outer peripheral surface (21a) of the annular part (21) arranged at the lower end side of the support (2), therefore, the mass block part (22) can be configured at the position away from the insertion hole (20c~20e) of the fulcrum of vibration of the support (2) (i.e., the region where the amplitude of the support 2 is easy to increase).Therefore, even if the mass of the mass block part (22) is small, the inherent vibration frequency of the support (2) can be greatly changed, so the inherent vibration frequency of the support (2) can be efficiently adjusted.In addition, since the mass block part (22) is integrally formed on the outer peripheral surface (21a) of the annular part (21), unlike the prior art of installing the separate mass block on the support (2) after, the mounting operation of the mass block can not be needed.

Description

Technical Field

[0001] This invention relates to vibration damping devices, and more particularly to a vibration damping device that does not require the installation of a mass block relative to a support, and can efficiently adjust the natural vibration frequency of the support. Background Technology

[0002] For example, Patent Document 1 describes a technique for mounting a dynamic shock absorber 50 on a mounting bracket 38 (support) located between a subframe 12 on the vehicle body side and a power unit P on the vibration source side. The dynamic shock absorber 50 includes: a dynamic shock absorber bracket 64 mounted on the mounting bracket 38; and a counterweight 70 (mass block) elastically supported on the dynamic shock absorber bracket 64 via an elastic connector 68. In this technique, the collar component 60 of the mounting bracket 38 and the dynamic shock absorber bracket 64 of the dynamic shock absorber 50 are fastened together by bolts 36.

[0003] Alternatively, for example, Patent Document 2 describes a technique in which a counterweight 62 is directly mounted on a mounting component 50 (bracket) located between the subframe 12 on the vehicle body side and the power unit P on the vibration source side. In this technique, the counterweight 62 is also fastened to the mounting component 50 by bolts 70.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2018-114884 (e.g., paragraphs 0011-0029, Figures 1-3 ) Patent Document 2: Japanese Patent Application Publication No. 2018-114886 (e.g., paragraphs 0012-0026) Figure 1 ) Summary of the Invention

[0005] (a) Technical problems to be solved As with the technologies in Patent Documents 1 and 2 mentioned above, in structures where the mass block is fixed to the bracket with bolts, there is a problem that the installation of the mass block is time-consuming.

[0006] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a vibration damping device that does not require the installation of a mass block relative to a support and can efficiently adjust the natural vibration frequency of the support.

[0007] (II) Technical Solution To achieve this objective, the vibration damping device of the present invention comprises: a fastening member fastened to either a vibration-bearing side or a vibration-source side; a bracket having an insertion hole formed at one end for the fastening member to be inserted from the front surface side, and a press-in hole formed at the other end side; and a vibration damping bushing installed in the press-in hole of the bracket, the vibration damping bushing comprising: an outer part cylindrically pressed into the press-in hole; an inner part disposed on the inner circumferential side of the outer part and fixed to the other of the vibration-bearing side or the vibration-source side; and an elastic body connecting the outer part and the inner part, the bracket having a mass block portion integrally formed on the outer circumferential surface opposite to the insertion hole across the press-in hole.

[0008] (III) Beneficial Effects According to the vibration damping device of the first embodiment, the bracket includes a mass block portion integrally formed on the outer peripheral surface opposite to the insertion hole, thus allowing the mass block portion to be positioned away from the insertion hole (the part for fastening the fastening component) which becomes the fulcrum of the bracket's vibration. In this way, by positioning the mass block portion in an area where the bracket's amplitude is prone to increase, even if the mass of the mass block portion is small, the natural vibration frequency of the bracket can be significantly altered. Therefore, it has the effect of efficiently adjusting the natural vibration frequency of the bracket. Furthermore, since the mass block portion is integrally formed on the bracket, unlike the prior art where a separate mass block is added to the bracket later, it eliminates the need for mass block installation work.

[0009] According to the second vibration damping device, in addition to the effects of the first vibration damping device, it also achieves the following effects: The mass block portion includes: a pair of sidewalls protruding from the outer peripheral surface of the support, and a front wall connecting the front ends of the pair of sidewalls to each other. A first weight-reducing hole surrounded by the pair of sidewalls and the front wall is formed in the mass block portion. Therefore, compared to the case where the first weight-reducing hole is not formed, the center of gravity of the mass block portion can be moved away from the fulcrum (insertion hole) of the support's vibration. Therefore, it has the effect of efficiently adjusting the natural vibration frequency of the support.

[0010] According to the third embodiment of the vibration damping device, in addition to the effects of the second embodiment, it also achieves the following effects: The mass block portion has a bottom wall that closes the first weight-reducing hole on the rear surface side of the support. The rear surface of the bottom wall is a plane orthogonal to the axial direction of the vibration damping bushing and is connected to the edge of the press-in hole. Therefore, when the vibration damping bushing is pressed into the press-in hole while the support is placed on the mounting surface of the press-in fixture, a support surface (the rear surface of the bottom wall) can be formed adjacent to the edge of the press-in hole to support the load during pressing. Thus, the support can be stably supported when the vibration damping bushing is pressed in, thereby improving the workability of the press-in vibration damping bushing operation.

[0011] According to the fourth embodiment of the vibration damping device, in addition to the effects of the third embodiment, it also has the following effects: The bracket has multiple second weight-reducing holes formed around the insertion hole. Since the second weight-reducing holes are not formed on the rear surface of the bracket, when inserting a pin erected from the mounting surface of the aforementioned press-fit clamp from the rear side relative to the insertion hole, the insertion hole to be inserted can be easily determined. Therefore, it has the effect of improving the workability of pressing in the vibration damping bushing.

[0012] According to the fifth vibration damping device, in addition to the effects of the second vibration damping device, it also achieves the following effects: One sidewall of the pair of sidewalls is partially bent from one end to the other axially along the vibration damping bushing, while the other sidewall is straight from one end to the other axially. One sidewall has higher rigidity than the other. Therefore, when a load accompanying vibration is input to the support, the location of stress concentration can be easily predicted in advance. Thus, it facilitates the strength design of the support.

[0013] According to the sixth embodiment of the vibration damping device, in addition to the effects of the second embodiment, it also has the following effects. Regarding the protrusion height of the pair of sidewalls protruding from the outer peripheral surface of the support, compared with the two ends of the axially upward sidewalls of the vibration damping bushing, the central portion of the axially upward sidewalls is formed to be the highest. Therefore, when there are mating parts around the mass block, it can suppress the mass block from interfering with the mating parts.

[0014] According to the seventh embodiment of the vibration damping device, in addition to the effects of the first embodiment, because the support has an annular portion formed to surround the press-in hole, and a mass block portion integrally formed on the outer circumferential surface of the annular portion, when a load caused by the displacement of the inner component of the vibration damping bushing is input to the support, the stress caused by the load tends to concentrate at the boundary between the mass block portion and the annular portion. By pre-forming such a stress-concentrated area as an annular portion, the strength design of the support (annular portion) can be easily performed.

[0015] The installation structure of the vibration damping device in the eighth scheme is a structure that installs the vibration damping device of the seventh scheme between the vibration-bearing side and the vibration-source side. When viewed from the input direction of the load from the vibration-bearing side or the vibration-source side, the mass block is positioned overlapping with the inner component. Therefore, the load from the vibration-bearing side or the vibration-source side easily acts on the boundary between the mass block and the annular portion. Consequently, the stress caused by this load is more easily concentrated at the boundary between the mass block and the annular portion, thus making it easier to design the strength of the support (annular portion).

[0016] According to the installation structure of the vibration damping device in the ninth embodiment, in addition to the effects of the installation structure of the vibration damping device in the eighth embodiment, since the end of the circumferential mass block portion of the annular portion and the boundary of the outer circumferential surface of the annular portion are arranged to overlap with the inner component when viewed from the load input direction, loads from the vibration bearing side or the vibration source side are more likely to act on the boundary portion between the mass block portion and the annular portion. As a result, the stress caused by this load is more likely to concentrate at the boundary portion between the mass block portion and the annular portion, thus making it easier to design the strength of the support (annular portion).

[0017] According to the installation structure of the vibration damping device in the tenth scheme, in addition to the effects of the installation structure of the vibration damping device in the eighth scheme, the following effects are also achieved: When viewed in the load input direction, one end of the circumferential mass block of the annular portion is positioned at a point overlapping with the boundary of the outer circumferential surface of the annular portion, while the other end of the circumferential mass block of the annular portion is positioned at a point not overlapping with the boundary of the outer circumferential surface of the annular portion. Therefore, the load is easily applied only to one end of the circumferential mass block of the annular portion and the boundary of the outer circumferential surface of the annular portion, thus making it easier to design the strength of the support (annular portion). Attached Figure Description

[0018] Figure 1 This is a front view of a vibration damping device according to an embodiment of the present invention.

[0019] Figure 2 It is along Figure 1 A cross-sectional view of the vibration damping device on line II-II.

[0020] Figure 3 (a) is along Figure 1 A partially enlarged cross-sectional view of the vibration damping device on Line IIIa-IIIa. Figure 3 (b) is along Figure 1 A partially enlarged cross-sectional view of the vibration damping device for the IIIb-IIIb line.

[0021] Figure 4 This is a 3D view of the rear surface of the support.

[0022] Explanation of reference numerals in the attached figures 1: Vibration damping device; 2: Bracket; 20c~20e: Insertion hole; 20f: Weight reduction hole (second weight reduction hole); 21: Annular part; 21a: Outer peripheral surface of the annular part; 21b: Press-in hole; 22: Mass block part; 22a, 22b: Side wall; 22c: Front end wall; 22d: Bottom wall; 220d: Rear surface of the bottom wall; 22e: Weight reduction hole (first weight reduction hole); 3: Vibration damping bushing; 30: Outer cylinder (outer component); 31: Inner cylinder (inner component); 32: Elastomer; 4: Bolt (fastening component); B1, B2: Boundary between the outer peripheral surface of the mass block part and the annular part; O: Shaft. Detailed Implementation

[0023] The preferred embodiments will now be described with reference to the accompanying drawings. First, refer to... Figure 1 and Figure 2 The overall structure of vibration damping device 1 is described. Figure 1 This is a front view of a vibration damping device 1 according to an embodiment of the present invention. Figure 2 It is along Figure 1 The cross-sectional view of the vibration damping device 1 on line II-II shows the vibration damping device 1 in the unloaded state without input vibration (load).

[0024] In addition, Figure 1 and Figure 2 The outlines of the mounting components 100 and 101, on which the vibration damping device 1 is installed, are schematically illustrated using double-dotted lines. Figure 1 To simplify the accompanying drawings, bolts 4 and 5, which fasten the mounting components 100 and 101, are omitted (see reference). Figure 2 The illustration is shown below. Additionally... Figure 1 and Figure 2 The arrows UD, FB, and LR represent the up-down, front-back, and left-right directions of the vibration damping device 1, respectively (and the same applies in later diagrams). However, the directions of the vibration damping device 1 may not be consistent with the directions of the vehicle on which it is installed.

[0025] like Figure 1 and Figure 2 As shown, the vibration damping device 1 is an engine mount that elastically supports the vehicle engine. The vibration damping device 1 includes: a metal bracket 2, which is mounted on the engine (vibration source) side with a mounting component 100; and a vibration damping bushing 3, which is mounted on the vehicle body (vibration bearing) side with a mounting component 101.

[0026] The bracket 2 includes: a main body 20, which is secured by bolts 4 (see reference). Figure 2The main body 20 is fixed to the mounting component 100; a ring-shaped portion 21 in the shape of a circular ring (semi-circular ring) is formed on the lower end side (arrow D side) of the main body 20; a mass block portion 22 is formed on the outer peripheral surface 21a of the ring portion 21, and these portions 20-22 are integrally formed.

[0027] The main body 20 has a front surface 20a and a rear surface 20b that penetrate it (regarding the rear surface 20b, see...). Figure 2 Multiple insertion holes 20c~20e (Regarding insertion hole 20e, refer to...) Figure 1 In addition, a plurality of weight-reducing holes 20f are formed (distributed) uniformly throughout (and substantially uniformly distributed) on the front surface 20a of the main body 20. These weight-reducing holes 20f are recesses used to ensure formability (flowability of the casting within the mold, etc.) when the various parts 20 to 22 of the support 2 are integrally formed by casting.

[0028] Of the multiple insertion holes 20c to 20e, the insertion hole formed at the uppermost side (arrow U side) of the bracket 2 is insertion hole 20c, and the insertion holes formed below insertion hole 20c are insertion holes 20d and 20e. The main body 20 of the bracket 2 is further downward than these insertion holes 20c to 20e. Figure 1 Extending from the lower right side, a ring-shaped portion 21 is formed at the lower end of the main body portion 20.

[0029] A circularly shaped press-in hole 21b is formed on the inner circumferential side of the annular portion 21 (see reference). Figure 1 A vibration damping bushing 3 is installed in the press-in hole 21b. In the following description, the axis O direction of the vibration damping bushing 3 in the state of being pressed into the press-in hole 21b will be simply referred to as "axis O direction".

[0030] The vibration damping bushing 3 has a cylindrical outer cylinder 30 (outer part) that is pressed into the press-in hole 21b (see reference). Figure 1 A cylindrical inner cylinder 31 (inner component) is disposed on the inner circumference of the outer cylinder 30. Both the outer cylinder 30 and the inner cylinder 31 are metal components. An elastomer 32 (see reference) is vulcanized and bonded to the inner circumferential surface of the outer cylinder 30 and the outer circumferential surface of the inner cylinder 31. Figure 1 The outer cylinder 30 and the inner cylinder 31 are connected by the elastomer 32.

[0031] By inserting the bolt 5 into the inner cylinder 31 of the anti-vibration bushing 3 (refer to...) Figure 2 The bolts 4 (see reference) are fastened to the mounting component 101 and inserted into the insertion holes 20c~20e of the bracket 2 (main body 20). Figure 2 The vibration damping device 1 is fastened to the mounting component 100, thereby installing the vibration damping device 1 between the mounting components 100 and 101. In this embodiment, the axis O direction in this installation state is taken as the front-rear direction of the vibration damping device 1 (arrow FB direction) for explanation.

[0032] When viewed from the front-back direction (axis O direction) of the vibration damping device 1, among the insertion holes 20c~20e, the direction connecting the center of the insertion hole 20c, which is located furthest from the pressing hole 21b (upper end side), and the center of the pressing hole 21b is the long side direction of the bracket 2 (vibration damping device 1). Furthermore, the direction orthogonal to the long side direction and the front-back direction of the bracket 2 is the short side direction.

[0033] With the vibration damping device 1 installed, the long side of the bracket 2 is inclined relative to the vertical direction (arrow UD direction), and the insertion holes 20c~20e are positioned off-center to one side (arrow R side in this embodiment) relative to the center (axis O) of the insertion hole 21b. Furthermore, a pair of insertion holes 20d and 20e are spaced apart along the short side of the bracket 2, and the size of the bracket 2 (main body 20) in the short side direction gradually increases from the area where the insertion hole 20c is formed to the area where the insertion holes 20d and 20e are formed.

[0034] The dimension of the bracket 2 in the short side direction is the largest in the region where the insertion holes 20d and 20e are formed. When this largest dimension is taken as the width dimension of the bracket 2, the thickness of the bracket 2 in the front-back direction (the direction orthogonal to the long side direction and the short side direction) is made smaller than the width dimension of the bracket 2. Of course, the dimension in the long side direction is made larger than the width dimension of the bracket 2.

[0035] The press-in hole 21b is formed at a distance from the insertion holes 20c~20e along the long side of the bracket 2. When the vibration damping device 1 is installed, the press-in hole 21b is positioned below the insertion holes 20c~20e (vertically lower side). The outer peripheral surface 21a of the annular portion 21 surrounding approximately half of the press-in hole 21, except for the area where the mass block portion 22 is formed, is an arcuate surface centered on axis O. Hereinafter, the direction around the outer peripheral surface 21a of this annular portion 21 will be simply referred to as the "circumferential direction". The mass block portion 22 formed on the outer peripheral surface 21a of the annular portion 21 is a part configured as a mass body for adjusting the natural vibration frequency of the bracket 2.

[0036] Thus, the vibration damping device 1 of this embodiment has the following structure: the upper end (one end in the long side direction) of the bracket 2 is fixed (rigidly connected) to the mounting component 100 by bolts 4, and the lower end (the other end in the long side direction) is elastically supported on the mounting component 101 via a vibration damping bushing 3 (elastic body 32). Therefore, when vibration is input to the bracket 2, the vibration is easily constrained on the upper end of the bracket 2, while the lower end of the bracket 2 can achieve more free vibration compared to the upper end. That is, when the vibration is input, the upper end of the bracket 2 acts as a fulcrum for vibration, therefore, the amplitude of the lower end of the bracket 2 is easily increased.

[0037] In this embodiment, since a mass block 22 is formed on the outer peripheral surface 21a of the annular portion 21 located at the lower end of the support 2 (on the side opposite to the insertion holes 20c-20e, separated by the press-in hole 21b), the mass block 22 can be positioned away from the fulcrum of vibration of the support 2 (insertion holes 20c-20e). Thus, by positioning the mass block 22 in the area where the amplitude of the support 2 is easily increased, even if the mass of the mass block 22 is small, the natural vibration frequency of the support 2 can be significantly altered, thereby enabling efficient adjustment of the natural vibration frequency of the support 2.

[0038] Furthermore, since the mass block portion 22 (mass body) used to adjust the inherent vibration frequency of the bracket 2 is integrally formed on the outer peripheral surface 21a of the annular portion 21, unlike the prior art of adding a separate mass block to the bracket 2 later, the installation of the mass block is not required.

[0039] The mass block portion 22 has a pair of sidewalls 22a, 22b protruding downward from the outer peripheral surface 21a of the annular portion 21 (outer peripheral side of the annular portion 21). (Regarding the sidewall 22a, see...) Figure 1 The protruding directions of the pair of sidewalls 22a and 22b are approximately parallel to each other. The protruding length of sidewall 22a from the outer peripheral surface 21a of the annular portion 21 is formed to be longer than the protruding length of sidewall 22b (see reference). Figure 1 The front ends (lower ends) of a pair of sidewalls 22a and 22b are connected to each other in the circumferential direction (arrow LR direction) via the front end wall 22c.

[0040] The rear ends of a pair of sidewalls 22a, 22b and the front end wall 22c Figure 1 The ends of the support 2 (vertically inward) are connected to each other via bottom wall 22d, thereby forming a weight-reducing hole 22e surrounded by these walls 22a-22d on the front surface of the mass block portion 22. That is, the weight-reducing hole 22e is a recess that is closed by bottom wall 22d from the rear surface side of the support 2. This weight-reducing hole 22e is a recess used to ensure the formability of the support 2, which mainly includes the walls 22a-22d of the mass block portion 22, when integrally formed by casting.

[0041] While the weight-reducing hole 22e can be omitted to form the mass block 22, the formability of the casting support 2 is easily reduced when the mass block 22 is formed into a simple cuboid shape by filling in the weight-reducing hole 22e, for example. Furthermore, considering forming the mass block 22 with the same mass (volume), in the structure where the weight-reducing hole 22e is omitted, the center of gravity of the mass block 22 is close to the fulcrum of the support 2's vibration (insertion holes 20c~20e). If the center of gravity of the mass block 22 is close to the fulcrum of the support 2's vibration, then even if the mass of the mass block 22 is changed, the natural vibration frequency of the support 2 cannot be significantly adjusted.

[0042] In this embodiment, the mass block portion 22 includes a pair of sidewalls 22a and 22b protruding from the outer peripheral surface of the support 2, and a front end wall 22c connecting the front ends of the pair of sidewalls 22a and 22b to each other. A weight-reducing hole 22e surrounded by these walls 22a-22c is formed in the mass block portion 22. Therefore, as described above, compared to a structure omitting the weight-reducing hole 22e, the center of gravity of the mass block portion 22 can be moved away from the fulcrum of the support 2's vibration. Thus, by changing the mass of the mass block portion 22, the natural vibration frequency of the support 2 can be efficiently adjusted.

[0043] Here, if engine vibration and vehicle vibration accompanying vehicle movement are input to the vibration damping device 1, the bracket 2 (annular portion 21) and the inner cylinder 31 of the vibration damping bushing 3 will displace relative to each other, and the load Fa accompanying the displacement of the inner cylinder 31 will be... Figure 1 The load in the direction indicated by arrow Fa (hereinafter referred to as "load Fa") acts on support 2. The input direction of this load Fa is mainly orthogonal to axis O, and is inclined at an angle of 20 to 40° (30° in this embodiment) relative to the vertical direction.

[0044] In other words, the load Fa mainly acts in a direction roughly aligned with the long side of the support 2. Therefore, stress caused by the load Fa is generated on the main body 20 and the annular portion 21 located on both sides of the long side of the support 2, separated by the press-in hole 21b. The wall thickness of the main body 20 is thicker (compared to the annular portion 21), while the annular portion 21 is thinner (a flat plate with a roughly constant thickness). Therefore, if the load Fa is repeatedly applied to the support 2, fatigue failure is more likely to occur primarily in the annular portion 21.

[0045] In particular, in this embodiment, since the mass block portion 22 is integrally formed on the annular portion 21, the boundary portions B1 and B2 between the circumferential ends of the mass block portion 22 (the sides of the pair of sidewalls 22a, 22b) and the outer peripheral surface 21a of the annular portion 21 (refer to...) Figure 1 The stress caused by the load Fa tends to concentrate. This is because the annular portion 21 in the region without the mass block 22 has lower rigidity compared to the region where the mass block 22 is formed (between boundaries B1 and B2).

[0046] Therefore, if the load Fa, which is accompanied by vehicle vibration, is repeatedly applied to the bracket 2, it is easy for failure to occur starting from the boundary B1, B2 between the annular portion 21 and the mass block portion 22. In this way, by pre-forming the stress concentration (failure-prone) area in the annular portion 21, the strength design of the bracket 2 (annular portion 21) can be easily carried out.

[0047] Furthermore, among these boundaries B1 and B2, boundary B1 is the boundary between one circumferential end of the mass block portion 22 (the end on the side of arrow L) and the outer peripheral surface 21a of the annular portion 21. On the other hand, boundary B2 is the boundary between the other circumferential end of the mass block portion 22 (the end on the side of arrow R) and the outer peripheral surface 21a of the annular portion 21.

[0048] Additionally, the input direction of the load Fa acting on the support 2 is observed ( Figure 1 (Observed from the direction indicated by the middle arrow Fa), the mass block portion 22 and the inner cylinder 31 are positioned in an overlapping position. Therefore, the load Fa, which is associated with vehicle vibration, is easily applied to the boundaries B1 and B2 between the annular portion 21 and the mass block portion 22. Consequently, the stress caused by the load Fa is easily concentrated at the boundaries B1 and B2 between the annular portion 21 and the mass block portion 22, making it easier to design the strength of the bracket 2.

[0049] Furthermore, in this embodiment, among the boundaries B1 and B2 of the annular portion 21 and the mass block portion 22, when viewed from the input direction of the load Fa, one boundary B1 (on the sidewall 22a side) is positioned overlapping with the inner cylinder 31. Therefore, the load Fa is more likely to act on one boundary B1. Consequently, the stress caused by the load Fa is more likely to concentrate at the boundary B1 between the annular portion 21 and the mass block portion 22, thus making it easier to design the strength of the support 2.

[0050] Furthermore, among the boundaries B1 and B2 of the annular portion 21 and the mass block portion 22, when viewed from the input direction of the load Fa, the other boundary B2 (on the sidewall 22b side) is positioned where it does not overlap with the inner cylinder 31. Therefore, the load Fa is easily applied to only one boundary B1. As a result, the strength design of the support 2 can be made even easier.

[0051] Next, refer to Figure 3 and Figure 4 The detailed structure of the mass block 22 is described, but references are also made as appropriate. Figure 1 and Figure 2 Please provide an explanation. Figure 3 (a) is along Figure 1 A partially enlarged cross-sectional view of the vibration damping device 1 on line IIIa-IIIa. Figure 3 (b) is along Figure 1 A partially enlarged cross-sectional view of the vibration damping device 1 for line IIIb-IIIb. Figure 4 This is a three-dimensional view of the rear surface of bracket 2. Furthermore, in Figure 4 The diagram shows the state of the anti-vibration bushing 3 being removed from the press-in hole 21b of the bracket 2.

[0052] like Figure 3 and Figure 4As shown, a cross-sectional view cut by a plane orthogonal to the projection directions of the pair of sidewalls 22a, 22b (see reference). Figure 3 In (a), the sidewall 22b extends in a roughly straight line along the front-back direction (axis O direction) (arrow FB direction), while the sidewall 22a is partially curved.

[0053] More specifically, the sidewall 22a has a first wall portion 220a forming its front end (the end on the side of arrow F), and a second wall portion 221a is connected to the rear end (the end on the side of arrow B) of the first wall portion 220a extending in the front-to-back direction (in the direction of arrow FB). The second wall portion 221a bends from the first wall portion 220a in a circumferentially inward direction (inward in the opposite direction of the sidewalls 22a and 22b), and a third wall portion 222a is connected to the end of the second wall portion 221a in a circumferentially inward direction.

[0054] The third wall portion 222a extends rearward (towards arrow B) from the second wall portion 221a and connects to the bottom wall 22d. The thicknesses of the wall portions 220a to 222a constituting the side wall 22a are approximately constant.

[0055] The sidewall 22a is formed by bending the wall portions 220a to 222a, and a recess 22f is formed on the side of the mass block portion 22 (sidewall 22a) that is recessed inward toward the circumferential direction towards the mass block portion 22. This recess 22f is mainly used to prevent interference with the surrounding mating parts (other parts assembled in the vehicle) of the bracket 2. In addition, by bending a portion of the sidewall 22a as described above, a first recess 220e with a shallower depth and a second recess 221e with a deeper depth than the first recess 220e are formed in the circumferential direction at the weight reduction hole 22e, starting from the front surface of the mass block portion 22 (the surface facing the arrow F side).

[0056] Thus, in this embodiment, a portion of sidewall 22a is bent from the front end to the rear end, while sidewall 22b is formed as a straight line from front to back. This structure allows sidewall 22a to have higher rigidity than sidewall 22b. That is, a rigidity difference can be created between the pair of sidewalls 22a and 22b. Furthermore, this structure also allows for the boundary B1 and B2 (refer to...) between the annular portion 21 and the mass block portion 22. Figure 1 In one boundary B1, the boundary line between the annular portion 21 and the mass block portion 22 can be bent, while in another boundary B2, the boundary line between the annular portion 21 and the mass block portion 22 can be straightened.

[0057] As described above, by creating a rigidity difference between the pair of sidewalls 22a and 22b, or by setting the boundary line between the annular portion 21 and the pair of sidewalls 22a and 22b to a different shape, the load Fa (refer to) accompanying the vehicle's vibration can be controlled. Figure 1When the input is fed into the support 2, it is easy to predict in advance the boundaries B1 and B2 between the annular portion 21 and the mass block portion 22 (refer to...). Figure 1 Which boundary sections B1 and B2 in the structure are prone to stress concentration (and thus failure)? Therefore, the strength design of support 2 can be easily performed.

[0058] Regarding the protrusion height of the sidewall 22a protruding from the outer peripheral surface 21a of the annular portion 21, it is highest in the central portion in the front-rear direction compared to the front and rear ends of the sidewall 22a (see reference). Figure 3 (b)), the sidewall 22b is also formed in the same shape (see reference). Figure 2 That is, the pair of sidewalls 22a and 22b are tapered towards the lower end (arrow D side). Therefore, the front surface 223a of the sidewall 22a (first wall portion 220a) and the bottom surface of the first recess 220e of the weight reduction hole 22e are inclined in a manner that approaches the center side of the mass block portion 22 in the front-rear direction as it moves towards its lower end (see reference). Figure 3 (b)

[0059] Furthermore, the front end wall 22c, which connects the lower ends of the side walls 22a and 22b in the circumferential direction, is also inclined away from the annular portion 21 from the rear end side (bottom wall 22d side) to the front end side (see reference). Figure 3 (b) By forming the mass block portion 22 in such a shape that tapers towards the lower end, interference between the mass block portion 22 and the mating member can be suppressed when there is a mating member around (before and after) the mass block portion 22.

[0060] Here, the outer cylinder 30 of the vibration damping bushing 3 (refer to...) Figure 3 When pressing the bracket 2 into the insertion hole 21b, a pressing jig (not shown) is used. This pressing jig has a mounting surface for mounting the bracket 2. The pressing jig has a plurality of (e.g., three) pins that stand upright from the mounting surface. When the bracket 2 is placed on the mounting surface, the plurality of pins of the pressing jig are inserted into the insertion holes 20c~20e from the rear surface 20b side of the bracket 2 (see reference). Figure 4 ).

[0061] The vibration damping device 1 is assembled by inserting the vibration damping bushing 3 (outer cylinder 30) into the press-in hole 21b in the inserted state of the pin. Therefore, for example, if the mass block portion 22 is not formed on the outer peripheral surface 21a of the annular portion 21, it is difficult to form a support surface (the surface supported on the mounting surface of the press-in clamp) around the annular portion 21 to support the load when the vibration damping bushing 3 is pressed into the press-in hole 21b.

[0062] In this embodiment, a mass block portion 22 is formed on the outer peripheral surface 21a of the annular portion 21. Therefore, the mass block portion 22 can form a support surface for pressing the vibration damping bushing 3 into the press-in hole 21b. In particular, the rear surface 220d of the bottom wall 22d of the mass block portion 22 in this embodiment (refer to...) Figure 4 The plane 220d is orthogonal to the direction of axis O and is connected to the edge of the press-in hole 21b. By supporting the rear surface 220d of the bottom wall 22d by the press-in fixture, the load during the press-in of the vibration damping bushing 3 can be supported at the position adjacent to the annular portion 21 (press-in hole 21b). Therefore, the vibration damping bushing 3 can be pressed in while the bracket 2 is stably placed on the mounting surface of the press-in fixture, thereby improving the workability of the press-in operation of the vibration damping bushing 3.

[0063] In addition, as described above, a plurality of weight-reducing holes 20f are formed on the front surface 20a of the support 2 (see reference). Figure 1 or Figure 2 However, on the rear surface 20b of the support 2 (refer to...) Figure 4 The weight-reducing hole is not formed. Therefore, the operator can easily determine the insertion holes 20c~20e of the pin to be inserted into the press-fit fixture, thus allowing the bracket 2 to be easily installed on the press-fit fixture. Therefore, the workability of pressing in the vibration-damping bushing 3 (outer cylinder 30) is improved.

[0064] The present invention has been described above based on the above embodiments, but the present invention is not limited to any of the above methods. It is easy to infer that various modifications and improvements can be made without departing from the spirit of the present invention.

[0065] In the above embodiment, an engine mount is exemplified as the application object of the vibration damping device 1, but its application object is arbitrary. Other application objects may include, for example, motor mounts, component mounts, differential mounts, etc. Furthermore, it is not limited to the case where the bracket 2 is installed on the vibration source side of the engine, etc., and the vibration damping bushing 3 is installed on the vibration bearing side of the vehicle body, etc. It is also possible to install the vibration damping bushing 3 on the vibration source side and the bracket 2 on the vibration bearing side.

[0066] In the above embodiment, the case where the weight-reducing hole 22e, surrounded by side walls 22a, 22b, front end wall 22c, and bottom wall 22d, is formed in the mass block portion 22 has been described, but it is not limited to this. For example, the weight-reducing hole 22e may be omitted, and the mass block portion 22 may be formed in a cuboid or cubic shape, or it may be formed in other polyhedral shapes. In addition, the bottom wall 22d may be omitted, and the weight-reducing hole 22e may be formed as a through hole, or other cavities (holes) or recesses may be formed in the mass block portion 22, in addition to or in place of the weight-reducing hole 22e.

[0067] That is, as long as the mass block portion 22 is integrally formed on the outer peripheral surface 21a of the annular portion 21, the shape of the mass block portion 22 can be arbitrarily changed. Therefore, for example, in the above embodiment, the case where the rear surface 220d of the bottom wall 22d (the bottom surface of the mass block portion 22) is a plane orthogonal to the axis O and connected to the edge of the press-in hole 21b has been described, but the rear surface 220d of the bottom wall 22d can also be a plane or curved surface that is not orthogonal to the axis O, and a step can also be provided between the rear surface 220d of the bottom wall 22d and the edge of the press-in hole 21b (the rear surface of the annular portion 21).

[0068] In the above embodiment, the case where a weight-reducing hole 20f is formed on the front surface 20a of the support 2, but such a weight-reducing hole is not formed on the rear surface 20b of the support 2, has been described, but it is not limited to this. For example, the weight-reducing hole 20f of the support 2 may be omitted, or the weight-reducing hole 20f may be formed on the rear surface 20b of the support 2.

[0069] In the above embodiment, the case in which a mass block portion 22 is formed on the outer peripheral surface 21a of the annular portion 21 surrounding the press-in hole 21b has been described, but it is not limited to this. For example, the shape of the outer peripheral surface 21a of the annular portion 21 may be appropriately changed (it may not be formed as an annular shape), and multiple mass block portions 22 may be integrally formed on the outer peripheral surface 21a of the annular portion 21.

[0070] In the above embodiment, the explanation of the definition of the boundaries B1 and B2 between the annular portion 21 and the mass block portion 22 is omitted. However, for example, if the curved surface that connects the outer peripheral surface 21a of the annular portion 21 and the side surface of the mass block portion 22 (side walls 22a and 22b) is defined as the connecting surface, the midpoint of the connecting surface is the boundary B1 and B2 between the annular portion 21 and the mass block portion 22.

[0071] In the above embodiment, the case where, when viewed in the input direction of load Fa, one boundary B1 is formed at a position overlapping with the inner cylinder 31 (when viewed in the same direction, it is formed at a position overlapping with the inner cylinder 31) of the boundaries B1 and B2 of the annular portion 21 and the mass block portion 22, has been described, but it is not limited to this. For example, when viewed in the input direction of load Fa, the other boundary B2 may also be formed at a position overlapping with the inner cylinder 31, and both boundaries B1 and B2 may be formed at positions overlapping with the inner cylinder 31.

[0072] Furthermore, when viewed from the input direction of the load Fa, the mass block portion 22 can also be formed in a position that does not overlap with the inner cylinder 31. That is, the arrangement and size of the mass block portion 22 in the circumferential direction of the annular portion 21 are not limited to the above-described manner and can be appropriately modified.

Claims

1. A vibration damping device, characterized in that, have: Fastening components are fastened to either the vibration-bearing side or the vibration-source side; The bracket has an insertion hole formed at one end for the fastening member to be inserted from the front surface side, and a press-in hole formed at the other end; and Vibration damping bushing, which is installed in the press-in hole of the bracket. The vibration damping bushing has the following features: The outer component is cylindrical and is pressed into the press-in hole; An inner component, disposed on the inner periphery of the outer component, and fixed to either the vibration-bearing side or the vibration-source side; and An elastomer that connects the outer component and the inner component. The bracket has a mass block portion integrally formed on the outer peripheral surface opposite to the insertion hole, separated from the press-in hole.

2. The vibration damping device according to claim 1, characterized in that, The mass block portion includes: a pair of sidewalls protruding from the outer peripheral surface of the support, and a front wall connecting the front ends of the pair of sidewalls to each other. A first weight-reducing hole is formed in the mass block portion, and the first weight-reducing hole is surrounded by a pair of sidewalls and the front end wall.

3. The vibration damping device according to claim 2, characterized in that, The mass block portion has a bottom wall, which closes the first weight reduction hole on the rear surface side of the bracket. The rear surface of the bottom wall is a plane orthogonal to the axial direction of the vibration damping bushing and is a plane connected to the edge of the press-in hole.

4. The vibration damping device according to claim 3, characterized in that, The bracket has a plurality of second weight-reducing holes formed around the insertion hole. The second weight-reducing hole is not formed on the rear surface of the bracket.

5. The vibration damping device according to claim 2, characterized in that, One of the pair of sidewalls has a portion bent from one end of the vibration damping bushing in the axial direction to the other, while the other sidewall is straight from one end of the axial direction to the other. One of the sidewalls is more rigid than the other sidewall.

6. The vibration damping device according to claim 2, characterized in that, Regarding the protrusion height of the pair of sidewalls projecting from the outer peripheral surface of the bracket, the central portion of the sidewalls in the axial direction is formed to be the highest compared to the two ends of the sidewalls in the axial direction of the vibration damping bushing.

7. The vibration damping device according to claim 1, characterized in that, The bracket has an annular portion, which is formed in a ring shape surrounding the press-in hole, and the mass block portion is integrally formed on the outer peripheral surface of the annular portion.

8. An installation structure for a vibration damping device, characterized in that, The vibration damping device according to claim 7 is installed between the vibration-bearing side and the vibration-source side. When viewed from the input direction of the load from the vibration-bearing side or the vibration-source side, the mass block is positioned to overlap with the inner component.

9. The installation structure of the vibration damping device according to claim 8, characterized in that, When viewed in the direction of the load input, the end of the mass block portion in the circumferential direction of the annular portion and the boundary of the outer circumferential surface of the annular portion are positioned to overlap with the inner component.

10. The installation structure of the vibration damping device according to claim 8, characterized in that, Viewed from the input direction of the load, one end of the mass block portion in the circumferential direction of the annular portion is positioned at a point overlapping with the boundary of the outer circumferential surface of the annular portion. When viewed in the direction of the load input, the other end of the mass block portion in the circumferential direction of the annular portion is positioned at a location that does not overlap with the inner component, along with the boundary of the outer circumferential surface of the annular portion.

Images