Vibration preventing unit

Abstract

To provide a vibration preventing unit capable of suppressing the fall-off of a stopper and the occurrence of abnormal sound.SOLUTION: A vibration preventing unit 10 has a first protruded part 18 provided on an outside member 13 and inserted into a first mounting hole 31a of a stopper 30. A first fixing member 40 larger than the first mounting hole 31a is mounted to the front end of the first protruded part 18, whereby the stopper 30 is fixed to a vibration preventing device 11. This suppresses the fall-off of the stopper 30 from the vibration preventing device 11. The stopper 30 is held between the first fixing member 40 and the outside member 13 to suppress the movement of the stopper 30, thus suppressing the occurrence of abnormal sound along with the movement of the stopper 30.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vibration isolation unit, and particularly to a vibration isolation unit capable of suppressing the dropping of a stopper and the generation of abnormal noise.

Background Art

[0002] Conventionally, a vibration isolation unit that suppresses vibration transmission while connecting a power unit side such as an engine and a vehicle body side is known. Some of these vibration isolation units include a vibration isolation device in which a shaft-shaped inner member and a cylindrical outer member are connected by an elastic vibration isolation base, and an elastic stopper attached to the vibration isolation device. For example, the inner member is attached to the power unit side, and the outer member is attached to the vehicle body side.

[0003] The stopper of Patent Document 1 is for buffering the collision between both axial ends of the outer member and a bracket on the power unit side attached to the inner member. The stopper is attached to the inner member by fitting both axial ends of the inner member into mounting holes penetrating the stopper in the plate thickness direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above prior art, since only the axial end of the inner member is fitted into the mounting hole of the stopper, there is a problem that the stopper is likely to drop off the inner member during transportation of the vibration isolation unit before the inner member is fixed to the bracket. In addition, due to vibrations of a vehicle equipped with the vibration isolation unit, etc., the stopper may move, and there is a possibility that knocking sounds (abnormal noises) between the stopper and surrounding members may occur.

[0006] The present invention has been made to solve the above-described problems, and an object thereof is to provide a vibration isolation unit that can suppress the dropping off of a stopper and the generation of abnormal noise.

Means for Solving the Problems

[0007] To achieve this object, the vibration isolation unit of the present invention includes a vibration isolation device in which an outer peripheral surface of an axially-shaped inner member and an inner peripheral surface of a cylindrical outer member are connected by a vibration isolation base made of an elastic body, an elastic body stopper having a first mounting hole into which a first convex portion provided on the inner member or the outer member is inserted, and a first fixing member attached to a tip of the first convex portion and fixing the stopper to the vibration isolation device by being larger than the first mounting hole. The stopper is sandwiched between the first fixing member and the inner member or the outer member having the first convex portion.

Effects of the Invention

[0008] According to the vibration isolation unit described in claim 1, the first convex portion provided on the inner member or the outer member is inserted into the first mounting hole of the stopper. By attaching a first fixing member larger than the first mounting hole to the tip of the first convex portion, the stopper is fixed to the vibration isolation device. Thereby, dropping off of the stopper from the vibration isolation device can be suppressed during transportation of the vibration isolation unit or the like.

[0009] Further, since the stopper is sandwiched between the first fixing member and the inner member or the outer member having the first convex portion, movement of the stopper can be suppressed in response to vibrations of a vehicle to which the vibration isolation unit is attached or the like. Thereby, generation of abnormal noise accompanying the movement of the stopper can be suppressed.

[0010] According to the vibration isolation unit described in claim 2, in addition to the effects achieved by the vibration isolation unit described in claim 1, the following effects are achieved. In the portion where the stopper is sandwiched between the first fixing member and the inner member or the outer member having the first convex portion, the dimension between the first fixing member and the inner member or the outer member is the same as the thickness of the stopper in the unloaded state. Thereby, the stopper can be sandwiched between the first fixing member and the inner member or the outer member with almost no compressive deformation of the stopper. As a result, the operation of attaching the first fixing member to the first convex portion can be facilitated.

[0011] According to the vibration isolation unit described in claim 3, in addition to the effects achieved by the vibration isolation unit described in claim 1, the following effects are achieved. The first fixing member is a mass member for adjusting the resonance frequency of the inner member or the outer member having the first convex portion. By using such a mass member as the first fixing member, the stopper can be fixed to the vibration isolation device, so that the structure of the vibration isolation unit can be simplified and the cost increase associated with providing the first fixing member can be suppressed.

[0012] According to the vibration isolation unit described in claim 4, in addition to the effects achieved by the vibration isolation unit described in any one of claims 1 to 3, the following effects are achieved. The stopper includes a peripheral surface portion that covers a part of the outer peripheral surface of the outer member in the circumferential direction, and a first mounting hole is provided in this peripheral surface portion. When fixing such a stopper to the inner member, due to the relative displacement between the inner member and the outer member accompanying the deformation of the vibration isolation base, the stopper may be stretched and deformed, and the durability of the stopper may be reduced. On the other hand, by attaching the first fixing member to the first convex portion protruding from the outer peripheral surface of the outer member and fixing the stopper to the outer member, the above-mentioned stretching deformation of the stopper basically does not occur, so that the durability of the stopper can be improved.

[0013] According to the vibration isolation unit described in claim 5, in addition to the effects achieved by the vibration isolation unit described in claim 4, the following effects are achieved. The stopper includes a pair of end faces that project radially inward from both axial ends of the circumferential face and cover a part of the axial end face of the outer member. Due to such a pair of end faces and the circumferential face, the circumferential cross-section of the stopper is formed in a U-shape, so that the rigidity of the stopper can be ensured. As a result, it is possible to suppress the stopper from deforming radially away from the outer peripheral surface of the outer member at a position circumferentially away from the fixed position (near the first mounting hole) of the vibration isolation device and the stopper. Consequently, it is possible to make it difficult to generate a knocking sound associated with the re-contact between the outer peripheral surface of the outer member and the stopper.

[0014] According to the vibration isolation unit described in claim 6, in addition to the effects achieved by the vibration isolation unit described in claim 4, the following effects are achieved. The stopper is provided with a first mounting hole on one end side in the circumferential direction and a second mounting hole on the other end side in the circumferential direction. A second convex portion that is inserted into the second mounting hole projects from the outer peripheral surface of the outer member. By attaching a second fixing member that is larger than the second mounting hole to the tip of the second convex portion, the second mounting hole side of the stopper is fixed to the outer member. As a result, it is possible to suppress the stopper from vibrating so as to rotate about the fixed position by the first fixing member as a fulcrum by the second fixing member. Therefore, it is possible to suppress the generation of a knocking sound associated with the vibration.

[0015] According to the vibration isolation unit described in claim 7, in addition to the effects achieved by the vibration isolation unit described in claim 6, the following effects are achieved. The stopper includes a pair of circumferentially extending portions that extend from the circumferential face to the other end side in the circumferential direction and are axially separated from each other in the outer member, and a pair of axially extending portions that are respectively bridged over the pair of circumferentially extending portions and are circumferentially separated from each other. The portion surrounded by the pair of circumferentially extending portions and the pair of axially extending portions is the second mounting hole. In this way, the other end side (near the second mounting hole) of the stopper is formed in a ladder shape. As a result, when attaching the stopper to the outer member, after inserting the first convex portion into the first mounting hole provided on one end side in the circumferential direction of the circumferential face, it is possible to easily insert the second convex portion into the second mounting hole while extending the ladder-shaped other end side. Therefore, the work of attaching the stopper to the outer member can be facilitated.

[0016] According to the vibration isolation unit described in claim 8, in addition to the effects achieved by the vibration isolation unit described in claim 6, the following effects are achieved. The second fixing member is a mass member for adjusting the resonance frequency of the outer member. By diverting such a mass member, the stopper can be fixed to the outer member, so that the structure of the vibration isolation unit can be simplified and the cost increase associated with providing the second fixing member can be suppressed.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0018] Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. FIG. 1 shows a vibration isolation unit 10 in the first embodiment. FIG. 2 is an exploded perspective view of the vibration isolation unit 10. FIG. 3 is a cross-sectional view of the vibration isolation unit 10 perpendicular to the axis C of the inner member 12. FIG. 4 is an end face view of the cut portion of the vibration isolation unit 10 along line IV-IV of FIG. 3.

[0019] The arrows U, D, L, R, F, and B in each drawing indicate the upward, downward, leftward, rightward, forward, and backward directions of the vibration isolation unit 10, respectively. Note that the up-down direction, left-right direction, and front-back direction of this vibration isolation unit 10 do not necessarily coincide with the up-down direction, left-right direction, and front-back direction of the vehicle on which the vibration isolation unit 10 is mounted.

[0020] As shown in FIG. 1, the vibration isolation unit 10 is an engine mount that suppresses vibration transmission while connecting a power unit (not shown) such as an engine or a motor and a vehicle body (not shown). The vibration isolation unit 10 includes a vibration isolation device 11 that connects the power unit side and the vehicle body side, a stopper 30 that covers a part of the vibration isolation device 11, and a first fixing member 40 and a second fixing member 50 for fixing the stopper 30 to the vibration isolation device 11.

[0021] The vibration isolation device 11 includes a shaft-shaped inner member 12, a cylindrical outer member 13 that surrounds the outer peripheral side of the inner member 12, and a vibration isolation base 14 that connects the outer peripheral surface of the inner member 12 and the inner peripheral surface of the outer member 13. The vibration isolation base 14 is composed of an elastic body such as rubber or thermoplastic elastomer, and connects the inner member 12 and the outer member 13 at four locations in the circumferential direction.

[0022] The inner member 12 is a cylindrical member made of a rigid material such as a steel material or an aluminum alloy. The axial direction of the inner member 12 coincides with the front-rear direction of the vibration isolation device 11. The inner peripheral surface of the inner member 12 is circular with the axis C as the center in a cross section perpendicular to the axis C of the inner member 12. The outer peripheral surface of the inner member 12 is formed in a substantially hexagonal shape in a cross section perpendicular to the axis C.

[0023] As shown in FIG. 4, the inner member 12 is connected to the power unit side via a bracket 60. The bracket 60 includes a pair of side portions 61 facing each other in the plate thickness direction and a connecting portion 62 that connects the pair of side portions 61. This connecting portion 62 is fixed to the power unit side.

[0024] The inner member 12 is sandwiched in the front-rear direction (axial direction) by the pair of side portions 61, and the connecting portion 62 is located on the upper left side with respect to the outer member 13. In this state, a bolt 64 is inserted into the through hole 63 provided in the side portion 61 and the inner peripheral side of the inner member 12, and a nut 65 is fastened to the bolt 64, so that the inner member 12 is fixed to the bracket 60.

[0025] 2 and 3, the outer member 13 includes a cylindrical portion 15 to which the vibration-isolating base 14 is connected, a cylindrical thick-tube portion 16 into which the cylindrical portion 15 is press-fitted, and a fixing portion 17 for fixing the thick-tube portion 16 to the vehicle body. The cylindrical portion 15 is a cylindrical member centered on the axis C, and is made of a rigid material such as steel or aluminum alloy. The vibration-isolating base 14 is vulcanization-bonded to the inner peripheral surface of the cylindrical portion 15 and the outer peripheral surface of the inner member 12.

[0026] The thick cylinder portion 16 is a cylindrical member made of an aluminum alloy and formed to be thicker than the cylindrical portion 15. The axial dimensions of the thick cylinder portion 16 and the cylindrical portion 15 are approximately the same as each other and are smaller than the axial dimension of the inner member 12. Both axial end faces of the inner member 12 are located axially outboard of both axial end faces of the thick cylinder portion 16 and the cylindrical portion 15.

[0027] A first protrusion 18 protrudes upward from the upper side of the outer circumferential surface of the thick-tube portion 16. The first protrusion 18 is a cylindrical portion having a screw hole 18a that opens to the tip (upper end). Two first protrusions 18 are provided side by side in the front-rear direction.

[0028] A substantially rectangular parallelepiped second protrusion 19 protrudes leftward from the lower left side of the outer circumferential surface of the thick cylindrical portion 16. Two screw holes 19a are opened at the tip (left end) of the second protrusion 19, side by side in the front-rear direction.

[0029] The fixing portion 17 is molded integrally with the thick cylindrical portion 16 so as to protrude downward and to the right from the outer circumferential surface of the thick cylindrical portion 16. A bracket 60 is fixed to the vehicle body by a plurality of threaded portions 17a provided on the fixing portion 17.

[0030] 2 and 4, the stopper 30 is intended to cushion a collision between the outer member 13 and the bracket 60 when the outer member 13 and the bracket 60 are displaced relative to each other due to deformation of the vibration-isolating base 14. The stopper 30 is made of an elastic body such as rubber or a thermoplastic elastomer.

[0031] The stopper 30 includes a circumferential surface portion 31 that covers a part of the outer circumferential surface of the outer member 13 (cylindrical wall thickness portion 16) in the circumferential direction, a pair of end surface portions 32 that project radially inward (toward the axis C) from both end edges of the circumferential surface portion 31 in the front-rear direction, a pair of circumferential extension portions 33 that extend in the circumferential direction from the circumferential surface portion 31 and are separated from each other in the front-rear direction, and a pair of axial extension portions 34 that are respectively bridged over the pair of circumferential extension portions 33 and are separated from each other in the circumferential direction.

[0032] The circumferential surface portion 31 is a plate-shaped portion that covers a predetermined upper left range of the outer circumferential surface of the outer member 13. That is, the circumferential surface portion 31 is provided at a portion where the outer member 13 and the bracket 60 face each other in the radial direction. With this circumferential surface portion 31, it is possible to buffer the collision when the outer member 13 and the bracket 60 are displaced relative to each other in the radial direction.

[0033] A substantially circular first mounting hole 31a is formed to penetrate vertically through one end side (upper end side) in the circumferential direction of the circumferential surface portion 31. The first mounting hole 31a is formed to be slightly larger than the first convex portion 18, that is, it is formed to have a size into which the first convex portion 18 can be inserted. Two first mounting holes 31a are provided side by side in the front-rear direction so that two first convex portions 18 arranged side by side in the front-rear direction can be respectively inserted.

[0034] The end surface portion 32 is a plate-shaped portion that covers the upper left portion of the axial end surface of the outer member 13. That is, the end surface portion 32 is provided at a portion where the outer member 13 and the bracket 60 face each other in the front-rear direction (axial direction). With this end surface portion 32, it is possible to buffer the collision when the outer member 13 and the bracket 60 are displaced relative to each other in the front-rear direction.

[0035] The pair of circumferential extension portions 33 respectively extend parallel from the circumferential surface portion 31 to the other end side (lower side) in the circumferential direction. The pair of axial extension portions 34 are respectively bridged parallel to the lower end of this circumferential extension portion 33 and the substantially center in the circumferential direction of the circumferential extension portion 33. With these pair of circumferential extension portions 33 and pair of axial extension portions 34, the other end side (lower end side) in the circumferential direction of the stopper 30 is formed in a ladder shape.

[0036] Further, in the stopper 30, a substantially rectangular second mounting hole 35 is formed by a portion surrounded by a pair of circumferential extension portions 33 and a pair of axial extension portions 34. The second mounting hole 35 is formed to be slightly larger than the second convex portion 19, that is, it is formed to have a size into which the second convex portion 19 can be inserted.

[0037] Since the vicinity of the second mounting hole 35 of the stopper 30 is ladder-shaped, it is more likely to deform compared to the circumferential surface portion 31 and the end surface portion 32. Therefore, when attaching the stopper 30 to the outer member 13, after inserting the first convex portion 18 into the first mounting hole 31a on the upper end side of the stopper 30, while stretching the vicinity of the ladder-shaped second mounting hole 35, it becomes easier to insert the second convex portion 19 into the second mounting hole 35. Therefore, the work of attaching the stopper 30 to the outer member 13 can be facilitated.

[0038] In the state where the stopper 30 is attached to the outer member 13 in this way, by attaching the first fixing member 40 and the second fixing member 50 to the outer member 13, the stopper 30 is fixed to the outer member 13.

[0039] As shown in FIGS. 1 and 2, the first fixing member 40 is a substantially rectangular parallelepiped member made of a rigid material such as a steel material or an aluminum alloy. Flanges 41 project from the centers in the vertical direction on the front and rear surfaces of the first fixing member 40, respectively.

[0040] The flange 41 is a plate-like portion perpendicular to the vertical direction, and a through hole 42 is formed in the center. By overlapping the flange 41 on the tip of the first convex portion 18 and fitting a bolt 46 inserted into the through hole 42 into the screw hole 18a of the first convex portion 18, the first fixing member 40 is attached to the outer member 13.

[0041] Since the first fixing member 40 is sufficiently larger than the first mounting hole 31a into which the first convex portion 18 is inserted, it becomes difficult for the first convex portion 18 to come out of the first mounting hole 31a. That is, the vicinity of the first mounting hole 31a of the stopper 30 is fixed to the outer member 13 by the first fixing member 40. Thereby, the detachment of the stopper 30 from the vibration isolator 11 can be suppressed during transportation when the vibration isolation unit 10 is not attached to the vehicle body side or the power unit side.

[0042] Particularly in this embodiment, since the first fixing member 40 is attached so as to be bridged over the two first convex portions 18, it is possible to make it more difficult for the first convex portion 18 to come out of the first mounting hole 31a. As a result, it is possible to further suppress the detachment of the stopper 30 from the vibration isolator 11 during transportation or the like.

[0043] The first fixing member 40 is a mass member for adjusting the resonance frequency of the outer member 13 to which it is attached, and extends vertically from the flange 41 to ensure mass. With the first fixing member 40 that utilizes such a mass member, the stopper 30 can be fixed to the outer member 13, so that the structure of the vibration isolation unit 10 can be simplified and the cost increase associated with providing the first fixing member 40 can be suppressed.

[0044] As shown in FIGS. 1 and 3, with the stopper 30 fixed to the outer member 13 by the first fixing member 40, the stopper 30 is sandwiched between the lower surface 43 of the first fixing member 40 and the outer peripheral surface of the outer member 13. Thereby, it is possible to suppress the movement of the stopper 30 in response to vibrations of the vehicle to which the vibration isolation unit 10 is attached. Specifically, it is possible to suppress the stopper 30 from vibrating up and down along the first convex portion 18 and the stopper 30 from sliding along the outer peripheral surface of the outer member 13. As a result, it is possible to suppress the generation of knocking sounds and rubbing sounds between the stopper 30 and the vibration isolator 11, the first fixing member 40, etc.

[0045] In the portion where the stopper 30 is sandwiched in this way, the dimension W between the lower surface 43 of the first fixing member 40 and the outer peripheral surface of the outer member 13 is the same as the thickness of the stopper 30 in the unloaded state. Note that this "same" is not limited to the case of being exactly the same. Considering errors and the like, the case where the difference between the dimension W and the thickness of the stopper 30 in the unloaded state is 1 mm or less is referred to as "same". Also, the case where the thickness of the stopper 30 in the unloaded state is 0 to +1 mm with respect to the dimension W may be defined as "same" so that the stopper 30 surely contacts both the first fixing member 40 and the outer member 13.

[0046] Due to this dimensional relationship, the stopper 30 can be sandwiched between the first fixing member 40 and the outer member 13 with almost no compressive deformation of the stopper 30. As a result, when fitting the bolt 46 into the screw hole 18a of the first convex portion 18, it is possible to make it difficult to generate a reaction force accompanying the compressive deformation of the stopper 30, and the operation of attaching the first fixing member 40 to the first convex portion 18 can be facilitated.

[0047] The lower surface 43 of the first fixing member 40 curves along the outer peripheral surface of the outer member 13 toward the center in the left - right direction. The dimension W between this curved lower surface 43 and the outer peripheral surface of the outer member 13 is formed to be substantially constant over the circumferential direction. Thereby, when the stopper 30 is sandwiched between the lower surface 43 and the outer peripheral surface of the outer member 13, their contact area can be ensured. As a result, the movement of the stopper 30 in response to vibrations of the vehicle or the like can be more suppressed, and the generation of abnormal noise caused by the movement can be more suppressed.

[0048] Also, the entire first fixing member 40 including the curved lower surface 43 is formed symmetrically about the left - right direction. Therefore, even if the first fixing member 40 is reversed left - right and attached to the outer member 13, the stopper 30 can be sandwiched between the lower surface 43 and the outer peripheral surface of the outer member 13. Thereby, when attaching the first fixing member 40 to the outer member 13, it is not necessary to confirm the left - right orientation of the first fixing member 40, so the attachment operation can be facilitated.

[0049] The stopper 30 at the portion fixed to the outer member 13 by the first fixing member 40 has a U - shaped cross - section in the circumferential direction by the circumferential surface portion 31 and a pair of end surface portions 32. Further, over a predetermined range in the circumferential direction from this fixed position, the circumferential cross - section of the stopper 30 is formed in a U - shape, and the rigidity of the stopper 30 is ensured. Thereby, it is possible to suppress the stopper 30 from deforming radially away from the outer peripheral surface of the outer member 13 at a position circumferentially away from the above - mentioned fixed position (near the first mounting hole 31a). As a result, it is possible to make it difficult to generate a knocking sound accompanying the re - contact between the outer peripheral surface of the outer member 13 and the stopper 30.

[0050] The second fixing member 50 is a rod-shaped member made of a rigid material such as a steel material or an aluminum alloy. The second fixing member 50 includes a plate portion 51 extending in the front-rear direction and perpendicular to the left-right direction, and substantially octagonal weight portions 52 provided at both the front and rear ends of the plate portion 51, respectively.

[0051] Two through holes 53 arranged in the front-rear direction are formed in the plate portion 51. The plate portion 51 is overlapped with the tip of the second convex portion 19, and two bolts 56 respectively inserted into the through holes 53 are fitted into the screw holes 19a of the second convex portion 19, whereby the second fixing member 50 is attached to the outer member 13.

[0052] Since the second fixing member 50 is sufficiently larger than the second mounting hole 35 into which the second convex portion 19 is inserted, it is difficult for the second convex portion 19 to come out of the second mounting hole 35. That is, the vicinity of the second mounting hole 35 of the stopper 30 is fixed to the outer member 13 by the second fixing member 50. Thereby, the detachment of the stopper 30 from the vibration isolator 11 can be further suppressed during transportation of the vibration isolation unit 10 or the like.

[0053] In the vibration isolation unit 10, the upper end side in the circumferential direction of the stopper 30 is fixed by the first fixing member 40, and the lower end side in the circumferential direction is fixed by the second fixing member 50. Thereby, the second fixing member 50 can suppress the stopper 30 from vibrating so as to rotate about the fixing position by the first fixing member 40 as a fulcrum. Therefore, the generation of knocking noise accompanying the vibration can be suppressed.

[0054] The vicinity of the second mounting hole 35 of the stopper 30 is sandwiched between the second fixing member 50 and the outer peripheral surface of the outer member 13. Thereby, the second fixing member 50 can further suppress the stopper 30 from vibrating so as to rotate about the fixing position by the first fixing member 40 as a fulcrum.

[0055] Also, as described above, the lower end side in the circumferential direction of the stopper 30 fixed by the second fixing member 50 is ladder-shaped and thus is easily deformed. When the stopper 30 is deformed, it is easy to absorb the deformation in this ladder-shaped portion, and it is possible to suppress the deformation of the circumferential surface portion 31 and the end surface portion 32 that mainly have a buffering function. As a result, it is possible to suppress fluctuations in the buffering characteristics and the generation of abnormal noises due to the deformation of the stopper 30.

[0056] The second fixing member 50 is a mass member for adjusting the resonance frequency of the outer member 13 to which it is attached, and a weight portion 52 is provided to ensure mass. Since the stopper 30 can be fixed to the outer member 13 by the second fixing member 50 that utilizes such a mass member, the structure of the vibration isolation unit 10 can be simplified, and an increase in cost associated with providing the second fixing member 50 can be suppressed.

[0057] Next, a second embodiment will be described with reference to FIG. 5. In the first embodiment, the case where the stopper 30 is fixed to the outer member 13 was described. In contrast, in the second embodiment, the case where the stopper 80 is fixed to the inner member 12 will be described. Note that the same parts as those in the first embodiment are denoted by the same reference numerals, and the following description thereof will be omitted.

[0058] FIG. 5 is an end face view of a cut portion of the vibration isolation unit 70 in the second embodiment, and the end face of the cut portion at the same position as in FIG. 4 is shown. The vibration isolation unit 70 includes a vibration isolation device 71 that connects the power unit side and the vehicle body side, a stopper 80 that covers a part of the vibration isolation device 71, and a first fixing member 90 for fixing the stopper 80 to the vibration isolation device 71.

[0059] The vibration isolation device 71 is the same as the vibration isolation device 11 in the first embodiment, except that the first convex portion 18 and the second convex portion 19 are omitted from the outer member 13, and a first convex portion 72 is provided on the inner member 12.

[0060] The first convex portion 72 protrudes from the outer peripheral surfaces of the inner members 12 on both sides in the front-rear direction with respect to the vibration isolation base 14, respectively, toward the connection portion 62 side of the bracket 60. The first convex portion 72 is a cylindrical portion in which a threaded hole 73 opening at the tip is formed.

[0061] The stopper 80 is obtained by omitting the first mounting hole 31a, the second mounting hole 35, the circumferential extension portion 33, and the axial extension portion 34 from the stopper 30 in the first embodiment, and includes a circumferential surface portion 31 and a pair of end surface portions 32. Further, the stopper 80 includes an extension portion 81 extending radially inward (toward the axis C) from a part in the circumferential direction of the end surface portion 32, and a bent portion 82 bent substantially perpendicularly outward in the axial direction (front-rear direction) from the radially inner edge of the extension portion 81. The stopper 80 is formed symmetrically in the front-rear direction.

[0062] The bent portion 82 is a plate-like portion that is overlapped near the first convex portion 72 on the outer peripheral surface of the inner member 12, and a substantially circular first mounting hole 83 is formed through in the plate thickness direction. The first mounting hole 83 is formed to be one size larger than the first convex portion 72, that is, it is formed to have a size into which the first convex portion 72 can be inserted.

[0063] The first fixing member 90 is for fixing the stopper 80 to the inner member 12 by attaching it to the tip of the first convex portion 72 inserted into the first mounting hole 83. The first fixing member 90 is a plate-like member made of a rigid material such as a steel material or an aluminum alloy.

[0064] A through hole 91 is formed in the center of the first fixing member 90. By overlapping the first fixing member 90 on the tip of the first convex portion 72 and fitting a screw 93 inserted into the through hole 91 into the screw hole 73 of the first convex portion 72, the first fixing member 90 is attached to the inner member 12.

[0065] Since the first fixing member 90 is sufficiently larger than the first mounting hole 83 into which the first convex portion 72 is inserted, it is difficult for the first convex portion 72 to come out of the first mounting hole 83. That is, the first fixing member 90 fixes the vicinity of the first mounting hole 83 of the stopper 80 to the inner member 12. Thereby, it is possible to suppress the detachment of the stopper 80 from the vibration isolator 71 during transportation or the like when the vibration isolation unit 70 is not attached to the vehicle body side or the power unit side.

[0066] Furthermore, the bent portion 82 of the stopper 80 is sandwiched between the first fixing member 90 and the outer peripheral surface of the inner member 12. Thereby, it is possible to suppress the movement of the stopper 80 in response to vibrations of the vehicle to which the vibration isolation unit 70 is attached. As a result, it is possible to suppress the generation of knocking sounds and rubbing sounds between the stopper 80 and the vibration isolator 71, the first fixing member 90, and the like.

[0067] In the portion where the bent portion 82 of the stopper 80 is sandwiched in this way, the dimension between the first fixing member 90 and the outer peripheral surface of the inner member 12 is the same as the thickness of the bent portion 82 in the unloaded state. Due to this dimensional relationship, the bent portion 82 can be sandwiched between the first fixing member 90 and the inner member 12 with almost no compression deformation of the bent portion 82. As a result, similar to the first embodiment, the operation of attaching the first fixing member 90 to the first convex portion 72 can be facilitated.

[0068] In a state where the stopper 80 is fixed to the inner member 12 by the first fixing member 90 and in the unloaded state of the vibration isolation unit 70, the peripheral surface portion 31 of the stopper 80 is radially separated from the outer peripheral surface of the outer member 13. Thereby, when a load is input to the vibration isolation unit 70 and the vibration isolation base 14 is deformed, and the outer member 13 is displaced relative to the inner member 12 toward the connecting portion 62 side, if the amount of displacement is small, the outer member 13 can be prevented from hitting the stopper 80. Therefore, it is possible to suppress the radial elongation and deformation of the stopper 80 accompanying this displacement, and the durability of the stopper 80 can be ensured.

[0069] On the other hand, in the vibration isolation unit 10 of the first embodiment, a stopper 30 that covers a part of the outer peripheral surface of the outer member 13 is fixed to the outer member 13. Therefore, in the first embodiment, since the elongation deformation of the stopper 30 accompanying the relative displacement basically does not occur, the durability of the stopper 30 can be improved.

[0070] As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above embodiments at all, and it can be easily inferred that various improvements and modifications are possible without departing from the spirit of the present invention. For example, the shapes, dimensions, and materials of each part of the vibration isolation devices 11 and 71, the stoppers 30 and 80, the first fixing members 40 and 90, the second fixing member 50, and the bracket 60 are just examples, and it is natural to adopt various shapes, dimensions, and materials.

[0071] For example, the inner member 12 may be formed in a cylindrical shape, or may be formed in a columnar shape, a prismatic shape, or the like. In this specification, the cylindrical shape and the columnar shape are collectively referred to as an axial shape. According to the shape of the inner member 12, the fixing method between the inner member 12 and the bracket 60 can be appropriately changed. Further, the cylindrical portion 15 of the outer member 13 may be omitted, and the vibration isolation base 14 may be directly connected to the inner peripheral surface of the cylinder thickness portion 16.

[0072] The connection between the inner member 12 and the outer member 13 is not limited to the case where they are connected at four locations in the circumferential direction by the vibration isolation base 14, and they may be connected at three or less locations or five or more locations. Further, the inner member 12 and the outer member 13 may be connected by the vibration isolation base 14 over the entire circumference.

[0073] In the above embodiment, the case where the inner member 12 is fixed to the power unit side via the bracket 60 and the outer member 13 is fixed to the vehicle body side has been described. However, it is not necessarily limited to this. The inner member 12 may be fixed to the vehicle body side via the bracket 60, and the outer member 13 may be fixed to the power unit side.

[0074] In the above-described first embodiment, the case where the first fixing member 40 and the second fixing member 50 are mass members for adjusting the resonance frequency of the outer member 13 has been described, but it is not necessarily limited to this. The first fixing member 40 or the second fixing member 50 may be constituted by a stay that connects the outer member 13 and the vehicle body, or a stay for attaching a harness (various wirings). Further, the first fixing member 90 attached to the inner member 12 as in the second embodiment may be a mass member for adjusting the resonance frequency of the inner member 12, or may be each stay.

[0075] In the above-described first embodiment, the case where the first fixing member 40 is formed symmetrically about the left and right has been described, but it is not necessarily limited to this, and it may be asymmetric about the left and right. For example, the lower surface 43 of the first fixing member 40 may be curved along the outer peripheral surface of the outer member 13 over the entire left-right direction. Thereby, when the stopper 30 is sandwiched between the lower surface 43 and the outer member 13, their contact area can be made wider. As a result, the movement of the stopper 30 in response to vibrations of the vehicle or the like can be further suppressed, and the generation of abnormal noise caused by the movement can be further suppressed.

[0076] In the above-described first embodiment, the case where the vicinity of the second mounting hole 35 of the stopper 30 is sandwiched between the second fixing member 50 and the outer member 13 has been described, but it is not necessarily limited to this. For example, the dimensions may be adjusted so that the stopper 30 is not sandwiched between the second fixing member 50 and the outer member 13.

[0077] In the above-described first embodiment, the case where the stopper 30 includes the circumferential extension portion 33 and the axial extension portion 34 has been described, but it is not necessarily limited to this. These may be omitted from the stopper 30, and the second mounting hole 35 may be formed to penetrate the circumferential surface portion 31. Further, the circumferential extension portion 33, the axial extension portion 34, the second mounting hole 35, the second convex portion 19, and the second fixing member 50 may be omitted. That is, the stopper 30 may be fixed to the outer member 13 only by the first fixing member 40.

Explanation of Reference Numerals

[0078] 10, 70 Vibration Isolation Unit 11,71 Vibration isolation device 12 Inner member 13 Outer member 14 Vibration isolation base 18,72 First convex portion 19 Second convex portion 30,80 Stopper 31 Peripheral surface portion 31a,83 First mounting hole 32 End surface portion 33 Extended portion 34 Axially extended portion 35 Second mounting hole 40,90 First fixing member 50 Second fixing member

Claims

1. A vibration isolation device in which an outer peripheral surface of a shaft-shaped inner member and an inner peripheral surface of a cylindrical outer member are connected by a vibration isolation base made of an elastic body, An elastic stopper having a first mounting hole into which a first convex portion provided on the inner member or the outer member is inserted, A first fixing member attached to a tip of the first convex portion and fixing the stopper to the vibration isolation device by being larger than the first mounting hole, and The stopper is sandwiched between the first fixing member and the inner member or the outer member having the first convex portion. A vibration isolation unit characterized by that.

2. In a portion where the stopper is sandwiched between the first fixing member and the inner member or the outer member having the first convex portion, a dimension between the first fixing member and the inner member or the outer member is the same as a thickness of the stopper in a no-load state. The vibration isolation unit according to claim 1, characterized by that.

3. The first fixing member is a mass member for adjusting a resonance frequency of the inner member or the outer member having the first convex portion. The vibration isolation unit according to claim 1, characterized by that.

4. The stopper includes a peripheral surface portion that covers a part in the circumferential direction of an outer peripheral surface of the outer member and in which the first mounting hole is provided, The first convex portion protrudes from an outer peripheral surface of the outer member. The vibration isolation unit according to any one of claims 1 to 3, characterized by that.

5. The stopper includes a pair of end surface portions that project radially inward from both axial end edges of the peripheral surface portion and cover a part of an axial end surface of the outer member. The vibration isolation unit according to claim 4, characterized by that.

6. The first mounting hole is provided on one end side in the circumferential direction of the peripheral surface portion, and a second mounting hole is provided on the other end side in the circumferential direction of the stopper, From an outer peripheral surface of the outer member, a second convex portion to be inserted into the second mounting hole protrudes, A second fixing member larger than the second mounting hole is attached to a tip of the second convex portion, whereby the second mounting hole side of the stopper is fixed to the outer member. The vibration isolation unit according to claim 4, characterized by that.

7. The first mounting hole is provided on one end side in the circumferential direction of the peripheral surface portion, The stopper includes a pair of circumferentially extending portions that extend from the peripheral surface portion to the other end side in the circumferential direction and are separated from each other in the axial direction of the outer member, and A pair of axially extending portions that are respectively bridged over the pair of circumferentially extending portions and are separated from each other in the circumferential direction. The vibration isolation unit according to claim 6, characterized in that a portion surrounded by the pair of the circumferential extension portions and the pair of the axial extension portions is the second mounting hole.

8. The vibration isolation unit according to claim 6, characterized in that the second fixing member is a mass member for adjusting a resonance frequency of the outer member.

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