Vibration isolation device

Abstract

A vibration isolation device (1) in which a cover member (17) is arranged between an inner side mounting member (11) and an outer cylinder (12), the cover member (17) covering a pair of middle elastomers (32) adjacent to each other in a circumferential direction from an outer side in a radial direction, a pair of liquid chambers (14a, 14b) being divided between the cover member (17) and the inner side mounting member, a hole passage (19) that communicates each of the pair of liquid chambers with each other is formed between the cover member and the outer cylinder, a first communication opening (18) and a second communication opening (20) that respectively communicate each of the pair of liquid chambers and the hole passage are formed in the cover member, and an injection hole (12a) formed in the outer cylinder and sealed by a seal member (16) is opened toward at least one of the first communication opening and the second communication opening.

Description

Technical Field

[0001] This invention relates to a vibration isolation device.

[0002] This application claims priority based on Japanese Patent Application No. 2020-171736, filed in Japan on October 12, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] The vibration isolation device comprises: an inner mounting member connected to either the vibration generating part or the vibration receiving part, and an outer cylinder connected to and surrounding the inner mounting member of either the vibration generating part or the vibration receiving part; and an elastic body that elastically connects the inner mounting member and the outer cylinder.

[0004] As such a vibration isolation device, for example as shown in Patent Document 1 below, a structure is known as follows: the elastic body has a pair of intermediate elastic bodies arranged radially on both sides separated by an inner mounting member, a covering member is arranged between the inner mounting member and the outer cylinder, the covering member covers the pair of intermediate elastic bodies that are adjacent to each other in the circumferential direction from the radially outer side, a pair of liquid chambers are formed between the covering member and the inner mounting member, and a hole passage is formed between the covering member and the outer cylinder to communicate with each of the liquid chambers of the pair of liquid chambers.

[0005] One known method for sealing a liquid in a liquid chamber is as follows: the liquid chamber is set to a low pressure lower than atmospheric pressure, liquid is injected into the liquid chamber through an injection hole formed in the outer cylinder, and then a sealing element such as a rivet is fitted into the injection hole.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-86099 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] In the conventional vibration isolation devices, there may be cases where the seal protrudes radially inward from the inner circumference of the outer cylinder, and the periphery of the injection hole in the outer cylinder undergoes plastic deformation radially inward. The seal and the deformed portion may come into contact with components such as a covering member disposed on the inner side of the outer cylinder.

[0011] The present invention was made with regard to such a situation, and its purpose is to provide a vibration isolation device capable of suppressing the contact between the seal and a component disposed on the inner side of the outer cylinder.

[0012] Solution for solving the problem

[0013] The vibration isolation device of the first aspect of the present invention comprises: an inner mounting member connected to either a vibration generating part or a vibration receiving part, and an outer cylinder connected to and surrounding the inner mounting member and either the vibration generating part or the vibration receiving part; and an elastic body that elastically connects the inner mounting member and the outer cylinder, the elastic body including a middle elastic body, which, in a top view viewed axially along the central axis of the outer cylinder, is respectively disposed on both sides of the inner mounting member in a radial direction intersecting the central axis, and a covering member is disposed between the inner mounting member and the outer cylinder. In the top view, the covering member covers the circumferentially adjacent intermediate elastic bodies from the radially outer side between each other along the central axis. A pair of liquid chambers are formed between the covering member and the inner mounting member. An orifice is formed between the covering member and the outer cylinder to communicate with each of the liquid chambers of the pair. A first communication opening and a second communication opening are formed on the covering member to communicate with each of the liquid chambers of the pair and the orifice, respectively. An injection hole formed in the outer cylinder and sealed by a seal opens toward at least one of the first communication opening and the second communication opening.

[0014] The effects of the invention

[0015] According to the vibration isolation device of the present invention, it is possible to suppress the contact between the seal and other components disposed on the inner side of the outer cylinder. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the vibration isolation device at its central axial position, as an embodiment of the present invention.

[0017] Figure 2 yes Figure 1 The vibration isolation device shown is viewed in a sectional view along line II-II.

[0018] Figure 3 yes Figure 1 The vibration isolation device shown is viewed in a sectional view along line III-III.

[0019] Figure 4 Is Figure 1 The image shows a view along line IV of the vibration isolation device with the outer cylinder removed.

[0020] Figure 5 Is Figure 1 The image shows a V-line view of the vibration isolation device with the outer cylinder removed.

[0021] Figure 6 Is Figure 1 The VI line view shows the vibration isolation device with the outer cylinder removed.

[0022] Figure 7 Is Figure 1 The vibration isolation device shown is viewed along line VII with the outer cylinder removed.

[0023] Figure 8 Is Figure 1 The image shows a line view (VIII) of the vibration isolation device, viewed from the front with the outer cylinder removed, showing the first connecting opening.

[0024] Figure 9 Is Figure 1 The IX-line view is taken from the front of the second connecting opening in the vibration isolation device shown, with the outer cylinder removed.

[0025] Figure 10 Is Figure 4 and Figure 5 The side view of the vibration isolation device shown is taken from the front, with the outer cylinder and the covering components removed, and observed from the front.

[0026] Figure 11 Is Figure 6 and Figure 7 The side view of the elastic body in the vibration isolation device shown is taken from the front with the outer cylinder and the covering components removed. Detailed Implementation

[0027] The following is for reference Figures 1 to 11 This invention describes one embodiment of the vibration isolation device.

[0028] The vibration isolation device 1 of this embodiment includes: an inner mounting member 11 connected to either the vibration generating part or the vibration receiving part, and an outer cylinder 12 connected to the other of the vibration generating part and the vibration receiving part and surrounding the inner mounting member 11; and elastic bodies 31 and 32 that elastically connect the inner mounting member 11 and the outer cylinder 12.

[0029] Vibration isolation device 1 is used, for example, as a suspension bushing for automobiles, an engine mount, or a bracket for industrial machinery installed in a factory.

[0030] Hereinafter, the direction along the central axis O of the outer cylinder 12 will be referred to as the axial direction, the direction intersecting the central axis O in the top view viewed from the axial direction will be referred to as the radial direction, and the direction of rotation around the central axis O will be referred to as the circumferential direction. In the axial direction, the side with the central portion of the vibration isolation device 1 will be referred to as the inner side, and the side away from the central portion of the vibration isolation device 1 will be referred to as the outer side.

[0031] like Figure 1 and Figure 2 As shown, the inner mounting member 11 has a cylindrical spindle portion 21 and a resin portion 22 fixed to the outer peripheral surface of the spindle portion 21.

[0032] The spindle portion 21 is coaxially arranged with the central axis O. The two axial ends 21d of the spindle portion 21 protrude axially outward from the outer cylinder 12. The spindle portion 21 is non-circular when viewed axially. Two flat first chamfered portions 21b, extending continuously along the entire axial length, are formed at circumferential intervals on the outer circumferential surface of the spindle portion 21. The spindle portion 21 is non-circular when viewed axially along its entire axial length. The first chamfered portions 21b are provided on the outer circumferential surface of the spindle portion 21 at positions located radially separated from each other by the central axis O.

[0033] In the following top view viewed from the axial direction, the direction in which the two first chamfered portions 21b are opposite to each other is called one direction X, and the direction orthogonal to one direction X is called the other direction Y.

[0034] The resin portion 22 is formed of a synthetic resin material such as polyamide. The resin portion 22 is disposed on the outer peripheral surface of the mandrel portion 21, located axially inward of the axial end 21d. The resin portion 22 is disposed over the entire area of ​​the outer peripheral surface of the mandrel portion 21, excluding the axial end 21d.

[0035] The outer peripheral surface of at least the axial end of the resin portion 22 is non-circular when viewed from the axial direction.

[0036] In the illustrated example, the outer peripheral surface of the resin portion 22 is non-circular when viewed from the axial direction over its entire axial length.

[0037] The resin part 22 has a middle part 26 disposed on the outer peripheral surface of the spindle part 21 in the axial direction of the middle part and an outer part 27 extending from the middle part 26 toward the outer side in the axial direction.

[0038] The outer peripheral surface of the outer portion 27 is located radially inside the outer peripheral surface of the middle portion 26, which is located axially inside the outer portion 27.

[0039] The wall thickness of the outer portion 27 is uniform throughout the entire region. When viewed from the axial direction, the outer peripheral surface of the outer portion 27 has the same shape as the outer peripheral surface of the axial end 21d of the mandrel portion 21.

[0040] The wall thickness of the middle portion 26 is greater than that of the outer portion 27 over the entire region. The top surface of the radially outer side of the middle portion 26 extends straight along the axial direction in a longitudinal sectional view along the axial direction over its entire circumferential length. When viewed from the axial direction, the middle portion 26 has a rectangular shape that is longer in one direction X.

[0041] The short side portion 26a, extending in one direction X and the other direction Y, on the outer peripheral surface of the middle portion 26, is connected to the stop elastic portion 34, which will be described later. The short side portion 26a has a convex curve shape when viewed axially. The short side portion 26a is radially opposite to the liquid chambers 14a and 14b. The short side portion 26a is located at the outermost radial position on the outer peripheral surface of the inner mounting member 11. Alternatively, the liquid chambers 14a and 14b can be described as a pair of liquid chambers 14a and 14b.

[0042] The elastic body 32, described later, is connected to a long side portion 26b extending in one direction (X) on the outer peripheral surface of the middle portion 26. A recess 26c is formed in the long side portion 26b, concave in the other direction (Y). In the illustrated example, the recess 26c is formed over the entire area of ​​the long side portion 26b except for the two ends in the X direction, and its depth decreases as it moves away from the center along the X direction. The long side portion 26b has a concave curve shape when viewed axially. Alternatively, the recess 26c may not be formed in the long side portion 26b.

[0043] At the middle portion 26, the wall thickness of the central portion of the short side portion 26a in the other direction Y is set to be the maximum, and the wall thickness of the central portion of the long side portion 26b in the one direction X is the minimum. The connection portion between the short side portion 26a and the long side portion 26b, that is, the connection portion of the outer peripheral surface of the inner mounting member 11 that connects the portion with the stop elastic part 34 (described later) and the portion with the middle elastic body 32 (described later), bulges outward radially when viewed from the axial direction. In the illustrated example, the connection portion between the short side portion 26a and the long side portion 26b has a convex curve shape in the other direction Y when viewed from the axial direction. Alternatively, the outer diameter of the middle portion 26 can be set to be the same throughout the entire circumference.

[0044] Elastomers 31 and 32 are formed of rubber material and vulcanized and bonded to the outer peripheral surface of the inner mounting member 11. Elastomers 31 and 32 include: a pair of annular end elastomers 31, axially spaced apart and fitted within the outer cylinder 12; and a pair of intermediate elastomers 32, respectively disposed on either side of the end elastomers 31, radially separated by the inner mounting member 11. Elastomers 31 and 32 may also exclude the end elastomers 31.

[0045] The end elastomer 31 includes: an end flange portion 31a that surrounds the outer portion 27 from the radially outer side; and an end connecting portion 31b that connects the radially inner end of the end flange portion 31a to the outer peripheral surface of the inner mounting member 11.

[0046] The end flange 31a extends continuously along its entire circumferential length. The end flange 31a is coaxially arranged with the central axis O. The end flange 31a is located axially inward of the axial end of the inner mounting member 11. An annular rigid plate 33 extending circumferentially is provided in the end flange 31a. The rigid plate 33 is formed from a hard raw material such as metal or synthetic resin. The rigid plate 33 is embedded within the end flange 31a.

[0047] The end connector 31b is formed in a cylindrical shape and extends continuously along its entire circumferential length. The end connector 31b extends radially inward from the radially inner end of the end flange 31a toward either downward or upward (axially inward). The end connector 31b is connected to the axially outer end of the middle portion 26. The end connector 31b is coaxially arranged with the central axis O.

[0048] A reinforcing portion 31c is formed on the inner circumferential surface of the end elastic body 31, protruding radially inward and connecting to the outer circumferential surface of the outer portion 27. The end elastic body 31 is connected to the outer circumferential surface of the outer portion 27 by means of the reinforcing portion 31c. Two reinforcing portions 31c are provided at different circumferential positions, respectively disposed on both sides of the inner mounting member 11 in the radial direction. The reinforcing portion 31c is connected to the portion of the outer circumferential surface of the outer portion 27 that is adjacent to the central portion in one direction X of the long side portion 26b of the middle portion 26 in the axial direction.

[0049] In the inner mounting member 11, the outer peripheral surface of the outer portion 27, which is connected to the reinforcing part 31c, is located radially inner than the outer peripheral surface of the middle portion 26, and the middle portion 26 is located axially inner than the outer portion 27.

[0050] Therefore, the radial size of the reinforcing portion 31c, that is, the volume of the end elastic body 31, can be ensured to be large. Alternatively, the reinforcing portion 31c may not be formed in the end elastic body 31, and the end elastic body 31 may be connected to the outer peripheral surface of the outer portion 27 but not to the middle portion 26.

[0051] Intermediate elastomers 32 are respectively disposed on both sides radially separated by the inner mounting member 11. A pair of intermediate elastomers 32 are formed with identical shapes and sizes. The intermediate elastomers 32 are formed of rubber material over their entire area. Figure 11As shown, the intermediate elastic body 32 includes: a main portion 32a disposed at the axial center of the inner mounting member 11; and a pair of secondary portions 32b, which protrude axially outward from the main portion 32a and are smaller in volume than the main portion 32a. Both the main portion 32a and the secondary portions 32b are rectangular in shape, with one pair of sides extending circumferentially and the remaining pair of sides extending axially, as seen in a front view from the radially outer side. The circumferential size of the main portion 32a is larger than that of the secondary portions 32b. The secondary portions 32b are connected to the circumferential center of the main portion 32a. The axial outer ends of the secondary portions 32b are connected to the end elastic body 31. The radially outer surfaces of each of the main portions 32a and the secondary portions 32b are flat surfaces extending in both the transverse and axial directions orthogonal to the axial direction, as seen in a front view from the radially outer side. The outer surfaces of the main portion 32a and the secondary portions 32b are connected without any height difference.

[0052] like Figure 1 , Figure 2 as well as Figure 10 As shown, the stop elastic portions 34 protruding toward each liquid chamber 14a, 14b are respectively provided on the outer peripheral surface of the inner mounting member 11. Alternatively, the stop elastic portions 34 may not be provided on the outer peripheral surface of the inner mounting member 11. The stop elastic portions 34 are provided on the short side portion 26a of the middle portion 26. When the inner mounting member 11 and the outer cylinder 12 move closer together, the stop elastic portions 34 can abut against the inner surface of the covering member 17, which will be described later. The stop elastic portions 34 are connected to the middle elastic body 32 in the circumferential direction.

[0053] The stop elastic portion 34 is axially connected to the end connection portion 31b. The stop elastic portion 34 and the elastic bodies 31 and 32 are integrally formed of, for example, a rubber material. The outer peripheral surface of the inner mounting member 11 is covered with, for example, a rubber material over the entire area.

[0054] In the stop elastic portion 34, the outer surface of the inner portion 34a, which is located circumferentially, including the central portion and situated inside, is radially inward than the outer surface of the outer portion 34b, which is located outward and connected to the intermediate elastic body 32. Alternatively, the outer diameter of the stop elastic portion 34 can be made equal throughout its entire circumference. The inner portion 34a and the outer portion 34b are connected circumferentially along their entire axial length. The outer surface of the inner portion 34a is formed as an arc shape centered on the central axis O. The outer surface of the outer portion 34b is formed as a curved surface protruding radially outward. The axial dimensions of the outer portion 34b and the main portion 32a of the intermediate elastic body 32 are set to be equal to each other, and their axial positions are also equal.

[0055] A covering member 17 is disposed between the inner mounting member 11 and the outer cylinder 12. The covering member 17 covers the portion of the intermediate elastic bodies 32 located between each other in the circumferential direction between a pair of end elastic bodies 31 from the radial outside. Liquid chambers 14a and 14b are formed between the covering member 17 and the inner mounting member 11.

[0056] The stop elastic portion 34 is disposed between the intermediate elastic bodies 32 that are adjacent to each other in the circumferential direction, forming part of the partition wall of the liquid chambers 14a and 14b. The covering member 17 is formed of a material harder than the raw materials forming the elastic bodies 31 and 32, such as synthetic resin. The covering member 17 is fitted between a pair of end elastic bodies 31.

[0057] Liquid chambers 14a and 14b are sealed with a high-viscosity liquid with a kinematic viscosity of 50 cSt or higher and 1000 cSt or lower, preferably 500 cSt or higher and 1000 cSt or lower, at 40°C. The kinematic viscosity is measured according to JIS K2283 using a Type B viscometer (manufactured by TOKIMEC). Examples of suitable liquids include silicone oil.

[0058] Either end of the axial portion of the covering member 17 and the rigid plate 33 disposed on the end elastic body 31 are axially clamped and fixed by a fixing portion 23 formed at either end of the axial portion of the outer cylinder 12. In this embodiment, a fixing flange portion 17c is formed at one end of the covering member 17, protruding radially outward and extending circumferentially. The fixing flange portion 17c and the rigid plate 33 are axially clamped and fixed by the fixing portion 23. The fixing flange portion 17c and the radially outer end of the rigid plate 33 are axially stacked through a rubber membrane. Alternatively, the fixing flange portion 17c may not be formed on the covering member 17.

[0059] The fixing portion 23 has a circumferential groove that is recessed radially outward and extends continuously over its entire circumferential length. The fixing flange portion 17c and the rigid plate 33, together with the end flange portion 31a, fit into the circumferential groove over its entire circumferential length. The fixing portion 23 is formed by bending one end of the outer cylinder 12, and the fixing portion 23 bulges radially outward.

[0060] A support protrusion 24 is formed at one of the two axial ends of the outer cylinder 12. This support protrusion 24 protrudes radially inward and supports the other axial end of the covering member 17. The other end of the outer cylinder 12 is bent to form the support protrusion 24 into a flange shape. The support protrusion 24 supports the other end of the covering member 17 axially through the rigid plate 33. Alternatively, the support protrusion 24 may not be formed on the outer cylinder 12.

[0061] The covering member 17 is installed around the inner side of the member 11 from the radial outside over the entire circumference.

[0062] The inner surface of the covering member 17 is in liquid-tight contact with the outer surface of the intermediate elastic body 32, without contacting the stop elastic portion 34. The covering member 17 causes the intermediate elastic body 32 to compress and deform in another direction Y. The portion of the inner surface of the covering member 17 that is located between the intermediate elastic bodies 32 that are adjacent to each other in the circumferential direction and divides to form liquid chambers 14a and 14b is formed in a cross-sectional view orthogonal to the central axis O as an arc shape centered on the central axis O. A stop portion 17b is formed in the portion of the inner surface of the covering member 17 that divides to form liquid chambers 14a and 14b. The stop portion 17b protrudes radially inward and can abut against the outer surface of the inner portion 34a of the stop elastic portion 34 when the inner mounting member 11 moves closer to the outer cylinder 12.

[0063] like Figure 6 As shown, the outer peripheral surface of the covering member 17 is formed with: a main body groove 19, which divides the space between the main body groove 19 and the inner peripheral surface of the outer cylinder 12 to form a perforated passage; a first connecting opening 18, which opens into any one of the liquid chambers 14a and 14b and the main body groove 19; and a second connecting opening 20, which opens into any other liquid chamber 14b and the main body groove 19. Furthermore, the perforated passage is formed by the main body groove 19, and therefore can also be referred to as the perforated passage 19.

[0064] The first connecting opening 18 and the second connecting opening 20 are arranged in a manner that differs in axial position and is adjacent in the circumferential direction. The first connecting opening 18 and the second connecting opening 20 are respectively open at both ends of the main body groove 19 in the direction in which the main body groove 19 extends. The first connecting opening 18 and the second connecting opening 20 are arranged in a manner that is adjacent in the axial direction.

[0065] like Figure 8 and Figure 9 As shown, the first connecting opening 18 and the second connecting opening 20 are radially opposite a portion of the stop elastic portion 34. In the illustrated example, the first connecting opening 18 and the second connecting opening 20 are radially opposite one axial end of either of the two outer portions 34b of the stop elastic portion 34. Figure 10 As shown, the outer peripheral surface of one axial end of the outer portion 34b is recessed towards the radially inward side. In the illustrated example, the outer peripheral surface of one axial end of the outer portion 34b extends towards the radially inward side as it moves outward in the axial direction.

[0066] Alternatively, only one axial end of the outer portion 34b, which is radially opposite to the first communication opening 18 that opens into the injection hole 12a (described later), may be recessed radially inward. Alternatively, the outer peripheral surfaces of each portion of the stop elastic portion 34 that is radially opposite to the first communication opening 18 and the second communication opening 20 may not be recessed radially inward.

[0067] like Figure 6 and Figure 7 As shown, the main body groove 19 includes: a first groove 19a and a second groove 19b, which extend in the circumferential direction and are configured in different axial positions; and a third groove 19d, which connects the first groove 19a and the second groove 19b.

[0068] The first slot 19a and the second slot 19b each have the same circumferential length, which is longer than the third slot 19d. The first connecting opening 18 opens at one circumferential end of the first slot 19a, and the second connecting opening 20 opens at one circumferential end of the second slot 19b. The third slot 19d connects the other circumferential ends of the first slot 19a and the second slot 19b to each other. The other circumferential ends of the first slot 19a and the second slot 19b are adjacent to each other in the circumferential direction. The third slot 19d is located between the circumferentially adjacent first connecting opening 18 and second connecting opening 20.

[0069] At least a portion of the periphery of at least one of the first communicating opening 18 and the second communicating opening 20 on the outer peripheral surface of the covering member 17 is formed with a second chamfer (bevel) 17d. Alternatively, the second chamfer 17d may not be formed on the outer peripheral surface of the covering member 17.

[0070] The second chamfer 17d is formed at the periphery of both the first connecting opening 18 and the second connecting opening 20. The second chamfer 17d extends radially outward along a direction that enlarges the openings of both the first connecting opening 18 and the second connecting opening 20. The second chamfer 17d is formed in a dividing wall portion 19e that divides the wall portion forming the main body groove 19. This dividing wall portion 19e extends circumferentially and axially divides the first groove 19a and the second groove 19b.

[0071] The end wall portions 19c, which are respectively located at both ends of the main body groove 19 in the direction of extension of the main body groove 19 and extend axially, respectively divide and form a portion of the inner surface of the first communicating opening 18 and the second communicating opening 20. The circumferential size of the end wall portions 19c is equal along the entire axial length. The end wall portions 19c extend in a straight line in a direction inclined relative to both the axial and circumferential directions. Furthermore, the end wall portions 19c can be appropriately modified, for example, by adopting a structure that extends straight in the axial direction, or by adopting a structure in which the circumferential size varies from one side of the axial direction to the other.

[0072] The end wall portion 19c that divides a portion of the inner surface forming the first communication opening 18 extends axially away from the second groove 19b toward the opposite side of the first communication opening 18 in the circumferential direction. The end wall portion 19c that divides a portion of the inner surface forming the second communication opening 20 extends axially away from the first groove 19a toward the opposite side of the second communication opening 20 in the circumferential direction. The end wall portions 19c that divide a portion of the inner surface forming the first communication opening 18 and the end wall portions 19c that divide a portion of the inner surface forming the second communication opening 20 extend substantially parallel to each other. The portion sandwiched in the circumferential direction by these end wall portions 19c is the third groove 19d. That is, either the inner end face 19f of the two circumferential end faces 19f and 19g of the end wall portion 19c divides a portion of the inner surface of the first communication opening 18 or the second communication opening 20, and the outer end face 19g on the side opposite to the side where the inner end face 19f is located divides the third groove 19d.

[0073] The covering member 17 comprises a plurality of segments 15 divided in the circumferential direction, and the peripheral edges 15a of adjacent segments 15 abut against each other, making the covering member 17 as a whole cylindrical. Two segments 15 are formed with identical shapes and equal sizes, and are respectively arranged in an axially flipped state so that their peripheral edges 15a are connected to each other in the circumferential direction. In addition, the covering member 17 may also be integrally formed into a cylindrical structure.

[0074] The covering member 17 covers the elastic body 32 over its entire circumference. The peripheral edge 15a of the segment 15 is located at the central part of the elastic body 32 in the circumferential direction. The first connecting opening 18 and the second connecting opening 20 are respectively formed at the peripheral ends of the two segments 15 that are adjacent to each other in the circumferential direction.

[0075] like Figure 1 and Figure 7As shown, a first engaging portion 41 and a second engaging portion 42 are formed on the peripheral edge 15a of each abutting segment 15. The first engaging portion 41 and the second engaging portion 42 restrict the relative movement of the adjacent segment 15 in the axial and radial directions by engaging with each other. Alternatively, the first engaging portion 41 and the second engaging portion 42 may not be formed on each segment 15.

[0076] The first engaging portion 41 and the second engaging portion 42 are formed in the portion of the peripheral edge 15a of the partition body 15 located between the first groove 19a and the second groove 19b. A portion of each of the first engaging portion 41 and the second engaging portion 42 is formed in the partition wall portion 19e. The first engaging portion 41 and the second engaging portion 42 are disposed on the opposite side of the third groove 19d, which is radially separated from the inner mounting member 11.

[0077] The first engaging portion 41 is a convex portion protruding circumferentially from the peripheral edge 15a of one segment 15. The second engaging portion 42 is a circumferentially recessed portion formed on the peripheral edge 15a of another segment 15. The second engaging portion 42 does not open on the radially inward inner surface of the covering member 17, but rather on the outer peripheral surface of the partition wall portion 19e. The first engaging portion 41 is fitted into the second engaging portion 42.

[0078] A third engaging portion 43 and a fourth engaging portion 44 are formed on the peripheral edge 15a of each abutting segment 15, respectively. The third engaging portion 43 and the fourth engaging portion 44 restrict the relative axial and radial movement of the adjacent segment 15 in the circumferential direction by engaging with each other. Alternatively, the third engaging portion 43 and the fourth engaging portion 44 may not be formed on each segment 15.

[0079] The third engaging portion 43 is a convex portion that is axially connected to the second engaging portion 42 and protrudes circumferentially from the peripheral edge 15a of another segment 15. The fourth engaging portion 44 is a circumferentially recessed portion that is axially connected to the first engaging portion 41 and formed in the peripheral edge 15a of one segment 15. The fourth engaging portion 44 does not open on the inner surface of the covering member 17, but opens on the outer peripheral surface of the partition wall portion 19e. The third engaging portion 43 is fitted into the fourth engaging portion 44. The third engaging portion 43 and the first engaging portion 41 are stacked axially.

[0080] like Figure 4 and Figure 5 As shown, the covering member 17 is formed by injection molding, and an injection mark portion 36 is provided in the partition wall portion 19e. The injection mark portion 36 is composed of a liquid accumulation recess 36a and a connecting groove 36b, which extends axially from the liquid accumulation recess 36a and communicates with either the first groove 19a or the second groove 19b.

[0081] The injection mark portion 36 is disposed in the partition wall portion 19e at a position closer to either the first communicating opening 18 or the second communicating opening 20. Alternatively, the injection mark portion 36 may be disposed in the partition wall portion 19e at a distance equal to that of both the first communicating opening 18 and the second communicating opening 20.

[0082] The injection indentation 36 is connected to either the first groove 19a or the second groove 19b of the other of the first communicating opening 18 and the second communicating opening 20. Alternatively, the injection indentation 36 may be connected to either the first groove 19a or the second groove 19b of the other of the first communicating opening 18 and the second communicating opening 20.

[0083] In the illustrated example, two injection mark portions 36 are provided on the partition wall portion 19e. One injection mark portion 36 is located closer to the first connecting opening 18 than to the second connecting opening 20 and communicates with the first groove 19a. The other injection mark portion 36 is located closer to the second connecting opening 20 than to the first connecting opening 18 and communicates with the second groove 19b. One injection mark portion 36 is provided on each partition body 15.

[0084] The outer cylinder 12 is fitted onto the covering member 17, thereby elastically connecting the outer cylinder 12 to the inner mounting member 11, and forming a perforated passage between the main body groove 19 and the inner circumferential surface of the outer cylinder 12 to allow communication between the liquid chambers 14a, 14b. The perforated passage allows communication between the liquid chambers 14a, 14b via the first connecting opening 18 and the second connecting opening 20.

[0085] The perforated passage extends circumferentially between the covering member 17 and the outer cylinder 12 for a range of more than one and a half circumferences. In the illustrated example, the perforated passage extends circumferentially between the covering member 17 and the outer cylinder 12 for a range of approximately two circumferences.

[0086] Furthermore, when vibration is input to the vibration isolation device 1, the elastic bodies 31 and 32 undergo elastic deformation and the internal volume of each liquid chamber 14a and 14b changes, thereby causing the liquid in the liquid chambers 14a and 14b to flow through the orifice passage and generate liquid column resonance, thereby attenuating the vibration and absorbing the vibration.

[0087] like Figure 3 As shown, a recess 12b is provided on the outer peripheral surface of the outer cylinder 12, which is recessed radially inward. Alternatively, the recess 12b may not be provided on the outer peripheral surface of the outer cylinder 12. The portion of the inner peripheral surface of the outer cylinder 12 corresponding to the bottom wall of the recess 12b (the portion that becomes the bottom wall) bulges radially inward. The recess 12b is inserted into the inner side of the second chamfered portion 17d in the partition wall portion 19e.

[0088] An injection hole 12a for injecting liquid into liquid chambers 14a and 14b is formed on the bottom wall of the recess 12b. The injection hole 12a opens toward at least one of the first connecting opening 18 and the second connecting opening 20. In the illustrated example, the injection hole 12a opens toward the first connecting opening 18. A seal 16 engages with the injection hole 12a to seal it. In the illustrated example, the seal 16 is a rivet with its head located radially inward from the outer peripheral surface of the outer cylinder 12. The seal 16 is inserted into the first connecting opening 18. Alternatively, the injection hole 12a opening toward the second connecting opening 20 may also be formed on the outer cylinder 12.

[0089] like Figure 6 As shown, the wall surface dividing the orifice passage is formed with: a first shortcut through hole 37, which allows liquid flowing from one liquid chamber 14a toward another liquid chamber 14b in the orifice passage to reach the other liquid chamber 14b in a shortcut manner; and a second shortcut through hole 38, which allows liquid flowing from another liquid chamber 14b toward one liquid chamber 14a in the orifice passage to reach the one liquid chamber 14a in a shortcut manner.

[0090] The flow resistance of the liquid through the first shortcut through-hole 37 and the second shortcut through-hole 38 is less than the flow resistance of the orifice passage. The flow path cross-sectional area of ​​each of the first shortcut through-hole 37 and the second shortcut through-hole 38 is set to, for example, approximately 3 mm². 2 The cross-sectional area of ​​the flow path is smaller than that of the orifice passage. The lengths of the first shortcut through-hole 37 and the second shortcut through-hole 38 are each shorter than the length of the orifice passage.

[0091] The first shortcut through hole 37 and the second shortcut through hole 38 are formed on the outer peripheral surface of the covering member 17 and on the bottom surface of the main body groove 19. The first shortcut through hole 37 and the second shortcut through hole 38 are respectively formed in the two dividing bodies 15.

[0092] The first shortcut through-hole 37 opens at the other end of the first groove 19a in the circumferential direction. The circumferential positions of the first shortcut through-hole 37 and the second connecting opening 20 are equivalent to each other. The second shortcut through-hole 38 opens at the other end of the second groove 19b in the circumferential direction. The circumferential positions of the second shortcut through-hole 38 and the first connecting opening 18 are equivalent to each other. The first shortcut through-hole 37 opens in another liquid chamber 14b at the front end of the flow direction F1 in which liquid flows from one liquid chamber 14a to another liquid chamber 14b within the orifice passage. The second shortcut through-hole 38 opens in one liquid chamber 14a at the front end of the flow direction F2 in which liquid flows from one liquid chamber 14b to one liquid chamber 14a within the orifice passage.

[0093] The first shortcut through hole 37 is positioned at a location more than 180° away from the first connecting opening 18 along the flow direction F1 with the central axis O as the center, and the second shortcut through hole 38 is positioned at a location more than 180° away from the second connecting opening 20 along the flow direction F2 with the central axis O as the center.

[0094] The first shortcut through hole 37 is disposed at the axial center of the first groove 19a, and the second shortcut through hole 38 is disposed at the axial center of the second groove 19b. The opening shape of the first shortcut through hole 37 and the second shortcut through hole 38 in the bottom surface of the main groove 19 is an elongated oval shape with a longer circumferential direction.

[0095] The rear end face 37a of the inner circumferential surface of the first shortcut through-hole 37, located at the rear end in the flow direction F1 of the liquid flowing from one liquid chamber 14a to another liquid chamber 14b within the orifice passage, and facing the front end in the flow direction F1, extends towards the front end in the flow direction F1 as it moves from the radially outer side to the inner side. In the illustrated example, the front end face 37b of the inner circumferential surface of the first shortcut through-hole 37, located at the front end in the flow direction F1 and facing the rear end in the flow direction F1, also extends towards the front end in the flow direction F1 as it moves from the radially outer side to the inner side. The rear end face 37a and the front end face 37b in the first shortcut through-hole 37 are substantially parallel.

[0096] The rear end face 38a of the inner circumferential surface of the second shortcut through-hole 38, located at the rear end of the flow direction F2 in which liquid flows from another liquid chamber 14b toward a liquid chamber 14a within the orifice passage, and facing the front side of the flow direction F2, extends towards the front side of the flow direction F2 as it moves from the radially outer side toward the inner side. In the illustrated example, the front end face 38b of the inner circumferential surface of the second shortcut through-hole 38, located at the front side of the flow direction F2 and facing the rear side of the flow direction F2, also extends towards the front side of the flow direction F2 as it moves from the radially outer side toward the inner side. The rear end face 38a and the front end face 38b of the second shortcut through-hole 38 are substantially parallel.

[0097] like Figure 2 , Figure 10 as well as Figure 11As shown, grooved leakage passages 28 and 29 are formed in the elastic body 32. These grooved leakage passages 28 and 29 elastically deform under the internal pressure of the liquid chambers 14a and 14b, thereby connecting the liquid chambers 14a and 14b to each other and allowing liquid to flow between them. For leakage passages 28 and 29, in the standby state before the internal pressure of the liquid chambers 14a and 14b changes, the covering member 17 causes the partition walls of leakage passages 28 and 29 to elastically deform, thereby blocking the connection between the liquid chambers 14a and 14b via leakage passages 28 and 29.

[0098] Leakage passages 28 and 29 are formed in the intermediate elastomer 32 on the outer surface that abuts against the inner surface of the covering member 17. Leakage passages 28 and 29 open onto the circumferential side of the intermediate elastomer 32. In a front view observed from the radially outer side of the outer surface of the intermediate elastomer 32, leakage passages 28 and 29 extend in a straight line in a direction orthogonal to the axial direction.

[0099] Multiple leakage passages 28 and 29 are formed in the intermediate elastic body 32 at different axial positions. In the illustrated example, one leakage passage 28 and one 29 are formed in the main part 32a and a pair of secondary parts 32b of the intermediate elastic body 32.

[0100] Of the plurality of leakage paths 28 and 29, the first leakage path 28 formed in the main portion 32a is positioned at the axial center of the main portion 32a, while the axial center of the second leakage path 29 formed in the sub-portion 32b is located axially outward from the axial center of the sub-portion 32b. At least two of the plurality of leakage paths 28 and 29 have different flow path lengths. In the illustrated example, the circumferential length of the first leakage path 28 is longer than the circumferential length of the second leakage path 29. The width of the first leakage path 28 is narrower than the width of the second leakage path 29.

[0101] For at least two of the multiple leakage paths 28 and 29, the elastic deformation of the partition walls of the leakage paths 28 and 29 caused by the covering member 17 is different from each other. In this embodiment, the elastic deformation of the partition wall of the first leakage path 28 caused by the covering member 17 is greater than the elastic deformation of the partition wall of the second leakage path 29 caused by the covering member 17. The internal pressure of the open liquid chambers 14a and 14b of the first leakage path 28 is higher than the internal pressure of the open liquid chambers 14a and 14b of the second leakage path 29.

[0102] Alternatively, the elastic deformation of the partition wall of the first leakage passage 28 caused by the covering member 17 can be set below the elastic deformation of the partition wall of the second leakage passage 29 caused by the covering member 17. Additionally, the internal pressure of the liquid chambers 14a and 14b open in the first leakage passage 28 can be set below the internal pressure of the liquid chambers 14a and 14b open in the second leakage passage 29.

[0103] Ribs 17a are formed on the inner surface of the covering member 17, respectively inserted into the first leakage passage 28 and the second leakage passage 29. Multiple ribs 17a are formed on the inner surface of the covering member 17 at radially spaced apart from the central axis O, and are axially spaced. Each rib 17a is inserted into the first leakage passage 28 and the second leakage passage 29. The ribs 17a are arranged along the entire circumferential length of the first leakage passage 28 and the second leakage passage 29. The ribs 17a abut against the inner surfaces of the first leakage passage 28 and the second leakage passage 29 over the entire area.

[0104] Ribs 17a are formed at both circumferential ends in the inner surface of the split body 15. Ribs 17a are broken circumferentially at the circumferential edge 15a of the split body 15 and are formed by combining two split bodies 15 in the circumferential direction.

[0105] The first shortcut through hole 37 and the second shortcut through hole 38 are located axially outside the first leakage passage 28 and axially inside the second leakage passage 29.

[0106] As explained above, in the vibration isolation device 1 according to this embodiment, the injection hole 12a formed on the outer cylinder 12 and sealed by the seal 16 opens toward at least one of the first communication opening 18 and the second communication opening 20. Therefore, even if the seal 16 protrudes radially inward from the inner circumference of the outer cylinder 12 via the injection hole 12a, or if the periphery of the opening of the injection hole 12a in the outer cylinder 12 deforms and protrudes radially inward, the seal 16 and the like will enter at least one of the first communication opening 18 and the second communication opening 20, thus suppressing the situation where the seal 16 and the like abut against the member provided on the inner side of the outer cylinder 12.

[0107] An elastic stop portion 34 protruding toward the liquid chambers 14a and 14b is provided on the outer peripheral surface of the inner mounting member 11. Therefore, when a vibration with a large amplitude is input, the elastic stop portion 34 collides with the outer cylinder 12 through the covering member 17, thereby suppressing further relative displacement between the inner mounting member 11 and the outer cylinder 12.

[0108] The outer peripheral surface of the portion of the stop elastic portion 34 that is opposite to at least one of the first communication opening 18 and the second communication opening 20 is recessed radially inward. Therefore, even if the seal 16 and the like enter the liquid chambers 14a and 14b through at least one of the first communication opening 18 and the second communication opening 20 and the injection hole 12a, the seal 16 and the like can be prevented from abutting against the stop elastic portion 34.

[0109] At least a portion of the periphery of at least one of the first communicating opening 18 and the second communicating opening 20 on the outer peripheral surface of the covering member 17 is formed with a second chamfer 17d, thereby suppressing interference between the sealing member 16 and the outer peripheral surface of the covering member 17, which protrudes radially inward from the inner peripheral surface of the outer cylinder 12.

[0110] The end wall portions 19c, which are located at both ends of the main body groove 19 and extend axially, respectively, divide the inner surfaces of the first communication opening 18 and the second communication opening 20. The circumferential size of the end wall portions 19c is equal along the entire axial length. Therefore, for example, compared to a structure in which the inner end face 19f of the two circumferential end faces 19f and 19g of the end wall portions 19c extends away from the outer end face 19g on the side opposite to the side where the inner end face 19f is located, the first communication opening 18 and the second communication opening 20 are widened circumferentially as they extend from one side of the axial direction to the other, thus ensuring a wider opening area for each of the first communication opening 18 and the second communication opening 20.

[0111] High-viscosity liquid is sealed in liquid chambers 14a and 14b, thus enabling the peak value of the attenuation characteristics based on the resonance of the liquid column in the pore passage to be generated over a wider frequency range, and enabling attenuation performance to be exerted over a wider frequency range.

[0112] Furthermore, the scope of protection of the present invention is not limited to the described embodiments, and various modifications may be made without departing from the scope defined by the claims of the present invention.

[0113] For example, the rigid plate 33 may not be provided in the end elastic body 31, and the fixing part 23 may not be formed in the outer cylinder 12.

[0114] The inner mounting component 11 can also be a structure formed as a single unit.

[0115] Alternatively, the outer diameter of the inner mounting component 11 can be made equal along its entire axial length.

[0116] As for the injection mark portion 36, for example, a structure without the liquid accumulation recess 36a and the connecting groove 36b may be adopted, or a structure provided in the covering member 17 in parts other than the partition wall portion 19e may be adopted, etc.

[0117] Alternatively, the first shortcut through hole 37 and the second shortcut through hole 38 may not be formed in the covering member 17. The location of the first shortcut through hole 37 and the second shortcut through hole 38 in the main body groove 19 is not limited to the described embodiment and can be appropriately modified. Appropriate modifications can also be made such that the inner circumferential surfaces of each of the first shortcut through hole 37 and the second shortcut through hole 38 extend, for example, radially.

[0118] As a pore passage, a structure extending less than one circumference in the circumferential direction can also be adopted.

[0119] The structure shown is that the main groove 19 is formed on the outer peripheral surface of the covering member 17, but the main groove 19 can also be formed on the inner peripheral surface of the outer cylinder 12.

[0120] The liquid sealed in the liquid chambers 14a and 14b is not limited to the embodiments described above; for example, water and ethylene glycol may also be used.

[0121] The reinforcement can be embedded in the intermediate elastic body 32, or the intermediate elastic body 32 can be compressed and deformed without using the covering member 17, or the covering member 17 can be fitted between intermediate elastic bodies 32 that are adjacent to each other in the circumferential direction, so that the intermediate elastic body 32 is exposed between the covering members 17 that are adjacent to each other in the circumferential direction.

[0122] Alternatively, multiple leakage paths 28 and 29 may not be formed in the elastomer 32.

[0123] As an elastic body 32, a structure having a main part 32a and a secondary part 32b is shown. For example, it can also be appropriately modified as follows: a structure having only one of the main part 32a and the secondary part 32b can be adopted.

[0124] Furthermore, without departing from the scope defined by the claims of this invention, the constituent elements in the described embodiments may be appropriately replaced with well-known constituent elements. Additionally, the described embodiments and variations may be appropriately combined.

[0125] According to the vibration isolation device of the first aspect of the present invention, the injection hole formed in the outer cylinder and sealed by the seal opens toward at least one of the first communication opening and the second communication opening. Therefore, even if the seal protrudes radially inward from the inner circumference of the outer cylinder through the injection hole, or even if the periphery of the opening of the injection hole in the outer cylinder is deformed and protrudes radially inward, the seal or the like will enter at least one of the first communication opening and the second communication opening, thus suppressing the situation where the seal or the like abuts against the member provided on the inner side of the outer cylinder.

[0126] According to the first embodiment of the vibration isolation device of the second aspect of the present invention, stop elastic portions protruding toward each of the pair of liquid chambers are respectively provided on the outer peripheral surface of the inner mounting member, and the outer peripheral surface of the portion of these stop elastic portions that is opposite to at least one of the first communication opening and the second communication opening is recessed radially inward.

[0127] According to the vibration isolation device of the second aspect of the present invention, a stop elastic portion protruding toward a pair of liquid chambers is provided on the outer peripheral surface of the inner mounting member. Therefore, when a vibration with a large amplitude is input, the stop elastic portion collides with the outer cylinder through the covering member, thereby suppressing further relative displacement between the inner mounting member and the outer cylinder.

[0128] Furthermore, in the vibration isolation device according to the second aspect of the present invention, the outer peripheral surface of the portion of the stop elastic part that is opposite to at least one of the first communication opening and the second communication opening is recessed inward toward the radial direction. Therefore, even if the seal or the like enters either of the pair of liquid chambers through at least one of the first communication opening and the second communication opening and the injection hole, it is possible to prevent the seal or the like from abutting against the stop elastic part.

[0129] According to the first or second embodiment of the vibration isolation device of the present invention, at least a portion of the periphery of the opening of at least one of the first and second connecting openings on the outer peripheral surface of the covering member is formed with a chamfer.

[0130] According to the vibration isolation device of the third aspect of the present invention, at least a portion of the periphery of at least one of the first and second connecting openings on the outer peripheral surface of the covering member is formed with a chamfered portion, thereby suppressing interference between the sealing member and the outer peripheral surface of the covering member by the sealing member or the like protruding radially inward from the inner peripheral surface of the outer cylinder.

[0131] According to any one of the first to third embodiments of the vibration isolation device of the present invention, a main body groove is formed on the outer peripheral surface of the covering member, and the hole passage is formed between the main body groove and the inner peripheral surface of the outer cylinder. The first connecting opening and the second connecting opening are respectively opened at both ends of the main body groove in the direction of extension of the main body groove. The end wall portions of the wall portions forming the main body groove, which are respectively provided at both ends in the direction of extension of the main body groove and extend in the axial direction, are respectively divided into a portion of the inner surface of the first connecting opening and the second connecting opening. The circumferential size of the end wall portions is equal throughout the entire length of the axial direction.

[0132] According to the vibration isolation device of the fourth aspect of the present invention, the end wall portions of the wall portion forming the main body groove, respectively located at both ends in the direction of extension of the main body groove and extending in the axial direction, are respectively divided to form a portion of the inner surface of the first communication opening and the second communication opening, and the circumferential size of the end wall portions is equal over the entire length of the axial direction. Therefore, for example, compared with a structure in which the inner end face of the two circumferential end faces of the end wall portion, which divides a portion of the inner surface of the first communication opening or the second communication opening, extends away from the outer end face opposite to the side where the inner end face is located as it moves from one side of the axial direction toward the other, the first communication opening and the second communication opening are widened in the circumferential direction as they move from one side of the axial direction to the other, and the opening area of ​​each of the first communication opening and the second communication opening can be ensured to be wider.

[0133] Industrial availability

[0134] According to the vibration isolation device of the present invention, it is possible to suppress the contact between the seal and other components disposed on the inner side of the outer cylinder.

[0135] Explanation of reference numerals in the attached figures

[0136] 1. Vibration isolation device; 11. Inner mounting component; 12. Outer cylinder; 12a. Injection hole; 14a, 14b. Liquid chamber; 16. Seal; 17. Covering component; 17d. Second chamfer (bevel); 18. First connecting opening; 19. Main body groove; 19c. End wall; 20. Second connecting opening; 31. End elastic body (elastic body); 32. Middle elastic body (elastic body); 34. Stop elastic part; O. Central axis.

Claims

1. An isolation device, wherein, The vibration isolation device is provided with: an inner-side mounting member linked to either one of a vibration generating portion and a vibration receiving portion, and an outer cylinder linked to the other of the vibration generating portion and the vibration receiving portion and surrounding the inner-side mounting member; an elastic body elastically linking the inner-side mounting member and the outer cylinder, the elastic body includes a pair of middle elastic bodies each disposed on a side of the inner-side mounting member in a radial direction intersecting a central axis of the outer cylinder, in a plan view observed in an axial direction along the central axis of the outer cylinder, a cover member is disposed between the inner-side mounting member and the outer cylinder, the cover member covering the pair of middle elastic bodies adjacent to each other in a circumferential direction around the central axis in the plan view from an outer side in the radial direction, and dividing a pair of liquid chambers between the pair of middle elastic bodies, a hole passage is formed between the cover member and the outer cylinder to communicate each of the pair of liquid chambers with each other, first and second communication openings are formed in the cover member to respectively communicate each of the pair of liquid chambers with the hole passage, an injection hole formed in the outer cylinder and sealed by a seal member opens toward at least one of the first and second communication openings, the injection hole is used to inject a liquid into each of the pair of liquid chambers, a stopper elastic portion protruding toward each of the pair of liquid chambers is provided in an outer peripheral surface of the inner-side mounting member, and each of the stopper elastic portions directly faces each of the pair of liquid chambers, a main groove is formed in an outer peripheral surface of the cover member, and the hole passage is divided between the main groove and an inner peripheral surface of the outer cylinder, the first and second communication openings respectively open in the main groove at both ends of the main groove in a direction in which the main groove extends, end walls each dividing a part of an inner surface of each of the first and second communication openings are respectively formed in a wall portion dividing the main groove at both ends of the main groove in the direction in which the main groove extends and extending in the axial direction, a size of a circumferential direction of each of the end walls is equal in a range of a total length in the axial direction, the main groove includes first and second grooves extending in the circumferential direction and disposed at different positions in the axial direction from each other, and a third groove connecting the first and second grooves, the third groove extends in a direction inclined with respect to the axial direction, inner and outer end surfaces of the circumferential direction of each of the two end walls extend obliquely with respect to the axial direction.

2. The vibration isolation device according to claim 1, wherein an outer peripheral surface of a part of the stopper elastic portion opposite to at least one of the first and second communication openings is recessed toward an inner side in the radial direction.

3. The vibration isolation device according to claim 1 or 2, wherein a chamfered portion is formed in at least a part of an opening peripheral edge portion of at least one of the first and second communication openings in an outer peripheral surface of the cover member.

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