Vibration isolation device

Abstract

The partition member (16) is provided with a throttling passage (24) connecting the main liquid chamber (14) and the auxiliary liquid chamber (15), a plurality of first communication holes (42a) connecting the main liquid chamber (14) and the storage chamber (42), and a second communication hole (42b) connecting the auxiliary liquid chamber (15) and the storage chamber (42). A first wall surface (16b) of the partition member (16) having the first communication holes (42a) and constituting a part of the inner surface of the main liquid chamber (14) is provided. A cylindrical member (21) protrudes axially toward an elastic body (13), and a plurality of first connecting holes (42a) are opened in both an inner portion (16f) located on the inner side of the cylindrical member (21) and an outer portion (16g) located on the outer side of the cylindrical member (21) in a first wall surface (16b), and a portion of the first connecting hole (42a) and a portion of the second connecting hole (42b) are axially opposite to each other via a movable member (41) in a storage chamber (42).

Description

Technical Field

[0001] The present invention relates to a vibration isolating device which is applied to, for example, automobiles, industrial machinery, etc., and absorbs and attenuates vibrations of a vibration generating part such as an engine.

[0002] This application claims priority based on Japanese Patent Application No. 2019-202583 filed in Japan on November 7, 2019, the contents of which are incorporated herein by reference. Background Art

[0003] As such a vibration isolation device, a structure is conventionally known, which includes: a first mounting member and a second mounting member, the first mounting member being cylindrical and connected to either a vibration generating part or a vibration receiving part, and the second mounting member being connected to the other of the vibration generating part and the vibration receiving part; an elastomer which elastically connects the above-mentioned two mounting members; a partitioning member which divides a liquid chamber in the first mounting member sealed with a liquid into an auxiliary liquid chamber and a main liquid chamber having an elastomer in a part of the partition wall; and a movable member which is accommodated in a storage chamber provided in the partitioning member in a deformable or displaceable manner, and a throttling passage connecting the main liquid chamber and the auxiliary liquid chamber, a plurality of first connecting holes connecting the main liquid chamber and the storage chamber, and a second connecting hole connecting the auxiliary liquid chamber and the storage chamber are formed in the partitioning member.

[0004] In this vibration isolation device, when a relatively high-frequency idle vibration among low-frequency vibrations with a frequency of less than 200 Hz is input in the axial direction, the liquid in the liquid chamber is circulated in the first connecting hole and the second connecting hole while the movable component is deformed or displaced in the storage chamber, thereby attenuating and absorbing the idle vibration. In addition, when a relatively low-frequency swing vibration is input in the axial direction, the liquid in the liquid chamber is circulated in the throttling passage, thereby attenuating and absorbing the swing vibration.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2002-327789 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, the conventional vibration isolation device cannot attenuate or absorb medium-frequency vibrations of 200 Hz to 1000 Hz.

[0010] The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to provide a vibration isolation device capable of attenuating and absorbing medium-frequency vibrations.

[0011] Solutions for solving problems

[0012] A vibration isolation device according to a technical solution of the present invention includes: a first mounting member and a second mounting member, the first mounting member being cylindrical and connected to one of a vibration generating part and a vibration receiving part, and the second mounting member being connected to the other of the vibration generating part and the vibration receiving part; an elastic body elastically connecting the two mounting members; a partition member that divides a liquid chamber sealed in the first mounting member into an auxiliary liquid chamber and a main liquid chamber having the elastic body in a part of a partition wall in an axial direction along the central axis of the first mounting member; and a movable member that is accommodated in a storage chamber provided in the partition member in a deformable or displaceable manner. A throttling passage connecting the main liquid chamber and the auxiliary liquid chamber, a plurality of first communication holes connecting the main liquid chamber and the storage chamber, and a second communication hole connecting the auxiliary liquid chamber and the storage chamber are formed in the partition member. A cylindrical member is provided on the first wall of the partition member, which is provided with the first communicating hole and constitutes a part of the inner surface of the main liquid chamber, and which protrudes toward the elastic body along the axial direction. The plurality of first communicating holes are opened in both the inner part located inside the cylindrical member and the outer part located outside the cylindrical member in the first wall. A part of the first communicating hole and a part of the second communicating hole are opposite to each other in the axial direction via the movable member.

[0013] Effects of the Invention

[0014] According to the present invention, medium-frequency vibration can be attenuated and absorbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a longitudinal sectional view of the vibration isolation device according to one embodiment of the present invention.

[0016] Figure 2 yes Figure 1 A cross-sectional view of the vibration isolation device taken along line A-A is shown. DETAILED DESCRIPTION

[0017] The following is based on Figure 1 and Figure 2 Embodiments of the vibration isolation device of the present invention will be described.

[0018] like Figure 1As shown, the vibration isolation device 1 is a liquid-sealed vibration isolation device, which includes: a first mounting member 11 and a second mounting member 12, the first mounting member 11 is cylindrical and connected to any one of the vibration generating part and the vibration receiving part, and the second mounting member 12 is connected to the other of the vibration generating part and the vibration receiving part; an elastomer 13, which elastically connects the first mounting member 11 and the second mounting member 12 to each other; a partition member 16, which divides the liquid chamber 19 in the first mounting member 11 sealed with liquid into an auxiliary liquid chamber 15 and a main liquid chamber 14 having the elastomer 13 in a part of the partition wall; and a movable member 41, which is housed in a housing chamber 42 provided in the partition member 16 in a deformable or displaceable manner.

[0019] Hereinafter, the direction along the central axis O of the first mounting member 11 is referred to as the axial direction. In addition, the side where the second mounting member 12 is located in the axial direction is referred to as the upper side, and the side where the partition member 16 is located is referred to as the lower side. In addition, when the vibration isolation device 1 is viewed from above from the axial direction, the direction intersecting the central axis O is referred to as the radial direction, and the direction surrounding the central axis O is referred to as the circumferential direction.

[0020] Furthermore, the first mounting member 11 , the second mounting member 12 , and the elastic body 13 each have a circular shape or an annular shape in a plan view, and are arranged coaxially with the central axis O. As shown in FIG.

[0021] When the vibration isolating device 1 is installed in a car, for example, the second mounting member 12 is connected to the engine or the like as a vibration generating part, and the first mounting member 11 is connected to the vehicle body as a vibration receiving part. Thus, the transmission of the vibration of the engine or the like to the vehicle body is suppressed. Alternatively, the first mounting member 11 may be connected to the vibration generating part, and the second mounting member 12 may be connected to the vibration receiving part.

[0022] The first mounting member 11 includes an inner tube portion 11 a , an outer tube portion 11 b , and a lower support portion 11 c .

[0023] The inner tube portion 11a is fitted into the outer tube portion 11b. The lower support portion 11c is formed in an annular shape. The lower end opening edge of the outer tube portion 11b is placed on the upper surface of the outer peripheral portion of the lower support portion 11c. The first mounting member 11 is formed in a cylindrical shape as a whole. The first mounting member 11 is connected to a vehicle body or the like as a vibration receiving portion by means of a bracket not shown in the figure.

[0024] The second mounting member 12 is located radially inside and above the first mounting member 11. The outer diameter of the second mounting member 12 is smaller than the inner diameter of the first mounting member 11. The second mounting member 12 is fitted inside by a mounting metal fitting (not shown) and is connected to an engine or the like as a vibration generating portion via the mounting metal fitting.

[0025] The relative positions of the first mounting member 11 and the second mounting member 12 are not limited to the illustrated example and may be appropriately changed. In addition, the outer diameter of the second mounting member 12 may be equal to or larger than the inner diameter of the first mounting member 11 .

[0026] The elastic body 13 is formed in a cylindrical shape extending in the axial direction, and the diameter of the elastic body 13 increases from the upper side toward the lower side.

[0027] The first mounting member 11 and the second mounting member 12 are connected to the two axial ends of the elastic body 13, respectively. The second mounting member 12 is connected to the upper end of the elastic body 13, and the first mounting member 11 is connected to the lower end of the elastic body 13. The elastic body 13 closes the upper end opening of the first mounting member 11. The lower end of the elastic body 13 is connected to the inner circumferential surface of the inner tube portion 11a of the first mounting member 11. The upper end of the elastic body 13 is connected to the lower surface of the second mounting member 12. The elastic body 13 is formed of a rubber material or the like, and is vulcanized and bonded to the first mounting member 11 and the second mounting member 12. The thickness of the elastic body 13 becomes thinner from the top to the bottom. In addition, the elastic body 13 can also be formed of a synthetic resin material or the like, for example.

[0028] A stopper rubber 13a covering the outer peripheral surface and the upper surface of the second mounting member 12 is integrally formed at the upper end of the elastic body 13. An outer housing 12a surrounding the second mounting member 12 is embedded in the elastic body 13 and the stopper rubber 13a.

[0029] The diaphragm 20 is formed of an elastic material such as rubber or soft resin and is formed into a bottomed cylindrical shape. The upper end of the diaphragm 20 is sandwiched between the inner circumference of the lower support portion 11c of the first mounting member 11 and the outer circumference of the partition member 16, thereby ensuring the liquid tightness of the inner side of the diaphragm 20 and closing the lower end opening of the first mounting member 11.

[0030] In the example shown in the figure, the bottom of the diaphragm 20 is deep on the outer peripheral side and shallow in the center. However, as the shape of the diaphragm 20, various shapes known in the art can be adopted besides this shape.

[0031] The lower end opening of the first mounting member 11 is closed by the diaphragm 20, and the upper end opening of the first mounting member 11 is closed by the elastic body 13 as described above, so that the first mounting member 11 forms a liquid chamber 19 which is sealed liquid-tightly. A liquid is sealed (filled) in the liquid chamber 19. Examples of the liquid include ethylene glycol, water, and silicone oil.

[0032] The liquid chamber 19 is divided into a main liquid chamber 14 and a sub-liquid chamber 15 in the axial direction by a partition member 16. The main liquid chamber 14 has an inner peripheral surface 13c of the elastic body 13 in a part of the wall surface, and is a space surrounded by the elastic body 13 and the partition member 16, and the inner volume changes according to the deformation of the elastic body 13. The sub-liquid chamber 15 is a space surrounded by the diaphragm 20 and the partition member 16, and the inner volume changes according to the deformation of the diaphragm 20. The vibration isolation device 1 having such a structure is a compression type device installed and used in a manner that the main liquid chamber 14 is located on the upper side in the vertical direction and the sub-liquid chamber 15 is located on the lower side in the vertical direction.

[0033] The partition member 16 is formed with a plurality of first communicating holes 42a that communicate the main liquid chamber 14 and the storage chamber 42, and a second communicating hole 42b that communicates the auxiliary liquid chamber 15 and the storage chamber 42. A plurality of second communicating holes 42b are formed in the partition member 16. The first communicating holes 42a and the second communicating holes 42b that are opposite to each other in the axial direction have the same flow path length. In addition, one second communicating hole 42b may be formed in the partition member 16.

[0034] Here, in the partition member 16, the upper wall surface constituting a part of the inner surface of the main liquid chamber 14 and the lower wall surface constituting a part of the inner surface of the auxiliary liquid chamber 15 are respectively in a circular shape arranged coaxially with the central axis O when viewed from the axial direction. The diameters of the upper wall surface and the lower wall surface of the partition member 16 are equal to each other. The upper wall surface of the partition member 16 is opposite to the inner peripheral surface 13c of the elastic body 13 in the axial direction, and the lower wall surface of the partition member 16 is opposite to the inner surface of the diaphragm 20 in the axial direction.

[0035] In the example shown in the figure, a concave portion is formed in the entire area of ​​the upper wall surface of the partition member 16 except the peripheral portion 16a. A plurality of first connecting holes 42a are opened in the entire area of ​​the bottom surface (hereinafter referred to as the first wall surface) 16b of the concave portion. A concave portion is formed in the entire area of ​​the lower wall surface of the partition member 16 except the peripheral portion 16c. A plurality of second connecting holes 42b are opened in the entire area of ​​the bottom surface (hereinafter referred to as the second wall surface) 16d of the concave portion. The concave portions of the upper wall surface and the lower wall surface are each in a circular shape coaxially arranged with the central axis O when viewed from the axial direction, and the inner diameter and depth of each concave portion are equal to each other.

[0036] The storage chamber 42 is formed in a portion of the partition member 16 located between the first wall surface 16b and the second wall surface 16d in the axial direction. The storage chamber 42 has a circular shape coaxially arranged with the central axis O when viewed from the axial direction. The diameter of the storage chamber 42 is larger than the diameter of each of the first wall surface 16b and the second wall surface 16d.

[0037] The movable member 41 is formed in a plate shape with its front and back sides facing the axial direction. When viewed from the axial direction, the movable member 41 has a circular shape arranged coaxially with the central axis O. The movable member 41 is formed of an elastic material such as rubber or soft resin.

[0038] A throttling passage 24 is formed in the partition member 16 to connect the main liquid chamber 14 and the auxiliary liquid chamber 15. The throttling passage 24 is formed in the axial portion between the outer peripheral edge portion 16a of the upper wall surface and the outer peripheral edge portion 16c of the lower wall surface in the partition member 16. The upper end of the throttling passage 24 is located above the first wall surface 16b, and the lower end of the throttling passage 24 is located below the second wall surface 16d. The flow path cross-sectional shape of the throttling passage 24 is a rectangular shape that is longer in the axial direction. The resonance frequency of the throttling passage 24 is lower than the resonance frequency when the liquid passes through the first connecting hole 42a and the second connecting hole 42b and travels between the main liquid chamber 14 and the auxiliary liquid chamber 15.

[0039] like Figure 2 As shown in the figure, the opening 25 of the main liquid chamber 14 side of the throttling passage 24 is formed at the outer peripheral edge 16a of the upper wall surface of the partition member 16. The opening 25 is formed by arranging a plurality of through holes 25a at intervals in the circumferential direction, and a plurality of hole rows 25b are arranged in a manner that each position in the radial direction and the circumferential direction is different. Two hole rows 25b are arranged at the outer peripheral edge 16a of the upper wall surface of the partition member 16. The circumferential offset of each hole row 25b and the radial offset of each hole row 25b are respectively equal to the inner diameter of the through hole 25a.

[0040] The opening portion of the throttle passage 24 on the auxiliary liquid chamber 15 side is formed at the outer peripheral edge portion 16c of the lower wall surface of the partition member 16, and is an opening having an opening area larger than the opening area of ​​the opening portion 25 on the main liquid chamber 14 side, that is, the total opening area of ​​the plurality of through holes 25a. The opening portion 25 on the main liquid chamber 14 side and the opening portion on the auxiliary liquid chamber 15 side of the throttle passage 24 are located radially outward of the first communicating hole 42a and the second communicating hole 42b.

[0041] A flange portion 16e is formed at the upper end of the partition member 16. The flange portion 16e protrudes toward the outside in the radial direction and extends continuously over the entire circumference. The upper surface of the flange portion 16e abuts against the lower end opening edges of the inner tube portion 11a and the outer tube portion 11b of the first mounting member 11 via an annular upper side sealing material 27. The lower surface of the flange portion 16e abuts against the upper surface of the inner circumference of the lower support portion 11c of the first mounting member 11 via the upper end opening edge of the diaphragm 20 and an annular lower side sealing material 28 surrounding the upper end opening edge of the diaphragm 20 from the outside in the radial direction.

[0042] The partition member 16 includes an upper cylinder 31 and a lower cylinder 32 disposed so as to abut against each other in the axial direction, an upper wall 33 closing the lower end opening of the upper cylinder 31, and a lower wall 34 closing the upper end opening of the lower cylinder 32. Alternatively, the partition member 16 may be formed integrally.

[0043] The upper end opening edge of the upper cylinder 31 is the outer peripheral edge portion 16a of the upper wall surface of the aforementioned partition member 16. A flange portion 16e is formed at the upper end portion of the upper cylinder 31. A circumferential groove is formed at a portion of the lower end opening edge of the upper cylinder 31 that is located radially outward relative to the inner circumference, and the circumferential groove is recessed upward and opens radially outward.

[0044] The upper wall 33 is fixed to the inner peripheral portion of the lower end opening edge of the upper cylinder 31. The upper wall 33 is formed with a first communication hole 42a.

[0045] A circumferential groove that is concave downward is formed in the radial middle portion of the upper end opening edge of the lower cylinder 32, which is axially opposite to the circumferential groove of the upper cylinder 31. The throttling passage 24 is divided by the circumferential groove (circumferential groove of the lower cylinder 32) and the circumferential groove of the upper cylinder 31. The outer peripheral edge portion of the upper end opening edge of the lower cylinder 32, which is located radially outside the circumferential groove, abuts against the lower surface of the flange portion 16e of the upper cylinder 31. The lower cylinder 32 is embedded in the upper end portion of the diaphragm 20, and the upper end portion of the diaphragm 20 is embedded in the lower support portion 11c of the first mounting member 11. As a result, the upper end portion of the diaphragm 20 is clamped in the radial direction by the outer peripheral surface of the lower cylinder 32 and the inner peripheral surface of the lower support portion 11c.

[0046] The lower wall 34 is fixed to the inner peripheral portion of the upper end opening edge of the lower cylinder 32. The lower wall 34 is formed with a second communication hole 42b.

[0047] At least one of the inner circumference of the lower end opening edge of the upper cylinder 31 and the inner circumference of the upper end opening edge of the lower cylinder 32 is formed with abutment protrusions 34a, 34b that protrude toward the other and abut against the other. In the illustrated example, abutment protrusions 34a, 34b are formed on both the inner circumference of the lower end opening edge of the upper cylinder 31 and the inner circumference of the upper end opening edge of the lower cylinder 32. The abutment protrusions 34a, 34b are formed in an annular shape coaxially arranged with the central axis O, and the upper wall 33 and the lower wall 34 are arranged on the radial inner side of the abutment protrusions 34a, 34b in a state of being spaced apart from each other in the axial direction. The storage chamber 42 is divided and formed by the lower surface of the upper wall 33, the upper surface of the lower wall 34, and the inner circumferential surface of the abutment protrusions 34a, 34b.

[0048] Furthermore, in the present embodiment, a cylindrical member 21 is disposed on the first wall surface 16 b of the partition member 16 , which has the first communication hole 42 a and constitutes a part of the inner surface of the main liquid chamber 14 , and projects in the axial direction toward the elastic body 13 .

[0049] The cylindrical member 21 is formed in a cylindrical shape and is arranged coaxially with the central axis O. The cylindrical member 21 extends straight in the axial direction. The axial length of the cylindrical member 21 is more than 20% of the maximum axial height T of the main liquid chamber 14. In the illustrated example, the maximum axial height T of the main liquid chamber 14 is the axial distance between the upper end of the inner circumferential surface 13c of the elastomer 13 and the first wall surface 16b extending radially inward from the bottom to the top. The axial length of the cylindrical member 21 is set so that the upper end of the cylindrical member 21 does not abut against the inner circumferential surface 13c of the elastomer 13 when an axial static load is applied to the vibration isolation device 1 and when an axial vibration is input.

[0050] In addition, as described above, the inner circumferential surface 13c of the elastic body 13 is a portion extending radially inward from the bottom to the top. In addition, as in the example shown in the figure, when the upper end of the inner surface of the elastic body 13 that divides and forms the main liquid chamber 14 is provided with a concave portion that is concave upward, the upper end of the inner circumferential surface 13c of the elastic body 13 refers to the opening peripheral edge of the concave portion of the inner surface of the elastic body 13.

[0051] The upper part of the cylindrical member 21 protrudes upward from the upper end opening of the concave portion formed on the upper wall surface of the partition member 16. The outer peripheral surface of the upper part of the cylindrical member 21 is opposite to the lower end of the inner peripheral surface of the inner cylindrical portion 11a of the first mounting member 11 and the lower end of the inner peripheral surface 13c of the elastic body 13 in a state of being provided with a gap in the radial direction. The protruding length of the upper part of the cylindrical member 21 from the upper end opening of the concave portion is shorter than the depth of the concave portion. In addition, the protruding length is shorter than the axial distance between the portion of the inner peripheral surface 13c of the elastic body 13 that is opposite to the upper end opening edge of the cylindrical member 21 in the axial direction and the upper end opening edge of the cylindrical member 21. The upper end opening edge of the cylindrical member 21 is opposite to the portion of the inner peripheral surface 13c of the elastic body 13 that extends inward in the radial direction from the bottom to the top, and that is offset downward from the central portion in the direction in which the inner peripheral surface 13c extends when viewed in a longitudinal section along the axial direction.

[0052] The radius of the inner circumference of the cylindrical member 21 is larger than the radial interval between the outer circumference of the cylindrical member 21 and the inner circumference of the recessed portion formed on the upper wall of the partition member 16. The inner diameter of the cylindrical member 21 is more than half of the maximum inner diameter R of the main liquid chamber 14. In the example shown in the figure, the maximum inner diameter R of the main liquid chamber 14 is the inner diameter of the lower end of the inner cylinder 11a of the first mounting member 11. The plane area of ​​the portion 16f of the first wall surface 16b located on the inner side of the cylindrical member 21 (hereinafter referred to as the inner portion) is larger than the plane area of ​​the portion 16g located on the outer side of the cylindrical member 21 (hereinafter referred to as the outer portion).

[0053] The plurality of first communication holes 42a are open to both the inner portion 16f and the outer portion 16g of the first wall surface 16b. All of the plurality of first communication holes 42a face the upper surface of the movable member 41. All of the plurality of second communication holes 42b face the lower surface of the movable member 41.

[0054] The cylindrical member 21 is connected to a portion of the first wall surface 16 b located between adjacent first communication holes 42 a , and is disposed so as not to overlap with the first communication holes 42 a .

[0055] Moreover, in the present embodiment, a part of the first communicating hole 42a and a part of the second communicating hole 42b are axially opposed to each other via the movable member 41. All of the plurality of first communicating holes 42a are axially opposed to the second communicating holes 42b via the movable member 41, and all of the plurality of second communicating holes 42b are axially opposed to the first communicating hole 42a via the movable member 41. When viewed from the axial direction, the shapes of the first communicating hole 42a and the second communicating hole 42b are different from each other.

[0056] In addition, Figure 2 In FIG. 1 , the first communication hole 42 a is indicated by dotted hatching.

[0057] The first communicating hole 42a is a curved long hole extending along the cylindrical member 21 when viewed from the axial direction. The first communicating hole 42a is in a curved rectangular shape extending in the circumferential direction. The circumferential end edge of the first communicating hole 42a extends in the radial direction and is located on a straight line passing through the central axis O when viewed from the axial direction.

[0058] A plurality of first communicating holes 42a are provided on the first wall surface 16b at equal intervals in the circumferential direction. The intervals between the first communicating holes 42a adjacent to each other in the circumferential direction are narrower than the circumferential size of the first communicating holes 42a. The flow path cross-sectional areas of the first communicating holes 42a adjacent to each other in the circumferential direction are the same.

[0059] A plurality of first communicating holes 42a are provided at intervals in the radial direction. The circumferential end edges of the first communicating holes 42a adjacent to each other in the radial direction are located on the same straight line passing through the central axis O when viewed from the axial direction. With respect to the plurality of first communicating holes 42a opening in the first wall surface 16b, the first communicating holes 42a located radially outward have longer circumferential lengths.

[0060] Two rows of a plurality of first communication holes 42a arranged at equal intervals in the circumferential direction are provided in the inner portion 16f at intervals in the radial direction. In the inner portion 16f, the radial interval between the first communication holes 42a adjacent to each other in the radial direction is equal to the radial width of the first communication hole 42a. One row of a plurality of first communication holes 42a arranged at equal intervals in the circumferential direction is provided in the outer portion 16g.

[0061] Alternatively, only one row of a plurality of first communication holes 42a spaced apart in the circumferential direction may be provided in the inner portion 16f. A plurality of first communication holes 42a spaced apart in the radial direction may be provided in the outer portion 16g.

[0062] The radial widths of the plurality of first communication holes 42a provided in the inner portion 16f are the same as each other. The radial widths of the first communication holes 42a provided in the inner portion 16f are wider than the radial widths of the first communication holes 42a provided in the outer portion 16g.

[0063] In addition, the radial width of the first communication hole 42a provided in the inner portion 16f may be set to be less than the radial width of the first communication hole 42a provided in the outer portion 16g.

[0064] The first communication hole 42a provided in the inner portion 16f is a curved long hole extending along the inner peripheral surface of the cylindrical member 21 when viewed from the axial direction. The first communication hole 42a provided in the outer portion 16g is a curved long hole extending along the outer peripheral surface of the cylindrical member 21 when viewed from the axial direction.

[0065] Furthermore, the shapes of the inner peripheral surface and the outer peripheral surface of the cylindrical member 21 as viewed from the axial direction may be different from each other.

[0066] When viewed from the axial direction, the radial inner edge of the first communicating hole 42a provided in the outer portion 16g coincides with the outer peripheral surface of the cylindrical member 21. When viewed from the axial direction, the radial outer edge of the first communicating hole 42a located most radially outward among the plurality of first communicating holes 42a provided in the inner portion 16f coincides with the inner peripheral surface of the cylindrical member 21.

[0067] In addition, the first communicating hole 42a provided in the outer portion 16g may be separated from the outer peripheral surface of the cylindrical member 21 in the radial direction outward. The first communicating hole 42a located most radially outward among the plurality of first communicating holes 42a provided in the inner portion 16f may be separated from the inner peripheral surface of the cylindrical member 21 in the radial direction inward.

[0068] The second communication hole 42b is a long hole extending in the radial direction. The second communication hole 42b is axially opposed to the plurality of first communication holes 42a adjacent to each other in the radial direction via the movable member 41. The second communication hole 42b is axially opposed to the plurality of first communication holes 42a opened in the inner portion 16f and the outer portion 16g, respectively, via the movable member 41.

[0069] That is, one second communication hole 42 b and a plurality of first communication holes 42 a (three in the illustrated example) that are adjacent to each other in the radial direction face each other in the axial direction via the movable member 41 .

[0070] The radial outer edge of the second communicating hole 42b is located at the same radial position as the radial outer edge of the first communicating hole 42a provided in the outer portion 16g. The radial inner edge of the second communicating hole 42b is located radially inward of the radial inner edge of the first communicating hole 42a located most radially inward among the plurality of first communicating holes 42a provided in the inner portion 16f.

[0071] In addition, the second connecting hole 42b may extend intermittently in the radial direction. For example, the radial inner edge of the second connecting hole 42b may be located at the same radial position as the radial inner edge of the first connecting hole 42a located most radially inward among the plurality of first connecting holes 42a provided in the inner portion 16f.

[0072] A plurality of second communication holes 42b are provided in the second wall surface 16d at equal intervals in the circumferential direction. One first communication hole 42a and a plurality of second communication holes 42b (four in the illustrated example) are axially opposed to each other via the movable member 41. When viewed from the axial direction, the outer circumferential edge of the second communication hole 42b located most circumferentially outward among the plurality of second communication holes 42b that are axially opposed to the first communication hole 42a is located on the same straight line passing through the central axis O as the circumferential edge of the first communication hole 42a.

[0073] The flow path cross-sectional areas of the plurality of second communicating holes 42b are the same. The circumferential width of the second communicating holes 42b is narrower than the radial width of the first communicating holes 42a. The circumferential width of the second communicating holes 42b may be set to be greater than the radial width of the first communicating holes 42a.

[0074] The sum of the overlapping areas of the first communicating hole 42a and the second communicating hole 42b opened in the outer portion 16g relative to each other in the axial direction across the movable member 41 is different from the sum of the overlapping areas of the first communicating hole 42a and the second communicating hole 42b opened in the inner portion 16f relative to each other in the axial direction across the movable member 41. In the example shown in the figure, the former is less than the latter.

[0075] Here, the thickness of each of the upper wall 33 and the lower wall 34 is the same over the entire region, and the flow path length of the first communicating hole 42a opened at the outer portion 16g is the same as the flow path length of the first communicating hole 42a opened at the inner portion 16f. Alternatively, the flow path length of the first communicating hole 42a opened at the outer portion 16g may be different from the flow path length of the first communicating hole 42a opened at the inner portion 16f.

[0076] In the vibration isolation device 1 having such a structure, when an idling vibration with a relatively high frequency among low-frequency vibrations is input in the axial direction, the liquid in the liquid chamber 19 flows through the first communicating hole 42a and the second communicating hole 42b while the movable member 41 is deformed or displaced in the storage chamber 42, thereby attenuating and absorbing the vibration. In addition, when a rocking vibration with a relatively low frequency among low-frequency vibrations is input in the axial direction, the liquid in the liquid chamber 19 flows through the throttle passage 24, thereby attenuating and absorbing the vibration.

[0077] As described above, according to the vibration isolation device 1 of the present embodiment, the cylindrical member 21 protruding toward the elastic body 13 is disposed on the first wall surface 16b of the partition member 16. Therefore, when the elastic body 13 is deformed in the secondary vibration mode in the longitudinal section along the axial direction with the input of the intermediate frequency vibration in the axial direction, the node portion that has been generated in the central part of the elastic body 13 (the central part of the elastic body 13 in the axial direction) is offset to the second mounting member 12 side, for example, because the liquid between the inner peripheral surface of the main liquid chamber 14 and the outer peripheral surface of the upper part of the cylindrical member 21 is difficult to flow. Therefore, in the elastic body 13, the portion located on the first mounting member 11 side than the node portion is easier to deform than the portion located on the second mounting member 12 side than the node portion. Therefore, when the intermediate frequency vibration in the axial direction is input, in the elastic body 13, the portion located on the first mounting member 11 side than the node portion is actively deformed, and the stiffness of the elastic body 13 can be reduced in appearance, and the vibration can be attenuated and absorbed.

[0078] In addition, since the plurality of first connecting holes 42a open in both the inner portion 16f and the outer portion 16g of the first wall surface 16b, many first connecting holes 42a can be arranged on the first wall surface 16b, for example, idling vibrations with relatively high frequencies among low-frequency vibrations can be reliably attenuated and absorbed.

[0079] A portion of the first communication hole 42a and a portion of the second communication hole 42b are opposed to each other in the axial direction via the movable member 41. Therefore, even if the flow path cross-sectional area of ​​each of the first communication hole 42a and the second communication hole 42b is not adjusted, the frequency of resonance when the liquid moves between the main liquid chamber 14 and the auxiliary liquid chamber 15 via the first communication hole 42a and the second communication hole 42b with the input of vibration can be tuned by adjusting the overlapping area of ​​the first communication hole 42a and the second communication hole 42b opposed to each other in the axial direction via the movable member 41. As a result, it is not necessary to reduce the flow path cross-sectional area of ​​each of the first communication hole 42a and the second communication hole 42b during tuning. Therefore, when the partition member 16 is formed by casting or injection molding, for example, it is not necessary to make the pins for forming the first communication hole 42a and the second communication hole 42b thin, and it is possible to prevent the situation that the durability of the pins is reduced, etc., which makes manufacturing difficult.

[0080] Since the first communication hole 42 a and the second communication hole 42 b have different shapes when viewed in the axial direction, the overlapping area of ​​the first communication hole 42 a and the second communication hole 42 b facing each other in the axial direction with the movable member 41 interposed therebetween can be easily adjusted.

[0081] Since the first communicating hole 42a is a curved long hole extending along the tubular member 21 when viewed from the axial direction, when the partition member 16 is formed by casting or injection molding, for example, the fluidity of the molten material in the cavity can be ensured and the complexity of the mold structure can be prevented.

[0082] Since the second connecting hole 42b is set as a long hole extending in the radial direction and is axially opposite to the multiple first connecting holes 42a provided on the first wall surface 16b via the movable component 41, it is easy to ensure the overlapping area of ​​the first connecting hole 42a and the second connecting hole 42b relative to each other in the axial direction via the movable component 41.

[0083] Furthermore, since the axial length of the cylindrical member 21 is equal to or greater than 20% of the maximum axial height T of the main liquid chamber 14 , the intermediate frequency vibration in the axial direction can be reliably attenuated and absorbed.

[0084] Furthermore, since the inner diameter of the cylindrical member 21 is equal to or more than half of the maximum inner diameter R of the main liquid chamber 14 , the intermediate frequency vibration in the axial direction can be reliably attenuated and absorbed.

[0085] The sum of the overlapping areas of the first communicating hole 42a and the second communicating hole 42b opened in the outer portion 16g in the axial direction across the movable member 41 is different from the sum of the overlapping areas of the first communicating hole 42a and the second communicating hole 42b opened in the inner portion 16f in the axial direction across the movable member 41. Thus, the flow state of the liquid between the inner peripheral surface of the main liquid chamber 14 and the outer peripheral surface of the tubular member 21, such as the flow velocity, can be adjusted, and the position of the node portion can be easily adjusted.

[0086] In addition, the protective scope of the present invention is not limited to the above-described embodiment, and various modifications can be added within the scope not departing from the gist of the present invention.

[0087] For example, the first communication hole 42 a and the second communication hole 42 b may have the same shape and size as each other when viewed from the axial direction.

[0088] As the first communication hole 42 a , for example, a circular hole when viewed from the axial direction or a long hole extending in a direction intersecting the cylindrical member 21 when viewed from the axial direction may be adopted.

[0089] As the second communication hole 42 b , for example, a long hole extending in a direction intersecting the radial direction when viewed from the axial direction, or a hole having a circular shape when viewed from the axial direction may be adopted.

[0090] One first communication hole 42 a and one second communication hole 42 b may be opposed to each other in the axial direction via the movable member 41 at a plurality of locations.

[0091] Some of the plurality of first communication holes 42 a may be axially opposed to the second communication holes 42 b via the movable member 41 , and some of the plurality of second communication holes 42 b may be axially opposed to the first communication holes 42 a via the movable member 41 .

[0092] Alternatively, the sum of the axially relative overlapping areas of the first communicating hole 42a and the second communicating hole 42b opened at the outer portion 16g with the movable member 41 therebetween may be set to be greater than the sum of the axially relative overlapping areas of the first communicating hole 42a and the second communicating hole 42b opened at the inner portion 16f with the movable member 41 therebetween.

[0093] In addition, the size of the overlapping area of ​​the first communication hole 42a and the second communication hole 42b facing each other in the axial direction with the movable member 41 interposed therebetween may be made different depending on the area along the circumferential direction. In this case, when a vibration is input in the direction of the area where the overlapping area is larger relative to the central axis O in the lateral direction intersecting the axial direction and when a vibration is input in the direction of the area where the overlapping area is smaller relative to the central axis O in the lateral direction intersecting the axial direction, for example, the first communication hole 42a through which the liquid flows more among the plurality of first communication holes 42a is changed, so that the degree of flow of the liquid in the entire liquid chamber 19 can be made different. Thus, the elasticity exhibited by the vibration isolating device 1 can be made different when a vibration is input in the direction of the area where the overlapping area is larger relative to the central axis O in the lateral direction and when a vibration is input in the direction of the area where the overlapping area is smaller relative to the central axis O in the lateral direction.

[0094] A clamping wall having a through hole extending axially therethrough may be provided between the first wall surface 16b and the movable member 41, so that a portion of the through hole of the clamping wall is axially opposite to a portion of the first connecting hole 42a. Furthermore, a clamping wall having a through hole extending axially therethrough may be provided between the second wall surface 16d and the movable member 41, so that a portion of the through hole of the clamping wall is axially opposite to a portion of the second connecting hole 42b.

[0095] In the above case, it is possible to reliably eliminate the need to reduce the flow path cross-sectional area of ​​each of the through hole of the interposition wall, the first communication hole 42 a , and the second communication hole 42 b .

[0096] Furthermore, although the structure in which the cylindrical member 21 is connected to the first wall surface 16b so as not to overlap with the first communicating hole 42a is shown, the cylindrical member 21 may be connected to the first wall surface 16b so as to overlap with the first communicating hole 42a.

[0097] Furthermore, although the elastic body 13 is shown as a structure formed in a cylindrical shape extending in the axial direction, a structure formed in a ring-shaped plate having upper and lower surfaces may be adopted.

[0098] Furthermore, although a recessed portion is formed on the upper wall surface of the partition member 16 , the recessed portion may not be formed.

[0099] Furthermore, in the embodiment, a compression-type vibration isolation device 1 is described in which a positive pressure is applied to the main liquid chamber 14 due to an applied supporting load, but the device can also be applied to a suspension-type vibration isolation device as follows: the device is installed in such a manner that the main liquid chamber 14 is located at a lower side in the vertical direction and the auxiliary liquid chamber 15 is located at an upper side in the vertical direction, and a negative pressure is applied to the main liquid chamber 14 due to an applied supporting load.

[0100] Furthermore, the vibration isolation device 1 of the present invention is not limited to being applied to an engine mount of a vehicle, but can also be applied to equipment other than an engine mount, for example, a generator mount mounted on a construction machine, or a machine mount installed in a factory or the like.

[0101] Furthermore, the components of the above-described embodiment may be appropriately replaced with well-known components without departing from the gist of the present invention, and the above-described embodiment and modified examples may be appropriately combined.

[0102] According to the technical solution of the present invention, a cylindrical member (21) protruding toward the elastomer (13) is provided on the first wall surface (16b) of the partition member (16). Therefore, with the input of axial intermediate frequency vibration, when the elastomer is deformed in a secondary vibration mode when viewed in longitudinal section along the axial direction, the node portion previously generated in the central portion of the elastomer is offset toward the second mounting member (12) side, for example, due to the difficulty of liquid flowing between the inner circumference of the main liquid chamber and the outer circumference of the cylindrical member. As a result, in the elastomer, the portion located closer to the first mounting member (11) than the node portion is easier to deform than the portion located closer to the second mounting member than the node portion. Therefore, when axial intermediate frequency vibration is input, in the elastomer, the portion located closer to the first mounting member than the node portion is actively deformed, which can apparently reduce the stiffness of the elastomer and can attenuate and absorb the vibration.

[0103] In addition, since the plurality of first connecting holes (42a) open in both the inner portion (16f) located on the inner side of the cylindrical member and the outer portion (16g) located on the outer side of the cylindrical member in the first wall surface, many first connecting holes can be arranged on the first wall surface, for example, idling vibrations with relatively high frequencies among low-frequency vibrations can be reliably attenuated and absorbed.

[0104] A portion of the first connecting hole and a portion of the second connecting hole (42b) are opposite to each other in the axial direction via the movable member (41). Therefore, even if the flow path cross-sectional area of ​​each of the first connecting hole and the second connecting hole is not adjusted, the frequency of resonance when the liquid travels between the main liquid chamber and the auxiliary liquid chamber via the first connecting hole and the second connecting hole with the input of vibration can be tuned by adjusting the overlapping area of ​​the first connecting hole and the second connecting hole relative to each other in the axial direction via the movable member. Thus, it is not necessary to reduce the flow path cross-sectional area of ​​each of the first connecting hole and the second connecting hole during tuning, so that, for example, when forming the partition member by casting or injection molding, it is not necessary to make the pins for forming the first connecting hole and the second connecting hole thinner, and it is possible to prevent the durability of the pins from decreasing, which makes manufacturing difficult.

[0105] In the above aspect, when viewed from the axial direction, the first communicating hole and the second communicating hole may have shapes different from each other.

[0106] In this case, since the first communication hole and the second communication hole have different shapes when viewed in the axial direction, the overlapping area of ​​the first communication hole and the second communication hole facing each other in the axial direction via the movable member can be easily adjusted.

[0107] In the above aspect, the first communicating hole may be a curved long hole extending along the cylindrical member when viewed in the axial direction.

[0108] In this case, since the first connecting hole is a curved long hole extending along the tubular member when viewed from the axial direction, when the partition member is formed by casting or injection molding, for example, the fluidity of the molten material in the mold cavity can be ensured and the complexity of the mold structure can be prevented.

[0109] In the technical solution, the first communicating holes may be provided in plurality in the first wall surface at intervals in the radial direction, and the second communicating hole may be provided as a long hole extending in the radial direction and facing the plurality of the first communicating holes in the axial direction via the movable member.

[0110] In this case, since the second connecting hole is set as a long hole extending in the radial direction and is opposite to the multiple first connecting holes arranged on the first wall surface in the axial direction via the movable member, it is easy to ensure the overlapping area of ​​the first connecting hole and the second connecting hole relative to each other in the axial direction via the movable member.

[0111] Industrial Applicability

[0112] The present invention can be used for a vibration isolating device that is applied to, for example, automobiles, industrial machinery, etc., and absorbs and attenuates vibrations of vibration-generating parts such as engines.

[0113] Description of Reference Numerals

[0114] 1. Vibration isolation device; 11. First mounting member; 12. Second mounting member; 13. Elastic body; 14. Main liquid chamber; 15. Sub-liquid chamber; 16. Partition member; 16b. First wall surface; 16f. Inner portion; 16g. Outer portion; 19. Liquid chamber; 21. Cylindrical member; 24. Throttling passage; 41. Movable member; 42. Accommodating chamber; 42a. First connecting hole; 42b. Second connecting hole; O. Center axis.

Claims

1. A vibration isolation device, wherein: The vibration isolation device comprises: a first mounting member and a second mounting member, the first mounting member being cylindrical and connected to one of the vibration generating portion and the vibration receiving portion, and the second mounting member being connected to the other of the vibration generating portion and the vibration receiving portion; An elastic body elastically connects the two mounting members; a partition member that partitions a liquid chamber in the first mounting member in which a liquid is sealed into an auxiliary liquid chamber and a main liquid chamber having the elastic body in a part of a partition wall in an axial direction along a central axis of the first mounting member; and a movable member which is accommodated in an accommodation chamber provided in the partition member in a deformable or displaceable manner, The partition member is formed with a throttle passage that connects the main liquid chamber and the auxiliary liquid chamber, a plurality of first communication holes that connect the main liquid chamber and the storage chamber, and a second communication hole that connects the auxiliary liquid chamber and the storage chamber. A cylindrical member having a top opening edge and projecting in the axial direction toward the elastic body is disposed on a first wall surface of the partition member in which the first communication hole is opened and which constitutes a part of the inner surface of the main liquid chamber. The plurality of first communication holes are opened in both an inner portion of the first wall surface located inside the cylindrical member and an outer portion located outside the cylindrical member. A portion of the first communicating hole and a portion of the second communicating hole are opposed to each other in the axial direction via the movable member. A plurality of first communicating holes are provided in the inner portion. When viewed from the axial direction, the first communicating hole and the second communicating hole have shapes different from each other.

2. The vibration isolation device according to claim 1, wherein: The first communication hole is a curved long hole extending along the cylindrical member when viewed from the axial direction.

3. The vibration isolation device according to claim 2, wherein: The first communicating holes are provided in plurality in the first wall surface at intervals in the radial direction. The second communication hole is formed as a long hole extending in the radial direction and is opposed to the plurality of first communication holes in the axial direction via the movable member.

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