ANTIVIBRATION DEVICE

Abstract

Anti-vibration device (10, 80, 100, 110) which is a fluid-filled anti-vibration device and comprises: a rubber-elastic main body (18); an inner shaft part (14); a cylindrical intermediate element (24), wherein the inner shaft part (14) and the cylindrical intermediate element (24) are connected by the rubber-elastic main body (18); an outer cylindrical member (16) inserted from the outside into and fixed to the cylindrical intermediate member (24); a plurality of fluid chambers (38) separated in a circumferential direction and formed by covering pocket-like parts (34) provided on the rubber-elastic main body (18) and opening to an outer peripheral side of the intermediate cylindrical member (24) using the outer cylindrical member (16); and an opening path (40) through which the fluid chambers (38) can communicate with each other, wherein a magnetic functional fluid is filled into the fluid chambers (38), a magnetic field generating unit (56) which applies a magnetic field to the magnetic functional fluid flowing through the opening path (40) is provided outside the fluid chambers (38), the outer cylindrical element (16) is made of a non-magnetic material, the cylindrical intermediate element (24) consists of a ferromagnetic material and in the cylindrical intermediate element (24) an opening part (32) acting on the magnetic field is provided at a position corresponding to the opening path (40) in which the magnetic field is applied to the magnetic functional fluid.

Description

field of technology

[0001] The disclosure relates to a fluid-filled anti-vibration device or a fluid-filled vibration isolator or a fluid-filled vibration damping device that utilizes the flow behavior of a liquid filled in a fluid chamber provided therein, and more particularly relates to a fluid-filled vibration damping device that uses a magnetic functional fluid whose flow properties, etc., change in accordance with a magnetic field change. Technical background

[0002] Conventionally, one type of anti-vibration device is a fluid-filled anti-vibration device that exerts a vibration-damping effect by utilizing the flow behavior of a fluid filled therein with respect to a vibration input between an inner shaft portion and an outer cylindrical member. Such an anti-vibration device is configured in which the inner shaft portion and the outer cylindrical member are connected by a rubber-elastic main body. Such a fluid-filled anti-vibration device is suitable not only for an engine mount of a vehicle, but can also be widely used for a cab mount, a differential mount, a suspension mount, or a vibration-damping bush, among others.

[0003] Since the vibration damping characteristics required for the anti-vibration device change with the input vibration or the driving condition of the vehicle, etc., it is desirable that the vibration damping characteristics, which can be achieved by utilizing the flow behavior of the fluid, can be controlled externally.

[0004] Therefore, Japanese Patent JP H03-9139 A (Patent Document 1) proposes an electro-rheological fluid-filled anti-vibration device. It uses an electro-rheological fluid whose rheological degree changes with the power supply, and the vibration damping characteristics can be switched by controlling the power supplied to the electro-rheological fluid. However, the anti-vibration device described in Patent Document 1 requires that a power supply electrode be provided inside to contact the electro-rheological fluid, and that the electrode be supplied with power from the outside. Therefore, the configuration or manufacturing process can easily become complicated.

[0005] German patent publication DE 10 2011 117 749 A1 (Patent Document 2) proposes an anti-vibration device using a magnetorheological fluid whose rheological degree changes depending on the strength of an applied magnetic field. With the magnetorheological fluid, it is possible to apply and control the magnetic field from outside the fluid chamber. Therefore, it is not necessary to provide an electrode for power supply inside the fluid chamber, as is the case with the electrorheological fluid, and it is possible to simplify the manufacturing configuration of the anti-vibration device compared to the type filled with electrorheological fluid.

[0006] Document DE 11 2021 000 031 T5 discloses a vibration isolating device which is of a liquid-filled type and in which an inner shaft member and an outer tube member are connected to each other with a rubber-elastic main body, and a plurality of liquid-filled liquid chambers are provided which are separated from each other in a circumferential direction and communicate with each other through an orifice passage.

[0007] Document WO 2023 / 286397 A1 discloses a fluid-filled cylindrical vibration damping device in which an inner shaft member and an outer cylindrical member are elastically connected by an elastic main rubber body and a plurality of fluid chambers are communicated with each other via an orifice channel.

[0008] The document US 2020 / 0 263 755 A1 discloses a fluid-filled bushing assembly having an inner tubular element, an outer tubular element arranged coaxially with the inner tubular element, and an elastic element arranged between the inner tubular element and the outer tubular element, wherein not only the stiffness of the fluid-filled bushing assembly in the lateral directions is freely selectable, but also the stiffness of the fluid-filled bushing assembly in the rotational direction and / or the axial direction is freely selectable.

[0009] Document US 11 193 532 B2 discloses a variable stiffness bushing comprising inner and outer tubular elements and an elastic member connecting these tubular elements. At least one pair of circumferentially spaced fluid chambers is defined in the elastic member such that first axial ends and second axial ends of the fluid chambers are defined by first and second end walls of the elastic member, respectively. [Prior art documents][Patent documents] [Patent Document 1] Japanese Patent JP H03- 9 139 A [Patent Document 2] German Patent Specification DE 102011 117 749 A1 Summary of the inventionProblem to be solved by the invention

[0010] However, if a magnetic field generating unit that applies the magnetic field to the magnetorheological fluid is provided outside the fluid chamber, it is difficult to efficiently apply the magnetic field generated by the magnetic field generating unit to the magnetorheological fluid.

[0011] In particular, for example, as in the Fig. 2 and Fig. 3 of Patent Document 1 considers that the magnetic field generation unit is mounted on the outer peripheral surface of the outer cylindrical member in an externally inserted state. However, it does not consider how to efficiently apply the magnetic field generated by such a magnetic field generation unit to an opening path of the magnetorheological fluid filled in the fluid chamber. Therefore, there are problems such as insufficiently exhibiting the vibration damping properties that are the objective, requiring the magnetic field generation unit to have excessive magnetic field generation capability, and poor energy efficiency.

[0012] The object of the present disclosure is to provide an anti-vibration device with a novel configuration in which the magnetic field of the magnetic field generating unit can function efficiently with respect to the magnetorheological fluid filled in the fluid chamber and the vibration damping properties can be switched with favorable energy efficiency. Means to solve the problem

[0013] The following describes exemplary embodiments for understanding the disclosure, but each of the embodiments described below is described as an exemplary example and may be used in combination with others, if appropriate. Several components described in each aspect may also be recognized and adopted independently of each other to the extent possible, and they may also be adopted in combination with any component described in another aspect. Accordingly, the disclosure may be implemented in various alternatives without being limited to the embodiments described below.

[0014] A first aspect of the disclosure is as follows. An anti-vibration device, which is a fluid-filled anti-vibration device, includes: a rubber-elastic main body; an inner shaft member; an intermediate cylindrical member, the inner shaft member and the intermediate cylindrical member being connected to each other by the rubber-elastic main body; an outer cylindrical member inserted from the outside and fixed to the intermediate cylindrical member; a plurality of fluid chambers separated in a circumferential direction and formed by covering pocket-like parts provided on the rubber-elastic main body, which open to an outer peripheral side of the intermediate cylindrical member using the outer cylindrical member; and an opening path that allows the fluid chambers to communicate with each other. A magnetic functional fluid is filled into the fluid chambers.A magnetic field generating unit, which applies a magnetic field to the magnetic functional fluid flowing through the orifice path, is provided outside the fluid chambers. The outer cylindrical member is made of a non-magnetic material. The intermediate cylindrical member is made of a ferromagnetic material. An orifice portion acting on the magnetic field is provided in the intermediate cylindrical member at a position corresponding to the orifice path, where the magnetic field is applied to the magnetic functional fluid.

[0015] In the anti-vibration device according to this aspect, the fluid filled in the fluid chambers is a magnetic functional fluid whose rheological degree changes with the magnetic field applied by the magnetic field generating unit. Therefore, by controlling the magnetic field applied by the magnetic field generating unit in accordance with an input vibration, for example, to change the characteristics of the anti-vibration device, favorable vibration damping properties can be achieved.

[0016] Specifically, in the anti-vibration device according to the aspect, the outer cylindrical member arranged to cover the outer periphery of the fluid chamber is configured to be a non-magnetic material. Therefore, the magnetic field from the magnetic field generating unit can be prevented from being shielded or reduced by the outer cylindrical member, and the magnetic field from the magnetic field generating unit can be effectively applied to the magnetic functional fluid.

[0017] Furthermore, in the anti-vibration device according to the aspect, the cylindrical intermediate member made of a ferromagnetic material is adopted, and the opening part acting on the magnetic field is provided at a position corresponding to the opening path in the cylindrical intermediate member. Therefore, the magnetic field from the magnetic field generation unit can be efficiently guided to the opening path through the cylindrical intermediate member. That is, for example, the magnetic field from the magnetic field generation unit is efficiently guided to the vicinity of the opening path through the cylindrical intermediate member, and the thus guided magnetic field can be applied to the opening path from the cylindrical intermediate member through the opening part acting on the magnetic field. Furthermore, in the case where a magnetic flux concentrating element, etc., which will be described later, is arranged to facilitate the concentration of the magnetic flux toward, for example, the forming portion of the opening path, the concentrated magnetic flux can be prevented or suppressed from escaping through the cylindrical intermediate member by using the opening part acting on the magnetic field, whereby it is also advantageous to concentrate the magnetic flux on the opening path.

[0018] Accordingly, in the anti-vibration device according to the aspect, it is possible to appropriately use the cylindrical intermediate member to fix the outer cylindrical member to the outer peripheral side of the rubber-elastic main body, ensuring the fluid-tightness of the fluid chambers, and allowing the magnetic flux from the magnetic field generating unit to efficiently act on the magnetic functional fluid of the orifice path. As a result, a novel anti-vibration device capable of switching the vibration-damping properties with favorable energy efficiency can be realized.

[0019] According to a second aspect of the disclosure, in the anti-vibration device of the first aspect, the cylindrical intermediate member includes: a pair of axial direction side portions configured in a cylindrical shape with a large diameter that is continuous in the circumferential direction; and an axial direction intermediate portion partially provided in the circumferential direction and having a concave groove shape extending in the circumferential direction between the pair of axial direction side portions. The opening part acting on the magnetic field is provided at the axial direction intermediate portion.

[0020] In the anti-vibration device according to the aspect, the concave, groove-shaped intermediate portion in the axial direction provided in the cylindrical intermediate member is used, and the opening path can be formed in such a concave, groove-shaped interior space. The deformation of the opening path due to the deformation of the rubber-elastic main body, resulting from, for example, input vibration, can also be suppressed by the intermediate portion in the axial direction provided in the cylindrical intermediate member.

[0021] According to a third aspect of the disclosure, in the anti-vibration device of the second aspect, the cylindrical intermediate member is a single component formed by the pair of axial direction side portions connected at the axial direction intermediate portion, and the magnetic field acting opening portion is configured by a window portion formed to pass through a groove bottom portion in the axial direction intermediate portion configured as the concave groove shape.

[0022] In the anti-vibration device according to the aspect, the opening part acting on the magnetic field is provided in the cylindrical intermediate member, the entire cylindrical intermediate member can be a single component, and it is possible to manage the components or simplify the manufacture of the anti-vibration device.

[0023] According to a fourth aspect of the disclosure, in the anti-vibration device according to the second aspect, the cylindrical intermediate member is configured in a split configuration on two sides in the axial direction in the intermediate portion in the axial direction, and the pair of side portions in the axial direction are separate components, and the magnetic field acting opening part is configured between split parts of the intermediate portion in the axial direction separately in the axial direction.

[0024] In the anti-vibration device according to the aspect, since the cylindrical intermediate member is arranged as separate components from each other on both sides in the axial direction through the opening part acting on the magnetic field, the cylindrical intermediate member is substantially divided in the axial direction in the periphery of the magnetic field acting part as well. Therefore, it is possible to prevent the magnetic flux acting on the opening path from escaping because the magnetic path is formed, for example, in a continuous section on the periphery of the opening part acting on the magnetic field in the cylindrical intermediate member.

[0025] According to a fifth aspect of the disclosure, in the anti-vibration device according to any one of the first to fourth aspects, the magnetic field generating unit is arranged on an outer peripheral side of the outer cylindrical member.

[0026] In the anti-vibration device according to the aspect, it is possible to avoid the influence of the fluid chamber or the rubber-elastic main body on the space in which the magnetic field generation unit is arranged, while performing adjustment with a greater degree of freedom on the outer peripheral side of the outer cylindrical member. Specifically, in the aspect, by forming the outer cylindrical member with a non-magnetic material, it is possible to enable the magnetic field from the magnetic field generation unit arranged on the outer peripheral side of the outer cylindrical member to function efficiently by forming the opening path such that the opening path extends, for example, along the inner peripheral surface of the outer cylindrical member.

[0027] According to a sixth aspect of the disclosure, in the anti-vibration device according to any one of the first to fifth aspects, magnetic flux concentrating elements made of a ferromagnetic material are arranged in the opening path so as to oppose each other in a width direction of the opening path, and the opening part acting on the magnetic field in the cylindrical intermediate member is provided at a position corresponding to a portion between opposing parts in the magnetic flux concentrating elements.

[0028] In the anti-vibration device according to the aspect, by disposing the magnetic flux concentrating member at the shaping portion of the opening path, the magnetic flux acting on the opening path is further concentrated.

[0029] According to a seventh aspect of the disclosure, in the anti-vibration device of the sixth aspect, an opening member for forming the opening path is arranged between the intermediate cylindrical member and the outer cylindrical member so as to extend in the circumferential direction along the pocket-like part provided in the rubber-elastic main body, the opening member being formed of a ferromagnetic material, and the magnetic flux concentrating elements arranged to oppose each other in the width direction of the opening path are formed by the opening member.

[0030] In the anti-vibration device according to this aspect, with the nozzle member extending to the opening part of the pocket-like part, a large degree of freedom can be ensured with respect to the length of the nozzle path, etc. Moreover, it is possible to efficiently allow the magnetic flux to act on the magnetic functional fluid in the opening path by using the opening member.

[0031] According to an eighth aspect of the disclosure, in the anti-vibration device according to any one of the first to seventh aspects, the magnetic field generating unit comprises: a coil element that generates a magnetic field by being energized, and a yoke part that guides a magnetic flux in the magnetic field generated by the coil element to the opening path

[0032] In the anti-vibration device according to this aspect, it is possible to efficiently guide the magnetic flux from the coil element for generating a magnetic field to the magnetic functional fluid of the opening path via the yoke part, and it is possible to easily control the magnetic flux density acting on the magnetic functional fluid by controlling the power supplied to the coil element and the resulting vibration damping properties.

[0033] Furthermore, in this aspect, it is possible to use part or all of the intermediate sleeve, for example, as the yoke part, and it is also possible to use the magnetic flux concentrating element according to the sixth or seventh aspect as the yoke part, for example. Accordingly, such a yoke part can be configured with a fewer number of components or a simpler configuration. Effect of the invention

[0034] According to the disclosure, in the anti-vibration device whose vibration damping properties can be changed by controlling the magnetic field applied by the magnetic field generating unit provided outside the fluid chamber to the magnetorheological fluid filled in the fluid chamber, the magnetic field from the magnetic field generating unit can function efficiently with respect to the magnetorheological fluid filled in the fluid chamber. As a result, an anti-vibration device with a novel configuration capable of switching the vibration damping properties with favorable energy efficiency can be realized. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing an engine mount in a first embodiment of the disclosure, and corresponds to a II cross-section of Fig. 2. Fig. 2 is a cross-sectional view of II-II from Fig. 1. Fig. 3 is a perspective view in which an outer cylindrical member in a bearing body which is the Fig. 1 shown engine mount is removed. (a) of Fig. 4 is a perspective view showing an intermediate sleeve which Fig. 1 shown engine mount, (b) of Fig. 4 is a front view showing the intermediate sleeve, and (c) of Fig. 4 is a longitudinal sectional view showing the intermediate sleeve. Fig. 5 is a cross-sectional view showing an engine mount as a second embodiment of the disclosure, and corresponds to a IV-IV cross-section of Fig. 6. Fig. 6 is a cross-sectional view of VI-VI from Fig. 5. Fig. 7 is a perspective view in which an outer cylindrical member in a bearing body which is the Fig. 5, is removed. Fig. Figure 8 is a plan view of an opening element that opens the motor mount of Fig. 5 forms. Fig. 9 is a cross-sectional view showing a motor mount as a third embodiment of the disclosure. Fig. 10 is a plan view of an opening element that opens the motor mount of Fig. 9 forms. Fig. 11 is a cross-sectional view showing a part of an engine mount as a fourth embodiment of the disclosure. (a) of Fig. Fig. 12 is a perspective view showing another aspect of an intermediate sleeve that can be used in embodiments 1 to 4 of the disclosure, (b) of Fig. 12 is a front view of the intermediate sleeve, and (c) of Fig. 12 is a longitudinal sectional view of the intermediate sleeve. (a) of Fig. 13 is a perspective view illustrating another aspect of an intermediate sleeve that can be used in embodiments 1 to 4 of the disclosure, (b) of Fig. 13 is a front view of the intermediate sleeve, and (c) of Fig. 13 is a longitudinal sectional view of the intermediate sleeve. (a) of Fig. 14 is a perspective view illustrating another aspect of an intermediate sleeve that can be used in embodiments 1 to 4 of the disclosure, (b) of Fig. 14 is a front view of the intermediate sleeve, and (c) of Fig. 14 is a longitudinal sectional view of the intermediate sleeve. DETAILED DESCRIPTION

[0035] In the following, the embodiments of the disclosure will be described with reference to the drawings.

[0036] In Fig. 1 to 2, an engine mount 10 for a motor vehicle is shown as a first embodiment of an anti-vibration device configured according to the disclosure. The engine mount 10 is a fluid-filled anti-vibration device and has a bearing body 12 with a configuration in which an inner shaft portion 14 and an outer cylindrical member 16 are connected by a rubber-elastic main body 18. Fig. 3 shows a state in which the outer cylindrical member 16 is removed from the bearing body 12. In the following descriptions, the axial direction basically refers to the left-right direction of Fig. 1, which is a central axis direction of the bracket, and the up-down direction refers to the up-down direction of Fig. 2, which is a main vibration input direction.

[0037] The inner shaft part 14 has a substantially cylindrical shape with a small diameter and extends linearly in the axial direction. The material of the inner shaft part 14 is not particularly limited, and a ferromagnetic material such as an iron-based material can also be used. However, if there is a concern that the inner shaft part 14 may have an adverse influence on a magnetic field generated by a magnetic field generating unit (56) to be described later, for example, the inner shaft part 14 may also be formed using a non-magnetic material such as stainless steel or an aluminum alloy.

[0038] A stopper member 20 is fixed in the axial direction to the central portion of the inner shaft part 14. The stopper member 20 has a substantially annular shape overall and is fixed to the inner shaft part 14 in an externally inserted state. As shown in Fig. 2, the inner shaft part 14 includes two protrusion parts 22, 22 projecting toward the sides in the upper and lower directions. Although the stopper member 20 is not necessarily required, in the case where the stopper member 20 is adopted, if the stopper member 20 has an adverse effect on the magnetic field generated by the magnetic field generating unit (56) to be described later, the stopper member 20 may be formed by using a non-magnetic material such as a synthetic resin, a rubber elastic body, or an aluminum alloy, etc.

[0039] In addition, an intermediate sleeve 24 is arranged as a cylindrical intermediate element on the circumference of the inner shaft part 14. The intermediate sleeve 24 is, as shown in the individual views (a) to (c) of Fig. 4, is formed in a substantially cylindrical shape with a larger diameter than the inner shaft part 14, and is arranged in an externally inserted state and separated in the radial direction from the inner shaft part 14. The inner shaft part 14 and the intermediate sleeve 24 (and the outer cylindrical member 16) may also be eccentric in the radial direction, but these components are arranged substantially on the same central axis in this embodiment.

[0040] The intermediate sleeve 24 is made of a ferromagnetic material. For example, an iron-based metal can be used. Compared to the case where a non-magnetic material, such as an aluminum alloy, is used, the strength properties of the intermediate sleeve 24 are secured while reducing manufacturing costs and simplifying processing.

[0041] The intermediate sleeve 24 includes window parts 26, 26 at two locations in the circumferential direction. In this embodiment, a pair of window parts 26, 26 are arranged at opposite positions in the top-down direction (the top-down direction in Fig. 1). Each window part 26 penetrates the inside and outside of the intermediate sleeve 24 in the thickness direction at the central portion of the intermediate sleeve 24 in the axial direction and has a substantially rectangular shape that is wide in the circumferential direction and has a predetermined width in the axial direction.

[0042] Between the two window parts 26, 26 of the intermediate sleeve 24 in the axial direction, groove-like parts 28 are provided, each extending in the circumferential direction and at opposite positions in the left-right direction of Fig. 2. Each groove-like part 28 is a section configured with a small diameter in the intermediate portion of the intermediate sleeve 24 in the axial direction and in a concave groove shape open to the outer peripheral surface. The groove-like part 28 extends in the circumferential direction of the intermediate sleeve 24. The two ends of the groove-like part 28 in the circumferential direction each reach the two window parts 26, 26.

[0043] In short, the intermediate sleeve 24 has a pair of side portions 29, 29 in the axial direction which are continuous in the circumferential direction and arranged in a cylindrical shape with a large diameter, and an intermediate portion in the axial direction is provided integrally with the groove-like parts 28, 28 which are partially provided in the circumferential direction, and extends in the circumferential direction between and connects the pair of side portions 29, 29 in the axial direction.

[0044] Furthermore, in the intermediate sleeve 24, at a bottom wall portion 30 of each groove-like part 28 forming the intermediate portion in the axial direction, a magnetic field acting opening portion 32 is formed in the form of a through hole penetrating the inside and outside. In the embodiment, the magnetic field acting opening portion 32 is formed in a substantially rectangular shape at the central portion of the bottom wall portion 30, so that the bottom wall portion 30 of each groove-like part 28 remains in the shape of a surrounding rectangular frame.

[0045] Furthermore, the inner shaft part 14 and the intermediate sleeve 24 are connected by the rubber-elastic main body 18. The rubber-elastic main body 18 has a thick, substantially cylindrical shape, the inner peripheral portion of the rubber-elastic main body 18 is fixed to the inner shaft part 14, and the outer peripheral portion of the rubber-elastic main body 18 is fixed to the intermediate sleeve 24. Furthermore, the rubber-elastic main body 18 extends into the groove inner surface of the groove-like part 28 through the magnetic field acting opening part 32, etc., of the intermediate sleeve 24, and is also fixed to the outer peripheral surface of the intermediate sleeve 24 in the groove-like part 28. In this way, the rubber-elastic main body 18 is formed as an integrally vulcanized molded article including the inner shaft part 14 and the intermediate sleeve 24.

[0046] As in Fig. As shown in FIG. 2, the rubber-elastic main body 18 includes two pocket-like parts 34, 34. The pocket-like parts 34, 34 are each configured like a depression or a recess open to the outer peripheral surface of the rubber-elastic main body 18, and are open in each direction in the upper-lower direction in the embodiment. The pair of pocket-like parts 34, 34 are provided at positions corresponding to the pair of window parts 26, 26 of the intermediate sleeve 24. Opening peripheral parts of the pocket-like parts 34, 34 are fixed to the opening frame parts of the window parts 26, 26, and each pocket-like part 34 is open toward the outer peripheral side through each window part 26. Furthermore, the projection parts 22, 22 of the stopper element 20 protrude at a middle height in the depth direction of the pocket-like parts 34, 34 substantially in the center of the respective bottom parts of the pocket-like parts 34, 34.

[0047] Furthermore, the outer cylindrical member 16 is inserted from the outside into the integrally vulcanized molded part of the rubber-elastic main body 18, and the outer cylindrical member 16 is fitted and fixed from the outside to the intermediate sleeve 24 to be assembled. The outer cylindrical member 16 has a substantially cylindrical shape with a larger diameter than the inner shaft part 14. The outer cylindrical member 16 is made of a non-magnetic material, such as stainless steel or an aluminum alloy.

[0048] In this embodiment, the inner peripheral surface of the outer cylindrical member 16 is completely covered with a thin sealing rubber layer 36. Furthermore, the outer cylindrical member 16 is fitted and secured to the intermediate sleeve 24 by a diameter reduction process such as eight-fold pressing. Furthermore, the outer cylindrical member 16 and the intermediate sleeve 24 are filled with a fluid-tight seal by the sealing rubber layer 36 therebetween.

[0049] Accordingly, the bearing body 12 is configured by attaching the outer cylindrical member 16 to the outer peripheral surface of the integrally vulcanized molded rubber elastic main body 18 including the inner shaft portion 14 and the intermediate sleeve 24, and a fluid-filled region fluidly divided with respect to the outside space is formed inside such a bearing body 12.

[0050] This fluid-filled area includes two fluid chambers 38, 38 formed by covering the pair of pocket-like parts 34, 34 of the rubber-elastic main body 18 using the outer cylindrical member 16. The fluid chambers 38, 38 are circumferentially separated from each other. In the embodiment, the two fluid chambers 38, 38 are arranged on two sides in the upper-lower direction by sandwiching the inner shaft part 14.

[0051] The partition wall between the two fluid chambers 38, 38 in the circumferential direction and the wall parts on both sides of each separation chamber 38 in the axial direction are all formed by the rubber-elastic main body 18. In addition, at the time when a vibration in the upper-lower direction in Fig. 1, together with the relative displacement of the inner shaft part 14 and the outer cylindrical member 16 in a perpendicular direction to elastically deform the rubber-elastic main body 18, causes a relative pressure change between the two fluid chambers 38, 38. Moreover, in each fluid chamber 38, the protrusion part 22 of the stopper member 20 protrudes from the inside to the outside in the radial direction, and the tip surface of the protrusion part 22 faces the outer cylindrical member 16 with a predetermined distance therebetween. Furthermore, with contact between each protrusion part 22 and the outer cylindrical member 16, a stopper mechanism is formed that limits the amount of elastic deformation of the rubber-elastic main body 18 at the time when the vibration is input.

[0052] A magnetic functional fluid 39 is filled into the fluid-filled area comprising the pair of fluid chambers 38, 38. The magnetic functional fluid 39 may be a fluid whose rheological degree is changed by the action of a magnetic field. The magnetic functional fluid 39 may be, for example, a magnetorheological fluid (MRF), a magnetic fluid (MF), or a magnetic composite fluid (MCF) that mixes MRF and MF. As the magnetic functional fluid 39, a fluid whose rheological degree changes significantly with respect to the change in the magnetic flux density of an applied magnetic field may be used, and an MCF whose magnitude of increase in the rheological degree can be easily adjusted according to the mixing ratio between MRF and MF may also be used.

[0053] The magnetic functional fluid 39 is, for example, a suspension or a colloidal solution in which ferromagnetic fine particles are dispersed in a base fluid such as water, oil, etc., and the surfaces of the ferromagnetic fine particles are coated with a surfactant, making it difficult for the ferromagnetic fine particles to aggregate or settle in the base fluid. Alternatively, aggregation, etc., can be avoided or mitigated by dispersing the ferromagnetic fine particles in a base fluid with the addition of a surfactant.

[0054] The ferromagnetic fine particles are metal particles such as iron, ferrite, magnetite, etc., and the particle diameter can range from about 8 nm to about 10 μm. There are no particular restrictions on the base liquid as long as the fine ferromagnetic particles can be dispersed. For example, water, isoparaffin, alkyl naphthalene, perfluoropolyether, polyolefin, silicone oil, etc. can be used. In addition, the base liquid can be an incompressible liquid. The surfactant can be selected according to the base liquid, for example, oleic acid, etc. can be used. MRF and MF mainly differ in the particle diameter of the ferromagnetic fine particles. The particle diameter of the ferromagnetic fine particles in MRF is larger than that of MF.

[0055] In particular, the above description regarding the magnetic functional fluid provides several examples of the magnetic functional fluid 39, and, as mentioned above, the magnetic functional fluid that can be adopted in the invention should not be interpreted as being limited by this description.

[0056] The fluid chambers 38, 38, into which such a magnetic functional fluid 39 is filled, communicate with each other through orifice paths 40, 40, which form the fluid-filled area as the fluid chambers 38, 38. The respective orifice paths 40 extend in the circumferential direction from two ends of the respective fluid chambers 38, 38 in the circumferential direction, and the pair of fluid chambers 38, 38 communicate with each other.

[0057] In the embodiment, in the pair of groove-like parts 28, 28 of the intermediate sleeve 24, an opening groove 41 is formed in the rubber-elastic main body filled in each groove-like part 28, and the opening path 40 is formed by covering such an opening groove 41 using the outer cylindrical member 16. The opening groove 41 extends in a substantially constant cross-sectional shape over the entire circumferential length within each groove-like part 28 of the intermediate sleeve 24.

[0058] Furthermore, a magnetic flux concentrating member 42 made of a ferromagnetic material such as iron is housed and arranged in each opening groove 41. In the embodiment, a pair of magnetic flux concentrating members 42 are installed at the ends on both sides of the opening groove 41 in the groove width direction (axial mounting direction). The pair of magnetic flux concentrating members 42, 42 extend in the circumferential direction in an arcuate shape with a substantially constant rectangular cross section and are positioned and fixed in the opening groove 41 by attaching the pair of magnetic flux concentrating members 42, 42 to both sides of the opening groove 41 in the groove width direction and pressing the outer peripheral surfaces thereof with the outer cylindrical member 16.As a result, the magnetic flux concentrating elements 42 and 42 are arranged in a filled state over the entire length on the both sides of the opening groove 41 in the groove width direction, and the opening path 40, which allows the fluid to flow between the pair of fluid chambers 38, 38, is formed between the opposite surfaces of the pair of magnetic flux concentrating elements 42, 42.

[0059] In the embodiment, a positioning protrusion 44 located at the center of the opening groove 41 in the groove width direction, protruding from a groove bottom surface, and extending in the circumferential direction is formed by the rubber-elastic main body extending into the groove of the intermediate sleeve 24 for the opening groove 41. By fitting the positioning protrusion 44 between the opposing surfaces of the pair of magnetic flux concentrating elements 42, the dimensions of the opposing surfaces of the pair of magnetic flux concentrating elements 42, 42 and the flow path cross-sectional area of ​​the opening path 40 are accurately and stably adjusted. The magnetic flux concentrating elements 42, 42 can also be bonded to each other using a non-magnetic material and positioned by contact with a rubber-elastic body, although the positioning protrusion 44 is not necessarily required.

[0060] Furthermore, a cylindrical cover member 46 is installed on the bearing body 12 in an externally inserted state, and a housing for a magnetic field generating unit is formed by the outer cylindrical member 16 and the cylindrical cover member 46. The cylindrical cover member 46 has a substantially cylindrical shape with a larger diameter than the outer cylindrical member 16. The material of the cylindrical cover member 46 is not particularly limited, and a metal material with high strength or high rigidity can be used as needed.

[0061] Furthermore, the magnetic field generating unit 56 is mounted in a state in which it is positioned by elastic support bodies 52, 54 between the outer cylindrical member 16 and the cylindrical cover member 46, which are positioned in the axial and radial directions to each other.

[0062] The magnetic field generating unit 56 as a whole is substantially annular and has a configuration in which a yoke part 60 is attached to the periphery of a coil 58. The coil 58 generates a magnetic field by being supplied with current, and a conventional component can be used as the coil 58. Generally, the coil has a winding structure in which an electric wire with an insulating coating is wound around a bobbin, and, if necessary, its entirety may be coated with an insulating resin. In the present embodiment, for example, a large-diameter air-core coil structure in which an electric wire is wound circumferentially along the outer peripheral surface of the outer cylindrical member 16 can be used.The two ends of the electric wire of such a coil 58 are drawn out in the axial direction at a position of the circumference and are conductively connected to a terminal part 66 of a connector 64, and an external electric control device not shown here is electrically connected to the two ends of the coil 58 via the connector 64.

[0063] The yoke part 60 is made of a ferromagnetic material such as iron. The yoke part has a substantially C-shaped cross section open toward the inner circumference and is arranged to cover two end surfaces of the coil 58 in the axial direction and the outer peripheral surface of the coil 58. Moreover, the open end surface of the yoke part 60 on the inner peripheral side is mounted in a state of abutting against or close to the outer peripheral surface of the outer cylindrical member 16. The two end surfaces of the yoke part 60 in the axial direction and the outer peripheral surface of the yoke part 60 are fixedly positioned and supported with respect to the housing of the magnetic field generating unit formed by the outer cylindrical member 16 and the cylindrical cover member 46 via the elastic support bodies 52, 54.

[0064] Accordingly, the magnetic flux generated by the energization of the coil 58 is guided to the yoke part 60, which is a ferromagnetic material, and the leakage of the magnetic flux to the outside in the axial direction or to the outer peripheral side is suppressed. Although the magnetic flux guided by the yoke part 60 is released from the opening ends of both sides in the axial direction on the inner peripheral side of the yoke part 60 to the outside of the yoke part 60, the magnetic flux concentrating members 42, 42 and the intermediate sleeve 24 formed of a ferromagnetic material are arranged to be relatively close to the inner peripheral side of the yoke part 60 via the outer cylindrical member 16 or the sealing rubber layer 36 formed of a non-magnetic material.Therefore, the magnetic flux generated by the current supply to the coil 58 is guided from the inner peripheral side of the yoke part 60 to the magnetic flux concentrating elements 42, 42 and the intermediate sleeve 24 and forms a magnetic path on the inner peripheral side of the coil 58.

[0065] Here, the magnetic flux concentrating elements 42, 42 forming such a magnetic path are separated by the aperture path 40, and the opposing surfaces of the pair of magnetic flux concentrating elements 42 in the axial direction form magnetic pole surfaces that sandwich the aperture path 40 on the magnetic path and oppose each other. Furthermore, in the intermediate sleeve 24, the magnetic path is separated at a position corresponding to the aperture path 40 by the aperture part 32 acting on the magnetic field. Therefore, the magnetic poles applied to the opposing surfaces of the magnetic flux concentrating elements 42, 42 in the axial direction, which are the magnetic pole surfaces, can be prevented from leaking into the intermediate sleeve 24.Furthermore, even if there is a magnetic flux guided from the yoke part 60 to the intermediate sleeve 24, this magnetic flux is also easily guided to the magnetic flux concentrating elements 42, 42 by increasing the magnetic path resistance on the intermediate sleeve 24 through the use of the opening part 32 acting on the magnetic field. As a result, the magnetic flux density can be increased between the opposing surfaces of the magnetic flux concentrating elements 42, 42 in the axial direction, which form the magnetic pole surfaces sandwiching the opening path 40 and facing each other.

[0066] Furthermore, the intermediate sleeve 24 includes two cylindrical side portions 29, 29 in the axial direction. These axial side portions 29, 29 are integrally connected, and the groove-like part 28 is formed. Therefore, the magnetic flux released from the opening ends of the two sides of the yoke part 60 in the axial direction over the entire circumference in the circumferential direction is also captured by the two cylindrical side portions 29, 29 in the axial direction and guided by the groove-like parts 28 to the opening path 40 between the opposing surfaces of the magnetic flux concentrating elements 42, 42, whereby the magnetic force on the magnetic functional fluid 39 can function more efficiently.

[0067] In this way, in the motor mount 10 of the embodiment, the magnetic flux generated by supplying power to the coil 58 is concentrated on and acts on the orifice path 40, and a large magnetic force can be exerted on the magnetic functional fluid 39 flowing through the orifice path 40. In short, a magnetic energy applied to the magnetic functional fluid 39 of the orifice path 40 relative to the power supplied to the magnetic field generating unit 56 can be efficiently obtained.

[0068] It should be noted that the specific shape, such as the cross-sectional area of ​​the path, the length, etc., of the orifice path 40 can be appropriately adjusted so that the flow behavior of the fluid meets the required vibration damping characteristics, and the specific shape is not particularly limited.

[0069] Furthermore, by forming such an opening path 40 between the opposing surfaces of the magnetic flux concentrating elements 42 over the entire length, as shown in the embodiment, it is possible to increase the effect of the magnetic force with respect to the magnetic functional fluid 39 in the opening path 40. However, the disclosure is not limited to such a configuration. For example, the magnetic flux concentrating elements 42, 42 may also be partially arranged in the longitudinal direction of the opening path 40. Furthermore, in addition to forming the respective entire areas of the pair of opposing surfaces in the path cross section of the opening path 40 by using the magnetic flux concentrating elements 42, 42, it is also possible to partially form the pair of opposing surfaces in the path cross section of the opening path 40 by using the magnetic flux concentrating elements 42, 42.

[0070] It should be noted that, regarding the ends of the respective magnetic flux concentrating elements 42 on the outer sides in the axial direction, one that is close to the corresponding opening end of the yoke part 60 on the inner peripheral side in the axial direction is advantageous from the perspective of concentrating the magnetic flux or reducing the magnetic resistance on the magnetic path. For example, it may be configured so that each magnetic flux concentrating element 42 is at least partially overlapped with each opening end of the yoke part 60 on the inner peripheral side in the projection of the radial direction.Furthermore, in the embodiment, the end of each magnetic flux concentrating element 42 on the outer side in the axial direction is separated from the inner side in the axial direction with respect to each opening end of the yoke part 60 on the inner peripheral side, and the two components are not overlapped in the projection of the radial direction. However, the distance in the axial direction defined as D may be small. Regarding the opening width of the yoke part 60 on the inner peripheral side defined as B, it can be set that D≦(2 / 3)B.

[0071] Regarding the facilitation of the action of the magnetic field on the magnetic functional fluid 39 in the opening path 40 by providing a magnetic gap-like magnetic path separating part which is arranged in the region in which the magnetic field generated by the magnetic field generating unit 56 acts and which is located at a position corresponding to the opening path 40, the opposing surfaces between the magnetic flux concentrating element 42, 42 and the opening part 32 acting on the magnetic field of the intermediate sleeve 24 can also be considered to be substantially the same.

[0072] Therefore, the magnetic field acting opening part 32 of the intermediate sleeve 24 is located on the inner peripheral side of the opening path and is formed at a position corresponding to the opening path so as to overlap with the opening path in the radial direction projection. Although the size and shape of the magnetic field acting opening part 32 are not particularly limited, the axial direction width dimension of the magnetic field acting opening part 32 can be set to correspond to a path width of the opening path 40 or more, taking into account the rate of increase of the magnetic flux acting on the opening path 40.Particularly, in the embodiment in which the opening path 40 is formed between the opposite surfaces of the pair of magnetic flux concentrating elements 42, 42, the concentration of the magnetic flux on the magnetic flux concentrating elements 42, 42 is taken into account, and the width dimension of the opening part 32 acting on the magnetic field in the axial direction can be set to be larger than the distance between the opposite surfaces of the pair of magnetic flux concentrating elements 42, 42.

[0073] Furthermore, the magnetic field acting opening part 32 may be formed in a length over the entire length of the opening path 40 in the path longitudinal direction (in the embodiment, the mounting circumferential direction) of the opening path 40, taking into account the rate of increase of the magnetic flux acting on the opening path 40. Specifically, the magnetic field acting opening part 32 does not need to extend over the entire length of the nozzle path, but may be arranged over a part of the entire length. The magnetic field acting opening part 32 may be set to extend over a length of half or more of the nozzle path in the longitudinal direction, to extend over a length of 60% or more of the nozzle path in the longitudinal direction, or to extend over a length of 80% or more of the nozzle path in the longitudinal direction, as appropriate.Therefore, in this embodiment, in the middle section of the opening path, with the exception of the two end sections, the opening part 32 acting on the magnetic field extends over the length of substantially 80% of the total length of the opening path.

[0074] At the two axial direction side portions of the magnetic field acting opening portion 32, the intermediate sleeve 24 overlaps with the respective opening ends of the yoke portions 60 on the inner peripheral side in the radial direction projection. Specifically, in the embodiment, the axial direction side portions 29, 29, which are set with a large diameter in the intermediate sleeve 24, are arranged to overlap with the respective opening ends of the yoke portion 60 on the inner peripheral side in the radial direction projection. Accordingly, the leakage magnetic flux leaking from the yoke portion 60 and discharged to the outside from a closed magnetic path (the magnetic path passing through the magnetic flux concentrating elements 42, 42 or the intermediate sleeve 24 and the opening path 40) is reduced.

[0075] The engine mount 10 of the above-described embodiment is mounted on a vehicle, for example, by mounting the inner shaft portion 14 on a drive unit 68 as a component on one side in the vibration damping linkage, and by mounting the cylindrical cover element 46, which is fastened to the outer cylindrical element 16, on a vehicle body 70 as a component on the other side in the vibration damping linkage. The cylindrical cover element 46 is, for example, pressed into a mounting hole 72 in the vehicle body 70 and fastened to the vehicle body 70. The inner shaft portion 14 can also be fastened to the drive unit 68 via an inner bracket (not shown here). Likewise, the cylindrical cover element 46 can be attached to the vehicle body 70 via an outer bracket (not shown here).

[0076] In the above-described state of the engine mount 10 being mounted on the vehicle, when vibration in the up-down direction in which the fluid chambers 38, 38 are arranged opposite to each other is applied to the engine mount 10, a flow of the filled fluid (the magnetic functional fluid 39) flowing through the opening path 40 between the fluid chambers 38, 38 is generated, and a vibration damping effect is exerted based on the flow behavior of the fluid.

[0077] In the motor mount 10, it is possible to control the rheological degree of the magnetic functional fluid 39 by controlling the magnetic field applied to the magnetic functional fluid 39 when the filled fluid flows through the orifice path 40 by controlling the power supplied to the coil 58 using the magnetic field generating unit 56. Specifically, in the magnetic field generating unit 56, the magnetic field formed on the periphery of the coil 58 and applied to the inside of the bearing body 12 through the yoke part 60 by supplying current to the coil 58 as described above efficiently and intensively acts on the magnetic functional fluid 39 within the orifice path 40 by using the magnetic flux concentrating elements 42, 42 arranged at the positions corresponding to the orifice path 40 and the intermediate sleeve 24 including the orifice parts 32 acting on the magnetic field.

[0078] Since the rheological degree of the magnetic functional fluid 39 changes depending on the strength of the applied magnetic field, by switching the power supply on and off or by stepwise or continuously controlling the current supply to the coil 58, the rheological properties of the magnetic functional fluid 39 within the orifice path 40 and the flow behavior of the magnetic functional fluid 39 flowing through the orifice path 40 are controlled. Thus, the properties (vibration damping properties) of the motor mount 10 can be switched and controlled. The modes for switching the properties of the motor mount 10 are not particularly limited, and the properties can be switched stepwise or continuously between two or more modes to meet the required vibration damping properties.

[0079] In this embodiment, since it is possible to efficiently obtain the magnetic energy supplied to the magnetic functional fluid 39 of the orifice path 40 with respect to the power energy supplied to the magnetic field generating unit 56 as described above, the switching control of the performance (vibration damping properties) of the motor mount 10 can be easily realized as a large property change with favorable energy efficiency.

[0080] Moreover, in the motor mount 10 of the embodiment, the magnetic field generating unit 56 is arranged separately from the fluid-filled portion and on the outer peripheral side of the outer cylindrical member 16, and is configured as a separate configuration from the outer bearing body 12, so that the configuration including the magnetic field generating unit 56 is simplified, and the power supply configuration of the magnetic field generating unit 56 can be formed independently of the bearing body 12, thereby making manufacturing or management easy.

[0081] In Fig. 5 to 6, an engine mount 80 of a motor vehicle is illustrated as a second embodiment of a fluid-filled anti-vibration device configured according to the disclosure. The engine mount 80 of the illustrated embodiment differs from the first embodiment in the configuration of the opening path and the path length of the opening path. Components and portions substantially the same as those of the first embodiment are denoted by the same symbols as those of the first embodiment, and descriptions thereof are omitted.

[0082] As from Fig. As can be seen from Figure 7, which shows the bearing body 12 with the outer cylindrical member 16 removed, the motor mount 80 of the embodiment includes a pair of orifice members 82, 82 that form a circumferentially long orifice path 81 by being serially connected to each other in the circumferential direction. Such a pair of orifice members 82, 82 is used instead of each pair of magnetic flux concentrating members 42, 42 in the motor mount 10 of the first embodiment.

[0083] That is, each orifice member 82 is formed using the same material (ferromagnetic material) as the magnetic flux concentrating member of the first embodiment and has a substantially semi-cylindrical shape with a circumferential length of less than half the entire circumference. Furthermore, the pair of orifice members 82, 82 abuts at one end in the circumferential direction and is installed on the integrally vulcanized molded part of the rubber-elastic main body 18 in a state of extending along the outer peripheral portion by a length of less than one circumferential turn.

[0084] In this installed state, the end in the circumferential direction at which the pair of opening elements 82, 82 abut each other is turned into one (right side in Fig. 6) the groove-like parts 28 are fitted in the intermediate sleeve 24. The pair of opening elements 82, 82 at the other end in the circumferential direction are both fitted into the end of the other groove-like part 28 (left side in Fig. 6) of the intermediate sleeve 24 in the circumferential direction. In the other groove-like part 28 of the intermediate sleeve 24, a separator rubber 84 is formed so as to protrude circumferentially over the entire length in the groove width direction at the intermediate portion. Furthermore, by positioning the other ends of the pair of opening members 82, 82 in the circumferential direction on the two sides sandwiching the separator rubber 84 in the circumferential direction, respectively, the respective ends of the pair of opening members 82, 82 in the circumferential direction are maintained in a state of abutting against each other.

[0085] As in Fig. 8, in each opening member 82, wide protrusion parts 86, 86 protruding in the width dimension (the dimension in the axial direction) are provided in the intermediate portion in the circumferential direction, and the intermediate portion in the circumferential direction is larger than the side portions in the circumferential direction.

[0086] Furthermore, in each opening member 82, a through hole 88 extending circumferentially from the circumferentially abutting ends to the vicinity of the other end is formed so as to penetrate the inner and outer surfaces. Furthermore, on the other end side of the opening member 82 in the circumferential direction, a through hole 90 having a substantially rectangular shape and a large width is formed to penetrate the inner and outer surfaces, and one end of the through hole 88 is open to the through hole 90. Furthermore, a bottom member 92 made of a non-magnetic material such as an elastic rubber body or synthetic resin is attached to the opening part of the through hole 88 on the inner peripheral side to seal the opening part in a liquid-tight manner. Accordingly, the through hole 88 is configured in a substantially concave groove configuration.

[0087] In the first embodiment, instead of the magnetic flux concentrating elements 42, 42 in the first embodiment, such pairs of orifice elements 82, 82 are inserted and installed into the groove-like parts 28, 28 of the intermediate sleeve 24. Accordingly, the through holes 88, 88 of the pair of orifice elements 82, 82 are connected in series in the circumferential direction, and an orifice path 81 is formed, which extends along the inner peripheral surface of the outer cylindrical member 16 in the circumferential direction by a length equal to or greater than half the circumference. The two ends of the orifice path 81 in the circumferential direction are respectively communicated with the respective fluid chambers 38 via the through holes 90 formed in the respective orifice elements 82.

[0088] In such a motor mount 80 of the embodiment, by separating the single-component opening member 82 at both sides in the axial direction (the opening width direction) using the through hole 88 in the portion where the opening path 81 is formed, a pair of magnetic flux concentrating members 94, 94 are formed, spaced apart from each other by a predetermined distance and located at opposite positions in the axial direction. Moreover, the opening path 81 is formed between the opposite surfaces of the pair of magnetic flux concentrating members 94, 94 made of a ferromagnetic material.

[0089] Accordingly, in the engine mount 80 of the embodiment, as in the engine mount of the first embodiment, it is possible to efficiently control the rheological properties of the magnetic functional fluid 39 using the magnetism from the magnetic field generating unit 56, and the switching control of the vibration damping properties can be realized with favorable energy efficiency based on the fluid flow behavior through the orifice path 81.

[0090] In particular, since the opening path 81 is realized with a longer path length than the opening path 40 of the first embodiment in the embodiment, the tuning degree of freedom of the opening path 81 can be facilitated, and the vibration damping characteristics can be further changed by applying the magnetic field generated by the magnetic field generating unit 56 in the ring shape to the magnetic functional fluid 39 in the opening path 81 over a wide range in the circumferential direction.

[0091] Furthermore, in the embodiment, in the wide protrusion parts 86, 86 formed in the opening member 82, since the pair of magnetic flux concentrating members 94, 94 overlap with the respective opening ends of the yoke part 60 on the inner peripheral side in the projection of the radial direction, the magnetic flux loss on the magnetic path can be suppressed, and it is possible to apply the magnetic field from the yoke part 60 to the magnetic functional fluid 39 in the opening path 81 more efficiently.

[0092] In the opening member 82 of the embodiment, the pair of magnetic flux concentrating members 94, 94 separated by the through-hole 88 are formed in an integral and continuous one-component configuration at the outer peripheral edge of the through-hole 90 provided at one end in the circumferential direction. However, the pair of magnetic flux concentrating members 94, 94 may also be configured, for example, as separate components that are independent of each other and connected by the bottom member 92. In this case, it is not necessary to provide the through-hole 90, and the decrease in the magnetic force acting on the magnetic functional fluid 39 within the opening path 81 due to the magnetic flux being wrapped around the continuous portion at the outer peripheral edge of the through-hole 90 can be avoided.

[0093] Moreover, the shapes of the magnetic force surfaces acting on the magnetic functional fluid in the opening path, that is, the opposing surfaces of the pair of magnetic flux concentrating elements 42, 42 in the first embodiment or the opposing surfaces of the pair of magnetic flux concentrating elements 94, 94 in the second embodiment, are not limited to being parallel and opposing flat surfaces as in the embodiment.

[0094] For example, as in a motor mount 100 as a third embodiment in Fig. 9 to 10, it is possible to incorporate opposing surfaces that are not parallel to each other into the pair of magnetic flux concentrating elements 94, 94. In the motor mount 100 of the embodiment, components and elements in the same configuration as those of the second embodiment are designated by the same reference symbols as the second embodiment in the drawings, and the detailed description thereof will be omitted.

[0095] That is, although an opening member 102 in the motor mount 100 of the embodiment has substantially the same configuration as the opening member 82 of the second embodiment, opposing surfaces 104, 104 of the pair of magnetic flux concentrating members 94, 94 formed by two side wall surfaces of the opening path 81 are opposing surfaces that are not parallel to each other, and the path cross section of the opening path 81 is configured in a shape other than the rectangular shape.

[0096] Specifically, in this embodiment, the opposing surfaces 104, 104 of the pair of magnetic flux concentrating elements 94, 94 constituting the side wall surfaces of the opening path 81 are arranged as separate surfaces and gradually slope from the inner peripheral side to the outer peripheral side. As a result, the shape of the path cross section of the opening path 81 is substantially table-shaped.

[0097] When the opposing distance between the opposing surfaces 104, 104 of the pair of magnetic flux concentrating elements 94, 94 increases from the inner peripheral side to the outer peripheral side, as is the case in the embodiment, the magnetic flux applied between the pair of opposing surfaces 104, 104 is guided to the inner peripheral side rather than the outer peripheral side in the opening path 81, and a stronger magnetic field can be applied to the magnetic functional fluid flowing on the inner peripheral side than the magnetic functional fluid flowing on the outer peripheral side in an opening path 112.

[0098] In this way, for example, it is possible to control the flow state of the magnetic functional fluid in the orifice path 112 by varying the magnitude of the magnetic field applied to the magnetic functional fluid in the orifice path 112 in the radial direction. In particular, when the rheological degree of the magnetic functional fluid is smaller in the outer peripheral region of the orifice path 112, where the flow path of the magnetic functional fluid is longer, than in the inner peripheral region, an effect such as suppressing the occurrence of turbulence due to different flow paths in the orifice path 112 can also be expected.

[0099] In particular, the shape of the path cross-section of the opening path 81 is not limited to being specified in the form of a table as in the embodiment. For example, only one of the wall surfaces may be inclined in the opposite direction, and the opposite surface 104 in the opening path 81 may also have any shape, such as a curved surface.

[0100] Furthermore, in the first to third embodiments, an opening path 40, 81, 112 extending linearly in the circumferential direction is formed in the groove-like parts 28 of the intermediate sleeve 24. However, a specific type or configuration, including the length or cross-sectional area of ​​the opening path, is not limited thereto. Moreover, as mentioned above, the magnetic flux concentrating element disposed in the opening path is not necessarily required in the disclosure. However, the specific mode, including the shape or size of the magnetic flux concentrating element, adopted is not particularly limited.

[0101] For example, as in a motor mount 110 as a fourth embodiment in Fig. 11, it is possible to form two opening paths 112, 112 formed in the groove-like part 28 of the intermediate sleeve 24 and extending in the circumferential direction substantially parallel to the opening groove 41. The motor mount 110 of the embodiment shows a mode different from the first embodiment in the opening configuration, but the basic configuration is the same as that of the first embodiment. Therefore, only a part of a longitudinal section demonstrating the characteristics is shown, and in such an illustration, components and parts configured substantially the same as those of the first embodiment are designated by the same reference symbols, and a detailed description is omitted.

[0102] That is, in the motor mount 110 of the embodiment, the magnetic flux concentrating member 114, as an opening member constituting the opening path 112, is configured in a curved plate shape extending in an arcuate manner in the circumferential direction with a substantially constant cross-sectional shape (a substantially rectangular shape in the embodiment). Compared with the opening groove 41 formed in the groove-like part 28 of the intermediate sleeve 24, such a magnetic flux concentrating member 114 is configured with a substantially equal length dimension in the circumferential direction and is arranged over the entire length of the opening groove 41.Furthermore, the width dimension (mounting dimension in the axial direction) of such a magnetic flux concentrating element 114 is smaller than the groove width (groove inner dimension) of the opening groove 41, and the magnetic flux concentrating element 114 is arranged in the center of the opening groove 41 in the width direction. The thickness dimension (dimension in the radial direction) of the magnetic flux concentrating element 114 is equal to or slightly larger than the opening groove 41.

[0103] Accordingly, the opening groove 41 is divided by the magnetic flux concentrating member 114 in the groove width direction, and the pair of opening paths 112 located on the both sides of the magnetic flux concentrating member 114 in the width direction and extending in the circumferential direction are formed.

[0104] In the pair of opening paths 112, 112, only the wall surface on the inside in the axial direction of the bracket between the two side wall surfaces opposite each other in the axial direction of the bracket is formed by the magnetic flux concentrating element 114. The wall surface on the outside in the axial direction of the bracket is formed by the rubber-elastic main body 18 in the groove-like part 28.

[0105] Even if only one wall surface in the path width direction of the opening path 112 is configured with a magnetic flux concentrating element 114 in this way, the magnetic flux is concentrated by the magnetic flux concentrating element 114 forming the magnetic path of the magnetic field generated by the magnetic field generating unit 56, so that the end surfaces of the magnetic flux concentrating element 114 exposed to the opening paths 112, 112 form magnetic pole surfaces 116, 116. Therefore, the magnetic force can be efficiently applied to the magnetic functional fluid 39 in each of the opening paths 112, 112, and the same effect as in the above embodiments can be exhibited.

[0106] Specifically, in the embodiment, the intermediate sleeve 24 made of a ferromagnetic material is disposed on the outer side in the axial direction of the bracket with respect to the opening paths 112, and the magnetic flux concentrating member 114 is disposed on the inner side in the axial direction of the bracket. Therefore, the magnetic flux concentrating effect due to the intermediate sleeve 24 also acts on the magnetic functional fluid 39 in the opening path 112, and synergistic magnetic flux concentration with respect to the magnetic functional fluid 39 in the opening paths 112 provided between the intermediate sleeve 24 and the magnetic flux concentrating member 114 can be expected between the intermediate sleeve 24 and the magnetic flux concentrating member 114.

[0107] Also, in the motor mount 110 of the embodiment, by adopting magnetic flux concentrating elements (42, 42) located at two end portions in the axial direction of the mount as shown in the first embodiment, together with the magnetic flux concentrating element 114 located at the middle portion in the axial direction of the mount in the opening groove 41, both of the respective opposite inner surfaces of the two opening paths 112, 112 can also be formed by magnetic flux concentrating elements.

[0108] Although all of the first to fourth embodiments manufacture the intermediate sleeve 24 from a single member by press forming, etc., it is also possible to manufacture such an intermediate sleeve 24 in a split structure using two or more members. By using the intermediate sleeve 24 in a split structure, it is possible to utilize advantages in manufacturing or assembly. For example, by splitting the intermediate sleeve at a position corresponding to the portion where the opening path is formed and arranging the split structures separately in the axial direction of the bracket, the decrease in the magnetic flux acting on the opening path due to the wrapping of the magnetic flux passing through the intermediate sleeve can be suppressed.

[0109] As in (a) to (c) of Fig. For example, as shown in Figure 12, it is possible to form the intermediate sleeve 24 with a pair of split sleeves 24a, 24a that are split centrally in the axial direction along a circumferentially extending parting line. In the drawing of another embodiment of the intermediate sleeve 24 shown below, the same reference symbols as in the above embodiments are used to indicate the same parts as in the above embodiments for clarity.

[0110] In each split sleeve 24a, only substantially one half of the groove-like part 28 in the axial direction is formed integrally with the side portions 29 in the axial direction in a cylindrical shape with a large diameter. Furthermore, the two split sleeves 24a, 24a are spaced apart from each other by a predetermined distance in the axial direction, and the end surfaces of the groove-like parts 28, 28 are arranged on the outer peripheral surface of the rubber-elastic main body in a state in which they oppose each other in the axial direction.

[0111] Also, in such split sleeves 24a, 24a, the magnetic field acting opening part 32 may be formed to extend across the respective bottom wall portions 30a, 30a, as in the above embodiments. However, in this embodiment, taking into account the strength and dimensional accuracy of the split sleeves 24a, 24a and processing factors, independent magnetic field acting opening parts 32a, 32a are provided in a state where they pass through the substantial centers of the respective bottom wall portions 30a, 30a.

[0112] Even if the pair of split sleeves 24a, 24a divided in the axial direction in this manner are adopted as the intermediate sleeve 24 of the above embodiments, the same effects as those of the above embodiments can be exerted. Specifically, in the split sleeves 24a, 24a of this embodiment, the side portions in the axial direction are arranged to be separated from each other. Therefore, compared with the case where the split sleeves 24a, 24a are adopted in an integral configuration, the leakage (entanglement) of the magnetic flux through the split sleeves 24a, 24a to the outside of the opening path can be suppressed, and the concentration of the magnetic flux on the magnetic functional fluid in the opening path can be further facilitated.

[0113] In addition, it is also possible to use a pair of split sleeves 24b, 24b as shown in (a) to (c) of Fig. 13, and to set a larger distance between the pair of split sleeves 24b, 24b in the axial direction at portions corresponding to the opening path.

[0114] In the opening member 24 of the embodiment, it is also possible to adopt a configuration in which, in the bottom wall portion 30 of the groove-like part 28 in the opening member 24 of the first embodiment, the opening part 32 acting on the magnetic field has a predetermined dimension in the groove width direction (fixing axis direction) of the groove-like part 28 and is formed in a length over the entire length of the groove-like part 28 in the circumferential direction (groove length direction).

[0115] By using such split sleeves 24b, 24b, it is possible to set a separation distance between the split sleeves 24b, 24b which is larger than that of the split sleeves 24a, 24a shown in (a) to (c) of Fig. 12, and it is possible to more effectively suppress the leakage (entanglement) of the magnetic flux through the split sleeves 24a, 24a to the outside of the opening path. In addition, compared to the arrangement shown in (a) to (c) of Fig. 12, the components are smaller, materials are saved, and manufacturing is also simple because it is not necessary to form the opening part 32a acting on the magnetic field in each split sleeve 24a.

[0116] In addition, as in (a) to (c) of Fig. 14, for example, it is possible to form the intermediate sleeve 24 as a pair of split sleeves 24c, 24c each configured in a semi-cylindrical shape such that opposite portions in a radial direction are each divided by a parting line extending in the axial direction. The intermediate sleeve 24 of the embodiment is configured as the pair of split sleeves 24c, 24c, the side portions in the radial direction are orthogonal to the opposite direction of the groove-like parts 28, 28 and are each divided by a parting line extending in the axial direction. Although the intermediate sleeve in modes (a) to (c) of Fig. 14 is divided into two parts in the circumferential direction, a split configuration is also possible in which the intermediate sleeve is divided into three parts in the circumferential direction.

[0117] Although the embodiments of the disclosure have been described in detail above, the disclosure is not limited to this detailed description. For example, multiple opening paths may be arranged. In this case, it is sufficient for the magnetic field to be applied by the magnetic field generation unit to the magnetic functional fluid in at least one of the opening paths.

[0118] In the embodiment, the entire opening path 40 extends in the circumferential direction. However, the opening path may also extend partially in the axial or radial direction, for example. In this case, the magnetic field of the magnetic field generating unit can be applied to the magnetic functional fluid in the circumferentially extending part of the opening path.

[0119] In this embodiment, the coil 58 is arranged over the entire circumference so that it is inserted into the outer cylindrical member 16 from the outside. However, the coil 58 is not required to be arranged coaxially with the outer cylindrical part 16. Specifically, for example, the coil may also be arranged partially to the outer peripheral side of the outer cylindrical member in the circumferential direction so that the center axis of the coil is located on an outer peripheral side with respect to the outer cylindrical member. Accordingly, at the time the coil is energized, the position at which the magnetic field acts on the magnetic functional fluid can be limited in the circumferential direction of the outer cylindrical member.

[0120] In the above embodiments, the two fluid chambers 38, 38 are configured to serve as pressure-receiving chambers in which an internal pressure changes when vibration occurs. However, one of the fluid chambers may also be configured, for example, to serve as a compensation chamber in which a part of a wall portion is formed by a flexible film. Furthermore, the number of fluid chambers is not limited to two, and a configuration with three or more fluid chambers may also be adopted. Explanation of reference symbols 10 Engine mount (anti-vibration device) (first embodiment) 12 bearing bodies 14 inner shaft part 16 outer cylindrical element 18 rubber-elastic main body 20 stop element 22 projection part 24 Intermediate sleeve (cylindrical intermediate element) 26 Window part 28 groove-like part 29 Side section in axial direction 30 floor wall section 32 opening part acting on the magnetic field 34 pocket-like part 36 Sealing rubber layer 38 Fluid chamber 39 magnetic functional fluid 40 Opening path 41 opening groove 42 Magnetic flux concentration element 44 Positioning projection 46 cylindrical cover element 52, 54 elastic support body 56 Magnetic field generation unit 58 coil 60 yoke part 62 coil bodies 64 connectors 66 connecting part 68 drive unit 70 vehicle body 72 mounting hole 80 Engine mount (anti-vibration device) (second embodiment) 81 Opening path 82 Opening element 84 Separating rubber 86 wide projection part 88 through hole 90 through hole 92 floor element 94 Magnetic flux concentration element 100 Engine mount (anti-vibration device) (third embodiment) 102 Opening element 104 opposite area 110 Engine mount (anti-vibration device) (fourth embodiment) 112 Opening path 114 Magnetic flux concentration element 116 magnetic pole face

Claims

[1] Anti-vibration device (10, 80, 100, 110) which is a fluid-filled anti-vibration device and comprises: a rubber-elastic main body (18); an inner shaft part (14); a cylindrical intermediate element (24), wherein the inner shaft part (14) and the cylindrical intermediate element (24) are connected by the rubber-elastic main body (18); an outer cylindrical member (16) inserted from the outside into and fixed to the cylindrical intermediate member (24); a plurality of fluid chambers (38) separated in a circumferential direction and formed by covering pocket-like parts (34) provided on the rubber-elastic main body (18) and opening to an outer peripheral side of the intermediate cylindrical member (24) using the outer cylindrical member (16); and an opening path (40) through which the fluid chambers (38) can communicate with each other, wherein a magnetic functional fluid is filled into the fluid chambers (38), a magnetic field generating unit (56) which applies a magnetic field to the magnetic functional fluid flowing through the opening path (40) is provided outside the fluid chambers (38), the outer cylindrical element (16) is made of a non-magnetic material, the cylindrical intermediate element (24) consists of a ferromagnetic material and in the cylindrical intermediate element (24) an opening part (32) acting on the magnetic field is provided at a position corresponding to the opening path (40) in which the magnetic field is applied to the magnetic functional fluid. [2] Anti-vibration device (10, 80, 100, 110) according to claim 1, wherein the cylindrical intermediate element (24) comprises: a pair of side portions (29) in an axial direction having a cylindrical shape with a large diameter which is continuous in the circumferential direction; and an intermediate portion (24) in the axial direction, which is partially provided in the circumferential direction and has a concave groove shape extending in the circumferential direction between the pair of side portions (29) in the axial direction, wherein the opening part (32) acting on the magnetic field is provided at the intermediate portion in the axial direction. [3] The anti-vibration device (10, 80, 100, 110) according to claim 2, wherein the cylindrical intermediate member (24) is a single member formed by the pair of side portions (29) in the axial direction connected at the intermediate portion (24) in the axial direction, and the opening part (32) acting on the magnetic field is configured by a window part (26) formed to penetrate through a groove bottom part (30) in the intermediate portion (24) in the axial direction configured in the concave groove shape. [4] The anti-vibration device (10, 80, 100, 110) according to claim 2, wherein the cylindrical intermediate member (24) is configured in a split configuration at two sides in the axial direction in the intermediate portion (24) in the axial direction, and the pair of side portions (29) in the axial direction are separate components, and the opening part (32) acting on the magnetic field is arranged between axially separated parts of the intermediate portion (24) in the axial direction. [5] The anti-vibration device (10, 80, 100, 110) according to claim 1 or 2, wherein the magnetic field generating unit (56) is arranged on an outer peripheral side of the outer cylindrical member (16). [6] The anti-vibration device (10, 80, 100, 110) according to claim 1 or 2, wherein, in the opening path (40), magnetic flux concentrating elements (42) formed of a ferromagnetic material are arranged to oppose each other in a width direction of the opening path (40), and the opening part (32) acting on the magnetic field is provided in the cylindrical intermediate member (24) at a position corresponding to a portion between opposing parts in the magnetic flux concentrating elements (42). [7] Anti-vibration device (10, 80, 100, 110) according to claim 6, wherein an opening element (82) for forming the opening path (40) is arranged between the cylindrical intermediate element (24) and the outer cylindrical element (16) so as to extend in the circumferential direction along the pocket-like part (34) provided in the rubber-elastic main body (18), the opening element (82) is formed from a ferromagnetic material, and the magnetic flux concentrating elements (42) arranged to oppose each other in the width direction of the opening path (40) are formed by the opening element. [8] Anti-vibration device (10, 80, 100, 110) according to claim 1 or 2, wherein the magnetic field generating unit (56) comprises: a coil element that generates a magnetic field by supplying it with current, and a yoke member (60) that directs a magnetic flux in the magnetic field generated by the coil element to the opening path (40).

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