JP2001082532A - Liquid-sealed type active mount - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively and stably provide an active vibration control effect being an object even under a mounting state under which an initial load is exerted, in a liquid-sealed type active mount having an actuator consisting of an electromagnetic exciter to effect axial relative drive of an exciting member on a yoke member while giving the exciting member magnetic force generated at the yoke member through current-carrying in a coil. SOLUTION: In an electromagnetic exciter 14 used in this liquid-sealed type active mount 10, the magnetic pole part 66 of a yoke member 58 to form a magnetic passage through electric connection to a coil 64 and the magnetic force operating part 100 of an exciting member 74 positioned opposite to the magnetic pole part are positioned opposite to each other in a state to be axially inclined through relative displacement of the two members from each other in a direction orthogonal to an axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid-filled active mount having a novel structure, which is used for an engine mount for an automobile and exhibits an active vibration damping effect against vibration to be damped. is there.

[0002]

2. Description of the Related Art As a kind of a vibration isolating device as a vibration isolating connection member or a vibration isolating support member interposed between members constituting a vibration transmission system, a first attachment attached to members that are vibration isolatingly connected to each other. The member and the second mounting member are spaced apart from each other and connected by the main rubber elastic body, while providing a vibration generating means for generating a vibration between the first mounting member and the second mounting member. Active mounts with adjustable vibration isolation are known. For example, a vibration isolator described in Japanese Patent Application Laid-Open No. Sho 61-2939 is such a device. Such an active mount suppresses the vibration by canceling the vibration by applying an exciting force corresponding to the vibration to be damped to the member to be vibration-isolated, or a spring of the mount. By actively changing the characteristics according to the input vibration and lowering the dynamic spring, etc., it is possible to improve the vibration isolation performance.
For example, application to an engine mount or a body mount for an automobile has been considered.

Incidentally, such an active mount requires a vibrator for generating a vibrating force, and such a vibrator requires excellent frequency controllability of the generated vibrating force. Therefore, as a vibrator for active mounting,
For example, as described in the above-mentioned publications, a permanent magnet and a coil are arranged facing each other with a distance therebetween, and a current is applied to the coil to obtain an exciting force using Lorentz force or electromagnetic force. It has been proposed to employ a voice coil type vibrator.

However, in a voice coil type vibrator, the obtained vibrating force is small, and if a sufficient vibrating force is to be obtained, problems such as power consumption, heat generation, and increase in size of the vibrator become problems. There was a problem that it was easy. In addition, in the voice coil type vibrator, the coil side and the permanent magnet side are liable to slide upon relative displacement in the axial direction, and the generation of abnormal noise, energy loss, deterioration of parts, and the like at the sliding contact portion are likely to be problems. There were also problems.

On the other hand, Japanese Patent Application Laid-Open No. 10-227329 proposes a vibrator for an active mount that employs an electromagnet type electromagnetic vibrator. Such a vibrator is generally provided with an annular groove that opens to one side in the axial direction with respect to a yoke member made of a magnetic material, and accommodates and arranges a coil in the annular groove. A magnetic path is formed around the coil, and both magnetic poles of the magnetic path are set on the inner peripheral side wall and the outer peripheral side wall of the opening of the annular groove in the yoke member. A vibrating member, which is spaced apart from the opening side of the annular groove in the yoke member and is opposed in the axial direction, and a magnetic force is exerted on the vibrating member by energizing the coil, whereby the vibrating member And a yoke member to apply an axial exciting force.

In such an electromagnetic vibrator, the frequency and phase of the generated vibrating force can be controlled with high accuracy by controlling the energization of the coil. It is possible to easily obtain a larger exciting force than a voice coil type exciter like this.

However, in a conventional electromagnetic vibrator, the magnetic pole surface of the yoke member and the vibrating member are directly opposed to each other in the displacement direction (axial direction) of the vibrating member. There is a feature that the distance has a very large effect on the magnitude of the generated excitation force. Therefore, if the relative initial positions of the vibrating member and the yoke member are slightly different, the desired magnitude of the vibrating force and, consequently, the active vibration damping effect cannot be effectively obtained, and the stable vibration damping performance is obtained. There was a problem that it was difficult to obtain.

In particular, when a supporting load such as the weight of a power unit is applied in a mounted state, such as in an engine mount for an automobile, the magnetic pole surface of the yoke member and the vibrating member may be affected by the magnitude of the supporting load. Since the distance between the opposing surfaces may change, even if the dimensional accuracy of the vibrator itself is improved, the magnetic pole surface of the yoke member and the vibrating It is extremely difficult to set the distance between the opposing surfaces with high accuracy, and there is a problem that it is more difficult to stably obtain the desired vibration isolation performance.

[0009]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an object even in a mounted state where an initial load or the like is applied. It is an object of the present invention to provide a fluid-filled active mount having a novel structure that can effectively and stably exhibit an active vibration isolation effect.

[0010]

An embodiment of the present invention which has been made to solve such a problem will be described below. In addition, each aspect described below can be adopted in any combination. Further, aspects or technical features of the present invention are described in the entire specification and the drawings without being limited to those described below.
Alternatively, it should be understood that the present invention is recognized based on the inventive concept that can be grasped by those skilled in the art from the description thereof.

According to a first aspect of the present invention, a first mounting member and a second mounting member which are respectively mounted on members to be vibration-isolated are connected by a main rubber elastic body, and a wall is formed by the main rubber elastic body. A part of the fluid chamber is formed to form a fluid chamber in which the incompressible fluid is sealed, and another part of the wall of the fluid chamber is composed of a movable wall that can be displaced, and the movable wall is added. In a fluid-filled active mount provided with a vibrating actuator, a yoke member made of a magnetic material is provided with an annular groove that opens on one side in the axial direction, and a coil is housed and arranged in the annular groove. A magnetic path is formed around the coil by energizing the coil, and both magnetic poles of the magnetic path are respectively formed on the inner peripheral side wall and the outer peripheral side wall of the opening of the annular groove in the yoke member. While the magnetic material The vibrating member is spaced apart from the opening of the annular groove in the yoke member so as to be opposed in the axial direction, and a magnetic force is exerted on the vibrating member by energizing the coil, so that the vibrating member and the yoke The yoke member is fixedly supported by the second mounting member using an electromagnetic vibrator that exerts an axial vibration force between the members, and the vibrating member is fixed to the movable wall. To form an actuator that exerts an exciting force on the movable wall, and further includes an inner peripheral side wall and an outer peripheral side wall of the opening of the annular groove in which the magnetic pole of the yoke member is set in the actuator. And at least one of the vibrating member and the inner and / or outer peripheral portion of the vibrating member positioned closest to the yoke member are directly opposed to each other in the axial direction. At least the other corner of the inner peripheral wall and the outer peripheral wall, and the corner of the inner peripheral part and / or the outer peripheral part of the vibrating member positioned closest thereto in the direction perpendicular to the axis. It is characterized in that it is inclined in the axial direction and is opposed to each other.

In the fluid-filled active mount having the structure according to this aspect, the electromagnetic vibrator having the above-described structure is employed as an actuator that applies a vibrating force to the movable wall. When the coil is energized, a magnetic field is formed between the magnetic pole portions of the yoke member, and a magnetic attractive force or the like is applied to the vibrating member arranged in the magnetic field, whereby the vibrating force is applied to the movable wall. Will be affected.
Therefore, by controlling the current supplied to the coil, the vibration member can be vibrated at the target frequency.

In this case, at least one magnetic pole portion of the yoke member is directly opposed to the vibrating member in the displacement direction (axial direction) of the vibrating member, but at least the other magnetic pole portion of the yoke member. Is opposed to the vibration member in a direction inclined with respect to the displacement direction (axial direction) of the vibration member. In addition, a large magnetic attraction force or the like can be secured between the vibrating member and at least one magnetic pole portion of the yoke member directly opposed in the axial direction. On the other hand, between the vibrating member and at least the other magnetic pole part of the yoke member, which is positioned opposite to the axially inclined yoke member, the direction of the applied magnetic attraction force is also inclined in the axial direction, The amount of change in the magnitude of the magnetic attraction force acting on the yoke member relative to the amount of change in the axial position of the vibration member relative to the yoke member can be reduced.

Therefore, in the fluid-filled active mount having the structure according to this aspect, the variation in the excitation force generated due to the variation in the relative position between the excitation member and the yoke member is suppressed and the stability is improved. The relative position between the vibrating member and the yoke member changes due to, for example, a static initial load applied in the mounted state, due to the adoption of an electromagnetic vibrator with a specific structure that can generate the generated vibrating force. Even in such a case, a stable excitation force can be applied to the movable wall, so that the intended active vibration damping effect can be effectively and stably obtained.

According to a second aspect of the present invention, in a fluid-filled active mount having a structure according to the first aspect, the fluid chamber is defined by a partition wall supported by the second mounting member. By partitioning, a part of the wall part forms a main liquid chamber composed of the main rubber elastic body, and a part of the wall part forms a sub liquid chamber composed of the movable wall. It is characterized in that an orifice passage communicating with the sub liquid chamber is formed. In this aspect, by utilizing the flow action such as the resonance action of the fluid flowing through the orifice passage, the pressure change generated in the main liquid chamber based on the vibration of the movable wall can be more efficiently performed. Therefore, it is possible to obtain a better vibration damping effect.

According to a third aspect of the present invention, in the fluid-filled active mount having the structure according to the first or second aspect, the vibrating member of the actuator is displaced toward the yoke member. By virtue of this, the axial end surfaces of the vibrating member and the yoke member, which are shifted in the direction perpendicular to the axis and inclined in the axial direction and are opposed to each other, do not contact each other, and That we can reach the overlapping position with
Features. By setting the relative position between the vibrating member and the yoke member according to the present aspect, it is possible to more efficiently obtain a large vibrating force and to cause a variation in the relative distance between the vibrating member and the yoke member. It is possible to obtain a more stable excitation force by suppressing variations in the generated excitation force.

According to a fourth aspect of the present invention, there is provided a fluid-filled active mount having a structure according to any one of the first to third aspects, wherein the vibrating member and the yoke member of the actuator are provided. The inner and outer peripheral surfaces which are mutually shifted in the direction perpendicular to the axis and inclined in the axial direction and are opposed to each other are mutually adjacent cylindrical surfaces extending in the axial direction, and the inner and outer peripheral surfaces are projected in the axial direction. It is characterized in that each radial dimension of the inner peripheral surface and the outer peripheral surface is set so that a gap is formed therebetween. According to this aspect, the magnetic attraction force between the vibrating member and the yoke member, which are displaced in the direction perpendicular to the axis and inclined in the axial direction to be opposed to each other, is applied to the vibrating member formed in the cylindrical shape. With the inner and outer peripheral surfaces of the member and the yoke member, it is possible to obtain more efficiently and stably.

According to a fifth aspect of the present invention, there is provided a fluid-filled active mount having a structure according to any one of the first to fourth aspects, wherein the vibrating member and the yoke member of the actuator are provided. In the above, the magnitude of the distance between the opposing surfaces of the parts which are shifted in the direction perpendicular to the axis and inclined in the axial direction to face each other is equal to or less than the magnitude of the distance between the opposing faces of the parts which face each other directly in the axial direction. And that
Features. In such an embodiment, the variation in the generated excitation force due to the variation in the relative distance between the excitation member and the yoke member can be further advantageously reduced. In particular, when the fourth aspect is also employed in this aspect, the inner peripheral surface and the outer peripheral surface each having a cylindrical surface are formed over the entire range of relative movement of the vibration member with respect to the yoke member. The configuration in which the difference in the radial dimension of the vibration member and the yoke member is set to be smaller than the distance between the opposing surfaces of the portions directly opposed to each other in the axial direction in the vibration member and the yoke member can be more suitably adopted.

A sixth aspect of the present invention is directed to a fluid-filled active mount having a structure according to any one of the first to fifth aspects, wherein an inner peripheral side wall portion of the yoke member of the actuator is provided. The vibrating member is axially protruded from the outer peripheral side wall portion, and a concave portion is provided at a central portion of the axially opposing surface of the vibrating member with respect to the yoke member. The vibrating member is positioned so as to directly face the outer peripheral side wall of the member in the axial direction, and the opening corner of the recess of the vibration member is inclined in the axial direction with respect to the outer peripheral corner of the inner peripheral side wall of the yoke member. Further, the bottom surface of the concave portion of the vibrating member is located at the opening corner of the vibrating member and the outer peripheral corner of the inner peripheral side wall of the yoke member with respect to the inner peripheral side wall of the yoke member. Greater than the distance between the opposing surfaces. That directly opposition position in the axial direction, characterized. According to this aspect, the portion between the yoke member and the vibrating member which is directly opposed in the axial direction and in which a magnetic attraction force or the like is applied, and which is opposed to the portion inclined in the axial direction and magnetically acts. The portion where the suction force or the like is applied can be advantageously formed together.

According to a seventh aspect of the present invention, there is provided a fluid-filled active mount having a structure according to the first to sixth aspects, wherein a part of the wall is formed of a flexible film which is easily displaced. It is characterized in that an equilibrium chamber that is configured to allow a change in volume is formed, and that a fluid flow path that communicates the equilibrium chamber with the fluid chamber is formed. In this embodiment,
Even in the case where the main rubber elastic body is elastically deformed by the initial load being applied in the mounted state, the internal pressure of the fluid chamber is released to the equilibrium chamber through the fluid flow path, so that the change in the internal pressure of the fluid chamber is reduced or avoided. As a result, it is possible to more stably obtain the intended anti-vibration effect. In addition,
In particular, when the second aspect is also employed in this aspect, it is desirable to tune the fluid flow path to a lower frequency range than the orifice path, whereby the flow action of the fluid that is caused to flow through the orifice path is achieved. The effect of improving the active vibration isolating action based on the above can be stably exhibited almost without being affected by the fluid flow path.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an engine mount 10 for an automobile according to an embodiment of the present invention. The engine mount 10 has a structure in which a first mounting member 12 as a first mounting member and a second mounting member 14 as a second mounting member are connected by a rubber elastic body 16. The first mounting member 12 is mounted on the power unit of the vehicle, and the second mounting member 14 is mounted on the body of the vehicle, so that the power unit is supported on the body by vibration isolation. In the following description, the vertical direction refers to the vertical direction in the figure in principle.

More specifically, the first mounting member 12 has a substantially inverted truncated conical block shape, and a screwing portion 13 protruding axially upward from the large-diameter end surface. The first mounting bracket 12 is fixedly attached to a power unit (not shown) of a vehicle by a screw hole provided in the screwing portion 13. A flange-shaped stopper portion 2 protruding radially outward is provided on the outer peripheral surface of the large-diameter end portion of the first mounting member 12.
2 are integrally formed.

A rubber elastic body 16 is bonded to the first mounting member 12 by vulcanization. The rubber elastic body 16 has a large-diameter substantially truncated cone shape as a whole, and has a large-diameter concave portion 18 that is open at the large-diameter side end face. The metal fittings 12 are arranged on the same central axis in a state of being inserted in the axial direction, and are vulcanized and bonded. A large-diameter cylindrical metal sleeve 20 is superimposed on the outer peripheral surface of the large-diameter end portion of the main rubber elastic body 16 and is vulcanized and bonded. As a result, the main rubber elastic body 16 is separated from the first mounting bracket 12 and the metal sleeve 20.
And is formed as an integral vulcanized molded product having Also,
The stopper portion 22 of the first mounting member 12 has a cushioning rubber 2
3 is integrally formed with the main rubber elastic body 16 so as to protrude upward in the axial direction.

On the other hand, the second mounting member 14 has a large-diameter substantially stepped cylindrical shape, and the upper portion in the axial direction is a large-diameter portion 26 with a step portion 24 formed at an intermediate portion in the axial direction interposed therebetween. The lower part in the axial direction is a small diameter part 28.
A thin seal rubber layer 30 covering almost the entire surface is provided on the inner peripheral surfaces of the large-diameter portion 26 and the small-diameter portion 28, and is vulcanized and bonded. A diaphragm 32 made of a thin rubber film having a thin disk shape is provided.
Is vulcanized and adhered to the peripheral edge of the opening of the second mounting bracket 14, whereby the lower opening of the second mounting bracket 14 is closed in a fluid-tight manner. In the present embodiment,
The diaphragm 32 is formed integrally with the seal rubber layer 30, and a flexible film is formed by the diaphragm 32.

The large diameter portion 26 of the second metal fitting 14 is externally inserted into the metal sleeve 20 and is fitted and fixed by press-fitting, drawing, or the like, so that the main rubber elastic body 1 is formed.
6 is fixed to the outer peripheral surface. As a result, the first mounting member 12 and the second mounting member 14 are axially separated from each other on the same central axis, and
6 are elastically connected. Further, since the large-diameter portion 26 of the second mounting member 14 is fixed to the main rubber elastic body 16, the upper opening of the second mounting member 14 is closed in a fluid-tight manner by the main rubber elastic body 16. . Further, as shown in the drawing, the second mounting member 14 is covered with a stopper cylindrical metal member 37 from the upper side in the axial direction, and is fitted and fixed to the large-diameter portion 26 of the second mounting member 14. The stopper tube fitting 37 has a small-diameter portion 41 and a large-diameter portion 43 vertically above and below a step portion 39 formed at an intermediate portion in the axial direction, and has a radially inward portion at an upper end portion in the axial direction. A projecting annular plate-shaped contact projection 45 is formed integrally with the first mounting member 12.
And is opposed to the stopper portion 22 in the axially upward direction. When a large vibration load is input, the stopper portion 22 abuts on the abutting projection 45 via the cushioning rubber 23 so that the first mounting member 12 and the second mounting member 14 rebound in the rebound direction (axial direction). (Separation direction)
Is limited.

A partition member 34 is accommodated in the second mounting member 14 at an intermediate position in the axial direction.
It is provided at an intermediate portion between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 32. The partition member 34 is formed of a hard material such as a metal or a synthetic resin, has a substantially disk shape, and is disposed so as to extend in a direction perpendicular to the axis of the second mounting bracket 14. To the stepped portion 2 of the second mounting member 14.
4 is fixed to the second mounting bracket 14 by being held between the metal sleeve 20 and the axial end face of the metal sleeve 20. Thus, the hollow interior of the second mounting member 14 is fluid-tightly partitioned between the main rubber elastic body 16 and the diaphragm 32 with the partition member 34 interposed therebetween. A part of the wall is formed of the main rubber elastic body 16 between the main rubber elastic body 16 and the partition member 34, and a main liquid chamber 35 in which an incompressible fluid is sealed is formed. I have. When vibration is input between the first fitting 12 and the second fitting 14, the main rubber chamber 16
An internal pressure change is generated based on the elastic deformation of the internal pressure. Note that water, an alkylene glycol, a polyalkylene glycol, a silicone oil, or the like can be used as the sealed fluid. In the present embodiment, in particular, a vibration-proof effect based on the resonance action of the fluid is effectively exerted as described later. Thus, a low-viscosity fluid having a viscosity of 0.1 Pa · s or less is suitably used. Also, the filling of such an incompressible fluid,
For example, the main rubber elastic body 1 with respect to the second mounting
It can be advantageously performed by assembling the integrally vulcanized molded product of No. 6 in an incompressible fluid.

An annular block-shaped orifice member 36 made of a hard material such as metal or synthetic resin is provided on the outer peripheral portion of the partition member 34 so as to overlap the lower surface thereof. A flange-shaped annular support piece 38 protruding from the outer peripheral surface of the metal member 20 is sandwiched between the stepped portion 24 of the second mounting member 14 and the axial end surface of the metal sleeve 20 together with the outer peripheral edge of the partition member 34. As a result, the orifice member 36 is fixed to the second mounting member 14.

Further, a movable wall 44 is provided at the lower opening in the axial direction of the orifice member 36. In the movable wall 44, an inverted cup-shaped movable metal member 46 opening downward is provided at a central portion, and an annular fitting metal member 48 extending in the circumferential direction with an L-shaped cross section is provided at an outer peripheral portion. A ring-shaped rubber elastic body 50 having an annular plate shape is interposed between the movable metal fitting 46 and the cylindrical wall of the fitting metal fitting 48, and the inner peripheral surface of the wall rubber elastic body 50 is formed in the cylindrical shape of the movable metal fitting 46. The rubber elastic body 5 is vulcanized and adhered to the wall portion.
0 is vulcanized and bonded to the fitting 48. In short, the wall rubber elastic body 50 includes the movable metal fitting 46 and the fitting metal fitting 4.
8 is formed as an integral vulcanized molded product.

The movable wall 44 is fitted with the fitting 4
8 is press-fitted and fixed to the orifice member 36 to assemble the lower opening of the orifice member 36 in a fluid-tight manner. Thus, in the hollow interior of the orifice member 36, a part of the wall portion is constituted by the movable wall 44 between the facing surface of the partition member 34 and the movable wall 44, and has the same incompressibility as that of the main liquid chamber 35. A sub liquid chamber 52 in which a fluid is sealed is formed. In the sub liquid chamber 52, an internal pressure change is generated based on the displacement of the movable wall 44.

The orifice member 36 is formed with a peripheral groove 40 which is open on the upper surface and extends in the circumferential direction with a length slightly less than one round. The peripheral groove 40 is covered by the partition member 34 so that An orifice passage 42 extending in the circumferential direction is formed. The orifice passage 42 has one end in the circumferential direction connected to the main liquid chamber 35 through a communication hole provided in the partition member 34, and the other end in the circumferential direction connects to the orifice member 36. Fluid flows through the orifice passage 42 based on a relative pressure difference between the main liquid chamber 35 and the sub liquid chamber 52 through a communication hole (not shown) provided. Is to be generated.

In the orifice passage 42, a pressure change generated in the sub liquid chamber 52 by the displacement of the movable wall 44 based on the flow action such as the resonance action of the fluid caused to flow in the inside of the orifice passage 42 is applied to the main liquid chamber 35. On the other hand, the cross-sectional area, the length, and the like are set according to the frequency range in which the active vibration isolation effect is required so that the transmission is more efficiently performed and the excellent active vibration isolation effect is exhibited.

Further, inside the second mounting bracket 14,
In the small diameter portion 28 located below the movable wall 44, an actuator 54 as a vibrator is incorporated in a housed state. In the actuator 54, a driving force generating mechanism such as a yoke member 58, a coil 64, and a vibrating plate 74 is assembled to a thick holder block 56 having a substantially cylindrical shape. Hardware 14
Is fixed in a fluid-tight manner with the seal rubber layer 30 interposed therebetween by press fitting, drawing, or the like, and is supported by the second mounting member 14. The upper end face in the axial direction of the holder block 56 is fluid-tightly overlapped with the lower end face in the axial direction of the orifice member 36 via the fitting 48.

Here, the holder block 56 is desirably formed of a non-magnetic material such as synthetic resin or aluminum. On the other hand, the yoke member 58 is formed of a ferromagnetic material such as iron and has a circular block shape, and is provided with an insertion hole 60 extending through the central axis in the axial direction. Around the hole 60, an annular groove 62 that opens upward in the axial direction is provided. The coil 64 is housed in the annular groove 62 and is fixedly assembled.
A yoke is formed around the coil 64 and the coil 6
The ring-shaped magnetic path is formed by energizing 4.

Since the coil 64 is accommodated in the annular groove 62 formed in the yoke member 58, the yoke formed around the coil 64
4, an outer peripheral wall 68 located on the outer peripheral side of the coil 64, and the axial lower ends of the inner peripheral wall 66 and the outer peripheral wall 68 are interconnected. The upper end of the inner peripheral side wall 66 and the upper end of the outer peripheral side wall 68 are separated from each other in the upper part in the axial direction. The upper end surface in the axial direction of the inner peripheral side wall portion 66 protrudes axially above the upper end surface in the axial direction of the outer peripheral side wall portion 68 by a predetermined height, and is axially higher than the upper end surface in the axial direction of the coil 64. It protrudes upward and protrudes.

In the insertion hole 60 of the yoke member 58,
A connecting rod 72 having a cross-sectional shape sufficiently smaller in diameter than the insertion hole 60 is inserted and arranged, and a vibrating member is provided for the upper end and the lower end of the connection rod 72 protruding from the insertion hole 60 on both the upper and lower sides. Vibrating plate 74 and stabilizing plate 76
Are fixed in such a manner that they spread in the direction perpendicular to the axis. The vibrating plate 74 and the stabilizing plate 76 are connected to each other by a connecting rod 72, so that relative displacement in the axial direction with respect to the yoke member 58 is integrally permitted as a whole. That is, the vibrating plate 74 and the stabilizing plate 76 are axially outwardly separated from each other on both sides in the axial direction of the yoke member 58 and the coil 64, and are opposed to the yoke member 58 and the coil 64 in the axial direction. ing.

The stabilizer 76 has a substantially cup shape that opens upward. Around the stabilizer 76, an annular fixture 78 extending in the circumferential direction with an L-shaped cross section is provided radially outward. Are spaced apart from each other. Furthermore, these stabilizers 7
A supporting rubber elastic body 80 having an annular plate shape is interposed between the cylindrical wall of the fixing member 78 and the fixing bracket 78, and the inner peripheral surface of the supporting rubber elastic body 80 is attached to the cylindrical wall of the stabilizer 76. The support rubber elastic body 80 is vulcanized and bonded to the fixing bracket 78 while being vulcanized and bonded. And the fixing bracket 78 is
The holder block 56 is superimposed fluid-tightly on the lower surface in the axial direction, and is fixed by bolts, welding, or the like.
As a result, the stabilizer plate 76 is supported by the holder block 56 and, consequently, the second mounting member 14 by the support rubber elastic body 80.
And are elastically positioned and supported.

Further, by incorporating such an actuator 54 into the second mounting member 14, the small-diameter portion 28 of the second mounting member 14 has a wall between the opposing surfaces of the stabilizer 76 and the diaphragm 32. A part of the part is constituted by the diaphragm 32, and an equilibrium chamber 82 is formed in which a volume change is easily allowed based on the deformation of the diaphragm 32. The equilibrium chamber 82 is filled with the same incompressible fluid as the main liquid chamber 35 and the sub liquid chamber 52. Also,
The holder block 56 constituting the actuator 54 is provided with an axial groove 84 extending in the axial direction on the outer peripheral surface. The axial groove 84 is covered by the small-diameter portion 28 of the second mounting member 14. A fluid flow path 86 is formed. One end of the fluid flow path 86 is connected to the main liquid chamber 35 via the orifice passage 42 by a through hole 88 provided in the orifice member 36, and the other end of the fluid flow path 86 Is communicated with the equilibrium chamber 82.

In short, a fluid flow is generated between the main liquid chamber 35 and the equilibrium chamber 82 through the fluid flow path 86. And the engine mount 10
When the support load of the power unit is applied and the main rubber elastic body 16 is elastically deformed, the fluid flowing from the main liquid chamber 35 to the equilibrium chamber 82 through the fluid passage 86 causes the pressure in the main liquid chamber 35 to be increased. The increase is reduced or avoided. At the time of vibration input, the main liquid chamber 3
By generating a fluid flow through the fluid flow path 86 based on the relative pressure difference between the pressure chamber 5 and the equilibrium chamber 82, a vibration damping effect based on a fluid action such as a resonance action of the fluid is exerted. It has become. In particular, in the present embodiment, the vibration damping effect based on the flow action of the fluid that is caused to flow through the fluid flow path 86 is exerted in a lower frequency range than the vibration damping effect based on the fluid flow action through the orifice passage 42. In addition, the fluid passage 86 is tuned to a lower frequency range than the orifice passage 42.

On the other hand, in the actuator 54, the vibrating plate 74 fixed to the upper end of the connecting rod 72 is formed of a ferromagnetic material such as iron, and has a substantially thick disk shape as a whole. ing. In the center of the vibrating plate 74, a circular central concave portion 90 that opens downward on the lower surface and a circular central convex portion 92 that protrudes upward on the upper surface are integrally formed. . That is, the vibrating plate 74 has a substantially hat shape as a whole due to the central concave portion 90 and the central convex portion 92. The vibration plate 74
The outer diameter of the outer peripheral side wall 68 of the yoke member 58
Of the central recess 90
The inner diameter of the cylindrical inner peripheral surface 94 is larger by a predetermined amount than the outer diameter of the cylindrical outer peripheral surface 96 of the inner peripheral side wall 66 of the yoke member 58.

The vibrating plate 74 is mounted on the movable wall 44.
, The central convex portion 92 of which is movable
Is press-fitted and fixed to the cylindrical wall portion. As a result, the vibration plate 74 is elastically positioned and supported by the orifice member 36 and the second mounting member 14 via the wall rubber elastic body 50. In short, the vibrating plate 74 and the stabilizing plate 76 integrally connected by the connecting rod 72 are formed at both upper and lower ends in the axial direction via the wall rubber elastic body 50 and the supporting rubber elastic body 80, which expand in the direction perpendicular to the axis. It is elastically supported at a predetermined position by the second mounting member 14, and the wall rubber elastic body 50 and the support rubber elastic body 80
The axial displacement is allowed on the basis of the elastic deformation of.

The vibrating plate 74 thus elastically supported is
The opening side of the magnetic path in the yoke member 58 (the upper side in the axial direction)
The upper end face in the axial direction of the outer peripheral side wall portion 68 of the yoke member 58 is
8 and is directly opposed to the lower surface of the yoke member 58 in the axial direction.
The axial upper end portion 6 is opposed to the opening corner portion 100 of the central concave portion 90 of the excitation plate 74 in a radially inward direction without directly facing the opening corner portion 100 in the axial direction. In particular, in the present embodiment, the lower surface of the outer peripheral portion of the vibration plate 74 is
The neutral position of the vibrating plate 74 (the elasticity when the coil 64 is not energized) so that the vibrating plate 74 can be positioned on substantially the same plane that extends in the direction perpendicular to the axial direction of the axially upper end surface of the inner peripheral side wall portion 66 of the yoke member 58. Support position) is set.

The bottom surface of the central concave portion 90 of the vibrating plate 74 is axially separated from and directly opposed to the axially upper end surface of the inner peripheral side wall portion 66 of the yoke member 58. The distance between the opposing surfaces is the distance between the upper end in the axial direction of the inner peripheral side wall 66 of the yoke member 58 inclined in the axial direction and the opening corner 100 of the central recess 90 of the vibration plate 74. It is set larger than the distance. In particular, in the present embodiment, as schematically shown in FIG. 2, the cylindrical inner peripheral surface 94 of the central concave portion 90 in the vibration plate 74 and the cylindrical outer peripheral surface of the inner peripheral side wall portion 66 in the yoke member 58 A gap having a radial dimension: D is formed over the entire surface between the radially opposed surfaces of the vibrating plate 7 and the vibration plate 7.
4, a distance between opposing surfaces of the bottom surface of the central recess 90 and the upper end surface in the axial direction of the inner peripheral side wall portion 66 of the yoke member 58:
L is set so that D ≦ L. Further, in the present embodiment, in particular, the distance M between the opposing surfaces of the lower surface of the outer peripheral edge 98 of the vibration plate 74 and the upper end surface in the axial direction of the outer peripheral side wall 68 of the yoke member 58 satisfies D ≦ M. Is set to

By setting such a neutral position, the vibrating plate 74 is displaced in the axial direction based on the elastic deformation of the wall rubber elastic body 50 and the supporting rubber elastic body 80, so that the yoke is formed. The yoke member 58 is moved toward and away from the member 58 in the axial direction.
Of the inner peripheral side wall 66 of the inner wall of the vehicle enters without contact.

In the engine mount 10 having the above-described structure, a yoke is formed by the yoke member 58 disposed around the coil 64 by energizing the coil 64, and the inner and outer peripheral wall portions 66, 66 of the yoke member 58 are formed. A magnetic field is applied to the vibrating plate 74 positioned opposite thereto by the two magnetic poles formed at the distal end of the tip 68, so that the vibrating plate 74 is moved toward the yoke member 58, that is, downward in the axial direction in the figure. Is driven by suction. Therefore, by controlling the energizing frequency and current to the coil 64, the vibration plate 74 can be vibrated at the target frequency and amplitude.

The change in pressure generated in the auxiliary liquid chamber 52 in response to the vibration of the vibration plate 74 is transmitted to the orifice passage 4.
By transmitting the internal pressure of the main liquid chamber 35 to the input vibration by transmitting the internal pressure to the main liquid chamber 35 through 2, it is possible to obtain an active vibration isolation effect against the vibration. Further, in this case, it is possible to obtain a more efficient active vibration damping effect by utilizing a flow action such as a resonance action of the fluid which is caused to flow through the orifice passage 42. In particular, in the present embodiment, the fluid flow through the fluid flow path 86 between the main liquid chamber 35 and the equilibrium chamber 82 is also generated based on the pressure change of the main liquid chamber 35. By utilizing the fluid flow through 86, a passive vibration isolating effect can be obtained in a frequency range different from the tuning frequency of the orifice passage 42, and an active vibration isolating effect can be efficiently obtained. Become.

Here, the vibration plate 74 is
Since the suction drive is performed by the action of the magnetic force generated in the yoke member 58 when the power is supplied to the yoke member 58, it is possible to efficiently obtain a large excitation force as compared with an electromagnetic drive unit such as a voice coil type. .

Further, on the inner peripheral side of the vibrating plate 74, the opposing portions of the vibrating plate 74 and the magnetic pole portion of the yoke member 58 are inclined in the axial direction so as to face each other. Even when 74 is displaced, the amount of change in the magnetic attraction force applied to the vibrating plate 74 with respect to the amount of change in the relative distance between the vibrating plate 74 and the yoke member 58 is suppressed to a small value. Even if the initial position of the vibration plate 74 with respect to the yoke member 58 varies, the desired vibration force is stably generated, and the desired active vibration isolation effect is stably exhibited. is there.

The technical reason why the amount of change in the magnetic attraction force due to the change in the relative position of the vibration plate 74 with respect to the yoke member 58 in the axial direction as described above is controlled is that the vibration plate 74 on the inner peripheral side thereof The direction in which the yoke member 58 faces the magnetic pole portion is inclined in the axial direction, so that the axial driving force is generated as a component force, and the vibration plate 74 and the yoke member 58
Are not only the axial end faces of the vibration plate 74 and the yoke member 58 but also the cylindrical inner and outer peripheral faces 94 and 96.
The yoke member 5 of the vibrating plate 74
It is considered that the effective magnetic pole portions of the vibrating plate 74 and the yoke member 58 are displaced with the axial displacement with respect to 8, respectively.

Incidentally, in the actuator 54 mounted on the engine mount 10 having the above structure, D =
FIG. 3 shows the result of determining the axial driving force (generated force) exerted on the vibrating plate 74 by supplying a constant current to the coil 64 at a setting of 1 mm. In addition, in such an actuator 54, as shown in FIG.
A position where the lower surface of the vibration plate 74 and the upper end surface in the axial direction of the inner peripheral side wall portion 66 of the yoke member 58 are on the same plane perpendicular to the axis is set as a reference position, and the vibration plate 74 is moved from the reference position to the yoke member 58. Axial driving force is determined for each of three positions, i.e., a separation position displaced by 1 mm in the separation direction with respect to the yoke member 58 and an approach position displaced by 0.5 mm in the direction of approach to the yoke member 58, and is generated at the reference position in FIG. It is shown as a ratio value to the generated force. In FIG. 3, the gap value indicates the value of M in FIG.

As a comparative example, as shown in FIG. 4, a yoke member 58a in which the inner peripheral side wall portion 66 and the outer peripheral side wall portion 68 have the same height in the axial direction, and the entire lower surface are flat. In a case where an actuator as a comparative example including the vibration plate 74a is employed, a position where the distance M between the yoke member 58a and the vibration plate 74a in the axial direction: M is set to 2.5 mm as a reference position. FIG. 3 shows the results obtained by calculating the axial driving force at three positions, i.e., a separation position 1 mm away from the camera and an approach position 0.5 mm closer.
Are also shown as comparative examples.

The results shown in FIG. 3 also show that the engine mount 10 employing the actuator 54 of the present embodiment is more vibrated than the engine mount using the actuator of the comparative example having a conventional structure. It is clear that even if there is the same variation in the relative position of the plate to the yoke member 58, the variation in the generated force can be greatly reduced. In other words, in the engine mount using the actuator of the comparative example having the conventional structure, in order to suppress the variation in the generated force to the same extent as in the engine mount 10 employing the actuator 54 of the present embodiment, it is necessary to use the vibration plate. The variation in position is shown by α in FIG.
It is necessary to keep it within a very narrow range indicated by the following.

The embodiment of the present invention has been described in detail above, but this is merely an example.
By the specific description in such an embodiment,
It is not to be construed as limiting.

For example, in the engine mount 10 of the above embodiment, the outer peripheral side wall 68 of the yoke member 58 and the vibration plate 7
An axially opposed portion is formed between the inner peripheral portion of the yoke member 58 and the inner peripheral portion of the vibrating plate 74. On the contrary, the outer peripheral side wall 68 of the yoke member 58 and the outer peripheral part of the vibrating plate 74 are formed on the contrary, as schematically shown in FIGS. It is also possible to form an opposing portion that is shifted in the direction perpendicular to the axis and inclined in the axial direction. In addition, in FIGS.
In order to facilitate understanding, members and portions having the same structure as the actuator 54 of the engine mount 10 in the above embodiment are denoted by the same reference numerals in the drawings.

That is, in the engine mount actuator shown in FIG. 5, the outer peripheral side wall portion 68 is projected upward in the axial direction than the inner peripheral side wall portion 66 of the yoke member 58. As the vibration plate 74, one having a flat lower surface over its entirety is employed, and the outer diameter of the vibration plate 74 is slightly smaller than the inner diameter of the outer peripheral side wall 68 of the yoke member 58. Is set. In the engine mount actuator shown in FIG. 6, the inner peripheral side wall 66 and the outer peripheral side wall 68 of the yoke member 58 both protrude upward in the axial direction, and the lower surface extends over the entirety. At the outer peripheral edge of the vibration plate 74 having a flat surface, an annular projecting portion 104 protruding downward in the axial direction is integrally formed with an outer diameter slightly smaller than the inner diameter of the outer peripheral side wall 68 of the yoke member 58. Have been. Further, in the engine mount actuator shown in FIG. 7, the yoke member 58 having the same structure as that of the above-described embodiment, in which the inner peripheral side wall portion 66 is projected upward in the axial direction than the outer peripheral side wall portion 68. The annular projection 106 projecting downward in the axial direction is formed on the outer peripheral edge of the vibration plate 74 having a flat lower surface over the entire outer peripheral side wall 68 of the yoke member 58. It is integrally formed with an inner diameter slightly larger than the diameter.

In each of the engine mount actuators shown in FIGS. 5 to 7, the axially upper end surface of the inner peripheral side wall portion 66 of the yoke member 58 and the vibrating plate 7
4 are directly opposed to each other in the axial direction to exert an effective magnetic attraction force, and the upper end portion of the yoke member 58 in the axial direction of the outer peripheral side wall portion 68 and the vibration plate 74 are inclined in the axial direction to the opposed position. The variation in the excitation force resulting from the variation in the relative position of the vibration plate 74 with respect to the yoke member 58 in the axial direction is effectively reduced.
As a result, an exciting force is applied stably, and the same effect as that of the actuator in the above-described embodiment is effectively exhibited.

Further, in the active mount having the structure according to the present invention, at least one of the inner and outer peripheral side walls of the yoke member constituting the actuator is directly opposed to the vibration member in the axial direction. Is provided, and at least the other of the inner and outer peripheral wall portions may be provided with a portion which is at least displaced in the direction perpendicular to the axis with respect to the vibrating member and is inclined and opposed.
For example, at one of the inner and outer peripheral side walls of the yoke member provided with a portion directly opposed to the vibrating member in the axial direction, the portion is further inclined and shifted in the direction perpendicular to the axis with respect to the vibrating member. The inner and outer peripheral wall portions of the yoke member are provided with a portion that is opposed to the vibrating member while being inclined and displaced in a direction perpendicular to the axis. On the other hand, it is also possible to additionally provide a portion which is directly opposed to the vibration member in the axial direction.

Specifically, for example, as shown in FIG. 8, both the inner peripheral side wall portion 66 and the outer peripheral side wall portion 68 of the yoke member 58 are projected upward in the axial direction, and the lower surface is entirely formed. An annular projection 108 projecting axially downward at a radially intermediate portion of the vibration plate 74 having a flat surface extending therethrough.
An active mount having an integrally formed structure having an inner diameter slightly larger than the outer diameter of the inner peripheral side wall 66 of the yoke member 58 and an outer diameter slightly smaller than the inner diameter of the outer peripheral side wall 68 in the yoke member 58 is provided. It is also possible to configure an actuator for the same. In the active mounting actuator having such a structure, the lower surface of the vibrating plate 74 and the upper end surfaces in the axial direction of the inner peripheral side wall portion 66 and the outer peripheral side wall portion 68 of the yoke member 58 are directly connected in the axial direction, respectively. And the inner peripheral corner of the annular projection 108 of the vibration plate 74, the outer peripheral corner of the inner peripheral side wall 66 of the yoke member 58, and the annular projection 108 of the vibration plate 74. Outer peripheral side corner of yoke member 58 and outer peripheral side corner 6 of yoke member 58
8, the inner peripheral side corners are respectively opposed to each other with a shift in a direction perpendicular to the axis. In short, in such an actuator, in both the inner peripheral side wall portion 66 and the outer peripheral side wall portion 68 of the yoke member 58, the magnetic pole portion directly facing the vibration plate 74 in the axial direction and the axially perpendicular direction The magnetic pole portions that are deviated and inclined to face each other are formed. In the active mounting actuator having such a structure, the vibration plate 7
The variation in the excitation force caused by the variation in the relative position in the axial direction with respect to the yoke member 58 of No. 4 is effectively reduced, and the excitation force is exerted on the excitation plate 74 stably. The same effect as that of the active mounting actuator in the embodiment is effectively exerted.

The orifice passage 42 and the fluid passage 86
The specific structure is not limited and is appropriately changed in accordance with the required vibration isolation characteristics, the basic structure of the vibration isolation device, and the like.

Further, the present invention can be applied not only to a mount having a structure as illustrated, but also to an outer cylindrical member serving as a second mounting member, for example, being spaced radially outward from a shaft member serving as a first mounting member. Is disposed, and the shaft member and the outer cylinder member have a structure in which they are connected by a main rubber elastic body interposed between the two members, and are suitably adopted for an engine mount for an FF type automobile and the like. It is also applicable to cylindrical mounts and the like.

Further, in the above-described embodiment, a specific example in which the present invention is applied to an engine mount for an automobile is shown. However, in addition to the engine mount for an automobile, various mounts for an automobile and various other devices are also provided. Of course, the present invention is applicable.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be performed in embodiments, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Needless to say.

[0063]

As is apparent from the above description, in the fluid-filled active mount having the structure according to the present invention, the portion where magnetic force is exerted between the yoke member and the vibration member is vibrated. By tilting and opposing to the displacement direction of the member, the variation in the driving force of the vibrating member due to the variation in the relative position of the yoke member and the vibrating member can be suppressed. The active vibration isolation effect can be effectively and stably exhibited. Therefore, for example, even when there is a possibility that the initial load input in the mounted state may affect the relative position between the yoke member and the vibrating member in the vibrator, the active vibration isolation characteristics are stabilized. It can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing an automobile engine mount as one embodiment of the present invention.

FIG. 2 is a model diagram showing a main part of an actuator used in the engine mount shown in FIG.

FIG. 3 is a graph showing output characteristics of an actuator used in the engine mount shown in FIG.

FIG. 4 is a model diagram showing a main part of an actuator used for an engine mount having a conventional structure as a comparative example.

FIG. 5 is a schematic view of a main part showing another structural example of an actuator that can be employed in the engine mount shown in FIG. 1;

FIG. 6 is a schematic view of a main part showing still another structural example of an actuator that can be employed in the engine mount shown in FIG. 1;

FIG. 7 is a schematic diagram of a main part showing still another structural example of an actuator that can be employed in the engine mount shown in FIG. 1;

FIG. 8 is a schematic view of a main part showing still another structural example of an actuator that can be employed in the engine mount shown in FIG. 1;

DESCRIPTION OF SYMBOLS 10 Engine mount 12 First mounting bracket 14 Second mounting bracket 16 Main rubber elastic body 34 Partition member 35 Main liquid chamber 42 Orifice passage 44 Movable wall 52 Secondary liquid chamber 54 Actuator 58 Yoke member 64 Coil 66 Inner peripheral side wall 68 Outer peripheral side wall 74 Vibration plate 82 Equilibrium chamber 86 Fluid flow path 90 Central recess 98 Outer peripheral edge 100 Opening corner

Claims (6)

[Claims] 1. A first mounting member and a second mounting member which are respectively attached to members to be vibration-isolated are connected by a main rubber elastic body, and a part of a wall portion is constituted by the main rubber elastic body. To form a fluid chamber in which an incompressible fluid is sealed, another part of the wall of the fluid chamber is formed of a displaceable movable wall, and an actuator for driving the movable wall to vibrate is provided. In the fluid-filled active mount, an annular groove that opens to one side in the axial direction with respect to the yoke member made of a magnetic material is provided, and the coil is housed and arranged in the annular groove. A magnetic path is formed around the coil, and both magnetic poles of the magnetic path are set on the inner peripheral side wall and the outer peripheral side wall of the opening of the annular groove in the yoke member. The vibration member made of The coil member is spaced apart from the opening side of the annular groove in the axial direction and is opposed to the opening in the axial direction. When a current is applied to the coil, a magnetic force is exerted on the vibrating member, and an axial direction By using an electromagnetic vibrator adapted to exert a vibrating force, the yoke member is fixedly supported by the second mounting member, and the vibrating member is fixedly provided on the movable wall. Constituting the actuator for exerting an exciting force on the movable wall,
Further, in such an actuator, at least one of the inner peripheral side wall part and the outer peripheral side wall part of the opening of the annular groove in which the magnetic pole of the yoke member is set, and the inner periphery of the vibrating member positioned closest thereto. While the part and / or the outer peripheral part are directly opposed in the axial direction,
At least the other corner portion of the inner peripheral side wall portion and the outer peripheral side wall portion of the yoke member and the corner portion of the inner peripheral portion and / or the outer peripheral portion of the vibrating member positioned closest to the yoke member are aligned in a direction perpendicular to the axis. A fluid-filled active mount characterized in that the fluid-filled active mount is displaced in the axial direction so as to be opposed. 2. A main liquid chamber in which a part of a wall portion is formed of the main rubber elastic body by partitioning the fluid chamber by a partition wall supported by the second mounting member; 2. The fluid-filled active mount according to claim 1, wherein a sub-liquid chamber partially formed by the movable wall is formed, and an orifice passage communicating the main liquid chamber and the sub-liquid chamber is formed. 3. The vibrating member is displaced toward the yoke member side in the actuator,
The exciter member and the yoke member are shifted from each other in the direction perpendicular to the axis so that the tip surfaces of the portions that are inclined in the axial direction and face each other can reach at least a position overlapping in the direction perpendicular to the axis without abutting each other. Claim 1 or 2
A fluid-filled active mount according to claim 1. 4. The inner and outer peripheral surfaces of the vibrating member and the yoke member of the actuator, which are displaced in the direction perpendicular to the axis and inclined in the axial direction to be opposed to each other, are close to each other in the axial direction. And a radial dimension of the inner peripheral surface and the outer peripheral surface is set so that a gap is formed between the inner and outer peripheral surfaces in the axial projection. A fluid-filled active mount according to any of the preceding claims. 5. The magnitude of the distance between the opposing surfaces of the vibrating member and the yoke member of the actuator, which are displaced in the direction perpendicular to the axis and inclined in the axial direction to be opposed to each other, is set in the axial direction. The fluid-filled active mount according to any one of claims 1 to 4, wherein the distance between the opposing surfaces of the portions directly opposed to each other is smaller than the distance. 6. The actuator, wherein an inner peripheral side wall portion of the yoke member is made to protrude more axially than an outer peripheral side wall portion, and a recess is formed at a central portion of an axially facing surface of the vibrating member with respect to the yoke member. The outer peripheral portion of the axially facing surface of the vibrating member is directly opposed to the outer peripheral side wall portion of the yoke member in the axial direction, and the opening corner of the recess of the vibrating member is formed by the yoke. The outer peripheral corner of the inner peripheral side wall of the member is inclined in the axial direction to be opposed to the outer peripheral corner, and the bottom surface of the concave portion of the vibrating member is vibrated with respect to the inner peripheral side wall of the yoke member. 6. The device according to any one of claims 1 to 5, wherein the member is directly opposed in the axial direction with a distance between opposing surfaces larger than a distance between opposing surfaces of the opening corner of the member and the outer corner of the inner peripheral side wall of the yoke member. Fluid enclosure active mount.