JP2921961B2 - Fluid filled control type vibration damping device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a fluid filling control in which a vibration damper having a fluid filled therein is used to suppress vibration during idling of an engine and vibration based on an engine shake. The present invention relates to a mold vibration isolator.

2. Description of the Related Art Generally, an engine mount using a fluid-filled vibration isolator includes a first fluid chamber surrounded by an elastic body such as rubber,
A fluid having a predetermined viscosity is sealed in a second fluid chamber separated by a diaphragm, and both fluid chambers are communicated via an orifice. Small-amplitude vibration is absorbed by deformation of the elastic body, while large-amplitude vibration is absorbed. The vibration is caused to flow and absorb the fluid between the first fluid chamber and the second fluid chamber with the deformation of the elastic body. According to such an engine mount, with respect to input vibration in a relatively low frequency region such as normal idling vibration or engine shake,
The flow state of the fluid in the orifice formed in the vibration isolator changes, and the vibration transmitted to the vehicle body can be reduced.

With respect to the above, for example, JP-A-62-180130 discloses that a cylindrical housing is fixed on a vehicle body frame and attached to a state in which a conical cylindrical elastic body is covered on an upper surface of the housing. While being fixed to the support of the power unit as the vibration source, the partition is fixed to the inside of the cylindrical housing and divided into an upper first fluid chamber and a lower second fluid chamber. A configuration is disclosed in which a diaphragm made of thin rubber that can be easily deformed is provided in a two-fluid chamber. The partition plate includes a disk-shaped fixed plate and a ring-shaped movable plate, and a through hole having a relatively small area is provided on an outer peripheral portion of the fixed plate. An arc-shaped groove is formed at a position corresponding to the above, and the movable plate is rotated by the driving force of the actuator to adjust the effective passage area of the orifice between the first fluid chamber and the second fluid chamber. Is possible.

According to the control type vibration damping device, the dynamic spring constant during idling is reduced by increasing the effective passage area of the orifice between the first fluid chamber and the second fluid chamber during idling of the vehicle. While reducing the vibration input, when the vehicle speed is at the vehicle speed at which engine shake occurs, the effective passage area of the orifice between the first fluid chamber and the second fluid chamber is adjusted to be small, so that The damping force is increased, and the vibration transmitted from the power unit to the vehicle body due to the engine shake can be reduced.

However, in the case of such a conventional fluid-filled control type vibration damping device, the partition plate separating the first and second fluid chambers is composed of a fixed plate and a movable plate. By rotating the movable plate superimposed in the vertical direction with respect to
Since the effective passage area of the orifice between the fluid chambers is changed, the restraining directions of the fixed plate and the movable plate coincide with the vertical vibration of the power unit as a vibration source. As a result, the vibration source There is a problem that a resonance system is formed between the fixed plate and the movable plate, and a "leak" phenomenon of fluid may occur between the fixed plate and the movable plate.

When such a fluid "leak" occurs, the effective passage area of the orifice between the first fluid chamber and the second fluid chamber cannot be adjusted to a desired state with the rotation of the movable plate. In other words, the fluid flows more than the flow rate regulated by the orifice, and there is a problem that the vibration damping action of the engine shake is mainly reduced.

Further, means for increasing the restraining force between the fixed plate and the movable plate to prevent the "leak" can be considered, but in such a case, the driving force for rotating the movable plate must be increased. However, there is a problem that the size of the actuator is increased.

Therefore, the present invention solves the problems of the conventional fluid-filled control type vibration damping device, and eliminates the "leakage" of the fluid between the first and second fluid chambers, and furthermore, the orifice passage. It is an object of the present invention to provide a fluid-filled control type vibration damping device that can keep a driving force for changing an area small.

Means for Solving the Problems In order to achieve the object, the present invention provides a fluid-filled control type vibration isolator which is disposed between a vehicle body and a power unit and supports the power unit in a vibration isolating manner. A housing capable of containing a fluid, a support elastic body made of rubber or the like, which is vulcanized and adhered to the inner wall surface of the housing and has a shaft for supporting the power unit fixed at a substantially central position, and a space adjacent to the support elastic body An orifice structure disposed in the first portion, the first and second fluid chambers having a first fluid chamber and a second fluid chamber in which a fluid is sealed; A diaphragm made of thin rubber mounted on the lower side of the fluid chamber, wherein the orifice structure is fixed to the body of the housing and has a first spiral orifice formed on the inner wall surface. An outer cylindrical member formed, a cylindrical member fitted in the outer cylindrical member so as to be slidable and rotatable and having a helical second orifice formed on an outer wall surface; A fluid circulation hole opened at both ends of the orifice; and an actuator for driving the cylindrical member to rotate. The first orifice and the second orifice according to the rotation angle of the cylindrical member. Thus, a fluid-filled control type vibration damping device is configured to select either the composite orifice or the second orifice obtained by combining the two.

According to this configuration, by rotating the columnar member based on the driving force of the actuator, when the vehicle is in an idling state, the first fluid having a large flow rate is provided.
By communicating the first fluid chamber and the second fluid chamber by a composite orifice of the orifice and the second orifice, the dynamic spring constant during idling is reduced and the vibration input to the vehicle body is reduced, while the When the vehicle speed reaches the vehicle speed at which the engine shake occurs, the damping force of the vibration isolator is increased by communicating between the first fluid chamber and the second fluid chamber by the second orifice having a small flow rate of the fluid. Thus, the vibration transmitted from the power unit to the vehicle body due to the engine shake is reduced.

Further, since the orifice constituting body separating the first fluid chamber and the second fluid chamber is constituted by the outer cylinder member and the columnar member fitted to each other, the power unit as the vibration source is provided. The restraining directions of the outer cylinder member and the columnar member are different with respect to the vertical vibration, so that a resonance system is prevented from being formed between the outer cylinder member and the columnar member, and the fluid between the two members is prevented. The "leak" phenomenon does not occur, the sealing property is maintained well, and the vibration damping action of the engine shake is mainly enhanced.

Hereinafter, an embodiment of a fluid filled control type vibration damping device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external view of a vibration isolator 10 according to the present embodiment, and FIG.
The figure is a sectional view along the line II-II in FIG. In the figure, reference numeral 1 denotes a housing having an inverted U-shaped cross section. A bumper rubber 3 is fixed to an inner wall surface of an upper wall portion 1a of the housing 1, and a rubber or the like is provided below the bumper rubber 3 via a minute space 5 below. The supporting elastic body 7 is vulcanized and bonded.

A projection 7a is formed on the upper surface of the support elastic body 7 to contact the bumper rubber 3 at the time of vibration, and a shaft 9 formed of a cylindrical body penetrates a substantially central position of the support elastic body 7. Fixed. Both ends of the shaft 9 protrude from a window 11 (11) opened in the housing 1 and are attached to a bracket for supporting a power unit (combined body such as an engine and a transmission) (not shown). The load is supported on the vehicle body via the support elastic body 7.

In a space formed below the supporting elastic body 7, an orifice constituting body 13, which is a characteristic constitution of the present embodiment, is disposed. A first fluid chamber 20 is formed between the orifice component 13 and the upper elastic support member 7, and a second fluid chamber 30 is provided between the orifice component 13 and a diaphragm 29 described later.
Is formed. The first fluid chamber 20 and the second fluid chamber 30
Is filled with a fluid having a predetermined viscosity. In other words, the first fluid chamber 20 and the second fluid chamber 30 filled with fluid are vertically separated by the orifice structure 13.

The detailed structure of the orifice structure 13 will be described with reference to FIGS. 2 and 3.

Reference numeral 15 denotes an outer cylinder member. The outer wall surface of the outer cylinder member 15 is fixed to the body 1b of the housing 1, and a spiral first orifice 17 is formed on the inner wall surface of the outer cylinder member 15. ing. In the illustrated example, the upper and lower ends of the first orifice 17 are not connected to the first fluid chamber 20 and the second fluid chamber 30.

On the other hand, reference numeral 19 denotes a cylindrical member. The cylindrical member 19 is slidably fitted inside the outer cylindrical member 15 so as to be able to slide and rotate. 2 orifices
21 are formed. At the upper end of the second orifice 21, a fluid flow hole 21a communicating with the first fluid chamber 20 and having a sectional area equal to the sum of the sectional areas of the first orifice 17 and the second orifice 21 is formed. The second orifice 21
Communicates with the second fluid chamber 30 at the lower end of the first orifice.
A fluid flow hole 21b having a cross-sectional area equal to the sum of the cross-sectional areas of 17 and the second orifice 21 is opened.

Then, the cylindrical member 19 is slidably inserted inside the outer cylindrical member 15 so that the orifice structure
13 is formed. A rod 27 is integrally protruded downward from the lower surface of the columnar member 19.

Reference numeral 23 denotes an actuator that rotationally drives the columnar member 19, and an operation rod protruding from the actuator 23.
25 extends inward into the second fluid chamber 30 via an O-ring 31, and a bevel gear 25 fixed to the distal end of the operating rod 25.
a meshes with a bevel gear 27a fixed to the lower end of the rod 27 protruding from the lower surface of the columnar member 19.

Further, a diaphragm 29 made of thin rubber is attached to a lower portion of the second fluid chamber 30. The peripheral edge 29a of the diaphragm 29 is fixed to the lower surface of the base 1c of the housing 1.

According to the configuration of the vibration isolator 10, both ends of the shaft 9 penetrating substantially at the center of the support elastic body 7 are attached to brackets for supporting a power unit (not shown), and the base 1c of the housing 1 is attached to a vehicle body (not shown). By fixing the power unit to the image member by means such as bolting, the static load of the power unit is supported via the support elastic body 7. In addition, in order to elastically support a normal power unit, the above-described vibration isolator is required.
10 are located in at least one of all mounts supporting the engine.

 The actual example of the control according to the present embodiment will be described above.

As described above, when the vibration damping device 10 according to the present embodiment is used as an engine mount of a vehicle, first, when the vehicle is in an idling state, by driving the actuator 23, the rotational force of the actuator 23 is reduced. The transmission is transmitted from the bevel gear 25a of the operating rod 25 to the bevel gear 27a of the rod 27, and the cylindrical member 19 is rotated by the action of the rod 27 to be set in the state shown in FIGS. You. That is, in this state, the first orifice 17 formed on the inner wall surface of the outer cylindrical member 15 and the second orifice formed on the outer wall surface of the columnar member 19 coincide with each other.
The orifice 17 and the second orifice 21 are combined to form a composite orifice 33 having a large flow cross-sectional area, and the first fluid chamber 20 and the second fluid chamber 30 as shown by arrows A and A in FIG.
Can be circulated through the composite orifice 33.

Since the flow rate of the fluid flowing through the composite orifice 33 is the total flow rate of the fluid flowing through the first orifice 17 and the second orifice 21, the first or second orifice 17, 21 is used alone. It is a larger circulation volume than if it were.

Accordingly, the dynamic spring constant of the vibration isolator 10 is reduced in accordance with the resonance of the fluid, and particularly the dynamic spring constant during idling is reduced, so that the vibration input transmitted from the power unit to the vehicle body can be reduced.

That is, the flow rate of the fluid in the composite orifice 33 is
Engine speed during idling (normally 600 to 900 rpm)
It is tuned so as to obtain a low dynamic spring characteristic in the vicinity of 20 to 300 Hz, which is the second-order component.

Next, when the vehicle starts and the vehicle speed reaches the vehicle speed at which the engine shake occurs, the actuator is actuated as described above.
By transmitting the torque of 23 from the operating rod 25 to the rod 27, the columnar member 19 rotates by a predetermined angle. Then, as shown in FIG. 5, the first orifice 17 formed on the inner wall surface of the outer cylindrical member 15 and the second orifice 21 formed on the outer wall surface of the columnar member 19 are in a mismatched state. .
As described above, the upper and lower ends of the first orifice 17 are not communicated with the first fluid chamber 20 and the second fluid chamber 30, but the upper and lower ends of the second orifice 21 are respectively formed with the flow holes 21a. ,
Since the first fluid chamber 20 and the second fluid chamber 30 communicate with each other by the first fluid chamber 21b, the first fluid chamber 20 and the second
Through the orifice 21.

The flow rate of the fluid flowing through the second orifice 21 is
Since the flow rate of the fluid flowing through the composite orifice 33 is smaller than that of the second orifice 21, the flow rate of the fluid in the second orifice 21 is reduced, and the rigidity of the vibration isolator 10 itself is increased. By increasing the force, vibrations caused by the engine shake transmitted from the power unit to the vehicle body can be reduced.

To summarize the above operation, by rotating the cylindrical member 19 based on the driving force of the actuator 23, when the vehicle is in an idling state, the first fluid chamber 20 is connected to the first fluid chamber 20 by the composite orifice 33 having a large fluid flow rate. Second fluid chamber 30
When the vehicle speed reaches the vehicle speed at which engine shake occurs, the flow rate of the fluid is small, while the dynamic spring constant during idling decreases and the vibration input to the vehicle body side decreases. The communication between the first fluid chamber 20 and the second fluid chamber 30 by the second orifice 21 increases the damping force of the vibration isolator 10 and reduces the engine shake transmitted from the power unit to the vehicle body.

According to the present embodiment, the orifice structure 13 separating the first fluid chamber 20 and the second fluid chamber 30 is formed by the outer cylindrical member 15 and the cylindrical member 19 which are slidably and rotatably fitted to each other. As a result, the restraining directions of the outer cylindrical member 15 and the cylindrical member 19 are different with respect to the vertical vibration of the power unit as the vibration source, and therefore, the outer cylindrical member 15 and the cylindrical member 19 It is characterized in that the formation of a resonance system therebetween is prevented, and the "leakage" phenomenon of fluid does not occur between them. That is, since the cylindrical member 19 is rotating while closely sliding on the inner wall surface of the outer cylindrical member 15, even when vertical vibration from the vibration source is applied to the sliding contact portion, There is no influence on the liquid-tightness between the outer cylindrical member 15 and the columnar member 19, the sealing property is maintained well, and the vibration damping action of the engine shake is mainly enhanced.

Furthermore, since it is not necessary to particularly increase the binding force between the outer cylinder member 15 and the columnar member 19 in order to prevent the above “leak”, there is an advantage that it is not required to increase the size of the actuator 23.

Effect of the Invention As described above, in the fluid-filled control type vibration isolator according to the present invention, the columnar member is rotated based on the driving force of the actuator, and when the vehicle is in an idling state, the fluid is prevented from flowing. The communication between the first fluid chamber and the second fluid chamber by the composite orifice having a large flow volume reduces the dynamic spring constant of the vibration isolator and reduces vibration input to the vehicle body, while reducing the vehicle speed of the vehicle. When the vehicle speed at which the engine shake occurs occurs, the damping force of the vibration isolator is increased by communicating between the first fluid chamber and the second fluid chamber by the second orifice having a small fluid flow rate, Vibration transmitted from the power unit to the vehicle body due to the engine shake can be reduced.

Also, since the orifice structure separating the first fluid chamber and the second fluid chamber is constituted by the outer cylindrical member and the columnar member which are slidably and rotatably fitted to each other, vibration is generated. The restraining directions of the outer cylindrical member and the columnar member are different with respect to the vertical vibration of the power unit as a source, so that a resonance system is prevented from being formed between the outer cylindrical member and the cylindrical member. As a result, the "leak" phenomenon of the fluid does not occur between the two, the sealing property is maintained well, and the damping action of the engine shake can be mainly improved.

That is, since the columnar member is rotating while being in close sliding contact with the inner wall surface of the outer cylindrical member, even when vertical vibration from the vibration source is applied to the sliding contact portion, the columnar member is cylindrical. There is no effect on the liquid tightness between the member and the outer cylindrical member, and there is no need to particularly increase the restraining force between the outer cylindrical member and the columnar member. Therefore, it is possible to obtain an effect that it is not necessary to increase the size of the actuator. .

[Brief description of the drawings]

1 is an external view of a vibration isolator according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, FIG. 3 is an exploded cross-sectional view showing only essential parts of FIG. FIG. 4 and FIG. 5 are cross-sectional views of essential parts showing aspects during operation. DESCRIPTION OF SYMBOLS 1 ... Housing, 7 ... Elastic support body, 9 ... Shaft, 10 ... Vibration isolator, 13 ... Orifice structure, 15 ... Outer cylinder member, 17 ... First orifice, 19 ... Circle Column-shaped member, 20 first fluid chamber, 21 second orifice, 21a, 21b communication hole, 23 actuator, 25 operating rod, 27 rod, 29 diaphragm, 30 ... second fluid chamber, 33 ... composite orifice.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Norio Yoda 330, Naganuma-cho, Chiba City, Chiba Prefecture Inside Kinugawa Rubber Industries, Ltd. (56) References JP-A-2-46337 (JP, A) JP-A-1- 158243 (JP, A) JP-A-62-180130 (JP, A) JP-A-62-156639 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16F 13/00

Claims (1)

(57) [Claims] 1. A fluid filled control type vibration damping device disposed between a vehicle body and a power unit and supporting the power unit in a vibration damping manner, wherein the vibration damping device has a housing capable of filling a fluid, and an inner wall surface of the housing. Elastic body made of rubber or the like, which is vulcanized and bonded to a shaft and supports a power unit at a substantially central position, and a first fluid which is disposed in a space adjacent to the elastic body and is filled with a fluid. An orifice structure that separates the chamber from the second fluid chamber, and a diaphragm made of thin rubber attached to one side of the second fluid chamber. An outer cylindrical member fixed to the portion and having a spiral first orifice formed on the inner wall surface, and slidably fitted inside the outer cylindrical member so as to be slidably contactable and spirally formed on the outer wall surface. of A cylindrical member having two orifices formed therein, a fluid circulation hole opened at both ends of the second orifice, and an actuator for rotating and driving the cylindrical member. A fluid filled control type vibration damping device characterized in that either one of a composite orifice obtained by combining the first orifice and the second orifice or a second orifice is selected according to the rotation angle of the fluid.