JPH0232902Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a fluid-filled bushing with variable damping force.

(Prior Art) In the suspension of a vehicle, a variable damping force type fluid-filled bushing is provided at the end of a suspension arm. Some are equipped with a protruding drive control device for varying the force.

Such a variable damping force fluid-filled bushing has a rubber wall that connects the inner and outer cylinders to form a plurality (generally two) of fluid chambers between the inner and outer cylinders, and a holding cylinder that holds the outer cylinder. A communication path is provided between the holding cylinder and the outer cylinder and in the outer cylinder to communicate each fluid chamber, and a valve whose flow area is variable is provided in this communication path. The damping force is configured to be changed by switching and driving by a drive control device.

Conventional valves are solenoid valves that open and close communication passages, as typified by the above-mentioned publication.
The compliance characteristics were switched to two levels.

(Problem that the invention attempts to solve) In this way, conventionally the compliance characteristics were
It was only a step change.

Therefore, the purpose of this invention is to improve the valve,
It is an object of the present invention to provide a variable damping force type fluid-filled bushing that realizes variable compliance characteristics in three or more stages and also facilitates the assembly of valves and the like.

(Means for Solving the Problems) In order to solve the above object, the present invention provides an opening 23 facing the communication path 18 provided between the outer cylinder 13 of the fluid-filled bushing 11 and the holding cylinder 21 in the holding cylinder 21. A pedestal 25 having a cylindrical portion 29 that fits into the opening 23 is fixed to the outer periphery of the holding cylinder 21, and a valve 51 provided with at least two valve holes 56, 57 is rotatably held. Valve holder 49
is fitted into the cylindrical portion 29 of the pedestal 25, and a drive control device 61 for rotating the valve 51 is attached to the pedestal 25.

(Function) By rotating the valve 51, the flow path area can be changed to three or more stages.
Since it is only necessary to insert the drive control device 61 into the cylindrical portion 29 of the pedestal 25 and attach the drive control device 61 to the pedestal 25, the assembly work is simple.

(Example) Examples will be described in detail below based on the accompanying drawings.

Figure 1 is a partial side view of the suspension arm.
FIG. 2 is an enlarged side view showing the fluid-filled bush in longitudinal section.

Radius slot 1 that forms the suspension arm
is made of pipe, the pipe end 2 is slightly bent downward with respect to the rod center line C, and a reinforcing plate 4 facing upward across the pipe end 2 and the rod center line C is placed near the pipe bend 3. In this way, the ends of the radius slot 1 are formed into upper and lower bifurcated portions 10. Such bifurcated portions 10 are constructed at both ends of the radius slot 1. Further, an under guard plate 7 is provided at the pipe end 2 bent downward.

Both the reinforcing plate 4 and the under guard plate 7 are of a channel type, and the side edges 5 and 8 protruding outward are joined and fixed at the pipe bending part 3, and a fluid is inserted between the front parts of the reinforcing plate 4 and the under guard plate 7. Entering button 1
1 is held, and its leading edges 6 and 9 are joined and fixed.
In addition, the tip of the pipe end 2 is connected to a fluid-filled bush 11.
Formed in an arc shape that follows the outer circumference of the

As shown in FIG. 3, the main body of the fluid-filled bush 11 includes an inner cylinder 12, an outer cylinder 13, and a holding cylinder 21.
It consists of a rubber wall 31 that connects the inner and outer cylinders 12 and 13.

A rubber wall 31 baked onto the outer periphery of the inner cylinder 12 and the inner periphery of the outer cylinder 13 is continuous with rubber wall parts 32, 32 that close between the inner and outer cylinders 12, 13 at both ends in the length direction of the cylinder. , inner and outer cylinders 1 at the middle part in the length direction of the cylinder
2 and 13 into two fluid chambers 0 ₁ and 0 ₂ . In addition, the rubber wall part 33 in the middle part
A stopper protrusion 34 that protrudes into both fluid chambers 0 ₁ , 0 ₂ is provided around the inner cylinder 12 , and a metal restraint ring is provided near the outer periphery of the rubber walls 32 , 32 at both ends. Boards 35, 35 are buried.

On the other hand, both lengthwise ends of the outer cylinder 13 are caulked to form inner flanges 14, 14, and the inner flanges 14, 14 are pressed against the ends of the restraining ring plates 35, 35, respectively. The outer cylinder 13 is attached to the holding cylinder 2.
1 and the outer periphery of the outer cylinder 13 and the holding cylinder 21.
The inner periphery is the full-circumference recess 1 at the middle part in the length direction of the cylinder.
5, 22 are formed, and seal rings 19, 19 are fitted between both longitudinal ends of the cylinder. Furthermore, the outer cylinder 13
There are circular holes 16 that open into the internal fluid chambers 0 ₁ and 0 ₂ .
..., 17 are formed on the surface of the recess 15. That is, one relatively large circular hole 17 is opened in one fluid chamber 0 ₂ , and three relatively small circular holes 16 are opened in the other fluid chamber 0 ₁ . In this way, a communication path 18 is created which communicates both the fluid chambers 0 ₁ and 0 ₂ between the circumferential recesses 15 and 22 between the outer cylinder 13 and the holding cylinder 21 and through the circular holes 16 . . . , 17 formed in the outer cylinder 13. Configure.

The holding cylinder 21 has the larger circular hole 17.
A circular hole 23 that is concentric with and larger is opened, and a cylinder 29 is tightly fitted into this circular hole 23 from the outside. This cylinder 29 is integrated with the pedestal plate 25, and its tip end is connected to the holding cylinder 21 in FIG.
It is flush with the inner circumferential surface of. Also pedestal board 2
5, as shown in FIG. 4, one joint piece 26 extending upward and two left and right joint pieces 2 extending downward.
7 and 27, and a cylinder 29 is fitted and fixed in the center of a pedestal part 28 in the middle thereof. This pedestal board 2
The joint pieces 26, 27, 27 of No. 5 are jointed and fixed to the outer periphery of the holding cylinder 21.

The holding cylinder 21 is fitted between the reinforcing plate 4 and the tip of the under guard plate 7, with the pipe end 2 facing between the joining pieces 27, 27 below the base plate 25, and These are joined and fixed together. Thus, the bifurcated portion 1 at the end of the radius slot 1
A fluid-filled bush 11 is held and fixed at the 0 end.

In the above, an opening 71 is formed at the tip of the under guard plate 7, and a drain hole 24 is formed through the holding cylinder 21, which is coaxial with the opening 71 and faces the communication path 18. A drain pipe 72 that is fitted and connected to the drain pipe 72 and protrudes from the opening 71
Screw on the drain socket 73.

The cylinder 29 of the pedestal plate 25 faces into the space S formed between the bifurcated portion 10 at the end of the radius slot 1.
A valve holder 41 is fitted inside. The valve holder 41 has a cylindrical shape, the outer periphery of the base is formed into a large diameter part 42 that fits inside the cylinder 29, a seal ring 43 is fitted to this large diameter part 42, and the large diameter part 42 is fitted with a seal ring 43.
An outer flange 44 having a larger diameter than the cylinder 29 is provided at the end. In addition, the outer periphery of the tip is connected to the larger circular hole 17.
This small diameter portion 45 is formed into a smaller diameter portion 45.
A rubber tube 47 that fits tightly into the circular hole 17 is fitted in the small diameter portion 45 and the rubber tube 47, and through holes 46 and 48 are opened in the small diameter portion 45 and the rubber tube 47 to penetrate in the radial direction. here,
The outer circumference of the rubber cylinder 47 has a smaller diameter than the inner circumference of the cylinder 29.

The valve 51 is rotatably fitted into the holding cylinder 41. The valve 51 has a base portion formed as a small diameter rod portion 52, a seal ring 53 fitted around the outer periphery of the rod portion 52, and a shaft hole 54 formed at the end of the rod portion 52. Further, the tip portion is formed into a cylindrical portion 55 having a large diameter, and this cylindrical portion 55 is provided with two valve holes 56 and 57 passing through it in the radial direction, as shown in FIG. Here, one valve hole 56 is connected to the through hole 4.
The valve hole 57 is made to have the same diameter as 6 and 48, and the valve hole 57 at a portion having a center angle different from this by 120 degrees has a smaller diameter.

The above-mentioned valve 51 is rotatably assembled inside the holder 41, and a rod portion 52 protrudes from the end of the holder 41.
A circlip 59 is fitted to the end to prevent it from coming off, and the holder 41 incorporating the valve 51 is assembled into the cylinder 29 of the base plate 25, and the through hole 46 of the holder 41 and the rubber tube 47 is inserted. 48 to the communication path 18
Let's face it.

A drive control device 61 for the valve 51 is attached to the pedestal portion 28. The drive control device 61 consists of a mounting base 62 with a cylindrical case 63 that houses a valve switching mechanism using a motor, etc., fixed to the mounting base 62. From the end of the base 62, the valve switching mechanism rotates the rotation angle in three steps of 120 degrees each. A drive shaft 64 that can be switched to protrudes. This drive shaft 64 is fitted into the shaft hole 54 at the end of the valve 51, and the left and right sides of the mounting base 62 are connected and fixed to the pedestal part 28 with bolts and nuts 65, 65. The drive control device 61 is thus housed in the space S between the bifurcated portions 10 of the radius slot 1, and the distal end of the case 63 is brought into contact with both side edges 5 of the reinforcing plate 4 to prevent sway.

By the way, to fill the hydraulic oil into the main body of the fluid-filled bush 11, remove the drain stock 73, inject the hydraulic oil, and bleed the air inside from the drain pipe 72.
After that, the drain hook 73 is screwed on to complete the process.
When the hydraulic oil is filled in, three circular holes 16 are formed in the half circumference of the outer cylinder 13 on the side where the drain pipe 72 is provided, so that air can be removed reliably.

The radius slot 1 is equipped with the above-mentioned fluid-filled bushes 11 in the bifurcated portions 10 at both ends.
The inner cylinder 12 is installed in the longitudinal direction of the vehicle body by pivotally connecting one side of the inner cylinder 12 to a support shaft on the vehicle body side and the other to a support shaft on the side of a suspension component such as an axle housing.

In the above, the drive control device 61 for the valve 51
is operated by a control unit installed in the vehicle interior, and as shown in FIG.
48, fluid-filled bush 1
The hydraulic oil in the valve hole 56 is not restricted by the valve hole 56, and the compliance characteristics become soft.

When the smaller valve hole 57 is aligned with the through holes 46 and 48, the hydraulic oil is squeezed by the valve hole 57, and the orifice effect generates a damping force, making the compliance characteristic hard.

Moreover, when the through holes 46 and 48 are closed with the valve 51,
The communication path 18 is blocked by the valve 51, and communication between both fluid chambers 0 ₁ and 0 ₂ is therefore cut off, so that the compliance characteristic becomes the stiffest.

In this way, the radius rod 1 is provided with variable damping force type fluid-filled bushes 11 at the bifurcated portions 10 at both ends thereof, and the bushes 11 protrude from the main body, and the valve 5
The drive control device 61 that switches and operates the
Since the drive control device 61 is housed in the space S between
can be effectively protected from below by the pipe end 2 and under guard plate 7, and from above by the reinforcing plate 4.

Since channel-type reinforcing plates 4 are provided vertically facing the bending pipe end 2 across the rod center line C, the bending pipe end 2 is reinforced and its strength is improved in terms of buckling countermeasures. It will be sufficient.

In addition, the pipe end 2 has the forked portion 10 bent downward.
and the upper reinforcing plate 4 joined to this, so the reinforcing plate 4 does not protrude upwards that much, especially regarding the bifurcated part 10 that is pivotally supported on the vehicle body side.
It allows for a wide clearance with the vehicle body side above.

In particular, for the fluid-filled bush 11, the valve 51 is fitted into the holding body 41 with a step difference, and after the valve 51 is assembled with the circlip 59 and assembled, the holding body 41 is inserted into the cylinder 29 of the pedestal 25 on the outer periphery of the holding cylinder 21. Since the installation is completed by simply fitting and attaching the drive control device 61 to the pedestal portion 28, assembly can be easily performed and work efficiency is improved.

In addition, as in the embodiment, the valve holder 41 and the outer cylinder 1
If the rubber tube 47 is inserted between the circular hole 17 of No. 3,
The sealing measures for this part are perfect, and the positional deviation of the holding body 41 can also be absorbed, so that assembly accuracy can be maintained. Since the outer periphery of the rubber cylinder 47 is formed to have a smaller diameter than the inner periphery of the inner cylinder 29, a sufficient gap 49 can be secured between the rubber cylinder 47 and the inner cylinder 29 as shown in FIG. Become. Therefore, a sufficient flow area can be ensured without substantially restricting the flow area of the communication passage 18 at this portion.

Furthermore, since the tip end of the inner tube 29 is also flush with the inner circumferential surface of the holding tube 21 as shown in FIG. 2, the flow passage area can be secured in this portion as well without being substantially restricted.

In the above embodiment, the valve has two valve holes, but it goes without saying that three or more valve holes may be provided.

(Effects of the invention) As described above, according to the invention, the holding cylinder of the variable damping force type fluid-filled bushing is provided with an opening facing the internal communication path, and the pedestal with the cylinder part that fits into this opening is attached to the holding cylinder. While fixed on the outer periphery, a holder having at least two valve holes rotatably incorporated in the cylindrical part of this pedestal is fitted, and the valve drive control device is attached to the pedestal. , the compliance characteristics can be variably controlled in three or more stages, and the valve can be assembled with the holder to facilitate assembly.
It offers many excellent advantages.

[Brief explanation of drawings]

Figure 1 is a partial side view of the suspension arm.
Fig. 2 is an enlarged side view showing the fluid-filled bush in longitudinal section, Figs.
They are sectional views taken along the - line and the - line. In the drawing, 1 is a radius rod, 2 is a rod end, 4 is a reinforcing plate, 7 is an under guard plate, 10 is a bifurcated part, 11 is a fluid-filled bush, 12 is an inner cylinder,
13 is an outer cylinder, 18 is a communication path, 21 is a holding cylinder, 23
25 is an opening, 25 is a pedestal, 29 is a cylinder, 31 is a rubber wall, 41 is a valve holder, 47 is a rubber tube, 51 is a valve, 56, 57 are valve holes, 61 is a drive control device, 63 is a case, 64 is a A drive shaft, 73 is a drain tank, 0 ₁ and 0 ₂ are fluid chambers, and S is a space between two forks.

Claims (1)

[Scope of utility model registration request] A plurality of fluid chambers are formed between the inner and outer cylinders by a rubber wall that connects the inner cylinder and the outer cylinder, and a holding cylinder is provided to hold the outer cylinder. A fluid-filled bushing in which a communication passage is formed to communicate between each fluid chamber, a valve is provided in the communication passage to make the area of the passage variable, and the damping force is made variable by switching and driving the valve, An opening facing the communication path is formed in the holding cylinder, and a pedestal having a cylindrical portion that fits into the opening is fixed to the outer periphery of the holding cylinder, and at least two
A variable damping force type characterized in that a valve holder that rotatably holds a valve provided with several valve holes is fitted into a cylindrical part of a pedestal, and a drive control device that rotates the valve is attached to the pedestal. Fluid-filled bush.