JPH0623786Y2 - Automotive rubber bushing spring characteristic adjustment device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is to adjust the spring characteristics of a rubber bush used to change the spring characteristics of a rubber bush used as a shock absorber, a trailing arm, and other attachment bushes of automobiles. It relates to the device.

[Conventional technology]

When attaching a shock absorber, a trailing arm, etc. to a vehicle body etc. of an automobile, a mounting bush is used.

A conventional example will be described with reference to FIG.
An annular liquid chamber forming member b and c is fixed to a rod a on the vehicle body, and a cylindrical member e is provided on the rod d on the vehicle axle, for example. A partition wall f is provided in the chamber, rubbers g and h are housed between the cylindrical member e and the member b, and between the cylindrical member e and the member c to form upper and lower liquid chambers i and j, The partition wall f is provided with ports k and l, and in the flow path between the ports k and l,
An adjusting part n having a throttle m at its tip is provided so as to be able to move forward and backward, and the adjusting part n is operated to reduce the flow area between the ports k and l.
It can be adjusted by. Therefore, aperture m
When the flow passage area between the ports k and l is changed by, the amount of the liquid in the upper liquid chamber i flowing into the lower liquid chamber j through the port k, the throttle m, and the port 1 when the rod a descends is adjusted, On the contrary, even when the rod a rises, the amount of liquid flowing from the lower liquid chamber j into the upper liquid chamber i via the port 1, the throttle m, and the port k is adjusted, so that the damping force when the rod a moves up and down is adjusted. It is done.

[Problems to be solved by the invention]

However, in the structure shown in FIG. 10, when an adjusting mechanism such as a sensor or an actuator for automatically adjusting the damping force according to various running conditions of the automobile is added, the adjusting mechanism is provided outside the adjusting section n. Since it will be installed, a large space is required and the mountability deteriorates.

Therefore, the present invention minimizes the mounting space of the switching mechanism for changing the fluid flow path of the rubber bush having a plurality of fluid chambers so that the spring characteristics of the rubber bush can be changed. It is an object of the present invention to provide a rubber characteristic adjusting device for a rubber bush which is not provided.

[Means for solving problems]

According to the present invention, a pin is inserted into a rubber bush, the pin divides a plurality of fluid chambers into the rubber bush, and a space in which one side is connected to an external pipe is provided inside the pin, and this space is defined as one fluid chamber. A port that communicates with a port that communicates with another fluid chamber is provided, and a spacer that isolates each port from an external pipe via an outer peripheral seal is provided in the middle of the space. A switching valve that opens and closes one of the ports and a piston facing the piping side are slidably inserted, and a rod that connects the switching valve and the piston is slidable through a seal at the center of the spacer. Further, the switching valve is urged in a direction to open the port by a spring arranged on the side opposite to the piston.

[Operation] When the switching valve and the piston housed inside the pin in the rubber bush are retracted by the spring and the respective fluid chambers are communicated with each other through the port and the space, the spring constant of the rubber bush becomes small. On the contrary, when the switching valve and piston are pushed by the fluid pressure, the fluid of the volume that penetrates the rod is introduced into each fluid chamber, and if any of the fluid chamber side ports is shut off by the switching valve, the rigidity of the rubber bush becomes high. The constant becomes large. Since the switching valve and the piston switching mechanism for performing the above-described switching are installed inside the pin in the rubber bush, the installation space as the switching mechanism can be small. In addition, the switching mechanism has a structure in which the fluid pressure is actuated, so that only the pipes need to be connected, and the switching mechanism can be realized at low cost. Since the spacer and each seal are provided in the middle of the space, the fluid of the rod intrusion volume is surely supplied to each fluid chamber, and each port and piping are isolated, and the fluid in each fluid chamber and the fluid in the piping are separated from each other. Can be different.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an example in which the spring characteristic adjusting device for a rubber bush of the present invention is used for a mounting portion of a shock absorber to a vehicle body, where 1 is a mounting plate on the vehicle body side, 2
Is a mounting eye, and 3 is a shock absorber.

The device of the present invention is used by being assembled to the mounting eye 2, and a pin 5 is horizontally passed through a rubber bush 4 incorporated in the mounting eye 2 and is fixed to the mounting plate 1 with a bolt 6 and a nut 7. Both ends of the pin 5 are fixedly supported by nut members 9 and 10 on a U-shaped bracket 8.
Fluid chambers 11 and 12 as shown in FIG. 2 are formed above and below the pin 5 of the rubber bush 4, and the pin 5 is provided with a space 13 which serves as a flow passage opening at one end in the axial direction. A port 14 is formed to connect the space 13 to the upper fluid chamber 11, and the space 13 and the lower fluid chamber 1 are formed.
A port 15 for communicating with 2 is provided. In the space 13, the switching valve 16 is housed and the spring 17 is built in, and the spring 14 always applies the elasticity of the spring 17 to the port 14.
And 15 are in communication. The switching valve 1
6, a piston 18 slidably housed in a nut member 9 is connected via a rod 19, and a head side of the piston 18 has an electromagnetic switching valve 21 in the middle and serves as a fluid pressure supply source. The connected pipe 20 is connected. The pipe 20 is further provided with an accumulator 22, a pressure regulator 23, and a fluid pressure pump 24 in the middle thereof. By switching the electromagnetic switching valve 22, fluid pressure acts on the head side of the piston 18, or fluid pressure is applied. Is discharged, which causes the switching valve 16 to move forward against the spring 17 and move to the port 14
And 15 are shut off, and the elasticity of spring 17 causes port 1
Allow 4 and 15 to switch to the open state. A spacer 25 is provided in the pin 5 in the middle of the space 13,
The spacer 25 separates the space 13 into two chambers via an O-ring 26 which is a seal on the outer peripheral side and an O-ring which is a seal on the inner peripheral side. Therefore, the spacer 25 is connected to each port 14 and 15 and piping 2
0 is isolated, the fluid in each fluid chamber 11, 12 and the fluid in the pipe 20 are separated, and each fluid chamber 11, 12 and the pipe 20 are separated according to the operating conditions.
Different fluids can be used inside.

The switching valve 16 and the piston 18 are connected by a rod 19, and the rod 19 is slidably inserted into the center of the spacer 25 via the O-ring which is the seal. 27 is an O-ring which is a seal provided on the outer circumference of the piston 18.

28 is a color, 29 is a connectein rod, 30, 3
1 is a tank and 32 is a stopper.

Now, in the state shown in FIG. 1, the connect rod 29
When is moved upward, the lower side of the rubber bush 4 is compressed. At this time, the fluid (for example, oil) in the fluid chamber 12 moves to the fluid chamber 11 via the port 15, the space 13, and the port 14. The spring constant of this rubber bush 4 is
The rubber volume is almost the same as when there is no rubber volume. Even when the connect rod 29 moves downward, the fluid in the upper fluid chamber 11 moves to the lower fluid chamber 12 via the port 14, the space 13 and the port 15, and thus the spring constant is similarly low.

When the solenoid A of the electromagnetic switching valve 21 is energized, the head side of the piston 18 communicates with the accumulator 22 and the pressure fluid of the accumulator 22 acts on the head side of the piston 18. As a result, the piston 18 is pushed against the spring 17 and the switching valve 16 advances to move the ports 14 and 1
5. Cut off communication. Therefore, the fluid movement from the fluid chambers 11 to 12 and the fluid movement from the fluid chambers 12 to 11 as in the case of the low spring constant are eliminated, and the spring constant of the rubber bush 4 becomes large. When the energization of the solenoid A is stopped after the switching, the electromagnetic switching valve 21 is in the neutral position, and the piston 18 is pushed to switch to the state where the spring constant is large. To return to the low spring constant, the solenoid B of the electromagnetic switching valve 21 may be energized. As a result, the switching valve 16 is retracted by the elastic force of the spring 17, the piston 18 is retracted, and the fluid acting on the head side of the piston 18 escapes to the tank 31.

In this way, the spring characteristics of the rubber bush 4 are made variable, and the spring constant is reduced during normal running to improve riding comfort, and under running conditions where steering stability is important, such as when the posture changes or when driving on rough roads. Increases the spring constant. This makes it possible to achieve both riding comfort and steering stability.

If the passage areas of the ports 14 and 15 are appropriately set, the dynamic spring characteristics can be set arbitrarily. Further, the maximum spring constant is obtained when the switching valve 16 completely closes the port 14, but the closing area is changed (piston 18
The spring constant can be set to an arbitrary value by specifying the lift of. The dynamic spring characteristic also includes a damping term.

FIG. 4 shows another embodiment of the present invention, in which the switching valve 16 is a poppet type and the electromagnetic switching valves 21A, 21B,
The power source 33 is of a pneumatic type, and the other configurations are the same as those in FIG. Reference numeral 34 is a relief valve, and 35 is a press switch.

Also in the embodiment shown in FIG. 4, the port 14 is in the illustrated state.
And 15 communicate with each other, the rubber bush 4 is in a soft state at a low spring constant, but the solenoid of the electromagnetic switching valve 21A is energized to cause air pressure to act on the head side of the piston 18 and the switching valve 16 to open the port 15. When closed, fluid chamber 11
The passage of the fluid between No. 12 and No. 12 is blocked, and the spring characteristics of the rubber bush 4 become great, and the rubber bush 4 becomes in a hard state. To return from the hard state to the soft state, it is possible to stop the energization of the solenoid of the electromagnetic switching valve 21A, energize the solenoid of the electromagnetic switching valve 21B, and stop the energization after a fixed time.

5 and 6 show still another embodiment of the present invention. In the embodiment shown in FIG. 4, the upper and lower fluid chambers 1 are
1 and 12 are formed in a tubular shape at the axial center of the rubber bush 4, and the rubber bush 4 is baked on the pin 5 and the outer cylinder 36, and the rubber 37 is baked to seal the outer circumference of the outer cylinder 36 of the rubber bush 4. The fluid chambers 11 and 12 are sealed.

In the embodiment shown in FIGS. 5 and 6, if the ports 14 and 15 are made to communicate with each other, the rubber bushing 4 can be used as in the embodiment shown in FIG.
The spring characteristic of the rubber bush can be made soft and the port 15 can be closed by the switching valve 16 to make the spring characteristic of the rubber bush 4 hard. However, this embodiment has an advantage that the rubber bush 4 can be manufactured at a low cost.

Further, FIG. 7 shows a further embodiment of the present invention. As a modification of the embodiment shown in FIG. 1, a switching valve is provided by a spring 17 in the normal case where no fluid pressure is applied to the head side of the piston 18. 16 is retracted to close the port 14, the rubber characteristic of the rubber bush 4 becomes a hard state, and fluid pressure is applied to the head side of the piston 18 to move the switching valve 16 forward against the spring 17, It is configured such that 14 and 15 are in communication with each other through the port 38 of the switching valve 16 so that the rubber characteristic of the rubber bush 4 is in a soft state.

In the event of failure of hydraulic piping, fastening parts, or other parts,
It is desirable to make the spring constant return to a hard value as a fail safe from the viewpoint of ensuring steering stability. However, in this embodiment, the switching valve 16 is returned by the spring 17 when pressure is not applied to the head side of the piston 18. As a result, the port 14 is closed and the spring constant of the rubber bush 4 is automatically made hard, so that there is an advantage that a large vibration can be suppressed and a bottom impact can be prevented to ensure steering stability.

FIG. 8 shows another embodiment in which the embodiment of FIG. 7 is modified, in which the switching valve is a poppet type switching valve 16 and the seat portion 39 in contact with the poppet in the space 13 is the inner peripheral surface. The cylindrical body 40, which is a spacer, is accommodated, the port 41 provided in the cylindrical body 40 and the port 14 provided in the pin 5 are communicated with each other through the groove 42, and the port 43 provided in the cylindrical body 40 is Port 15 on pin 5
Are communicated with each other through the groove 44, and the elasticity of the spring 17 normally causes the poppet to contact the seat portion 39 of the cylindrical body 40 so that the ports 14 and 15 are blocked.

Therefore, also in this embodiment, when the hydraulic pipe, the fastening portion, and other parts are broken, the ports 14 and 15 do not communicate with each other as shown in the figure, and the rubber characteristic of the rubber bush 4 is in the hard state. Become. When pressure fluid acts on the head side of the piston 18, the switching valve 16 is pushed to open the seat surface, and the port 14, groove 42, port 4
1, the space 13, the port 43, the groove 44, and the port 15 are in communication with each other, and the rubber characteristic of the rubber bush 4 is in a soft state.

The port 45 provided at the axial center of the poppet is for balancing the pressure acting on the poppet.

Further, FIG. 9 shows an example in which the device I of the present invention is applied to the attachment bush of the suspension trailing arm 46. 49 is a sub-frame.

The spring characteristics of the mounting bush of the trailing arm 46 are
It is better to lower it in order to secure the riding comfort, and it is better to increase it in order to secure the steering stability, and it is desirable to adjust it according to various running conditions. Therefore, even when it is applied to the bush for mounting the trailing arm, the spring characteristic is adjusted to be soft during general driving and to be hard during nose dive / squat.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments. For example, the nut member 9 screwed to the pin 5 has the piston 18 built therein. Needless to say, the piston 18 may be built in the pin 5 and various changes may be made without departing from the scope of the present invention.

[Effect of device]

As described above, according to the device of the present invention, the switching valve for switching the spring characteristic is provided inside the pin having the port which is fixed to the rubber bush and which communicates with different fluid chambers in the rubber bush, and the pressure fluid is supplied to the piston through the pipe. Since it operates, the mounting space of the switching mechanism can be made small, and the switching electromagnetic switching valve and the like can be installed on the spring by connecting it to the pipe, so that there is no problem of its earthquake resistance and the cost can be reduced. , Etc. can be exhibited.

Further, since the spacers and the seals separate the ports from the external pipe, the fluids in the fluid chambers and the fluids in the pipes have different usage conditions, so that different fluids can be used. Moreover, even if the piping side is damaged, the fluid in each fluid chamber can be prevented from flowing out.

Since the rod that connects the switching valve and the piston is slidably inserted in the spacer, the switching valve and the piston are surely interlocked with each other, and the movement of the switching valve can be guided to operate smoothly. Furthermore, since each fluid chamber is sealed via the spacer and the seal at the outer periphery and the center of the spacer, when the piston is pushed in, the fluid corresponding to the rod penetration volume in the space is introduced into each fluid chamber. Therefore, when the port is closed by the switching valve, the rigidity of the rubber bush is increased and the spring constant can be increased. As a result, it becomes difficult to resonate with a high frequency input, and discomfort such as chattering that occurs during high frequency vibration can be eliminated.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the device of the present invention, FIG. 2 is a sectional view taken along the line II--II of FIG. 1, and FIG. 3 is an overall view of the embodiment of FIG. 4, 5, 7, and 8 are sectional views showing other embodiments of the present invention, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5, and FIG. 9 is a book. FIG. 10 is a sectional view showing a conventional example in which the device of the invention is applied to a mounting bush of a trailing arm. 1 ... Mounting plate, 2 ... Mounting eye, 3 ... Shock absorber, 4 ... Rubber bush, 5 ... Pin, 9,10 ...
… Nut member, 11,12 …… Fluid chamber, 13 …… Space,
14, 15 ... Port, 16 ... Switching valve, 17 ...
Spring, 18 ... Piston, 20 ... Piping 21,
21A, 21B …… Solenoid switching valve, 25 …… Spacer, 26 ……
O-ring as seal, 40 ... Cylindrical body as spacer.

Claims (1)

[Scope of utility model registration request] 1. A pin is inserted into a rubber bush, the pin defines a plurality of fluid chambers in the rubber bush, and a space in which one side is connected to an external pipe is provided inside the pin, and this space is one fluid chamber. A port that communicates with the other fluid chamber, and a spacer that isolates each port from the external pipe via an outer peripheral seal is provided in the space in the space. Is a switching valve that opens and closes one of the ports, and a piston facing the pipe side is slidably inserted, and a rod that connects the switching valve and the piston slides through the center of the spacer through a seal. A rubber characteristic adjusting device for a rubber bush for an automobile, wherein the switching valve is freely pierced, and further, the switching valve is urged in a direction of opening the port by a spring arranged on the side opposite to the piston.