JPH0620645Y2 - Stabilizer spring force variable device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a device capable of varying the spring force of a stabilizer bar in a stabilizer mechanism as a roll rigidity reinforcing means in a suspension system of a vehicle, The influence of the variable spring force control on the posture of the vehicle body is minimized.

[Conventional technology]

The stabilizer in the suspension system of a vehicle is a U-shaped stabilizer bar with both ends fixed to lower arms via link rods, and the middle part of which is rotatably supported on the vehicle body. If the bars move up and down at the same time, the spring action by the bar does not occur, but when there is a phase difference between the left and right up and down motions, a constant spring force acts with the center of the bar as a torsion bar. It consists of

Therefore, the spring force of the bar acts in a direction to correct the phase difference between the vertical movements of the left and right wheels, the roll rigidity at this time is increased, the roll of the vehicle body is suppressed, and the traveling stability can be improved. .

When the roll rigidity is strengthened by such a stabilizer mechanism, the total spring constant of the suspension system increases, the natural vibration on the spring of the vehicle increases in accordance with this increase, and the undulating road surface where the left and right wheels move in opposite phases up and down. There is a risk that the sprung mass will become poor when riding, and the riding comfort will be degraded.

Therefore, as a stabilizer mechanism for preventing such a riding comfort deterioration phenomenon, an improved device has been proposed in which the vehicle body side support of the stabilizer bar is performed with the interposition of a pair of movable cylinders that operate in reverse to each other (for example, JP Sho 60-169
No. 314).

According to the improved means of this kind, when the upper chamber and the lower chamber of each piston of the pair of left and right cylinders are connected to each other with the valve interposed, the left and right wheels move up and down in opposite phases. Since the support point of the stabilizer bar is moved up and down in the direction of operation of the wheels to incline the bar, a torsion torque is not generated in the bar itself, the stabilizer is free, and the vehicle body is based on the original spring constant of the suspension system. While the ride comfort can be secured, the stabilizer function is exerted by sending pressure oil from the external hydraulic power source to these left and right cylinders and forcibly moving them up and down when necessary, such as when a vehicle body roll occurs. It is possible.

[Problems to be solved by the invention]

By the way, according to the means for moving the support point of the stabilizer bar of this kind, a pair of movable cylinders is required for the vehicle body side support for that purpose, and these left and right cylinders must be finished to have exactly the same dimensions, and If the vertical strokes of the left and right wheels are not the same, the flow rate of hydraulic oil that flows in or out of the left and right cylinders will be different, and the stabilizer bar at that time cannot be completely freed. Since the vertical movement of the entire stabilizer bar is driven, the variable inertial mass at the time of control operation is large, and even if the cylinder reaches a free state, there is a phase delay in the movement of the cylinder with respect to the movement of the wheels, In some cases, the stabilizer may adversely affect the stability of the vehicle and improve riding comfort. The land had been left behind.

On the other hand, as a cylinder locking means when the stabilizer function is exerted, it is necessary to secure a piston position at the time of locking, so that a complicated oil supply network having a dedicated hydraulic power source has to be constructed.

Therefore, the present invention is intended to solve the problems in the conventional means, and to develop a practical device for varying the stabilizer spring force so as to achieve both high running stability and improved riding comfort. .

[Means for solving problems]

In order to achieve this object, in the present invention, in a vehicle stabilizer including a stabilizer bar arranged to generate a torsion torque according to a difference between vertical movements of the left and right wheels, the one end of the stabilizer bar is movable. A cylinder is arranged so that the end coupling portion is displaceable, and a bypass groove is provided on the inner wall of the cylinder while leaving the neutral position of the piston stroke region, while the piston upper and lower chambers of the cylinder communicate with the reservoir chamber. Proposed is a spring force varying device for a stabilizer in which an operating check valve is arranged in each oil passage, and a relief valve is arranged in parallel with the check valve in the oil passage from the inner piston rod entry side of the upper and lower chambers. .

[Action]

In the device configuration according to the present invention described above, the movable cylinder is selectively switched between an operating (free) state in which the upper and lower chambers of the piston communicate with each other and an inactive (locked) state in which the communication is blocked by an external operation.

Therefore, when the cylinder is in the operating state, one movable end of the stabilizer bar, which is arranged on one of the both-end joints, follows the movement of the other restraining end. Therefore, even when the vertical movements of the left and right wheels are in opposite phases, they expand and contract within the piston stroke range of the cylinder, and both ends of the bar move in the same phase as the restraining side, resulting in torsion in the bar. It becomes a stabilizer-free state where no torque is generated.

When the cylinder is in the inoperative state, both ends of the bar move up and down integrally with the left and right wheels, so the bars are twisted by the up-and-down up-and-down movements of the left and right wheels, and the up-and-down movement of both bars is caused by the repulsive torque. The stabilizer is in a working state in which a force is applied to correct the phase difference of.

On the other hand, the reservoir chamber communicating with the piston upper and lower chambers of the movable cylinder acts so as to absorb the volume change of the cylinder chamber due to the movement of the piston rod into and out of the cylinder when the cylinder is free.

Further, the operating check valve for selecting the operation and non-operation of the cylinder, when the valve is opened by an external operation, establishes communication between the upper and lower chambers of the cylinder and with the reservoir chamber to place the cylinder in the operating state, When the operation is released, the valve is closed by the urging force, and the communication is cut off to bring the stabilizer into a working state in a cylinder inoperative state.

By the way, since the cylinder lock by the check valve operation is performed when the external operation to the valve is released, the piston position at that time is not always constant. However, when the piston stop position is other than the neutral position of the in-cylinder stroke, the inter-chamber movement of the hydraulic oil is performed through the bypass groove provided on the inner wall of the cylinder, so the piston can be moved. It is necessary to compensate for the excess or deficiency of hydraulic oil in the chamber caused by the increase or decrease of the capacity of the cylinder chamber due to the piston rod moving in and out of the cylinder.

In response to this, the operated check valve that functions as a check valve under the closure and the relief valve provided in parallel with the operated check valve function. That is, when the cylinder volume is increased to a negative pressure by increasing the volume of the cylinder volume, hydraulic oil is supplied from the reservoir chamber through the check valve, and the volume of the volume is increased to increase the pressure in the chamber to a predetermined relief. When the pressure is reached, hydraulic oil is sent to the reservoir chamber via a relief valve provided in parallel with the check valve. This allows the piston to move to its neutral position and lock.

When the communication between the upper and lower chambers due to the bypass groove is cut off at the neutral position, the pressure receiving area of the piston working portion changes from the piston rod cross-sectional area to the piston cross-sectional area, so the relief state disappears and the locked state is Reserved.

Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

〔Example〕

FIG. 1 shows the basic principle of the device of the present invention. One end of the bent arms 1a, 1a of a U-shaped stabilizer bar 1 is connected to a lower arm (not shown) via a link rod 2. The movable cylinder 3 is arranged at the lower arm coupling portion at the end of the other arm portion 1a. The bar 1 is provided with vehicle-body-side supporting portions 4 and 4 at an intermediate portion 1b thereof, and the vehicle body (not shown)
It is rotatably attached to.

The movable cylinder 3 has a piston upper chamber and a lower chamber 5a.
And 5b, and is connected to the accumulator 6 as a reservoir chamber. In addition, 7a indicates a left wheel, and 7b indicates a right wheel.

FIG. 2 is a vertical side view showing an embodiment of a movable cylinder according to the present invention, which is supported by a cylinder 9 having a mounting portion 8 on the lower arm side and a piston rod 11 having a mounting portion 10 on the bar 1. The piston 12 is movably fitted, and small holes 13a and 13b for communicating passages toward the valves 5a and 5b are opened in the peripheral wall near both ends of the cylinder 9.

That is, the opening positions of these small holes 13a and 13b are
12 is a cylinder wall that makes sliding contact immediately before reaching the extension position and immediately before reaching the bottom abutting position, and when the piston 12 reaches the position immediately before each of the positions, the small hole 13a or 13b is formed by the sliding contact wall. The chambers on the piston movement side at the respective closed positions are sealed, so that the stopper function at the time of push-cut and at the time of bottom abutment is exerted.

Furthermore, the bypass grooves 15a and 15b are left on the inner wall of the cylinder 9 leaving the neutral position 14 of the effective stroke region of the piston 12.
Is provided.

FIG. 3 is a vertical cross-sectional side view showing an embodiment of the valves 5a and 5b of the present invention. A push rod for opening a poppet 17 biased by a spring 16 against the biasing force. The push rod is provided with an operation check valve 18 having a passage port 19 to the accumulator 6 and a passage port 20 to the upper chamber or the lower chamber of the cylinder 12.
The 18 is manually operated to be pressed and released.

FIG. 4 is a diagram showing an oil supply circuit system according to the present invention, in which the piston rod 11 is arranged in the oil supply passage from the cylinder chamber on the inlet and outlet sides, and the relief valve 21 is attached to the valve 5a composed of the operation check valve. They are arranged side by side.

According to the embodiment having such a configuration, the valve 5a
When 5 and 5b are open, the upper and lower chambers of the movable cylinder 3 are in communication with each other, and the movable cylinder 3 is in a free state where its movement is not restricted within the range of the piston stroke. Accordingly, the cylinder mounted on the wheel side moves up and down, and the piston on the arm mounting side moves up and down as the stabilizer bar 1 rotates in conjunction with the up and down movement of the other left wheel 7a.

Therefore, in the valve open state, the stabilizer bar 1 interlocks with the left side wheel 7a on the restraining side of the arms 1a and 1b.
It becomes a stabilizer-free state in which the tip of the turns.

Then, in this piston-free operating state, the cylinder 3
The hydraulic oil corresponding to the change in the total volume of the cylinder upper and lower chambers that changes due to the piston rod 11 that moves in and out is absorbed by the accumulator 6.

On the other hand, when the valves 5a and 5b are closed, the upper and lower chambers of the movable cylinder 3 are isolated from each other, so that the movement of the hydraulic oil between these chambers is interrupted, and as a result, the extension side of the piston 11 and Both leftward movements are locked. Therefore, the stabilizer bar 1 and the left and right wheels are rigidly connected, and the left and right wheels 7a and 7b are vertically moved in opposite phases to generate a torsional torque in the bar 1, which results in a stabilizer action.

The oil supply circuit system shown in FIG. 4 is applied for switching between the free communication and the cutoff lock of the movable cylinder 3. That is, the valve 5a and the operating check valve and
When 5b is pressed and its push rod 18 is opened,
The piston 12 is in a free state by communicating between the piston upper and lower chambers of the cylinder 9 and the accumulator 6 communicating with each other.

When the pressure on the rod 18 is released from this state, the poppet 17 reaches the closed position due to the expanding pressure of the spring 16, and after that, the poppet 17 acts as a check valve, and the movement of the piston 12 thereafter causes a bypass provided on the inner wall of the cylinder 9. Groove 15
Regulated by a or 15b.

For example, when the volume of the cylinder chamber increases by the amount of the withdrawal of the piston rod 11 during the movement toward the neutral position 14 by the movement of the piston 12 in the extending direction, and when the chamber becomes negative pressure, it is checked. While the valve 5a as a valve is opened and hydraulic oil is supplied from the accumulator 6 to the cylinder,
When the piston 12 reaches the neutral position 14, the bypass groove 15
When b is closed and the chamber on the piston rod 11 side is sealed, the piston 12 is locked.

On the other hand, when the piston 12 moves toward the pressure side, the internal pressure of the cylinder chamber increases due to the volume of the piston rod 11 penetrating into the cylinder 9, and when the internal pressure reaches the relief pressure, excess pressure in the cylinder passes through the relief valve 21. The piston 12 moves to the neutral position 14 while feeding the hydraulic oil of No. 2 to the accumulator 6, and the piston 12 moves away from the bypass groove 15a to seal the chamber on the piston rod 11 side. Due to the change (transition from the rod cross section to the long diameter piston), the previous relief state disappears and the cylinder is locked.

[Effect of device]

As described above, according to the device of the present invention, the stabilizer spring force is variably controlled by providing the valve circuit for connecting or disconnecting the movable cylinder and the piston upper and lower chambers and the external accumulator, so that the stable running is ensured. It is possible to secure the riding comfort at the time, and by arranging the movable cylinder at one wheel side coupling portion of the stabilizer bar, it is possible to construct a mechanism with an actuator consisting of one movable cylinder, and moreover, the operating portion is the bar. Since there is only a bent arm part, the variable inertial mass of this part is relatively small and the response is excellent when the cylinder is free.Moreover, the valve circuit communicates with the operating check valve and the piston rod inlet / outlet side chamber. With the relief valve installed side by side, the volume of the chamber can be increased or decreased by moving the rod in and out while the valve is closed. While the piston can be moved to the neutral position under the action of the bypass groove provided on the inner wall of the cylinder, the cylinder can be locked always in the neutral position of the piston and the stabilizer function can be stabilized. In addition to being able to demonstrate it, the accumulator can measure the stability of the operation by absorbing the change in the cylinder chamber capacity due to the piston rod coming in and out, and the device of the present invention achieves a high level of both running stability and riding comfort. In addition to exhibiting the excellent functions possible, the entire mechanism can be constructed relatively easily, and in addition, it can be produced at low cost, which is a great advantage in practical use.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic principle of the device of the present invention, FIG. 2 is a vertical sectional side view showing an embodiment of a movable cylinder in the device of the present invention, and FIG. 3 is an embodiment of an opening / closing valve in the device of the present invention. FIG. 4 is a vertical cross-sectional side view, and FIG. 4 is a configuration diagram showing a control system in the device of the present invention. DESCRIPTION OF SYMBOLS 1 ... Stabilizer bar, 3 ... Movable cylinder, 4 ... Car body side support part, 5a, 5b ... Valve consisting of an operating check valve, 6 ... Accumulator, 7a ... Left wheel, 7b ... Right wheel, 9 ... Cylinder, 12 ... Piston, 13a, 13b ... Small holes, 14
… Neutral position, 15a, 15b… Bypass groove, 21… Relief valve.

Claims (1)

[Scope of utility model registration request] 1. A vehicle stabilizer comprising a stabilizer bar arranged to generate a torsion torque according to a difference in vertical movement of left and right wheels, wherein a movable cylinder is arranged at one end of said stabilizer bar. The end coupling portion is configured to be displaceable, and a bypass groove is provided in the cylinder inner wall while leaving the neutral position of the piston stroke region,
On the other hand, an operating check valve is arranged in each of the oil passages that communicate the piston upper and lower chambers of the cylinder with the reservoir chamber, and a relief valve is provided in the check valve in the oil passage from the inner piston rod entry side of the upper and lower chambers. A spring force varying device for a stabilizer characterized by being arranged in parallel.