JPH0717140B2 - Stabilizer spring constant variable device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement in a spring constant varying device for a stabilizer.

[Conventional technology]

The stabilizer mechanism in the suspension system of a vehicle enhances the rigidity of the vehicle with respect to rolls and enhances the running stability of the vehicle.However, the use of the above-mentioned stabilizer increases the overall spring constant of the suspension system. This may deteriorate the riding comfort of the vehicle.

Therefore, the applicant of the present application has proposed as shown in FIG. 6 as a means for preventing the deterioration of riding comfort as described above.

That is, assuming that the movable cylinder 3 is disposed between one end of the stabilizer and the lower arm, the upper and lower chambers in the cylinder body 9 defined by the piston 12 in the cylinder body 9 constituting the movable cylinder 3 are arranged. Operate check valves 5a and 5b are provided in the respective oil passages that connect A and B to the accumulator 6 that is a reservoir chamber. The operate check valves that allow the above-mentioned accumulator 6 and the lower chamber B to communicate with each other are provided. The relief valve Vo is arranged in parallel in 5b, and the bypass grooves 15a and 15b are formed in the inner wall of the cylinder body 9 while leaving the neutral position of the piston stroke region in the cylinder body 9.

Therefore, according to the above-mentioned applicant's proposal, if the operating check valves 5a and 5b are released by the pilot operation, the movable cylinder 3 is freely expanded and contracted, that is, the torsion torque of the stabilizer is applied to the lower arm. When the vehicle travels on a sloping road surface, it is possible to prevent the vibration on the spring of the vehicle from being increased and the riding comfort of the vehicle to be deteriorated, and also to operate the operation check valves 5a and 5b for pilot operation. If a so-called check valve that allows only one-way flow by being released is in a locking state in which expansion and contraction of the movable cylinder 3 is stopped, the torsional torque of the stabilizer is transmitted to the lower arm, and when traveling on a flat road. The roll of the vehicle can be effectively prevented.

The movable cylinder 3 is locked when the piston 12
Even when the cylinder is on the lower chamber B side in the cylinder body 9, the bypass groove 15 formed in the inner wall of the cylinder body 9
Inflow of oil from the upper chamber A side and inflow of insufficient oil from the accumulator 6 into the lower chamber B via b, the piston 12 is returned to the neutral position of the piston stroke range, Further, even if the lock state is introduced when the piston 12 is on the upper chamber A side of the cylinder body 9, the lower chamber B side is introduced into the A chamber through the bypass groove 15a formed in the inner wall of the cylinder body 9. Oil inflow and Lily valve Vo
By the operation of, the piston 12 is returned to the neutral position of the piston stroke region.

That is, when the movable cylinder 3 is locked, the movable cylinder 3
The locking state is brought about in the so-called neutral position, and the posture of the vehicle is stabilized.

[Problems to be solved by the invention]

However, in the above-mentioned proposal, there is a disadvantage that the locked state of the movable cylinder 3 is brought to a completely neutral position in the piston stroke region without the piston 12 being positioned.

That is, when the piston 12 is in a position other than the neutral position of the piston stroke region, if the lock state is brought about by releasing the pilot operation to the operate check valves 5a and 5b,
When the piston 12 is on the lower chamber B side, the bypass groove 15b is used to return to the vicinity of the neutral position, and the lower chamber B side becomes a negative pressure, thereby operating the check valve 5b.
Even if the extension load is small, it can be expected to easily return to the complete neutral position due to the inflow of oil through the piston 12.
When the lock state occurs when the valve is on the upper chamber A side, after the return to the vicinity of the neutral position by using the bypass groove 15a described above, a complete neutral state is obtained unless a large pressure load acts and the relief valve Vo operates. Returning to the position cannot be expected, and the locked state is maintained in the incomplete neutral position.

As a result, in the spring constant varying device of the stabilizer shown in FIG. 6, when the movable cylinder 3 is locked, the locking state may not be brought about at the completely neutral position, and the level difference between the left and right sides on the vehicle body side may not occur. Occurs, and the posture of the vehicle becomes unstable.

Therefore, in view of the above-mentioned circumstances, it is a first object of the present invention to newly provide a spring constant varying device for a stabilizer in which the posture of the vehicle does not become unstable when the movable cylinder is locked. At the same time, a new stabilizer spring constant variable device is provided, in which two operating check valves are opened by a single pilot operation and by a small pilot operating force, and the neutral position of the movable cylinder is quickly returned. Second to do
Is the purpose of.

[Means for solving problems]

In order to solve the above-mentioned problems, the structure of the spring constant varying device of the stabilizer according to the present invention is configured such that the piston in the cylinder body that constitutes the movable cylinder is urged from both directions by a spring arranged in the cylinder body. Each of the oil passages that connect the upper and lower chambers that are partitioned to the reservoir chamber is provided with an operating check valve that is opened by one pilot operation, and one of the operating check valves is opened. The operating check valve is formed so as to be opened before the other operating check valve at the time of operating the pilot, and a reservoir chamber is formed on the inner wall of the cylinder body at the neutral position of the piston stroke region in the cylinder body. It is characterized in that an oil hole of a communicating oil passage is formed.

Each operating check valve is provided with a push rod and a poppet opposed to the push rod that move forward during the pilot operation, and one of the push rods is formed to be longer than the other push rod. It is a thing.

[Action]

When the movable cylinder is in an expandable / contractible state, the torsional torque in the stabilizer is not transmitted to the lower arm side, and the so-called stabilizer-free state is reached.When the movable cylinder is in the locked state, the torsional torque in the stabilizer is transmitted to the lower arm side. As a result, the rigidity of the vehicle with respect to the roll is increased.

Further, when the movable cylinder is locked, even if the piston in the cylinder body is not in the neutral position, the oil flows into the reservoir chamber through the oil hole formed in the inner wall of the cylinder body so as to correspond to the neutral position in the piston stroke range. Therefore, in cooperation with the urging force of the spring, the piston can be quickly returned to the complete neutral position, and at the time of the return of the piston to the complete neutral position, the oil hole is formed on the outer circumference of the piston. It will be closed and the complete locking of the movable cylinder will result.

When the operating check valves are opened, either one of the operating check valves is opened first, and then the other operating check valve is opened, so that the pilot operating force when opening both operating check valves is small. You're done.

〔Example〕

 Hereinafter, the present invention will be described based on the illustrated embodiments.

FIG. 1 shows an embodiment of use of the spring constant varying device for a stabilizer according to the present invention, in which the curved arm portions 1a, 1a of the stabilizer 1 formed in a substantially U-shape.
Connect one end to a lower arm (not shown) and link rod 2
And the movable cylinder 3 is arranged at the lower arm connecting portion at the end of the other arm portion 1a. The stabilizer 1 has a vehicle-body-side support portion disposed in the intermediate portion 1b.
It is rotatably attached to a vehicle body (not shown) via 4,4.

The movable cylinder 3 allows the upper chamber A and the lower chamber B thereof to communicate with each other via the operation check valves 5a and 5b, and the upper and lower chambers A and B communicate with the accumulator 6 serving as a reservoir chamber, respectively. I'm trying to make it happen.

The inside of the movable cylinder 3 is communicated with the accumulator 6 by another oil passage. Further, in FIG. 1, 7a indicates a right wheel, and 7b indicates a left wheel.

The movable cylinder 3 itself will be briefly described. As shown in FIG. 2, a piston rod 11 having a mounting portion 10 to the stabilizer 1 is continuously provided in a cylinder body 9 having a mounting portion 8 to the lower arm side. A piston 12 is slidably provided, and the piston 12 divides the inside of the cylinder body 9 into an upper chamber A and a lower chamber B.

A small hole is formed on the inner wall of the cylinder body 9 near both ends.
13a and 13b are opened, and oil passages L ₁ and L _{2 are} connected to the small holes 13a and 13b, respectively.

The open positions of the small holes 13a and 13b are the inner walls of the cylinder body 9 which the outer circumference of the piston 12 comes into sliding contact with just before the piston 12 reaches the fully extended position and immediately before reaching the bottomed position. , The outer circumference of the piston 12 is the small hole
This is the position where each of 13a and 13b will be closed.

Then, when the piston 12 closes the small holes 13a, 13b, this causes a so-called oil lock state, which prevents the above-mentioned extension and bottoming.

Further, an oil hole 15 is provided on the inner wall of the cylinder body 9 at the neutral position 14 of the effective stroke region of the piston 12. When the piston 12 is located on either the upper chamber A side or the lower chamber B side of the cylinder body 9, the oil hole 15 is formed between the cylinder body 9 and the accumulator 6 serving as the reservoir chamber. An oil passage L ₃ that allows communication is formed as an opening in the cylinder body 9.

The operate check valves 5a and 5b are connected to the oil passages.
It is arranged in L ₁ and L ₂ , and there is no special valve in the oil passage L ₃ .

Furthermore, a pair of springs 16a and 16b are arranged in the cylinder body 9, and the pair of springs 16a and 16b are provided.
The a and 16b are configured to urge the piston 12 from both directions. The pair of springs 16a, 16b is formed so as to be brought into balance when the piston 12 is at the central position 14.

Therefore, when the operating check valves 5a and 5b are opened and the upper and lower chambers A and B are in communication with each other, the piston 12 is moved by the load acting on the cylinder body 9 or the piston rod 11. Either spring 16
By contracting a or 16b and moving in the cylinder body 9, the movable cylinder 3 can be expanded or contracted.

Each operating check valve 5a, 5b is opened by one pilot operation to allow so-called bidirectional flow, but when released, it becomes a so-called check valve and allows only one-way flow.

Further, in this embodiment, the cylinder body 9 has stoppers 17a, which effectively prevent so-called full extension and bottoming.
17b is the upper end surface side of the piston 12 and the cylinder body 9
Are disposed on the inner bottom surface side of each.

According to the present embodiment having such a configuration, when the operating check valves 5a and 5b are in the open state, the movable cylinder 3 has its upper and lower chambers A and B in communication with each other, and the effective stroke of the piston 12 is It is in a so-called free state where its movement is not restricted within the range.

Therefore, the cylinder body 9 mounted on the wheel side moves up and down in accordance with the up and down movement of the left wheel 7b of the running vehicle, and
As the stabilizer 1 rotates in conjunction with the vertical movement of the other right wheel 7a, the piston 12 on the arm 1a mounting side moves up and down.

Therefore, when the operate check valves 5a and 5b are open, the stabilizer 1 is in a so-called stabilizer-free state in which the tip of the arm 1a pivots in conjunction with the right wheel 7a on the restraint side.

Under the piston-free operating condition, the operating oil that is insufficient in the movable cylinder 3 is replenished from the accumulator 6 that is a reservoir chamber, and conversely, the operating oil that remains in the movable cylinder 3 is absorbed by the accumulator 6.

On the other hand, when the operate check valves 5a and 5b are so-called check valves, the upper and lower chambers A and B in the movable cylinder 3 are isolated from each other, so that the movement of the hydraulic oil between these chambers A and B is interrupted. As a result, the expansion side and the compression side direction movement of the piston 12 are both locked.

Therefore, the stabilizer 1 and the left and right wheels are rigidly connected, and a twisting torque is generated in the stabilizer 1 by the up-and-down movement of the right wheel 7a and the left wheel 7b in opposite phases, which is a so-called stabilizer action state. Becomes

When each of the above-described operate check valves 5a, 5b functions as a mere check valve due to the release of the pilot operation, the movement of the piston 12 in the cylinder body 9 thereafter is performed at the center position of the cylinder body 9. It is controlled by the oil hole 15 provided in the inner wall of 14.

That is, for example, when the piston 12 is on the lower chamber B side,
As the piston rod 11 that also receives the repulsive force of the spring 16b withdraws from the cylinder body 9, the hydraulic oil on the upper chamber A side is absorbed by the accumulator 6 serving as a reservoir chamber through the oil hole 15 and the lower chamber Insufficient hydraulic oil in B will be replenished from the accumulator 6 via the operating check valve 5b, and when the piston 12 reaches the neutral position 14 of the piston stroke range, the outer circumference of the piston 12 becomes The oil hole 15 will be closed, and the upper chamber A
The oil lock state is introduced into the inside, and the further movement of the piston 12 is blocked, so that the movable cylinder 3 is blocked from expanding and contracting.

Even when the piston 12 is on the side of the upper chamber A, a negative pressure is generated by the movement of the piston 12 which receives the repulsive force of the spring 16a, and the negative pressure is generated in the upper chamber A through the operate check valve 5a. When the hydraulic oil from the bottom chamber B is replenished and the hydraulic oil in the lower chamber B is absorbed into the accumulator 6 through the oil hole 15, the piston 12 reaches the neutral position 14 of the piston stroke range. , The outer periphery of the piston 12 will close the oil hole 15,
The oil lock state is brought into the lower chamber B, and the piston
Further movement of 12 is blocked, and the movable cylinder 3 is locked to prevent expansion and contraction.

When the movable cylinder 3 is locked in the completely neutral position as described above, the arm 1a of the stabilizer 1 and the lower arm are connected in a so-called rigid state.

Further, according to the present embodiment, the operating check valves 5a and 5b are
Is open, even if the movable cylinder 3 expands and contracts with a large stroke, both ends of the cylinder body 9 are in a so-called oil-locked state.
It is possible to avoid the risk of full extension and bottoming out, and even when the stroke may exceed the extensional limit and bottoming limit, the stoppers 17a, 17b can be used to prevent the extension and bottoming out. It can be prevented in advance.

FIGS. 3 to 5 show specific examples of the device of the present invention, which will be described in detail below.

As shown in FIG. 3, the spring constant varying device for the stabilizer according to the present invention is integrally formed in an appropriate housing H and has a so-called compact form. .

That is, in the housing H, the movable cylinder 3, the two operate check valves 5a and 5b, the accumulator 6 which is a reservoir chamber, the upper chamber A and the lower chamber B in the movable cylinder 3, and the accumulator 6 are communicated with each other. Oil passage
It is provided with L ₁ and L ₂ and an oil passage L ₃ which allows the inside of the movable cylinder 3 and the accumulator 6 to communicate with each other. Then, a part of the housing H is projected to form the mounting portion 8 on the lower arm side of the movable cylinder 3.

A piston 12 is slidably accommodated in a cylinder body 9 formed in a cylindrical shape having a bottom in a part of the housing H, and the piston 12 is arranged in the cylinder body 9 to form an upper chamber A and a lower chamber. It is divided into B and. The piston rod 11, which connects the piston 12 to the lower end thereof by using the piston nut 12a, projects the upper end thereof to the outside of the upper end side of the cylinder body 9, and the projecting end is provided with a mounting portion 10 to the stabilizer 1. Have

It is assumed that the upper end side of the cylinder body 9 is closed by mounting the cap member 18, and the piston rod 11 penetrates the shaft core portion of the cap member 18. And
An oil seal 18a and a bearing 18b are provided on the inner peripheral side of the cap member 18, and the inner peripheral surfaces of the oil seal 18a and the bearing 18b are in sliding contact with the outer peripheral surface of the piston rod 11. An O-ring 18c is provided on the outer peripheral side of the cap member 18.

A stopper 17b is provided on the inner bottom surface of the cylinder body 9, and a stopper 17b is provided on the upper end surface of the piston 12.
It is assumed that a is provided and the stoppers 17a and 17b act as stroke restricting means when the piston 12 slides in the cylinder body 9 with a large stroke.

A pair of springs 16a, 16b for positioning the piston 12 at the neutral position 14 of the piston stroke region in the cylinder body 9 are housed in the cylinder body 9. 16b functions to urge the piston 12 from both directions. In addition,
In this embodiment, the pair of springs 16a and 16b are
Is a so-called double structure,
It has different springs 16c and 16d inside each.

Oil passages L ₁ , L ₂ and L ₃ are bored in the housing H. The oil passage L ₁ slides to a position just before the piston 12 is fully extended in the cylinder body 9. The outer circumference of the piston 12 is positioned and drilled so that its opening is closed when
The oil passage L ₂ is positioned and drilled so that the opening is closed by the outer circumference of the piston 12 when the piston 12 slides to the position just before bottoming in the cylinder body 9. It is set up.

Then, in the oil passage L ₃ , the piston 12 is connected to the cylinder body 9
The oil hole 15 when it is in the neutral position 14
The outer circumference of 12 is positioned and drilled so as to close it.

At the center of the outer circumference of the piston 12, a piston ring 12c urged by a back-up ring 12b is interposed, and the piston ring 12c has openings of the oil passages L ₁ and L _{2 and} an oil hole 15. It is supposed to be blocked.

Separate operating check valves 5a and 5b are provided at intermediate positions between the oil passages L ₁ and L ₂ . The respective operation check valves 5a and 5b are formed in a so-called poppet valve type as shown in FIG.

That is, the sleeve bodies 19a and 19b are disposed in the housing H, and the poppets 20a and 20b are housed in the sleeve bodies 19a and 19b so as to be vertically movable.
When 0a, 20b is rising, the communication between the upstream side and the downstream side of the relevant poppet 20a, 20b is cut off, and the poppet 20a, 20b is closed.
It is supposed that the upstream side and the downstream side of the relevant poppets 20a, 20b can be communicated with each other when the vehicle is descending.

Incidentally, the poppets 20a, 20b are the sleeve bodies 19a, 19b.
In order to fix the inside of the housing H, the upper ends of the springs 22a and 22b whose lower ends are engaged with the upper surfaces of the screwed cap members 21a and 21b are urged in the upward direction.

Furthermore, an annular groove is formed on the outer peripheral side of the sleeve bodies 19a, 19b, and the sleeve bodies 19a, 19'b are inserted through oil holes 19'u, 19'b formed in the sleeve bodies 19a, 19b. While communicating with the inner peripheral side of 19b, the annular groove is formed in the oil passage.
It is connected to L ₁ and L ₂ , respectively.

The tip rod portions 23 ', 23'b of the push rods 23a, 23b are adjacent to the poppets 20a, 20b. The push rods 23a, 23b are, in this embodiment, an artificial force F such as a tensile force. Is formed as a pilot operating force so as to advance, that is, descend in the drawing.

That is, the tip rod portions 23'a, 23'b are connected to the poppets 20a, 20 '.
The housings 23a and 23b to which b is adjacent are housings H
The springs 26a, 26 are slidably accommodated in the cap members 25a, 25b screwed to the
It is said that it is urged in the upward direction by b.

Angle members 27a and 27b are fixed to the upper ends of the push rods 23a and 23b, respectively.
7a and 27b are integrated by a connecting rod 28 so as to move up and down at the same time.

Further, a bracket 29 is connected to the connecting rod 28, and a tip of an operation lever 31 is connected to a pin 30 inserted in the bracket 29.

Also, as shown in FIG. 5, the operating lever 31 is pinned to a bracket 32 attached to the housing H.
It is supported by 33, and is connected to a connecting tool 35 via a pin 34 which is inserted at its rear end.

Further, a tension member 36 such as a wire is connected to the connecting member 35, and the rear end of the operation lever 31 can be raised by the action of the tensile force on the tension member 36.

Therefore, in the operating check valves 5a and 5b, the poppets 19a and 19b are always lowered by the push rods 23a and 23b which are moved forward by the action of the artificial force F which is a pilot operating force.
With the release of the artificial force F, the push rods 23a and 23b are retracted to raise the poppets 20a and 20b, and the oil passages L ₁ and L ₂ function as a check valve that serves as a one-way passage. .

By the way, in the present invention, the push rods 23a, 23
It is assumed that one of b is formed longer than the other, and the purpose is that the pilot operating force is initially used only for opening one operating check valve, and the operating check After the valve is opened, another one of the operation check valves is opened.

As a result, the pilot operating force required to open only one operate check valve is extremely small compared to the pilot operating force required to open the two operate check valves 5a and 5b at the same time. In the present invention, the two operating check valves 5a and 5b can be opened with a small pilot operating force.

Therefore, in the present invention, only the lengths of the tip rod portions 23'a, 23'b of the push rods 23a, 23b are different, and the overall lengths of the push rods 23a, 23b are different. In the drawing, the right side operation check valve 5b is formed to be longer than the left operation check valve 5a.

An accumulator 6 is disposed in the housing H as shown in FIGS. 3 and 4, and the accumulator 6 defines an oil chamber 37 and an air chamber 38 in the housing H. So that it has a rubber film 39,
The outer edge of the rubber film 39 is fixed by a cap member 40 screwed to the housing H so as to isolate the air chamber 38 from the outside.

Then, the oil chamber 37 is provided with the operate check valves 5a, 5
It is formed so as to communicate with the oil passages L ₁ and L ₂ via b, and also communicates with the oil passage L ₃ . Further, in the present embodiment, the air chamber 38 is communicated with the outside through an opening 40a formed in the cap member 40, and is set to have a so-called atmospheric pressure.

In the embodiment described above, push rods 23a, 23b are
Although it is said that the pilot operation is performed by the artificial force F,
Instead of this, it is also possible to use a pilot using hydraulic pressure, which uses a hydraulic pressure source for the power steering mechanism of the vehicle as a pilot hydraulic pressure source.

〔The invention's effect〕

As described above, according to the present invention, the upper and lower chambers in the movable cylinder are communicated with each other through the oil passages, are communicated with the accumulator, and the operating check valves are arranged in the respective oil passages. Therefore, the spring constant of the stabilizer can be varied only by operating the valve to the operate check valve, and the vehicle attitude can be set according to the traveling road surface condition of the vehicle.

At this time, according to the present invention, not only the two operating check valves are opened by one pilot operation, but also the pilot operating force can be made small,
So-called miniaturization is possible, and there is an advantage that it does not require a large installation space on the vehicle.

Further, according to the present invention, when the locked state of the movable cylinder is brought, the locked state of the movable cylinder is always brought promptly at the completely neutral position, and the posture of the vehicle can be quickly stabilized. Become.

Further, according to the present invention, the so-called compactness of the entire apparatus can be realized, and therefore, there is an advantage that the operation of the vehicle does not require many hours of work, and the use of the relief valve is eliminated. Therefore, there is also an advantage that cost reduction can be expected.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a spring constant varying device for a stabilizer according to the present invention, and FIG. 3 is a concrete example of a spring constant varying device for a stabilizer according to the present invention. FIG. 4 is a cross-sectional view showing a practical embodiment.
A sectional view taken along line IV-IV in the drawing, and FIG. 5 is a line V in FIG.
6 is a circuit diagram showing a conventional example similar to FIG. 1 ... Stabilizer, 3 ... Movable cylinder, 4 ... Car body side support part, 5a, 5b ... Operate check valve, 6 ...
Aki mullator, 7a ... right wheel, 7b ... left wheel,
9 ... Cylinder body, 12 ... Piston, 13a, 13b ... Small hole, 14 ... Neutral position, 15 ... Oil hole, 16a, 16b, 26a, 26b ...
… Spring, 20a, 20b …… Poppet, 23a, 23b… Pushrod, A… Upper chamber, B… Lower chamber, F …… Artificial force, L ₁ ,
L ₂ , L ₃ ... Oil passage.

Claims (3)

[Claims] 1. A spring constant of a stabilizer in which a movable cylinder is arranged between a lower arm and one end of a stabilizer arranged to generate a torsion torque according to a vertical movement difference between left and right wheels in a vehicle. In the variable device,
One piston operation is performed in each oil passage that communicates the upper and lower chambers defined in the cylinder body with the reservoir chamber by the pistons urged from both directions by springs arranged in the cylinder body forming the movable cylinder. Each of the two operation check valves is opened so that one of the two operation check valves is opened prior to the other operation check valve when the pilot is operated. And an oil hole of an oil passage communicating with the reservoir chamber is formed in the inner wall of the cylinder body at the neutral position of the piston stroke region in the cylinder body. . 2. Each operating check valve has a push rod that advances when a pilot is operated and a poppet that faces the push rod, and one of the push rods is formed to be longer than the other push rod. A spring constant varying device for a stabilizer according to claim 1. 3. A spring constant varying device for a stabilizer according to claim 1, wherein the pilot operation is allowed by utilizing an artificial force such as a pulling force.