JP3087410B2 - Vehicle damping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for a vehicle, which generates a damping force with respect to rocking, pitching, etc. of the vehicle body, and more particularly, to a method in which a stroke between the vehicle body and wheels is relatively reduced between two wheels. The present invention relates to a swing damping device capable of effectively performing a damping force control on a roll and a pitch accompanied by a displacement.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for attenuating roll motion of a vehicle, for example, Japanese Patent Application Laid-Open No. 60-1 proposed by the present applicant has been proposed.
There is one described in Japanese Patent No. 28011. This conventional device includes a variable damping force shock absorber as a roll rigidity variable mechanism provided on each wheel and capable of changing the roll rigidity, a steering angle detector for detecting a steering angle, and a unit based on a detection signal of the detector. A steering amount calculating means for calculating a steering amount per time; a steering amount determining means for determining whether a calculated value of the calculating means is equal to or more than a predetermined value; A control means for increasing the roll rigidity of the variable damping force shock absorber of each wheel.

A device for attenuating the pitch motion of a vehicle is disclosed, for example, in Japanese Patent Application Laid-Open No. 60-64 proposed by the present applicant.
No. 011 is described. This conventional device detects the braking state of a vehicle with a brake switch or the like, determines when to start braking and when to end braking based on the detection signal, and temporarily stops the front and rear wheels at the start and end of braking, respectively. Control means for increasing at least one of the damping force and the spring constant.

Further, as an apparatus for attenuating the roll, pitch and bounce movements, there is, for example, one disclosed in Japanese Patent Application No. 2-202834 proposed by the present applicant. This conventional device is designed so that when the damping force is increased or decreased so as to suppress a specific behavior among roll, pitch and bounce, the increase or decrease of the damping force does not affect the damping force for other behaviors. A double-acting cylinder is interposed between the front, rear, left and right wheels and the vehicle body, and a communication mode between the double-acting cylinders is determined by a stroke causing a stroke change according to a detected value of lateral acceleration, longitudinal acceleration, and vertical acceleration occurring in the vehicle. The switching control is performed so that the damping force generating means generates the damping force only for the working fluid from the dynamic cylinder.

[0005]

However, in the above-mentioned conventional vehicle vibration damping device, the vehicle body vibration such as roll and pitch is simply detected based on detection values of a lateral acceleration sensor, a longitudinal acceleration sensor and the like. Since the damping force is increased so as to suppress the swing, the damping force can be generated according to the relative swing speed of the vehicle body with respect to the wheels. There is an unsolved problem that a damping force corresponding to the absolute speed of the swing cannot be generated, and a reliable damping effect cannot be exerted.

Accordingly, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and generates a damping force in accordance with the absolute speed of the swing of the vehicle body, thereby achieving ideal damping force control. It is an object of the present invention to provide a vibration damping device for a vehicle that can perform the above.

[0007]

According to a first aspect of the present invention, there is provided a vibration damping device for a vehicle, comprising: a vehicle body and a wheel between predetermined two wheels; In a vehicle vibration damping device that generates a damping force in accordance with a relative difference between strokes, a relative stroke between the two wheels is provided.
Relative rocking detection means for detecting a difference in torque or relative stroke speed, absolute rocking detecting means for detecting an absolute rocking amount or a rocking speed between the two wheel positions of the vehicle body, and the relative rocking detection based on the detected value of means and the absolute swing detection means and a damping force control means for controlling the damping force, the reduced
The damping control means includes the relative stroke difference and the absolute swing.
When the signs of the momentum coincide, or the relative stroke speed
When the sign of the difference and the absolute swing speed match,
It is characterized in that it is configured to increase the damping force .

According to another aspect of the present invention, the damping force control means includes a double-acting hydraulic cylinder separately disposed between the four wheels and the vehicle body; A pipe that connects the two cylinder chambers to each other between the cylinders; and a damping force generating means that is connected to the pipe and generates a damping force with the passage of a working fluid, the damping force generated by the damping force generating means. Is changed.

[0009]

In the vehicle vibration damping device according to the first aspect, the relative vibration detecting means detects, for example, the stroke speed between the wheel and the vehicle body between the front and rear or right and left wheels, and detects the difference between the two. detecting a relative stroke speed difference, as well as an absolute oscillating managed by an urban detecting means, for example a roll angular velocity based on a vertical acceleration detected value of the vertical acceleration sensors respectively disposed on two-wheel position of the front and rear or left and right of the vehicle body, the pitch angular velocity The absolute vertical speed of the corresponding vehicle body is detected, and the swing speed is detected from the difference between the two. The damping force control means compares the sign of the relative stroke speed difference and the sign of the absolute rocking speed, and when they match, determines that the vehicle is in the rocking state due to the roll or pitch of the vehicle body and increases the damping force to suppress the vibration. When the signs do not match, it is determined that there is no swinging of the vehicle body, and the damping force is reduced to suppress the swinging moment transmitted from the road surface to the vehicle body, thereby ensuring riding comfort.

In the vibration damping device for a vehicle according to the second aspect, two cylinder chambers of a double-acting hydraulic cylinder separately arranged between the four wheels and the vehicle body are connected to each other by pipes between the cylinders. Since a damping force generating means for generating a damping force with the passage of the working fluid is provided in this pipe, by appropriately selecting a pipe path communicating between the fluid pressure cylinders,
A single damping force generating means can effectively attenuate the swing of the vehicle body in different directions such as roll and pitch.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram showing an embodiment when the present invention is applied to a roll suppressing device. In the drawings, 2L and 2R denote left and right wheels of the vehicle, 4 denotes a wheel support member, and 6 denotes a vehicle body, respectively. A shock absorber 8 is mounted between the wheel support member 4 and the vehicle body 6 so as to be able to stroke in the axial direction, and a coil spring 10 is provided at a position corresponding to a position above or below the spring of the shock absorber 8. A lower arm 12 as a suspension link is attached between the wheel support member 4 and the vehicle body 6, and the lower arm 12 can swing about a swing axis as the wheel support member 4 moves up and down. .

Further, the vehicle of this embodiment is provided with a swing damping device 14 which constitutes a damping force control means also serving as a stabilizer, and the swing damping device 14 is provided between the left and right lower arms 12 and the vehicle body 6. Actuator 16 provided. This actuator 16 has hydraulic cylinders 22L and 22R as fluid pressure cylinders, and both hydraulic cylinders 22L and 22R are connected to first hydraulic pipes 26A and 26B.
Interconnected by

Each of the hydraulic cylinders 22L and 22R has a cylinder tube 22a and the cylinder tube 22a.
The inside is defined as two cylinder chambers U and L, and is configured as a double-acting single-rod having a slidable piston 22b and a piston rod 22c fixed to the piston 22b. Here, the hydraulic cylinders 22L, the end of the piston rod 22c of the 22R is swingably attached to the lower arm 12, the cylinder tube 2 2 a is swingably supported on the vehicle body 6, whereby the hydraulic cylinders 22L, 22
R is inserted between the left and right sprung and unsprung parts in parallel with the shock absorber 8.

The upper cylinder chamber U of the left wheel hydraulic cylinder 22L is connected to the lower cylinder chamber L of the right wheel hydraulic cylinder 22R via the first hydraulic pipe 26A. The chamber L is connected to the upper cylinder chamber U of the right-wheel-side hydraulic cylinder 22R via the first hydraulic pipe 26B to be cross-connected. Further, second hydraulic lines 28A and 28B are connected to intermediate positions of the first hydraulic lines 26A and 26B, respectively.
Free ends of the second hydraulic lines 28A and 28B are connected to a reservoir tank 29, respectively.

Further, the second hydraulic pipes 28A and 28B
In the middle of the variable stop 3 which constitutes the damping force generating means respectively
0L and 30R are inserted. These variable apertures 30
Each of L and 30R causes the plunger to move in response to the on / off of a control signal CS supplied from a controller 36 to the electromagnetic solenoid, which will be described later, and the movement causes the spool valve to move and the orifice diameter to decrease. -It is configured so that it can be changed into two stages.

Between the vehicle body 6 and the lower arm 12
Are the shock absorber 8 and the hydraulic cylinders 22L, 2
In parallel with 2R, a strike composed of a potentiometer, for example,
The stroke sensors 32L and 32R are inserted, and
From the sensors 32L and 32R, the wheels 2L and 2R and the vehicle body 6
Stroke detection value S consisting of a voltage corresponding to the relative displacement with respect to
_L,S_RIs output.

Further, at positions corresponding to the wheels 2L, 2R on the vehicle body 6, vertical acceleration sensors 34L, 34R are provided, respectively.
The vertical acceleration sensors 34L and 34R output vertical acceleration detection values Z _GL and Z _GR composed of voltages corresponding to the vertical acceleration generated in the vehicle body 6. Then, the stroke sensors 32L and 32R and the vertical acceleration sensor 34
The respective detected values of L and 34R are input to the controller 36 constituting the damping force control means. This controller 36
For example, it is configured to include a microcomputer, and detects the stroke detection values S _{L and} S _{R of the} stroke sensors 32L and 32R.
Are differentiated to calculate the relative stroke speeds V _SL, V _SR between the wheels 2L, 2R and the vehicle body 6, calculate the relative roll speed ω _A therefrom, and calculate the vertical acceleration sensors 34L, 3L.
The absolute vertical speeds V _{ZL and} V _ZR of the vehicle body 6 are calculated by integrating the vertical acceleration detection values Z _{GL and} Z _GR of the 4R, the absolute roll speed ω _B is calculated from these, the relative roll speed ω _A and the absolute roll speed The signs of ω _B are compared, and a control signal CS is output to the variable throttles 30L and 30R to make the damping force high when the signs match, and to reduce the damping force when they do not match.

Here, the dynamic diaphragm according to the configuration of the present embodiment is described.
The principle of the effect will be described. The equivalent hydraulic circuit of FIG. 2 is shown in FIG.
You. In FIG. 3, a cylinder stroke... X_l, X
_r, Stroke speed ... x_l', X_r', Rod axial force F
_l, F_r, The damping coefficients of the variable throttle valves 30L and 30R (second
Hydraulic pipes 28A, 28B) ... C_1l, C_1r, First
Equivalent damping coefficient of hydraulic pipes 26A and 26B of C ... C_2l,
C_2r, The amount of oil passing through the throttle valves 30L and 30R ... Q_1l, Q
_1r, Amount of oil passing through pipes 26A and 26B ... Q_2l, Q _2r,
Rod area A_r, Cylinder area ... A_CAnd A = A_C
-A_rIs defined.

Further, the average displacement amount x _B to the average displacement amount x _R, bouncing against roll with reference to FIG. _{4, x R = (x l} -x r) / 2, x B = (x l + x r) is calculated from / 2 in the formula, 2x _R = X _R, when the _{2x B = X B, X R} = x l -x r, X B = x l + x r ...... (1) becomes, x _l = (X _{R + X B) / 2,} x r = (X B -X R) / 2 ...... (2) is obtained.

Therefore, the aperture effect by the attenuation coefficients C _1r and C ₁₁ is obtained. The oil amounts Q _1r and Q ₁₁ are as follows: Q _1r = (A + A _r ) x _l ′ −A x _r ′ = (A + A _r / 2) X _R ′ + (A _r / 2) X _B ′ (3) Q _{1l = (A + A r) x} r '-Ax l' = - represented by _{(A + A r / 2)} X R '+ (A r / 2) X B' ...... (4). Since the pressure increase Δp _11l and Δp _1r by the throttle valves 30L and 30R are Δp ₁₁ = Q ₁₁ · C ₁₁ , Δp _1r = Q _1r · C _1r (5), the rod axial forces F _l1 and F _{r1 are obtained.} Is C _1l = C _1r = C
₁ and _{at, F l1 = ΔP 1r (A} + A r) -ΔP 1l A = {Q 1r (A + A r) -Q 1l A} C 1 ...... (6) F r1 = ΔP 1l (A + A r) -ΔP 1r A = ｛Q ₁₁ (A + A _r ) −Q _1r A｝ C ₁ (7) Accordingly, the damping force “F _l1 −F _r1 ” for the roll and the damping force “F _l1 + F _r1 ” for the bounce are expressed by F _l1 − using the above-described equations (6), (7) and (3), (4). F _r1 = (2A + A _r ) ² C ₁ X _R ′ (8) F ₁₁ + F _r1 = A _r ² C ₁ X _B ′ (9)

Similarly, the aperture effect by the attenuation coefficients C ₂₁ and C _2r is obtained. The oil amounts Q _2l , Q _2r are as follows: Q _2l = −x _r ′ (A + A _r ) (10) Q _2r = −x _l ′ (A + A _r ) (11) force becomes _{F l2 = -Q 2r C 2r (} a + a r) ...... (12) F r2 = -Q 2l C 2l (a + a r) ...... (13). Therefore, the _{C 2r = C 2l = C 2} , F l2 -F r2 = (A + A r) 2 C 2 X R '...... (14) F l2 + F r2 = (A + A r) 2 C 2 X B' ...... Obtain (15).

As a result, with respect to the damping coefficients C _11l and C _1r , according to the equations (8) and (9), when a roll with a relative displacement is applied between the two wheels, than when a bounce without a relative displacement is obtained, It can be seen that the generated damping force, that is, the throttle effect is large. Also,
Regarding the damping coefficients C _2l and C _2r , from equations (14) and (15),
Both, the average velocity X _R ', X _B' damping force can be seen to occur in response to. However, the pipe attenuation coefficients C _2l , C _2r
Is smaller than that of the throttle valve, so that the throttle effect becomes smaller.

In the above description, the roll and the bounce have been described. However, the same principle holds for the pitch and the bounce between the front and rear wheels or the pitch, the roll and the bounce of the diagonal wheel, depending on how two wheels are taken. It is. Next, the operation of this embodiment is described
6 will be described with reference to FIG.

[0024] That is, the process of FIG. 5 is executed as a timer interrupt processing for a predetermined time (e.g., 10 msec) every First stroke sensor 32L in step S1, the stroke detection value S _L of 32R, S _R and the vertical acceleration sensors 34L, 34
Vertical acceleration detection value Z _GL of R, Z _GR reads, then the stroke detected value S _L goes to step _S2, S wheel by differentiating the _R 2L, 2R and between the vehicle body 6 relative stroke speed V _SL, V _SR Is calculated.

Next, the process proceeds to step S3 to calculate the relative roll speed ω _A by performing the calculation of the following equation (16) based on the stroke speeds V _SL and V _SR . ω _A = (V _SL −V _SR ) / T _r (16) Here, _Tr is a tread. Next, step S4
Then, the vertical acceleration detection values Z _{GL and} Z _GR are integrated to calculate the absolute vertical velocities V _{ZL and} V _ZR of the vehicle body 6.

Then, the process proceeds to step S5 to calculate the absolute roll speed ω _B by performing the following equation (17) based on the absolute vertical speeds V _ZL and V _ZR . ω _B = (V _ZL −V _ZR ) / T _r (17) Then, the process proceeds to step S6, where the relative roll speed ω _A
Absolute body 6 depending on whether the sign of the roll speed omega _B coincide with positive or negative is determined whether a rolling state. This determination may, for example carried out by the relative roll velocity omega _A and absolute by multiplying the roll speed omega _B values (ω _A · ω _B) to determine whether a positive or greater than a predetermined threshold value alpha, omega _A
When ω _B ≧ α, it is determined that the vehicle body 6 is in the roll state, and the flow shifts to step S7 to control the control signal C in the ON state.
After S is output to the variable throttle valves 30L and 30R, the timer interrupt process is terminated, and the process returns to the predetermined main program.
_{When A} · ω _B <α, it is determined that the vehicle body 6 is not in the roll state, and the flow shifts to step S8 to output the control signal CS in the off state to the variable throttle valves 30L and 30R, and then ends the timer interrupt processing. And return to the main program.

Therefore, assuming that the vehicle is traveling straight on a flat good road, in this traveling state, the wheels 2L,
Since no bound or rebound occurs in the 2R, no change in the stroke of the left and right hydraulic cylinders 22L, 22R occurs, no hydraulic oil flows in the pipes 26A, 26B, 28A, 28B, and a roll occurs in the vehicle body 6. Absent. Therefore, the stroke detection values S _L, S _R of the stroke sensors 32L, 32R maintain constant values, and the vertical acceleration detection values Z _GL , Z _GR of the vertical acceleration sensors 34L, 34R maintain zero. Therefore, when the process of FIG. 5 is executed, the stroke speed V _SL calculated in step S2,
Since both V _SR are zero, the relative roll speed ω _A calculated in step S3 becomes zero, and the vertical speeds V _{ZL and} V _ZR calculated in step S4 also become zero.
Since the absolute roll speed ω _B calculated in step 5 is also zero, ω
_A · ω _B <α, and the process proceeds to step S8 to output the control signal CS in the off state to the variable throttle valves 30L and 30R. For this reason, the orifice diameters of the variable throttle valves 30L and 30R are set large, and the damping coefficient becomes a small value.

The left and right hydraulic cylinders 22L, 22R
Of the pipes 26A, 26B, 28
Since the flow of the hydraulic oil does not occur in A, 28B, the variable throttle valves 30L, 30R and the pipes 26A, 26B, 28
The damping force is not generated due to the flow path resistances of A and 28B, and the predetermined suspension characteristics with emphasis on ride comfort are maintained.

It is assumed that the vehicle body 6 bounces due to unevenness of the road surface during the straight running. At this time, the stroke detection values S _{L and} S _R of the stroke sensors 32L and 32R change at substantially the same value, and the vertical acceleration sensors 34L and 3R
Since the vertical acceleration detection values Z _{GL and} Z _{GR of the} 4R are the same and have substantially the same value, the relative roll speed ω _A and the absolute roll speed ω _B are also maintained at zero.
Maintain a small state. Therefore, if the wheels 2L and 2R both bounce due to the passage of the convex portion and the pistons 22b of the hydraulic cylinders 22L and 22R both attempt to move relative to the lower part of the vehicle body, the lower cylinder chamber L is simultaneously compressed and the upper cylinder chamber L is simultaneously compressed. The cylinder chambers U simultaneously shift to the negative pressure state. Thus, the hydraulic oil in the lower cylinder chamber L flows into the upper cylinder chamber U of the opposite cylinder through the hydraulic pipes 26A (26B), and the amount of oil corresponding to the increased capacity of the rod 22c is changed by the variable throttle valve. It flows into the reservoir tank 29 via 30L and 30R.

On the contrary, the wheels 2L, 2R
When the upper cylinder chamber U is compressed together, the hydraulic oil flows through the hydraulic pipes 26A and 26B to the lower cylinder chamber L, and at the same time, the hydraulic oil corresponding to the reduced rod volume is supplied to the reservoir tank. From 29, it is supplied to the lower cylinder chamber L via the variable throttle valves 30L, 30R.

However, the amount of oil passing through the variable throttle valves 30L and 30R when bound and rebounding as described above is much smaller than the amount of oil passing through the hydraulic pipes 26A and 26B, and the amount of oil passing through the variable throttle valves 30L and 30R is small. Since the damping coefficient of 30R is a small value, the generated damping force is a small value, and the damping force of the entire vehicle is substantially only due to the shock absorbers 8,8. For this reason, the overall damping force is small, so that even when the vehicle travels on an irregular road with bounce, it is possible to maintain a good ride comfort.

Further, if the road surface facing the left and right wheels 2L, 2R is running on a stepped road surface where, for example, the left wheel 2L side is higher than the right wheel 2R side in a straight running state on a flat good road, In the state, the stroke detection value S _L of the left wheel 2L side stroke sensor 32L decreases, the stroke detection value S _R of the right wheel 2R side does not change much, and the relative roll speed ω _A becomes a negative value. ,
Since the vehicle body 6 does not swing, the vertical acceleration sensors 34L, 34
Vertical acceleration detection value Z _GL of _R, since Z _GR maintains substantially zero, the variable throttle valve 30L and proceeds from step S6 to step S8, 30R maintains a low attenuation coefficient condition. Accordingly, the pressure in the upper cylinder chamber U of the left hydraulic cylinder 22L increases due to the decrease in the stroke on the left side.
8A and the reservoir tank 29 via the variable throttle valve 30L.
, The hydraulic pressure does not fluctuate in the right hydraulic cylinder 22R, and no lifting force acts on the vehicle body 6, so that the vehicle body 6 can maintain a horizontal state.

However, when the vehicle is traveling straight ahead,
For example, when shifting to the right turning state, the vehicle body 6
The left wheel 2L side sinks and the right wheel 2R side floats
2 (see arrow A in FIG. 2). this
Thus, when a roll occurs in the vehicle body 6, the left straw
Stroke sensor 32L stroke detection value S_LBecomes smaller,
Stroke detection value S of right stroke sensor 32R_R
Becomes larger, the relative roll calculated in the process of FIG.
Speed ω_ABecomes a negative value and the vertical acceleration sensor on the left
Vertical acceleration detection value Z_GLIs negative, and
Vertical acceleration detection value Z of right vertical acceleration sensor 34R_GR
Is a positive value, the absolute roll speed ω _BIs also a negative value
You. Therefore, the relative roll speed ω_AAnd absolute roll speed
ω_BProduct ω_A・ Ω_BIs a positive value, which is greater than the threshold α.
If the value becomes large, the process moves from step S6 to step S7.
The control signal CS in the ON state is sent to the variable throttle valve 30L,
Output to 30R. For this reason, the variable throttle valves 30L, 30
The orifice diameter of R is narrowed to a predetermined value and the damping coefficient is large.
It will be good.

At the same time, the left wheel side hydraulic cylinder 22L
Is contracted in proportion to the roll speed, and the stroke of the right wheel side hydraulic cylinder 22R tends to extend in proportion to the roll speed. Therefore, the left wheel side hydraulic cylinder 2
2L lower cylinder chamber L and right wheel side hydraulic cylinder 22R
Are simultaneously compressed, and the volumes of the upper cylinder chamber U of the left wheel side hydraulic cylinder 22L and the lower cylinder chamber L of the right wheel side hydraulic cylinder 22R are simultaneously expanded. Therefore, a large amount of hydraulic oil in the upper cylinder chamber U of the left wheel side hydraulic cylinder 22L and the lower cylinder L of the right wheel side hydraulic cylinder 22R flows into the reservoir tank 29 via the variable throttle valve 30L. Is supplied to the lower cylinder chamber L of the left wheel side hydraulic cylinder 22L and the right wheel side hydraulic cylinder 22 via the variable throttle valve 30R.
A large amount flows into the upper cylinder chamber U of R. This allows
Since the variable throttle valves 30L and 30R produce a throttle effect proportional to the amount of hydraulic oil passing therethrough, the hydraulic cylinders 22L and 22R
A large damping force is generated in proportion to the stroke speed.

On the other hand, each of the shock absorbers 8 also generates a damping force in accordance with the roll, whereby the sinking of the vehicle body is suppressed on the left wheel side, and the lifting of the vehicle body is suppressed on the right wheel side. The roll angle is suppressed to a small range. Then, a steady circular turning state, the roll amount of the vehicle body 6 becomes a constant value, by the substantially equal to zero both the relative roll velocity omega _A and the absolute roll speed omega _B, the process proceeds from step S6 to step S8 , Control signal CS
Are turned off, the variable throttle valves 30L, 30L
R returns to the low attenuation coefficient state. Therefore, in the steady circular turning state, when passing through transient road irregularities seam of the road surface or the like is thereby the stroke sensor 32L, the stroke detection value S _L of _32R, but results in a change in S _R, already in this state After the roll speed and the vehicle vertical acceleration have become zero, and the variable throttle valves 30L and 30R are in a low damping coefficient state, it is possible to absorb a thrust force from the road surface and secure a good ride comfort.

Thereafter, when the vehicle returns from the turning state to the straight traveling state, the relative roll speed ω _A becomes a positive value and the absolute roll speed ω _B
Is also a positive value, and ω _A · ω _B ≧ α. By turning on the control signal CS, the variable throttle valve 30L,
By switching 30R to the high damping coefficient state, it is possible to reliably prevent sudden swinging of the vehicle body 6.

In the case of a left turn, the above operation is the same, although the left and right are reversed. As described above, according to the embodiment, the roll moment transmitted from the road surface to the vehicle body 6 can be suppressed to a minimum, and the roll state of the vehicle body 6 is accurately detected to maximize the roll damping effect. And a great vibration damping effect can be exerted while ensuring a comfortable ride.

According to the above-described embodiment, the damping coefficients of the variable throttle valves 30L and 30R can be freely changed, for example, by increasing the roll rigidity during a sharp turn to increase the amount of right and left load movement. For this reason, the swing damping device 14 of the above embodiment is mounted on the front and rear of the vehicle, and the sharing ratio of the roll rigidity, that is, the load movement amount can be freely changed between the front and rear of the vehicle, and the sum of the cornering forces can be changed on the front and rear of the vehicle. There is an advantage that the steering characteristic during turning can be reliably controlled.

In the above embodiment, the case where the relative roll speed ω _A and the absolute roll speed ω _B are calculated has been described. However, the present invention is not limited to this, and the relative roll displacement (relative stroke difference) and the absolute roll displacement ( The roll state may be determined by calculating the absolute swing amount) and comparing these signs, and control may be performed in the same manner as in the flowchart of FIG.

In the above embodiment, the case where the relative roll speed ω _A is calculated by the relative stroke speed difference and the absolute roll speed ω _B is calculated by the vertical speed difference is not limited to this. A vehicle height sensor for detecting a rotation angle of the vehicle body 6 is provided at a support position on the vehicle body side of the lateral link, and a relative roll angle between the wheel and the vehicle body is calculated from the detected angle of the vehicle height sensor. May be directly detected by, for example, a gyro or the like, and the same damping coefficient control as described above may be performed by judging the sign of the relative roll angle and absolute roll angle or the sign of the relative roll angular velocity and absolute roll angular velocity obtained by differentiating them. Similarly, regarding the pitch angle, the relative pitch angle between the wheel and the vehicle body is calculated from the rotation angle of the longitudinal arm of the suspension, and the absolute pitch angle of the vehicle body 6 is calculated. For example directly detected by the gyro or the like, it may be performed similar damping coefficient control and the determines the sign of the relative pitch angular velocity thereof relative pitch angle and the absolute pitch angle, or these were differentiation and absolute pitch angular velocity.

Furthermore, in the above embodiment, the case where the swing damping device 14 also serving as a hydraulic stabilizer is installed on the left and right wheels is described. However, the present invention is not limited to this. Or
Two diagonal wheels (front left and rear right wheels, front right and rear left wheels) may be used. In this case, the product of the relative pitch speed based on the stroke speed difference between the front and rear wheels and the absolute pitch speed based on the vertical speed difference is equal to or larger than the threshold β. By controlling whether the variable throttle valve has a high damping coefficient and a low damping coefficient, it is possible to accurately obtain the pitch damping. In the case of a diagonal wheel, the roll damping and the pitch are accurately determined. The damping can be obtained together, and, as shown in FIG. 6, the hydraulic cylinders 22FL to 22RR may be arranged between the four wheels and the vehicle body to switch the flow path between them. Good.

That is, the front wheel-side hydraulic cylinder 22FL
And 22RR, the upper cylinder chamber U and the lower cylinder chamber L are connected by hydraulic piping 26A, 26B interposed with a 4-port, 2-position electromagnetic directional switching valve 40F, and the upper cylinders of the rear wheel side hydraulic cylinders 22RL, 22RR. Between the chamber U and the lower cylinder chamber L.
0R, and hydraulic pipes 26A, 26B interposed therebetween, and the hydraulic pipes 26A, 26B on the front wheel side and the rear wheel side are further connected to an electromagnetic directional switching valve 40C at a 4-port, 2-position hydraulic pipe 2C.
7A and 27B, and further connected to a reservoir tank 29 through hydraulic piping 28A and 28B with variable throttle valves 30L and 30R inserted into hydraulic piping 26A and 26B on the rear wheel side, respectively. Cylinder 22FL ~
Stroke sensors 32FL to 32RR in parallel with 22RR
Are provided, and vertical acceleration sensors 34FL to 34RR are provided on the vehicle body 6 side corresponding to each wheel position, and detection signals of these sensors are input to the controller 36.

As shown in FIG. 7, the controller 36 sets the flow path to the first mode when the vehicle body does not swing, and sets the flow path to the second mode when the vehicle rolls. When a pitch occurs in the vehicle body, the flow path is set to the third mode, and when a bounce occurs in the vehicle body, the flow path is set to the fourth mode. Here, the first mode is, as shown in FIG.
F, 40R and 40C are set to the normal position, the upper cylinder chamber U of the front left hydraulic cylinder 22FL, the lower cylinder chamber L of the front right hydraulic cylinder 22FR, and the rear left hydraulic cylinder 2
2RL lower cylinder chamber L and rear right hydraulic cylinder 22R
R and the upper cylinder chamber U of the front left hydraulic cylinder 22FL, the upper cylinder chamber U of the front right hydraulic cylinder 22FR, and the rear left hydraulic cylinder 2
2RL upper cylinder chamber U and rear right hydraulic cylinder 22R
The lower cylinder chamber L of R is controlled to be in a communicating state, and the variable throttle valves 30L and 30R are controlled to have a low damping coefficient to ensure a good ride comfort.

[0044] The second mode, when the left and right wheels and the vehicle body relative roll velocity omega _A and the product of the absolute roll speed omega _B of the vehicle body is equal to or larger than the threshold alpha 6 rolls, electromagnetic direction in the first mode Only the switching valve 40C is switched to the offset position, and the upper cylinder chamber U of the front left hydraulic cylinder 22FL, the lower cylinder chamber L of the front right hydraulic cylinder 22FR, the upper cylinder chamber U of the rear left hydraulic cylinder 22RL, and the rear right hydraulic cylinder 22RR The lower cylinder chamber L is communicated with the lower cylinder chamber L of the front left hydraulic cylinder 22FL, the upper cylinder chamber U of the front right hydraulic cylinder 22FR, the lower cylinder chamber L of the rear left hydraulic cylinder 22RL, and the rear right hydraulic cylinder 22RR. The upper cylinder chamber U is controlled to be in a communicating state, and the variable throttles 30L and 30R are controlled to have a high damping coefficient. Similarly, an effective damping force for suppressing the roll is generated.

Further, in the third mode, when the product of the relative pitch speed and the absolute roll speed between the front and rear wheels and the vehicle body is equal to or more than the threshold value β, the front and rear electromagnetic directions are switched in the first mode. The valves 40F and 40R are switched to the offset positions, and the upper cylinder chamber U of the front left hydraulic cylinder 22FL, the upper cylinder chamber U of the front right hydraulic cylinder 22FR, the lower cylinder chamber L of the rear left hydraulic cylinder 22RL, and the rear right hydraulic cylinder 22RR The lower cylinder chamber L is communicated, and the lower cylinder chamber L of the front left hydraulic cylinder 22FL, the lower cylinder chamber L of the front right hydraulic cylinder 22FR, the upper cylinder chamber U of the rear left hydraulic cylinder 22RL, and the rear right hydraulic cylinder 22RR are By controlling the upper cylinder chamber U to be in communication and controlling the variable throttle valves 30L and 30R to have a high damping coefficient, Tsu generates Ji suppressing effective damping force.

In the fourth mode, the stroke detection values S of all the stroke sensors 32FL to 32RR are set.
In _FL to S stroke rate based on _RR is positive (or negative), is to bounce a and vertical velocity based on the vertical acceleration detected values Z _GFL to Z _GRR the vertical acceleration sensor 34FL~34RR positive (or negative), the first In the mode 3, the electromagnetic directional control valve 40C is switched to the offset position, and the upper cylinder chamber U of the front left hydraulic cylinder 22FL, the upper cylinder chamber U of the front right hydraulic cylinder 22FR, and the rear left hydraulic cylinder 22
RL upper cylinder chamber U and rear right hydraulic cylinder 22RR
And the lower cylinder chamber L of the front left hydraulic cylinder 22FL, the lower cylinder chamber L of the front right hydraulic cylinder 22FR, and the rear left hydraulic cylinder 22
RL lower cylinder chamber L and rear right hydraulic cylinder 22RR
And the variable throttle valves 30L and 30R are controlled to a high damping coefficient to generate an effective damping force for suppressing bounce.

According to the configuration of FIG. 6, the communication state of the four-wheel hydraulic cylinders is switched by controlling the electromagnetic directional control valve, and only two variable throttle valves 30L and 30R are required. Can be simplified. Furthermore, in the above embodiment, the case where the damping coefficients of the variable throttle valves 30L and 30R are switched in two stages has been described. However, the present invention is not limited to this, and the damping coefficient is changed according to the rocking speed such as roll and pitch. The coefficient may be changed in multiple steps or steplessly.

Further, in the above-described embodiment, the case where the working oil is applied as the working fluid has been described. However, the present invention is not limited to this, and another fluid such as water or an incompressible gas is used as the working fluid. It can also be applied. Furthermore, in the above embodiment, the case where the present invention is applied to the stabilizer using the hydraulic cylinder has been described. However, the present invention is not limited to this, and the supply to the fluid pressure cylinder inserted between the wheels and the vehicle body is performed. The present invention may be applied to an active suspension that actively controls a working fluid to be activated using a pressure control valve or the like.

As described above, according to the vehicle vibration damping device of the first aspect, the relative vibration detecting means detects the relative displacement amount or the relative displacement speed between the vehicle body and the wheels of the predetermined two wheels. The relative swing amount or the relative swing speed between the vehicle body and the wheels is detected from the difference between them, and the absolute swing amount or the absolute swing speed of the vehicle body is detected by the absolute swing detection means. The damping force is controlled by the damping force control means based on the detection value of the absolute swing detection means and the relative strobing force.
When the difference between the absolute difference and the sign of the absolute swing amount match, or
Signs of the relative stroke speed difference and the absolute rocking speed
Since There were constructed so that increasing the damping force when matching, Yuradomo is transmitted from the road surface to the vehicle body - instrument the damping effect of the oscillation becomes possible to exert the maximum while minimizing the vehicle body of The effect of maximizing the damping effect on the swing can be obtained.

According to the vibration damping device for a vehicle according to the second aspect, a double-acting hydraulic cylinder in which damping force control means is individually arranged between the four wheels and the vehicle body, and each of the hydraulic cylinders The two cylinder chambers are connected to each other by pipes between the cylinders, and the pipes are provided with damping force generating means for generating a damping force as the working fluid passes. The effect is obtained that the swing in different directions such as roll and pitch can be effectively attenuated.

[Brief description of the drawings]

FIG. 1 is a functional configuration diagram showing a basic configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing one embodiment of the present invention.

FIG. 3 is an equivalent hydraulic circuit diagram of FIG. 2;

FIG. 4 is an explanatory diagram for explaining a roll of a vehicle body.

FIG. 5 is a flowchart illustrating an example of a processing procedure of a controller in the embodiment of FIG. 2;

FIG. 6 is a schematic configuration diagram showing another embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a communication state of each cylinder chamber in the embodiment of FIG. 6 for each mode.

[Explanation of symbols]

 2L, 2R, 2FL to 2RR Wheel 6 Body 14 Oscillation damping device 16 Actuator 22L, 22R, 22FL to 22RR Hydraulic cylinder 26A, 26B Hydraulic piping 27A, 27B Hydraulic piping 28A, 28B Hydraulic piping 29 Reservoir tank 30L, 30R Variable throttle valve 32L, 32R Stroke sensor 34L, 34R Vertical acceleration sensor 36 Controller 40F, 40R, 40C Electromagnetic directional switching valve

Continuation of the front page (56) References JP-A-2-95916 (JP, A) JP-A-62-289420 (JP, A) JP-A-62-12409 (JP, A) JP-A-61-278412 (JP, A) JP-A-62-152910 (JP, A) JP-A-60-64014 (JP, A) JP-A-62-143516 (JP, U) JP-A-62-78510 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) B60G 17/015 B60G 17/08

Claims (2)

(57) [Claims] 1. A swing damping device for a vehicle, which generates a damping force in accordance with a relative difference between a stroke between a vehicle body and a wheel between predetermined two wheels, a relative stroke difference or a relative stroke speed difference between the two wheels. Swing detection means for detecting the absolute swing amount or the absolute swing speed between the two wheel positions of the vehicle body, the relative swing detection means and the absolute swing detection means and a damping force control means for controlling the damping force based on the detected values, the damping force control means, the relative stroke - click difference and the
When the sign of the absolute swing amount matches, or when the relative
-When the speed difference and the sign of the absolute rocking speed match
A vehicle damping device configured to increase the damping force . 2. The damping force control means includes a double-acting hydraulic cylinder separately disposed between four wheels and a vehicle body, and a pipe for interconnecting two cylinder chambers of the hydraulic cylinder between the cylinders. And a damping force generating means communicating with the pipe and generating a damping force with the passage of the working fluid, wherein the damping force generated by the damping force generating means is changed. The vehicle damping device according to claim 1.