JPS6328712A - Rolling rigidity control device for vehicle - Google Patents

Abstract

PURPOSE:To enable obtaining good riding quality in straight forward running and stable posture in cornering concurrently by increasing rolling rigidity when a fluid pressure and a vehicle speed have exceeds predetermined values in the subject device using said pressure for a steering power. CONSTITUTION:A vehicle speed 10 and a hydraulic pressure 11 for a power steering mechanism are inputted to ECU 20. Having detected that both of the inputted speed 10 and hydraulic pressure 11 are over predetermined values, the ECU 20 judges that cornering takes place at a speed above a predetermined level, and controls a changeover valve via rolling rigidity change means so that the rolling rigidity of each connection actuator 5 and 9 will increase. The rolling motion of a vehicle is thereby prevented. According to the aforesaid constitution, it is possible to obtain good riding quality in straight forward running and the stability of running posture in cornering concurrently.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is effective in suppressing the rolling of a vehicle when turning, and improves the roll rigidity of a vehicle that provides a good ride comfort even when traveling straight. Regarding a control device.

[Prior Art] When a vehicle turns, rolling occurs due to the action of centrifugal force. In this case, as the roll angle increases, the camber angle also changes, which increases canvas last and improves maneuverability.
This results in a decrease in stability, and therefore, it becomes necessary to perform corrective steering frequently in order to maintain the turning state. In order to suppress such rolling and improve maneuverability and stability, it may be possible to set the spring constant of the suspension high, for example. However, in this case, impactful vibrations, such as when driving on rough roads, are not absorbed, and ride comfort deteriorates. Therefore, a vehicle is provided with a stabilizer that acts as a spring and generates a restoring force only when the suspension positions of the left and right wheels are different, in order to suppress rolling. However, even if the vehicle is not rolling, for example, if one of the left and right wheels rides on a bump on the road surface, there will be a difference in the position between the left and right wheels, so the stabilizer will generate torsional elastic force and spring. As a result, ride comfort deteriorates in the same way as when the spring constant of the suspension is set high. As a countermeasure for such problems, for example, a ``vehicle stabilizer mounting device'' (Japanese Patent Application Laid-Open No. 131024/1983) has been proposed. That is, a hydraulic piston with a predetermined stroke is interposed between the arm that holds the left and right wheels and the 1-inch section at one end of the stabilizer, and the hydraulic piston is in a movable state during normal straight-ahead travel. This is a technique in which the stabilizer is not activated, but the stabilizer is activated only when turning by sensing the centrifugal force, with the residue pressure piston in a fixed state.

[Problems to be Solved by the Invention This prior art has the following problems. That is, centrifugal force is generated simultaneously with rolling of the vehicle.

Therefore, even if the stabilizer is activated when centrifugal force is detected, the vehicle is already rolling.

As described above, control based on centrifugal force delays the start time of the stabilizer, so there is a problem that sufficient restoring force cannot be obtained by the stabilizer, and rolling cannot be effectively suppressed.

Therefore, the present invention aims to solve the above problems and employs the following configuration.

[Means for Solving the Problems] That is, the gist of the present invention is, as illustrated in FIG. The roll stiffness control device for the vehicle M3 includes a pressure detection means M4 for detecting the pressure of the fluid, and a pressure detection means M4 for detecting the pressure of the fluid;
3, the roll rigidity changing means M6 of the vehicle M3, and the pressure detected by the pressure detecting means M4 are equal to or higher than a predetermined pressure, and the pressure detected by the vehicle speed detecting means M5 is The roll stiffness control piece device for a vehicle is characterized by comprising: control means M7 for increasing the roll stiffness by the roll stiffness changing means M6 when the vehicle speed exceeds a predetermined speed.

[Operation] Vehicle speed detection means M5 detects that the speed of vehicle M3 is equal to or higher than a predetermined speed, and pressure detection means M4 detects that the speed of vehicle M3 is higher than a predetermined speed, and pressure detection means M4 detects that the speed of vehicle M3 is higher than a predetermined speed.
When it is detected that the fluid pressure of No. 2 is higher than the predetermined pressure,
It can be determined that vehicle M3 starts turning at a predetermined speed or higher. Therefore, the control means M7 operates the roll stiffness changing means M6 to increase the roll stiffness in order to prevent rolling.6 Next, implementation P+ of the present invention will be described. The present invention is not limited to these, but includes various modifications without departing from the spirit thereof.

[Embodiment] FIG. 2 shows a system configuration diagram of a stabilizer control device that is an embodiment of the present invention.

The stabilizer control device includes a connecting acticoator 5 interposed between the left mounting part of the front stabilizer bar 2 and the left front lower arm 4, and the left mounting part of the rear stabilizer bar 6 and the lower arm 8 of the left wheel 7. a connecting actuator 9 interposed between the front wheel 3, which is an idler wheel,
Vehicle speed sensor 1 detects the speed of the vehicle from the rotation speed of 13
0, a pressure switch 11 in which the hydraulic pressure used in the power steering mechanism is turned on at a predetermined pressure w, and an electronic control device (hereinafter simply referred to as ECLl) 20 that controls these
It consists of Furthermore, there is a stabilizer link 15 between the right attachment part of the front stabilizer bar 2 and the lower arm 14 of the right front wheel 13, and a connection between the right attachment part of the rear stabilizer bar 6 and the right? The lower arms 17 and wheels 16 are connected to each other by stabilizer links 18.

Since the configurations of the connecting actuators 5 and 9 are similar, the connecting actuator 5 will be explained based on the 30th example. As shown in FIG. 3, the connecting actuator 5 is configured to switch the distance between the right mounting portion of the stabilizer bar 2 and the lower arm 4 from a variable state to a fixed state under the control of the EC 1120.

The connected actuator 5 includes a cylinder 33 filled with hydraulic oil, a seal member 34 that oil-tightly seals the upper opening of the cylinder 33, a piston 35 that is slidably fitted to the cylinder 33, and a piston 35 that is slidably fitted to the cylinder 33. A hydraulic circuit connecting the piston rod 36 fixed to the piston, the upper chamber 37 and lower chamber 38 of the cylinder 33 divided by the piston 35, and the boat 37a of the upper chamber 37 and the boat 38a of the lower chamber 38. 39, the hydraulic circuit 39 is provided with a switching valve 40 and an accumulator 41.

The bottom surface 42 of the cylinder 33 of the connecting actuator 5 is fixed to the lower arm 4 via a bush 43. On the other hand, the upper end of the piston rod 36 of the connecting actuator 5 is connected to the mounting portion of the stabilizer bar 2 via a bush 45.

The connected actuator 5 configured as described above operates as follows when the ECU 20 outputs a control signal for energizing or de-energizing the switching valve 40, which is a three-point/two-position solenoid valve. That is, in the case of non-excitation, the switching valve 40 is
in the position shown in the figure.

Therefore, the upper chamber 37 and lower chamber 38 of the cylinder 33 of the connecting actuator 5 are in communication, and the change in the content inside the cylinder 33 due to the sliding of the piston 35 is corrected by the accumulator 41. 35 is slidable in the directions of arrows A and B in the figure, and the distance between the mounting portion of the stabilizer bar 2 and the lower arm 4 is variable. It is in a state where no elastic force is supplied and it does not function as a stabilizer.

On the other hand, when the switching valve 40 is energized by the ECU 20, the switching valve 40 is switched to the right position shown in FIG. Therefore, the upper chamber 37 and lower chamber 3S of the cylinder 33 of the coupling actuator 5 are in a cutoff state. Therefore, the piston 35 becomes unable to slide, and the distance between the mounting portion of the stabilizer bar 2 and the lower arm 4 is fixed at a predetermined distance. Thereby, the stabilizer bar 2 is in a state where it can supply torsional elastic force to the lower arm 4, and acts as a stabilizer.

Next, the configuration of the pressure switch 11 will be explained.

FIG. 4 is a perspective view showing the configuration of a power steering mechanism provided in a vehicle to which this embodiment is applied. The power steering mechanism includes a gear housing 51, a reservoir tank 53, and a hydraulic pump 55. The gear housing 51 is configured to transmit the operation of the handle 5'7 through its own valve mechanism 59 and a rack and pinion mechanism, and to activate knuckle arms (not shown) by means of rods 61 at both ends of the rack to rotate the direction of the front wheel. has been done.

As shown in the schematic diagram of FIG. 5, the valve mechanism 59 is connected to a low-return valve 59a and a control valve shaft 59b. ! When the handle 57 is rotated to the left as shown in FIG. 5 1-A, the control valve shaft 59b first rotates, and the outer rotary valve 59a
rotate in the same direction as torque is transmitted through the torsion bar 590. However, due to the road resistance of the wheels 3 and 13, the torsion bar 59c is in a twisted state, that is,
The control valve shaft 59b is shifted to the left compared to the outer rotary valve 59a, and both rotate. Therefore, the oil from the hydraulic pump 55 indicated by the white arrow flows from the boat A of the rotary valve 59a to the boat B, and as shown in FIG. left cylinder 6
3a, and the oil in the right cylinder 63b is discharged as shown by the solid arrow, flows into the control valve shaft 591 from the boat C of the rotary valve 59F1, and returns to the reservoir tank 53. As a result, the piston 65 moves to the right due to the hydraulic pressure, and the rack 67 connected thereto also moves to the right. In this way, front wheel 3
．． Hydraulic pressure will help 13 to be turned to the left.

Similarly, as shown in FIGS. 2-A and 2-B, the handle 57
When it is turned to the right, oil flows from boat 8 to boat C and flows into the right cylinder 63b, and oil in the left cylinder 63a flows from boat B to the control valve shaft 59b and returns to the reservoir tank 53. As a result, the piston 65 moves to the left due to the hydraulic pressure, and the rack 67 also moves to the left. In this way, the hydraulic pressure helps turn the front wheels 3, 13 to the right.

When the handle 57 is in the neutral position, FIG.
As shown in 3-B, all oil flows from boat A into control valve shaft 59b and into reservoir tank 5.
3, the rack 67 does not move, so the previous @3.
13 will never be cut.

Returning to FIG. 4, the oil from the reservoir tank 53 is supplied to the hydraulic pump 55 through six pressure-resistant tubes, and the hydraulic pressure from the hydraulic pump 55 is further supplied to the valve mechanism 55 through the pressure-resistant tube 71.
9 and further returns to the reservoir tank 53 via the pressure tube 73. Among these, the pressure sensor 11 for detecting oil pressure is provided in the pressure tube 71. That is, when trying to turn the handle 57, the valve mechanism 59 turns 1 in FIG.
-A, 2-A, the oil pressure of the pressure tube 71 increases, and the initial stage of handle operation can be detected with high accuracy.

Next, as shown in FIG.
It is configured as a logic circuit centered around the PU 20a, ROM 20b, and RAM 20C, and is connected to the input/output section 20e via the common bus 20d, and receives signals from each sensor 10.11 and controls the connected actuator 5.9. do.

Next, the stabilizer control process executed by the ECU 20 will be described based on the flowchart of FIG. 7.The zero-line stabilizer control process is executed with delay at predetermined time intervals as the ECL1 20 is activated.

When the process starts, first, in step 100, the flag F is reset to 0. Then, in step 110, the vehicle speed detected by the vehicle speed sensor 10 is set to a predetermined speed 7.
It is determined whether the value is 0 or more. If the speed is not above the predetermined speed of 70, there is no need to operate the stabilizers 2 and 6 to increase the roll rigidity, and it is only necessary to focus on ride comfort, so especially 9r! ! Without further consideration, the process moves to step 120, where the state of flag F is judged, and since flag F is not set, the process moves to step 110 again.

Next, if the vehicle speed ■ is 70 or more, step 11
0, step 130 is executed and the pressure switch 11
It is determined whether or not is on. Here, if the handle 57 is not operated and the oil pressure of the power steering mechanism has not increased, the pressure switch 11 is in the OFF state, so the process returns to step 110 again based on the determination in step 120. .

Here, if the vehicle speed is also 70 or higher, the steering wheel is being operated, and the oil pressure of the power steering fitll is rising, an affirmative determination is made in steps 110 and 130, and then flag F is reset in step 140. It is determined whether the state is the same or not.

That is, if the determination is affirmative in steps 110 and 130, the determination in step 140 is positive.Then, in step 150, the solenoid of the connecting actuator 5.9 is turned on. For this reason, the upper chamber 37 and lower chamber 38 of the cylinders 33 of the coupling actuators 5 and 9 change from a communicating state to a blocked state. Therefore, the piston>'35 becomes unable to slide, and the stabilizer bars 2, 6
The distance between the mounting portion of the lower arm 4 and the lower arm 4 is fixed at a predetermined distance. Thereby, the stabilizer bar 2.6 is in a state where it can supply torsional elastic force to the lower arms 4, 8, and acts as a stabilizer.

Next, in step 160, flag F is set. After this, the process returns to step 110 again.

After this, even if an affirmative determination is made in steps 110 and 130, since flag F is set, step 14
A negative determination is made at 0, and the process of returning to step 110 is repeated.

After this, when the handle 57 is returned and the vehicle moves straight, the pressure switch 11 is turned off. In this case, a negative determination is made in step 130, and an affirmative determination is made in step 120 since the flag F is set. Then, in step 170, timer T is reset and started. Next, in step 180, it is determined whether the count value of timer T has exceeded a predetermined time TA. If the time TA has not elapsed, the device will wait. That is,
When 9 hours TA has elapsed, the communication between the upper chambers 37 and lower chambers 38 of the cylinders 33 of the connected actuators 5 and 9 is delayed by a time TA in consideration of the slowness of rolling after returning to straight travel. At 190, the solenoids of the coupling actuators 5 and 9 are turned off. Therefore, the upper chamber 37 and lower chamber 38 of the cylinder 33 of the connected actuator 5.9 are in communication, and hydraulic oil at a predetermined pressure is supplied from the accumulator 41 to the compartments 37 and 38. Therefore, the piston 35 becomes slidable, and the distance between the mounting portion of the stabilizer bar 2.6 and the lower arms 4, 8 becomes variable. As a result, the stabilizer bars 2, 6 are in a state where they do not supply torsional elastic force to the lower arms 4, 8, and do not function as stabilizers.

Next, in step 200, the flag F is reset,
The process returns to step 110 again. Thereafter, the above-described process is repeated.

Since the present embodiment is configured as described above, the stabilizer bars 2 and 6 do not work during normal straight-ahead driving or cornering at low speeds, and the ride comfort is maintained well. When cornering at such low speeds that undesirable rolling occurs, the stabilizer bars 2 and 6 come into play, providing the necessary restoring force to the vehicle and keeping the vehicle running attitude stable. Moreover, since cornering judgments are made based on the power steering's first-wheel hydraulic pressure, the initial stage of cornering can be accurately detected, and restoring force can be applied to the vehicle in a timely manner, resulting in effective attitude stability control. becomes possible. Also, the time point at which the effect of the stabilizer bars 2 and 6 is eliminated is a predetermined period of time TA.
Since it is done later, it is also possible to prevent rolling from happening again.

In the above-mentioned embodiment, the power steering mechanism corresponds to the steering W & lateral M2, the pressure switch 11 corresponds to the pressure detection means M4, the vehicle speed sensor 10 corresponds to the vehicle speed detection means M5, and is connected to the stabilizer bar 2.6. The combination of actuators 5 and 9 corresponds to roll rigidity changing means M6, and electronic control unit (ECU) 20 corresponds to control means M7.

As mentioned above, the present invention utilizes the pressure of driftwood to obtain steering force when operating the steering wheel, using the fluid pressure of the steering mechanism.
Because it is configured to detect the timing to increase roll stiffness, it is possible to accurately detect the early stages of cornering, effectively achieving both ride comfort when driving straight and stability when cornering. can.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the basic configuration of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, FIG. 3 is a configuration diagram of a connecting actuator, FIG. 4 is a configuration diagram of a power steering mechanism, and FIG. Figure 6 is an explanatory diagram of the operation of the power steering valve mechanism.
The figure shows a block diagram of an electronic control unit (ECU), and FIG. 7 shows a flowchart showing the contents of its processing. Ml... Handle M2... Steering mechanism M3... Vehicle M4... Pressure detection means M5... Vehicle speed detection means M6... Roll rigidity changing means Ml... Control means 2.6... Stabilizer bar 4.8.14.17...Lower arm 5.9...Connection actuator 10...Vehicle speed sensor 11...Pressure switch
・Ichi 15.18...Stabilizer link 20...Electronic control unit (ECU) 3...Hydraulic circuit 40...Switching valve 57...Handle 59...Valve mechanism 59a...Rotary valve

Claims (1)

[Claims] A roll stiffness control device for a vehicle equipped with a steering mechanism that obtains steering force by using fluid pressure when a steering wheel is operated, comprising: a pressure detection means for detecting the pressure of the fluid; and a pressure detection means for detecting the pressure of the fluid; a vehicle speed detecting means for detecting; a vehicle roll stiffness changing means; when the pressure detected by the pressure detecting means is a predetermined pressure or more, and the vehicle speed detected by the vehicle speed detecting means is a predetermined speed or more, A roll stiffness control device for a vehicle, comprising: control means for increasing roll stiffness by the roll stiffness changing means.