JPS61155011A - Electronically controlled suspension device - Google Patents

Abstract

PURPOSE:To reduce the swing of an automatic drive vehicle in the longitudinal direction of the vehicle, by providing such an arangement that when a select lever is shifted, the control of attitude of the vehicle is carried out by a predetermined time after an elapse of delay time which is determined in accordance with the position of the lever. CONSTITUTION:A rear suspension unit RS1, 2 (which is similar to the front suspension unit) is integrally incorporated therein with a shock absorber 1 and a main air spring chamber 3 as a vehicle level adjusting means so that the charge and discharge of fluid to and from the main air spring chamber 3 is controlled to adjust the level of the vehicle for every wheel. In this arrangement, a control unit 37 which opens and closes solenoid valves 26, 27 to control the charge and discharge of compressed air is provided with a first memory means for storing therein a delay time for initiation of attitude control in accordance with the output of an A/T shift switch 49 and a second memory means for storing therein the time of attitude control in accordance with the shift condition. Further, upon change of the shift the vehicle level adjusting device carry out the attitude control by a predetermined time after an elapse of the above-mentioned attitude control time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electronically controlled suspension device that reduces longitudinal shaking of a vehicle body that occurs when a selector lever is changed in an automatic vehicle.

[Technical background of the invention and its problems] In an automatic car, when the selector lever is moved from the neutral (N) position to the drive (D) position with the handle brake pulled, the car attempts to move forward. However, because the brakes are applied, the rear of the car lowers, making the ride uncomfortable. On the other hand, when the selector lever is moved from drive (D) to neutral (N>), there is a drawback that the rear of the vehicle rises and the ride is uncomfortable.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide an electronically controlled suspension device that reduces the longitudinal shaking of the vehicle body that occurs when the selector lever is changed in an automatic vehicle. Our goal is to provide the following.

[Summary of the Invention] A suspension unit provided for each wheel and having a fluid spring chamber; a vehicle height adjustment means for adjusting the vehicle height of each wheel by controlling supply and discharge of fluid to the fluid springs; a first memory means for storing a delay time for starting attitude control corresponding to a change state of the position of the selector lever; a second memory means for storing a time for attitude control corresponding to the change state; The electronically controlled suspension device comprises means for controlling the attitude by the vehicle height adjusting means for the attitude control time after the delay time when the vehicle height is adjusted.

[Embodiment of the Invention] An electronically controlled suspension device according to an embodiment of the present invention will be described below with reference to the drawings.

In Figure 1, air suspension unit F81
, FS2. Since the R8I and R82 each have almost the same structure, the air suspension unit will be explained below using the symbol S, unless the front and rear suspension units are explained separately. Only the parts necessary for control will be illustrated and explained.

That is, the air suspension unit S incorporates a shock absorber 1, and this shock absorber 1 includes a cylinder attached to the front or rear wheel side and a piston slidably inserted into the cylinder. As the cylinder moves up and down relative to the piston rod 2 in accordance with the up and down movement of the wheel, shock can be effectively absorbed and the damping force changes in accordance with the stroke of the wheel.

Incidentally, a main air spring 3 which also serves as a vehicle height adjustment means chamber is disposed coaxially with the piston rod 2 at the upper part of the shock absorber 1, and a bellows 4 is provided in a part of the main air spring 3. Since air is supplied and discharged from the main air spring to the main air spring 3 through the passage 2a provided in the piston rod 2, the piston rod can be moved up and down.

Further, the outer wall of the shock absorber 1 is provided with a spring receiver 5a facing upward, and the outer wall of the main air splash chamber 3 is provided with a spring receiver 5b facing downward.
A coil spring 6 is loaded into these spring receivers 5a and 5bln.

Thus, 11 is a compressor. The compressor 11 compresses the atmospheric air sent from the air cleaner 12 and supplies it to the dryer 13. The compressed air dried by silica gel etc. It is stored in the side reserve tank 15a. This reserve tank 15 is provided with a low pressure side reserve tank 15b. A compressor 1 driven by a compressor relay 17 is installed between the reserve tanks 15a and 15b.
B is provided.

Further, a pressure switch 18 is provided which is turned on when the pressure in the low-pressure side reserve tank 15b becomes equal to or higher than atmospheric pressure. When the pressure switch 18 is turned on, the compressor relay 17 is driven.

As a result, the reserve tank 15b is always kept below atmospheric pressure. And the high pressure side reserve tank 15
The route through which compressed air is supplied from a to the suspension unit S is indicated by a solid arrow.

That is, the compressed air from the reserve tank 15a is supplied to the air supply flow rate control valves (C, V) 19. Front air supply valve (F, 5up) 20, check bar 71/721° Front 6 solenoid valve (F R) 22. It is sent to the suspension unit FS2 for the front 6 through the solenoid valve (FL) 23 on the front left circle and to the suspension unit FSI on the front left circle. Similarly, the compressed air from the reserve tank 15a is supplied to the air supply flow rate control valve 19. Rear air supply valve (R, 5ul))
24. Check valve 25° Rear Ishikawa solenoid valve (RR) 26. Rear left circle solenoid valve (RL)
Rear Ishikawa suspension unit R32 via 27
, is sent to the rear left circular suspension unit R81. On the other hand, the exhaust route from the suspension unit S is indicated by a broken line arrow. In other words, the front suspension unit FS1. Exhaust from FS2 is solenoid valve 22.23, front exhaust valve (F, EX)
28 to the low pressure side reserve tank 15b, and the check valve 29 to the dryer 13.
is sent to the discharge side. In addition, the exhaust from Suya's suspension units R81 and R82 is controlled by the solenoid valve 26.
．． 27, the air is sent to the low pressure side reserve tank 15b via the rear exhaust valve (R, EX) 30, and is also sent to the discharge side of the dryer 13 via the check valve 31. Incidentally, an exhaust passage consisting of an exhaust solenoid valve 32 and a check valve 33 is provided between the air cleaner 12 and the dryer 13 in parallel with the compressor 11, and the compressed air is discharged in the direction of the dashed arrow through the dryer 13. Air is supplied through this exhaust solenoid valve (A
, EX) 32, check valve 33, air cleaner 12
released to the atmosphere via.

Further, 34 is a vehicle height sensor, and this vehicle height sensor 34 includes a front vehicle height sensor 34F that is attached to the lower arm 35 of the front right suspension of the vehicle and detects the front vehicle height of the vehicle, and a front vehicle height sensor 34F that is attached to the lower arm 35 of the front right suspension of the vehicle, and a front vehicle height sensor 34F that is attached to the lower arm 35 of the front right suspension of the vehicle. The rear vehicle height sensor 34R is attached to the lateral rod 36 and detects the rear vehicle height of the vehicle, and detection signals are supplied from these vehicle height sensors 34F134R to the control unit 31 as a vehicle height adjustment control section. be done.

Each sensor 34F, 34R in the vehicle height sensor 34 is
The distance from the normal vehicle height level and the low vehicle height level or high vehicle height level is detected respectively.

Further, the speedometer has a built-in vehicle speed sensor 38, which detects the vehicle speed and supplies its detection signal to the control unit 37.

Further, an acceleration sensor 39 is provided as a vehicle body posture sensor that detects changes in the posture of the vehicle body. This acceleration sensor 39 measures the pitch on the car's springs.

It is designed to detect changes in vehicle body posture such as roll and yaw. For example, when there is no acceleration, the weight is in a hanging state, and the light from the light emitting diode is blocked by the shielding plate and does not reach the photodiode. , the absence of acceleration is detected. When acceleration acts in the front and back, left and right, or up and down directions, the weight tilts or moves, and the acceleration state of the vehicle body is detected.

Further, 40 is an indicator for displaying oil pressure, and the display of this indicator 40 is controlled by the control unit 37. Further, 41 is a steering sensor that detects the rotational speed of the steering wheel 42, that is, the steering speed, and its detection signal is sent to the control unit 31. In general, numeral 43 is an accelerator opening sensor (not shown) that detects the depression angle of an accelerator pedal of the engine, and its detection signal is sent to the control unit 37. Further, 44 is a compressor relay for driving the compressor 11, and this compressor relay 44 is controlled by a control signal from the control unit 37. Furthermore, 45 is a pressure switch that is turned on when the pressure in the reserve tank 15a falls below a predetermined value, and its output signal is output to the control unit 31. In other words, when the pressure in the reserve tank 15a falls below a predetermined value, the pressure switch 45 is turned on, and the control unit 3
The compressor relay 45 is operated under the control of 7.

As a result, the compressor 11 is driven and compressed air is sent to the reserve tank 15a.
The pressure inside 5a is made equal to or higher than a predetermined value. A pressure sensor 46 detects the pressure in the main air spring chambers 3 of the rear suspension units R81 and R82, which is provided in a communication path that communicates the main air spring chambers 3 of the rear suspension units R3I and R32. A pressure signal detected by this pressure sensor 46 is output to the control unit 31.

Further, 47 is a parking brake switch (PSW), and its operation signal is output to the control unit 37. Also, 48 is the brake switch (BSW),
The operation signal is output to the control unit 37. In general, 49 is an A/T switch that outputs a signal according to the position of the selector lever of an automatic vehicle, and the signal is output to the control unit 37.

The opening and closing of the solenoid valves 22, 23, 26, 27, 32 and valves 19, 20, 24, 28, 30 are controlled by control signals from the control unit 37. In addition, the above solenoid valve 22.23.2
6°21 consists of a three-way valve, and its two states are shown in FIG. FIG. 2(A) shows a state in which the three-way valve is driven, and in this state compressed air moves along the path indicated by arrow A. On the other hand, FIG. 2(B) shows a state in which the three-way valve is not driven, and in this state compressed air moves along the path indicated by arrow B. Also, valve 19
．． 20, 24, 28, 30 and the solenoid valve 32 are two-way valves whose two states are shown in FIG. Figure 3 (A>) shows the state in which the solenoid valve is driven, and in this state compressed air moves in the direction of arrow C. On the other hand, when the solenoid valve is not driven, the state shown in Figure 3 (B) In this case, there is no flow of compressed air.

Furthermore, regarding the configuration of the air supply flow rate control valve 19, the fourth
It is shown in the figure. FIG. 4 (A> shows a state in which the solenoid valve is driven, and in this state compressed air moves in the direction of arrow C through the small diameter orifice 50. Therefore, the amount of compressed air that moves is small. On the other hand , when the solenoid valve is not driven, the state becomes as shown in FIG. 4 (8), and in this case, the compressed air moves through the large diameter path E and the small diameter orifice 60, so the supply of compressed air will be explained below. The processing shown in the flowchart shown in Fig. 5 is performed by the control unit 37, and the contents of the processing will be explained below.

First, it is detected based on the state of the brake switch 48 whether the main brake, that is, the foot brake is off (not depressed) (step 81). Here, if it is determined that the foot brake is not depressed, the vehicle speed sensor 38
Based on the vehicle speed signal output from the control unit 37, it is determined whether the vehicle speed is "0", that is, whether the vehicle is stopped (step 82).

Here, if it is determined that it is stopped, step S
Proceed to step 3. In this step S3, when it is determined that the handbrake, that is, the PSW 47 is on (that is, the handbrake is pulled), the A/T determines from which position the selector lever has been moved to which position according to the determinations in steps 84 to S7. The determination is made based on the switch 49. At this point, the selector lever is in neutral (N
) to the drive (D), “1” is sent to 7lag N in the control unit 37.
is set (step S8). Roughly speaking, if it is detected that the selector lever has been moved from reverse (R) to neutral (N>), the control unit 3
7 is set to "2" (step 89).
). If it is detected that the selector lever has been moved from neutral (N) to reverse (R), a flag N in the control unit 37 is set to "3" (step S10). Furthermore, if it is detected that the selector lever has been moved from drive (D) to neutral (N), "4" is set to 7 lug N in the control unit 37 (step $11).
. Next, the delay time T(
N) is read (step 512). In other words, attitude control starts after the selector lever is shifted (see Fig. 7).
This is performed after a delay of the delay time T(N) shown in B). This is because there is a delay between when the selector lever is shifted and when the attitude changes, so the time to start attitude control must also be delayed. Then, a control time Tc (
N) is determined (step $14). Next, flag N
The value of is determined (step 515). Here, if flag N is "1" or "2", that is, if the selector lever is shifted from neutral (N) to drive (D), or if the selector lever is shifted from reverse (R) to neutral (N) Since the rear wheels are about to go down, control proceeds to step 316 to raise the rear wheels. In other words, in the "Rear Up" mode that raises the rear wheel in the vehicle height adjustment mode of the valve opening/closing garment shown in Figure 6,
The valve marked “O” is Tc (N
) The rear suspension unit 1R is turned on for only a certain amount of time.
Reserve tank 15a in main air spring chamber 3 of 81, R82
Compressed air is sent from For this reason, Fig. 7(C)
The vehicle height of the rear wheels increases as shown in . Then, a vehicle height averaging unit time DT (for example, 0.05 seconds) is set to t (step 511). On the other hand, when flag N is "3" or "4", that is, when the selector lever is shifted from neutral (N> to reverse (R), or when the selector lever is shifted from drive (D) to neutral (
N) When the shift is made, the rear wheels tend to rise, so control proceeds to step 818 to lower the rear wheels.

In other words, rRear DownJ mode (7) rO which lowers the rear wheel in the vehicle height adjustment mode of the valve opening/closing garment shown in Figure 6.
The valve marked J is Tc (N) as shown in Figure 7 (B).
The rear suspension unit R8 was turned on for a limited time.
1, R82 main air spring to 3 compressed air is released to the atmosphere. Therefore, the vehicle height of the rear wheels decreases. Then, 10T is set to t (step 519). by the way,
When the process of step 317 or step S19 is completed, the above T(N) is set to Tb (step 520), and after the end of the control time Tc(N),
The output of the vehicle height sensor 34 is read into the control unit 31 for 0.45 seconds (step 521). Then, the average vehicle height for 0.45 seconds is calculated (step 52
2). It is determined whether the vehicle height average value calculated in this way is a standard vehicle height (normal vehicle height) (step 523).
. Here, if the vehicle height average value is the standard vehicle height, the process returns to step S1. On the other hand, if the average vehicle height is not the standard vehicle height, it is determined whether the average vehicle height is lower than the standard vehicle height (step 524). Here, if it is determined that the average vehicle height value is lower than the standard vehicle height, r
Tb-tJ is set.

In other words, the above delay time T(N) is t time (0.05 seconds)
only shortened. By shortening the delay time T(N) in this way, the time from when the selector lever is shifted to starting attitude control is brought forward, so that the vehicle height quickly approaches the standard vehicle height due to attitude control. And T(N)
Tb is set to (step 826), and the process returns to step s1. On the other hand, if it is determined that the average vehicle height is higher than the standard vehicle height, rTb+tJ is set to Tb (
step 527). In other words, the above delay time T(N) is 1
Time m (0,05 seconds) is lengthened. By increasing the delay time 111T(N) in this way, the time from when the selector lever is shifted to when attitude control starts is delayed, and the vehicle height rapidly approaches the standard vehicle height due to sudden attitude control. On the contrary, it prevents the ride from becoming uncomfortable.

By the way, when the handbrake is released and the car is started, rNOJ is determined in step S3, and the processes from step 828 onwards are performed.

In other words, control (return control) that is the opposite of the posture control in step 816 or 818 is performed. Here, if the flag N is set to "1", step 8
The control performed in step 16 is reversed (step 5).
29). In other words, rRear lowers the rear wheel in the vehicle height adjustment mode of the valve opening/closing garment shown in Figure 6, rRear lowers the rear wheel in QOWnJ mode,
The valve marked OJ is opened for TC (1) time and the car on the rear wheel side is lowered. On the other hand, if the flag N is set to "3" (step 530), the steps described above,
A control opposite to that performed in step 91B is performed (step 529). In other words, in the vehicle height adjustment mode of the valve opening/closing garment shown in Figure 6, the rear wheel is raised rRear UpJ mode rO
The valve marked J is opened for Tc (3) hours to raise the vehicle height on the rear wheel side (step 531). In this manner, when the handbrake is released and the vehicle starts moving, control is performed to restore the attitude control performed in step 316 or 818 above. Then, the flag N is returned to "0" and the process returns to step S1.

Thereafter, when the car stops and the direction in which the selector lever is shifted changes, a corresponding value is set in the flag N, and the above-described processing is performed.

By the way, by performing the process of correcting the delay time as in step S25.826 above, there is a learning function in which the optimal delay time is set to T(N>) while this process is performed several times. It has the following.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide an electronically controlled suspension device that can reduce the longitudinal shaking of the vehicle body that occurs when the selector lever is changed in an automatic vehicle. .

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an electronically controlled suspension device according to an embodiment of the present invention, FIGS. 2(A) and (B) are diagrams showing opening and closing of a three-way valve, and FIGS. 3(A) and (B) ) is a diagram showing the opening and closing of the solenoid valve, FIGS. 4A and 4B are diagrams showing the opening and closing of the air supply flow rate control valve, FIG. The figure shows opening and closing of valves during posture control and vehicle height adjustment, and FIG. 7 is a timing chart for explaining the operation of one embodiment. 15a, 15b... Reserve tank, 19...
Air supply flow rate control valve, 20...Front air supply valve, 24...Rear air supply valve, 28...Front exhaust valve, 30...Rear exhaust valve, 37...
・Control unit, 46... Parking brake switch, 47... Brake switch, 48...
A/T switch. Applicant's agent Patent attorney Takehiko Suzue Figure 2 Figure 3B Figure 41! ! ! ! l N 50hi 6th a! ! 1 Figure 7

Claims (1)

[Claims] A suspension unit provided for each wheel and having a fluid spring chamber, a vehicle height adjustment means that controls the supply and discharge of fluid to and from the fluid spring chamber to adjust the vehicle height of each wheel, and a selector lever position adjustment means. a first storage means for storing a delay time for starting posture control corresponding to the change state; a second storage means for storing a posture time corresponding to the change state; and a second storage means for storing the delay time for starting posture control when the position of the selector lever is changed. An electronically controlled suspension device comprising: means for later performing attitude control for the above-mentioned attitude control time using the vehicle height adjusting means.