JP2521843Y2 - Suspension device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention relates to a vehicle equipped with an automatic transmission having a fluid transmission device. The present invention relates to a vehicle suspension device capable of preventing a vehicle.

(Prior Art) In a vehicle equipped with an automatic transmission having a fluid transmission, when the transmission is held in a traveling position (for example, a drive position) and the brake pedal is released from a depressed state, the foot is released. A so-called squat occurs when the vehicle starts suddenly and the rear part of the vehicle body descends.

(Problems to be solved by the invention) This squat is not so large when the accelerator pedal is not depressed before releasing the brake pedal, so the occupant does not feel too uncomfortable, When the accelerator pedal is depressed before releasing the vehicle, there is a problem that the passenger feels uncomfortable. Furthermore, when the suspension arm supporting the wheels extends in the front-rear direction of the vehicle body, when the brake device is actuated, a suspension lock phenomenon occurs, in which displacement of the suspension is substantially inhibited. When the shift position of the transmission is changed from neutral to the drive position, and the accelerator pedal is depressed and the foot is released from the brake pedal, the squat appears more remarkably.

The purpose of the present invention is to provide a vehicle equipped with an automatic transmission having a fluid transmission device, even if a start operation such as releasing the foot from the brake pedal while holding the transmission in the traveling position and depressing the accelerator pedal is performed. Another object of the present invention is to provide a vehicle suspension device that can reduce sinking of a rear portion of a vehicle body.

[Constitution of the Invention] (Means for Solving the Problems) In a vehicle for transmitting the power of an engine to the vehicle via an automatic transmission having a fluid transmission, a fluid interposed between a rear wheel and the vehicle body A spring chamber, a shock absorber interposed between the rear wheel and the vehicle body and capable of adjusting a damping force, a fluid supply means for supplying a fluid to the fluid spring chamber via a supply control valve, and the fluid spring Fluid discharge means for discharging a fluid from a chamber via a discharge control valve, brake detection means for detecting an operation state of a brake, vehicle speed detection means for detecting a vehicle speed, and an accelerator for detecting an opening degree of an accelerator pedal of an engine The brake device is in an operating state by the opening degree detecting means, the brake detecting means, the vehicle speed detecting means, and the accelerator opening degree detecting means, and the vehicle speed is equal to or lower than the set vehicle speed and the accelerator opening degree is set to the opening degree. When the above condition satisfies a first condition that has continued for a set time or more, a first control signal for increasing the damping force of the shock absorber is output. A second control signal for opening the supply control valve is output when the operation state is detected, and a third control signal for reducing the damping force of the shock absorber when a set time has elapsed thereafter is output. And a control means for outputting the output.

(Operation) When the foot brake is depressed while the vehicle is stopped and the accelerator pedal is depressed for a set time or more, the damping force of the shock absorber is increased by the first control signal, and the foot brake is depressed. Is supplied in accordance with the control target to the fluid spring chamber interposed between the rear wheel and the vehicle body by the second control signal when is released, and when the set time elapses thereafter, the third control signal This reduces the damping force of the shock absorber.

(Embodiment) Hereinafter, a vehicle suspension device according to an embodiment of the present invention will be described with reference to a screen. In FIG. 1, since the air suspension units FS1, FS2, RS1, and RS2 have substantially the same structure, the air suspension units will be hereinafter described except for the case where the front and rear units are separately distinguished. Will be described using the symbol S.

That is, the air suspension unit S incorporates a strut-type shock absorber 1. The shock absorber 1 is slidably fitted in a cylinder 2 mounted on a front wheel or a rear wheel side. With the piston 3 provided, the cylinder 2 moves up and down with respect to the piston rod 4 according to the up and down movement of the wheel, so that shock can be effectively absorbed. Incidentally, reference numeral 5 denotes a damping force switching valve, and the rotation of the damping force switching valve 5 is controlled by an actuator 5a.
Select whether the first damping chamber 6a and the second damping chamber 6b communicate with each other only through the orifice a1 (hard state) or with both the orifices a1 and a2 (soft state). Is done. The driving of the actuator 5a is controlled by a control unit 37 described later.

An air spring chamber 7 also serving as a vehicle height adjustment fluid chamber is disposed coaxially with the piston rod 2 above the shock absorber 1, and a bellows 8 is provided in a part of the air spring chamber 7. Since it is formed, the vertical movement of the piston rod 4 can be allowed by supplying and discharging air to and from the air spring chamber 7 through the passage 4a provided in the piston rod 4.

The outer wall of the shock absorber 1 is provided with a spring receiver 9a facing upward, and the outer wall of the air spring chamber 7 is formed with a spring receiver 9b facing downward. A coil spring 10 is loaded between 9b.

Thus, 11 is a compressor. The compressor 11 compresses the air sent from the air cleaner 12 and supplies the compressed air to the dryer 13 .The compressed air dried by the silica gel or the like of the dryer 13 is supplied to the high pressure in the reserve tank 15 through the check valve 14. It is stored in the side reserve tank 15a. The reserve tank 15 is provided with a low-pressure side reserve tank 15b. A compressor 16 driven by a compressor relay 17 is provided between the reserve tanks 15a and 15b. Further, a pressure switch 18 that is turned on when the pressure of the low-pressure side reserve tank 15b becomes higher than the atmospheric pressure is provided. And
When the pressure switch 18 is turned on, the compressor relay 17 is driven. As a result, the reserve tank 15
b is always kept below atmospheric pressure. The path through which compressed air is supplied from the high-pressure reserve tank 15a to the suspension unit S is indicated by solid arrows. That is, the compressed air from the reserve tank 15a is supplied with a supply air flow control valve 19, which is a three-way valve described later, a front supply air supply solenoid valve 20, a check valve 21, a front right solenoid valve 22, and a front left solenoid valve. twenty three
Via the front right suspension unit FS2 and the front left suspension unit FS1.
Similarly, compressed air from the reserve tank 15a is supplied with an air supply flow control valve 19, which is a three-way valve described later, an air supply solenoid valve 24 for a rear wheel, a check valve 25, a solenoid valve 26 for a rear right, and a rear left solenoid valve 26. Solenoid valve 27
Through the rear suspension unit RS2 for the rear right and the suspension unit RS1 for the rear left. The downstream of the check valve 21 and the downstream of the check valve 25 are connected via a check valve 211. On the other hand, the exhaust path from the suspension unit S is indicated by a dashed arrow. That is, the exhaust from the suspension units FS1 and FS2 is performed by the solenoid valves 22 and 23, the front exhaust valve 28, and the residual pressure valve 29 if the exhaust valve 28 is in the exhaust driving state.
Is sent to the low-pressure side reserve tank 15b via the Further, the exhaust from the suspension units FS1 and FS2 is performed by the solenoid valve 2 if the exhaust valve 28 is in a driving state.
2, 23, the front exhaust valve 28, the dryer 13, the exhaust solenoid valve 30, and the air cleaner 12 release the air. Exhaust from suspension units RS1 and RS2 is supplied to solenoid valves 26 and 27, rear exhaust valve 31, and residual pressure valve 3
It is sent to the low-pressure side reserve tank 15b via 2. When the pressure in the reserve tank 15b is smaller than the pressure in the main air spring chamber 3, the residual pressure valves 29 and 32 are opened. When the pressure in the reserve tank 15b is larger than the pressure in the main air spring chamber 3, the residual pressure valve 29 , 32 are closed. In addition, the exhaust from suspension units RS1 and RS2 is exhaust valve 31
Are in the driving state, the solenoid valves 26 and 27, the rear exhaust valve 31, the dryer 13, the exhaust solenoid valve 30,
It is released to the atmosphere through the air cleaner 12. Reference numeral 33 denotes a pressure switch provided in a communication passage communicating with the rear air spring chamber 3, and its operation signal is output to a control unit described later.

Reference numeral 34 denotes a vehicle height sensor. The vehicle height sensor 34 is attached to a lower arm 35 of a front right suspension of the vehicle and detects a front vehicle height of the vehicle.
And a lateral rod on the rear left suspension of the car
A rear vehicle height sensor 34R, which is attached to the vehicle 36 and detects the rear vehicle height of the vehicle, is provided. A detection signal is supplied from these vehicle height sensors 34F, 34R to the control unit 37.

Each of the sensors 34F and 34R in the vehicle height sensor 34 detects a distance from a normal vehicle high level, a low vehicle high level, or a high vehicle high level, respectively.

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

Further, an acceleration sensor for detecting lateral acceleration such as a differential transformer type G sensor 39 is provided as a vehicle body attitude sensor for detecting a change in the attitude of the vehicle body.
The output voltage V of the G sensor 39 increases as the acceleration G increases. An example of the output voltage is shown in FIG.

Reference numeral 40 denotes an indicator for displaying the operation of the control. The display of the indicator 40 is controlled by the control unit 37. Also, 41 is the rotation speed of the steering wheel 42,
That is, the steering sensor detects the steering speed, and the detection signal is sent to the control unit 37. Also, 43
Is a brake switch for detecting the operation of the foot brake, and the operation signal is output to the control unit 37. The operation signal is an ON signal when the foot brake is depressed.

A throttle sensor 44 outputs a throttle voltage proportional to the throttle opening of the engine (not shown). The throttle voltage output from the throttle sensor 44 is sent to the control unit 37. Reference numeral 45 denotes a compressor relay for driving the compressor 11, and the compressor relay 45 is controlled by a control signal from the control unit 37. Reference numeral 46 denotes a pressure switch that is turned on when the pressure of the reserve tank 15a becomes equal to or less than a predetermined value. In other words, when the pressure of the reserve tank 15a falls below a predetermined value, the pressure switch 4
6 is turned on, and the compressor relay 45 is operated under the control of the control unit 37. As a result, the compressor 11 is driven to send compressed air to the reserve tank 15a, and the pressure in the reserve tank 15a is increased to a predetermined value or more. The above solenoid valves 20, 22, 23, 24, 26, 27,
Opening and closing control of 30 and valves 19, 28, 31 is performed by control signals from the control unit 37. The solenoid valves 22, 23, 26 and 27 and the valves 19, 28 and 31 are three-way valves, and the two states are shown in FIG. FIG. 2A shows a state in which the three-way valve is driven. In this state, the compressed air moves along a path indicated by an arrow A. On the other hand, FIG. 2 (B) shows a state where the three-way valve is not driven. In this state, the compressed air moves along a path indicated by arrow B. The solenoid valves 20, 24, 30 are two-way valves, and the two states are shown in FIG. FIG. 3A shows a state in which the solenoid valve is driven. In this state, the compressed air moves in the direction of arrow C. On the other hand, when the solenoid valve is not driven, the state becomes as shown in FIG. 3B, and in this case, there is no flow of compressed air.

Next, the operation of the embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG. 5 and the timing chart of FIG. First, the vehicle speed is 3km / h or less,
That is, it is determined whether the vehicle is stopped (step
S1). Next, it is determined whether the throttle voltage output from the throttle sensor 44 is 1.7 V or more (step
S2). Here, the throttle voltage 1,7V is the throttle voltage (1.2V to 1.4V) when the engine overspeeds under no load condition.
It is set higher than V). Then, when the throttle voltage is 1.7 V or more and continues for 1.0 second in the vehicle equipped with the automatic transmission, it is determined that the brake is operated or the external force is applied. At the point a in FIG. 6, it is determined "YES" in step S2. That is, if the accelerator is depressed while the brake is being depressed, the process proceeds to step S3 to determine whether the throttle condition is set. It is determined whether or not. When the process proceeds to step S3 for the first time, "N
"O" is determined, and the throttle condition is set (step S4). Then, the throttle timer Th is reset to start the timing operation, and the time when the throttle voltage is equal to or higher than 1.7 V is measured (step S5). Thereafter, returning to the processing after step S1, if the procedure comes to step S3 in a state where the throttle voltage is 1.7 V or more, it is determined to be “YES” in step S3 and the timer Th is incremented (step S3). S6). Then, it is determined whether or not the timer Th has become longer than 1.0 second (step S7). Here, until the point b in FIG. 6 comes, the timer Th is incremented by the processing of step S6, and when it comes to the point b, processing for hardening the damping force of the suspension unit is performed. That is, the damping force timer Tc is reset, and the clocking operation is started (step S8). Then, the damping force of each wheel is hardened (step S9). Then, it is determined whether or not the foot brake has been released (step S10). If the foot brake is depressed, the process returns to step S1. When the point c in FIG. 6 comes, "YES" is determined in step S10, and the process proceeds to step S11 and subsequent steps. First, it is determined whether or not a control flag indicating that squat control by supplying air to the rear has been started is set (step S1).
1). When the process comes to step S11 for the first time, the control flag which is determined as “NO” is set (step S1
2). Then, the timer Ts for counting the air supply time to the rear is reset and its time counting operation is started (step S1).
3). Then, the rear air supply valve is opened to supply air to the rear suspension unit (step S1).
Four). That is, first, when the accelerator pedal is depressed while the brake pedal is depressed for a predetermined time in preparation for a sudden start, the damping force of the shock absorber is increased, whereby the sinking of the vehicle body due to torque is suppressed. Then, when the brake pedal is released from this state, the fluid is further supplied to the fluid spring chamber of the rear wheel, so that a larger sinking of the vehicle body due to the torque and the acceleration of the vehicle body is effectively reduced. Such a sudden start operation is detected from three parameters of the brake operating state (the state of the brake switch 43), the vehicle speed (the output of the vehicle speed sensor 38), and the opening degree of the accelerator pedal of the engine (the output of the throttle sensor 44). Since it is not used as a parameter whether or not the shift position of the transmission is at the traveling position, wiring for receiving signals from the transmission can be eliminated, and the control unit 37 can be used.
There is an advantage that the signal processing in can be simplified. Thereafter, the process returns to step S1, and when the process returns to step S11, the control flag has already been set, so that the determination is "YES", and the timer Ts is incremented (step S15). And the count value of the timer Ts is the control target.
At the point d in FIG. 6 which is longer than 0.15 seconds, step S1
If "YES" is determined in 6, the rear air supply valve is turned off, and the air supply to the rear suspension unit is stopped (step S17). Hereinafter, the process proceeds to step S18,
The timer Tc is incremented, and it is determined whether the timer Tc is longer than 2.0 seconds (step S19). Until the point e in FIG. 6 is reached, the determination is "NO" and the process returns to step S1. Since it is determined in step S10 that the foot brake has been released, "NO" is determined in step S1 or step S2. If "NO" is determined in step S2, the throttle condition is reset (steps S20 and S21). Then, it is determined whether the damping force is hard (step S22). Since the damping force is still hard, “YES” is determined and the process proceeds to step S15.
Then, the process proceeds to step S18 via steps S15 to S17, and the timer Tc is incremented. Then, when the point e in FIG. 6 is reached, "YES" is determined in the processing of step S19, the damping force of the suspension unit is softened (step S20), and the control flag is reset (step S21). In this way, a series of processing is completed. In other words, if the throttle voltage is 1.7V or more for more than 1.0 second, the damping force of the suspension unit will be hardened from point b, and from point b
1.0 seconds later, rear air supply is performed for 0.15 seconds. And
The damping force of the suspension is held hard from the point b, and the damping force is kept hard for 2 seconds after the rear air supply ends.

As is clear from the above description, according to the above configuration, in a vehicle including an automatic transmission having a fluid transmission, the brake pedal is released from the foot while holding the transmission in the traveling position and depressing the accelerator pedal. Even if the start operation is performed, the damping force of the suspension unit is increased at 1.0 seconds when the accelerator pedal is depressed first, and then when the foot is released from the brake pedal, that is, the vehicle body posture tries to start suddenly Compressed air is supplied to the air spring chamber of the rear wheel at the timing of sinking, so that sinking at the rear of the vehicle body can be effectively reduced. The damping force is switched to a higher value before the brake SW is turned from ON to OFF, that is, before the squat actually occurs.Therefore, sufficient amount of anti-squat control by supplying air to the air spring chamber of the rear wheels is sufficient. Can be supplemented. (Because there is a slight time delay in the air supply, the high damping force is maintained for a set time even after the air supply to the air spring chamber of the rear wheel is completed. The troubles felt by can be reduced.

[Effects of the Invention] As described in detail above, according to the present invention, in a vehicle equipped with an automatic transmission having a fluid transmission, the transmission is held in a traveling position and the accelerator pedal is depressed and the brake pedal is released. It is possible to provide a vehicle suspension device that can reduce the sinking of the rear part of the vehicle body even when the starting operation such as releasing the foot is performed.

[Brief description of the drawings]

FIG. 1 is a view showing an electronic control suspension apparatus according to an embodiment of the present invention, FIGS. 2 (A) and 2 (B) are views showing driving and non-driving states of a three-way valve, and FIG. 3 is a solenoid valve. FIG. 4 is a diagram showing an example of an output voltage of the G sensor, FIG. 5 is a flowchart showing an operation of an embodiment of the present invention, and FIG. FIG. 5a… Actuator, 11… Compressor, 15… Reserve tank, 19… Air supply flow control valve, 20… Front air supply solenoid valve, 24… Rear wheel air supply solenoid valve, 28…
Front exhaust valve, 31 ... Rear exhaust valve.

Continuing on the front page (72) Inventor Yasutaka Taniguchi 1 Nakashinkiri, Hashimecho, Okazaki City Inside the Mitsubishi Motors Corp. Passenger Car Technology Center (72) Inventor Shozo Takizawa 1 Nakashinagiri, Hashimecho, Okazaki City Mitsubishi In the Passenger Car Technology Center of the Automobile Industry Co., Ltd. (72) Minoru Tatemoto, 1 Nakashinkiri, Hashime-cho, Okazaki City, Mitsubishi Motors Co., Ltd. No. 1 Shinkiri Mitsubishi Motors Corporation Passenger Car Technology Center (56) References JP-A-58-78814 (JP, A) JP-A-59-186711 (JP, A) A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A vehicle for transmitting power of an engine to a vehicle via an automatic transmission having a fluid transmission, comprising: a fluid spring chamber interposed between a rear wheel and a vehicle body; A shock absorber interposed therebetween and capable of adjusting a damping force; a fluid supply means for supplying a fluid to the fluid spring chamber via a supply control valve; and a fluid from the fluid spring chamber via a discharge control valve. Means for discharging the fluid, brake detecting means for detecting the operation state of the brake, vehicle speed detecting means for detecting the vehicle speed, accelerator opening detecting means for detecting the opening of the accelerator pedal of the engine, and the brake detecting means The brake device is operated by the vehicle speed detecting means and the accelerator opening degree detecting means. When the first condition is satisfied, a first control signal for increasing the damping force of the shock absorber is output, and thereafter, the brake detecting means detects that the brake device has been changed from an operating state to a non-operating state. Control means for outputting a second control signal for opening the supply control valve when the control signal has been supplied, and for outputting a third control signal for reducing the damping force of the shock absorber when a set time has elapsed thereafter. A suspension device for a vehicle, comprising: