JPS61222810A - Suspension device for vehicles - Google Patents

Abstract

PURPOSE:To improve an engine starting characteristic ever so better, by constituting an engine state detecting device so as to forbid the drive of a compressor till it detects a state of engine's stable running after engine starting, in case of a device, bearing the above caption, capable of performing attitude control or level control. CONSTITUTION:An on-signal of an engine switch 51 is inputted into a controller 36. Likewise, hydraulic pressure of engine lubricating oil is inputted into the controller 36 by means of a hydraulic pressure sensor 47. This hydraulic pressure 47 is compared with the setting value. This setting should be set in a manner conformable to hydraulic pressure to be obtained when idle running stabilizes after engine starting. Therefore, while the detected hydraulic pressure 47 is below the setting value, an engine is nonoperational or it is not yet reached to its stable revolution so that a compressor 19 is kept in nonoperational. However, when the hydraulic pressure exceeds the setting value, it takes in pressure 35 in a reserve tank 21 and controls the drive of the compressor 19 by comparison with the setting pressure. With this constitution, an engine starting characteristic is improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suspension system for a vehicle, which has an attitude control function that suppresses roll displacement of a vehicle body during cornering, or a vehicle height adjustment function that adjusts the vehicle height to a desired height.

In recent years, suspension units have been developed that each wheel has its own air spring chamber for the purpose of the above-mentioned attitude control function or vehicle height adjustment function!・A reserve tank that stores compressed air that is supplied to each air spring chamber of each suspension unit via a supply control valve, and a reserve tank that stores compressed air that is supplied to each air spring chamber of each suspension unit through a discharge control valve. A discharge means for discharging compressed air, a compressor for sending compressed air into the reserve tank, a reserve tank pressure detection means for detecting the pressure in the reserve tank, and a set value of the pressure in the reserve tank by the reserve tank pressure detection means. A suspension is known which includes a compressor control means for driving the compressor when detecting that C is less than C. However, in such a suspension device, even immediately after the engine starts, if the pressure in the reserve tank is less than the set value, the compressor, which has a relatively large load, is driven, so the compressor cannot be driven. It takes a long time for the pressure of the engine oil in the engine to reach a predetermined value or higher, which is unfavorable in terms of engine lubrication, and also has drawbacks such as the inability to stabilize the idle rotation of the engine. In addition, especially when the starter motor is driven to start the engine, if the compressor, which consumes relatively large amount of power, is driven at the same time, the rotation speed of the starter motor will not increase sufficiently and the engine will not start. I was used to having problems that didn't go well.

SUMMARY OF THE INVENTION The object of the present invention is to provide a suspension device that can overcome the above-mentioned drawbacks.

The present invention was devised in view of the above, and includes a suspension engine unit provided for each wheel, each having an air spring and a spring chamber, and a suspension unit that supplies air to each air spring chamber of each suspension unit through a supply control valve. a reserve tank for storing compressed air, a discharge means for discharging the compressed air from each air spring chamber of each suspension unit via a discharge control valve, a compressor for sending compressed air to the reserve tank, and the reserve tank. and a compressor control means for driving the compressor when the reserve tank pressure detecting means detects that the pressure within the reserve tank is less than a set value. The apparatus includes an engine state detection means for detecting the state of the engine after the engine has been started, and a drive of the compressor until the engine state detection means detects that the engine is being operated stably after the engine has been started. The gist of the present invention is a suspension system for a vehicle, which is characterized by being equipped with a control means for prohibiting.

According to the present invention, after the engine is started, the compressor is prohibited from driving until it is detected that the engine is running stably, so there is no need to worry about engine lubrication problems or problems with idling speed. This has the effect of eliminating the problem and the problem with the startability of the engine.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the entire suspension system according to an embodiment of the present invention, where SFR is a suspension unit for the right front wheel of an automobile, SFL is a left 6F suspension unit, and SRR is a suspension unit for the right rear wheel of an automobile. Unit SRL indicates a suspension unit for the right rear wheel. Each of these subenzidine units SFR,S
Since FL, SRR, and SRL each have the same structure, suspension units 1. The structure of only sRL will be shown. The suspension unit SRL includes a main chamber jKtftth chamber 11, a sub air spring chamber 12, a shock absorber 13, and a coil spring (not shown) used as an auxiliary spring. 14 is a pneumatic switching device for switching the damping force of the shock absorber 13 between hard and soft. 15 is a bellows defining the main air spring chamber. Note that the switching device 14 simultaneously controls communication and non-communication between the main air spring chamber 11 and the sub air spring chamber 12, and switches between hard and soft air springs. Note that the switching device 14
This control is performed by a controller 36, which will be described later.

Reference numeral 16 indicates an air cleaner, and reference numeral 17 indicates that the air sent from the air cleaner 16 is sent to the dryer 18 via a solenoid valve 17 for shutting off outside air. The air dried by the dryer 18 is compressed by a compressor 19 and stored in a reserve tank 21 via a check valve 20. This compressor 19 uses electric power generated by a generator driven by an engine (not shown) as a driving source. In addition, 191 is a relay for the compressor,
This relay 191 is controlled by a controller 36 equipped with a microcontroller.

The reserve tank 21 is connected to the main air spring chambers 11.12 of each of the suspension units SRL to FL through air supply piping 23 in which air supply solenoid valves 221 to 224 are respectively installed. Suspension unit S
The main and auxiliary air spring chambers 11.12 of the RL and SRH are interconnected by a communication pipe 25 in which a communication solenoid valve 241 is interposed, and the suspension unit S FI
The main and auxiliary air spring chambers 11 and 12 of J and SFH are connected to each other by a communication pipe 25 in which a communication solenoid valve 241 is interposed. The compressed air in the main air spring chambers 11.12 of each suspension unit 1-3RL to SFL is supplied to exhaust piping 28, which is equipped with exhaust solenoid valves 271 to 274, check valves 29, dryer 18, and solenoids. It is discharged via the valve 17 and the air cleaner 16.

A piping 31 in which a solenoid valve 30 for selecting an air supply side flow path is interposed is arranged in parallel with the above-mentioned air supply piping 23 . Also,
A pipe 33 in which an exhaust side flow path selection solenoid valve 32 is interposed is arranged in parallel with the exhaust pipe 28 . A solenoid valve 34 for hard/soft switching is interposed between the air supply pipe 23 and the switching device 14, and the solenoid valve 34 for hard/soft switching receives a signal from the controller 36. Opening/closing is controlled by

In addition, solenoid valves 17.221 to 224.271
~274.30.34 are normally closed valves, and solenoid valves 241 and 242 are normally open valves.

Further, the pressure inside the reserve tank 21 is detected by a pressure sensor 35. A detection signal from this pressure sensor 35 is supplied to a controller 36. 37 is rear wheel suspension 3
Main and auxiliary air spring chambers of unit 5RLSSRH 11.1
This is a pressure sensor that detects the internal pressure of 2. The detection signal of this pressure sensor 37 is supplied to the controller 36.

38F is a front vehicle height sensor that is installed between the lower arm 39 on the front right side of the automobile suspension and the vehicle body to detect the vehicle height of the front portion of the automobile, and 38R is a lateral rod 40 on the rear left side of the automobile suspension. This is a rear vehicle height sensor that is installed between the vehicle body and detects the vehicle height at the rear of the vehicle. These vehicle height sensors 38F, 3
The vehicle height detection signal output from 8R is supplied to the controller 36. Both vehicle height sensors 38F and 38R are Hall ICs
One side of the element and the magnet are attached to the wheel side, and the other side is attached to the vehicle body side, and the distance from the normal vehicle height level, high vehicle height level, or low vehicle height level is detected respectively. 41 is a vehicle speed sensor that detects the vehicle speed; 42 is a steering sensor that detects the steering angle of the steering wheel 43; detection signals detected from these sensors 41 and 42 are supplied to the controller 36. 44 is an acceleration sensor that detects acceleration in the longitudinal, lateral, and vertical directions acting on the vehicle body.For example, when there is no acceleration, a weight is suspended, and a shielding plate linked to the weight causes light to be emitted. It is detected that there is no acceleration because the light from the diode does not reach the photodiode, and it is detected that acceleration is acting on the car body due to the weight being tilted or moved. A type of sensor is used.

45t1 vehicle height 1 is high vehicle height (HIGH), low vehicle height (LO
W), 46 is a vehicle height selection switch that sets the vehicle height adjustment (AUTO), and 46 is an attitude control selection switch that selects attitude control to reduce the roll of the vehicle.

be. Signals from these switches 45 and 46 are input to the controller 36. 47 is an oil pressure sensor that detects the oil pressure of lubricating oil for the engine, 48 is a brake sensor that detects the amount of depression of the brake, 49 is an accelerator opening sensor that detects the accelerator opening of the engine, and 50 is the engine rotation speed. An engine rotation speed detection sensor 51 is an engine switch such as an ignition switch for starting the engine, and 52 is a gear position detection sensor that detects the gear position of the transmission. The output signals of these switches 45, 46 and 51 and these sensors 4
The detection signals of 7, 48, 49, 50 and 52 are supplied to the controller 36.

Then, the controller 36 selects the target vehicle height set by the vehicle height selection switch 45 and the vehicle height sensors 38F, 38.
The vehicle height is adjusted by comparing the vehicle height detected by R and controlling each solenoid valve in a direction in which the vehicle height matches the target vehicle height.

Further, the attitude control function is performed by the controller 36 sensing the attitude change occurring in the vehicle body and its direction using each sensor, and controlling each solenoid valve to offset the attitude change.

In addition, when performing the above-mentioned vehicle height adjustment, the vehicle height is slowly changed by closing the intake side flow path selection solenoid valve 30 and the exhaust side flow path selection solenoid valve 32, thereby adjusting the vehicle height. This reduces the sense of discomfort experienced by the occupants. When performing the attitude control described above, by opening the solenoid valve 30 for selecting the air supply side flow path and the solenoid valve 32 for selecting the exhaust side flow path, it is possible to sufficiently cope with sudden changes in attitude.

Next, a first embodiment will be described with reference to FIG. 2 regarding control regarding the drive of the compressor 19 that supplies compressed air to the reserve tank 21.

The controller 36 is configured to perform processing according to the flowchart shown in FIG. First, in step S1, the state of the engine switch 51 is read into the controller 36, and then in step S2, it is determined whether the engine switch 51 is on. If it is determined in this step S2 that it is l”NOJ,
Since the engine has not been started yet, it is determined that starting the compressor 19 is inappropriate, and in step S3, it is confirmed that the compressor 19 has stopped, and the process returns to step S1 again to see the next change in the situation. In addition, in this step S3, if the compressor 19 is being driven, the compressor 19 is stopped. Also, in this step S2, rYEs
If it is determined that the oil pressure sensor 4 is
The value detected by the oil pressure sensor 47 is read into the controller 36, and the process proceeds to the next step S5, where it is determined whether the value detected by the oil pressure sensor 47 is equal to or greater than the set value.

Note that this set value is set in accordance with the oil pressure that can be obtained when the idle rotation of the engine is stabilized after starting. If the determination in step S5 is "NO", it is determined that the engine switch 51 has been turned on but has not started yet, or that the engine has started but has not yet achieved a stable rotational state, and the next situation change is determined. The process returns to step S1 via step S3 again in order to see the results. If rYESJ is determined in step S5, the process proceeds to step S6, where the detection signal of the pressure sensor 35 is read into the controller 36 in order to know the internal pressure of the reserve tank 21. Then, in step S7, it is determined whether the internal pressure of the reserve tank 21 is less than the first set value (for example, 7 kg/cd), and if it is determined as rYEsJ in step S7, it is necessary to replenish the reserve tank 21 with compressed air. After determining that there is a signal and sending a signal to the compressor relay 191 to drive the compressor 19 in step S8, the process returns to step S1 to check the next change in the situation. Incidentally, if the compressor 19 is already being driven in step S8, then the driving is confirmed. Further, if the determination in step S7 is "NO", the process proceeds to step S9, and the internal pressure of the reserve tank 21 is less than a second set value (for example, 9.skg/cd) which is larger than the first set value. It is determined whether If the determination in step S9 is "NO", it is determined that the internal pressure of the reserve tank 21 is sufficient, and the process proceeds to step S3, where a signal is sent to the compressor relay 191 to stop the compressor 19. Also, rY E S in step S9.

If so, it is determined that there is no need to replenish the reserve tank 21 with compressed air, and the process returns to step S1 to see the next change in the situation.

According to the first embodiment shown in FIG. 2, driving of the compressor 19 is reliably prohibited when the pressure of the engine lubricating oil is less than the set value. Compressor 1 is activated only when the pressure has risen sufficiently and the engine is operating in stable conditions.
9 can be driven. Therefore, compressor 19
It is possible to eliminate problems with lubrication, problems with idle rotation, and problems with startability caused by the load acting on the engine when the engine is driven.

Next, a second embodiment will be explained according to FIG.

In this second embodiment, a pressure switch is employed as the oil pressure sensor 47, which outputs a signal only when the oil pressure exceeds a set value. Note that, like the first embodiment, this set value is set to a level of oil pressure that can only be obtained when the idle rotation of the electric engine stabilizes after it has been started. In this second embodiment, step S10 is provided in place of step S5 between step S4 and step S6 in the first embodiment, and this step 31
0, it is determined whether the oil pressure sensor consisting of an oil pressure switch is outputting a signal, and if rYESJ, snap S6
If the answer is "NO", the process proceeds to step S3.

Therefore, according to this second embodiment, it is possible to obtain effects exactly similar to those of the first embodiment.

Next, a third embodiment will be explained according to FIG.

The controller 36 is configured to perform processing according to the flowchart shown in FIG. First, in step 311, the state of the engine switch 51 is read into the controller 36, and then in step 812, it is determined whether the engine switch 51 is on. If it is determined in this step S12 that it is rNOJ, the engine has not been started yet and the compressor 1
It is determined that the start of step 9 is inappropriate, and in step 313 it is confirmed that the compressor 19 has stopped, and the process returns to step Sll again to see the next change in the situation. Note that this step 31
In step 3, if the compressor 19 is running, the compressor 19 is stopped. Manako step 31
If rYEsJ is determined in step 2, the process proceeds to step 314, where it is determined whether the timer has already started. If rNOJ is determined in this step 314, the process proceeds to step 315 and a timer is set.
If rYEsJ is determined in step 4, then in step 316 it is determined whether or not the timer has elapsed for a set time of t0 seconds or more. The set time to seconds is set to a time sufficient for the engine to start after the engine switch 51 is turned on and for the idle rotation of the engine to stabilize. If “NO” is determined in this step 316,
It is determined that the engine switch 51 has been turned on but has not started yet, or that the engine has started but has not yet achieved a stable rotational state, and the process returns to step 811 via step S13 to see the next change in the situation. return. Also, if it is determined in step 814 that it is rYEsJ,
Proceeding to step 317, the detection signal of the pressure sensor 35 is read into the controller 36 in order to know the internal pressure of the reserve tank 21. Then, in step 318, the internal pressure of the reserve tank 21 is set to the first set value (for example, 7 kg/c
nr ), and if rYEsJ is determined in this step 318, it is determined that compressed air needs to be replenished into the reserve tank 21, and the compressor relay 191 is activated in order to drive the compressor 19 in step 319.
After sending the signal to , the process returns to step 311 to see the next change in status. Incidentally, if the compressor 19 is already being driven in this step 319, then the driving is confirmed. If rNOJ is determined in step 318, the process proceeds to step 320 where the internal pressure of the reserve tank 21 is set to a second set value (for example,
9.5 kg/cd). If rNOJ is determined in this step 320, it is determined that the pressure in the reserve tank 21 is already sufficient, and the process proceeds to step 313, where a signal is sent to the compressor relay 191 to stop the compressor 19. If the determination is YES in step 320, it is determined that there is no need to replenish the reserve tank 21 with compressed air, and the process returns to step 311 to see the next change in the situation.

According to the third embodiment shown in FIG. 4, driving of the compressor 19 is reliably prohibited when the set time has not elapsed since the engine switch 51 was turned on. The compressor 19 can only be driven when the pressure of the lubricating oil increases sufficiently and the engine is operated in a stable state. Therefore, it is possible to eliminate problems with lubrication, problems with idle rotation, and problems with startability caused by the load acting on the engine when the compressor 19 is driven.

Next, a fourth embodiment will be explained according to FIG.

The controller 36 is configured to perform processing according to the flowchart shown in FIG. First, the state of the engine switch 51 is read into the controller 36 in step 321, and then in step S22 it is determined whether the engine switch 51 is on. If it is determined in this step S22 that it is rNOJ, the engine has not been started yet and the compressor 1
It is determined that the start of the compressor 19 is inappropriate, the stoppage of the compressor 19 is confirmed in step 823, and the process returns to step 321 again to see the next change in the situation. Note that this step 32
In step 3, if the compressor 19 is running, the compressor 19 is stopped. Also, this step S2
If rYEsJ is determined in step 2, the process proceeds to step 824, where the value detected by the rotation speed detection sensor 50 is read into the controller 36, and the process proceeds to the next step S25, where the value detected by the rotation speed detection sensor 50 is set as the set value. It is determined whether or not the value is greater than or equal to the value. Note that this set value is set in accordance with the rotation speed (for example, 7 oOrpm) that can be obtained when the idle rotation of the engine becomes stable after starting. If rNOJ is determined in this step 325, it is determined that the engine switch 51 has been turned on but has not started yet, or that the engine has started but has not yet achieved a stable rotational state, and the next change in status is determined. If possible, the process returns to step 321 via step 323 again. If rYEsJ is determined in step 825, the process proceeds to step S26, and the detection signal of the pressure sensor 35 is sent to the controller 36 in order to know the internal pressure of the reserve tank 21.
is loaded into. Then, in step S27, it is determined whether the internal pressure of the reserve tank 21 is less than the first set value (for example, 7ki10h), and in this step S27, rYEsJ
If it is determined that it is necessary to replenish compressed air in the reserve tank 21ζ, a signal is sent to the compressor relay 191 to drive the compressor 19 in step 32B, and then in step S21 to check the next change in the situation.
Return to Incidentally, if the compressor 19 is already being driven in this step 328, then the driving is confirmed.

Further, if the determination in step 327 is "NO", the process advances to step 329 and the internal pressure of the reserve tank 21 is determined to be the first level.
(e.g., 9, 5
kg/e+/). If the determination in step 329 is "NO", it is determined that the pressure inside the reserve tank 21 is sufficient, and step S2
3, a signal is sent to the compressor relay 191 to stop the compressor 19. Also, step S29
If it is determined that the result is rYEsJ, it is determined that there is no need to replenish the reserve tank 21 with compressed air, and the process returns to step 321 to see the next change in the situation.

According to the fourth embodiment shown in FIG. 5, when the engine speed is less than the set value, the compressor 19
Since the drive of the compressor 19 is reliably prohibited, the compressor 19 can be driven only when the pressure of the oil for lubricating the engine is sufficiently increased and the engine is operated in a stable state. Therefore, it is possible to eliminate problems with lubrication, problems with idle rotation, and problems with startability caused by the load acting on the engine when the compressor 19 is driven.

In addition, in the flowcharts of each of the above-described embodiments, the step of turning off the compressor as an initial setting immediately after the first "start", or confirming that it has already been turned off, can be changed as necessary. It is possible to provide

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a suspension device according to the present invention, FIG. 2 is a flowchart showing a first embodiment of its control, FIG. 3 is a flowchart 1 showing a second embodiment, and FIG. Flowchart 1 showing the embodiment. FIG. 5 is a flowchart showing the fourth embodiment. S FR, S RR, S RR, S RL... Suspension unit. 191. Compressor, 21... Reserve tank, 3
6...Controller, 47 Oil pressure sensor, 50...Engine speed detection sensor, 51...Engine switch Fig. 2 Fig. 3 Fig. 4 Fig. 5熾-3df ?2 ri

Claims (1)

[Claims] A suspension unit provided for each wheel and each having an air spring chamber, a reserve tank that stores compressed air to be supplied to each air spring chamber of each suspension unit via a supply control valve, and each air spring chamber of each suspension unit. a discharge means for discharging compressed air from the spring chamber via a discharge control valve; a compressor for feeding the compressed air into the reserve tank; a reserve tank pressure detection means for detecting the pressure in the reserve tank; and a compressor control means for driving the compressor when the detection means detects that the pressure in the reserve tank is less than a set value, the engine state detection detecting the state of the engine after the engine is started. and a control means for prohibiting driving of the compressor until the engine state detection means detects that the engine is being operated stably after starting the engine.