JP2012158313A - Control device for vehicle air suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle air suspension that can perform crouching control without fault even if the height of a road surface where the right and left wheels of a vehicle are grounded is different.SOLUTION: The control device for a vehicle air suspension is configured to detect in Step S1 whether a driver has turned on a crouching switch, and in Step 2, when detected that the driver has turned on the crouching switch, forcibly stop leveling control.

Description

  The present invention relates to a vehicle air suspension control device.

  In general, in the case of a vehicle such as a bus equipped with an air suspension control device and having an entrance at the front side, the wheel moves up and down due to unevenness or inclination of the road surface or the vehicle body tilts when stopping or running Even if it is going to do, leveling control to hold the car body parallel to the axle by holding the left and right vehicle heights independently at a constant height is performed, but when passengers get on and off, the entrance / exit is Crouching control is performed to lower the vehicle height at the front part of the vehicle so that passengers can easily get on and off.

  FIG. 3 is an overall schematic configuration diagram showing an example of a conventional vehicle air suspension control device, wherein 1 is a vehicle such as a bus, 2 is a front wheel of the vehicle 1, and 3 is a rear wheel of the vehicle 1. The air suspension control device is provided with a total of four front air springs 4 arranged one by one on the left and right so as to support the front wheel 2 and two pieces on the left and right two sides so as to support the rear wheel 3. A rear air spring 5, a front vehicle height adjustment valve 8 provided in an air pipe 7 connecting the front air spring 4 and the air tank 6, and supplying / discharging compressed air in the air tank 6 to / from the front air spring 4, respectively; Provided in an air line 9 that branches off from the air line 7 and connects the rear air spring 5 and the air tank 6 to the rear air spring 5. A rear vehicle height adjustment valve 10 for supplying and discharging the vehicle, a front vehicle height sensor 11 such as a potentiometer for electrically detecting left and right vehicle heights 11a at the front portion of the vehicle 1, and a left and right vehicle heights 12a at the rear portion of the vehicle 1 respectively. A rear vehicle height sensor 12 such as a potentiometer that is electrically detected, and a front vehicle height adjustment valve 8 and a rear vehicle height based on vehicle heights 11a and 12a detected by the front vehicle height sensor 11 and the rear vehicle height sensor 12. And a controller 13 that outputs control signals 8a and 10a to the regulating valve 10.

  In addition, the driver's seat of the vehicle 1 such as the bus is configured to perform crouching control so that the front portion of the vehicle 1 is lowered when the driver is turned ON / OFF and a predetermined condition is satisfied in the ON state. A crouching switch 14 is provided, and the crouching switch 14 is connected to the controller 13.

  In the vehicle air suspension control device, when the vehicle is stopped or running, the front vehicle height sensor 11 detects the left and right vehicle heights 11a at the front of the vehicle 1 and inputs them to the controller 13. In the controller 13, the vehicle 13 An average value of the left and right vehicle heights 11a in one front is calculated, and the average value is compared with a preset reference range, and the left and right vehicle heights 11a in the front of the vehicle 1 are compared with the reference range. When the average value is low, compressed air is simultaneously supplied to the left and right front air springs 4 by the control signal 8a to the front vehicle height adjusting valve 8, and the average value of the left and right vehicle heights 11a at the front portion of the vehicle 1 from the reference range is When it is high, compressed air is discharged simultaneously from the left and right front air springs 4 by a control signal 8a to the front vehicle height adjustment valve 8. It is. At the same time, the rear vehicle height sensor 12 detects the left and right vehicle heights 12a at the rear of the vehicle 1 and inputs them to the controller 13. In the controller 13, the left and right vehicle heights 12a at the rear of the vehicle 1 are set in advance as a reference. When the left and right vehicle heights 11a at the rear portion of the vehicle 1 are lower than the reference range, compressed air is supplied to the left and right rear air springs 5 by the control signal 10a to the rear vehicle height adjusting valve 10. On the contrary, when the left and right vehicle heights 11a at the rear portion of the vehicle 1 are higher than the reference range, the compressed air is discharged from the left and right rear air springs 5 by the control signal 10a to the rear vehicle height adjusting valve 10. In this way, leveling control is performed, and the left and right vehicle heights are independently maintained at a constant height even if the wheels move up and down due to the unevenness or inclination of the road surface or the vehicle body tilts. The vehicle body is held parallel to the axle. It is well known that the inclination correction of the vehicle 1 is more effective when it is performed on the rear axle side with a large axial load and a wide tread.

  On the other hand, when the driver runs the vehicle 1, arrives at a stop or the like, stops the vehicle 1, and operates the parking brake, when the crouching switch 14 is turned on by the driver, as described above, The front vehicle height sensor 11 detects the left and right vehicle heights 11a at the front portion of the vehicle 1 and inputs them to the controller 13. The controller 13 calculates the average value of the left and right vehicle heights 11a at the front portion of the vehicle 1, The average value is compared with a reference range for crouching control set in advance lower than the reference range, and the average value of the left and right vehicle heights 11a at the front portion of the vehicle 1 is within the reference range for crouching control. Simultaneously from the left and right front air springs 4 by a control signal 8a output from the controller 13 to the front vehicle height adjustment valve 8. Condensed air is discharged. In this way, in the case of a vehicle 1 such as a bus provided with a boarding gate at the front side, crouching control is performed, and the vehicle height at the front of the vehicle 1 provided with the boarding gate is lowered when passengers get on and off. It becomes possible to easily get on and off passengers.

  FIG. 4 is an overall schematic configuration diagram showing another example of a conventional vehicle air suspension control device. In FIG. 4, the parts denoted by the same reference numerals as those in FIG. Is similar to the conventional one shown in FIG. 3, but instead of providing the rear vehicle height adjusting valve 10 and the rear vehicle height sensor 12, the change in the left and right vehicle heights at the rear of the vehicle 1 is stretched from the valve body 15B. This is a type in which a rear leveling valve 15 is provided that mechanically detects the tilt of the lever 15L to be released, and supplies and discharges the compressed air in the air tank 6 to the rear air spring 5 in conjunction with the tilt of the lever 15L. is there.

  In the case of the other example shown in FIG. 4, when the vehicle height is lowered, the lever 15L of the rear leveling valve 15 tilts relatively upward in FIG. 4, and the compressed air in the air tank 6 is supplied to the rear air spring 5. On the other hand, when the vehicle height increases, the lever 15L of the rear leveling valve 15 tilts relatively downward in FIG. 4 and the compressed air is discharged from the rear air spring 5.

  For example, Patent Document 1 shows a general technical level related to the vehicle air suspension control apparatus as described above.

Japanese Patent Laid-Open No. 7-205630

  However, in the vehicle air suspension control device shown in FIG. 3 or FIG. 4, for example, as shown in FIG. 5, the height of the road surface on which the front wheel 2 on the right side of the vehicle 1 contacts is significantly higher than that on the left side. In the situation where the height of the road surface to which the rear wheel 3 (not shown in FIG. 5) contacts the ground is equal to the height of the road surface to which the front wheel 2 on the left side of the vehicle 1 contacts, When the control is performed and the compressed air is simultaneously discharged from the left and right front air springs 4 at the front of the vehicle 1, the bump stopper built in the right front air spring 4 serves as an upper surface plate of the front air spring 4. In some cases, the rubber contact state may occur, so that it cannot contract any further in the height direction.

  If the right front air spring 4 is in a rubber contact state before the average value of the left and right vehicle heights 11a in the front portion of the vehicle 1 falls within the reference range for crouching control, the left front air spring 4 Further, since the compressed air is continuously discharged, not only the vehicle height on the left side in the front portion of the vehicle 1 but also the vehicle height on the left side in the rear portion of the vehicle 1 is slightly lowered along with this operation. Compressed air is supplied to the left rear air spring 5 at the rear part of the vehicle 1 so that the vehicle body approaches parallel to the axle, and the vehicle height on the left side at the front part of the vehicle 1 is the right front in the rubber contact state. The air spring 4 is lifted so as to be lifted with the fulcrum as a fulcrum, and the average value of the left and right vehicle heights 11a at the front portion of the vehicle 1 is high. Thus, compressed air is discharged again from the left front air spring 4 so that the average value of the left and right vehicle heights 11a falls within the reference range for crouching control. Thereafter, the same operation as described above is repeated, and crouching control and leveling control are performed. Are alternately performed so that the control does not converge, and the vertical movement of the vehicle body continues until all the compressed air in the air tank 6 is consumed. In addition, if the compressed air is continuously discharged from the left front air spring 4 by the crouching control when the right front air spring 4 is in the rubber contact state, the right front air spring in the rubber contact state is discharged. Since the vehicle height change due to the spring 4 and the vehicle height change on the left side at the rear of the vehicle 1 are small, only the vehicle height on the left side at the front of the vehicle 1 is lowered. The vehicle height on the right side at the rear of the vehicle 1 becomes higher than the reference range, and the compressed air is discharged from the rear air spring 5 on the right side at the rear of the vehicle 1. Such an operation also accelerates the consumption of the compressed air in the air tank 6. It was a factor to make.

  In view of such a situation, the present invention is intended to provide a vehicle air suspension control device capable of reliably performing crouching control even when the height of a road surface on which a front wheel of a vehicle contacts is different on the left and right.

The present invention includes a front air spring that is arranged to support a front wheel of a vehicle and is supplied and discharged with compressed air in an air tank, and a compressed air in an air tank that is arranged to support a rear wheel of the vehicle. And a rear air spring that controls the leveling of the vehicle body in parallel to the axle by independently maintaining the left and right vehicle heights at a constant height. In a vehicle air suspension control device that performs crouching control to lower the vehicle height at the front of the vehicle,
The present invention relates to a vehicle air suspension control device comprising leveling control suspension means for forcibly stopping leveling control during the crouching control.

  According to the above means, the following operation can be obtained.

  As described above, when the leveling control suspension means for forcibly stopping the leveling control during the crouching control is provided, for example, the height of the road surface on which the front wheels on one of the left and right sides of the vehicle are grounded is significantly higher than that on the other side In a situation where the height of the road surface on which the rear wheel of the vehicle touches is equal to the height of the road surface on which the front wheels on the left and right sides of the vehicle touch the ground, the crouching control is performed, When compressed air is discharged from the front air spring at the same time, the bump stopper built in the front air spring on one of the left and right sides can contact the top plate of the front air spring and shrink further in the height direction. The so-called rubber contact state disappears, and compressed air continues from the front air springs on the left and right sides. With this operation, even if it is determined that not only the vehicle height on the other side of the left and right sides in the front part of the vehicle but also the vehicle height on the other side of the rear side of the vehicle is slightly lower, Since the leveling control is forcibly stopped, compressed air is not supplied to the rear air springs on the left and right sides of the rear part of the vehicle, and the vehicle heights on the left and right sides of the front part of the vehicle 1 The front air springs on the left and right sides of the state are not lifted so that they can be lifted, and the average value of the left and right vehicle heights at the front of the vehicle is prevented from increasing, and only crouching control is performed alone. It will be done reliably.

  As a result, it is avoided that crouching control and leveling control are alternately performed so that control does not converge, and the vertical movement of the vehicle body continues until all the compressed air in the air tank is consumed. No longer occurs.

In the vehicle air suspension control device, a rear vehicle height sensor for detecting left and right vehicle heights at the rear of the vehicle,
A rear vehicle height adjustment valve for supplying and discharging compressed air in the air tank to and from the rear air spring by a control signal output from a vehicle height control controller based on the vehicle height detected by the rear vehicle height sensor;
The leveling control pause means may be constituted by the rear vehicle height adjustment valve that shuts off supply and discharge of compressed air in the air tank with respect to the rear air spring during the crouching control.

In the vehicle air suspension control device, a change in the left and right vehicle heights at the rear portion of the vehicle is detected by tilting a lever protruding from the valve body, and an air tank is connected to the rear air spring in conjunction with the tilting of the lever. A rear leveling valve for supplying and discharging compressed air inside,
A cut valve provided in the middle of the air piping connecting the rear leveling valve, the air tank and the rear air spring, and openable and closable by a control signal output from a controller for vehicle height control,
The leveling control pause means may be constituted by the cut valve that shuts off supply and discharge of compressed air in the air tank with respect to the rear air spring by the rear leveling valve during the crouching control.

  According to the air suspension control device for a vehicle of the present invention, it is possible to achieve an excellent effect that the crouching control can be surely performed even if the height of the road surface on which the front wheel of the vehicle contacts is different on the left and right.

It is a flowchart which shows the Example of the air suspension control apparatus for vehicles of this invention. It is a whole schematic block diagram which shows the other Example of the air suspension control apparatus for vehicles of this invention. It is a whole schematic block diagram which shows an example of the conventional air suspension control apparatus for vehicles. It is a whole schematic block diagram which shows the other example of the conventional air suspension control apparatus for vehicles. It is the schematic which shows the state where the road surface in the right side of a vehicle is high as an example of the situation where the height of the road surface which the front wheel of a vehicle contacts differs significantly on right and left.

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

  FIG. 1 shows an embodiment of a vehicle air suspension control apparatus according to the present invention. The basic configuration is the same as that of the conventional apparatus shown in FIG. 3, but the features of this embodiment are shown in FIG. As shown, leveling control pause means for forcibly stopping leveling control during crouching control is provided. Incidentally, when the present invention is applied to a vehicle air suspension control device of the type shown in FIG. 3, the supply and discharge of compressed air in the air tank 6 with respect to the rear air spring 5 is performed by the rear vehicle height adjusting valve 10 during the crouching control. The leveling control pause means can be configured so as to be shut off.

  That is, it is detected whether or not the crouching switch 14 has been turned ON by the driver in step S1, and when the crouching switch 14 has been turned ON by the driver, the leveling control is forcibly stopped in step S2. To.

  After the leveling control is forcibly stopped in step S2, it is determined in step S3 whether the average value of the left and right vehicle heights 11a in the front portion of the vehicle 1 is within the reference range for crouching control. If the average value of the left and right vehicle heights 11a at the front is not within the reference range for crouching control, is the average value of the left and right vehicle heights 11a at the front of the vehicle 1 higher than the reference range for crouching control at step S4? If the average value of the left and right vehicle heights 11a at the front portion of the vehicle 1 is higher than the reference range for crouching control, the compressed air is discharged from the left and right front air springs 4 in step S5. Lower the front vehicle height 11a.

  Conversely, if the average value of the left and right vehicle heights 11a at the front of the vehicle 1 is lower than the reference range for crouching control, compressed air is supplied to the left and right front air springs 4 at step S6, and the vehicle at the front of the vehicle 1 is Increase the height 11a.

  After the operation of either step S5 or step S6 is performed, the process returns to step S3 to check again whether or not the average value of the left and right vehicle heights 11a in the front portion of the vehicle 1 is within the reference range for crouching control. If the average value of the left and right vehicle heights 11a at the front part of the vehicle 1 is within the reference range for crouching control, the vehicle height 11a at the front part of the vehicle 1 is held at that position, and passengers get on and off. To make it easier.

  Thereafter, it is detected in step S7 whether or not the crouching switch 14 has been turned off by the driver. If the crouching switch 14 has been turned off by the driver, the crouching control is terminated in step S8, and the vehicle 1 The vehicle height 11a at the front is returned to the original, and the leveling control is restarted in step S9.

  As described above, when the crouching switch 14 is turned on by the driver, the operation for forcibly stopping the leveling control in step S2 of FIG. 1 is performed by the control signal 10a output from the controller 13 shown in FIG. This is done by closing the vehicle height adjustment valve 10 and shutting off the supply / exhaust of compressed air in the air tank 6 to the rear air spring 5 by the rear vehicle height adjustment valve 10 so that crouching control is performed after step S3 in FIG. Then, for example, as shown in FIG. 5, the height of the road surface on which the front wheel 2 on the right side of the vehicle 1 contacts is significantly higher than that on the left side, and the rear wheel 3 of the vehicle 1 (not shown in FIG. 5). ) In the situation where the height of the road surface to be grounded is equal to the height of the road surface to which the front wheel 2 on the left side of the vehicle 1 is grounded, When the compressed air is discharged from the spring 4 at the same time, the bump stopper built in the right front air spring 4 comes into contact with the upper surface plate of the front air spring 4 and cannot further contract in the height direction. In a so-called rubber contact state, the compressed air is continuously discharged from the left front air spring 4, and in accordance with this operation, not only the vehicle height on the left side at the front of the vehicle 1 but also the vehicle on the left side at the rear of the vehicle 1. Even if it is determined that the height is low, the leveling control is forcibly stopped, so that the compressed air is not supplied to the left rear air spring 5 at the rear of the vehicle 1. The vehicle height on the left side can be lifted with the front air spring 4 on the right side in the rubber contact state as a fulcrum. No longer rise to, the vehicle 1 that, as the average value of the right and left vehicle height 11a at the front becomes high is avoided, and only crouching control is reliably performed alone.

  As a result, it is avoided that the crouching control and the leveling control are alternately performed so that the control does not converge, and the vertical movement of the vehicle body continues until all the compressed air in the air tank 6 is consumed. There will be no defects.

  Thus, even if the height of the road surface on which the front wheel 2 of the vehicle 1 contacts is different on the left and right, the crouching control can be reliably performed.

  In addition, when the present invention is applied to a vehicle air suspension control apparatus of the type shown in FIG. 4, as shown in FIG. 2, it is in the middle of an air pipe connecting the rear leveling valve 15, the air tank 6 and the rear air spring 5. Cut valves 16 and 17 that can be opened and closed by control signals 16a and 17a output from the controller 13 for controlling the vehicle height are provided, and the rear air spring 5 by the rear leveling valve 15 is provided by the cut valves 16 and 17 during the crouching control. The leveling control pause means can be configured so as to shut off the supply and discharge of the compressed air in the air tank 6 to the air.

  In the example shown in FIG. 2, when the crouching switch 14 is turned on by the driver, the operation for forcibly stopping the leveling control in step S <b> 2 of FIG. 1 is performed by the control signals 16 a and 17 a output from the controller 13. This is performed by closing the cut valves 16 and 17 and shutting off the supply and discharge of the compressed air in the air tank 6 with respect to the rear air spring 5 by the rear leveling valve 15 by the cut valves 16 and 17. When the crouching control is performed, for example, as shown in FIG. 5, the height of the road surface on which the front wheel 2 on the right side of the vehicle 1 contacts is significantly higher than that on the left side, and the rear wheel 3 (see FIG. 5). The height of the road surface to be grounded is equal to the height of the road surface to which the front wheel 2 on the left side of the vehicle 1 is grounded. In this situation, when compressed air is discharged from the left and right front air springs 4 at the front of the vehicle 1 at the same time, the bump stopper built in the right front air spring 4 comes into contact with the upper surface plate of the front air spring 4. As a result, the rubber is in a so-called rubber contact state that cannot be further contracted in the height direction, and the compressed air is continuously discharged from the front air spring 4 on the left side. In addition, even if it is determined that the vehicle height on the left side at the rear portion of the vehicle 1 is also low, the leveling control is forcibly stopped, so that compressed air is applied to the left rear air spring 5 at the rear portion of the vehicle 1. It is not supplied, and the vehicle height on the left side at the front of the vehicle 1 is the front air on the right side in the rubber contact state. It is avoided that the vehicle rises so that it can be lifted with the pulling 4 as a fulcrum, and the average value of the left and right vehicle heights 11a at the front portion of the vehicle 1 is avoided, and only the crouching control is performed reliably. It becomes.

  As a result, even in the example shown in FIG. 2, it is avoided that the crouching control and the leveling control are alternately performed so that the control does not converge, and the vertical movement of the vehicle body is continued until all the compressed air in the air tank 6 is consumed. Problems such as continuing will not occur.

  Thus, in the case of the example shown in FIG. 2, as in the case of the examples shown in FIGS. 1 and 3, the crouching control can be reliably performed even if the height of the road surface on which the front wheel 2 of the vehicle 1 contacts is different on the left and right. .

  The vehicle air suspension control device of the present invention is not limited to the above-described embodiment, and can be applied to a vehicle whose front suspension is rigid (axle suspension). Of course, only one sensor may be provided on the front shaft side, and various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Front wheel 3 Rear wheel 4 Front air spring 5 Rear air spring 6 Air tank 8 Front vehicle height adjustment valve 8a Control signal 10 Rear vehicle height adjustment valve 10a Control signal 11 Front vehicle height sensor 11a Vehicle height 12 Rear vehicle height sensor 12a Vehicle High 13 Controller 14 Crouching switch

Claims (3)

A front air spring that is arranged to support the front wheels of the vehicle and supplies and discharges compressed air in the air tank, and a rear air that is arranged to support the rear wheels of the vehicle and supplies and discharges compressed air in the air tanks The front part of the vehicle is equipped with a spring, and controls the leveling of the vehicle body in parallel to the axle by independently maintaining the left and right vehicle heights at a constant height. In a vehicle air suspension control device that performs crouching control to lower the vehicle height,
A vehicle air suspension control apparatus comprising leveling control suspension means for forcibly stopping leveling control during the crouching control. A rear vehicle height sensor for detecting left and right vehicle heights at the rear of the vehicle;
A rear vehicle height adjustment valve for supplying and discharging compressed air in the air tank to and from the rear air spring by a control signal output from a vehicle height control controller based on the vehicle height detected by the rear vehicle height sensor;
2. The vehicle air suspension control device according to claim 1, wherein the leveling control suspension means is configured by the rear vehicle height adjustment valve that shuts off supply and discharge of compressed air in an air tank with respect to the rear air spring during the crouching control. A rear leveling valve that detects a change in left and right vehicle heights at the rear of the vehicle by tilting a lever protruding from the valve body, and supplies and discharges compressed air in an air tank to and from the rear air spring in conjunction with the tilting of the lever; ,
A cut valve provided in the middle of the air piping connecting the rear leveling valve, the air tank and the rear air spring, and openable and closable by a control signal output from a controller for vehicle height control,
2. The vehicle air suspension control device according to claim 1, wherein the leveling control suspension unit is configured by the cut valve that blocks supply and discharge of compressed air in an air tank to and from the rear air spring by the rear leveling valve during the crouching control.

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