JPH05169956A - Air suspension used for rear double axle type vehicle - Google Patents

Abstract

PURPOSE:To raise slip limit so as to insure running on a snowy road or a muddy road. CONSTITUTION:An electromagnetic/pneumatic pressure changeover device 16 is operated for changeover with a controller 17 to charge or discharge compressed air in/from air springs 11, 12, 13, 14 of a drive axle and an idler axle, vehicle floor height is kept constant at ordinary running, and when the vehicle speed is under a prescribed value on a snowy road or a muddy road and rotation difference between a drive wheel and an idler wheel is over a prescribed value continuously for a prescribed time, the changeover device 16 is operated for changeover with the controller 17, the inner pressure of the air springs 11, 12 of the drive axle us properly raised from the steady pressure, simultaneously the inner pressure of the air springs 13, 14 of the idler axle is properly reduced from the steady pressure, so as to concentrate load on the drive axle and raise the slip limit of the drive wheels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air suspension used for a rear two-axle vehicle.

[0002]

[Background Art] In the air suspension of two-axle trucks and buses, load distribution has been made by an equalizer mechanism, but the load distribution is always constant, and the slip limit becomes low on snowy roads and mud roads. In the snowy road and the mud road, it may be difficult to drive.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an air suspension used for a rear two-axle vehicle in which a slip limit is increased and traveling is ensured in a snowy road, a muddy road or the like.

[0004]

[Means corresponding to the problem and its action]
The drive axle air that supports the drive axle behind the frame
A spring, an idler axle air spring that supports the idler axle adjacent to the drive axle behind the frame, compressed air is supplied to the drive axle and the idler axle air spring from an air pressure source, and the drive axle and A signal is input from the electromagnetic air pressure switching device that discharges compressed air from the idle axle air spring, the vehicle speed sensor, the drive wheel rotation sensor, and the idle wheel rotation sensor, and normally switches to the electromagnetic air pressure switching device during normal traveling. When the drive axle and the idle axle air springs are operated to communicate with each other, and the vehicle speed is equal to or lower than a predetermined value and the rotation difference between the drive wheel and the idle wheel exceeds a predetermined value and continues for a predetermined time, The electromagnetic air pressure switching device is switched to increase the internal pressure of the drive axle air spring from the steady pressure, and at the same time, The internal pressure of the idler axles air spring and a controller to reduce appropriately than the steady pressure,
When the drive wheels start to slip on snowy roads, mud roads, etc., the shared load of the drive axle is increased, and at the same time, the shared load of the idle axle is reduced to increase the slip limit and ensure traveling.

[0005]

DESCRIPTION OF SPECIFIC EXAMPLES Specific specified examples of the air suspension used in the two-axle vehicle after the present invention will be described with reference to the drawings. 1 and 2 show a tenth embodiment of an air suspension used in a rear twin-axle vehicle of the present invention applied to a rear twin-axle truck. The air suspension 10 includes a pair of drive axle air springs 11 and 12 supporting a drive axle behind the frame and an idle axle adjacent to the drive axle behind the frame in the truck. A pair of idle axle air springs 13, 14 and compressed air are supplied from the air pressure source 15 to the drive axles and idle axle air springs 11, 12, 13, 14 to drive the drive axles and idle axle air springs 11. , 12, 1
Electromagnetic air pressure switching device 16 for discharging compressed air from 3, 14, vehicle speed sensor 35, drive wheel rotation sensor 36, idle wheel rotation sensor 37, drive axle pressure sensor 38, idle axle pressure sensor 39, and height sensor 40. The input side is composed of a controller 17 in which the electromagnetic air pressure switching device 16 is electrically connected to the output side, and the pneumatic source 15 is an air driven by a diesel engine mounted on the truck. Compressor 1
8 and a reservoir tank 19 connected to the air compressor 18 by a tank pipe 21, and a pressure regulator 20 is arranged in a pressure extraction pipe 22 of the air compressor 18.
It is configured to operate and stop the air compressor 18 depending on the pressure of the regulator 20. Of course, in the air pressure source 15, a check valve 23 and a water trap 24 are arranged in the tank pipe 21.

The drive axle air springs 11, 12
Is connected to its reservoir tank 19 by a main pipe, while its idle axle air springs 13, 14 are connected to a branch pipe 26 branched from the middle of its main pipe 25, and its drive axle and The idle axle air springs 11, 12, 13, 14 are connected to each other by a pressure balancing pipe 27 connected between a main pipe 25 and a branch pipe 26 thereof.

The electromagnetic air pressure switching device 16 comprises an electromagnetic air supply valve 28, an electromagnetic shutoff valve 29, and an electromagnetic air supply / exhaust valve 30, and the electromagnetic air supply valve 28 is a normally closed two-way control valve. The solenoid coil 31 is electrically connected to the output side of the controller 17 disposed in the main pipe 25 at the upstream side of the point where the branch pipe 26 is connected.

As the electromagnetic shut-off valve 29, a normally open type two-way control valve is used, which is arranged in the pressure balance pipe 27 and electrically connects a solenoid coil 32 to the output side of the controller 17, while As the electromagnetic supply / exhaust valve 30, a three-way control valve is used, which is arranged in the branch pipe 26 and is connected to the output side of the controller 17 by the solenoid coil 3.
3,34 were electrically connected.

The controller 17 is composed of an input and output circuit, an arithmetic circuit, a memory circuit, a control circuit, a power circuit, etc., and has a vehicle speed sensor 35, a drive wheel rotation sensor 36, an idle wheel rotation sensor 37, a drive axle. The pressure sensor 38, the idle axle pressure sensor 39, and the height sensor 40 are provided with input circuits thereof, and the solenoid air supply valve 28, solenoid shutoff valve 29, and solenoid of the solenoid supply / exhaust valve 30 are connected.
The output circuits were electrically connected to the coils 31, 32, 33, and 34, respectively, and the power supply circuit shared the battery of the truck.

Further, the controller 17 has a vehicle speed sensor 35, a drive wheel rotation sensor 36, an idle wheel rotation sensor 37, a drive axle pressure sensor 38, and an idle axle pressure sensor 3.
9 and a signal from the height sensor 40, and when the truck is traveling normally, the electromagnetic air supply valve 28, the electromagnetic cutoff valve 29, and the electromagnetic supply / exhaust valve 30 are switched by the valve. The compressed air is replenished to the bellows of the drive axle and the idle axle air springs 11, 12, 13, and 14, and the air pressure of the bellows of the drive axle and the idle axle air springs 11, 12, 13, 14 is increased. Adjust to maintain the drive axle and idle axle air springs 11, 12, 13, 14 at a steady height, and when the truck runs on snow, mud, etc., causing the drive wheels to slip. That is, when the vehicle speed is equal to or lower than a predetermined value and the rotation difference between the drive wheel and the idle wheel exceeds a predetermined value and continues for a predetermined time, the electromagnetic air supply valve 28, the electromagnetic cutoff valve 29, Beauty, the drive axle air springs 1 by performing the valve switching operation the solenoid supply and exhaust valve 30
Compressed air is supplied to the bellows 1 and 12 to appropriately raise the internal pressure of the bellows of the drive axle air springs 11 and 12 above the steady pressure, and at the same time, the compressed air from the bellows of the idle axle air springs 13 and 14 is compressed. Is partially discharged to lower the inner pressure of the bellows of the idle axle air springs 13 and 14 appropriately below the steady pressure, and the control operation is performed at the point where the shared load of the drive axle and idle axle is changed.

The vehicle speed sensor 35 is a rotation speed sensor for detecting the traveling speed of the truck and is arranged on the output shaft of the transmission mounted on the truck. The drive wheel rotation sensor 36 and the idle wheel rotation sensor 37 of the vehicle are mounted on the output shaft of the transmission.
Is a rotation speed sensor for detecting the rotation speeds of the corresponding drive axle and idle axle, and the drive axle pressure sensor 3
8 and the idle axle pressure sensor 39 are strain gauge pressure sensors that detect the internal pressure of the corresponding drive axle and bellows of the idle axle air springs 11, 12, 13, 14 and their height sensors. 40
Was positioned between its frame and its drive axle to detect the height of its drive axle air springs 11,12.

Next, the air
To explain the operation of the suspension 10 in relation to the running condition of the truck, when the truck is now running on a paved road, the controller 17 causes the sensors 35, 36, 37, 38, 39 to detect them. , 40, and the electromagnetic air supply valve 28, the electromagnetic cutoff valve 29, and the solenoid coils 31, 3 of the electromagnetic supply / exhaust valve 30.
It controls the output current flowing through 2, 33 and 34. Of course, in this case, since the truck is traveling normally and there is no difference in rotation between the drive wheel and the idle wheel, the electromagnetic air supply valve 28, the electromagnetic cutoff valve 29, and the electromagnetic supply valve are not generated. The exhaust valve 30 is placed in the state shown in FIG.

When the drive axle and idle axle air springs fall below a steady height in such a running condition of the truck, the controller 17 responds to the electromagnetic feed in response to a signal input from the height sensor 40. The output currents flowing through the solenoid coils 31, 33, and 34 of the air valve 28 and the electromagnetic supply / exhaust valve 30 are controlled so that the electromagnetic supply valve 28 and the electromagnetic supply / exhaust valve 31 perform a valve switching operation to connect the outlet side connection port. From the reservoir tank 19 to the air springs 11, 1 via the main pipe 25 and the branch pipe 26.
The compressed air is supplied to the bellows 2, 13, and 14 to increase the air pressure.

In this way, when the compressed air is replenished and the air pressure is increased, the air springs 11 and 1 are
When the height of 2, 13, 14 is restored and reaches a steady height, the controller 17 of the height sensor 40
Signal is input to control the output current flowing through the solenoid coils 31, 33, 34 of the electromagnetic air supply valve 28 and the electromagnetic air supply / exhaust valve 30 to switch the electromagnetic air supply valve 28 and the electromagnetic air supply / exhaust valve 30. The inlet side connection port and the outlet side connection port are closed by performing an operation, and the bellows of the air springs 11, 12, 13, 14 are replenished from the reservoir tank 19 through the main pipe 25 and the branch pipe 26. That compressed air is stopped, so that the air springs 11, 12, 13, 14 are maintained at a steady height.

Further, the truck travels on a snowy road, its driving wheels are slipped, the vehicle speed is reduced below a predetermined value, and the rotational difference between the driving wheel and the idle wheel exceeds a predetermined value for a predetermined time. When continued, the controller 17
Ignores the signal from the height sensor 40 and responds to signals input from the vehicle speed sensor 35, the drive wheel rotation sensor 36, the idle wheel rotation sensor 37, the drive axle pressure sensor 38, and the idle axle pressure sensor 39. First, the output current flowing through the solenoid coil 32 of the electromagnetic cutoff valve 29 is controlled, and the electromagnetic cutoff valve 29 is caused to perform a valve switching operation to close the inlet side connection port and the outlet side connection port. The electromagnetic shutoff valve 29 is closed.

At the same time, the controller 17 controls the solenoids of the electromagnetic air supply valve 28 and the electromagnetic air supply / exhaust valve 30.
The output currents flowing through the coils 31, 33, 34 are controlled, and the electromagnetic air supply valve 28 and the electromagnetic air supply / exhaust valve 30 are caused to perform a valve switching operation. Connect to the inlet side connection, and
In the electromagnetic supply / exhaust valve 30, the outlet side connection port is connected to the exhaust side connection port. As a result, its drive axle air
In the springs 11 and 12, compressed air passes from the reservoir tank 19 through the main pipe 25 to the air
The bellows of the springs 11 and 12 begin to be replenished, and at the same time, in the idle axle air springs 13 and 14, compressed air passes through the downstream side of the branch pipe 26 to the atmosphere from the bellows of the air springs 13 and 14. It begins to be discharged. That is, in this case, the electromagnetic air supply valve 2
8, the electromagnetic shutoff valve 29, and the electromagnetic supply / exhaust valve 30 are placed in the state shown in FIG.

In this way, the compressed air is replenished to the bellows of the air springs 11 and 12 so that the air
In the bellows of the springs 11 and 12, the internal pressure appropriately rises above the steady pressure, and at the same time, the compressed air is partially withdrawn from the bellows of the air springs 13 and 14, and the internal pressure of the bellows of the air springs 13 and 14 increases. Since the pressure falls appropriately below the steady pressure, the controller 17
Is the drive axle and idle axle pressure sensors 38, 39
The solenoid coils 31, 33 of the electromagnetic air supply valve 28 and the electromagnetic air supply / exhaust valve 30 corresponding to the signal input from
34 controls the output current flowing through the solenoid valve 34 and causes the electromagnetic air supply valve 28 and the electromagnetic air supply / exhaust valve 30 to perform a valve switching operation so that the electromagnetic air supply valve 28 and the electromagnetic air supply / exhaust valve 30 have their inlet side connection port and outlet side. Close the connection port. as a result,
The drive axle has a shared load increased, while the idle axle has a reduced shared load, so that the shared load is varied between the drive axle and the idle axle, with which: The slip limit of the drive wheels was increased and the truck was safely driven on the snow.

FIG. 3 shows another embodiment 50 of the air suspension used in the rear twin-axle vehicle of the present invention applied to the rear twin-axle truck. In this air suspension 50, the electromagnetic air pressure switching device 16 used in the above-mentioned air suspension 10 is modified, and accordingly, the pressure balancing pipe 27 is omitted and the pneumatic circuit is simplified. Along with the deformation of the electromagnetic air pressure switching device 16, a height, which is arranged between the frame and the idle axle and detects the height of the idle axle air springs 13 and 14,
Sensor 58 was additionally used. Of course, in this air suspension 50, the pair of drive axle air springs, the pair of drive axle air springs, the air pressure source, the controller, the main pipe, and the branch pipe correspond to those of the air suspension 10. Therefore, they are denoted by the same reference numerals and detailed description thereof is omitted.

In this air suspension 50, the electromagnetic air pressure switching device 51 includes two electromagnetic air supply / exhaust valves 52, 5.
As the electromagnetic supply / exhaust valves 52 and 53, a three-way control valve which is the electromagnetic supply / exhaust valve 30 of the air suspension 10 is used, and one electromagnetic supply / exhaust valve 52 is arranged in the main pipe 25. Electrically connect the solenoid coils 54 and 55 to the output side of the controller 17, and
The other electromagnetic supply / exhaust valve 53 is arranged in the branch pipe 26, and the solenoid coils 56 and 57 are electrically connected to the output side of the controller 17.

The air suspension 50 having such a configuration is operated in the same manner as the air suspension 10 described above, depending on the traveling state of the truck. Therefore, detailed description of the operation of the air suspension 50 is omitted.

FIG. 4 shows still another embodiment 60 of the air suspension used in the rear twin-axle vehicle of the present invention applied to the rear twin-axle truck. This air suspension 60 is the same as the air suspension 10 described above.
The electromagnetic air pressure switching device 16 used in the above is modified, and accordingly, the pressure balancing pipe 27 is omitted to simplify the pneumatic circuit, and the idle axle air spring is smoothly supplied with compressed air. I just made it possible. Of course, with this air suspension 60,
Since the pair of drive axle air springs, the pair of idle axle air springs, the air pressure source, the controller, the main pipe, and the branch pipe correspond to those of the air suspension 10, they are designated by the same reference numerals. Detailed descriptions thereof are omitted.

In this air suspension 60, the electromagnetic air pressure switching device 61 comprises an electromagnetic air supply valve 28, an electromagnetic shutoff valve 62 with a variable throttle, and an electromagnetic exhaust valve 63.
In the case of the air suspension 10 described above, the electromagnetic air supply valve 28 is also arranged in the main pipe 25 upstream of the point where the branch pipe 26 is connected, and the solenoid is provided on the output side of the controller 17. -The coil 31 was electrically connected.

On the other hand, as the electromagnetic shut-off valve 62, a normally open type two-way control valve with a variable throttle is used.
A solenoid coil 64 is electrically connected to the output side of the controller 17, and a normally-closed two-way control valve is used as the electromagnetic exhaust valve 63 of the electromagnetic exhaust valve 63. An exhaust pipe 66 was connected to the branch pipe 26, and a solenoid coil 65 was electrically connected to the output side of the controller 17.

The air suspension 60 having such a structure operates in the same manner as the air suspension 10 described above, depending on the traveling state of the truck. Therefore, detailed description of the operation of the air suspension 60 is omitted.

As is apparent from the embodiments of the present invention described above with reference to the drawings, those skilled in the art to which the present invention pertains have a general knowledge of the present invention. In order to achieve the object of the invention, it is easy to obtain a mode that is derived from the technical essence of the invention, which is essential to the formation of the invention and is the nature of the invention, and which is objectively recognized as being internal. Is embodied in.

[0026]

Benefits of the Invention As will be understood from the above, the air suspension used in the rear two-axle type vehicle of the present invention is an electromagnetic pneumatic system for supplying and discharging compressed air from a pneumatic source to a drive axle and an idle axle air spring. The switching device is controlled by the controller, and the controller inputs signals from the vehicle speed sensor, the drive wheel rotation sensor, and the idle wheel rotation sensor, and in normal traveling, causes the electromagnetic pneumatic pressure switching device to normally perform switching operation. When the drive axle and the idle axle air springs are in communication with each other, and the vehicle speed is below a predetermined value and the rotation difference between the drive wheel and the idle wheel exceeds a predetermined value and continues for a predetermined time, electromagnetic air pressure switching is performed. The internal pressure of the drive axle air spring is appropriately raised from the steady pressure by switching to the device, and at the same time, the idle axle air spring Since the internal pressure of the vehicle is appropriately lowered from the steady pressure, the air suspension used for the two-axle vehicle after the present invention keeps the vehicle height normally at the time of normal traveling, and also prevents snow and mud roads. When traveling, the shared load of the drive axle is increased, and at the same time, the shared load of the idle axle is reduced, the slip limit of the drive wheels is increased, and traveling is ensured. It is possible to easily escape from the location where was accumulated, which is very useful and practical for large vehicles.

[Brief description of drawings]

FIG. 1 is a schematic view showing a specific example of an air suspension used in a rear biaxial vehicle of the present invention applied to a rear biaxial truck in a normal state.

FIG. 2 is a schematic diagram showing the air suspension shown in FIG. 1 in a state where the air suspension has started to operate.

FIG. 3 is a schematic view showing another specific example of an air suspension used in a rear biaxial vehicle of the present invention applied to a rear biaxial truck in a normal state.

FIG. 4 is a schematic view showing still another specific example of an air suspension used in a rear biaxial vehicle of the present invention applied to a rear biaxial truck in a normal state.

[Explanation of symbols]

 11 Drive Axle Air Spring 12 Drive Axle Air Spring 13 Idler Axle Air Spring 14 Idler Axle Air Spring 16 Electromagnetic Air Pressure Switching Device 17 Controller 25 Main Pipe 26 Branch Pipe 27 Pressure Balance Pipe 28 Electromagnetic Air Supply Valve 29 Electromagnetic Shutoff Valve 30 Electromagnetic supply / exhaust valve

Claims (1)

[Claims] 1. A drive axle air spring for supporting a drive axle behind a frame, a idle axle air spring for supporting a drive axle adjacent to the drive axle behind the frame, and a drive from an air pressure source. An electromagnetic air pressure switching device that supplies compressed air to the axle and the idle axle air spring and discharges compressed air from the drive axle and idle axle air spring, and a vehicle speed sensor, a drive wheel rotation sensor, and an idle wheel rotation sensor. When a signal is input and the vehicle normally travels, the electromagnetic air pressure switching device is normally switched to communicate the drive axle and idle axle air springs with each other, and when the vehicle speed is less than a predetermined value, the drive wheels and idle wheels are driven. If the rotation difference of the above exceeds a predetermined value and continues for a predetermined time, the electromagnetic pneumatic pressure switching device is caused to perform a switching operation to drive it. The inner pressure of the moving axle air spring is appropriately raised above the steady pressure, and at the same time, the idle axle air spring
An air suspension used for a rear two-axle vehicle that includes a controller that appropriately lowers the internal pressure of the spring from a steady pressure.