JPH0617604Y2 - Device for maintaining and adjusting the vehicle body load on the wheel axle - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The vehicle body load applied to the wheel axles of a vehicle is changed to improve the running performance on a mud or snowy road.

(Prior Art) A vehicle having three or more axes such as a large truck and a bus, that is, a large truck 1 as shown in FIG. 1, has a front wheel shaft 2, a rear front wheel shaft 3 and a rear rear wheel shaft 4 at right angles to the vehicle traveling direction. The front and rear wheel axles 3 are provided with driving power from the vehicle-mounted engine.
There is a vehicle that you are running. Therefore, in such a vehicle, the vehicle body load is applied to the rear wheel portion by the rear front wheel shaft 3 and the rear rear wheel shaft 4 to support the vehicle body 7.

However, the driving force F of the vehicle is the product of the friction coefficient μ between the tire 5 and the road surface 6 and the load P applied to the rear front wheel shaft 3.

Therefore, the driving force F may be smaller than the vehicle running resistance force F ′ on a low μ road such as a muddy area or a snowy road where the friction coefficient μ is small, which causes a problem that the vehicle cannot run.

(Object of the Invention) When the vehicle as described above enters a low μ road, the present invention moves a part or most of the vehicle body load applied to the rear rear wheel shaft 4 to the rear front wheel shaft 3 which is a drive wheel shaft, Load P on the rear front wheel axle 3
Is increased to increase the driving force F, and the vehicle is allowed to escape from the mud and snowy roads.

(Structure of the Invention) In the present application, a rear axle is composed of a plurality of axles including a drive wheel shaft and a non-drive wheel shaft that suspends a vehicle body with a fluid suspension, and the fluid suspension of the non-drive wheel shaft is decompressed. In a vehicle in which the vehicle body supporting load of the drive wheel axle is increased, a pressure reducing valve connected to the fluid suspension of the non-drive wheel axle and the fluid pressure suspension valve of the non-drive wheel axle are operated by operating the pressure reducing valve. And a pressure inside the fluid suspension mounted on the drive wheel shaft is set to a predetermined value corresponding to the vehicle body supporting load applied to the drive wheel shaft in accordance with the operation of the set switch. The pressure detection switch that detects when the maximum pressure has been reached, the first contact connected to the power supply through the set switch, and the pressure reducing valve A second contact that is connected through an electromagnetic coil that operates a pressure valve and is normally connected to the first contact, and a first contact that is connected to the pressure detection switch and is energized by the detection operation of the pressure detection switch to generate an exciting force. And a relay having an exciting coil for disconnecting the second contact and a third contact connected to the exciting coil and connected to the first contact by the exciting force of the exciting coil to energize the exciting coil. A vehicle load adjusting operation holding device for a wheel shaft, which is characterized by being provided.

According to the present application, as the vehicle travels, the pressure in the fluid suspension of the drive wheel shaft fluctuates, and the pressure detection switch turns on.
Even if 0FF is repeated, since the connection between the first contact and the third contact of the relay is held by the exciting coil, the exhaust valve for reducing the pressure in the fluid suspension of the non-driving wheel shaft should be kept closed. Has the effect of being able to.

More specifically, when the manually operated set switch is operated, the current from the power source flows to the electromagnetic coil of the pressure reducing valve via the first and second contacts of the set switch and the relay, and the pressure reducing valve is actuated so that it is not driven. Fluid in the wheel axle fluid suspension is expelled. As a result, the pressure in the fluid suspension of the drive wheel shaft increases, and the vehicle body supporting load of the drive wheel shaft increases.

When the pressure detection switch detects that the pressure in the fluid suspension of the drive wheel shaft has reached the predetermined maximum pressure, the exciting coil excites and the exciting force disconnects the first contact and the second contact. As a result, the power supply to the electromagnetic coil of the pressure reducing valve is cut off and the pressure reducing valve stops the pressure reducing operation, so that the discharge of the fluid in the fluid suspension of the non-driven wheel shaft is stopped.

Further, when the connection between the first contact and the second contact is broken due to the excitation of the exciting coil, the first contact is connected to the third contact connected to the exciting coil. Is supplied to the exciting coil via the set switch and the first third contact of the relay, and once the exciting coil is excited and the first contact and the third contact are connected, the detection state of the pressure detection switch is set. Regardless, the connection between the first contact and the third contact is maintained. Therefore, the pressure reducing valve is maintained in the closed state, the pressure in the fluid suspension of the non-driving wheel shaft is maintained in the pressure reducing state at this time, and the pressure in the fluid suspension of the driving wheel shaft reaches the predetermined maximum pressure. Will be retained.

Therefore, according to the present invention, when the manually operated set switch is operated, the pressure in the fluid suspension of the drive wheel shaft can be raised to a predetermined maximum pressure and the state can be maintained, and in a low μ road or the like. The driving force of the vehicle can be reliably ensured.

(Example) It demonstrates in detail along with drawing. FIG. 2 shows an embodiment of the present invention. Reference numerals 2L and 2R are provided on the front wheel shaft 2 shown in FIG. 1 and are arranged substantially symmetrically with respect to the vehicle center to suspend the vehicle body 7. It is an air suspension that is a fluid suspension. Reference numerals 8L and 8R denote a supply valve 10 disposed downstream of the air tank 9 which is a fluid pressure source.
It is a leveling valve interposed in a passage that communicates with the air suspension 2L or 2R. When the air suspensions 2L and 2R are compressed by the increase in the load of the vehicle body 7 and the gap between the vehicle body 7 and the front wheel shaft 2 becomes smaller than the set value, the leveling valves 8L and 8R are supplied from the air tank 9 to the air suspension 2L or 2R. Air is supplied to inflate the air suspensions 2L and 2R to maintain the gap between the vehicle body 7 and the front wheel shaft 2 at a set value.

When the gap between the vehicle body 7 and the front wheel shaft 2 becomes larger than the set value, the air of the air suspensions 2L and 2R is discharged from the leveling valve 8L or 8R into the atmosphere to keep the gap at the set value. Reference numeral 11 is a leveling valve for the rear wheel shaft (collective term for the rear front wheel shaft 3 and the rear rear wheel shaft 4), and is substantially the same in structure and operation as the leveling valves 8L and 8R arranged on the front wheel shaft 2.

Reference numerals 3LF and 3LR are air suspensions arranged on the left side of the rear front wheel shaft 3, 3RF and 3RR are on the right side of the rear front wheel shaft 3, 4L is on the left side of the rear rear wheel shaft 4 and 4R is on the right side of the rear rear wheel shaft 4. is there.

Reference numeral 12 is air suspension 3LF, 3LR, 3R
This is a normally open type pressure switch that is turned on when the air pressures of F and 3RR exceed a set value. Reference numeral 13 is arranged in the driver's seat (not shown), and the pilot lamp 1
This is a solenoid valve that operates by energizing the power source 16 by turning on the set switch 14 having the built-in 5 switch. The solenoid valve 13 is a first port A communicating with the air tank 9 via the leveling valve 11 and the supply valve 10, a second port B communicating with the air suspensions 4L and 4R, an air suspension 4L, Each has a third port C that communicates with the pressure reducing valve 17 that releases the air in the 4R to the atmosphere. Further, the solenoid valve 13 communicates with B-C when energized is ON and with AB when energized is OFF.
When the set switch 14 is turned on, the pressure reducing valve 17 is operated by energizing the electromagnetic coil 17 'for operating the pressure reducing valve 17 via a self-holding relay 18 described later. The pressure reducing valve 17
When the energization is ON, the ports D-E are energized and the ports F-E communicate with each other.

The self-holding relay 18 is provided on the power contact H that is the first contact, the contact K that is the second contact connected to the pressure reducing valve 17, and the meter plate 19 at the driver's seat, and the air suspension 4L of the rear rear wheel shaft 4 is provided. , 4R are constituted by a pilot lamp 20 for indicating that the pressure is reduced and a contact J which is a third contact connected to an exciting coil 21 for keeping the pressure reducing valve 17 from being energized, and a spring (not shown) is always provided. The contacts H-K are connected by force.

A reference numeral 22 receives a signal from the speed sensor 23, and when the vehicle 1 reaches a vehicle speed higher than a prescribed value (15 km / H in this embodiment), the current from the speed control 24 shuts off the power supply circuit of this device. It is a safety relay and is normally a closed circuit. Reference numeral 27 is a throttle valve for controlling the air pressure of the air suspensions 4R, 4L so as not to drop suddenly.

The operation of this device will be described. When the vehicle 1 enters a muddy area or a snowy road, when the driver turns on the set switch 14, the current flows from the power source 16 → the safety relay 22 → the set switch 14 → * 1, * 2, * 3 * 1. Lamp lit * 2 Operate solenoid valve 13 to communicate B-C * 3 Self-holding relay contact H → contact K → Operate pressure reducing valve 17 to communicate D-E.

The air in the air suspensions 4L and 4R of the rear rear wheel shaft 4 is discharged into the atmosphere through B-C of the solenoid valve 13 and D-E of the pressure reducing valve 17. Therefore, the air pressure in the air suspensions 4L and 4R decreases, and the vehicle load on the rear rear wheel axle 4 decreases. Therefore, the decrease in the vehicle body load is due to the air suspension 3LF, 3LR, 3 of the rear front wheel shaft 3.
When moving to RF and 3RR, the air suspension is compressed and the gap between the vehicle body 7 and the rear front wheel shaft 3 becomes smaller,
The leveling valve 11 operates to supply the high pressure air in the air tank 9 to the air suspension 3LF, 3LR, 3RF.
And 3RR while supplying to 3RR, it operates so that the gap between the vehicle body 7 and the rear front wheel shaft 3 becomes a set value.

When the vehicle load of the rear-rear wheel shaft 4 moves to the rear-rear wheel shaft 3 by a set amount, the moving amount is changed by the air springs 3LF, 3LR, 3
The change is detected by the change in the air pressure in RF and 3RR (in this case, the air pressure becomes higher). That is, the pressure switch 12 includes the air springs 3LF, 3LR, 3RF, and 3 described above.
When the air pressure in RR reaches the set value, the switch turns on.

Then, the current is set switch 14 → pressure switch 12 →
It flows into the exciting coil 21 of the self-holding relay 18, the contact of the self-holding relay 18 changes from HK to HJ, the pressure reducing valve 17 is de-energized, and the port FE of the pressure reducing valve 17 communicates with the port. Air suspension 4 because D is blocked
The air discharge in R and 4L is stopped, and the movement of the vehicle body load from the rear rear wheel shaft 4 to the rear front wheel shaft 3 is completed.

On the other hand, the current of the self-holding relay 18 is 1
4 → contact H of self-holding relay 18 → contact J * 1, * 2 * 1 Pilot lamp 20 of meter cluster 19 * 2 Diode 25 → excitation coil 21 flows in this order, and keeps decompression valve 17 energized.

Further, the self-holding relay 18 does not energize the pressure reducing valve 17 by the action of the exciting coil 2 even if the pressure in the air suspensions 3LF, 3LR, 3RF and 3RR fluctuates due to the movement of the vehicle and the pressure switch 12 repeatedly turns on and off. It was done like this. Furthermore, when the vehicle moves out of the muddy ground or the like and then shifts to steady-state running, the driver does not restore the transition of the vehicle body load of the wheel shaft, that is, the vehicle body load is transferred from the rear front wheel shaft 3 to the rear rear wheel shaft 4. Unless the amount moved by the operation is returned, the strength safety factor of the rear front wheel shaft 3 is lowered. The speed control 24 energizes the exciting coil 26 of the safety relay 22 by a signal from the speed sensor 23, interrupts the circuit which is normally a closed contact by the exciting force of the exciting coil 26, and disconnects the energization of the solenoid valve 13. , Port A of solenoid valve 13
-B is made to connect and wheel axle load is returned to the original.

Further, the operation mode of the speed control 24 is, as shown in FIG. 3, when the vehicle speed is increasing, it is turned on between 0 and 15 km / h, that is, when the safety relay is closed and the vehicle speed decelerates from 15 km / h or more. Is set to ON only when it reaches 4km / h. In this embodiment, the fluid is air, but even if the air and the liquid are used together and the air pressure in the air suspension is changed by the movement of the liquid, it is possible to obtain substantially the same effect as this embodiment. .

According to this embodiment, by decompressing the air of the air suspension mounted on a part of the wheel shaft of a vehicle having a plurality of wheel shafts suspending the vehicle body by the air suspension, It is possible to increase the driving force of the vehicle by increasing the vehicle body load force, and at the same time, the air suspension 3 may be changed due to the fluctuation of the vehicle during the escape from the mud.
Even if the air pressure in the LF, 3LR, 3RF and 3RR fluctuates and the pressure switch 12 is turned on and off, the air of the air suspensions 4L and 4R is held so as not to be further reduced in pressure.

(Effect of the Invention) According to the present invention, since the pressure in the fluid suspension of the drive wheel shaft can be raised to a predetermined maximum pressure, for example, this predetermined maximum pressure is set to a value corresponding to the maximum load specified by law. If set, the load on the drive wheel axle can be easily increased to the maximum load specified by law, and drive performance can be reliably obtained with simple operation to the extent that it can be used to drive on low-μ roads. There is an advantage that the property can be easily improved.

Further, since the pressure inside the fluid suspension of the drive wheel shaft can be maintained at a predetermined maximum pressure by the relay having the first to third contacts and the exciting coil and the pressure detection switch, the structure is simple and practical. There are also excellent advantages.

[Brief description of drawings]

FIG. 1 is a side view of the entire vehicle, FIG. 2 is an air and electric circuit diagram according to the present embodiment, and FIG. 3 is a speed control operation mode. 2L, 2R, 3LF, 3LR, 3RF, 3RR, 4L,
4R: Air suspension 3: Rear front wheel shaft 4: Rear rear wheel shaft 11: Leveling valve 12: Pressure switch 13: Solenoid valve, 17: Pressure reducing valve 18: Self-holding relay, 22: Safety relay

Claims (1)

[Scope of utility model registration request] 1. A rear axle is composed of a plurality of axles including a drive wheel axle and a non-drive wheel axle that suspends a vehicle body with a fluid suspension, and the fluid suspension of the non-drive wheel axle is decompressed to drive the vehicle. In a vehicle in which the vehicle body supporting load of the wheel axle is increased, the pressure reducing valve connected to the fluid suspension of the non-driving wheel axle and the pressure reducing valve are operated to reduce the pressure in the fluid suspension of the non-drive wheel axle. The pressure in the fluid suspension mounted on the drive wheel shaft and the manually operated set switch to reduce the pressure is set to a predetermined maximum pressure corresponding to the vehicle body supporting load applied to the drive wheel shaft in accordance with the operation of the set switch. The pressure reducing switch that detects when the pressure is reached, the first contact connected to the power supply through the set switch, and the pressure reducing valve are operated. A second contact that is connected through an electromagnetic coil and is normally connected to the first contact, and a second contact that is connected to the pressure detection switch and is energized by the detection operation of the pressure detection switch and is excited by the magnetic force. And a relay having an exciting coil that is disconnected from the contact, and a third contact that is connected to the exciting coil and that is energized to the exciting coil by being connected to the first contact by the exciting force of the exciting coil. A vehicle shaft load adjusting and holding device for a wheel shaft, which is characterized by: