JPH05295706A - Driving device for road roller - Google Patents

Abstract

PURPOSE:To prevent the idle revolution of a roll pressing wheel having the less wheel load by reducing the turning moment of a roll pressing wheel having the less wheel load in comparison with the turning moment of a roll pressing wheel having the larger wheel load. CONSTITUTION:A hydraulic pump 3 is operated in the advance direction of a road roller, and the pressurized oil in the direction of the full line arrow is supplied into hydraulic circuits 13 and 14 in parallel. In the circuit 13, the pressurized oil is flow-rate- regulated by a throttle valve 16, and supplied into a hydraulic motor 11 to drive front wheels 6 in the normal revolution. Then, in the circuit 14, the pressurized oil is supplied into a hydraulic motor 12 to rolling-drive rear wheels 7 in the normal direction. The supply quantity of the pressurized oil to the motor 11 is reduced to suppress the turning moment of the front wheel 6, and the idle revolution of the front wheel 6 in the start and advance is prevented. Further, in case of the retreat start, the pressurized oil flows in the broken-line arrow, and in the circuit 13, the oil returns into the pump 3 without being throttled, since the oil passes through a check valve 18, and the turning moment of the front wheel 6 is not suppressed. Accordingly, the idle revolution of roll pressing wheels on the side having the less wheel load can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front and rear two-wheel drive system in which hydraulic pressure motors are individually provided on both front and rear rolling wheels made of iron wheels, and oil is supplied to both hydraulic motors in parallel from the same hydraulic pump. More particularly, the present invention relates to a drive device that prevents the compaction wheel on the side with a lighter wheel load from idling when starting either forward or reverse, when switching between forward and reverse, and when climbing.

[0002]

2. Description of the Related Art Both front and rear compaction wheels are iron wheels,
The load roller, in which the hydraulic motors of both rolling wheels are connected in parallel to the same hydraulic power source, has been well received because the driving force acts on the front and rear rolling wheels and the rolling surface is clean. ..

[0003]

However, in the case where a load roller having a relatively small axial distance between the front and rear wheels with respect to the vehicle height performs a compaction work, the front side in the traveling direction at the time of startup or switching between forward and reverse travel. There is a case where idling occurs in the compaction wheel, dragging occurs on the compaction surface, and the finished surface is damaged. This is because the load temporarily moves rearward in the traveling direction due to inertia at startup, etc., and the grounding load of the rolling wheel on the front side in the traveling direction becomes lighter, and the rolling wheel receives a frictional force against the grounding surface. This is because the driving force of the compaction wheel becomes larger. This phenomenon is likely to occur especially when the compaction wheel having a lighter wheel load is located on the front side in the traveling direction.

Similarly, in order to place the load rollers, which have relatively small front and rear wheel distances with respect to the vehicle height, on the truck carrier for transportation, the load rollers are mounted on a walk board installed between the ground and the carrier. When climbing over a certain angle, such as when climbing by running, the load on the roller on the front side in the traveling direction, which is the upper side, becomes smaller, and the friction force of the roller on the front side in the traveling direction becomes smaller. The driving force of the rolling wheel becomes larger, and this idles and the working oil concentrates and flows to the hydraulic motor on the front side in the traveling direction, while the working oil does not flow to the hydraulic motor on the rear side and it becomes impossible to climb the hill. Sometimes. This phenomenon also tends to occur particularly when the compaction wheel with the lighter wheel load is located on the front side in the traveling direction.

An object of the present invention is to solve such a conventional problem and prevent the compaction wheel having a lighter wheel load from idling.

[0006]

Therefore, according to the present invention,
Both are equipped with hydraulic motors individually on both front and rear rolling wheels made of iron wheels, and both hydraulic motors are connected in parallel to the same hydraulic pump to presume a device that drives front and rear wheel drive load rollers. A throttle valve for suppressing the amount of pressure oil supplied to the hydraulic motor is provided in the hydraulic circuit for driving the compaction wheel on the side where the wheel load is light.

Further, at least one of between the hydraulic motor for the compaction wheel on the front side of the vehicle body and the compaction wheel and between the hydraulic motor for the compaction wheel on the rear side of the vehicle body and the compaction wheel thereof. It is also possible to interpose a speed reducer having a speed reduction ratio in which the reduction ratio between the hydraulic motor and the compaction wheels on the side where the wheel load is light is smaller than the reduction ratio between the hydraulic motor and the compaction wheels on the side where the wheel load is heavy. Further, even if a hydraulic motor having an intake amount smaller than the intake amount of the hydraulic motor for driving the compaction wheel on the wheel load side is applied as a hydraulic motor for driving the compaction wheel on the light wheel load side. Good.

[0008]

According to the above device, the throttle valve suppresses the amount of oil to the motor on the light wheel load side, or the reduction ratio of the compacting wheel on the light wheel load side reduces the rolling pressure on the heavy wheel load side. Either device is smaller than the wheel, or the rotational force transmitted to the compaction wheel on the light wheel load side is lower than that on the heavier wheel load side. The rotational force of the compaction wheel is suppressed more than that of the heavier wheel load. Therefore, whether the vehicle starts on a flat road surface or performs a climbing work, an appropriate rotational force acts on each compaction wheel to prevent the compaction wheel having a lighter wheel load from idling. Therefore, the front and rear wheels can normally roll the road surface, and a climbing road such as a walk board for loading on a truck can be stably climbed. It should be noted that when the vehicle descends on a downward slope, it is urged in the downward direction by the weight of the entire load roller, so that idling due to the light weight of the wheel load does not occur.

[0009]

Embodiments FIGS. 1 and 2 show a first embodiment in which a hand guide type roller is applied as a load roller. The load roller 1 includes an engine 2, a hydraulic pump 3 rotated by the engine 2, a predetermined device such as a charge pump 4 interlocked with the engine 2, and the like mounted on a vehicle body 5, and the lower side of the vehicle body 5 is made of iron wheels. A front wheel 6 and a rear wheel 7 as a compaction wheel in which an oscillating device is arranged are suspended, and a hand guide lever 8 is mounted at the rear end of the vehicle body 5 and a handle 9 is provided at the rear end.

The front wheel 6 and the rear wheel 7 have the same diameter, and the output shafts of the hydraulic motors 11 and 12 are individually and directly connected to their shafts, respectively, as is well known, to rotate the hydraulic motors 11 and 12. Both wheels 6 and 7 are driven by.
The hydraulic motors 11 and 12 are known ones having mutually the same suction capacity and incorporating a speed reducer having the same speed reduction ratio. Therefore, if the same amount of pressure oil is supplied, the same rotational speed and rotational force are output to the front and rear wheels 6, 7. These hydraulic circuits 13 and 14
Are connected in parallel to the hydraulic pump 3.

The control necessary for the operation of the load roller 1, such as the control of the discharge direction and the discharge amount of the pressure oil of the hydraulic pump 3 and the control of the actuation or non-actuation of the vibrators in the front wheels 6 and the rear wheels 7, are as follows:
As is known, the lever 15 provided near the handle 9 of the hand guide lever 8 is operated, and the steering of the load roller 1 is performed by steering the vehicle body 5 by swinging the hand guide lever 8 left and right. Here, when the steering angle is large, the steering wheel 9 is often pushed down and the front wheels 6 are floated from the road surface with the rear wheels 7 as the fulcrum. It is smaller than the load.

In this embodiment, the hydraulic circuit 13 for the front wheels 6 is
The throttle valve 16 is provided in the. That is, in the hydraulic circuit 13,
A throttle valve 16 is provided on the inlet side of the pressure oil to the hydraulic motor 11 when the front wheels 6 rotate normally, that is, when the load roller 1 rotates in the forward direction, and a check valve 18 is provided in parallel with the throttle valve 16. .. The check valve 18 moves from the hydraulic pump 3 to the hydraulic motor 1
It is arranged in a direction to stop the pressure oil toward 1.

When the hydraulic pump 3 driven by the engine 2 is operated in the direction of advancing the load roller 1, pressure oil flows in the direction indicated by the solid arrow in FIG. That is, the pressure oil is discharged from the upper port of the hydraulic pump 3 in FIG. 2 and supplied to the hydraulic circuits 13 and 14 in parallel. At this time, in the hydraulic circuit 13, the pressure oil is supplied to the hydraulic motor 11 whose flow rate is regulated by the throttle valve 16 and the rotational force of the hydraulic motor 11 drives the front wheels 6 to rotate in the forward direction. The oil flowing out of 11 returns to the hydraulic pump 3 from the lower side port of the hydraulic pump 3 in FIG.

On the other hand, in the hydraulic circuit 14, the pressure oil is directly supplied to the hydraulic motor 12, the rotational force of the hydraulic motor 12 drives the rear wheels 7 in the normal direction, and the oil flowing out from the hydraulic motor 12 is the oil. After joining the return oil from 13, it returns to the hydraulic pump 3 in the same manner as described above. Hydraulic pump 3
In contrast to the above, when the load roller 1 is operated in the backward direction, the pressure oil flows in the direction opposite to the normal rotation of the hydraulic pump 3 as indicated by the broken line arrow in FIG. At this time, the pressure oil inlets and outlets of the hydraulic motors 11 and 12 are reversed, and the pressure oil supplied to the hydraulic motor 11 cannot be throttled, and the pressure oil supplied to the hydraulic motor 12 also has a throttle valve in the hydraulic circuit 14. It can't be narrowed down because it doesn't exist. Hydraulic motor 1
The oil flowing out of 1 passes through the check valve 18 to return to the hydraulic pump 3 due to the resistance of the throttle valve 16.

The oil in the circuit is replenished to the low pressure side by the charge pump 4. Further, in this embodiment, the throttle valve 16 acts on the inlet side of the hydraulic motor 11, so that the back pressure by the throttle valve 16 does not act on the hydraulic motor 11. Thus, the throttle valve 16 throttles the pressure oil supplied to the front wheels 6 to suppress the pressure oil supply amount to the hydraulic motor 11 when the road roller 1 moves forward, so that the rotational force of the front wheels 6 is suppressed. ..

Therefore, when the load roller is started in the forward direction, the load temporarily moves backward due to inertia, whether it is started from the stopped state or switched from the reverse direction to the forward direction. Even if the wheel load on the front wheel 6 is further reduced, the rotational force of the front wheel 6 is reduced as described above, so that the front wheel 6 with a small load is prevented from idling. For this reason, it is possible to form clean rolling surfaces of both drive wheels. When the load roller 1 starts in the reverse direction, the rear wheel 7 having a large wheel load is located on the front side in the direction of travel, and thus the frictional force due to the load of the rear wheel 7 is large and the rotational force of the rear wheel 7 is suppressed. Therefore, the occurrence of idling is prevented.

In addition, when the road roller 1 is to climb a steep slope, such as when climbing by itself on the upper surface of an inclined step board for stacking on a transport truck, the traveling direction is limited by the visibility. The front side of the car is often the front wheel. In such a case, due to the forward inclination of the vehicle body 5, the wheel load of the rear wheel 7 on one side is further increased than that during traveling on a flat ground, and the wheel load on the front side is further reduced on the other side, so that the front wheel 6 The frictional force between the road surface and the road surface will decrease. Then, the front wheels 6 run idle due to over-rotational force, the working oil concentrates on the hydraulic motor of the front wheels, and the working oil does not flow to the hydraulic motor of the rear wheels.
Although it may not be possible to climb the slope, this is prevented because the rotational force of the front wheels 6 is suppressed.

The throttle valve 16 may be a variable throttle valve, but in this case, it may be a manual variable throttle valve or an electromagnetic variable throttle valve. In the case of manual operation, the operator can manually operate according to the inclination angle of the uphill road, the frictional force between the rolling surface and the rolling wheels, and the like. In this case, a lever or handle for manual operation may be provided with a scale indicating the degree of squeezing.

In the case of the electromagnetic type, particularly by means for detecting the wheel load of the front wheels 6, when it is detected that the wheel load falls below a predetermined value, the actuating device is operated via the control device, It is suitable to configure the variable throttle valve 16 to be throttled. If the opening of the variable throttle valve 16 at this time can be set in multiple stages, the detection by the detection means may be detected in multiple stages according to the degree of change in wheel load. It is also possible to omit the check valve 18 and allow the pressure oil in any direction to pass through the throttle valve 16.

FIG. 3 is a partial view showing the second embodiment.
That is, instead of the throttle valve 16 and the check valve 18 of the first embodiment, the hydraulic motors 11 and 12 having mutually the same suction capacity.
The speed reduction ratio of the speed reducer built in is changed between front and rear. The speed reducers 21 and 22 shown here schematically represent the ones built in the hydraulic motors 11 and 12. Actually, as is well known, the hydraulic motor and the speed reducer are arranged in the same casing. It is a thing. Most of the built-in speed reducers 21 and 22 use a planetary gear mechanism, but since FIG. 3 is a schematic diagram, spur gear speed reducers 21 and 22 are used. Of course, the reduction ratio of the speed reducer 21 on the front wheel 6 side is reduced to reduce the rotational force of the front wheel 6.
Since the hydraulic circuits 13 and 14 are arranged in parallel, pressure oil is supplied to the circuit with the lower hydraulic pressure. Therefore, as long as the front wheel 6 side and the rear wheel 7 grip the road surface, the peripheral speed of both wheels is increased. Are the same.

In this embodiment, the hydraulic motors 11, 1
I used the one with built-in speed reducers 21, 22 as 2,
When the hydraulic motors 11 and 12 do not have a built-in reducer, it goes without saying that another reducer is interposed between the output shaft and both wheels 6 and 7. In this case, the speed reducer may be separately provided on the front wheel 6 side and the rear wheel 7 side, or the speed change ratio between the hydraulic motor 11 and the front wheel 6 may be increased from the speed ratio between the hydraulic motor 12 and the rear wheel 7. Only one of the speed reducers may be used as long as it is increased.

The second embodiment is the same as the first embodiment except for the speed reducers 21 and 22, so that the description of the first embodiment can be applied to the other description as it is. .. FIG. 4 is a diagram showing a third embodiment. That is, in place of the throttle valve 16 and the check valve 18 of the first embodiment, in the third embodiment, the suction capacity of the hydraulic motor 11 for the front wheels 6 is made smaller than that of the hydraulic motor 12 for the rear wheels 7. By doing so, the maximum rotational force of the front wheels 6 is made smaller than that of the rear wheels 7.

In each of the embodiments described above, means for suppressing the maximum rotational force of the front wheels more than that for the rear wheels is individually adopted, but at least two of these suppressing means can be used together. Of course. Further, in each of the above-described embodiments, the wheel load of the rear wheel 7 is larger than that of the front wheel 6, but when the wheel load of the front wheel 6 is larger than that of the rear wheel 7, conversely, the wheel load of the rear wheel 7 is opposite. The present invention can be applied by using a means that suppresses the maximum rotational force as compared with that of the front wheels. Further, instead of the road roller 1 of the hand guide type, an operator rides on the vehicle body and steers the vehicle. Of course, the present invention can be applied to a road roller.

[0024]

As described above, according to the present invention, since the rotational force of the compaction wheel on the side having a small wheel load is suppressed more than that on the side having a large wheel load, the front and rear compaction wheels have a smaller force. Even when the road rollers with different wheel loads are traveling on a flat road surface or while climbing a slope, a rotating force corresponding to the frictional force with the road surface can be obtained. The rolling wheel is prevented from idling. For this reason, both the front and rear wheels can normally roll the road surface at the time of starting to one of the forward and backward movements, switching from one of the forward and backward movements to the other, and also when climbing a slope. There is an effect that you can climb up surely.

[Brief description of drawings]

FIG. 1 is an overall side view of a first embodiment.

FIG. 2 is a hydraulic circuit diagram of the first embodiment.

FIG. 3 is a partial explanatory view of the second embodiment.

FIG. 4 is a partial explanatory view of the third embodiment.

[Explanation of symbols]

 1 ... Road roller 2 ... Engine 3 ... Hydraulic pump 5 ... Vehicle body 6 ... Front wheel 7 ... Rear wheel 11,12 ... Hydraulic motor 13,14 ... Hydraulic circuit 16 ... Throttle valve 18 ... Check valves 21,22 ... Reducer

Claims (3)

[Claims] 1. A device for driving front and rear wheel drive load rollers, wherein hydraulic pressure motors are individually provided on both front and rear rolling wheels each of which is an iron wheel, and both hydraulic motors are connected in parallel to the same hydraulic pump. A drive device for a load roller, wherein a hydraulic circuit for driving the compaction wheel having a lighter wheel load is provided with a throttle valve for suppressing the amount of pressure oil supplied to the hydraulic motor. 2. A device for driving a front and rear wheel drive load roller, wherein hydraulic pressure motors are individually provided on both front and rear rolling wheels made of iron wheels, and both hydraulic motors are connected in parallel to the same hydraulic pump. , Between the hydraulic motor for the compaction wheel on the front side of the vehicle body and the compaction wheel thereof, and between the hydraulic motor for the compaction wheel on the rear side of the vehicle body and the compaction wheel thereof,
A load roller characterized by interposing a speed reducer having a reduction ratio of a hydraulic motor and a compaction wheel on a light wheel load side smaller than a reduction ratio of a hydraulic motor and a compaction wheel on a heavy wheel load side. Drive. 3. A device for driving a load roller for driving both front and rear wheels, wherein hydraulic pressure motors are individually provided on both front and rear rolling wheels each of which is an iron wheel, and both hydraulic motors are connected in parallel to the same hydraulic pump. A hydraulic motor having a suction amount smaller than the suction amount of the hydraulic motor for driving the compaction wheel on the wheel load side is used as a hydraulic motor for driving the compaction wheel on the light wheel load side. Drive device for road roller.