JP3613430B2 - Auxiliary travel device for towed vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an auxiliary traveling device for a towed vehicle, and more particularly to an auxiliary traveling device for a towed vehicle suitable for use in an agricultural work vehicle or the like that is pulled by a tractor or the like on a soft ground such as a wet field.
[0002]
[Prior art]
In recent years, for example, agricultural work vehicles have been increasing in size and their weight has increased. For this reason, especially in wet fields, the tire of a towed work vehicle towed by a tractor or the like often touches the soft ground, making it difficult to carry out farming work by the tractor or the like. Measures for preventing the tire of the towed work vehicle from entering the soft ground include increasing the tire width or the tire diameter of the towed work vehicle or increasing the number of tires.
[0003]
[Problems to be solved by the invention]
However, measures such as the increase in the tire width or tire diameter of the conventional towed work vehicle described above and the increase in the number of tires have a certain effect with respect to the above-described tire insertion, but the tire starts to slip once. When it stops rotating, there is a problem that it becomes difficult to tow further.
[0004]
The present invention has been made to solve such a problem, and can effectively prevent the tire of the towed vehicle from being pushed even on a soft ground such as a wet field, so that the towing operation can be performed easily and easily. It is an object of the present invention to provide an auxiliary traveling device for a towed vehicle that can be made efficient.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problem, an auxiliary traveling device for a towed vehicle according to the present invention is provided with a hydraulic motor for driving the tire in a towed vehicle traveling with a tire. This hydraulic motor is, for example, operated by a variable displacement hydraulic pump or is of a variable displacement type, and drives the tire with a constant driving force from when the towed vehicle is stopped to a predetermined set speed. Further, a clutch is provided between the hydraulic motor and the tire, and this clutch can cut off the driving of the tire by the hydraulic motor when the vehicle speed of the towed vehicle exceeds the predetermined set speed.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. In FIG. 1, reference numeral 1 indicates an agricultural work vehicle in which the auxiliary traveling device for a towed vehicle according to the present invention is implemented, and the vehicle is towed by a tractor 60.
[0007]
As shown in FIGS. 2 and 3, sprockets 7 are respectively fixed to the axles 6 of the tires 5 on both sides of the agricultural work vehicle 1. Two hydraulic motors 10 and 15 and two overrunning clutches 20 and 20 are arranged on the frame 8 of the agricultural work vehicle 1, respectively, and the output shafts 13 and 18 of the hydraulic motors 10 and 15 and the overrunning clutches are arranged. (Clutch) 20 and 20 are connected to input shafts (not shown). Sprockets 21 are respectively fixed to output shafts (not shown) of the overrunning clutch 20, and chains 22 are wound between the sprocket 21 of the overrunning clutch 20 and the sprocket 7 of the axle 6 described above.
[0008]
In addition, as shown in FIG. 3, the agricultural work vehicle 1 includes a variable displacement hydraulic pump 30 with pressure compensation, a directional control valve 40 that is a no-spring type 4-port 2-position manual switching valve, and a tank 50. Arrange. The inlet 31 of the hydraulic pump 30 is connected to the tank 50, and the outlet 32 of the hydraulic pump 30 is connected to the inlet 41 of the direction control valve 40. Further, the outlet 42 of the direction control valve 40 is connected to the inlet 11 of one hydraulic motor 10, and the outlet 12 of the hydraulic motor 10 is connected to the inlet 16 of the other hydraulic motor 15. The outlet 17 of the hydraulic motor 15 is connected to the inlet 43 of the direction control valve 40, and the outlet 44 of the direction control valve 40 is connected to the tank 50. The hydraulic pump 30 receives a necessary rotational force from the tractor 60 to be pulled.
[0009]
The hydraulic pump 30 described above is a variable displacement hydraulic pump with pressure compensation capable of continuously changing the discharge amount Q by adjusting the discharge amount adjusting screw 33. The output characteristics of the hydraulic pump 30 are represented by FIG. 4, and FIG. 4 shows the relationship between the discharge pressure P and the discharge amount Q of the hydraulic pump 30. In the hydraulic pump 30, the discharge amount Q is constant (QO) until the discharge pressure P reaches the cutoff pressure (PO), but when the discharge pressure P rises to PO, the discharge amount Q decreases from QO to zero. It decreases rapidly and continuously. The variable displacement hydraulic pump without pressure compensation has the characteristics shown by the broken line in FIG. 4 and reduces the discharge amount Q while slightly increasing the pressure from the cutoff pressure (PO 2) to the dead head pressure (PD 2). Since the hydraulic pump 30 has pressure compensation, the discharge amount Q is changed from QO to zero under a constant discharge pressure PO 2.
[0010]
In the auxiliary travel device, the rotational speed of the hydraulic motors 10 and 15 is changed by using the change in the discharge amount Q in the region R of the discharge pressure PO 2 among the output characteristics of the hydraulic pump 30 shown in FIG. Is. In other words, the hydraulic pump 30 always rotates the hydraulic motors 10 and 15 at a constant discharge pressure PO 2 regardless of the discharge amount Q. For this reason, the hydraulic motors 10 and 15 change their rotational speed according to the supply amount Q of oil supplied from the hydraulic pump 30, but since the operating pressure PO is constant, the generated torque is always constant regardless of the rotational speed. It is constant. In this way, the tire 5 driven by the hydraulic motors 10 and 15 is always driven to rotate at a constant driving force PO 1 regardless of the number of rotations.
[0011]
Next, a method for using the auxiliary traveling device for a towed vehicle according to the present invention will be described with reference to FIGS. 3 and 4.
First, it is confirmed that the operation lever 45 of the direction control valve 40 is in the off (off) position, and after the confirmation, the hydraulic pump 30 is rotated. At this time, since the inlet 41 of the direction control valve 40 communicates with the outlet 44, the oil discharged from the hydraulic pump 30 returns to the tank 50. Next, the discharge amount adjusting screw 33 of the hydraulic pump 30 is adjusted to set the auxiliary travel speed (vehicle speed) of the towed vehicle to a predetermined set speed required for the work. Specifically, for example, a discharge amount Q1 corresponding to a predetermined set speed S1 is determined within the region R of the relationship diagram shown in FIG. 4, and the discharge amount of the hydraulic pump 30 is discharged so that this discharge amount Q1 is discharged. The adjustment screw 33 is adjusted. Next, the operation lever 45 of the direction control valve 40 is set to the on (on) position. As a result, the inlet 41 of the direction control valve 40 communicates with the outlet 42, and oil is supplied from the hydraulic pump 30 to the hydraulic motors 10 and 15, and the hydraulic motors 10 and 15 respectively rotate at a rotational speed corresponding to the discharge amount Q1. Rotate. The rotational force of the hydraulic motors 10 and 15 is transmitted to the tire 5 through the overrunning clutch 20, the sprocket 21, the chain 22, the sprocket 7 and the axle 6 in this order, and the tires 5 on both sides are driven to rotate. To do.
[0012]
In this auxiliary travel device, unless the discharge amount adjusting screw 33 of the hydraulic pump 30 is readjusted to change the discharge amount Q1 described above, the hydraulic motors 10 and 15 always maintain the tire 5 at a constant level based on the discharge pressure PO described above. Is rotated at a rotational speed corresponding to the predetermined set speed S1. Next, when the vehicle travels at a predetermined set speed S2 that is faster than the above-described predetermined set speed S1, for example, within the range of the region R in the relationship diagram shown in FIG. And a discharge amount adjusting screw 33 of the hydraulic pump 30 is adjusted so that oil of this discharge amount Q2 is discharged. The hydraulic motors 10 and 15 rotate at a rotational speed corresponding to the increased discharge amount Q2, and rotate the tire 5 at a rotational speed corresponding to the predetermined set speed S2. At this time, the driving force for driving the tire 5 is the constant driving force PO 1 generated by the above-described discharge pressure PO 2.
[0013]
Here, for example, when the predetermined set speed is S2, and the agricultural work vehicle 1 is pulled at a vehicle speed S3 exceeding the predetermined set speed S2, the hydraulic motors 10 and 15 are operated by the action of the overrunning clutch 20. And the sprocket 21 is disconnected, the tire 5 can freely rotate, and the agricultural work vehicle 1 is pulled at the vehicle speed S3. Further, when the vehicle speed of the agricultural work vehicle 1 decreases again from S3 to the predetermined set speed S2 or less, the overrunning clutch 20 causes the hydraulic motors 10 and 15 and the sprocket 21 to be connected again, so that the tire 5 It is rotationally driven at the rotational speed corresponding to the predetermined set speed S2 with the constant driving force described above.
[0014]
Next, when the operation lever 45 of the direction control valve 40 is set to the OFF position, the supply of oil from the hydraulic pump 30 to the hydraulic motors 10 and 15 is stopped as described above, so that the rotation of the hydraulic motors 10 and 15 is stopped. To do. Also at this time, the connection between the hydraulic motors 10 and 15 and the sprocket 21 is disconnected by the action of the overrunning clutch 20, so that the tire 5 can freely rotate, and the tractor 60 pulls the agricultural work vehicle 1. Is possible. On the other hand, when the discharge amount adjusting screw 33 of the hydraulic pump 30 is adjusted so that the above-described predetermined set speed is 0 km / hr, the hydraulic pump 30 rotates, but no oil is discharged from the hydraulic pump 30. Even when the operation lever 45 of the control valve 40 is in the ON position, the hydraulic motors 10 and 15 do not rotate. Also in this case, due to the action of the overrunning clutch 20, the connection between the hydraulic motors 10, 15 and the sprocket 21 is cut and the tire 5 can freely rotate, and the tractor 60 pulls the agricultural work vehicle 1. Is possible.
[0015]
In the auxiliary traveling device for the towed vehicle described above, the rotational speed of the tire 5 is changed under a constant driving force PO 2 using the variable displacement hydraulic pump 30 and the hydraulic motors 10 and 15. However, the present invention is not limited to this. For example, the rotational speed of the tire can be changed under a constant driving force using a variable displacement hydraulic motor. Moreover, although the hydraulic pump 30, the direction control valve 40, and the tank 50 were arrange | positioned in the agricultural work vehicle 1, it is not limited to this, It is arrange | positioned in the tractor 60 which pulls all or one part of these. You can also.
[0016]
【The invention's effect】
As described above in detail, the auxiliary traveling device for a towed vehicle according to the present invention is provided with a hydraulic motor for driving the tire in a towed vehicle traveling with a tire. In other words, the towed vehicle itself drives the tires, so that the towed vehicle tires are effectively prevented even on a soft ground such as a wet field, and the towing operation is extremely easy and efficient. There is an excellent effect of becoming a target.
[0017]
This hydraulic motor is operated by, for example, a variable displacement hydraulic pump or is of a variable displacement type, and drives the tire with a constant driving force set in advance from when the towed vehicle is stopped to a predetermined set speed. As a result, the tire of the towed vehicle is driven with this constant driving force at any vehicle speed from when the towed vehicle stops to a predetermined set speed, so that the tire can rotate even on a soft ground such as a wet field. Thus, it is possible to reliably avoid the situation where the vehicle cannot be pulled.
[0018]
Further, a clutch is provided between the hydraulic motor and the tire, and this clutch can cut off the driving of the tire by the hydraulic motor when the vehicle speed of the towed vehicle exceeds the predetermined set speed. As a result, the towed vehicle being driven by the hydraulic motor is towed at a speed exceeding the predetermined set speed at that time, and the towed vehicle is turned off by turning off the drive by the hydraulic motor or setting the predetermined set speed to 0 km / hr. Each of them can be towed, and the tow work on the ground which does not particularly require auxiliary traveling by a hydraulic motor is made efficient.
[Brief description of the drawings]
FIG. 1 is a front view showing a towed vehicle in which an auxiliary traveling device for a towed vehicle according to the present invention is implemented.
FIG. 2 is a side view showing an auxiliary traveling device of the towed vehicle 1 of FIG.
FIG. 3 is a circuit diagram showing a hydraulic circuit of an auxiliary travel device of the towed vehicle 1 of FIG. 1;
4 is a relationship diagram illustrating a relationship between a discharge pressure P and a discharge amount Q of the hydraulic pump 30 in FIG. 3;
[Explanation of symbols]
1 Agricultural work vehicle, 5 tires, 6 axles, 7 sprocket, 8 frame, 10 hydraulic motor, 11 inlet, 12 outlet, 13 output shaft, 15 hydraulic motor, 16 inlet, 17 outlet, 18 output shaft, 20 overrunning clutch , 21 sprocket, 22 chain, 30 hydraulic pump, 31 inlet, 32 outlet, 33 discharge adjustment screw, 40 direction control valve, 41 inlet, 42 outlet, 43 inlet, 44 outlet, 45 operation lever, 50 tank, 60 tractor

Claims (1)

A towed vehicle (1) that travels with a tire (5) includes a hydraulic motor (10 , 15) that drives the tire, and a clutch between the hydraulic motor (10, 15) and the tire (5) ( 20), and the hydraulic motor (10, 15) is actuated by a variable displacement hydraulic pump (30) or is of a variable displacement type, and from the time when the towed vehicle (1) is stopped to a predetermined set speed. And driving the tire by the hydraulic motor when the vehicle speed of the towed vehicle (1) exceeds the predetermined set speed. An auxiliary traveling device for a towed vehicle.

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