JP2549204B2 - Work vehicle operating structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention removably connects a working device to a traveling machine body, and
Based on the control current from the lifting control device, it is configured to be driven up and down by a hydraulic cylinder controlled via an electromagnetic proportional flow control valve, and the hydraulic cylinder can be driven up and down artificially by turning on and off an operating switch. The present invention relates to an operation structure of a work vehicle configured in.

[0002]

2. Description of the Related Art In the operation structure of a work vehicle described above, conventionally, as disclosed in, for example, Japanese Patent Laid-Open No. 1-296906, the operation switch is provided at the rear part of the machine body, and directly through this operation switch. In some cases, the electromagnetic solenoid of the electromagnetic flow control valve is configured to be connected to the battery. The details of the electromagnetic flow control valve are disclosed in, for example, Japanese Patent Application Laid-Open No. 2-209603.

[0003]

SUMMARY OF THE INVENTION The above conventional structure uses an electromagnetic type flow control valve that can be electrically controlled to raise and lower the automatic lifting control of a work device for the purpose of softening a shock when driving is stopped. In addition to controlling the speed, when connecting the working device to the traveling machine body, when the operation switch is turned on and off to descend from the machine body, the connection point of the lift arm on the machine side and the connection point of the work apparatus side are connected to each other. This allows for quick alignment.

However, in the case of the above-mentioned conventional structure, since the battery is directly connected to the electromagnetic solenoid of the electromagnetic hydraulic control valve for switching, when the lifting operation is performed, the pressure from the hydraulic pump is applied to the hydraulic cylinder. Since the entire amount of oil will be supplied immediately, if the engine speed is set to a high speed, the lift arm may move up and down at a high speed, which could cause unexpected harm to the worker, and there was room for improvement. . An object of the present invention is to solve the above-mentioned problems with an inexpensive structure without effectively increasing the cost by effectively utilizing the existing structure.

[0005]

According to the characteristic construction of the present invention, in the operating structure for a working vehicle described at the beginning, the electromagnetic proportional control is performed so that the hydraulic cylinder is moved up and down at a predetermined speed based on the operation of the operation switch. An elevation control means for controlling the flow control valve is provided in the elevation control device.

[0006]

When the work device is connected to the traveling machine body, when the operation switch is operated in order to drive the hydraulic cylinder for aligning the connection points to raise and lower the machine body side connection point, the control device is previously operated. A predetermined control current to be set is supplied to the electromagnetic proportional flow rate control valve to drive the hydraulic cylinder at a constant low speed.

[0007]

Therefore, according to the present invention, the electromagnetic proportional flow rate control valve and the control device which are provided for performing the automatic raising / lowering control associated with the work traveling of the working device in a smooth state without shock are utilized. Then, by simply modifying the structure by changing the control procedure of the control device, the work device can be safely attached to and detached from the machine body.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 3, a rotary cultivating device 2 (an example of a working device) is detachably and vertically movably connected to a rear portion of a riding type traveling body via a three-point link mechanism 1 to form a working vehicle according to the present invention. To do. The three-point link mechanism 1 is composed of a pair of left and right lower links 3, 3 and a top link 4 which are detachably and pivotally connected to the machine body, and a lift arm 6 driven and rocked by a lift cylinder 5. The lower links 3 and 3 are movably connected to the tip end of the tiller via left and right lift rods 7 and 7 so that the tiller 2 can be driven up and down with respect to the machine body. Further, one lift rod 7 is provided by a rolling cylinder 8 so as to be able to extend and contract, and by driving the rolling cylinder 8, the tiller 2 is configured to be able to roll left and right around the longitudinal axis.

As shown in FIG. 2, each of the cylinders 5 and 8 is
Is configured to be driven by pressure oil from a hydraulic pump P driven by an engine E. That is, the pump P
The pressure oil from the rolling cylinder 8 is controlled by the flow priority valve 9 through the electromagnetic 3-position switching valve 10.
The hydraulic circuit is configured to supply the excess flow of the flow priority valve 9 to the lift cylinder 5 via the electromagnetic proportional flow control valve V. The electromagnetic proportional flow control valve V
Includes a first opening / closing valve 11 for rising control and a second opening / closing valve 12 for lowering control, and includes a first opening / closing valve 11, a second opening / closing valve 11,
12 are hydraulic pilot operation type, respectively, and these are electromagnetic operation type first and second provided correspondingly.
The first and second pressure control valves 13 and 14 are operated to open and close.
The on-off valves 11 and 12 are configured to control the flow rate of the pressure oil by changing the opening degree based on the change of the pilot pressure corresponding to the control current value for the first and second pressure control valves 13 and 14.

The electromagnetic solenoids 13a and 14a of the first and second pressure control valves 13 and 14 are, as shown in FIG.
It is configured to be driven by a control current given from the control device 15, and the control device 15 sets the tilling working depth by the tilling device 2 accompanying the work traveling by the tilling depth setting device 17 arranged in the body control unit 16. Elevating control means A for automatically raising and lowering to maintain the value is provided. More specifically, the tiller 2
The rear cover 18 is swingably provided, and a potentiometer-type plowing work depth detector 19 that detects the vertical swing amount as the plowing work depth is provided. The working depth detector 19 and the potentiometer-type plough The output from the depth setter 17 is input to the control device 15 equipped with a microphone computer via the A / D converter 20, and a drive current is supplied to any of the electromagnetic solenoids 13a and 14a so that these values match. The elevation control means A is configured by setting a control program as described above. Also, this control device 15
In the case of controlling the tiller 2 to ascend to the maximum ascending position, for example, the first current that changes the driving current so as to change the driving speed based on the deviation to the target position and reduces the shock accompanying driving. A control means B is provided.

An artificial operation switch SW is provided at the rear part of the control seat 21 of the machine body, and the electromagnetic proportional flow control valve V is operated so that the lift cylinder 5 is moved up and down at a predetermined speed based on the operation of the operation switch SW. The control device 15 is provided with the second current control means C as the ascending / descending speed control means. That is, when the operation switch SW is operated to switch to the raising position u, the electromagnetic solenoid 13a of the first pressure control valve 13 is supplied with a drive current set in advance to drive the lift cylinder 5 to move up slowly. When the switch SW is switched to the lower position, the electromagnetic solenoid 14 of the second pressure control valve 14 is operated.
The second current control means C is configured by setting a control program so as to supply a small drive current to a in advance to drive the lift cylinder 5 to descend slowly.
In this way, the positioning of the connecting points when the cultivating device 2 is attached to or detached from the machine body can be performed safely without the risk of the lift arm 6 unexpectedly driving at high speed.

It should be noted that although reference numerals are given in the claims for facilitating the comparison with the drawings, the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a control block diagram.

[Fig. 2] Hydraulic circuit diagram

[Fig. 3] Side view of the rear part of the work vehicle

[Explanation of symbols]

 2 working device 5 hydraulic cylinder 15 lifting control device C lifting speed control means SW operation switch V electromagnetic proportional flow control valve

Claims (1)

(57) [Claims] 1. A work device (2) is detachably connected to a traveling machine body, and the work device (2) is controlled by an electromagnetic proportional flow control valve based on a control current from a lifting control device (15). The hydraulic cylinder (5) controlled via (V) is configured to be movable up and down, and the hydraulic cylinder (5) is configured to be artificially movable up and down by turning on and off the operation switch (SW). An operating structure of a working vehicle, wherein an ascending / descending speed that controls the electromagnetic proportional flow control valve (V) so that the hydraulic cylinder (5) is ascended / descended at a predetermined speed based on an operation of the operation switch (SW). The control means (C) is provided with the lifting control device (15).
The operating structure of the work vehicle prepared for the.