JPH04222507A - Operation structure of work vehicle - Google Patents

Abstract

PURPOSE:To provide an operation structure capable of safely carrying out installing and removing operation of a working device for a mobile machine body by simply improving the structure. CONSTITUTION:A lifting or lowering controller 15 is equipped with a lifting or lowering controlling means (A) capable of controlling a solenoid proportional flow control valve so as to lift, lower and drive a working device at a prescribed speed based on the turning ON and OFF operation of an operation switch (SW).

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention connects a working device to a traveling machine body in a detachable manner, and also connects the working device to a traveling machine body.
Based on the control current from the elevation control device, the hydraulic cylinder is controlled via an electromagnetic proportional flow control valve so that it can be driven up and down, and the hydraulic cylinder can be driven up and down artificially by turning on and off an operation switch. The present invention relates to an operating structure for a work vehicle configured in the following.

0002

2. Description of the Related Art Conventionally, in the operation structure of the above-mentioned work vehicle, as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 1-296906, the operation switch is provided at the rear of the machine body, and the operation switch is directly operated via the operation switch. There was one in which the electromagnetic solenoid of the electromagnetic flow control valve was connected to the battery. The details of the electromagnetic flow control valve are disclosed in, for example, Japanese Patent Laid-Open No. 2-209603.

0003

[Problems to be Solved by the Invention] The above conventional structure uses an electromagnetic flow control valve that is easy to control electrically for the purpose of alleviating the shock when the drive is stopped in the automatic lifting and lowering control of working equipment. In addition to controlling the speed, when connecting a working device to the traveling machine, the connection point of the lift arm on the machine side and the connecting point on the working device side are This is to enable quick positioning.

However, in the conventional structure described above, since the battery is directly connected to the electromagnetic solenoid of the electromagnetic hydraulic control valve to switch the control valve, when the lift is operated, the pressure from the hydraulic pump is applied to the hydraulic cylinder. Since the entire amount of oil is supplied immediately, if the engine speed is set to a high speed, the lift arm may move up and down at high speed, potentially causing unexpected harm to the worker, so there was room for improvement. . It is an object of the present invention to effectively utilize the existing structure to eliminate the above-mentioned problems with an inexpensive configuration without increasing costs.

[0005]

[Means for Solving the Problems] A characteristic configuration of the present invention is that in the operation structure for a working vehicle described at the beginning, the electromagnetic proportional The above-mentioned elevation control device is provided with an elevation speed control means for controlling the flow rate control valve.

[0006]

[Operation] When connecting the working device to the traveling aircraft, the control device is activated in advance by operating the operation switch to drive the hydraulic cylinder to raise and lower the connecting point on the aircraft side in order to align the connecting point. A predetermined control current is supplied to the electromagnetic proportional flow control valve to drive the hydraulic cylinder at a constant low speed.

[0007]

Therefore, according to the present invention, the electromagnetic proportional flow control valve and control device provided for performing automatic lifting control as the working equipment travels in a smooth state without shock are utilized. By simply changing the control procedure of the control device, it is now possible to safely attach and detach the work device to the aircraft.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. As shown in FIG. 3, the working vehicle according to the present invention is constructed by connecting a rotary tilling device 2 (an example of a working device) to the rear of a riding type traveling machine body via a three-point linkage mechanism 1 so as to be detachable and movable up and down. do. The three-point link mechanism 1 includes a pair of left and right lower links 3, 3 and a top link 4 which are pivotally connected to the body in a detachable manner, and includes a lift arm 6 which is driven and swung by a lift cylinder 5. The lower links 3, 3 are connected to the distal end of the tiller 2 via left and right lift rods 7, 7 so as to be able to be lifted, so that the tilling device 2 can be moved up and down with respect to the machine body. Further, one of the lift rods 7 is provided to be extendable and retractable by a rolling cylinder 8, and by driving the rolling cylinder 8, the tilling device 2 is configured to be able to freely roll left and right around the front and back axis.

As shown in FIG. 2, each of the cylinders 5 and 8
is configured to be driven by pressure oil from a hydraulic pump P driven by an engine E. In other words, 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 surplus 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
is equipped with a first on-off valve 11 for ascending control and a second on-off valve 12 for descending control, and also includes a first on-off valve 11, a second on-off valve 11,
12 are each configured as a hydraulic pilot operated type, and are opened and closed by electromagnetically operated first and second pressure control valves 13 and 14 provided correspondingly, respectively, and the first and second on-off valves 11, Reference numeral 12 is configured to control the flow rate of pressurized oil by changing the opening degree based on a change in pilot pressure corresponding to the control current value for the first and second pressure control valves 13 and 14.

As shown in FIG. 1, the electromagnetic solenoids 13a and 14a of the first and second pressure control valves 13 and 14 are
The control device 15 is configured to be driven by a control current given from a control device 15, and the control device 15 is configured to set the tilling work depth by the tilling device 2 during work traveling by a tilling depth setting device 17 disposed in the machine control section 16. Elevation control means A is provided for automatically elevating and lowering the device to maintain the same value. To explain in detail, tilling device 2
The rear cover 18 is provided to be swingable, and a potentiometer-type tilling depth detector 19 is provided to detect the amount of vertical swing of the rear cover 18 as the tilling depth. The output from the depth setting device 17 is input to the control device 15 equipped with a microcomputer via the A/D converter 20, and a drive current is supplied to either 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 shown in FIG. Moreover, this control device 15
For example, when controlling the tilling device 2 to raise it to the maximum raising position, the first current changes the driving current so as to change the driving speed based on the deviation to the target position, thereby reducing the shock associated with driving. Control means B are provided.

[0011] A human operation switch SW is provided at the rear of the control seat 21 of the aircraft, and based on the operation of this operation switch SW, the electromagnetic proportional flow control valve V is operated so that the lift cylinder 5 is driven up and down at a predetermined speed. The control device 15 is equipped with a second current control means C as a control means for controlling the ascending and descending speed. That is, when the operation switch SW is switched to the upward position u, a preset drive current is supplied to the electromagnetic solenoid 13a of the first pressure control valve 13 to slowly drive the lift cylinder 5 upward, and the operation is performed. When the switch SW is switched to the downward position, the electromagnetic solenoid 14 of the second pressure control valve 14 is activated.
The second current control means C is configured by setting a control program to slowly drive the lift cylinder 5 downward by supplying a drive current set in advance to be a small amount. In this way, the positioning of the connection points when attaching and detaching the tilling device 2 to and from the machine body can be safely performed without fear of the lift arm 6 being unexpectedly driven at high speed.

Although reference numerals are written in the claims to facilitate comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

[Figure 1] Control block diagram

[Figure 2] Hydraulic circuit diagram

[Figure 3] Side view of the rear of the work vehicle

[Explanation of symbols]

2 Work equipment 5 Hydraulic cylinder 15 Lifting control device C Lifting speed control means SW Operation switch V Solenoid proportional flow control valve

Claims (1)

[Claims] Claim 1: A working device (2) is removably connected to the traveling machine body, and the working device (2) is connected to an electromagnetic proportional flow control valve based on a control current from an elevation control device (15). Hydraulic cylinder (5) controlled via (V)
), and the hydraulic cylinder (5) is configured to be driven up and down artificially by turning on and off an operation switch (SW), wherein Based on the operation of the lift control device (SW), the lift control device (SW) controls the lift speed control means (C) that controls the electromagnetic proportional flow control valve (V) so that the hydraulic cylinder (5) moves up and down at a predetermined speed. ) The operating structure of the work vehicle.