JPH0481404B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides pressure oil from a pump to be supplied to a cylinder for lifting and lowering ground work equipment through a manual switching type control valve, and also to supply pressure oil from the control valve to a cylinder for lifting and lowering ground work equipment. The present invention relates to a structure for lifting and lowering a ground work device for a working vehicle, in which a branch flow path that communicates with an accumulator is provided in a flow path.

[Conventional technology]

For example, in a full culm loading type compiler, which is an example of a work vehicle, the pre-reaping processing unit, which is a ground work device, is manually raised and lowered due to the structure described above, and the accumulator is used to raise and lower the ground work device from the ground. It has a built-up pressure absorption function that absorbs sudden pressure fluctuations from the cylinder when the ground work equipment comes into contact with the ground when the work is performed while being held at a set height.

[Problem that the invention seeks to solve]

There is no particular problem with the above-mentioned structure in a field with relatively large unevenness and undulations where rice, wheat, etc. are planted, but when performing reaping and harvesting work in a field with relatively large unevenness and undulations where soybeans are planted, the operator must The manual switching control valve is operated at the appropriate time so that the reaping pre-processing section follows the field, but due to the above-mentioned pressure accumulation absorption action of the accumulator, the supply and discharge of pressure oil to the cylinder is delayed. There was a slight delay in the preprocessing section's response to the control valve operation.

Therefore, the third method to solve this problem is
As shown in Figures 1 and 4, the accumulator 1
A variable needle valve 18 is provided in a branch flow path 15 communicating with 6.
It is also possible to consider a structure in which the accumulator 16 can be switched to an activated and inactive state by providing an on-off valve 19. However, with this, the variable needle valve and on-off valve can be operated with the variable needle valve and on-off valve closed, and then returned to the open state. Sometimes people forget to do this, and they end up doing other work, and the sudden pressure fluctuations caused by contact with the field surface are not absorbed by the accumulator, which could lead to damage to various parts.

An object of the present invention is to provide the above-mentioned lifting/lowering operation structure for ground work equipment using an accumulator, which is capable of switching the accumulator between active and inactive states, and is capable of absorbing slight pressure fluctuations even when the accumulator is in an inactive state. The goal is to create a structure that looks like this.

[Means for solving problems]

A feature of the present invention is that in the above-mentioned lifting operation structure for a ground work device for a work vehicle, the branch flow path communicating with the accumulator is set in two states: a first communication state with a large opening and a second communication state with a small opening. The operation and effects are as follows.

[Effect]

When the switching valve is placed in the first communicating state with a large opening, the accumulator operates normally as before. or,
If the second communication state is set to a small opening, the accumulator will hardly operate, and the following speed of the ground work equipment will improve when the manual switching control valve is operated, but the branch flow to the accumulator will not be completely activated. Since it is not shut off, some pressure fluctuations are absorbed by the accumulator.

〔Effect of the invention〕

As explained above, in a hydraulic ground work equipment lifting/lowering operation structure that uses a manual switching control valve, the accumulator can be switched between activated and deactivated states, and even in the deactivated state, slight pressure fluctuations are avoided. This has improved workability and safety.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a working vehicle that is an embodiment of the present invention will be described based on the drawings, using a full-culm input type combine harvester as an example thereof.

As shown in Figure 2, there is a rotating reel 1 that scrapes the planted grain culms toward the rear of the machine, a reaping device 2 that reaps the raked grain culms, and a reaping device 2 that receives the harvested grain culms and collects them in the center and moves them to the rear of the machine. A reaping pre-processing section 5, which is a ground working device, is equipped with an auger 3 for sending out the grain, and a feed conveyor 4 for conveying the harvested grain culm to the rear of the machine with the ears in front, and is mounted at the front of the machine so that it can be raised and lowered by a hydraulic cylinder 10. In addition to connecting, the pre-cutting processing section 5
A whole-culm input type threshing device 6 for threshing the harvested grain culm supplied from the culm, and a grain tank 7 for storing the grain after the threshing process are installed on the upper part of the machine, and a crawler traveling device 8 and a driving section 9 are installed in the machine. It is installed on the front left side to form a full culm input type combine harvester.

Next, the pressure oil supply system to the hydraulic cylinder 10 for raising and lowering the reaping pretreatment section 5 to which the present invention is applied will be described in detail.As shown in FIG. Driven pump 1
Pressure oil from 2 is supplied to 3, which is a manually operated control valve 13.
It is supplied to the above-mentioned single-acting hydraulic cylinder 10 via a position switching valve. and the 3-position switching valve 13
Branch flow path 1 from flow 14 to hydraulic cylinder 10
5 is provided, and an accurator 16 is provided in this branch flow path 15.
are connected.

Furthermore, as shown in FIG.
A two-position switching valve 17 with a fully open position 17a and a throttle position 17b is provided, and a two-position switching valve 17 with a throttle position 17b is provided. This switching valve 17 is set to the fully open position 17 during harvesting of rice and wheat.
A is switched to the aperture position 17b to allow the accumulator 16 to operate smoothly, and when harvesting soybeans, etc. or when driving on a veneer, the throttle position is switched to the aperture position 17b to keep the pre-harvest processing section in a substantially fixed state with an appropriate buffering function. Use it.

[Brief explanation of the drawing]

The drawings show an embodiment of the lifting operation structure for the ground working device of a working vehicle according to the present invention, and FIG. 1 is a hydraulic circuit diagram of the lifting operation system of the reaping pre-processing section of the ground working device, and FIG. 2 is an example of the working vehicle. FIG. 3 is a diagram showing a first comparative example to the present invention, and FIG. 4 is a diagram showing a second comparative example to the present invention. 10...Cylinder, 12...Pump, 13...
Control valve, 14... Channel, 15... Branch channel, 16
...Accumulator, 17...Switching valve.

Claims (1)

[Claims] 1 Pressure oil from the pump 12 is supplied to the cylinder 10 for lifting and lowering the ground work equipment via the manual switching control valve 13.
A structure for lifting and lowering a ground working device for a working vehicle, which is provided with a branch passage 15 communicating with an accumulator 16 in a passage 14 from the control valve 13 to the cylinder 10, the branch passage communicating with the accumulator 16. A structure for lifting and lowering a ground work device for a work vehicle, in which a flow path 15 is provided with a switching valve 17 that can switch between only two states: a first communication state with a large opening and a second communication state with a small opening.