JPS583921Y2 - Hydraulic extraction structure for agricultural tractors - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a hydraulic pressure extraction structure for a tractor.

A typical agricultural tractor is equipped with a hydraulic system that raises and lowers rear working equipment such as a rotary tiller. A cylinder device directional control valve is provided in the middle.

In addition to this directional control valve, a pressure regulating valve and a valve for controlling the flow rate when releasing pressure oil from the cylinder are also provided.

Some pressure regulating valves are provided in the oil passage from the pump to the directional control valve, and some are additionally provided in the oil passage between the directional control valve and the cylinder device.

Conventionally, this type of tractor has been equipped with a device that can optionally take out pressure oil from the hydraulic system for the rear working machine when a working machine that has another hydraulic system in addition to the hydraulic system for the rear working machine is attached. Ta.

For example, Utility Model No. 51-106713. Jitsukai 51-79
For models such as 902 that have an additional hydraulic pressure takeoff switching valve in the middle of the oil path that connects the directional control valve and the cylinder cap so that other hydraulic equipment can be installed, the switching valve can be installed independently. The switching valve was installed on the side of the cylinder case where the cylinder device was attached, which made the oil passage complicated, the number of parts increased, and the mounting part of the switching valve was narrow, making it difficult to operate. There were drawbacks such as the installation of tools being complicated and the operation difficult.

The purpose of this invention is to eliminate these drawbacks and inconveniences, and furthermore, to provide a hydraulic extraction structure that has a simple structure, excellent strength, and easy switching operation without increasing the number of parts when installing a hydraulic extraction structure for a tractor. The goal is to provide the following.

The characteristic configuration of the present invention is that the hydraulic cylinder device that drives the lift arm is fixedly installed on the upper surface of the aircraft body below the driver's seat, and the axial direction of the hydraulic cylinder of this hydraulic cylinder device is directed toward the driver's seat. In the hydraulic pressure extraction structure for an agricultural tractor, the cylinder cap of the hydraulic cylinder is provided at an end of the cylinder facing the driver's seat, and the cylinder cap is arranged substantially parallel to the direction in which the cylinder is located. A horizontally oriented pulse rotor is installed inside the valve rotor in a state perpendicular to the direction, and this valve rotor is configured to have two states in which the operating control valve of the hydraulic cylinder device is connected to the hydraulic cylinder device and a state in which the control valve is connected separately by a rotation switching operation of the valve rotor. The valve rotor is configured to be switched to a state in which it is communicatively connected to a hydraulic outlet oil passage for a hydraulic working device, and an operating end of the valve rotor is provided protruding from a side of the cylinder cap, and the operating end A switching operation tool from the seat is connected to the seat.

The effects of the characteristic configuration of the present invention are as follows.

(1) The valve rotor of the hydraulic pressure extraction switching valve is directly pivoted into the cylinder cap of the hydraulic cylinder device, which is firmly attached to the aircraft, so switching can be performed simply by attaching a switching operation tool to the exposed part of the valve rotor. The mechanism can be installed very easily.

(it)! Since a large force is applied to the JAftome, the valve rotor is built into the cylinder cap itself of the hydraulic cylinder device, which is firmly attached to the fuselage, with internal pivot support, and a switching operation tool is attached to the exposed end of the valve rotor. is attached, there is an advantage that the structure for switching the hydraulic pressure output for another hydraulic working device can be easily installed very firmly.

(iii) Because of the position and orientation of the valve rotor,
This hydraulic pressure output switching structure has a very low bulk when installed, and can be easily located under the seat or in a place close to this, and between the operating tool and the upper surface of the aircraft body.
Furthermore, it is easy to provide an operating space between the seat and the operating tool.

Therefore, it is easy to install the driver's seat so that it does not interfere with getting on and off the driver's seat.

Moreover, the switching operation is easy. QV) Since the switching operation tool is located below and close to the operator's hand in the driver's seat, there is an advantage that the operator in the driver's seat can easily perform switching.

Embodiments of the present invention will be described in detail below based on illustrative drawings.

FIG. 1 shows an agricultural tractor 10 in which a rotary tiller 2 is connected to the rear part of the vehicle body, and a front loader 3 is connected to the front part.

A rotary tillage device 2, which is the most standard set for this type of agricultural tractor, can be raised and lowered by a hydraulic cylinder device 4 built into the vehicle body and a lift arm 5 interlocked with the hydraulic cylinder device 4.

This hydraulic cylinder device 4 is fixedly installed on the upper surface of the aircraft body below the driver's seat 16, and the axial direction of the hydraulic cylinder of the hydraulic cylinder device 4 is arranged approximately parallel to the direction in which the driver's seat 16 faces. ing.

The front loader 3 is set as required and has a hydraulic cylinder device 10.

The husband's hydraulic cylinder devices 4 and 10 are equipped with an agricultural tractor 1.
Pressure oil is supplied from a pump 6 provided in the engine section of the rotary tiller 2 and the front loader 3, and the rotary tiller 2 and front loader 3 can be raised and lowered by hydraulic pressure.

Each hydraulic cylinder device 4, 10 is arranged as shown in the circuit diagram shown in FIG. 7, and a directional control valve 9 for operating each hydraulic cylinder device 4, 10 from a pump 6 provided in the engine section.
Pressure oil is supplied to each hydraulic cylinder device 4, 10 via a rotary type oil pressure extraction switching valve 8.

A pressure regulating valve is provided between the pump 6 and the directional control valve 1, and a working machine 2,
A flow rate control valve is provided which can adjust the speed at which each of the working machines 2 and 3 falls and descends when the directional control valve 7 is operated to lower the working machines 2 and 3.

Since the pressure regulating valve and the flow rate controlling valve can be designed to be compact, they can be arbitrarily placed in the middle of the circuit.

The hydraulic pressure extraction switching valve 8 is provided in a cylinder cap 4a located on the front side of the hydraulic cylinder device 6 as shown in FIGS. 2 to 6, and the cylinder cap 4a has a main passage communicating with the cylinder inner hole 4b. a, an oil extraction path b1 connecting the oil supply pipe to the hydraulic cylinder device 10 of the second working machine 3, and a directional control valve 7 provided on the side of the hydraulic cylinder device 4.
A supply oil passage C leading to the cylinder is formed, and a pulp rotor 9 insertion hole is formed which is orthogonal to the cylinder axis and horizontally oriented, into which the pulp rotor 9 is rotatably fitted. has been done.

As shown in FIGS. 4 and 6, this pulp rotor 9 is supplied with switching oil from a communication oil passage 9a leading to the supply oil passage C, a switching oil passage 9b leading to the main oil passage a, and a communication oil passage 9a leading to the oil extraction passage. A center oil passage 9c is formed that communicates with the passage 9b, and even when the pulp rotor 9 is rotated, the communication oil passage 9a remains on the side of the communication oil passage 9a.
An annular groove 11 is formed so that the groove does not become blocked.

One end of the pulp rotor 9 protrudes to the side of the cylinder cap 4a, and a switching operation tool 12 is fixed thereto.

Further, the cylinder cap 4a is provided with a positioning device 13 for the pulp rotor, and two notches 1 formed on the circumferential surface of the spring ball 14 and the pulp rotor 9 are provided.
The switching position of the pulp rotor 9 is set by 5a and 15b.

When the engine of the above-mentioned agricultural tractor 1 is started, the pump 6 is activated, and the lubricating oil from the transmission case is sucked up and reaches the directional control valve 7.

When the direction control valve 7 is operated "up" (to the right in Fig. 7), the pressure oil passes through the check pulp of the flow control valve, passes through the hydraulic pressure extraction switching valve 8, and is transferred to the hydraulic cylinder device 4 for the rear working machine 2.
is sent to move the piston to the right and lift arm 5
rises.

When the directional control valve 7 is returned to the "neutral" position, the cylinder inner hole 4
The pressure oil b is contained and the lift arm 5 is fixed at that position.

When the directional control valve 7 is operated "down" (leftward in Fig. 7), the pressure oil from the pump 6 is returned directly from the directional control valve 7 into the transmission case, and the pressure oil in the cylinder inner hole 4b is transferred to the rear part. As the piston moves to the left due to the load of the machine 2, the piston passes through the small hole of the flow control valve, passes through the direction control valve 7, and returns to the mission case.

The size of the small hole in the flow control valve can be arbitrarily adjusted using an adjustment screw.

Therefore, the falling speed of the work implement 2 can be adjusted by this flow rate control valve.

When setting the second working machine 3 such as a front loader, operate the hydraulic pressure output switching valve 8 (in Fig. 6, the pulp rotor 9
90 counterclockwise rotation), the switching oil passage 9b is connected to the take-out oil passage.

Then, when the direction control valve 7 is operated in the same manner as described above, the second working machine 3 is operated up and down.

At this time, the rear hydraulic cylinder device 4 does not operate.

Moreover, when it is desired to operate the rear working machine 2, the second working machine 3 is fixed at the required height by operating the direction control valve 7, and then the switching can be easily done by operating the hydraulic pressure take-out switching valve 8. can.

Note that when the hydraulic cylinder devices 4 and 10 are fixed, if an abnormally high pressure occurs in the cylinder inner hole 4b due to vibrations caused by the running of an agricultural tractor, etc., the directional control valve 7 and A pressure regulating valve may be provided in the oil passage between the cylinder inner holes 4b.

In short, the cylinder cap 4a of the hydraulic cylinder device 4 is provided with a rotary-type hydraulic pressure extraction switching valve 8 facing in a specified direction, and a switching lever 12 for operating the valve is provided on the side of the cylinder cap 4a. Therefore, compared to the conventional type, it is easier to operate without increasing the number of parts, the oil passage is also simplified, and the number of parts is reduced, making it possible to prevent oil leaks.

Further, since the switching lever 12 for operation is provided on the side of the cylinder cap 4a, the cylinder cap 4a does not protrude forward much and does not interfere with getting on or off the tractor or driving the tractor.

Moreover, the positioning mechanism 1 of the rotary type hydraulic pressure extraction switching valve 8
3 on the cylinder cap 4a, part of the hydraulic oil can be used to lubricate the spring ball 14, which has the effect of allowing it to be used smoothly over a long period of time.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the hydraulic pressure extraction structure for an agricultural tractor according to the present invention, and FIG. 1 is an overall side view of the agricultural tractor implementing the present invention, and FIG. 2 is a longitudinal cross-section of the hydraulic cylinder device for the rear working machine. 3 is a cross-sectional plan view of the cylinder cap section provided with the hydraulic pressure extraction switching valve, FIG. 4 is a schematic cross-sectional view taken along the line IV-IV in FIG. 3, and FIG.
FIG. 6 is a schematic cross-sectional view taken along line -V, FIG. 6 is a schematic cross-sectional view taken along line ■--■ in FIG. 3, and FIG. 7 is a hydraulic circuit diagram. 1... Agricultural tractor, 4... Hydraulic cylinder device, 4
a... Cylinder cap, 5... Lift arm, 7
... Direction control valve, 8 ... (rotary type) hydraulic pressure extraction switching valve, 9 ... Pulp rotor 12 ... switching operation tool, 16 ... seat.

Claims (1)

[Scope of utility model registration request] A hydraulic cylinder device 4 that drives the lift arm 5 is fixed to the upper surface of the aircraft body below the driver's seat 16, and the hydraulic cylinder axis direction of the hydraulic cylinder device 4 is the direction in which the driver's seat 16 is facing. This is a hydraulic pressure extraction structure for an agricultural tractor, in which a cylinder cap 4a of the hydraulic cylinder is provided at an end of the cylinder facing the driver's seat 16, and the cylinder cap 4a is arranged substantially parallel to the cylinder cap 4a.
A horizontally oriented valve rotor 9 is installed in the cylinder a in a state perpendicular to the axial direction of the cylinder, and this valve rotor 9 controls the operation/control valve 7 of the hydraulic cylinder device 4 by switching its rotation. 4 and a state in which the control valve 7 is connected to the hydraulic pressure outlet oil passage 6 for the separate hydraulic working device 3.
In addition, an operating end of the pulse rotor 9 is provided protruding from the side of the cylinder cap 4a, and a switching operation tool 12 from the seat 6 is connected to this operating end. Hydraulic extraction structure for agricultural tractors featuring: