JPH0246642Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention always keeps the work equipment attached to the three-point linkage work equipment mounting device horizontal regardless of the unevenness of the field. This invention relates to the operating speed of a control actuator of a horizontal control device for an agricultural tractor that is configured to level the finished surface.

(b) Prior Art Conventionally, the technology for controlling the left and right inclination angle of a working machine attached to a tractor is known to the public.

(c) Problems that the invention aims to solve However, the working speed of a tractor is not constant depending on the content of the work, and while plowing work etc. is done at a fairly high speed, mulching work etc. is done at very low speeds such as creep speed. They do the work.

Despite these differences in working speed, if the operating speed of the actuator to keep the work equipment level is always constant, the left and right side of the agricultural tractor will be affected during high-speed plowing work, etc. The horizontal control of the work equipment is unable to follow the shake, and proper work finishing performance cannot be obtained.

On the other hand, in low-speed work such as mulching work or earth-filling work, if the actuator speed is too high, control becomes unstable.

In addition, in the conventional technology, the hydraulic cylinder for horizontal control of the work equipment was installed only on one of the left and right lift links, so it was difficult to maintain the level by raising and lowering only one side of the work equipment. The problem was that the amount of expansion and contraction of the hydraulic cylinder was large, making it easy for hunting to occur in control.

Furthermore, since there was no mechanism for setting and determining the setting speed signal b, the horizontal control of the work machine was performed over the entire range of tractor speeds. However, it is not necessary to perform horizontal control at high speeds such as when traveling on the road or when moving between fields, and in this invention, the set speed signal b is set and the judgment circuit C is used at speeds other than a certain range. The system is configured so that horizontal control is not performed based on the judgment, or automatic control of hydraulic cylinders for speed and horizontal control is not performed.

The present invention is designed to solve these problems.

(d) Means for solving the problem The purpose of the present invention is as described above. Next, the configuration for achieving the purpose will be explained.

A flow divider 29 and an electromagnetic throttle valve 25 are installed on the circuit of a hydraulic pump 28 driven by the engine 2.
A flow divider 24 is arranged, and the flow divider 29 branches the pressure oil to the hydraulic cylinder 27 for rotating the lift arms 15, 15 and the electromagnetic throttle valve 25, and the pressure oil after passing through the electromagnetic throttle valve 25 is transferred to the flow divider. In the configuration in which 24 branches and supplies the left and right hydraulic cylinders 16L and 16R for tilt control, a judgment circuit C is configured to compare and judge the signal of the vehicle speed detection sensor S and the set speed signal b, and the signal from the judgment circuit C is The electromagnetic throttle valve 25 is controlled by the flow divider 24, and the amount of pressure oil reaching the flow divider 24 is controlled. The configuration of the embodiment shown in the drawings will be explained.

Fig. 1 is an overall side view of the agricultural tractor horizontal control device of the present invention, Fig. 2 is a rear view thereof,
FIG. 3 is an operational diagram of the present invention.

An engine 2 is disposed within a bonnet 1 of a tractor, a front axle bracket 3 protrudes from the lower side of the engine 2, and front wheels 4, 4 are supported on the front axle bracket 3.

A clutch housing 5 is fixed to the rear surface of the engine 2, and a transmission case 8 is fixed to the rear surface of the clutch housing 5. Rear axle housings 10, 10 are protruded from both sides of the transmission case 8, and rear wheels 9, 9 are supported on rear wheels 12, 12 supported by the rear axle housings 10, 10.

A hydraulic case 14 is mounted on the upper surface of the transmission case 8, and the lift arm 1 is placed inside the hydraulic case 14.
A hydraulic cylinder 27 for rotating the parts 5 and 15 is installed inside.

In the embodiment, the hydraulic pressure for rotating the hydraulic lift arm 15 is divided by a flow divider 29,
Hydraulic cylinders 16L and 16R, which are actuators for horizontal control of the work machine, are expanded and contracted.

The actuator is not limited to the hydraulic cylinder shown in the embodiment, but may be an electric actuator or an air actuator.

Hydraulic cylinders 16L and 16R as actuators are interposed in lift links 22L and 22R that are pivotally connected to the rear ends of the lift arms 15, and the lower ends of the hydraulic cylinders are pivotally connected to the middle portions of lower links 19L and 19R. .

Top link 20, lower link 19L, 19
A working machine such as a rotary tiller A is attached to a three-point link type working machine mounting device consisting of R. 21 is a universal joint that transmits power to the work machine.
13 is a seat.

Since the present invention controls the vehicle speed in conjunction with the operating speed of the hydraulic cylinders 16L and 16R, which are actuators, it is necessary to detect the vehicle speed.

The vehicle speed detection sensor shown as S1 in FIG. 1 detects the rotation speed of the rear axles 12L and 12R,
This value is changed into an electrical signal such as voltage and transmitted.

A vehicle speed detection sensor indicated by S2 detects the speed stage based on the movement of the main shift lever 6 and the auxiliary shift lever 7, and senses the speed in stages.

The signals sensed by these vehicle speed detection sensors S1 and S2 are sent to the judgment circuit C shown in FIG. be.

The electromagnetic throttle valve 25 converts changes in voltage into the strength of a solenoid, moves the spool linearly against a spring, and limits the amount of pressurized oil.

In FIG. 3, pressure oil is discharged by a hydraulic pump 28 driven by the engine 2, and pressure oil for a conventional lift arm that simply raises and lowers the work machine using a flow divider 29, and pressure oil for the horizontal control of the work machine according to the present invention. It is branched into pressure oil for equipment.

26 is a hydraulic directional control valve for the lift arm 15;
Reference numerals 30 and 31 are external extraction holes for pressure oil controlled by the hydraulic directional control valve 26.

The pressure oil sent from the flow divider to the hydraulic cylinders 16L, 16R for horizontal control passes through the electromagnetic throttle valve 25 mentioned above, and then goes through the flow divider 24 again to the hydraulic directional control valves 23L, 23R for the left and right hydraulic cylinders 16L, 16R. Branched out.

The hydraulic directional control valves 23L and 23R are controlled by a tilt sensor a that detects the tilt of the working machine, and extend and retract the hydraulic cylinders 16L and 16R, so that the working machine is always kept level regardless of whether the agricultural tractor tilts left or right. The hydraulic cylinder is operated to expand and contract in the direction of

Then, the hydraulic cylinder 1 is controlled by the electromagnetic throttle valve 25.
Since the flow rate of the pressure oil flowing into 6L and 16R changes, the expansion and contraction speed of the hydraulic cylinder as an actuator changes with the vehicle speed. When the actuator is electric, a variable current control mechanism can constitute a variable mechanism.

(f) Effects of the invention Since the invention is constructed as described above, it has the following effects.

First, in the conventional technology, the hydraulic cylinder for work horizontal control was installed only on one of the left and right lift links, so it was difficult to level the work equipment by raising or lowering only one side of the work equipment. However, there was a problem in that the amount of expansion and contraction of the hydraulic cylinder was inevitably large, resulting in a reduction in hunting in the control.

The present invention has been able to solve this conventional problem by reducing the number of left and right hydraulic cylinders 16L and 16R to two.

Secondly, since there was no conventional mechanism for setting and determining the set speed signal b, horizontal control of the work machine was performed over the entire range of tractor speeds. However, it is not necessary to perform horizontal control at high speeds such as when traveling on the road or when moving between fields, and in this invention, the set speed signal b is set and the judgment circuit C is used at speeds other than a certain range. It is configured so that horizontal control is not performed based on the judgment, or automatic control of hydraulic cylinders for speed and horizontal control is not performed.

This makes it possible to horizontally control the work machine only within the working speed range.

Thirdly, the speed of horizontal and vertical movement for horizontal control of the work equipment can be changed according to the speed of the tractor, so when the work speed is high, such as when plowing, the actuator operating speed can also be increased. Since the work equipment can also move up and down to follow the speed, it is possible to always improve horizontal finishing even when the work speed is high, and unlike conventional methods, the actuator does not extend or contract to keep the work equipment horizontal. This eliminates the problem of the work machine tilting in the next direction before the end of the process, resulting in unstable control no matter how long the process lasts.

Fourth, it is possible to eliminate problems such as when moving too quickly and creating terraces in the ridges when moving at low speeds, such as when burying soil or mulching.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of the agricultural tractor horizontal control device of the present invention, Fig. 2 is a rear view thereof,
FIG. 3 is a control operation diagram of the present invention. a... Work equipment tilt detection sensor, S1, S2...
...Vehicle speed detection sensor, A...Rotary tillage device, 15L, 15R...Lift arm, 16L,
16R...Hydraulic cylinder for horizontal control of work equipment,
19L, 19R...Lower link, 22L, 22
R... Lift link, 24... Flow divider, 25... Electromagnetic throttle valve, 27... Hydraulic cylinder, 28... Hydraulic pump, 29... Flow divider.

Claims (1)

[Scope of utility model registration request] A flow divider 29 and an electromagnetic throttle valve 25 are installed on the circuit of the hydraulic pump 28 driven by the engine 2.
A flow divider 24 is arranged, and the flow divider 29 branches the pressure oil to the hydraulic cylinder 27 for rotating the lift arms 15, 15 and the electromagnetic throttle valve 25, and the pressure oil after passing through the electromagnetic throttle valve 25 is transferred to the flow divider. In the configuration in which 24 branches and supplies the left and right hydraulic cylinders 16L and 16R for tilt control, a judgment circuit C is configured to compare and judge the signal of the vehicle speed detection sensor S and the set speed signal b, and the signal from the judgment circuit C is A working machine horizontal control device for an agricultural tractor, characterized in that it is configured to control an electromagnetic throttle valve 25 and control the amount of pressure oil reaching a flow divider 24.