JPS63206534A - Oil-pressure device for parallel movement of attachment of agricultural loader - Google Patents

Abstract

PURPOSE:To perform construction work simply at low cost by using a selecting valve for parallel movement of two-position and four-connection as an additional valve device for attachments with the vertical drive of lift arm to perform parallel movement. CONSTITUTION:When an attachment 6 is raised in parallel, a dump operation valve 13 is set to neutral position F and a lift operation valve 12 is set to a rising position A. At the same time, the operation switch is turned ON. A selection valve 16 is switched from a parallel movement stop position J to a parallel moving operation position K, and the oil chamber 5a of a parallel moving cylinder 5 is led to the scooping drive side oil chamber 7b of the lift cylinder 4. The dump drive side oil chamber 7a is connected to the rising drive side oil chamber 4a of the lift cylinder 4. Pressure oil from a pump 11 enters the oil chamber 4a and the oil chamber 8b of an auxiliary valve device 15 and goes into the oil chamber 7a through the selection valve 16b, and the oil from the chamber 7b goes into the oil chamber 5a. The oil from the cylinder 7 enters the oil chamber 5a and the cylinder 7 is extended. The attachment 6 rises in parallel.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to the attachment of an agricultural loader (for example, a packet, a hein force vine, or an elevated work platform) that is removably mounted on a tractor to perform required operations. The present invention relates to a hydraulic device for performing a parallel movement operation while remaining substantially horizontal or in an inclined state, depending on the situation.

<Prior Art> Many proposals have been made for this type of hydraulic system, and for example, as shown in FIGS. Such a hydraulic system is disclosed.

It is the hydraulic pump 1 that constitutes the hydraulic system of the agricultural loader 1.
1, the lift cylinder 4 is connected so as to be telescopically operable with a displacement valve 12a, and the dump cylinder 7 is connected so as to be telescopically operable with a dump displacement valve 13b. is attached so that it can be mechanically expanded and contracted, and the parallel movement cylinder 5 has a 7-to-operation valve 12g.
It is connected to the dump cylinder 7 through a parallel movement operation circuit formed integrally with the lift operation valve 12a, and when the lift operation valve 12a is operated to expand and contract the 7 cylinder 4 and drive the 97 torment arm 3 up and down. The parallel movement cylinder 5 is expanded and contracted to actuate the dump cylinder 7, and the attachment 6 is moved in parallel while being oscillated.

That is, the lift operation valve 12a is configured to be in a parallel upward position and to be switchable between a stop position M and a parallel upward position N.
When the attachment 6 is in the parallel raising position and the parallel lowering position N, the oil chamber 5a of the parallel displacement cylinder 5 and the scoop drive side oil chamber 7b of the dump cylinder 7 are communicated with each other, and the The dump drive side oil chamber 7a and the upward drive side oil chamber 4a of the lift cylinder 4 are communicated with each other, whereas in the stop position M, the oil chamber 5a of the parallel movement cylinder 5 and the scoop drive side oil of the dump cylinder 7 are communicated with each other. While cutting off the communication with the chamber 7b, the oil chamber 5 on the Gump drive side
It is also configured to cut off communication between the lift cylinder 4 and the upward drive side oil chamber 4a of the lift cylinder 4.

In addition, in these figures, the code|symbol 24 is a relief valve, and 25 is a tank.

<Problems to be Solved by the Invention> In the above conventional example, the +77)ti operating valve 12a is configured as a 3-position switching valve exclusively for parallel movement operation, and the tractor is equipped as a standard hydraulic system for the agricultural loader. It is not possible to use a 3-position switching valve as it is as a 7-to-operation valve, and since a 3-position 7-connection valve with an integrated circuit for parallel movement operation is used, the valve structure is complicated. It is possible to implement it cheaply.

In addition, the valve device 12a that is added for parallel movement of the attachment cannot be made small, so if it is installed in a narrow space, a lot of work is required for its installation and piping, making it impossible to improve the efficiency of assembly. .

Furthermore, when the lift arm 3 is raised or lowered by the lift operation valve 12a, the attachment 6 always moves in parallel, so it is impossible to lift the attachment 6 while keeping its posture fixed on the lift arm.

Moreover, since the lift operation valve 12a is additionally provided as a dedicated valve, it cannot be provided at a position that is easy to operate from the beginning, and operability is poor.

<Means for Solving the Problems> The present invention has been made to solve the above problems.
The conventional hydraulic system for parallel movement operation of an attachment is improved as follows.

That is, the lift operation valve 12 that is standard equipment in the agricultural loader hydraulic system is used as is, and the parallel movement operation selection valve 16 is provided independently from the lift operation valve 12.

This selection valve 16 for parallel movement operation is provided with a parallel movement operation position and a parallel movement body normal position 1ifJ, and this selection valve 1
At the parallel movement operation position 6, the oil chamber 5a of the parallel movement cylinder 5 and the scoop drive side oil chamber 7b of the dump cylinder 7 are communicated, and the dump drive side oil chamber 7a of the dump cylinder 7 is connected to the dump drive side oil chamber 7a of the dump cylinder 7. While the selection valve 16 communicates with the oil chamber 4a on the upward drive side, the parallel movement rest position J of the selection valve 16 communicates with the oil chamber 5a of the parallel movement cylinder 5 and the dump cylinder 7.
While cutting off communication with the scoop drive side oil chamber 7b,
It is characterized in that it is configured to also cut off communication between the dump drive side oil chamber 7a and the lift cylinder 4's upward drive side oil chamber 4a.

<Function> In the present invention, the lift operation valve 12 that is standard equipment in the agricultural hydraulic system is used as is, and the parallel movement operation selection valve 16 is provided independently from the lift operation valve 12.
This selection valve 16 basically consists of a two-position switching valve having a parallel movement operation position and a parallel movement rest position J. When the attachment 6 is moved in parallel, this selection valve 16 is operated in parallel movement. Position K is selected, and the lift arm 3 is raised and lowered by the lift operation valve 12.

When lifting the attachment 6 with its posture fixed on the lift arm 3, the selection valve 16 is selected to the parallel movement rest position J to block the movement of the dump cylinder 7, and the lift operation valve 12 is operated to lift the Only arm 3 is raised and lowered.

<Embodiment> FIGS. 1 and 2 are schematic diagrams of a hydraulic system showing an embodiment of the present invention. FIG. 1 shows an aspect when the attachment 6 is raised in parallel, and FIG. This shows how it is lowered.

In these figures, reference numeral 1 indicates an agricultural loader, and this agricultural loader 1 is replaceably mounted on a tractor (not shown) via a base 2, and its base end is pivoted to the base 2 so that it can move up and down. Lift arm 3 movably provided and lift arm 3
A double-acting lift cylinder 4 that lifts and oscillates the 1J7 tow arm 3, a single-acting parallel displacement cylinder 5 that expands and contracts in accordance with the 1J7 tow arm 3's up and down swing, and a pivot cylinder that can be detachably attached to the tip of the 1J7 tow arm 3. It includes a supported attachment (packet) 6 and a double-acting dump cylinder 7 that swings the attachment 6 up and down.

This attachment parallel movement operation hydraulic system is a hydraulic pump 11 that is standard equipment of the hydraulic system of the above-mentioned agricultural loader.
In addition to the 7-t operation valve 12 and the dump operation valve 13, the auxiliary valve device 15 is equipped with a parallel movement operation selection valve 16, which is a feature of the present invention. There is.

That is, the hydraulic pump 1 that constitutes the hydraulic system of the agricultural loader 1
1, the IJ7 cylinder 4 is connected so as to be telescopically operable with the 7F operating valve 12, and the dump cylinder 7 is telescopically connected with the dump operating valve 13, and the parallel displacement cylinder 5 is mechanically connected to the lift cylinder 4. The cylinder 5 for parallel movement is connected to the dump cylinder 7 via the selection valve 16 for parallel movement operation, and the lift cylinder 4 is expanded and contracted by operating the lift operation valve 12 to raise and lower the lift arm 3. In the driving state, the parallel movement cylinder 5 expands and contracts in response to this, and the dump cylinder 7 is actuated so that the attachment 6 is moved in parallel while being oscillated. There is.

The auxiliary valve device 15 is configured independently from the lift operation valve 12, and is provided between parallel displacement oil passages 8 and 9 that connect the parallel displacement cylinder 5 and the Gump cylinder 7, as shown in FIG. As such, the parallel movement operation selection valve 16 is comprised of a general-purpose two-position switching valve.

This selection valve 16 has a parallel movement operation stop position J and a parallel movement operation position, and is configured so that it can be controlled to switch between two positions with a selection valve operation switch 17.
The attachment 6 can be moved in parallel by turning on a switch 17 as appropriate while operating the control valve 12.

To raise the attachment 6 in parallel, as shown in Fig. 1, leave the dump operation valve 13 in the neutral position F, move the lift operation valve 12 to the lift position A, and turn the operation switch to any position where you want to raise the attachment 6 in parallel. Turn on 17. Then, the selection valve 16 is switched from the parallel movement stop position J to the parallel movement operation position K, and the oil chamber 5a of the parallel movement cylinder 5 is switched.
and the scoop drive side oil chamber 7b of the dump cylinder 7 communicate with each other, and the dump drive side oil chamber 7a of the dump cylinder 7 communicates with the scoop drive side oil chamber 7b of the dump cylinder 7.
and the upward drive side oil chamber 4a of the lift cylinder 4 communicate with each other. In this state, the pressure oil from the pump 11 is transferred to the upward driving side oil chamber 4a of the lift cylinder 4 and the oil passage 8 of the auxiliary valve device 15.
The oil flowing into the tank 25 and flowing out from the descending side oil chamber 4b of the lift cylinder 4 returns to the tank 25.

The pressure oil that has flowed into the oil passage 8b flows into the dump drive side oil chamber 7a of the dump cylinder 7 via the selection valve 16, and the oil that has flowed out from the scoop drive side oil chamber 7b passes through the selection valve 16 and is transferred to the parallel displacement cylinder. 5 into the oil chamber 5a.

In addition, since the oil chamber 5a of the parallel displacement cylinder 5 is filled with oil, the return oil from the dump cylinder 7 flows into the oil chamber 5a by the amount that the parallel displacement cylinder 5 has expanded, and the dump cylinder 5 is filled with oil. The cylinder 7 expands by that amount. This causes the attachment 6 to rise in parallel. Note that the cross-sectional area of the cylinder 17 of the dump cylinder 7 and the cross-sectional area of the cylinder for parallel movement are appropriately set so as to maintain the parallel movement of the attachment 6.

To lower the attachment 6 in parallel, as shown in Figure 2, leave the dump operation valve 13 in the neutral position F, move the lift operation valve 12 to the lowered position C, and move it to any position where you want to raise it in parallel. Turn on switch 17. Then, the oil flows in the opposite direction to the above, and the attachment 6 descends in parallel.

Further, when the parallel movement of the attachment 6 is not required, the operation switch 17 can be turned off at any time to stop the parallel movement of the attachment 6, and only the lift arm can be moved up and down.

In addition, in FIGS. 1 and 2, the parallel movement operation circuit 15 includes a relief valve 19, check valves 20 and 21, and a pilot valve 22, and has various functions as described below.

The relief valve 19 is designed so that when the attachment 6 descends in parallel (Fig. 2) and the dump cylinder 7 is most contracted, there is no place for the oil in the parallel movement cylinder 5 to escape.
This relief valve 19 is used to return oil to the tank 25.

The check valve 20 operates when the attachment 6 rises in parallel (
(Fig. 1), when the dump cylinder 7 is extended to the maximum, the oil chamber 5a of the parallel displacement cylinder 5 becomes a vacuum state.
This check valve 20 is used to send oil to the drive oil chamber 5a.

For example, in FIG. 2, the check valve 21 and the pilot valve 22 are arranged such that when the switch 17 is turned on, the lift operation valve 12 is at the neutral position B and the dump operation valve 13 is at the scoop position E.
When switching to and operating attachment 6,
The upward drive side oil chamber 4a of the IJ7 tow cylinder 4 communicates with the dump drive side oil chamber 7a of the dump cylinder 7 via an oil passage 9b, and also communicates with the tank 31.
This is to prevent it from descending under its own weight.

That is, the pilot valve 22 is a pilot valve for the oil passage 9a and closes the oil passage 9b.

FIG. 3 shows a circuit diagram of a main part showing another embodiment of the selection valve, and this selection valve 16A is in the parallel movement stop position mJ when the oil passage 8
This differs from the previous one in that a is detoured at a neutral bow 8c and communicated with an oil passage 8b.

FIG. 4 shows another embodiment in which the selection valve 16B is composed of a 5-point and 3-position switching valve, and this selection valve 16B is equipped with a speed increasing valve mechanism for speeding up the dump operation of the dump cylinder 7. The points are different from those in the $1 diagram.

For example, when the lift operation valve 12 is switched to the neutral position B, the dump operation valve 13 is switched to the dump operation position G, and the speed increase switch 18 of the dump operation handle 28 is turned on, the selection valve 16
B becomes the speed increase position H, and the return oil in the scoop drive side oil chamber 7b of the dump cylinder 7 flows into the dump drive side oil chamber 7a of the dump cylinder 7 via the selection valve 16B, and the dump speed of the dump cylinder 7 is increased. speed up.

FIG. 5 shows another embodiment in which a double-acting lift cylinder 4 and a single-acting parallel displacement cylinder 5 are integrally assembled, and other points are the same as FIG. 1.

FIG. 6 shows another embodiment in which the suspension ring 4 is a single-acting type, and a lift operation valve 12A corresponding to this is shown.
Although some of the circuits in FIG. 1 have been changed, other points are the same as in FIG.

FIG. 7 shows another embodiment in which a single-acting lift cylinder 4 and a single-acting parallel displacement cylinder 5 are integrally assembled, and other points are the same as those in FIG. 6.

<Effects of the Invention> Since the present invention is configured and operates as described above, it has the following effects.

B. In the basic structure of the agricultural rogue's hydraulic system, in the conventional example shown in Figures 8 and 9, a lift operation valve is used as an additional valve device to move the attachment in parallel when the toe arm is driven up and down. A 3-position, 7-connection valve integrally combined with a parallel movement operation circuit was used, and the valve structure was complicated, whereas the present invention basically uses a 2-position, 4-connection parallel movement operation selection valve. Since it is only used, the valve structure is simple and can be implemented at low cost.

The valve device added for parallel movement of the mouth and attachment is basically a simple valve with a 2-position, 4-connection structure in the present invention, compared to the conventional valve with a complicated 3-position, 7-connection structure. Since the valve is small and the number of piping connections can be reduced, the valve can be installed comfortably even in a narrow space, and the labor required for installation and piping is reduced, increasing the work efficiency of assembly. It depends.

C. By operating the lift operation valve with the parallel movement operation selection valve in the parallel movement rest position, only the lift cylinder is operated and the attachment is fixed in the lift arm* l) 7. Can be driven.

2. As the lift operation valve, the 3-position directional control valve that is already equipped as standard on the tractor at a position that is easy to operate is used as is, so it is possible to carry out vertical rolling easily and efficiently.

[Brief explanation of the drawing]

FIGS. 1 and 2 are hydraulic circuit diagrams of a hydraulic system according to an embodiment of the present invention, with FIG. 1 showing a parallel rise and FIG. 2 showing a parallel fall. Fig. 3 is a main circuit diagram showing another embodiment of the selection valve, Fig. 4 is a hydraulic circuit diagram with yet another selection valve, and Fig. 5 shows a double-acting lift cylinder and a single-acting parallel displacement cylinder. Fig. 6 is a circuit diagram of another embodiment in which the lift cylinder and parallel movement cylinder are assembled as a pair, Fig. 7 is a circuit diagram of another embodiment in which the lift cylinder and the parallel movement cylinder are configured as single-acting types, and Fig. 7 is the lift cylinder and parallel movement cylinder. FIG. 7 is a circuit diagram of another embodiment in which the cylinders are each of a single-acting type and are assembled together. FIGS. 8 and 9 are hydraulic circuit diagrams showing conventional examples, respectively, with FIG. 8 showing the state during parallel upward movement, and FIG. 9 showing the state during parallel downward movement. 1... Agricultural loader, 3... Lift arm, 4...
... Lift cylinder, 4a... Lifting drive side oil chamber,
5... Parallel movement cylinder, 5a... Oil chamber, 7
...Dump cylinder, 7a...Gunbu drive side oil chamber, 7b...Rake drive side oil chamber, 8 (8a...
8b)・9(9a・9b)...Oil passage, 11...
Pump, 12... Lift operation valve, 13... Dump operation valve, 16... Selection valve (parallel movement operation circuit). -16= Figure 4 7b77a Figure 3 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. Hydraulic pump 11 constituting the hydraulic system of agricultural loader 1
In contrast, the lift cylinder 4 is connected so as to be telescopically operable with a lift operation valve 12, and the dump cylinder 7 is connected so as to be telescopically operable with a dump operation valve 13.
A parallel displacement cylinder 5 is attached to the cylinder 5 so as to be mechanically driven to expand and contract, and the parallel displacement cylinder 5 is connected to the dump cylinder 7 via a parallel displacement operation circuit, and the lift cylinder 4 is expanded and contracted by operating the lift operation valve 12. When the lift arm 3 is moved up and down, the parallel movement cylinder 5 expands and contracts to actuate the dump cylinder 7 to move the attachment 6 in parallel while adjusting its swing. In the hydraulic system for parallel movement operation of an attachment of an agricultural loader, the circuit for parallel movement operation is composed of a selection valve 16 for parallel movement operation independent of the lift operation valve 12, and this selection valve 16 is configured as follows. The selection valve 16 has a parallel movement operation position and a parallel movement rest position J, and the parallel movement operation position K of the selection valve 16 connects the oil chamber 5a of the parallel movement cylinder 5 and the scoop drive side oil chamber 7b of the dump cylinder 7. At the same time, the dump drive side oil chamber 7a of the dump cylinder 7 and the lift drive side oil chamber 4a of the lift cylinder 4 are communicated with each other. It is configured to cut off communication between the oil chamber 5a of the dump cylinder 7 and the scoop drive side oil chamber 7b of the dump cylinder 7, and also cut off communication between the dump drive side oil chamber 7a and the upward drive side oil chamber 4a of the lift cylinder 4. A hydraulic device for parallel movement operation of an agricultural loader attachment.