KR102297031B1 - Angle control apparatus of link for tractor - Google Patents

Abstract

The present invention relates to a tilt control device for a tractor link device, and one end is hinged on both left and right sides of the rear of the tractor, and the other end is provided with a connecting link to which a working machine is connected, and the connecting link is provided in parallel with the connecting link at one end of the hinge A control device for adjusting the inclination of a link device including first and second hydraulic cylinders that are hinged to the rear of the tractor at the upper portion and are hinged to the other end of the tractor to rotate the connecting link up and down while expanding and contracting, is, a lifting valve for controlling the flow of hydraulic pressure to contract or extend the second hydraulic cylinder to elevate the connection link connected to the second hydraulic cylinder; It provides a tilt adjustment device of a tractor linkage comprising a; first and second one-way valves provided between the second hydraulic cylinder and the hydraulic pump to operate the second hydraulic cylinder as a single-acting or double-acting cylinder.

Description

Angle control apparatus of link for tractor

The present invention relates to a tilt control device for a tractor link device, and more particularly, to a tilt control device for a tractor link device capable of maintaining the horizontal level of the working machine by adjusting the left and right tilt of the working machine connected to the rear of the tractor.

BACKGROUND ART In general, a tractor is a work vehicle that uses traction to perform various tasks in agriculture or construction.

This agricultural tractor is used for transporting crops or mechanized agriculture, etc., a loader that can rotate up and down is provided in front of the tractor, and at the tip of the loader, any one of attachments, which are various work equipment such as bale tongs, buckets, hooks, is installed. In the rear of the tractor, various types of agricultural work tools such as a rotavator, a fertilizer spreader, a mower, and a plow are mounted and operated by receiving the power of the tractor.

In particular, a link device capable of mounting a working machine is provided at the rear of the tractor. The link device consists of an upper link that rotates up and down at the center of the rear of the tractor, and a pair of left and right lower links that rotate up and down at the lower left and right at the rear of the tractor. is provided, and the working machine is mounted on the upper link and the lower link, so that the work can be performed through a unique function of the working machine.

Such a link device at the rear of the tractor is disclosed in the domestic registered utility model No. 20-0357855 (hereinafter referred to as 'prior art document 1') and domestic registered patent no. 10-0693375 (hereinafter referred to as 'prior art document 2'). has been proposed

When the link device of the rear of the tractor proposed in the prior art documents 1 and 2 is described with reference to FIGS. ) are installed to rotate up and down, respectively.

The hydraulic cylinder provided in this way has one end hinged to the rear of the tractor (d), the other end of the piston rod opposite to the other end is hinged to one side of the connecting link (f), and the connecting link also has one end of the tractor. It is hinged to the rear (e), and the other end is provided with a working machine connected.

Accordingly, the connecting link is provided in a structure in which the connecting link rotates up and down by the expansion and contraction operation of the hydraulic cylinder, and the working machine is provided in a structure in which the working machine is integrally rotated up and down by the connecting link.

That is, Fig. 1 (a) shows a state in which the connecting link is raised while the hydraulic cylinder is contracted, and Fig. 1 (b) is a state in which the connecting link is lowered as the hydraulic cylinder is extended. The cylinder and the tractor are provided in the structure of a three-bar linkage by the hinge combination of (d)-(e)-(f).

However, the pair of left and right connection links are integrally operated by the hydraulic cylinder provided therein to rotate the working machine up and down. There is a problem in that the work can be done smoothly only by re-leveling the left and right sides of the working machine.

Domestic Registered Utility Model No. 20-0357855 Domestic Registered Patent No. 10-0693375

Accordingly, the present invention has been devised to solve the problems of the prior art as described above, and maintains the left and right horizontality of the working machine connected thereto by adjusting the left and right inclination of the connecting link provided in the link device at the rear of the tractor to which the work machine is connected. An object of the present invention is to provide a tilt adjustment device for a tractor linkage that can be used.

The tilt adjustment device of the tractor linkage device according to the present invention for achieving the above object is provided with a connecting link having one end hinge-coupled to both left and right sides of the rear of the tractor, respectively, and a working machine connected to the other end, side by side with the connecting link. One end is hinged to the rear of the tractor at the upper part where the connecting link is hinged, and the other end is hinged with the connecting link to adjust the inclination of the link device including the first and second hydraulic cylinders that rotate the connecting link up and down. An regulating device comprising: a lifting valve for controlling a flow of hydraulic pressure to contract or extend a second hydraulic cylinder to elevate a connection link connected to the second hydraulic cylinder; The first and second one-way valves provided between the second hydraulic cylinder and the hydraulic pump to selectively operate the second hydraulic cylinder as a single-acting or double-acting cylinder according to the type of work; may include.

And, the lifting valve is connected to the second hydraulic cylinder and the lifting valve for supplying the hydraulic pressure by the hydraulic pump to the second hydraulic cylinder so that the connection link connected to the second hydraulic cylinder is raised through the contracting action of the second hydraulic cylinder. It may include a lowering valve for discharging the hydraulic pressure from the second hydraulic cylinder so that the connecting link connected to the second hydraulic cylinder is lowered through the extension action of the second hydraulic cylinder.

In addition, one open flow path and a closed flow path closed by the check valve are respectively provided in the rising valve and the falling valve as described above, and the open flow path and the closed flow path may be selectively provided to be connected to the hydraulic line.

In addition, a check valve for allowing hydraulic pressure to flow only from the second hydraulic cylinder to the rising valve is provided in the hydraulic line between the second hydraulic cylinder and the rising valve, and the bypass line connected to the hydraulic line bypassing the check valve is connected to the rising valve side. An orifice for preventing shock caused by hydraulic pressure supplied to the second hydraulic cylinder may be provided.

According to the inclination adjusting device of the tractor linkage device of the present invention, the work by the working machine can be smoothly performed by adjusting the left and right inclination of the connecting link provided in the link device at the rear of the tractor and maintaining the horizontal level of the working machine connected thereto parallel to the ground. There are advantages to doing.

1 (a) and (b) is a view showing a link device at the rear of the tractor according to the prior art.
2 is a cross-sectional configuration view of a link device provided at the rear of the tractor according to the present invention.
Figure 3 (a) is a view of a state in which the link device of the present invention is raised, Figure 3 (b) is a view of a state in which the link device of the present invention is lowered.
Figure 4 is a hydraulic system diagram showing a tilt adjustment device of the tractor linkage according to the present invention.
Figure 5 is a hydraulic system diagram showing the horizontal adjustment state of the link device by the adjusting device of the present invention, Figure 5a is a rising state of the link device by the contraction of the second hydraulic cylinder, Figure 5b is the second hydraulic cylinder elongation. It is the down state of the link device by

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The terms used in the present invention are terms defined in consideration of functions in the present invention, which may vary depending on the intention or custom of the user or operator, so the definitions of these terms correspond to the technical matters of the present invention and should be interpreted as a concept.

In addition, the embodiments of the present invention do not limit the scope of the present invention, but are merely exemplary matters of the constituent elements presented in the claims of the present invention, and are included in the technical spirit throughout the specification of the present invention and the scope of the claims. It is an embodiment including a substitutable component as an equivalent in the component.

In addition, optional terms in the examples below are used to distinguish one component from other components, and the components are not limited by the terms.

Accordingly, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

2 to 5b are views showing a tilt adjustment device of the tractor link device according to the present invention.

The present invention includes a link device 10 provided at the rear of the tractor, and a control device 100 for controlling the inclination thereof.

First, the link device 10 of the rear of the tractor according to the present invention is provided on both left and right sides of the frame 20 at the rear of the tractor, respectively, as shown in FIGS. 2 and 3, a rotator (aka "rotary", not shown) ) is connected to enable general tractor work, that is, tillage work, or a working machine such as a dozer (not shown) is connected to enable dozer work, or the link device 10 itself can be rotated up and down so that it can act as an outrigger. provided in the structure.

The upper coupling hole 20a to which the hydraulic cylinders 40 and 50 and the connection link 30 of the link device 10 are respectively hinged to the frame 20 at the rear of the tractor in which the link device 10 is installed to be rotated up and down. ) and a lower coupling hole (20b) are formed, and the upper coupling hole (20a) is provided to be positioned directly above the lower coupling hole (20b).

And, as shown in FIG. 2 , the link device 10 includes a pair of left and right connecting links 30 to which a working machine (not shown) is connected to an end thereof, and from the upper portion of each connecting link 30 in the longitudinal direction. It includes first and second hydraulic cylinders 40 and 50 which are provided side by side, respectively.

Here, the pair of connecting links 30 and the first and second hydraulic cylinders 40 and 50 are both provided on the left and right sides of the frame 20, respectively, but for convenience of explanation, the first in the adjusting device 100 to be described later Since it is necessary to separately explain the 2 hydraulic cylinders 40 and 50, the first and second hydraulic cylinders 40 and 50 are given separate drawing numbers, and the left and right pair of connecting links 30 are It will be collectively described as one drawing number.

This pair of connecting links 30 is hingedly coupled to both lower coupling holes 20b formed in the frame 20 at the rear of the tractor at one end thereof, while the other end thereof is fixedly coupled to the working machine, and the first and second hydraulic pressures One end of the cylinders 40 and 50 is hinge-coupled to both upper coupling holes 20a of the frame 20, and the ends of the first and second load bars 42 and 52 at the other end are connected to the connecting link 30. It is hinged to the coupling hole (coupling hole 31a) a) formed in each coupling part (coupling hole 31a) stepped upward from the upper surface of the . Accordingly, the first and second hydraulic cylinders 40 and 50 are provided side by side in the longitudinal direction of the connecting link 30 at the upper portion of each connecting link 30, and the piston 41 reciprocating linearly therein. As the first and second load bars 42 and 52 are moved in and out of the first and second hydraulic cylinders 40 and 50 by 51, both connecting links 30 are provided to rotate up and down at the same time.

On the other hand, as described above, the link device 10 including both connecting links 30 that is rotated up and down by the expansion and contraction operation of the first and second hydraulic cylinders 40 and 50 is shown in FIGS. 3 (a) and (b) As shown in, a point (d) at which one end of the hydraulic cylinders 40 and 50 is hinged to the upper coupling hole 20a of the frame 20, and a point at which one end of the connection link 30 is hinged. (e) and the load bar 42 and 52 ends of the hydraulic cylinders 40 and 50 are provided in a three-bar link structure having a hinge-coupled point (f), the hydraulic cylinders 40 and 50 The length (A) of the point (d) at which one end is hinged and the point (e) at which one end of the connecting link (30) is hinged is the point (e) at which one end of the connecting link (30) is hinged and the hydraulic cylinder ( The length (B) of the point (f) at which the load bar (42, 52) end of the 40) (50) is hinged is much smaller than the length (B) at which one end of the hydraulic cylinder (40, 50) is hinged (d) ) and the load bar 42 and 52 ends of the hydraulic cylinders 40 and 50 are provided much smaller than the length C of the fixedly coupled point f.

Therefore, even when the connecting link 30 is overloaded, the connecting link 30 not only has the durability to withstand the overload, but also the load bar of the hydraulic cylinders 40 and 50 by the three-section link structure of the present invention. (42) (52) The length from the fixedly coupled point (f) to the link end (32) of the connecting link (30) is shortened as much as possible, thereby increasing the durability of the connecting link (30) to the connecting link (30) It has the advantage of preventing breakage.

In particular, the durability that can withstand the overload acting on the connection link 30 is further increased by the flow of hydraulic pressure that operates the hydraulic cylinders 40 and 50 as a double-acting cylinder in addition to the structural characteristics of the link device 10. be able to

In addition, the adjusting device 100 according to the present invention is one of the first and second hydraulic cylinders 40 and 50 respectively provided on the left and right pair of connecting links 30 by the hydraulic system diagram as in FIG. 4 . When hydraulic pressure is supplied to the hydraulic cylinder, both hydraulic cylinders 40 and 50 are interlocked with each other to expand and contract with the same displacement, thereby both connecting links 30 are simultaneously moved and operated in the same direction and the same displacement.

Here, for convenience, the hydraulic cylinder located on the left side in FIG. 4 is referred to as a "first hydraulic cylinder 40", and the hydraulic cylinder located on the right side is referred to as a "second hydraulic cylinder 50". When the first and second hydraulic cylinders 40 and 50 are contracted at the same time, the connecting link 30 is rotated downward and the working machine connected thereto is lowered, and when the first and second hydraulic cylinders 40 and 50 are simultaneously extended The connecting link 30 is rotated upward and the working machine connected thereto is raised.

On the other hand, the control device 100, as shown in Fig. 4, the hydraulic pump 110 for supplying the hydraulic pressure to the hydraulic line by pumping the hydraulic pressure from the hydraulic tank in which the hydraulic pressure is stored, and the flow of the hydraulic pressure by the hydraulic pump 110 A lifting valve for controlling and contracting or extending the second hydraulic cylinder 50 to elevate the connection link 30 connected to the second hydraulic cylinder 50, the second hydraulic cylinder 50 and the hydraulic pump 110 It is provided between the first and second one-way valves 130 and 140 for operating the second hydraulic cylinder 50 as a single-acting or double-acting cylinder.

The hydraulic pump 110 is provided to be connected to the hydraulic tank in which the hydraulic pressure is stored, and the hydraulic pressure in the hydraulic tank is supplied by pressure to the hydraulic line.

The lifting valve includes an ascending valve 160 for raising the connection link 30 of the second hydraulic cylinder 50 and a descending valve 170 for lowering the connection link 30 of the second hydraulic cylinder 50 . .

The rising valve 160 supplies the hydraulic pressure transferred by the hydraulic pump 110 to the second hydraulic cylinder 50 and is connected to the second hydraulic cylinder 50 through the contracting action of the second hydraulic cylinder 50 . It is provided to raise the link 30, and the lowering valve 170 is connected to the second hydraulic cylinder 50 to discharge the hydraulic pressure from the second hydraulic cylinder 50 to perform the extension action of the second hydraulic cylinder 50. It is provided to lower the connection link 30 connected to the second hydraulic cylinder 50 through the.

The ascending valve 160 and the descending valve 170 are independently provided in the hydraulic line between the hydraulic pump 110 and the second hydraulic cylinder 50 to supply or discharge hydraulic pressure to the second hydraulic cylinder 50 . This is a valve that expands and contracts the second hydraulic cylinder 50 by Like the locking valve 150, it is possible to prevent a safety accident by blocking in advance that the working machine is arbitrarily descended by its own weight or hydraulic leakage.

The ascending valve 160 and the descending valve 170 are provided to be sequentially connected to the second hydraulic cylinder 50 as one hydraulic line, and as power is supplied, the hydraulic line is opened. At this time, the second hydraulic cylinder ( As for the hydraulic line of 50), an ascending or descending passage is selectively secured by the ascending valve 160 or the descending valve 170, and accordingly, the second hydraulic cylinder 50 is contracted or expanded.

The rising valve 160 and the descending valve 170 are provided with one open flow path 161 and 171 and closed flow paths 162 and 172 closed by the check valve, respectively, and these open flow paths 161 ) 171 and the closed flow passages 162 and 172 are selectively provided to be connected to the hydraulic line.

That is, the ascending valve 160 and the descending valve 170 are normally each closed flow path 162 , 172 is connected on the hydraulic line between the hydraulic pump 110 and the second hydraulic cylinder 50 to form the flow path. When power is supplied to the rising valve 160 and the descending valve 170 after being provided in a blocked state, the open flow paths 161 and 171 are connected to the hydraulic line to secure the flow path of the hydraulic line.

In particular, a plurality of check valves are provided in the closing passages 162 and 172 to open in opposite directions, that is, from the inside to the outside of each valve, thereby blocking the inflow of hydraulic pressure and closing it.

The solenoid valve 120 is a spool-type directional switching valve for diverting the flow of hydraulic pressure supplied to the hydraulic line by the hydraulic pump 110 and supplying it to the first hydraulic cylinder 40 or the second hydraulic cylinder 50 . . In particular, when the diagonally crossed flow path among the flow paths of the solenoid valve 120 is connected to the hydraulic line, the supplied hydraulic pressure is supplied to the B port of the first hydraulic cylinder 40 to the connecting link 30 and connected thereto. When the working machine is raised and power is supplied to the solenoid valve 120, the direction is changed and the linear flow path is connected to the hydraulic line and supplies the supplied hydraulic pressure to the A port of the second hydraulic cylinder 50 to the connection link 30 and this It will lower the connected working machine.

However, when adjusting the left and right inclination of the working machine as in the present invention, the solenoid valve 120 is provided in a neutral state in which the flow path is blocked, and the hydraulic line between the solenoid valve 120 and the lock valve 150 and the solenoid valve 120 ) and the hydraulic line connecting the hydraulic line between the first and second one-way valves 130 and 140 is always in a vacuum state.

The first and second one-way valves 130 and 140 are provided in the hydraulic line between the solenoid valve 120 and the second hydraulic cylinder 50 to open the flow path of the hydraulic line in only one direction. The first and second hydraulic cylinders 40 and 50 are operated as single-acting cylinders or double-acting cylinders according to the type of work of the working machine connected to the device 10 . That is, when the first and second one-way valves 130 and 140 are provided as single-acting valves, the first and second hydraulic cylinders 40 and 50 are extended by the weight of the work machine connected to the connection link 30 and the work machine And when the connecting link 30 is automatically lowered, and is provided as a double-acting valve, the working machine and the connecting link 30 are lowered only when hydraulic pressure is supplied to the second hydraulic cylinder 50 .

On the other hand, the first and second one-way valves 130 and 140 as described above are in the A port of the second hydraulic cylinder 50, as in FIGS. 4 to 5b when adjusting the left and right inclination of the working machine as in the present invention. The hydraulic line is opened only in one direction so that the discharged hydraulic pressure flows to the hydraulic tank side and reverse flow is prevented.

The lock valve 150 is provided between the first hydraulic cylinder 40 and the solenoid valve 120 to control the extension of the first and second hydraulic cylinders 40 and 50, that is, the lowering of the working machine. Only when power is supplied to 150 and the solenoid operates, the locking valve 150 is unlocked and opened.

This locking valve 150 is provided to be operated simultaneously with the solenoid valve 120 in conjunction with each other, and the lock is not released except when power is supplied to the locking valve 150 to lower the working machine. In the off-parking mode or driving mode, the power supply is cut off by the locking valve 150, so that any descent of the working machine by its own weight or hydraulic leakage is blocked in advance, thereby preventing a safety accident.

As in the present invention, when the left and right inclination of the working machine is adjusted, the lock valve 150 closes the hydraulic line to vacuum the hydraulic line between the lock valve 150 and the first hydraulic cylinder 40 , as in the present invention. By forming in the state, one end, that is, the left side of the working machine connected to the connecting link 30 on the side of the first hydraulic cylinder 40 is provided in a fixed position.

On the other hand, the lock valve 150 as described above, the first and second one-way valves 130, 140, and the rising and falling valves 160 and 170 are flow paths by the check valves 133, 143 and 153. It is provided as a valve of a puppet type structure that does not leak hydraulic pressure when shutting off the valve, so that it is possible to reliably prevent malfunction of the working machine.

In addition, the first and second hydraulic cylinders 40 and 50 have a first piston 41 of the first hydraulic cylinder 40 with reference to FIG. 4 in order to operate both cylinders with the same displacement as hydraulic pressure is supplied. The cross-sectional area of the upper surface and the lower surface of the second piston 51 of the second hydraulic cylinder 50 should be the same.

That is, the cross-sectional area of the upper surface of the first piston 41 opposite to the first load bar 42 and the lower surface of the second piston 51 with the second load bar 52, excluding the second load bar 52, The cross-sectional area is the same as each other, and the volume of the second hydraulic cylinder 50 is formed to be larger than the volume of the first hydraulic cylinder 40, so that the hydraulic pressure can act in direct proportion to both hydraulic cylinders 40 and 50. It becomes possible to satisfy the above condition.

In addition, a check valve 181 is provided in the hydraulic line between the rising valve 160 and the second hydraulic cylinder 50 , and an orifice 180 is provided in the bypass line connected to the hydraulic line by bypassing the check valve 181 . provided

The check valve 181 provided in this way opens the hydraulic line only when the hydraulic pressure acts from the second hydraulic cylinder 50 side to the rising valve 160 side to allow the hydraulic pressure to flow and to prevent the reverse flow.

In addition, the orifice 180 attenuates the transmission of shock waves such as shocks, ie, pulsations, due to hydraulic pressure supplied from the elevation valve 160 side to the second hydraulic cylinder 50 side, thereby protecting the second hydraulic cylinder 50 from the hydraulic shock. will keep you safe

The hydraulic flow by the adjusting device according to the present invention as described above and the operating relationship of the link device according thereto will be described.

As in the present invention, the hydraulic system by the adjusting device 100 is shown in Figs. 5a and 5b when the work equipment connected to the link device 10 is tilted left and right or when the tilted work machine is horizontally positioned left and right. provided together.

That is, as in FIGS. 5A and 5B , the solenoid valve 120 is provided in a neutral state, and the lock valve 150 closes the hydraulic line between the solenoid valve 120 and the first hydraulic cylinder 40 . is provided with

As a result, the left side of the working machine connected to the connection link 30 of the first hydraulic cylinder 40 is fixed in position, so that the right side of the working machine is rotated up and down through the second hydraulic cylinder 50 to adjust the overall inclination of the working machine. .

First, as in FIG. 5A , when the right side of the working machine is to be raised, the lifting valve 160 is operated by power supply so that the open flow path 161 of the lifting valve 160 is connected to the hydraulic line. , the first and second one-way valves 130 and 140 are also operated to open their hydraulic lines in one direction.

In this state, when the hydraulic pressure is supplied by the hydraulic pump 110, the hydraulic pressure passes through the open passage 161 of the rising valve 160 and flows into the B port of the second hydraulic cylinder 50, and flows into the second piston 51 ) and the second load bar 52 are drawn into the second hydraulic cylinder 50 to contract the second hydraulic cylinder 50 .

Due to the contraction of the second hydraulic cylinder 50, the hydraulic pressure at the upper side of the second hydraulic cylinder 50 is discharged through the upper port A, and the discharged hydraulic pressure is the first and second one-way valves 130 and 140 ) is returned to the hydraulic tank through the hydraulic line opened in one direction and stored.

Accordingly, as the second hydraulic cylinder 50 is contracted as described above, the connecting link 30 provided therewith is rotated upward, and the right side of the working machine connected thereto is rotated upward and lifted to adjust the inclination of the working machine.

On the other hand, in the contracting process of the second hydraulic cylinder 50 as described above, the hydraulic pressure supplied to the B port of the second hydraulic cylinder 50 through the open flow path 161 of the rising valve 160 is applied to the check valve 181 . By means of which, the hydraulic pressure cannot pass through the hydraulic line and is supplied to the bypass line. At this time, the hydraulic pressure introduced into the bypass line passes through the orifice 180, thereby buffering and reducing shock caused by hydraulic pressure, that is, shock generated during a sudden oversupply of hydraulic pressure. be able to

After that, when you want to lower the right side of the raised working machine, as shown in FIG. 5B , the power supplied to the rising valve 160 is cut off to provide the closing flow path 162 of the rising valve 160 on the hydraulic line, , by supplying power to the descending valve 170 so that the open flow path 171 of the descending valve 170 is connected to the hydraulic line, and the first and second one-way valves 130 and 140 are in the same state as when ascending. be prepared

Accordingly, all hydraulic lines except for the hydraulic line connecting the B port of the second hydraulic cylinder 50 and the open passage 171 of the descending valve 170 are in a vacuum state.

Accordingly, the right side of the working machine is automatically lowered by its own weight, and in this process, the piston 51 and the load bar 52 of the second hydraulic cylinder 50 are drawn out and extended, and thus the second hydraulic cylinder 50 is The hydraulic pressure at the lower side is discharged to the B port of the lower part of the second hydraulic cylinder 50, and the hydraulic pressure discharged from the second hydraulic cylinder 50 passes the check valve 181 and the opening flow path 171 of the lowering valve 170. is returned to the hydraulic tank and stored.

On the other hand, as the second hydraulic cylinder 50 is extended as described above, the connecting link 30 provided therewith is rotated downward, and the right side of the working machine connected thereto is rotated downward to adjust the inclination of the working machine.

Although the present invention has been described in detail through specific examples, this is intended to describe the present invention in detail, and the present invention is not limited thereto, and by those of ordinary skill in the art within the technical spirit of the present invention. It is clear that the modification or improvement is possible.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims.

10: link device 20: frame
20a: upper coupling hole 20b: lower coupling hole
30: connection link 31: coupling part
31a: coupling hole 32: end of link
40,50: first and second hydraulic cylinders 41,51: piston
42, 52: load bar 100: control device
110: hydraulic pump 120: solenoid valve
130,140: first and second one-way valves 150: locking valve
160,170: up and down valves 161,171: open flow path
162,172: closed euro 180: orifice
181: check valve

Claims (4)

One end is hinged on both left and right sides of the rear of the tractor, and the other end is provided with a connecting link to which a working machine is connected, and the connecting link is provided in parallel with the connecting link, one end of which is hinged to the rear of the tractor at the upper part where the connecting link is hinged, and at the other end As an adjustment device for adjusting the inclination of a link device including first and second hydraulic cylinders that are hinge-coupled with a connecting link to expand and contract the connecting link up and down,
The adjusting device includes: a lifting valve for controlling the flow of hydraulic pressure to contract or extend the second hydraulic cylinder to elevate the connection link connected to the second hydraulic cylinder;
A tilt adjustment device of a tractor linkage comprising a; provided between the second hydraulic cylinder and the hydraulic pump, the first and second one-way valves selectively operating the second hydraulic cylinder as a single-acting or double-acting cylinder according to the type of work.
The method according to claim 1,
The lifting valve supplies the hydraulic pressure by the hydraulic pump to the second hydraulic cylinder so that the connecting link connected to the second hydraulic cylinder is raised through the contracting action of the second hydraulic cylinder, and the second hydraulic cylinder is connected to the second A tilt control device for a tractor link device comprising a lowering valve for discharging hydraulic pressure from the hydraulic cylinder so that the connecting link connected to the second hydraulic cylinder is lowered through the extension action of the second hydraulic cylinder.
3. The method according to claim 2,
A tilt control device of a tractor linkage device, wherein one open flow path and a closed flow path closed by a check valve are provided in the rising valve and the falling valve, respectively, and the open flow path and the closed flow path are selectively connected to the hydraulic line.
3. The method according to claim 2,
A check valve for allowing hydraulic pressure to flow only from the second hydraulic cylinder to the rising valve is provided in the hydraulic line between the second hydraulic cylinder and the rising valve. 2 A tilt control device for a tractor linkage equipped with an orifice to prevent shock caused by hydraulic pressure supplied to the hydraulic cylinder.

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