JPS5853881B2 - Tractor control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type of tractor equipped with a power lifting tool hitch linkage, and more particularly to a control device for a tractor.

Most wheel tractors, especially for agricultural use, utilize a powered three-point pitch that can be raised and lowered to couple the tractor and implements carried behind the tractor.

Typically, a draft sensing means is provided to measure the draft load between the implement and the tractor, and the draft sensing means acts through a control system to raise and lower the hitch and implement to maintain a constant draft load.

In addition to measuring draft forces, it has also become common to utilize the vertical position of the implement as a control factor.

This position control is performed independently of draft control or works simultaneously with it.

To prevent mounted equipment, such as plows, from going too deep into the ground when initially lowering the equipment or during other operating conditions, it is desirable to establish a maximum depth to which the equipment can be lowered during operation.

It is also desirable that the driver be able to change this maximum depth at will.

When the hitch reaches a predetermined height or equipment transfer position,
It would also be desirable to automatically stop pitch rise and unload the hydraulic system to reduce power losses and overheating of the working fluid caused by constant pumping.

The implementation and adjustment of such a control system should be simple, and the components and adjustment equipment should be easily accessible.

It is therefore an object of the present invention to provide a control system for a hydraulically operated hitch on a tractor which is separable into two parts for servicing the components and which The parts maintain an operative position when separated and are easily placed into operative relationship during assembly.

Another object of the invention is to provide a fluid control valve that is easily accessible without disassembling the control system.

Still another object of the present invention is to provide a pitch position detection member that reliably acts on a fluid control valve to reliably stop the pitch increase when a tractor hit reaches a predetermined height.

Yet another object of the invention is to provide a control system for limiting the depth of a tractor towing implement by correlating a means for sensing the position of the implement with a means for limiting the maximum depth of the implement.

These and other objects and advantages will become apparent from the following description and accompanying drawings.

FIG. 1 shows a tractor 1 connected to an implement 3 by a three-point pitch.

The hitch includes a pair of lower links 5 (only one of which is shown) and an upper link 7.

Links 5 and 7 constitute a normal three-point pitch.

The lower link 5 is lifted by a lift link 9 connected to a lift arm 11 fixed to a lock shaft 16.

As will be described later, the lock shaft 16 ensures that the three-point pitch lower link 5 moves up and down, and also functions to indicate the position of the three-point pitch lower link 5 with respect to the tractor. Forms part of the position sensing mechanism.

The arm 11 has a piston 14 operating within the cylinder 13.
lifted by a hydraulic unit with

The control system is mounted within the tractor housing, which consists of a base part 15 and a cover 17.

The base portion 15 has a large rear opening 19 which extends over the entire width of the base and provides practical access.

The cover 17 is held on the base by fastening means such as bolts 20 threaded into the base.

The direction is such that it faces forward in the traveling direction of the tractor.

Controls hydraulic means 13, 14.

The control device for raising and lowering the pitch is therefore diagrammatically shown in FIG.

A fluid control valve 1 is provided and has an inlet 42 connected to a suitable pressure source, an outlet 44 connected to the hydraulic cylinder 13, and a discharge or relief 46.

The details of valve V are not relevant to this invention; valve V may be of any conventional type and is actuated by a plunge shaft 41 that engages a bell crank 43 that is pivotally connected to a fixed shaft 45. are doing.

The spring 56 pushes the shaft 41 to the right and raises the pitch.

When the plunger shaft 41 moves to the left, the hitch...
Descend.

One arm of the bell crank 43 is connected to a link 47 by a ball joint, and the link 47 itself is
At the other end, it is connected by a ball joint to a second bell crank 49 which is pivotally connected to the fixed shaft 51.

When the bell crank 49 rotates around the shaft 51, the bell crank 43 rotates around the shaft 45 accordingly.

Bell crank 49 is connected to roll rod 53.

The fork-like arm 57 acts against the spring 55, and the spring 55 causes the control rod 53 to
Enlarged portion 53 of control rod 53 surrounding 32
It is supported by a.

The crank 49 has an adjustment bolt 54, and its curved surface 54a
is engaged with the flattened end surface 53b of the enlarged portion 53a.

The spring 56 on the plunger shaft 41 presses these surfaces together, and since they are only in contact, the bell crank 49 can be moved without uncoupling.
and the control rod 53 can be separated.

Here, the bell crank 43 link 47 and the second bell crank 49 constitute a third linkage that is connected to the control rod 53 and controls opening and closing of the valve by the movement of the rod 53 when the cover 17 is added to the housing. be done.

Arm 57 forms part of a tubular shaft 64 that is rotatably mounted on shaft 60 .

This shaft is fixed within the legs of the U-shaped member 67.

As seen in FIGS. 2 and 3, when the shaft rotates clockwise about the axis 66, the spring 55 is rotated in a clockwise direction.
Press 3 backward.

The fork-shaped arm 57 has a bub 58, and the bub 58 has a
When pressing the spring 55 to push the rod 53 backward and move the rod 53 forward, the fixed flange 81
supported by.

The member 67 is supported at its legs by a shirt 61.62 having a common axis 59.

These shafts extend through the side walls of the housing on the tractor.

The other end of the shaft 61 is a link 63 fixed non-rotatably.
has.

Link 63 is pivoted to a driver-set draft manual link 65.

Link 65 is connected to a quadrant lever (not shown).

The position of the box-shaped arm 57 is the shaft 60, 6.
4Lf) @66 position.

In FIG. 4, member 67 is in an intermediate position and the shirt l
The -60,64 axes are at point a.

By moving the link 65 and rotating the shaft 61, the shaft 60°64 can be pivoted to point or point C.

In addition to the actual movement of shaft 60.64, shaft 6
4 can be rotated about an axis 66 by an arm 69 fixed thereto.

Arm 69 is connected to link 73 by pin 71.

Pin 71 extends through a slot 75 in link 73.

The link 73 is connected to the plunger 37 by a pin 77, and the plunger 37 is connected to the large diameter portion 4 on the plunger 37.
It is pushed downward by a spring 39 supported by 0.

The draft input plunger 37 is coupled to a draft sensing device (not shown), which may be of any suitable form, for measuring the draft force on the hit.

This measures the force exerted on one or both of the upper link 7 or the lower link 5.

The plunger 37 moves downward when the draft load increases.

Control rod 53 has an extension 79 connected to floating lever 83.

The upper part of the floating lever 83 is pivotally connected to a position sensing link 85, which in turn is pivotally connected to a flange member 87 attached to the lock shaft 16.

The movement of the lock shaft 16 during the raising and lowering of the hit is controlled by the flange member 87. It is transmitted to the floating lever 83 via the link 85.

The lower end of lever 83 is pivotally connected to a link 89 having a slot 91 adapted to receive a pin 93 carried by the lower end of link 95 fixed to shaft 97.

The shaft 97 carries a link 99 fixed at its other end, which can be rotated by a second operator-set maximum depth manual link 101 .

Link 101 is operated by a quadrant lever (not shown) suitably positioned for operation by the tractor operator.

Lever 83 and its control rod 53, link 10
1 and the link 85 have a function as position limiting means.

Slot 91 is shown in its extreme position in FIG.

As the tool descends further, lever 85 moves forward.

This activates valve ① to raise the tool.

The lever 83 rotates counterclockwise to move the rod 53 forward.

Bell crank 43 moves shaft 41 to the right and limits the lowering of the implement.

Flange member 8 carried by lock shaft 16
7 carries a pin 109 which acts to engage the bellcrank member 107.

The member 107 acts on the second bell crank 103 via an adjusting screw 105, the bell crank 103 is connected to a bell crank lever 49 by a link 104, and the lever 49 acts via the link 47 to open the valve Press in one direction.

An elastic member (not shown) connects the bell crank 107 to the bolt 1.
It is held against 05.

Here, the links 63 and 65, the shafts 60 and 61, the member 67, the arm 57, and the pin 58 constitute a first linkage that moves the control rod 53 in response to an operation command from the driver.

Further, the plunger 37, pin 71, arm 69, shaft 64, arm 57, and pin 58 constitute a second linkage that moves the control rod 53 in response to the draft force signal.

The control system is separated into two parts.

One part A includes a control rod 53 and a link 65.
．． 85, 101, a member 67, a plunger 37, and links and levers connected thereto.
5 is installed and supported.

This is best illustrated in FIG.

Other parts B are valve v, hellcrank 43, 49, 1
07 and is attached to the cover 17.

The first portion A is mounted within the base portion 15.

Shaft 61.97 is rotatably mounted within base portion 15, links 63, 65, 101 are external to the housing, control rod 53, shaft 60, member 67
, arm 69, link 89, and plunger 37 are inside the housing.

The second part B is attached to the cover 17 and generally includes a valve ■
, bell crank 43, 49, 103.

It consists of 109.

Fixed shaft 4 rotatably supports bell crank 43
5 is attached to the rear wall.

The bell crank 43 engages a plunger shaft 41 that extends parallel to the rear wall.

The shafts 51, 108 are mounted on the end walls of the cover.

The shaft 51 rotatably supports the bell crank 49,
Shaft 108 rotatably supports bell cranks 103, 107.

The control rod 53 extends fore and aft 11 and has a rearward facing surface 53b that engages the forward facing curved surface 54a of the bolt 54, as described above.

These surfaces, the bell crank member 107, and the pin 109 are 2
The parts are interconnected and can be separated without disrupting the operational relationship of the two parts.

The two components are separated while maintaining their positional relationship in the operating state prior to separation.

In the neutral condition, the spring 56 is compressed and forces the spool into the raised position, while the control linkage prevents such movement.

The spring 56, the end of the bell crank 43.490, the bell crank 107, and the pin 109 are 2
forming coupling means between the parts.

The control rod 53 and bolt 54 can be engaged and disengaged without untying any of the coupling means.

Bell crank 107 and pin 109 can be separated with a corresponding simple movement.

The operation of the control linkage is as follows.

Assuming the tool is in the raised position and the operator desires to lower it, the operator operates the quadrant lever to control the draft setting.

To lower the implement, the link 65, as seen in the drawing,
It is moved forward, causing the shaft 61 to rotate counterclockwise, thus causing the U-shaped member 67 to rotate counterclockwise about its axis 59.

As a result, the shaft 60 carried by the member 67 moves rearward from position a to position a, and at the same time the control rod 53 is pushed rearward via the spring 55.

This movement is transmitted via bellcrank 49, link 47 and bellcrank 43 to plunger shaft 41, forcing the valve against its spring into a position that lowers the tool.

When the implement enters the ground, a draft force acts on the pitch, which draft force is measured with a suitable measuring device and causes a downward movement of the draft input plunger 37 as seen in the drawing.

This downward movement is caused by link 73, pin 71 . and a lever 69 to rotate the shaft 62 counterclockwise, and a spring 55 to act on the control rod 53 to rotate the shaft 62 counterclockwise.
This acts to release the force applied to the valve V and gradually closes the valve V.

When the lowering of the tool into the ground increases the draft force to a point predetermined by the setting of link 65, plunger 37 has moved sufficiently downward to reach a neutral position where no oil flows into or out of the cylinder. corresponds to

The arm 57 is returned to point a shown in FIG.

Prior to lowering the implement, the operator has pre-adjusted link 101 to a position corresponding to the maximum depth at which operation of the implement is desired.

This acts through link 99, pin 93 and link 89 to position lower pin 90 of floating lever 83.

As the implement is lowered, lock shaft 16 rotates clockwise, as viewed in the drawings, moving lever 85 forward.

Via the intermediate pin 92, the extension 79 of the control rod 63 is moved rearwardly and when the maximum depth selected by the operator is reached, the valve is in a neutral position where no oil enters or exits the cylinder. It turns out.

Thus, it can be seen that both the draft force on the pitch and the position of the pitch affect valve operation.

The position control simply serves as a limit to the depth, while the draft control serves to maintain the depth of the equipment at the set depth.

In effect, the position control acts as a four-way stop via the pin 93 to limit rearward movement of the control rod 53, moving the control rod to its neutral valve position when the predetermined depth is reached.

As the draft force changes during tool operation, plunger 37 moves up and down, thereby causing lever 69 to rotate shaft 64 and actuate control rod 53.

Controlling the opening and closing of the valves to raise and lower the implement to maintain a constant draft force is thus predetermined by the setting of the lever 65.

The valve is returned to the neutral position before the position set by the link 101 reaches a depth at which the draft force acting through the plunger 37 is sufficient to move the valve to the neutral position. In some cases, rod 53
moves rearward and away from the floating lever 83, and the spring 55 is compressed.

If the operator wishes to lift the implement from the ground, he operates lever 65 rearward to rotate shaft 61 clockwise, thereby moving fork-like arm 57 forward. As a result, the control rod 53 moves forward, and the bell crank 49,
Via lever 47 and bell crank 43, the valve is moved to its raised position, allowing oil to flow into the cylinder and lift the implement.

As the tool is lifted, the lock shaft 1
6 rotates counterclockwise and when the highest transfer position is reached, the pin 109 engages the arm of the bell crank 107.

This action is achieved via the adjusting screw 105 on the bell crank 1.
03 clockwise and lift the lever 104,
The bell crank 43 moves the plunger shaft 41 to its neutral position, reducing the flow to the cylinder and thus
Raising the tool is stopped.

A hydraulic fitting (not shown) for valve V is mounted on cover 17.

The bolts 54, 105 can be adjusted using a tool through openings in the rear wall of the cover 17.

The openings are closed with threaded plugs 110,112.

Slot 91 in link 89 allows the position control linkage to operate during normal operation.

That is, the link 85 moves back and forth and the floating lever 83
is rotated about the pin 92, and the link 89 moves back and forth together with the pin 93 in the slot 91.

Rightward movement of link 89 is limited by the position of pin 93 set by lever 101, but leftward movement of the link is not.

Slot 75 in link 73 performs a similar function, allowing link 69 to move upwardly with pin 71 moving within slot 75.

As can be seen from the foregoing, the present invention provides a control linkage for a tractor that allows the driver to set any desired draft force without interference from position control.

At the same time, the operator can set the maximum depth at which the implement will operate.

This is particularly important to ensure that the equipment does not go too deep into the ground when it first enters the ground.
In this case, the front, like the bottom of a plow, does not itself provide enough draft force for the mechanism to stop the descent of the implement;
Continued entry of the rear part of the implement does not affect the draft response member as the implement reaches its proper depth.

By being able to set the floor or maximum depth that the equipment will enter, the operator can ensure that the equipment does not go too deep into the ground.

Further, this control system is uniquely equipped and housed.

The housing for the control system is located on the cover 1 of the housing.
It has a rear opening completely covered by 7.

The opening 19 allows sufficient access to the interior of the base portion 15.

Since the valve ■ is attached to the cover, the valve can be easily accessed and adjusted, repaired, or replaced.

This can be done without disturbing any parts of the control system.

Embodiment 1 The control device has a driver-set draft input means, interconnects the draft detection device, the draft input member, and the valve actuation means, and the draft force applied to the three-point pitch is set by the driver-set draft input means. the control device includes second operator-set maximum depth position input means, the controller being adapted to adjust the valve to maintain the pitch up or down to establish and maintain said set point; the position sensing device is responsive to the vertical position of the pitch, and the position control device interconnects the second driver setting device, the position sensing device and the valve actuation means, the position sensing device being responsive to the vertical position of the pitch, and the position control device interconnecting the second driver setting device, the position sensing device and the valve actuation means, the position sensing device being responsive to the vertical position of the pitch; 5. A tractor control system as claimed in claim 1, wherein the valve actuation means adjusts the valve to prevent the implement from lowering below a predetermined level.

Embodiment 2 Valve actuation means includes a reciprocating control rod operatively connected to the valve, a first member rotatable about a first fixed axis by said first operator-set draft input means; a second member operatively connected to and rotatably carried by the fixed shaft on a second shaft spaced apart from the first fixed shaft, the draft sensing device being operatively connected to the second member; and rotate it around a second axis.

The tractor control device according to embodiment 1, further characterized in that.

Embodiment 3 A position control device includes a floating lever rotatably coupled to a control rod in a first position and a position sensing device rotatably coupled to the floating lever in a second position; The second operator-set maximum depth device is operatively connected to the floating lever in a third position.

The tractor control device according to embodiment 2, further characterized in that.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a tractor, hitch, and implement to which the present invention is applicable. FIG. 2 is a cross-sectional view of the tractor and linkage, showing the control linkage that operates the hydraulic control valve to control the hitch. FIG. 3 is a perspective view of the linkage interconnecting the draft sensing unit, driver controls, position sensing unit and control valve. FIG. 4 is an enlarged view showing details of the control linkage. FIG. 5 is another enlarged view showing additional details of the control linkage. FIG. 6 is a cross-sectional view of the control linkage viewed from the top. FIG. 7 is a sectional view taken along line 7-7 in FIG. 6. FIG. 8 is a sectional view taken along line 8-8 in FIG. 6. 1...Tractor, 3...Tools, 5.-
・-Hitsuchi Link, 7...Hitsuchi Link, 9・
...Lift link, 11...Lift arm, 13...Cylinder, 14...Piston, 16...Lock shaft, 15...・
...Base part, 17...Cover 20...
・Bolt, ■...Fluid control valve, 37...
...Draft input plunger, 53...Control rod, 54...Bolt, 54a.
...Curved surface of bolt 54, 67...U-shaped member, 83...Floating lever, 65...
Driver setting draft human power link, 101... Driver setting maximum depth human power link.

Claims (1)

[Claims] 1 A housing of a tractor, a first linkage that is provided in the housing and that responds to a driver's operation command, a second linkage that responds to a draft signal, and either the first linkage or the second linkage A control rod to be moved, a fluid control valve for controlling pressure fluid to a hydraulic device for raising a three-point hitch of a tractor, a lift link connected to a lower link of the three-point hitch, and a lift link coupled to the lift link. a lift arm that moves up and down, the lift arm being coupled to the lift arm and engaging the control rod, ensuring the up and down movement of the lower link of the three-point hitch and indicating the position of the lower link relative to the tractor; It consists of a lock shaft that forms part of the hit position sensing mechanism together with the arm, an opening/closing cover is removably attached to the housing, the control rod and the lock shaft are supported by the housing, and the fluid is connected to the cover. Install the control valve,
Furthermore, when the cover is added to the housing, a third linkage is provided on the cover, which is coupled to the control rod and operates the fluid control valve by the movement of the rod.