JPH0132500Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a draft hitch device used in a draft control device.

(b) Prior Art Techniques related to draft control devices used for towing disc plows, soil-repellent plows, etc. have been known for some time.

For example, Utility Model Publication No. 166408, Utility Model Publication No. 47-
This technique is similar to the techniques described in Japanese Patent Publication No. 26324, Japanese Patent Publication No. 35605/1983, and Japanese Patent Application Laid-open No. 68804/1983.

(c) Problems to be solved by the invention However, in the above-mentioned conventional technology, only the hole for the draft hitch, on which the tip of the top link is pivotally supported during draft control, is drilled, so a disk plow or a When a soil-repellent plow is not used, the top link of a rotary tiller that performs position control must also be connected.

However, when a rotary tiller is attached, unless the top link is pivoted to a low position, the rotary tiller cannot be raised higher by rotation of the lift arm.

Therefore, it is inconvenient to use only the draft control hole of the draft hitch when a rotary tiller is installed.

In the present invention, the draft hitch is made to protrude downward from the fulcrum shaft part, and the draft hitch 29
A rotary hit pin hole 2 for a rotary tiller is provided below the rotary tiller.

(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 base 8 is attached to the rear surface of the hydraulic case 2, and a fulcrum shaft 35 is protruded from the lower end of the base 85.
Draft hitch pin holes 29a and 29b are opened above the fulcrum shaft 35 of the draft hitch 29, and a rotary hitch pin hole 2 is opened below the fulcrum shaft 35.
9c is opened, a spring receiver 86 of a balance spring 17 and a guide shaft 20 are pivotally supported at the upper end of the draft hitch 29, and the balance spring 17 is interposed between the hydraulic case 2 and the spring receiver 86.

(E) Embodiment The purpose of the present invention is as described above, and the structure of the embodiment shown in the attached drawings will be explained.

Figure 1 is a left side view of the hydraulic control device, Figure 2 is a side sectional view, Figure 3 is a top view, Figure 4 is a right side view, Figure 5 is a bottom view, and Figure 6 is a bottom view.
The figure is a rear sectional view.

Explain the movement of hydraulic equipment along the flow of pressure oil.

A hydraulic pump fixed to the tractor engine converts the lubricating oil in the transmission case into hydraulic oil.
The oil is sent by piping to a hydraulic port 16 on the top surface of the hydraulic case 2 shown in FIG.

An external pressure oil outlet is provided on the side surface of the hydraulic case 2 where the pressure oil port 16 is located, and an external pressure oil outlet is provided in this part, and an attached case is integrated with the external outlet switching valve 4, the flow rate control throttle valve 30, the throttle valve release valve 5, etc. 1 is attached. You can take out the pressure oil by piping directly from the external pressure oil outlet with this attached case 1 removed, or you can attach the attached case 1 as shown in Figure 3 and connect the various valves inside the attached case 1. External pressure oil can also be taken out through the pipe.

4 is the tip of the rotary valve of the external extraction switching valve, and an arm is attached to this to operate it.
30 is the tip of a rotary valve constituting a flow rate control throttle valve, and a lever is provided on this to operate it under the seat. Reference numeral 5 denotes the tip of a spool of a throttle release valve, and an arm 9 is fixedly attached to a sliding tube 8 and slides on a sliding shaft 7.

As shown in FIG. 4, a pivot pin 11 is provided on the arm 9, and a link 12 penetrates into the pivot pin 11.

When the tractor reaches the edge of the field and turns around, if the hydraulic pressure is restricted through the throttle valve, the work equipment will rise too slowly and the turning operation will be slow. Position control lever 1
5 is operated, the throttle valve release valve 5 is moved by the contact between the pin 14 and the end of the elongated hole 12a of the link 12 to release the throttle.

The pressure oil returned from the external pressure oil outlet is transferred to the hydraulic control valve 4.
7 and is controlled by the spool 48 and reaches the cylinder head 3.

Check valve 46 in cylinder head 3
Then, the pressure oil enters the hydraulic cylinder 2a through the slow return stop valve 45 and pushes the piston 41. The piston 41 pushes the arm 44 from the connecting rod 42 and rotates the lift arm 18 from the lifting shaft 43.

Reference numeral 31 in FIG. 1 is a safety valve for use when abnormally high pressure occurs within the hydraulic cylinder 2a. In such a flow of pressure oil, the hydraulic control valve 4
There are draft control, depth control, and position control mechanisms for moving the spool of the 7.

Draft control detects the traction load applied to the work equipment by the movement of the top link and moves the lift arm up and down, while depth control uses a sensor rod to sense the relative position of the rear cover and tiller claw and moves the lift arm up and down. Position control is a control method that causes the lift arm to converge at the position set by the operator using a lever.

If the position control lever is rotated to the maximum raised position while the draft control is being controlled by the depth control, the position control will take priority over other controls.
The work equipment is configured in a preferential structure so that it can be raised to its full height.

The position of the position control is set using the position control lever 15, and the control amount for draft control and depth control is adjusted using the draft/depth control lever 13.

Starting with position control, in the case of position control, the draft/depth control lever 13 is rotated forward to the lower limit position and fixed in FIG. 4 so as not to be involved in the control.

By doing this, in Figures 6 and 5,
The horizontal pin 67 of the arm 65 is released backwards from the boss portion 13a/cylindrical shaft 61 at the base of the draft/depth control lever 13 via the arm 62 and the link 58, so that it no longer engages with the vertical pin 68. be.

Also, the depth control wire is not connected to link 24 for the feedback link.
Also, since the draft hitch is also locked, the link 24 is pulled by the spring 80, and as shown in FIG.
The cylinder shaft 81 and arm 75 in FIG. 6 are rotated rearward, and the horizontal pin 74 is rotated fully in a direction in which it does not engage with the vertical pin 73.

Draft control users can also use Draft Hittsuchi 2.
9 is rotated fully backward by the draft lock body 33, the link 25 is pulled by the spring in the release direction by the link 27 and arm 26.

As described above, the draft control and depth control systems are located at positions where they do not engage with the vertical pins 68, 73 of the control bar 52, so they can be operated only with the position control bar 53.

In this state, position control lever 1
5 in the upward direction, the boss portion 15 in FIG.
The horizontal pin 69 is rotated forward via the shaft 59, arm 63, and link 60 from a, and the vertical pin 70 vertically installed on the position control bar 53 is moved forward, and the position control bar 53 is rotated forward. horizontally around the vertical pin 71 at the other end, and the push rod 5 is moved from the connecting plate 5 by the shaft 56.
4 to move the spool 48 up.

The sliding tube 50 of the shaft 56 is fixed to a mounting plate 57, and when the sliding plate 55 slides on the lower surface of the mounting plate 57, the connecting plate 51 slides together with the shaft 56 and control bars 52, 53. .

As the spool 48 moves upward, pressure oil enters the hydraulic cylinder 2a, the piston 11 is pushed, and the lift arm 18 rotates upward. This upward rotation of the lift arm 18 causes the arm 76 and the horizontal pin 72 to rotate backward from the arm 22 via the shaft 17 through the link 21, and the position control bar 53 is moved to the vertical pin 69 at the opposite end. The connecting plate 51 and push rod 54 are lowered by the spring 49, and the spool protrudes to a neutral position.

Therefore, the rotation angle of the lift arm 18 is determined in proportion to the magnitude of the rotation angle of the position control lever 15.

However, it is necessary to adjust the link mechanism of the position control so that the piston 11 does not push beyond the rotation limit of the lift arm 18 and break it. Adjust the lock nuts 83, 83 so that the hydraulic control valve becomes neutral when the lift arm 18 reaches 2 to 3 cm before the rotation limit.

The above is the case of position control.

In the case of draft control, place the position control lever near the lowest position,
The horizontal pin 66 in FIG. 5 is moved back so that it does not engage the vertical pin 70 of the control bar 53. During draft control, the top link from the work machine is connected to the fulcrum shaft 3 of the draft hitch 29.
Draft hitch pin holes 29a, 29b above 5
connected to.

The draft hitch 29 is supported by a pivot shaft 35 fitted into a protrusion at the lower end of a base 85 fixed to the rear surface of the hydraulic case 2 with bolts.

The base 85 should protrude as far as possible below the lower surface of the hydraulic case 2 to provide a span for the draft hitch 29, and the work equipment other than the draft control and the top link should be pivotally connected as low as possible, so rotary tilling is required. A rotary hit portion 29R for a working machine such as a device is provided so that a rotary hit pin hole 29c can be formed.

to the draft hitch 29 via the pivot pin 38,
A draft lock lever 32 is installed.

The draft lock lever 32 has a fulcrum crossing spring 37
is inserted, and at the position 32, the draft lock body 33 is urged to bite deeper, and
In the state 2', it is biased in the direction of being stabilized at the position 33'. The draft lock body 33 is wedge-shaped so as to fit between the base 85 and the stopper plate 34.

Further, the shaft 36 and the hole 33a are fitted with a gap to provide a margin for smooth insertion.

A draft hitch balance spring 17 is provided at the upper center as shown in FIG. The guide shaft 20 is fixed to the spring receiver 86. A balance spring 17 is fitted onto the guide shaft 20 and received by the other spring receiver 19. The spring pressure can be adjusted with a lock nut 40.

When the draft hitch 29 is pushed due to a change in the traction force applied to the working machine, the arm 26 rotates around the shaft 87 via the shaft 28 and link 27 while being balanced by the balance spring 17. As a result, the link 25 is pulled, and the pin 23a engaged with the end of the elongated hole 25a moves the arm 76 and the horizontal pin 72 forward from the arms 23 and 24 via the cylindrical shaft 81, thereby controlling the arm 76 and the horizontal pin 72. The bar 52 moves the spool 48 in the upward direction.

On the other hand, when no tractive force is applied to the draft hitch 29, the control bar 52 retreats to the neutral or downward direction. control bar 52
Since the vertical pin 68 at the other end engages with and is fixed to the horizontal pin 67, the draft/depth control bar 13 rotates around this.
By moving the position of this horizontal pin 67, the reference position for raising and lowering the traction force can be changed.

In the case of depth control, a depth control wire is connected to the feedback link 24, and as the plowing depth increases, the link 24 rotates upward. This is the same as when the traction force becomes large in the case of draft control, and the movement of the link after this is the same.

(F) Effects of the invention As constructed as described above, the invention provides the following effects.

First, the lower side of the draft hitch 29 is extended from the fulcrum shaft 35 to provide a special rotary hit portion 29R for rotary tilling work, and a rotary hit pin hole 39c is provided in the rotary hit portion 29R. Draft hitch pin hole 29
Since a and 29b are located at a high position, when the rotary tiller is towed as a working machine, the pivot point of the top link is too high, making it difficult to lift the rear end of the rotary tiller sufficiently when rising. We were able to avoid the problem of not being able to do so.

Second, in the case of work equipment that requires a large traction force, such as a disc plow or soil-repellent plate plow that requires draft control, the top draft hitch pin holes 29a and 29b are used to pivot the top link. However, in the case of a working machine such as a rotary tiller that requires a small traction force and needs to rise significantly when ascending, the rotary hit pin hole 29c is used.
Therefore, it is possible to use the hit hole of the draft hitch 29 depending on the working machine and work in the optimum condition.

[Brief explanation of the drawing]

Fig. 1 is a left side view of the work machine control device, Fig. 2 is a side sectional view, Fig. 3 is a plan view, and Fig. 4 is a left side view of the work equipment control device.
The figures are a right side view, FIG. 5 is a bottom view, and FIG. 6 is a rear sectional view. 2...Hydraulic case, 17...Balance spring, 2
9... Draft hit, 29a, 29b... Pin hole for draft control, 29c... Pin hole for rotary work, 29R... Rotary hit portion, 35... Pivot shaft, 85... Base.

Claims (1)

[Scope of utility model registration request] A base 85 is attached to the rear surface of the hydraulic case 2, and a fulcrum shaft 35 is protruded from the lower end of the base 85.
5 pivots the middle part of draft hitch 29,
Draft hitch pin holes 29a and 29b are opened above the fulcrum shaft 35 of the draft hitch 29,
A rotary hit pin hole 29c is opened below the fulcrum shaft 35, and a spring receiver 86 of the balance spring 17 and the guide shaft 20 are pivotally supported at the upper end of the draft hitch 29. A work machine control device for an agricultural tractor, characterized in that a balance spring 17 is interposed.