JPH0344722B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a hydraulic control device for lifting and lowering a working machine of an agricultural tractor.

(b) Prior art A technique of arranging a position control and a draft control device side by side and operating a spool using the position control bar and the draft control bar is known in the art as disclosed in Japanese Utility Model Application Publication No. 55-30527. ing.

In the above technology, by placing the position control lever in the highest position, the draft control bar preferentially operates the spool in the lifting area of the work equipment during work, and the position control bar operates the draft A technique is disclosed in which the control bar is placed a certain distance away from the spool position.

(C) Problem to be solved by the invention As described above, when the position control and draft control are placed side by side, the draft control bar preferentially controls the spool when the position control lever is in the highest or lowest position. Operation is absolutely necessary, and a mechanism equipped with two control mechanisms side by side is always configured in this way.

In addition to this technology, the present invention has the following feature: When a tractor turns around at the edge of a field, it is necessary to raise the work equipment to the highest position, and for this purpose, it is necessary to set the depth control lever at which position. Even if the position control lever is turned to the highest position,
The position control bar always acts on the spool preferentially over the depth control bar, making it possible to raise the work equipment to the highest position.

In addition, with this configuration, when the position control lever is lowered to the lowest position after turning at the edge of the field, the original depth control bar immediately returns to the state where it preferentially operates the spool, and the depth control lever Since the position has not moved from the state before turning, the structure is such that the plowing operation can be continued at the same plowing depth as in the previous step.

In the present invention, in order to give priority to position control over depth control, when the position control lever is raised to the highest position, the distance between the control bar for position control and the control bar for depth control from the spool contact position is The configuration is such that when the position control bar is at its closest position, the position control bar moves further forward to ensure a gap a between it and the depth control control bar.

This state is the position of both control bars shown in Figure 14, with the position control lever in the highest position, the lift arm in the highest position, and the depth control lever in the shallowest position, with the depth feedback This is the position when the link is at its shallowest position.

In order to easily create this condition and make adjustment easier, we provide a stopper that determines the shallowest position of the depth feed back link, restricts the movement width, and also defines the deepest position, so that the control bar does not over-rotate. The width of rotation of the depth feedback link is regulated using elongated holes and pins.

Also, since it is difficult to create the shallowest position of the depth feed back link when adjusting it by one person, removing the depth control wire will force the depth feed back arm and link to be fixed at the shallowest position. It is equipped with a spring.

With the above configuration, when the position control and the depth control are placed side by side, the link relationship between both control devices can be adjusted in sequence, and the work equipment can be controlled without losing the control balance. It was possible to make it into a device.

(d) Means for Solving the Problems The objects of the present invention are as described above, and the configuration for achieving the objects will now be explained.

The rotation of the position control lever rotates one end of the position control bar, the vertical movement of the lift arm rotates the other end of the position control bar in a feedback manner, and the rotation of the depth control lever rotates one end of the position control bar. The configuration is such that one end of the depth control bar is rotated, and the other end of the depth control bar is rotated in a feedback manner by the back and forth movement of the depth feedback link, and the position control bar and the depth control bar are moved in the middle of the position control bar and the depth control bar in the pushing direction. In a configuration in which the tip of the spool is slid to switch to "raise" operation, the position control lever is set to the highest position and the depth control lever is When the depth control bar is at its shallowest position and the depth feed back link is at its shallowest position, move the depth control bar backwards by a fixed distance a from "neutral" to "lower" direction on the extension line of the spool's sliding direction. It is designed to be located in the same position.

Further, a regulating portion for regulating the rotation width of the depth feedback link is provided to regulate the rotation width of the depth control bar on the feedback link side.

Further, a spring is inserted in the depth feedback system so that the depth feedback link is always biased toward the shallowest direction.

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

Fig. 1 is a plan view of the hydraulic control device showing the first embodiment, Fig. 2 is a side view, Fig. 3 is a side sectional view, Fig. 4 is a rear sectional view, and Fig. 5 is a bottom view. It is a diagram.

A hydraulic case 1 is placed on the upper surface of a transmission case or a rear axle case of an agricultural tractor, and a hydraulic cylinder 1a is provided inside the hydraulic case 1 to allow a piston 15 to slide.

The sliding movement of the piston 15 is transmitted to the lift arms by a connecting rod, an arm, and a lifting shaft to move the lift arms 5L and 5R up and down.

A cylinder head 2 is provided at the head of the hydraulic cylinder 1a at the front of the hydraulic case 1, and a slow return stop valve 3 is installed in the cylinder head 2.
A and a check valve 3b for slow return are provided.

Further, as shown in FIG. 5, a safety valve 3c is also provided in the hydraulic case in case an abnormal hydraulic pressure occurs in the hydraulic cylinder 1a. 3 is the knob handle of the slow return stop valve. Further, a top link bracket 14 is fixed to the rear surface of the hydraulic case 1.

Pressure oil is projected from a hydraulic pump attached to the engine of the agricultural tractor and enters the pressure oil port 1b on the top surface of the hydraulic case 1 through piping. From here, it can also be taken out to the external hydraulic outlet,
When the lid body 4 is attached as shown in FIG. 1, the oil is sent to the hydraulic control valve 16 as it is.

Pressure oil that has been switched between "raise", "neutral" and "lower" by the spool 17 of the hydraulic control valve 16 enters the hydraulic cylinder 1a via the check valve 3b of the cylinder head 2 and the slow return stop valve 3a.

A spring 18 is interposed in the spool 17 of the hydraulic control valve 16, and is always biased in the projecting direction, that is, in the "downward" direction. A push rod 19 is in contact with the tip of the spool 17, and a connecting plate 22 is fixed to the rear end of the push rod 19. A sliding plate 26, a position control bar 23 for position control, a depth control bar 24 for depth control, etc. are fixed to the connecting plate 22. The push rod 19 slides inside the sliding tube 20.

Furthermore, the sliding plate 26 is capable of sliding on the mounting plate 21. The sliding tube 20 is fixed to a mounting plate 21 by welding. Furthermore, a stopper 21a for the control bars 23, 24 is provided at one end of the mounting plate 21. Conventional stoppers were installed at the pivot points on the position control lever and draft control lever sides that move the control levers of the control bars 23 and 24, but in this configuration, they directly prevent the control bars from moving. Therefore, it was provided on the lower side of the hydraulic case 1.

Since the spool 17 is moved back and forth by the movement of the control bar, when adjusting the movement of the control bar, the control lever, and the feedback link, first, the position of the control bar is adjusted relative to the fixed position of the position control lever. It is necessary to fix it. The stopper is used for this purpose.

That is, when the position control lever 28 reaches the highest position, the vertical pin 36 of the control bar 23 hits the rear end of the stopper 21a and does not rotate any further.

Further, when the depth control lever is at the highest position, the vertical pin 35 of the control bar 24 for depth control hits the rear end of the stopper 21a at the 35' position and does not rotate any further.

If this stopper were not present, the control bars 23 and 24 would come out in the direction of pushing the spool further, and the "raised" state would continue forever.
This will destroy the lift arm and lifting shaft.

In addition, since it is not installed on the outside of the hydraulic case as in the past, only a small rotating stopper is required, and since the vertical pin of the control bar is stopped by directly contacting it, there is no error, and it is possible to avoid small gaps. This made it possible to provide certainty in areas where control imbalances occur due to differences.

Further, in this configuration, the control levers 27, 2
The part that transmits the operation on the 8 side to the control bars 24, 23 and the part that transmits the movement of the feedback link to the control bars 24, 23 are transmitted by engagement of a horizontal pin and a vertical pin, respectively.
Thereby, the hydraulic control valve 16 can be attached to the lower surface of the hydraulic case 1, and the control bars 23 and 24 can also be provided in close contact with the lower surface of the hydraulic case.

Since the vertical pin and the horizontal pin are engaged, there is always point contact between the two, and the control bar side,
No bending force is applied to the control bars 23, 24 due to the movement of the feedback link.
The control bar can always be rotated or slid horizontally.

The rotation of the position control lever 28 is transmitted from the boss portion 28a to the shaft 29 using a key, and from the arm 32 to the horizontal pin 34 implanted in the arm 32.
is transmitted to the vertical pin 36 of the control bar 23. As a result, when the spool is moved to the "up" position, the vertical pin 40 moves from the arm 6 of the lift arm 5 to the shaft 44 to the arm 42 via the feedback link 7 and the arm 8, and the horizontal pin 38 moves back. Backward control bar 23
A feedback signal is transmitted in the direction of returning the to the "neutral" position.

When the position control lever 28 is rotated in the downward direction, the horizontal pin 34 retreats, the spool 17 is pushed by the biasing spring 18, and the push rod 19,
The control bar 23 is pushed back by the connecting plate 22, and the vertical pin 36 comes into close contact with the horizontal pin 34 and retreats.

In the case of depth control, from the depth control lever 27, the boss portion 27a, the cylinder shaft 30,
The operating force is transmitted to the arm 31, and the horizontal pin 33 moves the vertical pin 35 of the control bar 24 back and forth.

On the other hand, the depth feed back arm 1 in Fig. 2
The amount of rotation of the sensor rod or the rear cover that also serves as a sensor is transmitted through the depth control wire connected to the depth control wire 1, and transmitted to the arm 9, the cylinder shaft 43, and the arm 41 through the depth feed back link 10. The vertical pin 39 of the control bar 24 is moved back and forth by the horizontal pin 37 of the arm 41.

The depth feed back arm 11 is constantly pulled by a spring 12 so that the control bar is always in the most retracted position. The depth feedback arm 11 is configured to stop at a position where the stop pin 50 at the other end touches the pivot 48.

This stop pin 50 regulates the rotational rear end position and rotational front end position of the depth control bar 24.

Angle A between the positions of stop pins 50 and 50'
The depth feed back link 10 can be rotated only within the range, and the depth control bar 24 can be rotated excessively beyond that, overriding position control or destroying the lift arms. I try not to.

In this way, in the first embodiment, the rotation regulating section of the feedback link is configured to regulate the control width of the control device.

Fig. 6 is a plan view of the hydraulic system showing the second embodiment, Fig. 7 is a right side view, Fig. 8 is a left side sectional view, Fig. 9 is a front sectional view, and Fig. 10 is a cylinder head. Figure 11 is a side view of the hydraulic control valve, Figure 12 is a drawing of the control bar when position control is used and the depth control lever 27 is at the lower limit, Figure 13 is when depth control is used. A drawing of the control bar when the position control lever 28 is placed at the lower limit position, and FIG. 14 is a drawing showing the adjustment state of the position control and depth control.

Hydraulic pressure enters the pressure oil port 55 of the cylinder head 52 from a hydraulic pump energized by the engine.
As soon as the pressure oil port 55 is entered, the relief valve 54
In addition, pressure oil external outlets 96 and 95 are provided. Pressure oil passes through external outlets 96 and 95,
Piping leads to front loader or dozer equipment. In addition, a pressure oil external outlet 97 for taking out the pressure oil after being controlled by the hydraulic control valve is also provided on the side surface of the cylinder head 52.

The pressure oil that has passed through the pressure oil external outlet ports 96 and 95 is sent to the lid 51b of the hydraulic control valve chamber 51c. The lid body 5
1b is penetrated by an oil passage, and pressure oil is passed through this lid body 5.
Hydraulic control valve 56 fixedly installed on the inner surface of the lid from 1b
sent to.

Pressure oil controlled by the hydraulic control valve is sent back to the cylinder head 52 and enters the hydraulic cylinder 51a through the check valve 92 of the cylinder head 52 and the slow return stop valve 53. A check valve 92 is provided on a detour for "raising" in the case of slow return. Reference numeral 91 is a safety valve for use when abnormal pressure occurs within the hydraulic cylinder.

A piston 90 in the hydraulic cylinder 51a is pushed by pressure oil and pushes the connecting rod, and the arm 89 rotates the lifting shaft 88 to move the lift arm 59 up and down.

A top link bracket 60 is fixed to the rear surface of the hydraulic case 1 as a lid.

Further, on the lid body 51b of the aforementioned hydraulic control valve chamber 51c, a position control lever 73 and a depth control lever 72 are connected to a shaft 74 and a cylinder shaft 75.
It is supported by

The main part of the present invention relates to the link and arm that operate the spool of this hydraulic control valve 56.

When performing position control, the depth control lever 72 is fixed at the lower limit position,
Operator presses position control lever 7
3 is rotated back and forth, the arm 76 and pin 78 are rotated via the boss portion 73a and the cylindrical shaft 75, and the position control bar 80 is rotated back and forth. By rotating the position control lever 73 in the upward direction, the position control bar 80 is rotated in the upward direction of the spool, and the lift arm 59
goes up.

When the lift arm 59 is raised, the arm 68 rotates, and the arm 70 rotates via the feedback link 69. The position control bar 80 is rotated from the arm 70 in the "lower" direction by the cylindrical shaft 87, arm 85, and pin 83, and is placed in the "neutral" position.
Position control converges when the position is reached.

In the case of depth control, the position control lever 73 is set to the lower limit position, and when the depth control lever 72 is rotated in the upward direction, the boss portion 72a, shaft 74, arm 77, pin 7
9 causes the depth control bar 81 to "raise"
direction and raise the lift arm 51. At the same time, the rotary tiller is raised and the rear cover or sensor rod is lowered, and the depth control wire linked to the sensor rod is loosened, and the pin 62 and arm 61 to which the other end of the depth control wire is connected are rotated forward by the spring 64. As a result, the depth feed back link 66 is pulled by the arm 67, and the depth control bar 81 is rotated in the "down" direction by the arm 67, and stopped at the "neutral" position.

(F) Effect of the Invention As above, the first embodiment shown in FIGS. 1 to 5 and the second embodiment shown in FIGS. 6 to 14 have been roughly explained. The present invention relates to a configuration for giving priority to position control over draft control in a work machine control device having two operating systems, position control and depth control.

Even during depth control, when going around the edge of the field or when a danger occurs, it is necessary to raise the work equipment all at once to the top, and to do this, raise the position control lever as far as it will go. When the depth control lever reaches this position, the work equipment must rise as far as it can, no matter what position the depth control lever is in, and position control must take priority. Adjustments are required for this purpose.

Also, regarding the position control lever, if the lift arm rises all the way when the position control lever is moved to the highest position, and if more pressure oil is sent, the piston mechanism will break, so the safety valve must continue to spray. Therefore, it is necessary to make this adjustment so that the hydraulic control valve becomes "neutral" one step before the lift arm reaches its highest position.

For this purpose, when the position control lever is turned all the way, a rotation stopper is used to prevent it from rotating any further. is provided.

In addition, the rotation width of the rear cover, which is the sensor for depth control, is larger than the rotation width of the depth feed back arm, so if control is not performed so that only a certain range is controllable, excessive rotation of the rear cover will directly occur. This may be transmitted to the control bar via the feedback link, causing the control bar to over-rotate, giving depth control priority over position control, or causing the lift arm to over-rotate. There is.

In this case, restricting the width of rotation of the rear cover would make the role of the rear cover in the rotary tilling device indispensable, so it is necessary to restrict the width of rotation with the feedback link.

In the case of the first embodiment, this rotation width is regulated by the contact angle A between the pin 50 and the pivot body 48 in FIG. The long hole 63b and pin 6 of the regulation stopper 63, 63a shown in the figure
I'm going to 1b.

The regulation stopper 63 is configured in a "〓" shape, and its base is pivotally supported on the hydraulic case 51 by a pin 63c, and as the pin 61b rotates as the feedback arm 61 rotates, it is designed to follow the rotation. .

Reference numeral 64 denotes a spring that is pulled when the feedback arm 61 is in the direction in which the wire is loosened, and the strength of this spring is such that the depth control bar 81 can be rotated.

In the case of the first embodiment from Fig. 1 to Fig. 6,
Since both control bars are fixedly supported, it is difficult to understand, so the adjustment of the control link device will be explained based on FIGS. 12, 13, and 14.

First, let me explain the adjustment of the position feed back link. Fully open the stop valve and
As shown in Figure 2, set the position control lever to the highest position.

The upper end of the position control bar 80 rotates fully forward, and in the first embodiment, the pin 36 of the control bar 23 contacts the rotation stopper 21a in FIG.
In the figure, the rear edge of the control lever 73 comes into contact with the end 71a of the stopper 71. Adjust based on this position.

When the lift arm comes up, the lower end of the control bar 80 retreats and becomes "neutral", but the hydraulic control valve becomes neutral at a position where there is a play of 20 to 30 mm relative to the rotation limit of the lift arm. In the first embodiment, the lock nut 7a shown in FIG.
In this embodiment, the turnbuckle 69a shown in FIG. 7 is adjusted.

This determines the final stop position of the lift arm when the position control lever is at its highest position. At the same time, the final position of the control bar 80 is also determined.

Next, the depth control link is adjusted based on the adjusted state of the position control.

Depth control feedback arm 1
1 and 61, and the biasing springs 12 and 64 are used to position the feedback arms 11 and 61 at their shallowest rotation limits. In the first embodiment, the pin 50 is in contact with the rear part of the pivot body 48, and in the second embodiment, the pin 61b is located at the front end of the long hole 63b of the stopper. This state is used as the reference for depth control.

Next, move the position control lever to the lower limit position and the depth control lever to the upper limit position. The depth control bar and position control bar now look like those shown in FIG. 13.

Then, before the lift arm is raised and the position control bar is not activated, fully close the stop valve, and check whether it is in the ``raised'' position by the sound of the relief valve blowing.

Then, find the point where the relief valve no longer provides relief due to the relief valve's jetting state stopping, that is, the switching point to the "neutral" position, and lock nut 1 of the feedback link.
Adjust 0a and 65 and position the lock nut 3.5 to 4 turns to the "neutral" side from the "up" and "neutral" switching point.

This state is the highest state of the work equipment in the depth control, and it is only necessary to raise it further using the position control lever, thereby ensuring the gap a between the control bar 81 and the spool pin in Fig. 14. It was.

Next, fully open the stop valve, raise the lift arm, and move the position lever all the way up.Finally, by adjusting the position control bar 80 as described above, you will reach the switching point between "raise" and "neutral". Since the adjustment is made as follows, the first
Since the control bar 80 is stopped at the position shown in Fig. 4, and the control bar 80 protrudes forward by the distance a from the highest position of the depth control, a priority state can be secured. Gap a is between lock nuts 10a and 65,
It is created by 3.5 to 4 rotations.

During other depth control work, as shown in Figure 13, the feedback pin is always controlled and focused in relation to the position of the depth control lever pin, and the spool is near neutral, so naturally the position control bar is Lower pin 83
Since the lift arm is in the lowered position, that is, the pin 83 is in the forward position, when the position control lever is raised to the highest position, the spool is in the "raised" position.

The state shown in Fig. 14 is when the control bars 80 and 81 are closest to the spool pin, and if the gap a is secured at this time, a priority state for position control can always be created.
Make adjustments in this state.

In this case, if the rotation range of the feedback pin 84a at the bottom of the depth control bar 81 is too wide, the balance will be lost, so a rotation regulating part is required in the feedback system of the depth control, and the pin shown in FIG. 50, the pivot plate 48, the elongated hole 63b of the stopper 63 shown in FIG. 7, and the pin 61b.

In the first embodiment, both control bars are pivotally supported by pins, which creates a gap between the horizontal pins, so it is difficult to explain, so it is shown in the drawing of the second embodiment. In the adjusted state shown in FIG. 14, a gap a is created between the horizontal pin and the vertical pin of the depth control bar 24 corresponding to the depth control bar 81, and the control bar 24
4 is adjusted so that it is floating.

(G) Effects of the Invention Since the present invention is configured as described above, it has the following effects.

By configuring as in claim 1,
The depth control lever is at the shallowest position and the depth feed back link is at the shallowest position relative to the position of the position control bar 80 when the position control lever is at the highest position and the lift arm is at the highest position. Since the position of the depth control bar 81 is configured so that when the depth control bar 81 contacts the spool, it is positioned backward by a gap a from the "neutral" direction to the "lower" direction, the position can be adjusted in any control state of the depth control. By rotating the control lever to the highest position, the lift arm can be quickly raised to the highest position regardless of the depth control lever set position, allowing you to quickly raise the lift arm to the highest position when moving around the edge of the field or in a dangerous situation. If this occurs, the work equipment can be quickly lifted and released.

In addition, after the rounding operation is completed at the edge of the field,
By rotating the position control lever all at once to the original lowest position, the depth control bar can return to the state where it has priority over the position control bar in all areas, so the tilling depth position before rotation can be restored. This allows the work equipment to be returned to the plowing depth set by the depth control lever.

This allows you to return to the same plowing depth without having to operate the depth control lever to reset the optimal plowing depth after going around the field edge, and without changing the previous depth control lever position at all. You can then continue your work.

By configuring as in claim 2,
A regulating part is provided to regulate the rotation width of the depth feed back link, and the rotation width of the depth control bar on the feed back link side is regulated, so when making adjustments that give priority to position control, The feedback side of the control bar can be used as the reference position and can be placed in the regulated position, making adjustment easier.Also, by regulating the shallowest position, the rotation range of the control bar is determined, allowing large rotation of the rear cover. This makes it possible to prevent unnecessary excessive rotation of the control bar relative to the width.

By configuring as in claim 3,
A spring is inserted in the depth feedback system so that the depth feedback link is always biased in the shallowest direction, so when one person is adjusting the link system, the depth feedback wire can be removed and the feedback can be adjusted. Since the link is forcibly pulled to its shallowest position, there is no need to operate the rear cover, making adjustment easier.

[Brief explanation of drawings]

FIG. 1 is a plan view of the hydraulic control device of the first embodiment;
FIG. 2 is a side view, FIG. 3 is a side sectional view, FIG. 4 is a rear sectional view, FIG. 5 is a bottom view, and FIG. 6 is a plan view of the hydraulic system showing the second embodiment. Figure 7 is a right side view, Figure 8 is a left side sectional view, Figure 9 is a front sectional view, Figure 10 is a front view of the cylinder head, Figure 11 is a side view of the hydraulic control valve, and Figure 12 is a side view of the hydraulic control valve. The figure shows the control bar when the position control is used and the depth control lever is at the lower limit. Figure 13 is a drawing of the control lever when the depth control is used and the position control lever is at the lower limit. FIG. 14 is a drawing showing the adjustment state of position control and depth control. 5,59...Lift arm, 8,73...Position control lever, 9,72...Depth control lever, 23,80...Position control bar, 24,81...Depth control bar, 10,66... ...Depth feed back link, 48...Pivot plate (regulating part), 63b...
...Elongated hole (regulating part), 12, 64...Spring.

Claims (1)

[Claims] 1 The rotation of the position control lever rotates one end of the position control bar, and the vertical movement of the lift arm rotates the other end of the position control bar in a feedback manner. One end of the depth control bar is rotated by rotating the control lever, and the other end of the depth control bar is rotated in a feedback manner by the forward and backward movement of the depth feedback link. In a configuration in which the tip of the spool is operated by sliding in the middle, the spool tip changes to "raise" operation depending on the pushing direction, and the position control lever is set to the highest position and the lift arm reaches the highest position. The position of the depth control bar when the depth control lever is at its shallowest position and the depth feed back link is at its shallowest position is on the extension line of the spool's sliding direction from "neutral" to "lower" direction. 1. A work machine control device for an agricultural tractor, characterized in that the device is configured to be positioned rearward by a predetermined distance a. 2. The agricultural tractor according to claim 1, characterized in that a regulating portion is provided to regulate the rotation width of the depth feedback link, and the rotation width of the depth control bar on the feedback link side is regulated. work equipment control device. 3. Claim 1, characterized in that a spring that always urges the depth feedback link in the shallowest direction is interposed in the depth feedback system.
A work machine control device for an agricultural tractor as described in 2.