JP2002045005A - Work machine lifting device for agricultural tractors - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damages of related mechanisms by absorbing an excessive feedback amount following a jump of a rear cover of a rotary implement. SOLUTION: This apparatus for lifting and lowering an implement in an agricultural tractor is equipped with a setting means which is made controllable in rise and fall so as to maintain a set height position of the implement by connecting a means to subject the change of an implement position to a feedback while detecting the implement position to a hydraulic valve to be linked to and to lift and lower an implement liftably connected to a machine body and sets a set height of the implement in the middle of the feedback. A linkage release mechanism which receives an excessive feedback amount and intercepts a reverse interlocking to the setting means is installed between the setting means and the feedback means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device for an agricultural tractor.

[0002]

2. Description of the Related Art For example, in a rotary working machine, depth control is performed so as to reach a set plowing depth by detecting vertical movement of a rear cover.
That is, in order to feed back the detection result of the rear cover, the hydraulic valve is generally interlocked via a wire link mechanism.

[0003] By the way, the rear cover may be raised and rotated and held large for inspection of the working machine, but the feedback amount is usually excessively large as compared with the allowable movable range of the valve spool. In such a case, unless the excessive feedback amount is absorbed by any of the linking means, there is a possibility that each part may be damaged.

[0004]

SUMMARY OF THE INVENTION Accordingly, the invention according to claim 1 is to provide a hydraulic valve for vertically moving a working machine connected to a machine body so as to be able to move up and down, and to feedback a change in the working machine posture while detecting the posture of the working machine. Means for controlling the height of the working machine, and setting means for setting the set height of the working machine during the feedback. In the meantime, the work implement lifting / lowering device of the agricultural tractor is configured to include a linkage release mechanism that receives the excessive feedback amount and blocks the reverse linkage to the setting unit.

According to a second aspect of the present invention, the feedback means is a wire linking means, the inner wire 25a is linked between the work implement attitude detecting section and the hydraulic valve, and one end of the outer wire 25b is always connected to the second link. , 3 links and a link pin are connected to the first link 34 which is linked to the forward and backward swinging motion of the setting lever 40, and a release mechanism is provided to cut off the link between the link pin and the first link 34 when an excessive feedback amount is received. The construction of the lifting device for agricultural tractors.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes a small tractor having front wheels 2 and 2 and rear wheels 3 and 3 at the front and rear portions of the fuselage, and an engine 5 mounted and installed in a hood 4. The engine 5 has a flywheel 6 on a front side and a radiator 7. Is attached to the fuselage in the opposite direction as usual so that it is on the rear side.

An output shaft 8 projecting rearward from the engine 5 and an input shaft 10 mounted on the front wall of the transmission case 9 are interlocked via a universal joint shaft 11 to rotate the engine 5 side. The power is transmitted to the transmission case 9 side. Note that a main transmission mechanism and an auxiliary transmission mechanism are provided inside the transmission case 9, and left and right rear wheels are driven via a differential mechanism. Also, the transmission mechanism is configured to branch off from the transmission mechanism and output front wheel power, so that the front wheels 2 and 2 can be driven.

A rotary working machine 13 is mounted on the rear of the transmission case 9 via a three-point link mechanism 12.
The rotary working machine 13 is configured to be able to move up and down by a hydraulic cylinder mechanism 14 provided horizontally on a rear upper surface of a transmission case 9. The hydraulic lifting operation mechanism will be described with reference to FIG.

A valve 15 for switching the hydraulic cylinder mechanism 14 to supply and discharge the pressurized oil is provided near the cylinder mechanism 14 so that a spool 16 can move in and out in the front-rear direction. That is, a support plate 18 on which the elevating lever 17 is mounted is provided at one end of a rotating shaft 20 that rotates around a horizontal axis and has a pressing member 19 that contacts the tip of the spool 16. By operating the lifting lever 17 to rotate back and forth, the pressing member 19 is swung, and the rotary mechanism 13 is moved up and down by changing the cylinder mechanism to shortening, neutral stop, and extension. When the lifting lever 17 rotates forward, the spool 16 extends forward by the spring 21 and switches the valve 15 to the lower side. Conversely, when the lever 17 rotates backward, the pressing member 19
Is pressed to switch the valve 15 up. The middle part has a neutral position.

The support plate 18 can be moved up and down not only by operating the lifting lever 17 but also by feeding back the movement of a detector for detecting the tillage depth, such as the rear cover of the rotary working machine 13, so that the rear cover can be moved. 2
An interlocking link mechanism 24 is interposed between the rotary cover 2 and the rotary cover 23 to convert the vertical movement of the rear cover 22 into the forward and backward movement of the wire 25 so that one end of the wire 25 can be connected to the support plate 18 and fed back. And The link mechanism 24 includes a support shaft 26 having a horizontal axis set as appropriate on the rear upper surface of the rotary cover 23, a first swing arm 27 provided on the support shaft 26 at a substantially diagonal position, and a first swing arm 27.
And a wire 25 linked to the second swing arm 29. When the rear cover 22 is lifted, the wire 25 is pulled to move the support plate 18 to the working machine rising side. is there.

The wire 25 is composed of an inner wire 25a and an outer wire 25b so that the setting of the tillage depth can be changed. The inner wire 25a has a rear end connected to the link mechanism 24 of the rear cover 22 and a front end connected to the front end. The rear end of the outer wire 25b is connected to the support plate 18 by a bracket 30 provided at an appropriate position on the rotary cover 23.
, While the front end of the outer wire 25b is connected to a setting link mechanism 31 for setting a plowing depth capable of changing the front-rear position. That is, the bridge member 32 provided at the front end of the outer wire 25b is connected to the first link 34 provided rotatably around the first horizontal axis 33. In the vicinity of the first link 34, a second link 36 that rotates around a second horizontal axis 35 having an axis parallel to the first horizontal axis 33, and a second link 36 that is on the same plane as the second link 36, The third link 37 is supported by the same horizontal axis 33 as the first link 34 and is in contact with the rear edge of the second link 36 on the cam surface. A linking pin 38 is provided in a holding manner over the concave portion 34a formed on the rear surface of the connecting pin 38.
The pin 38 is formed in the shape of a pin with a flange on the head.
It is urged by a spring 39 so as to enter the inside of a.
The setting link 40 is connected to the second link 36 of the first to third links 34, 36 and 37,
When the link 36 is rocked back and forth, the fixed position of the outer wire 25b is displaced forward or backward, so that the set plowing depth can be changed to a shallow depth. For example, when the setting lever 40 is tilted forward from the standard position, the outer wire 25b is pulled forward while the support plate 18 is kept neutral, for example, and the connection point of the second swing arm 29 with the inner wire 25a is moved forward. Get closer. That is, the setting is changed to a state where the tillage depth is deep. When the setting lever 40 is tilted backward from the standard position, the setting tillage depth becomes shallower, contrary to the above.

Reference numeral 41 denotes a first link 3 provided on the horizontal shaft 33.
This is a lining for fixing the braking position that holds the fourth and third links 37 in position. Next, the linkage release mechanism by the first link 34 to the third link 37 will be described. As described above, the first link 34 and the third link 37 are connected to the link pin 38.
And can be displaced back and forth by the forward and backward swinging motion of the second link 36.
When a sudden load such as is suddenly lifted acts on the spool 16 of the valve 15 within a predetermined range, if the sudden load exceeds the predetermined range, each part may be damaged. There is a configuration that can avoid this. That is, the first link 34 operates until the spool 16 is locked by the abrupt pulling action of the inner wire 25a, and when this pulling action continues, the first link 34 rotates counterclockwise to rotate the outer wire 25b. Attempts to accommodate this by increasing the working length. Following the movement of the first link 34, the third link 3
When the seventh and second links 36 are actuated, they are restricted to a certain range of movement, and may eventually break. However, the link pin is moved along the cam surface 34b formed on the first link 34. The first link 34 can rotate in a counterclockwise direction while the third link 37 can be moved to leave the third link 37 at that position. As described above, the first link 34 and the third link 37 are linked by the link pins 38 in the recesses 34a, 37a, while the cam surface 34b that guides the link pins 38 is formed on the first link 34 to link and release the link. 42.

Next, the operation of the above example will be described. In the field, when performing the tilling work while moving the machine forward, the lifting lever 17 is turned forward to lower, and then the setting lever 4
Operate 0 to set the desired tillage depth. Setting lever 4
When 0 is tilted forward from the standard position, the second link 36 also swings to increase the set plowing depth (FIG. 3). Conversely, when tilting 0 from the standard position to the rear, the second link 36 also swings and sets. Reduce the cultivation depth (Fig. 4).

When the tilling operation is started, the rotary work machine 1
3 tilling the soil, but when the position of the rear cover 22 swings up and down, the movement is linked to the link mechanism 24 and the wire 2.
The control signal is fed back to the valve 15 spool 16 via the valve 5, and causes the hydraulic cylinder mechanism 14 to expand and contract, thereby controlling the rotary working machine 13 to move up and down.

In inspecting the rotary work machine 13, for example, replacing a claw, it is necessary to raise the work machine and further flip the rear cover 22 up. At this time, the inner wire 25
a is pulled to press the spool 16 to the full allowable sliding range, but if the bouncing still continues, the first link 34 swings counterclockwise to move the link pin 38 to its cam surface 34b. Slide. Thus, the link pin 38 is in the recess 3
4a and 37a, and the third link 37 and thus the second link 36 are disconnected from the first link 34. Therefore, even if an impact is suddenly applied, the linkage release mechanism 42 including the first to third link mechanisms 12 is operated to release the relation of the link's integrally regulated state, so that an excessive impact force is transmitted to each part. No (Fig. 5).

FIG. 7 shows another embodiment, in which a link 50 interlocking with the setting lever 40 is supported by a shaft 52 via a lining 51 for holding a position, and a convex cam 50a is formed at the base of the link 50. I have. The link 53 for supporting the outer wire 25b has an L-shape and is swingably provided on a support link 55 which is separately supported by a shaft 54 on the machine body. On the side, the piece member 32 of the outer wire 25b is locked. The convex cam 50a always fits into the concave portion 55a, but when receiving an excessive force, the convex cam 50a comes into contact with the fan-shaped cam portion 55b of the support link 55 and escapes. When the action of pulling the inner wire 25a is applied, the inner wire 25a
Is pulled and the valve 15 spool 16 is slid in the upward direction. If the excessive inner wire 25a continues to be pulled from the convex cam 50a beyond the movable range of the spool 16, the support link 55 rotates around the support shaft 54 and comes into contact with the fan-shaped cam portion 55a from the concave portion to escape. Things.

FIG. 8 shows still another embodiment, which comprises a base side link 60 of the setting lever 40 and a wire side link 61 for locking one end of the outer wire 25b, and these are connected to separate shafts 62 and 63. Supported. Normally, both pins 65 are integrated with the shaft 63 by the action of the torque spring 64 wound around the shaft 62.
, So that not only the base side link 60 but also the wire side link 61 can follow the movement of the setting lever 40. However, when an excessive feedback amount acts on the wire side link 61, the torque spring 64
The wire-side link 61 is retracted against the pressure (dotted line in FIG. 8).
This is a configuration that absorbs an excessive amount of operation.

[0018]

According to the first aspect of the present invention, the hydraulic valve for vertically moving the working machine connected to the machine body so as to be able to move up and down is provided with the means for detecting the working machine attitude and feeding back the change in the attitude. It is configured to be connected and connected so as to be able to raise and lower to maintain the set working machine height position, and in the middle of this feedback, setting means for setting the working machine set height is provided, and between the setting means and the feedback means. Since the link release mechanism that receives the excessive feedback amount and blocks the reverse linkage to the setting unit is configured, the linkage release mechanism is activated when the excessive feedback amount is generated, thereby disconnecting the reverse linkage to the setting unit. Even if the spool 16 has a small movement, when the feedback amount is excessive, the spool 16 can be appropriately released and used without damaging each part.

Further, the inner wire 25 may be provided.
a is linked between the work implement attitude detector and the hydraulic valve, and one end of the outer wire 25b is always connected to the second or third
A connection mechanism is provided via a link and a linking pin to be connected to the first link 34 which is linked to the forward and backward swinging motion of the setting lever 40, and a release mechanism is provided to cut off the linking between the linking pin and the first link 34 when an excessive feedback amount is received. Therefore, the link can be released by a set of the link and the pin without using a complicated structure, and the production can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part.

FIG. 2 is an overall side view of the agricultural tractor.

FIG. 3 is an explanatory diagram of an operation link.

FIG. 4 is an explanatory diagram of an operation link.

FIG. 5 is an explanatory diagram of an operation link.

FIG. 6 is a plan view of an operation link.

FIG. 7 is another embodiment of the actuation link.

FIG. 8 is yet another embodiment of the actuation link.

[Explanation of symbols]

1 tractor, 2 front wheel, 3 rear wheel, 4 hood,
5 ... engine, 6 ... flywheel, 7 ... radiator, 8
... output shaft, 9 ... mission case, 10 ... input shaft, 11
... Universal joint shaft, 12 ... 3-point link mechanism, 13 ... Rotary work machine, 14 ... Hydraulic cylinder mechanism, 15 ... Valve, 16
... Spool, 17 ... Elevating lever, 18 ... Support plate, 19 ...
Pressing member, 20: rotating shaft, 21: spring, 22: rear cover, 23: rotary cover, 24: link mechanism, 2
5: Wire, 25a: Inner wire, 25b: Outer wire, 26: Support shaft, 27: First swing arm, 28: Back side link, 29: Second swing arm, 30: Bracket, 31: Setting link mechanism, 32 ... piece member, 33 ... first
Horizontal axis, 34: first link, 35: second horizontal axis, 36: second
Link, 37: third link, 38: link pin, 39: spring, 40: setting lever, 41: lining, 42: link release mechanism

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B304 KA03 KA04 LA02 LA06 LB05 LB15 MA02 MB02 MC06 MC14 PC02 PC08 RA01

Claims (2)

[Claims] 1. A work valve that is connected to a machine body so as to be able to move up and down freely is connected to a hydraulic valve that moves up and down to connect a means for feeding back the change of the work machine while detecting the posture of the work machine to maintain a set work machine height position. It is configured to be able to raise and lower as much as possible,
In the course of this feedback, a setting means for setting the set height of the work implement is provided, and between the setting means and the feedback means, there is provided a linkage release mechanism for receiving an excessive amount of feedback and interrupting reverse linkage to the setting means. A lifting device for agricultural tractor work equipment. 2. The apparatus according to claim 1, wherein the feedback means is a wire linking means, the inner wire 25a is linked between the work implement attitude detecting section and the hydraulic valve, and one end of the outer wire 25b is always connected to the second and third links. And a first link 34 interlocking with the swinging motion of the setting lever 40 through the link pin, and a release mechanism provided to disconnect the link between the link pin and the first link 34 when an excessive feedback amount is received. Tractor work equipment lifting device.