JP3730431B2 - Mid-mount mower lifting link mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of an elevating link for mounting a mower below the abdomen between a front wheel and a rear wheel of a tractor.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a technique in which a mower is attached to an abdomen below a step between a front wheel and a rear wheel of a tractor so as to be able to move up and down is known.
Connect the front link that extends backward from the front part of the tractor and the front and rear parts of the mower with the lift link that extends downward from the middle part, and connect the rear end of the lift link and the three-point link hitch. A method of raising and lowering the mower by raising and lowering the three-point link hitch is common. A structure in which the rear end of the lift arm and the lift cylinder are directly connected has also been proposed.
[0003]
[Problems to be solved by the invention]
However, in the former technique, when cutting and collecting grass at the same time, a grass collecting box is attached to the three-point link hitch. In this case, as the mower moves up and down, the three-point link hitch moves up and down, that is, the grass collection box also moves up and down. Furthermore, since the mowing operation is normally in a floating state, the grass collection box is also grounded.
[0004]
Further, in the structure of direct connection, the mower always moves up and down due to the undulation of the work surface, and the lift cylinder constantly expands and contracts, so that there is a problem that the sliding portion is worn. Further, the hydraulic system could not follow the drastic descent of the mower, etc., resulting in uncutting.
[0005]
[Means for Solving the Problems]
The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
A mid-mount mower elevating link mechanism in which a mower 20 is attached to the lower abdomen between the front wheel 3 and the rear wheel 5 of the tractor 1, and the front portion of the tractor 1 and the front portion of the mower 20 are rotated via a front link 32. It is connected movably, a support member 34 is provided in the front and rear middle part of the tractor 1, the front part of the lift link 35 is rotatably connected, the lift link 35 extends rearward and downward, and the lift link 35 A long hole 35a is provided at the rear, a pin 37 protruding from the rear bracket 36 of the mower 20 is connected so as to be slidable within the long hole 35a, and an elevating cylinder 40 is disposed at the rear of the body of the tractor 1, An elevating cylinder 40 is extended to the rear of the mower 20, and the elevating cylinder 40 and the lift link 35 are rotatably connected via an intermediate link 41.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view of a tractor equipped with a mower by the lifting link mechanism of the present invention,
FIG. 2 is a side view showing raising and lowering the mower,
FIG. 3 is a side view showing a state in which the mower follows the work surface.
[0007]
First, the overall configuration will be described with reference to FIG.
The tractor 1 has a front wheel 3 suspended from an engine frame 2 via a front axle case, and a rear wheel 5 suspended from a transmission case 4 via a rear axle case 6. A lower part of the lower link 7 is pivotally supported at the lower part of the rear axle case 6, a hydraulic case 8 is placed on the upper part of the transmission case 4, and a lift arm 9 is projected from the hydraulic case 8. A lift rod 10 is connected between the lower link 7 and a top link 11 protruding from the rear surface of the hydraulic case 8. In this way, the three-point link type work machine mounting device 12 is configured.
[0008]
Further, a seat 13 is arranged at the upper part of the mission case 4, a step 14 is arranged at the front lower part of the seat 13, a dashboard 15 is arranged at the front part, a handle 16 is arranged at the upper part, An engine is disposed in front of the dashboard 15 and covered with a bonnet 17.
[0009]
And the mower 20 is arrange | positioned under the step 14 between the front wheel 3 and the rear wheel 5, and this mower 20 is suspended by the raising / lowering link mechanism 21 of this invention. The mower 20 has grounding wheels 22, 22... That can be vertically adjusted on both sides of the front and rear of the mower deck 23, and blade mowing blades are housed in the mower deck 23. A gear box 24 is disposed substantially at the center of the shaft, and a universal joint or the like (not shown) is provided between the input shaft 25 projecting rearward from the gear box 24 and the mid PTO shaft 26 projecting forward from the front lower portion of the transmission case 4. So that power can be transmitted.
[0010]
Next, the lifting link mechanism 21 of the present invention will be described.
A pair of left and right support plates 31 project from the front portion of the engine frame 2 to the rear and lower, and the front ends of the pair of left and right front links 32 are pivotally supported at the lower portion of the support plate 31. It is pivotally supported by a bracket 33 provided at the front portion of the mower deck 23. The front link 32 is provided with a clevis 32a so that the length can be adjusted.
[0011]
In addition, a mounting plate serving as a support member 34 is fixed to a midway portion in the front-rear direction of the airframe, in this embodiment, the rear position of the engine frame 2, and the front end of the lift link 35 is pivotally supported on the mounting plate. The link 35 extends rearward and is disposed so as to be substantially parallel to the front link 32. A long hole 35a is provided in the longitudinal direction at the rear portion of the lift link 35, and the bracket 36 provided at the rear portion of the mower deck 23. A pin 37 protruding from the slidably supported in the long hole 35a.
However, instead of providing a long hole in the lift link 35, it is also possible to form a long hole in the bracket 36 in the vertical direction and connect the lift link 35 to the long hole.
[0012]
A bracket 39 is fixed on the rear axle case 6, and the bottom side of the lifting cylinder 40 is pivotally supported by the bracket 39. The lifting cylinder 40 is disposed at the front portion of the rear axle case 6, and its piston rod An intermediate link 41 is pivotally supported at the tip of 40a, and the other end of the intermediate link 41 is pivotally supported by the rear end of the lift link 35.
However, the bracket 39 may be fixed to the aircraft near the mission case 4 or the step 14, and the intermediate link 41 can be connected to the middle part of the lift link 35.
[0013]
In this way, the lift link mechanism 21 is configured, and the lift cylinder 40 is connected to a hydraulic valve provided on the fuselage. The hydraulic valve is operated by a lift lever (not shown) provided near the seat 13, By rotating, the lifting cylinder 40 is expanded and contracted so that the mower 20 can be lifted and lowered.
[0014]
In such a configuration, when a mowing operation is performed using the mower 20, the elevating lever is lowered to ground the mower 20. At this time, the lifting cylinder 40 is not hydraulically applied and can be expanded and contracted, and is lowered by its own weight. As shown in FIG. 2, the front link 32 and the lift link 35 rotate downward while maintaining a substantially parallel state, and the mower 20 also descends substantially horizontally and contacts the ground.
[0015]
When the mower 20 exceeds unevenness or undulations at the time of work, the front link 32 at the front part is pivotally connected to the airframe and the mower, so that it can be moved up and down smoothly. On the other hand, the rear side is pivotally supported by the lifting cylinder, and in the conventional mower, the mower or lift link and the lifting cylinder are pivotally connected, so that the mower suddenly descends and does not come into contact with the ground surface to be damaged. In addition, the valve and oil passage are provided with a restriction to prevent a sudden drop. Therefore, the speed at which the rear side of the mower moves up and down following the unevenness of the ground surface is slow and uncutting has occurred.
However, in the present invention, since the mower 20 is connected through the long hole 35a of the lift link 35, as shown in FIG. 3, when overcoming the unevenness, the pin 37 provided on the bracket 36 of the mower 20 has the long hole. The mower 20 can move up and down smoothly by sliding in the inside 35a. At this time, the lift link 35 also moves up and down. However, since the elevating cylinder 40 is connected to the mower 20 via the intermediate link 41, the elevating cylinder 40 is rotated by a connecting portion between the intermediate link 41 and the elevating cylinder 40. The mower 20 can quickly move up and down following the work surface without expanding and contracting.
[0016]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
A mid-mount mower elevating link mechanism in which a mower 20 is attached to the lower abdomen between the front wheel 3 and the rear wheel 5 of the tractor 1, and the front portion of the tractor 1 and the front portion of the mower 20 are rotated via a front link 32. It is connected movably, a support member 34 is provided in the front and rear middle part of the tractor 1, the front part of the lift link 35 is rotatably connected, the lift link 35 extends rearward and downward, and the lift link 35 A long hole 35a is provided in the rear part, and the pin 37 protruding from the rear bracket 36 of the mower 20 is connected so as to be slidable in the long hole 35a, so that the front part of the mower can be moved up and down by rotating the front link. The rear part can slide up and down freely in the long hole, so that the front and rear posture of the mower is not restricted, and the front and rear grounding wheels are always in contact with the work surface and clean without cutting Mowing Than it is.
[0017]
Further , a lifting cylinder 40 is disposed at the rear of the tractor 1 body, the lifting cylinder 40 is extended to the rear of the mower 20, and the lifting cylinder 40 and the lift link 35 are rotatably connected via an intermediate link 41. Therefore, the elevating cylinder cannot be quickly expanded or contracted due to the viscous resistance of the hydraulic oil or the throttle, etc., but since the intermediate link is rotatable, the vertical movement of the mower is not directly affected by the elevating cylinder and the followability to the work surface is improved. As a result, there is no leftover, and the expansion and contraction of the lifting cylinder is reduced, and wear of the sliding portion can be prevented.
[Brief description of the drawings]
FIG. 1 is a side view of a tractor equipped with a mower by an elevating link mechanism of the present invention.
FIG. 2 is a side view showing raising and lowering a mower.
FIG. 3 is a side view showing a state in which the mower follows the work surface.
[Explanation of symbols]
3 Front Wheel 5 Rear Wheel 20 Mower 32 Front Link 34 Mounting Plate 35 Lift Link 35a Long Hole 40 Lifting Cylinder 41 Intermediate Link

Claims (1)

This is a mid-mount mower elevating link mechanism in which a mower 20 is attached to the lower abdomen between the front wheel 3 and the rear wheel 5 of the tractor 1. It is connected movably, a support member 34 is provided in the front and rear middle part of the tractor 1, the front part of the lift link 35 is rotatably connected, the lift link 35 extends rearward and downward, and the lift link 35 A long hole 35a is provided at the rear, a pin 37 protruding from the rear bracket 36 of the mower 20 is connected so as to be slidable within the long hole 35a, and an elevating cylinder 40 is disposed at the rear of the body of the tractor 1, The lifting cylinder 40 is extended to the rear of the mower 20, and the lifting cylinder 40 and the lift link 35 are rotatably connected via an intermediate link 41. Click mechanism.

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