JP3593736B2 - Work machine automatic lifting device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an automatic lifting / lowering device for a working machine connected to a power farm machine, and more particularly to an automatic lifting / lowering device for a working machine that operates in accordance with a retreat operation of a body.
[0002]
[Prior art]
In a power farm machine in which a ground working machine is connected to the rear of the machine body so that the machine can move up and down, it is necessary to operate the lift lever to raise the working machine when retreating the machine body during plowing in a field.
[0003]
As a device that automatically raises the work machine when the body retreats, the applicant of the present application provided a swing mechanism at the reverse position of the shift lever, and mechanically reads the shift operation to the reverse position by this swing mechanism, There has been proposed a work implement automatic elevating device formed to rotate a switching shaft of a spool of a lift cylinder upward (Japanese Patent Application No. 6-221996).
[0004]
As shown in FIG. 6, the work implement automatic elevating device has a regulating member 2 pivotally mounted near a switching shaft 1 of a spool, and the regulating member 2 is provided with an arc-shaped guide portion 3 and a stopper portion 4. A swing mechanism (not shown) is provided at the reverse position of the speed change lever, and the rod 5 is connected to the swing mechanism, and a long hole 7 is formed in a link 6 connected to the rear end of the rod 5. I do. Then, a connecting arm 8 is fixed to the switching shaft 1 of the spool, and a distal end 8 a of the connecting arm 8 is locked to the guide portion 3 of the restricting tool 2 and the elongated hole 7 of the link 6.
[0005]
Thus, when the shift lever is shifted to the reverse position by the operator, the rod 5 is pulled forward, the link 6 is also moved integrally, and the connecting arm 8 engaged with the long hole 7 of the link 6 is pushed forward. Is done. Accordingly, as shown in FIG. 7, the switching shaft 1 of the spool rotates counterclockwise in the figure, the spool in the lift cylinder is switched to the lift side of the lift arm 9, and the working machine rises.
[0006]
At this time, the distal end 8 a of the connecting arm 8 is locked by the stopper 4 of the restricting tool 2, and the switching shaft 1 of the spool is locked at the raised position of the lift arm 9. Even if the shift lever is shifted from the reverse position to another position and the rod 5 returns to the original position, the switching shaft 1 of the spool is locked at the raised position, and the work implement is held in the raised state.
[0007]
[Problems to be solved by the invention]
As described above, the work implement automatic lifting / lowering device of which the present applicant is applying mechanically detects the shift of the shift lever to the reverse position, and turns the spool switching shaft to the ascending side in a mechanical configuration. Moving. Because of the mechanical configuration, for example, when the power circuit of the power agricultural machine is turned off at the end of work and the operator leaves the machine, when another person mistakenly shifts the shift lever to the reverse position, the power is turned off. Nevertheless, the spool switching shaft is switched to the raised position and locked.
[0008]
In that case, the hydraulic circuit does not operate because the power is off, and the work machine does not rise.However, when the power agricultural machine is turned on at the start of the next work, the lift cylinder spool moves to the raised position. In this state, the hydraulic circuit operates. As described above, even when the shift lever is returned from the reverse position to another position, the switching shaft of the spool remains locked at the raised position. The lock of the machine cannot be confirmed, and the work equipment may suddenly rise and cause an accident.
[0009]
Therefore, when the shift lever is shifted to the reverse position during the work, the spool of the lift cylinder is switched to the raised position to raise the work implement, and after the work is completed, the shift cylinder is shifted to the reverse position, and the lift cylinder is moved to the reverse position. There is a technical problem to be solved in order to prevent the spool from being switched, and an object of the present invention is to solve this problem.
[0010]
[Means for Solving the Problems]
The present invention has been proposed in order to achieve the above-mentioned object, and the up-down movement of a lift lever provided in a driver's seat switches a spool in a lift cylinder to rotate a lift arm, which is connected to a rear portion of the fuselage. In a power agricultural machine in which a ground work machine can be freely raised and lowered, a first switch that is turned on when a shift lever is shifted to a reverse position and a second switch that is turned on when the lift lever is moved to a highest position. An electric motor having a rocking shaft that tilts in one direction when the first switch is turned on and tilts in the other direction when the second switch is turned on. A motor arm is fixed to the swing shaft, and an arm shaft is provided parallel to the swing shaft and at a position lower than the electric motor, and a center portion of the rotating arm is pivotally connected to the arm shaft. A link arm is fixed to the switching shaft of the spool of the rotor, a rear portion of the rod is connected to a tip end of the link arm, and a front portion of the rod is connected to a lower end portion of the rotating arm. The upper end of the moving arm is connected to the tip of the motor arm, and when the first switch is turned on, the switching shaft of the spool is turned upward, and the second switch is turned on. An automatic lifting / lowering device for a working machine , wherein the lifting state of the working machine is released when it is turned on, and the switching shaft of the spool is rotated downward by a subsequent downward movement of the lift arm .
[0011]
[Action]
When the operator shifts the shift lever to the reverse position in order to retreat the aircraft during the operation, the first switch is turned on by this shift operation, the electric motor is driven, and the swing shaft is tilted in one direction. . At this time, the motor arm fixed to the swing shaft turns in the same direction, and the turning arm turns to pull the rod forward. Accordingly, the link arm connected to the rear portion of the rod tilts forward, the switching shaft of the spool rotates upward, and the spool of the lift cylinder switches to the upward position.
[0012]
Thus, the lift arm rotates upward and the work implement rises. At this time, since the swing shaft of the electric motor is locked in a state of being tilted in one direction, the work implement is held in the raised state even when the shift lever is shifted from the reverse position to another position.
[0013]
To release the lifting state of the work machine, the lift lever is temporarily moved up to the highest position. By operating the lift lever, the second switch is turned on, the electric motor is driven in the reverse direction, and the swing shaft tilts in the other direction. Then, the motor arm fixed to the swing shaft rotates in the same direction, and the rotation arm rotates in the opposite direction.
[0014]
At this time, if the lift lever is moved down from the highest position, the link arm tilts backward following the lowering operation of the lift lever, the switching shaft of the spool rotates to the lower side, and the spool of the lift cylinder lowers. Switch to position. Thus, the lift arm rotates downward and the work implement descends.
[0015]
After the work is completed with the work machine lowered, the power of the power farm machine is turned off. Therefore, even if the shift lever is operated to the reverse position, the first switch is not turned on and the electric motor is driven. Not done. Therefore, the switching axis of the spool of the lift cylinder does not switch to the ascending side due to an erroneous operation after the work is completed.
[0016]
【Example】
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 shows a tractor 11 as an example of a powered agricultural machine. An engine 13 is mounted on a front portion of a body 12, and the power of the engine 13 is reduced by a transmission 14 and then transmitted through a differential device 15. And transmitted to the rear wheels 16, 16.
[0017]
A gearshift lever 18 is provided on the side of the driver's seat 17 and the operator inclines the gearshift lever 18 back and forth and left and right, so that the gear combination of the transmission 14 is shifted from the forward low speed position to the forward middle speed or forward high speed position, or It is shifted to an arbitrary position to the reverse position.
[0018]
A work machine such as a rotary is connected to the rear of the body 12 and a lift lever 19 provided on the side of the driver's seat 17 is moved up and down to switch the spool of a lift cylinder 22 described later to lift arms 20, 20. Is turned so that the working machine can be raised and lowered arbitrarily by an operator.
[0019]
FIG. 2 shows a plane of the driver's seat 17. A change metal 21 containing the transmission 14 is provided at a front portion below the driver's seat 17, and a cylinder case 23 containing a lift cylinder 22 is provided at the rear. I have. A first switch 25 that is turned on when the shift lever 18 is shifted to the reverse position is provided near the shift arm 24 of the shift lever 18, and the lift lever 19 is located near the base end of the lift lever 19. There is provided a second switch 26 that is turned on when the switch is at the highest position. The first and second switches 25 and 26 are connected to an electric motor 28 via a controller 27, respectively. As described later, the switching shaft 29 of the spool of the lift cylinder 22 and the shaft of the electric motor 28 are connected by a rod 30, a rotating arm 31, and the like.
[0020]
Further, a manual up / down switch 33 is provided on the side panel 32 on the side of the driver's seat 17, and the operation of the manual up / down switch 33 raises and lowers the work implement to the highest position or the lowest position. Further, an instrument panel 34 provided in front of the driver's seat 17 is provided with a main switch 35 and an automatic backup switch 36 in addition to instruments. The main switch 35 is a switch for turning on and off the power supply circuit of the tractor 11, and the automatic backup switch 36 is a switch for turning on and off the control for automatically raising the work equipment when the body 12 moves backward as described later.
[0021]
As shown in FIGS. 2 and 3, a bracket 38 having an inverted L-shape in front view is fixed between the right side of the change metal 21 and the right fender 37, and the controller 38 is provided above a horizontal plane of the bracket 38. The electric motor 28 is mounted on a vertical surface of the bracket 38. By fixing the bracket 38 between the change metal 21 and the right fender 37, the strength of the right fender 37 is increased.
[0022]
Further, by disposing the controller 27 above the horizontal surface of the bracket 38, muddy water splashed from the field does not directly scatter to the controller 27, and the waterproofness and vibration resistance of the electronic components inside the controller 27 can be improved. . Further, by assembling the electric motor 28, the rod 30, the rotating arm 31, and the like in advance to the bracket 38, a subassembly becomes possible and the assembling property is improved.
[0023]
FIG. 4 shows the connection state between the electric motor 28 and the switching shaft 29 of the spool of the lift cylinder 22. As described above, the electric motor 28 is mounted on the vertical surface of the bracket 38. The electric motor 28 uses a motor for a wiper. When the first switch 25 is turned on, the swing shaft 39 is tilted counterclockwise in the drawing, and the second switch 26 is turned on. When this happens, the swing shaft 39 tilts clockwise.
[0024]
A motor arm 40 is fixed to the swing shaft 39. The motor arm 40 rotates integrally with the swing shaft 39, and the rotation position of the motor arm 40 when the first switch 25 is turned on. An angle difference between the rotation position of the motor arm 40 when the second switch 26 is turned on and the rotation position of the motor arm 40 is slightly less than about 180 degrees. Further, an arm shaft 41 is fixedly provided at a position parallel to the swing shaft 39 and lower than the electric motor 28, and the central portion of the above-described rotating arm 31 is pivotally connected to the arm shaft 41.
[0025]
On the other hand, a link arm 43 is fixedly mounted on the switching shaft 29 of the spool, a rear portion of the rod 30 is connected to a tip end of the link arm 43, and a front portion of the rod 30 is provided at a lower end portion of the rotating arm 31. The boss 44 is loosely inserted into the boss 44, and a nut 45 is further screwed onto the boss 44 to prevent the boss 44 from dropping forward. The upper end of the rotating arm 31 and the tip of the motor arm 40 are connected by a motor rod 46.
[0026]
Thus, in the initial state when the main switch 35 of the tractor 11 is turned on, the swinging shaft 39 and the motor arm 40 of the electric motor 28, and the rotating arm 31, the rod 30, and the link arm 43 are in the illustrated state. Has become. At this time, the spool switching shaft 29 is rotating so that the spool of the lift cylinder 22 is in the lowered position.
[0027]
Here, when the automatic backup switch 36 is turned on and the operator shifts the speed change lever 18 to the reverse position in order to retreat the body 12, the first switch 25 is turned on, and the electric motor 28 is driven. The swing shaft 39 is tilted counterclockwise in the drawing, and the motor arm 40 is also integrally rotated counterclockwise. Since the tip of the motor arm 40 and the upper end of the turning arm 31 are connected by the motor rod 46, the turning of the motor arm 40 turns the turning arm 31 clockwise around the arm shaft 41. I do. Accordingly, as shown by the solid line in FIG. 5, the rod 30 is pulled forward through the boss 44 provided at the lower end of the rotating arm 31, the link arm 43 is tilted forward, and the spool switching shaft 29 is moved. Rotate to the ascending side.
[0028]
Thus, the spool of the lift cylinder 22 switches to the raised position, the lift arms 20, 20 rotate upward, and the work implement rises. At this time, since the swing shaft 39 of the electric motor 28 is locked in a state where it is tilted counterclockwise, the shift lever 18 is shifted from the reverse position to another position, and the first switch 25 is turned off. In this case, the connecting members such as the motor arm 40 and the rotating arm 31 do not move from the position shown by the solid line, and the switching shaft 29 of the spool is fixed at the raised position. Hold and do not fall unexpectedly. If the nut 45 is rotated to adjust the mounting length of the rod 30, the height at which the working machine is raised can be changed.
[0029]
Next, when the lifting state of the work machine shown in FIG. 5 is released, the lift lever 19 is temporarily moved up to the highest position. At that time, the base end of the lift lever 19 contacts the second switch 26, the second switch 26 is turned on, the electric motor 28 is driven in the reverse direction, and the swing shaft 39 is turned clockwise. Lean on. Therefore, as shown by the two-dot chain line in the figure, the motor arm 40 turns downward, and the turning arm 31 turns counterclockwise about the arm shaft 41. Then, the boss 44 provided at the lower end of the rotating arm 31 slides rearward on the rod 30 and separates from the nut 45, so that the link arm 43 can be tilted rearward, so that the working machine can be raised and held. It is released.
[0030]
At this time, if the lift lever 19 is moved downward from the highest position, the link arm 43 is tilted backward following the lowering operation of the lift lever 19, and returns to the state shown in FIG. The switching shaft 29 rotates downward. Accordingly, the spool of the lift cylinder 22 switches to the lowered position, the lift arms 20, 20 rotate downward, and the work implement descends.
[0031]
As shown in FIG. 2, a manual up / down switch 33 is provided on the side panel 32. When the manual up / down switch 33 is operated to the up side, the shift position of the main shift lever 18 and the lift lever 19 Irrespective of the vertical position, the spool of the lift cylinder 22 switches to the raised position, and the work implement rises to the highest position. Also, when the manual up / down switch 33 is operated to the lower side, the spool of the lift cylinder 22 is switched to the lower position regardless of the position of the main shift lever 18 and the lift lever 19, and the work machine is lowered to the lowermost position. .
[0032]
When the work is completed with the work implement lowered, the main switch 35 is turned off to cut off the power supply circuit of the tractor 11. Therefore, even if the shift lever 18 is operated to the reverse position after the work is completed, the first switch 25 is not turned on, and the spool switching shaft 29 of the lift cylinder 22 does not rotate upward, so that the next When the main switch 35 is turned on at the start of the work, the work machine does not suddenly rise.
[0033]
The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.
[0034]
【The invention's effect】
As described in detail in the above embodiment, when the shift lever is shifted to the reverse position, the electric motor is driven, and the switching shaft of the spool of the lift cylinder is moved upward through the rotating arm or the rod. The lift cylinder rotates so that the spool of the lift cylinder is locked at the raised position. Therefore, when the body is retracted, the work machine automatically rises and is maintained at a constant height, so that the operability of the operator is significantly improved.
[0035]
Then, since the shift to the reverse position is electrically detected, the configuration is simplified. Also, since the power supply circuit is cut off after the work is completed, the spool of the lift cylinder does not switch to the raised position even when the shift lever is shifted to the reverse position, and the work equipment does not suddenly rise when re-working. It can also contribute to improving safety.
[Brief description of the drawings]
FIG. 1 is a side view of a tractor, showing one embodiment of the present invention.
FIG. 2 is a plan view of a driver's seat.
FIG. 3 is a front view showing a mounting portion of the bracket.
FIG. 4 is a side view showing a connection state between the electric motor and a switching shaft of the spool when the spool of the lift cylinder is at a lowered position.
FIG. 5 is a side view showing a connection state between the electric motor and a switching shaft of the spool when the spool of the lift cylinder is at a raised position.
FIG. 6 shows a conventional example, and is a side view of a switching shaft of a spool when a spool of a lift cylinder is at a lowered position.
FIG. 7 shows a conventional example, and is a side view of a spool switching shaft when a lift cylinder spool is at a raised position.
[Explanation of symbols]
11 Tractor 12 Body 17 Driver's seat 18 Shift lever 19 Lift lever 20 Lift arm 22 Lift cylinder 25 First switch 26 Second switch 28 Electric motor 29 Spool switching shaft 30 Rod 31 Rotating arm 39 Swing shaft 40 Motor arm 41 Arm shaft 43 Link arm

Claims (1)

With the vertical movement of the lift lever provided in the driver's seat, the spool in the lift cylinder is switched to rotate the lift arm, and the power-operated agricultural machine that allows the ground work machine connected to the rear of the machine to move up and down A first switch that is turned on when shifting to the reverse position, a second switch that is turned on when the lift lever is moved to the highest position, and a tilt in one direction when the first switch is turned on. An electric motor having an oscillating shaft that rotates and tilts in the other direction when the second switch is turned on. A motor arm is fixed to the oscillating shaft of the electric motor, and the motor arm is parallel to the oscillating shaft. Further, an arm shaft is provided at a position lower than the electric motor, and a central portion of the rotating arm is pivotally attached to the arm shaft. On the other hand, a link arm is fixed to the switching shaft of the spool of the lift cylinder, and While connecting the rear part of the rod to the tip of the arm, connecting the front part of the rod to the lower end of the rotating arm, and further connecting the upper end of the rotating arm to the distal end of the motor arm When the first switch is turned on, the switching shaft of the spool is rotated upward, and when the second switch is turned on, the lifting state of the work machine is released. An automatic lifting and lowering device for a working machine , wherein the switching shaft of the spool is rotated downward by a subsequent downward movement of the lift arm .

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