JP2984932B2 - Lifting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is mounted on the front of a trough and lifts a front loader or the like for loading or excavating, burying back, preparing a field for leveling or snow removal, etc. of compost or hay. Work equipment.

Conventional technology Conventionally, as shown in Japanese Utility Model Application Laid-Open No. 63-151554, a lift arm is moved up and down by driving a loader elevating cylinder by manual lever operation, and a bucket is mounted on the lift arm, and dumping is performed by manual lever operation. There is a technique of driving a cylinder to scoop or dump a bucket.

[Problem to be Solved by the Invention] In the conventional technique, since a manual lever is attached to a controller provided on the tractor, the operation of removing the on-roller from the tractor and operating the manual lever can be easily performed. However, when an automatic lever for automatically lifting and lowering the lift arm is provided in the controller, the lift arm can be easily raised and lowered in parallel with the driving operation such as forward and backward traveling of the tractor, while the controller is removed from the tractor. When operating outside the vehicle, there is a problem that the automatic lever is incorrectly operated. Further, even if a changeover switch that enables the automatic lever to move up and down is provided, if the changeover switch is erroneously operated, there is a problem that erroneous operation of the automatic lever cannot be prevented.

Means for Solving the Problems The present invention includes a loader elevating cylinder for elevating and lowering a lift arm mounted on a tractor, and a dump cylinder for operating a bucket provided on the lift arm. And a switch for turning on and off the automatic raising and lowering of the automatic lever, in a lifting working machine provided with a sensor for detecting the automatic lever, and a controller for installing a manual lever for operating the cylinder and an automatic lever for automatically raising and lowering the lift arm to a set height. The controller is equipped with a detachable switch that detects the attachment and detachment of the controller to and from the machine, the controller is mounted on the tractor, and automatic control of the automatic lever is performed by switching the changeover switch from off to on. It is characterized by.

[Operation] Therefore, the controller is detached from the tractor because the mounting of the controller on the tractor unit is confirmed by the detachable switch, and the lift arm of the automatic lever can be automatically moved up and down by switching the selector switch off and on. Even if the changeover switch is turned on due to erroneous operation, the automatic lever can be prevented from automatically moving up and down by the detachable switch, and even if the detachable switch is turned on when the controller is mounted on the tractor with the changeover switch on. The automatic lever can be prevented from moving up and down until the condition is satisfied again by switching the selector switch off and on, and the operator can recognize and operate the automatic lever automatically by switching the selector switch off and on to simplify the operation of the tractor. And easy workability with lifting and lowering of the lift arm. Is shall.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a control circuit diagram of the front loader, FIG. 2 is an overall side view, and FIG. 3 is a side view of the front loader.
In the figure, (1) is a tractor which is a traveling body, (2) and (3) are front and rear wheels of the tractor (1), (4) is a chassis on which a front wheel (2) is mounted, and (5) is a chassis. An engine mounted on the chassis (4), (6) is a power transmission case connected to the engine (5) to mount the rear wheel (3), and (7) is mounted on a rear upper surface of the case (6). A driver's seat (8) is a steering handle, and a bucket (10) as an attachment of a front loader (9) is mounted in front of the tractor (1) via a pair of left and right lift arms (11). .
In the drawing, (12) is a rear mounting frame that supports the lift arm (11), (13) is a horizontal mounting frame that integrally connects the rear end to the rear mounting frame (12), and (14) is a horizontal mounting frame. (13) A front mounting frame integrally connected to the front end side. Each of the frames (12), (13), and (14) is formed in a gate shape in a side view, and is fixed to the lower surface of the power transmission case (6). The rear mounting frame (12) is erected on the base stand (15) via the rear mounting base (16), and the front mounting frame (14) is mounted on the front end side of the chassis (4) via the front mounting base (17). ), And portal-shaped frames (12), (13), (14) are symmetrically mounted on both sides of the hood (18) covering the engine (5).

Further, a base end of the lift arm (11) is connected to and supported by an upper end of the front mounting frame (12) via a rotation fulcrum pin (19), and is provided between the frame (12) and the lift arm (11). Pin (21) (2) between the fixed locking plate (20)
The loader lifting cylinder (23) is interposed via 2), and the lift arm (1
1) is configured to be raised and lowered as appropriate.

A dump cylinder (28) and a dump arm (25) are attached to fixed brackets (24) (25), which are fixed mounting plates between the middle and front ends of the lift arm (11), via respective swing pins (26) (27). 29) Support each base end of these cylinders (2
8) and the tip of the arm (29) are connected to each other via a pin (30), and the tip of the arm (29) is attached to the pin (31) and the upper hook arm (3) at the upper rear end of the bucket (10).
2) and linked via a dump link (33). A pin (34) and a lower hook arm (3) are attached to the lower end of the bucket (10) at the front end of the lift arm (11).
5), and the tilt of the bucket (10) is appropriately changed by the expansion and contraction operation of the dump cylinder (28).

Furthermore, a notch (37) is formed diagonally upward at the middle front side of the rear mounting base (16) via a hook arm (36), and a horizontal opening notch (38) is formed at the front upper end of the rear mounting base (16). At the same time, a pair of leg plates (39) and (39) are integrally formed on the lower end side of the rear mounting frame (12), and a rear view C-shaped open leg portion (40) (40) having a wide rear and lower portion is formed. Footboard (3
9) (39) While forming at the lower end, each notch (37) (38)
Attach the locking pins (41) and (42) to the legs (39) (3
9) Horizontally fix them together.

Then, after the pin (41) is engaged with the notch (37) by the guide of the hook arm (36), the rear mounting frame (12) is displaced around the pin (41), and the pin (41) is inserted into the notch (38). The upper and lower rear mounting frames (43) are connected to the left and right mounting bases (16) (16) at the rear of the tractor (1) from the front upper side by a linking pipe (43). 12) (12) is configured to be engaged and fixed so as to be tiltable and disengageable only forward.

Further, a holding rod (44), which is a lock pin, is suspended between the lower ends of the left and right front mounting frames (14) and (14), and a square cylindrical holding box (45) is mounted on the front mounting base (17). The rod (44) is fixed to the box (45) so that the support shaft (46) is detachably engaged with the box (45). The front mounting frame (14) is configured to be engaged and fixed to the table (17) from below.

Further, as shown in FIGS. 2, 5 and 6, a controller (4) for controlling the operation of the cylinders (23) and (28) is provided.
7) is detachably attached to the right side of the driver's seat (7) via a support arm (48). A neutral return type manual lever (49) that can swing in eight directions and a lift arm to a set height A neutral return type one-touch lever (50) that automatically raises and lowers (11), a variable resistor type lift arm lower limit setting volume (51) that sets the automatic lowering height of the lift arm (11), and a lift arm (11) High-speed and low-speed cylinder speed setting switch (52) for setting the vertical speed
(53), a one-touch changeover switch (54) for turning on / off the automatic raising / lowering control of the one-touch lever (50), and a horizontal plane which makes the bucket (10) parallel to the tractor (1) near the ground by lowering the lift arm (11). A horizontal grounding switch (55) that turns on and off the grounding control, and a floating switch (5) that lowers the lift arm (11) freely by its own weight
6), a bucket setting volume (57) for adjusting the horizontal (parallel) state of the bucket (10) with respect to the tractor (1) body, and a controller detachable switch for detecting attachment / detachment of the controller (47) to / from the support arm (48). (Five
8) is arranged on the controller (47), and a lift arm potentiometer (59) for lifting and lowering which is linked with the forward and backward tilting of the manual lever (49);
The controller (47) incorporates a bucket potentiometer (60) for dumping and scooping that is linked with the tilting right and left of 9), and a raising / lowering switch (61) that is switched by the one-touch lever (50).

Further, as shown in FIG. 1, a loader control circuit (62) constituted by a microcomputer is provided in the controller (47), and each volume (51) (57) and each switch (5
2) Connect (53) (54) (55) (56) (58) (61) and each of the potentiometers (59) (60) to the circuit (62), and supply a drive power to the circuit (62). The power switch (63) to be applied is provided, and the key switch (6
4) Connect the switch (63) to the battery (67) via a fuse (65) and a relay (66).

A variable stroke capacitance lift arm position sensor (68), which is attached in parallel to the loader lift cylinder (23) via each pin (21) (22), and a dump cylinder via each pin (26) (30) (28) and a variable stroke capacitance bucket position sensor (69) mounted in parallel with
Each of the sensors (68) and (69) connected to the circuit (62) detects the supporting height and attitude of the lift arm (11) and the bucket (10), and detects the loader elevating cylinder (23).
Lifting arm solenoid that extends and retracts the electromagnetic solenoid (7
0) and a lift arm lowering electromagnetic solenoid (71), a bucket dump electromagnetic solenoid (72) and a bucket scooping electromagnetic solenoid (73) for extending and retracting the dump cylinder (28), and each of the solenoids (70) to (73) is provided. The output is connected to the control circuit (62).

In addition, a light emitting diode (74) for displaying runaway of the control circuit (62) by turning off the light is provided.
(57) and each potentiometer (59) (60) and each sensor (6
8) The abnormal input of (69) is displayed by turning on the light emitting diode (74), and the normal state of each part is displayed by blinking of the light emitting diode (74).

Further, as shown in FIG.
3) Elevating control valve (75) for controlling operation of dump cylinder (28) and dump scooping valve (76) for controlling operation of dump cylinder (28). Hydraulic pump (77) through each valve (75) (76)
To supply high-pressure oil to each cylinder (23) (28), and to operate each valve (75) (76) by switching the pilot operation cylinders (78) (79) and each solenoid (70) (7
1) Pilot operation valves (80) (81) (82) for raising and lowering, and for dumping and scooping to operate each operation cylinder (78) (79) by switching control by (72) (73)
(83), and each of the operation valves (80) to (83) is controlled by pulse control for operating each of the solenoids (70) to (73) by the pulse signal output of the loader control circuit (62).
, Each operating cylinder (78) (79) is operated to switch each control valve (75) (76), and each cylinder (23)
The hydraulic flow rate for operating (28) is adjusted, the operating speed of each cylinder (23) (28) is controlled by adjusting the hydraulic flow rate, and the operation of each solenoid (70) is performed by swinging the manual lever (66) in eight directions. ) To (73), the descending operation, the dumping operation while descending, the dumping operation performed at a constant height, the dumping operation while ascending, the ascending operation, and the scooping while ascending. An operation, a scooping operation performed at a fixed height, and a scooping operation while descending are performed.

FIG. 8 is a flow chart showing the check operation, and the present embodiment is configured as described above. When the power switch (63) is turned on and the loader control circuit (62) goes out of control, light emission occurs. The diode (74) is turned off, and if there is an abnormality in the check in FIGS. 9 to 14, the light emitting diode (74) is turned on, and when the respective parts are in a normal state, the light emitting diode (74) blinks. To make
The abnormal time and the normal time are indicated by the light emitting diode (74).

FIG. 9 is a flowchart showing a bucket tension (60) check. When the input from the bucket position (60) is larger or smaller than the dump or scooping control range, the light emitting diode (74) is turned on. The abnormal input is displayed, and the manual operation of the bucket (10) based on the input of the bucket potentiometer (60) operated by the manual lever (49) is prohibited.

FIG. 10 is a flowchart showing the check of the bucket position sensor (69).
When the input from 9) is too large or too small from the dumping or scooping control range, the light emitting diode (74) is turned on to indicate an abnormal input, and the input from the bucket position sensor (69) is displayed as shown in FIG. The grounding operation and the parallel operation shown in FIG. 19 are each prohibited, and the bucket (10) is automatically returned until the input of the bucket position sensor (69) is within the proper input range by operating the dump cylinder (28). The prohibitions are released.

FIG. 11 is a flow chart showing the check of the lift arm potentiometer (59). When the input from the lift arm potentiometer (59) is larger or smaller than the control range of raising or lowering, the light emitting diode (74) is turned on. An abnormal input is displayed, and the manual operation of the lift arm (11) based on the input of the lift arm potentiometer (59) operated by the manual lever (49) is prohibited.

FIG. 12 is a flow chart showing the check of the lift arm position sensor (68). When the input from the lift arm position sensor (68) is larger or smaller than the range of the ascending or descending control, the light emitting diode (74) is turned on. To display the abnormal input and the lift arm position sensor (6
The input from 8), the horizontal grounding operation shown in Fig. 18, the parallel operation shown in Fig. 19, and the one-touch operation shown in Fig. 17 are prohibited. The lift arm position is activated by operating the loader lifting cylinder (23). The lift arm (11) is automatically returned until the sensor (68) input is within the proper input range, and the prohibitions are released.

Fig. 13 shows the lift arm lower limit setting volume (5
1) This is a flowchart showing the check. When the input from the lift arm lower limit setting volume (51) is larger or smaller than the raising or lowering control range, the light emitting diode (74) is turned on to display the abnormal input and the lift is displayed. The intermediate value between the minimum set value and the maximum set value of the arm lower limit setting volume (51) is automatically set as the input of the volume (51), and the output of the volume (51) is fixed to neutral, and the lift arm (11) is returned to the middle position between the neutral position and the lowest position of the lifting range, and is supported.

FIG. 14 is a flowchart showing the check of the bucket setting volume (57). When the input from the bucket setting volume (57) is larger or smaller than the dump or scooping control range, the light emitting diode (74) is turned on. An abnormal input is displayed, and an intermediate value between the minimum set value and the maximum set value of the bucket setting volume (57) is automatically set as the input of the volume (57), and the output of the volume (57) is fixed to neutral. The bucket (1
0) is returned to the dump posture and supported.

FIG. 15 is a flowchart showing the manual operation of the bucket (10). When the manual lever (49) is dumped or scooped, a bucket potentiometer (60) input interlocked with the manual lever (49) is inputted and the neutral position of the neutral position is set. The duty ratio of the dump or scooping control pulse signal for driving the solenoids (72) and (73) is changed in proportion to the difference between the duty ratio and the dump cylinder (2
8) Speed control of the manual lever (49). The greater the operation amount of the manual lever (49), the higher the speed of the cylinder (28) operation. Immediately before the bucket (10) stop position where the input matches the bucket position sensor (69) input, a cushioning operation that gradually reduces the driving speed of the cylinder (28) is performed by pulse control, and the bucket (10) stops at a predetermined position. Let it.

FIG. 16 is a flowchart showing the manual operation of the lift arm (11). When the manual lever (49) is lowered or raised, the lift arm potentiometer (59) input interlocking with the manual lever (49) and the neutral position of the lift arm potentiometer (59) are set. Change the duty ratio of the lowering or raising control pulse signal that drives the solenoids (70) and (71) in proportion to the difference between the position value and the speed control of the loader lifting cylinder (23) by adjusting the hydraulic flow rate by pulse signal control. As the operation amount of the manual lever (49) increases, the lowering or raising operation of the lift arm (11) is performed by pulse control that speeds up the operation of the cylinder (23). Cushion operation to gradually reduce the driving speed of the cylinder (23) just before the stop position of the lift arm (11) where the input of the arm position sensor (68) matches Performed by pulse control, to stop the lift arm (11) at a predetermined height position.

Further, FIG. 17 is a flowchart showing a one-touch operation for automatically raising and lowering the lift arm (11) to the set height. When the controller detachment switch (58) is turned on and the attachment of the controller (47) is confirmed, one-touch switching is performed. When the switch (54) is turned on and the one-touch lever (50) is raised and lowered to switch the lifting / lowering switch (61) to the up or down side, the lift arm (11)
The lift is automatically raised or lowered by lowering the one-touch lever (50) to the lower limit position of the lift arm lower limit setting volume (51), which can be set to any desired height, by adjusting the pulse control speed. Arm (11)
The lifting arm (11) is moved up and down while the lifting arm (11) is moved to a fixed lifting position at a predetermined fixed height by raising the one-touch lever (50) by adjusting the speed of pulse control.
The lift arm (11) is stopped while the cushioning operation for gradually decelerating before a predetermined stop position is performed by pulse control, and the lower limit setting position of the volume (51) is fixed or fixed. The lift arm (11) is automatically raised and lowered to a lifting position at a certain height to support it.
When the switches (54) and (58) are turned off, the one-touch operation is immediately stopped and the output is stopped. When the power switch (63) is turned on from off, the condition of the one-touch operation is satisfied. Even if the operation is performed, the one-touch operation is not performed. In this case, the operation condition is not satisfied, and the one-touch operation is performed by satisfying the operation condition again.

As is clear from the above, the loader lifting cylinder (23) for lifting and lowering the lift arm (11) mounted on the tractor (1), and the bucket (10) provided on the lift arm (11)
And a sensor for detecting the positions of the lift arm (11) and the bucket (10) and the lift arm position and the bucket position (68) (6).
9) and a controller (47) for attaching a manual lever (49) for operating the cylinders (23) and (28) and a one-touch lever (50) which is an automatic lever for automatically moving the lift arm (11) up and down to a set height. In the lifting work machine to be provided, a one-touch changeover switch (54) for turning on and off the automatic raising and lowering of the one-touch lever (50) and a controller attaching / detaching switch (58) for detecting attachment / detachment of the controller (47) to / from the tractor (1). (Four
7), a controller (47) is mounted on the tractor (1), and automatic control of the one-touch lever (50) is performed by switching the changeover switch (54) from off to on. The tractor (1) confirms the attachment of the controller (47) to the machine by the detachable switch (58), and the lift arm (11) of the one-touch lever (50) automatically moves up and down by switching the changeover switch (54) on and off. Even if the changeover switch (54) is turned on due to an erroneous operation when the controller (47) is removed from the tractor (1), the one-touch lever (50) is prevented from automatically moving up and down by the detachable switch (58). At the same time, when the controller (47) is mounted on the tractor (1) with the changeover switch (54) turned on, the condition is satisfied again by turning the changeover switch (54) off and on, even if the detachment switch (58) is turned on. Prevents the one-touch lever (50) from automatically moving up and down until operation, and allows the operator to recognize the one-touch lever (50) Automatic lifting to perform the tractor (1) simplified and the lift arm (11) of the driving operation achieving such improvement in workability with lifting.

Further, FIG. 18 is a flowchart showing a horizontal grounding operation for supporting the bucket (10) in a predetermined posture (parallel) with respect to the tractor (1), and the controller grounding switch (58) is turned on and the horizontal grounding switch (55). ) Is turned on, the lift arm (11) is lowered by the manual operation shown in FIG. 16 or the one-touch operation shown in FIG.
In the state where the bucket (10) in the figure has not been manually operated,
The user inputs a set value of a bucket setting volume (57) for adjusting the horizontal (parallel) state of the bucket (10) with respect to the aircraft, and inputs the volume (57) input and each sensor (68) (6).
9) Based on the input, the bucket (10) is controlled to the horizontal grounding posture in cooperation with the lowering of the lift arm (11), and the tractor (1) is lowered while supporting the bucket (10) in a constant posture relative to the body. Operate the dump cylinder (28) at the higher of the control speed in proportion to the lowering speed of the lift arm (11) or the ideal step drive speed, and set the calculation speed based on the speed of the lift arm (11). The bucket (10) is moved to the horizontal contact position at the higher speed, and even if the lift arm (10) descends and reaches a predetermined value,
When the bucket (10) is positioned on the scooping side and is not in the horizontal contact position, the lowering of the lift arm (11) is stopped, the control of the horizontal contact position of the bucket (10) is continued, and the horizontal position of the bucket (10) is maintained. When the bucket (10) is horizontal (parallel) with respect to the tractor (1), only the grounding operation is performed.
The lowering operation of the lift arm (11) is started by the manual lowering operation shown in the figure, and the bucket (10) is lowered while the lift arm (11) is lowered.
Perform horizontal landing attitude control and stop the lift arm (11) at a predetermined position by a cushion operation that gradually decelerates,
The bucket (10) is supported in a horizontal position. The horizontal grounding was stopped by the manual bucket operation shown in FIG. 15, and the horizontal grounding was resumed by releasing the manual operation, and the lift arm (11) shown in FIG. 16 was manually lifted during the horizontal grounding operation. At this time, the horizontal grounding operation is stopped, and the control of the parallel operation shown in FIG. 19 is performed. In addition, each switch (55) (58)
When either of them is turned off, the horizontal landing operation is stopped after controlling the bucket (10) to the neutral posture.

Further, FIG. 19 is a flow chart showing a parallel operation for raising and lowering the bucket (10) in a substantially constant posture. When the controller attaching / detaching switch (58) is turned on, the manual operation shown in FIG. 16 or the one-touch operation shown in FIG. The position of the bucket (10) with respect to the tractor (1) immediately before the lift arm (11) goes up or down in a state where the bucket (10) shown in FIG. 15 is not manually operated by raising and lowering the arm (11). , Or the bucket (10) is kept in the position of one of the buckets (10) immediately after stopping when the bucket (10) is operated while the lift arm (11) is moving up and down. The speed of the dump cylinder (28) that operates the bucket (10) is changed by pulse control in proportion to the elevating speed, and the scooping speed is increased compared to the dump speed of the bucket (10). The cushion operation for decelerating people to stop the lift arm (11) in position. Note that the parallel operation is stopped by the bucket manual operation shown in FIG. 15, and the parallel operation is resumed by the manual release, and when the switch (58) is turned off during the parallel operation, the bucket (10) is set to the ideal position. The parallel motion is stopped after being set to the position and supported in the neutral posture.

FIG. 20 is a flowchart showing a floating operation in which the lift arm (11) is freely lowered by its own weight. The floating switch (56) is turned on, and the lift arm potentiometer (59) is operated by the manual lever (49). When the lift arm (11) is lowered by operating the solenoid (71) continuously, the lift control valve (75)
Is continuously driven to the descending side, and the horizontal grounding operation shown in FIG.
In the state where the parallel operation shown in FIG. 19 is stopped and the bucket (10) automatic control is stopped, the lift arm 11 is lowered by the continuous operation control. When the floating switch (56) is turned off, The horizontal grounding operation and the parallel operation are started based on the inputs of the sensors (68) and (69).

FIG. 21 is a flow chart showing the restriction of the continuous operation for restricting the operation of each of the solenoids (70) to (73) to prevent the power supply circuits from being thermally destroyed. Are continuously performed, and when a predetermined time has elapsed, the control output of the lift arm (11) and the bucket (10) is stopped, and each of the solenoids (70) to (7) is stopped.
Turn off the power supply circuit of 3) and loader control circuit (6
2) After resetting all, return to the first check operation and restart the control by continuous operation (pulse signal output off). When a certain time has elapsed, each solenoid (70) to (73) is operated by a pulse signal. The control speeds of the cylinders (23) and (28) are adjusted to perform the operations shown in FIGS. 15 to 20.

[Effects of the Invention] As is clear from the above embodiments, the present invention provides a loader lifting cylinder (23) for lifting and lowering a lift arm (11) mounted on a tractor (1), and a bucket (23) provided on the lift arm (11). 10) a dump cylinder (28) for operating the same, sensors (68) and (69) for detecting the positions of the lift arm (11) and the bucket (10), and a manual operating the cylinders (23) and (28). A changeover switch for turning on and off the automatic lifting and lowering of the automatic lever (50) in a lifting working machine provided with a controller (47) for mounting an automatic lever (50) for automatically raising and lowering a lever (49) and a lift arm (11) to a set height. (54) and a detachable switch (58) for detecting the attachment / detachment of the controller (47) to / from the tractor (1) are provided in the controller (47). ) Is mounted, and the automatic control of the automatic lever (50) is performed by switching the changeover switch (54) from off to on. The attachment of the attachment / detachment switch (58) is confirmed by the attachment / detachment switch (58), and the automatic lever (5
0), the lift arm (11) can be automatically raised and lowered. Therefore, even if the changeover switch (54) is turned on due to an erroneous operation when the controller (47) is removed from the tractor (1), the detachable switch (58) ) By automatic lever (5
0) can be prevented from automatically moving up and down, and the changeover switch (5
4) When the controller (47) is mounted on the tractor (1) with the switch turned on, even if the detachable switch (58) is turned on, the automatic lever ( The automatic lifting and lowering of the tractor (1) can be prevented, and the automatic lever (50) can be automatically raised and lowered by the on / off operation of the changeover switch (54). The arm (11) can easily improve the workability associated with elevating and lowering.

[Brief description of the drawings]

FIG. 1 is a loader control circuit diagram showing an embodiment of the present invention, FIG. 2 is an overall side view, FIG. 3 is a side view of a front loader, FIG. 4 is a plan view of the same, and FIG. FIG. 6 is a front view, FIG. 6 is a side view, FIG. 7 is a loader hydraulic circuit diagram, and FIGS. 8 to 21 are flowcharts of the loader operation. (1) Tractor (10) Bucket (11) Lift arm (23) Loader lift cylinder (28) Dump cylinder (47) Controller (49) Manual lever (50) …… One-touch lever (automatic lever) (54)… One-touch selector switch (58)… Controller detachable switch (68)… lift arm position sensor (69)… bucket position sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-97727 (JP, A) JP-A-63-103129 (JP, A) JP-A-62-189221 (JP, A) JP-A-62-189221 244930 (JP, A) Fully open 58-99349 (JP, U) Fully open 3-25641 (JP, U) Fully open 61-10366 (JP, U) Really open 51-40004 (JP, U) (58) Field surveyed (Int.Cl. ⁶ , DB name) E02F 9/20 E02F 9/22 E02F 3/43

Claims (1)

(57) [Claims] A lift cylinder (23) for raising and lowering a lift arm (11) mounted on a tractor (1), and a dump cylinder (28) for operating a bucket (10) provided on the lift arm (11). A sensor (68) for detecting the position of the lift arm (11) and the bucket (10).
(69) Lifting work to provide a manual lever (49) for operating the cylinders (23) and (28) and a controller (47) for mounting an automatic lever (50) for automatically raising and lowering the lift arm (11) to a set height Switch (54) for turning on and off the automatic lifting and lowering of the automatic lever (50) in the machine
And a detachable switch (58) for detecting the attachment and detachment of the controller (47) to and from the tractor (1).
7), a controller (47) is mounted on the tractor (1), and the automatic control of the automatic lever (50) is performed by switching the switch (54) from off to on. A lifting work machine characterized by the following.