JP2002291304A - Device for lifting and lowering implement in working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the lowest position of an implement by a simple operation and to prevent unexpected lifting or lowering just after the on-operation of a power source in a working vehicle for lifting and lowering the implement by the operation of a position lever. SOLUTION: A safety mode is practiced just after the on-operation of the power source, and a lift arm is not moved even if the lift arm is positioned at the side lower than the lowering-controlling position. When an operator moves the position lever to coincide the position of the lift arm therewith, the safety mode is released to enable the lift arm to be turned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work machine lift control device for a work vehicle, and more particularly to a work machine lift control device for electrically restricting the lowest position of a work machine.

[0002]

2. Description of the Related Art
A work machine is connected to the body of the work vehicle via a link mechanism,
There is known an apparatus in which a lift arm is rotated by driving an actuator to move a work machine up and down. This type of work vehicle has a position lever near the driver's seat,
The height of the working machine is changed by driving the actuator by operating the position lever. Also, when working while raising and lowering the work implement by operating the position lever, to prevent the work implement from going deep into the soil,
There is also known one provided with a means for regulating the lowermost position of the work machine.

Conventionally, the lowering of the working machine is restricted by restricting the operation of the position lever in the lowering direction by a stopper piece or the like, and by directly locking the lowering operation of the link mechanism by the stopper piece or the like. However, each time the operator has to manually set the stopper pieces, the operability is not good. Further, when the lowering position of the work implement is electrically regulated, in a setting in which the operation of the lowering restriction setting device of the work implement is prioritized over the operation of the position lever, the lift arm is higher than the lowermost restriction position. If the lift arm starts moving suddenly immediately after the power is turned on, the work equipment may be moved up and down unexpectedly, which is dangerous.

Therefore, in a working vehicle in which the working machine is raised and lowered by operating the position lever, the lowering position of the working machine is regulated by a simple operation, and the working machine is prevented from being accidentally raised and lowered immediately after the power is turned on. Therefore, a technical problem to be solved arises, and an object of the present invention is to solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and a work machine 14 connected to a vehicle body is moved up and down by the rotation of a lift arm 19. In the working vehicle 10 provided with the position lever 54 for changing the height of the lift lever 19, a lowering restriction setting device 60 for restricting the lowering position of the lift arm 19 is provided near the driver's seat 47, and the setting position of the position lever 54 When the restriction position of the lowering restriction setting device 60 is changed to the raising side, the lift arm 19 is driven with priority over the set value of the position lever 54, and immediately after the power is turned on, the lift arm 19 is lowered. Even if it is below the regulation position of the regulation setter 60, the rotation of the lift arm 19 is restrained, and after the power is turned on, the position lever 54 is set. When the position substantially coincides with the position of the lift arm 19, the work machine lifting / lowering control device of the work vehicle provided with the control means 50 for rotating the lift arm 19 to the lowering restriction position, and the work machine 14 connected to the vehicle body Is moved up and down by the rotation of the lift arm 19 and the working machine 1
In the work vehicle 10 provided with the position lever 54 for changing the height of the lift 4, the lift position setting device 57 for setting the lift position of the lift arm 19 to a position near the driver's seat 47 and the lower position of the lift arm 19 And a control range that can be set by the raising position setting device 57 and a control range that can be set by the lowering setting device 60. A control means 5 for giving priority to the setting of the raising position setting device 57 when they overlap.
0 is provided.

[0006]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a tractor 10 as an example of a work vehicle.
1 is mounted and covered with a hood 12, and a rotary working machine 14 is connected to a rear portion of the body via a link mechanism 13. The link mechanism 13 includes a top link 15 and left and right lower links 16, 16. The link mechanism 13 drives a lift cylinder 18 provided on an upper portion of the transmission case 17 to rotate the lift arms 19, 19, thereby causing the left and right lift rods to move. The lower links 16, 16 move up and down via 20, 20, respectively. Thus, the rotary working machine 14 moves up and down around the tip of the lower links 16 and 16 as the center of rotation.

A lift arm angle sensor 21 is provided at the rotation base of the lift arm 19 as means for detecting the elevation of the work machine. The lift arm angle sensor 21 detects the rotation angle of the lift arm 19. Is detected, and the elevation of the rotary working machine 14 is calculated by the controller 50 described later. The main cover 22 of the rotary working machine 14
The rear cover 23 is attached to the rear end of the
The rotation angle of the rear cover 23 is detected by a rear cover sensor 24, and the rotary work machine 14 is
Calculate the amount of tillage.

FIG. 2 shows a power transmission path, and FIG. 3 is a block diagram of a control system. In FIGS. 1 to 3, the power of the engine 11 is transmitted through the main clutch 30 to the transmission case 1.
7, the forward / reverse switching device 31 of the traveling system and the PTO
It is input to the PTO clutch 32 of the system. The traveling system power is transmitted from the forward / reverse switching device 31 to the main transmission device 33 and the auxiliary transmission device 3.
4 is transmitted. By pressing a button provided on the shift lever 26, the shift cylinder 2 serving as an actuator is pressed.
7 and 28 are driven to switch the main transmission 33, and the manual operation of the shift lever 26 moves the shifter to switch the subtransmission 34.

The main transmission 33 and the auxiliary transmission 3
The traveling system power decelerated in a plurality of stages at 4 is transmitted from the rear differential device 35 to the left and right output shafts 36, 36, and further transmitted to the rear wheels 38 after being further decelerated by the reduction mechanism 37. A brake device 40 is attached to the outer end of the output shaft 36, and the brake plate of the brake device 40 is pressed by driving the brake cylinder 41, so that the rotation of the left and right output shafts 36, 36 is separately performed. It is formed so that it can be braked.

On the other hand, the power branched forward from the auxiliary transmission 34 is transmitted to the left and right output shafts 45, 45 from a front differential 44 via a four-wheel drive switching device 43.
, The front wheel 46 is driven at a constant speed or a double speed with respect to the peripheral speed of the rear wheel 38. In addition, a steering handle 48, which is a steering operation unit of the fuselage, is provided in front of the driver's seat 47. The rotation operation of the steering handle 48 is transmitted to a steering device 49, and the front wheels 46 are turned in accordance with the rotation operation of the steering handle 48. Turn left and right. The steering operation amount of the front wheel 46 is detected by a front wheel turning angle sensor 51.

Further, in the vicinity of the steering handle 48, a work implement elevating lever 52 is provided as a switch-type work implement elevating operation means different from a position lever 54 to be described later, and the forward / reverse switching device 31 is moved forward or backward. A forward / reverse switching lever 53 for switching is provided. By operating the work machine lifting lever 52, the rotary work machine 14 is continuously raised from the work position to a predetermined height, or the rotary work machine 14 is continuously lowered from the predetermined height to the work position. Driver's seat 4
7, the speed change lever 26 and the position lever 5
The height of the rotary working machine 14 is changed by the position lever 54.

As shown in FIG. 4, various levers such as the speed change lever 26 and the position lever 54, a cultivation depth adjustment dial 55 and a PTO
Various dials and switches, such as an on / off switch 56, are provided. Also, the highest position adjustment dial 57
Infrequently used dials, such as the left and right tilt adjustment dial 58 and the like, are provided at positions covered by the cover 59.
The raising position adjusting dial 57 is a raising position setting device that sets the raising position of the lift arm 19 (that is, the raising position of the rotary work machine 14).
By turning the dial 7 clockwise, the highest position can be set high, and by turning the maximum position adjustment dial 57 counterclockwise, the highest position can be set low. Then, the controller 50 is controlled according to the set position of the highest position adjustment dial 57.
Monitors the detection signal of the lift arm angle sensor 21 and regulates the output signal to the ascending solenoid 61 so as not to rotate the lift arm 19 beyond a predetermined height.

At this time, at a position near the position lever 54 and on the lower side of the work implement of the lever guide, a lowering restriction setting device for restricting the lowering position of the lift arm 19 (that is, the lowering position of the rotary operating machine 14). The lowering restriction dial 60 is provided. The lower limit regulation dial 60
Is a rotary working machine 1 using the position lever 54.
5, the lowermost position can be set higher by turning the lowermost position restricting dial 60 clockwise, as shown in FIG. By turning in the direction, the lowermost position can be set lower. Then, while the controller 50 monitors the detection signal of the lift arm angle sensor 21 according to the set position of the lowering restriction dial 60, the controller 50 controls the lowering solenoid 62 so as not to rotate the lift arm 19 below a predetermined height. Regulate the output signal. When the lowering restriction dial 60 is turned to the maximum in the counterclockwise direction, the position becomes the "off" position. In that case, the lowering restriction control described later is turned off, and the lowering restriction not intended by the operator is performed. Can be prevented.

The setting operation of the lowering restriction dial 60 has priority over the lowering operation of the position lever 54.
For example, as shown in FIG. 6, when the lowermost position (the position shown by the two-dot chain line) is set in advance by the lowering restriction dial 60, the uppermost position (shown by the solid line) where the lift arm 19 can rotate. When the lowering operation of the position lever 54 is performed from the state of (), the lift arm 19 is rotated downward and the work machine is lowered, but the lift arm 19 is moved to the set lowermost position (). Stops rotating. Then, even if the lowering operation of the position lever 54 is continued, the lift arm 19 does not rotate below its height.

As described above, since the controller 50 electrically controls the output signal to the descending solenoid 62, the structure is simplified, the cost is reduced, and the lowermost position can be set accurately and the operability is improved. It will be good. In addition, since the setting operation of the lowering restriction dial 60 is given priority over the lowering operation of the position lever 54,
In a state where the lift arm 19 is at the (lowest) position set as described above, the operator operates the lowering restriction dial 6.
0, the controller 5 is operated according to the rotation operation.
Ascending solenoid 61 or descending solenoid 62 from 0
, And the lift arm 19 moves up and down. That is, when the position lever 54 is at the set lowermost position (the position), the height of the working machine can be freely changed by operating the lowering restriction dial 60. Operability is better than that, and fine adjustment is possible.

The restriction range of the lowermost position by the lowermost restriction dial 60 is defined by the lowermost position (position indicated by a dotted line) at which the lift arm 19 can rotate and the uppermost position (position) indicated by the dotted line. It is assumed that the lowermost position can be set in a range below the middle position of the lift arm (the position indicated by the dashed line), that is, in the range from the position to the position in FIG. In this way, by limiting the range of rotation of the lift arm 19 to the range of actual use, instead of the entire range, the resolution of the lowering-restriction dial 60 with respect to the rotational operation amount is increased, and fine adjustment is facilitated.

In the case where the lowermost position can be set within a range from a position (a position) slightly lower than the lowermost position at which the lift arm 19 is rotatable,
The setting range of the lowermost restriction dial 60 is expanded to a position below the control range of the position lever 54, and even if there is no “off” position of the lowermost restriction dial 60 described in FIG. It is possible to turn off the control of the lowering regulation, thereby preventing the lowering regulation unintended by the operator.

When the position of the position lever 54 is above the set lowermost position, the flow rate setting signal corresponding to the difference between the position of the lift arm 19 and the lowermost position is sent to the controller 50. To the ascending solenoid 61 or the descending solenoid 62. On the other hand, when the position of the position lever 54 is below the set lowermost position, the flow rate setting signal corresponding to the difference between the position of the lift arm 19 and the position of the position lever 54 is raised from the controller 50. Output to the solenoid 61 or the descending solenoid 62. That is, by changing the flow rate setting when the target value is far and near, the lift arm 19
Is controlled to an appropriate speed.

Here, as shown in FIG. 7, the control range which can be set by the uppermost position setting dial 57 is from the uppermost position (position) of the lift arm to the lowermost position (position) of the uppermost setting. If it is within the range, the control range that can be set with the lowermost restriction dial 60 is set to a range from the above-described position to the upper limit position of the lowermost setting, and can be set with the uppermost position setting dial 57. The control range (the range from) and the control range (the range from) that can be set by the lowermost restriction dial 60 are configured to overlap. This is to increase the degree of freedom of the setting width in such a case because there is a case where it is desired to set the raising position considerably lower or a case where the lowering restriction position is to be set higher depending on the working machine.

If the control range (the range from) settable with the maximum raising position setting dial 57 and the control range (the range from) settable with the lowermost restriction dial 60 are overlapped, the raising position is set. Control to give priority to settings. That is, when the uppermost position setting dial 57 is rotated counterclockwise to lower the uppermost position to the lower side, the uppermost position is set at the lower limit position (which can be set) regardless of the set position of the lowermost restriction position. Position). However, when the lowermost restricting dial 60 is rotated clockwise to raise the lowermost restricting position to a higher position, if the uppermost position set by the uppermost position setting dial 57 is between and, The lift arm 19 stops at this highest position. This is because the work implement does not rise in the lowered position setting, but if the raised position setting is higher than intended, it may interfere with the cabin when the work equipment is raised. Priority is given to the raising position setting in order to prevent the above.

FIG. 8 is a flowchart of the work machine elevating control immediately after the power is turned on. In order to execute the safety mode immediately after the power is turned on, the lift arm is set at a position lower than the lowermost restricting position set by the lowermost restricting dial 60. Even if the position 19 is on the lower side, the control signal is not output from the controller 50 to the ascending solenoid 61 or the descending solenoid 62, and the rotation of the lift arm 19 is suppressed. Then, the operator operates the position lever 54,
When the position of the position lever 54 and the position of the lift arm 19 are matched, the safety mode is released.

After the safety mode is released, if the position of the position lever 54 is raised when the lift arm 19 is below the lowermost regulation position, a control signal is output from the controller 50 to the lift solenoid 61. Then, the lift arm 19 is rotated upward. On the other hand, when the lowering operation of the position lever 54 is performed,
The control signal is not output from the controller 50 to the descending solenoid 62, and the downward rotation of the lift arm 19 is suppressed. This is because the lift arm 19 does not fall below the current position and only the lifting operation is reliably performed. Further, the lift arm 19 is configured to move up in response to a request for increasing output of each control such as the rear cover automatic control and the draft control.

Although the rotary working machine has been described as the working machine in the present embodiment, the same effect can be obtained in a draft control using a plow working machine, a planting device for a rice transplanter, and the like. Thus, 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 one.

[0024]

As described in detail in the above embodiment, the invention according to claim 1 is in the safety mode when the power is turned on, so that the lift arm is located below the lowering restriction position. The lift arm does not move. When the operator moves the position lever to match the position of the lift arm, the safety mode is released, and the lift arm can be rotated. Therefore, it is possible to prevent the working machine from being accidentally raised and lowered immediately after the power is turned on, and to release the safety mode without feeling uncomfortable with the operation of the operator.

Further, when the control range that can be set with the highest position setting dial overlaps with the control range that can be set with the lowest position control dial, the setting of the raising position setting device is performed. Since the priority is given, the highest position is not set at a height not intended by the operator, and it is possible to prevent the vehicle body and the machine from being damaged due to interference with the cabin when the work machine is raised.

[Brief description of the drawings]

 The figure shows an embodiment of the present invention.

FIG. 1 is a side view of a tractor to which a rotary working machine is connected.

FIG. 2 is a power transmission path diagram.

FIG. 3 is a block diagram of a control system.

FIG. 4A is a plan view of levers and dials provided near a driver's seat. (B) Side view of levers and dials provided near the driver's seat.

FIG. 5 is an enlarged view showing a lower limit regulation dial setting range.

FIG. 6 is an explanatory diagram for explaining a lowermost position of a lift arm.

FIG. 7 is an explanatory diagram for explaining overlapping control ranges.

FIG. 8 is a flowchart showing a control procedure.

[Explanation of symbols]

 Reference Signs List 10 Tractor 14 Rotary work machine 19 Lift arm 47 Driver's seat 50 Controller 54 Position lever 57 Top-up position adjustment dial 60 Top-down regulation dial

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B304 KA16 LA02 LA06 LB05 LB15 MA03 MB02 MC12 MC13 PA01 QA08 QA11 QA22 QB13 RA08 RA27

Claims (2)

[Claims] A work machine connected to a vehicle body is moved up and down by the rotation of a lift arm, and the work vehicle is provided with a position lever for changing the height of the work machine. In the vicinity of the seat 47, there is provided a lowering setting device 60 for restricting the lowering position of the lift arm 19. When the restricting position of the lowering setting device 60 is changed from the setting position of the position lever 54 to the raising position, the position lever is set. The lift arm 19 is driven with priority over the set value of 54, and immediately after the power is turned on, even if the lift arm 19 is below the restriction position of the lowering restriction setter 60, the rotation of the lift arm 19 is performed. When the set position of the position lever 54 substantially coincides with the position of the lift arm 19 after the power is turned on,
A work machine lifting / lowering control device for a work vehicle, comprising control means 50 for rotating the lift arm 19 to the lowering restriction position. 2. The operation of the work vehicle 10 having a position lever 54 for moving the work machine 14 connected to the vehicle body up and down by the rotation of the lift arm 19 and changing the height of the work machine 14 A raising position setting device 57 for setting the raising position of the lift arm 19 at a position near the seat 47 and a lowering restriction setting device 60 for restricting the lowering position of the lift arm 19.
The control range that can be set by the raising position setting device 57 and the control range that can be set by the lowering restriction setting device 60 are compared. If both control ranges overlap, the raising position is set. A work machine lifting / lowering control device for a work vehicle, comprising a control unit 50 for giving priority to setting of a setting device 57.