JPS6040801B2 - Ground work equipment with automatic lifting control mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides automatic lifting control of a towed ground work device attached to a tractor so that it can be raised and lowered, based on the detection result of a traction load detection sensor, so that the traction load is within the range set by a setting device. and a position control mechanism that automatically controls the lifting and lowering of the ground working device based on the detection result of the working height detection sensor to maintain the working height within the range set by the setting device, The present invention relates to a ground-based working machine with an automatic lift control device configured to preferentially regulate the lowering limit of the working device in the draft control based on the set working height based on the position control.

With the above-configured ground work equipment, by setting the working height setting device in position control to the lowest position of the work equipment, any working height (depending on the traction load setting) can be set within the lifting range up to this lowest position. By setting the draft control traction load setter to the maximum load value, position control can be performed over the entire range of elevation. It is possible to set the working height setting to an arbitrary position higher than the lowest lowering position and perform draft control (this is called mixing control) with this position setting height as the lowering limit. and
Mixing control is a method of controlling draft control in a work area where there is a locally deep soft area (light load area), and the work equipment is controlled to descend in this soft area to return the traction load within the set range, reducing the working height. In order to prevent a phenomenon in which the temperature becomes unexpectedly low, the lowering limit is regulated in advance by position setting.

However, in this mixed control, if the position setting height is set higher than the draft setting height (working height corresponding to the traction load setting), the working height will be regulated to the position setting value during the entire work process. On the other hand, if the position setting height is too low, the downward regulation in locally weak areas will not work (floating), and in this mixed control, the position setting height is shortened to the draft setting height. It is desirable to set them equally.

However, since the draft setting height itself varies greatly depending on the soil quality and the characteristics of the work equipment itself, it is difficult to set the position accordingly.For example, in the past, draft settings were set in advance. The system monitors the lifting and lowering status of the working equipment while gradually raising the position setting height from a low position, and considers the position where the lifting control of the working position is activated by changing the position setting height as the appropriate setting. The operation was cumbersome.

The present invention has been made in view of the above-mentioned circumstances, and includes a display mechanism for determining whether the state is a draft control state, a position control state, or a mixed control state, and whether or not the position setting is appropriate in the mixed control state. The purpose of this is to make it possible to easily visually recognize and perform desired control.

Embodiments of the present invention will be described below based on the drawings.

Fig. 1 shows a plow work machine in which a plow 2, which is an example of a towed ground work device, is connected to the rear of a tractor 1 so as to be able to rise and fall freely. The plow 2 is raised and lowered by moving the plow 2.

A traction load detection sensor 6 is installed at the base end of the traction lower link 5 that connects the plow 2 to the tractor 1, and is configured to electrically detect the displacement of a member that is elastically displaced by traction force using a differential transformer or the like. In addition, the base end of the lift arm 3 is equipped with a working height detection sensor 7 that detects the rotation angle of the lift arm 3 electrically using a potentiometer to determine the height of the plow 2 relative to the tractor 1. , is configured to perform draft control to stabilize the traction load and position control to regulate the working height using both sensors 6 and 7.

FIG. 2 shows the circuit configuration of the control mechanism,
First, the draft control mechanism will be explained.

The detection signal Vdx of the traction load detection sensor 6 and the setting signal Vd of the traction load setting device (consisting of a variable resistor) 9 adjusted by the manual lever 8.

are input to the subtraction amplifier circuits 10 and 11, respectively, and the detection signal V
dx is the setting signal Vd. When the deviation is larger than that, a signal [k, (Vdx-Vd.)] obtained by amplifying the deviation of both signals is taken out from one circuit 10, and the detection signal V is taken out from the setting signal Vd.
. When it is smaller, the deviation of both signals is amplified and converted into a signal.
(Vd.-Vdx)] is taken out from the other circuit 11. The signals from both circuits 10 and 11 are input to comparison/discrimination circuits 12 and 13, respectively, and compared with the reference signal Vd given by the unfavorable belt setting device 14, and the operation of the hydraulic cylinder 4 is controlled based on the result. It is configured to start the ascending drive circuit 16 or descending drive circuit 17 of the mud fin magnetic control valve 15. Note that the output of the sensor 6 is set to increase as the traction load increases. In other words,
When the traction load is within the set range, both subtraction amplifier circuits 10 and 1
The output from 1 is below the reference signal [k, lvdX-vd
. l≦vd], the level of the output signal Ud of the comparison circuit 12 becomes (low), and the level of the input signal UP of the rising drive circuit 16 also becomes (low), and the level of the output signal Ud of the comparison circuit 12 becomes (low).
6 is turned off, the level of the output signal Dd of the comparison/discrimination circuit 13 becomes (high), and the level of the input signal DN of the drop drive circuit 17 connected via the inversion circuit 18 becomes (low). , the circuit 17 is also turned off, and the control valve 15 is maintained in neutral. Furthermore, when the detected traction load increases beyond the set range due to an increase in plowing depth or hardening of the soil, only the output from the subtraction amplifier circuit 10 becomes larger than the reference signal, so (Vdx-Vd.)>Vd], and the comparison is made. The output signal Ud of the circuit 12 becomes high, and the rising drive circuit 16
The traction load is thereby reduced. Also, when the traction load decreases below the set range, the subtraction amplifier circuit 1
Only the output from 1 becomes larger than the reference signal [k, (V
d. -Vdx)>Vd], the output signal Dd of the comparison/discrimination circuit 13 becomes (low), and only the lowering drive circuit 17 that receives the inverted signal is activated, thereby increasing the traction load. Therefore, in draft control, the plow 2 is automatically raised and lowered to maintain the traction load arbitrarily set by the setting device 9 (including a dead zone of a certain width), and if the soil quality of the work area is uniform, the selected and adjusted plowing The depth will be maintained.

Further, the position control mechanism is configured as follows.

A detection signal Vpx from the work support layer height detection sensor 7 and a setting signal Vp from a work height setting device (consisting of a variable resistor) 20 adjusted by a manual lever 19. are respectively the subtraction amplifier circuit 2
1 and 22, and the detection signal Vpx is the setting signal Vp.
When it is smaller, the signal [k2
(Vp.-Vpx)] is taken out from one circuit 21,
Further, when the detection signal Vpx is larger than the setting signal, a deviation amplified signal [k2 (Vpx-Vp.)] of both signals is taken out from the other circuit 22. The signals from both circuits 21 and 22 are input to comparison and discrimination circuits 23 and 24, respectively, and are compared with the reference value Vp given by the fixed belt setting device 25, and based on the result, the electromagnetic control valve 15 is used for raising and It is configured to start the lowering drive circuits 1, 6, and 17. Note that the outputs of the sensor 7 and the setting device 20 are set to increase as the working height increases. In other words, when the detection work height is within the set range, k2lVp.

-VpXI≦Vp, the level of the output signal Up of the comparison/discrimination circuit 23 becomes (low), the level of the output signal Dp of the comparison/discrimination circuit 24 becomes (high), and accordingly, the rising and falling drive circuits The input signals UP and DN of input signals 16 and 17 are both at (low) level, and the control valve 15 is maintained neutral. Also, when the detection work height is lower than the setting range, k2
(Vp.-Vpx)>Vp and the output signals Up and Dp
Both become high (high), and only the rising drive circuit 16 is activated. Also, when the detection work height is higher than the setting range, k
2(Vpx-Vp.)>Vp, and the output signals Dp, D
p both become (low), and only the lowering drive circuit 17 is activated. Therefore, in position control, the plow 2 is automatically raised and lowered to maintain an arbitrarily set working height (relative to the tractor).

According to the above configuration, it is possible to perform work using three types of elevation control as shown below.

■ By setting the working height setter 20 of the draft control position control system to the lowest position, plowing depth control based on load control is possible over the entire range up to the lowest position according to the adjustment of the traction load setter 9. becomes.

■ If the traction load setter 9 of the position control draft control system is set to the lowest position (maximum load setting position), the working height setter 2
According to the adjustment of 0, the height of the working device can be regulated over the entire range of lifting and lowering.

(2) Mixing control By setting the working height setter 20 of the position control system to an arbitrary position higher than the lowest lowering position, draft control can be performed with the set height as the lowering limit.

In addition, 26 in FIG. 2 is the drive circuit 1 for raising and lowering.
6 and 17 with priority, and the automatic control is performed at the neutral position n shown in the figure.
When switched to contact a, only the drive circuit 16 for ascending is activated, and when switched to contact b, the drive circuit for descending 17 is activated.
The contact point a is used to raise the plow when changing the direction of the aircraft, and the contact point b is
is used for temporary forced descent during work.

The present invention further includes the following configuration. That is, both the sensors 6 and 7 are connected to a circuit 27 for determining the operating state, and the result of the determination is displayed on a lamp display mechanism 28 provided near the control section.

The outline of the configuration of the discrimination circuit 27 is shown in FIG. 3, and based on the discrimination diagrams in FIGS. 1st
A discrimination circuit 29 discriminates, and a second discrimination circuit 30 discriminates three operating ranges of P, , F2, and P3 in the position control system.

That is, the first region ○ of the draft system has a set value f [for example, 200
k9], that is, in the case of overload, the puller 2 is raised in the raising operation range, and the third area D3 is set from the lower limit line 2 of the dead zone A to the set value f' [for example, 200k9].
] In the following cases, that is, in the case of a light load, the lowering operation area of the plow 2 is used, and the area that deviates from this is the neutral second area D.
Set as 2.

In addition, when the detected value is smaller than the upper limit line 3 of the fuwaza zone B in position control, that is, when it is deeper than the plowing depth setting depth, the first region P of the position system is set as the raising operation region of the plow 2, and the first region P, 3 area P3 is the lower limit line of dead zone B 4
If the detected value is greater than the set value h (for example, 5 k), that is, if it is shallower than the set plowing depth, the plow 2 is determined to be in the lowering operation region, and the region outside of these is determined to be the neutral second region P2. Then, each area D2, D3, P2 except the first draft area ○, which is in the draft raising operation state, and the position first area P, which is in the position raising operation state.
, P3, the draft control state D, position control state P, mixed control state M, and floating state F are further determined, and based on the results of this determination, the draft control state lamp Ld of the display mechanism 28 shown in FIG. , the position control state lamp Lp, the mixture control state lamp Lm, and the floating state lamp Lf are selectively turned on. That is, as is clear from the discrimination circuit shown in FIG. When P, is determined, the position control state lamp Lp is lit to indicate that the position control state is in effect.When the first discriminating circuit 29 discriminates D2 and the second discriminating circuit 30 discriminates P2, the mixed control is started. The status lamp Lm is lit to indicate that the mixing control status is in effect.

In such a case, the draft control status lamp Ld does not light up because the second AND circuit D2 is not established by the inversion circuit B, and the position control status lamp LP also does not light up because the second AND circuit D2 is not established by the inversion circuit B.
Therefore, the third AND circuit is not established, so the light does not light up.
Then, when the first discrimination circuit 29 discriminates D3 and the second discrimination circuit 30 discriminates P3, the fourth AND circuit L is established and the floating state lamp Lf is lit, indicating the floating state.

According to the above configuration, the control state can be grasped simply by looking at the lamp lighting location of the display mechanism 28, and if the floating state lamp Lf is lit when performing the mixing control state, the mixing control state lamp Lm is lit. Proper setting can be achieved by adjusting the position setting plowing depth to the shallow side until the position changes.

In the embodiment, the display mechanism 28 that performs a lamp display is illustrated, but the display mechanism 28 can also be implemented with a pointer or the like displaced to indicate each area.

As explained above, according to the present invention, it is possible to check at a glance the suitability of draft control, position control, mixing control, and position setting in mixing control, and to accurately select and set the desired control form. I am now able to do good work.

[Brief explanation of the drawing]

The drawings show an embodiment of a ground work machine with an automatic lift control device according to the present invention, in which Fig. 1 is an overall side view, Fig. 2 is a control circuit diagram, and Fig. 3 is a diagram showing a system for distinguishing and displaying the control operating state. A schematic configuration diagram, FIGS. 4 and 5 are diagrams for determining the setting of the control operation area, respectively, and FIG. 6 is a front view of the display mechanism. 1... Tractor, 2... Traction type ground work device, 6... Traction load detection sensor, 7...
・Working height detection setter, 9... Traction load setting device, 20... Working height setting device, 27...
Discrimination circuit, 28...Display mechanism. Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 2

Claims (1)

[Claims] 1. The towed ground work device 2, which is attached to the tractor 1 so as to be able to rise and fall, is automatically controlled to rise and fall based on the detection result of the traction load detection sensor 6, so that the traction load is within the range set by the setting device 9. A draft control mechanism that maintains the height of the ground work device 2, and a position control mechanism that automatically controls the lifting and lowering of the above-mentioned ground work device 2 based on the detection result of the work height detection sensor 7 to maintain the work height within the range set by the setting device 20. In the ground work machine with an automatic lifting control mechanism configured to preferentially regulate the lowering limit of the working device in the draft control by the set working height by the position control, the detected value by the traction load detection sensor 6 is provided. A determination circuit 27 is provided to determine in which of a plurality of regions the detected values from the working height detection sensor 7 are located, and the combined state of the regions to which the detected values of both sensors 6 and 7 belong. Visual display mechanism 2
8. A ground work mechanism with an automatic elevation control mechanism, characterized in that it is configured to be displayed as 8. 2. The ground work machine according to claim 1, wherein the display mechanism 28 is configured to selectively light up a plurality of lamps Ld and Lm.