JPS63103129A - Controller for attitude of working tool of front loader - Google Patents

Abstract

PURPOSE:To permit the contact of working tool with the ground in a target attitude even when lowering it from any height by a method in which the height of the working tool is measured when the lowering operation of a boom is started, and when the height is low, the attitude controlling and acting speed of the working tool is increased. CONSTITUTION:In a front loader to automatically control the attitude of a working tool in its lowering position, during the starting period of lowering action of the tool, the height of the tool is calculated from angle sensor 32 for boom, etc., by a height measurer 62. According to the height signal, the gain of a variable gain amplifying circuit 63 is automatically adjusted. In short, when the working tool is in low position, it is necessary to quickly control the attitude and, therefore, the gain is raised. Even when the lowering distance is short, the working tool can be contacted with the ground in a target attitude.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Life) The present invention provides a TiC front loader work implement posture control device.
It is related to

(Prior art) The 5-front rogue, which is attached to the tractor body and used for work, has a boom that is pivoted to the tractor body so that it can be raised and lowered, and
A work tool such as a packet is rotatably attached to the tip of the zoom, and a solenoid valve corresponding to each cylinder is interposed in the hydraulic circuit of the zoom cylinder and packet cylinder that operate these games and U/< get. This solenoid valve controls the lifting and lowering of the boom, the scooping of packets, and the rotation in the dumping direction.

When scooping up earth and sand with this type of 70 loader, it is necessary to ground the bottom of the packet horizontally to the ground. Therefore, while detecting the attitude of the packet during the downward movement of the zoom, the
That is, there are devices that control the attitude of the packet rather than grounding horizontally.

(Problems to be solved by the invention) -However, in the past, the packet side independently controlled its attitude regardless of the zoom descending speed, so there were cases where the packet could not reliably land on the ground with the bottom horizontal.

In other words, if the zoom is lowered from a sufficiently high position, or even if the height is not sufficient, the packet will be in the target attitude (bottom horizontal).
If there is no large deviation from the position, the packet can be controlled horizontally on the bottom during the downward movement of the zoom; however, if the boom position is low, due to the responsiveness of the packet control system, etc. When the packet touches the ground, it may not be possible to correct its attitude to a horizontal bottom state.

In view of these conventional problems, the present invention changes the posture control speed of the work tool in accordance with the height at the start of the downward movement during the downward movement of the zoom, so that the work tool in the descending position always maintains the target posture. The purpose is to be in control.

(Means for Solving the Problems) The present invention provides a means for solving the problems when the zoom (10) is lowered.
10) In a front lobe work implement attitude control device that detects the attitude of the work implement 03 at the tip and controls the attitude of the work implement 03 in a lowered position to bring the work implement 03 into the target attitude, the boom A height measuring means v3υ is provided to measure the height of the working tool (131) at the start of the downward movement of flol, and the height signal from this height measuring means t6IJ determines the posture control function of the working tool 031 when the height is low. Work A (speed control means (6~) for changing the posture 11J speed of I3 is set up so that f'li becomes faster.

(For) When lowering the game f10) from the raised position and setting the work implement at the lowered position to the target posture (for example, horizontal grounding),
Height measuring means: Measures the height at the start of the downward movement of the V work tool as shown in the figure. Then, when the boom (lO) moves to the lowering operation, while simultaneously detecting the attitude of the working tool α stage, the attitude control is performed so that the working tool a31 at the lowering position reaches the target attitude, but the height measuring means (2) Height No. 48 adjusts the posture according to the height so that the posture control operation becomes faster when the height of the work implement is low. INf
lll change the speed. For example, this is a variable gain amplifier circuit (
Do it with a hook. By changing the attitude control speed of the working tool (13), it is possible to maintain the work AσJ at the lowered position at the target attitude.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example.
In the figure, (1) is the tractor body, (2) is the front wheel, (
3) is the rear wheel, 14) is the rear wheel 7 ender, (61 is the driver's seat, and 61 is the 70 loader, which is detachably installed on both sides of the tractor body III via the mounting base (7). The mast (81) and the pivot (9) at the upper end of this mast (8)
in! + A boom cylinder (111) for raising and lowering the friend game flol, which is pivoted so that it can be lowered, and this boom (lO)
It consists of a packet (work tool) (I3) rotatably supported at the tip of the zoom fll+ about a pivot axis α2, and a packet cylinder for rotating the packet α4.

Q5J is an inclination sensor that detects the inclination of the tractor body fi+, and is installed on the 70 loader (61 side, for example, the mast (8). Q5J is an attitude sensor that detects the rotating attitude of the packet. These sensors (151cI61 are attached to one racket αη of
As shown in FIG.
and a potentiometer circle. Weight plate 3υ
is attached to the rotating shaft (c) supported by the case, and the potentiometer circle is attached to the weight plate ■υ via the rotating shaft.
Therefore, the weight plate 3η responds to changes in the attitude of the tractor body (1) and the packet αJ, and a telephonic voltage signal is output from the potentiometer according to the attitude. Note that damper oil (23a) is contained in the chamber 09).

3z is an angle sensor consisting of a potentiometer or the like, which is provided in conjunction with the pivot +91 rather than detecting the angle of zoom (lO).

(241 is an operating device, and as shown in FIGS. 4 to 6, the case '251 installed on one side of the driver's seat (51) on the rear wheel ender (4) is The control lever t2E1, which can be operated freely, and the first and second potentiometers, etc., which are closely linked to this control lever, are incorporated.That is, the control lever is connected to the movable frame 4 through the horizontal axis example. The movable frame 4 is pivotally supported, and the movable frame 4 is connected to the case 1 via a front-back axis 91).
It is supported on the 25+ side, so the operating lever depth is 1.
With the two axes of the horizontal axis for reading and the front and back axis 311 as fulcrums,
As shown in Fig. 7, it is set to 15 so that the power can be operated in any direction. Note that the operating lever holder is elastically held in the neutral position by a spring (not shown).

The first potentiometer constitutes an elevation command means for instructing the elevation of the zoom (101). The second potentiometer outputs a command signal of the corresponding voltage.The second potentiometer constitutes one stage of the Dan 1 degree command means for issuing the Dan 11 command of the bucket) 03, and the front and rear axis 31). The operating lever (
(to)), and outputs a voltage command signal according to the amount of operation of the operating lever 4. At the upper end of the operating lever 4, there is provided a push-button type automatic switch that is turned on during automatic operation.

Fig. 7 shows the hydraulic circuit of the 7th cylinder old l and the packet cylinder round, and the 11th cylinder H controls the lift cylinder (II). The solenoid valve has a rising solenoid (1119) and a descending solenoid. The β force is an M2 electromagnetic valve that controls the packet cylinder circle, and has a Dan 1 solenoid and a scoop solenoid. These solenoid valves!; (410η Figure 1 shows the electric circuit that drives and controls the 9th position of the solenoid valve. In Figure 1, 14011411 is the amplifier circuit, and '4Z is the operating direction during lifting/lowering. The first discrimination circuit outputs a rising signal when the command signal from the first potentiometer (b) is larger than the reference value, and outputs a falling signal when it is smaller than the reference value. It has become.

1431 is Dan 1. The second one that discriminates the direction of movement when scooping.
Similar to the first discrimination port 44, the discrimination circuit outputs a dump signal and a scoop signal, respectively, in response to a command signal from the second potentiometer.

The mouse is a rising solenoid drive circuit, (the fourth one is a falling solenoid drive circuit, and these are the analog switch units or [14
71 is turned on to drive either the ascending solenoid or the descending solenoid. 148I is a dump solenoid drive circuit, +49112 is a solenoid drive circuit, and when there is a dump signal or a scoop signal from the second discrimination circuit 143, the analog switch 1611m or Sυ is turned on to drive the gun gun solenoid. I'll do it 5iC7! There is

1521 is sash 1, hold circuit, automatic switch 3
When the attitude sensor is turned on, the attitude signal of the packet αa from the attitude sensor is stored. 153r4 is an analog switch, and when the automatic switch port is off (manual), it is 4C7.

When the switching switch (5) is turned on, the analog switch r4 is turned on via the NOT gate open, and the switch between manual and automatic mode is switched on. - and a contact β force in horizontal grounding mode, and when in posture holding mode, analog switch I81 is turned on to perform a saguru and hold circuit, and the signal from the force is sent to deviation amplification circuit 8Ir1591. In horizontal grounding mode, analog switch 16111 is turned on. is turned on and the slope signal from the slope centimeter 05) is sent to the deviation amplification circuit.

:6υ is a height calculation circuit that calculates the height of the bucket 101 at the start of the downward movement of the zoom f101 from the angle signal of the angle sensor scale.The angle centimeter 3z and the height calculation circuit 1611 constitute a height measuring means diagram. ing.

(A variable gain amplification circuit serves as a speed control circuit, and the attitude control speed of the packet αJ becomes slower when the packet height is high, and becomes faster when the packet height is low, depending on the relationship signal from the flatness calculation circuit i6D. The circuit is configured so that the gain changes as shown in FIG. The deviation signal of li5gj is sent to the variable gain amplifier circuit, 63I, and it Jl)
(2,) Turn on the analog switch through the IIKNOT dart alfl, and directly look at the deviation signal to the second discrimination circuit, and the lensoid drive I! ! It is designed to be sent to the family's heir.

In the above configuration, when performing manual control, it is sufficient to operate the operating lever (to) at 11 when the automatic switch of the operating lever is turned off, and the operating lever 2Q is moved in the direction of the arrow shown in FIG. By operating, it is possible to zoom (raise, lower, bucket of 1α), dump tEl, pick, and compound operations that combine these (see FIG. 8).

For example, when scooping the packet αJ, if the operation lever (toward) is rotated toward the left scooping side, the second potentiometer 2
1111 is activated, the resistance value changes according to the amount of operation, and a predetermined command signal is output. Then, since the second discrimination FI & old command signal is discriminated and a scooping signal is output, the analog switch is turned on, and the command signal from the second voicing meter is sent to the scooping solenoid drive circuit 4, which drives this scooping solenoid. Due to the circuit darkening, the rake solenoid c19) is driven with a current proportional to the command signal, and the second electromagnetic valve port is switched to the rake side. Therefore, the second solenoid valve a switches to the rake side with an opening proportional to the command signal, and the packet shilling α contracts, so that the packet
When using automatic control to perform a scooping motion at 21 m, press the automatic switch on the operating lever (to) to turn it on, and use the mode selector switch to switch between posture holding mode and horizontal grounding mode. When the automatic switch is turned on, the analog switch (53i) is turned off, the second potentiometer 28 is released, and at the same time, the analog switch (53i) is turned on.

As shown by the solid line in Fig. 9, when the bucket) 03) is moved at the raised position of the zoom (10) to release the earth and sand, the packet α4 is lowered and the bottom surface is horizontally grounded. To do this, set the mode selector switch open to horizontal grounding mode, and operate the upper control lever in the downward direction. Then, as in manual control, the lowering solenoid (451) is energized and the first solenoid valve switches to the lowering side, and the zoom cylinder (I
l+ contracts and the zoom (10) starts to move downward at a speed proportional to the amount of operation of the operation lever example. In addition, in the horizontal grounding mode, the analog switch F6 (one flash is turned on and the analog switch (capital) is turned off, so the deviation amplification circuit receives the attitude signal of packet α4 detected by the attitude sensor αQ,
The deviation from the inclination signal of the tractor body +11 detected by the inclination sensor σ6 is reduced, and the deviation signal is sent to the variable gain amplification circuit 1631. On the other hand, the angle sensor '32 detects the angle of the zoom (lO) at the start of the downward movement, and the height calculation circuit βυ inputs the angle signal to the bucket)03
1 is calculated, and the gain of the variable gain amplifier circuit j631 is controlled by the height signal. In this case, the bucket 1-Q3 has deviated significantly toward the Dan 1 side from the attitude when it should touch the ground horizontally, but since the packet α4 is in a relatively high position, the bucket has been sufficiently ) The gain is set to 5 so that the attitude control of I13 can be performed. If the height of the packet 0 country is low, the attitude control operation must be made faster to control the attitude of (bucket) (1B+), so the gain is increased by the height signal. The deviation signal amplified by the gain of is sent to the second discrimination circuit via an analog switch.
) determines the direction in which attitude control should be performed. In this case, the bucket) Q31 is on the dumping side, so the second discrimination circuit (43) outputs the scooping signal and turns on the analog switch.

Therefore, variable gain amplification circuit 8I! :The deviation signal amplified by the solenoid valve is sent to the rake solenoid drive circuit via the analog switch and drives the rake solenoid of the second solenoid valve port, so the second solenoid valve 3η is proportional to the deviation signal. Switches to the narrow side depending on the opening, and the packet cylinder (I41
is contracted, and the packet is controlled to a posture in which it should touch the ground horizontally. Therefore, if the zoom flol descends to the lower limit l, the packet Q31 will touch the bottom surface horizontally, so after that,
If the tractor body [1] is moved forward immediately, it is possible to scoop up earth and sand. In addition, the inclination sensor u81 detects the inclination of the tractor body +11, and the inclination signal and packet α
Since the deviation from the attitude signal of the cloud is determined, the bottom surface of the packet α4 can be reliably grounded even on a slope.

The height of the bucket 13 is measured as follows.

That is, as shown in Fig. 9, when the tractor body ■ is on a horizontal plane and the line connecting the bottom of the packet α3 and the grounding point of the front and rear wheels +21131 is horizontal, the angle attached to the axis +91 of the game troll Sen? 'The angle indicated by 3S5 is θO
Then, from the axis α of packet αJ to the axis of boom (10) +91'! Let the height at 11 o. Therefore, the first
As shown in FIG. 0, the magnitude relationship of go with respect to θ is determined from the angle signal of the angle sensor 3z. If the set θ is θO, then the height h of the packet is ho+ La1n (θO−
θ), and conversely, if θ>θO, then ha
-Lsin (θ0). In addition,
L is the length between the axes (9) and 04 of the game cry.

Note 1. The height of the bucket Q31 can also be determined by attaching a tilt sensor to the base of the zoom flol and detecting the tilt angle of the zoom (10) using the tilt sensor.

Hold the posture of packet 0 ~ 1'! '! in! When lowering the robot, set the mode changeover switch +55 to posture holding mode and turn on the automatic switch. Then, the attitude signal of packet 03 detected by the attitude sensor (+61) is sampled and stored in the hold circuit, and the deviation amplification circuit calculates the deviation between this signal and the attitude signal from the attitude sensor 3 that changes as the user moves up and down. is frozen, and the deviation signal is sent to the subsequent stage via the analog switch (6η (b)), and the packet α ~
controls the automatic switch to maintain its position when it is turned on.

In the embodiment, the bucket HI3 is used as an example of the working tool, but the tool is not limited to the packet α3, and may be a fork or other attachment. In that case, if you want to make it possible to attach and detach the work tool and change it again, attach a mounting bracket to the tip of the zoom (lO), and attach the work tool to this mounting bracket with a pin etc. so that it can be attached and detached. In addition to the structure, there is also an attitude sensor IJi on the mounting bracket side! Even if there are various types of fil:MA, if you set up a ``L'', you can easily sense the posture of each worker. t16), which is very convenient.

Further, the inclination sensor tJ51 may be attached to the tractor body (11).

Furthermore, in the example, horizontal grounding was shown as the target attitude, but
It can also be applied when it is necessary to maintain a predetermined posture in a lowered position.

(Effects of the Invention) According to the present invention, the height of the work implement at the start of the descending operation is measured, and based on the height signal, the attitude control speed is changed so that the attitude control operation of the work implement becomes faster when the height is low. Therefore, no matter what height the work implement is lowered, the work implement at the lowered position can be controlled to the target posture.

[Brief explanation of the drawing]

The drawings illustrate one embodiment of the present invention, and show the first embodiment of the present invention.
The figure shows the electric circuit diagram of the control system, and the second figure is a side view of the tractor.
Figure 6 is a sectional view of the processor, Figure 4 is a rear view of the operating device,
5 is a cross-sectional rear view, FIG. 6 is a view taken along the line X-X in FIG. 5, FIG. 7 is a hydraulic circuit diagram, FIG. 8 is an explanatory diagram of the control position, and FIG. FIG. 10 is a 70-chart. +11...tractor body, 161...70 loader, fio+...boom, 031...bucket) (
f'>-work tool), Hiro... Tilt sensor, 1161...
Attitude sensor, ■Furnace...Operating device, (to)...Operation lever, Open end...Potentiometer (command means), 9 Rust...
...Solenoid valve, :4211431...Discrimination circuit, 69)
...Difference amplification circuit, 1@...Height measurement means, [Shout-
...Variable gain amplification rotation (speed control means).

Claims (1)

[Claims] 1. When the boom (10) is lowered, the boom (10)
In a work tool posture control device for a front loader, which detects the posture of the work tool (13) at the tip and controls the posture of the work tool (13) so as to bring the work tool (13) into a target posture at a lowered position. , height measuring means (61) for measuring the height of the working tool (13) at the start of the downward movement of the boom (10).
), and according to the height signal from the height measuring means (61), the attitude control speed of the work implement (13) is changed so that the attitude control operation of the work implement (13) becomes faster when the height is low. A work implement posture control device for a front loader, characterized in that a speed control means (63) is provided for controlling the position of a work implement.