JPH0435575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fixed-dimension excavation control device for performing excavation work at a constant depth in a grab working machine.

[Conventional technology]

The bucket operation during fixed-size digging work using a grab working machine will be explained with reference to FIG.

The bucket B is driven up and down by both winch drums (not shown) for supporting the bucket and for opening and closing the bucket, and during excavation, lowers the bucket, reduces the lowering, and lowers the bucket.
Each operation of hoisting down, stopping, sinking and grabbing, sinking and grabbing, and hoisting is performed continuously. In the figure, D ₁ indicates the lowering deceleration start depth, D ₂ indicates the lowering stop depth, and D ₃ indicates the sinking and grabbing stop depth, and the distance from the water surface to the sinking and grabbing stop depth D ₃ is always constant for each cycle of bucket work. By maintaining this, it is possible to carry out excavation to a fixed size.

Each operation of the bucket cart B from hoisting down to hoisting is controlled by a drive system that drives a winch drum, except for sinking and grabbing and stopping.

In other words, in this drive system, a torque converter equipped with a modulating clutch is installed on the output side of the engine, and by controlling the degree of engagement of the modulating clutch by operating the modulating clutch lever, lowering of the winch drum (so-called bucket Rotation control is performed (tostal down) → stop (same stall stop) → hoisting, and speed control during both lowering and hoisting rotations.

In addition, the control of sinking grip and stopping of sinking grip is as follows.
This is done by operating the brakes while in free fall.

[Problem to be solved by the invention]

Conventionally, the lowering deceleration and lowering stop of the bucket at a predetermined depth have been controlled manually by the operator based on the depth gauge instructions or marks attached to the bucket support rope. . Further, brake control for sinking and stopping is also performed by the driver's pedal operation.

This places a heavy burden on the driver and causes severe fatigue, and the control situation varies depending on the skill level of the driver, resulting in poor precision in the work of digging to size.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a sizing excavation control device for a grab work machine that can automatically and accurately control the lowering, stopping, and sinking/grabbing of a bucket.

[Means to solve the problem]

In the present invention, a torque converter equipped with a modulating clutch whose degree of engagement is variable is provided in the drive system of a winch drum that drives a bucket cart to be hoisted up and lowered, and the degree of engagement of the modulated clutch is controlled by operating a modulating clutch lever. A drum that controls the rotation and speed of the winch drum during the lowering, lowering deceleration, lowering stop, and hoisting operations of the winch drum, and connects and separates the winch drum from the drive system. The drum clutch includes a clutch and a brake device that brakes the winch drum in the free fall area of the bucket with the winch drum separated from the drive system, and controls the rotation of the winch drum from lowering rotation to stopping. According to the bucket depth, the operations of lowering the bucket, decelerating the lowering, and stopping the lowering are performed, and the sinking and grabbing operation of the bucket is performed in the free fall area, and after this sinking and grabbing operation, the winch drum is unwinded. In a grab working machine configured to hoist a bucket by upward rotation, the degree of coupling between a depth gauge that detects the bucket depth and the modulate clutch for stopping the winch drum from lowering is determined. A coupling degree setting storage means for setting and storing, and work conditions for setting the start depth of the lowering deceleration operation of the bucket, the lowering stop depth, the sinking and grabbing operation stopping depth, and the coasting correction depth before the sinking and grabbing stop. setting means and hoisting of the bucket;
hoisting/lowering discrimination means for discriminating between hoisting and lowering operations;
Depth determination means for determining whether the bucket depth detected by the depth gauge has reached each set depth by the work condition setting means; and a coupling degree setting storage means for determining whether or not the bucket depth detected by the depth gauge has reached each set depth by the work condition setting means. A coupling degree command for lowering deceleration and lowering stop is output to the modulating clutch based on the set coupling degree, the instructed coupling degree by operating the modulating clutch lever, and the depth reaching signal from the depth determining means. It is equipped with a lowering deceleration/stop control circuit, and sinking and grabbing control means for outputting a brake activation signal to the brake device based on a depth attainment signal from the depth determining means when the bucket is sinking and grabbing. be.

[Effect]

With this configuration, when the bucket depth reaches the preset lowering deceleration start depth, a command signal for lowering deceleration and stop is output to the modulating clutch, and the bucket depth is also set in advance. Since a brake activation signal is output to the brake device when the depth for sinking and grabbing operations is reached, the lowering deceleration, stopping, and sinking and grabbing stopping operations are automatically and accurately performed at the appropriate depth. Therefore, the operational burden on the driver is reduced, and the accuracy of the sizing excavation work is improved.

〔Example〕

FIG. 2 shows the hydraulic operating circuit for the winch drum.

Reference numeral 1 denotes a support drum that drives the entire bucket cart up and down; 2 an opening/closing drum that opens and closes the bucket cart; both drums 1 and 2 are simultaneously driven down by an engine (not shown), and the bucket cart performs the lowering operation;
The support drum 1 is separated from the drive system and is lowered and rotated by the bucket in the free-falling direction, and the opening/closing drum 2 is hoisted up and rotated to close the bucket. In this state, both drums 1 and 2 are simultaneously driven to wind up the bucket tote, and while the hoisting is stopped, the opening/closing drum 2 is lowered to open the bucket tote.

The engine output is transmitted to the rotating shafts 1a, 2a of both drums 1, 2 via a torque converter with a modulating clutch (not shown), and the rotational force of these rotating shafts 1a, 2a is transmitted to the supporting drum clutches 3, 2a.
It is transmitted to the drums 1 and 2 via the opening/closing drum clutch 4. 3a and 4a are both drum clutches 3 and 4
Both clutch cylinders 3a, 4a are controlled by drum control valves 5, 6 operated by levers 5a, 6a, respectively.
6 is operated to the operating position B, hydraulic pressure is supplied to the clutch cylinders 3a, 4a, and the clutches 3,
4 is on, that is, the drums 1 and 2 are connected to the drive system, and when the valves 5 and 6 are set to the neutral position A, the hydraulic pressure supply to the clutch cylinders 3a and 4a is stopped and the clutches 3 and 4 are is off,
That is, the drums 1 and 2 are separated from the drive system.

Further, both drums 3, 4 are provided with positive brakes 7, 8 and negative brakes 9, 10, respectively, and the positive brakes 7, 8 are controlled by positive brake control valves 11, 12, which are operated by pedals, respectively. be done. On the other hand, among negative brakes 9 and 10,
The opening/closing drum negative brake 10 is directly connected to a hydraulic line, and the support drum negative brake 9 is controlled by a negative brake electromagnetic control valve 13.

Next, the configuration of a control system that controls the operations of lowering the bucket, decelerating the lowering, stopping the lowering, sinking and grabbing, and sinking and stopping the bucket will be explained with reference to FIG.

15 is a modulating clutch lever that controls the degree of engagement of the modulating clutch 16; 17 is a depth gauge that detects the depth of the bucket; 18 is a lever 5a of the support drum control valve 5 in FIG.
Signals from these lever switches are input to the control section A, which is turned on when the lever switch is set to the neutral position.

The control unit A is a coupling degree setting/operation switching switch 1.
9, coupling degree setting switch 20, coupling degree memory circuit 21, hoisting/lowering discrimination circuit 22, work setting switch 23, depth discrimination circuit 24, hoisting, hoisting, and lowering deceleration/stop. , sinking and grabbing control circuits 25,
It consists of 26, 27, and 28.

The coupling degree setting/operation selector switch 19 is used to stop lowering the bucket (stall stop) before starting work.
The coupling degree C 2 preset in the setting mode is switched to a setting mode in which the coupling degree of the modulating clutch 16 is set in order to set the coupling degree, and an operation mode after this coupling degree is set, and the coupling degree C ₂ preset in the setting mode is stored in the coupling degree storage circuit 21. It is then memorized.

The hoisting/lowering determination circuit 22 determines whether the bucket is in the hoisting state or the hoisting down state based on the rotation of the support drum 1, etc., and when the hoisting state is determined by this discrimination circuit 22, the hoisting control is performed. An activation signal is output to the circuit 25, and when it is determined that the lowering is required, the lowering or lowering is performed via the depth determination circuit 24 according to the bucket depth.
Lowering deceleration/stop, sink grip control circuits 26, 2
A manual signal is output to either 7 or 28.

Before work, the work setting switch 23 sets in advance the lowering deceleration start depth D ₁ , the lowering stop depth D ₂ , the sinking gripping stop depth D ₃ , and the negative brake electromagnetic control valve 13 for the support drum is activated during the sinking gripping stop operation. A coasting correction amount α (coasting correction start depth=D ₃ −α) is set to correct the bucket coasting amount due to the time difference from the time when the bucket starts sinking until the bucket actually sinks and stops. These set values D ₁ , D ₂ , D ₃ , α are input to the depth determination circuit 24 and compared with the actual bucket depth.

A hoisting determination signal from the hoisting/lowering discriminating circuit 22 and a coupling degree instruction signal from the modulating clutch 15 are input to the hoisting control circuit 25 during hoisting. On the other hand, the coupling degree instruction signal from the modulating clutch lever 15 and the depth discrimination signal from the depth discrimination circuit 24 are input to the lowering, lowering deceleration/stop, and sinking grip control circuits 26, 27, and 28. . In addition, the lowering deceleration/stop control circuit 27 is also input with the depth signal from the depth gauge 17 and the coupling degree C ₂ signal for stopping the stall stored in the coupling degree storage circuit 21. The on/off signal of the lever switch 18 is input to the gripping control circuit 28. Each of these control circuits 25 to 28
outputs a coupling degree command signal to the modulating clutch 16 based on the input signal. In addition, the sinking and gripping control circuit 28 separately outputs activation and deactivation signals for the support drum negative brake electromagnetic control valve 13.

Next, the effect will be explained.

() Operation preparation ()-1 Clutch engagement degree setting Set the setting/operation selector switch 19 to setting mode. In this state, operate the work equipment, operate the modulate clutch lever 15 to stall the bucket belt, turn on the coupling degree setting switch 20, and set the clutch coupling degree _C2 at this time to the coupling degree when the bucket belt is stopped lowering. degree of coupling degree storage circuit 2
Store it in 1.

()-1 Work condition setting The work setting switch 23 determines the lowering deceleration start depth D ₁ , the lowering stop depth D ₂ , the sinking and grabbing stop depth (dredging depth) D ₃ , the coasting correction amount α (coasting correction start depth )
Set. Each of these settings is the bucket capacity,
Selected according to work conditions such as hardness of dredged material. After this, the setting/operation changeover switch 19 is switched to the operation mode.

() Operation ()-1 Lowering Lowering hoisting/lowering discrimination signal from the hoisting/lowering discrimination circuit 22,
Depth signal from depth gauge 17, work setting switch 2
Based on the set value according to No. 3, an actuation signal is output from the depth discrimination circuit 24 to the lowering control circuit 26. At this time, the degree of coupling _C1 commanded by the modulating clutch lever 15 is directly output to the modulating clutch 16. Therefore, during this lowering, the bucket is controlled to be lowered (stall lowered) based on the operation of the modulating clutch lever 15 by the driver.

()-2 Lowering deceleration/stop When the bucket depth reaches the preset lowering deceleration start depth _D1 , an activation signal is output from the depth determination circuit 24 to the lowering deceleration/stop control circuit 27.

In this case, the lowering deceleration/stop control circuit 27 determines the clutch engagement degree C ₁ at the time of stall lowering and the preset clutch engagement degree for stall stop.
Based on C ₂ , the depth at which the bucket starts lowering deceleration.
From D ₁ until reaching the lowering stop depth D ₂ , the degree of clutch engagement is calculated in a direction that gradually increases in proportion to the increase in depth, and a command for the calculated degree of engagement is output to the modulating clutch 16 . As a result, the lowering speed of the support drum 1 is reduced in proportion to the depth, and the bucket is gradually decelerated and stopped at the set stop depth _D2 . This control prevents the bucket from stopping suddenly and allows a smooth stall stop.

()-3 Sink grab As described above, the bucket stops at the lowering stop depth (sink grab start depth) _D2 , and when the operator confirms this, the lever 5a of the support drum control valve 5 is moved to the neutral position. When returned, an actuation signal is output to the sink grip control circuit 28 based on the determination signal from the depth determination circuit 24 and the ON signal of the lever switch 18.

At this time, since the support drum 1 is separated from the drive system, the bucket falls freely while being braked by the positive brake 7. Further, from the sink grip control circuit 28, the degree of engagement indicated by the operation of the modulating clutch lever 15 is directly outputted to the modulating clutch 16, and the opening/closing drum 2 rotates at a speed according to this indicated degree of coupling, thereby closing the bucket.

Then, the bucket is at a depth just before the preset sinking and grabbing stop depth D ₃ by the coasting correction amount α.
That is, when the coasting correction start depth is reached, a brake activation signal is output from the control circuit 28 to the negative brake electromagnetic control valve 13 for the support drum, and the control valve 1
3, the negative brake 9 of the support drum 1 is activated to stop the drum 1, and the bucket sinks and stops at the stopping depth _D3 .

In this way, from the time when the negative brake 9 starts operating by the operation of the control valve 13 until the bucket actually stops, the coasting amount (coasting correction amount) α is calculated by considering the bucket coasting amount. By outputting an activation signal to the negative brake control valve 13 for the front support drum, the bucket can be reliably stopped at the preset sinking and gripping stop depth _D3 . In other words, excavation to a fixed size is reliably performed.

After this, the bucket is held at this depth D ₃ until it is hoisted in a fully closed state.

() Hoisting When the drum control valves 5 and 6 are operated to the operating position and both drums 1 and 2 are hoisted, the hoisting control circuit 25 is activated by the hoisting determination output from the hoisting/lowering determining circuit 22. The circuit 25 commands the modulating clutch 16 to determine the degree of engagement during hoisting by operating the modulating clutch lever 15, and the bucket is hoisted at a speed based on the commanded degree of engagement. After the bucket is hoisted and decelerated to a predetermined height, hoisting is stopped,
This completes one cycle of excavation work.

The operation of the bucket will be explained in more detail with reference to the flowchart shown in FIG.

After starting the work, first, in step _S1 , it is determined whether the setting/operation selector switch 19 is in the setting mode or the operation mode, and when the setting mode is determined, the process proceeds to step _S2.
Then, it is determined whether the degree of coupling _C2 of the modulating clutch 16 for stalling the bucket when the bucket stops lowering is set (whether or not the degree of coupling setting switch 20 is turned on), and YES.
Then, the degree of coupling C ₂ is read into the memory circuit 21 and stored (steps S ₃ and S ₄ ).

Next, in step _S5 , turn on the work condition setting switch 2.
3, lowering deceleration start depth D ₁ , lowering stop depth
After determining whether D ₂ , sinking grip stop depth D ₂ , and coasting correction amount α have been set, step
In _S6 , it is determined whether the setting/operation changeover switch 19 has been switched to the operation mode.

Once the operating mode is determined here, the first
The bucket lowering step starts, and the degree of engagement indicated by the modulating clutch lever 15 read in step _S7 is outputted to the modulating clutch 16 via the lowering control circuit 26 (step _S8 ). Then, while lowering the bucket, depth gauge 17
The bucket _depth based on the signal from the bucket is read (step _S9 ), and it is determined whether or not the bucket is in the lowered state (step _S10 ). It is determined whether or not the bucket has reached the lowering deceleration start depth _D2 . If it has not reached it, the process returns to step _S7 , and if it has reached it, the clutch engagement degree at that time is determined.
C ₁ is read into the lowering deceleration/stop control circuit 27,
stored (steps S ₁₂ , S ₁₃ ).

The lowering deceleration/stop control circuit 27 determines the degree of connection C according to the bucket depth d based on this clutch connection degree _C1 and a preset clutch connection degree _C2 for stopping the stall as follows: C=C ₁ + (C ₂ - C ₁ /D ₂ -D ₁ ) x (d - D ₁ ) (step S ₁₄ ), and the coupling degree C thus calculated is output to the modulating clutch 16 ( Step S ₁₅ ). In this way, the support drum 1 is gradually decelerated, and eventually the bucket stops stalling. During this time, the bucket depth is read (step _S16 ), and in step _S17 the bucket reaches the lowering stop depth.
When it is determined that D ₂ has been reached, step S ₁₈
Then, it is determined whether the lever switch 18 is turned on (whether the support drum control lever 5a is returned to the neutral position or not), and when the lever switch is turned on, that is, the support drum 1 is separated from the drive system. When it reaches a free rotation state, it enters the sinking and grasping stage.

At this time, modulate clutch lever 15
The commanded coupling degree is read into the sinking and gripping control circuit 28 (step _S19 ), and this commanded coupling degree is outputted to the modulating clutch 16 as a commanded coupling degree (step _S20 ). Freefall as the bucket closes. During this free descent, the bucket depth is read (step S ₂₁ ),
The lowering confirmation (step S ₂₂ ) is performed, and the
In _S23 , it is determined whether the depth at which the bucket coasting amount should be corrected has been reached. If YES here, the negative brake solenoid control valve 13 for the support drum
An activation signal is output (step _S24 ), and the negative brake 9 of the support drum 1 is activated to stop the bucket. Note that when it is determined in step _SS23 that the coasting correction depth has not been reached, the process returns to step _S19 .

After the bucket stops, it is determined in step _S25 whether the lever switch 18 has been turned off (or the support drum control lever 5a has been operated to the operating position).If YES, the hoisting operation is started.
The activation signal for the support drum negative brake electromagnetic control valve 13 is cut off (switch S ₂₆ ).

After that, the modulated clutch lever 15 reads the indicated degree of engagement (switch S ₂₇ ), and the sink grip control circuit 28 reads the commanded degree of engagement from the modulated clutch 16.
The bucket is hoisted while the command connection level is output (step _S28 ), and after the operator confirms the lift height of the bucket, hoisting is stopped.

Note that when bucket hoisting is determined in step _S10 and step _S22 , step
Moving to _S25 , hoisting operation is performed.

With the above steps, one cycle of work is completed. After that, on the condition that the hoisting stop is confirmed (step _S29 ), it is determined whether the work is completed or not based on whether the operator operates the power switch or not (step _S30 ), and then the second cycle of work continues. Steps to enter
The process moves from step _S30 to step _S31 . Here, the degree of clutch engagement C ₂ and the working conditions D ₁ for stopping the stall,
Whether or not to change the set values of D ₂ , D ₃ , and α is determined by the driver's operation or non-operation of the setting/operation selector switch 19, and if no changes are made, the step
Go to step _S7 , and if you want to change it, go to step _S1 .

〔Effect of the invention〕

As described above, according to the present invention, a command signal for decelerating and stopping the lowering is output to the modulating clutch from the time when the bucket depth reaches a preset lowering deceleration start depth, and the bucket depth When the machine reaches a preset depth for sinking and grabbing operation, it outputs a brake activation signal to the brake device, so that lowering deceleration, stopping, and sinking and grabbing stopping operations are performed automatically and accurately at the appropriate depth. be able to. Therefore, the operational burden on the driver is significantly reduced, and it is possible to carry out highly accurate sizing digging work that is not affected by the skill level of the driver.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a control system in a sizing excavation control device according to an embodiment of the present invention, Fig. 2 is a hydraulic operation circuit diagram of the same, and Fig. 3 is a flowchart for explaining bucket operation by the device. , FIG. 4 is a diagram for explaining the movement of the bucket during sizing digging work. 16...Modulate clutch, 15...Modulate clutch lever, 1...Support drum as a winch drum for driving the bucket, 2
... Opening/closing drum, 3... Clutch of support drum, 9... Negative brake as the brake device, 13... Electromagnetic control valve for the brake, 17...
Depth gauge, 19... Setting/operation changeover switch constituting a means for setting the degree of coupling of the modulate clutch;
20...Same setting switch, 21...Same memory circuit,
22...Hoisting/lowering discrimination circuit, 23...Work condition setting switch, 24...Depth discrimination circuit, 27...
Lowering deceleration/stop control circuit, 28... sinking grip control circuit.

Claims (1)

[Claims] 1. A torque converter equipped with a modulating clutch with variable coupling degree is installed in the drive system of the winch drum that drives the bucket cart up and down, and the coupling degree of the modulating clutch is controlled by operating the modulating clutch lever. a drum clutch that performs rotation control and speed control over each operation of lowering, lowering deceleration, lowering stop, and hoisting of the winch drum, and connects and separates the winch drum from a drive system; The drum clutch is equipped with a braking device that brakes the winch drum in the free fall area of the bucket when the winch drum is separated from the drive system, and the bucket is controlled by controlling the rotation of the winch drum from lowering rotation to stopping. Depending on the depth, lower the bucket,
The lowering deceleration and lowering stop operations are performed, and in the free fall area, the bucket is grabbed by sinking,
In a grab working machine configured such that the bucket hoisting operation is performed by the hoisting rotation of the winch drum after this sinking and grabbing operation, a depth gauge that detects the bucket depth and a hoisting operation of the winch drum are installed. connection degree setting storage means for setting and storing the degree of connection of the modulate clutch for the purpose of setting and storing the degree of connection of the modulating clutch; a working condition setting means for setting a traveling correction depth; a hoisting/lowering discrimination means for determining whether the bucket is hoisting up or lowering; and a bucket depth detected by the depth meter is determined by the working condition setting means. Depth determining means for determining whether or not each set depth has been reached; and a set coupling degree by the coupling degree setting storage means and a coupling degree instructed by the operation of the modulating clutch lever during the lowering deceleration and stopping operation of the bucket. a lowering deceleration/stop control circuit which outputs a degree of coupling command for lowering deceleration and lowering stop to the modulating clutch based on the depth attainment signal from the depth determining means; A fixed-size excavation control device for a grab working machine, characterized in that it comprises sinking and grabbing control means for outputting a brake activation signal to the brake device based on the depth reaching signal from the depth determination means.