JPH0460913B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an automatic constant speed control device for a winch.

B. Prior Art When carrying out ground improvement work by installing an auger unit such as a pile driver or crane, it is necessary to match the chemical injection speed with the hoisting/lowering speed of the auger unit in a low speed range. Conventionally, for such work, ultra-low-speed operations were performed using a hydraulic ultra-low-speed control device provided in the machine body.

However, since this conventional ultra-low speed control device does not provide any feedback on the rope speed, the rope speed changes due to changes in the drum winding layer of the hydraulic hoisting winch. For this reason, the operator sequentially controls the engine speed by operating the engine accelerator lever while looking at the speed meter on the rope installed separately, increasing or decreasing the rotation speed of the hydraulic pump, and hoisting by controlling the hydraulic pump discharge amount. The rope is controlled at a constant speed by adjusting the winch's rotational speed. Therefore, the operation is complicated and it is difficult to maintain a constant speed.

For this reason, a constant speed control device shown in FIG. 6 has conventionally been used. With this control device, construction speed
V _O is set by the setting device 51, and the hoisting rope speed V is detected by the speed detector 61. The automatic constant speed control device 50 uses an addition point 52 to calculate the deviation V _O −V (=ΔV) between the construction speed V _O set by the setting device 51 and the hoisting rope speed V detected by the speed detector 61. death,
This deviation ΔV is multiplied by the coefficient K in the coefficient unit 53 to obtain K・
Obtain ΔV. This K·ΔV is input to the integrator 54 and added to the previous control value P to obtain a new control value P. This control value P is input to the electromagnetic proportional pressure reducing valve 16. This electromagnetic proportional pressure reducing valve 16 adjusts the pressure guided to the regulator 1a of the hydraulic pump 1, and a pressure corresponding to the input control value P is applied to the regulator 1a. As a result, the discharge volume of the hydraulic pump 1 is controlled, and the hydraulic pump 1
The discharge flow rate of the hydraulic winch is adjusted to maintain the rotational speed of the hydraulic winch at a predetermined value.

C Problems to be Solved by the Invention Automatic constant speed control using this method is effective when speed fluctuations occur at the start of control or when disturbances occur due to irregular winding of the hoisting rope, fluctuations in engine speed, etc.
Because the speed deviation (ΔV mentioned above) is large, the response until convergence to the set construction speed V _O is very slow.
Speed hunting is also likely to occur.

In addition, this automatic constant speed control device is sometimes used as an ultra-low speed automatic constant speed control device for auger work on hard ground, etc., but in that case, the feeding speed of the auger unit and the digging speed match. Otherwise, the auger's hanging rope may become loose and the auger may become floating. At this time, when the hanging rope becomes loose, the detected speed shows a value smaller than the actual value or zero, and the speed deviation by the automatic constant speed control device becomes positive and a command value for speed increase is output. For this reason, the feed-out speed of the auger unit is increased even further, and not only is the ultra-low speed constant speed control not achieved, but the winch drum winds irregularly.

Furthermore, since the automatic constant speed control device described above does not automatically control the engine speed, if the engine speed is incorrectly set, the required discharge amount in the control range will not be obtained from the hydraulic pump, and the control will not be possible at all. There is a possibility that it will be impossible.

An object of the present invention is to provide an automatic constant speed control device for a winch that solves these various problems.

D. Means for Solving the Problems The automatic constant speed control device for a winch according to the present invention is for automatic constant speed control of the hoisting/lowering speed of a work attachment that is lifted by a winch mounted on a work machine body. The basic configuration is a speed setting device that sets the hoisting/lowering speed of the work attachment, a speed detector that detects the hoisting/lowering speed of the work attachment, and a speed detector that detects the hoisting/lowering speed of the work attachment, and a speed detector that detects the hoisting/lowering speed of the work attachment. The device is equipped with a deviation device that takes a deviation, and outputs a speed control value for controlling the hoisting/lowering speed based on this deviation.

In addition to this basic configuration, the invention of claim 1 further includes an initial control value generating means that generates an initial control value according to the set speed, and a feedback gain that generates a feedback gain according to the set speed. a multiplier that takes the product of the deviation and the feedback gain; an integrator that takes the integral value of the product; and a speed control value that adds the initial control value and the integral value. and an adder for generating.

In addition to the above-mentioned basic configuration, the invention of claim 2 also provides a load detector for detecting the lifting load of the winch, a reaction force detection means for detecting the excavation reaction force by the work attachment, and a reference that the actual speed is close to zero. A speed determining means for determining that the lifting load is lower than the speed, a lifting load determining means for determining that the lifting load is smaller than a reference lifting load that is close to zero, and a reaction force that determines that the excavation reaction force is larger than a predetermined value. The winch is provided with a determining means and a stopping means for stopping the winch when each of the three determining means determines each condition.

Further, in the invention according to claim 3, the winch having the above-mentioned basic configuration is a hydraulic winch. This hydraulic winch consists of a variable displacement hydraulic pump driven by an engine, and a hydraulic motor driven by pressure oil from the variable displacement hydraulic pump to drive the winch.
The winch speed is controlled by controlling the displacement of the variable displacement hydraulic pump and adjusting the discharge amount of the hydraulic pump based on the deviation between the set speed and the actual speed. In addition to this configuration, claim 3
The invention includes upper and lower limit value detection means that respectively detect when a speed control value reaches a predetermined upper and lower limit value and output an upper limit value signal and a lower limit value signal, and a means that responds to each output of the upper and lower limit value signals. and warning means for respectively issuing a warning to the effect that the engine speed should be increased or decreased.

E. Effect - Invention of Claim 1 - The initial control value generating means generates an initial control value according to the set speed. This initial control value is summed with the output of the integrator in an adder to form the speed control value. At the start of control, the integral value is zero, but since the speed control value is formed according to the initial control value,
The winch is quickly driven at the planned construction speed. During work, the deviation between the set speed and the actual speed is calculated, the feedback gain corresponding to the set speed is multiplied by this deviation, the product is integrated, and the initial control value and the integral are further integrated. The speed control value is generated by adding the values, so even if the actual speed fluctuates greatly due to disturbance, the actual speed quickly converges to the set speed due to the feedback gain that takes the value according to the set speed. do.

- Invention of Claim 2 - Each determination means determines that the actual speed is slower than the reference speed which is close to zero, the lifting load is smaller than the reference lifting load which is close to zero, and the excavation reaction force is larger than a predetermined value. If determined, the stop means stops the winch, thereby preventing the work attachment from floating out of control or causing wild winding.

- Invention of Claim 3 - The speed of the hydraulic winch is controlled by controlling the displacement of the variable displacement hydraulic pump and adjusting the discharge amount of the hydraulic pump based on the deviation between the set speed and the actual speed. When it is detected that the speed control value calculated based on the deviation device has reached the predetermined upper and lower limit values, the alarm means issues a warning to increase or reduce the engine speed. Emitted. This warning allows the operator to set the speed by increasing or decreasing the engine speed.

F Example - First Example - A first example will be described based on FIGS. 1 and 2.

First, the hoisting winch hydraulic circuit will be explained with reference to FIG. In FIG. 2, reference numeral 1 denotes a variable displacement hydraulic pump (hereinafter simply referred to as a hydraulic pump) driven by an engine (not shown). On the discharge side of the hydraulic pump 1, there is a directional control valve 2 and a circuit for switching and controlling the discharged oil. A relief valve 3 for setting pressure is provided. The directional control valve 2 is connected to conduits 5 and 6 that communicate with the hoisting hydraulic motor 4, and a counterbalance valve 7 is installed in the conduits 5 and 6. The pilot ports 2a, 2b of the directional control valve 2 are supplied with secondary pressure according to the amount of operation of the pilot valve 11 which adjusts the discharge pressure of the pilot hydraulic pump 8.
The direction switching valve 2 is controlled by the supply pressure to control the direction and flow rate of the pressure oil to the hydraulic motor 4. Further, the output pressure of the pilot valve 11 is transferred to the pipe line 1 via the shuttle valve 12.
3, and the electromagnetic switching valve 1 provided in this conduit 13.
4, it can also be supplied to the regulator 1a of the hydraulic pump 1.

Further, oil discharged from the pilot hydraulic pump 8 can be supplied to the regulator 1a via an electromagnetic proportional pressure reducing valve 15, a conduit 16, and an electromagnetic switching valve 14. This electromagnetic proportional pressure reducing valve 15 is driven by a command signal from an automatic constant speed control device 30,
Its output pressure is adjusted. That is, the electromagnetic switching valve 14 is switched to the A position when the switch 17 is turned on, and is switched to the B position when the switch 17 is turned off. In the A position, the output pressure of the electromagnetic proportional pressure reducing valve 15 is supplied to the regulator 1a, and in the B position, the output pressure of the pilot valve 11 is supplied to the regulator 1a.
The switch 17 is installed between the battery 18 and the solenoid section of the electromagnetic switching valve 14. moreover,
In order to detect the operating direction of the pilot valve 11, pressure switches 19a and 19 are connected to the pilot lines 9 and 10.
9b is provided.

Further, in FIG. 2, a winch drum 21 is connected to a hydraulic motor 4, and this winch drum 21
A rope 22 wound around supports an auger unit 24 via a sheep 23. The sheep 23 is provided with a speed detector 25 such as a rotary encoder to detect the speed of the rope 22.

Furthermore, in FIG. 2, automatic constant speed control device 3
0 includes a speed setting device 31, and receives signals from the speed detector 25 and pressure switches 19a and 19b to control the hoisting rope speed V to the construction speed V _O set by the speed setting device 31. , sends a command signal to the electromagnetic proportional pressure reducing valve 15 as described below.

Next, the automatic constant speed control device 30 of the first embodiment will be explained with reference to FIG.

The automatic constant speed control device 30 includes a speed setting device 31
, a function generator 32, an addition point 33, and a multiplier 3
4, an integrator 35, an addition point 36, and a gate circuit 37. The speed setting device 31 sets the construction speed V _O
Set. The function generator 32 is the speed setter 31
A function is generated that associates the construction speed V _O set and inputted with the standard control value P _O , which is the input current to the electromagnetic proportional pressure reducing valve 15, as shown by the solid line in FIG. 3a. Further, a function is generated in which the construction speed V _O is associated with the slope of the function shown by the third solid line as shown by the solid line in FIG. 3b. That is,
Standard control value P _O for input construction speed V _O
and feedback gain G are output.

The addition point 33 is the deviation V _O −V between the hoisting rope speed V output from the speed detector 31 and the construction speed V _O
= ΔV is obtained. Multiplier 34 multiplies feedback gain G and deviation ΔV. The integrator 35 is
The multiplier G·ΔV is integrated and a control value P is output. The addition point 36 adds the standard control value P _O from the function generator 32 and the control value P from the integrator 35 to obtain a new control value P. The gate circuit 37 closes when the pressure switch 19 is turned on, and supplies the control value P, which is the output of the adder 36, to the electromagnetic proportional pressure reducing valve 15 as a command signal.

Next, the operation will be explained.

The operator turns on the switch 17 and the solenoid switching valve 1
Switch 4 to the A position to select automatic constant speed operation. Next, the construction speed _VO of the auger unit 24 is planned and set by the speed setting device 31 provided in the automatic constant speed control device 30. The operating lever 11a of the hoisting winch is fully operated to either the hoisting up side or the hoisting down side to detent-lock the operating lever 11a. At this time, the regulator 1 of the hydraulic pump 1
Since no pressure oil is supplied to a, the pump discharge amount is zero. The pilot valve 11 is operated by operating the lever 11a, the pressure switch 19 is closed, and a control start signal is input to the automatic constant speed control device 30. When the control start signal is input, the gate circuit 37 is closed. When control is started with the gate closing operation, a standard control value P _O corresponding to the planned construction speed V _O is output from the function generator 32 and added to the addition point 36 . Since one input of the addition point 36 is zero at the start of control, this standard control value (indicating the input current value) P _O is sent to the electromagnetic proportional pressure reducing valve 15 via the gate circuit 37 . This command signal is switched to secondary pressure by the electromagnetic proportional pressure reducing valve 15, and this pressure is input to the regulator 1a of the hydraulic pump 1. As a result, the displacement volume of the hydraulic pump 1 increases from zero and starts discharging pressure oil, which is guided to the hydraulic motor 4 through the directional control valve 2, and the winch drum 21 starts rotating. Then, when the speed detector 25 receives a signal corresponding to the speed of the hoisting rope 22, that is, the hoisting rope speed V, the addition point 33 calculates V _O −V (=ΔV), and this deviation ΔV and the function generator It is multiplied by the feedback gain G output from 32 in accordance with the construction speed V _O and is input to an integrator 35 . The integrator 35 integrates G·ΔV and outputs a control value P. The addition point 36 adds the standard control value P _O from the function generator 32 and the control value P from the integrator 35,
A command signal (input current value) P, which is the result of the addition, is supplied to the electromagnetic proportional pressure reducing valve 15 via the gate circuit 37. As a result, a secondary pressure corresponding to the command signal is output from the electromagnetic proportional pressure reducing valve 15, and the pipe line 1
6. It is supplied to the regulator 1a via the electromagnetic switching valve 14. As a result, the displacement volume of the hydraulic pump 1, that is, the discharge flow rate is increased or decreased in accordance with the deviation ΔV, so the rotation speed of the winch drum 21 is controlled, and the hoisting rope speed V approaches the construction speed V _O.

As described above, at the start of control, the output of the integrator 35 is zero, but the standard control value P _O is output from the function generator 32.
is output, so the addition point 36 is its control value
P _O is sent to the electromagnetic proportional pressure reducing valve 15. Therefore,
Responsiveness at rise is improved. After starting, the control value P is corrected by the speed deviation ΔV as follows: P=P _O +∫G·ΔVdt.

The feedback gain G mentioned above will now be explained. Now, as shown in Figure 3a, the planned construction speed V _O is V _A and the hoisting rope speed V is V _B (>V _A ).
shall be. Planned construction speed V _O = Control value P for V _A
is P _A , control value P for hoisting rope speed V=V _B
is P _B. In other words, the hoisting rope speed V is V _B →
To reduce the value to V _A , the control value P should be lowered from P _B to P _A. The speed deviation ΔV _AB between speeds V _A and V _B and the control value deviation ΔP _AB between control values P _A and P _B are expressed as: V _B −V _A = ΔV _AB >0 V _B −P _A = ΔP When _AB > ₀ , the control value P _A can be expressed as PA = P _B - ΔP _AB = P _B - (ΔV _AB ·G) (1). Therefore, in order to determine the feedback gain G so that this equation (1) is satisfied in the entire region of Fig. 3a, the feedback gain G
can be made into the slope of the function shown in Figure 3a, and the feedback gain G can be changed to the construction speed as shown in Figure 3b.
It can be expressed as a function of V _O. In other words, the third
The function in Figure b represents the slope of the function shown in Figure 3a. Further, the function is determined corresponding to the P-Q line of the hydraulic pump 1.

Note that, for example, if the actual speed is zero for a certain period of time or more, or if both pressure switches 19a and 19b are on, it may be determined that there is an abnormality and the gate circuit 37 may be opened. This will stop the winch. When the abnormal condition is resolved, the winch starts driving again, but in this case, the initial control value
Since P _O is output, it is possible to drive at the set speed immediately.

-Second Embodiment- The engine rotation speed warning device shown in FIG. 4 can be incorporated into the device described above.

This alarm device consists of two comparators 41, 42 and 2.
It has two alarm output devices 43 and 44. The reference value of the comparator 41 is set to the minimum control value P _MIN , the reference value of the comparator 42 is set to the maximum control value P _MAX , and the compared values are the control value P supplied to the electromagnetic proportional pressure reducing valve 15 . The comparator 41 indicates that the control value P is the minimum control value.
When it is smaller than P _MIN , a warning signal is sent to the engine speed reduction warning output device 43, and the warning output device 43 is driven. This alarm output device 43 can be composed of a buzzer or a lamp, and the buzzer sounds or the lamp lights up when P≦P _MIN . On the other hand, when the control value P is larger than the maximum control value P _MAX , the comparator 42 sends a warning signal to the engine speed increase warning output device 44, and drives the warning output device 44, which includes a buzzer and a lamp. When P≧P _MAX , a buzzer sounds or a lamp lights up.

In other words, if P≦P _MIN , the hoisting rope speed V≦ even if the hoisting rope speed V is greater than the construction speed V _O and the control value P is reduced to its minimum value P _MIN .
The construction speed is not V _O , and if the engine speed is lowered, the hoisting rope speed V can be adjusted to the construction speed.
This alerts the operator to lower the engine speed as it can approach V _O. On the other hand, when P≧P _MAX , the hoisting rope speed V is smaller than the construction speed V _O and even if the control value P is increased to its maximum value P _MAX , the hoisting rope speed V ≧ construction speed V _O is not achieved. Since the hoisting rope speed V can be brought closer to the construction speed V _O by increasing the engine speed, the operator is warned to increase the engine speed.

-Third Embodiment- Next, a floating warning device for the auger unit 24 will be explained with reference to FIG.

This uplift alarm device requires that the hoisting rope speed V is V≦υ with respect to an arbitrary reference speed υ close to zero, and that the lifting load W of the hoisting rope 22 is equal to an arbitrary reference lifting load _WO close to zero. For any reference reaction force R _O where the zero point reaction force (for example, the total weight of the auger unit 24 - the weight lifted during excavation work) R is close to zero, R ≧ R _{O ,} that is. When the following three conditions are satisfied: the excavation reaction force is a certain value or more, the alarm device 71 is activated to warn of uplift, and the gate circuit 37 is opened to stop the winch drum 21.

For this reason, this uplift alarm device: ) Compares the hoisting rope speed V and an arbitrary reference speed υ close to zero stored in a memory (not shown) in magnitude using a comparator 72, If ≦υ, send a “1” signal to the AND gate 73, and if V>υ, send a “0” signal.
Input the signal.

) The hanging load W is detected by the load detector 74,
A comparator 75 compares an arbitrary reference hanging load W _O close to zero value with the hanging load W, and if W≦W _O , it sends a “1” signal to the logical multiplier 73, and if W>W _O , it sends a “0” signal. ” signal.

) The reaction force value R is expressed as the difference between the total weight value W _R of the auger unit 24 and the hanging load W during excavation work, based on the total weight value W _R of the auger unit 24. Therefore, the total weight value W _R with the auger unit 24 completely separated from the ground is stored in the storage device 76. When the excavation work is started, the deviation W _R -W between the load value W _R and the hanging load W is determined at the addition point 77.
This deviation is the reaction force value R. In other words, if the ground is hard and the digging speed is slow relative to the lowering speed, the hanging load W will be small and the reaction force value R will be large. This reaction force value R is input to a comparator 78 and compared with a reference reaction force R _O which is close to zero value. As a result, if R≧R _O , a “1” signal is input to the logical multiplier 73, and if R<R _O , a “0” signal is input to the AND device 73.

The logical multiplier 73 performs logical product processing on the signal values input in the above), ), ), and if the result is "1", it is determined that the auger unit 24 is floating, and the auger unit Alarm device 71 consisting of 24 floating alarms, lamps, buzzers, etc.
At the same time, the gate circuit 37 is opened to stop the winch drum 21.

G. Effects of the Invention According to the invention of claim 1, since the initial control value and feedback gain corresponding to the set speed are output, the speed converges to the predetermined set speed at the start of work or when the speed fluctuates due to disturbance. The time it takes to do so is shortened and responsiveness is improved. Hunting is also prevented.

According to the invention of claim 2, since a warning is given of the maladaptive state of the engine speed, even if the engine speed is incorrectly adjusted, it can be noticed immediately, and if the engine speed is adjusted, the work attachment can be reliably maintained at a constant speed. Can be driven.

According to the third aspect of the invention, since the winch stops when the work attachment lifts up, irregular winding is prevented and speed control is prevented from becoming impossible.

[Brief explanation of the drawing]

1 to 3 illustrate a first embodiment in which the automatic constant speed control device according to the present invention is applied to a hydraulic winch, and FIG. 1 is an overall block diagram thereof, and FIG. The overall configuration diagram including the circuit, and FIGS. 3a and 3b are diagrams explaining the functions of the function generator. FIG. 4 is a block diagram showing an embodiment of the second embodiment of the engine speed warning device.
FIG. 5 is a block diagram showing an embodiment of the third embodiment of the auger lifting warning device. FIG. 6 is a block diagram showing a conventional automatic constant speed control device. 1: Hydraulic pump, 1a: Regulator, 2: Directional switching valve, 4: Hydraulic motor, 8: Pilot hydraulic pump, 11: Pilot valve, 14: Solenoid switching valve, 15: Solenoid proportional pressure reducing valve, 17: Selection switch, 19a, 19b: pressure switch, 21: winch drum, 22: rope, 23: speed detector,
24: Auger unit, 30: Automatic constant speed control device, 31: Speed setter, 32: Function generator, 3
3: Addition point, 34: Multiplier, 35: Integrator, 3
6: Addition point, 37: Gate circuit.

Claims (1)

[Scope of Claims] 1. A device in which a work attachment is suspended from a winch mounted on a work machine body, and that automatically controls the hoisting/lowering speed of the work attachment at a constant speed, Up/
A speed setting device for setting a lowering speed, a speed detector for detecting the lifting/lowering speed of the work attachment, and a deviation device for detecting the deviation between the set speed and the actual speed. In the automatic constant speed control device for a winch, which outputs a speed control value for controlling the hoisting/lowering speed based on the set speed, initial control value generating means generates an initial control value according to the set speed. and a feedback gain generating means for generating a feedback gain according to the set speed, a multiplier that takes the product of the deviation and the feedback gain, and an integrator that takes the integral value of the product. An automatic constant speed control device for a winch, comprising: an adder that adds the initial control value and the integral value to generate the speed control value. 2 A device in which a work attachment is suspended from a winch mounted on a work machine body, and that automatically controls the hoisting/lowering speed of the work attachment at a constant speed,
A speed setting device for setting a lowering speed, a speed detector for detecting the lifting/lowering speed of the work attachment, and a deviation device for detecting the deviation between the set speed and the actual speed. The automatic constant speed control device for a winch that controls the hoisting/lowering speed based on the winch includes: a load detector that detects a lifting load of the winch; a reaction force detection means that detects an excavation reaction force caused by the work attachment; , speed determining means for determining that the actual speed is slower than a reference speed that is close to zero; lifting load determining means that determines that the lifting load is smaller than a reference lifting load that is close to zero; and the excavation reaction force. an automatic winch comprising: a reaction force determining means for determining that is larger than a predetermined value; and a stopping means for stopping the winch when each of these three determining means determines each condition. Constant speed control device. 3 A work attachment is suspended from a winch mounted on the work machine body, and includes a variable displacement hydraulic pump driven by an engine, and a hydraulic motor driven by pressure oil from the variable displacement hydraulic pump to drive the winch. A hydraulic winch speed control device comprising: a speed setting device for setting the hoisting/lowering speed of the work attachment; a speed detector for detecting the hoisting/lowering speed of the work attachment; The winch is automatically controlled by controlling the displacement of the variable displacement hydraulic pump and adjusting the discharge amount of the hydraulic pump based on the deviation. In a speed control device, upper and lower limit value detection means detect that the speed control value reaches predetermined upper and lower limit values and output an upper limit value signal and a lower limit value signal; and each output of the upper and lower limit value signals. an automatic constant speed control device for a winch, comprising warning means for respectively issuing a warning to the effect that the engine speed should be increased or decreased in response to each of the above.