JP2006290561A - Crane operating control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crane operation control device capable of inhibiting the increase of strange feeling and noise caused by engine noise change according to the weight of a hoisting load and capable of continuing stable working. <P>SOLUTION: The crane operation control device controls operating oil with a control vale 16, which oil is supplied to an actuator from variable displacement pumps 13, 14 driven by an engine 12 in a working machine equipped with a working device on a machine body. The control valve 16 is pilot-operated with pilot pressure generated when an operator operates control valves 24, 25. An electromagnetic proportional pressure reducing valve 30 is provided in a pilot initial pressure passage 15a for supplying common pilot initial pressure to the plurality of pilot valves 24, 25. When the working device is used for crane operation, a controller 26 depressurization-controls the pilot initial pressure by the electromagnetic proportional pressure reducing valve 30 and thereby depressurization-controls also the pilot pressure to the control valve 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a crane work control device that controls a work speed when crane work is performed by a work device of a work machine.

In a crane operation in which a suspended load is lifted and transferred by a hydraulic excavator, a crane operation mode is provided to limit the engine speed according to the crane operation in order to ensure the safety of the operation. Furthermore, in order to improve operability, the engine speed is reduced in response to the load of the suspended load. When the load of the suspended load increases, the engine speed is decreased and stable crane work can be performed. (For example, refer to Patent Document 1).
JP 2003-118975 A (first page, FIG. 1)

  However, in the above-described conventional technology, the engine speed is lowered according to the load of the suspended load.

  When the load of the suspended load increases, the engine load during crane operation increases, but the engine speed is decreased so that the operating speed of the actuator can be kept small. It is difficult to continue stable work.

  Since the engine speed changes every time the suspended load changes, the engine noise also changes, giving the operator and surrounding workers a sense of incongruity, and increasing the engine noise according to the suspended load. There's a problem.

  The present invention has been made in view of the above points, and by preventing fluctuations in the engine speed due to the load of the suspended load, it is possible to prevent a sense of incongruity and an increase in noise due to a change in engine noise corresponding to the load of the suspended load. An object of the present invention is to provide a crane work control device capable of continuing stable work while being able to do so.

  The invention according to claim 1 is generated by operating a control valve for controlling a working fluid supplied to an actuator from a main pump driven by an engine of a work machine having a work device in the machine body, and operated by an operator of the work machine. A crane comprising a pilot valve that pilot-operates a control valve with a pilot pressure, a pressure reducing valve that can reduce the pilot pressure, and a controller that controls the pressure reduction with the pressure reducing valve when the working device is used for crane work. It is a work control device.

  According to a second aspect of the present invention, the pressure reducing valve in the crane work control apparatus according to the first aspect is provided in a pilot original pressure passage for supplying a common pilot original pressure to a plurality of pilot valves.

  According to a third aspect of the present invention, there is provided a control valve for controlling a working fluid supplied to an actuator from a variable displacement pump driven by an engine of a work machine having a work device in the airframe, and a variable displacement pump to a control valve. A crane work control apparatus comprising pump discharge flow control means for controlling a pump discharge flow to be supplied, and a controller for reducing pump discharge flow by the pump discharge flow control means when the work apparatus is used for crane work.

  According to a fourth aspect of the present invention, the pump discharge flow rate control means in the crane work control device according to the third aspect is negatively drawn from the displacement variable means for variably controlling the displacement of the variable displacement pump and the center bypass passage of the control valve. A negative control pressure passage for guiding the control pressure to the displacement variable means, a shuttle valve provided in the negative control pressure passage, and a control for pump displacement control as an alternative to the negative control pressure for the displacement variable means by the shuttle valve And a solenoid valve for supplying pressure.

  According to a fifth aspect of the present invention, the controller in the crane work control device according to any one of the first to fourth aspects includes a load detection means for detecting a load of a suspended load suspended from the work device, and a load of the suspended load. And a work speed limiting means for performing a calculation for limiting the work speed accordingly.

  According to a sixth aspect of the present invention, the controller in the crane work control device according to any one of the first to fourth aspects includes a turning radius detecting means for detecting a turning radius of the suspended load, and a work speed according to the turning radius of the suspended load. Working speed limiting means for performing a calculation for limiting the above.

  According to a seventh aspect of the present invention, the controller in the crane work control device according to any one of the first to fourth aspects includes a load detection means for detecting the load of the suspended load suspended from the work device, and a turning radius of the suspended load. And a working speed limiting means for performing a calculation for limiting the working speed in accordance with both the load of the suspended load and the turning radius.

  According to an eighth aspect of the present invention, in the crane work control device according to the fifth or seventh aspect of the present invention, the crane work control device includes a switching operation device that is operated by an operator to switch between the suspension work mode and the empty work mode, and the controller is detected by the load detection means. A load determination device that determines whether or not there is a load on the suspended load, and a restriction that releases the restriction on the work speed by the work speed limiting means only when the operator switches the switching operation device to the empty work mode under the condition that there is no load on the suspended load And release means.

  The invention described in claim 9 is such that the load determination device in the crane work control apparatus described in claim 8 determines that there is a load when the load of the suspended load is equal to or greater than a certain value.

  According to a tenth aspect of the present invention, the work speed limiting means of the controller in the crane work control device according to any of the seventh to ninth aspects is such that the speed coefficient according to the load of the suspended load and the speed according to the turning radius of the suspended load. A multiplier for setting the work speed coefficient by multiplying the coefficient is provided, and the pilot pressure is controlled to be reduced according to the work speed coefficient set by the multiplier.

  According to the eleventh aspect of the present invention, the work speed limiting means of the controller in the crane work control device according to any of the seventh to ninth aspects is such that the speed coefficient according to the load of the suspended load and the speed according to the turning radius of the suspended load. A minimum value selector that sets a work speed coefficient by selecting a minimum value of the coefficient is provided, and the pilot pressure is controlled to be reduced according to the work speed coefficient set by the minimum value selector.

  According to the first aspect of the invention, when the working device is used for crane work, the controller controls the pressure reduction of the pilot valve for piloting the control valve by the pressure reducing valve, thereby changing the engine speed. Therefore, it is possible to prevent a sense of incongruity or an increase in noise due to a change in engine noise according to the load of the suspended load, and it is possible to continue stable work in a stable engine speed range.

  According to the second aspect of the present invention, the common pilot source pressure supplied to the plurality of pilot valves is controlled by the pressure reducing valve in the pilot source pressure passage so that the pilot pilot pressure is output from the plurality of pilot valves to the control valve. It is possible to control the pilot pressure of multiple systems at the same time, and to reduce the number of parts.

  According to the invention of claim 3, when the working device is used for crane work, the controller controls the pump discharge flow rate supplied from the variable displacement pump to the control valve to be reduced by the pump discharge flow rate control means. Since the actuator speed is limited without changing the engine speed, it is possible to prevent a sense of incongruity and an increase in noise due to changes in engine noise according to the load of the suspended load, and it is stable in a stable engine speed range. Can continue to work.

  According to the fourth aspect of the present invention, the shuttle valve is provided in the negative control pressure passage drawn from the center bypass passage of the control valve, and the variable displacement type is provided via the shuttle valve from the electromagnetic valve of the pump discharge flow rate control means. Since the control pressure for controlling the pump capacity is supplied to the pump capacity varying means, the pump discharge flow rate controlling means can be easily configured by effectively utilizing the existing negative control system equipment.

  According to the fifth aspect of the present invention, as the load of the suspended load detected by the load detecting means increases, the working speed is strongly restricted by increasing the pilot pressure reduction control by the working speed limiting means. Stable work can be continued by suppressing the fluctuation of

  According to the sixth aspect of the present invention, as the turning radius of the suspended load detected by the turning radius detecting means increases, the working speed is strongly restricted by increasing the pilot pressure reduction control by the working speed limiting means. Stable work can be continued by suppressing the peripheral speed during turning of the load to be constant.

  According to the seventh aspect of the present invention, as the load of the suspended load detected by the load detecting means increases and the turning radius of the suspended load detected by the turning radius detecting means increases, the work speed limiting means increases the pilot. By strengthening the pressure reduction control and restricting the work speed strongly, it is possible to suppress the swing of the suspended load and to suppress the peripheral speed when the suspended load turns, so that stable work can be continued.

  According to the eighth aspect of the invention, the restriction on the working speed is released by the restriction releasing means only when there is no load of the suspended load and the operator operates the switching operation device. It is possible to prevent the restriction of the work speed from being released, and when the operator operates the switch, the work speed restriction is released when the load of the suspended load is eliminated, so that the next work can be quickly performed. Can be migrated to.

  According to the ninth aspect of the present invention, when the load of the suspended load is equal to or greater than a certain value, the load determination device determines that there is a load and regards it as a suspension operation. This makes it possible to perform stable crane work.

  According to the invention of claim 10, the work speed coefficient set by multiplying the speed coefficient according to the load of the suspended load by the multiplier and the speed coefficient according to the turning radius of the suspended load is the load increase of the suspended load. The pilot pressure is synergistically controlled to reduce the swirl radius of the suspended load, so that more stable work can be performed.

  According to the invention of claim 11, the work speed coefficient set by selecting the minimum value of the speed coefficient according to the load of the suspended load and the speed coefficient according to the turning radius of the suspended load by the minimum value selector is: Since the pilot pressure is controlled to be reduced in relation to the greater influence of the increase in the load of the suspended load or the increase in the turning radius of the suspended load, stable work can be ensured.

  Hereinafter, the first embodiment shown in FIGS. 1 to 7, the second embodiment shown in FIGS. 8 and 9, and the third embodiment shown in FIG. 10 will be described. Details will be described with reference to FIG.

  First, the first embodiment shown in FIGS. 1 to 7 will be described.

  FIG. 2 shows a hydraulic excavator A as a construction machine or a work machine. An upper swing body 1b is turnably provided on a lower traveling body 1a to form a body 1. The upper swing body 1b of the body 1 has a work device. 2 is installed.

  In this working device 2, the base end of the boom 3 is pivotally supported by a coupling pin 3P so as to be swingable in the vertical direction, and an arm 4 is pivotally supported by a coupling pin 4P at the distal end of the boom 3. A bucket 5 is pivotally supported by a connecting pin 5P at the tip of the boom, and a boom cylinder 3a as an actuator for raising and lowering the boom 3 is provided between the upper swing body 1b and the boom 3, and the boom 3 is provided with an arm cylinder 4a as an actuator for rotating the arm 4, and a back surface of the arm 4 is provided with a bucket cylinder 5a as an actuator for rotating the bucket 5.

  A suspension tool 6 is pivotally connected to the back surface of the bucket 5, and a hook 6 a is attached to the tip of the suspension tool 6, and a suspended load 7 is suspended by the hook 6 a.

  On the head side and the rod side of the boom cylinder 3a, a head pressure detector 8 for detecting the pressure in the head side chamber, that is, the head pressure, and a rod pressure detector 9 for detecting the pressure in the rod side chamber, that is, the rod pressure, are provided. A boom angle detector 10 that detects the angle of the boom 3, that is, the boom angle, is provided on the coupling pin 3P at the base end of the boom 3, and an arm angle that detects the arm angle, that is, the arm angle, is provided on the coupling pin 4P of the arm 4. A detector 11 is provided.

  FIG. 1 shows a system configuration diagram, and variable displacement pumps 13 and 14 as a main pump and a pilot pressure pump 15 are connected to a drive shaft of the engine 12. The variable displacement pumps 13 and 14 are variable displacement pumps that variably control the pump displacement by variably controlling the tilt angle of the swash plate by regulators 13r and 14r serving as variable displacement means that receives the control pressure. Connected to these variable displacement pumps 13 and 14 is a control valve 16 that controls the direction and flow rate of the hydraulic fluid pressurized and supplied from the variable displacement pumps 13 and 14.

  Inside the control valve 16, spools 17 and 18 that are stroke-controlled by pilot pressure supplied to one end surface and the other end surface are provided corresponding to each actuator (in FIG. 1, spools corresponding to the arm cylinder 4a). Only the details are shown), and the operation of each actuator of the hydraulic excavator is controlled by the hydraulic oil whose direction and flow rate are controlled by the spools 17 and 18. In other words, the boom cylinder 3a, the arm cylinder 4a, and the bucket cylinder 5a are controlled to extend and retract, and the traveling motors 19 and 20 as actuators for driving the left and right crawlers of the lower traveling body 1a and the upper swinging body 1b are swung. Each forward / reverse operation of the turning motor 21 as an actuator to be driven is controlled.

  The spools 17 and 18 in the control valve 16 are displaced by receiving pilot pressure supplied from the pilot passage 22 at one end and the other end, respectively. These pilot passages 22 are pilots operated by an operator of the work machine. The output unit of the controller 23 is communicated.

  The pilot operating device 23 includes a plurality of pilot valves (remote control valves) 24 and 25 that can be operated by a single operating lever. These pilot valves 24 and 25 are supplied with pilot original pressure, that is, pilot 1 from the pilot pressure pump 15. When the secondary pressure is supplied, the pilot secondary pressure generated according to the operation amount by lever operation is output to one end or the other end of each spool 17, 18 of the control valve 16 through the pilot passage 22. , 18 is displaced.

  On the input side of the controller 26 mounted on the work machine, a head pressure detector 8 that detects the head pressure of the boom cylinder 3a, a rod pressure detector 9 that detects the rod pressure, and a boom angle detector 10 that detects the boom angle. The arm angle detector 11 for detecting the arm angle is connected, the crane mode switch 27 for switching the normal work mode such as excavation to the crane work mode, the suspension work mode and the empty work operated by the operator in the crane work mode. A reset switch 28 is connected as a switching operation device for switching between modes. The reset switch 28 outputs “0” in the suspension work mode, and outputs “1” in the idle work mode.

  The output side of the controller 26 is connected to an engine speed control unit that controls the speed of the engine 12, a monitor 29 that outputs a crane work content and an alarm, and an electromagnetic proportional pressure reducing valve 30 as a pressure reducing valve. . The electromagnetic proportional pressure reducing valve 30 is provided in a pilot original pressure passage 15a for supplying a common pilot original pressure, that is, a pilot primary pressure, to the pilot valves 24 and 25 from the pilot pressure pump 15. It is also possible to install in the pilot passage 22 that outputs pressure.

  When the work device 2 is used for crane work, the controller 26 supplies a control current to the solenoid of the electromagnetic proportional pressure reducing valve 30, and the electromagnetic proportional pressure reducing valve 30 generates a pilot primary pressure, ie, a pilot original pressure, as a pilot pressure. Reduce pressure.

  In the control valve 16, center bypass passages 33 and 34 branched from hydraulic oil supply passages 31 and 32 communicated with an external pump discharge passage communicate with each other through a plurality of spools 17 and 18 in a neutral position. The orifices 35 and 36 for generating a negative control pressure for pump flow rate control (hereinafter simply referred to as “negative control pressure”) and a relief valve (hereinafter referred to as “the negative control pressure”) are formed at the rear ends of these center bypass passages 33 and 34. "Negative control relief valves 37, 38") are provided respectively, and communicated with the tank T through these orifices 35, 36 and negative control relief valves 37, 38.

  Negative control pressure passages (hereinafter simply referred to as “negative control pressure passages”) 39 and 40 for taking out the negative control pressure from the positions immediately before the orifices 35 and 36 of the center bypass passages 33 and 34 and the negative control relief valves 37 and 38, are branched. These negative control pressure passages 39, 40 are connected to the regulators 13r, 14r of the variable displacement pumps 13, 14, and give the negative control pressure for variably controlling the swash plate tilt angle to the regulators 13r, 14r. In order to stop the actuators 3a, 4a, 5a, 19, 20, and 21, the closer the spools 17 and 18 are to the neutral position, the larger negative control pressure is generated in the negative control pressure passages 39 and 40, and the higher the negative control pressure is, the regulator 13r and 14r control the swash plate tilt angle to be small, and control to reduce the pump discharge flow rate.

  As shown in FIG. 3, the controller 26 includes a storage device 41 that stores member information (such as the length between the connecting pins, the mass, and the mass center position) regarding the boom 3, the arm 4, the bucket 5, and the like of the work device 2. Is provided.

  Further, the controller 26 detects member information relating to the working device 2, the head pressure of the boom cylinder 3a detected by the head pressure detector 8, the rod pressure of the boom cylinder 3a detected by the rod pressure detector 9, and the boom angle detection. A load calculator 42 for calculating the load of the suspended load 7 is provided from the boom angle detected by the device 10 and various detection information of the arm angle detected by the arm angle detector 11.

  Further, the controller 26 determines the turning radius of the working device 2 from the member information related to the working device 2, the boom angle detected by the boom angle detector 10, and various detection information of the arm angle detected by the arm angle detector 11. A turning radius calculator 43 is provided for calculating.

  Connected to the load calculator 42 is a load determiner 44 that determines whether or not there is a load on the suspended load 7, and outputs “0” when the suspended load 7 is present and outputs “1” when the load disappears. Has been. The load determination unit 44 determines that there is a load when the load of the suspended load 7 is a certain value or more.

  Connected to the load calculator 42 is a data table 45 that sets the speed coefficient K1 to be smaller as the load increases. Further, the turning radius calculator 43 is connected to a data table 46 for setting the speed coefficient K2 to be smaller as the turning radius increases.

  An AND operation unit 47 that performs a logical product operation of the output of the reset switch 28 and the output of the load determination unit 44 is connected to the output unit of the reset switch 28 and the load determination unit 44, and the output unit of each data table 45, 46. Output the work speed coefficient K set by multiplying the speed coefficient K1 set according to the load of the suspended load 7, that is, the suspended load, and the speed coefficient K2 set according to the turning radius of the suspended load 7. A multiplier 48 is connected.

  The electromagnetic proportional pressure reducing valve signal setter 49 that outputs a signal for fully opening the electromagnetic proportional pressure reducing valve 30 in the pilot original pressure passage 15a is used under the condition that there is no suspension load and the reset switch 28 is ON (in the empty work mode). The command value of the electromagnetic proportional pressure reducing valve 30 is set to the maximum value. On the other hand, it is determined whether or not the suspension load calculated by the load calculator 42 has reached a specified value, and when the suspension load reaches the specified value, a determination device 50 is installed that outputs a crane mode value Dmc. Yes.

  Each output part of the electromagnetic proportional pressure reducing valve signal setting unit 49 and the determination unit 50 is connected to two input parts of the signal selector 51. The signal selector 51 outputs the crane mode value Dmc from the determiner 50 when the output of the AND calculator 47 is “0”, and is proportional to the electromagnetic proportionality when the output of the AND calculator 47 is “1”. The maximum value from the pressure reducing valve signal setter 49 is output.

  The output unit of the multiplier 48 and the output unit of the signal selector 51 are connected to a multiplier 52, and the output unit of the multiplier 52 and the output unit of the signal selector 51 are connected to 2 of the signal selector 53. Connected to two inputs. This signal selector 53 is a signal obtained by multiplying the crane mode value Dmc from the signal selector 51 by the multiplier 52 and the work speed coefficient K from the multiplier 48 when the output of the AND calculator 47 is “0”. Is output to the electromagnetic proportional pressure reducing valve 30 and the output to the electromagnetic proportional pressure reducing valve 30 is limited. When the output of the AND calculator 47 is “1”, the maximum value set by the electromagnetic proportional pressure reducing valve signal setting device 49 is set. The value is output to the electromagnetic proportional pressure reducing valve 30 as it is.

  The head pressure detector 8, the rod pressure detector 9, the boom angle detector 10, the arm angle detector 11, the member information storage device 41 and the load calculator 42 are loaded on the suspended load 7 suspended from the work device 2. That is, load detecting means 54 for detecting a suspended load is configured.

  The boom angle detector 10, the arm angle detector 11, the member information storage unit 41 and the turning radius calculator 43 constitute turning radius detection means 55 for detecting the turning radius of the suspended load 7 suspended from the work device 2. is doing.

  Each data table 45, 46, multiplier 48, determiner 50, signal selector 51, multiplier 52, and signal selector 53 is in accordance with the load of the suspended load 7 and according to the turning radius of the suspended load 7. The work speed limiting means 56 is configured to perform a calculation for limiting the work speed.

  The load judgment unit 44, the AND operation unit 47, the electromagnetic proportional pressure reducing valve signal setting unit 49, and the signal selection units 51 and 53 are only when the operator switches the reset switch 28 to the empty work mode under the condition that the suspended load 7 is not loaded. Restriction release means 57 for releasing the restriction of the work speed by the work speed restriction means 56 is configured.

  As shown in FIG. 4, one data table 45 determines the relationship between the load of the suspended load 7, that is, the suspended load, and the speed coefficient K1, and when the suspended load increases, the speed coefficient K1 has a certain range. It has the characteristic that it falls within.

  As shown in FIG. 5, the other data table 46 determines the relationship between the suspended load turning radius and the speed coefficient K2, and when the suspended load turn radius increases, the speed coefficient K2 is the same as the speed coefficient K1. It has a characteristic that it falls within a certain range.

  Next, the outline of the control process will be described with reference to the flowchart shown in FIG. In addition, the circled number in this flowchart shows the step number of a control procedure.

(Step 1)
Read the state of crane mode switch 27.

(Step 2)
It is determined whether the crane mode switch 27 is on.

(Step 3)
When the crane mode switch 27 is on in step 2, the engine speed is limited to a predetermined crane mode setting speed.

(Step 4)
The crane speed control process described later shown in FIG. 7 is performed. In this crane speed control process, the engine speed is maintained at a constant crane mode setting speed, and variable control is not performed.

(Step 5)
When the crane mode switch 27 is off in step 2, the engine speed is set to the normal work mode speed. That is, a general control method is employed in which the engine speed is variably controlled according to the load.

  Step 3 and step 5 may be omitted. That is, when the crane mode switch 27 is on in step 2, the crane speed control process in step 4 may be performed immediately without limiting the engine speed.

  Next, the contents of the crane speed control process in step 4 will be described with reference to the flowchart shown in FIG. In addition, the circled number in this flowchart shows the step number of a control procedure.

(Step 6)
The head pressure detector 8, the rod pressure detector 9, the boom angle detector 10, and the arm angle detector 11 of the boom cylinder 3 a of the work device 2 are used to adjust the head pressure, the rod pressure, the boom angle, and the arm angle of the boom cylinder 3 a. Read each signal.

(Step 7)
Since the member information (the length between the connecting pins of the boom 3, the arm 4 and the bucket 5, the mass, the center position of the mass, etc.) of the work device 2 is known, the detected head pressure, rod pressure, boom angle of the boom cylinder 3a The load of the suspended load 7, that is, the suspended load is obtained from each input signal of the arm angle. At this time, the suspension load is subjected to band-pass filter processing or the like, omitting the AC component and obtaining a smooth DC component. The calculation for obtaining the suspension load is performed in consideration of the balance of moments around the connecting pin 3P at the base end of the boom, and the force acting on the boom cylinder 3a is calculated from the head pressure and rod pressure of the boom cylinder 3a. 41, the moment of the self-weight acting on each member of the work device 2 and the boom from the member information of the work device 2 stored in 41 and the boom angle and arm angle detected by the boom angle detector 10 and the arm angle detector 11 Since the moments of the force acting on the cylinder 3a are known and these moments balance with the moments of the unknown suspension load, the unknown suspension load can be calculated.

(Step 8)
Since the member information of the working device 2 is known, the suspension is based on the turning center of the upper swing body 1b from the boom angle and arm angle detected by the boom angle detector 10 and the arm angle detector 11 of the working device 2. Find the turning radius of the load.

(Step 9)
It is determined whether the work mode is a hanging work mode.

(Step 10)
If it is not the suspension work mode at step 9, it is determined whether or not the lifting load has reached the specified value by the determiner 50, and it is determined whether or not the lifting of the lifting load 7 is completed. If the suspension load has not reached the specified value in step 10, the process returns to step 1.

(Step 11)
If the suspension load reaches the specified value in step 10, it is a case where the lifting of the suspension load 7 is completed, so the operation mode is set to the suspension operation mode.

(Step 12)
The signal selector 51 sets the command value of the electromagnetic proportional pressure reducing valve 30 to be lowered to the crane mode value Dmc that is the suspension work mode value.

(Step 13)
After the work mode is set to the suspension work mode in step 11, the process returns to step 9 and then proceeds to step 13, where the suspension load is almost zero and whether the operator has turned on the reset switch 28 or not. Determine.

(Step 14)
If the condition of step 13 is not satisfied, a speed coefficient K1 corresponding to the load of the suspended load 7, that is, the suspended load is set from the data table 45 shown in FIGS. The speed coefficient K1 is a characteristic that decreases within a certain range as the suspension load increases.

(Step 15)
A speed coefficient K2 corresponding to the turning radius is set from the data table 46 shown in FIGS. The speed coefficient K2 is a characteristic that decreases within a certain range as the turning radius increases so that the peripheral speed when the suspended load 7 turns is constant.

(Step 16)
The work speed limiting means 56 of the controller 26 uses the multiplier 48 to obtain the work speed coefficient K from the following formula based on the speed coefficient K1 set from the suspension load and the speed coefficient K2 set from the turning radius.

Work speed factor K = K1 × K2
(Step 17)
The multiplier 52 corrects the command value of the electromagnetic proportional pressure reducing valve 30 by the following equation based on the crane mode value Dmc from the determiner 50 and the signal selector 51 and the work speed coefficient K from the multiplier 48.

Command value of proportional solenoid valve 30 = (crane mode value Dmc) x (working speed factor K)
(Step 18)
When the condition of step 13 is satisfied, that is, when the operator turns on the reset switch 28 when the suspension load is almost zero, the work mode is set to the empty work mode.

(Step 19)
In this idle work mode, the restriction release means 57 functions to release the speed restriction of the suspension work mode, and the electromagnetic proportional pressure reducing valve 30 is controlled to the fully open state by the maximum command value, for example, in a state where no suspension load is applied. Speed up your empty work. In short, when there is no hanging load and the reset switch 28 is on, the speed limit is released and high speed operation is enabled.

  In this manner, the electromagnetic proportional pressure reducing valve 30 is driven by the obtained command value, and the pilot primary pressure supplied to the pilot operating device 23, that is, the pilot original pressure, is limited, whereby the pilot valves 24, 25, the pilot secondary pressure output to the spools 17 and 18 of the control valve 16 via the pilot passage 22 is limited, and the displacement amount of the spools 17 and 18 with respect to the same lever operation amount of the pilot actuator 23 is limited. The operating speed of the actuator 3a, 4a, 5a, 19, 20, 21 of the work machine is limited.

  Next, the effect of this embodiment will be described.

  When the working device 2 is used for crane work, after the engine speed is limited to the crane mode setting speed by the crane mode switch 27, the pilot pressures of the pilot valves 24 and 25 for piloting the control valve 16 are controlled by the controller 26. Is controlled by the electromagnetic proportional pressure reducing valve 30 to perform a crane speed control process that limits the work speed without switching the engine speed (steps 3 and 4), so that it corresponds to the load of the suspended load 7, that is, the suspended load. It is possible to prevent a sense of incongruity and an increase in noise due to changes in engine noise, and it is possible to continue stable work in a stable engine speed range.

  A common pilot source pressure supplied to the pilot valves 24 and 25 is controlled by the electromagnetic proportional pressure reducing valve 30 in the pilot source pressure passage 15a to output from the pilot valves 24 and 25 to the control valve 16. The pilot pressures of a plurality of systems can be controlled at the same time, and the number of parts can be reduced.

  As the suspension load detected by the load detection means 54 increases, the work speed is strongly restricted by increasing the pilot pressure reduction control by the data table 45 of the work speed restriction means 56 (step 14). Stable operation can be continued by suppressing run-out.

  As the turning radius of the suspended load 7 detected by the turning radius detection means 55 increases, the work speed is strongly restricted by strengthening the pilot pressure reduction control by the data table 46 of the work speed restriction means 56 (step 15). Stable work can be continued by suppressing the peripheral speed of the suspended load 7 during turning to be constant.

  As the suspension load detected by the load detection means 54 increases and as the turning radius of the suspension load 7 detected by the turning radius detection means 55 increases, the work speed limiting means 56 increases the pressure reduction control of the pilot pressure. By restricting the speed strongly (steps 14 and 15), the swing of the suspended load 7 can be suppressed, and the peripheral speed when the suspended load 7 is turned can be suppressed to be constant, so that stable work can be continued.

  At this time, the multiplier 48 of the work speed limiting means 56 sets the work speed coefficient K by multiplying the speed coefficient K1 corresponding to the suspended load by the speed coefficient K2 corresponding to the turning radius of the suspended load 7 (step 16). ) Since the pilot pressure is synergistically controlled to reduce both the increase in the suspension load and the increase in the turning radius, a more stable operation can be performed.

  When the suspension load is equal to or greater than the specified value, the load determination unit 44 determines that there is a load, and regards the work mode as the suspension work mode, and determines the actuator 3a, 4a, 5a, 19, 20, 21 from the suspension load and the turning radius. Since the operating speed is limited (steps 10 to 17), stable crane work can be performed.

  Only when there is no suspension load and the operator turns on the reset switch 28, the restriction release means 57 releases the restriction on the work speed (suspending work mode) (steps 13, 18, and 19). On the contrary, it is possible to prevent the restriction of the working speed (suspending work mode) from being released.

  Next, based on FIG. 8 and FIG. 9, a second embodiment which is a modification of the controller 26 of the first embodiment will be described. 1 to 7 used in the first embodiment are referred to as appropriate, and the same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted.

  An AND operation unit 47 that performs a logical product operation of the output of the reset switch 28 and the output of the load determination unit 44 is connected to the output unit of the reset switch 28 and the load determination unit 44, and the output unit of each data table 45, 46. The work speed coefficient set by selecting the minimum value of the speed coefficient K1 set according to the load of the suspended load 7, that is, the suspended load, and the speed coefficient K2 set according to the turning radius of the suspended load 7. A minimum value selector 60 for outputting K is connected.

  The output unit of the minimum value selector 60 and the output unit of the signal selector 51 are connected to the multiplier 52. The output unit of the multiplier 52 and the output unit of the signal selector 51 are connected to the signal selector 53. Connected to two inputs. When the output of the AND calculator 47 is “0”, the signal selector 53 multiplies the crane mode value Dmc from the signal selector 51 by the multiplier 52 and the work speed coefficient K from the minimum value selector 60. Is output to the electromagnetic proportional pressure reducing valve 30 to limit the output to the electromagnetic proportional pressure reducing valve 30. When the output of the AND computing unit 47 is “1”, it is set by the electromagnetic proportional pressure reducing valve signal setting device 49. The maximum value is output to the electromagnetic proportional pressure reducing valve 30 as it is.

  Each data table 45, 46, minimum value selector 60, decision unit 50, signal selector 51, multiplier 52, and signal selector 53 depend on the load of the suspended load 7 and also on the turning radius of the suspended load 7. Thus, the work speed limiting means 56 for performing a calculation for limiting the work speed is configured.

  Next, the crane speed control process of the present embodiment will be described with reference to the flowchart shown in FIG. Since this flowchart is common to most of the flowchart shown in FIG. 7 of the first embodiment, only different parts will be described.

  The speed coefficient K1 corresponding to the load of the suspended load 7, that is, the suspension load is set from the data table 45 (step 14), and the speed coefficient K2 corresponding to the turning radius is set from the data table 46 (step 15) is shown in FIG. 8, the minimum value selector 60 of the working speed limiting means 56 shown in FIG. 8 is used to set the load coefficient of the suspended load 7, that is, the speed coefficient K1 corresponding to the suspended load and the turning radius of the suspended load 7. The point (step 16) which calculates | requires the working speed coefficient K = MIN (K1, K2) by selecting the minimum value with the corresponding speed coefficient K2 differs from the thing of FIG. The point (step 17) in which the command value of the electromagnetic proportional pressure reducing valve 30 is corrected from the obtained work speed coefficient K and the crane mode value Dmc by the following equation is the same as that in FIG.

Command value of proportional solenoid valve 30 = (crane mode value Dmc) x (working speed factor K)
In this way, the controller 26 causes the minimum value selector 60 of the work speed limiting means 56 to use the speed coefficient K1 corresponding to the load of the suspended load 7, that is, the suspended load, and the speed coefficient K2 corresponding to the turning radius of the suspended load 7. The electromagnetic proportional pressure reducing valve 30 shown in FIG. 1 is driven in accordance with the work speed coefficient K set by selecting the minimum value and the pilot pressure is controlled to be reduced.

  That is, as shown in FIG. 1, in this embodiment as well, in the same way as in the first embodiment, the pilot primary pressure, that is, the pilot original pressure supplied to the pilot operating device 23 is limited, thereby controlling the pilot operation. The pilot secondary pressure output from the pilot valves 24 and 25 of the controller 23 to the spools 17 and 18 of the control valve 16 via the pilot passage 22 is limited, and the spool 17 and 18 The operating speed of the actuators 3a, 4a, 5a, 19, 20, 21 of the work machine is limited by limiting the amount of displacement.

  According to the embodiment shown in FIGS. 8 and 9, the minimum value selector 60 of the work speed limiting means 56 sets the speed coefficient K1 corresponding to the load of the suspended load 7 and the turning radius of the suspended load 7. The minimum value of the corresponding speed coefficient K2 is selected and the work speed coefficient K is set, and the pilot pressure is reduced in relation to the larger one of the increase in the load of the suspended load 7 or the enlargement of the turning radius of the suspended load 7 Since it controls, stable work can be ensured.

  Next, a third embodiment of the crane work control device according to the present invention will be described based on FIGS. As shown in FIG. 2, the description of the work machine provided with the work device 2 in the machine body 1 has already been given and is omitted.

  As shown in FIG. 10, variable displacement pumps 13 and 14 and a pilot pressure pump 15 are connected to the drive shaft of the engine 12. The variable displacement pumps 13 and 14 are main pumps that variably control the pump displacement by variably controlling the tilt angle of the swash plate by regulators 13r and 14r serving as displacement variable means that has received the control pressure. These variable displacement pumps 13 and 14 are connected to a control valve 16 that controls the direction and flow rate of the working oil as the working fluid pressurized and supplied from the variable displacement pumps 13 and 14.

  Inside the control valve 16, spools 17 and 18 that are stroke-controlled by pilot pressure supplied to one end surface and the other end surface are provided corresponding to each actuator (in FIG. 10, spools corresponding to the arm cylinder 4a). Only the details are shown), and the operation of each actuator of the hydraulic excavator is controlled by the hydraulic oil whose direction and flow rate are controlled by the spools 17 and 18. In other words, the boom cylinder 3a, the arm cylinder 4a, and the bucket cylinder 5a are controlled to extend and retract, and the traveling motors 19 and 20 as actuators for driving the left and right crawlers of the lower traveling body 1a and the upper swinging body 1b are swung. Each forward / reverse operation of the turning motor 21 as an actuator to be driven is controlled.

  The spools 17 and 18 in the control valve 16 are displaced by receiving pilot pressure supplied from the pilot passage 22 at one end and the other end, respectively. These pilot passages 22 are pilots operated by an operator of the work machine. The output unit of the controller 23 is communicated.

  The pilot operating device 23 includes a plurality of pilot valves (remote control valves) 24 and 25 that can be operated by a single operating lever. These pilot valves 24 and 25 are supplied with pilot original pressure, that is, pilot 1 from the pilot pressure pump 15. When the secondary pressure is supplied, the pilot secondary pressure generated according to the operation amount by lever operation is output to one end or the other end of each spool 17, 18 of the control valve 16 through the pilot passage 22. , 18 is displaced.

  On the input side of the controller 26 mounted on the work machine, a head pressure detector 8 that detects the head pressure of the boom cylinder 3a, a rod pressure detector 9 that detects the rod pressure, and a boom angle detector 10 that detects the boom angle. The arm angle detector 11 for detecting the arm angle is connected, the crane mode switch 27 for switching the normal work mode such as excavation to the crane work mode, the suspension work mode and the empty work operated by the operator in the crane work mode. A reset switch 28 is connected as a switching operation device for switching between modes.

  The system configuration and control flow of the controller 26 shown in FIG. 10 are the system configuration and control flow of the controller 26 shown in FIGS. 3 to 7, or the system configuration of the controller 26 shown in FIGS. And since it is the same as that of a control flow, those description is abbreviate | omitted.

  The output side of the controller 26 includes an engine speed control unit that controls the speed of the engine 12, a monitor 29 that outputs a crane work content and an alarm, and an electromagnetic valve as an electromagnetic valve that supplies a control pressure for pump capacity control. A proportional pressure reducing valve 61 is connected. The electromagnetic proportional pressure reducing valve 61 includes a branch passage 15b piped between a pilot original pressure passage 15a for supplying a pilot original pressure, that is, a pilot primary pressure, to the pilot valves 24, 25 from the pilot pressure pump 15 and the tank Т. It is provided inside.

  In the control valve 16, center bypass passages 33 and 34 branched from hydraulic oil supply passages 31 and 32 communicated with an external pump discharge passage communicate with each other through a plurality of spools 17 and 18 in a neutral position. The orifices 35 and 36 for generating a negative control pressure for pump flow rate control (hereinafter simply referred to as “negative control pressure”) and a relief valve (hereinafter referred to as “the negative control pressure”) are formed at the rear ends of these center bypass passages 33 and 34. "Negative control relief valves 37, 38") are provided respectively, and communicated with the tank T through these orifices 35, 36 and negative control relief valves 37, 38.

  Negative control pressure passages (hereinafter simply referred to as “negative control pressure passages”) 39 and 40 for taking out the negative control pressure from the positions immediately before the orifices 35 and 36 and the negative control relief valves 37 and 38 are branched to these negative control pressure passages. 39 and 40 are connected to the regulators 13r and 14r of the variable displacement pumps 13 and 14 via the shuttle valves 62 and 63, and give a negative control pressure for variably controlling the swash plate tilt angle to the regulators 13r and 14r.

  In the negative control, as the spools 17 and 18 are closer to the neutral position in order to stop the actuators 3a, 4a, 5a, 19, 20, and 21, a larger negative control pressure is generated in the negative control pressure passages 39 and 40. As the pressure increases, the regulators 13r and 14r control the swash plate tilt angle to be smaller and control the pump discharge flow rate to be smaller.

  The negative control pressure passages 39 and 40 are connected to one inlet of each shuttle valve 62 and 63, and the output port of the electromagnetic proportional pressure reducing valve 61 is connected to the other inlet of each shuttle valve 62 and 63. . Therefore, even when no negative control pressure is generated in the negative control pressure passages 39 and 40 when the actuator is operated, the pseudo remote control pressure is supplied from the electromagnetic proportional pressure reducing valve 61 to the regulators 13r and 14r via the shuttle valves 62 and 63, thereby It becomes possible to suppress the discharge flow rate.

  In this way, in the hydraulic circuit that controls the hydraulic fluid supplied from the variable displacement pumps 13 and 14 driven by the engine 12 to the actuators 3a, 4a, 5a, 19, 20, and 21 by the control valve 16, the variable displacement Pump discharge flow rate control means 64 for controlling the pump discharge flow rate supplied from the mold pumps 13 and 14 to the control valve 16 is provided.

  That is, the pump discharge flow rate control means 64 is connected to regulators 13r and 14r as capacity variable means for variably controlling the capacity of the variable displacement pumps 13 and 14, and the center bypass passages 33 and 34 of the control valve 16, and the negative control pressure Negative control pressure passages 39 and 40 that respectively lead the pressure to the regulators 13r and 14r, shuttle valves 62 and 63 respectively provided in the negative control pressure passages 39 and 40, and the shuttle valves 62 and 63 to the regulators 13r and 14r. On the other hand, an electromagnetic proportional pressure reducing valve 61 that supplies a negative control pressure and alternatively a control pressure for controlling the pump displacement is provided.

  The controller 26 controls the electromagnetic proportional pressure reducing valve 61 of the pump discharge flow rate control means 64 instead of lowering the pilot pressure in order to limit the actuator operating speed when the working device 2 is used for crane work. Thus, the purpose is achieved by controlling the pump discharge flow rate to be reduced by the pseudo negative control pressure and limiting the pump discharge flow rate.

  That is, the shuttle valve 62, 63 is used to select a high pressure between the pressure output from the electromagnetic proportional pressure reducing valve 61 and the negative control pressure generated by the control valve 16, and when the actuator is operated to reduce the negative control pressure generated by the control valve 16, The pump flow rate is limited by the pseudo negative control pressure supplied from the electromagnetic proportional pressure reducing valve 61 to the regulators 13r and 14r via the shuttle valves 62 and 63.

  According to the embodiment shown in FIG. 10, when the working device is used for crane work, the controller 26 determines the pump discharge flow rate supplied from the variable displacement pumps 13 and 14 to the control valve 16. Since the operating speed of the actuators 3a, 4a, 5a, 19, 20, 21 is limited without changing the engine speed by performing the reduction control by the control means 64, the change of the engine noise corresponding to the load of the suspended load 7 It is possible to prevent a sense of incongruity and an increase in noise, and it is possible to continue stable work in a stable engine speed range.

  Further, the pump discharge flow rate control means 64 is provided with shuttle valves 62 and 63 in the negative control pressure passages 39 and 40 drawn from the center bypass passages 33 and 34 of the control valve 16, and through the shuttle valves 62 and 63, Since the control pressure for pump displacement control is supplied from the electromagnetic proportional pressure reducing valve 61 to the regulators 13r and 14r of the variable displacement pumps 13 and 14, the pump discharge flow rate control means 64 can be utilized by utilizing the existing negative control system effectively. Can be configured easily.

  The crane work control apparatus of the present invention is a control apparatus suitable for the hydraulic excavator A shown in FIG. 2, but can also be used for other work machines having similar work arms.

It is a circuit diagram showing a 1st embodiment of a crane work control device concerning the present invention. It is a side view which shows the structure of the working machine carrying a control apparatus same as the above. It is a block diagram which shows the system configuration | structure of the controller in a control apparatus same as the above. It is a characteristic figure of the data table which shows the relationship between the suspension load and speed coefficient K1 in a control apparatus same as the above. It is a characteristic figure of the data table which shows the relationship between the turning radius of the hanging load in the control apparatus same as the above, and the speed coefficient K2. It is a flowchart which shows the outline | summary of the control processing by a control apparatus same as the above. It is a flowchart which shows the crane speed control processing routine in a control apparatus same as the above. It is a block diagram which shows 2nd Embodiment showing the modification in the controller of the crane work control apparatus which concerns on this invention. It is a flowchart which shows a part of crane speed control processing routine by the controller shown by 2nd Embodiment same as the above. It is a circuit diagram which shows 3rd Embodiment of the crane work control apparatus which concerns on this invention.

Explanation of symbols

1 Airframe 2 Working device
3a, 4a, 5a, 19, 20, 21 Actuator 7 Suspended load
12 engine
13, 14 Variable displacement pump as main pump
Regulator as 13r, 14r capacity variable means
15a Pilot pressure passage
16 Control valve
24, 25 Pilot valve
26 Controller
28 Reset switch as selector
30 Solenoid proportional pressure reducing valve
33, 34 Center bypass passage
39, 40 Negative control pressure passage
44 Load detector
48 Multiplier
54 Load detection means
55 Turning radius detection means
56 Working speed limit means
57 Restriction release means
60 Minimum value selector
61 Solenoid proportional pressure reducing valve
62, 63 Shuttle valve
64 Pump discharge flow rate control means
K1, K2 Speed factor K Work speed factor

Claims (11)

A control valve for controlling a working fluid supplied to an actuator from a main pump driven by an engine of a working machine having a working device in the airframe;
A pilot valve that pilot-operates the control valve with a pilot pressure generated by being operated by an operator of the work machine;
A pressure reducing valve capable of reducing the pilot pressure;
A crane work control device comprising: a controller that controls the pressure reduction of the pilot pressure by a pressure reducing valve when the work device is used for crane work. The crane work control device according to claim 1, wherein the pressure reducing valve is provided in a pilot original pressure passage that supplies a common pilot original pressure to the plurality of pilot valves. A control valve for controlling a working fluid supplied to an actuator from a variable displacement pump driven by an engine of a work machine having a work device in the airframe;
Pump discharge flow rate control means for controlling the pump discharge flow rate supplied from the variable displacement pump to the control valve;
A crane work control device comprising: a controller that controls the pump discharge flow rate to be reduced by pump discharge flow rate control means when the work device is used for crane work. The pump discharge flow rate control means is
Capacity variable means for variably controlling the capacity of the variable capacity pump;
A negative control pressure passage that is drawn from the center bypass passage of the control valve and guides the negative control pressure to the capacity variable means;
A shuttle valve provided in the negative control pressure passage;
4. The crane work control apparatus according to claim 3, further comprising: a solenoid valve that supplies a control pressure for controlling pump displacement, alternatively to a negative control pressure, to the displacement variable means by means of a shuttle valve. The controller
Load detecting means for detecting the load of the suspended load suspended from the work device;
The crane work control device according to any one of claims 1 to 4, further comprising work speed limiting means for performing a calculation for limiting the work speed in accordance with a load of a suspended load. The controller
A turning radius detecting means for detecting a turning radius of the suspended load;
The crane work control device according to any one of claims 1 to 4, further comprising work speed limiting means for performing a calculation for limiting the work speed in accordance with a turning radius of the suspended load. The controller
Load detecting means for detecting the load of the suspended load suspended from the work device;
A turning radius detecting means for detecting a turning radius of the suspended load;
The crane work control device according to any one of claims 1 to 4, further comprising work speed limiting means for performing a calculation for limiting the work speed in accordance with both the load of the suspended load and the turning radius. A switching operation device that is operated by an operator to switch between a hanging work mode and an empty work mode,
The controller
A load determination device for determining the presence or absence of the load of the suspended load detected by the load detection means;
6. Restriction release means for releasing the restriction of the work speed by the work speed restriction means only when the operator switches the switching operation device to the idle work mode under the condition that there is no load of the suspended load. 7. The crane work control device according to 7. The crane work control device according to claim 8, wherein the load determiner determines that there is a load when the load of the suspended load is equal to or greater than a certain value. The controller speed limit means is
A multiplier that sets the work speed coefficient by multiplying the speed coefficient according to the load of the suspended load and the speed coefficient according to the turning radius of the suspended load,
The crane work control device according to any one of claims 7 to 9, wherein the pilot pressure is controlled to be reduced according to the work speed coefficient set by the multiplier. The controller speed limit means is
A minimum value selector that sets the work speed coefficient by selecting the minimum value of the speed coefficient according to the load of the suspended load and the speed coefficient according to the turning radius of the suspended load,
The crane work control device according to any one of claims 7 to 9, wherein the pilot pressure is reduced according to a work speed coefficient set by the minimum value selector.

Images