JP2013219864A - Working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working machine capable of preventing an electric motor from being operated in an overload state to prevent malfunction of the electric motor.SOLUTION: A working machine calculates a required output of an electric motor 82 on the basis of a discharge amount of a hydraulic oil of a hydraulic pump 81 calculated from an operation amount corresponding to a driving speed of operating levers 84a-84d, and required torque of the electric motor 82 calculated based on a posture of a boom 50, weight of a suspended load and an operation direction of the operating levers 84a-84d, and when the required output of the electric motor 82 is equal to or lower than a predetermined output, sets the number of revolution of the electric motor 82 corresponding to the required output of the electric motor 82, and when the required output of the electric motor 82 is larger than a predetermined output, sets the number of revolution of the electric motor 82 corresponding to the predetermined output or lower.

Description

  The present invention relates to a work machine including an electrically driven drive unit such as an electrically driven vehicle-mounted crane device.

  Conventionally, as this type of work machine, the current value input to the electric motor, the number of rotations of the electric motor, and the like so that the electric motor that drives the driving unit does not exceed a predetermined output, Is known to control the current input to the electric motor based on the above (see, for example, Patent Document 1).

JP 2003-70279 A

  In the work machine, the electric motor is controlled based on the current value input to the actually driven electric motor and the rotational speed of the actually driven electric motor. For this reason, when the load acting on the drive unit fluctuates rapidly, the output of the electric motor may exceed a predetermined output. In this case, in the work machine, the electric motor is driven in an overloaded state, and the electric motor may be damaged.

  An object of the present invention is to provide a work machine capable of preventing an electric motor from being operated in an overloaded state and preventing a failure of the electric motor.

  In order to achieve the above object, the present invention is a work machine that drives a drive unit by the power of an electric motor, the operation input means for inputting an operation for driving the drive unit, and the drive for detecting the state of the drive unit A state detection unit, a load detection unit for detecting a load acting on the drive unit based on the drive direction of the drive unit input to the operation input unit and the state of the drive unit detected by the drive unit state detection unit, and an operation The required electric motor output is calculated based on the drive speed of the drive unit input to the input means and the load acting on the drive unit detected by the load detection means, and the output of the required electric motor is less than a predetermined output In this case, the number of rotations of the electric motor that is the output of the required electric motor whose output is calculated is set, and when the output of the required electric motor is larger than the predetermined output, the electric power becomes the predetermined output or less. And it includes a rotational speed setting means for setting a revolution speed of over motor, an electric motor drive means for a rotary speed set by the rotational speed setting means drives the electric motor.

  As a result, when the calculated output of the required electric motor is equal to or higher than the predetermined output, the number of rotations of the electric motor at which the output is equal to or lower than the predetermined output is set, so that the electric motor is driven in an overloaded state. Is prevented.

  According to the present invention, it is possible to prevent the electric motor from being driven in an overload state, and thus it is possible to prevent the electric motor from being broken and to extend its life.

  Further, according to the present invention, since the electric motor is not driven in an overloaded state, it is possible to prevent overdischarge of the battery that supplies power to the electric motor, and it is possible to prevent deterioration of the battery.

It is a perspective view of the vehicle carrying the crane apparatus which shows one Embodiment of this invention. It is a front view of a crane apparatus. It is a schematic block diagram of a hydraulic pressure supply apparatus. It is a block diagram which shows the control system regarding operation of an operation part. It is a flowchart which shows a rotation speed control process. It is a flowchart which shows a rotation speed control process. It is a block diagram which shows the control system regarding operation of the remote control apparatus of other embodiment of this invention.

  1 to 6 show an embodiment of the present invention.

  A crane apparatus 10 as a working machine of the present invention is mounted on a vehicle 1 as shown in FIG.

  As shown in FIG. 1, the vehicle 1 includes a cab 3 provided on the front side of the chassis frame 2 and a cargo bed 4 provided on the rear side of the chassis frame 2. A crane device 10 is mounted on the chassis frame 2 therebetween.

  As shown in FIG. 2, the crane device 10 is pivoted on the base 20 fixed on the chassis frame 2 (FIG. 1), the outriggers 30 provided on both the left and right sides of the base 20, and the upper surface of the base 20. A swivel base 40 that is freely provided, a boom 50 that can be raised and lowered with respect to the swivel base 40, a wire rope 60 that hangs down from the distal end side of the boom 50, and a wire rope 60 that is wound or fed out. The winch 70 is provided.

  Each outrigger 30 can move outward in the width direction with respect to the base 20, and can extend downward by a hydraulic jack cylinder 31 (FIG. 3). The outrigger 30 stably supports the vehicle 1 with respect to the ground by grounding the lower end.

  The swivel base 40 is provided so as to be swivelable with respect to the base 20 by a ball bearing type or roller bearing type swivel circle (not shown), and is swung by a hydraulic swivel motor 41 (FIG. 3). A swivel post 42 extending in the up-down direction is provided on the upper surface of the swivel base 40, and a boom 50 is connected to the upper end side of the swivel post 42 so as to be raised and lowered.

  As shown in FIG. 2, the boom 50 includes a plurality of boom members 51 to 54, and boom members 52 to 54 that are adjacent to the distal end side inside the boom members 51 to 53 excluding the boom member 54 on the most distal side. It is configured in a multistage type that can be stored. The base end portion of the most proximal end boom member 51 is connected to the upper end side of the turning post 42 so as to be freely rotatable in the vertical direction. A hydraulic hoisting cylinder 55 is connected between the base end side of the boom member 51 and the swivel base 40, and the boom 50 is raised and lowered by the expansion and contraction operation of the hoisting cylinder 55. Also, a hydraulic telescopic cylinder 56 (FIG. 3) is provided in the boom member 51 on the most proximal end side, and the boom 50 is expanded and contracted by the expansion and contraction of the expansion cylinder 56.

  As shown in FIG. 2, a hook block 61 is connected to the distal end side of the wire rope 60, and the hook block 61 is suspended from the distal end portion of the boom 50. A suspended load can be latched to the hook block 61, and the suspended load latched to the hook block 61 is suspended from the tip of the boom 50.

  As shown in FIG. 2, the winch 70 converts a drum 71 around which the wire rope 60 is wound, a hydraulic winch motor 72 for rotating the drum 71 forward and backward, and the rotational speed and torque of the winch motor 72. And a speed reducer 73 that transmits to the drum 71.

  Actuators such as the jack cylinders 31, 31, the turning motor 41, the hoisting cylinder 55, the telescopic cylinder 56, and the winch motor 72 are operated by supplying and discharging hydraulic oil. The hydraulic oil that operates each actuator is supplied by a hydraulic pressure supply device 80 as shown in FIG.

  As shown in FIG. 3, the hydraulic supply device 80 supplies electric power to a hydraulic pump 81 for discharging hydraulic oil, an AC power drive electric motor 82 for driving the hydraulic pump 81, and the electric motor 82. And a control valve unit 84 for controlling the flow of hydraulic oil discharged from the hydraulic pump 81, and these are connected to the hydraulic oil circuit 85.

  The control valve unit 84 has a plurality of control valves corresponding to the respective actuators, and each control valve is operated by an operation lever 84a, 84b, 84c, 84d (hereinafter referred to as 84a to 84d) shown in FIG. Operated. In each control valve, the flow path of the hydraulic oil is switched according to the operation direction of the operation levers 84a to 84d, and the flow rate of the hydraulic oil can be adjusted according to the operation amount of the operation levers 84a to 84d. Further, each control valve constituting the control valve unit 84 has a switching means composed of a solenoid and can be operated by a signal from a controller which will be described later.

  In the hydraulic oil circuit 85, the discharge side of the hydraulic pump 81 is connected to the pump side port of the control valve unit 84, and the suction side of the hydraulic pump 81 is connected to the hydraulic oil tank 85a. Each actuator is connected to a port on the actuator side of the control valve unit 84. Furthermore, the hydraulic oil discharge port of the control valve unit 84 is connected to the hydraulic oil tank 85a.

  In addition, the crane device 10 includes a controller 90 for performing control related to the operation of the hydraulic pressure supply device 80.

  The controller 90 has a CPU, ROM, and RAM. When the controller 90 receives an input signal from a device connected to the input side, the CPU reads a program stored in the ROM based on the input signal, and stores a state detected by the input signal in the RAM. The output signal is transmitted to a device connected to the output side.

  On the input side of the controller 90, as shown in FIG. 4, a boom length detector 91 for detecting the expansion / contraction length of the boom 50, a boom angle detector 92 for detecting the undulation angle of the boom 50, A cylinder pressure detector 93 for detecting the pressure in the hoisting cylinder 55 and an operation state detector 94 for detecting the operation direction and operation amount (accelerator operation amount) of the operation levers 84a to 84d are connected. Yes. The operation state detector 94 detects the operation (for example, the operation position of the spool) of each control valve of the control valve unit 84 operated by the operation levers 84a to 84d, and operates from the detected operation of each control valve. The operation direction and the operation amount of the levers 84a to 84d are detected.

  An inverter 95 for controlling the number of revolutions of the electric motor 82 is connected to the output side of the controller 90.

  Further, as shown in FIG. 4, the controller 90 includes an attitude / load calculation unit 90a, an operation direction detection unit 90b, a required torque calculation unit 90c, a required flow rate calculation unit 90d, an electric motor output calculation unit 90e, An electric motor rotation number calculation unit 90f and an electric motor rotation number output unit 90g are provided.

  The posture / load calculation unit 90a calculates the posture of the boom 50 and the load of the suspended load based on the detection result of the boom length detector 91, the detection result of the boom angle detector 92, and the detection result of the cylinder pressure detector 93. .

  The operation direction detection unit 90b detects the operation direction of the operation levers 84a to 84d from the detection result of the operation state detector 94.

  The necessary torque calculator 90c calculates the necessary torque of the electric motor 82 based on the calculation result of the posture / load calculator 90a and the detection result of the operation direction detector 90b.

  The required flow rate calculation unit 90d acquires the operation amount of the operation levers 84a to 84d from the detection result of the operation state detector 94, and calculates the required flow rate of the hydraulic oil based on the operation amount of the operation levers 84a to 84d.

  The electric motor output calculation unit 90e calculates a necessary output of the electric motor 82 based on the calculation result of the necessary torque calculation unit 90c and the calculation result of the necessary flow rate calculation unit 90d, and the calculated output of the electric motor 82 is equal to or less than a predetermined output. In this case, the calculated output is set as the output of the electric motor 82, and when the calculated output of the electric motor 82 is larger than the predetermined output, the predetermined output is set as the output of the electric motor 82.

  The electric motor rotation number calculation unit 90f calculates the rotation number of the electric motor 82 from the output of the electric motor 82 calculated by the electric motor output calculation unit 90e.

  The electric motor rotation speed output unit 90g outputs the calculation result of the electric motor rotation speed calculation unit 90f to the inverter 95.

  In the crane apparatus as the work machine configured as described above, the rotation speed of the electric motor 82 during crane work is controlled by the inverter 95 so as to be the rotation speed calculated by the electric motor rotation speed calculation unit 90f. The

  The controller 90 detects that the operation performed by the user during the crane work is an operation for driving the electric motor 82 in an overload state, and the rotation of the electric motor 82 in which the electric motor 82 is not in an overload state. A rotation speed setting process for setting the number is performed. The operation of the controller at this time will be described with reference to the flowchart of FIG.

(Step S1)
In step S1, the CPU determines whether or not the operation levers 84a to 84d have been operated. If it is determined that the operation levers 84a to 84d are operated, the process proceeds to step S2, and if it is not determined that the operation levers 84a to 84d are operated, the rotation speed setting process is terminated.

(Step S2)
When it is determined in step S1 that the operation levers 84a to 84d are operated, in step S2, the CPU calculates a necessary output of the electric motor 82, and moves the process to step S3.
Here, based on the detection result of the boom length detector 91, the detection result of the boom angle detector 92, the detection result of the cylinder pressure detector 93, and the operation state of the operation levers 84a to 84d, The required electric motor output is calculated from the operation direction detector 90b, the required torque calculator 90c, the required flow rate calculator 90d, and the electric motor output calculator 90e.

(Step S3)
In step S3, the CPU determines whether or not the required output of the electric motor 82 calculated in step S2 is equal to or less than a predetermined output. If it is determined that the output of the electric motor 82 is equal to or less than the predetermined output, the process proceeds to step S4. If the output of the electric motor 82 is not determined to be equal to or less than the predetermined output, the process proceeds to step S5.

(Step S4)
When it is determined in step S3 that the required output of the electric motor 82 is equal to or less than the predetermined output, in step S4, the CPU sets the rotation speed of the electric motor 82 based on the calculated output of the required electric motor 82, The rotation speed setting process ends.

(Step S5)
If it is determined in step S3 that the required output of the electric motor 82 is less than or equal to the predetermined output, the CPU sets the rotation speed of the electric motor 82 based on the predetermined output in step S5, and performs the rotation speed setting process. finish.

  Further, the controller 90 is operated to be driven in the end direction by the operation levers 84a to 84d in a state where each actuator is positioned at the end of the movable range, for example, the state where the hoisting cylinder 55 is extended to the maximum. In this case, stroke end rotation speed setting processing is performed to set the rotation speed of the electric motor 82 to a predetermined rotation speed regardless of the operation amount of the operation levers 84a to 84d. The operation of the controller 90 at this time will be described using the flowchart of FIG.

(Step S11)
In step S11, the CPU determines whether or not the actuator drive position is located at the end of the movable range. If it is determined that the drive position of the actuator is located at the end of the movable range, the process proceeds to step S12, and if it is not determined that the drive position of the actuator is located at the end of the movable range. The stroke end rotation speed setting process is terminated.

(Step S12)
If it is determined in step S11 that the drive position of the actuator is located at the end of the movable range, the CPU determines in step S12 whether or not an operation for driving the actuator in the direction of the end of the movable range has been performed. . If it is determined that the operation of driving the actuator in the direction of the end of the movable range has been performed, the process proceeds to step S13, and if it is not determined that the operation of driving the actuator in the direction of the end of the movable range has been performed, the stroke End rotation speed setting processing ends.

(Step S13)
If it is determined in step S12 that the operation for driving the actuator in the direction of the end of the movable range has been performed, in step S13, the CPU sets the rotation speed of the electric motor 82 to a predetermined rotation speed, and performs a stroke end rotation speed setting process. finish.

  Thus, according to the crane apparatus as the working machine of the present embodiment, the hydraulic oil discharge amount of the hydraulic pump 81 calculated from the operation amount corresponding to the drive speed of the operation levers 84a to 84d and the attitude of the boom 50. The required output of the electric motor 82 is calculated based on the load of the suspended load and the required torque of the electric motor 82 calculated based on the operation direction of the operation levers 84a to 84d. When the number of rotations of the electric motor 82 that is the output of the electric motor 82 that requires output is set when the output is less than the predetermined output, and the output of the required electric motor 82 is greater than the predetermined output, the output becomes the predetermined output or less. The rotational speed of the electric motor 82 is set. As a result, it is possible to prevent the electric motor 82 from being driven in an overloaded state, and thus it is possible to prevent the electric motor 82 from being broken and to extend its life. In addition, since the electric motor 82 is not driven in an overloaded state, it is possible to reduce power consumption. Furthermore, since the electric motor 82 is driven at a preset rotation speed, the rotation speed of the electric motor 82 does not change during crane work. For this reason, it is possible to prevent an abrupt change in the operation speed during crane work and improve safety. In addition, since the electric motor 82 is not driven in an overload state, the battery 83 can be prevented from being overdischarged, and the battery 83 can be prevented from deteriorating.

  Further, when the operation levers 84a to 84d are operated in the direction toward the end of the movable range when the driving position of the actuator is located at the end of the movable range, regardless of the operation amount of the operation levers 84a to 84d, The rotation speed of the electric motor 82 is set to a predetermined rotation speed. As a result, unnecessary driving of the electric motor 82 can be restricted at a position where the actuator is not driven, so that power consumption can be reduced.

  FIG. 7 shows another embodiment of the present invention. In addition, the same code | symbol is attached | subjected and shown to the component similar to the said embodiment.

  The crane device 10 includes a remote operation device 100 for remotely operating the hydraulic pressure supply device 80.

  The controller 90 of the crane device 10 is provided with a wireless communication unit (not shown), and an operation signal is input from the remote operation device 100.

  The controller 90 includes an attitude / load calculation unit 90a1, an operation state detection unit 90b1, a required torque calculation unit 90c1, a required flow rate calculation unit 90d1, an electric motor output calculation unit 90e1, an electric motor rotation number calculation unit 90f1, An electric motor rotation speed output unit 90g1 and a valve switching output unit 90h1 are provided.

  The posture / load calculation unit 90a1 calculates the posture of the boom 50 and the load of the suspended load based on the detection result of the boom length detector 91, the detection result of the boom angle detector 92, and the detection result of the cylinder pressure detector 93. .

  The operation state detection unit 90b1 detects the drive direction and drive speed of each actuator input based on the operation signal input from the remote operation device 100.

  The necessary torque calculator 90c1 calculates the required torque of the electric motor 82 based on the calculation result of the posture / load calculator 90a1 and the driving direction detected by the operation state detector 90b1.

  The required flow rate calculation unit 90d1 calculates the required flow rate of hydraulic oil based on the driving speed detected by the operation state detection unit 90b1.

  The electric motor output calculation unit 90e1 calculates the required output of the electric motor 82 based on the calculation result of the necessary torque calculation unit 90c1 and the calculation result of the necessary flow rate calculation unit 90d1, and the calculated output of the electric motor 82 is equal to or less than a predetermined output. In this case, the calculated output is set as the output of the electric motor 82, and when the calculated output of the electric motor 82 is larger than the predetermined output, the predetermined output is set as the output of the electric motor 82.

  The electric motor rotation number calculation unit 90f1 calculates the rotation number of the electric motor 82 from the output of the electric motor 82 calculated by the electric motor output calculation unit 90e1.

  Electric motor rotation speed output unit 90g1 outputs the calculation result of electric motor rotation speed calculation unit 90f1 to inverter 95.

  The valve switching output unit 90h1 outputs a valve switching signal corresponding to the driving direction and driving speed of each actuator detected by the operation state detection unit 90b1 to the control valve unit 84.

  In the crane apparatus as the work machine configured as described above, the electric motor 82 at the time of crane work is an inverter so that the rotation number calculated by the electric motor rotation number calculation unit 90f1 is the same as in the above embodiment. The rotational speed is controlled by 95.

  As described above, according to the crane device as the work machine of the present embodiment, it is possible to prevent the electric motor 82 from being driven in an overloaded state, as in the above-described embodiment. It is possible to prevent this and extend the life. In addition, since the electric motor 82 is not driven in an overloaded state, it is possible to reduce power consumption. Furthermore, since the electric motor 82 is driven at a preset rotation speed, the rotation speed of the electric motor 82 does not change during crane work. For this reason, it is possible to prevent an abrupt change in the operation speed during crane work and improve safety.

  In the above embodiment, a vehicle-mounted crane device is shown as an example of a work machine. However, for example, it may be an electrically driven work machine such as a mobile crane, an aerial work vehicle, a fixed crane, or a vehicle transporter. The present invention can be applied.

  In the above embodiment, a hydraulic drive system using an electric motor as a drive source has been described. However, the present invention can also be applied to a work machine including an electric actuator that directly drives a drive unit by the electric motor.

  In the above embodiment, the controller 90 sets the rotation speed of the electric motor 82. However, the inverter 95 may set the rotation speed of the electric motor 82.

  In the above embodiment, the actual load of the electric motor 82 is fed back from the inverter 95 and the relationship between the output of the electric motor 82 and the rotational speed is corrected, so that the overload is more reliably prevented and the electric drive is efficient. The motor 82 can be driven.

  In the above embodiment, the AC electric motor 82 is shown as the drive source of the hydraulic pump 81. However, the present invention can be applied to a DC electric motor without using the inverter 95.

  Moreover, although the said embodiment showed what detected the load of the suspended load by detecting the pressure in the raising / lowering cylinder 55, it is not restricted to this. For example, a load cell may be provided at the tip of the boom 50, and the load of the suspended load may be detected by the load cell.

  In the embodiment, when the operating levers 84a to 84d are operated in the direction of the end of the movable range when the actuator is located at the end of the movable range, the rotation number of the electric motor 82 is set to the predetermined number of rotations. Although what was set to this was shown, the thing which stops the electric motor 82 is also included.

  In the above embodiment, the battery 83 is used as a drive source for the electric motor 82. However, a commercial power source can be used as the drive source for the electric motor 82.

In the embodiment, the operation levers 84a to 84d and the remote operation device 100 correspond to the operation input means of the present invention.
In the embodiment, the posture / load calculation units 90a and 90a1 correspond to the drive unit state detection unit of the present invention.
Moreover, in the said embodiment, the required torque calculating parts 90c and 90c1 are equivalent to the load detection means of this invention.
Moreover, in the said embodiment, the electric motor output calculating parts 90e and 90e1 and the electric motor rotation speed calculating parts 90f and 90f1 are equivalent to the rotation speed setting means of this invention.

  DESCRIPTION OF SYMBOLS 10 ... Crane apparatus, 40 ... Swing stand, 50 ... Boom, 70 ... Winch, 80 ... Hydraulic supply device, 81 ... Hydraulic pump, 82 ... Electric motor, 84 ... Control valve unit, 84a-84d ... Operation lever, 85 ... Actuation Oil circuit, 90 ... controller, 90a, 90a1 ... posture / load calculation unit, 90b ... operation direction detection unit, 90b1 ... operation state detection unit, 90c, 90c1 ... required torque calculation unit, 90d, 90d1 ... required flow rate calculation unit, 90e , 90e1 ... Electric motor output calculation unit, 90f, 90f1 ... Electric motor rotation number calculation unit, 90g, 90g1 ... Electric motor rotation number output unit, 91 ... Boom length detector, 92 ... Boom angle detector, 93 ... Cylinder pressure detection 94, operation state detector, 95, inverter, 100, remote control device.

Claims (4)

A working machine that drives a drive unit by the power of an electric motor,
Operation input means for inputting an operation for driving the drive unit;
Drive unit state detection means for detecting the state of the drive unit;
Load detection means for detecting a load acting on the drive unit based on the drive direction of the drive unit input to the operation input means and the state of the drive unit detected by the drive unit state detection unit;
The necessary electric motor output is calculated based on the driving speed of the driving unit input to the operation input unit and the load acting on the driving unit detected by the load detecting unit, and the required electric motor output is equal to or less than a predetermined output. In this case, the number of revolutions of the electric motor that is the output of the required electric motor whose output is calculated is set, and when the output of the required electric motor is larger than the predetermined output, A rotation speed setting means for setting the rotation speed;
And an electric motor driving means for driving the electric motor at the rotational speed set by the rotational speed setting means. The rotation speed setting means detects that the drive position of the drive section is located at the end of the movable range by the drive section state detection means, and inputs an operation in the end direction of the movable range of the drive section to the operation input means. Then, irrespective of the drive speed of the drive part input into the operation input means, the rotation speed of an electric motor is set to predetermined rotation speed. The work machine of Claim 1 characterized by the above-mentioned. The electric motor drives a hydraulic pump that distributes hydraulic oil to the hydraulic circuit.
The work machine according to claim 1 or 2, wherein the drive unit is driven by an actuator that is driven by hydraulic oil that flows through a hydraulic circuit. The work machine according to claim 3, wherein the drive unit is a boom that can be raised and lowered by a hydraulic cylinder as an actuator.

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