JPH0747467B2 - Balanced cargo handling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention realizes an equilibrium state for a work having an arbitrary weight by an elevator to output a force commensurate with the weight, and a person can work the work. The present invention relates to an equilibrium cargo handling device capable of directly raising and lowering a work by applying a force to the work.

[Conventional technology]

In the conventional balanced cargo handling apparatus, for example, when the load detector fails due to a wire breakage or the like, in order to prevent the apparatus from running out of control, an emergency stop is made and the operation is stopped at the same time when the failure is detected.

[Problems to be Solved by the Invention] However, if a detector malfunctions during operation of the balanced cargo handling apparatus, the work piece remains stuck in a dangerous state like a heavy workpiece is lifted, and repairing is not easy.

The present invention has been made to solve the above-mentioned drawbacks of the prior art. When the load detector or the acceleration detector fails, the equilibrium cargo handling can prevent the device from running out of control and release the dangerous state. The purpose is to provide a device.

[Means for Solving the Problems]

In order to achieve the above object, an equilibrium cargo handling apparatus according to the present invention includes an elevator that raises and lowers a work, a load detector that detects a load acting on the elevator, and an acceleration detector that detects an acceleration of the work to move up and down. A speed detector that detects the rotation speed of the elevator, a position detector that detects the rotational position of the elevator, a speed commander that outputs a rotation speed command of the elevator, the speed commander and each of the detections. The driving force of the elevator is calculated as a lever mode based on the output of the speed commander, a position mode for holding the work in a stopped state, and a balance mode for driving according to the change in the load, based on the output with the loader. A mode operation circuit and a mode selection circuit for selecting an operation mode obtained by the mode operation circuit based on output signals of the speed commander and the load detector. In 衡荷 role device, the failure judgment means for judging a failure by the signal from the load detector and the acceleration detector is provided, it is characterized in that to prohibit a selection of the balancing mode to the mode selection circuit.

[Action]

According to the present invention configured as described above, when the load detector or the acceleration detector fails, the failure determination means prohibits the mode selection circuit from selecting the balance mode using the detection signals of these detectors. Prevent runaway of the device and enable lever mode operation without using the detection signals of the load detector and acceleration detector so that the suspended work can be lowered to the ground to release the dangerous condition.

〔Example〕

A preferred embodiment of the balancing device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a balanced cargo handling apparatus according to an embodiment of the present invention.

In FIG. 1, the elevator 10 includes a motor 12 and the motor 12
And a drum 16 which is driven to rotate and winds up and pays out the wire 14. The wire 14 is equipped with a speed command device 20 for outputting a speed command signal R corresponding to the operation amount of the lever 18, an acceleration detector 22, and a load detector 24 at the tip end thereof. The work 26 is hung and moved up and down via the acceleration detector 22 and the load detector 24.

The speed command signal R output from the speed command device 20 is input to the lever mode calculation unit 32 of the mode calculation circuit 30 for calculating the operation mode of the motor 12 and the mode selection circuit 40. The acceleration detector 22 obtains the acceleration when the work 26 moves up and down, and inputs the acceleration signal a to the lever mode calculation unit 32, the weight storage calculation unit 42, and a failure determination circuit 44 as a failure determination unit whose details will be described later. To do. In addition, the load detector 24
Detects the load acting on the motor 12 of the work 26 and outputs the load signal F to the balance mode calculation unit 36 of the mode calculation circuit 30.
Balance stationary mode calculation unit 38 and weight storage calculation unit 42,
Input to the mode selection circuit 40 and the failure determination circuit 44.

On the other hand, the motor 12 is provided with a position detector 46 that detects the rotational position (rotation amount) of the motor 12 and a speed detector 48 that detects the rotational speed of the motor 12. The rotational position signal x output by the position detector 46 is the mode selection circuit.
40 position mode calculator 34, balance still mode calculator 38
And to the mode selection circuit 40. Also a speed detector
The rotation speed signal v output by 48 is input to the lever mode calculation unit 32, the position detector 46, and the balance mode calculation unit 36 of the mode calculation circuit 30. Then, the output signals of the mode operation units 32, 34, 36, 38 of the mode operation circuit 30, the weight storage operation unit 42, and the failure determination circuit 44 are input to the mode selection circuit 40. The mode selection circuit 40 includes a speed command signal R, a rotational position signal x, a load signal F, and a weight storage calculation unit.
In response to the output signals of 42 and the failure determination circuit 44, one of the mode operation units of the mode operation circuit 30 is selected and the output signal is input to the addition point 60.

The motor 12 is controlled by the motor driving device 50. The motor drive device 50 has a drive circuit 52 and an adder 54, and the rotational speed signal v from the speed detector 48 is negatively fed back to the adder 54. Further, the rotation speed signal v is input to the differentiator 56. The differentiator 56 differentiates the input rotation speed signal v and negatively feeds it back to the addition point 60.

The failure determination circuit 44, as shown in FIG. 2, includes an acceleration detector failure determination unit 62 that detects a failure of the acceleration detector 22, and a load detector failure determination unit 64 that detects a failure of the load detector 24. It consists of

The acceleration detector 22 has a well-known structure in which a bridge is formed by using four pieces of strain gauges, and the voltage VP at the point P serves as an inverting input terminal of the operational amplifier 66 for discriminating whether the voltage is normal or abnormal. It is adapted to be input to the non-inverting input terminal of the operational amplifier 68. The non-inverting input terminal of the operational amplifier 66 is supplied with the normal voltage minimum value V _{1 at the} point P as a reference voltage, and the inverting input terminal of the operational amplifier 68 is supplied with the normal voltage maximum value V _{2 at the} point P as a reference. It is given as a voltage.

The voltage VQ at the point Q is input to the inverting input terminal of the operational amplifier 70 and the non-inverting input terminal of the operational amplifier 72. Then, the normal voltage minimum value V _{3 at} point Q is input to the non-inverting input terminal of the operational amplifier 70, and the normal voltage maximum value V _{4 at} point Q is input to the inverting input terminal of the operational amplifier 72. The voltage VS at the S point is input to the inverting input terminal of the operational amplifier 74, and the normal voltage minimum value V ₅ at the S point is input to the non-inverting input terminal of the operational amplifier 74 as a reference voltage. ing.

The outputs of the operational amplifiers 66 and 68 are input to the OR circuit 76, the outputs of the operational amplifiers 70 and 72 are input to the OR circuit 78, and the output sides of these OR circuits 76 and 78 are OR circuits. It is connected to 80 input terminals. The output side of the OR circuit 80 is connected to the input side of the OR circuit 82 together with the output side of the operational amplifier 74. Then, the output of the OR circuit 82 becomes an output signal of the acceleration detector failure determination unit 62 and is input to one input terminal of the NOR circuit 84. The output signal of the load detector failure determination unit 64 is input to the other input terminal of the NOR circuit 84. Further, the output signal of the NOR circuit 84 is
Is input to the mode selection circuit 40 as an output signal of the. The structure of the load detector 24 is similar to that of the acceleration detector 22, and the structure of the load detector failure determination unit 64 is similar to that of the acceleration detector failure determination unit 62. Omit it.

The operation of the embodiment configured as described above is as follows.

The mode selection circuit 40 has, for example, a configuration in which a mode selection circuit and a determination circuit shown in Japanese Patent Application No. 62-283159 filed by the applicant of the present application are combined, and the operation mode of the motor 12 is determined based on an input signal. And a switching unit for switching and selecting the mode operation unit of the mode operation circuit 30 (both not shown). The mode operation circuit 30
The details of the operation contents of each mode operation unit 32, 34, 36, 38 in the above are described in Japanese Patent Application No. 62-283159 and Japanese Patent Application No. 63-20398 filed by the applicant of the present application. Since it is not directly related to the gist, its description is omitted.

The mode selection circuit 40 reads the speed command signal R output from the speed command device 20 at regular intervals and determines whether or not the absolute value | R | of the speed command signal R is greater than the set value R ₀ ( Fig. 3, step 100). If the set value R ₀ is close to zero and | R |> R ₀ , it is determined that the lever 18 of the speed commander 20 is being operated, and the output signal of the lever mode calculation unit 32 is set to the addition point 60. To drive the motor 12 in the lever mode. If | R | ≦ R ₀ , it is determined that the lever 18 has not been operated, and the output signal of the failure determination circuit 44 is fetched to determine whether the acceleration detector 22 or the load detector 24 has a failure. It is determined (step 111).

If the acceleration detector 22 is not defective, voltage P at point P
Is V ₁ <VP <V ₂ . Therefore, the outputs of the operational amplifiers 66 and 68 input to the OR circuit 76 are both "L", and the OR circuit
76 outputs "L". Also, the voltage VQ at the Q point is V ₃ <VQ
Since <V ₄ , the outputs of the operational amplifiers 70 and 72 are “L”. Therefore, the inputs of the OR circuits 78 are all "L", and the OR
The output of the circuit 78 also becomes "L". Therefore, the OR circuits 76, 78
The OR circuit 80, which receives the output signal of, inputs “L” to one input terminal of the OR circuit 82. Furthermore, the voltage VS at the S point
In the normal case, since VS> V ₅ , the output of the operational amplifier 74 is “L”. Therefore, the OR circuit 82 is an acceleration detector.
If 22 is normal, both input terminals "L" input,
"L" is output as NO from the acceleration detector failure determination unit 62
Input to R circuit 84.

On the other hand, when the load detector 24 is normal, the load detector failure determination unit 64 is “L” like the acceleration detector failure determination unit 62.
Is input to the NOR circuit 84. Therefore, when the acceleration detector 22 and the load detector 24 are normal, the NOR circuit 84 outputs “H” indicating that the detectors are normal to the mode selection circuit 40 as an output signal of the failure determination circuit 44. When the "H" is input from the failure determination circuit 44, the mode selection circuit 40 determines that there is no failure in the detector.

However, the VP of the acceleration detector 22 does not satisfy V ₁ <VP <V ₂ ,
When VS does not satisfy V ₃ <VQ <V ₄ or when VS> V ₅ , the output signal of the OR circuit 82 becomes “H”. Therefore, the NOR circuit 84 output signal, which is the output signal of the failure determination circuit 44, is
It indicates that the detector is out of order and becomes "L" which prohibits the selection of the balance mode. The same applies when the load detector 24 fails, or when both the acceleration detector 22 and the load detector 24 fail. Then, the mode selection circuit 40
When "L" is input from the failure determination circuit 44, it determines that the detector has failed, and selects the position mode calculation unit 34 by the determination branch shown in FIG. 3 to drive the motor 12 in the position mode. To prevent runaway of the device.

As a result, if one or both of the acceleration detector 22 and the load detector 24 fails, the position mode continues unless the lever 18 is operated, and the motor 12 holds the workpiece 26 at a fixed position in the air. . Then, the mode selection circuit 40
When the lever 18 is operated and it is determined that | R |> R ₀ in the next data acquisition cycle, the input signal of the lever mode calculation unit 32 is input to the addition point 60. At this time, in the case of performing the shake stop in the lever mode by the acceleration signal, the acceleration may be set to zero. Therefore, the motor 12 is driven in the lever mode, the work 26 suspended in the air by the wire 14 can be lowered to the ground, and the dangerous state can be released. Further, since the work 26 is not suspended, the device can be easily repaired.

If the mode selection circuit 40 determines in step 111 that the detector has not failed, the output signal of the weight storage calculation unit 42 is read, and the weight storage calculation unit 42 completes the storage of the weight W ₀ of the workpiece 26. Judge whether or not (step 11)
2). When the signal indicating the weight W ₀ of the work 26 is not input from the weight storage calculating unit 42, it is determined that the lever operation for lifting the work 26 from the ground is finished, and the weight is stored in the weight storing calculating unit 42. It is stored (step 113) and the mode is changed to the position mode.

When the weight storage calculation unit 42 stores the weight W ₀ , the process proceeds from step 113 to step 114, and the absolute value of the difference between the load signal F of the load detector 24 and the weight W ₀ is less than the set value F ₀ . Find out if it's big. If | F−W ₀ |> F _0, it is determined that the force exerted by the human hand is applied to the work 26, the timer is restarted (step 115), and the motor 12 is driven in the balance mode. That is, the mode selection circuit 40 selects the balance mode calculation unit 36 and inputs the output signal of the balance mode calculation unit 36 to the addition point 60.

If | F−W ₀ | ≦ F ₀ is determined in step 114, the routine proceeds to step 116, where it is checked whether or not the balance mode has been entered once or more. When the balance mode has not been entered even once, it is determined that the position mode is continuing, and the position mode is maintained. In step 116, when the balance mode has been entered more than once, it is determined whether the timer time has reached the set time Ta (step 117). If the time of the timer has not reached Ta, the mode selection circuit 40 determines that | F−W ₀ | ≦ F ₀ is temporarily satisfied while the person is moving the work 26 by hand. , Continue balance mode. However, when the timer time has reached Ta, it is determined that the human hand has moved away from the work 26, the balance still mode is entered, and the output signal of the balance still mode computing unit 38 is set to the addition point 60. input.

If the light emitting diode that lights up when the detector fails is connected to the output diagrams (output terminals of the OR circuit 82) of the acceleration detector failure determination unit 62 and the load detector failure determination unit 64, which one will be detected. You can easily know if the vessel has failed.

〔The invention's effect〕

As described above, according to the present invention, when the acceleration detector or the load signal fails, the selection of the balance mode utilizing these detection signals is prohibited to prevent the runaway of the device and the lever mode Since it has become possible to operate, the suspended work can be lowered to the ground to release the dangerous condition.

[Brief description of drawings]

FIG. 1 is a block diagram of a balanced cargo handling apparatus according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of a failure judgment circuit, and FIG. 3 is a flow chart showing the operation of a mode selection circuit. 10 ... Elevator, 12 ... Motor, 20 ... Speed commander, 22 ...
… Acceleration detector, 24 …… Load detector, 26 …… Workpiece, 30
...... Mode calculation circuit, 32 ...... Lever mode calculation section, 34 ...
… Position mode calculator, 36 …… Balance mode calculator, 38
…… Balance static mode operation unit, 40 …… Mode selection circuit, 42 …… Weight memory calculation unit, 44 …… Failure determination means (fault determination circuit).

Claims (1)

[Claims] 1. A lift for raising and lowering a work, a load detector for detecting a load acting on the lift, an acceleration detector for detecting acceleration of the work ascending and descending, and a speed detector for detecting a rotation speed of the lift. Device, a position detector that detects a rotational position of the elevator, a speed commander that outputs a rotation speed command of the elevator, and a drive of the elevator based on outputs of the speed commander and the detectors. A mode calculation circuit for calculating force as a lever mode based on the output of a speed commander, a position mode for holding the work in a stopped state, and a balance mode driven according to changes in the load, the speed commander and the load In a balanced cargo handling apparatus having a mode selection circuit for selecting an operation mode obtained by the mode operation circuit based on an output signal from the detector, the acceleration detector and the front Failure determination means for determining a failure by a signal from the load detector provided, balancing handling device, characterized in that to prohibit a selection of the balancing mode to the mode selection circuit by a signal from the fault determining means.