JP6577928B2 - Electric hoist and life management method of electromagnetic contactor mounted thereon - Google Patents

Description

  The present invention relates to a technique for detecting the life of an electromagnetic contactor in an electric hoist equipped with an electromagnetic contactor for driving a brake.

  As background art of this technical field, there is JP-A-1-123166 (Patent Document 1). In this publication, “a contact resistance detection device for detecting a contact resistance between two opposing contacts is provided, and a contact resistance between the two contacts is detected by the contact resistance detection device while a main current is being applied between the two contacts. Further, the contact life detecting device is characterized in that the life of both the contacts is determined from the detection result of the contact resistance. ”(Claims)

JP-A-1-123166

  Conventionally, visual wear confirmation has been performed as a method for inspecting an electromagnetic contactor in an electric hoist. However, since it is visual, judgment of a part replacement time may differ depending on an inspector. Further, the life determination based on the contact resistance as in Patent Document 1 is the life due to the aging of the contact, and the contact life determination is not accurate unless it is combined with the operation wear life based on the number of switching times (the number of operations). In addition, as one of the methods described in Patent Document 1, there is a method of applying a voltage to a contact by a detection power supply different from the main power supply connected to the contact, but the detection power supply is originally not necessary for the hoisting machine. It is.

  An object of the present invention is to specify the state of an electromagnetic contactor in an electric hoist equipped with an electromagnetic contactor.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-described problems. If an example of an “electric hoist” is given, an inverter that drives the motor, and a frequency control signal for controlling the rotation of the motor by the inverter. And an inverter control unit that outputs rotation of the motor when the current is supplied, and a brake that suppresses the rotation of the motor when the supply of current stops, and the output of the frequency control signal of the inverter control unit. An electric hoist provided with an electromagnetic contactor for supplying electric current to the brake,
The inverter control unit includes a current detection unit that detects a current value on a secondary side of the electromagnetic contactor, a current value detected by the current detection unit, and a contact resistance of the electromagnetic contactor based on a preset voltage value. A contact resistance calculating means for calculating the number of times of operation of the electromagnetic contactor, and a life determining means for the electromagnetic contactor,
The life judging means detects the life of the electromagnetic contactor based on the contact resistance value obtained by the contact resistance calculating means and the number of operations performed by the operation count counting means.

In addition, if an example of "life management method of an electromagnetic contactor mounted on an electric hoist" is given, an inverter that drives the motor and a frequency control signal for controlling the rotation of the motor are output to the inverter. An inverter control unit that releases rotation of the electric motor when current is supplied, and a brake that suppresses rotation of the electric motor when current supply stops, and an output of a frequency control signal of the inverter control unit An electromagnetic contactor for supplying current to the brake, and a life management method for an electromagnetic contactor mounted on an electric hoist comprising:
Detecting the life of the magnetic contactor according to the value of the contact resistance calculating means for calculating the contact resistance of the electromagnetic contactor and the value of the operation frequency counting means for counting the number of operations of the electromagnetic contactor;
After the life detection of the electromagnetic contactor, prohibiting the hoisting operation of the electric hoist;
Outputting life information in response to a request from an external information processing device;
Receiving parts replacement information from an external information processing device;
After receiving the parts replacement information, checking the parts replacement by contact resistance;
The method includes a step of resetting the values of the contact resistance calculating means and the operation frequency counting means after confirming the replacement of parts.

  According to the present invention, the state of an electromagnetic contactor can be specified with high accuracy.

It is a front view showing an example of an electric hoisting machine in which the present invention is used. It is an example of the block block diagram of the electric hoist provided with the contact life detection function of the magnetic contactor of Example 1 of this invention. It is an example of the block diagram of the contact life detection apparatus of Example 1 of this invention. It is an example of the contact life detection flowchart of Example 1 of this invention. It is an example of the flowchart which shows the lifetime management method of the magnetic contactor mounted in the electric winding machine of Example 2 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

First, an outline of an electric hoist equipped with a function for detecting the life of an electromagnetic contactor according to this embodiment will be described with reference to FIG. FIG. 1 is a front view showing an example of an electric hoisting machine in which the present invention is used. In the present specification, the term “lifetime” is a concept that includes not only the time from when a device or component is manufactured until it is damaged or destroyed, but also the time from when the device or component is manufactured to the recommended replacement time. .
The electric hoist includes a hook 1, a wire rope 2, an operation input device 3, a hoisting induction motor 4, an induction motor brake 5, a control device 6, and the like.

  The electric hoisting machine winds and unloads the load attached to the hook 1 by the hoisting induction motor 4 controlled by the control device 6 that takes in the operation command from the operation input device 3. The goods are moved in the direction (Z direction and -Z direction arrows are shown), that is, in the vertical direction.

  Next, the life detection of the magnetic contactor of a present Example is demonstrated using FIGS. FIG. 2 shows a block configuration diagram of an electric hoist equipped with a contact life detection function of the magnetic contactor of the present embodiment. The hoisting induction motor 4 for hoisting and lowering the hook 1 is driven by a three-phase power source (commercial power source) 12 and controlled by a control device 6. An induction motor brake 5 is attached to the hoisting induction motor 4, and the brake 5 is driven by any two phases of a three-phase power source. The brake 5 operates when the electromagnetic contactor 9b of the control device 6 is opened, and opens when the electromagnetic contactor 9b is closed.

  The control device 6 includes an inverter 7 for driving the hoisting induction motor 4, an inverter control unit 8 for controlling the inverter 7, and an electromagnetic contactor (driving coil 9a, normally open contact 9b) for opening and closing the induction motor brake 5. And a communication device 10.

  The inverter control unit 8 gives an appropriate frequency signal to the inverter 7 in accordance with an operation command from the input device 3, and also causes the current to flow through the drive coil 9 a of the magnetic contactor to close the normally open contact 9 b, thereby rotating the brake 5. The winding induction motor 4 is driven by releasing the suppression.

  The communication device 10 transmits / receives data to / from the inverter control unit 8 and communicates with the information processing device 11 such as a personal computer or a tablet, and outputs contact life information according to an external request, or exchanges parts from the outside. Receive information.

  FIG. 3 shows a block diagram of the contact life detecting apparatus of the present embodiment. The contact life detecting device is included in the inverter control unit 8 and includes an operation frequency counting unit 31, a current detecting unit 32, a contact resistance calculating unit 33, and a life determining unit 34. The operation frequency counting unit 31 inputs an operation command for the electric hoist and counts the operation frequency of the electromagnetic contactor.

  The current detector 32 detects a current flowing through the electromagnetic contactor. The contact resistance calculation unit 33 calculates the contact resistance value R of the contact of the electromagnetic contactor from the current value I detected by the current detection unit 32 and the set voltage value V from the relationship of R = V / I. The life determination unit 34 compares the operation number value from the operation number counting unit 31 with the set value for determining the life of the operation number in the comparison unit, and when the operation number value reaches the set value for determining the life of the operation number Judge as life.

  In addition, the life determination unit 34 compares the contact resistance value calculated by the contact resistance calculation unit 33 with the set value for determining the contact resistance life, and the contact resistance value exceeds the set value for determining the contact resistance life. If it is, it will be judged as a life. The life determination unit outputs a life detection signal when it is determined that either the life determination based on the number of operations or the life determination based on the contact resistance is the life.

  FIG. 4 shows a flowchart of contact life detection according to the present embodiment. The inverter control unit 8 is normally in a state of waiting for an operation command from the input device 3. If no operation command is input from the input device 3, the inverter control unit 8 continues the operation command waiting state and receives an operation command (S101). The number of operations is counted (S102).

  And an electric current is detected from the secondary side of the normally open contact 9b of an electromagnetic contactor (S103). The contact resistance value of the normally open contact 9b is calculated from the detected current and a preset voltage value (S104). When the number of operations of the normally open contact 9b counted based on the operation command is compared with the number of operations set in advance as a reference for determining the life, and the number of operations counted based on the operation command reaches the set number of operations Judge as life.

  Moreover, the contact resistance value calculated from the detected current value is compared with a preset contact resistance value that is a criterion for determining the life, and the contact resistance value calculated from the detected current value is equal to or greater than the set contact resistance value. In this case, it is determined that the lifetime is reached (S105).

  Check the operation command when the number of operations counted based on the operation command is less than the set operation number, and when the contact resistance value calculated from the detected current value is within the set contact resistance value range (S106). When the operation command is continuously in the input state, the operation command is waited for release (S107), and after the release, the process returns to S101. If no operation command is input, the process returns to S101.

  In this embodiment, the electromagnetic contactor for the brake of the hoisting motor has been described as an example. However, it is obvious that the present invention can also be applied to the electromagnetic contactor for the brake of the traverse motor or the traveling motor. Further, the power source of the electric hoist is not limited to a three-phase power source but may be a single-phase power source.

  According to the present embodiment, since the life of the magnetic contactor is determined by the life determination based on the number of operations and the life determination based on the contact resistance, the life due to aging and wear of the magnetic contactor can be accurately detected. . And even if it is difficult to judge the replacement of parts when the wear is confirmed by visual inspection, it can be used as a guide for replacement of parts.

  Compared with the contact life detection device described in the cited document 1, this embodiment is a contact life detection of an electromagnetic contactor used in an electric hoist driven by a three-phase power supply (commercial power supply). Since the voltage applied to the contactor is known, the contact life detecting device does not need a means for measuring the voltage.

  The second embodiment relates to a life management method for an electromagnetic contactor mounted on the electric hoist described in the first embodiment. The operation of the electric hoist after the life detection of the magnetic contactor and the life detection output means will be described with reference to FIG. FIG. 5 shows a flowchart of the operation after the contact life detection of this embodiment.

  Even when a winding command is received from the input device 3 after detecting the life of the magnetic contactor, the operation in the winding direction is prohibited (S201). When there is no information output request from the information processing apparatus 11, the output request is waited. When there is an output request (S202), the life information is transmitted to the information processing apparatus 11 via the wireless apparatus 10 (S203). At this time, information such as the manufacturing number and model of the hoist is also sent. By transmitting information such as the serial number or model, it is possible to specify the correspondence with the hoisting machine that specifies the life state. Any information that identifies the hoisting machine is not limited to the production number and model.

  Based on the lifetime information received by the information processing device 11, the electromagnetic contactor of the corresponding motor is replaced, and the component replacement information is input through the input unit of the information processing device 11 (S204). After the input, the component replacement information is taken into the inverter control unit 8 from the information processing device 11 via the wireless device 10 (S205).

  And when the inverter control part 8 takes in component replacement information, it supplies an electric current to the drive coil 9a of an electromagnetic contactor, and closes the normally open contact 9b. If the contact resistance value is not improved compared to the current value when the normally open contact 9b is closed, the reception of replacement information is awaited. If the contact resistance value is improved (if it is within the initial value range), the parts replacement is completed. The life information (the number of operations and the contact resistance value) is reset (S206). Then, after resetting, the count value of the number of operations is incremented by 1 (S207), and the winding operation prohibition state is canceled (S208).

  5 shows the output of the life detection state and the confirmation of parts replacement by the wireless device 10 and the communication device 11, but the output of the life detection state is after the winding operation prohibition (S201) is performed. Alternatively, a buzzer or a display unit of the inverter control unit 8 not shown may be used. In the case of the output of the life detection state on the buzzer or the display unit, confirmation of component replacement may be performed by an operation button mounted on the inverter control unit 8 (not shown).

  According to this embodiment, after receiving the component replacement information, the contact resistance value of the electromagnetic contactor is confirmed to be improved and the life information is reset, so that the electromagnetic contactor can be reliably replaced.

  Also, save the time or number of days the hoist was used until the magnetic contactor was actually replaced, and display the time or number of days mentioned above on the display means connected via wireless communication or wire. You may display as a time. Since the time or the number of days corresponding to the actual use environment is displayed, there is an advantage for the user. It also makes it easier to plan for maintenance.

1: Hook 2: Wire rope 3: Input device 4: Induction motor 5: Induction motor brake 6: Control device 7: Inverter 8: Inverter controller 9a: Drive coil 9b of electromagnetic contactor: Normally open contact of electromagnetic contactor 10: Wireless device 11: Information processing device 12: Three-phase power supply 31: Operation frequency counting unit 32: Current detection unit 33: Contact resistance calculation unit 34: Life determination unit

Claims (7)

An inverter that drives an electric motor;
An inverter control unit that outputs a frequency control signal for controlling rotation of the electric motor to the inverter;
A brake that releases rotation of the electric motor when current is supplied and suppresses rotation of the electric motor when supply of current stops;
An electric hoist comprising an electromagnetic contactor for supplying a current to the brake in accordance with an output of a frequency control signal of the inverter control unit,
The inverter control unit
Current detection means for detecting a current value on the secondary side of the electromagnetic contactor;
A contact resistance calculating means for calculating a contact resistance of the electromagnetic contactor from a current value detected by the current detecting means and a preset voltage value;
An operation number counting means for counting the number of operations of the electromagnetic contactor;
Comprising a life judging means for the magnetic contactor,
The life judging means is an electric hoist that detects the life of the electromagnetic contactor based on the contact resistance value obtained by the contact resistance calculating means and the number of operations performed by the operation count counting means. In the electric hoist according to claim 1,
The life determination means compares the contact resistance value calculated by the contact resistance calculation means with a preset contact resistance value that is a reference for life determination, and the calculated contact resistance value is equal to or greater than the preset contact resistance value. In this case, it is determined that the service life is reached, and the operation count counted by the operation count counting means is compared with a preset operation count serving as a basis for determining the life, and the counted operation count reaches the preset operation count. If it does, the electric hoist will be judged as the life. In the electric hoist according to claim 1,
The electric motor is an electric hoist that is a hoisting electric motor, a traversing electric motor or a traveling electric motor. In the electric hoist according to claim 1,
An electric hoist in which three-phase power is supplied to the inverter, and any two phases of the three-phase power are supplied to the electromagnetic contactor. An inverter that drives an electric motor, an inverter control unit that outputs a frequency control signal for controlling rotation of the electric motor to the inverter, and when electric current is supplied, rotation of the electric motor is released and supply of electric current is stopped An electromagnetic contactor mounted on an electric hoist comprising: a brake that suppresses rotation of the electric motor; and an electromagnetic contactor that supplies a current to the brake in accordance with an output of a frequency control signal of the inverter control unit. A life management method,
Detecting the life of the magnetic contactor according to the value of the contact resistance calculating means for calculating the contact resistance of the electromagnetic contactor and the value of the operation frequency counting means for counting the number of operations of the electromagnetic contactor;
After the life detection of the electromagnetic contactor, prohibiting the hoisting operation of the electric hoist;
Outputting life information in response to a request from an external information processing device;
Receiving parts replacement information from an external information processing device;
After receiving the parts replacement information, checking the parts replacement by contact resistance;
A method for managing the life of an electromagnetic contactor mounted on an electric hoist comprising the step of resetting the values of the contact resistance calculating means and the operation frequency counting means after confirming component replacement. In the life management method of the magnetic contactor mounted on the electric hoist according to claim 5,
Detecting the life of the magnetic contactor comprises:
Detecting a current value on a secondary side of the electromagnetic contactor;
Calculating the contact resistance of the magnetic contactor from the detected current value and a preset voltage value;
Counting the number of operations of the magnetic contactor;
The calculated contact resistance value is compared with a preset contact resistance value that is a criterion for determining the service life. If the calculated contact resistance value is greater than or equal to the preset contact resistance value, the service life is determined and counted. Compared with the number of operations and a preset number of operations, which is a criterion for determining the life, and when the counted number of operations reaches the preset number of operations, it is mounted on an electric hoist equipped with a step for determining the life Life management method for magnetic contactors. In the life management method of the magnetic contactor mounted on the electric hoist according to claim 5,
The step of confirming the part replacement by contact resistance is as follows:
Detect the secondary current value of the magnetic contactor,
Calculate the contact resistance of the electromagnetic contactor from the detected current value and a preset voltage value,
A method for managing the life of an electromagnetic contactor mounted on an electric hoisting machine, which is confirmed by confirming that the calculated contact resistance value is within an initial value range.

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