JPH0745931Y2 - Constant current controller for magnetic field press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a constant current control of a magnetic field press used in the manufacture of magnets, and more particularly to a constant current control device that allows a constant demagnetizing current to flow.

[Prior Art] A magnetic field press is one in which a strong magnetic field is applied to press a magnetic material to perform press molding, and has been conventionally performed as one step of a magnet manufacturing line. In this magnetic field press, accurate magnetic field strength is not so much required in the normal rotation magnetic field at the time of orientation, but the magnetic field for reverse demagnetization requires accurate magnetic field control. The control of the magnetic field is, in other words, the control of the current, and in order to perform demagnetization reliably, it is necessary that the reversal demagnetization magnetic field current is controlled to be constant. If the demagnetization is not performed sufficiently and surely because it is not performed, the die of the press cannot operate reliably, which may cause a trouble when the molded product is taken out in the next step.

Therefore, conventionally, in order to control the reversal demagnetization magnetic field current of the magnetic field press constant, as shown in FIG. 2, a commercial power supply (AC 200 V) a is used as the reversal demagnetization magnetic field power supply of the magnetic field press. The reverse demagnetizing magnetic field current from the power supply a is rectified by the transformer b and the thyristor c in both waves, and the load coil d
A forward magnetic field current supplied from a power source (not shown) and a reverse demagnetizing magnetic field current supplied from a commercial power source a are alternately flowed, and the conduction phase angle of the thyristor c is controlled by a command from the constant current substrate e. Load coil d by
It is adopted that the reversal demagnetization magnetic field current is constantly controlled. f is a shunt resistance.

In the magnetic field press, one cycle of the press is 10 to 20 seconds and the current is 10 to 30 A, during which the magnetic field application time is short, and in particular, the reversal demagnetizing field current is 1 to 2 seconds. is there. If a stable reversal demagnetizing magnetic field current is passed for only this 1 to 2 seconds, demagnetization can be surely performed.

[Problems to be solved by the invention] However, even one magnetic field press requires a very large amount of electric power, but normally, there are a plurality of magnetic field presses installed in one factory and they are operated randomly. , Even if the application time of the magnetic field is short, if multiple machines are operating randomly, a voltage drop will be unavoidable in the power supply on the primary side,
A large voltage drop is likely to occur and the voltage tends to become unstable. If the voltage on the power supply side fluctuates or becomes unstable, the reversal demagnetization magnetic field current flowing through the load coil d will not be constant, and demagnetization cannot be performed reliably. Trouble occurs when taking out, which obstructs the flow of the automatic machine and causes damage to the mold.

In this way, in the current situation where multiple units are deployed in one factory, the power supply on the primary side of the commercial power supply is limited,
In order to ensure reliable demagnetization even when multiple machines are operating randomly, a major issue is how to flow a stable reverse demagnetization magnetic field current during demagnetization. There is.

Therefore, the present invention eliminates the voltage fluctuation on the power supply side even when it is used in a place where there is voltage fluctuation on the power supply side, etc., and allows a constant constant demagnetizing magnetic field current to flow through the load coil during demagnetization. Therefore, it is intended to ensure demagnetization.

[Means for Solving the Problems] In order to solve the above problems, the present invention uses a rechargeable battery as a magnetic field power source for reversal demagnetization, and applies reversal demagnetization magnetic field current from the battery to a load coil. A main circuit for supplying a constant current value to the main circuit, and a thyristor having a switching action of the reversal demagnetizing magnetic field current to the load coil are provided. A constant voltage power supply circuit for the floating charge of the battery that always charges the battery, a thyristor control circuit that blocks the counter electromotive voltage from the load coil and the reverse voltage at the time of polarity change, and the life of the battery. The controller has a built-in alarm circuit that informs that the battery capacity has deteriorated. Through the thyristor, the reverse demagnetizing magnetic field current stabilized by the constant current control circuit is connected. The configuration is such that it flows through the load coil.

[Operation] The reverse demagnetizing magnetic field current supplied from the battery flows to the load coil, and the constant reverse current controlling circuit stabilizes the reverse demagnetizing magnetic field current during that time, so that a constant reverse demagnetizing magnetic field current is applied to the load coil. Can be flushed. In addition, the battery is a constant current power supply, and the battery can be charged during the suspension period of the magnetic field press with a commercial power supply or the like used as a constant voltage power supply for floating charging of the battery built in the control device. , The voltage of the battery does not fluctuate, therefore, the reverse demagnetizing magnetic field current extracted from the battery as a constant current power source during the operation of the magnetic field press becomes a constant current, and
Since it is stabilized by the constant current control circuit as described above,
A constant reverse demagnetizing magnetic field current can be passed through the load coil. A forward rotation magnetic field current from a required power supply is made to flow through the load coil, and the forward rotation magnetic field current and the reverse demagnetization magnetic field current from the battery due to the switching action of the thyristor are alternately made to flow, and press molding is performed. A demolding action by the action and demagnetization is performed. When demolding is performed by demagnetization, the thyristor control circuit built into the controller blocks the counter electromotive voltage from the load coil and the reverse voltage at the time of polarity conversion. A magnetic field current can be passed. In addition, the alarm circuit informs you of the deterioration of the battery capacity, so you can know the battery life and use the battery with peace of mind.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which a constant current power supply composed of an automobile battery 1 is used as a magnetic field power supply for reversing demagnetization of a magnetic field press, and a reversing demagnetization magnetic field current flowing from the battery 1 is used. In the main circuit 3 supplied to the load coil 2, a constant current control circuit 4 including a current control transistor 5 and a shunt resistor 6 for stabilizing the reverse demagnetizing magnetic field current,
A thyristor 7 for performing a switching action is provided, and the reverse demagnetizing magnetic field current from the positive side of the battery 1 is stabilized by the constant current control circuit 4, enters the load coil 2 through the thyristor 7, and the load coil 2 causes the battery 1 The control device 8 is connected to the main circuit 3 described above.

The control device 8 includes a constant voltage power supply circuit for floating charging of the battery 1 for constantly charging the battery 1, a thyristor for blocking a counter electromotive voltage from the load coil 2 and a reverse voltage at the time of polarity switching. Control circuit and battery 1
In order to keep the output time from
The output time setting timer that keeps the output current for a certain time by turning off, and the battery 1 will reach the end of its life due to corrosion and aging of electrodes, electrolyte, etc. if it is used for a long time. It is configured to have a built-in alarm circuit for notifying the deterioration of battery capacity.

After supplying a forward rotation magnetic field current to the load coil 2 from a power source (not shown) to operate the polar press to press the magnetic material,
When the demagnetization is performed to take out the molded product, the reverse demagnetization magnetic field current is supplied from the battery 1 to the load coil 2, and the output time is set by the timer circuit built in the control device 8. Further, the reverse demagnetizing magnetic field current output from the battery 1 is kept constant by the constant current control circuit 4 and supplied to the load coil 2. During the cycle of the magnetic field press, the load coil 2 is alternately supplied with a forward magnetic field current supplied from a power source (not shown) and a reverse demagnetizing magnetic field current supplied from the battery 1 to perform press forming and demolding. The releasing action is performed by magnetism, but as described above, the load coil 2
Since the reversal demagnetizing magnetic field current is kept constant, demagnetization can be stably and sufficiently and surely performed. As a result, the molded product can be taken out smoothly in the next step and the mold is not damaged.

Since the reversing demagnetizing magnetic field current flowing in the load coil 2 is supplied from the battery 1, the battery 1 is always floating-charged. In this case, a commercial power source is used as the power source for charging the battery 1, and During the rest time, the battery 1 is charged by the constant voltage power supply circuit built in the control device 8. In this way, the reverse demagnetizing magnetic field current is taken out from the battery 1 as the constant current power source during the operation of the magnetic field press.

[Effects of the Invention] As described above, according to the constant current control device for a magnetic field press of the present invention, a rechargeable battery is used as a magnetic field power source for reverse demagnetization, and reverse demagnetization is performed from the battery to a load coil. In the main circuit for supplying the magnetic field current, a constant current control circuit for keeping the current value of the reversal demagnetization magnetic field current constant, and a thyristor having a switch action so as to allow the reversal demagnetization magnetic field current to be provided, and further to the main circuit, A constant voltage power supply circuit for floating charging of the battery that always allows the battery to be floatingly charged, a thyristor control circuit that blocks a counter electromotive voltage from the load coil, and a reverse voltage when the polarity is changed, and the life of the battery. Is connected to a control device that has an alarm circuit that notifies that the battery capacity has deteriorated. Since the terry is floatingly charged, there is no voltage fluctuation on the power supply side when using this battery, and the reversal demagnetization magnetic field current from this battery can be stabilized by the constant current control circuit and supplied to the load coil. Therefore, the reversal demagnetization magnetic field current is also stable, and demagnetization can be performed sufficiently and reliably in a short time, which causes troubles when taking out a molded product between molds due to demagnetization failure. It is possible to prevent the occurrence of damage to the mold and also prevent accidents of damage to the mold, and it is extremely effective when the voltage drop of the primary side power supply cannot be avoided at the site where multiple machines are operating randomly. In addition, the thyristor control circuit built into the control device can prevent the counter electromotive voltage from the load coil and the reverse voltage at the time of polarity change. Since capacity are to inform a decrease, it can be electrodes prolonged use batteries, with confidence to be able to easily know that you have reached the life corrosion aging of the electrolyte solution or the like using the battery.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a constant current control device for a magnetic field press of the present invention, and FIG. 2 is a schematic diagram of a conventional example. 1 ... Battery, 2 ... Load coil, 3 ... Main circuit,
4 ... Constant current control circuit, 7 ... Thyristor, 8 ... Control device.

Claims (1)

[Scope of utility model registration request] 1. A constant current control that uses a rechargeable battery as a magnetic field power source for reversal demagnetization and supplies a reversal demagnetization magnetic field current from the battery to a load coil with a constant current value. A circuit and a thyristor having a switching action of the reversal demagnetization magnetic field current to the load coil are provided, and further, the main circuit is configured to constantly float charge the battery, and a constant voltage for floating charge of the battery. Connects the power supply circuit, the thyristor control circuit that blocks the back electromotive voltage from the load coil and the reverse voltage at the time of polarity change, and the control device that has the built-in alarm circuit that informs the battery life and indicates the deterioration of the battery capacity. A constant current control device for a magnetic field press having the above-mentioned configuration.