JPS6190403A - Method for driving solenoid and device therefor - Google Patents

Abstract

PURPOSE:To improve a responsing performance by enhancing a speed of the rising and falling characteristics of a solenoid by applying an overexcited voltage foldedly at initial operation and blocking a holding voltage whidth is lower than the overexcited voltage to produce a no-voltage state non-operation state. CONSTITUTION:A current I of a solenoil 2 in preparatory state gives a plunger 2a a slight force in a moving direction. Under such condition, a driving signal Vi changes into 'H' level, a relay 15 actuates a switching means 5 and a time limit circuit 13 generates the output of 'H' level for a constant time so that a relay 14 and a switching means 3 continue to apply an overexcited voltage Vh to the solenoid 2 and the plunger 2a moves from an original position PO and stops at the predetermined movement position P1. After that, when the drive signal Vi changers from 'H' level to 'L' level for presetting a non- operation state, the fall of the drive signal Vi gets a flip-flop 19 in a reset state so that a relay 20 makes the switching means 5 off-state and no voltage is applied to the solenoid 2 at all.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method and device for driving a solenoid for driving an electromagnetic solenoid, an electromagnetic brake, an electromagnetic clutch, and the like.

BACKGROUND OF THE INVENTION AND PRIOR ART When a machine to be controlled is operating at a high speed, a solenoid required to control its operation must also operate at a high speed that can follow the speed. Therefore, solenoids for this type of use are always required to have high-speed response.

Conventionally, such high-speed response has generally been solved by applying an overexcitation voltage that is sufficiently higher than the rated voltage to the solenoid at startup.

However, in this method of applying an overexcitation voltage, an increase in the overexcitation voltage does not necessarily lead to an effective improvement in the rise response characteristics due to magnetic saturation of the iron core portion of the solenoid, and there are also the following drawbacks.

That is, when the overexcitation voltage is increased, the moving speed of the plunger increases, and when the plunger collides with the stopper, the impact force increases, and the life of the plunger is significantly shortened. Furthermore, the withstand voltage and current capacity of the internal elements of the drive circuit must be increased in response to the overexcitation voltage, making the drive circuit expensive. For these reasons, there are certain limits to the simple method of applying an overexcitation voltage.

OBJECTS OF THE INVENTION AND SOLUTIONS THEREOF Therefore, an object of the present invention is to improve the rising and falling characteristics, that is, the response characteristics, of a solenoid without causing the above-mentioned conventional drawbacks.

Therefore, in the present invention, a certain preparatory voltage is applied in advance to the solenoid in a preparatory state, a preparatory current is applied to the solenoid by this preparatory voltage, and the plunger is energized with a light force in the direction of movement in advance. During operation, over-excitation voltage is applied in a superimposed manner to speed up the start-up characteristics, and when setting the solenoid to a non-operating state, a holding voltage lower than the over-excitation voltage is cut off, and the solenoid is placed in a no-voltage state. By doing so, the falling characteristic is made faster. of course,
In the subsequent preparation state, the preparation voltage is again applied to the solenoid. In this way, the rise and fall characteristics of the solenoid can be made as fast as possible.

Configuration of the Invention Hereinafter, the configuration of the present invention will be specifically explained based on the drawings.

First, FIG. 1 shows a solenoid drive device 1 of the present invention. The solenoid 2, which is the object to be driven by this solenoid drive device l, is connected to ground 11 at one end and branched at the other end. It is connected to the power supply terminal 7 and the power supply terminal 8 of the holding voltage VZ, respectively. Note that a diode 9.10 for preventing backflow to the power supply terminal 6 is interposed between the switch means 4.5 and the branch point. Also, for the solenoid 2, the back electromotive force absorption element 21
are connected in parallel.

The input terminal 12 of the drive signal Vi is connected to a relay 14 for driving the switch means 3 through a time limit circuit 13 such as a one-shot multi-by-break circuit, and is also connected to a relay 14 for driving the switch means 5. It is also connected to the input side of a control circuit 16 for driving the relay 15 and the switch means 4.

This control circuit 16 includes two one-shot multi-by-breaks 17, 18 and a flip-flop 19. That is, the input terminal 12 of the above signal is connected to the set input terminal of the flip-flop 19 via one-shot multi-by-breaks 17 and 18, and directly.
It is also connected to the recent input terminal of the flip-flop 19. The output side of this flip-flop 19 is connected to a relay 20 for driving the switch means 4.

Operation of the Invention Next, the operation of the solenoid drive device 1 will be explained with reference to FIG. 2 over time t.

``H'' level '8A movement (8% V i 4 <'L
``When the level changes, the one-shot multi-bye break 17 of the control circuit 16 generates a ``H'' level pulse signal. is delayed by the pulse width of the "H" level, and after the delay time ΔT, a pulse signal of the "H" level is generated, thereby causing the flip-flop 1 to
Set 9 to cent status. For this reason, the relay 20
In response to the output signal of the "I(" level) from the flip-flop 19, the switch means 4 is set to the on state.In this way, the preparation voltage Vp is applied to the solenoid 2 as the input voltage ■, and this As a result, the current I of the solenoid 2 in the preparation state is the preparation current rp.This preparation current 1p has a magnetic flux that does not cause the plunger 2a to move, and lightly urges the plunger 2a in the moving direction. .

In this preparation state, when the drive signal Vi changes to "H" level, the relay 15 turns on the corresponding switch means 5. In this way, this switch means 5
As long as the drive signal Vi remains at the "H" level, it remains on.

On the other hand, when the drive signal Vi changes to the "H" level, the time limit circuit 13 generates an output of the "H" level for a certain period of time T1, so that the relay 14 and the switch means 3
continues to apply the overexcitation voltage vh to the solenoid 2 over the fixed period Tl. By applying the overexcitation voltage vh in this initial operating state, the plunger 2a of the solenoid 2 moves from the original position PO after a short time delay and stops at a predetermined movement position P1. When the movement to the predetermined movement position P1 is completed, the plunger 2a reaches the predetermined movement position P1 at a speed that is slightly biased by the preparatory current 1p compared to the conventional simple overexcitation voltage drive method.
When moving to , the excitation current becomes temporarily smaller,
It rises again to the maximum value due to the overexcitation voltage vh. After that, the overexcitation voltage vh disappears, and the holding voltage v
2 is applied, the solenoid 2 holds the plunger 2a at the moving position P1 over the period of the H'' level of the drive signal Vi by the holding current rp, and enters the operating state.

After that, the drive signal Vi is set to 1 to set the non-operating state.
When the level changes from "H" level to "L" level, the switch means 3.5 is already in the off state, and the flip-flop 19 goes into the reset state with the fall of the drive signal Vi, so the relay 20 closes the switch. Immediately turn off the means 5. When the drive signal Vi changes to the "L" level in this way, the solenoid 2 is energized.
1 pressure is no longer applied at all. At this time,
Since the current I of the solenoid 2 falls exponentially, the plunger 2a returns to the original position PO after a short time delay and becomes inactive.

After this period, the solenoid 2 is again set to the ready state. In other words, the drive signal VL changes from the 'H' level to the 'L' level.
When it falls to the level, two one-shot multi-by-breaks 17.1B will put the flip-flop 19 in the cent state after a time delay, so at that set point,
The switch means 5 is turned on again, and the solenoid 2
A preparatory voltage Vp is applied to the terminal, and as a result, a preparatory current Ip is caused to flow in advance in preparation for the next operation.

Modified Example of the Invention In the above embodiment, the driving means for the switch means 3.4.5 is performed by the relay 14.15.20, but these on/off driving means are constructed using semiconductor switching elements or the like. You can also do that. Furthermore, in the above embodiment, the inside of the control circuit 16 is configured with two one-shot multipipe rakes 17 and 18 and a flip-flop 19, but this part may be replaced with a time delay circuit, a sequential circuit, etc. It can also be constructed from combined logic circuits.

Furthermore, in the above embodiment, the preparation voltage Vp is applied to the solenoid 2 at the time when the delay time ΔT has elapsed after the fall of the drive signal Vi. It is only necessary to precede the generation of the drive signal Vi. Therefore, the setting of the flip-flop 19 can also be performed using another signal that precedes the drive signal Vi at the 11H'' level. At this time, it is advantageous if the set time point is immediately before the start of operation because power consumption is reduced.

Effect of the invention The present invention provides the following effects.

First of all, when the solenoid is in the ready state, the preparation voltage is applied in advance and the preparation current is flowing.
When a drive signal of "H" level is applied, the delay time from the time when the drive signal is generated until the solenoid starts operating can be shortened, and the response speed of the solenoid is therefore faster. The time from the start to the movement to the predetermined position is the same as in the conventional simple overexcitation voltage application method.

Second, because of the low standby voltage, there is no temperature rise in the solenoid when it is inactive, thus preventing abnormal temperature rises even when the solenoid is used continuously for long periods of time.

Thirdly, in the initial operation, the start point of movement during plunging is earlier, and correspondingly, the point of completion of movement is also faster (compared to conventional ones), so the application time of overexcitation voltage is shortened on the time axis. This also reduces the voltage burden.As a result, when driving multiple solenoids with the same overexcitation power source, it becomes possible to drive more solenoids than before.

Finally, fourthly, even when a current monitoring type abnormality device is attached to this type of solenoid, the preparation current continues to flow at a constant value, so there is no change in the abnormality device side. , it can be used as before.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of the solenoid drive device of the present invention, and FIG. 2 is a time chart during operation. 1. Solenoid drive device, 2. Solenoid, 3.4
．． 5...Switch means, 6.7.8...Power terminal, 13
...Time limit circuit, 14.15.20...Relay, 16...
Control circuit, 17.18...One-shot multi-by-break, 19...Flip-flop.

Claims (2)

[Claims] (1) When the solenoid is in the ready state, a certain preparatory voltage is applied to the solenoid, a certain preparatory current is passed through the solenoid, and during initial operation, an overexcitation voltage that is sufficiently higher than the holding voltage is applied to the solenoid. After the initial operation is completed, only the holding voltage is applied, and when the operation is completed and the voltage is not in operation, the holding voltage is cut off to create a no-voltage state, and then the preparation state is reached.
A method for driving a solenoid, characterized in that the preparation voltage described above is applied. (2) A solenoid that can be selectively connected to the holding voltage, overexcitation voltage, and preparation voltage input terminals by a switch means, and a solenoid that receives a drive signal and connects to the overexcitation voltage input terminal for a certain period of time during the initial operation of the solenoid. A time limit circuit that sets a switching means between the solenoid and the solenoid to an on state, and a time-limited circuit that receives the above drive signal as an input and sets a switching means between a holding voltage input terminal and the solenoid to an on state for the duration of the drive signal. and a control that takes the drive signal as an input and sets a switch means between the solenoid and the input terminal of the preparation voltage in an on state for a preparation period other than a certain time from the time when the drive signal disappears. A solenoid drive device comprising a circuit.