JPH0333950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic drive device that controls an electric actuator using two coils with two pulses.

Conventional electric actuators are made up of a single coil, a spring, and a moving core, so they require enough power to overcome the spring force, requiring a relatively high minimum operating voltage, and due to temperature changes, the coil The resistance also changes, making linear control in response to commands impossible unless an external compensation circuit is provided.

The present invention eliminates the above-mentioned drawbacks and uses two coils and two pulses, so even if the voltage and coil resistance change, the product balances itself.
The purpose of the present invention is to provide an electromagnetic drive device that enables linear control without providing an external compensation circuit, and has quick response because no spring is required.

An embodiment of the device of the present invention will be described below.

The two-pulse control electromagnetic actuator shown in FIG. 1 includes a valve body control drive unit 10 configured as a solenoid valve,
A flow control valve section 20 combined therewith is provided. In the valve body control drive unit 10, two electromagnetic coils 13A and 13B, a first and a second electromagnetic coil, are built into the inside of a cylindrical yoke 11 on both sides with a donut plate-shaped yoke plate 12 in between. has been done. Both of the two electromagnetic coils have a cylindrical shape, and a cylindrical sleeve 14 is fixed to the inner periphery of the two electromagnetic coils.

At one end of the yoke 11 (on the right side in the figure) is a disc-shaped
A substantially conical first fixed core 16A is fixed at the center thereof. Further, at the other end of the yoke 11, there is a substantially conical second fixed core 16 having a yoke integrally formed therein.
B is fixed.

Both fixed cores 16A and 16B protrude inside the sleeve 14. A movable core 17 is slidably disposed inside the sleeve 14 between the fixed cores 16A and 16B. At both ends of this movable iron core 17, suction surfaces 171A and 171A are formed by conical depressions corresponding to both fixed iron cores 16A and 16B, respectively.
71B is formed.

The output shaft 18 passes through the movable iron core 16A, protrudes into the flow rate control section 20, and is slidably supported by a bearing 19.

In the drive unit 10 having the above configuration, when the first electromagnetic coil 13A is energized, an attractive force is generated on the first attraction surface 171A of the movable iron core, and the movable iron core 17, that is, the output shaft 18 is driven rightward in the figure. Conversely, when the second electromagnetic coil 13B is energized, the second attraction surface 17
A suction force is generated at 1B, and the output shaft 18 is driven to the left in the figure.

The flow rate control valve section 20 for the drive section 10 is as follows:
The housing 21 is brought into close contact with the fixed iron core 16A and fixed to the drive unit 10 with screws or the like (not shown). An inlet port 23 and an outlet port 24 are formed in the housing 21.
A valve seat 27 is provided on the outlet port 24 side.
The output shaft 18 of the drive unit 10 has a fixed iron core 16A.
It extends to the outlet port 24 side via.

A valve body 28 is fixed to the end of the output shaft 18 by a step 181 of the output shaft 18 . The valve body 28 moves together with the output shaft 18 to come into contact with and separate from the valve seat 27, thereby controlling the fluid flow rate from the inlet port 23 to the outlet port 24. Here, when the valve body 28 moves to the left in the figure, it moves away from the valve seat 27 and increases the passage area, that is, increases the fluid flow rate, and conversely, when it moves to the right, it decreases the passage area and the fluid flow rate.

In this way, in the embodiment described above, current is passed through both the electromagnetic coils 13A and 13B of the drive unit 10, and the position of the valve body is controlled by the balance of the electromagnetic forces generated in both.

FIG. 2 shows a drive circuit 30 for driving a two-pulse controlled electromagnetic actuator. operational amplifier
A ramp waveform R is obtained at point a using A ₁ , capacitor C ₁ , and resistor R ₂ R ₃ R ₄ R ₅ R ₆ . The waveform characteristics of this ramp waveform R are shown in Figure 3a, and the shape of the waveform R is as follows:
It is determined by the resistance of R ₂ R ₃ R ₄ , and the frequency of waveform R is
Determined by the resistance of R ₅ R ₆ . Therefore, the voltage comparator _A2 compares this ramp waveform R with the analog command voltage (output voltage of _R1 ) whose voltage is made variable by the variable resistor _R1 .
The voltage to drive is obtained at point b.

This voltage at point B (waveform b ₁ in FIG. 3b) is inverted by a voltage comparator A ₃ to obtain the voltage at point C which drives the coil 13A. The voltage signals at points b and c are shown in Figure 3b, and the upper waveform b ₁ in the figure is b
Point signal, lower waveform C ₁ is point C signal, etc.
The voltage signals at point b and point c have completely opposite phases. Then, voltages at point b and point c are applied to the bases of the driving transistors Q ₁ and Q ₂ , and the coil 13B or
By driving the coil 13A, it is possible to control the valve body position based on the electromagnetic energy ratio generated in both coils.

In addition, D ₁ in Fig. 2 is a Zener diode, +B
is the positive electrode of the battery, and G ₁ D and G ₂ D are diodes.

In this case, the waveform is as shown in Figure 3b.
b ₁ has a smaller duty ratio than waveform C ₁ ,
Transistor Q ₁ is more ON than transistor Q ₂
The electromagnetic force generated in the coil 13 is larger than the electromagnetic force generated in the coil 13B. In addition, in Fig. 3b
ON and OFF indicate the ON and OFF states of transistors Q ₁ and Q ₂ for each waveform.

The two-pulse controlled electric actuator of FIG. 1 is used, for example, to control the intake air flow rate of an engine. In that case, the control valve is installed in a manner that bypasses the throttle valve in the normal intake passage of the engine, and is installed in the inlet port 23.
is connected to the upstream side of the throttle valve, and the outlet port 24 is connected to the downstream side of the throttle valve. As a result, the control valve controls the intake air or (mixture) flow rate that bypasses the throttle valve.

For example, the analog command voltage commanded by the ramp waveform obtained at point a in FIG. 2 (R in FIG. 3 a) and the variable resistor R ₁ in FIG.
When the voltage X indicated by the dashed dotted line is input to the voltage comparator A ₂ in Figure 2, the voltage comparator A ₂ compares both input voltages and obtains the voltage at point b, which is the voltage at point b in Figure 3. The voltage at the other point C is the voltage C ₁ obtained by inverting the voltage b ₁ at point _b using the voltage comparator A ₃ (the one-dot chain line in Figure 3b shows the b 1 signal).
C ₁ signal).

As explained above, by utilizing the fact that the voltage signals at point b and point C are completely opposite in phase, the voltage at point b is applied to the driving transistor _Q1 , and the output current of this transistor _Q1 is applied to the coil 13B. ,In other words,
The second electromagnetic coil 13B shown in FIG.
Due to the suction force generated at 1B, the gap at _G2 tends to become smaller. In other words, the valve body 28 tends to move to the left and the fluid passage area tends to increase, so the flow rate tends to increase.

The other C point voltage is the driving transistor Q ₂
is applied to the coil 13A, that is, the first voltage in FIG.
The electromagnetic coil 13A is energized, and due to the attraction force generated on the first attraction surface 171A of the movable iron core 17 due to this energized current, the gap of _G1 tends to become smaller, so the valve body 28 tends to move to the right. year,
In order to reduce the fluid passage area, the flow rate tends to decrease. As shown in FIG. 3b, the point B signal _b1 is transmitted to the electromagnetic coil 13B, and the point C signal _C1 is transmitted to the electromagnetic coil 13B.
Communicate to A. Since these are repeated, the stronger of the electromagnetic forces generated by the electromagnetic coils 13A and 13B, that is, in this case, the electromagnetic coil 1
Since 3A is strong, the valve body 28 moves to the right and almost closes.

If the analog command voltage applied from the variable resistor R ₁ is like the solid line Y in Figure 3a, the characteristics of the voltage at point b and point C will be the solid lines b ₂ and c ₂ in Figure 3c. , the duty ratio of the two pulses is equal, so G ₁ of the control valve, which is the control electric actuator.
The gaps of G2 and _G2 are almost equal, and the gap between valve body 2
8 is in the state shown in FIG. 1, that is, stopped at the neutral position.

Also, if the analog voltage commanded by variable resistor _R1 becomes like the dotted line Z in Figure 3a, then point b C
The characteristics of the point voltage are the dotted lines b ₃ and C ₃ in FIG _. The gap becomes smaller, the valve body 28 moves to the left, the fluid passage increases, and the fluid flow rate approaches full open.

Therefore, by varying the command voltage output from the variable resistor _R1 , the position of the valve body 28 to be operated can be freely selected according to the input energy ratio of the two electromagnetic coils.

In addition, when applying to automobiles, variable resistor R ₁
Use an electronic control unit instead. The flow rate of the intake air or mixture that bypasses the throttle valve of the engine can be controlled by the analog command voltage of the electronic control unit. In this way, the above embodiment does not require a spring or the like, there is no waste of energy, and the response is quick. Furthermore, since the input energy between the two coils 13A and 13B is distributed, even if the resistance of each part (for example, coil resistance) increases due to temperature, it is canceled out between each coil 13A and 13B, so there is almost no change in characteristics. do not have.

Although the coils 13A and 13B are wound separately in the above embodiment, they may be wound twice.
In the case of double winding, there is an advantage that there is less difference in heat generation between the coils.

As described above, in the present invention, the output shaft is driven by the unbalance of the electromagnetic force generated by the first and second electromagnetic coils. Compared to those that control the amount, it has the following effects.

(1) No spring is required.

(2) Even if the power supply voltage fluctuates or the coil resistance etc. fluctuates due to fluctuations in the ambient temperature, this fluctuation acts on both electromagnetic coils, so the fluctuations are canceled out and commands can be maintained without the need for an external compensation circuit. A control amount that is faithful to the signal can be obtained.

(3) Since there is no spring, there is no need to move the output shaft against spring force, resulting in faster response.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an electromagnetic flow control valve showing an embodiment of the device of the present invention, Fig. 2 is a drive circuit diagram for driving the control valve, and Figs. FIG. 3 is a voltage waveform diagram of each part of the circuit. 18... Output shaft, 13A... First electromagnetic coil,
13B... Second electromagnetic coil, 10, 20... Electromagnetic actuator, 30... Drive circuit, 28... Valve body, 27... Valve seat.

Claims (1)

[Scope of Claims] 1. A first fixed core made of a magnetic material; a second fixed core made of a magnetic material and disposed in a position facing the first fixed core; and a second fixed core made of a magnetic material wound around the first fixed core. a rotated first electromagnetic coil; a second electromagnetic coil wound around the outer periphery of the second fixed iron core; a second electromagnetic coil arranged to be movable between the first fixed iron core and the second fixed iron core; A movable core has a suction surface that is attracted to each of the first fixed core and the second fixed core, a driven part that is driven by the movement of the movable core, and a pulse voltage is applied to the first electromagnetic coil. to generate a magnetic force that attracts the movable iron core to the first fixed iron core side, and applies a pulse voltage having a phase opposite to the pulse voltage to the second electromagnetic coil to attract the movable iron core to the second fixed iron core side. a drive circuit that generates a magnetic force that attracts the movable core to the first fixed core; drive circuit.