JPH0122517B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric flow rate control valve device that opens and closes a slide valve using an electromagnetically acting linear motor to proportionally control the flow rate of fluid communication.

Generally, this type of electric flow control valve device includes a hollow iron core, a bobbin slidably disposed on the iron core, and a magnetic flux perpendicular to the winding of an electromagnetic coil wound on the bobbin. A moving coil type linear motor is constituted by permanent magnets arranged so as to pass through the permanent magnets, and a magnetic yoke or a magnetic body forming a magnetic circuit of the permanent magnets together with the iron core. It includes a slide valve that slides on a communication hole formed on a hollow core to control the opening area of the hole, and a spring that biases the slide valve in a direction to fully close the communication hole.

Such an electric flow control valve device is disposed in an intake passage with a throttle valve biased in order to control the idling rotation of the engine.

However, since high-temperature, high-humidity air flows through such electric flow control valve devices, if the ambient temperature drops to -20 to 30 degrees Celsius, the slide valve will not be able to absorb the biasing force of the spring when the engine is stopped. Ice sometimes formed on the sliding surface of the slide valve when it was held in the fully closed position. If ice forms on the sliding surface of the slide valve, even if you try to start the engine by operating the ignition key switch again, the slide valve is fully closed, making it difficult to start the engine as the specified intake air cannot be achieved. There is a drawback.

Therefore, in order to eliminate the above-mentioned drawbacks, the present invention, after stopping the engine by operating the ignition key switch, passes an electric current in the direction of opening the communication hole in the coil to bring the slide valve to the fully open position, and magnetically moves the slide valve. An object of the present invention is to provide an electric flow rate control valve device which can prevent a slide valve from being stuck in a fully closed position due to freezing with a simple configuration by holding the position without adsorption to the slide valve.

An embodiment of the present invention will be described below with reference to the accompanying drawings. In the electric flow control valve device 10 shown in FIG. 1, an inlet port 11 and an outlet port 1 form an intake passage that biases the intake system of a throttle valve (not shown).
A cover 14 is integrally and airtightly connected to the right end of the body 13 having a cover 13 in the drawing. On the shaft inside the body 13 is a hollow iron core 16 made of a magnetic material.
A bobbin 17 made of a non-magnetic material is slidably disposed on the iron core 16. An electromagnetic coil 18 is wound around the bobbin 17, and a pair of permanent magnets 19 and 20 are arranged so that magnetic flux passes perpendicularly to the winding direction of the electromagnetic coil 18. The body 13 functions as a magnetic yoke that forms a magnetic circuit for the magnetic flux generated by the permanent magnets 19 and 20 together with the iron core 16, thereby configuring a moving coil type linear motor.

Although this embodiment shows only an example in which the body 13 is used as a magnetic yoke for forming a magnetic circuit, the magnetic yoke may be provided as a separate member from the body 13.

On the hollow core 16, there is a hollow part 16a inside the core 16.
A plurality of elongated communication holes 22 are formed to communicate between the cylinder and the external space 16b, and a slide valve 23 fixed to the bobbin can slide through the opening of the continuous bullet hole 22. Here, the hollow portion 16a of the iron core 16 communicates with the outlet port 12 via the illustrated left and right open ends 16c of the iron core 16 and the passage 13a formed in the body 13, while the outer space 16b communicates with the inlet port 11. In addition, inlet port 11 communicates with an atmospheric source (not shown) and outlet port 12 communicates with a negative pressure source (not shown). Therefore, in response to the current value applied to the electromagnetic coil 18, the slide valve 23 integrated with the bobbin 17 is actuated and displaced to control the opening area of the communication hole 22. As a result, both ports 1
The communication between 1 and 12, that is, the flow rate of atmospheric air flowing into the negative pressure source is controlled proportionally. Note that the slide valve is not specially provided, and the bobbin itself may have a valve function. Both ends of the electromagnetic coil 18 have eyelets 24 attached to the bobbin 17, respectively.
It is electrically connected to 25. Also eyelets 24, 25
Movable terminals 26 and 27 are electrically connected to both ends of the electromagnetic coil 18 at the bobbin 1.
7 so that the inner peripheral surfaces of the fixed terminals 28 and 29 are slidably displaced in the axial direction integrally with the bobbin 17. The fixed terminals 28 and 29 are electrically connected to lead wires 31 and 32, respectively, which apply the output of the valve drive circuit 30 to the electromagnetic coil 18. Therefore, the output of the valve drive circuit 30 is connected to the lead wire 31.
From fixed terminal 28, movable terminal 26,
Eyelet 24, coil 18, eyelet 25, movable terminal 27, fixed terminal 29, lead wire 32
In addition, from the lead wire 32 to the fixed terminal 29, the movable terminal 27, and the eyelet 2
5. Whether the current flows in the negative direction through the electromagnetic coil 18, eyelet 24, movable terminal 26, fixed terminal 28, and lead wire 31 is determined by the current direction of the output of the valve drive circuit 30, and the former current direction In this case, the bobbin 17 is displaced to the right in the figure according to Fleming's left-hand rule, and in the latter current direction, it is displaced to the left in the figure.

Holding magnets 38 and 39 made of permanent magnets are attached to the right end of the bobbin 17.
Cushioning materials 40 and 41 made of a non-magnetic material such as rubber and having cushioning properties are attached to the right side surfaces of the hollow cores 8 and 39, respectively, and permanent retaining materials 40 and 41 are attached to the right side of the hollow core 16 fixed to the body 13, respectively. Holding magnets 42 and 4 made of permanent magnets capable of magnetic attraction through magnets 38 and 39 and buffer materials 40 and 41
3 is installed and the slide valve 23 reaches the fully open position, its position is maintained by the holding magnet 38,
39 and the holding magnets 42, 43.

Next, the output control of the valve drive circuit 30 will be explained with reference to the block diagram shown in FIG. positive duty control is performed, and the duty output is applied to the valve drive circuit 30. Further, the DC voltage outputted from the battery 36 and having a level positive with respect to the ground voltage is converted by the DC-DC converter 37 into a DC voltage having a level positive and negative with respect to the ground voltage. The DC voltage converted by the DC-DC converter 37 is applied to the valve drive circuit 30. A negative voltage is output from the valve drive circuit 30 when the oscillation output level of the duty control section 34 is zero, and a positive voltage is output when the oscillation output level of the duty control section 34 is positive. When the output voltage of the valve drive circuit 30 is positive, a current flows in the electromagnetic coil 18 in the positive direction, and when the voltage is negative, the current flows in the electromagnetic coil 18 in the negative direction, and the valve opening of the slide valve 23 changes as the valve opens. Drive circuit 30
It responds to the duty ratio of positive voltage in one period of .

When the ignition key switch (not shown) is turned from on to off, the detection circuit 44 detects the state and switches the output applied to the valve drive circuit 30 from zero voltage to positive voltage for a predetermined period of time. , a current is passed through the electromagnetic coil 18 in the positive direction to bring the slide valve 23 to the fully open position.

Next, the output of the valve drive circuit 30 will be explained with reference to FIG. First, when the ignition key switch is in the on state, the output of the detection circuit 44 is held at zero voltage. When a constant negative DC voltage, which is the output of the valve drive circuit 30, is applied to the electromagnetic coil 18, the slide valve 23 attached to the bobbin 17 is displaced to the left, and the bobbin 17 is disposed on the iron core 16 as shown in the first diagram. The slide valve 23 is held at a position in contact with a stopper (not shown) of the core 45, and the valve opening degree of the slide valve 23 is in a fully closed state. Next, in order to control the valve opening to 75%, the output of the valve drive circuit 30 first skips to a duty ratio of 50%, and then increases to 75%.
The electromagnetic coil 18 is excited to maintain the valve opening of 75% at a duty ratio of 50% of the output of the drive circuit 30. Next, the control to close the valve from 75% to 25% is to excite the electromagnetic coil at a duty ratio of 25% to change the valve opening.
25%, and then maintain the valve opening at 25% with a duty ratio of 50%.

Next, in order to fully close the valve opening from the 25% valve opening, a 0% duty ratio, that is, a constant negative DC voltage is applied to the electromagnetic coil 18, and the slide valve 23 is fully closed as shown in the first figure. held closed.
Note that when changing the valve opening from a fully closed or fully open state where a constant DC voltage is applied to the electromagnetic coil 18 from the valve drive circuit 30, the output of the valve drive circuit 30 skips to a duty ratio of 50%. Then, the duty ratio changes according to the set valve opening degree. After the slide valve 23 is displaced to a position corresponding to the valve opening at a duty ratio corresponding to the set valve opening, the electromagnetic coil 18 is excited at a duty ratio corresponding to the valve opening. Continue and slide valve 23
is further determined by the duty ratio (50%
If the duty ratio is above, the displacement will be in the opening direction, or if it is less than 50%, the displacement will be in the closing direction. Therefore, the duty ratio according to the set valve opening degree is
After the output is output from the valve, the valve opening degree is maintained at a duty ratio of 50%.

When the ignition key switch is turned off, the duty control section 34, oscillator 35, and converter 37 are deactivated, and a positive voltage is applied from the detection circuit 44 to the valve drive circuit 30 for a predetermined time only. A current is passed in the positive direction, and the slide valve 23 is displaced to the fully open position.
Its position is held by the attraction action of the holding magnets 38, 39, 42, and 43, and even if the positive voltage from the detection circuit 44 disappears, the slide valve 23 remains in the fully open position when the ignition key switch is off. be done. Therefore, since the slide valve 23 is in the fully open position, even if the sliding surface of the slide valve 23 is permanently connected, the intake passage of the slide valve 23 is open, so the ignition key switch must be turned on. The engine can be started.
If the engine can be started, the ice on the slide valve 23 can be removed by the engine heat, and the slide valve 23 can also perform predetermined flow rate control by duty control.

As explained above, according to the present invention, after the ignition key switch is turned off, the slide valve is forcibly displaced to the fully open position, and this position can be maintained by magnetic attraction. Even if ice forms on the sliding surface of the slide valve when the engine is stopped, the intake air will always be maintained at the specified level, and the engine will start easily when the ignition key switch is operated again. play.

As the magnetic attraction means for holding the slide valve in the fully open position, this function can also be achieved by using a Hikyu magnet on either the slide valve or the body side and using a magnetic material on the other side.

The impact materials 40 and 41 also prevent the holding magnets 38 and 39 from colliding with the holding magnets 42 and 43 when the slide valve 23 is in the fully open position, thereby preventing abnormal noise from being generated. Even when the slide valve 23 should be displaced in the closing direction, the slide valve 23 is difficult to be displaced in the closing direction, and in order to prevent this, the cushioning material 40 is
The holding magnets are provided to prevent direct attraction of the holding magnets and to facilitate the movement of the slide valve 23 in the closing direction when the slide valve 23 needs to be moved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the device of the present invention, FIG. 2 is a block diagram showing the driving method of the device of the present invention, and FIG. 3 is a characteristic diagram showing the valve drive output. 10: Electric flow control valve device, 11: Inlet port, 12: Outlet port, 1
3: Body (magnetic yoke), 16: Hollow iron core,
17: Bobbin, 18: Electromagnetic coil, 19, 20:
Permanent magnet, 38, 39, 42, 43: holding magnet,
22: Communication hole, 23: Slide valve.

Claims (1)

[Claims] 1 A body with an inlet port and an outlet port, a hollow core disposed on a shaft within the body, a bobbin slidably disposed on the outer periphery of the core, and an electromagnetic coil wound on the bobbin. permanent magnets arranged so that magnetic flux passes at right angles to the windings of the coil; a magnetic yoke that forms a magnetic circuit for the magnetic flux generated by the permanent magnets together with the iron core; an electric flow rate control valve device having a slide valve portion that slides on a communication hole formed on the hollow core in response to the operational displacement of the bobbin driven by the ratio, and controls the opening area of the hole. After the ignition key switch is turned off, a detection circuit passes current through the coil in the direction of opening the communication hole to bring the slide valve part to the fully open position, and a detection circuit connects the slide valve part side to the body. An electric flow rate control valve device comprising a holding magnet that holds the position by magnetically adhering to the side.