JPH0799212B2 - Rotary Solenoid Actuator - Google Patents

Description

The present invention relates to a rotary solenoid type actuator,
The flow rate of the fluid is variably controlled. The actuator of the present invention is effective when used for controlling the intake air amount of a vehicle, for example.

[Prior art and problems]

Conventionally, it has been known to control the intake air amount of an automobile by an electromagnetic actuator (Japanese Patent Laid-Open No. 57-73839).

With conventional actuators, control in the low temperature range is
The air flow rate control valve is mainly made of bimetal or thermowax, and the electromagnetic actuator is used for controlling the air flow rate in a high temperature range. This is to ensure the safety of the intake air flow rate control,
This is because if one electromagnetic actuator is widely controlled in a low temperature range to a high temperature range, the actuator cannot be accurately controlled when the temperature sensor or the like fails.

[Problems to be Solved by the Invention]

An object of the present invention is to control the fluid flow rate widely from a low temperature region to a high temperature region with one solenoid type actuator.

It is another object of the actuator of the present invention to be an actuator that can be connected to operate smoothly even if a movable part such as an electromagnetic coil or a vitamel fails.

[Configuration and operation]

In order to achieve the above object, in the present invention, a magnet is arranged on a drive shaft to which a valve body is fixed, and an electromagnetic coil is arranged at a position facing the magnet. Further, one end of a bimetal spring is locked to the magnet, and the other end of the bimetal spring is locked to the housing.

According to the present invention, the rotation of the drive shaft is controlled by the exciting force of the electromagnetic coil, the valve body is displaced according to the rotation of the drive shaft, and thereby the fluid flow rate is controlled. Further, in the actuator of the present invention, the vitamel spring acts as a resistance in the rotation direction of the drive shaft. Therefore,
In the actuator of the present invention, the valve element can be rotationally driven by a constant exciting force, and the magnitude of the rotational driving can be changed according to the temperature by the resistance force of the bimetallic spring.

Further, the actuator of the present invention is basically configured to be returned to the neutral position of the drive shaft by the bimetallic spring. Further, in the actuator of the present invention, the magnetic force of the magnet fixed to the drive shaft returns the drive shaft to the neutral position. Therefore, in the actuator of the present invention, even if some trouble occurs on either the electromagnetic coil side or the bimetal side, the drive shaft can be returned to the neutral position, and smooth operation can be maintained.

〔Example〕

An embodiment of the actuator of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a housing made of aluminum or a resin material, and this housing 1 has an air filter for an automobile.
A suction pipe inlet 14 communicating with 21 and a suction pipe outlet 13 communicating with the engine 25 are open. When the housing 1 is made of resin material, polybutylene terephthalate (PB
T) or nylon is desirable. Bearings 6 and 9 are fixed in the housing 1, and these bearings 6 and 9 are fixed.
The drive shaft 8 is rotatably supported via. The throttle valve 7 is fixed to the drive shaft 8, and the rotational position of the throttle valve 7 is variably controlled according to the rotation of the drive shaft 8. As shown in FIG. 5, the throttle valve 7 variably controls the flow passage area between the suction pipe inlet 14 and the outlet 13.

An engine cooling water passage chamber 12 is also formed in the housing 1, and the passage chamber communicates with an engine cooling water outlet hole 16 and an engine cooling water introducing hole 15. Therefore, the engine cooling water will pass through the passage chamber 12 of this housing.

An inner housing 10 is press-fitted into the housing 1 immediately inside the engine cooling water passage chamber 12, and a boss portion 32 is formed in the inner housing 10 at a position facing the drive shaft 8.

Reference numeral 11 denotes a bimetal coil spring, one end of which is engaged with the boss portion 32 of the inner housing 10. The other end of the bimetallic spring 11 is engaged with the drive shaft 8. Therefore, due to the spring force of the bimetallic spring, the rotation of the drive shaft 8 receives a resistance force in a direction in which the rotation is restricted.

The cylindrical magnet 5 is press-fitted into the drive shaft 8. The magnet 5 is rotatably arranged in the main core as shown in FIG. The main core 4 is made of magnetic material,
A detent groove 17 is formed in a portion facing the magnet 5. The detent groove is configured so that the magnetic flux density around the magnet 5 becomes non-uniform. A sub core 18 is formed on the side of the main core 4. The sub-core 18 is also made of a magnetic material, and the sub-core 18 is formed in the direction perpendicular to the detent groove 17. The sub-core 18 is provided so that the magnet 5 is linearly rotationally displaced according to the magnetic force from the electromagnetic coils 20 and 30. The first coil 20 and the second coil 30 are respectively wound on the main core 4, and the first coil 20 and the second coil 30 are arranged at positions symmetrical with respect to the sub core 18. Reference numeral 3 denotes a yoke, which is formed so as to cover the main core 4, the sub core 18, and the electromagnetic coils 20, 30. This yoke is also made of a magnetic material.

The first coil and the second coil are excited according to the voltage applied to the first coil and the second coil 20 and 30, and the magnet 5 is rotated by the exciting force. This state will be described with reference to FIGS. 6 to 9. FIG. 6 shows a state in which the first coil and the second coil are both non-energized. In this state, the detent groove 17 causes non-uniformity of the continuous loop. As a result, as shown in FIG. It is stopped at a position where it faces each other.

FIG. 7 shows a state in which the first coil is excited. That is, when the first coil 20 is excited, a magnetic flux loop as shown by an arrow in the figure is generated in the main core 4 and the yoke 3. Here, since the main core 4 has a small cross-sectional area around the detent groove 17, the magnetic flux is saturated there.
As a result, the magnetic flux flows from the main core 4 to the magnet 5 side.
Therefore, the magnet 5 is rotated as shown in FIG.

FIG. 8 shows a state in which the second coil 30 is excited. In this state, magnetic flux flows in the opposite direction to the state shown in FIG.
As a result, the magnet 5 also rotates in the direction opposite to that shown in FIG.

Further, FIG. 9 shows a state in which both the first coil 20 and the second coil 30 are excited. Such a state is controlled based on the time ratio of the current applied to the first coil 20 and the second coil 30, that is, the duty ratio.

10 to 13 show characteristics of duty ratio and torque. 14 to 17 show the relationship between the duty ratio and the current characteristic. Furthermore, Figures 18 to 21 show the relationship between duty ratio and flow rate. Each drawing corresponds to the non-energized state of FIG. 6, the first coil 20 energized state of FIG. 7, the second coil 30 energized state of FIG. 8 and both coils 20, 30 energized state of FIG. . As shown in FIG. 17, the duty ratio characteristic controls the time ratio between the time when the first coil 20 is energized and the time when the second coil 30 is energized. Then, as shown in FIG. 21, a composite characteristic can be obtained by controlling the time during which the coils 20 and 30 are energized.

The control of the duty ratio is controlled by the computer 22 which outputs an electric signal to the first and second coils 20 and 30. The computer 22 outputs an optimum duty ratio based on signals from various sensors 23 that detect the engine speed and the like.

If only the electromagnetic coils 20 and 30 are used, the characteristics shown by the broken line in FIG. 21 are obtained. However, in the actuator of this example, in addition to the electromagnetic coils 20 and 30, the bimetallic spring 11 is used.
Is used. This spring 11 also applies a resistance force in the rotational direction to the drive shaft 8. Therefore, the rotation angle of the drive shaft 8 is controlled by the resultant force of the duty ratio control value of the current applied to the electromagnetic coils 20 and 30 and the resistance force of the bimetallic spring 11.

Moreover, the spring force of the bimetallic spring 11 changes according to the environmental temperature in which the bimetal is installed.
That is, in this example, the bimetal spring 11
When the environmental temperature of the bimetal spring 11 is low, the winding force of the bimetallic spring 11 is small. On the contrary, when the environmental temperature of the bimetal spring 11 is high, the winding force of the spring 11 is large. Therefore, when the environmental temperature is low,
For example, at about -30 ° C, as shown by the solid line a in Fig. 2,
Even if the duty ratio control of the electromagnetic coil is the same,
The rotation angle increases, and as a result, a large amount of intake air flows between the intake pipe inlet 14 and the outlet 13.

If the environmental temperature becomes higher, for example, the environmental temperature
At about 30 ° C, the characteristics shown by the solid line B in Fig. 2 are obtained. Further, when the environmental temperature c becomes higher and becomes, for example, about 90 ° C., the characteristic becomes as shown by the solid line c in FIG. 2, and the rotation angle of the valve 7 becomes small despite the above duty ratio control, and as a result, the suction pipe The flow rate of intake air flowing through is small.

Note that FIG. 3 is an explanatory diagram showing a duty ratio control state of the current applied to the first coil and the second coil, and in this example, one cycle is, for example, 4 msec.

As described above, according to the actuator of the present example, the rotation of the drive shaft 8 is controlled by both the duty ratio control of the currents applied to the first coil and the second coil 20, 30 and the bimetallic spring 11. It is possible to control the air flow rate in a wide range from low temperature to high temperature.

Here, it is assumed that either the first coil 20 or the second coil 30 fails for some reason. In that case, the rotational torque applied to the drive shaft 8 is unbalanced, and the drive shaft temporarily tries to rotate largely. However,
In the actuator of this example, even in such a case,
Bimetallic spring in the direction that regulates the rotation of the drive shaft
Since 11 works, the throttle valve 7 does not fluctuate greatly in an instant. As a result, the engine operation is not significantly changed.

If one of the coils 20, 30 fails, as a result, some displacement of the throttle valve 7 will occur. However, in this case, even if some displacement of the throttle valve occurs,
As a result, the number of revolutions of the engine 25 is changed, and the number of revolutions of the engine is detected by the sensor 23, which is fed back in the computer 22,
The optimum duty ratio control signal in that state is output to the coil that is obtained without failure.

Further, when the bimetallic spring 11 is modulated for some reason, the spring force of the spring 11 deviates from a predetermined value and a rotational force is applied to the drive shaft 8. However, the modulation of the bimetallic spring does not occur rapidly. As a result, the throttle valve 7 gradually changes, but even in this case, the change in the throttle valve results in a change in the rotational speed of the engine 25, and the change in the rotational speed of the engine 25 is transmitted via the sensor 23 to the computer 22. Therefore, a signal that guarantees the spring force of the bimetallic spring is output to the first and second coils 20 and 30. As a result, in the actuator of the present example, even if the bimetallic spring may cause modulation, it does not significantly deteriorate the operating characteristics of the engine.

〔The invention's effect〕

As described above, according to the actuator of the present invention, the flow rate can be widely controlled from a low temperature region to a high temperature region by a single actuator. Moreover, since the actuator of the present invention is always guaranteed on the safe side, it has an effect of extremely high reliability.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the actuator of the present invention, FIG. 2 is an explanatory view showing the characteristics of the electromagnetic coil shown in FIG. 1 and a bimetallic spring, and FIG. 3 is applied to the electromagnetic coil shown in FIG. 4 is an explanatory view for explaining a duty ratio control state according to FIG. 4, FIG. 4 is a sectional view taken along line AA of FIG.
FIG. 6 is a sectional view taken along the line BB in FIG. 6, FIG. 6 to FIG. 9 are explanatory views showing the rotating state of the magnet shown in FIG. 1, and FIGS. 10 to 13 are duty ratios and torque characteristics of the electromagnetic coil shown in FIG. 14 to 17 are explanatory views showing the relationship between the duty ratio and current characteristics of the electromagnetic coil shown in FIG. 1, respectively.
FIGS. 21 to 21 are explanatory views showing the relationship between the duty ratio and the flow rate characteristic of the electromagnetic coil shown in FIG. 1 …… Housing, 3 …… Yoke, 4 …… Main core, 5 ……
Magnet, 7 ... Valve element, 8 ... Drive shaft, 11 ... Bimetal spring.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-53-141837 (JP, A) JP-A-59-231280 (JP, A) JP-A-54-147526 (JP, A) JP-A-61- 237842 (JP, A) Actual development Sho 49-85422 (JP, U)

Claims (1)

[Claims] 1. A housing having a fluid inflow hole and a fluid outflow hole, a drive shaft rotatably disposed in the housing, and a fluid inflow hole and an outflow hole fixed to the drive shaft according to the rotation of the drive shaft. A valve body for variably controlling the area of the communication passage between them, a magnet fixed to the drive shaft, an electromagnetic coil arranged to face the magnet, one end locked to the housing and the other end connected to the drive shaft. A bimetal spring that is stopped, and the rotation of the drive shaft is controlled by the magnetic force between the electromagnetic coil and the magnet, and the spring force of the bimetal spring causes the drive shaft to rotate in a predetermined direction. And a rotary solenoid type actuator configured such that the resistance force in the rotation direction of the bimetallic spring is variable according to the temperature.