JPS6362981A - Rotary solenoid type actuator - Google Patents

Abstract

PURPOSE:To perform a flow control in a range from low temperature to high temperature by a single actuator, by providing solenoid coils to be arranged in a position, opposed to a magnet provided in a driving shaft, while stopping a spring made of bimetal to said magnet. CONSTITUTION:An actuator provides a magnet 5 to be arranged in a driving shaft 8, to which a valve unit 7 is fixed, and solenoid coils 20, 30 to be arranged in a position opposed to said magnet 5. While the actuator stops one end of a bimetal made spring 11 to said magnet 5 and the other end of this bimetal made spring 11 to an inner housing 10. In this way, the valve unit 7 can be driven rotating by excitation force of the solenoid coils 20, 30, while the intensity of the rotary driving is variably controlled in accordance with temperature by resisting force of the bimetal made spring 11. The bimetal made spring 11 enables the driving shaft 8 to be returned to the neutral position.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a rotary solenoid actuator,
This is to variably control the flow rate of fluid passing through. The actuator of the present invention is effective for controlling the intake air amount of an automobile, for example.

[Prior art and problems]

It has long been known to control the amount of intake air in automobiles using electromagnetic actuators (Japanese Patent Laid-Open No. 57-73839).
Publication No.).

With conventional actuators, control in low temperature ranges is
Air flow control valves made of bimetal or thermowax were used to control air flow, and electromagnetic actuators were used to control air flow in high temperature ranges. This is to ensure the safety of intake air flow rate control.
This is because if a single electromagnetic actuator is used to perform wide control from a low temperature range to a high temperature range, the actuator cannot be accurately controlled when a temperature sensor or the like fails.

[Problem to be solved by the invention]

An object of the present invention is to control fluid flow rate over a wide range from a low temperature range to a high temperature range using one solenoid actuator.

Further, the actuator of the present invention aims to provide an actuator that can maintain smooth operation even if a failure occurs in a movable part such as an electromagnetic coil or a vitamel.

[Configuration and operation]

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

According to the present invention, the rotation of the drive shaft is controlled by the excitation force of the electromagnetic coil, and the valve body is displaced in accordance with the rotation of the drive shaft, thereby controlling the fluid flow rate. Furthermore, in the actuator of the present invention, the bimetallic spring acts as a resistance in the rotational direction of the drive shaft. Therefore, in the actuator of the present invention, the valve body can be rotationally driven by a constant excitation force, and the magnitude of the rotational drive can be varied depending on the temperature by the resistance force of the bimetallic spring.

Further, the actuator of the present invention is basically configured to return the drive shaft to the neutral position by means of a bimetallic spring. Furthermore, the actuator of the present invention is configured such that the drive shaft is returned to the neutral position by the magnetic force of the magnet fixed to the drive shaft. Therefore, in the actuator of the present invention, even if some malfunction 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 based on the drawings.

In FIG. 1, reference numeral 1 denotes a housing made of aluminum or resin material, and the housing 1 has an intake pipe port 14 communicating with an air filter 21 of an automobile and an intake pipe outlet 13 communicating with an engine 25. When the housing 1 is made of resin material, it is preferably made of polybutylene selectate (PDT) or nylon.

Furthermore, bearings 6 and 9 are fixed within the housing 1.
A drive shaft 8 is rotatably supported via the bearings 6 and 9. A throttle valve 7 is fixed to the drive shaft 8, and the rotational position of the throttle valve 7 is variably controlled in accordance with the rotation of the drive shaft 8. As shown in FIG. 5, the throttle valve 7 has a suction pipe population of 14. The area of the flow passage between the outlets 13 is variably controlled.

An engine cooling water passage chamber 12 is also formed in the housing 1, and this passage chamber communicates with an engine cooling water outlet hole 16 and an engine cooling water four hole 15. Therefore, the engine cooling water passes 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 also formed in the inner housing 10 at a position facing the drive shaft 8.

Reference numeral 11 denotes a bimetallic coil spring, one end of which engages 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 this bimetallic spring, the rotation of the drive shaft 80 is subjected to a resistance force in a direction that is restricted.

A cylindrical magnet 5 is also press-fitted into the drive shaft 8. The magnet 5 is rotatably disposed within 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. This detent groove is configured so that the magnetic flux density around the magnet 5 is non-uniform. A sub-core 18 is formed on the side of the main core 4. This sub-core 18 is also made of a magnetic material, and is formed in a direction perpendicular to the detent groove 17. This subcore 1
Reference numeral 8 is provided so that the magnet 5 is rotationally displaced linearly in response to the magnetic force from the electromagnetic coils 20 and 30. The first coil 20 and the second coil 30 are each wound on the main core 4, and the first coil 20 and the second coil 30 are arranged at symmetrical positions with the sub-core 18 in between. 3 is the yoke, main core 4. It is formed to cover the sub-core 18 and the electromagnetic coil 20.30.

This yoke is also made of magnetic material.

The first coil and the second coil are excited according to the voltage applied to the first coil and the second coil 20.30, and the magnet 5 is rotated by the excitation force. This state is shown in Figures 6 to 9.
This will be explained based on the diagram. Figure 6 shows the first and second coils.
Both coils are in a non-energized state, and in this state, the detent groove 17 causes non-uniform sustaining loops, and as a result, the magnet 5 is stopped at a position where the magnetic pole faces the sub-core 18, as shown in FIG. .

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 the arrow in the figure is generated in the main core 4 and the yoke 3. Here, since the main core 4 has a smaller cross-sectional area around the detent groove 17, the magnetic flux is saturated there. As a result, magnetic flux flows from the main core 4 to the magnet 5 side. Therefore, the magnet 5 will rotate as shown in FIG.

FIG. 8 shows a state in which the second coil 30 is excited.

In this state, the magnetic flux flows in the opposite direction to the state shown in FIG. 7 described above, and as a result, the magnet 5 also rotates in the direction opposite to the state 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. Further, FIGS. 14 to 17 show the relationship between duty ratio and current characteristics, and FIGS. 18 to 21 show the relationship between duty ratio and flow rate. Each figure shows the non-energized state in FIG. 6, the energized state of the first coil 20 in FIG.
This corresponds to the state in which 30 second coils are connected in FIG. 8 and the state in which both coils are 20° and 30 times energized in FIG. 9. As shown in FIG. 17, the duty ratio characteristic is a control of 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, both coils 20
．． By controlling the time of energization to 30, the properties of the synthesis are obtained.

This duty ratio control is the first step. 2nd coil 20.30
It is controlled by a computer 22 which outputs electrical signals to. Note that the computer 22 outputs an optimal duty ratio based on signals from various sensors 23 that detect the engine speed and the like.

If only the electromagnetic coils 20.30 were used, the characteristics would be as shown by the broken line in FIG. 21, but in the actuator of this example, a bimetallic spring 11 is used in addition to the electromagnetic coils 20.30.

This spring 11 also provides a resistance force to the drive shaft 8 in the rotational direction. 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 coil 20.30 and the resistance force of the bimetallic spring 11.

Moreover, the spring force of the bimetal spring 11 changes depending on the environmental temperature in which the bimetal is installed. That is, in this example, as the environmental temperature of the bimetallic spring 11 becomes lower, the tightening force of the bimetallic spring 11 becomes smaller, and conversely, as the environmental temperature of the bimetallic spring becomes higher, the tightening force of the spring 11 decreases. is configured so that it becomes large. Therefore, when the environmental temperature is low, for example around -30°C, as shown by the solid line A in Figure 2, even if the duty ratio control of the electromagnetic coil remains the same, the rotation angle increases, resulting in a large amount of Inhaled air enters the intake tube 14. It will flow between the exits 13.

If the environmental temperature becomes high, for example, about 30° C., the characteristics will become as shown by the solid line in FIG. 2. Furthermore, if the environmental temperature C becomes higher, for example, about 90 degrees Celsius, the characteristics shown by the solid line C in FIG. The flow rate of intake air flowing through is small.

Note that FIG. 3◆ is an explanatory diagram showing the 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 m5ec.

As explained above, according to the actuator of this example, the rotation of the drive shaft 8 is controlled by both the duty ratio control of the current 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 over a wide range from low temperature to high temperature.

Here, suppose that either the first coil 20 or the second coil 30 breaks down for some reason.

In that case, an imbalance occurs in the rotational torque applied to the drive shaft 8, and the drive shaft temporarily tries to rotate largely. However, in the actuator of this example, even in such a case, the bimetallic spring 11 works in the direction of regulating the rotation of the drive shaft, so the throttle valve 7 instantly becomes thicker (does not fluctuate). , it does not place a large emphasis on engine operation.

If one of the coils 20, 30 fails, this will result in some displacement of the throttle valve 7. However, in this case, even if the throttle valve is slightly displaced, this will result in a change in the rotational speed of the engine 25, and since the engine rotational speed is detected by the sensor 23, the computer 22 will provide feedback. The optimum duty ratio control signal for that state is output to the coil that can be obtained without failure.

1 deviates from the predetermined value, and a force in the rotational direction is applied to the drive shaft 8. However, the bimetallic spring does not become unbalanced suddenly.

As a result, the throttle valve 7 tries to change gradually, but even in this case, the change in the throttle valve is due to the engine 25.
Since the rotation speed change of the engine 25 is fed back to the computer 22 via the sensor 23, a signal is sent to the first coil and the second coil 20.30 to ensure the spring force of the bimetallic spring. It will be output. As a result, in the actuator of this example, even if the bimetallic spring causes an unbalanced load, this does not increase (deteriorate) the operating characteristics of the engine.

〔Effect of the invention〕

As explained above, according to the actuator of the present invention, a single actuator can control the flow rate over a wide range from a low temperature range to a high temperature range. Moreover, since the actuator of the present invention is always guaranteed to be on the safe side, it has the effect of extremely high reliability.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the actuator of the present invention, FIG. 2 is an explanatory diagram showing the characteristics of the electromagnetic coil shown in FIG. 1 and the bimetallic spring, and FIG. 4 is a sectional view taken along ■-■ in FIG. 1, FIG. 5 is a sectional view taken along ■-■ in FIG. 1, and FIGS. 6 to 9 are sectional views taken along An explanatory diagram showing the rotating state of the illustrated magnet, FIGS. 10 to 13 are explanatory diagrams showing the relationship between the duty ratio and torque characteristics of the illustrated electromagnetic coil, and FIGS. 14 to 17 are respectively illustrated in FIG. 1. 18 to 21 are explanatory diagrams showing the relationship between the duty ratio and current characteristics of the electromagnetic coil shown in FIG. 1, respectively. FIGS. 1...Housing, 3...Yoke, 4...Main core. 5... Magnet, 7... Valve body, 8... Drive shaft, 11...
...Bimetallic spring.

Claims (1)

[Claims] A housing having a fluid inflow hole and a fluid outflow hole, a drive shaft rotatably disposed in the housing, and a communication passage area between the fluid inflow hole and the fluid outflow hole that is fixed to the drive shaft and responds to rotation of the drive shaft. a valve body that variably controls the drive shaft, a magnet fixed to the drive shaft, an electromagnetic coil placed opposite to the magnet, and a bimetallic structure whose one end is locked to the housing and the other end is locked to the drive shaft. a spring, the rotation of the drive shaft is controlled by the magnetic force between the electromagnetic coil and the magnet, and a predetermined resistance force is generated in the rotational direction of the drive shaft by the spring force of the bimetallic spring. Further, the rotary solenoid actuator is configured such that the rotational direction resistance of the bimetallic spring is varied depending on the temperature.