JP2555571B2 - Rotary Solenoid Actuator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic actuator using an electromagnetic coil, for example, adjusting a bypass air amount before and after a throttle valve of an engine to control an idle speed to a target speed. It is effective when used as an actuator.

[Prior art and problems]

Conventionally, it has been known to use a solenoid actuator as an idle speed control device for an internal combustion engine (for example, Japanese Patent Laid-Open No. 57-73839). However, in general, in the conventional actuator, in order to ensure safety, one actuator has not actually been widely controlled from a low temperature range to a high temperature range. Normally, an air flow control valve using bimetal or thermowax is separately provided in the low temperature region, and this control valve is used as a relatively rough control valve. The solenoid type actuator is used only in the high temperature range.

However, even in such a case, in the conventional rotary solenoid type actuator, when a failure occurs in the solenoid or the like, the control flow rate value largely changes, and particularly when used as an engine idle speed control device. There was a risk that the engine would stop or the engine would run abnormally high.

[Problems to be solved by the invention]

The present invention has been devised in view of the above points, and an object of the present invention is to make it possible to control the flow rate with a single solenoid actuator even in a wide temperature range.
Another object of the solenoid actuator of the present invention is to enable smooth flow control to be continued even if some malfunction occurs in the solenoid or the like.

[Configuration and operation]

To achieve the above object, in the solenoid actuator of the present invention, the magnet is fixed to the drive shaft to which the valve body is fixed. Further, another object of the present invention is to dispose a main core facing the magnet and to provide a detent groove in the main core so that the magnet can obtain a neutral position. Further, three electromagnetic coils, that is, a first electromagnetic coil, a second electromagnetic coil, and a third electromagnetic coil are wound around the main core so that the rotation angle of the magnet can be controlled by the magnetomotive forces of these electromagnetic coils. Further, the above-mentioned first, second, and third electromagnetic coils are controlled such that the magnets are in the neutral position when the power is not supplied. Therefore, even if any one of the electromagnetic coils has a failure, the electromagnetic coil having the failure does not have a great adverse effect on the rotation angle of the magnet. The second electromagnetic coil rotates the magnet in one direction from the neutral position of the magnet, and the throttle valve increases the flow rate of the fluid at a predetermined rate.
The magnet is rotated in the other direction from the neutral position of the magnet, and the flow rate of the fluid is reduced at a predetermined rate by the throttle valve. The first electromagnetic coil rotates the magnet in one direction from the neutral position of the magnet, The flow rate of the fluid is increased by the throttle valve at a rate larger than the rate of increase of the flow rate of the fluid by the electromagnetic coil 1.

〔Example〕

Embodiments of the actuator of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 11 denotes a housing, which is made of aluminum or a resin material such as PBT or nylon.
A bypass passage 18 is formed in the housing 11 to allow intake air before and after the throttle valve of the engine to flow to the engine 23 by bypassing the throttle valve. That is, the intake air from the air filter 22 flows into the bypass passage 18 from the inlet 13 thereof, and the bypass air flows from the outlet 12 to the engine 23 side.

Bearings 6 and 9 are press-fitted into the housing 11, and the drive shaft 8 is rotatably supported by the bearings 6 and 9. A throttle valve 7 is fixed to the drive shaft 8, and the throttle valve 7 variably controls the passage opening cross-sectional area of the bypass passage 18.

The open end of the housing 11 is closed by the end plate 10. Like the housing, the end plate 10 is also made of aluminum or a resin material.

The magnet 5 is fixed to the drive shaft 8. The magnet 5 has a cylindrical shape as shown in FIG. 3, and is magnetized in the diameter direction. The magnet 5 is arranged in the main core 4 made of a magnetic material. A detent groove 14 is formed in the main core 4, and the detent groove 14 makes the magnetic flux loop around the magnet 5 non-uniform, thereby giving the magnet 5 a neutral position.

As shown in FIG. 3, the second coil 20 is wound around one end of the main core, and the third coil 21 is wound around the other end of the main core 4. And the second coil, the third
The first coil 1 is further wound outside the coils 20 and 21. With the coil wound in this way, the main core 4,
The coils 1, 20, 21 are covered with a yoke 3 made of a magnetic material.

A sub core 19 is formed in the direction perpendicular to the main core. The sub-core 19 is also perpendicular to the direction in which the detent groove 14 is formed. With this sub-core 19, the coil 1,
The change in the rotation angle of the magnet 5 is linear when the magnets 20 and 21 are excited.

Next, the operation of the electromagnetic coil will be described with reference to FIGS. 5 to 7 and 8 to 10. FIG. 5 shows a state in which the electromagnetic coil is not excited at all. In this case,
Due to the non-circular shape of the magnetic flux loop due to the shape of the detent groove 14, the magnet 5 is held in the neutral position as shown in FIG. Second coil arranged on one side of the main core 4
When 20 is excited, a magnetic flux loop as shown in FIG. 6 flows in the yoke 3 and the main core 4. Here, in the main core 4, since the magnetic flux is saturated around the detent groove, a part of the magnetic flux flows to the magnet 5 side, and as a result, the magnet 5 rotates in the direction shown in FIG.

Conversely, the third coil arranged on the other side of the main core 4
When 21 is excited, the magnetic flux loop is formed in the opposite direction as shown in FIG. 7, so that the magnet 5 rotates in the opposite direction to that in FIG. The duty ratio of the excited state of the second coil 20 shown in FIG. 6 and the excited state of the third coil shown in FIG. 7 is controlled. That is, one cycle (eg 4m
sec), the second coil 20 is energized for a predetermined time, and the third coil 21 is energized for the other time.
Then, the duty ratio of the time ratio of the energization time is controlled. FIG. 8, FIG. 9, and FIG. 10 show this state. FIG. 8 shows a state in which neither coil is energized, and FIG. 9 shows the relationship between the duty ratio of the time during which the first coil 20 is energized and the flow rate flowing through the bypass passage 18. The eighth,
In FIGS. 9 and 10, the point a indicates the neutral position of the magnet 5.

Thus, by controlling the duty ratio of the energization time ratio to the second coil 21, the distribution angle of the magnet 5 is basically controlled.

FIG. 2 shows this state, and in the figure, a shows a change in the rotation angle of the valve by the second coil 20. In addition, B in the figure shows a change in the rotation angle of the valve due to the magnetomotive force of the third coil 21. As shown in the figure, by controlling the duty ratio of the energization time of the second coil and the third coil, the rotation angle of the magnet 5 is controlled substantially linearly. Further, as is apparent from FIG. 2, the second coil displaces the magnet in a direction to increase the rotation angle of the valve body 7 from the neutral point, and the third coil moves the rotation angle of the valve body 7 from the neutral point a. The magnet 5 is rotated in the opposite direction.

In the actuator of this example, the second coil 20, the third coil
In addition to the coil 21, the first coil 1 is provided. C in FIG. 2 shows changes in the rotation angle of the magnet by the first coil 1. The first coil 1 rotates the magnet 5 in a direction in which the rotation angle of the valve becomes larger than the neutral position.

In this example, the first coil, the second coil, and the third coil are excited based on electric signals from the computer 24, respectively. A signal from the temperature sensor and a signal from the rotation sensor are input to the computer 24. Temperature sensor 26
Is for detecting the engine coolant temperature. That is, in a state where the cooling water temperature of the engine is low, in other words, in a low temperature state (for example, −30 ° C.), it is necessary to increase the bypass air flow rate flowing through the bypass passage 18. On the contrary, when the engine cooling water temperature is in a high temperature range, for example, about 80 ° C., the bypass air flow rate flowing through the bypass passage 18 is not so large. As described above, the engine cooling water temperature has a great influence on the bypass air flow rate, so that the engine cooling water temperature is detected by the temperature sensor 26.

The rotation sensor 25 detects the rotation speed of the engine 23. That is, it is used to determine whether the engine 23 has reached a predetermined rotation value.

In the computer 24, the second coil 20 and the third coil 21 mainly output electric signals for controlling the engine speed. Further, the computer 24 outputs to the first coil 1 a signal which is completely different from the above-mentioned electric signals to the second coil and the third coil. The electric signal output to the first coil 1 becomes a control signal according to the input signal from the temperature sensor 26. That is, in the actuator of this example, the common magnet 5
Rotation control is performed, and the temperature condition is further added to the rotation control value of the magnet by the first coil.

This state will be described with reference to FIG. The second coil and the third coil are both subjected to the same duty ratio control. That is, the second coil 20 is excited for a predetermined time in one cycle, and the third coil is excited for the other time.
21 will be exemplified. In this way, by controlling the excitation time of the second coil 20 and the third coil 21, the duty ratio is controlled, so that the rotation angle of the valve is controlled substantially linearly as indicated by broken lines a and b in FIG. It As a result, the bypass passage
The flow rate of bypass air flowing through 18 is also controlled almost linearly.

In addition to the above control, further, in this example, the rotation angle of the valve body 7 changes according to the electric signal applied to the first coil 1 according to the engine cooling water temperature. The state of L in FIG. 2 indicates a state where the engine cooling water temperature is high, for example, 80 ° C. The state M in FIG. 2 indicates that the engine cooling water temperature is low, for example, −30 ° C. The point N indicates that the engine cooling water temperature is room temperature, for example, the engine cooling water temperature is about 30 ° C. Thus, the first coil 1
The exciting force of the above changes depending on the temperature condition, and the rotation angle of the valve body 7 is guaranteed according to the temperature condition.

As described above, in the actuator of this example, the second coil and the third coils 20 and 21 can perform the bypass flow rate control according to the engine speed, and the first coil can guarantee the temperature.

Moreover, in the actuator of this example, the first coil, the second coil
Any of the coils and the third coils 1, 20, 21 controls the rotation of the magnet in either direction depending on the neutral position of the magnet 5. Therefore, even if some failure occurs in any of the coils, in this case, the failed coil will not affect the magnet 5. In other words,
As a result of the failure, the rotation position of the magnet may fluctuate, but even in that case, the rotation angle of the magnet does not deviate more than the predetermined position. Moreover, if the rotation angle of the magnet 5 deviates from the predetermined value, the bypass air flow rate will fluctuate as a result. Further, the fluctuation of the bypass air flow rate will increase the fluctuation of the engine speed, and therefore the engine speed. Through the computer 24 to the coils 1,20,2
The failure of 1 will be fed back. As a result, when the computer 24 outputs the correction signal, the magnet 5 returns to the predetermined position.

〔The invention's effect〕

As explained above, in the actuator of the present invention,
The air flow rate can be widely controlled by one actuator. Moreover, in the actuator of the present invention, three coils are provided, and each coil rotates the magnet in either direction from the neutral position of the magnet. Therefore, even if each coil should fail, the actuator of the present invention A large malfunction is caused by the second electromagnetic coil and the third electromagnetic coil, the rate of change in the flow rate until the throttle valve moves to the neutral position, and the flow rate until the throttle valve further moves beyond the neutral position. If the rate of change can be the same and the control characteristic of the flow rate can be made linear, the rate of flow rate change until the throttle valve moves to the neutral position by the first electromagnetic coil,
The flow rate control characteristic can be made non-linear by changing the rate of change in the flow rate until the throttle valve further moves beyond the neutral position, and a wide range of flow rate control can be performed with only one actuator.

[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 relationship between the excitation state of the coil shown in FIG. 1 and the improvement angle of the valve, and FIG. 3 is shown in FIG. A-A sectional view, FIG. 4 is a BB sectional view of FIG. 1, and FIGS.
Explanatory diagrams for explaining the rotating states of the magnets, respectively, FIGS.
FIG. 10 is a characteristic diagram showing the characteristics of the duty ratio and the flow rate applied to each coil. 1 …… First coil, 3 …… Yoke, 4 …… Main core, 5 ……
Magnet, 7 ... Throttle valve, 8 ... Drive shaft, 11 ... Housing, 18 ...
… Bypass passage, 20 …… Second coil, 21 …… Third coil, 2
4 ... Computer.

Claims (1)

(57) [Claims] 1. 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 inflow hole and the outflow hole that rotates integrally with the drive shaft. A variably controlled throttle valve, a magnet fixed to the drive shaft, a main core arranged so as to cover the magnet, and first and second coils wound around the main core.
And a third electromagnetic coil, wherein the main core is provided with a detent groove to give the magnet a neutral position, and the second electromagnetic coil moves the magnet in one direction from the neutral position of the magnet. The flow rate of the fluid is rotated by the throttle valve to increase the flow rate of the fluid at a predetermined ratio, the third electromagnetic coil rotates the magnet in the other direction from the neutral position of the magnet, and the throttle valve controls the flow rate of the fluid. Is reduced at a predetermined rate, the first electromagnetic coil rotates the magnet in the one direction from the neutral position of the magnet, and the first electromagnetic coil causes the fluid to flow at a rate higher than the rate of increase in the flow rate of the fluid by the first coil. The rotary solenoid type actuator characterized in that the flow rate of is increased by the throttle valve.