JPS6362979A - Rotary solenoid type actuator - Google Patents

Abstract

PURPOSE:To delicately fine control an actuator, by changing resistance force of a shaft in its rotary direction between the condition the shaft rotates in one direction side and the condition the shaft rotates in the other direction side. CONSTITUTION:A magnet 5 is fixed to a driving shaft 8 to which a throttle valve 7 is fixed. Further a main core 4 is provided so as to cover said magnet 5, and said core 4, forming a detent groove 14, unequally generates magnetic resistance in the periphery of the magnet. In this way, the magnet 5 rotates in accordance with a signal current input to coils 20, 30, but the resistance disturbing a rotation of said magnet is changed by an unequality means between the rotations in one direction side and the other direction side, resulting in the control proportion of controlling the rotation to be changed in accordance with rotary positions of the driving shaft 8 and the throttle valve 7.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electromagnetic actuator using a coil, and is used, for example, to adjust the amount of bypass air before and after the throttle valve of an engine to control the idle speed to a target speed. It is effective when used as an actuator.

[Prior art and its problems]

Conventionally, it has been known to use a solenoid actuator as an idle speed control device for an internal combustion engine of an automobile (for example, Japanese Patent Laid-Open No. 73839/1983). However, with conventional actuators, when trying to perform delicate control of flow rate in response to multiple signals such as engine speed and environmental temperature, the configuration of the actuator and the computer that controls the actuator becomes complicated. There was a problem in that failures and the like were likely to occur. On the other hand, in order to simplify the control circuit, the air flow rate is controlled by an air flow control valve using bimetal or thermowax in the low engine cooling water temperature range, and a computer-controlled actuator is used only in the high temperature range. The air flow rate was controlled by However, in this case, there was a problem in that it was difficult to perform accurate control.

[Problem to be solved by the invention]

The present invention was devised in view of the above points, and an object of the present invention is to enable smooth control of air flow rate over a wide area using one actuator. Furthermore, it is an object of the actuator of the present invention to have nonlinear flow rate control characteristics. In other words, when a predetermined signal current is input to the electromagnetic coil, the controlled flow rate characteristics change depending on the signal current, but the rate of change is determined by the control change rate until the valve body moves to the predetermined value and the valve The purpose is to make the control change rate different when the body moves further beyond a predetermined value.

[Configuration and operation]

In order to achieve the above object, in the present invention, a magnet is fixed to a drive shaft to which a throttle valve is fixed. Further, a main core 4 is provided so as to cover this magnet, and a detent groove is formed in this main core so that the magnet is placed in a neutral position. That is, by providing the detent groove in the main core, the magnetic resistance around the magnet is made non-uniform, thereby providing a neutral point where the magnet is fixed in position. Further, a first coil and a second coil are wound around the main core, and the magnet can be rotated in a predetermined direction by the coils. Furthermore, in the actuator of the present invention, the drive shaft is provided with an uneven means, so that the rotational resistance force is different when the drive shaft rotates in one direction from the above-mentioned neutral point position and when it rotates in the other direction. do it like this.

With the above configuration, the magnet rotates in response to the signal current applied manually to the coil, but the resistance that prevents the magnet from rotating differs between rotation in one direction and the other direction due to the non-uniform means. Become. As a result, the actuator of the present invention can basically control the rotation of the drive shaft, that is, the valve body, according to the signal current input to the coil.
The control ratio of the rotation control is changed according to the rotational positions of the drive shaft and the throttle valve.

〔Example〕

An embodiment of the actuator of the present invention will be described below based on the drawings.

Reference numeral 1 in FIG. 1 denotes a housing, which is molded from a resin material such as aluminum alloy or PBT nylon. A bypass passage 18 is formed in this housing 1, and a passage 13 of the bypass passage communicates with an intake pipe upstream of a throttle valve of the engine, and intake air from an air filter 21 flows therein.

Further, the outlet 12 of the bypass passage 18 communicates with the intake pipe of the engine through throttle valve alternating current, and bypass air is supplied to the engine 22 through the outlet 12.

Bearings 6 and 9 are fixed within the housing 1, and a drive shaft 8 is rotatably supported by the bearings 6 and 9. Further, a throttle valve 7 is fixed to the drive shaft 8, and this throttle valve 7 variably controls the passage opening area of the bypass passage 18, as shown in FIG.

A cylindrical magnet 5 is fixed to the end of the drive shaft 8.

This magnet 5 is surrounded by the main core 4 as shown in FIG. 7, and the main core 4 further includes a first coil 20.
and a second coil 30 is wound thereon. Further, two detent grooves 14 are formed in the main core 4 so as to face each other. This detent groove 14 makes the magnetic resistance around the magnet 8 non-uniform. That is, magnetic resistance is formed by the detent groove 14, and as a result, the magnet 5 is held at the neutral position as shown in FIG. A sub-core 32 is formed on the side of the main core 4 in a direction perpendicular to the detent groove 14. This sub-core 32 is provided so that the magnet 5 rotates with good response in response to the signal current input to the coils 20 and 20. In addition, main core 4
And around the sub-core 32, the yoke 3 has a coil 2o,
It is provided so as to surround 30. This yoke 3 and main core 4. Since the sub-cores 32 each form a magnetic loop, they are made of a magnetic material.

As shown in FIG. 1, an end plate 11 is fixed to the open end of the housing 1.
1 has a boss portion 33 formed coaxially with the drive shaft 8 and at a position facing the drive shaft 8. Further, a spring 10 is disposed between the boss portion 33 and the end surface of the drive shaft 8. The spring 10 has a spiral shape, and one end thereof engages with the boss portion 33 of the end plate 11.
The other end engages with the end of the drive shaft 8. As shown in Fig. 8, this engaging part has a locking piece 34 protruding from the drive shaft 8, and this locking piece rotates the drive in one direction (the direction indicated by ``inward'' in the figure). In this case, spring 10
is displaced in the direction of unwinding, and as a result, from the spring 10,
A resistance force corresponding to the rotational displacement of the drive shaft 8 is applied. Conversely, when the drive shaft 8 is displaced in the other direction (indicated by direction B in the figure), the spring 10 does not engage with the locking portion 34, and therefore the drive shaft 8 does not receive the resistance force exerted by the spring 10. do not have.

Note that an electrical signal from the computer 23 is input to the first coil and the second coil 20.30. computer 23
Various signals are input from sensors such as the rotation sensor 25 and the temperature sensor 24.

The temperature sensor 24 detects the engine cooling water temperature. In other words, since a large amount of bypass air needs to flow when the engine is warmed up, the temperature sensor 2
This is because it is necessary to determine whether the engine is warm or not based on the signal from step 4 onwards. Moreover, the rotation sensor 25 is
Since the engine speed, especially the idle speed of the engine, changes depending on the flow rate of bypass air passing through the bypass passage 18, it is necessary to determine whether the engine speed is maintained at a predetermined value in each state. This is because there is. The output signal from the computer 23 becomes a signal whose duty ratio is controlled as shown in FIG. That is, the signal from the computer 23 is a 0, 1 signal, and the duty ratio is controlled to control the time ratio between the 0.1 signals in one cycle (for example, about 4 mesc). This signal is input to power transistors 41 and 42, and an inverted signal is input to one of the power transistors via an inverter 40. As a result, the energization time of the first coil 20° and the second coil 30 is controlled at a rate according to the duty ratio. That is, the longer the time for energizing one coil 20, the shorter the time for energizing the other coil 30.

Note that when the first coil 20 is energized, a magnetic flux loop occurs as shown in FIG. 9, and as a result, the magnet 5 rotates in the position direction. Further, when the second coil 30 is energized, a magnetic flux loop in the opposite direction is generated as shown in FIG. 10, and the magnet 5 rotates in the other direction. Therefore, the first coil 20. By controlling the energization time to the second coil 30, the rotational position of the magnet 5 can be controlled to a predetermined value.

Note that when neither of the coils 20, 30 is energized, the magnet 5 is held at the neutral position shown in FIG. When it comes to the neutral position. When the energization time to one coil becomes longer due to duty ratio control, the magnet 5 rotates in one direction from its neutral point a, and when the energization time to the other coil becomes longer, the magnet 5 rotates from the neutral point a. It will rotate more in the other direction. This state is shown in FIG.

Here, since the resistance force of the spring 10 is applied to the drive shaft 8 only when the spring rotates in one direction, the rotation angle of the magnet 5 changes, as shown in FIG.
The rotation angle change of the throttle valve 7 is different on one side and the other side with respect to the neutral point a.

If the rotation of the magnet, that is, the rotation angle of the throttle valve 7, is changed according to the engine cooling water temperature, m
The point is set at the lowest water temperature, for example, about 130°C. Further, at one point in FIG. 2, the water temperature is at room temperature, for example, about 30°C. Further, point n in FIG. 2 is a state where the water temperature is high, for example, about 90°C. In this way, when the control signal is output from the computer 23, as shown in FIG. On the other hand, the rotation angle sensor degree of the throttle valve 7 increases. Conversely, in a high temperature range of 30° C. to 90° C., the rotation angle change of the throttle valve 7 is relatively small in response to the control signal output from the computer 23.

Thus, according to the actuator of this example, the first coil receives a constant duty ratio control signal.

Even in the case of the second coil, its control ratio can be changed between the low temperature side and the high temperature side with the neutral point a as the boundary.

Here, in order to vary the flow rate according to the rotation angle and rotation direction of the valve body 7, it is conceivable to change the shape of the valve seat, as shown in FIG. 3, for example. However, if the shape of the valve seat is complicated and the passage area is changed during rotation of the valve body, the flow and pressure of air passing through the valve seat 15 will become uneven, and the pressure Under the influence of such factors, it becomes difficult to accurately control the inclination angle of the valve body 7.

On the other hand, in the actuator of this example, the spring 10 is provided as a non-uniform means at a position unrelated to the shape of the valve body and the valve seat, so the shape of the valve seat 15 is a rectangular shape that is axisymmetric as shown in FIG. It is possible to do so. Of course, the shape of the valve seat may be other than the shape shown in FIG. 5, such as a circular shape or a nine-circular shape.

In the above example, the spring 10 is provided as the non-uniform means, but as shown in FIGS. 11 to 13, the shape of the detent groove 48 may be asymmetrical. That is, the gap between the magnet 5 and the main core 4 may be made different between the one rotation direction side of the magnet 5 and the earth rotation direction side.

That is, when the magnet 5 rotates in one direction as shown in FIG. 12, large magnetic resistance is not generated between the magnet 5 and the main core 3. Conversely, as shown in FIG. 13, when the magnet 5 rotates in the other direction, the magnetic resistance between the magnet 5 and the main core 4 is increased. With this configuration as well, the magnetic resistance becomes non-uniform depending on the direction of rotation, and as a result, it is possible to achieve the same non-uniform effect as the above-mentioned spring IO.

As explained above, in the actuator of the present invention, the shaft is provided with an uneven means, and the resistance force in the rotation direction is changed between the state in which the shaft rotates in one direction and the state in which it rotates in the other direction. This makes it possible to control the actuator in a more precise manner.

[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 relationship between the electric signal manually applied to the coil shown in Fig. 1 and the flow rate, and Fig. 3 is a comparison of valve seat shapes. An explanatory diagram for explanation, FIG. 4 is an electric circuit diagram of the coil shown in FIG. 1, FIG. 5 is an explanatory diagram showing the shape of the valve seat of the actuator shown in FIG. 1, and FIG. 7 is a sectional view taken along arrows -■ in FIG. 1, FIG. 8 is a sectional view showing the shape of the shaft end of the actuator shown in FIG. 1, and FIGS. FIG. 1 is an explanatory diagram for explaining the magnetic loop of the illustrated actuator, and FIGS. 11 to 13 are sectional views showing essential parts of other embodiments of the actuator of the present invention. 1...Housing, 3...Yoke, 4...Main core. 5... Magnet, 7... Throttle valve, 8... Drive shaft, 10
. . . Spring forming non-uniform means, 18 . . . Bypass passage. 20...first coil, 30...second coil, 48...
・Detent groove means non-uniformity.

Claims (3)

[Claims] (1) A housing having a fluid passage, a drive shaft rotatably disposed within the housing, a throttle valve fixed to the drive shaft for varying the opening area of the fluid passage, and a throttle valve fixed to the drive shaft for varying the opening area of the fluid passage. a magnet, a main core disposed to cover the magnet, and first and second coils wound around the main core, with a detent groove formed in the main core and a magnetic The resistance is made nonuniform so that the magnet has a neutral position, and magnetism is generated so as to rotate the first coil and the magnet in one direction, and the second coil rotates the magnet in the other direction. 1. A rotary solenoid actuator, comprising means for generating magnetism and for making rotational resistance in one direction and rotational resistance in the other direction of the magnet non-uniform. (2) The uneven means is a coil spring having one end engaged with the drive shaft and the other end engaged with the housing, which engages the drive shaft and the housing when the drive shaft rotates in one direction. so as not to provide resistance in the rotation direction to the drive shaft, and when the drive shaft rotates in the other direction, the drive shaft and the housing are engaged to provide resistance to rotation in the other direction of the drive shaft. A rotary solenoid actuator according to claim 1, characterized in that the rotary solenoid actuator is configured as follows. (3) In the non-uniform means, at least one of the detent groove shape formed in the main core and the magnet shape is non-circular, and when the magnet rotates in the position direction, the magnet and the main core Claim 1, wherein the magnetic force generated between the main core and the main core is different from the magnetic force generated between the magnet and the main core when the magnet rotates in the other direction. rotary solenoid actuator.