JP2546238B2 - Rotary Solenoid Actuator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic actuator using a coil, for example, adjusting an amount of bypass air 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 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. 57-73839). However, in the conventional actuator, when trying to delicately control the flow rate according to a plurality of signals such as the engine speed and the environmental temperature, the configuration of the actuator and the computer for controlling the actuator becomes complicated,
As a result, there is a problem that a failure or the like is likely to occur. On the other hand, in order to simplify the control circuit etc., in the low temperature range of the engine cooling water temperature, the air flow rate control valve using bimetal or thermo wax controls the air flow rate, and the actuator controlled by the computer only in the high temperature range. The air flow rate is controlled by.
However, in this case, there is a problem that it is difficult to perform accurate control.

[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 enable smooth control of the air flow rate over a wide range by one actuator. A further object of the actuator of the present invention is to make the flow rate control characteristic non-linear. That is, when a predetermined signal current is input to the electromagnetic coil, the control flow rate characteristic changes according to the signal current, but the change rate is the control change rate until the valve body moves to a predetermined value and the valve body. The object of the present invention is to make the control change rate different when the value exceeds a predetermined value and further moves.

[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 the magnet, and a detent groove is formed in the main core so that the magnet is 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 the neutral point for fixing the position of the magnet.
Also, winding the first coil and the second coil around the main core,
This coil allows the magnet to rotate in the predetermined direction.
Further, in the actuator of the present invention, the drive shaft is provided with non-uniform means, and the resistance force of the rotation is different when the drive shaft rotates in one direction from the neutral point position and in the other direction. To do so.

With the above configuration, the magnet rotates according to the signal current input to the coil, but the resistance that prevents the rotation of the magnet is different between the one-direction rotation and the other-direction rotation due to the nonuniform means. Become. As a result, the actuator of the present invention can basically control the rotation of the drive shaft, that is, the valve element according to the signal current input to the coil. However, the control ratio of the rotation control is the rotation of the drive shaft and the throttle valve. It will be changed according to the position.

〔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, which is made of a resin material such as aluminum alloy or PBT nylon. A bypass passage 18 is formed in the housing 1, and an inlet 13 of the bypass passage communicates with an intake pipe on the upstream side of the throttle valve of the engine, and intake air from an air filter 21 flows in.

The outlet 12 of the bypass passage 18 communicates with the intake pipe of the engine by the throttle valve AC, and the bypass air is supplied to the engine 22 from the outlet 12.

Bearings 6 and 9 are fixed in the housing 1, 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 area of the bypass passage 18 as shown in FIG.

A cylindrical magnet 5 is fixed to the end of the drive shaft 8. The 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 the second coil 30 are wound. Also, two detent grooves 14 are formed in the main core 4 so as to face each other. The detent groove 14 makes the magnetic resistance around the magnet 5 non-uniform. That is, a 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 orthogonal to the detent groove 14. The sub-core 32 is provided for the magnet 5 to rotate with good response in response to the signal current input to the coils 20, 20. Furthermore, the main core 4 and the sub core 32
A yoke 3 is provided around the coil so as to surround the coils 20 and 30. Since the yoke 3, the main core 4, and the sub core 32 each form a magnetic loop,
It is made of a magnetic material.

An end plate 11 is fixed to the open end of the housing 1 as shown in FIG. 1, and a boss portion 33 is provided on the end plate 11 coaxially with the drive shaft 8 and at a position facing the drive shaft 8. Has been formed. A spring 10 is arranged between the boss 33 and the end surface of the drive shaft 8. The spring 10 has a spiral shape, one end of which is engaged with the boss portion 33 of the end plate 11 and the other end of which is engaged with the end portion of the drive shaft 8. As shown in FIG. 8, a locking piece 34 of the engaging portion is formed so as to project from the drive shaft 8. The locking piece 34 rotates the drive in one direction (the direction indicated by A in the figure). In this case, the spring 10 is displaced in the unwinding direction, and as a result, the spring 10 receives a resistance force corresponding to the rotational displacement of the drive shaft 8. On the contrary, when the drive shaft 8 is displaced to the other direction side (shown in the B direction in the drawing), the spring 10 does not engage with the locking portion 34, and therefore the drive shaft 8 cannot receive the resistance force of the spring 10. Absent.

The first coil and the second coils 20 and 30 have a computer 2
The electric signal from 3 is input. Various signals are input to the computer 23 from sensors such as a rotation sensor 25 and a temperature sensor 24.

The temperature sensor 24 detects the cooling water temperature of the engine. In other words, the bypass air flow rate needs to flow in a large amount when the engine is warming up, so the temperature sensor 24
This is because it is necessary to determine whether or not the engine has warmed up from the signal from. Further, the rotation sensor 25 determines whether the engine speed in each state is maintained at a predetermined value because the engine speed changes especially in accordance with the flow rate of bypass air passing through the bypass passage 18 and the engine idle speed. This is because it is necessary to make a decision. The output signal from the computer 23 is a duty ratio controlled signal as shown in FIG. That is, the signal from the computer 23 is a 0,1 signal, and the duty ratio is controlled for the time ratio between the 0,1 signals in one cycle (for example, about 4 msec). This signal is a power transistor 41,4
2, the inverted signal is input to one of the power transistors via the 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 20.

When the first coil 20 is energized, a magnetic flux loop is generated as shown in FIG. 9, and as a result, the magnet 5 rotates toward the position direction. Further, when the second coil 30 is energized, a reverse magnetic flux loop 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 the magnet 5 is held in the neutral position shown in FIG. 7 when neither of the coils 20 and 30 is energized, and in that state, the valve body is indicated by the point a in FIG. You will come to the neutral position. When the energization time to one coil becomes longer due to the duty ratio control, the magnet rotates in one direction from the neutral point a, and when the energization time to the other coil becomes longer, the magnet 5 moves to the neutral point a. It will rotate to the other direction side. 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 side, as shown in FIG. The change in the rotation angle is different between the one direction side and the other direction side, with the neutral point a being a problem.

Here, if the rotation of the magnet, that is, the rotation angle of the throttle valve 7 is changed according to the cooling water temperature of the engine, the point M in FIG. 2 is in the state where the water temperature is the lowest, for example, the state where the water temperature is approximately -30 ° C. . Further, point L in FIG. 2 is set to a state where the water temperature is 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, the second
As shown in the figure, the degree of rotation angle sensor of the throttle valve 7 becomes large with respect to the duty ratio control signal output to the computer 23 in the low temperature range from -30 ° C to 30 ° C. On the contrary, in the high temperature range of 30 ° C. to 90 ° C., the change in the rotation angle of the throttle valve 7 becomes relatively small with respect to the control signal output from the computer 23.

As described above, according to the actuator of this example, even in the first coil and the second coil that receive a constant duty ratio control signal, the control ratio can be changed between the low temperature side and the high temperature side with the neutral point a as a boundary. Becomes

Here, in order to change the flow rate according to the rotation angle and the rotation direction of the valve body 7, it is possible to change the valve seat shape as shown in FIG. 3, for example. However, if the valve seat has such a complicated shape and is used so that the passage area can be varied during the rotation of the valve body, the flow and pressure of the air passing through the valve seat 15 becomes non-uniform, and the pressure It becomes difficult to accurately control the tilt angle of the valve body 7 under the influence of the above.

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

Although the spring 10 is provided as the non-uniform means in the above example, the shape of the detent groove 48 may be asymmetrical as shown in FIGS. 11 to 13. That is, the gap between the magnet 5 and the main core 4 may be different between the one rotation direction side and the other rotation direction side of the magnet 5. That is, when the magnet 5 rotates in one direction as shown in FIG. 12, a large magnetic resistance is prevented from occurring between the magnet 5 and the main core 3. On the contrary, when the magnet 5 rotates in the other direction as shown in FIG.
The magnetic resistance between the main core 4 and the main core 4 is increased. With this configuration also, the magnetic resistance becomes nonuniform depending on the rotating direction, and as a result, the same nonuniform effect as that of the spring 10 described above can be achieved.

As explained above, in the actuator of the present invention,
Since the shaft is provided with non-uniform means and the resistance force in the rotating direction is changed depending on whether the shaft rotates in one direction or in the other direction, the actuator control is finely controlled. It becomes possible to do.

[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 an electric signal inputted to the coil shown in FIG. 1 and a flow rate, and FIG. 3 is a comparison of valve seat shapes. FIG. 4 is 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 valve seat shape of the actuator shown in FIG. 1, and FIG. 6 is a BB arrow of FIG. Sectional view, 7th
FIG. 8 is a sectional view taken along the line AA of FIG. 1, FIG. 8 is a sectional view showing the shaft end shape of the actuator shown in FIG. 1, and FIG.
FIG. 10 and FIG. 10 are explanatory views for explaining the magnetic loop of the actuator shown in FIG. 1, and FIGS. 11 to 13 are sectional views showing the main part of another embodiment 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, 3
0 …… Second coil, 48 …… Detent groove forming non-uniform means.

Claims (3)

(57) [Claims] 1. A housing having a fluid passage, a drive shaft rotatably disposed in the housing, a throttle valve fixed to the drive shaft to change an opening area of the fluid passage, and a drive shaft. A fixed magnet, a main core arranged so as to cover the magnet, and first and second coils wound around the main core, and a detent groove is formed in the main core, While making the magnetic resistance non-uniform and allowing the magnet to have a neutral position, the first coil generates magnetism so as to rotate the magnet in one direction,
Further, the second coil generates magnetism so as to rotate the magnet in the other direction side, and further, non-uniform means for making the rotation resistance in one direction side of the magnet and the rotation resistance in the other direction side non-uniform. A rotary solenoid type actuator characterized by being provided. 2. The non-uniform means is a coil spring, one end of which is locked to the drive shaft and the other end of which is engaged with the housing, and when the drive shaft rotates in one direction side, the drive shaft and the housing are separated from each other. Is not engaged with the drive shaft, and no resistance is applied to the drive shaft in the rotation direction.When the drive shaft rotates in the other direction, the drive shaft and the housing are engaged to provide resistance to the rotation of the drive shaft in the other direction. The rotary solenoid type actuator according to claim 1, wherein the rotary solenoid type actuator is provided. 3. The non-uniform means has a non-circular shape in at least one of a detent groove shape and a magnet shape formed in the main core, and the magnet and the main body are rotated when the magnet is rotated in a position direction direction. The magnetic force generated between the magnet and the core and the magnetic force generated between the magnet and the main core when the magnet is rotated in the other direction are different from each other. The rotary solenoid actuator described in the item.