JPH084931A - Electric flow rate adjusting valve, and flow rate control device having the same - Google Patents

Abstract

PURPOSE:To carry out the sure operation even when foreign matters are present in the fluid flowing in a valve, simplify the structure, and miniaturize the device. CONSTITUTION:A rotor 30 of a motor 20 is rotatable and provided in a motor casing 21 in a movable manner in the same direction as the moving direction of a valve disk 17. One end part of a rotary shaft 31 of the rotor 30 is extended into a flow passage 12 of a valve casing 11, the valve disk 17 is fixed to this end, and a male screw 35 is formed on the other end part. A female screw 25 to be screwed with the male screw 35 of the rotary shaft 31 is formed on the motor casing 21. In addition, the rotary shaft 31 is pierced through the motor casing 21, and supports the rotary shaft 31 in a rotatable and movable manner, and a bearing 50 to block the flow passage 12 in the valve casing 11 and the space 22 in the motor casing 21 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric flow control valve for operating a valve body by using a motor and a flow control device equipped with the electric flow control valve.

[0002]

2. Description of the Related Art Conventionally, as an electric flow rate control valve for operating a valve body by using a motor, for example, Japanese Patent Laid-Open No. 4-276 is known.
Some are disclosed in Japanese Patent No. 166.

This electrically operated flow control valve has a stepping motor having a stator having a coil and a rotor having a permanent magnet, and a valve having a valve casing and a valve body. Inside the annular permanent magnet, a nut member having an internal thread formed on the inner peripheral side is fixed. A shaft having a male screw formed at one end is screwed into the nut member. This shaft is constrained so that it rotates with respect to the nut member but does not rotate with respect to the motor casing. The other end of the shaft is in contact with the end of a valve rod integrally formed with the valve body via a spring.

When moving the valve element with respect to the valve casing, an electric current is applied to the coil to rotate the rotor. When the permanent magnet of the rotor rotates, the nut member fixed to this permanent magnet also rotates. Since the shaft screwed to the nut member is constrained from rotating with respect to the motor casing, when the nut member rotates relative to the motor casing, the shaft moves in the longitudinal direction of the shaft. As a result, the valve rod and the valve body are pushed and moved by the shaft via the spring.

By the way, in the above-mentioned conventional techniques, in addition to the bearing of the rotor, a bearing is required not only for the shaft and the valve stem but also for a member for restraining the shaft from rotating with respect to the motor casing. Therefore, there is a problem that the structure becomes complicated and the manufacturing cost becomes high, and the valve itself becomes large. Therefore, as an electric flow rate control valve that simplifies the structure and reduces the size, there is, for example, the one described in Japanese Patent Laid-Open No. 60-69377.

In this electric flow rate control valve, a rotor composed of a permanent magnet and a rotary shaft is rotatably provided with respect to the stator and is movable in the longitudinal direction of the rotary shaft, and a valve body is provided at the tip of the rotary shaft. Is fixed, and the valve element is moved by moving the rotor together with the rotor in the longitudinal direction of the rotary shaft. Specifically, a screw screw is formed between the valve body of the rotary shaft and the permanent magnet, and a female screw that is screwed into the screw screw is formed in the casing. The rotary shaft screwed into the female screw formed in the casing moves in the longitudinal direction of the rotary shaft as the rotary shaft rotates. As a result, the valve element fixed to the tip of the rotary shaft moves. In this conventional technique, by integrating the valve body and the rotary shaft in this way, the valve body rotates with the rotation of the rotary shaft, but the number of bearings can be reduced and the structure can be simplified. Also, we are aiming for miniaturization.

[0007]

However, in the technique disclosed in Japanese Patent Laid-Open No. 60-69377, although the structure can be simplified and downsized, the screw screw and the casing formed on the rotating shaft can be achieved. Since the female screw formed on the valve comes into contact with the fluid flowing in the valve casing, there is a problem that when the fluid contains foreign matter, the rotary shaft and the valve element become difficult to operate.

The present invention has been made by paying attention to such a conventional problem, and can reliably operate even if a fluid contains a foreign substance, and can simplify the structure and reduce the size thereof. An object is to provide an electric flow control valve and a flow control device including the same.

[0009]

In order to achieve the above-mentioned object, an electric flow control valve has a valve casing having a fluid flow passage, and a closed position for closing the flow passage. A valve body that is movably provided between an open position that opens the flow path, and a motor that moves the valve body of the valve,
An annular stator configured to have any one of a coil and a permanent magnet, and the other of the coil and the permanent magnet arranged on the inner peripheral side of the annular stator (hereinafter,
A rotor side magnetic field generating member) and a rotor configured to have a rotating shaft to which the rotor side magnetic field generating member is fixed, and the stator and the rotor are covered and the stator is fixed. The rotor has a motor casing that is rotatable on the inner peripheral side of the annular stator and is movable in the same direction as the moving direction of the valve element and by a movement amount of the valve element or more. Is extended to the inside of the flow passage of the valve casing, and at one end of the rotation shaft extending to the inside of the flow passage, the relative positional relationship with the rotation shaft in the moving direction of the valve body does not change. A valve body is attached, and a male screw or a female screw is formed in a screw shape around the central axis in the longitudinal direction of the rotary shaft at the other end of the rotary shaft. Shaped at the other end A female screw or a male screw that is screwed to the male screw or the female screw that is formed is formed, the rotating shaft penetrates and supports the rotating shaft so as to be rotatable and movable, and the flow path in the valve casing and the It is characterized by comprising a bearing that shields the space inside the motor casing.

Here, the electrically operated flow rate control valve attaches the rotary shaft in a direction from an open position to a closed position of the valve body or in a direction from a closed position to an open position relative to the motor casing. It is preferable to provide a biasing member for biasing.

In the electrically operated flow control valve, a guide recess or a guide protrusion extending parallel to the moving direction of the valve body is formed in the valve casing, and the valve body is provided with the guide casing. An engaging convex portion or an engaging concave portion that is engageable with the guide concave portion or the guide convex portion is formed, and is configured to be relatively immovable and relatively rotatable in the moving direction of the valve body with respect to the rotation shaft A fitting portion into which the one end of the rotary shaft is fitted is formed, and a fitted portion that fits into the fitting portion of the valve body is formed at the one end of the rotary shaft. May be.

[0012]

When the current flowing through the coil is changed, the magnetic field around the coil changes. The permanent magnet is affected by the change in the magnetic field around the coil and generates a rotational force with respect to the coil, and as a result, the rotor rotates. Since the rotating shaft of the rotor is screwed into the female screw or the male screw of the motor casing, the rotor moves in its longitudinal direction as the rotor rotates. As a result, the valve element fixed to one end of the rotary shaft of the rotor moves between the open position and the closed position.

The flow passage in the valve casing and the space in the motor casing are partitioned by bearings. For this reason,
Even if solid foreign matter is mixed in the fluid flowing in the valve casing, the foreign matter hardly enters the motor casing. However, since the bearing has a very small gap in order to ensure the rotation of the rotating shaft, foreign matter may get into the motor casing. However, since the screw that is extremely reluctant to mix foreign matter is located on the opposite side of the bearing from the magnet mounting part of the rotating shaft, foreign matter that has entered the motor casing through the bearing gap does not reach the screw. rare. Therefore, in the present invention, even if the solid foreign matter is mixed in the fluid flowing in the valve casing, the rotation shaft can be surely rotated and moved.

Further, according to the present invention, since the valve body, the portion serving as the valve rod (a part of the rotary shaft) and the rotary shaft are integrated, it is not necessary to provide a bearing for each of them, and the number of parts is reduced. Can be reduced. Further, in the present invention, since the female screw or the male screw is formed on the motor casing itself, it is not necessary to separately provide a nut member unlike the one described in JP-A-4-276166. The number of parts can be reduced.

[0015]

Various embodiments embodying the present invention will be described below with reference to the accompanying drawings.

First, a first embodiment of the electric flow control valve according to the present invention will be described with reference to FIGS. 1 and 2.
The electrically operated flow control valve of the present embodiment includes a valve 10 and this valve 10
And a stepping motor 20 that operates a valve body 17 that constitutes a part of the above.

The valve 10 is provided so as to be movable between a valve casing 11 in which a fluid passage 12 is formed and a closed position for closing the passage 12 and an open position for opening the passage. It has a body 17. The flow path 12 formed in the valve casing 11 is L-shaped, one arm side of this L-shape forms the inlet side flow path 13, and the other arm side of the L-shape is the outlet side flow path 14. And the bent portion of L-shape forms the valve body moving space 1
5 is formed. The outlet side flow passage 14 is connected to the valve body moving space 15
A valve seat 16 that is in contact with the valve body 17 is fixed at the boundary between the and. The valve body 17 is located on the central axis of the outlet-side flow passage 14 between a closed position where it contacts the valve seat 16 and closes the flow passage, and an open position where the flow passage is opened apart from the valve seat 16. Is provided in the valve body moving space 15 so as to be movable.

The stepping motor 20 comprises an annular stator 40 having a coil 41, a permanent magnet 36 and a rotary shaft 31 arranged on the inner peripheral side of the annular stator 40. Rotor 30 and rotating shaft 31
Bearings 50 and 51 that rotatably support the motor and a motor casing 21 that covers them. The rotating shaft 31 of the rotor 30 is provided inside the motor casing 21 so that the central axis of the rotor 30 is located on the central axis of the outlet side flow passage 14 of the valve 10.

The rotary shaft 31 has a magnet mounting portion 33 formed substantially at the center in the longitudinal direction thereof.
The valve body mounting portion 32 is formed on one side of the magnet mounting portion 3, and the screw forming portion 34 is formed on the other side of the magnet mounting portion 33. The magnet mounting portion 33 is formed such that its diameter is larger than the diameters of the valve body mounting portion 32 and the screw forming portion 34 on both sides. The valve body mounting portion 32 of the rotary shaft 31 is used for the valve body 1 in the valve casing 11.
7 extends to the moving space 15, and the valve body 17 is fixed to the tip portion thereof. A spiral male screw 35 is formed around the central axis of the rotary shaft 31 at the tip of the screw forming portion 34 of the rotary shaft 31. Magnet mounting portion 33 of the rotating shaft 31
An annular permanent magnet 36 is fixed to the outer periphery of the. When fixing the permanent magnet 36, a concave portion or a convex portion is formed on the outer circumference of the magnet mounting portion 33, while a convex portion or a concave portion is formed on the inner circumference of the permanent magnet 36 to form the concave portion or the convex portion of the magnet mounting portion 33. It is preferable that the convex portion or the concave portion of the permanent magnet 36 is fitted in and the permanent magnet 36 is fixed so that the permanent magnet 36 does not rotate relative to the rotating shaft 31. Also here
Although the rotating shaft 31 is made of metal, it may be made of resin. In this case, the permanent magnet 3 is placed in the mold for molding the rotary shaft.
It is preferable to insert 6 to mold the resinous rotary shaft so that the resinous rotary shaft and the permanent magnet are integrated.
Further, here, the rotary shaft 31 and the valve body 17 are separately formed, and then the valve body 17 is fixed to the rotary shaft 31, but the rotary shaft and the valve body may be integrally formed. By integrally forming the rotary shaft and the valve body in this manner, the manufacturing cost can be suppressed. However, depending on the type of fluid, if a special material with corrosion resistance and wear resistance must be used as the material of the valve element, it is better to form the rotary shaft and valve element separately to reduce the manufacturing cost. Sometimes it is.

A rotor housing space 22 for housing the rotor 30 and a stator housing space 23 for housing the stator 40 are formed inside the motor casing 21. In the rotor housing space 22, the rotary shaft 31 is arranged in the longitudinal direction of the valve body 1.
It is formed to be long in the longitudinal direction of the rotary shaft 31 so that the rotary shaft 31 can be moved over the moving distance of 7. One side of the rotor housing space 22 faces the valve body moving space 15 of the valve 10 via the bearing 50. Further, on the inner peripheral surface of the motor casing 21 forming the other side of the rotor housing space 22, the rotating shaft 31 is provided.
The female screw 25 with which the male screw 35 is screwed is formed.

The valve body mounting portion 32 of the rotary shaft 31 penetrates through one side of the rotor housing space 22, so that the rotary shaft 31 is rotatable and movable in its longitudinal direction. The valve casing 11 supports the middle body part of 32.
A sliding bearing 50 is provided to shield the valve body moving space 15 inside and the rotor housing space 22 inside the motor casing 21. Further, on the other side of the rotor housing space 22, the rolling bearing 5 that supports the middle body of the screw forming portion 34 of the rotating shaft 31 so that the rotating shaft 31 can rotate and move in the longitudinal direction thereof.
1 is provided. This rolling bearing 51 has an inner ring 52
And an outer ring 53 and balls 54 arranged between them. The inner ring 52 of the rolling bearing 51 is attached to the middle body of the screw forming portion 34 so as to be movable in the longitudinal direction relative to the rotating shaft 31 and non-rotatable around its central axis. On the other hand, the outer ring 53 of the rolling bearing 51 is
It is fixed to the motor casing 21 via a shim 45 of a stator 40 described later. A coil spring 56 is arranged in a contracted state around the screw forming portion 34 of the rotating shaft 31 and between the rolling bearing 51 and the magnet mounting portion 33. One end of the coil spring 56 is in contact with the end surface of the rotating shaft 31 where the magnet mounting portion 33 moves to the screw forming portion 34,
The other end of the coil spring 56 is in contact with the end surface of the inner ring 52 of the bearing.

The stator housing space 23 is formed in a ring shape on the outer circumference of the permanent magnet 36 of the rotor 30 arranged in the rotor housing space 22. The annular stator 40 is arranged in the stator housing space 23 and is fixed thereto. The stator 40 includes two coils 41, 41 wound around the rotary shaft 31 and arranged in series in the longitudinal direction of the rotary shaft 31.
Bobbins 42, 42 in which the coils 41, 41 are respectively housed, stator parts (A) 43, 43 and stator parts (B) 44, 44 for supporting the respective bobbins 42, 42, and these It has a shim 45 for adjusting the position in the moving direction of the valve element in the stator housing space 23.

Valve casing 11 and motor casing 21
Flanges 18 and 28 are formed on and, respectively. The valve casing 11 and the motor casing 21 are connected by bolts 58 penetrating the respective flanges 18 and 28. An O-ring 57 is embedded in the flange end surface of the motor casing 21 in order to prevent fluid from leaking to the outside from between the flange end surface of the valve casing 11.

Next, the operation of the electric flow control valve of this embodiment will be described. When a pulsed current is passed through the coil 41 of the stator 40, a magnetic field is generated around the coil 41. When the current flowing through the coil 41 is changed, the magnetic field around the coil 41 changes. The permanent magnet 36 fixed to the rotation shaft 31 of the rotor 30 is affected by the change in the magnetic field around the coil 41 to generate a rotational force, and as a result, the rotor 30 rotates. Rotating shaft 31 of rotor 30
Is screwed into the female screw 25 of the motor casing 21, so that the rotor 30 moves in the longitudinal direction as the rotor 30 rotates. As a result, the valve body 17 fixed to one end of the rotary shaft 31 of the rotor 30 moves between the open position and the closed position while rotating.

The coil spring 56 arranged around the screw forming portion 34 of the rotary shaft 31 plays a role of substantially eliminating the play of the rolling bearing 51 and the play of the screws 25 and 35. As shown in FIG. 2, there is a slight gap G between the male screw 35 and the female screw 25 so that the male screw 35 can rotate relative to the female screw 25. Specifically, male screw 3
5 is rotating in a certain direction, the surface 35 s on one side of the crest of the male screw 35 and the surface 2 on one side of the trough of the female screw 25.
The surface of the male screw 35 on the other side 35t comes into contact with
And the surface 25t on the other side of the valley of the female screw 25 are separated. However, when the rotation direction of the male screw 35 is changed, the surface 35s on one side of the crest of the male screw 35 and the surface 25s on one side of the valley of the female screw 25 are separated, and the other side of the crest of the male screw 35 is separated. 35t and the surface 25t on the other side of the valley of the female screw 25 come into contact with each other. Therefore, when the rotating shaft 31 starts to rotate or when the rotating direction changes, the correspondence between the rotation amount of the rotating shaft 31 and the moving amount of the rotating shaft 31 cannot be established, and as a result, the position of the valve body 17 is changed. It cannot be controlled accurately. In addition, regarding the rolling bearing 51,
Similarly, when the rotating shaft 31 starts to rotate or when the rotating direction changes, the contact state between the ball 54 and the inner ring 52 and the outer ring 53 changes. Therefore, in this embodiment, the coil spring 56 urges the rotating shaft 31 in the longitudinal direction (rightward direction in FIG. 1) so that whichever direction the rotating shaft 31 rotates, the peak of the male screw 35 is always generated. The surface 35t on one side and the surface 25t on one side of the valley of the female screw 25 come into contact with each other, and the surface 35s on the other side of the crest of the male screw 35 and the surface 25s on the other side of the valley of the female screw 25. Are in a distance. Further, the coil spring 56 is provided on the inner ring 52 of the rolling bearing 51.
Also in the longitudinal direction of the rotary shaft 31 (left direction in FIG. 1)
Therefore, even if the inner ring 52 and the ball 54 try to move relative to the outer ring 53 fixed to the motor casing 21 due to the movement of the rotating shaft 31, this movement is restrained and the ball 54 And inner ring 52 and outer ring 53
The contact state with does not change. Therefore, even if the rolling bearing 51 or the screws 25 and 35 rattle, the correspondence between the rotation amount of the rotating shaft 31 and the moving amount of the rotating shaft 31 can be firmly secured, and accurate position control of the valve body 17 can be performed. Can be realized. In this embodiment, the rotating shaft 31 is biased to the left by the coil spring 56 in FIG. Even if the rotary shaft 31 is urged to the right side by arranging the rotary shaft 31 with the portion 33, the same effect can be obtained with respect to the play of the screws 25 and 35. However, in this case, since the urging force of the coil spring 56 cannot be applied to the rolling bearing 51, it goes without saying that the play of the rolling bearing 51 cannot be suppressed.

The passage 12 in the valve casing 11 and the space 22 in the motor casing 21 are partitioned by a slide bearing 50. Therefore, even if solid foreign matter is mixed in the fluid flowing in the valve casing 11, the foreign matter hardly enters the motor casing 21.
However, in the plain bearing 50, in order to ensure the rotation of the rotating shaft 31, there is a slight gap between the inner peripheral surface of the sliding bearing 50 and the outer peripheral surface of the valve body mounting portion 32 of the rotating shaft 31. It may get inside the casing 21. However, the rolling bearing 51 and the screws 25, 35 that are extremely reluctant to mix foreign matter
Is located on the opposite side of the slide bearing 50 with the magnet mounting portion 33 of the rotary shaft 31 as a center, foreign matter that has entered the motor casing 21 through the gap of the slide bearing 50 is prevented from rolling on the rolling bearing 51 and the screws 25 and 35. Rarely reaches. Therefore, in this embodiment, even if the solid foreign matter is mixed in the fluid flowing in the valve casing 11, the rotating shaft 31 can be reliably rotated and moved.

Further, in this embodiment, the valve body mounting portion 32 of the rotary shaft 31 plays the role of the valve rod, and the valve body 17 is fixed to the end portion of the rotary shaft 31, that is, the valve body. 17, since the portion that plays the role of the valve rod and the rotary shaft 31 are integrated, there is no need to provide a bearing for each of them, and the structure can be simplified.

Next, a second embodiment of the electric flow control valve according to the present invention will be described with reference to FIG. In the electric flow rate control valve of the first embodiment, the rotary shaft 31 is formed with the male screw 35 and the motor casing 21 is formed with the female screw 25. A female screw 35a is formed on the rotary shaft 31a, and the motor casing 21
A male screw 25a is formed on a, and other configurations are basically the same as those of the first embodiment.

The rotating shaft 31a of the present embodiment has a magnet mounting portion 3
A valve body mounting portion 32 similar to that of the first embodiment is provided on one side of 3a.
Are formed. The magnet mounting portion 33a is formed with a screw hole 34a recessed from the other side to one side, and a female screw 35a is formed on the inner peripheral surface thereof. The motor casing 21a is formed with a male screw 25a that projects from the open position of the valve body 17 toward the closed position (leftward in FIG. 3) and can be screwed into the female screw 35a of the rotary shaft 31a.

Male screw 25a of motor casing 21a
Is screwed into the female screw 35a of the rotary shaft 31a, and the coil spring 56a is arranged in a compressed state in the screw hole 34a of the rotary shaft 31a. This coil spring 56a is
One of the ends is in contact with the bottom of the screw hole 34a, and the other end is in contact with the tip of the male screw 25a.

As described above, even if the electric flow control valve is constructed, it is possible to obtain basically the same effect as that of the first embodiment. Further, in the electric type flow control valve of the present embodiment, the male screw 25 protruding inward is provided on the motor casing 21a.
female screw 3 that forms a and can be screwed into the male screw 25a of the motor casing 21a at the magnet mounting portion 33a of the rotating shaft 31a.
Since 5a is formed and the inside of the magnet mounting portion 33a is effectively used, the stepping motor 20a can be downsized. In this embodiment, the rolling bearing 51 of the first embodiment is not used, but the rotary shaft 31a
One side of the rotary shaft 31 is supported by the slide bearing 50.
Since the other side of a is substantially supported by the male screw 25a and the rotary shaft 31a is supported in a double-supported state, the rotary shaft 3a
Almost no blurring of 1a occurs.

By the way, in the above embodiment, the valve body 17
Is fixed to the rotating shafts 31 and 31a, and therefore rotates and moves as the rotating shafts 31 and 31a rotate and move. For this reason, when the valve body 17 contacts the valve seat 16, the valve body 17 and the valve seat 16 rub against each other, and the valve body 17 and the valve seat 16
Wears out a lot. Therefore, as a third embodiment of the electric flow rate control valve, a valve body 17 that does not rotate will be described with reference to FIGS. 4 and 5. The electric flow rate control valve of the present embodiment is a modification of the first embodiment, in which the valve body 17b is rotatably attached to the valve body attachment portion 32b of the rotary shaft 31b.

The valve body 1 is provided on the inner peripheral surface of the valve casing 11b.
A guide recess 19 extending parallel to the moving direction of 7b is formed. A thin cylinder passing through the central axis of the rotating shaft 31b is formed at the tip of the valve body mounting portion 32b of the rotating shaft 31b.
A disk having a diameter larger than the diameter of the cylinder that passes through the central axis of the rotation shaft 31b is formed at the tip of the cylinder. The column and the disk protrudingly provided at the tip of the valve body mounting portion 32b form a fitted portion 32s that fits into a fitting portion 17s of the valve body 17b described later.

A rotary shaft 31b is provided on the rotary shaft side of the valve body 17b.
Fitting portion 17s which is recessed corresponding to the shape of the fitted portion 32s of
Are formed. The valve body 17b is formed with an engagement projection 17t that can be engaged with the guide recess 19 of the valve casing 11b from the outer peripheral surface thereof. The valve body 17b has a rotating shaft 31.
In the moving direction of the valve body 17b with respect to b, the rotary shaft 31 is fixed to the fitting portion 17s so as not to be relatively movable and relatively rotatable.
The fitted portion 32s of b is fitted. Also, the valve body 1
7b is movable relative to the valve casing 11b with respect to a predetermined moving direction of the valve body 17b and is not rotatable relative to the valve casing 11b, and its engaging protrusion 17t engages with the guide recess 19 of the valve casing 11b. There is.

When the rotary shaft 31b moves in the longitudinal direction of the rotary shaft 31b due to the rotation, the valve body 17b is attached so as not to move relative to the rotary shaft 31b, and therefore moves with the movement of the rotary shaft 31b. . At this time, the valve body 17b is attached to the rotary shaft 31b so as to be relatively rotatable with respect to the rotary shaft 31b, and the engagement protrusion 17t of the valve body 17b engages with the guide recess 19 of the valve casing 11b. Casing 11
Since it cannot rotate relative to b, even if the rotating shaft 31b rotates, it does not rotate in relation to the valve casing 11b. Therefore, when the valve body 17b comes into contact with the valve seat 16, as in the above embodiments, the valve body 17b and the valve seat 16 are not in contact with each other.
Will not rub against each other and the amount of wear of the valve body 17b and the valve seat 16 will not increase.

In this embodiment, the fitted portion of the valve body mounting portion 32b is formed in a convex shape and the fitting portion of the valve body 17b is formed in a concave shape. The fitted portion may be formed in a concave shape, and the fitting portion of the valve body 17b may be formed in a convex shape. Similarly, the guide portion formed on the valve casing 11b may be formed in a long convex shape parallel to the moving direction of the valve body 17b, and the engaging portion of the valve body 17b may be formed in a concave shape. Further, in the motors of the above embodiments, the stator 40 has the coil 4
1 and the rotor 30 has the permanent magnet 36, the present invention is not limited to this, and the stator has the permanent magnet and the rotor has the coil. The present invention may be applied to.

Next, application modes of the electric flow rate control valves of the various embodiments described above will be described with reference to FIG. FIG. 6 shows a schematic configuration around an engine of a vehicle.

The engine 60 has an intake pipe 6 at its intake port.
1 is attached, and an exhaust pipe is attached to its exhaust port. The intake pipe 61 is provided with a main air flow rate adjusting valve 63 for adjusting the flow rate of air passing therethrough, and a fuel injection valve 64 for injecting fuel downstream of the adjusting valve 63. The fuel sucked up by the fuel pump 67 from the fuel tank 65 is supplied to the fuel injection valve 64.
The fuel tank 65 and the intake pipe 61 include a purge pipe 71 for purging the fuel vapor in the tank 65 into the intake pipe 61.
Connected by. In the middle of the purge pipe 71, a canister 66 for temporarily storing fuel vapor from the fuel tank 65, and a fuel vapor flow rate control valve for adjusting the supply amount of fuel vapor from the canister 66 into the intake pipe 61. And 72 are provided. The intake pipe 61 includes a main air flow rate control valve 6
A bypass intake pipe 73 is provided for guiding a part of the air on the upstream side of No. 3 to the downstream side without passing through the main air flow rate control valve 63. The bypass intake pipe 73 is provided with a bypass air flow rate adjusting valve 74 for adjusting the flow rate of the air flowing therethrough. Further, the intake pipe 61 and the exhaust pipe 62 are configured to guide a part of the exhaust gas flowing in the exhaust pipe 62 into the intake pipe 61.
The exhaust gas recirculation pipe 75 is connected. The exhaust gas recirculation pipe 75 is provided with an exhaust gas flow rate adjusting valve 76 for adjusting the flow rate of the exhaust gas passing therethrough. Of the flow rate control valves, the fuel vapor flow rate control valve 72, the bypass air flow rate control valve 74, and the exhaust gas flow rate control valve 76 are the electric flow rate control valves of the above-described embodiments.

Here, the control of each electric flow rate control valve will be specifically described. First, the control of the fuel vapor flow rate control valve 72 will be described. When the rotation speed of the engine 60 increases to some extent, the pressure in the intake pipe 61 increases to the (−) side, and the fuel in the canister 66 tries to enter the intake pipe 61 via the purge pipe 71. Therefore, ECU (En
The gine control unit) 68 controls the fuel vapor flow rate control valve 72 when the engine enters a predetermined operating state (for example, when the engine speed becomes equal to or higher than a predetermined speed).
The control signal is output to. Fuel vapor flow rate control valve 72
Receives this control signal, opens a predetermined amount, and adjusts the flow rate of fuel vapor that is about to enter the intake pipe 61 through the purge pipe 71.

Next, the control of the bypass air flow rate control valve 74 will be described. At the time of idling, the air flow rate supplied to the engine 60 is very small, so the main air flow rate control valve 63 is in a state close to the closed state. Therefore, it is difficult to accurately adjust the small air flow rate with the main air flow rate control valve 63 in this state. Therefore, the bypass intake pipe 73 having an inner diameter much smaller than that of the intake pipe 61 is installed in the intake pipe 61.
Is installed in the engine 6 and the flow rate of the air passing therethrough is adjusted by the bypass air flow rate adjusting valve 74, so that the engine 6 can be operated during idling.
The flow rate of air supplied to 0 is controlled to be constant. When the ECU 68 recognizes that the engine is in a predetermined operating state (for example, the state in which the engine speed is equal to or lower than the predetermined speed), the ECU 68 sets a predetermined amount for the bypass air flow rate control valve 74. Output a control signal to open only.

Next, the control of the exhaust gas flow rate control valve 76 will be described. As a method of reducing the NOx concentration in the exhaust gas, there are a method of delaying the ignition timing, a method of using a reduction catalyst, and the like, but EGR (Exhaust gas) that returns a part (5 to 20%) of the exhaust gas to the intake air Reciculation) method is said to be most effective. In this method, part of the exhaust gas is returned to the intake air to lower the combustion temperature of the air-fuel mixture, thereby suppressing the generation of so-called thermal NOx, which is generated by the reaction of oxygen and nitrogen in the air. ing. In order to realize this EGR method, the intake pipe 61 and the exhaust pipe 62 are connected by the exhaust gas recirculation pipe 75, and the exhaust gas flow rate control valve 76 is provided here. The exhaust gas flow rate control valve 76 opens according to a control signal from the ECU 68 by a predetermined amount and controls the flow rate of the exhaust gas returned to the intake pipe 61.

[0042]

According to the present invention, since the rotor of the motor and the valve body are substantially integrated, the vibration of the valve body can be simultaneously suppressed by the bearing that suppresses the vibration of the rotor. The bearing for suppressing the vibration of the valve element can be omitted, and the number of parts can be reduced, the structure can be simplified, and the size and weight can be reduced.

Further, in the present invention, since the flow passage in the valve casing and the space in the motor casing are partitioned by the bearing, even if solid foreign matter is mixed in the fluid flowing in the valve casing, The foreign matter hardly enters the motor casing. Even if foreign matter enters the motor casing through the gap between the bearings, the screw for moving the rotating shaft along with its rotation is located on the opposite side of the bearing from the rotor-side magnetic field generating member. Therefore, foreign matter that has entered the motor casing through the clearance of the bearing hardly reaches the screw. Therefore, according to the present invention, even if the solid foreign matter is mixed in the fluid flowing in the valve casing, the rotating shaft can be surely rotated and moved.

[Brief description of drawings]

FIG. 1 is a sectional view of a flow rate control valve of a first embodiment according to the present invention.

FIG. 2 is an explanatory diagram showing a meshing relationship between a female screw and a male screw.

FIG. 3 is a sectional view of a flow rate control valve according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a flow rate control valve according to a third embodiment of the present invention.

FIG. 5 is a sectional view taken along line AA in FIG.

FIG. 6 is an explanatory diagram showing a configuration around an engine of an embodiment according to the present invention.

[Explanation of symbols]

10, 10b ... Valve, 11, 11b ... Valve casing, 12
... flow path, 16 ... valve seat, 17, 17b ... valve body, 17s ... fitting part, 17t ... engaging convex part, 19 ... guide concave part, 20, 2
0a, 20b ... Stepping motor, 21, 21a ... Motor casing, 25, 25a, 35a ... Female screw, 3
0, 30a, 30b ... Rotor, 31, 31a, 31b ...
Rotating shafts, 32, 32b ... Valve body mounting portion, 32s ... Fitted portion, 33, 33a ... Magnet mounting portion, 34 ... Screw forming portion, 3
4a ... screw hole, 35, 25a ... male screw, 36 ... permanent magnet, 40 ... stator, 41 ... coil, 50 ... plain bearing,
51 ... Rolling bearing, 60 ... Engine, 61 ... Intake pipe, 6
2 ... Exhaust pipe, 63 ... Main air flow control valve, 64 ... Fuel injection valve, 65 ... Fuel tank, 66 ... Canister, 68 ... EC
U, 71 ... Purge pipe, 72 ... Fuel vapor flow rate control valve, 73
… Bypass intake pipe, 74… Bypass air flow control valve, 7
5 ... Exhaust gas recirculation pipe, 76 ... Exhaust gas flow control valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuo Udagawa 2477 Kashima Yatsu, Takada, Katsuta-shi, Ibaraki Prefecture 3 Hitachi Automotive Engineering Co., Ltd. (72) Inventor Yushiro Ejiri 2520 Takata, Katsuta-shi, Ibaraki Prefecture Hitachi, Ltd. Automotive Equipment Division

Claims (8)

[Claims] 1. An electric flow rate control valve for operating a valve body which constitutes a part of a valve by using a motor, wherein the valve closes the valve casing in which a fluid flow passage is formed. A valve body that is movably provided between a closed position and an open position that opens the flow path, and the motor is configured to have one of a coil and a permanent magnet. A ring-shaped stator, the other of the coil and the permanent magnet that are arranged on the inner peripheral side of the ring-shaped stator (hereinafter, referred to as a rotor-side magnetic generation member), and the rotor-side magnetic generation member are fixed. A rotor configured to have a rotating shaft, the stator and the rotor are fixed, the stator is fixed, the rotor is rotatable on the inner peripheral side of the annular stator, and the valve element moves. In the same direction as the direction and more than the amount of movement of the valve body A motor casing movably provided, wherein the rotary shaft extends into the flow passage of the valve casing, and the valve body is provided at one end of the rotary shaft extending into the flow passage. The valve body is attached so that the relative positional relationship with the rotary shaft in the moving direction of the rotary shaft does not change, and the other end of the rotary shaft has a male screw thread around the central axis in the longitudinal direction of the rotary shaft. Or a female screw is formed, and the motor casing is formed with a male screw formed on the other end of the rotating shaft or a female screw or a male screw screwed into the female screw, and the rotating shaft is penetrated. An electrically operated flow rate control valve comprising: a bearing that supports the rotation shaft so as to be rotatable and movable, and that shields a flow passage in the valve casing and a space in the motor casing. 2. The electric flow control valve according to claim 1, wherein the bearing is a slide bearing. 3. Relative to the motor casing,
The electric flow rate according to claim 1 or 2, further comprising an urging member that urges the rotary shaft in a direction from an open position to a closed position of the valve body or from a closed position to an open position. Control valve. 4. A guide concave portion or a guide convex portion extending parallel to a moving direction of the valve body is formed in the valve casing, and the guide concave portion or the guide convex portion of the valve casing is formed in the valve body. An engaging convex portion or an engaging concave portion that can be engaged is formed, and the one end of the rotating shaft is relatively immovable and relatively rotatable in the moving direction of the valve body with respect to the rotating shaft. Is formed, and a fitted portion that fits into the fitting portion of the valve body is formed at the one end of the rotary shaft. The electric flow rate control valve according to 1, 2, or 3. 5. An electric flow rate control valve for operating a valve body which constitutes a part of a valve by using a motor, wherein the valve closes the valve casing in which a fluid flow passage is formed. A valve body that is movably provided between a closed position and an open position that opens the flow path, and the motor is configured to have one of a coil and a permanent magnet. A ring-shaped stator, the other of the coil and the permanent magnet that are arranged on the inner peripheral side of the ring-shaped stator (hereinafter, referred to as a rotor-side magnetic generation member), and the rotor-side magnetic generation member are fixed. A rotor configured to have a rotating shaft, the stator and the rotor are fixed, and the stator is fixed, and the rotor is rotatable on the inner peripheral side of the annular stator and the valve body moves. Move in the same direction as the direction of the valve and move more than the amount of movement of the valve. A capable and provided the motor casing, the rotating shaft extends to said passage of said valve casing, one end of the rotary shaft which extends to within the flow passage,
The valve body is attached so that the relative positional relationship with the rotation shaft in the moving direction of the valve body does not change and rotates relative to the rotation of the rotation shaft, and the valve body and the rotor A male screw or a female screw is formed in a screw shape around the central axis in the longitudinal direction of the rotating shaft at a portion of the rotating shaft other than the portion where the side magnetic field generating member is provided, and in the motor casing, A female screw or a male screw that is screwed into a male screw or a female screw formed on the rotating shaft is formed, and the valve casing is formed with a guide concave portion or a guide convex portion extending parallel to the moving direction of the valve body. An electrically-operated flow control valve, wherein the valve body is formed with an engagement protrusion or an engagement recess that is engageable with the guide recess or the guide protrusion of the valve casing. 6. A flow rate control device for controlling the flow rate of air supplied to an internal combustion engine, wherein the flow rate control device is installed in an intake pipe through which air supplied to the internal combustion engine flows. A flow rate control device comprising: an electric flow rate control valve; and a control unit that controls the drive amount of the motor of the electric flow rate control valve to adjust the position of the valve body. 7. A canister for temporarily storing fuel vapor generated in a fuel tank for storing fuel to be supplied to the internal combustion engine in an intake pipe for supplying air to the internal combustion engine,
A flow rate control device for controlling a flow rate when purging the fuel vapor is installed in a purge pipe that connects the canister and the intake pipe to purge the fuel vapor in the canister into the intake pipe. An electric flow control valve according to claim 1, 2, 3 or 4, and a control means for controlling the drive amount of the motor of the electric flow control valve to adjust the position of the valve body. A flow control device characterized by the above. 8. A flow rate control device for controlling a flow rate of the exhaust gas when returning the exhaust gas exhausted from the internal combustion engine into an intake pipe for supplying air to the internal combustion engine, the exhaust gas from the internal combustion engine The electric flow rate control valve according to claim 1, wherein the electric flow rate control valve is installed in an exhaust gas recirculation pipe that connects the exhaust pipe through which the exhaust gas flows to the intake pipe and sends the exhaust gas to the intake pipe. And a control means for controlling the drive amount of the motor of the electric flow control valve to adjust the position of the valve body.