JP2008032094A - Electric control valve - Google Patents

Abstract

An object of the present invention is to minimize the movement of a rotor in the axial direction and to minimize the increase in the size of an electric motor and the increase in power consumption.
An axial stopper mechanism that restricts axial movement of a rotor 33 that moves in the axial direction with rotation in a direction in which a movable stopper piece 40 moves away from a fixed stopper piece 42 (an end surface 43 of the rotor 33 and the rotor). The stopper end face 44) of the receiving member 36 is incorporated.
[Selection] Figure 1

Description

  The present invention relates to an electric control valve, and more particularly to an electric control valve incorporating a rotation direction stopper mechanism for limiting the rotation of a rotor of an electric motor.

  An electric control valve that converts the rotation of the rotor of the motor into linear motion (axial movement) in the form of a feed screw and increases or decreases the opening degree of the valve port provided in the valve housing by the axial movement of the valve body is known. (For example, Patent Documents 1 and 2).

  Further, in the electric control valve as described above, the rotor is provided as a rotation direction stopper mechanism for limiting the rotation of the rotor, such as a reference point setting stopper for setting the reference point position which is the maximum rotation position in the valve closing direction of the rotor. Some movable stoppers move in the axial direction while rotating due to the rotation of the rotor, thereby abutting against a fixed stopper provided on the valve housing side to limit the rotation of the rotor (for example, Patent Document 1). 3).

In this rotational direction stopper mechanism, the movable side stopper escapes to the axial position where it does not hit the fixed side stopper due to the axial movement of the rotor, so that the rotation of the rotor is not limited to one rotation. Multiple rotations in the valve opening direction from the position. This means that the required amount of full opening (maximum flow rate) can be ensured and the amount of movement of the valve body in the axial direction relative to the unit rotation angle of the rotor can be reduced, and fine flow rate control is possible.
JP 2005-291223 A JP 2006-84012 A Japanese Patent Laid-Open No. 2005-299741

  In the electric control valve incorporating the rotation direction stopper mechanism described above, the rotor must be rotatable because the movable side stopper must escape to the fixed side stopper due to the axial movement of the rotor. In addition, it must be movable axially relative to the valve housing.

  Therefore, regardless of the movement of the rotor in the axial direction, that is, even if the magnetic pole teeth of the stator coil unit fixed to the valve housing are biased by the movement of the rotor in the axial direction, Depending on the amount of axial movement of the rotor, in order to ensure the effective facing length (axial length) of the multi-pole magnetized portion of the rotor and the magnetic pole teeth of the stator coil unit necessary to obtain the required motor torque Thus, it is necessary to increase the axial length of the magnetic pole teeth of the multipolar magnetized portion of the rotor or the stator coil unit.

  This leads to an increase in the size of the electric motor portion of the electric control valve and an increase in power consumption, which hinders downsizing and power saving of the electric control valve.

  The problem to be solved by the present invention is that in an electric control valve incorporating a rotation direction stopper mechanism that restricts the movement of the rotor in the axial direction, the amount of movement of the rotor in the axial direction required for detachment from the rotation direction stopper mechanism is reduced. It is to minimize the size of the electric motor and increase the power consumption to a minimum.

  An electric control valve according to the present invention is provided integrally with a valve housing, a female screw member fixed to the valve housing, a male screw member that is screw-engaged with the female screw member, and the male screw member. A valve body for increasing or decreasing the opening degree of the valve port provided in the valve housing, a can-shaped rotor case fixed to the valve housing, and rotatable in the rotor case and movable in the axial direction And a stator coil unit of the motor mounted on the outer periphery of the rotor case, and the male screw member is driven to rotate by the rotation of the rotor, whereby the valve body is moved in the axial direction. The movable side stopper provided on the rotor moves and moves in the axial direction while rotating by the rotation of the rotor. Further, a rotation direction stopper mechanism that abuts on a fixed side stopper provided on the valve housing side and restricts rotation of the rotor is incorporated, and the rotor and the male screw member are arranged in the axial direction of the rotor. On one end side, the rotor and the male screw member are connected in a torque transmission relationship in which the rotor and the male screw member are relatively displaced in the axial direction by rotation of the rotor, and the other end side in the axial direction of the rotor is connected in the axial direction along with the rotation. An axial direction stopper mechanism for limiting the axial movement of the moving rotor in the direction in which the movable side stopper is separated from the fixed side stopper is incorporated.

  The electric control valve according to the present invention preferably permits axial movement of the rotor necessary for the movable side stopper to be separated from the fixed side stopper, and restricts further movement of the rotor in the axial direction. It is.

  The electric control valve according to the present invention further includes a rotor receiving member that is rotatably supported by the rotor case and supports the other end of the rotor so as to be movable in the axial direction. A stopper end surface forming the axial direction stopper mechanism is formed opposite to the end surface on the other end side of the rotor.

  According to the electric control valve of the present invention, after the rotor has moved in the axial direction by the distance that the movable side stopper is separated from the fixed side stopper, the axial stopper mechanism is used to move the movable side stopper away from the fixed side stopper. The axial movement of the rotor in rotation is limited, and the male screw member is displaced in the axial direction relative to the rotor in further rotation of the rotor in the same direction.

  Thereby, the movement of the rotor in the axial direction can be minimized, and the increase in the size of the electric motor portion and the increase in power consumption can be minimized.

  One embodiment of an electric control valve according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the electric control valve of this embodiment includes a metal cup-shaped valve housing 11 made of a press-formed product. The valve housing 11 is fixedly mounted by brazing or the like with a lateral joint 12 on the side and a lower joint 13 on the lower bottom. The valve housing 11 cooperates with a female screw member 18 described later to define a valve chamber 14 in a cylindrical space.

  A valve seat member 16 formed with a valve port 15 is fixedly mounted to the lower bottom portion of the valve housing 11 by brazing or the like. The valve port 15 is located at the same position as the center position of the valve chamber 14 and connects the valve chamber 14 and the lower joint 13 in communication. The lateral joint 12 communicates directly with the valve chamber 14.

  A female screw member 18 is fixed to the upper portion of the valve housing 11 at the center position of the valve chamber 14 by a metal fixing bracket 17 made of a press-formed product.

  The female screw member 18 is formed with a female screw 19 that penetrates the central portion of the female screw member 18 in the axial direction (vertical direction in FIG. 1).

  A male screw 21 of a valve rod-like male screw member 20 is threadedly engaged with the female screw 19. A needle valve body 22 is integrally formed at one end (lower end) of the male screw member 20. The needle valve body 22 is in the valve chamber 14 and increases or decreases the opening degree of the valve port 15 by moving in the axial direction. Thereby, flow control of the fluid flowing between the horizontal joint 12 and the lower joint 13 is performed.

  A metal rotor case 31 of the stepping motor 30 is fixedly attached to the upper portion of the valve housing 11 by welding or the like. The rotor case 31 has a can shape having a cylindrical portion 31A and a dome portion 31B, and a rotor rotation receiving recess 31C is formed at the center of the dome portion 31B.

  A rotor 33 of the stepping motor 30 is disposed inside the cylindrical portion 31 </ b> A of the rotor case 31, that is, in the rotor chamber 32 so as to be rotatable and movable in the axial direction. The rotor 33 has a bottomed cup shape on the valve housing 11 side, and the outer peripheral portion 33A is multipolarized.

  A stator coil unit 35 of the stepping motor 30 is fixedly attached to the outside of the cylindrical portion 31A of the rotor case 31. Although not shown in detail, the stator coil unit 35 has a general structure having a coil, a large number of magnetic pole teeth, and the like. By applying a pulse current to the coils of the stator coil unit 35, the rotor 33 rotates with a rotation angle corresponding to the number of pulses.

  A substantially H-shaped (see FIG. 2) torque transmission shape portion 34 is formed on the inner side of the rotor 33 within a predetermined axial length range from the bottom surface side. The other end (upper end) of the male screw member 20 passes through a through hole 33 </ b> B formed in the center of the bottom of the rotor 33 and protrudes inside the rotor 33. A torque transmission plate 23 having a shape that complements the torque transmission shape portion 34 (see FIG. 2) is fixedly attached to the upper end of the male screw member 20. The torque transmission plate 23 is engaged with the torque transmission shape portion 34 of the rotor 33 so as to be displaceable in the axial direction. Thereby, the rotor 33 and the male screw member 20 are connected in a torque transmission relationship in which the rotor 33 and the male screw member 20 are relatively displaced in the axial direction by the rotation of the rotor 33 on one end side (lower end side) of the rotor 33. .

  Thereby, the rotation of the rotor 33 is transmitted to the male screw member 20, and the male screw member 20 is integrated with the male screw member 20 as the male screw member 20 rotates by screw engagement between the male screw 21 of the male screw member 20 and the female screw 19 of the female screw member 18. The needle valve body 22 moves in the axial direction.

  A rotor receiving member 36 is provided on the dome portion 31 </ b> B side in the rotor case 31. The rotor receiving member 36 is rotatably engaged with the rotor rotation receiving recess 31C at the center of the dome portion 31B with the pivot shaft portion 36A, and is rotatably supported by the rotor case 31 by the engagement. The rotor receiving member 36 has a cylindrical portion 36B formed on the side opposite to the pivot shaft portion 36A and is fitted to the inner cylinder portion 33C of the rotor 33 so as to be movable in the axial direction. Thus, the rotor receiving member 36 supports the other end side (upper end side) of the rotor 33 so as to be movable in the axial direction. The rotor receiving member 36 is formed with a pressure equalizing hole 37 for equalizing the pressure in the entire rotor case 31 and the rotor 33.

  A compression coil spring 38 is provided between the torque transmission plate 23 and the rotor receiving member 36. The compression coil spring 38 acts between the torque transmission plate 23 and the rotor receiving member 36 to constantly urge the rotor receiving member 36 toward the dome portion 31B (upper side). As a result, the engagement between the pivot shaft portion 36A and the rotor rotation receiving recess 31C is maintained.

  A compression coil spring 39 is provided between the rotor 33 and the female screw member 18. The compression coil spring 39 acts between the rotor 33 and the female screw member 18 to always urge the rotor 33 toward the dome portion 31B (upper side).

  The winding end of the compression coil spring 39 on the rotor 33 side engages with a recess 33 </ b> D formed on the lower bottom portion of the rotor 33 to form a movable side stopper piece 40 provided on the rotor 33. A fixed-side stopper member 41 is fixedly mounted on the valve housing 11 by a fixing bracket 17. A fixed-side stopper piece 42 is formed upright on the fixed-side stopper member 41.

  The movable-side stopper piece 40 abuts on the fixed-side stopper piece 42 by moving in the axial direction while moving together with the rotor 33 by the rotation of the rotor 33 in the valve closing direction, thereby moving the rotor 33 in the valve closing direction. Limit rotation.

  The movable side stopper piece 40 and the fixed side stopper piece 42 constitute a rotation direction stopper mechanism, and this stopper serves as a reference point setting stopper for setting a reference point position which is the maximum rotation position of the rotor 33 in the valve closing direction.

  The movable stopper piece 40 moves in the axial direction while rotating together with the rotor 33 by the rotation within one rotation of the valve opening direction of the rotor 33 (upward movement), so that the movable stopper piece 40 does not hit the fixed stopper piece 42. It is supposed to escape. Thus, the rotation of the rotor 33 is not limited to one rotation, and the rotor 33 can make multiple rotations in the valve opening direction from the base point position.

  In this embodiment, the movable side stopper piece 40 of the rotational direction stopper mechanism is configured by engaging the winding end of the compression coil spring 39 on the rotor 33 side with a recess 33D formed in the lower bottom portion of the rotor 33. However, the movable-side stopper element of the rotational direction stopper mechanism may be directly configured by a protruding piece 46 integrally formed on the lower bottom portion of the rotor 33 as shown in FIGS. .

  The rotor receiving member 36 is formed with a stopper end surface 44 that faces the end surface 43 on the other end side (upper end side) of the rotor 33 by a flange portion 36C. The end face 43 of the rotor 33 and the stopper end face 44 face each other with an axial gap 45 in the state of FIG. 1 where the rotor 33 is located at the base position (0 pulse position), and the movable stopper piece 40 is fixed. The axial movement (upward movement) of the rotor 33 in the rotation of the rotor 33 away from the side stopper piece 42 (rotation in the valve opening direction) is limited to the axial length of the axial gap 45. Thereby, an axial direction stopper mechanism is constituted.

  The axial length (initial value) of the axial gap 45 of the axial stopper mechanism is set according to the amount of axial movement with a margin necessary for the movable side stopper piece 40 to be separated from the fixed side stopper piece 42. ing. Thus, the axial stopper mechanism allows the axial movement (upward movement) of the rotor 33 only for the axial movement with a margin necessary for the movable stopper piece 40 to be separated from the fixed stopper piece 42, and beyond. The movement (upward movement) of the rotor 33 in the axial direction is limited.

  Next, the operation of the electric control valve according to this embodiment will be described with reference to FIGS. 1 and 3 to 5.

  In the base point position state shown in FIG. 1 (maximum valve closed state = 0 pulse position), the movable side stopper piece 40 contacts the fixed side stopper piece 42 and the rotor 33 rotates further in the valve closing direction. Stopped. In this base point position state, the end surface 43 of the rotor 33 and the stopper end surface 44 of the rotor receiving member 36 face each other with the initial value of the axial gap 45.

  When the rotor 33 makes one rotation in the valve opening direction from the base position state, the movable side stopper piece 40 rotates in the axial direction while rotating together with the rotor 33 as shown in FIG. By moving (upward movement), it is located at a position where it has escaped in the axial direction to a position where it does not hit the fixed stopper piece 42.

  The axial movement of the rotor 33 at this time is performed by displacing the rotor receiving member 36 in the axial direction, and the end face 43 of the rotor 33 and the stopper end face 44 of the rotor receiving member 36 are moved along with the axial movement. The axial length of the axial gap 45 is reduced.

  As a result, when the rotor 33 further rotates in the valve opening direction, the end face 43 of the rotor 33 contacts the stopper end face 44 of the rotor receiving member 36 as shown in FIG. In contact therewith, further movement of the rotor 33 in the axial direction (upward movement) is restricted. That is, the rotor 33 can no longer move upward.

  Until this state (a state in which the end surface 43 of the rotor 33 is in contact with the stopper end surface 44 of the rotor receiving member 36), in the engaging portion between the torque transmission plate 23 of the male screw member 20 and the torque transmission shape portion 34 of the rotor 33. No relative axial displacement occurs, torque is transmitted from the rotor 33 to the male screw member 20, and the male screw member 20 and the needle valve body 22 move integrally with the rotor 33 in the axial direction by the rotation of the male screw member 20.

  As a result, when the rotor 33 rotates in the valve opening direction, as shown in FIG. 5, as the maximum valve opened state, the upward movement of the rotor 33 is stopped. The male screw member 20 and the needle valve element 22 move in the axial direction (upward movement) while causing a relative axial displacement at the engagement portion between the torque transmission plate 23 of the male screw member 20 and the torque transmission shape portion 34 of the rotor 33. To do.

  As described above, after the rotor 33 moves in the axial direction so that the movable stopper piece 40 is separated from the fixed stopper piece 42, the end surface 43 of the rotor 33 comes into contact with the stopper end surface 44 of the rotor receiving member 36 and the movable stopper The movement of the rotor 33 in the axial direction in the rotation of the rotor 33 in the valve opening direction in which the piece 40 is separated from the fixed stopper piece 42 is limited. In the further rotation of the rotor 33 in the same direction, the male screw member 20 is moved relative to the rotor 33. Since the rotor 33 is displaced relatively in the axial direction, the movement of the rotor 33 in the axial direction is minimized to the minimum necessary for the movable side stopper piece 40 to be separated from the fixed side stopper piece 42.

  Thereby, compared with the case where the rotor 33 moves in the axial direction at all between the maximum valve closed position and the maximum valve open position, the multipolar magnetized portion of the rotor 33 necessary for obtaining the required motor torque. Alternatively, the axial length of the magnetic pole teeth of the stator coil unit 35 can be shortened, and the size of the stepping motor portion and the increase in power consumption can be minimized.

  Further, since the rotor 33 is supported by the rotor case 31 by the rotor receiving member 36, the rotor case 31 can be controlled only by controlling the radial clearance between the cylindrical portion 36B of the rotor receiving member 36 and the inner cylindrical portion 33C of the rotor 33. And the rotor 33 are highly concentric.

  Thereby, the radial clearance between the rotor case 31 and the rotor 33 can be reduced, and accordingly, the distance between the rotor 33 and the coil inner diameter of the stator coil unit 35 can be reduced. As a result, the motor torque increases, and the stepping motor 30 can be reduced in size and power consumption can be reduced.

  Further, since the rotor receiving member 36 is rotatably engaged with the rotation receiving recess 31C of the rotor case 31 with the pivot shaft portion 36A, the frictional resistance of this portion can be reduced and the friction loss of the stepping motor 30 can be reduced. Is planned. This also makes it possible to reduce the size of the stepping motor 30 and reduce the power consumption.

It is sectional drawing which shows the base point position state (maximum valve closed state) of one Embodiment of the electrically driven control valve by this invention. It is sectional drawing along line AA of FIG. It is sectional drawing which shows the 1st intermediate opening position state of one Embodiment of the electrically driven control valve by this invention. It is sectional drawing which shows the 2nd intermediate opening position state of one Embodiment of the electrically driven control valve by this invention. It is sectional drawing which shows the maximum valve open state of one Embodiment of the electrically driven control valve by this invention. It is sectional drawing which shows other embodiment of the electrically driven control valve by this invention. It is an expanded sectional view of the important section of the electric control valve by other embodiments.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Valve housing 12 Horizontal joint 13 Lower joint 14 Valve chamber 15 Valve port 16 Valve seat member 17 Fixing metal fitting 18 Female thread member 19 Female thread 20 Male thread member 21 Male thread 22 Needle valve element 23 Torque transmission plate 30 Stepping motor 31 Rotor case 31A Cylindrical part 31B Dome part 31C Rotation receiving recessed part 32 Rotor chamber 33 Rotor 33A Outer peripheral part 33B Through hole 33C Inner cylinder part 33D Recessed part 34 Torque transmission shape part 35 Stator coil unit 36 Rotor receiving member 36A Pipet shaft part 36B Column part 36C Flange part 37 Pressure equalizing hole 38, 39 Compression coil spring 40 Movable stopper piece 41 Fixed stopper member 42 Fixed stopper piece 43 End face 44 Stopper face 45 Axial gap 46 Projection piece

Claims (3)

A valve housing, a female screw member fixed to the valve housing, a male screw member that is screw-engaged with the female screw member, and a valve that is provided integrally with the male screw member and is provided in the valve housing by axial movement. A valve body that increases or decreases the opening of the port; a can-shaped rotor case fixed to the valve housing; and a rotor of an electric motor that is rotatably disposed in the rotor case and movable in the axial direction. With the stator coil unit of the electric motor mounted on the outer periphery of the rotor case,
When the male screw member is driven to rotate by the rotation of the rotor, the valve body moves in the axial direction,
A rotation direction in which the movable stopper provided on the rotor moves in the axial direction while rotating by the rotation of the rotor, thereby contacting the fixed stopper provided on the valve housing side and restricting the rotation of the rotor A stopper mechanism is incorporated,
The rotor and the male screw member are connected in a torque transmission relationship in which the rotor and the male screw member are relatively displaced in the axial direction by rotation of the rotor on one end side in the axial direction of the rotor,
On the other end side in the axial direction of the rotor, an axial direction stopper mechanism that restricts the axial movement of the rotor that moves in the axial direction with rotation in a direction in which the movable side stopper moves away from the fixed side stopper. Electric control valve with built-in.   The axial direction stopper mechanism allows the axial movement of the rotor necessary for the movable side stopper to be separated from the fixed side stopper, and restricts further axial movement of the rotor. The electric control valve described.   A rotor receiving member that is rotatably supported by the rotor case and supports the other end of the rotor so as to be movable in an axial direction; the rotor receiving member is opposed to an end surface of the other end of the rotor; The electric control valve according to claim 1, wherein a stopper end surface forming the axial direction stopper mechanism is formed.

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