JP2006010004A - Electric control valve - Google Patents

Abstract

[PROBLEMS] To reliably prevent a valve body from biting into a valve seat and a lead screw mechanism from falling into a screw lock state without causing a significant increase in the number of parts, and stepping based on a valve closing position. Make sure that the motor can be initialized accurately and that there is no need to set the valve opening pulse.
A female screw member 21 is provided in a valve housing 11 so as to be movable in an axial direction in a rotation-stopped state, a valve body 17 is connected to the female screw member 21, and a male screw member 23 screw-engaged with the female screw member 21 is stepped. A drive-side clutch member 40 that is rotationally driven by the rotor 33 of the motor 30 and is connected to the rotor 33 so as to be movable in the axial direction in relation to torque transmission, and a drive-side clutch member 40 that is fixedly connected to the male screw member 23. An opposing driven clutch member 43 is provided, and the driving clutch member 40 and the driven clutch member 43 constitute a meshing clutch that is always meshed in rotation in the valve opening direction.
[Selection] Figure 1

Description

  The present invention relates to an electric control valve, and more particularly to a linear type electric control valve in which a valve element linearly moves in a valve lift direction (axial direction) by a feed screw mechanism to open and close the valve.

  The valve device for controlling the flow rate of various devices includes a feed screw mechanism by screw engagement between a male screw member and a female screw member. The feed screw mechanism is driven to rotate by a rotor of a stepping motor, and the rotary motion is controlled by the feed screw mechanism. There is a linear type electric control valve that converts the linear motion in the lift direction and moves the valve body in the lift direction by the linear motion (for example, Patent Documents 1 and 2).

  In such an electric control valve, since the valve body is seated on the valve seat portion on the valve housing side, the valve is closed (fully closed). Therefore, even if the valve body is seated on the valve seat portion, the stepping is still performed. When the valve is driven to close by the motor, the valve element is strongly biting into the valve seat, and the male screw member and female screw member of the feed screw mechanism are strongly tightened, resulting in a screw lock state. For this purpose, there is provided an electric control valve provided with a multi-rotation contact type stopper mechanism for limiting the rotation of the stepping motor rotor in the valve closing direction so as to perform zero pulse setting (initialization) of the stepping motor in the valve closed state. Have been proposed (for example, Patent Documents 1 and 2).

  With such a multi-rotation contact type stopper mechanism that restricts the rotation of the rotor of the stepping motor in the valve closing direction, the valve element strongly bites into the valve seat, or the male screw member and female screw of the feed screw mechanism Although it is possible to prevent the member from being tightly tightened and falling into a screw lock state, it is necessary to incorporate a multi-rotation contact type stopper mechanism with a large number of parts into the stepping motor, which greatly increases the number of parts. I can't avoid it.

  In addition, due to component errors and assembly errors, it is inevitable that variations occur between the rotor rotation position where the valve element is seated on the valve seat and the rotor rotation stop position due to the stopper mechanism. ) Even after the rotor reaches the rotational position where the valve element is seated on the valve seat so that the state can be obtained, it is necessary to set the 0 pulse by applying a pulse signal for driving in the valve closing direction to the stepping motor.

  Electric control valve that limits the relative axial movement (stroke) between the male screw member and female screw member of the feed screw mechanism to a contact type and sets 0 pulse (initialization) of the stepping motor in the valve open state (For example, Patent Document 3).

  In this electric control valve, there is no need to incorporate a multi-rotation contact type stopper mechanism into the stepping motor, and the number of parts does not increase, but depending on the setting, the male screw member and female screw member of the feed screw mechanism It is impossible to avoid falling into a screw lock state that can be tightened strongly, and because the stepping motor is initialized based on the valve open position, the valve closed state is accurately affected by the effects of component errors and assembly errors. It is difficult to control settings.

  In addition, an electrically operated control valve is provided in the middle of the torque transmission path between the stepping motor and the feed screw mechanism to provide an elastically actuated clutch that acts like a torque limiter and prevents the valve element from biting into the valve seat. (For example, Patent Document 4).

However, with this electric control valve, it is difficult to set the limit transmission torque of the elastically operated clutch, and if this is low, normal valve opening / closing operation will not be performed due to excessive idling of the elastically operated clutch, and conversely the limit transmission torque of If the set value is high, it is not possible to properly prevent the valve body from biting into the valve seat and the feed screw mechanism from falling into the screw lock state. There is a possibility that the degree of biting will appear as a variation as it is, and the operation performance becomes unstable.
Japanese Patent No. 2615021 JP 2003-148644 A JP 2000-346225 A JP 2001-271156 A

  The problem to be solved by the present invention is a linear type electric control valve in which a valve element linearly moves in a valve lift direction by a feed screw mechanism to open and close the valve element without causing a significant increase in the number of parts. Prevents the valve seat part from digging into the valve seat and the male and female screw members of the feed screw mechanism are tightly tightened, ensuring that the screw lock state is avoided, and that the stepping motor is initialized accurately based on the valve closing position. In addition, it is possible to reliably close the valve.

  In the electric control valve according to the present invention, the male screw member is provided in the valve housing so that the female screw member is movable in the axial direction in a rotation-stopped state, the valve element is connected to the female screw member, and the male screw member engaged with the female screw member is screwed. In an electric control valve that is driven to rotate by a rotor of an electric motor and closes when the valve element is seated on a valve seat on the valve housing side, the drive is connected to the rotor so as to be movable in the axial direction in relation to torque transmission A side clutch member, a driven clutch member fixedly connected to the male screw member and opposed to the drive side clutch member, and a clutch spring for biasing the drive side clutch member in an engagement direction with the driven side clutch member The drive side clutch member and the driven side clutch member are always engaged in rotation in the valve opening direction. Constitute the pitch.

  In the electric control valve according to the present invention, preferably, the drive side clutch member and the driven side clutch member have a serrated clutch pawl having a steep slope and a gentle slope, and are engaged with each other on the steep slope side in the rotation in the valve opening direction. A meshing clutch that achieves constant meshing and meshes with each other on the gentle slope side in rotation in the valve closing direction is configured.

  The electric control valve according to the present invention preferably further includes a clutch spring that urges the driving side clutch member in an engagement direction with the driven side clutch member.

  The electric control valve according to the present invention preferably further includes a valve closing spring for urging the male screw member in the valve closing direction.

  In the electric control valve according to the present invention, when the valve body is not seated on the valve seat portion, the drive side clutch member and the driven side clutch member are in a strong meshing engagement state, so that the rotation in the valve opening direction is performed. With the constant meshing, the rotation of the rotor in either the valve opening direction or the valve closing direction is transmitted from the driving side clutch member to the driven side clutch member and the male screw member, and the male screw member rotates. The female screw member that is screw-engaged with the male screw member moves in the axial direction in a rotation-stopped state, and the valve body is opened and closed.

  In the valve closing drive, when the valve element is seated on the valve seat portion, the axial movement of the female screw member stops, and in this state, if the rotor further rotates in the valve closing direction, the male screw member moves in the axial direction. The driven clutch member moves away from the driving clutch member, and the meshing state between the driving clutch member and the driven clutch member is loosened. When the meshing state is loosened, the torque in the valve closing direction is not transmitted from the driving side clutch member to the driven side clutch member, and even if the rotor is continuously driven to rotate in the valve closing direction, the rotor and the driving side clutch member Runs idle with respect to the driven clutch member, and the driven clutch member does not rotate.

  As a result, the valve body strongly bites into the valve seat, and the male screw member and female screw member of the feed screw mechanism are strongly tightened, and it is reliably prevented from falling into the screw lock state. The stepping motor can be initialized accurately and the valve can be closed reliably.

  The valve opening drive from the state where the clutch engagement is loose is a state where the meshing state of the drive side clutch member and the driven side clutch member is loosened because the meshing clutch is always meshed for rotation in the valve opening direction. However, the rotation of the rotor in the valve opening direction is transmitted from the drive side clutch member to the driven side clutch member. As a result, the male screw member moves in the axial direction in the opposite direction to that when the valve is closed, the driven side clutch member and the driving side clutch member return to the original strongly engaged engagement state, and the valve opening direction of the rotor Is transmitted from the drive-side clutch member to the driven-side clutch member and the male screw member, the male screw member rotates, and the female screw member that is screw-engaged with the male screw member moves in the axial direction in a rotation-stopped state. The body moves open.

  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 has a valve housing 11. The valve housing 11 is formed with a valve chamber 12, a first inlet / outlet port 13, a second inlet / outlet port 14, and a valve port 16 that defines a valve seat portion 15. The valve port 16 is on the bottom side of the valve chamber 12.

  A needle valve (valve element) 17 is provided in the valve chamber 12. The needle valve 17 moves in the axial direction (vertical direction) to quantitatively increase or decrease the opening degree of the valve port 16, and by seating on the valve seat portion 15 by the downward movement, the valve port 16 is closed and the valve is closed. (Fully closed).

  A non-rotating guide sleeve 19 having a spline hole 18 is fixedly attached to the valve housing 11. As shown in FIG. 4, in the spline hole 18 of the anti-rotation guide sleeve 19, a female screw member 21 having a spline shaft portion 20 that is spline engaged with the spline hole 18 is in the axial direction in a rotation-stopped state due to the spline engagement. Is movably engaged. A needle valve 17 is fixedly attached to the lower end portion of the female screw member 21. That is, the female screw member 21 supports the needle valve 17 in a fixed state. The female screw member 21 is a screw member for a feed screw mechanism, and a female screw 22 is formed at the center.

  As shown in FIG. 1, a can-shaped rotor case 31 of a stepping motor 30 is airtightly attached to the upper portion of the valve housing 11 by welding or the like with a lower lid member 32. In the rotor case 31, a rotor 33 having a multi-pole magnetized outer peripheral surface portion 34 is provided to be rotatable around its own rotation center. A ring-shaped stator coil unit 35 is attached to the outside of the rotor case 31.

  The rotor 33 has a hub portion 36 at an intermediate portion in the axial direction thereof, and a drive side clutch engagement hole having a key groove portion 37 as shown in FIG. 6 below the hub portion 36. 38. A drive side clutch member 40 having a key portion 39 that engages with the key groove portion 37 and the sliding key is inserted into the drive side clutch engagement hole 38. That is, the rotor 33 is connected to the drive side clutch engagement hole 38 so that the drive side clutch member 40 can move in the axial direction in relation to torque transmission. As shown in FIG. 5, a plurality of clutch claws 41 are formed in an annular arrangement on the upper surface 40 </ b> A of the drive side clutch member 40.

  As shown in FIG. 1, the rotor 33 has a driven-side clutch engagement hole 42 in the hub portion 36. A driven clutch member 43 is rotatably inserted into the driven clutch engagement hole 42. As shown in FIG. 5, a plurality of clutch pawls 44 that can be engaged with and engaged with the clutch pawl 41 are formed on the lower bottom surface of the driven side clutch member 43 in an annular arrangement.

  As shown in FIG. 5, the clutch pawl 41 of the drive side clutch member 40 includes a steep slope (vertical surface) 41 </ b> A for continuous engagement extending perpendicularly to the upper surface 40 </ b> A of the drive side clutch member 40, and an upper surface. It is formed in a sawtooth shape by a gentle slope 41B extending with a gentle inclination with respect to 40A. Similarly, the clutch pawl 44 of the driven-side clutch member 43 also has a steep slope (vertical surface) 44A for normal engagement extending vertically from the lower bottom surface of the driven-side clutch member 43 and the lower bottom surface of the driven-side clutch member 43. And a gentle inclined surface 44B extending in a slanting manner and having a sawtooth shape.

  The steep slope 41A of the clutch pawl 41 and the steep slope 44A of the clutch pawl 44 are vertical surfaces. However, these may be steep slopes close to the vertical on the precondition that meshing is always achieved. .

  As shown in FIGS. 1 and 2, the drive-side clutch member 40 moves upward when the upper surface 40 </ b> A of the drive-side clutch member 40 contacts the upper end surface 38 </ b> A of the drive-side clutch engagement hole 38. Is regulated. The driven-side clutch member 43 is restricted from moving downward by the downwardly-facing step end surface 43A of the driven-side clutch member 43 coming into contact with the upward stepped end surface 36A of the hub portion 36.

  As shown in FIG. 1, when both the clutch claws 41 and 44 receive the driving side clutch member 40 and the driven side clutch member 43 in the driving side clutch engaging hole 38 and the driven side clutch engaging hole 42, respectively. As shown in FIG. 5, the clutch pawls 41 and 44 are opposed to each other and are arranged in opposite directions.

  As shown in FIG. 1, a male screw 24 of a male screw member 23 for a feed screw mechanism is screw-engaged with the female screw 22 of the female screw member 21. The upper portion 23A of the male screw member 23 passes through a bearing hole 45 formed in the lower lid member 32 so as to be rotatable and movable in the axial direction, and protrudes into the rotor case 31. The upper portion 23A of the male screw member 23 further penetrates a through hole 46 formed in the center of the spring receiving member 48 and the driving side clutch member 40, which will be described later, in a rotatable and axially movable state, and a driven side clutch member. In a state of being fitted into the center hole 47 of 43, the driven clutch member 43 is fixedly connected.

  A spring receiving member 48 is loosely fitted in a portion of the upper portion 23 </ b> A of the male screw member 23 located between the drive side clutch member 40 and the lower lid member 32, and the spring receiving member 48 and the lower lid member 32. A clutch spring that urges the drive-side clutch member 40 upward, in other words, urges the clutch pawl 41 of the drive-side clutch member 40 in the direction of engagement with the clutch pawl 44 of the driven-side clutch member 43. 49 is provided.

  A concave portion 50 is formed at the center of the ceiling portion 31A in the rotor case 31, and the convex portion 52 of the upper spring receiving member 51 is rotatably engaged with the concave portion 50. A lower spring receiving member 53 is in contact with the upper center portion of the driven side clutch member 43 (the upper end surface 23B of the male screw member 23) in a pivot engagement state. Between the upper spring receiving member 51 and the lower spring receiving member 53, a valve closing spring 54 for urging the driven clutch member 43 and the male screw member 23 downward, that is, in the valve closing direction is provided.

  Further, the upper spring receiving member 51 is formed with a flange portion 55. An upside down cup-shaped support member 56 is fixed to the rotor 33, and an upper end portion 57 of the support member 56 is rotatably supported by the flange portion 55.

  The operation of the electric control valve configured as described above will be described. In the valve open state in which the needle valve 17 is not seated on the valve seat portion 15, the upper surface 40 </ b> A of the drive side clutch member 40 is driven by the spring force of the clutch spring 49 as shown in FIG. 2. The driven side clutch member 43 is in a lower limit position where the step end surface 43A contacts the step end surface 36A of the hub portion 36 by the spring force of the valve closing spring 54. .

  Under this state, as shown in FIG. 7, the gentle slope 41B of the clutch pawl 41 of the driving side clutch member 40 and the gentle slope 44B of the clutch pawl 44 of the driven side clutch member 43 are in contact with each other, and The steep slope 41A of the clutch pawl 41 and the steep slope 44A of the clutch pawl 44 come into full contact with each other, and the drive side clutch member 40 and the driven side clutch member 43 are in a strong (deep) meshing engagement state.

  In this state, the rotational torque in the valve opening direction is transmitted from the drive-side clutch member 40 to the driven-side clutch member 43 by constant engagement by engagement between the steep slope 41A of the clutch pawl 41 and the steep slope 44A of the clutch pawl 44. The rotational torque in the valve closing direction opposite to this is caused by the full contact between the gentle slope 41B of the clutch pawl 41 and the gentle slope 44B of the clutch pawl 44, that is, by contact with a large contact area, from the driven clutch member 40. It is transmitted to the clutch member 43. In this state, the step end surface 43A of the driven clutch member 43 is frictionally engaged with the step end surface 36A of the hub portion 36 by the spring force of the valve closing spring 54, which contributes to torque transmission.

  Thereby, in the valve open state where the needle valve 17 is not seated on the valve seat portion 15, the rotation of the rotor 33 in either the valve opening direction or the valve closing direction is driven by the driven side clutch member 43 from the driving side clutch member 40. The male screw member 23 is transmitted to the male screw member 23, and the male screw member 23 rotates forward and backward. The female screw member 21 screw-engaged with the male screw member 23 moves in the axial direction in a rotationally stopped state with respect to the valve housing 11 as the male screw member 23 rotates forward and backward, and the needle valve 17 integrated therewith opens and closes. It moves (up and down) and the valve opening is determined.

  In this state, that is, in a state where the needle valve 17 is not seated on the valve seat portion 15, the valve closing spring 54 drives the entire needle valve 17, the female screw member 21, the male screw member 23, and the driven clutch member 43. The step end surface 43A of the side clutch member 43 is urged downward to a position where it contacts the step end surface 36A of the hub portion 36, and the needle valve 17, the internal thread member 21, the external thread member 23, and the driven side clutch member 43 are prevented from being lifted. .

  Under this state, since the spring force of the valve closing spring 54 does not act as a thrust force on the screw engaging portion between the female screw member 21 and the male screw member 23, the screw engagement between the female screw member 21 and the male screw member 23 is performed. The wear of the part and the driving load of the stepping motor 30 are reduced.

  When the needle valve 17 is seated on the valve seat 15 in the valve closing process, the axial movement (downward movement) of the female screw member 21 stops. In this state, when the rotor 33 further rotates in the valve closing direction, the male screw member 23 moves against the female screw member 21 against the spring force of the valve closing spring 54 and moves in the axial direction (upward movement). It will be.

  As a result, as shown in FIG. 3, the driven-side clutch member 43 moves (moves upward) away from the drive-side clutch member 40, and as shown in FIGS. 8 (a) and 8 (b). Furthermore, the meshing state of the clutch pawl 41 of the drive side clutch member 40 and the clutch pawl 44 of the driven side clutch member 43 is loosened (shallow).

  Thus, when the meshing state of the clutch pawls 41 and 44 becomes shallower, when the drive side clutch member 40 rotates in the valve closing direction, as shown in FIG. And the gentle slope 44B of the clutch pawl 44 is smaller than that in the deep meshing state shown in FIG. 7, and the contact side clutch member 43 is driven by the drive side clutch member 40 in the contact by this contact area. Torque transmission is not performed, and the gentle slope 41B of the clutch pawl 41 slides on the gentle slope 44B of the clutch pawl 44 against the spring force of the clutch spring 49, so that the drive side clutch member 40 moves relative to the driven side clutch member 43. As a result, the upper surface 40A of the drive side clutch member 40 is separated from the upper end surface 38A of the drive side clutch engagement hole 38.

  As a result, the needle valve 17 does not move any further, and the needle valve 17 bites into the valve seat 15, or the male screw member 23 and the female screw member 21 are strongly tightened so that the screw is locked. It is definitely prevented from falling. Furthermore, the spring force of the valve closing spring 54 is received by the driven side clutch member 43 and the male screw member 23, and the valve closed state of the needle valve 17 is securely held via the threaded portions of the male screw member 23 and the female screw member 21. be able to.

  Further, the idling on the rotor 33 side can accurately initialize the stepping motor 30 based on the valve closing position. This eliminates the need for incorporating a multi-rotation contact type stopper mechanism having a large number of parts.

  As described above, the valve opening drive from the state where the meshing state of the clutch pawls 41 and 44 is shallow, as shown in FIG. 8A, the steep slope 41A of the clutch pawl 41 and the clutch pawl 44 When the rotation in the valve opening direction is transmitted from the driving side clutch member 40 to the driven side clutch member 43 by the constant meshing by the engagement of the steep slopes 44A, first, the male screw member 23 is axially directed in the direction opposite to that when the valve is closed. It will move in the direction (downward movement).

  As a result, the engaged state of the driven side clutch member 43 and the driving side clutch member 40 returns to the original state, and the rotor 33 continues to rotate in the valve opening direction, so that the rotational torque in the valve opening direction is greater than that of the driving side clutch member 40. The male screw member 23 is transmitted to the driven clutch member 43 and the male screw member 23, the male screw member 23 rotates in the valve opening direction, and the female screw member 21 screw-engaged with the male screw member 23 moves upward in the axial direction in a rotation-stopped state. Accordingly, as shown in FIG. 2, the needle valve 17 moves to open.

  The upper spring receiving member 51, the lower spring receiving member 53, the female screw member 21, the spring receiving member 48, and the like are made of a bearing material such as a highly slippery resin or sintered metal having a low friction coefficient, thereby reducing the friction. The resistance can reduce noise.

It is a longitudinal section showing one embodiment of an electric control valve by this invention. It is a longitudinal cross-sectional view which shows the fully open state of the electrically-driven control valve by one Embodiment. It is a longitudinal cross-sectional view which shows the valve closing state of the electric control valve by one Embodiment. It is a perspective view which shows the internal thread member and rotation prevention guide sleeve of the electrically-driven control valve by one Embodiment. It is a perspective view which shows the driven side clutch member and drive side clutch member of the electric control valve by one Embodiment. It is a perspective view which shows the rotor and drive side clutch member of the electric control valve by one Embodiment. It is explanatory drawing which shows the deep clutch meshing state of the electric control valve by one Embodiment. (A) is explanatory drawing which shows valve opening direction drive in the shallow clutch meshing state of the electric control valve by one Embodiment, (b) is explanatory drawing which similarly shows the valve closing direction drive.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Valve housing 12 Valve chamber 13 1st inlet / outlet port 14 2nd inlet / outlet port 15 Valve seat part 16 Valve port 17 Needle valve 19 Anti-rotation guide sleeve 21 Female screw member 22 Female screw 23 Male screw member 24 Male screw 30 Stepping motor 31 Rotor Case 33 Rotor 35 Stator coil unit 40 Drive side clutch member 41 Clutch pawl 43 Driven side clutch member 44 Clutch pawl 49 Clutch spring 54 Valve closing spring

Claims (4)

A female screw member is provided in the valve housing so as to be movable in the axial direction in a rotation-stopped state, a valve body is connected to the female screw member, and a male screw member screw-engaged with the female screw member is driven to rotate by a rotor of an electric motor. In the electric control valve which closes the valve by seating the valve body on the valve seat on the valve housing side,
A drive-side clutch member coupled to the rotor so as to be movable in the axial direction in relation to torque transmission;
A driven side clutch member fixedly connected to the male screw member and facing the driving side clutch member;
An electric control valve in which the drive-side clutch member and the driven-side clutch member constitute a meshing clutch that is always meshed during rotation in the valve opening direction.   The drive-side clutch member and the driven-side clutch member have a serrated clutch pawl having a steep slope and a gentle slope, and mesh with each other on the steep slope side in rotation in the valve opening direction to achieve constant meshing and rotation in the valve closing direction. The electric control valve according to claim 1, wherein the clutch engages with each other on the gentle slope side.   The electric control valve according to claim 1, further comprising a clutch spring that biases the driving side clutch member in an engagement direction with the driven side clutch member.   The electric control valve according to claim 1, further comprising a valve closing spring that biases the male screw member in a valve closing direction.

Images