JP2014088888A - Flow rate control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure balance type flow rate control valve effectively enhancing sealability in a valve closing state.SOLUTION: In a pressure balance type flow rate control valve 1, a taper-shaped seating surface 17, which faces outward, is formed in a valve seat part 16 so that a diameter gradually becomes small toward the side of a lower end part 21a of a valve guide body 21 arranged so as to be opposite to the valve seat part 16 with an interval. In a valve member 30, an annular tip part 31b is provided so as to contact with the seating surface 17 so that a tip surface 18 of the valve seat part 16 is positioned on an inner peripheral side at seating to the valve seat part 16.

Description

  The present invention relates to a flow control valve used in a refrigeration cycle, and more particularly to a pressure balance type flow control valve.

  Conventionally, as such a pressure balance type flow control valve, there are those disclosed in, for example, Patent Document 1 and Patent Document 2. FIG. 14 is a longitudinal sectional view of an electric expansion valve as an example of a conventional pressure balance type flow control valve.

  14 includes a valve main body 801, a valve member 804, a spring 805, a valve rod 806, a packing 807, and an electric actuator 809. The electric expansion valve shown in FIG. .

  The valve body 801 is formed in a substantially cylindrical shape. A first opening 811 communicating with the first fluid passage A1 is provided in the side wall 801a of the valve body 801, and a second opening 812 communicating with the second fluid passage A2 is provided in the bottom wall 801b. Around the second opening 812, a valve seat portion 813 provided with a mortar-shaped seating surface 813a is provided. An upper lid 816 is attached to the upper portion of the valve body 801, and a male screw cylinder 817 is planted on the upper lid 816. The upper end of the valve rod 806 is passed through the male screw cylinder 817.

  The valve member 804 is formed in a cylindrical shape, and is accommodated in the valve body 801 so as to be movable in a piston shape. The valve member 804 partitions the internal space of the valve main body 801 into a valve chamber 814 and a back pressure chamber 815. The valve chamber 814 is in communication with the first opening 811. The lower end of the valve member 804 faces the valve seat portion 813. The valve member 804 is provided with a pressure equalizing path 841 that communicates the second opening 812 and the back pressure chamber 815. The valve member 804 is constantly pressed toward the valve seat 813 by the spring 805. The valve member 804 has a lower end of the valve rod 806 penetrating into the upper portion of the valve member 804 so as to be locked by a stopper 806a. When the valve rod 806 is pulled upward, the stopper 806a is locked to the valve member 804, and the valve member Both 804 are raised. The annular packing 7 is provided so as to prevent fluid leakage between the valve main body 801 and the valve member 804 and not to slide against each other.

  The electric actuator 809 is attached to the upper portion of the valve main body 801 and includes a rotor 892, a stator coil 893, and a shield tube 894. The rotor 892 is provided inside the shield tube 894. The rotor 892 is rotatably attached to the male screw cylinder 817 and is rotatably connected to the upper end portion 863 of the valve rod 806. Stator coil 893 is attached to the outside of shield tube 894.

  The rotor 892 moves in the axial direction (vertical direction in the figure) of the male screw cylinder 817 by rotating. Then, the movement of the rotor 892 is transmitted to the valve rod 806 by the spring 895 so that there is no play, and the valve rod 806 advances and retreats in proportion to the rotation amount of the rotor 892. That is, when the electric actuator 809 is driven, the valve rod 806 and the valve member 804 move up and down, and the valve member 804 is seated / seated with respect to the valve seat portion 813 around the second opening 812.

  In the electric expansion valve 800, the second opening 812 and the back pressure chamber 815 are communicated with each other by a pressure equalizing path 841. Therefore, the pressure balance between the fluid pressure acting on the upper end surface 804b on the back pressure chamber 815 side of the valve member 804 and the fluid pressure acting on the lower end surface 804a on the second opening 812 side of the valve member 804 can be achieved. The driving force of the electric actuator 809 when moving up and down is reduced.

Specifically, if the area of the upper end surface 804b of the valve member 804 is S1, the area of the lower end surface 804a is S2, the fluid pressure in the second opening 812 is P2, and the upward force is positive, the pressure balance when the valve is closed, That is, the force F applied to the valve member 804 in the axial direction (vertical direction in the figure) is expressed by the following equation (i):
F = P2 (S2-S1) (i)
That is, by making the area S1 of the upper end surface 804b and the area S2 of the lower end surface 804a of the valve member 804 the same (substantially identical), the force applied in the axial direction when the valve is closed can be offset or reduced.

JP 2000-320711 A Japanese Patent Laid-Open No. 63-243581

  The flow control valve is required to have high sealing performance (leakage suppression) when the valve is closed. In the electric expansion valve 800 described above, the seating surface 813a seated on the valve member 804 is formed in a mortar shape, and the mortar-shaped seating surface 813a cuts the inside of the annular member serving as the valve seat portion 813. Formed by processing. However, when cutting the inside of the annular member, a force from the inside to the outside is applied to the annular member by the cutting blade, that is, a force is applied to expand the diameter of the annular member. Rigidity in the radial direction is relatively low. For this reason, there has been a problem in that when the inner member is cut, the annular member is deformed and the cutting accuracy is lowered. In addition, since the cutting powder tends to accumulate on the processed surface when cutting the inside of the annular member, the cutting powder is involved in the cutting process, and therefore the surface roughness (surface roughness) of the seating surface 813a is reduced. It was difficult. For these reasons, the degree of adhesion between the valve member 804 and the seating surface 813a tends to be low, and there is room for improvement in terms of sealing performance in the valve closed state.

  Therefore, an object of the present invention is to provide a pressure balance type flow control valve that effectively enhances the sealing performance in the valve closed state.

  In order to achieve the above object, a first aspect of the present invention provides a valve housing in which a first opening and a second opening are formed, and an annular shape provided in the valve housing in communication with the second opening. The shaft center is disposed on an axis passing through the valve seat portion and the shaft center of the valve seat portion, and is provided in the valve housing so that the valve seat portion and one end portion face each other with a space therebetween. A cylinder part, a valve member housed in a piston-like manner in the cylinder part, and a back pressure chamber on the other end side in the cylinder part formed by dividing the space in the cylinder part into the valve member And a pressure equalizing path provided in the valve housing or the valve member so as to communicate with the second opening, and a valve member for moving the valve member so as to be separated from and seated on the valve seat portion A flow control valve having a moving means, The valve seat portion is provided with a tapered seating surface facing outward that is formed so that the diameter gradually decreases toward the cylinder portion, and the valve member is seated on the valve seat portion. The flow rate control valve is characterized in that an annular tip portion that is in contact with the seating surface is provided so that an end portion of the valve seat portion on the cylinder portion side is sometimes positioned on an inner peripheral side.

  The invention described in claim 2 is the invention described in claim 1, wherein the valve member moving means is configured such that a straight line connecting the shortest distance between the annular tip and the seating surface is the seat at the annular tip. The valve member is configured to move within a range that passes through a portion in contact with the surface.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the inner diameter of the annular tip portion is the same as the inner diameter of the cylinder portion.

  The invention described in claim 4 is the invention described in any one of claims 1 to 3, wherein a mortar-shaped inclined surface is provided on an inner edge of the annular tip, and the inclined surface with respect to the axis is provided. Is made larger than the angle of the seating surface with respect to the axis.

  The invention described in claim 5 is the invention described in any one of claims 1 to 4, wherein the seating surface has a plurality of tapered annular surface portions having different angles with respect to the axis. It is characterized by being.

  According to the first aspect of the present invention, in the pressure balance type flow control valve in which the back pressure chamber and the second opening are communicated with each other by the pressure equalizing passage, the valve seat portion gradually approaches the cylinder portion side. The valve member is provided with a taper-shaped seating surface that is formed so as to have a smaller diameter, and the end of the valve seat on the cylinder side is seated on the inner peripheral side when seated on the valve seat. Since the annular tip portion that contacts the seating surface is provided so as to be positioned, such a tapered seating surface is formed by cutting the outer side of the annular member serving as the valve seat portion. Cutting to the outside of the annular member applies a force from the outside to the inside of the annular member by the cutting blade, that is, a force is applied to reduce the diameter of the annular member. Since the rigidity with respect to the direction is higher than the rigidity with respect to the diameter-enlarging direction, the degree of deformation of the annular member when cutting outside the annular member is the degree of deformation of the annular member when cutting inside the annular member. Therefore, the seating surface can be formed with higher accuracy. In addition, the cutting to the outside makes it difficult for the cutting powder to accumulate on the machined surface compared to the cutting to the inside, and the surface roughness of the seating surface can be easily reduced by suppressing the entrainment of the cutting powder during the cutting process. . From these things, the close_contact | adherence degree of the cyclic | annular front-end | tip part of a valve member and a seating surface becomes high, and can improve the sealing performance in a valve closed state effectively.

  According to the invention described in claim 2, the valve member moving means is within a range in which the straight line connecting the shortest distance between the annular tip portion and the seating surface passes through the portion of the annular tip portion contacting the seating surface. The valve member is configured to move. When the seating surface and the valve member (specifically, the annular tip) are separated from each other, the fluid pressure on the first opening side is on the line connecting the shortest distance between the seating surface and the valve member in the gap generated between them. And a boundary between the fluid pressure on the second opening side. When the valve member is moved within the above range of the present invention, the portion of the annular tip that contacts the seating surface is always closest to the seating surface, and therefore, the first opening side between the portion and the seating surface. A boundary is formed between the fluid pressure and the fluid pressure on the second opening side. As a result, even when the valve member is moved, the fluid pressure of the second opening is always applied to the inner portion of the annular tip portion, so the portion of the valve member on the second opening side where the fluid pressure of the second opening is applied. When the valve member in the valve closed state is moved in the axial direction so as to be separated from the valve seat portion, the balance of the force applied to the valve member in the axial direction is changed. This can be suppressed.

  According to the invention described in claim 3, since the inner diameter of the annular tip is the same as the inner diameter of the cylinder, the area in plan view inside the annular tip of the valve member and the cylinder of the valve member In the seating state (valve closed state) in which the annular tip portion is in contact with the seating surface, the fluid pressure applied from the annular tip portion side to the valve member The force applied in the axial direction of the valve member can be balanced by making the fluid pressure applied from the back pressure chamber side the same, thereby reducing the force required to move the valve member and moving the valve member The valve member moving means to be made can be reduced in size.

  According to the invention described in claim 4, a mortar-shaped inclined surface is provided at the inner edge of the annular tip portion, and the angle of the inclined surface with respect to the axis is larger than the angle of the seating surface with respect to the axis. In addition, the end of the inclined surface of the annular tip portion on the opposite side to the valve seat portion side can be a place in contact with the seating surface of the annular tip portion, and the pressure balance can be reliably maintained.

  According to the invention described in claim 5, since the seating surface has a plurality of tapered annular surface portions having different angles with respect to the axis, the angle of each annular surface portion with respect to the axis is adjusted. The moving distance of the valve member, that is, the flow rate (flow rate characteristic) with respect to the valve opening degree can be easily set.

It is a longitudinal cross-sectional view of the motor operated valve which is 1st Embodiment of the flow control valve concerning this invention. It is an expanded sectional view showing typically the valve member and valve seat part of the electric valve of Drawing 1, and is a figure in which a valve member is in a seating position (valve closed state). It is an expanded sectional view showing typically the valve member and valve seat part of the electric valve of Drawing 1, and is a figure in the position (valve half-open state) where the valve member separated from the valve seat part. FIG. 4 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the electric valve of FIG. 1, and is a view in which the valve member is further away from the valve seat portion (valve half-open state) than the state of FIG. 3. is there. It is an expanded sectional view showing typically the valve member and valve seat part of the electric valve of Drawing 1, and is a figure in which a valve member is in a valve open upper limit position (valve open upper limit state). It is the expanded sectional view which showed typically the valve member and valve seat part of the electrically operated valve of FIG. 1, Comprising: It is a figure in which the valve member exists in the position beyond the valve opening upper limit position. It is the expanded sectional view which showed typically the valve member and valve seat part of the motor operated valve which is 2nd Embodiment of the flow control valve concerning this invention, Comprising: It is a figure which has a valve member in a seating position (valve closed state). is there. It is an expanded sectional view showing typically the valve member and valve seat part of an electric valve which is a 2nd embodiment, and is a figure in the position (valve half-open state) where the valve member separated from the valve seat part. FIG. 9 is an enlarged cross-sectional view schematically showing a valve member and a valve seat portion of an electric valve according to a second embodiment, in which the valve member is further away from the valve seat portion than the state of FIG. 8 (valve half-open state). FIG. It is the expanded sectional view which showed typically the valve member and valve seat part of the motor operated valve which is 2nd Embodiment, Comprising: (a) is a figure which has a valve member in a valve open upper limit position (valve open upper limit state). (B) is a diagram further enlarging a part of (a). It is an expanded sectional view showing typically the valve member and valve seat part of the electric valve which is a 2nd embodiment, and is a figure in the position where the valve member exceeded the valve opening upper limit position. It is an expanded sectional view showing the composition of the modification of the valve seat part of the electric valve which is a 2nd embodiment. It is a graph which shows typically the relation between the angle to the axis and the flow rate in the annular surface portion of the valve seat. It is a longitudinal cross-sectional view of the conventional flow control valve.

(First embodiment of the present invention)
Below, the motor-operated valve as 1st Embodiment of the flow control valve of this invention is demonstrated with reference to FIGS.

  FIG. 1 is a longitudinal sectional view of an electric valve that is a first embodiment of a flow control valve according to the present invention. Note that the concept of “upper and lower” in the following description corresponds to the upper and lower sides in each figure, and indicates the relative positional relationship between the members, and does not indicate the absolute positional relationship.

  The motor-operated valve of this embodiment (indicated by reference numeral 1 in each figure) includes a valve body 10 as a valve housing, a valve seat portion 16, a valve guide 20 as a cylinder portion, a valve member 30, and a pressure equalizing path. 36 and a valve member driving unit 40 as a valve member moving means.

  The valve body 10 is formed in a substantially cylindrical shape, and a valve chamber 10A is formed inside thereof. The valve body 10 has a circular first opening 11 formed in a peripheral wall 10a thereof, and a circular second opening 12 formed in a bottom wall 10b of the lower end thereof. The primary side joint pipe A1 is fixedly attached to the first opening 11, and the primary side joint pipe A1 and the primary side port 13 in the valve chamber 10A communicate with each other. In addition, a secondary side joint pipe A2 is fixedly attached to the second opening 12, and the secondary side joint pipe A2 and a secondary side port 14 in a valve seat portion 16, which will be described later, communicate with each other. .

  The valve seat portion 16 is formed in a circular ring shape, and is provided in the valve body 10 so as to communicate with the second opening 12. The valve seat portion 16 is connected to an upper end of the seating surface 17 and a single taper-shaped seating surface 17 that is formed so that the diameter gradually decreases from the lower side to the upper side in the drawing. It has a front end surface 18 that faces in the middle and upper direction, and a valve seat inner peripheral surface 19 that is connected to the inner edge of the front end surface 18 and is provided inside the valve seat portion 16. When the later-described valve member 30 is seated on the valve seat portion 16, the seating surface 17 is brought into contact with the valve member 30 so that the distal end surface 18 is positioned inside thereof. The valve seat inner peripheral surface 19 is formed to have substantially the same diameter as the inner diameter of the secondary side joint pipe A <b> 2, and defines the secondary side port 14.

  The valve guide 20 includes a valve guide main body 21 and a valve guide lid 22. The valve guide main body 21 is formed in a substantially cylindrical shape with both ends opened. The valve guide main body portion 21 is disposed such that its lower end portion 21a and the valve seat portion 16 are opposed to each other with an interval so that the shaft center thereof overlaps an axis P passing through the shaft center of the valve seat portion 16. The valve body 10 is fixedly attached. The valve guide lid portion 22 is fixed and attached to the valve guide main body portion 21 with a fixing bracket 23 so as to close the upper end portion 21 b of the valve guide main body portion 21. The valve guide lid portion 22 is provided with an internal thread portion 22a formed so as to penetrate the valve guide lid portion 22 in the vertical direction. In the present embodiment, the valve guide main body 21 is configured as a separate member from the valve main body 10. However, the present invention is not limited thereto, and the valve guide main body 21 may be configured integrally with the valve main body 10.

  The valve member 30 is formed in a substantially cylindrical shape as a whole, and is disposed in the valve guide 20 so as to be slidable in the vertical direction. That is, the valve member 30 is accommodated in the valve guide 20 so as to be movable like a piston. The valve member 30 is accommodated in the valve guide 20, thereby defining a space in the valve guide 20, and a back pressure chamber 25 is formed on the upper end portion 21 b side in the valve guide 20.

  The valve member 30 includes a valve body 31, a connection fitting 34, and a packing part 37.

  The valve body 31 has an inner diameter that is connected to the cylindrical valve body main body 31a having the same outer diameter as the inner diameter of the valve guide main body 21 and the valve seat 16 side end of the valve body main body 31a. Has an annular tip 31b having the same cylindrical shape as the outer diameter of the valve body main body 31a. The valve body main part 31a and the annular tip part 31b are configured integrally so that their axial centers are aligned. Further, the valve body 31 (specifically, the valve body main body 31a and the annular tip portion 31b) is disposed so that the axis thereof overlaps the axis P. The valve body 31 is disposed so that the outer peripheral surface 31c of the valve body main body 31a is slidably in contact with the inner peripheral surface 21c of the valve guide main body 21. The annular tip 31b is disposed so as to protrude from the lower end 21a of the valve guide main body 21. At the inner edge of the tip 31d of the annular tip 31b of the valve body 31, a mortar-shaped inclined surface 33 whose diameter decreases toward the upper side in the drawing is provided over the entire circumference.

  The valve body 31 is separated and seated on the valve seat portion 16 according to the movement of the valve member 30. Specifically, the annular tip 31b of the valve body 31 is separated from the seating surface 17 of the valve seat portion 16 (separated) or abutted against the seating surface 17 of the valve seat portion 16 (seating). The angle formed between the axis P and the inclined surface 33 is larger than the angle formed between the axis P and the seating surface 17. In other words, the angle of the inclined surface 33 with respect to the axis P is larger than the angle of the seating surface 17 with respect to the axis P. Thereby, when the valve body 31 is seated, the upper end portion 33 a of the inclined surface 33 of the annular tip portion 31 b is brought into contact with the seating surface 17 so as to surround the tip surface 18 of the valve seat portion 16. That is, the annular tip 31b contacts the seating surface 17 so that the end (tip surface 18) on the valve guide 20 side of the valve seat 16 is positioned on the inner peripheral side when seated on the valve seat 16. At this time, the valve body 31 closes the secondary side port 14 inside the valve seat portion 16 to be in a valve closed state.

  The connection fitting 34 is formed in a substantially cylindrical shape having a smaller outer diameter than the valve body main part 31 a of the valve body 31. The connecting bracket 34 has a lower end portion 34a opened and a spring receiving portion 35 provided on the upper end portion 34b. A through hole 34d that communicates the inside and the outside of the connection fitting 34 is formed at a location near the upper end 34b of the peripheral wall 34c of the connection fitting 34, and a flange portion 34e is provided at a position below the through hole 34d. .

  The lower end 34a of the coupling fitting 34 is fixedly attached through the valve body main body 31a of the valve body 31. As a result, the inner space of the annular tip 31 b of the valve body 31, the inner space of the connection fitting 34, and the through hole 34 d communicate with each other to form a pressure equalizing path 36. The pressure equalizing path 36 communicates the space below the valve body 31 in the figure with the back pressure chamber 25. That is, the back pressure chamber 25 is communicated with the second opening 12 via the valve seat portion 16.

  The packing part 37 is formed in a circular ring shape, and its outer edge is configured to come into slidable contact with the inner peripheral surface 21c of the valve guide main body part 21 in an airtight state. The packing part 37 is sandwiched between the flange part 34 e of the connecting metal fitting 34 and the upper surface 31 e of the valve body main part 31 a of the valve body 31 together with the disc spring receiver 38 and the disc spring 39.

  The valve member 30 divides the back pressure chamber 25 by a packing portion 37 that slidably contacts the inner periphery of the valve guide 20 in an airtight state. That is, the plan view area of the valve member 30 on the back pressure chamber 25 side is: The cross-sectional area inside the valve guide 20 is the same. Further, since the valve member 30 has the same inner diameter of the annular tip 31b as the outer diameter of the valve body body 31a, that is, the same as the inner diameter of the valve guide 20, the plan view area inside the annular tip 31b. Is the same as the cross-sectional area inside the valve guide 20. Therefore, the planar view area on the back pressure chamber 25 side in the valve member 30 and the planar view area on the inner side of the annular tip portion 31b are the same. Accordingly, by applying the fluid pressure on the second opening 12 side only to the inside of the annular tip portion 31b, the fluid pressure applied from the back pressure chamber 25 side to the valve member 30 and the inside of the annular tip portion 31b are applied. Fluid pressure can be balanced.

  The second opening 12, the valve seat portion 16, the valve guide 20, and the valve member 30 (the valve body 31 and the connecting metal fitting 34) are arranged so that their axis centers overlap the axis line P.

  The valve member driving unit 40 includes a valve member holder 50 and a motor 60.

  The valve member holder 50 includes a holder portion 51, a coiled compression spring 53, and a spring receiving portion 54. The holder portion 51 is formed in a substantially cylindrical shape in which the lower end portion 51 a is opened and the upper end portion 51 b is closed by the upper wall 52. A compression spring 53 is accommodated in the holder portion 51, and a spring receiving portion 54 is accommodated so as to be movable in the vertical direction within the holder portion 51 so as to receive the upper end portion of the compression spring 53. Further, the spring receiving portion 35 of the coupling fitting 34 of the valve member 30 is fixedly attached to the lower end portion 51 a of the holder portion 51 so as to receive the lower end portion of the compression spring 53. As a result, the spring receiving portion 54 is pressed against the upper wall 52 of the holder portion 51 by the compression spring 53. The upper wall 52 of the holder part 51 has a lower end 64a of a rotor shaft 64 of the motor 60 described later passing therethrough so as to be rotatable with respect to the holder part 51. The part 54 is in contact.

  The motor 60 is configured by a stepping motor, and includes a motor case 61, a magnet rotor 63, a stator coil 66, and a rotation stopper mechanism 70.

  The motor case 61 is formed in a substantially cylindrical shape in which a lower end portion 61 a is opened and an upper end portion 61 b is closed by an upper wall 62. The motor case 61 is attached with its lower end 61 a fixed to the upper end 21 b of the valve guide main body 21.

  The magnet rotor 63 is accommodated in the motor case 61 coaxially. The magnet rotor 63 has a rotor shaft 64 and a magnet portion 65 fixedly attached to the rotor shaft 64. The rotor shaft 64 is arranged such that its axis is positioned on the axis P. A male screw part 64 b is provided on a part of the outer peripheral surface of the rotor shaft 64, and is screwed into the female screw part 22 a of the valve guide lid part 22. Thus, since the magnet rotor 63 is screwed with the valve guide 20 (specifically, the valve guide lid portion 22), the magnet rotor 63 moves in the direction of the axis P (that is, the vertical direction) by being rotated.

  The stator coil 66 is fixedly attached to the outer peripheral surface of the motor case 61. The stator coil 66 rotates the magnet rotor 63 according to the number of pulses included in the pulse signal when a pulse signal is applied.

  The rotation stopper mechanism 70 is provided on the inner surface side of the upper wall 62 of the motor case 61. The rotation stopper mechanism 70 includes a spiral guide wire 71 and a movable stopper member 72 that is kicked between the spirals of the spiral guide wire 71 by a flange 65a attached to the magnet portion 65 of the magnet rotor 63. ing. In the rotation stopper mechanism 70, when the magnet rotor 63 moves to a predetermined upper limit position (that is, the valve opening upper limit position of the valve member 30), the movable stopper member 72 becomes a stopper (not shown) provided in the motor case 61. bump into. Thereby, rotation of the magnet rotor 63, that is, movement beyond the upper limit position is restricted.

  Next, with reference to FIGS. 2-6, the operation | movement (action) in the motor operated valve 1 of this embodiment mentioned above is demonstrated.

  FIG. 2 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the motor-operated valve in FIG. 1, in which the valve member is in a seating position (valve closed state). FIG. 3 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the motor-operated valve of FIG. 1, and is a view in a position (valve half-open state) where the valve member is separated from the valve seat portion. . 4 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the motor-operated valve of FIG. 1, and the position where the valve member is further away from the valve seat portion than the state of FIG. 3 (valve half-open state) FIG. FIG. 5 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the motor-operated valve in FIG. 1, and is a view in which the valve member is in the valve open upper limit position (valve open upper limit state). FIG. 6 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the electric valve in FIG. 1, and is a view in which the valve member is in a position beyond the valve opening upper limit position.

  As described above, in the motor-operated valve 1, the seat surface 17 is provided on the valve seat portion 16, and the inclined surface 33 is provided on the valve body 31. Further, as shown in FIG. 2, the angle of the seating surface 17 with respect to the axis P is set to α, and the angle of the inclined surface 33 with respect to the axis P is set to β which is larger than the angle α (where α <β < 90 degrees).

  Further, the diameter of the valve seat inner peripheral surface 19 of the valve seat portion 16 is set to D1, the diameter of the upper end portion 17a of the seating surface 17 is set to D2 larger than the outer diameter D1, and the annular tip 31b of the valve body 31 The inner diameter (that is, the diameter of the upper end portion 33a of the inclined surface 33) is set to D3 larger than the diameter D2. Thereby, when the valve body 31 is in the seating position (valve closed state) seated on the valve seat portion 16, the upper end portion 33 a of the inclined surface 33 is in contact with the seating surface 17 and the annular tip portion 31 b is With the distal end surface 18 positioned on the inner peripheral side, the valve body 31 covers the valve seat portion 16 and the secondary side port 14 is closed. That is, the upper end portion 33 a is a portion in contact with the seating surface 17 at the annular tip portion 31 b of the valve member 30.

  Thus, when the valve body 31 is in the seating position, the upper end portion 33a is in contact with the seating surface 17, so that in the valve closed state, the portion inside the upper end portion 33a of the valve body 31 (that is, the annular tip portion 31b). The fluid pressure (second pressure P2) of the secondary side port 14 is applied to the inner side of the valve member 30, and the fluid pressure of the secondary side port 14 is also applied to the location on the back pressure chamber 25 side of the valve member 30 through the pressure equalizing path 36. . As described above, the plan view area on the back pressure chamber 25 side of the valve member 30 and the plan view area on the inner side of the annular tip portion 31 b are the same, and therefore the back pressure chamber 25 with respect to the valve member 30. The fluid pressure applied from the side and the fluid pressure applied to the inner side of the annular tip 31b are balanced.

  Next, when the valve body 31 moves away from the seating position and gradually moves in the direction of the axis P, a gap is generated between the seating surface 17 and the valve body 31 (specifically, the annular tip portion 31b). At this time, the boundary line k between the fluid pressure on the first opening 11 side (first pressure P1) and the fluid pressure on the second opening 12 side (second pressure P2) is the shortest distance between the seating surface 17 and the annular tip 31b. Occurs on a line connecting distances. In the motor-operated valve 1, as shown in FIG. 3, the valve body 31 moves while maintaining the state where the upper end portion 33 a of the inclined surface 33 of the annular tip portion 31 b is closest to the seating surface 17. In other words, the straight line connecting the shortest distance between the annular tip 31b of the valve member 30 and the seating surface 17 moves while maintaining a state in which the straight line passes through the upper end portion 33a of the valve member 30. Therefore, in this state, the boundary between the fluid pressure on the first opening 11 side (first pressure P1) and the fluid pressure on the second opening 12 side (second pressure P2) between the upper end portion 33a and the seating surface 17. Line k results. That is, even in this half-open state, since the second pressure P2 of the secondary port 14 is applied to the portion inside the upper end portion 33a of the valve body 31, the area to which the second pressure P2 is applied does not change. The balance of the force applied in the direction of the axis P of the valve member 30 is maintained. When the valve member 30 is in a position in which such a valve is in a half-open state, when a perpendicular is drawn from the upper end portion 33 a of the inclined surface 33 to the seating surface 17, the perpendicular foot is located on the seating surface 17. This perpendicular becomes the boundary line k.

  As the moving distance x from the seating position of the valve member 30 increases, the distance (the length of the boundary line k) between the upper end portion 33a of the inclined surface 33 and the seating surface 17 increases.

  Then, when the valve body 31 is further moved away from the seating position in the direction of the axis P, and the vertical line is lowered from the upper end portion 33a of the inclined surface 33 to the seating surface 17, the vertical leg is moved to the upper end thereof as shown in FIG. Even if it comes to be located in the part 17a, in the valve body 31, the upper end location 33a becomes the location closest to the seating surface 17. That is, this perpendicular becomes the boundary line k between the first pressure P1 and the second pressure P2, and even in this state, the second pressure P2 of the secondary port 14 is in the portion inside the upper end portion 33a of the valve body 31. As a result, the area to which the second pressure P2 is applied does not change, and therefore, the balance of the force applied in the direction of the axis P of the valve member 30 is maintained. This perpendicular is also a normal line at the upper end portion 17 a of the seating surface 17.

  After that, when the valve body 31 further moves away from the seating position and moves in the direction of the axis P, as shown in FIG. 5, contrary to the above, when the perpendicular is lowered from the upper end portion 17a of the seating surface 17 to the inclined surface 33 The upper end portion 33a of the valve body 31 is the closest portion to the seating surface 17 even when the vertical leg is at the valve opening upper limit position located at the upper end portion 33a. That is, this perpendicular line becomes the boundary line K between the first pressure P1 and the second pressure P2, and even in this valve open upper limit state, the second side of the secondary port 14 is located in the portion inside the upper end portion 33a of the valve body 31. Since the pressure P2 is applied, the area to which the second pressure P2 is applied does not change, so that the balance of the force applied in the direction of the axis P of the valve member 30 is maintained. This perpendicular is also a normal line at the upper end portion 33 a of the inclined surface 33.

  Then, if the valve element 31 moves further away from the seating position than the valve opening upper limit position in the axis P direction, as shown in FIG. 6, a position on the inclined surface 33 below the upper end portion 33 a of the inclined surface 33. 33b is the closest location to the seating surface 17 in the valve body 31, and the line connecting the location 33b and the upper end portion 17a of the seating surface 17 is the boundary line K ′ between the first pressure P1 and the second pressure P2. It becomes. Therefore, in this state, the second pressure P2 of the secondary port 14 is applied to a portion of the valve body 31 inside the portion 33b having a diameter larger than the upper end portion 33a. The second pressure P <b> 2 applied to the position increases, thereby changing the balance of the force applied in the direction of the axis P of the valve member 30.

  As described above, in the motor-operated valve 1 of the present embodiment, the valve member 30 (specifically, the valve member 30 is within the range in which the second pressure P2 of the secondary port 14 is applied to the portion inside the upper end portion 33a of the valve body 31). By moving the body 31), the balance of the force applied in the direction of the axis P of the valve member 30 can be maintained, and the balance can be prevented from changing. In other words, in the motor-operated valve 1, the valve member 30 is moved within a range in which a straight line connecting the shortest distance between the valve member 30 (specifically, the annular tip portion 31b) and the seating surface 17 passes through the upper end portion 33a of the valve member 30. Move.

  In the motor-operated valve 1, the position of the valve member 30 shown in FIG. 5 is set as the valve opening upper limit position, and the rotation stopper mechanism 70 prevents the valve member 30 from separating from the valve seat portion 16 beyond the valve opening upper limit position. The movement of the member 30 is restricted. In addition to this, the valve member 30 may be controlled so as not to exceed the valve opening upper limit position by counting the number of pulse signals applied to the stator coil 66 of the motor 60.

As shown in FIG. 5, the diameter of the upper end portion 17a of the seating surface 17 is D2, the inner diameter of the annular tip 31b of the valve body 31 is D3, the angle between the axis P and the seating surface 17 is α, and the axis P and the inclined surface. If the angle formed by 33 is β, the movement distance L from the seating position to the valve opening upper limit position in the valve member 30 is expressed by the following equation (1).
L = h1 + h2
= [{(D3-D2) / 2} × tan (90 ° −α)]
+ [{(D3-D2) / 2} × tan β] (1)

Here, the radius of the diameter D2 (that is, the distance from the axis P to the upper end portion 17a of the seating surface 17) is R2, and the radius of the inner diameter D3 (that is, the distance from the axis P to the upper end portion 33a of the inclined surface 33) is R3. Then
L = (R3-R2) / tan α + (R3-R2) tan β
= (R3-R2) (1 / tan α + tan β) (2)
It becomes.

Since the moving distance x of the valve member 30 is in the range from 0 to L,
0 ≦ x ≦ (R3−R2) (1 / tan α + tan β) (A)
If the moving distance x is in a range that satisfies the above formula (A), the range in which the straight line connecting the shortest distance between the valve member 30 and the seating surface 17 passes through the upper end portion 33a of the seating surface 17 in the valve member 30. The valve member 30 is moved inside, and the balance of the force applied in the direction of the axis P of the valve member 30 can be maintained.

  The motor-operated valve 1 according to the above-described embodiment includes a valve main body 10 in which a first opening 11 and a second opening 12 are formed, and an annular valve seat portion 16 provided in the valve main body 10 so as to communicate with the second opening 12. And the valve guide 20 provided in the valve main body 10 so that the shaft center is disposed on the axis P passing through the shaft center of the valve seat portion 16 and the valve seat portion 16 and the lower end portion 21a face each other with a space therebetween. A valve member 30 that is movably accommodated in a piston shape in the valve guide 20, and a back on the upper end 21 b side in the valve guide 20 that is formed by dividing a space in the valve guide 20 into the valve member 30. A pressure equalizing path 36 provided in the valve member 30 so as to communicate the pressure chamber 25 and the second opening 12, and a valve member that moves the valve member 30 so as to be separated from and seated on the valve seat portion 16. Drive unit 40. In addition, the motor-operated valve 1 is provided with a seating surface 17 having a tapered shape facing the outside formed in the valve seat portion 16 so that the diameter gradually decreases toward the lower end portion 21a side of the valve guide 20. The member 30 is provided with an annular tip 31b that contacts the seating surface 17 so that the tip surface 18 of the valve seat 16 is positioned on the inner peripheral side when seated on the valve seat 16.

  In the motor-operated valve 1, the inner diameter of the annular tip portion 31 b is the same as the inner diameter of the valve guide 20.

  In the motor-operated valve 1, the valve member driving unit 40 is in a state where a straight line connecting the shortest distance between the annular tip portion 31 b and the seating surface 17 passes through the upper end portion 33 a contacting the seating surface 17 in the annular tip portion 31 b. It is comprised so that the valve member 30 may be moved in the inside.

  Further, the motor-operated valve 1 is provided with a mortar-shaped inclined surface 33 at the inner edge of the tip 31d of the annular tip 31b, and the angle β of the inclined surface 33 with respect to the axis P is larger than the angle α of the seating surface 17 with respect to the axis P. Has been.

  As described above, according to the present embodiment, in the pressure balance type electric valve 1 in which the back pressure chamber 25 and the second opening 12 are communicated with each other by the pressure equalizing path 36 of the valve member 30, the valve seat portion 16 includes the valve A tapered seating surface 17 facing outward is formed so that the diameter gradually decreases toward the lower end 20a side of the valve guide 20 disposed facing the seat 16 with a space therebetween, Since the valve member 30 is provided with an annular tip portion 31b that contacts the seating surface 17 so that the tip surface 18 of the valve seat portion 16 is positioned on the inner peripheral side when seated on the valve seat portion 16, The tapered seating surface 17 is formed by cutting the outer side of the annular member that becomes the valve seat portion 16. Cutting to the outside of the annular member applies a force from the outside to the inside of the annular member by the cutting blade, that is, a force is applied to reduce the diameter of the annular member. Since the rigidity with respect to the direction is higher than the rigidity with respect to the diameter-enlarging direction, the degree of deformation of the annular member when cutting outside the annular member is the degree of deformation of the annular member when cutting inside the annular member. Therefore, the seating surface 17 can be formed with higher accuracy. Further, the cutting to the outside is less likely to collect cutting powder on the machining surface than the cutting to the inside, and the surface roughness of the seating surface 17 is easily reduced by suppressing the entrainment of the cutting powder at the time of cutting. it can. From these things, the close_contact | adherence degree of the cyclic | annular front-end | tip part 31b of the valve member 30 and the seating surface 17 becomes high, and can improve the sealing performance in a valve closed state effectively.

  Further, the valve member 30 is within a range where the straight line connecting the shortest distance between the annular tip portion 31b and the seating surface 17 passes through the upper end portion 33a in contact with the seating surface 17 in the annular tip portion 31b. Is configured to move. When the seating surface 17 and the valve member 30 (specifically, the annular tip 31b) are separated from each other and the valve is opened, the shortest distance between the seating surface 17 and the valve member 30 is a gap generated between them. A boundary line k between the fluid pressure on the first opening 11 side and the fluid pressure on the second opening 12 side is generated on the line connecting the two. In the present embodiment, when the valve member 30 is moved within such a range, the upper end portion 33a in contact with the seating surface 17 in the annular tip portion 31b is always closest to the seating surface 17, and therefore, the upper end portion 33a. A boundary k between the fluid pressure on the first opening 11 side and the fluid pressure on the second opening 12 side occurs between the seating surface 17 and the seating surface 17. Thereby, even if the valve member 30 is moved, the fluid pressure of the second opening 12 is always applied to the inner portion of the annular tip portion 31b from the upper end portion 33a. Even if the valve member 30 in the valve closed state is moved in the direction of the axis P so as to be separated from the valve seat portion 16, the valve member 30 is not changed in the planar view area of the portion on the second opening 12 side to be added. It can suppress that the balance of the force added to the said axis line P direction changes.

  Further, since the inner diameter of the annular tip 31b is the same as the inner diameter of the valve guide 20, the planar view area inside the annular tip 31b in the valve member 30 and the back pressure of the valve guide 20 cylinder part in the valve member 30 Thus, the fluid pressure applied to the valve member 30 from the annular tip portion 31b side in the seating state (valve closed state) in which the annular tip portion 31b is in contact with the seating surface 17 is the same as the planar view area on the chamber 25 side. And the fluid pressure applied from the back pressure chamber 25 side can be made equal to balance the force applied in the direction of the axis P of the valve member 30, thereby reducing the force required to move the valve member 30. The valve member drive unit 40 that moves the valve member 30 can be downsized.

  Further, a mortar-shaped inclined surface 33 is provided on the inner edge of the tip 31d of the annular tip 31b, and the angle β of the inclined surface 33 with respect to the axis P is larger than the angle α of the seating surface 17 with respect to the axis P. Therefore, the upper end portion 33a of the inclined surface 33 of the annular tip portion 31b can be a portion that contacts the seating surface 17 of the annular tip portion 31b, and the pressure balance can be reliably maintained. In addition, a flow path is formed by the inclined surface 33 and the seating surface 17, and the flow of fluid can be adjusted.

(Second embodiment of the present invention)
Below, the motor operated valve as 2nd Embodiment of the flow control valve of this invention is demonstrated with reference to FIGS.

  FIG. 7 is an enlarged cross-sectional view schematically showing a valve member and a valve seat portion of an electric valve which is a second embodiment of the flow control valve according to the present invention, in which the valve member is in a seating position (valve closed state). FIG. FIG. 8 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the electric valve according to the second embodiment, and is in a position (valve half-open state) where the valve member is separated from the valve seat portion. FIG. FIG. 9 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the electric valve according to the second embodiment. The valve member is further away from the valve seat portion than the state of FIG. It is a figure in a state. FIG. 10 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the electric valve according to the second embodiment, in which (a) shows the valve member at the valve opening upper limit position (valve opening upper limit state). (B) is a further enlarged view of part of (a). FIG. 11 is an enlarged cross-sectional view schematically showing the valve member and the valve seat portion of the electric valve according to the second embodiment, and is a view in which the valve member is in a position beyond the valve opening upper limit position. FIG. 12 is an enlarged cross-sectional view illustrating a configuration of a modified example of the valve seat portion of the electric valve according to the second embodiment.

  In the motor-operated valve 1A of the second embodiment, in the motor-operated valve 1 of the first embodiment described above, the valve seat portion 16 is replaced with a single taper-shaped seating surface 17, and a plurality of angles with respect to the axis P are different from each other. Since it is the same as the motor-operated valve 1 of the first embodiment except that it has a seating surface 17A provided with a tapered annular surface portion facing outward, the same reference numerals are assigned to the same portions. The description is omitted.

  The seating surface 17A of the valve seat portion 16 is provided with two tapered first and second annular surface portions 171 and 172 having different angles with respect to the axis P. The first annular surface portion 171 and the second annular surface portion 172 are arranged side by side in the axis P direction so as to be connected to each other. In this embodiment, two annular surface portions are provided, but three or more annular surface portions may be arranged side by side in the axis P direction.

  Next, with reference to FIGS. 7-12, the operation | movement (action) in the motor operated valve 1A of this embodiment mentioned above is demonstrated.

  The motor-operated valve 1A is provided with a seating surface 17A having a first annular surface portion 171 and a second annular surface portion 172 on the valve seat portion 16, and a mortar on the inner edge of the tip 31d of the annular tip 31b of the valve body 31. An inclined surface 33 having a shape is provided. Further, as shown in FIG. 7, the angle of the first annular surface portion 171 on the side away from the tip surface 18 of the valve seat portion 16 with respect to the axis P is set to α1, and the tip surface 18 of the valve seat portion 16 with respect to the axis P is set. The angle of the second annular surface portion 172 on the near side is set to α2 larger than the angle α1. In addition, both the angle α1 and the angle α2 are set to be smaller than the angle β of the inclined surface 33 with respect to the axis P (where α1 <α2 <β <90 degrees).

  Further, the diameter of the valve seat portion inner peripheral surface 19 of the valve seat portion 16 is set to D1, the diameter of the upper end portion 17a of the seating surface 17A is set to D2 larger than the diameter D1, and the first annular surface portion 171 and the second annular surface portion are set. The diameter of the boundary portion 17b with the surface portion 172 is set to D2 ′ larger than the diameter D2, and the inner diameter of the annular tip 31b of the valve body 31 (that is, the diameter of the upper end portion 33a of the inclined surface 33) is larger than the diameter D2 ′. D3 is set. Thereby, when the valve body 31 is in the seating position (valve closed state) seated on the valve seat portion 16, the upper end portion 33a of the inclined surface 33 is in contact with the first annular surface portion 171 of the seating surface 17A and the annular tip portion. 31b positions the front end face 18 of the valve seat 16 on the inner peripheral side, the valve body 31 covers the valve seat 16 and the secondary port 14 is closed. That is, the upper end portion 33 a is a portion that contacts the seating surface 17 </ b> A at the annular tip portion 31 b of the valve member 30.

  Thus, when the valve body 31 is in the seating position, the upper end portion 33a is in contact with the seating surface 17A. Therefore, in the valve closed state, the secondary port 14 is provided in a portion inside the upper end portion 33a of the valve body 31. The fluid pressure (second pressure P2) is applied, and the fluid pressure of the secondary port 14 is also applied to the valve member 30 on the back pressure chamber 25 side through the pressure equalizing path 36. As described above, the plan view area on the back pressure chamber 25 side of the valve member 30 and the plan view area on the inner side of the annular tip portion 31 b are the same, and therefore the back pressure chamber 25 with respect to the valve member 30. The fluid pressure applied from the side and the fluid pressure applied to the inner side of the annular tip 31b are balanced.

  Next, when the valve body 31 is gradually moved away from the seating position in the direction of the axis P, as shown in FIG. 8, the upper end portion 33a of the valve body 31 is the seating surface 17A (specifically, the first annular surface). The portion 171 or the second annular surface portion 172) moves while maintaining the closest position. In other words, the straight line connecting the shortest distance between the annular tip 31b of the valve member 30 and the seating surface 17A moves while maintaining a state of passing through the upper end portion 33a of the valve member 30. Therefore, in this state, the boundary between the fluid pressure on the first opening 11 side (first pressure P1) and the fluid pressure on the second opening 12 side (second pressure P2) between the upper end portion 33a and the seating surface 17A. Line k results. That is, even in this half-open state, since the second pressure P2 of the secondary port 14 is applied to the portion inside the upper end portion 33a of the valve body 31, the area to which the second pressure P2 is applied does not change. The balance of the force applied in the direction of the axis P of the valve member 30 is maintained. When the valve member 30 is in a position in which such a valve is in a half-opened state, when a vertical line is dropped from the upper end portion 33a of the inclined surface 33 to the seating surface 17A, the vertical foot becomes the seating surface 17A (in this case, the second annular shape). The surface portion 172 is located on the axis P side). This perpendicular becomes the boundary line k. In FIG. 8, the valve element 31 moves to a position where the leg of the perpendicular line is on the boundary portion 17b between the first annular surface portion 171 and the second annular surface portion 172 (that is, the upper end portion of the first annular surface portion 171). Shows the state.

  Then, when the valve body 31 further moves away from the seating position and moves in the direction of the axis P, as shown in FIG. 9, when the vertical line is lowered from the upper end portion 33a of the inclined surface 33 to the seating surface 17A, Even if it comes to be located in the part 17a (namely, the upper end part of the 2nd annular surface part 172), in the valve body 31, the upper end location 33a will be the location nearest to the seating surface 17A. That is, this perpendicular line becomes a boundary line K between the first pressure P1 and the second pressure P2, and even in this state, the second pressure P2 of the secondary port 14 is in the portion inside the upper end portion 33a of the valve body 31. As a result, the area to which the second pressure P2 is applied does not change, and therefore, the balance of the force applied in the direction of the axis P of the valve member 30 is maintained. This perpendicular is also a normal line at the upper end portion 17a of the seating surface 17A.

  After that, the valve body 31 further moves away from the seating position and moves in the direction of the axis P, and as shown in FIGS. 10A and 10B, contrary to the above, from the upper end portion 17a of the seating surface 17A to the inclined surface. Even if the foot of the perpendicular when the perpendicular is lowered to 33 becomes the valve opening upper limit position located at the upper end portion 33a, the upper end portion 33a of the valve body 31 is the closest portion to the seating surface 17A. That is, this perpendicular line becomes the boundary line K between the first pressure P1 and the second pressure P2, and even in this valve open upper limit state, the second side of the secondary port 14 is located in the portion inside the upper end portion 33a of the valve body 31. Since the pressure P2 is applied, the area to which the second pressure P2 is applied does not change, so that the balance of the force applied in the direction of the axis P of the valve member 30 is maintained. This perpendicular is also a normal line at the upper end portion 33 a of the inclined surface 33.

  Then, if the valve element 31 moves further away from the seating position than the valve opening upper limit position and moves in the direction of the axis P, a position on the inclined surface 33 below the upper end portion 33a of the inclined surface 33 as shown in FIG. 33b is the closest location to the seating surface 17A in the valve body 31, and the line connecting the location 33b and the upper end portion 17a of the seating surface 17A is the boundary line K ′ between the first pressure P1 and the second pressure P2. It becomes. Therefore, in this state, the second pressure P2 of the secondary port 14 is applied to a portion of the valve body 31 inside the portion 33b having a diameter larger than the upper end portion 33a. The second pressure P <b> 2 applied to the position increases, thereby changing the balance of the force applied in the direction of the axis P of the valve member 30.

  As described above, in the motor-operated valve 1A of the present embodiment, the valve member 30 (specifically, the valve member 30 within the range in which the second pressure P2 of the secondary port 14 is applied to a portion inside the upper end portion 33a of the valve body 31). By moving the body 31), the balance of the force applied in the direction of the axis P of the valve member 30 can be maintained, and the balance can be prevented from changing. In other words, in the electric valve 1A, the valve member 30 is moved within a range in which a straight line connecting the shortest distance between the valve member 30 (specifically, the annular tip portion 31b) and the seating surface 17A passes through the upper end portion 33a of the valve member 30. Move.

  In the motor-operated valve 1A, the valve member 30 shown in FIG. 10 is set at the valve opening upper limit position, and the valve member 30 is separated from the valve seat portion 16 beyond the valve opening upper limit position as in the first embodiment described above. The movement of the valve member 30 is restricted by the rotation stopper mechanism 70 so as not to be present.

As shown in FIGS. 10A and 10B, the diameter of the upper end portion 17a of the seating surface 17A is D2, the diameter of the boundary portion 17b between the first annular surface portion 171 and the second annular surface portion 172 is D2 ′, The inner diameter of the annular tip 31b of the valve body 31 is D3, the angle between the axis P and the first annular surface portion 171 is α1, the angle between the axis P and the second annular surface portion 172 is α2, and the axis P and the inclined surface. If the angle formed by 33 is β, the moving distance from the seating position to the valve opening upper limit position in the valve member is expressed by the following equation (3).
L = h1 + h2 = (h11 + h12−h13) + h2
= [{(D3-D2) / 2} × tan (90 ° −α2)]
+ [{(D3-D2 ′) / 2} × tan (90 ° −α1)]
− [{(D3-D2 ′) / 2} × tan (90 ° −α2)]
+ [{(D3-D2) / 2} × tan β] (3)

Here, the radius of the diameter D2 (that is, the distance from the axis P to the upper end portion 17a of the seating surface 17A) is R2, and the radius of the diameter D2 ′ (that is, the distance from the axis P to the boundary portion 17b of the seating surface 17A) is R2. ', Assuming that the radius of the inner diameter D3 (that is, the distance from the axis P to the upper end portion 33a of the inclined surface 33) is R3,
L = (R3-R2) / tan α2
+ (R3-R2 ′) / tan α1
-(R3-R2 ') / tan α2
+ (R3-R2) tanβ
= (R3-R2) (1 / tan α2 + tan β)
+ (R3-R2 ′) (1 / tan α1-1 / tan α2)} (4)
It becomes.

Since the moving distance x of the valve member 30 is in the range from 0 to L,
0 ≦ x ≦ (R3−R2) (1 / tan α2 + tan β)
+ (R3-R2 ′) (1 / tan α1-1 / tan α2)} (B)
If the movement distance x is in a range that satisfies the above formula (B), the valve member is within a range in which a straight line connecting the shortest distance between the valve member 30 and the seating surface 17A passes through the upper end portion 33a of the valve member 30. 30 will be moved, and the balance of the force applied to the direction of the axis P of the valve member 30 can be maintained.

  The motor-operated valve 1A according to the second embodiment described above includes the seating surface 17A in which the angle α2 of the second annular surface portion with respect to the axis P is set larger than the angle α1 of the first annular surface portion 171. On the contrary, a configuration (α2 <α1 <β) provided with a seating surface 17B in which the angle α2 is set smaller than the angle α1 as in the motor-operated valve 1B shown in FIG.

  FIG. 13 schematically shows the relationship between the angle of the annular surface portion of the valve seat portion with respect to the axis and the flow rate using a graph.

  In the motor-operated valve 1 according to the first embodiment described above, as shown by a dotted line in FIG. 13, the angle α (α = α1) of the seating surface 17 with respect to the moving distance of the valve member 30 from the valve closing position to the valve opening position. The flow rate increases at a constant rate depending on On the other hand, in the motor-operated valve 1A and motor-operated valve 1B of the second embodiment, as shown by the solid line in FIG. 13, from the valve closed position to the middle, the flow rate is at a constant rate depending on the angle α1 of the first annular surface portion 171. From the middle to the valve opening upper limit position, the flow rate increases at a constant rate depending on the angle α2 of the second annular surface portion 172. Thereby, the change of the flow rate with respect to the moving distance of the valve member 30, that is, the flow rate characteristic can be arbitrarily changed.

  As described above, according to the present embodiment, in addition to the effects of the motor-operated valve 1 of the first embodiment described above, the seating surface 17A has a plurality of tapered first annular surface portions 171 and first angles with different angles with respect to the axis P. Since the two annular surface portions 172 are provided, by adjusting the angles α1 and α2 with respect to the axis P in the first annular surface portion 171 and the second annular surface portion 172, the movement distance of the valve member 30, that is, the valve The flow rate (flow rate characteristic) for the degree of opening can be set easily. In the present embodiment, two annular surface portions are provided, but by providing three or more annular surface portions, it is possible to easily set a finer flow rate characteristic.

  Although the present invention has been described with reference to the preferred embodiment, the flow control valve of the present invention is not limited to the configuration of the above embodiment.

  For example, in each of the embodiments described above, the mortar-shaped inclined surface 33 is provided at the tip 31d of the annular tip 31b of the valve member 30 (specifically, the valve body 31). May be provided, and the outer peripheral surface of the annular tip 31b of the valve body 31 and the lower end surface of the tip 31d of the annular tip 31b may be connected orthogonally. Alternatively, the inclined surface 33 may be a surface having a minute size formed by chamfering.

  Moreover, in each embodiment, although the valve seat part 16, the valve guide 20, and the valve member 30 were each formed in the circular annular shape, the cylindrical shape, and the column shape, it is not limited to this. As long as the shape of the valve seat portion 16, the valve guide 20 and the valve member 30 in a plan view viewed from the direction of the axis P is similar, the shape may be a polygonal shape or the like in addition to the circular shape. Unless it is contrary, the shape of the valve seat part 16, the valve guide 20, and the valve member 30 is arbitrary.

  Moreover, in each embodiment, although it was the motor operated valve which drives a valve member with a stepping motor, it is not limited to this, A flow control valve etc. which drive a valve member manually may be sufficient, and an electromagnetic coil And an electromagnetic valve type in which the valve member is driven by a plunger.

  Further, in each embodiment, the pressure equalizing path 36 that communicates the secondary side port 14 and the back pressure chamber 25 is provided in the valve member 30, but the present invention is not limited to this, and the pressure equalizing path is For example, instead of the valve member 30, the valve body 10 may be provided so that the second opening 12 and the back pressure chamber 25 communicate directly.

  In each embodiment, the primary side joint pipe A1 is the inlet side and the secondary side joint pipe A2 is the outlet side. However, the present invention is not limited to this, and the inlet side and the outlet side are reversed. It may be.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the scope of the present invention. Of course, such modifications are included in the scope of the present invention as long as the configuration of the flow control valve of the present invention is provided.

1 Motorized valve (flow control valve)
10 Valve body (valve housing)
11 1st opening 12 2nd opening 16 Valve seat part 17, 17A Seating surface 171 1st annular surface part (annular surface part)
172 Second annular surface portion (annular surface portion)
17a Upper end of seating surface 18 Tip surface (end of cylinder seat side of valve seat)
20 Valve guide (cylinder part)
25 Back pressure chamber 30 Valve member 31 Valve body 31a Valve body main body 31b Annular tip 33 Inclined surface 33a Upper end location (location in contact with seating surface of valve member)
36 Pressure equalizing path 40 Valve member driving section (valve member moving means)
50 Valve holder 60 Motor 70 Rotation stopper mechanism k, K, K ′ Fluid pressure boundary line P axis angle of seating surface with respect to α axis α1 angle of first annular surface portion with respect to axis α2 angle of second annular surface portion with respect to axis β Angle of inclined surface with respect to axis x Movement distance of valve member in direction of axis P

Claims (5)

A valve housing having a first opening and a second opening; an annular valve seat provided in the valve housing in communication with the second opening; and an axis passing through an axis of the valve seat. A cylinder portion provided in the valve housing in which an axial center is arranged and the valve seat portion and one end portion face each other with a space therebetween, and a valve that is movably accommodated in a piston shape in the cylinder portion The valve housing or the valve so that the member and the back pressure chamber on the other end side in the cylinder portion formed by dividing the space in the cylinder portion into the valve member and the second opening communicate with each other In a flow control valve having a pressure equalizing path provided in a member, and a valve member moving means for moving the valve member so as to be separated and seated with respect to the valve seat portion,
The valve seat portion is provided with a tapered seating surface facing outward that is formed so that the diameter gradually decreases toward the cylinder portion side,
The valve member is provided with an annular tip portion that contacts the seating surface so that an end portion of the valve seat portion on the cylinder portion side is positioned on an inner peripheral side when seated on the valve seat portion. A flow control valve.   The valve member moving means moves the valve member within a range in which a straight line connecting the shortest distance between the annular tip and the seating surface passes through a portion of the annular tip that contacts the seating surface. The flow rate control valve according to claim 1, wherein the flow rate control valve is configured as follows.   3. The flow control valve according to claim 1, wherein an inner diameter of the annular tip portion is the same as an inner diameter of the cylinder portion. On the inner edge of the annular tip, a mortar-shaped inclined surface is provided,
The flow control valve according to claim 1, wherein an angle of the inclined surface with respect to the axis is larger than an angle of the seating surface with respect to the axis.   The flow control valve according to claim 1, wherein the seating surface includes a plurality of tapered annular surface portions having different angles with respect to the axis.

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