JP5701825B2 - Flow control valve - Google Patents

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, such a pressure balance type flow control valve is disclosed in, for example, Japanese Patent Laid-Open No. 2000-320711 (Patent Document 1) and Japanese Patent Laid-Open No. 63-243581 (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. A valve seat portion 813 is provided around the second opening 812. 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.

  Further, in the electric expansion valve 800 described above, since the valve member 804 has a cylindrical shape, only the area S1 of the upper end surface 804b and the area S2 of the lower end surface 804a are taken into account. For example, as shown in FIG. The same applies to the case where the valve member has a shape other than the cylindrical shape.

  In the flow control valve shown in FIG. 15 (indicated by reference numeral 900 in the figure), 901 is a substantially cylindrical valve body, 904 is a substantially columnar valve member, 911 is a first opening, 912 is a second opening, and 913 is A valve seat portion, 915 is a back pressure chamber, and 941 is a pressure equalizing path. Moreover, D1-D6 shows the diameter of each part of the valve member 904, and the following S1-S6 are each in D1-D6 when the valve member 904 is seen from the axial center direction (up-down direction in the figure). The area of the corresponding part is shown.

Assuming that the fluid pressure in the first opening 911 is P1, and the fluid pressure in the second opening 912 is P2, the valve member 904 is illustrated by the force F1 applied upward and the force F2 applied downward in FIG. The force F3 applied in the upward direction and the force F4 applied in the downward direction are expressed by the following equations (ii) to (v).
F1 = P1 ((S1-S3) + (S6-S2)) (ii)
F2 = P1 ((S5-S3) + (S6-S5)) (iii)
F3 = P2 (S2-S4) (iv)
F4 = P2 (S1-S4) (v)

When the upward force is positive, the force F ′ applied to the valve member 904 in the axial direction (vertical direction in the figure) is
F '= (F1-F2) + (F3-F4)
= P1 (S1-S2) -P2 (S1-S2)
= (P1-P2) (S1-S2) (vi)
That is, in the same manner as described above, the portion of the valve member 904 to which fluid pressure is applied at the second opening when the valve is closed is the planar view area S1 of the portion on the back pressure chamber 915 side and the second opening 912 side (valve seat). By making the planar view area S2 of the part on the part 913 side the same (substantially the same), the force applied in the axial direction of the valve member 904 when the valve is closed can be offset or reduced.

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

  However, as shown in FIG. 16A, such a pressure balance type flow control valve 900 has a back pressure chamber 915 side in a portion where the fluid pressure P2 of the second opening 912 is applied when the valve is closed in the valve member 904. The plan view area S1 of the portion and the plan view area S2 of the portion on the second opening 912 side are made equal so that the force applied in the axial direction of the valve member 904 when the valve is closed is offset or reduced. However, as shown in FIG. 16B, when the first opening 911 and the second opening 912 are communicated when the valve is opened, the valve member 904 and the valve seat portion 913 are relatively close to each other. When in position, the line connecting the shortest distance between the valve member 904 and the valve seat portion 913 becomes the boundary line K between the fluid pressure P1 of the first opening 911 and the fluid pressure P2 of the second opening, but the valve member 904 Pull gradually from the valve seat 913 As the axis is moved in the axial direction, the area in plan view of the second opening side portion to which the fluid pressure P2 is applied is reduced from S2 to S2 ′, and therefore the force applied in the axial direction of the valve member 904 is reduced. There is a problem that the balance is lost and a large force is required to move the valve member 904.

  Therefore, the present invention suppresses a change in the balance of the force applied in the axial direction of the valve member 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. It aims at providing the flow control valve which can be performed.

  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 is provided in the valve housing in communication with the second opening. An annular valve seat portion having a seating surface having a shape, and an axis is disposed on an axis passing through the axis of the valve seat portion, and the valve seat portion and the one end portion are opposed to each other with a gap therebetween. A cylinder part provided in the valve housing, a valve member housed in a piston-like manner in the cylinder part so as to be separated from and seated on a seating surface of the valve seat part, and a space in the cylinder part Is a pressure equalization path provided in the valve housing or the valve member so as to communicate the back pressure chamber on the other end side in the cylinder portion formed by the valve member and the second opening. And the shortest distance between the valve member and the seating surface The department straight line has a valve member moving means for moving the valve member to the extent that a state of passing through a portion in contact with the seating surface of the valve member which is a flow rate control valve according to claim.

  According to a second aspect of the present invention, in the first aspect of the present invention, a tapered surface is provided at an end of the valve member on the valve seat portion side, and the tapered surface of the valve member with respect to the axis is provided. The angle is larger than the angle of the seating surface with respect to the axis.

  The invention described in claim 3 is the invention described in claim 1 or 2, characterized in that the seating surface has a plurality of mortar-shaped annular surface portions having different angles with respect to the axis. To do.

  According to the present invention, in the pressure balance type flow control valve in which the back pressure chamber and the second opening communicate with each other by the pressure equalizing passage, a straight line connecting the shortest distance between the valve member and the seating surface is the seating surface of the valve member. Since the valve member moving means for moving the valve member within a range that passes through the location in contact with the valve member, when the valve member is moved within such a range, the location in contact with the seating surface of the valve member is Therefore, the boundary between the fluid pressure on the first opening side and the fluid pressure on the second opening side is generated between the location and the seating surface. 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 valve member from the location, so the second opening side portion of the valve member where the fluid pressure of the second opening is applied. The plan view area does not change, and the balance of the force applied in the axial direction of the valve member when the valve member in the valve closed state is moved away from the valve seat in the axial direction is prevented from changing. it can.

  According to the invention described in claim 2, a tapered surface is provided at the end of the valve member on the valve seat portion side, and the angle of the tapered surface of the valve member with respect to an axis passing through the axis of the valve seat portion is Since it is larger than the angle of the seating surface with respect to the axis, the end of the valve member on the side opposite to the valve seat portion side of the taper surface can be made a location in contact with the seating surface of the valve member, ensuring a pressure balance. Can be maintained.

  According to the invention described in claim 3, since the seating surface has a plurality of mortar-shaped annular surface portions having different angles with respect to the axis, by adjusting the angle with respect to the axis in each annular surface portion, 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 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 which a valve member is in a valve open upper limit position (valve open upper limit state). 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. It is an expanded sectional view showing other conventional flow control valves typically. It is an expanded sectional view showing typically the flow control valve of Drawing 15, (a) is a figure showing a valve closed state, and (b) is a figure showing a valve open state.

(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 has a single mortar-shaped seating surface 17 whose inner diameter gradually decreases from the top to the bottom, and a valve seat inner peripheral surface 18 connected to the lower end of the seating surface 17. ing. The seating surface 17 contacts the valve member 30 when a later-described valve member 30 is seated on the valve seat portion 16. Further, the valve seat inner circumferential surface 18 is formed to have substantially the same diameter as the inner diameter of the secondary side joint pipe A2, and demarcates 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 21 is fixedly mounted in the valve main body 10 such that the lower end 21a and the valve seat 16 are opposed to each other with a space therebetween. 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.

  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 is formed in a substantially cylindrical shape in which the lower end portion 31 a is opened and the upper end portion 31 b is closed by the upper wall 32. The valve body 31 is disposed so that its outer peripheral surface 31 c is slidably in contact with the inner peripheral surface 21 c of the valve guide main body 21. The lower end portion 31a of the valve body 31 is provided with a tapered valve body taper surface 33 whose diameter decreases toward the lower side.

  The connection fitting 34 is formed in a substantially cylindrical shape having an outer diameter smaller than that 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 connecting fitting 34 is attached to the upper wall 32 of the valve body 31 by passing through the upper wall 32 and being fixed. As a result, the inner space of the valve body 31, the inner space of the coupling fitting 34, and the through hole 34 d are communicated with each other to form a pressure equalizing path 36. The pressure equalization path 36 communicates the space below the valve body 31 and the back pressure chamber 25.

  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 portion 37 is sandwiched between the flange portion 34 e of the connecting fitting 34 and the upper surface 31 d of the valve body 31 together with the disc spring receiver 38 and the disc spring 39.

  The second opening 12, the valve seat portion 16, the valve guide 20, and the valve member 30 are arranged such that the respective axis centers are positioned on the axis 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 52 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 valve body taper 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 valve body taper surface 33 with respect to the axis P is set to β larger than the angle α (where α < β <90 degrees).

  Further, the outer diameter of the valve body 31 is set to D1, and the diameter of the upper end portion 17a of the seating surface 17 is set to D2 larger than the outer diameter D1. Thereby, when the valve body 31 is in the seating position (valve closed state) where the valve body 31 is seated on the valve seat portion 16, the upper end portion 33a of the valve body taper surface 33 is in contact with the seating surface 17, and the secondary port 14 is closed. It is done. That is, the upper end portion 33 a is a portion in contact with the seating surface 17 in 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, and therefore, in the valve closed state, the secondary port 14 is provided at a portion inside the upper end portion 33a of the valve body 31. The fluid pressure (second pressure P2) is applied.

  Next, when the valve body 31 is moved away from the seating position and gradually moved in the direction of the axis P, the upper end portion 33a of the valve body 31 is maintained at the position closest to the seating surface 17 as shown in FIG. Move while. In other words, the straight line connecting the shortest distance between the valve member 30 and the seating surface 17 moves while maintaining a state where it 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, 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, and the balance of the force applied in the axis P direction of the valve member 30 is maintained. The When the valve member 30 is in such a half-opened valve position, when a perpendicular is drawn from the upper end portion 33 a of the valve body taper surface 33 to the seating surface 17, the perpendicular foot is located on the seating surface 17. This perpendicular becomes the boundary line k.

When the moving distance from the seating position in the valve member 30 to the valve half-open position is x, the distance y between the upper end portion 33a of the valve body taper surface 33 and the seating surface 17 is expressed by the following equation (1):
y = xsinα (1)
As the moving distance x from the seating position of the valve member 30 increases, the distance y between the upper end portion 33a of the valve body taper surface 33 and the seating surface 17 increases.

  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. 4, when the vertical line is lowered from the upper end portion 33 a of the valve body taper surface 33 to the seating surface 17, Even when the upper end portion 17 a is positioned, the upper end portion 33 a of the valve body 31 is the closest portion 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. In addition, 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, 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, a perpendicular is dropped from the upper end portion 17 a of the seating surface 17 to the valve body taper surface 33. The upper end portion 33a of the valve body 31 is the closest portion to the seating surface 17 even when the perpendicular foot 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. The pressure P2 is applied, and 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 valve body tapered surface 33.

  Then, if the valve body 31 further moves away from the seating position in the axis P direction from the valve opening upper limit position, the valve body taper surface below the upper end portion 33a of the valve body taper surface 33 as shown in FIG. A position 33b on 33 is the closest position to the seating surface 17 in the valve body 31, and a line connecting the location 33b and the upper end portion 17a of the seating surface 17 is a relationship between the first pressure P1 and the second pressure P2. This is the boundary line K ′. Therefore, in this state, the second pressure P2 of the secondary port 14 is applied to a portion inside the portion 33b having a diameter smaller than the upper end portion 33a in the valve body 31, and the primary side is applied to a portion outside the portion 33b. When the first pressure P1 of the port 13 is applied, the balance of the force applied to the valve member 30 in the direction of the axis P changes.

  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 and the seating surface 17 passes through the upper end portion 33 a of the valve member 30.

  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 outer diameter of the valve body 31 is D1, the diameter of the upper end portion 17a of the seating surface 17 is D2, the angle between the axis P and the seating surface 17 is α, the axis P and the valve body taper surface 33 If the angle formed by β is β, the moving distance L from the seating position to the valve opening upper limit position in the valve member 30 is expressed by the following equation (2).
L = h1 + h2
= [{(D2-D1) / 2} × tan (90-α)]
+ [{(D2-D1) / 2} × tan β] (2)

Here, the radius of the outer diameter D1 (that is, the distance from the axis P to the upper end portion 33a of the valve body tapered surface 33) is R1, and 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). Let R2 be
L = (R2-R1) / tan α + (R2-R1) tan β
= (R2-R1) (1 / tan α + tan β) (3)
It becomes.

Since the moving distance x of the valve member 30 is in the range from 0 to L,
0 ≦ x ≦ (R2−R1) (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 is provided with a valve body 10 in which a first opening 11 and a second opening 12 are formed, and in the valve body 10 so as to communicate with the second opening 12, and a mortar-shaped seating surface 17. And the valve body 10 so that the valve seat portion 16 and the lower end portion 21a face each other with a space therebetween. A valve guide 20 provided therein, a valve member 30 movably accommodated in a piston-like manner in the valve guide 20 so as to be separated from and seated on a seating surface 17 of the valve seat portion 16, and a valve guide 20 The pressure equalization provided in the valve member 30 so that the back pressure chamber 25 on the upper end portion 21b side and the second opening 12 in the valve guide 20 formed by dividing the inner space into the valve member 30 communicate with each other. A straight line connecting the shortest distance between the path 36 and the valve member 30 and the seating surface 17 is a valve member. Has a valve member driver 40 for moving the valve member 30 to the extent that a state of passing through the upper end portion 33a of the valve body taper surface 33 of 0, the.

  Further, the motor-operated valve 1 is provided with a valve body taper surface 33 at the end of the valve member 30 on the valve seat portion 16 side, and an angle β of the valve body taper surface 33 with respect to the axis P is such that the seat surface 17 with respect to the axis P It is made larger than the angle α.

  As described above, according to the present embodiment, in the pressure balance type motor-operated 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, the shortest distance between the valve member 30 and the seating surface 17 is connected. Since the straight line has the valve member driving unit 40 that moves the valve member 30 within a range passing through the upper end portion 33a of the valve body tapered surface 33 of the valve member 30, the valve member 30 is moved within such a range. In this case, the upper end portion 33a of the valve body taper surface 33 of the valve member 30 is always closest to the seating surface 17, and therefore, the fluid pressure (the first opening 11 side) between the upper end portion 33a and the seating surface 17 (first 1 pressure P1) and the fluid pressure (2nd pressure P2) of the 2nd opening 12 side arise. Thereby, even if the valve member 30 is moved, the second pressure P2 of the second opening 12 is always applied to the portion inside the upper end portion 33a of the valve member 30, so that the second of the second opening 12 of the valve member 30 is second. The area in plan view of the portion on the second opening 12 side to which the pressure P2 is applied does not change, and the valve member 30 is moved when 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. It is possible to suppress a change in the balance of the force applied in the direction of the axis P.

  Further, a valve body taper surface 33 is provided at an end of the valve member 30 on the valve seat portion 16 side (lower end portion 31 a of the valve body 31), and the valve body taper surface with respect to an axis P passing through the axis of the valve seat portion 16. Since the angle β of 33 is larger than the angle α of the seating surface 17 with respect to this axis P, when the tip (lower end portion 31a) of the valve member 30 is inside the valve seat portion 16, the valve body tapered surface 33 A flow path is formed by the seating surface 17 and the fluid flow can be adjusted. Further, the upper end portion 33 a of the valve body tapered surface 33 of the valve member 30 can be a portion that contacts the seating surface 17 in the valve member 30.

(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 the valve member is in the valve open upper limit position (valve open upper limit state). . 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.

  The motor-operated valve 1A of the second embodiment is the motor-operated valve 1 of the first embodiment described above, in which the valve seat portion 16 is replaced with a single mortar-shaped seating surface 17 and has a plurality of angles different from each other with respect to the axis P. Since it is the same as the motor-operated valve 1 of 1st Embodiment except having the seating surface 17A provided with the mortar-shaped annular surface part, the same code | symbol is attached | subjected and demonstrated to the same part. Omitted.

  On the seating surface 17A of the valve seat portion 16, two mortar-shaped first annular surface portions 171 and second annular surface portions 172 having different angles with respect to the axis P are provided. 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.

  In the motor-operated valve 1 </ b> A, a seating surface 17 </ b> A including a first annular surface portion 171 and a second annular surface portion 172 is provided on the valve seat portion 16, and a valve body tapered surface 33 is provided on the valve body 31. Further, as shown in FIG. 7, the angle of the first annular surface portion 171 near the valve seat inner peripheral surface 18 with respect to the axis P is set to α1, and the second annular surface separated from the valve seat inner peripheral surface 18 with respect to the axis P The angle of the portion 172 is set to α2 that is 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 valve body taper surface with respect to the axis P (where α1 <α2 <β <90 degrees).

  Further, the outer diameter of the valve body 31 is set to D1, the diameter of the boundary portion 17b between the first annular surface portion 171 and the second annular surface portion 172 is set to D2 larger than the outer diameter D1, and the seating surface 17A The diameter of the upper end portion 17a is set to D3 that is larger than the outer 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 33a of the valve body taper surface 33 is in contact with the first annular surface portion 171 of the seating surface 17A. The secondary port 14 is closed. That is, the upper end portion 33a is a portion that contacts the seating surface 17A 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.

  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 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, 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, and the balance of the force applied in the axis P direction of the valve member 30 is maintained. The When the valve member 30 is in a position where such a valve is in a half-open state, when a vertical line is lowered from the upper end portion 33a of the valve body taper surface 33 to the seating surface 17A, the perpendicular foot is moved to the seating surface 17A (in this case, the first surface The two annular surface portions 172 are 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 in the direction of the axis P away from the seating position, and the perpendicular line is lowered from the upper end portion 33a of the valve body taper surface 33 to the seating surface 17A, as shown in FIG. Even when the upper end portion 17a (that is, the upper end portion of the second annular surface portion 172) is positioned, 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 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. In addition, 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.

  Thereafter, the valve body 31 further moves away from the seating position and moves in the direction of the axis P. As shown in FIG. 10, the vertical line is lowered from the upper end portion 17a of the seating surface 17A to the valve body taper surface 33, as shown in FIG. The upper end portion 33a of the valve body 31 is the closest to the seating surface 17A 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. The pressure P2 is applied, and 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 valve body tapered surface 33.

  Then, if the valve body 31 moves further away from the seating position in the axis P direction than the valve opening upper limit position, the valve body taper surface below the upper end portion 33a of the valve body taper surface 33 as shown in FIG. The position 33b on 33 is the position closest 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 first pressure P1 and the second pressure P2. This is the boundary line K ′. Therefore, in this state, the second pressure P2 of the secondary port 14 is applied to a portion inside the portion 33b having a diameter smaller than the upper end portion 33a in the valve body 31, and the primary side is applied to a portion outside the portion 33b. When the first pressure P1 of the port 13 is applied, the balance of the force applied to the valve member 30 in the direction of the axis P changes.

  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 motor operated 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 and the seating surface 17A passes through the upper end portion 33a of the valve member 30.

  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 FIG. 10, the outer diameter of the valve body 31 is D1, the diameter of the boundary portion 17b of the seating surface 17A is D2, the diameter of the upper end portion of the seating surface 17A is D3, and the axis P and the first annular surface portion 171 Assuming that the angle formed by α1 is the angle formed by the axis P and the second annular surface portion 172 is α2, and the angle formed by the axis P and the valve body taper surface 33 is β, the seating position of the valve member to the valve opening upper limit position. The movement distance is expressed by the following equation (4).
L = h1 + h2 = (h11 + h12−h13) + h2
= [{(D3-D1) / 2} × tan (90-α2)]
+ [{(D2−D1) / 2} × tan (90−α1)]
− [{(D2-D1) / 2} × tan (90−α2)]
+ [{(D3-D1) / 2} × tan β] (5)

Here, the radius of the outer diameter D1 (that is, the distance from the axis P to the upper end portion 33a of the valve body tapered surface 33) is R1, 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, and the radius of the diameter D3 (that is, the distance from the axis P to the upper end portion 17a of the seating surface 17A) is R3,
L = (R3-R1) / tan α2
+ (R2-R1) / tan α1
-(R2-R1) / tan α2
+ (R3-R1) tan β
= (R3-R1) (1 / tan α2 + tan β)
+ (R2-R1) (1 / tan α1-1 / tan α2)} (6)
It becomes.

Since the moving distance x of the valve member 30 is in the range from 0 to L,
0 ≦ x ≦ (R3−R1) (1 / tan α2 + tan β)
+ (R2-R1) (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.

  In the motor-operated valve 1A of the second embodiment described above, the angle α2 of the second annular surface portion with respect to the axis P is set to be larger than the angle α1 of the first annular surface portion 171. In addition, the angle α2 may be 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 mortar-shaped first annular surface portions 171 and the first angular surface portions 171 having 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.

  In each of the embodiments described above, the valve body taper surface 33 is provided at the lower end portion 31a of the valve member 30 (specifically, the valve body 31). However, such a valve body taper surface 33 is not provided. Alternatively, the outer peripheral surface of the valve body 31 and the lower end surface of the valve body 31 may be connected orthogonally. Alternatively, the valve body taper surface 33 may be a minute taper surface 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.

  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 is provided in the valve main body 10 instead of the valve member 30. May be.

  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, various modifications can be made without departing from the scope of the present invention.

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 20 Valve guide (cylinder part)
25 Back pressure chamber 30 Valve member 31 Valve body 33 Valve body taper surface (taper 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 P Axis line R1 Distance from the axis line to the upper end of the valve body taper surface R2 Distance from the axis line to the upper end of the seating surface Angle of the seating surface with respect to the α axis First α surface portion with respect to the α1 axis The angle of the second annular surface portion with respect to the axis α2 The angle of the valve body tapered surface with respect to the β axis x The movement distance of the valve member in the direction of the axis P

Claims (3)

A valve housing having a first opening and a second opening;
An annular valve seat portion provided in the valve housing in communication with the second opening and having a mortar-shaped seating surface;
A cylinder portion provided in the valve housing such that an axis is disposed on an axis passing through the axis of the valve seat portion, and the valve seat portion and one end portion thereof are opposed to each other with a space therebetween;
A valve member housed in a piston-like manner in the cylinder portion so as to be separated from and seated on the seating surface of the valve seat portion;
The valve housing or the valve member is provided so that 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. Equalized pressure path,
Valve member moving means for moving the valve member within a range in which a straight line connecting the shortest distance between the valve member and the seating surface passes through a portion of the valve member in contact with the seating surface. A flow control valve characterized by comprising: A tapered surface is provided at an end of the valve member on the valve seat portion side,
The flow control valve according to claim 1, wherein an angle of the tapered surface of the valve member 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 has a plurality of mortar-shaped annular surface portions having different angles with respect to the axis.

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