Electric valve

Abstract

To provide a motor valve capable of having a desired flow characteristics without depending on the shape of a valve element.SOLUTION: A control device 200 stores pulse number information regarding pulse numbers assigned to the valve element sequentially from its valve closing position to its fully opening position, and step angle information regarding step angles corresponding to the respective pulse numbers. The control device 200 acquires the pulse numbers corresponding to valve element moving orders to rotate a stepping motor at the step angles corresponding to the pulse numbers in sequence of the pulse numbers. Between a reference position to the fully opening position of the valve element, a first section, a second section, and a third section are set. In the first section, a step angle for a micro-step operation obtained by multiplying a full-step operation by 1 / n is set, in the second section, a step angle for a micro-step operation obtained by multiplying the full-step operation by 1 / m is set, and in the third section, a step angle for the full-step operation is set.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a motor-operated valve used in, for example, the refrigeration cycle of an air conditioner. [Background technology]

[0002] Patent Document 1 discloses a conventional motor-operated valve. The motor-operated valve of Patent Document 1 has a valve element and a stepping motor. The valve element is disposed opposite to the valve orifice. The valve element is moved in the direction opposite to the valve orifice by the rotation of the stepping motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-268030 Summary of the Invention [Problem to be solved by the invention]

[0004] In the motor-operated valve described above, the stepping motor rotates in response to pulses. The rotation angle (step angle) per pulse of the stepping motor is constant, and the amount of movement of the valve disc per pulse is also constant. Therefore, the flow characteristics of the motor-operated valve depend on the shape of the valve disc, and in order to obtain the desired flow characteristics, it was necessary to use a valve disc with a shape that corresponds to the flow characteristics.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a motor-operated valve that can obtain desired flow characteristics regardless of the shape of the valve body. [Means for solving the problem]

[0006] In order to achieve the above object, the motor-operated valve of the present invention is an electric valve having a valve body with a valve port, a valve element arranged opposite the valve port, a drive mechanism that moves the valve element in a direction opposite the valve port, and a control device that controls the drive mechanism, wherein the drive mechanism has a stepping motor and moves the valve element by rotating the stepping motor, and the control device has a memory unit that stores pulse number information regarding pulse numbers assigned in sequence from a reference position to a fully open position of the valve element and step angle information regarding step angles corresponding to each of the pulse numbers, a communication unit that receives a valve element movement command regarding a target position of the valve element from an external device, a calculation unit that acquires the pulse numbers assigned from the current position of the valve element to the target position of movement, and a rotation control unit that rotates the stepping motor by the step angle corresponding to each pulse number in the order of the pulse numbers assigned from the current position of the valve element to the target position of movement.

[0007] In the present invention, it is preferable that a first section, a second section, and a third section are set between the reference position and the fully open position of the valve body, a first angle is set to the step angle corresponding to the pulse number assigned to the first section, a second angle is set to the step angle corresponding to the pulse number assigned to the second section, and a third angle is set to the step angle corresponding to the pulse number assigned to the third section, and the first angle, the second angle, and the third angle are different from one another.

[0008] In the present invention, it is preferable that the first angle is a step angle in microstep operation obtained by dividing a full-step operation of the stepping motor by n, the second angle is a step angle in microstep operation obtained by dividing a full-step operation of the stepping motor by m, and the third angle is a step angle in full-step operation of the stepping motor, where m and n are natural numbers of 2 or greater and m ≠ n.

[0009] In the present invention, it is preferable that the valve body has a tapered surface whose diameter decreases toward the valve port, and when the valve body is in the first section, the second section, or the third section, the flow rate is determined by the gap between the tapered surface and the inner surface of the valve port.

[0010] In the present invention, it is preferable that the pulse speed when the valve element is in the first section is n times the pulse speed when the valve element is in the third section, and the pulse speed when the valve element is in the second section is m times the pulse speed when the valve element is in the third section.

[0011] In the present invention, it is preferable that a first section and a second section are set between the reference position and the fully open position of the valve body, a first angle is set to the step angle corresponding to the pulse number assigned to the first section, and a second angle is set to the step angle corresponding to the pulse number assigned to the second section, and the first angle and the second angle are different.

[0012] In the present invention, it is preferable that the first angle is a step angle in microstep operation obtained by dividing a full-step operation of the stepping motor by n, and the second angle is a step angle in the full-step operation of the stepping motor, where n is a natural number of 2 or more.

[0013] In the present invention, it is preferable that the valve body has a tapered surface whose diameter decreases toward the valve port, and when the valve body is in the first section or the second section, the flow rate is determined by the gap between the tapered surface and the inner surface of the valve port.

[0014] In the present invention, it is preferable that the pulse speed when the valve element is in the first section is n times the pulse speed when the valve element is in the second section.

[0015] In the present invention, it is preferable that the memory unit stores start-up state pulse number information regarding pulse numbers assigned in order from the reference position to the fully open position of the valve disc, start-up state step angle information regarding step angles corresponding to each of the pulse numbers in the start-up state pulse number information, normal operation state pulse number information regarding pulse numbers assigned in order from the reference position to the fully open position of the valve disc, and normal operation state step angle information regarding step angles corresponding to each of the pulse numbers in the normal operation state pulse number information, and that the control device uses the start-up state pulse number information and the start-up state step angle information as the pulse number information and the step angle information in the start-up state, and uses the normal operation state pulse number information and the normal operation state step angle information as the pulse number information and the step angle information in the normal operation state after the start-up state.

[0016] In the present invention, it is preferable that the control device transitions to the normal operation state when the communication unit receives a normal operation start command from an external device while in the startup state.

[0017] In the present invention, it is preferable that the control device transitions to the normal operating state when the valve body moves to a predetermined start-up completion position in the start-up state. [Effects of the Invention]

[0018] According to the present invention, a control device for a motor-operated valve stores pulse number information regarding pulse numbers assigned in order from a reference position to a fully open position of the valve disc, and step angle information regarding step angles corresponding to each pulse number. The control device receives a valve disc movement command regarding a target position of the valve disc from an external device. The control device acquires the pulse numbers assigned to the valve disc from its current position to the target position. The control device then rotates the stepping motor by the step angle corresponding to each pulse number in the order of the pulse numbers assigned to the valve disc from its current position to the target position. This allows the motor-operated valve to individually set the step angle for each pulse assigned to the valve disc from its reference position to the fully open position, and adjust the amount of valve disc movement per pulse (i.e., the amount of change in the flow rate of refrigerant flowing through the valve port). As a result, the motor-operated valve can obtain desired flow characteristics regardless of the shape of the valve disc. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view of a motor-operated valve according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a stator unit of the motor-operated valve of FIG. 1. [Figure 3] 2 is an enlarged cross-sectional view of the valve disc and its vicinity when the valve disc of the motor-operated valve of FIG. 1 is in a valve-closed position. FIG. [Figure 4] 2 is an enlarged cross-sectional view of the valve disc and its vicinity when the valve disc of the motor-operated valve of FIG. 1 is in a fully open position. FIG. [Figure 5] 2 is a graph showing the relationship between the valve opening and the flow rate in the motor-operated valve of FIG. 1. [Figure 6] 2 is a diagram illustrating the positional relationship between the magnet rotor and the stator of the motor-operated valve of FIG. 1. FIG. [Figure 7] FIG. 2 is a functional block diagram of the motor-operated valve of FIG. 1. [Figure 8] 2 is a diagram showing a table relating to pulse number information and step angle information stored in the control device of the motor-operated valve of FIG. 1. FIG. [Figure 9]9 is a diagram illustrating the relationship between pulse numbers assigned to the valve closed position to the fully open position and the valve disc position, as shown in the table of FIG. 8. FIG. [Figure 10] 9 is a graph showing the relationship between the position of the valve element and the flow rate when the stepping motor of the motor-operated valve of FIG. 1 rotates based on the table of FIG. 8. [Figure 11] FIG. 9 is a diagram showing a modification of the table in FIG. 8. [Figure 12] 12 is a diagram illustrating the relationship between pulse numbers assigned to the valve closed position to the fully open position and the valve disc position, as shown in the table of FIG. 11. FIG. [Figure 13] 12 is a graph showing the relationship between the position of the valve element and the flow rate when the stepping motor of the motor-operated valve of FIG. 1 rotates based on the table of FIG. 11. [Figure 14] FIG. 9 is a diagram showing another modified example of the table in FIG. 8. [Figure 15] 15 is a diagram illustrating the relationship between pulse numbers assigned to the valve closed position to the fully open position and the valve disc position, as shown in the table of FIG. 14. FIG. [Figure 16] 15 is a graph showing the relationship between the position of the valve element and the flow rate when the stepping motor of the motor-operated valve of FIG. 1 rotates based on the table of FIG. 14. DETAILED DESCRIPTION OF THE INVENTION

[0020] (Example) An electric valve 1 according to one embodiment of the present invention will be described below with reference to Figures 1 to 10. The electric valve 1 is incorporated into the refrigeration cycle of an air conditioner, for example, and operates in response to commands from a control unit 400 of the air conditioner. The control unit 400 is an external device located outside the electric valve 1.

[0021] FIG. 1 is a cross-sectional view of a motor-operated valve according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a stator unit of the motor-operated valve of FIG. 1. FIGS. 3 and 4 are enlarged cross-sectional views of the valve disc and its vicinity of the motor-operated valve of FIG. 1. FIG. 3 shows the valve disc in the closed position. FIG. 4 shows the valve disc in the fully open position. FIG. 5 is a graph showing the relationship between the valve opening and flow rate in the motor-operated valve of FIG. 1. FIG. 6 is a diagram explaining the positional relationship between the magnet rotor and stator of the motor-operated valve of FIG. 1. FIG. 6A shows a state in which the magnetic poles of the magnet rotor face the pole teeth of the A-phase stator. FIG. 6B shows a state in which the magnetic poles of the magnet rotor face the pole teeth of the B-phase stator. FIG. 7 is a functional block diagram of the motor-operated valve of FIG. 1. FIG. 8 is a diagram showing a table of pulse number information and step angle information stored in the control device of the motor-operated valve of FIG. 1. FIG. 9 is a diagram explaining the relationship between the pulse numbers assigned from the closed position to the fully open position and the valve disc position, as shown in the table of FIG. 8. FIG. 10 is a graph showing the relationship between the position of the valve element and the flow rate when the stepping motor of the motor-operated valve of FIG. 1 rotates based on the table of FIG.

[0022] As shown in FIGS. 1 and 2, the motor-operated valve 1 includes a valve body 10, a can 20, a drive mechanism 30, and a valve element 40.

[0023] The valve body 10 is made of a metal such as an aluminum alloy. The valve body 10 includes a body member 11, a support member 12, and a connecting member 13. The body member 11 has a rectangular parallelepiped shape. The body member 11 has a valve chamber 14 and flow paths 15 and 16. The flow path 15 is connected to the valve chamber 14. The flow path 16 is connected to the valve chamber 14 via a valve port 17. The valve port 17 is surrounded by a ring-shaped valve seat 18 in the valve chamber 14. An attachment hole 11a that communicates with the valve chamber 14 is formed in the upper surface of the body member 11. The support member 12 has a cylindrical shape. The support member 12 is attached to the attachment hole 11a of the body member 11 using a threaded structure. The upper part of the support member 12 protrudes from the upper surface of the body member 11. The connecting member 13 has an annular plate shape. The inner peripheral edge of the connecting member 13 is joined to the upper end of the support member 12.

[0024] The can 20 is made of a metal such as stainless steel. The can 20 has a cylindrical shape with an open bottom end and a closed top end. The bottom end of the can 20 is joined to the outer periphery of the connecting member 13.

[0025] The drive mechanism 30 moves the valve element 40 in the vertical direction (the direction of the axis L). The drive mechanism 30 has a magnet rotor 31, a valve stem holder 32, a guide bush 33, a valve stem 34, a permanent magnet 38, and a stator unit 50.

[0026] The magnet rotor 31 has a cylindrical shape. The outer diameter of the magnet rotor 31 is slightly smaller than the inner diameter of the can 20. A plurality of north poles and a plurality of south poles are formed on the outer peripheral surface of the magnet rotor 31. The plurality of north poles and a plurality of south poles extend in the vertical direction. The plurality of north poles and a plurality of south poles are alternately arranged at equal angular intervals in the circumferential direction. In this embodiment, the magnet rotor 31 has 12 north poles and 12 south poles. The angle between adjacent north poles and south poles is 15 degrees.

[0027] The valve stem holder 32 has a cylindrical shape with an open lower end and a closed upper end. A support ring 35 is fixed to the upper end of the valve stem holder 32. The support ring 35 connects the magnet rotor 31 and the valve stem holder 32. A female thread 32c is formed on the inner circumferential surface of the valve stem holder 32.

[0028] The guide bush 33 has a base 33a and a valve stem support portion 33b. The base 33a and the valve stem support portion 33b have a cylindrical shape. The base 33a is press-fitted into a fitting hole 12a formed in the support member 12. The outer diameter of the valve stem support portion 33b is smaller than the outer diameter of the base 33a. The inner diameter of the valve stem support portion 33b is the same as the inner diameter of the base 33a. The valve stem support portion 33b is coaxially connected to the upper end portion of the base 33a. A male thread 33c is formed on the outer peripheral surface of the valve stem support portion 33b. The male thread 33c is threadedly engaged with the female thread 32c of the valve stem holder 32. The guide bush 33 is connected to the support member 12.

[0029] The valve stem 34 has a large diameter portion 34a and a small diameter portion 34b. The large diameter portion 34a and the small diameter portion 34b are cylindrical. The outer diameter of the large diameter portion 34a is slightly smaller than the inner diameter of the guide bush 33. The outer diameter of the small diameter portion 34b is smaller than the outer diameter of the large diameter portion 34a. The small diameter portion 34b is coaxially connected to the upper end of the large diameter portion 34a. The small diameter portion 34b penetrates the valve stem holder 32. A push nut 36 is attached to the small diameter portion 34b to prevent it from coming off. The valve stem 34 is disposed inside the guide bush 33 and the support member 12. The valve stem 34 is supported by the guide bush 33 so as to be slidable in the up and down direction. The lower end of the valve stem 34 is disposed in the valve chamber 14. A step portion 34c is formed on the valve stem 34 between the large diameter portion 34a and the small diameter portion 34b. The step portion 34c is an annular flat surface facing upward. A valve-closing spring 37 is disposed between the valve stem holder 32 and the step portion 34c. The valve-closing spring 37 is a compression coil spring. The valve-closing spring 37 presses the valve stem 34 downward.

[0030] The permanent magnet 38 is disposed inside the can 20 and above the magnet rotor 31. The permanent magnet 38 has a circular flat plate shape. The permanent magnet 38 has one north pole and one south pole. The north pole is disposed on one portion of the permanent magnet 38 defined by a diameter, and the south pole is disposed on the other portion. The permanent magnet 38 is fixed to the support ring 35 via a fixture 39. The permanent magnet 38 rotates together with the magnet rotor 31.

[0031] The valve disc 40 is integrally connected to the lower end of the large diameter portion 34a of the valve stem 34. The valve disc 40 is disposed in the valve chamber 14. The valve disc 40 faces the valve port 17 in the vertical direction. The valve disc 40 has a tapered surface 41 whose diameter gradually decreases toward the valve port 17. The tapered surface 41 extends in the direction of the axis L from near the lower end of the large diameter portion 34a of the valve stem 34 to the tip 40a of the valve disc 40. The vertical direction is the direction in which the valve disc 40 faces the valve port 17. The valve disc 40 may have multiple tapered surfaces with different taper angles.

[0032] The valve element 40 is moved in the vertical direction by the drive mechanism 30. The movement of the valve element 40 opens and closes the valve port 17. Specifically, the valve element 40 is moved from a closed position P1 (FIG. 3) where the tapered surface 41 contacts the valve seat 18 to a fully open position P2 (FIG. 4) where the vertical position of the tip 40a of the valve element 40 is the same as the vertical position of the valve seat 18. The closed position P1 is a reference position. In the motor-operated valve 1, the flow rate of the refrigerant flowing through the valve port 17 is determined by the size of the annular gap formed between the tapered surface 41 and the inner circumferential surface of the valve port 17.

[0033] The graph in FIG. 5 shows the relationship between the valve opening and flow rate in the motor-operated valve 1. The valve opening indicates the position of the valve disc 40 relative to the valve seat 18 (lift amount from the closed valve position P1) and is expressed as a percentage, with 0% when the valve disc 40 is in the closed valve position P1 and 100% when it is in the fully open position P2. The flow rate indicates the flow rate of refrigerant flowing through the motor-operated valve 1 (valve port 17) and is expressed as a percentage, with the Cv value when the valve disc 40 is in the closed valve position P1 being 0% and the Cv value when it is in the fully open position P2 being 100%. As shown in FIG. 5, the basic flow rate characteristic of the motor-operated valve 1 (valve disc 40) is a linear characteristic in which the flow rate changes linearly in proportion to the valve opening. Note that the valve disc 40 may have a shape such that the basic flow rate characteristic is an equal percentage characteristic.

[0034] The stator unit 50 includes a stator 60 , a housing 70 , a case 80 , a main board 90 , a sub-board 100 , a magnetic sensor 110 , and a microcomputer 120 .

[0035] The stator 60 has a cylindrical shape and includes an A-phase stator 61, a B-phase stator 62, and a mold 63 made of synthetic resin.

[0036] The A-phase stator 61 has a plurality of claw-pole-shaped pole teeth 61a, 61b on its inner circumferential side. The tips of the pole teeth 61a face downward, and the tips of the pole teeth 61b face upward. The pole teeth 61a and 61b are alternately arranged at equal angular intervals in the circumferential direction. In this embodiment, the A-phase stator 61 has 12 pole teeth 61a and 12 pole teeth 61b. The angle between adjacent pole teeth 61a and 61b is 15 degrees. When the coil 61c of the A-phase stator 61 is energized, the pole teeth 61a and 61b have opposite polarities.

[0037] The B-phase stator 62 has a plurality of claw-pole-shaped pole teeth 62a, 62b on its inner circumferential side. The tips of the pole teeth 62a face downward, and the tips of the pole teeth 62b face upward. The pole teeth 62a and 62b are alternately arranged at equal angular intervals in the circumferential direction. In this embodiment, the B-phase stator 62 has 12 pole teeth 62a and 12 pole teeth 62b. The angle between adjacent pole teeth 62a and 62b is 15 degrees. When the coil 62c of the B-phase stator 62 is energized, the pole teeth 62a and 62b have opposite polarities.

[0038] The A-phase stator 61 and the B-phase stator 62 are arranged coaxially. The A-phase stator 61 and the B-phase stator 62 are in contact with each other. When viewed from the direction of the axis L, the angle between the pole teeth 61a of the A-phase stator 61 and the pole teeth 62a of the B-phase stator 62, which are adjacent to each other, is 7.5 degrees.

[0039] The mold 63 is filled inside the A-phase stator 61 and the B-phase stator 62. The mold 63, together with the pole teeth 61a, 61b and the pole teeth 62a, 62b, constitutes the stator inner peripheral surface 60a. The diameter of the stator inner peripheral surface 60a is the same as the diameter of the outer peripheral surface of the can 20. The mold 63 has a terminal support portion 64.

[0040] The terminal support portion 64 extends laterally (in a direction perpendicular to the axis L) from the A-phase stator 61 and the B-phase stator 62. The terminal support portion 64 supports a plurality of terminals 65. The plurality of terminals 65 protrude laterally from the tip of the terminal support portion 64. The plurality of terminals 65 are connected to the coil 61c of the A-phase stator 61 and the coil 62c of the B-phase stator 62.

[0041] The can 20 is disposed inside the stator 60. The stator 60 constitutes a stepping motor 66 together with a magnet rotor 31 disposed inside the can 20.

[0042] The stepping motor 66 is capable of full-step and micro-step operation. Full-step operation refers to the operation of rotating the magnet rotor 31 in response to a single pulse input from a position where the magnetic poles (north and south poles) face the pole teeth 61a and 61b of the A-phase stator 61 (the position shown in FIG. 6A) to a position where the magnetic poles face the pole teeth 62a and 62b of the B-phase stator 62 adjacent to the pole teeth 61a and 61b (the position shown in FIG. 6B), or from the position shown in FIG. 6B to the position shown in FIG. 6A. In FIGS. 6A and 6B, the reference magnetic poles and pole teeth are indicated by black circles. In this embodiment, the rotation angle (step angle) per pulse during full-step operation is 7.5 degrees. Micro-step operation refers to the operation of rotating the magnet rotor 31 in response to a single pulse input by a step angle obtained by equally dividing the step angle of full-step operation. The microstep operation is performed by finely controlling the current value of the coil 61c of the A-phase stator 61 and the current value of the coil 62c of the B-phase stator 62. The step angle during the microstep operation is, for example, 0.9375 degrees (8 divisions), 1.875 degrees (4 divisions), or 1.5 degrees (5 divisions).

[0043] In this embodiment, when the stepping motor 66 performs a full step operation of 500 pulses (3750 degrees of rotation of the magnet rotor 31) while the valve element 40 is in the closed valve position P1, the valve element 40 moves to the fully open position P2.

[0044] The housing 70 is made of synthetic resin. The housing 70 is injection molded. The housing 70 accommodates the stator 60. The housing 70 has a peripheral wall portion 71 and an upper wall portion 72.

[0045] The peripheral wall portion 71 has a cylindrical shape. The stator 60 is embedded in the vertical center of the peripheral wall portion 71. The diameter of the inner peripheral surface 71a of the peripheral wall portion 71 is the same as the diameter of the stator inner peripheral surface 60a. The inner peripheral surface 71a is seamlessly connected to the stator inner peripheral surface 60a. The upper wall portion 72 has a dome shape. The upper wall portion 72 is connected to the upper end of the peripheral wall portion 71. The inner peripheral surface 71a of the peripheral wall portion 71, the inner surface 72a of the upper wall portion 72, and the stator inner peripheral surface 60a form an inner space 74 of the stator unit 50. A can 20 is disposed in the inner space 74. A support member 12 is disposed inside a lower portion 73 of the peripheral wall portion 71. A ring-shaped sealing member 19 is disposed between the lower portion 73 of the peripheral wall portion 71 and the support member 12. The sealing member 19 is made of an elastic material such as rubber. The sealing member 19 prevents moisture from entering the inner space 74 .

[0046] The housing 70 has a sub-board accommodating space 75. The sub-board accommodating space 75 extends in the horizontal direction. The sub-board accommodating space 75 is adjacent to the inner space 74. A partition wall 76 is disposed between the inner space 74 and the sub-board accommodating space 75. The partition wall 76 separates the inner space 74 from the sub-board accommodating space 75.

[0047] The case 80 is made of synthetic resin. The case 80 is injection molded. The case 80 has a case body 81, a lid 82, and a connector 83. The case body 81 has a rectangular box shape with one side (the right side in Figures 1 and 2) open. The lid 82 has a flat plate shape. The lid 82 covers the opening on the side of the case body 81. The connector 83 has an elliptical cylindrical shape. The connector 83 extends laterally from the top of the case body 81. The case body 81 and the connector 83 are integrally formed.

[0048] The case main body 81 has a side wall portion 84. The side wall portion 84 has a flat plate shape. The side wall portion 84 faces the lid body 82 with a gap therebetween in the horizontal direction. A rectangular case opening 84a is formed in the side wall portion 84. The case opening 84a is connected to the sub-board accommodating space 75 of the housing 70. The peripheral edge of the case opening 84a in the side wall portion 84 is joined to the housing 70.

[0049] The main board 90 is a printed circuit board on which electronic components are mounted. The main board 90 is arranged vertically inside the case 80. A board connector 91 is arranged on the surface of the main board 90 facing the side wall portion 84. A microcomputer 120 is mounted on the main board 90. A plurality of terminals 65 of the stator 60 are connected to the main board 90.

[0050] The sub-board 100 is a printed circuit board on which electronic components are mounted. The sub-board 100 is arranged horizontally in the sub-board accommodating space 75 of the housing 70. The sub-board 100 is arranged perpendicular to the main board 90. One end 100a of the sub-board 100 is arranged near the main board 90. The other end 100b of the sub-board 100 is arranged near the partition wall 76 of the housing 70.

[0051] A board terminal 101 is arranged on one end 100a of the sub-board 100. The board terminal 101 is connected to a board connector 91 of the main board 90. The sub-board 100 is connected to the main board 90 via the board terminal 101 and the board connector 91.

[0052] The magnetic sensor 110 is a rotation angle sensor. The magnetic sensor 110 is disposed at the other end 100b of the sub-substrate 100. The magnetic sensor 110 faces the permanent magnet 38 in the horizontal direction via the can 20 and the partition wall 76. The magnetic sensor 110 outputs a signal corresponding to the direction of the magnetic field generated by the permanent magnet 38 (i.e., the rotation angle of the magnet rotor 31 that rotates together with the permanent magnet 38).

[0053] The microcomputer 120 is, for example, a microcomputer for embedded devices that integrates a central processing unit, non-volatile memory, working memory, a communication module, a motor driver, and the like into a single package. The microcomputer 120 functions as a control device 200 that controls the motor-operated valve 1. The non-volatile memory, working memory, communication module, and motor driver may be individual electronic components that are externally connected to the microcomputer 120.

[0054] As shown in FIG. 7, the control device 200 has a storage unit 210, a communication unit 220, a calculation unit 230, and a rotation control unit 240. A non-volatile memory constitutes the storage unit 210. A central processing unit executes programs stored in the non-volatile memory and functions as the communication unit 220, the calculation unit 230, and the rotation control unit 240. The working memory temporarily stores variables such as the current position Pc of the valve element 40. The communication module is connected to the air conditioner control unit 400 via a cable (not shown) connected to the connector 83. The motor driver is connected to the stepping motor 66 (the coil 61c of the A-phase stator 61 and the coil 62c of the B-phase stator 62).

[0055] The storage unit 210 stores, for example, a table 310 shown in Fig. 8. The table 310 has a section information area 311, a pulse number information area 312, and a step angle information area 313.

[0056] Information about the sections set between the closed position P1 and the fully open position P2 of the valve element 40 is set in the section information area 311. The section information area 311 sets "First Section," "Second Section," and "Third Section" as information about the sections.

[0057] Information (pulse number information) relating to pulse numbers assigned in ascending order from the closed valve position P1 to the fully open position P2 of the valve element 40 is set in the pulse number information area 312. Pulse numbers "1" to "1500" are set as the pulse number information in the pulse number information area 312. Furthermore, pulse numbers "1" to "800" are assigned to the "first section" of the section information area 311, pulse numbers "801" to "1200" are assigned to the "second section," and pulse numbers "1201" to "1500" are assigned to the "third section."

[0058] FIG. 9 shows the relationship between the position of the valve disc 40 and the pulse number. Positions "0" to "1500" of the valve disc 40 are set in ascending order from the closed position P1 to the fully open position P2. Pulse numbers "1" to "1500" are assigned to the intervals between positions "0" and "1500." Pulse number "1" is assigned to the interval between positions "0" and "1," pulse number "2" is assigned to the interval between positions "1" and "2," and so on. For example, when the valve disc 40 is at position "1," information related to pulse number "1" is used to move the valve disc 40 to position "0," and information related to pulse number "2" is used to move the valve disc 40 to position "2."

[0059] In the step angle information area 313, information (step angle information) relating to the step angle corresponding to each pulse number set in the pulse number information area 312 is set. In the step angle information area 313, the number of divisions of the step angle in full-step operation is set as the step angle information. In the step angle information area 313, "8" is set corresponding to pulse numbers "1" to "800", "4" is set corresponding to pulse numbers "801" to "1200", and "1" is set corresponding to pulse numbers "1201" to "1500". In other words, the step angle (first angle) for the "first section" is set to 7.5 degrees / 8 = 0.9375 degrees, the step angle (second angle) for the "second section" is set to 7.5 degrees / 4 = 1.875 degrees, and the step angle (third angle) for the "third section" is set to 7.5 degrees / 1 = 7.5 degrees. The stepping motor 66 has step angles that are different from one another in the first, second, and third sections. Note that a numerical value indicating the step angle may be set as the step angle information.

[0060] The storage unit 210 stores the pulse number information and step angle information in a table format, but may store them in other formats such as mathematical formulas.

[0061] The motor-operated valve 1 operates as a motor-operated valve having the flow rate characteristics shown in FIG. 10 by rotating the stepping motor 66 (magnet rotor 31) based on the table 310.

[0062] The communication unit 220 communicates with the control unit 400 via a communication module. The communication unit 220 receives various commands from the control unit 400 and transfers them to the calculation unit 230. The communication unit 220 acquires various states of the motor-operated valve 1 from the calculation unit 230 and the rotation control unit 240 and transmits them to the control unit 400. The communication unit 220 receives a valve element movement command from the control unit 400. The valve element movement command includes information regarding a movement target position Pt of the valve element 40. The movement target position Pt is specified as a valve opening degree. Note that the movement target position Pt may also be specified as a relative movement distance (such as the number of pulses) from the current position Pc of the valve element 40. The current position Pc of the valve element is stored in a working memory.

[0063] In the motor-operated valve 1, the valve opening degrees 0[%] to 100[%] specified by the control unit 400 correspond to positions "0" to "1500" of the valve disc 40. When the number indicating the current position Pc of the valve disc 40 is smaller than the number indicating the target movement position Pt, the rotation direction of the stepping motor 66 is the direction in which the valve disc 40 moves away from the valve seat 18 (valve opening direction). When the number indicating the current position Pc of the valve disc 40 is larger than the number indicating the target movement position Pt, the rotation direction of the stepping motor 66 is the direction in which the valve disc 40 moves closer to the valve seat 18 (valve closing direction).

[0064] The calculation unit 230 performs various calculations. When the communication unit 220 receives a valve element movement command, the calculation unit 230 acquires the position of the valve element 40 corresponding to the valve opening specified by the movement target position Pt in the valve element movement command. For example, when the valve opening is 10[%], the calculation unit 230 acquires the position "150" as the movement target position Pt, when the valve opening is 50[%], the calculation unit 230 acquires the position "750" as the movement target position Pt, and when the valve opening is 90[%], the calculation unit 230 acquires the position "1350" as the movement target position Pt.

[0065] Then, the calculation unit 230 acquires pulse numbers between the current position Pc (start point) and the movement target position Pt (end point) of the valve disc 40. For example, when the current position Pc is position "0" and the movement target position Pt is position "150", the calculation unit 230 acquires pulse numbers "1" to "150". When the current position Pc is position "150" and the movement target position Pt is position "750", the calculation unit 230 acquires pulse numbers "151" to "750". When the current position Pc is position "750" and the movement target position Pt is position "300", the calculation unit 230 acquires pulse numbers "750" to "301".

[0066] Furthermore, the calculation unit 230 acquires the rotation angle of the magnet rotor 31 based on the signal output by the magnetic sensor 110 .

[0067] The rotation control unit 240 acquires step angle information corresponding to each pulse number one by one from the table 310 in the order of the pulse numbers assigned from the current position Pc to the movement target position Pt of the valve disc 40. Then, the rotation control unit 240 calculates the step angle using the step angle information, and inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepping motor 66.

[0068] In the rotation control unit 240, the pulse rate when the valve 40 is in the first section is set to eight times the pulse rate when the valve 40 is in the third section. In the rotation control unit 240, the pulse rate when the valve 40 is in the second section is set to four times the pulse rate when the valve 40 is in the third section. The pulse rate is expressed in terms of the number of pulses input per second (PPS). In this embodiment, the pulse rate when the valve 40 is in the first section is 1000 [PPS], the pulse rate when the valve 40 is in the second section is 500 [PPS], and the pulse rate when the valve 40 is in the third section is 125 [PPS].

[0069] The rotation control unit 240 also determines whether the valve element movement command is successful. Specifically, the rotation control unit 240 compares the rotation angle of the magnet rotor 31, calculated by integrating the step angles corresponding to each pulse number assigned from the current position Pc to the movement target position Pt, with the rotation angle of the magnet rotor 31 acquired by the calculation unit 230 based on the signal from the magnetic sensor 110. If these rotation angles match, the rotation control unit 240 transmits information indicating that the valve element movement command was successful as the command execution result to the control unit 400 via the communication unit 220. If these rotation angles do not match, the rotation control unit 240 transmits information indicating that the valve element movement command was unsuccessful as the command execution result to the control unit 400 via the communication unit 220.

[0070] In the electric valve 1, the support member 12, valve port 17, can 20, magnet rotor 31, valve shaft holder 32, guide bush 33, valve shaft 34, valve body 40 (tapered surface 41), and stator 60 (A-phase stator 61, B-phase stator 62) each have a central axis that coincides with the axis L.

[0071] Next, an example of the operation of the motor-operated valve 1 will be described.

[0072] The control device 200 of the motor-operated valve 1 enters a startup state when power is applied. In the startup state, the control device 200 performs initialization processing. After moving the valve element 40 to the closed valve position P1, the control device 200 transitions to a normal operating state. At this time, the current position Pc of the valve element 40 is the closed valve position P1 (position "0" of the valve element 40). In the normal operating state, the control device 200 waits for a command from the control unit 400. The control unit 400 recognizes that the motor-operated valve 1 has the flow rate characteristics shown in FIG. 10.

[0073] For example, when the control device 200 receives a valve element movement command including a movement target position Pt specifying a valve opening of 90[%] from the control unit 400, the control device 200 acquires the position "1350" as the movement target position Pt. Then, the control device 200 acquires pulse numbers "1" to "1350" assigned from the current position Pc to the movement target position Pt.

[0074] The control device 200 calculates the step angle corresponding to the pulse number "1" to "1350" based on the table 310. Because the number indicating the current position Pc (position "0") is smaller than the number indicating the movement target position Pt (position "1350"), the control device 200 sets the rotation direction to the "valve opening direction." The control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepping motor 66 (magnet rotor 31). The valve stem holder 32 rotates together with the magnet rotor 31. The valve stem holder 32 moves upward due to the screw feed action between the female thread 32c of the valve stem holder 32 and the male thread 33c of the guide bush 33. The valve stem 34 moves upward together with the valve stem holder 32, and the valve disc 40 moves away from the valve seat 18.

[0075] The control device 200 inputs pulses at 1000 [PPS] in the first section (pulse numbers "1" to "800"), inputs pulses at 500 [PPS] in the second section (pulse numbers "801" to "1200"), and inputs pulses at 125 [PPS] in the third section (pulse numbers "1201" to "1350"). The control device 200 also integrates the step angles corresponding to the pulse numbers from "1" to "1350".

[0076] When the stepping motor 66 finishes rotating at the step angles corresponding to pulse numbers "1" to "1350," the control device 200 stores the position "1350" in its working memory as the current position Pc. The control device 200 also determines whether the valve element movement command is successful. Specifically, the control device 200 compares the rotation angle of the magnet rotor 31 obtained by integrating the step angles with the rotation angle of the magnet rotor 31 obtained based on the signal from the magnetic sensor 110. If these rotation angles match, the control device 200 transmits information indicating that the valve element movement command was successful to the control unit 400 as the command execution result. If these rotation angles do not match, the control device 200 transmits information indicating that the valve element movement command was unsuccessful to the control unit 400 as the command execution result. The control device 200 then waits for the next command from the control unit 400.

[0077] Next, when the control device 200 receives a valve element movement command including a movement target position Pt specifying a valve opening of 50[%] from the control unit 400, the control device 200 acquires the position "750" as the movement target position Pt. Then, the control device 200 acquires pulse numbers "1350" to "751" assigned from the current position Pc to the movement target position Pt.

[0078] The control device 200 calculates the step angles corresponding to the pulse numbers "1350" to "751" based on the table 310. Because the number indicating the current position Pc (position "1350") is greater than the number indicating the movement target position Pt (position "750"), the control device 200 determines the rotation direction to be the "valve closing direction." The control device 200 inputs the pulses, step angle, and rotation direction to the motor driver to rotate the stepping motor 66 (magnet rotor 31). The valve stem holder 32 rotates together with the magnet rotor 31. The valve stem holder 32 moves downward due to the screw feed action between the female thread 32c of the valve stem holder 32 and the male thread 33c of the guide bush 33. The valve stem 34 moves downward together with the valve stem holder 32, and the valve disc 40 approaches the valve seat 18.

[0079] The control device 200 inputs pulses at 125 [PPS] in the third section (pulse numbers "1350" to "1201"), inputs pulses at 500 [PPS] in the second section (pulse numbers "1200" to "801"), and inputs pulses at 1000 [PPS] in the first section (pulse numbers "800" to "751"). The control device 200 also integrates the step angles corresponding to the pulse numbers from "1350" to "751".

[0080] When the control device 200 finishes rotating the stepping motor 66 at the step angles corresponding to pulse numbers "1350" to "751," it stores the position "751" in its working memory as the current position Pc. The control device 200 also determines whether the valve element movement command is successful or not, and transmits the execution result of the valve element movement command to the control unit 400. The control device 200 then waits for the next command from the control unit 400. Thereafter, the control device 200 performs an operation according to the received command.

[0081] The motor-operated valve 1 according to this embodiment includes a valve body 10 having a valve port 17, a valve element 40 disposed opposite the valve port 17, a drive mechanism 30 for vertically moving the valve element 40, and a control device 200 for controlling the drive mechanism 30. The drive mechanism 30 includes a stepping motor 66, which moves the valve element 40 by rotating the stepping motor 66. The control device 200 includes a memory unit 210, a communication unit 220, a calculation unit 230, and a rotation control unit 240. The memory unit 210 stores pulse number information related to pulse numbers assigned to the valve element 40 in ascending order from a closed position P1 to a fully open position P2, and step angle information related to the step angles corresponding to each pulse number. The communication unit 220 receives a valve element movement command related to a target position Pt of the valve element 40 from the control unit 400. The calculation unit 230 acquires pulse numbers assigned to the valve element 40 from its current position Pc to its target position Pt. The rotation control unit 240 rotates the stepping motor 66 in the order of the pulse numbers assigned from the current position Pc of the valve element 40 to the movement target position Pt by a step angle corresponding to each pulse number.

[0082] As a result, the motor-operated valve 1 can set the step angle individually for each pulse allocated to the valve element 40 from the closed position P1 to the fully open position P2, and can adjust the movement amount of the valve element 40 per pulse (i.e., the amount of change in the flow rate of the refrigerant flowing through the valve port 17). Therefore, the motor-operated valve 1 can obtain desired flow rate characteristics regardless of the shape of the valve element.

[0083] Furthermore, in the motor-operated valve 1, a first section, a second section, and a third section are set between the closed position P1 and the fully open position P2 of the valve element 40. A first angle (0.9375 degrees) is set as the step angle corresponding to the pulse number assigned to the first section. A second angle (1.875 degrees) is set as the step angle corresponding to the pulse number assigned to the second section. A third angle (7.5 degrees) is set as the step angle corresponding to the pulse number assigned to the third section. The first angle, the second angle, and the third angle are different from one another. In this way, the motor-operated valve 1 can obtain flow characteristics having three sections with different amounts of change in flow rate per pulse. The motor-operated valve 1 can precisely control the flow rate within a relatively small range of valve opening.

[0084] Furthermore, the first angle is the step angle in microstep operation, which is 1 / n (n=8) of the full-step operation of the stepping motor 66. The second angle is the step angle in microstep operation, which is 1 / m (m=4) of the full-step operation of the stepping motor 66. And the third angle is the step angle in full-step operation of the stepping motor 66. In this way, the motor-operated valve 1 can obtain, with a relatively simple configuration, flow characteristics having three sections with different amounts of change in flow rate per pulse.

[0085] The valve element 40 also has a tapered surface 41 whose diameter decreases toward the valve port 17. When the valve element 40 is in the first, second, or third section, the flow rate is determined by the gap between the tapered surface 41 and the inner circumferential surface of the valve port 17. In this way, the motor-operated valve 1 can obtain flow characteristics having three sections with different amounts of change in flow rate per pulse, using a valve element 40 with a relatively simple shape.

[0086] Furthermore, the pulse speed when the valve element 40 is in the first section (first section pulse speed) is eight times the pulse speed when the valve element 40 is in the third section (third section pulse speed). The pulse speed when the valve element 40 is in the second section (second section pulse speed) is four times the third section pulse speed. By doing so, the motor-operated valve 1 can make the movement speed of the valve element 40 the same in the first section, second section, and third section. This allows the valve element 40 to move from the closed position P1 to the fully open position P2 more quickly than when the pulse speeds are the same in the first section, second section, and third section.

[0087] In addition, when the first section is included in the distance from the current position Pc to the movement target position Pt, the motor-operated valve 1 may set the first-section pulse speed to eight times the third-section pulse speed when the number of pulses related to the movement of the valve disc 40 in the first section exceeds a predetermined reference pulse number (e.g., 100), and may set the first-section pulse speed to the same as the third-section pulse speed when the number of pulses is equal to or less than the reference pulse number. Similarly, when the second section is included in the distance from the current position Pc to the movement target position Pt, the motor-operated valve 1 may set the second-section pulse speed to four times the third-section pulse speed when the number of pulses related to the movement of the valve disc 40 in the second section exceeds the reference pulse number, and may set the second-section pulse speed to the same as the third-section pulse speed when the number of pulses is equal to or less than the reference pulse number. In this way, when the movement amount of the valve disc 40 is large in the first section or the second section, the valve disc 40 is moved at high speed, thereby shortening the time required to switch the flow rate. Furthermore, when the movement amount of the valve element 40 is small in the first section or the second section, the valve element 40 is moved at a low speed, so that the flow rate can be switched gradually.

[0088] The electric valve 1 has a flow characteristic with three sections with different amounts of change in flow rate per pulse, but by appropriately setting the table 310, it may have other flow characteristics, such as an equal percentage characteristic.

[0089] (Variation) Next, motor-operated valves 1A and 1B, which are modifications of the motor-operated valve 1 described above, will be described with reference to FIGS.

[0090] FIG. 11 is a diagram showing a modified example of the table of FIG. 8. FIG. 12 is a diagram explaining the relationship between pulse numbers assigned from the closed position to the fully open position and the position of the valve disc, as shown in the table of FIG. 11. FIG. 13 is a graph showing the relationship between the position of the valve disc and the flow rate when the stepping motor of the motor-operated valve of FIG. 1 rotates based on the table of FIG. 11. FIG. 14 is a diagram showing another modified example of the table of FIG. 8. FIG. 15 is a diagram explaining the relationship between pulse numbers assigned from the closed position to the fully open position and the position of the valve disc, as shown in the table of FIG. 14. FIG. 16 is a graph showing the relationship between the position of the valve disc and the flow rate (flow rate characteristics) when the stepping motor of the motor-operated valve of FIG. 1 rotates based on the table of FIG. 14. In FIG. 16, the dashed-dotted line graph shows the flow rate characteristics in the activated state, and the solid line graph shows the flow rate characteristics in the normal operating state. At positions "650" to "1900" in FIG. 16, the dashed-dotted line and the solid line are drawn shifted up and down, but in reality they are aligned with each other.

[0091] The motor-operated valve 1 described above rotates the stepping motor 66 based on a table 310 shown in FIG. 8 stored in the memory unit 210 of the control device 200. The motor-operated valve 1 has a table 320 shown in FIG. 11 instead of table 310, thereby becoming a motor-operated valve 1A with different flow characteristics. The hardware configuration of the motor-operated valve 1A is the same as that of the motor-operated valve 1.

[0092] In the motor-operated valve 1A, the storage unit 210 stores a table 320 shown in Fig. 11. The table 320 has a section information area 321, a pulse number information area 322, and a step angle information area 323.

[0093] Information about the section set between the valve closed position P1 and the fully open position P2 of the valve element 40 is set in the section information area 321. In the section information area 321, "Second Section" and "First Section" are set as information about the sections.

[0094] Information (pulse number information) relating to pulse numbers assigned in ascending order from the closed valve position P1 to the fully open position P2 of the valve element 40 is set in the pulse number information area 322. Pulse numbers "1" to "1500" are set as the pulse number information in the pulse number information area 322. Furthermore, pulse numbers "1" to "250" are assigned to the "second section" of the section information area 321, and pulse numbers "251" to "1500" are assigned to the "first section."

[0095] 12 shows the relationship between the position of the valve element 40 and the pulse number. Positions "0" to "1500" of the valve element 40 are set in ascending order from the valve closed position P1 to the fully open position P2. Pulse numbers "1" to "1500" are assigned to the intervals between the positions "0" to "1500."

[0096] In the step angle information area 323, information (step angle information) relating to the step angle corresponding to each pulse number set in the pulse number information area 322 is set. In the step angle information area 323, the number of divisions of the step angle in full-step operation is set as the step angle information. In the step angle information area 323, "1" is set corresponding to pulse numbers "1" to "250", and "5" is set corresponding to pulse numbers "251" to "1500". In other words, the step angle (second angle) for the "second section" is set to 7.5 degrees / 1 = 7.5 degrees, and the step angle (first angle) for the "first section" is set to 7.5 degrees / 5 = 1.5 degrees. The stepping motor 66 has different step angles in the second section and the first section.

[0097] The motor-operated valve 1A operates as a motor-operated valve having the flow rate characteristics shown in FIG. 13 by rotating the stepping motor 66 (magnet rotor 31) based on the table 320.

[0098] In the motor-operated valve 1A, the valve opening degrees 0[%] to 100[%] specified by the control unit 400 correspond to positions "0" to "1500" of the valve element 40.

[0099] In the rotation control unit 240, the pulse speed when the valve element 40 is in the first section is set to five times the pulse speed when the valve element 40 is in the second section. In the motor-operated valve 1A, the pulse speed when the valve element 40 is in the first section is 625 [PPS], and the pulse speed when the valve element 40 is in the second section is 125 [PPS].

[0100] Next, an example of the operation of the motor-operated valve 1A will be described.

[0101] The control device 200 of the motor-operated valve 1A enters a start-up state when power is applied. In the start-up state, the control device 200 performs initialization processing. After moving the valve element 40 to the valve closed position P1, the control device 200 transitions to a normal operating state. At this time, the current position Pc of the valve element 40 is the valve closed position P1 (position "0" of the valve element 40). In the normal operating state, the control device 200 waits for a command from the control unit 400. The control unit 400 recognizes that the motor-operated valve 1A has the flow rate characteristics shown in FIG. 13.

[0102] For example, when the control device 200 receives a valve element movement command including a movement target position Pt specifying a valve opening of 90[%] from the control unit 400, the control device 200 acquires the position "1350" as the movement target position Pt. Then, the control device 200 acquires pulse numbers "1" to "1350" assigned from the current position Pc to the movement target position Pt.

[0103] The control device 200 calculates the step angle corresponding to the pulse number "1" to "1350" based on the table 320. Because the number indicating the current position Pc (position "0") is smaller than the number indicating the movement target position Pt (position "1350"), the control device 200 determines the rotation direction to be the "valve opening direction." The control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepping motor 66. As a result, the valve disc 40 moves away from the valve seat 18.

[0104] The control device 200 inputs pulses at 125 [PPS] in the second section (pulse numbers "1" to "250") and inputs pulses at 625 [PPS] in the first section (pulse numbers "251" to "1350") The control device 200 also integrates the step angles corresponding to the pulse numbers from "1" to "1350".

[0105] When the control device 200 finishes rotating the stepping motor 66 at the step angles corresponding to pulse numbers "1" to "1350," it stores the position "1350" in its working memory as the current position Pc. The control device 200 also determines whether the valve element movement command has been successful, and transmits the command execution result of the valve element movement command to the control unit 400. The control device 200 then waits for the next command from the control unit 400.

[0106] Next, when the control device 200 receives a valve element movement command including a movement target position Pt specifying a valve opening of 10% from the control unit 400, the control device 200 acquires the position "150" as the movement target position Pt. Then, the control device 200 acquires pulse numbers "1350" to "151" assigned from the current position Pc to the movement target position Pt.

[0107] The control device 200 calculates the step angles corresponding to the pulse numbers "1350" to "151" based on the table 320. Because the number indicating the current position Pc (position "1350") is greater than the number indicating the movement target position Pt (position "150"), the control device 200 determines the rotation direction to be the "valve closing direction." The control device 200 inputs the pulses, step angle, and rotation direction to the motor driver to rotate the stepping motor 66 (magnet rotor 31). This causes the valve disc 40 to approach the valve seat 18.

[0108] The control device 200 inputs pulses at 625 [PPS] in the first section (pulse numbers "1350" to "251") and inputs pulses at 125 [PPS] in the second section (pulse numbers "250" to "151") The control device 200 also integrates the step angles corresponding to the pulse numbers from "1350" to "151".

[0109] When the stepping motor 66 has finished rotating at the step angles corresponding to pulse numbers "1350" to "151," the control device 200 stores the position "150" in the working memory as the current position Pc. The control device 200 also determines whether the valve element movement command has been successful, and transmits the execution result of the valve element movement command to the control unit 400. The control device 200 then waits for the next command from the control unit 400. Thereafter, the control device 200 performs an operation according to the received command.

[0110] The motor-operated valve 1A has the same functions and effects as the motor-operated valve 1 described above.

[0111] Furthermore, in the motor-operated valve 1A, a first section and a second section are set between the closed position P1 and the fully open position P2 of the valve element 40. A first angle (1.5 degrees) is set as the step angle corresponding to the pulse number assigned to the first section. A second angle (7.5 degrees) is set as the step angle corresponding to the pulse number assigned to the second section. The first angle and the second angle are different. In this way, the motor-operated valve 1A can obtain flow characteristics having two sections with different amounts of change in flow rate per pulse. The motor-operated valve 1A can precisely control the flow rate within a relatively large range of valve opening.

[0112] Furthermore, the first angle is the step angle in microstep operation, which is 1 / n (n=5) of the full-step operation of the stepping motor 66. The second angle is the step angle in full-step operation of the stepping motor 66. In this way, the motor-operated valve 1A can obtain, with a relatively simple configuration, flow characteristics having two sections with different amounts of change in flow rate per pulse.

[0113] The valve element 40 also has a tapered surface 41 whose diameter decreases toward the valve port 17. When the valve element 40 is in the first section or the second section, the flow rate is determined by the gap between the tapered surface 41 and the inner circumferential surface of the valve port 17. In this way, the motor-operated valve 1A can obtain flow characteristics having two sections with different amounts of change in flow rate per pulse, using a valve element 40 with a relatively simple shape.

[0114] Furthermore, the pulse speed when the valve element 40 is in the first section is five times the pulse speed when the valve element 40 is in the second section. By doing so, the motor-operated valve 1A can make the movement speed of the valve element 40 the same in the first section and the second section. This allows the valve element 40 to move from the closed position P1 to the fully open position P2 more quickly than when the pulse speed is the same in the first section and the second section.

[0115] The motor-operated valve 1 becomes a motor-operated valve 1B with different flow characteristics by having tables 330 and 340 shown in Fig. 14 instead of the table 310 shown in Fig. 8. The hardware configuration of the motor-operated valve 1B is the same as that of the motor-operated valve 1.

[0116] In the motor-operated valve 1B, the memory unit 210 stores tables 330 and 340 shown in Fig. 14. Table 330 is used in the startup state immediately after startup of the motor-operated valve 1B. Table 340 is used in the normal operating state after the startup state of the motor-operated valve 1B.

[0117] The table 330 has a section information area 331 , a pulse number information area 332 , and a step angle information area 333 .

[0118] Information about the section set between the valve closed position P1 and the fully open position P2 of the valve element 40 is set in the section information area 331. In the section information area 331, "Second Section" and "First Section" are set as information about the sections.

[0119] Information (pulse number information) relating to pulse numbers assigned in ascending order from the closed valve position P1 to the fully open position P2 of the valve element 40 is set in the pulse number information area 332. Pulse numbers "401" to "1900" are set as the pulse number information in the pulse number information area 332. Furthermore, pulse numbers "401" to "650" are assigned to the "second section" of the section information area 331, and pulse numbers "651" to "1900" are assigned to the "first section."

[0120] In step angle information area 333, information (step angle information) relating to the step angle corresponding to each pulse number set in pulse number information area 332 is set. In step angle information area 333, the number of divisions of the step angle in full-step operation is set as the step angle information. In step angle information area 333, "1" is set corresponding to pulse numbers "401" to "650", and "5" is set corresponding to pulse numbers "651" to "1900". In other words, 7.5 degrees / 1 = 7.5 degrees is set as the step angle (second angle) of the "second section", and 7.5 degrees / 5 = 1.5 degrees is set as the step angle (first angle) of the "first section".

[0121] The table 340 has a section information area 341 , a pulse number information area 342 , and a step angle information area 343 .

[0122] Information about the section set between the valve closed position P1 and the fully open position P2 of the valve element 40 is set in the section information area 341. "Second section" and "first section" are set as information about the sections in the section information area 341.

[0123] Information (pulse number information) relating to pulse numbers assigned in ascending order from the closed valve position P1 to the fully open position P2 of the valve element 40 is set in the pulse number information area 342. Pulse numbers "1" to "1900" are set as the pulse number information in the pulse number information area 342. Furthermore, pulse numbers "1" to "150" are assigned to the "second section" of the section information area 341, and pulse numbers "151" to "1900" are assigned to the "first section."

[0124] In step angle information area 343, information (step angle information) relating to the step angle corresponding to each pulse number set in pulse number information area 342 is set. In step angle information area 343, the number of divisions of the step angle in full-step operation is set as the step angle information. In step angle information area 343, "1" is set corresponding to pulse numbers "1" to "150", and "5" is set corresponding to pulse numbers "151" to "1900". In other words, 7.5 degrees / 1 = 7.5 degrees is set as the step angle (second angle) of the "second section", and 7.5 degrees / 5 = 1.5 degrees is set as the step angle (first angle) of the "first section".

[0125] FIG. 15 shows the relationship between the position of the valve disc 40 and the pulse number. In FIG. 15, the closed position P1, fully open position P2, first section, and second section in the startup state are indicated by dashed lines, and the closed position P1, fully open position P2, first section, and second section in the normal operating state are indicated by solid lines. Corresponding to table 330 used in the startup state, positions "400" to "1900" of the valve disc 40 are set in ascending order from the closed position P1 to the fully open position P2. Pulse numbers "401" to "1900" are assigned to the intervals between positions "400" to "1900." Corresponding to table 340 used in the normal operating state, positions "0" to "1900" of the valve disc 40 are set in ascending order from the closed position P1 to the fully open position P2. Pulse numbers "1" to "1900" are assigned to the intervals between positions "0" to "1900."

[0126] The pulse number information set in the pulse number information area 332 of the table 330 and the step angle information set in the step angle information area 333 are startup state pulse number information and startup state step angle information. The pulse number information set in the pulse number information area 342 of the table 340 and the step angle information set in the step angle information area 343 are normal operation state pulse number information and normal operation state step angle information. Pulse numbers "401" to "1900" are set in the startup state pulse number information, and pulse numbers "1" to "1900" are set in the normal operation state pulse number information. Therefore, the startup state pulse number information and the normal operation state pulse number information are different from each other. Furthermore, "1" is assigned as the startup state step angle information to pulse numbers "401" to "650" in the startup state pulse number information, and "5" is assigned as the startup state step angle information to pulse numbers "651" to "1900" in the startup state pulse number information. Furthermore, "1" is assigned as the normal operation state step angle information to pulse numbers "1" to "150" of the normal operation state pulse number information, and "5" is assigned as the normal operation state step angle information to pulse numbers "151" to "1900" of the normal operation state pulse number information. Therefore, the startup state step angle information and the normal operation state step angle information are different from each other. Note that the startup state pulse number information and the normal operation state pulse number information may be the same, and the startup state step angle information and the normal operation state step angle information may be different from each other.

[0127] In the motor-operated valve 1B, the calculation unit 230 transitions from the startup state to the normal operation state when the communication unit 220 receives a normal operation start command from the control unit 400. In the startup state, the valve opening of 0[%] to 100[%] specified by the control unit 400 corresponds to positions of the valve disc 40 of "400" to "1900". In the normal operation state, the valve opening of 0[%] to 100[%] specified by the control unit 400 corresponds to positions of the valve disc 40 of "0" to "1900". Then, in the startup state and the normal operation state, when the communication unit 220 receives a valve disc movement command, the calculation unit 230 acquires the position of the valve disc 40 corresponding to the valve opening specified by the movement target position Pt of the valve disc movement command. In the activated state, for example, when the valve opening is 10% the calculation unit 230 acquires a position "550" as the movement target position Pt, when the valve opening is 50% the calculation unit 230 acquires a position "1150" as the movement target position Pt, and when the valve opening is 80% the calculation unit 230 acquires a position "1600" as the movement target position Pt. In the normal operating state, for example, when the valve opening is 10% the calculation unit 230 acquires a position "190" as the movement target position Pt, when the valve opening is 50% the calculation unit 230 acquires a position "950" as the movement target position Pt, and when the valve opening is 80% the calculation unit 230 acquires a position "1520" as the movement target position Pt.

[0128] Next, an example of the operation of the motor-operated valve 1B will be described.

[0129] The control device 200 of the motor-operated valve 1B rotates the stepping motor 66 using the table 330 in the activated state, and rotates the stepping motor 66 using the table 340 in the normal operating state.

[0130] The control device 200 of the motor-operated valve 1B enters a startup state when power is applied. In the startup state, the control device 200 performs initialization processing. The control device 200 moves the valve element 40 to the valve closed position P1. At this time, the current position Pc of the valve element 40 is the valve closed position P1 (position "400" of the valve element 40). In the startup state, the control device 200 waits for a command from the control unit 400. The control unit 400 recognizes that the motor-operated valve 1B has the flow characteristics shown by the dashed dotted line in Figure 16 in the startup state, and has the flow characteristics shown by the solid line in Figure 16 in the normal operating state.

[0131] For example, when the control device 200 receives a valve element movement command including a movement target position Pt specifying a valve opening of 80[%] from the control unit 400, the control device 200 acquires the position "1600" as the movement target position Pt. Then, the control device 200 acquires pulse numbers "401" to "1600" assigned from the current position Pc to the movement target position Pt.

[0132] The control device 200 calculates the step angles corresponding to the pulse numbers "401" to "1600" based on the table 330. Because the number indicating the current position Pc (position "400") is smaller than the number indicating the movement target position Pt (position "1600"), the control device 200 determines the rotation direction to be the "valve opening direction." The control device 200 inputs the pulses, step angle, and rotation direction to the motor driver to rotate the stepping motor 66. As a result, the valve disc 40 moves away from the valve seat 18.

[0133] The control device 200 inputs pulses at 125 [PPS] in the second section (pulse numbers "401" to "650") and inputs pulses at 625 [PPS] in the first section (pulse numbers "651" to "1600") The control device 200 also integrates the step angles corresponding to the pulse numbers from "401" to "1600".

[0134] When the stepping motor 66 has finished rotating at the step angles corresponding to pulse numbers "401" to "1600," the control device 200 stores the position "1600" in the working memory as the current position Pc. The control device 200 also determines whether the valve element movement command has been executed, and transmits the command execution result of the valve element movement command to the control unit 400. The control device 200 then waits for the next command from the control unit 400.

[0135] Next, when the control device 200 receives a normal operation start command from the control unit 400, it transitions from the startup state to the normal operation state. By transitioning to the normal operation state, the control device 200 uses the table 340 instead of the table 330.

[0136] Next, when the control device 200 receives a valve element movement command including a movement target position Pt specifying a valve opening of 50[%] from the control unit 400, the control device 200 acquires the position "950" as the movement target position Pt. Then, the control device 200 acquires pulse numbers "1600" to "951" assigned from the current position Pc to the movement target position Pt.

[0137] The control device 200 calculates the step angles corresponding to the pulse numbers "1600" to "951" based on the table 340. Because the number indicating the current position Pc (position "1600") is greater than the number indicating the movement target position Pt (position "950"), the control device 200 determines the rotation direction to be the "valve closing direction." The control device 200 inputs the pulses, step angle, and rotation direction to the motor driver to rotate the stepping motor 66. This causes the valve disc 40 to approach the valve seat 18.

[0138] The control device 200 inputs pulses at 625 [PPS] in the first section (pulse numbers "1600" to "951") and also integrates the step angles corresponding to the pulse numbers from "1600" to "951".

[0139] When the rotation of the stepping motor 66 at the step angles corresponding to pulse numbers "1600" to "951" is completed, the control device 200 stores the position "951" in the working memory as the current position Pc. The control device 200 also determines whether the valve element movement command is successful or not, and transmits the command execution result of the valve element movement command to the control unit 400. The control device 200 then waits for the next command from the control unit 400.

[0140] Next, when the control device 200 receives, for example, a valve element movement command including a movement target position Pt specifying a valve opening of 0 [%] from the control unit 400, the control device 200 acquires the position "0" as the movement target position Pt. Then, the control device 200 acquires the pulse numbers "950" to "1" assigned from the current position Pc to the movement target position Pt.

[0141] The control device 200 calculates the step angle corresponding to the pulse numbers "950" to "1" based on the table 340. Because the number indicating the current position Pc (position "950") is greater than the number indicating the movement target position Pt (position "0"), the control device 200 determines the rotation direction to be the "valve closing direction." The control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepping motor 66. This causes the valve element 40 to contact the valve seat 18.

[0142] The control device 200 inputs pulses at 625 [PPS] in the first section (pulse numbers "950" to "151") and inputs pulses at 125 [PPS] in the second section (pulse numbers "150" to "1"). The control device 200 also integrates the step angles corresponding to the pulse numbers from "950" to "1".

[0143] When the control device 200 has completed rotation of the stepping motor 66 at the step angles corresponding to pulse numbers "950" to "1," it stores the position "0" in its working memory as the current position Pc. The control device 200 also determines whether the valve element movement command has been successful, and transmits the execution result of the valve element movement command to the control unit 400. The control device 200 then waits for the next command from the control unit 400. Thereafter, the control device 200 performs an operation according to the received command.

[0144] The motor-operated valve 1B has the same functions and effects as the motor-operated valve 1 and the motor-operated valve 1A described above.

[0145] Furthermore, the storage unit 210 stores a table 330 and a table 340. When the control device is in the activated state, it uses the pulse number information and step angle information set in table 330 (activated state pulse number information and activated state step angle information), and when in the normal operating state, it uses the pulse number information and step angle information set in table 340 (normal operating state pulse number information and normal operating state step angle information). In this way, the motor-operated valve 1B can change its flow characteristics during operation, and can flexibly respond to the requirements of the system in which the motor-operated valve 1B is incorporated.

[0146] Furthermore, when the control device 200 receives a normal operation start command from the control unit 400 while in the activated state, it transitions to the normal operating state. In this way, the operating state of the control device 200 can be changed by the control unit 400. Therefore, compared to when the control device 200 autonomously changes the operating state, it is possible to prevent a mismatch between the operating state of the control device 200 that the control unit 400 knows and the actual operating state of the control device 200.

[0147] Note that the control device 200 may autonomously transition to the normal operating state when the valve element 40 moves to a predetermined activation completion position (for example, position "650" in FIG. 16) during activation.

[0148] The electric valve 1 was a direct-acting electric valve in which the rotation of the magnet rotor 31 was used in the drive mechanism 30 without being slowed down, but the present invention can also be applied to an electric valve having a drive mechanism with a speed reduction mechanism that slows down the rotation of the magnet rotor.

[0149] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the embodiments. Those skilled in the art may appropriately add, delete, or modify components of the above-described embodiments, or appropriately combine features of the embodiments, as long as they do not deviate from the spirit of the present invention. [Explanation of symbols]

[0150] 1, 1A, 1B... Motor-operated valve, 10... Valve body, 11... Body member, 11a... Mounting hole, 12... Support member, 12a... Fitting hole, 13... Connection member, 14... Valve chamber, 15... Flow path, 16... Flow path, 17... Valve port, 18... Valve seat, 19... Sealing member, 20... Can, 30... Drive mechanism, 31... Magnet rotor, 32... Valve stem holder, 32c... Female thread, 33... Guide bush, 33a... Base, 33b... Valve stem support portion, 33c... Male thread, 34... Valve stem, 34a... Large diameter portion, 34b... Small diameter portion, 34c... Step portion, 35... Support ring, 36... Push Nut, 37...valve-closing spring, 38...permanent magnet, 39...fixing device, 40...valve body, 40a...tip, 41...tapered surface, 50...stator unit, 60...stator, 60a...stator inner surface, 61...A-phase stator, 61a...pole teeth, 61b...pole teeth, 61c...coil, 62...B-phase stator, 62a...pole teeth, 62b...pole teeth, 62c...coil, 63...mold, 64...terminal support portion, 65...terminal, 66...stepping motor, 70...housing, 71...circumferential wall portion, 71a...inner surface, 72...upper wall portion, 72a...inner surface , 73...lower part, 74...inner space, 75...sub-board accommodating space, 76...partition wall, 80...case, 81...case body, 82...lid body, 83...connector, 84...side wall portion, 84a...case opening, 90...main board, 91...board connector, 100...sub-board, 100a...end, 100b...end, 101...board terminal, 110...magnetic sensor, 120...microcomputer, 200...control device, 210...memory unit, 220...communication unit, 230...calculation unit, 240...rotation control unit, 310...table, 311...section information area, 3 12...pulse number information area, 313...step angle information area, 320...table, 321...section information area, 322...pulse number information area, 323...step angle information area, 330...table, 331...section information area, 332...pulse number information area, 333...step angle information area, 340...table, 341...section information area, 342...pulse number information area, 343...step angle information area, 400...control unit, L...axis, P1...closed valve position, P2...fully open position, Pc...current position, Pt...target position to move

Claims

1. An electrically operated valve having a valve body having a valve orifice, a valve element disposed opposite the valve orifice, a drive mechanism for moving the valve element in a direction opposite the valve orifice, and a control device for controlling the drive mechanism, the drive mechanism has a stepping motor, and the valve element is moved by rotation of the stepping motor; The control device a storage unit that stores pulse number information relating to pulse numbers assigned in order from the reference position to the fully open position of the valve element, and step angle information relating to step angles corresponding to each of the pulse numbers; a communication unit that receives a valve element movement command related to a target position of the valve element from an external device; a calculation unit that acquires the pulse numbers assigned to the range from the current position of the valve element to the target movement position; a rotation control unit that rotates the stepping motor by the step angle corresponding to each pulse number in the order of the pulse numbers assigned from the current position of the valve body to the movement target position, a first section, a second section, and a third section are set between the reference position and the fully open position of the valve body; a first angle is set to the step angle corresponding to the pulse number assigned to the first section; a second angle is set to the step angle corresponding to the pulse number assigned to the second section; a third angle is set to the step angle corresponding to the pulse number assigned to the third section; the first angle, the second angle, and the third angle are different from one another, the first angle is a step angle in a microstep operation obtained by dividing a full-step operation of the stepping motor by 1 / n, the second angle is a step angle in a microstep operation obtained by dividing a full-step operation of the stepping motor by 1 / m, the third angle is a step angle in a full-step operation of the stepping motor; a pulse speed when the valve element is in the first section is n times the pulse speed when the valve element is in the third section, A motor-operated valve, wherein a pulse speed when the valve element is in the second section is m times the pulse speed when the valve element is in the third section. Here, m and n are natural numbers of 2 or more, and m≠n.

2. the valve body has one tapered surface whose diameter decreases toward the valve port, 2. The motor-operated valve according to claim 1, wherein a flow rate is determined by a gap between the tapered surface and an inner peripheral surface of the valve port when the valve element is in the first section, the second section, or the third section.

3. An electrically operated valve having a valve body having a valve orifice, a valve element arranged opposite the valve orifice, a drive mechanism for moving the valve element in a direction opposite the valve orifice, and a control device for controlling the drive mechanism, the drive mechanism has a stepping motor, and the valve element is moved by rotation of the stepping motor; The control device a storage unit that stores pulse number information relating to pulse numbers assigned in order from the reference position to the fully open position of the valve element, and step angle information relating to step angles corresponding to each of the pulse numbers; a communication unit that receives a valve element movement command related to a target position of the valve element from an external device; a calculation unit that acquires the pulse numbers assigned to the range from the current position of the valve element to the target movement position; a rotation control unit that rotates the stepping motor by the step angle corresponding to each pulse number in the order of the pulse numbers assigned from the current position of the valve body to the movement target position, a first section and a second section are set between the reference position and the fully open position of the valve body; a first angle is set to the step angle corresponding to the pulse number assigned to the first section; a second angle is set to the step angle corresponding to the pulse number assigned to the second section; the first angle and the second angle are different, the first angle is a step angle in a microstep operation obtained by dividing a full-step operation of the stepping motor by 1 / n, the second angle is a step angle in a full-step operation of the stepping motor; A motor-operated valve, wherein a pulse rate when the valve element is in the first section is n times the pulse rate when the valve element is in the second section. Here, n is a natural number of 2 or more.

4. the valve body has one tapered surface whose diameter decreases toward the valve port, The motor-operated valve according to claim 3 , wherein the flow rate is determined by a gap between the tapered surface and an inner circumferential surface of the valve port when the valve element is in the first section or the second section.

5. An electrically operated valve having a valve body having a valve port, a valve element disposed opposite the valve port, a drive mechanism that moves the valve element in a direction opposite the valve port, and a control device that controls the drive mechanism, the drive mechanism has a stepping motor, and the valve element is moved by rotation of the stepping motor; The control device a storage unit that stores pulse number information relating to pulse numbers assigned in order from the reference position to the fully open position of the valve element, and step angle information relating to step angles corresponding to each of the pulse numbers; a communication unit that receives a valve element movement command related to a target position of the valve element from an external device; a calculation unit that acquires the pulse numbers assigned to the range from the current position of the valve element to the target movement position; a rotation control unit that rotates the stepping motor by the step angle corresponding to each pulse number in the order of the pulse numbers assigned from the current position of the valve body to the movement target position, The storage unit Start-up state pulse number information relating to pulse numbers assigned in order from the reference position to the fully open position of the valve body, and start-up state step angle information relating to step angles corresponding to each of the pulse numbers in the start-up state pulse number information; storing normal operation state pulse number information relating to pulse numbers assigned in order from the reference position to the fully open position of the valve body, and normal operation state step angle information relating to step angles corresponding to each of the pulse numbers in the normal operation state pulse number information; The control device In a start-up state, the start-up state pulse number information and the start-up state step angle information are used as the pulse number information and the step angle information, The motor-operated valve uses the normal operation state pulse number information and the normal operation state step angle information as the pulse number information and the step angle information when in a normal operation state after the startup state.

6. The motor-operated valve according to claim 5 , wherein the control device transitions to the normal operation state when the communication unit receives a normal operation start command from an external device while the control device is in the activated state.

7. 7. The motor-operated valve according to claim 5, wherein the control device transitions to the normal operating state when the valve element moves to a predetermined activation completion position in the activated state.

Images