Motorised valve

Abstract

Provided is an electric valve capable of obtaining a desired flow rate characteristic regardless of the shape of a valve core. A control device (200) of an electric valve (1) stores pulse number information related to pulse numbers assigned sequentially from a closed valve position to a fully open position of a valve core (40) and step angle information related to a step angle corresponding to each of the pulse numbers. The control device (200) receives a valve core movement command related to a movement target position of the valve core (40) from a control unit (400). The control device (200) acquires a pulse number assigned from a current position of the valve core (40) to the movement target position. Also, the control device (200) causes a step motor to rotate at a step angle corresponding to each pulse number in the order of the pulse numbers assigned from the current position of the valve core to the movement target position.

Description

Technical Field

[0001] This invention relates to electric valves used, for example, in the refrigeration cycle of an air conditioner. Background Technology

[0002] Patent Document 1 discloses a conventional electric valve. The electric valve of Patent Document 1 has a valve core and a stepper motor. The valve core is opposite to the valve port. The valve core moves in the opposite direction to the valve port by the rotation of the stepper motor.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 8-268030

[0006] The problem that the invention aims to solve

[0007] In the electric valve described above, the stepper motor rotates according to pulses. The rotation angle (step angle) of the stepper motor for each pulse is constant, and the amount of movement of the valve core for each pulse is also constant. Therefore, the flow characteristics of the electric valve depend on the shape of the valve core, and to obtain the desired flow characteristics, a valve core with a shape corresponding to the flow characteristics needs to be used. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide an electric valve that can obtain the desired flow characteristics regardless of the shape of the valve core.

[0009] Methods for solving problems

[0010] To achieve the above objectives, the electric valve of the present invention comprises: a valve body having a valve port; a valve core opposite to the valve port; a drive mechanism that moves the valve core in a direction relative to the valve port; and a control device that controls the drive mechanism, wherein the drive mechanism has a stepper motor that moves the valve core by rotating the stepper motor; the control device comprises: a storage unit that stores pulse number information associated with pulse numbers sequentially assigned from a reference position to a fully open position of the valve core, and step angle information associated with a step angle corresponding to each of the pulse numbers; a communication unit that receives a valve core movement command associated with a target position of the valve core from an external device; a calculation unit that obtains the pulse numbers assigned from the current position of the valve core to the target position; and a rotation control unit that causes the stepper motor to rotate in the order of the pulse numbers assigned from the current position of the valve core to the target position, with a step angle corresponding to each pulse number.

[0011] In this invention, preferably, a first interval, a second interval, and a third interval are set between the reference position of the valve core and the fully open position. A first angle is set for the step angle corresponding to the pulse number assigned to the first interval, a second angle is set for the step angle corresponding to the pulse number assigned to the second interval, and a third angle is set for the step angle corresponding to the pulse number assigned to the third interval. The first angle, the second angle, and the third angle are different from each other.

[0012] In this invention, preferably, the first angle is the step angle in the full stepping motion of the stepper motor multiplied by 1 / n in the microstepping motion; the second angle is the step angle in the full stepping motion of the stepper motor multiplied by 1 / m in the microstepping motion; and the third angle is the step angle in the full stepping motion of the stepper motor. Wherein, m and n are natural numbers greater than or equal to 2, and m ≠ n.

[0013] In this invention, preferably, the valve core has a conical surface whose diameter decreases as it moves toward the valve port, and the flow rate is determined by the gap between the conical surface and the inner circumferential surface of the valve port when the valve core is located in the first interval, the second interval, or the third interval.

[0014] In this invention, preferably, the pulse velocity when the valve core is in the first interval is n times the pulse velocity when the valve core is in the third interval, and the pulse velocity when the valve core is in the second interval is m times the pulse velocity when the valve core is in the third interval.

[0015] In this invention, preferably, a first interval and a second interval are set between the reference position of the valve core and the fully open position, a first angle is set for the step angle corresponding to the pulse number assigned to the first interval, and a second angle is set for the step angle corresponding to the pulse number assigned to the second interval, wherein the first angle and the second angle are different.

[0016] In this invention, preferably, the first angle is the step angle in the micro-stepping motion multiplied by 1 / n of the stepper motor's full-stepping motion, and the second angle is the step angle in the stepper motor's full-stepping motion. Wherein, n is a natural number greater than or equal to 2.

[0017] In this invention, preferably, the valve core has a conical surface whose diameter decreases as it moves toward the valve port, and when the valve core is located in the first interval or the second interval, the flow rate is determined by the gap between the conical surface and the inner circumferential surface of the valve port.

[0018] In this invention, preferably, the pulse velocity when the valve core is located in the first interval is n times the pulse velocity when the valve core is located in the second interval.

[0019] In this invention, preferably, the storage unit stores: start-up state pulse number information, which is related to pulse numbers sequentially assigned from the reference position of the valve core to the fully open position; start-up state step angle information, which is related to a step angle corresponding to each of the pulse numbers in the start-up state pulse number information; normal operation state pulse number information, which is related to pulse numbers sequentially assigned from the reference position of the valve core to the fully open position; and normal operation state step angle information, which is related to a step angle corresponding to each of the pulse numbers in the normal operation state pulse number information. 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 during the start-up state, and the control device 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 during the normal operation state following the start-up state.

[0020] In this invention, it is preferable that if the communication unit receives a normal operation start command from an external device during the startup state, the control device transitions to the normal operation state.

[0021] In this invention, preferably, if the valve core moves to a predetermined start-up completion position during the start-up state, the control device transitions to the normal operating state.

[0022] Invention Effects

[0023] According to the present invention, the control device of the electric valve stores pulse number information related to pulse numbers sequentially assigned from the reference position to the fully open position of the valve core, and step angle information related to the step angle corresponding to each of the pulse numbers. The control device receives a valve core movement command related to the target position of the valve core from an external device. The control device obtains the pulse numbers assigned from the current position of the valve core to the target position. Furthermore, the control device causes the stepper motor to rotate in the order of the pulse numbers assigned from the current position of the valve core to the target position, with a step angle corresponding to each pulse number. Thus, the electric valve can individually set the step angle for each pulse assigned from the reference position to the fully open position of the valve core, and can adjust the amount of valve core movement (i.e., the change in the flow rate of refrigerant flowing through the valve orifice) for each pulse. Therefore, in the electric valve, the desired flow characteristics can be obtained regardless of the shape of the valve core. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of an electric valve according to an embodiment of the present invention.

[0025] Figure 2 yes Figure 1 A cross-sectional view of the stator unit of an electric valve.

[0026] Figure 3 yes Figure 1 An enlarged cross-sectional view of the valve core and its vicinity when the valve core of the electric valve is in the closed position.

[0027] Figure 4 yes Figure 1 An enlarged cross-sectional view of the valve core and its vicinity when the valve core of the electric valve is in the fully open position.

[0028] Figure 5 It is shown Figure 1 A graph showing the relationship between valve opening degree and flow rate in an electric valve.

[0029] Figure 6 This is an explanation Figure 1 A diagram showing the positional relationship between the magnetic rotor and stator of an electric valve.

[0030] Figure 7 yes Figure 1 Functional block diagram of an electric valve.

[0031] Figure 8 It is shown and stored in Figure 1 A table showing the pulse number information and step angle information of the control device for the electric valve.

[0032] Figure 9 This is an explanation Figure 8 The table shows the relationship between the pulse numbers assigned from the closed position to the fully open position and the position of the valve core.

[0033] Figure 10 It is shown Figure 1 The electric valve is based on a stepper motor. Figure 8 A graph showing the relationship between the position of the valve core and the flow rate during rotation.

[0034] Figure 11 It is shown Figure 8 A diagram showing a variation of the table.

[0035] Figure 12 This is an explanation Figure 11 The table shows the relationship between the pulse numbers assigned from the closed position to the fully open position and the position of the valve core.

[0036] Figure 13 It is shown Figure 1 The electric valve is based on a stepper motor. Figure 11 A graph showing the relationship between the position of the valve core and the flow rate during rotation.

[0037] Figure 14 It is shown Figure 8 The diagram shows another variation of the table.

[0038] Figure 15 This is an explanation Figure 14 The table shows the relationship between the pulse numbers assigned from the closed position to the fully open position and the position of the valve core.

[0039] Figure 16 It is shown Figure 1 The electric valve is based on a stepper motor. Figure 14 A graph showing the relationship between the position of the valve core and the flow rate during rotation. Detailed Implementation

[0040] (Example)

[0041] The following is for reference Figures 1-10 An embodiment of the electric valve 1 of the present invention will be described. The electric valve 1 is, for example, assembled in the refrigeration cycle of an air conditioner and operates according 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.

[0042] Figure 1 This is a cross-sectional view of an electric valve according to an embodiment of the present invention. Figure 2 yes Figure 1 A cross-sectional view of the stator unit of an electric valve. Figure 3 , Figure 4 yes Figure 1 An enlarged cross-sectional view of the valve core and its surrounding area of ​​the electric valve. Figure 3 This indicates that the valve core is in the closed position. Figure 4 This shows the valve core in the fully open position. Figure 5 It is shown Figure 1 A graph showing the relationship between valve opening degree and flow rate for an electric valve. Figure 6 This is an explanation Figure 1 A diagram showing the positional relationship between the magnetic rotor and stator of an electric valve. Figure 6 A shows the state in which the magnetic poles of the magnetic rotor are opposite to the pole teeth of the A-phase stator. Figure 6 B indicates the state in which the magnetic poles of the magnetic rotor are opposite to the pole teeth of the B-phase stator. Figure 7 yes Figure 1 Functional block diagram of an electric valve. Figure 8 It is shown and stored in Figure 1 A table showing the pulse number information and step angle information of the control device for the electric valve. Figure 9 This is an explanation Figure 8The table shows the relationship between the pulse numbers assigned from the closed position to the fully open position and the position of the valve core. Figure 10 It is shown Figure 1 The electric valve is based on a stepper motor. Figure 8 A graph showing the relationship between the position of the valve core and the flow rate during rotation.

[0043] like Figure 1 , Figure 2 As shown, the electric valve 1 has a valve body 10, a cover 20, a drive mechanism 30, and a valve core 40.

[0044] The valve body 10 is made of metal such as aluminum alloy. The valve body 10 has a main component 11, a support component 12, and a connecting component 13. The main component 11 has a cuboid shape. The main component 11 has a valve chamber 14 and flow paths 15 and 16. Flow path 15 is connected to the valve chamber 14. Flow path 16 is connected to the valve chamber 14 via a valve port 17. The valve port 17 is surrounded in the valve chamber 14 by an annular valve seat 18. A mounting hole 11a communicating with the valve chamber 14 is provided on the upper surface of the main component 11. The support component 12 has a cylindrical shape. The support component 12 is threaded into the mounting hole 11a of the main component 11. The upper part of the support component 12 protrudes from the upper surface of the main component 11. The connecting component 13 has an annular plate shape. The inner periphery of the connecting component 13 engages with the upper end of the support component 12.

[0045] The cover 20 is made of stainless steel or other metal. The cover 20 has a cylindrical shape with an open lower end and a closed upper end. The lower end of the cover 20 is engaged with the outer periphery of the connecting member 13.

[0046] The drive mechanism 30 moves the valve core 40 in the vertical direction (axis L direction). The drive mechanism 30 has a magnetic rotor 31, a valve shaft retainer 32, a guide bushing 33, a valve shaft 34, a permanent magnet 38, and a stator unit 50.

[0047] The magnetic rotor 31 has a cylindrical shape. The outer diameter of the magnetic rotor 31 is slightly smaller than the inner diameter of the cover 20. The magnetic rotor 31 has a plurality of N poles and a plurality of S poles. The plurality of N poles and the plurality of S poles are arranged on the outer peripheral surface of the magnetic rotor 31. The plurality of N poles and the plurality of S poles extend in the vertical direction. The plurality of N poles and the plurality of S poles are arranged alternately at equal angular intervals in the circumferential direction. In this embodiment, the magnetic rotor 31 has twelve N poles and twelve S poles. The angle between adjacent N poles and S poles is 15 degrees.

[0048] The valve shaft retainer 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 shaft retainer 32. The support ring 35 connects the magnetic rotor 31 to the valve shaft retainer 32. An internal thread 32c is formed on the inner circumferential surface of the valve shaft retainer 32.

[0049] The guide bushing 33 has a base 33a and a valve shaft support 33b. Both the base 33a and the valve shaft support 33b are cylindrical. The base 33a is pressed into a fitting hole 12a formed in the support member 12. The outer diameter of the valve shaft support 33b is smaller than the outer diameter of the base 33a. The inner diameter of the valve shaft support 33b is the same as the inner diameter of the base 33a. The valve shaft support 33b is coaxially connected to the upper end of the base 33a. An external thread 33c is formed on the outer circumferential surface of the valve shaft support 33b. The external thread 33c engages with the internal thread 32c of the valve shaft retainer 32. The guide bushing 33 is then joined to the support member 12.

[0050] The valve shaft 34 has a large-diameter portion 34a and a small-diameter portion 34b. Both portions 34a and 34b are cylindrical. The outer diameter of the large-diameter portion 34a is slightly smaller than the inner diameter of the guide bushing 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 passes through the valve shaft retainer 32. A push nut 36 for preventing disengagement is installed in the small-diameter portion 34b. The valve shaft 34 is disposed inside the guide bushing 33 and inside the support member 12. The valve shaft 34 is supported on the guide bushing 33 in a manner that allows it to slide vertically. The lower end of the valve shaft 34 is disposed in the valve chamber 14. The valve shaft 34 has a stepped portion 34c between the large-diameter portion 34a and the small-diameter portion 34b. The stepped portion 34c is an upward-facing annular plane. A valve-closing spring 37 is disposed between the valve shaft retainer 32 and the stepped portion 34c. The valve-closing spring 37 is a compression helical spring. The valve-closing spring 37 presses the valve shaft 34 downward.

[0051] A permanent magnet 38 is disposed above the magnetic rotor 31 on the inner side of the cover 20. The permanent magnet 38 has a ring-shaped plate. The permanent magnet 38 has one N pole and one S pole. The N pole is disposed in a portion of the permanent magnet 38 divided by its diameter, and the S pole is disposed in another portion. The permanent magnet 38 is fixed to the support ring 35 via a fastener 39. The permanent magnet 38 rotates together with the magnetic rotor 31.

[0052] The valve core 40 is integrally connected to the lower end of the large-diameter portion 34a of the valve shaft 34. The valve core 40 is disposed in the valve chamber 14. The valve core 40 and the valve port 17 are opposite each other in the vertical direction. The valve core 40 has a conical surface 41 whose diameter gradually decreases as it moves toward the valve port 17. The conical surface 41 extends from near the lower end of the large-diameter portion 34a of the valve shaft 34 along the axis L to the top end 40a of the valve core 40. The vertical direction is the direction in which the valve core 40 and the valve port 17 are opposite each other. In addition, the valve core 40 may also have multiple conical surfaces with different cone angles.

[0053] The valve core 40 moves vertically via the drive mechanism 30. The valve port 17 opens and closes due to the movement of the valve core 40. The valve core 40 moves from the closed position P1... Figure 3 Move to the fully open position P2 ( Figure 4 The closed position P1 is the position of the valve core 40 when the conical surface 41 contacts the valve seat 18. The closed position P1 is the reference position. The fully open position P2 is the position of the valve core 40, where the vertical position of the top tip 40a of the valve core 40 becomes the vertical position of the valve seat 18. In the electric 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 conical surface 41 and the inner circumferential surface of the valve port 17.

[0054] Figure 5 The graph illustrates the relationship between the valve opening degree and flow rate of electric valve 1. Valve opening degree is the position of valve core 40 relative to valve seat 18 (the amount of lift from the closed position P1). Valve opening degree is expressed as a percentage, with valve core 40 in the closed position P1 as 0% and valve core 40 in the fully open position P2 as 100%. Flow rate is the flow rate of refrigerant flowing in electric valve 1 (valve port 17). Flow rate is expressed as a percentage, with valve core 40 in the closed position P1 as 0% and valve core 40 in the fully open position P2 as 100%. In this embodiment, flow rate is expressed as a percentage relative to the Cv value. Figure 5 As shown, the basic flow characteristic of the electric valve 1 (valve core 40) is a linear characteristic in which the flow rate changes linearly proportionally to the valve opening. Alternatively, the valve core 40 may also have a basic flow characteristic such as an equal percentage characteristic.

[0055] The stator unit 50 includes a stator 60, a housing 70, a casing 80, a main substrate 90, a secondary substrate 100, a magnetic sensor 110, and a microcomputer 120.

[0056] The stator 60 has a cylindrical shape. The stator 60 has an A-phase stator 61, a B-phase stator 62, and a mold 63 made of synthetic resin.

[0057] The A-phase stator 61 has multiple claw-shaped pole teeth 61a and 61b on its inner circumferential side. The tips of pole teeth 61a face downwards, and the tips of pole teeth 61b face upwards. 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 twelve pole teeth 61a and twelve 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 become mutually opposite polarities.

[0058] The B-phase stator 62 has multiple claw-shaped pole teeth 62a and 62b on its inner circumferential side. The tips of pole teeth 62a face downwards, and the tips of pole teeth 62b face upwards. The pole teeth 62a and 62b are arranged alternately at equal angular intervals in the circumferential direction. In this embodiment, the B-phase stator 62 has twelve pole teeth 62a and twelve 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 become mutually opposite polarities.

[0059] Phase A stator 61 and Phase B stator 62 are coaxially arranged. Phase A stator 61 and Phase B stator 62 are in contact with each other. When viewed from the axis L, the angle between the pole teeth 61a of the adjacent Phase A stator 61 and the pole teeth 62a of the Phase B stator 62 is 7.5 degrees.

[0060] The mold 63 fills the inner sides of the A-phase stator 61 and the B-phase stator 62. Furthermore, the mold 63, together with the pole teeth 61a, 61b and 62a, 62b, forms the inner circumferential surface 60a of the stator. The diameter of the inner circumferential surface 60a is the same as the diameter of the outer circumferential surface of the cover 20. The mold 63 has a terminal support portion 64.

[0061] Terminal support portion 64 extends laterally (in a direction orthogonal to axis L) from phase A stator 61 and phase B stator 62. Terminal support portion 64 supports a plurality of terminals 65. The plurality of terminals 65 protrude laterally from the top of terminal support portion 64. The plurality of terminals 65 are connected to coil 61c of phase A stator 61 and coil 62c of phase B stator 62.

[0062] A cover 20 is disposed inside the stator 60. A magnetic rotor 31 is disposed inside the cover 20. The stator 60 and the magnetic rotor 31 constitute a stepper motor 66.

[0063] The stepper motor 66 is capable of both full-step and micro-step movements. A full-step movement occurs relative to a single pulse input, causing the magnetic rotor 31 to move from a position where its magnetic poles (N and S poles) are aligned with the pole teeth 61a and 61b of the A-phase stator 61. Figure 6 The magnetic pole is rotated to a position where it is opposite to the pole teeth 62a and 62b of phase B stator 62 located next to the pole teeth 61a and 61b. Figure 6 The action at the location shown in B, or from Figure 6 Rotate to position shown in B. Figure 6 The action at position A. In Figure 6 A, Figure 6In section B, black dots are marked on the reference magnetic poles and pole teeth. In this embodiment, the rotation angle (step angle) of each pulse during full-step operation is 7.5 degrees. Micro-stepping operation is the operation of rotating the magnetic rotor 31 relative to the input of a pulse by an angle obtained by equally dividing the step angle during full-step operation (the step angle during micro-stepping operation). Micro-stepping operation is performed by finely controlling the current value of the coil 61c of phase A stator 61 and the current value of the coil 62c of phase B stator 62. The step angle during micro-stepping operation is, for example, 0.9375 degrees (eighths), 1.875 degrees (quarters), or 1.5 degrees (quintillion).

[0064] In this embodiment, when the stepper motor 66 performs a full stepping motion of 500 pulses (3750 degrees of rotation of the magnetic rotor 31) with the valve core 40 in the closed position P1, the valve core 40 moves to the fully open position P2.

[0065] The outer casing 70 is made of synthetic resin. The outer casing 70 is injection molded. The outer casing 70 houses the stator 60. The outer casing 70 has a peripheral wall portion 71 and an upper wall portion 72.

[0066] The peripheral wall portion 71 has a cylindrical shape. A stator 60 is embedded in the central portion of the peripheral wall portion 71 in the vertical direction. The diameter of the inner peripheral surface 71a of the peripheral wall portion 71 is the same as the diameter of the inner peripheral surface 60a of the stator. The inner peripheral surface 71a and the inner peripheral surface 60a of the stator are connected without steps. 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 inner peripheral surface 60a of the stator define the inner space 74 of the stator unit 50. A cover 20 is disposed in the inner space 74. A support member 12 is disposed inside the lower portion 73 of the peripheral wall portion 71. An annular 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.

[0067] The outer casing 70 has a sub-substrate receiving space 75. The sub-substrate receiving space 75 extends laterally. The sub-substrate receiving space 75 is adjacent to the inner space 74. A partition 76 is disposed between the inner space 74 and the sub-substrate receiving space 75. The partition 76 divides the inner space 74 and the sub-substrate receiving space 75.

[0068] The housing 80 is made of synthetic resin. The housing 80 is injection molded. The housing 80 has a housing body 81, a cover 82, and a connector 83. The housing body 81 has one side (in... Figure 1 , Figure 2The housing body 81 has a rectangular box shape with an opening on the right side. The cover 82 has a flat plate shape. The cover 82 closes the opening on the side of the housing body 81. The connector 83 has an elliptical cylindrical shape. The connector 83 extends laterally from the top of the housing body 81. The housing body 81 and the connector 83 are integrally formed.

[0069] The housing body 81 has a side wall portion 84. The side wall portion 84 has a flat plate shape. The side wall portion 84 is laterally spaced from the cover 82. The side wall portion 84 has a rectangular housing opening 84a. The housing opening 84a is connected to the sub-base plate receiving space 75 of the outer casing 70. The periphery of the housing opening 84a in the side wall portion 84 is engaged with the outer casing 70.

[0070] The main substrate 90 is a printed circuit board for mounting electronic components. The main substrate 90 is disposed vertically inside the housing 80. A substrate connector 91 is disposed on the sidewall 84 side of the main substrate 90. A microcomputer 120 is mounted on the main substrate 90. Multiple terminals 65 of the stator 60 are connected to the main substrate 90.

[0071] Sub-substrate 100 is a printed circuit board for mounting electronic components. Sub-substrate 100 is laterally disposed within sub-substrate receiving space 75 of housing 70. Sub-substrate 100 is disposed at a right angle relative to main substrate 90. One end 100a of sub-substrate 100 is disposed near main substrate 90. The other end 100b of sub-substrate 100 is disposed near partition wall 76 of housing 70.

[0072] A substrate terminal 101 is disposed at one end 100a of the sub-substrate 100. The substrate terminal 101 is connected to the substrate connector 91 of the main substrate 90. The sub-substrate 100 is connected to the main substrate 90 via the substrate terminal 101 and the substrate connector 91.

[0073] 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 is laterally opposed to the permanent magnet 38 via the cover 20 and the partition 76. In other words, the magnetic sensor 110 is laterally aligned with the permanent magnet 38 via the cover 20 and the partition 76. The magnetic sensor 110 outputs a signal corresponding to the orientation of the magnetic field generated by the permanent magnet 38 (i.e., the rotation angle of the magnetic rotor 31 rotating together with the permanent magnet 38).

[0074] The microcomputer 120 is, for example, a microcomputer used in an assembly device that integrates a central processing unit, non-volatile memory, working memory, communication module, motor driver, etc., into a single package. The microcomputer 120 functions as a control device 200 that manages the control of the electric valve 1. The non-volatile memory, working memory, communication module, and motor driver can also be separate electronic components that are externally connected to the microcomputer 120.

[0075] like Figure 7 As shown, the control device 200 includes a storage unit 210, a communication unit 220, an arithmetic unit 230, and a rotation control unit 240. The storage unit 210 is composed of a non-volatile memory. The central arithmetic unit executes the program stored in the non-volatile memory, functioning as the communication unit 220, the arithmetic unit 230, and the rotation control unit 240. An operational memory temporarily stores variables such as the current position Pc of the valve core 40. The communication module is connected to the air conditioner control unit 400 via a cable (not shown) connected to connector 83. The motor driver is connected to the stepper motor 66 (coil 61c of phase A stator 61 and coil 62c of phase B stator 62).

[0076] Storage unit 210, for example, stores Figure 8 Table 310 is shown. Table 310 has an interval information area 311, a pulse number information area 312, and a step angle information area 313.

[0077] The interval information area 311 sets information related to the interval set between the closed position P1 and the fully open position P2 of the valve core 40. In the interval information area 311, as interval-related information, "first interval", "second interval" and "third interval" are set.

[0078] In the pulse number information area 312, information related to the pulse numbers assigned in ascending order from the closed position P1 to the fully open position P2 of the valve core 40 is set (pulse number information). In the pulse number information area 312, pulse numbers "1" to "1500" are set as pulse number information. Pulse numbers "1" to "800" are assigned to the "first interval" of the interval information area 311, pulse numbers "801" to "1200" are assigned to the "second interval", and pulse numbers "1201" to "1500" are assigned to the "third interval".

[0079] Figure 9 The relationship between the position of valve core 40 and pulse numbers is shown. The positions of valve core 40 are set in ascending order from the closed position P1 to the fully open position P2, from "0" to "1500". Furthermore, pulse numbers "1" to "1500" are assigned to the intervals between positions "0" and "1500". Pulse number "1" is assigned to the interval between position "0" and position "1", and pulse number "2" is assigned to the interval between position "1" and position "2", and so on. For example, when valve core 40 is in position "1", information related to pulse number "1" is used to move valve core 40 to position "0", and information related to pulse number "2" is used to move valve core 40 to position "2".

[0080] The step angle information area 313 sets information related to each corresponding step angle in the pulse number set in the pulse number information area 312 (step angle information). In the step angle information area 313, the number of step angle divisions in the entire stepping motion is set as 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". That is, the step angle (first angle) for the "first interval" is set to 7.5 degrees / 8 = 0.9375 degrees, the step angle (second angle) for the "second interval" is set to 7.5 degrees / 4 = 1.875 degrees, and the step angle (third angle) for the "third interval" is set to 7.5 degrees / 1 = 7.5 degrees. The stepper motor 66 has different step angles in the first, second, and third intervals. Furthermore, a numerical value representing the step angle can also be set as step angle information.

[0081] The storage unit 210 stores pulse number information and step angle information in a table format, but it can also store them in other formats such as mathematical formulas.

[0082] The electric valve 1 is rotated by a stepper motor 66 (magnetic rotor 31) based on table 310, thereby acting as a valve with... Figure 10 The electric valve with the flow characteristics shown is activated.

[0083] 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 forwards them to the arithmetic unit 230. The communication unit 220 obtains the status of the electric valve 1 from the arithmetic unit 230 and the rotation control unit 240 and sends it to the control unit 400. The communication unit 220 receives valve spool movement commands from the control unit 400. The valve spool movement command contains information related to the target position Pt of the valve spool 40. The target position Pt is specified as the valve opening degree. Alternatively, the target position Pt can also be specified as a relative movement distance (number of pulses, etc.) relative to the current position Pc of the valve spool 40. The current position Pc of the valve spool 40 is stored in the operating memory.

[0084] In electric valve 1, the valve opening degree specified by control unit 400 from 0% to 100% corresponds to the position of valve core 40 from 0% to 150%. Furthermore, when the number representing the current position Pc of valve core 40 is smaller than the number representing the target position Pt, the rotation direction of stepper motor 66 is the direction in which valve core 40 moves away from valve seat 18 (opening direction). When the number representing the current position Pc of valve core 40 is larger than the number representing the target position Pt, the rotation direction of stepper motor 66 is the direction in which valve core 40 approaches valve seat 18 (closing direction).

[0085] The arithmetic unit 230 performs various calculations. When the communication unit 220 receives a valve core movement command, the arithmetic unit 230 obtains the position of the valve core 40 corresponding to the valve opening specified by the movement target position Pt of the valve core movement command. For example, when the valve opening is 10%, the arithmetic unit 230 obtains position "150" as the movement target position Pt; when the valve opening is 50%, it obtains position "750" as the movement target position Pt; and when the valve opening is 90%, it obtains position "1350" as the movement target position Pt.

[0086] Furthermore, the arithmetic unit 230 acquires the pulse numbers between the current position Pc (starting point) and the target position Pt (end point) of the valve core 40. For example, when the current position Pc is position "0" and the target position Pt is position "150", the arithmetic unit 230 acquires pulse numbers "1" to "150". When the current position Pc is position "150" and the target position Pt is position "750", the arithmetic unit 230 acquires pulse numbers "151" to "750". When the current position Pc is position "750" and the target position Pt is position "300", the arithmetic unit 230 acquires pulse numbers "750" to "301".

[0087] In addition, the arithmetic unit 230 obtains the rotation angle of the magnetic rotor 31 based on the signal output by the magnetic sensor 110.

[0088] The rotation control unit 240 retrieves the step angle information corresponding to each pulse number from Table 310 in the order of pulse numbers assigned from the current position Pc of the valve core 40 to the target position Pt. Then, the rotation control unit 240 uses the step angle information to calculate the step angle and inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepper motor 66.

[0089] In the rotation control unit 240, the pulse speed when the valve core 40 is in the first interval is set to 8 times the pulse speed when the valve core 40 is in the third interval. In the rotation control unit 240, the pulse speed when the valve core 40 is in the second interval is set to 4 times the pulse speed when the valve core 40 is in the third interval. The pulse speed is represented by the number of pulses input per second (PPS). In this embodiment, the pulse speed when the valve core 40 is in the first interval is 1000 [PPS], the pulse speed when the valve core 40 is in the second interval is 500 [PPS], and the pulse speed when the valve core 40 is in the third interval is 125 [PPS].

[0090] Furthermore, the rotation control unit 240 determines the success or failure of the valve spool movement command. Specifically, the rotation control unit 240 compares the rotation angle of the magnetic rotor 31, which has accumulated the step angles corresponding to the pulse numbers allocated from the current position Pc to the target position Pt, with the rotation angle of the magnetic rotor 31 obtained by the calculation unit 230 based on the signal from the magnetic sensor 110. If these rotation angles match, the rotation control unit 240 sends information indicating a successful valve spool movement command as a 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 sends information indicating a failed valve spool movement command as a command execution result to the control unit 400 via the communication unit 220.

[0091] In the electric valve 1, the central axis of each of the support component 12, valve port 17, cover 20, magnetic rotor 31, valve shaft retainer 32, guide bushing 33, valve shaft 34, valve core 40 (conical surface 41), and stator 60 (A-phase stator 61 and B-phase stator 62) is aligned with the axis L.

[0092] Next, an example of the operation of electric valve 1 will be described.

[0093] When the power is turned on, the control device 200 of the electric valve 1 enters the start-up state. The control device 200 performs initialization processing in the start-up state. After moving the valve core 40 to the closed position P1, the control device 200 transitions to the normal operating state. At this time, the current position Pc of the valve core 40 is the closed position P1 (position "0" of the valve core 40). In the normal operating state, the control device 200 waits for commands from the control unit 400. The control unit 400 recognizes that the electric valve 1 has… Figure 10 The flow characteristics are shown.

[0094] For example, when the control device 200 receives a valve core movement command from the control unit 400 that includes a target movement position Pt with a specified valve opening degree of 90 [%), it acquires position "1350" as the target movement position Pt. Then, the control device 200 acquires the pulse numbers "1" to "1350" assigned from the current position Pc to the target movement position Pt.

[0095] Based on Table 310, the control device 200 calculates the step angle corresponding to pulse numbers "1" to "1350". Since the number representing the current position Pc (position "0") is smaller than the number representing the 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 stepper motor 66 (magnetic rotor 31). The valve shaft retainer 32 rotates together with the magnetic rotor 31. Through the threaded feed action of the internal thread 32c of the valve shaft retainer 32 and the external thread 33c of the guide bushing 33, the valve shaft retainer 32 moves upward. The valve shaft 34 moves upward together with the valve shaft retainer 32, and the valve core 40 leaves the valve seat 18.

[0096] The control device 200 inputs pulses at 1000 PPS in the first interval (pulse numbers "1" to "800"), at 500 PPS in the second interval (pulse numbers "801" to "1200"), and at 125 PPS in the third interval (pulse numbers "1201" to "1350"). Furthermore, the control device 200 accumulates the step angles corresponding to the pulse numbers up to "1350".

[0097] When the stepper motor 66 finishes rotating at the step angles corresponding to pulse numbers "1" to "1350", the control device 200 stores position "1350" as the current position Pc in the operating memory. Additionally, the control device 200 determines the success or failure of the valve spool movement command. Specifically, the control device 200 compares the rotation angle of the magnetic rotor 31 obtained by accumulating the step angles with the rotation angle of the magnetic rotor 31 obtained based on the signal from the magnetic sensor 110. If these rotation angles match, the control device 200 sends information indicating a successful valve spool movement command to the control unit 400 as a command execution result. If these rotation angles do not match, the control device 200 sends information indicating a failed valve spool movement command to the control unit 400 as a command execution result. Then, the control device 200 waits for the next command from the control unit 400.

[0098] Next, when the control device 200 receives a valve core movement command from the control unit 400 that includes a specified valve opening degree of 50 [%) and a target position Pt, it acquires position "750" as the target position Pt. Then, the control device 200 acquires the pulse numbers "1350" to "751" assigned from the current position Pc to the target position Pt.

[0099] Based on Table 310, the control device 200 calculates the step angle corresponding to pulse numbers "1350" to "751". Since the number representing the current position Pc (position "1350") is larger than the number representing the target position Pt (position "750"), the control device 200 sets the rotation direction to the "valve closing direction". The control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepper motor 66 (magnetic rotor 31). The valve shaft retainer 32 rotates together with the magnetic rotor 31. Through the threaded feed action of the internal thread 32c of the valve shaft retainer 32 and the external thread 33c of the guide bushing 33, the valve shaft retainer 32 moves downward. The valve shaft 34 moves downward together with the valve shaft retainer 32, and the valve core 40 approaches the valve seat 18.

[0100] The control device 200 inputs pulses at 125 [PPS] in the third interval (pulse numbers "1350" to "1201"), at 500 [PPS] in the second interval (pulse numbers "1200" to "801"), and at 1000 [PPS] in the first interval (pulse numbers "800" to "751"). Furthermore, the control device 200 accumulates the step angles corresponding to the pulse numbers up to "1350" to "751".

[0101] When the rotation of the stepper motor 66 at the step angle corresponding to pulse numbers "1350" to "751" ends, the control device 200 stores position "751" as the current position Pc in the operation memory. Additionally, the control device 200 determines the success or failure of the valve spool movement command and sends the command execution result to the control unit 400. Then, the control device 200 waits for the next command from the control unit 400. Afterward, the control device 200 performs the action corresponding to the received command.

[0102] The electric valve 1 of this embodiment includes: a valve body 10 having a valve port 17, a valve core 40 opposite to the valve port 17, a drive mechanism 30 for moving the valve core 40 in the vertical direction, and a control device 200 for controlling the drive mechanism 30. The drive mechanism 30 includes a stepper motor 66, and the valve core 40 is moved by rotating the stepper motor 66. The control device 200 includes a storage unit 210, a communication unit 220, an arithmetic unit 230, and a rotation control unit 240. The storage unit 210 stores pulse number information related to pulse numbers allocated in ascending order from the closed position P1 to the fully open position P2 of the valve core 40, and step angle information related to the step angle corresponding to each of the pulse numbers. The communication unit 220 receives a valve core movement command related to the target position Pt of the valve core 40 from the control unit 400. The arithmetic unit 230 obtains the pulse numbers allocated from the current position Pc of the valve core 40 to the target position Pt. The rotation control unit 240 causes the stepper motor 66 to rotate in the order of pulse numbers assigned from the current position Pc of the valve core 40 to the target position Pt, with a step angle corresponding to each pulse number.

[0103] Therefore, the electric valve 1 can individually set the step angle for each pulse distributed from the closed position P1 to the fully open position P2 of the valve core 40, and can adjust the amount of movement of the valve core 40 for each pulse (i.e., the change in the flow rate of the refrigerant flowing in the valve port 17). Thus, in the electric valve 1, the desired flow characteristics can be obtained regardless of the shape of the valve core 40.

[0104] Furthermore, in the electric valve 1, a first interval, a second interval, and a third interval are defined between the closed position P1 and the fully open position P2 of the valve core 40. A first angle (0.9375 degrees) is set for the step angle corresponding to the pulse number assigned to the first interval. A second angle (1.875 degrees) is set for the step angle corresponding to the pulse number assigned to the second interval. A third angle (7.5 degrees) is set for the step angle corresponding to the pulse number assigned to the third interval. Moreover, the first, second, and third angles are different from each other. Therefore, the electric valve 1 can obtain flow characteristics in three intervals with different flow rate variations for each pulse. The electric valve 1 can precisely control the flow rate within a relatively small valve opening range.

[0105] Furthermore, the first angle is the step angle in the full-step motion of the stepper motor 66 multiplied by 1 / n (n=8) in the micro-step motion. The second angle is the step angle in the full-step motion of the stepper motor 66 multiplied by 1 / m (m=4) in the micro-step motion. And the third angle is the step angle in the full-step motion of the stepper motor 66. Thus, the electric valve 1 can obtain flow characteristics in three intervals with different flow rate changes for each pulse through a relatively simple structure. m and n can be natural numbers of 2 or higher. Where m≠n.

[0106] Furthermore, the valve core 40 has a conical surface 41 whose diameter decreases as it moves toward the valve port 17. Moreover, when the valve core 40 is in the first, second, or third zone, the flow rate is determined by the gap between the conical surface 41 and the inner circumferential surface of the valve port 17. Thus, the electric valve 1 can obtain flow characteristics in three zones with different flow rate variations for each pulse using a valve core 40 of a relatively simple shape.

[0107] Furthermore, the pulse velocity of the valve core 40 when it is in the first interval (first interval pulse velocity) is 8 times that of the valve core 40 when it is in the third interval (third interval pulse velocity). Also, the pulse velocity of the valve core 40 when it is in the second interval (second interval pulse velocity) is 4 times that of the third interval. Therefore, the electric valve 1 can maintain the same movement speed of the valve core 40 in the first, second, and third intervals. Thus, compared to maintaining the same pulse velocity in the first, second, and third intervals, the valve core 40 can move from the closed position P1 to the fully open position P2 much faster.

[0108] Furthermore, when the movement of the valve core 40 in the first interval from the current position Pc to the target position Pt includes a first interval, and the number of pulses involved in the movement of the valve core 40 in the first interval exceeds a predetermined reference number of pulses (e.g., 100), the pulse speed in the first interval is 8 times the pulse speed in the third interval; when the number of pulses is less than the reference number, the pulse speed in the first interval is the same as the pulse speed in the third interval. Similarly, when the movement of the valve core 40 in the second interval from the current position Pc to the target position Pt includes a second interval, and the number of pulses involved in the movement of the valve core 40 in the second interval exceeds a reference number of pulses, the pulse speed in the second interval is 4 times the pulse speed in the third interval; when the number of pulses is less than the reference number, the pulse speed in the second interval is the same as the pulse speed in the third interval. Thus, when the movement of the valve core 40 in the first or second interval is large, the valve core 40 moves at a high speed, which can shorten the time spent switching the flow rate. In addition, when the movement of the valve core 40 in the first or second interval is small, the valve core 40 moves at a low speed, which can slowly switch the flow rate.

[0109] In addition, the electric valve 1 has flow characteristics in three intervals with different flow rate changes for each pulse, but it can also have other flow characteristics such as equal percentage characteristics by appropriately setting table 310.

[0110] (Modified Example)

[0111] Next, refer to Figures 11-16 The modified electric valves 1A and 1B of the above-described electric valve 1 will be described.

[0112] Figure 11 It is shown Figure 8 A diagram showing a variation of the table. Figure 12 This is an explanation Figure 11 The table shows the relationship between the pulse numbers assigned from the closed position to the fully open position and the position of the valve core. Figure 13 It is shown Figure 1 The electric valve is based on a stepper motor. Figure 11 A graph showing the relationship between the position of the valve core and the flow rate during rotation. Figure 14 It is shown Figure 8 The table shows other variations. Figure 15 This is an explanation Figure 14 The table shows the relationship between the pulse numbers assigned from the closed position to the fully open position and the position of the valve core. Figure 16 It is shown Figure 1 The electric valve is based on a stepper motor. Figure 14 A graph showing the relationship between the valve core position and flow rate (flow characteristics) during valve rotation. Figure 16 In the diagram, the dashed line represents the flow characteristics during startup, while the solid line represents the flow characteristics during normal operation. Figure 16 In the positions “650” to “1900”, the dashed lines and solid lines are recorded vertically and horizontally, but in reality they are consistent with each other.

[0113] The aforementioned electric valve 1 is based on the storage unit 210 of the control device 200. Figure 8 The table 310 shown causes the stepper motor 66 to rotate. Furthermore, the electric valve 1 has... Figure 11 Table 320 is used instead of Table 310 to create an electric valve 1A with different flow characteristics. The hardware structure of electric valve 1A is the same as that of electric valve 1.

[0114] In the electric valve 1A, the storage unit 210 stores... Figure 11 Table 320 is shown. Table 320 has an interval information area 321, a pulse number information area 322, and a step angle information area 323.

[0115] The interval information area 321 sets information related to the interval set between the closed position P1 and the fully open position P2 of the valve core 40. In the interval information area 321, as interval-related information, "second interval" and "first interval" are set.

[0116] In the pulse number information area 322, information related to the pulse numbers assigned in ascending order from the closed position P1 to the fully open position P2 of the valve core 40 is set (pulse number information). In the pulse number information area 322, pulse numbers "1" to "1500" are set as pulse number information. Pulse numbers "1" to "250" are assigned to the "second interval" of the interval information area 321, and pulse numbers "251" to "1500" are assigned to the "first interval".

[0117] Figure 12 The relationship between the position of valve core 40 and pulse number is shown. The positions of valve core 40 are set in ascending order from the closed position P1 to the fully open position P2, from "0" to "1500". Furthermore, pulse numbers "1" to "1500" are assigned to the intervals between positions "0" to "1500".

[0118] The step angle information area 323 sets information related to each corresponding step angle in the pulse number set in the pulse number information area 322 (step angle information). In the step angle information area 323, the number of step angle divisions in the entire stepping motion is set as 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". That is, the step angle (second angle) for the "second interval" is set to 7.5 degrees / 1 = 7.5 degrees, and the step angle (first angle) for the "first interval" is set to 7.5 degrees / 5 = 1.5 degrees. The stepper motor 66 has different step angles in the second interval and the first interval.

[0119] The electric valve 1A is rotated by a stepper motor 66 (magnetic rotor 31) based on table 320, thereby acting as a valve with… Figure 13 The electric valve with the flow characteristics shown is activated.

[0120] In electric valve 1A, the valve opening degree specified by control unit 400 from 0% to 100% corresponds to the position of valve core 40 from 0% to 150%.

[0121] In the rotation control unit 240, the pulse speed when the valve core 40 is in the first interval is set to 5 times the pulse speed when the valve core 40 is in the second interval. In the electric valve 1A, the pulse speed when the valve core 40 is in the first interval is 625 [PPS], and the pulse speed when the valve core 40 is in the second interval is 125 [PPS].

[0122] Next, an example of the operation of electric valve 1A will be explained.

[0123] When the power is turned on, the control device 200 of the electric valve 1A enters the start-up state. The control device 200 performs initialization processing in the start-up state. After moving the valve core 40 to the closed position P1, the control device 200 transitions to the normal operating state. At this time, the current position Pc of the valve core 40 is the closed position P1 (position "0" of the valve core 40). In the normal operating state, the control device 200 waits for commands from the control unit 400. The control unit 400 recognizes that the electric valve 1A has… Figure 13 The flow characteristics are shown.

[0124] For example, when the control device 200 receives a valve core movement command from the control unit 400 that includes a target movement position Pt with a specified valve opening degree of 90 [%), it acquires position "1350" as the target movement position Pt. Then, the control device 200 acquires the pulse numbers "1" to "1350" assigned from the current position Pc to the target movement position Pt.

[0125] Based on Table 320, control device 200 calculates the step angle corresponding to pulse numbers "1" to "1350". Since the number representing the current position Pc (position "0") is smaller than the number representing the target position Pt (position "1350"), control device 200 sets the rotation direction to the "valve opening direction". Control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepper motor 66. As a result, valve core 40 moves away from valve seat 18.

[0126] The control device 200 inputs pulses at 125 [PPS] in the second interval (pulse numbers "1" to "250") and at 625 [PPS] in the first interval (pulse numbers "251" to "1350"). Furthermore, the control device 200 accumulates the step angles corresponding to the pulse numbers up to "1" to "1350".

[0127] When the rotation of the stepper motor 66 at the step angle corresponding to pulse numbers "1" to "1350" ends, the control device 200 stores position "1350" as the current position Pc in the operation memory. Additionally, the control device 200 determines the success or failure of the valve spool movement command and sends the command execution result to the control unit 400. Then, the control device 200 waits for the next command from the control unit 400.

[0128] Next, when the control device 200 receives a valve core movement command from the control unit 400 that includes a target movement position Pt with a specified valve opening degree of 10 [%), it acquires position "150" as the target movement position Pt. Then, the control device 200 acquires the pulse numbers "1350" to "151" assigned from the current position Pc to the target movement position Pt.

[0129] Based on Table 320, control device 200 calculates the step angle corresponding to pulse numbers "1350" to "151". Since the number representing the current position Pc (position "1350") is larger than the number representing the target position Pt (position "150"), control device 200 sets the rotation direction to the "valve closing direction". Control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepper motor 66 (magnetic rotor 31). As a result, valve core 40 approaches valve seat 18.

[0130] The control device 200 inputs pulses at 625 [PPS] in the first interval (pulse numbers "1350" to "251") and at 125 [PPS] in the second interval (pulse numbers "250" to "151"). Furthermore, the control device 200 accumulates the step angle corresponding to the pulse numbers up to "1350" to "151".

[0131] When the rotation of the stepper motor 66 at the step angle corresponding to pulse numbers "1350" to "151" ends, the control device 200 stores position "150" as the current position Pc in the operation memory. Additionally, the control device 200 determines the success or failure of the valve spool movement command and sends the command execution result to the control unit 400. Then, the control device 200 waits for the next command from the control unit 400. Afterward, the control device 200 executes the action corresponding to the received command.

[0132] The electric valve 1A has the same function as the electric valve 1 mentioned above (including substantially the same function).

[0133] Furthermore, in the electric valve 1A, a first interval and a second interval are defined between the closed position P1 and the fully open position P2 of the valve core 40. A first angle (1.5 degrees) is set for the step angle corresponding to the pulse number assigned to the first interval. A second angle (7.5 degrees) is set for the step angle corresponding to the pulse number assigned to the second interval. The first angle and the second angle are different. Therefore, the electric valve 1A can obtain flow characteristics in two intervals with different flow rate variations for each pulse. The electric valve 1A can precisely control the flow rate within a relatively large valve opening range.

[0134] Furthermore, the first angle is the step angle in the micro-stepping motion of the stepper motor 66 multiplied by 1 / n (n=5) during its full-stepping motion. The second angle is the step angle in the full-stepping motion of the stepper motor 66. Thus, the electric valve 1A can obtain flow characteristics in two intervals with different flow rate variations for each pulse through a relatively simple structure. n can be any natural number greater than 2.

[0135] Furthermore, the valve core 40 has a conical surface 41 whose diameter decreases as it moves toward the valve port 17. And, when the valve core 40 is in the first or second section, the flow rate is determined by the gap between the conical surface 41 and the inner circumferential surface of the valve port 17. Thus, the electric valve 1A can obtain flow characteristics in two sections with different flow rate variations for each pulse using a valve core 40 of a relatively simple shape.

[0136] Furthermore, the pulse velocity of the valve core 40 when it is in the first zone is five times that when it is in the second zone. Therefore, the electric valve 1A can maintain the same movement speed of the valve core 40 in both the first and second zones. Consequently, compared to maintaining the same pulse velocity in both zones, the valve core 40 can move from the closed position P1 to the fully open position P2 much faster.

[0137] Electric valve 1 via having Figure 14 Tables 330 and 340 shown are used instead Figure 8 Table 310 shows electric valve 1B with different flow characteristics. The hardware structure of electric valve 1B is the same as that of electric valve 1.

[0138] In the electric valve 1B, the storage unit 210 stores... Figure 14 Tables 330 and 340 are shown. Table 330 is used in the starting state immediately after the electric valve 1B is started. Table 340 is used in the normal operating state after the electric valve 1B has started.

[0139] Table 330 has an interval information area 331, a pulse number information area 332, and a step angle information area 333.

[0140] Information related to the interval set in the interval information area 331 is set between the closed position P1 and the fully open position P2 of the valve core 40. In the interval information area 331, "second interval" and "first interval" are set as interval-related information.

[0141] In the pulse number information area 332, information related to the pulse numbers assigned in ascending order from the closed position P1 to the fully open position P2 of the valve core 40 is set (pulse number information). In the pulse number information area 332, pulse numbers "401" to "1900" are set as pulse number information. Pulse numbers "401" to "650" are assigned to the "second interval" of the interval information area 331, and pulse numbers "651" to "1900" are assigned to the "first interval".

[0142] The step angle information area 333 sets information related to each corresponding step angle in the pulse number set in the pulse number information area 332 (step angle information). In the step angle information area 333, the number of step angle divisions in the entire stepping motion is set as step angle information. In the 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". That is, the step angle (second angle) for the "second interval" is set to 7.5 degrees / 1 = 7.5 degrees, and the step angle (first angle) for the "first interval" is set to 7.5 degrees / 5 = 1.5 degrees.

[0143] Table 340 includes an interval information area 341, a pulse number information area 342, and a step angle information area 343.

[0144] Information related to the interval set in the interval information area 341 is set between the closed position P1 and the fully open position P2 of the valve core 40. In the interval information area 341, "second interval" and "first interval" are set as interval-related information.

[0145] In the pulse number information area 342, information related to the pulse numbers assigned in ascending order from the closed position P1 to the fully open position P2 of the valve core 40 is set (pulse number information). In the pulse number information area 342, pulse numbers "1" to "1900" are set as pulse number information. Pulse numbers "1" to "150" are assigned to the "second interval" of the interval information area 341, and pulse numbers "151" to "1900" are assigned to the "first interval".

[0146] The step angle information area 343 sets information related to each corresponding step angle in the pulse number set in the pulse number information area 342 (step angle information). In the step angle information area 343, the number of step angle divisions in the entire stepping motion is set as step angle information. In the 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". That is, the step angle (second angle) for the "second interval" is set to 7.5 degrees / 1 = 7.5 degrees, and the step angle (first angle) for the "first interval" is set to 7.5 degrees / 5 = 1.5 degrees.

[0147] Figure 15 This shows the relationship between the position of valve core 40 and the pulse number. Figure 15 In Table 330, the valve core 40 positions "400" to "1900" are set in ascending order from the valve closed position P1 to the fully open position P2, and the first and second intervals are represented by dashed lines during startup. Solid lines represent the valve closed position P1, fully open position P2, the first interval, and the second interval during normal operation. Corresponding to Table 330 used during startup, the positions of the valve core 40 from "400" to "1900" are set in ascending order from the valve closed position P1 to the fully open position P2. Pulse numbers "401" to "1900" are assigned to the intervals between positions "400" to "1900". Similarly, corresponding to Table 340 used during normal operation, the valve core 40 positions "0" to "1900" are set in ascending order from the valve closed position P1 to the fully open position P2. Pulse numbers "1" to "1900" are assigned to the intervals between positions "0" to "1900".

[0148] The pulse number information set in pulse number information area 332 of Table 330 and the step angle information set in step angle information area 333 are the start-up state pulse number information and start-up state step angle information. The pulse number information set in pulse number information area 342 of Table 340 and the step angle information set in step angle information area 343 are the normal operation state pulse number information and normal operation state step angle information. The start-up state pulse number information is set with pulse numbers "401" to "1900", and the normal operation state pulse number information is set with pulse numbers "1" to "1900". Therefore, the start-up state pulse number information and the normal operation state pulse number information are different from each other. In addition, "1" is assigned to the pulse numbers "401" to "650" of the start-up state pulse number information as the start-up state step angle information, and "5" is assigned to the pulse numbers "651" to "1900" of the start-up state pulse number information as the start-up state step angle information. Furthermore, pulse numbers "1" to "150" in the normal operation state pulse numbering information are assigned "1" as the normal operation state step angle information, and pulse numbers "151" to "1900" in the normal operation state pulse numbering information are assigned "5" as the normal operation state step angle information. Therefore, the start-up state step angle information and the normal operation state step angle information are different from each other. Alternatively, the start-up state pulse numbering information and the normal operation state pulse numbering information can be the same, but the start-up state step angle information and the normal operation state step angle information can be different from each other.

[0149] In the electric valve 1B, when the communication unit 220 receives a normal operation start command from the control unit 400, the calculation unit 230 transitions from the start-up state to the normal operation state. In the start-up state, the valve opening degree 0% to 100% specified by the control unit 400 corresponds to the positions "400" to "1900" of the valve core 40. In the normal operation state, the valve opening degree 0% to 100% specified by the control unit 400 corresponds to the positions "0" to "1900" of the valve core 40. Furthermore, when the communication unit 220 receives a valve core movement command in both the start-up state and the normal operation state, the calculation unit 230 obtains the position of the valve core 40 corresponding to the valve opening degree specified by the movement target position Pt of the valve core movement command. In the start-up state, for example, when the valve opening is 10%, the calculation unit 230 acquires position "550" as the target position Pt; when the valve opening is 50%, it acquires position "1150" as the target position Pt; and when the valve opening is 80%, it acquires position "1600" as the target position Pt. In the normal operation state, for example, when the valve opening is 10%, the calculation unit 230 acquires position "190" as the target position Pt; when the valve opening is 50%, it acquires position "950" as the target position Pt; and when the valve opening is 80%, it acquires position "1520" as the target position Pt.

[0150] Next, an example of the operation of electric valve 1B will be described.

[0151] The control device 200 of the electric valve 1B uses the meter 330 to rotate the stepper motor 66 in the starting state, and uses the meter 340 to rotate the stepper motor 66 in the normal operating state.

[0152] When the power is turned on, the control device 200 of the electric valve 1B enters the start state. The control device 200 performs initialization processing in the start state. The control device 200 moves the valve core 40 to the closed position P1. At this time, the current position Pc of the valve core 40 is the closed position P1 (position "400" of the valve core 40). In the start state, the control device 200 waits for commands from the control unit 400. The control unit 400 recognizes that the electric valve 1B has [operations / functions] in the start state. Figure 16 The flow characteristics shown by the dashed line have the following under normal operating conditions: Figure 16 The solid line represents the flow characteristics.

[0153] For example, when the control device 200 receives a valve core movement command from the control unit 400 that includes a target movement position Pt with a specified valve opening degree of 80 [%), it acquires position "1600" as the target movement position Pt. Then, the control device 200 acquires the pulse numbers "401" to "1600" assigned from the current position Pc to the target movement position Pt.

[0154] Based on Table 330, control device 200 calculates the step angle corresponding to pulse numbers "401" to "1600". Since the number representing the current position Pc (position "400") is smaller than the number representing the target position Pt (position "1600"), control device 200 sets the rotation direction to the "valve opening direction". Control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepper motor 66. As a result, valve core 40 moves away from valve seat 18.

[0155] The control device 200 inputs pulses at 125 [PPS] in the second interval (pulse numbers "401" to "650") and at 625 [PPS] in the first interval (pulse numbers "651" to "1600"). Furthermore, the control device 200 accumulates the step angles corresponding to the pulse numbers up to "401" to "1600".

[0156] When the rotation of the stepper motor 66 at the step angle corresponding to pulse numbers "401" to "1600" ends, the control device 200 stores position "1600" as the current position Pc in the operation memory. Additionally, the control device 200 determines the success or failure of the valve spool movement command and sends the command execution result to the control unit 400. Then, the control device 200 waits for the next command from the control unit 400.

[0157] Next, when the control device 200 receives a normal operation start command from the control unit 400, it transitions from the start state to the normal operation state. By transitioning to the normal operation state, the control device 200 uses table 340 instead of table 330.

[0158] Next, when the control device 200 receives a valve core movement command from the control unit 400 that includes a specified valve opening degree of 50 [%), it acquires position "950" as the target position Pt. Then, the control device 200 acquires the pulse numbers "1600" to "951" assigned from the current position Pc to the target position Pt.

[0159] Based on Table 340, control device 200 calculates the step angle corresponding to pulse numbers "1600" to "951". Since the number representing the current position Pc (position "1600") is larger than the number representing the target position Pt (position "950"), control device 200 sets the rotation direction to the "valve closing direction". Control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepper motor 66. As a result, valve core 40 approaches valve seat 18.

[0160] The control device 200 inputs pulses at 625 [PPS] in the first interval (pulse numbers "1600" to "951"). Additionally, the control device 200 accumulates the step angles corresponding to the pulse numbers up to "1600" to "951".

[0161] When the rotation of the stepper motor 66 at the step angle corresponding to pulse numbers "1600" to "951" ends, the control device 200 stores position "951" as the current position Pc in the operation memory. Additionally, the control device 200 determines the success or failure of the valve spool movement command and sends the command execution result to the control unit 400. Then, the control device 200 waits for the next command from the control unit 400.

[0162] Next, when the control device 200 receives a valve core movement command from the control unit 400 that includes a target position Pt with a specified valve opening degree of 0 [%], it acquires position "0" as the target position Pt. Then, the control device 200 acquires the pulse numbers "950" to "1" assigned from the current position Pc to the target position Pt.

[0163] Based on Table 340, control device 200 calculates the step angle corresponding to pulse numbers "950" to "1". Since the number representing the current position Pc (position "950") is larger than the number representing the target position Pt (position "0"), control device 200 sets the rotation direction to the "valve closing direction". Control device 200 inputs the pulse, step angle, and rotation direction to the motor driver to rotate the stepper motor 66. As a result, valve core 40 contacts valve seat 18.

[0164] The control device 200 inputs pulses at 625 [PPS] in the first interval (pulse numbers "950" to "151") and at 125 [PPS] in the second interval (pulse numbers "150" to "1"). Furthermore, the control device 200 accumulates the step angles corresponding to the pulse numbers from "950" to "1".

[0165] When the rotation of the stepper motor 66 at the step angle corresponding to pulse numbers "950" to "1" ends, the control device 200 stores position "0" as the current position Pc in the operation memory. Additionally, the control device 200 determines the success or failure of the valve spool movement command and sends the command execution result to the control unit 400. Then, the control device 200 waits for the next command from the control unit 400. Afterward, the control device 200 executes the action corresponding to the received command.

[0166] Electric valve 1B has the same (including substantially the same) function as electric valve 1 and electric valve 1A mentioned above.

[0167] Additionally, storage unit 210 stores tables 330 and 340. The control device uses the pulse number information and step angle information set in table 330 (start-up state pulse number information and start-up state step angle information) in the start-up state, and uses the pulse number information and step angle information set in table 340 (normal operation state pulse number information and normal operation state step angle information) in the normal operation state. Therefore, the electric valve 1B can change its flow characteristics during operation, allowing for flexible adaptation to the requirements of the system in which the electric valve 1B is assembled.

[0168] Furthermore, if a normal operation start command is received from the control unit 400 during the start-up state, the control device 200 transitions to the normal operation state. Thus, the control unit 400 can change the operation state of the control device 200. Therefore, compared to the case where the control device 200 changes its operation state autonomously, it is possible to prevent inconsistencies between the operation state of the control device 200 known to the control unit 400 and the actual operation state of the control device 200.

[0169] Furthermore, if the valve core 40 moves to a predetermined start-up completion position during the start-up state (e.g., Figure 16 If the position is "650" in the middle, the control device 200 can also autonomously switch to the normal operating state.

[0170] The electric valve 1 is a direct-acting electric valve used in the drive mechanism 30 without slowing down the rotation of the magnetic rotor 31. However, the present invention can also be applied to electric valves with a drive mechanism that has a speed reduction mechanism that slows down the rotation of the magnetic rotor.

[0171] In this specification, the terms "cylinder," "cylindrical," etc., are also used for components and parts of components that substantially have the shape of that term. For example, "cylindrical-shaped component" includes both cylindrical-shaped components and components that are substantially cylindrical.

[0172] The embodiments of the present invention have been described above, but the present invention is not limited to the structure of the embodiments. Embodiments in which constituent elements are appropriately added, deleted, or designed in accordance with the foregoing embodiments, or embodiments in which features of the embodiments are appropriately combined, are included within the scope of the present invention, provided they do not violate the spirit of the present invention.

[0173] Explanation of reference numerals in the attached figures

[0174] 1, 1A, 1B… Electric valve, 10… Valve body, 11… Main body component, 11a… Mounting hole, 12… Support component, 12a… Fitting hole, 13… Connecting component, 14… Valve chamber, 15… Flow path, 16… Flow path, 17… Valve port, 18… Valve seat, 19… Sealing component, 20… Cover, 30… Drive mechanism, 31… Magnetic rotor, 32… Valve shaft retainer, 32c… Internal thread, 33… Guide bushing, 33a… Base, 33b… Valve shaft support, 33c… External thread, 34… Valve shaft, 34a… Large diameter section, 34b… Small diameter section, 34c… Stepped section, 35… Support 36…Push nut, 37…Closing valve spring, 38…Permanent magnet, 39…Fixed component, 40…Valve core, 40a…Top end, 41…Conical surface, 50…Stator unit, 60…Stator, 60a…Stator inner circumferential surface, 61…A-phase stator, 61a…Pole tooth, 61b…Pole tooth, 61c…Coil, 62…B-phase stator, 62a…Pole tooth, 62b…Pole tooth, 62c…Coil, 63…Mold, 64…Terminal support, 65…Terminal, 66…Stepper motor, 70…Housing, 71…Peripheral wall, 71a…Inner circumferential surface, 72…Upper wall, 72a…Inner surface, 7 3…Lower part, 74…Inner space, 75…Sub-board receiving space, 76…Partition wall, 80…Housing, 81…Housing body, 82…Cover, 83…Connector, 84…Side wall, 84a…Housing 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…Storage unit, 220…Communication unit, 230…Arithmetic unit, 240…Rotation control unit, 310…Table, 311…Interval information area, 312…Pulse number information area, 313…Step angle information area, 320…Table, 321…Interval information area, 322…Pulse number information area, 323…Step angle information area, 330…Table, 331…Interval information area, 332…Pulse number information area, 333…Step angle information area, 340…Table, 341…Interval 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…Moving target position.

Claims

1. An electric valve comprising: a valve body having a valve port; a valve core opposite to the valve port; a drive mechanism for moving the valve core in a direction relative to the valve port; and a control device for controlling the drive mechanism, characterized in that, The drive mechanism has a stepper motor, and the valve core is moved by the rotation of the stepper motor. The control device has: The storage unit stores pulse number information related to pulse numbers sequentially assigned from the reference position to the fully open position of the valve core, and step angle information related to the step angle corresponding to each of the pulse numbers. The communication unit receives valve core movement commands from external devices that are related to the target position of the valve core movement. The arithmetic unit obtains the pulse number assigned from the current position of the valve core to the moving target position; as well as A rotation control unit causes the stepper motor to rotate at a step angle corresponding to each pulse number, in sequence according to the pulse numbers assigned from the current position of the valve core to the target moving position. A first interval, a second interval, and a third interval are defined between the reference position of the valve core and the fully open position. A first angle is set for the step angle corresponding to the pulse number assigned to the first interval. A second angle is set for the step angle corresponding to the pulse number assigned to the second interval. A third angle is set for the step angle corresponding to the pulse number assigned to the third interval. The first angle, the second angle, and the third angle are different from each other.

2. The electric valve according to claim 1, characterized in that, The first angle is the step angle in the full step motion of the stepper motor multiplied by the step angle in the micro-step motion, which is 1 / n. The second angle is the step angle in the full stepping motion of the stepper motor multiplied by the step angle in the microstepping motion of 1 / m. The third angle is the step angle during the full stepping motion of the stepper motor. Where m and n are natural numbers greater than 2, and m ≠ n.

3. The electric valve according to claim 1 or 2, characterized in that, The valve core has a conical surface whose diameter decreases as it faces the valve orifice. When the valve core is located in the first interval, the second interval, or the third interval, the flow rate is determined by the gap between the conical surface and the inner circumferential surface of the valve port.

4. The electric valve according to claim 2, characterized in that, The pulse velocity when the valve core is in the first interval is n times the pulse velocity when the valve core is in the third interval. The pulse velocity when the valve core is in the second interval is m times the pulse velocity when the valve core is in the third interval.

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