Electric valve control device, electric valve device, and method for controlling electric valve

Patent metadata

Field	Value
Publication number	US-12449057-B2
Application number	US-202318832401-A
Country	US
Kind code	B2
Filing date	Jan 30, 2023
Priority date	Feb 14, 2022
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

An electric valve control device inputs pulses to a stepping motor to rotate a rotor in a second direction; inputs pulses to the stepping motor to rotate the rotor in a first direction when the electric valve is in a second-direction-rotation restricted state; obtains the number of pulses (an input number (Xi)) input to the stepping motor from the second-direction-rotation restricted state to a first-direction-rotation restricted state when the electric valve is in the first-direction-rotation restricted state while the rotor rotates in the first direction; determines that the rotor can rotate normally when the input number (Xi) is greater than or equal to a design number (Xd) and is smaller than or equal to an upper limit number (Xu); and determines that the rotor cannot rotate normally when the input number (Xi) is smaller than the design number (Xd) or is greater than the upper limit number (Xu).

First claim

The invention claimed is:

1. An electric valve control device for controlling an electric valve including a valve body that has a valve port, a stepping motor that includes a rotor, a valve member that moves toward the valve port when the rotor rotates in a first direction and moves away from the valve port when the rotor rotates in a second direction, a first stopper mechanism that restricts rotation of the rotor in the first direction when the rotor is at a reference position, and a second stopper mechanism that restricts rotation of the rotor in the second direction when the rotor is at a full-open position, a state where the rotation of the rotor in the first direction is restricted being a first-direction-rotation restricted state, a state where the rotation of the rotor in the second direction is restricted being a second-direction-rotation restricted state, a number of pulses in design input to the stepping motor when the rotor is rotated from the full-open position to the reference position being a design number,
wherein
(1) the electric valve control device is configured to input pulses to the stepping motor to rotate the rotor in the second direction,
(2) the electric valve control device is configured to input pulses to the stepping motor to rotate the rotor in the first direction when the electric valve is in the second-direction-rotation restricted state while the rotor is rotated in the second direction,
(3) the electric valve control device is configured to obtain a number of pulses, which is an input number, input to the stepping motor in a period from the second-direction-rotation restricted state to the first-direction-rotation restricted state when the electric valve is in the first-direction-rotation restricted state while the rotor is rotated in the first direction,
(4) the electric valve control device is configured to determine that the rotor is able to rotate normally when the input number is greater than or equal to the design number and is smaller than or equal to an upper limit number that is greater than the design number, and
(5) the electric valve control device is configured to determine that the rotor is unable to rotate normally when the input number is smaller than the design number or is greater than the upper limit number.

2. The electric valve control device according to claim 1 ,
wherein the electric valve control device is configured to obtain a voltage generated in a stator of the stepping motor by rotation of the rotor, and
wherein the electric valve control device is configured to determine whether the electric valve is in the first-direction-rotation restricted state and whether the electric valve is in the second-direction-rotation restricted state, based on at least one of (i) an area of a waveform of the voltage, (ii) an amplitude of a wave periodically observed in the waveform of the voltage, and (iii) a periodic appearance of a new wave distinct from the wave periodically observed in the waveform of the voltage.

3. The electric valve control device according to claim 2 ,
wherein the stator includes an A-phase stator and a B-phase stator,
wherein driving currents corresponding to pulses input to the stepping motor are supplied to the A-phase and B-phase stators, and
wherein the electric valve control device is configured to obtain a voltage generated in one of the A-phase and B-phase stators when the driving current is supplied only to the other of the A-phase and B-phase stators.

4. An electric valve device comprising:
the electric valve; and
the electric valve control device according to claim 1 .

5. An electric valve control device for controlling an electric valve including a valve body that has a valve port, a stepping motor that includes a rotor, a valve member that moves toward the valve port when the rotor rotates in a first direction and moves away from the valve port when the rotor rotates in a second direction, a first stopper mechanism that restricts rotation of the rotor in the first direction when the rotor is at a reference position, and a second stopper mechanism that restricts rotation of the rotor in the second direction when the rotor is at a full-open position, a state where the rotation of the rotor in the first direction is restricted being a first-direction-rotation restricted state, a state where the rotation of the rotor in the second direction is restricted being a second-direction-rotation restricted state, a number of pulses in design input to the stepping motor when the rotor is rotated from the reference position to the full-open position being a design number,
wherein
(1) the electric valve control device is configured to input pulses to the stepping motor to rotate the rotor in the first direction,
(2) the electric valve control device is configured to input pulses to the stepping motor to rotate the rotor in the second direction when the electric valve is in the first-direction-rotation restricted state while the rotor is rotated in the first direction,
(3) the electric valve control device is configured to obtain a number of pulses, which is an input number, input to the stepping motor in a period from the first-direction-rotation restricted state to the second-direction-rotation restricted state when the electric valve is in the second-direction-rotation restricted state while the rotor is rotated in the second direction,
(4) the electric valve control device is configured to determine that the rotor is able to rotate normally when the input number is greater than or equal to the design number and is smaller than or equal to an upper limit number that is greater than the design number, and
(5) the electric valve control device is configured to determine that the rotor is unable to rotate normally when the input number is smaller than the design number or is greater than the upper limit number.

6. A method for controlling an electric valve including a valve body that has a valve port, a stepping motor that includes a rotor, a valve member that moves toward the valve port when the rotor rotates in a first direction and moves away from the valve port when the rotor rotates in a second direction, a first stopper mechanism that restricts rotation of the rotor in the first direction when the rotor is at a reference position, and a second stopper mechanism that restricts rotation of the rotor in the second direction when the rotor is at a full-open position, a state where the rotation of the rotor in the first direction is restricted being a first-direction-rotation restricted state, a state where the rotation of the rotor in the second direction is restricted being a second-direction-rotation restricted state, a number of pulses in design input to the stepping motor when the rotor is rotated from the full-open position to the reference position being a design number,
the method comprising:
(1) inputting pulses to the stepping motor to rotate the rotor in the second direction;
(2) inputting pulses to the stepping motor to rotate the rotor in the first direction when the electric valve is in the second-direction-rotation restricted state while the rotor is rotated in the second direction;
(3) obtaining a number of pulses, which is an input number, input to the stepping motor in a period from the second-direction-rotation restricted state to the first-direction-rotation restricted state when the electric valve is in the first-direction-rotation restricted state while the rotor is rotated in the first direction;
(4) determining that the rotor is able to rotate normally when the input number is greater than or equal to the design number and is smaller than or equal to an upper limit number that is greater than the design number; and
(5) determining that the rotor is unable to rotate normally when the input numb

Assignees

• Fujikoki Corp

Inventors

• Hagimoto Hiroshi
• Ishizuka Yusuke

Classifications

• H02P8/24

  Arrangements for stopping (H02P8/32 takes precedence) · CPC title

• F16K31/046 Primary

  with electric means, e.g. electric switches, to control the motor or to control a clutch between the valve and the motor (F16K31/041 takes precedence) · CPC title

• F16K37/0041

  for measuring valve parameters (F16K37/0033 takes precedence) · CPC title

• F16K31/50

  with screw-spindle {or internally threaded actuating means} · CPC title

• F25B41/35

  by rotary motors, e.g. by stepping motors · CPC title