JPH0217278A - Device for controlling opening/closing of motor-driven valve - Google Patents

Abstract

PURPOSE:To increase starting torque and surely carry out valve opening by outputting valve opening pulses from the closed condition of a control valve at a low frequency. CONSTITUTION:An opening/closing signal output circuit 62 for controlling the opening/closing of a control valve 4 and a starting valve-opening circuit 67 which can output starting valve-opening pulses for opening the control valve 4 up to a previously set defined opening at the time of receiving a valve opening command signal at a lower frequency than that of the opening/closing pulses from the opening/closing signal output circuit 62 are provided in a motor driving circuit 7. Thereby, starting torque can be increased to surely open the control valve.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an opening/closing control device for various electric valves such as an electric expansion valve provided in a refrigerant circuit, and particularly relates to measures for improving starting torque.

(Prior art) Generally, the refrigerant circuit of an air conditioner is
As disclosed in Japanese Patent No. 70578, an expansion valve is provided between the condenser and the evaporator to expand the high-pressure refrigerant and supply it to the evaporator. The expansion valve is connected to a pulse motor to form an electric expansion valve, and the refrigerant pressure discharged from the evaporator is detected by a pressure sensor, and the pulse motor is controlled by a controller to control opening and closing of the expansion valve.

Since the pulse motor reversibly rotates to a certain angle depending on the number of energizing pulses, the opening degree of the expansion valve can be accurately controlled. When controlling the pulse motor, it is necessary to set a reference position for the valve opening relative to the output of the opening/closing pulse. Therefore, the fully closed state of the expansion valve is set as the reference position. In other words, at initialization to start control, the number of pulses corresponding to the full open/close range from fully open to fully open is output to the pulse motor as fully closed pulses. Since the motor rotates only the magnetic field and does not rotate the rotor, it is possible to set an accurate reference position in a fully closed state.

(Problems to be Solved by the Invention) In the electric expansion valve described above, when the valve closing pulse is energized to the pulse motor with the expansion valve fully open, the rotor does not rotate, and when the valve opening pulse is energized next, the expansion valve The valve is to open accurately according to the number of pulses.

However, when the valve-closing pulse is applied to the pulse motor from the fully closed state of the expansion valve, the valve body is pressed further against the valve seat than when seated on the valve seat, resulting in a so-called augmented state. That is, as shown in FIG. 5A, the number of valve-opening pulses ps that fully closes the expansion valve is larger than the number of valve-opening pulses PO that opens the expansion valve from the fully open state (see B and C), and the valve body Assuming that the valve-closing pulse that is energized after the valve seats on the valve seat is an augmented pulse, as the number of augmented pulses increases, the number of valve-opening pulses Po increases and the hysteresis increases, as shown in Figure 6. . Furthermore, as shown in FIG. 7E, as the number of supplementary pulses increases, the valve opening torque at startup increases, and the expansion valve may not open reliably.
There was a problem in that accurate opening/closing control could not be performed, resulting in poor air conditioning comfort.

The present invention has been made in view of the above, and aims to increase the starting torque and ensure the valve opens by outputting a valve opening pulse from the fully closed state of the control valve at a low frequency. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the means taken by the invention according to claim (1) are as shown in FIG. The present invention is based on an electrically operated valve comprising: and a motor (5) that is controlled by energizing pulses and opens and closes the control valve (4).

Then, a valve opening pulse and a valve closing pulse of a predetermined frequency are outputted to the drive circuit (7) of the motor (5) to drive the motor (5).
) is provided with opening/closing signal output means (62) for controlling the opening and closing of the control valve (4). Further, an opening/closing signal output means (6) for closing the control valve (4) to a fully open state is provided.
When a valve opening command signal is received from the fully open state of the control valve (4) after outputting the full open pulse in step 2), the opening/closing signal outputs a starting valve opening pulse to open the control valve (4) to a preset predetermined opening degree. The configuration includes a starting valve opening means (67) that outputs at a low frequency lower than the frequency of the opening/closing pulse outputted by the output means (62).

In addition, the means taken by the invention according to claim (2) are defined in claim (2).
In the invention of 1), the control valve (4) is constituted by an expansion valve installed in the refrigerant circuit (1) of the air conditioner, and the opening/closing signal output means (62) generates a fully closed pulse at the time of initialization. a reference setting means (64) for outputting and setting an opening reference position in the fully open state of the control valve (4); and a valve opening command means (63) for outputting a valve opening command signal and a valve closing command signal.
).

Further, the activation valve opening means (67) is configured to receive a valve opening command signal and output a activation valve opening pulse when the control valve (4) is opened from a fully closed state.

(Function) With the above configuration, in the inventions according to claims (1) and (2), for example, the expansion valve (4) provided in the refrigerant circuit (1)
The opening and closing of the motor (5) is controlled by rotating the motor (5) in forward and reverse directions according to the valve opening pulse and valve closing pulse of the opening/closing signal output means (62). Then, the opening/closing signal output means (62) outputs a full open pulse during initialization, etc., and the reference setting means (64) sets a reference position.

Thereafter, when the valve opening command means (63) outputs a valve opening command signal, the activation valve opening means (67) outputs up to a predetermined valve opening pulse at a low frequency.
) normally outputs an opening/closing pulse at 200 pps, but outputs a valve opening pulse at 150 pps to open the expansion valve (4) from the fully closed state.

(Effect of the invention) Therefore, according to the invention according to claim (1), the control valve (4
) Since the valve opening pulse from the fully closed state is output at a low frequency, the starting torque can be increased, so the control valve (4) can be reliably opened, especially when the control valve (4) is in the augmented state. This means that the valve will open reliably even when the temperature is reached, and accurate flow control can be performed.

Further, according to the invention according to claim 2, the refrigerant circuit (1)
Since the expansion valve (4) provided in the air conditioner can be reliably opened, comfortable air conditioning control can be performed.

(Embodiment fl) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

As shown in Fig. 2, (1) is a refrigerant circuit in a separate air conditioner, in which an outdoor unit (2) and an indoor unit (3) are connected, and the cooling cycle and heating cycle are reversibly operated. configured to be possible.

The outdoor unit (2) includes a compressor (21), a four-way switching valve (22), and an outdoor heat exchanger (23) on the heat source side that functions as a condenser during the cooling cycle and as an evaporator during the heating cycle.
) and an electric expansion valve (24) which is an electric valve, and the respective devices (21) to (24) are connected to each other through a refrigerant pipe (11) so that refrigerant can freely flow therethrough. Furthermore, a temperature sensor (
25) is provided, and the temperature sensor (25) detects the suction pipe temperature.

Further, the indoor unit (3) is configured to include an indoor heat exchanger (31) on the user side that serves as an evaporator during the cooling cycle and as a condenser during the heating cycle, and the indoor heat exchanger (31) is equipped with a refrigerant. A pipe (11) is connected. and,
The outdoor unit (2) and the indoor unit (3) are connected in a closed circuit by a refrigerant pipe (11), and during the cooling cycle, the four-way switching valve (22) is switched as shown by the solid line in Figure 2 to supply the refrigerant. The air is circulated as shown by the solid line arrow to cool and condition the room, while during the heating cycle, the four-way switching valve (2
2) is switched as shown by the broken line in Figure 2 to circulate the refrigerant as shown by the broken line arrow, thereby heating and air-conditioning the room. still,
In FIG. 2, (26) is an outdoor fan, and (32) is an indoor fan.

As shown in FIG. 3, the electric expansion valve (24) has a length of 1 m, and a pulse motor (5) is linked to the expansion valve (4). (41a) is bored, and the refrigerant pipe (1) is opened at both ends of the flow path (41a).
1) is connected, while the valve seat (4) is connected to the flow path (41a).
2), and a valve body (43) that can be freely seated on the valve seat (42). Furthermore, the valve body (43)
A valve shaft (44) is connected to the valve shaft (44), and the valve body (44) is connected to the valve shaft (44).
A bellows (45) is provided between the valve body (41) and the valve body (43) to keep the valve body (43) airtight.
) has a screw member (4) screwed onto the valve body (41).
6) are in contact with each other. An output shaft (47) is connected to the screw member (46), and the output shaft (47) is connected to the motor shaft (51) of the pulse motor (5) via a gear mechanism (48). The rotation of the pulse motor (5) is reduced by the gear mechanism (48) and the screw member (46)
This is converted into a linear movement in the vertical direction, and the valve body (43) opens and closes.

The pulse motor 5 is controlled by the energizing pulse output from the opening/closing control device 6, and the controller (61) of the opening/closing control device (6) receives the suction pipe temperature from the temperature sensor (25) and monitors the degree of superheating. It is configured to calculate and store the valve opening degree of the expansion valve (4) and the like.

Then, the output signal of the controller (61) is manually inputted to the opening/closing signal output circuit (62) which is the opening/closing signal output means,
A valve opening command circuit (63), which is a valve opening command means provided in the opening/closing signal output circuit (62), is configured to output a valve opening command signal or a valve closing command signal. Furthermore, the command signal of the valve opening command circuit (63) and the controller (
In response to the output signal of the opening/closing signal output circuit (62)
) outputs a predetermined number of valve opening pulses or valve closing pulses at a predetermined frequency to the drive circuit (7) of the pulse motor (5), and drives the pulse motor (5) in the forward and reverse directions to drive the expansion valve (4). ) is configured to control opening and closing, for example,
The number of pulses in the full opening/closing range from the fully open state to the fully open state of the expansion valve (4) is set to 2000 pulses, and these valve opening pulses and valve closing pulses are set at 200 pps (pulse p
er 5econd).

Further, the open/close signal output circuit (62) is provided with a reference setting circuit (64) which is a reference setting means, and the reference setting circuit (64) generates a fully closed pulse at the time of initializing the control program, for example, to eliminate errors. Considering this, a control signal is output to the drive circuit (7) of the pulse motor (5) to fully close the expansion valve (4) by outputting 2050 fully closed pulses, which are more than the number of pulses in the fully open/close range. In this state, a reference position with an opening degree of 21 is set.

Further, the opening/closing control device (6) includes a secondary opening output circuit (65) which is a secondary valve opening signal output means and a secondary valve closing signal output circuit (66) which is a secondary valve closing signal output means. It is provided. The secondary valve opening signal output circuit (65) is configured to output a secondary valve opening pulse when the opening/closing signal output circuit (62) outputs a fully closed pulse, that is,
After outputting the fully closed pulse at initialization and after outputting the fully closed pulse at the end of the operation, a secondary valve opening pulse of 150 pulses is applied to the motor drive circuit (7) to slightly open the expansion valve (4). is configured to print. The secondary valve closing signal output circuit (66) outputs a secondary valve closing pulse after the secondary valve opening signal output circuit (65) outputs the secondary valve opening pulse. The valve pulse is 150 pulses, which is the same number of pulses as the secondary valve opening pulse, and is designed to bring the expansion valve (4) into the fully closed state again.

Further, the opening/closing control device (6) is provided with a starting valve opening circuit (67) which is a starting valve opening means, and the starting valve opening circuit (67) is configured so that the opening/closing signal output circuit (62) is fully closed. After outputting the pulse, when a valve opening command signal is received from the valve opening command circuit (63) when the expansion valve (4) is in a fully closed state, the starting valve opening pulse is output at a low frequency. In other words, the starting valve opening circuit (67) has a pulse frequency (200p) that the opening/closing signal output circuit (62) outputs only when starting the valve opening.
starting valve opening pulse (e.g. 10 pps) up to a preset valve opening at a frequency lower than 150 pps
0 pulse) is output to the motor drive circuit (7).

Next, the heating and cooling operation of this air conditioner will be explained.

First, during the cooling cycle, as shown by the solid line in Figure 2, the four-way switching valve (22) is switched to circulate the refrigerant, which radiates heat through the outdoor heat exchanger (23) and transfers heat to the indoor heat exchanger (31). While heating occurs, during the heating cycle, the four-way switching valve (22) is switched to circulate the refrigerant, as shown by the broken line in Figure 2.
Heat is generated in the outdoor heat exchanger (23) and transferred to the indoor heat exchanger (31)
It dissipates heat and air-conditions the room.

In this refrigerant circuit (1), a temperature sensor (2
5) detects the suction pipe temperature of the compressor (21), and upon receiving the refrigerant pressure signal, the controller (61) calculates the degree of superheat and controls the electric expansion valve (24). Therefore, the opening/closing control of the electric expansion valve (24) will be explained based on the control flow shown in FIG. 4.

First, in step ST'l, when the power is turned on,
Moving on to step ST2, initialization is performed, and the open/close signal output circuit (62) outputs a fully closed pulse to the motor drive circuit (7) according to the control signal of the reference setting circuit (64), and the expansion valve is driven by the pulse motor (5). (4) Operate fully closed. In other words, the full-close pulse CPr+△P), which is the sum of the full-open/close pulse PT (2000 pulses) that operates the expansion valve (4) from fully closed to fully open, and the augmented pulse △P (50 pulses) that takes into account errors, etc., is used at the normal frequency. f2 (200
pps).

After outputting this full opening pulse (PT+ΔP), the secondary valve opening signal output circuit (65) outputs the secondary valve opening pulse PA to the motor drive circuit (7), and for example, outputs 150 pulses and temporarily outputs the expansion valve (4). ) is slightly opened. Subsequently, after outputting the secondary valve opening pulse PA, the secondary valve closing signal output circuit (66)
outputs a secondary valve closing pulse P8 to the pulse motor (5) to fully open the expansion valve (4) again. At this time, since the expansion valve (4) opens from the fully open state, the secondary valve opening pulse P^ is generated at a low frequency f+ (for example, 150 pps) lower than the normal frequency f2 by the control signal of the startup valve opening circuit (67). Output. Then, a reference position is set when the expansion valve (4) is in a fully closed state, and, for example, the step position is set to 0, and thereafter a valve opening pulse and a valve closing pulse are output.

Next, the process moves to step ST3, and it is determined whether or not there is a valve open signal, and the process waits until the valve open signal is received. If there is a valve open signal, the process moves from step ST3 to step ST4, and the above-mentioned open/close signal output circuit ( In response to the fully closed pulse (PT+∆P) of 62), the valve opening circuit (67) starts and activates the valve opening command circuit (63).
outputs a valve opening command signal, the starting valve opening pulse Pc up to a predetermined pulse Pc (for example, 100 pulses) is generated at a low frequency f1 (lower than the normal frequency 12 (200 pps)).
150 pps), increases the starting torque of the pulse motor (5), performs a starting compensated valve opening operation, and outputs a valve opening pulse at the normal frequency f2 until the set opening after the predetermined pulse Pc. ) to open the expansion valve (4) to the set opening degree.

The process moves from step ST4 to step ST5, and the expansion valve (4) is controlled in the normal mode. That is, the controller (61) outputs a control signal so that the degree of superheat reaches a predetermined value based on the suction pipe temperature of the temperature sensor (25), and this control signal causes the valve opening command circuit (63) to open or open the valve. A valve closing command signal is output, and the rA opening/closing signal output circuit 62) outputs a valve opening pulse or a valve closing pulse at a normal frequency f2. This causes the pulse motor (5) to rotate forward and reverse, causing the valve body (4
3) moves up and down, the expansion valve (4) is adjusted to the set opening degree,
The refrigerant flow rate is controlled in proportion to the number of pulses. after that,
Proceeding to step ST6, it is determined whether or not there is a fully closed signal, and the process returns to step ST5 until there is a fully open signal, while
When there is a full-open signal to fully open the expansion valve (4), the process moves from step ST6 to step ST7. Then, when the valve opening command circuit (63) outputs a full open command signal via the controller (61) in the case of ending air conditioning control, etc., the opening/closing signal output circuit (62) increases the number of pulses for the current opening. The fully closed pulse obtained by adding the pulse △P is the normal frequency f
2, the output is sent to the motor drive circuit (7) to fully open the expansion valve (4). After outputting this fully closed pulse, the secondary valve opening signal output circuit (65)
The starting valve opening circuit (67) outputs the secondary valve opening pulse pA at a low frequency f1, and then the secondary valve closing signal output circuit (67) outputs the secondary valve opening pulse pA at a low frequency f1.
66) outputs a secondary valve closing pulse P8 at the normal frequency f2 to slightly open the expansion valve (4) and then fully open it.

Subsequently, the process returns to step ST3, and it is determined whether or not the valve opening signal has been output. If the valve opening signal is output again, the process moves to step ST4, while if the power is cut off, etc., the opening/closing control is ended. Then, when the power is turned on again, the operation from step ST1 described above will be performed.

Therefore, after the opening/closing signal output circuit (62) outputs the fully closed pulse, the secondary valve opening signal output circuit (65) and the secondary valve closing signal output circuit (66) each output the expansion valve (4).
) is opened once and then fully closed again, so
Even if the augmented pulse ΔP is output to the pulse motor (5), the influence of the augmented pulse ΔP can be eliminated, and as shown in FIG. 5A, the valve closing pulse PS that fully opens the expansion valve (4)
The expansion valve (4) can be opened with the same number of valve opening pulses as the number of pulses, and hysteresis can be substantially eliminated. Therefore, locking of the valve body (43), etc. can be reliably prevented, and the flow rate of the refrigerant can be accurately controlled, allowing comfortable air conditioning control.

Further, as shown in the sixth diagram, the valve opening pulse increases as P increases to the augmented pulse, but as shown at point D1, the increase in the valve opening pulse can be prevented.

In particular, when the power supply is continuously turned on and off, conventionally initialization is performed continuously and all the full-open pulses (PT+ΔP) are augmented pulses, but the influence of these augmented pulses can be eliminated.

Furthermore, as shown in Fig. 7E, the starting torque at the time of opening the valve increases as the number of supplementary pulses increases, but it is possible to reduce the starting torque to within the E1 range, and moreover, the starting torque at the time of opening the valve increases. Since the starting torque is increased in circuit (67),
The valve can be opened reliably.

Moreover, as shown in FIG. 8 F1-F4, the augmented pulse Δ
If the expansion valve (4) is left unattended after P is energized, the starting torque will increase as the number of days it is left unused, but the rate of increase can be reduced and accurate starting can be ensured.

In this embodiment, the secondary valve opening pulse PA and the secondary valve closing pulse pa were set to 150 pulses, but the present invention is not limited to this. It suffices if (4) is the number of pulses that slightly open the valve, and 2
The next valve closing pulse ps may be any pulse number that causes the expansion valve (4) to close.

Furthermore, in step ST5 in FIG. 4, if the augmented Hals ΔP is small, it is not necessary to energize the secondary valve opening pulse PA and the secondary valve closing pulse P8.

Further, the frequency of the secondary valve opening pulse PA may be the normal frequency f2.

Further, the electric valve of the present invention is not limited to the electric expansion valve (24), but can be applied to various control valves, and the motor may be one that is controlled by pulses.

Further, in the present invention, the secondary valve opening signal output circuit (65
) and the secondary valve closing signal output circuit (66) are not necessarily provided, but are preferably provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 8 show an embodiment of the present invention, FIG. 2 is a refrigerant circuit diagram, FIG. 3 is a vertical cross-sectional view of the electric expansion valve, and FIG. 4 is a control showing the opening and closing operation of the electric expansion valve. It is a flow diagram. Figure 5 is a flow rate characteristic diagram for the opening/closing pulse near full opening, Figure 6 is a diagram of changes in the valve opening pulse for the augmented pulse, Figure 7 is a characteristic diagram of the valve opening torque required for activation in response to the augmented pulse, and Figure 8 is for the left-open state. It is a change diagram of the valve opening torque required for starting with respect to the number of days. (1)...refrigerant circuit, (4)...expansion valve, (5)...
...Pulse motor, (6)...Opening/closing control device, (7)
...Motor drive circuit, (24) ...Electric expansion valve, (
25) Temperature sensor, (42) Valve seat, (43
)... Valve body, (61)... Controller, (62)
...Opening/closing signal output circuit, (63)...Valve opening command circuit, (64)...Reference setting circuit, (65)...Secondary valve opening signal output circuit, (66)... Secondary valve closing signal output circuit, (67)...Start valve opening circuit. Patent applicant Daikin Industries, Ltd. Representative Patent attorney 1) Hiroshi. -Other 2
Name diagram diagram diagram diagram Reitoku pulse diagram diagram

Claims (2)

[Claims] (1) A motor-operated valve comprising a control valve (4) that controls fluid, and a motor (5) that is controlled by an energization pulse and opens and closes the control valve (4), wherein the motor (5) is driven. an opening/closing signal output means (62) that outputs a valve opening pulse and a valve closing pulse of a predetermined frequency to the circuit (7) to rotate the motor (5) in the forward and reverse directions to control the opening and closing of the control valve (4); When a valve opening command signal is received from the fully closed state of the control valve (4) after the open/close signal output means (62) outputs a fully closed pulse that closes the valve (4) to a fully closed state, the control valve (4) is opened to a preset predetermined value. Starting valve opening means (67) outputs a starting valve opening pulse to open the control valve (4) at a low frequency lower than the frequency of the opening/closing pulse outputted by the opening/closing signal output means (62).
), and an opening/closing control device for an electric valve. (2) The control valve (4) is composed of an expansion valve installed in the refrigerant circuit (1) of the air conditioner, while the open/close signal output means (62) outputs a fully closed pulse at initialization to control the above. A reference setting means (64) for setting an opening reference position when the valve (4) is fully open, and a valve opening command means (63) for outputting a valve opening command signal and a valve closing command signal, Claim (1) characterized in that the starting valve opening means (67) is configured to receive a valve opening command signal from the fully closed state of the control valve (4) and outputting a starting valve opening pulse. Opening/closing control device for electric valves.