JPH0743188B2 - Switching valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a refrigeration cycle, and more particularly to a switching valve used for switching between cooling and heating of a heat pump type air conditioner.

2. Description of the Related Art As a conventional technique, there is a switching valve for a refrigeration cycle as disclosed in Japanese Patent Publication No. 35-12689.

Hereinafter, the configuration of the conventional refrigeration cycle switching valve described above will be described with reference to the drawings.

6 and 7 are sectional views of a conventional refrigeration cycle switching valve. Reference numeral 1 is a compressor, and 2 is an accumulator, which is connected via a switching valve 3 to the current circuits of an indoor heat exchanger 4, a capillary 5 and an outdoor heat exchanger 6. The switching valve 3 is composed of a switching valve body 7 and a pilot valve device 8.

Then, the switching valve body 7 has two pistons 9,
It is divided into three valve chambers 11, 12 and 13 by 10 and two pistons 9 and 10 are connected by a connecting rod 14 and simultaneously move left and right in FIG. 6, and a slide valve 15 is mounted on the connecting rod 14. The slide valve 15 moves in conjunction with the pistons 9 and 10.

In the area sandwiched by the pistons 9 and 10, four pipes 16,17,
18, 19 form an inlet 16a, an outlet 17a, a first passage 18a, and a second passage 19a.

The discharge pipe 16 of the compressor 1 has a valve chamber 12 through an inlet 16a.
The outlet port 17a of the suction pipe 17 of the compressor is always in communication with the flow path 21 formed by the slide valve 15 and the valve seat 20. The first passage 18a of the pipe 18 and the second passage 19a of the pipe 19 are connected to the indoor heat exchanger 4 and the outdoor heat exchanger 6, respectively.
12 or communicates with the flow path 21.

The pistons 9 and 10 have pressure balancing holes 22 and 23 formed therein.

Next, the structure of the pilot valve device 8 will be described.

Two valve chambers 24 and 25 are provided in the pilot device 8,
It has communication holes 29 which are alternately closed by needle valves 27 and 28 which are operated by a solenoid coil 26.

The needle valves 27 and 28 in FIG. 7 show the state where the solenoid coil is energized, that is, the heating state.

Reference numeral 30 is a thin tube that connects the communication hole 29 and the suction pipe 17, 31
Is a thin tube connecting the valve chamber 11 and the valve chamber 24, 32 is the valve chamber 13 and the valve chamber 25
Is a thin tube that communicates with.

The operation state of the refrigeration cycle switching valve configured as described above will be described below.

Fig. 7 shows the state of heating operation, and each valve chamber 11,12,1
The pressure of 3,24,25 is as follows.

The gas discharged from the compressor 1 causes the pressure in the valve chamber 12 to become high, and the compression balance holes 22 and 23 provided in the pistons 9 and 10 cause the valve chamber 1 to reach a high pressure.
Attempts to keep 1 and valve chamber 13 at high pressure. However, since the needle valve 27 in the pilot valve device 8 closes the communication hole 29, the valve chamber 13 communicates with the suction pipe 17 through the thin pipe 32, the valve chamber 25, the communication hole 29, and the thin pipe 30, and a low pressure is established. Has become. Therefore, a pressure difference occurs between the valve chambers 11 and 13 via the pistons 9 and 10, and the pistons 9 and 10 and the slide valve
15 is pressed to the right in the drawing to maintain a predetermined heating operation state.

Next, the operation of the switching valve 3 at the start of the cooling operation will be described.

In FIG. 6, the solenoid coil 26 is de-energized, so that the needle valves 27 and 28 move to the left in the drawing, the needle valve 28 closes the communication port 29, and the thin tube 30 closes the valve chamber 24.
To communicate with. Therefore, the valve chamber 11 that was at a high pressure during heating communicates with the suction pipe 17 via the thin tube 32, the valve chamber 24, and the thin tube 30, and suddenly becomes a low pressure. Therefore, a pressure difference is generated between the valve chamber 12 and the valve chamber 11 across the piston 9, and the pistons 9 and 10 and the slide valve 15 are pressed leftward in the drawing by the pressure difference, and the discharge pipe 16 and the pipe 19 are introduced. mouth
16a, the valve chamber 12, and the second communication port 19a communicate with each other, and the pipe 18 communicates with the suction pipe 17 through the first communication port 18a, the flow path 21, and the outlet 17a, and enters a cooling operation state.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above configuration, in each state of the heating operation and the cooling operation, the slide valve 15 is operated by the pressure difference between the high pressure refrigerant pressure in the valve chamber 12 and the low pressure refrigerant pressure in the flow passage 21. Sheet
Since it is pressed by an excessive force of 20, for example, when the switching operation is performed from the heating operation to the cooling operation or vice versa, the slide valve 15 is driven by the pilot method using the pressure difference of the refrigerant gas. . Therefore, an extremely large number of parts are required and the structure is complicated, so that the assembly process is complicated. I had a problem. Further, the thin tubes 30, 31, 32, the pressure balance holes 22, 23, the communication hole 29 of the pilot valve 8 and the like for performing the switching operation may be blocked by foreign matter in the refrigerant circuit, and the switching operation may be disabled. Therefore, there is a problem in that the reliability is unstable. Further, as one means for solving this, a method of immediately moving the sliding valve for switching the valve by an electromagnetic coil may be considered (not shown), but a large suction force is required to surely move the sliding valve. Therefore, an extremely large electromagnetic coil is required to obtain this attractive force as a continuous rating.
It has not been realized because it has a problem that power consumption also increases. Further, in order to improve this, JP-A-59-164472
In the official gazette, a switching valve using a positive temperature coefficient resistive element is presented, but with this, the power supply is momentarily shut off due to momentary power failure, etc., and when it is restored after that, the temperature of the element drops completely. Therefore, there is a problem that the operation becomes uncertain.

In view of the above problems, the present invention provides a low-cost, small-sized pilot valveless type switching valve that consumes less power and does not malfunction due to an instantaneous power failure.

Means for Solving the Problems In order to solve the above problems, a refrigeration cycle switching valve according to the present invention has a structure in which a fixed iron core of a solenoid portion for directly plunger-driving a sliding valve for switching a refrigerant circuit is divided and attached between them. Provided with a magnet that can be magnetized and demagnetized, a sensor that detects the temperature inside the room, a sensor that detects the temperature of the indoor heat exchanger, a sensor that detects the temperature outside the room, and a sensor that detects the temperature of the outdoor heat exchanger. , A switching circuit for switching between cooling operation and heating operation, a control circuit for inputting signals from the respective sensors and the switching switch and outputting a signal to an amplification circuit for a fixed time, and a signal from the control circuit for inputting and amplifying the magnetizing coil Also, an amplifier circuit for outputting a signal is connected to the degaussing coil.

Effect The present invention, by the above-mentioned configuration, inputs the signal of the changeover switch for switching the heating operation and the cooling operation in the control circuit and the signals of the indoor and indoor heat exchanger temperatures and the outdoor and outdoor heat exchanger temperatures, and the cooling operation is performed. It is determined whether the heating operation is performed, and a signal is output to the degaussing and magnetizing coil through the amplifier circuit to drive the switching valve.

Embodiment A four-way valve for a refrigeration cycle according to an embodiment of the present invention will be described below with reference to the drawings. Since the cooling system has the same configuration as the conventional one, the same reference numerals are given and detailed description thereof is omitted. 1 and 3 are cross-sectional views of a refrigeration cycle switching valve according to an embodiment of the present invention when the valve is not energized. Reference numeral 33 is a cylinder forming a valve body, and an inlet port 34a of a discharge pipe 34 connected to the discharge side of the compressor 1 is opened on the side surface. Reference numeral 35 is a lid fitted and welded to one end of the cylinder 33. Reference numerals 36 and 37 denote first and second valve seats having seat surfaces 36a and 37a fixed to the inner wall of the cylinder 33 so as to face each other in parallel. The first valve seat 36a is provided on the suction side of the compressor 1. Suction pipe 38 connected
The lead-out port 36b to is open. Further, the second pulp sheet 37 has first and second connection pipes 39, 40 connected to the outdoor heat exchanger 6 and the indoor heat exchanger 4 which reversibly function as a compressor or an evaporator, respectively. First and second openings 37 opened
b and 37c are opened in parallel in the axial direction of the cylinder 33. 41,
The reference numeral 42 designates, for example, PTFE (tetrafluoroethylene resin) having a good slidability that abuts and seals the valve seats 36a, 37a.
2 is a pair of slide valves to which slide seat rings 43 and 44 made of fluororesin are fixed. Reference numeral 45 denotes a slider that houses the slide valves 41 and 42 at both ends and forms a tunnel-shaped flow path. 46 is in the slider 45 and is interposed between the slide valves 41, 42 to urge the pair of slide valves 41, 42 to the valve seats 36, 37,
The slide seat rings 43, 44 to the valve seat 36,
A leaf spring that presses against 37 and seals the inside and outside. 47 and 48 are V-shaped seal rings housed in the central recesses of the outer circumferences of the slide valves 41 and 42 to seal between the sliders.
49 is a lid that closes the other end of the cylinder 33. Reference numeral 50 is a pipe attached to the center of the lid 49 coaxially with the cylinder 33. Reference numeral 51 is a plunger that is connected to the slider 45 at one end and is movable in the pipe in the axial direction.
Reference numeral 52 is a fixed iron core that faces the other end of the plunger 51 with the same axis center and is provided via a return spring 53, and closes the tip of the pipe. Reference numeral 54 is, for example, an alnico magnet which is inserted so as to divide the fixed iron core 52 in the axial direction and can be magnetized and demagnetized. Reference numeral 55 denotes a coil which is arranged outside the pipe 50 and has an axis substantially coincident with the axis. As shown in FIG. 4, signal input terminals 55a and 55b are provided, and 55c is drawn as a signal lead. , Is composed of a magnetizing coil 55d and a degaussing 55e wound in opposite directions. 56 is
It is a sensor for detecting the room temperature and outputs a signal S ₁ to the control circuit 61. 57 is a sensor for detecting the temperature of the indoor heat exchanger and is a control circuit
Output signal S ₂ to 61. An outdoor temperature detecting sensor 58 outputs a signal S ₃ to the control circuit 61. Reference numeral 59 is an outdoor heat exchanger temperature detection sensor, which outputs a signal S ₄ to the control circuit 61. The changeover switch 60 is a switch for switching between cooling operation and heating operation, and outputs an operation signal S ₅ to the control circuit 61. The control circuit 61 receives the signals S ₁ , S ₂ , S ₃ , S ₄ and the operation signal S _5, and is in the cooling operation state or the heating operation,
Judgment is made and signals S ₆ and S ₇ are output. Amplifier circuit, control circuit 61
The signals S ₆ and S _{7 from} are input, and the outputs are connected to the signal input terminals 55a and 55b of the magnetizing coil 55d and the degaussing coil 55e.

The positions of the slide seat rings 43 and 44 fixed to the ends of the slide valves 41 and 42 housed at both ends of the slider 45 are the same as those shown in FIGS. 51 In the non-adsorption state, the outlet 36b
And the first passage 37b are interlocked with each other, and the outlet 36b and the second passage 37c are communicated with each other at the second position (FIG. 2) where the plunger 51 and the slider 45 are absorbed by the energization of the magnetizing coil 55a. It is designed as

The operation of the refrigeration cycle switching valve configured as described above will be described below with reference to FIGS. 1 to 5. First
FIGS. 2A and 2B show a state of the plunger 51 when it is not adsorbed. When the signal input terminals 55a and 55b are not supplied with a signal, the slider 45 is urged downward to contact the lid 35. Stop in contact. As a result, the lead-out port 36b and the first communication port 37b are communicated with each other by the tunnel-shaped flow path formed by the slider 45 and the slide valves 41, 42 housed at both ends thereof, and the introduction port 34a and the second communication port 37a are communicated. The port 37a also communicates with the inside of the cylinder 33. Therefore, the refrigerant gas is the compressor 1 → the discharge pipe 34 → the first connecting pipe 39 → the outdoor coil 6 → the expansion valve 5
→ Indoor coil 4 → Second connection pipe 40 → Suction pipe 38 →
It becomes the cooling cycle circuit of the compressor 1.

FIG. 4 is a block diagram of a control circuit, and FIG. 5 is a flow chart showing the flow of control. In STEP 1, the signal S ₅ from the changeover switch 60 is input to the control circuit, and now,
Judge whether it is cooling operation or heating operation, and if it is cooling operation, STEP 2
In step 2-a, the signal S ₆ is output to the amplification circuit 62 for a certain period of time, and the signal S ₇ is output in the amplification circuit. No output to 62.

Then, the amplifier circuit 62 outputs the signal S ₈ and the signal input terminal 55
When a signal is input between a and 55c, a signal for a fixed time is input to the magnetizing coil 55d, and the plunger 51 is attracted to the fixed iron core 52 and abuts and stops. At the same time, the magnet 54 is magnetized,
Even after energization, the plunger 51 self-holds by its suction force. As a result, the lead-out port 36b and the second communication port 37c are communicated with each other by the tunnel-shaped flow path formed by the slider 45 and the slide valves 41 and 42 housed at both ends thereof, and the introduction port 34a and the first metering port are formed. 37b is also communicated through the inside of the cylinder 33. Therefore, the refrigerant gas is compressed from the compressor 1 → the discharge pipe 34 →
2nd connection pipe 40-> indoor coil 4-> expansion valve 5-> outdoor coil 6-> 1st connection pipe 39-> suction pipe 38-> compressor 1
It becomes the heating cycle circuit of and goes to STEP 4-a. Then S
In TEP4-a, the control circuit 61 inputs the signal _{S 1, S 2, S 3} , S 4 from the sensors 56, 57, the process proceeds to STEP5-a. Then ST
In EP5-a, each sensor 56,57,58,59 at the time of STEP4-a
Indoor temperature T ₁ (not shown), indoor heat exchanger temperature T
₂ (not shown), outdoor temperature T ₃ (not shown), and outdoor heat exchanger T ₄ (not shown) are expressed by the following equations (1), (2) T ₁ > T ₃ (1) and T ₂ When it is determined by the control circuit 61 that> T ₄ (2) is satisfied, it is determined that the heating operation is in progress and the process returns to STEP 1. Further, when the control circuit 61 determines that the following equations (3) and (4) T ₁ <T ₃ ... (3) and T ₂ <T ₄ ... (4) are satisfied, the changeover switch 60 is in the heating operation. Despite that, since it is the cooling operation, the process proceeds to STEP 6-a, and the control circuit 61 outputs the signal S ₆ ,
The signal S ₈ is output again through the amplifier circuit 62, the magnetizing coil 55d is magnetized, and the heating cycle is started. This operation is repeated below.

Next, when the changeover switch is cooling, in STEP 2-b,
The signal S ₇ is output to the amplifier circuit 62 for a certain period of time, and the signal S ₆ is not output. Then, the amplifier circuit 62 outputs the signal S ₉ and STPE3
At -b, a signal is input to the degaussing coil 55e for a certain period of time, the degaussing coil 55e is degaussed, the plunger 51 is urged downward in the figure by the action of the return spring 53, and the slider 45 contacts the lid 35 and stops.

Then, in STEP 4-b, the control circuit 61 controls the sensors 56, 57, 5
Input signals S ₁ ′, S ₂ ′, S ₃ ′, S ₄ ′ from 8,59
Go to 5-b. Then, in STEP5-b, STEP4-b temperature T ₁ of the respective sensors 56, 57, 58 at the time _{', T 2', T 3} ', T 4'
If the above equations (3) and (4) are satisfied, the control circuit
When 61 determines, it is determined that the cooling operation is in progress, and the process returns to STEP 1.

When it is determined that the control circuit 61 satisfies the equations (1) and (2), the changeover switch 60 is in the heating operation even though it is in the cooling operation, and therefore the process proceeds to STEP 6-b, and the control is performed. The circuit 61 outputs the signal S ₇ , degausses the degaussing coil 55e, and enters the cooling cycle.

As described above, according to the present embodiment, the slide pipe formed by the discharge pipe 34, the suction pipe 38, the slider 45 and the slide valves 41, 42 that switch the first and second connection pipes 39, 40 that constitute the refrigerant circuit. The fixed iron core 52 of the solenoid portion for driving the valve directly by the plunger 51 is divided, and a magnet capable of magnetizing and demagnetizing is provided between them, and the control circuit 61 includes the operation signal S ₅ from the changeover switch 60 and each sensor 56, 57,58,59 output signal S ₁ ,
S _2, S _3, whether there S ₄ input to the cooling operation state, it is determined whether there to the heating operation state, and outputs a signal S ₆ or S ₇ for a predetermined time, the signal 55a through the amplifier circuit 62, 55b It is configured to connect with. Therefore, when the coil 55 is energized, the plunger 51 is attracted to the fixed iron core 52 and at the same time the magnet 54 is magnetized to hold the plunger by itself, so that the energization is only required for a short time. In addition, restoration can be performed by energizing for a short time so as to give a magnetic field opposite to the attraction and demagnetizing the magnet 54 to release self-holding, and magnetizing and demagnetizing can be performed, so that the coil can be downsized, and Malfunction due to momentary power failure during energization control of coil 55 can be prevented, and easy control allows valve switching as in the conventional pilot mechanism or super large solenoid,
This is possible without using a positive temperature coefficient resistor.

Effects of the Invention As described above, the present invention includes a cylinder that forms a valve body,
A slide valve that slides in the cylinder in the axial direction to switch the conduction path, a plunger that connects one end to the slide valve and is movable in the axial direction, and opposes the other end of the plunger with the same axial center. Then, a fixed iron core provided via a return spring, a magnet which is inserted so as to divide the fixed iron core in the axial direction and which can be magnetized and demagnetized, and which is arranged outside the fixed iron core and the plunger. A magnetizing coil and a degaussing coil that have a shaft center substantially coincident with the shaft center and magnetize or demagnetize the magnet, and detect a room temperature, a sensor that detects the temperature of the indoor heat exchanger, and an outdoor temperature. A sensor for detecting, a sensor for detecting the temperature of the outdoor heat exchanger, a changeover switch for switching between cooling operation and heating operation, a control circuit for inputting signals from the respective sensors and changeover switch, and outputting the signal to the amplification circuit for a certain period of time. Control circuit Since it is configured to include an amplifier circuit for inputting these signals, amplifying them, and outputting signals to the magnetizing coil and the degaussing coil, it is possible to self-hold the plunger in the attracted state, so that the coil can be energized for a short time. Since it is possible to perform switching operation, it is a low cost and small pilot valveless type, but it consumes less power, and malfunctions due to momentary power outages during coil energization control are also based on the status of the switch and indoor / outdoor temperature. Judgment is made by controlling the energization to the coil, which eliminates malfunctions,
It is possible to provide a switching valve whose control is simple.

[Brief description of drawings]

1 is a sectional view showing a cooling state of a switching valve according to an embodiment of the present invention, FIG. 2 is a perspective perspective view of an essential part of FIG. 1, and FIG. 3 is a sectional view showing a heating state of FIG. FIG. 4 is a block diagram of a circuit for controlling a switching valve in one embodiment of the present invention, FIG. 5 is a flowchart showing a control flow, FIG. 6 is a sectional view showing a cooling state of a conventional switching valve, and FIG. The drawing is a cross-sectional view showing the heating state of FIG. 33 …… Cylinder, 41, 42, 45 …… Sliding valve, 51 …… Plunger, 52 …… Fixed iron core, 53 …… Return spring, 54 …… Magnet, 55
d …… Magnification coil, 55e …… Demagnetization coil, 55a, b …… Signal input terminal, 56 …… Indoor temperature detection sensor, 57 …… Indoor heat exchanger temperature detection sensor, 58 …… Outdoor temperature detection sensor, 59 …
… Outdoor heat exchanger temperature detection sensor, 60 …… Changeover switch,
61 ... Control circuit, 62 ... Amplifier circuit.

Front page continuation (72) Inventor Ichiro Sugioka 3-22 Takaidahondori, Higashi-Osaka, Osaka Prefecture Matsushita Refrigerating Machinery Co., Ltd. (56) Reference JP-A 63-285381 (JP, A) JP-A 64-3385 (JP, A)

Claims (1)

[Claims] 1. A cylinder that forms a valve body, a slide valve that slides in the cylinder in the axial direction to switch a conduction path, and a plunger that connects one end to the slide valve and is movable in the axial direction. A fixed iron core facing the other end of the plunger with the same axis center and provided via a return spring; and a magnet that is interposed so as to divide the fixed core in the axial direction and that can be magnetized and demagnetized. A magnetizing coil and a degaussing coil that are disposed outside the fixed iron core and the plunger and have a shaft center substantially matching the shaft center and magnetize or demagnetize the magnet, a sensor that detects an indoor temperature, and indoor heat exchange A sensor that detects the temperature of the unit, a sensor that detects the outdoor temperature, a sensor that detects the temperature of the outdoor unit heat exchanger, a changeover switch that switches between cooling operation and heating operation, and a signal from each of the sensors and the changeover switch. Enter and amplify Control circuit and receives a signal from the control circuit switching valve provided with an amplifier circuit which outputs a signal to the magnetizing coil and degaussing coil for outputting a predetermined time signals the road.