JPS5812971A - Air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating and cooling system using an electric type (pulse motor type) expansion valve.

As an expansion valve inserted into the refrigerant circuit of an air conditioning system,
The refrigerant flow rate can be quickly increased or decreased in response to load fluctuations, and adjustments can be made accurately, and the refrigerant flow rate can be increased to the maximum at startup or shutdown to perform rapid cooling and heating, or to increase or decrease the refrigerant flow rate at the input and output ports of the compressor. What is desired is a device that can quickly equalize the pressure of

However, conventional expansion valves convert the temperature at the outlet of the evaporator into pressure using a heat-sensitive cylinder, and use this pressure to deform a diaphragm such as a bellows or diaphragm to move the valve stem up and down to control the flow rate of refrigerant. However, with this method, the response speed of the thermosensor is slow because it converts the temperature at the evaporator outlet into pressure, and the expansion valve etc. do not have integral action, so the degree of superheat changes depending on the refrigeration cycle load. Furthermore, since the amount of movement of the valve stem is small and the fluid pressure caused by the refrigerant is high, the operating pressure must also be increased.

In recent years, in order to correct the above-mentioned drawbacks, a proportional expansion valve has been developed that converts the temperature at the evaporator inlet and outlet into an electrical signal, and uses that electrical signal to move the iron core inserted in the electromagnetic coil up and down. However, although this expansion valve has improved responsiveness, it has the drawback that valve adjustment, that is, fine adjustment of the valve opening, is extremely difficult.

The present invention was made in view of the above-mentioned problem, and its purpose is to quickly increase or decrease the refrigerant flow rate in response to load fluctuations, and to easily make fine adjustments to achieve optimal cooling and heating. We are in the process of providing equipment.

Another object of the present invention is that by quickly adjusting the maximum and minimum openings of the valve, rapid heating and cooling can be performed, and the input and output pressures of the compressor can be quickly equalized when the compressor is stopped. An object of the present invention is to provide a heating and cooling device that can shorten restart time.

Furthermore, another object of the present invention is that the coil part is disposed outside the casing to solve the problem of electrical insulation and heat generation, and there is no problem of sealing in the rotating part, so leakage can be prevented. In addition, we provide air-conditioning and heating equipment that is compact, easy to manufacture, and reduces costs.

An embodiment of the present invention will be described below with reference to the refrigerant circuit shown in FIG.

In the figure, 11 is a compressor, and an electromagnetic four-way valve 1
2, the heat source side heat exchanger 13, the electrically operated expansion valve 14 capable of forward and reverse flow, and the usage side heat exchanger 15 are connected in an annular manner,
It has a refrigeration cycle i that can be cooled and heated. Reference numeral 16 denotes a liquid receiver provided in the suction pipe section to the compressor 11. That is, in this refrigeration cycle, during cooling operation, the compressor is 9. The refrigerant discharged from the pipe 11 is sequentially passed through the electromagnetic square piece 12, the heat source side heat exchanger (operates as a compressor) 13, the electrically operated expansion valve 14 capable of forward and reverse flow, and the user side heat exchanger (operates as an evaporator). 15, an electromagnetic four-way valve 12, and a liquid receiver 16, and is sucked into the compressor 11.

During heating operation, the refrigerant discharged from the compressor 11 is sequentially transferred to the electromagnetic four-way valve 12, the user-side heat exchanger (operates as a condenser) 15, the electric expansion valve 14, and the heat source-side heat exchanger (evaporator). ) 13, solenoid four-way valve 12,
It passes through the liquid receiver 16 and is sucked into the compressor 11. 17.1B is a temperature-sensitive resistance element that detects the temperature of the heat exchanger on the user side, the refrigerant outlet temperature and This is a temperature-sensitive resistance element that detects

Reference numeral 21 denotes an electric control circuit, which controls the opening degree of the electric expansion valve 14 by signals from both temperature-sensitive resistance elements 17 and 18 during cooling operation, and by signals from both temperature-sensitive resistance elements 19 and 20 during heating operation. It controls the moreover,
Reference numeral 22 denotes a start-up control electric circuit, in which the electric control circuit 21 is not energized at the start of operation, and the electric expansion valve 14 is not energized.
After applying a large number of pulses and starting the operation and a predetermined period of time has elapsed, energization is switched from the electric expansion valve 14 to the electric control circuit 21.

The structure of the type-operated expansion valve 14, that is, the pulse motor type expansion valve, will be explained below with reference to FIG. 2 and subsequent figures.

Reference numeral 1 denotes a main body in which a cylinder part 1a and a casing part 1b are integrally molded, and a refrigerant inlet pipe 2 is fixed to the lower end of the cylinder part 1a, and a refrigerant outlet pipe 3 is fixed to the side surface.

The valve seat 1a+ is located at the portion where the inflow pipe 2 is fixed.
is formed. 4 is a valve stem screwed into a screw hole 1a2 formed in the cylinder part 1a, and a tip needle valve 4
a faces into the valve seat 1a+. A square hole 4b is bored in the upper end of this valve stem 4. Reference numeral 5 denotes a reduction gear formed in the casing part lb between the partition plate 1b1 and a lid 6 to be described later, and its output shaft 5a is connected to the partition plate 1b+.
The end prismatic portion 5a is inserted into the rectangular hole 4b of the valve stem 4 so as to be vertically movable. Therefore, when the output shaft 5a is rotated, the valve stem 4 moves up and down while rotating. Reference numeral 6 denotes a lid made of a non-magnetic material that is screwed onto the upper end opening of the casing 1b and sealed, and a thin cylindrical portion 6a extends upward from the center, and a bearing portion 6b is integrally formed at the upper end. . Further, a bearing 6C is fitted in the center of the lid 6.

When the lid 6 is screwed and tightened onto the casing 1b, the lower sloped portion 6d comes into contact with the stepped portion lb2 of the casing 1b, so it is sealed at this portion, but if you want to improve the degree of sealing, the opening 6e This can be done by filling the area with a sealing material (for example, solder or adhesive). A rotor 7 is a permanent magnet whose outer circumferential surface is alternately magnetized with north and south poles, and is rotatably housed in the cylindrical portion 6a, and the rotating shaft 7a is connected to the bearing portion 6b and the bearing 6C. It is pivoted on. The lower end of the rotating shaft 7a protrudes from the bearing 6C, and a gear 7b that meshes with the reduction gear 5 is fixed thereto. Reference numeral 8 denotes a stator consisting of a two-phase coil, which is fitted onto the outer periphery of the cylindrical portion 6a. And the lead wire 8
A is connected to a controller that detects a temperature difference between the evaporator inlet and outlet (not shown) and sends out a pulse signal in proportion to the change in temperature difference. Therefore, when the temperature difference increases, a positive pulse is generated, so a positive pulse is applied to the stator 8, and the rotor 7 is rotated in the direction in which the pulp opens. Reference numeral 9 denotes a fixed hand holding member screwed and fixed to the above-mentioned bearing portion 6b, and by tightening this, the stator 8 is pressed against the lid body 6 side, and the stator 8 is fixed. ,,1. ,
, Next, the operation will be explained based on the above configuration.

Now, when a positive or negative pulse is applied from the controller to the coil, which is the stator 8, the coil is excited to the north or south pole, and the permanent magnet, which is the rotor 7, rotates at a rotation angle proportional to the number of pulses. . As a result, the rotating shaft 7a is rotated,
It is decelerated by the reduction gear 5 and transmitted to the output shaft 5a. When the output shaft 5a is rotated, the valve stem 4 is rotated, since its square column part 5a is inserted into the square hole 4b. The needle 4a opens and closes the valve seat 1a+.

By the way, in the above, the fluid pressure of the refrigerant is applied to the needle 4a, but here the fluid also flows into the upper space of the valve stem 4 via the screw hole 1a2 (if a differential pressure occurs in the upper and lower spaces, the two Through hole 4C as shown by the dotted chain line
), so no external pressure is applied to the valve stem 4,
Therefore, since the driving torque only needs to be small, the motor can be made smaller. Furthermore, by housing up to the rotor 7 in the sealed lid 6, there is no need to seal the rotating part at all, and the reliability of the seal can be improved.

In addition, the stator 8 through which the current flows is removed from the casing.
:1), there is no problem with electrical insulation, and there is no need to worry about the problem of self-heating of the coil or heat generation due to the temperature of the passing fluid (in addition, the stator 8
Since it is removable, it can easily be disconnected or replaced with another coil.

FIGS. 2 and 3 show examples of other valve parts, and in the valve stem 4 in FIG. 1, there is a possibility that the needle 4a may bite into the valve seat 1a+ due to the rotational force of the output shaft 5a. This embodiment has been improved in this respect.

That is, in FIG. 2, a cavity 4d is formed at the lower end of the valve stem 4, and the needle 4a is inserted into the cavity 4d so as not to come out, and is pressed by a spring 10. As a result, the needle 4a is pressed against the valve seat 1al by the spring force of the spring 10, and after the needle 4a comes into contact with the valve seat 1a+, only the valve stem 4 descends. Therefore, the needle 4a will not bite into the valve seat 1a+.

Further, in FIG. 3, an inflow pipe 2 and an outflow pipe 3 are fixed to the side surface of the cylinder 1a, and are divided into an upper chamber 1a3 and a lower chamber 1a4 by a valve seat 1a1. The chamber 1a4 and the outflow pipe 3 are communicated with each other, and the lower chamber t
The needle 4a is inserted into a4 toward the valve seat 1a+ side, and the spring 10 constantly presses the needle 4a toward the valve seat 1a+ side. Then, the lower end of the valve stem 4 is made thinner to form a protruding rod 4e, which is brought into contact with the tip of the needle 4a. As a result, when the valve rod 4 descends, the needle 4a descends against the spring force of the spring 10 to open the valve. Further, when the valve stem 4 rises, the needle 4a rises due to the force of the spring 10 and comes into contact with the valve seat 1a+. Therefore, the needle 4a will not bite into the valve seat 1a1.

Note that the motor is not limited to a pulse motor.
Other motors such as synchronous motors can also be used.

Furthermore, the rotor 7 is not a permanent magnet (or alternatively, a rotating iron piece (in this case, a permanent magnet is fixed inside and positioned between the permanent magnet and the coil) can also be used.

Furthermore, when a pulse motor is used, the rotation angle can be controlled by the number of pulses, so by increasing the number of poles of the motor, the rotation angle for one pulse can be reduced, so the reduction gear 5 is not necessarily required in this case. .

In the above configuration, the operation will be explained next.

At the start of energization, the rise control electric circuit 22 does not energize the electric control circuit 21, and a large number of pulse signals are applied to the coil 8 in the electric expansion valve 14.
Cooling or heating operation is performed in a state where the opening of the valve 4', that is, the opening between the valve seat 1a1 and the lower end of the valve stem 4 rapidly increases. Therefore, rapid cooling or heating is performed. After a desired period of time has elapsed and the cooling or heating operation reaches a steady state, the start-up control circuit 22 switches the energization from the electric expansion valve 14 to the electric control circuit 21 . When the electric control circuit 21 is energized, a voltage difference due to the temperature difference is detected from the temperature-sensitive resistance elements 17 and 18 during cooling operation, and from the temperature-sensitive resistance elements 19 and 20 during heating operation, and the voltage difference is detected. Accordingly, a pulse signal is applied to the coil 8 in the electric expansion valve 14 to control it.

That is, when the voltage difference is large, many pulses are generated to widen the electric expansion valve 14, and when the voltage difference is small, the number of pulses is small to reduce the degree of opening.

Furthermore, when heating and cooling is stopped, the electric expansion valve 14 is opened wide in response to a pulse signal from the start-up control circuit 22, and the pressure difference between both ends of the compressor 11 is quickly equalized. This can shorten the waiting time until restart.

As described above, the present invention detects the difference between the temperature of the evaporator and the refrigerant outlet temperature during cooling or heating operation, and controls the number of pulses to the coil of the electric expansion valve, thereby adjusting the heating and cooling capacity according to the load. The valve opening can be quickly maximized when starting and stopping cooling/heating, allowing rapid cooling/heating, and when the compressor is stopped, the pressure at the inlet and outlet of the compressor can be quickly equalized, shortening the time it takes to restart. If possible, store the motor rotor near the valve stem.
! Since the stator is housed in a casing that can be rotated, and the stator is placed around the outer periphery of this casing, there is no need for a seal at the rotating part, which improves the reliability of the seal.The stator, which generates heat, is outside the casing, so consideration must be given to heat dissipation. Since there is no need to remove the stator coil, and the stator coil can be easily removed, it is possible to freely change the coil due to disconnection of the coil, increase or decrease the driving force, etc., and prevent fluid flow to the valve stem. Since no pressure is applied, a small 6-inch motor can be used and the overall size can be reduced, and assembly is easy and production costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram of a heating and cooling system according to an embodiment of the present invention, and FIGS. 2 to 4 are cross-sectional views showing examples of electric expansion valves used in the heating and cooling system. DESCRIPTION OF SYMBOLS 1...Main body, 4...Valve stem, 6a...Cylindrical part, 7...
... Rotor, 8... Fill, 13, 15... Heat exchanger.

Claims (1)

[Claims] A pulse motor type expansion valve is used in a refrigerant circuit, in which a thin cylindrical portion is formed in a sealed state in a main body having a valve stem that screws together and rotates, and a rotor is placed inside the cylindrical portion, and a stator is placed on the outer periphery of the cylinder. The stator is connected to an electric control circuit that converts an electric signal from a temperature sensor installed in the refrigerant circuit into a pulse signal, and the pulse signal rotates the rotor to move the valve stem up and down. A heating and cooling device characterized in that the air conditioner is configured to move the refrigerant and control the flow rate of the refrigerant.