JPS6140870B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a control valve in which only a solenoid is disposed outside the valve body, and each element for switching fluid flow such as a fluid passage and a valve is housed within a common valve body. Regarding the control valve for reversible refrigeration equipment that can switch the refrigeration cycle from the cooling cycle to the heating cycle and vice versa, it is possible to eliminate fluid leaks and ensure the reliability of switching operation. The purpose of this invention is to reduce the size and labor-saving of the pilot valve solenoid in the control valve.

The most commonly used control valve (called a four-way switching valve) for switching fluid passages in this type of reversible refrigeration system is a pilot valve for operating a switching valve installed inside the control valve body. Since the control valve was attached outside the control valve body, a pilot pressure communication pipe was indispensable between the pilot valve and the valve body (see JP-A-48-45946 and JP-A-50-9141). ) There were disadvantages such as refrigerant leakage easily occurring in the connecting pipe, and the operating speed being slow due to the large resistance inside the pipe.

Moreover, because the switching valve installed inside the valve body and the piston devices on both sides were mechanically connected together, gaps tend to form on the sliding surface between the switching valve and the valve seat surface, resulting in high pressure. A short-circuit flow of refrigerant occurs between the chamber and the low-pressure chamber, deteriorating the fluid control function of the control valve, and it is difficult to ensure reliable switching when switching the refrigeration cycle using such a control valve. This caused the problem that stable refrigeration operation could not be performed because the refrigeration circuit did not enter into a normal cycle and remained in a transient state in the middle of switching.

In addition to the above-mentioned conventional technology,
As shown in the publication, a pilot valve with a plunger end as a valve body is installed inside the inner wall of the control valve body, and a pressure fluid introduction pipe is installed outside the control valve body. There were problems in that the force was large, the solenoid was large, and the operating speed of the control valve was slow.

The present invention has been made to provide a control valve for a reversible refrigeration system with a new configuration capable of eliminating such conventional defects, and particularly for controlling pressure switching operations and pressure conduction for switching control. The control valve can be processed inside the main body, and the electromagnetic force required for the pilot valve solenoid is reduced, the solenoid is made smaller, and the entire control valve is made smaller.In addition, the switching valve has a piston and a connecting rod so that it can be securely pressed against the valve seat. By using a control valve with a structure that is not fixed to the refrigeration circuit as a four-way switching valve, the switching operation is reliable, and the cooling cycle and heating cycle can be operated stably without refrigerant leakage. The present invention is characterized in that the solenoid of the pilot valve is made smaller and labor-saving.

Hereinafter, one embodiment of the present invention will be described in detail based on the accompanying drawings.

FIGS. 1 to 8 show the control valve of the present invention. Reference numeral 1 denotes a cylindrical valve body made of metal such as brass, which is composed of a large diameter cylindrical portion 1a and a small diameter cylindrical portion 1b.

This valve body 1 has a high pressure port 1c and a valve seat 9a facing each other on the circumferential wall of a large diameter cylindrical portion 1a.
d in the center, and two connection ports 1e and 1f are opened on both sides thereof, and these ports 1c, 1d, 1e, 1f are connected to refrigerant pipes 15, 1.
6, 18, and 17, respectively, to the discharge port of the compressor 2, the suction port, and the anti-expansion valve side pipe ends of the heat exchangers 3 and 4, respectively.

Reference numeral 9 denotes a bowl-shaped switching valve that is brought into airtight contact with the surface of the valve seat 9a, and there is a gap between the switching valve 9 and the surface of the valve seat 9a that includes the opening of the low pressure port 1d. Low-pressure chamber 9e shaped like a bowl
, and passages 9b, 9c, and 9d are provided inside the valve body, respectively.

The passage 9b is a through passage opened to the end face side of the small diameter cylindrical part 1b and the low pressure chamber 9e, and the passage 9c is a through passage opened to the end face side of the large diameter cylindrical part 1a and the top wall facing the high pressure port 1c. Further, the passages 9d are formed as through passages opened at appropriate locations in the low pressure chamber 9e and the top wall, respectively.

The low pressure chamber 9e is connected to the low pressure port 1d and the connecting ports 1e, 1 by sliding the switching valve 9.
f are made independent and disconnected from each other (see Figure 4), and low pressure port 1d is connected to both connection ports 1 and 1d.
It is possible to selectively communicate with either e or 1f (see FIGS. 2 and 6).

The switching valve 9 is made of heat-resistant synthetic resin, e.g.
It is made of nylon and is mechanically engaged with the large and small piston devices 13 and 14 arranged oppositely on both sides via the connecting member 10, and by the movement of both piston devices 13 and 14. It is adapted to slide on the surface of the valve seat 9a.

The large and small piston devices 13 and 14 are the large diameter cylindrical portion 1
a. The small-diameter cylindrical portion 1b has pistons 13 and 14 installed so as to be able to slide in an airtight manner, and the pressure-receiving areas of both pistons 13 and 14 are made different in size and formed on the backs thereof. When the inside of the chamber _R1 is a high pressure region and the inside of the chamber _R2 is a low pressure region, as shown in FIGS. 2 and 8, the small diameter cylindrical portion 1b moves in the direction toward the end surface (to the left in the figure). , and when both the working chambers R ₁ and R ₂ are in the same low pressure region, the large diameter cylindrical portion 1a is caused by the high pressure force existing in the space around the switching valve 9 as shown in FIGS. 4 and 6. They move as one in the direction toward the end face (toward the right in the figure).

Therefore, the connecting member 10 is connected to each piston 1.
3 and 14, but not tightly engaged with the switching valve 9, for example, by engaging with the outer wall of the switching valve 9 in a fitting relationship. The switching valve 9 is mounted in a loose relationship such that it can freely move in a direction perpendicular to the surface of the valve seat 9a.

Then, elastic devices 19, 19 are interposed at this loosely engaged portion to press the switching valve 9 against the surface of the valve seat 9a with an appropriate elastic force.

The action chambers R ₁ and R ₂ are connected to the passages 9c and 9d through communication pipes 11 and 12, respectively, through which the pistons 13 and 14 are inserted.
Reference numerals 1 and 12 are flexible tubes partially or entirely made of fluororesin or the like, and have a rigid connection between the pistons 13 and 14 and the switching valve 9. Please do not let them hold the ammunition 1.
9 and 19 facilitate airtight sliding of the switching valve 9.

It goes without saying that in the control valve having the above configuration, the space 1g surrounding the switching valve 9 in the valve body 1 is always formed in a high pressure atmosphere. The pilot valve 7 is slidably attached to the sliding surface where the openings of the passages 9c and 9d exist in an airtight manner.

The pilot valve 7 is formed of a plate with a square-shaped plane, and is pivotally supported by a hollow cylindrical pin 8 inserted into the passage 9d, and the sliding contact is rotatable about the pin 8 as a fulcrum. Attached to the surface.

A passage 7a that communicates with the sliding surface by crossing the pilot valve 7 from a passage 9d opening in the sliding surface, and a passage 7b that communicates the sliding surface and the upper part of the pilot valve 7, respectively. ing. Note that the passage 7b may be a notch that opens into the high pressure region 1g instead of a hole.

The pilot valve 7 selectively switches the passage 9c to the passage 7a or the passage 7b according to the movement of the locking piece 6 operated by a solenoid, which will be described later, and when it is switched to the passage 7b, it communicates with the high pressure port 1c,
When the passage is switched to the passage 7a, it communicates with the low pressure chamber 9e via the passage 9d.

A solenoid 5 is attached to the outside of the valve body 1 with its operating axis parallel to the plate surface of the pilot valve 7 and substantially orthogonal to the locking piece 6.

The above-mentioned solenoid is a spring offset type that houses a spring 5c inside, and has a plunger 5b.
is fixed to the side wall of the valve body 1 in an airtight slidable manner, and the plunger 5b is fixed to the side wall of the valve body 1 in an airtight manner.
The pilot valve 7 is connected to the locking piece 6 through the
Operate the switch.

The locking piece 6 is connected to the tie rod 5a through a long hole 20, and is formed to be movable in a direction perpendicular to the axial direction of the solenoid 5.

The operating mode of the control valve configured as described above will be explained next.

When the refrigeration system is operated for heating, as shown in FIGS. 1 and 2, when the solenoid 5 is de-energized, the plunger 5b is pushed out by the spring 5c (moves upward in FIG. 1), and is therefore not engaged. The stop piece 6 is pushed forward.

As a result, the passage 7b communicates with the passage 9c and through the communication pipe 11 to the working chamber R1 on the large chamber side, so that the inside of the working chamber _R1 communicates with the high pressure region within the valve body ₁ .

On the other hand, the action chamber _R2 on the small chamber side is constantly in communication with the low pressure chamber 9e via the communication pipe 12 and the passage 9b.

Therefore, the large action chamber R ₁ becomes a high pressure region and the small action chamber R ₂ becomes a low pressure region, and due to the differential pressure between both chambers R ₁ and R ₂ , the switching valve 9 slides toward the small diameter cylindrical portion 1b ( 2), the connection port 1e is communicated with the low pressure port 1d, and the connection port 1f is communicated with the high pressure region within the valve body 1'.

Thus, the flow of refrigerant is as follows: compressor 2 discharge port → discharge pipe 15 → high pressure port 1c → valve body 1 internal space 1
g → Connection port 1f → Refrigerant pipe 17 → Heat exchanger (indoor side) 4 → Expansion valve → Heat exchanger 3 → Refrigerant pipe 1
8 → Connection port 1e → Low pressure chamber 9e → Low pressure port 1
d → Follow the route of compressor 2 inlet.

When switching from heating operation to cooling operation, first, during the switching, as shown in FIGS. 3 and 4, by energizing the solenoid 5, the plunger 5b is attracted and the tip of the locking piece 6 is moved toward the front. Since the pilot valve 7 is pulled downward (downward in FIG. 3), the pilot valve 7 also slides.

Thus, the passage 7b is disconnected from the large action chamber _R1 , while the passage 9c communicates with the low pressure port 1d, that is, the low pressure region, via the passage 7a and the low pressure chamber 9e.

Therefore, the high pressure refrigerant in the large working chamber _R1 escapes to the low pressure side, and naturally the large working chamber _R1 becomes a low pressure region.

In this state, the pressure difference between the front and rear surfaces of the piston of the small diameter piston device 14 remains the same as before, but the pressure difference between the front and rear surfaces of the piston of the large diameter piston device 13 changes, due to the difference in the pressure receiving area of both pistons. Due to the action of the high-pressure refrigerant around the switching valve 9, both piston devices 13, 14 and the switching valve 9 begin to move toward the side that compresses the large action chamber _R1 .

Although this movement further progresses, even if the solenoid 5 is fully suctioned, the locking piece 6 has the elongated hole 20 as described above, so it will not move in the direction perpendicular to the solenoid axis. Because it is possible,
There is no hindrance to the further movement of the switching valve 9 toward the large action chamber _R1 side, and the large piston device 13 comes into contact with the end face of the large diameter cylindrical portion 1a, and is agitated by this movement. Then, the switching valve 9 also slides smoothly into the state shown in FIGS. 5 and 6.

The switch to cooling operation is then completed, but the flow of refrigerant at this time is from the compressor 2 discharge port to the discharge pipe 1.
5 → High pressure port 1c → Valve body 1 internal space 1g → Connection port 1e → Refrigerant pipe 18 → Heat exchanger 3 → Expansion valve → Heat exchanger 4 → Refrigerant pipe 17 → Connection port 1f
→ Low pressure chamber 9e → Low pressure port 1d → Compressor 2 inlet.

Furthermore, to explain the process during the switching from cooling operation to heating operation, in FIGS. 7 and 8, when the solenoid 5 is de-energized, the plunger 5b and tie rod 5a are moved forward by the restoring force of the spring 5c. , and the locking piece 6 also rotates forward.

Therefore, the passage 7a and the passage 9c are disconnected from each other, and the passage 9c then opens to the high pressure side via the passage 7b.

As a result, high-pressure refrigerant flows into the large working chamber _R1 , and the pressure difference between the inside and outside of the large diameter piston device 13 disappears, and due to the pressure difference between the inside and outside of the small diameter piston device 14, the working pressure increases. - The small diameter piston devices 13 and 14 move toward the small diameter cylindrical portion 1b, and the switching valve 9 also moves toward the small diameter cylindrical portion 1b.

Note that even if the locking piece 6 and the tie rod 5a begin to move further toward the small-diameter cylindrical portion 1b from the neutral position shown in the figure, there is play in the engagement portion between the locking piece 6 and the tie rod 5a that does not hinder the movement, so that smooth movement is achieved. This is the same as the case described above.

Note that this control valve is assembled by fixing the valve seat 9a to the large diameter cylindrical portion 1a of the valve body 1, and fixing the valve seat 9a to the small diameter cylindrical portion 1b.
After welding, the switching valve 9 incorporating both piston devices 13 and 14 is inserted through the open opening of the large diameter cylindrical portion 1a, and the end plate is welded to the opening of the large diameter cylindrical portion 1a to assemble. It is something to do.

As clarified by the above explanation, the present invention is a reversible refrigeration system using a control valve having a structure in which only the solenoid 5 is provided outside the valve body 1 and all other members are provided in the hollow part of the valve body. Since it is used as a road switching valve, refrigerant piping is connected only to the four ports 1c to 1f, unlike conventional control valves in which piping is provided externally to connect the pilot valve and the control valve body. Since only a few steps are required, the brazing process is easy, and the structure can be made simple and compact.

In addition, compared to conventional control valves in which a passage connecting the pilot valve and the control valve body is bored in the inner wall of the valve body, it is easier to process, and the passage is shortened and shortened to increase the switching response speed of the control valve. can do.

In addition, since a pilot valve for switching the control valve is provided in the control valve body 1 and switching is performed within the valve body 1, it is not necessary to provide a complicated valve such as a pilot three-way solenoid valve in the refrigeration circuit. In addition to reducing costs, the number of connection points in the flow path for refrigerant having a high pressure of about 20 kg/cm ² or more is greatly reduced, which has the advantage of eliminating the risk of refrigerant leakage. Reliability to the device is doubled.

In addition, in the case of switching the pilot valve 7, the locking piece 6 attached to the pilot valve 7 acts as a screw, and the pin 8
Since it rotates using the locking piece 6 as a fulcrum, the attraction force and electromagnetic force of the solenoid that actuates the plunger 5b via the tie rod 5a connected to the locking piece 6 are small in inverse proportion to the length of the locking piece 6, which serves as a screw. Compared to conventional control valves in which the plunger end of the pilot valve is the valve body, the solenoid can be made much smaller, the entire control valve can be made smaller, and costs can be reduced.

Furthermore, the control valves are provided with piston devices 13, 14 on both sides.
Since the pressure-receiving areas of the valves are different, the switching valve 9 can be slid more precisely depending on the relationship with the working pressure, compared to a structure with the same working pressure area (for example, see Japanese Patent Application Laid-Open No. 48-45946). Furthermore, the pilot valve 7 connected to the solenoid can have a simple structure, and the switching of the refrigeration circuit can be performed reliably and stably.

Moreover, the switching valve 9 is not tightly engaged with the piston devices 13 and 14 on both sides, and the valve seat 9a is
It has a degree of freedom in the direction perpendicular to the plane, and the bullet 1
9 with appropriate pressure, the movement is smooth, the airtightness is extremely effective, and there is no refrigerant leakage inside the valve, which has a large difference between high and low pressures (more than 15 kg/cm ² ).

Furthermore, the connecting pipes 11 and 12 only need to be long enough to communicate between the switching valve 9 and the piston devices 13 and 14, which are located close to each other. The control valve can be operated smoothly, shortening the valve operation time and enabling quick switching operation.In this way, the reliable switching operation of the control valve and the reduction of the number of piping connections around the control valve reduce the amount of refrigerant. As a result of preventing leakage, stable refrigeration operation is achieved, and the reliability of the refrigeration system is doubled, and the present invention has various excellent effects.

[Brief explanation of the drawing]

Figures 1, 3, 5 and 7 show the control valve of the present invention during heating and during switching from heating to cooling;
2 and 4 are cross-sectional plan views functionally showing each operating state during cooling and when switching from cooling to heating.
6 and 8 are vertical cross-sectional front views of the control valves corresponding to the above-mentioned figures. 1...Valve body, 1c...High pressure port, 1d...
Low pressure port, 1e, 1f... Connection port, 5...
Solenoid, 5a... tie rod, 5b... plunger, 6... locking piece, 7... pilot valve, 7
a, 7b...passage, 8...pin, 9...switching valve, 9a...valve seat, 9b, 9c, 9d...
...Passway, 9e...Low pressure chamber, 10...Connection member, 1
1, 12... Communication pipe, 13, 14... Piston device, R ₁ , R ₂ ... Action chamber.

Claims (1)

[Claims] 1 A high pressure port 1c and a valve seat 9a are provided oppositely on the wall of the valve body 1, and the valve seat 9
A has a low pressure port 1d and two connection ports 1e and 1f opened on both sides of the low pressure port 1d, respectively, to connect the valve body 1.
Inside, there is a switching valve 9 that is in contact with the surface of the valve seat 9a, and two piston devices 13 that are arranged oppositely on both sides of the switching valve 9 and that are respectively engaged with the switching valve 9 via connecting members 10. , 14 respectively, and the two piston devices 13 and 14 are housed in the former 1.
The pressure receiving area of the piston device 1 is formed to be larger than that of the latter 14, and
3, 14 and both side walls of the valve body 1, there is an action chamber R.
1 and R2 respectively, and the switching valve 9
A bowl-shaped low pressure chamber 9e is formed between the valve seat 9a and the surface of the valve seat 9a including the low pressure port 1d opening.
The low pressure A passage 9b that communicates the chamber 9e with the action chamber R2, the low pressure chamber 9e and the switching valve 9.
A sliding surface portion is formed on the top wall portion of the switching valve 9 where the passages 9c and 9d open, and a plate-shaped pilot valve 7 is provided on the sliding surface portion. , is provided so as to be rotatable and airtightly slidable about the pin 8 inserted in the passage 9d, and inside the pilot valve 7,
A passage 7a communicating with the sliding surface by crossing the pilot valve 7 from an opening of the passage 9d in the sliding surface, and a passage 7b communicating between the sliding surface and the upper part of the pilot valve 7 are provided, respectively. Further, a locking piece 6 is attached to the pilot valve 7 to selectively communicate the passage 9c with the high pressure port 1c via the passage 7b or with the low pressure chamber 9e via the passage 7a. A control valve for a reversible refrigeration system, characterized in that a locking piece 6 is rotatably connected to a plunger 5b of a solenoid 5 via a tie rod 5a.