JPH0338601Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is a type of expansion valve used to control the amount of refrigerant supplied to the evaporator of a refrigeration system, and in which the expansion valve main body can be detachably attached. Regarding valves.

(Prior art and its problems) Conventionally, as an expansion valve whose main body is detachable, for example, Utility Model Application No. 60-41772
No. 3 is publicly known. However, in this conventional expansion valve, as shown in FIG. Although the outer diameter is smaller than the outer diameter, since the inner diameter of the housing 2 is uniform except for the vicinity of the end on the side of the insertion port 3, when the expansion valve main body 4 is installed, the O-ring 5 is 2 When sliding through the edge portion 2a of the inner circumferential surface, the edge portion 2
This causes a problem in that the sealing performance between the inner circumferential surface of the housing 2 and the outer circumferential surface of the expansion valve body 4 becomes poor.

(Purpose of the invention) The present invention was made to solve the problems of the prior art described above, and in an expansion valve whose main body is detachable, the inner peripheral surface of the housing and the main body of the expansion valve are It is an object of the present invention to provide an expansion valve that can reliably improve sealing performance with an outer circumferential surface with a relatively simple configuration.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a hollow cylindrical shape with one end open and the other end closed, the opening serving as an insertion port, and a condenser. a first connection port that communicates with the inlet of the evaporator on the side of the insertion port from the first connection port, a second connection port that communicates with the inlet of the evaporator on the side opposite to the insertion port from the first connection port; a housing having, on its peripheral wall, a third connection port communicating with the compressor at a position facing the third connection port, and a fourth connection port communicating with the compressor at a position opposite to the third connection port; an expansion valve main body having a first through hole communicating with the connection port and a second through hole communicating with the second connection port; a side of the expansion valve main body opposite to the insertion port from the first communication hole; 1
O-rings are fitted into annular grooves provided on the outer circumferential surface between the through hole and the second through hole, and hold the inner circumferential surface of the housing and the outer circumferential surface of the expansion valve body airtight. In the expansion valve, the inner circumferential surface of the portion of the housing where the first connection port and the second connection port open, and the portion closer to the insertion port than the opening of the second connection port, each have an inner diameter of A large diameter portion larger than the outer diameter of the O-ring, and an inner circumferential surface of the housing from the large diameter portion to a non-large diameter portion,
The O-ring is shaped to allow the O-ring to pass through without being caught when the expansion valve main body is inserted into the housing.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a block diagram of a refrigeration system incorporating the expansion valve of the present invention. In the figure, 1 indicates the entire expansion valve of the present invention, and the expansion valve 1 is installed in a housing 2 at one end (the lower end in the figure ) from the insertion port 3 provided in the expansion valve body 4.
₁ and 5 ₂ and airtightly closes the insertion port 3 with a closing member 6, thereby fixing the expansion valve main body 4 within the housing 2. The housing 2 has a hollow cylindrical shape with one end (lower end in the figure) open and the other end (upper end in the figure) closed, and the inner hole thereof serves as the expansion valve body insertion chamber 7. . A first connection port 8 is provided at a substantially intermediate portion in the axial direction of one side peripheral wall of the housing 2 so as to pass through the housing 2 in the radial direction. A second connection port 9 is provided at one end (on the insertion port 3 side) of the other circumferential wall of the housing 2 from an approximately intermediate portion in the axial direction, passing through the housing 2 in the radial direction. The other end side of the other peripheral wall of the housing 2 (side opposite to the insertion port 3)
A third connection port 10 is provided to penetrate in the radial direction. A fourth connection port 1 is provided at the other end of one peripheral wall of the housing 2, facing the third connection port 10.
1 is provided to penetrate in the radial direction.

The inner peripheral surface of the housing 2 is connected to the first connection port 8.
The other end side (opposite the insertion port 3 side) and the first connection port 8
and the second connection port 9 is the small diameter portion 2a, and one end ( (on the insertion port 3 side) are respectively located at the large diameter portion 2b, and the O-rings 5 ₁ and 5 ₂ provided at positions facing the small diameter portion 2a have an outer diameter larger than the inner diameter of the small diameter portion 2a when uncompressed. The inner diameter of the large diameter portion 2b is slightly larger than the outer diameter of the O-rings 5 ₁ and 5 ₂ when they are not compressed. The small diameter portion 2a and the large diameter portion 2 of the housing 2
The inner circumferential surface between the inner circumferential surface and b is a tapered portion 2c.

The expansion valve main body 4 has a casing 12 that is radially fitted into the expansion valve main body insertion chamber 7 of the housing 2, and the outer peripheral surface of the casing 12 is connected to one end of the second connection port 9 (lower end in the figure). ), one end side (lower end side in the figure) has a larger diameter than the other end side (upper end side in the figure) via the first step portion 12a located at a position that matches the first step 12a. In the casing 12, a second step portion 12b located further on one end side (lower end side in the figure) than the first step portion 12a abuts against a step portion 3a in the insertion opening 3 of the housing 2, and the other end portion (upper end side in the figure) ) and the inner end of the insertion chamber 7 of the housing 2, there is a gap 7a serving as a refrigerant passage chamber, and the third and fourth connection ports 10 and 11 are opened into the refrigerant passage chamber 7a, respectively. . The casing 12
has a hollow cylindrical shape with both end surfaces open, and its inner circumferential surface extends from one end side (lower end in the figure) through a stepped portion 13 that is located approximately in the middle in the axial direction and is a surface orthogonal to the axis. side) has a larger diameter than the other end (upper end side in the figure). A small diameter portion inside the casing 12 serves as an operating rod fitting chamber 14, and an operating rod 15 is slidably fitted into the operating rod fitting chamber 14. The operating rod 15 has a step portion 16 located approximately in the middle in the axial direction, so that one end side (lower end side in the figure) has a larger diameter than the other end side (upper end side in the figure), and the outer peripheral surface of the large diameter portion 15a is It is diametrically fitted to the inner circumferential surface of the operating rod fitting chamber 14 so as to be slidable. A regulating valve body 17 is attached to one end of the operating rod 15 so as to be able to operate integrally therewith.
The regulating valve body 17 is located on the inner circumferential side of the stepped portion 13 and connects with the operating rod fitting chamber 14 .
It has a truncated conical shape with a tapered seat portion 20 that approaches and separates from an acute-angled seat portion 19 provided at the periphery of the cylindrical member 8 . In the valve closed state in which the tapered seat portion 20 of the regulating valve body 17 contacts the acute-angled seat portion 19 of the passage 18, the step portion 16 of the operating rod 15 in the operating rod fitting chamber 14 and the adjusting valve body 17 are connected to each other. A high pressure chamber 21 is defined between the tapered sheet portion 20 side (upper end side in the figure) end. The adjusting valve body 17 is urged toward the valve closing side (upper side in the figure) by a spring 22, and the spring 22 is screwed into the inner circumferential surface of the adjusting valve body 17 and one end side of the large diameter portion of the casing 12. The spring receiving member 23 is interposed between the spring receiving member 23 and the spring receiving member 23 . A low pressure chamber 24 is defined between the step portion 13 and the spring receiving member 23 within the large diameter portion of the casing 12 .
A first through hole 25 and a second through hole 26, which open into the high pressure chamber 21 and the low pressure chamber 24, respectively, are provided through the peripheral wall of the casing 12 in the radial direction. The first through hole 25 and the second through hole 26 are provided on both sides of the casing 12, with the first through hole 25 on one side connecting to the first connection port 8 and the second through hole 26 on the other side connecting to the first connecting port 8. 2 connection ports 9, respectively.

A first through hole 2 is provided on the outer peripheral surface of the casing 12.
Annular grooves 27 ₁ and 27 ₂ are provided on the other end side of 5 and between the first through hole ₂₅ and the second through hole ₂₆ , respectively. 5 ₁ and 5 ₂ are fitted respectively, and these O-rings 5
₁ and 5 ₂ , a high pressure side and a low pressure side between the inner peripheral surface of the insertion chamber 7 of the housing 2 and the outer peripheral surface of the casing 12 are airtightly divided.

A diaphragm (pressure responsive member) 28 is provided within the recess provided at the other end of the casing 12. The outer periphery of the diaphragm 28 is held between the outer periphery of the inner bottom wall of the recess at the other end of the casing 12 and the outer periphery of the plate 29.
9 and the diaphragm 28 has a gap 29a. The center portion of the diaphragm 28 is in contact with the other end surface of the operating rod 15 (the end surface on the side opposite to the regulating valve body 17), and is displaced in the axial direction of the operating rod 15. An operating space 30 is provided between the end surface of the diaphragm 28 on the operating rod 15 side and the inner bottom wall of the recess of the casing 12.
A third through hole 31 provided along the radial direction in the peripheral wall of No. 2
(external pressure equalization passage) and the gap 32 between the outer circumferential surface of the casing 12 and the inner circumferential surface of the expansion valve body insertion chamber 7 in the housing 2. It communicates with the inside of the side end of the insertion port 3, that is, the inside of the refrigerant passage chamber 7a.

A pressure generating means 33 is provided at the other end of the casing 12, facing the diaphragm 28. The pressure generating means 33 is a closed space 34a formed by attaching a substantially hemispherical cover 34 to the end of the plate 29 opposite to the diaphragm 28, and a gas that expands in proportion to the temperature is sealed in the closed space 34a. Inside is a through hole 36 bored in the plate 29.
It communicates with the inside of the gap 29a between the diaphragm 28 and the plate 29 via. Said cover 3
4, the temperature of the refrigerant passing through the refrigerant passage chamber 7a is transmitted into the closed space 34a, and in response to the temperature, pressure is generated to press the operating rod in the valve opening direction through the diaphragm 28. It's summery.

The closing member 6 has one end made of a threaded member and is screwed onto the inner peripheral surface of the insertion port 3, and the space between the closing member 6 and the inner peripheral surface of the housing 2 is airtightly sealed with an O-ring 37. , the O-ring 37 is fitted into an annular groove 38 on the outer peripheral surface of the other end of the closing member 6.

When the refrigerant in the high pressure chamber 21 leaks between the sliding surfaces of the outer peripheral surface of the large diameter portion 15a of the operating rod 15 and the inner peripheral surface of the operating rod fitting chamber 14, the leaked refrigerant is transferred to the refrigerant passage chamber 7a. A leak means is provided for causing the leak. The leak means is the large diameter portion 1 of the operating rod 15.
An annular leak groove 39 provided on the outer peripheral surface of 5a,
The annular leak groove 39 and the refrigerant passage chamber 7a are connected to each other by a leak passage 40 which is provided through the circumferential wall of the casing 12 in the radial direction. It communicates with the inside of the refrigerant passage chamber 7a via a gap 32 between the insertion chamber 7 and the inner circumferential surface of the insertion chamber 7. Note that the leak passage 40 and the third through hole 31 are connected to the casing 12.
is displaced by 180° in the circumferential direction, thereby preventing the refrigerant from the leak passage 40 from directly flowing into the third through hole 31.

Outer diameter D of the portion of the regulating valve body 17 that is located closer to the low pressure chamber 24 than the portion that contacts the acute-angled seat portion 19
is set to a value as close as possible to the diameter _D1 of the acute-angled seat portion 19.

The expansion valve 1 of the present invention configured as described above has the following features:
The first connection port 8 is connected to the discharge port 43a of the compressor 43 through the receiver tank 41 and the condenser 42,
The fourth connection port 11 is connected to the suction port 43b of the compressor 43,
The second connection port 9 is connected to the inlet 44a of the evaporator 44, and the third
It is incorporated into a refrigeration system by connecting the connection ports 10 to the outlets 44b of the evaporator 44, respectively.

Next, the operation of the expansion valve of the present invention having the above structure will be explained.

When the expansion valve body 4 is inserted into the housing 2, the expansion valve body 4 has an annular groove 27 ₁ on its outer periphery.
27 ₂ with O-rings 5 ₁ and 5 ₂ fitted respectively, and is inserted into the housing 2 through the insertion port 3. The inner peripheral surface of the housing 2 has a small diameter part 2a in the part where the O-rings 5 ₁ and 5 ₂ are installed opposite each other, and the inner diameter of the part on the insertion port 3 side other than the small diameter part 2a is the same as that of the O-rings 5 ₁ and 5 . ₂ , or a tapered portion 2c that connects the large diameter portion 2b and the small diameter portion _2a .
5 ₂ smoothly passes through the inner peripheral surface of the housing 2,
It will not be scraped off by the inner peripheral surface. Moreover, the contact area between the O-rings 5 ₁ , 5 ₂ and the inner circumferential surface of the housing 2 when the O-rings 5 ₁ , 5 ₂ pass through is smaller than in the conventional device.
Frictional resistance between the two is reduced, and the expansion valve body 4 can be easily inserted.

When the expansion valve main body 4 is attached to the housing 2, the outer circumferential surfaces of the O-rings 5 ₁ and 5 ₂ are in contact with the small diameter portion 2a of the inner circumferential surface of the housing 2 over the entire circumferential surface. Since the O-rings 5 ₁ and 5 ₂ have a predetermined outer diameter slightly larger than the inner diameter of the small diameter portion 2a when uncompressed, they are compressed by the inner circumferential surface of the housing 2 at an appropriate compression ratio. The O-rings 5 ₁ , 5 2 are formed between the inner circumferential surface of the insertion chamber 7 of the housing 2 and the outer circumferential surface of the casing 12 so that the inner circumferential surface of the housing 2 does not scrape off the inner circumferential surface of the housing ₂ during insertion. This results in a good seal. In addition, since the openings of the first connection port 8 and the second connection port 9 are the large-diameter portions 2b, the refrigerant passage volume is increased compared to conventional devices, and the flow resistance of the refrigerant is accordingly increased. The performance of the expansion valve also improves as the

When the expansion valve body 4 is removed from the housing 2, the O-ring 5 ₁ ,
5 ₂ is not scraped off to the inner circumferential surface of the housing 2, and the expansion valve body 4 can be easily extracted.

Note that in this embodiment, the portion of the inner circumferential surface of the housing from the large diameter portion to the small diameter portion is a tapered portion.
The present invention is not limited to this, and the present invention is not limited to this, but may have other shapes that allow the O-ring to pass through the portion from the large diameter portion to the small diameter portion without being caught when inserted into the housing of the expansion valve main body, such as the large diameter portion and the small diameter portion. It may also be a shape in which a stepped portion is formed between the portions, and the portion from the stepped portion to the small diameter portion is rounded.

(Effects of the invention) As detailed above, the expansion valve of the invention has a hollow cylindrical shape with one end open and the other end closed, and the opening serves as an insertion port and communicates with the condenser. a first connection port that communicates with the inlet of the evaporator on the side of the insertion port from the first connection port, a second connection port that communicates with the outlet of the evaporator on the side opposite to the insertion port from the first connection port. a housing having a third connection port and a fourth connection port facing the third connection port and communicating with the compressor on the peripheral wall thereof; and a housing that is removably inserted into the housing from the insertion port, and the first connection port. a first through hole communicating with the second connection port; and a second communication hole communicating with the second connection port.
an expansion valve body each having a through hole; and an expansion valve body provided on the outer circumferential surface of the expansion valve body on the side opposite to the insertion port from the first through hole, and between the first through hole and the second through hole. In the expansion valve, the first connection port and the second connection port of the housing include an O-ring that is fitted into an annular groove and holds the inner peripheral surface of the housing and the outer peripheral surface of the expansion valve body airtight. The opening part and the inner peripheral surface of the part closer to the insertion port than the opening of the second connection port are each a large diameter part whose inner diameter is larger than the outer diameter of the O-ring, and a non-large diameter part is formed from the large diameter part. The inner circumferential surface of the housing that extends to the radial portion is shaped so that the O-ring can pass through it without getting caught when the expansion valve body is inserted into the housing, so that the expansion valve body does not fit into the housing. By being able to prevent the O-ring from being scraped off by the inner circumferential surface of the housing during insertion, the sealing performance between the inner circumferential surface of the housing and the outer circumferential surface of the expansion valve body is ensured with a relatively simple structure. This has the effect that it can be improved. In addition, the frictional resistance between the inner peripheral surface of the housing and the O-ring during attachment and detachment is reduced, making attachment and detachment easier, and the passage volume from the first connection port to the second connection port is increased, reducing the flow resistance of the refrigerant. It also has the advantage of improving the performance of the expansion valve.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the expansion valve of the present invention installed in a refrigeration system, and FIG. 2 is a sectional view showing a conventional expansion valve. DESCRIPTION OF SYMBOLS 1... Expansion valve, 2... Housing, 2a... Small diameter part (non-large diameter part), 2b... Large diameter part, 3... Insertion port, 4... Expansion valve body, 5 ₁ , 5 ₂ ... O-ring,
8...First connection port, 9...Second connection port, 10...
3rd connection port, 11...4th connection port, 25...1st
Through hole, 26... Second through hole, 27 ₁ , 27 ₂ ... Annular groove, 42... Condenser, 43... Compressor, 44...
Evaporator.

Claims (1)

[Scope of utility model registration request] It has a hollow cylindrical shape with one end open and the other end closed, the opening serving as an insertion port, a first connection port communicating with a condenser, and evaporation from the first connection port to the insertion port side. a second connection port that communicates with the inlet of the evaporator, a third connection port that communicates with the outlet of the evaporator on the side opposite to the insertion port from the first connection port, and a position opposite to the third connection port that communicates with the compressor. a first through hole that is removably inserted into the housing from the insertion port and communicates with the first connection port, and a second communication hole that communicates with the second connection port; an expansion valve body each having a through hole; a side opposite to the insertion port from the first through hole of the expansion valve body;
and are fitted into annular grooves provided on the outer peripheral surface between the first through hole and the second through hole, and maintain the inner peripheral surface of the housing and the outer peripheral surface of the expansion valve body airtight. In the expansion valve having an O-ring, the inner peripheral surface of a portion of the housing where the first connection port and the second connection port open, and a portion of the expansion valve that is closer to the insertion port than the opening of the second connection port, respectively. A large diameter portion having an inner diameter larger than the outer diameter of the O-ring, and an inner circumferential surface of the housing from the large diameter portion to a non-large diameter portion when the O-ring is inserted into the housing. An expansion valve characterized by having a shape that allows it to pass through without getting caught.