JP4415096B2 - Expansion valve mounting structure - Google Patents

Description

  The present invention senses the temperature of the refrigerant on the outlet side of the evaporator constituting the refrigeration cycle, controls the operation of the internal valve body, squeezes and expands the refrigerant flowing in from the upstream side, and derives it to the evaporator side. The present invention relates to an expansion valve mounting structure to be mounted on an evaporator.

  Conventionally, as a refrigeration cycle for an automotive air conditioner system, a compressor that compresses a circulating refrigerant, a condenser that condenses the compressed refrigerant, a receiver that separates the condensed refrigerant into gas and liquid, and a separated liquid refrigerant 2. Description of the Related Art An expansion valve that is throttled and expanded and an evaporator that evaporates refrigerant expanded by the expansion valve are known.

  As an expansion valve, for example, a block-like body in which a refrigerant passage is formed and a valve seat provided in the body are detachably disposed, and the refrigerant sent out downstream through the refrigerant passage is arranged. A temperature type expansion valve including a valve body that adjusts the flow rate and a power element that controls the operation of the internal valve body by sensing the refrigerant temperature on the outlet side of the evaporator is used (see, for example, Patent Document 1).

Piping for connecting to the inlet / outlet of the evaporator and piping for connecting to the compressor / receiver side are respectively screwed and attached to the side portions of the expansion valve via fixing plates. Then, the pressure and temperature on the outlet side of the evaporator are introduced into the power element to control the operation of the valve body.
Japanese Unexamined Patent Publication No. 2000-289448 (FIG. 1, FIG. 4 etc.)

  However, since such an expansion valve mounting structure connects four pipes via two fixed plates, the number of parts is large, and the entire pipe mounting structure increases the manufacturing cost. It was.

  This invention is made | formed in view of such a point, and it aims at implement | achieving the expansion valve attachment structure which attaches a temperature type expansion valve to an evaporator simply and at low cost.

  In the present invention, in order to solve the above problem, in the expansion valve mounting structure for mounting the temperature type expansion valve that squeezes and expands the high-pressure refrigerant flowing from the upstream side to the evaporator constituting the refrigeration cycle and leads to the evaporator side, A pipe connection plate for locking and connecting one end portion of the refrigerant pipe connected to the outlet side of the evaporator while being pressed against the evaporator by being joined to the evaporator; Is a refrigerant introduction port that introduces the high-pressure refrigerant from the upstream side by connecting an accommodating part opened to the refrigerant pipe side to accommodate the temperature type expansion valve and an upstream side pipe connected to the temperature type expansion valve. And a refrigerant delivery port that communicates with the downstream side of the housing portion and is connected to the inlet side of the evaporator to deliver the decompressed refrigerant. The refrigerant pipe is disposed so as to abut on the temperature type expansion valve exposed from the accommodating portion of the pipe connection plate on the side opposite to the evaporator, and the pipe connection plate is disposed on the evaporator. Accordingly, an expansion valve mounting structure is provided in which the temperature type expansion valve is fixed to be sandwiched between the pipe connection plate and the refrigerant pipe.

  According to such an expansion valve mounting structure, the pipe connection plate used for connecting the refrigerant pipe to the evaporator, the accommodating portion for the temperature type expansion valve, and the refrigerant introduction port for introducing the high-pressure refrigerant into the temperature type expansion valve. A refrigerant delivery port for delivering the refrigerant decompressed by the temperature type expansion valve is formed, and the body of the temperature type expansion valve is constituted by this pipe connection plate.

  Furthermore, the pipe connection plate is joined to the evaporator, and at the same time, the temperature type expansion valve is fixed between the pipe connection plate and the refrigerant pipe so that the pipe connection plate is prevented from falling off from the accommodating portion. At this time, since the refrigerant pipe is in contact with the temperature type expansion valve, the refrigerant temperature on the outlet side of the evaporator flowing inside the refrigerant pipe can be sensed efficiently.

  According to the expansion valve mounting structure of the present invention, the body of the temperature type expansion valve is constituted by the pipe connection plate, and the refrigerant pipe also serves as a stopper for preventing the temperature type expansion valve from falling off. As a result, the number of parts is reduced, and the expansion valve mounting structure can be realized simply and at low cost.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the present embodiment, the expansion valve mounting structure of the present invention is applied to a refrigeration cycle of an automotive air conditioner system, and FIG. 1 is a cross-sectional view showing the structure of a temperature type expansion valve according to the present embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 1, the thermal expansion valve 1 includes a power element 10 that constitutes a temperature sensing part that senses the refrigerant temperature on the outlet side of the evaporator that constitutes the refrigeration cycle, and a power passage 10 that is actuated by the power element 10. A valve body 20 that adjusts the opening degree, and a spring receiver 30 (corresponding to a support member) that supports a compression coil spring 41 (corresponding to a biasing means) that biases the valve body 20 toward the temperature sensing unit. ing.

  The power element 10 includes a first housing 11, a second housing 12, a diaphragm 13 made of a flexible thin metal plate disposed so as to partition an internal space surrounded by the first housing 11, and a first housing of the diaphragm 13. And a disk 14 arranged on the surface on the 11 side. The sealed space surrounded by the first housing 11 and the diaphragm 13 constitutes a temperature sensing part, and the same refrigerant as that used in the refrigeration cycle is enclosed.

  The first housing 11 has a bottomed cylindrical main body formed by molding a metal plate, the bottom of which is swaged, and is formed in a shape that conforms to the shape of the outer peripheral surface of the refrigerant pipe connected to the outlet of the evaporator. Has been. Further, the center of the bottom portion protrudes inward of the sealed space, and the sealing hole 11 a provided for sealing the refrigerant at the center is sealed by resistance welding of the metal ball 15. The metal ball 15 is accommodated in a recess formed by a protrusion at the center of the bottom of the main body so as not to jump out from the bottom of the main body. Further, a flange portion 16 extending outward in the radial direction is formed in the opening portion on the opposite side to the bottom portion of the first housing 11. An O-ring 52 described later is attached between the flange portion 16 and the caulking portion at the bottom.

  The second housing 12 has a cylindrical main body formed by molding a metal plate. A flange portion 17 extending outward in the radial direction is formed at one end side opening of the second housing 12, and the outer peripheral portion of the diaphragm 13. Is abutted against the flange portion 16 of the first housing 11. Laser welding is performed along the outer peripheral part where both the flange parts 16 and 17 are joined, and the refrigerant is prevented from leaking outside from the sealed space. Further, the valve seat 18 is integrally formed by the inner peripheral edge of the opening on the other end side of the main body, and the internal space communicates with the upstream refrigerant flow path between the valve seat 18 and the flange portion 17. A communication hole 19 is formed.

  The diaphragm 13 is fixed so as to be sandwiched by a joint portion between the first housing 11 and the second housing 12, and the base end portion thereof serves as a support point a, and the first housing according to the pressure difference applied to both side surfaces. It is displaced to the 11 side or the second housing 12 side.

  The disk 14 has a disk-shaped main body, and is circumferentially laser-welded to the diaphragm 13 at a point b near the outer peripheral end thereof. For this reason, the circumferential portion connecting the intermediate point between the support point a and the neighboring point b defines the effective pressure receiving area of the diaphragm 13.

  The valve body 20 has a bottomed cylindrical main body 21 having an outer diameter smaller than the inner diameter of the second housing 12, and an end portion on the opposite side to the diaphragm 13 is open. A columnar protrusion 22 that protrudes toward the diaphragm 13 is provided on the bottom surface of the main body 21, and the outer peripheral edge of the protrusion 22 further protrudes slightly toward the diaphragm 13 to form a joint 23. The valve body 20 is joined to the diaphragm 13 and the disk 14 by spot welding at predetermined intervals along the joint portion 23. Further, a tapered valve portion 24 that extends outward in the radial direction and inclines toward the opening end side is formed at the opening end portion of the main body 21, and is configured to be detachable from the valve seat 18. . Furthermore, as shown in FIG. 2, a plurality of guide portions 25 projecting toward the inner peripheral surface of the second housing 12 are provided around the outer peripheral portion of the main body 21 at predetermined intervals. When the guide portion 25 slides along the inner peripheral surface of the second housing 12, the operation in the valve opening or closing direction is guided.

  The radial position of the intermediate point that defines the effective pressure receiving area of the diaphragm 13 and the radial position of the seating point when the valve portion 24 is seated on the valve seat 18 are configured to be substantially equal. When the valve portion 24 is seated on the valve seat 18, the effective pressure receiving area of the valve body 20 that receives high-pressure refrigerant and the effective pressure receiving area of the diaphragm 13 are configured to be substantially equal.

  The spring receiver 30 is formed by molding a metal plate, and includes a bottomed cylindrical main body 31 having an inner diameter substantially equal to the outer diameter of the second housing 12, and an open end portion of the spring receiver 30 is press-fitted into the second housing 12. It is fitted. Further, the opening end is provided with a flange portion 32 extending outward in the radial direction, and the port through which the communication hole 19 is communicated with the upstream refrigerant flow path by the flange portion 32 and the flange portion 17 of the second housing 12. 33 is configured. The flange portion 32 also has a stopper function when an O-ring 51 described later is attached to the temperature type expansion valve 1.

  In addition, a circular recess 34 is provided at the center of the bottom of the main body 31 so as to protrude on the opposite side of the valve body 20, and the valve body 20 is placed between the recess constituting the inside of the main body 21 of the valve body 20. A compression coil spring 41 that biases toward the 13th side is interposed. The elastic force (set value) of the compression coil spring 41 is set by the press-fit amount of the spring receiver 30 into the second housing 12. Further, a plurality of communication holes 35 for communicating the inside and the outside are formed at predetermined intervals on the outer peripheral portion of the concave portion 34 of the main body 31. Therefore, the refrigerant that has been reduced in pressure through the throttle passage formed between the valve portion 24 and the valve seat 18 is sent to the downstream refrigerant passage through the communication hole 35.

Next, the expansion valve mounting structure of the present embodiment will be described. FIG. 3 is a cross-sectional view illustrating the configuration of the expansion valve mounting structure, and FIG. 4 is a cross-sectional view taken along the line B-B in FIG. 3.
As shown in FIG. 3, this expansion valve mounting structure is a mounting structure for the above-described temperature expansion valve 1 to the evaporator (two-dot chain line in the figure). A pipe connection plate 70 is interposed to connect 60 while pressing 60 against the evaporator.

  The refrigerant pipe 60 has a tip connected to the outlet port of the evaporator, and an O-ring 81 is disposed between the outer peripheral surface of the tip of the refrigerant pipe 60 and the inner peripheral surface of the outlet port, to the outside of the refrigerant. To prevent leakage. The refrigerant pipe 60 is formed with a flange portion 61 that is crimped in the extending direction and protrudes outward in the radial direction in the vicinity of the tip. The refrigerant pipe 60 is bent substantially at a right angle in the vicinity of the connection portion with the evaporator, and is disposed so as to extend in parallel with the pipe connection plate 70.

  As shown in FIG. 4, the pipe connection plate 70 has a substantially rectangular parallelepiped main body 71 having a predetermined thickness, and the pipe diameter of the refrigerant pipe 60 is located at a position near the evaporator on one end face in the longitudinal direction. A locking portion 72 is provided which extends with a slightly larger width and locks the refrigerant pipe 60 with respect to the evaporator. Further, at a position where it does not interfere with the refrigerant pipe 60 slightly closer to the locking portion 72 than the center in the longitudinal direction of the main body 71, a joint portion 77 with an evaporator is provided so as to protrude laterally. The joint 77 is provided with a circular spot facing on the surface facing the refrigerant pipe 60, and an insertion hole 78 is formed through the center of the joint 77 to insert a bolt.

  Returning to FIG. 3, the main body 71 is formed with an accommodating portion 73 capable of accommodating the temperature type expansion valve 1 so as to penetrate the central portion in the thickness direction. The accommodating portion 73 has a stepped circular hole shape that is enlarged in a plurality of steps on the opposite side to the evaporator, and a circular boss-shaped refrigerant delivery port 74 connected to the inlet port of the evaporator from the end portion on the evaporator side. Is provided to extend. An O-ring 82 is disposed between the outer peripheral surface of the refrigerant delivery port 74 and the inner peripheral surface of the inlet port to prevent the refrigerant from leaking to the outside.

  Further, the main body 71 is provided with a refrigerant introduction port 75 penetrating from the side portion of the housing portion 73 toward the end surface opposite to the locking portion 72, and the temperature type expansion valve 1 and its upstream side are illustrated. The end of the upstream pipe 76 that connects to the receiver that is not connected is connected by press fitting. One end of the refrigerant introduction port 75 has an inner diameter that is substantially the same as the width of the port 33 of the temperature expansion valve 1, and the other end has an inner diameter that is substantially the same as the outer diameter of the upstream pipe 76. And the intermediate part is smoothly connected to the taper shape.

  In this accommodating portion 73, the temperature type expansion valve 1 is accommodated in a state where O-rings 51 and 52 for sealing are mounted on the outer peripheral surface thereof. For this reason, leakage of the refrigerant to the outside is prevented. Since a part of the refrigerant pipe 60 is in contact with the portion slightly exposed from the housing portion 73 of the temperature type expansion valve 1, the temperature type expansion valve 1 is prevented from falling off from the housing portion 73.

Next, an example of a method for assembling the expansion valve mounting structure of this embodiment will be described.
First, the upstream side pipe 76 is connected to the refrigerant introduction port 75 of the pipe connection plate 70, and then the temperature type expansion valve 1 around which the O-rings 51 and 52 are provided is inserted into the accommodating portion 73 from the spring receiver 30 side. And accommodate.

  Subsequently, an O-ring 82 is attached to the refrigerant delivery port 74 of the pipe connection plate 70, while an O-ring 81 is attached to the tip of the refrigerant pipe 60. In this state, the pipe connection plate 70 and the refrigerant pipe 60 are temporarily fixed so that the engaging portion 72 of the pipe connection plate 70 is fitted into the tip of the refrigerant pipe 60. At this time, the outer peripheral part of the refrigerant pipe 60 contacts the first housing 11 of the temperature type expansion valve 1.

  From this state, the pipe connection plate 70 and the refrigerant pipe 60 are attached to the evaporator body so that the refrigerant delivery port 74 and the tip of the refrigerant pipe 60 are connected to the inlet port and the outlet port of the evaporator, respectively. Then, a bolt (not shown) is inserted into the insertion hole 78 of the pipe connection plate 70, and this is screwed into a screw hole formed in the body of the evaporator (not shown) and fastened. Thereby, the pipe connection plate 70 is fixed to the evaporator. At this time, since the flange portion 61 of the refrigerant pipe 60 is locked to the locking portion 72 of the pipe connection plate 70 from the outside, the refrigerant pipe 60 is also fixed to the evaporator. Further, at this time, since the refrigerant pipe 60 comes into contact with and locks the temperature type expansion valve 1 from the outside, the temperature type expansion valve 1 is stably fixed to the pipe connection plate 70.

  Next, the operation of the temperature type expansion valve 1 will be described. FIG. 5 is a partially enlarged view of FIG. FIG. 6 is a graph showing the relationship between the refrigerant temperature and the refrigerant pressure, and the curve shown in the figure shows the temperature / pressure characteristics of the refrigerant filled in the temperature sensing part (sealed space).

  In the refrigeration cycle, the high-temperature and high-pressure liquid refrigerant that is compressed by the compressor, condensed by the condenser, and further separated into gas and liquid by the receiver is sent to the refrigerant introduction port 75 through the upstream pipe 76. Then, it flows into the internal space of the temperature type expansion valve 1 through the communication hole 19.

  The high-pressure refrigerant passes through a refrigerant passage between the valve body 20 and the second housing 12, and on the one hand, the refrigerant pressure is applied to the diaphragm 13, and on the other hand, the refrigerant pressure is applied to the valve body 20. At this time, the refrigerant pressure applied to the diaphragm 13 is applied to the valve body 20 joined thereto. As described above, the effective pressure receiving area of the diaphragm 13 and the effective pressure receiving area of the valve body 20 are almost equal. Since it is comprised so that it may become equal, the refrigerant | coolant pressure directly provided to the valve body 20 balances with this. For this reason, the pressure of the high-pressure refrigerant applied to the valve body 20 is substantially canceled and does not affect the operation of the valve body 20.

  For this reason, only the decompressed refrigerant pressure Px after being throttled and expanded after passing through the valve portion 24 is applied to the valve body 20 on the downstream side, and the refrigerant pressure Px is applied to the diaphragm 13. Will join.

  That is, as shown in FIG. 6, the valve body 20 includes the pressure P (Te) generated in the temperature sensing unit according to the refrigerant temperature Te on the outlet side of the evaporator transmitted from the refrigerant pipe 60 to the first housing 11. The valve opening direction or closing is performed so that the force due to the differential pressure (P (Te) −Px) with the refrigerant pressure Px on the outlet side of the thermal expansion valve 1 to counteract this, and the force due to the compression coil spring 41 are balanced. Operates in the valve direction. When expressed by a specific formula, the following formula (1) is obtained.

A (P (Te) -Px) = f0 + Kx (1)
Here, A is an effective pressure receiving area of the valve body 20 and the diaphragm 13, f0 is an initial load (set value) of the compression coil spring 41, K is a spring constant of the compression coil spring 41, and x is a valve portion. The lift amount from the 24 valve seats 18.

  That is, it is possible to control the operation of the valve body 20 by regarding the refrigerant pressure on the outlet side of the temperature type expansion valve 1 as substantially equivalent to the refrigerant pressure on the outlet side of the evaporator, thereby realizing the original function of the temperature type expansion valve. be able to.

The low-temperature and low-pressure refrigerant after being squeezed and expanded is sent to the evaporator side through the communication hole 35 and the refrigerant delivery port 74.
As described above, according to the expansion valve mounting structure of the present embodiment, the body of the temperature type expansion valve 1 is configured by the pipe connection plate 70, and the refrigerant pipe 60 prevents the temperature type expansion valve 1 from falling off. It also serves as a stopper. As a result, the number of parts is reduced, and the expansion valve mounting structure can be realized simply and at low cost.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the specific embodiment, and it can be changed and modified within the spirit of the present invention. Not too long.

  For example, in the above-described embodiment, the structure of the pipe connection plate 70 shown in FIGS. 3 and 4 is shown as a configuration example of the pipe connection plate, but the structure is a refrigerant connected to the outlet side of the evaporator. As long as it has a locking part for locking one end of the pipe, a storage part for storing the temperature type expansion valve, a refrigerant introduction port for introducing the high-pressure refrigerant, and a refrigerant delivery port for sending the decompressed refrigerant, Various modifications are possible.

  Further, as a configuration example of the temperature type expansion valve accommodated in the pipe connection plate, as shown in FIG. 1, a structure in which the valve body 20 is directly joined to the diaphragm 13 is shown. The power element that serves as the temperature sensing portion may be any one that contacts and is locked with the refrigerant pipe, and various modifications are possible. For example, using the structure described in Japanese Utility Model Publication No. 4-22228, a pressure equalizing hole penetrating in the axial direction is formed in a valve body integrated with an operating rod connected to a diaphragm, and the pressure equalizing hole It is good also as a temperature type expansion valve which one end side opens to a valve chamber, and the other end side opens to the power element side (temperature sensing part). In this case, the power element can sense the temperature of the evaporator outlet from the refrigerant pipe in contact with the power element, and can sense the pressure of the outlet of the expansion valve via the pressure equalizing hole. A high-pressure refrigerant can be configured not to be directly introduced to the power element side by interposing a seal member between the operating rod and the body.

Moreover, in the said embodiment, although the structure which the valve part 24 of the valve body 20 attaches / detaches to the valve seat 18 was shown, the thing like a spool valve by which the valve part 24 inserts / removes to the valve seat 18 may be used.
Furthermore, in the said embodiment, although the example which provided the compression coil spring 41 which urges | biases this to the diaphragm 13 side with respect to the valve body 20, and the spring receiver 30 which receives this was shown, for example of diaphragm 13 If the differential pressure applied to the valve body 20 can be appropriately controlled by adjusting the rigidity, the compression coil spring 41 and the spring receiver 30 can be omitted.

It is sectional drawing showing the structure of the temperature type expansion valve which concerns on embodiment. It is AA arrow sectional drawing of FIG. It is sectional drawing showing the structure of an expansion valve attachment structure. It is a BB arrow sectional view of Drawing 3. FIG. 4 is a partially enlarged view of FIG. 3. It is a graph which shows the relationship between a refrigerant | coolant temperature and a refrigerant | coolant pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal expansion valve 10 Power element 11 1st housing 12 2nd housing 13 Diaphragm 14 Disc 18 Valve seat 19 Communication hole 20 Valve body 22 Protrusion part 23 Joint part 24 Valve part 25 Guide part 30 Spring support 33 Port 34 Recess 35 Communication Hole 60 Refrigerant piping 61 Flange portion 70 Piping connection plate 72 Locking portion 73 Housing portion 74 Refrigerant delivery port 75 Refrigerant introduction port 76 Upstream side piping 77 Joint portion 78 Insertion hole a Support point b Neighborhood point

Claims (4)

In the expansion valve mounting structure for attaching the temperature type expansion valve that squeezes and expands the high-pressure refrigerant flowing from the upstream side to the evaporator constituting the refrigeration cycle,
While retaining one end of the refrigerant pipe connected to the outlet side of the evaporator, the pipe connection plate is connected to the evaporator while being pressed against the evaporator by being joined to the evaporator,
The pipe connection plate is
An accommodating portion opened to the refrigerant pipe side to accommodate the temperature type expansion valve;
A refrigerant introduction port for connecting the upstream pipe connected to the temperature expansion valve and introducing the high-pressure refrigerant from the upstream side;
A refrigerant delivery port that communicates with the downstream side of the accommodating portion and is connected to the inlet side of the evaporator to deliver a decompressed refrigerant;
With
The refrigerant pipe is disposed so as to abut on the temperature expansion valve exposed from the accommodating portion of the pipe connection plate on the side opposite to the evaporator, and the pipe connection plate is joined to the evaporator. The temperature expansion valve is fixed between the pipe connection plate and the refrigerant pipe,
An expansion valve mounting structure characterized by The temperature type expansion valve is
The first housing is joined to the first housing to form an internal space, and a valve seat is formed at an opening end opposite to the joint with the first housing, and the valve seat and the joint A second housing formed with a communication hole for communicating between the internal space and the upstream refrigerant flow path between the inner space and the portion, and disposed so as to partition the internal space by being interposed in the joint portion, A power element including a diaphragm that forms a sealed space that becomes a temperature-sensitive portion between the housing and the housing;
The second housing has a main body inserted through a predetermined refrigerant passage, and one end of the main body is directly joined to a surface of the diaphragm opposite to the first housing, and the other end of the main body Is a valve body provided with a valve part capable of contacting and separating with respect to the valve seat;
With
2. The structure according to claim 1, wherein an effective pressure receiving area of the valve body receiving pressure of the high pressure refrigerant in the internal space is substantially equal to an effective pressure receiving area of the diaphragm receiving pressure of the high pressure refrigerant. Expansion valve mounting structure. The temperature type expansion valve is
Urging means for urging the valve body toward the diaphragm;
The second housing is joined to the opposite side of the diaphragm of the second housing, supports the biasing means on the opposite side of the valve body, and communicates the internal space with the downstream refrigerant flow path. A support member having holes formed therein;
The expansion valve mounting structure according to claim 2, wherein each of the first housing, the second housing, and the support member is formed by molding a metal plate. The expansion valve mounting structure according to claim 2, wherein the first housing has a shape portion along a shape of an outer peripheral surface of a refrigerant pipe connected to an outlet side of the evaporator.

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