JP2006322689A - Thermal expansion valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and inexpensively obtain stable valve opening characteristics by accurately sensing a refrigerant temperature in a thermal expansion valve. <P>SOLUTION: A disk 24 in the thermal expansion valve 1 is formed in hexagonal cross-sectional shape to enlarge a contact face with a refrigerant. Heat transfer performance to a temperature sensing part of the refrigerant temperature at an evaporator outlet is thereby improved, and the refrigerant temperature is accurately sensed in the temperature sensing part to obtain stable valve opening characteristics. As a result, there is no need to assemble accessory parts for shutting off the influence of an external atmosphere to be inexpensively achievable. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the refrigeration cycle, the present invention detects the temperature and pressure of the refrigerant flowing on the outlet side of the evaporator, controls the opening degree of the valve unit, squeezes and expands the refrigerant flowing in from the condenser side, and supplies it to the evaporator. Regarding the valve.

  Generally, a refrigeration cycle of an air conditioner for an automobile includes a compressor that compresses a circulating refrigerant, a condenser that condenses the compressed refrigerant, a receiver that stores the refrigerant in the refrigeration cycle and separates the condensed refrigerant into gas and liquid. An expansion valve that squeezes and expands the separated liquid refrigerant, and an evaporator that evaporates the refrigerant expanded by the expansion valve. Among these, for example, a temperature type expansion valve that senses the temperature and pressure of the refrigerant flowing on the outlet side of the evaporator and controls the flow rate of the refrigerant sent to the evaporator is used as the expansion valve.

  Such a temperature type expansion valve includes a body in which a first passage for allowing refrigerant to pass from the receiver to the evaporator and a second passage for allowing refrigerant returned from the evaporator to pass through to the compressor are formed. The power element which comprises a temperature sensing part is provided in the end of the body. This power element is configured, for example, by sealing a predetermined temperature sensing gas in a temperature sensing room partitioned by a diaphragm, sensing the temperature and pressure of the refrigerant flowing on the outlet side of the evaporator, and for driving supported by the body. The opening degree of the valve unit arranged in the first passage is controlled via the shaft.

  By the way, in such a temperature type expansion valve, a plate-like disk is interposed between the diaphragm and the shaft in order to transmit the operation of the diaphragm that senses and displaces the refrigerant to the shaft. There is. Since this disk directly exerts a force on the shaft that drives and controls the valve portion, it is necessary to operate stably along the axial direction of the shaft in order to keep the valve opening characteristic stable. For this reason, when the temperature type expansion valve is manufactured, the disk is aligned in the power element.

  In order to perform alignment of the disk with high accuracy and ease, the applicant has proposed the following temperature type expansion valve in Japanese Patent Application No. 2004-292274, which is a prior patent application, for example. FIG. 13 is an explanatory view showing a part of the manufacturing process of the temperature type expansion valve according to this prior patent application. (A) represents the process of the step of assembling the power element, and (B) represents the process of the step of assembling the power element to the body.

  The power element 101 of the temperature type expansion valve includes a disk-like disk 103 accommodated in the lower housing 102. The disk 103 has an extended portion 105 inserted into the contracted tube portion 104 of the lower housing 102 in the lower half portion thereof, and a hole portion 107 that is inserted through the end portion of the shaft 106 and locked at the center of the lower surface thereof. Have.

  Then, when assembling the power element 101, as shown in FIG. 3A, the extension portion 105 of the disc 103 is inserted into the contraction tube portion 104 of the lower housing 102, and the disc 103 is inserted into the lower housing 102. Placed on. As a result, the disk 103 is roughly positioned within the power element 101.

  Then, as shown in FIG. 5B, the power element 101 is assembled to the body 108 from which the shaft 106 is exposed. At this time, the disk 103 moves in a direction in which its axis is aligned with the axial position of the shaft 106. That is, the disc 103 is finally positioned at the same time that the power element 101 is assembled to the body 108.

  By the way, in such a configuration, in order to roughly position the disk 103 in the power element 101 in the previous stage, it is necessary to set a small clearance between the extending portion 105 and the contracted tube portion 104. For this reason, the refrigerant flowing through the second passage 109 is unlikely to pass through the clearance, and temperature sensing at the temperature sensing portion is solely due to heat transfer of the refrigerant temperature by the disk 103. At this time, the contact surface between the disk 103 and the refrigerant becomes substantially the black portion A0 in FIG. 5B, and the range that functions to sense the refrigerant temperature is limited.

Further, since the extending portion 105 provided on the disk 103 increases the thickness of the disk 103 to reduce heat transfer, it becomes a factor that hinders accurate sensing of the refrigerant temperature at the evaporator outlet.
In particular, such a temperature type expansion valve may be disposed in an engine room that is in a high temperature atmosphere due to the installation space, but if the temperature sensitive part is exposed to this high temperature atmosphere, the temperature of the refrigerant is higher than the refrigerant temperature. It reacts to the outside atmosphere, and the refrigerant temperature at the evaporator outlet that should be sensed cannot be accurately sensed, which may cause malfunction in the control of the valve portion.

In such a case, it is also conceivable to cover at least the temperature sensitive part of the temperature type expansion valve with a heat insulating cover made of a resin material or the like so as to be less susceptible to the influence of the ambient temperature (for example, see Patent Document 1) . Thereby, the influence with respect to a refrigerant | coolant temperature can be improved relatively, reducing the influence of external atmosphere.
JP 2004-345376 A (FIG. 1 etc.)

  However, such a structure for assembling accessory parts such as a cover leads to an increase in cost due to an increase in the number of parts, and therefore it is required to improve sensitivity to the refrigerant temperature without using accessory parts as much as possible.

  The present invention has been made in view of the above points, and provides a temperature type expansion valve that can be realized simply and at low cost, can accurately sense the refrigerant temperature, and can obtain a stable valve opening characteristic. The purpose is to do.

  In the present invention, in order to solve the above-described problem, the refrigerant that is provided in the refrigeration cycle is expanded and supplied to the evaporator by passing the refrigerant flowing in from the condenser side through the internal valve portion, and returned from the evaporator. In a temperature type expansion valve that senses the pressure and temperature of the valve and controls the opening degree of the valve part, a first passage for leading the refrigerant introduced from the condenser side to the evaporator via the valve part And a body having a second passage for introducing the refrigerant returned from the evaporator and leading it out to the compressor side, a first housing, the first housing, and the first housing. A space surrounded by the second housing communicating with the second passage on the opposite side to the first housing and the first housing and the second housing is partitioned And a diaphragm that holds a predetermined temperature-sensitive medium in a sealed space on the first housing side, and is disposed so as to abut on the diaphragm in the second housing, and the diaphragm Comprises a disk with which the shaft abuts on the opposite side, senses the temperature and pressure of the refrigerant flowing through the second passage, controls the opening of the valve by driving the shaft integrally with the disk, A power element that controls the flow rate of the refrigerant flowing through the first passage, and the disk engages with and engages with an end of the shaft opposite to the valve, An extension part arranged along the inner wall of the second housing, and when the power element is assembled, the extension part fits along the inner wall of the second housing. When the power element is assembled to the body, the positioning is completed by the engagement between the engagement portion and the shaft, and the extension portion is In order to increase the contact area between the refrigerant flowing in the second passage and the disc, the temperature formula is characterized in that it has a contact surface enlargement shape that enlarges the surface area exposed on the second passage side of the disc. An expansion valve is provided.

  In such a temperature type expansion valve, after the positioning of the disk is roughly performed at the time of assembling the power element, the disk is further highly accurately positioned by using this when the power element is assembled to the body. . In other words, since the positioning of the disk is automatically performed structurally in the flow of the assembly process of the temperature type expansion valve, the positioning operation becomes very easy. This highly accurate positioning ensures stable operation of the disk.

  Further, since the surface area exposed to the second passage side of the disk is enlarged by the contact surface enlargement shape, the contact area between the refrigerant flowing through the second passage and the disk is increased, and the heat transfer performance to the temperature sensing part is improved. . As a result, there is no need to assemble accessory parts such as a cover for blocking the influence of the external atmosphere.

  According to the temperature type expansion valve of the present invention, the contact area between the refrigerant flowing through the second passage and the disk is increased, so that the heat transfer performance of the refrigerant temperature at the evaporator outlet to the temperature sensing part is improved. For this reason, it is possible to accurately detect the refrigerant temperature in the temperature sensing portion and obtain a stable valve opening characteristic. As a result, it is not necessary to assemble an accessory for blocking the influence of the external atmosphere, and the cost can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
In this embodiment, the temperature type expansion valve of the present invention is embodied as a temperature type expansion valve applied to a refrigeration cycle of an automotive air conditioner. FIG. 1 is a central longitudinal sectional view showing the structure of the temperature type expansion valve. In the following description, for the sake of convenience, the positional relationship between the structures may be expressed as upper and lower with reference to the state of FIG.

  As shown in FIG. 1, a thermal expansion valve 1 includes a port 3 that receives a high-temperature and high-pressure liquid refrigerant from a receiver (capacitor side) on a side of a substantially prismatic body 2 formed of an aluminum material. A port 4 that supplies low-temperature and low-pressure refrigerant that has been squeezed and expanded by the temperature expansion valve 1 to the evaporator, a port 5 that receives refrigerant evaporated from the evaporator, and the refrigerant that has passed through the temperature expansion valve 1 to the compressor And a return port 6. The first passage 7 is constituted by the port 3 and the port 4 and the refrigerant passage connecting them, and the second passage 8 is constituted by the port 5, the port 6 and the refrigerant passage connecting them.

  A valve seat 9 is formed integrally with the body 2 in a portion of the first passage 7 communicating from the port 3 to the port 4, and a valve hole 10 is defined by the inner peripheral edge of the valve seat 9. On the upstream side of the valve seat 9, a ball-shaped valve body 12 that is supported by the valve body receiver 11 and constitutes a valve portion together with the valve seat 9 is disposed. In addition, a communication hole 13 is formed at the lower end of the body 2 so as to be substantially orthogonal to the first passage 7 and communicate with the outside. An adjustment screw 14 is screwed to seal the communication hole 13. ing. A concave spring receiving portion 15 is provided in the center of the front end surface of the adjusting screw 14, and a compression coil spring 16 is interposed between the valve body receiving portion 11 and the adjustment screw 14. One end of the compression coil spring 16 is inserted into the valve body receiver 11 and the other end is inserted into the spring receiver 15, and the valve body 12 is urged in a direction to seat the valve body 12 on the valve seat 9 via the valve body receiver 11. Yes. And the load of the compression coil spring 16 can be adjusted by adjusting the screwing amount of the adjusting screw 14 into the body 2. An O-ring 17 is interposed between the adjustment screw 14 and the body 2 to prevent the internal refrigerant from leaking outside through the communication hole 13.

  Further, a power element 20 constituting a temperature sensing part is provided in contact with the upper end of the body 2. The power element 20 is arranged so as to partition an upper housing 21 (corresponding to a “first housing”) and a lower housing 22 (corresponding to a “second housing”) made of stainless steel and a space surrounded by them. The diaphragm 23 is made of a flexible thin metal plate, and the disk 24 is disposed on the lower surface of the diaphragm 23. A predetermined temperature-sensing gas (corresponding to “temperature-sensing medium”) is sealed in the temperature-sensing greenhouse sealed by the upper housing 21 and the diaphragm 23. A communication passage 25 is formed at the upper end of the body 2 so as to communicate with the outside substantially orthogonal to the second passage 8 communicating from the port 5 to the port 6. The power element is sealed so as to seal the communication passage 25. 20 is screwed. Between the power element 20 and the body 2, an O-ring 26 that prevents the internal refrigerant from leaking outside through the communication path 25 is interposed.

  A shaft 27 that transmits the displacement of the diaphragm 23 to the valve body 12 is disposed below the disk 24. The shaft 27 passes through a through-hole 28 formed in the body 2 and is supported by the body 2 so as to be operable in its own axis direction. The through-hole 28 has a large-diameter portion 29 in the upper portion and a small-diameter portion 30 in the lower portion, and the upper open end of the large-diameter portion 29 is formed in a tapered chamfered shape. The large-diameter portion 29 of the through hole 28 is provided with an O-ring 31 that seals between the shaft 27 and the through hole 28, and is configured to prevent refrigerant bypass leakage in the through hole 28.

  The upper part of the shaft 27 is held by a holder 32 disposed across the second passage 8. The lower end portion of the holder 32 is fitted into the large diameter portion 29, and the lower end surface restricts the movement of the O-ring 31. The lower end portion of the shaft 27 passes through the small diameter portion 30 and reaches the valve hole 10. The upper end of the shaft 27 is inserted through a hole formed in the center of the lower surface of the disk 24, and supports the disk 24 from below.

  A coil spring 33 that urges the shaft 27 from the lateral direction is disposed on the upper portion of the holder 32. By adopting a configuration in which a lateral load is applied to the shaft 27 by the coil spring 33, the axial movement of the shaft 27 is prevented from sensitively reacting when the pressure of the high-pressure refrigerant in the port 3 varies. That is, the coil spring 33 constitutes a vibration damping mechanism that suppresses the generation of abnormal vibration noise due to the vibration of the shaft 27 in the axial direction.

  FIG. 2 is a partially enlarged view showing the structure around the power element of the thermal expansion valve according to the present embodiment. 3A and 3B are explanatory views showing the structure of the disk constituting the power element. FIG. 3A is a sectional view of the disk, and FIG. 3B is a bottom view of the disk. FIG. 4 is a bottom view of the power element.

  As shown in FIG. 2, the power element 20 has a cup-shaped upper housing 21 and a lower housing 22 each formed by press-molding a stainless steel material, with a disk 24 and a diaphragm 23 interposed therebetween. It is formed by arranging and welding along the outer peripheral edge of the joint.

  A circular hole 41 for introducing a temperature-sensitive gas is formed in the center of the end of the upper housing 21 opposite to the diaphragm 23, and is formed by the upper housing 21 and the diaphragm 23 through the circular hole 41. A temperature-sensitive gas is injected into the space. When the injection of the temperature sensing gas is completed, a metal ball 42 is welded so as to seal the circular hole 41, and a sealed space serving as a temperature sensing portion is formed.

  The lower housing 22 is a contracted tube portion 43 that extends and contracts in the vicinity of the opening opposite to the upper housing 21, and the upper end opening of the body 2 is formed at the outer periphery of the distal end of the contracted tube portion 43. A male screw part 45 that is screwed into a female screw part 44 formed in the part is provided around.

  The upper surface of the disk 24 abuts against the diaphragm 23, and the upper end of the shaft 27 is inserted and locked in a hole 46 (corresponding to an “engagement portion”) provided at the center of the lower end of the disk 24. .

  As shown in FIG. 3, the disk 24 has a disk-shaped main body 51 formed by forging an aluminum material. The main body 51 has an upper half extending outward in the radial direction to form a flange-like locking portion 52, and the lower surface of the locking portion 52 can contact and separate from the inner bottom surface of the lower housing 22. It is to be locked to. In addition, three communication grooves 53 extending radially in the radial direction are formed on the lower surface of the diaphragm 23 so that the refrigerant flowing from the second passage 8 through the communication passage 25 is allowed to pass therethrough, and the diaphragm 23 in the lower housing 22 is passed. It can be led to the lower surface of. The lower half of the main body 51 is an extended portion 54 having a hexagonal cross section that extends into the contracted tube portion 43 of the lower housing 22.

  Further, the hole 46 provided in the lower surface of the disk 24 has an inner diameter substantially equal to the diameter of the shaft 27 and a shaft having a locking surface for locking the distal end surface of the shaft 27 at the base end thereof. The insertion portion 55 and a tapered portion 56 whose diameter increases from the shaft insertion portion 55 toward the lower end opening end, and a predetermined spot facing surface 57 is provided at the opening end. Here, the clearance of the portion closest to the radial direction between the lower housing 22 and the disk 24 (specifically, the extending portion 54) is larger than the clearance of the portion closest to the radial direction between the disk 24 and the shaft 27. It is configured as follows.

  Further, as described above, since the cross section of the extending portion 54 of the disk 24 is hexagonal, as shown in FIG. 4, it is between the outer peripheral surface of the extending portion 54 and the inner wall surface 22 a of the lower housing 22. A predetermined space S is formed. Therefore, the refrigerant flowing through the second passage 8 is easily introduced into the space portion S, and the contact surface between the disk 24 and the refrigerant flowing through the second passage 8 is substantially the black portion A1 shown in FIG. It becomes larger than A0 shown in FIG. That is, the contact area between the refrigerant and the disk 24 is increased by the hexagonal cross section of the extending portion 54 of the disk 24 (corresponding to the “enlarged contact surface shape”). Will improve.

  FIG. 5 is an explanatory view showing a part of the manufacturing process of the temperature type expansion valve. (A) represents the process of the step of assembling the power element, and (B) represents the process of the step of assembling the power element to the body.

  As shown in FIG. 5A, when assembling the power element 20, the disk 24 is mounted on the lower housing 22 so that the extended portion 54 of the disk 24 is inserted into the contracted tube portion 43 of the lower housing 22. Put. Then, a diaphragm 23 is disposed so as to cover the disk 24, and the upper housing 21 is disposed so as to be sandwiched between the diaphragm 23 and the lower housing 22, and along the connecting portion between the upper housing 21 and the lower housing 22. Weld the outer circumference. And after inject | pouring the temperature sensing gas through the circular hole 41 of the upper housing 21, the power element 20 is obtained by welding the ball | bowl 42 and closing the circular hole 41. FIG. At this time, since the radial clearance between the extending portion 54 of the disk 24 and the lower housing 22 is relatively small, the disk 24 is roughly positioned in the power element 20. In the figure, since the cross-sectional position where the space portion S of the power element 20 can be seen is shown, the clearance between the extending portion 54 and the lower housing 22 appears to be large, but the extending portion 54 is seen in the lower housing 22. At the apex position of the hexagonal cross section closest to the inner wall surface 22a, the clearance is small (see FIG. 4).

  And as shown to the figure (B), this power element 20 is assembled | attached with respect to the body 2 which the shaft 27 exposed. At this time, the tip of the shaft 27 is introduced into the hole 46 of the disk 24 along the tapered portion 56, but since the disk 24 is not fixed in the power element 20, the disk 24 is actually The axis is moved in a direction to match the axial position of the shaft 27. That is, the disc 24 is finally positioned at the same time when the power element 20 is assembled to the body 2.

  Thus, after the disk 24 is roughly positioned in the power element 20 by the extended portion 54, the disk 24 is accurately positioned with respect to the body 2 and the power element 20 by the hole 46. In other words, this positioning is inevitably performed in the assembly process of the temperature type expansion valve 1 by the shape of the disk 24 and the mounting structure of the lower housing 22 and the shaft 27 and the disk 24. For this reason, an operator does not work for the positioning, and the assembly of the temperature type expansion valve 1 is performed simply and quickly.

  Returning to FIG. 1, the temperature type expansion valve 1 configured as described above senses the pressure and temperature of the refrigerant returning from the evaporator and passing through the second passage 8 with the power element 20, and the disk via the diaphragm 23. 24 is driven. When the temperature of the refrigerant is high or the pressure is low, the valve body 12 is pushed in the valve opening direction via the shaft 27 integrated with the disk 24 to increase the lift amount from the valve seat 9. When the temperature is low or the pressure is high, the valve element 12 is moved in the valve closing direction to reduce the lift amount from the valve seat 9 to control the valve opening. On the other hand, the liquid refrigerant supplied from the receiver flows into the space where the valve body 12 is located via the port 3 and is expanded by being squeezed and expanded by passing through the valve portion in which the valve opening degree is controlled. Become. The refrigerant exits from the port 4 and is supplied to the evaporator, where it exchanges heat with the air in the passenger compartment and returns to the port 5 of the temperature expansion valve 1. At this time, the temperature type expansion valve 1 controls the flow rate of the refrigerant supplied to the evaporator so that the refrigerant at the outlet of the evaporator has a predetermined degree of superheat, so that the refrigerant is completely evaporated from the evaporator to the compressor. Returned.

  FIG. 6 is an explanatory diagram showing the relationship between the refrigerant contact area of the temperature expansion valve and the refrigerant flow rate increase rate when the external ambient temperature is changed. In the figure, the horizontal axis represents the contact area (refrigerant contact area) between the refrigerant flowing in the second passage and the disk, and the vertical axis represents the rate of increase in the refrigerant flow rate in the valve section.

Here, the degree of influence on the valve opening characteristic due to the change in the external atmosphere of the temperature expansion valve is experimentally obtained. Specifically, a power element having a maximum disk diameter of 22.5 mm was used, and the rate of increase in the refrigerant flow rate flowing through the valve portion was calculated when the temperature of the external atmosphere was changed from 35 degrees to 70 degrees. . The refrigerant contact area was changed by changing the cross-sectional shape of the disk. Here, the refrigerant contact area in the case of adopting the configuration of this embodiment is 222mm ^2, the refrigerant contact area in the case of adopting the structure of the prior application shown in FIG. 13 was 143 mm ^2.

Thereby, it turns out that a refrigerant | coolant flow rate increase rate converges to the minimum value by making a refrigerant | coolant contact area into a predetermined value or more (222 mm < ² > in the same figure). In other words, as shown in FIG. 3, the disk 24 has a hexagonal cross section and the contact surface with the refrigerant is enlarged, and the contact area is increased to a predetermined value or more, so that the rate of increase in the refrigerant flow rate is substantially minimized and the valve is opened. It can be seen that the degree characteristic is stable.

  As described above, according to the temperature type expansion valve 1, heat transfer to the temperature sensitive part of the refrigerant temperature at the evaporator outlet is achieved by enlarging the contact surface with the refrigerant by making the shape of the disk 24 a hexagonal cross section. Performance is improved. For this reason, it is possible to accurately detect the refrigerant temperature in the temperature sensing portion and obtain a stable valve opening characteristic. As a result, it is not necessary to assemble an accessory for blocking the influence of the external atmosphere, and the cost can be reduced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The thermal expansion valve according to the present embodiment is substantially the same as the configuration of the first embodiment except that the contact surface enlarged shape provided on the disk is different. The description is abbreviate | omitted by attaching | subjecting the same code | symbol. FIG. 7 is a partially enlarged view showing the structure around the power element of the thermal expansion valve according to the present embodiment. FIG. 8 is an explanatory diagram showing the structure of the disk constituting the power element. (A) is a sectional view of the disc, and (B) is a bottom view of the disc.

  As shown in FIG. 7, the disk 224 constituting the power element 220 of the temperature type expansion valve 201 has an upper surface portion in contact with the diaphragm 23 and an upper end portion of the shaft 27 in a hole portion 46 provided at the center of the lower end surface. Is inserted and locked.

  As shown in FIG. 8, the disk 224 has a disk-shaped main body 251 formed by forging an aluminum material. The lower surface of the main body 251 is locked to the inner bottom surface of the lower housing 22 so as to be able to contact and separate. The lower half of the main body 251 is an extended portion 254 having a circular cross section that extends into the contracted tube portion 43 of the lower housing 22.

  Also, a circular recess 255 (corresponding to “enlarged contact surface shape”) having a predetermined depth is provided below the hole 46 provided in the disk 224 so as to open downward. Yes. The recess 255 has a size that spreads in the vicinity of the peripheral edge of the extension 254 and is sufficiently larger than the hole 46. Further, since the thickness of the disk 224 is set to be the same as the thickness of the disk 24 in FIG. 3, the hole 46 in the disk 224 is formed at a position (deep position) higher than the hole 46 of the disk 24. . Since the concave portion 255 is formed, the surface area of the lower surface of the disk 224 is increased by the inner peripheral surface. The contact surface between the disk 224 and the refrigerant flowing through the second passage 8 is substantially the black portion A2 in FIG. 7, and is larger than A0 shown in FIG. Further, since the recess 255 is formed, the contact surface between the disk 224 and the refrigerant flowing through the second passage 8 becomes close to the temperature sensitive part. As a result, the heat transfer performance to the temperature sensing part of the power element 220 is improved.

  Also in the present embodiment, the clearance in the portion closest to the radial direction between the lower housing 22 and the disk 224 is slightly larger than the clearance in the portion closest to the radial direction between the disk 224 and the shaft 27. However, the space portion S as shown in FIG. 4 is not provided between the lower housing 22 and the disk 224.

  As described above, also in the temperature type expansion valve 201, the concave portion 255 is provided in the disk 224 to enlarge the contact surface with the refrigerant, and further, the contact surface with the refrigerant is close to the temperature sensing portion. The heat transfer performance of the refrigerant temperature to the temperature sensitive part is improved. For this reason, it is possible to accurately detect the refrigerant temperature in the temperature sensing portion and obtain a stable valve opening characteristic. As a result, it is not necessary to assemble an accessory for blocking the influence of the external atmosphere, and the cost can be reduced.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and changes and modifications can be made within the spirit of the present invention. Not too long.

  FIG. 9 and FIG. 10 are explanatory diagrams showing modifications of the first embodiment, respectively. In these drawings, (A) represents a bottom view of the disk, and (B) represents a bottom view of the power element. In each figure, the same reference numerals are given to components that are substantially the same as those of the first embodiment.

  That is, in the first embodiment, as shown in FIGS. 3 and 4, the example in which the extending portion 54 of the disk 24 is configured to have a hexagonal cross section is shown, but for example, as shown in FIG. The extending portion 354 may be configured to have a triangular cross section. Thereby, the space S <b> 3 may be formed between the outer peripheral surface of the extending portion 354 and the inner wall surface 22 a of the lower housing 22.

  Alternatively, as shown in FIG. 10, the extending portion 454 of the disk 424 may be formed in a cross-sectional wave shape. Thereby, the space S4 may be formed between the outer peripheral surface of the extending portion 454 and the inner wall surface 22a of the lower housing 22.

Note that the shape of the extending portion of the disk is not limited to the shape shown in FIGS. 9 and 10, and various contact surface enlarged shapes can be employed.
FIG. 11 is an explanatory diagram illustrating a modification of the second embodiment. (A) is a sectional view of the disc, and (B) is a bottom view of the disc. In the figure, components that are substantially the same as those of the second embodiment are given the same reference numerals.

  That is, in the second embodiment, as shown in FIG. 8, an example in which a circular concave portion 255 is provided below the hole 46 of the disk 224 is shown, but for example, as shown in FIG. A ring-shaped recess 555 may be provided concentrically around the hole 46 provided on the lower surface of the extended portion 554. Or you may comprise the recessed part of another various shape, and may comprise a contact surface expansion shape.

  Furthermore, it is good also as a structure which combined each embodiment and each modification. FIG. 12 is an explanatory diagram illustrating a modification in which the first embodiment and the second embodiment are combined. In the figure, components that are substantially the same as those in the first and second embodiments are denoted by the same reference numerals.

  That is, for example, as shown in the figure, the extending portion 654 of the disk 624 may have a hexagonal cross section, and the concave portion 255 may be formed on the lower surface thereof. Or it is good also as a structure which combined the other modification.

It is a center longitudinal cross-sectional view showing the structure of this temperature type expansion valve. It is the elements on larger scale showing the structure around the power element of the temperature type expansion valve concerning this embodiment. It is explanatory drawing showing the structure of the disk which comprises a power element. It is a bottom view of a power element. It is explanatory drawing showing a part of manufacturing process of a temperature type expansion valve. It is explanatory drawing showing the relationship between the refrigerant | coolant contact area of a temperature type expansion valve at the time of changing external atmospheric temperature, and a refrigerant | coolant flow rate increase rate. It is the elements on larger scale showing the structure around the power element of the temperature type expansion valve concerning this embodiment. It is explanatory drawing showing the structure of the disk which comprises a power element. It is explanatory drawing showing the modification of 1st Embodiment. It is explanatory drawing showing the modification of 1st Embodiment. It is explanatory drawing showing the modification of 2nd Embodiment. It is explanatory drawing showing the modification which combined 1st Embodiment and 2nd Embodiment. It is explanatory drawing showing a part of manufacturing process of the temperature type expansion valve concerning a prior patent application.

Explanation of symbols

1,201 Thermal expansion valve 2 Body 7 First passage 8 Second passage 9 Valve seat 10 Valve hole 12 Valve body 20,220 Power element 21 Upper housing 22 Lower housing 23 Diaphragm 24,224,324,424,524,624 Disk 25 Communication path 27 Shaft 32 Holder 43 Reduced tube portion 46 Hole portion 54,254,354,454,554,654 Extension portion S, S3, S4 Space portion

Claims (6)

Provided in the refrigeration cycle, the refrigerant flowing from the condenser side is squeezed and expanded by passing through the internal valve part, supplied to the evaporator, and the valve part senses the pressure and temperature of the refrigerant returned from the evaporator In the temperature type expansion valve that controls the opening of
A first passage for leading the refrigerant introduced from the condenser side to the evaporator via the valve portion, and a second passage for introducing the refrigerant returned from the evaporator and leading to the compressor side A body having
Surrounded by a first housing, a second housing that is disposed opposite to the first housing and communicates with the second passage on the opposite side of the first housing, and the first housing and the second housing. A diaphragm which is arranged so as to partition the space, and which is held in a state where a predetermined temperature-sensitive medium is sealed in a sealed space on the first housing side, and is arranged so as to contact the diaphragm in the second housing; A disk with which a shaft abuts on the side opposite to the diaphragm, senses the temperature and pressure of the refrigerant flowing through the second passage, and controls the opening of the valve unit by driving the shaft integrally with the disk A power element for controlling the flow rate of the refrigerant flowing through the first passage;
With
The disc is
An engaging portion that engages and locks the end of the shaft opposite to the valve portion; and an extending portion that is disposed along the inner wall of the second housing;
When the power element is assembled, the extension portion is accommodated along the inner wall of the second housing, whereby provisional positioning is performed, and when the power element is assembled to the body, the engagement portion And is configured to complete positioning by engaging the shaft,
The extending portion has a contact surface enlargement shape for enlarging a surface area exposed on the second passage side of the disc in order to increase a contact area between the refrigerant flowing in the second passage and the disc;
A temperature-type expansion valve.   2. The temperature according to claim 1, wherein the contact surface enlarged shape is formed by an outer peripheral shape of the extending portion that forms one or a plurality of space portions with an inner wall surface of the second housing. Expansion valve.   The thermal expansion valve according to claim 2, wherein the second housing is formed in a cylindrical shape, and the extending portion is formed in a substantially polygonal cross section.   The thermal expansion valve according to claim 1, wherein the contact surface expansion shape includes a recess provided in a thickness direction of the disk on a surface of the extension portion facing the second passage.   The thermal expansion valve according to claim 4, wherein the contact surface enlarged shape is formed so as to communicate with a hole portion provided in the center of the extension portion and constituting the engagement portion. The said contact surface expansion shape is further formed by the outer periphery shape of the said extension part which forms one or several space part between the inner wall surfaces of the said 2nd housing. Temperature expansion valve.

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