JPH0632973U - Expansion valve power element - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the durability of the diaphragm with a simple structure. A protrusion (upper protrusion 20 and lower protrusion 21) for sandwiching the diaphragm 13 is provided near the periphery of the upper lid 14 and near the periphery of the lower lid 15, and the diaphragm 13 is sandwiched by the protrusions 20 and 21. By doing so, the portion sandwiched by the protrusions 20 and 21 serves as a driving fulcrum of the diaphragm 13, and no force is applied to the portion weakened by the heat effect during welding or brazing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power element for an expansion valve formed by sandwiching a diaphragm between an upper lid and a lower lid, and welding the periphery of the upper lid and the lower lid by welding or brazing.

[0002]

[Prior art]

 As a power element using a conventional diaphragm, as disclosed in, for example, Japanese Patent Laid-Open No. 61-91740, "a diaphragm having one or more beads of the same circular shape and an outer edge portion of the diaphragm. An upper lid and a lower lid, both sides of which are sandwiched and integrated, are provided. One of the upper lid and the lower lid has an outer edge clamping surface of the diaphragm and a stopper surface for restricting a movable range of the bead portion on the same plane. It is already known that "a diaphragm is used" or that a synthetic resin is interposed between the diaphragm and the upper and lower lids as shown in Japanese Patent Laid-Open No. 56-97672.

In the one disclosed in Japanese Patent Laid-Open No. 61-91740, the stopper surface of the upper lid or the lower lid formed to regulate the movable range of the bead portion of the diaphragm is flush with the outer edge portion clamping surface of the diaphragm. Since the variation in the clearance between the bead of the diaphragm and the stopper surface can be made only by the variation in the dimensional accuracy of the diaphragm, the maximum clearance amount can be halved and the generated stress value can be reduced within the specified value. The durability and reliability are improved.

In Japanese Patent Laid-Open No. 56-97672, a synthetic resin is interposed in the connecting portion between the diaphragm and the upper lid (first dish-shaped piece), and the resin adheres to the inner wall of the connecting portion. Thus, the sealing is ensured.

[0005]

However, in the conventional power element, for example, the power element disclosed in Japanese Patent Laid-Open No. 61-91740, as shown in FIG. 5, the peripheral edges of the upper lid 50 and the lower lid 51. It is known that the outer peripheral portion of the diaphragm has a low hardness due to the welding of the portions or the heat effect from the brazing portion 52. Further, the high pressure applied from below the diaphragm during the airtightness test deforms the upper lid 50 (or the lower lid 51) that holds down the outer peripheral portion of the diaphragm, resulting in a gap 54 between the diaphragm 53 and the upper lid 50 or the lower lid 51. The formation of the gap 54 causes the drive fulcrum of the diaphragm 53 to move from the normal position 55 to a position with weak strength close to the peripheral edge tip portion 56, which causes a problem that the durability of the diaphragm 53 decreases. .

Further, in the power element disclosed in Japanese Patent Laid-Open No. 56-97672, the work of adhering the resin to the connecting portion, for example, rotating the expansion valve of the liquid resin, and the centrifugal force thereof causes the inner wall of the connecting portion to contact. There is a problem in that not only the number of man-hours is required for performing the work of adhering, but also a large amount of cost is required for a special device and the like for performing this work.

Therefore, the present invention is to provide a power element of an expansion valve which has a simple structure and improves the durability of the diaphragm.

[0008]

[Means for Solving the Problems]

 In this invention, therefore, the diaphragm is sandwiched by the peripheral edges of the upper lid and the lower lid that are joined to each other, and the upper chamber defined by the upper lid and the diaphragm and communicating with the temperature-sensitive cylinder is defined by the lower lid and the diaphragm. In the power element of the expansion valve, which is formed by the lower chamber communicating with the external pressure equalizing pipe, the protrusions for sandwiching the diaphragm are provided near the peripheral edge of the upper lid and near the peripheral edge of the lower lid.

[0009]

Therefore, according to the present invention, the protrusion is provided near the periphery of the upper lid and the periphery of the lower lid, and the protrusion is configured to sandwich and hold the diaphragm. The part sandwiched between the parts serves as the driving fulcrum of the diaphragm, and no force is applied to the part weakened by the heat effect during welding or brazing, so that the durability of the diaphragm is improved and the above-mentioned problems can be achieved. is there.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

The expansion valve 1 shown in FIG. 1 constitutes a part of a cooling cycle, is arranged on the upstream side of an evaporator (not shown), and transforms the high-pressure liquid refrigerant sent from the condenser into a low-pressure mist. In the expansion valve 1, a high-pressure side passage 3 and a low-pressure side passage 4 which are perpendicular to each other are formed in the expansion valve 1, and the high-pressure side passage 3 and the low-pressure side passage 3 are formed. 4 is in communication with an orifice 5 which is opened and closed by a spherical valve portion 7 provided at one end of the valve rod 6. The spherical valve portion 7 is received by a receiving member 8. It is what has been.

Further, a spring 11 is elastically mounted between the receiving member 8 and the adjusting screw 10 screwed to the valve body 2, and the biasing force of the spring 11 is adjusted by rotating the adjusting screw 10. You can do it.

The power element 30 is fixed to the upper end of the valve body 2, and the retainer 12 to which the other end of the valve rod 6 contacts, a diaphragm 13 provided around the retainer 12, an upper lid 14, and a lower lid. 15, an upper chamber 16 defined by the diaphragm 13 and the upper lid 14, and a lower chamber 17 defined by the diaphragm 13 and the lower lid 15.

As shown in FIG. 2, the upper lid 14 has a cap shape having a substantially convex cross section, and has a conduit 18 at the center for communicating the upper chamber 16 with a temperature-sensing cylinder (not shown). The upper peripheral edge portion 22 holds the outer peripheral portion of one surface of the diaphragm 13, and the upper protruding portion 20 is formed inside the upper peripheral edge portion 22 by a predetermined distance.

As shown in FIG. 3, the lower lid 15 has a cup shape having a substantially concave cross section, and a through hole 24 into which the valve rod 6 is slidably inserted, and a through hole 24 (not shown). A communication hole 25 that communicates the outer pressure equalizing pipe 19 that communicates with the low pressure side pipe of the evaporator and the lower chamber 17, a lower peripheral edge portion 23 that clamps the outer peripheral portion of the other surface of the diaphragm 13, and the upper protrusion. The upper protrusion 20 and the lower protrusion 21 that holds the diaphragm 13 together are provided at a position facing the portion 20.

As shown in FIG. 4, in the power element 30, the diaphragm 13 is sandwiched between the upper peripheral edge portion 22 and the lower peripheral edge portion 23, the upper protrusion portion 20 and the lower protrusion portion 21, and the upper lid is provided. The outer circumferences of the peripheral portions of 14 and the lower lid 15 are formed by welding by welding or brazing.

In the expansion valve 1 having the above-described configuration, the pressure corresponding to the temperature from the temperature-sensing cylinder arranged in the low pressure side pipe of the evaporator (not shown) is supplied to the upper chamber 16 and the lower chamber 17 is externally equalized. Since the low pressure of the low-pressure side pipe of the evaporator is supplied via the pressure pipe 19, the diaphragm 13 is urged downward by the pressure difference between the pressure in the upper chamber 16 and the pressure in the lower chamber 17, and this urging force and the spring The valve portion 7 is moved to a position where the upward biasing force of the valve 11 is balanced, the flow rate of the refrigerant passing through the orifice 5 is adjusted, and the superheat of the evaporator (not shown) is kept constant.

Conventionally, the diaphragm 13 of the expansion valve 1 uses the end portion of the portion sandwiched by the upper peripheral edge portion 22 and the lower peripheral edge portion 23 as a driving fulcrum, and this portion is affected by heat during welding or brazing. The durability of the diaphragm 13 was reduced because it deteriorated and became weaker in strength, but in the present application, the drive fulcrum of the diaphragm is located at the portion sandwiched by the upper protrusion 20 and the lower protrusion 21. Since this part is a part having normal strength that is not affected by heat, sufficient durability can be secured.

Further, in the above embodiment, the upper protrusion 20 and the lower protrusion 21 are formed in an annular shape, but it is also effective if they are formed in an arc shape having a predetermined interval or a shape sandwiched by a plurality of points. It does not change.

[0020]

[Effect of device]

 As described above, according to the present invention, the drive fulcrum of the diaphragm is made to be a point squeezed by the projection formed at a predetermined distance from the welding or brazing position. Since the diaphragm can be made to be a part avoiding the outer peripheral part where the strength is deteriorated due to the heat influence, it is possible to secure the durability of the diaphragm and to maintain the stable accuracy of the power element.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an expansion valve according to an embodiment of the present invention.

FIG. 2 is a plan view of an upper lid according to an embodiment of the present invention.

FIG. 3 is a plan view of a lower lid according to an embodiment of the present invention.

FIG. 4 is an enlarged partial sectional view of a power element portion according to an embodiment of the present invention.

FIG. 5 is a partially enlarged sectional view of a conventional power element.

[Explanation of symbols]

 1 Expansion Valve 13 Diaphragm 14 Upper Lid 15 Lower Lid 16 Upper Chamber 17 Lower Chamber 20 Upper Protrusion 21 Lower Protrusion 30 Power Element

Claims (1)

[Scope of utility model registration request] 1. An upper chamber that holds a diaphragm by the peripheral edges of an upper lid and a lower lid that are joined to each other and that is defined by the upper lid and the diaphragm and communicates with a temperature-sensitive cylinder; and an evaporator that is defined by the lower lid and the diaphragm. In a power element of an expansion valve having a lower chamber communicating with the low-pressure side pipe of the expansion valve, a protrusion for sandwiching the diaphragm is provided in the vicinity of the peripheral edge of the upper lid and in the vicinity of the peripheral edge of the lower lid. Power element.