Caulking fixation type power element and expansion valve using the same

Abstract

A caulking fixation type power element has a diaphragm, an upper lid member forming a pressure actuation chamber with a working gas, a receiving member provided with a through hole in its center portion and arranged in an opposite side to the upper lid member in relation to the diaphragm, and a stopper member arranged in a lower space formed between the diaphragm and the receiving member, and is integrated according to a circumferential welding by lapping the upper lid member, the diaphragm and the receiving member, the stopper member has a main body portion inserted to the through hole of the receiving member, and a flange portion having a larger diameter than the through hole and formed in one end of the main body portion, and the flange portion is arranged so as to come into contact with the receiving member from the lower space side.

Claims

1. An expansion valve comprising: a valve main body comprising an inlet port for receiving a high-pressure refrigerant, a valve chamber which is communicated with said inlet port, a valve hole, which is open to said valve chamber, a valve seat, which is formed in an inlet of said valve hole, and an outlet port for receiving the refrigerant that passes through said valve hole; a valve member arranged so as to face said valve seat; a caulking fixation type power element attached to an upper end of said valve main body; and a sealing member arranged between said power element and said valve main body, wherein said power element comprises: a diaphragm; an upper lid member, said upper lid member and said diaphragm forming a pressure actuation chamber for sealing a working gas therein; a receiving member for receiving the pressure actuation chamber, said receiving member comprising an annular outer peripheral portion, a first bottom surface portion provided in an inner side of the outer peripheral portion such that the first bottom surface portion is parallel to and at a lower elevation than the outer peripheral portion, and a second bottom surface portion provided further in an inner side of the first bottom surface portion such that the second bottom surface portion is parallel to and at a lower elevation than the first bottom surface portion, and a center portion with a through hole in the bottom surface, said receiving member being arranged such that said diaphragm is sandwiched between said upper lid member and said annular outer peripheral portion of said receiving member and such that a lower space is formed between said diaphragm and said receiving member; and a stopper member arranged in said lower space, wherein outer peripheral portions of said upper lid member, said diaphragm and said receiving member are integrated by a circumferential welding, wherein said stopper member comprises a main body portion and a flange portion, said flange portion being formed on an upper side of said main body portion with a diameter larger than said through hole of said receiving member, and wherein said stopper member is arranged such that said main body portion is inserted into said through hole and such that said flange portion is arranged in said lower space for contacting with the second bottom surface portion of said receiving member, wherein the valve main body further comprises a caulking portion configured to fixedly attach the outer peripheral portion of the caulking fixation type power element to the upper end of said valve main body in a state that a lower surface of the annular outer peripheral portion of the receiving member is directly in contact with the valve main body and an upper surface of the outer peripheral portion of the upper lid member is directly in contact with the caulking portion, wherein the sealing member is arranged between and in contact with the first bottom surface portion of the receiving member of the power element and the valve main body in a way such that the first bottom surface portion does not contact the valve main body, and wherein a diameter of the flange portion of the stopper member is smaller than a maximum diameter of the second bottom surface portion and the flange portion of the stopper member is arranged in a space portion of the lower space that is located above the second bottom surface portion.

2. The expansion valve according to claim 1, wherein said upper lid member further comprises a sealing hole for filling said working gas in the pressure actuating chamber, and a sealing plug for sealing said sealing hole.

3. A caulking fixation type power element for attaching to an upper end of a valve main body of an expansion valve via a caulking portion, comprising: a diaphragm; an upper lid member, said upper lid member and said diaphragm forming a pressure actuation chamber for sealing a working gas therein; a receiving member for receiving the pressure actuation chamber, said receiving member comprising an annular outer peripheral portion, a first bottom surface portion provided in an inner side of the outer peripheral portion such that the first bottom surface portion is parallel to and at a lower elevation than the outer peripheral portion, and a second bottom surface portion provided further in an inner side of the first bottom surface portion such that the second bottom surface portion is parallel to and at a lower elevation than the first bottom surface portion, said receiving member having a through hole in a center portion thereof and is arranged such that said receiving member and said upper lid member sandwiches said diaphragm therebetween and such that a lower space is formed between said diaphragm and said receiving member; and a stopper member arranged in said lower space, wherein outer peripheral portions of said diaphragm, said upper lid member and said receiving member are integrated according to a circumferential yielding, wherein said stopper member comprises a main body portion and a flange portion, said flange portion being formed on an upper side of said main body portion with a diameter larger than said through hole of said receiving member, wherein said stopper member is arranged such that said main body portion is inserted into said through hole and such that said flange portion is arranged in said lower space, wherein said diaphragm is deformed to expand the pressure actuation chamber in a state where said caulking fixation type power element has not yet installed to the expansion valve and thereby is in contact with said flange portion of said stopper member, wherein outer peripheral portions of the caulking fixation type power element are configured to be fixedly attached to an upper end of the valve main body by a caulking portion of the valve main body in a state that a lower surface of the annular outer peripheral portion of the receiving member is directly in contact with the valve main body and an upper surface of an outer peripheral portion of the upper lid member is directly in contact with the caulking portion, wherein the first bottom surface portion of the receiving member is configured in a way such that a sealing member is arranged between and in contact with the first bottom surface portion and the valve main body in a way such that the first bottom surface portion does not contact the valve main body, and wherein a diameter of the flange portion of the stopper member is smaller than a maximum diameter of the second bottom surface portion and the flange portion of the stopper member is arranged in a space portion of the lower space that is located above the second bottom surface portion.

4. The expansion valve according to claim 1, wherein said valve main body further comprises: a first surface facing to the second bottom surface portion; and a second surface substantially parallel to and at a higher elevation than the first surface, and wherein the sealing member is arranged between and in contact with the first bottom surface portion of the receiving member of the power element and the second surface of the valve main body.

5. The caulking fixation type power element according to claim 3, wherein said upper lid member further comprises a sealing hole for filling said working gas in the pressure actuation chamber, and a sealing plug for sealing said sealing hole.

Description

BRIEF EXPLANATION OF THE DRAWINGS

(1) FIGS. 1A and 1B are vertical cross sectional views showing a structure of an embodiment of a caulking fixation type power element according to the present invention, in which FIG. 1A shows a state before working gas is sealed therein, and FIG. 1B shows a state after the working gas is sealed therein;

(2) FIG. 2 is a vertical cross sectional view of an example of an expansion valve in the case that an embodiment of a caulking fixation type power element according to the present invention is applied; and

(3) FIGS. 3A and 3B are vertical cross sectional views showing a structure of a conventional caulking fixation type power element, in which FIG. 3A shows a state before the working gas is sealed therein, and FIG. 3B shows a state after the working gas is sealed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

(4) FIGS. 1A and 1B are vertical cross sectional views showing a structure of an embodiment of a caulking fixation type power element according to the present invention, in which FIG. 1A shows a state before working gas is sealed therein, and FIG. 1B shows a state after the working gas is sealed therein.

(5) As shown in FIG. 1A, a caulking fixation type power element 100 is constructed by an upper lid member 110, a receiving member 120 which is provided in its center portion with a through hole 121, a diaphragm 130 which is sandwiched between the upper lid member 110 and the receiving member 120, and a stopper member 140 which is inserted from the through hole 121 of the receiving member 120.

(6) A pressure actuation chamber 112 is formed in an inner portion between the upper lid member 110 and the diaphragm 130. Further, working gas, for example, such as inert gas is sealed in the pressure actuation chamber 112.

(7) Here, a sealing hole 113 for sealing the working gas is formed in a center portion of the upper lid member 110, and the sealing hole 113 is sealed by a sealing plug 114 after the working gas is sealed in, as shown in FIG. 1B.

(8) In the caulking fixation type power element 100 according to an embodiment of the present invention, the receiving member 120 is provided with a bottom surface portion having two stages of steps, and has a through hole 121 in its center portion. In other words, the receiving member 120 is provided with an annular outer peripheral portion 125, a first bottom surface portion 126 which is provided in an inner side thereof so as to be one stage down from the outer peripheral portion 125, and a second bottom surface portion (a flange receiving surface) 127 which is provided further in an inner side of the first bottom surface portion 126 so as to be one stage down from the first bottom surface portion 126, and the through hole 121 is formed in a center portion of the second bottom surface portion 127. Further, a lower space 122 is formed between the receiving member 120 and the diaphragm 130.

(9) Further, a stopper member 140 is inserted to the through hole 121 of the receiving member 120.

(10) The stopper member 140 has a main body portion 145 having a diameter which is approximately equal to or smaller than the diameter of the through hole 121 of the receiving member 120, a collar-like flange portion 141 which is formed in an upper surface side of the main body portion 145 so as to be larger in diameter than the through hole 121, and a receiving portion 142 which is formed into a hole shape from a lower surface of the main body portion 145 toward an upper side of an inner portion thereof. Further, a valve rod mentioned later is inserted to the receiving portion 142.

(11) The stopper member 140 receives the diaphragm 130 by an upper surface including the flange portion 141, and is arranged so that the main body portion 145 is inserted to the through hole 121 of the receiving member 120 and a lower surface of the flange portion 141 comes into contact with the second bottom surface member 127 of the receiving member 120 from the lower space 122 side.

(12) Next, a description will be given of a procedure of assembling the caulking fixation type power element 100 according to the embodiment of the present invention.

(13) First of all, the upper lid member 110, the diaphragm 130, the stopper member 140 and the receiving member 120 are arranged so as to establish a positional relationship as shown in FIG. 1A.

(14) Next, in a state in which outer peripheral portions of the upper lid member 110, the diaphragm 130 and the receiving member 120 are lapped, the outer peripheral portions are circumferentially welded, for example, by a TIG welding, a laser welding or a plasma welding and are integrated by forming a weld portion W.

(15) Subsequently, as shown in FIG. 1B, the working gas is sealed in the pressure actuation chamber 112 from the sealing hole 113 formed in the upper lid member 110, and is thereafter sealed by using the sealing plug 114 in relation to the sealing hole 113, for example, by means of the projection welding.

(16) At this time, since the diaphragm 130 is exposed to the pressure in such a manner as to protrude to the receiving member 120 side by the working gas which is sealed in the pressure actuation chamber 112, the diaphragm 130 comes into contact with an upper surface of the stopper member 140 which is arranged in the lower space 122 and is supported by the second bottom surface portion 127 of the receiving member 120, thereby being stably supported.

(17) By employing the structure mentioned above, in the caulking fixation type power element 100 according to the present invention, the diaphragm 130 is inhibited from being excessively deformed by coming into contact with the upper surface of the stopper member 140 after the working gas is sealed in the pressure actuation chamber 112. Therefore, even if the internal pressure of the working gas is enlarged, it is possible to inhibit the diaphragm 130 from being deformed beyond an allowable stress for an elastic deformation.

(18) Further, even if a plurality of caulking fixation type power elements 100 are thrown in a bag or a box for carrying in an offhand manner without arraying, the diaphragm 130 is protected by the receiving member 120. Therefore, it is possible to prevent the diaphragm 130 from being scratched or broken.

(19) FIG. 2 is a vertical cross sectional view of an expansion valve in the case that the caulking fixation type power element according to an embodiment of the present invention is applied.

(20) As shown in FIG. 2, a valve main body 10 of an expansion valve to which the caulking fixation type power element according to the present invention is applied is produced, for example, by applying a machine work to a member made of an aluminum alloy, and has an inlet port 20 to which a high-pressure refrigerant is introduced.

(21) The inlet port 20 is communicated with a valve chamber 24 via a small-diameter hole 20a. Further, the valve chamber 24 is communicated with an outlet port 28 for the refrigerant via a valve hole 26 which is formed coaxially with a valve rod 60.

(22) A valve seat 25 is formed between the valve chamber 24 and the valve hole 26, and a spherical valve member 40 arranged within the valve chamber 24 faces to the valve seat 25. Further, the valve member 40 is supported by a support member 42, and the support member 42 is supported by a plug 50 which blocks an opening portion of the valve chamber 24 via a coil spring 44.

(23) The plug 50 is threadably engaged with an opening portion 10a of the valve chamber 24 in the valve main body 10, and a spring force of the coil spring 44 supporting the valve member 40 can be regulated by regulating a screwing amount of the plug 50.

(24) Further, a seal member 54 is provided in an outer peripheral portion of the plug 50. As a result, the valve chamber 24 is sealed.

(25) The refrigerant fed out of the outlet port 28 is fed to the evaporator, and the refrigerant turning back to the compressor side from the evaporator enters into a return passage 30 provided in the valve main body 10 from a left side in the drawing, and passes through the return passage 30.

(26) In a top portion of the valve main body 10, the caulking fixation type power element 100 according to the embodiment of the present invention is attached to a cylinder portion 12 which is formed in the top portion of the valve main body 10 via a caulking portion 12a.

(27) Further, a seal member 64 such as an O-ring is arranged between the caulking fixation type power element 100 and the valve main body 10.

(28) At this time, an inner diameter of a communication passage 31 with the return passage 30, being formed in the top portion of the valve main body 10 is set to be greater than an outer diameter of the stopper member 140 of the caulking fixation type power element 100.

(29) As mentioned above, the upper surface of the stopper member 140 of the caulking fixation type power element 100 according to the present invention is arranged so as to support the diaphragm 130 in a contact manner, and an upper end portion of the valve rod 60 is inserted to the receiving portion 142 of the stopper member 140 so as to be in contact and is connected.

(30) According to the arrangement mentioned above, the stopper member 140 moves up and down on the basis of the deformation of the diaphragm 130 in response to the fluctuation of the internal pressure of the pressure actuation chamber 112 of the caulking fixation type power element 100, and the movement of the stopper member 140 is transmitted to the valve member 40 via the valve rod 60.

(31) When the expansion valve having the structure shown in FIG. 2 is assembled, the receiving member 120 of the caulking fixation type power element 100 is seated on the top portion of the valve main body 10 in such a manner that the stopper member 140 goes into the communication passage 31 with the return passage 30 formed in the top portion of the valve main body 10, in a state in which the valve rod 60 is inserted into the receiving portion 142 of the stopper member 140 in the caulking fixation type power element 100.

(32) Further, the caulking fixation type power element 100 is caulked and fixed to the valve main body 10 by deforming a leading end of the cylinder portion 12 of the valve main body 10 so as to come into contact with the upper lid member 110 of the caulking fixation type power element 100.

(33) By executing the attaching procedure mentioned above, the diaphragm be neither exposed to the external portion, and nor exposed to the pressure from the stopper member when being attached to the valve main body, in the caulking fixation type power element according to the present invention, in comparison with the case that the conventional caulking fixation type power element is employed.

(34) Therefore, according to the caulking fixation type power element of the present invention, it is possible to prevent the diaphragm from being broken when the power element is carried, or when the power element is attached to the expansion valve.

(35) Further, since the caulking fixation type power element can be positioned by a motion of attaching the valve rod to the receiving portion of the stopper member at the attaching time, it is possible to simplify a positioning motion in an assembling step.

DESCRIPTION OF REFERENCE NUMERALS

(36) 10 valve main body 12 cylinder portion 12a caulking portion 20 inlet port 24 valve chamber 25 valve seat 26 valve hole 28 outlet port 30 return passage 40 valve member 42 support member 44 coil spring 50 plug 54 seal member 60 valve rod 64 seal member 100 caulking fixation type power element 110 upper lid member 112 pressure actuation chamber 113 sealing hole 114 sealing plug 120 receiving member 121 through hole 125 (annular) outer peripheral portion 126 first bottom surface portion 127 second bottom surface portion 130 diaphragm 140 stopper member 141 flange portion 142 receiving portion 145 main body portion