JP2011257032A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve that is reduced in manufacturing cost by eliminating the need for screw processing for fixing a power element to a valve body.SOLUTION: The valve body 100 has a fitting hole 128 in the upper part, and a ring groove 128b is formed in the inner peripheral surface thereof. The power element 200 has an elastic leg portion 222, which is inserted into the fitting hole 128 to engage a projection 224 with the ring groove 128b, thereby assembling the power element 200 on the valve body 100.

Description

  The present invention relates to an expansion valve that is incorporated in a refrigeration cycle and controls the flow rate of refrigerant flowing through an orifice in accordance with the temperature of the refrigerant.

  In a refrigeration cycle such as an air conditioner mounted on an automobile, a high-pressure liquid-phase refrigerant from a condenser (condenser) is passed through an orifice to a low pressure and sent to an evaporator (evaporator), and returns from the evaporator to a compressor. There is used a temperature expansion valve with a built-in temperature sensing mechanism that adjusts the amount of refrigerant passing by passing a low-pressure gas-phase refrigerant and controlling the opening of the orifice according to the temperature of the gas-phase refrigerant. (See Patent Document 1).

  As shown in FIG. 4 of the present application, the expansion valve disclosed in the above-mentioned Patent Document 1 is provided with a first passage 12 through which a refrigerant from the condenser to the evaporator passes, and the evaporator provided above the first passage 12. The valve body 10 having the orifice 14 provided in the middle of the second passage 13 and the first passage 12 through which the refrigerant going from the compressor to the compressor, and the valve seat 14a formed at the lower end of the orifice 14 are in contact with and separated from the orifice 14. A valve body 15 that opens and closes the valve body, an operating rod 16 that is slidably supported by the valve body 10, and a power element 20 that is provided above the second passage 13 and drives the valve body 15 via the operating rod 16. The flow rate of the refrigerant circulating through the refrigeration cycle is controlled according to the load level.

  The power element 20 is attached to the valve body 10 by screwing a male screw 20a formed on the power element 20 and a female screw 10a formed on the valve body 10. In this case, it is necessary to thread the male screw and the female screw, which is a factor that causes an increase in the manufacturing cost of the expansion valve. Further, in order to prevent the gas-phase refrigerant from leaking between the power element 20 and the valve body 10, the valve body 10 and the power element 20 are sealed with a separate seal member 30.

JP 2008-180476 A

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an expansion valve that can reduce the manufacturing cost by eliminating the need for screwing for fixing the power element to the valve body. There is to do.

In order to solve the above-described problems, the expansion valve according to the present invention includes, as a basic means, a first passage through which a refrigerant from the condenser to the evaporator passes, and a refrigerant that is provided above the first passage and is directed from the evaporator to the compressor. A valve main body having an orifice provided in the middle of the second passage and the first passage, a valve body that opens and closes the orifice, and a power element that drives the valve body are provided. The valve body includes a mounting hole and a first engaging portion of the power element formed downward from the upper surface thereof, and the power element is engaged with the first engaging portion. An elastically deformable leg formed with a joint, and the power element is engaged with the first engagement portion and the second engagement portion in a state in which the power element is inserted into the mounting hole; Is fixed to the valve body.
More specifically, the first engaging portion can be a ring groove, and the second engaging portion can be a convex portion that fits into the ring groove.
And the said convex part can be formed by the curling process which bend | folds the lower end part of the said leg part to a U shape outside, for example.
Moreover, the said convex part can also be formed by giving an embossing process from the inner side of the said leg part.
In this case, the convex portion can be formed such that an upper end portion engaged with the ring groove protrudes substantially horizontally.

  According to the present invention, since the screw fastening of the male screw and the female screw is not used as a structure for fixing the power element to the valve body, it is possible to avoid an increase in manufacturing cost due to forming the screw. Further, since the power element can be attached to the valve body with a single touch, the workability can be improved and the man-hours can be reduced.

It is a longitudinal cross-sectional view which shows one Example of the expansion valve by this invention. It is a longitudinal cross-sectional view which shows another Example of the expansion valve by this invention. It is an enlarged view which shows the principal part of FIG. It is sectional drawing which shows an example of the conventional expansion valve.

Hereinafter, embodiments of an expansion valve according to the present invention will be described with reference to the accompanying drawings.
1 is a cross-sectional view of the expansion valve, but since the cross-sectional structure is the same as that of FIG. 4, hatching indicating the cross-section is omitted to make it easy to see the lead lines.
The expansion valve shown in FIG. 1 is used in a refrigeration cycle of an air conditioner such as an automobile, and is disposed inside a prismatic valve body 100 made of aluminum or the like from a refrigerant outlet of a condenser via an receiver. The first passage 120, which is a high-pressure side passage through which the refrigerant toward the refrigerant inlet passes, and the second passage 122, through which the refrigerant from the refrigerant outlet to the refrigerant inlet of the compressor passes, are vertically separated from each other. Is formed.

In the middle of the first passage 120, a valve chamber 130 and an orifice 131 for adiabatic expansion of the refrigerant are formed. In the valve chamber 130, a spherical valve body 140 that opens and closes the orifice 131 by contacting and separating from a valve seat 132 formed on the inlet side of the orifice 131 is disposed, and the valve body 140 is supported by a support member 142. . The support member 142 is urged in a direction approaching the valve seat 132 by an urging force of an urging means such as a compression coil spring 146 disposed between the support member 142 and a plug 147 screwed to the lower end of the valve chamber 130. . A seal member 148 such as an O-ring is interposed between the plug 147 and the valve body 100.
The refrigerant that has passed through the orifice 131 is sent out from the outlet port 121 toward the evaporator.

  Further, the valve body 100 is formed with a through hole 124 that vertically cuts the partition wall 102 between the first passage 120 and the second passage 122. The through hole 124 has an operating rod 150 made of stainless steel or the like. Is slidably inserted. The lower end portion of the operating rod 150 is in contact with the valve body 140, and the upper end portion of the operating rod 150 is connected to a power element 200 serving as a temperature-sensitive drive unit described later.

  The power element 200 includes a diaphragm 230 made of a flexible metal thin plate, an upper cover 210 and a lower cover 220 that sandwich the periphery thereof, and an upper pressure chamber formed between the diaphragm 230 and the upper cover 210. A diaphragm driving medium enclosed in 240 and a plug 242 for sealing an opening for injecting the diaphragm driving medium into the upper pressure chamber 240 are provided. A lower pressure chamber 250 formed between the diaphragm 230 and the lower cover 220 is communicated with the second passage 122 through an opening hole 125 formed concentrically with the center line of the orifice 131 in the valve body 100. . The refrigerant vapor from the evaporator flows through the second passage 122, and the pressure of the refrigerant acts on the lower pressure chamber 250 through the through hole 125. The lower pressure chamber 250 is provided with a stopper portion 260 that contacts the lower surface of the diaphragm 230. The stopper portion 260 is supported by the lower cover 220 so as to slide up and down in the lower pressure chamber 250, and the operating rod. 150 is connected to the upper end of 150.

  The outlet side temperature of the evaporator is transmitted to the upper pressure chamber 240 directly or via the stopper portion 260 by the gas introduced from the opening hole 125. The pressure of the diaphragm driving medium in the upper pressure chamber 240 changes corresponding to the transmitted temperature and acts on the upper surface of the diaphragm 230. The diaphragm 230 is displaced up and down due to the difference between the pressure of the diaphragm driving medium acting on the upper surface of the diaphragm 230 and the refrigerant pressure acting on the lower surface of the diaphragm 230. The valve body 140 is moved closer to or away from the valve seat 132 of the orifice 131. As a result, the refrigerant flow rate is controlled. For example, when the heat load of the evaporator increases, the outlet temperature of the evaporator increases and the pressure of the upper pressure chamber 240 that receives the heat increases, and the operating rod 150 is driven downward accordingly, and the valve element 140 is Since it is pushed down, the opening of the orifice increases. As a result, the amount of refrigerant supplied to the evaporator increases, and the temperature of the evaporator decreases. Conversely, when the evaporator thermal load decreases, the opening of the orifice 133 decreases and the amount of refrigerant supplied to the evaporator decreases.

The upper end of the through hole 124 has a large diameter, and an anti-vibration spring member 160 that stably supports the operating rod 150 from the periphery is provided at this portion.
Further, the valve main body 100 is provided with a bolt hole 170 for mounting or the like as necessary.

The expansion valve according to the present embodiment is characterized by a structure in which the power element 200 is assembled to the valve body 100.
That is, the power element 200 has mounting legs 222 below the lower cover 220. The upper cover 210 and the lower cover 220 of the power element 200 are manufactured by pressing an elastic material such as a stainless steel material. Therefore, the leg part 222 has elasticity. In this embodiment, eight leg portions 222 are formed, and a lower end portion of each leg portion 222 is bent outwardly (curling) into a U-shape to form a convex portion 224.

A mounting hole 128 of the power element 200 into which the leg portion 222 is inserted is formed on the upper surface 100a of the valve body 100 coaxially with the orifice 131. The mounting hole 128 has an inner diameter larger than the inner diameter of the through hole 125 that communicates the second passage 122 and the lower pressure chamber 250 of the power element 200, and a ring groove 128 b is formed on the inner peripheral surface on the bottom side. Has been.
When the power element 200 is assembled to the valve body 100, the assembly is completed in one step of inserting the leg portion 222 of the power element 200 into the mounting hole 128 and pushing it in the axial direction. In order to facilitate the insertion of the leg portion 222, a tapered surface 128 a is formed at the inlet portion of the mounting hole 128.

  Since the leg portion 222 is made of stainless steel having a thickness of about 0.5 mm, for example, when the convex portion 224 is in contact with a portion above the ring groove 128b in the mounting hole 128, the leg portion 222 is elastically deformed radially inward of the mounting hole 128. When the convex portion 224 reaches the ring groove 128b, it elastically returns to the radially outer side. Thereby, the convex portion 224 is fitted into the ring groove 128b, and the upper end portion 224a is engaged with the upper surface of the ring groove 128b, so that the power element 200 is fixed to the valve body 100, and the assembly is completed.

A seal member 280 is disposed above the attachment hole 128. The seal member 280 is a ring having elasticity, and protrudes about 0.5 mm from the upper surface 100a of the valve body 100 in a free state.
When the power element 200 is assembled to the valve body 100, the convex portion 224 of the leg portion 222 engages with the ring groove 128b in a state where the elastic seal member 280 is compressed. Thus, the upper end portion 224a of the convex portion 224 is engaged with the upper surface of the ring groove 128b, and the convex portion 224 is almost completely prevented from coming out of the ring groove 128b. In addition, a seal between the valve body 100 and the power element 200 is reliably achieved.
In this expansion valve, as described above, since the power element 200 can be assembled to the valve body 100 with a single touch, the workability is extremely good and the number of man-hours can be greatly reduced.

FIG. 2 is a cross-sectional view of an expansion valve according to another embodiment of the present invention, and FIG. 3 is an enlarged view of a power element.
In this embodiment, the same components as those in the embodiment shown in FIG.

In this embodiment, embossing (P ₁ ) is applied to the lower part of each leg part 222 ′ from the inside to form a convex part 224 ′.

  As shown in FIG. 3, the convex portion 224 'has an upper end portion 224'a projecting outward substantially horizontally. Therefore, the convex portion 224 'once engaged with the ring groove 128b is not detached even when the power element 200' is pulled upward.

As described above, the expansion valve according to the present invention employs a mechanism that completes the assembly by simply inserting the power element into the valve body, instead of the conventional screw connection, as a structure for assembling the power element to the valve body. Yes.
Because of this mechanism, assembly can be completed with a single touch, and the number of man-hours can be reduced, and the machining of the threaded portion and the like can be omitted, so that the cost can be reduced.

100 Valve body 120 First passage 122 Second passage 128b Ring groove (first engagement portion)
130 Valve chamber 131 Orifice 140 Valve body 150 Actuating rod 200 Power element 210 Upper cover 220 Lower cover 222 Leg portion 224 Convex portion (second engaging portion)

Claims (6)

A first passage through which a refrigerant from the condenser to the evaporator passes, a second passage through which the refrigerant from the evaporator to the compressor passes, and an orifice provided in the middle of the first passage. An expansion valve comprising a valve body, a valve body that opens and closes the orifice, and a power element that drives the valve body,
The valve body includes a mounting hole and a first engagement portion of the power element formed downward from the upper surface thereof,
The power element includes an elastically deformable leg portion formed with a second engagement portion that engages with the first engagement portion,
An expansion valve, wherein the power element is fixed to the valve body by engaging the first engagement portion and the second engagement portion with the power element inserted into the mounting hole.   The expansion valve according to claim 1, wherein the first engagement portion is a ring groove, and the second engagement portion is a convex portion that fits into the ring groove.   The said convex part is an expansion valve of Claim 2 formed by the curling process which bends the lower end part of the said leg part outside in U shape.   The expansion valve according to claim 2, wherein the convex portion is formed by embossing from the inside of the leg portion.   The expansion valve according to claim 4, wherein an upper end portion of the convex portion is formed to protrude outward substantially horizontally.   The expansion valve according to claim 1, further comprising an elastic seal member that is disposed between the upper surface of the valve main body and the power element and that is compressed in a state where the power element is mounted in the mounting hole. .

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