JPH11325661A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight of expansion valve members which are used for an air conditioner and controls the flow of a refrigerant and educe the manhour in processing. SOLUTION: An expansion valve 101 has a power element part 36' above the main body 30, and the working of a diaphragm 36a is transmitted to the valve disc 32b through a working rod 36f so as to adjust the opening of an orifice 32a. A refrigerant is put in from a passage 32, and is sent to the side of an outlet port 322 through an orifice 32a. The valve disc 32b s supported by a valve member 32c, and is energized in the direction of closing the orifice 32a through a pressure spring 32d. An adjusting screw 391 is a resinous one, and is screwed into the main body 30 by a thread part 391b. The end of the pressure spring 32d is supported by the support 391f of an opening 391e. The hexagonal hole 391j of the adjusting screw 391 is made at the bottom of a recess 191h, and it restricts the thickness-biased part of the resinous adjusting screw 391 to its minimum, thus the accuracy in molding is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve used for an air conditioner, a refrigeration system, etc., for controlling a flow rate of a refrigerant.

[0002]

2. Description of the Related Art FIG. 3 is a longitudinal sectional view showing a state in which a box-type expansion valve which has been widely used in the past is arranged in a refrigeration cycle of an air conditioner of an automobile or the like, and a schematic perspective view thereof as viewed from a direction A. As shown in FIG. 3 and 4, the expansion valve 10 has a prismatic valve body 30 made of, for example, aluminum, a condenser 5 in the refrigerant cycle 11, a first passage 32 through which refrigerant flows from the receiver 6 to the evaporator 8, and a compressor from the evaporator 8 to the compressor. A second passage 34 through which the refrigerant flowing toward 4 passes is formed in the valve body 30 so as to be vertically separated. Further, an orifice 32a and a valve chamber 35 provided in the first passage 32, a spherical valve body 32b disposed upstream of the passage 32 that controls the amount of refrigerant passing through the orifice 32a, and a valve body 32b The spring 32d has an adjusting screw 39 for pressing the spring 32d in the direction of the orifice 32a via the valve member 32c. The adjusting screw 39 is provided in the mounting hole 30 communicating with the valve chamber 35 of the first passage 32 from the lower end face of the valve body 30.
The O-ring 39a is mounted on the adjusting screw 39 so that the valve body 30 is airtightly sealed. The opening degree of the valve body 32b with respect to the orifice 32a is adjusted by the adjusting screw 39 and the pressing spring 32d.

[0003] Reference numeral 321 denotes an inlet port through which the refrigerant sent out from the receiver 6 and flowing toward the evaporator 8 flows, and the valve chamber 35 is continuous with the inlet port 321.
322 is an outlet port for the refrigerant flowing into the evaporator 8. In FIG. 4, reference numeral 50 denotes a bolt hole for attaching an expansion valve, and the lower portion of the valve body 30 is thinned. A driving force is applied to the valve body 30 to the valve body 32b in accordance with the outlet temperature of the evaporator 8 so that the orifice 3
A hole 37 having a smaller diameter and a hole 38 having a larger diameter than the hole 37 are formed coaxially with the orifice 32a through the second passage 34 at the upper end of the valve body 30 to open and close the valve body 2a. A screw hole 361 to which the power element portion 36 serving as a heat sensitive portion is fixed is formed.

The power element section 36 is provided with a stainless steel diaphragm 36a and an upper pressure working chamber 36b which is provided in close contact with each other with the diaphragm 36a therebetween by welding and forms two airtight temperature sensing chambers above and below the diaphragm. Upper cover 3 which constitutes each lower pressure working chamber 36c
6d, a lower cover 36h, and a sealing tube 36i for sealing a predetermined refrigerant serving as a diaphragm driving fluid in the upper pressure working chamber 36b. The lower cover 36h is screwed into the screw hole 361 via the packing 40. Lower pressure working chamber 36c
Is connected to the second passage 34 via a pressure equalizing hole 36e formed concentrically with the center line of the orifice 32a. Refrigerant vapor from the evaporator 8 flows through the second passage 34, and the passage 34 serves as a passage for a gas-phase refrigerant, and the pressure of the refrigerant vapor is applied to the lower pressure working chamber 36c via the equalizing hole 36e. . In addition, 342 is an inlet port into which the refrigerant sent from the evaporator 8 enters, and 341 is an outlet port as an outlet of the refrigerant sent to the compressor 4. In FIG. 4, the sealing tube 36i is omitted.

Further, the lower pressure working chamber 36c has a large-diameter dish-shaped top portion 37g in contact with the center of the lower surface of the diaphragm 36a, and the large-diameter hole 38 penetrates through the second passage 34. And slidably disposed therein, to transmit the refrigerant outlet temperature of the evaporator 8 to the lower pressure operating chamber 36c, and also to transmit the refrigerant pressure to the upper pressure operating chamber 36b and the lower pressure operating chamber 36c.
The aluminum temperature sensing rod 3 that slides in the large diameter 38 to provide a driving force in accordance with the displacement of the diaphragm 36a due to the pressure difference
6f and a smaller diameter than the temperature sensing rod 36f which is slidably disposed in the small diameter hole 37 and presses the valve body 32b against the elastic force of the urging means 32d according to the displacement of the temperature sensing rod 36f. Of the temperature sensing rod 36f.
7g contacts the lower surface of the diaphragm 36a as a receiving portion of the diaphragm 36a, the lower end of the temperature sensing rod 36f contacts the upper end of the operating rod 37f, and the lower end of the operating rod 37f is
b, and the valve drive rod is constituted by the temperature sensing rod 36f and the operating rod 37f.

Therefore, the orifice 32 of the first passage 32 is inserted into the pressure equalizing hole 36e from the lower surface of the diaphragm 36a.
That is, the valve body drive rod extending to a is concentrically arranged. The portion 37e of the operating rod 37f is formed thinner than the inner diameter of the orifice 32a.
The refrigerant passes through the inside of the orifice 32a. Further, the temperature sensing rod 36f has an O as a sealing member for ensuring airtightness between the first passage 32 and the second passage 34.
A ring 36g is provided.

A known diaphragm driving fluid is filled in the pressure operating chamber 36b above the pressure operating housing 36d, and a second passage 34 is provided in the diaphragm driving fluid.
And the heat of the refrigerant from the refrigerant outlet of the evaporator 8 flowing through the second passage 34 through the valve drive rod and the diaphragm 36a exposed to the pressure equalizing hole 36e communicating with the second passage 34. Is transmitted.

[0008] The diaphragm driving fluid in the upper pressure working chamber 36b gasifies in response to the transferred heat, and applies pressure to the upper surface of the diaphragm 36a. The diaphragm 36a is displaced up and down due to the difference between the pressure of the diaphragm driving gas applied to the upper surface and the pressure applied to the lower surface of the diaphragm 36a. The displacement of the center of the diaphragm 36a up and down is controlled by the valve body 32b via the valve body drive rod.
To move the valve body 32b toward or away from the valve seat of the orifice 32a. As a result, the flow rate of the refrigerant is controlled.

That is, since the temperature of the low-pressure gas-phase refrigerant sent from the outlet side of the evaporator 8, that is, from the evaporator, is transmitted to the upper pressure working chamber 36b, the pressure of the upper pressure working chamber 36b changes according to the temperature. Evaporator 8
Outlet temperature rises. That is, when the heat load of the evaporator increases, the pressure of the upper pressure working chamber 86b increases,
Accordingly, the temperature sensing rod 36f, that is, the valve body drive rod is driven downward to lower the valve body 32b, so that the opening degree of the orifice 32a increases. Thus, the supply amount of the refrigerant to the evaporator 8 increases, and the temperature of the evaporator 8 decreases. Conversely, the temperature of the refrigerant sent from the evaporator 8 decreases. That is, when the heat load of the evaporator decreases, the valve element 32b is driven in the opposite direction to the above, the opening degree of the orifice 32a decreases, the supply amount of the refrigerant to the evaporator decreases, and the temperature of the evaporator 8 increases. .

[0010] Further, as a conventional expansion valve, a type in which a predetermined refrigerant is sealed using a plug 36k as shown in FIG. 5 instead of the sealing tube 36i shown in FIG. 3 is known. The plug 36k is inserted so as to close the hole 36j formed in the stainless steel upper cover 36d, and the plug 36k is fixed to the hole 36j by welding.

The conventional expansion valve 10 'of FIG. 5 differs from the expansion valve of FIG. 4 only in that a predetermined refrigerant is sealed in the power element portion 36' by a plug 36k. Is the same as that of FIG.
The same or equivalent parts are denoted by the same reference numerals and description thereof is omitted. In FIG. 5, the refrigeration cycle is omitted.

In the conventional expansion valve shown in FIGS. 3 and 5, the adjusting screw 39 is made of metal, for example, aluminum, and the adjusting screw 39 is made of a perspective view shown in FIGS. 6 (a) and 6 (b). It has a substantially cylindrical shape as described above, a screw portion 39b formed on an outer peripheral portion for being screwed into the mounting hole 30a of the valve body 30 so as to be able to advance and retreat, and a groove portion 39c to which the O-ring 39a is mounted.
Step 39 formed between screw 39b and groove 39c
d and an opening 39 into which the lower end of the pressing spring 32d is inserted.
e, a support 39f for supporting the end of the spring 32d inserted into the opening 39e, and an end 39 forming the bottom of the adjusting screw.
g of a hexagonal hole 39h formed in the center of the g. The hexagonal hole 39h acts as an engagement portion of the tool.
For example, by inserting a hex wrench,
Is screwed into the valve body 30. Various shapes other than a hexagonal hole can be selected for the engaging portion of the tool. The adjusting screw 39 is formed in a substantially cylindrical shape so that the diameter of the opening 39e is smaller than the diameter of the screw 39b.
A ring 39a is mounted. FIGS. 6A and 6B are perspective views seen from the direction of the opening 39e and the bottom 39g, respectively.

[0013]

By the way, in the conventional expansion valve, it is conceivable that the adjusting screw 39 is made of resin from aluminum alloy in order to reduce the weight and the number of processing steps.
However, when the conventional adjusting screw is made of resin,
The shape has a thick part or a thin part. That is, the vicinity of the groove portion is a thin portion, and the vicinity of the engagement portion of the tool is a thick portion, that is, a so-called uneven thickness portion, which causes a difference in cooling rate after molding of the resin, and the size of the shape varies. There is a problem that occurs. This dimensional variation may not be able to be adjusted, especially in a thread portion formed on the outer periphery of the adjusting screw. The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an inexpensive and lightweight expansion valve that reduces uneven thickness portions when resinizing an adjustment screw of the expansion valve. To provide.

[0014]

In order to achieve the above-mentioned object, an expansion valve according to the present invention is provided with an opening to an orifice of a valve element due to a change in temperature of a refrigerant discharged from an evaporator by a refrigerant sealed in a temperature-sensitive chamber. The expansion valve for controlling the degree is characterized in that the adjusting screw for adjusting the opening degree of the valve body is made of resin and is provided with means for reducing the uneven thickness portion of the resin. The expansion valve according to the present invention is characterized in that the means is a concave portion formed at an end of the adjusting screw.

Further, an expansion valve according to the present invention is a temperature sensing chamber provided at an upper end of a valve body having a first passage through which a refrigerant flows from a receiver to an evaporator and a second passage through which a refrigerant flows from an evaporator to a compressor. A temperature expansion valve, which drives a valve body in accordance with the displacement of a diaphragm in the inside and adjusts an adjusting screw for adjusting a pressing force of a compression spring for adjusting an opening degree of the valve body so as to advance and retreat to a lower end portion of the valve body. In the above, the adjusting screw is made of resin,
It has a recess formed at the end thereof, and is provided with an engagement portion for a predetermined tool in the recess.

Still further, an expansion valve according to the present invention is characterized in that the resin is polyphenylene sulfide containing glass fiber. Therefore, according to the present invention, since the resin adjustment screw is provided with a means for reducing the uneven thickness portion, the uneven thickness portion can be minimized, the dimensional variation after molding is reduced, and the molding accuracy is reduced. And an expansion valve that is lightweight and inexpensive.
Further, according to the present invention, since the uneven thickness portion of the resin adjustment screw is reduced by the concave portion provided at the end of the expansion valve,
It can be manufactured at a low cost with a simple configuration.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of an expansion valve according to an embodiment of the present invention. Only the adjustment screw 391 is different from the conventional expansion valve 10 ′ shown in FIG. 5, the same or equivalent parts are denoted by the same reference numerals and description thereof is omitted. In the expansion valve 101 of FIG. 1, reference numeral 391 denotes an adjustment screw made of resin, for example, polyphenylene sulfide containing glass fiber.
As shown in the perspective views of FIGS. 2 (a) and 2 (b), it has a substantially cylindrical shape, and the device hole 30a of the valve body 30 of the expansion valve 101 of FIG.
It is screwed so that it can advance and retreat.

In FIG. 2, the adjusting screw 391 has a screw portion 391b, a groove portion 391c in which the O-ring 39a is provided, and a step portion 391d formed between the screw portion 391b and the groove portion 391c on its outer peripheral portion. . One end of the adjusting screw 391 has an opening 391e into which the lower end of the pressing spring 32d is inserted, and a support 391f that supports the end of the pressing spring 32d inserted into the opening 391e. The other end of the adjusting screw 391 has a concave portion 391h formed at an end portion 391g serving as a bottom of the adjusting screw 391, and a concave portion 391h.
1h has an internal square hole formed in a bottom portion 391i (shown in FIG. 1), for example, a hexagonal hole 391j.
Acts as an engagement portion of a tool, a hexagon wrench engages with the hexagonal hole 391j, the adjusting screw 391 is rotated, and moves up and down in the mounting hole 30a of the valve body 300. Thus, by forming the concave portion 391h in the adjusting screw 391, the concave portion 391h becomes a means for reducing the uneven thickness portion of the resin adjusting screw 391, and is particularly formed in a thin portion near the engaging portion of the hexagonal hole 391j. Therefore, the adjustment screw 391 made of resin
The so-called uneven thickness portion is reduced. As a result, the resin adjustment screw 391 can be configured to have a reduced thickness uneven portion as a whole. 2 (a) and 2 (b).
Are perspective views seen from the directions of the opening 391e and the bottom 391g, respectively.

The orifice 32 of the expansion valve 101 shown in FIG. 1 is formed by the resin adjusting screw 391 and the pressing spring 32d.
The opening degree with respect to a is adjusted.
Has the same function as the conventional expansion valve 10 '.

As described above, according to the present embodiment, the resin adjustment screw 391 has a configuration in which the uneven thickness portion is reduced, so that a difference in cooling rate after molding of the resin hardly occurs. Variation can be reduced, and an inexpensive and lightweight expansion valve can be obtained. Further, in an expansion valve using a resin adjustment screw, the degree of opening with respect to the orifice 32a can be adjusted with high accuracy as in a conventional expansion valve.

Although the present embodiment has been described using the conventional expansion valve 10 'shown in FIG. 5, in the present invention, the adjusting screw 39 in the conventional expansion valve 10 shown in FIG. 3 is shown in FIG. As described above, it is a matter of course that the resin adjusting screw may be provided with a means for reducing the uneven thickness portion, and the adjusting screw may be reduced in the uneven thickness portion.

[0022]

As is apparent from the above description,
The expansion valve of the present invention is made of a resin adjustment screw, and is provided with a means for reducing the uneven thickness portion. Therefore, the expansion valve can be formed by the resin adjustment screw having a reduced uneven thickness portion, and the light weight is reduced. In addition, it can be manufactured at a low cost. In addition, since the rate of temperature cooling after molding becomes equal in each part, the dimensional accuracy of the product can be improved even if a resin adjustment screw is used. Therefore, in the expansion valve using the adjusting screw made of resin, since the uneven thickness of the adjusting screw is reduced to reduce the dimensional variation, the opening degree of the orifice can be adjusted with high accuracy.

[Brief description of the drawings]

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

FIG. 2 shows the structure of an adjusting screw of the expansion valve of FIG. 1;
(A) is a perspective view seen from an opening, and (b) is a perspective view seen from a bottom.

FIG. 3 is a cross-sectional view showing a configuration of a conventional expansion valve.

FIG. 4 is a schematic perspective view of the expansion valve of FIG. 3;

FIG. 5 is a sectional view showing the configuration of another conventional expansion valve.

6A and 6B show the structure of an adjusting screw of the expansion valve of FIGS. 3 and 5, wherein FIG. 6A is a perspective view as viewed from an opening, and FIG. 6B is a perspective view as viewed from a bottom.

[Explanation of symbols]

 391 Adjusting screw 391b Screw part 391c Groove part 391e Opening part 391h Concave part 391j Square hole

Claims (4)

[Claims] An expansion valve for controlling an opening degree of a valve body to an orifice by a refrigerant sealed in a temperature-sensitive chamber by a change in temperature of a refrigerant sent from an evaporator.
An expansion valve, characterized in that an adjusting screw for adjusting the opening degree of the valve body is made of resin, and is provided with means for reducing the uneven thickness portion of the resin. 2. The expansion valve according to claim 1, wherein said means is a recess formed at an end of said adjusting screw. 3. According to a displacement of a diaphragm in a temperature-sensitive chamber provided at an upper end of a valve body having a first passage through which a refrigerant flows from the receiver to the evaporator and a second passage through which the refrigerant flows from the evaporator to the compressor. A temperature expansion valve in which an adjusting screw for adjusting a pressing force of a compression spring for adjusting an opening degree of the valve body is attached to a lower end portion of the valve body so as to be able to advance and retreat. An expansion valve having a concave portion formed at an end thereof and having an engaging portion for a predetermined tool in the concave portion. 4. The expansion valve according to claim 1, wherein the resin is glass fiber-containing polyphenylene sulfite.