WO2024219332A1

WO2024219332A1 - Accumulator and method for manufacturing same

Info

Publication number: WO2024219332A1
Application number: PCT/JP2024/014821
Authority: WO
Inventors: 侯史細川; 武治小澤; 真聖杉野; 晃平福山; 功速水
Original assignee: 株式会社不二工機
Priority date: 2023-04-19
Filing date: 2024-04-12
Publication date: 2024-10-24

Abstract

Provided are an accumulator with which it is possible to increase an amount of refrigerant that passes through the accumulator, and a method for manufacturing the same.　In the accumulator, an outflow pipe includes a small cylindrical portion which is inserted into and fixed to a refrigerant outflow hole, a large cylindrical portion which is disposed within a body portion and which has a cross-sectional area greater than that of the small cylindrical portion, and a tapered cylindrical portion connecting the small cylindrical portion and the large cylindrical portion, wherein: an inner circumferential surface of the outflow pipe has, along a refrigerant flow direction, a large inner circumferential surface, an intermediate inner circumferential surface connected to the large inner circumferential surface, and a small inner circumferential surface which is connected to the intermediate inner circumferential surface and which has a cross-sectional area smaller than the cross-sectional area of the large inner circumferential surface; the intermediate inner circumferential surface has a shape having a cross-sectional area that gradually decreases toward the small inner circumferential surface side; a gas-liquid separating member includes a main body that has a communicating portion and that faces a header, and an extension portion that extends from the main body to the tapered cylindrical portion; and the extension portion is sandwiched between the header and the outflow pipe in a state in which the extension part is in contact with the tapered cylindrical portion.

Description

Accumulator and manufacturing method thereof

The present invention relates to an accumulator and a method for manufacturing the same.

Receiver tanks and accumulators are used to separate the refrigerant circulating through the refrigeration cycle into gas and liquid and store it.

In the refrigeration cycle, the high-pressure gas-phase refrigerant discharged from the compressor flows into the condenser where it exchanges heat with outside air, is cooled, and condensed. The liquid refrigerant condensed in the condenser is then reduced in pressure by a pressure reducing device to become mist-like gas-liquid phase. The low-pressure refrigerant after pressure reduction absorbs heat from the air blown by the air conditioner blower in the evaporator and evaporates. As is well known, the air blown by the evaporator is temperature-adjusted in a heater core section (not shown) before being blown into the passenger compartment, for example. The refrigerant that passes through the evaporator is separated into gas and liquid in an accumulator before being drawn into the compressor.

For this reason, the accumulator header is formed with a refrigerant inlet and a refrigerant outlet that communicate with the inside of the accumulator. The refrigerant inlet is connected to the evaporator via piping, and the refrigerant outlet is connected to the compressor via piping.

Also known is an accumulator having a gas-liquid separation member (cup) that separates the refrigerant flowing in from the refrigerant inlet into liquid-phase refrigerant and gas-phase refrigerant, as disclosed in Patent Document 1.

JP 2014-52139 A

In order to improve the performance of the refrigeration cycle, there is a demand to increase the amount of refrigerant passing through the accumulator. One idea for increasing the amount of refrigerant passing through the accumulator is to use an outlet pipe with a large inner diameter that is placed inside the accumulator and connected to the refrigerant outlet of the header.

However, the diameter of the refrigerant outlet formed in the header is determined according to the piping that constitutes the flow path downstream of the accumulator, and this piping is often designed by the manufacturer that assembles the refrigeration cycle. In this way, the specifications of the refrigerant outlet of the accumulator are determined by the size of the designed piping, which creates the problem that it is difficult to use an outlet pipe with a large inner diameter regardless of the size of the piping connected to it.

The present invention was made in consideration of these problems, and aims to provide an accumulator that can increase the amount of refrigerant passing through, and a method for manufacturing the same.

In order to achieve the above object, the accumulator according to the present invention comprises:
a body portion having an opening at at least one end;
a header having a refrigerant inlet and a refrigerant outlet and closing one end of the body portion;
a gas-liquid separating member accommodated in the body portion, the gas-liquid separating member having a communication portion formed in a portion facing the refrigerant outflow hole, the communication portion communicating the header side with an opposite side;
an outflow pipe that is accommodated in the body portion, a portion of which is disposed in the communication portion, and which is connected to the refrigerant outflow hole,
the outflow pipe has a small cylinder portion inserted into and fixed to the refrigerant outflow hole, a large cylinder portion disposed within the body portion and having a cross-sectional area larger than that of the small cylinder portion, and a tapered cylinder portion connecting the small cylinder portion and the large cylinder portion,
The inner circumferential surface of the outflow pipe has, along a flow direction of the refrigerant, a large inner circumferential surface, an intermediate inner circumferential surface connected to the large inner circumferential surface, and a small inner circumferential surface connected to the intermediate inner circumferential surface and having a cross-sectional area smaller than that of the large inner circumferential surface, and the cross-sectional area of the intermediate inner circumferential surface is gradually reduced toward the small inner circumferential surface,
the gas-liquid separating member has the communicating portion, and includes a main body facing the header, and an extension portion extending from the main body to the tapered cylindrical portion, and is sandwiched between the header and the outflow pipe with the extension portion abutting against the tapered cylindrical portion.
It is characterized by:

In order to achieve the above object, a method for manufacturing an accumulator according to the present invention includes the steps of:
A header having a refrigerant outlet hole;
an outflow pipe connected to the refrigerant outflow hole;
a gas-liquid separating member disposed opposite the header and having a communication portion through which a portion of the outflow pipe is disposed;
A method for manufacturing an accumulator having the following features:
forming the outflow pipe having a small cylindrical portion, a large cylindrical portion having a cross-sectional area larger than that of the small cylindrical portion, and a tapered cylindrical portion connecting the small cylindrical portion and the large cylindrical portion by subjecting the pipe to a drawing process or a tube expansion process;
an extension portion is formed on a main body portion of the gas-liquid separating member, the main body portion being a portion that faces the header, the extension portion extending in a direction away from the main body portion;
With the small cylinder portion of the outflow pipe disposed in the communication portion, the extension portion and the tapered cylinder portion are brought close to each other so that the extension portion abuts against the tapered cylinder portion;
The small cylindrical portion is fixed to the refrigerant outflow hole of the header and the extension portion is abutted against the tapered cylindrical portion, thereby sandwiching the gas-liquid separation member between the header and the outflow pipe.

The present invention provides an accumulator that can increase the amount of refrigerant passing through it, and a method for manufacturing the same.

FIG. 1 is a vertical cross-sectional view of an accumulator according to a first embodiment. FIG. 2 is a cross-sectional view showing the header, the cup, and the inner pipe in an exploded state. FIG. 3 is a bottom view of the cup. FIG. 4 is an enlarged cross-sectional view showing the lower end of the inner pipe of this embodiment. FIG. 5 is a bottom view of a cup according to a first modified example. FIG. 6 is a vertical cross-sectional view of a cup according to a first modified example. FIG. 7 is an enlarged cross-sectional view showing the lower end of an inner pipe according to a second modified example. FIG. 8 is an enlarged cross-sectional view showing a lower end of an inner pipe according to a third modified example. FIG. 9 is an enlarged cross-sectional view showing a lower end of an inner pipe according to a fourth modified example. FIG. 10 is a vertical cross-sectional view of an accumulator according to the second embodiment. FIG. 11 is a vertical cross-sectional view of an accumulator according to the third embodiment. FIG. 12 is a vertical cross-sectional view of an accumulator according to the fourth embodiment.

The accumulator according to an embodiment of the present invention will be described below with reference to the attached drawings.

(First embodiment)
1 is a vertical cross-sectional view of an accumulator 1 according to a first embodiment, with only the left half of the strainer shown in cross section. The accumulator 1 has a tank body 2, a double pipe 5 arranged in the tank body 2, a bag 11 containing a desiccant (moisture absorbent) DA, a cup (also called a gas-liquid separating member) 16, and a strainer 20.

The tank body 2 includes a body 3 and a header 4. The body 3 is formed in a cylindrical shape with at least an opening at the top end, and as an example, is formed in a cylindrical shape with a bottom, and is a body portion with an opening at at least one end. The header 4 closes the opening at one end of the body 3. The header 4 is joined to the body 3 by circumferential joining, for example, via a weld 10, and closes the opening of the body 3. The body 3 and the header 4 are both formed of a metal such as an aluminum alloy. In this specification, the header 4 side is referred to as the upper side, and the bottom side of the body 3 is referred to as the lower side. As another example of the body 3, the body 3 may be a cylinder with openings at both ends. In this configuration, one opening is closed by the header 4, and the other opening is closed by a member separate from the body 3. In this configuration, the member that closes the other opening of the body 3 is formed of a metal such as an aluminum alloy.

For example, the header 4 is formed in a roughly disk-like shape, and has a refrigerant inlet hole 8 and a refrigerant outlet hole 9 formed to penetrate from top to bottom. An inner pipe (also called an outlet pipe) 6 that extends close to the inside bottom of the body 3 is connected to the refrigerant outlet hole 9. An outer pipe 7 is fitted to the outside of the inner pipe 6, thereby forming a double pipe 5.

Below the header 4, a cup 16 is provided to separate the mixed refrigerant (a mixture of gas and liquid phase refrigerant) from the refrigerant inlet 8 into high density liquid phase refrigerant and compressor oil (hereinafter referred to as "oil"), and low density gas phase refrigerant. The cup 16 is made of, for example, resin. The cup 16 has, for example, a cylindrical shape with a top, and is positioned opposite the refrigerant inlet 8 and the refrigerant outlet 9.

The inner pipe 6 is made of, for example, a metal, and an aluminum alloy is one example of the metal. The lower end of the inner pipe 6 is open, and the upper end is connected to the refrigerant outlet hole 9 of the header 4 by press-fitting, as described below. The outer periphery of the inner pipe 6 is fitted inside a number of pipe ribs 7a protruding from the inner periphery of the outer pipe 7, so that the inner pipe 6 is stably held within the outer pipe 7 with a gap therebetween.

The outer pipe 7 is made of, for example, synthetic resin, and is attached inside the body 3 with its upper end open. A cylindrical strainer 20 is provided at the bottom of the outer pipe 7. The strainer 20 is composed of a cylindrical case 21 with a bottom made of synthetic resin, and a cylindrical mesh filter 22 integrated with the case 21 by insert molding or the like. The strainer 20 may be abutted against, for example, the bottom surface of the internal space of the body 3. When the strainer 20 abuts against the bottom surface of the internal space of the body 3, the cup 16 is clamped between the body 3 and the header 4 via the inner pipe 6.

A bag 11 containing a desiccant DA is placed between the outer pipe 7 and the inner circumference of the body 3.

FIG. 2 is a cross-sectional view showing the header 4, cup 16, and inner pipe 6 in an exploded state. FIG. 3 is a bottom view of the cup 16. The axis of the inner pipe 6 is designated as L.

As shown in FIG. 2, the header 4 is made up of a large cylindrical portion 4a and a thin-walled annular portion 4b, which is smaller in diameter than the large cylindrical portion 4a, stacked in series, and a step 4c is formed between the large cylindrical portion 4a and the thin-walled annular portion 4b, with which the outer periphery of the upper end of the body 3 engages. The upper surface of the large cylindrical portion 4a is formed, for example, as a plane perpendicular to the vertical direction.

A cylindrical boss 4d is formed on the underside of the header 4, protruding downward from the large cylindrical portion 4a. A refrigerant outlet hole 9 is formed through the boss 4d, penetrating the header 4 from top to bottom, and a refrigerant inlet hole 8 is formed adjacent to the boss 4d, penetrating the header 4 from top to bottom. The underside of the boss 4d is formed, for example, on a plane that is in surface contact with the upper surface of the top wall 16b of the cup 16, which will be described later. The underside of the boss 4d is formed, for example, on a plane that is perpendicular to the axis L of the inner pipe 6.

The refrigerant outlet hole 9 has a large diameter hole 9a formed at the top and a small diameter hole 9b formed at the bottom. The inner diameter of the large diameter hole 9a is larger than the inner diameter of the small diameter hole 9b.

The cup 16 has a cup body (also simply called the body) 16e and an extension 16d. The cup body 16e faces the header 4 inside the body 3. The cup body 16e is formed by connecting a side wall 16a and a top wall 16b. A through hole 16c is formed in the top wall 16b. The through hole 16c is an example of a communication part in which a part of the inner pipe 6 is arranged. The communication part is formed in the cup body 16e in a shape that communicates the header 4 side with the opposite side, in other words, the bottom side of the body 3. The communication part is not limited to a through hole. In another example, the communication part may be a notch that penetrates the cup body 16e and opens to the side of the cup body 16e. For example, one or more ribs 16b1 are formed on the upper surface of the top wall 16b in a shape that protrudes upward. The ribs 16b1 form part of the upper surface of the top wall.

On the underside of the top wall 16b, an extension portion 16d is formed around the through hole 16c, for example, on the edge of the through hole 16c. The extension portion 16d is formed in a shape that extends from the cup body 16e to the tapered tube portion 6c and abuts against the tapered tube portion 6c of the inner pipe 6. A plurality of extension portions 16d, for example, four extension portions 16d, are formed. As an example, the extension portions 16d are formed in a wall shape. In this embodiment, the extension portions 16d are described as retaining walls 16d. The four retaining walls 16d are arranged, for example, at equal intervals on the edge of the through hole 16c. The retaining walls 16d are formed to be connected to the cup body 16e. The underside of the top wall 16b, excluding the retaining walls 16d, is flat.

Top wall 16b faces both refrigerant inlet hole 8 and refrigerant outlet hole 9. Furthermore, top wall 16b is a portion against which the refrigerant flowing in from refrigerant inlet hole 8 collides. Furthermore, top wall 16b faces the entire refrigerant inlet hole 8. The facing direction is the axial direction of refrigerant inlet hole 8.
Furthermore, the gap between the header 4 and the top wall 16b and the gap between the side wall 16a and the inner circumferential surface of the body 3 are approximately the same. Here, "approximately the same" may include an error in addition to being completely the same. That is, when the refrigerant flowing in from the refrigerant inlet hole 8 collides with the top wall 16b and flows downstream, it flows through the gap between the top wall 16b and the header 4 and the gap between the inner circumferential surface of the body 3 and the side wall 16a. If these gaps are "the same", the smooth flow of the refrigerant is maintained. In addition, if there is a small error in these gaps, the state in which the refrigerant flows smoothly can be maintained. The error is an error that can maintain the flow of the refrigerant smoothly in this way.

The retaining wall 16d has a shape that corresponds to, for example, the inner pipe 6. Here, the corresponding shape means a shape that follows the outer peripheral surface of the inner pipe 6, that is, the surface of the retaining wall 16d that faces and abuts against the inner pipe 6 is formed to have the same shape or approximately the same shape as the outer peripheral surface of the inner pipe 6.

The retaining wall 16d has a shape that is point-symmetrical with respect to the axis of the through hole 16c (which coincides with the axis L when assembled), and specifically consists of a rectangular plate-shaped base 16d1 on the top wall 16b side, a rectangular plate-shaped tip 16d2 on the lower end side, and a right-angled trapezoidal plate-shaped intermediate portion 16d3 that connects the base 16d1 and tip 16d2.

In a cross section passing through the axis of the through hole 16c, the outer surfaces of the base 16d1, the intermediate portion 16d3, and the tip portion 16d2 on the side away from the axis of the through hole 16c are, for example, parallel to the axis of the through hole 16c.

The distances between the inner surfaces of the base 16d1 and tip 16d2 on the side closer to the axis of the through hole 16c and the axis of the through hole 16c are R1 and R2, respectively, where R1<R2. That is, the inner surface of the base 16d1 has the same shape or approximately the same shape as a part of the outer periphery of a cylinder with a radius of R1. The inner surface of the tip 16d2 has the same shape or approximately the same shape as a part of the outer periphery of a cylinder with a radius of R2. Therefore, the inner surface of the middle portion 16d3 close to the axis of the through hole 16c is inclined at an angle θ1 with respect to the axis of the through hole 16c. The inner surface of the middle portion 16d3 has the same shape or approximately the same shape as a part of the outer periphery of a truncated cone with a radius of R2 at the bottom and a radius of R1 at the top. The inner diameter of the small diameter hole 9b and the through hole 16c is 2×R1.

The area of the upper surface of the top wall 16b of the cup 16 that contacts the lower surface of the boss 4d of the header 4 is formed in a plane that is in surface contact with the lower surface of the boss 4d. The area of the upper surface of the top wall 16b of the cup 16 that contacts the lower surface of the boss 4d of the header 4 is formed in a plane that is perpendicular to the axis of the inner pipe 6, for example. Alternatively, a part of the rib 16b1 may be formed in the area of the upper surface of the top wall 16b of the cup 16 that contacts the lower surface of the boss 4d of the header 4. In this configuration, a recess is formed in the lower surface of the boss 4d of the header 4 in which part of the rib 16b1 is disposed. This recess has a shape that, for example, fits into the rib 16b1.

The inner pipe 6 is made up of a small diameter cylindrical section (also called a small tube section) 6a, which is inserted into and fixed in the small diameter hole 9b of the refrigerant outflow hole 9, and a large diameter cylindrical section (also called a large tube section) 6b, which is larger in diameter than the small diameter cylindrical section 6a and is placed inside the body 3, connected by a tapered tube section 6c.

The inner pipe 6 is formed by drawing a pipe made of metal, for example aluminum. The outer diameter of the small diameter cylindrical portion 6a is smaller than the outer diameter of the large diameter cylindrical portion 6b, but by drawing the pipe, the fiber flow in the metal structure of the inner pipe 6 is continuous across the small diameter cylindrical portion 6a, the tapered tube portion 6c, and the large diameter cylindrical portion 6b. This continuous fiber flow can be seen by cutting the inner pipe 6 in the axial direction, and is therefore visible.

The outer circumferential radii of the small diameter cylindrical portion 6a and the large diameter cylindrical portion 6b are r1 and r2, respectively. r1 is equal to R1, or r1 is approximately equal to R1. "r1 is approximately equal to R1" includes cases where r1 is smaller than R1 and cases where r1 is larger than R1. r2 is equal to R2, or r2 is approximately equal to R2. "r2 is approximately equal to R2" includes cases where r2 is smaller than R2 and cases where r2 is larger than R2.

The outer peripheral surface of the tapered tube portion 6c is a truncated cone outer peripheral surface with a radius of r2 at the bottom end and a radius of r1 at the top end, or a curved surface substantially similar to the outer peripheral surface of a truncated cone with a radius of r2 at the bottom end and a radius of r1 at the top end.

Furthermore, the inner pipe 6 has a small diameter inner circumferential surface (small inner circumferential surface) 6e extending inside the small diameter cylindrical portion 6a, a tapered inner circumferential surface (intermediate inner circumferential surface) 6f extending inside the tapered tube portion 6c, and a large diameter inner circumferential surface (large inner circumferential surface) 6g extending inside the large diameter cylindrical portion 6b. Since the flow direction of the refrigerant inside the inner pipe 6 is from the lower end to the upper end, the large diameter inner circumferential surface 6g, the tapered inner circumferential surface 6f, and the small diameter inner circumferential surface 6e are arranged in this order along the flow direction of the refrigerant. Since the inner pipe 6 is formed by drawing, the small diameter inner circumferential surface 6e, the tapered inner circumferential surface 6f, and the large diameter inner circumferential surface 6g are smoothly connected to each other.

In a cross section passing through the axis of the through hole 16c, the outer peripheral surface of the tapered tube portion 6c is inclined at an angle θ2 with respect to the axis L of the inner pipe 6. θ2 is equal to θ1 or approximately equal to θ1. It is preferable that the angles θ1 and θ2 are, for example, 40 degrees ± 10 degrees.

The tapered tube portion 6c abuts against the middle portion 16d3 of the retaining wall 16. The outer peripheral surface of the tapered tube portion 6c and the inner surface of the middle portion 16d3 may be formed as curved surfaces that are in surface contact with each other. For example, when r1 is equal to R1 and r2 is equal to R2, the outer peripheral surface of the tapered tube portion 6c is a curved surface that is in surface contact with the inner surface of the middle portion 16d3.

The tapered tube portion 6c abuts against the middle portion 16d3 and the large diameter cylindrical portion 6b abuts against the tip portion 16d2, improving the accuracy of positioning the cup 16 relative to the inner pipe 6. In other words, the retaining wall 16d is not shaped to abut against the inner pipe 6 only on a single plane, but the boundary portion (corner or corner) between the base portion 16d1, middle portion 16d3, and tip portion 16d2 fits into the boundary portion (corner or corner) between the small diameter cylindrical portion 6e, tapered tube portion 6c, and large diameter cylindrical portion 6b of the inner pipe 6, improving the accuracy of positioning the cup 16 relative to the inner pipe 6.

In addition, if the shape of the tapered tube portion 6c is not identical to the shape of the inner pipe 6 but is approximately the same, for example if the dimensions are different, it may be the case that the boundary portion between the base 16d1 and the intermediate portion 16d3 of the retaining wall 16d does not match the boundary portion between the small diameter cylindrical portion 6e and the tapered tube portion 6c of the inner pipe 6, or the boundary portion between the intermediate portion 16d3 and the tip portion 16d2 of the retaining wall 16d does not match the boundary portion between the tapered tube portion 6c and the large diameter cylindrical portion 6b of the inner pipe 6. However, even in such cases, the intermediate portion 16d3 of the retaining wall 16d abuts against the tapered tube portion 6c of the inner pipe 6 and the tip portion 16d2 of the retaining wall 16d abuts against the large diameter cylindrical portion 6b of the inner pipe 6, improving the accuracy of positioning the cup 16 with respect to the inner pipe portion 6. Furthermore, the middle portion 16d3 and the tip portion 16d2 of the retaining wall 16d function as a guide when inserting the inner pipe 6 into the refrigerant outlet hole 9 of the header 4, making it easier to fix the inner pipe 6 to the refrigerant outlet hole 9.

Figure 4 is an enlarged cross-sectional view of the lower end of the inner pipe 6 of this embodiment. Up to the lower end 6h of the inner pipe 6 of this embodiment, the large-diameter inner circumferential surface 6g maintains a cylindrical shape, and the outer circumferential surface of the large-diameter cylindrical portion 6b also maintains a cylindrical shape. Furthermore, the lower end 6h is an end surface that is perpendicular to the axis L.

In FIG. 2, a pressure equalizing hole 6q is formed in the tapered cylindrical portion 6c of the inner pipe 6. The pressure equalizing hole 6q penetrates the inside and outside of the inner pipe 6. The pressure equalizing hole 6q is a hole that prevents the liquid phase refrigerant that has accumulated in the inner pipe 6 from being sucked up by the compressor when the compressor is started again after the refrigeration cycle has stopped (after the compressor has stopped operating). In other words, the pressure equalizing hole 6q allows not only the liquid phase refrigerant in the inner pipe 6 but also the gas phase refrigerant outside the inner pipe 6 to be sucked up by the compressor, thereby preventing the liquid phase refrigerant from being sucked up.

(Accumulator assembly process)
An example of a process for assembling the header 4 formed by cutting or the like, the cup 16 formed from a resin material, and the inner pipe 6 formed by drawing will be described. First, the lower end of the boss 4d of the header 4 is brought into contact with the upper surface of the cup 16 around the through hole 16c, and the small diameter hole 9b and the through hole 16c are aligned approximately coaxially. On the upper surface of the top wall 16b, the rib 16b1 is formed, for example, at a position that avoids the area where the boss 4d comes into contact. Therefore, in this embodiment, the lower end of the boss 4d comes into surface contact with the flat portion of the upper surface of the top wall 16b.

Then, the inner pipe 6 is brought close to the cup 16 from below. The small diameter cylindrical portion 6a of the inner pipe 6 is then inserted into the through hole 16c and press-fitted into the small diameter hole 9b of the header 4. The retaining wall 16d also functions to guide the small diameter cylindrical portion 6a as it enters the small diameter hole 9b.

When the small diameter cylindrical portion 6a is pushed toward the small diameter hole 9b, the outer peripheral surface of the tapered tube portion 6c abuts and engages with the inner surface of the middle portion 16d3 of the retaining wall 16d, so that the inner pipe 6 is locked and does not proceed any further toward the header 4. In this state, the tapered tube portion 6c abuts against the middle portion 16d3 and the large diameter cylindrical portion 6b abuts against the tip portion 16d2, improving the accuracy of positioning the cup 16 relative to the inner pipe 6. This allows the cup 16 to be held in an appropriate position.

At this time, as shown in FIG. 1, the small diameter cylindrical portion 6a is supported by abutting against the inner surfaces of the base portions 16d1 of the four retaining walls 16d, except for the portion pressed into the small diameter hole 9b. The outer peripheral surface of the tapered tube portion 6c is supported by abutting against the inner surfaces of the middle portions 16d3 of the four retaining walls 16d. Furthermore, the upper outer peripheral surface of the large diameter cylindrical portion 6b is supported by abutting against the inner surfaces of the tip portions 16d2 of the four retaining walls 16d. This allows the inner pipe 6 to be firmly held against the header 4 and cup 16, thereby suppressing vibrations, etc.

The outer pipe 7 and strainer 20 are attached to the inner pipe 6 of the assembly thus formed, and the accumulator 1 is completed by installing it inside the body 3 in which the bag 11 is arranged, and welding it to the header 4. Unless otherwise specified, the order of the above steps is not limited to the order described.

In the above example, the small diameter cylindrical portion 6a of the inner pipe 6 is inserted into the small diameter hole 9b of the header 4 while the tapered tube portion 6c of the inner pipe 6 and the middle portion 16d3 of the retaining wall 16d are brought closer together, so that the small diameter cylindrical portion 6a of the inner pipe 6 is fixed to the small diameter hole 9b of the header 4 and the tapered tube portion 6c of the inner pipe 6 is brought into contact with the middle portion 16d3 of the retaining wall 16d, thereby clamping the cup 16 between the inner pipe 6 and the header 4. In this way, it is not limited to simultaneously carrying out the operation of bringing the tapered tube portion 6c of the inner pipe 6 and the middle portion 16d3 of the retaining wall 16d closer to each other and the operation of inserting the small diameter cylindrical portion 6a of the inner pipe 6 into the small diameter hole 9b of the header 4 and fixing the small diameter cylindrical portion 6a to the small diameter hole 9b. In another example, the small diameter cylindrical portion 6a of the inner pipe 6 may be inserted into the through hole 16c to bring the tapered tube portion 6c and the middle portion 16d3 closer together so that the tapered tube portion 6c and the middle portion 16d3 are in contact with each other, and then while maintaining this contact state, the small diameter cylindrical portion 6a may be inserted into the small diameter hole 9b to fix the small diameter cylindrical portion 6a to the small diameter hole 9b, thereby clamping the cup 16 between the inner pipe 6 and the header 4.

According to this embodiment, a small diameter cylindrical portion 6a is formed to match the refrigerant outflow hole 9 of the header 4, and a large diameter cylindrical portion 6b is formed to obtain a flow rate according to the performance required of the accumulator 1, and further, the cup 16 can be fixed to the header 4 using the inner pipe 6. Therefore, it is possible to provide an accumulator 1 that can hold the gas-liquid separator and increase the amount of refrigerant passing through while preventing an increase in the number of parts.

In this embodiment, the inner pipe 6 is fixed to the header 4 by pressing the small diameter cylindrical portion 6a into the small diameter hole 9b, which eliminates the need for crimping the inner pipe 6, for example (no crimping portion is provided inside the refrigerant outflow hole 9). This eliminates the need to insert a crimping tool into the refrigerant outflow hole 9, and also eliminates the need to expand the diameter of the end of the inner pipe 6 by plastic deformation to engage with the step inside the refrigerant outflow hole 9. This allows the inner diameter of the small diameter cylindrical portion 6a to be expanded regardless of the inner diameter of the refrigerant outflow hole 9, reducing pressure loss inside the inner pipe 6 and ensuring a smooth flow of the refrigerant.

Furthermore, according to this embodiment, the cup 16 is attached to the header 4 by being sandwiched between the tapered cylindrical portion 6c formed on the inner pipe 6 and the boss 4d of the header 4, eliminating the need for bulge processing of the inner pipe 6. This reduces the resistance of the refrigerant flowing through the inner pipe 6 and suppresses the occurrence of turbulence, ensuring a smooth flow of the refrigerant.

The inner pipe 6 may be fixed to the header 4 by forming a female thread on the inner circumference of the small diameter hole 9b and a male thread on the outer circumference of the small diameter cylindrical portion 6a and screwing the female thread and the male thread together. The male thread of the small diameter cylindrical portion 6a is preferably formed by rolling, but may be formed by cutting. In particular, it is preferable to increase the thickness of the small diameter cylindrical portion 6a by plastic processing such as drawing so that the thickness is suitable for forming the male thread. In such a case, the thickness of the small diameter cylindrical portion 6a is thicker than the thickness of the large diameter cylindrical portion 6b. In addition, the tapered inner peripheral surface 6f of the inner pipe 6 and the outer peripheral surface of the tapered tube portion 6c are not limited to a shape with a uniform inclination angle with respect to the axis, and it is sufficient if the shape is such that the diameter decreases toward the header 4 side.

(Accumulator operation)
The operation of the accumulator 1 configured as above will be described with reference to Fig. 1. In the following description, an example will be described in which the accumulator 1 is disposed between the evaporator and compressor of a refrigeration cycle, moisture contained in the refrigerant from the evaporator is removed to generate gas refrigerant, and the gas refrigerant is returned to the compressor.

When the refrigerant is discharged from the evaporator, it is transported to the accumulator 1 through a connecting pipe (not shown). After reaching the accumulator 1, the refrigerant flows into the body 3 through the refrigerant inlet 8, and then collides with the upper surface of the cup 16, where it is separated into high-density liquid-phase refrigerant and oil, and low-density gas-phase refrigerant (gas refrigerant).

After gas-liquid separation, the liquid refrigerant and oil are stored in the body 3 due to their own weight. During this process, the liquid refrigerant and oil continue to separate, and the oil accumulates below the liquid refrigerant. At this time, the liquid level of the liquid refrigerant reaches a height position where part of the desiccant-containing bag 11 is immersed. Therefore, both the moisture contained in the liquid refrigerant and the humidity contained in the gas refrigerant are absorbed by the desiccant DA.

Meanwhile, the gas-phase refrigerant that has been separated into gas and liquid flows in from the upper opening of the outer pipe 7 and descends inside the outer pipe 7. It then turns around at the bottom of the outer pipe 7, passes over the lower end of the inner pipe 6, and flows inside, rising inside the inner pipe 6 and being led to the refrigerant outlet hole 9.

In this embodiment, the inner pipe 6 is formed with a tapered inner surface 6f, so the inner diameter gradually decreases toward the small-diameter inner surface 6e on the refrigerant outlet side, reducing pressure loss and ensuring an even smoother flow of the refrigerant.

The oil that accumulates at the bottom of the body 3 together with the liquid refrigerant moves to the bottom side of the body 3 due to differences in specific gravity and properties compared to the liquid refrigerant, and is sucked into the gas refrigerant that is sucked into the compressor suction side, passing through the mesh filter 22 of the strainer 20, the oil return hole 7e, and the internal space of the inner pipe 6, in that order, before being returned to the compressor suction side together with the gas refrigerant and circulated. As it passes through the mesh filter 22, foreign matter such as sludge is captured and removed from the circulating refrigerant (including oil).

(First Modification)
Fig. 5 is a bottom view of the cup 16A according to the first modified example. Fig. 6 is a vertical cross-sectional view of the cup 16A according to the first modified example. In this modified example, instead of the configuration in which a plurality of extensions (retaining walls) are provided, the extensions are formed in a cylindrical shape. More specifically, as the extensions, a retaining cylinder 16Ad is formed on the underside of the top wall 16b around the through hole 16c, for example, on the edge of the through hole 16c. Other configurations are the same as those in the above-mentioned embodiment, so repeated explanations will be omitted.

The retaining cylinder 16Ad has a shape that is coaxial or approximately coaxial with the axis L of the through hole 16c, and specifically consists of a cylindrical base portion 16Ad1 on the top wall 16b side, a tip cylindrical portion 16Ad2 on the lower end side, and an intermediate cylindrical portion 16Ad3 that connects the cylindrical base portion 16Ad1 and the tip cylindrical portion 16Ad2.

The outer diameter of the retaining cylinder 16Ad is uniform. The inner radii of the cylindrical base 16Ad1 and the tip cylindrical portion 16Ad2 are R1 and R2, respectively, where R1<R2. The inner circumference of the intermediate cylindrical portion 16Ad3 is inclined at an angle θ1 with respect to the axis of the through hole 16c.

According to this modified example, the holding cylinder 16Ad of the cup 16A abuts against the outer peripheral surface of the inner pipe 6 all around. Specifically, except for the portion pressed into the small diameter hole 9b of the small diameter cylindrical portion 6a of the inner pipe 6, the holding cylinder 16Ad abuts against and is supported by the inner peripheral surface of the cylindrical base portion 16Ad1. The outer peripheral surface of the tapered cylindrical portion 6c abuts against and is supported by the inner peripheral surface of the intermediate cylindrical portion 16Ad3. Furthermore, the upper end outer peripheral surface of the large diameter cylindrical portion 6b abuts against and is supported by the inner peripheral surface of the tip cylindrical portion 16Ad2. Therefore, the cup 16A is sandwiched between the lower surface of the boss 4d of the header 4 and the outer peripheral surface of the tapered cylindrical portion 6c of the inner pipe 6, and is held even more stably. This allows the cup 16A to be held in an appropriate position. As shown by the dotted line in FIG. 6, the outer periphery of the holding cylinder 16Ad is shaped so that it gradually expands in diameter as it approaches the top wall 16b (a cross-sectional R-shape), which allows the refrigerant to flow smoothly toward the upper end of the outer pipe 7.

(Second Modification)
Fig. 7 is an enlarged cross-sectional view of the lower end of the inner pipe 6B according to the second modification. In this modification, the outer circumferential surface of the large-diameter cylindrical portion 6Bb has a cylindrical shape up to the lower end 6Bh of the inner pipe 6B, but the large-diameter inner circumferential surface 6Bg gradually expands in diameter from the vicinity of the lower end 6Bh toward the lower end 6Bh, and intersects with the outer circumferential surface of the large-diameter cylindrical portion 6Bb at the lower end 6Bh. In the cross section shown in Fig. 7, the large-diameter inner circumferential surface 6Bg near the lower end 6Bh preferably has an arc shape.

Referring to FIG. 1, in this modified example, when the gas-liquid separated gas-phase refrigerant turns around at the bottom of the outer pipe 7 and flows inward beyond the lower end 6Bh of the inner pipe 6B, it flows along the gradually expanding large-diameter inner circumferential surface 6Bg, ensuring a smooth flow of the refrigerant.

(Third Modification)
Fig. 8 is an enlarged cross-sectional view of the lower end of the inner pipe 6C according to the third modified example. In this modified example, the large-diameter inner circumferential surface 6Cg has a cylindrical shape up to the lower end 6Ch of the inner pipe 6C, but the outer circumferential surface of the large-diameter cylindrical portion 6Cb gradually decreases in diameter from the vicinity of the lower end 6Ch toward the lower end 6Ch, and intersects with the large-diameter inner circumferential surface 6Cg at the lower end 6Ch. In the cross section shown in Fig. 8, the outer circumferential surface of the large-diameter cylindrical portion 6Cb near the lower end 6Ch is preferably arc-shaped.

Referring to FIG. 1, in this modified example, when the gas-phase refrigerant that has been separated into gas and liquid is turned around at the bottom of the outer pipe 7 and flows toward the lower end 6Ch of the inner pipe 6C, it flows along the outer peripheral surface of the gradually reduced diameter large-diameter cylindrical portion 6Cb, ensuring a smooth flow of the refrigerant.

(Fourth Modification)
Fig. 9 is an enlarged cross-sectional view of the lower end of the inner pipe 6D according to the fourth modified example. In this modified example, the large-diameter inner circumferential surface 6Dg gradually expands in diameter from the vicinity of the lower end 6Dh of the inner pipe 6D toward the lower end 6Dh, and the outer circumferential surface of the large-diameter cylindrical portion 6Db gradually decreases in diameter from the vicinity of the lower end 6Dh toward the lower end 6Dh, and the large-diameter inner circumferential surface 6Dg and the outer circumferential surface of the large-diameter cylindrical portion 6Db intersect at the lower end 6Dh. In the cross section shown in Fig. 9, the lower end wall of the large-diameter cylindrical portion 6Cb near the lower end 6Dh preferably has a semicircular arc shape.

Referring to FIG. 1, according to this modified example, when the gas-liquid separated gas-phase refrigerant turns around at the bottom of the outer pipe 7 and heads toward the lower end 6Dh of the inner pipe 6D, it flows along the outer peripheral surface of the gradually narrowing large diameter cylindrical portion 6Db, and when it passes the lower end 6Dh of the inner pipe 6D and flows inward, it flows along the gradually expanding large diameter inner peripheral surface 6Dg, ensuring a smooth flow of the refrigerant.

Second Embodiment
Fig. 10 is a vertical cross-sectional view of an accumulator 1F according to a second embodiment. In the accumulator 1F of this embodiment, the outflow pipe 6F is U-shaped and does not have an outer pipe. Note that Fig. 10 omits a strainer and a bag containing a desiccant. In this embodiment, the configuration of the outflow pipe 6F is different from that of the above-mentioned embodiment, and other configurations are the same as those of the above-mentioned embodiment, so duplicated explanations will be omitted.

The outflow pipe 6F in this embodiment is composed of a small diameter cylindrical section 6Fa and a large diameter U-shaped cylindrical section 6Fb bent into a U shape, connected by a tapered cylindrical section 6Fc. The outer diameter of the small diameter cylindrical section 6Fa is approximately equal to the inner diameter of the small diameter hole 9b. The small diameter cylindrical section 6Fa, the tapered cylindrical section 6Fc, and the upper end of the large diameter U-shaped cylindrical section 6Fb have the same shapes as in the above-mentioned embodiment. The outflow pipe 6F can be formed by drawing the end of a U-shaped pipe.

The outflow pipe 6F has a small diameter inner circumferential surface 6Fe extending inside the small diameter cylindrical portion 6Fa, a tapered inner circumferential surface 6Ff extending inside the tapered tubular portion 6Fc, and a large diameter inner circumferential surface 6Fg extending inside the large diameter U-shaped tubular portion 6Fb. The outflow pipe 6F has a pressure equalizing hole 6Fq in the tapered inner circumferential surface 6Ff, similar to the above-mentioned embodiment.

In this embodiment, after the cup 16 is placed between the header 4 and the outflow pipe 6F, the small diameter cylindrical portion 6Fa of the outflow pipe 6F is inserted into the through hole 16c, and then the small diameter cylindrical portion 6Fa is fixed by press fitting into the small diameter hole 9b of the header 4. As a result, the cup 16 is clamped and fixed between the retaining wall 16d and the lower end of the boss 4d.

In this embodiment, even if the outflow pipe 6F is U-shaped, the outflow pipe 6F can be attached by moving it linearly without rotating it relative to the header 4, so that the free end of the outflow pipe 6F can be positioned inside the cup 16 in the assembly position shown in Figure 10.

Third Embodiment
11 is a vertical cross-sectional view of an accumulator 1G according to the third embodiment. The accumulator 1G of this embodiment is different from the accumulator 1F of the second embodiment in the shape of the outflow pipe 6G. Specifically, the bending radius of the bent portion of the large-diameter U-shaped cylindrical portion 6Gb of the outflow pipe 6G is larger than the bending radius of the corresponding portion of the outflow pipe 6F of the third embodiment. The rest of the configuration is the same as that of the above-mentioned embodiment.

The small diameter cylindrical portion 6Ga, the tapered tube portion 6Gc, and the upper end of the large diameter U-shaped tube portion 6Gb have the same shapes as in the first embodiment. The outflow pipe 6G can be formed by drawing the end of a U-shaped pipe.

The outflow pipe 6G has a small diameter inner circumferential surface 6Ge extending within the small diameter cylindrical portion 6Ga, a tapered inner circumferential surface 6Gf extending within the tapered tubular portion 6Gc, and a large diameter inner circumferential surface 6Gg extending within the large diameter U-shaped tubular portion 6Gb. The outflow pipe 6G has a pressure equalizing hole 6Gq in the tapered inner circumferential surface 6Gf, similar to the above-mentioned embodiment.

(Fourth embodiment)
12 is a vertical cross-sectional view of an accumulator 101 according to the fourth embodiment, with only the left half of the strainer shown in cross section. The accumulator 101 has a tank body 102, a double pipe 105 arranged in the tank body 102, a bag 111 containing a desiccant (moisture absorbent) DA, a cup 116, and a strainer 120. The axis of the inner pipe 106 is designated as L.

The tank body 102 comprises a body 103 and a header 104. The body 103 is formed in a tubular shape with at least an open top end, and as an example, is formed in a bottomed cylindrical shape with an open top end. The header 104 closes the opening at one end of the body 103. The header 104 is joined to the body 103 by circumferential joining, for example via a weld 110, and closes the opening of the body 103. The body 103 and the header 104 are both formed from a metal such as an aluminum alloy. In this specification, the header 104 side is referred to as the upper side, and the bottom side of the body 103 is referred to as the lower side.

For example, the header 104 is formed in a roughly disk shape, and a refrigerant inlet hole 108 and a refrigerant outlet hole 109 are formed penetrating vertically. An inner pipe (also called an outlet pipe) 106 that extends close to the inside bottom of the body 3 is connected to the refrigerant outlet hole 109. An outer pipe 107 is fitted on the outside of the inner pipe 106, thereby forming a double pipe 105.

Below the header 104, a cup 116 is provided as a gas-liquid separating member that separates the mixed refrigerant (a mixture of gas and liquid phase refrigerant) from the refrigerant inlet 108 into high density liquid phase refrigerant and compressor oil (hereinafter referred to as "oil") and low density gas phase refrigerant. The cup 116 is made of, for example, resin. The cup 116 has, for example, a cylindrical shape with a top, and is positioned opposite the refrigerant inlet 108 and the refrigerant outlet 109.

The inner pipe 106 is made of, for example, a metal, and an aluminum alloy is used as one example. The lower end of the inner pipe 106 is open, and the upper end is screwed into the refrigerant outlet hole 109 of the header 104, as described below. The outer periphery of the inner pipe 106 is fitted inside a number of pipe ribs 107a protruding from the inner periphery of the outer pipe 107, so that the inner pipe 106 is stably held within the outer pipe 107 with a gap therebetween.

The outer pipe 107 is made of, for example, synthetic resin, and is attached inside the body 3 with its upper end open. A cylindrical strainer 120 is provided at the bottom of the outer pipe 107. The strainer 120 is composed of a cylindrical case 121 with a bottom made of synthetic resin, and a cylindrical mesh filter 122 that is integrated with the case 121 by insert molding or the like.

A bag 111 containing a desiccant DA is placed between the outer pipe 107 and the inner circumference of the body 103.

The header 104 is made up of a large cylindrical portion 104a and a thin annular portion 104b, which is smaller in diameter than the large cylindrical portion 104a, stacked in series, and a step portion 104c is formed between the large cylindrical portion 104a and the thin annular portion 104b, with which the outer periphery of the upper end of the body 103 engages. The upper surface of the large cylindrical portion 104a is formed, for example, as a plane perpendicular to the vertical direction.

A cylindrical boss 104d is formed on the underside of the header 104, protruding downward from the large cylindrical portion 104a. A refrigerant outlet hole 109 is formed through the boss 104d and penetrating the header 104 from top to bottom, and a refrigerant inlet hole 108 is formed adjacent to the boss 104d and penetrating the header 104 from top to bottom. The underside of the boss 104d is formed, for example, on a plane that is in surface contact with the bottom surface of a cylindrical recess (also called a recess) 116c of the cup 116, which will be described later. The underside of the boss 104d is formed, for example, on a plane that is perpendicular to the axis L of the inner pipe 106.

The refrigerant outlet hole 109 has a large diameter hole 109a formed at the top and a small diameter hole 109b formed at the bottom, and a female thread 109c is formed in the small diameter hole 109b. The inner diameter of the large diameter hole 109a is larger than the thread diameter of the female thread 109c.

The cup 116 of this embodiment can be formed, for example, by press-forming a metal plate. The cup 116 is formed by connecting a side wall 116a and a top wall 116b. A portion of the top wall 116b is plastically deformed so as to shift downward in correspondence with the boss 104d, thereby forming a cylindrical recess 116c. The inner diameter of the cylindrical recess 116c is approximately equal to the outer diameter of the boss 104d. For example, one or more ribs may be formed on the upper surface of the top wall 116b.

A circular hole 116d is formed through the bottom wall of the cylindrical recess 116c. The inner diameter of the circular hole 116d is slightly larger than the inner diameter of the small diameter hole 109b.

The bottom surface of the cylindrical recess 116c of the cup 116 is formed in a plane that is in surface contact with the lower surface of the boss 104d of the header 104. The bottom surface of the cylindrical recess 116c of the cup 116 is formed in a plane that is perpendicular to the axis of the inner pipe 106, for example, in the range where the lower surface of the boss 104d of the header 104 abuts.

The inner pipe 106 is made of a metal pipe of uniform diameter that is expanded near the upper end by bulging, and compressed in the axial direction to form a flange 106a that protrudes radially outward from the entire outer periphery. A male thread 106b is also formed on the outer periphery of the upper end of the inner pipe 106. Note that the method of forming the flange 106a is not limited to bulging. As another example, the flange 106a may be formed by bead processing (string processing).

A pressure equalizing hole 106q is formed below the flange 106a. The pressure equalizing hole 106q penetrates the inside and outside of the inner pipe 106. The pressure equalizing hole 106q is a hole that prevents the liquid phase refrigerant that has accumulated in the inner pipe 106 from being sucked up by the compressor when the compressor is started again after the refrigeration cycle has stopped (after the compressor has stopped operating). In other words, the pressure equalizing hole 106q allows not only the liquid phase refrigerant in the inner pipe 106 but also the gas phase refrigerant outside the inner pipe 106 to be sucked up by the compressor, thereby preventing the liquid phase refrigerant from being sucked up.

The inner pipe 106 may have a flat surface at its lower end perpendicular to the axis L, as in the embodiment shown in FIG. 4, or the inner diameter surface may expand as it approaches the lower end, as in the embodiment shown in FIG. 7, the outer diameter surface may decrease as it approaches the lower end, as in the embodiment shown in FIG. 8, or the inner diameter surface may expand and the outer diameter surface may decrease as it approaches the lower end, as in the embodiment shown in FIG. 9.

An example of the work of assembling the header 104, cup 116, and inner pipe 106 will be described. First, the boss 104d of the header 104 is inserted into the cylindrical recess 116c of the cup 116, and the lower end of the boss 104d is brought into contact with the bottom surface of the cylindrical recess 116c. This causes the small diameter hole 109b and the circular hole 116d to be coaxially aligned.

Then, the inner pipe 106 is brought close to the cup 116 from below. The upper end of the inner pipe 106 is then inserted into the circular hole 116d, and the male thread 106b is screwed into the female thread 109c of the small diameter hole 109b of the header 104.

As the male thread 106b is screwed into the female thread 109c, the flange 106a approaches the header 4 and comes into contact with the underside of the cylindrical recess 116c. At this time, the inner pipe 106 is locked with the cup 116 sandwiched between it and does not approach any further toward the header 104. In this state, the cup 116 is sandwiched between the underside of the boss 104d of the header 104 and the flange 106a of the inner pipe 106 and is held stably. This allows the cup 116 to be held in an appropriate position.

The outer pipe 107 and strainer 120 are attached to the inner pipe 106 of the assembly formed in this manner, and the assembly is installed inside the body 103 in which the bag 111 is arranged, and then welded to the header 104 to complete the accumulator 101.

In this embodiment, the inner pipe 106 is fixed to the header 104 by screwing the male thread 106a into the female thread 109c of the small diameter hole 109b, which means that, for example, crimping of the inner pipe 106 is not necessary (no crimping portion is provided inside the refrigerant outflow hole 109). This means that there is no need to insert a crimping tool into the refrigerant outflow hole 109, and there is also no need to expand the diameter of the end of the inner pipe 106 by plastic deformation to engage with the step inside the refrigerant outflow hole 109.

(Accumulator operation)
The operation of the accumulator 101 configured as above will be described with reference to Fig. 12. In the following description, an example will be described in which the accumulator 101 is disposed between the evaporator and compressor of a refrigeration cycle, moisture contained in the refrigerant from the evaporator is removed to generate gas refrigerant, and the gas refrigerant is returned to the compressor.

When the refrigerant is discharged from the evaporator, it is transported to the accumulator 101 through a connecting pipe (not shown). After reaching the accumulator 101, the refrigerant flows into the body 103 through the refrigerant inlet hole 108, and then collides with the upper surface of the cup 116, where it is separated into high-density liquid-phase refrigerant and oil, and low-density gas-phase refrigerant (gas refrigerant).

After gas-liquid separation, the liquid refrigerant and oil are stored in the body 103 due to their own weight. During this process, the liquid refrigerant and oil continue to separate, and the oil accumulates below the liquid refrigerant. At this time, the liquid level of the liquid refrigerant reaches a height position where part of the desiccant-containing bag 111 is immersed. Therefore, both the moisture contained in the liquid refrigerant and the humidity contained in the gas refrigerant are absorbed by the desiccant DA.

Meanwhile, the gas-phase refrigerant that has been separated into gas and liquid flows in from the upper end opening of the outer pipe 107 and flows down inside the outer pipe 107. It then turns around at the bottom of the outer pipe 107 and flows inside beyond the lower end of the inner pipe 106, then rises inside the inner pipe 106 and is led to the refrigerant outflow hole 109.

Oil that accumulates at the bottom of the body 103 together with the liquid refrigerant moves to the bottom side of the body 103 due to differences in specific gravity and properties compared to the liquid refrigerant, and is sucked into the gas refrigerant that is sucked into the compressor suction side, passing through the mesh filter 122 of the strainer 120, the oil return hole 107e, and the internal space of the inner pipe 106, in that order, before being returned to the compressor suction side together with the gas refrigerant and circulated. As it passes through the mesh filter 122, foreign matter such as sludge is captured and removed from the circulating refrigerant (including oil).

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the present invention. For example, in the first embodiment, the upper end of the inner pipe 6 is fixed to the small diameter hole 9c by press fitting, but the upper end of the inner pipe 6 may be expanded and fixed to the small diameter hole 9c.

In the above embodiment, the inner pipe 6 and the

outflow pipes

6F, 6G are formed in a cylindrical shape with a circular cross-sectional shape perpendicular to their respective axes, but the cross-sectional shape may be a shape other than a circle. Other examples will be described using the inner pipe 6 as a specific example. The inner pipe 6 has a large diameter cylindrical portion 6b, a small diameter cylindrical portion 6a, and a tapered cylindrical portion 6c, and the cross-sectional shape of each is a circle. The large diameter cylindrical portion 6b, the small diameter cylindrical portion 6a, and the tapered cylindrical portion 6c of the inner pipe 6 are not limited to having a circular cross-sectional shape. It is sufficient that the cross-sectional area of the small diameter cylindrical portion 6a is smaller than that of the large diameter cylindrical portion, and the cross-sectional area of the tapered cylindrical portion 6c is gradually smaller toward the small diameter cylindrical portion 6a. For example, it is preferable that the cross-sectional shapes of the small diameter cylindrical portion 6a, the tapered cylindrical portion 6c, and the large diameter cylindrical portion 6b are similar to each other. As another example, the large diameter cylindrical portion 6b, the small diameter cylindrical portion 6a, and the tapered tube portion 6c may be cylindrical with a rectangular cross section. The same applies to the

outflow pipes

6F and 6G.

In the above-mentioned embodiment and modified example, the extending portion is described as a retaining wall 16 and a retaining cylinder 16A formed in a shape corresponding to the outer shape of the inner pipe 6. In another example, the extending portion may have a shape in which at least the intermediate portions 16d3, 16Ad3 abut against the tapered cylindrical portion 6c of the inner pipe 6. In a preferred embodiment, the extending portion is formed in a shape that abuts against at least one of the small cylindrical portion 6e and the large diameter cylindrical portion 6b in addition to the tapered cylindrical portion 6c. In an even more preferred embodiment, the extending portion has a shape corresponding to the outer shape of the inner pipe 6, like the retaining wall 16 and the retaining cylinder 16A.

In the second embodiment, the annular retaining cylinder 16A is described as one example of an extension portion, but the retaining cylinder 16A is not limited to being formed in a continuous annular shape. For example, the retaining cylinder 16A may be formed in a C-shape in a plan view. Also, the retaining cylinder 16A has an outer shape formed in a cylindrical shape, but is not limited to a cylindrical shape. In another example, the outer shape may be a polygonal prism, such as a square prism.

In the above embodiment, the inner circumferential surfaces of the inner pipe 6 and the

outflow pipes

6F, 6G have been described as having a circular cross section perpendicular to their respective axes, but the cross section of the inner circumferential surfaces may be other than a circle. Other examples will be described using the inner pipe 6 as a specific example. The inner pipe 6 has a large diameter inner circumferential surface 6g, a small diameter inner circumferential surface 6e, and a tapered inner circumferential surface 6f, and each cross section perpendicular to its axis is a circle, but this is not limited to this. The inner circumferential surface of the inner pipe 6 may have a shape such that the cross-sectional area perpendicular to the axis of the small diameter inner circumferential surface 6e is smaller than the cross-sectional area perpendicular to the axis of the large diameter inner circumferential surface 6g, and the cross-sectional area perpendicular to the axis of the tapered inner circumferential surface 6f gradually decreases toward the small diameter inner circumferential surface 6e. For example, it is preferable that the shapes of the cross sections perpendicular to the axes of the small diameter inner circumferential surface 6e, the tapered surface 6f, and the large diameter inner circumferential surface 6g are similar to each other. In another example, the inner peripheral surface of the inner pipe 6 may have a rectangular cross section perpendicular to the axis. The same applies to the

outflow pipes

6F and 6G.

In the above embodiment, the inner pipe 6 and the

outflow pipes

6F, 6G are formed by drawing, but they may be formed by a processing method other than drawing. In another example, the inner pipe 6 and the

outflow pipes

6F, 6G may be formed by performing pipe expansion processing on the pipes.

In the above embodiment, an example was described in which the inner surface of the retaining wall 16d was formed as a curved surface, but in other examples, it may be formed as a flat surface. Even if the inner surface of the intermediate portion 16d3 is formed as a flat surface, the intermediate portion 16d3 abuts against the tapered tubular portions of the inner pipe 6 and the

outflow pipes

6F, 6G, thereby obtaining the same effect as described above. If the inner surface of the tip portion 16d2 is formed as a flat surface, the inner surface of the tip portion 16d2 is formed as a flat surface that abuts against the large diameter cylindrical portion 6b of the inner pipe 6 and the large diameter U-shaped tubular portion 6Fb of the

outflow pipes

6F, 6G, thereby obtaining the same effect as described above.

In the above-described embodiment and modified examples, the

cups

16, 116 are one example of a gas-liquid separating member. The gas-liquid separating member faces both the refrigerant inlet holes 8, 108 and the refrigerant outlet holes 9, 109. The gas-liquid separating member has a portion with which the refrigerant flowing in from the refrigerant inlet holes 8, 108 collides. The gas-liquid separating member preferably faces the entire area of the refrigerant inlet holes 8, 108. The facing direction is the axial direction of the refrigerant inlet holes 8, 108.
The gas-liquid separation member preferably has a top wall facing both the entire refrigerant inlet holes 8, 108 and the refrigerant outlet holes 9, 109, and a cylindrical side wall facing the inner circumferential surface of the

body

3, 103.
Preferably, the gap between the

header

4, 104 and the top wall and the gap between the inner circumferential surface of the

body

3, 103 and the side wall are approximately the same. Here, approximately the same means that in addition to being completely the same, it may include an error. That is, when the refrigerant flowing in from the

refrigerant inlet hole

8, 108 collides with the top wall and flows downstream, it flows through the gap between the top wall and the

header

4, 104 and the gap between the inner circumferential surface of the

body

3, 103 and the side wall. If these gaps are "the same", the smooth flow of the refrigerant is maintained. In addition, if there is a small error in these gaps, the state in which the refrigerant flows smoothly can be maintained. The error is an error that can maintain the flow of the refrigerant smoothly in this way.
The top wall of the gas-liquid separating member is not limited to being in the form of a plate having a constant thickness.
Furthermore, another example of the gas-liquid separating member has a structure that does not include a side wall.

This specification includes the disclosure of the following inventions.
(First aspect)
a body portion having an opening at at least one end;
a header having a refrigerant inlet and a refrigerant outlet and closing one end of the body portion;
a gas-liquid separating member accommodated in the body portion, the gas-liquid separating member having a communication portion formed in a portion facing the refrigerant outflow hole, the communication portion communicating the header side with an opposite side;
an outflow pipe that is accommodated in the body portion, a portion of which is disposed in the communication portion, and which is connected to the refrigerant outflow hole,
the outflow pipe has a small cylinder portion inserted into and fixed to the refrigerant outflow hole, a large cylinder portion disposed within the body portion and having a cross-sectional area larger than that of the small cylinder portion, and a tapered cylinder portion connecting the small cylinder portion and the large cylinder portion,
The inner circumferential surface of the outflow pipe has, along a flow direction of the refrigerant, a large inner circumferential surface, an intermediate inner circumferential surface connected to the large inner circumferential surface, and a small inner circumferential surface connected to the intermediate inner circumferential surface and having a cross-sectional area smaller than that of the large inner circumferential surface, and the cross-sectional area of the intermediate inner circumferential surface is gradually reduced toward the small inner circumferential surface,
the gas-liquid separating member has the communicating portion, and includes a main body facing the header, and an extension portion extending from the main body to the tapered cylindrical portion, and is sandwiched between the header and the outflow pipe with the extension portion abutting against the tapered cylindrical portion.
1. An accumulator comprising:

(Second Aspect)
The outflow pipe is formed into a cylindrical shape having a circular cross-sectional shape.
12. The accumulator of claim 1,

(Third Aspect)
The extension portion abuts against an outer circumferential surface of the large cylinder portion.
The accumulator according to the first or second aspect,

(Fourth aspect)
The extension portion is provided in a plurality of portions in a circumferential direction of the outflow pipe.
The accumulator according to any one of the first to third aspects, characterized in that

(Fifth aspect)
The extension portion is formed in a cylindrical shape so as to abut on the tapered cylindrical portion over the entire circumference.
The accumulator according to any one of the first to fourth aspects,

(Sixth Aspect)
an outer pipe that is formed in a cylindrical shape and is accommodated in the body portion with the outflow pipe disposed inside, the outer pipe having an open end on the gas-liquid separating member side;
the extension portion has a guide portion that guides the refrigerant outside the outer pipe to an opening of the outer pipe on the gas-liquid separating member side, the guide portion being formed by an outer circumferential surface of the extension portion and having a shape that increases in diameter as it approaches the gas-liquid separating member side.
5. The accumulator of claim 4,

(Seventh aspect)
The outflow pipe is formed by drawing or expanding the pipe.
The accumulator according to a second aspect,

(Eighth aspect)
The outflow pipe is press-fitted into the refrigerant outflow hole.
The accumulator according to any one of the first to seventh aspects,

(Ninth aspect)
A male thread formed on the outflow pipe and a female thread formed on the refrigerant outflow hole are screwed together.
The accumulator according to any one of the first to eighth aspects,

(Tenth Aspect)
A header having a refrigerant outlet hole;
an outflow pipe connected to the refrigerant outflow hole;
a gas-liquid separating member disposed opposite the header and having a communication portion through which a portion of the outflow pipe is disposed;
A method for manufacturing an accumulator having the following features:
forming the outflow pipe having a small cylindrical portion, a large cylindrical portion having a cross-sectional area larger than that of the small cylindrical portion, and a tapered cylindrical portion connecting the small cylindrical portion and the large cylindrical portion by subjecting the pipe to a drawing process or a tube expansion process;
an extension portion is formed on a main body portion of the gas-liquid separating member, the main body portion being a portion that faces the header, the extension portion extending in a direction away from the main body portion;
With the small cylinder portion of the outflow pipe disposed in the communication portion, the extension portion and the tapered cylinder portion are brought close to each other so that the extension portion abuts against the tapered cylinder portion;
a small cylindrical portion fixed to the refrigerant outflow hole of the header and an extension portion abutting the tapered cylindrical portion, thereby sandwiching the gas-liquid separation member between the header and the outflow pipe.

(Eleventh aspect)
a body portion having an opening at at least one end;
a header having a refrigerant inlet and a refrigerant outlet and closing one end of the body portion;
an outflow pipe housed in the body portion and connected to the refrigerant outflow hole,
The outlet pipe has a male thread formed at an end thereof,
The refrigerant outlet hole has a female thread,
The outflow pipe is attached to the header by threading the male thread into the female thread.
1. An accumulator comprising:

(Twelfth Aspect)
a gas-liquid separating member accommodated in the body portion, the gas-liquid separating member having a communication portion formed in a portion facing the refrigerant outflow hole, the communication portion communicating the header side with the opposite side;
The outflow pipe has a flange portion protruding radially outward from an outer circumferential surface in the vicinity of the male thread,
a portion of the outflow pipe is disposed in the communication portion,
The gas-liquid separating member is held between the flange portion and the header in a state in which the outflow pipe is attached to the header.
The accumulator according to an eleventh aspect,

(Thirteenth aspect)
The header has a boss portion around the refrigerant outlet hole,
the gas-liquid separating member has a recess that fits into the boss portion,
When the outflow pipe is attached to the header, a bottom wall of the recess is held between the flange portion and the boss portion.
The accumulator according to the eleventh or twelfth aspect,

(Fourteenth aspect)
The gas-liquid separation member is formed by press-molding a metal plate material.
14. The accumulator according to any one of the eleventh to thirteenth aspects,

1, 101

Accumulator

2, 102

Tank body

3, 103

Body

4, 104

Header

5, 105

Double pipe

6, 6B, 6C, 6D, 106 Inner pipe (outlet pipe)
6F, 6G U-shaped outflow pipe 6a, 6Fa, 6Ga Small diameter cylindrical portion 6b Large diameter cylindrical portion 6c, 6Fc, 6Gc Tapered tube portion

106a Flange portion

7, 107

Outer pipe

8, 108

Refrigerant inlet hole

9, 109

Refrigerant outlet hole

11, 111

Bag

20, 120

Strainer

21, 121

Case

22, 122 Mesh filter

Claims

a body portion having an opening at at least one end;
a header having a refrigerant inlet and a refrigerant outlet and closing one end of the body portion;
a gas-liquid separating member accommodated in the body portion, the gas-liquid separating member having a communication portion formed in a portion facing the refrigerant outflow hole, the communication portion communicating the header side with an opposite side;
an outflow pipe that is accommodated in the body portion, a portion of which is disposed in the communication portion, and which is connected to the refrigerant outflow hole,
the outflow pipe has a small cylinder portion inserted into and fixed to the refrigerant outflow hole, a large cylinder portion disposed within the body portion and having a cross-sectional area larger than that of the small cylinder portion, and a tapered cylinder portion connecting the small cylinder portion and the large cylinder portion,
The inner circumferential surface of the outflow pipe has, along a flow direction of the refrigerant, a large inner circumferential surface, an intermediate inner circumferential surface connected to the large inner circumferential surface, and a small inner circumferential surface connected to the intermediate inner circumferential surface and having a cross-sectional area smaller than that of the large inner circumferential surface, and the cross-sectional area of the intermediate inner circumferential surface is gradually reduced toward the small inner circumferential surface,
the gas-liquid separating member has the communicating portion, and includes a main body facing the header, and an extension portion extending from the main body to the tapered cylindrical portion, and is sandwiched between the header and the outflow pipe with the extension portion abutting against the tapered cylindrical portion;
1. An accumulator comprising:
The outflow pipe is formed into a cylindrical shape having a circular cross-sectional shape.
2. The accumulator of claim 1 .
The extension portion abuts against an outer circumferential surface of the large cylinder portion.
2. The accumulator of claim 1 .
The extension portion is provided in a plurality of portions in a circumferential direction of the outflow pipe.
2. The accumulator of claim 1 .
The extension portion is formed in a cylindrical shape so as to abut on the tapered cylindrical portion over the entire circumference.
2. The accumulator of claim 1 .
an outer pipe that is formed in a cylindrical shape and is accommodated in the body portion with the outflow pipe disposed inside, the outer pipe having an open end on the gas-liquid separating member side;
the extension portion has a guide portion that guides the refrigerant outside the outer pipe to an opening of the outer pipe on the gas-liquid separating member side, the guide portion being formed by an outer circumferential surface of the extension portion and having a shape that increases in diameter as it approaches the gas-liquid separating member side.
6. The accumulator according to claim 5.
The outflow pipe is formed by drawing or expanding the pipe.
3. The accumulator according to claim 2.
The outflow pipe is press-fitted into the refrigerant outflow hole.
2. The accumulator of claim 1 .
A male thread formed on the outflow pipe and a female thread formed on the refrigerant outflow hole are screwed together.
2. The accumulator of claim 1 .
A header having a refrigerant outlet hole;
an outflow pipe connected to the refrigerant outflow hole;
a gas-liquid separating member disposed opposite the header and having a communication portion through which a portion of the outflow pipe is disposed;
A method for manufacturing an accumulator having the following features:
forming the outflow pipe having a small cylindrical portion, a large cylindrical portion having a cross-sectional area larger than that of the small cylindrical portion, and a tapered cylindrical portion connecting the small cylindrical portion and the large cylindrical portion by subjecting the pipe to a drawing process or a tube expansion process;
an extension portion is formed on a main body portion of the gas-liquid separating member, the main body portion being a portion that faces the header, the extension portion extending in a direction away from the main body portion;
With the small cylinder portion of the outflow pipe disposed in the communication portion, the extension portion and the tapered cylinder portion are brought close to each other so that the extension portion abuts against the tapered cylinder portion;
a small cylindrical portion fixed to the refrigerant outflow hole of the header and an extension portion abutting the tapered cylindrical portion, thereby sandwiching the gas-liquid separation member between the header and the outflow pipe.