JPH07104077B2 - Evaporator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a refrigeration evaporator (evaporator) in which a box-type expansion valve is installed so as to bridge between a refrigerant inlet and outlet pipes. ) Concerning.

[Prior Art] FIGS. 7 to 9 show an example of the structure of the conventional evaporator described above. FIG. 7 is an external view, and FIGS. 8 and 9 are a plan view of a tube plate and a side cross-sectional view of the flat tube which constitute the flat tube as a component of the evaporator.

The flat tube A is manufactured by bonding two tube plates 1 each having a shallow tray shape as shown in the drawing, which are formed by pressing an aluminum plate, by a brazing method. At the upper end of the tube plate 1, an inlet tank portion 1A and an outlet tank portion 1B, which serve as an inlet port and an outlet port of the refrigerant, and a jetty-shaped partition wall 1E at the central portion, are provided so as to form a flat pipe. In A, a U-turn-shaped coolant flow path C connecting these tank parts is formed.

When a plurality of flat tubes A having such a structure are combined in a laminated manner by a brazing method as shown in FIG. 5, an inlet hole 1C formed in the refrigerant inlet port 1A of each flat tube A
Are connected to each other to form a refrigerant distribution path E, and the outlet holes 1D formed in the refrigerant outlet port 18 are also connected to each other to form a refrigerant collecting path F (see FIGS. 8 and 9). 1F is a group of ribs for reinforcing the flat tube A and forming a maze.

At a suitable location of each of the refrigerant distribution path E and the collecting path F, a specific flat pipe A2 or A3 is provided based on a positional relationship in which the refrigerant inlet pipe 2 and the refrigerant inlet pipe 3 are adjacent and parallel to each other.
It is built into one. Since a heat exchange space B corresponding to the thickness of the tank portion is formed between the adjacent flat tubes A, the corrugated fins 15 are inserted in the space.

In the method of assembling the evaporator having the above-described structure, the brazing material is clad on both surfaces of the tube plate 1 in advance, and the corrugated fins 15 and the plate-like joint member 5 are also stacked in the state shown in FIG. The heat exchange unit 100 is temporarily assembled by fitting or fitting. This state is fastened and fixed using a jig and then heated in a brazing furnace, whereby the main assembly is completed extremely efficiently.

[Problems to be Solved by the Invention] As a method of connecting an expansion valve called a box type to the refrigerant inlet pipe 2 and the outlet pipe 3 of the evaporator having the above-described structure, for example, as a connection method explanatory diagram, As shown in FIG. 6, a plate-like joint member 5 is used, in which an outlet hole 6 and an inlet hole 7 for the refrigerant are drilled, and the seats for the pipes 2 and 3 are provided at the rim portion thereof. Such a method can be considered as one tentative plan.

At the bottom surface of the plate-like joint member 5, the refrigerant outlet and inlet holes 6 are formed.
Short tubular joint portions 5D and 5E are provided so as to extend the lower end rim portions of and 7, and a fitting groove 5C of the O-ring 11 is formed on the outer periphery of each by a cutting method.

To connect the box-type expansion valve 200 to the evaporator, the refrigerant outlet 21 and the refrigerant inlet 22 of the expansion valve 200 are fitted with the joint portions 5D and 5E of the plate-shaped joint member 5, respectively. Then, the refrigerant inlet pipe 2 and the outlet pipe 3 of the evaporator are respectively fitted into the pipe fitting seats provided on the upper surface of the joint member 5 and then brazed to hermetically seal the refrigerant outlet and inlet holes 6 and 7. Connect them. a indicates a brazing point.

However, according to such an expansion valve connecting method, since the plate-like joint member 5 made of a thick metal plate has a considerably large heat capacity, brazing joining with the pipes 2 and 3 may be insufficient. Extremely high If a joint failure occurs, a very inefficient repair work is required.

Further, the step of providing the fitting groove 5C of the gasket in the joint portions 5D and 5E of the plate-shaped joint member 5 by the cutting method also becomes a great obstacle to the improvement of productivity.

It is an object of the present invention to provide an evaporator having a structure in which an expansion valve can be attached while maintaining a hermetic seal more efficiently and more reliably.

[Means for Solving the Problems] In order to achieve the above object, the evaporator according to the present invention includes a flat tube group having a refrigerant inlet / outlet for communicating the refrigerant inlet and outlet of each tube with each other Under the condition that fins are interposed in the heat exchange space between the tubes, the heat exchange unit that is laminated and integrated is provided with a refrigerant inlet pipe and an outlet pipe, and the two pipes that are adjacent and parallel to each other are free. Connect the ends to the refrigerant outlet and inlet of each expansion valve,
In an evaporator manufactured by brazing, an inlet side pipe joint that has a circumferential bulging portion on one end side and connects the inlet pipe of the refrigerant and the refrigerant outlet of the expansion valve, and a circumferential shape on one end side An outlet side pipe joint including a bulging portion, which communicates the outlet pipe of the refrigerant with the refrigerant inlet of the expansion valve, and an inlet side pipe joint of the refrigerant and an outlet side pipe joint, respectively, for pipe insertion A plate-like joint member provided with a hole, the inlet side pipe joint of the refrigerant and the outlet side pipe joint, under the state of fitting the one end side of each of the refrigerant inlet and refrigerant outlet of the expansion valve, An inlet for the refrigerant, comprising: a fastening means for press-contacting the plate-like joint member with the refrigerant outlet and the inlet forming surface of the expansion valve via an O-ring along the circumferential bulge. Side and outlet side pipe fittings End side has adopted the configuration that are respectively crimped to the free ends of the inlet and outlet pipes of the refrigerant.

The above-mentioned caulked portion is hermetically sealed by a brazing material during brazing and assembling of the heat exchange unit.

[Operation] The evaporator having the above-mentioned configuration is a relay joint member for connecting the free ends of the refrigerant inlet pipe and outlet pipe provided in the heat exchange unit to the refrigerant inlet and outlet of the expansion valve. A plate-shaped joint member, a refrigerant inlet side pipe joint and an outlet side pipe joint are prepared.

The inlet side pipe joint of the refrigerant inserted through the pipe insertion hole of the plate-like joint member, and each one end side of the outlet side pipe joint,
When the fastening means is actuated and the plate-shaped joint member is pressed against the refrigerant inlet / outlet forming surface of the expansion valve, the circumferential bulging portions of both pipe joints and the O-ring along the bulging portion are separated. , By being pressed between the plate-shaped joint member and the expansion valve,
It is firmly and airtightly connected and fixed to the refrigerant outlet or inlet.

The other end of each of the refrigerant inlet side and outlet side pipe joints is securely joined by fitting into the refrigerant inlet pipe or outlet pipe of the heat exchange unit and caulking.
Then, it is hermetically sealed in the later brazing process.

EFFECTS OF THE INVENTION (a) Since it is not necessary to braze the plate-like joint member, the problem that the brazing work becomes difficult due to the excessive heat capacity of the member is solved.

(B) Since it is not necessary to provide a cutting groove for fitting the O-ring on the plate-like joint member, the structure of this member can be simplified.

(C) The fixed positioning of the refrigerant inlet side pipe joint and the outlet side pipe joint can be easily and accurately performed by inserting both joints into the plate-shaped joint member.

[Embodiment] The configuration of the present invention will be specifically described below based on an embodiment shown in the drawings.

FIG. 1 and FIG. 2 show an evaporator for installation in an air conditioner for automobiles as one embodiment according to the invention,
The attachment structure of the refrigerant inlet pipe and the outlet pipe to the heat exchange unit, and the attachment structure of the expansion valve to the free ends of these pipes are illustrated as exploded views, respectively.

The evaporator of this embodiment basically has the same structure as that of the conventional evaporator shown in FIG. 5 to FIG. 8 except for the portion where the refrigerant inlet and outlet pipes are attached to the expansion valve. Therefore, the description will be made below with reference to these figures.

The tube plate 1 that constitutes the flat tube A is formed by plastically working a material plate in which an A4003 grade aluminum plate is clad with A4004 grade brazing material in advance on both sides.
As mentioned above, it is shaped so as to obtain a shallow basin.

Then, as shown in FIG. 1, the specific flat tubes A2 and A3 for mounting the refrigerant inlet pipe 2 or the outlet pipe 3 are provided at the upper end portions of the two tube plates 1 constituting these flat tubes. A semi-cylindrical bulge forming each half of the refrigerant inlet pipe 2 or the refrigerant outlet pipe 3 is formed integrally with the tube plate 1. Therefore, flat tubes 2A and 3A made by bonding two such tube plates 1 together
Are respectively the inlet pipe 2 and the outlet pipe 3 of the refrigerant.
Is built in. Although not clearly shown in this figure, the refrigerant inlet pipe 2 is connected to the refrigerant inlet tank portion 1A of the flat tube A2, and the refrigerant outlet pipe 3 is connected to the refrigerant outlet tank portion 1B of the flat tube A3. Has been given. The inlet pipe 2 and the outlet pipe 3 for the refrigerant are bent at their tips into an L shape for convenience of connection to the expansion valve 200.

The expansion valve 200 is of a type called a box type, and a refrigerant outward path pipe 31 and a return path pipe 32 have a joint member on the bottom surface of the valve box 20 made of metal and having a rectangular parallelepiped shape.
Connected using 33 and 34. Further, on the top surface of the valve box 20, there are provided a refrigerant outlet 21 provided with a seat 21A of the refrigerant outlet side pipe joint 9 and a refrigerant inlet 22 provided with a seat 22A of the refrigerant inlet side pipe joint 10. There is. Reference numeral 24 is a diaphragm chamber containing a diaphragm that is displaced between the refrigerant outlet 21 and the inlet 22 according to the degree of superheat of the refrigerant. Although illustration of the internal structure of the valve box 20 is omitted, a valve body and a valve body for increasing or decreasing the refrigerant flow rate at the refrigerant outlet 21 in accordance with the degree of superheat of the refrigerant at the refrigerant inlet 22 are provided in the valve box. A valve seat and a valve rod for transmitting the movement of the diaphragm to the valve body are incorporated.

The inlet side pipe fitting 9 and the outlet side pipe fitting 10 for the refrigerant have the same shape, and a pipe made of A3003 grade aluminum or the like is subjected to plastic working and is shown in FIG. 1 and FIG. The shape is given.

That is, on one end side (the lower end side in the figure) of these joints,
Circumferentially bulged portion that receives the O-ring 11 as a gasket
9A or 10A is formed by the bulging method, and the other end side is provided with an enlarged diameter portion 9B or 10B for fitting the inlet pipe 2 or the outlet pipe 3 of the refrigerant for caulking. The expanded diameter portion is formed by first inserting the pipe joint at the stage of finishing the bulge processing into the pipe insertion holes 6 and 7 provided in the plate-like joint member 5 as shown in FIG. After doing. Therefore, after forming the expanded diameter portion, the plate-like joint member 5 and the pipe joints 9 and 10 are integrated, and the benefit that the subsequent assembling work can be efficiently performed is obtained.

The plate-like joint member 5 is provided with an expansion valve at one end side of the pipe joints 9 and 10.
The refrigerant outlet 21 and the refrigerant inlet 22 of 200 are respectively airtightly joined and fixed. Therefore, on the top surface of the valve box 20, there are screwed screw holes 23 of the fastening bolts 25 as fastening means for fastening the plate-shaped joint member 5 to this top surface.
Is provided in one or more.

FIG. 5 shows that a box type expansion valve 200 is attached to the heat exchange unit 100, and the expansion valve 200 further has a refrigerant outward pipe 31 and a return pipe 32.
It is the sketch which showed the state which is going to connect. Reference numeral 16 in the drawing denotes side plates for protecting both side ends of the heat exchange unit 100.

As described above, the method of assembling the evaporator is such that a plurality of flat tubes A as a superposed body of two ordinary tube plates 1 and the refrigerant inlet pipe 2 or outlet pipe 3 are integrally formed. The specific flat tubes A2 and A3, which are composed of a superposition of two specific tube plates, are
After stacking under the arrangement shown in the figure, the side plates 16 are applied to both side ends of this stacked body, and this temporary assembled state is fastened and fixed using a jig.

Next, at each free end of the refrigerant inlet pipe 2 and the outlet pipe 3, the expanded diameter portion 9B of the refrigerant inlet pipe joint 9 or the outlet pipe joint 10 integrated with the plate-like joint member 5 is formed.
The expanded diameter portion 10B of is fitted. Then, the pipe and the pipe joint are firmly joined by caulking the expanded diameter portions.

Then, the temporary assembly is placed in a brazing furnace and heated to the melting temperature of the brazing filler metal so that the adjacent corrugated fins 15 and the corrugated fins 15 and the side plates 16 are separated from each other. The main assembly of the heat exchange unit 100 is completed extremely efficiently by brazing and joining the spaces.

At the same time, the refrigerant inlet pipe 2 and the refrigerant outlet side pipe joint 9
The fitting gap between and the fitting gap between the pipe 3 and the pipe joint 10 are also brazed, so that the fitting portion is joined more firmly and securely in a hermetically sealed state.

In order to assemble the box-type expansion valve 200 to the evaporator to which the plate-like joint member 5 is attached, the pipe joints 9 and 10 fitted in the plate-like joint member 5 are shown in FIG. After fitting the O-ring 11 as described above, the lower ends of the O-ring 11 are inserted into the refrigerant outlet 21 and the inlet 22 of the valve box 20, and the plate-like joint member 5 is fastened to the top surface of the valve box 20 by the fastening bolts 25. Good.

As described above, the refrigerant outward pipe 31 and the return pipe 32 are connected to the bottom of the valve box 20.

3 and 4 show an evaporator according to a second embodiment of the present invention.

The difference from the first embodiment is that the refrigerant inlet pipe 2 and the refrigerant inlet pipe 3 formed integrally with the specific flat tubes A2 and A3 are
Both are extremely short straight pipes, and these short inlet pipe 2 or outlet pipe 3 and refrigerant outlet joint 9 or inlet joint 10
, And an L-shaped second pipe joint 2A or 3A is interposed as a middle joint.

Therefore, when press-molding the tube plate 1 forming the specific flat tubes A2 and A3, effects such as reduction of material loss can be obtained.

Further, in this embodiment, the refrigerant inlet side and outlet side joints 9 and
Instead of providing the expanded diameter portion at 10, the expanded diameter portions 2C and 2D are provided at the lower end sides of the second pipe joints 2A and 3A.

The heat exchange unit 100 and the expansion valve 200 shown in the above embodiment
The shape and structure of the above are merely disclosed as one specific example, and for example, the flat tube A that constitutes the heat exchange unit 100.
Design items such as which one of the groups is selected as the specific flat tubes A2 and A3 or how the plate-like joint member 5 and the valve box 20 are fastened are appropriately selected as necessary. Even if changed, the object of the present invention can be achieved.

Further, in the present embodiment, the type in which the tank exists only on one side of the upper end has been described, but the present invention can be applied to a type having two tanks at the upper and lower ends.

[Brief description of drawings]

FIG. 1 and FIG. 2 are diagrams of the first embodiment of the present invention, and show exploded structures of the expansion valve mounting structure to the refrigerant inlet and outlet pipes of the evaporator, respectively. FIG. 3 and FIG. 4 are exploded explanatory views similar to the above regarding the second embodiment of the present invention. FIG. 5 is a sketch drawing showing how the expansion valve is attached to the evaporator. FIG. 6 is an explanatory view of a mounting structure showing one method of mounting the expansion valve on the evaporator. 7 to 9 are views relating to a conventional evaporator, FIG. 7 is an external view, FIG. 8 is a plan view of a tube plate, and FIG. 9 is a side sectional view of a flat tube. In the figure, 1 ... Tube plate, 1A, 1B ... Refrigerant inlet and outlet, 2, 3 ... Refrigerant inlet and outlet pipe, 5 ... Plate joint member, 5A, 5B ... Receptacle, 6, 7 ...... Pipe insertion holes, 9, 10 ...... Refrigerant inlet and outlet pipe joints,
9A, 10A ... Flange-shaped bulge, 9B, 10B ...
11 ... O-ring, 21,22 ... expansion valve refrigerant outlet and inlet, 25 ... fastening means, A ... flat tube, B ... heat exchange gap

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Kojima 1-1-1, Showa-machi, Kariya city, Aichi prefecture, Nihon Denso Co., Ltd. (56) References JP-A-59-225702 (JP, A) -87477 (JP, U) Actually opened 63-7723 (JP, U) Actually opened 60-82170 (JP, U)

Claims (1)

[Claims] 1. A flat tube group having a refrigerant inlet / outlet is communicated with the refrigerant inlet and outlet of each tube, and fins are interposed in a heat exchange space between adjacent flat tubes. The heat exchange units that are stacked and combined are provided with an inlet pipe and an outlet pipe for the refrigerant, and the free ends of the two pipes that are adjacent and juxtaposed are connected to the refrigerant outlet and inlet of each expansion valve and brazed. In the manufactured evaporator, an inlet side pipe joint is provided which has a circumferential bulging portion on one end side and which communicates the inlet pipe of the refrigerant with the refrigerant outlet of the expansion valve, and a circumferential bulging portion on the one end side. An outlet side pipe joint for communicating the outlet pipe of the refrigerant with the refrigerant inlet of the expansion valve, and a pipe insertion hole for inserting the refrigerant inlet side pipe joint and the outlet side pipe joint, respectively, are provided. A plate-shaped joint member, Under the condition that the one end side of each of the inlet side pipe joint and the outlet side pipe joint of the refrigerant is fitted to the refrigerant inlet and the refrigerant outlet of the expansion valve, the refrigerant is placed along the circumferential bulging portion. And a fastening means for bringing the plate-shaped joint member into pressure contact with the refrigerant outlet and inlet forming surfaces of the expansion valve via an elastic seal member, and each of the refrigerant inlet side and outlet side pipe joints. The evaporator is characterized in that the end sides are respectively swaged to the free ends of the refrigerant inlet and outlet pipes.