JPS6347345Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement in a pipe joint that brazes a pipe and a connector through a tube sheet.

[Conventional technology]

As a conventional joint structure in which a pipe and a connector are brazed together through a tube sheet, the one shown in FIG. 1A and FIG. 1B, which is a vertical sectional view of the same, is known. This joint structure is mainly used for joints of corrugated fin type aluminum heat exchangers.

In FIGS. 1A and B, 1 is a tube (here, a multi-hole extruded flat tube is shown, but it may be a plurality of independent circular tubes), and 2 is a tube plate (with brazing material on one or both sides). brazed sheet),
2-1 is the brazing material, 2-2 is the core material, 3 is the connector,
4 is a threaded portion, 5 is an internal fluid passage (for refrigerant, etc.), 6 is a stepped portion provided in the connector 3 that supports the tube sheet 2, 7 is a fitting portion between the tube 1 and tube sheet 2, and 8 is a tube This is the fitting portion between the plate 2 and the connector 3.

To join this joint structure, first, the tube 1 is inserted into the fitting part 7 of the tube sheet 2, expanded, and the fitted assembly is press-fitted into the fitting part 8 of the connector 3, and the brazing material is heated in a brazing furnace. 2-1 is melted and solidified, and the tube 1, tube sheet 2, and connector 3 are joined by brazing.

[Problem that the invention attempts to solve]

However, this conventional joint structure has
There are drawbacks as shown below.

Now, assuming that the outer diameter of the tube plate 2 is dp and the inner diameter of the fitting portion 8 of the connector 3 is dc, there are drawbacks in the following cases.

(1) When dp<dc - Figure 2 A- In this case, the tube sheet 2 can be easily inserted into the fitting part 8 of the connector 3, but the fitting part 8 of the tube plate 2 and the connector 3 A gap 9 is created between the
When 0<G≦dc-dp, the fit between the tube plate 2 and the connector 3 becomes insufficient, and the two may come off during material handling or brazing, or the soldering may become defective. ,
This may cause refrigerant gas leakage. In addition, in order to obtain a good soldering condition, dc-dp is usually less than 0.5 mm.

(2) When dp≧dc - Fig. 2B - In this case, when △d = dp - dc < 0.1 mm, the connector 3 of the tube plate 2 is press-fitted into the fitting part 8 smoothly and sufficiently, making it easy to use during material handling. The tube sheet 2 and the connector 3 are not removed during brazing, and the brazing area is sufficient. However, in the region of the thickness l of the tube sheet 2, the peripheral end of the tube sheet 2 is compressed by the fitting portion 8, creating a region with no gap, and therefore the molten brazing filler metal is insufficiently penetrated. This results in joint strength being maintained by the fillet filler metal, which has the disadvantage of insufficient pressure resistance.

(3) When dp≫dc - Fig. 2 C - In this case, △d = dp - dc varies depending on the material and plate thickness, but it is 0.5 mm for Al material with a plate thickness of 2 to 3 mm.
As a result of the forcible press-fitting of the plate thickness 2 into the fitting part 8, the tube plate 2 is curved as shown in the figure, making it difficult to press-fit up to the step part 6, and making it difficult to press-fit the tube plate 2 into the fitting part 8. Since a gap 10 is formed between the two, there are drawbacks such as poor soldering, refrigerant leakage, and reduced pressure resistance.

As mentioned above, in the case of FIG. 2A, it is easy to insert the tube sheet 2 into the fitting part 8, but in the cases of FIGS. 2B and C, the fitting jig and process for press fitting are easy. It takes.

The present invention eliminates the above-mentioned drawbacks and provides a pipe joint with good workability and high reliability.

[Means for solving problems]

The present invention is a pipe joint in which a pipe and a connector are brazed to each other through a tube sheet made of a brazing sheet clad with brazing material on at least one side, so that the tube sheet inserted into the connector can be supported from behind. A soldering tube sheet made by inserting U-shaped insertion pins or insect pin-shaped insertion pins into at least two holes provided in each of the mutually facing parallel parts of the connector, and bending the tips of the pins that protrude from the outer surface of the connector. This relates to joints.

[Effect]

According to the present invention, since the U-shaped insertion pin or insect pin-shaped insertion pin supports the tube sheet inserted into the connector from behind, there is no need to press fit the tube sheet into the connector, and the tube sheet can be inserted into the connector. The outer diameter (dp) of the tube sheet should be smaller than or equal to the inner diameter (dc) of the connector to the extent that it can be easily inserted and that it will not come off during material handling or brazing or cause poor soldering. can.

〔Example〕

FIG. 3 is a diagram showing the appearance of a specific example of the present invention;
4A and 4B are views showing an example of the insertion pin according to the present invention, and FIG. 5 is a view showing the installation state of a hole for inserting the insertion pin (hereinafter referred to as an insertion hole).

In Figures 3 to 5, the same symbols as in Figures 1 to 2 are 1 to 5.
2 shows the same parts and the same functional parts, 11a is a U-shaped insertion pin, 11b is an insect pin-shaped insertion pin, 1
2 shows an insertion hole for an insertion pin.

For convenience of drilling, at least two pin insertion holes 12 are bored in each parallel surface of the connector (in this case, a hexagonal nut) 3, and the hole diameter is large enough to allow the insertion pins 11a and 11b to be easily inserted. Satoru. In addition, the distance m between the pin insertion holes 12 provided on the same plane should be larger than the short diameter h of the tube 1, and the distance k between the pin insertion holes 12 and the stepped portion 6 should be equal to or greater than the thickness of the tube plate 2. .

Also, the outer diameter dp of the tube plate 2 and the inner diameter dc of the connector 3
The relationship with is dp≦dc, and the difference △d=dc−dp≒
It is desirable to set it to 0-0.3mm. If △d is smaller than 0 (that is, dp > dc), the above-mentioned drawbacks of conventional methods (2) and (3), such as poor penetration of the molten brazing filler metal, bending due to press-fitting of the tube sheet into the connector, and brazing surroundings will occur. On the other hand, if Δd is larger than 0.3 mm, there is a risk of detachment or soldering defects, which are the drawbacks of the conventional method (1) mentioned above.

Next, the assembly procedure of the joint of the present invention will be explained. First, the tube 1 is inserted into the fitting portion 7 of the tube plate 2 (see FIG. 1B), and the expanded fitting is inserted into the stepped portion 6 of the connector 3.
Insert it until it touches the At this time, the direction of the tube 1 with respect to the pin insertion holes 12 is set in such a direction that the short diameter h of the tube 1 falls between the distance m between the pin insertion holes 12. Next, insert pin 11a or 11b (third
Insert a U-shaped insertion pin 11a (in the figure) into the pin insertion hole 12 so that the tube plate 2 is sandwiched between the stepped portion 6 and the insertion pin 11a or 11b,
Insertion pins 11a or 11b are inserted into pin insertion holes 12 provided on opposing surfaces of the connector 3, and the tips of the connectors 3 protruding outside are bent to prevent the insertion pins 11a or 11b from coming out. After that, put it in a heating furnace and fill it with brazing material 2-1.
[See Figure 1B] is melted, infiltrated, and solidified to complete the bonding.

FIG. 6 is a diagram showing another example of the joint of the present invention, in which a large number of small-diameter circular pipes 1a are used as the pipes 1.

[Effect of idea]

According to the joint of the present invention as explained above, the U-shaped insertion pin or the insect pin-type insertion pin supports the tube sheet from behind, and this back-up action prevents the tube sheet from being removed during material handling or brazing. will not fall off from the connector, and (ii) the outer diameter dp of the tube sheet and the inner diameter dc of the connector should be dp≦
dc, and if the difference △d is selected appropriately (that is, △d = dc - dp ≒ 0 to 0.3 mm), insertion is easy because there is no need to press fit the tube plate into the connector. Moreover, the brazing material completely penetrates into the gap between the tube sheet and the connector, and there is no refrigerant gas leakage or decrease in pressure resistance strength.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of a conventional joint structure.
is an external view, B is a vertical sectional view, FIGS. 2A to C are views for explaining the drawbacks of this conventional joint structure, and FIGS. 3 and 6 are external views showing an example of the joint structure of the present invention. 4 is a diagram showing the shape of the insertion pin according to the present invention, and FIG. 5 is a diagram showing the installation state of the insertion hole of the insertion pin according to the present invention. 1...Pipe, 2...Tube plate, 3...Connector, 4...
...Threaded part, 5... Internal fluid passage, 6... Step part,
7, 8... Fitting portion, 9, 10... Gap, 11a...
...U-shaped insertion pin, 11b...Insect pin-shaped insertion pin, 12...hole.

Claims (1)

[Scope of utility model registration request] In a pipe joint in which a pipe and a connector are brazed together through a tube plate made of a brazing sheet clad with a brazing material on at least one side, at least two holes are bored in each of the mutually facing parallel parts of the connector, and the connector A U-shaped insertion pin or an insect pin-shaped insertion pin is inserted into the opposed holes so as to support the tube plate inserted inside from the back, and the tip of the pin protruding from the outer surface of the connector is bent. tubesheet brazed joints.