JP3513776B2 - Brazing method of metal tube and bracket - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for brazing a metal tube and a bracket. In particular, the present invention is suitable for fixing a bracket to a fuel pipe unit having a medium-thin pipe with an outer diameter of 6 to 10 mm. 2. Description of the Related Art A conventional metal pipe such as a steel pipe and a bracket (usually the same kind of metal as the metal pipe) have been brazed as follows (see FIG. 1). The metal tube 12 is brought into contact with the tube holding portion 16 of the bracket 14, and is temporarily fixed by TIG welding (inert gas arc welding) or projection welding (lap resistance welding). [0004] A rod-shaped brazing material 18 is placed at a portion where the metal tube 12 and the bracket 14 are to be brazed, and thereafter,
The bracket temporarily fixed body is carried into a heating furnace and brazed. In the example shown in FIG.
2a is a mounting bolt hole. However, in the case of the above-mentioned brazing method, there are the following problems, and the number of brazing steps is increased as a whole. [0007] The time and effort for welding that requires a technique for temporarily fixing the metal pipe to the bracket, and a special welding device are required, and a large current flows through the metal pipe when performing the above-described TIG welding or projection welding. Therefore, the metal tube is easily damaged, and a leak test after manufacturing the metal tube / bracket unit is required. When the metal tube / bracket temporarily fixed body is carried into the heating furnace, the rod-shaped brazing material may fall. The loading posture to the heating furnace is also limited, and after the loading, the brazing material must be aligned using a jig or the like. [0009] It takes extra time to set (place) the bar-shaped brazing material at the portion where the metal tube and the bracket are to be brazed. [0010] If a paste is used as the brazing material, the above-mentioned problems can be solved, but the dispersion of the coating amount is large, and it is difficult to obtain a stable brazing strength between the metal pipe and the bracket. , Undesirable, and, again,
Extra work is required to apply the paste brazing material to the portion where the metal tube and the bracket are to be brazed. In view of the above, according to the present invention, when brazing a metal pipe and a bracket, the metal pipe / bracket temporary fixing body can be prepared without welding, and the metal pipe / bracket temporary fixing body can be prepared. In order to provide a brazing method capable of greatly reducing the number of brazing steps as a whole, there is no risk that the bar-shaped brazing material will fall when it is carried into the heating furnace, and the labor for setting the bar-shaped brazing material is almost unnecessary. Aim. A method for brazing a metal tube and a bracket according to the present invention solves the above-mentioned problems by the following constitution. [0013] The bracket is temporarily fixed to the metal tube via the groove-shaped tube holding portion, and a rod-shaped brazing material is placed at a portion where the metal tube and the bracket are to be brazed.
When the bracket temporarily fixed body is carried into a heating furnace and brazed, a brazing material holding hole is formed in the bracket during press working of the bracket, and a bar-shaped brazing material is pressed into the brazing material holding hole and held. Furthermore, the metal tube is temporarily fixed by a spring elastic clamp so that the metal tube cannot be rotated and slidably moved by the tube holding portion. The method of the present invention will be described below with reference to FIGS. The same parts as those described above are denoted by the same reference numerals, and all or part of the description thereof will be omitted. (1) The bracket blank and the metal tube after cutting are pressed so that the metal tube 12 can be spring-elastically clamped by the tube holding portion 16 so that it cannot be rotated and slidably moved. The metal tube 12 and the bracket 14 are prepared as shown in FIG. That is, the groove-shaped tube holding portion 1 of the bracket 14
6 are formed in a square groove shape (FIG. 4) or a U-shaped groove shape (FIG. 5) in which the facing surfaces are parallel to each other. Twelve clamp portions 13 are cut in both opposite surfaces or one opposite surface to have a pipe shape having a square cross section (FIG. 4) or an oval pipe shape (FIG. 5). At this time, the clamp portion 1 with the groove width b of the tube holding portion 16
3 is usually -0.1 to -1.0.
mm (preferably -0.2 to -0.5 mm). It is desirable that the opening end 16a of the tube holding portion 16 be tapered to open from the viewpoint of workability of clamping the metal tube 12 of the tube holding portion 16. (2) At the time of this press working, the bracket 14
A brazing material holding hole 19 is formed at an arbitrary position of the tube holding portion 16 and a bar-shaped brazing material 18 is pressed into the brazing material holding hole 19 (see FIGS. 4 and 5). Here, the interference between the brazing material holding hole 19 and the bar-shaped brazing material 6 is usually -0.1 to -0.5 mm.
(Preferably -0.2 to -0.4 mm). Also,
The length of the brazing material is a length corresponding to the brazing area. Although one brazing material holding hole 19 is formed at the bottom of the groove of the tube holding part 16 in the illustrated example, a plurality of brazing material holding holes 19 may be formed, or a combination thereof may be formed on one side wall or both side walls of the groove. May be. When the metal pipe and the bracket are made of steel, copper brazing, nickel brazing or the like is used. In the illustrated example, the bar-shaped brazing material 18 may be in the form of a rivet as shown in FIG. 4 or may be in the shape of a straight bar as shown in FIG. The press-fitting of the bar-shaped brazing material 18 is performed, for example, by
After the brazing holes 18 are formed, the brazing material is pressed into the brazing material holding holes 18 by hand or the like before the bracket bending process, or the brazing material is cut into the first part feeder and the bar-shaped brazing material. The second part feeder is automatically press-fitted (not particularly shown) around the turntable. (2) Next, the rod-shaped brazing material 1 is inserted into the brazing hole 19.
With the tube 8 held, the metal tube 12 is spring-elastically clamped to the tube holding unit 16 by the tube holding unit 16 of the bracket 14. This clamping work is performed by hand or by using a press-fitting jig. At this time, at least the clamp portion 13 of the metal tube 12 has a parallel surface with both sides or one side cut out, and locking step portions 13a, 13b on both sides of the clamp portion.
Is formed, the tube holding portion 16 cannot rotate and cannot slide with respect to the metal tube 12. At this time, the brazing filler metal 18 is
There is no danger of falling because it is press-fitted. (3) The metal tube / bracket temporary fixing body 20 thus prepared is continuously carried into a heating furnace by a mesh belt and brazed. The brazing condition is, for example, 1120 ° C. × 3 min for copper brazing. At this time, the brazing material 18 is
There is no danger of falling because it is press-fitted. The brazing material 18 in the holding hole 19 also melts and contributes to brazing. According to the method for brazing a metal tube and a bracket according to the present invention, the number of steps for brazing can be greatly reduced as a whole due to the following reasons. Instead of performing the temporary fixing by TIG welding or the like, the metal pipe can be fixed with a pipe holding part by a spring elastic clamp so that the metal pipe cannot be rotated and cannot be slid, so that a special device is not required and one-touch operation can be performed. it can. Therefore, unlike the related art, welding man-hours and special welding equipment that require technology are not required, and a leak test after manufacturing the metal pipe / bracket unit is not required. In order to press the brazing material into the brazing material holding hole,
The setting position of the brazing material is stable, there is no risk of sagging, and there is no risk of poor brazing. For the same reason as described above, there is no possibility that the bar-shaped brazing material will fall when it is carried into the heating furnace. For this reason,
The loading posture of the heating furnace is not limited, and there is no need to align the brazing material using a jig or the like after the loading. Since the formation of the brazing holes and the setting of the brazing material can be performed at appropriate times during the pressing process of the bracket, an extra man-hour for setting the brazing material is almost unnecessary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of a conventional method of brazing a metal tube and a bracket. FIG. 2 is a perspective view showing an example of a pressed metal tube used in the method of the present invention. FIG. 3 is a perspective view showing an example of a bracket after press working used in the method of the present invention. FIG. 4 is a cross-sectional view showing an example of a metal tube / bracket temporary fixing body in the method of the present invention. Cross-sectional view showing another example [Description of reference numerals] 12 Metal tube 13 Metal tube clamp portion 14 Bracket 16 Tube holding portion 18 Bar-shaped brazing material 19 Brazing material holding hole 20 Metal tube / bracket temporarily fixed body

Continuation of the front page (56) References JP-A-2-263592 (JP, A) JP-A 63-126694 (JP, U) JP-A 4-457 (JP, U) JP-B 63-23877 (JP) , B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 1/14 B23K 1/18 F16L 3/12

Claims (1)

(57) [Claims 1] A bracket is temporarily fixed to a metal pipe via a groove-shaped pipe holding portion, and a rod-shaped brazing material is put on a portion where the metal pipe and the bracket are to be brazed. Placing the metal tube / bracket temporarily fixed body into a heating furnace and brazing the metal tube / bracket. A brazing material holding hole is formed in the bracket during the press working step of the bracket, and the brazing material holding member is formed. The rod-shaped brazing material is pressed into and held in the hole, and the metal tube is held by the tube holding portion so as to be non-rotatable and non-slidably movable by spring elastic clamping, thereby performing the temporary fixing. To braze metal tube and bracket