JPS6317576Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a brazing device that can automatically and accurately join aluminum brass pipes, particularly aluminum brass pipes used for high-pressure hydraulic piping, etc.

BACKGROUND OF THE INVENTION A flame-blown brazing method is widely used in current brazing work, in which a flame of acetylene gas, propane gas, or the like is blown onto the brazing part to heat it.

However, when implementing this brazing method, especially when joining aluminum brass pipes, special work knowledge and judgment based on extensive experience are required, as described below. Satisfactory work can only be done by skilled workers, but
On the other hand, it has become extremely difficult to obtain these skilled workers.

Matters to be observed when enforcing the Blow Flame Brazing Law include adjusting the flame and selecting the heating position of the flame, that is, adjusting the flame parts such as the white core and acetylene feather that make up the flame to the specified length. ,
It is necessary to apply a specific position inside the flame adjusted in this way to the brazing part and heat it. The heating procedure of the pipe is to move the specified position of the flame in a spiral along the outer surface of the pipe joint. Ability to judge heating temperature by color, that is, brazing temperature is approximately 700
The temperature is less than ~800 degrees, and the metal to be heated emits a dark cherry or cherry color, but it is difficult to distinguish the colors depending on the brightness of the work place. In addition to the ability to judge when brazing is complete, that is, the ability to judge when and how the solder is coming out due to capillary action, there is also a need for the ability to judge when the solder is coming out due to capillary action.In addition, in terms of the working environment, it is necessary to have the ability to judge when brazing is complete, that is, when the solder is coming out due to capillary action, and in other aspects of the work environment. Indoor temperature rises. In order to visually check the brazed parts, a space is required for the body to enter, or it is necessary to erect scaffolding. There are drawbacks such as the need for explosion-proof measures if there are flammable materials nearby, the work environment is poor, and it takes time to prepare for work.

As a measure to avoid the above-mentioned problems, there is an electrical resistance brazing method shown in FIGS. 1 and 2. In this method, the pipes a and a to be connected are inserted into a sleeve-shaped socket b, and a welding transformer (not shown) is used to energize the socket b via carbon electrodes c and c attached to the outside of the socket b. The solder is melted by the electrical resistance heat generated in the brazed part.

However, this method has the drawback that if the shape of the carbon electrodes c and c, especially the shape of the part where the carbon electrodes c and c come into contact with the tube a, is poor, sparks will generate craters in the current-carrying part, and this method cannot be applied. There was also the inconvenience that the pipe material was limited to extremely small diameter copper pipes (within an outer diameter of 15 mm).

The present invention was made to solve the above-mentioned drawbacks, and the welding material for welding the brazed parts is brought into contact with the electrically resistance-heated brazed parts, and the heat conduction from the brazed parts is utilized. Melts the contacting welding material,
This relates to a brazing device that is configured to cut off the heating power supply when a predetermined amount of welding material has melted. It has the advantage of being able to perform high-quality brazing and improving work efficiency.

Hereinafter, embodiments of the present invention will be described based on the drawings. Figures 3 to 7 show the first embodiment of the present invention. In the figures, numerals 1 and 1 are aluminum brass pipes (hereinafter referred to as pipes), 2 is a pipe connection socket, and 3 is a welding socket. Transformer, 4, 4 is electrode holder 5
carbon electrodes are brought into contact with both sides of the socket 2 using 7
and 8 to the welding transformer 3 and the DC power source 9, respectively.

The sensor 6 is connected to a silver solder rod 1 as shown in FIG.
0, a holder 11 that holds the silver solder rod 10, a clip 13 that supports the holder 11 on the tube 1 via an angle-adjustable joint 12, etc. It is attached to the pipe 1 using a clip 13 so as to abut the gap, that is, the raised portion 15 during brazing at an appropriate angle. Further, the silver soldering rod 10 includes a spring 16 provided in the holder 11, a groove k, and a silver soldering rod 1.
A predetermined stroke e (for example,
10 mm) in the direction of the tip of the silver solder rod 10 (arrow f).

The operation of the sensor 6 will be described later, but when the brazing part reaches a predetermined brazing temperature, the tip 14 of the silver soldering rod 10 melts, and when melted, it is pushed out in sequence by the force of the spring 16 (as indicated by the arrow f). ), when the predetermined stroke e is melted, the tip portion 14
Since it is separated from the raised portion 15, it has the role of electrically detecting that point and cutting off the carbon electrodes 4, 4.

The power supply circuit for the sensor 6 is shown in FIG. 4, and the cutoff circuit 38 for the carbon electrodes 4, 4 is shown in FIG. In the figure,
9 is a DC power supply with a voltage of 3V, 18 and 19 are relays, 20 and 21 are a contacts of relays 18 and 19,
22 is a starting push button, 23 is a timer, 24 is a b contact of the timer 23, and the operation time limit of the timer 23 is 0 to 6 minutes. Note that it is convenient to handle and move the device if each of the above-mentioned circuits is incorporated together inside the welding transformer 3.

The carbon electrodes 4, 4 are connected to the fulcrum 2 as shown in FIG.
The shape of the part that is attached to one end of the two levers 26, 26 that intersect with each other via the lever 5 and that comes into contact with the socket 2 is a deep one that extends in the longitudinal direction of the socket 2 (arrow g) as shown in FIG. It has an arc-shaped recess 27 with a diameter of about 2 to 3 mm, and when this recess 27 is pressed against the outside of the socket 2 and energized, the socket 2
No craters occur. In addition, 2 in the figure
8 indicates a spring, and h indicates the depth of the recess 27.

Next, the handling procedure and operation of this device will be explained. When performing brazing work, use sandpaper to remove and clean oxides on the metal surface of the joint. Apply flux to the inside of the socket 2 and the socket insertion portions of the tubes 1 and 1. Insert tubes 1, 1 fully into socket 2. Carbon electrodes 4, 4
is attached to the outside of the socket 2 using the holder 5. With the silver solder rod 10 of the sensor 6 retracted to the maximum, the tip 14 is set in the silver solder embossed portion 15. Set the operating time limit of the timer 23. The activation time limit is set to 6 minutes for the first brazing, and from the second onwards, the actual brazing time for the first time plus 30 seconds, i.e., for example, 2 minutes and 30 seconds after energization. If the power to the carbon electrodes 4, 4 is cut off, the time is set to 3 minutes.

Since the preparation for brazing is completed in the above manner, the push button 22 is now pressed to start energization. When the brazed part is heated by electrical resistance heat to around 500 degrees Celsius, the flux begins to melt. Brazed part is approx.
When the temperature is raised to 650 degrees Celsius, the wax starts to melt and comes out into the gap between the tube 1 and the socket 2, that is, into the raised portion 15 due to capillary action. At this point, the tip 14 of the sensor silver solder rod 10 also begins to melt. On the other hand, since the silver soldering rod 10 is pressed against the raised part 15 by the spring 16, the melted silver rod 10 is successively pushed out and brazing progresses during this period, and the amount of melted metal corresponds to the melting time required for brazing. , i.e. 1
When the silver solder of stroke e melts, the tip 14
is separated from the raised portion 15, and the relay 18 provided in the DC power supply circuit is demagnetized.

Next, the relay 19 of the cutoff circuit is demagnetized, the a contact 21 of the relay 19 is opened, the primary circuit of the welding transformer 3 becomes voltageless, and the brazing is completed.
If the sensor 6 does not operate for some reason, the timer 23 operates and the b contact 2
4, the relay 19 is demagnetized, the primary circuit of the welding transformer 3 is opened, and brazing is completed.

To restart the brazing work, set the silver solder rod tip 14 of the sensor 6 on the raised part 15 again, press the reset button (not shown) provided in the DC power supply circuit, and excite the relays 18 and 19. Then press the push button 22 to perform brazing.

As described above, since the moment when the silver soldering rod is separated is detected and the power source for melting and heating the brazing portion is cut off, brazing can be performed automatically. In addition, since the socket contact portions of the carbon electrodes 4, 4 are formed in an appropriate shape, there is no risk of creating a crater due to sparks in the heated portion.

A second embodiment of the present invention is shown in FIGS. 8 and 9. This example is equipped with a multiple holder 29 that simultaneously presses a large number of carbon electrodes 4, 4 against aluminum brass tubes 1 arranged in parallel, and automatically brazes multiple locations at once. can be completed. In this case, the sensor 6 is installed at each brazed part, and each sensor 6 is installed at each brazed part.
The power to the welding transformer 3 is sequentially cut off in response to signals from the welding transformer 3.

The multiple holder 29 has two supports 30,
30 and opposing surfaces 31 of the supports 30, 30,
A holder 34 having a convex portion 33 that fits into the dovetail groove 32 provided in the dovetail groove 31 so as to be movable in the parallel direction (arrow i) of the tube 1, and a spring 35 and a ball 36 that press each holder 34 to the outside of the socket 2. A cable 37 is attached to each carbon electrode 4 to connect the carbon electrode 4 to a DC power source 9. Therefore, by using this brazing device, a large number of pipes 1 can be efficiently brazed in a very short time.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

Since the brazing device of the present invention has the above-described configuration, it exhibits the following excellent effects.

(i) Since electrical resistance brazing is used, all the problems associated with conventional blow-flame brazing operations can be eliminated. That is, it is possible to uniformly heat the gas burner at a predetermined brazing temperature without relying on skilled technicians who are required to properly handle the gas burner. This allows you to work safely, freeing you from harsh working conditions such as working under high temperatures during the summer or working in narrow spaces. It helps save labor by omitting troublesome preparation work such as taking explosion-proof measures and erecting scaffolding.

(ii) A brazing completion detection sensor is installed to automatically complete brazing when the brazing part reaches a predetermined temperature and a predetermined amount of welding material has melted, allowing high-quality brazing to be performed. .

(iii) By forming the shape of the portion where the carbon electrode contacts the tube into a predetermined shape, it is possible to prevent the generation of craters due to sparks when electricity is applied.

By using a multiple holder, a large number of pipes can be brazed at once, and in conjunction with the results described in the previous item (i), work efficiency can be greatly improved.

[Brief explanation of the drawing]

Figures 1 and 2 show the shape of a carbon electrode in a conventional resistance brazing method, with Figure 1 being a side view, Figure 2 being a view taken from the - direction in Figure 1;
3 to 7 show the first embodiment of the present invention, and FIG. 3 is a side view of the brazing completion detection sensor;
Figure 4 is a wiring diagram of the DC power supply circuit, Figure 5 is a wiring diagram of the power cutoff circuit, Figure 6 is a side view of the electrode holder, Figure 7 is an enlarged perspective view of the electrode shown in Figure 6, and Figure 8. 9 shows a second embodiment of the present invention, FIG. 8 is an external view of the multiple holder, and FIG. 9 is a view taken from the - direction in FIG. 8. In the figure, 4 is a carbon electrode, 6 is a brazing completion detection sensor, 10 is a silver solder rod, 11 is a holder, 15 is an embossed portion, and 38 is a cutoff circuit.

Claims (1)

[Scope of utility model registration request] A brazing device that applies current through electrodes to heat and weld a brazing portion by electric resistance heat, comprising: a brazing completion detection sensor that supports a welding material for welding in contact with the brazing portion and such that the contacted welding material moves away from the brazing portion after a predetermined amount of melting; and an electric circuit that detects the point in time when the welding material moves away and cuts off the power supply for heating the brazing portion.