KR101890279B1 - A thermal resistance complex connection method for copper aluminum pipe - Google Patents

Abstract

The present invention relates to a copper-aluminum-pipe thermal resistance hybrid connection method, in which, in order to solve problems such as high welding brittleness between conventional copper pipe aluminum pipes, easy generation of cracks and pores, and low cooling efficiency, A copper pipe having a rotary swaging necked end head is attached to the aluminum pipe and the aluminum pipe under the action of the impact rod, and an electrode holder composed of a lower electrode, a clamp is installed in the working cavity of the upper electrode and the lower electrode, A cooling gas injection device is installed in a working cavity portion, a cooling water pipe is installed in the upper electrode and the lower electrode and in the working cavity, and the connection process is performed by setting parameters, pre-installing a copper pipe aluminum pipe, Heat Resistance Operation and Impact Bar Hot Forging Complex Step . The impact rod is freely centered during the process and the copper aluminum matching area is tightly integrated and fused, accelerating the work cycle and making the work process smooth.

Description

TECHNICAL FIELD [0001] The present invention relates to a copper-aluminum pipe heat resistance composite connection method,

FIELD OF THE INVENTION The present invention relates to the field of copper aluminum welding, and more particularly to copper aluminum pipe heat resistance composite connection methods.

Copper aluminum welding refers to an integral connection of copper-based materials and aluminum-based materials through a welding process. Because copper and aluminum are metals that are easily oxidized, welding of copper and aluminum has been internationally regarded as a barrier to welding. Conventionally, copper and aluminum are usually welded using a tin plating and melting method. This method has a poor molding quality and a limited strength. Since tin has a low melting point and can not be welded in a high temperature working environment, the process described above is suitable for use in small workpieces under low temperature conditions. Copper aluminum welding using welding methods, such as welding, friction welding, cold welding, explosion welding, electron beam welding, ultrasonic welding, etc., has a large brittleness of the connecting head, which easily causes cracks and pores and can prevent cracks in the welded workpiece none. In addition, after cracks occur, conductor short circuits and pipeline leaks may occur and the effects required in actual production can not be achieved. In general, copper and aluminum are welded together using flame soldering, in-furnace soldering, high frequency soldering or the like, and solder is used as an intermediate medium to weld copper and aluminum through a brazing process. For example, copper aluminum explosive composite power T-type copper aluminum bimetal binding clip and explosion welding method designed by patent CN101707295B include two opposing binding clip main bodies. And the binding clip main body substrate is made of aluminum, and one layer of copper is explosively welded at one end of the substrate surface. On the main body surface of the binding clip, opposing arcuate grooves arranged in T type for causing a pressing wire action There are male thread holes on both sides of the arched groove, and the main body of the two binding clips conducts the crimp connection through the male thread. Such a method is suitable only for a power copper aluminum connection T type binding structure and is not suitable for connection between copper aluminum pipe bodies. In another example, Patent No. CN105364293A relates to a copper aluminum welding process in which a cleanly stacked plate material and a clean foil material of the plate to be welded are matched, a foil material is placed thereon, And then the welded joint is formed by extruding the pits on the welded portion through the pressure head moving along the basic method so that the electrical resistance of the connection between the foil material and the plate material is not higher than the electrical resistance of the welded wire under the same conditions. This method can not be used for the pipe-pipe connection process as well.

It is an object of the present invention to provide a copper-aluminum-pipe heat resistance composite connection method, which can solve the problems such as high welding brittleness of conventional copper pipe aluminum pipes, easy generation of cracks and pores, low efficiency of cooling method, .

In the present invention, the following technical solutions have been adopted to solve the above technical problems.

The present invention relates to a copper-aluminum-pipe heat resistance hybrid connection method, which comprises an electrode holder composed of an upper electrode and a lower electrode, a clamp is installed in a working cavity of the upper electrode and the lower electrode, and a rotary swaging ) A copper pipe having a necked end head is connected to an aluminum pipe under the action of an impact rod, a cooling gas injection device is installed in a working cavity portion, a cooling water pipe is installed in the upper electrode and the lower electrode, The connection process includes parameter setting, copper pipe aluminum pipe pre-installation, clamp position fix, thermal resistance operation and shock bar hot forging combined steps. Thermal resistance is a function of the heat transfer function of a kind of object, and it is a heat transfer function suitable for characterizing homogeneous materials. The smaller the thermal resistance, the higher the thermal conductivity. Copper and aluminum have relatively low thermal resistance values, and this technology implements thermal resistance fusion using both material properties. Through this process, a copper-aluminum-pipe composite fusion connecting connector of 3 mm or more can be obtained, and the aluminum pipe material may be pure aluminum or aluminum alloy. By using the circulating water cooling system and the gas cooling system of this device, cooling of the work area is performed, so that the work interruption time is greatly reduced and semi-automatic or fully automatic operation is made possible for each propelling mechanism.

Preferably, the parameter setting is a copper pipe and an aluminum pipe standard, and a corresponding parameter of the preliminary pressure time, the preliminary heating current, and the preliminary heating time is inputted to the heat resistance controller, and the clamp pressure and the pushing pressure of the impact rod .

Preferably, the cooling water pipe belongs to a cooling water system, and the cooling water system is a circulation cooling system. It implements the purpose of a cooling electrode through a low-cost zero-emission scheme.

Preferably, the copper pipe end is provided with a rotary swaging necking in advance, the copper pipe rotary swaging necking end head is inserted into the aluminum pipe at the time of pre-installation of the copper pipe aluminum pipe, and at the same time, The impact rod is inserted and the position is fixed in the position restricting groove provided in the clamp. Conical monofilaments obtained by rotary forging processes on relatively elongate thin-walled copper pipes are rotary sectioning, which has a uniform wall thickness and a relatively good concentricity. The impact rod extends along the copper pipe center hole and advances the impact position fixation and extrusion adhesive connection.

Preferably, the front end clamp of the copper pipe is moved in the power unit within the preheating time during the operation of the thermal resistor, so that the copper pipe is inserted into the aluminum pipe portion and brought into intimate contact with the inner wall of the aluminum pipe. According to the principle of electric resistance welding, the preheating time is a process, the aluminum pipe clamp and the electrode fixation do not move, and the power unit moves the clamp and the electrode of the copper pipe so that the copper pipe enters the aluminum pipe end I make it. However, since the electrical resistance is a process of uniform heating, the pressure of the power plant is not sufficient to push all of the copper pipe rotary swaging neck portions into the aluminum pipe, thereby relatively controlling the connection operation relatively.

Preferably, the impact rod hot forging composite is a thermal resistance time end point, the impact rod rapidly advances, and the impact rod head portion advances a hot forging composite impact on the heat resistance connection portion, Pushing the copper pipe rotary swaging necking head completely into the aluminum pipe. Since the impact rod can be simultaneously removed with the weld residue in the copper pipe, the internal diameter of the copper aluminum connection portion can be assured.

Preferably, spherical nodes are arranged on the end of the impact rod, the spherical nodes having a plurality of smallest to smallest node diameters, and a maximum gap between the spherical node diameter and the copper pipe pore size is matched. Impact rod is made of stainless steel or high abrasion resistant alloy steel material. Impact rod head is processed with sagging spherical sphere and progressive expansion of the copper aluminum sphere inner diameter during impact results in material failure when the copper pipe conical rotary swaying end head is in intimate contact with the aluminum pipe inner wall completely , And the number of specific nodes may be more than one.

Preferably, the tail end of the impact rod is connected and fixed to the power drive by a movable sleeve, and the impact rod has a free motion width within an acute angle along the copper pipe centerline. Automatic center fixation is possible when working the impact bar.

Preferably, the cooling gas injection device includes a nozzle, and a cooling gas used after the connected workpiece moves moves cooling the blowing head to the impact rod head and the electrode clamp portion, and the cooling gas is compressed air Or nitrogen gas. The electrode clamp, and the impact bar head can be reduced and the work cycle can be accelerated.

Advantageous effects of the present invention are as follows. In other words, this device and connection method can obtain a copper-aluminum composite fusion connector of 3mm or more, and it is possible to prevent the occurrence of pores in cracks and weld cracks by allowing centralization and step-wise expansion molding free of impact bars during the work process, The parts are tightly integrated and fused together to accelerate the work cycle and smooth the work process by using the double cooling system of the circulating water cooling system and the gas cooling system.

1 is a structural view of a main operation section of the present invention;
2 is a structural view of the cooling water pipe operating structure of the present invention; And
3 is a structural view of the impact rod of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the drawings.

This embodiment relates to a copper aluminum pipe heat resistance composite connection method. 1, the basic facility includes an electrode holder composed of an upper electrode 1 and a lower electrode 2, and a clamp 4 (see FIG. 1) is provided in the working cavity of the upper electrode 1 and the lower electrode 2, And a shock bar 8 made of an alloy steel having high wear resistance so as to match the inner diameter of the copper pipe 5 with the welding end of the copper pipe 5 in advance by a conical rotary swaging necking stage head, And the copper pipe 5 and the aluminum pipe 6 are fixed to respective clamps 4 and connected to the corresponding electrodes, the clamp 4 is made of a red copper material, A cooling gas injection device 3 including nozzles is provided in the cavity (in the working cavity), and a cooling water pipe is installed in both the upper electrode 1 and the lower electrode 2 and the clamp 4 in the working cavity. 2, in the cooling water pipe operating structure, the water connector 7 includes one inlet interface 71 and one outlet interface 72, and the upper electrode 1 and the lower electrode 2 ), The cooling water pipe is returned to the left lower electrode-the upper left electrode-the upper right electrode-the lower right electrode, and finally to the outdoor cooling reservoir from the lower right electrode.

As shown in FIG. 3, a spherical joint 81 is provided at the end of the impact rod 8, the spherical joints 81 being arranged from the smallest to the largest three joints. The spherical joint 81 is located between the maximum spherical joint diameter and the And the tail end of the impact rod 8 fixes its position to the pneumatic cylinder power driver by means of a movable sleeve and the impact rod 8 is moved in one 10 ° cone acute angle along the center line of the copper pipe 5 That is, the center line of the copper pipe 5 is centered and has a degree of freedom of 10 [deg.] Acute along one circumference of the copper pipe 5. [

The motive power of the power device, the power propulsion device and the power driver in the present invention all come from pneumatic cylinders. Specific work processes include parameter setting - water cooling operation - copper pipe aluminum pipe preliminary installation - clamping position fixing - thermal resistance operation - impact rod hot forging compound - impact rod reset - clamp release - workpiece movement - gas cooling.

1. Parameter setting: According to the specification of copper pipe (5) and aluminum pipe (6), the corresponding parameter of preliminary pressure time, preheating current and preheating time is input to thermal resistance controller, clamp (4) Impact rod (8) Adjust thrust pressure. Table 1 and Table 2 show each parameter numerical table under two output conditions.

2. Water Cooling Operation: The cooling water pipe belongs to the cooling water system. The cooling water system is circulation cooling type. The cooling water circulates in the electrode holder and circulates heat with the outdoor cooling reservoir to achieve electrode cooling purpose. .

3. Copper pipe aluminum pipe installation: Copper pipe (5) The rotary forging necking end is inserted into the aluminum pipe (6), and at the same time the other end of the copper pipe (5) is inserted into the impact rod (8) The end of the aluminum pipe 6 is aligned with the end face of the electrode holder so as to be flat and aligned.

4. Clamp position fixing: The electrode clamp (4) tightly fits the welding workpiece through the pneumatic cylinder.

5. Thermal Resistance Operation: Based on the principle of electrical resistance welding, the power propulsion cylinder moves the electrode clamp of the copper pipe 5 in the direction of the aluminum pipe 6 within the preheating time, and the rotary forging of the copper pipe 5 Is inserted into the hole in the aluminum pipe (6) so as to be in intimate contact with the inner wall of the aluminum pipe (6).

6. Impact rod hot forging composite: After waiting for the thermal resistance time, the impact rod (8) rapidly advances under the action of the impact pneumatic cylinder pressure, and the impact rod (8) head moves hot forged composite impact And moving the pneumatic cylinder so that all of the copper forging (5) rotary forging neck portion is pushed into the aluminum pipe (6), thereby realizing a close hot-melt hybrid connection of the copper pipe (5) At the same time, the impact rod (8) also removes welded debris inside the tube, ensuring the internal pore diameter of the copper aluminum connection.

7. Reset the Impact Bar: The Impact Bar (8) resets to the state waiting for the impact to proceed and prepares for the next task.

8. Release the clamp: reset the pneumatic cylinder and the electrode clamp (4) relaxes the workpiece.

9. Move the workpiece

10. Gas Cooling: The cooling gas injector 3 controlled by the solenoid valve after the movement of the workpiece advances blow cooling to the head portion of the impact rod 8 and the electrode clamp 4, and the cooling gas is nitrogen gas to be.

The above embodiments are for illustrating the present invention and are not intended to limit the present invention. The structures, methods and the like after simple modification or substitution of the present invention belong to the scope of protection of the present invention.

1: upper electrode 2: lower electrode
3: Cooling gas injector 4: Clamp
5: Steel pipe 6: Aluminum pipe
7: Water connector 71: Receiving interface
72: Outgoing interface 8: Impact bar

Claims (9)

A copper aluminum pipe heat resistance composite connection method,
(4) is provided in the working cavity of the upper electrode and the lower electrode, and is provided with a rotary swaging necking stage head The copper pipe 5 is connected to the aluminum pipe 6 under the action of the impact rod 8 and the cooling gas injector 3 is installed in the working cavity portion and the upper electrode and the lower electrode, A cooling water pipe is installed, and the connection process includes a parameter setting, a copper pipe aluminum pipe pre-installation, a clamp position fixing, a thermal resistance operation and a shock bar hot forging composite step,
A plurality of spherical knurls 81 are arranged at the ends of the impact rod 8 so that the largest spherical joints 81 are arranged in a larger diameter and the largest spherical joints are matched with the largest gap between the bore diameters of the copper pipes 5 Characterized by copper aluminum pipe heat resistance composite connection method. The method according to claim 1,
The parameter setting is a standard of the copper pipe (5) and the aluminum pipe (6), and a corresponding parameter of the preliminary pressure time, the preliminary heating current and the preliminary heating time is inputted to the heat resistance controller, Characterized in that the propulsion pressure of the rod (8) is controlled. 3. The method according to claim 1 or 2,
Wherein the cooling water pipe belongs to a cooling water system, and the cooling water system is a circulation cooling system. The method according to claim 1,
A rotary swaging necking is installed in advance at the end of the copper pipe 5 and the copper pipe rotary swaging necking end head is inserted into the aluminum pipe 6 at the time of preinstallation of the copper pipe aluminum pipe, Wherein a shock bar (8) is inserted at one end and the position is fixed in a position limiting groove provided in the clamp (4). The method of claim 1, 2, or 4,
The front end clamp of the copper pipe 5 is moved in the power unit within the preliminary heating time during the operation of the thermal resistance so that the copper pipe is inserted into the aluminum pipe 6 and brought into intimate contact with the inner wall of the aluminum pipe. Copper aluminum pipe heat resistance composite connection method. The method of claim 1, 2, or 4,
The impact rod (8) hot forging composite is a heat resistance time end point, the impact rod rapidly advances, and the impact rod head part advances a hot forging composite impact on a heat resistance connection part, Wherein the copper pipe (5) rotary swaging necking head is pushed into the inside of the aluminum pipe (6) by pushing forward. delete The method according to claim 1,
Characterized in that the tail end of the impact rod (8) is connected and fixed to the power drive by a movable sleeve, the impact rod having a free motion width within an acute angle along the center line of the copper pipe (5) Resistance composite connection method. 9. The method according to any one of claims 1 to 7,
The cooling gas injector 3 includes a nozzle, and the cooling gas used after the connected workpiece moves advances the blowing cooling to the head portion of the impact rod 8 and the electrode clamp 4, Wherein the cooling gas is compressed air or nitrogen gas.

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