Non-contact heating tin brazing method for metal structural part and coaxial cable
Technical Field
The invention relates to the technical field of processing, in particular to a welding process of key parts in the technical field of communication, and particularly relates to a non-contact heating tin brazing method for a metal structural part and a coaxial cable.
Background
The base station antenna is a key part covered by a mobile communication network, and the core part of the base station antenna is mostly formed by connecting a metal structural part (a radiation unit) and a coaxial cable in a tin soldering mode. In order to ensure good electrical connection conductivity and structural connection stability, strict requirements are placed on the consistency of tin amount of welding spots, the permeability of the welding spots and the mechanical strength, and therefore quantitative management and control of welding process parameters are an important premise for achieving product consistency.
As is well known, in the conventional soldering process, a soldering iron generates heat to make contact with a soldered point to conduct heat, and at the same time, the soldering iron assists in filling solder, which is a local heating soldering method. The welding mode of the metal structural part in the communication industry is basically the welding mode by adopting the electric soldering iron. Because the endothermic effect of metallic structure spare, can satisfy the welding demand in order to make its heating, need higher temperature transmission or long-time contact welding, just must choose powerful welding stage for use, because long-time high temperature, the soldering bit oxidation accelerates, life reduces by a wide margin, the solder joint has aggravated simultaneously and has been heated inhomogeneous unable assurance welding temperature's uniformity and cause welding quality reliability to descend, on the other hand, adopt the manual welding mode, can't guarantee the welding time and send the uniformity of tin volume, the quality uniformity is poor, the operation mode inefficiency.
The antenna component of the base station mostly belongs to a special-shaped structural part, and the irregularity of the antenna component causes the multidirectional welding of welding spots of different products, namely, a large number of multi-dimensional welding spots exist simultaneously, and the welding is carried out by adopting a manual soldering iron, so that repeated placement and positioning are needed, and the full-automatic welding is basically impossible.
The industry also has some new attempts, adopts three-dimensional manipulator to drive the flatiron promptly and carries out the fixed-position welding, can solve the solder joint of coplanar to a certain extent, has solved simultaneously and has sent the quantification management and control of tin and soldering time, nevertheless still can't solve the endothermic influence that brings of metal structure spare from the principle, the solder joint reliability problem of production.
Disclosure of Invention
The invention aims to provide a non-contact heating tin brazing method for a metal structural part and a coaxial cable, which improves the welding efficiency and ensures the welding quality.
In order to achieve the purpose, the invention provides the following technical scheme:
a metal structural member and coaxial cable non-contact heating tin brazing method comprises an integral heating welding device with a transmission system, a heating system and a cooling system which are sequentially arranged along the transmission direction of a workpiece, and the method comprises the following steps: presetting a workpiece on a transmission system and transmitting the workpiece to a heating system, wherein the workpiece comprises a preassembly structure of a metal structural member and a coaxial cable, a welding flux preset at a welding point between the metal structural member and the coaxial cable and a turnover clamp used for positioning the preassembly structure; carrying out non-contact thermal radiation heating on the workpiece to fully melt the solder at the welding point; and cooling the workpiece subjected to the heat welding so that the welding point is rapidly solidified.
Preferably, when a plurality of longitudinally distributed welding spots are arranged between the same coaxial cable and the metal structural member, the heating system is subjected to parameter setting, so that the heating temperature in the heating area is in differential distribution in the longitudinal direction of the metal structural member.
Specifically, the heating temperature is distributed in a 'low-high-low' mode in the longitudinal direction of the metal structural part.
Preferably, when a plurality of welding points distributed on different planes are arranged between the same coaxial cable and the metal structural member, the heating system is subjected to parameter setting, so that the temperatures of different positions in the horizontal direction of the heating area are distributed in a differentiated manner.
Preferably, when a plurality of welding points distributed on different planes are arranged between the same coaxial cable and the metal structural member, welding materials with different melting points are added at the welding points on different planes.
Preferably, the step of heating the workpiece by non-contact thermal radiation specifically comprises: carrying out non-contact thermal radiation heating on the first surface of the metal structural member on which the welding spots are distributed, so that the welding spots on the first surface are cooled after the welding spots are melted to complete welding of the welding spots on the first surface; performing secondary assembly on the workpiece welded on the first surface and adding solder on the second surface, and then performing non-contact heating on the surface of the metal structural member to complete welding of welding spots on the second surface of the metal structural member; when the second heating welding is carried out, the heating temperature of the second surface is controlled to be lower than that of the first surface, or the melting point of the solder at the welding point on the first surface is higher than that of the solder at the welding point on the second surface, so that the welding point on the first surface is prevented from being melted during the second heating welding.
Further, the method also comprises a pre-assembly process of the workpiece, and specifically comprises the following steps: preparing a metal structural part and pre-positioning the metal structural part on a turnover fixture; assembling the metal structural part and the coaxial cable at a certain gap, and pre-tightening the metal structural part and the coaxial cable; solder is preset at the welding point between the metal structural member and the coaxial cable.
Preferably, the metal structural part and the coaxial cable are pre-tightened through a tightening type connecting part, and the clearance between the metal structural part and the coaxial cable is less than 0.1 mm.
Preferably, the solder is added to the welding point between the metal structural member and the coaxial cable by a three-dimensional type automatic solder adding device.
Further, the method also comprises the following steps of: and taking down the welded finished product from the turnover fixture, and returning the welded finished product to the turnover fixture through the transmission system.
Compared with the prior art, the scheme of the invention has the following advantages:
1. in the tin soldering method, the procedures of fixing a soldering device, adding solder and heating and soldering are separated, and the subdivision and optimization of the procedures are realized, so that the automatic high integration is easier to realize, the soldering efficiency is improved by nearly 3 times compared with that of a manual soldering iron, and the yield is improved to 99.99%.
2. The welding temperature is differentially controlled at different longitudinal positions or different directions in the same horizontal direction, so that the welding temperature is suitable for welding of welding points with different melting points, and the welding temperature uniformity is high; meanwhile, the temperature is controlled by a program, so that the requirements of the characteristics of the tin solder are met, and the fluidity of the solder and the strength of the formed welding spot are ensured.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic view of one embodiment of a workpiece being heat welded in an integral heat welding apparatus of the present invention;
fig. 2 is a schematic view of another embodiment of the invention for heat welding workpieces in an integral heat welding apparatus.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.
The invention relates to a non-contact heating tin soldering method (hereinafter referred to as a tin soldering method) for a metal structural part and a coaxial cable, which mainly comprises four steps of presetting a workpiece (containing solder adding), heating the workpiece in a non-contact manner, cooling the workpiece and disassembling the workpiece.
The solder is added in the three-dimensional automatic solder adding equipment, so that the synchronous multi-point addition of the solder at the welding points needing to be welded can be realized, the solder has accurate quantification and the shape of the solder is changed to ensure the consistency of the flowing distance of the solder in the welding process.
Non-contact heating is gone on in whole heating welding set, this whole heating welding set has the transmission system who is used for transmitting the work piece and sets gradually heating system and cooling system along work piece transmission direction, and heating system is used for carrying out 360 degrees all-round thermal radiation to the work piece, make every position of product, the position all can the thermally equivalent, thereby make the solder on the solder joint fully absorb heat and melt, and then wet between the solder joint between metallic structure spare and coaxial cable, flow, then cool off and make the liquid solder of solder joint department solidify fast and form required solder joint.
The integral heating welding device adopts a heat radiation transfer mode to transfer heat, the heating element of the integral heating welding device comprises but is not limited to infrared heating, heating tube heating, laser heating and other heating modes, the heating direction is not limited to upper heating, lower heating or upper and lower heating, and the integral heating welding device can heat in multiple directions simultaneously.
Example one
And taking the metal structural part out of the turnover box, and pre-positioning and placing the product of the metal structural part body.
Assembling a gap between the coaxial cable and the metal structural member; after the assembly is ensured in place, the coaxial cable is fixed on the metal structural member by adopting a hooping type connecting piece. The pre-tightening of the hooping type connecting piece can ensure the effective and reliable fixity of a plurality of coaxial cables, so that the gap between the metal structural piece and the welding spot of the coaxial cable is smaller than 0.1mm, namely, the gap between the metal structural piece 2 and the welding spot 6 in figure 1 is ensured, and the consistency of the welding effect is ensured. The hooping type connecting piece has the high-temperature resistance, and can prevent the object from losing efficacy due to the effects of expansion with heat and contraction with cold; simultaneously, the hooping type connecting piece has the characteristic of quick taking and placing.
And (3) putting the metal structural part assembled with the coaxial cable into a three-dimensional automatic solder adding device for solder adding. The automatic solder adding equipment can complete synchronous multi-point adding of the solder at the welding point required to be welded, so that the adding of the solder has accurate quantification and consistent shape of the solder, and the consistency of the flowing distance of the soldering tin in the welding process is ensured.
And placing the pre-assembly structure consisting of the metal structural part and the coaxial cable, which finishes the automatic addition of the welding flux, into a turnover fixture with limiting and positioning functions, and limiting and positioning through the turnover fixture. The turnover fixture is high-temperature resistant, so that the fixing reliability and the placing flexibility of the metal structural part are guaranteed. And can realize the simultaneous spacing and positioning of a plurality of preassembly structures on one turnover fixture.
Thereby, the pre-assembly process of the workpiece is completed. Wherein, the work piece refers to the community that metallic structure spare, coaxial cable, solder and turnover anchor clamps constitute.
The workpiece is placed on a transmission system of the integral heating welding device 1, the transmission system transmits the workpiece to the heating system to heat the workpiece in a heat radiation mode, so that the welding flux is melted, flowed and diffused in a welding spot in a fully heat absorption mode, and the workpiece is transmitted to a cooling system after the heating welding is completed to cool the workpiece so that the liquid welding flux is rapidly solidified to form the required welding spot.
After the welding of the metal structural part and the coaxial cable is finished, the welded finished product is taken out of the turnover fixture and is returned to the turnover fixture through the transmission system, so that a complete small cycle of machining procedures is finished
The welding device is fixed, the welding flux is added, and the heating welding is carried out for multi-process separation, so that the fine division of labor is beneficial to realizing automatic and modular management of each process, the welding efficiency is improved, and the welding quality is ensured.
With continued reference to fig. 1, preferably, the same coaxial cable and the metal structural member have three welding points 4, 5, 6 in the longitudinal direction, and the three welding points are respectively distributed at three positions of "low-middle-high" of the metal structural member, where the welding point 4 is a small welding point and the welding point 5 is a large welding point. In order to ensure that the insulating medium of the coaxial cable is not melted, temperature differential control is carried out on the heating area in the longitudinal direction, which is embodied as low-high-low, namely the temperature of the welding point 5 is higher than the temperature of the welding point 4 and the welding point 6. The welding temperatures of the welding spots with different sizes at three levels of the three-dimensional metal structural member are differentiated through the layered arrangement of the temperatures.
Example two
Referring to fig. 2, the present embodiment is similar to the first embodiment, except that:
have a plurality of solder joints of distributing on different planes between same coaxial cable and metallic structure 2, heat in order to realize the solder joint on different planes to in the welding process of heating at the back, can not influence the solder joint that the previous time heating welding formed, in the welding process of heating of this embodiment, carry out parameter setting to heating system, make the temperature on the different positions of heating region horizontal direction be the differentiation and distribute.
Thus, the step of heating the workpiece by non-contact thermal radiation specifically comprises:
and carrying out non-contact thermal radiation heating on the first surface of the metal structural member on which the welding spots are distributed, so that the welding spots on the first surface are welded after the welding spots are melted and cooled.
And (3) performing secondary assembly on the workpiece welded on the first surface and adding solder on the second surface, and then performing secondary non-contact heating on the metal structural member to complete welding of welding points 3, 4, 5 and 6 on the second surface of the metal structural member 2.
During the second heating welding, the second surface of the metal structural member 2 is heated to a temperature higher than that of the first surface, so that the welding spots 7 and 8 formed on the first surface are prevented from being melted during the second heating welding.
Or, the solders with different melting points are added at the welding points on different planes, so that the melting point of the solders at the welding points 7 and 8 on the first surface is higher than that of the solders at the welding points 3, 4, 5 and 6 on the second surface, and the welding points 7 and 8 formed on the first surface are prevented from melting during secondary heating welding.
In order to adapt to the positioning of the metal structural part and the coaxial cable pre-assembly structure of the embodiment, a multi-surface type turnover fixture with a pre-pressing device is adopted in the embodiment, the turnover fixture can realize the simultaneous positioning of a plurality of products, and the relative position between every two metal structural parts is ensured, so that the relative position tolerance is less than +/-0.03 mm.
The foregoing is only a partial embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.