阅读说明：本技术 一种铅黄铜腔体炉中钎焊加工方法 (Brazing processing method for lead brass cavity in furnace ) 是由 田叶青 于 2021-08-31 设计创作，主要内容包括：一种铅黄铜腔体炉中钎焊加工方法,包括以下步骤：步骤S1：在凸台和壳体上加工出螺纹孔,采用定位销插设在螺纹孔中将所述凸台安装在所述壳体上,并在凸台与壳体之间设置焊片,得到待焊接组件；步骤S2：将焊接工装放置在炉膛中并随炉一起升温,待炉膛内温度上升至焊接温度时将步骤S1中待焊接组件放置在焊接工装上进行炉中钎焊；步骤S3：对进行炉中钎焊后的得到的工件进行焊后处理,焊后处理工序包括钎剂残留物及焊渣清理,以及喷砂。本发明采用定位销固定的方式代替传统工艺中钢丝捆扎固定方式,避免焊接过程中因钢丝膨胀变松而垮掉,导致组件定位不紧出现焊缝不连续、漏焊现象；避免了钢丝焊接过程中因碳化加重表面污染,减轻焊后清洗强度。(A brazing processing method in a lead brass cavity furnace comprises the following steps: step S1: processing threaded holes in the boss and the shell, installing the boss on the shell by inserting a positioning pin into the threaded holes, and arranging a soldering lug between the boss and the shell to obtain a component to be welded; step S2: placing the welding tool in a hearth, heating the welding tool along with the furnace, and placing the component to be welded in the step S1 on the welding tool for furnace brazing when the temperature in the hearth rises to the welding temperature; step S3: and (3) carrying out post-welding treatment on the workpiece obtained after furnace brazing, wherein the post-welding treatment process comprises the steps of cleaning brazing flux residues and welding slag and sand blasting. The invention adopts a positioning pin fixing mode to replace a steel wire bundling fixing mode in the traditional process, and avoids the phenomena of discontinuous welding seams and welding leakage caused by loose expansion of the steel wire in the welding process; avoids the surface pollution aggravated by carbonization in the steel wire welding process and lightens the cleaning strength after welding.)

1. A brazing processing method in a lead brass cavity furnace is characterized by comprising the following steps:

step S1: processing threaded holes (30) in the boss (20) and the shell (10), installing the boss (20) on the shell (10) by inserting positioning pins (40) in the threaded holes (30), and arranging soldering lugs (50) between the boss (20) and the shell (10) to obtain a component to be welded;

step S2: placing the welding tool (60) in the hearth (70) and raising the temperature along with the furnace, and placing the assembly to be welded in the step S1 on the welding tool (60) for furnace brazing when the temperature in the hearth (70) rises to the welding temperature;

step S3: and (3) carrying out post-welding treatment on the workpiece obtained after furnace brazing, wherein the post-welding treatment process comprises the steps of cleaning brazing flux residues and welding slag and sand blasting.

2. The brazing process in a lead brass chamber furnace as claimed in claim 1, wherein: the positioning pin (40) is made of a carbon arc gouging carbon rod.

3. The brazing process in a lead brass chamber furnace as claimed in claim 1, wherein: in step S2, before the assembly to be welded is placed in the furnace, the flux is modulated into a paste with acetone and applied to the weld.

4. The brazing process in a lead brass chamber furnace as claimed in claim 1, wherein: in step S1, the positioning pin (40) includes a threaded portion (401) and a compression head (402); when the boss (20) is installed on the shell (10), the thread part (401) is in threaded connection with the boss (20) and the threaded hole (30) in the shell (10), and the pressing head (402) presses the boss (20).

5. The brazing process in a lead brass chamber furnace as claimed in claim 4, wherein: the positioning pin (40) is formed by integrally turning the threaded part (401) and the pressing head (402).

6. The brazing process in a lead brass chamber furnace as claimed in claim 1, wherein: in step S3, the method for cleaning flux residues and welding slag includes: and (3) putting the workpiece obtained after the brazing in the furnace into 10% citric acid, boiling for 15-20 min, brushing brazing flux residues and welding slag on the surface of the workpiece by using a steel wire brush, and finally washing the surface of the workpiece and a welding seam by using flowing clear water.

7. The brazing process in a lead brass chamber furnace as claimed in claim 1, wherein: in the step S3, before the sand blasting, the workpiece is placed in an oven at 100 ℃ and kept warm for 1h to be dried.

8. The brazing process in a lead brass chamber furnace as claimed in claim 1, wherein: in step S1, the positioning pin (40) is stored in a drying cylinder, and if the positioning pin (40) is damp, the positioning pin is placed in an oven with the temperature of 100 ℃ for heat preservation for 1 hour and then used.

9. The brazing process in a lead brass chamber furnace as claimed in claim 1, wherein: in the step S2, the welding tool includes a backing plate (61), an arc-shaped groove (611) is provided on the backing plate (61), and the diameter of the arc-shaped groove (611) matches with the outer diameter of the housing (10).

10. The brazing process in a lead brass chamber furnace as claimed in claim 9, wherein: the welding tool further comprises a cushion block (62); the cushion block (62) is supported below the backing plate (61) so that the assembly to be welded is located at the central position of the hearth (70); the backing plate (61) and the cushion block (62) are both made of mullite materials.

Technical Field

The invention relates to the technical field of part processing of radio control instruments, in particular to a method for brazing a lead brass cavity in a furnace.

Background

The lead brass cavity (as shown in figure 1) is an important part of a radio controller of a certain type of product, and is connected with a cable assembly to form an electric signal transmission system. The lead brass cavity has high requirements on dimensional processing precision and surface quality, and is smooth and has good corrosion resistance.

The material of plumbous brass cavity is plumbous brass, and the structure includes the casing and welds the boss on the casing, is provided with the screw hole respectively on the boss and communicates to the inner chamber of casing in. The boss includes first boss and second boss, and is one in the quantity of first boss, and the quantity of second boss is two symmetries and sets up on the surface of casing.

When the boss of the lead brass cavity and the shell are brazed in a furnace, in the traditional process, the boss is fixed by binding the boss on the shell by using a steel wire (as shown in figure 2); when brazing in a furnace, the fixed assembly is placed in a welding furnace for brazing in the furnace, and argon is filled in the welding process; and (4) processing a threaded hole after welding.

The traditional process is adopted, the boss is fixed and positioned in a steel wire binding mode, and the thermal expansion of the steel wire is loosened due to the fact that the thermal expansion coefficient of the steel wire is different from that of lead brass of the assembly in the welding process, so that the boss is not tightly positioned, a welding seam is discontinuous, welding leakage occurs, and even welding is not performed, and therefore the one-time welding yield is low. In addition, the oxidation and carbonization phenomena of the steel wire in the welding process are serious, the surface of a part is blackened, the cleaning difficulty after welding is increased, the probability of unclean cleaning is increased, the cleaning difficulty of a silver plating process is increased, and the corrosion defect is easy to occur.

Disclosure of Invention

The invention mainly aims to provide a method for brazing lead brass in a cavity furnace, and aims to solve the technical problem.

In order to achieve the purpose, the invention provides a lead brass cavity furnace brazing processing method, which comprises the following steps:

step S1: processing threaded holes in the boss and the shell, installing the boss on the shell by inserting a positioning pin into the threaded holes, and arranging a soldering lug between the boss and the shell to obtain a component to be welded;

step S2: placing the welding tool in a hearth, heating the welding tool along with the furnace, and placing the component to be welded in the step S1 on the welding tool for furnace brazing when the temperature in the hearth rises to the welding temperature;

step S3: and (3) carrying out post-welding treatment on the workpiece obtained after furnace brazing, wherein the post-welding treatment process comprises the steps of cleaning brazing flux residues and welding slag and sand blasting.

Preferably, the positioning pin is made of a carbon arc gouging carbon rod.

Preferably, in step S2, before the assembly to be welded is placed in the furnace, the flux is prepared into a paste with acetone and coated at the weld joint position.

Preferably, in step S1, the positioning pin includes a threaded portion and a compression head; when the boss is installed on the shell, the thread part is in threaded connection with the boss and the threaded hole in the shell, and the pressing head presses the boss. The locating pin is formed by integrally turning the threaded part and the pressing head.

Preferably, in step S3, the method for cleaning flux residues and welding slag includes: and (3) putting the workpiece obtained after the brazing in the furnace into 10% citric acid, boiling for 15-20 min, brushing brazing flux residues and welding slag on the surface of the workpiece by using a steel wire brush, and finally washing the surface of the workpiece and a welding seam by using flowing clear water.

Preferably, in the step S3, before the sand blasting, the workpiece is placed in an oven at 100 ℃ for 1 hour to be dried.

Preferably, in step S1, the locating pin is stored in a drying cylinder, and if the locating pin is damp, the locating pin is placed in an oven at 100 ℃ for heat preservation for 1 hour and then used.

Preferably, in step S2, the welding tool includes a backing plate, an arc-shaped groove is provided on the backing plate, and the diameter of the arc-shaped groove matches with the outer diameter of the housing.

Further, the welding tool further comprises a cushion block; the cushion block is supported below the base plate, so that the component to be welded is positioned at the center of the hearth; the base plate and the cushion block are both made of mullite materials.

The invention has the following beneficial effects:

(1) according to the invention, the boss is fixedly arranged on the shell by the positioning pin, and the fixing mode of the positioning pin is adopted to replace the steel wire bundling and fixing mode in the traditional process, so that the defect that the steel wire bundling and positioning are difficult to slip and need to be repeatedly operated is avoided, the assembly time is shortened, and the efficiency is improved; in addition, the phenomena of discontinuous welding seams and welding leakage caused by loose expansion of steel wires in the welding process and loose positioning of components are avoided; the method avoids the increase of surface pollution caused by carbonization in the welding process of the steel wire, reduces the cleaning strength after welding, reduces the cleaning difficulty of the subsequent silver plating process, and thus improves the silver plating quality.

(2) In the invention, the positioning pin is prepared by adopting a carbon arc gouging carbon rod material, the main component of the positioning pin is graphite, and the melting point is as high as 3800 ℃, so that the positioning pin has strong high temperature resistance, is not melted in the welding process and does not pollute parts; the thermal expansion coefficient is small, the toughness is good, the processing is easy, and the welding process can not affect the threaded hole; the chemical property is stable, and the welding process can not generate chemical reaction with parts and welding flux, and can not cause adhesion; after the welding is finished, the positioning pin is easily taken out by a bench worker, and the threaded hole is not damaged.

(3) When the welding tool provided by the invention is used for furnace brazing, argon does not need to be filled in the welding process, and the aim of saving argon is achieved. In addition, the whole welding tool is arranged in the hearth to be heated along with the furnace, so that the time required by welding heating is effectively reduced, and the welding efficiency is improved.

(4) The invention adopts acetone to prepare the soldering flux, fully utilizes the effect of removing oil stain by the acetone, can inhibit the oxidation phenomenon of activated elements generated by the solder in the welding process, can ensure the weldability of the solder, and further ensures the welding quality.

(5) After welding, sand blasting is carried out, so that pollutants such as oxides, welding slag, soldering flux and the like remained on the surface of the welded part can be effectively removed, and residues on the surface before silver plating are better ensured.

(6) The boss and the soldering lug are fixed by the positioning pin, the operation is simple and convenient, the assembly time is shortened, the average assembly time is shortened from 20min to 8min, the one-time qualification rate is improved to be more than or equal to 98%, and the repair welding probability of flame brazing is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic structural view of a lead brass cavity component;

FIG. 2 is a schematic structural view of a boss fixed to a housing by steel wires in a conventional process;

FIG. 3 is a schematic structural view of the boss and the soldering lug of the present invention when they are fixed by the positioning pin;

FIG. 4 is a schematic structural view of the boss and the soldering lug of the present invention after being fixed to the housing by the positioning pin;

FIG. 5 is a schematic view of the position of the components to be welded in the furnace;

FIG. 6 is a schematic structural view of a backing plate in the welding tool of the present invention;

description of reference numerals: 10-a housing; 20-boss; 201-a first boss; 202-a second boss; 30-a threaded hole; 40-positioning pins; 401-a threaded portion; 402-a compression head; 50-soldering lug; 60-welding a tool; 61-a backing plate; 611-an arc-shaped groove; 62-cushion block; 70-furnace chamber.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

As shown in fig. 1, the structural schematic diagram of a lead brass cavity component is shown, the lead brass cavity component is made of lead brass, and the structure includes a housing 10 and bosses 20 welded on the housing 10, and the bosses 20 are respectively provided with a threaded hole 30 communicated to an inner cavity of the housing 10. The boss 20 comprises a first boss 201 and a second boss 202, the number of the first bosses 201 is one, and the first bosses are welded on the outer surface of the shell 10 near the left end; the number of the second bosses 202 is two symmetrically disposed on the surface of the housing 10. Fig. 2 is a schematic structural diagram of a conventional process in which a boss is fixed by being bound to a housing by using a steel wire.

Fig. 3 and 4 are schematic structural diagrams illustrating the boss and the soldering lug of the present invention after being fixed to the housing by the positioning pin. A brazing processing method in a lead brass cavity furnace comprises the following steps:

step S1: processing threaded holes 30 on the boss 20 and the shell 10, installing the boss 20 on the shell 10 by inserting positioning pins 40 into the threaded holes 30, and arranging soldering lugs 50 between the boss 20 and the shell 10 to obtain a component to be welded; the positioning pin 40 is made of a carbon arc gouging carbon rod;

step S2: placing the welding tool 60 in the furnace chamber 70 and raising the temperature along with the furnace, and placing the component to be welded in the step S1 on the welding tool 60 for furnace brazing when the temperature in the furnace chamber 70 rises to the welding temperature;

step S3: and (3) carrying out post-welding treatment on the workpiece obtained after furnace brazing, wherein the post-welding treatment process comprises the steps of cleaning brazing flux residues and welding slag and sand blasting. After welding, sand blasting is carried out, pollutants such as oxides, welding slag, soldering flux and the like remained on the surface of the welded part can be effectively removed, residues on the surface of the silver-plated part are better guaranteed to be free, repair is reduced, and the production period is guaranteed.

In this embodiment, before the assembly to be welded is put into the furnace, the flux is prepared into a paste with acetone and coated at the weld position in step S2.

In the present embodiment, in step S1, the positioning pin 40 includes a threaded portion 401 and a pressing head 402; when the boss 20 is mounted on the housing 10, the threaded portion 401 is in threaded connection with the boss 20 and the threaded hole 30 on the housing 10, and the pressing head 402 presses the boss 20.

In the present embodiment, the positioning pin 40 is integrally turned by the threaded portion 401 and the pressing head 402.

In this embodiment, in step S3, the method for cleaning the flux residue and the welding slag includes: and (3) putting the workpiece obtained after the brazing in the furnace into 10% citric acid, boiling for 15-20 min, brushing brazing flux residues and welding slag on the surface of the workpiece by using a steel wire brush, and finally washing the surface of the workpiece and a welding seam by using flowing clear water.

In this embodiment, in step S3, before the sandblasting, the workpiece is placed in an oven at 100 ℃ and kept warm for 1h to be dried.

In this embodiment, in step S1, the positioning pin 40 is stored in a drying cylinder, and if the positioning pin 40 is damp, the positioning pin is placed in an oven at 100 ℃ and kept warm for 1 hour before being used.

In this embodiment, in step S2, the welding tool includes a backing plate 61, an arc-shaped groove 611 is provided on the backing plate 61, and a diameter of the arc-shaped groove 611 matches with an outer diameter of the housing 10. During welding, treat that the welded subassembly is placed in arc groove 611, can effectively avoid treating that the welded subassembly takes place to rock, guarantee welding quality. The welding tool further comprises a cushion block 62; the cushion block 62 is supported below the backing plate 61, so that the components to be welded are located at the center of the hearth 70, the components to be welded are heated uniformly, and the welding quality is further improved. The backing plate 61 and the cushion block 62 are both made of mullite material, and the mullite has good high-temperature resistance and meets the requirement of brazing in a furnace.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.