CN116190968B - Flangeless soft and hard waveguide welding method - Google Patents

Abstract

The invention discloses a flangeless soft and hard waveguide welding method, which comprises the steps of inserting a soft waveguide into the first end of a welding clamp, and welding the soft waveguide with the first end of the welding clamp; silver plating is carried out on the combination body formed by welding the soft waveguide and the welding clamp and the hard waveguide; inserting the silver-plated hard waveguide into the second end of the silver-plated welding clamp, and welding the hard waveguide with the second end of the welding clamp; be equipped with the spacer between welding clamp's first end and the second end, soft waveguide mouth and hard waveguide mouth laminate in the spacer both sides respectively. The invention realizes the reliable connection of the soft waveguide and the hard waveguide and improves the welding quality.

Description

A flange-free soft and hard waveguide welding method

Technical Field

The invention belongs to the field of aerospace manufacturing, relates to a method for processing aerospace microwave waveguide products, and specifically relates to a method for welding flange-free soft and hard waveguides.

Background Art

The flangeless waveguide assembly is a whole waveguide assembly formed by connecting a clamp and a single waveguide segment together, as shown in Figure 1. It has good weight and space reduction characteristics and is extremely important for communication satellites and high-throughput satellites. Due to the dense and compact waveguide layout on high-throughput communication satellites, there is almost no adjustable range when the waveguide is installed. In order to ensure the accuracy of the waveguide interface, the flangeless waveguide structure has high requirements for dimensional accuracy; in addition, when the flangeless waveguide is installed, if there is a deviation in the waveguide dimensional accuracy, the waveguide is installed with stress, which may cause hidden dangers in subsequent vibration tests and applications.

If a section of soft waveguide is connected to the entire section of flangeless waveguide, as shown in Figure 2, the stress caused by the installation of the waveguide due to shape and position deviation can be effectively eliminated during the waveguide loading process, and the requirements for the structural dimensional accuracy of the waveguide after welding can also be reduced.

As a microwave passive product, the flangeless waveguide assembly has the inner cavity of the waveguide as the main working surface. Generally, silver plating is used to improve the waveguide conductivity index. The flangeless waveguide assembly is generally a long and multi-bend structure. The current silver plating technology cannot guarantee the quality of the silver plating layer of the entire flangeless waveguide inner cavity. Therefore, the entire waveguide is generally split into individual waveguide segments, and then the waveguide segments are silver plated and soldered together. This method is difficult to process in the secondary assembly process. In addition, the different cross-sectional shapes of the soft and hard waveguide ports result in gaps in the four corners of the aligned end faces of the soft and hard waveguide ports. In order to ensure the welding quality, the gaps in the four corners of the aligned end faces can only be filled with solder. Due to the corrugated spiral structure of the soft waveguide, the excess solder is very easy to flow into the waveguide cavity during soldering, causing the cross-sectional size of the waveguide cavity to change, affecting the waveguide conductivity index.

Summary of the invention

The purpose of the present invention is to overcome the above-mentioned defects and provide a flange-less soft and hard waveguide welding method, which solves the technical problem that the solder easily flows into the waveguide cavity during welding due to the different cross-sectional shapes of the waveguide mouth in the traditional welding method. The present invention realizes the reliable connection of the soft waveguide and the hard waveguide and improves the welding quality.

In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

According to the different cross-sectional shapes of the soft waveguide and the hard waveguide, the present invention designs a clamp structure suitable for the welding of the soft and hard waveguides, and designs a spacer structure in the middle of the clamp to transition the elliptical interface of the soft waveguide and the rectangular interface of the hard waveguide. During welding, the soft and hard waveguide ports are tightly fitted on the spacer to prevent the solder from flowing into the waveguide cavity. The welding method is determined according to the soft and hard waveguide and the clamp structure, and the soft waveguide is welded to the clamp by a hard soldering method. After silver plating, the soft waveguide is welded to the hard waveguide by a soft soldering method to ensure the strength and quality of the weld. Infrared temperature control is adopted during the welding process. By changing the surface state of the temperature measuring point and determining the temperature measuring position, the state of the temperature measuring point during the welding process is ensured to be stable. By temperature compensation, the temperature of the temperature measuring point position is consistent with the temperature at the weld, the accuracy of the temperature control of the infrared temperature measuring device is improved, and the purpose of accurately controlling the welding temperature is achieved, and the silver-plated layer is prevented from changing color, bubbling or falling off due to the excessively high welding temperature, and the silver-plated layer and the weld quality of the waveguide welding are ensured.

A flange-free soft and hard waveguide welding method, comprising:

S1 inserts the flexible waveguide into the first end of the welding clamp, and welds the flexible waveguide to the first end of the welding clamp;

S2 silver-plating the assembly formed by welding the waveguide and the welding clamp and the hard waveguide;

S3 inserts the silver-plated hard waveguide into the second end of the silver-plated welding clamp, and welds the hard waveguide to the second end of the welding clamp;

A spacer is arranged between the first end and the second end of the welding clamp, and the soft waveguide opening and the hard waveguide opening are respectively attached to two sides of the spacer.

Further, the inner surface profile of the first end of the welding clamp matches the outer surface profile of the soft waveguide, and the inner surface profile of the second end of the welding clamp matches the outer surface profile of the hard waveguide;

The depth of the soft waveguide inserted into the first end of the welding clamp is 0.5 mm to 1 mm, and the depth of the hard waveguide inserted into the second end of the welding clamp is 3 to 6 mm;

A gap of 0.03mm to 0.1mm is provided between the inner surface of the first end of the welding clamp and the outer surface of the soft waveguide, and a gap of 0.05mm to 0.15mm is provided between the inner surface of the second end of the welding clamp and the outer surface of the hard waveguide.

Furthermore, the thickness of the spacer of the welding clamp is 1 to 2 mm;

The size of the central opening of the spacer is consistent with the size of the inner cavity of the hard waveguide, and the four corners of the central opening of the spacer are arc structures.

Furthermore, the material of the welding clamp is brass H62.

Furthermore, a welding stop is provided on the outer surface of the hard waveguide, and when the welding stop is clamped into the second end of the welding clamp, the consistency of the welding gap around it is ensured.

Furthermore, in step S1, the flexible waveguide is welded to the first end of the welding clamp by using a brazing process;

In step S3, the hard waveguide is welded to the second end of the welding clamp by using a soft soldering process.

Furthermore, in step S1, the flexible waveguide is welded to the first end of the welding clamp, using silver-copper solder at a welding temperature of 610-630° C.;

In step S3, when the hard waveguide is welded to the second end of the welding clamp, lead-tin-silver solder is used, and the welding temperature is 310-330°C.

Furthermore, in step S3, during the welding of the hard waveguide to the second end of the welding clamp, an infrared thermometer is used to obtain temperature information of the weld area in real time, and the welding temperature is controlled to be 310-330° C. according to the temperature information.

Furthermore, the method of using an infrared thermometer to obtain temperature information of the weld area in real time and controlling the welding temperature to 310-330° C. according to the temperature information includes:

S3.1 Use the outer surface of the hard waveguide 5mm to 10mm away from the upper end of the weld as the temperature measurement point of the infrared thermometer;

S3.2 Before welding the hard waveguide to the second end of the welding clamp, place the solder at the weld, heat the weld area, align the infrared thermometer with the temperature measurement point, and record the temperature information T ₁ displayed by the infrared thermometer when the solder melts;

S3.3 Calculate the difference △T between _T1 and the theoretical melting temperature _T2 of the solder;

S3.4 applies △T compensation to the infrared thermometer;

During the welding process of S3.5 hard waveguide and the second end of the welding clamp, align the infrared thermometer with the temperature measuring point, and the infrared thermometer displays the actual temperature information of the welding seam area;

S3.6 Control the welding temperature to 310-330℃ according to the actual temperature information of the weld area.

Furthermore, the temperature measuring points on the outer surface of the hard waveguide are coated with black matte paint.

Compared with the prior art, the present invention has at least one of the following beneficial effects:

(1) The present invention creatively proposes a flange-free soft and hard waveguide welding method, which realizes the connection between the soft waveguide and the hard waveguide, is conducive to eliminating the stress caused by the installation of the waveguide due to the shape and position size deviation, and also reduces the requirements for the structural size accuracy of the waveguide after welding;

(2) The present invention designs a clamp structure and a joint form suitable for connecting the soft and hard waveguides according to the different shapes of the soft waveguide opening and the hard waveguide opening, reasonably realizes the connection between the elliptical interface of the soft waveguide and the rectangular interface of the hard waveguide, and studies the welding method in combination with the materials and clamp structure of the soft waveguide and the hard waveguide, thereby realizing a reliable connection between the soft waveguide and the hard waveguide;

(3) The present invention uses two brazing processes to connect the soft waveguide and the hard waveguide to the clamp, respectively. The welding process ensures the weld strength of the soft and hard waveguides and the quality of the waveguide inner cavity, thereby improving the welding quality of the soft waveguide and the hard waveguide;

(4) The present invention can accurately control the weld temperature during hard waveguide welding, thereby avoiding the impact of inaccurate high-frequency induction brazing temperature control on the quality of the weld and the waveguide silver plating layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a flangeless waveguide assembly;

FIG2 is a schematic diagram of a flangeless waveguide assembly with a flexible waveguide section;

FIG3 is a schematic diagram of a hard waveguide in a flangeless waveguide assembly;

FIG4 is a schematic diagram of a flexible waveguide in a flangeless waveguide assembly;

FIG5 is a schematic diagram of the welding clamp structure of the present invention, wherein (a) is a schematic diagram of the first end of the welding clamp, (b) is a schematic diagram of the second end of the welding clamp, and (c) is a schematic diagram of the cross-section of the welding clamp;

FIG6 is a schematic diagram of the connection between a soft and hard waveguide according to the present invention, wherein (a) is an overall schematic diagram and (b) is a cross-sectional schematic diagram;

FIG7 is a schematic diagram of the brazing of the flexible waveguide and the clamp of the present invention;

FIG8 is a schematic diagram of the present invention of the soft waveguide and the clamp being hard-soldered and silver-plated and then soft-soldered with the hard waveguide;

FIG9 is a flow chart of the soft and hard waveguide welding process of the present invention;

FIG10 is a schematic diagram of the locations of infrared temperature measurement points of the present invention;

FIG11 is a schematic diagram of a hard waveguide port welding stop according to the present invention;

FIG12 is a schematic diagram of the clamp design in an embodiment of the present invention, wherein (a) is a schematic diagram of the first end of the welding clamp, (b) is a schematic diagram of the cross-section of the welding clamp, and (c) is a schematic diagram of the second end of the welding clamp;

FIG13 is a schematic diagram of the welding assembly of the flexible waveguide of the present invention, wherein (a) is a schematic diagram of the assembly position, and (b) is a schematic diagram of the assembly completion;

FIG14 is a schematic diagram of the welding of a flexible waveguide according to the present invention;

FIG15 is a schematic diagram of the hard waveguide welding assembly of the present invention, wherein (a) is a schematic diagram of the assembly position, and (b) is a schematic diagram of the assembly completion;

FIG16 is a schematic diagram of hard waveguide welding of the present invention;

In the figure, 1 is hard waveguide, 2 is soft waveguide, 3 is welding clamp soft waveguide welding end groove, 4 is welding clamp hard waveguide soft soldering end cavity, 5 is spacer, 6 is welding clamp, 7 is black matte paint, 8 is infrared temperature measuring point, 9 is welding stop, 10 is soft waveguide mouth end face, 11 is induction heating coil, 12 is non-magnetic tooling, 13 is hard waveguide mouth end face, 14 is infrared thermometer cursor lower edge.

DETAILED DESCRIPTION

The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

The present invention provides a method for welding a flangeless soft and hard waveguide. According to the different shapes of the soft waveguide port and the hard waveguide port, a clamp structure and a joint form suitable for connecting the soft waveguide and the hard waveguide are designed to reasonably realize the connection between the soft waveguide elliptical interface and the hard waveguide rectangular interface, and the welding method is studied in combination with the materials and clamp structures of the soft waveguide and the hard waveguide. The soft and hard waveguides are connected to the clamps using two brazing processes respectively. The welding process ensures the weld strength of the soft and hard waveguides and the quality of the waveguide inner cavity, and realizes the reliable connection of the soft waveguide and the hard waveguide, which can be used to manufacture flangeless waveguide components with soft waveguides. At the same time, the present invention also realizes the precise control of the weld temperature during the welding of the hard waveguide, so as to avoid the inaccurate control of the high-frequency induction brazing temperature affecting the quality of the weld and the silver-plated layer of the waveguide. The present invention studies the welding method in combination with the materials and clamp structures of the soft waveguide and the hard waveguide, and ensures the quality of the weld and the silver-plated layer by precisely controlling the welding temperature.

1. Soft waveguide welding clamp structure design

First of all, as a microwave passive product, the quality of the waveguide inner cavity directly affects the electrical performance indicators of the waveguide, that is, during welding, the solder is not allowed to flow into the waveguide inner cavity to change the cross-sectional size of the inner cavity or form excess material. Therefore, when designing the soft and hard waveguide welding clamp structure, a corresponding structure must be set to prevent the solder from flowing into the waveguide inner cavity during subsequent welding.

In addition, since the shape of the hard waveguide mouth is rectangular, as shown in Figure 3, and the shape of the soft waveguide mouth is elliptical, and the outer wall of the soft waveguide is a bellows spiral structure, as shown in Figure 4, the soft and hard waveguide welding clamp structure design needs to adapt to the waveguide mouth shapes of the two waveguides respectively, and needs to transition the structural differences of the two waveguide mouths. At the same time, it is also necessary to ensure the welding gap between the outer walls of the two waveguides and the clamp to ensure that the solder fills the weld under the capillary action of the weld.

Considering the high-quality welding requirements of the inner cavity of the waveguide without flange (the solder is not allowed to flow into the inner cavity of the waveguide) and the reasonable transition requirements of the welds of the soft and hard waveguides (there are structural differences between the two waveguide ports), the schematic diagram of the welding clamp structure design and the schematic diagram of the soft and hard waveguide connection are shown in Figures 5 and 6.

The structural design of the welding clamp is as follows:

1) The connection end of the welding clamp 6 and the flexible waveguide 2 is designed with a depth of 0.5mm to 1mm. The groove 3 at the welding end of the welding clamp flexible waveguide is designed with a depth of 0.5mm to 1mm. The inner contour of the cavity is matched with the outer shape of the flexible waveguide 2, and a welding gap of 0.03mm to 0.1mm is added. The concave cavity 0.5mm to 1mm is the length of the flexible waveguide 2 inserted into the clamp.

2) A welding clamp hard waveguide welding end cavity 4 is set at the connection end between the welding clamp 6 and the hard waveguide 1. The inner cavity size is matched with the hard waveguide shape to control the welding gap after assembly with the waveguide tube to be 0.05mm~0.15mm, and the hard waveguide 1 is inserted into the clamp with a length of 3~6mm.

3) An annular spacer 5 structure is designed in the middle of the clamp, the thickness of the spacer is 1mm, the size of the middle opening of the spacer 5 matches the size of the hard waveguide inner cavity section, and the chamfer R1. When welding and assembling, the soft and hard waveguides are inserted into the clamp and the soft waveguide end face 10 and the hard waveguide end face 13 are closely attached to the spacer 5, so as to solve the problem of solder flowing into the waveguide inner cavity due to the different cross-sectional shapes of the two waveguide ports when welding the soft and hard waveguides.

4) Since the flexible waveguide material is brass and the flexible waveguide welding requires brazing, the clamp material is set to brass H62.

2. Soft and hard waveguide welding method

At present, the waveguide that cannot be blued (excluding soft waveguide) is formed by connecting the silver-plated clamp and a single waveguide segment together by soft soldering. Considering the different shapes of the soft and hard waveguide openings, it is difficult to complete the welding of the soft and hard waveguides simultaneously. Therefore, two welding methods are required. After the welding of the soft waveguide and the clamp is completed, the soft waveguide and the clamp are silver-plated as a whole and then welded together with the hard waveguide.

Due to the long cavity and multi-bend structure of the flangeless waveguide, if the waveguide is welded by hard soldering and then silver-plated as a whole, the current silver plating process cannot meet the quality requirements of silver plating in the inner cavity of the flangeless waveguide, so each waveguide section can only be silver-plated before welding.

Considering that the welding gap formed after the outer wall of the soft waveguide corrugated structure is inserted into the clamp is uneven, which is not conducive to the solder filling the weld under the capillary action of the weld and forming more defects, the overlap (welding) depth of the soft waveguide and the clamp is as small as possible, and the welding strength of the soft waveguide and the clamp must be guaranteed at the same time. Therefore, the soft waveguide and the clamp are welded together by brazing (see Figure 7). The brazing process is used to improve the weld strength between the soft waveguide and the clamp, and a temperature difference is formed during the secondary welding of the clamp and the hard waveguide to prevent the solder from melting and flowing into the inner cavity of the soft waveguide and affecting the weld quality. The solder for brazing the soft waveguide and the clamp is silver-copper solder, and the welding temperature is 610-630°C.

The welding strength of soft soldering is relatively low. To meet the welding strength requirements, the area of the weld must be increased, that is, the depth of the waveguide inserted into the clamp must be increased. However, the corrugated structure of the soft waveguide forms an uneven welding gap when inserted into the clamp, which is very likely to produce welding defects such as bubbles and does not meet the weld quality requirements. The uneven welding gap easily causes the solder to flow into the inner cavity of the waveguide during welding, so the soft waveguide and the clamp are not suitable for soldering. The material of the soft waveguide is copper alloy and the material of the hard waveguide is aluminum alloy. After the two are welded together by the hard soldering process, due to the difference in the materials of the two, the same electroplating silver process cannot be used for silver plating.

After the soft waveguide and the clamp are hard soldered, the soft waveguide and the clamp are silver-plated as a whole, and then soldered to the silver-plated hard waveguide by soft soldering (see Figure 8), using lead-tin-silver solder at a soldering temperature of 310-330°C. The welding process flow of the flangeless soft and hard waveguide is shown in Figure 9.

3. Precise control of waveguide soldering temperature

After the soft waveguide and the clamp are silver-plated as a whole, they are welded to the silver-plated hard waveguide by high-frequency induction soldering, and the welding temperature is 310-330°C. However, the maximum tolerable temperature of the silver-plated layer of the waveguide is 340°C in a short time. The safety margin of the welding temperature after the waveguide is silver-plated is low. Therefore, the welding temperature must be accurately controlled during the welding process to prevent the welding temperature from exceeding the heat-resistant temperature of the silver-plated layer of the waveguide, causing the silver-plated layer to bubble or even peel off. The present invention adopts an infrared temperature control method, analyzes the characteristics of the waveguide coating and the welding structure, improves the accuracy of infrared temperature measurement, and feeds back the infrared temperature measurement signal to the high-frequency induction heating equipment to realize automatic control of the welding temperature, thereby achieving the purpose of accurately controlling the welding temperature.

Realize infrared precise control of weld temperature to prevent inaccurate temperature control of high-frequency induction brazing from affecting the quality of weld and waveguide silver plating layer.

1) Determination of surface status of infrared temperature measurement

Since the silver-plated layer on the surface of the waveguide has a high reflectivity to infrared rays, which affects the accuracy of infrared temperature measurement, in order to overcome the influence of the silver-plated surface on the infrared temperature measurement accuracy, a high-temperature resistant (＞350℃) black matte paint 7 is coated on the infrared temperature measurement point 8 to provide an ideal surface state for the infrared temperature measurement equipment, solve the problem that the reflection of infrared rays by the silver-plated surface of the waveguide affects the temperature measurement accuracy, and enable the infrared temperature measurement equipment to accurately measure the temperature of the welding area and control the power output of the high-frequency induction welding equipment, so as to achieve the purpose of accurate temperature measurement.

2) Determination of infrared temperature measurement position

During the welding process, the molten solder diffuses and flows along the weld area, causing the surface state of the outside of the clamp and the area near the weld to change. If the infrared temperature measuring point 8 is selected outside the clamp or near the weld, the outflowing solder covers or partially covers the infrared temperature measuring point area, causing the surface state of the infrared temperature measuring point area to change, resulting in inaccurate infrared real-time temperature measurement data, and the signal fed back to the induction welding machine will change, causing inaccurate heating temperature.

To solve this problem, the infrared temperature measurement point should be selected at a position where the surface state of the part is stable during the entire welding process. During waveguide welding, it is placed vertically in the induction heating coil 11. The overflowed solder flows downward under the action of gravity. The affected area on the upper part of the clamp weld is small, so the infrared temperature measurement point is selected at a relatively stable position 5mm to 10mm away from the upper end of the weld, as shown in Figure 10, to solve the problem of inaccurate temperature measurement caused by the change of the temperature measurement point interface during brazing, and ensure the accuracy of infrared temperature measurement during welding.

3) Temperature compensation method of infrared temperature measurement

Since the infrared temperature measuring point is at the upper end of the clamp weld, the temperature displayed here is not the actual temperature of the weld area. In order to make the infrared thermometer display the actual welding temperature, place the solder at the weld before setting the welding temperature and start heating the welding area. When the solder melts, record the temperature displayed by the infrared thermometer at this time. Because the solder melting temperature is a theoretical standard value, the difference between the solder melting temperature and the temperature displayed by the infrared thermometer is compensated to the infrared temperature control device. At this time, the temperature displayed at the infrared temperature measuring point is the actual temperature of the weld area.

The difference between the displayed temperature and the temperature at the weld is compensated in the displayed temperature of the infrared thermometer, and temperature compensation is performed through the infrared temperature control program, so that the infrared thermometer can display the actual welding temperature of the weld area during the welding process, thereby achieving the purpose of accurately controlling the welding temperature.

Example

This embodiment includes the following steps:

1. Clamp design and processing

(1) Since the hard waveguide 1 is extruded, the cross-sectional dimensions of the waveguide have certain errors. In order to obtain a uniform welding gap, a 0.1 mm × 5 mm welding stop 9 is processed on the outer surface of the hard waveguide mouth. 0.1 mm is the height of the stop from the outer surface of the waveguide, and 5 mm is the distance from the stop to the waveguide mouth, as shown in Figure 11. The specifications of the soft and hard waveguides are measured (taking BJ120 hard waveguide as an example, the outer cross-sectional dimensions of the hard waveguide are about 21.5 mm × 11.52 mm), and the clamp, the groove dimensions of the soft waveguide end, the middle spacer, and the inner cavity dimensions of the hard waveguide welding end are designed and processed, as shown in Figure 12.

(2) Clamp material: Brass H62.

(3) The size of the groove 3 at the welding end of the flexible waveguide of the welding clamp is 22.5×11.85 mm, which matches the shape of the flexible waveguide 2.

2. Brazing of soft waveguide and clamp

(1) Welding equipment: The welding equipment is a high frequency induction welding machine.

(2) Solder: silver-copper solder (BAg40CuZnCdNi).

(3) Brazing flux: silver solder paste.

(4) Cleaning before welding: Use alcohol to clean the clamp and flexible waveguide.

(5) Assembly: Insert the flexible waveguide vertically into the groove of the clamp so that the end face of the flexible waveguide fits tightly against the clamp spacer, as shown in Figure 13.

(6) Welding

① Place the assembled flexible waveguide and clamp on the non-magnetic tooling 12 and put it into the induction heating coil, as shown in FIG14 .

② Apply a layer of flux (silver solder paste) on the weld position.

③ Start heating, and when the temperature reaches the brazing temperature (610-620℃), hold the silver-copper (BAg40CuZnCdNi) welding wire and fill it into the weld along the weld until a full brazing fillet is formed on the outer edge of the weld. Stop heating and wait for the parts to cool.

3. Silver plating

The welded soft waveguide, clamp and hard waveguide are surface-plated with silver, Al/Ep.Ag16.At(Ct.P).

4. Hard waveguide soldering

(1) Apply black paint: Apply a layer of black high-temperature resistant matte paint with a width of 8 to 10 mm evenly on the hard waveguide section at the upper end of the clamp, 5 mm away from the weld at the upper end of the clamp. Let it stand for about 10 minutes until the black paint is dry.

(2) Welding equipment: The welding equipment is a high frequency induction welding machine.

(3) Solder: lead-tin-silver solder.

(4) Flux: non-corrosive flux.

(5) Assembly: Insert the hard waveguide vertically into the groove of the clamp so that the end face of the hard waveguide fits tightly against the clamp block, as shown in Figure 15.

(6) Welding

① Place the assembled parts vertically into the induction heating coil with the hard waveguide on top, turn on the infrared thermometer cursor and align it with the position coated with black paint. The lower edge of the infrared thermometer cursor 14 should be aligned with the lower boundary of the black matte paint 7 to ensure the consistency of the infrared thermometer temperature measurement position and the weld position during each welding, thereby ensuring the accuracy and consistency of the temperature compensation value ▽t, as shown in Figure 16. Set the welding parameters of the induction welder.

② Apply a layer of flux evenly on the weld.

③ Start heating, and when the temperature reaches the brazing temperature (310-330°C), hold the lead-tin-silver (PnSnAg5.5-2.5) welding wire and fill it into the weld until a full brazing fillet is formed on the outer edge of the weld. Stop heating and wait for the parts to cool.

The invention discloses a flangeless soft and hard waveguide welding method. According to different shapes of a soft waveguide port and a hard waveguide port, a clamp structure and a joint form suitable for connecting the soft and hard waveguides are designed to reasonably realize the connection between the soft waveguide elliptical interface and the hard waveguide rectangular interface. The welding method is studied in combination with the materials and clamp structures of the soft waveguide and the hard waveguide, and reliable connection of the soft waveguide and the hard waveguide is realized. Meanwhile, by improving the surface state of the temperature measuring point, determining the position of the infrared temperature measuring point, and compensating the temperature of the temperature measuring point and the welding position, the accuracy of temperature control of the infrared temperature control device is improved, and precise control of the temperature of the welding process is realized, thereby ensuring the weld strength of the soft and hard waveguides and the quality of the waveguide inner cavity. The invention can be used for processing and manufacturing flangeless waveguide components with soft waveguides.

The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims (8)

1. A flangeless soft and hard waveguide welding method, characterized by comprising: S1 inserts the flexible waveguide into the first end of the welding clamp, and welds the flexible waveguide to the first end of the welding clamp; S2 silver-plating the assembly formed by welding the waveguide and the welding clamp and the hard waveguide; S3 inserts the silver-plated hard waveguide into the second end of the silver-plated welding clamp, and welds the hard waveguide to the second end of the welding clamp; A spacer is provided between the first end and the second end of the welding clamp, and the soft waveguide opening and the hard waveguide opening are respectively attached to two sides of the spacer; The depth of the soft waveguide inserted into the first end of the welding clamp is 0.5 mm to 1 mm, and the depth of the hard waveguide inserted into the second end of the welding clamp is 3 to 6 mm; The thickness of the spacer of the welding clamp is 1 to 2 mm; The size of the central opening of the septum is consistent with the size of the inner cavity of the hard waveguide, and the four corners of the central opening of the septum are arc structures; In step S1, the flexible waveguide is welded to the first end of the welding clamp by using a brazing process; In step S3, the hard waveguide is welded to the second end of the welding clamp by using a soft soldering process. 2. A flangeless soft and hard waveguide welding method according to claim 1, characterized in that the inner surface profile of the first end of the welding clamp matches the outer surface profile of the soft waveguide, and the inner surface profile of the second end of the welding clamp matches the outer surface profile of the hard waveguide; A gap of 0.03mm to 0.1mm is provided between the inner surface of the first end of the welding clamp and the outer surface of the soft waveguide, and a gap of 0.05mm to 0.15mm is provided between the inner surface of the second end of the welding clamp and the outer surface of the hard waveguide. 3. A flange-less soft and hard waveguide welding method according to claim 1, characterized in that the material of the welding clamp is brass H62. 4. A flange-free soft and hard waveguide welding method according to claim 1, characterized in that a welding stop is provided on the outer surface of the hard waveguide, and when the welding stop is clamped into the second end of the welding clamp, the consistency of the welding gap around it is ensured. 5. A flange-free soft and hard waveguide welding method according to claim 1, characterized in that, in step S1, the soft waveguide is welded to the first end of the welding clamp, silver-copper solder is used, and the welding temperature is 610-630°C; In step S3, when the hard waveguide is welded to the second end of the welding clamp, lead-tin-silver solder is used, and the welding temperature is 310-330°C. 6. A flange-free soft and hard waveguide welding method according to claim 1, characterized in that, in step S3, during the process of welding the hard waveguide to the second end of the welding clamp, an infrared thermometer is used to obtain the temperature information of the weld area in real time, and the welding temperature is controlled to 310-330°C according to the temperature information. 7. A flangeless soft and hard waveguide welding method according to claim 1, characterized in that an infrared thermometer is used to obtain temperature information of the weld area in real time, and the method of controlling the welding temperature to 310-330°C according to the temperature information comprises: S3.1 Use the outer surface of the hard waveguide 5mm to 10mm away from the upper end of the weld as the temperature measurement point of the infrared thermometer; S3.2 Before welding the hard waveguide to the second end of the welding clamp, place the solder at the weld, heat the weld area, align the infrared thermometer with the temperature measuring point, and record the temperature information T1 displayed by the infrared thermometer when the solder melts; S3.3 Calculate the difference △T between T1 and the theoretical melting temperature T2 of the solder; S3.4 applies △T compensation to the infrared thermometer; During the welding process of S3.5 hard waveguide and the second end of the welding clamp, align the infrared thermometer with the temperature measuring point, and the infrared thermometer displays the actual temperature information of the welding seam area; S3.6 Control the welding temperature to 310-330℃ according to the actual temperature information of the weld area. 8. A flange-less soft and hard waveguide welding method according to claim 7, characterized in that the temperature measuring points on the outer surface of the hard waveguide are coated with black matte paint.