Thermal power carbon brush body copper plating and wire welding process

Abstract

The invention discloses a thermal power carbon brush body copper plating and wire welding process, and relates to the technical field of thermal power carbon brushes. The carbon brush comprises a carbon brush body, the end face of the carbon brush body is of an arc-shaped structure, arc grooves which are evenly distributed are formed in the arc-shaped end face of the carbon brush body, the direction of the arc grooves is parallel to the rotation direction of the sliding ring, and exhaust grooves are formed in the arc-shaped end face of the carbon brush body and are obliquely arranged. Two ends of the exhaust groove are respectively arranged on the inner sides of diagonal corners of the arc-shaped end face of the carbon brush body. According to the invention, the problems that a carbon brush wire and a brush body of a slip ring chamber of a thermal generator set are in continuous high temperature, due to material characteristic difference and different expansion coefficients, microscopic distortion is found, high-temperature oxidation and local loosening occur at a wire riveting part, so that the connection resistance is in a multiplicative increasing trend, and the service life is prolonged can be effectively solved. The problem that the carbon brushes distributed on the surface of the slip ring are unevenly distributed due to annular airflow generated by the slip ring and the carbon brushes when the slip ring rotates rapidly is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal power carbon brush, and particularly relates to a copper plating and wire welding process for a thermal power carbon brush body. BACKGROUND

[0002] In view of the fact that the imported brand carbon brushes are used for a long time on large thermal power generating units in China, and the unknown factors of the domestic graphite material and the imported graphite material, and the short use history of the domestic excitation carbon brush, more use cases and experience are needed to prove the optimization and progress of the material and process.

[0003] The domestic carbon brush cannot meet the technical specification requirements of the thermal power generating unit in terms of the carbon material itself and the connection of the wire and the brush body.

[0004] Since the existing large thermal power generating unit carbon brush adopts a physical filling structure and a riveting fixing mode, the process technology causes the high temperature of the thermal power carbon brush in the operation of the slip ring excitation system, and the uneven current caused by the increased connection resistance.

[0005] Therefore, there is an urgent need in the market for a carbon brush assembly that is consistent in the connection of the excitation end and the steam end carbon brush body and the wire, solves the annular airflow formed by the friction between the carbon brush and the slip ring surface, and is stable and reliable under the hot state, so as to ensure that the carbon brush on the slip ring surface is in a relatively stable and uniform current state, and the unit can be continuously and safely operated. SUMMARY

[0006] The present application aims to solve the problems in the prior art and provides a copper plating and wire welding process for a thermal power carbon brush body.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: A thermal power carbon brush comprises a carbon brush body, the end face of the carbon brush body is in an arc shape, the arc-shaped end face of the carbon brush body is provided with arc grooves that are uniformly distributed, the direction of the arc grooves is parallel to the rotation direction of the slip ring, an exhaust groove is formed in the arc-shaped end face of the carbon brush body, the exhaust groove is inclined, and the two ends of the exhaust groove are located on the inner sides of the opposite angles of the arc-shaped end face of the carbon brush body.

[0008] As a kind of preferred of the present application: the carbon brush body is provided with sink groove on both sides, copper layer is plated in sink groove, wire slot is formed in the end of carbon brush body far from arc-shaped end face, wire slot extends to sink groove at one end, rivet is installed in sink groove, wire is wound on the outside of both ends of rivet, two wires extend to the outside of carbon brush body through two wire slots, first baffle is installed on the outside of one end of rivet, second baffle is installed on the outside of the other end of rivet, first baffle and second baffle press two wire ends in sink groove;One end of rivet is limited by first baffle, rivet is riveted and welded on the side of second baffle far from wire after penetrating through the center hole of second baffle.

[0009] As a kind of preferred of the present application: the first baffle is C-shaped structure, the second baffle is ring-shaped structure, tin paste is coated between second baffle, first baffle and copper layer of sink groove.

[0010] A copper plating and wire welding process for thermal power carbon brush body, comprising the following steps: S1: processing carbon brush body according to drawing; S2: making aluminum box, the size of aluminum box is matched with carbon brush body, carbon brush body is installed in aluminum box, and carbon brush body is placed in vacuum electric sputtering copper plating machine, and copper is plated on both sides of sink groove of brush body; S3: the product after copper plating is placed in self-made bottom arc wire drawing machine to complete bottom arc wire drawing, and arc groove is formed; S4: the bottom of the product after wire drawing is placed on grinding machine to process bottom exhaust groove with cutting piece; S5: after exhaust groove processing is completed, tin paste is evenly coated on the copper-plated surface of the sink groove of carbon brush body; S6: put in rivet, pass two wires through carbon brush top hole, and wind them on both sides of sink groove, then evenly coat tin paste on the wires in sink groove, then place bottom first baffle, evenly coat tin paste on first baffle, and then put second baffle on top, and then put in pre-pressing mold for pre-pressing; S7: after pre-pressing, the product is placed on riveting mold for height rivet locking and reinforcing, then the brush body is placed in high-frequency heating induction area; S8: start high-frequency heating equipment, start cooling circulation system, start temperature control system, monitor heating temperature, after welding is completed, wait for temperature to cool down, and then take out the product.

[0011] As a kind of preferred of the present application: in S2, the vacuum range of vacuum electric sputtering copper plating machine is between 3.5-2, current is 120-150A, voltage is 380V, temperature is 1000℃, and vacuum electric sputtering time is 20 minutes.

[0012] As a kind of preferred of the present application: the size of sink groove is φ16.0mm, and the thickness of copper plating is 0.01mm-0.015mm.

[0013] As a preferred of the present application: the width of the exhaust groove is 0.5mm.

[0014] As a preferred of the present application: in the S6, the pre-pressing degree is 5kg.

[0015] As a preferred of the present application: in the S7, the rivet locking reinforcing degree is 3kg, and the spin riveting is 2 seconds.

[0016] As a preferred of the present application: in the S8, after the heating temperature reaches 225℃, the constant temperature is kept for 5 seconds, the welding is completed, and the product is taken out after the temperature is cooled to below 150℃.

[0017] The beneficial effects of the present application are: 1. The present application can effectively alleviate the situation that the carbon brush lead and the brush body are twisted and deformed due to the difference in material properties and the different expansion coefficients under continuous high temperature, high-temperature oxidation and local loosening occur at the riveting position of the lead, and the coupling resistance increases several times, effectively solving the situation that the annular airflow generated by the rapid rotation of the slip ring and the carbon brush causes uneven distribution of the carbon brush shunt on the slip ring surface.

[0018] 2. The present application can make the arc-shaped end face of the carbon brush body more easily worn by friction at the initial stage of work, so that the end face of the carbon brush body is better matched with the slip ring, thereby ensuring the use effect.

[0019] 3. The excitation carbon brush of the present application has stable lead and brush body coupling resistance under thermal state, uniform current distribution of each carbon brush on the slip ring surface, and effectively reduces the high-frequency vibration of the 6#, 7#, 8# and 9# bearing bush of the large generator caused by temperature imbalance on the large shaft. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 The structure diagram of the thermal power carbon brush and the aluminum box is provided for the present application; Fig. 2 The structure diagram of the thermal power carbon brush is provided for the present application; Fig. 3 The structure diagram of the thermal power carbon brush structure separation is provided for the present application.

[0021] In the figure: 1-carbon brush body; 2-rivets; 3-second baffle; 4-groove; 5-opening; 6-aluminum box; 7-lead; 8-first baffle; 9-arc groove; 10-exhaust groove; 11-sink groove; 12-wire groove. DETAILED DESCRIPTION

[0022] The technical solutions of the present application will be further described in detail below in combination with specific embodiments.

[0023] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like component having the same or similar function is denoted by the same or like reference numerals throughout the attached drawing figures. The embodiments described below are exemplary only, are merely intended to teach one of ordinary skill in the art the way to make and use the present application, and should not be construed as a limitation of the present application. Embodiment 1

[0024] A thermal power carbon brush, as shown in Figs. 1-3 , comprises a carbon brush body 1, the end face of the carbon brush body 1 is arc-shaped structure, the arc-shaped end face of the carbon brush body 1 is provided with arc grooves 9 which are uniformly distributed, the direction of the arc grooves 9 is parallel to the rotating direction of the slip ring, the arc-shaped end face of the carbon brush body 1 is provided with exhaust grooves 10, the exhaust grooves 10 are inclined, and the two ends of the exhaust grooves 10 are respectively located on the inner side of the arc-shaped end face of the carbon brush body 1 which is diagonally opposite. By setting the exhaust grooves 10, the airflow can be guided during the rotation of the slip ring during work, so that it can be discharged from the end of the exhaust grooves 10, avoiding the formation of annular airflow between the slip ring and the carbon brush, overcoming the problem of excessive local resistance and excessive temperature caused by the annular airflow of the traditional carbon brush. By setting the arc grooves 9, the arc-shaped end face of the carbon brush body 1 can be more easily worn out at the beginning of work, so that the end face of the carbon brush body 1 can better fit the slip ring, thereby ensuring the use effect.

[0025] Wherein, the carbon brush body 1 is provided with a sink groove 11 on both sides, the sink groove 11 is plated with a copper layer, the carbon brush body 1 is provided with a wire groove 12 at one end away from the arc-shaped end face, one end of the wire groove 12 extends into the sink groove 11, a rivet 2 is installed in the sink groove 11, both ends of the rivet 2 are wrapped with wires 7, the two wires 7 extend to the outside of the carbon brush body 1 through the two wire grooves 12, a first baffle 8 is installed on one end of the rivet 2, a second baffle 3 is installed on the other end of the rivet 2, and the first baffle 8 and the second baffle 3 press the ends of the two wires 7 in the sink groove 11; one end of the rivet 2 is limited by the first baffle 8, and the other end of the rivet 2 is riveted and welded on the side of the second baffle 3 away from the wire 7 after penetrating through the center hole of the second baffle 3.

[0026] Wherein, the first baffle 8 is C-shaped structure, the second baffle 3 is ring-shaped structure, and the copper layer between the second baffle 3, the first baffle 8 and the sink groove 11 is coated with tin paste.

[0027] Wherein, when the carbon brush body 1 is plated with copper, an aluminum box 6 is used in cooperation, the aluminum box 6 is provided with a recess 4 on the side surface, and the recess 4 is provided with an opening 5 matched with the sink groove 11. Embodiment 2

[0028] A copper plating and wire welding process for a thermal power carbon brush body, as shown in Figs. 1-3 , comprises the following steps: S1: according to the drawing processing carbon brush main body 1 basic size; S2: make aluminum box 6, aluminum box 6 size and carbon brush main body 1 adapt, carbon brush main body 1 is loaded into aluminum box 6 and is placed in vacuum electric sputtering copper machine, the vacuum range is between 3.5-2, current 120-150A, voltage 380V, temperature 1000 DEG C, vacuum electric sputtering time 20 minutes copper is plated in the sink 11 of both sides of brush body, the size of sink 11 is φ16.0mm, and the copper plating thickness is 0.01mm-0.015mm; S3: the product is placed in the self-made bottom arc wire drawing machine to complete the bottom arc wire drawing, and the arc groove 9 is formed; S4: the product bottom after wire drawing is placed in the grinding machine with 0.5mm thickness cutting piece to process the bottom exhaust groove 10; S5: after the exhaust groove 10 processing is completed, the carbon brush main body 1 sink 11 copper surface is evenly smeared with tin paste (full coating, no bottom color is leaked); S6: put in the rivet 2, pass the carbon brush top via hole through the two wires 7, and the circular is wound on both sides of the sink 11, then the wire 7 in the sink 11 is evenly smeared with tin paste, then the first baffle 8 at the bottom is placed, the tin paste is evenly smeared on the first baffle 8, and then the second baffle 3 at the top is placed in the pre-pressing mold for pre-pressing, and the pre-pressing degree is 5 kg; S7: after pre-pressing, the product is placed on the riveting mold for height rivet locking and reinforcing (3 kg, spin riveting 2 seconds), then the brush body is placed in the high-frequency heating induction area; S8: start the high-frequency heating equipment, start the cooling circulation system, start the temperature control system, monitor the heating temperature, when the heating temperature reaches 225 DEG C, keep the temperature for 5 seconds, weld, and take out the product after the temperature cools to below 150 DEG C, and the welding is completed.

[0029] For the part not disclosed in the application, the skilled in the art can ensure the smooth implementation of the application based on common sense, normal thinking logic and prior art.

[0030] The above is only the preferred embodiment of the application, but the protection scope of the application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the application within the technical range disclosed by the application, which should be covered in the protection scope of the application.

Claims

1. A carbon brush for thermal power plants, characterized in that, The carbon brush body (1) includes an arc-shaped end face. The arc-shaped end face of the carbon brush body (1) is provided with uniformly distributed arc grooves (9). The direction of the arc grooves (9) is parallel to the rotation direction of the slip ring. An exhaust groove (10) is provided on the arc-shaped end face of the carbon brush body (1). The exhaust groove (10) is inclined and the two ends of the exhaust groove (10) are located on the inner side of the arc-shaped end face of the carbon brush body (1) at an angle.

2. The carbon brush for thermal power plants according to claim 1, characterized in that, The carbon brush body (1) has grooves (11) on both sides, and copper is plated in the grooves (11). A wire groove (12) is provided at the end of the carbon brush body (1) away from the arc end face. One end of the wire groove (12) extends into the groove (11). A rivet (2) is installed in the groove (11). Wires (7) are wrapped around both ends of the rivet (2). The two wires (7) extend through the two wire grooves (12) to the outside of the carbon brush body (1). A first baffle (8) is installed on the outside of one end of the rivet (2). A second baffle (3) is installed on the outside of the other end of the rivet (2). The first baffle (8) and the second baffle (3) press the ends of the two wires (7) together in the groove (11). One end of the rivet (2) is limited by the first baffle (8). The other end of the rivet (2) passes through the central hole of the second baffle (3) and is riveted and welded to the side of the second baffle (3) away from the wires (7).

3. A carbon brush for thermal power plants according to claim 2, characterized in that, The first baffle (8) has a C-shaped structure, the second baffle (3) has a ring structure, and solder paste is applied between the copper layers of the second baffle (3), the first baffle (8) and the sink (11).

4. A process for welding copper plating to wires on a thermal power carbon brush body, characterized in that, Includes the following steps: S1: Process the carbon brush body according to the drawings (1); S2: Make an aluminum box (6). The size of the aluminum box (6) is compatible with the carbon brush body (1). Put the carbon brush body (1) into the aluminum box (6) and place it into a vacuum electrosputtering copper plating machine. Plate the sinks (11) on both sides of the brush body with copper. S3: Place the copper-plated product into a self-made bottom arc wire drawing machine to complete the bottom arc wire drawing and form an arc groove (9). S4: Place the bottom of the wire-drawn product on a grinding machine and use a cutting disc to process the bottom air vent (10); S5: After the exhaust groove (10) is processed, apply solder paste evenly to the copper-plated surface of the sink (11) of the carbon brush body (1); S6: Insert rivet (2), pass two wires (7) through the top hole of the carbon brush, and wrap them in circles around the two side grooves (11). Then, apply solder paste evenly to the wires (7) in the groove (11), and then place the bottom first baffle (8). Apply solder paste evenly on the first baffle (8), and then add the top second baffle (3) before placing it into the pre-pressing mold for pre-pressing. S7: After pre-pressing, place the product on the riveting mold and tighten it with high-strength rivets. Then, place the brush body in the high-frequency heating induction zone. S8: Start the high-frequency heating equipment, start the cooling circulation system, start the temperature control system, monitor the heating temperature, and after welding is completed, wait for the temperature to cool down before taking out the product.

5. The process for copper plating of a thermal power carbon brush body and welding of a conductor according to claim 4, characterized in that, In S2, the vacuum range of the vacuum electrosputtering copper plating machine is between 3.5 and 2, the current is 120-150A, the voltage is 380V, the temperature is 1000℃, and the vacuum electrosputtering time is 20 minutes.

6. The process for copper plating of a thermal power carbon brush body and welding of a conductor according to claim 5, characterized in that, The size of the sink (11) is φ16.0mm, and the copper plating thickness is 0.01mm-0.015mm.

7. The process for copper plating of a thermal power carbon brush body and welding of a conductor according to claim 4, characterized in that, The width of the exhaust groove is 0.5 mm.

8. The process for copper plating of a thermal power carbon brush body and welding of a conductor according to claim 4, characterized in that, In S6, the preload is 5 kg.

9. The process for copper plating of a thermal power carbon brush body and welding of a conductor according to claim 4, characterized in that, In S7, the rivet locking and reinforcement force is 3 kg, and the riveting time is 2 seconds.

10. The process for copper plating of a thermal power carbon brush body and welding of a conductor according to claim 4, characterized in that, In step S8, after heating to 225°C, the temperature is held constant for 5 seconds to complete the welding. After the temperature cools down to below 150°C, the product is removed.

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