Processing technology of diamond friction gasket

Abstract

The invention belongs to the technical field of friction plate machining, and particularly relates to a machining technology of a diamond friction gasket. Comprising the following steps of first-time heat treatment, grinding and polishing, hanging rack mounting and oil removal, first-time water washing, acid pickling, second-time water washing, activation, third-time water washing, Ni-P diamond chemical plating, fourth-time water washing, hot water washing, drying, hanging rack dismounting and second-time heat treatment and finished product inspection. According to the method, the Ni-P-diamond composite coating is plated in one step, so that the process steps can be reduced, the processing time can be shortened, the speed is high, and the efficiency is high; by controlling the parameters of the air stirrer and the proportion of the chemical plating solution, the problems of non-uniform diamond proportion, low electroplating efficiency and uncontrollable diamond density are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of friction plate processing, and in particular relates to a processing technology for a diamond friction pad. Background Art

[0002] With the development of lightweight automobiles, the lightweight design of engines requires the removal of redundant parts, the reduction of part overlap, and the reduction of part mass, which makes the internal structure of the engine more compact and the diameter of the camshaft smaller. In order to improve the bearing capacity of the engine bolts during power transmission, this requires sufficient friction on the contact surface of the parts. Plating Ni-P-micron diamond chemical composite coating on the surface of spring steel gaskets can increase the surface friction coefficient, which greatly increases the friction on the contact surface of the parts.

[0003] At present, the traditional processing technology uses electroplating to plate diamond onto the surface of the friction pad, but the electroplating efficiency is low, the diamond ratio is uneven, and the diamond density is uncontrollable. After searching, there are also methods of chemical diamond plating in the prior art, such as the disclosed invention patent with publication number CN106591810B, which discloses a method for preparing a Ni-P coating surface uniformly inlaid with diamond particles, wherein the chemical composite plating in the preparation steps is a three-step plating method: the first step is to plate a Ni-P pre-plating layer with a thickness of 1 to 3 μm on the surface of the spring steel gasket substrate; the second step is to plate a Ni-P-micron diamond composite coating on the pre-plating layer, the coating thickness is 2 to 5 μm, and the diamond particles can be embedded on the coating surface; the third step is to continue Ni-P chemical plating, the coating thickness is 2 to 5 μm, and the diamond embedded on the coating surface in the second step is deeply buried, and in the final coating, 1 / 2 to 2 / 3 of the diamond particle size is embedded in the Ni-P coating, and the rest is exposed outside the coating surface. Another example is the invention patent that has been published, with the publication number CN102758194A, which discloses a production method for diamond chemical composite plated automobile friction pads. The chemical composite plating in the production method adopts a two-step plating method. The first step is to plate a Ni-P layer with a thickness of 5 to 15 μm; the second step is to plate a Ni-P-micron diamond coating layer, the thickness of which is half of the diamond particle size. After plating, the diamond is embedded in the coating layer in a semi-naked state. The chemical composite plating methods in the above two patents are to first plate the Ni-P layer and then plate the Ni-P-micron diamond composite coating. However, this plating method not only has more process steps and takes a long time, but also has higher requirements on equipment.

[0004] Therefore, improvements are urgently needed. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a processing technology for a diamond friction pad, comprising the following steps:

[0006] 1) First heat treatment: keep the friction pad blank at 270°C ± 10°C for 2 hours, and then cool it in the furnace.

[0007] 2) Grinding and polishing: Grinding and polishing the friction pad blank after being processed in step 1).

[0008] 3) Putting on the hanger and degreasing: Hang the friction gasket blank treated in step 2) on the hanger, and then use a degreasing agent with a concentration of 3-5% to degrease the friction gasket blank on the hanger for 3 minutes.

[0009] 4) First water washing: Wash the friction gasket blank after the treatment in step 3).

[0010] 5) Pickling: Pickling the friction pad blank after the treatment in step 4).

[0011] 6) Second water washing: Wash the friction gasket blank after the treatment in step 5).

[0012] 7) Activation: Activate the friction pad blank after the treatment in step 6) with an activation liquid.

[0013] 8) Third water washing: The friction pad blank treated in step 7) is washed with water.

[0014] 9) Ni-P diamond chemical plating: the rack is mounted on a processing device with a stirring tank, a chemical plating solution is prepared in the stirring tank, and the friction gasket blank treated in step 8) is chemically plated to obtain a friction gasket with diamond plated on the surface.

[0015] 10) Fourth water washing: The friction pad prepared in step 9) is washed with water.

[0016] 11) Hot water washing: Use ultrasonic hot water washing at a temperature above 80°C to wash the friction pad treated in step 10) for 45 seconds to clean off the loose diamonds.

[0017] 12) Drying: Dry the friction pad after being treated in step 11).

[0018] 13) Lowering the rack and second heat treatment: Remove the friction pad treated in step 12) from the rack and keep it warm at 150°C ± 10°C for 2 hours.

[0019] 14) Finished product inspection: Use an automatic image dimension measuring instrument and an electron microscope to inspect the appearance and size of the friction gasket after the treatment in step 13), and obtain the finished friction gasket after passing the inspection.

[0020] Optionally, the pickling solution in step 5) is hydrochloric acid with a concentration of 5-8%, and the pickling time is 60±10 seconds.

[0021] Optionally, the activation solution in step 7) is sulfuric acid with a concentration of 3-5%, and the activation treatment time is 60±10 seconds.

[0022] Optionally, the formula of the chemical plating solution in step 9) includes: 12-18 g / L nickel sulfate, 0.01 g / L brightener, 0.01 g / L preservative, 14-20 g / L sodium hypophosphite, 0.05 g / L ammonia water, 0.3 g / L malic acid, 0.05 g / L sulfuric acid and 0.2 g / L diamond; during the plating process, the plating solution temperature is adjusted to 88°C, the pH value is 5, the stirring rate is 150 r / min, the plating time is 26 min, and after the plating is completed, it is allowed to stand, washed, dried, and heat treated to obtain a surface coated with a Ni-PC composite coating.

[0023] Specifically, nickel sulfate provides Ni element for the plating layer and adjusts the composition and properties of the plating solution, such as pH value, conductivity, etc.; brightener can adjust the composition and deposition efficiency of the metal plating layer, so that the surface of the plating layer achieves a bright effect; the preservative is mainly used to enhance the anti-corrosion performance of the friction gasket in order to prevent the chemical plating solution from being contaminated by microorganisms during storage and use; sodium hypophosphite is used as a reducing agent to reduce nickel ions in nickel salts, and it itself decomposes to produce phosphorus atoms that enter the plating layer and exist in the plating layer in the form of Ni3P compounds; ammonia water can make metal ions more stable in the chemical plating solution, which helps to improve the conductivity of the chemical plating solution; malic acid can maintain the stability of the chemical plating solution; sulfuric acid plays a role in adjusting the pH value of the solution; diamond plays a role in enhancing the hardness and wear resistance of the friction gasket.

[0024] Optionally, the processing device in step 9) includes a support frame, a sliding frame and a stirring pool, the support frame is arranged above the stirring pool, the support frame includes a top plate and two vertical plates arranged on the left and right sides below the top plate, two mounting seats are arranged on the left and right ends above the top plate, a transmission rod is rotatably connected between the two mounting seats, and one end of the transmission rod is transmission-connected to a reduction motor, the bottom ends of the two vertical plates are fixed on the stirring pool, the inner sides of the two vertical plates are vertically provided with slide rails, the sliding frame is arranged inside the support frame, the sliding frame includes two horizontal plates and two side plates arranged on the left and right sides of the two horizontal plates, a crossbeam is fixed above the cross plate at the top, and a crossbeam is fixed on the crossbeam A belt is fixed, and the top end of the belt passes through the top plate and is fixedly wound on the transmission rod. A servo motor is arranged between the two horizontal plates. The two side plates correspond to the two vertical plates respectively. The outer sides of the side plates are provided with slide grooves slidably connected to the slide rails. A hanger is rotatably connected between the bottoms of the two side plates. A rotating shaft is fixedly arranged at both ends of the hanger, and the rotating shaft at one end of the hanger is connected to the output shaft of the servo motor through a transmission gear set. An air agitator is arranged in the mixing tank. The air agitator includes an air duct laid at the bottom end of the mixing tank, a plurality of air outlet holes are opened on the air duct, the outside of the air duct is connected to the air storage tank, and the air storage tank is connected to the air compressor through a pipeline.

[0025] Specifically, after adding the chemical plating solution into the stirring tank, air can be introduced into the air guide pipe through an air compressor to stir the chemical plating solution. After the friction pad is hung on the hanger, the transmission rod is driven to rotate by controlling the reduction motor to unwind the belt, so that the sliding frame moves downward along the slide rail under the action of the belt. After the entire hanger is moved into the stirring tank, the reduction motor is turned off; at the same time, the servo motor is controlled to drive the hanger to rotate circumferentially so that the diamond is evenly plated on the friction pad.

[0026] Optionally, an electric control box is provided on the top plate, and the reduction motor and the servo motor are both electrically connected to the electric control box.

[0027] Specifically, convenient control.

[0028] Optionally, two limiters are provided at the upper and lower ends of the inner side of the vertical plate.

[0029] Specifically, the two limiters are used to limit the up and down movement of the sliding frame, thereby limiting the lifting limit of the hanging frame.

[0030] Optionally, the drying temperature in step 12) is ≥80°C, and the drying time is 3 minutes.

[0031] Optionally, in step 13), the diamond ratio on the surface of the friction pad needs to be detected before heat treatment.

[0032] The beneficial effects of the present invention are:

[0033] (1) The problem of low electroplating efficiency is solved. The Ni-P-diamond composite coating of the present invention can be plated in one step, with high speed and efficiency, and the diamond does not need to be cleaned with ethanol solution and ultrasonic wave, thus reducing the pre-treatment process, reducing the process flow and shortening the processing time.

[0034] (2) Solved the problem of uneven diamond ratio and uncontrollable diamond density. The present invention controls the operating parameters of the electric control box and the ratio of the chemical plating solution to make the chemical plating solution more evenly mixed; controls the proportion of diamonds on the friction pad by controlling the time of chemical plating, so that the density can be controlled; controls the circumferential movement of the hanger to ensure that the diamonds on both sides of the friction pad are uniform; in addition, the stirrer in the stirring tank adopts a specific speed and intermittent stirring. When the stirring rate decreases, the diamond ratio increases, for example: when the stirring rate is 150r / min, the diamond ratio is 30%; when the stirring rate is 100r / min, the diamond ratio is 25%; it can also solve the problem that the diamond particles are large and cannot be plated.

[0035] (3) The bottom of the stirring tank adopts an arc-shaped structure, which can make the chemical plating solution stirred more evenly and react more fully. The arc-shaped stirring tank can reduce eddy currents and dead corners, and reduce the risk of damage to the tank body; it is easy to clean and improves the quality of the plating solution.

[0036] (4) The chemical degreasing method is simple in process, easy to operate, and the degreasing agent is non-toxic and non-flammable.

[0037] (5) During chemical plating, the friction gasket is placed horizontally. Compared with vertical placement, the stirring effect of air stirring makes the chemical plating solution uniform, so that the coating thickness on both sides of the friction gasket is uniform, solving the problem of uneven chemical plating solution.

[0038] (6) The processing device in the present invention has a simple structure and low maintenance cost. It can process friction pads of various specifications at the same time, has a wide range of applications and high practicality. It is easy to assemble, has a fast plating speed and good stability, and greatly shortens the processing cycle. In addition, it can also be used for chemical plating operations of 10-55 micron diamonds, and the diamond content of the plated friction pads is 8%-50%. By using air stirring, the diamonds at the bottom of the stirring tank can be blown up to make the plating solution more evenly integrated. For large-particle diamonds (above 35 microns), intermittent stirring and air stirring are used to solve the problem that large-particle diamonds cannot be plated due to their own weight, excessive inertia, etc., and accumulate at the bottom. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0040] Figure 1 It is a schematic diagram of the structure of the processing device in an embodiment of the present invention.

[0041] Figure 2 for Figure 1 Schematic diagram of the structure after removing the stirring tank.

[0042] Figure 3 Schematic diagram of the structure of the sliding frame in the embodiment of the present invention.

[0043] Figure 4 This is a surface morphology diagram of the diamond friction pad after plating in an embodiment of the present invention.

[0044] In the figure: 1. support frame, 2. sliding frame, 3. mixing tank, 4. top plate, 5. vertical plate, 6. mounting seat, 7. transmission rod, 8. reduction motor, 9. slide rail, 10. cross plate, 11. side plate, 12. cross beam, 13. belt, 14. servo motor, 15. slide groove, 17. rotating shaft, 18. transmission gear set, 19. air guide pipe, 20. electric control box, 21. limiter. DETAILED DESCRIPTION

[0045] The present invention is described clearly below in conjunction with the drawings and specific embodiments in the embodiments of the present invention. The description herein is only used to explain the present invention, but is not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0046] Example

[0047] like Figure 1-3 As shown, an embodiment of the present invention provides a processing technology for a diamond friction pad, comprising the following steps:

[0048] 1) First heat treatment: keep the friction pad blank at 270°C ± 10°C for 2 hours, and then cool it in the furnace.

[0049] 2) Grinding and polishing: Grinding and polishing the friction pad blank after being processed in step 1).

[0050] 3) Putting on the hanger and degreasing: Hang the friction gasket blank treated in step 2) on the hanger, and then use a degreasing agent with a concentration of 3-5% to degrease the friction gasket blank on the hanger for 3 minutes.

[0051] 4) First water washing: Wash the friction gasket blank after the treatment in step 3).

[0052] 5) Pickling: Pickle the friction gasket blank treated in step 4) with 8% hydrochloric acid for 60±10 seconds.

[0053] 6) Second water washing: Wash the friction gasket blank after the treatment in step 5).

[0054] 7) Activation: The friction pad blank treated in step 6) is activated with 5% sulfuric acid for 60±10 seconds.

[0055] 8) Third water washing: The friction pad blank treated in step 7) is washed with water.

[0056] 9) Ni-P diamond chemical plating: installing the rack on a processing device with a stirring tank, preparing a chemical plating solution in the stirring tank, and chemically plating the friction gasket blank after the treatment in step 8) to obtain a friction gasket with diamond plated on the surface;

[0057] The formula of the chemical plating solution includes: 15g / L nickel sulfate, 0.01g / L brightener, 0.01g / L preservative, 17g / L sodium hypophosphite, 0.05g / L ammonia water, 0.3g / L malic acid, 0.05g / L sulfuric acid and 0.2g / L diamond; during the plating process, the plating solution temperature is adjusted to 88°C, the pH value is 5, the stirring rate is 150r / min, the plating time is 26min, and after the plating is completed, it is allowed to stand, washed, dried, and heat treated to obtain a surface coated with a Ni-PC composite coating.

[0058] It is understandable that nickel sulfate provides Ni element for the plating layer and adjusts the composition and properties of the plating solution, such as pH value, conductivity, etc.; brightener can adjust the composition and deposition efficiency of the metal plating layer, so that the surface of the plating layer can achieve a bright effect; the preservative is mainly to enhance the anti-corrosion performance of the friction gasket, in order to prevent the chemical plating solution from being contaminated by microorganisms during storage and use; sodium hypophosphite is used as a reducing agent to reduce the nickel ions in the nickel salt, and it itself decomposes to produce phosphorus atoms that enter the plating layer and exist in the plating layer in the form of Ni3P compounds; ammonia water can make metal ions more stable in the chemical plating solution, which helps to improve the conductivity of the chemical plating solution; malic acid can maintain the stability of the chemical plating solution; sulfuric acid plays a role in adjusting the pH value of the solution; diamond plays a role in enhancing the hardness and wear resistance of the friction gasket.

[0059] In addition, the processing device includes a support frame 1, a sliding frame 2 and a stirring pool 3. The support frame 1 is arranged above the stirring pool 3. The support frame 1 includes a top plate 4 and two vertical plates 5 arranged on the left and right sides below the top plate 4. Two mounting seats 6 are arranged on the left and right ends above the top plate 4. A transmission rod 7 is rotatably connected between the two mounting seats 6, and one end of the transmission rod 7 is transmission-connected to a reduction motor 8. The bottom ends of the two vertical plates 5 are fixed on the stirring pool 3. The inner sides of the two vertical plates 5 are vertically provided with slide rails 9. The sliding frame 2 is arranged inside the support frame 1. The sliding frame 2 includes two horizontal plates 10 and two side plates 11 arranged on the left and right sides of the two horizontal plates 10. A crossbeam 12 is fixed above the top horizontal plate 10, and a belt 13 is fixed on the crossbeam 12. The top end of the belt 13 passes through the top plate 4 and is fixedly wound around the transmission rod 7. A servo motor 14 is arranged between the two horizontal plates 10. The two side panels 11 correspond to the two vertical panels 5 respectively, and the outer side of the side panels 11 is provided with a slide groove 15 slidably connected to the slide rail 9, and a hanger is rotatably connected between the bottoms of the two side panels 11, and a rotating shaft 17 is fixedly provided at both ends of the hanger, and the rotating shaft 17 at one end of the hanger is connected to the output shaft of the servo motor 14 through a transmission gear set 18. The mixing tank 3 is provided with an air agitator, and the air agitator includes an air duct 19 laid at the bottom end of the mixing tank 3, and a plurality of air outlet holes are opened on the air duct 19, and the outside of the air duct 19 is connected to the air compressor; in addition, an electric control box 20 is also provided on the top plate 4, and the reduction motor 8, the servo motor 14 and the air compressor are all electrically connected to the electric control box 20 for easy control; two limiters 21 are provided at the upper and lower ends of the inner side of the vertical panel 5, and the two limiters 21 are used to provide a limit for the up and down movement of the sliding frame 2, thereby limiting the lifting limit of the hanger.

[0060] It is understandable that after adding the chemical plating solution into the stirring tank 3, air can be introduced into the air guide pipe 19 through the air compressor to stir the chemical plating solution. After the friction pad is hung on the bracket, the transmission rod 7 is driven to rotate by controlling the reduction motor 8 to unwind the belt 13, so that the sliding frame 2 moves downward along the slide rail under the action of the belt 13. After the entire bracket is moved into the stirring tank 3, the reduction motor 8 is turned off; at the same time, the servo motor 14 is controlled to drive the bracket to rotate circumferentially so that the diamond is evenly plated on the friction pad.

[0061] 10) Fourth water washing: The friction pad prepared in step 9) is washed with water.

[0062] 11) Hot water washing: Use ultrasonic hot water washing at a temperature above 80°C to wash the friction pad treated in step 10) for 45 seconds to clean off the loose diamonds.

[0063] 12) Drying: Dry the friction pad after the treatment in step 11) at a drying temperature not lower than 80° C. for 3 minutes.

[0064] 13) Lowering the rack and second heat treatment: Remove the friction pad treated in step 12) from the rack, detect the diamond ratio on the surface of the friction pad, and then keep it warm at 150°C ± 10°C for 2 hours.

[0065] 14) Finished product inspection: Use an automatic image dimension measuring instrument and an electron microscope to inspect the appearance and size of the friction gasket after the treatment in step 13), and obtain the finished friction gasket after passing the inspection.

[0066] like Figure 4 As shown, the surface morphology of the diamond friction pad produced by this processing technology is shown under a microscope. It can be seen that the diamond particles plated on the surface of the friction pad are very uniform, indicating that this process has great advantages in diamond plating on friction pads.

[0067] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A processing technology for a diamond friction pad, characterized in that: The following steps are involved: 1) First heat treatment: keep the friction pad blank at 270℃±10℃ for 2 hours, and then cool it in the furnace; 2) Grinding and polishing: Grinding and polishing the friction pad blank after being processed in step 1); 3) Putting on the hanger and degreasing: Hang the friction gasket blank treated in step 2) on the hanger, and degreasing the friction gasket blank on the hanger with a degreasing agent with a concentration of 3-5%, which takes 3 minutes; 4) First water washing: washing the friction gasket blank after being treated in step 3); 5) Pickling: Pickling the friction gasket blank after the treatment in step 4); 6) Second water washing: washing the friction gasket blank after being treated in step 5); 7) Activation: Activating the friction pad blank after the treatment in step 6) with an activation liquid; 8) Third water washing: washing the friction gasket blank after being treated in step 7); 9) Ni-P diamond chemical plating: installing the rack on a processing device with a stirring tank, preparing a chemical plating solution in the stirring tank, and chemically plating the friction gasket blank after the treatment in step 8) to obtain a friction gasket with diamond plated on the surface; 10) Fourth water washing: washing the friction pad obtained in step 9); 11) Hot water washing: Use hot water above 80°C to wash the friction pad treated in step 10) for 45 seconds; 12) Drying: Drying the friction pad after being treated in step 11); 13) Lowering the rack and second heat treatment: Remove the friction pad treated in step 12) from the rack and keep it at a temperature of 150°C ± 10°C for 2 hours; 14) Finished product inspection: The appearance and size of the friction gasket after the treatment in step 13) are inspected, and the finished friction gasket is obtained after passing the inspection.

2. The processing technology according to claim 1, characterized in that: The pickling solution in step 5) is hydrochloric acid with a concentration of 5-8%, and the pickling time is 60±10 seconds.

3. The processing technology according to claim 2, characterized in that: The activation solution in step 7) is sulfuric acid with a concentration of 3-5%, and the activation treatment time is 60±10 seconds.

4. The processing technology according to claim 3, characterized in that: The formula of the chemical plating solution in step 9) includes: 12-18g / L nickel sulfate, 0.01g / L brightener, 0.01g / L preservative, 14-20g / L sodium hypophosphite, 0.05g / L ammonia water, 0.3g / L malic acid, 0.05g / L sulfuric acid and 0.2g / L diamond; during the plating process, the plating solution temperature is adjusted to 88°C, the pH value is 5, the stirring rate is 150r / min, the plating time is 26min, and after the plating is completed, it is allowed to stand, washed, dried, and heat treated to obtain a surface coated with a Ni-PC composite coating.

5. The processing technology according to claim 4, characterized in that: The processing device in step 9) includes a support frame, a sliding frame and a stirring pool, the support frame is arranged above the stirring pool, the support frame includes a top plate and two vertical plates arranged on the left and right sides below the top plate, two mounting seats are arranged on the left and right ends above the top plate, a transmission rod is rotatably connected between the two mounting seats, and one end of the transmission rod is transmission-connected to a reduction motor, the bottom ends of the two vertical plates are fixed on the stirring pool, the inner sides of the two vertical plates are vertically provided with slide rails, the sliding frame is arranged inside the support frame, the sliding frame includes two horizontal plates and two side plates arranged on the left and right sides of the two horizontal plates, a crossbeam is fixed above the top horizontal plate, and a A belt, and the top end of the belt passes through the top plate and is fixedly wound on the transmission rod, a servo motor is arranged between the two horizontal plates, the two side plates respectively correspond to the two vertical plates, the outer sides of the side plates are provided with slide grooves slidably connected to the slide rails, a hanger is rotatably connected between the bottoms of the two side plates, both ends of the hanger are fixedly provided with rotating shafts, and the rotating shaft at one end of the hanger is connected to the output shaft of the servo motor through a transmission gear set, the mixing tank is provided with an air agitator, the air agitator comprises an air duct laid at the bottom end of the mixing tank, a plurality of air outlets are opened on the air duct, the outside of the air duct is connected to the air storage tank, and the air storage tank is connected to the air compressor through a pipeline.

6. The processing technology according to claim 5, characterized in that: An electric control box is arranged on the top plate, and the reduction motor and the servo motor are electrically connected to the electric control box.

7. The processing technology according to claim 6, characterized in that: Two limiters are arranged at the upper and lower ends of the inner side of the vertical plate.

8. The processing technology according to claim 7, characterized in that: The drying temperature in step 12) is ≥80°C and the drying time is 3 minutes.

9. The processing technology according to claim 8, characterized in that: In step 13), the diamond ratio on the surface of the friction pad needs to be tested before heat treatment.

Images