A method and apparatus for applying a self-lubricating release agent to powder metallurgy compacts

Abstract

The application discloses a powder metallurgy pressing release agent self-lubricating coating method and device, the method comprises the following steps: S1, the prepared release agent is put into the container, and the release agent is poured into the cavity of the mold under the stirring state; S2, by controlling the up and down reciprocating motion of the upper punch in the cavity, the release agent is uniformly coated on the inner wall of the cavity and the outer wall of the upper punch; S3, after the step S2 is finished, the upper punch is moved upward again to be flat with the upper plane of the mold, and the brush head is used to wipe off the release agent remaining on the top surface of the upper punch; the device comprises a press shell, a container, an upper punch and a mold for realizing the above method; the method utilizes the reciprocating motion of the upper punch to realize the self-lubrication of the mold cavity and the outer wall of the upper punch, so that the release agent reaches the uniform self-lubricating "wall-hanging" state; and the brush head is used to clean the excess release agent, so that the release agent is prevented from being brought into the mold to cause product quality problems such as cracking and inclusion.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy technology, specifically to a method and apparatus for applying a self-lubricating release agent for powder metallurgy pressing. Background Technology

[0002] On powder metallurgy pressing production lines, to ensure smooth demolding of the pressed molds, a release agent is typically applied to all parts of the mold that come into contact with the powder. Current technology primarily involves using a tool similar to the mold to apply the release agent. However, this process suffers from the inability to control the amount of release agent applied. Excess release agent flows to the bottom of the mold under gravity, significantly increasing the risk of release agent contamination and causing quality problems such as cracking and inclusions in the product.

[0003] Since mold release agents are generally formulated suspensions, they can easily cause nozzle clogging in fine nozzles, leading to uneven coating. Furthermore, the mold release agent sprayed through the nozzle will still settle under gravity and cannot form a uniform "wall" on the mold surface.

[0004] The present invention aims to solve the problems of uneven application of release agent on the inner wall of the mold and excess release agent residue during the powder metallurgy pressing process. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a method for applying a self-lubricating release agent for powder metallurgy pressing.

[0006] The technical solution of this invention is: a self-lubricating coating method for a release agent used in powder metallurgy pressing, comprising the following steps:

[0007] S1. Place the prepared release agent into a container and pour it into the cavity of the mold while stirring.

[0008] The liquid level of the release agent in the cavity is maintained at 5-10 mm, and the injection time of the release agent is 10-20 seconds.

[0009] S2. By controlling the upper punch inside the press housing to move up and down reciprocally 5 to 10 times in the cavity, the release agent is evenly coated on the inner wall of the cavity and the outer wall of the upper punch.

[0010] The required tablet thickness is 2 times ≤ the upward movement height of the upper punch ≤ the upper plane of the mold, and the time for the upper punch to perform one up-and-down reciprocating motion is 2 seconds.

[0011] S3. After step S2 is completed, move the upper punch upward again until it is level with the upper plane of the mold, and then wipe away the residual release agent on the top surface of the upper punch with a brush.

[0012] Furthermore, the release agent is an alcohol:zinc stearate mixture with a mass ratio of 9:1, wherein the volume fraction of the alcohol is 75%.

[0013] Note: Zinc stearate has good lubricity and a good release effect. Alcohol has a certain dissolving ability for release agents.

[0014] A self-lubricating coating device for a release agent used in powder metallurgy pressing is used to realize the above-mentioned self-lubricating coating method for a release agent used in powder metallurgy pressing. The device includes a press housing, a container, an upper punch, and a mold. The mold and the upper punch are arranged sequentially from top to bottom inside the press housing. The mold is fixedly connected to the inner wall of the press housing and has a cavity. The upper punch is slidably connected to the inner wall of the cavity and is connected to a first motion mechanism arranged at the bottom of the press housing.

[0015] The first motion mechanism includes a lifting motor disposed at the bottom of the press housing and fixedly connected to the upper punch, a drive rod for unidirectional lateral movement when the upper punch moves up and down, and a brush head connected to the drive rod via a transmission assembly.

[0016] The container has a feed inlet at the top and a discharge outlet at the bottom, and a stirring mechanism inside the container; the press housing has a second motion mechanism for controlling the transfer of the container and an opening and closing mechanism for opening the discharge outlet.

[0017] The second motion mechanism includes a collar and a first electric telescopic rod with one end fixedly connected to the collar. The other end of the first electric telescopic rod is fixedly connected to the inner wall of the press housing. A lever switch for rotating control of the extension and retraction of the first electric telescopic rod is provided on the inner wall of the collar. The lever switch is rotatably connected to the inner wall of the collar and electrically connected to the first electric telescopic rod.

[0018] The upper punch is provided with a trapezoidal through hole, the drive rod passes through the trapezoidal through hole, and the drive rod is provided with a plurality of locking blocks that engage with the trapezoidal through hole at intervals. The other end of the drive rod is slidably connected to a sliding groove provided on the inner wall of the press housing.

[0019] Explanation: By providing the above-mentioned coating equipment, the automation effect of coating is improved and the labor consumption is reduced; the movement of the container is automatically controlled by setting the first electric telescopic rod; the injection of the release agent is controlled by the opening and closing mechanism, and the volume of the release agent is controlled by the liquid level sensor; and the position of the brush head can be controlled by the movement of the upper punch and the drive rod, thereby controlling the brush head to wipe the residual release agent on the top surface of the upper punch.

[0020] Furthermore, the stirring mechanism includes a rotary motor mounted on the top of the container, a stirring rod fixedly connected to the output shaft of the rotary motor, and spiral blades mounted on the stirring rod, the stirring rod being located inside the container.

[0021] Note: By installing the above-mentioned stirring mechanism inside the container, it is possible to ensure that the release agent is stirred when there is release agent inside the container, thereby preventing the release agent from settling.

[0022] Furthermore, the discharge port is provided with a cover plate that is hinged to the side wall of the discharge port by a torsion spring and seals the discharge port, and the cover plate is provided with a magnetic sheet; the opening and closing mechanism includes a second electric telescopic rod for opening the discharge port when the container reaches the top of the cavity, and the second electric telescopic rod is provided with a magnetic rod with the same magnetism as the magnetic sheet;

[0023] The inner wall of the cavity is equipped with a liquid level sensor and a first controller for controlling the retraction of the second electric telescopic rod and controlling the opening and closing of the lifting motor. The liquid level sensor and the second electric telescopic rod are both electrically connected to the first controller.

[0024] The first electric telescopic pole is equipped with a second controller for controlling the extension of the second electric telescopic pole, and both the first and second electric telescopic poles are electrically connected to the second controller.

[0025] Explanation: By setting a second electric telescopic rod, the magnetic rod can be extended synchronously when the container moves above the cavity to control the opening of the container. When the amount of release agent poured in reaches the standard, the container can be closed by retracting through the liquid level sensor, thus improving the automation effect.

[0026] Furthermore, the transmission assembly includes a first airbag fixedly connected to one end of the drive rod, an air transmission pipe with one end penetrating through the mold, and a second airbag fixedly connected to the brush head. The other end of the air transmission pipe is fixedly connected to the bottom of the press housing, and the bottom of the air transmission pipe is connected to the first airbag, while the top of the air transmission pipe is connected to the second airbag.

[0027] Explanation: The movement of the brush head is controlled by pneumatic force through the setting of a first airbag and a second airbag, resulting in a simple structure.

[0028] Furthermore, both the first airbag and the second airbag are fitted with springs to enhance the restoring elasticity of the first airbag and the second airbag.

[0029] Explanation: By incorporating springs, the restoring elasticity of the first and second airbags is enhanced, thereby improving the aerodynamic effect.

[0030] Furthermore, the mold is provided with an elastic block for providing reciprocating elastic force to the brush head after the brush head brushes over the upper punch.

[0031] Note: By setting up an elastic block, the brush head can repeatedly wipe the upper punch multiple times after wiping it once, thus improving the wiping effect on the residual release agent on the upper punch.

[0032] Furthermore, the container, spiral blades, and stirring rod are all made of stainless steel.

[0033] Note: Using stainless steel can prevent the material from reacting with the release agent and thus compromising the release effect.

[0034] The beneficial effects of this invention are:

[0035] (1) The coating method of the present invention can ensure that the release agent in the container remains uniform and without sedimentation for a long time by continuously stirring the release agent.

[0036] (2) The coating method of the present invention utilizes the reciprocating motion of the upper punch to achieve self-lubrication of the mold cavity and the outer wall of the upper punch, so that the release agent reaches a uniform self-lubricating "wall-hanging" state.

[0037] (3) The coating method of the present invention uses a brush head to clean up excess release agent, so as to avoid the release agent being brought into the mold and causing product quality problems such as cracking and inclusion. Attached Figure Description

[0038] Figure 1 This is an overall structural diagram of the coating equipment used in the coating method of the present invention;

[0039] Figure 2 This is a diagram showing the configuration of the first electric telescopic rod of the coating equipment used in the coating method of the present invention;

[0040] Figure 3 This is a structural diagram of the container of the coating equipment used in the coating method of the present invention;

[0041] Figure 4 This is a diagram of the collar structure of the coating equipment used in the coating method of the present invention;

[0042] Figure 5 This is a view of the tablet surface obtained by the coating method of the present invention;

[0043] Figure 6 This is a picture of the tablet surface after the mold cavity has been manually coated with release agent;

[0044] Among them, 1-pressor housing, 2-container, 21-feed inlet, 22-discharge outlet, 221-cover plate, 222-torsion spring, 223-magnetic sheet, 23-rotary motor, 231-stirring rod, 232-spiral blade, 3-mold, 31-cavity, 32-liquid level sensor, 4-upper punch, 41-lifting motor, 42-drive rod, 421-block, 43-trapezoidal through hole, 5-brush head, 51-second airbag, 52-first airbag, 521-spring, 53-air transmission pipe, 6-second electric telescopic rod, 61-magnetic rod, 62-elastic block, 7-collar, 71-first electric telescopic rod, 72-toggle switch. Detailed Implementation

[0045] The present invention will now be described in more detail with reference to specific embodiments, so as to better demonstrate the advantages of the present invention.

[0046] Example 1

[0047] A self-lubricating coating device for release agent in powder metallurgy pressing, such as Figure 1 As shown, the press includes a press housing 1, a container 2, an upper punch 4, and a mold 3. The mold 3 and the upper punch 4 are arranged sequentially from top to bottom inside the press housing 1. The mold 3 is fixedly connected to the inner wall of the press housing 1, and the mold 3 is provided with a cavity 31. The upper punch 4 is slidably connected to the inner wall of the cavity 31, and the upper punch 4 is connected to a first motion mechanism provided at the bottom of the press housing 1.

[0048] like Figure 1 As shown, the first motion mechanism includes a lifting motor 41 disposed at the bottom of the press housing 1 and fixedly connected to the upper punch 4, a drive rod 42 for unidirectional lateral movement when the upper punch 4 moves up and down, and a brush head 5 connected to the drive rod 42 via a transmission assembly.

[0049] like Figure 1 and Figure 3 As shown, the container 2 is provided with a feed inlet 21 at the top and a discharge outlet 22 at the bottom, and a stirring mechanism is provided inside the container 2; the press housing 1 is provided with a second motion mechanism for controlling the transfer of the container 2 and an opening and closing mechanism for opening the discharge outlet 22.

[0050] like Figure 3 As shown, the stirring mechanism includes a rotary motor 23 mounted on the top of the container 2, a stirring rod 231 fixedly connected to the output shaft of the rotary motor 23, and a spiral blade 232 mounted on the stirring rod 231. The stirring rod 231 is located inside the container 2. The container 2, the spiral blade 232, and the stirring rod 231 are all made of stainless steel. The rotary motor 23 is a commercially available rotary motor.

[0051] like Figure 1 and Figure 3 As shown, the discharge port 22 is provided with a cover plate 221 that is hinged to the side wall of the discharge port 22 by a torsion spring 222 and seals the discharge port 22, and a magnetic sheet 223 is provided on the cover plate 221; the opening and closing mechanism includes a second electric telescopic rod 6 for opening the discharge port 22 when the container 2 reaches above the cavity 31, and the second electric telescopic rod 6 is provided with a magnetic rod 61 with the same magnetism as the magnetic sheet 223;

[0052] like Figure 1 As shown, the inner wall of the cavity 31 is provided with a liquid level sensor 32 and a first controller for controlling the retraction of the second electric telescopic rod 6 and controlling the opening and closing of the lifting motor 41. The liquid level sensor 32 and the second electric telescopic rod 6 are both electrically connected to the first controller.

[0053] like Figure 1 , Figure 2 and Figure 4 As shown, the second motion mechanism includes a collar 7 and a first electric telescopic rod 71 with one end fixedly connected to the collar 7. The other end of the first electric telescopic rod 71 is fixedly connected to the inner wall of the press housing 1. A lever switch 72 for rotating control of the extension and retraction of the first electric telescopic rod 71 is provided on the inner wall of the collar 7. The lever switch 72 is rotatably connected to the inner wall of the collar 7 and electrically connected to the first electric telescopic rod 71.

[0054] like Figure 1 and Figure 3 As shown, the first electric telescopic rod 71 is provided with a second controller for controlling the extension of the second electric telescopic rod 6, and both the first electric telescopic rod 71 and the second electric telescopic rod 6 are electrically connected to the second controller.

[0055] like Figure 1 and Figure 2 As shown, the upper punch 4 is provided with a trapezoidal through hole 43, the drive rod 42 passes through the trapezoidal through hole 43, and the drive rod 42 is provided with a plurality of locking blocks 421 that engage with the trapezoidal through hole 43 at intervals. The other end of the drive rod 42 is slidably connected to a sliding groove provided on the inner wall of the press housing 1.

[0056] like Figure 1 As shown, the transmission assembly includes a first airbag 52 fixedly connected to one end of the drive rod 42, an air transmission pipe 53 with one end penetrating through the mold 3, and a second airbag 51 fixedly connected to the brush head 5. The other end of the air transmission pipe 53 is fixedly connected to the bottom of the press housing 1, and the bottom of the air transmission pipe 53 is connected to the first airbag 52, and the top of the air transmission pipe 53 is connected to the second airbag 51.

[0057] like Figure 1As shown, springs 521 are fitted on both the first airbag 52 and the second airbag 51 to enhance the restoring elasticity of the first airbag 52 and the second airbag 51.

[0058] like Figure 1 As shown, the mold 3 is provided with an elastic block 62 for providing reciprocating elastic force to the brush head 5 after the brush head 5 brushes over the upper punch 4;

[0059] The lifting motor 41, liquid level sensor 32, first electric telescopic rod 71, second electric telescopic rod 6, first controller and second controller are all commercially available devices.

[0060] The method for coating using the above-mentioned coating equipment includes the following steps:

[0061] S1. The prepared release agent is placed into container 2 through inlet 21. At the same time, the rotary motor 23 is turned on to make the stirring rod 231 drive the spiral blade 232 to stir the release agent. Then, container 2 is placed into collar 7 and locked downwards. During the downward movement, the lever switch 72 is opened, so that the first electric telescopic rod 7 moves container 2 closer to cavity 31. At the same time, the first electric telescopic rod 71 controls the second electric telescopic rod 6 to extend through the second controller. The release agent is an alcohol:zinc stearate mixture with a mass ratio of 9:1, and the volume fraction of the alcohol is 75%.

[0062] When container 2 reaches above cavity 31, it stops. At this time, the magnetic sheet 223 on cover plate 221 is attracted by magnetic rod 61 and overcomes the elastic force of torsion spring 222 to open outlet 22. The release agent is poured into cavity 31 in 15 seconds under stirring. When liquid level sensor 32 senses that the liquid level of release agent is 8mm, the first controller controls the second electric telescopic rod 6 to drive magnetic rod 61 to retract and move away from container 2. Thus, cover plate 221 seals outlet 22 under the restoring elastic force of torsion spring 222 to stop pouring. Then, container 2 is manually removed from collar 7, so that the first electric telescopic rod 71 returns to its original position.

[0063] S2. At the same time, the liquid level sensor 32 controls the lifting motor 41 to start through the first controller, so that the upper punch 4 moves up and down 8 times in the cavity 31. The required pressing thickness is 4mm, the upper punch 4 moves up 9mm, and the time for the upper punch 4 to move up and down once is 2s.

[0064] During this process, the trapezoidal through hole 43 on the upper punch 4 moves up and down in sync, causing the drive rod 42 to gradually move to the left under the action of the first airbag 52 and the spring 521, thereby transmitting gas through the air transmission tube 53 into the second airbag 51, causing the brush head 5 to gradually approach the cavity 31 under the action of the second airbag 51 and the spring 521.

[0065] S3. After step S2 is completed, the upper punch 4 moves upward again until it is level with the upper plane of the mold 3. At this time, the upper punch 4 remains level, and the drive rod 42 moves to the equilibrium state of the first air bag 52 and the spring 521. The brush head 5 then passes through the upper punch 4 under the action of the second air bag 51 and the spring 521 to wipe away the release agent remaining on the top surface of the upper punch 4.

[0066] Furthermore, when the brush head 5 passes the upper punch 4 and hits the elastic block 62, it bounces back under the action of the elastic block 62 and passes the upper punch 4, thus repeatedly wiping the upper punch 4 and removing the residual release agent on the top surface of the upper punch 4.

[0067] Example 2

[0068] The difference between this embodiment and embodiment 1 is that the liquid level of the release agent in the cavity 31 is maintained at 5 mm, and the injection time of the release agent is 10 s.

[0069] Example 3

[0070] The difference between this embodiment and Embodiment 1 is that the liquid level of the release agent in the cavity 31 is maintained at 10mm, and the injection time of the release agent is 20s.

[0071] Example 4

[0072] The difference between this embodiment and embodiment 1 is that the upper punch 4 moves up and down 5 times in the cavity 31, the required pressing thickness is 4mm, and the upward movement height of the upper punch 4 is 8mm.

[0073] Example 5

[0074] The difference between this embodiment and embodiment 1 is that the upper punch 4 moves up and down 10 times in the cavity 31, the required pressing thickness is 4mm, and the upward movement height of the upper punch 4 is level with the upper plane of the mold 3.

[0075] Experimental Example

[0076] from Figures 5-6 It can be seen that, Figure 6 The pipe fitting is obtained by coating and pressing using the coating method of Example 1. Figure 6 Is with Figure 5 Pressed under the same press, but Figure 6 The coating method involves manually applying a release agent to the mold using a small-sized cylinder, followed by pressing to obtain the pipe fitting. It can be seen that... Figure 6 The pipe fittings have defects such as mold release agent inclusions on their surface, while Figure 5 The surface is smooth and free of mold release agent inclusions.

Claims

1. A method for applying a self-lubricating release agent to powder metallurgy pressing, characterized in that, The method employs a device for self-lubricating coating of release agent for powder metallurgy pressing. The device includes a press housing (1), a container (2), an upper punch (4), and a mold (3). The mold (3) and the upper punch (4) are arranged sequentially from top to bottom inside the press housing (1). The mold (3) is fixedly connected to the inner wall of the press housing (1), and the mold (3) is provided with a cavity (31). The upper punch (4) is slidably connected to the inner wall of the cavity (31), and the upper punch (4) is connected to a first motion mechanism located at the bottom of the press housing (1). The first motion mechanism includes a lifting motor (41) disposed at the bottom of the press housing (1) and fixedly connected to the upper punch (4), a drive rod (42) for unidirectional lateral movement when the upper punch (4) moves up and down, and a brush head (5) connected to the drive rod (42) through a transmission assembly; the transmission assembly includes a first air bladder (52) fixedly connected to one end of the drive rod (42), an air transmission pipe (53) penetrating through the mold (3) at one end, and a second air bladder (51) fixedly connected to the brush head (5). The other end of the air transmission pipe (53) is fixedly connected to the bottom of the press housing (1), and the bottom of the air transmission pipe (53) is connected to the first air bladder (52), and the top of the air transmission pipe (53) is connected to the second air bladder (51); The container (2) has a feed inlet (21) at the top and a discharge outlet (22) at the bottom, and a stirring mechanism is provided inside the container (2); the press housing (1) is provided with a second motion mechanism for controlling the transfer of the container (2) and an opening and closing mechanism for opening the discharge outlet (22); The second motion mechanism includes a collar (7) and a first electric telescopic rod (71) with one end fixedly connected to the collar (7). The other end of the first electric telescopic rod (71) is fixedly connected to the inner wall of the press housing (1). A lever switch (72) for rotating control of the extension and retraction of the first electric telescopic rod (71) is provided on the inner wall of the collar (7). The lever switch (72) is rotatably connected to the inner wall of the collar (7) and electrically connected to the first electric telescopic rod (71). The upper punch (4) is provided with a trapezoidal through hole (43), the drive rod (42) passes through the trapezoidal through hole (43), and the drive rod (42) is provided with a plurality of locking blocks (421) that engage with the trapezoidal through hole (43) at intervals. The other end of the drive rod (42) is slidably connected to a sliding groove provided on the inner wall of the press housing (1). The self-lubricating coating method for the release agent used in powder metallurgy pressing includes the following steps: S1. Place the prepared release agent into the container (2) and pour the release agent into the cavity (31) of the mold (3) while stirring. The liquid level of the release agent in the cavity (31) is maintained at 5~10mm, and the injection time of the release agent is 10~20s; S2. By controlling the upper punch (4) in the press housing (1) to move up and down in the cavity (31) 5 to 10 times, the release agent is evenly coated on the inner wall of the cavity (31) and the outer wall of the upper punch (4). The required thickness of the tablet is twice the height of the upper punch (4) and the upper plane of the mold (3). The time for the upper punch (4) to make one up-and-down reciprocating motion is 2 seconds. S3. After step S2 is completed, move the upper punch (4) upward again until it is level with the upper surface of the mold (3), and then wipe away the residual release agent on the top surface of the upper punch (4) with the brush head (5).

2. The method for applying a self-lubricating release agent for powder metallurgy pressing according to claim 1, characterized in that, The release agent is an alcohol-zinc stearate mixture with a mass ratio of 9:1, and the alcohol has a volume fraction of 75%.

3. The method for applying a self-lubricating release agent for powder metallurgy pressing according to claim 1, characterized in that, The stirring mechanism includes a rotary motor (23) mounted on the top of the container (2), a stirring rod (231) fixedly connected to the output shaft of the rotary motor (23), and a spiral blade (232) mounted on the stirring rod (231). The stirring rod (231) is located inside the container (2).

4. The method for applying a self-lubricating release agent for powder metallurgy pressing according to claim 1, characterized in that, The discharge port (22) is provided with a cover plate (221) which is hinged to the side wall of the discharge port (22) by a torsion spring (222) and seals the discharge port (22). The cover plate (221) is provided with a magnetic sheet (223). The opening and closing mechanism includes a second electric telescopic rod (6) for opening the discharge port (22) when the container (2) reaches above the cavity (31). The second electric telescopic rod (6) is provided with a magnetic rod (61) with the same magnetism as the magnetic sheet (223). The inner wall of the cavity (31) is provided with a liquid level sensor (32) and a first controller for controlling the retraction of the second electric telescopic rod (6) and controlling the opening and closing of the lifting motor (41). The liquid level sensor (32) and the second electric telescopic rod (6) are both electrically connected to the first controller. The first electric telescopic rod (71) is provided with a second controller for controlling the extension of the second electric telescopic rod (6), and both the first electric telescopic rod (71) and the second electric telescopic rod (6) are electrically connected to the second controller.

5. The method for applying a self-lubricating release agent for powder metallurgy pressing according to claim 1, characterized in that, The first airbag (52) and the second airbag (51) are each fitted with a spring (521) to enhance the restoring elasticity of the first airbag (52) and the second airbag (51).

6. The method for applying a self-lubricating release agent for powder metallurgy pressing according to claim 1, characterized in that, The mold (3) is provided with an elastic block (62) for providing reciprocating elastic force to the brush head (5) after the brush head (5) brushes over the upper punch (4).

7. The method for applying a self-lubricating release agent for powder metallurgy pressing according to claim 1, characterized in that, The container (2), the spiral blade (232), and the stirring rod (231) are all made of stainless steel.

Images