Electronic pen tube forming method

Abstract

The invention discloses an electronic pen tube forming method which comprises a forming mold, the forming mold comprises a female mold core and a male mold core, an electronic pen tube cavity is formed after the female mold core and the male mold core are closed, and the electronic pen tube forming method comprises the specific steps that S100, electric discharge machining is conducted on the female mold core and the male mold core through an electric discharge machine; s200, the female mold core and the male mold core are installed in a female mold plate and a male mold plate corresponding to a forming mold, the female mold and the male mold are closed to form a cavity of the electronic pen tube, and an injection molding machine injects a molten material into the forming mold into the cavity; s300, a driving screw of the injection molding machine is pressurized, the holding pressure is set to be 1200 kgf / cm < 2 >, and the holding time is 5 min; and S400, the female mold and the male mold are opened, and the product is taken out. According to the method, the female mold core and the male mold core are subjected to electric discharge machining through the electric discharge machine, so that the precision of the female mold core and the male mold core is improved, and the parting line segment difference of the product can be improved.

Description

Technical Field

[0001] The invention relates to the field of injection molding, and in particular to a method for molding an electronic pen tube. Background Art

[0002] At present, the injection molding process is mainly used in the production of electronic pen tubes. During the current injection molding process, the feed channel is mostly set at the pen tip end of the cavity, and the injection speed and pressure during injection molding are basically unchanged. This processing technology will cause the product to be deformed by more than 0.2mm after injection molding, so it must undergo secondary processing and correction, which is time-consuming and labor-intensive. At the same time, due to the unstable process step of the product, the deformation will be repeated due to heat energy in the subsequent coating process, resulting in waste of resources and increased costs. Summary of the invention

[0003] The technical problem solved by the present invention is to provide an electronic pen tube forming method which can improve product precision and reduce the mold repair frequency caused by product step difference.

[0004] The technical solution adopted by the present invention to solve the technical problem is: an electronic pen tube molding method, including a molding mold, the molding mold includes a female mold core and a male mold core, the female mold core and the male mold core are molded together to form an electronic pen tube cavity, and the specific steps are:

[0005] S100: EDM the female mold core and the male mold core by using an EDM machine;

[0006] S200: installing the female mold core and the male mold core into the female mold plate and the male mold plate corresponding to the molding mold, closing the female mold and the male mold to form a mold cavity of the electronic pen tube, and the injection molding machine injects molten material into the mold cavity into the molding mold;

[0007] The injection molding machine includes a driving screw, wherein the first 0-20-22% of the driving screw movement is the first molding stage, the 20-22%-74-75% of the screw movement is the second molding stage, and the 74-75%-100% of the screw movement is the third molding stage. The movement speed of the first molding stage is 170-190 mm / s, the movement speed of the second molding stage is 280-300 mm / s, the movement speed of the first molding stage is 60-70 mm / s, and the pressure is set to 2500-2700 kgf / cm 2 ;

[0008] S300: Pressurize the drive screw of the injection molding machine and set the holding pressure to 1100-1300kgf / cm 2 , holding time 0.5s;

[0009] S400: The female mold and the male mold are opened and the product is taken out.

[0010] Furthermore, the molding mold includes a female mold and a male mold, a female mold core is arranged in the female mold, a male mold core is arranged in the male mold, and a core pulling mechanism is also arranged on one side of the female mold and the male mold, the core pulling mechanism includes an inner core extending between the female mold core and the male mold core and an inner core driving mechanism driving the inner core to extend and withdraw, the inner core driving mechanism is fixedly connected to the male mold, a cooling water channel structure is arranged in the inner core, a cooling water connecting port is arranged on the side of the male mold, the cooling water channel structure is connected to the cooling water connecting port through a water channel pipe, and when the female mold and the male mold are closed, the female mold core, the male mold core and the inner core together constitute the electronic pen tube cavity, and a feed inlet is arranged on the female mold, and the feed inlet is connected to the electronic pen tube cavity through a feed channel.

[0011] Furthermore, the electronic pen tube cavity and its corresponding inner core have multiple cooling water path structures, the multiple inner cores are connected end to end, and further include a water inlet pipe and a water outlet pipe, the water inlet pipe and the water outlet pipe are respectively connected to the water inlet end and the water outlet end of the cooling water path structure connected end to end;

[0012] The inner core driving mechanism includes a mounting block and a driving cylinder, one end of the inner core is connected to the mounting block, one end of the water inlet pipe and the water outlet pipe are arranged on the mounting block, a connecting water channel structure, a connecting water channel of the water inlet pipe and the water outlet pipe are arranged in the mounting block, and the driving end of the driving cylinder is fixedly connected to the mounting block.

[0013] Furthermore, the inner core and the cooling water channel structure therein are made by 3D printing technology.

[0014] Furthermore, a first inclined surface structure is arranged on one side of the mounting block, and the mounting block further comprises a positioning block installed on the female mold, wherein a second inclined surface matching with the first inclined surface is arranged on the positioning block, and when the female mold and the male mold are closed, the first inclined surface and the second inclined surface abut against each other.

[0015] Furthermore, feed ports are respectively arranged on both sides of the electronic pen tube cavity away from the pen head, and the feed ports are connected with the feed port on the mother mold through a feed flow channel.

[0016] Furthermore, an ejector plate is arranged on the side of the male mold away from the female mold, and an ejector that can extend into the cavity of the electronic pen tube is arranged on the ejector plate.

[0017] Furthermore, in step S100, the female mold core and the male mold core are subjected to electrical discharge machining by an electrical discharge machine, specifically:

[0018] S101: placing the female mold core and the male mold core in a discharge machine;

[0019] S102: Use machining electrodes of corresponding shapes to perform electrical discharge machining on the female mold core and the male mold core respectively. First, perform electrical discharge rough machining with a current of 3-5A and a reserved width of 0.04mm for the mold core. Then perform electrical discharge finishing machining with a finishing current of 1-2A and a reserved width of 0.01mm for the mold core.

[0020] The beneficial effects of the present invention are:

[0021] 1. In this method, the female mold core and the male mold core are processed by an electric discharge machine, thereby improving the accuracy of the female mold core and the male mold core, thereby improving the parting line segment difference of the product.

[0022] 2. In this method, the injection speed and pressure of the injection molding machine are controlled in sections, so that the deformation degree of the balance pen tube can be adjusted and the generation of balance stress can be balanced, so that the injection molding material is more uniform in the product cavity.

[0023] 3. This method avoids the imbalance of glue feeding caused by extrusion-type glue feeding due to excessive flow length ratio by feeding the material from the end far away from the pen tip, reduces its dependence on clamping force, and effectively avoids the distortion caused by high pressure on the parting surface, which causes a large parting step difference.

[0024] 4. In this method, a cooling water channel structure is set in the inner core, so that the stress trend generated when the product is solidified in the cavity can be effectively controlled, thereby balancing and stabilizing the eccentric deformation. At the same time, through the coordinated use of the injection molding machine, the eccentricity and step difference of the product can be stabilized and controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the process of the electronic pen tube forming method according to an embodiment of the present application.

[0026] Figure 2 This is a schematic structural diagram of a molding die according to an embodiment of the present application.

[0027] Figure 3 This is a schematic diagram of the internal structure of the molding mold according to an embodiment of the present application.

[0028] Figure 4 This is a schematic diagram of the male mold structure of the molding mold according to an embodiment of the present application.

[0029] Figure 5 This is a schematic diagram of the inlet channel structure of the molding mold according to an embodiment of the present application.

[0030] Figure 6 This is a schematic diagram of the inner core structure of the molding mold according to an embodiment of the present application.

[0031] Figure 7 Schematic diagram of the cooling water channel structure of the molding mold according to an embodiment of the present application.

[0032] Figure 8 It is a schematic diagram of the mother mold core structure of the molding mold according to an embodiment of the present application.

[0033] The markings in the figure are:

[0034] Female mold 1, female mold core 101, feed port 102, feed channel 103, male mold 2, male mold core 201, feed port 202, ejector plate 204, core pulling mechanism 3, inner core 301, driving cylinder 302, water inlet pipe 303, water outlet pipe 304, mounting block 305, positioning block 306, first inclined surface 307, second inclined surface 308, cooling water channel structure 309, product 4. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] like Figure 1 As shown, the embodiment of the present application discloses an electronic pen tube molding method, including a molding mold, wherein the molding mold includes a female mold core 101 and a male mold core 201, and the female mold core 101 and the male mold core 201 are molded together to form an electronic pen tube cavity, and the specific steps are:

[0037] S100: Discharge machining is performed on the female mold core 101 and the male mold core 201 by an electric discharge machine;

[0038] S200: Install the female mold core 101 and the male mold core 201 into the female mold 1 and the male mold 2 corresponding to the molding mold, close the female mold 1 and the male mold 2 to form a cavity of the electronic pen tube, and the injection molding machine injects molten material into the cavity into the molding mold;

[0039] The injection molding machine includes a driving screw, wherein the first 0-20-22% of the driving screw movement is the first molding stage, the 20-22%-74-75% of the screw movement is the second molding stage, and the 74-75%-100% of the screw movement is the third molding stage. The movement speed of the first molding stage is 170-190 mm / s, the movement speed of the second molding stage is 280-300 mm / s, the movement speed of the first molding stage is 60-70 mm / s, and the pressure is set to 2500-2700 kgf / cm 2 ;

[0040] S300: Pressurize the drive screw of the injection molding machine and set the holding pressure to 1100-1300kgf / cm 2 , holding time: 0.5s;

[0041] S400: The female mold 1 and the male mold 2 are opened, and the product 4 is taken out.

[0042] It should be explained that the discharge machine and injection molding machine are both mature existing equipment, and no improvement is made to them in this application. The improvement points for the discharge machine and injection molding machine in this application lie in the setting of various performance parameters when using the discharge machine and injection molding machine.

[0043] Specifically, the following is a specific embodiment of the setting of the injection molding machine in the present application. When the molten injection molding material is injected into the electronic pen tube cavity, the front end of the driving screw needs to move from position 28mm to position 4.4mm. First, the front end of the screw is driven from position 28mm to position 28mm at a speed of 180mm / s, and then the front end of the screw is driven from position 23mm to position 5.5mm at a speed of 290mm / s. Finally, the front end of the screw is driven from position 5.5mm to position 4.4mm at a speed of 650mm / s.

[0044] In the above method, the speed is divided into three sections, so that the molten material enters the electronic pen tube cavity at different speeds, thereby making the molten material fill the electronic pen tube cavity more uniformly.

[0045] In this method, the female mold core 101 and the male mold core 201 are processed by an electric discharge machine, thereby improving the accuracy of the female mold core 101 and the male mold core 201, thereby improving the parting line segment difference of the product 4. At the same time, in this method, the injection speed and pressure of the injection molding machine are controlled in sections, thereby adjusting the deformation degree of the balance pen tube and balancing the generation of stress, so that the injection material is more uniform in the product cavity.

[0046] In this embodiment, in step S100, the female mold core 101 and the male mold core 201 are subjected to electrical discharge machining by an electrical discharge machine, specifically:

[0047] S101: placing the female mold core 101 and the male mold core 201 in a discharge machine;

[0048] S102: Use machining electrodes of corresponding shapes to perform discharge machining on the female mold core 101 and the male mold core 201 respectively. First, perform discharge rough machining with a current of 3-5A and a mold core reserved width of 0.04mm. Then perform discharge finishing machining with a finishing current of 1-2A and a mold core reserved width of 0.01mm.

[0049] At the same time, during discharge machining, the following parameters are also set: set cycle 5, jump amplitude 15, shaking method 1111, discharge surface texture VDI 18, and during the discharge machining process, the moving coordinates of the machining electrode are moved and discharged in the standard coordinates of the drawing according to the positive and negative of the three-dimensional measurement data. Therefore, the male mold core 201 and the female mold core 101 produced by discharge machining are consistent in size, and the product 4 produced subsequently has no discontinuity.

[0050] The above-mentioned settings are all standard parameters of the discharge machine. The above-mentioned shaking method 1111 refers to spherical shaking, that is, the electrodes are discharging up, down, left and right.

[0051] In this embodiment, Figures 2 to 4 As shown, the molding mold includes a female mold 1 and a male mold 2, the female mold 1 is provided with a female mold core 101, the male mold 2 is provided with a male mold core 201, and the female mold 1 and the male mold 2 are further provided with a core pulling mechanism 3 on one side, the core pulling mechanism 3 includes an inner core 301 extending between the female mold core 101 and the male mold core 201 and an inner core 301 driving mechanism for driving the inner core 301 to extend and withdraw, and the inner core 301 driving mechanism is fixedly connected to the male mold 2 A cooling water channel structure 309 is provided in the inner core 301, and a cooling water connection port is provided on the side of the male mold 2. The cooling water channel structure 309 is connected to the cooling water connection port through a water channel pipe. When the female mold 1 and the male mold 2 are molded together, the female mold core 101, the male mold core 201 and the inner core 301 together constitute the electronic pen tube cavity. A feed port 102 is provided on the female mold 1, and the feed port 102 is connected to the electronic pen tube cavity through a feed channel 103.

[0052] It should be explained that, specifically, during injection molding, the inner core 301 driving mechanism drives the inner core 301 to extend into the public mold 2, and then the female mold 1 and the public mold 2 are closed, so that the female mold core 101, the public mold core 201 and the inner core 301 together constitute the electronic pen tube cavity, and then, the injection molding machine injects the molten material into the electronic pen tube cavity, and at the same time, the cooling enters the cooling water channel structure 309 in the inner core 301, so that the product 4 is cooled and solidified. When the product 4 is cooled and formed, the female mold 1 rises, and the inner core 301 is pulled out under the drive of the inner core 301 driving mechanism, so that the molded product 4 can be unloaded.

[0053] In this structure, the temperature control is balanced to fill the spiral difference through the setting of the cooling water channel structure 309. At the same time, the cooling water channel structure 309 in the inner core 301 is independently temperature-controlled and can effectively control the stress trend generated by the product 4 during mold curing, thereby ensuring the injection molding accuracy of the product 4.

[0054] In this embodiment, Figure 6 and Figure 7 As shown, the electronic pen tube cavity and its corresponding inner core 301 have multiple cooling water path structures 309 of the multiple inner cores 301 are connected end to end, and also include a water inlet pipe 303 and a water outlet pipe 304, and the water inlet pipe 303 and the water outlet pipe 304 are respectively connected to the water inlet end and the water outlet end of the cooling water path structure 309 connected end to end;

[0055] The inner core 301 driving mechanism includes a mounting block 305 and a driving cylinder 302. One end of the inner core 301 is connected to the mounting block 305. One end of the water inlet pipe 303 and the water outlet pipe 304 are arranged on the mounting block 305. A connecting water channel structure and a connecting water channel between the water inlet pipe 303 and the water outlet pipe 304 are arranged in the mounting block 305. The driving end of the driving cylinder 302 is fixedly connected to the mounting block 305.

[0056] Specifically, the inner core 301 and the cooling water channel structure 309 therein are made by 3D printing technology. Other production processes may also be used to produce the inner core 301 structure. However, when the inner core 301 is produced by 3D printing technology, the process is simpler and the produced inner core 301 also has good precision.

[0057] Specifically, when performing the injection molding operation, cooling water enters the cooling water path structure 309 from the water inlet pipe 303, flows through multiple inner cores 301 in sequence, and finally flows out from the water outlet pipe 304. When the product 4 is cooled and formed, the mother mold 1 rises, and the driving cylinder 302 drives the mounting block 305 to retreat, so that the inner core 301 is completely withdrawn from the electronic pen tube cavity. At this time, the molded product 4 can be unloaded.

[0058] In this structure, when multiple molding points are provided, the cooling water channel structures 309 in the multiple molding points are interconnected end to end, so that the cooling water channel structure 309 in the entire molding mold core 301 has only one water inlet and one water outlet, thereby simplifying the design structure of the entire mold.

[0059] In this embodiment, Figure 6 As shown, a first inclined surface 307 structure is provided on one side of the mounting block 305, and the mounting block 305 also includes a positioning block 306 installed on the female mold 1, and a second inclined surface 308 matching the first inclined surface 307 is provided on the positioning block 306. When the female mold 1 and the male mold 2 are closed, the first inclined surface 307 and the second inclined surface 308 abut against each other.

[0060] Specifically, during the mold closing operation, the inner core 301 driving mechanism drives the inner core 301 to extend into the male mold 2, and then the female mold 1 and the male mold 2 are closed. When the female mold 1 moves toward the male mold 2, the second inclined surface 308 on the positioning block 306 will gradually contact the first inclined surface 307. When the female mold 1 moves into place, the first inclined surface 307 and the second inclined surface 308 are completely abutted.

[0061] In this structure, through the coordinated design of the positioning block 306, the first bevel 307 and the second bevel 308, even if the inner core 301 has not moved into place during the mold closing operation, after the female mold 1 moves toward the male mold 2, the second bevel 308 will give a thrust to the first bevel 307 to push the inner core 301 into place, thereby ensuring the accuracy of the produced product 4.

[0062] In this embodiment, Figure 8 As shown, feed ports 202 are respectively provided on both sides of the electronic pen tube cavity away from the pen tip, and the feed ports 202 are connected with the feed port 102 on the mother mold 1 through a feed channel 103 .

[0063] Specifically, during the injection molding process, the molten material is injected into the electronic pen tube cavity through the feed port 102 , and flows into the electronic pen tube cavity through the two sides of the electronic pen away from the pen tip.

[0064] In this structure, by designing the feed flow channel, the molten material is fed from the end away from the pen tip, thereby avoiding the imbalance of glue feeding caused by extrusion-type glue feeding due to excessive flow length ratio, reducing its dependence on clamping force, and effectively avoiding the distortion caused by high pressure on the parting surface, which causes a large parting step difference.

[0065] In this embodiment, an ejector plate 204 is provided on the side of the male mold 2 away from the female mold 1 , and an ejector that can extend into the cavity of the electronic pen tube is provided on the ejector plate 204 .

[0066] Specifically, after the product 4 is solidified, the mother mold 1 rises, and the inner core 301 is pulled out under the drive of the inner core 301 driving mechanism, and then the ejector plate 204 rises, and the ejector on the ejector plate 204 extends into the electronic pen tube cavity to eject the product 4 from the electronic pen tube cavity.

[0067] In the above structure, the setting of the ejector pin can realize that after the product 4 is solidified and formed, it can be quickly ejected from the cavity, thereby realizing rapid material discharge.

[0068] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An electronic pen tube forming method, characterized in that: The method comprises a molding die, wherein the molding die comprises a female mold core (101) and a male mold core (201), and the female mold core (101) and the male mold core (201) are molded together to form an electronic pen tube cavity. The specific steps are as follows: S100: performing electrical discharge machining on the female mold core (101) and the male mold core (201) by using an electrical discharge machine; S200: installing the female mold core (101) and the male mold core (201) into the female mold (1) and the male mold (2) corresponding to the molding mold, the female mold (1) and the male mold (2) are closed to form a mold cavity of the electronic pen tube, and the injection molding machine injects molten material into the mold cavity into the molding mold; The injection molding machine includes a driving screw, wherein the first 0-20-22% of the driving screw movement is the first molding stage, the 20-22%-74-75% of the screw movement is the second molding stage, and the 74-75%-100% of the screw movement is the third molding stage. The movement speed of the first molding stage is 170-190 mm / s, the movement speed of the second molding stage is 280-300 mm / s, the movement speed of the first molding stage is 60-70 mm / s, and the pressure is set to 2500-2700 kgf / cm 2 ; S300: Pressurize the drive screw of the injection molding machine and set the holding pressure to 1100-1300kgf / cm 2 , holding time 0.5s; S400: The female mold (1) and the male mold (2) are opened, and the product (4) is taken out.

2. The electronic pen tube forming method according to claim 1, characterized in that: The molding die comprises a female die (1) and a male die (2); a female die core (101) is arranged in the female die (1), and a male die core (201) is arranged in the male die (2); a core pulling mechanism (3) is also arranged on one side of the female die (1) and the male die (2); the core pulling mechanism (3) comprises an inner core (301) extending between the female die core (101) and the male die core (201) and an inner core (301) driving mechanism for driving the inner core (301) to extend and withdraw; the inner core (301) driving mechanism is fixed to the male die (2) The inner core (301) is provided with a cooling water channel structure (309), and the side of the male mold (2) is provided with a cooling water connection port. The cooling water channel structure (309) is connected to the cooling water connection port through a water channel pipe. When the female mold (1) and the male mold (2) are molded together, the female mold core (101), the male mold core (201) and the inner core (301) together form an electronic pen tube cavity. The female mold (1) is provided with a feed inlet (102), and the feed inlet (102) is connected to the electronic pen tube cavity through a feed flow channel (103).

3. The electronic pen tube forming method according to claim 2, characterized in that: The electronic pen tube cavity and its corresponding inner core (301) are provided with a plurality of cooling water channel structures (309) connected end to end, and further comprising a water inlet pipe (303) and a water outlet pipe (304), wherein the water inlet pipe (303) and the water outlet pipe (304) are respectively connected to the water inlet end and the water outlet end of the cooling water channel structure (309) connected end to end; The inner core (301) driving mechanism comprises a mounting block (305) and a driving cylinder (302); one end of the inner core (301) is connected to the mounting block (305); one end of the water inlet pipe (303) and the water outlet pipe (304) are arranged on the mounting block (305); a connecting water channel structure and a connecting water channel of the water inlet pipe (303) and the water outlet pipe (304) are arranged in the mounting block (305); and the driving end of the driving cylinder (302) is fixedly connected to the mounting block (305).

4. The electronic pen tube forming method according to claim 3, characterized in that: The inner core (301) and the cooling water channel structure (309) therein are manufactured by a 3D printing process.

5. The electronic pen tube forming method according to claim 3, characterized in that: The mounting block (305) is provided with a first inclined surface (307) structure on one side, and further comprises a positioning block (306) mounted on the female mold (1), wherein the positioning block (306) is provided with a second inclined surface (308) cooperating with the first inclined surface (307), and when the female mold (1) and the male mold (2) are molded together, the first inclined surface (307) and the second inclined surface (308) are in contact with each other.

6. The electronic pen tube forming method according to claim 2, characterized in that: Feed ports (202) are respectively provided on both sides of the electronic pen tube cavity away from the pen tip, and the feed ports (202) are connected to the feed port (102) on the mother mold (1) through a feed channel (103).

7. The electronic pen tube forming method according to claim 2, characterized in that: An ejector plate (204) is arranged on the side of the male mold (2) away from the female mold (1), and an ejector pin capable of extending into the cavity of the electronic pen tube is arranged on the ejector plate (204).

8. The electronic pen tube forming method according to claim 1, characterized in that: In the step S100, the female mold core (101) and the male mold core (201) are subjected to electrical discharge machining by an electrical discharge machine, specifically: S101: placing the female mold core (101) and the male mold core (201) in a discharge machine; S102: Discharge machining is performed on the female mold core (101) and the male mold core (201) respectively using machining electrodes of corresponding shapes, firstly performing rough discharge machining with a current of 3-5A and a reserved width of 0.04mm for the mold core, and then performing fine discharge machining with a fine current of 1-2A and a reserved width of 0.01mm for the mold core.

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