A pen shell mold

Abstract

The application relates to the field of pen shell production molds, in particular to a pen shell mold which comprises a static mold, a dynamic mold and an ejection mechanism, the dynamic mold comprises a first mold and a second mold, a core rod is arranged between the first mold and the second mold, the first mold and the second mold are clamped outside the core rod and are formed with a cavity, the cavity is used for injection molding to form a pen shell, a material inlet for feeding is arranged on the static mold, a flow channel is formed between the material inlet and the cavity, the cross-section diameter of the flow channel is smaller at a position closer to the cavity, the flow channel is communicated on the end part of the cavity, and the ejection mechanism ejects the pen shell from the end part of the cavity. The application has the effect of improving the ejection efficiency of the pen shell and waste materials.

Description

A pen casing mold Technical Field

[0001] This application relates to the field of pen shell production molds, and more particularly to a pen shell mold. Background Technology

[0002] In pen casing production, with increased automation and greater industry transparency, low-profit, high-volume sales have become the mainstream, making production efficiency particularly important. Pen casings are typically injection molded. After injection molding, the pen casing usually needs to be demolded using ejector pins. During this process, there are two methods for handling the pen casing and waste material: one is to eject the pen casing and waste material simultaneously using an ejector pin mechanism, and then cut the waste material from the pen casing; the other is to first fix the waste material in the runner, and then separate it directly from the waste material when the pen casing is ejected by the ejector pin mechanism, and then unload the waste material. This method requires at least two ejector pin mechanisms, one for ejecting the pen casing and one for ejecting the waste material. Therefore, there is a need to develop a mold with a more efficient pen casing demolding method. Summary of the Invention

[0003] To address this issue, this application provides a pen casing mold.

[0004] This application provides a pen shell mold, which adopts the following technical solution:

[0005] A pen shell mold includes a stationary mold, a moving mold, and an ejection mechanism. The moving mold includes a first mold and a second mold. A mandrel is disposed between the first mold and the second mold. The first mold and the second mold are clamped outside the mandrel and form a cavity. The cavity is used for injection molding to form a pen shell. The stationary mold has a sprue for feeding material. A flow channel is formed between the sprue and the cavity. The cross-sectional diameter of the flow channel is smaller the closer it is to the cavity. The flow channel is connected to the end of the cavity. The ejection mechanism ejects the pen shell from the end of the cavity.

[0006] By adopting the above technical solution, material is injected into the cavity through the sprue, and the material is formed onto the mandrel through the cavity. After the material cools and solidifies, the moving mold and the stationary mold are separated, and the first mold and the second mold are opened. Then, the pen shell is ejected from the end of the cavity by the ejection mechanism. During the ejection process, the ejection mechanism directly pushes the pen shell, causing the pen shell to overcome the adhesive and frictional forces between itself and the outer wall of the mandrel. When the waste material formed in the narrow runner overcomes the adhesive and frictional forces between itself and the outer wall of the mandrel, the wide runner also needs to overcome the adhesive and frictional forces between itself and the outer wall of the mandrel. The ejection of the pen shell pushes the narrow runner. The waste material formed is placed on top of the waste material formed in the wide runner. Since the waste material formed in the narrow runner is thinner and the waste material formed in the wide runner is thicker, the waste material will break at the narrow runner due to the pushing force of the pen shell, the adhesive force between itself and the outer wall of the core rod, and the frictional force. Then the pen shell continues to be ejected, ejecting the broken waste material at the same time. This realizes the separation of product and waste material and demolding of product and waste material with one ejection mechanism and one ejection action. It is convenient and fast, greatly improves demolding efficiency, reduces the number of ejection mechanisms, simplifies the ejection action of the ejection mechanism, reduces manufacturing costs, and improves economic benefits.

[0007] Optionally, the flow channel includes a wide flow channel and a narrow flow channel that are connected to each other. The cross-sectional diameter of the narrow flow channel is smaller than that of the wide flow channel. The narrow flow channel is connected to the cavity, and the wide flow channel is connected to the feed port. A stepped surface is formed between the narrow flow channel and the wide flow channel. The waste material formed on the stepped surface is used for ejecting the pen shell.

[0008] By adopting the above technical solution, when the waste material formed in the narrow flow channel breaks due to the thrust and adhesive force, the pen shell continues to be ejected. The end of the pen shell will abut against the waste material sidewall formed on the stepped surface. The waste material sidewall on the stepped surface blocks the ejection of the pen shell. Therefore, the pen shell continues to be ejected and will abut against the waste material sidewall on the stepped surface. The waste material sidewall on the stepped surface will eject the waste material formed in the wide flow channel. At the same time, it will pull out the waste material at the broken point of the waste material formed in the narrow flow channel, making the ejection of the waste material smoother and reducing the impact of the waste material on the pen shell, such as the probability of the waste material falling into the pen shell and causing deformation, thus improving efficiency.

[0009] Optionally, both the narrow flow channel and the wide flow channel extend circumferentially around the mandrel.

[0010] By adopting the above technical solution, while keeping the thickness of the waste material formed in the narrow runner constant, the contact area between the narrow runner and the cavity is expanded, the flow rate of the molten material into the cavity is increased, the flow rate is improved, the injection time is shortened, and the waste material in the narrow runner is made easier to break. The circumferential wrapping makes the molten material injected into the cavity more uniform, resulting in better quality of the pen shell formed in the cavity.

[0011] Optionally, the closer to the flow channel, the larger the opening cross-section of the material inlet, and the material inlet is flared.

[0012] By adopting the above technical solution, the sprue is widened from the sprue towards the runner, making the residual waste in the sprue conical. This facilitates the removal of waste from the sprue during the separation of the moving mold and the stationary mold, reducing the probability of waste remaining in the sprue during separation. This results in more thorough waste removal, further facilitating injection molding and reducing the probability of residual waste entering the cavity with the next injection molding material, causing defects in the finished pen shell. It also reduces the probability of residual waste clogging the narrow runner or other locations with the next injection molding material, thus affecting the material's entry into the cavity. This provides protection for subsequent injection molding processes, improves the yield of pen shells, and protects the equipment.

[0013] Optionally, the flow channel is connected to the inner ring sidewall near the end of the cavity.

[0014] By adopting the above technical solution, the flow channel is connected to the inner ring sidewall near the end of the cavity, so that the waste material connection point in the flow channel is on the inner wall of the cavity. As the pen shell is ejected after molding, the ejection thrust is set perpendicular to the connection direction of the waste material connection point in the flow channel. The force generated at this time is a shear force, which makes the waste material in the flow channel and the pen shell easier to break, and limits the break point. The waste material breaks at the connection point with the pen shell in the cavity due to shear force, which greatly reduces the probability of waste material failure to break. This makes the separation of waste material and pen shell smoother, and allows the equipment to be adapted to materials with lower viscosity for pen shell injection molding, thus expanding the range of materials that can be processed.

[0015] Optionally, a limiting groove is formed on the side wall of the mandrel, the limiting groove is connected to the wide flow channel, and the limiting groove is used to allow material to flow into the molding process.

[0016] By adopting the above technical solution, when the adhesion between the material used and the outer wall of the core rod is weak, the pen shell is directly pushed. The adhesion between the waste material and the outer wall of the core rod is insufficient to block the pushing force of the waste material formed in the narrow flow channel by the pen shell. The waste material will be directly pushed by the pen shell without breaking. At this time, the waste material formed in the limiting groove blocks the waste material formed in the wide flow channel. The waste material formed in the wide flow channel blocks the displacement of the waste material formed in the narrow flow channel, so that the waste material formed in the narrow flow channel is subjected to sufficient blocking force to block the pushing force of the pen shell, thereby breaking the waste material formed in the narrow flow channel and making the separation of the waste material from the pen shell smoother.

[0017] Optionally, a narrow ring block is slidably disposed within the first mold and the second mold, the narrow ring block sliding toward or away from the mandrel, and the narrow flow channel is formed between the narrow ring block and the mandrel.

[0018] By adopting the above technical solution, the narrow ring block is first slid away from the narrow runner, which expands the cross-sectional width of the narrow runner, increases the flow rate of material injection, and improves injection molding efficiency. After injection molding is completed, the narrow ring block is slid again to reduce the cross-sectional width of the narrow runner, so that the waste material at the narrow runner after cooling and molding is thinner and easier to break. Thus, while ensuring injection molding, the waste material at the narrow runner is thinner and easier to break, which greatly improves injection molding efficiency.

[0019] Optionally, the number of narrow ring blocks is several, and a driving plate is slidably disposed in the first mold and the second mold. Several narrow ring blocks are disposed on the driving plate, and the driving plate slides to drive several narrow ring blocks to slide.

[0020] By adopting the above technical solution, synchronous control is achieved by driving the plate to drive several narrow ring blocks to slide simultaneously, reducing the probability of asynchronous control and some narrow ring blocks not sliding on time, which would make it difficult to separate the pen shell from the waste material, thus making the processing smoother.

[0021] In summary, this application includes at least one of the following beneficial technical effects:

[0022] 1. A single ejection mechanism and ejection action are implemented, which can achieve the separation of product and waste, as well as the demolding of product and waste. This is convenient and quick, greatly improving demolding efficiency. It also reduces the number of ejection mechanisms, simplifies the ejection action of the ejection mechanism, reduces manufacturing costs, and improves economic efficiency.

[0023] 2. This allows for smoother separation of waste material from the pen casing, enabling the equipment to handle materials with lower viscosity for pen casing injection molding, thus expanding the range of materials that can be processed. Attached Figure Description

[0024] Figure 1 is a schematic diagram of the overall structure of a pen shell mold assembly according to Embodiment 1 of this application.

[0025] Figure 2 is a schematic diagram of the overall structure of one mold in the mold group of Figure 1.

[0026] Figure 3 is a schematic diagram of the prominent flow channel shown in Figure 2.

[0027] Figure 4 is an enlarged structural diagram of point A in Figure 3.

[0028] Figure 5 is a schematic diagram of the structure highlighting the bend in the narrow flow channel in Embodiment 2 of this application.

[0029] Figure 6 is a schematic diagram of the structure of the protruding limiting groove in Embodiment 3 of this application.

[0030] Figure 7 is a schematic diagram of the structure highlighting the narrow ring block in Embodiment 4 of this application.

[0031] Figure 8 is a schematic diagram of the structure of the drive plate.

[0032] Explanation of reference numerals in the attached drawings: 1. Static mold; 11. Moving mold; 111. Mold groove; 12. Ejection mechanism; 121. Base; 122. Ejector pin; 2. First mold; 21. Second mold; 22. Mandrel; 23. Cavity; 24. Runner; 241. Wide runner; 242. Narrow runner; 25. Stepped surface; 3. Sprue; 31. Limiting groove; 4. Narrow ring block; 41. Moving plate; 42. Sealing groove; 43. Moving groove. Detailed Implementation

[0033] The present application will be further described in detail below with reference to Figures 1-8.

[0034] Embodiment 1 of this application discloses a pen shell mold. Referring to Figures 1 and 2, the pen shell mold includes a stationary mold 1, a movable mold 11, and an ejection mechanism 12. In actual production, several molds are combined into a mold group. The stationary mold 1 has a mold groove 111. The movable mold 11 is inserted into the mold groove 111, and the sidewall of the movable mold 11 abuts against the inner wall of the mold groove 111. The movable mold 11 slides along the depth direction of the mold groove 111. In this embodiment, the direction from the stationary mold 1 along the depth direction of the mold groove 111 to the movable mold 11, and parallel to the sliding direction of the movable mold 11, is the downward direction; the upward direction is the opposite of downward. The left-right direction is perpendicular to the up-down direction.

[0035] Referring to Figure 3, the moving mold 11 includes a first mold 2 and a second mold 21. The outer side walls of the first mold 2 and the second mold 21, which are far apart from each other, abut against and adhere to the inner side walls of the mold groove 111, which face each other. The first mold 2 and the second mold 21 slide in the direction of approaching or moving away from each other, that is, the first mold 2 and the second mold 21 slide in the left and right direction. After the first mold 2 and the second mold 21 approach and abut against each other, they are inserted into the mold groove 111. After the first mold 2 and the second mold 21 exit from the mold groove 111, they separate in the direction of moving away from each other.

[0036] Referring to Figure 4, a mandrel 22 is installed between the first mold 2 and the second mold 21. The inner walls of the first mold 2 and the second mold 21, facing each other, enclose and clamp the mandrel 22. The inner walls of the first mold 2, the second mold 21, and the outer sidewalls of the mandrel 22 enclose and form a cavity 23. The cavity 23 is used to inject molten material into the cavity, where it cools and forms the pen shell. A sprue 3 is provided on the stationary mold 1 for feeding material. A flow channel 24 is formed between the sprue 3 and the cavity 23. Molten material enters the flow channel 24 from the sprue 3 and then enters the cavity 23. The cross-sectional diameter of the flow channel 24 is smaller closer to the cavity 23. The flow channel 24 is connected to the upper inner wall of the cavity 23. The ejection mechanism 12 ejects the pen shell from the end of the cavity 23.

[0037] Referring to Figure 3, the ejection mechanism 12 includes a base 121 and an ejector rod 122. The first mold 2 and the second mold 21 slide on the base 121. The base 121 drives the first mold 2 and the second mold 21 to slide in the vertical direction and in the horizontal direction on the base 121. A retaining ring is fixedly connected to the lower end of the mandrel 22. The diameter of the retaining ring is larger than the cross-sectional diameter of the mandrel 22. The lower end of the mandrel 22 is inserted into the base 121, and the inner wall of the base 121 abuts and engages the retaining ring on the mandrel 22. The cavity 23 extends from top to bottom. The length direction of the mandrel 22 extends from bottom to top, and the length direction of the mandrel 22 is parallel to the sliding direction of the base 121. The sliding direction of the first mold 2 and the second mold 21 is perpendicular to the length direction of the mandrel 22. The central axis of the mandrel 22 coincides with the central axis of the cavity 23.

[0038] Referring to Figure 3, the push rod 122 is sleeved and slides on the outer ring side wall of the mandrel 22. The push rod 122 slides along the length of the mandrel 22, that is, the push rod 122 slides upward to push out the pen shell that is injection molded on the outer ring of the mandrel 22.

[0039] Referring to Figure 4, the flow channel 24 includes a wide flow channel 241 and a narrow flow channel 242 that are connected. In this embodiment, the cross-sectional thickness between the inner and outer sidewalls of the narrow flow channel 242 is only [10 mil, 20 mil]. The waste material formed in the narrow flow channel 242 is used to break the pen shell when it is ejected, thereby separating the pen shell from the waste material. Both the wide flow channel 241 and the narrow flow channel 242 extend from top to bottom. The wide flow channel 241 is connected to the feed port 3, and the cross-sectional diameter of the outer inner wall of the wide flow channel 241 is equal to the opening diameter of the feed port 3. The inner inner wall of the narrow flow channel 242 is connected to the inner inner wall of the wide flow channel 241, that is, the cross-sectional diameter of the inner sidewall of the narrow flow channel 242 is equal to the cross-sectional diameter of the inner sidewall of the wide flow channel 241. The cross-sectional diameter of the outer ring sidewall of the narrow flow channel 242 is smaller than that of the outer ring sidewall of the wide flow channel 241, and the opening of the narrow flow channel 242 away from the wide flow channel 241 is connected to the upper opening of the cavity 23.

[0040] Referring to Figure 4, a stepped surface 25 is formed between the narrow runner 242 and the wide runner 241. The outer edge of the stepped surface 25 is connected to the inner wall of the outer ring of the wide runner 241 with a larger cross-sectional diameter, and the inner edge of the stepped surface 25 is connected to the inner wall of the outer ring of the narrow runner 242 with a smaller cross-sectional diameter. The stepped surface 25 faces the upper end face of the cavity 23, is parallel to the upper inner wall of the cavity 23, and is perpendicular to the ejection direction of the pen shell. After the pen shell is injection molded and ejected upwards, the end of the pen shell will abut against the stepped surface 25 to eject the waste material in the wide runner 241, the narrow runner 242, and the sprue 3.

[0041] Referring to Figure 4, both the narrow flow channel 242 and the wide flow channel 241 extend circumferentially and wrap around the mandrel 22. The outer sidewall of the mandrel 22 serves as the inner sidewall of the narrow flow channel 242 and the wide flow channel 241, meaning that the material is formed on the mandrel 22.

[0042] Referring to Figure 4, the feed port 3 extends from top to bottom, and the closer the feed port 3 is to the flow channel 24, the larger the opening cross section of the feed port 3 is. The feed port 3 is flared from top to bottom.

[0043] The implementation principle of a pen shell mold in Embodiment 1 of this application is as follows: After injection molding is completed, the first mold 2 and the second mold 21 are withdrawn from the mold groove 111, and the waste material in the sprue 3 is removed from the sprue 3. Then the first mold 2 and the second mold 21 are opened in a direction away from each other, exposing the pen shell and the waste material. Then the ejector rod 122 slides out to push the pen shell. The pen shell slides upward to press and break the annular waste material formed at the narrow flow channel 242. Then the end of the pen shell abuts against the stepped side wall of the waste material formed at the stepped surface 25 to eject the waste material formed in the wide flow channel 241 and the sprue 3, and at the same time, the pen shell is unloaded.

[0044] Example 2:

[0045] Unlike Embodiment 1, referring to Figure 5, the narrow flow channel 242 is connected to the inner ring sidewall of the cavity 23 near the end. The narrow flow channel 242 extends downward and is curved. The lower end of the narrow flow channel 242 is curved and connected to the inner wall of the cavity 23.

[0046] Example 3:

[0047] Unlike Embodiment 1, referring to Figure 6, a limiting groove 31 is formed on the outer ring sidewall of the mandrel 22. The limiting groove 31 extends in a ring shape and is circumferentially encircling the outer ring sidewall of the mandrel 22. The limiting groove 31 is located on the inner wall of the wide flow channel 241 and is connected to the wide flow channel 241. The limiting groove 31 is used to allow material to flow into the molding process.

[0048] Example 4:

[0049] Unlike Embodiment 1, referring to Figures 7 and 8, both the first mold 2 and the second mold 21 have sealing grooves 42, which are connected to narrow flow channels 242. The sealing grooves 42 of the first mold 2 extend away from the second mold 21, and the sealing grooves 42 of the second mold 21 extend away from the first mold 2. A narrow ring block 4 slides within the sealing groove 42, and the sidewall of the narrow ring block 4 is in close contact with the inner wall of the sealing groove 42. Under its own tension, the molten material is difficult to enter the gap between the sidewall of the narrow ring block 4 and the sealing groove 42. The narrow ring block 4 slides towards or away from the mandrel 22, and the narrow flow channel 242 is formed between the sidewall of the narrow ring block 4 and the mandrel 22.

[0050] Referring to Figures 7 and 8, the narrow ring block 4 is semi-circular. The narrow ring block 4 of the first mold 2 and the narrow ring block 4 of the second mold 21 slide close to each other until their ends abut. The inner ring sidewalls of the two narrow ring blocks 4 form a complete circle. The narrow flow channel 242 is formed between the inner ring sidewalls of the two narrow ring blocks 4 and the outer ring sidewall of the mandrel 22.

[0051] Referring to Figures 7 and 8, each mold includes two narrow ring blocks 4, and the total number of narrow ring blocks 4 in the entire mold assembly is several. Both the first mold 2 and the second mold 21 have a drive groove 43 extending into the adjacent molds, specifically the first mold 2 and the second mold 21. The length direction of the drive groove 43 is perpendicular to the sliding direction of the first mold 2 and the second mold 21, and also perpendicular to the depth direction of the mold groove 111. A drive plate 41 slides within the drive groove 43, extending along the length direction of the drive groove 43. The sliding direction of the drive plate 41 is parallel to the sliding direction of the first mold 2 and the second mold 21, which are either moving away from or moving closer to each other. Several narrow ring blocks 4 are fixedly connected to the drive plate 41; that is, several narrow ring blocks 4 in the first mold 2 are fixedly connected to the same drive plate 41, and several narrow ring blocks 4 in the second mold 21 are also fixedly connected to the same drive plate 41. The sliding of the drive plate 41 drives the sliding of several narrow ring blocks 4.

[0052] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pen shell mold, comprising a stationary mold (1), a moving mold (11), and an ejection mechanism (12), characterized in that: The moving mold (11) includes a first mold (2) and a second mold (21). A mandrel (22) is disposed between the first mold (2) and the second mold (21). The first mold (2) and the second mold (21) are clamped outside the mandrel (22) and form a cavity (23). The cavity (23) is used for injection molding to form a pen shell. The stationary mold (1) has a sprue (3) for feeding material. A flow channel (24) is formed between the sprue (3) and the cavity (23). The flow channel (24) has a smaller cross-sectional diameter closer to the cavity (23). The flow channel (24) is connected to the end of the cavity (23). The ejection mechanism (12) ejects the pen shell from the cavity (23). The end of the core rod (24) is ejected; the flow channel (24) includes a wide flow channel (241) and a narrow flow channel (242) that are connected. The cross-sectional diameter of the narrow flow channel (242) is smaller than that of the wide flow channel (241). The narrow flow channel (242) is connected to the cavity (23). The wide flow channel (241) is connected to the material port (3). A stepped surface (25) is formed between the narrow flow channel (242) and the wide flow channel (241). The waste material formed on the stepped surface (25) is used for ejecting the pen shell. A limiting groove (31) is opened on the side wall of the core rod (22). The limiting groove (31) is connected to the wide flow channel (241). The limiting groove (31) is used for material to flow into the molding.

2. The pen shell mold according to claim 1, characterized in that: Both the narrow flow channel (242) and the wide flow channel (241) extend circumferentially around the core rod (22).

3. A pen shell mold according to claim 1, characterized in that: The closer to the flow channel (24), the larger the opening cross section of the material port (3), and the material port (3) is flared.

4. A pen shell mold according to claim 1, characterized in that: The flow channel (24) is connected to the inner ring sidewall near the end of the cavity (23).

5. A pen shell mold according to claim 1, characterized in that: Narrow ring blocks (4) are slidably disposed within the first mold (2) and the second mold (21). The narrow ring blocks (4) slide toward or away from the mandrel (22). The narrow flow channel (242) is formed between the narrow ring blocks (4) and the mandrel (22).

6. A pen shell mold according to claim 5, characterized in that: The number of narrow ring blocks (4) is several. A driving plate (41) is slidably arranged inside the first mold (2) and the second mold (21). Several narrow ring blocks (4) are arranged on the driving plate (41). The driving plate (41) slides to drive several narrow ring blocks (4) to slide.

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