Convenient color changing structure of needle valve type hot nozzle

Abstract

The utility model discloses a convenient color changing structure of a needle valve type hot nozzle, which comprises a hot nozzle body, and the lower end of a runner in the hot nozzle body is communicated with the upper end of a mounting cavity; a discharging channel is formed in a sleeve body of the sprue sleeve, the lower portion of the valve needle is located in the discharging channel, a discharging channel inlet edge is formed in the connecting position of the upper end face of the sleeve body and the upper end of the discharging channel, an external thread part is formed on the sleeve body, and an axial positioning step is formed between the upper end of the installation cavity and the lower end of the runner. An inner thread part is formed in the mounting cavity, the inner thread part and the outer thread part are in matched threaded connection, an included angle is formed between the upper end face of the sleeve body and the axial positioning step, and the lower opening edge of the runner is connected with the inlet edge of the discharging channel in an aligned and attached mode. A filling port matched with the lower end of the valve needle is formed in the lower end of the discharging channel; the color changing device is beneficial to shortening the color changing process, improving the production efficiency and reducing the production cost.

Description

Technical Field

[0001] The utility model relates to the field of hot runner injection molds, in particular to a needle valve type hot nozzle convenient color changing structure. Background Art

[0002] At present, the hot runner injection mold is an injection mold equipped with a heating device to keep the plastic in the runner in a molten state. The hot runner includes a hot nozzle for injecting the molten plastic into the cavity. The hot nozzle includes a body, a sprue sleeve and a nozzle core. Figure 6 As shown, the upper part of the sprue sleeve and the upper part of the nozzle core 5 are installed in the lower part of the body, the sprue sleeve is set outside the lower part of the nozzle core 5, and the lower end of the nozzle core 5 is formed with a discharge port, which is connected with the injection port in the lower end of the sprue sleeve, and the injection port is connected with the mold cavity. The lower end of the valve needle (by moving up and down) can close or open the injection port, that is, the valve needle will contact the inner wall of the injection port, and the lower end of the sprue sleeve is adapted to be inserted into the gate of the mold body 3. The replacement cost of the mold body 3 is very high after it is worn, and the above arrangement avoids frictional contact between the valve needle and the mold body; during the injection molding process, due to the pressure of the molten plastic The force is very high, so molten plastic may penetrate between the body and the nozzle core 5, and between the lower end of the nozzle core 5 and the gate sleeve; when it is necessary to replace plastics of different colors, the nozzle core needs to be disassembled to clean the plastic that has penetrated into the gaps, otherwise the color of the new color plastic product will not match the setting, or a large amount of new color material needs to be discharged to remove the original color material retained in the dead corner of the hot nozzle. In other words, the more parts the hot nozzle has, the more complex the assembly structure is, the more gaps that can penetrate the molten plastic, and the longer the working time is spent when changing colors. Therefore, it is necessary to improve the hot nozzle structure of the prior art. Summary of the invention

[0003] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a needle valve type hot nozzle convenient color changing structure, which is conducive to shortening the color changing process, improving production efficiency and reducing production costs.

[0004] The purpose of the utility model is achieved through the following technical solutions.

[0005] The utility model discloses a needle valve type hot nozzle convenient color changing structure, comprising a hot nozzle body, a flow channel is formed in the hot nozzle body, a mounting cavity is formed in the lower end of the hot nozzle body, the lower end of the flow channel is connected to the upper end of the mounting cavity; wherein, it also includes a gate sleeve and a valve needle, the gate sleeve comprises a sleeve body, a discharge channel is formed in the sleeve body, the upper part of the valve needle is located in the flow channel, the lower part of the valve needle is located in the discharge channel, the upper end of the sleeve body is formed with an upper end surface of the sleeve body, the connection between the upper end surface of the sleeve body and the upper end of the discharge channel forms an inlet edge of the discharge channel, the sleeve body is formed with an external threaded portion, the upper end of the mounting cavity An axial positioning step is formed between the lower end of the flow channel, and a lower opening edge of the flow channel is formed at the connection between the axial positioning step and the lower end of the flow channel. The mounting cavity is formed with an internal threaded portion, and the internal threaded portion is threadedly adapted to the external threaded portion. The upper end surface of the sleeve is arranged corresponding to the axial positioning step, and the upper end surface of the sleeve and the axial positioning step form an included angle. The lower opening edge of the flow channel is aligned and closely connected with the inlet edge of the discharge channel, and a positioning nozzle end for adapting to a specific gate of the mold is formed at the lower end of the discharge channel, and an injection port matching the lower end of the valve needle is formed at the lower end of the discharge channel, and the injection port is located within the positioning nozzle end.

[0006] Preferably, the upper end surface of the sleeve is set to be a right-positioned conical surface, and the axial positioning step is set to be a plane.

[0007] Preferably, the angle formed by the upper end surface of the sleeve and the axial positioning step is set to 0.5° to 1°.

[0008] Preferably, an upper positioning inner cylindrical surface and a lower positioning inner cylindrical surface are formed in the mounting cavity, the upper positioning inner cylindrical surface is arranged between the axial positioning step and the upper end of the internal threaded portion, the lower positioning inner cylindrical surface is arranged at the lower side of the lower end of the internal threaded portion, an upper shaft neck and a lower shaft neck are formed on the outside of the sleeve, the external threaded portion is arranged between the upper shaft neck and the lower shaft neck, the outer diameter of the lower shaft neck is larger than the major diameter of the external threaded portion, the minor diameter of the external threaded portion is larger than the outer diameter of the upper shaft neck, the upper shaft neck is adaptively connected to the upper positioning inner cylindrical surface, and the lower shaft neck is adaptively connected to the lower positioning inner cylindrical surface.

[0009] Preferably, a flange portion is formed on the outside of the sleeve body, a groove is formed on the flange portion, the flange portion is formed on the lower side of the lower journal, and the flange portion is located on the lower side of the lower end surface of the hot nozzle body.

[0010] Preferably, a guide cone portion is formed at the upper end of the upper journal.

[0011] Compared with the prior art, the utility model has the following beneficial effects: by arranging a gate sleeve and a valve needle, a discharge channel inlet edge is formed at the connection between the upper end surface of the sleeve and the upper end of the discharge channel, the sleeve is formed with an external threaded portion, a flow channel lower edge is formed at the connection between the axial positioning step of the hot nozzle body and the lower end of the flow channel, the mounting cavity is formed with an internal threaded portion, the internal threaded portion and the external threaded portion are adapted to be screwed together, the upper end surface of the sleeve and the axial positioning step form an angle, the flow channel lower edge is aligned and closely connected with the discharge channel inlet edge, and a positioning nozzle end is formed at the lower end of the sleeve for adapting to the specific gate of the mold, thereby avoiding the need to arrange a nozzle core part and reducing the gap into which molten plastic can penetrate. The above arrangement can greatly improve the sealing connection effect between the flow channel lower edge and the discharge channel inlet edge, so the utility model is conducive to shortening the color changing process, improving production efficiency, and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional structural schematic diagram of the color-changing structure of the utility model.

[0013] Figure 2 for Figure 1 Schematic diagram of the local structure at point A.

[0014] Figure 3 It is a schematic cross-sectional structure diagram of the hot nozzle body of the utility model.

[0015] Figure 4 It is a schematic cross-sectional structure diagram of the gate sleeve of the utility model.

[0016] Figure 5 It is a schematic diagram of the specific cross-sectional local structure of the model.

[0017] Figure 6 The figure is a schematic cross-sectional view of a combination of a hot nozzle and a mold body in the prior art.

[0018] Explanation of reference numerals: nozzle body 1; flow channel 11; flow channel lower opening edge 111; mounting cavity 12; upper positioning inner cylindrical surface 121; axial positioning step 1211; internal threaded portion 122; lower positioning inner cylindrical surface 123; gate sleeve 2; sleeve body 20; upper journal 201; guide cone portion 2011; external threaded portion 202; lower journal 203; flange portion 204; slot 2041; positioning nozzle end 205; injection port 2051; sleeve body upper end surface 200; discharge channel 21; discharge channel inlet edge 2101; mold body 3; cavity 31; gate 311; valve needle 4; nozzle core 5. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings.

[0020] The needle valve type hot nozzle of the utility model has a convenient color changing structure, such as Figure 1As shown, it includes a hot nozzle body 1, as Figure 3 As shown, a flow channel 11 is formed in the nozzle body 1 , a mounting cavity 12 is formed in the lower end of the nozzle body 1 , and the lower end of the flow channel 11 is connected to the upper end of the mounting cavity 12 .

[0021] like Figure 1 As shown, the needle valve type hot nozzle convenient color change structure of the utility model also includes a gate sleeve 2 and a valve needle 4, such as Figure 4 As shown, the sprue sleeve 2 includes a sleeve body 20, and a discharge channel 21 is formed in the sleeve body 20. Figure 1 As shown, the upper part of the valve needle 4 is located in the flow channel 11, and the lower part of the valve needle 4 is located in the discharge channel 21. Figure 4 As shown, the upper end of the sleeve body 20 is formed with a sleeve upper end surface 200, and the connection between the sleeve upper end surface 200 and the upper end of the discharge channel 21 forms an inlet edge 2101 of the discharge channel, and the sleeve body 20 is formed with an external threaded portion 202; Figure 3 As shown, an axial positioning step 1211 is formed between the upper end of the installation cavity 12 and the lower end of the flow channel 11, and a flow channel lower opening edge 111 is formed at the connection between the axial positioning step 1211 and the lower end of the flow channel 11, and the installation cavity 12 is formed with an internal thread portion 122. Figure 1 As shown, the internal threaded portion 122 and the external threaded portion 202 are threadedly connected. Figure 1 and Figure 2 As shown, the upper end surface 200 of the sleeve is arranged corresponding to the axial positioning step 1211, and the upper end surface 200 of the sleeve and the axial positioning step 1211 form an angle (that is, Figure 2 The angle dimension "X" in the figure is 1 / 2"), the lower opening edge 111 of the flow channel is aligned and connected with the inlet edge 2101 of the discharge channel, that is, the inner diameter of the lower end of the flow channel 11 is equal to the inner diameter of the upper end of the discharge channel 21, and the lower end of the flow channel 11 is coaxially arranged with the upper end of the discharge channel 21, so that the lower end of the flow channel 11 transitions straightly to the upper end of the discharge channel 21 (at Figure 2 ). Figure 1 , Figure 4 and Figure 5 As shown, the lower end of the sleeve body 20 is formed with a positioning nozzle end 205 for adapting to the gate 311 of the mold body 3. Specifically, the mold body 3 is formed with a cavity 31, and the gate 311 is located at the bottom end of the cavity 31. The gate 311 is connected to the mold cavity of the mold body 3. Figure 1 As shown, the lower part of the nozzle body 1 is located in the concave cavity 31. Figure 1 and Figure 4 As shown, the lower end of the discharge channel 21 is formed with an injection port 2051 matching the lower end of the valve needle 4, so the injection port 2051 is funnel-shaped and is located within the positioning nozzle end 205. Figure 1As shown, the lower end of the valve needle 4 contacts the inner wall of the injection port 2051, thereby closing the injection port 2051. When the valve needle 4 moves upward, the injection port 2051 is opened, and the molten plastic can flow downward through the flow channel 11 to the discharge channel 21, and then the molten plastic enters the cavity of the mold body 3 through the injection port 2051 (it should be noted that the above-mentioned cavity is not drawn in the various figures).

[0022] During the installation of the hot nozzle, Figure 1 As shown, the upper end of the gate sleeve 2 is inserted into the installation cavity 12 from bottom to top, and then the gate sleeve 2 is rotated to make the external threaded portion 202 screwed into the internal threaded portion 122, so that the gate sleeve 2 spirally rises. When the inlet edge 2101 of the discharge channel contacts the lower edge 111 of the runner, the gate sleeve 2 is rotated slightly with force to make the inlet edge 2101 of the discharge channel press against the lower edge 111 of the runner, so that the material of the inlet edge 2101 of the discharge channel and the material of the lower edge 111 of the runner are slightly elastically deformed. That is to say, in theory, the inlet edge 2101 of the discharge channel and the lower edge 111 of the runner are It is a line contact, but due to the slight elastic deformation of the material of the discharge channel inlet edge 2101 and the material of the flow channel lower edge 111, the axial positioning step 1211 and the upper end face 200 of the sleeve are in a very small area of ​​surface contact (annular plane contact); the upper end face 200 of the sleeve and the axial positioning step 1211 will inevitably have flatness errors or surface processing defects. If the upper end face 200 of the sleeve and the axial positioning step 1211 are set in parallel contact, it is difficult to ensure that there is no gap between the discharge channel inlet edge 2101 and the flow channel lower edge 111, such as Figure 2 As shown, however, since the upper end face 200 of the sleeve of this embodiment forms an angle with the axial positioning step 1211, only the inlet edge 2101 of the discharge channel of the upper end face 200 contacts the lower edge 111 of the flow channel of the axial positioning step 1211, thereby ensuring that the inlet edge 2101 of the discharge channel is in close contact with the lower edge 111 of the flow channel, achieving an excellent sealing effect, preventing the molten plastic from penetrating between the inlet edge 2101 of the discharge channel and the lower edge 111 of the flow channel, and when the color needs to be changed, it is not necessary to spend a long time cleaning the joint between the inlet edge 2101 of the discharge channel and the lower edge 111 of the flow channel, which is conducive to rapid color change. By comparison Figure 1 and Figure 6 Since the sprue sleeve 2 of the utility model is formed with a material injection port 2051, it is unnecessary to set the nozzle core 5, which reduces the number of parts, is conducive to reducing the production cost, is conducive to improving the assembly efficiency, and eliminates the risk of the gap between the nozzle core 5 and the sprue sleeve 2 being infiltrated by the molten plastic. It is also relatively convenient to clean the hot nozzle. During the color change process, even if the sprue sleeve 2 is not disassembled, the color change operation can be completed by discharging the new color material less times, which is conducive to improving production efficiency and reducing production costs. Figure 1 and Figure 6In contrast, since the nozzle core 5 is removed in the utility model, the upper part of the discharge channel 21 can be linearly transitioned to the flow channel 11 while keeping the outer diameter of the lower end of the hot nozzle body 1 unchanged, which is conducive to the smooth flow of molten plastic. During this period, the discharge channel 21 and the injection port 2051 are circularly transitioned.

[0023] Furthermore, the upper end surface 200 of the sleeve is set as an upright conical surface, that is, the highest point of the upper end surface 200 of the sleeve is located at the entrance edge 2101 of the discharge channel, and the axial positioning step 1211 is set as a plane. Since the upper end surface 200 of the sleeve is an external structure, it can be easily manufactured by a lathe, and the axial positioning step 1211 is an internal structure, so the axial positioning step 1211 is set as a plane, which is easier to process and helps to reduce costs.

[0024] Furthermore, if Figure 2 As shown, the angle formed by the upper end surface 200 of the sleeve and the axial positioning step 1211 (i.e. Figure 2 The angle dimension "X" in the figure is set to 0.5° to 1°; if the angle dimension "X" is set too large, a weak sharp edge will be formed at the inlet edge 2101 of the discharge channel. When the gate sleeve 2 is assembled, the inlet edge 2101 of the discharge channel will be easily plastically deformed, and the inlet edge 2101 of the discharge channel may even bend inward. Therefore, it is preferred in this embodiment to set the angle dimension "X" to 0.5° to 1°.

[0025] Furthermore, if Figure 3 As shown, an upper positioning inner cylindrical surface 121 and a lower positioning inner cylindrical surface 123 are formed in the mounting cavity 12. The upper positioning inner cylindrical surface 121 is arranged between the axial positioning step 1211 and the upper end of the internal threaded portion 122, and the lower positioning inner cylindrical surface 123 is arranged at the lower side of the lower end of the internal threaded portion 122. Figure 4 As shown, the outer portion of the sleeve body 20 is formed with an upper journal 201 and a lower journal 203, and the external threaded portion 202 is disposed between the upper journal 201 and the lower journal 203. The outer diameter of the lower journal 203 is larger than the major diameter of the external threaded portion 202, and the minor diameter of the external threaded portion 202 is larger than the outer diameter of the upper journal 201. Figure 1 As shown, the upper journal 201 is adapted to be connected with the upper positioning inner cylindrical surface 121, and the lower journal 203 is adapted to be connected with the lower positioning inner cylindrical surface 123. Since the threaded connection does not have a radial high-precision positioning function, the upper positioning inner cylindrical surface 121 and the lower positioning inner cylindrical surface 123 are provided to radially position the upper and lower sides of the external threaded portion 202 respectively, thereby avoiding slight radial shaking of the gate sleeve 2 relative to the lower end of the hot nozzle body 1, which is beneficial to improving the stability of the injection molding production.

[0026] Furthermore, if Figure 4As shown, the outer portion of the sleeve body 20 is formed with a flange portion 204, and the flange portion 204 is formed with a slot 2041. The slot 2041 can be distributed at 180 degrees. Figure 1 As shown, the flange portion 204 is formed on the lower side of the lower journal 203. Figure 1 As shown, the flange portion 204 is located at the lower side of the lower end surface of the hot nozzle body 1. Since the lower opening edge 111 of the flow channel is aligned and connected with the inlet edge 2101 of the discharge channel, the flange portion 204 and the lower end surface of the hot nozzle body 1 are not in contact. By setting the slot 2041, the worker can insert the convex teeth of the round nut wrench (crescent wrench) into the slot 2041, and then swing the round nut wrench to easily rotate the gate sleeve 2 to install and remove the gate sleeve 2.

[0027] Furthermore, if Figure 4 As shown, the upper end of the upper journal 201 is formed with a guide cone 2011, the upper end diameter of the guide cone 2011 is smaller than the lower end diameter of the guide cone 2011, and the guide cone 2011 can be understood as an unequal chamfer. Figure 1 As shown, during the process of assembling the gate sleeve 2, the gate sleeve 2 is spirally moved upward so that the upper end of the sleeve body 20 enters the upper positioning inner cylindrical surface 121. That is to say, the upper end of the sleeve body 20 is not conveniently moved radially to be adjusted to align with the upper positioning inner cylindrical surface 121. The provision of a guide cone 2011 to guide the upper shaft neck 201 to insert into the upper positioning inner cylindrical surface 121 is conducive to facilitating the assembly of the gate sleeve 2.

Claims

1. A needle valve type hot nozzle convenient color changing structure, comprising a hot nozzle body (1), a flow channel (11) formed in the hot nozzle body (1), a mounting cavity (12) formed in the lower end of the hot nozzle body (1), the lower end of the flow channel (11) communicating with the upper end of the mounting cavity (12), characterized in that: The invention also comprises a gate sleeve (2) and a valve needle (4), wherein the gate sleeve (2) comprises a sleeve body (20), wherein a discharge channel (21) is formed in the sleeve body (20), wherein the upper part of the valve needle (4) is located in the flow channel (11), and the lower part of the valve needle (4) is located in the discharge channel (21), wherein an upper end surface (200) of the sleeve body is formed at the upper end of the sleeve body (20), and a discharge channel inlet edge (2101) is formed at the connection between the upper end surface (200) of the sleeve body and the upper end of the discharge channel (21), wherein an external threaded portion (202) is formed on the sleeve body (20), and an axial positioning step (1211) is formed between the upper end of the mounting cavity (12) and the lower end of the flow channel (11), and a The lower opening edge (111) of the flow channel, the mounting cavity (12) is formed with an internal threaded portion (122), the internal threaded portion (122) is threadedly connected with the external threaded portion (202), the upper end surface (200) of the sleeve body is arranged corresponding to the axial positioning step (1211), the upper end surface (200) of the sleeve body and the axial positioning step (1211) form an angle, the lower opening edge (111) of the flow channel is aligned and abutted with the inlet edge (2101) of the discharge channel, the lower end of the sleeve body (20) is formed with a positioning nozzle end (205) for matching the gate (311) of the mold body (3), the lower end of the discharge channel (21) is formed with an injection port (2051) matching the lower end of the valve needle (4), and the injection port (2051) is located within the positioning nozzle end (205).

2. According to claim 1, the needle valve type hot nozzle convenient color change structure is characterized by: The upper end surface (200) of the sleeve is set as a right-positioned conical surface, and the axial positioning step (1211) is set as a plane.

3. According to claim 2, the needle valve type hot nozzle convenient color change structure is characterized by: The included angle formed by the upper end surface (200) of the sleeve and the axial positioning step (1211) is set to 0.5° to 1°.

4. According to claim 1, the needle valve type hot nozzle convenient color change structure is characterized by: An upper positioning inner cylindrical surface (121) and a lower positioning inner cylindrical surface (123) are formed in the installation cavity (12); the upper positioning inner cylindrical surface (121) is arranged between the axial positioning step (1211) and the upper end of the internal threaded portion (122); the lower positioning inner cylindrical surface (123) is arranged on the lower side of the lower end of the internal threaded portion (122); an upper shaft neck (201) and a lower shaft neck (203) are formed on the outside of the sleeve body (20); The external threaded portion (202) is arranged between the upper journal (201) and the lower journal (203); the outer diameter of the lower journal (203) is larger than the major diameter of the external threaded portion (202); the minor diameter of the external threaded portion (202) is larger than the outer diameter of the upper journal (201); the upper journal (201) is adaptively connected to the upper positioning inner cylindrical surface (121); and the lower journal (203) is adaptively connected to the lower positioning inner cylindrical surface (123).

5. According to claim 4, the needle valve type hot nozzle convenient color change structure is characterized by: A flange portion (204) is formed on the outside of the sleeve body (20), a groove (2041) is formed on the flange portion (204), the flange portion (204) is formed on the lower side of the lower shaft neck (203), and the flange portion (204) is located on the lower side of the lower end surface of the hot nozzle body (1).

6. The needle valve type hot nozzle convenient color changing structure according to claim 4, characterized in that: A guide cone portion (2011) is formed at the upper end of the upper journal (201).

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