Sprue bush

Abstract

The utility model discloses a sprue bush, which is characterized in that only one inlet section and only one outlet section are respectively arranged at two ends of a cooling flow channel, so that the flow of cooling fluid can be monitored in real time only through the single inlet section and the single outlet section, and the accuracy of cooling uniform temperature can be accurately controlled. And the cooling runner is used for cooling and equalizing the temperature of the main runner, so that the cooling efficiency is better, the cooling time is shortened, the overall forming period is further shortened, the forming yield of the optical element is improved, the size of the sprue bush can be maintained to be fine and tiny, and the structural strength and the machining feasibility of the sprue bush are ensured.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and in particular to a sprue sleeve, which can be applied to optical component molding molds. Background Technology

[0002] In the field of injection molding, due to the small size of the sprue bushing and the fact that the sprue bushing generally does not have a cooling channel for the main runner, the mold cooling time cannot be shortened, resulting in a longer overall molding cycle. In addition, the material temperature distribution in the main runner is also significantly different, which affects the molding yield.

[0003] In addition, when setting up cooling water channels on the sprue bushing to cool the main flow channel, the compatibility between the main flow channel and the cooling flow channel must be considered to ensure that the size of the sprue bushing is not too large, while also having sufficient structural strength and manufacturability.

[0004] Therefore, the problem that must be solved is how to achieve uniform temperature in both the long axis and transverse cross-section of the main runner while cooling it to improve molding yield, and how to maintain the fine and small size of the sprue bushing, structural strength and processing feasibility. Utility Model Content

[0005] To address the aforementioned problems, this invention provides a sprue sleeve that achieves uniform temperature through cooling the main runner, maintains the sprue sleeve's precise and small dimensions, and simultaneously ensures its structural strength and processing feasibility.

[0006] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0007] This utility model provides a sprue bushing, including a main channel extending along its long axis and a cooling channel surrounding the main channel. The cooling channel includes an inlet section for introducing cooling fluid, an outlet section for discharging cooling fluid, and a channel unit connecting the inlet section and the outlet section. The channel unit includes an inner channel for introducing cooling fluid from the inlet section, an outer channel for discharging cooling fluid to the outlet section, and a connecting portion connecting the inner channel and the outer channel. The inner channel is located between the outer channel and the main channel, and forms a cylindrical structure surrounding the main channel along its long axis. It includes a first inner wall close to the main channel, a first outer wall away from the main channel, and a first top surface connecting the first inner wall and the first outer wall. The outer channel forms a cylindrical structure surrounding the inner channel along its long axis, and includes a second inner wall close to the inner channel, a second outer wall away from the inner channel, and a second top surface connecting the second inner wall and the second outer wall.

[0008] This utility model also provides a sprue bushing, including a main channel extending along the long axis and a cooling channel surrounding the main channel. The cooling channel includes only one inlet section for introducing cooling fluid, only one outlet section for discharging cooling fluid, and a channel unit connecting the inlet section and the outlet section. The channel unit includes an inner channel for introducing cooling fluid from the inlet section, an outer channel for discharging cooling fluid to the outlet section, and a connecting portion connecting the inner channel and the outer channel. The inner channel forms a cylindrical structure and surrounds the main channel along the long axis, and includes a first inner wall close to the main channel, a first outer wall away from the main channel, and a first top surface connecting the first inner wall and the first outer wall, and satisfies 0.4≤DImin / BRmax≤6.0.

[0009] In one embodiment of the present invention, there is a minimum transverse cross section between the first outer wall and the second inner wall, and the distance between the first outer wall and the second inner wall in the direction of the minimum transverse cross section is 1.2 to 3.0 mm.

[0010] In one embodiment of this utility model, the distance between the main channel and the first inner wall in the direction of their minimum transverse cross section is 1.2 to 3.0 mm.

[0011] In one embodiment of the present invention, there is a minimum transverse cross section between the first outer wall and the outer flow channel, and the distance between the first outer wall and the outer flow channel in the direction of the minimum transverse cross section is 1.2 to 3.0 mm.

[0012] In one embodiment of this utility model, a sprue is provided at one end of the main channel along the long axis, and the inlet section, outlet section and sprue are all located on the same side of the sprue sleeve.

[0013] In one embodiment of this utility model, the number of the above-mentioned connecting parts is at least two.

[0014] In one embodiment of the present invention, the connecting portion includes an inlet disposed on the first outer wall for communicating with the inner flow channel, an outlet for communicating with the outer flow channel, and a connecting section connecting the inlet and the outlet.

[0015] In the above-mentioned gating sleeve, the embodiments may further selectively satisfy any of the following conditions:

[0016] 0.2 ≤ DImin / DOmax ≤ 1.0;

[0017] 2.0 ≤ DOmax / BRmax ≤ 13.0;

[0018] 0.2≤DImin / DOmaxB≤0.4;

[0019] 1.0≤Wi / Wo≤1.5;

[0020] 0.2≤LR / LI≤10.0.

[0021] Wherein, DImin is the minimum distance of the first inner wall corresponding to the maximum diameter of the main channel, BRmax is the maximum diameter of the main channel, DOmax is the maximum distance of the second outer wall in the transverse cross-sectional direction, DOmaxB is the maximum distance of the outer channel in the transverse cross-sectional direction, Wi is the minimum width of the transverse cross-section through which the cooling fluid can flow in the inner channel, Wo is the minimum width of the transverse cross-section through which the cooling fluid can flow in the outer channel, LR is the maximum length of the main channel along the long axis starting from the injection port, and LI is the maximum length of the first inner wall along the long axis.

[0022] This invention ensures that the temperature of the plastic melt in the main channel is uniformly distributed in its long axis and transverse cross-sectional direction by surrounding the cooling channel with the cooling fluid introduced from the inlet section, and then discharged from the outlet section after passing through the inner channel and outer channel in sequence. It can be used to install on the injection molding mold of optical components.

[0023] The cooling channel of this invention has only one inlet section and one outlet section at each end. Therefore, the flow rate of the cooling fluid can be monitored by using only a single inlet section and a single outlet section. This makes it easier to grasp the real-time flow rate of the cooling fluid. For example, when the temperature of the main channel is too high, the flow rate of the cooling fluid can be increased. It can also achieve more accurate control in terms of cooling temperature uniformity.

[0024] Therefore, the present invention, with its sprue bushing having a cooling and temperature equalization function, can achieve better cooling efficiency, thereby reducing cooling time and shortening the overall molding cycle. At the same time, it can improve the molding yield of optical components, maintain the fine and small size of the sprue bushing, and ensure its structural strength and processing feasibility. Attached Figure Description

[0025] Figure 1 The image shown is a top view of the sprue bushing in Embodiment 1;

[0026] Figure 2 As shown Figure 1 Sectional view of AA;

[0027] Figure 3 As shown Figure 1 Sectional view of BB;

[0028] Figure 4 The diagram shown is a structural diagram of the sprue sleeve in Embodiment 1;

[0029] Figure 5 The image shown is a top view of the sprue bushing in Embodiment 2;

[0030] Figure 6As shown Figure 5 Sectional view of CC;

[0031] Figure 7 As shown Figure 5 Sectional view of DD;

[0032] Figure 8 The diagram shown is a structural diagram of the gating sleeve in Example 2. Detailed Implementation

[0033] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0034] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] Reference Figures 1 to 4 Example 1 provides a sprue sleeve for mounting on an injection molding die for optical components.

[0037] like Figure 2 and Figure 4 As shown, the sprue bushing of this embodiment includes a main channel 1 extending along the long axis direction I and a cooling channel 2 surrounding the main channel 1. The upper end of the main channel 1 along its long axis direction I and away from the mold core of the injection mold is provided with a sprue port 11 for injecting liquid plastic melt. The lower end of the main channel 1 is used to connect to the branch channel of the injection mold.

[0038] The cooling channel 2 includes only one inlet section 21 for introducing cooling fluid, only one outlet section 22 for discharging cooling fluid, and a channel unit connecting the inlet section 21 and the outlet section 22. At this time, the inlet section 21, the outlet section 22 and the injection port 11 are all located on the same side of the sprue sleeve. This is beneficial for designing the channel unit 23, while also keeping the size of the sprue sleeve within a small range.

[0039] like Figure 2 As shown, the flow channel unit includes an inner flow channel 23 for introducing cooling fluid from the inlet section 21, an outer flow channel 24 for discharging cooling fluid to the outlet section 22, and four connecting portions 25 connecting the inner flow channel 23 and the outer flow channel 24. The inner flow channel 23 is located between the outer flow channel 24 and the main flow channel 1. Of course, in other embodiments, the number of connecting portions 25 may be two, three, or five or more, and is not limited to this.

[0040] In this embodiment, the inner flow channel 23 and the outer flow channel 24 are respectively formed into cylindrical structures and are respectively surrounded along the long axis direction I of the main flow channel 1. At this time, the inner flow channel 23 surrounds the main flow channel 1 and the outer flow channel 24 surrounds the inner flow channel 23.

[0041] like Figure 2 and Figure 3 As shown, the inner flow channel 23 includes a first inner wall 231 close to the main flow channel 1, a first outer wall 232 away from the main flow channel 1, and a first top surface 233 connecting the first inner wall 231 and the first outer wall 232. The first top surface 233 is provided with a first connection port for connecting the inlet section 21 to ensure that the inner flow channel 23 and the inlet section 21 are connected.

[0042] like Figure 2 and Figure 3 As shown, the outer flow channel 24 includes a second inner wall 241 close to the inner flow channel 23, a second outer wall 242 away from the inner flow channel 23, and a second top surface 243 connecting the second inner wall 241 and the second outer wall 242. The second top surface 243 is provided with a second connection port for connecting the outlet section 22 to ensure that the outer flow channel 24 and the outlet section 22 are connected.

[0043] Also, such as Figure 2 As shown, each connecting part 25 includes an inlet provided on the first outer wall 232 for connecting the inner flow channel 23, an outlet for connecting the outer flow channel 24, and a connecting section between the inlet and the outlet. Therefore, the bottom of the inner flow channel 23 away from the first top surface 233 and the bottom of the outer flow channel 24 away from the second top surface 243 are connected by the corresponding connecting part 25 to ensure that the cooling fluid flows from the inner flow channel 23 to the outer flow channel 24, while enhancing the cooling efficiency of the main flow channel 1.

[0044] When the cooling flow is introduced from the inlet section 21, and then passes through the inner flow channel 23 and the outer flow channel 24 in sequence, the cooling fluid is discharged from the outlet section 22, thus ensuring that the temperature of the plastic melt in the main flow channel 1 is uniformly distributed in its long axis direction I and transverse cross-sectional direction.

[0045] When the main runner 1, inner runner 23, and outer runner 24 are arranged sequentially from the inside to the outside, the temperature difference between the inner runner 23 and the main runner 1 is relatively large, which can accelerate the cooling effect of the inner runner 23 on the main runner 1. Moreover, the temperature distribution decreases sequentially from the highest temperature of the main runner 1, the inner runner 23, and the outer runner 24. The temperature of the outer runner 24 is lower than that of the inner runner 23, which can accelerate the heat dissipation of the inner runner 23. The temperature of the inner runner 23 is lower than that of the main runner 1, which can also improve the uniform cooling effect of the plastic melt in the main runner 1 in its transverse cross section and long axis direction I, thereby ensuring a better injection molding yield.

[0046] When the first inner wall 231 of the inner channel 23 surrounds and wraps around the main channel 1, the main channel 1 can be cooled to the maximum extent to achieve the best cooling and temperature uniformity effect and improve the injection molding yield.

[0047] When the outer flow channel 24 surrounds and encloses the inner flow channel 23, it can save the volume of the entire flow channel unit, and can also ensure the heat dissipation effect of the outer flow channel 24 while reducing the size of the sprue sleeve.

[0048] In summary, this embodiment ensures that the temperature of the plastic melt in the main channel 1 is uniformly distributed in its long axis direction I and transverse cross-sectional direction by having the cooling channel 2 surround the main channel 1, introducing the cooling fluid from the inlet section 21, and then sequentially passing through the inner channel 23 and the outer channel 24 before exiting from the outlet section 22. This allows it to be used for installation on injection molding molds for optical components.

[0049] In this embodiment, the cooling channel 2 is provided with only one inlet section 21 and only one outlet section 22 at each end. Therefore, the flow rate of the cooling fluid can be monitored by only a single inlet section 21 and a single outlet section 22. This makes it easier to grasp the real-time flow rate of the cooling fluid. For example, when the temperature in the main channel 1 is too high, the flow rate of the cooling fluid can be increased. It can also achieve more accurate control in terms of cooling temperature uniformity.

[0050] Therefore, this embodiment uses a sprue bushing with a cooling and temperature equalization function, which can achieve better cooling efficiency, reduce cooling time, shorten the overall molding cycle, improve the molding yield of optical components, maintain the fine and small size of the sprue bushing, and ensure its structural strength and processing feasibility.

[0051] In another preferred embodiment, such as Figure 3 As shown, the sprue sleeve in this embodiment further satisfies 0.2≤DImin / DOmax≤1.0, where DImin is the minimum distance of the first inner wall 231 corresponding to the maximum diameter of the main channel 1, and DOmax is the maximum distance of the second outer wall 242 in the transverse cross-sectional direction.

[0052] When the inner flow channel 23 is close to the main flow channel 1, the cooling efficiency of the cooling flow channel 2 is better; at the same time, when the distance between the outer flow channel 24 and the inner flow channel 23 is kept within an appropriate range, the heat dissipation effect of the cooling flow channel 2 is better. Therefore, the two need to be matched to achieve the best ratio range.

[0053] Further preferred, such as Figure 3As shown, the sprue bushing in this embodiment satisfies 2.0≤DOmax / BRmax≤13.0, where DOmax is the maximum distance of the second outer wall 242 in the transverse cross-sectional direction, and BRmax is the maximum diameter of the main channel 1. This can effectively reduce the temperature of the plastic melt in the main channel 1, so that the temperature of the main channel 1 drops uniformly in the transverse cross-sectional direction, and the size of the sprue bushing will not be too large.

[0054] Further preferred, such as Figure 3 As shown, the sprue bushing in this embodiment satisfies 1.0≤Wi / Wo≤1.5, where Wi is the minimum width of the transverse cross section through which the cooling fluid can flow in the inner channel 23, and Wo is the minimum width of the transverse cross section through which the cooling fluid can flow in the outer channel 24. This can effectively adjust the volume and flow rate of the cooling fluid in the inner channel 23.

[0055] When the volume of the cooling fluid in the inner channel 23 is large, it can more easily absorb the heat of the main channel 1. At the same time, the minimum width of the outer channel 24 in the transverse cross-section direction can be used to adjust the flow rate of the cooling fluid in the inner channel 23, thereby ensuring uniform cooling temperature and increasing the cooling efficiency of the main channel 1.

[0056] Further preferred, such as Figure 3 As shown, the sprue sleeve in this embodiment satisfies 0.2≤LR / LI≤10.0, where LR is the maximum length of the main channel 1 from the injection port along the long axis direction I, and LI is the maximum length of the first inner wall 231 along the long axis direction I. This is beneficial for better setting the inner flow channel 23 around the main channel 1, so as to improve the cooling uniformity of the main channel 1 in its long axis direction I, maintain the structural strength of the sprue sleeve, and take into account its processing feasibility.

[0057] Of course, in other embodiments, the preferred ratio of DOmax / BRmax is 4.0 to 6.0; the preferred ratio of Wi / Wo is 1.0 to 1.3; and the preferred ratio of LR / LI is 0.2 to 2.0.

[0058] Further preferred, such as Figure 3 As shown, there is a minimum transverse section between the first outer wall 232 and the second inner wall 241, and the distance between the first outer wall 232 and the second inner wall 241 in the direction of the minimum transverse section is 1.2 to 3.0 mm.

[0059] When the distance between the first outer wall 232 and the second inner wall 241 in the transverse cross-sectional direction is maintained within an appropriate range, the sprue bushing can maintain its fine and small size while cooling and dissipating the main channel 1, and its structural strength and processing feasibility can also be guaranteed.

[0060] Further preferred, such as Figure 3As shown, there is a minimum transverse section between the main channel 1 and the first inner wall 231, and the distance between the main channel 1 and the first inner wall 231 in the direction of its minimum transverse section is 1.2 to 3.0 mm.

[0061] When the distance between the main flow channel 1 and the first inner wall 231 in the transverse cross-sectional direction is maintained within an appropriate range, the inner flow channel 23 can maintain the fine and small size of the sprue sleeve while cooling the main flow channel 1, and can also ensure its structural strength and processing feasibility.

[0062] Further preferred, such as Figure 2 and Figure 3 As shown, there is a minimum transverse cross section between the first outer wall 232 and the outer flow channel 24, and the distance between the first outer wall 232 and the outer flow channel 24 in the direction of its minimum transverse cross section is 1.2 to 3.0 mm.

[0063] When the distance between the outer channel 24 and the first outer wall 232 in the transverse cross-section direction is maintained within an appropriate range, the sprue bushing can be kept small and precise in size while cooling and dissipating the main channel 1, and its structural strength and processing feasibility can also be guaranteed.

[0064] Please refer to Table 1 for the relevant parameters of the sprue bushing in this specific embodiment. The sprue bushing has a cooling and temperature equalization function, which can achieve better cooling efficiency, reduce cooling time, and shorten the overall molding cycle. At the same time, it can improve the molding yield of optical components, maintain the fine and small size of the sprue bushing, and ensure its structural strength and processing feasibility.

[0065] Table 1:

[0066] parameter Example 1 DImin 4.000mm DOmax 10.000mm BRmax 1.896mm Wi 1.000mm Wo 1.000mm LR 17.521mm LI 15.038mm DImin / DOmax 0.4 DImin / BRmax 2.1 DOmax / BRmax 5.3 Wi / Wo 1.0 LR / LI 1.2

[0067] Of course, in other embodiments, DImin can also be selected in the range of 3.8 to 10.0 mm, and it is preferably 3.8 to 5.0 mm; DOmax can also be selected in the range of 9.0 to 24.0 mm, and it is preferably 9.0 to 16.0 mm; BRmax can also be selected in the range of 1.8 to 10.0 mm, and it is preferably 1.8 to 6.0 mm; Wi can also be selected in the range of 0.8 to 2.0 mm, and it is preferably 1.0 to 1.3 mm; Wo can also be selected in the range of 0.8 to 2.0 mm, and it is preferably 1.0 to 1.3 mm; LR can also be selected in the range of 14.0 to 80.0 mm, and it is preferably 16.0 to 18.0 mm; LI can also be selected in the range of 8.0 to 75.0 mm, and it is preferably 13.0 to 16.0 mm.

[0068] Example 2

[0069] Reference Figures 5 to 8Embodiment 2 provides a sprue sleeve. The structure of Embodiment 2 is largely the same as that of Embodiment 1, except that the outer flow channel 24' is a hollow frustum structure, and the second inner wall 241' and the second outer wall 242' of the outer flow channel 24' are respectively inclined outward. Of course, in other embodiments, the external structure of the outer flow channel 24' is not limited to this, and a polygonal prism structure can also be adopted.

[0070] The inner flow channel 23 surrounds the main flow channel 1 along its long axis I. When the cooling flow is introduced from the inlet section 21, and then passes through the inner flow channel 23 and the outer flow channel 24' in sequence, the cooling fluid is discharged from the outlet section 22. This ensures that the temperature of the plastic melt in the main flow channel 1 is uniformly distributed in its long axis I and transverse cross-sectional direction.

[0071] When the main runner 1, inner runner 23, and outer runner 24' are sequentially arranged from the center of the sprue bushing in a radial direction (i.e., in the transverse cross-sectional direction) away from the center of the sprue bushing, the temperature difference between the inner runner 23 and the main runner 1 is relatively large, which can accelerate the cooling effect of the inner runner 23 on the main runner 1. Moreover, the temperature distribution decreases sequentially from the highest temperature of the main runner 1, the inner runner 23, and the outer runner 24'. At this time, the temperature of each runner decreases uniformly in the direction away from the center of the sprue bushing. This can improve the uniform cooling effect of the plastic melt temperature in the main runner 1 in its long axis direction I and transverse cross-sectional direction, thereby ensuring a better injection molding yield.

[0072] The inner runner 23 is provided with an outer runner 24' in the radial direction away from the center of the sprue bushing, which can ensure that the radial dimension of the entire sprue bushing is not too large, thereby reducing the overall volume of the injection mold.

[0073] When the first inner wall 231 of the inner channel 23 surrounds and wraps around the main channel 1, the main channel 1 can be cooled to the maximum extent to achieve the best cooling and temperature uniformity effect and improve the injection molding yield.

[0074] like Figure 7 As shown, when the sprue sleeve of this embodiment satisfies 0.4≤DImin / BRmax≤6.0, and in conjunction with the maximum diameter of the main channel 1 and the minimum distance of the first inner wall 231 corresponding to the maximum diameter of the main channel 1, it can ensure that the temperature of the plastic melt in the main channel 1 is uniformly distributed in the transverse cross-sectional direction, and can also achieve better cooling efficiency to shorten the cooling time. At the same time, the sprue sleeve of this embodiment still has sufficient structural strength under the premise of its small size.

[0075] Of course, in other embodiments, the preferred ratio of DImin / BRmax is 1.0 to 3.0.

[0076] Further preferred, such as Figure 7As shown, the sprue sleeve in this embodiment satisfies 0.2≤DImin / DOmaxB≤0.4, where DOmaxB is the maximum distance of the outer flow channel 24' in the transverse cross-sectional direction.

[0077] like Figure 6 and Figure 8 As shown, when the inner channel 23 is close to the main channel 1, the cooling efficiency of the cooling channel 2 is better; at the same time, when the distance between the outer channel 24' and the inner channel 23 is kept within an appropriate range, the heat dissipation effect of the cooling channel 2 is better. Therefore, the two need to be matched to achieve the best ratio range.

[0078] Please refer to Table 2 for the relevant parameters of the sprue bushing in this specific embodiment. The sprue bushing has a cooling and temperature equalization function, which can achieve better cooling efficiency, reduce cooling time, and shorten the overall molding cycle. At the same time, it can improve the molding yield of optical components, maintain the fine and small size of the sprue bushing, and ensure its structural strength and processing feasibility.

[0079] Table 2:

[0080]

[0081]

[0082] Of course, in other embodiments, DOmaxB can also be selected in the range of 9.0 to 24.0 mm, and it is preferably 9.0 to 18.5 mm.

[0083] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A gate sleeve, characterized in that: It includes a main channel extending along a long axis and a cooling channel surrounding the main channel. The cooling channel includes only one inlet section for introducing a cooling fluid, only one outlet section for discharging the cooling fluid, and a channel unit connecting the inlet section and the outlet section; The flow channel unit includes an inner flow channel for introducing the cooling fluid from the inlet section, an outer flow channel for discharging the cooling fluid to the outlet section, and a connecting portion connecting the inner flow channel and the outer flow channel, wherein the inner flow channel is located between the outer flow channel and the main flow channel. The internal flow channel forms a cylindrical structure and surrounds the main flow channel along its long axis, and includes a first inner wall close to the main flow channel, a first outer wall away from the main flow channel, and a first top surface connecting the first inner wall and the first outer wall. The outer flow channel forms a cylindrical structure and surrounds the inner flow channel along its long axis, and includes a second inner wall close to the inner flow channel, a second outer wall away from the inner flow channel, and a second top surface connecting the second inner wall and the second outer wall.

2. The gate sleeve according to claim 1, characterized in that: Furthermore, it satisfies 0.2≤DImin / DOmax≤1.0, where DImin is the minimum distance of the first inner wall corresponding to the maximum diameter of the main channel, and DOmax is the maximum distance of the second outer wall in the transverse cross-sectional direction.

3. The gate sleeve according to claim 1, characterized in that: There is a minimum transverse section between the first outer wall and the second inner wall, and the distance between the first outer wall and the second inner wall in the direction of the minimum transverse section is 1.2 to 3.0 mm.

4. The gate sleeve according to claim 1, characterized in that: Furthermore, it satisfies 2.0≤DOmax / BRmax≤13.0, where DOmax is the maximum distance of the second outer wall in the transverse cross-sectional direction, and BRmax is the maximum diameter of the main channel.

5. A gate sleeve, characterized in that: It includes a main channel extending along a long axis and a cooling channel surrounding the main channel. The cooling channel includes only one inlet section for introducing a cooling fluid, only one outlet section for discharging the cooling fluid, and a channel unit connecting the inlet section and the outlet section; The flow channel unit includes an inner flow channel for introducing the cooling fluid from the inlet section, an outer flow channel for discharging the cooling fluid to the outlet section, and a connecting portion connecting the inner flow channel and the outer flow channel. The internal flow channel forms a cylindrical structure and surrounds the main flow channel along its long axis, and includes a first inner wall close to the main flow channel, a first outer wall away from the main flow channel, and a first top surface connecting the first inner wall and the first outer wall. And satisfy 0.4≤DImin / BRmax≤6.0, where DImin is the minimum distance of the first inner wall corresponding to the maximum diameter of the main channel, and BRmax is the maximum diameter of the main channel.

6. The sprue sleeve according to claim 5, characterized in that: Furthermore, it satisfies 0.2≤DImin / DOmaxB≤0.4, where DOmaxB is the maximum distance of the external flow channel in the transverse cross-sectional direction.

7. The gate sleeve according to claim 1 or 5, characterized in that: There is a minimum transverse cross section between the main channel and the first inner wall, and the distance between the main channel and the first inner wall in the direction of the minimum transverse cross section is 1.2 to 3.0 mm.

8. The gate sleeve according to claim 1 or 5, characterized in that: There is a minimum transverse cross section between the first outer wall and the outer flow channel, and the distance between the first outer wall and the outer flow channel in the direction of the minimum transverse cross section is 1.2 to 3.0 mm.

9. The gate sleeve according to claim 1 or 5, characterized in that: A sprue is provided at one end of the main channel along the long axis, and the inlet section, the outlet section and the sprue are all located on the same side of the sprue sleeve.

10. The gate sleeve according to claim 1 or 5, characterized in that: Furthermore, it satisfies 1.0≤Wi / Wo≤1.5, where Wi is the minimum width of the transverse cross-section through which the cooling fluid can flow in the inner channel; and Wo is the minimum width of the transverse cross-section through which the cooling fluid can flow in the outer channel.

11. The gate sleeve according to claim 1 or 5, characterized in that: The main channel is provided with a sprue at one end along the long axis, and the sprue sleeve satisfies 0.2≤LR / LI≤10.0, where LR is the maximum length of the main channel from the sprue along the long axis, and LI is the maximum length of the first inner wall along the long axis.

12. The gate sleeve according to claim 1 or 5, characterized in that: The number of such connecting parts is at least two.

13. The gate sleeve according to claim 1 or 5, characterized in that: The connecting part includes an inlet disposed on the first outer wall for communicating with the inner flow channel, an outlet for communicating with the outer flow channel, and a connecting section connecting the inlet and the outlet.

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