Valve needle, hot runner system and injection mold

Abstract

The utility model belongs to the technical field of injection molds, and discloses a valve needle, a hot runner system and an injection mold, the valve needle comprises an outer valve needle and an inner valve needle, the lower end of the outer valve needle is provided with a first discharge port, and the inner valve needle is slidably arranged in the outer valve needle along the vertical direction to close or open the first discharge port; the outer valve needle comprises a discharging part, a first material sealing part and a first material conveying part which are sequentially communicated from top to bottom, a discharging gap is formed between the upper portion of the inner valve needle and the discharging part, the upper portion of the inner valve needle can be in sealing fit with the first material sealing part, a first material supply runner is formed between the lower portion of the inner valve needle and the outer valve needle, and a feeding hole is formed in the first material conveying part; the first feeding runner is communicated with the feeding hole; a discharging groove is formed in the inner wall of the discharging part in the circumferential direction of the discharging part, a through discharging hole is formed in the side, away from the discharging gap, of the discharging groove and communicates with the discharging gap through the discharging groove, and in the relative movement process of the inner valve needle and the outer valve needle, waste is gathered into the discharging groove and automatically discharged through the discharging hole.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to a valve needle, a hot runner system and an injection mold. Background Art

[0002] Existing hot runner systems suitable for two-shot injection molding are filled with molten plastic during injection. The plastic enters the mold cavity through the injection nozzle, the manifold, the main body, and the hot nozzle outlet. A valve pin is located within the main body and surrounded by molten plastic. A timing controller controls the opening and closing of the inner and outer valve pins to control the flow of plastic from the hot nozzle outlet.

[0003] During injection molding, the valve needle is in motion and waste will be generated at the sealing position of the valve needle. If the waste is not removed, it will easily hinder the movement of the valve needle in long-term injection molding production, and affect the appearance of the product, causing black lines and black spots, affecting product quality. Therefore, the valve needle often needs to be cleaned and repaired, resulting in low production efficiency.

[0004] Therefore, it is urgent to provide a valve needle, a hot runner system and an injection mold to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a valve needle, a hot runner system and an injection mold, which can automatically discharge waste, improve product quality, reduce the frequency of cleaning and repairing the valve needle, and improve production efficiency.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] A valve needle, comprising an outer valve needle and an inner valve needle, wherein the outer valve needle is hollow and has a first discharge port at its lower end, and the inner valve needle is vertically slidably disposed within the outer valve needle to have a first sealing position for closing the first discharge port and a first feeding position for opening the first discharge port;

[0008] The outer valve needle includes a discharge portion, a first sealing portion, and a first material feeding portion that are sequentially connected from top to bottom. A discharge gap is formed between the upper portion of the inner valve needle and the discharge portion, and the upper portion of the inner valve needle can be sealed with the first material sealing portion. A first material supply channel is formed between the lower portion of the inner valve needle and the outer valve needle. A material feed hole is formed on the first material feeding portion, and the first material supply channel is connected to the material feed hole.

[0009] When the inner valve needle is located at the first sealing position, the lower end of the inner valve needle blocks the first discharge port to close the outlet of the first material supply channel; when the inner valve needle is located at the first material supply position, the first material supply channel is connected to the first discharge port to open the outlet of the first material supply channel;

[0010] A discharge groove is formed on the inner wall of the discharge portion along its circumference, and a through discharge hole is formed on a side of the discharge groove away from the discharge gap. The discharge hole is connected to the discharge gap through the discharge groove.

[0011] Furthermore, at least two discharge holes are formed at the bottom of the discharge groove, and the at least two discharge holes are evenly spaced apart along the circumference of the outer valve needle.

[0012] Furthermore, the width of the discharge groove gradually decreases in a direction away from the inner valve needle.

[0013] Furthermore, n+5 mm≤m≤n+10 mm, wherein m is the length of the first sealing portion, and n is the movement stroke of the inner valve needle.

[0014] Furthermore, 20 mm ≤ s ≤ 55 mm, wherein an outer needle hanging platform is further provided at the upper end of the discharge portion, and s is the distance between the axis of the discharge hole and the bottom of the outer needle hanging platform.

[0015] Furthermore, when the inner valve needle is located at the first sealing position, the top of the first material supply channel is located at the top of the material feed hole.

[0016] A hot runner system comprises a main body and the valve needle as described above, wherein a second discharge port is formed at the lower end of the main body, and an outer valve needle is vertically slidably disposed within the main body to have a second sealing position for closing the second discharge port and a second supply position for opening the second discharge port;

[0017] The main body includes a second sealing portion, a second material feeding portion, a third sealing portion and a third material feeding portion that are sequentially connected from top to bottom, the outer valve needle is in sealing cooperation with the second sealing portion and the third sealing portion, a material storage bag is formed between the outer valve needle and the second material feeding portion, the main body is further provided with a first material feed port and a second material feed port, the material feed hole is connected with the first material feed port through the material storage bag, a second material supply channel is formed between the outer valve needle and the third material feeding portion, and the second material supply channel is connected with the second material feed port;

[0018] When the outer valve needle is located at the second sealing position, the lower end of the outer valve needle blocks the second discharge port to close the outlet of the second supply channel; when the outer valve needle is located at the second supply position, the second supply channel is connected to the second discharge port to open the outlet of the second supply channel.

[0019] Furthermore, the first feeding portion is provided with at least two feeding holes; and / or,

[0020] When the outer valve needle is located at the second material sealing position, the bottom of the feed hole is located at the bottom of the material storage bag.

[0021] Furthermore, x=y+z, wherein x is the height of the storage bag, y is the movement stroke of the outer valve needle, and z is the diameter of the feed hole.

[0022] An injection mold comprises a mold body and the hot runner system as described above. A cavity is defined in the mold body, and the first discharge port and the second discharge port are both connected to the cavity.

[0023] Beneficial effects of the utility model:

[0024] The utility model provides a valve needle, a hot runner system and an injection mold, the valve needle comprises an outer valve needle and an inner valve needle, the outer valve needle is hollow, the lower end of the outer valve needle is provided with a first outlet port, and the inner valve needle is slidably arranged in the outer valve needle along the vertical direction, so as to have a first sealing position that closes the first outlet port and a first feeding position that opens the first outlet port; the outer valve needle comprises a discharge part, a first sealing part and a first feeding part that are sequentially connected from top to bottom, a discharge gap is formed between the upper part of the inner valve needle and the discharge part, and the upper part of the inner valve needle can be sealed with the first sealing part, a first feeding channel is formed between the lower part of the inner valve needle and the outer valve needle, a feeding hole is provided on the first feeding part, and the first feeding channel is connected with the feeding hole; when the inner valve needle is in the first sealing position, the lower end of the inner valve needle blocks the first outlet port to close the first feeding channel. Outlet; when the inner valve needle is in the first feeding position, the first feeding flow channel is connected with the first outlet to open the outlet of the first feeding flow channel, and the molten plastic enters the first feeding flow channel through the feeding hole and flows out through the first outlet; the inner wall of the discharge part is provided with a discharge groove along its circumference, and a through discharge hole is provided on the side of the discharge groove away from the discharge gap, and the discharge hole is connected with the discharge gap through the discharge groove. During the relative movement of the inner valve needle and the outer valve needle, the inner valve needle and the outer valve needle rub against each other, so that the waste material gathers in the discharge groove. Under the action of pressure, the waste material can be automatically discharged through the discharge hole, avoiding the waste material from entering the first feeding flow channel and affecting the appearance of the product, and preventing the waste material from accumulating and hindering the movement of the inner valve needle and the outer valve needle, thereby improving product quality, reducing the frequency of cleaning and repairing the valve needle, improving production efficiency, and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the internal structure of the hot runner system of the utility model;

[0026] Figure 2 It is a cross-sectional view of the valve needle of the present utility model;

[0027] Figure 3 yes Figure 2 Enlarged view of part A.

[0028] In the picture:

[0029] 1. External valve needle; 11. First discharge port; 12. Discharge portion; 121. Discharge trough; 122. Discharge hole; 123. External needle hanging platform; 13. First sealing portion; 14. First feed portion; 141. Feed hole;

[0030] 2. Inner valve needle; 21. Upper part; 22. Lower part; 23. Inner needle hanging platform;

[0031] 3. Discharge gap; 4. First feed channel;

[0032] 5. Main body; 51. Second discharge port; 52. Second sealing portion; 53. Second feeding portion; 54. Third sealing portion; 55. Third feeding portion; 56. First feeding port; 57. Second feeding port;

[0033] 6. Material storage bag; 7. Second material feeding channel. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0035] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0036] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0037] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0038] like Figures 1 to 3 As shown, this embodiment provides a valve needle, which includes an outer valve needle 1 and an inner valve needle 2. The outer valve needle 1 is hollow, and a first discharge port 11 is provided at the lower end of the outer valve needle 1. The inner valve needle 2 is slidably arranged in the outer valve needle 1 along the vertical direction to have a first sealing position that closes the first discharge port 11 and a first feeding position that opens the first discharge port 11; the outer valve needle 1 includes a discharge portion 12, a first sealing portion 13 and a first feeding portion 14 that are sequentially connected from top to bottom, a discharge gap 3 is formed between the upper portion 21 of the inner valve needle 2 and the discharge portion 12, and the upper portion 21 of the inner valve needle 2 can be sealed with the first sealing portion 13 A first material supply channel 4 is formed between the lower portion 22 of the inner valve needle 2 and the outer valve needle 1, and a material feed hole 141 is opened on the first material delivery portion 14, and the first material supply channel 4 is communicated with the material feed hole 141; when the inner valve needle 2 is located at the first sealing position, the lower end of the inner valve needle 2 blocks the first material outlet 11 to close the outlet of the first material supply channel 4; when the inner valve needle 2 is located at the first feeding position, the first material supply channel 4 is communicated with the first material outlet 11 to open the outlet of the first material supply channel 4, and the molten plastic enters the first material supply channel 4 through the material feed hole 141 and flows out through the first material outlet 11.

[0039] It is easy to understand that when the inner valve needle 2 moves between the first sealing position and the first feeding position, part of the molten plastic adheres to the inner valve needle 2, and waste will be generated between the sealed first sealing part 13 and the inner valve needle 2. In order to solve the above problem, the inner wall of the discharge part 12 is provided with a discharge groove 121 along its circumference, and the discharge groove 121 is provided with a through discharge hole 122 on the side away from the discharge gap 3. The discharge hole 122 is connected with the discharge gap 3 through the discharge groove 121. During the relative movement of the inner valve needle 2 and the outer valve needle 1, due to the mutual friction between the inner valve needle 2 and the outer valve needle 1, the waste can be squeezed and gathered into the discharge groove 121. Under the action of pressure, the waste can be automatically discharged through the discharge hole 122, avoiding the waste from entering the first feeding channel 4 and affecting the appearance of the product, and preventing the waste from accumulating and hindering the movement of the inner valve needle 2 and the outer valve needle 1, thereby improving product quality, reducing the frequency of cleaning and repairing the valve needle, improving production efficiency, and reducing production costs.

[0040] In addition, since the plastic material may not be completely dried, when the plastic material is heated to become molten plastic, water vapor will be generated. During injection molding production, bubbles, flow marks and cracks will appear on the product. The above setting is also conducive to the discharge of water vapor, thereby improving product quality.

[0041] Furthermore, the bottom of the discharge trough 121 is provided with at least two discharge holes 122, which are evenly spaced along the circumference of the outer valve needle 1, thereby improving discharge efficiency. Without affecting the structural strength of the outer valve needle 1, the greater the number of discharge holes 122, the higher the efficiency of waste discharge.

[0042] Furthermore, the width of the discharge trough 121 gradually decreases as it moves away from the inner valve needle 2. The width of the discharge trough 121 is greater on the side closest to the discharge gap 3, facilitating the entry and accumulation of waste into the discharge trough 121. The width of the discharge trough 121 gradually decreases as it moves away from the discharge gap 3, facilitating the guidance of waste into the discharge hole 122 for discharge. In this embodiment, the cross-sectional shape of the discharge trough 121 is trapezoidal, with the angles between the bottom and the sidewalls being obtuse, which facilitates the smooth entry of waste into the discharge hole 122 and prevents waste from accumulating in blind spots. Alternatively, the cross-sectional shape of the discharge trough 121 includes, but is not limited to, a V-shape or an arc, and is not limited here.

[0043] For ease of understanding, the length of the sealing portion is recorded as m, and the movement stroke of the inner valve needle 2 is recorded as n, where m≥n+5 mm to ensure the sealing effect and prevent the molten plastic from overflowing, and m≤n+10 mm to facilitate the waste material to enter the discharge portion 12 for discharge and prevent the waste material from accumulating in the first sealing portion 13 and affecting the relative movement of the inner valve needle 2 and the outer valve needle 1.

[0044] In addition, to facilitate the upward and downward movement of the inner valve needle 2 and the outer valve needle 1, an inner needle hanging platform 23 is provided on the top of the inner valve needle 2, and an outer needle hanging platform 123 is provided on the top of the outer valve needle 1. Both the inner needle hanging platform 23 and the outer needle hanging platform 123 are used to connect to the output end of the driving member. Since part of the valve needle is disposed inside the main body, the driving member and the main body are likely to block the discharge hole 122. To solve the above problem, the distance between the axis of the discharge hole 122 and the bottom of the outer needle hanging platform 123 is recorded as s, and 20 mm ≤ s ≤ 55 mm. This can ensure that the discharge hole 122 is located between the driving member and the main body, preventing the discharge hole 122 from being blocked, and facilitating the smooth discharge of waste through the discharge hole 122. The driving member includes but is not limited to a cylinder, etc.

[0045] It is understandable that due to the viscosity of molten plastic, when the top of the first feed channel 4 is always higher than the top of the feed hole 141 throughout the entire movement of the inner valve needle 2, the top of the first feed channel 4 is easily adhered to by molten plastic, forming material accumulation. The accumulated material is in a state of long-term heating, which can easily cause the injection molded product to turn yellow and black, affecting product quality. To solve the above problem, when the inner valve needle 2 is in the first sealing position, the top of the first feed channel 4 is located at the top of the feed hole 141. On the one hand, when the inner valve needle 2 moves upward, the molten plastic flowing in from the feed port can flush the top of the first feed channel 4, causing the molten plastic adhering to the top of the first feed channel 4 to flow downward, thereby avoiding material accumulation, thereby ensuring product quality and reducing the frequency of cleaning and repairing the valve needle. On the other hand, the feed hole 141 is always fully connected to the first feed channel 4, preventing the upper portion 21 of the inner valve needle 2 from blocking the feed hole 141, preventing it from affecting feeding efficiency and ensuring sufficient feeding.

[0046] Furthermore, one end of the lower portion 22 of the inner valve needle 2 close to the upper portion 21 of the inner valve needle 2 is processed with an arc transition that is recessed toward the axial direction of the inner valve needle 2, so that the lower portion 22 and the upper portion 21 have a smooth transition, thereby making the top of the first feed channel 4 smooth, avoiding the existence of dead corners where materials are easily accumulated.

[0047] The present embodiment further provides a hot runner system, comprising a main body 5 and a valve needle in any of the above embodiments, wherein a second discharge port 51 is provided at the lower end of the main body 5, and an outer valve needle 1 is slidably arranged in the main body 5 along the vertical direction, so as to have a second sealing position for closing the second discharge port 51 and a second feeding position for opening the second discharge port 51; the main body 5 comprises a second sealing portion 52, a second feeding portion 53, a third sealing portion 54 and a third feeding portion 55 which are sequentially connected from top to bottom, and the outer valve needle 1 is connected to the second sealing portion 52, the second feeding portion 53, the third sealing portion 54 and the third feeding portion 55. The second sealing portion 52 and the third sealing portion 54 are both sealed, and a storage bag 6 is formed between the outer valve needle 1 and the second feeding portion 53. The main body 5 is also provided with a first feed port 56 and a second feed port 57. The feed hole 141 is connected with the first feed port 56 through the storage bag 6. The molten plastic enters the storage bag 6 through the first feed port 56 and then enters the first feed channel 4 through the feed hole 141, so that the outer valve needle 1 does not need to align the feed hole 141 with the outlet of the first feed port 56. It can also realize the circulation of molten plastic, simplifying the installation process of the valve needle; a second material supply channel 7 is formed between the outer valve needle 1 and the third material feeding part 55, and the second material supply channel 7 is connected to the second material inlet 57; when the outer valve needle 1 is in the second sealing position, the lower end of the outer valve needle 1 blocks the second material outlet 51 to close the outlet of the second material supply channel 7; when the outer valve needle 1 is in the second feeding position, the second material supply channel 7 is connected to the second material outlet 51 to open the second material supply channel 7. At the outlet, the molten plastic enters the second feeding channel 7 through the second feeding port 57 and flows out through the second discharging port 51; wherein, the outer valve needle 1 is sealed with the second sealing part 52 to seal the upper part of the storage bag 6 to prevent the molten plastic in the storage bag 6 from overflowing; the outer valve needle 1 is sealed with the third sealing part 54 to seal the lower part of the storage bag 6 to isolate the storage bag 6 from the second feeding channel 7 to prevent the storage bag 6 and the molten plastic in the second feeding channel 7 from mixing with each other.

[0048] It is easy to understand that by controlling the inner valve needle 2 to switch between the first feeding position and the first sealing position, the feeding of the first feeding channel 4 can be accurately controlled, and by controlling the outer valve needle 1 to switch between the second feeding position and the second sealing position, the feeding of the second feeding channel 7 can be accurately controlled, so that the first feeding channel 4 and the second feeding channel 7 can be fed separately. Therefore, by supplying different colors of molten plastic to the first feed port 56 and the second feed port 57 respectively, two-color rubber can be supplied through the same hot runner system to achieve two-color injection molding.

[0049] Furthermore, the first feed portion 14 is provided with at least two feed holes 141. The molten plastic in the storage sac 6 enters the first feed channel 4 simultaneously through the at least two feed holes 141, thereby improving injection molding efficiency. Furthermore, the at least two feed holes 141 are evenly spaced along the circumference of the outer valve needle 1, resulting in a more even distribution of the molten plastic in various portions of the first feed channel 4, which is beneficial for improving injection molding quality.

[0050] In this embodiment, when the outer valve needle 1 is located at the second sealing position, the bottom of the feed hole 141 is located at the bottom of the storage bag 6. On the one hand, at the lowest point of the movement stroke of the outer valve needle 1, the feed hole 141 can be connected with the bottom of the storage bag 6, thereby improving the flow efficiency of the molten plastic at the bottom of the storage bag 6, preventing material accumulation at the bottom of the storage bag 6, and reducing the frequency of cleaning or repairing the hot runner system; on the other hand, the feed hole 141 can be completely connected with the storage bag 6, preventing the third sealing part 54 from blocking the feed hole 141, avoiding affecting the feeding efficiency, and ensuring sufficient feeding.

[0051] Furthermore, the height of the storage bag 6 is recorded as x, the movement stroke of the outer valve needle 1 is recorded as y, and the diameter of the feed hole 141 is recorded as z, x=y+z, so that in the complete movement stroke of the outer valve needle 1, the entire feed hole 141 is always fully connected with the storage bag 6, further ensuring the feeding efficiency and avoiding insufficient feeding of the first feed channel 4.

[0052] This embodiment also provides an injection mold, which is characterized in that it includes a mold body and the hot runner system of any of the above embodiments. A cavity is opened in the mold body, and the first discharge port 11 and the second discharge port 51 are both connected to the cavity. By applying the above hot runner system, two-color injection molding can be achieved, and the valve needle can automatically discharge waste material, avoiding material accumulation in the hot runner system, reducing the frequency of cleaning or repairing the injection mold, and improving product quality and increasing production efficiency.

[0053] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A valve needle, characterized in that: The invention comprises an outer valve needle (1) and an inner valve needle (2), wherein the outer valve needle (1) is hollow, and a first discharge port (11) is provided at the lower end of the outer valve needle (1), and the inner valve needle (2) is slidably arranged in the outer valve needle (1) along a vertical direction, so as to have a first sealing position for closing the first discharge port (11) and a first feeding position for opening the first discharge port (11); The outer valve needle (1) comprises a discharge portion (12), a first sealing portion (13) and a first feeding portion (14) which are sequentially connected from top to bottom; a discharge gap (3) is formed between the upper portion (21) of the inner valve needle (2) and the discharge portion (12); the upper portion (21) of the inner valve needle (2) can be sealed with the first sealing portion (13); a first feeding channel (4) is formed between the lower portion (22) of the inner valve needle (2) and the outer valve needle (1); a feeding hole (141) is provided on the first feeding portion (14); and the first feeding channel (4) is connected to the feeding hole (141); When the inner valve needle (2) is located at the first sealing position, the lower end of the inner valve needle (2) blocks the first discharge port (11) to close the outlet of the first feed channel (4); when the inner valve needle (2) is located at the first feed position, the first feed channel (4) is connected to the first discharge port (11) to open the outlet of the first feed channel (4); The inner wall of the discharge portion (12) is provided with a discharge groove (121) along its circumference, and a through discharge hole (122) is provided on a side of the discharge groove (121) away from the discharge gap (3), and the discharge hole (122) is communicated with the discharge gap (3) through the discharge groove (121).

2. The valve needle according to claim 1, characterized in that At least two discharge holes (122) are provided at the bottom of the discharge groove (121), and the at least two discharge holes (122) are evenly spaced and distributed along the circumference of the outer valve needle (1).

3. The valve needle according to claim 1, characterized in that The width of the discharge groove (121) gradually decreases in a direction away from the inner valve needle (2).

4. The valve needle according to claim 1, characterized in that n+5 mm≤m≤n+10 mm, wherein m is the length of the first sealing portion (13), and n is the movement stroke of the inner valve needle (2).

5. The valve needle according to claim 1, characterized in that 20 mm ≤ s ≤ 55 mm, wherein an outer needle hanging platform (123) is further provided at the upper end of the discharge portion (12), and s is the distance between the axis of the discharge hole (122) and the bottom of the outer needle hanging platform (123).

6. The valve needle according to any one of claims 1 to 5, characterized in that: When the inner valve needle (2) is located at the first sealing position, the top of the first material supply channel (4) is located at the top of the material feed hole (141).

7. A hot runner system, characterized in that: The valve needle comprises a main body (5) and any one of claims 1 to 6, wherein a second discharge port (51) is provided at the lower end of the main body (5), and an outer valve needle (1) is slidably arranged in the main body (5) along a vertical direction to have a second sealing position for closing the second discharge port (51) and a second feeding position for opening the second discharge port (51); The main body (5) includes a second sealing portion (52), a second feeding portion (53), a third sealing portion (54) and a third feeding portion (55) which are sequentially connected from top to bottom, the outer valve needle (1) is in sealing cooperation with the second sealing portion (52) and the third sealing portion (54), a storage bag (6) is formed between the outer valve needle (1) and the second feeding portion (53), the main body (5) is further provided with a first feed port (56) and a second feed port (57), the feed hole (141) is connected with the first feed port (56) through the storage bag (6), a second feed channel (7) is formed between the outer valve needle (1) and the third feeding portion (55), and the second feed channel (7) is connected with the second feed port (57); When the outer valve needle (1) is located at the second sealing position, the lower end of the outer valve needle (1) blocks the second discharge port (51) to close the outlet of the second supply channel (7); when the outer valve needle (1) is located at the second supply position, the second supply channel (7) is connected to the second discharge port (51) to open the outlet of the second supply channel (7).

8. The hot runner system according to claim 7, characterized in that: At least two feed holes (141) are provided on the first feeding portion (14); and / or, When the outer valve needle (1) is located at the second sealing position, the bottom of the feed hole (141) is located at the bottom of the storage bag (6).

9. The hot runner system according to claim 8, characterized in that: x=y+z, wherein x is the height of the storage bag (6), y is the movement stroke of the outer valve needle (1), and z is the diameter of the feed hole (141).

10. An injection mold, characterized in that: The hot runner system comprises a mold body and any one of claims 7 to 9, wherein a cavity is provided in the mold body, and the first discharge port (11) and the second discharge port (51) are both connected to the cavity.

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