Double-layer multi-point needle valve cylinder structure

Abstract

A double-layer multi-point needle valve air cylinder structure comprises a cylinder body and a piston, a containing cavity for containing the piston is formed in the cylinder body, the piston is connected with a plurality of valve needles, an opening is formed in the bottom of the cylinder body, a partition plate is arranged in the containing cavity, and the piston penetrates through the partition plate in a sliding mode. A partition plate is arranged in the containing cavity and divides the containing cavity into a first cavity body and a second cavity body, a protruding clamping ring and a base plate are arranged on the peripheral side of the piston, the clamping ring and the base plate are located in the first cavity body and the second cavity body respectively, and the outer end of the clamping ring and the outer end of the base plate abut against the inner wall of the cylinder body. The piston and the cylinder body are provided with a first channel and a second channel respectively, the first cavity and the second cavity are communicated through the first channel and the second channel, and the cylinder body is provided with a first ventilation opening and a second ventilation opening. And the first air vent and the second air vent are respectively communicated with the first cavity and the second cavity. The double-layer structure is arranged in the cylinder body, the force borne by the piston can be greatly increased, the glue sealing strength is improved, the product surface quality is improved, and the double-layer structure can be suitable for the use condition of a plurality of valve needles.

Description

Technical Field

[0001] This utility model relates to the field of hot runner injection molding technology, and more specifically, to a double-layer multi-point needle valve cylinder structure. Background Technology

[0002] In a needle valve hot runner injection molding system, a valve needle is installed inside the hot nozzle. The valve needle is used to open and close the gate at the bottom of the hot nozzle. During injection, the valve needle moves upward to open the gate (i.e., the needle retracts), and the molten material flows out from the gate for injection. When the injection is completed, the cylinder drives the valve needle to move downward, and the valve needle seals the gate at the bottom of the hot nozzle, so that the material no longer flows out, thus achieving sealing.

[0003] Currently, when injection molding some engineering plastics and plastics with added glass fiber, the rapid cooling of engineering materials and the hardness of glass fiber-containing materials result in significant resistance to the valve needle during sealing, potentially leading to incomplete gate sealing and leakage. Furthermore, when injection molding larger products, the high injection pressure can result in insufficient sealing force from the valve needle, causing incomplete or failed sealing at the gate, leading to leakage from the hot runner after sealing. This results in surface quality issues such as burrs and bumps, severely impacting the quality of the finished product. Additionally, some products require multiple injection points within a very close proximity. Due to the close spacing between hot runners, it's impossible to use a separate cylinder to drive the valve needle for each runner. Therefore, a single cylinder is needed to drive multiple valve needles. However, the sealing force required for multiple valve needles is substantial, and ordinary cylinder structures often lack sufficient sealing force, easily leading to incomplete sealing. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a double-layer multi-point needle valve cylinder structure with strong sealing force and high reliability.

[0005] A double-layer multi-point needle valve cylinder structure includes a cylinder body and a piston. The cylinder body has a receiving cavity for accommodating the piston. The piston is connected to several valve needles. The bottom of the cylinder body has an opening. A partition plate is provided in the receiving cavity. The piston slides through the partition plate, which divides the receiving cavity into a first cavity and a second cavity. A protruding retaining ring and a pad are provided on the periphery of the piston. The retaining ring and the pad are located in the first cavity and the second cavity, respectively. The outer ends of the retaining ring and the pad abut against the inner wall of the cylinder body. The piston and the cylinder body are respectively provided with a first channel and a second channel, which connect the first cavity and the second cavity. The cylinder body is provided with a first vent and a second vent, which are respectively connected to the first cavity and the second cavity.

[0006] In the above technical solution, the receiving cavity is divided into a first cavity and a second cavity, which are distributed vertically, by a partition plate. The first channel and the second channel are used to allow gas to transfer between the two cavities. The two ends of the second channel are connected to the bottom of the first cavity and the second cavity, respectively, so that the connection point of the second channel with the first cavity is always below the retaining ring, and the connection point with the second cavity is always below the pad. In specific operation, when it is necessary to drive the valve needle to move downward to seal, gas is introduced from the first vent, and the gas enters the upper part of the first cavity. A part of the gas enters the upper part of the second cavity through the first channel on the piston. At the same time, the gas applies pressure to the top of the piston and the top of the pad, causing the piston to drive the valve needle to move downward. When it is necessary to drive the valve needle to move upward, gas is introduced from the bottom of the second cavity through the second vent, and a part of the gas enters from the bottom of the first cavity through the second channel on the cylinder. The gas applies a thrust to the bottom of the pad and the retaining ring, thereby causing the piston to move upward and driving the valve needle upward.

[0007] It should be noted that, due to the presence of retaining rings and gaskets on the piston, the formula: Pressure = Pressure Intensity * Projected Area (F = P * S) shows that, under the same intake pressure P, the retaining rings and gaskets allow the piston to have a larger projected area S. Therefore, the piston can receive a greater pressure F, which in turn provides a greater sealing force to the valve needle, enabling the valve needle to successfully seal the gate, effectively preventing hot nozzle leakage, eliminating product burrs, and improving product quality.

[0008] Furthermore, the pad is sleeved and installed on the piston, and the piston has a protruding limiting end on its periphery, which abuts against the top of the piston.

[0009] In the above technical solution, the end face formed at the bottom of the limiting end abuts against the top of the piston, limiting the piston from above.

[0010] Furthermore, a retaining ring is detachably mounted on the piston, and the retaining ring abuts against the bottom of the pad.

[0011] In the above technical solution, the retaining ring abuts against the bottom of the pad, limiting the piston from below. Through the upper and lower limiting ends and the retaining ring, the pad is fixed on the piston to prevent it from moving up and down. The retaining ring and the piston are detachably connected, and the pad can be removed from the piston by removing the retaining ring.

[0012] Furthermore, the piston has several mounting grooves extending along the height direction inside, and the valve needle is installed in the mounting grooves.

[0013] In the above technical solution, the mounting groove is used to install and fix the valve needle, and one valve needle is installed in each mounting groove.

[0014] Furthermore, a fixing plug and a buffer pad are also installed in the mounting groove. The fixing plug is located above the valve needle, and the buffer pad is located between the fixing plug and the valve needle.

[0015] In the above technical solution, the fixing plug is fixedly installed in the mounting groove to limit the valve needle and prevent the valve needle from being pushed out of the piston. A buffer pad is provided between the fixing plug and the valve needle to buffer and prevent the valve needle from being damaged due to excessive instantaneous force.

[0016] Furthermore, a sealing ring is embedded in the outer periphery of the buffer pad.

[0017] In the above technical solution, the sealing ring is used to seal the piston, ensuring its airtightness and preventing gas leakage from the mounting groove.

[0018] Furthermore, sealing rings are embedded in the contact surfaces of the retaining ring and the inner wall of the cylinder, the contact surfaces of the pad and the piston and cylinder, and the contact surfaces of the partition plate and the piston.

[0019] In the above technical solution, by setting a sealing ring on the contact surface between the retaining ring, the partition plate, the piston and the cylinder, the sealing between the first chamber and the second chamber is effectively guaranteed, and gas leakage is prevented.

[0020] Furthermore, it also includes an installation template, in which the cylinder body is installed. The side of the installation template is provided with a first air inlet and a second air inlet, the first air inlet being connected to the first vent, and the second air inlet being connected to the second vent.

[0021] In the above technical solution, the mounting template has a cavity for cylinder installation, and the external air supply device is connected to the first air supply hole and the second air supply hole on the mounting template, through which gas is introduced into the cylinder.

[0022] Furthermore, a cylinder head is connected to the top of the cylinder block, and the cylinder head is mounted on the mounting template.

[0023] In the above technical solution, the cylinder body is installed in the cavity inside the mounting template. The top of the cylinder body is connected to the cylinder head by screws or other fasteners. The cylinder head covers the cylinder body inside the mounting template, thereby making the cylinder body stably installed inside the mounting template.

[0024] Compared with the prior art, the beneficial effects of this application are as follows:

[0025] The cylinder body of this application has a first chamber and a second chamber that are connected to each other. A retaining ring and a gasket are installed on the piston. When valve needle sealing is required, gas enters the first chamber, and a portion of the gas can enter the second chamber through the first channel. At this time, the gas simultaneously applies pressure to the top of the retaining ring and the gasket, causing the piston to move downwards. Similarly, when valve needle retraction is required, gas enters the second chamber, and a portion of the gas can enter the first chamber through the second channel. At this time, the gas simultaneously applies pressure to the bottom of the retaining ring and the gasket, causing the piston to move the valve needle upwards. By setting the cylinder body to a double-layer structure and installing a retaining ring and a gasket on the piston, this application can greatly increase the pressure on the piston while maintaining a constant inlet pressure. This results in a greater sealing force for the valve needle, effectively preventing hot nozzle leakage, improving the sealing effect, and ensuring the quality of injection molded products. Furthermore, due to the large sealing force, multiple valve needles can be installed on the piston, making it suitable for situations where the injection points are close together, thus demonstrating strong practicality. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a double-layer multi-point needle valve cylinder structure according to one embodiment.

[0028] Figure 2 This is a schematic diagram of the air intake state inside the cylinder when the piston moves down (when the valve needle is sealed).

[0029] Figure 3 This is a schematic diagram of the air intake state inside the cylinder when the piston moves upward (when the valve needle retracts).

[0030] Explanation of the reference numerals in the figure:

[0031] 1-Cylinder block; 11-First chamber; 12-Second chamber; 13-Second channel; 14-First vent; 15-Second vent; 2-Piston; 21-First channel; 22-Snap ring; 23-Pan plate; 24-Limiting end; 25-Snap ring; 26-Mounting groove; 27-Fixing plug; 28-Buffer pad; 3-Valve needle; 4-Sealing ring; 5-Mounting template; 51-First air inlet; 52-Second air inlet; 6-Cylinder head. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] Please refer to Figures 1 to 3 In a preferred embodiment of this application, a double-layer multi-point needle valve cylinder structure is provided, which includes a cylinder body 1 and a piston 2. The cylinder body 1 has a receiving cavity for accommodating the piston 2. The piston 2 is connected to two valve needles 3. The bottom of the cylinder body 1 has an opening for the valve needles 3 to pass through. A horizontally arranged partition plate is provided in the receiving cavity. The piston 2 slides through the partition plate, which divides the receiving cavity into a first cavity 11 and a second cavity 12. A protruding retaining ring 22 and a pad 23 are provided on the periphery of the piston 2. The retaining ring 22 and the pad 23 are respectively located at... Inside the first cavity 11 and the second cavity 12, the outer ends of the retaining ring 22 and the pad 23 abut against the inner wall of the cylinder 1. The piston 2 and the cylinder 1 are respectively provided with a first channel 21 and a second channel 13, which connect the first cavity 11 and the second cavity 12. The cylinder 1 is provided with a first vent 14 and a second vent 15. The first vent 14 is located at the top of the side of the cylinder 1 and is connected to the first cavity 11. The second vent 15 is located at the bottom of the side of the cylinder 1 and is connected to the second cavity 12.

[0036] Understandably, to ensure that piston 2 can move in the correct direction, one end of the first channel 21 is located at the top of piston 2, and the other end is located above the pad 23. The two ends of the second channel 13 are connected to the bottom of the first cavity 11 and the second cavity 12, respectively, so that the connection point of the second channel 13 with the first cavity 11 is always below the retaining ring 22, and the connection point with the second cavity 12 is always below the pad 23. This arrangement guides the incoming gas, ensuring that when piston 2 needs to move downwards, the gas always applies pressure from the top of the retaining ring 22 and the pad 23, and when piston 2 needs to move upwards, the gas always applies pressure from the bottom of the retaining ring 22 and the pad 23.

[0037] Specifically, when applying sealant, such as Figure 2 As shown (the red arrow in the figure indicates the gas direction), gas enters from the first vent 14 and enters the upper part of the first chamber 11. A portion of the gas enters the upper part of the second chamber 12 through the first channel 21 on the piston 2. At this time, the gas simultaneously applies pressure to the top of the piston 2 and the top of the pad 23, causing the piston 2 to move the valve needle 3 downwards. During needle retraction, as... Figure 3 As shown (the red arrow in the figure indicates the direction of the gas), the gas enters from the bottom of the second chamber 12 through the second vent 15. A portion of the gas enters from the bottom of the first chamber 11 through the second channel 13 on the cylinder 1. At this time, the gas simultaneously exerts a thrust on the bottom of the pad 23 and the retaining ring 22, causing the piston 2 to drive the valve needle 3 to move upward.

[0038] It should be noted that, according to the formula: Pressure = Pressure * Projected Area (F = P * S), under the same intake pressure P, setting the retaining ring 22 and the pad 23 can make the piston 2 have a larger projected area S. Therefore, the piston 2 can obtain a greater pressure F, which can provide a greater sealing force to the valve needle 3, so that the valve needle 3 can smoothly seal the gate, effectively avoid hot nozzle glue leakage, eliminate product burrs, and improve product surface quality.

[0039] Preferably, refer to Figure 1 Multiple channels are provided for both the first channel 21 and the second channel 13 to ensure that the gas can be transferred between the two chambers more quickly. The number of channels 21 and 13 can be flexibly adjusted according to actual needs. In addition, the number of valve needles 3 can also be adjusted according to actual needs.

[0040] Please refer to Figure 1In this embodiment, the pad 23 is sleeved on the piston 2 for easy assembly and disassembly. The piston 2 has a protruding limiting end 24 around its periphery. The bottom end face of the limiting end 24 abuts against the top of the piston 2, limiting the piston 2 from above. In addition, a retaining spring 25 is detachably installed on the piston 2. The retaining spring 25 is located at the bottom of the pad 23 and abuts against the bottom of the pad 23, limiting the piston 2 from below. Through the upper and lower limiting ends 24 and the retaining spring 25, the pad 23 is fixed on the piston 2, preventing it from moving up and down. The retaining spring 25 is detachably connected to the piston 2. When needed, the pad 23 can be removed from the piston 2 by removing the retaining spring 25.

[0041] Please refer to Figure 1 In this embodiment, since there are two valve needles 3, the piston 2 is provided with two mounting grooves 26 that extend along the height direction. The mounting grooves 26 are used to install and fix the valve needles 3, and one valve needle 3 is installed in each mounting groove 26.

[0042] Please refer to Figure 1 In this embodiment, a fixing plug 27 and a buffer pad 28 are also installed in the mounting groove 26. The fixing plug 27 and the buffer pad 28 are located at the top of the valve needle 3, and the buffer pad 28 is located between the fixing plug 27 and the valve needle 3. The fixing plug 27 is fixedly installed in the mounting groove 26 to limit the valve needle 3 and prevent the valve needle 3 from being pushed out of the piston 2. The buffer pad 28 is provided between the fixing plug 27 and the valve needle 3 to buffer and prevent the valve needle 3 from being damaged due to excessive instantaneous force. In addition, the mounting groove 26 is a stepped groove, and the top of the valve needle 3 is provided with a protruding limiting ring. The stepped surface of the mounting groove 26 can also limit the valve needle 3.

[0043] Preferably, the buffer gasket 28 is a double-layer gasket composed of two gaskets connected together to increase the contact area with the sealing surface and improve the sealing performance. In addition, a sealing ring 4 is embedded in the outer periphery of the buffer gasket 28 to effectively ensure the sealing performance of the piston 2.

[0044] Please refer to Figure 1 In some embodiments, sealing rings 4 (i.e., the gray filled area in the figure) are embedded on the contact surfaces where the retaining ring 22 contacts the inner wall of the cylinder 1, the pad 23 contacts the piston 2, the pad 23 contacts the cylinder 1, and the partition plate contacts the piston 2. By setting the sealing rings 4 on the contact surfaces where the retaining ring 22, the partition plate, the piston 2 and the cylinder 1 contact each other, the sealing between the first cavity 11 and the second cavity 12 can be effectively guaranteed, gas leakage can be prevented, and reliability can be improved.

[0045] Please refer to Figures 1 to 3In this embodiment, the cylinder body 1 is provided with an installation template 5 on its exterior. The installation template 5 has a cavity inside for the cylinder body 1 to be installed. The side of the installation template 5 is provided with a first air supply hole 51 and a second air supply hole 52. The first air supply hole 51 is connected to the first air vent 14, and the second air supply hole 52 is connected to the second air vent 15. An external air supply device is connected to the first air supply hole 51 and the second air supply hole 52 on the installation template 5, and gas is introduced into the cylinder body 1 through the first air supply hole 51 and the second air supply hole 52.

[0046] Preferably, a sealing ring 4 (i.e., the gray filling part in the figure) is also provided on the contact surface of the outer side of the cylinder body 1 that contacts the mounting template 5.

[0047] Please refer to Figure 1 In this embodiment, the top of the cylinder body 1 is provided with a cylinder cover 6. The cylinder cover 6 is connected to the mounting template 5 by fasteners such as screws. The cylinder cover 6 is connected to the top of the cylinder body 1 by fasteners such as screws. The cylinder body 1 is covered inside the mounting template 5 by the cylinder cover 6, so that the cylinder body 1 is stably installed inside the mounting template 5. At the same time, when disassembly is required, the cylinder body 1 can also be taken out from inside the mounting template 5 through the cylinder cover 6.

[0048] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

[0049] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0051] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

Claims

1. A double-layer multi-point needle valve cylinder structure, comprising a cylinder body and a piston, characterized in that, The cylinder body has an internal cavity for accommodating the piston. The piston is connected to several valve needles. The bottom of the cylinder body has an opening. A partition plate is provided inside the cavity. The piston slides through the partition plate, which divides the cavity into a first cavity and a second cavity. A protruding retaining ring and a washer are provided on the periphery of the piston. The retaining ring and the washer are located in the first cavity and the second cavity, respectively. The outer ends of the retaining ring and the washer abut against the inner wall of the cylinder body. The piston and the cylinder body are respectively provided with a first channel and a second channel, which connect the first cavity and the second cavity. The cylinder body is provided with a first vent and a second vent, which are respectively connected to the first cavity and the second cavity.

2. The double-layer multi-point needle valve cylinder structure according to claim 1, characterized in that, The pad is sleeved and installed on the piston, and the piston has a protruding limiting end on its periphery, which abuts against the top of the piston.

3. The double-layer multi-point needle valve cylinder structure according to claim 2, characterized in that, A retaining ring is detachably mounted on the piston, and the retaining ring abuts against the bottom of the pad.

4. The double-layer multi-point needle valve cylinder structure according to claim 1, characterized in that, The piston has several mounting grooves that extend along the height direction inside, and the valve needle is installed in the mounting grooves.

5. The double-layer multi-point needle valve cylinder structure according to claim 4, characterized in that, The mounting groove is also equipped with a fixing plug and a buffer pad. The fixing plug is located above the valve needle, and the buffer pad is located between the fixing plug and the valve needle.

6. The double-layer multi-point needle valve cylinder structure according to claim 5, characterized in that, A sealing ring is embedded in the outer periphery of the buffer pad.

7. The double-layer multi-point needle valve cylinder structure according to claim 1, characterized in that, Sealing rings are embedded in the contact surfaces of the retaining ring and the inner wall of the cylinder, the contact surfaces of the pad and the piston and cylinder, and the contact surfaces of the partition plate and the piston.

8. The double-layer multi-point needle valve cylinder structure according to claim 1, characterized in that, It also includes an installation template, in which the cylinder body is installed. The side of the installation template is provided with a first air inlet and a second air inlet. The first air inlet is connected to the first vent, and the second air inlet is connected to the second vent.

9. The double-layer multi-point needle valve cylinder structure according to claim 8, characterized in that, The top of the cylinder block is connected to a cylinder cover, which is mounted on the mounting template.

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