A hot runner hot nozzle and method of operation thereof
By introducing an overflow cavity and an extension disc structure into the hot runner nozzle, the problem of molten plastic fluid being forced into the mold cavity when the valve needle is inserted into the gate is solved, achieving uniform product pressure and reducing sticking to the mold.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG HENGDAO TECH
- Filing Date
- 2023-06-30
- Publication Date
- 2026-05-19
AI Technical Summary
When the valve needle type hot runner nozzle inserts the valve needle into the gate, the molten plastic fluid in the gate is forced into the mold cavity, which increases the unevenness of product pressure and easily causes sticking to the mold.
A hot runner nozzle was designed, comprising an overflow chamber and an extension plate structure. The overflow chamber guides molten plastic fluid into the overflow chamber when the valve needle is inserted into the main gate, preventing it from entering the mold cavity. The extension plate seals the overflow chamber after the sub-gate is closed, ensuring uniform product pressure.
It reduces the impact of product pressure near the gate, improves product pressure uniformity, and reduces the occurrence of sticking to the mold.
Smart Images
Figure CN118082123B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hot runner technology, and in particular to a hot runner nozzle and its operation method. Background Technology
[0002] Currently, valve needle type hot runner nozzles are equipped with a gate. The nozzle is closed by inserting a valve needle into the gate, thereby stopping the injection. The gate can only be closed after the molten plastic in the mold cavity reaches a certain pressure value. Pressure holding is performed immediately after the gate is closed.
[0003] Before the valve needle is inserted into the gate, there is molten plastic fluid inside the gate. During the process of the valve needle being inserted into the gate, the molten plastic fluid inside the gate is forced into the mold cavity, which increases the product pressure value near the gate, affects the uniformity of the entire product, and easily leads to sticking to the mold. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hot runner nozzle and its operation method, which makes it less likely for high pressure to form near the gate and ensures good overall pressure uniformity of the product.
[0005] To achieve the above objectives, the technical solution of the present invention is as follows:
[0006] A hot runner nozzle includes a nozzle body, a valve needle disposed inside the nozzle body, the valve needle being movable up and down, a cavity provided inside the nozzle body, the nozzle body including a main gate located at the bottom of the cavity, the valve needle being able to insert into the main gate to close the main gate when it moves down, a slider assembly installed at the lower end of the valve needle, the slider assembly including a slider, the slider including a lifting plate, an overflow cavity provided at the lower end of the valve needle, the lower end of the overflow cavity being open, the lifting plate being inserted into the overflow cavity and being able to move up and down along the inner wall of the overflow cavity, the slider assembly also including a fixed plate, the upper end face of the fixed plate being attached to and fixed to the lower end face of the valve needle, a channel one provided inside the fixed plate, the upper end of the channel one being able to communicate with the overflow cavity;
[0007] The slider also includes an extension located below the slider, which passes downward through the fixed plate. The extension includes an extension plate located at the bottom. When the lifting plate moves upward, it can open the overflow chamber. The overflow chamber and the channel are connected to the inner cavity of the hot nozzle body. When the lifting plate moves upward until the upper end face of the extension plate is in contact with the fixed plate, the overflow chamber is closed. When the lifting plate moves downward and is in contact with the fixed plate, the lifting plate closes the overflow chamber.
[0008] The fixed plate has sliding grooves on both sides, and slider two is slidably connected and installed in the sliding grooves. Slider two can slide along the inner wall of the sliding groove. The extension plate includes extension rods on both sides. The outer side of the extension rods is provided with buckles. When the buckles are in the upper limit position, the bottom surface of the buckles is in contact with slider two, and slider two on both sides is in close contact with the outer wall of the extension rods.
[0009] The slide groove is also equipped with a slider 1, which can slide along the inner wall of the slide groove. Slider 1 is located outside slider 2. A spring 2 is set between slider 1 and slider 2. One end of spring 2 abuts against slider 1 and the other end abuts against slider 2.
[0010] When the slider moves outward, its outer end can be located outside the valve needle.
[0011] A method for operating a hot runner nozzle, comprising a hot runner nozzle, and further comprising the following steps:
[0012] ① The valve needle moves upward until its bottom is above the main gate, the main gate is in the open state, the lifting plate is in the lower limit position, the bottom surface of the lifting plate is in contact with the top surface of the fixed plate, the bottom of the overflow chamber is closed by the lifting plate, the overflow chamber is in the closed state, and the slider is in the outer limit position.
[0013] ② The valve needle moves downward, the outer end of slider one is inserted into the main gate, slider one on both sides moves inward, the lifting plate moves upward, the overflow chamber opens, and the buckle locks the upper end of slider two.
[0014] ③ When the valve needle moves upward and leaves the upper end of the main gate, slider one pops outward, the clamping force of slider two on the extension rod loosens, the buckle moves downward and pushes slider two outward, and the overflow chamber opens. When the lifting plate moves downward to the limit position, the overflow chamber closes again.
[0015] When slider one is in the outer limit position, the distance between the outer ends of the two sliders one is greater than the inner diameter of the main gate.
[0016] The main gate is connected to a mold at its lower end. The mold has a mold cavity, which includes a sub-gate located at the upper end. The sub-gate is connected to the main gate.
[0017] A pressure plate is connected to the lower end of the fixed plate, which can seal the upper end of the sub-gate.
[0018] During the downward movement of the extension plate, its bottom can abut against the upper end of the mold, so that the mold pushes the extension plate upward until the extension plate inserts into the pressure plate.
[0019] When the valve needle is just inserted into the main gate, the extension plate is located above the mold.
[0020] The beneficial effects of this invention are:
[0021] By setting an overflow cavity, when the valve needle is inserted into the main gate, the plastic fluid that was originally in the main gate is forced into the overflow cavity, thereby reducing the amount of plastic fluid entering the mold cavity and reducing the impact on the product pressure near the gate of the mold cavity. This results in better product pressure uniformity and reduces sticking to the mold.
[0022] By setting an extension plate, after the subgate is closed, the extension plate will seal the overflow chamber. When the valve needle opens the main gate, the plastic fluid in the overflow chamber will not flow to the main gate before the main gate is fully opened, thus preventing the plastic fluid from flowing out of the main gate during the valve needle opening process. Attached Figure Description
[0023] Figure 1 This is a cross-sectional view of an embodiment;
[0024] Figure 2 for Figure 1 Enlarged view of point A in the middle;
[0025] Figure 3 Partial cross-section of the embodiment Figure 1 ;
[0026] Figure 4 for Figure 3 Enlarged view of point B in the middle;
[0027] Figure 5 Partial cross-section of the embodiment Figure 2 ;
[0028] Figure 6 for Figure 5 Enlarged view of point C in the middle;
[0029] Figure 7 Partial cross-section of the embodiment Figure 3 ;
[0030] Figure 8 for Figure 7 Enlarged view at point D;
[0031] Figure 9 This is a cross-sectional view of the installation of slider one, spring two, slider two and fixed plate in the embodiment;
[0032] Figure 10 This is a top view of the distribution of the extension and the gate in the embodiment.
[0033] In the diagram: Cylinder assembly 1, manifold 2, runner 21, hot runner body 3, main gate 31, valve needle 4, overflow chamber 41, slide 42, slider assembly 5, slider 51, sliding part 511, lifting plate 512, extension part 513, extension plate 5131, extension rod 51311, buckle 513111, spring 1 52, slider 1 53, chamfer 1 531, spring 2 54, slider 2 55, chamfer 2 551, fixing plate 56, groove 561, channel 1 562, pressure plate 57, mold 6, mold cavity 61, sub-gate 611. Detailed Implementation
[0034] The technical solution of the present invention will be further described below through embodiments and in conjunction with the accompanying drawings.
[0035] like Figures 1-10 As shown, a hot runner nozzle includes a nozzle body 3, such as... Figure 1 As shown, the upper end of the hot nozzle body 3 is connected to the flow divider plate 2. The hot nozzle body 3 has a cavity inside, and the flow divider plate 2 has a flow channel 21 for injecting molten plastic. The plastic is injected into the cavity of the hot nozzle body 3 through the flow channel 21.
[0036] The upper end of the manifold 2 is connected to the cylinder assembly 1, and the hot nozzle body 3 is provided with a valve needle 4. The cylinder assembly 1 is connected to the upper end of the valve needle 4 and controls the valve needle 4 to move up and down.
[0037] The hot nozzle body 3 includes a main gate 31 located at the bottom of the cavity. The valve needle 4 can be inserted into the main gate 31 to close the main gate 31.
[0038] like Figure 2 As shown, the lower end of the valve needle 4 is provided with an overflow cavity 41, which is open at the lower end and is countersunk in shape. The overflow cavity 41 extends upward along the bottom surface of the valve needle 4. A slide 42 is provided above the overflow cavity 41, which extends upward along the upper wall of the overflow cavity 41.
[0039] like Figure 4 As shown, a slider assembly 5 is installed at the lower end of the valve needle 4. The slider assembly 5 includes a slider 51, which includes a lifting plate 512, a sliding part 511 located above the lifting plate 512, and an extension part 513 located below the lifting plate 512. The sliding part 511 is slidably connected to the slide rail 42 and can move up and down along the inner wall of the slide rail 42. A spring 52 is abutted at the upper end of the sliding part 511, and the upper end of the spring 52 abuts against the upper inner wall of the slide rail 42.
[0040] The outer diameter of the lifting plate 512 matches the inner diameter of the overflow cavity 41. The lifting plate 512 is inserted into the overflow cavity 41 and can move up and down along the inner wall of the overflow cavity 41. The lifting plate 512 can close the bottom opening of the overflow cavity 41. When plastic is squeezed into the bottom of the lifting plate 512, the lifting plate 512 rises and the plastic flows into the overflow cavity 41. When the pressure of the plastic fluid at the bottom of the lifting plate 512 decreases, under the action of the spring 5, the lifting plate 512 moves down and closes the bottom opening of the overflow cavity 41. During this process, the lifting plate 512 discharges the plastic fluid in the overflow cavity 41.
[0041] When the lifting plate 512 moves upward, it can open the overflow chamber 41. At this time, the overflow chamber 41, the channel 1 562 and the inner cavity of the hot nozzle body 3 are connected. When the lifting plate 512 moves upward until the upper end surface of the extension plate 5131 is in contact with the fixed plate 56, the overflow chamber 41 is closed. When the lifting plate 512 moves downward and is in contact with the fixed plate 56, the lifting plate 512 will close the overflow chamber 41.
[0042] The extension 513 extends downward along the bottom center of the lifting plate 512. The extension 513 includes an extension plate 5131 located at the bottom. The extension plate 5131 extends outward along the outer wall of the extension 513 to form a disc shape. The extension plate 5131 includes extension rods 51311 located on both sides. The extension rods 51311 extend upward along the upper end surface of the extension plate 5131. The extension rods 513111 are provided with buckles 513111 on the outer side. The buckles 513111 protrude outward to form a protrusion.
[0043] like Figure 4 , 6 As shown, the slider assembly 5 also includes a fixed plate 56, with an extension 513 passing downward through the fixed plate 56. The upper surface of the fixed plate 56 is attached to and fixed to the lower surface of the valve needle 4. A channel 562 is provided at the center of the inner side of the fixed plate 56, and the upper end of the channel 562 can communicate with the overflow chamber 41. Figure 6 As shown, the fixed plate 56 has sliding grooves 561 on both sides. Sliding slider 1 53 and sliding slider 2 55 are slidably connected and installed in the sliding grooves 561. Both sliding slider 1 53 and sliding slider 2 55 can slide along the inner wall of the sliding groove 561, with sliding slider 1 53 located outside sliding slider 2 55 on one side. A spring 2 54 is provided between sliding slider 1 53 and sliding slider 2 55, with the left and right ends of spring 2 54 respectively abutting against sliding slider 1 53 and sliding slider 2 55.
[0044] like Figure 4 As shown, the bottom outer side of slider 53 is provided with chamfer 531 so that when slider 53 enters the main gate 31 downwards, it moves more smoothly inwards.
[0045] The inner side of slider 2 55 is provided with chamfer 2 551, so that when the buckle 513111 enters the inner side of slider 2 55 from the lower end of slider 2 55, it is convenient to push slider 2 55 outward.
[0046] like Figure 4 As shown, a pressure plate 57 is connected to the lower end of the fixed plate 56, which closes the lower end of the slide groove 561. The upper surface of the pressure plate 57 is in contact with the lower surfaces of slider 1 53 and slider 2 55. Both slider 1 53 and slider 2 55 have protrusions on their lower surfaces, and the upper surface of the pressure plate 57 has a groove. The protrusions of slider 1 53 and slider 2 55 are inserted into the groove of the pressure plate 57, thus limiting the sliding distance of slider 1 53 and slider 2 55 to prevent them from sliding too far. The pressure plate 57 has a through hole in the center, such as... Figure 8As shown, when the extension disc 5131 moves upward, it fits perfectly into the through hole of the pressure plate 57. The upper end of the extension disc 5131 is in contact with the lower end face of the fixed disc 56. During the upward movement, the latch 513111 pushes the slider 2 55 outward. When the latch 513111 reaches its limit position, the sliders 2 55 on both sides move inward under the action of spring force. The latch 513111 locks onto the upper end of the slider 2 55, and the bottom surface of the latch 513111 is in contact with the upper end of the slider 2 55. The sliders 2 55 on both sides are pressed tightly against the outer wall of the extension rod 51311, thus preventing the extension disc 5131 from moving up and down (as shown). Figure 3 , 4 As shown, at this time, the valve needle 4 is inserted into the main gate 31, that is, the outer sides of the two sliders 53 are restricted by the inner wall of the main gate 31, so that the sliders 53 cannot extend the valve needle 4 outward. Therefore, when the sliders 53 are in this position, the sliders 55 can push the extension rod 51311 inward, and the buckle 513111 can be locked on the upper end of the sliders 55.
[0047] When the valve needle 4 is away from the main gate 31, the inner wall of the main gate 3 does not limit the movement of slider 53. At this time, after slider 53 moves outward, its outer end is located outside the valve needle 4. In this state, because spring 54 pushes slider 53 outward, spring 54 extends and its elastic force decreases. Therefore, the elastic force of spring 54 on slider 55 decreases. At the moment the valve needle 4 leaves the main gate 31, slider 53 pops outward, causing slider 55 to move slightly outward. This causes slider 55 to loosen from extension rod 51311. The bottom outer side of the buckle 513111 has a chamfered structure. Under the action of spring 52, buckle 513111 is squeezed between the two sliders 55 and moves downward, so that the lifting plate 512 pushes the plastic fluid in the overflow chamber 41 downward into the hot nozzle body 3 cavity.
[0048] A method for operating a hot runner nozzle, comprising the aforementioned structure of a hot runner nozzle, wherein the method of operation is as follows:
[0049] ①For example Figure 3 , 4 As shown, the valve needle 4 moves upward under the drive of the cylinder assembly 1, and the bottom of the valve needle 4 is located above the main gate 31. The lifting plate 512 is located at the lower limit position under the action of the spring 52. At this time, the bottom surface of the lifting plate 512 is in contact with the fixed plate 56, and the bottom of the overflow chamber 41 is closed by the lifting plate 512, and the overflow chamber 41 is in the closed state.
[0050] Slider 53 is located at its outer limit position, with its outer end extending beyond the outer wall of valve needle 4. The distance between the outer ends of the two sliders 53 is greater than the inner diameter of the main gate 31.
[0051] like Figure 3As shown, the main gate 31 is in the open state at this time. The mold 6 is connected below the main gate 31. The mold 6 has a mold cavity 61, and the mold cavity 61 is correspondingly provided with a sub-gate 611. The upper end of the sub-gate 611 is connected to the main gate 31. In this state, plastic fluid is injected into the hot runner body 3, and the plastic fluid flows into the mold cavity 61 through the main gate 31 and the sub-gate 611.
[0052] ② After the pressure of the plastic fluid in the mold cavity 61 reaches the specified pressure, the valve needle 4 moves downward under the action of the cylinder assembly 1, and inserts into the main gate 31 to close it. Just as the valve needle 4 inserts into the main gate 31, the outer end of the slider 53 engages within the main gate 31, and both sliders 53 move inward. During the insertion of the valve needle 4 into the main gate 31, if... Figure 6 As shown, due to the gradual increase in pressure of the plastic fluid in the main gate 31, which pushes the lifting plate 512 to move upward, the overflow chamber 41 opens, and the plastic fluid flows into the overflow chamber 41.
[0053] As the lifting plate 512 moves upward, the spring 52 is compressed and the spring force gradually increases, making it difficult for the lifting plate 512 to be pushed by the pressure of the plastic fluid alone. Therefore, during the middle stage of the insertion of the valve needle 4 into the main gate 31, the bottom of the extension plate 5131 abuts against the upper surface of the mold 6, as... Figure 8 As shown, until slider 2 55 clamps the extension rod 51311, and buckle 513111 clamps the upper end of slider 2 55, the vertical movement of slider 51 is restricted, the bottom surface of extension plate 5131 is in contact with mold 6, and pressure plate 57 closes and seals the upper end of gate 611, and pressure is maintained in mold cavity 61.
[0054] ③ After the pressure holding period ends, the valve needle 4 moves upward, and before it leaves the main gate 31, the latch 513111 restricts the slide block 51 from moving up and down, and the extension plate 5131 closes the bottom of the overflow cavity 41, preventing the fluid in the overflow cavity 41 from flowing out, which is beneficial for demolding. When the valve needle 4 moves upward and leaves the upper end of the main gate 31, the slide block 53 pops outward under the action of the spring 54, and the clamping force of the slide block 55 on the extension rod 51311 loosens. Under the action of the spring 52, the latch 513111 moves downward and pushes the slide block 55 outward, opening the overflow cavity 41 and allowing the fluid in the overflow cavity 41 to flow out. When the lifting plate 512 moves downward to its limit position, the overflow cavity 41 closes again.
[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A hot runner nozzle, comprising a nozzle body (3), wherein a valve needle (4) is disposed within the nozzle body (3), the valve needle (4) moves up and down, the nozzle body (3) has a cavity, the nozzle body (3) includes a main gate (31) located at the bottom of the cavity, and the valve needle (4) moves down and inserts into the main gate (31) to close the main gate (31), characterized in that: The lower end of the valve needle (4) is equipped with a slider assembly (5), the slider assembly (5) includes a slider (51), the slider (51) includes a lifting plate (512), the lower end of the valve needle (4) is provided with an overflow cavity (41), the lower end of the overflow cavity (41) is open, the lifting plate (512) is inserted into the overflow cavity (41) and moves up and down along the inner wall of the overflow cavity (41), the slider assembly (5) also includes a fixing plate (56), the upper end face of the fixing plate (56) is attached to and fixed to the lower end face of the valve needle (4), the inner side of the fixing plate (56) is provided with a channel (562), the upper end of the channel (562) is connected to the overflow cavity (41); The slider (51) includes an extension (513) located below the slider (51), the extension (513) passing downward through the fixed plate (56), the extension (513) including an extension plate (5131) located at the bottom, when the lifting plate (512) moves upward, the overflow cavity (41) is opened, the overflow cavity (41) and the channel 1 (562) are connected to the inner cavity of the hot nozzle body (3), when the lifting plate (512) moves upward until the upper end surface of the extension plate (5131) is in contact with the fixed plate (56), the overflow cavity (41) is closed, when the lifting plate (512) moves downward and is in contact with the fixed plate (56), the lifting plate (512) closes the overflow cavity (41); The fixed plate (56) has sliding grooves (561) on both sides. A slider two (55) is slidably connected and installed in the sliding groove (561). The slider two (55) slides along the inner wall of the sliding groove (561). The extension plate (5131) includes extension rods (51311) located on both sides. The extension rods (51311) have buckles (513111) on the outer side. When the buckles (513111) are in the upper limit position, the bottom surface of the buckles (513111) is in contact with the slider two (55), and the slider two (55) on both sides is close to the outer wall of the extension rods (51311). The groove (561) is also equipped with a slider one (53), which slides along the inner wall of the groove (561). The slider one (53) is located outside the slider two (55). A spring two (54) is provided between the slider one (53) and the slider two (55). One end of the spring two (54) abuts against the slider one (53) and the other end abuts against the slider two (55).
2. The hot runner nozzle as described in claim 1, characterized in that: The slider (53) moves outward and its outer end is located outside the valve needle (4).
3. The method for operating a hot runner nozzle according to claim 1 or 2, characterized in that: Includes the following steps: ① The valve needle (4) moves upward until its bottom is above the main gate (31), the main gate (31) is in the open state, the lifting plate (512) is in the lower limit position, the bottom surface of the lifting plate (512) is in contact with the top surface of the fixed plate (56), the bottom of the overflow cavity (41) is closed by the lifting plate (512), the overflow cavity (41) is in the closed state, and the slider (53) is in the outer limit position; ② The valve needle (4) moves downward, the outer end of the first slider (53) is inserted into the main gate (31), the first slider (53) on both sides moves inward, the lifting plate (512) moves upward, the overflow chamber (41) opens, and the buckle (513111) locks the upper end of the second slider (55); ③ When the valve needle (4) moves upward and leaves the upper end of the main gate (31), the first slider (53) pops outward, the second slider (55) loosens its clamping force on the extension rod (51311), the buckle (513111) moves downward and pushes the second slider (55) outward, and the overflow chamber (41) opens. When the lifting plate (512) moves downward to the limit position, the overflow chamber (41) closes again.
4. The operating method of a hot runner nozzle as described in claim 3, characterized in that: When the slider 1 (53) is in the outer limit position, the distance between the outer ends of the two sliders 1 (53) is greater than the inner diameter of the main gate (31).
5. The operating method of a hot runner nozzle as described in claim 3, characterized in that: The main gate (31) is connected to a mold (6) at its lower end. The mold (6) has a mold cavity (61) inside. The mold cavity (61) includes a sub-gate (611) located at the upper end. The sub-gate (611) is connected to the main gate (31).
6. The operating method of a hot runner nozzle as described in claim 5, characterized in that: The lower end of the fixed plate (56) is connected to a pressure plate (57), which closes the upper end of the sub-gate (611).
7. The operating method of a hot runner nozzle as described in claim 6, characterized in that: As the extension disc (5131) descends, its bottom abuts against the upper end of the mold (6), causing the mold (6) to push the extension disc (5131) upward until the extension disc (5131) inserts into the pressure plate (57).
8. The method for operating a hot runner nozzle as described in claim 5, characterized in that: When the valve needle (4) is just inserted into the main gate (31), the extension plate (5131) is located above the mold (6).