A layered injection molding gate device and injection molding process using the same

Abstract

The application discloses a layered injection molding gate device, which comprises a front-stage mold, a lower gate sleeve, a combined gate formed by two gates, an upper gate sleeve and a valve needle, the valve needle is slidably penetrated through the lower gate sleeve, the combined gate and the upper gate sleeve along an axis, the diameter of the valve needle is matched with the caliber of the lower gate sleeve and the bottom center opening of the combined gate, the front-stage mold comprises a movable mold and a fixed mold, the movable mold is movably connected with the fixed mold, the movable mold is connected with a movable mold servo driving mechanism, the bottom of the lower gate sleeve is embedded in a center cavity of the movable mold, a center drainage pipe extending into the fixed mold is fixed in the center cavity of the movable mold, and the diameter of the center drainage pipe is matched with the caliber of the lower gate sleeve and the bottom center opening of the combined gate. The application further discloses a servo control multi-layer material injection molding system forming process adopting the layered injection molding gate device. The application can shorten the production cycle, improve the production efficiency, facilitate quality control and production management.

Description

TECHNICAL FIELD

[0001] The present application relates to a layered injection molding gate device and an injection molding process using the same. BACKGROUND

[0002] Tool handles have different needs due to changes in use conditions, so it is often necessary to combine multiple materials with different properties through a multi-layer material injection molding process to meet different needs and improve product value. Currently, tool handles are often formed into encapsulated or sandwich structures through multiple injection molding processes. However, during the multiple injection molding processes, the semi-finished product often undergoes a long storage and circulation process, and the surface temperature is low. If the melting temperature of the covering material is too low after being put into the machine, the semi-finished product base material surface cannot be melted, and the adhesion between the two is not strong enough. Therefore, the covering material must be heated sufficiently. This not only requires a longer heating time, lengthening the process cycle, but also requires precise temperature control. Otherwise, if the melting temperature is too high, the semi-finished product base material will soften and deform, and in severe cases, the covering material will penetrate the base material, resulting in a failed part processing. Therefore, the multi-layer material injection molding process and device need to be continuously improved. The invention patent with publication number CN112743750A discloses a screwdriver handle encapsulation process, which includes the following steps: step one, using nylon as raw material, heating and melting, then injecting into the screwdriver handle skeleton mold, after pressure holding and cooling, the screwdriver handle skeleton is obtained, then the mold is opened and the screwdriver handle skeleton is taken out and cooled to set at room temperature; step two, place the cooled and set screwdriver handle skeleton in the soft glue injection mold, together with the pre-set center cavity of the soft glue injection mold to form a soft glue center cavity, then heat and melt the soft glue and inject it into the center cavity, after pressure holding and cooling, the covering layer is formed to obtain the finished product of the screwdriver handle. Through the above steps, the thermoplastic soft glue can be firmly covered on the handle, and it will not slip during use. However, this invention also forms an encapsulation structure through multiple injection molding processes, which lengthens the process cycle, increases the number of material circulation, occupies a large area, and results in a long production cycle, low production efficiency, and difficult quality control. SUMMARY

[0003] The existing multi-layer material injection molding process has a long process flow, multiple material circulation, and large area occupation, which is not conducive to shortening the production cycle and improving the production efficiency, and the quality control is difficult. To overcome these defects, the present application provides a layered injection molding gate device and an injection molding process using the same, which can shorten the production cycle and improve the production efficiency.

[0004] The technical scheme of the present application is a layered injection gate device, comprising a front-stage mold, a lower gate sleeve, a combined gate connected by two gates, an upper gate sleeve and a valve needle, the lower gate sleeve and each gate are hollow structures with a central opening at the bottom, the lower gate sleeve is connected to the bottom opening end of the upper gate sleeve, the combined gate is located in the cavity formed by the cooperation and connection of the upper gate sleeve and the lower gate sleeve and is coaxially nested with the lower gate sleeve, the valve needle is slidably penetrated through the lower gate sleeve, the combined gate and the upper gate sleeve along the axis, the diameter of the valve needle is matched with the diameter of the central opening at the bottom of the lower gate sleeve and each gate, the top end of the valve needle is connected with a valve needle servo drive device, the upper gate sleeve and the combined gate are each provided with a material flow channel, and the output port of the material flow channel is located at the bottom center of the lower gate sleeve and each gate, the front-stage mold comprises a movable mold and a fixed mold, the movable mold is movably connected with the fixed mold, the movable mold is connected with a movable mold servo drive mechanism, the bottom of the lower gate sleeve is embedded in the central cavity of the movable mold, and a central drainage pipe extending into the fixed mold is fixed in the central cavity of the movable mold, and the diameter of the central drainage pipe is matched with the diameter of the central opening at the bottom of the lower gate sleeve and each gate. The layered injection gate device is located between the injection head of the injection molding machine and the product mold. Due to the nested structure between the lower gate sleeve, the upper gate sleeve and the combined gate, and between each gate in the combined gate, the material flow channels on different parts can be independent of each other. During operation of the present application, the injection head injects different materials, such as inner layer material and covering material, into different material flow channels, and the different materials flow along different material flow channels under the driving of injection pressure without interfering with each other. The valve needle servo drive device drives the valve needle to move axially and accurately, and can stop at the central opening at the bottom of any one of the lower gate sleeve, the combined gate and each gate, thereby closing the corresponding material flow channel output port. At the same time, the movable mold also moves under the action of the movable mold servo drive mechanism, driving the central drainage pipe, so that the molten material can be injected out through the material flow channel output port that is not closed, and then output layer by layer through the front-stage mold, and then cooled and formed in the product mold, and finally a product with a multi-layer structure is formed. Using the present application, a qualified multi-layer material product can be produced by one-time online and staged injection molding, without the need for repeated online and offline processing. The original injection molding process can be improved to co-injection sequential control injection molding, thereby significantly shortening the process flow, reducing the occupation of equipment and turnover site, saving the corresponding equipment debugging and material turnover time, and greatly improving the production efficiency. Moreover, since the co-injection sequential control injection molding generates layers with a short interval, the thermal environment temperature fluctuation is relatively smaller, and thus the layer peeling or penetration phenomenon is more easily eliminated.

[0005] As preferred, the movable mold and the fixed mold are connected by threads, the movable mold servo driving mechanism comprises a movable mold outer gear ring, a driving gear and a movable mold driving servo motor, the movable mold outer gear ring is fixed on the outer circumferential surface of the movable mold, the driving gear is connected to the output end of the movable mold driving servo motor, and the movable mold outer gear ring is engaged with the driving gear. Under the driving of the movable mold driving servo motor, the driving gear drives the movable mold outer gear ring, and then drives the whole movable mold to rotate, and the threaded connection structure between the movable mold and the fixed mold converts the rotation of the movable mold into axial movement, so that the central drainage pipe moves and blocks the output port of the material flow channel together with the valve needle.

[0006] Alternatively, the movable mold and the fixed mold are connected by sliding, the movable mold servo driving mechanism comprises at least two electric cylinders, the electric cylinders are parallel to the axis of the movable mold, and the output ends of the electric cylinders are connected to the outer circumferential surface of the movable mold. The electric cylinders can directly drive the movable mold to move axially through extension and retraction, so that the central drainage pipe moves and blocks the output port of the material flow channel together with the valve needle.

[0007] As preferred, the end of the movable mold towards the fixed mold is provided with a central protruding part, and the end surface of the fixed mold is provided with a concave cavity, and the central protruding part is connected to the concave cavity in a matched manner. Threads or sliding surfaces can be arranged on the central protruding part, and matching structures are arranged on the concave cavity correspondingly, so as to realize the movable connection of the movable mold and the fixed mold.

[0008] As preferred, the concave cavity is provided with a central sleeve and a central hole, the lumen of the central sleeve is communicated with the central hole, the central hole is communicated with the central cavity of a product mold, and the central drainage pipe is connected in the central sleeve. The central drainage pipe is a channel for the material to flow and deliver to the product mold, and this structure can ensure that the material can still be continuously output when the movable mold and the fixed mold move relatively.

[0009] As preferred, the combined runner comprises an outer runner and an inner runner, and the outer runner and the inner runner are coaxially nested. The nested outer runner and inner runner form a combined runner with compact structure, the material flow channel arranged on the outer runner is used for the basic structure forming or the innermost layer covering of the product, and the material flow channel arranged on the inner runner is used for the outer layer covering of the product.

[0010] As preferred, the top of the inner runner and the outer runner is provided with a flange, and the top of the upper runner sleeve and the flanges of the inner runner and the outer runner are connected by a positioning pin. The material is input from the outside to the inside, the material flow channel is distributed on different parts, and therefore the relative positions of the parts must be fixed to keep the material flow channels on the parts continuous. The circumferential positioning between the combined runner and the upper runner sleeve can be realized by the positioning pin connection structure, which is simple, compact and easy to implement, and can effectively prevent the material flow channel from being interrupted.

[0011] As preferred, the upper nozzle sleeve is provided with an inner layer material total inlet and an outer layer material total inlet. The inner layer material total inlet and the outer layer material total inlet are directly connected with the injection heads of the injection molding machine outputting various materials, and the various layer materials are guided into the layered injection nozzle device and even the front-stage mold and product mold.

[0012] As preferred, the upper nozzle sleeve is connected with the lower nozzle sleeve through screw connection. The screw connection has simple structure and is convenient to disassemble and assemble.

[0013] A servo-controlled multi-layer material injection molding system forming process using the layered injection nozzle device, comprising the following steps:

[0014] Step one. Connecting the layered injection nozzle device between the injection molding machine and the product mold;

[0015] Step two. Connecting each flow channel in the layered injection nozzle device with the injection head corresponding to each material;

[0016] Step three. Controlling the injection of various materials and the on-off of each flow channel according to the time sequence, and completing the layered injection of various materials.

[0017] Through the above steps, the layered injection of various materials can be completed with high quality and high efficiency.

[0018] The beneficial effects of the present application are:

[0019] The production efficiency is improved. Using the present application, qualified plastic products can be produced by one-time online and phased injection without repeated online and offline processing, which significantly shortens the process flow, saves the corresponding equipment debugging and material turnover time, and greatly improves the production efficiency.

[0020] The quality control is facilitated. The present application precisely controls the opening and closing of the material flow channel outlet through the precise cooperation and movement of the valve needle and the center drainage pipe, thereby effectively avoiding the mutual mixing of materials in different material flow channels.

[0021] The production management is facilitated. The present application can complete the target product in one online production cycle, which can reduce the occupation of equipment and semi-finished products or stage intermediate products turnover site, thereby greatly facilitating production management.

[0022] The product loss is reduced. Since the present application can complete the target product in one online production cycle without producing semi-finished products or stage intermediate products, there is no turnover of semi-finished products or stage intermediate products, thereby eliminating the inevitable loss caused by turnover.

[0023] The operation is economical. The present application can implement co-injection sequential control injection, which can effectively eliminate the interlayer peeling phenomenon, is conducive to the simplification of remedial procedures and the saving of auxiliary consumables, and has better operation economy. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the present application;

[0025] Figure 2 is an exploded view of the parts of the present application;

[0026] Figure 3 is a structural schematic diagram of a movable die servo driving mechanism in the present application.

[0027] In the figure, 1 - pre-stage die, 2 - lower sprue bush, 3 - central cavity, 4 - upper sprue bush, 5 - valve needle, 6 - movable die, 7 - fixed die, 8 - central drainage pipe, 9 - movable die outer gear ring, 10 - driving gear, 11 - movable die driving servo motor, 12 - electric cylinder, 13 - central protrusion, 14 - concave cavity, 15 - central bush, 16 - central hole, 17 - product mold, 17a - bottom die, 17b - mold changing plate, 17c - primary mold, 17d - secondary mold, 17e - tertiary mold, 18 - outer sprue, 19 - inner sprue, 20 - material flow channel output port, 20a - inner layer material output port, 20b - first outer layer material output port, 20c - second outer layer material output port, 21 - inner layer material total inlet, 22 - first outer layer material total inlet, 23 - second outer layer material inlet, 24 - inner layer material inlet, 25 - inner sprue inner layer material outlet, 26 - first outer layer material outlet, 27 - inner sprue outer layer material flow slot, 28 - outer sprue inner layer material outlet, 29 - outer sprue inner layer material flow slot, 30 - inner layer material flow channel, 31 - first outer layer material flow channel, 32 - second outer layer material total inlet, 33 - second outer layer material flow channel. DETAILED DESCRIPTION

[0028] The present application will be further described in connection with the specific embodiments and the accompanying drawings.

[0029] Example 1:

[0030] As Figure 1 , Figure 2The application discloses a layered injection gate device which is used for processing of a screwdriver handle with color matched rubber coating and works under the control of a PLC system. The layered injection gate device comprises a front-stage mold 1, a lower gate sleeve 2, a combined gate formed by two gates, an upper gate sleeve 4 and a valve needle 5. The lower gate sleeve 2, each gate is of a hollow structure and is provided with an opening at the bottom center. The lower gate sleeve 2 is connected to the opening end of the bottom of the upper gate sleeve 4. The combined gate is located in a cavity formed by the cooperation of the upper gate sleeve 4 and the lower gate sleeve 2 and is coaxially nested with the lower gate sleeve 2. The upper gate sleeve 4 is connected with the lower gate sleeve 2 through threads. The combined gate comprises an outer gate 18 and an inner gate 19 which are coaxially nested. The valve needle 5 is slidably penetrated through the lower gate sleeve 2, the combined gate and the upper gate sleeve 4 along an axis. The diameter of the valve needle 5 is matched with the caliber of the opening at the bottom center of the lower gate sleeve 2 and each gate. The top end of the valve needle 5 is connected with a valve needle servo driving device. The valve needle servo driving device comprises a servo motor and a screw rod transmission mechanism. The screw rod transmission mechanism comprises a screw rod and a valve needle fixing block. The screw rod is connected with the servo motor through a shaft coupling. The valve needle fixing block is threadedly connected on the screw rod. The valve needle 5 is fixed on the valve needle fixing block. The upper gate sleeve 4 and the combined gate are both provided with material flow channels, including an inner layer material flow channel 30, a first outer layer material flow channel 31 and a second outer layer material flow channel 33. The second outer layer material flow channel 33 is located in the inner gate 19. The first outer layer material flow channel 31 is located between the outer gate 18 and the inner gate 19. The inner layer material flow channel 30 is located between the outer gate 18 and the lower gate sleeve 2. The terminals of the inner layer material flow channel 30, the first outer layer material flow channel 31 and the second outer layer material flow channel 33 are material flow channel output ports 20 which are located at the bottom center of the lower gate sleeve 2 and each gate. From bottom to top, the material flow channel output ports 20 are respectively an inner layer material output port 20a, a first outer layer material output port 20b and a second outer layer material output port 20c. The top of the inner gate 19 is provided with a first outer layer material inlet, a second outer layer material inlet 23 and an inner layer material inlet 24. The second outer layer material inlet 23 is located at the top center of the inner gate 19. The first outer layer material inlet and the inner layer material inlet 24 are located at the top edge of the inner gate 19 and are opposite to each other. The inner gate 19 is provided with an inner gate inner layer material outlet 25, a first outer layer material outlet 26 and an inner gate outer layer material flow groove 27 on the surface. The first outer layer material outlet 26 is located in the inner gate outer layer material flow groove 27 and is isolated from the inner cavity of the inner gate 19. The first outer layer material outlet 26 is communicated with the first outer layer material flow channel 31 arranged between the inner and outer walls of the inner gate 19. The second outer layer material inlet 23 only communicates with the inner cavity of the inner gate 19. The inner layer material inlet 24 is communicated with the inner gate inner layer material outlet 25 through the first outer layer material flow channel 31 arranged between the inner and outer walls of the inner gate 19. The inner gate outer layer material flow groove 27 is isolated from the inner gate inner layer material outlet 25.The upper gate sleeve 4 is provided with an inner layer material total inlet 21, a first outer layer material total inlet 22 and a second outer layer material total inlet 32. The second outer layer material total inlet 32 is communicated with the second outer layer material inlet 23, the first outer layer material total inlet 22 is communicated with the first outer layer material inlet, and the inner layer material total inlet 21 is communicated with the inner layer material inlet 24. The inner gate outer layer material flow groove 27 is lower than the outer peripheral surface of the inner gate 19, the outer peripheral surface of the inner gate 19 is sealingly attached to the inner wall of the inner cavity of the outer gate 18, and the inner gate inner layer material outlet 25 is located on the outer peripheral surface of the inner gate 19. The outer gate 18 is provided with an outer gate inner layer material outlet 28 and an outer gate inner layer material flow groove 29, the outer gate inner layer material outlet 28 is located in the outer gate inner layer material flow groove 29 and is aligned with the inner gate inner layer material outlet 25, the outer gate inner layer material flow groove 29 is lower than the outer peripheral surface of the outer gate 18, and the outer peripheral surface of the outer gate 18 is sealingly attached to the inner wall of the inner cavity of the lower gate sleeve 2. The front stage mold 1 includes a movable mold 6 and a fixed mold 7. The movable mold 6 is provided with a central protruding part 13 at one end facing the fixed mold 7. The end surface of the fixed mold 7 is provided with a concave cavity 14. The central protruding part 13 is movably connected with the concave cavity 14. The movable mold 6 is connected with a movable mold servo driving mechanism. The concave cavity 14 is provided with a central sleeve 15 and a central hole 16. The lumen of the central sleeve 15 is communicated with the central hole 16. The central hole 16 is communicated with the cavity of a product mold 17. The central drainage pipe 8 is connected in the central sleeve 15. The product mold 17 is a three-color injection mold, which includes a bottom mold 17a, a mold changing plate 17b, a primary mold 17c, a secondary mold 17d and a tertiary mold 17e. The primary mold 17c, the secondary mold 17d and the tertiary mold 17e are both through the two ends, the front end is connected with the fixed mold 7, and the rear end is connected with the bottom mold 17a. The primary mold 17c is used for forming the screwdriver handle body, the secondary mold 17d is used for the first color rubber coating of the screwdriver handle outer layer, and the tertiary mold 17e is used for the second color rubber coating of the screwdriver handle outer layer. The primary mold 17c, the secondary mold 17d and the tertiary mold 17e are uniformly distributed and fixed on the mold changing plate 17b in a regular triangle. The mold changing plate 17b is connected with a replacement motor. The bottom mold 17a and the mold changing plate 17b are arranged on a mold frame. The mold frame is slidingly connected with a group of mold opening and closing guide rods and is driven by a mold opening and closing oil cylinder. The mold frame is further provided with a secondary mold opening and closing mechanism composed of a bottom mold guide rod and a bottom mold driving mechanism, which is used for driving the bottom mold 17a to be connected or disconnected with the primary mold 17c, the secondary mold 17d or the tertiary mold 17e. The bottom of the lower gate sleeve 2 is slidingly embedded in the central cavity 3 of the movable mold 6. A central drainage pipe 8 extending into the fixed mold 7 is fixed in the central cavity 3. The diameter of the central drainage pipe 8 is matched with the diameters of the lower gate sleeve 2 and the central openings of the respective gates. The distance between the bottom end of the valve needle 5 and the top end of the central drainage pipe 8 is equal to the distance between any two adjacent central openings of the lower gate sleeve and the respective gates, so that only one central opening can be accommodated in the space between the bottom end of the valve needle 5 and the top end of the central drainage pipe 8, thereby effectively preventing the materials in the flow channels of different materials from mixing.The movable mold 6 is connected with the fixed mold 7 through thread connection, the movable mold servo driving mechanism comprises a movable mold outer gear ring 9, a driving gear 10 and a movable mold driving servo motor 11, the movable mold outer gear ring 9 is fixed on the outer circumferential surface of the movable mold 6, the driving gear 10 is key connected on the output end of the movable mold driving servo motor 11, and the movable mold outer gear ring 9 is engaged with the driving gear 10. The top of the inner gate 19 and the outer gate 18 is provided with a flange, and the circumferential positioning structure comprises a positioning pin, and the positioning pin penetrates the top of the gate sleeve 4 and the flanges of the inner gate 19 and the outer gate 18.

[0031] A servo control multi-layer material injection molding system forming process using the layered injection gate device, comprising the following steps:

[0032] Step one. Connect the layered injection gate device between the injection molding machine and the product mold 17, and fix and install the screwdriver handle rod in the bottom mold 17a of the product mold 17;

[0033] Step two. The inner layer material total inlet 21, the first outer layer material total inlet 22 and the second outer layer material total inlet 32 are respectively connected with the injection heads of three injection molding machines, so that the inner layer material flow channel 30, the first outer layer material flow channel 31 and the second outer layer material flow channel 33 in the layered injection gate device respectively obtain molten material from the injection heads of the three injection molding machines, and the three injection molding machines respectively output screwdriver handle body material nylon and two kinds of colored encapsulating material silicone.

[0034] Step three. According to the time sequence, the injection of various materials and the on-off control of each flow channel are carried out, and the layered injection of various materials is completed.

[0035] Specifically, in operation, the three injection heads of the three injection molding machines are fed to respectively interface with the inner-layer material general inlet 21, the first outer-layer material general inlet 22 and the second outer-layer material general inlet 32 of the lower-gate sleeve 6, and to respectively inject the molten inner-layer material and outer-layer material. Under the guidance of the inner-layer material runner 30 including the second outer-layer material inlet 23, the inner-gate inner-layer material outlet 25, the outer-gate inner-layer material outlet 28 and other nodes, the inner cavities of the lower-gate sleeve 2 and the inner-gate 19 are filled with the inner-layer material; under the guidance of the first outer-layer material runner 31 including the inner-layer material inlet 24, the first outer-layer material outlet 26 and other nodes, the inner cavity of the outer-gate 18 is filled with the first outer-layer material, and the nested structure of the lower-gate sleeve 2, the outer-gate 18 and the inner-gate 19 makes the respective inner cavities independent of each other, so that the inner-layer material and the outer-layer material flow along the inner-layer material runner 30 and the first outer-layer material runner 31 respectively under the driving of the injection pressure, without interfering with each other.The valve needle servo drive device drives the valve needle 5 to move precisely axially, starting from the center opening at the bottom of the lower sprue sleeve 2, and stopping successively at positions above the center opening at the bottom of the lower sprue sleeve 2, above the center opening at the bottom of the outer sprue 18, and above the center opening at the bottom of the inner sprue 19. Simultaneously, the moving mold 6 also moves under the action of the moving mold servo drive mechanism, driving the central drain pipe 8 to maintain a fixed distance from the end of the valve needle 5. This allows the inner layer material output port 20a, the first outer layer material output port 20b, and the second outer layer material output port 20c to sequentially fall into the gap between the central drain pipe 8 and the valve needle 5, thus allowing the molten material to flow in a set order. The material flow channel outlet 20 is injected and output layer by layer through the central hole 16 of the front mold 1, and then cooled and formed in the primary mold 17c. When the gap between the central drain pipe 8 and the valve needle 5 stops below the inner layer material outlet 20a, all material flow channel outlets are closed and injection molding has not started. Under the control of the PLC, the bottom mold 17a and the primary mold 17c close. The mold frame is driven by the mold opening and closing cylinder, carrying the bottom mold 17a, the changing mold plate 17b, and the primary mold 17c close to the fixed mold 7 until they close with the fixed mold 7. The valve needle 5 and the moving mold 6 move in coordination, and the gap between the central drain pipe 8 and the valve needle 5 stops below the inner layer material outlet 20a. At position a, the injection molding machine for injecting the inner layer material is started, the inner layer material is injected and flows through the lower gating sleeve 2 and the front mold 1 into the primary mold 17c, where it cools and solidifies into the screwdriver handle body. Under the control of the PLC, the mold frame, carrying the bottom mold 17a, the primary mold 17c, and the fixed mold 7, opens. The bottom mold 17a and the primary mold 17c open. The changing mold plate 17b rotates 120° under the drive of the rotating motor. The primary mold 17c moves away, the secondary mold 17d rotates to a position facing the fixed mold 7, and the bottom mold 17a and the secondary mold 17d close. The bottom mold 17a and the secondary mold 17d then close with the fixed mold. The valve needle 5 and the moving mold 6 move in coordination. The gap between the drain tube 8 and the valve needle 5 stops at the first output port 20b of the outer layer material. The injection molding machine, used for injecting the first outer layer material, starts, and the first outer layer material enters the secondary mold 17d through the outer sprue 18 and the front mold 1, where it cools and solidifies into the first color coating on the screwdriver handle body. Similarly, after the bottom mold 17a, the third mold 17e, and the fixed mold 7 are closed, the gap between the central drain tube 8 and the valve needle 5 stops at the second output port 20c of the outer layer material. The second outer layer material is injected and enters the third mold 17e through the inner sprue 19 and the front mold 1, where it cools and solidifies into the second color coating on the screwdriver handle body, forming a color combination with the first color coating. Through the above process, the molten inner layer material, the first outer layer material, and the second outer layer material are output through the unclosed material flow channel output port 20 in a set order and then cooled and solidified layer by layer, ultimately forming a screwdriver with a handle body and a color-blocked coating layer.

[0036] Example 2:

[0037] Two injection molding machines are used. The second outer layer material inlet 32 ​​is blocked and not used, and the third mold 17e is cancelled. The rest is the same as in Example 1.

[0038] This technical solution is used to process single-color rubber-coated handles for screwdrivers, eliminating all operation steps involving injection molding of a second outer layer material.

[0039] Example 3:

[0040] like Figure 3 As shown, the moving mold 6 and the fixed mold 7 are slidably connected. The moving mold servo drive mechanism includes two electric cylinders 12, which are parallel to the axis of the moving mold 6. The output end of the electric cylinder 12 is connected to the connecting seat on the outer circumference of the moving mold 6. The rest is the same as in Embodiment 1.

[0041] Example 4:

[0042] The moving mold servo drive mechanism includes three electric cylinders 12, which are parallel to the axis of the moving mold 6 and evenly distributed around the moving mold 6. The output end of the electric cylinder 12 is connected to the outer peripheral surface of the moving mold 6. The rest is the same as in Embodiment 1.

Claims

1. A layered injection molding runner device, characterized in that: The system includes a pre-mold, a bottom runner sleeve, a combined runner consisting of two connected runners, an upper runner sleeve, and a valve pin. The bottom runner sleeve and each runner are hollow structures with a center opening at the bottom. The bottom runner sleeve connects to the bottom opening of the upper runner sleeve. The combined runner is located within the cavity formed by the upper and lower runner sleeves and is coaxially nested with the bottom runner sleeve. The valve pin slidably passes through the bottom runner sleeve, the combined runner, and the upper runner sleeve along its axis. The diameter of the valve pin is adapted to the diameter of the center opening at the bottom of the bottom of the bottom runner sleeve and each runner. The tip of the valve pin is connected to a valve pin servo. The drive unit is connected, and both the upper sprue sleeve and the combined sprue are equipped with material flow channels. The material flow channel outlets are located at the bottom center of the lower sprue sleeve and each sprue. The front mold includes a moving mold and a fixed mold, which are movably connected. The moving mold is connected to a moving mold servo drive mechanism. The bottom of the lower sprue sleeve is embedded in the central cavity of the moving mold. A central drain pipe extending into the fixed mold is fixed in the central cavity of the moving mold. The diameter of the central drain pipe is adapted to the diameter of the bottom center opening of the lower sprue sleeve and each sprue. The distance between the bottom end of the valve needle and the top end of the central drain pipe is the same as that between the lower sprue sleeve and the lower sprue. The spacing between any two adjacent centers at the bottom of each runner is equal; the moving mold and the fixed mold are connected by threads, and the moving mold servo drive mechanism includes a moving mold external gear ring, a drive gear, and a moving mold drive servo motor. The moving mold external gear ring is fixed on the outer circumferential surface of the moving mold, and the drive gear is connected to the output end of the moving mold drive servo motor. The moving mold external gear ring meshes with the drive gear; or, the moving mold and the fixed mold are slidably connected, and the moving mold servo drive mechanism includes at least two electric cylinders, which are parallel to the axis of the moving mold, and the output end of the electric cylinder is connected to the outer circumferential surface of the moving mold; the moving mold The end facing the fixed mold has a central protrusion, and the end face of the fixed mold has a cavity. The central protrusion is adapted to connect with the cavity. The cavity has a central sleeve and a central hole. The cavity of the central sleeve is connected to the central hole. The central hole can be connected to the cavity of a product mold. The central drain tube is connected inside the central sleeve. The central hole is connected to the cavity of a product mold. The product mold is a three-color injection mold, including a bottom mold, a changing mold plate, a primary mold, a secondary mold, and a tertiary mold. The primary mold, secondary mold, and tertiary mold are all connected at both ends, with the front end connected to the fixed mold and the rear end connected to the bottom mold.

2. The layered injection molding runner device according to claim 1, characterized in that: Both the upper gating sleeve and the combined gating system are provided with material flow channels, including an inner material flow channel, a first outer material flow channel, and a second outer material flow channel. The second outer material flow channel is located inside the inner gating system, the first outer material flow channel is located between the outer gating system and the inner gating system, and the inner material flow channel is located between the outer gating system and the lower gating sleeve.

3. The layered injection molding runner device according to claim 1, characterized in that: The inner material flow channel, the first outer material flow channel, and the second outer material flow channel are all connected to material flow channel outlets. The material flow channel outlets are located at the bottom center of the lower gating sleeve and each gating system. From bottom to top, there are inner material outlets, the first outer material outlet, and the second outer material outlet.

4. The layered injection molding runner device according to claim 1, characterized in that: The combined gating system includes an outer gating system and an inner gating system, which are coaxially nested together.

5. The layered injection molding runner device according to claim 4, characterized in that: Flanges are provided at the top of both the ingate and the gating system, and the flanges of the top of the gating system and the ingate and gating system are connected by locating pins.

6. The layered injection molding runner device according to any one of claims 1 to 5, characterized in that: The top of the upper pouring channel is equipped with an inner material inlet and an outer material inlet channel.

7. The layered injection runner device according to any one of claims 1 to 5, characterized in that... The upper and lower pouring gate sleeves are connected by threads.

8. A molding process for a servo-controlled multi-layer material injection molding system using the layered injection gating device described in claim 1, characterized in that: Includes the following steps: Step 1. Connect the layered injection runner device between the injection molding machine and the product mold; Step 2. Connect each runner in the layered injection molding runner device to the injection head corresponding to each material; Step 3. Inject various materials according to the time sequence and control the on / off state of each flow channel to complete the layered injection molding of various materials.

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