High-precision back-extrusion flow-limiting die

Abstract

The utility model discloses a high-precision back-extrusion flow-limiting mould which comprises a pouring system, the pouring system comprises a main runner and a branch runner arranged on the lower portion of the outer side of the main runner, and a flow metering mechanism is arranged at the end, away from the main runner, of the branch runner. The plastic melt flow is accurately measured through the ultrasonic flowmeter, when the flow is abnormal, the electromagnetic valve can rapidly adjust the opening degree of the valve to conduct flow limiting control, the defects of short shooting, flash, sink marks and the like of products are effectively reduced, the size precision and surface quality of the products are improved, and the melt flow stability is ensured to improve the qualification rate and consistency; the combination of the ultrasonic flow meter and the electromagnetic valve can quickly respond to flow change to realize real-time flow-limiting adjustment, so that the injection molding process is more stable, the production interruption and adjustment time are reduced, and meanwhile, accurate flow control can optimize injection molding process parameters, improve the melt filling speed and cooling efficiency, shorten the injection molding period and improve the production efficiency; and the production cost is obviously reduced in large-scale production.

Description

Technical Field

[0001] The utility model relates to the technical field of back-extrusion current limiting dies, in particular to a high-precision back-extrusion current limiting die. Background Art

[0002] With the continuous development of the injection molding industry, the requirements for the quality and precision of injection molded products are getting higher and higher. During the injection molding process, the flow control of the plastic melt is crucial to the quality of the product.

[0003] Traditional injection molds usually use simple runner structures, which make it difficult to accurately control the flow of the melt, easily leading to defects in the product, such as short shots, flash, sink marks, etc.; at the same time, traditional flow control methods have slow response speeds and cannot adjust the flow in real time, making it difficult to meet the requirements of high-precision injection molding.

[0004] To this end, we propose a high-precision back-extrusion current limiting die. Utility Model Content

[0005] The main purpose of the present utility model is to provide a high-precision back-extrusion flow limiting mold to prevent defects such as short shots, flash, shrinkage marks, etc. in injection molded products, and to solve the problem that traditional flow control methods have slow response speed and cannot adjust the flow in real time, thereby improving the quality and precision of injection molded products, meeting the requirements of high-precision injection molding, and effectively solving the problems in the background technology.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A high-precision back-extrusion flow-limiting die, comprising a pouring system, the pouring system comprising a main channel and a branch channel provided at the lower outer portion of the main channel, a flow metering mechanism provided at one end of the branch channel away from the main channel, and a flow limiting mechanism provided at one end of the flow metering mechanism away from the branch channel;

[0008] The flow metering mechanism includes an ultrasonic flow meter body, and both ends of the ultrasonic flow meter body are provided with a first flange;

[0009] The flow limiting mechanism includes a solenoid valve body, and both ends of the solenoid valve body are provided with a second flange.

[0010] By adopting the above technical solution, when the injection molding machine starts working, the plastic melt is ejected from the injection molding machine nozzle and first enters the main channel of the mold. The main channel serves as the main channel for the melt to enter the mold and guides the melt to the branch channel at the lower outer side.

[0011] After the melt enters the diverter channel, it continues to flow to the flow metering mechanism. The ultrasonic flowmeter body in the flow metering mechanism starts to work. The ultrasonic flowmeter uses the relationship between the propagation speed of ultrasonic waves in the fluid and the fluid flow rate to measure the flow rate. When the plastic melt flows through the ultrasonic flowmeter body, the propagation time of ultrasonic waves in the melt will change. By measuring the propagation time difference of ultrasonic waves in the downstream and upstream directions, the flow rate of the melt can be calculated, and then the flow rate can be obtained. The first flanges at both ends of the ultrasonic flowmeter body are used to connect with the diverter channel and the flow limiting mechanism to ensure that the melt can pass through the flow metering mechanism smoothly and at the same time ensure the sealing of the connection;

[0012] After flow measurement, the plastic melt flows into the flow limiting mechanism. The solenoid valve body in the flow limiting mechanism performs flow limiting control according to the preset flow parameters. When the flow measured by the ultrasonic flowmeter exceeds the set value, the solenoid valve body can reduce the flow of the melt by adjusting the valve opening to achieve the purpose of flow limiting. The second flanges at both ends of the solenoid valve body are used to connect with the flow metering mechanism and the subsequent mold cavity to ensure the sealing and stability of the melt during the flow limiting process.

[0013] Through the design of this high-precision back-extrusion flow-limiting mold, the flow rate of plastic melt can be accurately measured and controlled, thereby improving the quality and production efficiency of injection molded products; at the same time, the combined use of ultrasonic flowmeter and solenoid valve can quickly respond to flow changes and realize real-time flow-limiting adjustment to meet the requirements of high-precision injection molding.

[0014] Furthermore, a nozzle is provided at the top end of the main channel, and a cooling well is provided at the bottom end of the main channel.

[0015] By adopting the above technical solution, the gate is located at the top of the main channel and is the entrance for the plastic melt to enter the mold casting system. It is directly connected to the nozzle of the injection molding machine. The shape and size of the gate are usually designed to better guide the plastic melt into the main channel, reduce splashing and turbulence when the melt enters the mold, and enable the melt to flow smoothly into the mold. At the same time, the size of the gate can affect the injection speed of the plastic melt. A smaller gate can reduce the injection speed, which helps to reduce the shear stress and thermal stress generated by the melt in the mold, thereby improving the quality of the product.

[0016] The cooling well is located at the bottom of the main channel, close to the entrance of the branch channel. It can store cold materials. During the injection molding process, the plastic melt will produce front cold materials at the beginning of injection. The temperature of these cold materials is low and the fluidity is poor. The cooling well can store these cold materials to prevent them from entering the branch channel and the mold cavity, thereby avoiding affecting the quality of the product; secondly, the cooling well can play a certain buffering role, so that the plastic melt can be more evenly distributed before entering the branch channel, which helps to improve the flow balance of the melt in the branch channel and the mold cavity, and reduce the possibility of defects in the product; in addition, the cooling well can also be connected to the cooling system of the mold to help the plastic melt in the main channel cool faster, shorten the injection molding cycle, and improve production efficiency.

[0017] Furthermore, one of the first flanges is fixedly connected to one end of the branch channel, and another of the first flanges is fixedly connected to one of the second flanges.

[0018] By adopting the above technical solution, this connection method enables the plastic melt to flow smoothly from the branch channel into the ultrasonic flowmeter body of the flow metering mechanism. The fixed connection between the first flange and the second flange ensures the sealing and stability of the connection, preventing the plastic melt from leaking during the flow process; at the same time, this connection method is also easy to install and disassemble, and facilitates the maintenance and replacement of the flow metering mechanism and the flow limiting mechanism.

[0019] Furthermore, one end of another second flange is fixedly connected to a branch channel.

[0020] By adopting the above technical solution, such a structure enables the plastic melt that has passed through the flow limiting mechanism to continue to flow through the branch channel. The branch channel serves to transport the melt that has passed the flow limiting control to the mold cavity. The fixed connection between the second flange and the branch channel ensures the firmness and sealing of the connection, ensuring that the melt will not leak during the flow process. This connection method also facilitates the assembly and disassembly of the mold, and is convenient for maintenance and inspection of various parts of the mold.

[0021] Furthermore, a gate is provided at the bottom end of the branch channel.

[0022] By adopting the above technical solution, the plastic melt passes through the branch channel and enters the mold cavity through the gate. It can control the speed and flow of the plastic melt entering the cavity and affect the molding quality of the product.

[0023] Furthermore, a bell mouth is provided at the bottom end of the gate.

[0024] By adopting the above technical solution, firstly, the bell mouth can guide the plastic melt, which can make the plastic melt flow more smoothly from the gate into the mold cavity, reduce the resistance and turbulence of the melt during the flow process, thereby improving the filling effect of the melt and the molding quality;

[0025] Secondly, the bell mouth helps to expand the outlet area of ​​the gate, so that the melt can be more evenly distributed into the mold cavity, which can reduce the possibility of local defects in the product, such as short shot, sink mark, etc.

[0026] In addition, the shape design of the bell mouth can also affect the flow rate and pressure distribution of the melt. By reasonably adjusting the angle and size of the bell mouth, the flow characteristics of the melt can be controlled to meet the molding requirements of different products.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The utility model relates to a high-precision back-extrusion flow-limiting mold. The high-precision back-extrusion flow-limiting mold accurately measures the flow of the plastic melt through an ultrasonic flow meter, and can promptly detect abnormal flow conditions. When the flow exceeds the set value, the solenoid valve can quickly adjust the valve opening to perform flow limiting control, ensuring that the melt enters the mold cavity at an appropriate flow rate. This can effectively reduce the possibility of defects such as short shots, flash, and shrinkage marks on the product, and improve the dimensional accuracy and surface quality of the product. When producing injection molded products with extremely high quality requirements such as precision electronic component housings, the mold can ensure the stability of the melt flow, thereby improving the qualified rate and consistency of the product.

[0029] (2) The utility model provides a high-precision back-extrusion flow-limiting mold. The combined use of an ultrasonic flow meter and a solenoid valve can quickly respond to flow changes and realize real-time flow-limiting adjustment, which makes the injection molding process more stable and reduces production interruptions and adjustment time caused by unstable flow. At the same time, precise flow control can optimize the injection molding process parameters, increase the filling speed and cooling efficiency of the melt, thereby shortening the injection molding cycle and improving production efficiency. In large-scale production, the mold can significantly improve production efficiency and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the pouring system structure of a high-precision back-extrusion current limiting mold of the utility model.

[0031] Figure 2 This is a schematic structural diagram of the flow metering mechanism of a high-precision back-extrusion flow limiting die of the utility model.

[0032] Figure 3 This is a schematic structural diagram of the current limiting mechanism of a high-precision back-extrusion current limiting die of the utility model.

[0033] In the figure: 1. Main channel; 2. Branch channel; 3. Flow metering mechanism; 4. Flow limiting mechanism; 5. Ultrasonic flowmeter body; 6. Solenoid valve body; 7. First flange; 8. Second flange; 9. Inlet; 10. Cooling well; 11. Branch channel; 12. Gate; 13. Bell mouth; 14. Pouring system. DETAILED DESCRIPTION

[0034] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0035] In order to prevent defects such as short shot, flash, shrinkage and so on in injection molded products, and solve the problem of slow response speed and inability to adjust flow in real time of traditional flow control methods, thereby improving the quality and precision of injection molded products and meeting the requirements of high-precision injection molding, such as Figure 1 、 Figure 2 、 Figure 3 As shown, a high-precision back-extrusion flow-limiting mold includes a pouring system 14, the pouring system 14 includes a main channel 1 and a branch channel 2 provided at the lower outer portion of the main channel 1, a flow metering mechanism 3 is provided at one end of the branch channel 2 away from the main channel 1, and a flow limiting mechanism 4 is provided at one end of the flow metering mechanism 3 away from the branch channel 2;

[0036] The flow meter mechanism 3 includes an ultrasonic flow meter body 5 , and both ends of the ultrasonic flow meter body 5 are provided with a first flange 7 ;

[0037] The flow limiting mechanism 4 includes a solenoid valve body 6 , and second flanges 8 are provided at both ends of the solenoid valve body 6 .

[0038] When the injection molding machine starts working, the plastic melt is ejected from the injection molding machine nozzle and first enters the main channel 1 of the mold. The main channel 1 serves as the main channel for the melt to enter the mold and guides the melt to the branch channel 2 at the lower outer side.

[0039] After the melt enters the branch channel 2, it continues to flow to the flow metering mechanism 3, and the ultrasonic flowmeter body 5 in the flow metering mechanism 3 starts to work. The ultrasonic flowmeter uses the relationship between the propagation speed of ultrasonic waves in the fluid and the fluid flow rate to measure the flow rate. When the plastic melt flows through the ultrasonic flowmeter body 5, the propagation time of the ultrasonic wave in the melt will change. By measuring the propagation time difference of the ultrasonic wave in the downstream and upstream directions, the flow rate of the melt can be calculated, and then the flow rate can be obtained. The first flanges 7 at both ends of the ultrasonic flowmeter body 5 are used to connect with the branch channel 2 and the flow limiting mechanism 4 to ensure that the melt can pass through the flow metering mechanism 3 smoothly, while ensuring the sealing of the connection;

[0040] After flow measurement, the plastic melt flows into the flow limiting mechanism 4. The solenoid valve body 6 in the flow limiting mechanism 4 performs flow limiting control according to the preset flow parameters. When the flow measured by the ultrasonic flowmeter exceeds the set value, the solenoid valve body 6 can reduce the flow of the melt by adjusting the valve opening to achieve the purpose of flow limiting. The second flanges 8 at both ends of the solenoid valve body 6 are used to connect with the flow metering mechanism 3 and the subsequent mold cavity to ensure the sealing and stability of the melt during the flow limiting process.

[0041] Through the design of this high-precision back-extrusion flow-limiting mold, the flow rate of plastic melt can be accurately measured and controlled, thereby improving the quality and production efficiency of injection molded products; at the same time, the combined use of ultrasonic flowmeter and solenoid valve can quickly respond to flow changes and realize real-time flow-limiting adjustment to meet the requirements of high-precision injection molding.

[0042] For example, Figure 1 As shown, the present invention further includes that a nozzle 9 is provided at the top end of the main channel 1 , and a cooling well 10 is provided at the bottom end of the main channel 1 .

[0043] When in use, the sprue 9 is located at the top of the main channel 1. It is the entrance for the plastic melt to enter the mold casting system and is directly connected to the nozzle of the injection molding machine. The shape and size of the sprue 9 are usually designed to better guide the plastic melt into the main channel 1, reduce splashing and turbulence of the melt when entering the mold, and enable the melt to flow smoothly into the mold. At the same time, the size of the sprue 9 can affect the injection speed of the plastic melt. A smaller sprue 9 can reduce the injection speed, which helps to reduce the shear stress and thermal stress generated by the melt in the mold, thereby improving the quality of the product.

[0044] The cooling well 10 is located at the bottom end of the main channel 1, close to the entrance of the branch channel 2. It can store cold materials. During the injection molding process, the plastic melt will produce front cold materials at the beginning of injection. The temperature of these cold materials is low and the fluidity is poor. The cooling well 10 can store these cold materials to prevent them from entering the branch channel 2 and the mold cavity, thereby avoiding affecting the quality of the product; secondly, the cooling well 10 can play a certain buffering role, so that the plastic melt can be more evenly distributed before entering the branch channel 2, which helps to improve the flow balance of the melt in the branch channel 2 and the mold cavity, and reduce the possibility of defects in the product; in addition, the cooling well 10 can also be connected to the cooling system of the mold to help the plastic melt in the main channel 1 cool faster, shorten the injection molding cycle, and improve production efficiency.

[0045] For example, Figure 1 As shown, the present invention further includes: one of the first flanges 7 is fixedly connected to one end of the branch channel 2 , and another of the first flanges 7 is fixedly connected to one of the second flanges 8 .

[0046] When in use, this connection method allows the plastic melt to flow smoothly from the branch channel 2 into the ultrasonic flowmeter body 5 of the flow metering mechanism 3. The fixed connection between the first flange 7 and the second flange 8 ensures the sealing and stability of the connection, preventing the plastic melt from leaking during the flow process; at the same time, this connection method is also easy to install and disassemble, and facilitates the maintenance and replacement of the flow metering mechanism 3 and the flow limiting mechanism 4.

[0047] For example, Figure 1 As shown, the present invention further includes that one end of another second flange 8 is fixedly connected to a branch channel 11 .

[0048] When in use, such a structure enables the plastic melt that has passed through the flow limiting mechanism 4 to continue to flow through the branch channel 11. The branch channel 11 serves to transport the melt that has passed the flow limiting control to the mold cavity. The fixed connection between the second flange 8 and the branch channel 11 ensures the firmness and sealing of the connection, ensuring that the melt will not leak during the flow process. This connection method also facilitates the assembly and disassembly of the mold, and is convenient for maintenance and inspection of various parts of the mold.

[0049] For example, Figure 1 As shown, the present invention further includes that a gate 12 is provided at the bottom end of the branch channel 11 .

[0050] When in use, the plastic melt passes through the branch channel 11 and enters the mold cavity through the gate 12. It can control the speed and flow rate of the plastic melt entering the cavity, affecting the molding quality of the product.

[0051] For example, Figure 1 As shown, the present invention further includes that a bell mouth 13 is provided at the bottom end of the gate 12 .

[0052] When in use, first, the bell mouth 13 can play a role in guiding the plastic melt, which can make the plastic melt flow more smoothly from the gate 12 into the mold cavity, reducing the resistance and turbulence of the melt during the flow process, thereby improving the filling effect of the melt and the molding quality;

[0053] Secondly, the bell mouth 13 helps to expand the outlet area of ​​the gate 12, so that the melt can be more evenly distributed into the mold cavity, which can reduce the possibility of local defects in the product, such as short shot, sink mark, etc.

[0054] In addition, the shape design of the bell mouth 13 can also affect the flow rate and pressure distribution of the melt. By reasonably adjusting the angle and size of the bell mouth 13, the flow characteristics of the melt can be controlled to meet the molding requirements of different products.

[0055] It should be noted that the utility model is a high-precision back-extrusion flow-limiting mold, in which one of the first flanges 7 is fixedly connected to one end of the branch channel 2, and the other first flange 7 is fixedly connected to one of the second flanges 8 to ensure the sealing and stability of the connection. One end of the other second flange 8 is fixedly connected to the branch channel 11 to ensure that the melt does not leak during the flow process. The mold is installed on the injection molding machine, and the nozzle of the injection molding machine is connected to the injection port 9 at the top of the main channel 1. The cooling system of the mold is checked and debugged to ensure that the cooling well 10 can work normally and is well connected to the cooling system of the mold, which can help the plastic melt in the main channel 1 to cool faster. The flow metering mechanism 3 and the flow limiting mechanism 4 are debugged, and the measurement parameters of the ultrasonic flowmeter body 5 and the flow limiting parameters of the solenoid valve body 6 are set. According to the specific requirements of the injection molded products and process conditions, the appropriate flow measurement range and flow limiting value are determined;

[0056] Start the injection molding machine, the plastic melt is ejected from the injection molding machine nozzle, and first enters the main channel 1 of the mold. The nozzle 9 guides the plastic melt to flow smoothly into the main channel 1, reducing the splashing and turbulence of the melt when entering the mold. The main channel 1 guides the melt to the branch channel 2 at the lower part of the outer side. After the melt enters the branch channel 2, it continues to flow to the flow metering mechanism 3. The ultrasonic flowmeter body 5 in the flow metering mechanism 3 starts to work, using ultrasonic waves to measure the flow rate and flow of the melt. After the flow metering, the plastic melt flows into the flow limiting mechanism 4. When the ultrasonic flowmeter measures When the flow rate exceeds the set value, the solenoid valve body 6 reduces the flow rate of the melt by adjusting the valve opening to achieve the purpose of flow limiting. The plastic melt controlled by flow limiting continues to flow through the branch channel 11. After passing through the branch channel 11, the plastic melt enters the mold cavity through the gate 12. The gate 12 controls the speed and flow rate of the plastic melt entering the cavity to ensure the molding quality of the product. The bell mouth 13 at the bottom end of the gate 12 guides the plastic melt to flow into the mold cavity more smoothly, reduces resistance and turbulence, and makes the melt more evenly distributed in the mold cavity.

[0057] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A high-precision back-extrusion current limiting mold, comprising a pouring system (14), characterized in that: The pouring system (14) comprises a main flow channel (1) and a branch flow channel (2) provided at the lower outer portion of the main flow channel (1); a flow metering mechanism (3) is provided at one end of the branch flow channel (2) away from the main flow channel (1); and a flow limiting mechanism (4) is provided at one end of the flow metering mechanism (3) away from the branch flow channel (2); The flow metering mechanism (3) comprises an ultrasonic flow meter body (5), and both ends of the ultrasonic flow meter body (5) are provided with a first flange (7); The flow limiting mechanism (4) comprises a solenoid valve body (6), and both ends of the solenoid valve body (6) are provided with a second flange (8).

2. A high-precision back-extrusion current limiting die according to claim 1, characterized in that: A nozzle (9) is provided at the top end of the main channel (1), and a cooling well (10) is provided at the bottom end of the main channel (1).

3. The high-precision back-extrusion current limiting die according to claim 1, characterized in that: One of the first flanges (7) is fixedly connected to one end of the branch channel (2), and the other of the first flanges (7) is fixedly connected to one of the second flanges (8).

4. The high-precision back-extrusion current limiting die according to claim 1, characterized in that: One end of the other second flange (8) is fixedly connected to a branch channel (11).

5. The high-precision back-extrusion current limiting die according to claim 4, characterized in that: A gate (12) is provided at the bottom end of the branch channel (11).

6. A high-precision back-extrusion current limiting die according to claim 5, characterized in that: The bottom end of the gate (12) is provided with a bell mouth (13).

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