Injection mold for machining rotor of automobile position sensor

Abstract

The utility model discloses an injection mold for processing an automobile position sensor rotor, which comprises an upper fixing plate, a hot runner plate, a front mold plate, a rear mold plate and a lower fixing plate, the hot runner plate and the front mold plate are sequentially and fixedly connected below the upper fixing plate, the rear mold plate is connected onto the lower fixing plate, and a mold core is arranged on a mold closing surface of the front mold plate and the rear mold plate. The mold core comprises a front mold core embedded in the bottom surface of the front mold plate and a rear mold core embedded in the rear mold plate, a row of cavities are arranged between the front mold core and the rear mold core, the cavities are mutually independent, a rotor magnetic steel can be placed in the center of each cavity of the rear mold core, molten plastic is injected from the upper fixing plate, and the rotor magnetic steel is placed in the rear mold core. Molten plastic is poured into the cavity through the hot runner plate, the front mold plate and the front mold core in sequence, the molten plastic is injected into the cavity from the symmetrical positions of the two sides of each rotor magnetic steel, and the rotor magnetic steel is wrapped in the center of the cavity of the rear mold core through the molten plastic; when the mold is used for injection molding, the problem of uneven thickness of rotor shell plastic can be solved, and the processing quality is improved.

Description

Technical Field

[0001] This utility model belongs to the field of injection molding embedding technology for mechanical products, specifically relating to an injection mold used for machining the rotor of an automotive position sensor. Background Technology

[0002] With the intelligent development of modern automobiles, more and more position sensors are being installed in vehicles. The rotor is a key component of these position sensors, used to detect rotational position, such as in throttle position sensors or ABS sensors. Injection molding is a common manufacturing process for rotors. Injection molding improves the structural integrity and insulation performance of the rotor. Compared to metal encapsulation, it also reduces rotor weight, provides better corrosion resistance, extends rotor life, and lowers production costs, making it suitable for mass production. During injection molding, a round magnet is placed into a mold cavity, and molten plastic is injected into the cavity, wrapping the magnet's outer surface. Existing injection molds typically use single-point injection. Because magnets are small and light, the molten plastic impacts them, causing displacement during the pouring process. This results in uneven thickness of the plastic coating around the magnet, with some areas even lacking coverage, leading to product quality fluctuations and a high defect rate. Utility Model Content

[0003] To address the aforementioned problems and technical requirements, this utility model provides an injection mold for machining automotive position sensor rotors. Using this mold for rotor embedding can solve the problem of uneven thickness of the rotor shell plastic, reduce the defect rate, and improve processing quality.

[0004] The technical solution of this utility model is as follows: An injection mold for machining rotors of automotive position sensors includes an upper fixed plate, a hot runner plate, a front mold plate, a rear mold plate, and a lower fixed plate. The hot runner plate and the front mold plate are sequentially fixedly connected below the upper fixed plate, and the rear mold plate is connected to the lower fixed plate. Mold cores are provided on the mating surfaces of the front and rear mold plates. The mold cores include a front mold core embedded in the bottom surface of the front mold plate and a rear mold core embedded in the rear mold plate. A row of cavities is provided between the front and rear mold cores, and the cavities are independent of each other. A rotor magnet can be placed in the center of each cavity of the rear mold core. Molten plastic is injected from the upper fixed plate, and the molten plastic is poured into the cavity sequentially through the hot runner plate, the front mold plate, and the front mold core. The molten plastic is injected into the cavity from symmetrical positions on both sides of each rotor magnet, and the molten plastic surrounds the rotor magnet in the center of the cavity of the rear mold core. This mold can simultaneously perform injection molding on multiple cavities. Each cavity has a symmetrical injection point on both sides, and injection from both sides improves injection stability and avoids voids and uneven thickness during injection molding.

[0005] Furthermore, the upper section of the cavity is a disc shape to accommodate the rotor magnet, the middle section of the cavity is cylindrical, and the lower section of the cavity is screw-shaped; a tunnel slide is provided in the rear mold core, and two tunnel slides are symmetrically embedded into the rear mold core from both sides. The tunnel slides can move laterally relative to the rear mold core. The front end face of the tunnel slide is provided with a semi-circular thread. The front end faces of the two tunnel slides are joined together to form a cylindrical thread surface, which is used for the forming of the lower section of the cavity.

[0006] Furthermore, the tunnel section divides the rear mold core into an upper rear mold core and a lower rear mold core. The middle and upper sections of the cavity are located in the upper rear mold core, and a vertical forming rod is embedded in the middle of the lower rear mold core, with the top of the forming rod extending upward into the bottom of the cavity.

[0007] Furthermore, the cylindrical cavity inside the upper rear mold core is provided with a magnetic positioning insert on its peripheral wall. The magnetic positioning insert is connected inside the upper rear mold core and supports the rotor magnet from the bottom. The tunnel slide is located below the magnetic positioning insert, so that the bottom surface of the rotor magnet is suspended above the top circular hole of the cylindrical cavity.

[0008] Furthermore, each side of the rotor magnet is provided with a positioning groove, which can cooperate with the magnet positioning insert to fix the rotor magnet in the cavity. The positioning groove can improve the positioning stability of the rotor magnet, improve the injection molding accuracy, and make the thickness of the plastic layer covering the rotor magnet more uniform.

[0009] Furthermore, a circular positioning protrusion is provided in the center of the cavity within the front mold core. The rotor magnet is annular, and in the mold-closed state, the circular positioning protrusion can be inserted into the center of the rotor magnet from the top. The circular positioning protrusion facilitates the forming of the top of the cavity and also provides a positioning effect for the rotor magnet.

[0010] Furthermore, the rear mold plate has two rows of ejector pins symmetrically arranged inside, with each row corresponding to a row of cavities. The bottom of the ejector pins is connected to a lower fixing plate, and the ejector pins pass through the rear mold plate and the rear mold core. The injection molded part in each cavity is ejected from the cavity by the ejector pins on both sides, with the tips of the two ejector pins aligned with the sprue channels on both sides of the cavity. Using a symmetrical injection method from both sides avoids single-point injection causing impact displacement of the rotor magnets, thus improving the injection precision of the finished product.

[0011] The beneficial effects of this utility model are as follows: 1) This mold has a sprue runner on each side of the cavity. During injection molding, the molten plastic can be injected into the cavity simultaneously through two symmetrical points. For the rotor magnet placed in the cavity, the force on both sides can avoid displacement during the injection process, making the thickness of the injection molded part of the rotor magnet shell uniform and the finished product high precision; 2) The rear mold core adopts a multi-layer mold core design, including upper and lower rear mold cores and a tunnel slide in the middle. After the tunnel slide pulls the core to both sides, the injection molded part is ejected upwards and demolded, which can solve the demolding problem of the screw threads at the tail end of the injection molded part. In addition, the magnet positioning insert is connected to the upper rear mold core. The magnet positioning insert and the tunnel slide are staggered to avoid interference with the magnet positioning insert when pulling the core outwards. Attached Figure Description

[0012] Figure 1 This is an external structural diagram of the injection mold of this utility model;

[0013] Figure 2 This is a cross-sectional structural diagram of the injection mold of this utility model;

[0014] Figure 3 This is a cross-sectional view of the internal structure of the mold core in the injection mold of this utility model;

[0015] Figure 4 This is a top view of the interior of the rear template of the injection mold of this utility model;

[0016] Figure 5 This is a diagram showing the positional relationship between the rear mold core and the lower fixed plate in the injection mold of this utility model;

[0017] Figure 6 This is a diagram showing the fit between the tunnel slide and the cavity in the injection mold of this utility model;

[0018] Figure 7 This diagram illustrates the relationship between the magnetic positioning insert and the tunnel movement in the injection mold of this utility model.

[0019] Figure 8 This is a structural diagram of the outer injection molded part of the rotor magnet in the injection mold of this utility model;

[0020] Figure 9 This is a diagram showing the positional relationship between the rotor magnet and the tunnel traveler in the injection mold of this utility model;

[0021] The components in the diagram are labeled as follows: Upper fixed plate 1, hot runner plate 2, front template 3, front mold core 4, circular positioning protrusion 41, rotor magnet 5, positioning groove 51, sprue runner 6, rear mold core 7, upper rear mold core 71, cavity 711, magnet positioning insert 712, tunnel slide 72, thread 721, lower rear mold core 73, forming rod 731, rear template 8, ejector pin 81, and lower fixed plate 9. Detailed Implementation

[0022] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0023] like Figure 1-9 The figure shows an injection mold for machining a rotor of an automotive position sensor according to the present invention. It includes an upper fixed plate 1, a hot runner plate 2, a front mold plate 3, a rear mold plate 8, and a lower fixed plate 9. The hot runner plate 2 and the front mold plate 3 are fixedly connected to the lower part of the upper fixed plate 1. The rear mold plate 8 is connected to the lower fixed plate 9. Mold cores are provided on the mating surfaces of the front mold plate 3 and the rear mold plate 8. The mold cores include a front mold core 4 embedded on the bottom surface of the front mold plate and a rear mold core 7 embedded on the rear mold plate 8. A row of cavities 711 is provided between the front mold core 4 and the rear mold core 7. The cavities 711 are independent of each other. A rotor magnet 5 can be placed in the center of each cavity 711 of the rear mold core 7. Molten plastic is injected from the upper fixed plate 1. The molten plastic is poured into the cavity 711 through the hot runner plate 2, the front mold plate 3, and the front mold core 4 in sequence. The molten plastic is injected into the cavity 711 from symmetrical positions on both sides of each rotor magnet 5. The molten plastic wraps the rotor magnet 5 in the center of the cavity of the rear mold core 7.

[0024] The upper section of the cavity is disc-shaped to accommodate the rotor magnet, the middle section is cylindrical, and the lower section is screw-shaped. The rear mold core 7 is provided with tunnel slides 72. Two tunnel slides 72 are symmetrically embedded into the rear mold core 8 from both sides. The tunnel slides 72 can move laterally relative to the rear mold core 7. The front end face of the tunnel slides 72 is provided with semi-circular threads 721. The front end faces of the two tunnel slides 72 are joined together to form a cylindrical threaded surface. The threaded surface is used for forming the lower section of the cavity 711.

[0025] The cylindrical cavity within the upper rear mold core 71 is provided with a magnetic positioning insert 712 on its peripheral wall. The magnetic positioning insert 712 is connected within the upper rear mold core 71 and supports the rotor magnet 5 from the bottom. The tunnel slide 72 is located below the magnetic positioning insert 712, causing the bottom surface of the rotor magnet 5 to suspend above the top circular hole of the cylindrical cavity. A positioning groove 51 is provided on each side of the rotor magnet 5. The positioning groove 51 cooperates with the magnetic positioning insert 712 to fix the rotor magnet 5 within the cavity 711. The positioning groove 51 improves the positioning stability of the rotor magnet 5, increases injection molding accuracy, and makes the thickness of the plastic layer covering the rotor magnet more uniform.

[0026] A circular positioning protrusion 41 is provided in the center of the cavity within the front mold core 4. The rotor magnet 5 is annular. In the mold-closed state, the circular positioning protrusion 41 can be embedded into the center of the rotor magnet 5 from the top. The circular positioning protrusion 41 facilitates the forming of the top of the cavity and also has a positioning effect on the rotor magnet 5. The tunnel slide 72 divides the rear mold core 7 into an upper rear mold core 71 and a lower rear mold core 73. The middle and upper sections of the cavity are located in the upper rear mold core 71. A vertical forming rod 731 is embedded in the center of the lower rear mold core 73, and the top of the forming rod 731 extends upward into the bottom of the cavity 711.

[0027] This mold can simultaneously injection mold multiple cavities. Each cavity has a symmetrical injection point on both sides, allowing for simultaneous injection from both sides, improving injection stability and preventing voids and uneven thickness during molding. Two rows of ejector pins 81 are symmetrically arranged within the rear mold plate 8, corresponding one-to-one with a row of cavities 711. The bottom of each ejector pin 81 is connected to the lower fixing plate 9, and the ejector pins 81 pass through the rear mold plate 8 and the rear mold core 7. The injection molded part in each cavity 711 is ejected from the cavity by the ejector pins 81 on both sides. The tips of the two ejector pins 81 are aligned with the sprue channels 6 on both sides of the cavity. This symmetrical injection method avoids impact displacement of the rotor magnet 5 caused by single-point injection, improving the injection accuracy of the finished product.

[0028] The injection molding process of this utility model is as follows: Molten plastic is injected into the middle of the upper fixed plate 1. The molten plastic is injected into the front mold core 4 through the hot runner plate 2 and the front template 3. The molten plastic is poured into the entire row of cavities at one time. The rotor magnet 5 is fixedly placed on the magnet positioning insert 712 in the center of the cavity. The molten plastic flows into the cavity 711 from the sprue channels 6 on both sides of each rotor magnet 5, embedding the rotor magnet 5 inside. The screw is cast below the rotor magnet 5. After cooling, demolding is performed. The tunnel slides 72 on both sides are pulled out to both sides first, so that the screw thread 721 is demolded. After the screw thread is demolded, the front mold core 4 and the rear mold core 7 are opened. Then the rear template 8 is pressed down, and the ejector pin 81 is ejected from the rear mold core 7. The ejector pin 81 pushes the entire row of rotor magnet injection molded parts upward through the injection areas of the sprue channels 6 on both sides.

[0029] The above descriptions are merely several preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations and substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. An injection mold for processing a rotor of an automotive position sensor, characterized in that: The upper fixed plate is sequentially fixedly connected with the hot runner plate and the front mold plate below, the lower fixed plate is connected with the rear mold plate, the mold closing surface of the front mold plate and the rear mold plate is provided with a mold core, the mold core comprises a front mold core embedded in the bottom surface of the front mold plate and a rear mold core embedded in the rear mold plate, a row of cavities is arranged between the front mold core and the rear mold core, the cavities are independent of each other, and the center of each cavity of the rear mold core can accommodate a rotor magnetic steel; molten plastic is injected from the upper fixed plate, and the molten plastic is sequentially injected into the cavities through the hot runner plate, the front mold plate and the front mold core; the molten plastic is symmetrically injected into the cavities from the two sides of each rotor magnetic steel, and the molten plastic wraps the rotor magnetic steel in the center of the cavity of the rear mold core.

2. The injection mold for the rotor machining of an automotive position sensor according to claim 1, characterized in that: The upper section of the cavity is disc-shaped and used for accommodating the rotor magnetic steel, the middle section of the cavity is cylindrical, and the lower section of the cavity is screw-shaped; the rear mold core is provided with two tunnel rows, the two tunnel rows are symmetrically embedded in the rear mold core from the two sides, the tunnel rows can move transversely relative to the rear mold core, the front end surface of the tunnel rows is provided with a semicircular screw thread, the front end surfaces of the two tunnel rows are spliced to form a cylindrical screw thread surface, and the screw thread surface is used for molding the lower section of the cavity.

3. The injection mold for the rotor machining of an automotive position sensor according to claim 2, characterized in that: The tunnel rows divide the rear mold core into an upper rear mold core and a lower rear mold core, the middle section and the upper section of the cavity are located in the upper rear mold core, and a vertical molding rod is embedded in the middle of the lower rear mold core and extends upward into the bottom of the cavity.

4. The injection mold for machining of an automotive position sensor rotor according to claim 3, characterized in that: The circumferential wall of the cylindrical cavity in the upper rear mold core is provided with a magnetic steel positioning insert, the magnetic steel positioning insert is connected in the upper rear mold core, the magnetic steel positioning insert supports the rotor magnetic steel from the bottom, and the tunnel rows are located below the magnetic steel positioning insert, so that the bottom surface of the rotor magnetic steel is suspended above the top circular hole of the cylindrical cavity.

5. The injection mold for the rotor machining of an automotive position sensor according to claim 4, characterized in that: Each side of the rotor magnetic steel is provided with a positioning groove, the positioning groove can cooperate with the magnetic steel positioning insert to fix the rotor magnetic steel in the cavity.

6. The injection mold for the rotor of an automotive position sensor according to claim 5, characterized in that: The middle part of the cavity in the front mold core is provided with a circular positioning protrusion, the rotor magnetic steel is annular, and in the mold closing state, the circular positioning protrusion can be embedded in the center of the rotor magnetic steel from the top.

7. The injection mold for the rotor of an automotive position sensor according to claim 6, characterized in that: The rear mold plate is symmetrically provided with two rows of ejector pins, the two rows of ejector pins correspond to the row of cavities one by one, the bottom of the ejector pin is connected with the lower fixed plate, the ejector pin penetrates through the rear mold plate and the rear mold core, and the injection molded part in each cavity is ejected from the cavity by the ejector pins on the two sides; the top ends of the two ejector pins are respectively aligned with the gate runners on the two sides of the cavity.

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