Magnetic attraction magnetic ring injection mold

Abstract

A mold core assembly is arranged on the outer side of a sprue bush of a fixed mold assembly, the mold core assembly and a movable mold assembly are matched to form a magnetic ring forming cavity, meanwhile, a pouring channel is formed in the sprue bush, and the pouring channel extends outwards to form an inner diameter side pouring channel connected with the inner side end of the magnetic ring forming cavity. The inner diameter side of the magnetic ring forms a pouring gate, and no pouring gate imprint is left on the two surfaces of the molded magnetic ring; a push plate is arranged above the magnetic ring forming cavity, a pull rod connected with the push plate is arranged in the movable mold assembly and connected with a material pulling pin of a pouring channel, the material pulling pin can pull out water gap materials in the pouring channel and the inner diameter side pouring channel, the pull rod can drive the push plate to move towards the movable mold assembly, the whole plane of the push plate acts on a magnetic ring, and the magnetic ring is driven to move synchronously to be taken out. The forming quality is good, the pouring gate and the ejector pin demolding imprint are not left, therefore, the surface integrity of the magnetic ring is guaranteed, and the magnetic field intensity and the distribution uniformity are improved.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic ring injection molding and magnetization, in particular to a magnetic attraction magnetic ring injection molding mold. Background Art

[0002] The magnetic ring injection molding process is a molding process in which permanent magnetic materials are injected into a mold for shaping. The injection mold is usually provided with an oriented magnetic circuit. During the magnetic ring molding process, the magnetic ring is magnetized so that the molded magnetic ring has a magnetic field.

[0003] For example, a Chinese patent with announcement number CN 208681984 U discloses an anisotropically oriented magnetic circuit mold, which consists of a movable mold and a fixed mold. The fixed mold includes a fixed mold bottom plate and a fixed mold plate, and a fixed mold core is arranged in the fixed mold plate. The movable mold includes a movable mold pad and a movable mold plate 1 and a movable mold plate 2 arranged above the movable mold pad from top to bottom. A movable mold small core is longitudinally passed through the middle of the movable mold plate 1 and the movable mold plate 2. The outer side of the movable mold small core in the movable mold plate 1 is the product, and the outer side of the product is the movable mold outer circular core. The outer side of the movable mold small core in the movable mold plate 2 is the movable mold large core. The bottom of the movable mold pad is connected to the movable mold bottom plate through a pad, a push plate is provided above the movable mold bottom plate, and a push rod is provided above the push plate.

[0004] However, existing injection molds usually pour gates on both sides of the magnetic ring and directly apply ejector pins to the magnetic ring, resulting in gate and ejector pin demolding marks on both sides of the molded magnetic ring, which not only affects the appearance quality of the magnetic ring, but also causes local deformation of the surface of the magnetic ring, thereby affecting the uniformity of the magnetic field distribution and the magnetic field strength of the magnetic ring.

[0005] Therefore, how to effectively improve the appearance quality of the magnetic ring after injection molding and ensure the uniformity of the magnetic field distribution and the magnetic field strength of the magnetic ring has become an urgent problem to be solved in this field. Summary of the invention

[0006] In view of the defects of the prior art, the purpose of the present invention is to provide a magnetic ring injection mold with good magnetic ring molding quality, uniform magnetic field distribution and high magnetic field intensity.

[0007] In order to achieve the above-mentioned purpose, the magnetic ring injection mold provided by the present invention comprises a fixed mold component and a movable mold component arranged at the bottom of the fixed mold component.

[0008] The fixed mold assembly is provided with a sprue sleeve, and a core assembly is provided outside the sprue sleeve. The core assembly cooperates with the movable mold assembly to form a magnetic ring molding cavity, and a push plate is arranged above the magnetic ring molding cavity.

[0009] A pouring channel is formed in the gate sleeve, and the pouring channel extends outward to form an inner diameter side pouring channel connected to the inner side end of the magnetic ring forming cavity.

[0010] An orientation magnetic circuit is provided in the movable mold assembly, and a pull rod connected to the push plate and a pull pin connected to the pouring channel are provided in the orientation magnetic circuit.

[0011] Furthermore, the pouring channel, the inner diameter side pouring channel and the magnetic ring molding cavity are filled with anisotropic injection-molded permanent magnetic material.

[0012] Furthermore, the fixed mold assembly includes a panel and a fixed mold plate arranged below the panel, one end of the sprue sleeve is arranged in the panel, and the other end is arranged in the fixed mold plate.

[0013] Furthermore, the mold core assembly is arranged in the fixed mold plate, including a mold core and a mold core sleeve arranged outside the mold core, and the push plate is arranged between the mold core and the mold core sleeve.

[0014] Furthermore, the side end of the mold core that cooperates with the magnetic ring molding cavity forms an extrusion surface, and the extrusion surface extends toward the movable mold assembly.

[0015] Furthermore, the movable mold assembly includes a movable mold plate and a movable mold plate gasket arranged below the movable mold plate, the orientation magnetic circuit is arranged in the movable mold plate, and the pull rod and the pulling pin pass through the movable mold plate gasket and the movable mold plate to respectively connect the push plate and the pouring channel.

[0016] Furthermore, the orientation magnetic circuit is arranged below the magnetic ring forming cavity, is distributed concentrically with the magnetic ring forming cavity, and is configured to be distributed in a circular ring shape.

[0017] Furthermore, the oriented magnetic circuit has a plurality of holes evenly distributed along the circumference, and each hole is composed of 5 pieces of magnetic steel arranged from the center to the outer circumference and distributed in a circular Halbach array.

[0018] Furthermore, the third magnetic steel corresponding to the middle area of ​​the magnetic ring forming cavity is configured to have a trapezoidal cross-section, and the width of the top surface close to the magnetic ring forming cavity is smaller than the width of the bottom surface away from the magnetic ring forming cavity.

[0019] Furthermore, the second magnetic steel and the fourth magnetic steel distributed on both sides of the third magnetic steel are configured to form a symmetrical trapezoidal cross section, and cooperate with the third magnetic steel to form a rectangular cross section.

[0020] The magnetic attraction magnetic ring injection mold provided by the present invention has a core assembly provided on the outer side of the gate sleeve of the fixed mold assembly, and the core assembly cooperates with the movable mold assembly to form a magnetic ring molding cavity. At the same time, a pouring channel is formed in the gate sleeve, and the pouring channel extends outward to form an inner diameter side pouring channel connected to the inner side end of the magnetic ring molding cavity, so that the injection molded permanent magnetic material in the gate sleeve will flow along the pouring channel to the inner diameter side pouring channels on both sides, and then enter the magnetic ring molding cavity from the inner side end of the magnetic ring molding cavity, thereby realizing the molding of the magnetic ring in the magnetic ring molding cavity, and forming a pouring gate on the inner diameter side of the magnetic ring, and no gate imprint will be left on both sides of the molded magnetic ring.

[0021] Furthermore, a push plate is arranged above the magnetic ring molding cavity, and an orientation magnetic circuit for magnetizing the magnetic ring is provided in the movable mold assembly. A pull rod connecting the push plate is provided in the orientation magnetic circuit, and a pulling pin connected to the pouring channel is connected to the pull pin. After the magnetic ring is formed, the pulling pin can pull out excess injection molding permanent magnetic material in the pouring channel and the inner diameter side pouring channel. At this time, the pull rod is pulled, and the pull rod can drive the push plate to move toward the movable mold assembly, so that the overall plane of the push plate acts on the magnetic ring, driving the magnetic ring to move synchronously and be taken out, so that no ejector demolding mark is formed on both sides of the magnetic ring.

[0022] Therefore, the appearance quality of the magnetic ring after molding is better, and no gate and ejector demoulding marks are left, thereby ensuring the surface integrity of the magnetic ring and improving the magnetic field strength and magnetic field distribution uniformity of the magnetic ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] Figure 1 This is a schematic diagram of the overall structure of the magnetic ring injection mold provided by the present invention;

[0025] Figure 2 A schematic diagram of the molding of the magnetic attraction magnetic ring injection mold provided by the present invention;

[0026] Figure 3 A schematic diagram of demoulding of the magnetic ring injection mold provided by the present invention;

[0027] Figure 4 and Figure 5 Schematic diagram of the distribution structure of the oriented magnetic circuit in the present invention;

[0028] Figure 6 Schematic diagram of magnetic field distribution of the magnetic ring in the present invention;

[0029] Figure 7 and Figure 8 A schematic diagram comparing the inner side end inlet of the present invention with the existing inlet method;

[0030] Figures 9 to 12 It is a schematic diagram comparing the oriented magnetic circuit of the present invention and the existing oriented magnetic circuit.

[0031] For the present invention

[0032] Reference numerals:

[0033] 100. Fixed mold assembly; 101. Panel; 102. Fixed mold plate; 110. Gate sleeve; 111. Inlet channel; 112. Inner diameter side inlet channel; 120. Core assembly; 121. Core; 122. Core sleeve; 123. Extrusion surface; 130. Push plate; 131. Moving plate; 132. Stripper plate; 140. Positioning ring;

[0034] 200. Moving mold assembly; 201. Moving mold plate; 202. Moving mold plate gasket; 210. Oriented magnetic circuit; 211. Hole; 212. First magnetic steel; 213. Second magnetic steel; 214. Third magnetic steel; 215. Fourth magnetic steel; 216. Fifth magnetic steel; 220. Pull rod; 230. Pull pin;

[0035] 300. Magnetic ring forming cavity; 400. Magnetic ring; 410. Magnetic surface; 420. Non-magnetic surface; 430. Non-magnetic area; 500. Water inlet material. DETAILED DESCRIPTION

[0036] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0037] See also Figure 1 , which shows an example of the magnetic attraction magnetic ring injection mold provided by the present invention.

[0038] As can be seen from the figure, the magnetic ring injection mold of this example mainly includes a fixed mold component 100 and a movable mold component 200 arranged at the bottom of the fixed mold component 100.

[0039] A gate sleeve 110 is provided in the fixed mold assembly 100, and a core assembly 120 is provided on the outside of the gate sleeve 110. The core assembly 120 cooperates with the movable mold assembly 200 to form a magnetic ring molding cavity 300. A push plate 130 is arranged above the magnetic ring molding cavity 300. At the same time, a pouring channel 111 is formed in the gate sleeve 110, and the pouring channel 111 extends outward to form an inner diameter side pouring channel 112 connected to the inner end of the magnetic ring molding cavity 300, so that the injection molded permanent magnet material in the gate sleeve 110 enters the inner diameter side pouring channel 112 along the pouring channel 111, enters the magnetic ring molding cavity 300 from the inner end of the magnetic ring molding cavity 300, realizes the molding of the magnetic ring 400 in the magnetic ring molding cavity 300, and forms a gate on the inner diameter side of the magnetic ring 400, so that no gate mark will be left on both sides of the molded magnetic ring.

[0040] Furthermore, an orientation magnetic circuit 210 is provided in the movable mold assembly 200, and a pull rod 220 connected to the push plate 130 and a pulling pin 230 connected to the pouring channel 111 are provided in the orientation magnetic circuit 210, so that after the magnetic ring is formed, the excess injection permanent magnetic material in the pouring channel 111 and the inner diameter side pouring channel 112, that is, the sprue material 500 can be pulled out through the pulling pin 230, and by pulling the pull rod 220, the push plate 130 can be driven to move toward the movable mold assembly 200, so that the entire plane of the push plate 130 acts on the magnetic ring 400, driving the magnetic ring 400 to move synchronously and be taken out, so that no ejector demolding marks are formed on both sides of the magnetic ring.

[0041] Therefore, the appearance quality of the magnetic ring 400 after molding is good, and no gate and ejector demoulding marks are left, thereby ensuring the surface integrity of the magnetic ring and improving the magnetic field strength and magnetic field distribution uniformity of the magnetic ring.

[0042] Among them, the fixed mold assembly 100 includes a panel 101 and a fixed mold plate 102 arranged below the panel 101. A positioning ring 140 is provided on the panel 101. The positioning ring 140 is used to connect with the nozzle of the injection molding machine, so that the injection mold can be accurately docked with the injection molding machine, so that the injection molding machine can quickly and accurately pour the injection molding permanent magnet material into the injection mold.

[0043] In coordination therewith, one end of the sprue sleeve 110 is arranged in the panel 101 and connected to the positioning ring 140, and the other end is arranged in the fixed mold plate 102, and cooperates with the core assembly 120 arranged in the fixed mold plate 102, so that the injection-molded permanent magnetic material is poured into the sprue sleeve 110, and is formed into a magnetic ring 400 in the core assembly 120 through the sprue sleeve 110.

[0044] Combination Figure 2 Furthermore, the core assembly 120 includes a core 121 and a core sleeve 122, the core 121 is arranged on the outside of the gate sleeve 110, and the core sleeve 122 is arranged on the outside of the core 121, so that the gate sleeve 110, the core 121 and the core sleeve 122 cooperate with each other to realize the flow and molding of the injection molded permanent magnetic material.

[0045] Specifically, the mold core 121 is configured as a T-shaped cylinder, and the mold sleeve 122 is configured as a circular cylinder with a diameter larger than the lower area of ​​the mold core 121, and is concentrically distributed with the mold core 121, and is sleeved on the outside of the mold core 121, so that a magnetic ring molding cavity 300 is formed between the outer wall of the mold core 121, the inner wall of the mold sleeve 122 and the movable mold assembly 200.

[0046] In order to cast the permanent magnetic material into the magnetic ring molding cavity 300, a cavity capable of accommodating the gate sleeve 110 is formed in the mold core 121, so that the gate sleeve 110 can be built into the mold core 121. At the same time, a pouring channel 111 is formed in the gate sleeve 110, and a gap is provided between the bottom of the mold core 121 and the movable mold assembly 200, so that the lower area of ​​the pouring channel 111 can extend along the outside to form an inner diameter side pouring channel 112 in the gap between the bottom of the mold core 121 and the movable mold assembly 200, and the inner diameter side pouring channel 112 is formed in the inner diameter side. The channel 112 is connected to the inner end of the magnetic ring molding cavity 300, so that the injection molded permanent magnetic material enters the inlet channel 111 of the gate sleeve 110, flows along the flow channel of the inlet channel 111, and flows to both sides into the inner diameter side inlet channel 112, and then enters the magnetic ring molding cavity 300 from the inner end of the magnetic ring molding cavity 300, and is finally formed into a magnetic ring 400 in the magnetic ring molding cavity 300. At the same time, the excess injection molded permanent magnetic material in the inlet channel 111 and the inner diameter side inlet channel 112 forms a sprue material 500.

[0047] Thus, the injection molded permanent magnet material enters the inner end of the magnetic ring molding cavity 300 from the inner diameter side inlet channel 112, forming an inlet gate on the inner diameter side of the magnetic ring, so that no gate marks are left on both sides of the molded magnetic ring 400, thereby ensuring the molding quality of the magnetic ring 400.

[0048] Furthermore, a plurality of inner diameter side pouring channels 112 are evenly distributed along the circumference of the magnetic ring molding cavity 300, and are respectively connected to the inner ends of the magnetic ring molding cavity 300 to form a plurality of pouring gates at the inner end of the magnetic ring molding cavity 300, so that the injection-molded permanent magnetic material can synchronously enter the plurality of inner diameter side pouring channels 112 from the pouring channel 111, and then synchronously enter the magnetic ring molding cavity 300 from the plurality of pouring gates at the inner end, thereby improving the uniformity of the distribution of the injection-molded permanent magnetic material in the magnetic ring molding cavity 300, ensuring the molding quality of the magnetic ring, and also improving the pouring efficiency, reducing the heat loss of the injection-molded permanent magnetic material during the pouring process, and ensuring that the molded magnetic ring can be effectively magnetized.

[0049] Combination Figure 2 In order to further improve the uniformity of the distribution of the injection molded permanent magnetic material in the magnetic ring molding cavity 300, an extrusion surface 123 is formed on the side end of the mold core 121 that cooperates with the magnetic ring molding cavity 300. The extrusion surface 123 extends toward the movable mold assembly 200, so that the extrusion surface 123 forms a beveled surface. When the injection molded permanent magnetic material enters the magnetic ring molding cavity 300 from the inner diameter side inlet channel 112, the extrusion surface 123 can effectively reduce the flow resistance of the injection molded permanent magnetic material, so that the injection molded permanent magnetic material can flow more smoothly into the magnetic ring molding cavity 300, thereby improving the extrusion speed and efficiency of the injection mold.

[0050] At the same time, the beveled surface structure of the extrusion surface 123 can also separate the molded magnetic ring 400 in the magnetic ring molding cavity 300 from the excess sprue material 500 in the inner diameter side inlet channel 112 and the inlet channel 111, so that the magnetic ring 400 can be more easily separated from the mold core 121, reducing the risk of damage to the magnetic ring 400 during the demolding process.

[0051] Furthermore, a push plate 130 is also provided in the fixed mold plate 102. The push plate 130 is arranged between the mold core 121 and the mold core sleeve 122, and is composed of a T-shaped movable plate 131 and a stripping plate 132. The stripping plate 132 is placed above the magnetic ring molding cavity 300 and is composed of a flat panel adapted to the magnetic ring 400. The movable plate 131 is placed on the outside of the magnetic ring molding cavity 300 and is connected to the pull rod 220 in the movable mold assembly 200, so that when the push plate 130 moves in the magnetic ring molding cavity 300 facing the movable mold assembly 200, the stripping plate 132 can act on the surface of the magnetic ring 400 of the magnetic ring molding cavity 300 in an overall plane, drive the magnetic ring 400 to move synchronously toward the movable mold assembly 200, and be detached and taken out from the mold core assembly 120, so that no mark is produced on the surface of the magnetic ring 400, thereby ensuring the molding quality of the magnetic ring 400.

[0052] At the same time, the push plate 130 is placed above the magnetic ring molding cavity 300, which can also limit the pouring height of the injection molded permanent magnetic material in the magnetic ring molding cavity 300, thereby ensuring the molding accuracy of the magnetic ring 400. By adjusting the height of the push plate 130, the molding height of the magnetic ring 400 can be adjusted.

[0053] Combination Figure 1 In order to enable the push plate 130 to move stably in the magnetic ring molding cavity 300, the movable mold assembly 200 includes a movable mold plate 201 and a movable mold plate gasket 202. The movable mold plate 201 is configured to be able to move relative to the fixed mold plate 102, so that the movable mold plate 201 can be closed with the fixed mold plate 102, and cooperate with the core assembly 120 in the fixed mold plate 102 to form the magnetic ring molding cavity 300, ensuring the molding of the magnetic ring 400, and can also be separated from the fixed mold plate 102, which is convenient for demolding the magnetic ring 400 and the sprue material 500.

[0054] The movable mold assembly 200 also includes a movable mold plate gasket 202 disposed below the movable mold plate 201. The movable mold plate gasket 202 is configured to adjust the height and levelness of the movable mold plate 201 to ensure that the parallelism and gap between the movable mold plate 201 and the fixed mold plate 202 are uniform, so as to improve the molding accuracy and surface quality of the magnetic ring 400.

[0055] Furthermore, a pull rod 220 and a pull pin 230 are provided in the movable mold assembly 200, and the pull rod 220 and the pull pin 230 respectively pass through the movable mold plate gasket 202 and the movable mold plate 201, and are respectively connected to the push plate 130 and the pouring channel 111, so that after the movable mold plate 201 is separated from the fixed mold plate 102, the pull rod 220 and the pull pin 230 can respectively drive the magnetic ring 400 and the sprue material 500 to fall off from the core mold assembly 120.

[0056] Combination Figure 3 Specifically, the pulling pin 230 is connected to the pouring channel 111. When the injection-molded permanent magnetic material enters the pouring channel 111, part of the injection-molded permanent magnetic material will adhere to the pulling pin 230, so that the pulling pin 230 can be connected to the sprue material 500 formed in the pouring channel 111 and the inner diameter side pouring channel 112. When the pulling pin 230 is pulled to move toward the movable template 201, the pulling pin 230 can drive the sprue material 500 to move synchronously toward the movable template 201.

[0057] At this time, since the sprue material 500 is separated from the magnetic ring 400 by the bevel surface formed by the extrusion surface 123, the sprue material 500 can fall off from the inlet channel 111 and the inner diameter side inlet channel 112 driven by the pulling pin 230, leaving the magnetic ring 400 in the magnetic ring molding cavity 300.

[0058] Furthermore, the pull rod 220 is connected to the movable plate 131 of the push plate 130, so that when the pull rod 220 is pulled to move toward the movable template 201, the pull rod 220 will drive the movable plate 131 to move synchronously toward the movable template 201, thereby driving the overall plane of the stripping template 132 to act on the magnetic ring 400, driving the magnetic ring 400 to move synchronously toward the movable template 201 and fall off from the core assembly 120, so that the magnetic ring 400 can be taken out without forming a stripping mark on the surface of the magnetic ring 400, thereby ensuring the molding quality.

[0059] In order to magnetize the magnetic ring 400 during the molding process of the magnetic ring 400, an orientation magnetic circuit 210 is provided in the movable template 201. The orientation magnetic circuit 210 is arranged below the magnetic ring molding cavity 300, is concentrically distributed with the magnetic ring molding cavity 300, and is configured in a circular ring shape, so that the orientation magnetic circuit 210 is adapted to the magnetic ring 400 and can magnetize the magnetic ring 400.

[0060] Combination Figure 4Furthermore, the oriented magnetic circuit 210 has a plurality of holes 211 evenly distributed along the circumference, and each hole 211 is composed of 5 magnetic steels arranged along the direction from the center of the circle to the outer circumference, and distributed in a circular Halbach array, so as to improve the utilization rate of the injection molded permanent magnetic material, and at the same time, the first magnetic steel 212, the second magnetic steel 213, the third magnetic steel 214, the fourth magnetic steel 215 and the fifth magnetic steel 216 in each hole 211 are concentrically distributed trapezoidal magnetic steels, and the width gradually increases, thereby forming a uniformly distributed magnetic circuit, which can perform single-sided two-pole magnetization on the magnetic ring 400.

[0061] Combination Figure 5 Furthermore, the third magnetic steel 214 corresponds to the middle area of ​​the magnetic ring forming cavity 300 and is configured into a trapezoidal cross-section, and the width of the top surface close to the magnetic ring forming cavity 300 is smaller than the width of the bottom surface away from the magnetic ring forming cavity 300, so that the non-magnetic area 430 of the magnetic ring 400 is narrower, thereby ensuring the magnetic field strength of the magnetic ring 400.

[0062] In coordination therewith, the second magnetic steel 213 and the fourth magnetic steel 215 distributed on both sides of the third magnetic steel 214 are configured into a symmetrical trapezoidal cross section, and cooperate with the third magnetic steel 214 to form a rectangular cross section, so that the magnetic ring 400 forms a uniform magnetic field distribution.

[0063] Combination Figure 6 The oriented magnetic circuit 210 thus formed can form a magnetic circuit with uniform distribution and high strength, so that the single-sided bipolar magnetic field formed by the magnetization of the magnetic ring 400 forms a magnetic surface 410 on the side away from the oriented magnetic circuit 210, and forms a non-magnetic surface 420 on the side close to the oriented magnetic circuit 210. At the same time, two poles with opposite magnetic properties are formed in the outer ring and the inner ring, and a narrow non-magnetic zone 430 is formed between the outer ring and the inner ring, so that the magnetic field has a larger magnetic attraction, which can effectively improve the utilization rate of injection molded permanent magnet materials.

[0064] Preferably, the injection-molded permanent magnet material is composed of anisotropic injection-molded permanent magnet material, for example, anisotropic injection-molded NdFeB magnets, so as to improve the orientation degree of the magnet 400 , and improve the magnetic field strength and material utilization rate.

[0065] The following examples illustrate the working process of the present invention in a specific application. It should be noted that the following content is only a specific application example of the present solution and does not constitute a limitation to the present solution.

[0066] Combination Figure 1 and Figure 2First, connect the positioning ring 140 of the fixed mold assembly 100 to the nozzle of the injection molding machine, and close the movable mold assembly 200 and the fixed mold assembly 100, and pour the anisotropic injection molding permanent magnetic material into the inlet channel 111 of the gate sleeve 110, so that the anisotropic injection molding permanent magnetic material flows along the flow channel of the inlet channel 111 and flows to both sides into the inner diameter side inlet channel 112, and then enters the magnetic ring molding cavity 300 from the inner end of the magnetic ring molding cavity 300, and is formed into a magnetic ring 400 in the magnetic ring molding cavity 300, and the excess anisotropic injection molding permanent magnetic material in the inlet channel 111 and the inner diameter side inlet channel 112 forms a sprue material 500.

[0067] Combination Figure 7 and Figure 8 In this example, eight inner diameter side pouring channels 112 are evenly distributed along the circumference of the magnetic ring molding cavity 300, and eight pouring gates are formed at the inner end of the magnetic ring molding cavity 300. Compared with the existing injection mold that pours at the top of the magnetic ring molding cavity 300, the use of the inner end pouring gate can effectively improve the pouring efficiency. Compared with the existing pouring method, it can shorten the pouring time by 0.22s, which is 17.7%. Therefore, the temperature loss during the filling process of the anisotropic injection molding permanent magnet material can be greatly reduced, which is beneficial to the orientation of the magnetic ring 400.

[0068] Thus, the anisotropic injection-molded permanent magnet material enters the inner end of the magnetic ring molding cavity 300 from the inner diameter side inlet channel 112, forming an inlet gate on the inner diameter side of the magnetic ring. No gate marks will be left on both sides of the molded magnetic ring 400, thereby ensuring the molding quality of the magnetic ring 400.

[0069] Combination Figure 4 Furthermore, the orientation magnetic circuit 210 in the moving template 201 magnetizes the magnetic ring 400 below the magnetic ring 400, and the orientation magnetic circuit 210 has 30 holes 211 evenly distributed along the circumference, and each hole 211 is composed of 5 pieces of magnetic steel arranged from the center to the outer circumference, and distributed in a circular Halbach array.

[0070] At the same time, combined Figure 5 The third magnetic steel 214 corresponding to the middle area of ​​the magnetic ring forming cavity 300 is configured to have a trapezoidal cross-section, and the width of the top surface close to the magnetic ring forming cavity 300 is smaller than the width of the bottom surface away from the magnetic ring forming cavity 300, so that the non-magnetic area 430 of the magnetic ring 400 is narrower, so that the magnetic ring 400 forms a single-sided bipolar magnetic field with relatively strong and uniform distribution, and a magnetic surface 410 is formed on the side away from the oriented magnetic circuit 210, and a non-magnetic surface 420 is formed on the side close to the oriented magnetic circuit 210. At the same time, two poles with opposite magnetic properties are formed on the outer ring and the inner ring, and a narrow non-magnetic area 430 is formed between the outer ring and the inner ring.

[0071] Combination Figures 9 to 12Compared with the existing oriented magnetic circuit with a wider non-magnetic area, the magnetic field strength formed by the oriented magnetic circuit 210 of the present invention is 5500Gs, which is 1.04 times that of the existing oriented magnetic circuit.

[0072] Therefore, the magnetic field strength of the magnetic ring 400 is relatively large, and can be used in scenarios with relatively large magnetic attraction, such as magnetic wireless charging of mobile phones.

[0073] Combination Figure 3 , further, the movable mold assembly 200 is separated from the fixed mold assembly 100, and the pulling pin 230 is pulled to move toward the movable mold plate 201, so as to drive the nozzle material 500 to move synchronously toward the movable mold plate 201, fall off from the inlet channel 111 and the inner diameter side inlet channel 112, and separate from the magnetic ring 400 through the extrusion surface 123, leaving the magnetic ring 400 in the magnetic ring molding cavity 300.

[0074] Next, when the pull rod 220 is pulled to move toward the movable template 201, the movable plate 131 is driven to move synchronously toward the movable template 201, thereby driving the overall plane of the stripping template 132 to act on the magnetic ring 400, driving the magnetic ring 400 to move synchronously toward the movable template 201, and falling off from the core assembly 120. The magnetic ring 400 is taken out without forming a demolding mark on the surface of the magnetic ring 400, thereby ensuring the molding quality, thereby further ensuring the uniformity of the magnetic field distribution and the magnetic field strength.

[0075] The magnetic attraction magnetic ring injection mold provided by the present invention cooperates with the gate sleeve 110 and the core assembly 120 in the fixed mold assembly 100 and the oriented magnetic circuit 210, the pull rod 220 and the pulling pin 230 in the movable mold assembly 200, so that the molded magnetic ring 400 will not form gate and ejector demolding marks on both sides, thereby ensuring the molding quality, and also has a single-sided bipolar magnetic field with relatively high strength and uniform distribution.

[0076] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A magnetic ring injection mold, comprising a fixed mold assembly and a movable mold assembly arranged at the bottom of the fixed mold assembly, characterized in that: The fixed mold assembly is provided with a sprue sleeve, and a core assembly is provided outside the sprue sleeve. The core assembly cooperates with the movable mold assembly to form a magnetic ring molding cavity, and a push plate is arranged above the magnetic ring molding cavity. A pouring channel is formed in the gate sleeve, and the pouring channel extends outward to form an inner diameter side pouring channel connected to the inner side end of the magnetic ring forming cavity. An orientation magnetic circuit is provided in the movable mold assembly, and a pull rod connected to the push plate and a pull pin connected to the pouring channel are provided in the orientation magnetic circuit.

2. The magnetic ring injection mold according to claim 1, characterized in that: The pouring channel, the inner diameter side pouring channel and the magnetic ring forming cavity are filled with anisotropic injection-molded permanent magnetic material.

3. The magnetic ring injection mold according to claim 1, characterized in that: The fixed mold assembly includes a panel and a fixed mold plate arranged below the panel, one end of the sprue sleeve is arranged in the panel, and the other end is arranged in the fixed mold plate.

4. The magnetic ring injection mold according to claim 3, characterized in that: The mold core assembly is arranged in the fixed mold plate, and comprises a mold core and a mold core sleeve arranged outside the mold core, and the push plate is arranged between the mold core and the mold core sleeve.

5. The magnetic ring injection mold according to claim 4, characterized in that: The side end of the mold core that cooperates with the magnetic ring molding cavity forms an extrusion surface, and the extrusion surface extends toward the movable mold assembly.

6. The magnetic ring injection mold according to claim 1, characterized in that: The movable mold assembly includes a movable mold plate and a movable mold plate gasket arranged below the movable mold plate, the oriented magnetic circuit is arranged in the movable mold plate, and the pull rod and the pulling pin pass through the movable mold plate gasket and the movable mold plate to respectively connect the push plate and the pouring channel.

7. The magnetic ring injection mold according to claim 1, characterized in that: The oriented magnetic circuit is arranged below the magnetic ring forming cavity, is distributed concentrically with the magnetic ring forming cavity, and is configured to be distributed in a circular ring shape.

8. The magnetic ring injection mold according to claim 7, characterized in that: The oriented magnetic circuit has a plurality of holes evenly distributed along the circumference, and each hole is composed of 5 pieces of magnetic steel arranged from the center of the circle to the outer circumference and distributed in a circular Halbach array.

9. The magnetic ring injection mold according to claim 8, characterized in that: The third magnetic steel corresponding to the middle area of ​​the magnetic ring forming cavity is configured to have a trapezoidal cross-section, and the width of the top surface close to the magnetic ring forming cavity is smaller than the width of the bottom surface away from the magnetic ring forming cavity.

10. The magnetic ring injection mold according to claim 9, characterized in that: The second magnetic steel and the fourth magnetic steel distributed on both sides of the third magnetic steel are configured to form a symmetrical trapezoidal cross section, and cooperate with the third magnetic steel to form a rectangular cross section.

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