Injection Mold for Integrated Molding Current Sensor and Preparation Method

Abstract

The present invention provides an injection mold and a preparation method for an integrally formed current sensor, belonging to the technical field of sensors, including: an upper mold assembly, including an upper mold base, an upper template connected to the upper mold base through fasteners, and an upper mold cavity provided on the upper template, and a first exhaust channel communicated with the upper mold cavity; a lower mold assembly, including a lower mold base, a lower template connected to the lower mold base through fasteners, and a lower mold cavity provided on the lower template, and a glue inlet channel communicated with the upper mold cavity and the lower mold cavity; a carrier, internally provided with a cavity for placing the internal module of the sensor, and sliders for clamping the internal module of the sensor placed in the cavity are arranged on both sides of the cavity, and a second exhaust channel communicated with the cavity. The present invention realizes the encapsulation of the integrally formed current sensor through the injection mold, and can realize the encapsulation of different types of sensors by replacing the carrier.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensors, and relates to an injection mold, in particular to an injection mold for integrally forming a current sensor and a preparation method thereof. Background Art

[0002] With the advancement of the cost reduction and efficiency improvement strategy in the domestic manufacturing environment, the traditional design concept of current sensors has been difficult to meet the requirements of cost reduction and efficiency improvement. Traditional current sensors are based on different principles, and there are certain differences in the internal structure of the products, but basically they are all composed of an internal PCBA, an induction device, an external housing, potting glue, etc. The products with such a structure composition have a mature technical design scheme, a stable process route, and good consistency.

[0003] Since the existing sensors all have an external housing, when assembling the entire sensor, the basic assembly process is based on the external housing, and then other components of the sensor are installed in the external housing one by one, and then potting and encapsulation are carried out. There will be the following problems. First, the assembly process is relatively complex. If misassembly or missing assembly occurs, it needs to be reassembled, which takes a long time. Second, the busbar is a component used to conduct electricity among the sensor components. Generally, it is arranged in a U-shaped structure. When it is installed in the housing, it needs to be bent twice to complete the installation. Third, potting and encapsulation are prone to generating internal stress, which affects the accuracy of the sensor during use. In addition, it will also cause the situation of encapsulation cracking. Summary of the Invention

[0004] The purpose of the present invention is to propose an injection mold that can be used to realize the integral molding of a current sensor in view of the above problems existing in the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions: An injection mold for integrally forming a current sensor, comprising:

[0006] An upper mold assembly, including an upper mold base, an upper template connected to the upper mold base by fasteners, an upper mold cavity provided on the upper template, and a first exhaust channel communicated with the upper mold cavity;

[0007] A lower mold assembly, including a lower mold base, a lower template connected to the lower mold base by fasteners, a lower mold cavity provided on the lower template, and a glue inlet channel communicated with the upper mold cavity and the lower mold cavity;

[0008] A carrier, which has a cavity for placing the internal module of the sensor, and on both sides of the cavity, there are sliders for clamping the internal module of the sensor placed in the cavity, and a second exhaust channel communicated with the cavity. Among them, on the carrier, there is a first positioning structure for limiting the horizontal movement of the internal module of the sensor in the cavity, and a second positioning structure for limiting the horizontal movement of the slider.

[0009] Among them, when the upper mold and the lower mold are clamped, the degrees of freedom of the slider and the carrier moving perpendicular to the demolding direction of the carrier are limited by the third positioning structure on the upper mold, and the degree of freedom of the carrier moving along its demolding direction during the integrated molding stage of the sensor is limited by the fourth positioning structure on the upper mold.

[0010] In the injection mold for the integrated molding current sensor described above, the first positioning structure includes one or more of a first positioning hole provided on the bottom of the cavity and inserted and matched with the pin in the internal module of the sensor, a second positioning hole inserted and matched with the bus bar in the internal module of the sensor, and a third positioning hole inserted and matched with the positioning post on the mold base in the internal module of the sensor; or the first positioning structure includes a thimble provided on the upper mold and a positioning protrusion provided on the bottom of the cavity. Among them, when the mold is clamped, the upper and lower ends of the circuit board in the internal module of the sensor are respectively in abutting fit with the thimble and the positioning protrusion.

[0011] In the injection mold for the integrated molding current sensor described above, the second positioning structure is located between the bottom of the cavity and the slider, and the second positioning structure adopts a concave-convex insertion fit. Among them, a positioning convex post inserted and matched with the positioning concave hole on the slider is provided on the bottom of the cavity.

[0012] In the injection mold for the integrated molding current sensor described above, a convex platform is provided on the bottom of the cavity. When the internal module of the sensor is assembled into the cavity, the lower surface of the internal module of the sensor contacts the convex platform.

[0013] In the injection mold for the integrated molding current sensor described above, the third positioning structure is located between the upper mold and the slider, and the third positioning structure adopts a abutting fit between surfaces. Among them, a positioning rod corresponding to the position of the slider is provided on the upper mold, and an elastic member is nested on the positioning rod, and the elastic member is clamped between the upper mold and the positioning rod.

[0014] In the injection mold for the integrated molding current sensor described above, the fourth positioning structure is located between the upper mold and the carrier, and the fourth positioning structure adopts a wedge fit. Among them, a positioning block is provided on the upper mold, and a first inclined surface is provided on the positioning block, and a second inclined surface in contact fit with the first inclined surface is provided on the carrier. When the mold is clamped, the first inclined surface slides on the surface of the second inclined surface, so that the carrier is pressed tightly in the lower mold cavity and does not move horizontally.

[0015] In the injection mold for the integrated molding current sensor described above, two convex blocks are provided in the upper mold cavity, and the two convex blocks are arranged oppositely. Among them, after the integrated encapsulation molding of the sensor, two concave portions can be formed at the corresponding positions of the sensor.

[0016] In the injection mold of the integrated molded current sensor described above, when the mold is closed, the first exhaust channel communicates with the second exhaust channel to form the exhaust channel of the mold. Among them, a first exhaust insert is installed in the first exhaust channel, and a second exhaust insert is installed in the second exhaust channel. When the mold is closed, the first exhaust insert abuts and cooperates with the second exhaust insert, and exhaust is carried out through the gap between the contact surfaces of the first exhaust insert and the second exhaust insert.

[0017] In the injection mold of the integrated molded current sensor described above, at least two branches are provided on the glue inlet channel. One of the branches serves as the channel for the glue to flow into the upper mold cavity and the lower mold cavity, and the remaining branches serve as buffer channels for slowing down the flow rate of the glue.

[0018] The present invention also provides a preparation method for an integrated molded current sensor, using the injection mold of the integrated molded current sensor, including the steps:

[0019] S1: Complete the assembly of the internal modules of the sensor, and place the assembled internal modules of the sensor in a carrier;

[0020] S2: Dry the hot melt adhesive, where the drying temperature is 70 °C and the heating duration is 4 - 8 hrs;

[0021] S3: Melt the hot melt adhesive, where the melting temperature of the hot melt adhesive is 210 - 240 °C;

[0022] S4: Keep the hot melt adhesive in a molten state, where the temperature of the hot melt adhesive is maintained at 210 - 240 °C, and the mold temperature is maintained at 20 - 60 °C;

[0023] S5: Loading of the carrier, closing the mold and completing injection molding and pressure holding. Among them, the carrier is loaded into the mold, and then the mold is closed. At this time, the hot melt adhesive is injected into the mold cavity under a certain pressure. Among them, the injection pressure is 0.5 MPa, and pressure holding is carried out for a preset time, and the pressure holding pressure is 5.5 MPa, and the pressure holding time is 5 s. During the pressure holding period, the hot melt adhesive can quickly fill the entire mold cavity;

[0024] S6: Open the mold and complete the demolding of the product. Among them, after the hot melt adhesive fills the mold cavity, it cools and solidifies. Among them, the cooling time is 40 s. After 40 s, the mold is opened, and the injection-molded sensor together with the carrier is removed from the mold, and then the injection-molded sensor is removed from the carrier;

[0025] S7: Baking and annealing, where the injection-molded sensor is baked and annealed in a temperature environment of 55 - 65 °C;

[0026] S8: Laser marking and complete the packaging of the product.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) The first positioning structure, the second positioning structure, the third positioning structure and the fourth positioning structure are provided because during the integrated molding stage of the sensor, the colloid flowing in from the glue inlet channel has a certain impact on the internal module of the sensor placed in the cavity. The existence of the above positioning structures can prevent the internal module of the sensor from moving during the encapsulation process, thus ensuring the encapsulation effect of the internal module of the sensor, and further improving the accuracy and insulation performance of the sensor during subsequent use.

[0029] (2) There is no direct connection structure between the carrier for integrated molding of the sensor and the lower template. The carrier is "locked" in the lower mold cavity in the mold closing state through the third positioning structure and the fourth positioning structure. Therefore, by replacing the carrier, the integrated molding and encapsulation of different types of sensors can be realized, thereby expanding the versatility of the injection mold and achieving multiple uses with one mold.

[0030] (3) By providing a boss on the bottom of the cavity, the colloid injected from the glue inlet channel cannot fill this part, so that a concave surface is formed on the sensor after encapsulation molding corresponding to the boss. The existence of this concave surface can reduce the contact area when the encapsulated sensor is connected to other structures, thereby reducing the flatness requirement of the installation surface of the sensor, fully ensuring that the sensor can be installed horizontally, and reducing the risk of uneven stress on the sensor caused by uneven installation during sensor use.

[0031] (4) By providing an elastic member, the error caused by mold assembly can be compensated, ensuring that the positioning rod can always be in abutting cooperation with the slider after the mold is closed, thereby improving the reliability of the integrated encapsulation molding of the sensor, and further ensuring the accuracy of the sensor during subsequent use.

[0032] (5) By providing a convex block in the upper mold cavity, the colloid injected from the glue inlet channel cannot fill this part, so that a concave part is formed on the sensor after encapsulation molding corresponding to the convex block. Through the setting of the concave part, the thickness of the hot melt adhesive on the outer side of the entire internal module of the sensor is made uniform, and further reduces the stress caused by encapsulation, thereby improving the accuracy of sensor use.

[0033] (6) Through the cooperation between the first exhaust insert and the second exhaust insert, it is used for exhaust during injection molding of the mold, reducing risks such as injection molding air entrapment and incomplete injection molding filling.

[0034] (7) When the colloid flows in from the glue inlet channel, it has a certain impact force. The internal module of the sensor placed in the cavity is positioned through multiple positioning structures. By setting a buffer channel, the flow rate of the colloid flowing into the upper mold cavity and the lower mold cavity can be further reduced, thereby further reducing the impact of the colloid on the internal module of the sensor and reducing the influence of the injection pressure on the performance of the sensor, and then improving the accuracy of the sensor during use after encapsulation and molding. Description of the Drawings

[0035] Figure 1 is a schematic structural diagram of an injection mold for an integrated molded current sensor of the present invention.

[0036] Figure 2 is Figure 1 a schematic structural diagram of the shown injection mold after removing the upper mold assembly.

[0037] Figure 3 is a schematic structural diagram of a carrier in a preferred embodiment of the present invention.

[0038] Figure 4 is Figure 3 a schematic partial structural diagram of the shown carrier.

[0039] Figure 5 is a schematic structural diagram of a slider in a preferred embodiment of the present invention.

[0040] Figure 6 is a schematic structural diagram of an upper mold assembly in a preferred embodiment of the present invention.

[0041] Figure 7 is Figure 6 an enlarged view of part A in

[0042] Figure 8 is Figure 6 a schematic structural diagram of the shown upper mold assembly from another perspective.

[0043] Figure 9 is Figure 8 a cross-sectional view taken along A-A of the shown

[0044] Figure 10 is Figure 8 a cross-sectional view taken along B-B of the shown

[0045] Figure 11 is a schematic structural diagram of an upper template in a preferred embodiment of the present invention.

[0046] Figure 12 is Figure 11 an enlarged view of part B in

[0047] Figure 13 is a schematic structural diagram of the internal module of the sensor after encapsulation in a preferred embodiment of the present invention.

[0048] Figure 14 This is a schematic structural diagram of the internal modules of a sensor in a preferred embodiment of the present invention.

[0049] In the figure, 100 is the upper die assembly; 110 is the upper die holder; 120 is the upper template; 121 is the upper die cavity; 122 is the first exhaust channel; 123 is the bump; 130 is the positioning rod; 140 is the elastic member; 150 is the positioning block; 151 is the first inclined surface; 160 is the first exhaust insert; 170 is the ejector pin; 200 is the lower die assembly; 210 is the lower die holder; 220 is the lower template; 221 is the lower die cavity; 222 is the glue inlet channel; 223 is the buffer channel; 300 is the carrier; 310 is the cavity; 311 is the first positioning hole; 312 is the second positioning hole; 313 is the positioning boss; 314 is the boss; 315 is the positioning protrusion; 320 is the slider; 321 is the positioning concave hole; 330 is the second exhaust channel; 340 is the second inclined surface; 350 is the second exhaust insert; 400 is the internal module of the sensor; 410 is the pin; 420 is the busbar; 430 is the positioning post; 440 is the concave surface; 450 is the recess. Detailed implementation manners

[0050] The following are specific embodiments of the present invention and, in conjunction with the accompanying drawings, the technical solutions of the present invention will be further described, but the present invention is not limited to these embodiments.

[0051] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0052] Embodiment 1

[0053] As Figures 1 to 14 shown, an injection mold for an integrated molded current sensor provided by the present invention includes:

[0054] The upper die assembly 100 includes an upper die holder 110, an upper template 120 connected to the upper die holder 110 through fasteners, and an upper die cavity 121 provided on the upper template 120, and a first exhaust channel 122 communicating with the upper die cavity 121;

[0055] The lower die assembly 200 includes a lower die holder 210, a lower template 220 connected to the lower die holder 210 through fasteners, and a lower die cavity 221 provided on the lower template 220, and a glue inlet channel 222 communicating with the upper die cavity 121 and the lower die cavity 221;

[0056] A vehicle 300 is internally provided with a cavity 310 for placing a sensor internal module 400, and sliders 320 for clamping the sensor internal module 400 placed in the cavity 310 are arranged on both sides of the cavity 310, and a second exhaust passage 330 communicated with the cavity 310. Among them, a first positioning structure for limiting the horizontal movement of the sensor internal module 400 in the cavity 310 and a second positioning structure for limiting the horizontal movement of the slider 320 are arranged on the vehicle 300;

[0057] Among them, when the upper template 120 and the lower template 220 are clamped, the degree of freedom of the slider 320 and the vehicle 300 moving in a direction perpendicular to the demolding direction of the vehicle 300 is limited by a third positioning structure on the upper template 120, and the degree of freedom of the vehicle 300 moving in its demolding direction during the integrated molding stage of the sensor is limited by a fourth positioning structure on the upper template 120.

[0058] It is worth mentioning that through the first positioning structure and the second positioning structure, the relative position in the horizontal direction between the sensor internal module 400 placed in the cavity 310 and the sliders 320 on both sides is fixed. Through the third positioning structure, not only the degree of freedom of the slider 320 moving in a direction perpendicular to the demolding direction of the vehicle 300 is limited, but also the degree of freedom of the vehicle 300 itself moving in a direction perpendicular to the demolding direction is limited. Through the fourth positioning structure, the degree of freedom of the vehicle 300 moving in its demolding direction during the integrated molding stage of the sensor is limited.

[0059] In this embodiment, the reason for setting the first positioning structure, the second positioning structure, the third positioning structure, and the fourth positioning structure is that during the integrated molding stage of the sensor, the colloid flowing in from the glue inlet passage 222 has a certain impact on the sensor internal module 400 placed in the cavity 310, and the existence of the above positioning structures can prevent the sensor internal module 400 from moving during the encapsulation process, thereby ensuring the encapsulation effect of the sensor internal module 400, and further improving the accuracy and insulation performance of the subsequent use of the sensor.

[0060] In addition, the colloid entering from the glue inlet passage 222 is a hot melt adhesive, which is an injection-molded dimer acid type polyamide hot melt resin with a low modulus (50 - 200 MPa) and a low thermal expansion coefficient (200 - 300 ppmk). This hot melt resin has good cold flexural properties and high elongation, and shows good weather resistance under harsh temperature shock conditions.

[0061] Moreover, in this embodiment, there is no direct fixed connection structure between the vehicle 300 formed integrally with the sensor and the lower template 220. The vehicle 300 is "locked" in the lower die cavity 221 in the mold closing state through the third positioning structure and the fourth positioning structure. Therefore, by replacing the vehicle 300, the integrated molding and encapsulation of different types of sensors can be realized, thereby expanding the versatility of the injection mold and achieving multiple uses with one mold.

[0062] Preferably, the first positioning structure is located between the bottom of the cavity 310 and the internal module 400 of the sensor, and the first positioning structure adopts a concave-convex plug-in fit. Among them, on the bottom of the cavity 310, there are a first positioning hole 311 for plugging and matching with the pin 410 in the internal module 400 of the sensor, a second positioning hole 312 for plugging and matching with the bus bar 420 in the internal module 400 of the sensor, and one or more of the third positioning holes for plugging and matching with the positioning posts 430 on the mold base in the internal module 400 of the sensor.

[0063] Preferably, the second positioning structure is located between the bottom of the cavity 310 and the slider 320, and the second positioning structure adopts a concave-convex plug-in fit. Among them, on the bottom of the cavity 310, there is a positioning convex post 313 for plugging and matching with the positioning concave hole 321 on the slider 320.

[0064] It is worth mentioning that the positions of the positioning convex post 313 and the positioning concave hole 321 can be interchangeably set, that is, a positioning convex post 313 is provided on the slider 320, and a positioning concave hole 321 is provided on the bottom of the cavity 310.

[0065] In addition, the material of the slider 320 is generally a metal material. Therefore, the material of the positioning convex post 313 can be selected as a magnetic material. In this way, when the slider 320 is connected to the vehicle 300, not only can the freedom degree of the slider 320 in the horizontal direction in the cavity 310 be limited through the plug-in fit between the positioning convex post 313 and the positioning concave hole 321, but also the freedom degree of the slider 320 in the vertical direction in the cavity 310 can be limited to a certain extent through the magnetic attraction fit between the positioning convex post 313 and the slider 320. The magnetic attraction fit is used to facilitate the removal of the slider 320 from the vehicle 300 after the integrated encapsulation and molding of the sensor, and further facilitate the removal of the sensor from the cavity 310.

[0066] Further preferably, a convex platform 314 is provided on the bottom of the cavity 310. When the internal module 400 of the sensor is assembled into the cavity 310, the lower surface of the internal module 400 of the sensor contacts the convex platform 314.

[0067] In this embodiment, by providing a boss 314 on the bottom of the cavity 310, the colloid injected from the glue inlet channel 222 cannot fill this part, so that a concave surface 440 is formed at the part of the encapsulated and molded sensor corresponding to the boss 314. The existence of this concave surface 440 can reduce the contact area when the encapsulated sensor is connected to other structures, thereby reducing the flatness requirement of the sensor mounting surface, fully ensuring that the sensor can be installed horizontally, and reducing the risk of uneven force on the sensor caused by uneven installation during the use of the sensor.

[0068] Preferably, the third positioning structure is located between the upper template 120 and the slider 320, and this third positioning structure adopts a abutting fit between surfaces. Among them, a positioning rod 130 corresponding to the position of the slider 320 is provided on the upper template 120, and an elastic member 140 is nested on the positioning rod 130, and this elastic member 140 is clamped between the upper template 120 and the positioning rod 130.

[0069] It is worth mentioning that when the upper template 120 and the lower template 220 are closed, the positioning rod 130 and the slider 320 form an abutting fit, firmly pressing the slider 320 on the bottom of the cavity 310, thereby limiting the freedom degree of the slider 320 and the carrier 300 in the vertical direction. In addition, by providing the elastic member 140, the error caused by the assembly of the mold can be compensated, ensuring that the positioning rod 130 can always be in abutting fit with the slider 320 after the mold is closed, thereby improving the reliability of the integrated encapsulation and molding of the sensor, and further ensuring the accuracy of the sensor during subsequent use.

[0070] Preferably, the fourth positioning structure is located between the upper template 120 and the carrier 300, and this fourth positioning structure adopts a wedge fit. Among them, a positioning block 150 is provided on the upper template 120, and a first inclined surface 151 is provided on the positioning block 150. A second inclined surface 340 in contact fit with the first inclined surface 151 is provided on the carrier 300. When the mold is closed, the first inclined surface 151 slides on the surface of the second inclined surface 340, so that the carrier 300 is pressed tightly in the lower mold cavity 221 without horizontal movement.

[0071] Further preferably, two convex blocks 123 are provided in the upper mold cavity 121, and the two convex blocks 123 are arranged oppositely. Among them, when the integrated encapsulation and molding of the sensor is completed, two recesses 450 can be formed at the corresponding positions of the sensor.

[0072] It is worth mentioning that by providing a bump 123 in the upper mold cavity 121, the colloid injected from the glue injection channel 222 cannot fill this part, so that a recess 450 is formed at the part of the encapsulated and molded sensor corresponding to the bump 123. Through the provision of the recess 450, the thickness of the hot melt adhesive outside the entire internal module 400 of the sensor is made uniform, thereby further reducing the stress caused by encapsulation, so as to improve the accuracy of the sensor in use.

[0073] Preferably, when the mold is closed, the first exhaust channel 122 communicates with the second exhaust channel 330 to form the exhaust channel of the mold. Among them, a first exhaust insert 160 is embedded in the first exhaust channel 122, and a second exhaust insert 350 is embedded in the second exhaust channel 330. When the mold is closed, the first exhaust insert 160 abuts and cooperates with the second exhaust insert 350, and exhaust is carried out through the gap between the contact surfaces of the first exhaust insert 160 and the second exhaust insert 350.

[0074] It is worth mentioning that through the cooperation between the first exhaust insert 160 and the second exhaust insert 350, it is used for exhaust during injection molding of the mold, reducing risks such as air entrapment during injection molding and incomplete injection filling.

[0075] Preferably, at least two branches are provided on the glue injection channel 222. One branch is used as the channel for the colloid to flow to the upper mold cavity 121 and the lower mold cavity 221, and the remaining branches are used as buffer channels 223 for slowing down the flow rate of the colloid.

[0076] In this embodiment, when the colloid flows in from the glue injection channel 222, it has a certain impact force. The internal module 400 of the sensor placed in the cavity 310 is positioned through a plurality of positioning structures. By providing the buffer channel 223, the flow rate of the colloid flowing into the upper mold cavity 121 and the lower mold cavity 221 can be further reduced, thereby further reducing the impact of the colloid on the internal module 400 of the sensor and reducing the influence of the injection pressure on the performance of the sensor, so as to improve the accuracy of the sensor during use after encapsulation and molding.

[0077] The present invention also provides a preparation method for an integrally molded current sensor, including the steps:

[0078] S1: Assemble the internal module 400 of the sensor, and place the assembled internal module 400 of the sensor into the carrier 300;

[0079] S2: Dry the hot melt adhesive; that is, perform a drying treatment on the hot melt adhesive before injection molding to remove the moisture in the hot melt adhesive. Among them, the drying temperature is 70 °C, and the heating duration is 4 - 8 hrs;

[0080] S3: Melt the hot melt adhesive; that is, add the dried hot melt adhesive to an injection molding machine for melting treatment. Here, the melting temperature of the hot melt adhesive is 210 - 240°C;

[0081] S4: Insulate the hot melt adhesive in a molten state. Here, the temperature of the hot melt adhesive is maintained at 210 - 240°C, and the temperature of the mold is maintained at 20 - 60°C;

[0082] S5: Load the carrier 300, close the mold and complete injection molding and pressure holding; that is, load the carrier 300 into the mold, then close the mold. At this time, inject the hot melt adhesive into the mold cavity under a certain pressure. Here, the injection pressure is 0.5 MPa, and it is pressure held for a preset time, and the pressure holding pressure is 5.5 MPa, and the pressure holding time is 5 s. During pressure holding, the hot melt adhesive can quickly fill the entire mold cavity;

[0083] S6: Open the mold and complete product demolding; that is, after the hot melt adhesive fills the mold cavity, it cools and solidifies. Here, the cooling time is 40 s. After 40 s, open the mold, remove the injection-molded sensor together with the carrier 300 from the mold, and then remove the injection-molded sensor from the carrier 300. If the sensor demolding is difficult, an appropriate amount of mold release agent can be sprayed on the surface of the sensor;

[0084] S7: Baking and annealing; that is, the injection-molded sensor is baked and annealed in a temperature environment of 55 - 65°C to release residual stress, thereby further reducing the influence of temperature residual stress on the sensor;

[0085] S8: Laser marking and complete product packaging; that is, the mold has been engraved with the logo and product information of the corresponding company. When laser marking, only the product changes need to be marked, so that the marking time is shortened to 20% of the original, thereby further reducing the processing time and processing cost of the product.

[0086] Embodiment 2

[0087] As Figures 1 to 13 shown, compared with Embodiment 1, the difference in this embodiment is that in this embodiment, the positioning post 430 and the third positioning hole matching the positioning post 430 in Embodiment 1 are cancelled, and the ejector pin 170 provided on the upper template 120 and the positioning protrusion 315 provided on the bottom of the cavity 310 are added. Here, when the mold is closed, the upper and lower ends of the circuit board in the sensor internal module 400 are respectively in abutting fit with the ejector pin 170 and the positioning protrusion 315. It can also achieve reliable positioning of the sensor internal module 400 in the cavity 310.

[0088] It should be noted that in the present invention, descriptions such as "first", "second", "one", etc. are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. Terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0089] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0090] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways to substitute, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An injection mold for an integrally formed current sensor, characterized in that, Comprising: An upper die assembly, including an upper die holder, an upper template connected to the upper die holder by fasteners, with an upper die cavity provided on the upper template, and a first exhaust passage communicating with the upper die cavity; A lower die assembly, including a lower die holder, a lower template connected to the lower die holder by fasteners, with a lower die cavity provided on the lower template, and a glue inlet passage communicating with the upper die cavity and the lower die cavity; A carrier, internally provided with a cavity for placing the internal module of the sensor, and on both sides of the cavity, there are sliders for clamping the internal module of the sensor placed in the cavity, and a second exhaust passage communicating with the cavity. Among them, on the carrier, there is a first positioning structure for limiting the horizontal movement of the internal module of the sensor in the cavity, and a second positioning structure for limiting the horizontal movement of the slider; Among them, when the upper template and the lower template are closed, the degrees of freedom of the slider and the carrier moving perpendicular to the demolding direction of the carrier are limited by the third positioning structure on the upper template, and the degree of freedom of the carrier moving along its demolding direction during the integrated molding stage of the sensor is limited by the fourth positioning structure on the upper template; When the mold is closed, the first exhaust passage is connected to the second exhaust passage to form the exhaust passage of the mold. Among them, a first exhaust insert is embedded in the first exhaust passage, and a second exhaust insert is embedded in the second exhaust passage. When the mold is closed, the first exhaust insert abuts and cooperates with the second exhaust insert, and exhaust is carried out through the gap between the contact surfaces of the first exhaust insert and the second exhaust insert.

2. The injection mold for the integrated molded current sensor according to claim 1, characterized in that, The first positioning structure includes one or more of a first positioning hole provided on the bottom of the cavity for plugging and cooperating with the pins in the internal module of the sensor, a second positioning hole for plugging and cooperating with the bus bar in the internal module of the sensor, and a third positioning hole for plugging and cooperating with the positioning posts on the mold base in the internal module of the sensor; or the first positioning structure includes a ejector pin provided on the upper template and a positioning protrusion provided on the bottom of the cavity. Among them, when the mold is closed, the upper and lower ends of the circuit board in the internal module of the sensor respectively form abutting cooperation with the ejector pin and the positioning protrusion.

3. The injection mold for the integrally formed current sensor according to claim 2, characterized in that, The second positioning structure is located between the bottom of the cavity and the slider, and the second positioning structure adopts a concave-convex plugging and cooperating manner. Among them, a positioning convex post for plugging and cooperating with the positioning concave hole on the slider is provided on the bottom of the cavity.

4. The injection mold for the integrated molded current sensor according to claim 1, characterized in that, A convex platform is provided on the bottom of the cavity. When the internal module of the sensor is assembled into the cavity, the lower surface of the internal module of the sensor contacts the convex platform.

5. The injection mold for the integrated molded current sensor according to claim 3, characterized in that, The third positioning structure is located between the upper template and the slider, and the third positioning structure adopts a abutting cooperation between surfaces. Among them, a positioning rod corresponding to the position of the slider is provided on the upper template, and an elastic member is nested on the positioning rod, and the elastic member is clamped between the upper template and the positioning rod.

6. The injection mold for the integrated molded current sensor according to claim 4, characterized in that, The fourth positioning structure is located between the upper template and the carrier, and the fourth positioning structure adopts a wedge-shaped cooperation. Among them, a positioning block is provided on the upper template, and a first inclined surface is provided on the positioning block. A second inclined surface for contact cooperation with the first inclined surface is provided on the carrier. When the mold is closed, the first inclined surface slides on the surface of the second inclined surface, so that the carrier is pressed tightly in the lower die cavity without horizontal movement.

7. The injection mold for the integrated molded current sensor according to claim 1, characterized in that, There are two convex blocks arranged in the upper mold cavity, and the two convex blocks are arranged opposite to each other. Among them, after the integrated packaging of the sensor is formed, two concave parts can be formed at the corresponding positions of the sensor.

8. The injection mold for the integrated molded current sensor according to claim 1, characterized in that, There are at least two branches on the glue inlet channel. One of the branches is used as the channel for the glue to flow into the upper mold cavity and the lower mold cavity, and the remaining branches are used as buffer channels to slow down the flow rate of the glue.

9. A method for preparing an integrally molded current sensor, using the injection mold of the integrally molded current sensor according to any one of claims 1 to 8, characterized in that, It includes the steps: S1: Assemble the internal modules of the sensor and place the assembled internal modules of the sensor into the carrier. S2: Dry the hot melt adhesive. Among them, the drying temperature is 70°C and the heating duration is 4 - 8 hrs. S3: Melt the hot melt adhesive. Among them, the melting temperature of the hot melt adhesive is 210 - 240°C. S4: Insulate the hot melt adhesive in a molten state. Among them, the temperature of the hot melt adhesive is maintained at 210 - 240°C, and the temperature of the mold is maintained at 20 - 60°C. S5: Loading of the carrier, closing the mold and completing injection molding and pressure holding. Among them, load the carrier into the mold, and then close the mold. At this time, inject the hot melt adhesive into the mold cavity under a certain pressure. Among them, the injection pressure is 0.5 MPa, and hold the pressure for a preset time. And the pressure holding pressure is 5.5 MPa, and the pressure holding time is 5 s. During the pressure holding period, the hot melt adhesive can quickly fill the entire mold cavity. S6: Open the mold and complete the demolding of the product. Among them, after the hot melt adhesive fills the mold cavity, it cools and solidifies. Among them, the cooling time is 40 s. After 40 s, open the mold, remove the injection-molded sensor together with the carrier from the mold, and then remove the injection-molded sensor from the carrier. S7: Bake and anneal. Among them, the injection-molded sensor is baked and annealed in a temperature environment of 55 - 65°C. S8: Laser marking and complete the packaging of the product.

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