Magnet pre-embedded integrated trip arm and injection mold therefor

Abstract

The utility model discloses a magnet pre-embedded integrated tripping arm and injection mold for it, can ensure the accurate positioning of magnet. Injection mold includes: first mold part has first side portion inner insert piece, second mold part has second side portion inner insert piece, first axial inner insert piece and second axial inner insert piece are coaxially arranged with first axial inner insert piece, and first axial inner insert piece and second axial inner insert piece form second cavity for accommodating magnet and shaping magnet support seat with first side portion inner insert piece and second side portion inner insert piece, wherein, one end of first axial inner insert piece forms coaxial positioning structure for engaging with axial end of magnet.

Description

Technical Field

[0001] This disclosure belongs to the field of circuit breaker technology, specifically relating to a magnet-pre-embedded integrated trip arm and an injection mold for the same. Background Technology

[0002] In electrical equipment such as circuit breakers, Hall effect sensors are used to detect current and trigger tripping action. Their performance is highly dependent on the stable magnetic field generated by the magnet mounted on the tripping arm.

[0003] In traditional trip arm structures, the trip arm body is injection molded, with pre-drilled grooves for magnet mounting on its surface. After molding, operators manually apply glue to the magnets, determine the N / S pole orientation based on experience, and press the magnets into the mounting grooves on the trip arm body, then bond them together with glue. Assembly is complete after the glue cures.

[0004] In this traditional assembled trip arm structure, the poor fit between the magnet and the trip arm body leads to an unstable magnetic field distribution, affecting the detection sensitivity and reliability of the Hall sensor. Furthermore, manual installation easily results in reversed N / S poles, causing sensor malfunctions or failures. Over long-term use, adhesive aging and failure can also cause the magnet to loosen or even fall off, further impacting the product's long-term stability and reliability. Moreover, the installation process is complex, labor costs are high, yield is low, and it is difficult to meet the needs of automated mass production.

[0005] Therefore, there is an urgent need for an improved trip arm and an injection mold for it, which can at least partially solve problems such as inaccurate magnet positioning, unreliable installation, easy polarity error, and low efficiency. Utility Model Content

[0006] This disclosure aims to provide a magnet-pre-embedded integrated release arm and an injection mold therefor, which can ensure the accurate positioning of the magnet to improve the sensitivity and reliability of Hall sensor detection.

[0007] To solve the above-mentioned technical problems, according to one aspect of this disclosure, an injection mold for a magnet-pre-embedded integrated release arm is provided. The release arm includes a release arm body and a magnet. The release arm body includes a release arm main rod and a magnet support seat located on one side of the release arm main rod. The magnet is supported on the magnet support seat. The injection mold includes: a first mold portion having a first side insert; a second mold portion arranged opposite to the first mold portion and having a second side insert, wherein the first mold portion and the second mold portion are slidably disposed relative to each other, such that they have a mold-engaged state and a mold-separated state; a first axial insert; and a second axial insert, which is connected to the first... An axial insert is coaxially arranged, wherein, in the mold-fitted state, a first cavity for forming the main rod portion of the trip arm is formed between the first mold portion and the second mold portion, wherein, in the mold-fitted state, the first side insert and the second side insert are combined to form an axial through hole, the first axial insert and the second axial insert are coaxially and spaced apart in the axial through hole, and together with the first side insert and the second side insert, form a second cavity for accommodating the magnet and forming the magnet support seat, the first cavity and the second cavity are connected, wherein one end of the first axial insert forms a coaxial positioning structure for engaging with the axial end of the magnet.

[0008] A second cavity is formed by a sliding mold section and a coaxially arranged axial insert, and the first cavity for forming the main rod of the trip arm is connected to the second cavity for forming the magnet support seat, thus achieving a magnet-pre-embedded integrated trip arm. The coaxial positioning structure contacts the magnet end face, ensuring its axial centering and preventing offset. This enables high-precision passive positioning of the magnet before injection molding, preventing magnet detachment and mold damage, and significantly improving the integral molding accuracy of the magnet and the trip arm body. Furthermore, the magnet-pre-embedded integrated trip arm structure prevents magnet loosening during use. This ensures a stable magnetic field distribution in the trip arm, improves the consistency of the Hall sensor response, and thus enhances the sensitivity and reliability of the Hall sensor detection.

[0009] Furthermore, the axial end of the magnet where only the predetermined magnetic pole is located has a coaxial positioning structure that engages with the coaxial positioning structure of the first axial insert 133.

[0010] By ensuring that only the predetermined magnetic poles of the magnet engage with the mold positioning structure, it is guaranteed that the magnet is inserted in a single orientation, eliminating the risk of reverse installation caused by manual determination of the N / S poles. This prevents tripping failure due to incorrect magnetic pole installation, thus ensuring the safety of electrical equipment.

[0011] Further, the first axial insert includes: a tubular portion; and a pin portion, which is coaxially disposed inside the tubular portion, and its upper end is lower than the upper end of the tubular portion to form an axial positioning groove, the axial positioning groove serving as the coaxial positioning structure of the first axial insert. The magnet includes: a magnet body; and an axial positioning protrusion extending coaxially downward from the magnet body, the axial positioning protrusion serving as the coaxial positioning structure of the magnet, and the outer diameter of the axial positioning protrusion being smaller than the outer diameter of the magnet body.

[0012] The axial positioning groove formed by the pin and the tubular part engages with the axial positioning protrusion of the magnet, ensuring accurate axial positioning of the magnet without rotation. The outer diameter of the protrusion is smaller than that of the body, facilitating full plastic coverage and enhancing the bonding strength.

[0013] Furthermore, at least the portions of the first side insert, the second side insert, the tubular portion of the first axial insert, and the second axial insert surrounding the magnet are made of magnetic shielding material; and the pin portion of the first axial insert is made of ferromagnetic material.

[0014] The embedded structure surrounding the magnet uses magnetic shielding materials such as beryllium copper to eliminate unnecessary magnetic attraction between the magnet and the mold structure, facilitating accurate placement of the magnet within the mold. The pin is made of ferromagnetic material, actively attracting the magnet and reliably holding it in its position.

[0015] Furthermore, the tubular portion includes a tubular portion body and an annular flange formed at the upper end of the tubular portion body. The outer diameter of the annular flange is smaller than the outer diameter of the tubular portion body and the outer diameter of the magnet body of the magnet, and the upper end face of the tubular portion body is spaced apart from the lower end face of the magnet body. The inner surfaces of the first side insert and the second side insert, corresponding to the portions of the second cavity, together form an annular groove extending in the circumferential direction.

[0016] The annular flange maintains a gap between the upper end of the tubular part and the magnet body, forming the bottom wall of the magnet support. The annular groove formed by the side insert guides the plastic to fill the side wall of the support evenly. Thus, the magnet support includes a cylindrical side wall and a bottom wall, thereby enhancing the structural strength of the magnet support and the bonding strength between the magnet support and the magnet.

[0017] Furthermore, both the first mold portion and the second mold portion are slidably disposed. The first mold portion includes a first slider, a first slider insert connected to the first slider on the side facing the second mold portion, and a first side insert. The side of the first slider insert facing the second mold portion is provided with a first groove for installing the first side insert. The second mold portion includes a second slider, a second slider insert connected to the second slider on the side facing the first mold portion, and a second side insert. The side of the second slider insert facing the first mold portion is provided with a second groove for installing the second side insert.

[0018] This dual-mold configuration allows the two side inserts to open and close simultaneously, enabling reliable demolding and high-precision mold closing for complex cavities. The slot design supports quick insert replacement, is compatible with various magnet sizes, improves mold versatility and production line flexibility, reduces mold changeover downtime, and increases production efficiency.

[0019] Furthermore, the injection mold also includes a demolding seat, in which the first axial insert is slidably disposed, and the demolding seat is configured to move upward in the mold separation state to push the ejector arm, which has been injection molded, out of the injection mold.

[0020] The ejector base slides into the axial insert, automatically ejecting the release arm after mold opening for damage-free demolding. This avoids plastic deformation or magnet displacement caused by manual prying, improving yield and consistency, reducing manual intervention, and enhancing overall production efficiency and product quality.

[0021] According to another aspect of this disclosure, a magnet-pre-embedded integrated trip arm is provided, comprising: a trip arm body integrally injection molded, the trip arm body including a trip arm main rod and a magnet support seat located on one side of the trip arm main rod; a magnet supported on the magnet support seat and integrally injection molded together with the magnet support seat, the axial end of the magnet having a coaxial positioning structure for engaging with an injection mold.

[0022] The magnet and the trip arm body are integrated through a single injection molding process, achieving a permanent bond without glue or mechanical fasteners. This eliminates the possibility of the magnet becoming loose within the trip arm body, solving the problem of magnet assembly failure in traditional assembly methods. A positioning structure is provided at the axial end of the magnet to ensure precise positioning and stable magnetic field distribution within the trip arm. This improves the consistency of the Hall sensor response, thereby enhancing the sensitivity and reliability of the Hall sensor, and ultimately improving detection accuracy and the stability of the tripping response.

[0023] Furthermore, the magnet has the coaxial positioning structure at the axial end where only the predetermined magnetic pole is located. The magnet includes: a magnet body; and an axial positioning protrusion extending coaxially downward from the magnet body. The axial positioning protrusion serves as the coaxial positioning structure of the magnet, and the outer diameter of the axial positioning protrusion is smaller than the outer diameter of the magnet body. The magnet support includes a cylindrical sidewall and a bottom wall extending radially inward from the cylindrical sidewall. The bottom wall has a bottom wall hole for the axial positioning protrusion of the magnet to pass through.

[0024] The magnet achieves coaxial positioning with the mold during injection molding through axial positioning protrusions. The cylindrical sidewalls and bottom wall form a closed cavity, which enhances the bonding strength with the magnet. This structure ensures that the center of the magnet coincides with the axis of motion of the trip arm, improves the consistency of the magnetic field direction, and guarantees the accuracy of current detection and the reliability of tripping.

[0025] Furthermore, the outer surface of the magnet body has one or more magnet engagement grooves; one or more engagement protrusions that engage with the magnet engagement grooves are correspondingly formed on the cylindrical sidewall of the magnet support.

[0026] The magnet engagement groove and the support base engagement protrusion form a circumferential mechanical engagement, enhancing the interfacial bonding force between the plastic and the magnet and preventing the magnet from rotating or loosening. This structure, in conjunction with the mold positioning structure, achieves "one-time molding and permanent fixation," significantly improving long-term operational reliability and product lifespan. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this disclosure, illustrate exemplary embodiments of the present disclosure and are used to explain the disclosure, but do not constitute an undue limitation of the disclosure. In the drawings:

[0028] Figure 1 This is a cross-sectional structural schematic diagram of an injection mold for a magnet-pre-embedded integrated release arm according to an embodiment of the present disclosure.

[0029] Figure 2 yes Figure 1 The diagram shows a three-dimensional structure of the injection mold from a first-view perspective.

[0030] Figure 3 yes Figure 1 The diagram shows a three-dimensional exploded structure of the injection mold from a second perspective.

[0031] Figure 4 yes Figure 1 The diagram shown is an exploded view of the injection mold.

[0032] Figure 5 This is a three-dimensional structural schematic diagram of a magnet-pre-embedded integrated release arm according to an embodiment of the present disclosure.

[0033] Figure 6 yes Figure 5 The diagram shows a three-dimensional exploded view of the trip arm from a first-angle perspective.

[0034] Figure 7 yes Figure 5 The diagram shows a three-dimensional exploded view of the trip arm from a second perspective.

[0035] Figure 8 yes Figure 5 The diagram shows the main view of the trip arm.

[0036] Reference numerals: 100, Injection mold; 110, First mold part; 111, First slider; 112, First slider insert; 112a, First groove; 113, First side insert; 120, Second mold part; 121, Second slider; 122, Second slider insert; 122a, Second groove; 123, Second side insert; 131, Demolding seat; 133, First axial insert; 133a, Axial positioning groove; 134, Tubular part; 134a, Tubular part body ; 134b, Annular flange; 135, Pin; 136, Guide rod; 137, Push rod; 143, Second axial insert; 200, Tripping arm; 210, Tripping arm body; 211, Tripping arm main rod; 212, Magnet support; 212a, Cylindrical sidewall; 212b, Bottom wall; 212c, Engaging protrusion; 220, Magnet; 220b, Magnet engagement groove; 221, Magnet body; 222, Axial positioning protrusion; C1, First cavity; C2, Second cavity; G, Annular groove. Detailed Implementation

[0037] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0039] To better disclose the proposed solution, firstly, in conjunction with Figures 5 to 8The structure of the magnet-pre-embedded integrated trip arm according to this disclosure will be described. Figure 5 This is a three-dimensional structural schematic diagram of a magnet-pre-embedded integrated trip arm according to an embodiment of the present disclosure. Figure 6 yes Figure 5 The diagram shown is an exploded three-dimensional view of the trip arm from a first perspective. Figure 7 yes Figure 5 The diagram shown is an exploded three-dimensional view of the trip arm from a second perspective. Figure 8 yes Figure 5 The schematic diagram shown is a front view of the sectional structure of the trip arm. This sectional structure is based on... Figure 6 The longitudinal section containing line AA is obtained.

[0040] See Figures 5 to 8 As can be seen, the trip arm 200 includes a trip arm body 210 integrally injection molded and a magnet 220. The trip arm body 210 includes a trip arm main rod 211 and a magnet support seat 212 located on one side of the trip arm main rod 211. The magnet 220 is supported on the magnet support seat 212 and is integrally injection molded with the magnet support seat 212. The axial end of the magnet 220 has a coaxial positioning structure for engaging with the injection mold (see...). Figure 7 and 8 (This shows the axial positioning protrusion 222).

[0041] The magnet and the trip arm body are integrated through a single injection molding process, achieving a permanent bond without glue or mechanical fasteners. This eliminates the possibility of the magnet becoming loose within the trip arm body, solving the problem of magnet assembly failure in traditional assembly methods. A positioning structure is provided at the axial end of the magnet to ensure precise positioning and stable magnetic field distribution within the trip arm. This improves the consistency of the Hall sensor response, thereby enhancing the sensitivity and reliability of the Hall sensor, and ultimately improving detection accuracy and the stability of the tripping response.

[0042] from Figures 5 to 8 As can be seen in the illustrated embodiment, only the axial end of the magnet 220 where the predetermined magnetic pole is located ( Figures 5 to 8 The lower end of the magnet 220 shown has a coaxial positioning structure (see...). Figure 7 and 8 (This shows the axial positioning protrusion 222).

[0043] In this way, operators can more easily distinguish the north and south poles (N / S poles) of the magnet, and the magnet can only engage with the mold positioning structure with the predetermined magnetic pole end. This ensures that the magnet is inserted in a unique direction, thereby completely eliminating the risk of N / S pole reversal. This can fundamentally prevent tripping function failure caused by incorrect magnetic pole installation and ensure the safety of electrical equipment.

[0044] from Figures 5 to 8 As can also be seen, the magnet 220 includes a magnet body 221 and an axial positioning protrusion 222. The axial positioning protrusion 222 extends downward coaxially from the magnet body 221. The axial positioning protrusion 222 serves as a coaxial positioning structure for the magnet 220, and the outer diameter of the axial positioning protrusion 222 is smaller than the outer diameter of the magnet body 221.

[0045] The magnet body 221 and axial positioning protrusion 222 of the magnet 220 shown in the figure are both cylindrical, but optionally, they can be other shapes. For example, they can all be polygonal cylinders, or the magnet body can also be other elliptical shapes, or even irregular shapes. Since the axial positioning protrusion of the magnet is connected to the injection mold 100 (to be combined later)... Figures 1 to 4 The coaxial positioning structure (e.g., axial positioning groove, which is described in detail later in the section on injection molds) on the first axial insert engages with the injection mold. Accordingly, it can be understood that the coaxial positioning structure on the first axial insert on the injection mold can be of various shapes that match the axial positioning structure of the magnet.

[0046] In this embodiment, the outer diameter of the axial positioning protrusion 222 is smaller than the outer diameter of the magnet body 221. This is a preferred embodiment, which allows the magnet 220 to achieve coaxial positioning by engaging with the axial positioning groove on the injection mold through the axial positioning protrusion 222. Simultaneously, it allows the magnet body 221 of the magnet 220 to be stably supported on the upper end of the tubular portion of the first axial insert of the injection mold, thereby achieving reliable positioning and stable support of the magnet. It should be understood that this is merely a preferred embodiment of the radial dimensions of the axial positioning protrusion 222 and the magnet body 221, and is not limited to their specific shapes.

[0047] The magnet support 212 includes a cylindrical sidewall 212a and a bottom wall 212b extending radially inward from the cylindrical sidewall 212a. The bottom wall 212b has a bottom wall hole for an axially positioned protrusion 222 through which the magnet 220 passes. Figure 7 and 8 (As shown in the image).

[0048] The magnet achieves coaxial positioning with the mold during injection molding through axial positioning protrusions. The cylindrical sidewalls and bottom wall form a closed cavity, which enhances the bonding strength with the magnet. This structure ensures that the center of the magnet coincides with the axis of motion of the trip arm, improves the consistency of the magnetic field direction, and guarantees the accuracy of current detection and the reliability of tripping.

[0049] from Figures 5 to 8As can also be seen, the outer surface of the magnet body 221 has one or more magnet engaging grooves 220b, and the inner surface of the cylindrical sidewall of the magnet support 212 correspondingly forms one or more engaging protrusions 212c that engage with the magnet engaging grooves 220b. In an exemplary implementation of multiple magnet engaging grooves 220b, these engaging grooves are preferably uniformly distributed along the circumferential direction of the magnet body 221, for example, there may be two symmetrically distributed grooves, or three grooves distributed at 120-degree angles, or four grooves distributed at 90-degree angles, etc.; these engaging grooves may also optionally be non-uniformly distributed on the outer surface of the magnet body 221. The number and distribution of engaging grooves can be optimized according to the shape and size of the magnet, the required bonding strength, and the specific requirements of the mold design.

[0050] The magnet engagement groove and the support base engagement protrusion form a circumferential mechanical engagement, enhancing the interfacial bonding force between the plastic and the magnet and preventing the magnet from rotating or loosening. This structure, in conjunction with the mold positioning structure, achieves "one-time molding and permanent fixation," significantly improving long-term operational reliability and product lifespan.

[0051] Below, in conjunction with Figures 1 to 4 The structure of the injection mold for a magnet-pre-embedded integrated release arm according to this disclosure is described. Figure 1 This is a cross-sectional view of an injection mold for a magnet-pre-embedded integrated release arm according to an embodiment of the present disclosure. Figure 2 yes Figure 1 The diagram shown is a three-dimensional structural schematic of the injection mold from a first-view perspective. Figure 3 yes Figure 1 The diagram shown is an exploded three-dimensional structure of the injection mold from a second perspective. Figure 4 yes Figure 1 The diagram shown is an exploded view of the injection mold, with some of its structures shown in sectional view.

[0052] See Figures 1 to 4 As can be seen, the injection mold 100 includes a first mold portion 110 and a second mold portion 120 arranged opposite to each other. The first mold portion 110 has a first side insert 113, and the second mold portion 120 has a second side insert 123. At least one of the first mold portion 110 and the second mold portion 120 is slidably arranged as an integral assembly structure, allowing the two mold portions to slide relative to each other, thus moving closer and further apart, enabling the entire injection mold 100 to form a mold-engaged state and a mold-separated state. In the mold-engaged state, a first cavity C1 for forming the main rod portion 211 of the release arm is formed between the first mold portion 110 and the second mold portion 120 (see...). Figure 2 and Figure 3In the mold-fitted state, the first side insert 113 and the second side insert 123 combine to form an axial through hole (see...). Figure 1 ).

[0053] from Figures 1 to 4 As can also be seen, the injection mold 100 further includes a first axial insert 133 and a second axial insert 143 arranged coaxially with the first axial insert 133. These two axial inserts are coaxially and spaced apart within the axial through-hole, and both can move up and down axially. The first axial insert 133 and the second axial insert 143, together with the first side insert 113 and the second side insert 123, form a second cavity C2 for accommodating the magnet 220 and forming the magnet support 212 (see...). Figure 1 The first cavity C1 and the second cavity C2 are connected to form an integral injection molding cavity so as to integrally injection mold the release arm body 210.

[0054] from Figures 1 to 4 It can also be seen that one end of the first axial insert 133 forms a coaxial positioning structure for engaging with the axial end of the magnet 220 (see [link]). Figure 1 and Figure 4 (The axial positioning groove 133a is shown).

[0055] Two mold sections arranged opposite each other form a first cavity for molding the main rod of the trip arm when the molds are joined. The side inserts of the two mold sections, together with a coaxially arranged axial insert, form a second cavity for molding the magnet support. The first and second cavities are connected, allowing for integral injection molding to obtain a magnet-pre-embedded integrated trip arm. The coaxial positioning structure on the first axial insert contacts the magnet end face, ensuring the magnet is axially centered and without offset. This achieves high-precision passive positioning of the magnet before injection molding, preventing magnet detachment and mold breakage, and significantly improving the integral molding accuracy of the magnet and the trip arm body. Furthermore, the magnet-pre-embedded integrated trip arm structure prevents magnet loosening during use. This ensures a stable magnetic field distribution in the trip arm, improves the consistency of the Hall sensor response, and thus enhances the sensitivity and reliability of the Hall sensor detection.

[0056] from Figure 1 and Figure 4 As can be seen, the axial end of the magnet 220 where only the predetermined magnetic pole is located has a coaxial positioning structure that engages with the coaxial positioning structure of the first axial insert 133 (see [link]). Figure 1 and Figure 4 (This shows the axial positioning protrusion 222 on the magnet 220).

[0057] By ensuring that only the predetermined magnetic poles of the magnet engage with the mold positioning structure, it is guaranteed that the magnet is inserted in a single orientation, eliminating the risk of reverse installation caused by manual determination of the N / S poles. This prevents tripping failure due to incorrect magnetic pole installation, thus ensuring the safety of electrical equipment.

[0058] Still refer to Figure 1 and Figure 4 The first axial insert 133 includes a tubular portion 134 and a pin portion 135. The pin portion 135 is coaxially disposed inside the tubular portion 134, and its upper end is lower than the upper end of the tubular portion 134 to form an axial positioning groove 133a. The axial positioning groove 133a serves as a coaxial positioning structure for the first axial insert 133. Correspondingly, the magnet 220 includes a magnet body 221 and an axial positioning protrusion 222 extending coaxially downward from the magnet body 221. The axial positioning protrusion 222 serves as a coaxial positioning structure for the magnet 220, and its outer diameter is smaller than the outer diameter of the magnet body 221.

[0059] The axial positioning groove formed by the pin 135 and the tubular portion 134 engages with the axial positioning protrusion of the magnet, ensuring accurate axial positioning of the magnet. The outer diameter of the axial positioning protrusion of the magnet is smaller than the outer diameter of the magnet body. In addition to achieving reliable positioning and stable support of the magnet as mentioned above, it also facilitates the full coverage of the magnet by the plastic during injection molding, thereby enhancing the bonding strength.

[0060] At least the portions of the first side insert 113, the second side insert 123, the tubular portion 134 of the first axial insert 133, and the second axial insert 143 surrounding the magnet 220 are made of magnetic shielding material.

[0061] For example, in one embodiment, the tubular portion 134 of the first axial insert 133 is made of a magnetic shielding material, and the pin portion 135 of the first axial insert 133 is made of a ferromagnetic material.

[0062] In another embodiment, for example, the tubular portion 134 of the first side insert 113, the second side insert 123, the first axial insert 133, and the second axial insert 143 are all made of magnetic shielding material, and the pin portion 135 of the first axial insert 133 is made of ferromagnetic material.

[0063] The embedded structure surrounding the magnet uses a magnetic shielding material such as beryllium copper (e.g., material C17200). This material is unresponsive to the magnet's magnetic properties, allowing the magnet to be easily placed into the cavity. This eliminates unnecessary magnetic attraction between the magnet and the mold structure, facilitating accurate placement. The pin is made of a ferromagnetic material (e.g., iron) to actively attract the magnet. Once placed, the magnet is firmly held and reliably maintained in its position. This prevents the magnet from detaching from the mold due to vibration during injection molding, thus avoiding the risk of mold failure.

[0064] See still Figure 1 and Figure 4 In the injection mold 100, the tubular portion 134 of the first axial insert 133 includes a tubular body 134a and an annular flange 134b formed on the upper end of the tubular body 134a. The outer diameter of the annular flange 134b is smaller than the outer diameter of the tubular body 134a and the outer diameter of the magnet body 221 of the magnet 220, and the upper end face of the tubular body 134a is spaced apart from the lower end face of the magnet body 221. Figure 1 It can also be seen that the inner surfaces of the first side insert 113 and the second side insert 123, corresponding to the parts of the second cavity C2, together form an annular groove G extending in the circumferential direction.

[0065] The annular flange maintains a gap between the upper end of the tubular part and the magnet body, forming the bottom wall of the magnet support. The annular groove formed by the side insert guides the plastic to fill the side wall of the support evenly. Thus, the magnet support includes a cylindrical side wall and a bottom wall, thereby enhancing the structural strength of the magnet support and the bonding strength between the magnet support and the magnet.

[0066] See still Figures 1 to 4 The first mold part and the second mold part are both slidably arranged relative to each other. The first mold part is the first mold part 110, and the second mold part is the second mold part 120.

[0067] The first mold portion 110 includes a first slider 111, a first slider insert 112 connected to the side of the first slider 111 facing the second mold portion 120, and a first side insert 113. The side of the first slider insert 112 facing the second mold portion 120 is provided with a first groove 112a for mounting the first side insert 113.

[0068] The second mold portion 120 includes a second slider 121, a second slider insert 122 connected to the side of the second slider 121 facing the first mold portion 110, and a second side insert 123. The side of the second slider insert 122 facing the first mold portion 110 is provided with a second groove 122a for mounting the second side insert 123.

[0069] This dual-mold configuration allows the two side inserts to open and close simultaneously, enabling reliable demolding and high-precision mold closing for complex cavities. The slot design supports quick insert replacement, is compatible with various magnet sizes, improves mold versatility and production line flexibility, reduces mold changeover downtime, and increases production efficiency.

[0070] Although in the illustrated embodiment, both the first groove 112a and the second groove 122a are rectangular cross-section grooves, it is also feasible to replace them with grooves of other cross-sections, as long as they can reliably fix the side inserts.

[0071] See still Figures 1 to 4 The injection mold 100 may also include a demolding seat 131. The first axial insert 133 is slidably disposed in the demolding seat 131. The demolding seat 131 is slidably disposed along the guide rod 136 and is fixedly connected to the upper end of the push rod 137. Therefore, in the mold separation state, the demolding seat 131 can move upward along the guide rod 136 under the action of the push rod 137 to push the injection-molded release arm 200 out of the injection mold 100.

[0072] The ejector base slides into the axial insert, automatically ejecting the release arm after mold opening for damage-free demolding. This avoids plastic deformation or magnet displacement caused by manual prying, improving yield and consistency, reducing manual intervention, and enhancing overall production efficiency and product quality.

[0073] Preferably, the second axial insert 143 can also be configured to be movable along the axial direction, thereby facilitating the placement of the magnet into the mold and the demolding of the workpiece.

[0074] This disclosed magnet-embedded integrated trip arm utilizes an integrated injection molding process to achieve precise positioning and secure integration of the magnet and the trip arm. This results in a more stable and robust magnetic field response when the finished product is used with a Hall sensor, improving the overall performance of the sensing system. By changing the magnet installation method, the N / S inversion of the magnet is completely eliminated, and the loosening or detachment of the magnet due to adhesive curing failure is also eliminated, effectively improving product reliability.

[0075] The injection mold disclosed herein has a magnet pre-embedded part, which enables precise pre-embedding of the magnet during the injection molding stage, and has an integral trip arm molding cavity, which enables the magnet and trip arm to be integrated into the molding process. This injection mold has a compact structure, high assembly efficiency, and adapts to the needs of automated and highly consistent mass production. It can also ensure the stability of the magnetic field of the injection molded trip arm and improve the detection accuracy of the sensor.

[0076] The above are merely preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this disclosure, and these improvements and modifications should also be considered within the scope of protection of this disclosure.

Claims

1. An injection mold for a magnet-pre-embedded integrated trip arm, the trip arm (200) comprising a trip arm body (210) and a magnet (220), the trip arm body (210) comprising a trip arm main rod portion (211) and a magnet support seat (212) located on one side of the trip arm main rod portion (211), the magnet (220) being supported on the magnet support seat (212), characterized in that, The injection mold (100) includes: The first mold portion (110) has a first side insert (113). The second mold part (120) is arranged opposite to the first mold part (110) and has a second side insert (123). The first mold part (110) and the second mold part (120) are slidably arranged relative to each other, so that they have a mold-joined state and a mold-separated state. First axial insert (133); and The second axial insert (143) is arranged coaxially with the first axial insert (133). In the mold engagement state, a first cavity (C1) for forming the main rod portion (211) of the trip arm is formed between the first mold portion (110) and the second mold portion (120). In the mold-fitted state, the first side insert (113) and the second side insert (123) combine to form an axial through hole. The first axial insert (133) and the second axial insert (143) are coaxially and spaced apart in the axial through hole, and together with the first side insert (113) and the second side insert (123), form a second cavity (C2) for accommodating the magnet (220) and forming the magnet support (212). The first cavity (C1) and the second cavity (C2) are connected. One end of the first axial insert (133) forms a coaxial positioning structure for engaging with the axial end of the magnet (220).

2. The injection mold according to claim 1, characterized in that, The axial end of the magnet (220) where only the predetermined magnetic pole is located has a coaxial positioning structure that engages with the coaxial positioning structure of the first axial insert (133).

3. The injection mold according to claim 2, characterized in that, The first axial insert (133) includes: Tubular portion (134); and A pin (135) is coaxially disposed inside the tubular portion (134), and its upper end is lower than the upper end of the tubular portion (134) to form an axial positioning groove (133a), which serves as the coaxial positioning structure of the first axial insert (133). The magnet (220) includes: Magnet body (221); and An axial positioning protrusion (222) extends coaxially downward from the magnet body (221), the axial positioning protrusion (222) serves as the coaxial positioning structure of the magnet (220), and the outer diameter of the axial positioning protrusion (222) is smaller than the outer diameter of the magnet body (221).

4. The injection mold according to claim 3, characterized in that, At least the portions surrounding the magnet (220) of the tubular portion (134) of the first side insert (113), the second side insert (123), the first axial insert (133), and the second axial insert (143) are made of magnetic shielding material; and The pin (135) of the first axial insert (133) is made of ferromagnetic material.

5. The injection mold according to claim 3, characterized in that, The tubular portion (134) includes a tubular portion body (134a) and an annular flange (134b) formed at the upper end of the tubular portion body (134a). The outer diameter of the annular flange (134b) is smaller than the outer diameter of the tubular portion body (134a) and the outer diameter of the magnet body (221) of the magnet (220), and the upper end face of the tubular portion body (134a) is spaced apart from the lower end face of the magnet body (221). The inner surfaces of the first side insert (113) and the second side insert (123) corresponding to the portion of the second cavity (C2) together form an annular groove (G) extending in the circumferential direction.

6. The injection mold according to claim 1, characterized in that, Both the first mold portion (110) and the second mold portion (120) are slidably disposed. The first mold portion (110) includes a first slider (111), a first slider insert (112) connected to the first slider (111) on the side facing the second mold portion (120), and a first side insert (113). The first slider insert (112) has a first groove (112a) for mounting the first side insert (113) on the side facing the second mold portion (120). The second mold portion (120) includes a second slider (121), a second slider insert (122) connected to the second slider (121) on the side facing the first mold portion (110), and a second side insert (123). The second slider insert (122) has a second groove (122a) for mounting the second side insert (123) on the side facing the first mold portion (110).

7. The injection mold according to claim 1, characterized in that, The injection mold (100) further includes a demolding seat (131), in which the first axial insert (133) is slidably disposed. The demolding seat (131) is configured to move upward in the mold separation state to push the ejector arm (200) after injection molding out of the injection mold (100).

8. A magnet-pre-embedded integrated release arm, characterized in that, include: The trip arm body (210) is integrally injection molded. The trip arm body (210) includes a trip arm main rod (211) and a magnet support seat (212) located on one side of the trip arm main rod (211). A magnet (220) is supported on the magnet support base (212) and integrally formed with the magnet support base (212) by injection molding. The axial end of the magnet (220) has a coaxial positioning structure for engaging with the injection mold.

9. The tripping arm according to claim 8, characterized in that, The magnet (220) has the coaxial positioning structure only at the axial end where the predetermined magnetic pole is located. The magnet (220) includes: Magnet body (221); and An axial positioning protrusion (222) extends coaxially downward from the magnet body (221). The axial positioning protrusion (222) serves as the coaxial positioning structure of the magnet (220), and the outer diameter of the axial positioning protrusion (222) is smaller than the outer diameter of the magnet body (221). The magnet support (212) includes a cylindrical sidewall (212a) and a bottom wall (212b) extending radially inward from the cylindrical sidewall (212a), the bottom wall (212b) having a bottom wall hole for the axial positioning protrusion (222) through which the magnet (220) passes.

10. The tripping arm according to claim 9, characterized in that, The outer surface of the magnet body (221) has one or more magnet engagement grooves (220b); One or more engagement protrusions (212c) are formed on the cylindrical sidewall of the magnet support (212) to engage with the magnet engagement groove (220b).

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