Electromagnetic switch cover assembly for starter

Abstract

The invention relates to an electromagnetic switch cover assembly for a starter, and the assembly comprises a switch cover body which is provided with a wiring accommodation groove, and the bottom surface of the interior of the wiring accommodation groove is provided with a bolt hole; the wiring bolt comprises a wiring screw rod part which is in threaded connection with the bolt hole; the wiring screw part is square, an eccentric distance e exists between the axis O1 of the wiring screw part and the axis 02 of the wiring screw part in the radial direction, and the width of the wiring accommodating groove is larger than that of the wiring screw part and smaller than the diagonal length of the wiring screw part; the groove wall of the wiring containing groove comprises a reinforcing area and a containing area, the structural strength of the reinforcing area is higher than that of the containing area, and the reinforcing area is arranged on the rotating track of the wiring nut part. The problem that a weak area is prone to cracking when the head of a wiring bolt abuts against the weak area due to the fact that the weak area exists in a square groove of a switch cover in the prior art can be solved.

Description

Technical Field

[0001] This application relates to the field of automotive starters, and more particularly to an electromagnetic switch cover assembly for a starter motor. Background Technology

[0002] As the core control component of an automotive starter, the electromagnetic switch plays a crucial role in controlling the engagement and disengagement of the starter gears and the switching on and off of the main circuit. Its structural reliability is directly related to the overall performance and service life of the starter.

[0003] Currently, electromagnetic switches typically consist of a plastic switch cover assembly and an electromagnetic component assembly. The top of the switch cover has a square slot for mounting a wiring bolt, and the bottom of the slot has bolt holes. Specifically, the wiring bolt has a square head and is coaxially connected to a wiring screw. The square head of the wiring bolt is accommodated within the square slot inside the switch cover. The width of the square slot is greater than the width of the bolt head in the direction of its direction, but less than the diagonal of the bolt head. When tightening the wiring bolt, the nut rotates the square head of the bolt within the square slot until the corner of the square head abuts against the side wall of the square slot.

[0004] However, during assembly, when tightening the wiring bolt with a nut, the clockwise torque applied by the nut forces the bolt head to rotate slightly counterclockwise within the square groove until its side contacts the groove wall. Since the width of the square groove is slightly larger than the width of the wiring bolt head, the square head of the wiring bolt typically makes non-line contact with the square groove, and the position where the wiring bolt abuts against the side wall of the square groove is random. Simultaneously, the square groove of the electromagnetic switch cover also has a connecting through-hole next to the bolt hole for fixing to the electromagnetic component, resulting in a thinner sidewall near the connecting through-hole within the square groove, creating a weak area.

[0005] When the head of the terminal bolt rotates, if it happens to come into contact with the weak area, the weak area will bear most of the counter-torque that presses against the head of the terminal bolt, causing the weak area to crack easily due to stress concentration. Summary of the Invention

[0006] This application provides an electromagnetic switch cover assembly for a starter motor to solve the problem in related technologies where there are weak areas in the square groove of the switch cover, which can easily cause cracking when the head of the wiring bolt is pressed against the weak area.

[0007] This application provides an electromagnetic switch cover assembly for a starter motor, characterized in that it comprises: The switch cover body has a wiring receiving groove, and the wiring receiving groove has a bolt hole on the bottom surface; And, wiring bolts, which include: The wiring screw part is threadedly connected to the bolt hole; The wiring nut is square, and there is a radial eccentricity e between the axis O1 of the wiring screw and the axis O2 of the wiring nut. The width D of the wiring receiving groove is greater than the width d1 of the wiring nut and less than the diagonal length d2 of the wiring nut. The groove wall of the wiring receiving groove includes a reinforcing region and a receiving region. The structural strength of the reinforcing region is higher than that of the receiving region, and the reinforcing region is located on the rotation trajectory of the wiring nut.

[0008] In one embodiment, the wall thickness of the reinforcing region is greater than the wall thickness of the receiving region.

[0009] In one embodiment, the eccentricity e is set to 0.2 mm to 0.4 mm.

[0010] In one embodiment, a connecting through hole is further provided on the bottom surface of the wiring receiving groove. The connecting through hole and the bolt hole are spaced apart along the length direction of the wiring receiving groove, and the connecting through hole is provided corresponding to the receiving area. The connecting through hole is used for electromagnetic components to pass through.

[0011] In one embodiment, the switch cover body is made of engineering plastic.

[0012] In one embodiment, the wiring bolt is made of a conductive metal material.

[0013] In one embodiment, an electromagnetic switch cover assembly for a starter motor further includes: A locking nut is connected to the wiring nut and can drive the wiring nut to rotate within the wiring receiving groove.

[0014] In one embodiment, an electromagnetic switch cover assembly for a starter motor further includes: A reinforcing member is disposed on the reinforced area.

[0015] In one embodiment, the reinforcing member includes: A reinforcing patch is disposed on the sidewall of the wiring receiving slot in the reinforced area.

[0016] In one embodiment, the reinforcing member includes: A reinforcing member is disposed within the reinforced area.

[0017] The beneficial effects of the technical solution provided in this application include: by setting a reinforcing area and a receiving area on the side wall of the wiring receiving groove of the switch cover body, and then setting the reinforcing area on the rotation trajectory of the wiring nut, the wiring nut can be pressed against the reinforcing area when the operator tightens the wiring bolt, and the reinforcing area bears the counter-torque of the wiring nut. Since the structural strength of the reinforcing area is greater than that of the receiving area, the possibility of cracking of the reinforcing area can be effectively reduced. In addition, since there is an eccentricity e in the radial direction between the axis O1 of the wiring screw and the axis O2 of the wiring nut, the wiring nut moves in an elliptical trajectory in the wiring receiving groove when it rotates with the wiring screw. The existence of the eccentricity e allows the wiring nut to contact the groove wall earlier, that is, the rotation angle of the wiring screw is smaller, and the rotation trajectory of the corner of the square wiring nut is shorter. This makes the proportion of the reinforcing area in the wiring receiving groove smaller, making it easier for the wiring nut to abut against the reinforcing area while saving the initial manufacturing cost.

[0018] This application provides an electromagnetic switch cover assembly for a starter motor. Because the wiring nut and the wiring screw have a radial eccentricity e to shorten the rotational stroke of the wiring nut against the side wall, and a reinforcing area is provided on the movement trajectory of the wiring nut, the reinforcing area bears the counter-torque of the wiring nut. Therefore, it solves the problem in the related art that there is a weak area in the square groove of the switch cover, which causes the weak area to crack easily when the wiring bolt head is pressed against the weak area. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Fig. 1 A side view of an electromagnetic switch cover assembly for a starter provided in an embodiment of this application; Fig. 2 This is a schematic diagram of the structure of the wiring bolt provided in the embodiments of this application; Fig. 3 A top view of an electromagnetic switch cover assembly for a starter provided in an embodiment of this application; In the diagram: 1. Switch cover body; 11. Wiring receiving groove; 12. Reinforced area; 13. Receiving area; 14. Connecting through hole; 2. Wiring bolt; 21. Wiring screw part; 22. Wiring nut part. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] This application provides an electromagnetic switch cover assembly for a starter motor, which solves the problem in related technologies where there are weak areas in the square groove of the switch cover, causing the weak areas to crack easily when the head of the wiring bolt 2 is pressed against the weak area.

[0023] Reference Figs. 1 to 3 This application discloses an electromagnetic switch cover assembly for a starter motor, which includes a switch cover body 1 and a wiring bolt 2. The switch cover has a wiring receiving groove 11, and a bolt hole is formed in the bottom surface of the wiring receiving groove 11. The wiring bolt 2 includes a wiring screw part 21 and a wiring nut part 22. The wiring screw part 21 is threadedly engaged with the bolt hole. The wiring nut part 22 is square. The width D of the wiring receiving groove 11 is greater than the width d1 of the wiring nut part 22, so that the wiring nut part 22 can be located in the wiring receiving groove 11. The width D of the wiring receiving groove 11 is less than the diagonal length d2 of the wiring nut part 22, so that when the wiring nut part 22 rotates with the wiring screw part 21, the corner of the wiring nut part 22 can abut against the side wall of the wiring receiving groove 11.

[0024] To allow operators to achieve contact between the wiring nut 22 and the side wall of the wiring receiving groove 11 with a small deflection angle, an eccentricity e exists radially between the axis O1 of the wiring screw 21 and the axis O2 of the wiring nut 22. This causes the wiring nut 22 to make an elliptical circular motion within the wiring receiving groove 11 as it rotates with the wiring screw 21, thereby shortening the travel distance between the wiring nut 22 and the side wall of the wiring receiving groove 11. The groove wall of the switch cover body 1 at the wiring receiving groove 11 includes a reinforcing region 12 and a receiving region 13. The reinforcing region 12 has a higher structural strength than the receiving region 13, and the reinforcing region 12 is located on the rotation trajectory of the wiring nut 22, so that the wiring nut 22 can be tightly abutted against the reinforcing region 12 with higher structural strength. Because the reinforcing region 12 has higher structural strength, it can more stably withstand the counter-torque of the wiring nut 22, reducing the possibility of cracking. Furthermore, due to the eccentricity e between the axis of the wiring nut 22 and the axis of the wiring screw 21, the proportion of the reinforced area 12 can be reduced, thereby reducing the initial manufacturing cost. This solves the problem in related technologies where there is a weak area in the square groove of the switch cover, which causes the weak area to crack easily when the head of the wiring bolt 2 is pressed against the weak area.

[0025] In the structural design of the electromagnetic switch cover, the dimensional matching between the wiring receiving groove and the wiring nut directly affects the reliability of the assembly process and the structural durability. Since the width D of the wiring receiving groove 11 is typically set to 16mm, and the width d1 of the wiring nut 22 is 15mm, the width D of the wiring receiving groove 11 is only slightly larger than the width d1 of the wiring nut 22 by 1mm. If the eccentricity e is not properly set, the wiring nut 22 is prone to jamming due to premature contact with the groove wall under tightening torque, leading to obstructed rotation or even a sudden increase in local stress. Therefore, to prevent the wiring nut 22 from being unable to rotate within the wiring receiving groove 11, the eccentricity e should be selected based on the actual operating conditions. While shortening the rotation stroke of the wiring nut 22, the normal rotation of the wiring nut 22 and the threaded connection of the wiring screw 21 should not be affected. For reference, the eccentricity e can be specifically set to 0.2mm to 0.4mm, with 0.3mm being the best. This ensures that while shortening the rotation stroke, the accuracy and reliability of the threaded connection are not affected, avoiding the risk of screw meshing interference or assembly loosening caused by excessive eccentricity.

[0026] In one embodiment of this application, optimizing the wall thickness of the reinforcing region 12 is a key step in improving its structural performance. The wall thickness of the reinforcing region 12 is greater than that of the accommodating region 13, resulting in a higher structural density and thus higher structural strength. Furthermore, this structural design not only significantly improves the material density of the reinforcing region 12 but also fundamentally improves its mechanical response characteristics. The thickened wall structure enhances the moment of inertia of the cross-section, enabling the reinforcing region 12 to more efficiently disperse stress when subjected to the tightening torque of the wiring nut portion 22, avoiding the generation of local stress concentration peaks.

[0027] Furthermore, in one embodiment of this application, the switch cover body 1 is made of engineering plastic, and the receiving area 13 is also made of engineering plastic, such as polyamide 6 (PA6) or polyamide 66 (PA66). These materials, due to their excellent processing performance, good chemical resistance, and low cost advantages, have become a common choice in automotive parts manufacturing and are suitable for mass production of the switch cover body 1 and the receiving area 13. To further enhance the structural strength of the reinforcing area 12, the reinforcing area 12 is made of high-performance engineering plastic with a structural strength greater than that of the receiving area 13, such as glass fiber reinforced polyamide 6 (GF-PA6) or polyether ether ketone (PEEK). Among them, GF-PA6 significantly improves the tensile strength, stiffness, and fatigue resistance of the material through the composite reinforcement of glass fiber. Its molecular chain structure can more effectively disperse stress when under stress, avoiding local stress concentration. PEEK, with its high crystallinity, excellent heat resistance, and mechanical stability, can still maintain structural integrity under extreme working conditions, making the structural strength of the reinforcing area 12 higher than that of the receiving area 13 and other parts of the switch cover body 1, thereby providing stable support for the wiring nut portion 22. This differentiated material configuration strategy ensures that the structural strength of the reinforced area 12 is not only higher than that of the accommodating area 13 and other parts of the switch cover body 1, but also optimizes the stress transmission path so that the wiring nut part 22 can obtain more uniform and reliable support during the assembly and tightening process. At the same time, it achieves a comprehensive improvement in the structural performance of the switch cover body 1 under the premise of controllable cost, and provides a practical solution for cost reduction and efficiency improvement of the switch cover body 1.

[0028] Furthermore, a connecting through hole 14 is also provided on the bottom surface of the wiring receiving groove 11. The connecting through hole 14 and the bolt hole are spaced apart along the length of the wiring receiving groove 11, and the connecting through hole 14 is set corresponding to the receiving area 13 to allow the electromagnetic component to pass through. In one embodiment of this application, the wiring receiving groove 11 is also set as square, and two threaded holes are spaced apart along the length of the wiring receiving groove 11. The connecting through hole 14 is specifically set between the two threaded holes to facilitate the passage of the electromagnetic component and to facilitate the stable connection of the wiring bolt 2. Since the connecting through hole 14 only serves as a channel for connecting the electromagnetic component and does not need to provide additional support force, the connecting through hole 14 is set corresponding to the receiving area 13, and the required support strength is lower than the counter-torque load that the reinforced area 12 needs to bear.

[0029] Furthermore, to further extend the service life of the terminal bolt 2, it is made of a conductive metal material. This ensures that the terminal bolt 2 possesses both high structural strength and stability while providing a stable connection, making it more convenient to use. In the initial material selection, the terminal bolt 2 is preferably made of a highly conductive metal material, such as phosphor bronze or brass. Phosphor bronze, as a copper-tin-phosphorus ternary alloy, effectively reduces contact resistance due to its excellent conductivity, preventing electrical failure caused by localized overheating during current flow. It also possesses high tensile strength and excellent wear resistance, significantly enhancing the structural stability of the terminal bolt 2 during tightening and assembly, reducing micro-deformation or wear caused by repeated torque. The addition of tin further improves the hardness and fatigue resistance of the terminal bolt 2, enabling it to maintain a stable electrical connection even under automotive vibrations and complex operating conditions, thereby extending its service life. Brass, a copper-zinc alloy, is another preferred choice due to its good conductivity, moderate mechanical strength, and excellent corrosion resistance. Its appropriate zinc content ensures the long-term stability of the terminal bolt 2 in humid and oily environments, avoiding the effects of oxidation and corrosion. Simultaneously, its excellent ductility facilitates precision machining, allowing the terminal bolt 2 to form a tight fit with the terminal nut 22 during assembly, reducing the risk of loosening. The selection of these materials not only meets the high-strength structural support requirements of the terminal bolt 2 but also fundamentally solves the problems of poor contact, arcing, or premature failure caused by insufficient conductivity or strength in traditional terminal bolts through the synergistic effect of optimized conductive paths and mechanical properties. This achieves a dual improvement in the stability of the wiring function and ease of operation, providing a crucial guarantee for the overall reliability of the electromagnetic switch.

[0030] To facilitate the rotation of the wiring nut 22, a locking nut is added to assist in its rotation, allowing the operator to rotate the wiring nut 22 by tightening the locking nut. In one embodiment of this application, since the wiring nut 22 is located inside the wiring receiving groove 11, and the width of the wiring receiving groove 11 is relatively narrow, a threaded hole can be provided at the end of the wiring nut 22 away from the wiring screw 21 for the locking nut to connect. The operator can then thread the locking nut onto the wiring nut 22, thereby driving the wiring nut 22 to rotate. In another embodiment of this application, a hexagonal limiting hole can also be provided at the end of the wiring nut 22 away from the wiring screw 21. The locking nut is configured with an end face structure that mates with the hexagonal limiting hole, allowing the locking nut to be inserted into the hexagonal limiting hole, thereby driving the wiring nut 22 to rotate.

[0031] Furthermore, in other embodiments of this application, in order to further increase the structural strength of the reinforced region 12 and provide more stable anti-torque support for the wiring nut portion 22, a reinforcing member is also added to the side wall of the wiring receiving groove 11 located in the reinforced region 12.

[0032] More specifically, in one embodiment of this application, the reinforcing member includes a reinforcing patch, which is specifically made of a high-strength metal patch and fixed to the groove wall located in the reinforcing region 12, thereby abutting against the corner of the wiring nut 22 to provide stable support for the corner of the wiring nut 22. Specifically, the reinforcing patch preferably uses 304 stainless steel or phosphor bronze as the base material. 304 stainless steel, with its extremely high tensile strength and excellent corrosion resistance, can maintain structural stability for a long time under complex working conditions such as high temperature, high humidity and oil contamination. Its austenitic crystal structure gives the material excellent toughness and fatigue resistance, effectively resisting the fretting wear caused by the tightening torque repeatedly applied during assembly, and avoiding the failure of the support point of the reinforcing region 12 caused by the deformation of the metal surface. Phosphor bronze, through the special molecular arrangement of the copper-tin-phosphorus ternary alloy, exhibits ultra-high hardness and wear resistance. It forms a dense protective layer in the reinforcing region 12, ensuring that it can maintain accurate geometric support precision even in multiple tightening operations. The common advantage of these two materials lies in the compatibility of their coefficients of thermal expansion with those of the engineering plastic matrix, which can effectively reduce interfacial stress caused by temperature changes and avoid the risk of delamination between the metal patch and the plastic tank wall.

[0033] During the manufacturing process, the reinforcing patch can be fixed to the inner side of the groove wall of the reinforcing region 12 by laser welding or mechanical locking. Its high rigidity characteristics evenly distribute the counter-torque of the wiring nut 22 to a larger bearing area of ​​the reinforcing region 12, fundamentally suppressing the stress concentration peak of the reinforcing region 12 and significantly improving the structural strength. However, it should be noted that although the introduction of the reinforcing patch will slightly increase the initial manufacturing cost, its significant suppression of cracking risk under extreme conditions, such as high vibration and high load assembly environments, provides operators with a clear decision-making basis. It is preferred in high-end vehicle applications with stringent reliability requirements, while a simplified solution can be selected under standard conditions, thereby achieving an optimal balance between structural performance and cost control, and ensuring the reliability of the switch cover body 1.

[0034] In addition, reinforcing members can be added to the groove wall of reinforced area 12, which can also improve the structural strength of the groove wall at reinforced area 12. However, whether by adding reinforcing patches or reinforcing members, the initial manufacturing cost of the switch cover body 1 will increase. However, the design of reinforcing members can significantly improve its structural strength. Operators can consider whether to add reinforcing members according to the actual working conditions and from the perspective of manufacturing costs, so as to flexibly adapt to different working conditions.

[0035] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0036] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0037] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An electromagnetic switch cover assembly for a starter motor, characterized in that, It includes: The switch cover body (1) has a wiring receiving groove (11) on it, and the wiring receiving groove (11) has a bolt hole on the bottom surface; And, wiring bolt (2), which includes: The wiring screw part (21) is threadedly connected to the bolt hole; The wiring nut (22) is square, and there is an eccentricity e in the radial direction between the axis O1 of the wiring screw (21) and the axis O2 of the wiring nut (22). The width D of the wiring receiving groove (11) is greater than the width d1 of the wiring nut (22) and less than the diagonal length d2 of the wiring nut (22). The groove wall of the wiring receiving groove (11) includes a reinforcing region (12) and a receiving region (13). The structural strength of the reinforcing region (12) is higher than that of the receiving region (13), and the reinforcing region (12) is located on the rotation trajectory of the wiring nut (22).

2. The electromagnetic switch cover assembly for a starter motor as described in claim 1, characterized in that: The wall thickness of the reinforced region (12) is greater than the wall thickness of the accommodating region (13).

3. The electromagnetic switch cover assembly for a starter motor as described in claim 1, characterized in that: The eccentricity e is set to 0.2 mm to 0.4 mm.

4. The electromagnetic switch cover assembly for a starter motor as described in claim 1, characterized in that: The wiring receiving groove (11) is provided with a connecting through hole (14) on the bottom surface. The connecting through hole (14) and the bolt hole are spaced apart along the length direction of the wiring receiving groove (11), and the connecting through hole (14) is provided corresponding to the receiving area (13). The connecting through hole (14) is used for electromagnetic components to pass through.

5. The electromagnetic switch cover assembly for a starter motor as described in claim 1, characterized in that: The switch cover body (1) is made of engineering plastic.

6. The electromagnetic switch cover assembly for a starter motor as described in claim 1, characterized in that: The wiring bolt (2) is made of conductive metal material.

7. The electromagnetic switch cover assembly for a starter motor as described in claim 1, characterized in that, Also includes: The locking nut is connected to the wiring nut (22) and can drive the wiring nut (22) to rotate within the wiring receiving groove (11).

8. The electromagnetic switch cover assembly for a starter motor as described in claim 1, characterized in that, Also includes: A reinforcing member is disposed on the reinforcing area (12).

9. An electromagnetic switch cover assembly for a starter motor as described in claim 8, characterized in that, The reinforcing member includes: A reinforcing patch is disposed on the side wall of the wiring receiving groove (11) in the reinforcing area (12).

10. An electromagnetic switch cover assembly for a starter motor as described in claim 8, characterized in that, The reinforcing member includes: A reinforcing member is provided within the reinforced area (12).

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