Intelligent chassis brake system gear

Abstract

The utility model provides an intelligent chassis brake system gear which comprises a metal insert and a plastic gear, the metal insert and the plastic gear are integrally formed in a plastic coating mode, the metal insert comprises a shaft body, an annular boss is arranged at the upper end of the shaft body, and arc transition faces are arranged at the intersection positions of the side face, the upper end face and the lower end face of the annular boss. A plurality of arc-shaped grooves are formed in the side face of the annular boss, and semicircular plum blossom teeth are formed between the adjacent arc-shaped grooves. During plastic coating, a mutual embedding structure is formed between the metal insert and the plastic gear through the arc-shaped grooves and the semicircular plum blossom teeth. Due to the alternate structure of the arc-shaped grooves and the semicircular plum teeth, the contact area of the metal insert and the plastic gear is increased, a mutual embedding structure is formed, and the bonding strength between the metal insert and the plastic gear is improved; the semicircular plum teeth adopt special arc design, so that corner angle parts on the contact surface of the metal insert and the plastic gear are reduced, stress generated at the joint of the metal insert and the plastic gear is avoided, and cracking is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile components, in particular to an intelligent chassis brake system gear. Background Art

[0002] The brake-by-wire system of the intelligent chassis system of automobiles is an essential technology for high-level autonomous driving. The system converts the brake signal into an electrical signal, and then brakes by the motor controller, replacing the traditional automobile braking method that relies on a series of physical connections such as mechanical or hydraulic. Plastic helical gears are the core components of the brake-by-wire system of the intelligent chassis system of automobiles. The plastic helical gears on the market are composed of two parts: plastic gears and metal helical gears. The plastic coating process is used to realize the combination of metal parts and plastic teeth, and the machining process is used to complete the tooth shape processing. The final product is completed through heat treatment and deburring processes. The process route is long, the manufacturing cost is high, and the manufacturing cycle is slow. In addition, there is internal stress in the joint part between the metal parts and the plastic teeth, and the plastic and iron parts are prone to cracking during the strength test, resulting in a high scrap rate. Utility Model Content

[0003] The technical problem to be solved by the utility model is: in order to overcome the deficiencies in the prior art, the utility model provides an intelligent chassis brake system gear.

[0004] The technical solution adopted by the utility model to solve its technical problems is: an intelligent chassis brake system gear, including a metal insert and a plastic gear, the metal insert and the plastic gear are integrally formed by plastic overmolding, the metal insert includes a shaft body, an annular boss is provided on the upper end of the shaft body, and an arc transition surface is provided at the intersection of the side surface of the annular boss and the upper and lower end surfaces, so that the outer side of the annular boss is an arc surface structure, and a plurality of arc grooves are opened on the side surface of the annular boss, and semicircular plum blossom teeth are formed between adjacent arc grooves; when overmolding, a mutually embedded structure is formed between the metal insert and the plastic gear through the arc grooves and the semicircular plum blossom teeth.

[0005] Furthermore, the structural design of the semicircular plum blossom teeth is combined with the tooth parameters of the plastic-coated gear. The structural tooth shape: the ratio of the depth and width of the embedded plastic part: the plum blossom length / width ratio: within 0.3-0.5, the number of plum blossom teeth is greater than 20 teeth, and the ratio of the number of metal plum blossom teeth to the number of plastic-coated teeth is controlled within 1.3-2 to ensure that there is sufficient axial pull-off force and reduce the residual stress value caused by the different hot and cold shrinkage rates of different materials to less than 50-35Mpa.

[0006] The alternating structure of arc grooves and semicircular plum blossom teeth increases the contact area between the metal insert and the plastic gear, and forms a mutually embedded structure, which improves the bonding strength between the two. The semicircular plum blossom teeth adopt a special arc design to reduce the angular areas on the contact surface between the metal insert and the plastic gear, thereby avoiding the stress generated at the junction of the two and preventing cracking.

[0007] Furthermore, a base circle is formed at the annular boss at the root of the semicircular plum blossom tooth, and on the base circle, the central angle α of the semicircular plum blossom tooth is 1.5-2.5 times the central angle β of the arc groove.

[0008] Further preferably, a base circle is formed at the annular boss at the root of the semicircular plum blossom tooth, and on the base circle, a central angle α subtended by the semicircular plum blossom tooth is twice a central angle β subtended by the arc groove.

[0009] Specifically, in order to achieve power transmission, a helical rack is provided on the shaft body below the annular boss. The metal helical teeth (i.e., metal inserts) mesh the rotational motion with the helical rack and assist the hydraulic system in providing sufficient clamping force for the brake caliper.

[0010] Furthermore, the plastic gear is a helical gear, and the inclination angle of the teeth is 10°.

[0011] The beneficial effects of the utility model are as follows: the intelligent chassis brake system gear provided by the utility model optimizes the metal and plastic combining structure and creates an original arc plum blossom structure design. The combining strength of the arc metal and the plastic teeth is improved, the metal insert processing efficiency is improved, the assembly yield is improved, and the tooth shape accuracy meets the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0013] Figure 1 It is a structural schematic diagram of the gear of the intelligent chassis brake system of the utility model.

[0014] Figure 2 It is a schematic diagram of the three-dimensional structure of the metal insert.

[0015] Figure 3 It is a schematic diagram of the side structure of the metal insert.

[0016] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure at point A in the middle.

[0017] Figure 5 It is a schematic diagram of the top view structure of the metal insert.

[0018] Figure 6 It is a schematic diagram of the three-dimensional structure of a plastic gear.

[0019] In the figure: 1. metal insert, 11. shaft body, 12. annular boss, 13. arc transition surface, 14. arc groove, 15. semicircular plum blossom teeth, 16. helical rack, 2. plastic gear, 21. concave-convex structure, 3. base circle. DETAILED DESCRIPTION

[0020] The present invention is now described in further detail in conjunction with the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not adopted in a restrictive sense, and the scope of the subject matter for which protection is sought is limited only by the attached claims and their equivalents.

[0021] like Figure 1-Figure 6 As shown, a gear of an intelligent chassis brake system of the utility model comprises a metal insert 1 and a plastic gear 2, wherein the metal insert 1 and the plastic gear 2 are integrally formed by plastic coating, wherein the metal insert 1 comprises a shaft body 11, wherein an annular boss 12 is provided at the upper end of the shaft body 11, and a helical rack 16 is provided on the shaft body 11 below the annular boss 12. A circular arc transition surface 13 is provided at the intersection of the side surface of the annular boss 12 and the upper and lower end surfaces, so that the outer side of the annular boss 12 is an arc surface structure, and a plurality of arc grooves are provided on the side surface of the annular boss 12, and semicircular plum blossom teeth 15 are formed between adjacent arc grooves 14; during plastic coating, a mutually embedded structure is formed between the metal insert 1 and the plastic gear 2 through the arc grooves 14 and the semicircular plum blossom teeth 15, and a concave-convex structure 21 matching the semicircular plum blossom teeth 15 is formed on the inner wall of the plastic gear 2. The annular boss 12 at the root of the semicircular plum blossom teeth 15 forms a base circle 3. On the base circle 3, the center angle α of the semicircular plum blossom teeth 15 is 1.5-2.5 times the center angle β of the arc groove 14. In this embodiment, α is preferably 12° and β is 6°, that is, α is twice β. The plastic gear 2 is a helical gear, and the inclination angle of the teeth is 10°. The number of semicircular plum blossom teeth 15 can be determined according to the size of the gear and the stress conditions of the actual use occasion. Its setting can refer to the outer diameter D of the annular boss 12 and the number N of the semicircular plum blossom teeth 15 to meet: to achieve the optimal combination of output shaft torque 2.7NM output and axial pull-off force 5KN and high temperature injection molding internal stress less than 50Mpa. In this embodiment, the outer diameter D of the annular boss 12 is about 33mm, and the number N of the semicircular plum blossom teeth 15 is 20, and they are evenly arranged, including but not limited to the above situation. The ratio of the depth and width of the semicircular plum blossom teeth 15 embedded in the plastic part is: the length-to-width ratio of the plum blossom is 0.4, and the number of the plum blossom teeth is 20 teeth.

[0022] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the scope of the utility model through the above description. The technical scope of this utility model is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An intelligent chassis brake system gear, characterized in that: It includes a metal insert and a plastic gear, which are integrally formed by plastic overmolding. The metal insert includes a shaft body, an annular boss is provided on the upper end of the shaft body, an arc transition surface is provided at the intersection of the side surface of the annular boss and the upper and lower end surfaces, and a plurality of arc grooves are opened on the side surface of the annular boss, and semicircular plum blossom teeth are formed between adjacent arc grooves. When overmolding, a mutually embedded structure is formed between the metal insert and the plastic gear through the arc grooves and the semicircular plum blossom teeth.

2. The intelligent chassis brake system gear according to claim 1, characterized in that: The ratio of the depth and width of the semicircular plum blossom teeth embedded in the plastic part is: the plum blossom length-width ratio: within 0.3-0.5, and the number of plum blossom teeth is greater than 20 teeth.

3. The intelligent chassis brake system gear according to claim 1, characterized in that: A base circle is formed at the annular boss at the root of the semicircular plum blossom tooth. On the base circle, the central angle α of the semicircular plum blossom tooth is 1.5-2.5 times the central angle β of the arc groove.

4. The intelligent chassis brake system gear according to claim 3, characterized in that: A base circle is formed at the annular boss at the root of the semicircular plum blossom tooth. On the base circle, the center angle α of the semicircular plum blossom tooth is twice the center angle β of the arc groove.

5. The intelligent chassis brake system gear according to claim 1, characterized in that: A helical rack is provided on the shaft body below the annular boss.

6. The intelligent chassis brake system gear according to claim 1, characterized in that: The plastic gear is a helical gear, and the inclination angle of the teeth is 10°.

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