阅读说明：本技术 汽车转向机用蜗轮及其制造方法 (Worm wheel for automobile steering gear and manufacturing method thereof ) 是由 夏玉洁 曹春林 许峰 程建刚 方毅明 于 2019-09-09 设计创作，主要内容包括：本发明涉及一种汽车转向机用蜗轮,属于汽车零部件技术领域,它解决了现有技术中蜗轮的扭力无法无法满足设计要求的问题。本汽车转向机用蜗轮包括外侧设有齿形的外部件、内部件以及由塑料制成的用于连接内部件与外部件的连接件,连接件采用注塑工艺成型于外部件与内部件之间,外部件内周面设有供连接件注塑时可嵌入其中的连接圈,连接圈内形成若干个周向分布的连接槽。本发明通过外部件与内部件之间通过注射成型形成连接件,实现外部件与内部件的连接,在外部件内周面设有连接圈,使得连接件注射成型后连接件能嵌入连接圈内,提高连接件与外部件之间的周向最大可承受扭矩,具有结构简单,有效提升蜗轮强度的优点。(The invention relates to a worm gear for an automobile steering gear, belongs to the technical field of automobile parts, and solves the problem that the torque force of the worm gear in the prior art cannot meet the design requirement. The worm wheel for the automobile steering gear comprises an outer part, an inner part and a connecting piece, wherein the outer side of the connecting piece is provided with a tooth form, the connecting piece is made of plastic and used for connecting the inner part and the outer part, the connecting piece is formed between the outer part and the inner part by adopting an injection molding process, the inner peripheral surface of the outer part is provided with a connecting ring which can be embedded into the connecting piece during injection molding, and a plurality of circumferentially distributed connecting grooves are formed in the. According to the invention, the connecting piece is formed between the outer piece and the inner piece through injection molding, so that the connection between the outer piece and the inner piece is realized, the inner circumferential surface of the outer piece is provided with the connecting ring, so that the connecting piece can be embedded into the connecting ring after the connecting piece is injection molded, the circumferential maximum bearable torque between the connecting piece and the outer piece is improved, and the worm gear has the advantages of simple structure and capability of effectively improving the strength of the worm gear.)

1. The worm wheel for the automobile steering gear comprises an outer part (1) with a toothed outer side, an inner part (2) and a connecting piece (3) made of plastic and used for connecting the inner part (2) with the outer part (1), and is characterized in that the connecting piece (3) is formed between the outer part (1) and the inner part (2) through an injection molding process, a connecting ring (11) which can be embedded into the connecting piece (3) during injection molding is arranged on the inner circumferential surface of the outer part (1), and a plurality of circumferentially distributed connecting grooves (12) are formed in the connecting ring (11).

2. The worm wheel for a steering gear of an automobile according to claim 1, characterized in that: the connecting ring (11) is in a grid shape, and the connecting ring (11) and the side wall of the outer part (1) form the connecting groove (12).

3. The worm wheel for a steering gear of an automobile according to claim 2, characterized in that: the connecting groove (12) comprises an upper connecting groove (121), a middle connecting groove (122) and a lower connecting groove (123).

4. The worm wheel for automobile steering gears according to claim 1, 2 or 3, characterized in that: the middle part of the outer part (1) is provided with a partition plate (13), and both sides of the partition plate (13) are provided with the connecting rings (11).

5. The worm wheel for a steering gear of an automobile according to claim 4, wherein: one side of the connecting ring (11) is positioned on the inner circumferential surface of the outer part (1), and the other side of the connecting ring is positioned on the partition plate (13), so that the longitudinal section of the connecting ring (11) is wedge-shaped, and the upper connecting groove (121), the middle connecting groove (122) and the lower connecting groove (123) are also wedge-shaped and have successively reduced depths.

6. The worm wheel for a steering gear of an automobile according to claim 5, wherein: the longitudinal section of one side of the connecting ring (11) contacted with the connecting piece (3) is arc-shaped.

7. The worm wheel for a steering gear of an automobile according to claim 6, wherein: the height of the connecting ring (11) close to the axle center side of the outer part (1) is lower than the height of the connecting ring close to the inner wall side of the outer part (1).

8. The worm wheel for automobile steering gears according to claim 1, 2 or 3, characterized in that: connecting piece (3) both sides all be equipped with along strengthening rib (31) of connecting piece (3) inner circle circumference equipartition, strengthening rib (31) by connecting piece (3) inner circle outdiffusion to outer lane, strengthening rib (31) of connecting piece (3) one side are the root form of being diverged outward by the root, and the root that is located the root form is shaping runner (32).

9. A method for manufacturing a worm wheel for an automobile steering gear is characterized by comprising the following steps:

s1, injection molding the outer part (1) by adopting a large-nozzle conical runner for feeding;

s2, turning the inner ring of the outer part (1) to enable the inner ring of the outer part (1) to form a partition plate (13);

and S3, placing the outer part (1) with the inner ring runner removed and the inner part (2) into a lower mold cavity of an injection mold, forming a connecting piece (3) by injection molding through a secondary molding technology, and connecting the outer part (1) and the inner part (2) into a whole.

10. The worm wheel for a steering gear of an automobile according to claim 9, characterized in that: in the manufacturing method of the worm wheel for the automobile steering gear, the connecting piece (3) adopts six-point feeding, and the feeding points are uniformly arranged at the root parts of the reinforcing ribs (31) in the shape of tree roots.

Technical Field

The invention belongs to the technical field of automobile parts, and relates to a worm wheel for an automobile steering gear and a manufacturing method thereof, in particular to a light worm wheel for the automobile steering gear and a manufacturing method thereof.

Background

The worm wheel for the automobile steering gear mainly comprises three parts, namely an outer part with helical teeth on the outer part, and is usually made of plastic parts for lightening the automobile; the mandrel inserted into the external part with a gear, usually a hub or a wheel shaft, is made of metal parts; and a connecting portion connecting the mandrel and the outer member together, the connecting portion being generally formed by an injection molding die to integrally connect the outer member and the mandrel, and in order to further achieve a light weight of the connecting portion, reinforcing ribs are generally provided on the connecting portion to reduce the mass of the connecting portion while ensuring the connecting strength.

A multi-part gear wheel as proposed in chinese patent (granted publication No. CN104806727B) has an outer part comprising a toothed rim, an inner part and a connecting portion made of plastic for a positive interlocking connection between the inner and outer parts. Thereby, the outer member is mounted on the outer circumferential surface of the joint portion and the inner member is mounted on the inner circumferential surface of the joint portion. A plurality of notches are also arranged on two opposite main surfaces which are perpendicular to the rotating shaft and outside the connecting part. Thereby, the recesses on the first main surface of the connecting portion are arranged offset to each other in the radial direction and/or in the circumferential direction of the rotation axis with respect to the recesses on the second main surface of the connecting portion, and the wall of the connecting portion has a meandering pattern.

In the above patent, by providing the recess on the connecting portion and the meandering pattern on the connecting portion, the weight of the connecting portion is reduced while the connection strength of the connecting portion is ensured, and when the worm wheel is applied to a steering gear, the torque applied to the worm wheel in the circumferential direction is an important parameter for checking the structural strength of the worm wheel of the steering gear. The connecting part is formed by injection molding, a connecting structure coated on the gear on the outer side of the inner part is formed between the connecting part and the inner part (a mandrel or a hub), and the torque borne in the circumferential rotation direction between the connecting part and the inner part can be ensured to meet the design requirement; and corresponding connection structure is not set up between the connecting portion outside and the outer part, and the outer part adopts plastics to make, and connecting portion also adopts plastics to make, and the material of two kinds of plastics is different, and the shrinkage factor is different, often leads to behind the injection moulding connecting portion poor with outer part joint strength for torsion between outer part and the connecting piece can't satisfy the design requirement.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a worm wheel for an automobile steering gear, which has high structural strength.

The purpose of the invention can be realized by the following technical scheme: a worm wheel for an automobile steering gear comprises an outer part, an inner part and a connecting piece, wherein the outer side of the outer part is provided with a tooth form, the connecting piece is made of plastic and used for connecting the inner part and the outer part, the connecting piece is formed between the outer part and the inner part through an injection molding process, a connecting ring which can be embedded into the connecting piece during injection molding is arranged on the inner circumferential surface of the outer part, and a plurality of circumferentially distributed connecting grooves are formed in the connecting ring.

When the connecting piece is injection-molded, plastic flows into the connecting grooves circumferentially arranged on the inner circumferential surface of the outer piece, the connecting parts embedded into the connecting grooves are formed, the connecting parts and the connecting grooves form fixed connection, and a limit is formed in the circumferential rotation direction of the connecting piece and the outer piece, so that the maximum bearable torque between the outer piece and the connecting piece is improved.

In the above-mentioned worm wheel for an automobile steering gear, the connecting ring is in a grid shape, and the connecting ring and the side wall of the outer member form the connecting groove.

In the above worm wheel for an automobile steering gear, the connecting groove includes an upper connecting groove, a middle connecting groove and a lower connecting groove. Because the connecting rings are in a grid shape, the grids are crossed to form a triangular upper connecting groove and a triangular lower connecting groove, and a rectangular middle connecting groove.

As another scheme, in the above worm wheel for an automobile steering gear, the connecting groove is in one or more of a honeycomb shape, a rectangular grid shape, a triangular shape or a star shape.

In the worm wheel for the automobile steering gear, the middle part of the outer part is provided with the partition plate, and the two sides of the partition plate are provided with the connecting rings. The middle part of the outer part is provided with the partition board, so that the limiting effect of the connecting piece and the outer part in the axial direction can be achieved, and the connecting piece is respectively embedded into two sides of the partition board during injection molding, so that the partition board is wrapped by the connecting piece, and the limiting effect in the axial direction is formed.

In the above worm wheel for an automobile steering gear, one side of the connecting ring is located on the inner circumferential surface of the outer part, and the other side of the connecting ring is located on the partition plate, so that the longitudinal section of the connecting ring is wedge-shaped, and the upper connecting groove, the middle connecting groove and the lower connecting groove are also wedge-shaped and have successively reduced depths.

In the worm wheel for the automobile steering gear, the longitudinal section of the connecting ring on the side contacting with the connecting piece is arc-shaped. The connecting ring is arc-shaped on one side contacting with the connecting piece, so that the contact surface of the connecting piece and the connecting ring is increased, the connection strength between the connecting piece and the connecting ring is improved, and the maximum bearable torque between the outer piece and the connecting piece is further improved.

In the above worm wheel for an automobile steering gear, the connecting ring has a height closer to the axis of the outer member than a height closer to the inner wall of the outer member. Because the longitudinal section of the connecting ring is wedge-shaped, fused plastic flows into the connecting groove of the connecting ring when the connecting piece is injected, so that the connecting ring is arranged to be of a structure with low inside and high outside, and feeding is facilitated.

In foretell automobile steering machine worm wheel, the connecting piece both sides all be equipped with along the strengthening rib of connecting piece inner circle circumference equipartition, the strengthening rib outwards spread to the outer lane by the connecting piece inner circle, the strengthening rib of connecting piece one side is the root form and outwards disperses the form by the root, and the root that is located the root form is the shaping runner. Because the connecting piece is moulded plastics and is required highly, will certainly lead to the defect such as the feeding is not enough or feeding pressure is big, consequently set up tree root column structure in connecting piece one side, make the runner position be located the strengthening rib root, adopt a plurality of feed inlets dispersion feeding on the one hand, improve feeding efficiency, on the other hand disperses the form feeding mode and makes feeding pressure loss little, flow resistance is little, and simultaneously, the runner position sets up in the strengthening rib root, after the completion is moulded plastics, carry out aftertreatment to the runner and also can not influence the structural strength of runner.

In the above worm wheel for an automobile steering gear, the inner member is made of metal and is a metal hub or a metal shaft.

In the above worm wheel for an automobile steering gear, the outer side of the outer member has a tooth form of helical teeth.

Another object of the present invention is to provide a method for manufacturing a worm wheel for an automobile steering gear, comprising the steps of:

s1, injection molding an outer part, and feeding by adopting a large-water-gap conical flow channel;

s2, turning the inner ring of the outer part to form a partition plate;

and S3, placing the outer part with the inner ring runner removed and the inner part into a lower mold cavity of an injection mold, and forming a connecting piece by injection molding through a secondary molding technology to integrally connect the outer part and the inner part.

In the manufacturing method of the worm wheel for the automobile steering gear, the connecting piece adopts six-point feeding, and the feeding points are uniformly arranged at the root parts of the reinforcing ribs in the tree root shape.

Compared with the prior art, the connecting piece is formed between the outer piece and the inner piece through injection molding, so that the outer piece is connected with the inner piece, the connecting ring is arranged on the inner circumferential surface of the outer piece, the connecting piece can be embedded into the connecting ring after the connecting piece is injection molded, the maximum circumferential bearable torque between the connecting piece and the outer piece is improved, meanwhile, the longitudinal section of one side, in contact with the connecting piece, of the connecting ring is arc-shaped, the contact surface between the connecting piece and the connecting ring is improved, the connecting strength between the connecting piece and the connecting ring is increased, the maximum circumferential bearable torque between the connecting piece and the connecting ring is further improved, and the worm gear connecting structure has the advantages of.

Drawings

FIG. 1 is a schematic front view of the present invention;

FIG. 2 is a schematic cross-sectional structural view of the present invention;

FIG. 3 is a schematic perspective view of the present invention;

FIG. 4 is a schematic top view of the outer member of the present invention;

FIG. 5 is a sectional view taken along line A-A of FIG. 4;

FIG. 6 is a sectional view taken along line B-B of FIG. 4;

FIG. 7 is an enlarged view of a portion of FIG. 5;

FIG. 8 is an enlarged partial view of FIG. 6;

fig. 9 is a simplified schematic longitudinal cross-section of a coupling ring according to the present invention.

In the figures, 1, the outer part; 11. a connecting ring; 12. connecting grooves; 121. an upper connecting groove; 122. a middle connecting groove; 123. a lower connecting groove; 13. a partition plate; 2. an inner member; 3. a connecting member; 31. reinforcing ribs; 32. and a gate.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1-3, the worm wheel for the automobile steering gear comprises an outer part 1 with a tooth profile on the outer side, an inner part 2 and a connecting piece 3 made of plastic and used for connecting the inner part 2 and the outer part 1, in the embodiment, the inner part 2 is a metal shaft made of metal, the connecting piece 3 is formed between the outer part 1 and the inner part 2 by an injection molding process, a connecting ring 11 which can be embedded into the connecting piece 3 during injection molding is arranged on the inner circumferential surface of the outer part 1, a plurality of circumferentially distributed connecting grooves 12 are formed in the connecting ring 11, the connecting ring 11 is in a grid shape, and the connecting ring 11 and the outer part side wall form the connecting groove 12. Since the connection ring 11 is in a grid shape, the grid crosses to form an upper connection slot 121 and a lower connection slot 123 having a triangular shape, and a middle connection slot 122 having a rectangular shape.

The outer part 1 is formed by injection molding, a large-water-gap conical flow channel is adopted for feeding during injection molding, circumferential feeding is adopted, the middle part is in a closed state after molding, and a hollow structure is formed by turning; so that the inner side of the outer part 1 forms a partition 13, the partition 13 is located in the middle of the transverse section of the outer part 1, the connecting rings 11 are arranged on both sides of the partition 13, and the connecting rings 11 on both sides of the partition 13 are axisymmetrical. The middle part of the outer part 1 is provided with the partition plate 13 which can play a role in limiting the axial direction of the connecting piece 3 and the outer part 1, and the connecting piece 3 is respectively embedded into two sides of the partition plate 13 during injection molding, so that the partition plate 13 is wrapped by the connecting piece 3 to form limiting in the axial direction. When the connecting piece 3 is injection-molded, plastic flows into the connecting groove 12 arranged on the inner circumferential surface of the outer part 1 in the circumferential direction, a connecting part embedded into the connecting groove 12 is formed, so that the connecting part and the connecting groove 12 form a fixed connection, and a limit is formed in the circumferential rotation direction of the connecting piece 3 and the outer part 1, so that the maximum bearable torque between the outer part 1 and the connecting piece 3 is increased.

As shown in fig. 4 to 8, in the worm wheel for a steering gear of an automobile, the connecting ring 11 is located on one side of the inner circumferential surface of the outer member 1 and on the other side of the partition plate 13, so that the longitudinal section of the connecting ring 11 is wedge-shaped, and since the connecting ring 11 is wedge-shaped, the connecting ring 11 and the upper connecting groove 121, the middle connecting groove 122 and the lower connecting groove 123 formed on the side wall of the outer member 1 are also wedge-shaped, and the depth is reduced in sequence. The longitudinal section of the connecting ring 11 at the side contacting with the connecting piece 3 is arc-shaped, and the height of the connecting ring 11 at the side close to the axle center of the outer part 1 is lower than that at the side close to the inner wall of the outer part 1. As shown in fig. 9, which is a simplified schematic diagram of a longitudinal section of the connecting ring, the side of the connecting ring 11 contacting the connecting piece 3 is arranged in an arc shape, and compared with the straight line (shown by a dotted line), the contact surface between the connecting piece 3 and the connecting ring 11 is increased, so that the connection strength between the connecting piece 3 and the connecting ring 11 is improved, and the maximum bearable torque between the outer member 1 and the connecting piece 3 is further improved. Because the longitudinal section of the connecting ring 11 is wedge-shaped, the plastic melted into the connecting ring 3 during injection molding flows into the connecting groove 12 of the connecting ring 11, so that the connecting ring 11 is arranged to be of a structure with low inside and high outside, and feeding is facilitated.

As shown in fig. 2-3, the two sides of the connecting piece 3 are provided with reinforcing ribs 31 uniformly distributed along the circumferential direction of the inner ring of the connecting piece 3, the reinforcing ribs 31 are diffused outwards from the inner ring of the connecting piece 3 to the outer ring, the reinforcing ribs 31 on one side of the connecting piece 3 are tree-root-shaped and are diverged outwards from the root, and the root positioned in the tree-root-shaped is a forming gate 32. Because connecting piece 3 moulds plastics and requires highly, will certainly lead to the feeding not enough or defect such as feeding pressure is big, consequently set up tree root column structure in 3 one sides of connecting piece, make runner 32 position be located 31 roots of strengthening rib, adopt a plurality of feed inlets dispersion feeding on the one hand, improve feeding efficiency, on the other hand disperses the form feeding mode and makes feeding pressure loss little, flow resistance is little, and simultaneously, runner 32 position sets up in 31 roots of strengthening rib, after the completion is moulded plastics, carry out aftertreatment to runner 32 and also can not influence runner 32's structural strength.

The method for manufacturing the worm wheel for the automobile steering gear comprises the following steps:

s1, injection molding the outer part 1, feeding by adopting a large water gap conical flow channel circumference, and manufacturing the outer part 1 by adopting a nylon material;

s2, turning the inner ring of the outer part 1 to enable the inner ring of the outer part 1 to form a partition plate 13;

and S3, placing the outer part 1 with the inner ring runner removed and the inner part 2 into a lower mold cavity of an injection mold, and forming the connecting piece 3 by injection molding through a secondary molding technology to integrally connect the outer part 1 and the inner part 2.

Adopt six point feeding during secondary forming, and the feed point position evenly arranges the root that is located the tree root form at one side strengthening rib 31, and external connecting piece 3 adopts glass fiber reinforced nylon to make, and glass fiber reinforced nylon structural strength is high, can further promote joint strength between them and the overall structure intensity of worm wheel after connecting the shaping with interior part 2 with exterior part 1.

The connecting piece is formed between the outer piece and the inner piece through injection molding to realize the connection between the outer piece and the inner piece, the inner circumferential surface of the outer piece is provided with the connecting ring, so that the connecting piece can be embedded into the connecting ring after the connecting piece is injection molded, the circumferential maximum bearable torque between the connecting piece and the outer piece is improved, meanwhile, the longitudinal section of one side, in contact with the connecting piece, of the connecting ring is arc-shaped, the contact surface between the connecting piece and the connecting ring is improved, the connection strength between the connecting piece and the connecting ring is increased, the circumferential maximum bearable torque between the connecting piece and the connecting ring is further improved, and the worm gear connecting structure has the advantages. The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.