CN210160342U

CN210160342U - Rotary forging die for motor hollow shaft

Info

Publication number: CN210160342U
Application number: CN201920979753.XU
Authority: CN
Inventors: 方飞松; 肖勇; 周财山; 杨科
Original assignee: Chongqing Construction Industry (group) Co Ltd
Current assignee: Chongqing Construction Industry (group) Co Ltd; Chongqing Jianshe Industry Group Co Ltd
Priority date: 2019-06-27
Filing date: 2019-06-27
Publication date: 2020-03-20
Anticipated expiration: 2029-06-27

Abstract

The utility model provides a swaging die for motor hollow shaft, including the mould back end, the mould back end is equipped with the forging face, the forging face is including preforging constriction zone and finish forging plastic district, the preforging constriction zone is the straightway, and bilateral symmetry arranges and is 110 ~ 140 contained angles, the finish forging plastic district is the circular arc section, sets up between symmetrical arrangement's straightway, and two straightways of symmetrical arrangement are tangent with the circular arc section respectively. The utility model discloses a to the design optimization of swaging die structure and key parameter, can show to reduce and forge the defect, not only be applicable to the design of motor hollow shaft class product swaging die among the electric automobile, also can be used to the design of diameter 50-100mm, hollow tube class swaging die of wall thickness 7-18 mm.

Description

Rotary forging die for motor hollow shaft

Technical Field

The utility model relates to a mold design field specifically is a rotary swaging die for motor hollow shaft.

Background

The rotary forging (rotary forging) is a technological process for precisely forming pipe fittings, bar stock and other parts, the forging hammers are uniformly distributed around the part to be processed along the circumferential direction, and the forging hammers do high-frequency and small-stroke forging motion along the radial direction while rotating around the part, so that the part to be processed is accumulated to large deformation from small deformation.

The automobile industry widely applies the rotary swaging technology to a steering column and a transmission system at present, and due to the improvement of the performance of parts by the rotary swaging and the diversity of the application of the precision rotary swaging technology, the problem that a plurality of processes which cannot be processed by an original common rotary swaging machine are solved, and parts which are originally applied to solid bars can be widely replaced by pipe parts at present.

The hollow shaft of the motor is also called as a rotor shaft, is a core component for converting electric energy into kinetic energy in the electric automobile, and has the characteristics of high rotating speed, high transmission ratio, high torque and the like. The motor shaft product produced by adopting the rotary forging technology can realize the characteristics of 100 percent hollowing, more than 85 percent material utilization rate, good dynamic balance and the like, but the diameter of a blank tube of a hollow shaft usually reaches 70mm-100mm, the wall thickness reaches 10mm-15mm, the rotary forging difficulty is very high, the metal fluidity is poor during forging, folds and cracks are easy to appear in the forging process, and the product performance and the production efficiency can be greatly influenced.

SUMMERY OF THE UTILITY MODEL

To the defect that exists among the prior art, the utility model provides a swaging die for motor hollow shaft, through the design optimization to swaging die structure and key parameter, can show the forging defect when reducing the forging, promote the manufacturability of this type of product processing.

A swaging die for motor hollow shaft, including the mould back end, the mould back end is equipped with the forging face, the forging face includes preforging constriction zone and finish forging plastic district, the preforging constriction zone is the straightway, bilateral symmetry arranges and is 110 ~ 140 contained angles, the finish forging plastic district is the circular arc section, sets up between symmetrical arrangement's straightway, two straightways of symmetrical arrangement are tangent with the circular arc section respectively.

Furthermore, the diameter of the arc section is the allowance of increasing the diameter size of the forged hollow shaft by 3-6 mm. The forging difficulty during forging is avoided to be increased due to the fact that the diameter allowance of the circular arc section is too large.

Further, the included angle of the symmetrically arranged straight line segments is 120 degrees. The precision of the precision forging size is improved and the forging defect is prevented under the condition of improving the metal fluidity.

Further, the surface of the forging surface is polished, and the roughness after polishing is Rz 0.2-0.4. The friction force between the rotary swaging die and the material is reduced, the flowing difficulty of the material is reduced, and the vibration value of equipment and the risk of material tissue defects are reduced.

Further, the surface roughness of the forging surface is Rz 0.3.

The utility model has the advantages that:

1. the forging surface structure of the rotary forging die is divided into a preforging contraction area and a finish forging shaping area by improving the forging surface structure of the rotary forging die, the preforging contraction area is formed by straight line segments which are arranged in bilateral symmetry and distributed at a certain included angle, and in the forging forming process, the arc surface of a blank is firstly in line contact with the straight line segments, so that the contact area in the rotary forging process is reduced to the maximum extent, the metal flowing difficulty is effectively reduced, and the metal fluidity is improved;

2. the precision forging shaping area is formed by arc sections, the arc sections are arranged between the two straight sections and are tangent to the two straight sections, the flowability of materials can be improved, the problem that the materials are difficult to flow or abnormal due to a die in the process from the pre-forging area to the precision forging area is solved, and the size precision and the surface roughness of the forged parts are improved;

3. the two straight line segments form a certain included angle, so that the precision of the precision forging size is improved and the forging defect is prevented under the conditions of reducing the forming difficulty and improving the metal fluidity;

4. the flow direction of the metal is guided by the arc section, so that the shaping precision and the surface quality of the precision forging area can be improved, and the problem of cracks after inner hole wrinkles and internal stress are concentrated is solved.

5. The application range is wide, and the rotary swaging hammer is not only suitable for designing rotary swaging hammers for hollow shaft products of motors in electric vehicles, but also suitable for designing rotary swaging hammers for products with larger diameters and thicker pipe walls.

Drawings

FIG. 1 is a schematic structural view of a hollow shaft product of a motor;

FIG. 2 is a rotary swaging view of a hollow shaft motor product;

FIG. 3 is a front cross-sectional view of the swaging die;

FIG. 4 is a left side view of the swaging die;

in the drawings: 1-rotary swaging die, 101-forging surface, 102-straight line segment and 103-circular arc segment.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the accompanying drawings.

In the present embodiment, the terms "upper", "lower", "left", "right", "front", "rear", "upper end", "lower end", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description, but do not indicate or imply that the designated device or element must have a specific orientation, be constructed in a specific orientation, or be operated, and thus, should not be construed as limiting the present invention.

A swaging die for hollow shaft of motor as shown in fig. 1 to 4, including the mould back end, the mould back end is equipped with the forging face, forging face 101 includes preforging constriction region and finish forging plastic district, the preforging constriction region is straightway 102, and bilateral symmetry arranges and is 110 ~ 140 contained angles, the finish forging plastic district is circular arc section 103, sets up between the straightway 102 of symmetrical arrangement, and two straightways 102 of symmetrical arrangement are tangent with circular arc section 103 respectively, rounding off, the utility model discloses mainly to the forging face of back end in the swaging die, of course also can be applicable to all working faces of swaging die.

By adopting the structure, in the forging forming process, the straight line segment 102 in the forging surface is firstly contacted with the metal surface of the hollow shaft blank, the circular arc segment 103 is not involved in the forging, at the moment, the straight line segment 102 is actually contacted with the circular arc surface of the blank pipe, the contact area in the rotary forging process is reduced to the maximum extent, namely, the deformation of the metal is forged once, the metal flowing difficulty can be effectively reduced, the metal flowability is improved, then the precise forming of the product is realized through the circular arc segment 103, and the product precision is improved.

In this embodiment, the optimal parameters of included angles of the symmetrically arranged straight line segments are set to be 120 degrees, and the values of the angles have direct relation with the diameter of the blank pipe, but the method is not limited to this, and the values of the pre-forging size and the precision forging size can be adjusted through the change of the angles, so that the precision of the precision forging size is improved and the forging defects are prevented under the conditions of reducing the vibration of equipment and improving the metal fluidity.

In this embodiment, the forging surface of the rotary swaging die is formed by a mode that an arc section is tangent to two straight line sections, smooth transition is achieved, if the smooth transition is not achieved in the rotary swaging die manufacturing process through detection, the smooth transition is repaired by a mode of polishing a rubber grinding wheel, the flowability of a material can be improved, the problem that the material is difficult to flow or abnormal due to the die in the process from a pre-forging area to a finish forging area is solved, and the size precision and the surface roughness of a forged part are improved.

In this embodiment, the diameter size of circular arc section 103 is the hollow shaft and forges back diameter size +3 ~ 6mm surplus, can adjust the size of the initial diameter in finish forging plastic district and final diameter through setting up 3 ~ 6mm surplus, avoids the forging degree of difficulty when the too big increase of circular arc section 103 diameter surplus is forged, adopts the flow direction of circular arc section guide metal, can promote the precision and the surface quality of the regional plastic of finish forging, solves the problem that crackle appears after hole fold and internal stress are concentrated.

In the embodiment, the surface of the forging surface 101 is polished, the roughness after polishing is controlled to Rz0.2-0.4, and the optimal value is controlled to Rz 0.3, so that the friction between a rotary swaging die and a material is reduced, the flowing difficulty of the material is reduced, and the vibration value of equipment and the risk of material tissue defects are reduced.

The utility model discloses when forging man-hour, with four rotary swaging dies along circumference equipartition fixed mounting in rotary swaging machine's recess, the final structure size design of product is phi 55mm, put the volume value according to the circular arc section settlement, the diameter size of circular arc section adopts phi 60mm, select former material blank external diameter of pipe to be phi 74mm according to the structure size of product, in-process that rotary swaging die fed, when the forging circular arc value that rotary swaging die forging face constitutes reduces to phi 74mm, rotary swaging die forging face and two straightway begin to contact, two straightways and blank line contact implement to forge promptly, accelerate the flow of metal, when rotary swaging die forging face diameter reduces to phi 60mm, rotary swaging die's circular arc section begins to contact with the work piece, implement to forge under the effect of circular arc face, until reducing to product left end excircle final dimension phi 55mm in figure 2.

The rotary swaging die adopts the structural design, can finish the rotary swaging process processing of the parison tube with larger diameter and thicker tube wall, reduces the vibration value of equipment to be below 25, improves the excircle forging precision to H7 level, solves the problems that the hollow shaft products or the tube products are easy to wrinkle and crack in the forging process, is not only suitable for the design of the rotary swaging die of the hollow shaft products of the motor in the electric automobile, but also can be used for the design of the rotary swaging die of the hollow tube rotary swaging products with the diameter of 50-100mm and the wall thickness of 7-18 mm.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art; the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the scope of the embodiments of the present invention, and are intended to be covered by the claims and the specification.

Claims

1. The utility model provides a swaging die for motor hollow shaft, includes the mould back end, the mould back end is equipped with forging face, its characterized in that: the forging surface comprises a preforging contraction area and a precision forging shaping area, the preforging contraction area is straight line sections, the preforging contraction area is arranged in bilateral symmetry and forms an included angle of 110-140 degrees, the precision forging shaping area is an arc section and is arranged between the symmetrically arranged straight line sections, and the two symmetrically arranged straight line sections are respectively tangent with the arc section.

2. A swaging die for hollow shafts of electric motors according to claim 1, characterized in that: the diameter of the arc section is the allowance for increasing the diameter size of the forged hollow shaft by 3-6 mm.

3. A swaging die for hollow shafts of electric motors according to claim 1, characterized in that: the included angle of the symmetrically arranged straight line segments is 120 degrees.

4. A swaging die for hollow shafts of electric machines according to any of claims 1 to 3, characterized in that: and polishing the surface of the forging surface, wherein the roughness after polishing is Rz 0.2-0.4.

5. A swaging die of claim 4 for hollow shafts of electric motors, wherein: the surface roughness of the forging surface is Rz 0.3.