CN217234065U

CN217234065U - Triangular straight-grain bolt and processing equipment thereof

Info

Publication number: CN217234065U
Application number: CN202122252860.2U
Authority: CN
Inventors: 徐国生; 苏前; 郑琼娥
Original assignee: Shenzhen Aero Fasteners Mfg Co ltd
Current assignee: Shenzhen Aero Fasteners Mfg Co ltd
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2022-08-19
Anticipated expiration: 2031-09-16

Abstract

The utility model is suitable for a mechanical technical field provides a triangle-shaped straight line flower bolt and processing equipment thereof, triangle-shaped straight line flower bolt, include: a bolt head, a bolt shank including a first shank and a second shank, the first portion being connected between the bolt head and the second shank; the first rod part is provided with three discontinuously arranged stress parts; and the first rod part is provided with a triangular straight grain flower. Therefore, the utility model provides high reliability and stability of bolt assembly starter motor aluminum hull.

Description

Triangular straight-grain bolt and processing equipment thereof

Technical Field

The utility model relates to the technical field of machinery, especially, relate to a triangle-shaped straight line flower bolt and processing equipment thereof.

Background

In the prior art, the aluminum shell of the starting motor is assembled by assembling a bolt and pressing the bolt into the aluminum shell, assembling a part at a threaded end and finally screwing a nut to perform fastening. The existing bolt is generally designed to be assembled by adopting a round bolt, but the round bolt has many problems when being pressed into an aluminum shell. For example: the outer diameter of the straight line has upper and lower tolerance, the moment when the straight line is pressed in can change along with the change, or when the straight line is damaged, the phenomena of incomplete pressing, bending, overhigh pressing moment, alarming and the like can be caused, and the condition is that the range of the pressing moment is enlarged at present so that the straight line is not alarmed; can produce, but another problem can appear again, can press the fracture to the aluminum hull hole when the moment of impressing is too high, lead to whole motor aluminum hull to scrap, perhaps produce slight crackle, when all parts equipment back, can lead to the aluminum hull crackle slowly grow to splitting completely when carrying out motor test or using on the car, at last fastening connection inefficacy makes whole motor reprocess, scrap, the serious consequence such as traffic accident in the most serious vehicle traveles.

The original design of the bolt in the prior art is 360-degree circular straight grain pattern, the process is also rolling the straight grain pattern after cold heading, but the circular straight grain pattern bolt has various problems during client assembly, the reliability and the stability are extremely poor, such as bending, blocking, incomplete pressing, production line alarming, aluminum shell cracking caused by increased extrusion force and the like, the production beat can not completely meet the planning requirement, and the operation of staff is inconvenient; the management cost for production cost, quality processing and the like is greatly increased. Consequently the utility model discloses a current process does not change, just does the change of straight line flower bolt straight line flower shape to customer's pain point demand, changes into triangle-shaped straight line flower product by original circular straight line flower, has solved customer production card and has died, can not press the scheduling problem to the end, increases customer's satisfaction.

In summary, the existing bolt structure has obvious inconvenience and defects in practical use, so it is necessary to improve the structure.

SUMMERY OF THE UTILITY MODEL

To foretell defect, the utility model aims to provide a triangle-shaped straight line flower bolt and processing equipment thereof to improve the reliability and the stability of bolt assembly starter motor aluminum hull.

In order to realize the purpose of the present invention, the present invention provides a triangular straight-line flower bolt, including:

the head of the bolt is provided with a bolt,

a bolt shank comprising a first shank portion and a second shank portion, the first portion being connected between the bolt head and the second shank portion; the first rod part is provided with three discontinuously arranged stress parts; and the first rod part is provided with a triangular straight grain flower.

According to the triangular straight-line flower bolt, the three stress parts are uniformly distributed on the periphery of the first rod part; the two stress parts are spaced by 90 radians.

According to the triangular straight-grain flower bolt, a connecting line between any points on the three stress parts forms a triangle.

According to the triangular straight-line flower bolt, threads are arranged on the second rod part.

According to the triangular straight-grain bolt, the triangular straight-grain bolt is a bolt for assembling an aluminum shell of the starting motor; the three stress parts support the inner side surface of the assembling hole of the aluminum shell of the starting motor.

In order to realize the other object of the present invention, the present invention further provides a processing apparatus for a triangular straight-line flower bolt, comprising:

the cold heading machine is provided with a plurality of working procedure dies for cold heading the prefabricated blank into the blank of the triangular straight-line patterned bolt;

the blank comprises a bolt head and a bolt rod part; the bolt rod part comprises a first rod part and a second rod part, and the first part is connected between the bolt head and the second rod part; the first rod part is provided with three discontinuously arranged stress parts;

and the thread rolling device is used for rolling the first rod part of the blank to form a triangular straight grain.

According to the processing apparatus, the plurality of process molds include:

the first station die comprises a first station male die and a first station female die, and the first station female die is provided with a first forming cavity for roughly upsetting the blank to form a first station blank; after the first station male die and the first station female die finish the first station cold heading processing, manufacturing a first station blank;

the second station die comprises a second station male die and a second station female die, and the second station male die is provided with a second forming cavity for roughly upsetting the head end of the first station blank to form the bolt head; the second station female die is provided with a third forming cavity for carrying out first fine upsetting forming on the tail end of the first station blank to form the first rod part and the second rod part; after the second station male die and the second station female die finish second station cold heading processing, second station blanks are manufactured;

the third station male die comprises a third station male die and a third station female die, and the third station male die is provided with a fourth forming cavity for precisely upsetting the head end of the second station blank to form the bolt head; the third station female die is provided with a fifth forming cavity for carrying out secondary fine upsetting on the tail end of the second station blank to form the first rod part and the second rod part; after the third station male die and the third station female die finish third station cold heading processing, the blank is manufactured; the cross section of the blank is in a circular arc triangle shape.

According to the processing equipment, the thread rolling device is a thread rolling machine or a thread rolling plate.

According to the processing equipment, the three stress parts are uniformly distributed on the outer periphery of the first rod part; the two stress parts are spaced by 90 radians;

and a connecting line between any one point on the three stress parts forms a triangle.

And the second rod part is provided with threads.

According to the processing equipment, the triangular straight-grain bolt is a bolt for assembling an aluminum shell of the starting motor; the three stress parts support the inner side surface of the assembling hole of the aluminum shell of the starting motor.

The utility model discloses an adopt the assembly hole of the straight line flower bolt assembly motor aluminum hull of triangle-shaped that cold extrusion and thread rolling technology were produced, from this triangle-shaped straight line flower bolt only three regional position bearing pressure, other three regional positions are for keeping away empty state, so stability can be higher than 360 degrees all around atress extrusion, more can not cause the card to die, beat phenomenon such as not to the end, still reduced the extrusion force, can not cause more and extrude phenomenons such as crackle to the aluminum hull in extrusion process. The utility model provides a triangle-shaped straight line flower bolt has solved stability, reliability, assembly card of assembly line assembly and has died, the buckling, press problem point on the earth, the utility model provides a triangle-shaped straight line flower bolt assembly is through changing into triangle-shaped straight line flower product by original circular straight line flower, has solved among the prior art that customer production process adopts current bolt card dead, press not the earth scheduling problem, increases customer's satisfaction.

Drawings

Fig. 1A is a schematic view of a triangular straight-grain patterned bolt structure in an embodiment of the present invention;

FIG. 1B is a sectional view taken along line A-A in FIG. 1A;

FIG. 2A is a schematic view of an aluminum shell of a starter motor in the prior art;

fig. 2B is a schematic view of the assembly of the triangular straight-grain patterned bolt and the aluminum shell of the starting motor in the embodiment of the present invention;

fig. 3A is a schematic view of a material cutting structure for processing a triangular straight-line flower bolt according to an embodiment of the present invention;

fig. 3B is a schematic structural diagram of a first-station mold according to an embodiment of the present invention;

fig. 3C is a schematic structural diagram of a first station blank in an embodiment of the present invention;

fig. 3D is a schematic structural diagram of a second station mold in an embodiment of the present invention;

fig. 3E is a schematic structural view of a second station blank in an embodiment of the present invention;

fig. 3F is a schematic structural diagram of a third station mold in an embodiment of the present invention;

fig. 3G is a schematic structural diagram of a blank of the triangular straight-line flower bolt in the embodiment of the present invention;

FIG. 3H is a front view of FIG. 3G;

FIG. 4A is a schematic view of a processing structure of a mold shell of a triangular mold according to an embodiment of the present invention;

fig. 4B is a schematic diagram of the rough and finish machining structure of the mold insert of the triangular mold according to the embodiment of the present invention;

fig. 4C is a schematic structural diagram of rough machining and finish machining of a mold shell of the triangular mold in the embodiment of the present invention;

fig. 4D is a schematic view of an interference fit between a mold shell and a mold insert of the triangular mold according to the embodiment of the present invention;

fig. 4E is a schematic view of the bottom hole processing structure of the mold shell and the mold core of the triangular mold according to the embodiment of the present invention;

fig. 4F is a schematic view of the linear cutting structure of the triangular mold according to the embodiment of the present invention;

fig. 4G is an enlarged view of the triangular cavity of the triangular mold in the embodiment of the present invention;

fig. 5 is a schematic view of thread rolling in the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1A to 1B, in an embodiment of the present invention, a triangular straight-grain spline bolt 100 is provided, including:

the head of the bolt 10 is provided with,

a bolt shank 20 including a first shank 21 and a second shank 22, the first shank being connected between the bolt head 10 and the second shank 22; the first rod part 21 is provided with three force bearing parts 211 which are discontinuously arranged; and the first rod part 21 is provided with a triangular straight grain flower.

In this embodiment, the triangular ruled bolt 100 comprises a bolt head 10 and a bolt shank 20, the bolt shank 20 being constituted by a first shank 21 and a second shank 22, the first part being connected between said bolt head 10 and said second shank 22; optionally, the second shaft 22 is provided with a thread. The first rod part 21 is made of rod body thread rolling triangular straight grains with an arc-triangular cross section. Thus, the first rod portion 21 has three force receiving portions 211 which are discontinuously arranged; these force receiving portions 211 are actually formed by thread rolling at three vertices of a circular triangle. Therefore, the triangular straight-grain bolt 100 is a special bolt with triangular straight grains on the bolt rod, and is acted on an aluminum shell 200 of an automobile starting motor by referring to fig. 1A and fig. 1B, and is fixed together by pneumatic or hydraulic assembly by referring to fig. 2B. The triangle of the triangular straight-thread bolt 100 is processed on a cold heading forming device, and the straight thread is processed by a thread rolling device. The triangular straight-line bolt 100 needs to be assembled and pressed into the starter motor aluminum case 200, the triangular assembly is adopted firstly, finally, a part is arranged at the threaded end of the triangular straight-line bolt 100, and finally, a nut is screwed in to perform the connecting and fastening action of the two parts. The triangular assembly means that the assembly is triangular in appearance, only three angular positions are stressed during assembly, other three surfaces can be kept away from the space and are not stressed, and the stability is good when the pneumatic or hydraulic machine is assembled. Because the stability of the triangle makes the triangle not easy to deform like a quadrangle or a circle, the triangle has the characteristics of stability, firmness and pressure resistance. The steel wire drawing structure is widely applied to the three-dimensional structure like the Eiffel iron tower, the Egypt pyramid and the bridge, wherein the steel wires are drawn towards two sides in the middle of the bridge. Thereby, reliability and stability of bolt-assembling the starter motor aluminum case 200 are improved.

In the present invention, the triangular straight grain is a straight grain rolled on a triangular solid. For the triangle entity, the corner point of the triangle is not a sharp corner, but is a circular arc, and the triangle can also be called a circular arc triangle. There is also a range of angular points of the triangle that will be subject to assembly forces that will press into the holes in the locking element, see fig. 2B.

Referring to fig. 1A and 1B, in an embodiment of the present invention, three force-receiving portions 211 are uniformly distributed around the outer periphery of the first rod portion 21; the two force-bearing parts 211 are spaced by 90 radian. The three force receiving portions 211 support the inner side surface of the fitting hole of the starter motor aluminum case 200. The connecting lines between any points on the three force-bearing parts 211 form a triangle. The triangular straight-grain bolt 100 is a bolt for assembling the starter motor aluminum case 200. Referring to fig. 2A and 2B, when the triangular straight-line spline 100 is pressed into the motor aluminum case 200 during assembly, only three area positions a1, a2, a3 bear pressure and are pressed into the aluminum matrix, and the other three area positions B are in a clearance state. Because only three stress areas a1, a2 and a3 are arranged, the stability is higher than 360-degree full-circle stress extrusion, the phenomena of blockage, incapability of hitting the aluminum shell to the bottom and the like can be avoided, the extrusion force is reduced, the phenomena of cracking of the aluminum shell 200 in the extrusion process and the like can be avoided, and the rotation of the bolt in the aluminum shell 200 after extrusion can be avoided.

Therefore, the utility model discloses a cold extrusion and the assembly hole 201 of the straight line flower bolt 100 assembly motor aluminum hull of triangle-shaped that thread rolling technology produced, consequently the bolt only three regional position bears pressure, and other three regional positions are for keeping away empty state, so stability can be higher than 360 degrees all around atress extrusion, more can not cause the card to die, beat phenomenon such as not to end, still reduced the extrusion force, can not cause more and extrude phenomenons such as crackle to aluminum hull 200 in the extrusion process.

Referring to fig. 3A to 5, in an embodiment of the present invention, there is further provided a processing apparatus for a triangular straight-line spline bolt 100, including:

a cold header equipped with a plurality of process dies for cold-heading the prefabricated blank 30 into a blank of the triangular straight-line threaded bolt 100;

the blank comprises a bolt head 10 and a bolt shank 20; the bolt shank 20 includes a first shank 21 and a second shank 22, the first shank being connected between the bolt head 10 and the second shank 22; the first rod part 21 is provided with three force bearing parts 211 which are discontinuously arranged;

and the thread rolling device is used for rolling the first rod part 21 of the blank to form a triangular straight grain.

In this embodiment, the processing equipment of the triangular straight-grain bolt 100 is composed of a cold header and a thread rolling device. The cold heading machine performs cold heading processing on the prefabricated blank 30, and the cold heading processing (cold extrusion) is a processing technology for performing cold extrusion molding processing on a metal material at normal temperature to achieve relevant technological shapes and sizes. The prefabricated blank 3030 is processed into the blank 33 of the triangular straight-line bolt 100 by cold heading through cold extrusion of a plurality of process dies on a cold header, and then the first rod part 21 of the blank is processed into the triangular straight-line by thread rolling by a thread rolling device to form the triangular straight-line bolt 100.

Referring to fig. 3A to 5, in an embodiment of the present invention, the plurality of process molds include:

a first station die 40 which comprises a first station male die 41 and a first station female die 42, wherein the first station female die 42 is provided with a first forming cavity 421 for roughly upsetting the blank 30 to form a first station blank 31; after the first station male die 41 and the first station female die 42 finish the first station cold heading, a first station blank 31 is manufactured;

a second station die 50 which comprises a second station male die 51 and a second station female die 52, wherein the second station male die 51 is provided with a second forming cavity 511 for roughly upsetting the head end of the first station blank 31 to form the bolt head 10; the second station female die 52 is provided with a third forming cavity 521 for performing first fine upsetting on the tail end of the first station blank 31 to form the first rod part 21 and the second rod part 22; after the second station male die 51 and the second station female die 52 finish the second station cold heading, a second station blank 32 is manufactured;

a third station die 60 including a third station male die 61 and a third station female die 62, wherein the third station male die 61 has a fourth forming cavity 611 for fine upsetting the head end of the second station blank 32 to form the bolt head 10; the third station female die 62 is provided with a fifth forming cavity 621 for performing second fine upsetting on the tail end of the second station blank 32 to form the first rod part 21 and the second rod part 22; after the third station male die 61 and the third station female die 62 finish the third station cold heading, the blank 33 is manufactured; the cross section of the blank 33 is in the shape of a circular triangle.

In this embodiment, it is first necessary to form a bolt having a rod portion with a triangular cross section in the cold heading process, that is, the aforementioned circular arc triangle shape. The triangular straight-grain bolt 100 is finished through cold heading and thread rolling processes. Firstly, the triangular size is completed by a cold heading process, a die cavity with the triangular size needs to be manufactured by the cold heading die, and then a bolt blank with a triangular rod part is extruded and formed by a cold heading machine. And then completing the formation of the triangular straight grain by a thread rolling process, manufacturing the straight grain on a specific thread rolling die according to the process size, installing the straight grain on thread rolling equipment, and performing up-and-down circular motion to roll the first rod part 21 triangle of the cold-headed blank 33 to form the triangular straight grain. In summary, the triangular straight-grain bolt 100 is formed by extruding a rod with an arc-shaped triangular cross section into a die cavity of a die in multiple processes through a cold heading process, and rolling straight grains by a thread rolling device. This triangle is fully dimensionally assured by the cold heading die. See figure 1A for a schematic representation of the triangular ruled pattern.

For the manufacturing of a plurality of process molds, the first rod portion 21 needs to be formed by cold heading, and the processing process flow of the triangular mold of the first rod portion 21 and the processing equipment adopting the triangular straight-line flower bolt 100 to form the triangular bolt is as follows:

referring to fig. 4A to 4G, the triangular mold processing process flow is as follows:

1. referring to fig. 4A-4B, die material blanking, a die shell-hot work die steel H13, a die core-hard alloy steel G50;

2. referring to fig. 4C, the formwork roughing: the external circle and the end face of the mould shell are roughly turned, the inner hole is drilled, the external dimensions of the roughly machined mould shell are controlled according to the design, and the end part of the inner hole is not chamfered but has no burrs.

3. Heat treatment of the mould shell: heat treating the rough machined mold shell to enhance mechanical properties. This requires the formwork to have good toughness and hardness in the range of HRC45-48 because of the high impact load.

4. Referring to fig. 4B to 4C, finish machining of the mold shell and the tungsten steel mold core: finely turning an inner hole of the formwork; and grinding the outer circle and the end face of the mould shell and the tungsten steel mould core. The overall dimensions are controlled according to the design tolerance of a detailed die, the end part of an inner hole is not chamfered but not provided with burrs, the surface roughness reaches below 0.3, and no burrs are formed.

5. Referring to fig. 4D, interference fit: the finely machined formwork and the tungsten steel die core are assembled in a pressing mode through a hydraulic press, the interference magnitude is about 0.05-0.08 mm according to the requirement of size design, the roughness of a binding face is within Ra1.6, the leading-in end of the die core needs to be inverted, the taper is 1:150, the length is 10% -15% of the matching total length, and the tungsten steel die core needs to be pressed to the position of a step at the bottom of the middle of the formwork.

6. Referring to fig. 4E, drilling and grinding a bottom hole: according to the requirement of size design, grinding the tungsten steel mold core to the mold shell surface, drilling a bottom hole by using a drill with the diameter phi of 8.2, and then grinding the bottom hole to phi 8(+ 0.01/-0);

7. referring to fig. 4F to 4G, triangles are machined by wire cutting; the working principle of linear cutting is that a moving thin metal wire (copper wire or molybdenum wire) is used as an electrode wire to perform pulse spark discharge cutting and forming on a workpiece. The fine molybdenum wire is used as a tool electrode for cutting, the wire storage cylinder enables the molybdenum wire to alternately move in the forward direction and the reverse direction, and the processing energy is supplied by a pulse power supply.

8. Referring to fig. 4F to 4G, triangles are manually ground; according to the requirement of size design, diamond powder grinding and polishing paste is adopted to process an inner hole to be within the tolerance range of a triangle, then the working zone area of the binding triangle is reserved to be 0.8-1.2 mm long, the whole grinding area of the lower part of the triangle is within 0.06-0.08 mm, and the triangle demoulding during cold heading is facilitated.

The processing process flow of the triangular straight-grain bolt 100 is as follows: the cold heading forming rod part is a triangular bolt, the bolt is fed by a machine tool feeding system according to the adjusted feeding length, and the material cutting system inputs data according to the process size to cut the material to prepare a cut material 30;

a first station: a mechanical hand (a feeding clamp) of an automatic feeding system sends a sheared material, namely the prefabricated blank 30 to a first station fixed position, the prefabricated blank is pushed to a first station female die 42 direction by a first station male die 41 under the stress, and finally, the die material is extruded and formed in a first forming cavity 421 after completely entering the first station female die 42; and after the first station male die 41 and the first station female die 42 finish the first station cold heading, manufacturing a first station blank 31.

A second station: a robot arm (a feeding clamp) of the automatic feeding system sends a first station blank 31 preformed at a first station to a second station fixed position, a second station male die 51 pushes the first station blank in the direction of a second station female die 52 under stress, and finally the die material is extruded and formed in a third forming cavity 521 of the second station female die 52 and a second forming cavity 511 of the second station male die 51; and after the second station male die 51 and the second station female die 52 finish the second station cold heading process, manufacturing a second station blank 32.

A third station: the robot arm (feeding clamp) of the automatic feeding system sends the second station blank 32 preformed by the second station to the fixed position of the third station, and the third station male die 61 pushes the second station blank to the female die 62 under stress, and finally the second station blank 32 is extruded into a triangular body, namely the blank 33, in the fifth forming cavity 621 of the third station female die 62 and the fourth forming cavity 611 of the third station male die 61; after the third station male die 61 and the third station female die 62 finish the third station cold heading, the blank is manufactured; the cross section of the blank is in a circular arc triangle shape.

Finally, the first rod part 21 of the blank 33 is threaded by a thread rolling device to form a triangular straight grain. Optionally, the thread rolling device is a thread rolling machine or a thread rolling plate. The thread rolling is a processing method for rolling the two screw plate dies on the circumference of a blank to form the upper shape of the screw plate die when the two screw plate dies move relatively. The screw plate is used for two square templates on the thread rolling machine, is divided into two parts, namely a long part and a short part, the long part is a static plate and the short part is a movable plate, and the extruded shape is used for extruding and forming the screw thread by the screw thread.

Referring to fig. 5, in an embodiment of the present invention, the straight-flower processing technique of the triangular straight-flower bolt 100 is as follows:

the thread rolling die 70 is a special tool or die for machining screw taps, threads, straight-line flowers, pineapple flowers and the like. The thread rolling die 70 has extremely high hardness, wear resistance, sufficient strength, certain impact force and strong fatigue resistance, is the most common tool for processing screws and bolts in the standard fastener industry, and is mainly formed by cold extrusion in principle, wherein the cold extrusion forming has the advantages of high production efficiency, low processing cost, high precision and strength of processed threads, good surface quality and the like, and is widely applied as shown in fig. 1A and fig. 1B.

The triangle is also finished by a customized silk plate die with straight grains, the depth and several kinds of external diameter sizes of the straight grains are calculated in advance, the circumferential length pi d/6 of the bolt is calculated to be 3.09mm, and finally the final forming area of the straight grains in the silk plate die is determined. The screw plate is made of two iron base materials with the hardness height of HRC60 or more, and is divided into a movable plate 72 and a fixed plate 71, namely a movable screw plate 72 and a fixed screw plate 71, and the straight lines of the screw plate are shaped as shown in fig. 1A and fig. 1B.

The three stress parts 211 of the finally manufactured triangular straight-grain bolt 100 are uniformly distributed on the outer periphery of the first rod part 21; the two stress parts 211 are spaced by 90 radians; the connecting lines between any points on the three force-bearing parts 211 form a triangle. The second rod portion 22 is provided with threads. The triangular straight-grain flower bolt 100 is a bolt for assembling an aluminum shell 200 of the starting motor; the three force receiving portions 211 support the inner side surface of the fitting hole of the starter motor aluminum case 200. When the triangular straight-grain bolt 100 is extruded into the motor aluminum shell 200 during assembly, only three area positions of the three stress parts 211 bear pressure and are extruded into an aluminum matrix, and the other three area positions are in a clearance state. Because of only three atress regions, so stability can be higher than 360 degrees full week atress extrudees, can not cause the card to die, can not hit phenomenon such as end, has still reduced the extrusion force, can not cause phenomenon such as the aluminium hull 200 extrusion crackle to extrusion in-process more, can not cause the extrusion back bolt to rotate in aluminium hull 200 yet.

It can be seen from the above-mentioned a plurality of embodiments, the technical scheme provided in the embodiment of the present invention mainly solves the following technical problems:

the problems of production and assembly stability, reliability, blocking, bending and incomplete pressing are solved, the bolts are arranged in the round holes, three points with triangular stress points, namely a1, a2 and a3, are stressed during assembly, and other areas B are not stressed, and the method is shown in figure 2B. After the stress area of the triangle is reduced, the triangle is evenly stressed during assembly, the phenomena of assembly blocking and incomplete assembly caused by aluminum cutting accumulation generated during extrusion of the aluminum shell 200 are avoided, the production beat is finally guaranteed, and the production efficiency is improved.

The problem that a large amount of aluminum scraps fall after the bolts and the aluminum shell 200 are assembled is solved, if the aluminum scraps are left on the aluminum shell 200 and the motor is finally installed, the whole motor is blocked, short circuit and the like are caused, the influence on 6S in a workshop and production workers is that a machine table needs to be cleaned once after 2 hours of assembly, otherwise, the aluminum scraps are mostly generated on the ground of the whole machine table, and the stress of the bolts with triangular straight patterns is only three-point areas a1, a2 and a3, and is not like a circle with the stress of a whole 360-degree circle.

Of course, the present invention can be embodied in many other forms without departing from the spirit or essential attributes thereof, and it is intended that all such modifications and variations be considered within the spirit or scope of the present invention as defined by the appended claims.

Claims

1. A triangular straight-grain bolt, comprising:

the head of the bolt is provided with a bolt,

2. The triangular ruled bolt according to claim 1, characterized in that three of the force-receiving portions are evenly distributed around the outer periphery of the first shaft portion; the interval between the two stress parts is 120 radians.

3. The triangular spline bolt of claim 1, wherein a connecting line between any one point on the three force-receiving portions forms a triangle.

4. The triangular ruled bolt of claim 1 wherein the second shank portion is threaded.

5. The triangular straight-line bolt according to any one of claims 1 to 4, wherein the triangular straight-line bolt is a bolt for assembling an aluminum shell of a starter motor; the three stress parts support the inner side surface of the assembling hole of the aluminum shell of the starting motor.

6. The utility model provides a processing equipment of triangle-shaped straight line flower bolt which characterized in that includes:

the blank comprises a bolt head and a bolt rod part; the bolt shank comprises a first shank and a second shank, the first shank being connected between the bolt head and the second shank; the first rod part is provided with three discontinuously arranged stress parts;

7. The processing tool of claim 6, wherein the plurality of process dies comprises:

the second station die comprises a second station male die and a second station female die, and the second station male die is provided with a second forming cavity for roughly upsetting the head end of the first station blank to form the bolt head; the second station female die is provided with a third forming cavity for carrying out first fine upsetting on the tail end of the first station blank to form the first rod part and the second rod part; after the second station male die and the second station female die finish second station cold heading processing, second station blanks are manufactured;

the third station male die comprises a third station male die and a third station female die, and the third station male die is provided with a fourth forming cavity for precisely upsetting the head end of the second station blank to form the bolt head; the third station female die is provided with a fifth forming cavity for carrying out secondary fine upsetting on the tail end of the second station blank to form the first rod part and the second rod part; after the third station male die and the third station female die finish third station cold heading, manufacturing the blank; the cross section of the blank is in a circular arc triangle shape.

8. The processing apparatus according to claim 6, wherein the thread rolling device is a thread rolling machine or a thread rolling die.

9. The tooling apparatus of claim 6, wherein three of said force-bearing portions are evenly distributed about an outer periphery of said first shank portion; the interval between the two stress parts is 120 radians;

And the second rod part is provided with threads.

10. The processing equipment according to any one of claims 6 to 9, wherein the triangular straight-figured bolt is a bolt for assembling an aluminum shell of a starting motor; the three stress parts support the inner side surface of the assembling hole of the aluminum shell of the starting motor.