KR101606507B1 - Out shaft forming method of steering device - Google Patents

Abstract

According to the present invention, disclosed is a method to manufacture an outer shaft of a vehicle steering device which manufactures easily the outer shaft by forging the outer shaft before heat treatment is performed to the outer shaft. The disclosed method to manufacture the outer shaft of the vehicle steering device comprises: a first forging step of forming a first forged form where a diameter of a steering shaft connection part is greater than a diameter of a gear forming part, by forming a forging material by cutting a raw material and then locating the forging material on a first forging frame, and then striking the first forging frame; a second forging step of forming a second forged form to form a first taper part between the steering shaft connection part and the gear forming part as expanding the diameter of the steering shaft connection part and the gear forming part by striking a third forging frame after locating the first forged form on the third forging frame; a third forging step of forming a third forged form to form a first position groove on an upper plane of the steering shaft connection part by locating the second forged form on the third forging frame, and then striking the third forging frame; a fourth forming step of forming a fourth forged form in order for a first combining groove to be extended and formed on the first position groove by locating the third forged form on a fourth forging frame, and then striking the fourth forging frame; a fifth forging step of forming a fifth forged form in order for a second position groove to be formed on a bottom of the first combining groove, and at the same time in order for a hanging protrusion part to be protruded on an outer surface of the steering shaft connection part by locating the fourth forged form on a fifth forging frame and then striking the fifth forging frame; and a sixth forging step of forming a sixth forging form by extending and forming a second combining groove on the second position groove by locating the fifth forged form on a sixth forging frame and then striking the sixth forging frame.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing an outer shaft of a steering apparatus for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an outer shaft of a steering apparatus for a vehicle, and more particularly, to a method of manufacturing an outer shaft of a steering apparatus for a vehicle, which can easily manufacture an outer shaft by forging the outer shaft before heat treatment.

2. Description of the Related Art Generally, a steering apparatus is a device for changing the traveling direction of a vehicle according to a driver's will, and arbitrarily changes a rotation center where a front wheel of a car rotates to assist a driver in moving the vehicle in a desired direction.

The steering apparatus includes a steering wheel, a steering shaft connected to the steering wheel, a steering column for fixing the steering shaft to the vehicle body, a gear box for converting the rotational force input from the steering shaft into a linear motion, And a tie rod coupled with the box.

The gear box is provided with a worm shaft which is connected to the rack bar of the tie rod to convert the rotational motion into linear motion.

However, the conventional worm shaft as described above has a problem that the workability is lowered because the heat treated material must be machined.

Therefore, there is a need to improve this.

On the other hand, Korean Patent Laid-Open Publication No. 10-2011-0032730 (published on Mar. 23, 2011) discloses a " spline manufacturing method of a steering shaft for a steering device ", and Korean Patent No. 10-1018045 (registered on Feb. 21 discloses a "method for manufacturing a pin outer pivot nut ".

The present invention provides a method for manufacturing an outer shaft of a steering apparatus for a vehicle, which is produced by the above-described necessity, and which can increase the production amount while reducing the amount of the base material by forging the base material before heat treatment to reduce post- It has its purpose.

In order to accomplish the above object, a method of manufacturing an outer shaft of a steering apparatus for a vehicle according to an embodiment of the present invention includes cutting a raw material to form a forging material, placing the forging material in a first forging frame, A first forging step of forming a first forging foam whose diameter is larger than the diameter of the gear forming part; and a second forging step of placing the first forging foam on the second forging frame, Forming a second forged foam so as to form a first tapered portion between the steering shaft connection portion and the gear forming portion while expanding the diameter of the second forged foam; A third forging step for forming a third forging foam so that a first seat groove is formed on the upper surface of the steering shaft connecting part by hitting the first forging foam; and a third forging step for placing the third forging foam on the fourth forging frame, Home A fourth forging step for forming a fourth forging foam so that the first engaging groove is extended; and a fourth forging step for placing the fourth forging foam on the fifth forging frame, A fifth forging step for forming a fifth forging foam so that a recess is formed on the outer surface of the steering shaft connecting part so as to protrude from the outer surface of the steering shaft connecting part; and a fifth forging step for placing the fifth forging foam on the sixth forging frame, And a sixth forging step of forming a sixth forging foam by extending the second engaging groove in the two-row groove.

In the first forging step, guide surfaces are formed in the steering shaft connecting portion and the gear forming portion so that the first forging foam is smoothly inserted into the second forging frame.

Further, in the second forging step, a tool holding groove is formed in the end face of the gear forming portion so that the second forging foam is smoothly and stably supported by the third forming tool of the third forging frame.

Further, in the fourth forging step, an intermediate portion is formed on the upper portion of the gear forming portion, and a second tapered portion is formed between the intermediate portion and the gear forming portion.

As described above, according to the method of manufacturing an outer shaft of a steering apparatus for a vehicle according to the present invention, unlike the prior art, the base material is forged before being cut and cut, So that it is possible to increase the production amount while reducing the use amount of the base material.

1 is a perspective view illustrating an outer shaft manufactured by a method of manufacturing an outer shaft of a steering system for a vehicle according to an embodiment of the present invention.
2 is a process diagram for explaining a method of manufacturing an outer shaft of a steering system for a vehicle according to an embodiment of the present invention.
3 is a cross-sectional view of a first forging frame for explaining a first forging step according to an embodiment of the present invention.
4 is a cross-sectional view of a second forging frame for explaining a second forging step according to an embodiment of the present invention.
5 is a cross-sectional view of a third forging frame for explaining a third forging step according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view of a fourth forging frame for explaining a fourth forging step according to an embodiment of the present invention.
FIG. 7 is a cross-sectional view of a fifth stage furnace frame for explaining a fifth forging step according to an embodiment of the present invention.
8 is a cross-sectional view of a sixth stage for explaining a sixth forging step according to an embodiment of the present invention.

Hereinafter, preferred embodiments of a method of manufacturing an outer shaft of a steering system for a vehicle according to the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a perspective view illustrating an outer shaft manufactured by a method of manufacturing an outer shaft of a steering system for a vehicle according to an embodiment of the present invention, FIG. 2 is a perspective view illustrating a method of manufacturing an outer shaft of a steering system for a vehicle according to an embodiment of the present invention Fig.

FIG. 3 is a cross-sectional view of a first forging frame for explaining a first forging step according to an embodiment of the present invention. FIG. 4 is a sectional view for explaining a second forging step according to an embodiment of the present invention. FIG. 5 is a cross-sectional view of a third forging frame for explaining a third forging step according to an embodiment of the present invention; FIG.

6 is a cross-sectional view of a fourth stage forging step for explaining a fourth forging step according to an embodiment of the present invention, and FIG. 7 is a view for explaining a fifth forging step according to an embodiment of the present invention. 5 is a sectional view of a fifth stage furnace frame, and Fig. 8 is a sectional view of a sixth stage furnace frame for explaining a sixth forging step according to an embodiment of the present invention.

As shown in FIGS. 1 to 8, the method for manufacturing the outer shaft of the steering apparatus for a vehicle according to the present embodiment includes a forging process for manufacturing the outer shaft 10 while minimizing the cutting process . The outer shaft 10 manufactured by the outer shaft manufacturing method according to the embodiment of the present invention is manufactured as a final product through heat treatment and cutting.

The outer shaft 10 manufactured by the method of manufacturing the outer shaft according to the embodiment of the present invention includes the steering shaft connecting portion 11, the gear forming portion 13, the first taper portion 15, (10) includes a first engaging recess (17), a central portion (19), a first engaging recess (11a), a locking recess (11b) and a second engaging recess The gear forming section 13, the first tapered section 15, the second tapered section 17, the central section 19, the first coupling groove 11a, The portion 11b and the second engaging groove 11c are formed stepwise.

To this end, a method for manufacturing an outer shaft of a steering system for a vehicle according to the present invention includes a first forging step (S10), a second forging step (S20), a third forging step (S30), a fourth forging step (S40) A fifth forging step S50, and a sixth forging step S60. When the outer shaft 10 is linearly machined by the forging method, the portion to be removed by cutting, finishing, grinding, etc. can be reduced, and the production amount can be increased while reducing the amount of the base material used.

The first forging step S10 includes cutting the raw material to prepare a forging material M and placing the forging material M in the first forging mold 100 and then blowing the first forging material 100 so that the diameter of one end is larger than the diameter of the other end The first forging foam 10a which is largely formed is formed. Here, the first forged foam 10a has the steering shaft connecting portion 11 formed at one end thereof and the gear forming portion 13 formed at the other end thereof.

The first forging step S10 includes a steering shaft connecting portion 11 and a gear forming portion 10b so that the first forging foam 10a can be smoothly inserted into the second forging frame 200 for the second forging step S20. And a guide surface (12) inclined to the portion (13) is formed.

The first forging die 100 for the first forging step S10 comprises a first die 110 and a first punch 120 for forging the forging material M, The first punch 120 strikes the forging material M so that the steering shaft connecting portion 11 and the gear forming portion 13 and the guide surface 12 are engaged with the forging material M. [ Respectively.

The first die 110 includes a first body 111 and a first fixing tool 113 and a first forming tool 115 and includes a first fixing tool 113 and a first forming tool 115, Respectively.

The first fixing tool 113 includes a first inside fixing portion 113a and a first outside fixing portion 113b and a first inside fixing portion 113a and a first outside fixing portion 113b are formed in the first body 113a, And the first foaming tool 115 is fixed to the first body 111 by being coupled to the inside of the first body 111 in order. The first fixing tool 113 has an air vent groove formed between the first inside fixing portion 113a and the first outside fixing portion 113b and the compressed air generated during forging through the air vent groove And is discharged to the outside of the die 110. In addition, the first inside fixing portion 113a and the first outside fixing portion 113b are coupled stepwise.

The first forming tool 115 is fixed to the first body 111 by a first fixing tool 113 and has a forming groove portion into which the forging material M is inserted to be molded. The first forming tool 115 includes a first inner forming portion 115a fixed by the first inner fixing portion 113a and a first inner forming portion 115b fixed by the first outer fixing portion 113b. . The first forming tool 115 is formed with an air discharge groove communicating with the air discharge groove of the first fixing tool 113 between the first inner forming portion 115a and the first outer forming portion 115b.

In addition, the first inner forming portion 115a and the first outer forming portion 115b are formed to have different hardnesses, and the inner rim portion of the first inner forming portion 115b is formed to have a different hardness from that of the first inner fixing portion 113a. Section. For example, the first inside forming portion 115a is formed of a material whose hardness is higher than the hardness of the first outside forming portion 115b.

In this way, the first forming tool 115 of the first die 110 is divided so as to facilitate disassembly and assembly, as well as to replace only a portion where abrasion occurs excessively, thereby reducing the maintenance cost .

The first die 110 further includes a first die pin 117 movably provided at the center of the first forming tool 115 so as to easily discharge the forged first forged foam 10a .

The first punch 120 includes a first main body 121 corresponding to the first die 110 and a second main body 121 provided inside the first main body 121 and adapted to be coupled to the upper end of the steering shaft connecting portion 11 of the first forged foam 10a, And a first punch pin 125 for striking the forging material M. The first punch pin 125 and the first punch pin 125 may be formed of the same material. At this time, the first punch forming member 123 may be formed of a material whose hardness is the same as the hardness of the first outside forming portion 115b.

The second forging step S20 is performed by positioning the first forged foam 10a in the second forging mold 200 and then blowing it to expand the diameter of the steering shaft connecting portion 11 and the gear forming portion 13, The second forged foam 10b is formed so that the first tapered portion 15 is formed between the connecting portion 11 and the gear forming portion 13. [

In the second forging step S20, a tool holding groove 14 is formed on the bottom surface of the gear forming portion 13 of the second forged foam 10b. This is to ensure that the second forged foam 10b, which has been molded, is smoothly and stably supported on the third forging frame 300.

The second forging die 200 for proceeding to the second forging step S20 comprises the second die 210 and the second punch 220 for forging the first forged foam 10a, When the forging material M is positioned on the die 210, the second punch 220 strikes the first forged foam 10a to form the second forged foam 10b. The second forging frame 200 is configured to flatten the guide surface 12 of the first forged foam 10a and to form the first tapered portion 15 and to form the steering shaft connecting portion 11 and the gear forming portion 13).

The second die 210 includes a second body 211, a second fixing tool 213, a second forming tool 215 and a second die pin 217, and the second fixing tool 213, And the second forming tool 215 are separately formed.

The second fixing tool 213 includes a second inside fixing portion 213a and a second outside fixing portion 213b and the second inside fixing portion 213a and the second outside fixing portion 213b include a second body fixing portion 213b, And the second forming tool 215 is fixed to the second body 211 in order.

The second fixing tool 213 has an air vent groove formed between the second inside fixing portion 213a and the second outside fixing portion 213b so that compressed air generated during forging through the air vent groove is guided to the second body 211 to the outside. In addition, the second fixing tool 213 has an inner surface of the second outer fixing portion 213b formed in an inclined shape, and is coupled with the first inner fixing portion 213a and the second outer fixing portion 213b in a stepped manner.

The second forming tool 215 includes a second inner forming portion 215a, a second intermediate forming portion 215b and a second outer forming portion 215c. The second forming tool 215 includes a second fixing tool 213, And the second forging foam 10b is inserted and forged. At this time, the second inner forming portion 215a, the second intermediate forming portion 215b, and the second outer forming portion 215c are manufactured to have different hardnesses. For example, the second inner forming portion 215a is formed such that the hardness of the second inner forming portion 215b is greater than the hardness of the second intermediate forming portion 215b and the second outer forming portion 215c, The forming portion 215c has the same hardness.

An air discharge groove communicating with the air discharge groove of the second fixing tool 213 is formed between the second inner forming portion 215a and the second intermediate forming portion 215b.

In addition, an air discharge groove is formed between the second intermediate forming portion 215b and the second outer forming portion 215c, and a second vertical air discharge groove 219 is formed on the outer surface along the longitudinal direction. The second vertical air discharge groove 219 more smoothly discharges the compressed air generated when the second forging foam 10b is forged.

On the other hand, the second die pin 217 has a groove forming protrusion 217a protruded to form a tool holding groove 14 in the second forging step S20, and the second forging foam 10b, which has been forged, So that the second forming tool 215 can move to the center of the second forming tool 215.

The second punch 220 includes a second main body 221 corresponding to the second die 210 and a second punch pin provided inside the second main body 221 and hitting the second forged foam 10b And a second pin bush 225 for guiding the second punch pin 223. When the second punch 220 hits the second forged foam 10b, the second punch pin 223 is inserted to the inside of the second main body 221 and the movement of the second punch pin 223 The second pin bush 225 is guided by the second pin bush 225.

In the third forging step S30, the second forging foam 10b, which has been formed through the second forging step S20, is positioned in the third forging mold 300, The third forged foam 10c is formed so that the first groove 16 is formed on the upper surface. In this case, forming the first groove 16 in the third forging foam 10c through the third forging step S30 is advantageous in that the first engaging groove 11a is smoothly formed in the fourth forging step S40 .

The third forging die 300 for proceeding to the third forging step S30 comprises the third die 310 and the third punch 320 for forging the third forged foam 10c, The third punch 320 strikes the second forged foam 10b to form the third forged foam 10c when the forged material M is positioned on the die 310. [ The second forging foam 10b is forged by using the third forging frame 300 to form the first seat groove 16 on the upper surface of the steering shaft connecting portion 11. [

The third die 310 includes a third body 311, a third fixing tool 313, a third forming tool 315 and a third die pin 317, and the third fixing tool 313, And the third forming tool 315 are separately formed.

The third fixing tool 313 includes a third inside fixing portion 313a and a third outside fixing portion 313b and the third inside fixing portion 313a and the third outside fixing portion 313b include a third body fixing portion 313a, And the third forming tool 315 is fixed to the third body 311. The third forming tool 315 is fixed to the third body 311 in order.

The third fixing tool 313 has an air vent groove formed between the third inside fixing portion 313a and the third outside fixing portion 313b and compressed air generated during forging through the air vent groove is formed in the third body 311, respectively. In addition, the third fixing tool 313 is formed such that the inner surface of the third outer fixing part 313b is inclined, and the third inner fixing part 313b and the third inner fixing part 313a are stepped.

The third forming tool 315 includes a third inner forming portion 315a, a third intermediate forming portion 315b and a third outer forming portion 315c, And the third forging foam 10c is inserted and forged. At this time, the third inner forming portion 315a, the second intermediate forming portion 215b, and the third outer forming portion 315c are made to have different hardnesses. For example, the third inner forming section 315a is formed such that its hardness is larger than the hardness of the third intermediate forming section 315b and the third outer forming section 315c, and the third intermediate forming section 315b and the third The forming portion 315c has the same hardness.

An air discharge groove communicating with the air discharge groove of the third fixing tool 313 is formed between the third inner forming portion 315a and the third intermediate forming portion 315b. In addition, an air discharge groove is formed between the third intermediate forming portion 315b and the third outer forming portion 315c, and a third vertical air discharge groove 319 is formed on the outer surface along the longitudinal direction. The third vertical air discharge groove 319 more smoothly discharges the compressed air generated when the third forging foam 10c is forged.

The third die pin 317 is movably provided at the center of the third forming tool 315 so that the forged third forged foam 10c can be easily discharged in the third forging step S30 .

The third punch 320 includes a third body 321 corresponding to the third die 310 and a third punch pin 323 provided inside the third body 321 and hitting the third forged foam 10c And a third pin bush 325 for guiding the third punch pin 323. When the third punch 320 hits the third forged foam 10c, the third punch pin 323 is inserted into the third main body 321, and the third punch pin 323 is moved The third pin bush 325 is guided by the third pin bush 325.

The third punch pin 323 is formed with a seat groove forming protrusion 323a for forming a first seat groove 16 on the end surface thereof.

In the fourth forging step S40, the third forging foam 10c is placed on the fourth forging mold 400, and then the first forging groove 10a is struck so that the first engaging groove 11a is extended 4 Forged foam 10d is molded. In addition, in the fourth forging step S40, the intermediate portion 19 is expanded and formed on the upper portion of the gear forming portion 13 through one blow, and the second portion 19 is formed between the intermediate portion 19 and the gear forming portion 13, The tapered portion 17 is formed.

In addition, the fourth forging step (S40) extends the diameter of the steering shaft connecting portion (11) to a long length. Since the first coupling groove 11a is formed in the steering shaft coupling portion 11, the diameter of the steering shaft coupling portion 11 can be enlarged by a volume forming the first coupling groove 11a, . In addition, the fourth forging step (S40) forms a longer length while reducing the diameter of the gear forming portion 13. [

In the fourth forging step S40, the intermediate portion 19 is expanded and formed on the upper portion of the gear forming portion 13 to easily form a complicated outer shape, 13 are clearly distinguished from each other.

The fourth forging die 400 for proceeding to the fourth forging step S40 is composed of the fourth die 410 and the fourth punch 420 for forging the fourth forged foam 10d, When the third forged foam 10c is positioned on the die 410, the fourth punch 420 hits the third forged foam 10c to form the fourth forged foam 10d. The fourth forging frame 400 is formed such that the length of the steering shaft connecting portion 11 and the gear forming portion 13 of the third forged foam 10c is longer and the first engaging hole 11a is formed 3 forged foam 10c is forged.

The fourth die 410 includes a fourth body 411, a fourth fixing tool 413, a fourth forming tool 415 and a fourth die pin 417, and the fourth fixing tool 413, And the fourth forming tool 415 are separately formed.

The fourth fixing tool 413 includes a fourth inner fixing portion 413a, a fourth intermediate fixing portion 413b and a fourth outer fixing portion 413c and includes a fourth inner fixing portion 413a and a fourth inner fixing portion 413a, The intermediate fixing portion 413b and the fourth outer fixing portion 413c are sequentially coupled to the inside of the fourth body 411 to fix the fourth forming tool 415 to the fourth body 411. [ At this time, the fourth fixing tool 413 is coupled to the fourth body 411 so that the fourth inner fixing portion 413a, the fourth intermediate fixing portion 413b, and the fourth outer fixing portion 413c are stepped, 4 inner fixing portion 413a, the fourth intermediate fixing portion 413b, and the fourth outer fixing portion 413c are formed on the inner surfaces of the fourth inner fixing portion 413a, the fourth intermediate fixing portion 413b, and the fourth outer fixing portion 413c.

The fourth fixing tool 413 is provided between the fourth inside fixing portion 413a and the fourth intermediate fixing portion 413b, between the fourth intermediate fixing portion 413b and the fourth outside fixing portion 413c, And the compressed air generated during forging through the air discharge groove is discharged to the outside through the fourth body 411. [

The fourth forming tool 415 includes a fourth inner forming section 415a, a fourth intermediate forming section 415b and a fourth intermediate forming section 415b. The fourth forming tool 415 includes a fourth fixing tool 413, (411), and the third forged foam 10c is inserted and forged. At this time, the fourth inner forming portion 415a, the fourth intermediate forming portion 415b, and the fourth outer forming portion 415c are manufactured to have different hardnesses. For example, the fourth inner forming portion 415a is formed such that its hardness is larger than the hardness of the fourth intermediate forming portion 415b and the fourth outer forming portion 415c, and the fourth intermediate forming portion 415b and the fourth outside The forming portion 415c has the same hardness.

The fourth forming tool 415 is provided between the fourth inner forming portion 415a and the fourth intermediate forming portion 415b and between the air vent groove of the fourth fixing tool 413 and the fourth intermediate forming portion 415b, An air discharge groove communicating therewith is formed. At this time, the fourth inner forming section 415a, the fourth intermediate forming section 415b and the fourth intermediate forming section 415b are fixed inside the fourth fixing tool 413 in a stepped manner. Specifically, the fourth inner forming portion 415a is fixed by the fourth inner fixing portion 413a, the fourth intermediate forming portion 415b is fixed by the fourth intermediate fixing portion 413b, The forming portion 415b is fixed by the fourth outer fixing portion 413c.

Meanwhile, the fourth die pin 417 is movably provided at the center of the fourth forming tool 415 so that the forged fourth forged foam 10d can be easily discharged from the fourth forming tool 415 .

The fourth punch 420 includes a fourth main body 421 corresponding to the fourth die 410 and a fourth punch pin 423 provided inside the fourth main body 421 and hitting the fourth forged foam 10d And a fourth pin bushing 425 and a fourth pin guiding portion 427 for guiding the fourth punch pin 423. When the fourth punch 420 hits the fourth forged foam 10d, the fourth punch pin 423 is inserted into the steering shaft connecting portion 11 through the first seat groove 16, (11a).

The fourth pin guide portion 427 is coupled to the fourth main body 421 through bolts to stably guide the movement of the fourth punch pin 423, which is longer than the third punch pin 323. It is possible to prevent the fourth punch pin 423 from being deformed or damaged when the fourth forging step S40 is performed by the fourth pin guide portion 427. [

In the fifth forging step S50, the fourth forging foam 10d is placed on the fifth forging frame 500 and then the second forging groove 18 is formed on the bottom surface of the first engaging groove 11a by blowing A locking protrusion 11b is formed on the outer surface of the steering shaft connecting portion 11 to form the fifth forged foam 10e.

In the fifth forging step S50, the steering shaft connecting portion 11 is compressed and the diameter of the first coupling groove 11a is reduced while the locking shaft portion 11b is expanded and formed in the steering shaft coupling portion 11. Also, in the fifth forging step (S50), the steering shaft connecting portion 11 is formed such that the outer diameter of the upper end portion is smaller than the outer diameter of the lower end portion with respect to the stopper portion 11b.

The fifth forging die 500 for proceeding to the fifth forging step S50 comprises a fifth die 510 and a fifth punch 520 for forging the fifth forged foam 10e, When the fourth forging foam 10d is positioned on the die 510, the fifth punch 520 strikes the fourth forged foam 10d to form the fifth forged foam 10e.

The fifth die 510 includes a fifth body 511, a fifth fixing tool 513, a fifth forming tool 515 and a fifth die pin 517, and the fifth forming tool 515, Is formed.

The fifth body 511 includes a tool fixing case 511a for fixing the fifth fixing tool 513 and the fifth forming tool 515 and a punch seating groove portion 511b for receiving the end portion of the fifth punch 520, And a fifth fixing tool 513, a fifth forming tool 515, and a fifth die pin 517 are installed therein. The tool fixing case 511a has an outer diameter and an inner diameter that are inclined so as to be easily fixed to the fifth body 511 and to stably support the fifth forming tool 515. [

The fifth fixing tool 513 is inserted into the fifth body 511 to fix the fifth forming tool 515 and is supported by the tool fixing case 511a. The fifth fixing tool 513 is formed with an air discharge groove, and compressed air generated during forging through the air discharge groove is discharged to the outside.

The fifth forming tool 515 includes a fifth inner forming portion 515a, a fifth intermediate forming portion 515b and a fifth outer forming portion 515c, and the tool fixing case 511a and the fifth fixing tool 513 fixed to the fifth body 511, and the fourth forged foam 10d is inserted and forged. At this time, the fifth inner forming portion 515a, the fifth intermediate forming portion 515b, and the fifth outer forming portion 515c are made to have different hardnesses. For example, the fifth inner forming portion 515a is formed such that its hardness is larger than the hardness of the fifth intermediate forming portion 515b and the fifth outer forming portion 515c, and the fifth intermediate forming portion 515b and the fifth The forming section 515c has the same hardness.

The fifth inner forming portion 515a is divided into two and is coupled to the fifth body 511 through a fifth fixing tool 513. [ The fifth inner forming portion 515a is divided into two so as to facilitate the discharge of compressed air generated during forging.

The fifth intermediate forming portion 515b and the fifth outside forming portion 515c are coupled to the outside of the fifth inside forming portion 515a by the tool fixing case 511a. Between the fifth intermediate forming section 515b and the fifth outside forming section 515c, an air discharge groove for discharging air is formed.

The fifth die pin 517 is movably provided at the center of the fifth forming tool 515 so that the forged fifth forged foam 10e can be easily discharged from the fifth forming tool 515 .

The fifth punch 520 includes a fifth body 521 corresponding to the fifth die 510 and a fifth punch pin 524 provided inside the fifth body 521 and hitting the fourth forging foam 10d A fifth pin guide portion 525 for guiding the fifth punch pin 523 and a fifth punch forming portion 527 for forming the fifth forged foam 10e.

The fifth punch 520 is formed with a seating protrusion 521a that is seated in the punch seating recess 511b. The fifth die 510 is minimized in flow generation when proceeding to the fifth forging step (S50) through the seating protrusion 521a.

The fifth punch pin 523 is formed with a seat hole projection 523a at its end so as to form the second seat groove 18.

The fifth guide portion 525 is movably installed in the fifth body 521 to prevent the fifth punch pin 523 from being deformed or damaged when the fifth forging step S50 is performed. The fifth guide portion 525 is exposed to the outside of the fifth punch pin 523 and the fifth punch forming portion 527 before hitting the fourth forging foam 10d and the fifth punch 520 And is inserted between the fifth punch pin 523 and the fifth punch forming portion 527 while striking the fourth forged foam 10d. This is for facilitating formation of the latching portion 11b easily and stably.

The fifth punch forming section 527 includes a punch forming member 527a for forging the fifth forged foam 10e and a fixed case 527b for fixing the punch forming member 527a to the fifth main body 521 Respectively. The upper end of the steering shaft connecting portion 11 of the fifth forged foam 10e is inserted and formed in the punch forming member 527a.

In the sixth forging step S60, the fifth forging foam 10e is placed in the sixth forging mold 600 and then the second engaging groove 11c is extended in the second seat groove 18, 6 Mold the forged foam 10f. The outer shaft 10, which is the sixth forged foam 10f formed through the sixth forging step S60, is manufactured through a backing process.

The sixth forging die 600 for proceeding to the sixth forging step S60 is composed of a sixth die 610 and a sixth punch 620 for forging the sixth forged foam 10f, When the fifth forging foam 10e is positioned on the die 610, the sixth punch 620 strikes the fifth forged foam 10e to form the sixth forged foam 10f.

The sixth die 610 includes a sixth body 611, a sixth fixing tool 613, a sixth forming tool 615 and a sixth die pin 617, and the sixth forming tool 615, Is formed.

The sixth body 611 is provided with a tool case 611a for fixing the sixth fixing tool 613 and the sixth forming tool 615. The inner surface of the tool case 611a is formed to be inclined, 615, respectively.

The sixth fixing tool 613 is inserted into the sixth body 611 to support the sixth forming tool 615 and is coupled to the sixth body 611 by the tool case 611a.

The sixth forming tool 615 includes a sixth inner forming portion 615a, a sixth intermediate forming portion 615b and a sixth outer forming portion 615c, and the tool case 611a and the sixth fixing tool 613 , And the fifth forged foam 10e is inserted and forged.

The sixth inner forming portion 615a, the sixth intermediate forming portion 615b, and the sixth outer forming portion 615c are made to have different hardnesses. For example, the sixth inner forming portion 615a is formed such that its hardness is larger than the hardness of the sixth intermediate forming portion 615b and the sixth outside forming portion 615c, and the sixth intermediate forming portion 615b and the sixth outside The forming portion 615c has the same hardness.

The sixth intermediate forming portion 615b is supported by the fifth body 511 through the sixth fixing tool 613 and the end of the sixth intermediate forming portion 615b is supported by the sixth fixing tool 613 and the sixth inner forming portion 615a do. The sixth intermediate forming portion 615b is formed with an air vent groove on the side contacting the sixth inner forming portion 615a.

The sixth intermediate forming portion 615b and the sixth outside forming portion 615c are coupled to the outside of the sixth inside forming portion 615a by the tool case 611a. Between the sixth intermediate forming portion 615b and the sixth outside forming portion 615c, an air discharge groove for discharging air is formed.

The sixth die pin 617 is movably provided at the center of the sixth forming tool 615 so that the forged sixth forged foam 10f can be easily discharged from the sixth forming tool 615 .

The sixth punch 620 includes a sixth main body 621 corresponding to the sixth die 610 and a sixth punch pin 621 provided inside the sixth main body 621 and hitting the fifth forged foam 10e A sixth pin guide portion 625 for guiding the sixth punch pin 623 and a sixth punch forming portion 627 for forming the sixth forged foam 10f.

The sixth punch pin 623 is provided with a groove engagement concave portion 625a for forming the second engagement groove 11c and is guided through the sixth guide portion 625.

The sixth guide portion 625 is movably installed in the sixth main body 621 to prevent the sixth punch pin 623 from being deformed or damaged when the sixth forging step S60 is performed. The sixth guide portion 625 is installed on the sixth main body 621 so as to be positioned between the sixth punch forming portion 627 and the sixth punch pin 623 and is configured to hatch the fifth forged foam 10e The sixth punch pin 623 and the sixth punch forming portion 627 are exposed before the sixth punch pin 623 and the sixth punch forming portion 627. When the sixth punch 620 hits the fifth forged foam 10e, And is inserted between the punch forming portions 627. This is for easily molding the second engaging groove 11c.

The sixth punch forming section 627 is coupled to the sixth main body 621 to form the outer surface of the sixth forged foam 10f.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand.

Accordingly, the true scope of protection of the present invention should be defined by the claims.

M: Forging material 10: Outer shaft
11: steering shaft connecting portion 13: gear forming portion
15: first tapered portion 17: second tapered portion
19: center portion 11a: first coupling groove
11b: stumbling portion 11c: second engaging groove
100: first forging die 110: first die
120: first punch 200: second forging frame
210: second die 220: second punch
300: third forging frame 310: third die
320: Third punch 400: Fourth forging frame
410: fourth die 420: fourth punch
500: fifth forging die 510: fifth die
520: fifth punch 600: sixth forging frame
610: Sixth die 620: Sixth punch

Claims (4)

A first forging step of cutting the raw material to form a forging material, placing the forging material in the first forging frame, and then striking the first forging foam so that the diameter of the steering shaft connecting part is larger than the diameter of the gear forming part; The first forging foam is placed in the second forging mold and then the second forging foam is formed so as to form a first tapered portion between the steering shaft connecting portion and the gear forming portion while expanding the diameter of the steering shaft connecting portion and the gear forming portion, A second forging step of forming a second step; A third forging step of placing the second forging foam in a third forging mold and then forming a third forged foam so as to form a first groove on the upper surface of the steering shaft connecting part; A fourth forging step of placing the third forged foam in the fourth forging die and then blowing to form a fourth forged foam so as to extend the first engaging groove in the first seat groove; The second forged groove is formed on the bottom surface of the first coupling groove and the second fork is formed on the outer surface of the steering shaft coupling portion so as to protrude on the outer surface of the fifth forging foam, A fifth forging step of forming a second step; And a sixth forging step of placing the fifth forging foam in a sixth forging frame and then blowing the second forging foam to form a sixth forging foam by extending the second engaging groove in the second seat groove,
Wherein the first forging step forms guide surfaces on the steering shaft connecting portion and the gear forming portion so that the first forging foam is smoothly inserted into the second forging frame,
Wherein the second forging step forms a tool holding groove in an end surface of the gear forming portion so that the second forging foam is smoothly and stably supported by the third forming tool of the third forging frame. Shaft manufacturing method. delete delete The method according to claim 1,
Wherein in the fourth forging step, an intermediate portion is formed on an upper portion of the gear forming portion, and a second tapered portion is formed between the intermediate portion and the gear forming portion.

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