KR100705535B1 - Manufacturing process of spline shaft - Google Patents

Abstract

The present invention relates to a spline shaft processing method for forming a spline in a spline shaft, and more particularly, a material preparation process (S10) of cutting (0 step) the material into a blank 10 of an appropriate size; A piercing step (S20) of forming the hollow body 20 by forming the perforated part 11 at the center of the blank 10 (step 1); A shaping step (S30) of shaping (four steps) the first and second spline parts (32) and (42) while deforming the shape of the hollow body (3 steps); The spline forming step (S40) to form (5 steps) each of the splines (35, 45) to the spline (32, 42), in turn, pre-treatment prior to the forming step (S20) (S30) (S40) Including the step (S50), the forming step (S20) (S30) (S40) by using a cold forging method of the front extrusion method,

It unifies the processing method, reduces the weight of the shaft, minimizes the bending of the shaft during the molding process, reduces the occurrence of runout and improves the concentricity. As a result, the defect rate is reduced, thereby improving productivity and providing a spline shaft processing method having an effect of reducing manufacturing cost.

Transmission, Spline, Forward Extrusion, Cold Forging

Description

Manufacturing Process Of Spline Shaft}

1 is a process chart showing a conventional spline shaft processing method.

Figure 2 is a perspective view of the spline shaft according to the present invention.

Figure 3 is a process chart showing a spline shaft processing method of the present invention.

4 is a view showing a material formed in step 0 of the present invention.

5A is a cross-sectional view showing one step of the present invention.

5B is a cross-sectional view showing two stages of the present invention.

6A is a cross-sectional view showing three stages of the present invention.

6B is a cross-sectional view showing four stages of the present invention.

7 is a cross-sectional view showing five steps of the present invention.

Explanation of symbols on the main parts of the drawings

(All symbols shown in the drawings of the present invention)

10: blank 11: punching 12: extended punching 13: flash

20, 21, 22, 23: hollow body 30: first upper mold 31: second upper mold

32: first spline portion 33: third upper portion 34: third spline portion

35: first spline 40: first lower die portion 41: second lower die portion 42: second spline portion

43: third lower die 44: fourth spline portion 45: second spline

P1, P3, P5, P7: Insert Punch P2, P4, P6: Auxiliary Punch E1, E2, E3: Drawout Pin

D1 to D11: Die PP1, PP2, PP3, PP4: Pressure plate

The present invention relates to a spline shaft processing method for forming a spline in a spline shaft.

The cold forging method of the forward extrusion method is used to cut the material into blanks of the appropriate size, form a hollow body by drilling the center portion, and simultaneously form the splines on two or more splines formed in the longitudinal direction while deforming the shape. It relates to a spline shaft processing method.

In general, the transmission is installed between the clutch and the propulsion shaft serves to increase or decrease the rotational force of the engine according to the change in the driving state of the vehicle, and also has a reversing device for reversing the vehicle. In such a transmission, the spline shaft engaged with the gear forms a spline by hobbing or rolling.

1 is a process diagram showing a conventional spline shaft processing method, referring to FIG. 1, the spline shaft is a material preparation step (S1) of appropriately cutting the length of a material to be processed, and a centering step of pinching the prepared material to a turning machine. (S2), the spline is in the spline shaft while the turning step (S3) to form the spline portion at the designated position through the centering step, the rolling step (S4) to form the spline by repeated pressing on the spline portion Is formed.

As described above, when splines are formed from round rod materials through machining methods such as turning and rolling, the shaft itself is heavy, and it is difficult to accurately specify the center of the shaft. Excessive run-outs cause the shaft to lose concentricity. This failure leads to a decrease in productivity and an increase in manufacturing cost.

Accordingly, the present invention created to solve the above problems, unlike the conventional processing method of forming a spline through a processing method such as turning and rolling processing with a round bar material using a cold forging method of the front extrusion method By cutting the raw material into blanks of appropriate size, perforating the central part to form a hollow body, and simultaneously forming the spline in two or more spline parts formed in the longitudinal direction while deforming the shape,

It unifies the processing method, reduces the weight of the shaft, minimizes the bending of the shaft during the molding process, reduces the occurrence of runout and improves the concentricity. As a result, the object of the present invention is to provide a spline shaft processing method in which a defect rate is reduced to improve productivity and reduce manufacturing costs.

In order to achieve the above object, the present invention provides a material preparation process (S10) of cutting the material into blanks of appropriate size (step 0); A piercing process (S20) of forming a hollow body (step 2) by forming a perforated part in the center of the blank (step 1); A shaping step (S30) of shaping the first and second spline parts (four steps) while deforming the shape of the hollow body (three steps); The spline is sequentially subjected to a spline molding step (S40) of forming splines (step 5), respectively, and includes a pretreatment step prior to the molding step.

In order to achieve the above object, the molding process in the present invention is preferably to use the cold forging method of the front extrusion method.

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

FIG. 2 is a perspective view of a spline shaft according to the present invention. Referring to FIG. 2, the spline shaft is formed in a cylindrical shape through which a central portion thereof is opened to an appropriate size and constitutes multiple stages.

That is, the second spline 45 is formed on the fourth hollow spline portion 44 of the hollow cylindrical shape, and the third hollow portion 43 of the hollow cylindrical shape having an outer diameter extended than the outer diameter of the fourth spline portion 44 is formed. Configure. Here, the outer diameter of the fourth spline portion 44 and the large diameter of the second spline 45 (the diameter of the circle circumscribed to the mountain of the spline) are the same.

The first spline 35 having the same small diameter (diameter of the circle inscribed in the valley of the spline) is formed with the outer diameter of the third lower die 43, and has an outer diameter extended than the large diameter of the first spline 35 A hollow cylindrical third spline portion 34 is formed. Moreover, the 3rd shape part 33 which has the outer diameter extended from the outer diameter of the said 3rd spline part 34 is comprised.

The perforated part 11 formed inside the 4th spline part 44, the 3rd lower part 43, the 1st spline 35, and the 2nd spline part 34 is the same, and the 3rd upper part 33 is the same. The expansion perforation part 12 formed inside of is extended than the perforation part 11 (not shown).

3 is a process diagram showing a spline shaft processing method of the present invention, referring to FIG. 3, the spline shaft processing method includes a material preparation process (S10), a piercing process (S20), a molding process (S30), and a spline molding process ( S40), and includes a pretreatment process (S50) prior to molding the material.

In other words, the material to be processed is cut into blanks of a suitable size (step 0) to form a perforated part on the blank (step 1) to form a pipe-shaped hollow body (step 2). The hollow body is deformed into the shape of the spline shaft (step 3), and a spline part is formed at a predetermined position (step 4), and the spline is molded (step 5).

In the pretreatment process (S50), spheroidizing annealing, shot peening, and bond treatment are performed.

Spherical annealing is a process of spheroidizing the carbide of the material, the hardness is lowered, plastic processing, such as cold forging operation is easy and mechanical properties are improved.

Shot peening is a process of spraying hardened shots on the surface of the material to polish the surface of the workpiece to eliminate micro cracks, to impart residual compressive stress to the material, to prolong fatigue life, and to increase tensile strength. And other mechanical properties.

Bond treatment is to coat the surface of the material to prevent metal contact between the material and the mold during press molding, and has a function to lubricate.

4 is a view showing a material formed in step 0 of the present invention, referring to FIG. 4, the left view is a perspective view of the blank 10, and the right view is a longitudinal cross-sectional view of the blank 10. The round bar is cut into blanks 10 of appropriate size, and cylindrical blanks 10 of approximately 68 mm in diameter and 76 mm in length are prepared.

In each of the molding processes from step 1 to step 5 below, an insert punch and an auxiliary punch, various dies, and a cold extrusion forging method using a front extrusion method using a pressure plate and a drawing pin are used.

5A is a cross-sectional view showing a first step of the present invention. Referring to FIG. 5A, the left side view is a cross-sectional view in which the perforated part 11 is formed on the blank 10 by a forward extrusion method in a forging machine. It is sectional drawing of the blank 10 in which the study 11 was formed.

The blank 10 is pressurized using the insert punch P1 in the forging machine to form the perforations 11 at the center of the blank 10 and the diameter of the die D1 is within the allowable tolerance of 0.2 mm within the blank 10. It is in contact with the inner surface of the die (D1) and the pressure plate (PP1) while increasing the diameter and length of the.

Figure 5b is a cross-sectional view showing a two-stage of the present invention, referring to Figure 5b, the left view is a cross-sectional view in which the flash 13 is generated while the perforated portion 11 is formed in the forging machine in the front extrusion method, the central view Is a sectional view of the blank 10 in which the flash 13 generate | occur | produced, and the right figure is a sectional view of the hollow body 20 from which the flash 13 was removed.

As the first step proceeds, the blank 10 is flashed to the hole of the pressure plate PP1 as the insert punch P1 presses, and the diameter of the die D1 is within the allowable tolerance of 0.2 mm within the blank 10. The diameter and length of the C1 increase in contact with the die D1 and the pressure plate PP1. The flash 13 is removed to form a hollow body 20 having an outer diameter A1 of 68.4 mm, an inner diameter B1 of 33.4 mm, and a central portion of 93.7 mm in length.

FIG. 6A is a cross-sectional view illustrating three steps of the present invention. Referring to FIG. 6A, the upper view shows the first upper portion 30 and the first lower portion of the hollow body 20 in two stages in a forward extrusion manner in a forging machine. The lower part is a sectional drawing which forms the mold part 40, and the lower figure is sectional drawing of the hollow body 21 in which the 1st upper mold | type part 30 and the 1st lower mold | type part 40 were shape | molded in the hollow body 20 of two steps.

The hollow body 20 formed in the second step is inserted into the insert punch P3 and the auxiliary punch P2 inside the die D2 of the first upper die portion 30 and the die D3 of the first lower die portion 40. While being pressurized by the hollow body 21 is divided into the first upper mold 30 and the first lower mold 40.

The hole of the pressure plate PP2 is provided with a drawing pin E1, and is pressurized from the right side to separate the hollow body 21 in which the molding is completed in step 3 from the dies D2 and D3.

The outer diameter A1 of the hollow body 20 formed in the second step increases to the outer diameter A2 of the first upper mold part within an allowable tolerance of 0.1 mm in the die D2 of the first upper mold part 30, and the first lower mold part (40) The outer diameter C1 of the first lower die portion 40 is formed while deforming along the left inclined surface of the die D3 in the die D3.

The inner diameter B1 of the hollow body 20 formed in the second step is reduced by within the tolerance 0.1mm while being pressed by the insert punch P3 and the auxiliary punch P2, so that the hollow body 21 formed in the third step The inner diameter B2 is formed.

FIG. 6B is a cross-sectional view showing the four steps of the present invention. Referring to FIG. 6B, the upper view shows the first and second spline portions 32 on the hollow body 21 formed in the three steps by the forward extrusion method in the forging machine. (42) is a cross-sectional view and the lower drawing is a cross-sectional view of the hollow body 22 in which the first and second spline portions (32) and (42) are formed on the hollow body (21) in three stages.

The hollow body 21 formed in step 3 includes a die D4 of the second upper die portion 31, a die D5 of the first spline portion 32, a die D6 of the second lower die portion 41, and a second spline. The first upper die portion 30 is the second upper die portion 31 and the first spline portion 32 while being pressed by the insert punch P5 and the auxiliary punch P4 in the portion 42 in which the die D7 is coupled in sequence. ), The first lower mold part 40 forms a hollow body 22 which is simultaneously deformed into the second lower mold part 41 and the second spline part 42. An expansion punching part 12 is formed at the same time by the insert punch P5 in which the perforating part 11 diameter B2 extends to the predetermined size B5 inside the second upper mold part 31.

A hole of the pressure plate PP3 is provided with a drawing pin E2 and pressurized from the right side to separate the hollow body 22 formed in step 4 from the dies D4, D5, D6, and D7.

The outer diameter A2 of the first upper mold part 30 increases to the outer diameter A3 of the second upper mold part 31 within 0.2 mm of the allowable tolerance in the die D4 of the second upper mold part 31, and again the first diameter. The outer diameter C4 of the first spline portion 32 is formed while deforming along the left inclined surface of the spline portion 32 die D5.

The outer diameter C1 of the first lower mold part 40 increases from the die D6 of the second lower mold part 41 to the outer diameter C2 of the second lower mold part 41 within an allowable tolerance of 0.1 mm, and then again to the second diameter. The outer diameter C7 of the second spline portion 42 is formed while deforming along the left inclined surface of the spline portion 42 die D7.

The inner diameter B2 of the hollow body 21 formed in step 3 decreases within an allowable error of 0.1 mm while being pressed by the insert punch P3 and the auxiliary punch P2 of the hollow body 22 formed in step 4. The inner diameter B3 is formed.

FIG. 7 is a cross-sectional view illustrating five steps of the present invention. Referring to FIG. 7, the top view shows first and second splines 35 respectively on hollow bodies 22 formed in four steps by forward extrusion in a forging machine. 45 is a cross-sectional view of the hollow body 23 in which the first and second splines 35 and 45 are formed on the hollow body 22 in four stages.

The hollow body 22 formed in step 4 includes a third upper die 33 die D8, a third spline die 34 die D9, a third lower die 43 die D10, and a fourth spline. By the spline teeth 36 and 46 engraved in the die | dye D11 of the 3rd spline part 34 and the die | dye D11 of the 4th spline part 44 in the inside which the die | dye D11 coupled in order. The first spline portion 32 deforms into the third spline portion 34 and the first spline 35, and at the same time, the second spline portion 42 turns into the fourth spline portion 44 and the second spline 45. Is deformed.

The hole of the pressure plate PP4 is provided with a drawing pin E3 and pressurized from the right side to separate the hollow body 22 in which the molding is completed in step 5 from the dies D8, D9, D10 and D11.

The outer diameter A3 of the second upper mold 31 increases to the outer diameter A4 of the third upper mold 33 within an allowable tolerance of 0.1 mm in the die D8 of the third upper mold 33. The outer diameter C4 of the first spline portion 32 deforms along the left inclined plane of the die D9 of the third spline portion 34 to the outer diameter C5 of the third spline portion 34 within an allowable tolerance of 0.1 mm. Then, the first spline 35 having a large diameter smaller than the outer diameter C5 of the third spline portion 34 is formed.

The outer diameter C2 of the second lower mold part 41 increases from the die D10 of the third lower mold part 43 to the outer diameter C3 of the third lower mold part 43 within an allowable tolerance of 0.1 mm. It is the same as the small diameter of the spline 35.

The second spline portion 42 is deformed along the left inclined surface of the die D11 of the fourth spline portion 44 and has the same large diameter as the outer diameter C7 of the second spline portion 42. To form.

In the hollow body 21 formed in step 4, the inner diameters B3 and B5 of the perforated part 11 and the extended perforated part 12 are pressurized by the insert punch P3 and the auxiliary punch P2 while having a tolerance of 0.1. It decreases within mm to form the inner diameters B4 and B6 of the hollow body 23 formed in step 5.

As a result, the total length is 244.6 mm, the outer diameter A4 of the third upper die 33 is 68.8 mm, the outer diameter C5 of the third spline 34 is 50.4 mm, and the outer diameter of the third lower die 43 A spline shaft having a diameter of 45.5 mm (C3), an inner diameter B6 of the extended perforated portion 12 of 47.6 mm, and an inner diameter B4 of the perforated portion 11 of 33 mm is completed.

As can be seen from the above description, in the spline shaft processing method of the present invention, by using the cold forging method of the forward extrusion method, the raw material is cut into blanks of appropriate size, and the hollows are formed by forming the hollow body, Simultaneously molding the spline on two or more spline portions that are formed in the longitudinal direction while deforming, thereby unifying the processing method, reducing the weight of the shaft, minimizing the bending of the shaft during the molding process, and reducing runout and improving concentricity. do. As a result, the defective rate is reduced, thereby improving productivity and reducing manufacturing costs.

Claims (2)

A material preparation process of cutting the material into blanks 10 of appropriate size (step 0); A piercing step (S20) of forming the hollow body 20 by forming the perforated part 11 at the center of the blank 10 (step 1); A shaping step (S30) of shaping (four steps) the first and second spline parts (32) and (42) while deforming the shape of the hollow body (3 steps); The spline forming step (S40) to form (5 steps) each of the splines (35, 45) to the spline (32, 42), in turn, pre-treatment prior to the forming step (S20) (S30) (S40) Spline shaft processing method comprising the step (S50). The method of claim 1, The molding process (S20) (S30) (S40) is a spline shaft processing method using a cold forging method of the front extrusion method.

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