KR101720996B1 - manufacturing method for differential cup of differential assembly - Google Patents

Abstract

The present invention provides a manufacturing method for a differential cup of a differential assembly, which preferentially forms an appearance of a hub unit for a flange unit to be formed after accurately filling ribs with respect to each bending portion or an edge portion. Moreover, a plurality of flow path holes formed in the hub unit can be formed along with a CNC process to process an internal diameter of the hub unit. Therefore, with cold forging, a differential cup can be manufactured by an aluminum material, and strength of the differential cup manufactured by a casting method can be obtained.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a differential method for manufacturing a differential cup using cold forging,

The present invention relates to a diffuser cup of a diffuser assembly, and more particularly to a diffuser cup of a diffuser assembly which can be manufactured by a cold forging process, To a method of manufacturing a differential cup of a differential assembly using a new method of cold forging so as to obtain a structural strength of a steel-made diffuser cup manufactured by casting.

Generally, the differential assembly is composed of a combination of a pair of side bevel gears that transmit power to the left and right wheels and a pair of pinion bevel gears that connect the side bevel gears. The left and right wheel motors of the vehicle are distributed when the power is transmitted from the drive shaft to the right and left wheels. It is a device that makes a difference and makes smooth rotation on rugged road and turning.

Since the weight of the differential case, which forms the appearance of such a differential assembly, accounts for about 35% of the weight of the entire differential device, it is not only trying to change to a lighter material such as an aluminum alloy, Various changes have been made, such as changing the method, and in this connection, there have been proposed various methods such as disclosed in Japanese Patent Application Laid-Open Nos. 10-2015-0051957, 10-2007-0120294, Registered Utility Model No. 20-0409513, -0178096, Japanese Patent Registration No. 10-1597172, Japanese Patent Application No. 10-1521852, and the like.

However, in the case of the differential cup 10 constituting the differential case (see FIG. 1), the shape of the flange 11 coupled with the diffuser cover is not easily formed by cold forging .

That is, when the material is applied to an aluminum alloy, a large number of molding defects occur due to excessive molding load, occurrence of folding of material at each step, occurrence of buckling at an unformed portion, It has not been considered at all to manufacture the differential cup 10 by using cold forging.

Of course, there may be a case where the material is applied to the aluminum alloy while performing the conventional casting and forging method, but in this case, fine pores are generated in the manufactured product, There is a possibility that cracks due to micropores are generated, and further, there is a problem that heat treatment by the internal pores is impossible.

Considering that the flow passage holes 12 passing through the periphery of the differential cup 10 are formed to pass through along the circumferential direction of the hub portion 13, It is inevitably required to perform machining by using a machining center. In this case, the manufacturing time for forming the flow hole 12 is long, and the cost is also increased.

Japanese Patent Application Laid-Open No. 10-2015-0051957 Published Patent No. 10-2007-0120294 Registration Utility Model No. 20-0409513 Registration Utility Model No. 20-0178096 Patent No. 10-1597172 Patent No. 10-1521852

It is an object of the present invention to provide a differential cup of a differential assembly, which can be manufactured by a cold forging method, The present invention also provides a method of manufacturing a differential cup of a differential assembly using a new method of cold forging so as to obtain a strength of a differential cup manufactured in a casting manner while allowing a cup to be manufactured.

In order to accomplish the above object, the present invention provides a method of manufacturing a differential cup of a differential assembly having a cup structure having a vertically penetrating cup structure, a hub portion having a plurality of flow holes formed around the hub portion, The method comprising the steps of: preparing a material for producing a diffuser cup, the diffuser cup having a flange portion configured to extend outwardly from the substrate; A hub part forming step of forming a hub part by forging the material by using a primary molding punch and a primary molding die; A flange portion forming step of forming a flange portion at an end of the hub portion using a punch for secondary molding and a die for secondary molding and bending molding the portion where the flow hole is to be formed to protrude into the inside; A piercing step in which the hub portion and the flange portion penetrate the inside of the molded workpiece up and down; And an inner diameter machining step of machining the inner diameter of the material and machining and removing a portion protruding from the inner portion of the material to thereby form a plurality of channel holes.

The hub part forming step rearwardly extrudes the upper surface of the workpiece, and the lower surface of the workpiece is forwardly extruded to form a portion where the hub part is to be formed. The inner wall surface of the primary forming die is formed by molding A primary vertical section formed vertically up and down from an end of the primary radial division; and a second vertical section formed vertically outward from the end of the primary vertical section, And a second vertical step formed vertically up and down from an end of the secondary diameter division so that the rear extruded part is vertically and vertically formed while maintaining the same thickness .

In addition, the inclination angle and height of the secondary diameter division are formed larger and higher than the inclination angle and height of the primary diameter division, and the height of the secondary vertical end is higher than the height of the primary vertical end.

The secondary molding punch includes an inner circumferential punch portion for protruding the inner peripheral surface of the hub portion and a portion where the flow hole is to be formed, and a flange-side punch portion for forming the flange portion, The inner circumferential side punch portion is formed to have an inclined structure that gradually decreases in outer diameter toward the secondary molding die, and the flange side punch portion is formed so as to extend outward from the upper end of the inner circumferential side punch portion.

The flange-side punch portion is formed at a bottom surface thereof with a primary pawl formed at an edge of the flange-side punch portion facing the inner punch portion to prevent buckling of the pawl and the primary pawl. The primary pawl is formed outside the primary pawl, And a second step for limiting the size of the outer diameter of the flange portion while being formed at a low depth are respectively formed and the secondary molding die further has a restriction step for restricting the size of the outer diameter of the flange portion So that buckling is prevented from occurring on the peripheral surface of the hub portion when the flange portion is formed.

Further, in the forming of the flange portion, a plurality of recessed portions and non-recessed portions are further formed on the surface of the flange portion so that defective molding on the peripheral side surface of the flange portion can be prevented.

As described above, the diffuser cup of the diffuser assembly manufactured by the diffuser assembly of the diffuser assembly of the present invention can be manufactured by a method in which the material made of the aluminum alloy is preferentially performed from the cold forging of the hub portion So that the molding of the rear flange portion can be performed, thereby making it possible to prevent defective molding on the hub portion.

That is, when the hub part and the flange part are molded at the same time at a time, it is possible to solve the defective forging which can not accurately fill the corner parts of the hub part by the manufacturing method of the present invention, It is possible to manufacture the differential cup and to obtain the same product reliability as the differential cup manufactured by the casting method.

Particularly, the method of manufacturing the differential cup of the differential assembly of the present invention is characterized in that after the forging of the differential cup is completed, the flow hole is not formed in the machining center but the flow hole is formed in the forging of the differential cup The CNC machining process for inner diameter machining is used to cut and remove the CNT portion, so that the manufacturing cost can be reduced and the manufacturing time can be shortened .

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view illustrating the outer structure of a differential cup of a diffractive assembly;
2 is a flow chart illustrating a method of manufacturing a differential cup of a diffractive assembly according to an embodiment of the present invention.
FIGS. 3 to 8 are diagrams for explaining a mold for molding a hub part for manufacturing a differential cup of a differential assembly according to an embodiment of the present invention, and a forging process therefor, and FIGS. 4, 6 Quot; A "," B ", and " C " in Fig. 3,
Fig. 9 is a sectional view for explaining the shape of the workpiece molded by the hub part forming metal mold
10 to 15 are diagrams for explaining a mold for forming a flange portion for manufacturing a differential cup of a diffractive assembly according to an embodiment of the present invention and a forging process therefor, and FIGS. 11, 13, Quot; D "," E ", and " F "
FIGS. 16 to 19 are diagrams for explaining the state of the material for each process formed by the differential cup manufacturing method of the differential assembly according to the embodiment of the present invention. FIG.

Hereinafter, a preferred embodiment of a method of manufacturing a differential cup of a diffractive assembly of the present invention will be described with reference to FIGS. 2 to 19 attached hereto.

For reference, the differential cup of the diffractive assembly manufactured by the manufacturing method of the present invention has a cup portion having a vertically penetrating cup structure, a hub portion having a plurality of flow holes formed around the hub portion, The structure of the differential cup is as shown in FIG. 1, which is attached hereto.

FIG. 2 is a flowchart illustrating a method of manufacturing a differential cup of a differential assembly according to an embodiment of the present invention. FIG. 3 through FIG. 8 are views illustrating a method of manufacturing a differential cup according to an embodiment of the present invention. Fig. 9 is a sectional view for explaining the shape of a workpiece molded by a hub part forming metal mold, and Figs. 10 to 20 are views for explaining a mold for forming a hub part for manufacturing a flexible cup, FIG. 15 is a state diagram for explaining a mold for forming a flange portion for manufacturing a differential cup of a diffractive assembly according to an embodiment of the present invention and a forging process therefor, and FIGS. FIG. 7 is a state diagram for describing the state of a material for each process formed by the differential cup manufacturing method of the differential assembly according to the example; FIG.

As shown in these drawings, the method of manufacturing a differential cup of a diffractive assembly according to an embodiment of the present invention is characterized in that the outer shape of the hub portion 13 is preferentially formed so that the filling of each bending portion or corner portion is accurately The plurality of flow holes 12 formed in the hub portion 13 are formed in the hub portion 13 so that the flange portion 11 is formed in the hub portion 13, ), It is possible to reduce the manufacturing cost and shorten the manufacturing time.

Before describing the embodiment of the method of manufacturing the differential cup of the differential assembly according to the embodiment of the present invention, the differential cup 10 may be manufactured by a method of forming a hub part for molding the hub part 13 Is formed by sequential forging using the mold 100 and the flange portion molding die 200 for forming the flange portion 11. [

The hub part molding metal mold 100 includes punches 110 and 120 for primary molding for forward and backward extrusion of a work 1 and a die 130 for primary molding, The forming punches 110 and 120 are composed of a top punch 110 for rearward extrusion of the work 1 and a bottom punch 120 for forward extrusion of the work 1. [

Particularly, the inner wall surface of the primary molding die 130 has a rounded end 131 formed to be rounded so that a corner side portion of the hub portion 13 is formed, and a rounded end portion 131 extending radially outwardly from the end of the rounded end 131 A first vertical edge 133 formed vertically up and down from the end of the primary diameter divider 132 and a second vertical edge 133 vertically extending from the end of the primary vertical edge 133 And a secondary vertical end 135 formed vertically upwards and downwards from the end of the secondary diameter dividing end 134. [ In other words, the plurality of inclined ends 132 and 134 and the vertical ends 133 and 135 are alternately formed, and the size thereof is gradually increased so that the rear extruded portion can smoothly be vertically and vertically To be extruded.

At this time, the inclination angle and height of the secondary mirror division 134 are larger and higher than the inclination angle and height of the primary mirror division 133, and the height of the secondary vertical section 135 is larger than the height of the primary vertical section 133 So that the portion where the primary vertical end 133 is formed can be guided to accurately guide the backward extrusion while supporting the periphery of the material 1.

The metal mold 200 for forming the flange portion is formed by forging the end portion of the hub portion 13 to which the hub portion 13 is extruded rearwardly of the molded primary workpiece 1-1 to form the flange portion 11 A punch 210 for secondary molding for molding, and a die 220 for secondary molding.

Particularly, the secondary forming punch 210 has an inner circumferential side punch portion 201 for forming an inner circumferential surface of the hub portion 13 and a portion where the flow path hole 12 is to be formed and a flange portion Side punching portion 202 for forming the inner-side punching portion 201. The inner-diameter-side punching portion 201 is formed in an inclined structure that gradually decreases in outer diameter toward the secondary molding die 220, and the flange- Side punch portion 202 is formed to have a structure extending outward from the upper end of the inner circumferential side punch portion 201.

At the inner peripheral surface of the secondary molding die 220, a portion of the peripheral surface of the primary working material 1-1 where the flow hole 12 is to be formed is pressed and projected toward the inner peripheral side of the material 1 A supporting groove 203 is formed on the outer circumferential surface of the inner circumferential side punch portion 201 for supporting a portion protruding while being pressed toward the inner circumferential side of the primary workpiece 1-1. .

The bottom surface of the flange-side punch portion 202 is formed at a corner portion facing the inner circumferential side punch portion 201 to prevent buckling of the end portion of the hub portion 13 of the primary workpiece 1-1 And is formed so as to be recessed at a lower depth than the primary one (211) and to limit the outer diameter of the flange portion (11) The secondary molding die 212 is further formed with a restriction step 222 for limiting the outer diameter of the flange portion 11 together with the secondary shoulder 212 . That is, it is possible to prevent buckling on the circumferential surface of the hub portion 13 during the molding of the flange portion 11 through the stepped structure with respect to each of the recessed portions described above, So that the flange portion 11 can be formed with an accurate thickness.

The embossing protrusion 223 is further formed on the secondary molding die 220 of the flange molding die 200.

The embossing protrusion 223 is formed by forming a plurality of recessed portions 15 and a non-recessed portion 16 on the surface of the flange portion 11 constituting the differential cup 10 so that the flange portion 11, So that it is possible to prevent defective molding on the peripheral side surface of the flange portion 11 through such a structure.

Hereinafter, a method of manufacturing a differential cup of a differential assembly according to an embodiment of the present invention will be described in detail.

First, the material 1 for manufacturing the differential cup is prepared (S100) in the initial state as shown in FIGS. 3 and 4.

The material 1 is provided in a rectangular block made of an aluminum alloy. The material 1 thus prepared is inserted into the mold 1 for primary molding of the mold 100 for molding a hub part, as shown in FIGS. 5 and 6, (130).

7 and 8 through the operation control of the primary molding punches 110 and 120 and the primary molding die 130 constituting the hub part molding metal mold 100, The forging operation for forward extrusion and rear extrusion is performed (S200), whereby the primary working material 1-1 in which the hub portion 13 is formed is manufactured.

At this time, the circumferential surface of the work 1 is supported by a portion where the primary vertical end 133 of the primary molding die 130 is formed, so that forward and backward extrusion during molding of the hub portion 13 And can be made based on a portion supported by the primary vertical end 133.

The portion of the primary molding die 130 to be extruded rearward from the work 1 during the molding of the hub portion 13 is formed by the primary diameter division 132 and the primary vertical end 133 of the primary molding die 130 After the extrusion is started, the extrusion is vertically and vertically carried out. Then, the extrusion is carried out by the second order radial division 134 and the second vertical step 135 and further extrusion is performed. 13). In particular, each corner portion constituting the hub portion 13 can be stably filled with the backward extrusion and the forward extrusion. The material condition at this time is as shown in Fig.

Next, when the primary processing material 1-1 having the hub part 13 formed by the above-described process is manufactured, the primary processing material 1-1 thus formed is inserted into the flange part 13 of the accompanying Figs. 10 and 11, Is provided to the molding die 200 to perform the operation for forming the flange portion 11 (S300).

12 and 13, in the secondary molding die 220 constituting the mold 200 for forming the flange portion, the primary working material 1-1 14 and 15, after the operation of the punch for secondary molding 210 is controlled, the flange portion 11 is formed at the end of the hub portion 13, To produce the material (1-2).

The flange portion 11 is added to the end of the hub portion 13 of the primary working material 1-1 provided in the secondary molding die 220 by the operation of the secondary forming punch 210 .

Particularly, while the flange portion 11 is being formed in the hub portion 13, the primary inclined portion 211 formed on the bottom surface of the flange-side punch portion 202 constituting the secondary molding punch 210, It is possible to prevent the circumferential surface of the flange portion 11 from buckling and to restrict the outer diameter of the flange portion 11 by the limiting tangs 222 of the secondary tangs 212 and the die 220 for secondary molding. It is possible to prevent the phenomenon that the size is exceeded by the set size or more and the defect that the thickness becomes thin.

When the flange portion 11 is formed, the projecting end 221 formed on the inner peripheral surface of the secondary molding die 220 and the projecting end 221 formed on the outer peripheral surface of the inner punch portion 201 The portion where the flow hole 12 is to be formed in the periphery of the secondary working material 1-2 is pressed against the inner circumferential side of the secondary working material 1-2 so as to protrude therefrom, As shown in Fig.

The embossing protrusion portion 223 formed on the die 220 for secondary molding of the flange portion molding die 200 allows the surface of the flange portion 11 of the secondary workpiece 1-2 to be provided with a plurality of grooves The material 15 can be sufficiently supplied to the peripheral portion of the non-indented portion 16 due to the respective recessed portions 15, so that defective molding with respect to the peripheral surface of the flange portion 11 . That is, when the embossed portion 15 is formed on the surface of the flange portion 11 by the embossing protrusion portion 223, a part of the material existing at the forming position of the embossed portion 15 is removed from the non-embossed portion 16, So that sufficient filling of the non-inflated portion 16 can be achieved.

Further, folding phenomenon that a part of the surface of the flange portion 11 is folded when the flange portion 11 is formed due to the existence of the embossed protrusion portion 223 can be prevented.

Thus, the forging operation using the above-described hub part forming mold 100 and the flange part forming mold 200 is completed and the hub part 13 and the flange part 11 and the projecting parts 14 are The molded secondary workpiece 1-2 is pierced vertically through the inside thereof (S400) and an inner diameter work for CNC machining of the inner diameter of the secondary workpiece 1-2 is performed (S500), thereby producing the third processed material 1-3.

In the embodiment of the present invention, it is proposed that the above-described piercing work and inner diameter work are performed collectively through the same CNC machining. Particularly, during the work for inner diameter machining of the third workpiece 1-3, The protruding portion (the portion where the flow hole is to be formed) protruding into the interior of the machining work 1-3 is cut off at the time of CNC machining.

That is, the protruding portion 14 is cut and removed so that a plurality of flow path holes 12 penetrating the hub portion 13 are formed in the corresponding portion.

Of course, at the time of CNC machining, the outer peripheral surface of the third machining work 1-3 may be further processed.

As a result, the differential cup 10 of the differential assembly produced by the differential cup assembly of the differential assembly of the present invention is characterized in that the material 1, made of an aluminum alloy, So that the molding of the flange portion 11 can be performed, thereby making it possible to prevent the molding failure with respect to the hub portion 13.

That is, when the hub portion 13 and the flange portion 11 are formed at the same time, the forging failure that can not accurately fill the corner portions of the hub portion 13 is solved by the manufacturing method of the present invention This makes it possible to produce diffusive cups of aluminum material and to obtain the same product reliability as the diffusive cups produced by casting.

Particularly, the method of manufacturing the differential cup of the differential assembly of the present invention is not limited to forming the flow hole 12 in the machining center after the forging of the differential cup 10 is completed, It is possible to reduce the manufacturing cost by employing the method of bending the portion where the flow hole 12 is to be formed to protrude into the workpiece and then cutting and removing the portion through CNC machining for the inner diameter machining The manufacturing time can be shortened.

1,1-1,1-2,1-3. Material 10.Differential Cup
11. Flange section 12. Euro hole
13. Hub part 14. Projection part
15. Injection site 16. Non-entry site
100. Mold for molding a hub part 110,120. Punch for primary molding
130. Die for primary molding 131. Rounding stage
132. First Diameter Division 133. First Vertical Section
134. Secondary Diameter Division 135. Second Vertical Section
200. Mold for flange part 210. Secondary forming punch
201. Inner side punch portion 202. Flange side punch portion
203. Base 211. Primary one
212. Secondary nozzle 220. Secondary die
221. Projection stage 222. Restriction stage
223. Embossed protrusions

Claims (6)

A method of manufacturing a differential cup of a differential assembly having a hub part formed by vertically passing a cup structure and a plurality of flow holes formed around the hub part and a flange part extending outward from an end of the hub part, ,
Preparing a preparation material for a differential cup;
A hub part forming step of forming a hub part by forging the material by using a primary molding punch and a primary molding die;
A flange portion forming step of forming a flange portion at an end of the hub portion using a punch for secondary molding and a die for secondary molding and bending molding the portion where the flow hole is to be formed to protrude into the inside;
A piercing step in which the hub portion and the flange portion vertically penetrate the inside of the molded workpiece;
And an inner diameter machining step of machining the inner diameter of the material and machining and removing a portion protruding from the inner portion of the material to form a plurality of flow holes. Method of manufacturing differential cups. The method according to claim 1,
Wherein the forming of the hub part is performed by rearwardly extruding the upper surface of the workpiece and forming the portion to be formed with the hub part by forwardly pushing the bottom surface of the workpiece,
Wherein the inner wall surface of the primary molding die has a rounded end formed so as to form a corner side portion of the hub portion, a primary radial divider inclined so as to extend outwardly from an end of the rounded end, And a secondary vertical edge formed vertically up and down from an end of the secondary shear edge, wherein the secondary vertical edge is formed so as to extend outwardly from the end of the primary vertical edge, And the upper and lower portions are formed vertically while maintaining the same thickness. The method of manufacturing the differential cup of the differential assembly using the cold forging. 3. The method of claim 2,
The inclination angle and height of the secondary diameter division are larger and higher than the inclination angle and height of the primary diameter division,
Wherein the height of the secondary vertical end is higher than the height of the primary vertical end. ≪ RTI ID = 0.0 > 15. < / RTI > The method according to claim 1,
Wherein the secondary forming punch includes an inner circumferential punch portion for protruding the inner peripheral surface of the hub portion and a portion where the flow hole is to be formed and a flange side punch portion for forming the flange portion while forming the upper end,
Wherein the inner circumferential side punch portion is formed in an inclined structure that gradually decreases in outer diameter toward the secondary molding die and that the flange side punch portion extends outward from the upper end of the inner circumferential side punch portion. A method of manufacturing a differential cup of a diffractive assembly using a liquid. 5. The method of claim 4,
Side punch portion is formed on a bottom surface of the flange-side punch portion so as to prevent buckling of the material while being formed at an edge portion contacting the inner circumferential side punch portion, and a first toothed portion extending outwardly from the primary shoulder, And a second shoulder for limiting the size of the outer diameter of the flange portion,
Wherein the secondary molding die is further formed with a restriction step for limiting the outer diameter of the flange portion along with the secondary shoulder,
Thereby preventing buckling on the peripheral surface of the hub when the flange is formed. The method according to claim 1,
Wherein a plurality of recessed portions and non-recessed portions are further formed on the surface of the flange portion in the flange portion forming step so that defective molding on the peripheral side surface of the flange portion can be prevented. A method of manufacturing a differential cup of a differential assembly.

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