CN114406161B - Net forming forging die for shaft forging - Google Patents

Abstract

The utility model relates to a net shaping forging die of axle class forging relates to the forging die field, including last mould and lower mould, the lower mould includes a plurality of half moulds and is used for fixing the mounting of relative position between the half moulds, and the die cavity that is used for shaping the forging is offered to the lower mould, and the die cavity is including the concave ring chamber that is used for shaping bulge loop, a plurality of half mould circumference sets up and encloses into concave ring chamber, and adjacent two the half mould is laminated each other, and the faying surface of two half moulds is the die joint of two half moulds, the die joint is on a parallel with the central axis of die cavity. The application has the effect of improving the utilization rate of raw materials.

Description

Net forming forging die for shaft forging

Technical Field

The application relates to the field of forging dies, in particular to a net forming forging die for shaft forgings.

Background

When the aviation turbofan engine works, the fan shaft needs to transmit turbine power to the fan, so that the fan is driven to generate thrust. The fan shaft is therefore subjected to a significant torque load during operation, and is typically a forging in order to increase the useful life of the fan shaft. The traditional engine fan shaft design is mostly of a gradual change type drum-shaped structure, and forging for producing the fan shaft by adopting die forging is the most economical and efficient production mode.

At present, the Chinese patent publication No. CN201510513390.7 discloses a forging die of a variable cross-section hollow shaft forging, which comprises an upper die and a lower die, wherein the lower die is provided with a die cavity, the inner diameter of the die cavity is gradually reduced from top to bottom, and after the upper die and the lower die are closed, a blank is extruded in the die cavity to form the forging. And then the upper die returns to the upper dead center, and the forging is ejected from the upper part by using the lower ejection of the forging press, so that the demoulding is completed.

With the development of technology, the fan shaft of the current aviation turbofan engine is of a closed-type bottle-shaped structure, as shown in fig. 1, a forging of the fan shaft of the aviation turbofan engine comprises:

a shaft section 100 having a cylindrical shape;

the circular table section 101 is in a circular table shape, and one end with a larger outer diameter is fixedly connected with the shaft section 100 in a coaxial manner;

the shaft bench section 102 is cylindrical and is coaxially and fixedly connected with one end of the circular bench section 101 with a smaller outer diameter, and a convex ring 103 is coaxially and fixedly connected with the outer wall of one end of the shaft bench section 102, which is close to the circular bench section 101;

the remainder section 104 is coaxially and fixedly connected to one end of the shaft section 100, which is far away from the circular table section 101, and is formed by piling up the remainder of the forging blank. The forging is coaxially provided with a central hole 105, and two ends of the central hole 105 penetrate through the forging.

The forging is generally formed into a cylindrical shaft with a central hole by die forging, and then the forging is formed into the shape by machining.

In view of the above-mentioned related art, the inventors consider that forming the outer shape of the forging piece retains much processing remainder, particularly, the positions of both axial ends of the convex ring, resulting in a defect of low utilization rate of raw materials.

Disclosure of Invention

In order to alleviate the problem that the raw material utilization rate of the shaft forging with the ring is low, the application provides a net forming forging die of the shaft forging.

The net forming forging die for the shaft forging provided by the application adopts the following technical scheme:

the utility model provides a net shaping forging die of axle class forging, includes mould and lower mould, the lower mould includes a plurality of half moulds and is used for fixing the mounting of relative position between the half moulds, and the die cavity that is used for shaping forging is offered to the lower mould, and the die cavity is including the concave ring chamber that is used for shaping bulge loop, a plurality of half mould circumference sets up and encloses into concave ring chamber, and two adjacent the half mould is laminated each other, and the faying surface of two half moulds is the die joint of two half moulds, the die joint is on a parallel with the central axis of die cavity.

By adopting the technical scheme, the heated blank is placed in the lower die, the upper die and the lower die are clamped, the blank deforms in the die cavity and exerts outward pressure on the die halves, and the relative position between the die halves is kept under the action of the fixing piece, so that the shape of the die cavity is maintained. When the blank is formed, the fixing piece is detached, and under the limitation of the fixing piece, the half dies can be separated from each other by taking the parting surface as a boundary, so that demolding is realized. Because the parting surface is parallel to the central axis of the die cavity, when the half dies are far away from each other, the half dies are not easily influenced by the convex rings along the radial direction of the convex rings when being separated from the forgings, and therefore the demolding is realized. The shape of the forged piece after forging and forming is closer to that of the part after forging and forming, and the processing excess materials are fewer, so that the utilization rate of raw materials is improved, and the production cost is reduced.

Optionally, the fixing member includes a plurality of bolts, and two adjacent half molds are fixedly connected through the bolts.

By adopting the technical scheme, the adjacent half molds are fixed by using the bolts. And when demolding is needed, the bolts are disassembled. The bolt has low cost and convenient operation.

Optionally, the cavity that the mounting was seted up, the lateral wall of die cavity one end was kept away from to the half is contradicted in the cavity lateral wall of mounting.

By adopting the technical scheme, during forging, the blank deforms in the die cavity and applies outward pressure to the half die; the half mould is abutted against the side wall of the cavity of the fixing piece, so that the force on the outer mould in the deformation process of the blank is balanced, and the position of the half mould is stabilized by the fixing piece, so that the shape of the die cavity is maintained. During demoulding, the fixing piece and the half mould move along the axial direction and in opposite directions, so that the half mould is separated from the fixing piece, the fixing piece is not in a relative position between the limiting half moulds, and the half mould and the forge piece can be separated, thereby realizing demoulding, and facilitating demoulding.

Optionally, the fixing piece comprises two semi-rings, the two semi-rings are abutted and enclosed into a ring, and the two semi-rings are detachably and fixedly connected.

Through adopting above-mentioned technical scheme, during the drawing of patterns, dismantle between two semi-rings earlier to the separation of solid fixed ring and half mould of being convenient for has further promoted the drawing of patterns efficiency of forging.

Optionally, the mounting is including the external mold of seting up the cavity, be provided with the centre form in the external mold, the die cavity is seted up in the centre form or is seted up in centre form and external mold, the centre form includes two at least the half mould, die cavity one side and the cavity inner wall butt of external mold are kept away from to the half mould, the external mold is used for fixed connection in the lower work platform of forging press and the lower ejecting of lower work platform aim at the centre form.

Through adopting above-mentioned technical scheme, external mold fixed connection is in work platform down, and after the forging and pressing was accomplished, down ejecting starts and promotes the centre form, makes the centre form break away from in the cavity of external mold, and the centre form does not have the constraint of external mold to be convenient for half and forging separation. The forging die can be matched with the existing equipment for use, so that the demolding is more convenient.

Optionally, the die cavity still includes the first cylinder chamber that is used for shaping axle section, is used for the round platform chamber of shaping round platform section and is used for the second cylinder chamber of shaping axle platform section, concave ring chamber is located between second cylinder chamber and the round platform chamber and the three is coaxial setting, the cavity of external mold is cylindricly, and its axial length is greater than the axial length of centre form, the centre form is located the cavity and is in the one end of external mold, the one end that the second cylinder chamber was seted up to the centre form is located the tip position of external mold, round platform chamber and second cylinder chamber are seted up in the centre form, the space that the cavity of external mold did not hold the centre form is first cylinder chamber.

Through adopting above-mentioned technical scheme, the axle section of forging is at cavity internal shaping, can reduce the length of centre form, reduces the material of centre form, reduces the cost of mould to reduce the weight of centre form, thereby the ejecting in the external mold of centre form of being convenient for, also be convenient for install the centre form in the external mold.

Optionally, the inner mold further comprises a bottom plate, which abuts against an inwardly facing side wall of the mold half and/or an end face facing away from the upper mold.

Through adopting above-mentioned technical scheme, utilize bottom plate closed die cavity lower extreme, the extrusion of cooperation mould makes the both ends of forging all receive pressure, and the forging tip is more level and smooth, thereby the maintenance skin that thereby reducible die forging process breaks away from on the blank gets into ejection down from the opening of centre form lower extreme simultaneously.

Optionally, the die half includes first circular arc board and second circular arc board that lays along die cavity axial, first circular arc board axial one end and second circular arc board axial one end butt, the round platform cambered surface has been seted up to first circular arc board, and the round platform cambered surface of all first circular arc boards is constituteed the lateral wall in round platform chamber, all the lateral wall in second circular arc board is constituteed the lateral wall in second cylinder chamber, concave ring chamber includes a plurality of arc recesses of seting up in the die half, the arc recess is seted up in first circular arc board and/or second circular arc board.

Through adopting above-mentioned technical scheme, during the drawing of patterns, break away from the forging with first circular arc board earlier, then break away from the forging with second circular arc board again to reduce the pressure between the bulge loop of the end wall of concave ring chamber and forging, and then reduce the frictional force between the two, the half mould drawing of patterns of being convenient for.

Optionally, the lower die further comprises a driving mechanism for driving the inner die to coaxially rotate relative to the outer die, the direction of torque applied to the two ends of the forging piece by the rotation of the inner die is the same as the direction of torque applied to the two ends of the forging piece in the working state, and the driving mechanism comprises a power assembly for providing power for the rotation of the inner die and a transmission assembly for transmitting the power of the power assembly to the inner die;

the power assembly comprises an electric motor fixed relative to the outer die, a driving gear ring rotating relative to the outer die and a transmission gear meshed with the driving gear ring, wherein a main shaft of the electric motor is coaxially and fixedly connected with the driving gear, the driving gear is meshed with the driving gear ring, and the transmission gear is rotationally connected with a lower working platform of the forging press and used for transmitting power to the transmission assembly;

the quantity of drive assembly is the same with the quantity of half mould, and every drive assembly includes the transmission shaft that is on a parallel with the centre axis of the centre form, the transmission shaft slides along being close to or keeping away from half mould direction, coaxial fixedly connected with of transmission shaft carries out the gear, a plurality of tooth's socket formation incomplete ring gear have been seted up to half mould outer wall, carry out gear and incomplete ring gear meshing, transmission shaft one end is connected with transfer gear through setting up the shaft coupling, the shaft coupling is telescopic double-universal-joint shaft coupling, external mold fixedly connected with is used for driving the pneumatic cylinder that the transmission shaft slided.

By adopting the technical scheme, in the forging forming process or after the forging is formed, the power assembly is started to transmit power to the transmission assembly, and the transmission assembly drives the inner die to rotate in the outer die. The internal mold rotates relative to the external mold, the internal mold drives one end of the forging to rotate, and the forging is twisted, so that the forging streamline after the forging is molded is spiral, and the direction of torque applied to the two ends of the forging by the lower mold is the same as the direction of torque applied to the two ends of the forging in the working state due to the rotation of the internal mold, so that the force born by the forging in working is along the forging streamline. Because the forging has higher tensile strength along the direction of forging streamline, the fan shaft forging with the structure has stronger torsional strength in the working environment, reduces the possibility of damage to the forging, and prolongs the service life of the forging.

Optionally, each transmission shaft is coaxially and fixedly connected with two execution gears, two execution gears located on the same transmission shaft are respectively a first execution gear and a second execution gear, the first circular arc plate and the second circular arc plate are provided with incomplete gear rings, the incomplete gear rings arranged on the first circular arc plate are first incomplete gear rings, the incomplete gear rings arranged on the second circular arc plate are second incomplete gear rings, the first execution gear is meshed with the first incomplete gear rings, the second execution gear is meshed with the second incomplete gear rings, and the indexing circle diameter of the first execution gear is smaller than that of the second execution gear.

Through adopting above-mentioned technical scheme, power component drives the transmission shaft and rotates, and two execution gears of coaxial fixed connection in the transmission shaft rotate to drive first circular arc board and second circular arc board simultaneously and rotate. Because the reference circle diameter of the first executing gear is smaller than that of the second executing gear, the rotating speed of the first circular arc plate is slower than that of the second circular arc plate, the round table section of the forging is used as a transition section for torsion of the forging, and the fracture of the forging caused by overlarge torsion angle of the forging is reduced.

In summary, the present application includes at least one of the following beneficial technical effects:

the mold halves enclose a mold cavity for forming shaft forgings, the joint surfaces of the two mold halves are parallel to the central axis of the mold cavity, and then the relative positions of the mold halves are fixed by using a fixing piece. After the blank is deformed and molded in the die cavity, the fixing piece is disassembled, and then the half dies are separated from each other, so that the demolding is realized. Because the joint surfaces of the two half molds are parallel to the central axis of the mold cavity, when the half molds are mutually far away from each other, the half molds are not easily affected by the convex rings when being separated from the forging pieces, the shapes of the forging pieces after forging and molding and the part after forging processing are more approximate, and processing residual materials are fewer, so that the utilization rate of raw materials is improved, and the production cost is reduced.

The half mould comprises a first arc plate and a second arc plate, the first arc plate is provided with a circular table cambered surface, the circular table cambered surface is used for combining the side wall of the circular table cavity, the side wall of the second arc plate is used for forming the side wall of the cylindrical cavity, the concave ring cavity comprises a plurality of arc grooves formed in the half mould, and the arc grooves are formed in the first arc plate and/or the second arc plate. During demoulding, the first arc plate and the second arc plate can be separated from the forging piece in sequence, so that friction force between the half mould and the forging piece is reduced, and demoulding is facilitated.

The lower die further comprises a driving mechanism for driving the inner die to coaxially rotate relative to the outer die, and the driving mechanism is started in the forging forming process or after the forging is formed, so that the inner die rotates relative to the outer die. The internal mold drives one end of the forging to rotate, the forging streamline after the forging is formed is spiral, and the force born by the forging during working is along the forging streamline, so that the torsional strength of the fan shaft forging in the working environment is improved.

Drawings

Fig. 1 is a cross-sectional view of a related art for showing a structure of a fan shaft forging.

Fig. 2 is a cross-sectional view for showing the structure of a forging die mounted to a forging press in example 1 of the present application.

Fig. 3 is a sectional view for showing the lower die structure in embodiment 1 of the present application.

Fig. 4 is an exploded view for showing the fixing member in embodiment 2 of the present application.

Fig. 5 is a sectional view for showing the lower die in embodiment 2 of the present application.

Fig. 6 is a sectional view for showing the lower die in embodiment 3 of the present application.

Fig. 7 is a sectional view for showing a floor structure in embodiment 3 of the present application.

Fig. 8 is a sectional view for showing another structure of the base plate in embodiment 3 of the present application.

Fig. 9 is a sectional view for showing another structure of the base plate in embodiment 3 of the present application.

Fig. 10 is a sectional view for showing the lower die structure in embodiment 4 of the present application.

Fig. 11 is an exploded view for showing the internal mold structure in example 4 of the present application.

Fig. 12 is a sectional view for showing the driving mechanism in embodiment 5 of the present application.

Fig. 13 is a structural view for showing a driving mechanism in embodiment 5 of the present application.

Fig. 14 is a cross-sectional view for showing the internal expansion limiter mechanism in embodiment 5 of the present application.

Fig. 15 is a cross-sectional view for showing the extrusion mandrel in example 6 of the present application.

Fig. 16 is a sectional view for showing the guide groove in embodiment 6 of the present application.

Reference numerals illustrate: 100. a shaft section; 101. a circular table section; 102. a shaft block section; 103. a convex ring; 104. a remainder section; 105. a central bore; 200. an upper die; 201. extruding a block; 203. extruding the core rod; 204. a guide block; 205. a connecting shaft; 206. a fixed section; 207. a free section; 208. a rotating section; 209. a wire slot; 300. a lower die; 301. a mold cavity; 302. an inner mold; 303. a fixing member; 304. a half mold; 305. a bottom plate; 306. a first cylindrical cavity; 307. a circular truncated cone cavity; 308. a concave annular cavity; 309. a second cylindrical cavity; 310. a residue cavity; 311. a half ring; 312. a cavity; 313. a first connection block; 314. a second connection block; 315. a first connection hole; 316. a second connection hole; 317. a fixing pin; 318. an outer mold; 319. an annular accommodating groove; 320. a first circular arc plate; 321. a second arc plate; 322. a circular truncated cone cambered surface; 323. an arc-shaped groove; 324. a guide groove; 325. a guide rail; 400. a driving mechanism; 401. a power assembly; 402. a transmission assembly; 403. an electric motor; 404. a drive gear; 405. driving the gear ring; 406. a transmission gear; 407. a transmission shaft; 408. a first actuator gear; 409. a second actuator gear; 410. a first incomplete ring gear; 411. a second incomplete ring gear; 412. a chute; 413. a coupling; 414. a slide block; 415. a hydraulic cylinder; 416. a receiving groove; 500. a working platform; 501. a lower working platform; 502. a receiving chamber; 503. an upper die moving device; 504. a sliding block; 505. a cylinder; 600. an internal expansion limiting mechanism; 601. a connecting seat; 602. an internal expansion structure; 603. a disc portion; 604. a cylindrical portion; 605. a cylindrical cavity; 606. a through groove; 607. wedge blocks; 608. round table blocks; 609. a spring; 610. and (5) connecting the columns.

Detailed Description

The present application is described in further detail below in conjunction with figures 1-13.

Referring to fig. 1, related art 1: a forging for an aircraft turbofan engine fan shaft comprising:

a shaft section 100 having a cylindrical shape;

the circular table section 101 is in a circular table shape, and one end with a larger outer diameter is fixedly connected with the shaft section 100 in a coaxial manner;

the shaft bench section 102 is cylindrical and is coaxially and fixedly connected with one end of the circular bench section 101 with a smaller outer diameter, and a convex ring 103 is coaxially and fixedly connected with the outer wall of one end of the shaft bench section 102, which is close to the circular bench section 101;

the remainder section 104 is coaxially and fixedly connected to one end of the shaft section 100, which is far away from the circular table section 101, and is formed by piling up the remainder of the forging blank. The forging is coaxially provided with a central hole 105, and two ends of the central hole 105 penetrate through the forging.

The embodiment of the application discloses a net forming forging die of a shaft forging piece, which is used for producing the forging piece in the related technology.

Example 1:

referring to fig. 2, the forging die includes an upper die 200 and a lower die 300. The upper die 200 is mounted to an upper work platform 500 of the forging press, and the lower die 300 is provided with a die cavity 301 for forming the forging, and is mounted to a lower work platform 501 of the forging press. In operation, the forging press lifts the upper die 200 and then places the heated blank in the lower die 300, the forging press drives the upper die 200 to move towards the lower die 300, the upper die 200 presses the blank into the die cavity 301, and when the upper die 200 and the lower die 300 are clamped, the blank is extruded into a forging in the die cavity 301 of the lower die 300.

Referring to fig. 3, the lower mold 300 includes a plurality of mold halves 304, the plurality of mold halves 304 being circumferentially disposed and surrounding the mold cavity 301 as described above. Adjacent mold halves 304 are attached to each other, and the interface between the mold halves 304 is the parting plane of the two mold halves 304. The parting plane is parallel to the central axis of the mold cavity 301 and is arranged vertically. The number of the mold halves 304 may be three or four, and the number of the mold halves 304 may be two or more.

Referring to fig. 3, the mold cavity 301 includes a first cylindrical cavity 306, a truncated cone cavity 307, a concave ring cavity 308, and a second cylindrical cavity 309, which are coaxially disposed.

Referring to fig. 3, a first cylindrical cavity 306 is used to shape the shaft segment 100, with its inner wall being cylindrical. The circular table cavity 307 is used for forming the circular table section 101, and the inner wall of the circular table cavity is a circular table surface. The larger inner diameter end of the circular truncated cone cavity 307 communicates with the first cylindrical cavity 306, and the larger inner diameter end of the circular truncated cone cavity 307 has an inner diameter less than or equal to the inner diameter of the first cylindrical cavity 306. The smaller inner diameter end of the inner wall of the circular truncated cone cavity 307 communicates with the concave annular cavity 308. The female ring cavity 308 is used to form the male ring 103. The lower end of the concave annular cavity 308 communicates with a second cylindrical cavity 309, the second cylindrical cavity 309 being used to shape the shaft table section 102.

Referring to fig. 3, to accommodate the remainder of the forged blank, the die cavity 301 further includes a remainder cavity 310 in communication with the upper end of the first cylindrical cavity 306, the remainder of the blank after compression deformation remaining within the remainder cavity 310 and forming the remainder section 104. The inner diameter of the residual material cavity 310 is larger than that of the first cylindrical cavity 306, and a chamfer is arranged at the joint of the side wall of the residual material cavity 310 and the side wall of the first cylindrical cavity 306.

Referring to fig. 3, the lower mold 300 further includes a fixture 303 for fixing the relative position between the mold halves 304. The fixing member 303 is detachably connected to the mold half 304. In operation, the forging dies maintain the relative position between the die halves 304 under the action of the fasteners 303 to maintain the shape of the die cavity 301. After the forging is formed, the fixture 303 is disassembled and then the mold halves 304 are moved radially away from the forging to effect demolding. Because the direction in which the half mold 304 is separated from the forging is along the radial direction of the convex ring 103, the half mold 304 is not easily affected by the convex ring 103 when separated from the forging.

Referring to fig. 3, in this embodiment the fixing member 303 comprises a plurality of bolts, between which two adjacent half-molds 304 are fixedly connected. When demolding is needed, the bolts can be disassembled.

Referring to fig. 2, an upper die 200 includes an extrusion block 201 and an extrusion core rod 203. Both of which are mounted to the upper die moving device 503 of the upper work platform 500 of the forging press. The upper die moving device 503 is used to move the horizontal positions of the extrusion block 201 and the extrusion core rod 203. The upper die moving device 503 may move the extrusion block 201 directly above the lower die 300 or move the extrusion core rod 203 directly above the lower die 300. The extrusion block 201 has a cylindrical shape, and the outer diameter of the lower end thereof is equal to the inner diameter of the residual material chamber 310. The extrusion core rod 203 is cylindrical, and is coaxially and slidably connected with a guide block 204, and the outer diameter of the guide block 204 is equal to the inner diameter of the residual material cavity 310.

Referring to fig. 2, the upper die moving device 503 includes a slide block 504 horizontally slidably coupled to the upper work platform 500 and a cylinder 505 for driving the slide block 504 to move. The sliding block 504 is in a rectangular strip shape, and the extrusion block 201 and the extrusion core rod 203 are fixedly connected to the sliding block 504. Cylinder 505 has its cylinder body fixedly connected to upper working platform 500, and cylinder 505 pushes sliding block 504 to slide along its length direction.

The implementation principle of the embodiment 1 is as follows: the heated blank is placed in the excess material cavity 310, the upper die moving device 503 is controlled to move the extrusion block 201 to the position right above the lower die 300, and then the forging press is started to clamp the extrusion block 201 and the lower die 300, so that the blank is extruded into the first cylindrical cavity 306, the round table cavity 307, the concave ring cavity 308 and the second cylindrical cavity 309, and the blank is extruded and molded in the die cavity 301. The forging press moves the extrusion block 201 upward to be separated from the lower die 300.

The upper die moving device 503 is controlled to move the extrusion mandrel 203 to a position directly above the lower die 300. The forging press is started to clamp the extrusion core rod 203 and the lower die 300, and the center hole 105 of the forging is formed.

The fixture 303 is then removed and the mold halves 304 are separated from each other along the parting plane, thereby effecting demolding. Because the parting plane is parallel to the central axis of the die cavity 301, when the half dies 304 are mutually far away from each other, the half dies 304 are not easily affected by the convex rings 103 when being separated from the forgings, so that the machining allowance can be reduced, the utilization rate of raw materials is improved, and the production cost is reduced when shaft parts with the convex rings 103 are forged.

Example 2:

referring to fig. 4, embodiment 2 is different from embodiment 1 in a fixing member 303. The fixing member 303 includes two half rings 311, wherein one end of one half ring 311 is hinged to one end of the other half ring 311, and one ends of the two half rings 311 away from the hinge point are abutted to each other and are detachably and fixedly connected through a quick-release structure. The two semi-rings 311 enclose a ring, and the space in the middle of the ring is a cavity 312.

Referring to fig. 4, the quick release structure includes a first connection block 313 fixedly connected to one half ring 311 and a second connection block 314 fixedly connected to the other half ring 311, wherein the first connection block 313 is provided with a first connection hole 315. The second connection block 314 is provided with a second connection hole 316. The central axes of the first and second connection holes 315 and 316 are parallel to the central axis of the cavity 312. When the two half rings 311 are abutted to each other at the end far away from the hinge point, the first connecting hole 315 and the second connecting hole 316 are coaxially disposed.

Referring to fig. 4, the quick release structure further includes a fixing pin 317, and the fixing pin 317 is simultaneously inserted through the first and second connection holes 315 and 316, thereby defining positions of the first and second connection blocks 313 and 314. Pulling out the fixing pins 317 allows the removal of one end of the two half rings 311. The end of the two semi-rings 311 away from the hinge point can be fixed by bolts, and only the detachable and fixed connection of the end of the two semi-rings 311 away from the hinge point is needed.

Referring to fig. 5, all the mold halves 304 are inserted into the fixing member 303, the outer walls of the mold halves 304 are circular arc, and when all the mold halves 304 are circumferentially arranged and enclose the mold cavity 301, the side wall of one end of the mold half 304 facing away from the mold cavity 301 is the outer wall of the mold half 304, and the outer walls of all the mold halves 304 form a complete cylindrical surface and are abutted against the inner wall of the cavity 312 of the fixing member 303. The securing members 303 serve to balance the outward forces applied to the mold halves 304 during deformation of the blank within the mold cavity 301, thereby stabilizing the position of the mold halves 304 and maintaining the shape of the mold cavity 301.

Embodiment 2 differs from embodiment 1 in the following implementation principle: when the blank is formed, the bolts or fixing pins 317 are removed and the half ring 311 is rotated in the opposite direction, thereby removing the fixing member 303. The fixing member 303 does not limit the relative position between the half molds 304 any more, so that the half molds 304 and the forging pieces can be separated, thereby realizing demolding and facilitating demolding.

Example 3:

referring to fig. 6, embodiment 3 is different from embodiment 2 in that a fixing member 303, and the fixing member 303 includes an outer mold 318 having a cavity 312 formed therein. The cavity 312 is cylindrical in shape and extends axially through both ends of the outer mold 318. An inner mold 302 is inserted into the cavity 312 of the outer mold 318, and the inner mold 302 is provided with a mold cavity 301 for molding a fan shaft forging in the related art.

Referring to fig. 6, outer die 318 is fixedly connected to a lower work platform 501 of the forging press by bolts, and the lower ejection of lower work platform 501 aligns with inner die 302 within outer die 318.

Referring to fig. 6, the inner mold 302 includes at least two mold halves 304 as described in embodiment 2, with all mold halves 304 disposed circumferentially within the cavity 312 of the outer mold 318 and surrounding the mold cavity 301. The side walls of the mold halves 304 facing away from the mold cavity 301 conform to the interior walls of the cavity 312 of the outer mold 318.

Referring to fig. 7, the inner mold 302 further includes a bottom plate 305 for closing the lower end opening of the mold cavity 301. The bottom plate 305 is circular and the bottom plate 305 has a diameter equal to the inner diameter of the second cylindrical cavity 309, the bottom plate 305 sidewall conforming to the inner wall of the mold half 304.

Referring to fig. 8, in another embodiment, the side walls of the bottom plate 305 are attached to the side walls of the cavity 312 of the outer mold 318, and the lower end surface of the mold half 304 abuts against the upper end surface of the bottom plate 305.

Referring to fig. 9, in another embodiment, the upper end surface of the bottom plate 305 is provided with an annular receiving groove 319, and the lower end of the mold half 304 is disposed in the annular receiving groove 319. The side walls of the mold half 304 conform to the side walls of the cavity 312 of the outer mold 318 and the inner walls of the mold half 304 conform to the side walls of the annular receiving groove 319.

Embodiment 3 differs from embodiment 2 in the following implementation principle: the outer mold 318 is fixedly attached to the lower work platform 501 and after forging is completed, the lower ejection is activated and pushes the inner mold 302 upward relative to the outer mold 318, disengaging the inner mold 302 from the cavity 312 of the outer mold 318. The mold halves 304, which are not secured in relative position by the outer mold 318, facilitate separation from the forging. The forging die can be matched with the existing equipment for use, so that the demolding is more convenient.

Example 4:

referring to fig. 10, embodiment 4 differs from embodiment 3 in that the axial length of the inner die 302 is smaller than that of the outer die 318, and the inner die 302 is located at a lower position within the outer die 318.

Referring to fig. 10, a cavity 301 is opened in a lower mold 300. Wherein a circular table cavity 307 for forming the circular table section 101, a concave ring cavity 308 for forming the convex ring 103 and a second cylindrical cavity 309 for forming the shaft table section 102 are opened in the inner mold 302. The upper end of the outer mold 318 is provided with the residual material cavity 310, and the residual material cavity 310 and the cavity 312 are coaxially arranged. The space between the cavity 312 from the remainder cavity 310 to the truncated cone cavity 307 is the first cylindrical cavity 306.

Example 4 also differs from example 3 in the mold half 304.

Referring to fig. 10 and 11, the mold half 304 includes a first circular arc plate 320 and a second circular arc plate 321 axially distributed along the mold cavity 301. The first arc plate 320 is located above the second arc plate 321, and the lower end surface of the first arc plate 320 is attached to the upper end surface of the second arc plate 321.

Referring to fig. 11, the inner wall of the first arc plate 320 is provided with a circular arc surface 322, and the circular arc surfaces 322 of all the first arc plates 320 form a circular table surface, and the circular arc surface is a side wall of the circular cavity 307. The inner wall of the second circular arc plate 321 is the side wall of the second cylindrical cavity 309. The concave annular cavity 308 includes a plurality of arcuate grooves 323 formed in the mold half 304, the arcuate grooves 323 being located at the lower end of the inner wall of the first circular arc plate 320. The arc-shaped groove 323 can also be positioned at the upper end of the inner wall of the second arc-shaped plate 321, or one half of the arc-shaped groove 323 is positioned at the lower end of the first arc-shaped plate 320, and the other half is positioned at the upper end of the second arc-shaped plate 321.

Referring to FIG. 11, because of the split design of the first circular arc plate 320 and the second circular arc plate 321, the male ring 103 of the forging will not become stuck in the female ring cavity 308 during demolding, and the mold half 304 and the forging can be separated more easily.

Referring to fig. 11, also because of the split design of the first circular arc plate 320 and the second circular arc plate 321, the blank forms the convex ring 103 by applying an upward pressing force to the first circular arc plate 320, which may cause the first circular arc plate 320 to slide upward, which is called "floating". The "floating" of the first circular arc plate 320 can cause the shape of the mold cavity 301 to change, thereby causing the forging to fail.

Referring to fig. 11, the frustoconical cambered surface 322 design, however, alleviates just the above-mentioned problems. As the blank is pressed into the die cavity 301, it presses against the frustoconical curved surface 322 and then into the concave annular cavity 308. When the blank presses against the frustoconical curved surface 322, two force components are created. One component is a horizontal component along the radial direction of the mold cavity 301 and directed outside the mold cavity 301, and the other component is a vertical component vertically downward. The vertical component force applies downward force to the first arc plate 320, so that the first arc plate 320 and the second arc plate 321 are closely attached, upward extrusion force applied to the first arc plate 320 when the blank is used for forming the convex ring 103 can be balanced, and the problem that the blank floats upwards in the extrusion forming process of the first arc plate 320 is solved.

Example 5:

referring to fig. 12, embodiment 5 differs from embodiment 4 in that: the lower die 300 also includes a drive mechanism 400 that drives the inner die 302 in coaxial rotation relative to the outer die 318.

Referring to FIG. 12, during or after forging forming, the drive mechanism 400 is activated to rotate the inner die 302 within the outer die 318. The inner mold 302 rotates relative to the outer mold 318, the inner mold 302 drives the lower end of the forging to rotate, and the forging is twisted, so that the forging streamline after the forging is formed is spiral.

The rotation direction of the inner mold 302 relative to the outer mold 318 is set according to the stress condition of the forging in the working state. The direction in which both ends of the forging receive torque in the lower die 300 is the same as the direction in which both ends receive torque in the operating state.

The fan shaft processed by the forging in the embodiment has the following working state: the turbine drives the fan shaft to rotate clockwise, the driving force of the turbine acts on the shaft section 100 of the fan shaft, and the pillow block section 102 of the fan shaft is used for installing the fan. At this time, the torque applied to the shaft section 100 of the fan shaft is clockwise, and when the fan shaft drives the fan to rotate, the fan is subjected to air resistance. Air resistance is transferred by the fan to the pillow block 102 of the fan shaft in a counterclockwise direction. When the fan shaft forging is forged, the driving mechanism 400 drives the inner mold 302 to rotate anticlockwise.

Referring to fig. 12, the direction in which both ends of the forging receive torque in the lower die 300 is the same as the direction in which both ends receive torque in the working state, so that the direction of the forging streamline of the forging is the same as the direction in which the forging receives force when working. Because the forging has higher tensile strength along the direction of forging streamline, the fan shaft forging with the structure has stronger torsional strength in the working environment, reduces the possibility of damage to the forging, and prolongs the service life of the forging.

Referring to fig. 12, the driving mechanism 400 includes a power assembly 401 for powering the rotation of the inner mold 302 and a transmission assembly 402 for transmitting the power of the power assembly 401 to the inner mold 302. Wherein the number of drive assemblies 402 is three and disposed circumferentially along the outer wall of the inner mold 302.

Referring to fig. 12 and 13, a receiving chamber 502 for receiving the power assembly 401 is formed at an upper end of the lower working platform 501. The power assembly 401 includes an electric motor 403 fixedly connected to a lower work platform 501. The main shaft of the electric motor 403 is vertically arranged upwards and is coaxially and fixedly connected with a driving gear 404.

Referring to fig. 12 and 13, the power assembly 401 further includes a driving ring gear 405 meshed with the driving gear 404, and the driving ring gear 405 is rotatably connected to the lower working platform 501 through a planar bearing and is disposed coaxially with the inner mold 302. The lower working platform 501 is rotatably connected with three transmission gears 406 meshed with the driving gear ring 405, the transmission gears 406 are circumferentially arranged along the outer wall of the inner mold 302, and one transmission gear 406 drives one transmission assembly 402 to rotate.

Referring to fig. 12 and 13, the outer wall of the outer mold 318 is provided with a receiving slot 416 for receiving the drive assembly 402. The drive assembly 402 includes a drive shaft 407 in a vertical arrangement with a lower end passing through the outer mold 318 and extending into the receiving cavity 502. The lower end of the transmission shaft 407 is connected with the transmission gear 406 through a coupling 413. The transmission shaft 407 is coaxially and fixedly connected with two executing gears, namely a first executing gear 408 and a second executing gear 409. A plurality of tooth grooves are circumferentially formed on the outer walls of the first arc plate 320 and the second arc plate 321 so as to form an incomplete gear ring. The incomplete ring gear of the first circular arc plate 320 is a first incomplete ring gear 410, and the first incomplete ring gear 410 is meshed with the first execution gear 408. The incomplete ring gear of the second circular arc plate 321 is a second incomplete ring gear 411, and the second incomplete ring gear 411 is meshed with the second execution gear 409. The pitch diameter of the first actuating gear 408 is smaller than the pitch diameter of the second actuating gear 409. When the power assembly 401 drives the transmission shaft 407 to rotate, the rotational speeds of the first and second actuating gears 408 and 409 are the same, but the linear speed of the outer diameter of the first actuating gear 408 is less than the linear speed of the outer diameter of the second actuating gear 409, resulting in the rotational speed of the first circular arc plate 320 being less than the rotational speed of the second circular arc plate 321. In the process of twisting the forging, the round table section 101 of the forging serves as a transition section for twisting the forging, so that the occurrence of fracture conditions of the forging caused by overlarge torsional angle of the forging is reduced.

Referring to fig. 12 and 13, to reduce interference of the actuating gear when the inner mold 302 is disengaged from the outer mold 318, the drive shaft 407 is slidably disposed with the outer mold 318. The side walls of the upper and lower sides in the accommodating groove 416 are provided with sliding grooves 412 for sliding the transmission shaft 407. The longitudinal extension of the chute 412 passes through the center line of the cavity 301. A lower positioned chute 412 extends through the lower end surface of the outer mold 318 and communicates with the receiving cavity 502. The sliding groove 412 is connected with a sliding block 414 in a sliding way along the length of the sliding groove, and the upper end of the transmission shaft 407 is penetrated through the sliding block 414 and is rotationally connected with the sliding block 414 by installing a rolling bearing. The lower end of the drive shaft 407 passes through a further slide 414 and is rotatably connected to this slide 414 by means of a mounted rolling bearing. The coupling 413 for connecting the drive shaft 407 to the transfer gear 406 is a telescopic double-universal coupling.

Referring to fig. 12 and 13, the drive assembly 402 further includes a hydraulic cylinder 415 for driving the drive shaft 407 to slip. The cylinder body of the hydraulic cylinder 415 is fixedly connected to the outer mold 318, and the transmission shaft 407 is arranged through the piston rod of the hydraulic cylinder 415 in a penetrating manner and is rotationally connected with the piston rod.

Referring to fig. 14, the upper working platform 500 is further provided with an internal expansion limiting mechanism 600 for limiting the rotation of the upper end portion of the forging, so as to alleviate the problem that when the internal mold 302 drives the lower end of the forging to rotate, the whole forging rotates along with it, and cannot apply torque to the forging.

Referring to fig. 14, the internal expansion limiting mechanism 600 includes a connecting seat 601 and an internal expansion structure 602 disposed in the connecting seat 601.

The connection seat 601 includes a disc portion 603 and a cylindrical portion 604 coaxially and fixedly connected to the disc portion 603. The cylindrical portion 604 defines a cylindrical cavity 605 for receiving the inner expansion structure 602. The cylindrical portion 604 is circumferentially provided with three rectangular through grooves 606, and the through grooves 606 are communicated with the cylindrical cavity 605.

Referring to fig. 14, the diameter of the disk portion 603 is slightly smaller than the diameter of the cull chamber 310, and the diameter of the cylindrical portion 604 is slightly smaller than the diameter of the central hole 105.

Referring to fig. 14, the inner expansion structure 602 includes three wedge blocks 607, and the wedge blocks 607 slide one-to-one in the through grooves 606. The outer wall of the wedge block 607 is an arc surface which is vertically arranged, and the inner wall of the wedge block is an arc surface which is obliquely arranged. The upper end of the inner wall of the wedge 607 is inclined outwardly so that the wedge 607 becomes thicker in a vertically downward direction.

Referring to fig. 14, the internal expansion structure 602 further includes a circular truncated cone 608, where the circular truncated cone 608 is located in the cylindrical cavity 605 and has a small end face (the small end face is the smaller diameter end face of the circular truncated cone 608) facing downward. The diameter of the large end face of the circular truncated cone 608 (the large end face is the end face with the larger diameter of the circular truncated cone 608) is equal to the diameter of the cylindrical cavity 605. The circular truncated cone side wall of the circular truncated cone block 608 is parallel to and attached to the inner wall of the wedge block 607.

Referring to fig. 14, when the circular truncated cone 608 moves downward, the circular truncated cone 608 pushes the wedge 607 to move outward of the connection socket 601. In order to facilitate pushing the circular boss 608, the inner expanding structure 602 further includes a connecting post 610 coaxially and fixedly connected to a large end surface of the circular boss 608. The diameter of the connecting post 610 is smaller than the diameter of the large end face of the circular block 608. The connection post 610 passes through the cylindrical portion 604 and the disk portion 603 in sequence, and extends out of the connection holder 601. The connecting post 610 is used for fixedly connecting with the sliding block 504 of the upper working platform 500.

Referring to fig. 14, a spring 609 is further disposed in the cylindrical cavity 605, one end of the spring 609 abuts against the bottom of the cylindrical cavity 605, and the other end abuts against the small end face of the circular truncated cone 608.

Example 5 differs from example 4 in the principle of implementation:

during or after forging forming, the sliding block 504 is moved so that the internal expansion limit mechanism 600 is located directly above the lower die 300. Then the upper die 200 drives the internal expansion limiting mechanism 600 to press down. The cylindrical portion 604 is inserted into the central hole 105 of the forging, and when the disc portion 603 abuts against the upper end surface of the forging, the connection seat 601 does not move downward. But the connecting post 610 continues to move the circular boss 608 downward.

When the round table block 608 moves downwards, the wedge block 607 is pushed to move outwards. The wedge 607 moves outward and abuts the inner wall of the central bore 105 of the forging, thereby clamping the forging in place. The circular table 608 moves downward, and compresses the spring 609, and the connection seat 601 is pressed downward by the spring 609, so that the disc 603 is used to forge the forging. The upper end of the forging is fixed by the internal expansion limiter 600.

Then, the electric motor 403 is started, and the electric motor 403 drives the drive ring gear 405 to rotate through the drive gear 404. The transfer gear 406 is also rotated in engagement with the drive ring gear 405. The transfer gear 406 transfers torque to the drive shaft 407 through the telescoping double cardan coupling. The actuating gear, which is coaxially and fixedly connected to the drive shaft 407, also rotates therewith. The execution of the gear rotation rotates the inner mold 302 within the outer mold 318. The inner die 302 drives one end of the forging to rotate, and the forging is twisted, so that a forging streamline after the forging is formed is spiral, the torsional strength of the shaft forging of the fan in the working environment is improved, the possibility of damage to the forging is reduced, and the service life of the forging is prolonged.

Example 6:

referring to fig. 15, embodiment 6 differs from embodiment 5 in that: the extrusion mandrel 203 includes:

the connecting shaft 205 is vertically and rotatably connected to the sliding block 504, and a stepping motor is fixedly connected to the sliding block 504 and is used for driving the connecting shaft 205 to rotate;

the fixed section 206 is sleeved on the connecting shaft 205 and is fixedly connected with the sliding block 504;

the free section 207 is sleeved on the connecting shaft 205 and is rotationally connected with the connecting shaft 205 and is positioned below the fixed section 206;

the rotating section 208 is fixedly connected to the lower end of the connecting shaft 205 and abuts against the lower end of the free section 207, and the lower end of the rotating section 208 is bullet-shaped. A plurality of wire slots 209 are circumferentially formed in the lower end of the rotary segment 208. The wire slot 209 extends along the axial direction of the rotating section 208.

Referring to fig. 16, the outer wall of the mold half 304 is provided with a plurality of spiral guide grooves 324, and the spiral direction of the guide grooves 324 is counterclockwise and spirally upward. The inner wall of the outer mold 318 is provided with a plurality of spiral guide rails 325, and the guide rails 325 are matched with the guide grooves 324. During the demolding, the inner mold 302 rotates anticlockwise under the action of the guide rails 325 and the guide grooves 324 during the upward movement of the inner mold 302. At this time, the stepper motor drives the connecting shaft 205 to rotate, the rotating section 208 fixedly connected with the connecting shaft 205 also rotates, and the rotating speed is the same as that of the inner mold 302.

Driven by the rotating section 208 and the inner mold 302, the lower end of the forging rotates, and the forging is twisted, so that a forging streamline after the forging is formed is spiral, the torsional strength of the shaft forging of the fan in the working environment is improved, the possibility of damage of the forging is reduced, and the service life of the forging is prolonged.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims (7)

1. The net forming forging die for shaft forgings is characterized in that: the forging die comprises an upper die (200) and a lower die (300), wherein the lower die (300) comprises a plurality of half dies (304) and a fixing piece (303) for fixing the relative positions of the half dies (304), the lower die (300) is provided with a die cavity (301) for forming a forging piece, the die cavity (301) comprises a concave ring cavity (308) for forming a convex ring (103), the plurality of half dies (304) are circumferentially arranged and encircle to form the concave ring cavity (308), two adjacent half dies (304) are mutually attached, the attaching surfaces of the two half dies (304) are parting surfaces of the two half dies (304), and the parting surfaces are parallel to the central axis of the die cavity (301); the side wall of one end of the half mould (304) deviating from the mould cavity (301) is abutted against the side wall of the cavity (312) of the fixing piece (303); the fixing piece (303) comprises an outer die (318) provided with a cavity (312), an inner die (302) is arranged in the outer die (318), the die cavity (301) is arranged on the inner die (302) or is arranged on the inner die (302) and the outer die (318), the inner die (302) comprises at least two half dies (304), one side, far away from the die cavity (301), of the half dies (304) is abutted against the inner wall of the cavity (312) of the outer die (318), and the outer die (318) is used for being fixedly connected with a lower working platform (501) of a forging press and the lower ejection of the lower working platform (501) is aligned with the inner die (302); the die cavity (301) further comprises a first cylindrical cavity (306) for forming the shaft section (100), a round platform cavity (307) for forming the round platform section (101) and a second cylindrical cavity (309) for forming the shaft platform section (102), the concave annular cavity (308) is located between the second cylindrical cavity (309) and the round platform cavity (307) and is coaxially arranged, the cavity (312) of the outer die (318) is cylindrical, the axial length of the cavity is larger than that of the inner die (302), the inner die (302) is located in the cavity (312) and is located at one end of the outer die (318), one end of the inner die (302) provided with the second cylindrical cavity (309) is located at the end position of the outer die (318), the round platform cavity (307) and the second cylindrical cavity (309) are arranged in the inner die (302), and the space, where the inner die (302) is not contained in the cavity (312) of the outer die (318), is the first cylindrical cavity (306).

2. A net forming die for shaft forgings as defined in claim 1, wherein: the fixing piece (303) comprises a plurality of bolts, and two adjacent half dies (304) are fixedly connected through the bolts.

3. A net forming die for shaft forgings as defined in claim 1, wherein: the fixing piece (303) comprises two semi-rings (311), the two semi-rings (311) are abutted and encircle to form a ring, and the two semi-rings (311) are detachably and fixedly connected.

4. A net forming die for shaft forgings as defined in claim 1, wherein: the inner mold (302) further comprises a bottom plate (305), wherein the bottom plate (305) is abutted against an inward side wall of the half mold (304) and/or an end surface facing away from the upper mold (200).

5. A net forming die for shaft forgings as defined in claim 1, wherein: the die halves (304) include first circular arc board (320) and second circular arc board (321) of laying along die cavity (301) axial, first circular arc board (320) axial one end and second circular arc board (321) axial one end butt, round platform cambered surface (322) have been seted up to first circular arc board (320), and round platform cambered surface (322) of all first circular arc boards (320) are constituteed the lateral wall of round platform chamber (307), all the lateral wall of second circular arc board (321) is constituteed the lateral wall of second cylindrical chamber (309), concave ring chamber (308) are including a plurality of arc recess (323) of seting up in die halves (304), arc recess (323) are seted up in first circular arc board (320) and/or second circular arc board (321).

6. A net forming die for shaft forgings as defined in claim 5, wherein: the lower die (300) further comprises a driving mechanism (400) for driving the inner die (302) to coaxially rotate relative to the outer die (318), the direction of torque applied to two ends of the forging piece by the rotation of the inner die (302) is the same as the direction of torque applied to two ends of the forging piece in the working state, and the driving mechanism (400) comprises a power assembly (401) for providing power for the rotation of the inner die (302) and a transmission assembly (402) for transmitting the power of the power assembly (401) to the inner die (302);

the power assembly (401) comprises an electric motor (403) fixed relative to the outer die (318), a driving gear ring (405) rotating relative to the outer die (318) and a transmission gear (406) meshed with the driving gear ring (405), a driving gear (404) is coaxially and fixedly connected with a main shaft of the electric motor (403), the driving gear (404) is meshed with the driving gear ring (405), and the transmission gear (406) is rotationally connected with a lower working platform (501) of the forging press and is used for transmitting power to the transmission assembly (402);

the number of the transmission assemblies (402) is the same as that of the half molds (304), each transmission assembly (402) comprises a transmission shaft (407) parallel to the central axis of the inner mold (302), the transmission shafts (407) slide along the direction close to or far away from the half molds (304), the transmission shafts (407) are coaxially and fixedly connected with an execution gear, a plurality of tooth grooves are formed in the outer walls of the half molds (304) to form incomplete gear rings, the execution gear is meshed with the incomplete gear rings, one end of each transmission shaft (407) is connected with the corresponding transmission gear (406) through a coupling (413), the coupling (413) is a telescopic double-universal-joint coupling, and the outer mold (318) is fixedly connected with a hydraulic cylinder (415) for driving the transmission shafts (407) to slide.

7. A net forming die for shaft forgings as defined in claim 6, wherein: every transmission shaft (407) coaxial fixedly connected with two carry out the gear, be located two carry out the gear of same transmission shaft (407) and be first carry out gear (408) and second carry out gear (409) respectively, first circular arc board (320) and second circular arc board (321) are provided with incomplete ring gear, set up in incomplete ring gear of first circular arc board (320) is first incomplete ring gear (410), set up in incomplete ring gear of second circular arc board (321) is second incomplete ring gear (411), first carry out gear (408) and the meshing of first incomplete ring gear (410), second carry out gear (409) and the meshing of second incomplete ring gear (411), the pitch diameter of first carry out gear (408) is less than the pitch diameter of second carry out gear (409).

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