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CN-122007303-A - Upsetting-extruding composite forming process for flange shaft parts

CN122007303ACN 122007303 ACN122007303 ACN 122007303ACN-122007303-A

Abstract

The invention discloses a upsetting-extruding composite forming process of flange shaft parts, which comprises the steps of S1, blanking, S2, heating, namely, heating the short blank to 1100-1230 ℃, S3, upsetting, namely, forging the upsetting blank by adopting a multi-station hot die forging press, S4, pre-upsetting, namely, upsetting the upsetting blank into a pre-upsetting-extruding forging blank through a pre-upsetting die, S5, upsetting and extruding the pre-upsetting-forging blank into a forging with flash through a upsetting and extruding die, wherein the upsetting and extruding step comprises an upsetting upper die and a upsetting and extruding lower die, the upsetting and extruding lower die comprises an inner core of an extruding lower die, an outer ring of the upsetting lower die and an ejector rod of the upsetting and extruding lower die, and S6, trimming, namely, cutting off excessive flash of the forging with flash through a trimming die after upsetting and extruding. The invention can solve the problems that the rolling ratio is too large in cross wedge rolling forming, the characteristics of the disc part cannot be formed, repeated material gathering is needed in local upsetting forming, and the material utilization rate is low.

Inventors

  • YU YI
  • ZHANG TIESUO
  • GAO HONGLIN
  • LIU XIAOJING
  • CAI TIANBAO

Assignees

  • 陕西法士特齿轮有限责任公司

Dates

Publication Date
20260512
Application Date
20260206

Claims (7)

  1. 1. The upsetting-extruding composite forming process for the flange shaft parts is characterized by comprising the following steps of: S1, blanking, namely sawing a round bar material into a short blank meeting the requirements, wherein the weight of the short bar material is the weight of a forge piece to be formed plus the weight of flash; s2, heating, namely heating the short blank to 1100-1230 ℃ by using an intermediate frequency induction heating furnace; The upsetting step is to put the heated short bar material on a lower upsetting table, forge the upsetting blank by adopting a multi-station hot die forging press, wherein the upsetting table is of a columnar structure, and two continuous sinking tables are arranged on the lower upsetting table, wherein the upper sinking table is used for positioning the short bar material, and the lower sinking table is used for extruding the short bar material out of a step positioned on a pre-upsetting lower die; The method comprises the steps of S4, pre-upsetting, namely upsetting and extruding an upsetting blank into a pre-upsetting and extruding forging blank through a pre-upsetting and extruding die, wherein before pre-upsetting and extruding, the upsetting blank is firstly placed in the center of a pre-upsetting and extruding lower die, and a bulge with a conical surface at the lower part of the upsetting blank is formed and positioned in a conical surface cavity of the pre-upsetting and extruding lower die; The upsetting extrusion molding process comprises upsetting extrusion molding process steps of upsetting extrusion forging stock to be a forging with Z-shaped flash meeting the drawing requirement through an upsetting extrusion molding die, and specifically comprises upsetting extrusion molding upper die (1) and upsetting extrusion molding lower die, wherein the upsetting extrusion molding upper die (1) and an upper die holder are fixed on an upper sliding block of a hot die forging press and can move up and down along with the upper sliding block, the upsetting extrusion molding lower die comprises upsetting extrusion molding lower die inner cores (2), upsetting extrusion molding lower die outer rings (3) and upsetting extrusion molding lower die ejector rods (4) which are respectively fixed on a lower die holder of a hot die forging press, and the upsetting extrusion molding lower die inner cores (2) are of a double-step structure with large upper part and small lower part; Heating the upsetting lower die outer ring (3) to 300-500 ℃ before upsetting, placing the upsetting lower die outer ring into a furnace, keeping the temperature for 1.5-2 hours, heating the upsetting lower die outer ring to be large, installing the upsetting lower die inner core into the upsetting lower die outer ring, and naturally cooling to form an integral structure with the upsetting lower die inner core (2) and the upsetting lower die outer ring (3); and S6, trimming, namely cutting off redundant flash through a trimming die to obtain the forge piece meeting the drawing requirements.
  2. 2. The upsetting extrusion composite forming process for flange shaft parts according to claim 1, wherein in S1, the ratio of the short blank length h to the blank diameter d is 1.2-2.5, and the short blank size phi 80 x 73/6.83kg (+ 40g/-20 g).
  3. 3. The upsetting-extruding composite forming process for the flange shaft type part according to claim 1, wherein in S3, the diameter d2 of the upper sinking table is phi 82, the depth is 3mm, and the diameter d11 of the lower sinking table is phi 47.3, and the depth is 18mm.
  4. 4. The upsetting-extruding composite forming process for flange shaft parts according to claim 1, wherein in S4, the flash structure of the pre-upsetting-extruding die is arranged in an arc shape.
  5. 5. The upsetting-extruding composite forming process for the flange shaft part according to claim 1 is characterized in that in S5, the upsetting-extruding lower die inner core (2) and the upsetting-extruding lower die outer ring (3) are in interference fit, namely the outer diameter d41 of the upper end of the upsetting-extruding lower die inner core (2) is larger than the inner diameter d42 of the upper end of the upsetting-extruding lower die outer ring (3), and d 41-d42=0.2-0.3 mm.
  6. 6. The upsetting-extruding composite forming process of the flange shaft type part according to any one of claims 1 to 5, wherein in the step S5, the Z-shaped flash comprises a bridge part and a bin part, the bridge part is of an L-shaped structure consisting of an inclined section and a horizontal section, the bin part and the upper end of the inclined section of the bridge part form a Z-shaped structure together, and the bin part and the inclined section of the bridge part form a certain angle; The horizontal section of the bridge part sequentially comprises a front part and a rear part with the widths of b2 and b1 in the direction facing the forge piece, wherein b2 is smaller than b1, the width of the inclined section of the bridge part is b3, b3 is smaller than or equal to b2, and the width of the bin part is b4, b4 is larger than b1; The angle between the bin part and the bridge part inclined section is 92-95 degrees, and the opposite sides of the bridge part inclined section are parallel to each other; The inclined section from the bin part to the bridge part and the transition part from the inclined section to the horizontal section of the bridge part are arc-shaped.
  7. 7. The upsetting-extruding composite forming process of the flange shaft type part according to claim 6 is characterized in that the rear width b1 of the horizontal section of the bridge part is set to be 3-5 mm, the front width b2 of the horizontal section of the bridge part and the width b3 of the inclined section of the bridge part are both set to be 2-3 mm, the distance h4 from the lower end of the bin part to the bottom end of the front part of the horizontal section of the bridge part is more than or equal to 10mm, and the width b4 of the bin part is more than or equal to 5mm.

Description

Upsetting-extruding composite forming process for flange shaft parts Technical Field The invention belongs to the technical field of forging processes, and relates to a upsetting-extruding composite forming process for flange shaft parts. Background Referring to fig. 1, a diagram of an engine shaft forging of a new energy automobile is shown, the engine shaft forging is a flange shaft part formed by combining a shaft part with a diameter d1 and a disc part with a diameter d2, the shaft part is thin and long, and the diameter d2 of the disc part is far greater than the diameter d1 of the shaft part. When producing such flange shaft parts, free forging or roll forging is generally used for manufacturing blanks, bar stocks with proper specifications are selected, the rod parts are drawn out, and then the disc parts are formed in an upsetting mode. However, if blank making equipment such as free forging and roll forging machines and the like is not used, only cross wedge rolling forming or local upsetting forming can be selected in the prior art mode when the flange shaft part is to be produced. The prior art can refer to the Chinese patent publication No. CN110508743 discloses a long rod flange shaft forging process, which adopts a first gathering-second gathering-pre-forging-final forging-trimming mode to produce flange shaft forgings on a flat forging machine, but for the flange shaft parts shown in figure 1, the height-diameter ratio (the length of a blank of a formed part/the diameter of the blank) of the formed part reaches more than 26, more than 4 gathering times are needed, the process route is long, the production efficiency is low, if the material diameter is increased, the gathering is not needed, but the processing allowance of the rod part is large, and the material utilization rate is low. If the cross wedge rolling forming mode is selected for production, the step drop is large, the rolling ratio is too large, and some characteristics of the disc part cannot be formed. In view of this, it is highly necessary to study a new automotive engine shaft forging forming process. Disclosure of Invention The invention aims to provide a upsetting-extruding composite forming process for flange shaft parts, which aims to solve the problems that the rolling ratio is too large and the characteristics of a disc part cannot be formed in cross wedge rolling forming and the problems that repeated material gathering and low material utilization rate are required in local upsetting forming. In order to achieve the above purpose, the invention adopts the following technical scheme: a upsetting-extruding composite forming process for flange shaft parts comprises the following steps: S1, blanking, namely sawing a round bar material into a short blank meeting the requirements, wherein the weight of the short bar material is the weight of a forge piece to be formed plus the weight of flash; s2, heating, namely heating the short blank to 1100-1230 ℃ by using an intermediate frequency induction heating furnace; The upsetting step is to put the heated short bar material on a lower upsetting table, forge the upsetting blank by adopting a multi-station hot die forging press, wherein the upsetting table is of a columnar structure, and two continuous sinking tables are arranged on the lower upsetting table, wherein the upper sinking table is used for positioning the short bar material, and the lower sinking table is used for extruding the short bar material out of a step positioned on a pre-upsetting lower die; The method comprises the steps of S4, pre-upsetting, namely upsetting and extruding an upsetting blank into a pre-upsetting and extruding forging blank through a pre-upsetting and extruding die, wherein before pre-upsetting and extruding, the upsetting blank is firstly placed in the center of a pre-upsetting and extruding lower die, and a bulge with a conical surface at the lower part of the upsetting blank is formed and positioned in a conical surface cavity of the pre-upsetting and extruding lower die; s5, upsetting and extruding the pre-upsetting and extruding forging stock into a forging with Z-shaped flash meeting the drawing requirements through a upsetting and extruding die; the upsetting and extruding step die comprises an upsetting and extruding upper die and an upsetting and extruding lower die, wherein the upsetting and extruding upper die and an upper die holder are fixed on an upper sliding block of a hot die forging press together and can move up and down along with the upper sliding block; Heating the outer ring of the upsetting lower die to 300-500 ℃ before upsetting, placing the outer ring into a furnace chamber, keeping the temperature for 1.5-2 hours, heating the outer ring of the upsetting lower die to be large, installing the inner core of the upsetting lower die into the outer ring of the upsetting lower die, and naturally cooling the inner core of the upsetting lower die and the outer ring of the u