CN110814248B - Flash-free hot die forging forming process for front shell forging of automobile differential - Google Patents
Flash-free hot die forging forming process for front shell forging of automobile differential Download PDFInfo
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- CN110814248B CN110814248B CN201910957718.2A CN201910957718A CN110814248B CN 110814248 B CN110814248 B CN 110814248B CN 201910957718 A CN201910957718 A CN 201910957718A CN 110814248 B CN110814248 B CN 110814248B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/02—Die forging; Trimming by making use of special dies ; Punching during forging
- B21J5/022—Open die forging
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
- B21J1/02—Preliminary treatment of metal stock without particular shaping, e.g. salvaging segregated zones, forging or pressing in the rough
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/008—Incremental forging
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/06—Methods for forging, hammering, or pressing; Special equipment or accessories therefor for performing particular operations
- B21J5/08—Upsetting
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J7/00—Hammers; Forging machines with hammers or die jaws acting by impact
- B21J7/02—Special design or construction
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J9/00—Forging presses
- B21J9/02—Special design or construction
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- Forging (AREA)
Abstract
The invention discloses a flash-free hot die forging forming process for a front shell forging of an automobile differential, which comprises the following process forming steps: blank-first upsetting-second upsetting-finish forging; placing the blank into a primary upsetting die, wherein a forming rod part of the blank is placed into a lower die cavity of the primary upsetting die, a head part of the blank is placed into an upper die cavity of the primary upsetting die, the forming rod part of the blank does not participate in upsetting basically, the head part of the blank is upset, and the blank is upset to form a primary upsetting piece; the secondary upsetting is to continue upsetting the primary upsetting piece, the primary upsetting piece is placed into a secondary upsetting die, and the primary upsetting piece is upset to form a secondary upsetting piece; the final forging is to put the secondary upsetting part into a final forging die and upset the secondary upsetting part to form a forged piece; the invention adopts two-step forming and upsetting to meet the requirement of forming and distributing the forged piece and realize flash-free forging and forming of a larger shell part with a more complex shape. The forming process has the advantages of simple mold structure, good filling of the forge piece, no defects of folding, error and the like, and convenient operation.
Description
Technical Field
The invention belongs to the technical field of forging, and relates to a flash-free hot die forging forming process of a front shell forging of an automobile interaxle differential.
Background
The process steps of the hot die forging forming process of the existing automobile differential front shell forging are shown in the figure 1: blank-upsetting-preforging (with flash) -final forging (with flash) -trimming.
The existing forming process has the defects that:
1. the positioning from upsetting to pre-forging is inaccurate, materials are easy to deflect during forming, the situation that one side is provided with more materials (more materials are discharged into fins) and one side is provided with less materials can occur, and the defect that the forged piece on the side with less materials is not full can occur;
2. the upper die cavity is shallow, so that the error of the forge piece is difficult to detect, the error defect of the forge piece is easy to occur, and a defective product is easy to produce;
3. the process adopts open forging (with flash), the rod part is completely extruded and formed, and the lower end of the rod part of the forged piece is difficult to fill, so that a small step of the rod part cannot be precisely formed;
4. the production efficiency is low: heavy, slow manual operation; and the edge cutting is also needed, so that the production efficiency is low.
Disclosure of Invention
The invention overcomes the problems in the prior art, and provides a flash-free hot die forging forming process of the front shell forging of the automobile differential in order to improve the material utilization rate, the forging quality and the production efficiency.
In order to solve the technical problems, the invention is realized by adopting the following technical scheme, which is described by combining the accompanying drawings as follows:
a flash-free hot die forging forming process for a front shell forging of an automobile differential comprises the following process forming steps: blank-first upsetting-second upsetting-finish forging;
during the primary upsetting, the blank is placed into a primary upsetting die, wherein the formed rod part of the blank is placed into a lower die cavity of the primary upsetting die, the head part of the blank is placed into an upper die cavity of the primary upsetting die, the formed rod part of the blank basically does not participate in upsetting, the head part of the blank is upset, and the blank is upset to form a primary upsetting piece;
the secondary upsetting is to continuously upset the primary upsetting piece on the basis of forming the primary upsetting piece by primary upsetting, place the primary upsetting piece into a secondary upsetting die and upset the primary upsetting piece to form a secondary upsetting piece;
and the final forging is to continue upsetting the secondary upsetting piece on the basis of forming the secondary upsetting piece by secondary upsetting, place the secondary upsetting piece into a final forging die, and upset the secondary upsetting piece to form a forging piece.
The shapes of the primary upsetting piece and the secondary upsetting piece in the technical scheme have the following specific design requirements:
(1) calculating the material volumes of the head part and the forming rod part of the forge piece, and determining the blank volume requirements of the two parts;
(2) after the volume calculation is finished, the diameter phi A3 of the blank is selected according to the following three principles:
the first point principle is as follows: during primary upsetting, the blank of the forming rod part is placed in the lower die cavity and does not participate in upsetting basically, the blank is only required to be prevented from bending during upsetting of the head forming blank, and the length-diameter ratio of the blank can be slightly larger than 2.5 because the upper surface of the blank is limited by a die; but the billet length-diameter ratio of the free upsetting part is not more than 2.5;
the second point principle is as follows: the materials with the volume required by the forming rod part of the blank are basically placed into the lower cavity of the primary upsetting die;
the third principle is as follows: the known forged piece shank diameter Φ a ═ the two-shot upset shank diameter Φ a1+ about 0.6mm ═ the one-shot upset shank diameter Φ a2+ about 1.2mm ═ the blank diameter Φ A3+ about 1.8 mm;
(3) designing the shapes of a primary upsetting piece and a secondary upsetting piece according to the principle that upsetting is mainly used in each sequence of forming;
(4) the head shapes of the primary upsetting piece and the secondary upsetting piece are designed to be frustum-shaped;
according to the technical scheme, the secondary upsetting part is placed in a finish forging die, the shape of a rod part cavity of a lower die of the finish forging die is matched with the shape of a rod part of the secondary upsetting part, and the secondary upsetting part is accurately positioned in the finish forging die.
The primary upsetting part is placed in a secondary upsetting die, and the shape of a rod part cavity of a lower die of the secondary upsetting die is matched with the shape of a rod part of the primary upsetting part, so that the primary upsetting part is accurately positioned in the secondary upsetting die;
in the technical scheme, guide structures for preventing the dies from being mistaken are designed on the upper die and the lower die of the secondary upsetting die;
the upper die and the lower die of the finish forging die are respectively provided with a guide structure for preventing the die from being mistaken
Compared with the prior art, the invention has the beneficial effects that:
the invention uses the forming characteristic of the horizontal forging machine step-by-step upsetting for reference, adopts two-step forming upsetting on the vertical hot die forging press to realize the requirement of forming and distributing the forged pieces, and realizes the flash-free forging forming of larger shell parts with more complicated shapes.
The forming process has the advantages of simple mold structure, good filling of the forge piece, no defects of folding, error and the like, and convenient operation. The material utilization rate, the service life of the die, the production efficiency and the quality of the forge piece are improved to a great extent, the cost is saved, and the requirement of mass production is met. Specific data: the weight of the forging is reduced by 0.42kg (the precision of the forging is improved, and the machining allowance is reduced); and (3) reducing material consumption: 2.877 kg/piece; the forging beat is improved: the temperature is increased to 7S from 10 seconds; the forging error is controlled within 0.8 mm; the trimming process is omitted: 1 person is reduced, 1 set of trimming die is omitted, and 1 device is omitted; production efficiency promotes, and the shift is produced: the lifting is from 600 pieces/shift to 1000 pieces/shift.
Drawings
The invention is further described with reference to the accompanying drawings in which:
FIG. 1 is a hot die forging forming process step diagram of a front shell forging of an existing automobile differential;
FIG. 2 is a forming step diagram of the flash-free hot die forging forming process of the automobile differential front shell forging of the invention;
FIG. 3 is a flash-free hot die forging forming die diagram of the flash-free hot die forging forming process for the automobile differential front shell forging of the invention;
Detailed Description
The invention is described in detail below with reference to the attached drawing figures:
the flash-free hot die forging forming process for the front shell forging of the automobile differential mechanism, provided by the invention, references the forming characteristic of gradual gathering of a horizontal forging machine, so that the distribution of finish forging forming is more accurate, and the upsetting of a bar material exceeding the upsetting ratio is realized without bending. The process step diagram of the invention is shown in figure 2: blank, primary upsetting piece, secondary upsetting piece and final forging piece. The secondary forming upsetting is utilized to ensure that the upsetting does not deform, and the forming process is applied to perfectly realize flash-free precision forging forming of complex shell parts.
In order to realize the forming of the small step at the tail end of the forged piece rod, a rod material with the diameter similar to that of the forged piece rod needs to be selected, so that the length-diameter ratio of the blank is far larger than 2.5 (when the length-diameter ratio of the blank is larger than the value, the blank is bent), the blank cannot be formed by using the conventional free upsetting process, and the forming upsetting process (after the blank is limited by a die, the rod material with the length-diameter ratio exceeding the upsetting ratio cannot be bent during upsetting forming) needs to be adopted. The method has the advantages that flash-free hot die forging forming of the parts is realized, blanks with proper diameters need to be selected, and the shapes of the primary upsetting part and the secondary upsetting part are reasonably designed, and the method specifically comprises the following steps:
1. calculating the material volumes of the head part and the rod part of the forging piece, and determining the blank volume requirements of the two parts;
the forging piece is formed by finish forging
2. After the volume calculation is finished, selecting the diameter phi A3 of the blank according to the three-point principle:
(1) during one-time upsetting, the blank of the forming rod part is placed in the lower die cavity, does not participate in upsetting basically, and only needs to ensure that the blank formed by the head part is not bent during upsetting (because the upper part of the blank is also limited by a die, the length-diameter ratio of the blank can be slightly larger than 2.5 at the moment, but the length-diameter ratio of the blank at the free upsetting part is not larger than 2.5);
(2) the materials with the required volume formed by the rod part are basically placed into a lower cavity of the primary upsetting die;
(3) the principle is expressed as "Φ a (forged shank diameter, known) ═ Φ a1 (secondary upset shank diameter) + about 0.6mm ═ Φ a2 (primary upset shank diameter) + about 1.2mm ═ Φ A3 (billet diameter) + about 1.8 mm".
3. The shapes of the primary upsetting piece and the secondary upsetting piece are designed according to the principle that upsetting is mainly used in each sequence of forming.
4. The head shape of the primary upsetting piece and the head shape of the secondary upsetting piece are designed into a frustum shape: firstly, upsetting can be prevented from bending; secondly, the material of the mold parting part of the mold is less, and burrs are not easy to appear.
5. The lower part of the head of the primary upsetting piece needs free upsetting forming, and the purpose is to smoothly discharge the primary upsetting piece.
The shape of the primary upset part and the structure of the die when the upset ratio is exceeded (the shape of the part determines the structure of the die);
the shape of the secondary upset part and the structure of the die (the shape of the part determines the structure of the die) which are suitable for final forming;
in order to realize flash-free precision forming of finish forging, high burrs are not generated at die parting positions of an upper die and a lower die, forging force is reduced, accurate positioning must be realized in each step, and uniform material distribution in the circumferential direction is guaranteed. The design of the positioning needs to be pushed from the subsequent to the preceding (because the shape of the final forging is known, the shape of the preceding needs to be designed according to the shape of the subsequent), which is described below with reference to fig. 2 and 3.
Positioning of each sequence:
the purpose is to ensure that the preorder part is kept upright and does not move when being placed in a subsequent die (each preorder part is basically a revolving body, and the preorder part can be kept into concentric circles when being placed in the die, so that the materials are inevitably uniform when flowing to the periphery).
1. And (3) accurately positioning the secondary upset part to the finish forging die: positioning is mainly carried out by matching the shape of a rod part cavity of the finish forging lower die with the shape of a rod part of a secondary upsetting part;
2. and (3) accurately positioning the primary upsetting piece to the secondary upsetting die: mainly by matching the shape of a rod part cavity of the secondary upsetting lower die with the shape of a rod part of the primary upsetting part for positioning;
3. accurate positioning of the blank to a primary upsetting die: the specification of the diameter of the blank is selected as mentioned above, and the positioning mode is also the principle of diameter matching.
The upper die and the lower die are not staggered:
if the upper die and the lower die are staggered, the material of the head part and the material of the rod part are not concentric for the blank positioned by the rod part of the lower die, so that the material distribution is uneven. Particularly, if the 'secondary upsetting piece' is staggered up and down, burrs can be formed on one side of the forged piece during finish forging forming, and one side of the forged piece is not full. Therefore, the dies of the upper die and the lower die of the 'secondary upsetting die' and the 'finish forging die' are both designed with the guide structures for preventing the dies from being mistakenly stamped, and referring to fig. 3, in order to ensure uniform material distribution and prevent the secondary upsetting die from generating burrs and being not full of defects, the guide die structures of the upper die and the lower die of the finish forging die are designed.
Claims (4)
1. A flash-free hot die forging forming process for a front shell forging of an automobile differential mechanism is characterized by comprising the following steps of:
comprises the following process steps: blank-first upsetting-second upsetting-finish forging;
two-step forming upsetting is adopted on a vertical hot die forging press;
during the primary upsetting, the blank is placed into a primary upsetting die, wherein the formed rod part of the blank is placed into a lower die cavity of the primary upsetting die, the head part of the blank is placed into an upper die cavity of the primary upsetting die, the formed rod part of the blank basically does not participate in upsetting, the head part of the blank is upset, and the blank is upset to form a primary upsetting piece;
the secondary upsetting is to continuously upset the primary upsetting piece on the basis of forming the primary upsetting piece by primary upsetting, place the primary upsetting piece into a secondary upsetting die and upset the primary upsetting piece to form a secondary upsetting piece;
the finish forging is to continue upsetting the secondary upsetting piece on the basis of forming the secondary upsetting piece by secondary upsetting, place the secondary upsetting piece into a finish forging die, and upset the secondary upsetting piece to form a forging piece;
the secondary upsetting part is placed in a finish forging die, and the shape of a rod part cavity of a lower die of the finish forging die is matched with that of a rod part of the secondary upsetting part, so that the secondary upsetting part is accurately positioned in the finish forging die;
the primary upsetting piece is placed into a secondary upsetting die, and the shape of a rod part cavity of a lower die of the secondary upsetting die is matched with the shape of a rod part of the primary upsetting piece, so that the primary upsetting piece is accurately positioned in the secondary upsetting die.
2. The flash-free hot die forging forming process of the automobile differential front shell forging piece according to claim 1, wherein the flash-free hot die forging forming process comprises the following steps:
the shape of the primary upsetting piece and the shape of the secondary upsetting piece have the following specific design requirements:
(1) calculating the material volumes of the head part and the forming rod part of the forge piece, and determining the blank volume requirements of the two parts;
(2) after the volume calculation is completed, the diameter Φ a3 of the blank is selected:
(3) designing the shapes of a primary upsetting piece and a secondary upsetting piece according to the principle that upsetting is mainly used in each sequence of forming;
(4) the head shapes of the primary upsetting piece and the secondary upsetting piece are designed to be frustum-shaped.
3. The flash-free hot die forging forming process of the automobile differential front shell forging piece according to claim 2, wherein the flash-free hot die forging forming process comprises the following steps:
the diameter phi A3 of the blank is selected according to the following three-point principle:
the first point principle is as follows: during primary upsetting, the blank of the forming rod part is placed in the lower die cavity and does not participate in upsetting basically, the blank is only required to be prevented from bending during upsetting of the head forming blank, and the length-diameter ratio of the blank can be slightly larger than 2.5 because the upper surface of the blank is limited by a die; but the billet length-diameter ratio of the free upsetting part is not more than 2.5;
the second point principle is as follows: the materials with the volume required by the forming rod part of the blank are basically placed into the lower cavity of the primary upsetting die;
the third principle is as follows: the known forged shank diameter Φ a is the two-upset shank diameter Φ a1+ about 0.6mm and the one-upset shank diameter Φ a2+ about 1.2mm is the blank diameter Φ A3+ about 1.8 mm.
4. The flash-free hot die forging forming process of the automobile differential front shell forging piece according to claim 1, wherein the flash-free hot die forging forming process comprises the following steps:
guide structures for preventing the secondary upsetting die from being mistakenly stamped are designed on the upper die and the lower die;
and guide structures for preventing die errors are designed on the upper die and the lower die of the finish forging die.
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| CN201910957718.2A CN110814248B (en) | 2019-10-10 | 2019-10-10 | Flash-free hot die forging forming process for front shell forging of automobile differential |
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| CN201910957718.2A CN110814248B (en) | 2019-10-10 | 2019-10-10 | Flash-free hot die forging forming process for front shell forging of automobile differential |
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| CN113634707B (en) * | 2021-06-29 | 2023-04-14 | 中国航空工业标准件制造有限责任公司 | Preparation method for 302 stainless steel self-locking nut hot heading forming |
| CN114393167A (en) * | 2022-01-06 | 2022-04-26 | 钢铁研究总院 | Upsetting forming die and process for flanged hollow long shaft |
| CN115945621A (en) * | 2022-12-27 | 2023-04-11 | 无锡派鑫航空科技有限公司 | Die forging forming die for aluminum alloy petroleum pipeline valve body and forming method thereof |
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| CN101947634A (en) * | 2010-09-03 | 2011-01-19 | 东风汽车有限公司 | Forging process for flange of half shaft of automobile rear axle |
| CN106964735A (en) * | 2017-03-31 | 2017-07-21 | 武汉理工大学 | A kind of super large ratio of height to diameter metal stock upsetting formation method |
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| JPS6123548A (en) * | 1984-07-11 | 1986-02-01 | Goto Tanko Kk | Forging method of flanged axle |
| JPH11309540A (en) * | 1998-04-23 | 1999-11-09 | Fuji Oozx Inc | Forming method of engine valve |
| CN101342549A (en) * | 2008-08-21 | 2009-01-14 | 河南英威东风机械制造有限公司 | Front casing workblank hot extrusion technique for differential gear of automobile and molding mould thereof |
| RU2419505C1 (en) * | 2009-10-05 | 2011-05-27 | Государственное образовательное учреждение высшего профессионального образования Московский государственный индустриальный университет | Method of producing rod-plus-flange forgings |
| CN103878277A (en) * | 2012-12-21 | 2014-06-25 | 陕西宏远航空锻造有限责任公司 | Forging method of T-shaped shaft forging with ratio of length to diameter larger than 2.5 |
| CN104439027B (en) * | 2014-11-05 | 2016-06-01 | 许昌中兴锻造有限公司 | Transmission shaft fork axle new technique for forging |
| CN104801653A (en) * | 2015-04-09 | 2015-07-29 | 鹏驰五金制品（昆山）有限公司 | Cold-upsetting processing technology with flange bolt |
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| CN101947634A (en) * | 2010-09-03 | 2011-01-19 | 东风汽车有限公司 | Forging process for flange of half shaft of automobile rear axle |
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