RU2300439C2 - Method for making ring-like cone gear wheel forged pieces - Google Patents

Abstract

FIELD: plastic working of metals, namely forging production, manufacture of forged pieces of ring-like cone gear wheels with diameter 638 mm and with wide massive rim.

SUBSTANCE: method comprises steps of preliminarily upsetting initial blank with diameter 250 mm and length 335 mm; then subjecting upset blank to non-complete open broaching and its further die forging. All operations are realized in the same die set. Preliminary upsetting is performed on flat striker with diameter 350 mm till achieving diameter of upset blank equal to said value. Striker is arranged in central portion of die set impression before broaching and after broaching it is removed. Non-complete open broaching of upset blank is realized by means of detachable cone broach with mounting land having diameter 270 mm.

EFFECT: improved quality of produced forged pieces.

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Description

The invention relates to the processing of metals by pressure and can be used in forging and stamping in the manufacture of forgings for parts with a wide massive rim with a diameter of 400 ... 600 mm such as gears, disks, rings and flanges.

A known method for open flashing cylindrical billets with piercing having a tapered side surface [A.S. 518262 USSR MKI B21J 5/10; B21K 1/32. The method of open flashing cylindrical workpieces]. The resulting semi-finished product can be used for subsequent bulk stamping of annular forgings of large dimensions. The disadvantage of this method is the high complexity of the full processing cycle.

A known method of manufacturing in one stamp products of the type of rings with a massive rim by preliminary incomplete open firmware of the original billet with a conical stitch and subsequent volumetric stamping of the semi-finished product (prototype) [A.S. 1000151 USSR, MKI V21K 1/28; B21J 5/02. A method of manufacturing products such as rings with a massive rim]. In the manufacture of rings with a high massive rim at the final stage of the firmware, the peripheral portion of the semi-finished product is forced to be wrapped in the annular cavity of the stamp engraving and the metal is given the predominantly axial direction of the flow, and the piercing is removed from the stamp before volume stamping.

The main disadvantage of this method is the applicability for the nomenclature of high annular forgings, characterized mainly by the axial (vertical) orientation of the largest sizes of the rim section [Grigoryev GD, Kaplunov BG, Felde AA, Zuev SP A method of stamping ring products and a tool for its implementation. // Forging and stamping. 1991, No. 2. - S.30-32]. In addition, when flashing firmware on a conical firmware, there is an uneven radial flow of metal due to the presence of oblique ends in the original workpiece (Fig. 1), as well as the likelihood of the workpiece being misaligned on the firmware and the inability to restore it during the firmware due to early firmware implementation in the workpiece (figure 2, the left side). Due to the non-uniform flow of metal when wrapping the peripheral section of the workpiece, an undercut is formed on the inner surface of the semifinished product wall (Fig. 2, right side), which during final stamping often leads to a “clamp” defect (Fig. 3). Such defect formation is enhanced by the production of annular forgings with a wide massive rim by this method.

An object of the invention is to improve the quality and expansion of the range of annular forgings of bevel gears obtained in this way by changing the nature of the formation of the semi-finished product by creating a more uniform and intense metal flow in the radial direction.

The stated technical problem is achieved by the fact that in the method of stamping ring-shaped forgings of bevel gears with a diameter of 638 mm, preliminary pre-settlement of the initial billet with a diameter of 250 mm and a length of 335 mm is carried out, incomplete open piercing of the deposited billet and subsequent volumetric stamping, which are carried out in one stamp, with preliminary draft they are carried out on a flat striker having a diameter of 350 mm, until the diameter of the upset workpiece reaches the specified value of the diameter of the flat striker, which I place before flashing t in the central part of the brook of the stamp, and after flashing it is removed from the stamp, and the incomplete open firmware of the deposited workpiece is carried out with a removable conical piercing with an installation pad having a diameter of 270 mm.

Thanks to the introduction of this feature, a new property appears - a more uniform and intense metal flow in the radial direction with successive upsetting and incomplete open piercing, which ensures redistribution of the workpiece masses in accordance with the product configuration, eliminates the formation of undercut on the semi-finished product and the “clamp” defect on the ring-shaped forgings with wide rim. This allows us to conclude that this technical solution meets the criterion of "inventive step".

The invention is illustrated by drawings, where Fig. 4 shows a stamp and an initial blank before deformation on a flat striker (left side) and in the final stage of deformation (right side); figure 5 - the beginning (left side) and the end of the deformation of the pre-upset workpiece on a conical piercing (right side); figure 6 - the beginning of the volumetric stamping of the semi-finished product in the stream of the stamp (left side) and the end of volumetric stamping (the right part); Fig.7 - prefabricated forgings; on Fig - finished forging.

The method is as follows.

A stamp is used, consisting of the upper block 1 and the lower block 2. On the surfaces of the collision of the blocks, working streams (engraving) of the stamp are made.

When the upper block 1 is raised (Fig. 4), a removable striker 3 is mounted on the lower block 2 in its central cavity. The workpiece 4 is coaxially mounted on the striker 3. When the upper block 1 is lowered (the equipment moves), the workpiece settles. Upon reaching the specified dimensions of the deposited workpiece (diameter of the striker D), the upper block 1 is raised to its original position. The workpiece is lifted in the creek of the stamp above the striker. In a known manner, for example with ticks, the hammer 3 is removed from the stream of the stamp.

With a raised upper block 1 (Fig. 5), a conical removable piercing 5 with a mounting pad diameter of 270 mm is installed on the lower block 2 in its central cavity. When lowering the upper block 1 (the equipment moves in progress), incomplete open firmware occurs, accompanied by draft and distribution of the workpiece in the direction of further increasing its diameter. In the initial period of the second transition, precipitation predominates with poorly pronounced piercing, which makes it possible to restore alignment of the workpiece with it and thereby improves the uniformity of the subsequent metal flow. As the thickness of the metal layer between the plane of the stream of the upper block 1 and the piercing end 5 decreases, the meridional section of the stitched blank takes a bowl-shaped form with a predominantly radial orientation of the largest cross-sectional area of its peripheral part. The final stage of open firmware occurs in the absence of intensive wrapping of the metal in the die cavity and the uniform distribution of the mass of the intermediate workpiece in accordance with the shape of the ring forging in the plan.

Upon reaching the specified size of the intermediate workpiece, the upper block 1 is raised to its original position. Billet 4 is lifted in the die over the piercing stitch. In a known manner, for example with ticks, piercing 5 is removed from the brook of the stamp. The workpiece (semi-finished product) 4 is again lowered into the stream (Fig.6). Volumetric stamping of the intermediate billet is carried out to the size of the finished forgings, while the recess on the basting of the stream of the lower block serves as a compensator for the part of the metal displaced through the inner breaker bridge during the final shaping of the product. The stamped forging is removed from the stream of the stamp. Firmware 3 is again installed on the basting of the lower block 2.

The method allows to obtain annular forgings with a wide massive rim on one universal stamping unit. There is no need to use special dies and equipment for preliminary shaping of the workpiece. The volume of production preparation is reduced by at least 2 times.

Industrial test example.

The method was tested in the manufacture of forgings "bevel gear" (D100.08.003) with a diameter of 638 mm from steel 12KHN3A, weighing 115 kg on the machine: stamping hammer with MPCh10t press cutting force 10 MN. The forging die stream AEG 1300-7470 had an annular cavity with outer and inner diameters equal to 647 mm and 312 mm, respectively. The removable flat firmware is made with a diameter of 350 mm and a height of 59 mm. The conical removable piercing with a diameter of 420 mm and a height of 69 mm had an installation pad with a diameter of 270 mm. On a removable flat striker installed in the stream, the initial blanks with a diameter of 250 mm and a length of 335 mm were deformed. At the first transition, a free draft of the preform was performed (for 4 strokes) to a diameter approximately equal to the diameter of a flat piercing. In this case, the workpiece deposited to a height of 167 mm had a fairly uniform shape in plan. Upon reaching the specified dimensions of the deposited blank, it was removed from the stamp, the flat piercing was removed, the conical piercing was installed and the deposited blank was laid on it. At the second transition, an incomplete open firmware upsetting was performed (for 5 strokes). Here, in the initial period, deformation by sediment prevailed, which made it possible to restore the alignment of the workpiece and the piercing between impacts. From the moment the peripheral part of the semi-finished product reaches a height of 100 mm, the firmware was more intense, followed by further radial distribution. Upon reaching the diameter of the semi-finished product, approximately equal to the diameter of the stream (622 mm), it was removed from the stamp, the conical piercing was removed and the semi-finished product was placed in the stream. The shape and dimensions of the semi-finished product (Fig.7) corresponded to the dimensions of the cavity of the stream and the distribution of masses of the forging elements. As a result of deformation of the workpiece in the stamp (for 7 strokes), a fully formed forging with a burr and a jumper was obtained, which was then removed on the edging press (Fig. 8).

The results of technical control showed the absence of stamping defects and the compliance of forgings with acceptance requirements. Technology has been prepared for the serial production of forgings "bevel gear".

Using the proposed method of stamping for the manufacture of forgings such as rings has the following advantages compared with the prototype:

- the possibility of manufacturing annular forgings with a wide massive rim;

- elimination of the danger of forming a stamping defect in the form of a local or annular “clamp”.

Claims (1)

A method of stamping ring-shaped forgings of bevel gears with a diameter of 638 mm, characterized in that they pre-deposit the initial billet with a diameter of 250 mm and a length of 335 mm, incomplete open piercing of the deposited billet and subsequent volumetric stamping, which are carried out in one stamp, with preliminary pre-settlement carried out on a flat a striker having a diameter of 350 mm, until the diameter of the upsetting workpiece reaches the specified value of the diameter of the planar striker, which before flashing is placed in the central part of the brook w tampa, and after flashing is removed from the stamp, and incomplete open flashing of the deposited workpiece is carried out with a removable conical flashing with an installation pad having a diameter of 270 mm.

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