JP2010260098A - Method of forging long axis component with flange - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoch-making method of forging a long axis component with a flange, a method that brings remarkable efficiency and cost reduction in manufacturing an axle shaft for a vehicle. <P>SOLUTION: A required forging place of a stock 1 for a metallic shaft is locally heated preliminarily in a high frequency furnace at or above a transformation point. Then, the locally-heated required forging place is formed into the shape of a flange of an axle shaft for a vehicle by means of a dynamic pressure screw press or a static pressure screw press 3 as a vertical upsetter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a method for forging a long shaft part with a flange, and in particular, a dynamic pressure screw press or a static pressure screw which is a vertical upsetter without using a mechanical horizontal upsetter using a conventional split mold in a direction perpendicular to the axis. This is a forging method in which a forging point that has been locally heated in a high-frequency furnace by a press in advance to the transformation point is formed into a flange shape, which has been unavoidable in the past. The transfer of material by using a dynamic or static screw press, a vertical upsetter that provides a clean product and is much cheaper than conventional very large and expensive mechanical horizontal upsetters No equipment is required, and the cost of the equipment can be reduced, the mold does not need to be split in the direction perpendicular to the axis, the mold cost is low, no mold clamping device is required, setup time is short, and mechanical equipment It becomes much cheaper, especially the extremely efficient in the production of the axle shaft for the vehicle, to a forging method for breakthrough flanged long axis components that can result in cost reduction.

Conventionally, as an example of a flanged long shaft part, an axle shaft for a vehicle, which is a high load-resistant long shaft part and a safety part requiring extremely high strength, toughness and impact resistance, has been manufactured by hot forging. In this forging method, for example, as shown in Patent Document 2, in the forging process of the flange portion of the axle shaft for a vehicle, the raw material is in the state of a simple round bar that has not been processed. In the order of the third step and the fourth step, forging of a preliminary shape (preform) is performed so as to gradually approach the shape of the flange portion, and the flange flange in the order of the fifth step and the sixth step which are finishing steps. However, this forging process uses a split die that is split in two in the direction perpendicular to the axis of the material, and all the press equipment is a very large and expensive mechanical horizontal type. Jitter is used, the movement of the material had been processed using the mobile device (transfer).

In such a conventional forging method of a long shaft part with flange, it is inevitable that vertical bars appear in the axial direction on the finished axle shaft due to the parting line of the mold. There is a drawback that a finishing process for removing the vertical stripes is required.
In addition, since the material is as long as 1 m or more, the material transfer device (transfer) is complicated and expensive, requires a mold clamping device, requires high mold costs, takes a long setup time, and costs high for machinery and maintenance. There were many drawbacks.

Patent Document 1 Japanese Patent Laid-Open No. 5-277616
Patent Document 2 JP-A-5-277617
Patent Document 3 JP2009-6338

The applicant and inventor of the present application do not know the non-patent literature, so the description is omitted.

The present invention has been made in order to eliminate the above-described drawbacks of the prior art, and the object of the present invention is to locally heat a forging point of a metal shaft material in advance in a high-frequency furnace above the transformation point. In addition, by forming a forging point that is locally heated by a hydrodynamic screw press or a hydrostatic screw press, which is a vertical upsetter, into a flange shape, there is no need to split the material in the direction perpendicular to the axis, which was previously inevitable. This also prevents the vertical streak caused by the dividing line in the axial direction during the forging process from appearing at all in the finished product of the flanged long shaft part, and for removing the vertical streak This is to eliminate the finishing process and reduce the cost accordingly.

Another object of the present invention is that the above-described configuration eliminates the need for a material moving device, thereby reducing the cost of the device, and the die does not need to be split in the direction perpendicular to the axis. This makes it possible to shorten the setup time and make the machine device much cheaper than the conventional one (about one-half of the conventional horizontal upsetter), especially for the manufacture of axle shafts for vehicles. It is to improve efficiency and reduce costs (30% lower than conventional manufacturing costs).

Another object is to locally heat a forging point of a metal shaft material in advance at a transformation point or higher in a high-frequency furnace, and to set the forging point locally heated by a dynamic pressure screw press that is a vertical upsetter. By forming into a preliminary shape before completion by forging process of 3 to 3 steps, and then forming into a flange shape with a dynamic pressure press or hydrostatic screw press as an upsetter, a flange portion having a considerably large diameter from a small diameter material This makes it possible to carry out the forging process up to a reasonable amount, and in particular, dramatically improves the manufacturing efficiency of axle shafts for vehicles, and significantly reduces the cost of forging processes (compared to conventional manufacturing costs). 30% reduction). In particular, by forming the flange shape with a hydrostatic screw press, the strength of the frame of the device can be smaller than when using a hydrodynamic screw press, and this further reduces the cost of the press device. That is.

Another object is to eliminate most of the disadvantages of the horizontal upsetter system by using a vertical dynamic pressure screw press and a hydrostatic screw press driven by a servo motor, thereby reducing the maintenance cost of the press. It is almost unnecessary, and the manufacturing cost of the flanged long shaft part is greatly reduced (30% lower than the conventional manufacturing cost).

Another object is to use a hydrostatic motor-driven gear-type hydrostatic screw press driven by a servo motor as the drive source. It is intended to facilitate the control of the torque of the screw, and to make it possible to forge the long shaft part with flange more easily and efficiently.

In short, the method of the present invention (Claim 1) is that a forging portion of a metal shaft material is locally heated in advance at a transformation point or more in a high frequency furnace, and a dynamic pressure screw press or a static pressure screw press which is a vertical upsetter. The forged portion that is locally heated is formed into a flange shape.

In the method of the present invention (Claim 2), a forging point of a metal shaft material is locally heated in advance at a transformation point or higher in a high-frequency furnace, and is locally heated by a dynamic pressure screw press which is a vertical upsetter. The forging points required are formed into a preliminary shape before completion by a forging process of 2 to 3 steps, and then formed into a flange shape by a dynamic pressure screw press or a static pressure screw press which is an upsetter. is there.

The method of the present invention (Claim 3) is characterized in that the dynamic pressure screw press and the static pressure screw press are driven by a servo motor.

Further, the method of the present invention (Claim 4) is a gear type hydrostatic screw press driven by a hydraulic motor using a servo motor as a drive source.

The present invention (Claim 5) is characterized in that the long shaft part with flange is an axle shaft for a vehicle.

In the present invention, as described above, the forged portion of the metal shaft material is locally heated in advance at the transformation point or higher in a high-frequency furnace, and is locally applied by a dynamic pressure screw press or a static pressure screw press that is a vertical upsetter. Since the heated forging points are molded into a flange shape, it is possible to eliminate the need for splitting in the direction perpendicular to the axis of the material, which has been inevitable in the past, and as a result, there is no dividing line in the axial direction during forging. It is possible to prevent the vertical stripes of the cause from appearing in the finished product of the flanged long shaft part, and there is an effect that a finishing process for removing the vertical stripes is not required, thereby reducing the cost accordingly. There is an effect that can.

In addition, the above configuration eliminates the need for a material moving device, which can reduce the cost of the device, and the mold does not need to be broken in the direction perpendicular to the axis, so the cost of the mold is reduced, and no mold clamping device is required. The setup time is short and the machine is much cheaper than the conventional one (about one-half of the conventional horizontal upsetter), so the efficiency and cost are particularly high for the manufacture of axle shafts for vehicles. There is an effect that can bring down (30% reduction compared to the conventional manufacturing cost).

In addition, the forging points of the metal shaft material are locally heated in advance at the transformation point or higher in a high-frequency furnace, and the forging points locally heated by a dynamic pressure screw press, which is a vertical upsetter, are forged in two to three steps. By forming into a preliminary shape prior to completion by processing, and then forming into a flange shape using an upsetter, such as a hydrodynamic screw press or a hydrostatic screw press, forging from a small diameter material to a flange portion with a considerably large diameter is performed. This can be carried out without difficulty, and as a result, the manufacturing efficiency of axle shafts for vehicles can be dramatically improved, and the cost of forging can be greatly reduced (30% reduction compared to conventional manufacturing costs). There is. In particular, by forming the flange shape with a hydrostatic screw press, the frame strength of the device can be smaller than when using a hydrodynamic screw press. As a result, the cost of the press device can be further reduced. is there.

In addition, since the vertical dynamic pressure press and the static pressure screw press are driven by a servo motor, the disadvantages of the horizontal upsetter method can be almost eliminated. There is an effect that the manufacturing cost of the attached long shaft part can be greatly reduced (30% lower than the conventional manufacturing cost).

In addition, since the hydrostatic screw press uses a hydraulic motor-driven gear-type hydrostatic screw press that uses a servo motor as the drive source, it is easier to control the torque of the screw of the hydrostatic screw press than the electric motor drive. In addition, there is an effect that the long shaft part with flange can be forged easily and efficiently.

The drawings relate to an embodiment of the present invention, and FIG. 1 is a perspective view of the material. It is a perspective view of the raw material in which the preliminary process of the 1st step was performed. It is a perspective view of the raw material to which the preliminary process of the 2nd step was given. It is a perspective view of the axle shaft for vehicles which is an example of the long shaft part with a flange which finished finishing. It is a front view of what is shown in FIG. It is a partial longitudinal cross-section front view of what is shown in FIG. It is a partial longitudinal cross-section front view of what is shown in FIG. It is a partial longitudinal cross-section front view of what is shown in FIG. It is a partial longitudinal cross-sectional front view of the upper mold | type of a metal mold | die, and a lower mold | type. It is a partial longitudinal cross-section front view which shows the state which the raw material to which the preliminary process was given to the lower mold | type is attached, and the upper mold | type starts a fall. It is a partial longitudinal cross-section front view which shows the state by which an upper mold | type descend | falls and finishing forge processing is started. It is a partial longitudinal cross-section front view which shows the state in the middle of finish forging. It is a partial longitudinal cross-section front view which shows the state which the finish forge process was completed. It is a partial longitudinal cross-sectional front view of a vertical hydrostatic screw press showing a state in which a material subjected to preliminary processing is attached to a lower die and the upper die starts to descend. It is a partial longitudinal cross-section front view of the vertical hydrostatic screw press which shows the state in the middle of finish forging. It is a partial longitudinal cross-section front view of the vertical hydrostatic screw press which shows the state which the finish forging process was completed.

DESCRIPTION OF SYMBOLS 1 Metal shaft raw material 1a 1st preliminary shape 1b 2nd preliminary shape 1c Flange shape 2 Forging required part 3 Static pressure screw press 4 Axle shaft 4a axle part 4c axle part for vehicles which is an example of long axis parts with a flange Flange 5 Servo motor 5a Rotating shaft 6 Hydraulic pump 6a Rotating shaft 7 Coupling 8 Hydraulic motor 8a Rotating shaft 9 Hydraulic piping 10 Pinion 11 Flywheel 11a Gear 12 Lead screw 13 Slide 14 Guide screw 15 Slide guide 16 Upper mold 17 Mold 18 Lower mold 19 Base A arrow B arrow C arrow D arrow E arrow F arrow G arrow H arrow

Hereinafter, the present invention will be described based on embodiments shown in the drawings. As shown in FIGS. 1 to 8, the forging method for a flanged long shaft part according to the present invention is such that a forged portion 2 of a metal shaft material 1 is locally heated in advance in a high-frequency furnace to the transformation point or more. (FIGS. 1 and 5), a forging portion 2 that is locally heated by a dynamic pressure screw press (not shown), which is a vertical upsetter, is subjected to a forging process of 2 to 3 steps, and a first preliminary before completion Are sequentially formed into a target shape 1a (FIGS. 2 and 6) and a second preliminary shape 1b (FIGS. 3 and 7), and then a dynamic pressure screw press (not shown) or a static pressure which is a vertical upsetter Formed into a flange shape 1c by a screw press 3 (FIGS. 14 to 16), and a flange portion 4c is formed at one end of a shaft portion 4a as shown in FIGS. Axle shaft for vehicle as an example of long shaft part with flange It is a method of forging to.

The metal shaft material 1 is an important part of safety in the vehicle because the axle shaft 4 for the vehicle is used for the driving wheel of the vehicle, and the direction is large (forward and reverse) when the vehicle is running. In addition to the torque, bending load and impact load are applied, and various reaction forces from the wheel act on the flange 4c, which is a component that easily causes metal fatigue. Therefore, sufficient strength and particularly toughness A high-load-resistant metal having the following is used, and a round bar of structural rolled steel is mainly used.
As the dimensions of the metal shaft material 1 used in the present invention, those having a diameter of, for example, 40 mm to 120 mm and a length of 1 m or more are used, and the diameter of the flange portion 4c at the product stage as the axle shaft 4 is, for example, 140 mm. To 400 mm, the thickness of the flange 4 c is, for example, 10 mm to 30 mm, and the total length is, for example, 500 mm to 1 m or more.
In addition, the metal shaft material 1 is not limited to steel in the case of long shaft parts with flanges when there is a demand for lighter than strength, resistance to rust, etc. Brass, copper, aluminum In addition, non-ferrous metals such as titanium alloys may be used.

The high frequency furnace is well known and will not be described. However, according to the high frequency furnace, the forged portion 2 of the metal shaft raw material 1 is heated to an arbitrary temperature within an arbitrary range in a short time by high frequency induction heating. Since the transformation point of steel is 721 ° C., the forging point 2 of the metal shaft material 1 is heated to 721 ° C. or higher, that is, the hot forging temperature of the steel, and becomes a red hot state and forged. Will be.

For the screw press that is a vertical upsetter, in the forging process for the preform as the rough ground finish in the first 2 to 3 steps, the static pressure screw press is not used, but the lower die ascending type that is the vertical upsetter In the finishing process of the flange portion 4c, a hydrodynamic screw press (not shown) can be used in addition to the hydrostatic screw press 3, but a detailed description of the hydrodynamic screw press is as follows. Omitted.

The hydrostatic screw press 3 that is a vertical upsetter may be a gear type (not shown) that is directly driven by a servo motor, and the servo motor 5 shown in FIGS. A hydrostatic screw press 3 driven by a hydraulic motor may be used.
In this embodiment, the servo motor 5 is used as a drive source, and a gear type hydrostatic screw press 3 driven by a hydraulic motor 8 driven by pressure oil supplied from a hydraulic pump 6 is used. The rotation of the servo motor 5 in the direction of arrow A or B is transmitted to the rotary shaft 6a of the hydraulic pump 6 by the coupling 7 fixed to the rotary shaft 5a, and the pressure oil is supplied to the hydraulic motor 8 by the hydraulic pipe 9. It is like that.
Note that the hydraulic motor 8 may be replaced with the servo motor 5 so that the pinion 10 is directly rotated by the servo motor 5 and the gear 11 is rotated via the pinion. In this case, the coupling 7, the hydraulic pump 6, the hydraulic pipe 9, the hydraulic motor 8, and the like can be omitted, and the equipment cost can be further reduced as compared with the illustrated embodiment.

14 to 16, when the hydraulic motor 8 rotates as indicated by an arrow C or D, the pinion 10 fixed to the rotating shaft 8a rotates in the same direction, and the gear 11a on the outer periphery of the flywheel 11 meshed with the pinion 10 is rotated. Since the rotation of the flywheel 11 is transmitted to the lead screw 12 fixed to the flywheel, and the lead screw 12a meshes with the guide screw 14 integrated with the slide 13, When the flywheel 11 rotates clockwise as seen from the arrow F as shown by the arrow F, the slide 13 is guided and lifted by the slide guide as shown by the arrow G, and the flywheel 11 is counterclockwise as seen from the top as shown by the arrow E. When it rotates, it descends as shown by arrow H.

Since the upper mold 16 is fixed to the slide 13 and the lower mold 18 is fixed to the base 19, the metal shaft material 1 attached to the lower mold 18 is separated from the upper mold 16 by the downward movement of the slide 13. It is sandwiched between the lower mold 18 and forged.
Further, when the hydraulic motor 8 rotates in the reverse direction and the flywheel 11 rotates as indicated by the arrow F, the upper die 16 rises as indicated by the arrow G via the slide 13 and is detached from the lower die 18 so that the forging process is completed. It has become.

As shown in FIG. 9, the die 17 is a vertical dynamic pressure screw press or a static pressure screw press 3, so it is not necessary to divide the metal shaft raw material 1 in the direction perpendicular to the axis. The upper die 16 may be simply divided into the upper die 16 and the lower die 18, and the upper die 16 is formed in accordance with the shape of the upper half of the flange portion 4c, and the lower die 18 is formed at the lower half of the thickness of the flange portion 4c. It is formed according to the shape. And the forging process is made | formed by combining both, The flange part 4c is formed in the raw material 1 for metal shafts.

The present invention is configured as described above, and its operation will be described below. In the metal shaft material 1, first, the forging point 2 is partially heated to a steel transformation point, that is, 721 ° C. or higher by a high-frequency furnace, becomes red hot, and a vertical dynamic pressure screw press (not shown) rises. A forged shape that is attached to the lower die and hot forged between the upper die and the forged portion 2 slightly swells as shown in FIGS. 2 and 6 from the simple round bar state of FIGS. The first preliminary shape 1a is preformed.

Next, the forging point 2 is attached to the lower die next to the vertical dynamic pressure screw press in the same manner as described above, and the second hot forging process is performed, thereby forming a flange shape as shown in FIGS. It is preformed to a near dumpling second preliminary shape 1b.
In the illustrated embodiment, the preform has been described as two steps, but this may be three steps.

Finally, the forging point 2 of the metal shaft raw material 1 is again made into a vertical hydrodynamic screw press (not shown) or, as shown in FIGS. 10 and 14, for finishing the hydrostatic screw press 3. It is attached to the lower mold 18, the hydraulic motor 8 is rotated through the servo motor 5 and the hydraulic pump 6, and the flywheel 11 is rotated through the gear 11 a by the pinion 10 as shown by the arrow E, and the upper mold 16 is moved to the arrow H As shown in FIGS. 13, 16 and 16, the forged portion 2 having a flange shape close to the flange shape is hot-forged between the lower die 18 and the intermediate forging process shown in FIGS. When the upper die is lowered to a completed state as shown in FIG. 2, a flange portion 4c as a finished product is formed on the metal shaft raw material 1, and the hydraulic motor 8 rotates in the direction of the arrow D to fly. Wheel 11 is also an arrow Slide 13 and the upper mold 16 and the reverse rotation direction is increased as indicated by the arrow G, the axle shaft 4 for vehicle shown in FIG. 4 and FIG. 8 is completed.
In this way, in the final finishing forging process, a vertical hydrodynamic screw press or a hydrostatic screw press 3 is used. In particular, in the hydrostatic screw press 3, the lowering speed of the upper die is very smooth, and Since the hydraulic motor 8 is used, it is easy to control the speed, the processing can be performed under ideal forging conditions, and the axle shaft 4 for a vehicle having a large flange portion 4c with fewer forging processes than in the past. It is possible to perform the forging process without difficulty.
Further, according to the static pressure screw press 3, the frame strength is smaller than that of the dynamic pressure screw press, and the static pressure screw press 3 is advantageous also in this respect. However, if the strength of the frame is increased, the hydrodynamic screw press can sufficiently cope with the finish forming of the flange portion 4c.

Claims (5)

  The forging point of the metal shaft material is locally heated above the transformation point in a high-frequency furnace in advance, and the local forging point that is locally heated by a hydrostatic screw press or a static pressure screw press, which is a vertical upsetter, is flanged. A forging method for a flanged long shaft part, characterized by forming into a shape.   The forging part of the metal shaft material is locally heated in advance at the transformation point or higher in a high-frequency furnace, and the locally heated forging part is forged in two to three steps by a dynamic pressure screw press which is a vertical upsetter. A forging method for a long-shaft component with a flange, characterized by forming into a preliminary shape before completion by processing, and thereafter forming into a flange shape by a dynamic screw press or a hydrostatic screw press as an upsetter.   3. The forging method for a flanged long shaft part according to claim 1, wherein the dynamic pressure screw press and the static pressure screw press are driven by a servo motor. 3. The forging method for a flanged long shaft part according to claim 1, wherein the hydrostatic screw press is a hydraulic motor driven gear hydrostatic screw press using a servo motor as a drive source. . 5. The forging method of a flanged long shaft part according to claim 1, wherein the flanged long shaft part is an axle shaft for a vehicle.

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