JP2011073033A - Forging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forging method achieving a simplified die. <P>SOLUTION: In the forging method, a die 2 having a through hole 21 with one side part thereof being constituted as a workpiece installation hole 31 and the other side part being constituted as a workpiece forming die hole 41, a punch 1 to be driven into the through hole 21 from one end side thereof, and a workpiece draw-resisting means for allowing the workpiece to stay in the workpiece forming die hole 41 are prepared. While a preceding workpiece W2 is stayed in the workpiece forming hole 41, a succeeding workpiece W is installed in the workpiece installation hole 31. By driving an upper die 1 into the through hole 21, the succeeding workpiece W projects the preceding workpiece W2 from the other end side of the through hole 21, and the succeeding workpiece W is press-fitted in the workpiece forming die hole 41 and formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a forging method in which a workpiece is forged using a mold and related technology.

  Forging devices for die forging, for example, a forging material (work) is placed in a molding hole provided in a lower die (die), and an upper die (punch) is driven into the workpiece in the molding hole. Thus, the forging material is pressure-molded to obtain a forged molded product.

  In such a forging device, a knockout pin is provided at the bottom of the molding hole in the lower mold so as to be able to pop out upward. After the mold is opened, the knockout pin is protruded, and the lower mold uses the knockout pin. The forged molded product inside is pushed up and discharged.

JP 2002-66686 A JP 2003-326333 A

  However, in the above-mentioned conventional forging apparatus, since the knockout pin for protruding the forged molded product is provided in the lower die, a knockout pin, a drive unit for driving the pin, and the like are necessary. The mold becomes complicated, large, and heavy.

  Further, in the conventional forging apparatus, when performing a process for taking out a forged molded product (work discharge process), it is not possible to perform an upper mold driving process (work molding process). In other words, it is necessary to perform the work molding process and the work discharge process separately from each other, and there is a problem that the cycle time becomes long and the productivity is lowered.

  In particular, in a forging device that manufactures a forged molded product with helical gear teeth formed on the outer peripheral surface, such as a helical gear, the forged molded product can be made smooth simply by pushing up the forged product in the lower mold. It cannot be taken out. For this reason, for example, as shown in Patent Documents 1 and 2, a complicated mechanism that pushes up the forged molded product in the lower mold while rotating the forged molded product relative to the lower mold around the vertical axis. Therefore, there is a possibility that the mold becomes more complicated, larger and heavier.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a forging method and related technology capable of achieving simplification, miniaturization, weight reduction, and productivity improvement of a mold. And

  In order to solve the above problems, the present invention comprises the following means.

[1] A through hole having both ends opened, and one side portion of the through hole is configured as a workpiece installation hole in which a workpiece is installed, and the other side portion is a workpiece molding hole for molding the workpiece. A configured die,
With the workpiece installed in the workpiece installation hole, a punch that press-fits the workpiece while plastically flowing into the workpiece molding hole by being driven into the through hole from one end side thereof,
A workpiece pull-out resistance means is provided, which applies a workpiece pull-out resistance force that becomes a resistance when the workpiece in the workpiece molding hole moves to the other end side, and stops the workpiece in the workpiece molding hole. ,
In a state where the preceding workpiece is stopped in the workpiece forming hole, the succeeding workpiece is set in the workpiece setting hole, and the punch is driven into the through hole. A forging method characterized by projecting from the other end side of the through hole and press-fitting a subsequent workpiece into the workpiece molding hole.

  [2] The forging method according to item 1, wherein the other end surface of the preceding workpiece is used as a constraining surface when the subsequent workpiece is formed.

  [3] When the punch is driven into the through-hole, the preceding workpiece is projected against the workpiece pull-out resistance force, so that the preceding workpiece is against the subsequent workpiece against the workpiece pull-out resistance. 3. The forging method according to item 1 or 2, wherein the forging method functions as a back pressure applying member that uses force as a back pressure.

  [4] The forging method according to any one of items 1 to 3, wherein a frictional resistance force between the preceding workpiece and the inner peripheral surface of the workpiece forming hole is caused to function as the workpiece withdrawal resistance force.

  [5] The forging method according to any one of items 1 to 4, wherein the die has a workpiece forming groove formed in a spiral or spiral shape on the inner peripheral surface of the workpiece forming hole. .

  [6] The forging method according to any one of items 1 to 5, wherein the die is provided with a drawing portion for reducing the diameter of the workpiece at least a part of the workpiece molding hole.

  [7] Any one of [1] to [6], wherein the die in which the length in the axial direction of the workpiece forming hole is shorter than the length in the axial direction of the workpiece after forming is used as the die. Forging method.

  [8] The forging method according to any one of items 1 to 7, wherein a die having a portion having a high surface roughness is provided on the inner peripheral surface of the workpiece forming hole.

  [9] The forging method according to any one of items 1 to 8, wherein a workpiece made of aluminum or an aluminum alloy is used.

  [10] The forging method according to any one of the above items 1 to 9, wherein a forged molded product in which the ridge portion is formed in a spiral shape or a spiral shape on the outer peripheral surface is manufactured.

  [11] The forging method according to any one of items 1 to 10, wherein a rotor part of a supercharger for an automobile is manufactured.

  [12] The forging according to any one of items 1 to 3, wherein the workpiece is reduced in diameter in the workpiece forming hole, and the deformation force at the time of reducing the diameter is made to function as the workpiece withdrawal resistance force. Method.

[13] A through hole having both ends opened, and one side portion of the through hole is configured as a workpiece installation hole in which a workpiece is installed, and the other side portion is a workpiece molding hole for molding the workpiece. A configured die,
With the workpiece installed in the workpiece installation hole, a punch that is press-fitted while plastically flowing the workpiece into the workpiece molding hole by being driven into the through hole from one end side thereof,
A workpiece withdrawal resistance means for applying a workpiece withdrawal resistance force that becomes a resistance when the workpiece in the workpiece molding hole moves to the other end side, and for stopping the workpiece in the workpiece molding hole,
In a state where the preceding workpiece is stopped in the workpiece forming hole, the succeeding workpiece is set in the workpiece setting hole, and the punch is driven into the through hole. A forging die characterized by protruding from the other end side of the through-hole and press-fitting a subsequent workpiece into the workpiece molding hole.

  [14] A forging device comprising the forging die described in the above item 13.

  According to the forging method of the invention [1], since a work discharging mechanism such as a knockout pin for discharging the forged molded product in the work forming hole can be omitted, the die can be simplified, downsized and reduced in weight accordingly. Can be achieved. Furthermore, since the molding of the workpiece and the discharging of the workpiece can be performed simultaneously, the cycle time can be shortened and the productivity can be improved.

  According to the forging method of the invention [2], closed forging can be performed.

  According to the forging method of the invention [3], it is possible to produce a forged product having a high dimensional accuracy without any lack of thickness.

  According to the forging methods of the inventions [4] to [8], it is possible to produce a forged product of even higher quality.

  According to the forging method of the invention [9], a forged product made of aluminum can be produced.

  According to the forging method of the invention [10] [11], a predetermined forged product can be manufactured.

  According to the forging method of the invention [12], it is possible to produce a forged product with high dimensional accuracy free from a lack of thickness.

  According to the invention [13], it is possible to provide a forging die having the same function and effect as described above.

  According to the invention [14], it is possible to provide a forging device having the same function and effect as described above.

FIG. 1 is a perspective view showing a die of a forging device according to a first embodiment of the present invention, with a half thereof cut away. FIG. 2A is a cross-sectional view showing the lower mold of the first embodiment in a state where the first workpiece is installed. FIG. 2B is a cross-sectional view showing the lower mold of the first embodiment in a state where the first workpiece is molded. FIG. 3A is a cross-sectional view showing a state immediately before molding the second and subsequent workpieces in the forging device of the first embodiment. FIG. 3B is a cross-sectional view showing a state in the middle of molding the second and subsequent workpieces in the forging device of the first embodiment. FIG. 3C is a cross-sectional view showing a state immediately after molding the second and subsequent workpieces in the forging device according to the first embodiment. FIG. 4 is a perspective view showing a forged product processed by the forging device of the first embodiment. FIG. 5 is a perspective view showing a forging material processed by the forging device of the first embodiment. FIG. 6 is a perspective view showing a die of a forging device according to a second embodiment of the present invention, with half of the die cut away. FIG. 7A is a cross-sectional view showing a lower die of the forging device according to the second embodiment in a state where a first workpiece is installed. FIG. 7B is a cross-sectional view showing the lower mold of the second embodiment in a state where the first workpiece is molded. FIG. 8A is a cross-sectional view showing a state immediately before molding the second and subsequent workpieces in the forging device according to the second embodiment. FIG. 8B is a cross-sectional view showing a state in the middle of molding the second and subsequent workpieces in the forging device according to the second embodiment. FIG. 8C is a cross-sectional view showing a state immediately after molding the second and subsequent workpieces in the forging device of the second embodiment. FIG. 9 is a perspective view showing a mold part of a forging device according to a third embodiment of the present invention, with a half thereof cut away. FIG. 10 is a perspective view showing a forging material processed by the forging device of the third embodiment. FIG. 11 is a perspective view showing a die part of a forging device according to a fourth embodiment of the present invention, with a half thereof cut away. FIG. 12 is a perspective view showing a forged product processed by the forging device of the fourth embodiment. FIG. 13 is a perspective view showing a forging material processed by the forging device of the fourth embodiment. FIG. 14 is a perspective view showing a die part of a forging device according to a fifth embodiment of the present invention, with a half thereof cut away.

<First Embodiment>
First, a forged product W2 manufactured based on the first embodiment of the present invention will be described. As shown in FIG. 4, the forged molded product W <b> 2 is composed of rotor parts in a supercharger such as an automobile. This rotor part employs a three-leaf type twist lobe, and the three lobes W3 provided on the outer periphery are moved from one end side (upper end side) to the other end side (lower end side) in the axial direction. On the other hand, it has a shape twisted like a spiral.

  Further, as the forging material W1 for processing the forged molded product W2, a cast part, an extruded product, a forged part, an upset part, a machined part, etc. can be used. As shown in FIG. In the embodiment, an extruded product is used. This forging material W1 is a twist-free shape in which the protrusions corresponding to the lobes W3 of the forged molded product W2 are formed on the outer periphery in parallel to the axial direction, and is formed into a helical shape by forging according to this embodiment. It is formed into a twisted shape.

  The forging material W1 is made of aluminum or an aluminum alloy. For example, an Al—Si—Mg alloy (6000 series alloy), an Al—Si alloy (4000 series alloy), or the like is preferably used. Among them, the 6000 series alloy is suitable for the forging process of the present embodiment because it is easily stretched and has good fluidity.

  Here, as in the present embodiment, when an extruded product is used as the forging material W1, the cast bar obtained by continuous casting is subjected to heat treatment and peeling treatment, and then extrusion is performed to perform extrusion. A forged material W1 is obtained by producing a bar and cutting the extruded bar.

  Furthermore, when using a forging part and an upsetting part as the forging material W1, the forging material W1 can be obtained by cutting the cast bar instead of extrusion forming and then forging and upsetting.

  Further, as in the third and fifth embodiments to be described later, when the forging material W1 is manufactured by a cast part that is not extruded, a cast bar obtained by continuous casting is subjected to heat treatment, peeling treatment, ultrasonic wave. After the inspection, the forging material W1 is obtained by cutting.

  As will be described in the third and fifth embodiments described later, the horizontal cross-sectional shape of the forged material W1 does not need to be similar to the horizontal cross-sectional shape of the forged product W2, and is other shapes such as a circle. You may make it form.

  In the present embodiment, when the workpiece W is referred to, the workpiece W includes both the forging material W1 and the forged molded product W2.

  FIG. 1 is a half-cut perspective view showing a mold of a forging device according to a first embodiment of the present invention. As shown in FIG. 1, the forging device of the present embodiment includes an upper mold 1 disposed above and a lower mold 2 disposed corresponding to the lower side of the upper mold 1.

  In the present embodiment, the upper side corresponds to one end side, and the lower side corresponds to the other end side (the same applies to the following second to fifth embodiments).

  The lower die 2 constitutes a die, and is divided into a workpiece setting die 3 arranged on the upper side and a workpiece molding die 4 arranged on the lower side.

  A workpiece installation hole 31 that is continuous from the upper end (one end) to the lower end (the other end) is formed in the workpiece installation mold 3 along the axial direction (vertical direction). The workpiece installation hole 31 is open at both upper and lower ends, and has a horizontal cross-sectional shape corresponding to the horizontal cross-sectional shape of the forging material W1.

  Further, the workpiece installation hole 31 has a length in the axial direction longer than the axial length of the forging material W1.

  In the workpiece molding die 4, a workpiece molding hole 41 that is continuous from the upper end (one end) to the lower end (the other end) is arranged along the axial direction (vertical direction) corresponding to the workpiece installation hole 31. Yes. The workpiece molding hole 41 is open at both upper and lower ends, and the upper end opening communicates with the lower end opening of the workpiece installation hole 31.

  Furthermore, the workpiece forming hole 41 has an inner peripheral surface shape corresponding to the outer peripheral surface shape of the forged molded product W2. That is, on the inner peripheral surface of the workpiece molding hole 41, three workpiece molding groove portions 42 are formed along the spiral winding shape, corresponding to the three lobes W3 in the forged molded product W2.

  It is to be noted that the interval between the workpiece forming groove portions 42, in other words, the thickness of the shape blade is preferably set to a thickness that can withstand the load when the upper mold 1 is driven, specifically, 3 mm or more.

  Further, the workpiece forming hole 41 has a length in the axial direction set to be substantially the same as the length in the axial direction of the forged molded product W2 after forming.

  Further, the horizontal cross-sectional area of the forging material W <b> 1 is formed equal to or smaller than the horizontal cross-sectional area of the workpiece forming hole 41.

  The upper end opening of the workpiece installation hole 31 in the lower mold 2 is configured as a workpiece insertion port 35, and the forging material W <b> 1 is introduced into the workpiece installation hole 31 through the workpiece insertion port 35. ing.

  In the workpiece installation hole 31, the forging material W <b> 1 can be installed. In this state, as described later, when the upper mold 1 is driven into the workpiece installation hole 31, the forging material W <b> 1 becomes plastic. The forging material W1 is pressed into the workpiece molding hole 41 while flowing, whereby the forging material W1 is molded into a shape corresponding to the inner peripheral surface shape of the workpiece molding hole 41, that is, a shape corresponding to the forged molded product W2. ing.

  The lower end opening of the workpiece molding hole 41 in the lower mold 2 is configured as a workpiece discharge port 45, and a forged molded product W <b> 2 in the workpiece molding hole 41 passes through the workpiece discharge port 45 as will be described later. It is designed to be discharged downward.

  Here, in the present embodiment, the workpiece installation hole 31 and the workpiece molding hole 41 are configured as a through hole 21 that penetrates the lower mold 2 in the vertical direction (axial direction) and is open at both upper and lower ends.

  In this embodiment, as will be described in detail later, when the forged molded product W2 in the workpiece molding hole 41 is discharged from the workpiece discharge port 45, the outer peripheral surface of the forged molded product W2 and the workpiece molding hole 41 A frictional resistance is generated between the inner peripheral surface and the frictional resistance, which functions as a workpiece pullout resistance that becomes a resistance when the forged molded product W2 in the workpiece molding hole 41 moves downward. To do. Therefore, the inner peripheral surface of the workpiece molding hole 41 is configured as a workpiece removal resistance means.

  Furthermore, in the present embodiment, since a plurality of workpiece molding groove portions 42 are formed in a spiral shape on the inner peripheral surface of the workpiece molding hole 41, the forged molded product W2 in the workpiece molding hole 41 is directed downward. When discharged, the forged molded product W2 moves downward along the workpiece forming groove 42 while twisting and rotating. Therefore, it is possible to sufficiently secure the frictional resistance force (workpiece pull-out resistance force) between the inner peripheral surface of the workpiece molding hole 41 and the forged molded product W2.

  On the other hand, the upper die 1 constitutes a punch, and the horizontal cross-sectional shape is formed corresponding to the horizontal cross-sectional shape of the forging material W1, and the upper end opening is opened in the work installation hole 31 of the lower die 2. It can be inserted from the part.

  Further, the upper die 1 is configured to be movable up and down by a driving means (not shown), and when it is lowered from the raised position, it is driven into the workpiece installation hole 31 of the lower die 2. Yes.

  In the forging device of the first embodiment having the above-described mold, the forging process for the first forging material W1 is a preliminary process (preliminary processing), and the forging material W1 for the second and subsequent sheets. Forging is regular processing (main processing) by the main forging device.

  First, in the forging device of the present embodiment, in the initial state, the workpiece W is not disposed in any of the workpiece installation hole 31 and the workpiece molding hole 41 in the lower mold 2, and the upper mold 1 is raised. Placed in position.

  From this initial state, as shown in FIG. 2A, the first forging material W1 is introduced from the workpiece insertion port 35 of the lower mold 2 and disposed in the workpiece installation hole 31. In this case, since the workpiece molding hole 41 disposed below the workpiece installation hole 31 is formed in a twisted shape with respect to the workpiece installation hole 31, the lower end of the forging material W1 is the upper end of the workpiece molding hole 41. By being locked to the edge, it is arranged in a state of staying in the workpiece installation hole 31.

  After the forging material W1 is introduced, the upper die 1 is lowered and the upper die 1 is driven into the forging material W1 in the workpiece installation hole 31 (die closing process). As a result, as shown in FIG. 2B, the forging material W1 is press-fitted so as to be screwed into the workpiece molding hole 41 while plastic flowing, and is forged so as to correspond to the inner peripheral surface shape of the workpiece molding hole 41. The twisted forged product W2 is formed.

  When the first forging material W1 is press-fitted into the workpiece molding hole 41, the entire area inside the workpiece molding hole 41 becomes an unfilled molding space portion, and the lower side is opened as a workpiece discharge port 45. ing. Therefore, the forging process for the first forging material W1 is a semi-sealed or open forging process in which one end side (lower side) is opened.

  As will be described in detail later, the forging process for the second and subsequent forging materials W1 is a hermetic (fully sealed) forging process.

  On the other hand, even after the upper die 1 is raised and the first forging process is completed, the forged molded product W2 in the workpiece molding hole 41 has a frictional resistance against the inner circumferential surface of the workpiece molding hole as described above. It is held in a state of being retained in the work molding hole 41 by (work removal resistance).

  As will be described later, this workpiece pull-out resistance acts as a back pressure during the forging process for the second and subsequent sheets, and the first (preceding) workpiece W becomes the second and subsequent (following) workpiece W. In contrast, it functions as a back pressure application member.

  When the first forging process (preliminary process) is completed, the forging process (main process) is sequentially performed on the second and subsequent forging materials W1.

  That is, with the first (preceding) workpiece (forged molded product W2) remaining in the workpiece molding hole 41, the second and subsequent (following) workpiece (forged material W1) is installed on the lower die 2 workpiece. It is thrown into the hole (31). At this time, the succeeding workpiece W is arranged in such a manner that it is placed on the upper end surface of the preceding workpiece W.

  In this state, as shown in FIG. 3A, the upper mold 1 is lowered and the upper mold 1 is driven into the subsequent work W in the work installation hole 31. As a result, as shown in FIG. 3B, the succeeding workpiece W is pressed into the workpiece molding hole 41 by plastic flow while protruding downward from the preceding workpiece W. Thus, as shown in FIG. 3C, the succeeding workpiece W is filled so as to be screwed into the workpiece molding hole 41, and the preceding workpiece W is discharged from the workpiece discharge port 45 while being twisted and rotated. It is cut off from and falls.

  As described above, in the forging device of the present embodiment, when the subsequent workpiece W is formed, the upper end surface (the other end surface) of the preceding workpiece W functions as a restraining surface with respect to the subsequent workpiece W. The entire peripheral surface of the workpiece W is restrained by the upper end surface of the preceding workpiece W, the inner peripheral surface of the through hole 21, and the lower end surface of the upper mold 1. That is, in the present embodiment, the second and subsequent forging materials W1 can be formed by hermetic forging.

  Here, when the succeeding workpiece W is press-fitted into the workpiece molding hole 41, the preceding workpiece W has a helically wound ridge (lobe) W <b> 3 having a helical winding shape of the workpiece molding hole 41. Since the workpiece forming groove 42 is accommodated in a conforming state, when the preceding workpiece W advances in the protruding direction (downward), the preceding workpiece W is twisted and rotated along the spirally wound groove portion 42. While progressing. For this reason, a large frictional resistance force (work pull-out resistance force) is generated between the outer peripheral surface of the preceding workpiece W and the outer peripheral surface of the workpiece molding hole 41. Therefore, the succeeding workpiece W is press-fitted into the workpiece molding hole 41 while pushing the preceding workpiece W against the workpiece ejection resistance force. In other words, the preceding work W functions as a back pressure application member that uses the above-described protruding resistance force as a back pressure with respect to the subsequent work W.

  In this way, the subsequent workpiece W is filled in the cavity while expanding the molding cavity (work molding hole 41) while receiving the back pressure, so that the subsequent workpiece W is directly filled in the space portion. There is nothing to do. For this reason, the subsequent workpiece W spreads evenly and smoothly in the direction orthogonal to the axial direction (driving direction), and is filled in the workpiece molding hole 41 without a gap. Therefore, it is possible to stably produce a forged molded product W2 free from defects such as a lack of thickness, and to reliably produce a high-quality forged product excellent in dimensional accuracy and the like.

  On the other hand, in the forging device of the present embodiment, the above operation is performed continuously. That is, in a state where the preceding workpiece W is stopped in the workpiece forming hole 41, the succeeding workpiece W is sequentially put into the workpiece setting hole 31, and the upper die 1 is driven, so that the preceding workpiece W is As the forged molded product W2, it is ejected to the succeeding workpiece W and sequentially discharged.

  As described above, according to the forging device of the present embodiment, the workpiece setting hole 31 is provided on the upper side of the through hole 21 in the lower mold 2, the workpiece molding hole 41 is provided on the lower side, and the preceding workpiece W is replaced with the workpiece molding hole 41. The upper mold 1 is driven into the subsequent workpiece W in the workpiece installation hole 31 in a state where the workpiece W is stopped, and the subsequent workpiece W is press-fitted into the workpiece molding hole 41 to form the workpiece. Since the workpiece W (forged molded product W2) is projected and discharged downward, there is no need for a workpiece discharge mechanism such as a knockout pin for discharging the forged molded product arranged in the lower mold, Therefore, the die can be simplified and reduced in size and weight, and the cost can be reduced.

  In addition, since the succeeding workpiece W is press-fitted into the workpiece molding hole 41 and at the same time the preceding workpiece W is ejected, the upper die 1 driving process (work molding process) and the workpiece discharging process are performed simultaneously in parallel. It can be carried out. For this reason, cycle time can be shortened, productivity can be improved, and cost can be further reduced.

  Further, the forging device of this embodiment performs hermetic forging for forming the succeeding workpiece W while constraining the entire peripheral surface of the succeeding workpiece W by the preceding workpiece W, the inner circumferential surface of the through hole 21 and the upper mold 1. Therefore, the forged molded product W2 with few burrs, surplus parts, and the like can be manufactured, the material yield can be improved, and the cost can be further reduced.

  In the forging device of the present embodiment, as described above, the preceding workpiece W functions as a back pressure application member, so that the workpiece W is filled in the workpiece forming hole 41 while receiving the back pressure. Therefore, it is possible to smoothly produce a forged molded product W2 free from defects such as a lack of thickness, and to produce a high-quality forged product excellent in dimensional accuracy and the like more reliably.

  Further, in the forging device of the present embodiment, the workpiece W is discharged from below the lower mold 2, so that the workpiece discharge direction matches the driving direction of the upper mold 1. For this reason, a high load is not required, and it is possible to produce using a small press mechanism without using a large press mechanism, further reducing the size and weight of the apparatus, and further reducing the cost. be able to.

  The forging process according to the present embodiment can be performed by either hot forging or cold forging. For example, when the size of the forged molded product W2 is small and a 6061 series alloy is used, cold forging may be performed.

  In addition, a material lubrication process and a mold lubrication process are performed before forging, but when performing cold forging, it is preferable to employ a bonde process (zinc phosphating process) as the material lubrication process.

  When the hot forging is performed, it is preferable to use a graphite-based water-soluble lubricant as the material lubrication treatment.

  The mold lubrication treatment is not particularly limited, and may be appropriately adjusted so that the back pressure action by the preceding workpiece W is appropriately exhibited as described above.

  In the mold lubrication treatment, an oil-based lubricant or a water-soluble lubricant can be used, but it is preferable to use a water-soluble lubricant because of the high temperature.

  Furthermore, depending on the alloy type of the forging material W1, only the material lubrication process may be performed without necessarily performing the mold lubrication process.

  In this embodiment, various conditions such as temperature conditions during forging may be appropriately adjusted according to the mass of the workpiece W, the cross-sectional area, and the alloy type.

  For example, when performing by hot forging, it is preferable to set the temperature of the upper mold 1 to about 50 to 200 ° C., the temperature of the lower mold 2 to about 150 to 350 ° C., and the material temperature to about 350 to 500 ° C.

  Furthermore, when it implements by cold forging, it is good to set the temperature of the metal mold | die 1 and 2 to about normal temperature-150 degreeC, and a raw material temperature to about normal temperature.

Furthermore, the load of the upper die 1 at the time of molding can be performed, for example, at 250 t or less (2.5 × 10 ⁶ N or less) when the workpiece diameter is 100 mm.

    In the present embodiment, a large amount of lubricant is applied when forging the second and subsequent workpieces W so that the preceding workpiece W to be discharged can be smoothly detached without sticking to the subsequent workpiece W. Good to do. Further, it is possible to improve the detachability between the works by devising such as inserting an aluminum foil or the like between the works W.

  Further, a guide plate (not shown) that is inclined with respect to the axial center direction (vertical direction) is disposed below the work discharge port 45 of the lower mold 2, and the work W discharged from the work discharge port 45 is disposed. By guiding the guide W in an oblique direction along the guide plate, the discharged work W may be bent with respect to the subsequent work W and detached.

Second Embodiment
FIG. 6 is a half-cut perspective view showing a mold of a forging device according to a second embodiment of the present invention. As shown in the figure, the forging device of the second embodiment is different from the forging device of the first embodiment in that the axial direction (vertical direction) length of the lower mold 2 is different. That is the point.

  That is, in the lower mold 2 in the first embodiment, the axial length of the workpiece molding hole 41 is set to be substantially the same as the axial length of the forged molded product W2 to be molded. However, in the lower mold 2 in the second embodiment, the axial length of the molding hole 41 is shorter than the axial length of the forged molded product W2 to be molded, and the axial direction of the forged molded product W2 It is set to about 1/3 of the length.

  In the second embodiment, other configurations are substantially the same as those in the first embodiment, and therefore, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  In the forging device of the second embodiment, substantially the same operation as the forging device of the first embodiment is performed.

  That is, as shown in FIG. 7A, the first forging material W <b> 1 is put into the workpiece installation hole 31 in the lower mold 2, and the upper mold 1 is driven into the workpiece installation hole 31. Thus, the first workpiece W is press-fitted so as to be screwed into the workpiece molding hole 41 while plastically flowing. Then, as shown in FIG. 7B, the work W has a lower portion protruding through the work discharge hole 45 through the work forming hole 41, and an upper end portion in the work forming hole 41. The workpiece is retained in the workpiece forming hole 41 by the workpiece pull-out resistance force similar to that of the embodiment.

  Subsequently, in a state where the first (preceding) workpiece W is retained in the workpiece forming hole 41, the second and subsequent (following) workpieces W are thrown into the workpiece setting hole 31, and the top Die 1 is driven in. As a result, as shown in FIGS. 8A and 8B, the succeeding workpiece W is press-fitted into the workpiece molding hole 41 so as to be screwed into the workpiece molding hole 41 while projecting the preceding workpiece W downward. Then, as shown in FIG. 8C, the succeeding workpiece W is stopped with the lower portion passing through the workpiece molding hole 41 and only the upper end portion being press-fitted into the workpiece molding hole 41, while the preceding workpiece W is It is discharged from the discharge port 45 while being twisted and rotated, separated from the subsequent workpiece W and dropped.

  Also in the second embodiment, as in the first embodiment, the preceding workpiece W has a back pressure that uses the workpiece ejection resistance force when the preceding workpiece W is projected from the workpiece molding hole 41 as a back pressure. It functions as an imparting member.

  In the second embodiment, similar to the first embodiment, the same operational effects can be obtained, and the length of the work molding hole 41 in the axial direction (vertical direction) is short. The mold 2 can be made compact and compact.

  However, in the second embodiment, only the upper end portion of the preceding work W is disposed in the work forming hole 41. Therefore, from the point when the preceding work W comes out of the work forming hole 41 and is separated, The workpiece W is molded by the workpiece molding hole 41 without receiving back pressure.

  In the second embodiment, the axial length of the workpiece forming hole 41 is made shorter than the axial length of the forged product W2, but the present invention is not limited to this, and conversely in the present invention. The length of the workpiece molding hole 41 may be longer than the length of the forged molded product W2. In this case, a plurality of workpieces W can be stopped in the workpiece molding hole 41, and the workpiece protrusion resistance can be further increased.

<Third Embodiment>
FIG. 9 is a half-cut perspective view showing a die of a forging device according to a third embodiment of the present invention, and FIG. 10 is a perspective view showing a forging material W1 processed by the forging device of the third embodiment. As shown in both drawings, in the third embodiment, the forged material W1 is largely different from that of the first embodiment in that a forged material W1 is formed of a cast part that is not extruded. ing.

  That is, the forging material W1 is formed in a columnar or disk shape, and the manufacturing method thereof is as described in the first embodiment.

  In addition, the workpiece setting die 3 in the lower die 2 is formed such that the horizontal section shape of the workpiece setting hole 31 is circular corresponding to the horizontal sectional shape of the columnar forging material W1.

  Further, the upper mold 1 is formed in a circular shape so that the horizontal cross-sectional shape thereof corresponds to the horizontal cross-sectional shape of the work installation hole 31 of the lower mold 2 and can be inserted into the work installation hole 31.

  The workpiece installation hole 31 is set to be equal to or slightly larger than the circumscribed circle so that the forging material W1 can be introduced in the horizontal sectional shape.

  Furthermore, when the diameter of the workpiece installation hole 31 and the diameter of the cut product of the continuous cast bar are greatly different, a pre-formed (forged or upset) product of the cut product can be used as the forging material W1 (described later). The same applies to the fifth embodiment).

  In the third embodiment, other configurations are substantially the same as those in the first embodiment, and therefore, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  In the forging device according to the third embodiment, substantially the same operation as the forging device according to the above embodiment is performed.

  That is, the first forging material W1 is put into the workpiece installation hole 31 and the upper mold 1 is driven. Thus, the forging material W1 is press-fitted and filled so as to be plastically flowed and screwed into the workpiece molding hole 41.

  Subsequently, in a state where the first (preceding) workpiece W is retained in the workpiece forming hole 41, the second and subsequent (following) workpieces W are thrown into the workpiece setting hole 31, and the top Die 1 is driven in. As a result, the succeeding workpiece W is pressed into the workpiece molding hole 41 so as to be plastically flowed and screwed while projecting the preceding workpiece W downward, while the preceding workpiece W is twisted and rotated from the workpiece discharge port 45. It is discharged and falls.

  Needless to say, also in the third embodiment, the preceding workpiece W functions as a back pressure application member with respect to the following workpiece W, as in the above embodiment. This back pressure function is the same in the following fourth and fifth embodiments.

  In the third embodiment, the same function and effect can be obtained as in the above embodiment.

<Fourth embodiment>
FIG. 11 is a half cutaway perspective view showing a die of a forging device according to a fourth embodiment of the present invention, FIG. 12 is a perspective view showing a forged molded product W2 after being processed by the forging device, and FIG. It is a perspective view which shows the forge raw material W1 before being processed with an apparatus. As shown in these drawings, in the fourth embodiment, a forged product W2 having a shape different from those of the first to third embodiments is manufactured.

  That is, in the first embodiment, the forged molded product W2 constituting the rotor component employing the three-leaf type twist lobe having three lobes W3 provided on the outer periphery is manufactured (see FIG. 4). The forged molded product W2 manufactured in the fourth embodiment is for manufacturing a forged molded product W that constitutes a rotor part that employs a four-leaf twist lobe having four lobes W3 provided on the outer periphery.

  Further, the forging material W1 for processing the forged molded product W2 is made of an extrusion molded product, and is provided with four lobe corresponding portions parallel to the axial direction corresponding to the four lobes W3. . In addition, the method for producing the forging material W1 by the extrusion-molded product is substantially the same as that in the first embodiment.

  The workpiece setting die 3 in the lower die 2 is formed so that the horizontal sectional shape of the workpiece setting hole 31 corresponds to the horizontal sectional shape of the forging material W1, and the workpiece molding hole 41 is forged. It is formed corresponding to the outer peripheral shape of the product W2.

  Further, the upper mold 1 is formed so that the horizontal cross-sectional shape thereof corresponds to the horizontal cross-sectional shape of the work installation hole 31 and can be inserted into the work installation hole 31.

  In the fourth embodiment, other configurations are substantially the same as those in the first embodiment, and thus the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  Also in the forging device of the fourth embodiment, the subsequent workpiece W is thrown into the workpiece installation hole 31 while the preceding workpiece W is stopped in the workpiece molding hole 41 as in the above embodiment. Then, by driving the upper mold 1, the preceding workpiece W is ejected downward and discharged, and the succeeding workpiece W is press-fitted into the workpiece molding hole 41 and molded.

  In the fourth embodiment as well, the same operational effects are obtained as described above.

<Fifth Embodiment>
FIG. 14 is a half-cut perspective view showing a mold of a forging device according to a fifth embodiment of the present invention. As shown in the figure, in the fifth embodiment, as the forging material W1, one constituted by a cast part that is not extruded is used.

  This forging material W1 is formed in a columnar shape or a disk shape as in the third embodiment (see FIG. 10).

  Further, the workpiece setting die 3 in the lower die 2 has a workpiece installation hole 31 formed in a columnar shape corresponding to the columnar forging material W1, and the upper mold 1 has a workpiece installation hole 31. Is formed in a columnar shape.

  In the fifth embodiment, the other configurations are substantially the same as those in the fourth embodiment, and thus the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  Also in the forging device of this fifth embodiment, the subsequent workpiece W is thrown into the workpiece installation hole 31 while the preceding workpiece W is stopped in the workpiece molding hole 41 as in the above embodiment. Then, by driving the upper mold 1, the preceding workpiece W is ejected downward and discharged, and the succeeding workpiece is press-fitted into the workpiece molding hole 41 and molded.

  In the fifth embodiment as well, the same operational effects are obtained as described above.

<Modification>
In the embodiment described above, the spirally wound groove portion 42 is formed on the inner peripheral surface of the workpiece molding hole 41, and the preceding workpiece W is discharged while being twisted and rotated along the groove portion 42. A sufficient frictional resistance force (workpiece pull-out resistance force) is generated between the surface and the inner peripheral surface of the workpiece forming hole. In the present invention, means for generating a workpiece pull-out resistance force (work tension force) ( The work removal resistance means) is not limited to that.

  For example, a female screw groove or gear tooth groove such as a V-shape or U-shape is spirally formed on the inner peripheral surface of the workpiece forming hole, and the preceding workpiece W is twisted along the spiral groove. By discharging while rotating, it may be configured to generate a sufficient workpiece pull-out resistance force between the workpiece outer peripheral surface and the workpiece molding hole inner peripheral surface.

  These workpiece pull-out resistance means are configured by changing the horizontal cross-sectional shape of the work forming hole so that it gradually shifts around the axis as it goes downward, in other words, in the vertical cross-sectional shape, Although it is configured by engaging the ridge (overhang) with the groove of the workpiece forming hole, the present invention is not limited to this, without forming an overhang such as the ridge. Also, it is possible to constitute a work removal resistance means.

  In other words, the inner surface of the workpiece forming hole is increased in surface roughness (surface roughness) and finished to a rougher surface than the inner surface of the workpiece mounting hole to increase the frictional resistance with the workpiece and increase the frictional resistance. You may make it function as workpiece | work pull-out resistance.

  For example, the lower the surface roughness of the inner surface of the workpiece molding hole is, the lower the surface roughness is, or the lower half of the inner surface of the workpiece molding hole is roughened to more than twice the surface roughness of the upper half. For example, a sufficient frictional resistance force (workpiece pull-out resistance force) may be applied to the workpiece.

  Further, the workpiece pull-out resistance is based on the frictional resistance with the workpiece, but is not limited thereto, and the workpiece pull-out resistance may be generated based on the deformation force of the workpiece.

  For example, by narrowing the lower side of the workpiece forming hole, the inner diameter of the workpiece forming hole is gradually reduced toward the lower side, and the workpiece is reduced in diameter when passing through the workpiece forming hole (drawing process). In addition, the reduced diameter deformation force may function as a workpiece pull-out resistance force.

  Specifically, for example, when the inner diameter of the upper half of the workpiece forming hole is “A”, the inner diameter of the lower half is “0.999 × A”, or the upper end is formed on the inner peripheral surface of the workpiece forming hole. A taper of 1 ° or less may be applied from the bottom to the bottom to form a lower drawing shape.

  Needless to say, when the workpiece forming hole is formed in a lower drawing shape, the horizontal cross-sectional shape is not limited to a circular shape, and may be another cross-sectional shape. Furthermore, the workpiece forming hole is not limited to a tapered shape whose inner diameter is continuously reduced, and the inner diameter may be reduced stepwise.

  Further, the inner peripheral wall temperature of the lower part of the work molding die may be set lower than the inner peripheral wall temperature of the upper part to generate a work removal resistance.

  That is, when the inner peripheral wall temperature of the workpiece molding die is lowered, the inner diameter of the workpiece molding hole is reduced due to thermal expansion. Therefore, for example, by setting the inner peripheral wall temperature of the lower half of the work molding die to be about 50% lower than the inner peripheral wall temperature of the upper half, the inner diameter of the lower half of the work molding hole is set to the upper half. As described above, the workpiece pull-out resistance may be generated by reducing the size of the workpiece and drawing the workpiece.

  By the way, as described above, as a method of generating the workpiece pull-out resistance, a method of forming a helically wound or spiral groove, a method of increasing the surface roughness of the inner peripheral surface of the workpiece molding hole, However, in the present invention, any one of these methods may be used alone to generate the workpiece pull-out resistance force. You may make it generate | occur | produce the workpiece | work pull-out resistance force together using the above method.

  Further, in the present invention, the workpiece pull-out resistance means constituted by the groove portion, the rough surface portion, the drawing portion, etc. is not necessarily provided in the entire inner peripheral surface of the workpiece molding hole, and is provided in a part of the workpiece molding hole. Anyway.

  Further, in the above embodiment, the workpiece withdrawal resistance means is provided in the workpiece molding hole. However, the present invention is not limited thereto. In the present invention, the workpiece withdrawal resistance means is provided below the workpiece molding hole. Also good.

  For example, a work-holding mold having a work-holding hole is arranged on the lower side of the work-molding mold, and the above-mentioned work-out resistance means is provided on the inner peripheral surface of the work-holding hole. The work protruding from the work forming hole may be retained in the work retaining hole by the resistance of the work removal resistance means.

  Moreover, in the said embodiment, although the case where a rotor component with a three-leaf type or a four-leaf type twist lobe was manufactured as a forged molded product was described as an example, the present invention is not limited thereto, and the present invention is not limited to this. It is also possible to produce the part as a forged product.

  For example, helical gear teeth such as helical gears, male screw-like parts with a thread formed entirely or partially, twisted parts with a whole or part twisted, and other twists It is also possible to form a straight part having the same cross-sectional shape at any position in the axial center direction without any thread or thread.

  However, male threaded parts and twisted parts are particularly useful as forged products (workpieces) when carrying out the present invention, since they can appropriately impart a workpiece pull-out resistance when forging.

  The forging method of the present invention can be applied to a die forging technique in which a workpiece is forged using a die.

1: Upper die (punch)
2: Lower mold (die)
21: Through hole 31: Work installation hole 41: Work forming hole 42: Work forming groove W: Work W1: Forged material W2: Forged product W3: Robe (projection)

Claims (14)

It has a through-hole with both ends open, and one side of the through-hole is configured as a workpiece installation hole on which a workpiece is installed, and the other side is configured as a workpiece molding hole for molding the workpiece. With dice,
With the workpiece installed in the workpiece installation hole, a punch that press-fits the workpiece while plastically flowing into the workpiece molding hole by being driven into the through hole from one end side thereof,
A workpiece pull-out resistance means is provided, which applies a workpiece pull-out resistance force that becomes a resistance when the workpiece in the workpiece molding hole moves to the other end side, and stops the workpiece in the workpiece molding hole. ,
In a state where the preceding workpiece is stopped in the workpiece forming hole, the succeeding workpiece is set in the workpiece setting hole, and the punch is driven into the through hole. A forging method characterized by projecting from the other end side of the through-hole and press-fitting a subsequent workpiece into the workpiece molding hole.   The forging method according to claim 1, wherein the other end surface of the preceding workpiece is used as a constraining surface when the subsequent workpiece is formed.   When the punch is driven into the through-hole, the preceding workpiece is pushed out against the workpiece pull-out resistance force, so that the preceding workpiece has the workpiece pull-out resistance force against the subsequent workpiece. The forging method according to claim 1, wherein the forging method is configured to function as a back pressure applying member that is used as a pressure.   The forging method according to any one of claims 1 to 3, wherein a frictional resistance force between a preceding workpiece and the inner peripheral surface of the workpiece molding hole is caused to function as the workpiece withdrawal resistance force.   The forging method according to any one of claims 1 to 4, wherein a die for forming a workpiece is formed on the inner peripheral surface of the workpiece molding hole in a spiral or spiral shape as the die.   The forging method according to any one of claims 1 to 5, wherein a die having a drawing portion for reducing the diameter of a workpiece is provided in at least a part of the workpiece molding hole.   The forging according to any one of claims 1 to 6, wherein the die is formed such that a length in the axial direction of the workpiece forming hole is shorter than a length in the axial direction of the workpiece after molding. Method.   The forging method according to any one of claims 1 to 7, wherein a die having a portion having a high surface roughness is provided on the inner peripheral surface of the workpiece forming hole.   The forging method according to claim 1, wherein the workpiece is made of aluminum or an aluminum alloy.   The forging method according to any one of claims 1 to 9, wherein a forged product in which the ridge portion is formed in a winding shape or a spiral shape on the outer peripheral surface is manufactured.   The forging method according to any one of claims 1 to 10, wherein a rotor part of a supercharger for an automobile is manufactured.   The forging method according to any one of claims 1 to 3, wherein the workpiece is reduced in diameter in the workpiece forming hole, and a deformation force at the time of the reduced diameter deformation is caused to function as the workpiece withdrawal resistance force. It has a through-hole with both ends open, and one side of the through-hole is configured as a workpiece installation hole on which a workpiece is installed, and the other side is configured as a workpiece molding hole for molding the workpiece. With dice,
With the workpiece installed in the workpiece installation hole, a punch that press-fits the workpiece while plastically flowing into the workpiece molding hole by being driven into the through hole from one end side thereof,
A workpiece withdrawal resistance means for applying a workpiece withdrawal resistance force that becomes a resistance when the workpiece in the workpiece molding hole moves to the other end side, and for stopping the workpiece in the workpiece molding hole,
In a state where the preceding workpiece is stopped in the workpiece forming hole, the succeeding workpiece is set in the workpiece setting hole, and the punch is driven into the through hole. A forging die characterized by protruding from the other end side of the through-hole and press-fitting a subsequent workpiece into the workpiece molding hole.   A forging device comprising the forging die according to claim 13.

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