JPWO2007013675A1 - Forging mold, forged molded product manufacturing method and forged molded product - Google Patents

Abstract

In the forging die (30) having the gas vent passage (34) for discharging the gas confined in the molding hole (35) of the forging die during molding, the gas vent passage is perpendicular to the gas flow direction. Having a plurality of step portions having different cross-sectional areas in the direction, the opening area of the first step portion (X) facing the molding hole wall surface is smaller than the opening area of the second step portion (Y) connected thereto, And since the opening is provided in the wall surface which consists of a mold division part, or the wall surface which consists of an integral mold part, even if the forging material which entered the gas vent passage breaks at the time of product discharge, the gas pressure at the next forging Is pushed to the next stage, and the gas vent passage is not blocked. Therefore, it is possible to produce a forged molded article with good dimensional accuracy in which the gas confined in the molding hole is smoothly released even if it has a complicated mold shape, and the occurrence of a lack of thickness is suppressed.

Description

  The present invention relates to a forging die, a forging molded product manufacturing method, a forging device, and a forging molded product for manufacturing a forged molded product having a complicated shape without lack of thickness.

When manufacturing a product having a complicated shape by forging, it is important to ensure sufficient meat and dimensions of each part of the product.
For example, when forging a scroll made of an aluminum alloy, which is an example of a product with a complicated shape, it is difficult to form a spiral blade, and a spiral blade having a uniform height and thickness is formed. It was an issue to do. As a cause of the difficulty, it has been considered that it is difficult to obtain a forged product with good dimensional accuracy as a result of the inflow of the forging material being blocked by the air confined in the cavity.
Therefore, Japanese Patent Application Laid-Open No. 10-118734 discloses a mold for the purpose of preventing a forging material from being blocked by air confined in a cavity and obtaining a forged product with good dimensional accuracy. Discloses a method of providing an air vent.
Moreover, the hole diameter, opening position, etc. of the air bed are disclosed as follows.
The diameter of the hole is preferably 1 mm or more, and can be as large as the thickness width at that position. If the hole diameter of the air vent does not reach 1 mm, the forging material pushed into the hole during forging may be broken when the forged product is taken out from the mold, and may remain in the hole. As a result, the action of an air vent that releases air in the cavity at the time of the next forging cannot be expected. However, in a hole having a diameter larger than the wall thickness, the volume of the forging material that flows in becomes too large, and a thin wall tends to occur near the hole. In addition, since a relatively large protrusion is formed, it becomes difficult to scrape the protrusion from the product after forging, and the product yield is also reduced.
The position to open the air vent is determined according to the shape of the product. However, as long as the air is likely to accumulate, any of the corners, dead ends, thick parts of the product, and parts with a large change in thickness, etc. It may be. Further, when the air vent is opened symmetrically with respect to the product, the flow of the forging material becomes smooth, and the dimensional accuracy of the forged product is further improved. Furthermore, the hole portion of the air vent can be used as a forging material reservoir so that the plastic flow of the forging material in each part is constant. Although depending on the punch speed (forging speed), the air vent needs to have a number and size that allow the air in the cavity to escape smoothly without being compressed. Since forging is performed using a mold provided with an air vent, a forging material protrudes like a wart in an obtained forged product corresponding to the opening position of the air vent. This protrusion is removed from the forged product by belt sander, machining or the like.
As a countermeasure against the above problem, Japanese Patent Application Laid-Open No. 10-272532 discloses that the clearances of the fitting part and the contact part of the mold dividing part (which is fixed by a slit and not sliding) are degassed. It may be used as a passage. Japanese Patent Application Laid-Open No. 61-154727 also discloses a method in which a mold sliding portion composed of a die and a knockout pin is used as a vent hole. The mold division unit indicates a boundary portion of the divided body when the mold is divided into a plurality of divided bodies. In addition, the mold sliding portion indicates a boundary portion of the mold in which at least one of the divided bodies slides and slides.
When an air vent hole such as a conventional forging die is provided, the hole diameter is simply Φ1 mm or more, and as a result, the amount of forging material pushed into the air vent hole is increased. A defect occurred in that the product was given a pin-like shape (hereinafter referred to as an air pin). This is particularly likely to occur when forging a product that requires a high forging load, or when it is installed at a location close to the mold dividing position.
Further, when the clearance with the knockout pin that is the mold sliding portion is used as a gas vent passage, the forging material easily enters the clearance portion. As a result, burrs are likely to occur, so that when the knockout occurs, the burrs that have penetrated are removed and accumulated in the clearance area, causing a problem in that the knockout pin is difficult to slide. There were many problems. Moreover, the tendency becomes remarkable when using a vent hole together. Furthermore, when the sliding part is used, there is no degree of freedom in mold design because there are restrictions on the place where the sliding part is arranged.
In addition, when using a mold dividing part (part that does not slide due to a gap), if the clearance between molds is small or the amount of clearance (tightening margin) is large, the necessary passage cannot be secured and sufficient gas venting is achieved. Since the effect is not obtained and the gas remains, there is a possibility that a lack of thickness occurs and molding becomes poor. On the contrary, when the clearance between the molds is large or the amount of looseness (tightening allowance) is small, the forging material is likely to enter, so that the generation of burrs increases.
Therefore, in particular, there is a need for a degassing passage suitable for providing a product that requires a high forging load and a shape that requires a degassing hole at a location close to the mold dividing position with high accuracy. Yes. In this specification, the gas includes a gas in the atmosphere of the forging process, for example, air, an inert gas, or a vaporized lubricant, for example, water vapor, vaporized oil, or the like.
The present invention has been completed in view of such a situation, and even if it has a complicated shape, it suppresses the occurrence of thinning due to air confined in the molding hole of the mold, and is sufficiently forged in the molding hole. An object is to obtain a forged product with good dimensional accuracy by flowing the material.

The present invention relates to (1) a forging die having a gas vent passage for discharging gas trapped in a molding hole of a forging die at the time of molding, wherein the gas vent passage is perpendicular to the gas flow direction. A plurality of step portions having different cross-sectional areas, the opening area of the first step portion facing the molding hole wall surface is smaller than the opening area of the second step portion connected thereto, and the opening portion is divided into molds The forging die is provided on a wall surface made of a portion or a wall surface made of an integral mold portion.
Note that the above-mentioned mold dividing part is a part of the boundary part of the divided body when the mold is divided into a plurality of divided bodies, and is fixed so that the divided body does not slide due to fraying etc. It is. Moreover, said integral type part is the site | part comprised by the mold component parts which are not divided | segmented. This includes the case where the entire mold is manufactured as a single unit.
(2) The forging die according to (1), wherein the cross-sectional area of the opening formed in the wall surface of the forming hole is 0.01 to 1 mm ² .
(3) The forging die according to (1) or (2), wherein a diameter of an inscribed circle having a cross-sectional shape of the opening formed in the wall surface of the forming hole is 0.1 to 1 mm.
(4) Any of the above (1) to (3), wherein the area after the next stage of the degassing passage of the opening formed in the wall surface of the forming hole is 1.04 times or more of the area on the opening side 1. A forging die according to 1.
(5) The length of the shape part by the side of the opening formed in the said shaping | molding hole wall surface is 1-15 times the area value by the side of an opening part, Any one of said (1)-(4) This is a forging die.
(6) In the present invention, the opening is provided at a position where a gas pool confined in a recess and / or a groove formed by a molding wall surface of a molding hole and a forging material is generated. (5) The forging die according to any one of (5).
(7) The present invention uses the forging die described in any one of (1) to (6) above, throws the forging material into the forming hole, and inserts the forging material into the recess and / or groove of the forming hole. It is a manufacturing method of a molded product forging while letting the trapped gas escape through the gas vent passage.
(8) The forging as described in (7) above, wherein the forging material is any one metal selected from aluminum, iron, magnesium, and titanium, or an alloy containing these as a main component. Product manufacturing method.
(9) The present invention includes a forged product manufactured by the method described in (7) above.
(10) The present invention includes a forging device having the forging die described in any one of (1) to (6).
According to the present invention, in the forging die having the gas vent passage for discharging the gas confined in the molding hole of the forging die at the time of molding, the gas vent passage is cut in a direction perpendicular to the gas flow direction. It has a plurality of step portions having different areas, the opening area of the first step portion facing the molding hole wall surface is smaller than the opening area of the second step portion connected thereto, and the opening portion is a mold dividing portion Since the forging material that has entered the gas vent passage breaks in the gas vent passage when the product is discharged, the pressure of the gas during the next forging Pushed to the next step, clogging is eliminated, and the gas vent passage is not blocked. Therefore, even if it is a complicated shape, the gas confined in the molding hole of the mold can be smoothly released, and the forging material can be sufficiently flowed into the molding hole. As a result, it is possible to manufacture a forged molded article with good dimensional accuracy that suppresses the occurrence of thinning due to the trapped gas.
Moreover, since the area of the opening formed in the wall surface of the molding hole is reduced, the shape of the air pin is narrowed and shortened, so that the removal work from the product can be reduced.
Moreover, since the cross-sectional area of the opening formed in the wall surface of the molding hole is 0.01 to ¹ mm ² , the shape of the air pin is narrowed and shortened, so that the removal work from the product can be reduced. Moreover, since the diameter of the inscribed circle of the cross-sectional shape of the opening formed in the wall surface of the molding hole is 0.1 to 1 mm, the shape of the air pin is thin and short, and the removal work from the product can be reduced. Further, since the area after the next stage of the degassing passage of the opening formed in the wall surface of the forming hole is 1.04 times or more of the area on the opening side, the passage wall surface is clogged without contacting with the air pin. Low resistance can be achieved at the time of elimination.

FIG. 1 is a perspective view showing an example of a forged product suitable for manufacturing with the forging die of the present invention.
FIG. 2 is a perspective view showing another example of a forged product suitable for manufacturing with the forging die of the present invention.
FIG. 3 is a perspective view showing another example of a cast product suitable for manufacturing with the casting mold of the present invention.
FIG. 4 is a longitudinal sectional view showing an example of a forging die according to the present invention.
FIGS. 5A to 5E are enlarged longitudinal sectional views showing an example of a gas vent passage used in the forging die.
6 (A) to 6 (D) are a plan view and a cross-sectional view of a main part of a gas vent passage used for the forging die.
FIG. 7 is an enlarged cross-sectional view of a gas reservoir of the forging die shown in FIG.
FIGS. 8A to 8C are explanatory views showing respective forming steps of the forging material using the forging die of the present invention.
9 (A) to 9 (F) are explanatory views showing respective forming steps of the forging material using the forging die of the present invention.
10 (A) to 10 (E) are explanatory views showing respective forming steps of the forging material using the forging die of the present invention.
FIG. 11 is an explanatory view showing an embodiment of a forging device used in the present invention.
FIG. 12 is an enlarged longitudinal sectional view showing an example of a gas vent passage provided with a control pin.
FIG. 13 is a longitudinal sectional view showing an example of a mold for forging the forged product of FIG.
FIG. 14 is a longitudinal sectional view showing an example of a mold for forging the forged product of FIG.
FIG. 15 is an enlarged cross-sectional view of the mold shown in FIG.

  The forging die of the present invention has a plurality of step portions having different cross-sectional areas, and the opening area of the first step portion facing the forming hole wall surface is smaller than the opening portion area of the second step portion connected thereto, In addition, by providing a gas vent passage whose opening is provided on the wall surface made of the mold dividing portion or the wall surface made of the integral mold portion, clogging of the gas vent passage is prevented, and the occurrence of thinning is suppressed. It is possible to produce a forged molded article with good dimensional accuracy.

鍛造結果は、表２に示す。
表２より明らかなように、実施例１では、荷重２８０ｔ、第１段部Ｘの径はφ０．３ｍｍ、第１段部Ｘの長さは５．０ｍｍ、第２段部Ｙの径はφ１．０ｍｍ、接続部Ｚの角度９０度、エアーピン長さ１．５ｍｍ、目詰まり現象は無しであった。
実施例２では、荷重２８０ｔ、第１段部Ｘの径はφ０．５ｍｍ、第１段部Ｘの長さは５．０ｍｍ、第２段部Ｙの径はφ１．０ｍｍ、接続部Ｚの角度９０度、エアーピン長さ３．０ｍｍ、目詰まり現象は無しであった。
実施例３では、荷重２８０ｔ、第１段部Ｘの径はφ０．５ｍｍ、第１段部Ｘの長さは１２．０ｍｍ、第２段部Ｙの径はφ１．０ｍｍ、接続部Ｚの角度９０度、エアーピン長さ３ｍｍ、目詰まり直後の鍛造工程では解消されず、その次の３回目の鍛造工程で解消した。
比較例１（従来）では、荷重２８０ｔ、第１段部Ｘの径はφ０．５ｍｍ、第２段部Ｙの径はφ０．５ｍｍ（段部を有していない。）、接続部Ｚの角度０度、エアーピン長さ３ｍｍ、目詰まり現象は存在した。
比較例２（従来）では、荷重２８０ｔ、第１段部Ｘの径はφ１．１ｍｍ、第２段部Ｙの径はφ１．１ｍｍ（段部を有していない。）、接続部Ｚの角度０度、エアーピン長さ１４ｍｍ、目詰まり現象は無しであった。しかし、エアーピンが長く、次のトリム工程で不良品が発生した。

第１３図は、金属素材かつ鍛造成形品を鍛造するための鍛造用金型の第２実施例を示し、第４図の金型と同様に金型３０は、下金型３１と上金型３２および成形品を下金型３１内から取り出すためのノックアウトピン３３、またはガス抜き通路３４を含んで構成されている。また、下金型３１及び上金型３２は、中心部に鍛造成形孔３５がそれぞれ設けられている。
この鍛造用金型は、第２図に示すようなベースプレートド面１３と羽根部１４から成るスクロール式コンプレッサーの渦巻体を成形するのに好的に用いられる。
この渦巻体の成形は、凸部１２を有するベースプレート面１３が成形された後に、羽根部１４に素材が塑性流動して成形が完了する。この凸部１２の成形時に、その部位にガスが閉じ込められる。ガス抜き通路は、ガスが閉じ込められる箇所に設けるのが好ましい。その結果、閉じ込められた空気による欠肉の発生を抑えることが出来るからである。
従って、本実施例ではガス抜き通路３４は、ガスの閉じ込められる部位である、凸部１２に対応した位置に設置している。
第１４図は本発明による鍛造用金型の第３実施例を示し、第１３図の金型と同様に、本実施例の金型３０は、下金型３１にガス抜き通路３４が設けられている。
この鍛造用金型３０は、第３図に示すようなヘッド面１５，スカート部１６，リブ部１７、ピンボス部１８を有する内燃機関のピストンを成形するのに好的に用いられる。
第１５図は、上記内燃機関のピストンのリブ部１７、スカート部１６でのガス抜き通路付近の成形時の空気の溜まり部の拡大断面図であって、空気溜まりの発生する様子を模式的にしたものです。
内燃機関ピストンの成形は、ヘッド面１５が成形された後に、リブ部１７、スカート部１６、ピンボス部１８に素材が塑性流動して成形が完了する。ガス抜き通路３４は成形順序で最後に成形される箇所に設けるのが好ましい。その結果、閉じ込められた空気による欠肉の発生を抑えることが出来るからである。
従って、本実施例ではガス抜き通路３４は、最後に成形される部位である。リブ部、スカート部、ピンボス部に設置している。An example of the embodiment of the present invention will be described below.
<Description of molded products>
The complicated shape of the molded product that is the subject of the present invention is that the rib 11 is high as shown in FIG. 1, and the periphery is a concave portion as shown in FIG. It has a shape in which the convex 12 is substantially increased, or a shape like a piston of an internal combustion engine as shown in FIG.
This is because the portion of the mold corresponding to such a shape becomes a concave portion and / or a groove portion that is closed by the mold wall surface and the forging material, and gas is confined therein, and gas accumulation is likely to occur. . Examples of products having such a shape include a double-head piston of a swash plate compressor, a scroll body of a scroll compressor, and an internal combustion engine piston. The present invention is also intended for the case of directly molding products having these shapes, and when molding primary processed molded articles having these shapes.
FIG. 13 shows a second embodiment of a forging die for forging a forging-formed product from a metal material. Like the die shown in FIG. 4, the die 30 includes a lower die 31 and an upper die. 32 and a knockout pin 33 for taking out the formed product from the lower mold 31 or a gas vent passage 34. The lower mold 31 and the upper mold 32 are each provided with a forging hole 35 at the center.
This forging die is preferably used for forming a scroll body of a scroll compressor comprising a base plate surface 13 and blades 14 as shown in FIG.
FIG. 14 shows a third embodiment of the forging die according to the present invention. Like the die shown in FIG. 13, the die 30 of this embodiment is provided with a gas vent passage 34 in the lower die 31. It has been.
This forging die 30 is preferably used for molding a piston of an internal combustion engine having a head surface 15, a skirt portion 16, a rib portion 17, and a pin boss portion 18 as shown in FIG.
<Description of forging die>
An embodiment of a mold provided with a gas vent passage will be described with reference to FIG.
The forging die 30 of the present invention includes a lower die 31 and an upper die 32 for forging a forged molded product from a metal material, a knockout pin 33 for taking out the molded product from the lower die 31, and a gas vent. A passage 34 is included. The dies 31 and 32 are each provided with a forging hole 35 at the center.
This forging die is, for example, a forging die used for forging a double-headed piston as a forging product having ribs 11 parallel to the operation direction axis of the upper die as shown in FIG. It is. Hereinafter, description will be made based on the forging of this double-headed piston. For example, die steel or the like can be used as the material of the forging die 30.
<Description of the gas vent passage>
Degassing passage shape
For example, as shown in FIG. 5A, the gas vent passage 34 of the present invention has a two-part configuration of at least a first step portion X and a second step portion Y in the gas flow direction. Further, a multi-stage configuration is possible. The first step portion X1 is a portion provided on the molding hole 35 side. Here, the connecting portion Z1 between the first step portion X1 and the second step portion Y1 may be connected so that the cross-sectional area of the second step portion Y1 is larger than the cross-sectional area of the first step portion X1. Moreover, you may have a cross-sectional area larger than 2nd step part Y1 partially.
The cross-sectional area of the opening 36 formed on the wall surface of the forming hole of the forging die 30 is, for example, 0.01 to 1 mm. ² To form. The diameter of the opening 36 may be 0.1 to 1 mm.
A conventionally well-known method can be used for processing and assembling the mold according to the present invention. Here, the gas vent passage 34 may be formed at any time before or after combining the split dies, but it is preferably formed after the coalescence in consideration of the accuracy of the gas vent passage. Further, even in the integrated type, the gas vent passage 34 may be created before or after the forging hole 35 is formed. However, considering the accuracy of the gas vent passage, the forging hole 35 is formed. It is preferable to form it after this.
The shape of the second step portion Y1 is not particularly limited. For example, a shape that has a sufficient length as a gas damper that temporarily stores the gas extruded from the air pin in an operation as described later, and a length that is sufficient to store the extruded air pin, or a gas Can be released into the atmosphere, and at the same time, an opening for removing the discharged air pin can be provided. For example, it can be set as the shape which has penetrated the forge metal mold | die 30 and has an open port in the outer surface.
<Cross sectional area of degassing passage>
The cross-sectional area of the first step portion X1 is 0.01 to 1 mm. ² (More preferably 0.03-0.2 mm ² ) Is preferable. On the other hand, the cross-sectional area of the second step portion Y1 is preferably 1.04 times or more (more preferably 1.3 to 3 times) the cross-sectional area of the first step portion.
By configuring the cross-sectional area of the first step portion X1 in this way, the hole diameter is reduced, and entry of the forging material can be suppressed, which is preferable.
By making the cross-sectional area of the second step portion Y1 1.04 times or more of the cross-sectional area of the first step portion X1, the forging after the air pin breaks in the gas vent passage because it does not contact the intruding forging material When the air pin is pushed by the gas pressure, it does not become a (friction) resistance when moving.
The diameter of the circumscribed circle of the cross section of the opening 36 is 1 mm or less, preferably 0.1 to 1 mm, more preferably 0.2 mm to 0.5 mm. Below that, drilling is difficult. If it exceeds that, the inflow of the forging material will increase, and the air pin after forging may become too long.
<Length of degassing passage>
The length of the first step portion X1 is preferably 1 to 15 times (more preferably 5 to 10 times) the area value of the first step portion X1. For example, the length of the first step portion X1 is preferably 1 to 10 mm. In addition, the length of the second step portion Y1 is preferably a length penetrating to the lower side of the lower mold 31 or above the upper mold 32.
By making the length of the first step portion X1 in this way, it is preferable because the (friction) resistance when the air pin is pushed and moved by the pressure of the gas during forging after the air pin is broken can be controlled. In addition, if the length of the first step portion X1 is less than 1 times the area value of the first step portion X1, the length may be short and the forging die may be missing. Furthermore, if the area value of the first step portion X1 is 15 times or more, the (friction) resistance is large, and the air pin may not come off.
The length of the second step portion Y1 is set in this way. If the effective length is determined, the clogged air pins may be accumulated up to the first step portion X1, and the effect of eliminating the clogging of the air pins is effective. Because it disappears.
Because it has such a shape, even if the forging material that has entered is broken in the gas vent passage 34 at the time of product discharge, when the molded product is continuously produced, the next stage is caused by the gas pressure at the next forging. It is pushed, clogging is eliminated, and the vent hole is not blocked. Therefore, even if it is a complicated shape, the air confined in the forging molding hole 35 of the mold can be smoothly released, and the forging material 39 can sufficiently flow into the molding hole.
Next, a specific example of the shape of the gas vent passage will be described with reference to the drawings.
FIG. 5 shows an example of a cross section substantially parallel to the gas flow direction in the passage shape example.
In FIG. 5A, as described above, the cross-sectional area of the first step portion X1 on the molding hole side is made smaller than the cross-sectional area of the second step portion Y1, and the first step portion X1 and the second step portion Y1 are formed. The connecting portion Z1 is a right-angled stepped portion.
FIG. 5 (B) shows another embodiment, to which the angle condition (θ) of the connecting portion Z2 between the first step portion X2 and the second step portion Y2 is given (0 degree <θ ≦). 90 degrees). More preferably, it is 1 degree or more. This is because the air pin can be easily broken with the same effect as FIG. 5C described later. Furthermore, there is no resistance when clogging is eliminated. Moreover, 10 degree | times or more are still more preferable.
The reason why the angle condition (θ) is preferably 10 degrees or more is that if the angle condition (θ) is 10 degrees or more, the forging material that has flowed in even at the connecting portion Z2 can be in a state of not contacting the wall surface of the gas vent passage 34. However, as a result, it is easier to eliminate in the forging process after clogging.
FIG. 5 (C) shows another embodiment, which is an example in which the first step portion X3 is formed in a tapered shape. When the taper is formed in a tapered shape with a different angle as in the present embodiment, the air pin is easily broken at the opening 37 when the product is discharged, and the air pin hardly remains on the product side, so that the product is actively clogged.
FIG. 5 (D) shows another embodiment, in which the first step portion X4 is formed in a tapered shape. When the taper is formed at a different angle as in the present embodiment, the air pin tends to break at the second step portion Y4 when the product is discharged, and the control of the pin length is intended. Further, since the root on the opening 38 side is thickened, it is difficult for the first step portion X4 to be clogged, and a preferable result can be obtained.
FIG. 5 (E) shows another embodiment of the present invention, in which the shape of the first step portion X5 is made uneven with different diameters, and the sectional shape of the gas vent passage is changed midway.
When comprised like a present Example, while the penetration of the forging raw material to the 1st step part X5 is suppressed, it makes it easy to cut | disconnect the forging raw material which penetrate | invaded.
Moreover, since the unevenness | corrugation amount of 1st step part X5 was 0.01-0.3 mm, clogging can be eliminated, without inhibiting that the forging material which penetrate | invaded by the pressure of gas is extruded to a lower step. Furthermore, the contour of the irregular shape can be a rectangular shape, a triangular shape, a sawtooth shape, or the like.
FIGS. 6 (A), (C) and (D) are plan views of the main part of the gas vent passage 34 used in the forging die of the present invention. Here, the cross-sectional shape is not particularly limited as long as a gas passage can be ensured, and the cross-sectional shape is not particularly limited, but a circular shape is preferable from the viewpoint of easy manufacture.
FIG. 6A shows a circular cross-sectional shape. The centers O of the first step portion X and the second step portion Y are made to coincide. The difference in size between the first step portion X and the second step portion Y is preferably 0.2 to 1 mm in radius. If it is less than 0.2 mm, the difference is small, and the air pin may come into contact with the inner periphery of the second step portion Y, and there is a possibility that the air pin is pushed by the gas pressure and becomes a (friction) resistance when moving. It is.
Further, as shown in FIG. 6B, when the diameter has a difference exceeding 1 mm, the difference between the first step portion X and the second step portion Y is large. That is, the projecting amount of the first step portion X is large and may be damaged.
FIG. 6C shows a case where the cross-sectional shape of the gas vent passage 34 is a square. The 2nd step part Y is the shape which offset the shape of the 1st step part X 0.2-1 mm outside.
FIG. 6D shows the case where the cross-sectional shape of the first step portion X is circular and the cross-sectional shape of the second step portion Y is square. The distance of the cross-sectional shape of the 1st step part X and the 2nd step part Y is 0.2-1 mm.
In FIGS. 6C and 6D, the cross-sectional shape is a square, but it can be a polygon or an ellipse. That is, the shape of the first step portion X and the second step portion Y can be any combination of a circle, a polygon, and an ellipse as long as the size difference (distance) is in the range of 0.2 to 1 mm. Is possible.
<Position of degassing passage>
The position of the opening 36 of the gas vent passage 34 with respect to the die forging hole 35 is determined according to the shape of the product. However, as long as the air is easily trapped, the corner portion and the dead end portion of the product. Any of a portion having a large thickness and a portion having a large change in thickness may be used. In particular, it is preferable to provide the portion formed last in the forming order because such a portion has a large degree of occurrence of a lack of wall due to trapped air, and can be eliminated.
The installation site of the gas vent passage 34 can be determined in consideration of the following, for example.
1) A place where gas accumulation is expected to occur in a place where the forging die 30 and the forging material are sealed during molding. This is because the gas pool causes forging defects (unformed). For example, in the forging die 30 shown in FIG. 4 corresponding to the molded product shown in FIG. 1, there is a possibility in eight parts indicated by reference numerals (a) to (h).
2) The location where the position of the knockout pin 33 is installed (the mold sliding part) has a clearance (necessary for the knockout pin to slide) in the knock hole and the knockout pin 33 of the mold. It is hard to become a gas reservoir. Therefore, after considering and taking into consideration the occurrence of forging defects, first, the knockout pin 33 is provided at a position where gas is likely to be accumulated. In FIG. 4, by installing four knockout pins 33, the target gas reservoir can be narrowed down from 8 parts to 4 parts (b), (c), (f), and (g).
3) Next, it is considered where the gas vent passage 34 is arranged in the gas reservoir. First, the flow of the forging material is taken into consideration, and the judgment criterion is where in the gas reservoir is formed last.
FIG. 7 shows an enlarged view of the gas reservoir of the forging die 30 shown in FIG. In the figure, the last part to be molded is expected to be (I), (J). Therefore, it is preferable to provide in these two places (I) and (J).
As a result, in the forging die 30 for the product shown in FIG. 1, it is necessary to install the gas vent passages 34 at 8 locations (= 2 locations / sites × 4 locations).
As a result, the mold is provided at a position where a gas reservoir (a portion that has become a closed space by the mold and the forging material) in which the opening is confined in the recess and / or groove of the molding hole is generated.
Note that the gas vent passage 34 of the present invention may be disposed in a mold dividing portion (not shown) of the forging die. However, the gas vent passage 34 according to the present invention does not need to be provided at the boundary of the sliding type where the opening 36 slides at least one of the divided bodies.
<Direction of degassing passage>
The direction of the gas vent passage 34 according to the present invention is not limited to being parallel to the forging direction (the moving direction of the mold). As a result, the degree of freedom in designing the mold is increased, so that a mold having a complicated shape can be easily designed.
In particular, when it is not parallel to the product discharge direction, the air pin can be easily cut, which is preferable.
Moreover, when raising the effect which suppresses raw material entry more, it sets to the diagonal direction (for example, the range of 45-90 degree | times with respect to the main forging direction or the moving direction of a metal mold | die, Preferably it is 45-70 degree | times). It is preferable.
<Example in which a control pin is inserted in the gas vent passage>
As shown in FIG. 12, a mechanism for inserting the control pin 90 into the second step portion Y after discharging clogging during forging may be provided. The control pin 90 is used for forging by retreating from the second step portion Y when clogging and does not hinder the discharge of the air pin and entering (raising) the second step portion Y during normal (not clogged). The material is prevented from entering the next stage (second stage Y) in the gas vent passage 34. Also, the control pin diameter is larger than the upper hole diameter and smaller than the lower hole, and the length is shorter than the lower hole length, preferably at the first decimal place, for example, preferably 0.01 to less than the lower step length. Shorten by 1 mm.
This is because the insertion pin length and the insertion amount can be controlled and suppressed by the presence of the control pin 90 even if the forging material enters the first step portion X.
If it is used together with the shape of the gas vent passage shown in FIG. 5 (D), it can be used without moving the control pin 90. This is because the opening is wide and the air pin is difficult to break.
<Relationship with lubricant discharge>
The gas vent passage 34 can also function as a passage for discharging the lubricant applied in the mold forming hole. Since it may be used for the purpose of eliminating the lack of lubrication residue, the shape accuracy of the molded product is improved synergistically.
<Description of the molding process in which the gas vent passage is not clogged>
FIG. 8 to FIG. 10 show the steps of material charging, molding, plugging burr status, discharge, and next molding using the forging die of the present invention.
First, FIG. 8A shows a process of placing a forging material 39 in a forging hole (cavity) 35 and press forging. The upper mold 32 is lowered and molding is performed.
In FIGS. 8 (B) and 8 (C), molding is performed from a shape portion close to the mold part. In the concave portion around the gas vent hole, a closed space is formed by the forging material 39 and the die. The closed space is filled with gas while being compressed.
9A, 9B, and 9C, the gas in the closed space formed by the forging die 30 and the forging material 39 is molded while being discharged from the gas vent passage 34.
In FIG. 9 (D), the molded product is discharged from the forging die with a knockout pin. At that time, the plug (air pin) 40 is broken, stays in the first step portion X of the gas vent passage 34, and clogging occurs.
FIGS. 9E, 9F, and 10A show the case where clogging is avoided by gas pressure during the next forging.
Due to clogging, the gas in the closed space remains without being discharged, but the gas is further compressed as the molding process proceeds. At the time immediately before the end of molding, finally, a compression force larger than the (friction) resistance force between the air pin 40 and the gas vent passage 34 is generated, and the air pin 40 previously clogged by the force is moved to the second step portion Y. Then, the air pin 40 is discharged, the clogging is eliminated, and the gas escapes.
10 (B), (C), (D), and (E) show the case where clogging is avoided by the gas pressure and the force of forming the material during the next forging.
In the compressed air pressure shown in FIGS. 9 (E), 9 (F) and 10 (A), the forging material flows during the second molding even if the air pin 40 cannot be moved to the lower stage. As a result, the gas compression rate is further increased, so that the air pin (clogging pin) 40 is pushed and moved to the lower stage. Further, when the forging material itself enters the gas vent passage 34, the air pin (clogging pin) 40 is pushed and moved directly to the lower stage.
In the method for producing a forged molded product of the present invention, the forged molded product can be stably produced continuously by repeating the above operation.
Here, the length of the first step portion X is set so as to be eliminated in the patterns shown in FIGS. 10B, 10C, 10D, and 10E, thereby eliminating clogging. Is more stable.
<Other embodiments>
The forging die 30 of the present invention has at least one gas vent passage 34 described above. In addition, a conventionally known gas vent passage may be combined. Even in such a case, the object of the present invention can be achieved by having the above-described gas vent passage.
<Description of forging materials>
The forging material 39 used in the present invention may be produced by any method such as continuous casting, extrusion, and rolling.
In the case of aluminum or an aluminum alloy, a continuously cast round bar is preferable because it is inexpensive. For example, SHOTTIC material (registered trademark) manufactured by Showa Denko KK can be used. In aluminum alloys, round bars continuously cast by the gas pressure hot top casting method have excellent internal soundness, fine crystal grains, and no crystal grain anisotropy due to plastic working Therefore, it is preferable because the resistance effect of the frictional resistance portion can be obtained stably.
The rod-shaped material is further cut into a predetermined length, subjected to a chamfering treatment if necessary, and sent to the next step.
<Forging process>
Forging in the present invention is die forging, and an example of the configuration of the forging device used in the present invention will be described with reference to FIG. The forging device includes a forging machine 81, an upper die 83 attached to the upper bolster 82, and a lower die 85 attached to the lower bolster 84. Moreover, an example of the metal mold | die used for this invention is shown in FIG. The forging die 30 includes a lower die 31 and an upper die 32 for forging a forged molded product from a metal material, a knockout pin 33 for taking out the molded product from the lower die 32, and a gas vent passage 34. It is configured to include.
The dies 31 and 32 are provided with a forging hole 35 at the center. Further, the forged molded product has a rib 11 shape parallel to the operation direction axis of the upper mold as shown in FIG. If necessary, a lubricant spray nozzle (not shown) is attached to the spray before / after device via a shaft (not shown) equipped with a spray forward / backward transfer device (not shown) and a spray rotating device (not shown). A lubricant applicator can be installed.
Here, the gas vent passage 34 is a gas vent passage having a plurality of steps having different cross-sectional areas in the vertical direction from the forging direction (moving direction of the mold).
The present invention can be applied regardless of whether it is hot, warm or cold. In general, the fluidity of the forging material changes depending on the forging temperature conditions, and the behavior of the forging material into the insertion burr and the gas vent passage changes. However, in the present invention, the clogging phenomenon can be solved regardless of the behavior of the forging material entering.
The prepared forging material 39 is pushed into a space (molding hole) 35 formed by the upper mold 32 and the lower mold 31 to forge-mold the molded product. Further, the molded material is taken out from the lower mold 32 by the knockout pin 33. Note that forging is preferably performed after applying a lubricant to the inner periphery of the mold.
The forging material 39 is preferably subjected to a lubricant treatment as necessary. Further, since the gas vent passage 34 is provided, the gas vent passage 34 also functions as a lubricant vent. Therefore, even if the degassing passage 34 is installed at a place where there is a concern of the occurrence of seizure or lack of lubrication residue, synergistic effects are obtained.
<Features of molded products>
Further, when the forging die of the present invention is used for forging, the shape of the air pin 40 to be formed is thin and short. For this reason, when it removes in a post-processing process, the incidence rate of inferior goods can be reduced. In addition, the number of removal work steps can be reduced.
Hereinafter, although a specific example is shown and the effect of this invention is clarified, this invention is not limited to this.
It is an example which manufactured the molded article which has the shape of the rib 11 of FIG. 1 using the die for forging which concerns on this invention. Further, as the gas vent passage 34, the one shown in FIGS. 5 (A) and 5 (B) was used.
As shown in Table 1, the forging material lubrication treatment, the mold lubricant, the mold temperature, and the forging material temperature are not lubricated as shown in Table 1. The mold lubricant is an oil-based lubricant. The mold temperature was 180 ° C. and the temperature of the forging material was 410 ° C. Moreover, 4000 series AL alloy was used for the forging material.

The forging results are shown in Table 2.
As apparent from Table 2, in Example 1, the load 280t, the diameter of the first step portion X is φ0.3 mm, the length of the first step portion X is 5.0 mm, and the diameter of the second step portion Y is φ1. 0.0 mm, angle of connection Z 90 degrees, air pin length 1.5 mm, no clogging phenomenon.
In Example 2, the load is 280 t, the diameter of the first step portion X is φ0.5 mm, the length of the first step portion X is 5.0 mm, the diameter of the second step portion Y is φ1.0 mm, and the angle of the connection portion Z It was 90 degrees, the air pin length was 3.0 mm, and there was no clogging phenomenon.
In Example 3, the load is 280 t, the diameter of the first step portion X is φ0.5 mm, the length of the first step portion X is 12.0 mm, the diameter of the second step portion Y is φ1.0 mm, and the angle of the connection portion Z At 90 degrees, the air pin length was 3 mm and was not eliminated in the forging process immediately after clogging, but was eliminated in the next forging process.
In Comparative Example 1 (conventional), the load is 280 t, the diameter of the first step portion X is φ0.5 mm, the diameter of the second step portion Y is φ0.5 mm (no step portion), and the angle of the connection portion Z There was a clogging phenomenon at 0 degree, an air pin length of 3 mm.
In Comparative Example 2 (conventional), the load 280t, the diameter of the first step portion X is φ1.1 mm, the diameter of the second step portion Y is φ1.1 mm (no step portion), and the angle of the connection portion Z It was 0 degree, the air pin length was 14 mm, and there was no clogging phenomenon. However, the air pins were long and defective products were generated in the next trimming process.

FIG. 13 shows a second embodiment of a forging die for forging a metal material and a forged molded product. Like the die shown in FIG. 4, the die 30 is composed of a lower die 31 and an upper die. 32 and a knockout pin 33 for taking out the molded product from the lower mold 31 or a gas vent passage 34. The lower mold 31 and the upper mold 32 are each provided with a forging hole 35 at the center.
This forging die is preferably used for forming a scroll body of a scroll compressor comprising a base plated surface 13 and a blade portion 14 as shown in FIG.
In forming the spiral body, after the base plate surface 13 having the convex portions 12 is formed, the material is plastically flowed to the blade portions 14 to complete the forming. Gas is confined in the site | part at the time of shaping | molding of this convex part 12. FIG. The gas vent passage is preferably provided at a location where the gas is confined. As a result, it is possible to suppress the occurrence of thinning due to trapped air.
Therefore, in the present embodiment, the gas vent passage 34 is installed at a position corresponding to the convex portion 12, which is a portion where the gas is confined.
FIG. 14 shows a third embodiment of the forging die according to the present invention. Like the die shown in FIG. 13, the die 30 of this embodiment is provided with a gas vent passage 34 in the lower die 31. ing.
The forging die 30 is preferably used for molding a piston of an internal combustion engine having a head surface 15, a skirt portion 16, a rib portion 17, and a pin boss portion 18 as shown in FIG.
FIG. 15 is an enlarged cross-sectional view of an air reservoir portion at the time of molding in the vicinity of the gas vent passage in the rib portion 17 and the skirt portion 16 of the piston of the internal combustion engine, and schematically shows how the air reservoir is generated. It is what I did.
The molding of the internal combustion engine piston is completed after the head surface 15 is molded and the material flows plastically to the rib portion 17, the skirt portion 16 and the pin boss portion 18. It is preferable to provide the gas vent passage 34 at a location where molding is finally performed in the molding order. As a result, it is possible to suppress the occurrence of thinning due to trapped air.
Therefore, in the present embodiment, the gas vent passage 34 is a portion that is finally molded. It is installed on the rib, skirt and pin boss.

  As described above, the forged molded product according to the present invention suppresses the occurrence of thinning due to air trapped in the molding hole of the mold even if it has a complicated shape, and the forging material is sufficiently contained in the molding hole. A molded product with good dimensional accuracy can be obtained.

Claims (10)

In the forging die 30 having the gas vent passage 34 for discharging the gas confined in the molding hole of the forging die at the time of molding,
The gas vent passage has a plurality of step portions having different cross-sectional areas in the direction perpendicular to the gas flow direction, and an opening area of the first step portion facing the forming hole wall surface is connected to the opening of the second step portion. A forging die characterized in that it is smaller than a part area and the opening is provided on a wall surface made of a mold dividing portion or a wall surface made of an integral mold portion. Forging die ranging first claim of claim sectional area of the opening formed in the molded hole wall is 0.01 to 1 mm ^2. The forging die according to claim 1 or 2, wherein a diameter of an inscribed circle having a cross-sectional shape of the opening formed in the wall surface of the molding hole is 0.1 to 1 mm. The area after the next step of the degassing passage of the opening formed in the wall surface of the molding hole is 1.04 times or more of the area on the opening side. The die for forging as described in the item. The length of the shape part by the side of the opening formed in the said shaping | molding hole wall surface is 1-15 times the area value by the side of an opening, The range of any one of Claims 1-5 Die for forging. The opening according to any one of claims 1 to 5, wherein the opening is provided at a position where a gas pool confined in a recess and / or a groove formed by a mold wall surface and a material of the molding hole is generated. The die for forging as described in the item. The forging die according to any one of claims 1 to 6 is used, a forging material is introduced into the forming hole, and a gas confined in the concave portion and / or groove portion of the forming hole is generated. A manufacturing method of a molded product forged while letting it escape through a gas vent passage. The forging material according to claim 7, wherein the forging material is any one metal selected from aluminum, iron, magnesium, and titanium, or an alloy mainly composed of these metals. Production method. A forged product manufactured by the method according to claim 7. A forging device having the forging die according to any one of claims 1 to 6.

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