JP2002361354A - Closed forging method, shaped material of upper arm and lower arm, yoke, die, and closed forging production system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a closed forging method, enhanced in mechanical characteristic, free of deburring traces in a forged product, and suitable for enhancing yield of the product against a forging material. SOLUTION: A cylindrical ingot, having the same volume as that of a forging product, having a shape wherein the ratio of a minor axis length of a plane of projection orthogonal to the pressurizing direction to the length in the pressurizing direction is 1 or less, and composed of an upper bottom face, a lower bottom face and a side face whose shape do not contain an angle, is used as a forging material, and is pressurized from the side face of the forging material 15 to obtain an upper arm or a lower arm being a suspension part for a vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed forging method, a crude material or a yoke of a vehicle suspension component manufactured by the closed forging method, a die used in the closed forging method, and a forging production system by the closed forging method. .

[0002]

2. Description of the Related Art A plurality of branches 21, 22, 23 shown in FIG.
Is used as one of the joint parts used for the vehicle suspension.

Conventionally, as shown in FIG. 3, the yoke 43 is formed by a so-called burr-forging method in which a burr 32 is forged by using a solid round bar 31 as a forging material and forging a burr 32 on the outside of a forged product. .

As another method, as shown in FIG. 4, a material is extruded so as to have a sectional shape substantially similar to that of a product, and cut into a material 41, and a protruding portion 42 of the material 41 is further mechanically cut. It was processed to finish the yoke 43.

On the other hand, recently, as a suspension component for a vehicle, an aluminum alloy is increasingly used instead of a conventional iron material for the purpose of weight reduction. In particular, in order to improve mechanical strength and reduce the amount of materials used in products, these vehicle suspension parts are manufactured by forging. For example, it has been used as one of components constituting a suspension and an upper arm and a lower arm used for a vehicle suspension.

Conventionally, the upper arm 54, which is a vehicle suspension component shown in FIG. 5, has branch-like portions 51, 52, 53 in three directions, for example, so that it is difficult to manufacture it by a single forging process. For this purpose, first, a rough shaped material 61 having a shape close to that of the final product as shown in FIG. 6 is manufactured by forging, and the upper arm 54 shown in FIG. 5 is manufactured through a plurality of forging steps.

More specifically, for example, a solid round bar 7 shown in FIG.
1 to forging with a rough material forging die, burr 72 is deburred from a forged product having a burr 72 on the outside by a trim die, and the obtained rough material 73 is forged a plurality of times to form an upper arm 74. Have gained. Here, in order to reduce material loss due to the burrs 72, the rough-form material forging die is formed into a shape such that a plurality of forged products 73a can be obtained at once from one solid round bar material 71. ing.

On the other hand, as a method of forging a simple circular product 81 such as a VTR cylinder shown in FIG. 8 from a disk-shaped material 82, a closed forging method that does not produce burrs is known. As a method of manufacturing a product having a plurality of branch-shaped portions using the closed forging method, a method disclosed in Japanese Patent Application Laid-Open No. 1-166842 is known. As shown in FIG. 9, the disclosed method is a method of forging a product having a plurality of branch portions in a radial direction, using a solid round bar as a raw material, and adding a solid round bar by a punch 91. This is a method of extruding into the impressions in dies 93 and 94 while applying pressure, and forming a radially-spread branched branch portion 92 by closed forging.

[0009]

In the above-described conventional manufacturing method for manufacturing a yoke, for example, in the deburring forging shown in FIG. 3, a trimming step of removing burrs after forging is required, and a burr portion is unnecessary. Therefore, the yield of the forged product with respect to the forging material was low. Further, since the projected area of the forged product in the pressing direction is large, a large and expensive forging machine having a large pressing force is required, and the production cost is increased.

[0010] Further, a material obtained by cutting the extruded product is used as a material.
In the method of FIG. 4 in which the yoke is manufactured by finishing by cutting, the protruding portion 42 is formed by cutting, so that the amount of cutting is increased, and as a result, the product yield for the material 41 is poor, and Work man-hours are required, and the production cost increases.

[0011] On the other hand, a conventional method for manufacturing a vehicle suspension component, that is, an upper arm or a lower arm coarse material,
A trim step for removing burrs is required in a later step, and the burr portion is unnecessary, so that the product yield of the upper arm and lower arm coarse material obtained for the material is poor. Also, because the projected area of the forged product in the pressing direction is large,
Since a large and expensive forging machine having a large pressing force is required, the production cost increases.

In the closed forging method described in the above-mentioned Japanese Patent Application Laid-Open No. 1-166842, a cylindrical material is pressed against a radially expanding branch-like branch portion 92 (FIG. 9) from the direction of the cut surface. Since it is assumed that the material is caused to plastically flow, if the branch portion 92 is long or the shape of the branch portion 92 is different, the thickness and thickness of the material due to the plastic flow speed and direction of the material differ at each part of the forged product. There is a possibility that forging defects such as fogging and the like generated on the surface of the forged product may occur.

The present invention has been made in view of such a situation, and in a closed forging method for manufacturing a member having a plurality of branches, the pressing force at the time of forging is reduced to improve the product yield with respect to the material. It is an object of the present invention to provide a forging method, a mold used in the above method, and a production system using the mold. It is another object of the present invention to provide a method for efficiently and inexpensively manufacturing a vehicle suspension component and its rough shape or yoke. Still another object of the present invention is to provide a forged product having increased mechanical strength by plastically flowing a material for forging along a plurality of branches of the product to form a layered metal flow at the branches of the forged product. Is to provide.

As used herein, the term "raw material" means an article that has never been forged, and includes an ingot, a forging material, a cut product, a solid round bar, a material, a solid round bar, and a medium. Includes solid round bar material, columnar material, round bar material, continuous cast round bar, disk, billet material. As used herein, the term “rough material” refers to a product obtained by a forging process, but a product requiring one or more forging processes to obtain a final product. Includes rough materials for forging and rough materials. In this specification, "forged product" means a product obtained through a forging process,
Includes components, products, finished products, forged products, and forged products.

[0015]

SUMMARY OF THE INVENTION The present invention relates to a closed forging method for manufacturing a forged product, wherein a short axis length of a projection plane having a volume equal to the volume of the forged product and perpendicular to the pressing direction and a pressing direction are provided. Having a shape whose ratio to the length is 1 or less, using a cylindrical ingot composed of upper and lower bottom surfaces having no corners and side surfaces as a material for forging, From the side. The columnar material has a value of a ratio (T / R) of a diameter (R) to a thickness (T) of 1 or less and has the same volume as the volume (V) of the forged product. Includes a column-shaped cut product that has been cut as described above. The closed forging method includes a volume (V) of a forged product, a thickness (T) of a cylindrical material, a long axis length (L) of a projected area of the forged product in a pressing direction, and a length of a cylindrical material. The relationship with the diameter (R) is

(Equation 2) Including that The thickness (T) of the columnar material is 0.8 to 1.0 × (the short axis length (t) of the projected area in the pressing direction of the forged product). The material for forging includes being aluminum or an aluminum alloy. Further, the forged product is a member having a plurality of branches in which a forging line flows along the branch and having no deburring marks, and the member is a vehicle suspension part upper or lower arm coarse material. Alternatively, it includes a yoke which is a joint part used for a vehicle suspension. The forging die used in the closed forging method of the present invention includes a punch and a die and a knock or a punch and a die having an operating mechanism. Further, in a closed forging production system including a material cutting device according to the present invention and a forging machine, the forging machine includes a die including a punch, a die and a knock, or a die including a punch and a die including an operating mechanism. Including having.

In the closed forging method according to the present invention, as described above, the ratio between the short axis length of the projection plane perpendicular to the pressing direction and the length in the pressing direction is the same as the volume of the forged product. A columnar material having a shape of 1 or less and having no corners is used, and pressure is applied from the side of the columnar material, so that the columnar material is plastically layered on a plurality of branches of the forged product. To flow,
The mechanical properties of the forged product are improved, the forged product has no deburring marks, and the yield of the product on a cylindrical material is improved. Further, a coarse material of an upper arm or a lower arm, which is a vehicle suspension component manufactured by the closed forging method, or a yoke, which is a joint component used for a vehicle suspension, has a columnar material made of a plurality of forged products. Plastic flow in a laminar manner at the branch portions of the, improving the mechanical properties. The mold used in the closed forging method has a shape of a space surrounded by a punch, a die, a knock and / or a bush, or a shape of a space surrounded by a punch and a die having an operating mechanism, and a volume of a forged product. It has the same volume and has a shape in which the ratio of the short axis length of the projection plane perpendicular to the pressing direction to the length in the pressing direction is 1 or less, and can be pressed from the side of a cylindrical material. Therefore, the pressing force at the time of forging can be reduced, and the yield of the product with respect to the columnar material is improved.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have eagerly studied a closed forging method for manufacturing a forged product, a closed forging production system, an improvement in product yield for a material, and a relationship between a metal flow of a forged product and a mechanical strength of the forged product. After conducting research, the present invention was completed based on the findings. The forging material used in the present invention has the same volume as the volume of the forged product, and has a shape in which the ratio of the short axis length of the projection plane perpendicular to the pressing direction to the length in the pressing direction is 1 or less. , A cylindrical ingot having an upper bottom surface and a lower bottom surface having no corners, and side surfaces. Here, the same volume is at least a volume within a range of dimensional tolerance allowed for a forged product. For example,
It is preferably within 2% of the product volume, more preferably within 1%.

If the volume of the forging material is not the same as the volume of the forged product, for example, if (forging product volume)> (volume of forging material), the forged product will be underfilled, and (forging product volume) In the case of <(volume of the material for forging), burrs are generated on the forged product, so that it cannot be used as it is as a forged product, or the mold is damaged. If burrs occur on the forged product, a process to remove the burrs is necessary,
As the number of working steps increases, the yield of forged products deteriorates. The closed forging method according to the present invention is suitable for producing a member having a plurality of branches. In the present specification, a member having a plurality of branches is defined as a plurality of branch ends (for example, a branch is a portion that is connected to or supported by another component when the member is used). The shape is such that the branches extend from each branch end toward the junction (for example, the center of gravity is included) within the polygonal range with each branch end as the vertex through an arbitrary path from the base, and basically merge. This includes the case where the branch part has a shape and does not have the side branch extending toward the branch part, and the junction of the branch parts extending from the branch end is the other branch end itself. The branches may be provided with punched holes for weight reduction. A member having a plurality of branches is a member having a shape in which a plurality of branches extend from the junction when viewed from the junction.
The present invention is applicable even when the extending branch is symmetric or asymmetric with respect to the junction. For example, a yoke which is a joint part used for a vehicle suspension part,
An upper arm, a lower arm and the like, which are suspension parts for a vehicle, may be mentioned. In these products, the mechanical strength of the branch is required to be improved.

The closed forging method according to the present invention has a shape in which the ratio of the short axis length of the projection plane perpendicular to the pressing direction to the length in the pressing direction is 1 or less, and the upper bottom surface has no corner. And, using the material for forging a cylindrical ingot consisting of the bottom surface and the side,
It consists in pressurizing from the side surface of the said cylindrical forging material. The columnar shape consisting of the upper and lower bottom surfaces having no corners and the side surfaces is, for example, a cylinder in which the shape of the bottom surface is surrounded by a curve having no corners, and the shape of the bottom surface does not include the corners. Examples include a truncated cone, an elliptical cylinder, and an elliptical truncated cone surrounded by a curve. When the ratio of the short axis length of the projection surface perpendicular to the pressing direction of the forging material to the length in the pressing direction exceeds 1, the projection area in the pressing direction increases, and the forging pressure increases. As a result, the forging pressure is increased more than necessary, and the forged state of the forged product may become unstable. The effect is large when forging a coarse material of an upper arm or a lower arm, which is a vehicle suspension part, or a yoke, which is a joint part used for a vehicle suspension. Further, an expensive forging machine having a larger forging pressure is required for forging, and the cost is high, which is not preferable.

In the present invention, since the above-described side surface of the material is pressurized, the plastic flow of the material is such that the metal flow flows in a long axis direction from a portion where the projected area is small.
The strength of the part there can be increased. When the forged product is a member having a plurality of branches, the metal flow of the branches becomes layered along the shape of the branches, and as a result, the strength of the branches can be increased.

In the case where the material for forging is cut from a round bar material into a cut product, the cut surface of the round bar material is not the same as the forging pressure surface, but a surface perpendicular to the cut surface of the round bar material. That is, the side surface of the round bar and the forging pressure surface are made the same.

In the forging method in which the cut surface of the round bar material and the forging pressure surface are the same, the yoke used for the coarse material of the upper arm and the lower arm, which are the suspension parts for the vehicle, and the joint part of the suspension for the vehicle, is used. When such a branch is provided, the forging material plastically flows into the branch while the corner formed by the cut surface and the outer peripheral surface (side surface) of the cut product moves to the branch of the forged product. At this time, the plastic flow speed and plastic flow direction of the material differ depending on each part of the cutting surface and cutting outer peripheral surface,
Forging defects such as fogging caused by the corners will occur on the branch surface of the forged product. As a result, the forging defect may serve as a starting point for fracture of the forged product, so that it cannot be used as a forged product requiring higher quality characteristics.

In the present invention, since the forging material is a cylindrical ingot having no corners and the pressure is applied from the side surface of the forging material, the above-mentioned corners are formed in the forged product. Since the material is plastically flowed so as to coincide with the contour of the outer periphery, it is possible to suppress the occurrence of forging defects such as fogging on the branches of the forged product. Further, since the ratio of the short axis length of the projection surface perpendicular to the pressing direction to the length in the pressing direction is 1 or less, the projected area of the forged product in the pressing direction is reduced, and the pressing load can be reduced.

When a cut product of a round bar is pressed from the side surface of the cylindrical forging material from the outer peripheral surface perpendicular to the cut surface, the corners as described above correspond to the contour of the outer periphery of the forged product. The material is plastically flowed so as to coincide with each other, so that it is possible to suppress the occurrence of forging defects such as fogging on the branches of the forged product, which is preferable. Further, since the ratio of the thickness of the cut product to the diameter of the cut product obtained by cutting the round bar material is 1 or less, the projected area of the forged product in the pressing direction can be reduced, and the pressing load can be reduced. .

In the manufacturing method according to the present invention, the contour of the upper bottom surface and / or the lower bottom surface of the forging material need only be smooth without including corners. For example, a circle, a vertically long ellipse, a horizontally long ellipse, or a polygonal shape having corners with smooth connections is more preferable because forging defects such as fogging do not occur.

In the forging material used in the present invention, the ratio of the round bar (R) [mm] to the thickness (T) [mm] (T
/ R) is 1 or less (preferably (π / 4) or less, more preferably 0.5 or less). A cylindrical cut product is cut in cost and ease of material processing. Preferred from the point.

In the casting method according to the present invention, a metal material can be used as the material of the forged material. For example, aluminum, iron, magnesium, and alloys containing these as main components can be given. If it is an aluminum alloy, an Al-Mg-Si alloy, an Al-Cu alloy,
Al-Si alloys and the like can be mentioned. Al-
As the Mg-Si alloy, JIS6061 alloy, SU
610 alloy. In addition, JIS2024 alloy, 2014 alloy and the like can be used as long as it is an Al-Cu alloy. JIS for Al-Si alloys
4032 alloy and the like.

The material used in the present invention may be manufactured by any method such as a continuous casting method, an extrusion method, and a rolling method. In the case of aluminum or an aluminum alloy, a continuously formed round bar is preferably used at a low cost. In the case of aluminum alloys, a gas pressurized hot-top casting method (for example, SHOT
A round bar continuously cast with (IC material) is more preferable because it has excellent internal soundness, has fine crystal grains, and has no crystal grain anisotropy due to plastic working. This is because in the forging method of the present invention, the forged material is plastically flowed evenly in a layered manner at the forged product branch portion, forging defects such as underfill are not generated, and it is more preferable in terms of improving the mechanical strength of the product. .

The method of manufacturing the raw material used in the present invention is as follows: the volume of the forged product (V) [mm ³ ] and the thickness of the round bar (T) [m
m], the major axis length (L) [mm] of the projected area of the forged product in the pressing direction, and the diameter (R) [mm] of the round bar are:

(Equation 3) It is preferable that

The diameter (R) of the round bar cut product is

(Equation 4) In the case of, a large forcing force greater than the pressing ability is required to plastically flow the material to the forged product branch in one forging, so multiple forging processes are necessary, and the desired forging due to insufficient pressurization The product may not be obtained and the forged product may be underfilled. Also, in this case, it means that the plastic flow distance of the material becomes longer, and in this case, the lubrication film breaks between the forged material and the mold, and the forging such as seizure or galling occurs on the forged product. Defects may occur and require machining to remove forging defects. When the major axis length L is smaller than the diameter R, the following expression is obtained.

(Equation 5) Since a round bar cut product cannot be put into a forging die, closed forging cannot be performed.

The material for forging used in the present invention has a round bar material thickness (T) [mm] of 0.8 to 1.0 × (the short axis length (t) of the projected area of the forged product in the pressing direction). [Mm]). When the thickness of the round bar cut product is 0.8 × t or more, the forging material does not tilt in the mold,
Since the forging material input position into the mold is more stable than the inside of the mold, forging defects such as underfill, uneven thickness, and fogging do not occur during forging, and a forged product with stable quality can be manufactured. Further, when the thickness of the round bar cut product exceeds 1.0 × t, the forging material cannot be put into the forging die, so that closed forging without generating burrs cannot be performed.

The manufacturing method of the present invention has a shape having the same volume as the volume of the forged product, wherein the ratio of the short axis length of the projection plane perpendicular to the pressing direction to the length in the pressing direction is 1 or less. Then, the closed forging method in which the cylindrical ingot composed of the upper bottom surface and the lower bottom surface having no corners and the side surfaces is used as a forging material, and pressure is applied from the side surface of the cylindrical forging material, The pressing force at the time can be reduced, the product yield with respect to the forging material is excellent, and the mechanical strength of the forged product is improved.

In the method of the present invention, by applying a pressure from the side of the cylindrical forging material, a rough shaped material for forging of an upper arm or a lower arm, which is a suspension part for a vehicle, can be manufactured. This is a manufacturing method in which the pressing force of the forging can be reduced and the product yield for the forging material is excellent. Furthermore, the forged raw material of the upper arm and the lower arm, which are suspension parts for vehicles manufactured by this method, is subjected to plastic flow along the plurality of branches of the forged product, thereby forming the forged product branches. Since the metal flow becomes layered along the product shape, as a result, mechanical strength is improved, which is more preferable. In the present specification, a metal flow is a flow of crystal grains of a forged product formed by forging which is a plastic working. The layered metal flow indicates that the flow of crystal grains is uniform along the shape of the forged product, and the observed striped flow follows the shape of the forged product and goes out of the surface. It is not interrupted or disturbed inside the forged product. Such a state is said that the forging line flows along the forged product branch.
In aluminum alloys such as JIS2014 and JIS6061, mechanical strength increases as the amount of plastic flow increases, but when excessive plastic flow is added, coarsening of crystal grains occurs in a part of the forged product. . Due to the coarsening of the crystal grains, the mechanical strength is greatly reduced. In the conventional deburring forging method, the amount of plastic flow near the parting line is large. Therefore, in the conventional manufacturing method, the crystal grains become coarse near the parting line, and the mechanical strength is reduced. However, since the method of the present invention does not generate burrs, there is no parting line. Therefore, the method of the present invention is superior to the conventional method in that the coarsening of crystal grains can be suppressed and a local decrease in strength does not occur.

As described above, burrs do not occur in the forged rough parts of the upper arm and the lower arm, which are the vehicle suspension parts manufactured by the method of the present invention, and as a result, the coarse parts have no deburring marks. It is more preferable from the viewpoint of improving product yield.

In the method of the present invention, a yoke, which is a joint part used for a vehicle suspension part, can be manufactured by applying pressure from a side surface of a cylindrical forging material. This is a manufacturing method that can be reduced and has an excellent product yield for forging materials.
Further, the yoke, which is a vehicle suspension part manufactured by this method, has a metal flow in a product branch portion which becomes laminar because the forging material plastically flows along the plurality of such branch portions of the product. As a result, it is preferable from the viewpoint of improving mechanical strength.

The yoke, which is a vehicle suspension component manufactured by this method, does not generate burrs, and as a result, there is no burring mark on the forged product, and it is preferable from the viewpoint of improving the product yield.

Next, a closed forging production system used in the closed forging method according to the present invention will be described. FIG. 10 schematically shows an example of a configuration example of a closed forging production system including the above closed forging method.

Referring to FIG. 10, the closed forging production system includes a material cutting device 101 and a forging machine 105. In the case of hot forging in which the material is heated and then forged, it is necessary to include the material heating device 103. Further, the material supply device 102 and the material transfer device 10
4 and the forged product unloading device 106, it is configured as an integrated automatic production system. When the forged product has the shape of the final product, it is preferable to include the forged product heat treatment furnace 107.

The material cutting device 101 is for cutting a continuously cast round bar into the same length as a forged product. The material supply device 102 is for holding a certain amount of forging material in a hopper and supplying the forging material to the next step. The material transfer device 104 is for transferring a forging material to a mold. The forging machine 105 is for forging a material for forging. The forged product carry-out device 106 is for discharging the forged product from the inside of the mold by a knockout mechanism and transporting it to the next process. Alternatively, it is also used when the forged product in the split die is taken out of the mold and transported to the next step. The material heating device 103 is for heating the forging material to enhance forging workability. The forged product heat treatment furnace 107 is used for heat treatment for continuously performing solution treatment and aging treatment on the taken out forged product.

An example of the configuration of a forging die attached to the forging machine of the present invention will be schematically described with reference to FIG.

The forging die of the present invention includes a punch 111, a die 112, a bush 113, and a knock 114. Further, if necessary, for example, in the case of hot forging in which forging is performed after heating the forging material, it is preferable to attach a lubricant spraying device 115 to the die to the forging die or forging machine. Also, the lubricant spray device 115
May be installed as a single lubricating device and its operation may be linked with the forging machine.

Here, in the mold of the present invention, the shape of the space surrounded by the punch, the die, the knock and / or the bush is the same as the volume of the forged product, and is perpendicular to the pressing direction. The ratio of the short axis length to the length in the pressing direction is 1 or less, and the forging material is a column-shaped ingot composed of the upper and lower bottom surfaces having no corners and the side surfaces. ,
The forging material can be installed so that pressure can be applied from the side surface of the columnar forging material.

In the mold of the present invention, the shape of the space surrounded by the punch, the die, the knock and / or the bush is a shape for closing and manufacturing a member having a plurality of branches.
The value of the ratio (T / R) of the diameter (R) [mm] to the thickness (T) [mm] of the round bar material is 1 or less, and the volume (V) [mm ³ ] of the forged product. A cylindrical cut product cut to have the same volume is used as a forging material, and the forging material can be installed so that pressure can be applied from the side surface of the cylindrical forging material.

In particular, it is preferable from the viewpoint of metal flow that the forging material can be installed in contact with the vicinity of the junction of the branches in the space.

The mold of the present invention has a volume (V) of a forged product.
[Mm ³ ], the thickness of the round bar (T) [mm], and the major axis length (L) [m] of the projected area of the forged product in the pressing direction.
m] and the diameter (R) [mm] of the round bar are

(Equation 6) It is preferable to have a shape of a space surrounded by a punch, a die, a knock and / or a bush.

The mold of the present invention has a thickness (T) [m
m] is 0.8 to 1.0 × (the short axis length (t) [mm] of the projected area in the pressing direction of the forged product) [mm], and is a space surrounded by punches, dies, knocks, and / or bushes. It is preferable to have the following shape.

The closed forging production system of the present invention comprises a punch,
The shape of the space surrounded by the dies, knocks and / or bushes has the same volume as the volume of the forged product, and the ratio of the short axis length of the projection plane perpendicular to the pressing direction to the length in the pressing direction is 1
It has the following shape, the upper and lower bottom surfaces having no corners, and a cylindrical ingot composed of side surfaces is used as a forging material, and can be pressed from the side surface of the cylindrical forging material. Has a mold capable of setting a forging material in the mold.

According to the closed forging production system of the present invention, the shape of the space surrounded by the punch, the die, the knock and / or the bush is a shape for closing and manufacturing a member having a plurality of branches. The value of the ratio (T / R) of the diameter (R) [mm] to the thickness (T) [mm] is 1 or less and the same volume as the volume (V) [mm ³ ] of the forged product The forging material is a columnar cut product cut in such a manner that a forging material can be installed so that pressure can be applied from the side surface of the columnar forging material. Is preferred.

In the configuration of the die for forging in the closed forging production system of the present invention, the combination of the die, the bush, and the knock has one component, and
It may be an integrated mold composed of only dies. Alternatively, a combination of two or more component parts may be combined into one component, for example, a split mold in which a plurality of bushes are incorporated in a die. From the viewpoint of improving the mold life, a split mold is more preferable.

In the mold of the present invention, the shape of the space surrounded by the punch, the die, the knock and / or the bush is the same as the volume of the forged product, and the short axis of the projection surface perpendicular to the pressing direction. The forging material is a column-shaped ingot having a shape in which the ratio of the length to the length in the pressing direction is 1 or less, the upper and lower bottom surfaces having no corners, and the side surface. Since the forging material can be installed so that pressure can be applied from the side of the columnar forging material, the pressing force during forging can be reduced, and the product yield for the forging material is excellent, It has the effect of improving mechanical strength.

Next, an embodiment of the manufacturing method of the present invention using the closed forging production system of FIG. 10 and the mold of FIG. 11 will be described.

The closed forging method according to the present invention comprises: 1) a step of cutting a continuous cast round bar into the same volume as a forged product; and 2) holding a fixed amount of forging material in a hopper and proceeding to the next step. Supplying a forging material; 3) transporting the forging material to a die; 4) forging the forging material; and 5) discharging the forged product from the die by a knockout mechanism. And 6) a heat treatment step of continuously performing solution treatment and aging treatment on the taken out forged product.

Further, in the case of cold forging in which the shape of a forged product is easy and the forging material is forged at room temperature, a bond treatment for subjecting the forging material to a chemical conversion treatment before forging may be performed if necessary. Adding a step to be performed reduces forging load,
It is preferable from the viewpoint of preventing seizure between the forged product and the mold.

In the case of hot forging, in which the forged product is complicated in shape and the forging material is heated and then forged, if necessary, a step of preheating the forging material is performed. For example, a step of subjecting a forging material to a water-soluble graphite lubrication treatment, a step of preheating a closed forging die to a predetermined temperature, a method of dissolving water in a closed forging die, for example, a forging portion of the closed forging die. Spraying a graphite graphite lubricant, or adding a process selected from the step of spraying an oily lubricant to the forging part of a closed forging die reduces the forging load, or a forged product From the viewpoint of preventing seizure between the mold and the mold.

FIG. 12 schematically shows an example of a configuration in which a split die having an operating mechanism is used as the die for the closed forging die. In FIG. 12, a pair of split dies 1
Reference numeral 21 is arranged at a predetermined interval so that the surface on which the forged product molded portion is carved faces each other. An arm 122 is provided on the back surface of each split die 121,
A drive mechanism (not shown) such as a hydraulic cylinder or an electric motor is connected to the other end of the arm section 122 via a power transmission mechanism. During forging, the pair of split dies 121 advance forward with each other by the drive mechanism. To form a mold for closed forging. After the forging is completed, the driving mechanism is driven in the opposite direction to open the split dies 121 to take out the product. The position of the arm 122 provided on the back surface of the split die 121 is preferably at the back surface where the branch portions of the mold are gathered because an unbalanced load is not applied. When forging products with precise dimensions, 1
A plurality of arm parts 122 are provided at necessary places for each of the divided dies 121 to form a mold. In the embodiment of FIG. 12, the operating mechanism is provided for both of the divided dies. However, one of the divided dies may be fixed, and the operating mechanism may be provided only for the other of the divided dies, and the forging may be performed by operating. As described above, by using the split die, in addition to the effect obtained by the closed forging die, the product can be discharged not only in the upward direction of the split die but also in the opening direction of the split die. Therefore, the product can be taken out of the mold regardless of the knockout stroke. In particular, it is possible to forge a product having an undercut shape, which cannot be obtained with the closed forging die. Note that the undercut shape is a shape in which a forged product cannot be taken out of a mold even if a knockout mechanism is used. Furthermore, since the mold is divided, it is easy to spray the lubricating oil over the entire mold, and the maintainability of the die surface is improved.

According to the closed forging production system of the present invention, the shape of the space surrounded by the punch, the die, the knock and / or the bush is the same as the volume of the forged product and the projection surface perpendicular to the pressing direction is formed. The forging material is a column-shaped ingot having a shape in which the ratio of the short axis length to the length in the pressing direction is 1 or less, the upper and lower bottom surfaces having no corners, and the side surfaces. Since it has a mold capable of setting the forging material so that it can be pressed from the side of the cylindrical forging material, the pressing force at the time of forging can be reduced, and the product for the forging material can be reduced. It has excellent yield and has the effect of improving the mechanical strength of forged products.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Embodiment 1 Since a yoke 43 as a joint part used in the vehicle suspension shown in FIG. 2 is forged and manufactured, a JIS 6 having the same volume as the yoke 43 is used.
The cut product of the 061 aluminum alloy was designed as a forging material as follows.

First, the product volume of the yoke 43 was calculated by a CAD system using a computer. From the calculation results, the volume of the cut product was set to 38.8 [cm ³ ], and a cutting error range of ± 1% with respect to the calculated product volume was set as the cutting tolerance.

Next, as shown in FIG. 13, the length of the short axis length t, which is perpendicular to the pressing direction A of the forged product shown in FIG.
The thickness (T) of the cut product material is 34 [mm], which is 95 times, and the diameter (R) of the cut product of the round bar is calculated from the volume of the cut product and the thickness of the cut product.

(Equation 7) And Where R is

(Equation 8) Meets. In FIG. 13, reference numeral 131 denotes a punch, 1
32 is a die, 133 is a knock, 134 is a knockout, and 135 is a yoke as a forged product.

Based on this design, a continuous cast round bar (diameter 38.1) of an aluminum alloy specified in JIS6061
[Mm]), the diameter is 38.1 [mm] and the thickness is 34 [m
m] and a disk-shaped cut product having a volume of 38.8 [cm ³ ]
I cut it out. The weight of a disk-shaped cut product is 1
The average value of 0 samples was 104.8 [g].

The disk-shaped cut product 151 was subjected to a conventionally known bonding process, and was placed at a mold position as shown in FIG. Next, cold forging was performed by applying a weight from an outer peripheral surface of the disk with a punch under normal temperature conditions. Forging equipment is AIDA 4
A 00t press was used. The average value of the forging pressure at this time was 1372 [kN]. The weight of the forged product is
The average value of the 10 forged products is 104 [g], and the long axis length L of the projection surface of the obtained forged product in the pressing direction indicated by the symbol C in FIG. 14 is 51 [mm] on average. there were.

As a result of performing forging under the above conditions, no seizure or the like was observed in the forged product, and no problem such as a sudden increase in forging load occurred.

As a result of visually inspecting the appearance of the forged product for quality confirmation, the rate of occurrence of forging defects such as seizure and fogging is (number of occurrences / number of samples) = (0/10). The occurrence rate of forging defects was 0%. Since no seizure occurred, the plastic flow resistance of the material did not increase, and no sharp increase in forging pressure occurred. Since there is no sharp rise in the forging pressure, it is expected that the life of the forging die can be extended. The yield of the product weight relative to the material weight of the forged product was about 99%.

[Comparative Example 1] A yoke 43 as a joint part used in the vehicle suspension shown in FIG. 2 was manufactured by burr removal hot forging, which is a conventional manufacturing method.

The material for forging has a diameter of 40.6 [m] from the JIS6061 continuous cast round bar diameter (40.6 [mm]).
m], a thickness of 50 [mm], and a volume of 65 [cm ³ ]. The weight of the disc-shaped cut product had an average value of 175 [g] for 10 cut products.

The surface of the disk-shaped cut product 161 was coated with a conventionally known water-soluble graphite lubricant, and was placed at a die (die 163, punch 162) as shown in FIG. Next, as a hot flashing forging condition, the forging material was heated to 420 ° C., and the mold was pre-heated to 200 ° C.
A water-soluble graphite lubricant was sprayed on the forging die. Thereafter, hot forging was performed by applying a load from the outer peripheral surface of the disk with a punch. As the forging device, a 400 t press manufactured by AIDA was used. The average value of the forging pressure at this time is 2940 [k]
N]. After forging, using a trim mold, deburring was performed and the shape was adjusted to obtain a product. As for the weight of the forged product, the average value of 10 forged products was 104 [g], and the yield of the product weight to the material weight of the forged product was about 59%.

[Strength Test, Metal Flow Observation] Forged product obtained by closed forging according to the present invention (Example 1)
Heat treatment is performed on the forged product (Comparative Example 1) obtained by the conventional hot forging with deburring under a solution manufacturing condition (solution maintained at 510 ° C. for 6 hours) and aging condition (maintained at 170 ° C. for 6 hours). After that, a tensile test piece ASTM-R5 (width 2.87 mm, gauge length 11.5 mm) shown in FIG. 17 was cut out from the portion indicated by the symbol P in FIG. 2 in parallel with the branch of the product.
The mechanical properties were measured. The tensile tester was an autograph manufactured by Shimadzu Corporation under the condition of a tensile load of 5 [kN]. The measurement was performed for each of the 10 forged products of the example and the 10 forged products of the comparative example, and the data of the mechanical properties obtained at this time are shown in Table 1 for Example 1 and Comparative Example 1
Are shown in Table 2.

[0069]

[Table 1]

[0070]

[Table 2]

From the results shown in Tables 1 and 2, the forged product obtained by the closed forging according to the present invention has a higher tensile strength and a lower forging product than the forged product obtained by the burr forming hot forging which is a conventional manufacturing method.
It can be seen that the numerical value of 0.2% proof stress is about 10% higher and the mechanical properties are higher.

Next, in order to observe the metal flow at the branches of the obtained forged product, a material for observing the metal flow was cut out from the forged product, and the observation surface of the metal flow was polished with emery paper to obtain a 20% concentration. The sample was immersed in a caustic soda solution for 30 seconds and subjected to an etching treatment to prepare a sample. The metal flow was confirmed by visual observation of the macrostructure. As a result, in the forged product obtained according to the present invention, since the cut surface of the forging material and the corners of the outer peripheral surface thereof coincided with the outer peripheral contour of the forged product, no defects such as fogging were observed. Was. In addition, a uniform flow pattern was observed along a plurality of branches of the forged product, and a layered metal flow that was not interrupted or disturbed was observed. This indicates that the forging material is in a layered plastic flow along the branches of the forged product. On the other hand, as a result of observing the macrostructure of the forged product obtained by the conventional method of burr removal hot forging under the above conditions, metal flows completely unrelated to a plurality of branch directions were observed.

Further, since the forged product obtained by the closed forging method according to the present invention does not have a trimming step (also called a deburring step), there is no deburring mark on the forged product.
It shows an improvement in product yield for forging materials. On the other hand, a forged product obtained by the conventional method of deburring hot forging requires trimming of the burr on the outside of the product, so that a trimming step is required, and the forged product has deburring marks.

Embodiment 2 In order to forge a joint part yoke used in the vehicle suspension shown in FIG. 18, a cut product of JIS6061 aluminum alloy having the same volume as this yoke is designed as a forging material as follows. did.

First, the product volume of the yoke was calculated by a CAD system using a computer. From the calculation results, the volume of the cut product was set to 84.0 [cm ³ ], and a cutting error range of ± 1% with respect to the calculated product volume was set as the cutting tolerance.

Next, as shown in FIG. 19, perpendicular to the pressing direction D of the forged product shown in FIG.
The thickness of the cut product material is 30 [mm], which is 95 times, and the diameter (R) of the cut product of the round bar is calculated from the volume of the cut product and the thickness of the cut product.

(Equation 9) And Where R is

(Equation 10) Does not satisfy

[Equation 11] It has become. In FIG. 19, reference numeral 191 denotes a punch;
2 is a die, 193 is a knock, 194 is a knockout,
195 is a yoke as a forged product.

Based on this design, a continuously cast round bar (diameter 59.7) of an aluminum alloy specified in JIS6061
[Mm]), the diameter is 59.7 [mm], and the thickness is 30 [m].
m] and a disk-shaped cut product having a volume of 84.0 [cm ³ ].
I cut it out. As for the weight of the disc-shaped cut product, the average value of 10 cut products was 227 [g].

The surface of the disc-shaped cut product 211 was subjected to a conventionally known coating treatment with a bond lubricant, and was placed at a mold position as shown in FIG. Next, cold forging was performed by applying a weight from an outer peripheral surface of the disk with a punch under normal temperature conditions. As the forging device, an 800 t press manufactured by Komatsu was used. The average weight of the forged product was 226.5 [g], and the average value of the major axis length L of the projection surface of the obtained forged product in the pressing direction indicated by the symbol F in FIG. 20 was 200 [mm]. Was.

As a result of macrostructure observation, it was confirmed that the corner between the cut surface and the outer peripheral surface of the forging material was along the outer peripheral contour of the forged product. The metal flowed along the plurality of branches, and it was confirmed that the forged material was plastically flowed in layers on the forged product branches.

When forging is performed under the above conditions, FIG.
The plastic flow distance of the material to the part G shown in Fig. 19 became large. In particular, in the part H shown in Fig. 19, seizure due to the breakage of the lubricating film between the forged product and the mold was observed. The incidence rate is (number of occurrences /
The number of samples) = (8/10), and the incidence was 80%. Since the surface of the forged product suffered from seizure due to the breakage of the lubricating film between the material and the mold, the work of removing the seizure was performed.

Example 3 In Example 1, 25 mm, which is 0.7 times the length indicated by reference numeral B in FIG. 14, is defined as the thickness of the disk-shaped cut product, and the diameter of the cut product from the round bar ( R)
To

(Equation 12) And Other forging conditions were forging under the same conditions as in Example 1. As a result, when forging was performed, the position of the forging material became unstable in the forging die in the forging die, and the forging material was tilted in the forging die. The defect occurrence rate was 50%.

Embodiment 4 In order to forge the upper arm rough ground rough material, which is a suspension part for an automobile shown in FIG. 6, a JIS 6 having the same volume as the upper arm rough ground rough material is used.
A cut product of the 061 aluminum alloy was designed as a forging material as follows.

First, the product volume of the upper arm wasteland rough was calculated by a CAD system using a computer. From the calculation result, the volume of the cut product was 862 [c
m ³ ], and a cutting tolerance range of ± 1% with respect to the calculated product volume was defined as a cutting error.

Next, FIG. 22 perpendicular to the pressing direction I shown in FIG.
28 [mm], which is 0.95 times the length of the minor axis length t indicated by reference symbol J in the middle, is defined as the thickness of the cut product. The diameter (R)

(Equation 13) And Where R is

[Equation 14] Satisfies the conditions.

Based on this design, a continuous cast billet material (diameter 198 [m
m]), the diameter is 198 [mm], the thickness is 28 [mm],
Ten disk-shaped cut products having a volume of 862 [cm ³ ] were cut out. The average weight of the disc-shaped cut product was 2330 [g]. In FIG. 1, 11 is a punch, 12 is a die, 1
Numeral 3 denotes a knock, numeral 14 denotes a knockout, and numeral 15 denotes a forged coarse material of the upper arm.

The surface of the disc-shaped cut product 231 is coated with a conventionally known water-soluble graphite lubricant, and
Spraying a conventionally known water-soluble graphite lubricant onto a forging die, FIG.
3 was placed at the position of the die as shown in FIG. As a forging device, a 3000 t press manufactured by Sumitomo Heavy Industries, Ltd. was used. Forging conditions were hot forging at a material heating temperature of 500 ° C. and a mold temperature of 200 ° C. The average value of the forging pressure at this time was 6370 [k].
N]. The average weight of the product was 2328 [g]. The long axis length L of the projection surface of the forged product in the pressing direction indicated by the symbol K in FIG. 22 was 392 [mm] on average. The yield of the product weight relative to the material weight of the forged product was about 99%.

In the forged product, the metal flows plastically in a plurality of branches in a layered manner, so that the mechanical strength is improved. Further, since the forged product is closed forging, trim marks are not formed on the forged product obtained by the present invention. None, which is favorable in terms of product yield. The upper arm 54 shown in FIG. 5 was manufactured from the rough ground rough material by a conventional hot forging method using burrs. The number of times of forging was two, and the forging conditions were a heating temperature of the material of 500 ° C. and a mold temperature of 150 ° C. The forging load at this time was 22540 [kN] for the first time and 17 for the second time.
640 [kN]. After forging, deburring was performed using a Tomuri mold, and the shape was adjusted to obtain a product. At this time, the average weight of the disc-shaped cut product was 2330 g, and the product of the upper arm shown in FIG. 5 was 1650 g, and the yield based on the material weight of the forged product was 71%.

[Comparative Example 2] The upper arm rough ground rough material of Example 4 was manufactured by the conventional flash forming hot forging method shown in FIG. The forging conditions were a heating temperature of the material of 500 ° C. and a mold temperature of 180 ° C. JIS606
From the aluminum alloy continuous cast bar (diameter 80 [mm]) shown in 1 above, a cut product diameter 80 [mm] and length 3
60 [mm], volume 1810 [cm ³ ], material weight 49
00 [g] was cut and used as a forging material. The forging load at this time was 49000 [kN]. After forging,
Deburring was performed using a trim mold, and the shape was adjusted to obtain a product. In this method, two upper arm rough ground rough materials can be manufactured from one forging material. The average product weight of the two pieces was 1960 [g]. Therefore, in order to convert the forging load necessary to manufacture one rough crude material into a forging load, if the forging load is simply halved, the load becomes approximately 24500 [kN]. Further, the yield based on the material weight of the forged product is 8
It was 0%. This rough ground rough material is subjected to a burr removal hot forging method, which is a conventional method, to form an upper arm 7 shown in FIG.
4 was produced. The number of times of forging was the second time, and the forging conditions were a heating temperature of the material of 500 ° C. and a mold temperature of 180 ° C. The forging load at this time was 14700 [k] for the first time.
N] and the second time was 14700 [kN]. After casting
Deburring was performed using a trim mold, and the shape was adjusted to obtain a product. At this time, the weight of the cut product material (solid round bar 71) is 4
For 900 [g], the number of products 1650 [g] of the upper arm 74 shown in FIG. 7 was two, and the yield based on the material weight of the forged product was about 67%.

[Fifth Embodiment] In order to manufacture an upper arm which is a vehicle suspension part shown in FIG.
The rough material for upper arm wasteland forging shown in (1) was manufactured. A cut product of JIS6061 aluminum alloy having the same volume as that of the upper arm rough ground rough material was designed as a forging material as follows.

The product volume of the upper arm wasteland rough was calculated by a CAD system using a computer.
The volume of the cut product was set to 595 [cm ³ ] which is an error range of ± 1% of the calculated product volume.

Next, FIG. 2 perpendicular to the pressing direction M shown in FIG.
The thickness of the cut product is 30 [mm] which is 0.95 times the length of the short axis length t indicated by the reference symbol N in 7 and the cut product of the round bar material is determined from the volume of the cut product and the thickness of the cut product. The diameter (R) of

(Equation 15) And Where R is

(Equation 16) Satisfies the conditions. In FIG. 26, reference numeral 261 denotes a punch, 262 denotes a die, 263 denotes a knock, 264 denotes a knockout, and 265 denotes a coarse material for forging an upper arm.

Based on this design, a billet material (diameter 167 [mm]) made of continuous casting of an aluminum alloy specified in JIS6061 was used to obtain a diameter 167 [mm] and a thickness 30 mm.
[Mm], volume of 595 [cm ³ ]
0 was cut out. The average weight of a disk-shaped cut product is 1607
[G].

The surface of the disc-shaped cut product 281 is coated with a conventionally known water-soluble graphite lubricant, and the forging die is sprayed with a conventionally known water-soluble graphite lubricant, as shown in FIG. Hot forging was carried out by placing the disk at a suitable die position and applying weight from the outer peripheral surface of the disk with a punch. As a forging device, a 3000 t press manufactured by Sumitomo Heavy Industries, Ltd. was used. The forging conditions were hot forging at a material heating temperature of 500 ° C. and a mold temperature of 200 ° C. The average value of the forging pressure at this time was 4900 [kN].
Met.

The average weight of the product was 1800 [g]. The major axis length L of the projection surface of the forged product in the pressing direction indicated by the symbol O in FIG. 27 was 310 [mm] on average.

The yield of the product weight was 99% based on the material weight of the forged product. In addition, since the metal is plastically flowed in layers in a plurality of branches in a forged product, the mechanical strength is improved, and since it is closed forging, the forged product obtained by the present invention has no trim marks, This is favorable in terms of yield.

Example 6 Forging was carried out under the same conditions as in Example 4 above, except that the type of the aluminum alloy for the forging material was changed as follows.

In order to forge the upper arm waste material, which is an automobile suspension part shown in FIG. 6, this upper arm waste material is made of the same volume of SU610 aluminum alloy (Mg: 0.8-1.2% by weight%, Si : 0.
7 to 1.0%, Cu: 0.3 to 0.6%, Cr: 0.1
An aluminum alloy containing 4 to 0.3%, Mn: 0.14 to 0.3%, and the balance being Al and impurities) was used as a forging material.

[Comparative Example 3] In Comparative Example 2 described above, the same forging alloy type as in Example 6 was used, and forging was performed under the same other forging conditions.

[Strength Test / Metal Flow Observation] A forged product obtained by closed forging according to the present invention (Example 6)
A forged product (Comparative Example 3) obtained by deburring hot forging, which is a conventional method, is subjected to heat treatment under solution treatment conditions (held at 530 ° C. for 6 hours) and aging conditions (held at 180 ° C. for 6 hours). After the implementation, the portion indicated by reference numeral Q in FIG.
The tensile test pieces shown in ASTM-R3 (diameter 6.
(4 mm, distance between gauge points 25.4 mm) was cut out, and the mechanical properties were investigated. The tensile tester was performed under the conditions of a tensile load of 20 [kN] using an autograph of Shimadzu Corporation. The number of samples was 3 each, and the data of each mechanical property obtained at this time are shown in Table 3.

[0100]

[Table 3]

From Table 3, it can be seen that the forged product obtained by the closed forging according to the present invention has a higher tensile strength, 0.2% proof stress, than the forged product obtained by the burr-forming hot forging which is a conventional manufacturing method.
It can be seen that the elongation value is high and the mechanical properties are high. Next, in order to observe the metal flow of the branches of the obtained forged product and to observe the crystal grains near the parting line, a macrostructure observation material was cut out from the forged product, and the observation surface was polished with emery paper. A sample was prepared by immersing in a 20% sodium hydroxide solution for 30 seconds and performing an etching treatment. Metal flow observation and crystal grains near the parting line were observed by visual observation of the macrostructure. As a result, in the forged product obtained according to the present invention, the occurrence of defects such as fogging was not recognized because the cut surface of the forging material and the corner of the outer peripheral surface coincided with the outer peripheral contour of the forged product. In addition, a uniform flow pattern was observed along the plurality of branches of the forged product, and a layered metal flow that was not broken or disturbed was observed. This indicates that the forging material is in a layered plastic flow along the branches of the forged product. Furthermore, since there was no parting line in the forged product obtained according to the present invention, no coarsening of the crystal grains at the end of the product was observed. On the other hand, as a result of observing the macrostructure of the forged product obtained by the conventional method of burr removal hot forging under the above conditions, metal flows completely unrelated to a plurality of branch directions were observed. In the vicinity of the parting line at the end of the product, coarsening of crystal grains was observed.

[Embodiment 7] In Embodiment 6 described above, the split die 12 having the operating mechanism shown in FIG.
Except for using 1, forging was performed under the same forging conditions.

As for the dies, one of the divided dies was fixed, and the other was mechanically operated. At this time, the die was closed while the punch was being operated by the forging machine, the forging was finished, and the punch was opened after stopping at the top dead center of the forging machine.

As a result of the forging performed under the above conditions, no problem such as a sharp increase in the forging load such as seizure occurred in the forged product.

[0105]

According to the present invention, the volume of the forged product is the same as that of the forged product, and the ratio of the short axis length of the projection plane perpendicular to the pressing direction to the length in the pressing direction is 1 or less. The closed forging method in which a cylindrical ingot composed of an upper bottom surface and a lower bottom surface having no corners and side surfaces is used as a forging material and pressure is applied from the side surface of the cylindrical forging material. Since the material for plastic flows plastically in layers on multiple branches of the forged product, the mechanical properties are improved, and the forged product has no deburring marks and is suitable for improving the yield of the product for forging material. It is.

The yoke, which is a joint part used in the vehicle suspension according to the present invention, has improved mechanical properties because the forging material plastically flows in a plurality of branches of the forged product, and has improved trim marks. And the yield of the product with respect to the forging material is improved.

[0107] The rough shaped material for forging of the upper arm and the lower arm, which are the vehicle suspension parts in the present invention, is as follows:
Because the forging material plastically flows in layers in multiple branches of the forged product, the mechanical properties are improved, and the forged product has no deburring marks and the product yield for the forging material is improved. It is.

In the mold of the present invention, the shape of the space surrounded by the punch, the die, the knock and / or the bush, or the shape of the space surrounded by the die having the punch and the operating mechanism is determined by the volume of the forged product. The shape has a shape in which the ratio between the short axis length of the projection surface perpendicular to the pressing direction and the length in the pressing direction is 1 or less, and the upper and lower bottom surfaces do not include corners, Using a cylindrical ingot consisting of side surfaces as a forging material, the forging material can be installed so that pressure can be applied from the side of the cylindrical forging material, so the pressing force during forging is reduced. It can be reduced and the yield of the product with respect to the forging material is excellent, and has the effect of improving the mechanical strength of the forged product.

In the closed forging production system of the present invention, the shape of the space surrounded by punches, dies, knocks and / or bushes, or the shape of the space surrounded by dies having punches and operating mechanisms, Upper and lower bottom surfaces having the same volume as the volume and having a ratio of the short axis length of the projection plane perpendicular to the pressing direction to the length in the pressing direction of 1 or less, and having no corners. And, using a cylindrical ingot consisting of a side surface as a forging material, having a die that can be installed a forging material so that it can be pressed from the side surface of the cylindrical forging material Therefore, the pressing force at the time of forging can be reduced, the yield of the product with respect to the material for forging is excellent, and the mechanical strength of the forged product is improved.

[Brief description of the drawings]

FIG. 1 is a view showing an example of an embodiment of the present invention, and is a cross-sectional view showing a state in which an upper die has reached a bottom dead center position when forging a forged coarse material of an upper arm which is a vehicle suspension part. is there.

FIG. 2 is an external view of a yoke according to an example of the embodiment of the present invention.

FIG. 3 is a schematic view of a hot forging method for removing burrs of a yoke.

FIG. 4 is a schematic view of a manufacturing method based on a process of extruding a yoke, cutting, and machining.

FIG. 5 is an external view of an upper arm manufactured from an example of an embodiment of the present invention.

FIG. 6 is an external view of a rough shaped material for forging an upper arm according to an example of an embodiment of the present invention.

FIG. 7 is a schematic view of a hot forging method for removing burrs of an upper arm.

FIG. 8 is a schematic view when a VTR cylinder is manufactured by a closed forging method.

FIG. 9 is a schematic view of a conventionally known closed forging method.

FIG. 10 is a schematic diagram of a closed forging production system configuration according to an example of an embodiment of the present invention.

FIG. 11 is a schematic view of a configuration of a closed forging die according to an example of an embodiment of the present invention, and FIG. 11A illustrates an example of an integrated die;
FIG. 11B is a sectional view of the mold shown in FIG.
(C) is an example of a split mold.

FIG. 12 is a schematic perspective view showing another embodiment of the split mold used for closed forging of the present invention.

FIG. 13 is a cross-sectional view when the closed forging method of the yoke according to an example of the embodiment of the present invention is performed.

14 is a view of a projection plane perpendicular to the pressing direction in FIG.

FIG. 15 is a diagram showing an arrangement of the material and the mold in FIG. 13 before forging is started.

FIG. 16 is a view showing an arrangement of a material and a mold in a hot burr forging process of a yoke.

FIG. 17 is a drawing of a tensile test piece.

FIG. 18 is an external view of a yoke manufactured in Example 2.

FIG. 19 is a sectional view when a yoke is manufactured by a closed forging method in Example 2.

20 is a diagram of a projection plane perpendicular to the pressing direction in FIG.

FIG. 21 is a diagram showing an arrangement of a material and a die in FIG. 19 before forging is started.

FIG. 22 is a view of a projection plane perpendicular to the pressing direction in FIG. 1;

FIG. 23 is a diagram showing the arrangement of the material and the mold in FIG. 1 before forging is started.

FIG. 24 is an external view of another upper arm which is a vehicle suspension component manufactured from an example of the embodiment of the present invention.

FIG. 25 is an external view of a rough material for forging an upper arm of another embodiment of the present invention used in FIG. 24.

26 is a cross-sectional view when the closed forging method for manufacturing FIG. 25 is performed.

FIG. 27 is a view of a projection plane perpendicular to the pressing direction in FIG. 26;

FIG. 28 is a diagram showing an arrangement of the material and the mold in FIG. 26 before forging starts.

[Explanation of symbols]

11, 91, 111, 131, 162, 191, 26
1 Punch 12, 112, 132, 163, 192, 262 Dice 13, 114, 133, 193, 263 Knock 14, 134, 194, 264 Knockout 15, 61, 73, 265 Coarse material 21, 22, 23 Branch 31 Solid round bar 32,72 Burr 41,82 Material 42 Projection 43,135,195 Yoke 51,52,53 Part 54,74 Upper arm 71 Solid round bar 73a Forged product 81 Product 92 Branch 93,94 Gold Die 101 Material cutting device 102 Material supply device 103 Material heating device 104 Material transport device 105 Forging machine 106 Forged product unloading device 107 Forged product heat treatment furnace 113 Bush 115 Lubricant spray device 121 Split die 122 Arm 151,161,211,231 Cut products 281 Disc-shaped products A, D, I M pressing direction B, E, J, N minor axis C, F, K, O major axis length G branch leading end H burn unit P, Q moiety

Claims (16)

[Claims] 1. A closed forging method for producing a forged product, wherein the ratio of the short axis length of the projection surface perpendicular to the pressing direction to the length in the pressing direction is equal to or less than 1 in the volume of the forged product. It has a shape that does not include corners, and uses a cylindrical ingot composed of upper and lower bottom surfaces and side surfaces as a material for forging, and pressurizes from the side surface of the cylindrical material. And closed forging method. 2. The cylindrical material has a ratio (T / R) of a diameter (R) to a thickness (T) of 1 or less and is equal to the volume (V) of a forged product. The closed forging method according to claim 1, wherein the closed forging is a columnar cut product cut to have a volume. 3. The volume (V) of the forged product, the thickness (T) of the columnar material, the major axis length (L) of the projected area of the forged product in the pressing direction, and the cylindrical shape. The relationship with the material diameter (R) is: The closed forging method according to claim 1 or 2, wherein: 4. The thickness (T) of the columnar material is 0.8.
The closed forging method according to any one of claims 1 to 3, wherein the length of the forged product is a short axis length (t) of a projected area of the forged product in a pressing direction. 5. The closed forging method according to claim 1, wherein the material for forging is aluminum or an aluminum alloy. 6. The closed forging method according to claim 1, wherein the forged product is a member having a plurality of branches. 7. The closed forging method according to claim 6, wherein the member having a plurality of branch portions is a coarse material of an upper arm or a lower arm which is a vehicle suspension part. 8. The closed forging method according to claim 6, wherein the member having the plurality of branches is a yoke as a joint part used for a vehicle suspension. 9. A forging product manufactured by using the closed forging method according to claim 1, wherein a forging line flows along a branch of the forged product. Material of the upper or lower arm, which is a vehicle suspension part to be used. 10. An upper arm, which is a suspension component for a vehicle, manufactured by using the closed forging method according to any one of claims 1 to 6, wherein the forged product has no deburring marks. Or a lower-arm coarse material. 11. A forging line manufactured by using the closed forging method according to any one of claims 1 to 6, wherein the forging line has a flow along a branch portion of the forged product. Yoke, which is a joint part used for vehicle suspensions. 12. A joint part for use in a vehicle suspension manufactured by using the closed forging method according to any one of claims 1 to 6, wherein the forged product has no deburring marks. Is a yoke. 13. The closed forging method according to claim 1, wherein the die is a forging die including a punch, a die, and a knock. Mold to be done. 14. A closed forging production system including a material cutting device and a forging machine, wherein the forging machine is provided.
A closed forging production system, which is a forging machine having the mold described in 3. 15. The closed forging method according to claim 1, wherein the die is a forging die including a punch and a die having an operating mechanism. Mold. 16. A closed forging production system including a material cutting device and a forging machine, wherein the forging machine is provided.
A closed forging production system, which is a forging machine having the mold described in Item 5.