JPS60196238A - Manufacture of dice - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION This invention relates generally to rolling die casting machines and, more particularly, to a method for manufacturing rolling dies used in cross rolling mills.In conventional die forging of parts, billets (steel billets), A series of dies are used to continuously form blanks or pieces of material into finished products. A cavity is formed in each die, and each cavity gradually changes in shape depending on the die that is used sequentially, and is formed into a predetermined shape by slow pressing or stamping on the heated original pillet. It has become.

A useful modification to the basic die forging process application described above is the use of cylindrical die rolls to form a series of different cross-sections along a bar or billet of material. This cross-rolling method allows forgings with tapers, steps, shoulders, and any other surface of rotation to be formed accurately and efficiently. It is automatically fed between two rolls, both having parallel axes and rotating in the same direction. Each rotation of the machine roll yields one finished product, but two or more workpieces are placed between the ends.
These are often rolled at the same time.

Advantages of this forging method include less scrap, quiet and precise billet forming, and material diameter reduced by V2:1t in one pass.

Despite the above-mentioned advantages, the cross-rolling method also has disadvantages. This drawback is related to the generally high cost of designing and manufacturing the cylindrical dies used in forging machines; the design of these die shapes depends on the final shape to which the billet is to be machined. In conventional methods, test dies are made from easily machined materials to verify the design of cylindrical dies. The samples are then typically shaped on a 5-axis computer-controlled milling machine.

This advanced numerically controlled machine tool is very expensive and requires computer programming to perform the process, making this method impractical for many forging applications. In addition to the inherent high costs and long turnaround times, limitations in the hardness of the materials used also limit the practical application of the method; therefore, the advantages specific to the above-mentioned forging techniques have so far generally been limited to favorable industrial applications. As a tool it is not widely used at Pace.

The present invention seeks to overcome the above-mentioned limitations in the creation of cross-rolling dies. By significantly reducing the production of cylindrical dies used in cross rolling mills and their cost by converting them into hour wheels, the forging method described above can now be used in many technical applications in a wide variety of fields. OBJECTS AND SUMMARY OF THE INVENTION In view of the above, it is therefore an object of the present invention to provide an improved method for manufacturing cross-rolling dies.

Another object of the present invention is to greatly simplify and reduce the manufacturing and cost of wedge-shaped cylindrical forming dies used in conventional cross rolling mills.

The present invention contemplates the construction of a cross-rolling die that substantially eliminates the complexity and expense associated with conventional methods. A flat blank model made of a conventional material that is easy to work with, such as wood, is worked to the appropriate length and contoured according to the desired shape of the cross-rolling die. A surface casting or cross-rolling die negative impression of the contoured wooden model blank is then made, which is used to make a positive casting of the preformed blank. The preformed model blank and its positive casting are then provided with a series of closely spaced parallel cuts extending through the entire thickness of each element and located parallel to the roll axis of the die when installed in the cross rolling mill. Flexibility is included in each. The model blank and positive casting are then divided into appropriate segments spanning the 615° circumference of the cross mill. Thereafter, the pre-formed model blank and the positive casting are cross-rolled by positioning the mountings separately on the plate and forming each of the above-mentioned mountings with a hardening filler into the cross notch expanded by the curvature. The surfaces of the model blank and positive casting are polished to adjust the surface contours of both elements to the desired shape.

The preformed wooden blank thus formed and the positive casting are used together to test the cross-rolling die design to be provided. The shape of the original billet to be formed is determined by subjecting any material that is easy to form, such as ordinary glass, to a cross-rolling process using a positive casting product. The shape of the cross-rolled malleable die is then compared to the desired die shape to evaluate the outer shape of the model blank profile. If changes are required, they can be easily incorporated into the preformed wooden blank and another positive casting via negative impressions and then tested again under the actual environment of the cross mill.

This method simplifies and reduces the design, fabrication and production of dies for cross-rolling mills and their costs. After the cross-rolling die design verification, sand castings are made from each segment of the positive casting, and A face casting is made. An abrasive die casting is then made from each face casting. Next, after the graphite electrode is ground for each grinding die, a cross-rolling die blank is formed by electrical discharge machining (EDM) to produce a cross-rolling die.

Considered novel features of the invention are set forth in the claims. However, the nature of the invention, its objects and advantages, may be better understood by reference to the following detailed description of the preferred embodiments, illustrated in the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1.2, there is shown the general configuration of a cross rolling mill 20 for producing forgings with single-stage chinons, shoulders, or any other surface of rotation. .

Cross rolling mill 20 generally includes two adjacent rolls 22, 24 located close to each other and having parallel axes of rotation. As shown by the arrow in FIG. 1, the rolls 22, 24
are rotated in the same direction, a billet or piece of material 30 is placed between both rolls, and a pair of spaced apart guide plates 32
is held in position by. Thirty preheated metal bars or billets are automatically fed between the rolls 22, 24 (parallel to the roll axis). Wedge-shaped forming dies 26 and 28 are respectively attached to both rolls, and these dies have a V-cylindrical cross section and gradually squeeze the bar or billet 30 during their rotation. Machine rolls 22 and 240
One revolution produces a finished product, which is gradually formed from an initial cylindrical shape to a workpiece with the desired contour surface, as shown in FIG.

As shown in Figure 1.2, a wet die 26.
28 is attached to each roll perpendicular to the axis of the billet to be fed, 24 is attached to the soil, and when the billet is positioned between both rolls and the rolls begin to rotate, the workpiece 30 is moved by the action of the plow 1. Start processing. Along with this, the billet is squeezed, forming a workpiece that becomes gradually elongated along its center line, as shown continuously from the left side to the right side in Figure 3, and the grains flow according to the contour of the finished product. give rise to The finished product falls into a gutter (not shown) located near the end of the rotating roll and is automatically ejected forward as the roll begins to rotate again to form the next billet. As will be described in detail below, the present invention has a cross rolling mill 2.
This invention relates to an improved method for making the dies 26, 28 used in o.

Figures 4-19 illustrate the method of fabricating the cross-rolling die contemplated by the present invention. This method includes the steps shown in FIGS. 4 to 19.
It consists of a series of steps shown in sequence in the figures and accompanying drawings. Each of these stages will be explained in detail below.

FIG. 4 shows a typical example of the use of the present invention, in which a preformed blank for a tie rod is exploded. The cross mill 2o of Figure 1.2 is used to form a preform that is selectively shaped and contoured to the desired shape of the tie rod or any other final product. When the tie rod preform is forged by a cross rolling mill and discharged from there,
A final forging step is then performed in which the tie rod preform 34 is formed into its final product 36.

The second stage of the invention is shown in FIG. This step includes the design of any loss tooling necessary to form the preformed blank of the desired shape. Milling designs for preformed blanks is essentially a mathematical process in which a certain number of equations must be satisfied for a particular material and a given shape of the desired final product. Some parameters taken into these calculations include, for example, the difficulty of deformation of the processed material, the deformation rate, and its limit. As a result of this theoretical development, the die designer will be able to determine the forming angle and wedge angle of the die that should be used in the cross rolling mill.

The next step, shown in FIG. 6, is the fabrication of a model blank for flat loss rolling tooling, preferably made of wood. This model blank is cut to the predetermined dimensions of the cross-rolling die in terms of its width, length and required thickness. 7th
In the fourth stage shown in the figure, this wooden model blank is pivotably placed on a pattern milling machine, allowing the wooden blank to rotate freely about an index point fixed to the table VC of the vertical milling machine. In order to adjust the cut angle correctly - a transverse stone/base corresponding to the limit of the wedge angle is placed on the table of the vertical milling machine.

The wooden model blank is then milled according to the contours of the cross-rolled tooling given in the preformed design necessary to form the preformed blank from which the final forging is obtained, as shown in Figure 8. be done. That is, a model blank is placed on the table of a milling machine at a desired angle, and then milling is performed in a conventional manner using a forming cutter.

The next step in the method of the invention is to make a face casting toe impression of the profiled model blank which is milled according to the theoretical optimum shape of the cross-rolling die, as shown in FIG. The next step, shown in Figure 10, is to make a negative impression of the face forging, which represents a positive casting of the profiled model blank. Give two equally contoured models. The model blank for cross-rolling tooling is preferably made of a material such as wood, but the above-mentioned positive casting is preferably made of a clay-like material in order to produce a hardened model of the cross-rolling die.

As shown in Figure 11, the next step in the method is to cut the model blank and its positive casting into a series of Y-row linear serrations, which are rotated by the rolls of a cross mill. oriented parallel to the axis. These cuts are made to a depth in the model blank and its positive casting to give each element radial flexibility. Radial:fr flexibility is generally obtained in the model described above by cutting at a depth l within about 1716 inches (0.6 cm) of the opposite surface of the model. Next, the model blank and the positive casting are made by
It is divided into suitable segments with a total central angle of 315° corresponding to the arc covered by wedge-shaped dies placed on the rolls of a rolling mill.

In a preferred embodiment, the model blank and the positive object are divided into five sections each having a central angle of 90 DEG and a fourth section having an arc of central angle 45 DEG.

In the next step, as shown in FIG.
The cross rolling die above is attached to the plate. This attachment is accomplished in a conventional manner, with each roll attached using a plurality of bolts screwed to the plate. The model blank and positive casting are mounted separately onto the plate and fixed firmly. In the next step, as shown in Fig. 14, the cross-rolling die is installed, and a hardening filler is added into each serration-shaped cut widened by the bending action during fixation to the plate, as shown in Fig. 15. The curved peripheral surfaces of the thus filled model blanks and positive castings are then molded to remove the irregularities and give smooth contoured surfaces, where the hardening filler is applied to the wood of the model blank and the positive castings, respectively. It blends smoothly with the clay of the casting.

Next, each attachment of the machine roll is applied to the model blank and positive casting by inserting the workpiece made of malleable material into a cross rolling mill with the model blank and positive casting placed on a plate. The developed design is tested. The profile of the malleable material thus formed is compared to the desired shape of the final forging, and the die design is verified immediately or after modifications. Modifications to the exterior and cedar of model blanks and positive castings are easily possible and quickly verified. All of these are hard and strong dice <m +
This can be achieved without the need for the time-consuming and expensive steps required to process the die into the desired shape. Therefore, according to the present invention, the steps required to manufacture dies for cross rolling mills can be greatly reduced. The hour wheel is made shorter and shorter, making it possible to use hard and strong die steel while reducing costs.

The next step, shown in Figure 16, is to create the face construction for each segment. As shown in FIG. 17, polishing die castings for each segment are formed from the negative face castings thus obtained. Next, as shown in FIG. 18, the graphite electrode is polished by these polishing dies formed in the shape of each segment of the model blank. This graphite electrode is then used for electrical discharge machining of a cross compression die blank in an electrical discharge machine (ED tA ). These steps, including EDM'i, involved in the production of die blanks are common practice, so they will not be explained further here.

The die blank shown in FIG. 9 formed in step 16 provides a cross-rolling die of a verified design and lameter that can be cross-rolled without the need for further testing, rework or verification. It can be used in

Although a specific embodiment of the present invention ψ1 has been illustrated and demonstrated, it will be apparent to those skilled in the art that modifications and changes to the six combs may be made without departing from the full characteristics of the invention.

It is therefore intended that the appended claims cover all such changes and modifications as fall within the true spirit and scope of the invention.

[Brief explanation of drawings]

Figure 1 is a side view of the cross rolling mill, showing the position f of the billet formed between the cross rolling dies; Figure 2 is a perspective view of the cross rolling mill shown in Figure 1; Figure 5 is the figure shown in Figure 1. Figures 4 to 19 are schematic diagrams illustrating the method of forming a cross-rolling die according to the invention, as shown in Fig.・ 20...Cross pressure +ffi! , 22.24... Roll, 26.28-... Molding die, 3o... Billet (piece of material), 34... Preformed product, 3G... Final product.

Claims (1)

[Claims] (1) relates to a method for manufacturing a rolling die having a cylindrical cross section and for forming a processed product into a desired shape on a forging machine: Cutting 9. Forming a flat model blank of the die with a milled surface according to the design/4' rametre necessary to form the workpiece into the desired shape: Step of producing a positive @ memento of the flat model blank having a contour forming surface equal to that of the milling process: The milling surface of the flat model blank and the contour forming surface of the positive casting are connected to the roll axis of the die. A plurality of parallel, mutually parallel, linear cuts are formed, the depth of which imparts radial sinterability to the model blank and its positive casting.
:The step of applying the material to the machine; in this installed state, filling the plurality of notches in the model blank and the positive casting with a hardening filler;
A step in which both surfaces of the model blank and the positive casting are made to have a cylindrical cross-sectional shape that matches the design/4' parameter of the rolling die by kerating: Malleable by the positive casting on the forging machine. The model blank is created by molding a blank workpiece, comparing the shape of the molded workpiece with the desired shape, and modifying each surface of the model blank and positive casting as necessary to obtain the desired workpiece shape. and, after verifying the design of the model blank, producing a grinding die casting from the positive forging, and forming a rolling blank die using an electrical discharge machine using the grinding die casting; 2) The method of claim 1, wherein said flat model blank comprises wood. The method according to the first term of the scope. 4. The method of claim 1, further comprising the step of flattening the filling surfaces of said model blank and positive casting and smoothing their respective composite surfaces. (5) further comprising the step of making a negative impression of the profiled surface of the model blank to form a negative impression of the shape t[L of the face casting, from which a positive casting of the model blank is made.
(6) The forging machine is a cross rolling mill, and the model blank and positive casting are divided into a plurality of individual segments before being installed on the cross rolling mill. the method of. (7) The method according to claim 6, wherein the model blank and the blank casting are each divided into four segments forming an arc having a total central angle of about 615 degrees when the model blank and the blank casting are installed in a cross rolling mill. (8) The method according to claim 6, in which the abrasive die casting is made of silicon carmite. (9) The method according to claim 1, in which the positive casting is made of clay-like material. Claims: wherein the step of forming the flat model blank according to the design parameters is carried out by a computerized numerically controlled two-way milling cutter.
Method of item 1 (b) has a cylindrical cross section and a wedge-shaped surface,
A method for actually manufacturing a rolling die for forming a processed product into a desired shape on a cross rolling mill: including the wedge angle and forming angle of the die, the method for forming the processed product into the desired shape. Determining the required design parameters: Forming a flat wooden model blank of the die, cut to the dimensions of the die and milled according to the design parameters of the die to provide a contoured surface: Making a negative impression in the form of a face casting on the contoured surface of the wooden model blank: Making a positive casting of the face casting with a contouring surface equal to the wooden model blank; step; forming a plurality of mutually parallel linear cuts in the wooden model blank and the positive casting in parallel with the roll axis of the die, and the depth of the cuts is z−y with respect to the wooden model blank;
a step of imparting radial flexibility to the casting; a step of separately mounting the wooden model blank and the bod casting to the cross rolling mill; a step of attaching the wooden model blank to the cross rolling mill; and filling the notch of the positive casting with a hardening filler, so that both the surfaces of the wooden model blank and the positive casting have a y-cylindrical cross-sectional shape and a wedge-shaped surface that matches the design diameter of the die above. Step 1: Flattening the wedge-shaped surfaces of the water ring model blank and the boss casting, and smoothing the composite surfaces of each: Processing of malleability by the boss casting on the cross rolling mill. The product is cross-rolled to give the shape of the formed product a desired >'f
Step of horizontally placing the wooden model blank A1 by modifying the surface of the wooden model blank as necessary to form the desired processed product shape: After verifying the installation H1 of the die, A step of producing a face casting product of the cast product; a step of producing a fr polishing die dipping product of the face@fabricated product; a step of polishing a graphite electrode with the polishing die &5 product; and a step of using the above graphite electrode. , forming a die blank for cross rolling by means of a free-forming machine.