JP3433059B2 - Processing method of cylindrical body with flat surface and press blank used for the processing - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method for pressing a flat-faced cylindrical body from a strip-shaped material, and more specifically, a flat surface is formed on the outer periphery of the cylindrical body to form a flat portion. The present invention relates to a method of processing a cylindrical body having a wall thickness smaller than that of a cylindrical portion.

[0002]

2. Description of the Related Art In the prior art, for example, a technique relating to a housing for a coreless motor is disclosed in Japanese Patent Laid-Open No. 6-217505.
It is disclosed in the publication. The present invention, as shown in FIG. 6, is a thin portion (flat portion) parallel to the axial direction of the housing 11.
To reduce the size of the coreless motor, prevent leakage of magnetic flux, and improve the output characteristics of the coreless motor. The thin portion (flat portion) parallel to the axial direction of the housing 11 forms a cylindrical body in advance by press working or the like, and the outer periphery of the cylindrical body is cut to form a cutting surface 12 (flat surface) parallel to the axial direction. It is a processing method for cutting. As described above, in the processing method of forming the flat portion on the cylindrical body, the flat surface is ablated exclusively by cutting.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method of cutting a flat surface on a cylinder by cutting, it is difficult to process the flat surface with a predetermined parallelism with respect to the center axis of the cylinder, and it is possible to process two flat surfaces with a predetermined parallelism. It is difficult to do so, and it is difficult to machine the central axis of the two flat surfaces with a predetermined concentricity with respect to the central axis of the cylindrical body. There was a problem that can not be. Also, in cutting,
Since it is necessary to attach and detach the cutting work (cylindrical body) and the cutting speed is limited, it is difficult to improve productivity,
There was the problem of increased costs.

The present invention has been made in view of the above problems of the prior art, and an object thereof is the parallelism of the flat surface with respect to the central axis of the cylindrical portion of the flat surface-added cylindrical body. An object of the present invention is to provide a press working method capable of mass-producing a flat-faced cylindrical body having high processing accuracy such as concentricity and uneven thickness of a flat portion with high production efficiency.

[0005]

In order to achieve the above object, the present invention as set forth in claim 1 is such that a flat surface is formed on the outer periphery of a cylindrical body and the thickness of the flat portion is smaller than the thickness of the cylindrical portion. A method for processing a thin flat-faced cylinder, wherein a blank is formed on a strip-shaped material by a punching punch and a punching die to form a blank, and a cup is drawn on the blank by a drawing punch and a drawing die. A cup-shaped cylindrical body is formed, and the cup-shaped cylindrical body is contracted and extended by a predetermined number of times of redrawing with a drawing punch and a drawing die to form a cylindrical portion and a flat portion, and ironing is performed in at least one step. Then, the cylindrical body in which the flattened portion which is thinner than the wall thickness of the cylindrical portion is formed is processed.

According to the present invention, the cylindrical portion and the flat portion are pressed and drawn by the drawing punch and the drawing die to reduce the diameter and extend the flat portion to make the flat surface thinner than the thickness of the cylindrical portion. Since it is formed, the parallelism and concentricity of the flat surface with respect to the central axis of the cylindrical portion of the flat surface-attached cylindrical body,
It is possible to mass-produce a flat-faced cylindrical body with high processing accuracy such as uneven thickness of the flat portion with high production efficiency.

Further, in the method described in claim 2, the flat surface of the flat portion formed thinner than the wall thickness of the cylindrical portion on the outer periphery of the cylindrical body is a flat surface of two parallel flat surfaces. It is a method of processing a cylinder with an attachment.

According to the present invention, the cylindrical portion and the two parallel flat portions are pressed and drawn by the drawing punch and the drawing die to reduce the diameter and extend the two parallel flat portions. Since it is made thinner than the wall thickness of the flat surface to form a flat surface, the parallelism and concentricity of the flat surfaces of the two parallel surfaces with respect to the central axis of the cylindrical portion and the uneven thickness of the two flat surfaces in parallel are It is possible to mass-produce highly accurate flat-faced cylinders with high efficiency.

The method described in claim 3 is a method for processing a cylindrical body with a flat surface, in which the blank formed by the blank processing is circular.

According to the present invention, since all punches can be formed in a columnar shape, the cost of manufacturing the die can be reduced.

Further, in the method described in claim 4, the blank formed by the blanking process has an elliptical shape, and the blank is made to correspond to the flat portion of the cylindrical body in which the elliptical minor-side curved portion is formed. It is arranged and processed.

According to the present invention, the blank is formed into an elliptical shape, and the radial phase cross-sectional areas including the bottom, side wall, and trimming margins for sizing the entire length with respect to the plane coordinate center of the flat-faced cylindrical body, and the blank. Since the radial phase cross-sections with respect to the plane coordinate center of and are set to approximate cross-sections, the excess bulge that bulges into the opening of the cylinder during redrawing is averaged, and the local excess bulge is expanded. Since the protrusion does not occur, it is possible to prevent an obstacle in the press working due to interference with the die set member and the like, and it is possible to eliminate the step of trimming the locally bulged surplus in the intermediate step of the redrawing.

According to a fifth aspect of the present invention, the blank formed by blanking is made to correspond to a flat portion of a cylindrical body having an oval shape and parallel linear shaped portions of the oval shape. It is arranged and processed.

According to the present invention, the blank is formed into an oval shape, and each radial phase cross-sectional area including a bottom portion, a side wall portion, and a trimming margin for sizing the entire length with respect to the plane coordinate center of the flat-faced cylindrical body, and the blank. Since the radial phase cross-sections with respect to the plane coordinate center of and are set to approximate cross-sections, the excess bulge that bulges into the opening of the cylinder during redrawing is averaged, and the local excess bulge is expanded. It is possible to prevent the trouble in the press working due to the interference with the die set member and the like, and to eliminate the step of trimming the locally bulged surplus in the intermediate step of the redrawing work.
Further, after the blank processing, the corrugated portion formed on the strip-shaped material can be made narrow, so that the material yield can be improved.

According to a sixth aspect of the present invention, the die is an elliptical columnar shape up to the intermediate step of re-drawing of the reduced diameter, extension and circular shape of the throttle cylinder and thinning of the flat portion. Processed with the drawing punch formed in and the drawing die having an elliptical cross section of the inner circumference of the hollow hole, and the mold between the intermediate step and the final redrawing process was formed into a cylindrical shape. This is a method for processing a cylindrical body with a flat surface, which is processed by a drawing punch and a drawing die in which a flat portion is formed in which the inner circumference of the hollow hole is circular in the inner circumference.

According to the present invention, in the press processing in which the blank formed by the blank processing has an elliptical shape, the die is formed in conformity with the shape, drawing rate, ironing rate, etc. of each pressing step. Therefore, it is possible to perform processing without damaging the die or causing a defect in the work.

Further, in the method described in claim 7, the mold up to the intermediate step of re-drawing of the reduced diameter, extension and circular shape of the throttle cylinder and thinning of the flat portion is an oval column shape. Processed with the drawing punch formed in and the drawing die having an oval-shaped cross section of the inner circumference of the hollow hole, and the mold between the intermediate step and the final redrawing process was formed into a cylindrical shape. This is a method for processing a cylindrical body with a flat surface, which is processed by a drawing punch and a drawing die in which a flat portion is formed in which the inner circumference of the hollow hole is circular in the inner circumference.

According to the present invention, in the press processing in which the blank formed by the blank processing has an oval shape, the mold is formed in conformity with the shape, drawing rate, ironing rate, etc. of each press processing step. Therefore, it is possible to perform processing without damaging the die or causing a defect in the work.

Further, in the press blank according to the present invention, a flat body having two flat surfaces parallel to the outer circumference of the cylindrical body is formed, and the thickness of the flat portion is smaller than that of the cylindrical portion. A blank for a press used for, which is formed into an elliptical shape from a curved portion on the short diameter side and a curved portion on the long diameter side connected to the curved shape portion on the short diameter side, and an elliptical cup-shaped tubular body When flattening the cup, the flat portion of the cup-shaped tubular body is processed with the curved portion on the short diameter side, and the excess thickness that bulges into the opening of the tubular body during redrawing is averaged. It was designed to be transformed.

According to the present invention, the blank is formed into an elliptical shape, and the radial phase cross-sectional areas including the bottom, side wall, and trimming margins for sizing the entire length with respect to the plane coordinate center of the flat-faced cylinder, and the blank. Since the radial phase cross-sections with respect to the plane coordinate center of and are set to approximate cross-sections, the excess bulge that bulges into the opening of the cylinder during redrawing is averaged, and the local excess bulge is expanded. It is possible to prevent the trouble in the press working due to the interference with the die set member and the like, and to eliminate the step of trimming the locally bulged surplus in the intermediate step of the redrawing work.

Further, in the press blank according to the ninth aspect of the present invention, the cylindrical body is formed with two flat surfaces parallel to the outer periphery of the cylindrical body and the thickness of the flat portion is thinner than the thickness of the cylindrical portion. A blank for a press used for, which is formed into an oval shape from a parallel linear part and semicircular parts connected to both ends of the parallel linear part, and cup-drawn into an oval cup-shaped tubular body. When the flat portion of the cup-shaped tubular body is processed by the parallel straight-lined portions when performing, the extra thickness bulging into the opening of the tubular body during redrawing is averaged. Is.

According to the present invention, the blank is formed into an oval shape, and each radial phase cross-sectional area including the bottom portion, the side wall portion, and the trimming margin for sizing the entire length with respect to the plane coordinate center of the flattened cylindrical body, and the blank. Since the radial phase cross-sections with respect to the plane coordinate center of and are set to approximate cross-sections, the excess bulge that bulges into the opening of the cylinder during redrawing is averaged, and the local excess bulge is expanded. It is possible to prevent the trouble in the press working due to the interference with the die set member and the like, and to eliminate the step of trimming the locally bulged surplus in the intermediate step of the redrawing work.
Further, after the blank processing, the corrugated portion formed on the strip-shaped material can be made narrow, so that the material yield can be improved.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on examples with reference to the drawings. The present invention is composed of selection of a press machine when pressing a flat-faced cylinder, blank shape, processing order and number of steps, mold, etc. It demonstrates with reference to FIG. 3 which shows the relationship between the cylindrical body with a flat surface, and a blank.

The basic working procedure of the cylindrical body by press working is to blank a strip-shaped material with a punch and a punch to form a flat blank, and draw a punch and a die on this blank. To form a cup-shaped cylindrical body, and the cup-shaped cylindrical body is redrawn by a drawing punch and a drawing die for a predetermined number of times to reduce the diameter of the cylindrical body and extend it for plastic working. However, the plastic deformation between the machining process and the preceding process is that the plate on the radial phase cross section with respect to the plane coordinate center of the workpiece in the preceding process is defined in the mold of the machining process, and the plane of the mold. It is a centripetal movement toward the center of coordinates. When the cross-sectional shape of the work and the mold in the processing step and the preceding step is not similar to each other, the movement of the plate meat is centripetally moved to the center of the plane coordinate and the plate meat of the non-similar part is moved. Also moves in the circumferential direction.

FIG. 3 is a plan view showing the relationship between the workpiece W, which is a cylindrical body with a flat surface in the final processed shape, and each blank, and the workpiece W has the plane coordinate center O of the cross section as its axis. It is formed of a cylindrical portion 7 and a flat portion 6 having two parallel flat surfaces, and the flat portion 6 is a bottomed cylindrical body with a flat surface thinner than the cylindrical portion 7. .

In the blank for drawing the workpiece W of the flat-faced cylindrical body, the plate thickness is centripetally moved toward the plane coordinate center of the die for each processing step as described above. Therefore, the radial phase cross-sectional areas including the bottom, side wall, and trimming margins for sizing the entire length with respect to the plane coordinate center O of the work W and the radial phase cross-sectional areas with respect to the plane coordinate center O of the blank have the same area. If the calculation is performed as described above, the blank shape is geometrically determined as the calculation blank 4 shown by the alternate long and short dash line in FIG. In this calculation, the semicircular R shape formed at each intersection of the flat surface of the outer periphery of the flat portion 6 of the workpiece W and the outer peripheral surface of the cylindrical portion 7.
Was ignored and calculated. If this calculation blank 4 is drawn in the above-described processing order, the work W that is a cylindrical body with a flat surface is obtained.
Can be formed.

However, the above calculation blank 4 is
The yield rate of the material is poor due to the large amount of scrap remaining in the strip-shaped material described later, and the die manufacturing cost is high due to the complicated cross-sectional shape of the punch and die for blanking and drawing. There is a drawback that becomes.

Therefore, as a blank for solving such a drawback, a circular blank 3 shown in FIG. 3, an oval blank 2 in which each phase cross-sectional area is similar to the calculation blank 4, or each phase cross-sectional area is It may be formed into an elliptical blank (not shown) which is similar to the oval blank 2. In the one circular blank 3 shown in the figure, since all punches can be formed in a cylindrical shape as described later, the die manufacturing cost can be reduced,
Since each phase cross-sectional area of the shaded portion 5 is large, the excess thickness that bulges into the opening of the cylinder during redrawing is not averaged, and the excess thickness locally bulges in the intermediate step of redrawing. However, a process for trimming this local extra thickness is required. Also,
The material yield is also not very good.

On the other hand, the other oval blank 2
The mold production cost is slightly higher than that of the circular blank 3, but as shown in FIG. 1, the yield of the material is preferable because the portion remaining as scrap in the strip-shaped material 1 can be narrowed. Trimming in the intermediate process because the excess bulge that bulges in the opening of the cylinder during redrawing is averaged and the amount of bulge that locally bulges in the intermediate process of redrawing is small. Is unnecessary.

The oval blank 2 is drawn by the radiation passing through each intersection of the flat plane of the outer periphery of the flat portion 6 and the outer peripheral surface of the cylindrical portion 7 with the plane coordinate center O of the work W as the origin. , The upper and lower portions of the X-shaped phase line shown in the figure are formed in a straight line approximately parallel to the coordinate values of the calculation blank 4, and the both end portions in the left and right portions of the X-shaped phase line shown in the figure are parallel straight line portions. It is obtained by forming a semicircular shape continuous with.

The X-shaped phase line of the oval blank 2 thus obtained has an excess and deficiency with respect to the calculation blank 4 in the illustrated left and right portions and in the illustrated left and right portions, respectively. As mentioned above, the plate thickness on each phase cross section is centripetally moved toward the plane coordinate center of the die defined by the die in each processing step as described above, and is also offset in the circumferential direction. This is the range that can be done.

The elliptical blank (not shown) belongs to an intermediate position between the circular blank 3 and the oval blank 2, but its characteristics are almost similar to those of the oval blank 2.

Subsequently, a method of processing the flat-faced cylindrical body when the blank has an oval shape will be described with reference to FIGS. 1 and 2. FIG. 1 shows a strip-shaped material obtained by punching out an oval-shaped blank, and FIG. 2 is an explanatory view showing a working mode in which a flat-faced cylinder is pressed from the oval-shaped blank.

FIG. 2A shows an oval-shaped punching punch (not shown) in the blanking process of the press machine,
The shape of the oval blank 2 punched from the band plate-shaped material 1 shown in FIG. 1 is formed by a die with a punching die in which the cross section of the female die is formed into an oval shape so that the punching punch can be inserted. Show. The diameter ratio of the major axis A ₀ and the minor axis B _{0 of} this oval blank 2 is formed as A ₀ / B ₀ = 1.47.

FIG. 2 (b) shows that, in the next cup drawing process, by using a die of an oval columnar drawing punch (not shown) and a drawing die having a female die with an oval cross section, FIG. The shape of the cup-shaped cylindrical body Wb obtained by cup-drawing the oval blank 2 shown in a) is shown. The diameter ratio of the major axis A ₁ to the minor axis B ₁ on the outer peripheral side of the cup-shaped cylindrical body Wb is A ₁
/ B ₁ = 1.49, the diameter ratio of the major axis a ₁ on the inner circumference side to the minor axis b ₁ is a ₁ / b ₁ = 1.50, and the drawing rate on the major axis side is A ₁ / A
₀ = 0.76, the reduction ratio on the minor axis side is B ₁ / B ₀ = 0.7
5, the ironing rate on the major axis side is t-m ₁ /t=0.03, and the ironing rate on the minor axis side is t-n ₁ /t=0.33, which are formed by the above-mentioned mold. Is.

In the next redrawing step, FIG. 2 (c) shows a die made up of an oval-shaped columnar aperture punch (not shown) and an aperture die having an oval cross section of a female die.
FIG. 3 shows the shape of a drawn cylindrical body Wc obtained by redrawing the cup-shaped cylindrical body Wb shown in FIG. The diameter ratio of the major axis A ₂ to the minor axis B ₂ on the outer peripheral side of the throttle cylinder Wc is A ₂ / B ₂ = 1.3.
7, diameter ratio of the major axis to a ₂ to the minor axis b ₂ of the inner peripheral side a ₂ / b ₂
= 1.31, the aperture ratio of the major axis side is A ₂ / A ₁ = 0.77,
Drawing rate of the short diameter side B ₂ / B ₁ = 0.85, ironing ratio of the major axis side is _{m 1 -m 2 / m 1 =} 0.03, ironing ratio of minor axis is n ₁ -n ₂ / n ₁ = 0.25, which are formed by the above mold.

In the next redrawing process, FIG. 2 (d) shows a die made up of an oval columnar drawing punch (not shown) and a drawing die having an oval cross section of a female die.
3 shows the shape of a diaphragm cylinder Wd obtained by redrawing the diaphragm cylinder Wc shown in FIG. The diameter ratio of the major axis A ₃ to the minor axis B ₃ on the outer peripheral side of the cup-shaped cylindrical body Wd is A ₃ / B ₃ = 1.3.
5, diameter ratio of the major axis to a ₃ and a minor axis b ₃ of the inner peripheral side a ₃ / b ₃
= 1.26, the reduction ratio on the major axis side is A ₃ / A ₂ = 0.82,
The drawing ratio on the minor axis side is B ₃ / B ₂ = 0.83, the ironing rate on the major axis side is m ₂ −m ₃ / m ₂ = 0.04, and the ironing rate on the minor axis side is n ₂ −n ₃ / n. ₂ = 0.17, which are formed by the mold.

FIG. 2 (e) shows that, in the next redrawing process, by using a die having an oval columnar aperture punch (not shown) and an aperture die having an oval cross section of a female die,
3 shows the shape of a diaphragm cylinder We obtained by redrawing the diaphragm cylinder Wd shown in FIG. The diameter ratio of the major axis A ₄ to the minor axis B ₄ on the outer peripheral side of the cup-shaped tubular body We is A ₄ / B ₄ = 1.2.
4, diameter ratio of the major axis to a ₄ and a minor axis b ₄ of the inner peripheral side a ₄ / b ₄
= 1.12, the reduction ratio on the major axis side is A ₄ / A ₃ = 0.84,
Drawing rate of the short diameter side B ₄ / B ₃ = 0.92, ironing ratio of the major axis side is _{m 3 -m 4 / m 3 =} 0.02, ironing ratio of minor axis is n ₃ -n ₄ / n ₃ = 0.12, which are formed by the above mold.

FIG. 2 (f) shows, in the next redrawing process, a die having a cylindrical drawing punch (not shown) and a drawing die having an oval cross section of the female die.
A diaphragm cylinder W obtained by redrawing the diaphragm cylinder We shown in (e).
The shape of f is shown. The diameter ratio between the major axis A ₅ and the minor axis B ₅ on the outer peripheral side of the cup-shaped cylindrical body Wf is A ₅ / B ₅ = 1.15, and the major diameter a ₅ on the inner peripheral side and the minor diameter b ₅ are: a ₅ / b ₅ = 1.
00 (that is, the portion except the flat portion is circularized to form a cylindrical portion at this stage), and the reduction ratio on the major axis side is A ₅ / A ₄
= 0.86, the reduction ratio on the minor axis side is B ₅ / B ₄ = 0.93,
The ironing rate on the major axis side is m ₄ -m ₅ / m ₄ = 0.02, and the ironing rate on the minor axis side is n ₄ -n ₅ / n ₄ = 0.09.
These are formed by the mold.

FIG. 2 (g) shows a process of redrawing in the next step by using a die including a cylindrical drawing punch (not shown) and a drawing die in which the female die has an oval cross section.
A diaphragm cylinder W obtained by redrawing the diaphragm cylinder Wf shown in (f).
The shape of g is shown. Diameter ratio of the major axis A ₆ to the minor axis B ₆ of the outer peripheral side of the cup-shaped cylindrical body Wg is A ₆ / B ₆ = 1.15, diameter ratio of the major axis to a ₆ to the minor axis b ₆ of the inner peripheral side a ₆ / b ₆ = 1.
00, the draw ratio on the major axis side is A ₆ / A ₅ = 0.96, the draw ratio on the minor axis side is B ₆ / B ₅ = 0.95, and the ironing rate on the major axis side is m ₅ -m ₆ / m ₅ = 0.04, ironing rate on the minor axis side is n ₅
A -n ₆ / n ₅ = 0.05, which are intended to be formed by the mold.

FIG. 2 (h) shows the shape of a flat-faced cylindrical work W whose overall length has been determined by cutting the opening by a trimming punch and die die (not shown) in the next trimming process. Indicates.

In the above description, each process of FIGS. 2A to 2H was described in order to clarify the processing form of each process, but in the embodiment, it is shown in FIG. The blank processing shown in Fig. 2 and the cup drawing processing shown in Fig. 2 (b) are performed by the first stage of the transfer press having a double action mechanism in the first stage, thereby making the oval blank 2
2C and the cup-shaped cylindrical body Wb are drawn and drawn within one operation of the press slide, and the cup-shaped cylindrical body Wb is transferred to the next second stage by the transfer mechanism, and then, as shown in FIG.
The diaphragm cylinder Wc shown in FIG. The same applies to each step after FIG.

Further, although the illustration of the processing method of the flat-faced cylindrical body when the blank has an elliptical shape is omitted,
In the blanking process, a strip-shaped blank is punched out by a die including an elliptical columnar punch and a punch die in which a female die has an elliptical cross section so that the punch can be inserted. Process the blank. Next, in the next cup drawing step, the elliptical blank is drawn into a cup shape by a drawing die having an elliptical columnar drawing punch and a drawing die in which a female die has an elliptical cross section. The cup-shaped cylinder is processed.

Then, in the next redrawing process,
The oval cup-shaped cylindrical body is re-drawn by the die of the oval columnar drawing punch and the drawing die whose female cross section is formed into an oval shape to process the oval shaped cylindrical cylinder. In the subsequent steps, the redrawing process similar to that of the oval blank described above is performed to form the flat-faced cylindrical body W.

Subsequently, as to the method for processing the flat-faced cylindrical body when the blank has a circular shape, FIGS.
Will be described with reference to. FIG. 4 shows a strip-shaped material obtained by punching out a circular blank, and FIG. 5 is an explanatory view showing a working mode in which a flat-faced cylindrical body is pressed from the circular blank.

FIG. 5 (a) shows a blanking process of a press machine, which comprises a cylindrical punching punch (not shown) and a punching die in which a female die has a circular cross section so that the punching punch can be inserted. The shape of the circular blank 3 punched and processed from the strip | belt-shaped raw material 1 shown in FIG. 4 by a model is shown.

FIG. 5 (b) shows that, in the next cup drawing process, by using a die including a cylindrical drawing punch (not shown) and a drawing die in which the female die has a circular cross section,
The shape of the cup-shaped cylindrical body Wb obtained by cup-drawing the circular blank 3 shown in FIG. This cup-shaped cylindrical body Wb
The inner and outer peripheries are circular, the drawing ratio is D ₁ / D ₀ = 0.76, and the ironing ratio is t−t ₁ / t = 0, which are formed by the above mold.

FIG. 5C is a plan view of the next redrawing step, in which a cylindrical drawing punch (not shown) and a drawing die in which a female die has an oval cross section are used.
The shape of the drawn cylindrical body Wc obtained by redrawing the cup-shaped cylindrical body Wb shown in (b) is shown. The diameter ratio between the major axis A ₂ and the minor axis B ₂ on the outer peripheral side of the throttle cylinder Wc is A ₂ / B ₂ = 1.03, and the major diameter a ₂ on the inner peripheral side and the minor diameter b ₂ are a. ₂ / b ₂ = 1.
00 (that is, the shape is circular, and the circular shape is maintained except for the flat portion after this stage), the draw ratio on the major axis side is A ₂ / D ₁ = 0.77, and the draw ratio on the minor axis side. Is B ₂ / D ₁ =
0.75, the ironing rate on the major axis side is t ₁ −m ₂ / t ₁ = 0,
The ironing rate on the minor axis side is t ₁ −n ₂ / t ₁ = 0.25, and these are formed by the mold.

FIG. 5 (d) is a plan view of the next redrawing step, in which a cylindrical drawing punch (not shown) and a drawing die having a female die having an oval cross section are used to form the die shown in FIG.
A diaphragm cylinder W obtained by redrawing the diaphragm cylinder Wc shown in (c).
The shape of d is shown. The diameter ratio between the major axis A ₃ and the minor axis B ₃ on the outer peripheral side of the cup-shaped cylindrical body Wd is A ₃ / B ₃ = 1.07, and the major diameter a ₃ on the inner peripheral side and the minor diameter b ₃ are a ₃ / b ₃ = 1.
00, the draw ratio on the major axis side is A ₃ / A ₂ = 0.75, the draw ratio on the minor axis side is B ₃ / B ₂ = 0.72, and the ironing rate on the major axis side is m ₂ −m ₃ / m ₂ = 0, ironing ratio of minor axis is n ₂ -n ₃
/ N ₂ = 0.22, which are formed by the mold.

FIG. 5 (e) shows the surplus locally bulged in the opening when the re-drawing process shown in FIGS. 5 (c) and 5 (d) is pressed in the next trimming process. Therefore, the shape of the iris tube body We obtained by trimming the excess thickness is shown. The extra thickness was also described in the section of the circular blank 3 in the description of the shape of the blank described above. However, since each phase cross-sectional area of the hatched portion 5 shown in FIG. The surplus bulging in the opening of the body is not averaged, and the surplus bulging locally bulges in the intermediate step of redrawing.

FIG. 5 (f) shows, in the next redrawing process, a cylindrical drawing punch (not shown) and a drawing die in which a female die has an oval cross section.
A diaphragm cylinder W obtained by redrawing the diaphragm cylinder We shown in (e).
The shape of f is shown. Diameter ratio of the major axis A ₄ to the minor axis B ₄ of the outer peripheral side of the cup-shaped cylindrical body Wf is A ₄ / B ₄ = 1.11, diameter ratio of the major axis to a ₄ and a minor axis b ₄ of the inner peripheral side a ₄ / b ₄ = 1.
00, the reduction ratio on the major diameter side is A ₄ / A ₃ = 0.83, the reduction ratio on the minor diameter side is B ₄ / B ₃ = 0.81, and the ironing ratio on the major diameter side is m ₃ −m ₄ / m ₃ = 0, the ironing rate on the minor axis side is n ₃ -n ₄
/ N ₃ = 0.14, which are formed by the mold.

In the next redrawing process, FIG. 5 (g) shows a cylindrical drawing punch (not shown) and a drawing die in which a female die has an oval cross section.
A diaphragm cylinder W obtained by redrawing the diaphragm cylinder Wf shown in (f).
The shape of g is shown. Diameter ratio of the major axis A ₅ to the minor axis B ₅ of the outer side of the cup-shaped cylindrical body Wg is A ₅ / B ₅ = 1.09, diameter ratio of the major axis to a ₅ and a minor axis b ₅ of the inner peripheral side a ₅ / b ₅ = 1.
00, the draw ratio on the major axis side is A ₅ / A ₄ = 0.80, the draw ratio on the minor axis side is B ₅ / B ₄ = 0.81, and the ironing rate on the major axis side is m ₄ −m ₅ / m ₄ = 0.25, ironing rate on the minor axis side is n ₄
A -n ₅ / n ₄ = 0.17, which are intended to be formed by the mold.

In the next redrawing process, FIG. 5 (h) shows a cylindrical drawing punch (not shown) and a drawing die in which a female die has an oval cross section.
A diaphragm cylinder W obtained by redrawing the diaphragm cylinder Wg shown in (g).
The shape of h is shown. Diameter ratio of the major axis A ₆ to the minor axis B ₆ of the outer peripheral side of the cup-shaped cylindrical body Wh is A ₆ / B ₆ = 1.12, diameter ratio of the major axis to a ₆ to the minor axis b ₆ of the inner peripheral side a ₆ / b ₆ = 1.
00, the draw ratio on the major axis side is A ₆ / A ₅ = 0.96, the draw ratio on the minor axis side is B ₆ / B ₅ = 0.93, and the ironing rate on the major axis side is m ₅ -m ₆ / m ₅ = 0, the ironing rate on the minor axis side is n ₅ -n ₆
/ N ₅ = 0.24, which are formed by the mold.

FIG. 5 (i) shows the shape of the flat-faced cylindrical workpiece W whose opening has been cut and dimensioned by a trimming punch and die die (not shown) in the next trimming step. Indicates.

[0055]

Since the present invention is constructed as described above, it has the following effects.

Since the cylindrical portion and the flat portion are press-drawn by a drawing punch and a drawing die to reduce the diameter and extend, the flat portion is made thinner than the thickness of the cylindrical portion to form a flat surface. It is possible to mass-produce a flat-faced cylinder with high processing accuracy such as parallelism and concentricity of the flat face with respect to the central axis of the flat-faced cylinder, uneven thickness of the flat portion, and the like.

Further, even when the flat surface of the flat portion formed thinner than the wall thickness of the cylindrical portion on the outer periphery of the cylindrical body is two parallel surfaces, the cylindrical portion and the two parallel flat portions are parallel to each other. Was pressed and drawn by a drawing punch and a drawing die to reduce the diameter and extend the two parallel flat parts to be thinner than the cylindrical part to form a flat surface. The parallelism and concentricity of the two flat surfaces parallel to the central axis and the uneven thickness of the two parallel flat portions can be mass-produced with high efficiency with high accuracy.

Further, in the processing method in which the blank formed by the blank processing is formed into a circular shape, all the punches can be formed into a cylindrical shape, so that the cost of manufacturing the die can be reduced.

Further, in the processing method in which the blank formed by the blank processing is made into an elliptical shape, the radial phase cross-sectional area with respect to the plane coordinate center of the flat-faced cylinder and the radial phase cross-sectional area with respect to the plane coordinate center of the blank. Since and are made to have an approximate cross-sectional area, the excess bulge that bulges in the opening of the cylinder during redrawing is averaged, and the local excess bulge is eliminated and interference with the die set member etc. It is possible to prevent an obstacle in the press working due to the above, and to eliminate the step of trimming the locally bulged surplus in the intermediate step of redrawing.

Further, in the processing method in which the blank formed by the blank processing is made into an oval shape, the radial phase cross-sectional area with respect to the plane coordinate center of the flat-faced cylinder and the radial phase cross-sectional area with respect to the plane coordinate center of the blank. Since and are made to have an approximate cross-sectional area, the excess bulge that bulges in the opening of the cylinder during redrawing is averaged, and the local excess bulge is eliminated and interference with the die set member etc. It is possible to prevent an obstacle in the press working due to the above, and to eliminate the step of trimming the locally bulged surplus in the intermediate step of redrawing. Further, after the blank processing, the corrugated portion formed on the strip-shaped material can be made narrow, so that the material yield can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a strip-shaped material obtained by punching out an oval-shaped blank according to the present invention, and is a plan view.

FIG. 2 is an explanatory view showing a working mode of pressing a flat-faced cylindrical body from an oval-shaped blank according to the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a blank and a flat-faced cylindrical body having a final processed shape according to the present invention, and is a plan view.

FIG. 4 is an explanatory view showing a strip-shaped blank obtained by punching out a circular blank according to another embodiment of the present invention, and is a plan view.

FIG. 5 is an explanatory view showing a working mode in which a flat-faced cylindrical body is pressed from a circular blank according to another embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

1 Strip-shaped material 2 Oval blank 3 circular blank 4 Calculation blank 5 shaded area 6 flat part 7 Cylindrical part W workpiece (cylindrical body with flat surface)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 59-169631 (JP, A) JP-A 49-38272 (JP, A) JP-A 5-329559 (JP, A) JP-A 63- 194824 (JP, A) JP-A-3-210920 (JP, A) JP-A-7-226347 (JP, A) Actual Kaihei 6-48369 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21D 22/20 B21D 22/26-22/30 B21D 51/18 B21D 51/26

Claims (9)

(57) [Claims] 1. A method of processing a cylindrical body having a flat surface formed on the outer periphery of a cylindrical body, wherein the thickness of the flat portion is smaller than that of the cylindrical portion. A blank is formed by blanking with a punching die, a cup-shaped cylindrical body is formed by performing a cup drawing on the blank with a drawing punch and a drawing die, and a predetermined shape is formed by the drawing punch and the drawing die on the cup-shaped cylindrical body. A cylindrical body in which a flattened portion having a thickness smaller than the wall thickness of the cylindrical portion is formed by reducing and extending the diameter and forming a cylindrical portion and a flattened portion by redrawing a number of times and performing ironing processing in at least one step. A method for processing a cylindrical body with a flat surface, characterized by being processed. 2. The cylindrical body with a flat surface according to claim 1, wherein the flat surface of the flat portion formed on the outer periphery of the cylindrical body to be thinner than the wall thickness of the cylindrical portion is two parallel flat surfaces. Processing method. 3. A blank formed by blanking is
The method for processing a cylindrical body with a flat surface according to claim 1 or 2, which has a circular shape. 4. The blank formed by blanking is
The processing method of a flat-faced cylindrical body according to claim 2, wherein the elliptical shape and the curved portion on the minor axis side of the ellipse are arranged and processed so as to correspond to the flat portion of the formed cylinder. 5. The blank formed by blanking is
The processing method for a flat-faced cylindrical body according to claim 2, wherein the flat-shaped cylindrical body is arranged and processed so as to correspond to the flat portion portion of the cylindrical body in which the parallel linear portions having the small-sized shape are formed. 6. A mold up to an intermediate step of re-drawing processing of reducing the diameter of a drawing cylinder, extending it, making it circular, and thinning the flat portion,
Processed with a drawing punch formed into an elliptical column shape and a drawing die having an elliptical cross section of the inner periphery of the hollow hole, and the mold between the intermediate step and the final redrawing process has a cylindrical shape. 5. The cylindrical body with a flat surface according to claim 4, wherein the formed drawing punch and a drawing die in which the inner circumference of the hollow hole is formed with a flat surface portion parallel to two directions in a circular inner circumference circle. Processing method. 7. A mold up to an intermediate step of re-drawing processing of reducing the diameter of a drawing cylinder, extending it, making it circular, and thinning the flat portion,
Processing is performed with a drawing punch formed in an oval column shape and a drawing die whose inner cross section of the hollow hole is formed in an oval shape, and the mold between the intermediate process and the final redrawing process is cylindrical. 6. The cylindrical body with a flat surface according to claim 5, wherein the formed drawing punch and the drawing die in which the inner circumference of the hollow hole is formed with a flat surface portion parallel to two directions in a circular inner circumference circle. Processing method. 8. A blank for a press, which is used for processing a cylindrical body in which two flat surfaces parallel to the outer periphery of the cylindrical body are formed and the thickness of the flat portion is thinner than the thickness of the cylindrical portion. The cup-shaped tubular body is formed in an elliptical shape from a curved portion on the diameter side and a curved portion on the long diameter side connected to the curved portion on the short diameter side, and when the cup is drawn into an elliptical cup-shaped tubular body. By processing the flat part of the curved part on the short diameter side,
A blank for a press, characterized in that a surplus thickness that bulges into an opening of a cylindrical body during redrawing is averaged. 9. A blank for a press, which is used for processing a cylindrical body in which two flat surfaces parallel to the outer periphery of the cylindrical body are formed and the thickness of the flat portion is thinner than the thickness of the cylindrical portion. Formed into an oval shape from a straight linear portion and semi-circular portions connected to both ends of the parallel linear portion, and the flat portion of the cup-shaped tubular body is formed when cup-drawing into the oval-shaped tubular body. A press blank, characterized in that it is processed in the parallel linear portions so as to average the surplus bulging in the opening of the tubular body during redrawing.