JP2002192242A - Workpiece processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for thinning a workpiece without adding to the workpiece such great compression force from the punch of a press and so on as in a conventional method, when forming a product of the same shape as the workpiece by making the given part of the workpiece thinner than the other part of the workpiece. SOLUTION: The workpiece processing method for forming the product of the same shape as the workpiece having thin part 41a by thinning the given part 11a of the workpiece 10 comprises a thinning step which forms swelling part 36a which is thinner than other part 11b by adding pulling force to the given part 11a of the workpiece, and a flattening step which flattens the swelling part 36a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing the thickness of a work, and more particularly, to reducing the thickness of a predetermined portion of the work to be smaller than the thickness of the remaining portion, and having the same shape as a work having a thin portion in part. And a method for reducing the thickness of a workpiece forming a processed product.

[0002]

2. Description of the Related Art There is a case where it is desired to reduce the thickness of a predetermined portion of a work to be smaller than the thickness of the remaining portion to form a processed product having a thin portion in the same shape as the work. For example, from a disk-shaped work 90 shown in FIG. 4A to a disk-shaped semi-finished product 92 shown in FIG.
In this case, a disk-shaped processed product 95 shown in FIG. Conventionally, for reducing the thickness of the work 90, for example, FIG.
(A) First die 100 and first punch 103
And the second die 107 and the second punch 1 shown in FIG.
10 were used.

That is, the first die 10 shown in FIG.
No. 0 has a circular protruding portion 101 formed at the center of the upper surface, and has a circular die surface 102a and an annular die surface 102b. The first punch 103 has a projecting portion 104 formed on the lower surface, and has a circular punch surface 105a and an annular punch surface 105b.
And

When the work 90 is set on the first die 100 and the first punch 103 is lowered, in FIG. 4 (a), the work 90 has a die surface 102a and a ring surface 102a having lower and upper surfaces of a center portion 91a. The compressive force is applied from both sides by the punch surface 105a. As a result, the work 90
The material of the central portion 91a moves outward in the radial direction, and its thickness gradually decreases. Accordingly, the outer diameter of the outer peripheral portion 91b increases. Thus, as shown in FIG. 4B, a disk-shaped semi-finished product 92 in which a circular thin portion 93a is formed at the center and an annular thick portion 93b is formed at the outer periphery is obtained.

The blank 92 is further thinned by the second die 107 and the second punch 110 shown in FIG. The second die 107 has a circular projection 108 formed at the center of the upper surface, and has a circular die surface 109a and an annular die surface 109b. The second punch 110 has a circular protruding portion 111 formed on the lower surface, and has a circular punch surface 1.
12a and an annular punch surface 112b. Projection 1
The outer diameters of 08 and 111 are larger than the outer diameters of the protruding portions 101 and 104, and the amount of protrusion is made substantially equal to these amounts of protrusion.

[0006] As the second punch 110 is lowered, the material of the inner peripheral edge of the thick portion 93b of the blank 92 is moved radially outward by the annular die surface 109a and the annular punch surface 112a to form the thin portion 93a. The thickness is reduced to the same thickness, and the size (outer diameter) of the thin portion 93a increases. Along with this, the radially intermediate portion and the outer peripheral portion of the thick portion 93b are displaced outwardly in the radial direction and the outer diameter increases. Thus, FIG.
As shown in (c), a circle having a circular thin-walled portion 96a having a predetermined thickness and a predetermined diameter at a central portion, and an annular thick-walled portion 96b having a predetermined thickness and a predetermined inner diameter and outer diameter at an outer peripheral portion. A plate-shaped processed product 95 is formed.

[0007]

However, the conventional method for making the work 90 thinner has the following problems. That is, in this thinning method, the central portion 91a of the work 90 is crushed by applying a compressive force from the annular die surface 102a and the annular punch surface 105a, and the inner peripheral edge of the thin portion 93a of the blank 92 is formed into the annular die surface 109a. And annular punch surface 112a
This is to apply more compressive force to crush. In this case, the contact area between the central portion 91a of the work 90, the annular die surface 102a, and the annular punch surface 105a is large, and the inner peripheral edge of the thin portion 93a of the blank 92, the annular die surface 109a, and the annular punch surface The contact area with 112a is also large.

Therefore, when forming the semi-finished product 92 from the workpiece 90 and when forming the processed product 95 from the semi-finished product 92, on the press side, it is necessary to crush the central portion 91a and the thin portion 93a of the workpiece 90. It is necessary to apply a large driving force to the first punch 103 and the second punch 110. As a result, the first punch 103 and the second punch 110
The drive source for driving the drive becomes large, and the press becomes large. Further, the protrusion 104 of the first punch 103 and the second
The projecting portion 111 (particularly the edge) of the punch 110 may be broken or damaged by the large compressive force. If the protrusions 104 and 111 are lost in a short period of time, the cost for forming the processed product 95 from the work 90 through the semi-processed product 92 increases.

On the other hand, on the work 90 side, the work 9
0 and the semi-finished product 92 undergo work hardening when a compressive force is applied by the first punch 103 and the second punch 110,
Its properties become brittle and the toughness decreases. In this case, it is impossible to form the processed product 95 that requires particularly large toughness.

The present invention is based on the above circumstances, and when forming a workpiece having the same shape as the work by making a predetermined portion of the work thinner than the rest of the work, a press punch or the like is used when the work is made thinner. An object of the present invention is to provide a method for reducing the thickness of a work in which a large compression force is not applied to the work as in the related art.

[0011]

SUMMARY OF THE INVENTION The inventor of the present invention applies a tensile force to a predetermined portion of a work when the work is made thinner than the remaining portion to form a workpiece having the same shape as the work. And completed the present invention. That is, the present invention is a method of processing a work in which a predetermined portion of the work is thinned to form a processed product having the same shape as the work having a thin portion in part, wherein a tensile force is applied to the predetermined portion of the work. And a flattening step of flattening the bulging portion to form a bulging portion thinner than the remaining portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A work processing method according to the present invention can take the following embodiments. <Work> The shape of the work is not particularly limited, and may be a rod shape or a plate shape. For example, the plate-shaped work can be rectangular or circular. The thickness of the work is not particularly limited,
The whole (predetermined portion and other remaining portions) may have a uniform thickness, or the predetermined portion and the remaining portion may have different thicknesses.

The position of the predetermined portion of the work on the work is not particularly limited, and may be located at an intermediate portion or an end in the longitudinal direction and the radial direction of the work. The shape of the predetermined portion of the workpiece is not particularly limited, but is preferably line-symmetric or point-symmetric. As an example of the predetermined portion which is line-symmetric, there is a pair of band-like portions which are located symmetrically with respect to the center line at the center in the width direction of the rectangular work and extend in the length direction. Examples of the point-symmetric predetermined portion include a circular portion or a polygonal portion formed at the center of a circular or polygonal work, and an annular portion or a frame-shaped portion formed around the center of the work. <Thinning Step> In the thinning step, a tensile force is applied to a predetermined portion of the work to form a bulged portion thinner than the remaining portion.
The direction in which the tensile force is applied is not particularly limited. Specifically, the pulling direction can be determined in relation to the shape and position of a predetermined portion of the work, for example, a cylindrical punch having a spherical punch surface and moving in the thickness direction of the work, or a circular arc surface in cross section A cylindrical punch having an annular punch surface and moving in the thickness direction of the workpiece can be applied in a tangential direction of the punch surface.

The shape and direction of the bulging portion are not particularly limited, but are actually determined by the shape of the punch surface of the punch and the amount of movement of the punch. When the predetermined portion of the work is reduced in thickness, it is desirable that the remaining portion be held by a holding member such as a die or a wrinkle holding member. <Planarization Step> The flattening step flattens the bulging portion.
In order to flatten the bulging portion, a compressive force can be applied to the bulging portion in the thickness direction by a pressing member such as a die. In the flattening step, flattening can be performed while regulating the thickness of the swollen portion, whereby the thickness of the thinned swollen portion can be prevented from fluctuating during flattening. The length and diameter of the swollen portion of the work changes due to flattening, and the position of the remaining portion changes.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. <First Embodiment> FIGS. 1A, 1B, 1C and 1D show a first embodiment of the present invention. In this manner, similarly to the case shown in FIG. 4, a disk-shaped blank 35 is formed from the first die 15 and the first punch 20 from the disk-shaped work 10 (FIGS. 1A and 1B). b)), and a disk-shaped processed product 40 is formed by the second die 25 and the second punch 30 (see FIGS. 1C and 1D). Thinning Step As shown in the left half of FIG. 1 (a), the entire disk-shaped work 10 having a predetermined diameter has a uniform thickness. FIG. 1A shows the left half of the first die 15 and the left half of the first punch 20 used in the thinning step.
The first die 15 has a cylindrical shape having a predetermined inner diameter and an outer diameter, and has an annular first die surface 16 on an upper surface thereof.

An annular wrinkle holding member 18 is arranged above the first die. The wrinkle holding member 18 has an inner diameter and an outer diameter substantially equal to those of the first die 15, and has an annular wrinkle holding surface 19 facing the first die surface 16 on a lower surface thereof. The wrinkle holding member 18 is urged downward from behind (above) by the compression spring 17.

The first die 15 is vertically approached.
The separated first punch 20 has a cylindrical shape, and its outer diameter is made substantially equal to the inner diameter of the wrinkle holding member 18. First
The lower surface of the punch 20 has a spherical first
A punch surface 21 is formed.

When the thickness of the work 10 is reduced, the work 10 is placed on the first die surface 16 of the first die 15 as shown in FIG. The outer peripheral portion 11b is sandwiched from above and below. After that, when the first punch 20 is lowered, a tensile force is applied in a tangential direction to the center of the center 11a of the work 10 by the top of the first punch surface 16 as the descent moves, and the center 11a is separated by a portion away from the top. A tangential tensile force is applied to a portion away from the center. When the first punch 20 is lowered, the compression spring 17 compresses and applies a large pressing force to the wrinkle pressing member 18, and the outer peripheral portion 11 b of the work 10 is strongly held between the first die surface 16 and the wrinkle pressing surface 19. .

The pulling force of the first punch surface 21 to the center portion 11a of the work 10 is determined by the tangential direction of the first punch surface 21,
That is, it is applied obliquely downward at a predetermined angle with respect to the first die surface 16. As a result, as shown in the right half of FIG.
1 and a dome-shaped bulging portion 36a (FIG. 1)
(See (c)), and the thickness thereof is reduced. At this time, the outer diameter and thickness of the outer peripheral portion 11b of the work 10 hardly change.

In this thinning step, the spherical first punch surface 21 of the first punch 20 and the flat central portion 1 of the workpiece 10 are formed.
The area of the abutting portion where the abutment 1a abuts is small and the surface pressure is high. Accordingly, the conventional punches 103 and 11 are attached to the first punch 20.
There is no need to apply a large driving force such as 0, and the driving source can be reduced. In addition, since the spherical first punch surface 21 has no corner, there is no risk of loss or breakage in conjunction with the miniaturization of the drive source. Further, the work 1 whose central portion 11a is subjected to a tensile force by the first punch surface 21
In the case of No. 0, since no compressive force is applied as in the conventional works 103 and 110 shown in FIG. 4, almost no work hardening occurs during thinning. This is particularly significant when manufacturing a processed product 40 requiring toughness.

This thinning step is common to (deep) drawing, which is a type of press working, in that the work is thinned by applying a tensile force to a part of the work. However, this embodiment is different from the (deep) drawing in that the material of the outer peripheral portion 11b of the work 10 does not flow into the central portion 11a when the thickness is reduced. Flattening Step The left half and the second half of the second die 25 used in the flattening step
The left half of the punch 30 is shown in FIG. 2nd die 2
In the center of the upper surface of the upper surface 5, a circular protrusion 26 slightly protruding upward is formed, whereby the circular second die surface 2 is formed.
7a and an annular third die surface 27b are formed. At the center of the upper surface of the second punch 30, the protruding portion 26 is provided.
A circular protruding portion 31 protruding downward by the same degree as the above is formed, thereby forming a circular second punch surface 32a and an annular third punch surface 32b. Both protrusions 2
6 and 31 are equal in outer diameter, so that the second die surface 27a
And the second punch surface 32a have the same diameter.

In the flattening step, as shown in FIG. 1C, the semi-finished product 35 on which the bulging portion 36a has been formed in the thinning step is placed on the second die surface 27a of the second die 25. Then, the second punch 30 is lowered. Then, as it descends, an axial compressive force is applied to the bulging portion 36a by the second die surface 27a and to the outer peripheral portion 36b by the third punch surface 32b, so that the bulging portion 36a approaches the outer peripheral portion 36b. Is deformed (recessed). with this,
The bulging portion 36a is gradually flattened and the radial dimension increases.

Then, as shown in the right half of FIG. 1 (d), when the second punch 30 is lowered to the final position, the bulging portion is completely flattened and located on the same plane as the outer peripheral portion 36b. At this time, the bulging portion 36a is compressed from both sides by the second die surface 27a and the second punch surface 32a to regulate the thickness and the outer diameter, and the outer peripheral portion 36b is connected to the third die surface 27a.
b and the third punch surface 32ba compress it from both sides to regulate its thickness, inner diameter and outer diameter. Due to the flattening of the bulging portion 36a, the outer peripheral portion 36b is displaced radially outward and its outer diameter increases.

In this manner, the entire blank 3 is completely flattened, and a circular thin center portion 41a having a predetermined outer diameter and thickness is formed at the center, and an annular thick wall having a predetermined outer diameter and thickness is formed on the outer periphery. The disk-shaped processed product 40 in which the portions 41b are respectively formed is completed.

The flattening step is performed by applying a compressive force to the predetermined portion 11a of the work 10 in terms of applying a compressive force to the center portion 91a of the work 90 and the thin portion of the semi-finished product 92 in the conventional example shown in FIGS. Common to compression (crushing) of 93a. However, this embodiment is different from the conventional example in that the crushing amount of the predetermined portion 11a of the work 10 is extremely smaller than the crushing amount of the thin portion 93a. <Second Embodiment> FIGS. 2A, 2B and 2C show a second embodiment of the present invention. In the second embodiment, an annular thin portion 92 is formed at an intermediate portion in the radial direction from a disk-shaped work (not shown) through a semi-finished product 75 (see FIG. 2A), and a center portion and an outer periphery are formed. A processed product 90 (see FIG. 2C) in which thick portions 91 and 93 are respectively formed in the portions. Thinning Step The thinning of the workpiece to the semi-finished product 75 is performed by a press including the first die 55, the first punch 70, and the wrinkle holding members 61 and 65 shown in the left half of FIG. The first die 55 has a cylindrical first die portion 56 located at the center.
And a cylindrical second die portion 58 located around the periphery. On the upper surface of the first dice portion 56, a first dice surface 57 formed of a circular flat surface 57a on the center side and an annular curved surface 57b which becomes lower toward the outer side on the peripheral side is formed. On the upper surface of the second die portion 58, a second die surface 59 is formed, which includes an annular flat surface 59a near the outer periphery and an annular curved surface 59b that becomes lower toward the inside near the inner periphery.

The wrinkle holding members 61 and 65 include a cylindrical first wrinkle holding portion 61 disposed above the first die portion 56 and an annular second wrinkle disposed above the second die 58 portion. And a holding portion 65. First wrinkle holder 61
The second wrinkle holding portion 65 has an inner diameter and an outer diameter substantially equal to those of the first die portion 56 and the second die portion 58. The first wrinkle holding portion 61 and the second wrinkle holding portion 65 have wrinkle holding surfaces 62 and 66 on their lower surfaces, respectively, and are urged downward from behind by compression springs 63 and 67, respectively.

The first punch 70 has a cylindrical shape, the inner diameter of which is substantially equal to the outer diameter of the first wrinkle holder 61, and the outer diameter of which is approximately equal to the inner diameter of the second wrinkle holder 65. An annular first punch surface 71 having a semicircular cross section is formed on the lower surface of the first punch 70.

To reduce the thickness of the work, the work is placed on the first die surface 57 of the first die portion 56 and the second die surface 59 of the second die portion 58, and the first die surface 57 and the second die surface are placed. 59 and the wrinkle holding surface 62 and the wrinkle holding surface 66 cooperate to hold the inner and outer peripheral portions from above and below. Thereafter, when the first punch 70 is lowered, the first punch surface 71
A tensile force is applied to the central portion of the radially intermediate portion of the work by the top portion, and a tensile force is applied to a portion away from the central portion by a portion away from the top portion. When the first punch 70 is lowered, the compression springs 63 and 67 are compressed to apply a large pressing force to the first wrinkle pressing portion 61 and the second wrinkle pressing portion 65, and the clamping force of the center portion and the outer peripheral portion of the work is reduced. Increase.

The pulling force of the first punch surface 71 to the intermediate portion in the radial direction is tangential to the first punch surface 71, that is, the first die surface 57 of the first die portion 56 and the second die surface of the second die portion 58. It is applied in an oblique direction that forms a predetermined angle with respect to 59. As a result, as shown in FIG. 2A, the intermediate portion in the radial direction of the work is deformed into an annular bulging portion 76b having a semicircular cross section following the surface shape of the first punch surface 71, and has a small thickness. Become. At this time, the central portion 76a and the outer peripheral portion 7
The thickness, inner diameter and outer diameter of 6c hardly change. Thus, a disk-shaped semi-finished product 75 is formed from the disk-shaped work.

In this thinning step, the first punch surface 71 having a semicircular cross section of the first punch 70 and the radially intermediate portion of the work abut on a contact portion having a small area, and the surface pressure of the contact portion is reduced. high. Therefore, the driving force applied to the first punch 70 can be small, and the driving source can be reduced. Further, since the first punch surface 71 has no corner, there is no risk of loss or breakage. Furthermore, work hardening hardly occurs at the time of thinning of a work to which a tensile force is applied along the first punch surface 71 at a radially intermediate portion and a compressive force cannot be applied.

The thinning step is common to (deep) drawing, which is a type of press working, in that the work is partially thinned by applying a tensile force to a part. However, this embodiment is different from the (deep) drawing in that the material of the central portion and the outer peripheral portion of the work does not flow into the radially intermediate portion when the thickness is reduced. Flattening Step FIG. 2B shows the left half of the second die 80 and the left half of the second punch 85 used in the step of flattening the semi-finished product 75 into the processed product 90. An annular protruding portion 81 slightly protruding upward at a radially intermediate portion of the upper surface of the second die 80
Is formed, whereby a circular third die surface 8 at the center is formed.
2a and an annular fourth die surface 82b at a radially intermediate portion
And an annular fifth die surface 82c at the outer periphery. An annular projection 86 protruding downward is formed at a radially intermediate portion of the lower surface of the second punch 85, whereby a circular second punch surface 87a at the center and an annular third punch at the radially intermediate portion are formed. A surface 87b and an annular fourth punch surface 87c at the outer periphery are formed. The inner and outer diameters of both projections 81 and 86 are equal, and therefore, the fourth die surface 82b and the third punch surface 87b have the same radial dimension (width).

As shown in FIG. 2B, the blank 75 on which the annular bulge 76b is formed is placed on the fourth die surface 82b of the second die 80, and the second punch 85 is Lower it. Then, as it descends, the bulging portion 82b has the fourth
The central portion 76a and the outer peripheral portion 76c are formed by the die surface 82b.
The second punch surface 87a and the fourth punch surface 87c apply an axial compressive force, respectively, so that the bulging portion 76b is deformed so as to approach the central portion 76a and the outer peripheral portion 76c. Accordingly, the bulging portion 76b is gradually flattened and its radial dimension increases.

When the second punch 85 descends to the final position, the bulging portion 76b is completely flattened and the central portion 76b is lowered.
a and the outer peripheral portion 76c. Bulge 7
6b is compressed from both sides by the fourth die surface 82b and the third punch surface 87b, and its thickness, inner diameter and outer diameter are regulated. The center portion 76a is compressed from both sides by the third die surface 82a and the second punch surface 87a to regulate the thickness and outer diameter, and the outer peripheral portion 76c is compressed from both sides by the fifth die surface 82c and the fourth punch surface 87c. Thickness, inside diameter and outside diameter are regulated. Due to the flattening of the bulging portion 76b, the outer peripheral portion 76c is displaced radially outward, and the outer diameter increases.

In this manner, the entire blank 75 is completely flattened, and as shown in FIG. 2C, a thick portion 91 having a circular center and a predetermined outer diameter and thickness is formed at a radially intermediate portion. A thin portion 92 having a predetermined inner and outer diameter and a predetermined thickness,
An annular thick part 93 having predetermined inner and outer diameters and a predetermined thickness is formed on the outer periphery, and a disk-shaped processed product 90 is completed.

The flattening step is different from that of the prior art shown in FIGS. 3 and 4 in that the central portion 91a and the semi-finished product 92 of the conventional example shown in FIGS. In common with the compression (crushing) of the thin portion 93a. However, this embodiment is different from the conventional example in that the swelling amount of the bulging portion 76b of the semi-finished product 75 is extremely smaller than the crushing amount of the thin portion 93a.

[0036]

As described above, in the work processing method of the present invention, a large compressive force is not applied to a work from a punch or the like in a thinning process, but only a tensile force is applied. Therefore, not only can the driving source such as the punch be reduced in size, but also the punch and the like are unlikely to be damaged or damaged.
Further, a processed product having a thin portion formed by flattening a bulging portion of a work is small in brittleness and excellent in toughness.

[Brief description of the drawings]

1A and 1B show a first embodiment of the present invention, in which FIG. 1A shows a state before machining a workpiece, FIG.
(C) is a front cross-sectional view (left half or right half not shown) of the semi-finished product before processing, and (d) is a state of the semi-finished product after processing.

FIGS. 2A and 2B show a second embodiment of the present invention, in which FIG. 2A is a front sectional view showing a state after machining of a workpiece, and FIG. (Illustration omitted), (c) is a front sectional view of a processed product.

FIGS. 3A and 3B show one of conventional examples, in which FIG. 3A is a front sectional view showing a state after processing a workpiece, and FIG. 3B is a front sectional view showing a state after processing a semi-finished product (left half or right half is not shown); ).

FIG. 4 (a) shows a work in the above conventional example,
(B) is a perspective view showing a semi-processed product, and (c) is a perspective view showing a processed product.

[Explanation of symbols]

10: Work 35; 75: Semi-finished product 40; 9
0: processed product 15; 55: die for thinning 16; 57, 59; die surface 20; 70: punch for thinning 21; 71: punch surface 25; 80: dice for flattening 26a, 26b; 82a, 82b, 82c: die surface 30; 85: flattening punch 32a, 32b; 87a, 87b, 87c: punch surface

Claims (5)

[Claims] 1. A method of processing a work, wherein a predetermined portion of the work is thinned to form a workpiece having the same shape as the work having a thin portion in part, wherein a tensile force is applied to the predetermined portion of the work. And a flattening step of flattening the bulging portion, the bulging portion being thinner than the remaining portion. 2. The work processing method according to claim 1, wherein in the thinning step, the tensile force is applied to a predetermined portion of the work in a direction making a predetermined angle with the surface. 3. The work processing method according to claim 1, wherein in the thinning step, the bulging portion is formed in a central portion of the work in a circular or polygonal shape and protrudes in a thickness direction thereof. 4. The method of processing a work according to claim 1, wherein the thinning step includes forming the bulge portion in the work in an annular or frame shape and projecting in a thickness direction thereof. 5. The method according to claim 1, wherein the flattening step applies a compressive force to the bulging portion in a thickness direction thereof.