JPH0768326A - Method and machine for ironing - Google Patents

Abstract

PURPOSE:To obtain a machine and method for ironing by which the stripping property is improved and products of high dimensional accuracy are obtained at the time of ironing a workpiece like a photosensitive drum for copying machines consisting of aluminum or aluminum alloy. CONSTITUTION:This machine is provided with a punch 1 which is made into a bar shape and inserted in the inside of the workpiece P, die 2 which is arranged on the outer peripheral part of the punch 1, in which the workpiece P in which the punch is inserted is inserted and with which ironing to the workpiece is executed and stopper 3 with which the base end part of the workpiece after executing ironing is locked and drawing-out of the punch l is allowed. By using the ironing machine having the punch whose surface roughness is in the range of Rmax=0.5 to 2.0mum, ironing work is executed to the workpiece consisting of aluminum or aluminum alloy, especially the photosensitive drum for copying machines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ironing method and an ironing machine suitable for ironing an aluminum workpiece.

[0002]

2. Description of the Related Art Generally, ironing is used for processing various tubular metal products because it has a uniform wall thickness and inner and outer diameters and is excellent in processing dimensional accuracy. FIG. 5 shows a conventional general ironing machine used for this type of ironing, in which reference numeral 1 is a punch. The punch 1 is of a columnar shape having an outer diameter that is the same as the inner diameter of the workpiece P, and is provided so as to be movable in the left-right direction in the drawing by a driving device (not shown). On the outer periphery of the punch 1, a plurality of stages of dies 2 (only the final stage is shown in the figure) are provided in which the raw tubes in which the punch 1 is inserted are sequentially inserted. A stopper 3 for locking the base end portion of the processed workpiece P is provided in front of the final stage die 2 so as to be movable back and forth with respect to the punch 1.

In order to perform the ironing of the workpiece P with such an ironing machine, first, with the punch 1 inserted in the elemental pipe, the elemental pipes are successively inserted through the die pipe. Then, the blank tube is sequentially ironed by the die, and is formed into a desired outer dimension by the ironing by the final die 2. Then, the punch 1 is further advanced, and as shown in FIG. 5, the work piece P is passed through the die 2 at the final stage.
Is advanced with respect to the punch 1 to lock the base end portion of the workpiece P, and then the punch 1 is moved to the right in the figure to pull out from the workpiece P (stripping). The work piece P is separated from the punch 1.

[0004]

However, when a photosensitive drum for a copying machine, which is an aluminum thin-walled tube, is processed by the above-described processing method, the aluminum thin-walled tube that is the workpiece P is inferior in strength. At the time of stripping after ironing, the base end portion of the workpiece P, which is locked by the stopper 3, is buckled and deformed by the pulling load of the punch 1, resulting in dimensional accuracy of the product, especially the most important true value. There is a problem that the circularity and cylindricity are lowered. By the way, in forming such a photosensitive drum, there is also one in which both ends of the workpiece P are cut and cut after the above-mentioned stripping. However, the dimensional accuracy of the workpiece before and after the cutting is concerned. Due to the correlation, there were similar problems.

In the processing method of performing stripping after such ironing, generally, the material characteristics of the work piece, the punch surface properties, the punch shape, the punch material, the processing temperature, the squeezing speed, and the lubricating oil are used. It is known that such factors affect the stripping property.

Therefore, the inventors of the present invention have made various studies on each of the above factors in order to improve the stripping property in the ironing process of a thin-walled tube made of aluminum such as the photosensitive drum. In the ironing process, the friction phenomenon that acts between the punch and the work piece, that is, the surface texture of the punch to which the work piece adheres,
We have come to the finding that it is a factor that exerts a particularly large influence on the stripping property.

The present invention has been made on the basis of the above findings. For example, when ironing a workpiece made of aluminum or an aluminum alloy such as the photosensitive drum, the stripping property is improved and the dimensional accuracy is high. It is an object of the present invention to provide an ironing machine and an ironing method by which a product can be easily obtained.

[0008]

SUMMARY OF THE INVENTION An ironing machine according to the present invention is a punch which is rod-shaped and is inserted into the inside of an object to be processed, and the punch which is arranged around the outer periphery of the punch and into which the punch is inserted. A die through which the work piece is inserted and irons the work piece, and a stopper that locks the base end of the work piece after the ironing work to allow the punch to be pulled out. , The surface roughness of the punch is Rma
It is characterized in that x is in the range of 0.5 μm to 2.0 μm.

The ironing method according to the present invention is for ironing a workpiece made of aluminum or an aluminum alloy, particularly a photosensitive drum for a copying machine, by using the ironing machine.

[0010]

According to the ironing machine of the present invention and the ironing method using the same, the frictional resistance between the punch and the workpiece is reduced, and the stripping load is reduced. Buckling does not occur at the base end. Therefore, a product having improved dimensional accuracy, particularly cylindricity and roundness at the base end, can be processed.

Here, the surface roughness of the punch is expressed by Rmax
The reason why the range is limited to 0.5 μm to 2.0 μm will be described. As shown in FIG.
If it is less than μm, the area of direct contact between the surface of the work piece and the punch surface increases, the frictional resistance increases, the stripping load increases, and the work piece buckles. Since it is necessary to finish the mirror surface, the manufacturing cost thereof is increased, which is inconvenient.
If the surface roughness exceeds 2.0 μm, as shown in FIG. 2, the minute projections 6 formed on the inner wall of the workpiece on the outer peripheral surface of the punch 5 when the punch 5 is pulled out as shown in FIG. Because of strong sliding, frictional resistance increases, stripping load increases, and the surface roughness of the inner wall surface of the workpiece decreases, which is inappropriate.

[0012]

[Examples] Examples carried out to confirm the effects of the present invention will be described below. First, the respective surface roughnesses are Rmax = 0.5 μm, 1.0 μm, 1.5 μm, 2.
A plurality of punches having a diameter of 0 μm and 2.5 μm were sequentially attached to the ironing machine, and the diameter of each of the workpieces was 64.7.
An aluminum thin-walled tube for a photosensitive drum having a thickness of 3.0 mm and a plate thickness of 3.0 mm was ironed at a reduction rate of 62.3%. Then, after the ironing of the work piece, stripping was performed at stripping speeds of 4 mm / s and 8 mm / s, respectively.

FIG. 3 shows the relationship between the surface roughness of each punch in the above embodiment and the roundness at the base end of the obtained workpiece. Further, FIG. 4 shows the relationship between the punch surface roughness in the above embodiment and the surface roughness on the inner surface of the obtained workpiece. As is clear from these results, the surface roughness is Rmax = 0.5 μm-2.
It can be seen that by performing ironing and stripping with a punch in the range of 0 μm, a product having a high roundness at the base end and a good inner surface roughness can be obtained.

Therefore, according to the ironing machine having the punch having the surface roughness within the above range and the ironing method using the punch, the workpiece to be machined of aluminum or aluminum alloy such as a photosensitive drum having a particularly poor mechanical strength is used. Even if stripping is performed on objects, the roundness of the base end is high,
In addition, it is possible to easily manufacture a product having excellent surface roughness on the inner surface, which greatly improves the manufacturing yield, and in the case of manufacturing the photosensitive drum or the like of the type that cuts both ends, it is possible to reduce the cut portion. It is economical to do.

[0015]

As described above, the ironing machine according to the present invention has a punch which is rod-shaped and is inserted into the inside of the workpiece, and the punch which is disposed on the outer peripheral portion of the punch and has the punch inside. A die through which the inserted workpiece is inserted to perform ironing processing on the workpiece, and a stopper that locks the base end portion of the workpiece after the ironing processing and allows the punch to be pulled out. The surface roughness of the punch is in the range of Rmax = 0.5 μm to 2.0 μm, and the ironing method according to the present invention uses the ironing machine described above. , A workpiece made of aluminum or aluminum alloy, especially a photosensitive drum for copying machines, is ironed, so even if stripping is performed after ironing, the roundness of the base end is high and the inner surface is high. Surface of It is possible to easily manufacture products with excellent roughness, greatly improving the manufacturing yield, and
Even in the case of manufacturing the above-described photosensitive drum of the type in which both ends are cut, the cut portion can be reduced, which is economical.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between punch surface roughness and stripping load according to an ironing apparatus and a method for ironing of the present invention.

FIG. 2 is a side sectional view showing a state of a punch surface and an inner surface of a workpiece during stripping.

FIG. 3 is a diagram showing a relationship between punch surface roughness and roundness of a base end portion of a workpiece in a result of an example of an ironing method of the present invention.

FIG. 4 is a diagram showing the relationship between the punch surface roughness and the surface roughness of the inner surface of the workpiece in the result of the embodiment of the ironing method of the present invention.

FIG. 5 is a schematic configuration diagram showing a conventional ironing machine.

FIG. 6 is a schematic configuration diagram showing a state of stripping in a conventional ironing machine.

[Explanation of symbols]

 1,5 Punch 2 Dice 3 Stopper

Claims (3)

[Claims] 1. A work piece made of aluminum or an aluminum alloy having a cylindrical shape, which is attached to the outer circumference of a punch having a rod shape, is inserted between dies smaller than the outer dimension of the work piece to perform ironing, and then the work piece is formed. In the ironing method in which the base end of an object is locked by a stopper, and then the punch is pulled out to separate the punch from the workpiece, the surface roughness of the punch surface is Rmax = 0.5 μm
An ironing method characterized by having a range of 2.0 μm. 2. The ironing method according to claim 1, wherein the workpiece is a photosensitive drum for a copying machine. 3. An ironing machine for ironing a workpiece made of aluminum or an aluminum alloy, comprising a punch having a rod shape and inserted into the inside of the workpiece, and an outer peripheral portion of the punch. , A die into which the work piece having the punch inserted thereinto is inserted to perform ironing processing on the work piece, and a base end portion of the work piece after the ironing processing is locked to lock the punch. An ironing machine, comprising a stopper that allows drawing, and the surface roughness of the punch is in the range of Rmax = 0.5 μm to 2.0 μm.