JP2008161891A - Drawing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drawing method capable of controlling the inside diameter of a drawn product with high accuracy by a simple apparatus. <P>SOLUTION: In the drawing method, a tubular material W is drawn through a space between a drawing die 2 and a drawing plug 3. The drawing rate is controlled so that the final rate when the drawing is completed is higher than the initial rate when the drawing is started by increasing the drawing rate during the drawing work from the start of the drawing to the completion of the drawing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drawing method and related technology in which a pipe material such as an aluminum pipe is drawn through a gap between a drawing die and a drawing plug.

  The drawing method is a method in which a pipe material (work) such as an aluminum pipe is drawn through a drawing die.

  The drawing tube (drawing product) obtained by such drawing processing is used as a substrate for a photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer, or a facsimile, for example. High dimensional accuracy is required as well as surface quality.

  On the other hand, in the drawing technology in recent years, the length of the drawn tube has been increased in order to improve productivity. However, if the drawing length is increased, variations such as diameter and thickness are likely to occur, and it is difficult to maintain high dimensional accuracy. In particular, since the drawing tube for the photosensitive drum substrate requires extremely high dimensional accuracy, it is difficult to lengthen the drawing tube even if quality control is performed frequently.

Under such a technical background, Patent Document 1 discloses that when performing a drawing process, the tube material immediately after passing through a drawing die is washed, and then the outer diameter of the tube material is measured. Based on the measurement result, the drawing speed is measured. A method of controlling the outer diameter of the drawn tube by adjusting the diameter is used.
JP 2004-283864 (Claims, FIGS. 3 and 5)

  However, in the conventional drawing method shown in Patent Document 1, in addition to the measuring device that measures the outer diameter of the pipe material after passing through the die, there are a large number of devices such as a cleaning device that cleans the pipe material and a feedback device that feeds back the measurement results. The above-mentioned apparatus is necessary, and the production facilities are increased in size and complexity, and the cost is increased.

  Furthermore, in the drawing method of the same document, the outer diameter dimensional accuracy of the drawn product is improved. However, in the photosensitive drum base constituted by the drawn product, the fitting relationship with other members is important, and the outer diameter is increased. There is a strict need to manage the inner diameter rather than the dimensions. However, the drawing method disclosed in Patent Document 1 does not directly manage the inner diameter dimension but manages the outer diameter dimension, so that it is difficult to improve the inner diameter dimension accuracy.

  This invention is made in view of said subject, and it aims at providing the drawing process method and its related technique which can manage the internal-diameter dimension of drawing products with high precision with simple equipment. .

  In order to achieve the above object, the present inventor conducted a detailed investigation from every angle while paying attention to the inner diameter dimension of the drawn product in the drawing method, and found that the inner diameter of the drawn product and the drawing speed were close. It turns out that there is a good relationship.

  As a result of repeated in-depth experimental research, the present inventor found that when the drawing speed from the start of drawing to the end of drawing was constant, the inner diameter at the beginning of drawing (the tip of the drawn product) was more at the end of drawing (after the drawn product). It was clarified that the inner diameter of the edge was larger. Through further diligent efforts, we found a specific relationship between the drawing speed and the pipe inner diameter, and obtained knowledge that the pipe inner diameter can be managed with high accuracy by controlling the drawing speed during the drawing process. .

  Based on the above research results, the present inventor has found an optimum configuration capable of achieving the above object, and has completed the present invention. That is, the gist of the present invention is as follows.

[1] A drawing method in which a pipe material is drawn through a gap between a drawing die and a drawing plug,
The drawing is characterized in that the final drawing speed at the end of drawing is controlled to be higher than the initial drawing speed at the start of drawing by increasing the drawing speed during drawing from the start to the end of drawing. Processing method.

  In the present invention, the “initial drawing speed” is a speed at which the front end position (tip position) is drawn in the effective length range used as a product in the drawn pipe material. Further, the “final drawing speed” is a speed at which a rear end position (base end position) is drawn out of an effective length range used as a product in a drawn pipe material.

  The terms “drawing start” and “drawing end” are also used on the basis of the effective length range used as a product in the drawn pipe material.

  [2] The drawing method according to item 1, wherein the final drawing speed is set to 1.5 to 3.0 times the initial drawing speed.

  [3] The drawing method according to item 1 or 2, wherein the drawing speed during drawing is continuously increased at a constant rate.

  [4] The drawing method according to item 1 or 2, wherein the drawing speed during drawing is increased stepwise.

  [5] The drawing method according to any one of items 1 to 4, wherein the initial drawing speed is set to 15 to 25 m / min.

  [6] The drawing method according to any one of items 1 to 5, wherein the final drawing speed is set to 35 to 60 m / min.

  [7] The drawing method according to any one of items 1 to 6, wherein an aluminum pipe made of aluminum or an alloy thereof is used as the pipe material.

  [8] A drawn product manufactured by the drawing method according to any one of 1 to 7 above.

  [9] The drawn product according to item 8, wherein a difference in inner diameter between the front end and the rear end is adjusted to 3 μm or less.

[10] Drawing die,
A drawing plug arranged corresponding to the die hole of the drawing die;
Tube material gripping means for gripping the tip of the tube material passed through the gap between the drawing die and the drawing plug;
A drawing direction moving means for moving the tube gripping means in the drawing direction;
Pulling is started by controlling the driving of the drawing direction moving means, moving the tube gripping means in the drawing direction to perform drawing processing, and increasing the drawing speed during drawing from the start of drawing to the end of drawing. A drawing speed control means for making the final drawing speed at the end of drawing higher than the initial drawing speed at the time.

  According to the drawing method of the invention [1], since the drawing speed is increased, the problem that the inner diameter of the drawing tube becomes larger at the end of drawing than at the start of drawing can be solved. The inner diameter of the tube can be managed with high accuracy.

  Furthermore, the present invention can improve the dimensional accuracy of a drawn product simply by increasing the drawing speed during drawing, so that, for example, many other devices are not required, and the equipment can be made compact and compact accordingly. .

  According to the drawing method of the inventions [2] and [3], the above effects can be obtained more reliably.

  According to the drawing method of the invention [4], the drawing speed can be easily controlled.

  According to the drawing method of the inventions [5] and [6], the above effects can be obtained more reliably.

  According to the drawing method of the invention [7], a tubular drawn product made of aluminum can be obtained.

  The inventions [8] to [11] specify the drawn product obtained by the above-described inventive method, and thus can obtain the same effects as described above.

  The invention [12] specifies the drawing apparatus capable of performing the above-described invention method, and thus can obtain the same operation and effect as described above.

  1 and 2 are views showing an aluminum tube drawing apparatus according to an embodiment of the present invention. As shown in the drawing, the drawing apparatus includes a drawing die (2) and a drawing plug (3) disposed in a die hole (21) of the drawing die (2), and the die hole (21). An annular forming gap is formed between the plug and the extraction plug (3). And the aluminum pipe (W) as a workpiece | work (pipe material) is processed by being extracted through this shaping | molding clearance gap.

  In the present embodiment, the description will be made assuming that the conveyance direction of the aluminum tube (W) (the right direction in FIG. 1) is “front”.

  The drawing die (2) is provided in the die frame (12) of the base frame (1), and the die hole (21) is arranged on the conveyance path of the aluminum tube (W) as a work (tube material). Yes.

  The extraction plug (3) disposed in the die hole (21) is supported by the plug rod (31). That is, the plug rod (31) is arranged along the conveyance path of the aluminum tube (W), and the base end is fixed to the plug frame (13) of the base frame (1), and the plug rod The extraction plug (3) is fixed to the tip of (31).

  On the downstream side (front side) of the die frame (12), a rail (51) is laid on the base frame (1) along the drawing direction of the aluminum pipe (W). A puller (5) is attached to be able to run freely.

  A chuck (4) is attached to the puller (5), and the tip of the aluminum tube (W) can be gripped by the chuck (4).

  A winding device (6) is installed in front of the puller (5). Further, one end of a chain (61) is attached to the front surface of the puller (5), and the other end of the chain (61) is wound around the winder (6). When the winder (6) is driven and the chain (61) is wound with the chuck (4) gripping the aluminum tube (W), the puller (5) and the chuck (4) are moved forward. And the aluminum pipe (W) is drawn.

  In the present embodiment, the winder (6) is configured to be able to change the winding speed during the drawing process, and the drawing speed can be freely changed by changing the speed. It has become.

  In this embodiment, the chuck (4), the puller (5) and the like constitute the tube material gripping means, and the drawing direction moving means is constituted by the winder (6) including the chain (61). .

  The drawing apparatus of the present embodiment includes a control device (7) configured by a personal computer or the like, and the control device (7) is a drive unit of the winder (6) according to a preset program. The operations described later are automatically performed by controlling the driving of each driving unit of the drawing apparatus including the above. As will be described later, this control operation includes an operation of changing the drawing speed during the drawing process, and the function (program) of the control device (7) for performing this speed changing operation is the drawing speed. It constitutes a control means.

  Next, the operation in the drawing apparatus of this embodiment will be described. First, in a state where the aluminum pipe (W) is set, the plug rod (31) is disposed along the axis inside the pipe, and the tip of the aluminum pipe (W) is connected to the drawing die (2) and the drawing plug (3). It is inserted into the gap for molding process between and held by the chuck (4). In addition, the puller (5) is arrange | positioned in the position (retreat position) which approached the drawing die (2) as shown by the imaginary line of FIG.

  When an operation start command is given to the control device (7) in this state, the winder (6) is driven to wind the chain (61), and the puller (5) travels forward. Thereby, the aluminum pipe (W) gripped by the chuck (4) passes through the machining gap between the drawing die (2) and the drawing plug (3), and drawing is performed.

  Here, in this embodiment, while the aluminum tube (W) is being drawn, its drawing speed changes. That is, the control device (7) controls the drive of the winder (6) according to a preset program, and sets the winding speed of the winder (6) between the start of pulling and the end of pulling. Increase gradually. As a result, during the drawing process, the drawing speed gradually increases, and the final drawing speed becomes higher than the initial drawing speed.

  As described above, according to the drawing apparatus of the present embodiment, since the drawing speed is increased, the inner diameter dimension of the drawn tube can be maintained with high accuracy. That is, in the drawing process, for example, when the drawing speed is set constant from the start of drawing to the end of drawing, the aluminum pipe (drawing pipe) is processed so that the inner diameter dimension gradually increases from the front end side to the rear end side. End up. In general, the processing heat (processing heat generation) generated in the extraction plug (3) increases from the start to the end of extraction, and the diameter of the extraction plug (3) increases due to thermal expansion. It is estimated that the factor is that the inner diameter is also increased.

  On the other hand, in this embodiment, since the drawing speed is increased during drawing, the increase in the speed increases the amount of lubricating oil taken into the drawing plug (3), improving lubricity, The cooling effect by the lubricating oil is also improved, the processing heat generation is suppressed, and the thermal expansion of the extraction plug (3) is sufficiently suppressed. As described above, since the inner diameter dimension change due to the thermal expansion of the extraction plug (3) can be prevented, the inner diameter dimension of the extraction pipe can be maintained and managed with high accuracy.

  In this embodiment, the inner diameter dimension of the drawn product can be managed with high accuracy simply by adopting a simple configuration in which the drawing speed is increased during the drawing operation. A measuring device for measuring, a cleaning device for cleaning pipe materials, and a feedback device for feeding back measurement results are not required, and the production equipment can be made compact and compact accordingly. In addition, the cost can be reduced.

  For reference, in the drawn tube (drawn product) obtained by the drawing apparatus of the present embodiment, the inner diameter dimension difference between the front end and the rear end can be adjusted to 3 μm or less, and the inner diameter dimension is maintained at a high level. be able to.

  Here, in this embodiment, when the initial drawing speed at the start of drawing is “Vs” and the final drawing speed at the end of drawing is “Ve”, the final drawing speed (Ve) is set to the initial drawing speed (Vs). It is good to adjust to 1.5 to 3.0 times. That is, when the speed change magnification (Vs / Ve) is adjusted to the above range, the inner diameter dimension of the drawn product can be accurately managed. In other words, when the speed change magnification is too small, the inner diameter dimension of the drawn product cannot be accurately controlled, and the inner diameter dimension at the end of drawing of the pipe material may be increased. On the other hand, even if an attempt is made to set the speed change magnification too large, it is difficult in terms of equipment and may be difficult to implement.

  Furthermore, in the present embodiment, it is preferable to employ a configuration in which the drawing speed is increased at a constant rate from the start of drawing to the end of drawing, that is, a configuration in which the drawing speed is increased while keeping the acceleration constant. That is, in this configuration, the inner diameter dimension of the drawn product can be controlled more reliably, and the inner diameter dimension accuracy of the drawn product can be further improved.

  However, in the present invention, it is not always necessary to adopt a configuration in which the drawing speed is increased at a constant rate. For example, a configuration in which the extraction speed is increased stepwise, a configuration in which the extraction speed is increased while changing the acceleration, or the like can be employed. Furthermore, when the structure which increases a drawing speed in steps is employ | adopted, control of a drawing speed can be performed easily and this invention can be implemented easily.

  In this embodiment, the initial drawing speed (Vs) is preferably set to 15 to 25 m / min, more preferably 18 to 22 m / min. That is, when the initial drawing speed (Vs) is set within the above range, the speed change magnification can be easily adjusted within the specific range, and as described above, the inner diameter dimensional accuracy of the drawn product is improved. Can be made. Further, for the same reason, the final drawing speed (Ve) is preferably set to 35 to 60 m / min, more preferably 40 to 55 m / min.

<Example 1>
Using an apparatus similar to the drawing apparatus of the embodiment shown in FIGS. 1 and 2 above, drawing is performed using an aluminum alloy element tube of alloy symbol A3003 as a workpiece, and the outer diameter is 23.92 mm and the wall thickness is 0.71 mm. Made a drawn product.

  In this drawing process, as shown in Table 1, the initial drawing speed (Vs) is set to 20 m / min, the drawing speed is increased at a constant acceleration during drawing, and the final drawing speed (Ve) is 40 m. It adjusted so that it might become / min. In this drawing process, the magnification of the final drawing speed (Ve) with respect to the initial drawing speed (Vs) (speed change magnification Ve / Vs) is doubled.

  The drawn product thus obtained was cut at a predetermined interval, and the inner diameter dimension of each cut product was measured to obtain the amount of change in inner diameter dimension (μm) over the entire length of the drawn product.

  The measurement results are shown in the graph of FIG. In this graph, the horizontal axis indicates the position in the length direction of the drawn product, the right end position toward the graph is the leading end position of the drawn product (drawing start position), and the left end position is the trailing end position of the drawn product ( (Extraction end position). Further, the vertical axis represents the inner diameter dimensional change (μm) with reference to the rear end position of the drawn product.

<Example 2>
As shown in Table 1, the initial drawing speed (Vs) was adjusted to 20 m / min, the final drawing speed (Ve) was adjusted to 35 m / min, and the speed change magnification (Ve / Vs) was set to 1.75 times. Except that, drawing was performed in the same manner as above to obtain a drawn product.

  For the drawn product thus obtained, the inner diameter dimension was measured in the same manner as described above, and the relationship between the position in the length direction and the inner diameter dimension variation was determined. The result is shown in the graph of FIG.

<Example 3>
As shown in Table 1, the initial drawing speed (Vs) was adjusted to 20 m / min, the final drawing speed (Ve) was adjusted to 50 m / min, and the speed change magnification (Ve / Vs) was set to 2.5 times. Except that, drawing was performed in the same manner as above to obtain a drawn product.

  Measurements similar to the above were performed on the drawn products thus obtained. The results are shown in the graph of FIG.

<Example 4>
As shown in Table 1, the initial drawing speed (Vs) was adjusted to 20 m / min, the final drawing speed (Ve) was adjusted to 55 m / min, and the speed change magnification (Ve / Vs) was set to 2.75 times. Except that, drawing was performed in the same manner as above to obtain a drawn product.

  Measurements similar to the above were performed on the drawn products thus obtained. The result is shown in the graph of FIG.

<Comparative example>
As shown in Table 1, the drawing speed from the drawing start to the drawing end was adjusted to be constant at 30 m / min. Except that, drawing was performed in the same manner as described above to obtain a drawn product.

  Measurements similar to the above were performed on the drawn products thus obtained. The result is shown in the graph of FIG.

<Evaluation>
As shown in Table 1 and FIGS. 3 to 6, the drawn products of Examples 1 to 4 related to the present invention have a small change amount of the inner diameter with respect to the length direction, and can maintain the inner diameter with high accuracy. It was.

  On the other hand, as shown in Table 1 and FIG. 7, the drawn product of Comparative Example 1 that departs from the gist of the present invention has a large amount of change in the inner diameter with respect to the length direction. The amount of dimensional change is about 3 to 4 times larger, and it is difficult to maintain the inner diameter dimension with high accuracy.

  The drawing method of the present invention is suitably used when drawing a pipe material such as an aluminum pipe.

It is a side view which shows the drawing apparatus of the aluminum pipe which is embodiment of this invention. It is sectional drawing which expands and shows the drawing die periphery in the drawing processing apparatus of embodiment. It is a graph which shows the relationship between the length direction position and internal-diameter dimensional change amount in the drawing product of Example 1 relevant to this invention. It is a graph which shows the relationship between the length direction position and internal diameter dimensional change amount in the drawing product of Example 2. FIG. It is a graph which shows the relationship between the length direction position and internal-diameter dimensional change amount in the drawing product of Example 3. FIG. It is a graph which shows the relationship between the length direction position and internal-diameter dimensional change amount in the drawing product of Example 4. FIG. It is a graph which shows the relationship between the length direction position and internal-diameter dimensional change amount in the drawing product of the comparative example which deviates from the summary of this invention.

Explanation of symbols

2 ... Drawing die 3 ... Drawing plug 4 ... Chuck (pipe material gripping means)
6 ... Winding machine (pulling direction moving means)
7. Control device (drawing speed control means)
Ve ... Final drawing speed Vs ... Initial drawing speed W ... Aluminum tube

Claims (10)

A drawing method in which a tube material is drawn through a gap between a drawing die and a drawing plug,
The drawing is characterized in that the final drawing speed at the end of drawing is controlled to be higher than the initial drawing speed at the start of drawing by increasing the drawing speed during drawing from the start to the end of drawing. Processing method.   The drawing method according to claim 1, wherein the final drawing speed is set to 1.5 to 3.0 times the initial drawing speed.   The drawing method according to claim 1 or 2, wherein the drawing speed during drawing is continuously increased at a constant rate.   The drawing method according to claim 1 or 2, wherein the drawing speed during drawing is increased stepwise.   The drawing method according to any one of claims 1 to 4, wherein the initial drawing speed is set to 15 to 25 m / min.   The drawing method according to any one of claims 1 to 5, wherein the final drawing speed is set to 35 to 60 m / min.   The drawing method according to any one of claims 1 to 6, wherein an aluminum pipe made of aluminum or an alloy thereof is used as the pipe material.   A drawn product produced by the drawing method according to any one of claims 1 to 7.   The drawn product according to claim 8, wherein a difference in inner diameter between the front end and the rear end is adjusted to 3 μm or less. Drawing dies,
A drawing plug arranged corresponding to the die hole of the drawing die;
Tube material gripping means for gripping the tip of the tube material passed through the gap between the drawing die and the drawing plug;
A drawing direction moving means for moving the tube gripping means in the drawing direction;
Pulling is started by controlling the driving of the drawing direction moving means, moving the tube gripping means in the drawing direction to perform drawing processing, and increasing the drawing speed during drawing from the start of drawing to the end of drawing. A drawing speed control means for making the final drawing speed at the end of drawing higher than the initial drawing speed at the time.

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