JP2005193280A - Drawing method of tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drawing method of a tube which can improve a work efficiency from a step to insert a mandrel into a mother tube to a step to separate the mandrel from the mother tube. <P>SOLUTION: The drawing method of a tube comprises a step to insert the mandrel 200 into the mother tube 100, a step to draw the mother tube 100 with the mandrel inserted through a die 10, and a step to separate the drawn mother tube 100 and the mandrel 200. In the inserting step of the mandrel 200, a squeezed portion 110 of the mother tube 100 squeezed at its end is inserted into the die 10 to hold the position of the mother tube 100. In that state the top of the mandrel 200 is pulled by a drawing carriage 20 and the mandrel 200 is inserted into the mother tube 100. In the separation step of the mandrel 200 and the mother tube 100, a stopper 220 is prepared at the tail end of the mandrel 200, and the drawing carriage 20 is moved in the drawing direction of the mother tube 100. Thereby, the stopper 220 comes to touch with the die 10 and retains the position of the mandrel 200. The drawing carriage 20 is further moved in the drawing direction to draw the mother tube 100 over the mandrel 200. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tube drawing method. In particular, the present invention relates to a method for pulling out a pipe having excellent work efficiency.

  Conventionally, in order to obtain a desired pipe, it is known to insert a mandrel into the base pipe and pull out the base pipe with a die or forge it with a press. In any case, a step of inserting a mandrel into the element tube, a step of processing the element tube into which the mandrel is inserted, and a step of separating the processed element tube and the mandrel are performed.

  For example, Patent Document 1 discloses a technique of pulling a mandrel and a cylindrical body tube through a die and integrally pulling them out. With this technology, after drawing, a rotating roller is pressed against the outer circumference of the cylindrical body tube to form a clearance between the mandrel and the cylindrical body tube, so that the mandrel can be easily removed from the cylindrical body tube I have to.

  Patent Document 2 discloses a technique for forging a pipe material into which a mandrel is inserted with a press. In this technique, a sleeve with a flange is fitted to the end of the pipe material before forging. After this pipe material is forged with a press anvil, the flange portion of the sleeve is brought into contact with and supported by the anvil. In this state, the mandrel can be easily pulled out from the pipe material by applying a pulling force to the mandrel.

JP 56-74327 A Japanese Patent Laid-Open No. 5-775553

  However, any of the above techniques has a problem mainly in terms of work efficiency. More specifically, it is as follows.

  The technique described in Patent Document 1 requires a roller that is brought into pressure contact with the outer periphery of the cylindrical body tube after drawing. There is a draw bench as an equipment used for drawing a pipe, but a general draw bench does not have such a roller. Therefore, in order to realize the technique described in Patent Document 1, it is necessary to add a roller, which is accompanied by equipment burden. In addition, this technique does not disclose a specific method for extracting a mandrel from a cylindrical tube after being rolled by a roller. When the mandrel is short, it is conceivable to manually extract the mandrel, but when the mandrel is lengthened (weighted), this operation is not easy. In particular, it is extremely difficult for a single worker to perform this sampling operation.

  The technique described in Patent Document 2 is a forging pipe processing technique. However, when this technique is assumed to be applied to drawing, it involves a considerable work burden or equipment burden.

  Usually, a draw bench shown in FIG. 4A is used for drawing a tube using a die. The draw bench includes a die 10 and a pulling cart 20 that is movable in the axial direction of the die 10. The drawing process is performed by inserting a mandrel 200 into the base tube 100, holding the base tube 100 with the pulling carriage 20, and passing it through the die 10. The processed cored mandrel is positioned on the outlet side of the die 10, that is, on the left side of FIG.

  However, in order to extract the mandrel 200 using the pulling cart 20, as shown in FIG. 4 (B), the mandrel-containing element tube is moved to the inlet side of the die 10, and the element tube 100 is removed. It is necessary to reverse the direction. In this state, the flanged sleeve 40 is attached to the distal end side of the base tube 100, and the rod member 230 is attached to the end of the mandrel 200. Then, the bar 230 is gripped by the pulling cart 20, and the mandrel 200 is pulled out by moving the cart 20 away from the die 10 (FIG. 4C). However, in such a method, it is necessary to move the core tube containing the mandrel and change the orientation, and the work load is extremely large. In particular, when the mandrel 200 is long, the work load further increases.

  On the other hand, in order to extract the mandrel 200 without changing the cored core tube or changing the orientation, as shown in FIGS. 50 must be used. In other words, the pulling cart 20 is placed on one side of the die 10 and the mandrel pulling cart 50 is arranged on the other side, and the bar 230 attached to the mandrel 200 after the drawing is gripped by the core pulling cart 50 and pulled out. become. However, in this method, it is necessary to provide the mandrel withdrawal cart 50 separately from the withdrawal cart 20, and the equipment burden is large.

  Furthermore, none of the patent documents disclose a specific method for efficiently performing the process of inserting the mandrel into the element tube. The outer diameter of the mandrel is set to be slightly smaller than the inner diameter of the base tube, but usually the difference between the two is slight. Therefore, it is not easy to insert the mandrel into the base tube under the condition that there is only a slight clearance. In addition, since the mandrel is a solid material, the mandrel is heavy, and particularly when the mandrel becomes long, the difficulty of inserting the mandrel into the base tube becomes even more remarkable.

  Accordingly, a main object of the present invention is to provide a tube drawing method that can improve the work efficiency from the step of inserting a mandrel into the tube to the step of separating the mandrel and mandrel.

  The present invention uses the pulling cart for pulling out the raw tube, and performs at least one of the step of inserting the mandrel into the raw tube and the step of separating the drawn raw tube from the mandrel. To achieve the objectives.

  The method of pulling out a tube according to the present invention includes a step of inserting a mandrel into the core tube, a step of pulling out the core tube into which the mandrel has been inserted with a die, and a step of separating the drawn core tube and the mandrel. It is the drawing method of the pipe | tube which has.

  Here, the drawing process of the raw tube is performed by holding and pulling the distal end portion of the raw tube with a drawing carriage, and passing the raw tube with the mandrel inserted through a die. The present invention is characterized in that the pulling carriage is used as follows in at least one of the mandrel insertion step and the blank tube and mandrel separation step.

  In other words, when using a drawing carriage for the mandrel insertion process, this insertion process includes the step of inserting the mouthpiece processing portion of the blanked tube into the die and holding the position of the tube, and the tip side of the mandrel. Pulling with a pulling carriage and inserting the mandrel into the base tube.

  Since the outer diameter of the raw pipe before drawing is larger than the inner diameter of the die, the tip of the raw pipe is formed into a taper shape smaller than the inner diameter of the die by staking. For this reason, when the crimping portion is inserted into the die, the raw tube is held at a position where the end portion of the crimping portion is located on the outlet side of the die. If the tip end side of the mandrel is pulled using the pulling carriage in this state, the mandrel can be inserted into the positioned raw tube.

  In addition, when a pulling cart is used for the separation process of the core tube and the mandrel, this separation process is performed by providing a stopper on the end side of the mandrel and moving the pulling cart in the pulling direction of the blank tube. And holding the position of the mandrel by contacting the die, and further, the step of moving the pulling carriage in the pulling direction and pulling the blank from the mandrel.

  When the end of the core tube in which the mandrel is inserted is pulled out by the trolley and passed through the die, a stopper is provided on the end side of the mandrel, so this stopper abuts the die and the position of the mandrel Is retained. In this state, if the pulling carriage is further moved away from the die, the mandrel can be easily extracted from the base tube.

  Of course, if the pulling cart is used for both the mandrel insertion process and the tube and mandrel separation process, a series of pulling operations can be performed more efficiently.

  Hereinafter, the configuration of the present invention will be described in more detail.

  In order to carry out the drawing method of the present invention, the raw tube is pierced as a pre-process. The splicing process is a process for forming the tip of the raw tube into a tapered shape with a swaging machine or the like so that the end of the raw tube can be easily inserted into a die.

  A mandrel is inserted into the mouthpiece. At that time, an extraction carriage for extracting the raw tube through a die is used. The pulling cart is not particularly limited as long as it has a drive mechanism for reciprocating the cart in the axial direction of the die and a gripping mechanism such as a raw tube. For example, hydraulic or air cylinders can be used for driving the pulling cart. The gripping mechanism only needs to be able to grip the raw tube or a connecting member described later, and a chuck or the like can be used.

  For the mandrel inserted into the base tube, a metal rod having an outer diameter slightly smaller than the inner diameter of the base tube is used. The mandrel is preferably provided with an engaging portion on the tip side and a stopper on the end side in advance. When the mandrel is inserted into the base tube, a pulling cart is arranged on the tip side of the base tube, and the mandrel is arranged on the end side of the base tube. At that time, since the pulling cart and the tip of the mandrel are separated from each other, the mandrel is pulled by connecting the two with a connecting member and pulling the connecting member with the pulling cart. If an engaging part is provided at the tip of the mandrel, one end of the connecting member can be hung on the engaging part, and the mandrel and the connecting member can be easily connected.

  The connecting member only needs to be able to withstand the tension when the mandrel is inserted into the base tube using the pulling cart, and various configurations and materials can be used. For example, a string-like body or a rod-like body using metal, plastic, carbon fiber, or glass fiber is suitable. Since the connecting member is inserted into the raw tube and used, it is preferable to prevent the inner surface of the raw tube from being damaged by providing a resin coating on the surface thereof. For example, in the case of a string-like body, a wire in which a resin strand such as polyethylene, polyvinyl chloride, or polyamide is formed on a metal stranded wire is preferable. In the case of a rod-shaped body, a metal core coated with polyamide is suitable. Of course, as long as the strength permits, a string-like body / bar-shaped body made of only a resin material such as polyamide or aramid may be used.

  The stopper is a member for holding the position of the mandrel with respect to the die in the separation process of the base tube and mandrel. The configuration is not particularly limited as long as the member has an outer dimension larger than the inner diameter of the die and can be fixed to the end side of the mandrel. The stopper may be fixed to the mandrel from the beginning, and the process from the step of inserting the mandrel into the element tube using the mandrel to the step of separating the element tube and the mandrel may be performed. In that case, a series of processes such as insertion of the mandrel, extraction of the core tube, and separation of the core tube and the mandrel can be efficiently performed by a simple operation of simply reciprocating the extraction carriage. In addition, the process which attaches a stopper to the terminal end side of a mandrel after the drawing process using a die and separates the base tube and the mandrel may be performed.

  The pipe drawing method of the present invention can be used for drawing various metal pipes. In particular, it is suitable to use for drawing a magnesium alloy.

  According to the method of the present invention, by using at least one of the insertion process of the mandrel into the element tube and the separation process of the element tube and the mandrel using the pulling cart, the mandrel is inserted into the element tube. The workability from the raw tube to the mandrel separation process can be improved.

  Moreover, the process from the insertion of the mandrel into the element tube to the separation process of the element tube and the mandrel can be performed using a conventional draw bench, and no special equipment burden is involved.

  Embodiments of the present invention will be described below.

  In the method of the present invention, as a preliminary step, the blank tube is subjected to a mouth-opening process. Thereafter, using the raw tube, a step of sequentially inserting a mandrel into the raw tube, a step of pulling out the raw tube into which the mandrel has been inserted with a die, and a step of separating the mandrel from the drawn raw tube. Hereinafter, each process will be described in detail with reference to the drawings. FIG. 1 is an explanatory view of a process of inserting a mandrel into a raw tube in the method of the present invention, FIG. 2 is an explanatory diagram of a process of pulling out the raw tube with a die in the method of the present invention, and FIG. It is explanatory drawing of the process of isolate | separating.

<Making of tube and preparation of mandrel>
First, a raw tube 100 having a uniform inner and outer diameter in the longitudinal direction is prepared, and one end thereof is subjected to a squeezing process. The outer diameter of the raw tube 100 is configured to be larger than the inner diameter of a die 10 described later. The splicing process is a process for making the tip of the base tube 100 taper smaller than the inner diameter of the die 10 so that the base tube 100 can be easily inserted into the die 10. This processing can be performed with a swaging machine or the like.

  On the other hand, the mandrel 200 is a metal bar having an outer diameter slightly smaller than the inner diameter of the base tube 100. A hook-shaped hook 210 is fixed to one end of the mandrel 200, and a stopper 220 is fixed to the other end. The stopper 220 is a disc having an outer diameter larger than the inner diameter of the die.

<Process for inserting mandrel into the base tube>
After finishing the pipe 100, the pipe 100 is set on a draw bench (FIG. 1A). The draw bench includes a die 10 and a drawing carriage 20 that can reciprocate in the axial direction of the die 10. The die 10 is an annular member having a circular hole. The drawing carriage 20 is disposed on the left side of the die 10 in the draw bench, has a base tube 100 and a chuck 21 that holds a wire to be described later, and is driven by a hydraulic cylinder (not shown). On the right side of the die 10 in this draw bench, the base tube 100 and the mandrel 200 that have been subjected to lip processing are arranged in series. At that time, the base tube fitting part 110 is inserted into the circular hole of the die 10 and the mandrel hook 210 is directed to the die 10 side.

  Next, the pulling carriage 20 and the tip of the mandrel 200 are connected by a wire 30 having a resin coating. A loop is formed at one end of the wire 30, this loop is hung on the hook 210 of the mandrel, the wire 30 is passed through the base tube 100, and the other end of the wire 30 is pulled out and held by the chuck 21 of the carriage 20. To do.

  Subsequently, the pulling cart 20 is moved away from the die 10 (FIG. 1B). By this movement, the end of the mandrel 200 presses the distal end side of the element tube 100, and the mouthpiece processing part 110 of the element tube 100 is inserted into the circular hole of the die 10. The outer diameter of the crimping section 110 is smaller than the inner diameter of the die 10, but the outer diameter of the raw pipe 100 other than the crimping section is larger than the inner diameter of the die 10. It is held at the inserted position. In this state, when the pulling cart 20 is further moved away from the die 10, the tip of the mandrel 200 is inserted into the base tube 100 from the end. The mandrel 200 is inserted over almost the entire length of the base tube 100 other than the mouthpiece processing portion.

  If the mandrel 200 can be inserted into the base tube 100, the gripping of the wire 30 by the chuck 21 is released, the loop of the wire 30 is removed from the hook 210, and the wire 30 is removed.

<Process to pull out the core tube with the mandrel inserted with a die>
Next, the pulling carriage 20 is returned to the vicinity of the die, the chuck 21 is opened, and the opening portion 110 of the blank tube exposed on the outlet side of the die 10 is gripped (FIG. 2 (A)). In this state, the pulling cart 20 is moved again away from the die 10.

  By the movement of the pulling carriage 20, the base tube 100 is passed through the die 10 together with the mandrel 200. At that time, the raw tube 100 is compressed and thinly stretched between the die 10 and the mandrel 200, and is processed into a tube having an inner diameter corresponding to the outer diameter of the mandrel 200 and having a predetermined thickness. This drawing is performed until the raw tube 100 is completely pulled out through the die 10 (FIG. 2B).

<Process for separating the drawn tube and mandrel>
When the drawing of the raw tube 100 by the die 10 is completed, the drawing carriage 20 is continuously moved away from the die 10. As the carriage 20 moves, the stopper 220 at the end of the mandrel comes into contact with the die 10 (see FIG. 2B). At that time, since the stopper 220 is caught by the die 10, the position of the mandrel 200 is held. In this state, when the pulling carriage 20 is further moved away from the die 10, only the element tube 100 is extracted from the mandrel 200, and the element tube 100 and the mandrel 200 can be easily separated (see FIG. 3).

  In this way, by using the pulling cart for the insertion process of the mandrel into the core tube and the separation process of the core tube and the mandrel, the core tube is inserted through the core tube and then pulled out. It is possible to efficiently perform a series of operations up to the separation of the core and the mandrel.

  In particular, a series of operations using this pulling cart can use a conventional general draw bench as it is, and does not require any special additional equipment.

  In the above embodiment, the pulling trolley is used for both the insertion process of the mandrel into the blank tube and the separation process of the blank tube and the mandrel, but the pulling cart is used for either one of the processes. The working efficiency from the insertion of the mandrel into the element tube to the separation of the element tube and the mandrel can be improved. In particular, even when the mandrel is long, it is possible to perform a series of tube processing operations by a single operator.

  The method of the present invention can be used for drawing a metal tube, for example, drawing a magnesium alloy tube.

It is explanatory drawing of the process of inserting a mandrel in a base tube in the method of this invention. It is explanatory drawing of the process of drawing out a raw tube with a die | dye in the method of this invention. It is explanatory drawing of the process of isolate | separating a raw tube and a mandrel in the method of this invention. It is explanatory drawing which shows the process of extracting a mandrel from an element pipe using a sleeve with a flange. It is explanatory drawing which shows the process of extracting a mandrel from a raw tube using a mandrel extraction cart.

Explanation of symbols

10 Dies 20 Pulling cart 21 Chuck
30 wire 40 sleeve with flange 50
100 Base tube 110
200 Mandrel 210 Hook 220 Stopper 230 Bar

Claims (5)

A method of pulling out a tube, the method comprising: inserting a mandrel into the element tube; extracting the element tube into which the mandrel has been inserted with a die; and separating the extracted element tube and the mandrel;
The insertion process of the mandrel is
A step of holding the position of the raw pipe by inserting the lip-processed portion of the raw pipe into the die,
Pulling the distal end side of the mandrel using a pulling cart and inserting the mandrel into the base tube,
The drawing process of the raw tube
Holding and pulling the tip of the tube with the pulling carriage, and passing the tube with the mandrel inserted through a die,
The separation process of the raw tube and mandrel is as follows:
A stopper is provided on the distal end side of the mandrel, and the stopper is brought into contact with the die by moving the pulling carriage in the pulling direction of the base tube, and holding the position of the mandrel;
And a step of drawing the base tube from the mandrel by moving the drawing carriage in the drawing direction. A method of pulling out a tube, the method comprising: inserting a mandrel into the element tube; extracting the element tube into which the mandrel has been inserted with a die; and separating the extracted element tube and the mandrel;
The insertion process of the mandrel is
A step of holding the position of the raw pipe by inserting the lip-processed portion of the raw pipe into the die,
Pulling the distal end side of the mandrel using a pulling cart and inserting the mandrel into the base tube,
The drawing process of the raw tube
A method of pulling a tube, comprising: holding and pulling a tip of the raw tube with the pulling carriage, and passing the raw tube into which a mandrel is inserted through a die. A method of pulling out a tube, the method comprising: inserting a mandrel into the element tube; extracting the element tube into which the mandrel has been inserted with a die; and separating the extracted element tube and the mandrel;
The drawing process of the raw tube
Holding and pulling the tip of the raw tube with a pulling carriage, and passing the raw tube with the mandrel inserted through a die,
The separation process of the raw tube and mandrel is as follows:
A stopper is provided on the distal end side of the mandrel, and the stopper is brought into contact with the die by moving the pulling carriage in the pulling direction of the base tube, and holding the position of the mandrel;
And a step of drawing the base tube from the mandrel by moving the drawing carriage in the drawing direction. The step of inserting the mandrel into the bare tube
An engagement part is provided on the tip side of the mandrel,
The pipe pulling method according to any one of claims 1 to 3, wherein the pipe is pulled by engaging the connecting member with the engaging portion and pulling the connecting member with a pulling cart.   4. The method of pulling out a tube according to claim 3, wherein a mandrel having a stopper on the end side is used to perform a mandrel insertion step and a blank tube pulling step.

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