JP3754682B2 - Die for drawing - Google Patents

Description

  The present invention relates to a drawing die used for drawing wire, rod, strip, pipe and the like.

  FIG. 3 shows a conventional die structure used for drawing a wire or a rod. The conventional die 40 has a structure in which a die chip 40A made of a cemented carbide and a die case 40B surrounding the die chip 40A are integrated. A die hole 40C is provided at the center of the die chip 40A. The die hole 40 </ b> C includes a mouse part 41 positioned closest to the entry side, an approach part 42 following the mouse part 41, a bearing part 43 following the approach part 42, and a back leaf part 44 following the bearing part 43.

  The mouse part 41 is a taper-shaped material guide hole that is reduced in diameter from the entry side to the exit side at a relatively large angle, and its minimum diameter, that is, the exit diameter, is larger than the material diameter before processing. The approach portion 42 following the mouse portion 41 is a tapered hole that gradually decreases in diameter from the entry side to the exit side at a relatively small angle, and its minimum diameter, that is, the exit diameter, is smaller than the material diameter before processing. It is larger than the later material diameter. As the material passes through this approach portion 42, it gradually approaches the required cross-sectional shape.

  The bearing portion 43 following the approach portion 42 is a portion that determines the cross-sectional shape. The bearing portion 42 is gradually reduced in diameter toward the outlet side in the first half portion, and matches the required cross-sectional shape in the second half portion. The back leaf part 44 following the bearing part 43 is a so-called escape part, and is expanded in a trumpet shape at a relatively large angle toward the exit side.

  Such a die 40 is set in a die holder (not shown), and further set in a drawing machine for drawing.

  By the way, as one of the big problems in the drawing process of a wire or a bar, there is a twist generated in a material after processing, that is, a material passing through a die. This twist is mainly caused by subtle deformation of the die hole, but is also considered to be affected by non-uniform qualities of materials and poor machine accuracy.

  Twist deformation caused by complicated entanglement of dies, materials, and machines is unavoidable, and it is difficult to take countermeasures at the processing site, and it is also difficult to correct the twist generated in the material after drawing. The fact is that it cannot be left unattended. For this reason, until now, the only effective countermeasure against twisting is to shape the die hole according to the degree of twisting so that the twisting does not occur every time the twisting occurs.

  However, the measure to process the die whenever twisting occurs is, of course, very inefficient and costly. In addition, since not only the die but also the material and the machine affect the twist, there is a risk that even if the die is machined, for example, if the material of the workpiece changes, the twist may recur. For this reason, the twist in drawing is a very troublesome problem.

  In addition, the present applicant first developed a combination die obtained by dividing functions required for the die (see Patent Document 1). In this die, the approach portion of the die hole and the bearing portion are divided into two independent dies, the approach die having the approach portion provided in the die hole, and the bearing portion provided in the die hole. The present inventors thought that the combination with a bare rig die has an effect such as eliminating the need for back tension, but the twisted deformation is not as effective as a general die.

Utility Model Registration No. 3050071

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a drawing die that can quickly and easily prevent torsional deformation accompanying drawing.

  In order to achieve the above object, the present inventor paid attention to the above-described function division type combination die. That is, a typical mechanism for twisting in the die is that the bearing on the exit side adds a twist in the circumferential direction to the material constrained by the approach portion on the entry side. For example, when the material is twisted clockwise as viewed from the entry side, the bearing portion adds clockwise twist to the material constrained by the approach portion.

  Here, if the approach portion and the bearing portion are provided on independent dies as in the above-described function division type combination die, the approach portion and the bearing portion can be relatively rotated in the circumferential direction. Easy. Then, if the approach portion is rotated clockwise with respect to the bearing portion in the direction of twisting, the twisting factor in the die can be removed. Further, it is possible to intentionally generate a new twist that cancels the twist generated on the material side or the machine side.

  In other words, if the above-mentioned function-division type combination die is developed to enable the relative rotation operation of the approach die and the bearing die, it becomes possible to prevent twisting at the processing site, which has been impossible until now. It becomes.

  The drawing die according to the present invention has been completed on the basis of such an idea, and an approach die in which an approach portion for bringing a material cross-section closer to a required shape is provided in a die hole, and a shape required for a material cross-section. A bearing die in which a bearing portion is provided in the die hole, a die holder for holding both dies side by side in the axial direction, and supporting both dies so that they can be rotated relative to each other in the circumferential direction, and one die for the other And a die operating mechanism that rotates relative to the other die.

  For relative rotation of both dies, both the approach die and the bearing die can be rotated. However, from the viewpoint of simplifying the configuration, one die can be rotatably supported in the die holder. It is preferable that the die is a fixed die that is fixed in the die holder, and in particular, the approach die located on the front side of the die holder that can be easily rotated is a movable die, and the back of the die holder is used. It is preferable that the bearing die arranged in the is a fixed die. According to this configuration, the die operation mechanism is particularly simplified.

  When the material that has passed through the drawing die according to the present invention is twisted clockwise as viewed from the entry side, the approach die is rotated relative to the bearing die in the clockwise direction. Thereby, the twist can be prevented. When the die passing material is twisted counterclockwise, the twist of the approach die can be prevented by rotating the approach die relative to the bearing die counterclockwise.

  The drawing die according to the present invention can prevent the twist generated in the processed material immediately and accurately at the drawing work site by the relative rotation operation of the approach die and the bearing die. This eliminates the need for time-consuming dicing for twisting, and has a great effect on reducing the drawing cost and improving the machining efficiency.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a drawing die showing an embodiment of the present invention, and FIG. 2 is a longitudinal side view of the drawing die.

  The drawing die according to the present embodiment includes an approach die 20 and a bearing die 30 accommodated in a cylindrical die holder 10 so as to be arranged concentrically in the axial direction. This drawing die is used for drawing a bar, and functionally corresponds to the integrated conventional die 40 shown in FIG. That is, the die is assumed to be finished to the same dimensions using the same material as in the case of the integrated conventional die 40 shown in FIG.

  The approach die 20 located on the entry side has a structure in which a die chip 20A made of cemented carbide and a die case 20B surrounding the die chip 20A are integrated. A die hole 20C having a circular cross section provided at the center of the die chip 20A includes a mouse portion 21 positioned closest to the entry side, an approach portion 22 following the mouse portion 21, a bearing portion 23 following the approach portion 22, and a bearing. It consists of a back leaf part 24 following the part 23.

  The mouse part 21 is a mouse part corresponding to the mouse part 41 of the conventional die, and is gradually reduced in diameter from the entrance side to the exit side at a relatively large angle, like the mouse part 41. And the minimum diameter of the mouse | mouth part 21, ie, an exit diameter (same as the entrance diameter of the approach part 22), is larger than the raw material diameter before a process.

  The approach part 22 following the mouse part 21 is an approach part corresponding to the approach part 41 of the conventional die 40 and is gradually reduced in diameter from the entrance side to the exit side at a relatively small angle, like the approach part 41. . The minimum diameter of the approach portion 22, that is, the outlet diameter (same as the inlet diameter of the bearing portion 23) is smaller than the raw material diameter before processing and larger than the target diameter required after processing. That is, the material gradually approaches the required cross-sectional shape by passing through the approach portion 22.

  The bearing portion 23 following the approach portion 22 is a dummy hole that does not originally have a function as a bearing portion, and is a straight hole that is equal to the exit diameter of the approach portion 22 over the entire length. The back leaf part 24 following the bearing part 23 is also a dummy hole, and is enlarged in a trumpet shape at a relatively large angle from the outlet of the bearing part 23 toward the outlet side.

  The bearing die 30 located on the outlet side has a structure in which a die chip 30A made of a cemented carbide and a die case 30B surrounding the die chip 30A are integrated. A die hole 30C having a circular cross section provided at the center of the die chip 30A includes a mouse part 31 positioned closest to the entry side, an approach part 32 following the mouse part 31, a bearing part 33 following the approach part 32, and a bearing. It consists of a back leaf part 34 following the part 33.

  The mouse portion 31 is a tapered material guide hole that gradually decreases in diameter from the entry side toward the exit side. The mouth portion 31 is a dummy hole for introducing the material that has passed through the bearing die 20, and the minimum diameter thereof, that is, the outlet diameter (same as the inlet diameter of the approach portion 32), of the bearing portion 23 in the bearing die 20. The diameter is set slightly larger than the outer diameter of the introduction material.

  The approach part 32 following the mouse part 31 is a tapered hole that gradually decreases in diameter from the entry side toward the exit side, and is a dummy hole. The minimum diameter of the approach part 32, that is, the outlet diameter (same as the inlet diameter of the bearing part 33) is set to be smaller than the minimum diameter of the approach part 32 in the bearing die 20 and slightly larger than the target diameter required after processing. . The taper inclination angle of the approach portion 32 is smaller than that of the mouse portion 31.

  The bearing portion 33 following the approach portion 32 is a bearing portion corresponding to the bearing portion 43 of the conventional die 40. Like the bearing portion 43, in the first half portion, the diameter is gradually reduced to the target diameter required after processing. Then, it matches the target diameter. The back leaf portion 3 following the bearing portion 33 is a relief portion corresponding to the back leaf portion 44 of the conventional die 40, and is expanded in a trumpet shape at a relatively large angle toward the exit side with the back leaf portion 44. It has a diameter.

  A particularly important configuration of the drawing die according to the present embodiment is that an output-side bearing die 30 inserted in the back of the die holder 10 is fixed in the circumferential direction by pins 11, 11 in the die holder 10. 10 is that the approach die 20 on the entry side arranged on the front side of 10 is rotatable in the circumferential direction. Then, the approach die 20 is rotated by the pinion gear 12 attached to the entry side end surface of the die holder 10. That is, the pinion gear 12 meshes with a rack gear 20D formed in an arc shape on the outer peripheral surface of the end of the approach die 20 so that the approach die 20 rotates in the circumferential direction by the rotation operation, and the die is combined with the rack gear 20D. The operation mechanism is configured.

  Next, the usage method and function of the drawing die according to the present embodiment will be described.

  The drawing die is set in a drawing machine, and a rod-shaped material having a circular cross section is passed through the die. The material passes through the approach die 20 and the bearing die 30 in the die holder 10 in this order, so that a small diameter drawn product is obtained. That is, after being processed halfway in the process of passing through the approach part 22 of the approach die 20, the final cross-sectional shape is processed in the process of passing through the bearing part 33 of the bearing die 30.

  At this time, various factors on the die side, the material side, and the machine side often synergize to cause a twist in the circumferential direction in the processed material. When the material is twisted in the clockwise direction when viewed from the front side of the holder, that is, from the entrance side, it is conceivable that the material constrained by the approach portion 22 of the approach die 20 is twisted in the clockwise direction by the bearing portion 33 of the bearing die 30. Furthermore, it is conceivable that twists due to other factors are combined.

  In this case, the pinion gear 12 is operated so as to rotate the approach die 20 in the same clockwise direction as the twist direction. When the approach die 20 on the entry side is rotated in the same clockwise direction as the twist direction, the cause of twist in the die is removed. Also, a reverse twist that counteracts the twist due to other factors can be added to the material. If the twist is counterclockwise, it may be operated counterclockwise.

  In short, when twist occurs in the processed material, the approach die 20 may be slightly rotated in the same direction as the twist direction in accordance with the degree of twist so that the twist disappears. As a result, an efficient and economical twist prevention operation at a processing site that has been impossible until now becomes possible.

  In the above embodiment, the drawing die is a circular die having a circular die hole, but it goes without saying that it may be a deformed die having a die hole other than a circular cross section.

1 is a front view of a drawing die showing an embodiment of the present invention. It is a vertical side view of the same drawing die. It is a vertical side view of the conventional drawing die.

Explanation of symbols

10 Die Holder 11 Pin 12 Pinion Gear 20 Approach Die 20A Die Chip 20B Die Case 20C Die Hole 20D Rack Gear 21 Mouse Part 22 Approach Part 23 Bearing Part 24 Back Leaf Part 30 Bearing Die 30A Die Chip 30B Die Case 31 Mouse Part 32 Approach Part 33 Bearing part 34 Back leaf part

Claims (4)

  An approach die in which the approach part that brings the material cross section closer to the required shape is provided in the die hole, a bearing die in which the bearing part that matches the material cross section to the required shape is provided in the die hole, and both dies are axially centered A die holder that holds the dies side by side and supports both dies so that relative rotation in the circumferential direction is possible, and a die operation mechanism that rotates one die relatively in the circumferential direction relative to the other die. A drawing die characterized by comprising.   The drawing die according to claim 1, wherein one of the dies is a movable die rotatably supported in a die holder, and the other is a fixed die fixed in the die holder.   The drawing die according to claim 2, wherein the approach die is a movable die, and the bearing die is a fixed die.   4. The die operation mechanism is a combination of a pinion gear attached to an entry side end surface of the die holder and an arcuate rack gear formed along the outer peripheral surface of the approach die so that the pinion gear meshes. Die for drawing as described in 2.

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