JP2020075339A - Wire cutting device - Google Patents

Abstract

To provide a wire cutting device capable of improving both of dimensional accuracy of a workpiece manufactured by cutting and plane accuracy of a cut surface.SOLUTION: A wire cutting device 1 includes a wire delivering part 5 which intermittently delivers wire M by a prescribed length L, a fixing blade part 6 which supports other than a cutting range from a tip of delivered wire M to a prescribed length L, a movable blade part 7 constituted with a plurality of division movable blades 71, 72 which grips and releases outer circumferential surfaces of the cutting range of the wire M, a grip driving part 79 which drives the movable blade part 7 such that the division movable blades 71, 72 release the outer circumferential surface when the wire M is delivered and the division movable blades 71, 72 grip the outer circumferential surface when the wire M is cut, and a cutting drive part 8 which drives the movable blade part 7 in such a direction as to intersect the wire M, shears the wire M between the fixing blade part 6 and the cutting drive part and manufactures the workpiece W.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wire rod cutting device that cuts a wire rod to produce a work, and more particularly to a technique for improving the finish accuracy of the work.

  A forging machine that has a die and a punch and performs forging processing often includes a wire rod cutting device that cuts a metal wire rod to produce a work. The wire rod cutting device includes a wire rod feeding unit that intermittently feeds the wire rod by a predetermined length, and a cutter unit that cuts the wire rod. A roller feeding mechanism and a reciprocating feeding mechanism are known as the mechanism of the wire rod feeding portion. As a mechanism of the cutter unit, there is known a mechanism that has a ring-shaped fixed blade and a movable blade, inserts the wire rod with the centers of both blades aligned, and then reciprocates the movable blade to shear the wire rod. An example of this kind of wire rod cutting device is disclosed in Patent Document 1.

  The forging machine of Patent Document 1 selectively uses a main drive unit and a sub drive unit as a drive source for moving a cutter rod that drives a movable blade. According to this, the cutter rod can be driven at a high speed from the auxiliary drive unit when the main drive unit is driven at a low speed in the trial shot adjustment. Therefore, it is said that the perpendicularity of the cutting surface of the cutting blank (workpiece) can be obtained, and sagging, burrs, and roughness of the cutting surface do not occur. A method of increasing the accuracy of shearing by moving the movable blade at high speed is called a hammer cutter method.

Utility Model Registration No. 3130796

  By the way, according to Patent Document 1, the movable blade can be operated at high speed not only when the main drive moves the movable blade at high speed during normal operation, but also when the auxiliary drive is used during adjustment. However, when the production speed (pieces / minute) of the work is changed during normal operation, the operation speed of the movable blade changes, which affects the finish accuracy of the work. Further, it is difficult to maintain good dimensional accuracy of the work and surface accuracy of the cut surface even if the hammer cutter method is used.

  For example, in a configuration in which a roller feeding mechanism is used for the wire rod feeding unit, the tip of the wire rod is pressed against the stopper member and shearing is performed while an external force in the axial direction is acting. At this time, since the tip end surface of the wire rod rubs against the stopper member, the surface accuracy of the cut surface of the manufactured work decreases. Further, in the configuration using the reciprocating feed mechanism having a structure for gripping the wire rod in the wire rod feeding portion, the stopper member is not used, and the problem of friction does not occur. However, since no external force is applied to the wire rod in the axial direction, the wire rod and the workpiece may move or tilt during the shearing operation. As a result, the perpendicularity of the cut surface of the work is reduced, and the dimensional accuracy cannot be obtained. The problem that the perpendicularity of the cut surface decreases is more remarkable as the length is shorter than the diameter of the work.

  The present invention has been made in view of the problems of the background art described above, and provides a wire rod cutting device that can improve both the dimensional accuracy of a workpiece manufactured by cutting and the surface accuracy of a cut surface. This is an issue.

  The wire rod cutting device of the present invention, a wire rod feeding unit that intermittently feeds the wire rod by a predetermined length, a fixed blade portion that supports a portion other than the cutting range from the tip of the fed wire rod to the predetermined length, and the wire rod. When a movable blade portion configured by a plurality of divided movable blades that grips and releases the outer peripheral surface of the cutting range, and the divided movable blade releases the outer peripheral surface when the wire rod is fed and cuts the wire rod In between the fixed blade portion, by driving the movable blade portion in a direction intersecting with the wire rod, and a grip drive portion that drives the movable blade portion so that the divided movable blade grasps the outer peripheral surface. A cutting drive unit that shears the wire to produce a work.

  In the wire rod cutting device of the present invention, when the wire rod is sheared, the divided movable blades constituting the movable blade portion hold the outer peripheral surface of the wire rod, so that the wire rod and the work do not incline during the shearing operation. Therefore, the perpendicularity of the cut surface of the work is improved, and the dimensional accuracy is improved. In addition, since the stopper member is not used, the cut surface of the work does not rub against the stopper member and the surface accuracy does not deteriorate. Therefore, according to the present invention, it is possible to improve both the dimensional accuracy and the surface accuracy of the cut surface of the workpiece manufactured by cutting.

It is a top view which shows typically the whole structure of the forging machine with which the wire rod cutting device of 1st Embodiment of this invention was incorporated. It is a front partial sectional view showing composition of a wire rod cutting device of a 1st embodiment. It is a side surface partial sectional view which shows the structure of a wire rod cutting device. It is a front view which removed the movable blade part from the wire rod cutting device, and mainly shows the configuration of the fixed blade part. It is a side view of the work produced in the comparative evaluation test. It is a figure of a graph showing a test result of a comparative evaluation test. It is a side surface partial sectional view which shows the structure of the wire rod cutting device of 2nd Embodiment.

  First, the overall configuration of a forging machine 9 incorporating the wire rod cutting device 1 of the first embodiment will be described with reference to FIG. As shown in the schematic plan view of FIG. 1, the forging machine 9 is a horizontal multi-step forging machine. The press machine 9 includes a frame 2, a ram 3, five sets of punches 41 and dies 44, a work transfer unit 49, a wire cutting device 1, a drive unit 90, and the like. The forging machine 9 sequentially carries out forging processing on the work in the first to fifth forging steps including the five sets of punches 41 and the dies 44. In FIG. 1, the first to fifth forging steps are arranged from the upper side to the lower side.

  The frame 2 is a housing for arranging the respective parts, and is made of iron and is robustly formed. The five die holders 21 are provided side by side in the width direction of the frame 2. The five dies 44 are replaceably attached to the front side (left side in FIG. 1) of each die holder 21. A predetermined working die is formed on the front side of each die 44.

  The ram 3 has a substantially rectangular shape in plan view, and reciprocates in the front-back direction with respect to the frame 2, that is, in the left-right direction in FIG. The five punch holders 31 are provided side by side in the width direction on the front side (right side in the drawing) of the ram 3. The five punches 41 are replaceably attached to the front side of each punch holder 31, and are arranged to face the dies 44, respectively. A predetermined working die is formed on the front side of each punch 41. Each punch 41 reciprocates together with the ram 3.

  The wire rod cutting device 1 is arranged adjacent to the first forging step. The wire rod cutting device 1 shears a wire rod having a circular cross section to manufacture a work, and supplies the work to the first forging step. As the wire rod, a long wire rod wound in a coil shape or a linear bar wire rod can be used. Further, examples of the material of the wire rod and the work include iron, aluminum, various alloys, and the like. Details of the wire rod cutting device 1 will be described later.

  The work transfer unit 49 is arranged from above the die holder 21 to the front of the die 44. The work transfer unit 49 may also be referred to as a transfer device. The work transfer unit 49 has six pairs of fingers that hold the work. The uppermost first finger pair grips the workpiece manufactured by the wire rod cutting device 1 and conveys it to the first forging process. The second to fifth finger pairs grip the work in the upstream forging process and convey it to the downstream forging process. The sixth finger pair on the most downstream side grips the work in the fifth forging step and conveys it to an unillustrated unloading section.

  A drive unit 90 is provided to reciprocally drive the ram 3. The drive unit 90 includes a main drive source 91, various transmission mechanisms, a cam mechanism, and the like. The main drive source 91 can be, for example, an induction motor or a synchronous motor that operates with a three-phase AC power supply. The drive unit 90 drives the work transfer unit 49 and a part of the wire rod cutting device 1 together. The drive force of the main drive source 91 is input to the crankshaft 95 that drives the ram 3 via the flywheel 92, the disc brake 93, and the speed reduction mechanism 94. Further, the driving force is branched and transmitted from the crankshaft 95 to the side shaft 97 via the pair of branch gears 96.

  The side shaft 97 branches and transmits the driving force upward. The driving force branched upward drives the transfer cam 98 to rotate. The transfer cam 98 drives the work transfer section 49. Further, six open-close cams 9A are connected so as to be rotationally driven from the side shaft 97 via the transfer drive 99. The open-close cams 9A are arranged at equal intervals in the width direction. The open-close cams 9A open and close the finger pairs respectively.

  Further, a pusher cam 9C, a feed cam 9D, and five kickout cams 9F are connected to the side shaft 97. The pusher cam 9C and the feed cam 9D are used in the wire rod cutting device 1. The five kickout cams 9F are arranged at equal intervals in the width direction and correspond to the positions of the first to fifth forging processes, respectively. The kickout cam 9F drives a kickout pin that projects a work from the die 44.

  Next, the configuration of the wire rod cutting device 1 of the first embodiment will be described in detail. FIG. 2 is a front partial cross-sectional view showing the configuration of the wire rod cutting device 1 of the first embodiment. Further, FIG. 3 is a side surface partial cross-sectional view showing the configuration of the wire rod cutting device 1. The right side of FIG. 3 corresponds to the rear side of the wire rod cutting device 1, and the left side of FIG. 3 corresponds to the front side of the wire rod cutting device 1. FIG. 4 is a front view in which the movable blade portion 7 is removed from the wire rod cutting device 1, and mainly the configuration of the fixed blade portion 6 is shown. The wire rod cutting device 1 includes a wire rod feeding unit 5, a fixed blade unit 6, a fixed-side grip drive unit 69, a movable blade unit 7, a grip drive unit 79, a cutting drive unit 8, and the like.

  The wire rod feeding unit 5 is a reciprocating feed mechanism that intermittently feeds the wire rod M by a predetermined length. As schematically shown in FIG. 3, the wire feeding portion 5 includes two guide rods 51, a movable grip portion 52, a drive member 53, a fixed grip portion 54, and the like. The two guide rods 51 are spaced apart from each other in the vertical direction and extend in the front-rear direction in parallel. The wire M is sent out in the sending direction from the rear side to the front side at the height between the two guide rods 51.

  The movable grip portion 52 is mounted near the front side of the two guide rods 51. As shown by the arrow S, the movable grip portion 52 can move forward along the guide rod 51 in the delivery direction and return along the reverse direction. The movable grip part 52 has a pair of grip parts 521 and a grip drive part 522. When the pair of grips 521 are closed, the wire M is sandwiched and gripped from above and below. In addition, the pair of grip portions 521 release the wire M by performing the opening operation. The grip drive unit 522 drives the opening / closing operation of the pair of grip units 521. A hydraulic drive mechanism can be used as the grip drive unit 522, but the grip drive unit 522 is not limited to this.

  The drive member 53 is coupled to the front side of the movable grip portion 52. The drive member 53 is driven by the above-described feed cam 9D and reciprocates in the front-rear direction by an operation distance corresponding to a predetermined length of the work. As a result, the movable gripper 52 reciprocates integrally with the drive member 53 for a predetermined length. The reciprocating motion of the movable grip portion 52 may be driven by another drive source different from the main drive source 91.

  The fixed grip portion 54 is fixedly attached to the two guide rods 51 near the rear side. The fixed grip portion 54 has a pair of grip portions 541 and a grip driving portion 542. When the pair of grip portions 541 are closed, the wire M is sandwiched and gripped from above and below. In addition, the pair of grip portions 541 release the wire M by performing the opening operation. The grip drive unit 542 drives the opening / closing operation of the pair of grip units 541. A hydraulic drive mechanism can be used as the grip drive unit 542, but the grip drive unit 542 is not limited to this.

  The grip portion 541 and the grip driving portion 542 of the fixed grip portion 54 can be the same as the grip portion 521 and the grip driving portion 522 of the movable grip portion 52. This can reduce the number of components and contribute to cost reduction. Further, the movable range of the movable grip portion 52 on the guide rod 51 and the fixed position of the fixed grip portion 54 can be changed. According to this, it is possible to easily deal with the change of the wire M or the work.

  The fixed blade portion 6 grips a portion other than the cutting range from the tip of the sent wire rod M to a predetermined length during the shearing operation. As shown in FIG. 3, the fixed blade portion 6 is provided on the front side of the wire rod feeding portion 5. Further, as shown in FIG. 4, the fixed blade portion 6 includes two divided fixed blades 61 and 62 and two fixed blade holders 65 and 66.

  As shown in FIG. 4, one fixed blade holder 65 is large and has a recess 67 on the left side in the drawing. The other fixed blade holder 66 has a small size and is housed in the recess 67 of the one fixed blade holder 65. A swing support portion 68 is provided near the lower portion of the fixed blade holder 66. The swing support portion 68 is supported by the fixed blade holder 65. The fixed blade holder 66 swings with respect to the fixed blade holder 65. The divided fixed blades 61 and 62 are respectively held by the inner side surfaces where the fixed blade holders 65 and 66 face each other.

  Each of the two divided fixed blades 61 and 62 is formed in a substantially semi-cylindrical shape that divides the cylinder into two equal parts. The inner diameter of the semi-cylindrical shape is approximately the same as the diameter of the wire M in the front portion 63 near the movable blade portion 7, and is slightly larger than the diameter of the wire M in the rear portion 64 (see FIG. 3). ). The two divided fixed blades 61 and 62 are arranged to face each other at an accurate front side position of the wire rod M sent out from the wire rod sending portion 5.

  The fixed-side grip drive unit 69 is provided so as to penetrate through the two fixed blade holders 65 and 66 toward the top. The fixed-side grip drive unit 69 drives the swing of the fixed blade holder 66. A hydraulic operation drive unit can be illustrated as the fixed-side grip drive unit 69, but the present invention is not limited to this.

  In FIG. 4, the fixed-side grip drive section 69 drives the fixed blade holder 66 clockwise around the swing support section 68. Then, the inner side surfaces of the two fixed blade holders 65 and 66 approach each other. As a result, the two divided fixed blades 61 and 62 are pressed against the wire M. In other words, the split fixed blades 61 and 62 grip almost the entire circumference of the outer peripheral surface of the portion on the rear side of the cutting range of the wire M. Therefore, the wire M is restrained, does not move, and does not incline, and is in a state suitable for shearing operation.

  Further, the fixed-side grip drive section 69 can drive the fixed blade holder 66 counterclockwise around the swing support section 68. Then, the inner side surfaces of the two fixed blade holders 65 and 66 move away from each other. Accordingly, a gap is formed between at least one of the two fixed fixed blades 61 and 62 and the wire M. In other words, the split fixed blades 61 and 62 release the outer peripheral surface of the wire M. Therefore, the wire M can be sent out.

  The movable blade portion 7 grips and releases the outer peripheral surface of the cutting range of the wire M. As shown in FIG. 3, the movable blade portion 7 is provided on the front side of the fixed blade portion 6. Further, as shown in FIG. 2, the movable blade portion 7 is configured to include two divided movable blades 71 and 72 and two movable blade holders 75 and 76.

  As shown in FIG. 2, the left movable blade holder 75 is large and wide, and the right movable blade holder 76 is small and narrow. The two movable blade holders 75 and 76 are arranged side by side. A swing support portion 78 is provided near the upper part of the right movable blade holder 76. The swing support portion 78 is supported by the movable blade holder 75. The movable blade holder 76 swings with respect to the movable blade holder 75. The divided movable blades 71 and 72 are respectively held on the side surfaces of the movable blade holders 75 and 76 that face each other.

  Each of the two split movable blades 71 and 72 is formed into a substantially semi-cylindrical shape that divides the cylinder into two equal parts. The inner diameter of the semi-cylindrical shape substantially matches the diameter of the wire M. The length of the semi-cylindrical shape may be larger or smaller than the predetermined length of the work. When the wire rod M is sent out, the two split movable blades 71 and 72 are arranged facing each other at the correct front position of the split fixed blades 61 and 62. In FIG. 3, the length of the movable split blades 71, 72 in the front-rear direction is larger than the predetermined length of the work. Therefore, the tip of the sent wire rod M stays inside the movable blade portion 7.

  The grip drive unit 79 is provided so as to penetrate through the two movable blade holders 75 and 76 toward the bottom. The grip drive unit 79 drives the swing of the movable blade holder 76. A hydraulic operation drive unit can be exemplified as the grip drive unit 79, and the grip drive unit 79 is not limited to this.

  In FIG. 2, the grip drive section 79 drives the movable blade holder 76 clockwise around the swing support section 78. Then, the inner side surfaces of the two movable blade holders 75 and 76 approach each other. As a result, the two movable split blades 71, 72 are pressed against the wire M. In other words, the split movable blades 71, 72 grip almost the entire circumference of the outer peripheral surface of the cutting range of the wire M. Therefore, the wire M and the workpiece in the middle of shearing are restrained, do not move, and do not incline, and the situation is suitable for shearing operation.

  Further, the grip drive unit 79 can drive the movable blade holder 76 counterclockwise about the swing support unit 78. Then, the side surfaces of the two movable blade holders 75 and 76 move away from each other. Thereby, a gap is formed between at least one of the two movable split blades 71 and 72 and the sheared work. In other words, the split movable blades 71 and 72 release the outer peripheral surface of the work. Therefore, it becomes a situation where the manufactured work can be pushed out.

  As shown in FIG. 2, the cutting drive unit 8 is configured using a hydraulic operation mechanism including a hydraulic servo valve 81, a hydraulic piston 84, and the like. The hydraulic servo valve 81 supplies / discharges hydraulic fluid to / from the front chamber 85 and the rear chamber 86 of the hydraulic piston 84 via the two oil passages 82 and 83. As a result, the hydraulic piston 84 moves in the direction indicated by the arrow C, and drives the movable blade portion 7 and the grip drive portion 79 as a whole in the right direction in FIG. 2 by the stroke length SL. At this time, the movable blade portion 7 operates in a direction intersecting with the wire M.

  The cutting drive unit 8 is provided separately from the main drive source 91 that drives the forging operation. According to this, the cutting drive unit 8 can always drive the shearing operation at a high speed without being affected by the operation speed of the forging operation, and can realize the hammer cutter method. The hammer cutter method improves the accuracy of shearing the work. The cutting drive unit 8 may be other than the hydraulic operation mechanism described above.

  Next, the operation of the wire rod cutting device 1 of the first embodiment will be described. During the shearing operation, the movable gripping portion 52 of the wire rod feeding portion 5 grips the wire rod M at the position where it moves forward in the feeding direction, and the fixed gripping portion 54 grips the wire rod M. After the shearing operation is completed, the fixed gripping portion 54 continues to grip the wire rod M, and the movable gripping portion 52 releases the wire rod M and moves back in the opposite direction. Next, the movable gripper 52 grips the wire M, and the fixed gripper 54 releases the wire M. Next, the movable gripper 52 moves forward in the feeding direction by a predetermined length while gripping the wire M. Next, the fixed grip portion 54 grips the wire M, and the feeding operation is completed.

  While the wire rod M is being sent out, the fixed-side grip drive unit 69 drives the divided fixed blades 61 and 62 to release the outer peripheral surface of the wire rod M. Similar to the fixed-side grip drive unit 69, the grip drive unit 79 drives the divided movable blades 71 and 72 to release the outer peripheral surface of the wire M. When the feeding operation is completed, the fixed-side grip drive unit 69 drives the divided fixed blades 61 and 62 to grip the outer peripheral surface of the wire M. Similar to the fixed-side grip drive unit 69, the grip drive unit 79 drives the divided movable blades 71 and 72 to grip the outer peripheral surface of the wire M. When both gripping movements are complete, the shearing movement is ready.

  Next, the cutting drive unit 8 moves the entire movable blade unit 7 and the grip drive unit 79 forward. The movable blade portion 7 operates in a direction intersecting with the wire rod M and shears the wire rod M with the fixed blade portion 6 to manufacture a work. During the shearing operation, the outer peripheral surface of the wire M is gripped and constrained by the movable gripper 52, the fixed gripper 54, the fixed blade 6, and the movable blade 7. Therefore, the wire M and the workpiece in the middle of shearing do not move and are not inclined with respect to the feeding direction.

  After the movable blade portion 7 moves in the intersecting direction, the grip drive portion 79 drives the divided movable blades 71 and 72 to release the outer peripheral surface of the work. Then, the pusher cam 9C described above drives the push pin (not shown). The push pin pushes out the work from the movable blade portion 7 and transfers it to the work transporting section 49. After that, the cutting drive unit 8 moves the movable blade unit 7 and the grip drive unit 79 back to return the movable blade unit 7 to the correct front position of the fixed blade unit 6.

  In addition, after the shearing operation is completed, the fixed-side grip drive unit 69 drives the divided fixed blades 61 and 62 to release the outer peripheral surface of the wire M. This enables the next feeding operation of the wire M. With the above, production of one work is completed, and production of the next work is started.

  Next, the operation and effect of the wire rod cutting device 1 of the first embodiment will be described with reference to the results of the comparative evaluation test. In the comparative evaluation test, the work W was manufactured using the wire cutting device 1 of the first embodiment and the wire cutting device of the comparative example, and the dimensional accuracy was comparatively evaluated. The wire rod cutting device of the comparative example is different from that of the first embodiment in that the wire rod feeding unit 5 and the cutting drive unit 8 similar to those in the first embodiment are used, and a ring-shaped fixed blade portion and a ring-shaped movable blade portion are used. The ring-shaped fixed blade portion and the movable blade portion have inner diameters larger than the diameter of the wire rod M and do not grip the outer peripheral surface of the wire rod M. In addition, in the first embodiment and the comparative example, the fixed blade portion 6 and the movable blade portion 7 have a clearance of 0.3 mm, which is the same.

  FIG. 5 is a side view of the work W manufactured in the comparative evaluation test. As the test material, a wire rod M equivalent to carbon steel S10C for machine structure (JISG 4051) was used. The wire M has a circular cross section with a diameter D of 10 mm, and the tip surface FS has a good perpendicularity. Here, since the work W manufactured during the normal operation has the cut surfaces CS on both sides in the length direction, the evaluation method is difficult. For this reason, in the comparative evaluation test, one side of the work W has a trimmed front end surface FS to facilitate the evaluation.

  Further, the predetermined length L of the workpiece W to be manufactured, that is, the delivery dimension of the wire rod delivery portion 5 was changed from 5 mm to 10 mm at a pitch of 1 mm. In other words, the length ratio R (= L / D) representing the ratio of the predetermined length L to the diameter D of the work W was changed in the range of 0.5 to 1.0. Then, the error dimension E (see FIG. 5) representing the quality of the squareness of the cut surface CS of the manufactured work W was measured and shown in the graph. The error dimension E being zero means that the cut surface CS is orthogonal to the length direction of the work W (the feeding direction of the wire M). Further, the large error dimension E means that the cut surface CS is largely inclined with respect to the length direction of the work W, and the perpendicularity is poor.

  FIG. 6 is a graph showing the test results of the comparative evaluation test. The horizontal axis of FIG. 6 represents the length ratio R, and the vertical axis represents the error dimension E. The broken line graph shows the test results of the wire rod cutting device of the comparative example. The solid line graph shows the test results of the wire rod cutting device 1 of the first embodiment. The dashed-dotted line graph shows the test results of the wire rod cutting device 1A according to the second embodiment described later.

  First, focusing on the test result (broken line) of the wire rod cutting device of the comparative example, the error dimension E is about 0.5 mm at the length ratio R = 1.0. Further, as the length ratio R becomes smaller, the error dimension E tends to gradually increase. The error dimension E is about 1.5 mm, which is the maximum at the length ratio R = 0.5. On the other hand, when the length ratio R exceeds 1 and becomes large, the error dimension E decreases, so that there is not much problem in performance.

  Next, focusing on the test result (solid line) of the wire rod cutting device 1 of the first embodiment, the error dimension E is about 0.1 mm at the length ratio R = 1.0. Further, the tendency that the error dimension E gradually increases as the length ratio R becomes smaller is similar to the comparative example. Then, when the length ratio R = 0.5, the error dimension E is about 1.3 mm, which is the maximum. The error dimension E is better than the comparative example under all the test conditions of the length ratio R, and the improvement effect of about 0.2 to 0.8 mm is recognized.

  The above-mentioned effect becomes remarkable when the length ratio R is 1 or less. Further, the above-mentioned effects are produced by the fixed blade portion 6 and the movable blade portion 7 gripping the wire rod M, respectively. According to the results of tests conducted separately, it is confirmed that the movable blade portion 7 makes a large contribution and the fixed blade portion 6 makes a small contribution.

  In the wire rod cutting device 1 of the first embodiment, when the wire rod M is sheared, the split fixed blades 61, 62 and the split movable blades 71, 72 grip the outer peripheral surface of the wire rod M, so the wire rod M is in the middle of the shearing operation. The work W never tilts. Therefore, the perpendicularity of the cut surface CS of the work W is improved, and the dimensional accuracy is improved. In addition, since the stopper member is not used, the cut surface CS of the work W does not rub against the stopper member and the surface accuracy does not deteriorate. Therefore, it is possible to improve both the dimensional accuracy of the workpiece W manufactured by cutting and the surface accuracy of the cut surface.

  In addition, in the forging machine 9 in which the wire rod cutting device 1 is incorporated, since the work W as the raw material is good, the precision of the product produced by the forging process is improved. Further, the number of required forging steps can be reduced depending on the dimensional error allowed after the forging work W. Further, the fixed side grip drive unit 69, the grip drive unit 79, and the cutting drive unit 8 operate independently of the main drive source 91. Therefore, the wire rod cutting device 1 can be unitized as a configuration that does not use a cam mechanism or the like. According to this, the unit of the wire rod cutting device 1 can be incorporated into various types of forging machines to reduce the cost.

  Next, the wire rod cutting device 1A according to the second embodiment will be described mainly with respect to the points different from the first embodiment. FIG. 7: is a side surface partial cross section figure which shows the structure of 1 A of wire rod cutting devices of 2nd Embodiment. In the second embodiment, the stopper member 7A is added. As shown in the drawing, the stopper member 7A is coaxially arranged on the front side of the movable blade portion 7.

  The stopper member 7A is formed in a stepped columnar shape including a base body portion 7B on the front side and a pressing portion 7C on the rear side. The base portion 7B has a columnar shape with a diameter larger than that of the wire M and is short in the front-rear direction, and is arranged on the front side of the movable blade portion 7. The pressing portion 7C has a columnar shape substantially equal to the diameter of the wire M, and is arranged so as to enter the inside from the front side of the movable blade portion 7. The length of the pressing portion 7C in the front-rear direction is variably set according to the predetermined length L of the workpiece W to be manufactured.

  7 A of stopper members are attached to the fixed seat (not shown) extended from the movable blade holder 75, and a position in the front-back direction is fixed. In the second embodiment, the movable grip portion 52 of the wire rod feeding unit 5 is not restricted by the predetermined length L of the work W, and moves forward until the tip of the wire rod M contacts the stopper member 7A. 7 A of stopper members operate | move in a cross direction with the movable blade part 7 in the state in which the front-end | tip of the sent out wire rod M was pressed. During the shearing operation, the stopper member 7A applies an external force in the axial direction to the tip of the sent wire rod M to prevent the tip of the wire rod M from being displaced forward.

  In the wire rod cutting device 1A of the second embodiment, the split fixed blades 61 and 62 and the split movable blades 71 and 72 grip the outer peripheral surface of the wire rod M when shearing the wire rod M as in the first embodiment. Further, an external force acts on the tip of the wire M from the stopper member 7A. The effect of the superposition of these two points is shown in the one-dot chain line graph of FIG.

  More specifically, when the length ratio R = 1.0, the error dimension E is about 0.1 mm, which is almost the same as the first embodiment. Nevertheless, when the length ratio R becomes smaller, the error dimension E becomes higher than that in the first embodiment. Then, when the length ratio R = 0.5, the error dimension E is about 0.5 mm, and an improvement effect of about 0.8 mm is recognized as compared with the first embodiment. In addition, the stopper member 7A moves in the intersecting direction together with the work W to be sheared. Therefore, the cut surface of the work W does not rub against the stopper member 7A, and the surface accuracy becomes good.

  The fixed blade portion 6 and the movable blade portion 7 may be divided into three or more. In addition, the fixed blade portion 6 and the movable blade portion 7 may hold three or more discrete positions instead of holding the entire outer peripheral surface of the wire M. Furthermore, the fixed-side grip drive unit 69 may be omitted by making the fixed blade portion 6 that contributes to the dimensional accuracy of the work W smaller than the movable blade portion 7 as a ring-shaped integrated product.

  Further, in the second embodiment, when the work W is longer than the split movable blades 71 and 72, the stopper member can be simplified into a flat plate shape larger than the diameter D of the wire rod M. Further, in the second embodiment, it is possible to use a roller feeding mechanism for the wire rod feeding unit 5. The present invention can be variously modified and applied in addition to the above.

1, 1A: Wire rod cutting device 2: Frame 3: Ram 41: Punch 44: Die 49: Work transfer part 5: Wire rod sending part 52: Movable gripping part 54: Fixed gripping part 6: Fixed blade part 61, 62: Split fixing Blades 65, 66: Fixed blade holder 69: Fixed side grip drive unit 7: Movable blade unit 71, 72: Divided movable blades 75, 76: Movable blade holder 79: Grip drive unit 7A: Stopper member 8: Cutting drive unit 9: Pressing machine 90: Drive unit 91: Main drive source M: Wire material W: Work FS: Tip surface CS: Cutting surface D: Diameter L: Predetermined length R: Length ratio E: Error dimension

Claims (7)

A wire rod feeding unit that intermittently feeds the wire rod by a predetermined length,
A fixed blade portion that supports a portion other than the cutting range from the tip of the sent wire rod to the predetermined length,
A movable blade portion configured by a plurality of divided movable blades for gripping and releasing the outer peripheral surface of the cutting range of the wire rod,
When the wire rod is delivered, the split movable blade releases the outer peripheral surface, and when the wire rod is cut, the split movable blade drives the movable blade portion so as to hold the outer peripheral surface, and a grip drive unit. ,
A cutting drive unit that drives the movable blade portion in a direction intersecting with the wire rod and shears the wire rod with the fixed blade portion to produce a work,
A wire rod cutting device.   The wire rod cutting device according to claim 1, wherein the wire rod feeding unit feeds out the wire rod by the predetermined length equal to or less than a diameter of a circular cross section of the wire rod.   The wire rod cutting device according to claim 1, wherein the grip drive unit is a hydraulic operation drive unit. The fixed blade portion is composed of a plurality of divided fixed blades for gripping and releasing the outer peripheral surface other than the cutting range of the wire rod,
A fixed-side grip drive that drives the fixed blade portion so that the split fixed blade releases the outer peripheral surface when the wire rod is sent out and the split fixed blade grips the outer peripheral surface when cutting the wire rod. Further comprises a section,
The wire rod cutting device according to claim 1.   The wire rod cutting device according to any one of claims 1 to 4, further comprising a stopper member that moves in the intersecting direction together with the movable blade portion in a state where the tip of the fed wire rod is pressed.   The wire rod feeding unit holds the wire rod, moves forward in the feeding direction by the predetermined length, releases the wire rod, and moves back in the opposite direction, and a fixed gripper that holds and releases the wire rod. The wire rod cutting device according to claim 1, further comprising a grip portion.   It is a wire rod cutting device incorporated in a press machine, Comprising: The said cutting drive part is provided separately from the main drive source which drives the press operation of the said press machine, The wire rod cutting as described in any one of Claims 1-6. apparatus.

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