JP2011045899A - Precise plastic working method and precise plastic working device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a shear plane being excellent in dimension accuracy, being smooth, and having a reduced fracture surface, and enables an increase in cycle time of a precise plastic working device. <P>SOLUTION: When a workpiece W is punched by a punch 11, a press-in protrusion 23 of a stripper plate 20 is press-fitted into the workpiece (primary press-fitting-working process), and the edge tip 11a of the punch 11 is driven to the workpiece W while pressing in a stress attempting to expand in a direction (horizontal direction) perpendicular to a working direction by the press-in protrusion 23. When the edge tip 11a of the punch 11 exceeds the press-fitting amount of the press-in protrusion 23 and reaches the middle of the workpiece W, a secondary press-fitting operation allowing the press-in protrusion 23 to be further press-fitted into the workpiece W interlocked with the punching operation of the punch 11 is started, the material of the workpiece W is supplied to the shear part of the workpiece W by the secondary press-fitting operation of the press-in protrusion 23 (secondary press-fitting-working process). Accordingly, the beautiful shear plane is obtained with no material at the shear part fluidized and no fracture surface generated by the shortage of the material. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a precision plastic working method and apparatus capable of achieving precision plastic working equivalent to or better than fine blanking with an inexpensive general-purpose press without using an expensive fine blanking press. In particular, the present invention relates to a material in a plastic processing portion of a workpiece over almost the whole of the shearing process in plastic processing in which a shear surface such as punching by punching, shearing or half punching is used as the outer peripheral surface of the product. TECHNICAL FIELD The present invention relates to a precision plastic working method for controlling the fluidity of steel and a precision plastic working apparatus for realizing the method.

  In general, in shear processing such as punching a workpiece with a general-purpose press device, the occurrence of microcracks in the sheared part is inevitable, so the sheared surface becomes rough, and when the sheared surface is used as the outer peripheral surface of the product After the shearing process such as punching, the desired cross-sectional properties and processing accuracy could not be obtained unless the sheared surface was finished by cutting or grinding. For this reason, as a precision shearing method that does not require finishing processing such as cutting and grinding on the sheared surface after punching, fine blanking (Fine Blanking) as shown in Patent Documents 1 to 3, for example, or non- A precision machining method called FHS (Fine Hold Stamping) method as shown in Patent Documents 1 and 2 is known.

  This fine blanking process uses a punch and die with a small clearance, and includes a plate pressing member and a reverse pressing member that form a knife-edge-shaped ring surrounding the processing surface. It is intended to prevent the occurrence of cracks on the shearing surface by generating a high compressive stress inside the work material by increasing the ductility of the work material. It is a precision processing method aimed at obtaining. That is, while pressing in the direction perpendicular to the material of the work part of the workpiece, a V-shaped annular indentation protrusion having a cross-section surrounding the punching hole is press-fitted into the work to form an annular V-shaped groove around the punching hole. This is a processing method in which the ductility of the workpiece near the shearing surface is increased to obtain a shearing surface that is smooth and has few fracture surfaces.

  Non-patent document 1 and non-patent document 2 disclose the FHS method as a practical application of precision machining technology similar to this, and “... therefore, FHS prevents the“ escape ”of this material. Therefore, the shape of the mold was changed, and the material was held by the mold so that “escape” did not occur. By adopting this mechanism, the mold and the material are not misaligned, and it is possible to perform precise processing ... "and" In FB, there is room for the material to escape in the lateral direction of the blank. FHS. Then, the blank side is covered with a punch to prevent the material from escaping. "

  In Patent Document 1, when the sprocket teeth are formed, the tooth surface accuracy is greatly improved by forming a V-groove by coining slightly inside the sprocket root formation part at the same time as the punching process or in a separate process. The steel plate sprocket is a sprocket in which the tooth profile is formed over the entire outer peripheral surface of the steel plate dish by pressing. A technique is disclosed in which V-grooves are formed by continuous or non-continuous coining along the line.

  Patent Document 2 discloses a precision punching method, which is inexpensive and easy to maintain, but aims to surpass the conventional fine blanking and facing die methods, and uses an upper and lower die by a hydraulic press. A technique is disclosed in which a metal flow-inhibiting wall is formed at a position opposed to the front and back surfaces of the material by forming indentation deep grooves on the front and back surfaces of the material.

  Patent Document 3 aims to solve the problems of sprockets formed by fine blanking and to provide sprockets with tooth tips formed by two processing steps. In the sprocket made of steel plate, after the back surface of the tip of the tooth tip is formed in a cross-sectional R shape by the cutting edge shape of the die used for the fine blanking process, the surface of the tip shape of the tooth tip is pressed. The technique which solves a subject by being formed in the substantially same shape as the said cross-sectional R shape is disclosed.

JP 2002-1449 A JP 2002-333121 A JP 2007-216293 A

http: // www. Toyota-boshoku. co. jp / pdfset / investment / manual / mr2008 / p19-22. pdf Special Feature “Challenge to develop innovative press method for world-class high-speed machining and accuracy” http: // techon. nikkeibp. co. jp / article / NEWS / 20088081/156694 / "Thick steel plate is precision pressed at 100 spm, Toyota Boshoku reveals part of new construction method" FHS ""

  In recent years, with the increasing awareness of environmental protection internationally, for example, in order to achieve the “2010 10% reduction target for CO2 emissions” set by automobile manufacturers to reduce environmental impact, weight reduction of vehicle bodies and drive parts is required. It has been. In addition, as overseas production by automakers and parts manufacturers expands, both high functionality and high productivity are required to reduce costs with international competitiveness. In such a situation, metal stamping is a process that is highly productive and effective in reducing the cost of parts, so there is a need for automobile manufacturers to expand the use of metal stamping. And as a production method of a metal press work product, there are the fine blanking method and the general press method mentioned above. And the fine blanking method has high processing accuracy, and it is a processing method with excellent dimensional accuracy that can be produced only by press processing without post-processing, even for press products that conventionally required finishing by a machine tool after press processing. Therefore, it is applied to highly functional parts such as gears, brakes and transmission parts. However, on the other hand, there are problems that the production speed is slow and that a fine blanking press device dedicated to the fine blanking method is indispensable as compared with a general press. On the other hand, the general press method has a problem that the product accuracy is low, but has an advantage that the production speed is high and processing can be performed by a highly versatile press.

  In other words, the number of cycles of a general press machine is approximately 80 strokes per minute (80 strokes / min), whereas a fine blanking process can punch a workpiece only at about 30 strokes / min. In fine blanking, if the cycle is increased to 80 strokes / min as in a general press die, the flow of material in the vicinity of the shearing surface cannot follow the punching speed, resulting in a fracture surface. Therefore, there is a problem that a desired quality cannot be obtained.

  On the other hand, according to the FHS method described in Non-Patent Documents 1 and 2, “It is possible to produce about 100 pieces per minute by pressing a steel plate with a thickness of 4.3 mm, and the yield rate is almost 100. It is said that 100 strokes could be realized in 1 minute, but the specific solution to the above problem is to prevent the occurrence of “runaway” by pressing the material with a mold. Other than this, it is not clear only from the description of the document.

  In the present invention, a fine blanking process using an expensive fine blanking apparatus can be performed without using an expensive fine blanking press apparatus and using an inexpensive general-purpose press apparatus among many known fine blanking processing techniques. The goal is to achieve precision shearing equivalent to or higher than ranking. In other words, the present invention makes it possible to achieve a high cycle by using a general-purpose press device to increase productivity, and to provide a shear surface with a good shear surface, excellent dimensional accuracy, and a smooth, low fracture surface. An object of the present invention is to provide a precision shearing method and apparatus capable of obtaining a cheaper and higher quality product.

  As described above, the present invention is intended to achieve precision shearing more than fine blanking by using an inexpensive general-purpose press without using an expensive fine blanking press as the press used. The cross-sectional product accuracy is ± 0.01 mm, the surface roughness is Ra 1.6 μm, the productivity is the number of strokes 80 strokes / min, and the mold life / 1 polishing is targeted for 100,000 shots.

  In the fine blanking process as described above, including the present invention, the reason for obtaining a clean shear surface is to explain the effect of increasing the ductility of the material in the processed part or increasing the fluidity of the material. It is common. However, there is still an incomplete part of the clear technical verification of this effect. Therefore, in the present invention, focusing on the effect of enhancing the fluidity of the material to the processed portion, the explanation will be made using terms such as “fluidity” or “enhancing fluidity” of the material. It is not intended to be a technically strictly limited interpretation of the function.

The precision plastic working method according to claim 1 is a plastic working method for obtaining a product by plastic working of a workpiece with a movable jig and a fixed jig, and a sharp indentation protrusion is provided in the vicinity of the movable jig. Set up
(A) Simultaneously improving the fluidity of the work material during plastic working by pressing the sharp pushing protrusion into the work prior to the movable jig as the movable jig descends. A primary press-fitting and machining process that applies compressive stress to the workpiece and processes it with a movable jig;
(B) By further driving the movable jig to further plastically process the workpiece by the movable jig, the movable jig is moved in a state preceding the sharp pushing protrusion. The secondary is processed by the movable jig by further pressing the indentation protrusion into the work in cooperation with the lowering movement of the tool to increase the fluidity of the work material during plastic working and at the same time applying compressive stress to the work It features a press-fitting and processing process.

  According to the precision plastic working method of claim 1, the primary plasticity by the movable jig and the fixed jig is lowered by lowering the movable jig in a state where the primary press-fitting and machining process for causing a part of the indentation protrusion to bite into the workpiece is performed. The machining operation is started. During the plastic working operation by this movable jig, the secondary press-fitting / working process in which the push-in protrusion is further pushed into the work is started, so that further fluidization of the material into the plastic work is smoothed and simultaneously compressed into the work. By applying stress, it is possible to suppress the occurrence of fracture surfaces due to microcracks even in the secondary plastic working operation.

The precision plastic working method according to claim 2, wherein a punch, a die, a knockout punch arranged so as to be movable up and down in conjunction with the punch, and a sharp indentation protrusion in the vicinity of the outside of the punch are formed. In a plastic working method comprising a stripper plate, and punching a workpiece while sandwiching the workpiece by the stripper plate, a die, a punch and a knockout punch,
(A) Before pressing the punch into contact with the workpiece surface, the pressing projection of the stripper plate is press-fitted into the workpiece, and the pressing projection is pressed into the workpiece around the plastic working portion, and the workpiece material at the time of plastic working The primary press-fitting and machining process, which increases the fluidity of the workpiece and simultaneously applies a compressive stress to the workpiece and processes it with a punch,
(B) The plastic working of the workpiece is further advanced by further driving of the punch, and in the state in which the punch precedes the pushing projection of the stripper plate, the punch is driven and moved together with the stripper. The press projection of the plate is further pushed into the workpiece to improve the fluidity of the workpiece material at the time of plastic working, and at the same time, it is provided with a secondary press-fitting and machining process in which a compressive stress is applied to the workpiece and machining is performed by a punch. And

  According to the precision plastic working method of claim 2, the primary plastic working operation by the cutting edge of the punch is started by lowering the punch in a state where the primary press-fitting / working process for causing a part of the indentation protrusion to bite into the work is performed. The By starting the secondary press-fitting / working process in which the pushing protrusion is further pushed into the workpiece during the plastic working operation by this punch, further fluidization of the material in the plastic working portion is performed smoothly, and at the same time compressive stress is applied to the work. In addition, it is possible to suppress the generation of fracture surfaces due to microcracks even in the secondary plastic working operation.

The precision plastic processing method according to claim 3 is a plastic processing method for obtaining a product by plastic processing of a workpiece with a movable jig and a fixed jig, and a sharp indentation protrusion is provided in the vicinity of the movable jig. The plastic working of the workpiece is
A primary press-fitting / working process in which plastic working is performed while supplying the material to the plastic working part of the work by controlling the fluidity of the work material by press-fitting the indentation protrusions around the plastic working part of the work to a predetermined amount; and A second press-fitting / working step of performing plastic working while further supplying material to the plastic working portion of the work by increasing the fluidity of the work material by further press-fitting operation of the indentation protrusion is provided.

  According to the precision plastic working method of claim 3, for example, when a workpiece having a thickness of about 6 mm is punched out by a punch, the workpiece is plastically processed in a state where a primary press-fitting / machining process for causing the pushing protrusion to bite into the workpiece by about 0.9 mm is performed. Is done. At this time, the workpiece is started to be driven by the cutting edge portion of the punch while the workpiece material is about to spread in a direction (horizontal direction) perpendicular to the processing direction of the punch by the pressing protrusion that has bite into the workpiece. Thereafter, the push-in protrusion is further moved in a state in which the cutting edge of the punch exceeds the primary press-fitting amount (0.9 mm) of the push-in protrusion, for example, to a depth of about 3 mm, which is about half the workpiece plate pressure with respect to the work. Starts the secondary press-fitting / machining operation to bite the workpiece. The material of the workpiece is further supplied to the plastic processing portion of the workpiece by the secondary press-fitting and processing operation of this indentation protrusion, and further fluidization of the material in the plastic processing portion is performed smoothly, and at the same time, compressive stress is applied to the workpiece. Thus, even if the punch is speeded up, a beautiful plastic working surface can be obtained without causing a fracture surface due to insufficient material in the plastic working portion.

  The precision plastic working method according to a fourth aspect is characterized in that the further pushing operation of the pushing projection is operated in synchronism with the lowering operation of the movable jig or the punch.

  According to the precision plastic working method of claim 4, further supply of the work material to the plastic working portion at the time of the secondary press-fitting / working operation of the indentation protrusion is achieved in synchronization with the movement of the movable jig or the punch. , More fluidization of the material in the plastic working part is performed smoothly and at the same time compressive stress is applied to the workpiece, and even if the punch is speeded up, the fracture surface due to the lack of material in the plastic working part does not occur and it is beautiful A plastic working surface can be obtained.

  The precision plastic working apparatus according to claim 5 is a plastic working apparatus for obtaining a product by plastic working of a work with a movable jig and a fixed jig, and the work is not applied to the product as the movable jig descends. A push-in protrusion that is pressed into the vicinity of the product, and the tip of the push-in protrusion is arranged ahead of the top of the movable jig, and the movable jig is placed on the workpiece surface. Before pressing, the indentation protrusion is press-fitted into the workpiece to increase the fluidity of the workpiece material during plastic processing, and the plastic processing of the workpiece by the movable jig further proceeds by further driving of the movable jig. In this state, the pushing protrusion is further pushed together with the lowering operation of the movable jig.

  According to the precision plastic working apparatus of the fifth aspect, when the work is placed on the fixing jig and the descending of the pushing protrusion is started, the pushing protrusion comes into contact with the upper surface of the work, and then the pushing protrusion is lowered. Realizes the primary press-fitting and machining process where the protrusions are press-fitted into the workpiece. By this primary press-fitting and processing step, a groove portion having a V-shaped cross section surrounding the cutting edge portion of the movable jig is formed on the workpiece. Thus, the driving operation of the movable jig is started in a state where the workpiece is sandwiched from above and below by the pushing protrusion and the fixed jig. When the cutting edge of the movable jig exceeds the primary press-fitting amount of the pressing protrusion and reaches a position deeper than the groove of the pressing protrusion, the pressing protrusion further bites into the work in cooperation with the driving operation of the movable jig. The secondary press-fitting and processing process is started. By further pushing-in operation of the push-in protrusion and driving-in operation by the movable jig, work material is supplied to the plastic processing part of the work by pressing-in operation of the push-in protrusion, and at the same time, compressive stress is applied to the work. I will let you.

  According to a sixth aspect of the present invention, there is provided a precision plastic working apparatus comprising: a die for placing a workpiece; a stripper plate disposed opposite to the die; a punch slidably disposed on the stripper plate; A pressing protrusion provided on the lower surface side, a knockout punch that is slidably disposed on the die so as to face the punch, a lifting drive means for driving the punch up and down, and a press-fitting drive that press-fits the pressing protrusion into the workpiece The press-fitting drive means is configured to press-fit the pushing protrusion into the workpiece before the punch contacts the workpiece surface, and the workpiece is plastically processed by the punch by further driving the punch. Is further advanced, the push-up driving means cooperates with the punch driving operation to further push the pushing protrusion. Characterized in that the sea urchin configuration.

  According to the precision plastic working apparatus of the sixth aspect, when the work is placed on the die and the pressing protrusion starts to be lowered by the press-fitting driving means, the pressing protrusion is lowered after the pressing protrusion comes into contact with the upper surface of the work. Realizes the primary press-fitting and machining process in which the indentation protrusion is press-fitted into the workpiece. By this primary press-fitting / processing step, a groove having a V-shaped cross section surrounding the cutting edge of the punch is formed in the work. In this manner, the punch driving operation is started in a state where the workpiece is sandwiched from above and below by the pressing protrusion and the die. Then, when the punch blade edge exceeds the primary press-fitting amount of the indentation protrusion and reaches a position deeper than the groove of the indentation protrusion, the secondary press-fitting that causes the indentation protrusion to further bite into the workpiece in cooperation with the punching operation. The machining process is started. By further pushing-in operation of the indentation protrusion and driving-in operation by punching, the workpiece material is further supplied to the plastic processing part of the workpiece by press-in operation of the indentation protrusion, and at the same time, compressive stress is applied to the workpiece. become.

  The precision plastic working apparatus according to claim 7 is characterized in that the further pushing operation of the pushing projection is operated by a cam mechanism in cooperation with the lowering operation of the movable jig or the punch.

  According to the precision plastic working apparatus of claim 7, further supply of the work material to the plastic working portion at the time of the secondary press-fitting operation of the indentation protrusion is achieved in cooperation with the movement of the movable jig or the punch, Further fluidization of the material in the plastic working portion is smoothly performed, and at the same time, a compressive stress is applied to the workpiece, and a clean plastic working surface is obtained. The fluidity of the material corresponding to the workpiece material can be obtained by appropriately selecting the cam shape.

  The precision plastic working apparatus according to claim 8 is configured such that the further pushing operation of the pushing protrusion is operated in synchronization with the lowering operation of the movable jig or the punch by an engagement ring having a predetermined thickness. It is characterized by that.

  According to the precision plastic working apparatus of the eighth aspect, further supply of the work material to the plastic working portion at the time of the secondary press-fitting operation of the indentation protrusion is achieved in synchronization with the movement of the movable jig or the punch. Further fluidization of the material in the processed part is performed smoothly, and at the same time, compressive stress is applied to the workpiece. Even if the punch is speeded up, a fracture surface due to lack of material does not occur, and a beautiful plastic processed surface can be obtained. It is done.

  According to a ninth aspect of the present invention, the stripper plate includes an insertion hole through which the punch is slidably fitted, and the inner inclined surface of the pushing projection and the insertion hole are continuous. It is characterized by that.

  According to the precision plastic working apparatus of the ninth aspect, since the plastic working portion of the workpiece formed by the punch and the groove portion by the indentation protrusion are constituted by a continuous surface, the groove portion and the plastic working portion of the workpiece are formed. The closer the distance is, the more effective the fluidization of the material in the vertical direction by the indentation protrusions, and the further fluidization of the material by the indentation protrusions during the secondary press-fitting and processing of the indentation protrusions is performed at the same time. Compressive stress can be applied to the workpiece.

  According to a tenth aspect of the present invention, there is provided a precision plastic working apparatus in which at least a plastic working portion surface of the movable jig and the fixed jig is subjected to a metal surface treatment such as a WPC treatment or a shot peening treatment.

  According to the precision plastic processing apparatus of claim 10, at least the surface of the plastic processing portion of the movable jig and the fixed jig is formed with a fine and dense structure on the surface by WPC processing or shot peening processing, thereby increasing the hardness. Has been. At the same time, by changing to fine dimples, the friction and wear characteristics as the surface properties of the movable jig and the fixed jig are improved, and the dimples become an oil reservoir for lubricating oil and improve the lubricating action.

  The precision plastic working apparatus according to an eleventh aspect is characterized in that a metal surface treatment such as a WPC treatment or a shot peening treatment is performed on at least a plastic working portion surface of the punch and die.

  According to the precision plastic processing apparatus of claim 10, at least the surface of the plastic processing portion of the punch and die is formed with a fine and dense structure with high toughness on the surface by WPC processing or shot peening processing, and the hardness is increased. . At the same time, by changing to fine dimples, the friction and wear characteristics as the surface properties of the movable jig and the fixed jig are improved, and the dimples become an oil reservoir for lubricating oil and improve the lubricating action.

  According to the precision plastic working method and the precision plastic working apparatus of the present invention, it is possible to achieve a precision plastic working equivalent to or better than the fine blanking with an inexpensive general-purpose press without using an expensive fine blanking press. It is.

  Therefore, according to the precision plastic processing method and the precision plastic processing apparatus of the present invention, for example, when punching a workpiece with a punch (movable jig) as plastic processing, the indentation protrusion is press-fitted into the workpiece in the primary press-fitting and processing steps. As a result, while the workpiece material is about to spread in a direction perpendicular to the punching direction (horizontal direction), the plastic working process of the workpiece is started by the cutting edge portion of the punch. When the blade edge of the punch reaches the depth of the indentation protrusion in the primary press-fitting / machining process, the second press-in operation of the indentation protrusion is started, so that the plastic work part is In addition, since further work material is stably supplied, further fluidization of the material in the plastic working portion is smoothly performed, and at the same time, compressive stress is applied to the work. Therefore, even if the precision plastic working apparatus is made high cycle, a beautiful shear surface is obtained without causing a fracture surface due to insufficient material in the plastic working portion, and the dimensional accuracy of the product is improved. In addition, by increasing the precision plastic processing equipment to a high cycle, productivity can be improved, and without using an expensive fine blanking press device, an inexpensive general-purpose press device is equivalent to or better than fine blanking processing. Precision shearing can be achieved.

It is sectional drawing which shows Example 1 of the state which assembled | attached the precision plastic processing apparatus of this invention to the general purpose press apparatus. It is sectional drawing which shows the punch part in a secondary press-fit and a manufacturing process same as the above. It is an expanded sectional view of the punch part in a punching completion process same as the above. FIG. 4A is a cross-sectional view showing the punching operation of the punch, FIG. 4A shows the punching operation before the punching operation, and FIG. 4B shows the contact point of the pushing protrusion with the workpiece surface. FIG. 5A is a cross-sectional view showing a punching operation, FIG. 5A shows a point of contact with the workpiece surface, and FIG. 5B shows a primary press-fitting / machining end process. FIG. 6 is a cross-sectional view showing the punching operation of the punch, FIG. 6A shows the secondary press-fitting / processing step, and FIG. 6B shows the end step of the punching operation. It is explanatory drawing which shows the timing of operation | movement of a punch, a stripper plate, and a knockout punch same as the above. It is the perspective view which showed a part of workpiece | work which shows the state after a product was punched out as the cross section same as the above. FIG. 9 is a cross-sectional view of a precision plastic working apparatus showing a punch punching operation in Embodiment 2 of the present invention, and FIG. 9 (a) is before the punch punching operation, and FIG. FIG. 9C shows the secondary press-fitting / processing step of the pushing protrusion. It is a lubricating oil circulation circuit diagram in the precision plastic working apparatus of the present invention.

  Embodiments as the best mode for carrying out the present invention will be described below with reference to the drawings. Of course, it goes without saying that the present invention can be easily applied to other than those described in the embodiments without departing from the spirit of the invention. In the present embodiment, a punching process in which a workpiece is punched with a punch to form a product will be described as an example of precision plastic processing.

  FIG. 1 shows a state in which a precision plastic working device of the present invention is assembled to a conventionally known general-purpose press device (the press device itself is not directly related to the present invention, so the whole is not shown). It is. The precision plastic working apparatus of the present invention, indicated as a whole by 1, comprises an upper mold 10 and a lower mold 50 that can move toward and away from each other in the vertical direction. The upper die 10 is provided with a plurality of fixing bolts 19 with respect to the upper die base plate 13 driven by a driving means of a general-purpose press device (which may be mechanical or hydraulic as long as a high cycle is realized). It is attached. The upper die 10 includes an upper die set 12 that fixes the punch 11 as a movable jig, a pressure member 15 that transmits a driving force to the punch 11, a stripper plate 20 that controls fluidity of the material during plastic processing, and the stripper plate. A hydraulic piston 17 or the like as 20 press-fitting driving force transmission means is provided. The lower mold 50 is attached to the lower mold base plate 53 of the general-purpose press device. The lower mold 50 includes a die 51 as a fixing jig, a lower die set 52 for fixing the die 51, and the like.

  As a result, a work W such as a steel plate (generally a belt-shaped material and presents a belt-shaped body whose longitudinal direction is the vertical direction in the drawing of FIG. 1) is placed on the die 51, and a general-purpose press device is mounted. The driving force is transmitted to the punch 11 via the upper die base plate 13, the pressure member 15 and the like, and the punch 11 is lowered to punch the product S from the workpiece W (see FIG. 6B). 6 is used for explaining the present invention, but the overview is the same as that of the conventional workpiece W and product S). The punching structure and process up to here are conventionally known.

  The upper die 10 has a shape that is the same as the shape of the product S to be punched and has a generally columnar body (generally a prismatic shape in the illustrated embodiment) that drives the punch 11 in synchronization with the drive cycle of the general-purpose press device. It has a force transmission structure. The die 51 has a punching hole 51a having the same shape as that of the product S to be punched in the center. In the punching hole 51a of the die 51, a knockout punch 58 that also serves as a product ejector is incorporated in a vertically movable manner to support the product S to be punched at the time of punching and to discharge the punched product S after the punching is completed. ing. The knockout punch 58 is driven by appropriate driving means such as a hydraulic cylinder 59, and at the time of punching, a predetermined hydraulic pressure is supplied into the hydraulic cylinder 59 via a hydraulic line 55 by a hydraulic pump 54. Supports the product S to be punched against the punching driving force of the punch 11, and has a function of driving the hydraulic cylinder 59 and discharging the product S punched by the punch 11 outside the general-purpose press device after punching is completed. .

  A stripper plate 20 is disposed between the die 51 and the upper die set 12, and an insertion hole 16 that allows relative sliding movement with the punch 11 is formed in the stripper plate 20. A guide shaft 21 connected to the stripper plate 20 is guided to the upper die set 12 so as to freely move up and down, and the stripper plate 20 is suspended and fixed to the guide shaft 21 (the state of FIG. On the other hand, the lower limit state of the stripper plate 20 is shown).

  An annular push-out projection 23 is formed on the periphery of the back surface side (lower side in FIG. 1) of the insertion hole 16 of the stripper plate 20 so as to surround the vicinity of the outside of the punching hole 51a of the die 51. As shown in FIGS. 4 to 6, the pushing protrusion 23 of the stripper plate 20 forms a knife-edge-shaped V-shape with a sharp tip, and its inner inclined surface 23 a is in contact with the inner peripheral surface of the insertion hole 16. It is integrally formed without providing a step portion so as to form a continuous surface. The upper die set 12 incorporates a hydraulic piston 17 as press-fitting drive means for pressing and pressing the stripper plate 20 against the workpiece W at a predetermined pressure during punching with the punch 11. The front end (lower end in FIG. 1) of the pushing protrusion 23 of the stripper plate 20 is disposed so as to contact the workpiece W surface slightly ahead of the front end (lower end in FIG. 1) of the punch 11. As a result, the pushing protrusion 23 of the stripper plate 20 contacts the workpiece W surface before the punch 11 contacts the product S, and the workpiece W is moved to the die 51 by the hydraulic piston 17 in the hydraulic cylinder 18 maintaining a predetermined pressure. On the other hand, pressure is applied, and the pushing protrusion 23 formed at the tip of the stripper plate 20 is pushed into the workpiece W, thereby improving the fluidity of the material of the workpiece W and supplying the material to the plastic processing portion of the punch 11.

  Also in general fine blanking processing, it is known that the indentation protrusion 23 bites into the workpiece W during plastic processing. In the present invention, in the first stage of plastic working (primary press-fitting / machining process), the pressing protrusion 23 is press-fitted into the work W by the hydraulic pressure in the hydraulic cylinder 18, so that the material near the plastic working surface of the work W is obtained. In the intermediate stage (secondary press-fitting / working process) in which plastic working is in progress, the processed surface is further pressed into the work W by further press-fitting into the workpiece W. In the intermediate processing stage (secondary press-fitting / processing step), which may cause fine fractures, plasticity processing is executed by increasing the fluidity of the material. Thus, as a result of the further press-fitting operation of the pushing projection 23 into the workpiece W in the intermediate stage of plastic working following the press-fitting of the pushing projection 23 into the workpiece W in the initial stage of plastic working, the remaining work W In FIG. 8, a deeper groove portion 24 having a V-shaped cross section surrounding the periphery of the punch 11 along the shape of the punched product S is left (FIG. 8).

  Further explanation will be given. FIG. 1 shows a state in which the general-purpose press apparatus is at the upper limit position, and the precision plastic working apparatus of the present invention is assembled to the general-purpose press apparatus, and shows a state in which the upper die base plate 13 is raised from the press working step. . As described above, the upper die set 12 is fixed to the upper die base plate 13, and the punch 11 is fixed to the upper die set 12. As a result, the punch 11 periodically descends and rises in synchronization with the driving force of the general-purpose press device. The stripper plate 20 is suspended and fixed to the upper die set 12 by a guide shaft 21. A downward force is always applied to the stripper plate 20 via a piston pin 26 by a hydraulic piston 17 in a hydraulic cylinder 18 maintaining a predetermined pressure. The stripper plate 20 shown in FIG. 1 is in a lower limit position with respect to the punch 11. An engaging ring 25 having a predetermined thickness is provided between the upper die set 12 and the stripper plate 20. This engagement ring 25 is attached to the upper die set 12 side by an appropriate means, and in a process other than the machining process of the general-purpose press device, the stripper plate 20 is suspended from the guide shaft 21 and is at the lower limit position. A gap of a distance L (FIG. 1) between the lower end surface of the engagement ring 25 and the upper end surface of the stripper plate 20 is formed (this distance L will be described later).

  In order to effectively realize the precision plastic working apparatus of the present embodiment, although it is not directly related to the present invention, it is important to consider lubrication on the work surface. When pressing a 6mm thick plate at high cycle, lubrication oil with low kinematic viscosity will cause the die to run out while the mold bites into the work material, causing a reduction in mold life. Oil with a kinematic viscosity of 100 cSt (centistokes) or more is used. In addition, when pressing a 6mm thick plate with a high cycle, if the amount of lubricant supplied is small, the lubricant will run out, and if the amount supplied is large, oil film marks will be formed on the product, so that the amount of lubricant supplied can be controlled appropriately. There is a need to do.

  In high cycle molding, a product molded with a higher plastic deformation resistance than that of normal speed pressing is about 80 ° C. to 100 ° C., and the temperature of the mold rises due to this heat. Since the temperature rise of the mold causes a decrease in the mold life, the temperature of the lubricating oil is adjusted to about 10 ° C. ± 1 ° C., and it is passed through the mold and simultaneously supplied to the cutting edge. The temperature is controlled. The supply pump at that time uses a high kinematic viscosity lubricating oil of 100 cSt (40 ° C.) or higher at 10 ° C., and passes a plurality of 1.5 mmφ so that the lubricating oil is evenly distributed to the cutting edge through the inside of the mold. Since a pressure loss becomes high by being discharged from the discharge port, a high output supply pump is used. Further, the amount of lubricating oil supplied is controlled in order to optimize the amount of lubricating oil supplied.

  When the press working is performed at a high cycle, the lubricating oil runs out between the mold and the material to be processed due to the high cycle and the material to be processed being a thick plate, which causes the mold to be damaged. In order to prevent this, the lubricating oil is forcibly supplied from the inside of the mold through the lubricating oil supply hole to the machined portion to improve the mold life. As the lubricating oil, a lubricating oil having a high kinematic viscosity is used. In high cycle press processing, since plastic processing is performed at high speed, high processing heat is generated due to processing resistance of the material to be processed, and the mold also becomes high temperature, resulting in a decrease in product accuracy and damage to the mold. Therefore, by passing the lubricating oil into the mold, the mold temperature can be controlled and the mold life can be improved. The forced lubricating oil device can control the amount of lubricating oil supplied. Lubricating oil temperature control is also possible. Lubricating oil is supplied from the tank to the inside of the mold through a pipe by an electric pump. In order to use lubricating oil with high kinematic clay at a temperature controlled to 10 to 15 ° C., a large electric pump is adopted. Lubricating oil supplied to the inside of the mold is collected in the lower part of the mold except for the amount necessary for lubrication, and is collected and reused in the tank through the dust filter.

  In the precision plastic working apparatus using the general-purpose press apparatus of this embodiment, a forced lubrication structure is employed. In general lubrication, lubricating oil is applied to the upper and lower surfaces of the coil material. In this embodiment, the lubricating oil is discharged from the inside of the mold (upper die: inside the punch, lower die: inside the knockout) and the cutting blade. A configuration is realized in which the gap between the tip and the material to be processed is filled with the lubricating oil so that the lubricating oil does not run out. As a result, the upper die always has a punch and stripper, and the lower die has a gap between the die and the knockout so that an oil film is always formed by the lubricating oil, and no galling is caused by sliding the mold.

  The forced lubricating oil system of the present embodiment includes a lubricating oil tank, a large lubricating oil supply pump, a supply amount adjusting valve, a lubricating oil temperature control mechanism, and a lubricating oil recovery mechanism. Lubricating oil is temperature-controlled in the tank and is sent to the mold by a supply pump through a supply amount control valve. The excess lubricating oil used in the mold is recovered by the recovery mechanism and returns to the lubricating oil tank through the filter.

  In the present embodiment, a lubricating oil circulation system is incorporated in order to realize the precision plastic working apparatus 1. The lubricating oil circulation system will be described with reference to FIG. In FIG. 10, reference numeral 30 denotes a new lubricating oil supply tank, 31 denotes an oil storage tank that stores the lubricating oil supplied from the oil supply tank 30 via a filter 42, and 32 denotes lubricating oil in the oil storage tank 31 via a filter 43. A circulation pump for sucking and discharging to the precision plastic processing device 1 side, 33 is a cooling device for cooling the lubricating oil supplied from the circulation pump 32, and 34 is a precision adjusting the pressure of the lubricating oil supplied from the cooling device 33. It is a hydraulic pressure adjusting mechanism supplied to the plastic working apparatus 1 side. The lubricating oil supplied to the precision plastic processing apparatus 1 from the discharge port 35 of the hydraulic pressure adjusting mechanism 34 is cooled to about 10 ° C. by the cooling device 33, and the lubricating oil returned from the precision plastic processing apparatus 1 is returned from the oil return port 36. It returns to the oil tank 31 through the filter 42 and circulates again. The cooling device 33 that cools the lubricating oil compresses the refrigerant with the compressor 37, cools it with the condensers (condensers) 38 and 39, condenses it, decompresses it with the expansion valve 40, and vaporizes the refrigerant with the cooler 41. A conventionally known refrigeration cycle is achieved by cooling. The lubricating oil cooled by the cooling device 33 is adjusted to a temperature of 10 ° C. ± 1 ° C. and supplied to the shearing portion from the inside of the punch 11 and die 51 of the precision plastic working device 1 and utilized for cooling and lubrication.

  A specific configuration for lubricating the shearing portion from the inside of the punch 11 and the die 51 of the precision plastic processing apparatus 1 will be described. As shown in FIG. 3, the punch 11 has a central flow passage 11b for lubricating oil formed therein, and a branch flow passage 11c branched from the central flow passage 11b in the vicinity of the cutting edge portion 11a at the lower end of the punch 11. Is formed. Therefore, the lubricating oil cooled by the cooling device 33 is discharged from the flow passage 11b in the punch 11 toward the vicinity of the blade edge portion 11a of the punch 11 through the branch flow passage 11c. On the other hand, a lubricating oil central flow passage 58b is also formed inside the knockout punch 58 toward the tip of the knockout punch 58, and a branch flow passage 58c branched from the central flow passage 58b is formed near the upper end of the knockout punch 58. Is formed. When the lubricating oil is discharged from the branch flow passage 58c via the central flow passage 58b, the lubricating oil is discharged to the inner peripheral surface of the punching hole 51a in the vicinity of the tip end portion of the knockout punch 58. The cooled lubricating oil is supplied from the punch 58, and an oil film is always formed by the lubricating oil in the gap between the punch 11, the knockout punch 58 and the workpiece W, or the gap between the workpiece W and the punching hole 51a. Lubricating oil supplied from the inside of the punch 11 and the knockout punch 58 flows onto the lower base plate 53 from the gap between the lower die set 52 and the die 51 and the gap between the die 51 and the workpiece W, and the lower base plate 53. The oil is recovered from the oil recovery groove 60 provided at the peripheral edge of the oil to the oil return port 36 and is returned to the oil supply tank 31 and circulated again. As the lubricating oil used in the precision plastic working apparatus 1 of the present embodiment, it is preferable to use a lubricating oil having a high kinematic viscosity and a low temperature, and specifically, a kinematic viscosity having a viscosity of 100 cSt or more was used.

  However, in a general press method, it is a very severe plastic working method to perform a precision shearing with a high cycle that can obtain a high-functional product surface. A highly functional product surface cannot be obtained unless the surface properties of the inner surface of the mold, particularly the blank die, are maintained within a certain value. Even in the mold structure, a mold structure that can freely flow the work material is required for plastic deformation at a high cycle. The present invention relates to a mold structure capable of freely flowing such a processed material. However, the present invention does not stop there, and forcibly flowing a material to be processed inside the mold is not limited to the mold. On the other hand, in order to increase the load, it is necessary to devise measures to reduce it. This is because, because of the high cycle processing, since the plastic deformation resistance is large and the processing speed is high, the calorific value is increased, and the mold is subjected to a load higher than usual, resulting in mold wear. Therefore, it has been found that mold surface control of a coating film or the like is a very effective method as means for controlling heat generation and reducing frictional resistance of the mold. However, in that case, there are many demands for film strength, slipperiness, adhesion and the like, which are future development issues. As a basic experiment of the present invention, a matching test between a mold material and a coating film was performed. However, there was a coating process suitable for each mold material, and it was difficult to generally evaluate only the coating.

  As the mold configuration, the entire mold is supported by a hydraulic cushion plate, and the generation source, control, and supply of the hydraulic pressure are configured by a forced lubricating oil system using a dedicated hydraulic pressure generator. This achieves work material flow control by the hydraulic cushion plate. That is, the hydraulic cushion plates installed above and below the mold apply a maximum pressure of 30 t to the stripper and knockout in the mold to control the flow of the work material. The pressure can be variable, and it can be locked by applying normal pressure.

  In addition, it is preferable to perform coating as a surface modification of the punch and die. In this way, the punch and die are subjected to ceramic coating treatment, which prevents the generation of abnormal products and improves the surface roughness of the coating film that is produced, thereby preventing the adhesion of the work material and the gold caused by the adhesion. Mold wear can be reduced. As the surface modification of the punch and die, processing known as shot peening or WPC (Wide Peening and Cleaning) processing is performed. The punch die has a high hardness by forming a fine and tough dense structure on the surface by this WPC treatment. At the same time, the frictional wear characteristics as the surface properties of the punch and die are improved by changing to fine dimples. The dimples serve as a reservoir for lubricating oil and improve the lubricating action.

  By performing the WPC process after the coating process, it is possible to generate a strong layer on the mold surface by the synergistic effect of the coating and WPC, and to improve the mold life. Further examination is required for the coating processing conditions and WPC processing conditions.

  In the precision plastic working apparatus of this embodiment, a die insert type is adopted, and the die is composed of two parts, an insert part and a case part. The insert part has an outer periphery and the case part has an inner periphery that is tapered. When assembled, the insert part is subjected to compressive stress like a fine blanking shrink ring. In this way, by making an insert, the newly manufactured part can be reduced in size and the cost can be reduced.

  Next, with reference mainly to FIG. 4 thru | or FIG. 7, operation | movement in the Example of the precision plastic working apparatus 1 of this invention is demonstrated. 4 to 6 are diagrams showing the relative positional relationship between the punch 11, the stripper plate 20, and the knockout punch 58 in the vicinity of the processing portion according to the progress of the processing step, and FIG. 7 shows the punch 11 according to the progress of the processing step. FIG. 6 is a stroke transition diagram of the stripper plate 20 and the knockout punch 58. In the stroke transition diagram of FIG. 7, the movement of each jig is displayed linearly for easy understanding. However, when incorporated in an actual apparatus, each of them has a curve shape close to a sine curve. It is something that moves.

(Start position t1)
4A shows the state at time (t1) in FIG. 7, the punch 11 and the stripper plate 20 are at the upper limit position, the knockout punch 58 is at the upper limit position, and the workpiece W is placed on the die 51. The upper mold base plate 13 is lowered by the drive means (not shown) of the general-purpose press device. From this start position, the upper die set 12 descends, and the punch 11 fixed to the upper die set 12 and the stripper plate 20 suspended from the upper die set 12 start to descend synchronously. At this time, the tip of the knockout punch 58 at the upper limit position is configured to maintain the same surface as the upper surface of the die 51, or is configured to maintain a substantially flush surface although it protrudes slightly. In the present embodiment, the tip of the punch 11 is positioned amm above the tip of the push-in protrusion 23 of the stripper plate 20 (a position retracted with respect to the machining stroke). The positional relationship between the tip of the punch 11 and the tip of the push-in protrusion 23 can be selected as appropriate depending on the properties of the workpiece material. For example, the front end portion of the punch 11 and the front end portion of the pushing protrusion 23 may be flush with each other, or the front end portion of the punch 11 may be slightly ahead of the front end portion of the pushing protrusion 23 in some cases.

(Indentation contact → primary press-fitting / machining process)
Next, when the upper die set 12 is lowered together with the upper die base plate 13 from the state of the timing t1 in FIG. 4A by the driving means of the general-purpose press device, the pushing protrusion 23 of the stripper plate 20 amm ahead of the punch 11 is formed. It contacts the workpiece W at the timing t2 in FIG. In this state, the stripper plate 20 is backed up by the hydraulic piston 17 as the press-fit driving force transmitting means via the piston pin 26 as described above. As a result, the hydraulic piston 17 is retracted while the entire upper die base plate 13 is lowered by the driving means of the general-purpose press device, and the pushing protrusion 23 of the stripper plate 20 is press-fitted into the workpiece W. The press-fitting operation of the push-in projection 23 during this time is performed by controlling the hydraulic pressure of the hydraulic cylinder 18 to be pressurized (in this embodiment, the predetermined pressure is maintained, but depending on the material of the workpiece W, the backup hydraulic pressure is controlled by the lowering stroke. And may stop in a state where the hydraulic pressure of the hydraulic cylinder 18 and the resistance force of the workpiece W are balanced (state at timing t3 in FIG. 5A). As a result, a groove portion 24 having a V-shaped cross section is formed on the workpiece W so as to surround the cutting edge portion 11a of the punch 11 by the pushing projection 23, and the material of the cross-sectional V-shaped groove portion 24 improves the fluidity and supplies the processed portion. (Primary press-fitting and processing step). This state is a state at timing t4 in FIG. 5B, and shows a state where the tip of the punch 11 exactly coincides with the stroke position of the tip of the pushing projection 23 of the stripper plate 20. In the present embodiment, the workpiece W to be precisely plastic-formed is JIS G3131 SPHC (yield point 216N, tensile strength 350N / mm ² ), the plate thickness is set to 6 mm, for example, and the stripper plate is used as the workpiece W. The primary press-fitting amount L (the press-fitting amount in a state where the hydraulic pressure of the hydraulic cylinder 18 and the resistance force of the work W are balanced and the press-fitting operation of the push-in projection 23 is stopped) that bites the 20 push-in projections 23 is approximately 0.9 mm. The hydraulic pressure of the hydraulic cylinder 18 is set so that In this embodiment, the hydraulic pressure of the hydraulic cylinder 18 is controlled to maintain a predetermined pressure, and the press-fitting speed of the push-in protrusion 23 is press-fitted at a constant speed in synchronization with the descending speed of the punch 11 (see FIG. 7). The press-fitting speed can also be controlled by controlling the hydraulic pressure of the hydraulic cylinder 18 according to the material of the workpiece W.

(Secondary press-fitting and processing process)
Thus, in the final press-fitting / working process end state (the state from FIG. 5 (A) to FIG. 6 (A)) in which the press-fitting of the pushing projection 23 of the stripper plate 20 into the work W is stopped, the hydraulic cylinder 18 Therefore, the press-fitting 23 does not press-fit into the work W. The upper surface of the stripper plate 20 contacts the lower surface of the engagement ring 25 during the period from the state at timing t3 in FIG. 5A to the state at timing t5 in FIG. In this embodiment, the two are in contact with each other in the state of timing t5 in FIG. 6A, but this timing may be any timing, but after both contact, the drive means of the general-purpose press device. It is necessary to determine various dimensional relationships in consideration of the fact that when the upper die set 12 is lowered, the pushing protrusion 23 of the stripper plate 20 is lowered in synchronization with the punch 11.

  That is, the cutting edge portion 11a of the punch 11 comes into contact with the workpiece W at the timing t3 in FIG. 5, and further, the punch 11 is lowered so that the cutting edge portion 11a of the punch 11 and the inner peripheral edge of the punching hole 51a of the die 51 The shearing operation of W (primary press-fitting / processing step) is achieved (timing t3 in FIG. 5A → timing t5 in FIG. 6A). At the time of this shearing operation (primary press-fitting / processing step), the stripper plate 20 stands by in a stopped state, and the primary of the pushing protrusion 23 after the punch 11 comes into contact with the workpiece W as shown in FIG. It is press-fitted by a pressurizing amount L (0.9 mm).

  Next, at the timing t5 in FIG. 6A, the upper die is reached when the blade edge portion 11a of the punch 11 reaches the position of the depth L1 of approximately 3 mm beyond the position of the pushing protrusion 23 in the stopped state (primary pressurization amount L). The engagement ring 25 fixed to the set 12 comes into contact with the stripper plate 20 waiting in a stopped state. As a result, the punch 11 and the stripper plate 20 are integrally lowered by the operation of the driving means of the general-purpose press device, and the workpiece W is punched by the punch 11 in the process shown in FIG. 6 (A) → FIG. 6 (B). In conjunction with the operation, the pushing protrusion 23 of the stripper plate 20 further bites into the workpiece W (secondary press-fitting / machining process), and improves the fluidity of the material and at the same time achieves punching with the workpiece W subjected to compressive stress. it can. In the present embodiment, the product S is punched out by the die 51 when the cutting edge 11 a of the punch 11 preceding the pushing protrusion 23 descends beyond the lower surface of the plate thickness (6 mm) of the workpiece W. In the present embodiment, the knockout punch 58 stands by at the bottom dead center by closing the hydraulic line 55 for supplying hydraulic pressure to the knockout punch 58 at the timing t6 in FIG.

  In the present invention, when the workpiece W is punched with the punch 11 as described above, in the primary press-fitting / machining process, the pushing protrusion 23 is bitten into the workpiece W by a predetermined amount, so that the workpiece W is in the machining direction. In addition, while compressing the workpiece W by pressing the stress that spreads in the vertical direction (horizontal direction in the figure) by the pressing projection 23, the workpiece W is also subjected to compressive stress and fluidity to the processed portion of the material is increased. The shearing motion of the workpiece W can be achieved. Further, from this state, when the cutting edge 11a of the punch 11 is lowered by a predetermined amount (L1) beyond the biting amount (L) of the pushing protrusion 23 in the primary press-fitting and processing step in the shearing operation of the punch 11, the punch 11 The punch 11 and the push-in protrusion 23 are lowered in synchronization with the stripper plate 20 (secondary press-fitting / machining process), and the push-in protrusion 23 further lowers the punch 11 while biting into the workpiece W.

  At this time, the knockout punch 58 descends in synchronism with the punch 11 from the timing t3 in FIG. 5 while sandwiching the workpiece W with the punch 11 (timing t3 to timing t6). When the workpiece W is punched by the punch 11, the product S is placed on the knockout punch 58 that stands by in a state where the product S is stopped at the bottom dead center, and the punch 11 rises at the timing t <b> 7 and moves to the knockout punch 58. When the hydraulic line 55 is opened and a predetermined hydraulic pressure is supplied into the hydraulic cylinder 59, the product S rises together with the knockout punch 58, and is unloaded from the unloading chute by an unillustrated unloading mechanism. Thereafter, the product S is punched in the same cycle.

  In this embodiment, the shape of the indentation projection 23 of the stripper plate 20 is important. When plastic processing is performed at a high cycle, the material to be processed can be freely used in the V-ring shape for normal fine blanking. A dedicated V-shape is set to prevent flow control. In this embodiment, a double action mechanism using an engagement ring is adopted. That is, as the mold is lowered by the engagement ring in the mold, the pushing protrusion 23 of the stripper plate 20 that is V-shaped processing the work material at a fixed position is lowered again to assist the flow of the work material. However, the mechanism does not generate a fracture surface due to a material shortage even in a high cycle.

  As described above, in this embodiment, when the workpiece W is punched out with the punch 11, the pushing protrusion 23 of the stripper plate 20 is bitten into the workpiece W by a predetermined amount in the primary press-fitting / processing step, so that it is perpendicular to the processing direction. The punching process of the workpiece W by the cutting edge portion 11a of the punch 11 is achieved while the pressing protrusion 23 presses the stress that spreads in the direction (horizontal direction), and the cutting edge portion 11a of the punch 11 performs primary pressurization. When the amount L exceeds the amount L and reaches a predetermined amount (3 mm), the punch 11 and the stripper plate 20 are lowered synchronously to achieve the secondary press-fitting operation of the pushing projection 23. As a result, the pushing projection 23 is pressed into the workpiece W again while punching the workpiece W with the punch 11, and the pushing of the pushing projection 23 smoothes the fluidization of the material in the sheared portion of the workpiece W and compresses the workpiece W with compressive stress. Can be added.

  As a result, even in the primary press-fitting / machining process, the material is insufficient even if the punch 11 is speeded up in order to improve the fluidity of the material to the machined part and at the same time perform the punching process with a compressive stress applied to the workpiece W. A beautiful shearing surface can be obtained without generating a fracture surface due to, the dimensional accuracy of the product S can be improved, and the precision plastic processing apparatus 1 can be cycled up to about 100 strokes / min. Can be improved. In such a precision plastic working apparatus 1 of the present embodiment, a precision shearing process equivalent to or better than the fine blanking process can be achieved with an inexpensive general-purpose press apparatus without using an expensive fine blanking press apparatus. Can do. In other words, the stripper plate 20 is backed up against the workpiece W by the hydraulic cylinder 18 in the primary press-fitting / processing step, and the stripper plate 20 is lowered in synchronization with the punch 11 in the secondary press-fitting / processing step. In this way, the engagement ring 25 is provided in a simple configuration.

  Further, in the primary press-fitting / processing step of the push-in protrusion 23, the depth L at which the push-in protrusion 23 is press-fitted into the workpiece W can be easily adjusted by changing the hydraulic pressure of the hydraulic cylinder 18 that presses the stripper plate 20. Furthermore, the positional relationship between the insertion hole 16 in which the punch 11 is slidably fitted to the stripper plate 20 and the pressing protrusion 23 formed on the outer side thereof is such that the inner inclined surface 23 a of the pressing protrusion 23 is between the insertion hole 16. 4 to 6, the cross-section by the pushing protrusion 23 is formed in the vicinity of the peripheral edge of the opening W1 of the workpiece W punched out by the punch 11 as shown in FIGS. A V-shaped groove 24 is formed. This makes it possible to reduce the distance between the area of the groove 24 where the material is sent out by the press-fitting push-in projection 23 and the portion where the punching process proceeds by the punch 11. This also increases the effect of generating static pressure in the vertical direction by the push-in protrusion 23 during the primary press-fitting / machining process, and in addition, fluidization of the material by the push-in protrusion 23 also occurs during the secondary press-fitting / working process. It is done more smoothly.

  FIG. 9 shows a second embodiment of the present invention, where parts having the same functions as those of the first embodiment are denoted by the same reference numerals, description of overlapping parts is omitted, and only different parts will be described.

  In the first embodiment, the engagement ring 25 is fixed to the upper die set 12 and the engagement ring 25 is brought into contact with the stripper plate 20 as a timing for starting the secondary press-fitting / machining process of the pushing protrusion 23. As shown, in the second embodiment, the secondary press-fitting / working process of the push-in protrusion 23 is started / executed by the cam mechanism. On the other hand, in the second embodiment, a support 63 is fixed to a lower die set 52 of a press device (the whole is not shown), and a horizontal direction with respect to the support 63 (direction perpendicular to the processing direction of the punch 11). ) Slide slide 60 is provided. The stripper plate 20 is driven by fixing the drive cam 61 to the upper die set 12 that drives the punch 11, and fixing the engagement cam 62 to the upper surface side of the stripper plate 20, and driving by lowering the upper die set 12. This is achieved by a cam mechanism in which the slide cam 60 is slid by the driven cam 61 and the force is transmitted to the engagement cam 62 by the sliding movement of the slide cam 60.

  On the left and right sides of the slide cam 60, slide cam surfaces 60a and 60b having the same inclination (in this embodiment, the slide cam surface 60a and the slide cam surface 60b are linear and have the same inclination, but the desired motion The shape of the cam surface can be changed as appropriate to give the stripper plate 20 to the stripper plate 20), and the drive cam 61 and the engagement cam 62 are respectively associated with the slide cam surfaces 60a and 60b. A driving cam surface 61a and an engaging cam surface 62b are formed. In addition, a spring 64 that urges the slide cam 60 in a direction in which the slide cam 60 is engaged with the drive cam 61 is incorporated in the column 63 that fixes the slide cam 60.

  In the present embodiment configured as described above, when the upper die set 12 is lowered by the driving means of the general-purpose press device, the punch 11 fixed to the upper die set 12 and the hydraulic cylinder 18 are the same as in the first embodiment. The stripper plate 20 backed up by the upper die set 12 is lowered, and the pushing protrusion 23 of the stripper plate 20 preceding the punch 11 comes into contact with the workpiece W. The state of the processed portion shifts from the state of FIG. 4 (a) t1 to the state of FIG. 4 (b) t2, but the drive cam 61, the slide cam 60, and the engagement cam 62 are not in the engaged state. However, the state of the general-purpose press device in FIG. 9A shows a state in which the upper die set 12 is retracted in order to facilitate understanding of the device configuration.

  Further, when the upper die set 12 is lowered by the driving means of the general-purpose press device, the stripper plate 20 is pressed, and the pushing protrusion 23 is moved to the workpiece W as shown in FIGS. 5 (a) and 5 (b). The stripper plate 20 stops in a state where it has bitten to 9 mm (primary joining / processing step). As described above, the primary press-fitting / working process in the second embodiment is achieved with substantially the same configuration as in the first embodiment. That is, the stripper plate 20 is backed up by the hydraulic cylinder 18 maintained at a predetermined pressure via the piston pin 26, and the pushing protrusion 23 formed on the stripper plate 20 is moved to a predetermined position in the workpiece W by the progress of processing. Press fit until (L). In this state, the drive cam 61 and the slide cam 60 are engaged, and the slide cam 60 slightly slides in the right direction in FIG. 9, but the slide cam 60 and the engagement cam 62 are not yet engaged. A pressure input by the pressing force of the hydraulic cylinder 18 acts on the workpiece W on the stripper plate 20. In this state, the general-purpose press device is in the state shown in FIG.

  When the upper die set 12 is further lowered from this state, the engagement between the drive cam surface 60a of the drive cam 61 attached to the upper die set 12 and the slide cam surface 60a of the slide cam 60 further proceeds, and the lowering operation of the punch 11 is performed. In conjunction with this, the slide cam 60 slides further toward the die 51 side, and the cutting edge 11a of the punch 11 exceeds the primary press-fitting amount of the push-in protrusion 23 and reaches a depth of about 3 mm of the workpiece W (see FIG. 6A). State), the slide cam surface 60 b of the slide cam 60 engages with the engagement cam surface 62 b of the engagement cam 62 attached to the stripper plate 20. As a result, the stripper plate 20 is integrally lowered in conjunction with the lowering operation of the punch 11 by the driving means of the general-purpose press device, and the pushing protrusion 23 is punched while punching the workpiece W with the punch 11 as shown in FIG. The secondary press-fitting operation for press-fitting into the workpiece W is started (state after FIG. 6A). By the secondary press-fitting / working process of the pushing protrusion 23, the fluidity of the work material can be improved and a compressive stress can be applied to the work W, and the work material can be stably supplied to the sheared portion of the work W. For this reason, as in the first embodiment, in the secondary press-fitting / working process, the material in the sheared portion can be smoothly fluidized, and at the same time, a compressive stress can be applied to the workpiece W, and the punch 11 can be sped up. In addition, a beautiful shear surface is obtained without causing a fracture surface due to lack of material, and the dimensional accuracy of the product S is improved.

  The cam mechanism using the slide cam 60, the drive cam 61, and the engagement cam 62 can achieve a secondary press-fitting / machining process adapted to the material of the workpiece W by changing the shape of each cam surface. is there. That is, by changing the inclination angle of each cam surface, it is possible to easily adjust the descending speed in the secondary press-fitting operation of the push-in projection 23 and the press-fitting amount that bites the work W. The cam surface shape is not limited to a straight line, and may be a curved surface. Furthermore, when the slide cam 60, the drive cam 61, or the engagement cam 62 is consumed, the cams 60 to 62 can be easily replaced, and the maintenance is excellent.

  As mentioned above, although each Example of this invention was explained in full detail, this invention is not limited to each said Example, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, the basic configuration of the precision plastic working apparatus 1 and the example in which a contact ring is provided in the first embodiment and the cam mechanism is provided in the second embodiment as an interlocking mechanism for starting the secondary press-fitting / working process of the push-in protrusion 23 are shown. However, for example, a hydraulic cylinder that drives the stripper plate may be provided separately from the drive mechanism of the general-purpose press device that drives the punch 11, and each drive means may be controlled individually. Further, although the punching has been described as an example of the plastic working, the present invention can be applied to a so-called half punching process in which a step recess is formed in the work by punching in addition to punching the work W by the punch 11. Further, the depth of the groove in the primary press-fitting / working process of the push-in protrusion 23, the depth of the punch 11 that is the timing for starting the secondary press-in process, or the shape of the push-in protrusion 23 may be selected as appropriate.

1 Precision plastic processing equipment 10,50 Mold 11 Punch (movable jig)
11a Cutting edge 15 Hydraulic cylinder (lifting drive means 16 Insertion hole 18 Hydraulic cylinder (press-fit drive means)
20 Stripper plate 23 Pushing projection 24 Groove 51 Die (fixing jig)
51a Punching hole 58 Knockout punch W Work S Product

Claims (11)

It is a plastic working method for obtaining a product by plastic working a workpiece with a movable jig and a fixed jig, and a sharp pushing protrusion is provided in the vicinity of the movable jig,
(A) Simultaneously improving the fluidity of the work material during plastic working by pressing the sharp pushing protrusion into the work prior to the movable jig as the movable jig descends. A primary press-fitting and machining process that applies compressive stress to the workpiece and processes it with a movable jig;
(B) By further driving the movable jig to further plastically process the workpiece by the movable jig, the movable jig is moved in a state preceding the sharp pushing protrusion. The secondary is processed by the movable jig by further pressing the indentation protrusion into the work in cooperation with the lowering movement of the tool to increase the fluidity of the work material during plastic working and at the same time applying compressive stress to the work A precision plastic processing method characterized by comprising a press-fitting and processing step. A punch, a die, a knockout punch arranged so as to be movable up and down relative to the die, and a stripper plate formed with a sharp indentation in the vicinity of the outside of the punch, the stripper plate and the die, In a plastic working method of punching a workpiece while sandwiching the workpiece with a punch and a knockout punch, a stripper plate having a sharp indentation protrusion formed near the outside of the punch is provided,
(A) Before pressing the punch into contact with the workpiece surface, the pressing projection of the stripper plate is press-fitted into the workpiece, and the pressing projection is pressed into the workpiece around the plastic working portion, and the workpiece material at the time of plastic working The primary press-fitting and machining process, which increases the fluidity of the workpiece and simultaneously applies a compressive stress to the workpiece and processes it with a punch,
(B) The plastic working of the workpiece is further advanced by further driving of the punch, and in the state where the punch precedes the pushing protrusion of the stripper plate, the punch is driven and moved together with the stripper. The press projection of the plate is further pushed into the workpiece to improve the fluidity of the workpiece material at the time of plastic working, and at the same time, it is provided with a secondary press-fitting and machining process in which a compressive stress is applied to the workpiece and machining is performed by a punch. Precision plastic working method. A plastic working method for obtaining a product by plastic working a workpiece with a movable jig and a fixed jig, wherein a sharp pushing protrusion is provided in the vicinity of the movable jig, and the plastic machining of the workpiece is performed,
A primary press-fitting / working process in which plastic working is performed while supplying the material to the plastic working part of the work by controlling the fluidity of the work material by press-fitting the indentation protrusions around the plastic working part of the work to a predetermined amount; and Precision plasticity characterized by a secondary press-fitting and machining process that performs plastic working while further supplying material to the plastic working part of the work by increasing the fluidity of the work material by further press-fitting the indentation protrusion Processing method.   4. The precision plasticity according to claim 1, wherein the further pushing operation of the pushing projection is operated in synchronization with the lowering operation of the movable jig or the punch. 5. Processing method.   A plastic working device that obtains a product by plastic working of a workpiece with a movable jig and a fixed jig, and has a sharp shape that press-fits into the vicinity of the product of the workpiece that is not applied to the product as the movable jig descends. The pushing protrusion is arranged in advance of the leading end of the movable jig, and the pushing protrusion is arranged before the movable jig contacts the workpiece surface. The fluidity of the workpiece material during plastic working is increased by press-fitting into the workpiece, and the pushing protrusion is moved to the movable jig while the workpiece is further plastically worked by the movable jig by further driving of the movable jig. A precision plastic working device characterized in that the device is further pushed in with the lowering motion of the tool.   A die for placing a workpiece, a stripper plate disposed opposite to the die, a punch slidably disposed on the stripper plate, a pushing protrusion provided on the lower surface side of the stripper plate, and the punch A knockout punch that is slidably disposed on the die opposite to the die, an elevating drive means that drives the punch up and down, and a press-fit drive means that press-fits the pushing protrusion into the workpiece, the press-fit drive means Is provided with a structure in which the pushing protrusion is press-fitted into the work before the punch contacts the work surface, and the lift driving means is in a state where the plastic processing of the work by the punch is further advanced by further driving of the punch. The precision is characterized in that it is configured to perform further pushing operation of the pushing projection in cooperation with the punching operation of the punch. Sex processing equipment.   7. The precision plastic working apparatus according to claim 5, wherein the further pushing operation of the pushing projection is operated by a cam mechanism in cooperation with a lowering operation of the movable jig or the punch. .   The further pressing operation of the pressing protrusion is configured to be operated in synchronization with the lowering operation of the movable jig or punch by an engagement ring having a predetermined thickness. The precision plastic processing device described.   The said stripper plate is provided with the insertion hole which slidably fits the said punch, and the said pushing protrusion is comprised by the surface where the inner side and the said insertion hole continued. Precision plastic processing equipment.   6. The precision plastic working apparatus according to claim 1, wherein a metal surface treatment such as a WPC treatment or a shot peening treatment is performed on at least a plastic working portion surface of the movable jig and the fixed jig. .   7. The precision plastic working apparatus according to claim 2, wherein a metal surface treatment such as a WPC treatment or a shot peening treatment is performed on at least a plastic working portion surface of the punch and die.

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