JP4866082B2 - Drilling method and drilling device for through-hole in work peripheral wall - Google Patents

Description

  The present invention relates to a method for drilling a through hole in a work peripheral wall in which a through hole is formed by press punching in a peripheral wall of the cylindrical part of a work having at least a part of the tubular part, a drilling device therefor, and a drilling device therefor The present invention relates to a work in which a through hole is opened by an installation method or a drilling device.

In order to open a through-hole in a workpiece, there are cutting with a drill, punching of a press, electric discharge machining, and the like. In the case where the workpiece has a cylindrical part such as a pipe in at least a part thereof, the above processing means can also be used to open a through hole in the peripheral wall of the cylindrical part.
However, in drilling with a drill or a press, burrs are generated at the hole edge, which takes time for deburring. In particular, when a through-hole is opened in the peripheral wall of the cylindrical portion, burrs are generated on the inner peripheral surface of the cylindrical portion when a drill is used or when punching is performed with a punch from the outside of the cylindrical portion. Some workpieces do not allow burrs inside the cylindrical part at all. However, when the workpiece is a small part, it is difficult to remove burrs generated inside the cylindrical portion in this way.
For this reason, conventionally, when the work is a small part having a cylindrical part and the peripheral wall is relatively thick, electric discharge machining has been employed to open a small through hole in the peripheral wall. However, electric discharge machining takes a long machining time, the productivity is poor, and the machining cost cannot be reduced.
Further, when a relatively large through-hole is opened even in a small part, a punch is punched from the outside of the cylindrical portion to open the through-hole, and later, the inner burr is manually removed. This also has poor productivity and cannot reduce the processing cost.

By the way, as shown in FIG. 22, about the board | plate material, the method of opening a through-hole without producing a burr | flash by punching a board | plate material (107b) is proposed (refer patent document 1).
In this process, a circumferential groove 174a corresponding to the hole diameter of the through hole 170a to be punched is formed on at least the back surface of the plate material (workpiece) (107b) by primary processing by pressing or cutting (FIG. 22A), and FIG. As shown in (2), the punching punch (151a) is driven into the position corresponding to the center of the circumferential groove from the opposite side surface of the plate (107b) by secondary processing by pressing to open the through hole (170a). Note that reference numeral 178a denotes scrap (removed waste).
However, the method of opening a through-hole in this plate material is simply applied by pressing the punch 151a against the die 151b from directly above, and is not applicable when the through-hole is formed in the peripheral wall of the cylindrical part of the small part. .
Therefore, in order to prevent the occurrence of burrs on the inner side of the work, it is conceivable to punch with a press die (punch) from the inner side of the cylindrical part. However, in this case, a small mold that can be inserted into the inside of the cylindrical portion is required, and there has been no drilling method and apparatus having a sufficient life and high productivity of the mold.
And also when drilling a through-hole in both the opposing parts in the surrounding wall of the cylindrical part of a workpiece | work, the suitable drilling method and its apparatus did not exist at all.
Japanese Patent Laid-Open No. 5-42330 ([0005], [0006], [0009], [0019], etc.)

A problem to be solved regarding the method and apparatus for drilling a through hole in the work peripheral wall is that productivity is low in the conventional method and apparatus in order to open a through hole without a burr.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method and apparatus for drilling a through hole in a work peripheral wall that prevents burrs from occurring at least on the inner peripheral surface of the cylindrical portion, has high productivity, and can significantly reduce processing costs. Is to provide.

The present invention has the following configuration in order to achieve the above object.
According to one aspect of the method for drilling a through hole in a work peripheral wall according to the present invention, a method of drilling a through hole by press punching in the peripheral wall of the cylindrical part of a work having at least a part of the cylindrical part. And positioning the workpiece on a die that abuts the outer wall surface of the portion where the through hole of the peripheral wall of the cylindrical portion is to be opened, and a punch protruding from a rod-shaped cored bar held in a cantilever manner, Insert the inside of the cylindrical part in a state facing the inner wall surface of the part where the through hole is to be opened, and move the pressure relatively in the direction in which the punch is punched between the die through the cored bar At the same time, from the work through hole provided in the part on the opposite side of the peripheral wall part where the through hole of the work is to be opened, the inside of the work is brought into contact with the surface opposite to the surface of the core bar from which the punch is projected. The pressing pin inserted into the core bar and pan Punch by moving the pressure to bored implanted in the through-hole to the peripheral wall from the inside of the tubular portion together, and the holder movable in the press punching direction while holding the core metal cantilevered, The pressing pins are simultaneously pressed and moved by a pressing board .

Moreover, according to one form of the drilling method of the through-hole in the workpiece | work surrounding wall concerning this invention, both the opposing parts in the peripheral wall of this cylindrical part of the workpiece | work which has a cylindrical part at least in part are carried out by press punching. A method of drilling a through hole, in which a work through hole, which is a hole smaller than a through hole to be opened later, is formed in a cylindrical shape on a part opposite to the peripheral wall part where the through hole is to be opened first. A rod-like shape in which a punch is punched from the outside of the part and the workpiece is positioned on a die that abuts the outer wall surface of the part where the through-hole is to be opened at the beginning of the peripheral wall of the cylindrical part and is held in a cantilever manner The punch projecting from the cored bar is inserted into the cylindrical part so as to face the inner wall surface of the part where the through-hole should be opened first, and the punch is placed between the die and the die through the cored bar. Relative to the direction of punching Simultaneously with the pressure movement, a pressing pin inserted into the work so as to come into contact with the surface opposite to the surface of the core bar from which the punch protrudes is added together with the core bar and the punch from the work through hole. A holder that can be moved in the press punching direction while holding the core metal in a cantilever manner so as to punch the punch into the peripheral wall from the inside of the cylindrical part by punching and punching a through hole; The pin is simultaneously pressed and moved by a push plate, and the workpiece is positioned on a die that abuts on the outer wall surface of the portion corresponding to the work through hole where the through hole is to be opened after the peripheral wall of the cylindrical portion. The inner side of the cylindrical part is in a state where the punch projecting from the rod-shaped cored bar held in a cantilever state faces the inner wall surface of the part corresponding to the working through hole to be opened later. Through the cored bar The punch is moved relative to the die in the direction in which punching is performed, and at the same time, from the through hole drilled in the previous process to the surface opposite to the surface of the core bar from which the punch is projected. A through hole that encloses the work through hole by punching the punch pin into the peripheral wall from the inside of the cylindrical part by pressing and moving the pressing pin inserted into the workpiece so as to come into contact with the core metal and the punch. The holder is movable in the press punching direction while holding the cored bar in a cantilevered manner and the pressing pin is simultaneously pressed and moved by a pressing plate .

According to one aspect of the device for drilling a through hole in a work peripheral wall according to the present invention, the device for drilling a through hole by press punching in the peripheral wall of the tubular portion of the work having at least a part of the tubular portion. A die that comes into contact with an outer wall surface of a portion in which the through-hole of the peripheral wall of the cylindrical portion is to be opened, a holder that is movable in a press punching direction, and is held in a cantilever manner, and a tip end side of the workpiece is A cored bar that is inserted into the cylindrical part so that it can move in the punching direction of the press, and an inner wall surface of a part that protrudes from the leading end side of the cored bar and through which a through hole is to be opened The punch is inserted from the punch inserted into the cylindrical portion together with the tip end side of the core bar in a facing state, and the work through hole provided in the portion opposite to the peripheral wall portion where the through hole of the workpiece is to be opened. Opposite to the surface of the protruding core A pressing pin which is inserted into a work in so as to contact the surface, drilling through-holes are implanted into the peripheral wall of the punch from the inside of the cylindrical portion by relatively pressure movement relative to the die As described above, the holder that holds the mandrel and the pressing plate that simultaneously pressurizes and moves the pressing pin are provided.
Moreover, according to one form of the through-hole drilling device in the workpiece peripheral wall according to the present invention, the core metal holds the core metal on the rear end side opposite to the front end side where the punch is projected. It can be characterized by being detachably fixed to the holder .

Moreover, according to one form of the through-hole drilling device in the workpiece peripheral wall according to the present invention, the end surface of the punch is chamfered so as to follow the shape of the inner peripheral surface of the cylindrical portion. It can be.
Further, according to one embodiment of the device for drilling a through hole in the work peripheral wall according to the present invention, when the through hole is drilled, the punched hole is opened so as to open the through hole. It is possible to provide a suction means for sucking and removing from.

Moreover, according to one form of the through-hole drilling device in the workpiece peripheral wall according to the present invention, both the opposing portions of the peripheral wall of the cylindrical portion of the workpiece having the cylindrical portion at least in part are formed by press punching. An apparatus for drilling a through-hole, wherein a work through-hole, which is a hole smaller than a through-hole to be opened later, is formed in a cylindrical shape on a part opposite to the peripheral wall part where the through-hole is to be opened first. First punching device unit provided with a punch that is punched from the outside of the part, a die that comes into contact with the outer wall surface of the part where the through-hole of the peripheral wall of the cylindrical part is to be opened, and movable in the press punching direction A holder, a metal core formed in a rod shape so that the tip side is inserted into the cylindrical portion of the workpiece and can be moved in the punching direction of the press, of projecting from the front end side A punch to be inserted with the front end side of the core metal to the inside of the cylindrical portion in a state facing the inner wall surface of the part to the through-hole is opened, the through hole or projecting from the through hole for the work, A pressing pin that is inserted into the workpiece so as to abut the surface opposite to the surface of the core bar from which the punch is protruded, and the punch is moved under pressure relative to the die to A second drilling device unit provided with a pressing plate for simultaneously pressing and moving the holder holding the mandrel and the pressing pin so as to punch through the peripheral wall from the inside to form a through hole; you.

  Moreover, according to the workpiece according to the present invention, the workpiece has a cylindrical portion at least in part, and the through-hole is opened in the peripheral wall of the cylindrical portion by the through-hole drilling device in the peripheral wall of the workpiece. Can be characterized.

  According to the through-hole drilling method and drilling device in the workpiece peripheral wall according to the present invention, at least the inner peripheral surface of the cylindrical portion is prevented from generating burrs, the productivity is high, and the machining cost is greatly reduced. it can.

Hereinafter, an example of the best mode of a through hole drilling method and a drilling device in a work peripheral wall according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a front view showing an outline of a drilling device according to the present invention. FIG. 2 is a cross-sectional view (a) and a bottom view (b) showing an example of a workpiece processed by the drilling device of the invention.
The drilling device of this embodiment is a device that drills a through hole in the peripheral wall of the cylindrical portion of the workpiece by press punching.
Reference numeral 10 denotes a workpiece, which is an example having a cylindrical portion 12 at least in part. As shown in FIG. 2, one side (lower surface side) is wide open, the other side is formed with a small diameter, and its end is closed. Note that the workpiece 10 shown in FIG. 2 is a part of an airbag apparatus, and is a metal part formed by cutting. For example, it is a small part having an inner diameter of about 9 mm and a peripheral wall thickness of about 1.5 mm at a portion where a through hole is to be opened. In the drilling device of the present embodiment, an elliptical through hole 70 (see FIGS. 18, 19, etc.) having a major axis of 6 mm × minor axis of about 5 mm is provided in the workpiece 10 in the axial direction at a position equivalent to four circumferences. Drill a total of 8 pieces.

Reference numeral 20 denotes a die, which is one die for machining the workpiece 10. The die 20 is formed so as to suitably receive the workpiece 10 so as to come into contact with an outer wall surface of a portion where the through hole 70 of the peripheral wall 15 of the cylindrical portion 12 is to be opened. As shown in FIG. 1, it is formed in the circular arc shape 20a, and since the corner | angular part used as a cutting edge can be formed in an obtuse angle, it has a form which is hard to damage.
Reference numeral 24 denotes a discharge hole for a punched residue, which has a shape (FIGS. 4 to 7) that expands downward in a tapered shape. As a result, the punched residue 80 (FIG. 6) is suitably discharged without being caught in the middle.

Reference numeral 30 denotes a punch, which protrudes from a bar-shaped cored bar 32 held in a cantilever manner. A punch 30 is projected in a direction perpendicular to the axis of the core metal 32. In the present embodiment, it is provided in a form that protrudes shortly below with a length equivalent to the thickness of the peripheral wall 15. Thus, since the core 30 can be formed thicker because the punch 30 is shorter, the life of the mold can be extended. That is, the escape stroke of the punch 30 is short, and the core metal 32 inserted into the work 10 can be thickened accordingly. Therefore, the strength can be increased and the life can be extended. Further, the punch 30 itself is shortened and is not easily damaged. Thereby, productivity can be improved and processing costs can be significantly reduced.
In this embodiment, the punch 30 and the cored bar 32 are integrally formed. However, in some cases, the punch 30 formed as a separate body is embedded in the tip side of the cored bar 32 and fixed, The punch 30 may be formed so as to protrude from the core metal 32 by a predetermined length.
Further, as shown in FIG. 4, the punch 30 is inserted into the cylindrical portion 12 so as to face the inner wall surface of the portion where the through-hole 70 is to be opened during the press punching process. Note that the punch 30 is relatively inserted into the cylindrical portion 12 also by transporting the workpiece 10 with a feeder and fitting the tip of the core 32 on which the punch 30 is projected.

The metal core 32 has a rear end side 32b (FIG. 3) opposite to the front end side 32a (FIG. 3) on which the punch 30 projects, and a holding hole of a holder (elevating block 40) for holding the metal core 32. It is inserted in 42 in the horizontal direction and is detachably fixed. A flat portion for preventing rotation is provided on the side surface of the cored bar 32. For this reason, it can exchange easily and suitably.
The fixed state of the metal core 32 is a cantilever in which the distal end side 32a protrudes in the horizontal direction, and the metal core 32 is formed in a rod shape as described above. For this reason, when the punching process is performed, if there is no means (for example, a pressing pin 35 described later) for pressing the distal end side 32a of the core metal 32, the longer the protruding portion is, the longer the core metal 32 is pressed. A large moment is applied by the pressure at the time of carrying out, and it becomes easy to break.
Further, a protruding portion 40a (FIG. 3) extended in the horizontal direction is provided so that the rear end portion 32b of the cored bar 32 can be inserted into the elevating block 40 so that the strength of the cored bar 32 can be suitably maintained. It has been. According to this, the shape of the cored bar 32 can be made into a simple rod shape, and manufacturing cost can be reduced. In addition, the shape of the metal core 32 should just be what can insert the front end side 32a inside the workpiece | work 10, and the shape of the rear-end part 32b is not specifically limited. The shape of the rear end portion 32b may be appropriately selected as long as it can be suitably set.

Reference numeral 35 denotes a pressing pin, which is a surface 33 opposite to the surface of the core bar from which the punch 30 is protruded from a work through hole 72 provided in a portion opposite to the peripheral wall portion where the through hole 70 of the workpiece is to be opened. Is inserted into the workpiece 10 so as to abut against the workpiece 10.
The pressing pin 35 is pressed and moved together with the cored bar 32 and the punch 30 as will be described later. According to this, the pressing pin 35 is in a state of supporting the core metal 32 from above, and as a result, the punch 30 can be pressed and the through hole 70 can be formed. That is, the core metal 32 can be supported and pressed from above by both the lifting block 40 and the pressing pin 35, and the punch 30 can be driven into the peripheral wall 15 from the inside.
According to this, it is possible to prevent the moment when the cored bar 32 is cantilevered, and it is possible to suitably prevent the cored bar 32 and the punch 30 from being damaged. Therefore, the life of the mold can be greatly prolonged, and the productivity can be greatly improved. For this reason, production costs can be greatly reduced.

P (50) is a pressurizing means, and the punch 30 is moved through the cored bar 32 relative to the direction in which the punch 30 is punched (adjacent direction) (in this embodiment, downward). At the same time, the pressing pin 35 is pressed and moved together with the core 32 and the punch 30 to drive the punch 30 into the peripheral wall 15 of the workpiece from the inside of the cylindrical portion 12, causing shearing and breaking, and through holes. To drill.
In this embodiment, first, the pressing pin 35 is lowered (see FIGS. 4 and 5), and the punch 30 is simultaneously lowered (see FIGS. 5 and 6) via the cored bar 32 held by the elevating block 40 from the middle. It has become. Further, the punch 30 is driven downward in a direction perpendicular to the peripheral wall 15. Needless to say, the punching direction for forming the through hole 70 is not limited to the vertical direction as in this embodiment. For example, the workpiece 10 may be set in a progressive die or the like with the workpiece 10 standing, and the punch 30 may be driven in the horizontal direction to form the through hole 70.
For example, a cylinder device may be used as the pressurizing device of the pressurizing unit 50.
In addition, in order for the fracture to be appropriately performed following the shearing, it is necessary that the clearance between the die 20 and the punch 30 is appropriate. An appropriate value for this appropriate clearance is empirically known. For example, when opening a circular through-hole in an iron-based material, the inner diameter of the die and the outer diameter of the punch may be set so as to satisfy the following relationship.
Die inner diameter = punch outer diameter + {work material thickness x (5-10%)} x 2

  S (55) is a return elastic means, for example, a return spring 56 (FIGS. 3 to 7) and a return means 57 (FIG. 3) of the pressing pin 35 may be used. As these return spring 56 and return means 57, coil springs can be employed. The return spring 56 is arranged and mounted between the elevating block 40 and the base board 43 (FIGS. 3 to 7). With this return elastic means 56, the punch 30 can be raised and returned to the position before pressurization via the elevating block 40 and the cored bar 32 after the pressurizing step is completed. Furthermore, the pressing means 35 can be raised and returned to the position before pressurization by the return means 57.

Moreover, as shown in FIGS. 8, 9, 20, and 21 (description on the right half), the end surface serving as the cutting edge of the punch 30 of the present embodiment follows the shape of the inner peripheral surface of the cylindrical portion 12 of the workpiece 10. Chamfered so that. (FIG. 8 is a front view showing a state in which the through-hole is started to be extracted, and FIG. 9 is a front view showing a state in which the through-hole 70 has been extracted. FIG. 20 is a front view showing the shape of the punch 30 (a And bottom view (b).)
In this embodiment, the left and right portions of the punch 30 are chamfered corresponding to the circumferential surface on the inner side of the cylindrical portion 12 to form two chamfered portions 30a. That is, as is apparent from the description of the right half of FIGS. 20 and 21, chamfered portions 30 a that are inclined with respect to the flat end surface 30 f perpendicular to the driving direction of the punch 30 are formed on both sides of the punch 30. Yes. Thereby, the angle of each corner | angular part in the end surface of the punch 30 in which this chamfered part 30a was formed becomes an obtuse angle larger than 90 degrees. The flat end surface 30f and the inclined surface of the chamfered portion 30a are parallel to the axis of the cored bar 32.
By forming the chamfered portion 30a in this way, the end surface of the punch 30 can be dispersedly brought into contact with the inner peripheral surface of the cylindrical portion 12, and the punch 30 can be prevented from being damaged. Similar to the cutting of the scissors, the shear angle is generated by the presence of the chamfered portion 30 a of the punch 30, and this can disperse the pressure during pressing, and the through hole 70 can be suitably opened. And since the said corner | angular part is an obtuse angle, the blade chip | tip of the punch 30 does not arise easily.
Further, as is apparent from the description on the right half of FIG. 21, the tip side 32a of the cored bar 32 provided with the punch 30 is thickened corresponding to the height H3 of the chamfered portion 30a formed and shaved. Even so, it can be inserted inside the workpiece 10. The rigidity and durability of the cored bar 32 can be increased as the cross-sectional area of the distal end side 32a of the cored bar 32 becomes wider. In addition, description of the left half of FIG. 20 is sectional drawing described for the case where the chamfering part 30a is not formed for the comparison.
This also extends the life of the mold and reduces the processing cost.
Further, according to the punch 30 having the chamfered portion 30 a on the end surface, it is possible to prevent the punched residue 80 from sticking and sticking to the end surface of the punch 30. This can also improve productivity.

V (60) is a suction means (FIG. 1), and when the through hole 70 (FIG. 6) is drilled, the punch 80 (FIG. 6) is removed from the die 20 so as to open the through hole 70. The suction hole 24 is removed by suction.
According to this, since the suction residue is generated when the extraction residue 80 is generated and suction removal is performed at the moment when the extraction residue 80 is generated, the extraction residue 80 can be suitably opened without remaining in the through hole 70.
As the suction means 60, as shown in FIG. 10, a negative pressure suction device that generates a negative pressure by the venturi effect by opening the compressed air from the compressed air source 62 to the flow path 64 having a larger sectional area is suitable. Can be used. In a normal state, a negative pressure state is maintained, and suction can be suitably performed when the drawn residue 80 is generated. Note that the extracted residue 80 sucked into the flow path 64 through the discharge hole 24 is blown away by the air flow (discharge air flow) flowing through the flow path 64. Therefore, the removal waste 80 can be suitably discharged without adding a special configuration to the suction means 60.
According to this method using compressed air, a compressor device generally used in a normal factory may be used and can be easily configured. The suction means is not limited to this, and other decompression (vacuum) devices may be used.

  In the above-described device for drilling a through hole in the peripheral wall of a work 10 having at least a part of the cylindrical part 12, the fact that the through hole 70 is opened from the inside in the peripheral wall 15 of the cylindrical part 12 It can be verified by inspecting the condition of the rupture and breakage.

Next, a process of drilling the through hole 70 in the peripheral wall 15 of the cylindrical portion 12 of the workpiece 10 using the drilling apparatus having the above configuration will be described with reference to FIGS.
FIG. 3 is a cross-sectional view showing a state where the mold before the workpiece 10 is set in the mold is opened. About the structure demonstrated above, the same code | symbol is attached | subjected and description is abbreviate | omitted.
In order to prevent the workpiece 10 from rotating, the workpiece 10 is fitted with a rectangular jig 16 and fixed with a screw 17. Reference numeral 22 denotes a receiving portion that receives the jig 16 at a predetermined position and positions the workpiece 10. Reference numeral 44 denotes a lifting guide that guides the vertical movement of the lifting block 40.
Reference numeral 45 denotes a push board, which is pressed by the pressurizing means 50 (FIG. 1). Two pressing pins 35 are attached to the pressing plate 45. Further, a push block 46 for raising and lowering blocks is provided at a pressing portion 45 a that presses the raising and lowering block 40 of the push board 45. The lifting block push pin 46 is always biased so as to protrude by a spring 47, and acts to push the lifting block 40 downward when the punch 30 is removed from the workpiece 10.
Reference numeral 52 denotes a stripper portion, which is a portion that holds the workpiece 10 when the punch 30 is pulled out of the workpiece 10. The stripper portion 52 is provided with two guide holes 53 so that the pressing pin 35 can be inserted therethrough.

FIG. 4 is a cross-sectional view showing a state in which the workpiece 10 is set in a mold.
Two punches projecting from a bar-shaped cored bar 32 held in a cantilever manner while the workpiece 10 is positioned 20 on a die that abuts the outer wall surface of the portion of the cylindrical wall 15 where the through hole 70 should be opened. 30 is inserted into the cylindrical portion 12 so as to face the inner wall surface of the portion where the through hole 70 is to be opened.
At this point, the push plate 45 is at the top dead center, and the push pin 35 is located above the stripper portion 52. In addition, the push portion 45 a is also located above the lifting block 40.

Next, as shown in FIG. 5, the push plate 45 is lowered, and the pushing portion 45 a is brought into contact with the upper surface of the elevating block 40. At the same time, the pressing pin 35 is also inserted into the work 10 from the working through hole 72 (FIG. 4), and is brought into contact with the surface 33 opposite to the surface of the core bar from which the punch 30 is projected.
As shown in FIG. 8, a chamfered portion 30 a is formed on the end surface of the punch 30, and four corner portions formed by the chamfered portion 30 a first contact the inner wall surface of the peripheral wall 15. As a result, a shear angle is generated as described above, and the through hole 70 can be suitably opened.
Further, the lifting block push pin 46 moves upward against the urging force of the spring 47 and enters the holding hole 48.

Then, as shown in FIG. 6, the push plate 45 is further lowered to press the elevating block 40, and the punch 30 is relatively pressed in the direction in which the punch 30 is punched with the die 20 through the cored bar 32. Simultaneously with the movement, the work through-hole 72 provided in the part on the opposite side to the peripheral wall part where the workpiece through-hole 70 is to be opened contacts the surface 33 opposite to the surface of the core bar from which the punch 30 is projected. By pressing and moving the pressing pin 35 inserted so as to come into contact with the core metal 32 and the punch 30, the punch 30 is driven into the peripheral wall 15 from the inside of the cylindrical portion 12 to pierce the through hole 70.
As shown in FIG. 9, the punch 30 is driven. At this time, according to the cutting edge of the end face of the punch 30 in which the chamfered portion 30a is formed, a suitable shear angle is generated as described above, and the through hole 70 is preferably formed. Can be opened.
Further, when the through hole 70 is formed in this manner, the punched-out residue 80 is removed by suction by the suction means 60 from the punched-out discharge hole 24 of the die 20 so that the through-hole 70 is preferably opened. As a result, the scrap 80 can be discharged reliably and productivity can be improved.

Next, as shown in FIG. 7, when the punch 30 is pulled out of the workpiece 10, the lifting block push pin 46 protrudes downward by the spring 47 pressure to press the lifting block 40. Thereby, it acts so that the front end side 32a of the metal core 32 provided with two punches 30 is raised. For this reason, the punch 30 that tends to be bent forward can be suitably removed from the through hole 70 of the workpiece 10.
More specifically, when the lifting block push pin 46 is based on the return spring 56, it pushes the portion (the rear portion 40b (FIG. 3)) of the lifting block 40 opposite to the protruding portion 40a side from above. ing. There is a slight backlash between the elevating block 40 and the elevating guide 44 to allow the elevating block 40 to move up and down. According to the backlash, when the punch 30 is stripped from the workpiece 10, the leading end side 32a of the cored bar 32 tends to be inclined downward by biting. The longer the metal core 32 is, the longer the downward displacement distance of the distal end side 32a is. The inclination generated in this manner can be returned to the original horizontal state by the lifting block push pin 46 pushing the rear portion 40b of the lifting block. This is because the pressing force of the lifting block push pin 46 acts to lift the distal end side 32a of the cored bar 32 with the return spring 56 as a fulcrum. According to this, the through-hole 70 which the punch 30 opened in the workpiece | work 10 can be stripped suitably.

According to the above process, since the punch 30 is driven from the inside to open the through hole 70, no burr is generated on the inner wall surface of the cylindrical portion 12. Therefore, it is not necessary to perform a deburring operation in a later process. In addition, since the punch 30 is also pressed by the pressing pin 35, a pressing pressure can be suitably applied, and a relatively large through hole can also be suitably opened. And since the metal core 32 is supported from the top by the raising / lowering block 40 and the two press pins 35, the bending deformation which arises in the case of a cantilever can be prevented. Therefore, damage to the punch 30 and the cored bar 32 can be prevented, and the life of the mold can be greatly extended.
For this reason, productivity can be improved and processing cost can be reduced significantly.

Next, a method and apparatus for drilling the working through hole 72 in the peripheral wall 15 of the workpiece 10 will be described with reference to FIGS.
In this apparatus, a work through hole 72, which is a hole smaller than the through hole 70 to be opened later, is formed from the outside of the cylindrical portion on the opposite side of the peripheral wall portion where the through hole 70 is to be opened first. It is the 1st drilling device unit 100 provided with the punch 37 which drives and pierces.
And the apparatus demonstrated to FIGS. 3-7 with respect to this 1st drilling device unit 100 turns into 2nd drilling device unit 200 (FIG. 3).

  Reference numeral 27 denotes a die, which is provided at a tip portion 28a of a rod-shaped die core bar 28 held in a cantilever manner. The portion of the die 27 in this embodiment is formed on the upper portion of the side wall of the die core metal 28. As shown in FIGS. 12 and 13, the die 27 is inserted into the cylindrical portion 12 so as to face the inner wall surface of the portion where the work through hole 72 is to be opened, as shown in FIGS. Note that the die 27 is also relatively inserted into the cylindrical portion 12 by transporting the workpiece 10 with a feeder and fitting the tip 10 a of the die core bar 28 provided with the die 27.

The die core metal 28 has a rear end side 28b opposite to the tip end side 28a where the die 27 is provided, and is inserted into the holding hole 41a of the holder 41 holding the die core metal 28 in the horizontal direction. It is fixed in a removable manner. A flat portion for preventing rotation is provided on the side surface of the die core metal 28. For this reason, it can exchange easily and suitably.
Further, a punched hole discharge hole 29 is penetrated through the axial center of the die core 28 and communicates with a hole 27 a forming the die 27. A passage 29a connected to a compressed air source (not shown) is communicated with the outlet hole 29 of the punched residue so that compressed air is introduced from the front end side 28a. According to this, the punched residue 82 (FIG. 13) can be discharged by blowing away from the front end side 28a of the die cored bar 28 to the rear end side 28b. Therefore, productivity can be improved.

Further, in order to prevent the workpiece 10 from rotating, the workpiece 10 is fixed to a jig 16 having a rectangular outer shape with a screw 17. Reference numeral 23 denotes a receiving portion that receives the jig 16 at a predetermined position and positions the workpiece 10. Reference numeral 25 denotes a receiving portion of the processing portion, which is a portion that receives the cylindrical portion 12 on which the workpiece 10 is processed.
Reference numeral 90 denotes a press board, which is pressed by the pressurizing means 91. Two pin-shaped punches 37 (circular in cross section) are attached to the press platen 90.
Reference numeral 26 denotes a stripper portion that is a portion that holds the workpiece 10 when the punch 37 is pulled out of the workpiece 10. In this embodiment, it is provided integrally with the receiving portion 25 of the processing portion. The stripper portion 26 is provided with two guide holes 38 so that the punch 37 can be inserted therethrough.

Next, a process of drilling the working through hole 72 in the peripheral wall 15 of the cylindrical portion 12 of the workpiece 10 using the first drilling device unit 100 having the above configuration will be described with reference to FIGS. To do.
FIG. 11 is a cross-sectional view showing a state where the mold before the workpiece 10 is set in the mold is opened.
At this time, the press platen 90 is at the top dead center, and the punch 37 is located apart upward. In addition, about the pressurization means and return means concerning this press platen 90, what is necessary is just to use suitably the well-known technique which was demonstrated with FIG.

FIG. 12 is a cross-sectional view showing a state in which the work 10 is set in a mold, the punch 37 is lowered, and the working through hole 72 is formed.
The diameter of the working through hole 72 can be set to be relatively small compared to the inner diameter of the workpiece 10. It is a hole that is at least one size smaller than the through hole 70 that is finally drilled.
Therefore, it is possible to suppress the cross section of the cutting edge of the die 27 inserted into the cylindrical portion 12 in order to open the working through hole 72 from being an acute corner. For this reason, the die life of the die 27 is not shortened, and productivity can be improved.

FIG. 13 is a cross-sectional view showing a state where the punch 37 is further lowered to penetrate the peripheral wall 15 and the work through hole 72 is formed.
As described above, the punched residue 82 is blown off by the air and discharged from the discharge hole 29 of the punched residue. Since the through-hole 72 for operation is smaller than the through-hole 70, the punched residue 82 is relatively small and can be suitably discharged without clogging the discharge hole 29. According to this, the working through hole 72 can be efficiently drilled.
By the way, the working through-hole 72 is provided as a throw-away hole because it completely disappears when the through-hole 70 containing the portion is formed.
In addition, since this working through-hole 72 is provided as a discard hole, there is a case where high-precision machining is not required. In that case, the working through hole 72 may be drilled not only by the drilling method as in the present embodiment but also by other known drilling methods.

Next, using the first drilling device unit 100 (FIG. 11) and the second drilling device unit 200 (FIG. 3) configured as described above, the circumferential wall 15 of the cylindrical portion 12 of the workpiece 10 is circumferentially connected. The first to sixth steps for forming a total of eight through-holes, two in the axial direction, at four equal positions will be described with reference to FIGS.
First, as shown in FIG. 14, in the first step, the punch 37 is driven from the outside by the first drilling device unit 100, and two first work through holes 72 a are drilled in the work 10.
Next, as shown in FIG. 15, in the second step, the second working through-hole is moved by 90 ° in the circumferential direction from the first working through-hole 72 a by the first drilling device unit 100. Two 72b are drilled. At this time, the work holder 16 may be rotated 90 degrees clockwise and fixed to perform the punching operation.

Next, as shown in FIG. 16, in the third step, the work holder 16 is rotated 90 degrees counterclockwise and fixed, and the peripheral wall facing the first work through hole 72a by the second drilling device unit 200. 15, the punch 30 is driven from the inside, and two first through holes 70 a are formed in the work 10.
Next, as shown in FIG. 17, in the fourth step, the work holder 16 is rotated 90 degrees clockwise, and the second drilling device unit 200 moves the inner side toward the peripheral wall 15 facing the second work through hole 72b. Then, the punch 30 is driven in, and two second through holes 70b are formed in the workpiece 10.
Next, as shown in FIG. 18, in the fifth step, the work holder 16 is rotated 90 degrees clockwise to the peripheral wall 15 provided with the first work through hole 72 a by the second drilling device unit 200. The punch 30 is driven from the inside, and two third through holes 70 c are formed in the work 10. As a result, the first working through hole 72a provided as the discard hole is removed, and the third through hole 70c is formed.
Next, as shown in FIG. 19, in the sixth step, the work holder 16 is rotated 90 degrees clockwise to the peripheral wall 15 provided with the second work through hole 72 b by the second drilling device unit 200. The punch 30 is driven from the inside, and two fourth through holes 70d are formed in the work 10. As a result, the second working through hole 72b provided as a discard hole is removed, and the fourth through hole 70d is formed.
According to the above process, eight through-holes 70 (ad) can be efficiently drilled, and productivity can be improved.

In the above embodiment, the case of drilling an oval through hole has been described. However, the present invention is not limited to this, and the case of drilling a through hole of another shape such as a circle or an ellipse. Of course, the present invention can also be applied.
In addition, the material of each component such as punch, die, and cored bar is appropriately selected from known materials according to the specification conditions in order to obtain a suitable mold with high drilling accuracy and long life. That's fine. Furthermore, with respect to punches and dies, a known surface hardening technique may be used as necessary to improve the durability.
As described above, the present invention has been variously described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. Of course you get.

It is a front view which shows one form of the drilling apparatus concerning this invention. It is sectional drawing and a bottom view which show an example of a workpiece | work. It is sectional drawing which shows one form of the 2nd drilling device unit concerning this invention. It is sectional drawing explaining the drilling process of the state which set the workpiece | work. It is sectional drawing explaining the drilling process of the state which starts extracting a through-hole. It is sectional drawing explaining the drilling process of the state which finished extracting a through-hole. It is sectional drawing explaining the drilling process at the time of extracting a punch from a workpiece | work. It is a front view which shows the detail of punch vicinity of the state which begins to extract a through-hole. It is a front view which shows the detail of the punch vicinity of the state which finished extracting a through-hole. It is sectional drawing which shows one form of a negative pressure suction device. It is sectional drawing which shows one form of the 1st drilling device unit concerning this invention. It is sectional drawing explaining the drilling process of the state in drilling the working through-hole. It is sectional drawing explaining the drilling process of the state which finished extracting the through-hole for work. It is the front view and top view which show the workpiece | work in which the 1st through-hole for work was pierced. It is the front view and top view which show the workpiece | work with which the 2nd through-hole for work was pierced. It is the front view and top view which show the workpiece | work with which the 1st through-hole was drilled. It is the front view and top view which show the workpiece | work in which the 2nd through-hole was pierced. It is the front view and top view which show the workpiece | work with which the 3rd through-hole was drilled. It is the front view and top view which show the workpiece | work with which the 4th through-hole was drilled. It is the front view and bottom view which show the example of a form of a punch. It is sectional drawing which illustrates the example of a form of a punch typically. It is explanatory drawing explaining the conventional drilling apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Work 12 Cylindrical part 15 Peripheral wall 20 Die 24 Ejection hole 30 Punch 30a Chamfering part 32 Core metal 35 Pressing pin 37 Punch 40 Lifting block 42 Holding hole 50 Pressurizing means 60 Suction means 62 Compressed air source 70 Through-hole 72 Work penetration Hole 80 Dregs 82 Dregs 100 First drilling device unit 200 Second drilling device unit

Claims (8)

It is a method of drilling a through-hole by press punching in the peripheral wall of the cylindrical part of a workpiece having at least a part of the cylindrical part,
The workpiece is positioned on a die that abuts the outer wall surface of the portion where the through-hole of the peripheral wall of the cylindrical portion is to be opened, and a punch protruding from a bar-shaped cored bar held in a cantilever manner is used as a through-hole. Insert inside the cylindrical part in a state facing the inner wall surface of the part to be opened,
Through the metal core, the punch is relatively moved in the direction of punching with the die, and at the same time, the work penetration provided in the part on the opposite side of the peripheral wall part where the through hole of the workpiece is to be opened By pressing and moving the pressing pin inserted into the workpiece so as to abut the surface opposite to the surface of the core bar from which the punch is protruded from the hole, the punch is moved into the cylindrical shape. A holder that can be held in the cantilever and moved in the press punching direction, and the pressing pin are simultaneously pressed and moved by a press so that the through hole is punched into the peripheral wall from the inside of the part. A method for drilling a through-hole in a work peripheral wall. It is a method of drilling through holes by press punching in both opposing portions of the peripheral wall of the cylindrical part of the workpiece having at least a part of the cylindrical part,
A work through hole, which is a hole smaller than the through hole to be opened later, is formed in the part opposite to the peripheral wall part where the through hole is to be opened at the beginning of the workpiece by punching from the outside of the cylindrical part. ,
The workpiece is positioned on a die that comes into contact with the outer wall surface of the portion where the through-hole is to be opened at the beginning of the peripheral wall of the cylindrical portion, and a punch protruding from a rod-shaped core metal held in a cantilever manner is first used. Inserted into the cylindrical portion in a state facing the inner wall surface of the portion where the through hole should be opened,
At the same time, the punch is relatively moved in the direction in which punching is performed between the die and the die through the core bar, and at the same time, the punch is protruded from the surface of the core bar on which the punch protrudes. a pressing pin which is inserted into a work in so as to contact the surface, so as to bored implanted in the through-hole to the peripheral wall of the punch from the inside of the tubular portion by causing pressure movement together with the core metal and the punch , Holding the mandrel in a cantilevered manner and moving the holder in the press punching direction and the pressing pin at the same time by a press plate,
The work is positioned on a die that abuts the outer wall surface of the portion corresponding to the through hole for work where a through hole is to be opened after the peripheral wall of the cylindrical portion, and a rod-shaped core bar held in a cantilever manner. The projecting punch is inserted into the cylindrical portion in a state facing the inner wall surface of the portion corresponding to the working through hole where the through hole is to be opened later,
The surface of the metal core on which the punch protrudes from the through-hole formed in the previous process at the same time that the punch is relatively pressed and moved in the direction of punching with the die through the metal core The pressing pin inserted into the workpiece so as to abut the surface opposite to the surface of the workpiece is pressed and moved together with the cored bar and the punch, so that the punch is driven into the peripheral wall from the inside of the cylindrical portion, and the working penetration A holder capable of moving in the press punching direction while holding the core metal in a cantilever manner so as to form a through hole containing the hole, and the pressing pin are simultaneously moved by pressing with a pressing plate. A method for drilling a through hole in a work peripheral wall. An apparatus for drilling a through-hole by press punching in a peripheral wall of the cylindrical part of a workpiece having at least a part of the cylindrical part,
A die that abuts on the outer wall surface of the portion where the through-hole of the peripheral wall of the cylindrical portion is to be opened;
A holder that can move in the direction of punching,
A cored bar which is held in a cantilevered manner and is formed in a rod shape so that the tip side can be inserted into the inside of the cylindrical part of the workpiece and moved in the punching direction of the press;
A punch projecting on the tip side of the cored bar and inserted with the tip side of the cored bar into the cylindrical part in a state facing the inner wall surface of the part where the through hole is to be opened;
A punch is inserted into the work so as to abut the surface opposite to the surface of the cored bar from the work through hole provided on the opposite side of the peripheral wall portion where the through hole of the work is to be opened. A pressing pin;
The holder holding the mandrel, and the pressing pin, so that the punch is moved relative to the die and driven into the peripheral wall from the inside of the cylindrical portion to form a through hole; a bored device of the through-hole in the workpiece wall, characterized by comprising a pushing plate for the pressure movement at the same time. 4. The work peripheral wall according to claim 3, wherein the core metal is detachably fixed to a holder that holds the core metal at a rear end side opposite to a tip end side where the punch is projected. A through-hole drilling device.   The end surface of the punch is chamfered so as to conform to the shape of the inner peripheral surface of the cylindrical portion.   6. The suction device according to claim 3, further comprising suction means for sucking and removing the punched waste from the punched-out hole of the die so as to open the through-hole when the through-hole is formed. Drilling device for through-holes in the workpiece peripheral wall An apparatus for punching through holes by press punching in both of the opposing portions of the peripheral wall of the cylindrical part of the workpiece having at least a part of the cylindrical part,
A punch for punching a work through-hole, which is a hole smaller than a through-hole to be opened later, from the outside of the cylindrical part in a portion opposite to the peripheral wall portion to be opened at the beginning of the workpiece. A first drilling device unit comprising:
A die that comes into contact with an outer wall surface of a portion in which a through hole of a peripheral wall of the cylindrical portion is to be opened, a holder that is movable in a press punching direction, and cantilevered by the holder, and a tip side of the cylindrical shape of the workpiece A state that faces the inner wall surface of the core bar that is inserted into the inside of the part and is formed in a rod shape so as to be movable in the punching direction of the press, and protruding from the tip side of the core bar and the through hole is to be opened The punch is inserted into the cylindrical portion together with the tip side of the cored bar, and the surface opposite to the surface of the cored bar from which the punch is projected from the working through hole or the projected through hole A pressing pin that is inserted into the workpiece so as to abut against the die , and the punch is moved by pressure relative to the die so as to be punched into the peripheral wall from the inside of the cylindrical portion to form a through hole. The holder holding the mandrel and the pusher And a pin, punched device of the through-hole in the workpiece wall, characterized by comprising a second drilling device unit comprising a press plate for pressing simultaneously moved.   A workpiece having at least a part of a cylindrical part, wherein the through hole is opened in the peripheral wall of the cylindrical part by the device for forming a through hole in the peripheral wall of the work according to claim 3, 4, 5, 6, or 7. Work characterized by

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