JP2011079101A - Knock-out device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a knock-out device for driving an upper die unit for punching a printed circuit board in which friction force acting on a movable pad is lowered, abrasion between an outer peripheral face of the movable pad and an inner peripheral face of a storage hole is reduced, and performance in punching the printed circuit board is improved. <P>SOLUTION: The knock-out device includes body members 11, 13 fixed on a lower end of a slide 2, a guide hole 14 formed in the annular body member 13, the movable pad 16 fitted in the guide hole 14 so as to move up and down, a hydraulic cylinder 17 formed with the annular body member 13 and the movable pad 16, capable of driving the movable pad 16 to move down, and a plurality of spring mechanisms for elastically urging the movable pad 16 upward to an upper limit position. The outer peripheral face of the movable pad 16 is formed in a square cylindrical face 16a in an equilateral octagonal cross section, having each ridge part and neighboring parts to be formed into a partial cylindrical face. At least two partial cylindrical faces are constantly brought into slide contact with the inner peripheral face of the guide hole 6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a knockout device for driving an upper die unit for punching a printed circuit board that is mounted on the lower end of a slide of a press machine, and in particular, it can reduce frictional resistance acting on a movable pad and reduce wear and backlash of the movable pad. It relates to what was made.

  2. Description of the Related Art Conventionally, a hydraulic cylinder for holding and knocking out a printed circuit board (cushion hydraulic cylinder) is also incorporated in a printed circuit board punching apparatus for punching a large number of pin holes in a printed circuit board for forming an electric circuit. Further, various die forming apparatuses for producing a molded product by forming a metal plate (work) with a press machine are equipped with a hydraulic die cushion device (hydraulic cushion).

  As described in Patent Documents 1 and 2, generally, a printed circuit board punching apparatus includes a knockout device attached to a lower end of a slide of a press machine, and an upper die for punching attached to a lower end of the knockout device. A unit and a lower die unit for punching that is mounted on a base (bolster) of a press machine so as to face the upper die unit are provided.

  The knockout device is provided in the main body member fixed to the lower end of the slide, a guide hole recessed in the lower portion of the main body member, a movable pad mounted so as to be movable up and down in the guide hole, and an upper side of the movable pad. And a hydraulic cylinder for holding and knocking out (corresponding to a cushion hydraulic cylinder) formed on the movable pad, a plurality of spring mechanisms for elastically urging the movable pad to the upper limit position, and hydraulic pressure for supplying hydraulic pressure to the hydraulic cylinder A supply means;

  The upper die unit is a presser plate that can be raised and lowered to hold the upper surface of the printed circuit board, a number of punching pins and pin holding plates that are inserted through the presser plate, and a pressure transmission mechanism that transmits the pressing force from the movable pad to the presser plate. And a pressing force transmission mechanism for transmitting the pressing force from the main body member to the pin holding plate.

When a printed circuit board is punched by this printed circuit board punching device, the slide is lowered with hydraulic pressure supplied to the hydraulic cylinder and the movable pad at the lower limit position. Immediately thereafter, the printed circuit board is punched by a large number of punching pins that are driven downward by the slide at the bottom dead center of the slide.
Recently, there is a tendency to mount a large number of miniaturized electronic components on a printed circuit board at a high density, the pin holes and pin hole intervals of the printed circuit board are reduced, the number of pin holes is increased, the printed circuit board is thinner, Since there is a tendency to increase the number of layers, a higher level of punching performance is required.

Japanese Utility Model Publication No. 2-118623 Japanese Utility Model Publication No. 3-76622

  The movable pad is accommodated in a circular guide hole of the main body member so as to be movable up and down, and the cylindrical outer peripheral surface of the movable pad is in sliding contact with the inner peripheral surface of the cylindrical guide hole of the main body member. In order for the movable pad to be able to move up and down within the guide hole, a minute gap is required between the outer peripheral surface of the movable pad and the inner peripheral surface of the guide hole. Therefore, the outer peripheral surface of the movable pad and the inner peripheral surface of the guide hole are likely to be in line contact with each other of the cylindrical surface, and when the line contact occurs, wear of the outer peripheral surface of the movable pad and the inner peripheral surface of the guide hole is likely to proceed. Moreover, the frictional force acting on the movable pad tends to increase.

  Since the number of pin holes formed in the printed circuit board is not uniform over the entire surface of the printed circuit board, wear of the outer peripheral surface of the movable pad and the inner peripheral surface of the guide hole proceeds as described above, and the movable pad When the frictional force acting on the surface increases, there are many cases in which a large number of pin holes are punched out while the movable pad is inclined at a minute angle with respect to the horizontal plane. As a result, the processing accuracy of the pin holes is deteriorated, the quality of the printed circuit board is lowered, the load acting on the punching pins is increased, and the durability is lowered.

  An object of the present invention is to reduce frictional force acting on a movable pad, wear on the outer peripheral surface of the movable pad and the inner peripheral surface of the guide hole, and the movable pad in a knockout device for driving an upper die unit for punching a printed circuit board. This makes it possible to reduce the backlash of the printed circuit board, and enhances the printed board punching performance.

  The knockout device according to claim 1 is a knockout device that is attached to a lower end of a slide of a press machine and drives an upper die unit for punching a printed circuit board that is attached to the slide, and a main body member fixed to the lower end of the slide; The main body member has a circular guide hole that is recessed from the lower end thereof, a thick plate-like movable pad that is mounted in the guide hole so as to be movable up and down, and the movable pad formed on the main body member and the movable pad. A hydraulic cylinder that can be driven downward, and a plurality of spring mechanisms that elastically urge the movable pad to the upper limit position with respect to the main body member, and the outer peripheral surface of the movable pad is a square cylinder surface having a regular polygonal cross section. Each ridge line portion and its vicinity are formed on a rectangular cylindrical surface forming a partial cylindrical surface, and at least two of the partial cylindrical surfaces are always in sliding contact with the inner peripheral surface of the guide hole. It is characterized in that the.

  The knockout device according to claim 2 is a knockout device that is attached to a lower end of a slide of a press machine and drives an upper die unit for punching a printed circuit board that is attached to the slide, and a main body member fixed to the lower end of the slide; A guide hole that is recessed from the lower end of the main body member, a thick plate-shaped movable pad that is mounted in the guide hole so as to be movable up and down, and is formed by the main body member and the movable pad. A hydraulic cylinder that can be driven downward, and a plurality of spring mechanisms that elastically urge the movable pad to the upper limit position with respect to the main body member, and the inner peripheral surface of the guide hole is a square tube surface having a regular polygonal cross section And formed in a rectangular tube surface having a plurality of partial cylindrical surfaces having a radius of curvature equal to or larger than the radius of curvature of the outer peripheral surface of the movable pad at a portion other than the ridge line portion and the vicinity thereof. It is one in which at all times at least two partially cylindrical surfaces, characterized by being configured so as to sliding contact with the outer peripheral surface of the movable pad.

  A knockout device according to a third aspect is the invention according to the first or second aspect, wherein the regular polygon is a regular n-gon (where n is an integer of 6 to 8). is there.

  According to the first aspect of the present invention, the outer peripheral surface of the movable pad is a rectangular tube surface having a regular polygonal cross section, and each ridge line portion and its vicinity are formed into a rectangular tube surface forming a partial cylindrical surface, and are always at least Since the two partial cylindrical surfaces are configured to be in sliding contact with the inner peripheral surface of the guide hole, when the movable pad repeatedly moves up and down repeatedly by punching the printed circuit board, it acts between the movable pad and the inner peripheral surface of the guide hole. The frictional force is reduced, the wear of the inner surface of the movable pad and the guide hole is reduced, the play of the movable pad is reduced, and the movable pad is hardly inclined from the horizontal posture. Therefore, the printed circuit board punching performance can be improved, the quality of the printed circuit board can be improved, and the durability of the knockout device and the upper unit for printed circuit board punching can be increased.

  According to the invention of claim 2, the inner peripheral surface of the guide hole is a square tube surface having a regular polygonal cross section, and is equal to the radius of curvature of the outer peripheral surface of the movable pad at a portion other than the ridge line portion and the vicinity thereof. Or formed on a rectangular tube surface having a plurality of partial cylindrical surfaces with a larger radius of curvature, and at least two partial cylindrical surfaces are always in sliding contact with the outer peripheral surface of the movable pad. When the movable pad repeatedly moves up and down, the frictional force acting between the movable pad and the inner peripheral surface of the guide hole is reduced, wear on the inner peripheral surface of the movable pad and the guide hole is reduced, and rattling of the movable pad is reduced. The movable pad hardly tilts from the horizontal posture. Therefore, the printed circuit board punching performance can be improved, the quality of the printed circuit board can be improved, and the durability of the knockout device and the upper mold unit for printed circuit board punching can be increased.

  According to the invention of claim 3, since the regular polygon is a regular n-gon (where n is an integer of 6 to 8), it always slides on the inner peripheral surface of the guide hole or the outer peripheral surface of the movable pad. Since the distance between the at least two partial cylindrical surfaces in contact with each other does not become excessive, the intended purpose can be achieved.

It is sectional drawing of the printed circuit board punching apparatus of Example 1 of this invention. It is sectional drawing of a knockout apparatus. It is a perspective view of a movable pad and a spring mechanism of the knockout device. It is the IV-IV sectional view taken on the line of FIG. It is a hydraulic circuit diagram of a drive unit. It is a time chart which shows opening and closing of an electromagnetic direction switching valve. FIG. 6 is a diagram corresponding to FIG. 4 of the second embodiment.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to examples.

  The printed circuit board punching apparatus 1 is for punching a large number of pin holes in the printed circuit board P. As shown in FIG. 1, a printed circuit board punching device 1 includes a knockout device 10 attached to the lower end of a slide 2 of a crank press machine, an upper mold unit 30 attached to the lower end of the knockout device 10, The lower die unit 50 mounted on the upper surface of the base 3 (bolster) of the press machine so as to face the lower side of the die unit 30 and the drive unit 70 for supplying hydraulic pressure to the holding and knockout hydraulic cylinder 17 of the knockout device 10. It has.

First, the knockout device 10 will be described.
As shown in FIGS. 1 and 2, the knockout device 10 is a rectangular thick plate-shaped main body member 11 fixed to the lower end surface of the slide 2 with a plurality of bolts and the like, and is recessed in the central portion of the lower portion of the main body member 11. An annular main body member 13 that is fitted into the housing hole 12 in an inner fitting shape and is fixed to the main body member 11 with a plurality of bolts 4 (see FIG. 4). The movable pad 16 is mounted in a vertically-facing cylindrical guide hole 14 formed so as to be movable up and down, and is provided with a piston member 20 at the center of the movable pad 16 so as to apply hydraulic pressure to the movable pad 16. The cylinder 17 (cushion hydraulic cylinder) and six sets of spring mechanisms 18 (see FIGS. 2 and 3) for elastically urging the movable pad 16 to the upper limit position by the elastic force of the compression coil spring 19 are provided. The main body member 11 and the annular main body member 13 correspond to the “main body member” recited in the claims, but they may be integrally formed.

  The hydraulic cylinder 17 includes a cylinder hole 19 formed at the center of the movable pad 16 and a piston member 20 fixed to the main body member 11 with four bolts 21 and inserted into the cylinder hole 19. An oil chamber 22 (corresponding to a cushion oil chamber) of the hydraulic cylinder 17 is formed by the movable pad 16 and the piston member 20, and a seal 23 is attached to the outer peripheral portion of the cylinder hole 19. An oil passage 24 for supplying hydraulic pressure to the oil chamber 22 of the hydraulic cylinder 17 is formed in the piston member 20 and the main body member 11, and this oil passage 24 is connected to a drive unit 70 as a hydraulic pressure supply source described later (FIG. 5). reference).

  As shown in FIGS. 2 to 4, the outer peripheral surface of the movable pad 16 of the knockout device 10 is a square tube surface 16 a having a regular octagonal cross section, and each ridge line portion and its vicinity form a partial cylindrical surface 7. The cylindrical surface 16 a is formed so that at least two of the partial cylindrical surfaces 7 are always in sliding contact with the inner peripheral surface of the guide hole 6. The radius of curvature of the partial cylindrical surface 7 is formed to be equal to or smaller than the radius of curvature of the inner peripheral surface of the guide hole 6. In the rectangular tube surface 16 a, a space between adjacent partial cylindrical surfaces 7 is formed in a flat portion 5, and a thin gap 8 having an arcuate cross section is formed between each flat portion 5 and the inner peripheral surface of the guide hole 6. Is formed.

  As shown in FIG. 2, the spring mechanism 18 is fixed to the main body member 11 and inserted into the guide hole 25 of the movable pad 16 and a hooked case 26 having a cross-sectional hat shape, and the spring mechanism 18 is arranged at the center of the case 26. A bolt 27 and a spacer 28 that are provided and pass through the bottom wall of the case 26 and are fixed to the movable pad 16, and are mounted so as to surround the bolt 27 and the spacer 28 in the case 26, and the movable pad 16 is interposed via the bolt 27. And a compression spring 29 for urging the upper spring to an upper upper limit position. In a state where the hydraulic pressure of the hydraulic cylinder 17 is released, the movable pad 16 is returned to the upper limit position by the six sets of spring mechanisms 18.

  The upper die unit 30 is fixed to the lower surface of the main body member 11 by a plurality (e.g., eight) of hydraulic clamping devices 31, but a T for attaching the hydraulic clamping device 31 to the lower surface portion of the main body member 11. A groove 9 is formed.

Next, the upper mold unit 30 will be described.
As shown in FIG. 1, the upper mold unit 30 includes a base plate 32, a frame member 33, a movable plate 34 that can be moved up and down, a pin holding upper plate 35 and a pin holding lower plate 36, a frame-shaped die 37, and an inside thereof. The presser plate 38 can be moved up and down, fixed to the plurality of movable first rods 39, the plurality of movable second rods 40, the plurality of third rods 41, the pin holding upper plate 35 and the pin holding lower plate 36. A plurality of clamping devices 31 for fixing a large number of punching pins 43, four connecting bolts 44, and base plate 32 inserted into the numerous pin guide holes 42 of 38 to the main body member 11 of the knockout device 10. Etc.

  A first transmission system that transmits a pressing force acting on the movable pad 16 from the hydraulic cylinder 17 to the presser plate 38 includes a plurality of first rods 39, a movable plate 34, and a plurality of second rods 40. The second transmission system that transmits the downward driving force of the slide 2 and the main body member 11 to a large number of punching pins 43 includes a base plate 32, a plurality of third rods 41, and a pin holding upper plate 35.

Next, the lower mold unit 50 will be described.
As shown in FIG. 1, the lower mold unit 50 includes a base plate 52, a large number of die holes 53 corresponding to a large number of pins 43, and punches the remaining peripheral portion of the printed circuit board P in cooperation with the frame-shaped die 37. A lower die main body 54 that functions as a punch plate to be processed, a frame-shaped receiving plate 55 that is externally fitted to the lower die main body 54 so as to be movable up and down, four guide rods 56 that guide the frame-shaped receiving plate 55, and guide rods 56 A rubber member 57 or coil spring that is externally fitted and elastically supports the frame-shaped receiving plate 55 so as to be movable up and down, four connecting bolts 58 that connect the lower die main body 54 to the base plate 52, and the base plate 52 are the base 3 of the press machine. A plurality of clamping devices 51 and the like for fixing to the upper surface.

Next, the drive unit 70 of the knockout device 10 will be described.
The drive unit 70 supplies hydraulic pressure to the oil chamber 22 (corresponding to a cushion oil chamber) of the hydraulic cylinder 17 and relieves the hydraulic pressure of the oil chamber 22.
The drive unit 70 includes a hydraulic pressure supply section 71, a hydraulic pressure supply path 72 extending from the hydraulic pressure supply section 71 to the oil chamber 22 of the hydraulic cylinder 17, a relief oil path 73 connected to the oil chamber 22 of the hydraulic cylinder 17, and hydraulic pressure supply And a relief valve operating circuit 74 connected in parallel to the passage 72.

  The hydraulic pressure supply unit 71 includes an oil tank 75, a swash plate hydraulic pump 77 driven by an electric motor 76, a cooler 78 that cools the oil returned from the hydraulic cylinder 17, and a cooling device for cooling the cooler 78. A fan 79 driven by a motor 76, a check valve 80, and the like are provided. In the hydraulic pressure supply path 72, a pressure gauge 81, a check valve 82, a pressure reducing valve 83, an accumulator 84 for storing the hydraulic pressure of a knockout pressure, which will be described later, a pressure gauge 85, and an electromagnetic direction switch are sequentially provided from the hydraulic pressure supply section 71 side. A valve 86 is provided. The electromagnetic direction switching valve 86 includes a closing position for closing the oil passage, a supply position for supplying hydraulic pressure from the hydraulic pressure supply unit 71 to the oil chamber 22, and an oil tank for supplying the oil pressure of the oil chamber 22 via a discharge oil passage 97 described later. It can be switched to a discharge position for discharging to 75.

  One end of the relief oil path 73 is connected to the oil chamber 22 of the hydraulic cylinder 17 via the hydraulic pressure supply path 72, and the other end of the relief oil path 73 is connected to the oil tank 75. In the relief oil passage 73, a pressure gauge 90, a balance piston type relief valve 91, a buffer tank 92, and a cooling cooler 93 are provided in this order from the oil chamber 22 side.

  The relief valve operating circuit 74 is provided in the auxiliary hydraulic pressure supply path 94, the electromagnetic direction switching valve 95 provided in the auxiliary hydraulic pressure supply path 94, and the electromagnetic direction switching valve 95 in series with the auxiliary hydraulic pressure supply path 94. The variable throttle valve 96 is provided. A discharge oil passage 97 is connected to the electromagnetic direction switching valves 86 and 95.

  One end of the sub hydraulic pressure supply path 94 is connected to the oil chamber 22 of the hydraulic cylinder 17 via the hydraulic pressure supply path 72, and the other end of the sub hydraulic pressure supply path 94 supplies hydraulic pressure between the pressure gauge 81 and the check valve 82. It is connected to the path 72. The electromagnetic direction switching valve 95 is connected to a portion of the auxiliary hydraulic pressure supply path 94 closer to the hydraulic cylinder 17 than the variable throttle valve 96.

  One end side of the discharge oil passage 97 is connected to the electromagnetic direction switching valves 86 and 95, and the other end is connected to the oil tank 75. The electromagnetic direction switching valve 95 closes the sub-supply path 94, supplies a position for supplying hydraulic pressure to the oil chamber 22, and supplies the oil pressure in the oil chamber 22 and the supply oil path 72 to the oil tank 75 via the discharge oil path 97. It is possible to switch to a discharge position for discharging to.

The control device 98 receives the phase signal PS related to the lift position of the slide 2 from a control unit (not shown) that controls the press machine, and controls the electromagnetic direction switching valves 86 and 95.
As shown in FIG. 6, for example, the electromagnetic direction switching valve 86 is opened to the supply position so that the slide 2 knocks out the printed circuit board P at a predetermined time immediately before the top dead center, and is hydraulically supplied to the oil chamber 22. And the slide 2 is switched to the valve-closed state immediately after passing through the top dead center.

  The electromagnetic direction switching valve 95 is opened to the supply position in order to perform the relief operation of the relief valve 91 when the slide 2 is set at a position between the top dead center and the bottom dead center (for example, a crank angle position of 90 degrees). When 2 reaches bottom dead center, the valve is switched to the closed state. The above-mentioned setting position of the crank angle of 90 degrees is an example, and may be a position smaller than 90 degrees. Although the position may be larger than 90 degrees, it is necessary that the timing is earlier than the timing when the pressing plate 38 contacts the printed board P.

Next, the operation and effect of the printed board punching apparatus 1 will be described.
When the slide 2 is lowered to just before the bottom dead center in a state where the hydraulic pressure is supplied to the hydraulic cylinder 17, the presser plate 38 contacts and presses the printed board P. When the slide 2 reaches the set position between the top dead center and the bottom dead center, the electromagnetic direction switching valve 95 is opened to the supply position, so that a high pressure (this is not reduced by the pressure reducing valve 83 from that time) Is higher than the relief operating pressure of the relief valve 91) is supplied to the supply oil passage 72 and the oil chamber 22 of the hydraulic cylinder 17 at a small flow rate throttled by the variable throttle valve 96. Starts the relief operation and enters a relief state in which relief is performed in small flow rates.

  Thus, after the relief valve 91 starts the relief operation, the presser plate 38 presses the printed circuit board P when the slide 2 descends to just before the bottom dead center. Immediately after that, when the slide 2 reaches the bottom dead center, the relief valve 91 is fully relieved, and the slide 2 is lowered while the movable pad 16 moves to the upper limit position relative to the annular body member 13. The driving force is transmitted from the base plate 32, the third rod 41, and the pin holding upper plate 35 to a number of punching pins 43, and the printed circuit board P is punched.

  In this way, when the slide 2 reaches the set position between the top dead center and the bottom dead center, the electromagnetic direction switching valve 95 is switched to the supply position and the relief operation of the relief valve 91 is started. There is no response delay in the relief operation due to the stationary inertia of the relief valve element (not shown). Therefore, no surge pressure is generated in the oil pressure of the oil chamber 22 of the hydraulic cylinder 17, a good soft cushion performance by the hydraulic cylinder 17 can be secured, and the punching performance can be improved, and mechanical vibration and noise can be achieved. Can be reduced.

  Thereafter, when the electromagnetic directional control valve 86 is opened to the supply position by the control device 97 when the slide 2 reaches a predetermined position immediately before the top dead center, the movable pad 16 is driven to descend strongly, and the printed circuit board P is moved. A number of punching pins 43 are knocked out by the presser plate 38 and dropped onto a chute (not shown) inserted below the upper die unit 30 and taken out to the outside. In parallel with this, a printed board material (not shown) is put on the lower mold unit 50 and the chute is retracted, and the punching process similar to the above is repeatedly executed.

  The outer peripheral surface of the movable pad 16 is a rectangular tube surface 16a having a regular octagonal cross section, and each ridge line portion and its vicinity are formed on a rectangular tube surface 16a forming a partial cylindrical surface 7, and always at least two of the partial cylinders. The surface 7 is in sliding contact with the inner peripheral surface of the guide hole 6. Therefore, when the printed circuit board punching process is repeated and the movable pad 16 is repeatedly raised and lowered, the frictional force acting between the movable pad 16 and the inner peripheral surface of the guide hole 6 is reduced, and the inner peripheral surface of the movable pad 16 and the guide hole 6 is reduced. Wear is reduced, the backlash of the movable pad 16 is reduced, and the movable pad 16 is hardly inclined from the horizontal posture.

  Therefore, the printed circuit board punching performance can be improved, the quality of the printed circuit board can be improved, and the durability of the knockout device 10 and the upper mold unit 30 for printed circuit board punching can be increased. Since the outer peripheral surface 16a of the movable pad 16 is formed into a square cylinder surface 16a having a regular octagonal cross section, the interval between at least two partial cylindrical surfaces 7 that are always in sliding contact with the inner peripheral surface of the guide hole 6 does not become excessive. The intended purpose can be achieved.

  In the knockout device 10A of the second embodiment, the shape of the outer peripheral surface of the movable pad 16A and the shape of the inner peripheral surface of the guide hole 6A are changed as follows, and other configurations are the same as those of the first embodiment. .

  As shown in FIG. 7, the inner peripheral surface of the guide hole 6A is a square cylinder surface 6a having a regular octagonal cross section, and the radius of curvature of the outer peripheral surface of the movable pad 16A on the ridge line portion and the portion other than the ridgeline portion and the vicinity thereof. It is formed on a rectangular tube surface 6a having a plurality of partial cylindrical surfaces 15 having an equal or larger radius of curvature, and at least two partial cylindrical surfaces 15 are always in sliding contact with the outer peripheral surface of the movable pad 16A. A thin arcuate gap 8A is formed between each ridge line portion of the rectangular tube surface 6a and the vicinity thereof and the outer peripheral surface of the movable pad 16A.

Next, the operation and effect of the knockout device 10A will be described.
The inner peripheral surface of the guide hole 6A is a square cylinder surface 6a having a regular octagonal cross section, and the radius of curvature of the outer peripheral surface of the movable pad 16A is equal to or larger than that of the ridgeline portion and the vicinity thereof. It is formed on a rectangular tube surface 6a having a plurality of partial cylindrical surfaces 15, and at least two partial cylindrical surfaces 15 are always in sliding contact with the outer peripheral surface of the movable pad 16A. Therefore, when the movable pad 16A repeatedly moves up and down repeatedly by punching the printed circuit board, the frictional force acting between the movable pad 16A and the inner peripheral surface of the guide hole 6A is reduced, and the inner periphery of the movable pad 16A and the guide hole 6A is reduced. The surface wear is reduced, the backlash of the movable pad 16A is reduced, and the movable pad 16A hardly tilts from the horizontal posture.

  Therefore, the printed circuit board punching performance can be improved, the quality of the printed circuit board can be improved, and the durability of the knockout device 10A and the upper mold unit 30 for printed circuit board punching can be increased. Since the inner peripheral surface of the guide hole 6A is formed as a square cylinder surface 6a having a regular octagonal cross section, the distance between at least two partial cylindrical surfaces 15 that are always in sliding contact with the outer peripheral surface of the movable pad 16A is not excessive. Therefore, the intended purpose can be achieved.

Here, the example which changes the said Example partially is demonstrated.
1] As a modified example of the knockout device 10 of the first embodiment, the outer peripheral surface of the movable pad 16 is a rectangular tube surface having a regular hexagonal cross section, and each ridge line portion and its vicinity form a partial cylindrical surface. Alternatively, it may be formed on a square tube surface having a regular heptagonal cross section and each ridge line portion and its vicinity forming a partial cylindrical surface.

2] As a modified example of the knockout device 10A of the second embodiment, the inner peripheral surface of the guide hole 6A is a square cylinder surface having a regular hexagonal cross section, and the movable pad is disposed on a portion other than the ridge line portion and its vicinity. It may be formed on a square tube surface having a plurality of partial cylindrical surfaces having a radius of curvature equal to or larger than the outer peripheral surface, or a square tube surface having a regular heptagonal cross section and its ridgeline portion and its vicinity You may form in the square cylinder surface which has the some partial cylindrical surface which is equal to or larger than the curvature radius of the outer peripheral surface of the said movable pad in parts other than a part.

  In addition, those skilled in the art can implement the present invention by adding various modifications to the above-described embodiments, and the present invention includes such modifications.

  It is a knockout device that drives an upper die unit for punching a printed circuit board that is mounted on the lower end of a slide of a press machine, and can improve the performance of punching a printed circuit board of various sizes, thereby improving the quality of the printed circuit board.

DESCRIPTION OF SYMBOLS 1 Printed circuit board punching processing apparatus 2 Slide 5 Plane part 6, 6A Guide hole
6a Square cylindrical surface 7 Partial cylindrical surface 10 Knockout device 11 Main body member 13 Annular main body member 14 Guide hole 15 Partial cylindrical surface 16, 16A Movable pad 16a Square cylindrical surface 17 Hydraulic cylinder 18 Spring mechanism

Claims (3)

In a knockout device that is attached to the lower end of a slide of a press machine and drives an upper die unit for printed circuit board punching that is attached to the slide,
A body member fixed to the lower end of the slide;
A bottom-view circular guide hole recessed from the lower end of the main body member,
A thick plate-like movable pad mounted in this guide hole so as to be movable up and down,
A hydraulic cylinder formed on the main body member and the movable pad and capable of driving the movable pad downward; and a plurality of spring mechanisms for elastically biasing the movable pad to the upper limit position with respect to the main body member;
An outer peripheral surface of the movable pad is a rectangular tube surface having a regular polygonal cross section, and each ridge line portion and a vicinity thereof form a partial cylindrical surface, and at least two partial cylindrical surfaces are always the guide. A knockout device configured to be in sliding contact with an inner peripheral surface of a hole. In a knockout device that is attached to the lower end of a slide of a press machine and drives an upper die unit for printed circuit board punching that is attached to the slide,
A body member fixed to the lower end of the slide;
A guide hole recessed from the lower end of the main body member;
A thick plate-like movable pad that is mounted in the guide hole so as to be movable up and down, and is circular in a bottom view
A hydraulic cylinder formed on the main body member and the movable pad and capable of driving the movable pad downward; and a plurality of spring mechanisms for elastically biasing the movable pad to the upper limit position with respect to the main body member;
An inner peripheral surface of the guide hole is a rectangular tube surface having a regular polygonal cross section, and a plurality of curvature radii equal to or larger than the radius of curvature of the outer peripheral surface of the movable pad at a portion other than the ridge line portion and the vicinity thereof. A knockout device, wherein the knockout device is formed on a rectangular tube surface having a partial cylindrical surface, and at least two partial cylindrical surfaces are always in sliding contact with the outer peripheral surface of the movable pad.   The knockout device according to claim 1 or 2, wherein the regular polygon is a regular n-gon (where n is an integer of 6 to 8).