JP4812718B2 - Mold for cam device and press machine - Google Patents

Description

  The present invention relates to a cam device used for a die or the like of a press machine and a die for a press machine provided with the cam device.

JP 2002-137026 A JP-A-10-128465 JP 2001-286950 A JP-A-5-192721 JP 2005-144493 A Japanese Patent No. 3810269

  In a press machine, a workpiece that is generally placed horizontally between an upper punch attached to a slide and a lower die attached to a bolster by a vertical movement of the slide, and a punch that descends downward, etc. Drill holes with a tool. That is, the moving direction of the tool (machining direction) and the moving direction of the slide (pressing direction) are the same. On the other hand, when the part of the workpiece to be drilled is tilted or drilled in the horizontal direction, a die using a cam mechanism is used to drive the punch in a tilted or lateral direction with respect to the workpiece. In other words, the driven cam provided with a tool such as a punch is guided to move in the machining direction, and the vertical movement of the slide is converted into the movement of the driven cam in the machining direction by sliding between the inclined surfaces of the drive cam and the driven cam. And process.

  As such a cam mechanism, for example, there is a press die cam disclosed in Patent Document 1. This cam mechanism engages with a cam slide (driven cam) that is slidably supported in a horizontal direction by a base fixed to a lower mold, and an inclined surface formed on the cam slide to move the cam slide in the horizontal direction. It consists of a driving cam driver (driving cam). In Patent Document 1, the inclined surface is about 45 °. However, when the molding load is high, the inclined surface is often about 60 ° with respect to the horizontal surface for the purpose of reducing the sliding surface pressure. A tool such as a punch is fixed to the front end of the cam slide, and the punch is reciprocated laterally with respect to the die fixed to the lower die and lowered. In this device, the vertical movement of the slide of the press machine is converted into a lateral movement of the tool using a cam mechanism.

  While the cam mechanism is operating, even if the slide moves up and down, the cam slider only moves horizontally and does not move up and down. In Patent Document 1, a press die using such a cam mechanism is used for both a stationary type in which the entire cam driver and cam slide are incorporated in the lower die and a suspension type in which the cam die is incorporated in the upper die. Is described.

  On the other hand, in Patent Document 2, a cam base having a slide rail that is gently inclined on an upper mold is fixed, a passive cam having a punch attached to the slide rail is slidably provided, and a cam that engages the passive cam on the lower mold A press-type cam structure in which a fixed cam having a surface is fixed is described. Patent Document 2 proposes machining with three punches having different angles by engaging three passive cams with a fixed cam having three types of cam surfaces.

  Patent Document 3 proposes a cam unit that converts a vertical movement of a slide into a pressing force of a punch at a desired angle by a fan-shaped arc cam. Patent Document 4 proposes a mold including a suspension cam in which a part of the fixed cam in Patent Document 2 is provided on the upper mold. Since this suspension cam is on the upper die side when the slide is raised, it does not interfere with the loading and unloading of the workpiece, and in the vicinity of the bottom dead center of the press, the horizontal projection is moved by the positioning protrusion installed on the lower die. Restrained and performs the same function as a fixed cam. Patent Document 5 proposes a double-acting cam type in which the cam mechanism for horizontally moving the punch of Patent Document 1 and the cam structure for moving the punch of Patent Document 2 obliquely are combined.

  On the other hand, the present applicant has proposed in Patent Document 6 that a sliding structure between a slider of a press machine and a frame giving is provided with a guide structure having no clearance using a spherical shoe. The spherical shoe has a convex lens shape with one surface being spherical and the other surface being flat. It also discloses that a liner made of a Teflon (registered trademark) -impregnated porous bimetal or the like is provided on a gib that slides on a flat surface of a spherical shoe.

  In a cam device used in a press machine, an operating cam (drive cam) and a driven cam slide on an engagement surface under a certain load (Patent Documents 1, 2, etc.). The load applied to the engagement surface includes the frictional force of the driven cam and the urging force of the return spring to be restored, but the reaction force during processing is the largest. Normally, the engagement surfaces of the actuating cam and the follower cam are slid in a static state. Therefore, when the load is actually applied (molded), each cam causes elastic deformation, Instead, it becomes a line contact. Therefore, oil shortage may occur and seizure may occur on the engagement surface. Further, when this elastic deformation occurs, the cam is not uniformly deformed, so that the cam is also in line contact with the guide surface and cannot move with high accuracy. Further, when the actuating cam is cantilevered, the elastic deformation becomes large, and the load greatly fluctuates during processing, so the elastically deformed shape also fluctuates.

  In order to prevent the above-mentioned problems such as seizure, the conventional cam device has a low contact surface pressure on the cam engagement surface or a liner having a low friction coefficient. However, the elastic deformation of the cam still cannot be suppressed. . For this reason, in order to accurately slide the engagement surfaces, it is necessary to increase the accuracy of the parts and to be adjusted by a skilled worker. In addition, when performing shearing with a small clearance between the punch and the die using the cam device as described above, since the movement of the driven cam is unstable, the punch guide portion is provided in the mold ( Patent Document 3) Since the cam motion is unstable, the wear of the punch and the punch guide portion becomes fast, and the shear surface length tends to become unstable. In addition, although two cam mechanisms having inclined surfaces reverse to each other are combined to reduce elastic deformation (Patent Document 5), seizure cannot be sufficiently prevented.

  In addition, when performing molding that requires a high molding load using a mold that uses a cam device, the cam width is generally increased to increase the area on the driven cam side (the area of the surface that receives the molding force) as described above. In many cases, the inclination angle (angle with respect to the horizontal plane) is set to about 60 °. In this case, the cam device has a longer stroke required for molding, and the cam device becomes larger. Therefore, it is difficult to arrange the cam device in the work space (die space) of the press machine. In addition, it is difficult to always make the cam engagement surface in surface contact when a high molding load is applied. Further, when the cam inclination angle (engagement side inclination angle) is decreased or increased to approximately 60 °, the area of the engagement surface increases to about twice that of a right angle. When the contact area of the engagement surface increases, the mechanical loss due to friction increases, so the force pushing the cam increases.

  The present invention utilizes the technique of a spherical shoe (spherical shoe) adopted in the sliding mechanism between the slide and the gib in Patent Document 6, and even if the cam motion is unstable, the cam is elastically deformed. In addition, it is a technical problem to provide a cam device and a press machine die that can prevent the occurrence of line contact on the cam engagement surface and prevent damage and wear due to seizure. Further, the present invention reduces the frictional mechanical loss in molding that requires a high molding load by reducing the frictional force of the cam engagement surface and reducing the cam inclination angle to approximately 45 °. The second technical problem is to reduce the work space (die space).

  The cam device of the present invention (Claim 1) is provided movably in the pressurizing direction, and provided with a drive cam having an inclined surface having a predetermined inclination angle with respect to the pressurizing direction, and movably in the machining direction. And a driven cam provided with an inclined surface having an inclination angle corresponding to the inclined surface of the drive cam, and force and movement in the pressurizing direction by relative movement through the inclined surface of the drive cam and the driven cam. Is converted into force and motion in the machining direction, and either one of the drive cam or the follower cam is formed with a spherical shallow concave portion on one inclined surface, and one surface is formed in the concave portion. Is a convex surface that is complementary to the spherical surface of the concave portion and has a somewhat larger convex surface, and a convex lens-like spherical shoe whose other surface is a flat surface protruding from the inclined surface so that the convex surface slides into contact with the spherical surface of the concave portion. It is characterized by being freely accommodated It is set to.

  In such a cam device, it is preferable that the spherical shallow concave portion is formed on the inclined surface of the drive cam.

  A mold for a press machine according to the present invention (Claim 3) includes at least one of the cam devices described above, and a tool for processing is provided on the driven cam. In such a die for a press machine, it is preferable that a plurality of the cam devices are provided so that lateral forces are balanced.

  In the cam device of the present invention (Claim 1), when the drive cam or the driven cam is elastically deformed and a minute angle is formed between the inclined surfaces, or because the accuracy of parts and the accuracy of the sliding are low, it is originally. When both inclined surfaces have a minute angle, the spherical shoe swings and absorbs the minute angle. Thereby, the surface contact between the flat surface of the spherical shoe and the inclined surface of any one of the cams with which the flat surface abuts is maintained. Further, the convex spherical surface of the spherical shoe and the spherical surface of the concave portion with which the convex spherical surface is fitted are always in surface contact with each other even if the angle changes. Accordingly, surface contact is maintained on any sliding surface, and seizure and great wear do not occur.

  In such a cam device, when the shallow spherical concave portion is formed on the inclined surface of the drive cam (claim 2), the configuration of the driven cam does not become complicated. That is, the driven cam has an inclined surface on which the flat surface of the spherical shoe slides, and a guide surface for moving in the machining direction, and tends to be complicated because a machining tool is attached. By providing a spherical shoe on the drive cam side, further complication can be avoided.

  Since the metal mold for a press machine according to the present invention (Claim 3) is provided with the cam device described above, it is possible to obtain the operational effects of the cam device.

  In such a die for a press machine, when a plurality of cam dies are provided so that the lateral force is balanced (Claim 4), the lateral force applied to the die is balanced, The amount of elastic deformation of the cam is also balanced. As a result, the processing accuracy is increased and the burden due to the eccentric load on the press machine is reduced.

  Next, an embodiment of a cam device and a mold according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part showing an embodiment of a cam device of the present invention, FIG. 2 is a cross-sectional view of an essential part showing an operating state thereof, and FIG. 3b is a front view showing the inclined surface of FIG. 3a, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, FIG. 5 is a partially cutaway perspective view of the mold of FIG. FIG. 7 is a bottom view showing the upper mold of the mold, and FIG. 8 is a view of the mold equipped with the cam device of the present invention. FIG. 9A is a plan view before and after forming a workpiece formed by the mold of FIG. 8, and FIG. 9B is a front view before and after forming the workpiece.

  A cam device 10 shown in FIG. 1 includes a drive cam (operating cam) 12 fixed to an upper plate 11 and a driven cam 14 provided slidably with respect to a lower plate 13. An inclined surface 15 is formed on the lower surface of the drive cam 12, and an inclined surface 16 is formed between the back surface (left side in FIG. 1) and the upper surface of the driven cam 14 so as to face the inclined surface 15 of the drive cam 12. Has been. A spherical concave portion 17 is formed on the inclined surface 15 of the drive cam 12, and a spherical shoe 18 is fitted in the concave portion 17. In the spherical shoe 18, a portion 19 entering the concave portion 17 protrudes in a spherical shape, and the other surface 20 is flat. The spherical shoe 18 is thicker than the depth of the recess 17, so that when the portion 19 protruding into the recess 17 is accommodated, the flat surface 20 protrudes from the inclined surface 15.

  A liner 21 having a low friction coefficient and withstanding high surface pressure is attached to the inclined surface 16 of the driven cam 14. The liner 21 is preferably a Teflon (registered trademark) -impregnated porous bimetal. Between the inclined surface 15 of the drive cam 12 and the inclined surface 16 of the driven cam 14, there is a gap 22 having a dimension obtained by combining the protrusion of the spherical shoe 18 and the thickness of the liner 21. Further, in this embodiment, the same liner 23 as the above-described liner 21 is provided on the surface of the lower plate 13 on which the driven cam 14 slides.

  In the cam device 10 of FIG. 1, a back block (operating cam holder) 25 that slidably guides the back surface 24 of the drive cam 12 is provided on the top surface of the lower plate 13. The back block 25 resists the bending force that the drive cam 12 receives from the driven cam 14 and has the effect of reducing bending. As shown in FIG. 4, the back block 25 is fixed to the end face of the side block 26 with screws 27. A backup member 28 for backing up the back block 25 is in contact with the back side of the back block 25. The backup member 28 is fitted in a deep hole 29 formed in the lower plate 13 and is fixed to the lower plate 13 with screws 30.

  The cam device 10 constitutes a cam type as a whole together with the right side drilling tool (punch and die) in FIG. That is, the base portion 36 of the punch 35 is fixed to the end surface 34 (surface opposite to the inclined surface 16, right side in FIG. 1) 34 of the driven cam 14 by the punch holder 37. A cover 39 that engages with a step portion 38 of the punch 35 is screwed into the punch holder 37. A punch guide 40 that slidably guides the punch 35 is fixed to the lower plate 13. A die 41 is provided between the punch guide 40 and a gap through which the workpiece W is inserted. The die 41 is fixed to the lower plate 13, and a through hole 42 into which the punch 35 is inserted is formed sideways. The die 41 is formed with a scrap discharge hole 43 for discharging the chips.

  A space 44 is provided in the lower portion of the die 41 of the upper plate 13, and a knockout 45 for extracting the workpiece W from the die 41 is accommodated in the space 44 so as to be movable up and down. The upper surface of the knockout 45 receives a knockout pin 46 that passes through the die 41. The knockout 45 is driven upward by a predetermined work removal timing by an air cylinder or the like.

  As shown in FIG. 2, a prismatic spring receiver 47 projects from the side surface of the driven cam 14, and the driven cam 14 is placed between the spring receiver 47 and the end surface of the driven cam holder 48 fixed to the lower plate 13. A spring mechanism 50 for biasing to the return side (left side in FIG. 2) is interposed. In this embodiment, the spring mechanism 50 includes a cylindrical spring body 51 made of rubber such as urethane rubber, an end plate 53 fitted from one end side to the center hole 52 of the spring body 51, and fitted from the other end side. And a screw 55 whose head is engaged with the guide member 54 and whose tip is screwed to the end plate 53.

  The mold 56 provided with the cam device 10 configured as described above is used with the lower plate 13 attached to a bolster (reference numeral 57 in FIG. 3) of the press machine and the upper plate 11 attached to a slide 58 of the press machine. The drive cam 12 is not fixed to the upper plate 11, and the upper plate 11 abuts against the upper surface of the drive cam 12 as shown in FIG. 1 while the slide is lowered, and the drive cam 12 is lowered as it is as shown in FIG. . In other words, the mold 56 is a mold belonging to a so-called tacho mold. In addition, the cam type belongs to the stand type. However, it is good also as a hanging type | mold which fixes the upper plate 11 to the slide 58 like the metal mold | die 70 of FIG. In that case, except for the periphery of the die 41, the driven cam 14 is suspended from the upper plate 11 and the driven cam 14 is slidably connected to the drive cam 12.

  In the cam device 10 of FIG. 1, when the drive cam 12 is lowered, the inclined surface 16 of the driven cam 14 is pressurized by the flat surface 20 of the spherical shoe 18 via the liner 21, and the driven cam 14 is moved as shown in FIG. Slide in the horizontal direction (arrow P direction). Thereby, the punch 35 punches the workpiece W. The reaction force received by the driven cam 14 during drilling is received by the spherical shoe 18 and the lower plate 13 through the liners 21 and 23. The reaction force received by the spherical shoe 18 is received by the drive cam 12 through the spherical concave surface of the concave portion 17, a part thereof is received by the back block 25, and the rest is received by the slide of the press machine via the upper plate 11.

  When pressurization is started in the lateral direction of the driven cam 14 by the drive cam 12, a leftward force in FIG. 1 is applied to the lower end (tip) side of the drive cam 12. In particular, when the punch 35 punches the workpiece W, a strong leftward force is applied. The leftward force applied to the drive cam 12 at that time is received by the back block 25, and bending is suppressed. Furthermore, the inclined surface 15 of the drive cam 12 and the inclined surface 16 of the driven cam 14 are not parallel due to the bending, and some angle is generated, but the spherical shoe 18 rotates in the recess 17 to absorb the difference in angle. That is, even when the lower end of the drive cam 12 bends to the left and the angle of the inclined surface 15 of the drive cam 12 with respect to the horizontal plane becomes small, the spherical shoe 18 rotates slightly counterclockwise and the flat surface 20 of the flat surface 20 with respect to the horizontal plane The angle matches the angle of the inclined surface 16 of the driven cam 14. As a result, the surface contact is maintained while the inclined surface 16 of the driven cam 14 and the flat surface 20 of the spherical shoe 18 are in sliding contact with each other, and oil shortage and wear due to line contact and seizure due to them are prevented.

  Furthermore, in this embodiment, since the liner 21 is provided on the inclined surface 16 of the driven cam 14, seizure and wear are further prevented. Even when the driven cam 14 is bent so that the upper end thereof moves to the left side by the reaction force at the time of drilling, surface contact is maintained in the same manner as described above. The sliding contact between the spherical surface of the spherical shoe 18 and the concave portion 17 of the driving cam 12 is a sliding contact between the spherical surfaces. Therefore, even if the driving cam 12 and the driven cam 14 are bent, the surface contact is maintained. Oil shortage and seizure do not occur.

  As shown in FIG. 2, when the drive cam 12 descends to the lower end and the driven cam 14 moves to the right side, the spring receiver 47 integral with the driven cam 14 pressurizes the spring mechanism 50 in the axial direction, and the spring body 51 Compressed. That is, the drive cam 12 slides the driven cam 14 to the right while resisting not only the processing force but also the biasing force of the spring mechanism 50. Then, as the slide 58 of the press machine rises, the driven cam 14 moves to the left side by the biasing force of the spring mechanism 50 and returns to the original position. When the leftward force applied to the drive cam 12 is weakened and the bending is lost, the spherical shoe 18 returns to the original angular position. For this reason, the surface contact between the spherical shoe 18 and the driven cam 14 is maintained during the entire process.

  Next, an embodiment of the mold of the present invention will be described with reference to FIGS. A mold 56 shown in FIG. 3A includes two cam devices 10 symmetrically about a cylindrical die 41 as a center. The mold 60 is formed by placing a bottomed cylindrical workpiece upside down on a die 41 and punching with a punch 35 from the left and right. Therefore, as shown in FIG. 4, left and right rear blocks 25, 25 are symmetrically arranged on the lower plate 13, and front and rear side blocks 26, 26 are interposed therebetween. The side blocks 26 and 26 are also symmetrically arranged in the front-rear direction with the die 41 as the center. The lower plate 13, the left and right rear blocks 25, and the front and rear side blocks 26 are coupled in a box shape (see FIG. 5). A driven cam holder 48 having the same thickness as the spring receiver 47 is fixed to the inner surface side of the side block 26.

  In this mold 56, as shown in FIG. 4, the back surface 24 of the drive cam 12 protrudes in an arc shape in plan view, and the back block 25 is recessed in an arc shape so as to slide on the arc-shaped back surface 24. is doing. Further, the front side of the drive cam 12 also projects in an arc shape. Therefore, the drive cam 12 can rotate along the recessed cylindrical surface 25a of the back block 25, and no force in the twisting direction is applied. Further, even if some twisting deformation occurs in the drive cam 12, it is absorbed by the swing of the spherical shoe 18. However, the sliding surface of the back block 25 may be a flat surface.

  On the other hand, the side surface of the drive cam 12 is a flat surface to avoid interference with the spring receiver 47 of the driven cam 14. In this embodiment, it is configured to slide with the spring receiver 47. As shown in FIG. 3b, the driven cam 14 is substantially rectangular in plan view, and has a hexagonal columnar shape with the rear and side corners 61 chamfered. The liner 21 also has a substantially similar hexagon. The side surface of the driven cam 14 is slidably guided by the inner surface of the driven cam holder 48.

  Since the back side of the driven cam 14 is flat and the inner surface of the back block 25 is arcuate, there is a gap between the back side of the driven cam 14 and the inner surface of the back block 25.

  Further, in this mold 56, a work presser 64 is suspended from the lower surface of the central portion of the upper plate 11. The work retainer 64 includes a suspension rod 66 having a head 65 having an enlarged diameter, a ring member 67 that slidably guides the suspension rod to suspend the head 65, and a lower end of the suspension rod 66. It consists of a fixed disc-shaped pressing plate 68 and a cylindrical spring body 69 that is interposed between the pressing plate 68 and the ring member 67 and is provided around the suspension rod 66. The spring body 69 is a rubber member such as urethane rubber. However, a compression coil spring can also be used. The workpiece presser 64 functions to press and stabilize the workpiece W against the die 41 from when the drive cam 12 starts to pressurize the driven cam 14. Thereby, when the workpiece W is punched by the punch 35, the workpiece W does not tilt.

  In the above-described embodiment, the inclined surface where the driving cam and the driven cam are engaged is set at an angle of approximately 45 ° with respect to the horizontal plane. The punch 35 is configured to move in the horizontal direction, and the driven cam 14 also moves horizontally. However, the cam device and the mold according to the present invention are not limited to this, and the punch can be configured to move obliquely downward or obliquely upward. This also applies to the molds shown in FIGS. In these cases, the driven cam 14 is guided so as to reciprocate in the moving direction of the punch 35, that is, diagonally downward or diagonally upward. When the punch moves in an oblique direction, the inclined surface where the drive cam and the driven cam are engaged usually has a direction in which the axis of movement of the drive cam and the axis of movement of the driven cam are divided into two.

  When punching is performed by moving the punch diagonally downward, the angle of the inclined surface is 45 ° or less with respect to the horizontal plane, for example, about 20 to 40 ° (see Patent Document 2). On the other hand, when the punch moves obliquely upward, the angle of the inclined surface is 45 ° or more, for example, about 50 to 80 ° (see FIG. 9 of Patent Document 3). . Especially in the latter case, the surface pressure of sliding becomes high and the processing conditions become severe. However, by using a spherical shoe, sliding contact by surface contact is secured, so local stress increase on the sliding contact surface is eliminated. In addition, since the sliding resistance is reduced by the liners 21 and 23, processing is possible even under such severe conditions.

  In the above-described embodiment, an example of punching with a punch is shown, but bending, coining, drawing, and the like can be performed in the same manner. Moreover, although the said embodiment has shown the processing method which pressurizes inward from right and left with respect to a center workpiece | work, it can also process outward. 6 and 7 shows an embodiment of a mold used for processing in which punches 35 are radially expanded from the inner surface side of a cylindrical workpiece W to partially project the workpiece W outward. .

  The right side of FIG. 6 shows the state before the press machine reaches bottom dead center, and the left side shows the bottom dead center (end of molding) state of the press machine. As shown in FIG. 7, six cam devices 10 including the drive cam 12 and the driven cam 14 are arranged radially. In the cam device 10 of the mold 70, the drive cam 12 is substantially cylindrical, and the inclined surface at the lower end is an inclined surface 15 that rises outward, and a spherical shoe 18 is provided on the inclined surface 15. ing. The flat surface 20 of the spherical shoe 18 is outward. Further, each drive cam 12 is slidably fitted and guided in a guide hole 72 formed in the drive cam holder 71. In practice, the drive cam 12 is fixed to the upper plate 11, and the drive cam holder 71 is suspended from the upper plate 11 so as to be vertically movable. The central gas spring 73 urges the stripper plate 73a for removing the workpiece W from the punch downward.

  Further, a substantially disc-shaped driven cam holder 74 is fixed to the lower surface of the drive cam holder 71 by bolts (reference numeral 74a in FIG. 7). The follower cam holder 74 is radially formed with guide grooves 75 that support the follower cam 14 so as to be movable in the radial direction, and the bottom surface of the guide groove 75 is a liner 23 made of Teflon (registered trademark) -based impregnated porous bimetal or the like. Is pasted. The driven cam 14 has a substantially rectangular planar shape so as to move in the radial direction in the guide groove 75. And it chamfers so that a width | variety may become narrow in the center side, and is exhibiting hexagonal shape (refer FIG. 7). Further, the upper surface side of the driven cam 14 includes an inclined surface 16 that faces the inclined surface 15 of the drive cam 12.

  A fitting recess 76 for fitting and fixing the punch 35 is formed on the lower surface of the driven cam 14, and the inverted L-shaped punch 35 is fixed to the fitting recess 76 in a side view. On the inner side of the driven cam 14, a protrusion 77 that supports the inner surface side of the punch 35 extends downward. The upper surface on the outer side of the driven cam 14 is slidably in contact with the lower surface of the drive cam holder 71. In addition, the outer peripheral surface has a recess 78 that accommodates one end of the spring body of the spring mechanism 50. The outer end of the spring mechanism 50 is supported by a support block 79 fixed to the outer surface of the driven cam holder 74 as shown in FIG.

  As shown in FIG. 7, the width of the punch 35 is considerably narrower than that of the driven cam 14. A groove 80 for guiding the punch 35 is formed on the bottom surface of the guide groove 75 of the driven cam holder 74. As shown in FIG. 6, the groove 80 penetrates to the lower end. Thereby, the exchange of the punch 35 is easy.

  A stripper plate 73 a for pressing the workpiece W against the die 41 is fixed to the lower end of the rod of the gas spring 73. As described above, the driven cam holder 74 is fastened to the drive cam holder 71 with bolts. The drive cam 12, the drive cam holder 71, the driven cam 14, the driven cam holder 74, the punch 35, the gas spring 73, and the stripper plate 73a are all suspended from the upper plate 11 and constitute an upper mold.

  In this mold 70, the die 41 has a ring shape, the outer periphery is supported by a cylindrical first support 82, and the lower surface is supported by a cylindrical second support 83. The first support 82 supports an outward force applied to the die 41. On the upper surface of the first support 82, a ring 84 that engages with a step portion 41a formed on the outer periphery of the die 41 is fixed. The ring 84 functions as a stopper that comes into contact with the lower surface of the upper driven cam holder 74 and stops the driven cam holder 74 from descending.

  On the inner surface of the die 41, a counter punch 85 for pushing up the molded workpiece from the die is slidably accommodated. The counter punch 85 is biased upward by a biasing means such as a spring or an air cylinder (not shown). On the upper surface of the counter punch 85, a recess 85a is formed at the center in accordance with the shape of the workpiece W formed in the previous step. The lower part of the inner peripheral surface of the die 41 is also provided with a step part 41b that matches the shape of the workpiece W. A concave portion 41 c is formed at the upper portion of the inner peripheral surface so as to correspond to the tip of the punch 35. In this die 41, as shown in FIG. 7, concave portions 41c are formed at six locations.

  In the mold 70, at the top dead center of the press, the stripper plate 73a rises to the position of the imaginary line, and the work W rises to the vicinity of the upper surface of the die 41 by the biasing force of the counter punch 85. The operator takes out the processed workpiece W, places the next workpiece on the counter punch 85, and operates the press machine to process it. In some cases, the molded workpiece W is taken out and the next workpiece is inserted automatically by conveyance by the transfer device. Even when the driving cam 12 and the driven cam 14 are elastically deformed, the mold 70 is prevented from being seized because the flat surface 20 of the spherical shoe 18 and the inclined surface of the driven cam are in surface contact.

  In the embodiment of FIG. 1, the left and right driven cams 14 drive a punch for punching a thick plate that requires a high forming load. However, like the mold 86 shown in FIG. It is also possible to drive a punch 87 for forging a tooth profile that requires a high forming load. In addition, the right side of FIG. 8 is a state before processing, and the left side is a state after processing. According to this metal mold 86, the tooth-shaped recess 88 shown in FIGS. 10a and 10b can be formed on the side surface of the thick rectangular workpiece W shown in FIGS. 9a and 9b. The length of the workpiece W after forming is extended by plastic deformation.

  In the above embodiment, the drive cam is moved up and down, but it can also be moved in other directions such as the horizontal direction. In the above embodiment, the driving cam is provided with the spherical shoe, but the driven cam may be provided with the spherical shoe. In the above embodiment, the back surface of the drive cam is cylindrical and supported by a back block or drive cam holder having a recess on the cylindrical surface, but the back surface of the drive cam and the contact surface of the back block are planar. It can also be. In the embodiment of the mold, a plurality of cam devices are arranged symmetrically, but it is not always necessary to arrange them symmetrically. For example, the lateral forces of the plurality of cam devices are balanced. That is, the cam devices may be arranged so that the lateral force of each cam device is canceled out and the resultant force is zero. Further, an unbalanced arrangement can also be adopted, and for example, a mold having one cam device can be used. The mold is for a press machine, but can also be applied to a mold for performing other plastic working such as a header and a press brake.

It is principal part sectional drawing which shows one Embodiment of the cam apparatus of this invention. It is principal part sectional drawing which shows the operation state of the cam apparatus of FIG. 3a is a plan view showing an embodiment of a mold provided with the cam device of FIG. FIG. 3b is a front view showing an inclined surface of the follower cam of the mold. FIG. 4 is a cross-sectional view taken along line IV-IV of the mold of FIG. FIG. 4 is a partially cutaway perspective view of the mold of FIG. 3. It is principal part sectional drawing which shows other embodiment of the metal mold | die provided with the cam apparatus of this invention. It is a bottom view which shows the upper mold | type of the metal mold | die of FIG. It is a top view which shows other embodiment of the metal mold | die provided with the cam apparatus of this invention. FIG. 9A is a plan view before and after forming a workpiece formed by the mold of FIG. 8, and FIG. 9B is a front view before and after forming the workpiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cam apparatus 11 Upper plate 12 Drive cam 13 Lower plate 14 Drive cam 15 Inclined surface 16 Inclined surface 17 Recess 18 Spherical shoe 19 (Spherical protrusion) site | part 20 Flat surface 21 Liner 22 Gap 23 Liner 24 Back surface 25 Rear block 25a Cylindrical surface 26 Side Block 27 Screw 28 Backup Member 29 Deep Hole 30 Screw 34 End Face 35 Punch 36 Base 37 Punch Holder 38 Step 39 Cover 40 Punch Guide 41 Die 42 Through Hole 43 Scrap Discharge Port 44 Space 45 Knockout 46 Knockout Pin 47 Spring Bearing 48 Follower cam holder 50 Spring mechanism 51 Spring body 52 Center hole 53 End plate 54 Guide member 55 Screw 56 Die 57 Bolster 58 Slide 61 Corner part 64 Work holder 65 Head 66 Hanging rod 67 Ring member 68 Rate 69 Spring body 70 Mold 71 Driving cam holder 72 Guide hole 73 Gas spring 73a Stripper plate 74 Drive cam holder 74a Bolt 75 Guide groove 76 Fitting recess 77 Projection 78 Recess 79 Support block 80 Groove 82 First support 83 Second support 84 Ring 85 Counter punch 85a Concave part 86 Mold 87 Punch 88 Concave part

Claims (4)

A drive cam provided with an inclined surface that is movably provided in the pressing direction and has a predetermined inclination angle with respect to the pressing direction;
A driven cam provided with an inclined surface that is provided so as to be movable in a machining direction and has an inclined angle corresponding to the inclined surface of the drive cam;
A cam device that converts a force and a motion in a pressurizing direction into a force and a motion in a machining direction by a relative motion through the inclined surfaces of the drive cam and the driven cam,
A spherical shallow recess is formed on one of the inclined surfaces of the drive cam or the follower cam,
In the concave portion, a convex lens-like spherical shoe having one surface complementary to the spherical surface of the concave portion and a somewhat larger convex surface, and the other surface being a flat surface protruding from the inclined surface, the convex surface as the spherical surface of the concave portion. A cam device that is slidably accommodated in sliding contact.   The cam apparatus according to claim 1, wherein the spherical shallow concave portion is formed on an inclined surface of the drive cam.   A die for a press machine, comprising at least one cam device according to claim 1, wherein the driven cam is provided with a processing tool.   The die for a press machine according to claim 3, wherein a plurality of the cam devices are provided so that lateral forces are balanced.

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