Abstract: In a puncher, with respect to a cylindrical cover with a one-end opening hole, a piercing punch is loosely but not movably inserted. A tip end surface of the piercing punch is protruded out from the one-end opening hole of the cover. A cylindrical stripper provided between the cover and the piercing punch is provided detachably from the one-end opening hole. By a biasing member, the stripper is protruded out from the one-end opening hole more than the piercing punch does. When the stripper is pressed in against biasing force of the biasing member, the tip end surface of the piercing punch becomes to protrude out from a through-hole formed at a protruding end of the stripper. A removal-prevention member which prevents the stripper from removing from the cover is provided detachably with respect to the cover.

Abstract: A puncher is used when piercing a workpiece with a piercing punch while the workpiece is kept pressed by a stripper. The cover provided on the puncher is made of metal and a diameter of a cover portion at and near a tip end side is smaller than that of the other cover portion other than the cover portion. The other cover portion of the cover receives a biasing member. The cover portion at a tip end side gradually reduces its diameter toward the tip end to form a tapered portion. The puncher provides a long lifetime, guarantees sufficient pressing force onto a workpiece, and punches a hole at a position near and nearer a corner of the workpiece having adjacent metal plate surfaces forming an angle of from 90 degrees to 95 degrees at the corner.

Abstract: A pierce cam is compact, can save space, can be easily mounted, can reduce cost, can even be mounted to a sloped surface, and a pierce punch and required accessories can be ordered in bulk from a single source. A pierce cam includes a pierce punch, a body which is detachably provided with the pierce punch, a stripper which is fitted to the pierce punch inward of a leading end portion of the pierce punch and is biased by a coil spring in a direction away from the body, a rotating arm which is swingably mounted on the body and is movable into contact with a rear end surface of the pierce punch, and a driver which transfers a descending force of a press machine to the rotating arm, and hooks and ascends the rotating arm at the time of moving upward.

Abstract: In order to process by the same step even if the processing directions are different, reduce the number of the constituting parts of the die required for all the steps of the press dying as much as possible, easily design, and easily respond to the design change a double acting cam die comprising a slide cam base, a slide cam guided by the slide cam base and having a first processing member mounted thereto. An energizing body which is interposed between the slide cam base and the slide cam so as to energize the slide cam. An actuating cam which is brought into contact with the slide cam base and the slide cam so as to drive the slide cam, and has a second processing member mounted thereto. A guiding member which guides the actuating cam, and an energizing body which is interposed between the guiding member and the actuating cam so as to energize the actuating cam. An angle of processing incline of the second processing member is brought into line with an angle of cam incline of the slide cam base.

Abstract: A slide cam die including a slide cam base, a wedge-shaped slide cam sliding on a guide surface of the slide cam base and mounting a press tool such as a punch or a trimming blade thereon, and an actuating cam driving the slide cam in contact therewith. A press tool is mounted on the slide cam with an adapter plate interposed therebetween. With this configuration, when a pierce punch, or a flange block, or the like, needs to be removed for reasons such as the adjustment, the pierce punch or the flange block can be individually demounted without removing the entire slide cam. This results in reduced working time. In addition, since only the adapter plate is replaced, cost savings can be achieved by reusing the slide cam. Furthermore, a given slide cam can be used while still maintaining flexibility in design and use of the slide cam die.

Abstract: A pressing apparatus provides an urging force for a slide cam to press only when necessary, and elsewhere this pressing-force is maintained as small as possible. Abnormal wear and seizure of the slide cam, slide cam base and the sliding portion of the driven cam are prevented. The pressing apparatus can also provide a larger retracting force for the slide cam near a lower dead center of a pressing stroke. The present apparatus includes a slide cam slidably provided in a guidepost attached to the slide cam base and guided by the slide cam base, a pressing member held by the slide cam, a retracting-spring between the slide cam base and the slide cam for urging the slide cam, and a driven cam for contacting and driving the slide cam. A pressing-spring for urging the slide cam only near a lower dead center of a pressing stroke is provided between the slide cam base and the slide cam and/or between the slide cam and the driven cam.

Abstract: A negative-angle forming die includes a lower die half and an upper die half. A rotary cam is rotatably provided in the lower die half, and a slide cam is slidably opposed to the rotary cam. An automatic retractor is provided in the lower die half for pivoting the rotary cam to a position allowing the work to be taken out of the lower die half after a forming operation. The rotary cam is divided into an end rotary cam and a main rotary cam which are both disposed on a same axis of pivoting. The end rotary cam is not pivoted for an initial predetermined period of the retraction, and thereafter, the end rotary cam is moved axially toward the main rotary cam.

Abstract: The present invention provides a negative-angle forming die comprising a lower die half having a supporting portion for placing a sheet metal work, and an upper die half to be lowered straightly downward onto the lower die half for forming the work, an intrusion forming portion formed in the lower die half at an edge portion near the supporting portion inward of a downward stroke line of the upper die half, a rotary cam rotatably provided in the lower die half, a slide cam including an intrusion forming portion and slidably opposed to the rotary cam, and an automatic retractor provided in the lower die half for pivoting the rotary cam back to a position thereby allowing the work to be taken out of the lower die half after a forming operation, the work placed on the supporting portion of the lower die half being formed by the intrusion forming portion of the rotary cam and the intrusion forming portion of the slide cam, the slide cam forming the work by sliding, the automatic retractor pivoting back the rotary

Abstract: The present invention provides a negative-angle forming die comprising a lower die half and an upper die half. The lower die half has an intrusion forming portion, a rotary cam, a slide cam, and an automatic retractor. The work is placed on the lower die half being formed by an intrusion forming portion of the rotary cam and an intrusion forming portion of the slide cam. The slide cam forms the work by sliding. The rotary cam has two ends each including a supporting shaft projecting therefrom. The supporting shafts are supported by the lower die half for rotatably supporting the rotary cam.

Abstract: Disclosed is a negative-angle forming die. The die has upper and lower halves. The upper die half has a supporting portion for receiving a sheet metal work, and an intrusion forming portion. The lower die half carries a plate-like cam which can be moved toward the lower die half for forming the work. The die also has a rotary cam, the ends of which terminate in first and second shafts journaled in the lower die half. The die also has a slide cam, which itself has an intrusion forming portion. This portion is slidably opposed to the rotary cam. The die is equipped with a cam follower arm centrally fastened to the supporting shaft. One end of the cam follower arm carries a cam follower in operable relationship with the plate-like cam carried by the upper die half. In operation moving contact between the plate-like cam and the cam follower causes the cam follower arm to rotate. This in turn causes rotation of the rotary cam.

Abstract: A press die includes a lower die, a slide cam movable along the lower die, and an energizing body disposed between the slide cam and the lower die to abut against both surfaces thereof for biasing the slide cam for movement in one direction along the lower die. The slide cam is provided with a plug having an outer diameter that is larger than an outer diameter of the energizing body and abutting against an end surface of the energizing body. This arrangement enables easy attachment and detachment of the energizing body to and from the press die.

Abstract: A negative angle-forming die includes a lower die for mounting a thin metallic plate workpiece onto a supporting portion thereof, and an upper die descendable in a straight direction towards the lower die for forming the workpieces by abutting against the workpiece. A columnar body is arranged in a freely rotating manner on the lower die by a pair of spaced-apart bearings, and has an intruding forming portion formed at an edge portion thereof. A slide cam is formed with an intruding forming portion, and is arranged to oppose the columnar body in a freely sliding manner with respect to the lower die. An automatic returning tool is arranged at the lower die for retracting the columnar body in a rotating manner to an extent with which the workpiece can be taken out from the lower die upon completion of forming.

Abstract: A press apparatus includes a passive cam to which a processing member such as a punch is mounted. Removal of the passive cam from a lower die for repair is made to be easy, and workability is improved. The press apparatus has an actuation cam in an upper die, a passive cam in a lower die which is contact-pressed and driven by the actuation cam, a guide base in the lower die for sliding and guiding the passive cam, guide posts which are mounted across the guide base and move so as to slide the passive cam, and a force applying device for applying a force to the passive cam towards an opposite-work side. In such a press apparatus, the passive cam is fitted onto the guide base so that when the guide posts which are mounted across the guide base are removed, the passive cam can be lifted up and dismounted.

Abstract: A negative angular forming die having a lower die for supporting a workpiece. An upper die is lowered with respect to the lower die to abut against the workpiece for forming the workpiece. A columnar body is rotatably mounted on the lower die, and a groove is formed in the columnar body in the axial direction of the lower die. A slide cam is supported on the upper die and is opposed to the columnar body. An automatic returning tool is provided on the lower die for rotating and retracting the columnar body to a position at which the workpiece can be taken out from the lower die after the forming process is completed. The workpiece is placed on the supporting portion of the lower die with the columnar body being turned, and the slide cam is slid to form the workpiece by an entering forming portion of the columnar body. The columnar body is turned and retracted by the automatic returning tool after forming so that the formed workpiece can be taken out from the lower die.

Abstract: A noise-reducing structure of a processing machine reduces the noise generated when a movable member of the processing machine abuts against a workpiece located on a workpiece holder of the processing machine. The processing machine may be a drawing die including a punch, a blank holder fitted around the punch and vertically movably supported by a cushion pin, and a vertically movable die disposed to face the punch. The workpiece may be a thin plate which is placed on the blank holder. As the die is lowered, the thin plate is sandwiched between the blank holder and the die for drawing the thin plate by the punch. A lower die base plate is provided with a pivotable lever member for pushing the blank holder so that the blank holder begins movement before the die collides against the thin plate. An operation cam for driving the lever member is disposed at a position on the die facing the lever member, and the die collides against the thin plate on the blank holder after the blank holder is in motion.

Abstract: A silent structure for a drawing die, includes: a punch, a blank holder vertically movably supported by a cushion pin fitted over the punch, and a die disposed such as to oppose to the punch for moving the die up and down, in which a thin plate lifted by the cushion pin is placed on the blank holder, and the die is lowered to clamp the thin plate by the blank holder and the die, thereby drawing the thin plate, wherein a sub-blank holder is disposed between the cushion pin and the blank holder, a resilient material is interposed between the sub-blank holder and the blank holder, a run-up clearance is provided between the sub-blank holder and the blank holder, a run-up lever is rotatably mounted to the sub-blank holder for pressing the blank holder to allow the blank holder to run up before the die collides against the thin plate on the blank holder, an operation cam for driving the run-up lever is disposed on the die at a location thereof opposed to the run-up lever, and the die collides against the thin plate

Abstract: A press device which can be produced at a lower price includes a slide cam base, a slide cam guided by the slide cam base for mounting a machining member such as a punch, a biasing member provided between the slide cam base and the slide cam for biasing the slide cam, and an actuating cam for abutting the slide cam to drive the slide cam. When the slide cam base holds the slide cam, a pressing at a high accuracy with little deflection can be performed and the time required for machining the holding portions of the slide cam is short. The slide cam is slidably provided on a circular-section guide post installed on the slide cam base.

Abstract: A die assembly includes a forming portion to form a negative angle portion when an upper die is lowered in a straight line to abut a lower die. A cylindrical rotating cam with a groove formed therein in the axial direction is rotatably mounted in the lower die. A negative angle forming portion is formed in the groove edge portion of the rotating cam. A slide cam with a negative angle forming portion is mounted on the second upper die in such a manner to be opposed to the rotating cam. An automatic return device is provided on the lower die for rotating and retracting the rotating cam to enable the removal of the workpiece from the lower die after the forming process is complete. The rotating cam includes a plurality of rotating cam members, the rotation axis positions of which differ and are parallel to one another.

Abstract: A die assembly includes a forming portion to form a negative angle portion when an upper die is lowered in a straight line to abut a lower die. A cylindrical rotating cam with a groove formed therein in the axial direction is rotatably mounted in the lower die. A negative angle forming portion is formed in the groove edge portion of the rotating cam. A slide cam with a negative angle forming portion is mounted on the upper die in such a manner to be opposed to the rotating cam to enable the removal of the workpiece from the lower die after the forming process is completed. The rotating cam includes a plurality of cylindrical portions of varying diameters whereby an excessively bent negative angle forming portion may be formed by a single rotating cam.

Abstract: A method is disclosed of forming a thin plate having a negative angle-formed portion when a second die is moved straight to bump against a first die to form a work, when the first die is rotatably provided with a rotary cam having a negative angle forming portion, and the second die is equipped with a slide cam having a negative angle forming portion in its opposite position to said rotary cam, and the second die is so set to approach the first die, then the slide cam bumps against the rotary cam and moves to form a negative angle-forming portion between both cams, and after negative angle forming portions having been made, the second die withdraws from the first die and the rotary cam is made to rotate and retreat to the extent that the work can be taken out from the first die. In such a forming method, the negative angle forming portion of the bent work is divided into plural portions which are substantially straight within a range capable of processing with one rotary cam.