Abstract: A press includes a reciprocation unit having a crank structure which is driven in horizontal reciprocation by an associated press drive. A motion direction shifting unit having a link structure is coupled to the reciprocation unit a ram so as to reciprocate the ram vertically between an upper position and a lower rest position in response to the horizontal reciprocation of the reciprocation unit, such that the ram remains in a state of substantial rest with respect to the shifting unit for a predetermined period of time upon reaching the lower position. A control unit controls a hydraulic fluid supply system to cause a pressure applying device to apply a controlled press forming force to the ram when a sensor detects that the ram is in the rest state.

Abstract: The present invention relates to a differential pinion for automobiles or the like, a metal mold for plastic working the differential pinion, and a method for plastic working with the above metal mold. And particularly the differential pinion of the present invention is provided with an end relief section which is effective to reduce a noise and has a continuous fiber flow from a tooth face to the end relief section providing a high pitting resistance. The metal mold for plastic working the differential pinion of the present invention can provide the internal pressure working area of the die in a position deep below the open end by a required distance therefrom, thereby providing the metal mold with higher rigidity and strength. Further, in the plastic working method of the present invention, it is very easy to position the punch under pressure stress in the axial direction.

Abstract: A Slide driving apparatus of press machine, wherein a main gear 3 as a rotational drive member and a lever member 10 as a driven member are opposed to one another in a eccentric state which an axes O.sub.1 and O.sub.2 are separated, the main gear 3 and the lever member 10 being connected to one another by a connecting member 13 consisting of a pin member 11 and a bush member 12. A drive rotation locus A which can be traced, round the axis O.sub.1, by a movement of a connecting center O.sub.5 where the main gear 3 and the connecting member 13 are connected, and a driven rotation locus B which can be traced, round the axis O.sub.2, by a movement of a connecting center O.sub.4 where the lever member 10 and the connecting member 13 are connected, intersect one another at points of C and D. A slide of the press machine is connected, by the connecting rod, to an eccentric portion 8A of the crankshaft 8 where the lever member 10 is fixed.

Abstract: A mechanism for guiding a slide of a press machine is disclosed. The slide is connected to a crank shaft extending laterally through connecting rods. The press further includes a bolster supporting a bottom die and a top die attached to the slide. An upper guide arrangement is provided between the slide and columns extending upward from a press machine bed for maintaining the slide parallel to the bolster by guiding a vertical stroke of the slide via contact at laterally spaced positions on front and rear sides of the slide. A lower guide is provided for horizontally adjusting the horizontal position of at least one of a first vertical structure including the slide and the press machine bed or of a second vertical structure including the top die and the bottom die to accurately set the dies.

Abstract: A method for automatically adjusting die height in a press having a plurality of dies aligned in a work transfer direction includes a load pattern setting member for inputting possible load patterns, each pattern corresponding to the number of dies under load. A correction setting member is provided for inputting an amount of correction (compensation) by which the position of the bottom of the slide in each load pattern is rectified to a basic position corresponding to a basic load pattern. A pattern identifier is provided for identifying the current load pattern when the slide is at a given position. A correction controller is provided for selecting the proper amount of correction of the position of the bottom of the slide for the identified load pattern and sending a drive control signal corresponding to this amount to a slide position adjustment unit.

Abstract: This invention relates to a forming machine used for full enclosed die forming etc. The forming machine of this invention consists of inserting a punch into at least one of a pair of dies disposed to face each other, supporting the die having the punch inserted therein by one end of a ring member accommodated in a holder, and disposing the other end of the ring member within a cylinder chamber formed within the holder; the above ring member has a piston member disposed within it, the above punch is supported by one end of the piston member, and the other end of the piston member is disposed in the above cylinder chamber formed within the holder or a cylinder chamber communicated with the holder.

Abstract: A device for automatically adjusting die height in a press having a plurality of dies aligned in a work transfer direction includes a load pattern setting member for inputting possible load patterns, each pattern corresponding to the number of dies under load. A correction setting member is provided for inputting an amount of correction (compensation) by which the position of the bottom of the slide in each load pattern is rectified to a basic position corresponding to a basic load pattern. A pattern identifier is provided for identifying the current load pattern when the slide is at a given position. A correction controller is provided for selecting the proper amount of correction of the position of the bottom of the slide for the identified load pattern and sending a drive control signal corresponding to this amount to a slide position adjustment unit.

Abstract: A press machine slide stroke adjusting apparatus comprises an eccentric sleeve connected to a slide and fitted over a circular eccentric portion of a crank shaft, first teeth provided on the eccentric sleeve and concentric to the circular eccentric portion, a main gear disposed on the crank shaft in coaxial relationship therewith, and second teeth meshing with the first teeth and provided on main gear coaxially with the crank shaft. The crank shaft is disconnected and connected from and to the main gear by coupling. A hydraulic actuator disengages the crank shaft from the main gear. The rotation of the crank shaft disconnected from the main gear is prevented by engagement of a pin and an engaging hole in an engaging block. Under such conditions, the eccentric sleeve is turned relative to the circular eccentric portion to adjust a vertical stroke of the slide.

Abstract: A predetermined amount of melted thermoplastic resin of raw material is injected into a molding space which is previously set to a temperature higher than that at which the resin beings to harden under atmospheric pressure and which has a capacity larger than a volume of a product. The injected resin is cooled in the molding space and pressurized before the resin is cooled to the temperature at which the resin begins to harden under atmospheric pressure. When pressurized, the glass transition temperature of the thermoplastic resin is shifted to a higher temperature so that the thermoplastic resin hardens in slight reduction of the temperature. The resin is cooled in the pressurized state until the resin possesses the dynamic rigidity under room temperature and atmospheric pressure.

Abstract: A crank driving device for a press designed in serial type eccentric structure. An eccentric element of crankshaft connected to a connecting rod, and an eccentric mechanism to provide a second eccentricity, are separated in the axial direction of the crankshaft. The opposite ends of crankshaft are provided, in respective eccentric holes in a pair of rotatable bodies which rotate synchronously on a basic axial line. The crankshaft is axially displaceable between a position in which it rotates in synchronism with the rotatable bodies and a position in which the crankshaft and the pair of rotatable bodies can be rotated relative to each other. The eccentricity of the device is adjusted by rotating crankshaft and pair of rotatable bodies, relative to each other, and then maintaining the relative angle of the crankshaft and the pair of rotatable bodies at constant value by connecting means after adjustment.

Abstract: An injection molding method with stamping compression obtains an optical lens or other molded article from thermoplastic resin. A cavity is heated to a temperature at which resin can be maintained in a molten state under normal temperature. Measured and molten resin is injected into the heated cavity through a sprue part, a runner part and a gate part. After the injection, the sprue part is sealed. The injected resin is maintained in the molten state at this time. The injected resin is then hardened in the heated cavity by applying a pressure which can provide a dynamic modulus of elasticity of the resin at the normal temperature and normal pressure. The resin hardened by the pressurization is then cooled to a removal temperature while reducing the pressure so as to maintain the dynamic modulus of elasticity of the resin at the dynamic modulus of elasticity of the resin at normal temperature and normal pressure.

Abstract: An overload protector for press machine protects a press machine from a damage when the press machine receives an overload in operation. It is applicable to a two-point type press machine with two connecting rods between a crank shaft and a slide. A pressurized oil supply means comprising a pressure generator and pressure oil supply line delivers pressurized oil to two hydraulic pressure chambers of two overload-protections means. The pressurized oil supply line has two relief valves connected thereto in hydraulic parallel to each other. Each of the relief valves receives the hydraulic pressure from one of the hydraulic pressure chambers reduced by an occurrence of a localized load and releases the hydraulic pressure contained in the other hydraulic pressure chamber so as to nullify the localized load.

Abstract: A press machine includes a first rotary shaft which rotates in synchronism with a press crankshaft, a second rotary shaft which is coaxial with the first shaft and which has a drive cam for actuating a knock-out pin, and a clutch for connecting and disconnecting the first and second shafts. Knock-out timing is adjusted by releasing the clutch to separate the shafts and rotating one of the shafts through a predetermined angle relative to the other to produce a predetermined rotational phase difference between them. In the preferred embodiments, the second shaft is axially aligned with the first shaft, and is rotatable but axially immovable with respect to the press frame. A driving gear and a driven gear are provided between adjacent portions of the first and second shafts. The second shaft has a bore in which a lightweight, axially movable shaft is mounted.

Abstract: A method and apparatus for manufacturing a product such as a constant velocity joint having a recess whose opening has a lesser diameter than its interior, by ironing a workpiece supplied to working parts of punches which workpiece is pre-formed into a hollow structure whose opening has an excess of metal required to be ironed. A group of punches are mounted in a loop around a punch guide for relative axial movement. The group of punches includes a set of first punches and a set of second punches, disposed alternately. Each punch has a working part at an upper end thereof and the working parts are closely assembled in a closed loop at the time of the forming process. Each punch is formed with a groove in a side which is slidable along the punch guide. The grooves in the first punches are different in length from those in the second punches.

Abstract: According to the present invention, there is provided a fully enclosed die forging apparatus having an upside die and an underside die disposed opposedly in a vertical direction between a slide and a bolster. There is an upside cylinder mechanism contained in the slide which urges the upside die downward. There is an underside cylinder mechanism contained in the bolster which urges the underside die upward. An upside punch is inserted in the upside die and moves synchronously with the movement of the slide. An underside punch is inserted into the underside die and is supported by the bolster. There is a cam mechanism that causes both punches to rush into the dies, respectively, by moving the upside die and underside die toward the underside punch at a speed slower than the moving speed of the slide. The cam mechanism has a push pin, and a cylinder with an abutting piston that prevents damage to the cam mechanism by reducing pressure that may be exerted on the cams.

Abstract: According to the present invention, there is provided a full enclosed die forging apparatus having an upside die and an underside die disposed opposedly in a vertical direction between a slide and a bolster. There is an upside cylinder mechanism contained in the slide which urges the upside die downward. There is an underside cylinder mechanism contained in the bolster which urges the underside die upward. An upside punch is inserted in the upside die and moves synchronously with the movement of the slide. An underside punch is inserted into the underside die and is supported by the bolster. There is a cam mechanism that causes both punches to rush into the dies, respectively, by moving the upside die and underside die toward the underside punch at a speed slower than the moving speed of the slide.

Abstract: According to the present invention, there is provided a full enclosed die forging apparatus having an upside die and an underside die disposed opposedly in a vertical direction between a slide and a bolster. There is an upside cylinder mechanism contained in the slide which urges the upside die downward. There is an underside cylinder mechanism contained in the bolster which urges the underside die upward. An upside punch is inserted in the upside die and moves synchronously with the movement of the slide. An underside punch is inserted into the underside die and is supported by the bolster. A die moving mechanism having a support member is positioned between the underside die and the underside cylinder mechanism. A push pin is adapted to move synchronously with the slide.

Abstract: A vertical injection molding machine having an upper die (26) and a lower die (27) which are adapted to be brought together in the vertical direction by the force produced by a die closing device. The injection molding machine has an injection unit 1 disposed below the lower die (27) and is hinged through a hinge shaft (36) to a truck (35) movable along rails (37), such that the injection unit 1 is swingable vertically about the axis of the hinge shaft (36). The vertical swinging motion of the injection unit 1 is effected by cylinders (38) connected to an injection head (2) of the injection unit (1). A compression forming cylinder device (70) is provided on the lower end of each of a plurality of tie-bars which are connected between the upper die (26) and the lower die (27).

Abstract: A crankshaft mechanism for use with a press having a slide member which comprises an eccentric crankshaft having first and second cylindrical portions. The first portion is rotatable within a housing about a longitudinal axis and the second portion, of greater diameter than the first portion, has a center which is displaced radially from the longitudinal axis. An eccentric sheave is rotatably mounted on the outer circumference of the second portion of the crankshaft, and a connecting member is rotatably mounted on the outer circumference of the sheave. The second portion of the crankshaft, sheave and connecting member are provided with first, second and third radial bores respectively which are in alignment when the crankshaft is at its bottom dead center position. A locking pin slides within the radial bores and is displaceable by an actuator to a first position in which the crankshaft is connected to the sheave and a second position in which the sheave is connected to the connecting member.

Abstract: A dynamic balancing device for a press having a crankshaft, a connecting rod mounted on an eccentric portion of the crankshaft and connected to a slide at its free end. The balancing device has links mounted on the eccentric portion of the crankshaft and extending in the direction opposite the direction in which the connecting rod extends, a pair of balancing weights provided on opposite sides of the crankshaft and vertically movable; and a pair of levers having their one ends pivotally attached to the upper ends of corresponding balancing weights and having the other ends of corresponding balancing weights and having the other ends overlapped and pivotally connected with the links, the levers being pivoted on the press at their respective mid-portions.