Abstract: An object of the present invention is to provide an electric direct-acting die clamping unit of an injection molding machine whose entire length can be reduced. A movable platen is arranged to face a stationary platen. A stationary die is attached to the stationary platen, whereas a movable die is attached to the movable platen. The movable platen is connected to the front of the backup plate. A nut of a ball screw is fixed at each of diagonally-opposed corners of the backup plate. The threaded rod of the ball screw passes through the backup plate via the nut. The tip portion of the threaded rod is rotatably connected to the stationary platen. The rear end portion of the threaded rod is threaded through a support plate via the bearing and connected to a motor.

Abstract: The present invention is directed to a method of monitoring operation data for quality control with a little possibility that a nondefective product is mistakenly determined as a defective product even if the operation data fluctuates in a large waviness curve. Every time an operation data piece for quality control is obtained, a moving average of the predetermined number of data pieces lately obtained is calculated. When the deviation of a data piece from the moving average exceeds the tolerance limit, an alarm is generated. By employing the method of the present invention for monitoring operation data such as charging time, injection time and the amount of cushion in an injection-molding machine, the accuracy of determination as to a defective or nondefective can be improved.

Abstract: An object of the present invention is to suppress clamping force from sharply increasing when dies are clamped in an electric direct-acting die clamping unit of an injection molding machine. A stationary platen and a back plate are arranged at both ends of a base. A movable platen is arranged to face a stationary platen. A stationary die is attached to the stationary platen, whereas a movable die is attached to the movable platen. The tip portion of a threaded rod of a ball screw is fixed at the back surface of the movable platen via a load cell. A nut of the ball screw is accommodated in a housing and supported by the bearing. The housing is connected to the front surface of the back plate via the coil spring. When the nut is rotated the threaded rod is driven to move the movable platen back and forth.

Abstract: An object of the present invention is to suppress a clamping force from sharply increasing when dies are clamped in an electric direct-acting die clamping unit of an injection molding machine. A movable platen is arranged to face a stationary platen. A stationary die is attached to the front surface of the stationary platen, whereas a movable die is attached to the front surface of the movable platen. The movable platen is connected to the front surface of a backup plate via four coil springs. A nut of a ball screw is fixed at each of diagonally-opposed corners of the backup plate. The threaded rod of the ball screw passes through the backup plate via the nut. The tip portion of the threaded rod is rotatably connected to the stationary platen. The rear end portion of the threaded rod is connected to a motor.

Abstract: The object of this invention is to suppress the generation of surge pressure at the moment of shifting from the filling step to the holding step, thereby ensuring the stabilization in quality of molded products. In the filling step, the screw is advanced from the charging finish point at a predetermined speed while renewing the positioning command at time intervals. Simultaneously, the position of screw is monitored to see if it has reached the holding initiating point. When the screw has reached the holding initiating point, the holding step is initiated, and the next positioning command is switched from the present positioning command into one wherein a predetermined value of correction is added to the present positioning command, thereby decelerating (or moving back) the screw. After shifted to the holding step, the position of screw is controlled while renewing the positioning command at time intervals.

Abstract: An injection unit including a heating barrel and an injection screw rotationally and axially movable and placed in the heating barrel is disposed on one side of a clamping mechanism for clamping a mold. The injection screw is driven and controlled for operation through a ball screw by an electric motor. Products, each of a moving speed of the ball screw and an operating current supplied to the electric motor in a unit time, are accumulated to calculate a total energy value indicating the amount of total energy supplied to the ball screw. A life energy value is predetermined on the basis of products, each of force generated by the ball screw and a moving speed of the ball screw. It is decided that a life of the ball screw has terminated when the total energy value A is equal to or greater than the life energy B (A≧B).

Abstract: A mold clamping apparatusm for an injection molding machine comprises a stationary platen fixedly holding the stationary mold, a movable platen fixedly holding the movable mold and disposed opposite to the stationary platen, tie bars for guiding the movable platen for movement toward and away from the stationary platen, a movable platen driving means for moving the movable platen along the tie bars to close and open the mold, a movable platen fixing means for fixing the movable platen to the tie bars at a set position immediately before a position where the movable mold is joined to the stationary mold, and a clamping force applying means comprising sealed hydraulic cylinder actuators capable of converting energy of a hydraulic fluid into an intensified mold clamping force and of applying the intensified mold clamping force to the stationary platens.

Abstract: An injection speed control procedure is applied to controlling an injection screw included in an electric injection molding machine and driven by an electric motor. An injection process is divided into a plurality of injection stages. Injection speed at which the injection screw is moved is changed at a time point when a value PS obtained by integrating injection pressure with respect to the position of the injection screw or a value PT obtained by integrating injection pressure with respect to injection time coincides with a predetermined reference value determined for each injection stage.

Abstract: A mold clamping apparatusm for an injection molding machine comprises a stationary platen fixedly holding the stationary mold, a movable platen fixedly holding the movable mold and disposed opposite to the stationary platen, tie bars for guiding the movable platen for movement toward and away from the stationary platen, a movable platen driving means for moving the movable platen along the tie bars to close and open the mold, a movable platen fixing means for fixing the movable platen to the tie bars at a set position immediately before a position where the movable mold is joined to the stationary mold, and a clamping force applying means comprising sealed hydraulic cylinder actuators capable of converting energy of a hydraulic fluid into an intensified mold clamping force and of applying the intensified mold clamping force to the stationary platens.

Abstract: An injection apparatus for a motor-driven injection molding machine comprised a barrel unit for heating and plasticating polymer material, a screw disposed in the barrel unit rotatably and movably in the axial direction, a first rotating shaft having one end connected to a rear end of the screw, a charging motor for driving the first rotating shaft for rotation, a ball screw mechanism consisting of a second rotating shaft having a threaded rod portion, and a threaded nut member engaging with the threaded rod portion, an injection carriage having a front plate for mounting the barrel unit thereon, and a rear plate for supporting the second rotating shaft at the rear end thereof, an injection motor for driving the ball screw mechanism, and an intermediate mount plate, disposed movably between the front plate and the rear plate, for linking the first rotating shaft to the second rotating shaft coaxially with a predetermined distance spaced apart between the rear end of the first rotating shaft and the front end

Abstract: A mold clamping apparatus for an injection molding machine including a stationary platen fixedly holding the stationary mold, a movable platen fixedly holding the movable mold and disposed opposite to the stationary platen, tie bars for guiding the movable platen for movement toward and away from the stationary platen, a moveable platen driving element for moving the movable platen elements for fixing the movable platen to the tire bars at a set position immediately before a position where the movable mold is joined to the stationary mold, and a clamping force applying element including hydraulic cylinder actuators capable of converting energy of a hydraulic fluid into an intensified mold clamping force and of applying the intensified mold clamping force to the stationary platen.

Abstract: The duty of a current to be supplied to an injection motor is calculated on the basis of the ratio between set injection time for which the injection motor operates and molding cycle time, a shaft torque of the injection motor is calculated on the basis of a set maximum injection force of the injection molding condition, a maximum current for the injection motor is determined on the basis of the calculated shaft torque, and it is decided that the injection motor is overloaded, an alarm is given, a duty for a current that enables continuous molding is retrieved for the maximum current, a state that enables continuous molding is displayed and the molding cycle time determining the duty of the current that enables continuous molding is corrected when the current having the calculated desired duty is smaller than the maximum current.

Abstract: A tie-bar less clamping apparatus is intended for use in combination with an injection molding machine. A stationary platen (24) is fixed to a first support section (20B) of a support frame (20), and linear motors (30) are incorporated into the second support section (20C) of the support frame (20). One end of an armature (34) included in each linear motor (30) and having the shape of a rod is connected to a movable platen (28).

Abstract: A sealed hydraulic intensifier has a sealed hydraulic cylinder actuator having a cylinder defining a piston chamber, a piston fitted in the piston chamber of the cylinder, and a piston rod connected to the piston, and a pressure controller disposed adjacent to the piston chamber of the sealed hydraulic cylinder actuator to control.

Abstract: An injection apparatus of an injection molding machine, for easy control of the charging motor and the injection motor and highly precise control of the back pressure of a screw thereby enabling performance of the proper charging operation, has an injection motor with a rotor adapted to act as a ball screw nut and which is secured to an injection carriage having mounted thereon a heating barrel of the injection apparatus. The injection motor has a shaft forming a ball screw in one end portion of the shaft connected to a screw of the injection molding machine. The ball screw is screwed into the rotor of the injection motor. The other end of the shaft forms a spline portion, and is connected to a charging motor that has a hollow drive shaft whose inside-diameter portion is spline-fitted onto the spline portion of the shaft.

Abstract: A threaded shaft (52) for operating toggle joint (44) is driven for rotation by a first servomotor (46). A bevel gear (56) is mounted on the threaded shaft (52) for rotation relative to the threaded shaft (52). The bevel gear (56) is driven for rotation by a second servomotor (57). Bevel gears (60) each having a threaded bore are supported on a rear plate (42) are engaged with threaded sections (40A) of tie bars (40), respectively. Power is transmitted from the bevel gear (56) through power transmitting mechanisms (61) to the bevel gears (60). Each power transmitting mechanism (61) comprises bevel gears (62, 63) engaged with the bevel gears (56, 60), respectively, and a clutch (64) interposed between the bevel gears (62, 63). The clutches (64) are engaged and disengaged selectively to adjust the parallelism of a movable mold (36) with respect to a stationary mold (32).

Abstract: A SAW device formed by providing at least one interdigital transducer on a piezoelectric substrate which is prepared by forming a (1120) ZnO piezoelectric thin film on a (0112) plane .alpha.-Al.sub.2 O.sub.3 substrate, and forming reflectors on both sides of the interdigital transducer along a surface wave propagation direction. Each of the reflectors is so structured that a ratio H/.lambda. of its thickness H to a wavelength .lambda. of a surface wave is in a range of 0.015 to 0.041.

Abstract: When a zinc oxide piezoelectric crystal film is epitaxially grown on an R-plane sapphire substrate by sputtering, a target containing not more than 4.5 percent by weight of Cu with respect to the total content of Zn and Cu is employed so that the zinc oxide piezoelectric film contains Cu. Thus, it is possible to obtain a zinc oxide piezoelectric crystal film having excellent orientation.

Abstract: When a zinc oxide piezoelectric crystal film is epitaxially grown on an R-plane sapphire substrate by sputtering, a target containing not more than 4.5 percent by weight of Cu with respect to the total content of Zn and Cu is employed so that the zinc oxide piezoelectric film contains Cu. Thus, it is possible to obtain a zinc oxide piezoelectric crystal film having excellent orientation.

Abstract: Disclosed herein is a zinc oxide piezoelectric crystal film which is grown on an R-plane sapphire substrate to orient its c-axis in parallel with the substrate surface. In order to improve orientation of the zinc oxide piezoelectric crystal film used is a Zn target for forming the zinc oxide piezoelectric crystal film by sputtering contains not more than 5 percent by weight of nickel or not more than 4.5 percent by weight of iron with respect to Zn.