Abstract: The present invention provides a servo press system and a drawing method using the servo press system. The drawing method according to the aspect of the present invention includes: a stopping step of stopping the slide for a first period in a course of a stroke for performing drawing; a keeping step of reducing the die cushion force to below a predetermined die cushion force and keeping the die cushion force for a second period within the first period for which the slide is stopped; and a restarting step of restarting the slide after keeping the die cushion force for the second period, wherein drawing including the stopping step, the keeping step, and the restarting step is performed at least one time in the course of the stroke for performing drawing.

Abstract: There is provided a press machine which can apply a large compression force to a mold as well as impart smooth vibration only in a rectilinear advancing direction to the mold, and thereby can improve the press-formability. A main slide and a sub-slide constitute a slide and at the same time a cylinder-piston mechanism. During press-forming, a compression force is transmitted to the sub-slide (an upper mold) through hydraulic pressure applied interlockingly with driving of the main slide, and the sub-slide is vibrated with the hydraulic pressure being periodically changed. Favorable press-forming can be performed even under relatively difficult press-forming conditions, by controlling the vibration such that a vibration frequency of the sub-slide (the upper mold) becomes 9 Hz or higher but 33.3 Hz or lower and a vibration amplitude of the sub-slide becomes 0.05 mm or larger but 0.5 mm or smaller.

Abstract: According to the die cushion apparatus of a press machine and the die cushion controlling method of the present invention, in holding the cushion pad on standby at a desired standby position, it is possible to hold the cushion pad on standby in parallel with the lower faces of the dies mounted to the slide, and if the lower faces of the dies are inclined, it is possible to hold the cushion pad on standby in the state of being inclined. Through this configuration, it is possible to easily allow the material to come into contact with the lower faces of the dies from the beginning of the die cushion force control (beginning of the collision), and also possible to smoothen the die cushion action in the plane, thereby enhancing the formability.

Abstract: A removably supporting mechanism is provided for a workpiece holding device that can hold and release a workpiece. The workpiece holding device is removably supported on a crossbar extending substantially orthogonal to a workpiece conveying direction of a press machine. The removably supporting mechanism has a guide pin and a guide pin hole. The guide pin is fittable into and engageable with the guide pin hole. One of the guide pin and the guide pin hole is disposed on the workpiece holding device side, whereas another of the guide pin and the guide pin hole is disposed on the crossbar side. The guide pin and the guide pin hole can perform alignment of the workpiece holding device and the crossbar in a direction substantially orthogonal to an inserting direction of the guide pin.

Abstract: A die cushion device for a press machine includes: a hydraulic cylinder for supporting a cushion pad and generating a die cushion pressure when a slide of the press machine moves downward; a proportional valve and a hydraulic pump/motor connected in parallel between a lower chamber of the hydraulic cylinder and a low-pressure source; an electric motor connected to a rotating shaft of the hydraulic pump/motor; a die cushion pressure command issuer for outputting a predetermined die cushion pressure command; a pressure detector for detecting a pressure in the lower chamber of the hydraulic cylinder; and a controller for controlling an aperture of the proportional valve and a torque of the electric motor in a manner that the die cushion pressure becomes equal to a pressure corresponding to the die cushion pressure command, based on the die cushion pressure command and the pressure detected by the pressure detector.

Abstract: A controller for an electric servo press includes: a press load sensor for detecting a pressure force of the slide; a pressure-force determination device for determining whether the pressure force of the slide reaches one or a plurality of different pressure-force setting values based on the one or the plurality of different pressure-force setting values and an output signal of the press load sensor, and for generating a pressure-force achievement signal each time the pressure force of the slide reaches each of the one or the plurality of different pressure-force setting values; a servo motor drive controller for controlling driving of the servo motor; and a motion command device. In response to the pressure-force achievement signal, switching of a drive control mode by the servo motor drive controller is switched, and/or a motion to be commanded by the motion command device is switched.

Abstract: A control system of a servo press and a control method are provided for preventing an overload on a pressure capability of a press and a torque capability of a drive system. A control device of a servo press for pressing by transferring a drive force of a servomotor to a slide via a drive mechanism includes: a motion calculation unit for calculating slide target position data; a torque calculation unit for calculating process torque for pressing and control torque for speed change of the servo motor on the basis of slide target position data; a process system limit unit for limiting the calculated process torque to predetermined process limitation torque; and a drive system limit unit for limiting combined torque of the limited process torque and the control torque to predetermined drive limitation torque. The servo motor is driven on the basis of a command of drive limitation torque.

Abstract: Provided is a system for replacing a crossbar, which is capable of promptly and smoothly mounting and removing a crossbar for replacement between a workpiece transferring apparatus and a crossbar replacing apparatus. The crossbar is to be mounted to the workpiece transferring apparatus. The crossbar extends substantially orthogonal to a workpiece transferring direction in a press machine and is configured to be capable of retaining and releasing a workpiece. The crossbar is configured to be switchable between a state in which both end portions of the crossbar are rotatable relative to a center portion of the crossbar about a longitudinal axis of the crossbar, and a state in which both the end portions are not rotatable relative to the center portion.

Abstract: Provided is a workpiece transfer apparatus for a press machine including: a workpiece retaining device which is supported by a crossbar extending to be approximately orthogonal to a workpiece transfer direction, and is capable of retaining and releasing a workpiece; a guiding device which supports and guides the workpiece retaining device so that the workpiece retaining device is slidable along a longitudinal direction of the crossbar; a driving device which drives the workpiece retaining device supported and guided by the guiding device so that the workpiece retaining device is moved along the longitudinal direction of the crossbar; and a brake device which acts in a path different from a path of the driving device, the brake device being capable of fixing and releasing a position of the workpiece retaining device with respect to the longitudinal direction of the crossbar.

Abstract: A method for producing a high-strength sintered compact includes a press molding step and a sintering step, the press molding step including a first press molding step and a second press molding step, a heating step being provided between the first press molding step and the second press molding step, the first press molding step applying a first pressure to the mixed powder in a first die at room temperature that is less than a melting point of the lubricant powder to form a primary green compact, the heating step heating the primary green compact to the melting point of the lubricant powder, and the second press molding step applying a second pressure to the primary green compact in a second die at the melting point of the lubricant powder to form a densified secondary green compact, the second die being pre-heated to the melting point of the lubricant powder.

Abstract: To provide a work transfer apparatus which can transfer works at high speed with controlling respectively the posture of the right and left of works. The work transfer apparatus includes an arm moving back and forth between machines in order to transfer work(s), a crossbar coupled to the arm, and a pair of right and left work holding devices provided at the left and right sides of the crossbar and tilt drive devices being provided on the arm, respectively controlling the work holding devices to rotate around an axis of a longitudinal direction of the crossbar.

Abstract: A first die is filled with a mixed powder that includes a lubricant powder, and a first pressure is applied to the mixed powder in the first die to form a mixed powder intermediate compressed body. The mixed powder intermediate compressed body is heated to the melting point of the lubricant powder, and the heated mixed powder intermediate compressed body is placed in a second die that has been pre-heated to the melting point of the lubricant powder. A second pressure is applied to the mixed powder intermediate compressed body in the second die to form a high-density mixed powder final compressed body.

Abstract: A slide motion control apparatus for a mechanical press comprising: a slide which is disposed so as to be relatively vertically movable with respect to a driven body to which a drive force is transmitted through a con rod of the mechanical press; a relative position commander that outputs a relative position command indicating a relative position of the slide with respect to the driven body; a relative position detector that detects a relative position of the slide with respect to the driven body, and outputs a relative position detecting signal indicating the detected relative position; a servomotor; a drive mechanism that relatively moves the slide with respect to the driven body by a drive force of the servomotor; and a controller that controls the servomotor based on a relative position command signal output from the relative position commander, and the relative position detecting signal output from the relative position detector.

Abstract: Provided is a low-cost control device for an electric servo press, which is excellent in operability and operation efficiency, capable of abruptly stopping a servomotor in a safe and reliable manner within a short time period in response to an abrupt stop command while avoiding hard actuation of a mechanical brake, even in the case of runaway of the servomotor or the like. An electric servo press performs switching to rotation stop control for a servomotor according to an abrupt stop motion based on an abrupt stop command signal to perform brake actuation to cause a mechanical brake to actually start braking and to forcibly interrupt rotational drive power to the servomotor at a scheduled stop time at which the servomotor is stopped according to the abrupt stop motion.

Abstract: A power supply unit for a press machine having a converter (converter circuit) connected to a commercial AC power supply, and an inverter (inverter circuit) connected to a press motor, includes an electrical energy bank, an inrush prevention circuit, an inrush prevention instruction signal generation section, and a contactor switch section, wherein contactors of the inrush prevention circuit are switched from on ON state to an OFF state and inrush prevention resistors of the inrush prevention circuit are connected to AC phase current paths on condition that the inrush prevention instruction signal generation section has generated and output an inrush prevention instruction signal (Sres) during press operation.

Abstract: A conveying device includes annular continuous bodies each extending in a conveying direction of an object to be conveyed and each being rotationally driven, and a plate-like member extending in a conveying lateral direction and mounted on each of the annular continuous bodies. The conveying device conveys the object by placing the object on a conveying surface formed by the plate-like member, in which the plate-like member mounted on one of the annular continuous bodies. The plate-like member mounted on another of the annular continuous bodies, which is adjacent to the one of the annular continuous bodies, are arranged in a staggered manner without overlapping with each other when viewed from a direction orthogonal to the conveying surface. Adjacent two of the annular continuous bodies have an interval therebetween in the conveying lateral direction. The interval is expandable and contractable.

Abstract: An electric servo press machine is configured to convert a rotation of an electric servomotor into a reciprocating linear motion of a slide to perform press working on a workpiece. The machine includes a clutch mechanism interposed in a power transmission path between the servomotor and the slide, and a brake mechanism for applying a brake onto the slide under a disconnected state in which the servomotor and the power transmission path are decoupled from each other by the clutch mechanism. The machine brings the clutch mechanism into the disconnected state and applies the brake onto the slide upon an immediate stop request, and recovers from immediate stop under a state in which a phase shift between the servomotor and the power transmission path ranging from the clutch mechanism in the disconnected state to the slide is eliminated under a connected state of the clutch mechanism.

Abstract: A servo transfer press system generates a press phase signal and a transfer phase signal that are synchronized with a master phase signal, performs a press operation according to a reference press motion based on the press phase signal, and performs a transfer operation according to a reference transfer motion based on the transfer phase signal. The servo transfer press system includes a reference interference diagram generation section, a reference interference diagram storage section, an operation interference diagram generation section, an interference presence/absence comparison-determination section, and a phase signal relative relationship adjustment section, and performs a transfer press operation while avoiding interference by performing an automatic phase signal adjustment when a motion has been changed.

Abstract: A tandem press system includes a plurality of presses disposed in a workpiece transfer direction, a workpiece transfer device that transfers a workpiece from an upstream press to a downstream press using a tool mounted on the workpiece transfer device via a crossbar, and a tool replacement device that replaces the tool mounted on the workpiece transfer device. The tool replacement device can be transferred from an inter-press space between the upstream press and the downstream press to an external space in a tool replacement direction independently of transfer of a bolster provided with a die to an external space in a die replacement direction.

Abstract: Provided is a low-cost servo press promoting energy saving by driving a press machine by a driving system suited for the magnitude of a load on a worked object. It includes a first motor coupled to a slide drive shaft to ascend/descend a slide, a second servo motor driving a flywheel, a clutch coupling/decoupling the second servo motor to/from the slide drive shaft, and a press controller controlling rotation of the first and second servo motors and coupling/decoupling of the clutch. The press controller controls to decouple the clutch when the press is small-loaded, thereby ascending/descending the slider by driving the first servo motor, and to couple the clutch when the press is large-loaded, thereby ascending/descending the slider by driving the first and second servo motors.