Abstract: A method for determining the clamping force of a force-actuated, rotationally drivable clamping device of a machine tool. An object is clamped with an actuation force F. Model-based calculation of the clamping force Fcalc to be expected is performed based on the actuation force F and the operating parameters of the machine tool in a control unit of the machine tool. Performing clocked measurement of the clamping force Freal acting upon the object in the clamping device within the time span of a measurement interval I. Wireless transming the measured value Freal to the control unit of the machine tool, and comparison of the measured value Freal with the calculated clamping force Fcalc. The measurement interval is adapted if the comparison reveals a deviation which reaches a threshold value.

Abstract: A drive system for driving a chuck device includes a controller and a switching valve, which is a 5-port servo valve, switching the state of supply of compressed air to the chuck device based on a valve command signal from the controller. During switching of first and second fingers from a closed position to an open position, when the axial position of a piston reaches a switch point, which is a predetermined distance short of a target position corresponding to a freely selected intermediate position of the first and second fingers, the switching valve is opened at a third opening for a predetermined period and then switched to be opened at a fourth opening so that supply and discharge of compressed air are stopped. As a result, the first and second fingers stop in the intermediate position.

Abstract: A gripping system which is monitored based on CEMF and a method for controlling the same includes: using a controller to instruct a drive unit to rotate a stepper motor; using the controller to compare the control instruction with a control parameter matrix stored in an access unit; obtaining a CEMF threshold by checking the position of the actual CEMF in the control parameter matrix; using the controller to continuously monitor the actual CEMF; and using the controller to compare the actual counter electromotive force with the obtained corresponding counter electromotive force threshold, stopping the stepper motor and letting the gripper maintain the gripping status when the actual counter electromotive force is smaller than or equal to the counter electromotive force threshold, and maintaining driving of the stepper motor when the actual counter electromotive force is larger than the counter electromotive force threshold.

Abstract: The invention relates to a device controlling a chuck of a machine tool and an auxiliary equipment thereof, thereby facilitating a setup work. Gripping and releasing of a work are confirmed by registering a work gripping position and a work releasing position of a chuck, a kind of a used chuck, and a gripping direction of a work in an external memory device every product type of the work, transferring the work gripping position and the work releasing position in correspondence to the product type to a controller of a machine tool displaying them on a display of an operator control panel, detecting a position of an operation rod opening and closing a claw of the chuck by a stroke sensor, referring to the gripping position of the work, and detecting conformity of the detecting position and set values of the work gripping position and the work releasing position.

Abstract: Expansion chuck (1) with a base body (9) and an expansion sleeve (10) which is surrounded by a receptacle (6) for a tool, wherein the expansion sleeve (10) inside the base body (9) and at the front end (3) of the receptacle (6) is connected pressure-tight to the base body (9), thus forming a pressure chamber (11) between the base body (9) and the expansion sleeve (10), characterized in that the expansion sleeve (10) at the front end (3) of the base body (9) extends radially outward to an connecting section (34), where it is connected to the base body (9) in a pressure-tight manner.

Abstract: A tensile test machine which has a simple structure and which can measure the strength of a sample having a minute tensile strength is provided. The tensile test machine 100 has a first gripping member 117 and a second gripping member 125 which oppose each other in the horizontal direction and grip two end portions of a sample WK. The first gripping member 117 is supported by a moment receiving member 113a of a torque meter 113 through a first support beam 116 and a tensile force transmitting member 115. The tensile force transmitting member 115 is formed so as to extend in the radial direction of the moment receiving member 113a. The second gripping member 125 is supported by a displacement table 121 through a second support beam 124 and a gripping member support base 123. It is displaced in the direction away from the first gripping member 117, and the amount of displacement is measured by a displacement measuring device 128.

Abstract: In a chucking device and a chucking method for a machine tool which grip a workpiece that serves as a target object to be processed by the machine tool, a first cylinder and a second cylinder are controlled based on the position of a piston of the first cylinder detected by a length measuring sensor, and the position of a piston of the second cylinder detected by a length measuring sensor. In this manner, the workpiece is gripped by respective gripping members at a predetermined position, i.e., the axial center, of a chuck main body.

Abstract: An automated vehicle steering centering assembly for a centering process for marking a center of a steering column includes a housing connected to a robotic arm for movement therewith. A drive mechanism is mounted to the housing. A chuck is rotatably connected to the drive mechanism. The chuck includes a moveable gripper jaw having a splined inner surface for mating with a splined portion of the steering column. A pneumatic mechanism is mounted to the housing and operably connected to the chuck. Air pressure supplied from the pneumatic mechanism to the chuck moves the gripper jaw between an open position and a closed position so as to grip the steering column.

Abstract: Provided is a tool tight-contact-state detector for a machine tool which is capable of accurately and stably detecting whether or not a tool or a tool holder having the tool attached thereto is mounted to a main spindle in tight contact therewith. While rotation of a main spindle (13) is stopped, hydraulic pressure is supplied from a hydraulic pressure supply unit (28) to a cylinder section (20) so as to bring a piston member (21) to into contact with a main spindle head (11) and the main spindle (13) against a biasing force from an O-ring (22). Air is thereby allowed to be supplied to air ejection holes (27a, 27b, 27c), which are formed in a forward end face (13a) of the main spindle (13), from the main spindle head (11) side through the piston member (21).

Abstract: A tool replacing device including a case member is disclosed. In the case member, engaging balls supported between a holding member and a movable member is projected into the holding member by an extruding surface of the movable member, resiliently urged by a second spring, thereby allowing a tool to be engaged. By pressing the movable member against a resilient urging force of the second spring, the engaging balls can be moved in the movable member. Also, since there are provided shock sensors for detecting a moving distance of the holding member holding the tool, collision or the like of the tool can be detected. Even if power supply is stopped, the present tool replacing device can hold the tool.

Abstract: A clamping fixture features a chuck provided with a locking mechanism for releasably locating a workpiece pallet. The locking mechanism comprises a plurality of clamping members which in the locked position are engineered to engage a clamping spigot connected to the workpiece pallet. Each clamping member, or alternatively an actuating member assigned to a clamping member, is provided with a feedthru bore which on correct locking and/or release of the corresponding clamping members is closed off at one end. The feedthru bores are connectable by a common connecting conduit to a compressed air source. In addition, at least one sensor is provided for sensing air flow in the connecting conduit by means of which it can detected whether the clamping members are correctly released or locked.

Abstract: Provided is a tool tight-contact-state detector for a machine tool which is capable of accurately and stably detecting whether or not a tool or a tool holder having the tool attached thereto is mounted to a main spindle in tight contact therewith. While rotation of a main spindle (13) is stopped, hydraulic pressure is supplied from a hydraulic pressure supply unit (28) to a cylinder section (20) so as to bring a piston member (21) to into contact with a main spindle head (11) and the main spindle (13) against a biasing force from an O-ring (22). Air is thereby allowed to be supplied to air ejection holes (27a, 27b, 27c), which are formed in a forward end face (13a) of the main spindle (13), from the main spindle head (11) side through the piston member (21).

Abstract: The present invention relates to a machine tool for machining of workpieces, having a workpiece support for mounting the workpiece, a tool holder, which can be moved at least along one axis, for holding a tool for machining the workpiece, and workpiece holding units for fixing the workpiece during the machining, the workpiece holding units being arranged outside the workpiece support surface of the workpiece support, which is covered by the workpiece in the mounted state, and each having a holding element for fixing the workpiece. In order that also workpieces of greater diameter can be machined, the machine tool otherwise being of the same dimensions, it is provided according to the invention that the holding elements can each be moved, substantially parallel to the workpiece support surface, in the direction of the workpiece, in particular in the direction of a central workpiece axis, which runs perpendicular to the workpiece support surface, for the purpose of centering and fixing the workpiece.

Abstract: The disclosure relates to a method for commissioning pneumatically operated actuators that are controlled by a positioner. To determine the drive type, a constant flow of pneumatic fluid is applied to the actuator during commissioning while a drive-specific characteristic curve of the fed back position is recorded over time. Then the measured characteristic curve is compared with a given specimen characteristic curve. The drive type is inferred from the level of difference or agreement between the drive-specific characteristic curve and the specimen characteristic curve.

Abstract: A method of dialing a workpiece having an axis into a chuck includes providing a chuck assembly having a plurality of independent hydraulically controlled jaws distributed about a central axis, each jaw having first and second hydraulic chambers. The method further includes the steps of inserting a portion of the workpiece into the chuck assembly, pumping hydraulic fluid uniformly into each of the first chambers until the jaws are substantially touching the perimeter of the workpiece, and adjusting one or more of the jaws to align the axis of the workpiece with the central axis of the chuck assembly by pumping hydraulic fluid into at least one of the chambers of at least one of the jaws. The method also includes the step of pumping hydraulic fluid uniformly into each of the first chambers until the jaws are clamped around the perimeter of the workpiece at a predetermined pressure.

Abstract: A machining apparatus has a chuck rotatable about an axis and having radially displaceable and angularly spaced jaws, a double-acting cylinder having a piston flanked by a pair of separate compartments and operatively connected to the jaws for radially shifting same. One of the compartments is pressurized with a working pressure pressing the jaws against a tool or workpiece and the other of the compartments with a counterpressure opposite to the working pressure. An instantaneous rotation speed of the chuck is detected, and a pressure differential between the working and counterpressures is varied in accordance with the detected instantaneous rotation speed.

Abstract: A piston is displaced by a pressure fluid supplied to a chuck body, whereupon a pair of first and second fingers that constitute a gripping member are operated to open and close along a base body. Further, a shaft-shaped bobbin is inserted through the interior of the first and second fingers, and a coil is wound around a small diameter portion of the bobbin. Accompanying opening/closing operations of the first and second fingers, an opening/closing amount thereof is detected based on a change in impedance of the coil.

Abstract: A method of dialing a workpiece having an axis into a chuck includes providing a chuck assembly having a plurality of independent hydraulically controlled jaws distributed about a central axis, each jaw having first and second hydraulic chambers. The method further includes the steps of inserting a portion of the workpiece into the chuck assembly, pumping hydraulic fluid uniformly into each of the first chambers until the jaws are substantially touching the perimeter of the workpiece, and adjusting one or more of the jaws to align the axis of the workpiece with the central axis of the chuck assembly by pumping hydraulic fluid into at least one of the chambers of at least one of the jaws. The method also includes the step of pumping hydraulic fluid uniformly into each of the first chambers until the jaws are clamped around the perimeter of the workpiece at a predetermined pressure.

Abstract: A rotary machine element has at least one functional part performing movements into stop positions, which stop positions are nominal stop positions or mechanical terminal stop positions and are functionally correlated. At least one position sensor is provided for detecting individual actual position values of the stop positions independently from one another. At least one position sensor is located in a control path between the at least one functional part and an NC control. The control path is active in positions between the nominal stop positions; the mechanical terminal stop positions; or the nominal stop positions and the mechanical terminal stop positions. Based on acquired actual position values of the at least one functional part, the speed and acceleration of the at least one functional part are determined by NC-control.

Abstract: An integrated power chuck assembly for a lathe has a hollow lathe spindle of a diameter sufficient to accommodate at least the actuating cylinder and a multiple medium feed device and preferably at least part of the stroke-control device which can include at least one sensor for the position of the piston.

Abstract: A graduated rotation control chuck assembly includes a base, a holding-down rod axially slidably mounted in the base, and a graduated rotation control unit, the graduation unit including a rotary shaft, mounted in the base and axially aimed at the holding-down rod to hold with the holding-down rod the workpiece to be processed, the rotary shaft having a first contact portion and a second contact portion, a first piston rod, and a second piston rod axially inserted through the first piston rod and mounted with the first piston rod in the base and being alternatively reciprocated against the first contact portion and second contact portion of the rotary shaft to rotate the rotary shaft step by step at a fixed angle per step.

Abstract: A work piece holder with clamping and rotation mechanisms in a support. A holder or brake exists next to a collet and sleeve assembly to restrain the assembly from rotating. Hydraulic pumps and connections operate on the mechanisms for the clamping and rotating actions. An electronic controller is connected with the mechanisms and operates the system in a sequence for selective machining on the work pieces.

Abstract: A stroke first air cylinder mechanism having a larger-diameter first piston and a larger-diameter first rod is incorporated in a casing, a chuck second air cylinder mechanism having a smaller-diameter second piston and a smaller-diameter second piston and a smaller-diameter second rod is coaxially incorporated into the first air cylinder mechanism, a base end portion of the second rod projects from the first piston and extends to such a position as to face a position detecting portion of the casing, a magnet is mounted to the base end portion of the second rod, and magnetometric sensor is mounted to the position detecting portion. By detecting an operating position of the second rod, opening and closing positions of jaw members can be detected.

Abstract: A method and apparatus for controlling a motor-driven chucking device which are capable of delicately controlling the workpiece gripping force, the travel speed of gripping jaws, and so forth. The method controls a motor-driven chucking device in which gripping jaws of a chuck provided on a main spindle rotatably supported by a headstock of a machine tool are opened or closed by a torque controllable driving motor to grip a workpiece. The method includes the steps of inputting a set value for gripping force with which the gripping jaws grip the workpiece, and opening or closing the gripping jaws by controlling rotation of the driving motor according to the set value for the gripping force.

Abstract: A chuck assembly has an actuator cylinder centered on and rotatable about an axis but substantially nondisplaceable relative to the axis, a chuck housing spaced axially from the cylinder, and a tubular connecting shaft extending along the axis and connected fixedly between the cylinder and the chuck housing so that the cylinder, connecting shaft, and chuck housing rotate jointly about the axis but do not move along the axis. A chuck piston axially displaceable in the chuck housing has an inner end turned axially toward the actuator cylinder. An actuator piston is similarly axially displaceable in the cylinder. The two pistons are connected together by a shaft assembly that has an actuator shaft fixed to the actuator piston and having an outer end and a chuck shaft having an inner end connected to the actuator-shaft outer end and an outer end connected to the chuck-piston inner end.

Abstract: An integrated power chuck assembly for a lathe has a hollow lathe spindle of a diameter sufficient to accommodate at least the actuating cylinder and a multiple medium feed device and preferably at least part of the stroke-control device which can include at least one sensor for the position of the piston.

Abstract: A rotary chuck having a chuck body supporting a plurality of clamping jaws for movement between open and closed positions and defining a cylindrical piston chamber containing an axially movable double acting piston coupled to a jaw actuator. A plurality of springs contained within the piston chamber apply biasing force to the piston in one axial direction to urge the jaws toward closed positions. An incrementally adjustable pneumatic control system is operable to apply pressure to the piston in opposition to the springs to reduce the resultant clamping force applied by the jaws in closed position. The control system is also operable to act in consort with the springs to increase the resultant clamping force applied by the jaws in closed position.

Abstract: A method is disclosed of controlling a hydraulic chuck of a rotary machine tool, the chuck clamping a workpiece to be machined and being actuated by a double-acting clamping/unclamping actuator. A clamping pressure controlled in accordance with a clamping pressure set point is applied to at least one chamber of the actuator and the clamping pressure is maintained in the corresponding chamber if the control pressure upstream of the actuator suddenly falls due to a malfunction. The clamping pressure is controlled by a closed loop and is modified in the chamber to disable the aforementioned maintaining of the pressure for a predetermined time period in response to an operator request to modify the clamping force applied to the workpiece. The disabling is being at least equal to the time necessary for the control system to stabilize.

Abstract: A plurality of clamping motion elements with clamping jaws are moved out of an initial position towards a workpiece under a low operating pressure and caused to bear thereagainst. When all the clamping jaws bear uniformly against the workpiece, a full clamping pressure is applied to clamp the workpiece fast in position.