247 results about "Thermal displacement" patented technology

A position command value is compensated by predicting a thermal displacement amount of each part of a machine tool and adding a thermal displacement compensation amount which cancels the predicted thermal displacement amount to the position command value of a feed axis. This thermal displacement compensation amount is adjusted from the error amount between this compensated position command value and an actual machining point. Upon adjustment of this thermal displacement compensation amount, it is possible to determine whether to increase or decrease the thermal displacement amount based on a direction in which an operator moves a tool image or a workpiece image on a screen.

In a radiation detecting device having a sensor panel in which a plurality of photoelectric conversion elements are formed on one surface of a support substrate, a moisture-proof protective layer is laminated on a surface of the sensor panel on which the photoelectric conversion elements are formed, and a warp correction layer is laminated on the other surface of the sensor panel, and the moisture-proof protective layer and the warp correction layer are formed of a resin film having a drawing or extrusion direction, respectively, and bonded together so as to make the drawing or extrusion directions of both the resin films similar to each other. With the formation of the radiation detecting device, the warp of the radiation detection panel induced by a thermal displacement is prevented.

A structural attachment system for the outlet of a transition duct includes a structural attachment member that has a step over portion with an outer flange at one end thereof and an inner flange at the other end thereof. The step over portion can project away from the inner and outer flanges and can define an open area. The step over portion can have a cross-section that is generally u-shaped, v-shaped, c-shaped, semi-circular, semi-oval, parabolic, or bowed. A portion of the outlet of a transition duct is received within the step over portion of the structural attachment member. Because of such arrangement, the structural attachment member is not constrained circumferentially to fitting in between two neighboring transition ducts. The structural attachment member can manage the thermal displacements that can occur between the transitions, rotor shaft cover and first row of blades during transient engine operation.

The invention relates to a selection method of numerically-controlled machine tool thermal error compensation temperature sensor measuring point positions. The influence of temperature measuring points at all positions on a machine tool thermal error is identified on the basis of a main factor strategy and a weight product method theory. The method comprises the specific steps that firstly, k temperature sensors are arranged at special positions of a machine tool to measure the real-time temperature values, changing along with the time, in running of the machine tool, and meanwhile thermal displacement of a main shaft arranged on a tool rest is recorded; secondly, part of temperature measuring point positions are removed according to the main factor strategy; thirdly, a BP neural network model capable of simulating changes of the thermal error is built; fourthly, the weight product method is utilized for identifying the influence of remaining measuring point positions. According to the method, the problem that in the process of numerically-controlled machine tool thermal error compensation modeling, the temperature measuring points are too many or the robustness of the compensation model is poor is solved. According to the method, temperature measuring modeling with the fewest temperature sensors is utilized for predicating the error generated by dynamic thermal deformation of the numerically-controlled machine tool, the number of the machine tool temperature measuring points is reduced, and cost is saved.

In a machine tool controlled by using a numerical control device, a correction amount is determined for thermal displacement due to heat generation and heat conduction in a spindle motor and a feed shaft motor, in addition to thermal displacement due to heat generated by rotation of a spindle and a feed shaft. A tool position is corrected based on the correction amount. An entire stroke of the feed shaft is divided into a finite number of sections, and for each section, a correction amount for thermal displacement due to axial movement of the feed shaft is determined. The tool position is corrected based on the determined correction amount.

A thermal displacement compensating device calculates a thermal displacement amount which is produced by heat generation or dissipation as a machine tool is actuated or stopped and changes with time. A thermal displacement compensation amount is calculated by multiplying the calculated thermal displacement amount by a coefficient. A position command is compensated by adding the thermal displacement compensation amount to the position command. On the other hand, a variation between a thermal displacement amount calculated last time and a current thermal displacement amount is determined for each predetermined time. A plurality of thermal displacement amount change states are identified based on comparison between the determined variation and a predetermined threshold. The coefficient is calculated based on the identified thermal displacement amount change state.

A thermal displacement correction method includes the steps of: presetting the coordinate data of a fixed position of the workpiece on a table; finding an amount of displacement of the fixed position of the workpiece at a current cutting edge position based on the detected temperature, the coordinate data of the cutting edge position, and the coordinate data of the fixed position; computing the difference in the coordinate data between the fixed position of the workpiece and the cutting edge position; finding an amount of displacement of the workpiece between its fixed position and the cutting edge position based on the detected temperature and the difference in the coordinate data between the fixed position and the cutting edge position, and computing a sum of each amount of displacement to define an estimated value and correcting thermal displacement using an NC unit based on the estimated value.

A machine tool and a method of correcting the displacement of the machine tool. The machine tool comprises temperature sensors (28 to 36) installed on a machine tool body (11, 41) at a plurality of positions, a displacement amount detection means (25) detecting the thermal deformation amounts of components (12 to 15) based on measurements by the temperature sensors (28 to 36) and in considerationof the warpages thereof caused due to the temperature changes of their surfaces with large temperature changes and their surfaces positioned on the opposite side thereof, a conversion means (25) converting the thermal displacement amounts of the components (12 to 15) detected by the displacement amount detection means (25) to their axial displacement amounts at working points (P), and a correction means (25) correcting the relative movement amounts on the axes of the components according to the conversion by the conversion means (25).

The invention discloses a macro-micro dual-drive combined machining center which has a skid and rotation joint portion with thermal walking constraint, comprising a lathe body, upright posts, beams, X-axis parts, swing B-axis parts, rotation C-axis parts, a two-axes paralleling mechanism, a milling electro-spindle, Y-axis parts, Z-axis parts and a lapping-polishing electro-spindle, wherein the two-axes paralleling mechanism realizes the movement of a virtual W axis and a virtual V axis by adopting dual drive, a micro-drive actuator deforming guide way is adopted between a macro-micro dual-drive macro-motion table and a macro-micro dual-drive micro-drive table, the X-axis parts, the Y-axis parts and the two-axes paralleling mechanism movement pairs adopt combined slide seats which are combined by a cast iron working slide seat, a thermal walking constraint joint portion and a granite bearing slide seat, and the B-axis, the rotation C-axis and the two-axes paralleling mechanism rotation pairs adopt skid and rotation joint portion mechanisms. The combined machining center has a combined machining function that the five axes of X, B, C, V and W are interlinked so as to mill the complex moulding surfaces of hard parts at high speed and the five axes of X, B, C, Y and Z are interlinked so as to lap and polish the complex moulding surfaces of hard parts with high accuracy.

The invention provides a thermal displacement compensation method for a machine tool and a thermal displacement compensation device. In the thermal displacement compensation method for the machine tool, in which a feed shaft thermal displacement amount is obtained and an amount which cancels the obtained feed shaft thermal displacement amount is added as a thermal displacement compensation amount to a position command for a feed axis, a position where a signal is first output by a position sensor for detecting the position of a movable part of the machine tool is first stored as an initial position. Then, the position where the signal is output by the position sensor is detected, and the thermal displacement compensation amount is modified according to a compensation error, which is the difference between the detected position (actual position) and the initial position.

A thermal displacement element comprises a substrate, and a supported member supported on the substrate. The supported member includes first and second displacement portions, a heat separating portion exhibiting a high thermal resistance and a radiation absorbing portion receiving the radiation and converting it into heat. Each of the first and second displacement portions has at least two layers of different materials having different expansion coefficients and stacked on each other. The first displacement portion is mechanically continuous to the substrate without through the heat separating portion. The radiation absorbing portion and the second displacement portion are mechanically continuous to the substrate through the heat separating portion and the first displacement portion. The second displacement portion is thermally connected to the radiation absorbing portion. A radiation detecting device comprises a thermal displacement element and a displacement reading member fixed to the second displacement portion of the thermal displacement element and used for obtaining a predetermined change corresponding to a displacement in the second displacement portion.

A method corrects thermal displacement of a machine tool having a rotational spindle. The method includes detecting a rotation speed of the spindle. A thermal displacement amount of the spindle in the current cycle of execution of a program is estimated by using an arithmetic expression that is based at least on the spindle rotation speed and a thermal displacement amount that has been estimated in the preceding cycle of execution of the program. The estimated thermal displacement amount in the current cycle is used as a correction amount for canceling the thermal displacement of the spindle. Therefore, thermal displacement of a machine tool is corrected with no complicated processes when a spindle rotation speed changes.

In the magnetic disk unit comprising suspensions in each of which an IC is mounted on a load beam, a magnetic head displacement caused by the warp of the load beam occurring due to heat generated from the IC is compensated, whereby the shortening of an access speed and high reliability of reading / writing are realized. The thermal displacement of the magnetic head is compensated by operating micro actuators on the load beam in accordance with the temperature rise of the IC which is measured by a temperature sensor. Namely, by driving the micro actuators so that the magnetic head may move in a direction reverse to the direction of the magnetic head movement caused by the thermal displacement, the thermal displacement of the magnetic head is made to be substantially zero.

In a radiation detecting device having a sensor panel in which a plurality of photoelectric conversion elements are formed on one surface of a support substrate, a moisture-proof protective layer is laminated on a surface of the sensor panel on which the photoelectric conversion elements are formed, and a warp correction layer is laminated on the other surface of the sensor panel, and the moisture-proof protective layer and the warp correction layer are formed of a resin film having a drawing or extrusion direction, respectively, and bonded together so as to make the drawing or extrusion directions of both the resin films similar to each other. With the formation of the radiation detecting device, the warp of the radiation detection panel induced by a thermal displacement is prevented.

Kinematic parameters of a parallel kinematic machine can be estimated with high precision considering thermal displacement and error of a measuring device, in addition to deformation error caused by self-weight of each component. A DBB device is used when end effectors of a parallel kinematic mechanism machine are positioned at plural positions and in plural postures. In the DBB device, a plurality of support bars are provided with rigid balls on the both ends. One of the balls is fixed on a table and the other ball is provided with an end effector. The position, posture, and distance from a fixed position are measured and based on the measured value kinematic parameters are estimated. In estimating the kinematic parameters, any of deformation error caused by self-weight of each component, thermal displacement of each component, error of a measuring device are added for computation by linear approximation.

Prior to machining a workpiece, a warm-up control device for a machine tool is activated to perform a warm-up in which a main shaft rotary drive part and axes drive parts are driven. The amount of displacement of heat that is generated upon starting of the warm-up and changes with time is calculated every predetermined time period. Whether to end the warm-up is determined based on the thermal displacement amount. Whether to restart the warm-up after the end of the warm-up is determined based on the thermal displacement amount. When it is determined to restart the warm-up, the warm-up is restarted.

The invention discloses a system for measuring the thermal error of a precise numerically-controlled machine tool and compensating temperature, and belongs to the technical field of numerically-controlled machine tool temperature compensation. The system comprises a thermal error measuring system, a programmable logic controller, a numerical control unit, and a temperature-compensating system. The thermal error measuring system comprises a plurality of inductive displacement sensors, a plurality of temperature sensors, and a signal filter. The temperature-compensating system comprises a temperature-compensating unit, a position-adjusting module, and a data-computing unit. The numerical control unit comprises a correction module, a temperate compensation computing module, a numerically-controlled machine tool interpolation module, a temperature-acquiring module, and a numerically-controlled machine tool position control module. The temperate compensation computing module computes the temperature compensation value of a corresponding shaft of the machine tool at a certain time. The numerically-controlled machine tool position control module enables the shaft to backwardly move if the temperature compensation value is a positive value, or enables the shaft to forwardly move if the temperature compensation value is a negative value. The system is high in measurement precision and may simultaneously acquire the thermal displacement and the temperature difference of the numerically-controlled machine tool.

The present invention provides a thermal displacement correcting method of a machine tool and a thermal displacement correcting device, which is used to correct error caused by thermal displacement of a ball screw mechanism generated in operation of a machine tool. A first heat productivity computing division calculates a first heat productivity generated by a nut on a screw axis according to a rotary speed detected by a speed detector; a second heat productivity computing division calculates a second heat productivity generated by a servo motor on a screw axis according to a temperature increase detected by a temperature detecting division. A temperature distribution computing division calculates the temperature distribution that separated into a plurality of zones in length direction of the screw axis. A thermal displacement quantity computing division calculates thermal displacement quantity of each zone according to temperature distribution calculated by the temperature distribution computing division. A correction computing division calculates a correction of machining data for nut feed calculation according to the thermal displacement quantity calculated by the thermal displacement quantity computing division.

The invention relates to a control method for the thermal deformation compensation of a ram of a numerical control machine and a device for implementing the same, which mainly solve the problem of machining error caused by flexible deformation due to the change of the ram of the numerical control machine with the change of temperature. The control method is characterized in that: a micrometric displacement detection device which has low thermal expansivity and is fixed on the ram is adopted, and one end of a displacement reference measuring rod in the micrometric displacement detection device extends freely and forms a thermal displacement measuring factor with a micrometric displacement sensor; a thermal deformation flexible signal, which is detected by the micrometric displacement detection device, of the ram is processed and converted by an embedded compensator to form two paths of orthogonal pulse signals; the orthogonal pulse signals are generated by a method of controlling a quarter of the period of the signals, and is inputted to a numerical control system by a hand-held unit interface of the numerical control machine; and the system performs real-time compensation by calling a fine motion differential analyzing function. After the control method is used, the machining error caused by thermal deformation in the ram of the numerical control machine can be reduced greatly, so the control method has the excellent economic and social benefit.

A thermal displacement correction device for a machine tool is provided with detection result determination unit configured to determine, based on an actual position and a reference position detected by position detection unit, whether or not the actual position is based on correct detection, correction error calculation unit configured to calculate a correction error in the actual position if it is determined that the result of detection is based on correct detection, and correction amount modification unit configured to modify a thermal displacement correction amount based on the correction error.

A radiation detector comprises an infrared radiation sensing micro mirror array, where each micro mirror is supported with a deformable cantilever beam having an organic layer for increased dynamic range. The radiation detector includes two or more sources of optical radiation for irradiating the micro mirror array, an image sensor array for receiving optical reflection from the micro mirror array, and an aperture plate for (i) spatially restricting optical radiation reaching the micro mirror array and (ii) spatially restricting reflected optical reflection reaching the image sensor array.

A sensor assembly includes: a base with an installation space; an electrical connection member disposed on the base; a sensing unit including at least two physical sensors and one integrated circuit board; and a contact member disposed at one end of the base. The sensor assembly is a combination of the temperature sensor and the vibration sensor, the main physical parameters (including back clearance, collision, thermal displacement and lubrication) regarding the operation of the linear motion transmission device can be calculated based on the temperature signal and vibration signals, without requiring the installation of separate different sensors. Therefore, installation space is reduced. The sensor assembly is directly abutted against the linear motion transmission device to detect the change of various physical values in a most direct manner.

A thermal displacement element comprises a substrate, and a supported member supported on the substrate. The supported member includes first and second displacement portions, a heat separating portion exhibiting a high thermal resistance and a radiation absorbing portion receiving the radiation and converting it into heat. Each of the first and second displacement portions has at least two layers of different materials having different expansion coefficients and stacked on each other. The first displacement portion is mechanically continuous to the substrate without through the heat separating portion. The radiation absorbing portion and the second displacement portion are mechanically continuous to the substrate through the heat separating portion and the first displacement portion. The second displacement portion is thermally connected to the radiation absorbing portion. A radiation detecting device comprises a thermal displacement element and a displacement reading member fixed to the second displacement portion of the thermal displacement element and used for obtaining a predetermined change corresponding to a displacement in the second displacement portion.

In a thermal displacement compensation method for a machine tool, in which a feed shaft thermal displacement amount is obtained and an amount which cancels the obtained feed shaft thermal displacement amount is added as a thermal displacement compensation amount to a position command for a feed axis, a position where a signal is first output by a position sensor for detecting the position of a movable part of the machine tool is first stored as an initial position. Then, the position where the signal is output by the position sensor is detected, and the thermal displacement compensation amount is modified according to a compensation error, which is the difference between the detected position (actual position) and the initial position.

The purpose of the present invention is to provide a system for correcting thermal displacement of a machine tool, said system being capable of evaluating the amount of thermal displacement with a column front face serving as a reference position, and being capable of performing thermal displacement correction with good precision even when the amount of thermal displacement of a table is not uniform. For this purpose, the system is provided with, for example: a position detector temperature sensor (41-6); table temperature sensors (41-1 to 41-5); and a displacement correction device. The displacement correction device comprises: a temperature data input section for inputting temperature data (a6); a thermal displacement amount calculation section for calculating the amount of thermal displacement of the position detector on the basis of the temperature data (a6); a temperature data input section for inputting temperature data (a1 to a5); a thermal displacement amount calculation section for calculating, on the basis of the temperature data (a1 to a5), the amount of thermal displacement of the table corresponding to a temperature distribution in the X axis direction; a thermal displacement amount calculation section for calculating the amount of thermal displacement of the table system with the column front face serving as the reference position, said calculation being performed on the basis of the amount of thermal displacement of the table and the amount of thermal displacement of the position detector; and an X axis correction amount output section for outputting an X axis correction amount on the basis of the amount of thermal displacement of the table system.

A thermal displacement correction method is provided, including the steps of presetting coordinate data for a fixed position of a workpiece on a table, finding an amount of displacement of the fixed position of the workpiece at a current cutting edge position based on the detected temperature, the coordinate data of the cutting edge position, and the coordinate data of the fixed position, and computing a difference in the coordinate data between the fixed position of the workpiece and the cutting edge position, finding an amount of displacement of the workpiece between its fixed position and the cutting edge position based on the detected temperature and the difference in the coordinate data between the fixed position and the cutting edge position, and computing a sum of each amount of displacement to define an estimated value and correcting thermal displacement using an NC unit based on the estimated value.

A method for compensating thermal displacements is carried out on a machine tool having a worktable for mounting workpieces to be machined, and having a tool spindle which can be traversed relative to the worktable on at least one axis and into which it is possible to clamp tools with the aid of which a machining process is carried out on the workpieces. In this case a calculating rule is used to calculate from at least one temperature value currently measured at a measuring point on the machine tool at least one correction value for the at least one axis. The calculating rule is tuned in this case to the respective machining process.

A thermal displacement compensation device detects the temperature of a machine tool and the temperature of an environment in which the machine tool is placed, and estimates a temperature distribution in a machine component affected by the temperature of the environment from the relationship between the temperature of the machine tool and the temperature of the environment. Based on the estimated temperature distribution in the machine component, a position in the machine tool at which the time constant of the detected temperature matches the time constant of thermal displacement of the machine component affected by the temperature of the environment is found and set. Using temperature at the set position as a revised temperature of temperature detected by the machine temperature detection section, a thermal displacement amount of the machine component is calculated.