Toyoda Koki Kabushiki Kaisha

Jtekt Corporation

Yoshio Wakazono

Norio Ohta

Masashi Yoritsune

Hisanobu Kobayashi

Toshihiko Shima

Yukio Oda

Tetsuro Furuhata

Yoshiji Yamamoto

Makoto Tano

Kozo Imanishi

Katsuhiko Takeuchi

Hideki Iwai

Kimihiro Onishi

Kazuo Machida

Yuji Sasaki

Wataru Iida

Yasumasa Sakurai

Fumitaka Achiwa

Eijii Kato

In a thermal displacement compensating device and a thermal displacement compensating method for a machine tool, a block temperature obtaining section obtains temperatures of respective blocks based on temperature information detected by temperature sensors wherein temperatures in each of the respective blocks into which a column is divided to be pluralized are defined as a uniform value. An FEM analysis section performs a structural analysis by a finite element method based on the temperatures of the respective blocks obtained by the block temperature obtaining section and infers thermal displacement amounts of the column. A compensation value calculation section calculates a compensation value for a machining command position based on the thermal displacement amounts of the column inferred by the FEM analysis section. A compensation section compensates the machining command position by the compensation value obtained by the compensation value calculation section.

Thermal displacement compensating device and method for a machine tool

A truing device of a grinding machine includes: a truer that corrects a shape of a grinding wheel; a swivel table that supports the truer such that the truer is swivelable about a swivel axis Ac; detecting means for directly detecting a distance from a truing edge position of the truer, which contacts the grinding wheel during correction of the shape of the grinding wheel, to a swivel center O of the swivel table; and control means for controlling the truing edge position of the truer with respect to the grinding wheel based on the distance L detected by the detecting means to true the grinding wheel.

Truing device of grinding machine

A core grinding wheel that has a grinding layer on an outer periphery of a core is used. An ultrasonic wave is output from an ultrasonic sensor to the grinding layer via grinding fluid. An ultrasonic measuring device control unit calculates a thickness of the grinding layer on the basis of a sonic velocity in the grinding layer and an arrival time difference between a reflected wave from a surface of the grinding layer and a reflected wave from a surface of the outer periphery of the core. A grinding process and a truing process are controlled on the basis of an outside diameter of the grinding wheel, which is calculated on the basis of the measured thickness of the grinding layer and an outside diameter of the core.

Grinding method for grinding a workpiece using a grinding wheel

Plural combined processing machines perform various processes to workpieces W. The combined processing machines are arranged in a processing line according to a volume of products of the workpieces, operating time of the combined processing machines and a tact time to complete processing one of the workpieces. Each combined processing machine is determined to share one or more processes according to the volume of the products, the operating time and the tact time. The workpieces are transferred among the combined processing machines to be processed.

Processing method of workpieces using combined processing machines

A linear motor actuated machine tool includes a bed, a column, upper and lower X-axis guides, a saddle, upper and lower X-axis linear motor magnets, and upper and lower X-axis linear motor coils. Upper and lower X-axis guides are attached to the upper and lower portion of front surface of the column, which is mounted on the bed in the vertical direction, in the horizontal direction. Upper and lower X-axis linear motor magnets is fixed on the front surface of the column at upper side and lower side of the upper and lower X-axis guides in the direction of X-axis with making pole surfaces thereof face to frontward. Upper and lower X-axis linear motor coils are fixed to upper end and lower end of the rear surface of the saddle, which is mounted on the front surface of the column with being guided by upper and lower X-axis guides and having a through space at the center portion thereof, with opposing to upper and lower X-axis linear motor.

Linear motor operated machine tool

In a grinding machine, a generally cylindrical workpiece having at least first and second grinding areas is ground by use of a grinding wheel supported by a wheel head. The first grinding area is first ground such that power consumed by the grinding machine is maintained at a first level. After completion of grinding for the first grinding area, the grinding wheel is indexed to the second grinding area by moving the wheel head such that the power consumed by the grinding machine is maintained at a second level higher than the first level. After completion of the indexing operation, the second grinding area is ground in the same manner as the first grinding area.

Grinding method and grinding machine

Disclosed is a cylindrical grinding machine of the type that a workpiece support device composed of a work head and a foot stock is mounted on a forward upper portion of a bed while a wheel head unit composed of a slide base and a wheel head is mounted on a rear upper portion of the bed. A coolant collecting vent which takes a rectangular shape as viewed from above vertically extends in the bed and opens to the upper surface of the bed to cover an area that extends from under the workpiece on the workpiece support device to under the forward portion of the wheel head unit. A horizontal vent is provided in the bed to open to the rear surface of the bed and to communicate with the collecting vent. A coolant supply device is inserted at a part thereof into the horizontal vent from the rear surface of the bed to extend an inlet opening into the collecting vent. In one embodiment, the slide base is mounted to straddle over the collecting vent and is guided at both ends thereof on the bed to be movable back and forth, and the wheel head is guided to be movable on the slide base in a right-left direction. In another embodiment, the part of the coolant supply device inserted into the horizontal vent is constituted as a discharge duct, from which a mist discharge duct branches upwardly to be connected to a mist collecting device. Airflow blocking means is provided for permitting the coolant to flow through but for blocking airflow from an outlet port of the discharge duct toward the mist discharge duct.

Cylindrical grinding machine

A pair of hydrostatic radial bearing devicesis mounted on right and left side surface of a front portion of a wheel slidein order to support rotatably wheel shaftsrespectively. A thrust bearing devicemounted in either one of wheel shaftssupports either wheel shaftorin a thrust direction. A shaft coupling mechanismis installed in wheel shafts. A taper cylindrical portionis projected from either one of wheel shaftsand fitted tightly with a taper inside openingformed in remaining of wheel shafts. A vertical end surfaceor Fb extending from a base of the taper cylindrical portionis fitted tightly with another vertical end surfaceorof the remaining wheel shaftor

Wheel shaft supporting apparatus for grinding machine

In a truing method and apparatus, an analyzing method is employed to calculate a truing shape from which a grinding surface having been trued with a grinding wheel being rotated at a low rotational speed during a truing operation is deformed to a desired shape due to centrifugal expansion depending on a rotational speed difference when the grinding wheel is rotated at a high rotational speed during a grinding operation. Then, with the grinding wheel being rotated at the low rotational speed, the grinding surface is trued with a truing roll to the calculated truing shape. As a result, the grinding surface of the grinding wheel being rotated at the low rotational speed is trued with the truing roll taking into consideration the centrifugal expansion of the grinding surface which takes place when the grinding wheel is rotatated at the high rotational speed during the grinding operation subsequent to the truing operation.

Truing method and apparatus

In a cylindrical grinding machine, a lateral surrounding cover is mounted on a bed and surrounds and covers lateral surfaces of a machining area in which a work support drive device, a grinding wheel and a bearing unit therefor are arranged and a slide area in which a base portion of a wheel head and a slide mechanism for the wheel head are arranged. A top open/close cover is further provided on the top portion of the lateral surrounding cover and is movable between a first position to open the upsides of the machining area and the slide area and a second position to cover the upsides of the machining area and the slide area. Thus, only by moving the top open/close cover to the first position, it becomes possible for an operator to look over the whole part of the machining area and the slide area. Since plural components of the grinding machine can be checked simultaneously with the top open/close cover opened, the time taken for maintenance or service work on the grinding machine can be shortened.

Grinding machine

A grinding head guiding apparatus is disclosed. The grinding head is driven by the linear motor which is constituted of a coil attached on an underside surface of the grinding head and a magnet attached on an upside surface. Horizontal guiding members are fixed on the base, and the grinding head is guided to the horizontal guide members. Then, a height of a portion opposing the coil and the magnet is approximately same as a height of the horizontal guide members guiding the grinding head. Besides, temporary supporting members are attached on the base so as to avoid sticking the coil to the magnet, when the coil is detached from the grinding head. Further, the grinding head has ribs therein, which define an approximately trapezoid-shaped space disposed a center of the grinding head and triangle-shaped spaces disposed both side of the trapezoid-shaped space.

Guiding apparatus for a slidable member driven by a linear motor

A machine tool is structured enhance rigidity of a slide member opposing to a cutting force acting on a tool spindle with no extra increase in weight, thereby intending to lighten the slide member. The machine tool comprises a tool spindle rotating around an axis extending along an Z-axis, a slide member slidable in at least one of the X-axis, Y-axis and Z-axis directions and a guide apparatus having a straight rail and movably supporting the slide member on the guide rail and disposed such that three supporting points for supporting the slide member form vertexes of a triangle as seen from the X-axis direction. Further, in another construction, two sets of linear guide mechanism and a linear motor for guiding each of an upper portion and a lower portion of a gantry are respectively disposed between a lower surface of the gantry and a base, and between a front surface of a cross beam and an upper back surface of the gantry, so that the cross beam does not lap over the upper surface of the gantry.

Machine tool

A method for detecting the coordinate position of the grinding point of a grinding wheel supported on a swiveling table comprises the steps of: rotating drivably the swiveling table through a specified angle from a start position so as to arrive at a first turning position; measuring a first displacement of the grinding point of the grinding wheel from the start position by displacement measuring means; rotating the swiveling table through the specified angle from the first turning position so as to arrive at a second turning position; measuring a second displacement of the grinding point of the griding wheel from the first turning position by the displacement measuring means; and calculating the position of the grinding wheel with respect to the swivel axis of swiveling table according to the first and the second displacement and the specified angle.

Method for detecting the coordinate position of the grinding point of a

A grinding machine for grinding outer and/or inner surfaces of a workpiece which is provided on its indexable wheel head with an outer surface grinding wheel, inner surface grinding wheel and a measuring device having a touch probe engagable with a reference surface of the workpiece. A numerical controller having a memory for memorizing data indicating positional and angular relationships between the outer surface grinding wheel, the inner surface grinding wheel and the touch probe is provided. The numerical controller first indexes the measuring device to a location facing the workpiece, and moves the workpiece along its rotational axis until the measuring device outputs a touch signal. After that, the numerical controller calculates a moving amount of the workpiece for an outer grinding operation based upon data memorized in the memory, and moves the table by the calculated amount in order to grind the outer surface of the workpiece. When a inner surface of a workpiece is machined, the inner grinding wheel is indexed to a position facing the workpiece based upon the data indicating angular relationship, after the workpiece is positioned based upon the touch signal from the measuring device. Thereafter, the table is moved based upon data indicating positional relationship between the inner surface grinding wheel and the touch probe in order to locate the inner surface grinding wheel to a predetermined grinding starting position of the inner grinding operation.

Grinding machine for grinding outer and inner surfaces

In a numerical control grinding machine using a grinding wheel made of cubic boron nitride, a computerized numerical controller controls the infeed movement of a wheel head to effect a rough grinding, a drifty grinding and a fine grinding on a rotating cylindrical workpiece. The drifty grinding due to a spring-back motion which is caused by a flexed workpiece is initiated in response to a sizing signal from a sizing device which measures the workpiece diameter varying momentarily during the grinding operation and is terminated upon the expiration of a predetermined time which is sufficient to vanish the variation of the workpiece diameter. A sizing device measures the actual diameter thereafter, and the sizing signal is compensated in order to approximate the actual diameter to a desired set size which is the sum of a finish diameter and a predetermined allowance for the subsequent fine grinding operation, as the number of the workpieces increases. That is, the numerical controller diminishes a set size which determines the time point to issue the sizing signal from the sizing device, toward the desired set size on a step-by-step basis with the increase in number of the workpieces ground.

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Nagoya, Japan

Yoshio Wakazono