Toyoda Koki Kabushiki Kaisha

Toyota Shatai Kabushiki Kaisha

Norio Ohta

Toshio Tsujiuchi

Takao Yoneda

Yukio Oda

Hisashi Nakamura

Masatomo Yoshimura

Kunihiko Unno

Yoshio Wakazono

Yasuji Sakakibara

Toshiaki Naya

Tomoyasu Imai

Hiroaki Asano

Ikuo Suzuki

Toshio Maruyama

Kenichi Munekata

Ryohei Mukai

Takayuki Yoshimi

Atsushi Kamiya

Yasuo Suzuki

Tomoyuki Kasuga

Tadashi Yamauchi

Hiroshi Nakano

Osamu Shibuki

Hitoshi Akabane

Yoichi Umemura

Tadashi Ogasawara

Noboru Matsuyama

Nobuhiro Ishihara

Yasuyuki Sato

Yoshinobu Yotsui

Masayuki Seki

Kouichi Isomura

Takaya Fujii

A method and apparatus for grinding a cylindrical surface of a workpiece by a traverse movement of a grinding wheel having a relatively narrow grinding surface. To improve the cylindricity of cylindrical surface, the traverse grinding is divided into a rough traverse grinding and a finish traverse grinding. In the rough traverse grinding, a traverse girding is carried out with a large depth of cut which would causes a deterioration of the cylindricity at one end of the cylindrical surface. In the finish traverse grinding, a traverse girding is carried out with a small depth of cut to improve the cylindricity. In another embodiment, one of grinding conditions such as the traverse speed of the grinding wheel, the rotational speed of the workpiece and the peripheral speed of the grinding wheel is changed when the grinding wheel approaches an end of the cylindrical surface at which the traverse grinding ends so as to make the grinding force constant, thereby improving the cylindricity of the cylindrical surface. In other embodiments, the position of the wheel head is compensated based upon the measured diameter of the cylindrical surface so that the entire area of the cylindrical surface has a desired diameter. This compensation also improves the cylindricity of the cylindrical surface.

Method and apparatus for grinding a cylindrical surface of a workpiece

A machine for grinding a cylindrical surface and the end surface of a shoulder portion, both formed on a workpiece, using an angular grinding wheel. The end surface is perpendicular to the cylindrical surface. The grinding wheel has a first outer surface parallel to the axis of the workpiece and a second outer surface perpendicular to the first outer surface. The first outer surface has a cylinder-grinding parallel surface and a cylinder-grinding tilted surface. The parallel surface has a generatrix parallel to the generatrix of the cylindrical surface to be ground. The tilted surface is continuous with the parallel surface and has a generatrix tilted away from the generatrix of the cylindrical surface. The second outer surface has a shoulder-grinding parallel surface and a shoulder-grinding tilted surface continuous with this parallel surface. The shoulder-grinding parallel surface has a generatrix parallel to the end surface of the shoulder portion. The shoulder-grinding tilted surface has a generatrix tilted away from the end surface of the shoulder portion. The grinding wheel is fed into the shoulder portion from a given position located radially inside the end surface. Then, the wheel is moved radially outwardly to grind the end surface. Subsequently, the wheel is moved relative to the workpiece along the generatrix of the cylindrical surface away from the end surface to grind the cylindrical surface.

Method and machine for grinding

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 having an angular type grinding wheel and a dressing apparatus therefor. The grinding wheel is formed with first and second grinding surfaces usable for grinding a cylindrical surface and shoulder end surface of a workpiece, respectively, and first and second reference surfaces parallel to the first and second grinding surfaces, respectively. The positions of the first and second reference surfaces and the first and second grinding surfaces are detected with touch bars before each dressing operation so as to obtain a first distance between the first grinding surface and first reference surface, and a second distance between the second grinding surface and second reference surface. After that, a first dressing amount for dressing the first grinding surface and a second dressing amount for dressing the second grinding surface are so determined that the first distance and the second distance would have a predetermined constant relationship after dressing operation. The first grinding surface is then dressed by the first dressing amount, while the second grinding surface is dressed by the second dressing amount.

Method and apparatus for dressing an angular grinding wheel

An apparatus for measuring groove positions of a workpiece includes a sensor for detecting grooves formed on the workpiece and a position sensor for detecting angular position of the workpiece with respect to a predetermined standard position, a measuring cycle memory means for storing several predetermined measuring cycles, a data input means for imputting and storing groove data indicating groove shape, a measuring control means for selecting a specific measurement cycle from the measurement cycle memory means based on the groove data to execute selected measurement cycle, a calculation processing means for executing calculation processing for determining the center positions of grooves, and a data output means for outputting and displaying the results of the calculations in order to inform an operator of the center positions of the grooves.

Apparatus for measuring groove positions of a workpiece

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

A numerical control grinding machine, in which rough grinding and finish grinding wheels are used to machine a workpiece into a predetermined shape. A sensor detects the finish grinding wheel contacting the workpiece surface when shifting from the rough grinding to finish grinding operations and determines its position. The numerical controller of the grinding machine calculates the difference between actual and theoretical sizes of the workpiece and completion of the rough grinding operation based on the finish grinding wheel position. After that, the controller compensates the rough grinding wheel position in the next machining cycle for the difference calculated by the controller.

Numerically controlled grinding machine

A numerically controlled internal grinding machine for grinding a workpiece by a rough grinding operation with a rough grinding wheel and a finish grinding operation with a finish grinding wheel. The grinding machine detects the load power of a motor which drives the finish grinding wheel in order to determine a compensation value to enable subsequent compensation due to wear of the rough grinding wheel. In the successive rough grinding operation, the relative position of the workpiece is compensated for according to the determined compensation value, so that the diameter of the workpiece after the rough grinding operation is maintained at a desired constant value regardless of the wear of the rough grinding wheel.

A numerically controlled machine tool for machining a non-circular workpiece according to profile data. The numerical controller stores phase compensation values and position compensation data files in connection with the types of cam and the various rotational speeds of the main spindle. Each position compensation data file consists of a series of position compensation values for a successive rotational positions of the main spindle. The numerical controller searches a phase compensation value and a position compensation data file according to the type of cam to be ground and the rotational speed of the main spindle during the grinding operation. Thereafter, the numerical controller offsets the read-out position of the profile data by the amount corresponding to the searched phase compensation value, and compensates each profile data with position compensation data stored in the searched file so as to eliminate a machining error which changes depending upon the rotational speed of the main spindle.

Numerically controlled machine tool

A numerically controlled machine tool for machining a non-circular workpiece according to profile data. The servomotor drive unit of the machine tool includes a frequency voltage converter which outputs a velocity compensation signal proportional to the frequency of position command pulses in the servomotor drive units. A position error signal is modulated by the velocity compensation signal. The numerical controller of the machine tool can measure the position error and phase error, and can compensate for these errors. The numerical controller operates according to ideal profile data and measures the actual position change of a tool slide corresponding to the angle position change of a main spindle. Then, the numerical controller calculates the position error and phase error depending on the actual position change and ideal profile data, and produces execution profile data which are compensated for position error. During machining operation, the numerical controller offsets the rear out position of the execution profile data by the calculated phase error so as to eliminate the phase error.

A numerically controlled grinding machine provided with an angular type grinding wheel and a numerical controller for controlling the feed of grinding wheel based upon a control signal from a measuring head which measures the diameter of a cylindrical side of a workpiece. The grinding wheel is moved along an inclined path to grind the cylindrical side and a radially inner portion of the shoulder of the workpiece, simultaneously. In response to the control signal from the measuring head, the feeding of the grinding wheel is stopped. Then, the numerical controller detects the difference between a target position and a actual position of the grinding wheel along an axis of a work spindle. Further, the numerical controller compensates another target position to grind the radially outer portion of the shoulder for the difference. Thereafter, the grinding wheel is moved to the compensated target position so as to grind the radially outer portion of the shoulder.

A numerical control apparatus which controls a grinding machine that includes a work table for supporting a workpiece, a grinding wheel and a truing device for truing the grinding wheel. The workpiece has taper and non-taper portions to be ground. The numerical control apparatus includes first and second storage means for storing first and second truing programs which respectively define first and second relative movements between the truing device and the grinding wheel to form a taper grinding surface and a non-taper grinding surface on the grinding wheel. The numerical control apparatus executes the first truing program prior to grinding the taper portion of the workpiece and also executes the second truing program after grinding the taper portion.

Numerical control apparatus for grinding machine capable of grinding

An interactive data input device for a numerical control grinding machine is provided with a key board for inputting data which defines the shapes of a number of machining portions formed on a cylindrical workpiece and a central processing unit for controlling a display controller to display on a screen of a cathode ray tube (CRT) display unit the profile as taken along the workpiece axis, of each machining portion based upon the shape data input by the key board. The central processing unit is programmed to display, in addition to the profiles of the machining portions, the profile of a non-machining portion formed between two machining portions based upon the shape data for the two machining portions.

Data input and display device for a numerical control grinding machine

A numerically controlled grinding machine equipped with two registers in which data concerning the positions of the cylindrical and shoulder grinding surfaces of a grinding wheel is stored. A reference point is established on the wheel spindle stock. A reference member having two reference surfaces is disposed on the worktable. The machine further includes a manual pulse generator for moving the grinding wheel head and the worktable, detectors for detecting the distances traveled by the wheel head and the worktable, a data entry device, an arithmetic processing unit, and a memory.

A suspension device for a vehicle seat has a lower frame secured to a vehicle floor, an upper frame disposed above the lower frame in parallel for mounting the vehicle seat, link plates disposed in parallel on the front side and the rear side of a vehicle for connecting the lower frame and the upper frame, torsion springs disposed near the connecting portion of the link plates for imparting elastic support force to the link plates, and a shock absorber disposed between the lower frame and the upper frame for damping the relative vibration of the above two frames.

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Okazaki, Japan

Norio Ohta