Toyoda Koki Kabushiki Kaisha

Jtekt Corporation

Toshio Maruyama

Shoichi Sano

Tsuyoshi Koide

Hiroaki Asano

Toshio Tsujiuchi

Tadashi Yamauchi

Yuichiro Komatsu

Takao Yoneda

Norio Ohta

Yasuji Sakakibara

Masahiro Ido

Yukio Oda

Norihiko Shimizu

Makoto Nonoyama

Hiroshi Nakano

Yoshinobu Suzuki

Yasunori Ban

Shinji Nishio

Masayoshi Inoue

Hidetaka Irie

Taisuke Kawamata

Koichi Murayama

Masakazu Yamaguchi

Kenzaburo Oishi

Yukiharu Tsuchiya

Syoji Yamaguchi

Shigenobu Usutani

Nobuhiro Ishihara

A grinding wheel having a grindstone portion formed on a core includes slippery fluoroplastic coating films that prevent attachment of foreign matter, the coating films being provided on the portions of the core, with which portions the foreign matter can be brought into contact.

Grinding wheel

A spindle apparatus for supporting and rotating a workpiece in a grinder. The spindle apparatus includes a workpiece spindle rotatably supported on a spindle head and driven for rotation by a motor, and a spindle plate mounted to the front end of the workpiece spindle and including an eccentric drive pin. The workpiece spindle has a bore in which a ram is axially movable. A center is fit in the front end of the ram. A unit is provided to advance the ram to engage with one end of the workpiece when the workpiece is to be supported. A rotary sleeve is rotatably supported on the front end of the ram and includes an engagement portion which is displaceable in the axial direction of the spindle and engageable with the drive pin in the direction of rotation. A driving unit is mounted to the front of the rotary sleeve to engage the workpiece in the direction of rotation when the ram is in its advanced position to thereby transmit rotation.

Spindle apparatus for supporting and rotating a workpiece

A method for truing a grinding wheel having a non-straight cylindrical grinding surface. In truing operation, a truing tool is caused to contact different portions of the grinding surface, and relative position of the truing tool is detected when the truing tool contacts the respective portions. Then, a first portion rom which a largest amount of abrasive layer must be removed, and a second portion from which a smallest amount of abrasive layer must be removed are found out. Based upon the detected positions, the radial location of an initial truing start position and a truing operation end position are calculated. The truing tool is initially moved to the initial truing start position, and then traversed from the truing start position along a locus corresponding to a desired final shape of the grinding wheel. The radial location of the truing start position is then shifted in a direction of approaching to the rotational axis of the grinding wheel, and the traverse movement is repeated. When the radial location of the truing start position reaches or exceeds the truing operation end position, the truing operation is stopped.

Method and apparatus for truing a grinding wheel

An indexing mechanism in a machine tool for selectively positioning plural pin portions of a crankshaft at the machining position aligned with the work spindle, wherein a indexing member engaging with the crankshaft through an engaging pin is rotated by an indexing motor through a gear train. The crankshaft is initially rotated in a first direction until a selected pin portion engages with a rest shoe of a rest device provided on the bed in order to be positioned in a reference angle position, in which the selected pin portion is located at the machining position aligned with a work spindle. The crankshaft is then clamped on the chucking device. After that, the indexing motor is rotated in a second direction opposite to the first direction until the load of the motor exceeds a reference level, so that the influence of a backlash in the gear train and a clearance between the engaging pin and the crankshaft is eliminated. After the completion of a grinding operation on the selected pin portion, the indexing member is thereafter rotated in the second direction by a predetermined amount so as to position a next pin portion in the machining position.

Method and apparatus for angularly indexing a crankshaft

A truing apparatus for an angle grinding wheel with two grinding surfaces is provided with an AE sensor for detecting the contact of a truing tool with each of the grinding surfaces. The truing tool is provided on a follow slide which is mounted on a traverse slide. As the traverse slide is moved in a first direction, the follow slide is moved following a template in a second direction extending across the first direction. In response to a truing command, at each of first and second traverse positions in the first direction, the truing tool is advanced relative to the follow slide until a contact signal is issued from the AE sensor upon contact of the truing tool with a corresponding one of first and second grinding surfaces. A position sensor detects first and second feed positions at which the truing tool contacts the two grinding surfaces. One of the feed positions which is shorter in distance from the follow slide is selected to determine a truing start position. The truing tool is then moved to the truing start position and is traversed in the first direction while following the template in the second direction. It is ascertained whether the AE sensor continues to issue the contact signal during each traverse movement of the truing tool. The infeed movement and traverse feed movement of the truing tool are repeated until the continuous issuance of the contact signal during each traverse movement of the truing tool is confirmed.

Apparatus for truing grinding wheel

An apparatus for truing the cylindrical outer peripheral grinding surface of a grinding wheel includes a truing head which is movable toward or away from the grinding wheel in a first direction which is parallel to the grinding surface and in a second direction which is perpendicular to the first direction. A truing wheel is rotatably supported on the truing head, has a truing surface and is movable with the truing head for truing the grinding surface. A contacting detection member is secured to the truing head, projects therefrom toward the grinding surface and has an end surface which can be brought into contact with the grinding surface. A device is provided for detecting the contact of the end surface of the detection member with the grinding surface and producing an output signal upon detecting their contact. Three feed control devices are provided to move the truing head in various directions. Detecting devices and memories are provided for detecting the position of the truing head and for controlling movement of the head.

Apparatus for truing a grinding wheel

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.

Numerically controlled machine tool

A grinding method for grinding non-circular workpiece such as a cam. The grinding wheel is moved according to the profile data defining profile generating movement of grinding wheel and cut-in feed data defining cut-in feed movement of the grinding wheel. In a part of each revolution of the workpiece, where the acceleration of the profile generating movement become zero or a negative value, the profile generating movement according to the profile data and the cut-in feed movement according to the cut-in feed data are executed simultaneously. Then, in the remainder of each revolution, the profile generating movement is executed without cut-in feed. The above-mentioned process is repeated alternately until the total amount of cut-in feed reaches a predetermined value.

Method for grinding a non-circular workpiece

A method of successively grinding a plurality of cams on a camshaft by performing a grinding cycle for each of the cams after each cam is brought into alignment with a grinding wheel through indexing movement in the axial direction thereof. The grinding cycle is performed with said camshaft being rotated and rocked respectively about its axis and a pivot axis parallel thereto and includes first to fourth steps. The substantial part of a stock removal of each cam is removed in the first step wherein the grinding wheel is infed at a rapid infeed rate as the camshaft is rotated at a slow rotational speed. The camshaft is rotated at a high rotational speed in the second step for removing from the cam a part of the stock removal which is to be cut off, but left uncut in the first step. Rotation of the camshaft at the high rotational speed is continued while the grinding wheel is infed in the third step for removing a grinding crack layer from the cam. Finally, the fourth step is carried out, wherein for finish grinding, the grinding wheel is infed against the cam rotating at a slow rotational speed.

Method of grinding cams on a camshaft

A dressing device for a grinding wheel comprises a wheel head for supporting the grinding wheel in a manner adapted for grinding the outer surface of a workpiece; a dressing tool provided to cut into the grinding wheel for dressing the same; a feed motor to feed the dressing tool so as to cut into the grinding wheel; a device for detecting the diameter of the grinding wheel; and a control device which controls the feed motor in response to the output of the detecting device so that the depth of the cut caused by the dressing tool is controlled in accordance with the diameter of the grinding wheel.

Dressing device for grinding wheels

A method of grinding a workpiece for shaping it into a cam by imparting a rotary motion and a rocking motion, which conforms to the profile of a master cam, to the workpiece. In the first rough grinding step, a grinding wheel is rapidly entered into the workpiece while the workpiece is rotated at a low velocity. In the second rough grinding step, the grinding wheel is rapidly entered into the workpiece while the workpiece is rotated at a velocity greater than the low velocity. In the third rough grinding step, the wheel is rapidly entered into the workpiece while the workpiece is rotated at a high velocity. Each of the three steps includes a step for removing the portion left uncut in such a state that the infeed of the wheel is ceased. The depths of cut in the three steps DS.sub.1, DS.sub.2 and DS.sub.3, respectively, are so set that the following relation holds:

Method of forming cam by grinding

Cam grinding machine

A grinding machine wherein a novel arrangement is provided to effect truing and dressing on a surface of a grinding wheel made of hard material such as cubic boron nitride. The arrangement comprises a truing wheel coaxially fixed on one end of a work head spindle of the grinding machine for truing the grinding wheel surface and a dressing roll coaxially fixed on one end of the work head spindle in juxtaposed relation with the truing wheel for backing up free abrasive grains supplied between the grinding wheel and the dressing roll during dressing.

Grinding machine with a CBN grinding wheel

A guard device with a dressing apparatus for a grinding wheel. A front cover member is pivotably supported on a guard body by a hinge shaft. A pair of leg portions are extended from the lower end of the front cover member and carry a pair of dressing tools for dressing the side surfaces of the grinding wheel. A front cover member is swung by the operation of a thread mechanism.

Growing community of inventors

Kariya, Japan

Toshio Maruyama