Toyoda Koki Kabushiki Kaisha

Yukio Oda

Toshio Tsujiuchi

Norio Ohta

Kunihiko Unno

Hisashi Nakamura

Toshiaki Naya

Tomoyasu Imai

Ikuo Suzuki

Yoshio Wakazono

Toshio Maruyama

Ryohei Mukai

Takayuki Yoshimi

Yasuo Suzuki

Makoto Kikuchi

Tomoyuki Kasuga

Yoshinori Shinmura

Syoji Yamaguchi

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 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

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.

Numerical control grinding machine

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

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 and a first fine grinding on a rotating cylindrical workpiece by the grinding wheel and to halt the first fine grinding in response to a sizing signal from a sizing device which measures the diameter of the workpiece being ground. At the halt of the first fine grinding, the numerical controller advances rest jaws to press the workpiece upon the grinding wheel until another sizing signal is issued from the sizing device. Until the number of the workpieces ground after each truing operation reaches a predetermined number, the numerical controller increase the infeed rate of the grinding wheel in each of the rough and first fine grindings toward a desired infeed rate on a step-by-step basis. Further, the numerical controller diminishes a set size which determines the time point to issue the first-mentioned sizing signal from the sizing device, toward a desired set size on a step-by-step basis with the increases in number of the workpiece ground after each truing.

Grinding machine with a steady rest

A method for grinding a work having a cylindrical portion and a couple of shoulder portions extending at right angles from the opposite ends of the cylindrical portion, the method comprising the steps of:

Method of grinding a workpiece having a cylindrical portion and shoulder

A truing apparatus includes a truing tool supported on a tool support movable radially and axially of a grinding wheel having a rounded corner and drivable by a feed drive unit coupled to the tool support to move along a predetermined path for truing the rounded corner of the grinding wheel. At least one contact member for contacting outer peripheral and end surfaces of the grinding wheel is mounted on the tool support, and a sensor is also mounted on the tool support for detecting a contact between the contact member and the grinding wheel. A feed control system controls the feed drive unit for moving the truing tool along the predetermined path. The feed control system controls the feed drive unit so that the contact member will move radially and axially of the grinding wheel until the sensor is actuated immediately after one truing process and immediately before a next truing process. A grinding wheel position detector detects radial and axial positions of the grinding wheel when the sensor is actuated immediately after the one truing process and immediately before the next truing process. A correcting unit corrects the predetermined path along which the truing tool is to move in the next truing process based on the positions of the grinding wheel detected by the grinding wheel position detector immediately after the one truing process and immediately before the next truing process.

Truing apparatus for a grinding wheel with rounded corners

An apparatus for truing a grinding wheel includes a stylus movable in response to movement of a truer in synchronism therewith, and a template disposed in confronting relation to the stylus with a gap left therebetween. The truer is controlled in its motion by servomotors driven in response to a command issued from a numerical control unit. When the truer is caused by the numerical control unit to move out of control for some reasons, the stylus is brought into engagement with the template, thereby protecting the truer and a grinding wheel being trued thereby against damage which would otherwise result from such uncontrolled movement of the truer. When the truer is to be advanced for truing infeed against the grinding wheel, the stylus is disconnected by a clutch device from the truer, and only the truer is moved in the forward direction while maintaining a proper gap between the stylus and the template.

A feed amount setting device for a machine tool is provided wherein a cradle member, urged for contact engagement with a plate cam, is pivoted within a plane including the rotational axis of the plate cam when the same is rotated by a tool slide feed device. The pivotal movement of the cradle member is converted into the axial movement of a slide sleeve and an actuation sleeve, which is threadedly inserted into the slide sleeve for adjustment of the relative position thereto, in a direction parallel to the rotational axis of the plate cam. The actuation sleeve is formed at its one end with a radially extended flange contacting a lever arm and, when axially moved, pivotally moves the lever arm to thereby actuate a switch element. This element, when actuated, controls the operation of the tool slide feed device.

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Kariya, Japan

Yukio Oda