Toyoda Koki Kabushiki Kaisha

Other

Toyota Jidosha Kabushiki Kaisha

Hiroaki Asano

Keiichi Nakamura

Masaji Yamamoto

Takao Yoneda

Kyosuke Haga

Toshio Tsujiuchi

Toshifumi Sakai

Toshio Maruyama

Shigeo Tanooka

Akira Ito

Yutaka Mori

Tomoyasu Imai

Norio Ohta

Masashi Yanagisawa

Ikuo Suzuki

Masato Kitajima

Minoru Enomoto

Yoichi Yamakawa

Yasuhiro Kobayashi

Tamaki Tomita

Takayuki Hotta

Shigeo Hotta

Isao Ito

Nobunao Morishita

Tetsuya Nakano

Hayashi Kodama

Hirotaka Sugiura

Kenji Yamakage

Nobuhiro Ishihara

An abrasive tool includes an electroformed layer having superabrasive grains electroplated on an outer surface of the electroformed layer, and a plurality of dimples arranged on the outer surface of the electroformed layer using a mold with projections made of gel adhesive. The concentration of the abrasive gains is regulated by changing the number of the dimples (i.e., changing a dimple-area-rate). The gel adhesive preferably has a viscosity of 500,000 cP or smaller. The dimple-area-rate is preferably from 7 to 70%.

Abrasive tool and the method of producing the same

In a grinding method wherein a rotating workpiece and a rotating grinding wheel are relatively moved toward and away from each other and wherein at least three of rough, fine and finish grinding step are performed successively at high, medium and low infeed rates respectively for grinding the workpiece, the grinding wheel is retracted to a back-off position at the end of the rough grinding step. To calculate the back-off position, a first residual grinding amount which is left unground due to the bending of the workpiece is calculated based upon the diameter of the workpiece and the position of the grinding wheel which are detected respectively by an in-process measuring device and an absolute encoder at the end of the rough grinding step, and a second residual grinding amount of the workpiece at the end of the fine grinding step is estimated based upon the first residual grinding amount and a third residual grinding amount which has been calculated at the end of the finish grinding step for a preceding workpiece portion. The back-off position is calculated from the difference between the first and second residual grinding amounts.

Method and apparatus for grinding a workpiece

An apparatus for detecting contact between a contact detection member and a rotating body such as a grinding wheel rotably carried on a wheel head which is movable toward the contact detection member in a grinding machine for example. The apparatus comprises an AE sensor, a rectangular pulse generator, a sampling circuit and a processing device such as a microcomputer. The AE sensor generates an electric signal in response to vibration of the contact detection member. The rectangular pulse generator outputs a rectangular pulse whose duration corresponds to that of vibration. The sampling circuit delivers to the processing device an output indicating the duration of the rectangular pulse. The processing device processes the output delivered thereto so as to decide the occurrence of an actual contact between the rotating body and the contact detection member.

Apparatus for detecting contact with rotating body

A driving power transmission system for transmitting a driving power to front tires and rear tires, wherein a torque transmission device is disposed within a drive line for controlling transmissive torque transmitted to the tires. The torque transmission device is provided with a rotational housing to which a driving power from an engine is applied, a cylindrical shaft which is drivingly connected to the tires. The housing receives a clutch mechanism for transmitting a rotational torque from the housing to the cylindrical shaft, a piston located adjacent to the clutch mechanism and a pressure generating mechanism having an input rotational shaft for generating a pressure so as to actuate the clutch mechanism through the piston. The torque transmission device further provided with a differential speed amplifying mechanism connected to the housing and the cylindrical shaft for amplyifying a rotational speed difference therebetween in order to rotate the input rotational shaft of the pressure generating mechanism at an amplified speed. When the rotational speed difference occurs between the housing and the cylindrical shaft, the speed difference is amplified by the amplifying mechanism and then applied to the pressure generating mechanism. As a result, a large pressure is quickly generated and is applied to the clutch mechanism via the piston in order to actuate the clutch mechanism.

Driving power transmission system for vehicle

A pressure generation and responsive mechanism is provided wherein several blade members bodily movable with a first member is received within a space formed in a second member. The second member provides a first flat end surface in friction engagement with the blade members, and an actuation piston, by itself or in cooperation with the second member, provides a second flat end surface in friction engagement with the other ends of the blade members. Silicon oil is filled within several space sections defined by the first and second flat end surfaces and the blade members. When the first member is moved relative to the second member, the blade members compulsorily displaces the silicon oil within the several space sections against friction resistance with the first and second flat end surfaces. Thus, a pressure is generated within each of the several space sections to actuate the actuation piston.

Pressure generation and responsive mechanism with high viscous fluid

A driving power transmission device having a clutch provided between a first shaft and a second shaft relatively rotatable to each other for transmitting a driving power is provided, wherein a housing to which the first shaft is connected and a piston provided in the housing for actuating the clutch define a cylindrical space in order to receive a plurality of blades rotatable with the second shaft. High viscous fluid is filled within the cylindrical space defined by the housing and the piston. Each of the blades has a convexly curved side surface and a concavely curved side surface located at opposite sides in rotational direction. When the first shaft rotates faster than the second shaft, the convexly curved side surfaces of the blades compulsorily displaces the high viscous fluid within the space in order to generate a pressure actuating the clutch through the piston. In this forward torque transmission, the tranmissive torque becomes relatively large. When the first shaft rotates slower than the second shaft, the concavely curved side surfaces of the blades compulsorily displace the high viscous fluid in order to generate a pressure for actuating the clutch. In this reverse torque transmission, the transmissive torque becomes smaller than that in the forward torque transmission.

Driving power transmission device

A differential drive mechanism for automotive vehicles includes a rotary housing rotatably mounted within a support casing and being in drive connection with an input shaft, a pair of split drive axles rotatably carried by the rotary housing coaxially with the rotational axis thereof for relative rotation, a pair of axially spaced pistons slidably disposed within a sealed cylindrical chamber in the rotary housing to be axially inwardly moved by a thrust force applied thereto, a pair of axially spaced clutch assemblies disposed between the pistons for transmitting drive torque from the input shaft to the drive axles when engaged by axially inward movement of the pistons, and an annular intermediate element disposed between the clutch assemblies for applying the thrust force acting on one of the clutch assemblies to the other clutch assembly, wherein the thrust force is produced in response to differential rotation between the rotary housing and the drive axles and applied to the pistons.

Differential drive mechanism

An electric power steering apparatus is provided with a torque sensor for detecting manual torque input to a steering shaft of an automobile and an electric motor for generating auxiliary steering power so that a load current is applied to the electric motor in accordance with the level of manual torque detected by the torque sensor. The electric motor and a steering system are coupled together through a speed reducing mechanism for reducing the speed of rotation of the electric motor and also through a clutch mechanism. The electric power steering system is further provided with an actuating mechanism for controlling the clutch mechanism such that it is engaged only when the electric motor is rotating. Therefore, the speed reducing mechanism and the electric motor have no adverse effects on the return of the steering wheel.

Electric power steering apparatus

A torque transmission device is provided wherein a rotary housing is connected to one of front and rear drive shafts which respectively drive front and rear axles of a four-wheel drive vehicle, while a rotary shaft coaxially carried by the rotary housing is connected to the other of the front and rear drive shafts. The housing receives therein a multiple disc clutch device for transmitting rotational power between the housing and the shaft through friction engagement between alternately arranged outer and inner clutch discs which are respectively rotatable bodily with the housing and the shaft. The housing also receives an axially movable piston to press the clutch discs for friction engagement. An end wall of the housing or an end cap secured thereto and a facing end surface of the piston define an axially narrow circuit chamber, within which a rotary with several radially extending blade portions is received to be rotated by the shaft. Several space sections into which the chamber is divided by the rotor blade portions are filled with silicon oil of a high viscosity. When the rotational speed difference occurs between the rotor and the housing, a pressure is generated within each of the space sections thanks to the high viscosity of the silicon oil and is directly applied to the piston, whereby rotational power is transmitted from the housing to the rotary shaft and vice versa.

Torque transmission device for a four-wheel drive vehicle

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 vehicular four-wheel drive system which includes: an oil pump adapted to be actuated by the relative rotations of a first rotating shaft connected to front wheels and a second rotating shaft connected to rear wheels for discharging pressure oil; a hydraulic clutch having a cylinder chamber communicating with the discharge passage of the oil pump; an electromagnetic throttle valve for controlling the discharge pressure of the oil pump; and a control mechanism for changing the throttle opening of the electromagnetic valve in accordance with the running situation of the vehicle.

Four-wheel drive system

A driving free distribution transmission for use with a vehicle with fourwheel drive. The vehicle has first and second drive shafts which are connected with the front and rear wheels, respectively. The transmission has a hydraulic clutch, a differential pump, a bias spring, and a selector valve. The clutch has outer and inner plates which are caused to frictionally engage with each other to transmit rotary power between the two drive shafts. The pump produces a hydraulic pressure corresponding to the difference between the rotating speeds of the drive shafts. The oil delivered by the pump is forced into a reservoir through a first passage in which a restrictor is formed. A second passage connects the pump with an oil chamber in the clutch. A third passage connects the oil chamber with the reservoir without via the restrictor. The spring always presses the outer and inner plates towards each other. When the difference between the speeds of the drive shafts is small, the selector valve closes the second passage and opens the third passage. When the difference is large, the valve opens the second passage and closes the third passage.

A driving force distribution transmission for vehicles with four-wheel

An apparatus for electronically controlling the steering force needed to operate the handle of a vehicle, according to the velocity of the vehicle and the angular displacement of the handle. The apparatus includes a memory for storing various characteristic maps of different steering characteristics, a selecting switch for selecting one of these maps, and a control circuit for applying the electric current depending on the selected map to the solenoid of a flow control means which controls the pressure flow supplied to the power cylinder of a power steering system. The driver of the vehicle can select any desired control pattern from the memory by operating the selecting switch.

Steering force controlling apparatus for power steering system

In a cam grinding machine, a first diaphragm chuck is provided on a spindle rotatably supported on a rocking table for clamping one journal portion of a cam shaft and a second diaphragm chuck is provided on a support spindle rotatably and slidably supported by a tailstock in coaxial alignment with the spindle for clamping another journal portion of the cam shaft. Accordingly, cam portions of the cam shaft are ground with journal portions of the cam shaft being used as a reference.

Cam grinding machine

A grinding machine comprising a truing apparatus for truing a grinding wheel made of cubic boron nitride. A traverse carriage of the truing apparatus is mounted for movement in a direction parallel to the axis of the grinding wheel. A truing head carrying a truing wheel is mounted on the traverse carriage for movement toward and away from the grinding surface of the grinding wheel. A detection member is mounted on the truing head to be movable toward the grinding wheel. The truing head is first fed toward the grinding wheel until the contact between the detection member and the grinding wheel is detected. The truing head is then fed toward the grinding wheel by a truing amount in response to the detection of the contact between the detection member and the grinding wheel.

Growing community of inventors

Okazaki, Japan

Hiroaki Asano