Toshiba Kikai Kabushiki Kaisha

Other

Masahito Shiozaki

Takeshi Momochi

Kazuo Nagashima

Hideo Fujie

Makoto Sagara

Toshihiro Ueta

Michio Matsumoto

Jun Fujita

Tomoo Hayashi

Seiji Nakajima

Tadashi Sasaki

Michio Matumoto

Haruhito Sugiyama

A processing method and a processing machine for restraining abrupt increase in a load applied to a tool in entering a workpiece and for avoiding decrease in tool's life span are provided. When an end mill EM is entered into a processing surface of a workpiece W, the end mill EM is first entered obliquely to a processing surface of the workpiece W, and is moved oppositely to the entering direction while keeping the cutting depth. Alternatively, the end mill EM is entered obliquely to the processing surface of the workpiece W and is moved oppositely to the entering direction while gradually increasing the cutting depth of the end mill EM. When the cutting depth reaches a predetermined cutting depth, the end mill EM is moved parallel to the processing surface of the workpiece W.

Processing method for carving a workpiece

A control apparatus for a drilling machine and a drilling method capable of quick adaptation to drilling by drills of various diameters, especially drills of small diameters, and of improving cutting efficiency. The control apparatus includes a cutting condition setting unit for setting the cutting conditions in accordance with the depth of the hole being drilled and a control unit for controlling the rotary speed and movement position of the drill. The cutting condition setting unit defines the regions of the beginning part, the inner part, and the penetration part from the side close to the drill of the workpiece toward the depth direction of the hole of the workpiece in accordance with the depth of the hole when drilling a throughhole.

Control apparatus for drilling machine and drilling method

A main-shaft malfunction-state detector in an air bearing type machine tool, in which an abnormal contact of a main shaft with a housing is reliably and automatically detected. The contacting state of the main shaft,and the housing,is detected through the presence of electric conductivity by a contact detection device,A contact decision device,determines the contact of the main shaft,with the housing,based on the detected conductivity, thus automatic and certain preventative measures, such as the main shaft of the machine tool stops and so on, are based on the above decision.

Main-shaft malfunction-state detector in an air bearing type machine tool

A main-shaft malfunction-state detector in an air bearing type machine tool, in which an abnormal contact of a main shaft with a housing is reliably and automatically detected. The contacting state of the main shaft 11 and the housing 13 is detected through the presence of electric conductivity by a contact detection means 31. A contact decision means 32 determines the contact of the main shaft 11 with the housing 13 based on the detected conductivity, thus automatic and certain preventative measures, such as the main shaft of the machine tool stops and so on, are based on the above decision.

A profile processing method and a processing machine therefor which can obtain a good finish surface accuracy in all the carving surfaces and curb the decrease in tool's life are provided. More specifically, an end mill is first moved along an outermost side of an annular groove in carving the annular groove to a work. Consequently, the end mill is gradually moved to inside to be moved and carve along the annular groove. When the outermost side of the annular groove is carved, the movement path of the end mill is selected so that the outermost side is down-cut (counterclockwise in FIG. 5). When further inner side is carved, the movement path of the end mill is selected so that the direction of the relative movement path is opposite to the direction of the relative movement path when the outermost side is carved, in other words, the carved surfaces are down-cut by the end mill.

Profile processing method and processing machine therefor

A surface finishing method and a machine therefor, in which good finish accuracy can be obtained in all carving surfaces and deterioration of tool's life can be prevented. When a surface of a concave portion formed on a workpiece is carved, an end mill is first revolved along an outermost side of a slope, and is moved toward inside and revolved along a circumferential direction. When a surface of the slope is carved, a movement path of the end mill is selected so that the surface of the slope is down-cut. When a bottom is carved, the end mill is moved from inside to outside, in other words, the movement path is selected so that a surface of the bottom is down-cut.

Surface finishing method and machine for the same

A positioning control method (80) has a setting section (81) for setting a comparison reference value in accordance with a machine tool in advance, a detecting section (82) for detecting a command value by the rapid traverse command G00, a comparing section (83) for comparing the comparison reference value and the command value, and a determining section (84) for changing the rapid traverse command G00 to a linear interpolation command G01 when the command value is smaller than the comparison reference value, executing the rapid traverse value G00 when the command value is larger than the comparison reference value, and selecting either one of the rapid traverse command G00 or the linear interpolation command G01 when the comparison reference value is equal to the command value. Less effective short-distance rapid traverse command is converted to the linear interpolation command, thus speeding up positioning control to make an entire processing of the workpiece faster.

Positioning control method, numerical control apparatus, numerical

A machine with a worn detection function for a tool capable of reliably carrying out a worn detection for a tool. A present consumption power PW1 of a built-in motor 19, driving a main shaft 11, is watched and compared with a reference consumption power PW2, previously defined, by using a load meter 31, an A/D converter 32, a comparator 33 and a processing unit 34, thereby wear on the tool 12 is detected when the consumption power PW1 is larger than the reference consumption power PW2 as a cutting process is advanced. The main shaft 11 is supported by air static-pressure bearings 14 to 18, so that noise created with rotating, which exert an influence upon the consumption-power detected value, is extremely smaller as compared with the conventional antifriction bearing and so on. Thereby allowing delicate fluctuation of the consumption power to be detected, and naturally the worn detection for the tool 12 to be ensured.

Machine tool with worn-detection function for tool

In a machine tool provided with a column 4 mounted on a back end portion of a bed 1 having a table 2, and a spindle head 20 arranged in a vertically movable manner to the column 4, both sides of an upper portion of the column 4 is connected with both sides of a front-end portion of the bed 1 through support members 42, 43. Even the machine has a structure that the spindle head 20 embeds a main shaft rotating at high rpm, vibration can be reduced. The column is affected by a force to fall down in the direction due to the weight of the spindle head 20, but the tilt caused by the force can be avoided. Accordingly, a high finish surface accuracy can be ensured without an increase in size and weight.

Machine tool

In a numerical control of a machine tool, the relation between the total number of instructions, or the range of movement of the movable member of the machine tool and the actual amount of movement is not represented by a straight line but periodically change sinusoidally over substantially equal ranges of movement, due to a lead error of a ball screw used for moving the movable element. For the purpose of correctly compensate the position error in a short time, the total range of movement of the movable element is divided into a plurality of ranges, and start and end points of movement, types of movement of respective ranges and periods thereof are stored in memory means. The actual position of the movable element and the data stored in the memory means are used to correct the actual position of the movable member.

Method and apparatus for compensating positional errors

A complete-circle operation of a machine tool controlled by an NC-device. Even if the NC-device gives operation commands for respective shafts of the machine tool on the basis of a control locus which is to be a complete circle, the actual operation locus of the machine tool is not a complete circle because the machine tool generates errors due to various causes such as thermal deformation, machine accuracy, etc. If the errors are corrected individually to improve the accuracy, the complexity of the processing cannot be avoided. It is assumed that the operation locus of the machine tool which is controlled for a complete circle becomes an ellipse due to errors involved. A simple process corrects the ellipse such that it is converted to a complete circle.

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Niigata, Japan

Masahito Shiozaki