A numerical control device for a machine tool, the machine tool including: a reference shaft that moves a tool or a workpiece; and a superimposition shaft that moves a tool or the workpiece. The numerical control device superimposes the movement amount of the reference shaft on the movement amount of the superimposition shaft. The numerical control device including a control computation unit that, in response to a superimposition control command, changes at least one of a first vibration rate, a second vibration rate, and a main shaft rotation speed on a basis of a first vibration command, a second vibration command and a main shaft rotation speed command such that the first vibration rate stays constant and the second vibration rate stays constant. The first vibration rate is a number of times that of the reference shaft vibrates per rotation of a main shaft.

Methods of machining a body to produce a chip wherein the body is formed of a material and in a state such that the material exhibits sinuous flow during a machining operation. The methods include providing a layer located on a surface of the body, and machining the body by causing engagement between a cutting tool and the body in a contact region below an area of the surface having the coating layer thereon and moving the cutting tool relative to the body to produce the chip having the layer thereon. The layer reduces sinuous flow in the material of the body.

Methods of machining a body to produce a chip wherein the body is formed of a material and in a state such that the material exhibits sinuous flow during a machining operation. The methods include providing a layer located on a surface of the body, and machining the body by causing engagement between a cutting tool and the body in a contact region below an area of the surface having the coating layer thereon and moving the cutting tool relative to the body to produce the chip having the layer thereon. The layer reduces sinuous flow in the material of the body.

To provide a control device for a machine tool capable of performing thread cutting while reducing the load on the machine tool from the oscillating operation, without extending the cycle time, and capable of reliably shredding chips in a case of performing the non-oscillating operation in the present pass after the oscillating operation in the previous pass. A control device for a machine tool includes: an oscillating operation execution determination unit that determines whether to execute an oscillating operation that causes the cutting tool to oscillate in the radial direction of the workpiece; an oscillation command generation unit that generates an oscillation command of the oscillating operation based on a determination result; a control unit that superimposes the oscillation command on a position command of the feed axis to generate a drive command. The oscillating operation execution determination unit determines to intermittently execute the oscillating operation, and the oscillation command generation unit generates an oscillation command so that a non-oscillating cutting portion of a present pass includes a portion at which oscillating cutting was performed in a previous pass, or so that an oscillating cutting portion of the present pass includes a portion at which non-oscillating cutting was performed in the previous pass.

Methods of inducing segmented flow in a material in which a ductile flow mode would otherwise occur during machining. A monolayer molecular film is formed on a surface of a body of a material in a state such that the material exhibits ductile flow when subjected to shear. The monolayer molecular film has molecules each having a head group adsorbed to the surface, a terminal group, and a hydrocarbon chain therebetween having a chain length of greater than 6. A surface portion of the body is removed by engaging the body with a tool in a contact region below the surface of the body and moving the tool relative to the body to remove the surface portion and the monolayer molecular film thereon. The monolayer molecular film induces segmented flow in the material during the removing of the surface portion.

A display device acquires and displays information on a machine tool that includes a spindle for relatively rotating workpiece and a cutting tool and feed axes for relatively feeding the workpiece and the cutting tool and that performs machining on the workpiece while making the cutting tool and the workpiece swing relatively, and includes: a first information display unit that displays first information indicating a position to which the cutting tool is relatively fed with respect to the workpiece; a second information display unit that displays second information indicating a relationship between the phase of the spindle and the positions of the feed axes; and a range selection unit that selects part of the first information as a selection range, and the second information display unit changes the display range of the second information such that the display range corresponds to the selection range selected by the range selection unit.

With a method for cutting a groove-shaped recess in a workpiece, a cutting tool for a machine tool is provided on a workpiece. The cutting tool is displaced into a cutting position, in which the cutting tool is in engagement with the workpiece. The cutting tool in engagement with the workpiece is displaced relative to the workpiece for cutting the groove-shaped recess. Upon cutting, a chip is produced with a predetermined maximum chip length that is less than a total length of the recess to be produced.

With a method for cutting a groove-shaped recess in a workpiece, a cutting tool for a machine tool is provided on a workpiece. The cutting tool is displaced into a cutting position, in which the cutting tool is in engagement with the workpiece. The cutting tool in engagement with the workpiece is displaced relative to the workpiece for cutting the groove-shaped recess. Upon cutting, a chip is produced with a predetermined maximum chip length that is less than a total length of the recess to be produced.

A controller controls a machine tool, which performs thread cutting for a workpiece, according to a machining program. The controller analyzes operating conditions of a cutting-up/cutting-in motion commanded in the machining program and inserts a cutting-up/cutting-in motion created based on the analyzed operating conditions into the thread cutting. In the insertion of the cutting-up/cutting-in motion into the thread cutting, a cycle including a cutting-in operation, a cutting-up operation for separating chips by raising the cutting tool for cutting in the radial direction of the workpiece, and an operation to cause the cutting tool to approach a start position of an immediately preceding cutting-up operation so as not to interfere with the workpiece is repeatedly performed.

A controller controls a machine tool, which performs thread cutting for a workpiece, according to a machining program. The controller analyzes operating conditions of a cutting-up/cutting-in motion commanded in the machining program and inserts a cutting-up/cutting-in motion created based on the analyzed operating conditions into the thread cutting. In the insertion of the cutting-up/cutting-in motion into the thread cutting, a cycle including a cutting-in operation, a cutting-up operation for separating chips by raising the cutting tool for cutting in the radial direction of the workpiece, and an operation to cause the cutting tool to approach a start position of an immediately preceding cutting-up operation so as not to interfere with the workpiece is repeatedly performed.