Patent Application
20190143417
The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2017-217159 filed on Nov. 10, 2017 including the specification, claims, drawings, and abstract is incorporated herein by reference in its entirety.
The present disclosure relates to a machine tool.
A machine tool for performing removal machining on a workpiece with a tool is conventionally known. In this type of machine tool, although demands for automation and high performance are increasing more and more, as a factor hindering the automation, there is a problem that swarf is entangled with a tool of the machine tool.
JP 2010-52102 A discloses an NC processing machine in which there is no possibility of interference between a swarf cutter and the like with a tool, a workpiece, or the like at the time of processing, and further facility expense can be suppressed lower. The NC processing machine includes a tool post freely movable in both the Z-axis direction and the X-axis direction, a turret rotatably supported on the tool post so as to be rotatable around a T-axis, a plurality of tool holders attached to an outer circumferential surface of the turret, and a swarf processing member disposed in such a way as to advance and retract with respect to a processing position in a movement path along which the tool moves at least in either one of the Z-axis direction and the X-axis direction of the tool post.
The entanglement of swarf with a machine tool often occurs when the swarf is continuously generated in lathe turning or the like. Therefore, it is necessary to cut the continuous swarf into fragments.
In general, a machine tool is provided with a rotary part, and bringing a rotating tool into contact with the swarf is relatively easy. However, since the position of the swarf is not fixed, even when the rotating tool comes into contact with the swarf, the swarf often move away from the rotating tool. In view of this, a pinching and cutting function such as a nipper or the like is desired.
Therefore, it is conceivable to use a robot or the like to cut the swarf with a nipper-like cutter. However, in many cases, metal swarf generated during the lathe turning is relatively hard, and accordingly a large force is required for a cutting tool. For this reason, an actuator, a drive mechanism, or the like tends to increase in size, and as a result, costs increase. Further, the size of the robot itself for driving a cutter such as a nipper tends to increase, and inconveniences such as interference with another member or the like may arise.
The present disclosure provides a technique capable of cutting swarf entangled with a tool without adding an actuator or a drive mechanism larger in size.
The present disclosure is a machine tool including a rotating device for rotating a workpiece, a chuck provided at the rotating device and including an opening/closing drive mechanism for gripping and releasing the workpiece, a moving mechanism for adjusting a relative positional relationship between the workpiece and a turning tool for lathing the workpiece, and an attaching device for causing the opening/closing drive mechanism and a swarf cutting tool to engage with each other by attaching the swarf cutting tool to the chuck in a state where the workpiece is not gripped, and for cutting the swarf entangled with the turning tool by driving the swarf cutting tool with an opening/closing operation of the opening/closing drive mechanism.
According to one embodiment of the present disclosure, the attaching device is a robot or a loader.
According to another embodiment of the present disclosure, the robot is provided in the machine tool.
Further, according to another embodiment of the present disclosure, the chuck is constituted by a first sub chuck provided at the rotating device, and a second sub chuck provided so as to be attachable to and detachable from the first sub chuck. The second sub chuck is equipped with the swarf cutting tool, and the attaching device causes the swarf cutting tool to engage with the opening/closing drive mechanism by attaching the second sub chuck to the first sub chuck.
Further, according to another embodiment of the present disclosure, the chuck includes a plurality of claws opened or closed according to the opening/closing operation of the opening/closing drive mechanism, and the attaching device causes the swarf cutting tool to engage with the opening/closing drive mechanism by attaching the cutting tool to the claw.
Further, according to another embodiment of the present disclosure, the chuck includes a plurality of detachable claws opened or closed according to the opening/closing operation of the opening/closing drive mechanism, and the attaching device causes the swarf cutting tool to engage with the opening/closing drive mechanism by detaching the claw from the chuck and attaching the cutting tool.
Further, according to another embodiment of the present disclosure, the chuck includes a plurality of claws opened or closed according to the opening/closing operation of the opening/closing drive mechanism, and the attaching device causes the swarf cutting tool to engage with the opening/closing drive mechanism by causing a part of the cutting tool to engage with the claw while gripping the cutting tool.
Further, according to another embodiment of the present disclosure, the cutting tool is constituted by a first cutting tool and a second cutting tool that are paired, and is configured to cut the swarf by performing an opening/closing operation in the same direction as the direction of the opening/closing operation of the opening/closing drive mechanism.
Further, according to another embodiment of the present disclosure, the cutting tool is constituted by a first cutting tool and a second cutting tool that are paired, and is configured to cut the swarf by performing an opening/closing operation in a direction different from the direction of the opening/closing operation of the opening/closing drive mechanism.
Further, according to another embodiment of the present disclosure, the cutting tool cuts the swarf on a rotational axis of the rotating device.
Further, according to another embodiment of the present disclosure, the cutting tool cuts the swarf at a position offset by a predetermined distance from the rotational axis of the rotating device.
Further, according to another embodiment of the present disclosure, a sensor for detecting the swarf entangled with the turning tool is provided, and the attaching device attaches the cutting tool according to a detection signal of the sensor.
According to the present disclosure, it is possible to cut the swarf entangled with a tool without adding an actuator or a drive mechanism larger in size. As a result, machine stop due to the entanglement of the swarf can be suppressed and the level of automation of the machine tool can be improved.
Embodiment(s) of the present disclosure will be described by reference to the following figures, wherein:
Hereinafter, embodiments of the present disclosure will be described with reference to attached drawings.
The machine tool 10 is a machine configured to cut a workpiece with a tool. More specifically, the machine tool 10 has a lathing function of cutting a workpiece 3 with an applied turning tool while rotating the workpiece 3, and a rotary cutting function of cutting the workpiece 3 with a rotating tool.
The periphery of the machine tool 10 is covered with a cover (not illustrated). The space comparted by the cover is a machining chamber in which the workpiece 3 is machined. By providing the cover, scattering of swarf and the like to the outside can be prevented. The cover is provided with at least one aperture (not illustrated) and a door (not illustrated) for opening and closing the aperture. An operator accesses the inside of the machine tool 10, the workpiece 3, and the like via the aperture opening. During the machining, the door provided at the aperture is closed. This is to ensure safety, environmental friendliness, and the like.
The machine tool 10 includes the spindle device 14 for rotatably holding the workpiece 3 and the tool post 4 for holding a tool 100. The spindle device 14 includes a head stock placed on a base 22 and a workpiece spindle attached to the head stock. The workpiece spindle includes a chuck for grippably and releasably holding the workpiece 3, and can appropriately replace the gripped workpiece 3. In the drawings, a configuration capable of gripping and releasing the workpiece 3 by opening and closing three claws provided at the chuck is exemplarily illustrated. However, the number of the claws is arbitrary. Another configuration for gripping and releasing the workpiece 3 by opening and closing two claws provided at mutually opposing positions may be provided. The workpiece spindle rotates around a workpiece rotational axis extending in the horizontal direction (Z-axis direction).
The tool post 4 holds the turning tool; for example, a tool referred to as a bite. The tool post 4 and the bite are configured to be linearly movable in the X-axis and Z-axis directions when driven by a drive mechanism.
A discharge mechanism for collecting and discharging the swarf scattered during the cutting processing is provided at the bottom of the machining chamber. It is conceivable that the discharge mechanism can be constituted in various forms. For example, the discharge mechanism may be constituted by a conveyor or the like capable of conveying to the outside the swarf dropped due to gravity.
The machine tool 10 includes a controller that performs various calculations. The controller in the machine tool 10 is also referred to as a numerical controller (NC), which controls driving of each portion of the machine tool 10 in response to an instruction from an operator. The controller is, for example, constituted by a central processing unit (CPU) performing various calculations, a memory storing various control programs and control parameters, an input/output interface, an input device, and an output device. The input device is, for example, a touch panel or a keyboard. The output device is a liquid crystal display, an organic EL display, or the like. Both the input device and the output device may be constituted by a touch panel. Further, the controller has a communication function and can transmit and receive various data, such as NC program data, to and from other apparatuses. For example, the controller may include a numerical controller for calculating the positions of the tool 100 and the workpiece at any time. The controller may be a single device or may be constituted as a combination of a plurality of calculation devices.
The machine tool 10 further includes an in-machine robot 20. The in-machine robot 20 includes joints, knots, and a hand.
In the present embodiment, a robot disposed at a predetermined position in the machining chamber is referred to as the in-machine robot. The predetermined position does not necessarily means a stationary position and shall include, in the concept thereof, a movable position that can shift to a desired position during the machining of a workpiece or the like, even when it is fixed to at a certain position in the initial state.
The spindle 30 is attached to the spindle device 14, and the chuck 32 is attached to the spindle 30. The chuck 32 is constituted by a first sub chuck 32a and a second sub chuck 32b. The first sub chuck 32a and the second sub chuck 32b are detachably constituted. The second sub chuck 32b includes claws (jaws) 34a and 34b formed on a surface opposite to a surface facing the first sub chuck 32a so as to grip the workpiece 3. The claws 34a and 34b are provided with soft claws and master jaws to which the soft claws are fixed by means of bolts. The master jaws include rack gears that can mesh with a drive mechanism of the first sub chuck 32a in a state where the first sub chuck 32a and the second sub chuck 32b are in contact with each other.
More specifically, for example, the first sub chuck 32a includes a hydraulic cylinder together with a piston and a piston rod that are fitted into the cylinder. Rack gears are engraved at a tip end of the piston rod, so that a pair of pinion gears can mesh with the rack gears. Rack gears are engraved on rear end surfaces of a pair of master jaws formed with the claws 34a and 34b at tip ends thereof. The rack gears of the master jaws are configured to mesh with the pinion gears of the first sub chuck 32a. When the piston advances under hydraulic pressure, the claws 34a and 34b are closed and grip the workpiece 3. When the piston retracts, the claws 34a and 34b are opened and release the workpiece 3.
A hand 21, which is attached at a distal end of the in-machine robot 20, grips the second sub chuck 32b equipped with the claws 34a and 34b and causes the second sub chuck 32b to move to a desired position to bring one surface of the second sub chuck 32b into contact with the first sub chuck 32a, thereby causing the rack gears of the pair of master jaws of the claws 34a and 34b to mesh with the drive mechanism of the first sub chuck 32a. The first sub chuck 32a and the second sub chuck 32b are fixed by means of bolts. Further, when replacing the claws 34a and 34b, the in-machine robot 20 releases the meshing state between the pair of master jaws and the drive mechanism of the first sub chuck 32a, grips the second sub chuck 32b, and detaches it from the first sub chuck 32a.
In the present embodiment, using such a mechanism for replacing the claws (jaws) 34a and 34b by the in-machine robot 20, a swarf cutting tool is attached to the chuck 32 in place of the claws 34a and 34b, and a large force is applied to the cutting tool using the opening/closing drive mechanism of the chuck 32 to enable cutting of hard swarf such as metal swarf.
As illustrated in
The hand 21 of the in-machine robot 20 grips the second sub chuck 32b and moves the second sub chuck 32b so as to come into contact with the first sub chuck 32a, thereby causing the rack gears of the pair of master jaws to mesh with the drive mechanism of the first sub chuck 32a.
The hand 21 of the in-machine robot 20 grips the second sub chuck 32b and moves the second sub chuck 32b so as to come into contact with the first sub chuck 32a, thereby causing the rack gears of the pair of master jaws to mesh with the opening/closing drive mechanism of the first sub chuck 32a. The opening/closing drive mechanism of the first sub chuck 32a causes the pair of cutting tools 38a and 38b to perform an opening/closing operation in arrow directions illustrated in the drawing. The pair of cutting tools 38a and 38b pinches the swarf 38 from both sides thereof and cuts it into fragments of desirable size.
In
In
Similar to
The hand 21 of the in-machine robot 20 grips the second sub chuck 32b and moves the second sub chuck 32b so as to come into contact with the first sub chuck 32a, thereby causing the rack gears of the pair of master jaws to mesh with the drive mechanism of the first sub chuck 32a. When the drive mechanism of the first sub chuck 32a moves the cams 42a and 42b in a closing direction, the cutting tool 44a and the engaging member 46 move in the Z-axis direction against the elastic force of the spring 48 so as to cause the pair of opposed cutting tools 44a and 44b to perform a closing operation to pinch and cut the swarf 38 from both sides thereof. When the cams 42a and 42b are moved in an opening direction, the cutting tool 44a and the engaging member 46 return the original positions by the elastic force of the spring 48 (opening operation).
In
Although the cutting tools 36a and 36b are attached to the chuck 32 in place of the claws 34a and 34b in
Although the cutting tools 36a and 36b are attached to the tip surfaces of the claws 34a and 34b in
In
As mentioned above, according to these embodiments, it is possible to surely cut the swarf entangled with the turning tool into fragments using the opening/closing drive force of the spindle device 14, without newly adding an actuator or a drive mechanism larger in size. As a result, the machine stop due to the entanglement of the swarf can be suppressed and the automation efficiency of the machine tool can be improved.
In each of the above-mentioned embodiments, in a state where the chuck 32 does not grip the workpiece 3, the cutting tools are attached to the chuck 32 by the in-machine robot 20. However, the cutting tools may be attached by a robot located outside and disposed in the vicinity of the machine tool, or may be attached by a conveyance apparatus such as a loader.
Further, in each of the above-mentioned embodiments, a sensor for detecting whether there is any swarf entangled with the turning tool may be provided at a predetermined position in the machining chamber. The cutting tools may be attached to the chuck 32 by the in-machine robot 20 in response to detection of any entanglement of the swarf by the sensor as a trigger. It is desirable to install the sensor in the in-machine robot 20 and detect the entanglement of the swarf by monitoring the turning tool at an arbitrary position and from an arbitrary direction. Further, it is useful to detect the entanglement position and the entanglement state of the swarf with the sensor and adaptively change the type or the installation position of the cutting tools according to the detection result. Since the cutting tools are attached to the chuck 32 and the spindle 30 can rotate the chuck 32, the cutting surface by the cutting tools can be arbitrarily indexed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-217159 | Nov 2017 | JP | national |
