JPH0217761Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an air sensor for detecting a workpiece used in a power chuck for a lathe.

[Conventional technology]

Conventional chucks for lathes, especially power chucks, have swinging pawls on the chuck body, which are swung by an actuator such as a hydraulic cylinder or diaphragm, or chucks that have multiple diagonal holes in the main body. , there is one in which chuck pins are attached so that they can move forward and backward, and each chuck pin is moved forward and backward to open and close using an actuator such as a hydraulic cylinder.

[Problem that the invention attempts to solve]

When a conventional power chuck as described above is used to automatically chuck a workpiece using a robot manipulator, it is necessary to detect whether the workpiece is placed in the correct position relative to the chuck.

In this case, if the workpiece is of a certain size, it is possible to install a workpiece sensor at a certain position on the chuck, and if the workpiece is detected by this sensor, it will be determined that it is in the correct position. When the size of the workpiece changes frequently due to mass production, it is very troublesome to change the position of the sensor each time, and there is a problem that production stops during this time.

[Means for solving problems]

In order to solve the above problems, this invention was developed in a lathe chuck in which the rear surface of the workpiece is brought into close contact with the workpiece receiving surface of the workpiece stopper provided on the front surface of the lathe chuck. A plurality of air sensor holes are arranged side by side, and a switching valve is provided at an appropriate position in the chuck body to switch between the air sensor circuit provided in the chuck body and each of the sensor holes so that only one air sensor hole communicates with the air sensor circuit.

[Effect]

Since this invention has the above-mentioned configuration, when the size of the workpiece to be mounted on the chuck changes, the changeover valve is switched accordingly to allow only the sensor hole suitable for the size of the workpiece to communicate with the air sensor circuit.

When only the predetermined sensor hole is communicated with the sensor circuit in this way, compressed air sent from the compressed air source is blown out from the sensor hole.

When the front of the sensor hole is open, compressed air will freely blow out, but if the workpiece moved by the manipulator is correctly applied to the receiving surface of the workpiece stopper on the front of the chuck, the sensor hole will be blocked by the workpiece. Therefore, the air blowout stops.

As a result, the air pressure within the sensor circuit increases rapidly. Therefore, if a pressure switch or the like is used to detect the increase in pressure within the sensor circuit, it is possible to determine whether or not the workpiece is correctly applied to the chuck.

〔Example〕

In the figure, reference numeral 1 denotes a chuck body fixed by bolts to a supporting portion of the front main shaft of the lathe, and this body is made up of three members joined together by bolts 3.

Reference numeral 4 denotes a plurality (generally three) of diagonal holes formed near the inner periphery of the main body 1 in a shape that tapers forward, into which a chuck pin 5 is inserted so as to be freely movable forward and backward.

A groove 6 in the axial direction is formed in this chuck pin 5, and a protrusion on the inner end of a bolt 7 screwed into the main body 1 is engaged with this groove 6 with an appropriate play. Do not rotate beyond a small range.

Further, the outside of the front end of the chuck pin 5 is recessed to fix a chuck pawl 9 therein, and a T-shaped engaging portion 10 is provided at the rear end of the chuck pin 5.

Reference numeral 12 denotes an actuator provided in a space within the main body 1, and the shaft portion 13 on the rear side is connected to a forward/backward rod that passes through the rear of the main body 1 and a main shaft (not shown), and this forward/backward rod is operated by a power cylinder. It moves forward and backward, and the locking pin 1 fixed to the main body 1
1 prevents rotation.

The outer periphery of the actuator 12 is provided with the same number of notches 15 as the chuck pins 5, and the engaging portion 10 at the rear end of the chuck pin 5 is engaged with the notches.

Reference numeral 16 denotes a work stopper fixed at a position facing each chuck pawl 9 on the protrusion 14 formed on the front surface of the main body 1, and has two inner and outer parts on the receiving surface 17 of the entire surface thereof.
Air sensor holes 18 and 19 are formed side by side in the radial direction.

A radial valve mounting hole 21 located at the rear of each work stopper 16 is provided in the protrusion 14, and a rotatable switching valve 22 is mounted in each hole 21.

The switching valve 22 is provided with a communication hole 23 at its center that does not reach from the inner end to the outer end.
A valve hole 2 opened on the outer periphery of the switching valve 22 is located in the middle of the switch valve 22.
The valve holes 25 and 26 are arranged at different positions in the axial direction as shown in FIG. 1, and with a phase of 90 degrees as shown in FIG. 2.

In addition, the front part of the protruding part 14 and the work stopper 16
are provided with communication holes 27 and 28 that communicate with the air sensor holes 18 and 19, and the rear ends of these communication holes 27 and 28 are opened into the hole 21, but these openings are connected to the valve holes 25 and 28, respectively.
The valve hole 2 of the switching valve 22 is arranged in a position communicating with the switching valve 26.
5 communicates with the communication hole 27, the valve hole 26
does not communicate with the communication hole 28, and from this state the switching valve 2
2 by 90 degrees, the valve hole 26 communicates with the communication hole 28, and the valve hole 25 comes out of the communication hole 27.

An air passage 3 is provided at the center of the actuator 12.
1, and the front end of this passage 31 is connected to the switching valve 22.
The inner end opening of the communication hole 23 is connected to the inner end opening of the communication hole 23.

The air passage 31 is connected to a compressed air source consisting of a compressor, a receiver tank, etc. through a passage in the main shaft (not shown), and a pressure sensor such as a pressure switch and a solenoid valve are provided along the way to form an air sensor circuit. .

In addition, the above pressure sensor is connected to the control amplifier,
The amplifier is configured to output a predetermined control signal to a control circuit of the lathe.

Next, the operation of the above embodiment will be explained. When the valve hole 25 of the switching valve 22 communicates with the communication hole 27 as shown in the figure, only the outer air sensor hole 18 is in the operating state.

In this state, before the workpiece is gripped, the actuator 12 moves forward, each chuck pin 5 moves forward within each diagonal hole 4, and each chuck pawl 9 at the tip approaches each other.

Further, the compressed air sent through the air passage 31 passes through the communication hole 23 of the switching valve 22 and passes through the communication hole 27.
The air is blown out from the air sensor hole 18 through the air.

Now, the manipulator of the robot (not shown) grabs the ring-shaped workpiece 32 and moves it to the chuck claw 9, and each chuck 9 touches the workpiece 32.
and the workpiece 32 is inside the chuck body 1.
The reference surface 33 that has already been finished so that it is almost concentric with the workpiece receiving surface 17 of the workpiece stopper 16
The state should be in contact with .

When the workpiece 32 is applied to the workpiece receiving surface 17 of the chuck as described above, the reference surface 3 of the workpiece 32
3 closes the sensor hole 18.

When the sensor hole 18 is blocked, the air pressure in the air passage 31 rises rapidly, the pressure sensor senses this, and the signal is input to the control amplifier, which is amplified to operate the control device and move the actuator 12 backward. expand each chuck pawl 9, grab the workpiece 32 from the inside and pull it backwards, and the workpiece 32
is brought into close contact with the work stopper 16 and fixed accurately.

Then, after the manipulator releases the workpiece 32 and returns to its original position, turning is preferably performed by rotating the main shaft.

In addition, when turning small-diameter workpieces, selector valve 2
2 toward the figure 2, turn it 90 degrees to the right and open the valve hole 25.
At the same time as the valve hole 26 is removed from the communication hole 27, the valve hole 26 is made to communicate with the communication hole 28.

In this state, compressed air supplied from the air passage 31 is blown out from the air sensor hole 19.

In this state, the presence or absence of a workpiece having an outer diameter that can cover only the air sensor hole 19 can be detected.

In addition to the above-described embodiment, it is of course possible to use a type of chuck that grips the outside of the workpiece with chuck claws, and the air sensor holes can also be provided not only in two locations but also in three or more locations. Furthermore, the switching valve can be automatically switched by remote control.

〔effect〕

As mentioned above, this device has multiple air sensor holes in the front of the lathe chuck, and a switching valve allows air to be blown out from any sensor hole. The sensor hole that blows out air is selected accordingly to ensure reliable detection of the workpiece. Therefore, when turning workpieces with different diameters, air blowing from the target sensor hole can be started in a very short time, which has the effect of shortening the sensor downtime when changing workpieces.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing an example of a lathe chuck implementing this invention, and FIG. 2 is an enlarged lateral plan view of the switching valve portion. 1... Chuck body, 9... Chuck claw, 12
...actuator, 16...work stopper,
17... Workpiece receiving surface, 18, 19... Air sensor hole, 22... Switching valve, 23, 27, 28... Communication hole, 25, 26... Valve hole, 31... Air passage, 3
2...Work, 33...Reference surface.

Claims (1)

[Scope of utility model registration request] A lathe in which a plurality of chuck pawls that are opened and closed by a power cylinder are provided on the front part of the chuck body that rotates with the main shaft, and the rear surface of the workpiece gripped by the chuck pawls is brought into close contact with the workpiece receiving surface of the workpiece stopper on the chuck body. In the chuck, a plurality of air sensor holes are provided in a radial direction on the work receiving surface of the work stopper, and the air sensor circuit provided in the chuck body and each of the sensor holes are switched so that only one air sensor hole communicates with the air sensor circuit. An air sensor for a lathe chuck, characterized by having a switching valve installed at an appropriate location on the chuck body.