JPH0511443Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a device for detecting the machining reference plane and other positions of a workpiece mounted on a metal processing machine. This invention relates to improvements in a device for detecting the relative position of a workpiece to a tool mounting axis by attaching a detection rod to the workpiece and electrically detecting contact between the detection rod and the workpiece on a processing table. It is something.

As shown in FIG. 1, this type of conventional position detection device forms an electrical closed circuit 5 when a detection rod 2 attached to a tool mounting shaft 1 contacts a workpiece 4 on a processing table 3. I installed it in this circuit so that
The operator can easily recognize the contact between the detection rod 2 and the workpiece 4 using the LED 6 and other display devices. Here, in FIG. 1, 7 is a tool chuck attached to the tool mounting shaft 1, 8 is a holder on which the tool chuck 7 is attached instead of the tool,
The detection rod 2 is fixed to a holder 8 via an insulator 9. 10 is a battery, and an electric circuit 5 including this battery 10 is actually built into a holder 8, one end of which is connected to the detection rod 2, and the other end connected to the holder 8, and the holder 8 is connected to a tool. When the detection rod 2 is attached to the chuck 7 and brought into contact with the workpiece 4, the circuit 5 is closed and the LED 6 lights up.

However, with this conventional device, the state in which the detection rod 2 and the workpiece 4 are close is not displayed, so the operator must carefully observe the gap 11 between the detection rod 2 and the workpiece 4. while moving the tool mounting shaft 1 or table 3 to detect the detection rod 2 and workpiece 4.
Not only does this require close attention to the position detection work, but the tool mounting shaft 1 and table 3 are often moved more than necessary, resulting in errors in measurement values and There was a problem with the 2 being damaged.

This invention was made in order to solve the problems of the conventional device, and by providing a display means to display the state when the detection rod and the workpiece approach, it is possible to locate the workpiece. This not only makes the detection work easier, but also prevents measurement errors and damage to the detection rod due to erroneous operation.

That is, the position detection device of this invention detects the contact between the detection rod 2, which is electrically insulated and mounted on the tool mounting shaft 1 of the processing machine, and the workpiece 4 placed on the processing table 3. In the workpiece position detecting device, which is equipped with an electric circuit for detecting the contact and a contact display means 13 for indicating the contact, the electric circuit includes an oscillation circuit 12, and an alternating output from the oscillation circuit causes the detection rod to be detected. A circuit is formed to detect a change in capacitance that occurs between 2 and workpiece 4 before they come into contact with each other, and a circuit is formed to detect a change in capacitance that occurs between the contact display means 13 and the workpiece 4. This is characterized in that both display means 14 and display means 14 are provided. Here, the circuit for detecting the capacitance 11 between the detection rod 2 and the workpiece 4 includes a circuit for detecting the magnitude of the alternating current flowing through the closed circuit formed via this capacitance, A circuit that detects the oscillation frequency of an oscillation circuit using capacitance as an oscillation element can be used. The detected change in capacitance can be displayed by a change in the brightness of the LED or a digital display using a 7-segment LED.

Next, FIG. 2 showing an embodiment of this invention will be explained. The circuit of the illustrated embodiment uses a Colpitts oscillation circuit 12, and a red LED 13 is used as a means for indicating contact between the detection rod 2 and the workpiece 4.
A green LED 14 is used as a means to display the change in capacitance 11 between the detection rod 2 and the workpiece 4 before contact.
This method uses changes in brightness. Oscillation circuit 12
The oscillation output is transmitted and received between the coils 15 and 16, and when the capacitance in the gap 11 between the detection rod 2 and the workpiece 4, which are connected in series with the coil 16, changes, the coil 16 is The flowing alternating current value changes, which changes the base current of the transistor 17, so the brightness of the green LED 14 connected to the collector of the transistor 17 changes as the detection rod 2 changes.
It changes depending on the size of the gap 11 between the workpiece 4 and the workpiece 4.

That is, when the switch 18 is turned on, the oscillation circuit 12 starts oscillating, and when the detection rod 2 and the workpiece 4 approach to some extent, the green LED 14 starts emitting light. As the detection rod 2 and the workpiece 4 approach, the base current of the transistor 17 increases and the collector current also increases, so the green LED 14
The brightness of the light increases. The detection rod 2 is the workpiece 4
When it comes into contact with , the circuit connecting the red LED 13 is closed and the red LED 13 emits light.
Therefore, by observing the brightness of the green LED 14, the operator can recognize the approaching state of the detection rod 2 and the workpiece 4, and move the tool mounting shaft 1 or the table 3 based on this. Accordingly, the detection rod 2 and the workpiece 4 can be quietly brought into contact and accurate positioning can be easily performed.

As described above, according to the position detection device of this invention,
Since the operator can easily and accurately recognize the approach state between the detection rod 2 and the workpiece 4, positioning work is not only facilitated, but also the operator can avoid excessively moving the tool mounting shaft or processing table. There is no need to worry about moving the workpiece, it is possible to accurately detect the position of the workpiece, and there is no risk of damaging the device due to erroneous operation.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional position detection device, and FIG. 2 is a diagram showing an embodiment of this invention. In the figure, 1 is the tool mounting shaft, 2 is the detection rod, 3 is the processing table, 4 is the workpiece, 7 is the tool chuck, and 8
1 is a holder, 9 is an insulator, 11 is a gap, 12 is an oscillation circuit, 13 is a red LED, and 14 is a green LED.

Claims (1)

[Scope of utility model registration request] An electric circuit for detecting contact between a detection rod mounted in an electrically insulated state on a tool mounting shaft of a processing machine and a workpiece placed on a processing table, and a contact display means for displaying the contact. In the workpiece position detection device equipped with the above, the electric circuit includes an oscillation circuit, and an alternating output from the oscillation circuit causes an electric current to be generated between the detection rod and the workpiece before they come into contact with each other. A metal processing machine characterized in that a circuit for detecting a change in capacitance is formed, and a contact display means and an approach display means for displaying a detected change in capacitance are provided. Workpiece position detection device.