JPH023441B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a three-dimensional position detection device, and particularly to an improvement in a holding mechanism for a stylus having an electrode contact at one end thereof.

As is well known, in machine tools such as milling machines,
There is a growing trend for a processing machine to have a function of measuring three-dimensional dimensions of a workpiece after processing. For this reason, conventionally, position detection devices such as those shown in Figures 1 and 2 have been used to detect the position of the reference plane and end face of the workpiece, and to detect the machining position from the reference plane and end face. .

In FIGS. 1 and 2, reference numeral 11 denotes an electrode contact made of a conductive sphere, which is provided at one end of the filler 12, and its holding mechanism is constructed as follows.

That is, within the housing 1, the filler 12
is fixed to the disc 4, and receiving members 6, 7, and 8 are held and fixed to the disc 4 via the insulating plate 5.

At the bottom of the housing 1, set screws 3 having spherical bodies 2 are arranged at approximately three equal parts. This spherical body is adapted to be in contact with the receiving members 6, 7, and 8, and a pressing force is applied by the spring 10 through the insulating member 9, so that they are pressed into contact with each other.

14 is a lock screw for locking the set screw 3. The position detecting device having the above-mentioned configuration is connected to the machine tool 1 by the shank 13 as shown in FIG.
When the electrode contactor 11 comes into contact with the workpiece 14 placed on the table 15, it is electrically detected by the detection circuit 16, and the position and the like are detected.

However, in the configuration of the conventional device described above, as is clear from FIG. It is designed to ensure the only stable position.

Therefore, there are disadvantages in that there are many variations in the measured pressure depending on the direction when the electrode contactor makes contact, the number of parts increases, and the processing of the receiving member is troublesome, requiring many man-hours and increasing costs.

The present invention has been made to solve the drawbacks of the prior art, and consists of holding an electrode contactor made of a conductive sphere by two holding members that are pressed into contact with each other in a housing via a stylus. It is characterized in that one contact surface of the electrode contactor is configured to form a concentric spherical shape with the electrode contactor.

The invention will now be described with reference to the embodiments shown in the drawings. In FIGS. 4a and 4b, the electrode contactor 21 is attached to one end of a stylus 22 and is attached to a first holding member, e.g. a disc 22, in a housing 26. The other end of the stylus 22 is fixed to. Disk 23
Three spheres 24 are provided on the bottom surface of the camera at positions approximately divided into three equal parts. A second holding member 25 is disposed at the bottom of the housing 26, and the ball 24 and the second holding member are pressed against each other by a spring 28, and the contact surface of the holding member is provided with an electrode contact as shown in the figure. It has a spherical shape concentric with the child 21.

Further, the housing 26 is provided with a lid 27, and a shank 29 is attached to this lid 27, and as described above, the position detection device of the present invention described above is operated through the shank as shown in FIG. Installed on machine tools, etc.

FIG. 5 shows an example of a contact position detection circuit used in the present invention, in which a lead wire 31 from a connector 30,
32 and a lead 36 from a table 35 on which a workpiece 33 is placed is connected to an input of an amplifier 37. The output of the amplifier 37 is connected to an excitation winding 38' of a relay 38, and a power source 39 is connected via the relay 38 to an alarm device 40 such as a lamp or a buzzer, and to a counter 41.

Now, when the table 35 of the machine tool or its main shaft is moved vertically and horizontally in the direction of the arrow and the electrode contactor 21 approaches and comes into contact with the end surface of the workpiece 33, the input of the amplifier 37 becomes a closed circuit. The output activates relay 38. The annunciation device 40 is therefore activated and the point of contact is quickly and accurately detected. Also, since an input is given to the counter 41 at the same time, the input causes the counter 41 to
By resetting to zero and starting counting from that point, the distance traveled by the table or spindle can be determined.

In addition, in the above embodiment, the disk 23 and the sphere 2
4 may be reversed as shown in FIG. 6.

In FIG. 6, the same reference numerals as in FIG. 4 indicate the same members, and the lower surface of the disk 23 has a spherical shape concentric with the electrode contactor 21, and the three spheres 24' are attached to the housing 26 so as to be in contact with this. The hold is fixed.

It should be noted that the contact surfaces between the sphere 24 and the second holding member 25 in FIG. 4, and the contact surfaces between the disk 23 and the sphere 24' in FIG. can.

As is clear from the above explanation, according to the present invention, the structure is simple, and the positional relationship between the spherical body in the housing and the concentric spherical member facing it can be obtained from a stable position without having to be fixed at one point. , the number of parts is small, and even if there is stick slip due to friction between the above-mentioned sphere and the member, it has no relation to the position of the electrode contactor, so accurate position detection is possible.

[Brief explanation of drawings]

Figures 1a and b are schematic diagrams showing an example of a conventional position detection device, Figures 2a and b are views taken along lines A-A and B-B in Figure 1a, and Figure 3 is a schematic diagram showing an example of a conventional position detection device. A block diagram showing an example of a position detection circuit using the device, FIGS. 4a and 4b are schematic diagrams showing an embodiment of the present invention, and FIG. 5 is a block diagram showing a position detection circuit using the embodiment. FIG. 6 is a schematic diagram showing another embodiment of the present invention. 21... Electrode contact, 22... Stylus, 23
... Disk, 24 ... Sphere, 26 ... Housing.

Claims (1)

[Claims] 1. An electrode contact made of a conductive sphere is held by two holding members that are pressed together in a housing via a stylus, so that one contact surface of both holding members forms a concentric spherical shape with the electrode contact. configured, the other of the holding members consists of three members,
A position detection device characterized in that these members are in contact with the concentric spherical surface.