JPS59141002A - Position detector - Google Patents

Abstract

PURPOSE:To enable precise detection with output from an external switch by a detector wherein an electrode contact is held through a stylus with first and second holding members coming into pressure contact with each other in a housing. CONSTITUTION:An electrode contact 21 is attached to one end of a stylus 22, the other end of which is fixed to a first holding member, such as a disc 23, in a housing 26. A second holding member 25 is arranged at bottom of the housing 26, and a curved surface body of revolution 24 of the first holding member comes into pressure contact with the second holding member 25 by a spring 28, thereby to hold the electrode contact 21. Since the electrode contact is thus held to assume a constant position, it becomes possible to make precise detection with output from an external switch.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to improving the detection accuracy and reliability of a three-dimensional position detection device, particularly a position detection device equipped with a stylus holding mechanism having an electrode contact at one end thereof. Regarding improvements.

BACKGROUND TECHNOLOGY AND PROBLEMS As is well known, there is an increasing tendency for machine tools such as milling machines to be required to have a function for measuring three-dimensional dimensions of a workpiece after processing. For this reason, conventionally, position detection devices such as those shown in FIGS. 1 and 2 have been used to detect the position of the reference surface and end surface of the workpiece, and to detect the processing position from the reference surface and end surface.

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, in the housing 1, the filler 12
1C is fixed, and the members 6, 7.8 of the receiver are held and fixed to the disk 4 via the insulating plate 5.

At the bottom of the housing l, there are spheres 2 divided into approximately three equal parts.
A set screw 3 having a diameter is provided. The spherical body is arranged so that the receivers are in contact with the members 6, 7.8, 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 detection device having the above-mentioned configuration can be accessed by a machine tool machining tool 14 through a shank 13, for example, as shown in FIG. When the electrode contactor 1 comes into contact with the workpiece 14 placed on it, this contact causes the detection circuit 16
It is directly electrically detected by the sensor, and the position, etc., is detected.

However, although the position detection method of the conventional device described above has good detection accuracy, if the workpiece is not conductive or if a non-conductive film is formed on the fitting surface of the C plate due to oxidation etc. Since it becomes undetectable, it has the drawback of causing an accident, especially in the case of automatic processing. In addition, as is clear from Figure 2, the stylus holding mechanism has members 6, 7, and 8 shaped like cones, grooves, and flat surfaces, each of which is in contact with each sphere 2, making it unique in three-dimensional force rotation. It is designed to secure a fixed position.

Therefore, there are many variations in the measured pressure depending on the direction when the electrode contactor makes contact, and the number of parts is large.Moreover, the receiver has the drawback that machining of the members is troublesome, requiring many man-hours and increasing costs.

In addition, in contrast to the above-mentioned external switch method in which the contact between the electrode contactor and the workpiece is directly detected electrically (so to speak) and the switch function outside the housing is used, it is possible to As disclosed in Japanese Patent No. 8502, the contact of the electrode contactor with the workpiece causes a change in the position of the stylus holding mechanism within the nosing, and in response, a switch (internal switch) provided in the mechanism changes. Some use an external switch method in which a switch (switch) is turned on and off to check the contact.

According to this method, the position can be detected even if the electrode contactor is not an integral part, but the internal switch is activated after the electrode contactor contacts the nucleophilic workpiece and a stress curve is applied to the stylus. σ], the stylus ends up being bent. In addition to the fact that this causes errors in position detection, the relief is flF that acts on the electrode contactor when it comes into contact with the workpiece.

When the dynamic stress is 50 g, the position detection error will be about 10 μm.

Moreover, as shown in FIG. 12, the operating stress S and the position detection error E differ depending on the direction (1·rb=1). This is because the stylus holding mechanism has three operating fulcrums.

OBJECT OF THE INVENTION An object of the present invention is to provide a three-dimensional position detection device that has the advantages of the above-mentioned internal switching method and external switching method, has good detection accuracy, and is highly reliable. In order to achieve the above-mentioned purpose, the position detection device is held by first and second holding members that are pressed together in the housing via a stylus, such as an electrode contact made of a conductive sphere, and the first holding member is The member has no concentric spherical surface with the electrode contactor, and the second holding member is in line contact with the concentric spherical surface, a conductive film is formed on one side of both holding parts, and the other force is from an insulator. The present invention is characterized in that a signal responsive to contact between the workpiece and the electrode contactor is detected from the stylus and/or the conductive film.

EXAMPLES The present invention will now be described with reference to examples shown in the drawings.
In FIGS. 4(al, b) and 5, the electrode contactor 21 is attached to one end of the stylus 2, and the stylus n is attached to the first holding member in the nozzling base, such as circle & ZJ. The other end is fixed.The circumferential portion of the disk n is formed to form a rotating curved surface body 24' (S).

A second holding member 5 is disposed at the bottom of the housing portion, and the rotary curved body and the second holding member are pressed against each other by a spring, and the contact surface of the holding member 5 is as shown in the figure. It has a spherical shape concentric with the electrode contactor 21.

Further, the rotating curved surface body 24 has metal films 29a, 29b, 2
9c are provided at approximately three equal positions, and terminals 29a', 29b', and 29c' are provided on each metal film, and lead wires A! 1t A
! 2t i3 is pulled out and connected to the OR circuit OR as shown in FIG.
A lead wire 14 from is connected.

Further, a relay 17fi27 is provided at the upper part of the housing, and a shank 4 is attached to this relay 27, and as described above, the above-mentioned positioning device of the present invention is connected to the shank 4 as shown in FIG. Machine tool 42 as shown
etc. are installed.

Now, in the above-described apparatus of the present invention, the contact surface of the second holding member station for positioning the electrode contactor 21 is temporarily
As shown in the figure (assuming that the first holding member is in contact at three points A, B, and C), it is on a spherical surface of radius H with respect to the center Q of the electrode contactor.

As mentioned above, since the center of the electrode contactor 21 and the center of the contact surface (spherical surface) of the second holding member δ coincide, 3 on the spherical surface
If one point among points A, B, and C is '&P, then PQ=R and A,
Even if the position of B, that is, P changes, the position of Q remains unchanged.

Next, if an error of PQ = R + ΔR1, that is, ΔR occurs, P
If Q is shifted by Δd, Q is shifted to the position of Q', and the error QQ'=e is as follows.

Δd ΔR Therefore, even if there is an error of Δd in the setting position of the holding member of the electrode contactor, the error of the electrode contactor is reduced to ΔR/H. The body U has the axis of the stylus 4 as its central axis, and is pressed into contact with the concentric spherical surface of the second holding member 5 so as to be in line contact with the circular line, and the periphery of the rotating curved surface is statically connected to the housing station. Since they are fitted exactly, Δd4=0 in the resting state, and the front Ii[l! The error ε becomes extremely small. Furthermore, the electrode contactor can operate smoothly even if force is applied in any three-dimensional direction to the electrode contactor.

The rotating curved surface body is made of an insulating material, for example, and is always in full contact with the second holding member 5 due to the instantaneous mechanical displacement when the electrode contactor 21 contacts the object to be measured (conductor or insulator). Any contact on the metal film is turned off, and position detection is performed. In other words, an internal switch function is obtained, but
A lead from the stylus also provides access to an external switch.

FIG. 6 shows an example of a contact position detection circuit used in the present invention, in which lead wires 31 and 32 from a connector blade coupled to a housing station and connected to the output of the OR circuit OR and a workpiece 33 are mounted. The lead edge of the table opening is connected to the input of amplifier 37. The output of the amplifier 37 is connected to the excitation winding 38' of the relay 38, and also connected to the excitation winding 38' of the relay 38.
8, a power source 39 connects to a notification device 4o such as a lamp or a buzzer.
and counter 4].

Now, when the table of the machine tool or its main shaft 41' is moved vertically and horizontally in the direction of the arrow force and the electrode contactor 21Y approaches and contacts the end face of the workpiece 33, the amplifier 370
The input becomes a closed circuit, and the output activates the relay 38. Therefore, the alarm device [140] is activated and the touch point is detected quickly and accurately. At the same time, human power is applied to the counter 4, so by resetting the counter 41Y to zero and starting counting from this point, it is possible to know the distance traveled by the table or the spindle.

Note that the rotating curved surface body 24 is a conductor, and the second holding member 25 is
As a Y insulator, a conductive film 8a', as shown in FIG.
8b and 8c may be provided.

In addition, as shown in FIG. 9 or 1, the bottom surface of the first holding member B is a concave spherical surface concentric with the electrode contactor 2, and the second holding member 6 is provided with a rotating curved surface body 24. A conductive film may be formed on one side and an insulator may be formed on the other side.

Further, by turning off the switch SWy, the external switch function can be disabled. In this way, when a cutting fluid or the like is used for machining, erroneous position detection can be prevented due to conduction caused by the cutting fluid.

FIG. 13 shows still another embodiment of the present invention, in which the lead a IJl-73 of the internal switch is connected to a first OR circuit OR1, and its output is connected to a second OR circuit OR2 together with the output of an inverter circuit INV. ing.

In addition, the output of the first OR circuit OR1 is connected to the inverter circuit I.
Together with the input of NV, it is connected to an AND circuit AND, and the output of this AND circuit drives the alarm circuit AL1.

According to this implementation, if the internal switch is activated while the external switch is not activated (when the electrode contactor is not in contact with the workpiece), this abnormality will be detected by the alarm circuit AL, and an alarm will be generated. do.

As is clear from the detailed explanation of the invention, according to the present invention, OR is taken between the internal contact switch and the external contact switch, and both holding members of the electrode contactor are in line contact. , the contact surface is thick, and the amount of movement of the stylus is constant in any direction in the horizontal direction. Therefore, the position of the stylus is mechanically accurate, and since the electrode contactor is held at a constant position, it can be accurately detected by the output of the external switch. Moreover, even if there is an accident in which the external switch output cannot be obtained when the electrode contactor contacts, the internal switch output can be obtained, so a large error will not occur and an accident will not occur.

It is also possible to measure even if the object to be measured is an insulator.

[Brief explanation of drawings]

Fig. 1 (aL (b) is a schematic diagram showing an example of a conventional position detection device, Fig. 2 (b) is a schematic view showing an example of a conventional position detection device, Figure 3 is a block diagram showing an example of a position detection circuit using this conventional device, and Figure 4 (
aL (b), FIG. 5 and FIG. 10 are schematic diagrams showing one embodiment of the present invention, and FIG. 6 is a block diagram showing a position detection circuit using the embodiment. (b) is an explanatory diagram of the operation of the above embodiment; FIGS. 8, 9 and 11 are schematic diagrams showing main parts of other embodiments of the present invention;
FIG. 2 is an actual measurement graph showing the relationship between the operating stress S and the position detection circuit E, and FIG. 13 is a circuit diagram showing still another embodiment of the present invention. 21... Electrode touch, n... Stylus, Z3...
Disc, Sae...Rotating curved body, 26...Housing. Agent Patent Attorney Ei 1) Takeshi 3 Department 1. ..., ordinary (
'(Z:'>・ Figure 7 (0) (b) Figure 8 5 Figure 9 Procedural amendment filed in August 1980 by the Commissioner of the Japanese Patent Office Kazuo Wakasugi 1 Case description Patent application filed in 1988 No. 015880 2 Name of the invention Position detection device 3 Relationship with the case of the person making the amendment Patent applicant address Name Sony Magnescale Co., Ltd. 4 Agent 〒1
05 Address: Shiba 3-chome Building, 3-2-14 Shiba, Minato-ku, Tokyo Telephone: (03) 455-8746 Name: (7238) Patent Attorney Takeshi Nagata Department 5 Claims of the specification to be amended and claims of the invention Detailed (1) Claims of the present application are amended as follows. A position detection device configured to cause a change in conductivity between the object and the object to be measured due to contact with the object. The holding means comprises first and second holding members in pressure contact within the housing, the first holding member having a spherical surface concentric with the electrode contactor, and the second holding member forming a concentric spherical surface with the electrode contactor. Four membranes are formed on one side of the holding member so as to be in contact with the spherical surface, and the other side is made of an insulating material, and the stylus and/or the conductive film are connected to the workpiece and the electrode. 3. The position detection device according to claim 2, wherein the device is configured to detect a signal responsive to contact with a feeler. (3) A patent for a device in which the conductive film is provided at a plurality of divided positions on the one holding member, and the lead wires from each of the four conductive films and the stylus are connected to an OR circuit. A position detection device according to claim 2. (4) The position detection device according to claim 3, wherein a lead wire from the stylus is connected to the OR circuit via a switch. (5) The position detection device according to claim 3, wherein the position detection device is configured to generate an alarm when there is an output on the lead wire from the conductive film. (2) Extract pressure as shown below on page 6, lines 2 to 5 of the specification of the present application. ``Meanwhile, the conductive electrode stylus valve is held by a holding means in the housing, and the change in the four-electricity between the two due to contact between the electrode haptic and the object to be measured or the above tf1 to generate a signal in response to displacement of the holding means.
It is characterized by the fact that it has been achieved. The electrode contactor is made of, for example, a conductive sphere, and the holding means is made up of first and second holding members in pressure contact within the housing, the first holding member being "(3) Same page, line 11. Configured to emit ] Sode Sode Masaru.

Claims (1)

[Scope of Claims] (IJ) An electrode contact χ made of a conductive sphere is held by first and second holding members press-contacted in the housing via a stylus, the first holding member being the electrode contact The second holding member is in line contact with the concentric spherical surface, a conductive film is formed on one side of both holding members, and the other is made of an insulating material, and the second holding member is in line contact with the concentric spherical surface. A position detection device configured to detect a signal from a stylus and/or a conductive film in response to contact between a workpiece and an electrode contactor. (2) The conductive film is the force holding member. The position detecting device according to claim 1, wherein the position detecting device is provided at a plurality of divided positions above, and each conductive film and a lead wire from the stylus are connected to an OR circuit. 3) The position detection device according to claim 2, characterized in that a lead wire from the stylus is connected to the OR circuit via a switch. (4) An output to the lead wire from the conductive film. The position detection device according to claim 21A, characterized in that the device is configured to generate an alarm at certain times.