JPH0262003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact detection device, generally referred to as a touch probe, for electrically detecting contact of a contact with an object in an NC machine tool or a three-dimensional coordinate measuring machine. For this contact detection,
In addition to sensitively detecting contact, it is necessary for the contact to retreat accordingly when it hits an object, and to accurately return to its original position when the contact with the object is removed. , something small and easy to operate is desired.

Various contact detectors have been developed for this purpose. One example is the one shown in ``Measurement Probe'' (Special Publication No. 58-17402), in which the fulcrum when the contactor contacts the object to be measured and is displaced serves as both a return mechanism and an electrical contact. Therefore, since the fulcrum, which is normally undesirable to move, moves every time a measurement is made, it is not certain that it will return to its original position, making it unsuitable for high-precision measurements. The disadvantages include that the electrical contacts must be electrically conductive, and that manufacturing and adjustment is time-consuming.

The present invention has a simple structure, is small and lightweight, and always returns to an accurate return position, making it suitable for high-precision measurements. In the following explanation, we will explain a case in which the contact is displaced in the X direction, but if you combine these in two stages, the contact will be displaced in It is possible to detect this when it hits.

FIG. 1 is a diagram illustrating the principle of the present invention, in which a first movable member 3 is rotatably supported on a fixed portion 1 with a fulcrum 2. In FIG. Further, a second movable member 5 having a contactor 6 at its tip is rotatably supported by another fulcrum 4 in the fixed part. Between the fixed part 1 and the first movable member 3, there is a first
An electrical contact 7 is provided, and biasing means such as a tension spring 8 are provided for biasing the first movable member 3 in the direction of the fixed part 1 so that the first electrical contact is normally closed.
Further, a second electrical contact 9 is provided between the first movable member 3 and the second movable member 5, and the second movable member 5 is connected to the first movable member 3 so that the second electrical contact is normally closed. Biasing means, such as a tension spring 10, are provided for biasing in the direction.

Now, when a force in the -X direction in the figure is applied to the contactor 6 of the second movable member 5, the second movable member 5 rotates clockwise about the fulcrum 4 against the force of the tension spring 10 and moves to the second position. Open electrical contact 9. When the force in the -X direction is released, the second movable member 5 returns to its original position by the action of the tension spring 10. Conversely, the second movable member 5
When a force in the +X direction in the figure acts on the contactor 6, the second movable member 5 rotates counterclockwise around the fulcrum 4 and pushes the first movable member 3 via the second electric contact 9. Therefore, the first movable member 3 rotates counterclockwise about the fulcrum 2 against the force of the tension spring 8 to open the first electrical contact 7. When the force in the +X direction is released, the first movable member 3 returns to its original position by the action of the tension spring 8.

What is shown in FIGS. 2 and 3 is one embodiment of a contact detection device that is practically compactly constructed based on the principle of the present invention shown in FIG. 1 and its explanation. Components that are the same as those in the figures will be described using the same numbers. 1 is a fixed part forming an outer cylinder of the contact detection device. 3 is fulcrum 2
5 is a first movable member rotatably supported by the fixed part 1 at a fulcrum 4, and a second movable member 5 is rotatably supported by the fixed part 1 at a fulcrum 4, and its tip is in contact with the first movable member. Child 6 is provided. Reference numeral 11 denotes a contact pin which is electrically insulated and implanted in a protruding portion 12 in the fixed part 1 with an insulating bushing 13, and a first electric wire is connected between this and the first movable member 3 located at a position opposite to the contact pin. A contact point 7 is formed. Reference numeral 14 denotes a contact pin that is electrically insulated and implanted in an insulating bushing 15 at the end opposite to the contactor 6 of the second movable part 5, and the first movable member located at a position opposite thereto. A second electrical contact 9 is formed between the two. 8 is a tension spring that urges the first movable member 3 in the direction of the protruding portion 12 about the fulcrum 2, and 10 is a tension spring that urges the second movable member 5 about the fulcrum 4. It is a tension spring that biases in the direction of. Therefore, at all times, that is, when no external force is applied to the contactor 6 in the +X direction or the -X direction, the contact pin 11 and the first movable member 3 and the contact pin 14 and the first movable member 3 are in contact, as shown in the figure. As shown, the second movable member 5 maintains a vertical position with respect to the fixed part 1, that is, the original position. 16 and 17 are contact pins 11 and 1, respectively.
4 is led to the outside of the fixed part 1 and connected to a power source (not shown), and therefore the cord 1
6, contact pin 11, first movable member 3, contact pin 1
4. It constitutes a series electric circuit consisting of cords 17.

In such a structure, the right side of the contactor 6 is now in contact with the object to be measured (not shown), and the contactor 6 is -
When moving in the X direction, the second movable member 5 rotates clockwise about the fulcrum 4 against the tensile force of the tension spring 10, and the contact pin 14 and the first movable member 3 are separated and electrically disconnected. Continuity is interrupted. In other words, when the contactor 6 contacts the object to be measured and is displaced in the -X direction, the conduction of the second electrical contact 9 is interrupted at that moment. The position of an object can be detected with high accuracy. Next, when the contact between the contact 6 and the object to be measured is released, the second movable member 5 rotates counterclockwise under the action of the tension spring 10 until the contact pin 14 comes into contact with the first movable member 3. Child 6 returns to the origin position.

Next, the left side of the contact 6 contacts the object to be measured, and when the contact 6 moves in the +X direction, the second movable member 5 rotates counterclockwise around the fulcrum 4, and the contact pin 14 moves to the first movable position. In order to push the member 3, the first movable member 3 rotates counterclockwise around the fulcrum 2 against the tensile force of the tension spring 8, and moves away from the contact pin 11 to release the electrical power of the first electrical contact 7. Continuity is interrupted, and the position of the object to be measured can be detected with high accuracy as in the case described above. Next, when the contact between the contactor 6 and the object to be measured is released, the first movable member 3 rotates clockwise under the action of the tension spring 8 until it comes into contact with the contact pin 11, and the second movable member 5 also rotates at the same time. The contactor 6 then returns to its original position.

In addition, also in the above embodiment, the fulcrums 2 and 4
Although the explanation is given using a bearing as an example, it is of course not limited to this, and it is possible to use a leaf spring, a cross spring, etc. as appropriate.

As detailed above, according to the contact detection device of the present invention, the second movable member having the contact element contacts the object to be measured and is displaced in the +X direction and the -X direction using the same fulcrum, and By using a structure in which the fulcrum and the electrical contact are provided separately, the moment when the contact contacts the object to be measured and is displaced can be detected with high precision as an electrical signal. The excellent effect of being able to quickly and accurately return to the original position when the contact with the object was released was achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a sectional side view of one embodiment of the present invention, and FIG. 3 is a sectional view taken along the line -- in FIG. 1: Fixed part, 3: First movable member, 5: Second movable member, 6: Contactor, 7: First electric contact, 9: Second
electrical contacts.

Claims (1)

[Claims] 1 A fixed part, a first movable member pivotally supported by the fixed part, a biasing means for biasing the first movable member toward the fixed part, and a first
A first electrical contact provided between the movable member and the fixed part, a second movable member that is pivotally supported by the fixed part and has a contact at its tip, and an urging force that biases the second movable member toward the first movable member. A contact detection device comprising a force means and a second electrical contact provided between a first movable member and a second movable member.