KR19980042511U - Non-contact Capacitive Trigger Probe - Google Patents

Abstract

When the lower end of the probe made of a conductor approaches an object to be measured made of the same conductor, electric conduction is applied to both ends thereof, thereby generating a potential difference due to static electricity. The present invention relates to a non-contact capacitive trigger probe capable of detecting a position, wherein a probe for detecting a measurement position and a measuring object to which the probe contacts each other are electrically connected to each other to allow static electricity to be contacted with each other. A trigger signal is generated by a potential difference of and is supported by a hinge ring having an elastic member for returning to an upright state while supporting the probe rod formed by the probe in a 360 ° range. And a stopper having an appropriate interval LR to limit the movement range in the vertical direction.

Description

Non-contact Capacitive Trigger Probe

The present invention provides a potential difference between a non-contact capacitive trigger probe, and more specifically, a lower end of a probe made of a conductor, which conducts electricity at both ends of the probe when the object is being approached by the same conductor, thereby generating a potential difference due to static electricity. It is about a non-contact capacitive trigger probe which can detect a measurement position in a non-contact state by the change of.

In general, a trigger probe is a kind of switching touch probe used in a coordinate measuring machine (CMM), and is attached to the tip head of the meter to be in contact with the object to be measured and a relative displacement occurs. It has the function to find the position of the measuring point by sending the electrical signal of ON and OFF. The three-point touch trigger probe is the simplest in structure and widely used (used in more than 90% of the CMMs produced worldwide), and its structure is measured using the lever principle as shown in FIG. (M) and the transducer (Stylus) is to contact the contact position through the radius correction of the transducer (S) is to know. Briefly describing the structure of the three-point probe, as shown in Fig. 2, the portion S that probes the object to be measured by the spring 2 at the probe body 1 and the three contacts S1, S2, S3. It is designed to be supported by a constant force, and these contacts are connected in series to form a close circuit as in (b). If the transducer S contacts the object and is biased in one direction and any of the three contacts are shorted (the transducer moves back and forth or upwards), the electrical circuit opens to generate a signal to store the coordinate position. .

Since the current trigger probe uses the lever principle of three contacts, the trigger time for generating a signal varies slightly depending on the direction of contact. That is, Figure 3 is an example of the trigger delay generation measurement data according to the measurement direction of the current three-point contact trigger probe, which is a trigger signal generated by contacting the contact probe in various directions at 360 ° randomly from the outside of the cylinder It shows the time until and shows the difference of delay error in three directions (P1, P2, P3) of 360 ° as shown in the figure. When the three-point probe is used in the CMM, the error of the delay time is eventually represented as an error in the coordinate distance of the CMM, and numerically, the magnitude of the error reaches about 10 μm. Cause. The directionality of these probes is called lobbing error in ASME, which specifically defines the measurement error of probes.

The purpose of the present invention is to provide a non-contact capacitive trigger probe capable of detecting a position by a potential difference by flowing electricity to the probe and the object under measurement.

The present invention for achieving this purpose, by electrically conducting the probe for sensing the measuring position and the measuring object to which the probe is in contact with each other to generate a trigger signal due to the potential difference of the capacitance (electrostatic capacitance) during mutual contact The support rod is supported by a hinge ring having an elastic member for returning to the upright position while supporting the detection rod formed by the probe in a 360 ° range, and restricting the movement range in the left and right directions and the vertical direction on the upper side of the detection rod. By placing a stopper having an appropriate interval (LR), the probe formed on the lower end of the detection rod is characterized in that the detection position by contacting the object to be measured.

No content

1 is a cross-sectional configuration diagram illustrating a signal generation principle of a general trigger probe;

Figure 2 (a) (b) is a conventional three-point trigger probe and its circuit configuration,

3 is a diagram illustrating directional error data of the three-point trigger probe;

4 (a) (b) is a non-contact capacitive trigger probe structure of the embodiment of the present invention and a partial detail thereof,

5 (a) (b) is a block diagram showing another embodiment of the present invention, respectively.

Explanation of symbols on the main parts of the drawings

10: probe body 11: support

20: detection rod 21: probe

30: hinge ring 31: elastic member

40: Stopper M: Object to be measured

Hereinafter, the non-contact capacitive trigger probe of the present invention will be described with reference to the accompanying drawings.

4 is a detailed view of the structure of the capacitive trigger probe according to an embodiment of the present invention, and a detection rod 20 is installed vertically through a hollow portion of the probe body 10, and the detection rod 20 is installed. At the bottom of the bottom, a probe 21 of a conductor through which electricity flows is formed.

The detection rod 20 is bonded to the elastic member 31 of the hinge ring 30 attached to the lower end of the probe body 10 to support the probe 21 to return to its original state after the probe 21 at the lower end of the detection rod is operated. .

The upper end of the detection rod 20 penetrates through the stopper 40 attached to the support 11 of the probe body 10, and between the inner circumferential surface of the stopper 40 and the protrusion 22 formed on the detection rod 20. The proper interval (LR) is formed to limit the operating range of the detection rod (20).

In the above, the stopper 40 is positioned on the upper side of the detection rod 20 and the hinge ring 30 is positioned on the lower side, but the hinge ring 30 is positioned on the upper side, but the stopper ( It is also possible to position 40 (see FIG. 5 (a)).

On the other hand, by flowing electricity to the object to be measured (M) by changing the resistance (R) by contact with the electricity flowing in the probe 21 to measure the electromotive force.

In addition, it is also possible to visually measure the electromotive force by turning on the lamp by the contact between the object to be measured M and the electricity flowing through the probe 21 (see Fig. 5 (b)).

Therefore, the tip of the probe 21 approaches the object to be measured and moves in the vertical and inclined and oblique directions to the left and right directions, so that the probe 21 made of a conductor approaches the object M of the same conductor. , Both ends of the static electricity (Capacitance) is generated, thereby causing a potential difference in the circuit. At this time, the generated static electricity C is inversely proportional to the approach distance X (C = A / X, A: proportional constant), and the change in the potential difference V can be measured. Therefore, when a certain potential difference is reached, a trigger signal may be generated or used as a signal to connect the signal to a lamp for viewing.

After the probe is moved above a certain potential value, no further trigger signal is generated, which is a function of a non-contact on / off sensor.

In this case, the elastic member 31 formed in the hinge ring 30 of the probe body 10 to support the detection rod 20 moves the probe 21 to its original position after the front and rear, right and left close movements of the probe 21. It works to restore.

The stopper 40 serves to protect the probe 21 while limiting the movement range in the front, rear, left and right directions of the probe 21. Proximity distance S for the left and right trigger of the probe 21 is the distance between the distance between the probe 21 and the stopper 40 L1 / L2 and the stopper 40 around the hinge ring 30 ( LR) to adjust (LR x L1 = S x L2). At this time, the distance of the stopper 40 is slightly larger than the left and right proximity distance (S) by adjusting the L1 / L2, the proximity distance for the trigger in the vertical and inclined direction of the probe slightly less than the interval of the stopper 40 probe Protect the child.

The present invention is practically simple and useful since many three-dimensional measuring objects are metals, i.e., conductors, processed from a machine. The difference in conductivity of the metal will affect the time when the trigger signal is generated. Therefore, this value can be compensated by measuring the trigger generation delay time according to the conductivity of the object under test. In the case of specimens made of the same material, the trigger probe of the present invention does not generate an error due to delay time in any direction.

In addition, there is an effect that can accurately and quickly detect the position of the object under measurement.

Claims (3)

A detection rod 20 installed vertically through the hollow portion of the probe body 10 and having a probe 21 formed of a conductor through which electricity flows; It is attached to the lower end of the probe body 10 to support the detection rod 20, is bound to the elastic member 31 to the inner peripheral surface to return to the original state after the probe 21 of the lower detection rod 20 is operated A hinge ring 30 having an elastic member 31; A stopper (40) attached to the support (11) of the probe body (10) to maintain an appropriate interval (LR) between the protrusions (22) to limit the operating range of the detection rod (20); Non-contact capacitive trigger probe (Trigger) characterized in that the electromotive force is measured by flowing electricity to the object to be measured (M) by changing the resistance (R) by contact with electricity flowing in the probe 21 Probe). The method of claim 1, Non-contact capacitive trigger probe (Trigger Probe), characterized in that the hinge ring 30 is located on the upper side of the detection rod 20, the stopper 40 is located on the lower side. The method of claim 1, Non-contact capacitive trigger probe (Trigger Probe) characterized in that the electricity flowing in the object to be measured (M) and the electricity flowing in the probe 21 is turned on to turn on the lamp to visually measure the electromotive force.