DE10030570A1 - Probe pin release method in coordinate measuring instrument, involves converting collision detection signal to trigger pulse for activating gas generator to release pin - Google Patents

Abstract

The collision detection signal output from a sensor is converted to trigger pulse for activating a gas generator, for active release of a receptacle (26) of a probe pin (27) from the probe. An Independent claim is also included for coordinate measuring instrument.

Description

The invention relates to a method for fast soldering sen a stylus from a probe of a coordinates measuring device and a coordinate measuring machine for implementation of the procedure.

The travel speed of coordinate measuring machines is getting faster and faster these days, because with shorter measurements times the number of workpieces that can be measured nen, increased.

With the faster process, the problem arises that the braking distance in case of possible collisions is getting longer becomes. It is necessary to protect the probe here.

According to the prior art (EP 0 548 328 B1) is a Probe known in which a button by magnetic force on Probe is stored. In the event of a collision, the magnet overcome, and the button detaches from the button head. This probe belonging to the prior art has the disadvantage that only very light buttons, for example up to a weight of 20 grams can be used. Heavier probes are pushed through during normal probing the magnetic force was not maintained. So in the event of a collision however, when the button is released, the holding force is allowed do not exceed a certain limit.

This probe belonging to the prior art has furthermore the disadvantage that the interface between the push button and probe due to the limited holding force is "soft".  

Another disadvantage of this ge to the prior art hearing probe is a passive free in the event of a collision. That means: Will the Hal If the force is exceeded by the external force, the Button. An adjustment of the holding force and thus the Collision trap on the push button maximum force is not possible or only by replacing the magnet.

The technical problem underlying the invention consists of a method and a coordinate measuring machine specify where the probe is despite a high travel speed is protected even in the event of a collision with high holding forces of the stylus.

This technical problem is solved by the procedure the features of claim 1 and by the coordinates solved with the features of claim 2.

The fact that according to the invention the stylus take on the probe is designed such that the Stylus released very quickly in the event of a collision the probe is well protected in the event of a collision.

This means that the stylus holder from the usual three-point support is solved very quickly.

The fact that according to the invention an active release of the probe, it is possible to have a rigid one Connection between a probe and a stylus very much to solve quickly.

The method according to the invention has the advantage that the collision force at which the stylus is released is adjustable because the sensor device is a collision  recognizes, and then that of the sensor device device emitted electrical signal into a mechanical Trigger pulse is implemented.

The sensor device can be used, for example, as a path measurement device, as an acceleration sensor, as a pressure sensor or the like.

According to the invention, it is possible to use any button to arrange on the probe and the probe in collision trap to protect anyway, because one still rigid connection between the probe and the stylus given is.

A pneumatic is advantageous for quick opening or hydraulically actuated device is provided. The device can be pneumatic or hydraulic acted upon piston. For control of the pneumatic piston is advantageously at least one Gas generator provided.

However, the device can also be an energy store in the form of an explosive pill (gas generator) or at least have a preloaded spring in the event of a collision the stylus holder releases very quickly.

It is also possible that the device at least a pull magnet, at least one piezo element, at least a magnetostrictive or electrostatic element has.

As already stated, the device can be of a kind Provide airbag system. Here, a so-called Explosive pill (gas generator) above the piston on which  again a hook for tensioning the stylus holder is provided. This detonating pill or detonating pills can in the millisecond range to a volume of ten Ku generate a pressure of up to five bar. in the In the event of a collision, the stylus explo released in sions. In the event of a collision can thereby the connection between the stylus and the probe can be released very quickly by the gas Exerts pressure on a mechanical device, for example point to the piston with the hook, which is in normal contact if the stylus holder is fixed in their bearings.

Generally speaking, it is required according to the invention Lich to provide an energy store that the energy in Collision trap releases spontaneously.

The existing in the probe and in the coordinate measuring machine NEN sensor devices allow according to the invention Collision detection. By editing this Signals can be criteria to suit the individual button for collision detection automatically vote and monitor. These criteria include: Off steering, bending, speed and acceleration.

If a collision is detected, a signal for mechanical release of the stylus holder is given. The implementation of the electrical signal in a mechanical release can be done in different ways:

• - Control of a pneumatic or hydraulic Kol bens via a valve;
• - Control of at least one pull magnet, at least egg Nes piezo element, at least one magnetostrictive Element or at least one electrostatic Ele mentes;  
• - Control of a pneumatic piston via a gas generator (detonating pill).

Further details of the invention can be found in the Unteran sayings are taken.

In the drawing is an embodiment of the He shown, namely:

Figure 1 shows a device for quickly releasing a stylus with an external gas generator in section.

Figure 2 shows a device for quickly releasing a stylus with a spring in section.

Figure 3 shows a device for quickly releasing a stylus with an explosive pill (gas generator) in section.

Fig. 4 is a representation of a mechanical connec tion probe probe pin in section.

Fig. 1 shows a coordinate measuring machine ( 1 ) with a probe ( 2 ) on which a stylus ( 4 ) is arranged via a stylus holder ( 3 ). The stylus holder ( 3 ) is arranged with a known three-point bearing ( 5 ) on the probe ( 2 ). A hook ( 6 ) pulls the stylus holder ( 3 ) in the direction of arrow (A) by means of a spring ( 7 ) and fixes it in the three-point bearing ( 5 ).

For quick release of the stylus retainer (3) from the probe (2), a gas generator (8) is provided, which effects via a valve (9) in case of collision in a flash, a pressure increase in a space (10). The valve ( 9 ) is controlled by a computer ( 11 ). The computer ( 11 ) controls the valve ( 9 ) as soon as position measuring systems ( 12 ) of the coordinate measuring machine and / or the probe ( 2 ) detect a collision.

In the event of a collision, a piston ( 16 ) with the hook ( 6 ) is moved very quickly in the direction of the arrow (B) and thus releases the stylus holder ( 3 ) and the stylus ( 4 ).

Fig. 2 shows a probe ( 13 ) on which the probe pin holder ( 3 ) with the stylus ( 4 ) on the three-point storage ( 5 ) is mounted. For quick release, a preloaded spring ( 14 ) is provided, which is actuated via a control ( 15 ) in the event of a collision and releases the stylus holder ( 3 ) in the direction of arrow (C) in a flash.

Fig. 3 shows a device ( 17 ) with a piston ( 18 ) arranged in the device ( 17 ). On the piston ( 18 ), a hook ( 19 ) is arranged, which takes a Taststiftauf ( 20 ) of a stylus ( 21 ) in bearings ( 22 ).

In a room ( 23 ) above the piston ( 18 ), an explosive pill (gas generator) ( 24 ) is arranged, which is triggered by a path measuring device (not shown) via a line ( 25 ).

Due to the pressure building up in the room ( 23 ), the piston ( 18 ) with the hook ( 19 ) is moved in the shortest possible time in the direction of the arrow (D) and thus releases the stylus holder ( 20 ).

Fig. 4 shows a stylus ( 26 ) released after a collision with a stylus ( 27 ). The design of a receptacle ( 28 ) in the form of a pot ( 29 ) arranged on the probe head ensures that the probe pen receptacle ( 26 ) can move freely via a hook ( 30 ), but does not fall out of the probe and may be damaged in the process. It is also avoided that the stylus ( 27 ) with the stylus holder ( 26 ) falls on a workpiece (not shown).

Characterized in that the pot ( 29 ) of the hook ( 28 ) is also closed since Lich, the stylus holder ( 26 ) can perform a pendulum movement in the direction of arrow (E) with the button ( 27 ).

reference numerals

1

coordinate measuring machine

2

probe

3

stylus retainer

4

feeler

5

Three-point mounting

6

hook

7

feather

8th

inflator

9

Valve

10

room

11

computer

12

displacement measuring system

13

probe

14

feather

15

control

16

piston

17

contraption

18

piston

19

hook

20

stylus retainer

21

feeler

22

camp

23

room

24

busting pill

25

management

26

stylus retainer

27

feeler

28

admission

29

pot

30

hook
A, B, C, D, E arrows

Claims (9)

1. A method for quickly releasing a stylus from a probe head of a coordinate measuring machine, characterized in that we at least one sensor device ( 12 ) provided in the coordinate measuring machine ( 1 ) and / or probe head ( 2 ) detects a collision that the sensor device ( 12 ) a signal for the automatic, active release of the stylus ( 4 ) is given, that the electrical signal is converted into a mechanical triggering pulse of the stylus ( 4 ), and that the active release of the stylus ( 4 ) takes place. 2. Coordinate measuring device for performing the method according to claim 1 with a probe and a detachably arranged on the probe stylus, characterized in that a device ( 8 , 9 ; 14 ; 24 ) for automatic quick release of the stylus ( 4 ) from Probe ( 2 ) is provided. 3. Coordinate measuring device according to claim 2, characterized in that the device ( 8 , 9 ) for releasing is designed as a pneumatically and / or hydraulically actable on device. 4. Coordinate measuring device according to claim 3, characterized in that a pneumatically and / or hydraulically actuated piston ( 16 ) is provided. 5. Coordinate measuring device according to claim 4, characterized in that for controlling the pneumatic Kol bens ( 16 ) at least one gas generator ( 8 ) is provided. 6. Coordinate measuring device according to claim 2, characterized ge indicates that the device has at least one gas has nerator. 7. Coordinate measuring device according to claim 2, characterized in that the device has at least one pre-tensioned spring ( 14 ). 8. Coordinate measuring device according to claim 2, characterized ge indicates that the device at least one Zugmag neten, at least one piezo element, at least one magneto strict or at least one electrostatic element having.   9. Coordinate measuring device according to claim 2, characterized in that the probe has a cup-shaped receptacle ( 29 ) for a connecting element ( 30 ) of the stylus holder ( 26 ).