WO2011020867A1

WO2011020867A1 - Measuring apparatus and method for measuring large components

Info

Publication number: WO2011020867A1
Application number: PCT/EP2010/062070
Authority: WO
Inventors: Frank HÄRTIG; Bernd Kuhfuss; Rudolf Meess
Original assignee: Universität Bremen
Priority date: 2009-08-19
Filing date: 2010-08-18
Publication date: 2011-02-24
Also published as: DE102009037830B3

Abstract

The invention relates to a measuring apparatus for measuring large components (10), comprising a measuring device and a drive unit (12) for actuating the measuring device. The invention further relates to a method for measuring large components (10) with such a measuring apparatus. The aim of the invention is to be able to measure large components (10) simply and inexpensively. To achieve this, the measuring apparatus according to the invention is characterized in that the measuring unit has a passive measuring arm (11) which has a reference point (13) that is fixed relative to the component (10), and in that the drive unit (12) can be moved and fixed on the component (10) and has a first drive (22) for the measuring arm (11), with which the measuring arm (11) can be coupled, and a second drive (35), with which the drive unit (12) can be moved on the component (10). The components (10) are measured with such a measuring apparatus in that the component (10) is measured in two or more measurement intervals, the drive unit (12) is positioned and fixed on the component (10) for each measurement interval, the measuring arm (11) which is coupled to the drive unit (12) is actuated by means of the drive unit (12), and a region of the component (10) is thereby measured.

Description

description

Measuring device and method for measuring large components Technical field

The invention relates to a measuring device for measuring large

Components with a measuring device and a drive unit for

Actuation of the measuring device. Furthermore, the invention relates to a method for measuring large components with such

Measuring device.

State of the art

Such a measuring device is known from DE 36 43 296 A1 or the

JP 02 151 708 A known.

The measurement of large components in stationary measuring devices poses the problem that the large components to the stationary

Measuring device must be transported. In addition, the stationary measuring devices must be large enough to accommodate the components can. They usually point next to the three

Cartesian basic axes still an integrated round table to

Moving the component within the measuring device. Such

Measuring devices are therefore very expensive and also the transport of the large component to these measuring devices is associated with correspondingly high cost.

To avoid these disadvantages, DE 36 43 296 A1 and JP 02 151 708 A propose measuring devices which can move along the component and measure the component during this movement. These measuring devices can therefore be made correspondingly small. In this case, the movement of the measuring device on the workpiece in the sense of a feed movement is imperative to a

Generate measurement track. Without this movement, only a singular reading would be obtained. The movement of the measuring device along the component is thus included in the survey. This is at the expense of accuracy. Reasons are that components of

Measuring device for transmitting the driving forces must be formed according stiff and possible slippage during movement the measuring device on the component.

From GB 746 586 is a device for measuring the

Involute form of a toothing known. This measuring device is fixed to the component and then measures the involute form of the

Toothing. This measuring device is also small and mobile. But it is only suitable for measuring the

Gears within their measuring range. An extension of the measuring range is only possible by disassembling the measuring device from the component and fixing it in another position. This is expensive. In addition, the measuring device after the

Reactivate to be recalibrated to the measurements on the

prior measurements.

Presentation of the invention

On this basis, the invention is based on the problem, a

To provide measuring device with which large components can be measured in a simple and cost-effective manner with maximum accuracy. Furthermore, a simple and cost-effective method for measuring these components with such a measuring device is to be proposed.

To solve this problem, the measuring device according to the invention is characterized in that the measuring unit has a passive measuring arm, which has a fixed reference point with respect to the component, and that the drive unit is implementable and fixable on the component and a first drive for the measuring arm, which can be coupled with the measuring arm, and has a second drive with which the drive unit can be moved on the component. The invention

Method is for solving the problem characterized in that the component is measured in two or more measuring intervals by the drive unit is positioned and fixed to the component for each measurement interval, actuated by the drive unit coupled to the measuring arm by means of the drive unit and thereby measure an area of the component becomes.

The basic idea of the invention is that no longer the component too a stationary measuring device, but a small and mobile measuring device is brought to the component. A complex transport of the component is eliminated. According to the invention, the drive for moving the measuring arm on the one hand and the measuring arm on the other hand are decoupled from each other. Accordingly, the measuring arm is itself passive. So he has no own drive organs, which move him during the determination of the measured values. This allows the components of the measuring arm to be manufactured easily and with high precision. Game and other influences at the expense of accuracy can therefore be largely avoided. The drive for the measuring arm is assigned to the drive unit. As a result, the measuring arm is within the due to the dimensions of the drive unit

predetermined, maximum measuring range moves. As soon as the component is detected within this measuring range, the drive unit is repositioned and fixed on the component. This results in a new one

Measuring range on the component, which can now be measured. This

The process of measuring and repositioning the drive unit is repeated until the component is measured. It is meant by "measuring" not only a complete measurement of the component, but rather also individual sections or areas of the component. The extent to which the component is measured depends on the respective component

Measuring task.

Furthermore, according to the invention, the measuring arm has a fixed reference point relative to the component. This can be a single fixed reference point, which remains unchanged for the measurement of the entire component. However, different fixed reference points can also be provided. These then apply to one or more measurement intervals. It is only important that the respective position of the reference points is known in advance, in particular with regard to their relative position to each other. Calibration of the measuring device during the measurement of the component or for each measuring interval can therefore be omitted. This also simplifies the measurement of large components.

If two or more reference points are present, the position of the first and optionally further reference points in the measurement of the component are determined, while the measuring arm is just assigned to the first reference point. The determination of the position then takes place at a measuring interval in which one or more of the further reference points are located in the region which can be reached by the respective position of the drive unit. If not all the reference points can be reached while the measuring arm is assigned to the first reference point, the position of the remaining reference points can take place at a later measuring interval if the measuring arm is assigned to another reference point already known with respect to its position. The reference point to which the measuring arm is currently assigned is referred to as the active reference point in the context of this application.

The measuring arm is assigned a feeler for measuring the component.

This may be a mechanical probe, a laser, or any other suitable positioning device, such as a mini-GPS. This feeler is preferably by the measuring arm

three-dimensional, so in all directions, kept movable. If it is sufficient for the respective measurement output, under some circumstances only a two-dimensional mobility of the sensing element is sufficient. In rare cases, if, for example, only the concentricity of a large

Under some circumstances, only a one-dimensional mobility of the tactile organ, such as the

Turnability about an axis.

The three-dimensional mobility of the measuring arm is achieved in a particularly simple manner, characterized in that the measuring arm has a rotatable about a first axis turntable on which a telescopic arm is pivotally mounted about a second axis. The second axis is arranged in particular perpendicular to the first axis. Furthermore, the telescopic arm carries at its free end the probe element. By rotating the fifth wheel about the first axis and pivoting the telescopic arm about the second axis and extending and retracting the telescopic arm, the probe element can be moved in all three dimensions.

After a structural embodiment of the invention, the telescopic arm provided with at least one telescopic outer tube, in which a

Telescope inner tube is guided in and out. One of these tubes, preferably the telescopic outer tube is pivotable on the

Bogie stored while the other tube carries the probe element. Carries the telescopic inner tube, the probe element, the tapered

Telescopic arm to the probe element, which the accessibility too

measuring points on the component easier.

In order to move the passive measuring arm, the drive unit has a first drive, by means of which the probe element is three-dimensionally movable driven. This first drive preferably has three each movable at a certain angle to each other carriages. This results in a particularly simple structural design for the drive. Alternatively, however, any other suitable construction may be provided. For example, the drive also similar to the measuring arm with turntable and swiveling telescopic arm

be more educated. Conversely, the measuring arm can be designed analogous to the drive with at a certain angle to each other movable carriage. In a three carriage design, the first carriage is preferably in a first direction, the second

Carriage in a second direction and the third carriage in a third direction movable. The predetermined angle at which the

Sleds are movable, in particular, the right angle. This results in a simple and accurate kinematics for the method of the carriage.

Furthermore, the drive unit according to another constructive

Embodiment of the invention on a frame, which in turn is movably attachable to the component. By means of the frame can be the

Drive unit performed on the component, which allows a particularly simple conversion of the drive unit after a measurement interval. The frame can be moved, for example, manually by an operator on the component. Preferably, however, the frame has a second drive for moving the drive unit on the component. This drive has a structural design over at least a motor driven roller. This can transmit their driving forces either non-positively or positively on the component.

As a first drive for actuating the measuring arm on the one hand and as a second drive for displacing the drive unit on the other hand, separate drives can be used in each case. But it is also conceivable that a common drive is provided by means of suitable

Clutches once to operate the measuring arm and then to

Versetz the drive unit is used.

Brief description of the drawings

The invention will be described below with reference to the drawing

illustrated embodiment illustrated. In the drawing show:

1 shows a measuring device with the features of the invention together with a component to be measured in a perspective view,

2 shows the measuring device according to FIG. 1 in plan view,

3 shows the measuring device according to FIG. 1 in side view,

FIG. 4 shows the measuring device according to FIG. 1 in a vertical section in the plane IV-IV according to FIG. 2.

Way (s) for carrying out the invention

In the following description, the invention is based on the

Measurement of a gear 10 with internal teeth as to

Examining component explained. For the sake of simplicity, the toothing of the gear 10 is shown only incomplete, although the gear 10 is provided at its entire circumference with the toothing. The measuring device has a passive, not provided with its own drives measuring arm 11 and a drive unit 12. The measuring arm 11 has a turntable 13 which is fixed but rotatably mounted about the axis of rotation of the gear 10. The turntable 13 thereby forms a fixed reference point for the measurement of the gear 10th

On the turntable 13, a telescopic arm 14 is pivotally mounted. The pivot axis of the telescopic arm 14 is perpendicular to the axis of rotation of the fifth wheel 13 and thus of the gear 10 is arranged. Of the Telescopic arm 14 has a telescopic outer tube 15, which is pivotally mounted on the turntable 13, and a telescopic inner tube 16. The telescopic inner tube 16 is slidably guided in the telescopic outer tube 15 in its longitudinal direction. The telescopic inner tube 16 is so against the telescopic outer tube 15 and extendable. At the

Teleskoparm 14 but this is not provided own drive means. Also, for rotating the fifth wheel 13, the measuring arm 11 has no own drive means. It is a passive measuring arm 11.

The drive unit 12 has a frame 17, which consists of a

Base plate 18, two perpendicular to the base plate 18 extending and attached to the base plate 18 longitudinal member 19, 20 and the two free ends of the side members 19, 20 connecting cross-beam 21 is made. The crossbeam 21 extends substantially parallel to

Base plate 18th base plate 18, the side members 19, 20 and the

Crossbar 21 form a closed frame 17. The frame 17 is designed so that it can clamp a portion of the component to be measured, in the present case an arc portion of the gear 10. In the present case, the corresponding

Arc portion of the gear 10 between the base plate 18 and the crossbeam 21 clamped. As a result, the frame 17 and thus the drive unit 12 is fixed to the gear 10.

On the base plate 18, a drive 22 is provided for the measuring arm 11.

This drive 22 consists in the present case of three mutually perpendicular carriages 23, 24, 25, which are in the manner of a Cartesian coordinate system in an x-direction, a y-direction and a z-direction against each other displaceable. For this purpose, a carriage bed 26 is arranged on the base plate 18, which is associated in the present case, the y-direction. On this carriage bed 26, the first carriage 23 is slidably guided in the y direction, which in turn has on its upper side a second carriage bed 27, which is associated with the x-direction. At this carriage bed 27, the second carriage 24 is guided displaceably in the x direction. This slide 24 is formed as an elbow and carries a third, the z-direction associated carriage bed 28. At this carriage bed 28, the third carriage 25 is slidably guided in the z direction. For moving the carriages 23, 24, 25 on the respectively associated carriage bed 26, 27, 28 suitable and known drive means 29 are provided.

On the third carriage 25 is a drive-side coupling arm 30th

attached, at its free end a drive-side

Clutch element 31 carries. At the telescopic arm 14, namely at

Telescopic inner tube 16, a messarmseitiger coupling arm 32 is arranged, which has a messarmseitiges at its free end

Clutch element 33 carries. The coupling elements 31 and 33 are mutually complementary coupling elements which can be coupled together. In the drawing, they are shown in coupled condition. The coupling elements 31 and 33 form a

Ball joint, so that the coupling arms 30 and 32 against each other in any direction can be pivoted. Alternatively, they may also form a universal joint or other joint providing the required degrees of freedom. The position of the measuring arm 11 should only be determined to a certain extent by the drive 22.

By means of the drive 22 can now be the measuring arm 11 in one

predetermined range, which corresponds to the area defined by the frame 17 in the present case, move. At the free end of the

Telescopic inner tube 16 is a probe 34 is provided, which is moved by means of the drive 22 at the corresponding portion of the gear 10 along. In this case, this area of the gear 10 is measured.

Suitable position sensors continuously determine the position of the

Probe relative to the reference point (turntable 13). This can be done for example by the fact that the turntable 13, an angle sensor for detecting the rotation angle of the fifth wheel 13 and another angle sensor for detecting the pivot angle of the

Teleskoparms 14 is provided opposite the turntable 13. Another sensor detects the extent to which the telescopic inner tube 16 is extended from the telescopic outer tube 15. With these sizes is the position of the probe 34 uniquely determined. The individual components of the measuring arm 11 are highly accurate, that is made without play. A possible play and inertia of the drive 22 have by the decoupling of the measuring arm 11 and drive unit 12 has no influence on the measurement accuracy.

The drive unit 12 has a second drive, with which it can be moved along the gear 10. For this purpose, two rollers 35 are provided on the base plate, which are each arranged adjacent to the longitudinal members 19, 20. At least one of these rollers 35 is driven by a motor, so that the drive unit 12 can be moved on the gear 10. At the crossbeam 21 are also

adjacent to the longitudinal members 19, 20, two counter-rollers 36 are arranged, which additionally guide the drive unit 12 and serve as counter-pressure elements in fixing the drive unit on the gear 10. A possible slip in the process of the drive unit 12 on the gear 10 in turn has no influence on the measurement accuracy by the decoupling of the measuring arm 11 and drive unit 12. Therefore, it would also be possible, but not preferred, to perform 12 measurements during the drive unit 12 process.

Now, as defined by the frame 17 area of the gear

10 is measured, the drive unit 12 is further moved by means of the second drive and fixed again on the gear 10. Now, the new, now defined by the frame 17 area of the gear 10 can be measured. Subsequently, the drive unit 12 is moved again. This process is repeated until either the entire gear 10 or predetermined areas of this gear are measured. The measuring of each of these areas forms a measuring interval.

With the present measuring device, the gear 10 can be

Fully automatic, for example, computer-controlled, measured. But it is also conceivable semiautomatic operation, in which the

Drive unit 12 via no second drive for moving the

Drive unit 12 has, but is offset by an operator. The operator then forms, so to speak, the second drive. In the present embodiment, the fifth wheel 13 always, ie assigned for each of the measuring intervals, the axis of rotation of the gear as a fixed reference point. For more complex components, it is also possible to assign the turntable 13 for one or more measuring intervals different reference points, which are known in terms of their location, in particular to each other. The fifth wheel 13 is then converted between two measuring intervals.

10 gear

11 measuring arm

12 drive unit

13 turntable

14 telescopic arm

15 telescopic outer tube

16 telescopic inner tube

17 frame

18 base plate

19 side members

20 side members

21 crossbar

22 drive

23 sleds

24 sleds

25 sleds

26 sleigh bed

27 sleigh bed

28 sled bed

29 drive means

30 coupling arm

31 coupling element

32 coupling arm

33 coupling element

34 probe

35 roll Ňegenrolle

Claims

claims

1. Measuring device for measuring large components (10) with a measuring unit and a drive unit (12) for actuating the measuring unit, characterized in that the measuring unit has a passive measuring arm (11), which has a fixed reference point relative to the component (10) ( 13), and that the drive unit (12) on the component (10) can be implemented and fixed, and a first drive (22) for the measuring arm (11), which is coupled to the measuring arm (11), and a second drive ( 35), with which the drive unit (12) is movable on the component.

2. Measuring device according to claim 1, characterized in that on the measuring arm (11) a probe element (probe 34) is arranged, which is held by the measuring arm (11) three-dimensionally movable.

3. Measuring device according to claim 2, characterized in that the

Measuring arm (11) has a rotatable about a first axis turntable (13) on which a telescopic arm (14) about a second, in particular perpendicular to the first axis axis is pivotally mounted, which carries at its free end the probe element (probe 34).

4. Measuring device according to claim 3, characterized in that the

Telescopic arm (14) at least one telescopic outer tube (15), in which a telescopic inner tube (16) is retractable and guided, and that at least one of the tubes (15) is pivotally mounted on the turntable (13) and the another tube (16) carrying the probe element (probe 34).

5. Measuring device according to one of claims 1 to 4, characterized in that on the measuring arm (11) position sensors for detecting the position of the probe element (probe 34) are provided with respect to the reference point (13).

6. Measuring device according to one of claims 1 to 5, characterized in that the drive unit (12) has a first drive (22), by means of which the feeler element (probe 34) is three-dimensionally movable driven.

7. Measuring device according to claim 6, characterized in that the drive (22) has three each movable at a certain angle to each other carriages (23, 24, 25).

8. Measuring device according to claim 7, characterized in that the first Carriage (23) in a first direction (y-direction) is movable, the second carriage (24) in a second direction (x-direction) on the first carriage (23) and the third carriage (25) in a third direction (z Direction) is movably mounted on the second carriage (24).

9. Measuring device according to claim 7 or 8, characterized in that the predetermined angle is a right angle (90 °).

10. Measuring device according to one of claims 6 to 9, characterized in that the drive unit (12) has a frame (17) which is movable on the component (10) attachable.

11. Measuring device according to claim 10, characterized in that the

Frame (17) has the second drive (35) for moving the drive unit (12) on the component (10).

12. Measuring device according to claim 11, characterized in that the

Frame (17) has at least one motor-driven roller (35).

13. A method for measuring large components (10) with a measuring device according to one of claims 1 to 12, characterized in that the component (10) is measured in two or more measuring intervals by the drive unit (12) on the component (12) for each measuring interval. 10) is positioned and fixed, which is coupled to the drive unit (12) coupled to the measuring arm (11) by means of the drive unit (12) and thereby an area of the component (10) is measured.

14. The method according to claim 13, characterized in that two or more fixed reference points (13) on the component (10) are provided, the position, in particular to each other, is known and the measuring arm (11) between two successive of the measuring intervals is implemented.

15. The method according to claim 14, characterized in that during one of the measuring intervals, the position of one or more of the reference points to the currently active reference point is determined.