DD219562A5 - METHOD AND DEVICE FOR MEASURING A TOOTH PROFILE - Google Patents

Abstract

The invention relates to a method and a device for measuring a tooth profile, wherein a probe 5 scans the tooth profile during a measuring process. In this case, the engagement line E as a geometric location of all touch points of probe 5 and tooth profile is a non-linear curve. Fig. 1

Description

Method and device for measuring a tooth profile. , , - Field of application of the invention

The invention relates to a method and a device for measuring a tooth profile, wherein a probe scans the rotating tooth profile during a measuring operation.

Characteristic of the known technical solutions'

As the state of the art in this case already the linear displacement of a probe from Fußkreis to the tip circle of a gear to be tested is known. The disadvantage here are the long ways and the necessary long slide guides.

The prior art also includes a tooth profile measuring device in which a slide executes two translational movements ₍ the gear wheel to be tested being fixed, resulting in the disadvantage of a corresponding conversion.) In the measuring method with cross slide-guided probe movement, it is not possible to obtain the correct measured value due to the system to capture, but this approximate only by a corresponding conversion.

Object of the invention

The aim of the invention is to avoid the aforementioned disadvantages

Explanation of the essence of the invention

Object of the present invention is to provide a method and an apparatus of the type mentioned, in which the most accurate measurement in a simple manner is feasible.

This object is achieved in that the engagement line is a non-linear curve as a geometric location of all points of contact of the probe and tooth profile. In this case, a probe is used, which is arranged on a carriage; this carriage couples two movements of the measuring head, d. H. of the probe, namely rotation and translation. This advantageously results in that a very accurate measurement of tooth profiles is feasible. Furthermore, the carriage guides may be formed much shorter due to the combination of rotation and translation. The measuring principle with non-linear engagement line can therefore be implemented particularly advantageously via a compact precision mechanism.

The mounted in a measuring head probe is always performed on the carriage normal to the theoretical tooth profile. The probe is guided on the carriage with changing radius with respect to the angle of rotation to the Drehpol the meter. The measuring head is arranged with the carriage on a mounted in the machine frame, height-adjustable slide and has an angle sensor and a position measuring system, which are connected to a control and evaluation unit. The angle of rotation of the rotatably mounted table can be detected via an angle measuring system connected to the control and evaluation unit. ·

embodiment

The invention will be described in more detail with reference to an embodiment shown in the drawing. In the drawing show:

1 shows a non-linear engagement line E with respect to a tooth profile to be measured, FIG. 2 shows a schematic perspective view of a tooth profile measuring device and FIG

3: a measuring head K of the Zahnprofilmeßgerätes. .,

In Fig. 1, the engagement line E is shown, which scans the probe 5 when checking the rotating tooth profile. The method according to the invention is explained below using the example of an involute toothing. According to Fig. 1, the

Nonlinear engagement line E with respect to the Drehporz the measuring device by the polar coordinates r ₂ and cp ₂ defined.

Relative to the pole Z _{2 of} the tooth profile, it is the coordinates φ _Ί and T ₁ and the theoretical involute function.

1, it can be seen that the normal to the involute at any point of the line of action affects the base circle r _b : The probe is thus always performed normal to the theoretical tooth profile.

The functional relationship between the rotation angle Cp ₁ and cp ₂ can be represented as follows:

180 a

_ _ ^ __ .-. sip ^ ₂ -

π r _b

The distance r ₂ from the rotary pole Z to the instantaneous contact point on the involute is:

Γ ₂ (φ ₂ ) = a cos <^ ₂ -r _b ^(2>

with: a = distance of the two rotation poles,

Z and Z ₂ (center distance),

r _b = base circle radius

Cp ₁ = angle of rotation of the polar coordinate r,. ,

or the test object

Cp ₂ = angle of rotation of the polar coordinate r ₂ ,

or the measuring device A. ·;. ..

A practical embodiment of the aforementioned'Meßverfahren shows Fig.2. The measuring head K shown enlarged in Figure 4 is placed on a movable carriage in the Z direction S ₁ . As a result, any desired frontal sectional planes of a toothed wheel P to be tested, in the present case an involute toothed wheel, can be approached. '

As is apparent from Fig. 2 and Fig. 3, the measuring head K consists essentially of a pivotally mounted about the Z-axis carriage S ₃ , and the two measuring systems 1 a and 3 for determining the position coordinates r ₂ and cp _{2 of} the probe 5. To accommodate the gear P is the about the Z ₂ axis rotatably mounted table T. His rotation angle φι is detected by the angle measuring 4. The axis distance can be set according to the gear diameter via the workpiece carriage S _{2 which} can be positioned in the Y direction. '

The current center distance is detected via the measuring system 1 b. · <. .

Before each measuring operation, the two axes Z ₁ and Z _{2 are} aligned spatially parallel via measuring and actuators. The degrees of freedom necessary for this are marked F ₁ ... F ₃ . The same parallelism requirements apply to the two axes Z and Z ₁ . '

To set up the measuring head K, the zero position of the angle of rotation φ-, to determine. It is defined by the theoretical connecting line between the axes of rotation, Z and Z ₂ . The measurement of right and left flank runs symmetrically to this line, with only the signs for the rotation angle reversed.

To prepare the profile measurement, the coordinates of the starting position of the measuring head K must first be calculated in accordance with the following formula set:

φ ₂ start = ^{arc sin}

(3)

r ₂ start = a · cos cp ₂ start - r _b ,. · (4)

with: r _f = involute base circle radius

(or desired radius on the workpiece at the beginning of the involute measurement) ι

a = center distance

r _b = base circle radius

The calculated starting coordinates are given to the bearing control loop of the measuring head K as setpoints. Via the servo-electrically controlled drives of the measuring head K, the measuring probe 5 is then positioned corresponding to the theoretical engagement line E. It is assumed that the probe 5 is in a tooth gap and does not collide with the tooth flank. Subsequently, the gear P is rotated about its axis of rotation Z ₂ against the probe until contact takes place, and the starting angle cp _{1Start of} the workpiece defines:

180 a '. ^: · "'- ^:. "Τ'.'/'

¥> lStart = "7Γ" - · ^sm ^ 2 Start ~ Ψι Start. ;,

In the actual measuring process, the gear rotates continuously about the table axis Z ₂ , wherein the measuring head K and the probe 5 according to the relationships (1) and, (2) is tracked.

Deviations from the theoretical involute are in this case detected by the measuring probe 5 and can be output as usual in the form of a so-called involute diagram.

A limiting case of the presented measuring method is in the measurement of rack profiles. Here the otherwise non-linear line of action becomes a straight line and is identical to the tooth profile.

The measuring structure shown in Fig. 2 can also be used for Flankeniinienmessungen without restrictions.

As can be seen from FIG. 2, the position numbers 1 b represent the infeed movement and 1 a the measuring movement with respect to the position measuring system Y. The position number 2 relates to the position measuring system Z, the position number 3 to the angle transmitter of the measuring head K, the position number 4 to the angle transmitter of the workpiece P. Here, the angle encoders 3 and 4 and the aforementioned distance measuring systems via the control and evaluation unit 6 are connected to each other, the entire measurement process is triggered by the Winkeigeber 4. In each case, the probe 5 passes through an engagement line E, which is executed according to FIG. T as a non-linear curve. This results in a simple way, a significant improvement in the accuracy of a tooth profile.

Claims (6)

Invention claims: 1. A method for measuring a tooth profile, wherein a probe during a measuring operation scans the rotating tooth profile, characterized in that the engagement line (E) as a geometric location all points of contact probe (5) and tooth profile is a non-linear curve, 2. Zahnprofilmeßgerät for carrying out the method according to item 1, wherein deKMeßtaster performed on a carriage and the gear to be tested is arranged on a rotatably mounted table, characterized in that in a measuring head (K) mounted probe (5) on the carriage ( S ₃ ) is always performed normal to the theoretical tooth profile. 3. Zahnprofilmeßgerät according to item 2, characterized in that the probe (5) on the carriage (S ₃ ) with (changing radius (r ₂ ) with respect to the rotation angle (φ ₂ ) is guided to the rotating pole (Z) of the measuring device. 4. Zahnprofilmeßgerät according to the points 2 and 3, characterized in that the measuring head (K) with the carriage (S ₃ ). a mounted in the machine frame, height-adjustable carriage (S ₁ ) is arranged. 5. Zahnprofilmeßgerät according to the points 2 and 4, characterized in that the measuring head (K) an angle sensor (5) and a position measuring system (1 a), which are connected to a control and evaluation unit (6). 6. Zahnprofilmeßgerät according to item 5, characterized in that the angle of rotation ((Cp ₁ ) of the rotatably mounted table (T) via a with the control and evaluation unit (6) connected to Winkelmeßsystem (4) can be detected. For this 3 pages drawings