SU759835A1 - Apparatus for measuring cone thread pitch - Google Patents

Description

The invention relates to a measurement technique and can be used to measure tapered threads on pipes and couplings, preferably of a non-oil gauge.

A device for measuring the pitch of tapered threads is known.

When installing a known device on a controlled thread, the measuring tip moves non-parallel to the cylinder or., · „With a threaded cone.

In the case of control of tapered threads, the magnitude of this non-parallelism varies depending on the diameter of 25 and the associated angle of lifting of the thread. This circumstance causes an additional error in the control of similar threads of different diameters, which manifests itself in 30

; ² ''

even when checking different sections of the same tapered thread.

To eliminate the additional error, it is necessary to make adjustments when switching from monitoring one thread diameter to another, which is associated with time expenditures and a decrease in labor productivity.

The aim of the invention is to improve the performance of the control. "

This goal is achieved by the fact that in the device the second base tip is located in a plane perpendicular to the direction of movement of the measuring tip and passing through the first base tip at a distance depending on the parameters of the monitored thread. 7 '· ..

Such a device can improve the performance of the control by reducing the loss of time for its reconfiguration.

FIG. 1 shows the proposed device, a general view; in FIG. 2, a view of the device from the tips.

, 7 The device includes a housing 1, a movable rod 2c measuring on • 3

tip 3, indicator 4, carriage

5 with two basic tips

6 and 7. The basic tip 6 is aligned with the direction of movement of the measuring tip 3. The basic tip 7 is located in a plane perpendicular to the direction of movement of the measuring tip

and passing through the base tip> nick 6 at a distance B from the last.

The distance B is obtained from the joint solution of the equations of the conical spiral of the thread of the thread and the plane perpendicular to the generator of the cone and intersecting the spiral at the points of location of the basic tips b and 7

759835

where P is the thread pitch)

K - thread taper / d - radius vector of the thread at the point

Placement of the base tip b.

Θ - the angle of rotation between the points of placement of the basic tips b and 7.

The angle Θ, from the condition of the location of the points of placement of the tips 6 and 7 in the plane perpendicular to the measurement line, and, simultaneously, on the conical spiral, is the root of the equation

Κξ (4-θθ5θ) -θ ^ (4 + ^ * θ> 0

Having solved equation (2) relative to © and substituting its value in (1), we find B.

The value of B is very weakly dependent on the diameter of the thread. This allows you to use one value B for the standard range of the thread diameter of each type.

The distances B between the base tips, calculated according to equations (1) and (2), are given in the table (parameters are given in mm).

TO R Standard range diameters B four 2 · 3 four 1: 4 5.08 45 - 140 13.2 1: 4 6.35 126 - 148 sixteen 1: 6 6.35 87 - 190 25 1:16 2.54 33, - 85 27 1:16 3.175 60 - 500 32.

Continuation tab. ' four ΣΞΊΞΞ ι ³ ι four 1:16 5.08 114 - 340 53, 1:12 4.232 60 - 114 33 1:12 5.08 114 - 245 39

The use of such a device allows the measurement of tapered threads of different diameters with a single setting, while the measurement error does not exceed 1 μm and can be neglected.

During operation, the base lugs b and 7 of the device are placed in the hollow of the thread and hold the body 1 in the measurement position. The direction of movement of the measuring tip 3 at the same time practically coincides with the generatrix of the thread, on which the base tip 6 is placed.

The measuring tip 3 is installed in another depression of the measured thread section and gives the rod 2 a definite position relative to the indicator 4.

Indicator 4 counts the deviation of the pitch of the measured thread from the pitch of the exemplary thread used when setting up the device.

Comparative tests of the proposed device with known ones have shown that the control performance increases 3–4 times by reducing the number of device reconfigurations required.

Claims (1)

Claim A device for measuring the pitch of tapered threads; improve the performance of the control, the second base tip is located in a plane perpendicular to the direction of movement of the measuring tip and passing through the first baseline echnik at a distance that depends on the parameters of the controlled thread.