SU68580A1 - Instrument for checking the distance from the axis of the hole to the base surface - Google Patents

Description

When inspecting manufactured parts, it is necessary to accurately measure the distance between the axes of two holes or between the axis of one hole and the base surface of the part.

When using a conventional measuring tool, obtaining accurate measurement results is difficult, ie the presence of tolerances on the diameters of the holes.

The peculiarity of the proposed device is the use of two parallel levers that carry measuring tips and are placed on a slider perpendicular to the axis of the hole ;; One of the levers is made around one end to act on the indicator measuring pin, resting against the middle of the lever in order for the indicator to show only the deviation of the dimensions of the tested distance irrespective of the deviations of the diameter of the aperture poi-Mtpa.

FIG. 1 ii 2 are shown schematically dia; n; office: nta issue.

the instrument intended to change the distance from the axis of the hole to the baseline, and the second to measure the distance between the axes of the two holes.

The device shown in FIG. 1, is a system of levers /, 2 and 3 pivotally fixed on axis 5. The levers / and 2 are rigidly fastened to each other, and the lever 3 is hinged to the levers 7 and 2 by axis b and is parallel to the lever /. The levers Y and 3 are provided with measuring tips, which, when inserting the levers into the hole of the part to be measured, touch its walls at two diametrically located points O, Oj. The displacement of the lever 3 is measured by the indicator 4, the tip of which touches the lever 3 at its midpoint 8. The rotation of the entire system of levers around the axis 5 can be replaced by its vertical movement in the guides.

The lower arm 7, either due to its weight or under the action of a spring, presses its tip against the wall of the opening at the point O.

405

 3 rotates the axis 6 and with its tip, as indicated above, it touches the hole wall at point 0.

Having installed the indicator on jiyjib, they will measure the details. In case the hole diameter is constant, and only the distance H from the hole axis to the base — the edge of the part —and the value AH, the distance O-0 between the tip of the device does not change, and therefore the position of the lever 3 relative to the lever / will remain unchanged. But since the value of H can vary, then it is entirely; the system of levers, due to the presence of either a slider or axis 5, is moved by the quantities} AH. The indicator / marks the true value of the axis of the hole in the part to be measured.

If the position of the hole in the part remains unchanged, and the diameter of the hole D changes, the O, O points will be shifted in opposite directions by the values - - - The position point of the axis b

will also shift by -;

the point where the indicator touches the lever 3 remains unchanged, and, consequently, the indicator does not fix the change in the diameter D of the hole. A similar picture will take place with a simultaneous change in H and D, since indicator 4 will only record changes in the value of //.

FIG. Figure 2 shows a diagram of an instrument for measuring the distance between the axes of two holes. Accordingly, with the requirements of operation, the device is equipped with four parallel levers 77, 72, 7J and / 4 with measuring tips. Of these, the levers 77 and 72, as in the first case, are interconnected ngarnirno axis J8 and fixed on the third lever 75, which can rotate on a fixed axis 76. These levers (7 /, / 2) serve to fix the position of one hole . To fix the position of the second hole, use the levers / 3 and 74, one of which / 4 is fixed underneath406

The second one (7J) can rotate on the fixed axis 77 and simultaneously serves to fix the indicator 4 on it.

Measurement part 70 is resting on the fixed plate of the instrument. The device is tuned to the reference part and the indicator W / is reset to zero. If the diameters of both holes are unchanged, and only the distance L between their axes changes, then under the action of springs 79 and 20, the measuring tips of the device touch the walls of the holes in the product and take one definite position, which is fixed by the indicator. Since the diameters of the holes are unchanged, the lever / J carrying the indicator will not change its position. If the axis of the second hole is shifted by the value of AL, then due to the invariance of the diameter of the second hole, the lever 72 will not change its position relative to the lever 77, but due to either the slider or lever / 8 the system will move to the left by AL under the action of spring / 9. Since the stop 27 of the indicator is fixed on the lever 72, the Indicator will show a displacement of AL. The indicator and its stop are mounted at the midpoints of the levers 72 and 73. In cases where the distance between the centers of the hole remains unchanged and the diameters of the holes D and D. change by AD and / JDj, then if the right hole is increased by AD. , the measuring tip of the lever 73 will shift to ADi, and the indicator, due to the fact that it is fixed in the middle of the lever 73

move to „-. The lever 77, in turn, will shift to the left by an amount, while the support of the lever 72 will shift by an amount / tDi D, 22

The tips {of the indicator, reinforced at the midpoint of the lever 72, will receive a displacement equal to half the sum of the movements of the ends of the levers 72 and 73-,

equal to

ADi .Ar.,. /), LOZ

2 2 --2 2 ADi also in the direction of movement of the indicator itself. Therefore, the resulting mutual displacement of the tip and the indicator of the indicator will be zero. Thus, despite the various movements of the measuring tips, caused by changes in the diameters of the holes themselves, but with a constant distance between their axes, the indicator arrow will not give a deviation. The readings of the latter will depend solely on the distance between the axes of the holes, excluding the effect of the tolerances on the diameters of the holes. If, in the presence of through holes, it is desirable to check the skew of their axes, then the measuring tips of the device should be installed as close to the edge as possible, and made measurements twice, turning the product over. The difference in the indicator readings gives the amount of skew of the axes at a given distance. If the measured holes are blind, then two devices are needed, in which the measuring tips are located at different heights. Both instruments must be set to one standard.

FIG. 1 1 of the invention 1. Device for checking the distance from the axis of the hole to the base surface, characterized by the use of carrying measuring tips and placed on a slider, moving perpendicular to the axis of the hole, two parallel levers / and J, from which the lever 3 is made rotatable around one of its end, to act on the measuring pin of the indicator, abutting against the middle of the lever so that the indicator shows only deviations from the size of the distance to be checked regardless of deviations of the diameter size tversti. 2. The device changes according to claim 1 when using it to check the distance between the axes of two holes, characterized by the use of four measuring levers that carry the measuring tips of four parallel levers, of which two middle ones are conjugated in the middle with the indicator, turnable around their ends with the placement of one of them together with one extreme lever on the slider and the installation of the second with the second extreme lever motionless.

FIG. 2