RU2214324C2 - Method for measuring deviation from mutual normality of guides of metal cutting machine tools - Google Patents

Abstract

FIELD: machine tool manufacture, assembling and exploitation of machine tools. SUBSTANCE: method is realized at using angle, indicator strut and measuring head. In order to enhance accuracy and comfortability of measuring operation, angle has two sides formed by basic and testing liners with symmetry axis along testing liner. Method comprises steps of forcing angle along its one side to lower guide; moving indicator strut from one terminal position of upper guide to other terminal position at touching measuring head and second side of angle; receiving difference of readings of head in both terminal positions; then turning angle by 180 degrees and repeating measuring process; determining deviation from mutual normality as arithmetic mean value of readings of measuring head in both positions of angle. EFFECT: enhanced accuracy of measurement. 4 dwg

Description

 The invention relates to machine tool and can be used to control the mutual perpendicularity of the guides. Most machines have two or three mutually perpendicular guides. During the assembly and operation of machines it is necessary to control the accuracy of their relative position.

 A known method of measuring deviations from the perpendicularity of two planes using a measuring head and a square [I.M. Belkin. Tolerances and landings (basic norms of interchangeability): - M .: Engineering, 1992 - p. 257]. "A square of one of its sides is pressed to the controlled surface of the product located on the calibration plate. A stand with a measuring head (position 1) is brought to the other side of the square, which is set to zero. Then the stand with the head is moved to position 2 and the head reading is counted . For the deviation from perpendicularity take the difference of the readings of the measuring head in positions 1 and 2 ".

 The described method is generally accepted for the inspection of flat surfaces, including the control of guide machines. In this case, the square of one of the sides is pressed against the lower guide, the indicator stand is moved from one extreme position of the upper guide to the other extreme position, the measuring head touches the second side of the square, the difference in its readings in both extreme positions is counted.

 The method has several significant disadvantages.

 Deviations from the perpendicularity of the sides of the square are automatically included in the measurement error. Therefore, for accurate measurements, squares of very high accuracy are required. Based on the fact that the error of the measuring device should not exceed a quarter of the tolerance of the controlled parameter, it becomes clear that in order to control the mutual perpendicularity of the guiding metal-cutting machines, the tolerance of which is thousandths of a millimeter, ultra-precise working squares are required. The manufacture of such squares is very time-consuming.

 It is possible to identify the perpendicularity of the sides of the working squares by comparing them with the standard squares, the accuracy of which should be several times higher than the accuracy of working squares. Accordingly, the costs of manufacturing reference squares increase.

 To achieve the initial accuracy of the squares and maintain it during operation, it is necessary to provide increased rigidity of their design, and this, in turn, necessitates making squares massive. Heavy squares have to be transported and installed for control on machines using additional hoisting and transporting devices. Shocks are likely that do not help maintain the original accuracy. There are also inconveniences and difficulties in the work, since it is often necessary to manually move the squares to perform control on different sections of the guides.

 The technical result of the invention is aimed at improving the convenience and accuracy of control while reducing the accuracy requirements of measuring instruments.

The technical result is achieved in that the control is carried out using a light and relatively inaccurate double-sided square, consisting of a base and a control ruler, with an axis of symmetry along the control ruler, which is pressed with the base side to the lower guide, move the indicator stand from one extreme position of the upper guide to another extreme position, the measuring head of the indicator stand touches the control side of the square, count the difference in the readings of the head in both extreme positions s. Measurements are performed twice in two positions of the square, to perform the second measurement, the square is turned 180 ^o around the axis of symmetry, and deviations from the perpendicularity of the guides are calculated as the arithmetic average of the difference in the readings of the indicator head in both positions of the square.

An essential feature of the invention is that the measurements are performed twice in two positions of a two-sided square, consisting of a base and a control ruler, with an axis of symmetry along the control ruler, around this axis the square to turn the second measurement is turned 180 ^o , and deviations from the perpendicularity of the guides are calculated as arithmetic mean of the difference in the readings of the indicator head in both positions of the square.

The invention consists in the following. A special square is laid on the guides of the machines, which differs in design from the traditional one. It consists of two flat, bonded to each other nominally (but not necessarily accurately) mutually perpendicular rulers, one of which is basic, and the second is a control. The axis of symmetry of the control line is the axis of symmetry of the entire square. Around this axis of symmetry, the square can be turned 180 ^o and carry out control in each of its two positions.

 In FIG. 1 shows the placement of the square in the first position on the lower guide of the machine.

 Figure 2 shows how to check in the first position of the square.

 Figure 3 shows the placement of the indicator rack on the upper guide of the machine.

 Figure 4 shows two projections of the placement of the square in the second position after its revolution.

The base line 1 has a base plane, which can be divided into two working sections: A and A ', one of the sections (in figure 1, section A), the square is pressed against the lower guide 2 of the machine. To side B of the control line 3 (FIG. 2), an indicator stand 4 with a measuring head 5 is brought down (FIG. 3), which is set at point B ₁ to zero. The indicator rack with the measuring head is moved along the upper guide 6 to point B ₂ (Fig. 2) and the reading of the measuring head is counted. Fix the first difference in the readings of the measuring head at points B ₁ and B ₂ .

The square is turned around the axis of symmetry (Fig. 4), pressed against the lower guide 2 by the working section A ′ of the basic ruler 1, and the control procedure described above is carried out, in which the second difference in the readings of the measuring head is fixed at points B ′ ₁ and B ′ ₂ .

 The actual deviation from the perpendicularity of the guides is equal to the arithmetic mean of both differences in the readings of the measuring head obtained in the measurements before and after the flip of the square.

 The described measurement method allows to exclude the most significant error of the square, namely the non-perpendicularity of the relative position of the base and control rulers of the square. This exception automatically occurs when summing the differences in the readings of the measuring head. Consequently, the requirement for the exact perpendicularity of the sides of the square disappears. It is replaced by another, easily achievable technical requirement of mutual parallelism of both working sides of the control line of the square. In this regard, there is no difficulty not only in the manufacture of a means of control, but also to maintain the accuracy of the proposed square during operation. The square may be relatively not rigid, not heavy, convenient to use.

 Consider 3 examples of monitoring the proposed method of guides, the mutual non-perpendicularity of which is equal to 0.035 mm

1. If the base and control sides of the square are absolutely perpendicular to each other, then in the first (at points B ₁ and B ₃ ) and in the second positions of the square (at points B ' ₁ and B' ₂ ) the difference in the readings of the indicator head will be + 0.035 mm (the sign may be opposite if the guides are rejected in the other direction). The arithmetic mean of both measurements is also equal to +0.035.

2. Suppose a square has a non-perpendicularity of the sides of the rulers +0.03 mm (less than a controlled non-perpendicularity). In the first measurement, the difference in the readings of the measuring head at points B ₁ and B ₂ will be +0.005 mm, after the flip of the square during the second measurement at points B ' ₁ and B' ₂ will be +0.065 mm. The arithmetic average of two measurements [(+0.005) + (+ 0.065)] / 2 = +0.035 mm.

3. Suppose a square has a non-perpendicularity of the sides of the rulers +0.05 mm (more than a controlled non-perpendicularity). In the first measurement, the difference in the readings of the measuring head at points B ₁ and B ₂ will be -0.015 mm, after the flip of the square during the second measurement at points B ' ₁ and B' ₂ will be +0.085 mm. The arithmetic average of two measurements [(-0.015) + (+ 0.085)] / 2 = + 0.035 mm.

 As we have seen, the non-perpendicularity of the sides of the square does not affect the results of the control.

Claims (1)

A method of measuring deviations from the mutual perpendicularity of the guiding metal cutting machines using a square, indicator stand and measuring head, including the use of a square made of two-sided of the base and control rulers with the axis of symmetry along the control ruler, while one of the sides squeezes the square to the lower guide, move the indicator a rack from one extreme position of the upper guide to another extreme position when touching the measuring head and the second side of the square the difference between the readings of the head in both extreme positions is measured, then the square is rotated 180 ^° and the measurements are repeated, and the measured deviation from the mutual perpendicularity is determined as the arithmetic mean of the difference in the readings of the measuring head in both positions of the square.

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