Design of special measuring tools for deep hole machining (2)

October 23, 2022

2. Hole depth measurement special measuring tool

The bottom of the workpiece shown in Figure 1 needs to be machined to ensure its dimensional requirements (using a forming knife and milling hole). In the measurement of the hole depth, we started measuring with a large depth gauge, but it has been proved that this not only increases investment, but also affects production efficiency. To solve this problem we designed a deep hole length gauge. As shown in Figure 3.

image 3

1. Measuring head 2. Workpiece 3. Anti-off pin 4. Measuring plate 5. Measuring rod

It consists of a measuring rod 5 and a measuring disc 4. The measuring disc can slide on the measuring rod; during the manufacturing of the measuring tool, after assembling the measuring disc, the measuring disc is moved so that the distance between the measuring surface of the measuring disc B and the measuring head is the size L to be measured, and then the line G is engraved on the plane G (called Zero line), according to the maximum value L+Δ and the minimum value L-Δ of the measured size L±Δ, respectively, the upper line and the lower range line are drawn on the plane of the measuring disc (note: upper range line and lower line) The range line is only engraved on the measuring plate and not on the plane of the measuring rod, while the zero line needs to be penetrated to correct the measuring tool to zero).

When in use (the gauge should be proofed first), the measuring rod is inserted into the workpiece hole to move the measuring disc into contact with the end surface of the workpiece, and the measuring head at the lower end of the measuring rod is in contact with the bottom surface of the inner hole; The relative position of the line is used to determine whether the product is qualified. That is, the measuring rod zero line is between the upper and lower range lines of the measuring disc.

3. Deep hole aperture special measuring tool

In the aperture measurement, it is usually carried out with tools such as an inner diameter gauge, a caliper, a caliper, etc., but when the D dimension is measured in the workpiece shown in Fig. 4, it causes certain difficulties. For this purpose, a special gauge is designed, as shown in Fig. 4 (in the figure) The workpiece shown is shown as another workpiece to be machined with a deep hole, which consists of a measuring rod, a pointing rod, a probe and a positioning disc.

The measuring rod 9 and the indicating rod 8 are connected by a pin 7, which can rotate with each other; the measuring rod 9 and the end of the indicating rod 8 are equipped with a probe, and the two measuring heads are in a straight line on the same plane, according to To size the image, adjust the distance between the two probes to D, and scribe the line (zero line) on the measuring rod according to the position indicated by the indicator rod. Then adjust the distance between the two probes as D+δ and D-δ respectively; mark the range line and the lower range line on the measuring rod according to the position indicated by the indicator rod. The measurement position H is defined by the lower end positioning head of the measuring rod 9.

Gently press the lever handle 5 during use so that the distance between the two probes is smaller than the aperture so that the gauge extends into the inner bore of the workpiece while also preventing wear of the probe. When the positioning head of the equivalent tool is in contact with the bottom surface of the hole, loosen the handle handle and slightly shake the measuring instrument to ensure that the measuring head is in full contact with the inner wall of the hole, and then the product can be judged according to the position of the indicator rod. That is, the indicator rod position is between the upper range line and the lower range line.