JPH05126503A - Method for measuring dimensions of thin ring - Google Patents

Abstract

PURPOSE:To measure accurately and easily the inside diameter of a thin ring, this measurement method being applicable to the measurement of the ball race of a thin ball bearing and the shell ball race of a roller bearing. CONSTITUTION:A measurement tool 1 which has a circular hole 1 where a ring 2 to be measured is engaged and is divided into a plurality of split parts 1a and 1b. By surrounding and clamping the ring 2 with these split parts 1a and 1b, the outer shape of the ring 2 is constrained, thus correcting the roundness. In this state, the inside diameter of the ring 2 is measured by an inside- diameter measuring equipment 3 such as a dial gauge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimension measuring method generally applied to, for example, an outer ring of a thin ball bearing, a shell outer ring of a roller bearing, and other thin rings.

[0002]

2. Description of the Related Art Conventionally, in the case of measuring the inner diameter of a ring-shaped object, a method of using a dial gauge or a rod-shaped micrometer to press the two points on the inner diameter surface of the ring to be measured is generally adopted. .

[0003]

However, in the case of a thin-walled ring, there is a problem that the ring to be measured is deformed by the measuring force and the correct dimension cannot be measured. In addition, many thin rings do not have good roundness, and it is difficult to measure the dimensions correctly.

For example, in recent years, ultra-thin ball bearings having a smaller radial thickness than the inner diameter have been produced. The outer ring used in such bearings is a thin ring, and therefore the inner diameter surface is measured. In this case, the problem of deformation due to the measuring force arises. Further, the shell-shaped outer ring of the roller bearing often consists of a press-molded product of a thin metal plate, so that the circularity cannot be maintained by itself. These bearing outer rings form a perfect circle having a predetermined inner diameter when they are press-fitted into the bearing box, but the inner diameter cannot be measured while they are press-fitted into the bearing box during the production process. Therefore, it is difficult to perform accurate dimension measurement. On the other hand, for these bearing outer rings, it is strictly required to keep the radial clearance during use within the specifications, and it is essential to measure the raceway groove.

An object of the present invention is to provide a dimension measuring method for a thin-walled ring, which enables accurate and easy measurement of the inner diameter.

[0006]

The dimension measuring method of the present invention is a method of measuring using a measuring jig having a circular hole into which a ring to be measured fits. The measuring jig is divided into a plurality of split molds. By enclosing the ring to be measured with these split molds and fitting the split molds, the ring to be measured is fitted into the circular hole, and the inner diameter of the ring to be measured is measured by the inner diameter measuring instrument in this fitted state.

[0007]

According to this method, the circularity of the ring to be measured is corrected by aligning the split mold of the measuring jig and restraining the outer diameter of the ring to be measured, and the inner diameter can be measured in the corrected state. it can. Further, the ring to be measured is prevented from being deformed by the measuring force. Therefore, the inner diameter of the thin ring can be accurately measured.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. This dimension measuring method is a method in which the inner diameter of the thin measured ring 2 is measured by the inner diameter measuring device 3 using the measuring jig 1. The ring 2 to be measured is, for example, an outer ring of a thin ball bearing or a shell type outer ring of a roller bearing. The measuring jig 1 is composed of two split dies 1a and 1b divided by a dividing surface 1c along the axial direction, and has an inner diameter set to a predetermined fitting dimension with respect to a reference value of the outer diameter of the ring 2 to be measured. A circular hole 4 is formed. The measuring jig 1 includes two split molds 1.
An engaging portion (not shown) for positioning a and 1b along the dividing surface 1c so as not to shift from each other, and a clamp means (not shown) such as a bolt for tightening in a fitted state are provided. Instead of providing the clamp means in the jig 1, the jig 1
It may be provided on a table or the like on which is mounted. As the inner diameter measuring device 3, a dial gauge or a rod-shaped inner micrometer is used.

At the time of measurement, the ring to be measured 2 is sandwiched by split molds 1a and 1b from both sides and fitted into the inner diameter hole 4, and both split molds 1a and 1b are tightened together. In this fitted state, the inner diameter of the ring to be measured 2 is measured by the inner diameter measuring device 3.
When the measured ring 2 is the outer ring of the ball bearing, the inner diameter of the raceway groove formed on the inner diameter surface of the ring is measured.

According to this dimension measuring method,
Since the split molds 1a and 1b are tightened together, the outer diameter of the ring to be measured 2 is constrained and the circularity of the ring to be measured 2 is corrected. Further, the deformation of the ring to be measured 2 due to the measuring force is prevented. Therefore, the inner diameter measurement device 3 can accurately measure the inner diameter. Therefore, this dimension measuring method can be preferably applied to a thin ball bearing or the like having a radial thickness that is smaller than the inner diameter of the inner ring. Further, since the split jig type is used as the measuring jig 1, even if the thin ring 2 has a poor roundness, the attachment / detachment to / from the circular hole 4 and the above correction can be easily performed.
The whole measurement work is simplified.

The ring 2 to be measured returns to its original shape when it is removed from the measuring jig 1, but when the ring 2 to be measured is a bearing outer ring, if the roundness and dimensions of the bearing box can be controlled,
When it is installed in the bearing box, it becomes round again. Therefore, even if the above-mentioned measuring method is adopted, the radial gap when the bearing is used can be kept within the standard.

Although the measuring jig 1 is divided into two in the above embodiment, it may be divided into three or more. Further, although the inner diameter measuring device 3 is a hand-held measuring device in the above embodiment, an automatic inner diameter measuring device in which the jig 1 and the inner diameter measuring device 3 are combined may be used. Further, the method of the present invention can be applied to a ring having a short axial length to a cylindrical ring having a long axial length.

[0013]

EFFECTS OF THE INVENTION The thin ring size measuring method of the present invention is a method of measuring a ring to be measured by using a measuring jig made of split dies and enclosing the ring to be measured by aligning these split dies. The circularity can be corrected by restraining the outer diameter, and the inner diameter can be measured in the corrected state. In addition, the measured ring is prevented from being deformed by the measuring force. Therefore, the inner diameter of the thin ring can be accurately measured. Further, since the split jig is used as the measuring jig, even if the ring is a thin ring having no roundness, the circular hole can be easily attached / detached and the above correction can be performed, and the whole measurement work can be simplified.

[Brief description of drawings]

FIG. 1 is a cutaway plan view showing an embodiment of the present invention.

FIG. 2 is a plan view showing the ring to be measured.

[Explanation of symbols]

1 ... Measuring jig, 1a, 1b ... Split mold, 2 ... Ring to be measured,
3 ... Inner diameter measuring device, 4 ... Circular hole

Claims (1)

[Claims] 1. A process of preparing a measuring jig having a circular hole into which a thin ring to be measured is fitted and divided into a plurality of split molds, and the split molds are surrounded by surrounding the ring to be measured. Therefore, the dimensions of the thin-walled ring including the step of fitting the ring to be measured into the circular hole of the measuring jig, and the step of measuring the inner diameter of the ring to be measured fitted to the measuring jig with an inner diameter measuring instrument. Measuring method.