JP2010060467A - Circularity measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circularity measuring device capable of measuring the circularities of through-holes formed in inner rings accurately and inexpensively, in the shape of total number inspection on a production line. <P>SOLUTION: The circularity measuring device includes a table 9 on which an inner ring 2 having a through-hole 5 is arranged, a measuring head 6 of an air micrometer which is inserted from above into the through-hole 5 of the inner ring 2 arranged on the table 9, a weight 10 put on the upper surface of the inner ring 2 arranged on the table 9, a vertical drive mechanism 11 for moving the weight 10 up and down, and a rotation drive mechanism 12 for relatively rotating the table 9 and the measuring head 6 on the occasion of measurement. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a roundness measuring apparatus for measuring the roundness of an inner diameter surface of a circular recess provided in a lightweight work such as an inner ring.

  FIG. 4 shows a configuration of a general tapered roller bearing 1. The tapered roller bearing 1 includes an inner ring 2 having an annular shape, a roller member 3 that is rotatably disposed on a raceway surface of the inner ring 2, and a circle in which the inner ring 2 is rotatably fitted via the roller member 3. A main body is formed by the annular outer ring 4.

  A through hole 5 having a circular cross section is provided at the center of the inner ring 2 and the inner diameter of the through hole 5 has been conventionally inspected on the production line of the inner ring 2. For the inner diameter measurement here, for example, an inner diameter measuring device using an air micrometer as described in Patent Document 1 is preferably used. According to this inner diameter measuring apparatus, a measurement head of an air micrometer is inserted into a through hole 5 provided in the inner ring 2 through a slight gap, and air is laterally passed from the nozzle opening of the measurement head at the insertion position. The inner diameter of the through hole is measured by jetting out and detecting the back pressure and the like.

  As described above, in the past, all the inside diameters of the through holes 5 were inspected. However, in terms of quality control, the roundness of the inside diameter surface of the through holes 5 should also be inspected on the production line. Is desirable. However, it has been very difficult to measure roundness in the form of 100% inspection on a production line for a lightweight work 7 that is mass-produced like the inner ring 2.

  The reason why roundness measurement in the form of 100% inspection is difficult is that when the measurement head of an air micrometer is inserted into the through-hole 5 to measure roundness, air is ejected from the measurement head. At the same time, it is necessary to rotate the measuring head relative to the work 7 such as the inner ring 2. At this time, a mechanism and labor for securely fixing the lightweight work 7 to the table one by one are required. There is to be.

This is because there is only a slight gap (for example, 0.03 mm) between the through hole 5 of the workpiece 7 and the measurement head. On the other hand, when the workpiece 7 is light when the measurement head is relatively rotated, the workpiece 7 is easily moved unexpectedly and is not synchronized with the rotation of the table. On the other hand, when a mechanism for fixing the workpieces 7 to the table one by one or labor is required, it is very difficult to measure roundness in the form of 100% inspection on the production line as described above. .
JP 2001-108428 A

  The present invention has been invented in view of the above problems, and the roundness of the inner diameter surface of a circular recess formed in a lightweight work such as an inner ring is accurately measured in the form of 100% inspection on a production line. It is an object of the present invention to provide a roundness measuring apparatus that can measure at low cost.

  In order to solve the above-mentioned problems, the roundness measuring apparatus of the present invention includes a table 9 on which a workpiece 7 having a circular recess 8 to be measured is disposed, and a circular recess 8 of the workpiece 7 disposed on the table 9. A measurement head 6 of an air micrometer inserted from above, a weight part 10 placed on the upper surface of a work 7 arranged on a table 9, a vertical drive mechanism 11 for moving the weight part 10 up and down, and a table at the time of measurement 9 and a rotational drive mechanism 12 for rotating the measuring head 6 relatively.

  In the roundness measuring apparatus having the above-described configuration, even when the workpiece 7 is light, the weight of the weight portion 10 is added to the workpiece 7 during measurement, thereby greatly increasing the frictional resistance with the table 9. Can be increased. Therefore, the roundness of the inner diameter surface of the circular recess 8 provided in the workpiece 7 can be measured quickly and at low cost without requiring a mechanism and labor for fixing the lightweight workpiece 7 to the table 9. It becomes.

  The vertical drive mechanism 11 is preferably a lift mechanism that holds the weight portion 10 above the workpiece 7 before and after measurement, and lowers the weight portion 10 and places it on the upper surface of the workpiece 7 during measurement. is there. By doing in this way, before and after measurement, the weight part 10 can be lifted and shifted to a standby state, and the workpiece 7 on the table 9 can be quickly replaced in this standby state.

  In addition, it is preferable that the rotation drive mechanism 12 rotates only the table 9 side during measurement. By doing so, a mechanism for rotating the table 9 may be provided as a mechanism required for rotation at the time of measurement, and a complicated mechanism for rotating the measurement head 6 is not necessary. Therefore, the roundness measuring device of the present invention can be provided at a lower cost.

  In addition, it is preferable that the upper surface 13 of the table 9 is provided with a large number of fine grooves 14 for releasing the polishing oil adhering to the work 7. By doing in this way, even if polishing oil has adhered to the workpiece 7 in the previous step of the roundness measurement step, the workpiece 7 slides on the table 9 by the oil film when performing the measurement with the weight portion 10 placed thereon. It is prevented. Therefore, the roundness can be measured quickly and accurately on the production line.

  The circular recess 8 into which the measuring head 6 is inserted is preferably a through-hole 5 having a circular cross section formed in the workpiece 7. In this way, when the workpieces 7 are sequentially set at predetermined positions on the table 9, the measuring head 6 is inserted into the through hole 5 of the set workpiece 7 and the weight portion 10 is placed on the workpiece 7. The roundness of the inner diameter surface of the through-hole 5 formed in a circular cross-section can be quickly measured simply by relatively rotating the measurement head 6 while jetting air laterally from the measurement head 6. . Therefore, it is possible to measure the roundness of the inner diameter surface of the through-hole 5 that has been conventionally measured by sampling inspection in the form of 100% inspection on the production line.

  INDUSTRIAL APPLICABILITY The present invention has an effect that the roundness of the inner diameter surface of a circular recess formed in a lightweight work such as an inner ring can be accurately measured at a low cost in the form of 100% inspection on a production line. .

  The present invention will be described based on embodiments shown in the accompanying drawings. 1 and 2 schematically show an example of a roundness measuring apparatus according to an embodiment of the present invention. FIG. 1 shows a measurement state, and FIG. 2 shows a standby state when a workpiece is exchanged.

  The roundness measuring device of this example measures the roundness of the inner diameter surface of the through hole 5 provided in the inner ring 2 constituting the tapered roller bearing 1. This roundness measuring device has a structure in which air is measured laterally from the measuring head 6 while the measuring head 6 and the inner ring 2 are relatively rotated while the measuring head 6 of the air micrometer is inserted into the through hole 5. It is structured to measure the roundness by ejecting.

  In this example, as described above, the inner ring 2 of the tapered roller bearing 1 is the workpiece 7 to be measured, and the roundness of the inner diameter surface of the through hole 5 of the inner ring 2 is measured. It is also possible to measure the roundness of the inner diameter surface other than the through hole 5 of the inner ring 2. In other words, the roundness of the present invention is not limited to the through hole 5 provided in the inner ring 2, as long as it is roundness of the inner diameter surface of the circular concave portion 8 having a circular cross section formed through the workpiece 7. It can be measured using a measuring device.

  The roundness measuring apparatus of the present example includes a table 9 that places the inner ring 2 in a predetermined position so that the opening portion of the through hole 5 faces upward, and a through hole of the inner ring 2 that is arranged on the upper surface 13 of the table 9. 5, a measurement head 6 of an air micrometer inserted from the upper end opening of the through hole 5, a ring-shaped weight portion 10 placed on the upper surface of the inner ring 2 disposed on the upper surface 13 of the table 9, and a weight portion 10 includes a vertical drive mechanism 11 that moves the table 10 up and down, and a rotary drive mechanism 12 that rotationally drives the table 9 when measuring roundness.

  Hereinafter, each configuration will be further described in detail. The table 9 has an upper surface 13 formed horizontally, and a rough knurling process is applied to at least a predetermined portion of the upper surface 13 where the inner ring 2 is disposed. By performing the knurling process, a large number of fine grooves 14 for releasing the polishing oil adhering to the inner ring 2 in the previous step are formed in the upper surface 13 (see FIG. 1B).

  The measuring head 6 has a columnar shape, and a pair of air ejection nozzle ports 16 are opened near the lower end of the outer peripheral surface 15 at positions shifted by 180 degrees in the circumferential direction. An air supply path 17 is formed through the measuring head 6, and an upstream end of the air supply path 17 is connected to an air pump (not shown) of an air micrometer. The air supply path 17 is bifurcated downstream from the branch location provided in the middle of the flow path in opposite directions, and a nozzle port 16 is formed at each branched downstream end. The measurement head 6 is supported by a support mechanism 25 and is reciprocated in the vertical direction within a predetermined range between the measurement position shown in FIG. 1 and the standby position shown in FIG.

  The weight part 10 is a ring-shaped member having a through hole 18 at the center thereof. The inner diameter surface of the through hole 18 is precisely dimensioned so as to be the reference dimension of the inner diameter surface of the through hole 5 of the inner ring 2. Moreover, as shown in FIG. 1, when the weight part 10 is put on the upper surface of the inner ring | wheel 2, the through-hole 5 of the inner ring | wheel 2 and the through-hole 18 of the weight part 10 are provided so that it may communicate in the up-and-down straight line shape. . The measuring head 6 is inserted into the through hole 5 of the inner ring 2 located below through the through hole 18 of the weight part 10 located above. A locking groove 19 that is used when lifting the weight portion 10 is recessed in the lower part of the outer peripheral surface of the weight portion 10 over the entire circumference.

  The vertical drive mechanism 11 includes a lift mechanism 20 that hooks the weight portion 10 and moves the weight portion 10 up and down while maintaining a horizontal posture. The lift mechanism 20 includes a cylindrical lift member 21 having an open lower end that can move up and down, and the weight portion 10 is housed in the lift member 21. From the opening edge of the lower end of the lift member 21, a convex rib-like hook 22 is extended inward, and a locking groove 19 recessed in the weight portion 10 is hooked and locked from below by the hook 22. It has become so.

  At the upper end position of a predetermined range in which the lift member 21 moves up and down (see FIG. 2), the weight portion 10 is supported by the lift member 21 in a state of floating above the inner ring 2. Further, at a lower end position within a predetermined range in which the lift member 21 moves up and down (see FIG. 1), the weight portion 10 is placed on the upper surface of the inner ring 2 and is arranged so as to apply the entire weight of the weight portion 10 to the inner ring 2. Is done.

  In measuring the roundness of the inner diameter surface of the through-hole 5 of the inner ring 2 using the roundness measuring device of this example having the above-described configuration, first, the through-hole 5 is formed at a predetermined position on the upper surface 13 of the table 9. The inner ring 2 is arranged so as to have a posture penetrating in the vertical direction. At this time, the measuring head 6 is kept waiting above the through hole 5. Further, the weight portion 10 is also kept waiting above the inner ring 2 while being hooked and lifted by the lift member 21 (see FIG. 2). In this standby position, the lower end portion of the measurement head 6 is positioned in the through hole 18 of the weight portion 10, and the pair of nozzle ports 16 of the measurement head 6 are positioned so as to face the inner peripheral surface of the through hole 18.

  Next, the measurement head 6 is lowered, and the weight portion 10 is lowered together with the lift member 21 to shift to the measurement state shown in FIG. In this measurement state, the measurement head 6 is inserted into the through hole 5 of the inner ring 2 from the front end side, and the pair of nozzle ports 16 of the measurement head 6 are positioned to face the inner diameter surface of the through hole 5. The weight portion 10 is placed on the upper surface of the inner ring 2 after being separated from the lift member 21.

  After setting in the above measurement state, air is sent from the air pump of the air micrometer into the air supply path 17, and air is ejected from the pair of nozzle ports 16 toward the inner diameter surface of the through hole 5, and the table 9 is It is driven to rotate about the vertical axis A. The vertical axis A, which is the rotation center axis of the table 9, is provided so as to coincide with the center axis of the through hole 5 of the inner ring 2 and coincide with the center axis of the measurement head 6.

  Here, if the measuring head 6 is inserted into the through-hole 5 and the table 9 is rotated while the weight portion 10 is not placed, the lightweight inner ring 2 is unexpectedly moved relative to the table 9 as described above. It moves to. In contrast, by placing the weight portion 10 on the inner ring 2 at the time of measurement as described above, the frictional resistance between the inner ring 2 and the table 9 is greatly increased, and the inner ring 2 is securely placed on the table 9. It is possible to rotate it integrally while holding it. Then, by measuring the back pressure with an air micrometer while rotating the inner ring 2 together with the table 9, the roundness of the inner diameter surface of the through hole 5 can be measured.

  That is, by adopting a means for placing the weight portion 10 at the time of measurement, even a lightweight workpiece 7 such as the inner ring 2 can be reliably secured without the need to fix it on the table 9 each time it is measured. And it becomes possible to measure roundness promptly. Therefore, according to the roundness measuring device of this example, it is possible to perform roundness measurement of the through hole 5 of the inner ring 2 in the form of 100% inspection on the production line.

  As shown in FIG. 1 and the like, the diameter of the outer peripheral surface 15 of the measuring head 6 is the same as the diameter of the portion located in the through hole 18 of the weight portion 10 when measuring the roundness. The diameter is slightly smaller than the diameter of the lower end portion that is opened. By providing in this way, when rotating the inner ring 2 and the weight part 10 in synchronization with the table 9, the inner diameter surface of the through hole 18 of the weight part 10 is prevented from hitting the measuring head 6 and being worn.

  In the standby state shown in FIG. 2, the inner ring 2 after completion of the measurement is replaced with the inner ring 2 scheduled to be measured next time. At this time, the through hole 18 provided in the weight portion 10 is used to Perform calibration. Specifically, in the measuring head 6 at the upper standby position (correction position) for exchanging the inner ring 2, air is ejected from a pair of nozzle ports 16 facing the inner diameter surface of the through hole 18 of the weight portion 10. The inner diameter of the through hole 18 is measured, and the air micrometer is calibrated based on the measurement result.

  That is, the weight unit 10 has a function as a reference unit 23 of an air micrometer used when replacing the inner ring 2 in addition to a function of adding weight to the lightweight inner ring 2 at the time of measurement. Therefore, the micrometer can be calibrated immediately before measuring one inner ring 2, and even when a large number of inner rings 2 are measured one after another, the inner diameter and roundness thereof are precisely measured. It becomes possible.

  FIG. 3 shows an example in which the roundness measuring process using the roundness measuring apparatus of this example is incorporated in the production line of the inner ring 2. In the example shown in the figure, the roundness measurement using the roundness measuring apparatus of this example is performed after performing the steps of material charging, end surface polishing, raceway surface polishing, contact surface polishing with the roller end surface, and inner surface polishing in this order. A process is implemented, and a track surface superfinishing process and an assembly process are implemented in order after that.

  In the roundness measurement step, the inner ring 2 after the inner surface polishing is sequentially conveyed onto the table 9 of the roundness measuring device, the weight 10 is placed on the upper surface of the conveyed inner ring 2 and the inside of the through hole 5 is placed. The roundness is measured by inserting the measuring head 6 and rotating the table 9. In the previous raceway surface and inner diameter surface polishing step, polishing oil adheres to the surface of the inner ring 2, but since the upper surface 13 of the table 9 is provided with a number of fine grooves 14 as described above, As the polishing oil escapes through the fine grooves 14, the slip of the inner ring 2 due to the oil film is prevented.

  When both the inner diameter and the roundness of the through-hole 5 measured by the air micrometer are within the appropriate ranges, the inner ring 2 is conveyed as it is to the next raceway surface superfinishing process. On the other hand, when at least one of the inner diameter and the roundness of the through hole 5 falls outside the proper range, the inner ring 2 is removed from the production line without being transported to the next process.

  In addition, although the inner ring | wheel 2 shown in FIG. 1, FIG. 2 becomes a form which does not have a collar part, when manufacturing the inner ring 2 of a form which has a collar part, a track surface grinding | polishing process shown in FIG. Further, a side surface polishing step is incorporated between the inner surface polishing step and the inner surface polishing step.

  Thus, according to the roundness measuring apparatus of this example, the inner diameter inspection and the roundness inspection of the through-hole 5 of the inner ring 2 can be performed quickly and accurately in the form of a total inspection on the production line. Can do. Moreover, since a complicated structure is not necessary to realize such measurement, the 100% inspection can be performed at a low cost.

  In this example, a mechanism for rotating only the table 9 at the time of measurement is adopted as the rotational drive mechanism 12 to realize further cost reduction, but other mechanisms may be used. That is, any mechanism that rotates the table 9 and the measuring head 6 relative to the center of the vertical axis A at the time of measurement may be used. For example, a mechanism that rotates only the measuring head 6 may be used. It may be a mechanism that rotates the head 6 together.

The measurement state of an example roundness measuring device in an embodiment of the present invention is shown, (a) is a schematic side sectional view and (b) is the P section enlarged view of (a). It is a schematic sectional side view which shows the standby state of a roundness measuring apparatus same as the above. It is flow explanatory drawing of the inner ring manufacturing process of a tapered roller bearing which has a roundness measurement process using the roundness measuring apparatus same as the above. It is explanatory drawing of a tapered roller bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tapered roller bearing 2 Inner ring 5 Through-hole 6 Measuring head 7 Work piece 8 Circular recessed part 9 Table 10 Weight part 11 Vertical drive mechanism 12 Rotation drive mechanism 13 Upper surface 14 Fine groove 20 Lift mechanism

Claims (5)

  A table on which a workpiece having a circular recess to be measured is arranged, an air micrometer measurement head inserted from above into the circular recess of the workpiece arranged on the table, and an upper surface of the workpiece arranged on the table A roundness measuring apparatus, comprising: a weight portion that is placed on the head, a vertical drive mechanism that moves the weight portion up and down, and a rotational drive mechanism that relatively rotates the table and the measurement head during measurement.   The true vertical drive mechanism is a lift mechanism that holds the weight part above the workpiece before and after measurement, and lowers the weight part and places it on the upper surface of the work during measurement. Circularity measuring device.   3. The roundness measuring apparatus according to claim 1, wherein the rotation driving mechanism rotates only the table side during measurement.   The roundness measuring device according to any one of claims 1 to 3, wherein a number of fine grooves for allowing abrasive oil attached to the work to escape are formed on the upper surface of the table. The roundness measuring apparatus according to any one of claims 1 to 4, wherein the circular recess into which the measurement head is inserted is a through-hole having a circular cross section formed in the workpiece.

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