JP2008102113A - Method for manufacturing rolling device - Google Patents

Abstract

A method of manufacturing a rolling device capable of reducing costs and man-hours is provided.
An electromagnetic induction sensor comprising an excitation coil and an induction coil when inspecting whether oxide inclusions having an average length exceeding 200 μm are present in a measured object 17 such as a raceway ring. 12 is used to check for the presence of oxide inclusions having an average length exceeding 200 μm.
[Selection] Figure 2

Description

  The present invention relates to a method for manufacturing a rolling device such as a rolling bearing, a ball screw, and a linear motion guide bearing device, and in particular, to suppress a variation in life between products and to realize a long life stably. It relates to effective technology.

Rolling devices such as rolling bearings are used under repeated shear stress under high surface pressure. For this reason, any rolling device has a rolling fatigue life, and the number of non-metallic inclusions present in the steel material, particularly oxide inclusions such as Al ₂ O ₃ , SiO ₂ , MgO, and CaO. It is known that the size has a large influence on the rolling fatigue life. Therefore, various techniques have been proposed for inspecting the number and size of non-metallic inclusions present in steel and limiting them so as to make the rolling life fatigue of the rolling device as long as possible.

For example, in Patent Document 1, as a method for selecting a rolling device component material that hardly causes peeling, the number of oxide inclusions and the average particle size per 160 mm ² are 200 or less, 3 μm or more, and 30 μm or more. After selecting the following steel materials, a first selection step of selecting steel materials having a ratio of oxide inclusions with an average particle diameter of 10 μm or more in the selected steel materials of 4% or less, and rolling from the raceway surface. A technology for selecting rolling device component materials through a second selection step of selecting steel materials having an average length of oxide inclusions within a range up to a depth corresponding to 2% of the diameter of the moving body and having an average length of 200 μm or less. Is disclosed.

In Patent Document 2, a steel material having a length of 0.5 mm or more and a total length of inclusions present per 1.0 × 10 ⁶ mm ³ of 80 mm or less is selected from a plurality of steel materials. A first selection step, a steel processing step for obtaining a plurality of members by processing the steel selected in the first selection step into a predetermined shape, and a plurality of members obtained in the steel processing step In the second selection step of selecting members having a square root length of 200 μm or less of all inclusions existing within a range corresponding to 2% of the rolling element diameter from the rolling element rolling surface. Techniques for manufacturing the device are disclosed.
JP 2004-28222 A JP 2005-201330 A

  However, the techniques disclosed in Patent Documents 1 and 2 use an ultrasonic flaw detection method to detect oxide inclusions when an average inclusion having an average length of 200 μm or less is detected in the second selection step. Is detected. For this reason, there is a problem that an ultrasonic transmission medium such as a liquid is required, and the inspection apparatus is increased in size and the inspection cost is increased. In addition, since a process such as cleaning is required, there is a problem that man-hours increase.

  The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a method of manufacturing a rolling device capable of reducing costs and man-hours.

In order to achieve the above object, the method of manufacturing a rolling device according to the first aspect of the present invention is such that the number of oxide inclusions present per 160 mm ² and the average particle size are 200 or less and 3 to 30 μm. A first selection step for selecting a steel material having a ratio of oxide inclusions with an average particle diameter of 10 μm or more among the selected steel materials, and rolling elements from the raceway surface A steel member selected from a steel material selected through a second selection step of selecting a steel material having an average length of oxide inclusions within a range corresponding to a depth corresponding to 2% of the diameter of 200 μm or less; A rolling device manufacturing method in which at least one of a side member and a rolling element is formed, and when the presence or absence of oxide inclusions having an average length exceeding 200 μm in the second selection step, A device for inspecting for the presence of oxide inclusions; Whether or not the average length of the oxide inclusions is 200 μm or less based on a change in induced electromotive force generated in the induction coil of the electromagnetic induction sensor using an electromagnetic induction sensor having an excitation coil and an induction coil. It is characterized by inspecting.

According to a second aspect of the present invention, there is provided a rolling device manufacturing method comprising: a steel material having a length of 0.5 mm or more and a total length of inclusions present per 1.0 × 10 ⁶ mm ³ of 80 mm or less. A first selection step for selecting from among a plurality of steel materials, a steel material processing step for obtaining a plurality of members by processing the steel materials selected in the first selection step into a predetermined shape, and the steel material processing step. A second member that selects members having a square root length of 200 μm or less of all the inclusions existing within a depth range corresponding to 2% of the rolling element diameter from the rolling element rolling surface among the plurality of members formed A rolling device manufacturing method manufactured through a selection process, the square root length of all inclusions existing within a depth range corresponding to 2% of the rolling element diameter from the rolling element rolling surface. When selecting a member having a thickness of 200 μm or less, the square of the inclusions is obtained using an electromagnetic induction method. Length characterized by selecting the following member 200 [mu] m.

A rolling device manufacturing method according to a third aspect of the present invention is the rolling device manufacturing method according to the first or second aspect, wherein the first selection step is performed using image processing using a microscope. Features.
A rolling device manufacturing method according to a fourth aspect of the present invention is the rolling device manufacturing method according to the first or second aspect, wherein the first selection step is performed using an emission spectroscopic analysis method. And

According to the method for manufacturing a rolling device according to the first aspect of the invention, it is necessary to use an ultrasonic flaw detection method in the presence or absence of oxide inclusions having an average length exceeding 200 μm in the second selection step. Therefore, it is possible to reduce inspection costs and man-hours.
According to the method for manufacturing a rolling device according to the second aspect of the present invention, the square root lengths of all the inclusions existing within a range corresponding to 2% of the rolling element diameter from the rolling element rolling surface are When selecting a member of 200 μm or less, it is not necessary to select a member having a square root length of 200 μm or less using an ultrasonic flaw detection method, so that inspection costs and man-hours can be reduced.

In addition, by evaluating the inclusions present in the steel material by the electromagnetic induction method, it is possible to perform evaluation using actual members and to perform a wide range of inspections. A moving device can be manufactured.
Furthermore, the long life of a rolling device component can be guaranteed by using the steel material whose inclusion is in the above-mentioned range as the material of the rolling device component.

Hereinafter, a method for manufacturing a rolling device according to the present invention will be described with reference to the drawings.
The method for manufacturing a rolling device according to the first aspect of the present invention is to select a steel material having a number and size of oxide inclusions per 160 mm ² of 200 or less, 3 μm or more and 30 μm or less, and then selected steel materials. First selection step of selecting steel materials having a ratio of oxide inclusions with an average particle diameter of 10 μm or more in the range of 4% or less, and a range from the raceway surface to a depth corresponding to 2% of the rolling element diameter Forming at least one of an inner member, an outer member, and a rolling element from the steel material selected through a second selection step of selecting a steel material having an average length of oxide inclusions within 200 μm or less. In the second selection step, the steel inclusion inspection apparatus 10 shown in FIGS. 1 and 2 is used to exist within a range from the raceway surface to a depth corresponding to 2% of the rolling element diameter. The average length of oxide inclusions to be To elect the wood. In the first selection step, a steel material having a ratio of 4% or less of oxide inclusions having an average particle diameter of 10 μm or more is selected by using image processing using a microscope or emission spectroscopic analysis.

  1 includes an AC power supply 11 that outputs an AC current, an excitation coil 12a that generates an AC magnetic field by the AC current output from the AC power supply 11, and a housing integrated with the excitation coil 12a. An induction coil 12b provided in the body, an inductance change detection circuit 13 for detecting an inductance change of the induction coil 12b, and an inductance change detected by the inductance change detection circuit 13 are compared with a preset threshold value. When the detection value of the change detection circuit 13 is larger than the threshold value, the comparison determination circuit 14 for determining that an oxide inclusion having an average length exceeding 200 μm exists in the steel, and the determination result of the comparison determination circuit 14 are displayed. A display 15 and a recording device 16 for recording the determination result of the comparison determination circuit 14 on a recording medium such as recording paper; With which the exciting coil 12a and the induction coil 12b constitute an electromagnetic induction sensor 12 for detecting the inclusions in steel, such as oxide inclusions by an electromagnetic induction method.

  Further, as shown in FIG. 2, the steel inclusion inspection apparatus 10 shown in FIG. 1 moves around the object to be measured 17 (in this case, the inner raceway) around the vertical axis (θ direction in the figure). ), An electromagnetic induction sensor 12 disposed above the turntable 18, and a sensor mechanism 19 capable of setting the position of the electromagnetic induction sensor 12 about a vertical axis (θ direction in the figure) The electromagnetic induction sensor 12 is moved in the direction of the arrow X and the arrow Y in the figure via the sensor mechanism 19 and is provided with a sensor positioning mechanism 20 for positioning the sensor.

  As shown in FIG. 3, the electromagnetic induction sensor 12 is composed of an induction coil 12b and an excitation coil 12a that is partly brought into contact with the induction coil 12b and wound coaxially with the induction coil 12b. Is connected to a detection circuit (not shown) for detecting a change in an alternating magnetic field generated by excitation of the excitation coil 12a from an induced electromotive force generated in the induction coil 12b. In addition, by storing the exciting coil 12a and the induction coil 12b in an integrated housing, it is possible to reduce the size as an integrated unit and improve workability, and it is possible to detect a defect by installing it in a narrow space inside the rolling bearing. it can.

  As a procedure for inspecting the presence or absence of oxide inclusions having an average length exceeding 200 μm using the inclusion inclusion inspection apparatus 10 configured as described above, detection of the electromagnetic induction sensor 12 as shown in FIG. The electromagnetic induction sensor 12 is brought close to the measurement object 17 so that the surface faces the outer peripheral surface of the measurement object 17, and an alternating current is supplied from the alternating current power supply 11 to the excitation coil 12 a of the electromagnetic induction sensor 12 in this state. Then, as shown in FIG. 5, an alternating magnetic field 22 is generated by the alternating current supplied to the exciting coil 12a. At this time, a range from the outer peripheral surface of the DUT 17 to a depth corresponding to 2% of the rolling element diameter. When oxide inclusions are present in the inside, the magnetic flux density of the alternating magnetic field 22 changes according to the size of the oxide inclusions present in the DUT 17.

  Further, when an AC magnetic field 22 is generated by an AC current supplied from the AC power supply 11 to the exciting coil 12a, an induced electromotive force is generated in the induction coil 12b. At this time, since the induced electromotive force generated in the induction coil 12b changes according to the magnetic flux density of the AC magnetic field, the inductance change of the induction coil 12b is detected by the inductance change detection circuit 13, and the detected value of the inductance change detection circuit 13 and By comparing the threshold value with the comparison / determination circuit 14, it is possible to inspect the presence or absence of oxide inclusions having an average length exceeding 200 μm.

Therefore, in one embodiment of the first invention described above, it is not necessary to use the ultrasonic flaw detection method when inspecting for the presence of oxide inclusions having an average length exceeding 200 μm in the second selection step. Inspection costs and man-hours can be reduced.
In one embodiment of the first invention described above, the detection surface of the electromagnetic induction sensor 12 is opposed to the outer peripheral surface of the inner race, and the presence of oxide inclusions is inspected. In the case of a ring material, as shown in FIG. 6, the presence or absence of oxide inclusions may be inspected with the detection surface of the electromagnetic induction sensor 12 facing the inner peripheral surface of the outer raceway ring. In FIG. 6, reference numeral 21 denotes a swing mechanism that swings the electromagnetic induction sensor 12 about a vertical axis (θ direction in the figure), and a sensor that enables the electromagnetic induction sensor 12 to be driven up and down in the arrow Z direction in the figure. It is a sensor mechanism having a lifting mechanism.

In the embodiment of the first invention described above, the second selection process is performed after the first selection process. However, the present invention is not limited to this. For example, the first selection process is performed after the second selection process. The selection process may be performed.
Next, a method for manufacturing a rolling device according to the second invention will be described with reference to FIGS.
FIG. 7 is a flowchart for explaining a method for manufacturing a rolling device according to the second invention. As shown in FIG. 7, in the method for manufacturing a rolling device according to the second invention, first, a. A steel material having a length of 5 mm or more and a total length of inclusions present per 1.0 × 10 ⁶ mm ³ of 80 mm or less is selected from a plurality of steel materials (first selection step). Next, after the steel material selected in the first selection process is processed into a predetermined shape to obtain a plurality of members (steel material processing step), rolling is performed from the rolling element rolling surface among the plurality of obtained members. A member having a square root length of 200 μm or less of all inclusions existing within a depth range corresponding to 2% of the moving body diameter is selected (second selection step).

Among the plurality of members obtained in the steel material processing step, members having a square root length of 200 μm or less of all inclusions existing within a depth range corresponding to 2% of the rolling element diameter from the rolling element rolling surface When selecting, in one embodiment of the second invention, a member whose inclusion has a square root length of 200 μm or less is selected by using the steel inclusion inspection apparatus having the configuration shown in FIG.
The inclusion inspection apparatus shown in FIG. 8 detects an excitation coil 12a, an AC power supply 11 that supplies an AC current to the excitation coil 12a, and an impedance change of the AC current supplied from the AC power supply 11 to the excitation coil 12a. When the impedance change detection circuit 23 compares the impedance change detected by the impedance change detection circuit 23 with a preset threshold value and the detected value of the impedance change detection circuit 23 is smaller than the threshold value, the object to be measured (steel material processing step) The member processed into a predetermined shape at 17) is determined to have a square root length of 200 μm or less of all inclusions existing within a depth range corresponding to 2% of the rolling element diameter from the rolling element rolling surface of 17. The comparison determination circuit 14, the display 15 for displaying the determination result of the comparison determination circuit 14, and the determination result of the comparison determination circuit 14 for recording paper It is constituted by a recording device 16 for recording on any recording medium.

  In such a configuration, when the exciting coil 12a is brought close to the device under test 17 and an alternating current is supplied from the alternating current power source 11 to the exciting coil 12a in this state, an alternating magnetic field is generated around the exciting coil 12a. Since the magnetic flux density of the AC magnetic field generated at this time changes according to the size of the inclusions present in the DUT 17, the change in impedance of the AC current supplied from the AC power supply 11 to the exciting coil 12a is detected as an impedance change. A depth corresponding to 2% of the rolling element diameter from the rolling element rolling surface of the object to be measured 17 is detected by the circuit 23 and the detection value of the impedance change detection circuit 23 is compared with the threshold value by the comparison determination circuit 14. It is possible to inspect whether or not the square root length of all the inclusions existing in the range is 200 μm or less. Therefore, the square root length of all the inclusions within a range corresponding to 2% of the rolling element diameter from the rolling element rolling surface of the plurality of members obtained in the steel material processing step is 200 μm or less. When selecting a member, a member having an inclusion square root length of 200 μm or less is selected by using the inclusion inspection apparatus having the configuration shown in FIG. 8, thereby using the ultrasonic flaw detection method to find the square root length of the inclusion. Since it is not necessary to select a member having a length of 200 μm or less, inspection costs and man-hours can be reduced.

  In the embodiment of the second aspect of the present invention described above, the inclusion in-steel inspection apparatus having the structure shown in FIG. 8 is used as means for selecting a member whose inclusion has a square root length of 200 μm or less. The inclusion inspection apparatus having the configuration shown, that is, the electromagnetic induction sensor 12 including the excitation coil 12a and the induction coil 12b, the inductance change detection circuit 13 for detecting the inductance change of the induction coil 12b of the electromagnetic induction sensor 12, and the inductance change The inductance change detected by the detection circuit 13 is compared with a preset threshold value. When the detection value of the inductance change detection circuit 13 is smaller than the threshold value, inclusions whose average length exceeds 200 μm exist in the DUT 17. Then, by using an inclusion inspection apparatus comprising a comparison / determination circuit 14 for determination, the inclusions present inside can be referred to. Can be measured more accurately.

It is a figure which shows schematic structure of the inclusion inspection apparatus used when test | inspecting the presence or absence of the oxide type inclusion whose average length exceeds 200 micrometers. It is a perspective view of the inclusion inspection apparatus shown in FIG. It is a figure which shows schematic structure of the electromagnetic induction sensor shown in FIG.1 and FIG.2. It is a figure for demonstrating the procedure in the case of test | inspecting the presence or absence of the oxide type inclusion which average length exceeds 200 micrometers using the electromagnetic induction sensor shown in FIG. It is a figure for demonstrating the alternating current magnetic field generate | occur | produced with the exciting coil of the electromagnetic induction sensor. It is a perspective view which shows schematic structure of the inclusion inspection apparatus used when test | inspecting the presence or absence of the oxide type inclusion which exists in an outer ring material. It is a flowchart for demonstrating the manufacturing method of the rolling device which concerns on 2nd invention. It is a figure which shows an example of the inclusion inspection apparatus used for the manufacturing method of the rolling device which concerns on 2nd invention. It is a figure which shows the other example of the inclusion inspection apparatus used for the manufacturing method of the rolling device which concerns on 2nd invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inclusion inspection apparatus 11 AC power supply 12 Electromagnetic induction sensor 12a Excitation coil 12b Induction coil 13 Inductance change detection circuit 14 Comparison determination circuit 15 Display 16 Recording apparatus 17 Measured object (track ring)
18 Turntable 19, 21 Sensor mechanism 20 Sensor positioning mechanism 23 Impedance change detection circuit

Claims (4)

The number of oxide inclusions present per 160 mm ² and the average particle diameter of 200 or less, steel materials having a particle size of 3 μm or more and 30 μm or less are selected, and then the oxide-based inclusions having an average particle diameter of 10 μm or more among the selected steel materials. The first selection process for selecting steel materials with a ratio of inclusions of 4% or less, and the average length of oxide inclusions in the range from the raceway surface to a depth corresponding to 2% of the rolling element diameter Is a method of manufacturing a rolling device in which at least one of an inner member, an outer member, and a rolling element is formed from a steel material selected through a second selection step of selecting a steel material of 200 μm or less,
When inspecting the presence or absence of oxide inclusions having an average length exceeding 200 μm in the second selection step, an electromagnetic wave having an excitation coil and an induction coil is used as a device for inspecting the presence or absence of oxide inclusions. A rolling device characterized by using an induction sensor and inspecting whether an average length of the oxide inclusions is 200 μm or less from a change in induced electromotive force generated in an induction coil of the electromagnetic induction sensor Manufacturing method. A first selection step of selecting a steel material having a length of 0.5 mm or more and a total length of inclusions present per 1.0 × 10 ⁶ mm ³ of 80 mm or less from a plurality of steel materials; A steel material processing step in which the steel material selected in the first selection step is processed into a predetermined shape to obtain a plurality of members, and a rolling member rolling surface is rolled out of the plurality of members obtained in the steel material processing step. A rolling device manufacturing method manufactured through a second selection step of selecting members whose square root lengths of all inclusions existing within a depth range corresponding to 2% of the moving body diameter are 200 μm or less. When selecting members having a square root length of 200 μm or less of all inclusions existing within a depth range corresponding to 2% of the rolling element diameter from the rolling element rolling surface, an electromagnetic induction method is used. Select a member whose inclusion has a square root length of 200 μm or less. Method of manufacturing a rolling device characterized.   The method for manufacturing a rolling device according to claim 1, wherein the first selection step is performed using image processing using a microscope.   The method for manufacturing a rolling device according to claim 1, wherein the first selection step is performed using an emission spectroscopic analysis method.

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