JP2012233712A - Fatigue testing device and fatigue testing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fatigue testing device 1 that can test specimen easily and grasp a fatigue state of the specimen correctly.SOLUTION: A present fatigue testing device 1 is for grasping fatigue state of specimen elongated in a direction. The fatigue testing device 1 includes: a device body 10; a rolling body 30; and support means 20. The rolling body 30 contacts an outer peripheral surface of specimen rotatably installed on the device body 10 to roll according to rotation of the specimen. The support means 20 is installed on the device body 10 so as to support the rolling body 30 at at least three portions.

Description

  The present invention relates to a fatigue test apparatus, and more particularly to a fatigue test apparatus for testing metal fatigue. The present invention also relates to a fatigue test method for testing metal fatigue using a fatigue test apparatus.

  Conventionally, various types of fatigue testing apparatuses for testing metal fatigue have been proposed. As one of these fatigue test apparatuses, there is a fatigue test apparatus for examining the performance of a bearing. For example, in this type of fatigue test apparatus, the bearing body is mounted on the fatigue test apparatus, and the bearing body is rotated in the fatigue test apparatus (see Patent Document 1). When the bearing body reaches a fatigued state, the bearing body is disassembled, and the fatigue strength of each member constituting the bearing body is individually examined and evaluated. On the other hand, there is also a fatigue test apparatus for directly examining the fatigue state of each member. For example, in this type of fatigue test apparatus, a plurality of ball bodies are arranged between upper and lower rotating plate surfaces, and the fatigue strength of the ball bodies (rolling bodies) is examined and evaluated (see Patent Document 2).

JP 2009-287628 A JP 2006-184169 A

  In the conventional fatigue test apparatus, after the bearing main body is brought into a fatigue state by the fatigue test apparatus, the bearing main body is disassembled into each member, and the fatigue strength of each member is individually examined. Since the fatigue strength of each member varies depending on parameters such as the material and the number of rotations, in order to evaluate the fatigue strength of each member, it is necessary to test by changing the parameters. However, in the conventional method, in order to change the parameter, it is necessary to mount the bearing main body on the fatigue test apparatus by the number of parameters and to disassemble the bearing main body. That is, in the conventional fatigue test apparatus, a great amount of labor is required to examine the fatigue strength of the member.

  On the other hand, another type of conventional fatigue test apparatus can directly examine the fatigue strength of a member, for example, the fatigue strength of a ball body of a bearing. In this fatigue test apparatus, a plurality of ball bodies are arranged between upper and lower rotating plate surfaces in order to simulate a bearing body. In this case, since each of the plurality of ball bodies moves while rotating between the plate surfaces, or adjacent ball bodies collide with each other, it is difficult to specify the cause of the fatigue of the ball bodies. Further, since the trajectory when the ball moves between the plate surfaces is not stable, it is difficult to accurately determine the influence of the ball on the plate surface. In other words, in order to investigate the fatigue state of the bearing race, even if a fatigue test is performed using a plurality of ball bodies, as in the case of the above-mentioned ball bodies, the collision between the ball bodies and the instability of the ball trajectory For example, it is difficult to accurately determine the cause of race fatigue and the fatigue state of the race.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fatigue test that can easily test a specimen and accurately grasp the fatigue state of the specimen. The device is to provide.

  A fatigue test apparatus according to claim 1 is a fatigue test apparatus for grasping fatigue of a test specimen that is long in one direction. The fatigue test apparatus includes an apparatus main body, rolling elements, and support means. The rolling element comes into contact with the outer peripheral surface of the test body that is rotatably mounted on the apparatus main body, and rolls according to the rotation of the test body. The support means is provided in the apparatus main body, and supports the rolling elements at at least three locations.

  In this fatigue test apparatus, first, a test body is rotatably mounted on the apparatus main body. Next, the rolling element is supported at least at three locations by the support means provided in the apparatus main body. Subsequently, the test body is rotated in a state where the rolling element is in contact with the outer peripheral surface of the test body. Then, according to rotation of this test body, a rolling element rolls.

  As described above, in this fatigue test apparatus, the rolling element is rolled by rotating the rolling element supported by the supporting means in a state where the rolling element is in contact with the specimen. Thereby, in this fatigue test apparatus, the influence which a test body receives from a rolling element when the rolling element is rolling in the state which contacted the test object, ie, the fatigue state of a test object, can be investigated.

  For this reason, in this fatigue test apparatus, when the fatigue test is completed, it is possible to directly examine the fatigue state of the test body simply by removing the test body from the fatigue test apparatus. Moreover, in this fatigue test apparatus, the influence which a test body receives from only one rolling element can be investigated directly. Moreover, in this fatigue test apparatus, since the rolling element is supported by the support means at three or more places, the rolling element can be stably rolled. In particular, in this fatigue test apparatus, since the rolling element is brought into contact with the outer peripheral surface of the test body while the rolling element is supported at three or more places by the support means, the rotation of the test body is performed when the test body rotates. The rolling element can be reliably brought into contact with the test body on the line where the surface orthogonal to the axis and the outer peripheral surface of the test body intersect. That is, the position where the rolling element contacts the test body, that is, the input position of the stress from the rolling element to the test body can be stabilized. Thereby, the influence which a test body receives from a rolling element can be investigated correctly. Thus, in this fatigue test apparatus, it is possible to easily test the specimen and to accurately grasp the fatigue state of the specimen.

  In the fatigue test apparatus according to claim 2, in the fatigue test apparatus according to claim 1, the rolling element is sandwiched between the test body and the support means. In this case, since the rolling element is sandwiched between the test body mounted on the apparatus main body and the supporting means, when the test body is rotated, the rolling element is stably brought into contact with the test body. Can be rolled. For example, even if at least one of the test body and the rolling element is worn or deformed, the rolling body can be rolled while being reliably in contact with the test body. Thereby, the influence which a test body receives from a rolling element can be investigated more correctly.

  In the fatigue test apparatus according to a third aspect, in the fatigue test apparatus according to the first or second aspect, the support means supports the rolling element so that it can roll in one direction. In this case, since the supporting means supports the rolling element so that it can roll in one direction, the position where the rolling element contacts the test body can be reliably stabilized. Thereby, the influence which a test body receives from a rolling element can be investigated more correctly.

  The fatigue test apparatus according to claim 4 is the fatigue test apparatus according to any one of claims 1 to 3, wherein the support means includes a support body and four bearings attached to the support body. . The rolling elements are supported at four locations by four bearings. In this case, since the rolling element is supported at four locations by the four bearings, the rolling element can be stably supported. Moreover, a rolling element can be smoothly rolled by supporting a rolling element with a bearing.

  In the fatigue test apparatus according to claim 5, in the fatigue test apparatus according to claim 4, the two bearings are rotatable with respect to the second rotation shaft arranged in parallel with the first rotation shaft of the test body, It is attached to the support body. The other two bearings are mounted on the support body so as to be rotatable with respect to a third rotation shaft arranged in parallel with the second rotation shaft.

  In this case, the rolling element is supported at four locations by the four bearings between the second rotating shaft and the third rotating shaft. That is, the rolling element is supported at four locations between two bearings arranged coaxially on the second rotating shaft and two other bearings arranged coaxially on the third rotating shaft. For this reason, the rolling element can be smoothly rolled in the direction in which the bearing rotates. That is, the position where the rolling element contacts the test body, that is, the input position of the stress from the rolling element to the test body can be fixed. Thereby, since the influence which a test body receives from a rolling element can be investigated with high precision, the fatigue state of a test body can be grasped | ascertained correctly.

  In the fatigue test apparatus according to a sixth aspect, in the fatigue test apparatus according to the fourth and fifth aspects, the support means further includes a positioning portion that positions the test body so as to be rotatable with respect to the support body. In this case, since the test body is rotatably positioned with respect to the support main body of the support means by the positioning means of the support means, the positions of the test body and the rolling element can be set with reference to the support means. it can. Thereby, the positional accuracy of a test body and a rolling element can be ensured reliably. That is, since the influence which a test body receives from a rolling element can be investigated with high precision, the fatigue state of a test body can be grasped | ascertained correctly.

  A fatigue test apparatus according to claim 7 is a fatigue test apparatus for grasping fatigue of a spherical test body. The fatigue test apparatus includes an apparatus main body, a shaft member, and support means. The shaft member is rotatably mounted on the apparatus main body. The support means supports the test body in at least three places. The test body contacts the shaft member and rolls according to the rotation of the shaft member.

  In this fatigue test apparatus, first, the shaft member is rotatably mounted on the apparatus main body. Next, the spherical specimen is supported at three locations by the support means provided in the apparatus main body. Subsequently, the shaft member is rotated while the test body is in contact with the outer peripheral surface of the shaft member. Then, the test body rolls according to the rotation of the shaft member.

  Thus, in this fatigue test apparatus, the test body is rolled by rotating the shaft member while the test body supported by the support means is in contact with the shaft member. Thereby, in this fatigue testing apparatus, the influence which a test body receives from a shaft member when the test body rolls in the state which contacted the shaft member, ie, the fatigue state of a spherical test body, can be investigated.

  For this reason, in this fatigue test apparatus, when the fatigue test is completed, it is possible to directly examine the fatigue state of the test body simply by removing the test body from the fatigue test apparatus. Moreover, in this fatigue test apparatus, the influence which one spherical test body receives from a shaft member can be investigated directly. Moreover, in this fatigue test apparatus, since the test body is supported at three places by the support means, the test body can be stably rolled. In particular, in this fatigue test apparatus, since the test body is in contact with the outer peripheral surface of the shaft member with the test body supported at three locations by the support means, when the shaft member rotates, the rotation shaft of the shaft member is rotated. The specimen can be reliably brought into contact with the shaft member on the line where the surface orthogonal to the outer surface of the shaft member intersects. That is, the position where the shaft member contacts the test body, that is, the input position of the stress from the shaft member to the test body can be stabilized. Thereby, the influence which a test body receives from a shaft member can be investigated correctly. Thus, in this fatigue test apparatus, it is possible to easily test the specimen and to accurately grasp the fatigue state of the specimen.

  A fatigue test apparatus according to an eighth aspect is a fatigue test apparatus for grasping fatigue of a first test body that is long in one direction and fatigue of a spherical second test body. The spherical second test body contacts the first test body that is long in one direction, and rolls according to the rotation of the first test body. The fatigue test apparatus includes an apparatus main body and support means. The support means is provided in the apparatus main body, and supports the second test body in at least three places.

  In this fatigue test apparatus, first, a first test body that is long in one direction is rotatably mounted on the apparatus main body. Next, the spherical second specimen is supported at three locations by the support means provided in the apparatus main body. Subsequently, the first test body is rotated while the second test body is in contact with the outer peripheral surface of the first test body. Then, according to the rotation of the second test body, the second test body rolls.

  Thus, in this fatigue test apparatus, the second test body is rolled by rotating the first test body while the second test body supported by the support means is in contact with the first test body. I am letting. Thereby, in this fatigue test apparatus, when the second test body is rolling while being in contact with the first test body, the second test body is affected by the first test body, that is, the spherical second test body. The fatigue state of can be investigated.

  For this reason, in this fatigue test apparatus, when the fatigue test is completed, the fatigue state of the first test body and the second test body can be directly determined by simply removing the first test body and the second test body from the fatigue test apparatus. You can investigate. Moreover, in this fatigue test apparatus, the influence which the 1st test body long in one direction and the one spherical 2nd test body mutually receive can be investigated directly. Moreover, in this fatigue test apparatus, since the 2nd test body is supported at three places by the support means, the 2nd test body can be rolled stably. In particular, in the present fatigue test apparatus, the second test body is in contact with the outer peripheral surface of the first test body in a state where the second test body is supported at three locations by the support means, so the first test body is rotated. Sometimes, the second test body can be reliably brought into contact with the first test body on a line where the surface perpendicular to the rotation axis of the first test body and the outer peripheral surface of the first test body intersect. That is, the position where the first test body and the second test body are in contact, that is, the position where the first test body and the second test body exert stress on each other (stress input position) can be stabilized. Thereby, the influence which one spherical 2nd test body receives mutually can be investigated correctly. Thus, in this fatigue test apparatus, it is possible to easily test the specimen and to accurately grasp the fatigue state of the specimen.

  The fatigue test method according to claim 9 is a fatigue test method for grasping the fatigue of the specimen. Here, the fatigue test apparatus includes an apparatus main body, a shaft member, rolling elements, and support means. The shaft member is rotatably mounted on the apparatus main body. The rolling element rolls according to the rotation of the shaft member. The support means supports the rolling element at at least three locations. In this fatigue test method, at least one of the shaft member and the rolling element is set as a test body.

  The fatigue test method includes a shaft member mounting process, a rolling element arrangement process, a test body setting process, and a test process. In the shaft member mounting step, the shaft member is mounted on the apparatus main body. In the rolling element arranging step, the rolling elements are arranged on the support means attached to the apparatus main body. In the test body setting step, the rolling element is sandwiched between the shaft member and the support means. In the test process, the shaft member is rotated while the rolling element is sandwiched between the shaft member and the support means.

  Thus, in this fatigue test method, the rolling element is rolled by rotating the shaft member while the rolling element is sandwiched between the shaft member and the support means. Thereby, in this fatigue test method, when the rolling element rotates in contact with the shaft member, the shaft member or the rolling element is affected by the rolling element or the shaft member, or the shaft member and the rolling element are mutually connected. You can investigate the impact. That is, the fatigue state (the fatigue state of the test body) of at least one of the shaft member and the rolling element can be examined.

  For this reason, in this fatigue test method, when the fatigue test is completed, the fatigue state of at least one of the shaft member and the rolling element is simply removed from the fatigue test apparatus by removing at least one of the shaft member and the rolling element. Can be examined directly. Further, in this fatigue test method, since one rolling element rolls in contact with the shaft member, the influence of the rolling element on the shaft member and the influence of the shaft member on the rolling element can be directly examined. it can. Furthermore, in this fatigue test method, since the rolling element is supported at three places by the supporting means, the rolling element can be stably rolled. That is, since the position where the rolling element contacts the shaft member can be stabilized by the support means, the influence that the shaft member receives from the rolling element (the influence that the rolling element receives from the shaft member) can be accurately examined. Thus, in this fatigue test method, the specimen can be easily tested and the fatigue state of the specimen can be accurately grasped.

  The fatigue test method according to claim 10 is the fatigue test method according to claim 9, further comprising a retest step. In the retest process, the shaft member is moved with respect to the apparatus main body and mounted again. In this case, in the test body setting step, the rolling element is sandwiched again by the moved shaft member and the support means. And in a test process, a shaft member is rotated again in the state where a rolling element was pinched by shaft member and support means after movement.

  In this case, after the first fatigue test is completed, the shaft member used here is moved relative to the apparatus main body and mounted again. And the 2nd fatigue test is performed by rotating the shaft member after a movement. That is, the fatigue test can be repeatedly executed by simply moving the shaft member. Thereby, a some fatigue test can be performed easily. In addition, since a plurality of fatigue test results can be obtained from one shaft member having the same distribution of inclusions, it is possible to qualitatively understand the influence of the inclusions on the fatigue state of the shaft member.

  In the fatigue test method according to claim 11, in the fatigue test method according to claim 10, the shaft member is arranged such that the number of rotations of the shaft member before movement differs from the number of rotations of the shaft member after movement. Rotated. This process is realized in the test process.

  In this case, the results of a plurality of fatigue tests can be obtained by changing the number of rotations of the shaft member. For this reason, by observing the cross-section of the shaft member at the result of each fatigue test, that is, at the position where the rolling element contacts the shaft member in each fatigue test, the process in which damage grows on the shaft member based on the inclusions, It is possible to grasp with certainty. That is, the fatigue state of the shaft member can be grasped more accurately.

  In the present invention, the specimen can be easily tested, and the fatigue state of the specimen can be accurately grasped.

1 is an overall view of a fatigue test apparatus according to an embodiment of the present invention as viewed from the front. The whole figure which looked at the fatigue test device from the side. The elements on larger scale which looked at the support means of the said fatigue test apparatus from the side. The perspective view which looked at the said support means from upper direction. The partial perspective view of the said support means, a shaft member, and a rolling element. The figure which shows the process at the time of performing a fatigue test. The schematic diagram which shows the positional relationship of the one rolling element and the bearing for three rolling elements in other embodiment of this invention. The schematic diagram which shows the positional relationship of two rolling elements and the bearing for six rolling elements in other embodiment of this invention.

[Configuration of fatigue test equipment]
A fatigue test apparatus 1 shown in FIGS. 1 and 2 is an apparatus for grasping fatigue of a specimen that is long in one direction. Specifically, the fatigue test apparatus 1 is an apparatus for grasping fatigue of a bearing race. Here, the test body corresponds to a bearing race. As this member, a shaft member 40 having a circular cross section is used. The rolling element 30 corresponds to a ball body of the bearing.

  As shown in FIGS. 1 and 2, the fatigue test apparatus 1 includes an apparatus main body 10, support means 20, rolling elements 30, drive means 50 for rotationally driving a shaft member 40 (test body), and driving. Control means 60 for controlling the means 50 is provided. In this embodiment, as shown in FIG. 5, the outer peripheral part of the shaft member 40 with which the rolling element 30 contacts is defined as the contact region SR. The contact region SR is formed in the circumferential direction on the outer peripheral surface of the shaft member 40.

<Main unit>
As shown in FIGS. 1 and 2, the apparatus body 10 is configured to engage the frame body 11, the holding means 12 for holding the shaft member 40 rotatably, and the shaft member 40 and the rolling element 30. Engaging means 15 and a cover member 19 for preventing scattering of the lubricating oil are provided. The frame body 11 is erected on the floor surface FL.

  The holding means 12 is for holding the shaft member 40 rotatably. As shown in FIG. 1, the holding means 12 includes a plurality of holding members 13, for example, three holding members 13. Support means 20 is disposed between two adjacent holding members 13. Each holding member 13 has a main body member 13a and a first bearing 13b for a shaft member. In FIG. 1, only the central holding member 13 is denoted by reference numerals 13a and 13b. The main body member 13 a is fixed to the frame body 11. Specifically, the three main body members 13a are fixed to the frame body 11 at intervals. The first bearing 13b for the shaft member is mounted on each of the three main body members 13a. Specifically, the outer rings of the first bearings 13b for the three shaft members are fixed to the main body members 13a so that the rotation shafts of the first bearings 13b for the three shaft members are coaxially positioned. ing. The shaft member 40 is inserted into the inner ring of the first bearing 13b for the three shaft members, and is rotatably held by the first bearings 13b for the three shaft members.

  The engagement means 15 is for engaging the shaft member 40 and the rolling element 30 via the support means 20 as shown in FIG. The engagement means 15 includes a weight member 16, a connection member 17 that connects the weight member 16 and the support means 20, and a fulcrum member 18 that is a fulcrum of the connection member 17. Specifically, the engaging means 15 supports the shaft member 40 and the rolling element 30 by using the reaction force against the weight member 16 with the position where the fulcrum member 18 supports the connecting member 17 as a fulcrum. Engage through.

  The connecting member 17 includes a first connecting part 17a to which the support means 20 is attached, a second connecting part 17b to which the weight member 16 is attached, and a third connecting part between the first connecting part 17a and the second connecting part 17b. And a connecting portion 17c. A support means 20 is swingably attached to one end of the first connecting portion 17a. A weight member 16 is attached to one end of the second connecting portion 17b. The other end portion of the first connecting portion 17a is swingably attached to one end portion of the third connecting portion 17c. The other end of the second connecting portion 17b is swingably attached to the other end of the third connecting portion 17c. That is, the support means 20 is connected to one end portion of the third connecting portion 17c via the first connecting portion 17a, and the weight member is connected to the other end portion of the third connecting portion 17c via the second connecting portion 17b. 16 are connected.

  The lower end portion of the fulcrum member 18 is fixed to the upper portion of the frame body 11. The upper end portion of the fulcrum member 18 supports the connecting member 17 at a predetermined position P. Specifically, the third connecting portion 17 c of the connecting member 17 is swingably attached to the upper end portion of the fulcrum member 18. Here, the distance L1 between the fulcrum P where the third connecting portion 17c of the connecting member 17 is supported by the fulcrum member 18 and the swing center Y1 on one end side of the third connecting portion 17c, and the fulcrum and the third connecting portion. The ratio (lever ratio = L1 / L2) to the distance L2 from the swing center Y2 on the other end side of 17c is set to be a predetermined ratio.

  The cover member 19 is for preventing scattering of lubricating oil, as shown in FIGS. The cover member 19 is attached to the frame body 11. For example, a predetermined amount of lubricating oil is injected into the cover member 19 before starting the fatigue test. Thereby, the temperature rise of each member under test can be controlled.

<Supporting means>
As shown in FIGS. 1 to 5, the support means 20 is for supporting the rolling element 30. The support means 20 is provided in the apparatus main body 10. Specifically, as shown in FIG. 2, the support means 20 is supported by the frame body 11 via the engagement means 15. The support means 20 is swingably attached to the connecting member 17, that is, the first connecting portion 17a.

  The support means 20 supports the rolling element 30 in at least three places. Specifically, as shown in FIGS. 3 to 5, the support means 20 supports the rolling elements 30 at four locations so that the rolling elements 30 can roll in one direction. The support means 20 includes a support body 21 and a support portion 25 that supports the rolling elements 30. The support main body 21 includes a pair of plate members 22, a distance holding portion 23 for holding a distance between the pair of plate members 22, and a positioning portion 24 for positioning the shaft member 40 rotatably with respect to the support main body 21. Have.

  As shown in FIG. 4, the pair of plate members 22 are disposed to face each other. As shown in FIG. 4, the interval holding unit 23 includes a first cylindrical member 23 a and a first fixing member 23 b for fixing the first cylindrical member 23 a to the plate member 22. The first cylindrical member 23 a is disposed between the pair of plate members 22. The 1st fixing member 23b is comprised from the volt | bolt and the nut. The shaft portion of the bolt is inserted through the hole of the first cylindrical member 23a, and the nut is screwed into the tip portion of the shaft portion of the bolt. Specifically, first, a bolt shaft portion is formed in a bolt hole formed at a position facing each other in the pair of plate members 22 and a hole of the first cylindrical member 23a disposed between the pair of plate members 22. Is inserted. Then, by tightening the tip of the bolt shaft with a nut, the pair of plate members 22 come close to each other, and the first cylindrical member 23 a is sandwiched between the pair of plate members 22.

  As shown in FIG. 4, the positioning unit 24 has two positioning members 124 provided in each plate member 22 and positioning holes 224 provided in each plate member 22. Each of the two positioning members 124 provided on each plate member 22 includes a second cylindrical member 124a, a second bearing 124b for a shaft member, and a second fixing member 124c. The second cylindrical member 124a is disposed between the plate member 22 and the second bearing 124b for the shaft member. Specifically, the second cylindrical member 124a is disposed between the plate member 22 and the inner ring of the second bearing 124b for the shaft member. The same bearing is used for the second bearings 124b for the four shaft members. That is, the second bearings 124b for the four shaft members have the same inner ring diameter and the same outer ring diameter.

  As shown in FIG. 3, the shaft member second bearings 124 b are provided on the plate member 22 so that the rotation axes X4 of the four shaft member second bearings 124 b are parallel to each other. In other words, the position of the second fixing member 124c with respect to the plate member 22 is determined so that the rotation axes X4 of the four shaft member second bearings 124b are parallel to each other. The second fixing member 124 c fixes the second cylindrical member 124 a and the second bearing 124 b for the shaft member to the plate member 22.

  Specifically, as shown in FIG. 4, the second fixing member 124 c has the second cylindrical member 124 a in a state where the second cylindrical member 124 a is disposed between the plate member 22 and the inner ring of the second bearing 124 b for the shaft member. The member 124 a and the second bearing 124 b for the shaft member are fixed to the plate member 22. Specifically, the second fixing member 124c is composed of a bolt and a nut. The shaft portion of the bolt is inserted into the inner ring of the second bearing 124b for the shaft member and the hole of the second cylindrical member 124a, and the head of the bolt contacts the inner ring of the second bearing 124b for the shaft member through the washer. In this state, the tip of the bolt shaft is screwed into a female screw (not shown) provided on the plate member 22. Thereby, the second bearing 124b for the shaft member is held rotatably with respect to the plate member 22.

  Here, the second distance for the shaft member is such that the distance between the centers of the second shaft bearings 124b for the two shaft members is the sum of the diameter of the shaft member 40 and the diameter of the second bearing 124b for the shaft member. A bearing 124 b is attached to each plate member 22. In other words, the shaft member second bearings 124b are mounted on the plate members 22 so that the minimum distance between the outer peripheral surfaces of the two shaft member second bearings 124b is the diameter of the shaft member 40. Yes.

  The positioning hole 224 is a hole through which the shaft member 40 is inserted, and is provided in each plate member 22. As shown in FIG. 4, the positioning hole 224 is formed between two positioning members 124 provided in each plate member 22. The positioning hole 224 is a long hole that is long in a direction orthogonal to a straight line connecting the rotation centers of the two positioning members 124 provided in each plate member 22. The positioning holes 224, for example, long holes are formed to face each other in the pair of plate members 22. The width of the long hole (the length in the short axis direction) is formed larger than the diameter of the shaft member 40, and the shaft member 40 is movable in the long axis direction of the long hole while being arranged in the long hole. It is.

  The support part 25 is a part that supports the rolling element 30. As shown in FIGS. 3 and 4, the support portion 25 includes four rolling element bearings 26 mounted on the support body 21, a third cylindrical member 27 for positioning the rolling element bearings 26, and A rolling element bearing 26 and a third fixing member 28 for fixing the third cylindrical member 27 are provided. In addition, in FIG. 3, the code | symbols 27 and 28 are attached | subjected only with respect to the 3rd cylindrical member and 3rd fixing member for the 1st bearings 26a for rolling elements.

  As shown in FIG. 4, the four rolling element bearings 26 are rotatably attached to the support body 21. As shown in FIGS. 4 and 5, the four rolling element bearings 26 support the rolling elements 30 at four locations between the pair of plate members 22. The same bearing is used for the bearings 26 for the four rolling elements. That is, the bearings 26 for the four rolling elements have the same inner ring diameter and the same outer ring diameter. As shown in FIG. 3, the four rolling element bearings are such that the rotation axes X2 and X3 of the four rolling element bearings 26 are parallel to the rotation axis X1 (first rotation axis) of the shaft member 40. 26 is rotatably attached to the plate member 22 between the pair of plate members 22.

  As shown in FIGS. 3 to 5, the two first rolling element bearings 26 a among the four rolling element bearings 26 are arranged coaxially. Specifically, the first bearings 26a for the two rolling elements are arranged coaxially so that the distance between the first bearings 26a for the two rolling elements on the same axis is smaller than the diameter of the rolling element 30. Yes. Further, the two first rolling bearings 26a are coaxially arranged so that the distance between the outer rings of the first rolling bearings 26a for the two rolling elements is not less than five times the width of the contact region SR described above. Is arranged. In the first bearings 26a for the two rolling elements, the corners of the two outer rings facing each other are chamfered. This chamfered portion is for stably holding the rolling element 30.

  Further, as shown in FIGS. 3 to 5, the other two rolling element bearings 26 excluding the two rolling element first bearings 26a, ie, the two rolling element second bearings 26b are respectively Are arranged on the same axis. Specifically, the second bearings 26b for the two rolling elements are arranged coaxially so that the interval between the second bearings 26b for the two rolling elements on the same axis is smaller than the diameter of the rolling element 30. Yes. In addition, the two second bearings 26b for the rolling elements are coaxially arranged so that the distance between the outer rings of the second bearings 26b for the two rolling elements is not less than five times the width of the contact region SR described above. Is arranged. In the second bearings 26b for the two rolling elements, the corners of the two outer rings facing each other are chamfered. This chamfered portion is for stably holding the rolling element 30.

  Further, as shown in FIG. 3, the rotation axis X2 (second rotation axis) of the first bearing 26a for the rolling element and the rotation axis X3 (third rotation axis) of the second bearing 26b for the rolling element are: The first bearing 26a for the rolling element and the second bearing 26b for the rolling element are rotatably mounted on the support body 21 so as to be parallel to each other. Further, the rotation axis X2 of the first bearing 26a for the rolling element and the rotation axis X3 of the second bearing 26b for the rolling element are parallel to the rotation axis X4 of the second bearing 124b for the shaft member. A rolling element first bearing 26 a and a rolling element second bearing 26 b are rotatably mounted on the support body 21.

  Further, on the line connecting the rotation axis X2 of the first rolling element bearing 26a and the rotation axis X3 of the second rolling element bearing 26b, the outer peripheral surface of the first rolling element bearing 26a and the rolling element Two first bearings 26a for the rolling elements and two second bearings 26b for the rolling elements are arranged between the pair of plate members 22 so that the outer peripheral surface of the second bearing 26b faces each other. . Here, the distance between the outer peripheral surface of the first rolling element bearing 26 a and the outer peripheral surface of the second rolling element bearing 26 b is set to be smaller than the diameter of the rolling element 30.

  Further, the two rolling elements are set such that the distance between the rotation axis X2 and the rotation axis X3 is larger than the sum of the radius of the first bearing 26a for the rolling element and the radius of the second bearing 26b for the rolling element. The first bearing 26 a for use and the second bearing 26 b for two rolling elements are disposed between the pair of plate members 22. In other words, the distance between the axes is set to be larger than the outer diameter of the first bearing 26a for the rolling element (the outer diameter of the second bearing 26b for the rolling element).

  Thus, by arranging the bearings 26 for the four rolling elements, that is, the first bearing 26a for the two rolling elements and the second bearing 26b for the two rolling elements, between the pair of plate members 22, The rolling element 30 includes two first rolling element bearings 26a between a rotating axis X2 of the first rolling element bearing 26a and a rotating axis X3 of the second rolling element bearing 26b. And it is supported at four places by the 2nd bearing 26b for two rolling elements.

  The four rolling element bearings 26 described above are positioned by a third cylindrical member 27 as shown in FIG. The third cylindrical member 27 is for positioning the first bearing 26a for the rolling element and the second bearing 26b for the rolling element. The first bearing 26 a for the rolling element is positioned by three third cylindrical members 27. Further, the second bearing 26 b for the rolling element is also positioned by the three third cylindrical members 27. Further, the distance between the outer rings is adjusted by the axial length of the third cylindrical member 27.

  The third cylindrical member 27 is between one of the pair of plate members 22 and one of the two first rolling element bearings 26a, between the two first rolling element bearings 26a, It arrange | positions between either one of a pair of plate member 22, and either one of two 1st bearings 26a for two rolling elements. Similarly, the third cylindrical member 27 is provided between any one of the pair of plate members 22 and one of the two second rolling element bearings 26b and between the two second rolling element bearings 26b. And between the other of the pair of plate members 22 and the other of the two second rolling element bearings 26b.

  Each of the three third cylindrical members 27 for positioning the first bearing 26a for the rolling element is in contact with the inner ring of the first bearing 26a for the rolling element. Further, each of the three third cylindrical members 27 for positioning the second bearing 26b for the rolling element is in contact with the inner ring of the second bearing 26b for the rolling element.

  The third fixing member 28 is for fixing the rolling element bearing 26 and the third cylindrical member 27 to the pair of plate members 22. Specifically, the third fixing member 28 fixes the first bearing 26 a for the rolling element and the third cylindrical member 27 to the plate member 22 in a state where the third cylindrical member 27 is disposed at the above position. . Further, the third fixing member 28 fixes the second bearing 26 b for the rolling element and the third cylindrical member 27 to the plate member 22 in a state where the third cylindrical member 27 is disposed at the above position.

  Specifically, the third fixing member 28 includes a bolt and a nut. The bolt shaft portion is inserted into a bolt hole formed in one plate, an inner ring of the first bearing 26a for the rolling element, a hole in the third cylindrical member 27, and a bolt hole formed in the other plate. Is done. Then, in a state where the head portion of the bolt is in contact with one plate member 22 via a washer, the tip portion of the shaft portion of the bolt protruding from the other plate member 22 is tightened by the nut. Thereby, the 1st bearing 26a for rolling elements is rotatably hold | maintained between a pair of plate members 22. FIG. Further, by assembling in the same manner as the first bearing 26 a for the rolling element, the second bearing 26 b for the rolling element is also rotatably held between the pair of plate members 22.

<Rolling elements>
As shown in FIGS. 3 to 5, the rolling element 30 is formed in a spherical shape. Here, the rolling element 30 is formed so that the strength of the rolling element 30 is equal to or higher than the strength of the shaft member 40. As described above, the rolling element 30 is supported by the support means 20. Specifically, the rolling element 30 contacts each of the four rolling element bearings 26 and is supported at four locations. Further, in a state where the rolling element 30 is supported by the four rolling element bearings 26, that is, the two rolling element first bearings 26a and the two rolling element second bearings 26b, the engaging means 15 is provided. When the support means 20 is biased in the direction of the shaft member 40, the rolling element 30 is sandwiched between the first bearing 26 a for the two rolling elements, the second bearing 26 b for the two rolling elements, and the shaft member 40. The In this state, when the shaft member 40 rotates, the rolling element 30 corresponds to the rotation of the shaft member 40, the first bearing 26a for the two rolling elements, the second bearing 26b for the two rolling elements, and the shaft. Rolls with the member 40.

  As described above, the distance between the outer rings of the first bearings 26a for the two rolling elements and the distance between the outer rings of the second bearings 26b for the two rolling elements are not less than five times the distance of the width of the contact region SR. It is set to be. As a result, the influence of the four rolling element bearings 26 (the two rolling element first bearings 26 a and the two rolling element second bearings 26 b) on the rolling element 30 passes through the rolling element 30. , It is considered not to be transmitted to the shaft member 40.

<Drive means>
The driving means 50 is for rotating the shaft member 40. As shown in FIGS. 1 and 2, the drive unit 50 includes a drive motor 50a and a rotation transmission member 50b for transmitting rotation from the drive motor 50a to the shaft member 40. The drive motor 50 a is fixed to the apparatus main body 10, for example, the frame body 11. The rotation of the drive motor 50a is controlled by the control means 60. The rotation transmission member 50b is, for example, a belt. The belt 50b transmits the rotation of the drive motor 50a to the shaft member 40 via the pulley 50c. Specifically, the belt 50b is spanned between the drive motor 50a and the pulley 50c. The pulley 50c is mounted so as to be rotatable together with the shaft member 40. Here, the pulley 50 c is fixed to the shaft member 40 by chucking the pulley 50 c on one end of the shaft member 40.

<Control means>
The control means 60 is for controlling the drive means 50, for example, the drive motor 50a. The control means 60 includes a control device main body 61, an adjustment panel 60a for adjusting the drive motor 50a, a start button 60b for starting rotation of the drive motor 50a, and a stop for stopping rotation of the drive motor 50a. And a button 60c.

  The control device main body 61 is attached to the device main body 10. For example, the control device main body 61 is attached to a standing portion standing on the frame body 11. The adjustment panel 60 a is provided in the control device main body 61. The adjustment panel 60a is a contact input type image display unit, for example, a touch panel. Here, information for adjusting the drive motor 50a is directly input from the adjustment panel 60a. When the start button 60b is pressed, a control signal for controlling the rotation of the drive motor 50a is output from a control unit (not shown) based on information input to the adjustment panel 60a, and the drive motor 50a rotates. On the other hand, when the stop button 60c is pressed, a control signal for stopping the drive motor 50a is output from a control unit (not shown), and the drive motor 50a stops rotating.

  The control unit is built in the control device main body 61. The control unit is composed of, for example, a CPU and a memory. For example, the CPU executes processing related to control of the drive motor 50a. The memory stores various types of information when controlling the drive motor 50a.

  In the present embodiment, the configuration is described using the word “means”, but the word “structure” may be used instead of the word “means”.

[Explanation of fatigue test method]
Below, the fatigue test method using the fatigue test apparatus 1 mentioned above is demonstrated.
Specifically, first, a basic fatigue test (basic fatigue test) using the fatigue test apparatus 1 will be described. Next, a description will be given of a fatigue test (continuous fatigue test) in which a basic fatigue test is continuously performed using only one shaft member (test body). FIG. 6 shows a process when the fatigue test is executed. FIG. 6 shows both steps of the basic fatigue test and the continuous fatigue test shown below.

<Basic fatigue test>
First, in the fatigue test apparatus 1, a weight member 16 having a weight for preparation is attached to the connecting member 17 (second connecting portion 17b) (S1). Next, the shaft member 40 (test body) is attached to the apparatus main body 10 (S2). Specifically, the shaft member 40 is rotatably attached to the holding means 12. More specifically, the shaft member 40 is inserted into the positioning hole 224 of the positioning portion 24 formed in each plate member 22 and the first bearing 13b for the three shaft members, and is inserted into one end portion of the shaft member 40. The pulley 50c is fixed. The belt 50b is bridged between the drive motor 50a and the pulley 50c.

  Then, the rolling element 30 is arrange | positioned at the support means 20 with which the apparatus main body 10 was mounted | worn (S3). Specifically, the rolling elements 30 are arranged on the upper parts of four rolling element bearings 26 (two rolling element first bearings 26a and two rolling element second bearings 26b). Supported. Subsequently, the weight member 16 is attached to the connecting member 17 (second connecting portion 17b) so that the weight of the weight member 16 becomes the weight for testing (S4). Then, on the principle of leverage, the support means 20 is pulled upward by the connecting member 17. Then, the shaft member 40 moves toward the inner peripheral lower surface of the positioning hole 224 (long hole) of the positioning portion 24 formed in each plate member 22. Then, the shaft member 40 comes into contact with the rolling element 30, and the rolling element 30 is sandwiched between the shaft member 40 and the four rolling element bearings 26.

  Further, when the shaft member 40 is in contact with the rolling element 30, the shaft member 40 is disposed between two positioning members 124 provided adjacent to each other in each plate member 22. That is, the shaft member 40 is disposed between the two second shaft member bearings 124 b provided on each plate member 22. Thereby, the movement of the shaft member 40 in the direction parallel to the floor surface FL with respect to each plate member 22 is regulated.

  Thus, the shaft member 40 (test body) is set in the fatigue test apparatus 1 (S5). In this state, the rolling element 30 is in contact with the shaft member 40 at one location, and is in contact with the four rolling element bearings 26 at four locations. Specifically, the upper part of the rolling element 30 is in contact with the lower part of the shaft member 40 at one place, and the lower part of the rolling element 30 is in contact with each of the four rolling element bearings 26 at one place.

  Subsequently, when various types of information are input to the adjustment panel 60a (S6), the shaft member 40 is rotated by the driving means 50, and a fatigue test is started (S7). Specifically, the number of rotations of the drive motor 50a, the maximum number of rotations of the drive motor 50a (test time), and the like are input to the adjustment panel 60a of the control device main body 61. And if the start button 60b of the control apparatus main body 61 is pushed, the drive motor 50a will start rotation. Then, the rolling element 30 rolls between the shaft member 40 and the four rolling element bearings 26 in a state where the rolling element 30 is in contact with the outer peripheral surface of the shaft member 40. Here, the part where the rolling element 30 contacts the outer peripheral surface of the shaft member 40 is referred to as a contact region SR. The contact region SR is formed in the circumferential direction on the outer peripheral surface of the shaft member 40.

  Subsequently, when the rotation of the shaft member 40 reaches a predetermined number of rotations, the rotation of the shaft member 40 is stopped and the test is ended (S8). Specifically, when the drive motor 50a stops rotating based on the input information of the adjustment panel 60a, for example, the maximum number of rotations of the drive motor 50a, the rotation of the shaft member 40 stops. The drive motor 50a also stops rotating when the stop button 60c of the control device main body 61 is pressed. When the drive motor 50a stops rotating in this way, the rolling element 30 stops rolling.

  Subsequently, the shaft member 40 (test body) is removed from the fatigue test apparatus 1 (No in S9 and S10). Specifically, the weight of the weight member 16 is reduced, and the support means 20 is pulled down by the connecting member 17. Thereby, the rolling element 30 separates from the shaft member 40, and the contact between the shaft member 40 and the rolling element 30 is released. Then, the shaft member 40 is removed from the positioning hole 224 of the positioning portion 24 formed in each plate member 22 and the first bearings 13b for the three shaft members.

  Subsequently, the shaft member 40 is cut perpendicular to the shaft core at a position avoiding the contact region SR. Then, the cut surface is polished in the direction of the contact region SR. Then, when the polished surface reaches the contact region SR by polishing the cut surface, the state of the polished surface is observed. For example, here, the influence which the shaft member 40 receives from the rolling element 30, for example, the crack etc. which made the inclusion a base point is observed.

  In such a fatigue test, when the fatigue test is completed, the fatigue state of the shaft member 40 can be directly examined simply by removing the shaft member 40 from the fatigue test apparatus 1. In addition, since one rolling element 30 rolls in contact with the shaft member 40, it is possible to directly examine the influence that the shaft member 40 receives from only one rolling element 30. Furthermore, since the rolling element 30 is supported by the support means 20 at four places, the rolling element 30 can be stably rolled. That is, the rolling element 30 can be stably brought into contact with the contact region SR of the shaft member 40. Thereby, the influence which the shaft member 40 receives from the rolling element 30 can be investigated correctly. Thus, in the fatigue test, the specimen can be easily tested, and the fatigue state of the specimen can be accurately grasped.

<Continuous fatigue test>
In the fatigue test apparatus 1, the fatigue test can be continuously performed using the basic fatigue test described above. For example, when the first fatigue test is executed using the basic fatigue test (S1 to S9), the shaft member 40 is moved in the axial direction in the fatigue test apparatus 1 and mounted again (in S10). Yes). And the 2nd fatigue test is performed (S1-S9). Thus, the contact member SR is formed in one shaft member 40 by moving the shaft member 40 sequentially in the fatigue test apparatus 1 and repeating the fatigue test. Then, when the number of fatigue tests desired by the test performer is completed, the shaft member 40 is removed from the fatigue test apparatus 1 (No in S10).

  Subsequently, the shaft member 40 is cut perpendicular to the shaft core at a position avoiding each contact region SR, that is, in the vicinity of each of the plurality of contact regions SR. Then, each of the plurality of cut surfaces is polished in the direction of the contact region SR. Then, by polishing each cut surface, when each polished surface reaches the contact region SR, the state of each polished surface is observed. Thereby, the result of many fatigue tests can be easily obtained from one shaft member 40. In addition, results obtained when the fatigue test is executed under various conditions can be easily obtained from one shaft member 40.

  Note that the amount of movement when the shaft member 40 is moved in the axial direction is set to be larger than the width of the contact region SR. This movement amount is a movement amount considered so that a certain fatigue test does not affect the next fatigue test. Thereby, even if a plurality of fatigue tests are executed using only one shaft member 40, independent results can be obtained from each of the plurality of fatigue tests.

  Below, an example at the time of performing a fatigue test on different conditions with respect to the one shaft member 40 is shown. For example, when the basic rotation number of the shaft member 40 in the fatigue test is set to “1 × 10 6” times, in the first fatigue test, when the shaft member 40 rotates “1 × 10 6” The rotation of the shaft member 40 is stopped. Subsequently, in the second fatigue test, when the shaft member 40 is moved in the axial direction and the shaft member 40 rotates “2 × 10 6”, the rotation of the shaft member 40 is stopped. Similarly, in the nth fatigue test, when the shaft member 40 is moved in the axial direction and the shaft member 40 rotates “n × 10 6”, the rotation of the shaft member 40 is stopped. Then, n test results, that is, n contact regions SR are formed on the outer peripheral surface of one shaft member 40. The n contact regions SR are formed at different positions from each other.

  Thus, in this fatigue test apparatus 1, it is possible to easily obtain the results of a plurality of fatigue tests under different conditions by moving only one shaft member 40. In addition, since a plurality of fatigue test results can be obtained from one shaft member 40 having the same inclusion distribution, the influence of the inclusions on the fatigue state of the shaft member 40 can be qualitatively grasped. . For example, as shown here, when the number of rotations of the shaft member 40 (“n × 10 6” times) is increased as the number of fatigue tests (n) increases, the nth test from the first fatigue test is performed. Until the fatigue test, the influence that the shaft member 40 receives from the rolling element 30 can be observed in time series. In this case, from the first fatigue test to the nth fatigue test, cracks and the like growing on the shaft member 40 with the inclusion as a base point can be observed in time series.

[Features of this fatigue testing device]
In the fatigue test apparatus 1, the rolling element 30 is rolled by rotating the shaft member 40 while the rolling element 30 supported by the support means 20 is in contact with the shaft member 40. Thereby, in this fatigue test apparatus 1, the influence which the shaft member 40 receives from the rolling element 30, when the rolling element 30 is rolling in the state which contacted the shaft member 40, ie, the fatigue state of the shaft member 40, is investigated. be able to.

  For this reason, in the fatigue test apparatus 1, when the fatigue test is completed, the fatigue state of the shaft member 40 can be directly examined simply by removing the shaft member 40 from the fatigue test apparatus 1. Moreover, in this fatigue test apparatus 1, the influence which the shaft member 40 receives from only one rolling element 30 can be investigated directly. Moreover, in this fatigue test apparatus 1, since the rolling element 30 is supported at four places by the support means 20, the rolling element 30 can be rolled stably.

  In particular, in the fatigue test apparatus 1, since the rolling element 30 is in contact with the outer peripheral surface of the shaft member 40 in a state where the rolling element 30 is supported at four locations by the support means 20, when the shaft member 40 rotates. The rolling element 30 can be reliably brought into contact with the contact region SR of the shaft member 40. That is, the position where the rolling element 30 contacts the shaft member 40, that is, the input position of the stress from the rolling element 30 to the shaft member 40 can be stabilized. Thereby, the influence which the shaft member 40 receives from the rolling element 30 can be investigated correctly. Thus, in the fatigue test apparatus 1, the shaft member 40 can be easily tested, and the fatigue state of the shaft member 40 can be accurately grasped.

  Moreover, in this fatigue test apparatus 1, since the rolling element 30 is pinched | interposed by the shaft member 40 and the support means 20 with which the apparatus main body was mounted | worn, when rotating the shaft member 40, the rolling element 30 is made. In the state where it is in contact with the shaft member 40, it can be stably rolled. For example, even if at least one of the shaft member 40 and the rolling element 30 is worn or deformed, the rolling element 30 can be reliably brought into contact with the shaft member 40 and rolled. Thereby, the influence which the shaft member 40 receives from the rolling element 30 can be investigated more correctly.

  Moreover, in this fatigue test apparatus 1, since the support means 20 is supported so that the rolling element 30 can roll in one direction, the rolling element 30 is made to contact the contact area SR of the shaft member 40 stably. Can do. Thereby, the influence which the shaft member 40 receives from the rolling element 30 can be investigated more correctly.

  In the fatigue test apparatus 1, the rolling elements 30 are supported at four locations by the four rolling element bearings 26. Specifically, the rolling element 30 includes a rotation axis X2 (second rotation axis) of the first bearing 26a for the rolling element and a rotation axis X3 (third rotation axis) of the second bearing 26b for the rolling element. In the meantime, it is supported at four places by bearings 26 for four rolling elements. More specifically, the rolling element 30 has four locations between two bearings arranged coaxially on the second rotating shaft and two other bearings arranged coaxially on the third rotating shaft. Supported by Thereby, the rolling element 30 can be supported stably. Moreover, the rolling element 30 can be smoothly rolled in the direction in which the bearing rotates. Furthermore, the position where the rolling element 30 contacts the shaft member 40, that is, the input position of the stress from the rolling element 30 to the shaft member 40 can be fixed. For this reason, since the influence which the shaft member 40 receives from the rolling element 30 can be investigated with high precision, the fatigue state of the shaft member 40 can be grasped | ascertained correctly.

  Further, in the fatigue test apparatus 1, the shaft member 40 is positioned so as to be rotatable with respect to the support body 21 of the support means 20 by the positioning portion 24 of the support means 20. The positions of the member 40 and the rolling element 30 can be set. Thereby, the positional accuracy of the shaft member 40 and the rolling element 30 can be reliably guaranteed. That is, since the influence which the shaft member 40 receives from the rolling element 30 can be investigated with high accuracy, the fatigue state of the shaft member 40 can be accurately grasped.

[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.
(A) In the said embodiment, although the example in case a test body is the shaft member 40 was shown, it replaced with the shaft member 40 and you may set the rolling element 30 to a test body. In this case, when the rotation of the shaft member 40 reaches a predetermined number of rotations, the rolling element 30 is detached from the fatigue test apparatus 1 and the cut surface of the rolling element 30 is observed. Moreover, you may set the shaft member 40 and the rolling element 30 to a test body. In this case, when the rotation of the shaft member 40 reaches a predetermined number of rotations, the shaft member 40 and the rolling element 30 are removed from the fatigue test apparatus 1, and the cut surfaces of the shaft member 40 and the rolling element 30 are observed. As described above, even if the test object is set to the rolling element 30, or the shaft member 40 and the rolling element 30, the fatigue state of the rolling element 30 affected by the shaft member 40, the rolling element 30 and the shaft member 40, or It is possible to easily reproduce and accurately grasp the fatigue state of the members 40 and 30 when the two influence each other.
(B) In the above-described embodiment, an example in which the rolling element 130 is supported at four locations by the four rolling element bearings 26 is shown. However, the rolling element 130 is supported by the three rolling element bearings 26. You may do it. In this case, in the plan view shown in FIG. 7A, the three rolling element bearings 126 are composed of two rolling element third bearings 126a and 126b having rotating shafts arranged in parallel to each other, and 2 It is comprised from the 4th bearing 126c for one rolling element which has a rotating shaft in the middle of the rotating shaft of the 3rd bearings 126a and 126b for one rolling element. The third bearings 126a and 126b for the rolling elements have the same diameter. In the side view shown in FIG. 7B, the rotation shaft of the fourth bearing 126c for the rolling element is mounted on the plate member 22 so as to incline upward as the distance from the rolling element 130 increases. Even if the fatigue test apparatus is configured in this manner, the same effects as those of the embodiment can be obtained. FIG. 7 is a schematic diagram showing the positional relationship between the rolling element 130 and the three rolling element bearings 126 (126a, 126b, 126c).
(C) In the above-described embodiment, the first bearings 26a for the two rolling elements are arranged coaxially, the second bearings 26b for the two rolling elements are arranged coaxially, and one rolling element 30 has four rolling elements. The example in the case where it is supported at four places by the bearings 26a and 26b for use was shown. Instead, as shown in a plan view of FIG. 8, three fifth bearings 226a for rolling elements are arranged coaxially, and six sixth bearings 226b for three rolling elements are arranged coaxially, and two rolling elements are arranged. The moving body 230 may be supported by six rolling element bearings 226 (226a, 226b). In this case, since two rolling elements 230 can be used simultaneously, two fatigue test results for one shaft member 40 can be obtained simultaneously under the same conditions. In other words, two fatigue test results received by the rolling element 230 from one shaft member 40 can be obtained simultaneously under the same conditions. Even if the fatigue test apparatus is configured in this manner, the same effects as those of the above-described embodiment can be obtained. FIG. 8 is a schematic diagram showing the positional relationship between the two rolling elements 230 and the six rolling element bearings 226 (226a, 226b).

  The present invention can be widely used for a fatigue test apparatus for grasping fatigue of a specimen. Further, the present invention can be widely used for a fatigue test method using the present fatigue test apparatus.

DESCRIPTION OF SYMBOLS 1 Fatigue test apparatus 10 Apparatus main body 13b The 1st bearing 20 for shaft members The support means 24 The positioning part 124b The 2nd bearing 26 for shaft members The bearing 26a for rolling elements The 1st bearing 26b for rolling elements 2nd for rolling elements Bearing 30 Rolling element 40 Shaft member 21 Support body X1 Rotating shaft of shaft member (first rotating shaft)
X2 Rotating shaft of the first bearing for the rolling element (second rotating shaft)
X3 Rotating shaft of the second bearing for rolling elements (third rotating shaft)

Claims (11)

A fatigue testing device for grasping fatigue of a long specimen in one direction,
The device body;
A rolling element that contacts an outer peripheral surface of the test body that is rotatably mounted on the apparatus main body, and rolls according to the rotation of the test body;
A support means provided in the apparatus main body for supporting the rolling elements at at least three locations;
A fatigue test apparatus comprising: The rolling element is sandwiched between the test body and the support means.
The fatigue test apparatus according to claim 1. The support means supports the rolling element so that it can roll in one direction.
The fatigue test apparatus according to claim 1 or 2. The support means has a support body and four bearings mounted on the support body,
The rolling elements are supported at four locations by the four bearings,
The fatigue test apparatus according to any one of claims 1 to 3. Two of the bearings are mounted on the support body so as to be rotatable with respect to a second rotating shaft arranged in parallel with the first rotating shaft of the test body, and the other two bearings are connected to the first rotating shaft. It is attached to the support body so as to be rotatable with respect to a third rotation shaft arranged parallel to the two rotation shafts,
The rolling element is supported at four locations by the four bearings between the second rotating shaft and the third rotating shaft.
The fatigue test apparatus according to claim 4. The support means further includes a positioning portion for positioning the test body rotatably with respect to the support body.
The fatigue test apparatus according to claim 4 and 5. A fatigue test apparatus for grasping fatigue of a spherical specimen,
The device body;
A shaft member rotatably mounted on the apparatus body;
A support means for supporting the test body that contacts the shaft member and rolls according to the rotation of the shaft member at at least three locations;
A fatigue test apparatus comprising: A fatigue test for grasping the fatigue of the first test body that is long in one direction and the fatigue of the spherical second test body that contacts the first test body and rolls according to the rotation of the first test body. A device,
The device body;
A support means provided in the apparatus main body for supporting the second test body in at least three locations;
A fatigue test apparatus comprising: Using an apparatus main body, a shaft member rotatably mounted on the apparatus main body, a rolling element that rolls according to the rotation of the shaft member, and a support means that supports the rolling element at at least three locations, A fatigue test method for grasping fatigue of at least one of the shaft member and the rolling element,
A shaft member mounting step of mounting the shaft member on the apparatus body;
A rolling element arrangement step of arranging the rolling elements on the support means attached to the apparatus body;
A test body setting step of sandwiching the rolling element by the shaft member and the support means;
A test step of rotating the shaft member in a state where the rolling element is sandwiched between the shaft member and the support means;
A fatigue test method comprising: A retesting step of moving and remounting the shaft member relative to the apparatus body,
In addition,
In the test body setting step, the rolling element is sandwiched again by the shaft member after moving and the support means,
In the test step, the shaft member is rotated again in a state where the rolling element is sandwiched by the shaft member after movement and the support means.
The fatigue test method according to claim 9. In the test step, the shaft member is rotated such that the number of rotations of the shaft member before movement differs from the number of rotations of the shaft member after movement.
The fatigue test method according to claim 10.

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