JP2015194386A - Rotating bending fatigue characteristic evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely evaluate a bending characteristic of repetition accompanied by the rotation of a shaft-shaped part such as a shaft with a sheave.SOLUTION: This rotating bending fatigue characteristic evaluation device 10 comprises: both-end support parts 11, 12 which rotationally support longitudinal both end parts of a shaft-shaped part 1 being an object to be evaluated; a bending load imparting part 13 which imparts a bending load F to the shaft-shaped part 1; a rotation drive part 14 which rotationally drives the shaft-shaped part 1; and an intermediate support part 15 which rotationally supports a longitudinal intermediate region 2a being an operation position of the bending load F out of a shaft part 2 of the shaft-shaped part 1. Then, the bending load F from the bending load imparting part 13 is imparted to the intermediate region 2a of the shaft part 2 via the intermediate support part 15.

Description

  The present invention relates to a rotary bending fatigue characteristic evaluation apparatus, and more particularly, to a rotary bending fatigue characteristic evaluation apparatus that uses a shaft-like component such as a shaft with a sheave as an evaluation target.

  For example, a shaft with a sheave used in a CVT (continuously variable transmission) has been conventionally subjected to a (static) bending test of the shaft with a sheave to evaluate its bending characteristics. . On the other hand, recently, there is a demand for evaluating mechanical characteristics under conditions closer to those during use (actual operation), that is, repeated bending characteristics during rotation.

  Here, for example, in Patent Document 1, a chuck is provided at one end (the end close to each other) of two shaft-shaped jigs rotatably supported in a pair of shaft cases. While holding the rod-shaped test piece, connect the load rod to a predetermined position on each shaft-shaped jig and attach a weight to the lower end of the load rod to apply a bending load to the predetermined position. Thus, a bending moment according to the weight of the weight can be applied to the test piece held between the shaft-shaped jigs, and by rotating the motor connected to the other end of the shaft-shaped jig, A rotary bending tester capable of rotating a test piece held on a shaft-like jig is disclosed.

JP 2010-133759 A

  However, in the testing machine described in Patent Document 1, the position of the bending load is further on the outside in the longitudinal direction than the both ends in the longitudinal direction of the test piece (position far away from the test piece in the longitudinal direction). Therefore, even if this testing machine is used as it is for a shaft with a sheave, the load condition of the shaft with a sheave during actual use is far from the actual load condition, and repeated bending characteristics with rotation of the shaft with a sheave are accurately evaluated. It doesn't mean that

  In view of the above circumstances, the problem to be solved by the present invention is to accurately evaluate repeated bending characteristics accompanying rotation of a shaft-like component such as a shaft with sheave.

  The solution to the above-described problem is achieved by the rotating bending fatigue characteristic evaluation apparatus for a shaft with sheave according to the present invention. That is, this evaluation apparatus includes both end support portions that rotate and support both longitudinal ends of a shaft-shaped component to be evaluated, a bending load applying portion that applies a bending load to the shaft-shaped component, and a shaft-shaped component. A rotation drive unit for rotational driving, and an intermediate support unit for rotating and supporting a longitudinal intermediate region serving as a bending load acting position in the shaft portion of the shaft-like component, and the intermediate region of the shaft unit via the intermediate support unit Characterized by a point configured to apply a bending load from the bending load applying unit.

  The conventional testing machine as described in Patent Document 1 usually performs a rotary bending test in order to evaluate the bending characteristics of a specific material (metal, etc.), and sets the load condition based on the bending moment. It is common to do. Therefore, setting the bending moment is facilitated by placing a sufficient distance from the maximum bending deformation position and placing the point of application of the bending load at a position far away from the test piece. On the other hand, the evaluation apparatus according to the present invention is configured to evaluate the rotational bending fatigue characteristics under load conditions during actual use of the shaft-like component. In other words, taking a shaft with a CVT sheave as an example, this type of shaft-shaped component has a power transmission belt spanned between a fixed sheave integrated with the shaft portion and a movable sheave formed separately. A load having a magnitude corresponding to the tension of the power transmission belt acts in the direction of bending the shaft portion. Therefore, the size reflecting the tension of the power transmission belt by adopting a form in which the bending load is applied to the portion (intermediate region) where the bending load from the power transmission belt acts on the shaft portion via the intermediate support portion. It is possible to reproduce the load conditions during actual operation based on the bending load as accurately as possible. Accordingly, it is possible to evaluate the accurate rotational bending fatigue characteristics of the shaft-like component.

  Further, the evaluation device according to the present invention includes a bearing portion in which the intermediate support portion includes an inner ring and an outer ring, and rolling elements disposed between the inner ring and the outer ring, and an inner ring and a shaft portion of the bearing portion. A connecting portion that connects the intermediate region, a bending load from the bending load applying portion is applied to the outer ring of the bearing portion, and the connecting portion projects from the inner diameter side and the outer diameter side of the shaft portion. It may be configured to connect the intermediate region and the inner ring of the bearing portion.

  With such a configuration, the shaft-like component to be evaluated is held concentrically without rattling with respect to the bearing portion of the intermediate support portion while being rotatably supported. Therefore, when a bending load that passes through the central axis of the shaft portion and is orthogonal to the intermediate region of the shaft portion is applied to the intermediate region of the shaft portion via the outer ring, the situation where the shaft portion hits the inner ring of the bearing portion is avoided. Thus, wear of the shaft portion and the inner ring can be prevented. Therefore, it is possible to accurately evaluate the characteristics against repeated bending by eliminating the influence of deterioration due to wear. In addition, since it is possible to avoid a situation in which the bending load is concentrated only on the rolling elements through which the line of action of the bending load passes, it is possible to avoid increasing the size of the rolling elements to be used, the bearing portion including the rolling element, and consequently the intermediate support portion. it can. Therefore, for example, in the case of a shaft with a sheave, the shaft portion can be supported at a position as close as possible to the sheave portion, and evaluation under conditions closer to actual operation becomes possible.

  As described above, according to the present invention, it is possible to accurately evaluate repeated bending characteristics accompanying rotation of a shaft-like component such as a shaft with sheave.

It is a front view which shows the whole structure of the rotating bending fatigue characteristic evaluation apparatus which concerns on one Embodiment of this invention. It is sectional drawing to which the principal part of the evaluation apparatus shown in FIG. 1 was expanded. It is the principal part side view which looked at the intermediate support part from the slide direction.

  Hereinafter, a rotary bending fatigue characteristic evaluation apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a case where a shaft with a sheave having a fixed sheave incorporated in a continuously variable transmission (CVT) of an automobile is an object to be evaluated will be described as an example.

  FIG. 1 shows the overall configuration of a rotating bending fatigue characteristic evaluation apparatus according to an embodiment of the present invention. As shown in FIG. 1, this rotating bending fatigue property evaluation apparatus 10 rotates both ends in the longitudinal direction of a shaft 1 with a sheave as a shaft-like component to be evaluated (shown by a one-dot chain line in FIG. 1). The both-ends support parts 11 and 12 to support, the bending load provision part 13 which gives a bending load with respect to the shaft 1 with a sheave, the rotational drive part 14 which rotationally drives the shaft 1 with a sheave, and the shaft 1 with a sheave are comprised. An intermediate support portion 15 that rotationally supports an intermediate region 2a in the longitudinal direction serving as a bending load acting position in the shaft portion 2 is provided.

  In this embodiment, the rotating bending fatigue characteristic evaluation apparatus 10 includes at least one of the both end support portions 11 and 12 on the support base 16 (one end support portion 11 on the side far from the rotation drive portion 14 in this embodiment), and A slide mechanism 17 that enables the intermediate support portion 15 to slide is further provided. In this case, the slide mechanism 17 is attached below the guide rails 18 (two in this embodiment) disposed on the support base 16, the one end support portion 11, and the intermediate support portion 15. It comprises a plurality of slide parts 19 and 20 that enable relative movement. Thereby, the distance between the both end support parts 11 and 12 or the distance between the both end support parts 11 and 12 and the intermediate support part 15 can be adjusted.

  As shown in FIG. 2, both end support portions 11 and 12 have bearing portions 21 and 22 and connecting portions 23 and 24 that connect the bearing portions 21 and 22 and the shaft portion 2 of the shaft 1 with sheave. . In the present embodiment, the outer ring 21 a of the bearing portion 21 of the one end support portion 11 is connected to the slide portion 19 via the outer frame 25. A first adapter portion 26 is attached to one end portion in the longitudinal direction of the shaft portion 2 so as to cover the one end portion, and the adapter portion 26 and the inner ring 21b of the bearing portion 21 are connected via the connecting portion 23. Are connected. Similarly, the outer ring 22 a of the bearing portion 22 of the other end support portion 12 is fixed to the support base 16 via the outer frame 27. A second adapter portion 28 is attached to the other end portion in the longitudinal direction of the shaft portion 2 so as to cover the other end portion, and the adapter portion 28 and the inner ring 22b of the bearing portion 22 are connected to the connecting portion 24. It is connected through.

  The intermediate support portion 15 includes a bearing portion 29 and a connecting portion 30 that connects the bearing portion 29 and the shaft portion 2. In the present embodiment, the outer ring 29 a of the bearing portion 29 of the intermediate support portion 15 is connected to the slide portion 20 via the outer frame 31. A third adapter part 32 is attached to the inner periphery of the inner ring 29 b of the bearing part 29, and the adapter part 32 and the shaft part 2 are connected via a connecting part 30. In addition, as long as the 3rd adapter part 32 and the shaft part 2 can be connected, the connection part 30 can employ | adopt arbitrary connection means, for example, the wedge action of the taper surface accompanying tightening of a clamping bolt. Thus, it is possible to employ a lock mechanism having a structure in which the inner peripheral surface is reduced in diameter and the outer peripheral surface is increased in diameter. Of course, a locking mechanism having a similar structure can be adopted for the connecting portions 23 and 24 of the both end support portions 11 and 12.

  Further, a connecting rod 33 that connects the outer frame 31 and the bending load applying portion 13 so as to be able to transmit power is connected to the lower portion 31a of the outer frame 31 of the intermediate support portion 15, and is constituted by a hydraulic cylinder, for example. The bending load applying portion 13 can be slid integrally with the intermediate support portion 15, and the bending load F from the bending load applying portion 13 can be transmitted to the outer frame 31. In the present embodiment, as shown in FIGS. 2 and 3, the bending load F is applied in a direction along the connecting rod 33 extending vertically downward from the lower portion of the outer frame 31, so that the center line of the shaft portion 2 is set. A bending load F that is directed vertically downward is configured to act on the shaft portion 2.

  Further, in the present embodiment, as shown in FIG. 1, a load measuring unit 34 such as a load cell that measures the magnitude of the bending load F is provided between the connecting rod 33 and the bending load applying unit 13. The magnitude of the bending load F applied to the shaft portion 2 from the load applying portion 13 can be measured at any time.

  Next, an example of operation | movement of the rotating bending fatigue characteristic evaluation apparatus 10 of the said structure is demonstrated.

  First, the shaft portion 2 of the shaft 1 with sheave is inserted into the inner periphery of the intermediate support portion 15 in which the third adapter portion 32 and the connecting portion 30 are attached to the inner periphery of the bearing portion 29. Then, by operating the connecting portion 30 (clamping a clamping bolt, etc.), the connecting portion 30 is projected to the inner diameter side and the outer diameter side, and the shaft portion 2 and the third adapter portion 32 are connected to each other. To do. At this time, the insertion position of the shaft portion 2 is set in consideration of the operation position of the bending load F by the bending load applying portion 13, so that the connecting portion 30 and the third portion are connected to a predetermined intermediate region 2 a of the shaft portion 2. The adapter part 32 is positioned and fixed. In the present embodiment, a region having a certain longitudinal dimension that is very close to the inner diameter side end portion of the sheave surface 3a of the fixed sheave 3 in the shaft portion 2 is set as the intermediate region 2a.

  Next, the intermediate support portion 15 in a state where the shaft portion 2 is connected is slid, and the other end portion in the longitudinal direction of the shaft portion 2 is attached to the second adapter portion 28, and thereafter, the connecting portion 24 is operated. As a result, the second adapter portion 28 and the inner ring 22 b of the bearing portion 22 of the other end support portion 12 are connected via the connecting portion 24.

  Finally, the one end support portion 11 is slid, and the first adapter portion 26 is attached to one end portion in the longitudinal direction of the shaft portion 2 connected to the other end support portion 12 and the intermediate support portion 15. By operating the connecting portion 23, the first adapter portion 26 and the inner ring 21 b of the bearing portion 21 of the one end support portion 11 are connected via the connecting portion 23. With the above operation, the shaft portion 2 of the shaft with sheave 1 is in a state of being rotatably supported by both end support portions 11 and 12 and the intermediate support portion 15.

  When the shaft 1 with sheave is thus rotationally supported, the rotational drive unit 14 is rotationally driven to rotate the second adapter unit 28 connected to the rotational drive unit 14, and the sheave attached to the second adapter unit 28. The attached shaft 1 is rotated at a predetermined rotational speed. At the same time, the bending load applying unit 13 applies a bending load F directed vertically downward to the connecting rod 33. As a result, the outer frame 31 of the intermediate support portion 15 connected to the connecting rod 33 receives a bending load F in the vertically downward direction, and the outer ring 29a of the bearing portion 29 attached to the outer frame 31 and the rolling element 29c. A bending load F directed vertically downward acts on the inner ring 29b. As a result, a bending load F directed vertically downward is applied to the intermediate region 2 a of the shaft portion 2 connected to the inner ring 29 b via the connecting portion 30. In this manner, a predetermined bending load can be applied while rotating the shaft with sheave 1 at a predetermined rotation speed.

  As described above, a state in which a constant rotational speed and a constant bending load are applied is maintained, and repeated bending deformation is caused in the intermediate region 2a of the shaft 1 with the sheave. Then, after a lapse of a predetermined time, the rotational bending fatigue characteristics are evaluated by ascertaining whether or not the shaft with sheave 1 is broken.

  As described above, in the present invention, in addition to the both end support portions 11 and 12, the intermediate support portion 15 that rotatably supports the longitudinal intermediate region 2a serving as the acting position of the bending load F in the shaft portion 2 of the shaft 1 with the sheave. Further, since the bending load F is applied from the bending load applying part 13 to the intermediate region 2a of the shaft part 2 via the intermediate support part 15, the power of the shaft part 2 is provided via the intermediate support part 15. A form in which the bending load F is applied to a portion (intermediate region 2a) where the bending load F from the transmission belt acts can be employed. Therefore, the load condition during actual operation based on the bending load F having a magnitude reflecting the tension of the power transmission belt can be reproduced as accurately as possible. Therefore, it is possible to evaluate the accurate rotational bending fatigue characteristics of the shaft with sheave 1.

  Although one embodiment of the present invention has been described above, the evaluation apparatus according to the present invention is not limited to the above-described exemplary form, and can naturally take any form within the scope of the present invention.

  For example, in the above-described embodiment, the case where the shaft 1 with a CVT sheave is set as an object (evaluation target) of rotational bending fatigue characteristic evaluation is, of course, other shaft-like parts such as a drive shaft It is good also considering the rotating component for motor vehicles as evaluation object. At this time, as in the above-described embodiment, the one-end support portion 11 and the intermediate support portion 15 are configured to be slidable (in other words, close to or away from) the other-end support portion 12, so that the shaft-like component can be easily obtained. Can be supported in rotation.

  Of course, other specific forms can be adopted for matters other than the above as long as the technical significance of the present invention is not lost.

DESCRIPTION OF SYMBOLS 1 Shaft with sheave 2 Shaft part 2a Middle area 3 Fixed sheave 3a Sheave surface 10 Rotating bending fatigue characteristic evaluation apparatus 11 One end support part 12 Other end support part 13 Bending load application part 14 Rotation drive part 15 Intermediate support part 16 Support base 17 Slide Mechanism 18 Guide rail 19, 20 Slide part 21, 22, 29 Bearing part 23, 24, 30 Connecting part 25, 27, 31 Outer frame 26, 28, 32 Adapter part 33 Connecting rod 34 Load measuring part F Bending load

Claims (2)

Both end support portions that rotationally support both longitudinal ends of the shaft-shaped component to be evaluated, a bending load applying portion that applies a bending load to the shaft-shaped component, and a rotational drive that rotationally drives the shaft-shaped component. And an intermediate support portion that rotationally supports a longitudinal intermediate region that serves as an action position of the bending load among the shaft portions of the shaft-shaped component,
A rotary bending fatigue characteristic evaluation device, wherein the bending load is applied from the bending load applying unit to an intermediate region of the shaft portion via the intermediate support unit. The intermediate support portion connects a bearing portion including an inner ring and an outer ring, and a rolling element disposed between the inner ring and the outer ring, and an inner region of the bearing portion and an intermediate region of the shaft portion. And a connecting part
While the bending load from the bending load application portion is applied to the outer ring of the bearing portion,
The rotating bending fatigue characteristic evaluation apparatus according to claim 1, wherein the connecting portion is configured to connect an intermediate region of the shaft portion and an inner ring of the bearing portion by projecting to an inner diameter side and an outer diameter side.

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