Method for correcting misalignment of vehicle propeller shafts

Abstract

This invention provides a method for correcting misalignment in a vehicle propeller shaft, which can reduce the misalignment between stub shafts pressed into both ends of the propeller shaft body. [Solution] Based on the misalignment direction CH and misalignment amount CD of the stub shaft 16, the corrective pressing position and corrective pressing amount used during misalignment correction are determined. While applying force in the press-fitting direction to the stub shaft 16, the inclination of the stub shaft 16 is forcibly changed in the opposite direction to the misalignment direction CH and so as to eliminate the misalignment amount CD. This corrects the posture of the stub shaft 16, and reduces the misalignment between the stub shafts 16 pressed into both ends of the propeller shaft body 12.

Description

Technical Field

[0001] The present invention relates to a method for correcting the misalignment of a vehicle propeller shaft core.

Background Art

[0002] For example, a vehicle propeller shaft is known which is constituted by press-fitting metal stub shafts at both ends of a propeller shaft body made of a fiber-reinforced resin tube such as CFRP or FRP. For example, the vehicle propeller shaft described in Patent Document 1 is such a shaft.

[0003] By the way, when manufacturing the vehicle propeller shaft described in Patent Document 1, generally, the stub shafts are press-fitted one side of the propeller shaft body at a time. One stub shaft, for example, the front stub shaft, is press-fitted using a front press-fitting machine while centering with reference to a master tube previously attached to the outer peripheral surface of the rear end portion of the propeller shaft body. Then, after pulling out the front press-fitting machine and removing the master tube, the rear stub shaft is press-fitted to the rear side of the propeller shaft body using a rear press-fitting machine while centering with reference to the front stub shaft.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, the alignment standards for pressing in the front stub shaft and the alignment standards for pressing in the rear stub shaft are different. As a result, the stub shaft pressed in later has a larger misalignment than the stub shaft pressed in earlier, and the misalignment between the stub shafts pressed in at both ends of the propeller shaft body increases, which leads to increased vehicle vibration.

[0006] The present invention was made against the above circumstances, and its objective is to provide a method for correcting misalignment of a vehicle propeller shaft that can correct misalignment between stub shafts pressed into both ends of the propeller shaft body. [Means for solving the problem]

[0007] The gist of the first invention is a method for correcting misalignment of a vehicle propeller shaft, in which a metal stub shaft is press-fitted into both ends of a propeller shaft body made of a fiber-reinforced resin tube using a press-fitting jig, the method comprising: (a) a misalignment measurement step of measuring the direction and amount of misalignment of the stub shaft; (c) a correction condition setting step of setting a correction pressing position and correction pressing amount of the stub shaft on the opposite side from the misalignment side for correcting the misalignment of the stub shaft based on the direction and amount of misalignment; and (d) a misalignment correction step of correcting the posture of the stub shaft by pressing the correction pressing position on the opposite side from the misalignment side to forcibly reduce the inclination of the stub shaft so that the amount of misalignment is eliminated.

[0008] The gist of the second invention is that, in the first invention, the correction condition setting step determines the position and thickness of the shim that presses the correction pressing position of the stub shaft when the stub shaft is misaligned, based on the direction and amount of misalignment, and the misalignment correction step corrects the posture of the stub shaft by pressing the press-fitting jig against the correction pressing position between the stub shaft and the press-fitting jig with the shim interposed between them.

[0009] The gist of the third invention is that, in the first invention, the correction condition setting step determines the correction pressing position and the amount of operation in the press-fit direction of the misalignment correction plate on the stub shaft, which presses the correction pressing position on the stub shaft and reduces the inclination of the stub shaft, based on the direction and amount of misalignment of the stub shaft, and the misalignment correction step corrects the posture of the stub shaft by pressing the misalignment correction plate in a direction parallel to the press-fit direction with the amount of operation while the misalignment correction plate is attached to the stub shaft so as to press the correction pressing position on the stub shaft.

[0010] The gist of the fourth invention is that, in the first invention, the misalignment measurement step involves measuring the runout of the tip of the stub shaft while it is supported by a pair of bearings fitted to the base of the stub shaft, which is press-fitted into both ends of the propeller shaft body.

[0011] The gist of the fifth invention is that, in the fourth invention, the misalignment correction step corrects the orientation of the stub shaft when the runout of the tip of the stub shaft measured by the misalignment measurement step exceeds a predetermined standard. [Effects of the Invention]

[0012] According to the first invention's method for correcting misalignment of a vehicle propeller shaft, the corrective pressing position and amount used during misalignment correction are determined based on the direction and amount of misalignment of the stub shaft. By applying a force in the press-fitting direction to the stub shaft and forcibly changing the inclination of the stub shaft in the opposite direction to the misalignment and so as to eliminate the amount of misalignment, the misalignment between the stub shafts press-fitted to both ends of the propeller shaft body can be corrected to a small extent.

[0013] According to the second invention's method for correcting misalignment of a vehicle propeller shaft, in the misalignment correction process, the stub shaft's orientation is corrected by pressing the press-fitting jig against the stub shaft with a shim interposed at the correction pressing position opposite to the misalignment side between the stub shaft and the press-fitting jig. This applies a force in the press-fitting direction to the stub shaft while forcibly reducing the tilt of the stub shaft in the opposite direction to the misalignment direction, so as to eliminate the amount of misalignment.

[0014] According to the third invention's method for correcting misalignment of a vehicle propeller shaft, in the misalignment correction process, the stub shaft's orientation is corrected by attaching a misalignment correction plate to the stub shaft and pressing the misalignment correction plate in a direction parallel to the press-fitting direction. This applies a force in the press-fitting direction to the stub shaft while forcibly reducing the tilt of the stub shaft in the opposite direction to the misalignment direction and eliminating the amount of misalignment.

[0015] According to the fourth invention's method for correcting misalignment of a vehicle propeller shaft, in the misalignment measurement step, the runout of the tip of the stub shaft is measured while the stub shaft is supported via a pair of bearings fitted to the bases of the stub shafts, which are press-fitted into both ends of the propeller shaft body. This corrects the orientation of the stub shaft and reduces the misalignment between the stub shafts press-fitted into both ends of the propeller shaft body.

[0016] According to the fifth invention's method for correcting misalignment of a vehicle propeller shaft, in the misalignment correction step, if the runout of the tip of the stub shaft measured in the misalignment measurement step exceeds a predetermined standard, the posture of the stub shaft is corrected. As a result, the posture of stub shafts whose tip runout exceeds a predetermined standard is corrected. [Brief explanation of the drawing]

[0017] [Figure 1] This diagram illustrates a method for measuring the runout of stub shafts at both ends of a vehicle propeller shaft to which the present invention is applied. [Figure 2] It is a figure explaining a main part of an axial misalignment correction procedure of a vehicle propeller shaft of FIG. 1. [Figure 3] It is a figure explaining a pressing direction and a correction direction of a stub shaft using a press fitting jig in an axial misalignment correction process of FIG. 2. [Figure 4] It is a figure showing an end face of a press fitting jig used in an axial misalignment correction process of FIG. 2. [Figure 5] It is a perspective view showing a correction plate used in an axial misalignment correction process of FIG. 8. [Figure 6] It is a figure explaining a pressing direction and a correction direction of a stub shaft using a correction plate in an axial misalignment correction process of FIG. 8. [Figure 7] It is a figure explaining a pressing state of a stub shaft using a correction plate in an axial misalignment correction process of FIG. 8. [Figure 8] It is a figure explaining a main part of an axial misalignment correction procedure of a vehicle propeller shaft according to another embodiment of the present invention.

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of each part are not necessarily drawn accurately.

Example

[0022] Figure 2 illustrates the essential steps of the procedure for correcting the misalignment of the stub shaft 16 of the propeller shaft 10. In the first misalignment measurement step P1 in Figure 2, the misalignment (runout) of the propeller shaft 10 is measured. Specifically, as shown in Figure 1, the propeller shaft 10 is horizontally supported by a base 32 such as a V-block on a surface plate via a bearing 24. In this state, while manually rotating the propeller shaft 10, the runout of the small-diameter shaft portion 28, which is the tip of the pair of stub shafts 16, is detected by a pair of misalignment sensors 34. The misalignment sensors 34 can be, for example, a contact-type displacement sensor using a differential transformer that is linked to a contactor that is in contact with the small-diameter shaft portion 28, or an optical displacement sensor that measures the displacement of the small-diameter shaft portion 28 based on the reflected light of an irradiated laser beam. The misalignment sensor 34 measures the maximum displacement, i.e., the misalignment amount CD, in the direction perpendicular to the rotational centerline CL of the small-diameter shaft portion 28 of the stub shaft 16, and the misalignment direction CH of the stub shaft 16, which is the measurement position (for example, the contact position) of the misalignment sensor 34 indicating the misalignment amount CD.

[0023] In the first misalignment measurement step P1, it is determined whether the amount of misalignment (runout) CD at the tip of the pair of stub shafts 16 is less than or equal to a predetermined standard value CDA. If this determination is affirmed and the result is within the standard, that is, if the amount of misalignment CD is less than or equal to the standard value CDA, the misalignment of the stub shafts 16 is not corrected. However, if this determination is denied, that is, if the amount of misalignment CD exceeds the standard value CDA, the correction process from the correction condition setting step P2 onwards is initiated.

[0024] In the correction condition setting step P2, based on the misalignment direction CH and misalignment amount CD measured in the first misalignment measurement step P1, the corrective pressing position and corrective pressing amount around the rotational centerline CL of the stub shaft 16 for correcting the misalignment of the stub shaft 16 are set on the opposite side of the misaligned side of the stub shaft 16. In the correction condition setting step P2, based on the measured misalignment direction CH and misalignment amount CD, the position and thickness of the shim 40 that presses the corrective pressing position around the rotational centerline CL of the stub shaft 16 when correcting the misalignment of the stub shaft 16 are determined. For example, if the maximum value of the misalignment amount CD of the stub shaft 16 is on the upper side of Figure 3, the misalignment direction CH is on the upper side of Figure 3, and the corrective pressing position is set on the lower side of the flange portion 20 of the stub shaft 16 in Figure 3. As shown in Figure 4, a pair of shims 40 are attached so that pressing force is applied to the corrective pressing position that corrects the misalignment among the annular pressing surfaces 44 of the press-fitting jig 42 that face the flange portion 20. Furthermore, after corrective pressing, the thickness of the shim 40 corresponding to the corrective pressing amount is selected based on the relationship between the misalignment amount CD and the corrective pressing amount, which has been experimentally determined in advance, so that the measured misalignment amount CD is eliminated. This relationship is selected based on the actual material strength of the propeller shaft body 12 and the number of corrective pressings, from among several relationships set for each material strength of the propeller shaft body 12 and the number of corrective pressings.

[0025] In the misalignment correction process P3 using the shim 40, the press-fitting jig 42 is pressed in the direction indicated by arrow A in Figure 3, and the stub shaft 16 is pressed in that direction. At this time, a pair of shims 40 are interposed between the stub shaft 16 and the annular pressing surface 44 of the press-fitting jig 42, so with point P as the pivot point, the stub shaft 16, which is pressed into the propeller shaft body 12, is corrected to the opposite direction B from the misaligned side, and the amount of misalignment CD is reduced. When the amount of misalignment CD becomes zero, the center line of the stub shaft 16 is brought to approximately coincide with the rotational center line CL of the propeller shaft 10, i.e., the propeller shaft body 12.

[0026] Next, in the second misalignment measurement step P4, it is determined whether the amount of misalignment (runout) CD at the tip of the stub shaft 16 after correction is less than or equal to the predetermined standard value CDA. If this determination is affirmative, that is, if the amount of misalignment CD is less than or equal to the standard value CDA, the misalignment of the stub shaft 16 is not corrected. However, if this determination is negative, that is, if the amount of misalignment CD exceeds the standard value CDA, the correction process from the correction condition setting step P2 onwards is restarted.

[0027] As described above, according to the propeller shaft 10 misalignment correction method of this embodiment, the correction pressing position and correction pressing amount used during misalignment correction are determined based on the misalignment direction CH and misalignment amount CD of the stub shaft 16. By applying a force in the press-fitting direction to the stub shaft 16 and forcibly changing the inclination of the stub shaft 16 in the opposite direction to the misalignment direction CH and so as to eliminate the misalignment amount CD, the posture of the stub shaft 16 is corrected, and the misalignment between the stub shafts 16 pressed into both ends of the propeller shaft body 12 is corrected to a small extent.

[0028] Furthermore, according to the propeller shaft 10 misalignment correction method of this embodiment, in the misalignment correction step P3, the stub shaft 16 is corrected by pressing the press-fitting jig 42 with a shim 40 interposed between the stub shaft 16 and the press-fitting jig 42 at the correction pressing position on the opposite side of the misalignment. As a result, while applying force in the press-fitting direction to the stub shaft 16, the tilt of the stub shaft 16 is forcibly reduced in the opposite direction of the misalignment CH and the amount of misalignment CD is eliminated.

[0029] Furthermore, according to the propeller shaft 10 misalignment correction method of this embodiment, in the first misalignment measurement step P1, the amount of misalignment (runout) CD of the tip of the stub shaft 16 is measured while it is supported by a pair of bearings 24 fitted to the bases of the stub shafts 16 which are press-fitted into both ends of the propeller shaft body 12. This corrects the posture of the stub shaft 16 and reduces the misalignment between the stub shafts 16 press-fitted into both ends of the propeller shaft body 12.

[0030] Furthermore, according to the propeller shaft 10 misalignment correction method of this embodiment, in the first misalignment correction step P3, if the amount of misalignment (runout) CD at the tip of the stub shaft 16 measured in the first misalignment measurement step P1 exceeds a predetermined judgment value CDA that satisfies a set standard, the posture of the stub shaft 16 is corrected. As a result, the posture of the stub shaft 16 whose amount of misalignment (runout) CD at the tip exceeds the predetermined judgment value CDA is corrected. [Examples]

[0031] Next, other embodiments of the present invention will be described with reference to Figures 5 to 8. In this embodiment, parts common to the previously described embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0032] In this embodiment of the propeller shaft 10 misalignment correction method, the orientation of the stub shaft 16 is corrected using the misalignment correction plate 50 shown in Figure 5. The misalignment correction plate 50 is rectangular in shape and has a pair of parallel legs 54 that straddle the large-diameter shaft portion 22 of the stub shaft 16 by forming a U-shaped notch 52 in the center of one side, and a flat pressing portion 56 from the other side parallel to the one side to the notch 52. The pressing portion 56 and the legs 54 are parallel to each other, but the pressing portion 56 is offset towards the flange portion 20 side, and the legs 54 are offset towards the bearing fitting portion 26 side. As a result, as shown in Figure 6, the pressing portion 56 is in contact with the flange portion 20 and the legs 54 are in contact with the bearing fitting portion 26, and the orientation of the stub shaft 16 is corrected by pressing the pressing portion 56 of the misalignment correction plate 50 toward the propeller shaft body 12 side using the press-fitting device 58 shown in Figure 7.

[0033] In Figure 7, the press-fitting device 58 has stub shafts 16 press-fitted into both ends of the propeller shaft body 12, but it is also used to correct the misalignment of the stub shafts 16 using the misalignment correction plate 50. The press-fitting device 58 comprises a fixed-side jig 60 that receives the stub shaft 16 at one end of the propeller shaft 10, and a movable-side jig 62 that receives the stub shaft 16 at the other end of the propeller shaft 10 and applies axial pressure to the stub shaft 16 at the other end. When correcting misalignment, the movable-side jig 62 does not contact the stub shaft 16 at the other end, and a pressing member 64 that presses the pressing portion 56 of the misalignment correction plate 50 is provided on the movable-side jig 62. The corrective pressing amount, which will be described later, is applied from the movable-side jig 62 to the pressing portion 56 of the misalignment correction plate 50.

[0034] Figure 8 illustrates the essential steps of the procedure for correcting the misalignment of the stub shaft 16 of the propeller shaft 10 using the misalignment correction plate 50. In the first misalignment measurement step P11 in Figure 8, similar to the first misalignment measurement step P1 in Figure 2, the maximum displacement in the direction perpendicular to the rotational centerline CL of the small-diameter shaft portion 28 of the stub shaft 16, i.e., the misalignment amount CD, and the misalignment direction CH of the stub shaft 16, which is the measurement position (e.g., contact position) of the misalignment sensor 34 indicating the misalignment amount CD, are measured. In addition, in the first misalignment measurement step P11, it is determined whether the misalignment amount (runout) CD of the tip portions of the pair of stub shafts 16 is less than or equal to a predetermined standard value CDA. If this determination is within the standard, i.e., if the misalignment amount CD is less than or equal to the standard value CDA, the misalignment of the stub shaft 16 is not corrected. However, if this determination is rejected, that is, if the misalignment amount CD exceeds the determination value CDA and is therefore out of specification, the correction process P12 and subsequent steps are initiated.

[0035] In the correction condition setting step P12, based on the misalignment direction CH and misalignment amount CD measured in the first misalignment measurement step P11, the corrective pressing position and corrective pressing amount around the rotational centerline CL of the stub shaft 16 for correcting the misalignment of the stub shaft 16 are set on the opposite side of the misaligned side of the stub shaft 16. In the correction condition setting step P12, based on the measured misalignment direction CH and misalignment amount CD, the position of the pressing portion 56 of the misalignment correction plate 50 that presses the corrective pressing position of the stub shaft 16 when correcting the misalignment of the stub shaft 16, and the amount of operation in the press-fit direction of the pressing portion 56 of the misalignment correction plate 50 are determined. For example, if the misalignment direction CH of the stub shaft 16 is towards the lower side in Figure 6, the corrective pressing position is determined on the upper side of the flange portion 20 of the stub shaft 16 in Figure 6, and as shown in Figure 6, the misalignment correction plate 50 is attached so that pressing force is applied from the pressing portion 56 of the misalignment correction plate 50 to the corrective pressing position that corrects the misalignment CD. Furthermore, after corrective pressing, the corrective pressing amount of the misalignment correction plate 50 is set based on the relationship between the misalignment amount CD and the corrective pressing amount of the misalignment correction plate 50, which has been experimentally determined in advance, so that the measured misalignment amount CD is eliminated. This relationship is also selected based on the actual material strength of the propeller shaft body 12 and the number of corrections, from among multiple relationships set for each material strength of the propeller shaft body 12 and each number of corrections.

[0036] In the misalignment correction process P13 using the misalignment correction plate 50, the pressing portion 56 of the misalignment correction plate 50 is pressed in the direction of the press-fitting direction of the stub shaft 16 by the press-fitting device 58 in the direction indicated by arrow C in Figure 6. At this time, the pressing portion 56 of the misalignment correction plate 50 is in contact with the flange portion 20 and the leg portion 54 is in contact with the bearing fitting portion 26. Therefore, by the principle of leverage, with point P as the pivot point, the stub shaft 16 is corrected to the opposite direction B from the misaligned side, and the center line of the stub shaft 16 is brought to approximately coincide with the rotational center line CL of the propeller shaft 10, i.e., the propeller shaft body 12.

[0037] Next, in the second misalignment measurement step P14, it is determined whether the amount of misalignment (runout) CD at the tip of the stub shaft 16 after correction is less than or equal to the predetermined standard value CDA. If this determination is affirmative, that is, if the amount of misalignment CD is less than or equal to the standard value CDA, the misalignment of the stub shaft 16 is not corrected. However, if this determination is negative, that is, if the amount of misalignment CD exceeds the standard value CDA, the correction process from the correction condition setting step P12 onwards is restarted.

[0038] According to the propeller shaft 10 misalignment correction method of this embodiment, the correction pressing position and correction pressing amount around the rotation centerline CL of the misalignment correction plate 50 used during misalignment correction are determined based on the misalignment direction CH and misalignment amount CD of the stub shaft 16. While applying a force in the press-fitting direction to the stub shaft 16, the inclination of the stub shaft 16 is forcibly reduced in the opposite direction to the misalignment direction CH and so as to eliminate the misalignment amount CD. This corrects the posture of the stub shaft 16, and reduces the misalignment between the stub shafts 16 that are press-fitted into both ends of the propeller shaft body 12.

[0039] Furthermore, according to the propeller shaft 10 misalignment correction method of this embodiment, in the misalignment correction step P13, the posture of the stub shaft 16 is corrected by attaching the misalignment correction plate 50, which reduces the inclination of the stub shaft 16, to the stub shaft 16 and pressing the misalignment correction plate 50 in a direction parallel to the press-fitting direction. As a result, while applying force in the press-fitting direction to the stub shaft 16, the inclination of the stub shaft 16 is forcibly reduced in the opposite direction to the misalignment direction CH and so as to eliminate the misalignment amount CD.

[0040] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be implemented in other embodiments.

[0041] For example, although the propeller shaft body 12 in the above-described embodiment was a cylindrical body made of fiber-reinforced resin tubing, it may also be a cylindrical body made of metal into which the stub shaft 16 can be press-fitted.

[0042] Furthermore, in Figure 4, instead of the pair of shims 40, a single longitudinal shim connecting the pair of shims 40 may be used.

[0043] The above is merely one embodiment, and although we will not provide further examples, the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, without departing from its spirit. [Explanation of Symbols]

[0044] 10: Propeller shaft (vehicle propeller shaft), 12: Propeller shaft body, 16: Stub shaft, 24: Ball bearing (bearing), 40: Shim, 42: Press-fit jig, 50: Misalignment correction plate, CH: Misalignment direction, CD: Misalignment amount (runout), CDA: Judgment value

Claims

1. A method for correcting misalignment of a vehicle propeller shaft, in which metal stub shafts are press-fitted into both ends of a propeller shaft body made of fiber-reinforced resin tubing using a press-fitting jig, A misalignment measurement step for measuring the direction and amount of misalignment of the stub shaft, Based on the aforementioned misalignment direction and amount, a correction condition setting step is performed to set the correction pressing position and correction pressing amount of the stub shaft for correcting the misalignment of the stub shaft on the opposite side from the misalignment side. The process includes correcting the orientation of the stub shaft by pressing the corrective pressing position on the opposite side of the misalignment to forcibly reduce the inclination of the stub shaft so that the amount of misalignment is eliminated. A method for correcting misalignment of a vehicle propeller shaft, characterized by the following:

2. The correction condition setting step determines, based on the direction and amount of misalignment, the position and thickness of the shim that presses the correction pressing position of the stub shaft when correcting the misalignment of the stub shaft. The aforementioned misalignment correction process corrects the orientation of the stub shaft by pressing the press-fitting jig against the corrective pressing position between the stub shaft and the press-fitting jig with the shim interposed between them. The method for correcting misalignment of a vehicle propeller shaft according to feature 1.

3. The correction condition setting step determines, based on the misalignment direction and amount of misalignment, the amount of operation of the misalignment correction plate that presses the correction pressing position of the stub shaft and reduces the inclination of the stub shaft when correcting the misalignment of the stub shaft, the correction pressing position of the stub shaft and the amount of operation in the press-fit direction of the stub shaft, The aforementioned misalignment correction process involves attaching the misalignment correction plate to the stub shaft so as to press the corrective pressing position on the stub shaft, and then pressing the misalignment correction plate in a direction parallel to the press-fitting direction with the aforementioned operating amount to correct the orientation of the stub shaft. The method for correcting misalignment of a vehicle propeller shaft according to feature 1.

4. The aforementioned misalignment measurement step involves measuring the runout of the tip of the stub shaft while it is supported by a pair of bearings fitted to the base of the stub shaft, which is press-fitted into both ends of the propeller shaft body. The method for correcting misalignment of a vehicle propeller shaft according to feature 1.

5. The aforementioned misalignment correction step corrects the orientation of the stub shaft when the runout of the tip of the stub shaft measured in the aforementioned misalignment measurement step exceeds a predetermined standard value. The method for correcting misalignment of a vehicle propeller shaft according to feature 4.

Images