Power transmission shaft and transmission shaft

Abstract

A power transmission shaft (PS1), which is a power transmission shaft of the present invention, is set such that a first crushing length (S1) of a first joint member (J1) that bends on the basis of a first bending load is longer than a second crushing length (S2) of a second joint member (J2) that bends on the basis of a second bending load that is larger than the first bending load. Thus, even when an axial load acts from the first end (11) side, the second end (12) side, or both sides of the first end (11) and the second end (12), the second joint member (J2) can smoothly enter the inside of the tube (1), and the impact performance of the propeller shaft (PS1) can be stabilized.

Description

Technical Field

[0001] The invention relates to a power transmission shaft and a drive shaft. Background Art

[0002] As a conventional propeller shaft serving as a power transmission shaft, for example, a propeller shaft described in Patent Document 1 below is known.

[0003] Briefly, the propeller shaft as the power transmission shaft has a first shaft portion connected to a relatively easy-to-bend constant velocity joint press-fitted into a first end portion of a tube, and a second shaft portion connected to a relatively hard-to-bend rubber coupling press-fitted into a second end portion of the tube.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: (Japanese) Patent Publication No. 2021-138203 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] However, in the above-mentioned conventional transmission shaft, the length of the first shaft portion connected to the constant velocity joint that is easy to bend and inserted into the tube (first crush length) and the length of the second shaft portion connected to the rubber coupling that is difficult to bend and inserted into the tube (second crush length) are not considered at all. Therefore, there is room for improvement in that the collision performance of the transmission shaft becomes unstable.

[0009] Therefore, the present invention has been made in view of the above-mentioned technical problems of the conventional propeller shaft, and an object of the present invention is to provide a power transmission shaft and a propeller shaft capable of improving the stability of collision performance.

[0010] Technical solutions for solving technical problems

[0011] As one embodiment of the present invention, a first crush length of the first shaft portion of the first joint component that can bend under a first buckling load and enter the inner circumference of the tube is set to be longer than a second crush length of the second shaft portion of the second joint component that has a buckling load greater than the first buckling load and enters the inner circumference of the tube.

[0012] Effects of the Invention

[0013] According to the present invention, the stability of collision performance can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a layout diagram showing the arrangement of the power transmission shaft (propeller shaft) of the present invention in a vehicle.

[0015] Figure 2It is a half longitudinal sectional view showing the entire power transmission shaft (propeller shaft) according to the first embodiment of the present invention.

[0016] Figure 3 It means from the front Figure 2 The semi-longitudinal cross-sectional views of the power transmission shaft (drive shaft) shown in the state where a collision load is input, (a) is a view showing a state where no crushing occurs, (b) is a view showing a state where a crushing occurs on the first end side of the tube, and (c) is a view showing a state where a crushing occurs on the second end side of the tube.

[0017] Figure 4 It means from the rear Figure 2 The semi-longitudinal cross-sectional views of the power transmission shaft (drive shaft) shown in the state where a collision load is input, (a) is a view showing a state where no crushing occurs, (b) is a view showing a state where crushing occurs on the second end side of the tube, and (c) is a view showing a state where crushing occurs on the first end side of the tube.

[0018] Figure 5 It means from the front to the back Figure 2 The semi-longitudinal cross-sectional view of the power transmission shaft (drive shaft) shown in the state where a collision load is input, (a) is a diagram showing a state where no crushing occurs, and (b) is a diagram showing a state where crushing occurs on the first end side and the second end side of the tube.

[0019] Figure 6 It is a schematic diagram for explaining the effect of the present invention when crushing occurs from the first end side, (a) is a diagram showing the crushed state of the power transmission shaft (drive shaft) of the present invention, and (b) is a diagram showing the crushed state of the conventional power transmission shaft (drive shaft).

[0020] Figure 7 It is a schematic diagram for explaining the effect of the present invention when crushing occurs from the second end side, (a) is a diagram showing the crushed state of the power transmission shaft (drive shaft) of the present invention, and (b) is a diagram showing the crushed state of the conventional power transmission shaft (drive shaft).

[0021] Figure 8 It is a schematic diagram for explaining the effect of the present invention when compression occurs on both sides of the first end and the second end, (a) is a diagram showing the compressed state of the power transmission shaft (drive shaft) of the present invention, and (b) is a diagram showing the compressed state of the conventional power transmission shaft (drive shaft).

[0022] Fig. 9 It is a half longitudinal sectional view showing the whole of a power transmission shaft (propeller shaft) according to a second embodiment of the present invention.

[0023] Fig.10It is a half longitudinal sectional view showing the whole of a power transmission shaft (propeller shaft) according to a third embodiment of the present invention.

[0024] Fig.11 This is a layout diagram showing another example of the arrangement of the power transmission shaft (propeller shaft) of the present invention in a vehicle. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the power transmission shaft (propeller shaft) of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following embodiments, a case where the power transmission shaft (propeller shaft) is applied to a propeller shaft for an automobile as in the related art is exemplified and described.

[0026] Figure 1 This is a layout diagram showing the arrangement of the power transmission shaft (propeller shaft) of the present invention in a vehicle.

[0027] like Figure 1 As shown, the vehicle V is a so-called FR (front engine / rear drive) vehicle, and an engine EG and a transmission TM as a first power transmission device (speed change device) for transmitting the driving force of the engine EG are arranged on the front wheel axle FD connecting the front wheels FT. On the other hand, a differential DF as a second power transmission device (differential device) for transmitting power to the rear wheel axle RD is arranged at the center of the rear wheel axle RD connecting the rear wheels RT. And the transmission TM and the differential DF are connected via a propeller shaft PS as a power transmission shaft in a manner capable of transmitting power.

[0028] [First embodiment]

[0029] Figure 2 to Figure 8 FIG. 1 shows a first embodiment of the power transmission shaft of the present invention. It should be noted that, in the description of this embodiment, for convenience, Figure 2 The left side of is set as "front" and the right side is set as "back" for explanation. Figure 2 The description will be made by setting the direction along the rotation axis Z as an “axial direction”, the direction orthogonal to the rotation axis Z as a “radial direction”, and the direction around the rotation axis Z as a “circumferential direction”.

[0030] (Structure of the transmission shaft)

[0031] Figure 2 The entire state of the transmission shaft PS1 according to the first embodiment of the present invention is shown, and a half cross-sectional view of the transmission shaft PS1 cut along the direction of the rotation axis Z is shown.

[0032] like Figure 2As shown, the propeller shaft PS1 is disposed between the first power transmission device P1 disposed in front of the vehicle and the second power transmission device P2 disposed in rear of the vehicle. It should be noted that in this embodiment, the first power transmission device P1 corresponds to the transmission TM as a speed change device, and the second power transmission device P2 corresponds to the differential DF as a differential device.

[0033] That is, the transmission shaft PS1 of the present embodiment is a so-called one-piece transmission shaft, the front end side of which is connected to the first power transmission device P1 via the first joint component J1, and the rear end side is connected to the second power transmission device P2 via the second joint component J2. That is, the transmission shaft PS1 includes: a tube 1 formed in a substantially cylindrical shape; a first joint component J1, which is inserted into a first end 11 as a front end of the tube 1 for connection with the first power transmission device P1; and a second joint component J2, which is inserted into a second end 12 as a rear end of the tube 1 for connection with the second power transmission device P2.

[0034] The tube 1 is formed into a cylindrical shape having a certain inner diameter R1 in the axial direction by a carbon fiber reinforced resin material (so-called CFRP) formed by fixing carbon fibers with resin. In addition, the wall thicknesses T1 and T2 of the first end 11 and the second end 12 of the tube 1 are respectively formed to be thicker than the wall thickness T3 of the general part (axial middle part). Specifically, the tube 1 is formed integrally by stacking the above-mentioned carbon fiber reinforced resin material (CFRP) in the radial direction, and is formed to have at least two inner and outer layers including an inner peripheral layer 13 and an outer peripheral layer 14.

[0035] It should be noted that, in the present embodiment, the tube 1 is exemplified as a tube formed of a carbon fiber reinforced resin (CFRP), but the tube 1 may be formed of, for example, a metal material other than a fiber reinforced resin formed by fixing fibers with resin. In addition, when the tube 1 is formed of a fiber reinforced resin, in addition to the carbon fiber reinforced resin (CFRP) of the present embodiment, it may be formed of, for example, a glass fiber reinforced resin (FRP) formed by fixing glass fibers with resin.

[0036] The first joint member J1 includes a first shaft portion 2 inserted into the inner circumference 111 of the first end portion 11 of the tube 1 and a first joint portion 4 connecting the first shaft portion 2 and the first power transmission device P1. The first shaft portion 2 and the first joint portion 4 are fixed so as to be rotatable as a whole and are integrally formed as the first joint member J1.

[0037] The second joint member J2 includes a second shaft portion 3 inserted into the inner circumference 121 of the second end portion 12 of the tube 1 and a second joint portion 5 connecting the second shaft portion 3 and the second power transmission device P2. The second shaft portion 3 and the second joint portion 5 are fixed so as to be rotatable as a whole and are integrally formed as the second joint member J2.

[0038] The first shaft portion 2 includes: a first connection base portion 21, which is exposed from the first end portion 11 of the tube 1 and connected to the first joint portion 4; and a first insertion portion 22, which extends axially from the rear end portion of the first connection base portion 21 and is inserted into the inner circumference 111 of the first end portion 11 of the tube 1. The first connection base portion 21 and the first insertion portion 22 are integrally formed of a metal material.

[0039] The first connection base 21 includes: a first base 23; a first insertion side connection part 24, which is stepped from the rear end of the first base 23 and connected to the first insertion part 22; and a first joint side connection part 25, which is stepped from the front end of the first base 23 and connected to the first joint part 4. It should be noted that the first connection base 21 and the first joint part 4 constitute the first main body of the present invention.

[0040] The first insertion portion 22 is inserted into the inner circumference 111 of the first end portion 11 of the pipe 1 via a predetermined meshing mechanism (serrations in this embodiment) and is fixed so as to be rotatable together with the pipe 1. Specifically, the first insertion portion 22 has a first serration portion 26 formed on the outer circumference thereof over substantially the entire area in the axial direction, which can be serrated with the pipe 1.

[0041] The first serration 26 is formed as a groove 261 that is recessed radially inward and extends in a direction parallel to the rotation axis Z, and the outer diameter D1 of the tooth top 262 is set to be slightly larger than the inner diameter R1 of the tube 1. That is, for the first serration 26, the first insertion portion 22 is pressed into the inside of the first end portion 11 of the tube 1, and the tooth top 262 is engaged with the inner circumferential surface of the tube 1, so that the first insertion portion 22 and the tube 1 can be rotatably engaged as a whole. As a result, the first insertion portion 22 is supported in a fixed state at the inner circumferential portion 111 of the first end portion 11 of the tube 1 via the first serration 26.

[0042] In addition, a first collision load F1 as a holding load is set between the first serration 26 and the pipe 1, and the first collision load F1 releases the fixed state with the pipe 1 and causes the first insertion portion 22 to move from the first end portion 11 to the second end portion 12 side in the inner circumference of the pipe 1. It should be noted that the first collision load F1 can be set based on arbitrary meshing factors such as the meshing length L1 and the meshing amount X1 of the first serration 26 meshing with the inner circumference 111 of the first end portion 11 of the pipe 1.

[0043] The first joint portion 4 is composed of a free joint (for example, a constant velocity joint in the present embodiment), and is arranged on the opposite side of the axial direction of the tube 1 relative to the first shaft portion 2. That is, the first joint portion 4 has: a substantially cylindrical inner ring member 41, which is fixed to the outer peripheral surface of the first joint side connecting portion 25 of the first shaft portion 2; a substantially cylindrical outer ring member 42, which is arranged opposite to the outer peripheral side of the inner ring member 41; and a plurality of balls 43, which are rolling bodies arranged between the outer ring member 42 and the inner ring member 41 in a rollable manner.

[0044] In addition, the outer diameter D3 of the outer ring member 42 of the first joint portion 4 is set to be larger than the outer diameter D1 of the first insertion portion 22. Specifically, the structure is such that when the first shaft portion 2 enters the interior of the pipe 1 during a collision on the front side of the vehicle, the head 60 of the bolt 6 screwed into the first joint portion 4 from the pipe 1 side and fastened to the first power transmission device P1 abuts against the end surface (first end surface 112) on the side of the first end portion 11 of the pipe 1.

[0045] Here, in the present embodiment, the first crush length S1 that penetrates into the inner circumference 111 of the first end portion 11 of the tube 1 when the crush described later occurs is set according to the interval between the first end face 112 of the tube 1 and the head 60 of the bolt 6. The first crush length L1 is set to be longer than the second crush length S2 described later. Specifically, the first crush length S1 is set to be approximately twice the second crush length S2 described later. It should be noted that the first crush length S1 can be adjusted by the axial dimension of the first connection base 21, and can also be adjusted by the axial dimension of the head 60 of the bolt 6.

[0046] On the inner peripheral side of the inner ring component 41, there is a substantially circular shaft through hole 411 axially extending through the first joint side connection portion 25. That is, the first joint side connection portion 25 is pressed into the first joint side connection portion 25 over substantially the entire axial area of ​​the shaft through hole 411, and the first joint side connection portion 25 and the inner ring component 41 are fixed in a manner that allows them to rotate as a whole.

[0047] In addition, an inner ring side axial groove 412 in which the ball 43 can roll is formed along the axial direction on the outer peripheral side of the inner ring component 41. That is, the inner ring component 41 and the outer ring component 42 are allowed to move relative to each other in the axial direction by the rolling of the ball 43 between the inner ring side axial groove 412 and the outer ring side axial groove 421 described later, and the circumferential relative movement of the inner ring component 41 and the outer ring component 42 is restricted by the engagement of the ball 43 with the inner ring side axial groove 412 and the outer ring side axial groove 421.

[0048] The outer ring member 42 is fixed to the first power transmission device P1 in a manner that allows it to rotate integrally via a plurality of bolts 6 that penetrate the outer ring member 42 in the axial direction. In addition, an outer ring side axial groove 421 in which the ball 43 can roll is formed in the axial direction on the inner circumference of the outer ring member 42. That is, the outer ring member 42 and the inner ring member 41 are allowed to move relative to each other in the axial direction by the ball 43 rolling between the outer ring side axial groove 421 and the inner ring side axial groove 412, and the circumferential relative movement of the outer ring member 42 and the inner ring member 41 is restricted by the ball 43 engaging with the outer ring side axial groove 421 and the inner ring side axial groove 412.

[0049] According to this structure, the first power transmission device P1 rotates integrally with the outer ring member 42, whereby the rotational torque output from the first power transmission device P1 is transmitted from the outer ring member 42 to the inner ring member 41 via the balls 43. Based on the transmitted rotational torque, the inner ring member 41 rotates integrally with the first shaft portion 2 (first connection base 21).

[0050] The second shaft portion 3 includes: a second connection base portion 31, which is exposed from the second end portion 12 of the tube 1 and connected to the second joint portion 5; and a second insertion portion 32, which extends axially from the front end portion of the second connection base portion 31 and is inserted into the inner peripheral portion 121 of the second end portion 12 of the tube 1. The second connection base portion 31 and the second insertion portion 32 are integrally formed of a metal material.

[0051] The second connection base 31 includes: a second base 33; a second insertion side connection part 34, which is stepped from the front end of the second base 33 and connected to the second insertion part 32; and a second joint side connection part 35, which is stepped from the rear end of the second base 33 and connected to the second joint part 5. It should be noted that the second connection base 31 and the second joint part 5 constitute the second main body of the present invention.

[0052] The second insertion portion 32 is inserted into the inner circumference 121 of the second end portion 12 of the tube 1 via a predetermined meshing mechanism (serrations in this embodiment) and fixed to the tube 1 in a manner that allows for integral rotation. Specifically, the second insertion portion 32 has a second serration portion 36 formed on the outer circumference thereof over substantially the entire axial area that can be serrated with the tube 1.

[0053] It should be noted that, in the present embodiment, the axial dimension of the second serration 36 is set to be substantially the same as the axial dimension of the first serration 26. In other words, the second engagement length L2 set by the axial dimension of the second serration 36 is set to be substantially the same as the first engagement length L1 set by the axial dimension of the first serration 26.

[0054] The second serration 36 is formed as a groove 361 that is recessed radially inward and extends in a direction parallel to the rotation axis Z, and the outer diameter D2 of the tooth top 362 is set to be slightly larger than the inner diameter R1 of the tube 1. That is, the second insertion portion 32 of the second serration 36 is pressed into the interior of the second end portion 12 of the tube 1, and the tooth top 362 is engaged with the inner circumferential surface of the tube 1, so that the second insertion portion 32 and the tube 1 can be rotatably engaged as a whole. As a result, the second insertion portion 32 is supported in a fixed state at the inner circumferential portion 121 of the second end portion 12 of the tube 1 via the second serration 36.

[0055] It should be noted that, in the present embodiment, the outer diameter D2 of the tooth top 362 of the second sawtooth portion 36 is set to be substantially the same as the outer diameter D1 of the tooth top 262 of the first sawtooth portion 26. In other words, in the present embodiment, the second engagement amount X2 of the second sawtooth portion 36 is set to be substantially the same as the first engagement amount X1 of the first sawtooth portion 26.

[0056] In addition, a second collision load F2 is set between the second serration portion 36 and the pipe 1, and the second collision load F2 releases the fixed state with the pipe 1 and causes the second insertion portion 32 to move from the second end portion 12 to the first end portion 11 side in the inner circumference of the pipe 1. It should be noted that the second collision load F2 can also be set based on arbitrary meshing factors such as the meshing length L2 and the meshing amount X2 of the second serration portion 36 meshing with the inner circumference 121 of the second end portion 12 of the pipe 1, similarly to the first collision load F1.

[0057] In the present embodiment, the second engagement length L2 and the second engagement amount X2 of the second serration 36 are set to be the same as the first engagement length L1 and the first engagement amount X1 of the first serration 26 , whereby the second collision load F2 is set to be substantially the same as the first collision load F1 .

[0058] The second joint portion 5 is composed of a so-called rubber coupling, and is provided at a position on the opposite side of the axial direction of the tube 1 relative to the second shaft portion 3. That is, the second joint portion 5 is substantially annular, arranged at equal intervals in the circumferential direction, and has three first bolt through holes 51 for connection with the second joint side connection portion 35 of the second shaft portion 3 and three second bolt through holes 52 arranged at equal intervals in the circumferential direction between the first bolt through holes 51 and for connection with the second power transmission device P2.

[0059] That is, the second joint side connection portion 35 formed in a trident shape is fastened to the second joint portion 5 so as to be fixed so as to be rotatable as a whole via the first bolt 61 penetrating the first bolt through hole 51. On the other hand, the second power transmission device P2 formed in a trident shape is fastened to the second joint portion 5 so as to be fixed so as to be rotatable as a whole via the second bolt (not shown) penetrating the second bolt through hole 52.

[0060] It should be noted that, in the present embodiment, as described above, the second joint portion 5 is composed of a rubber coupling. Therefore, the second joint portion 5 is more difficult to bend than the first joint portion 4 composed of the above-mentioned constant velocity joint. That is, for the second joint portion 5, the load required when the second joint portion 5 is bent relative to the rotation axis Z, i.e., the second bending load B2, is greater than the load required when the first joint portion 4 is bent relative to the rotation axis Z, i.e., the first bending load B1. In other words, the transmission shaft PS1 is constructed so that the first joint portion 4 is bent at a relatively large first bending angle θ1 relative to the rotation axis Z, and the second joint portion 5 is bent at a relatively small second bending angle θ2 relative to the rotation axis Z (refer to Figure 3 (a) Figure 4 (a) Figure 5 (a)).

[0061] In addition, the second joint part 5 is set so that the outer diameter D4 of the second joint part 5 is larger than the outer diameter D2 of the second insertion part 32. Specifically, it is configured so that when the second shaft part 3 enters the interior of the tube 1 at the time of a collision on the rear side of the vehicle, the inner end face 351 of the second joint side connection part 35 can abut against the end face (second end face 122) on the side of the second end part 12 of the tube 1. It should be noted that in the present embodiment, a second crushing length S2 is set, and the second crushing length S2 passes through the interval between the second end face 122 of the tube 1 and the inner end face 351 of the second joint side connection part 35, and enters the inner circumference 121 of the second end part 12 of the tube 1 when the crush described later occurs.

[0062] (Crushed structure of the transmission shaft)

[0063] The following is based on Figure 3 to Figure 5 The crushing structure of the transmission shaft PS1 of the present embodiment is described. It should be noted that, hereinafter, "crushing" means that by inputting an axial load Fx to the transmission shaft PS1, the fixed state of the first insertion portion 22 and the second insertion portion 32 relative to the tube 1 is released (destroyed), and the first shaft portion 2 (first connection base 21) and the second shaft portion 3 (second connection base 31) are inserted into the interior of the tube 1.

[0064] In this way, the axial load Fx is buffered and the collision energy of the vehicle is absorbed by causing the first end 11 side and the second end 12 side of the pipe 1 to collapse. In other words, the axial load Fx is normally buffered by the first connection base 21 and the second connection base 31 being normally inserted into the inside of the pipe 1, thereby suppressing the inconvenience of the transmission shaft PS1 bending toward the vehicle body side.

[0065] Figure 3 It means from the front Figure 2The semi-longitudinal cross-sectional view of the power transmission shaft in the state of inputting collision load, (a) shows the state without crushing, (b) shows the state of crushing on the first end 11 side of the tube, and (c) shows the state of crushing on the second end 12 side of the tube.

[0066] like Figure 3 As shown in FIG. 1 , when an axial load Fx in the compression direction greater than the first collision load F1 acts on the front end side of the propeller shaft PS1 due to a front collision of the vehicle, the axial load Fx is transmitted from the first power transmission device P1 to the first shaft portion 2 via the first joint portion 4. Figure 3 In the normal state shown in (a), initially, the first end portion 11 of the tube 1 is crushed.

[0067] Specifically, between the first shaft portion 2 and the pipe 1, to which the axial load Fx greater than the first collision load F1 is input, Figure 3 As shown in (b), the fixed state between the first end portion 11 of the tube 1 and the first insertion portion 22 is released (destroyed), and the first connection base 21 is inserted into the inner circumference 111 of the first end portion 11 of the tube 1. Specifically, at the inner circumference 111 of the first end portion 11 of the tube 1, the first insertion portion 22 moves from the first end portion 11 to the second end portion 12 until the head 60 of the bolt 6 of the first joint portion 4 abuts against the first end surface 112 of the tube 1.

[0068] Next, the axial load Fx is transmitted from the first shaft portion 2 to the second shaft portion 3 via the tube 1, and the second shaft portion 3 sandwiched between the tube 1 and the second power transmission device P2 is subjected to the axial load Fx by reaction from the second power transmission device P2. As a result, a crush occurs on the second end portion 12 of the tube 1 later than the crush on the first end portion 11.

[0069] That is, between the second shaft portion 3 and the pipe 1, to which the axial load Fx greater than the second collision load F2 is input, Figure 3 As shown in (c), the fixed state between the second end 12 of the tube 1 and the second insertion portion 32 is released (destroyed), and the second connection base 31 is inserted into the second end 12 of the tube 1. Specifically, at the second end 12 of the tube 1, the second insertion portion 32 moves from the second end 12 to the first end 11 side until the inner end surface 351 of the second joint side connection portion 35 abuts against the second end surface 122 of the tube 1.

[0070] Figure 4 It means from the rear Figure 2 The semi-longitudinal cross-sectional view of the power transmission shaft shown in the state where the collision load is input, (a) shows a state where no crushing occurs, (b) shows a state where crushing occurs on the second end 12 side of the tube, and (c) shows a state where crushing occurs on the first end 11 side of the tube.

[0071] like Figure 4 As shown in FIG. 1 , when an axial load Fx in the compression direction greater than the second collision load F2 acts on the rear end side of the propeller shaft PS1 due to a vehicle collision from behind, the axial load Fx is transmitted from the second power transmission device P2 to the second shaft portion 3 via the second joint portion 5. Figure 4 In the normal state shown in (a), initially, the second end portion 12 of the tube 1 is crushed.

[0072] Specifically, between the second shaft portion 3 and the pipe 1, to which the axial load Fx greater than the second collision load F2 is input, Figure 4 As shown in (b), the fixed state between the second end portion 12 of the tube 1 and the second insertion portion 32 is released (destroyed), and the second connection base 31 is inserted into the inner circumference 121 of the second end portion 12 of the tube 1. Specifically, at the inner circumference 121 of the second end portion 12 of the tube 1, the first insertion portion 22 moves from the first end portion 11 to the second end portion 12 side until the inner end surface 351 of the second joint side connection portion 35 abuts against the second end surface 122 of the tube 1.

[0073] Next, the axial load Fx is transmitted from the second shaft portion 3 to the first shaft portion 2 via the tube 1, and the first shaft portion 2 sandwiched between the tube 1 and the first power transmission device P1 is subjected to the axial load Fx by reaction from the first power transmission device P1. As a result, a crush occurs on the first end portion 11 side of the tube 1 later than the crush on the second end portion 12 side.

[0074] That is, between the first shaft portion 2 and the pipe 1, to which the axial load Fx greater than the first collision load F1 is input, Figure 4 As shown in (c), the fixed state between the first end portion 11 of the tube 1 and the first insertion portion 22 is released (destroyed), and the first connection base 21 is inserted into the first end portion 11 of the tube 1. Specifically, at the inner circumference 111 of the first end portion 11 of the tube 1, the first insertion portion 22 moves from the first end portion 11 to the second end portion 12 until the head 60 of the bolt 6 of the first joint portion 4 abuts against the first end surface 112 of the tube 1.

[0075] Figure 5 It means from the front to the back Figure 2 The semi-longitudinal cross-sectional view of the power transmission shaft in a state where a collision load is inputted shows that (a) shows a state where no crushing occurs, and (b) shows a state where crushing occurs on both the first end 11 side and the second end 12 side of the pipe.

[0076] like Figure 5As shown, when an axial load Fx in the compression direction greater than the first collision load F1 and the second collision load F2 acts on the front and rear ends of the transmission shaft PS1 due to a collision in the front and rear directions of the vehicle, the axial load Fx is transmitted from the first power transmission device P1 and the second power transmission device P2 to the first shaft portion 2 and the second shaft portion 3 via the first joint portion 4 and the second joint portion 5. Figure 5 In the normal state shown in (a), the first end portion 11 and the second end portion 12 of the tube 1 are simultaneously crushed.

[0077] Specifically, between the first shaft portion 2 and the pipe 1, to which the axial load Fx greater than the first collision load F1 is input, Figure 4 As shown in (b), the fixed state between the first end portion 11 of the tube 1 and the first insertion portion 22 is released (destroyed), and the first connection base 21 penetrates into the inner peripheral portion 111 of the first end portion 11 of the tube 1. In addition, at the same time, between the second shaft portion 3 and the tube 1, which is input with an axial load Fx greater than the second collision load F2, as shown in FIG. Figure 4 As shown in (b) , the fixed state between the second end portion 12 of the tube 1 and the second insertion portion 32 is released (broken), and the second connection base 31 penetrates into the inner peripheral portion 121 of the second end portion 12 of the tube 1 .

[0078] Specifically, at the inner circumference 111 of the first end 11 of the tube 1, the first insertion portion 22 moves from the first end 11 to the second end 12 until the head 60 of the bolt 6 of the first joint portion 4 abuts against the first end face 112 of the tube 1. At the same time, at the inner circumference 121 of the second end 12 of the tube 1, the second insertion portion 32 moves from the second end 12 to the first end 11 until the inner end face 351 of the second joint-side connecting portion 35 abuts against the second end face 122 of the tube 1.

[0079] (Effects of this embodiment)

[0080] Figure 6 The diagrams are schematic diagrams for explaining the effects of the present invention when a crush occurs from the first end side. (a) is a diagram showing the crushed state of the power transmission shaft of the present invention, and (b) is a diagram showing the crushed state of a conventional power transmission shaft. Figure 7 The diagrams are schematic diagrams for explaining the effects of the present invention when crushing occurs from the second end side. (a) is a diagram showing the crushed state of the power transmission shaft of the present invention, and (b) is a diagram showing the crushed state of a conventional power transmission shaft. Figure 8 It is a schematic diagram for explaining the effect of the present invention when crushing occurs from both sides of the first end and the second end. (a) is a diagram showing the crushed state of the power transmission shaft of the present invention, and (b) shows the crushed state of the conventional power transmission shaft.

[0081] In the conventional transmission shaft PS0, the length of the first crush length S1, which is the length of the first shaft portion 2 connected to the first joint portion 4 composed of a constant velocity joint that is relatively easy to bend, and the second crush length S2, which is the length of the second shaft portion 3 connected to the second joint portion 5 composed of a rubber coupling that is relatively difficult to bend, are not considered at all. Therefore, in the transmission shaft PS0 in which the second crush length S2 is longer than the first crush length S1, there is room for improvement in that the collision performance of the transmission shaft PS0 becomes unstable.

[0082] Specifically, if Figure 6 As shown in (b), when the axial load Fx is input from the front (first end 11 side), the first end 11 side is first crushed. As a result, the first insertion portion 22 of the first joint component J1, which has a relatively small first buckling load B1 and is relatively easy to buckle, moves from the first end 11 side to the second end 12 side, and the first connection base 21 enters the inside of the tube 1, and the first joint portion 4 abuts against the first end surface 112 of the tube 1. Here, when the first joint portion 4 abuts against the tube 1 at an angle θ, the first joint portion 4 is acted in the following manner to make the first joint portion 4 coincide with the first end surface 112 of the tube 1, that is, the first moment M1 is generated in the first joint portion 4, and the second moment M2 is generated in the tube 1, and the second end 12 side of the tube 1 is lifted. As a result, the transmission shaft PS0, whose second crush length S2 is longer than the first crush length S1, forms an angle θ between the second shaft portion 3 and the tube 1. As a result, the second shaft portion 3 is stuck in the inner circumference 121 of the second end 12 of the tube 1, and it is difficult for the second shaft portion 3 to enter the inside of the tube 1. As a result, the collision performance of the propeller shaft PS0 may deteriorate.

[0083] On the one hand, if Figure 7 As shown in (b), when the axial load Fx is input from the rear (the second end 12 side), crushing occurs first on the second end 12 side. In this case, in the transmission shaft PS0 in which the second crushing length S2 is longer than the first crushing length S1, the relatively long second shaft portion 3 first enters the interior of the tube 1. Therefore, the first shaft portion 2 can enter the interior of the tube 1 relatively smoothly, and the collision performance of the transmission shaft PS0 will not be deteriorated.

[0084] On the other hand, Figure 8As shown in (b), when an axial load Fx is input from the front-to-back direction (the first end 11 side and the second end 12 side), crushing occurs simultaneously on the first end 11 side and the second end 12 side. As a result, while the first insertion portion 22 moves from the first end 11 side to the second end 12 side and the first connection base 21 enters the interior of the tube 1, the second insertion portion 32 moves from the second end 12 side to the first end 11 side and the second connection base 31 enters the interior of the tube 1. Here, in the transmission shaft PS0 in which the second crushing length S2 is longer than the first crushing length S1, the first joint portion 4 contacts the first end surface 112 before the second joint portion 5 contacts the second end surface 122. Then, since the first joint portion 4 having a relatively small first buckling load B1 abuts against the pipe 1 at a relatively large angle θ, the first joint portion 4 and the first end surface 112 of the pipe 1 are acted in such a manner that the first joint portion 4 is aligned with each other, that is, a first moment M1 is generated in the first joint portion 4, and a second moment M2 is generated in the pipe 1, thereby lifting the second end portion 12 side of the pipe 1. Thus, since the angle θ is formed between the second shaft portion 3 and the pipe 1, the second shaft portion 3 is caught in the inner circumference 121 of the second end portion 12 of the pipe 1, and it is difficult for the second shaft portion 3 to enter the interior of the pipe 1. As a result, the collision performance of the transmission shaft PS0 may be deteriorated.

[0085] On the other hand, in the propeller shaft PS1 of the present embodiment, the following effects are achieved, thereby being able to solve the technical problems of the above-mentioned conventional propeller shafts.

[0086] The transmission shaft PS1 is a power transmission shaft (transmission shaft) for transmitting power between the first power transmission device P1 and the second power transmission device P2 of the vehicle, and comprises: a tube 1 formed in a cylindrical shape; a first joint component, which is a first joint component J1, having a first main body portion (a first connection base portion 21 and a first joint portion 4) and a first insertion portion 22, wherein the outer periphery of the first insertion portion 22 is supported in a fixed state on the inner periphery 1 of the first end portion 11 and the second end portion 12, which are a pair of end portions in the direction of the rotation axis Z of the tube 1. 11, and is configured so that when an input load greater than a first collision load F1 is applied, the fixed state with the pipe 1 is released, so that the first insertion portion 22 can move from the first end portion 11 of the pipe 1 toward the second end portion 12, and the first main body portion (the first connection base 21 and the first joint portion 4) is arranged at a position on the opposite side of the first insertion portion 22 than the first end portion 11 in the direction of the above-mentioned rotation axis Z, and is connected to the first power transmission device P1 via the first joint portion 4 that can bend relative to the direction of the above-mentioned rotation axis Z by the action of the first buckling load B1; the second joint portion The second joint component J2 has a second main body (a second connection base 31 and a second joint part 5) and a second insertion part 32. For the second insertion part 32, the outer periphery of the second insertion part 32 is supported on the inner periphery 121 of the second end part 12 of the pipe 1 in a fixed state, and is configured so that when an input load greater than the second collision load F2 is applied, the fixed state with the pipe 1 is released, so that the second insertion part 32 can move from the second end part 12 of the pipe 1 toward the first end part 11, and the second main body (the second connection base 31 and the second joint part 5) is fixed on the above-mentioned rotation axis. The second joint portion 5 is arranged at a position on the opposite side of the second insertion portion 32 than the second end portion 12 in the direction of the line Z, and is connected to the second power transmission device P2 via the second joint portion 5. The second joint portion 5 is set so that the second bending load B2 required when bending relative to the direction of the above-mentioned rotation axis Z is greater than the first bending load B1. When the input load acts on the first joint component J1 and the second joint component J2, the first crushing length S1 of the first joint component J1 entering the inner peripheral portion 111 of the tube 1 is formed to be longer than the second crushing length S2 of the second joint component J2 entering the inner peripheral portion 121 of the tube 1.

[0087] Thus, in the propeller shaft PS1 of the present embodiment, the first crush length S1 of the first joint member J1 that buckles due to the first buckling load B1 is set to be longer than the second crush length S2 of the second joint member J2 that buckles due to the second buckling load B2 that is larger than the first buckling load B1.

[0088] Therefore, when the front (first end 11) side is crushed first, Figure 6As shown in (a), when the first shaft portion 2 of the first joint member J1 which is relatively easy to bend and has a relatively small first buckling load B1 enters the interior of the tube 1, when the first joint portion 4 abuts the first end portion 11 of the tube 1 at an angle θ, the first joint portion 4 acts in the following manner to make the first joint portion 4 coincide with the first end surface 112 of the tube 1, that is, a first moment M1 is generated in the first joint portion 4, and a second moment M2 is generated in the tube 1, thereby lifting the second end portion 12 side of the tube 1. As a result, the second shaft portion 3 forms an angle θ with respect to the tube 1, but the second crush length S2 is relatively shorter than the first crush length S1, so that the second shaft portion 3 easily enters the interior of the tube 1. As a result, the stability of the collision performance of the transmission shaft PS1 can be improved.

[0089] On the one hand, in the case where the rear side (the second end 12 side) is crushed first, Figure 7 As shown in (a), the second buckling load B2 is greater than the first buckling load B1, and the second joint portion 5 is relatively difficult to buckle. Therefore, when the second shaft portion 3 enters the interior of the tube 1, the second shaft portion 3 and the tube 1 are unlikely to form an angle, and even if the second joint portion 5 is in contact with the second end surface 122 of the tube 1 in a manner that is consistent, large moments (first and second moments M1, M2) will not act on the tube 1. As a result, an angle is unlikely to be formed between the first shaft portion 2 of the first joint component J1 and the tube 1, and the first shaft portion 2 easily enters the interior of the tube 1, which can improve the stability of the collision performance of the transmission shaft PS1.

[0090] On the other hand, when the first end portion 11 and the second end portion 12 are crushed at approximately the same time, as shown in FIG. Figure 8 As shown in (a), the second crush length S2 is set relatively short relative to the first crush length S1, so that the second joint part 5 abuts against the second end face 122 of the tube 1 before the first joint part 4 abuts against the first end face 112 of the tube 1. In addition, at this time, the second buckling load B2 is greater than the first buckling load B1, and the second joint part 5 is a relatively difficult structure to buckle. Therefore, even if the second joint part 5 abuts against the second end face 122 of the tube 1 in a manner that is consistent, large moments (first and second moments M1, M2) will not act on the tube 1. As a result, it is difficult to generate an angle between the first shaft part 2 of the first joint component J1 and the tube 1, and the first shaft part 2 easily enters the interior of the tube 1, which can improve the stability of the collision performance of the transmission shaft PS1.

[0091] Furthermore, in the present embodiment, when an input load acts on the first joint member J1 and the second joint member J2 , a first time during which the first joint portion 4 abuts the first end portion 11 of the pipe 1 is longer than a second time during which the second joint portion 5 abuts the second end portion 12 of the pipe 1 .

[0092] Thus, in this embodiment, the first time that the first joint part 4 abuts against the first end 11 of the tube 1 is longer than the second time that the second joint part 5 abuts against the second end 12 of the tube 1. Therefore, when the second end 12 side is first crushed, or when the first end 11 side and the second end 12 side are crushed at the same time, the second joint part 5 abuts against the second end 12 of the tube 1 before the first joint part 4 abuts against the first end 11 of the tube 1. In this case, even if the second joint part 5 abuts against the second end face 122 of the tube 1 in a manner consistent with each other, large moments (first and second moments M1, M2) will not act on the tube 1. As a result, it is difficult to generate an angle between the first shaft part 2 of the first joint component J1 and the tube 1, and the first shaft part 2 easily enters the interior of the tube 1, which can improve the stability of the collision performance of the transmission shaft PS1.

[0093] Furthermore, in the present embodiment, the first joint member J1 is connected to the first power transmission device P1 via a constant velocity joint.

[0094] Thus, in this embodiment, the first joint member J1 is connected to the first power transmission device P1 via the first joint portion 4 formed of a constant velocity joint. Compared with the case where the first joint portion 4 is formed of a universal joint, the deviation of the buckling load is small, so there is an advantage that the collision performance of the propeller shaft PS1 is easily stabilized.

[0095] In addition, in this embodiment, the above-mentioned constant velocity joint (joint portion 4) is fastened to the first power transmission device P1 via a bolt 6 screwed from the tube 1 side toward the first power transmission device P1 side, and the first crushing length S1 is the distance from the first end portion 11 of the tube 1 to the head 60 of the bolt 6.

[0096] Thus, in this embodiment, the first joint portion 4 formed of the constant velocity joint is fastened to the first power transmission device P1 via the bolts 6. This bolt fastening is a general-purpose coupling mechanism, which can reduce the manufacturing cost of the propeller shaft PS1 and improve the installation workability of the propeller shaft PS1 to the vehicle V.

[0097] The first crush length S1 is set according to the distance from the first end 11 of the tube 1 to the head 60 of the bolt 6. Therefore, there is an advantage that the first crush length S1 can be easily adjusted by adjusting the height of the head 60 of the bolt 6.

[0098] In this embodiment, the second joint member J2 is fastened to the second power transmission device P2 via a rubber coupling, and the second crush length S2 is the distance from the second end 12 of the tube 1 to the yoke (second joint side connection portion 35) connected to the rubber coupling.

[0099] Thus, in this embodiment, the second joint member J2 is connected to the second power transmission device P2 via the second joint portion 5 formed of the rubber coupling. Therefore, the vibration of the vehicle V can be absorbed by the rubber coupling, and the acoustic and vibration performance of the vehicle V can be improved.

[0100] In addition, the second crush length S2 is set by the distance from the second end 12 of the tube 1 to the second joint side connection part 35 as a fork connected to the rubber coupling. The rubber coupling (second joint part 5) forms a plane extending in a direction orthogonal to the direction of the rotation axis Z. Therefore, by making the plane of the rubber coupling (second joint part 5) abut against the second end face 122 of the tube 1, it helps to improve the stability of the collision performance of the transmission shaft PS1.

[0101] In addition, in the present embodiment, the rotation axis of the first main body portion (the first connecting base 21 and the first joint portion 4) is connected to the first power transmission device P1 at a first flexion angle θ1 relative to the rotation axis Z of the tube 1, and the rotation axis of the second main body portion (the second connecting base 31 and the second joint portion 5) is connected to the second power transmission device P2 at a second flexion angle θ2 relative to the rotation axis Z of the tube 1, and the first flexion angle θ1 is smaller than the second flexion angle θ2.

[0102] Thus, in the present embodiment, the first buckling angle θ1 of the first joint member J1 is set to be smaller than the second buckling angle θ2 of the second joint member J2. Generally, if a larger buckling angle is given to a member with a large buckling load, it may cause the generation of noise and vibration. Therefore, by increasing the first buckling angle θ1 of the first joint member J1 with a relatively large buckling load and reducing the second buckling angle θ2 of the second joint member J2 with a relatively small buckling load, the generation of the above-mentioned noise and vibration can be suppressed, thereby achieving an improvement in the noise and vibration performance of the transmission shaft PS1.

[0103] In addition, if a larger buckling angle is given to a member having a relatively large buckling load, a large amount of heat is generated due to the large buckling, and a part of the power energy is lost due to the generation of the heat, and the power transmission efficiency may be reduced. Therefore, by increasing the first buckling angle θ1 of the first joint member J1 having a large buckling load and decreasing the second buckling angle θ2 of the second joint member J2 having a small buckling load, the power energy lost due to the buckling of the second joint member J2 can be reduced, and the power transmission efficiency of the propeller shaft PS1 can be improved.

[0104] Furthermore, in the present embodiment, at least one of the first insertion portion 22 and the second insertion portion 32 is coupled to the inner peripheral portion of the tube 1 via serrations.

[0105] Thus, in the present embodiment, the first insertion portion 22 is coupled to the inner peripheral portion 111 of the first end portion 11 of the tube 1 via the first serration portion 26, and the second insertion portion 32 is coupled to the inner peripheral portion 121 of the second end portion 12 of the tube 1 via the second serration portion 36. Therefore, compared with the case where the first insertion portion 22 and the second insertion portion 32, whose outer peripheral surfaces are formed to be substantially flat, are coupled to the inner peripheral portion of the tube 1 by simple press-fitting or bonding, the first insertion portion 22 and the second insertion portion 32 can be more firmly fixed. Thus, a large torque resistance performance can be ensured in the rotation direction of the transmission shaft PS1, and a large holding load can be obtained in the axial direction of the transmission shaft PS1.

[0106] In the present embodiment, the first power transmission device P1 is a transmission TM of the vehicle V, the second power transmission device P2 is a differential DF of the vehicle V, and the second joint member J2 is composed of a rubber coupling.

[0107] Thus, in this embodiment, the second joint member J2 connecting the propeller shaft PS1 and the differential DF of the vehicle V is formed of a rubber coupling. Therefore, the vibration of the differential DF can be absorbed and cut off by the rubber coupling, and the noise and vibration performance of the propeller shaft PS1 can be improved.

[0108] In addition, in the present embodiment, the tube 1 is formed of a material in which fibers are fixed with resin.

[0109] Thus, in this embodiment, the tube 1 is formed of a fiber-reinforced resin material formed by fixing fibers with resin. Therefore, compared with the case where the tube 1 is formed of a metal material, the tube 1 can be made lighter, which contributes to improving the fuel efficiency of the automobile.

[0110] Furthermore, since the pipe 1 is formed of the fiber-reinforced resin material, the echo of sound in the pipe 1 can be reduced compared to the case where the pipe 1 is formed of a metal material, which can also contribute to improving the acoustic and vibration performance of the propeller shaft PS1.

[0111] In particular, in the present embodiment, the pipe 1 is formed of carbon fiber reinforced resin (CFRP).

[0112] As described above, in the present embodiment, the tube 1 is formed of carbon fiber reinforced resin (CFRP), so the tube 1 has higher strength than other fiber reinforced resins such as glass fiber reinforced resin (FRP), and can be further reduced in weight.

[0113] In addition, as another example of this embodiment, the tube 1 may be formed of glass fiber reinforced resin (FRP) as described above. In this case, the tube 1 can be formed more cheaply than when the tube 1 is formed of other fiber reinforced resins, such as carbon fiber reinforced resin (CFRP).

[0114] [Second embodiment]

[0115] Fig. 9 The second embodiment of the power transmission shaft (propeller shaft) of the present invention is shown in which the structure of the first joint component J1 of the propeller shaft PS1 of the first embodiment is changed. It should be noted that the basic structure other than the change is the same as that of the first embodiment, and therefore, the same reference numerals are given to the same structures as those of the first embodiment, and the description thereof is omitted. In addition, in the description of this embodiment, for convenience, Fig. 9 The left side is set to "front" and the right side is set to "back" for explanation, and the Fig. 9 The description will be given by setting the direction of the rotation axis Z as an “axial direction”, the direction orthogonal to the rotation axis Z as a “radial direction”, and the direction around the rotation axis Z as a “circumferential direction”.

[0116] (Structure of the transmission shaft)

[0117] Fig. 9 The entire state of the transmission shaft PS2 according to the second embodiment of the present invention is shown, and a half cross-sectional view of the transmission shaft PS2 cut along the direction of the rotation axis Z is shown.

[0118] like Fig. 9 As shown, the first joint portion 4 of the first joint member J1 of the transmission shaft PS2 of this embodiment is not composed of the constant velocity joint of the first embodiment, but is composed of a well-known universal joint. That is, the first joint member J1 has a transmission TM (see FIG. 1 ) corresponding to the first power transmission device P1. Figure 1 ) a first fork 71 connected to the tube 1 , a second fork 72 connected to the tube 1 , and a cross shaft 73 disposed between the first fork 71 and the second fork 72 .

[0119] The first shift fork 71 is in a double fork shape facing each other in the radial direction, and the first shaft insertion hole 710 for inserting the pair of first shaft portions 731 in the cross shaft 73 is formed in a through state in the radial direction. Figure 1 ) side is integrally formed with a connecting shaft portion 74 extending in the axial direction, and is connected to an output shaft (not shown) of the transmission TM via the connecting shaft portion 74.

[0120] The connecting shaft portion 74 includes a vehicle-side connecting portion 741 connected to the output shaft (not shown) of the transmission TM via a spline, and a fork-side connecting portion 742 provided in a stepped and expanded shape at the rear end side of the vehicle-side connecting portion 741 and connected to the first fork 71. The vehicle-side connecting portion 741 and the fork-side connecting portion 742 are formed integrally. The vehicle-side connecting portion 741 is formed in a substantially cylindrical shape and inserted into the transmission case (not shown) of the transmission TM. The internal spline portion 741a formed on the inner circumference is spline-coupled with the external spline portion provided on the outer circumference of the output shaft (not shown) of the transmission TM, thereby being connected in a manner that allows relative movement in the axial direction.

[0121] The second fork 72 is in a double fork shape opposed in the radial direction, and the second shaft insertion hole 720 for inserting the other pair of second shaft portions 732 in the cross shaft 73 is formed in a through state along the radial direction, and is arranged to be staggered relative to the first fork 71 in the circumferential direction. In addition, the second fork 72 is formed integrally with the first connection base 21 of the first shaft portion 2 to constitute the first joint side connection portion 25, and is connected to the pipe 1 via the first insertion portion 22.

[0122] (Effects of this embodiment)

[0123] As described above, in the propeller shaft PS2 of the present embodiment, the first joint member J1 is connected to the first power transmission device P1 (see Figure 1 )connect.

[0124] Thus, in the present embodiment, the first joint member J1 is connected to the first power transmission device P1 via the universal joint. This has the advantage that the manufacturing cost of the propeller shaft PS2 can be reduced compared to the case where the first joint member J1 is formed of a constant velocity joint.

[0125] [Third embodiment]

[0126] Fig.10 The third embodiment of the power transmission shaft (propeller shaft) of the present invention is shown in which the structures of the first insertion portion 22 and the second insertion portion 32 in the propeller shaft PS1 of the first embodiment are changed. It should be noted that the basic structure other than the change is the same as that of the first embodiment, and therefore, the same reference numerals are given to the same structures as those of the first embodiment, and the description thereof is omitted. In addition, in the description of this embodiment, for convenience, Fig.10 The left side is set to "front" and the right side is set to "back" for explanation, and the Fig.10 The description will be given by assuming that the direction of the rotation axis Z is an “axial direction”, the direction orthogonal to the rotation axis Z is a “radial direction”, and the direction around the rotation axis Z is a “circumferential direction”.

[0127] (Structure of the transmission shaft)

[0128] Fig.10 The entire configuration of a transmission shaft PS3 according to a third embodiment of the present invention is shown, and a half cross-sectional view of the transmission shaft PS3 cut along the direction of the rotation axis Z is shown.

[0129] like Fig.10 As shown, in the transmission shaft PS3 of this embodiment, the pipe 1 is formed of a metal material. Also, in the transmission shaft PS3, the first insertion portion 22 is spline-coupled to the first end portion 11 of the pipe 1, and the second insertion portion 32 is spline-coupled to the second end portion 12 of the pipe 1.

[0130] That is, a first internal spline portion 15 having a known spline extending in the axial direction is formed on the inner circumference 111 of the first end portion 11 of the pipe 1. On the other hand, a first external spline portion 27 having a known spline that meshes with the first internal spline portion 15 of the pipe 1 and can move in the axial direction along the first internal spline portion 15 is formed on the outer circumference of the first insertion portion 22. Furthermore, the first insertion portion 22 is pressed into the first internal spline portion 15 of the pipe 1 via the first external spline portion 27.

[0131] In addition, the second inner spline portion 16 having a known spline extending in the axial direction is formed on the inner circumference 121 of the second end portion 12 of the pipe 1, similarly to the first end portion 11. On the other hand, the second outer serration portion 37 having a known spline meshing with the second inner serration portion 16 of the pipe 1 and movable in the axial direction along the second inner serration portion 16 is formed on the outer circumference of the second insertion portion 32 of the pipe 1. The second outer serration portion 37 has a known spline that meshes with the second inner serration portion 16 of the pipe 1 and can move in the axial direction along the second inner serration portion 16. And the second insertion portion 32 is pressed into the second inner spline portion 16 of the pipe 1 via the second outer spline portion 37.

[0132] (Effects of this embodiment)

[0133] As described above, in the propeller shaft PS3 of the present embodiment, at least one of the first insertion portion 22 and the second insertion portion 32 is spline-coupled to the inner peripheral portion of the pipe 1 .

[0134] Thus, in the present embodiment, the first insertion portion 22 and the second insertion portion 32 are splined to the inner circumference of the tube 1. Therefore, compared with the case where the first insertion portion 22 and the second insertion portion 32 are serrated, crushing can be generated with a smaller collision load. Thus, the generation of crushing can be controlled, which contributes to the stabilization of the collision performance of the transmission shaft PS3.

[0135] In addition, in the present embodiment, the pipe 1 is formed of a metal material.

[0136] As described above, in the present embodiment, the pipe 1 is formed of a metal material. Therefore, the pipe 1 can be formed at a low cost, which can contribute to a reduction in the manufacturing cost of the propeller shaft PS3.

[0137] Furthermore, in the present embodiment, the first insertion portion 22 includes the first external spline portion 27 that meshes with the first internal spline portion 15 formed on the inner peripheral portion of the pipe 1 .

[0138] Thus, in the present embodiment, the first insertion portion 22 is spline-coupled to the pipe 1 via the first external spline portion 27 meshing with the first internal spline portion 15 of the pipe 1. Therefore, compared with the case where the pipe 1 is formed of a fiber-reinforced resin, the transmission shaft PS3 can be manufactured at a relatively low cost, and at the first end portion 11 of the pipe 1, the looseness between the first insertion portion 22 and the pipe 1 can be reduced, which has the advantage of good torque transmission from the first insertion portion 22 to the pipe 1.

[0139] Furthermore, in the present embodiment, the second insertion portion 32 includes the second external spline portion 37 that meshes with the second internal spline portion 16 formed on the inner peripheral portion of the pipe 1 .

[0140] Thus, in the present embodiment, the second insertion portion 32 is spline-coupled to the tube 1 via the second outer spline portion 37 meshing with the second inner spline portion 16 of the tube 1. Therefore, compared with the case where the tube 1 is formed of a fiber-reinforced resin, the transmission shaft PS3 can be manufactured at a relatively low cost, and at the second end portion 12 of the tube 1, the looseness between the second insertion portion 32 and the tube 1 can be reduced, which has the advantage of good torque transmission from the tube 1 to the second insertion portion 32.

[0141] The present invention is not limited to the configurations and forms illustrated in the above-mentioned embodiments, and can be freely changed according to the specifications, cost, etc. of the application object as long as the above-mentioned effects of the present invention can be exerted.

[0142] For example, in the above-mentioned embodiments, the first power transmission device P1 is provided as a transmission TM mounted on the vehicle, and the second power transmission device P2 is provided as a differential DF mounted on the vehicle. Fig.11 As shown, the structure may be the opposite. Specifically, for example, it can also be applied to a vehicle having the following drive mode: a vehicle having a rear engine / all-wheel drive drive mode, the engine EG and the transmission TM are mounted at the rear of the vehicle, and the driving force of the engine EG output from the transmission TM is transmitted to the differential DF mounted at the front of the vehicle through the transmission shaft PS. That is, the first power transmission device P1 may also be the differential DF of the vehicle V, and the second power transmission device P2 may also be the transmission TM of the vehicle V.

[0143] According to this modification, the first joint member J1 that is relatively easy to bend is connected to the differential DF that moves relatively greatly. Therefore, the first joint member J1 that is relatively easy to bend can absorb the movement of the differential DF, thereby improving the noise and vibration performance of the propeller shaft PS.

[0144] In the case of a vehicle in which the transmission TM is provided on the driving wheel (rear wheel) side, the first power transmission device P1 may be used as a driving source such as an engine, and the second power transmission device P2 may be used as the transmission TM, or vice versa.

[0145] Furthermore, the first power transmission device P1 can also be applied to a vehicle using an electric motor as a continuously variable transmission instead of the above-mentioned transmission TM.

[0146] In addition, in the above-mentioned embodiments, an example is given of a case where the first collision load F1 and the second collision load F2 are set to be the same, and the first collision load F1 and the second collision load F2 are formed by setting the first engagement length L1 and the second engagement length L2, and the first engagement amount X1 and the second engagement amount X2 to be approximately the same. However, in addition to the relative relationship between the above-mentioned first crushing length S1 and the second crushing length S2, the first collision load F1 and the second collision load F2 can be adjusted by setting a difference between the first engagement length L1 and the second engagement length L2, or the first engagement amount X1 and the second engagement amount X2, and the order of crushing of the first joint component J1 and the second joint component J2 can be controlled, thereby improving the stabilization of the collision performance of each drive shaft PS1, PS2, and PS3.

Claims

1. A power transmission shaft for transmitting power between a first power transmission device and a second power transmission device of a vehicle, characterized in that: have: A tube formed in the shape of a cylinder; and a first coupling member having a first main body and a first insertion portion, wherein the first insertion portion, of a pair of ends in the direction of the rotation axis of the tube, namely, a first end and a second end, an outer peripheral portion of the first insertion portion is supported in a fixed state on an inner peripheral portion of the first end, and is arranged so that when an input load greater than a first collision load is applied, the fixed state with the tube is released, so that the first insertion portion can move from the first end of the tube toward the second end, the first main body is arranged in the direction of the rotation axis at a position on the opposite side of the first insertion portion than the first end, and is connected to the first power transmission device via the first coupling member, and the first coupling member can bend relative to the direction of the rotation axis by applying a first bending load; and a second joint component having a second main body and a second insertion portion, wherein the outer periphery of the second insertion portion is supported in a fixed state on the inner periphery of the second end portion of the tube, and is configured so that when an input load greater than a second collision load acts, the fixed state with the tube is released, so that the second insertion portion can move from the second end portion of the tube toward the first end portion, the second main body portion is disposed at a position on the opposite side of the second insertion portion than the second end portion in the direction of the rotation axis, and is connected to the second power transmission device via the second joint portion, and the second joint portion is configured so that a second buckling load required when the second joint portion is buckled in the direction relative to the rotation axis is greater than the first buckling load; When an input load acts on the first joint member and the second joint member, a first crushing length of the first joint member entering the inner peripheral portion of the tube is formed to be longer than a second crushing length of the second joint member entering the inner peripheral portion of the tube.

2. The power transmission shaft according to claim 1, wherein: When an input load acts on the first joint member and the second joint member, a first time that the first joint portion abuts the first end of the pipe is longer than a second time that the second joint portion abuts the second end of the pipe.

3. The power transmission shaft according to claim 1, wherein: The first joint member is connected to the first power transmission device via a constant velocity joint.

4. The power transmission shaft according to claim 3, wherein: The constant velocity joint is fastened to the first power transmission device via a bolt screwed from the pipe side toward the first power transmission device side. The first crush length is a distance from the first end portion of the tube to the head portion of the bolt.

5. The power transmission shaft according to claim 3, wherein: The second joint member is fastened to the second power transmission device via a rubber coupling. The second crush length is a distance from the second end of the tube to a fork connected to the rubber coupling.

6. The power transmission shaft according to claim 1, wherein: The rotation axis of the first main body is connected to the first power transmission device at a first flexion angle relative to the rotation axis of the tube. The rotation axis of the second main body is connected to the second power transmission device at a second flexion angle relative to the rotation axis of the tube. The first flexion angle is smaller than the second flexion angle.

7. The power transmission shaft according to claim 1, wherein: The first joint member is connected to the first power transmission device via a universal joint.

8. The power transmission shaft according to claim 1, wherein: At least one of the first insertion portion and the second insertion portion is coupled to the inner peripheral portion of the tube via serrations.

9. The power transmission shaft according to claim 1, wherein: At least one of the first insertion portion and the second insertion portion is spline-connected to the inner peripheral portion of the tube.

10. The power transmission shaft according to claim 1, wherein: The first power transmission device is a transmission of a vehicle, The second power transmission device is a differential of the vehicle, The second joint component is composed of a rubber coupling.

11. The power transmission shaft according to claim 1, wherein: The first power transmission device is a differential of the vehicle, The second power transmission device is a transmission of a vehicle.

12. The power transmission shaft according to claim 1, wherein: The tube is formed of a material in which fibers are fixed with a resin.

13. The power transmission shaft according to claim 1, wherein: The tube is formed of a metallic material.

14. The power transmission shaft according to claim 13, wherein: The first insertion portion has a first external spline portion that meshes with a first internal spline portion formed on an inner peripheral portion of the pipe.

15. The power transmission shaft according to claim 13, wherein: The second insertion portion has a second external spline portion that meshes with a second internal spline portion formed on an inner peripheral portion of the pipe.

16. A transmission shaft for transmitting power between a first power transmission device and a second power transmission device of a vehicle, characterized in that: have: A tube formed in the shape of a cylinder; and a first coupling member having a first main body and a first insertion portion, wherein the first insertion portion, of a pair of ends in the direction of the rotation axis of the tube, namely, a first end and a second end, an outer peripheral portion of the first insertion portion is supported in a fixed state on an inner peripheral portion of the first end, and is arranged so that when an input load greater than a first collision load is applied, the fixed state with the tube is released, so that the first insertion portion can move from the first end of the tube toward the second end, the first main body is arranged in the direction of the rotation axis at a position on the opposite side of the first insertion portion than the first end, and is connected to the first power transmission device via the first coupling member, and the first coupling member can bend relative to the direction of the rotation axis by applying a first bending load; and a second joint component having a second main body and a second insertion portion, wherein the outer periphery of the second insertion portion is supported in a fixed state on the inner periphery of the second end portion of the tube, and is configured so that when an input load greater than a second collision load acts, the fixed state with the tube is released, so that the second insertion portion can move from the second end portion of the tube toward the first end portion, the second main body portion is disposed at a position on the opposite side of the second insertion portion than the second end portion in the direction of the rotation axis, and is connected to the second power transmission device via the second joint portion, and the second joint portion is configured so that a second buckling load required when the second joint portion is buckled in the direction relative to the rotation axis is greater than the first buckling load; When an input load acts on the first joint member and the second joint member, a first crushing length of the first joint member entering the inner peripheral portion of the tube is formed to be longer than a second crushing length of the second joint member entering the inner peripheral portion of the tube.

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