JP4200853B2 - Driving force transmission device and unbalance confirmation method thereof - Google Patents

Description

  The present invention is, for example, a start clutch that is interposed in a power transmission system of a vehicle, particularly a drive such as a coupling that is interposed between a front wheel side drive system and a rear wheel side drive system in a four-wheel drive vehicle. The present invention relates to a force transmission device and an unbalance confirmation method for the driving force transmission device.

Conventionally, the following driving force transmission device 1 shown in FIG.
When the electromagnet 27 is energized by the electromagnetic clutch mechanism 24, the armature 25 is attracted by the electromagnet 27 and the pilot friction clutch 26 comes into frictional contact. When relative rotation occurs between the outer case 14 and the inner case 17, for example, torque T in the direction shown in FIG. 15B is generated in the pilot cam body 32 during forward drive, and during reverse drive or engine braking. Sometimes torque T in the direction shown in FIG. 15C is generated in the pilot cam body 32. In any driving state, the torque T amplified by the cam mechanism 23 (the main cam body 31, the spherical cam body 38, and the pilot cam body 32) is converted into the thrust S in the directions of the rotation center lines 14a and 17a. The main friction clutch 22 is connected according to the thrust S, and the driving force is transmitted between the outer case 14 and the inner case 17.

On the other hand, when the attraction of the electromagnet 27 with respect to the armature 25 is released in a non-driven state where the electromagnet 27 of the electromagnetic clutch mechanism 24 is not energized, the pilot cam body 32 in the cam mechanism 23 as shown in FIG. And the main cam body 31 rotate together via the spherical cam body 38. Therefore, the connection of the main friction clutch 22 is released, and the transmission of the driving force between the outer case 14 and the inner case 17 is released.
See also Patent Document 1 below.
Japanese Patent Laid-Open No. 4-151031

  However, when the rotational speed of the front wheels is slower than the rotational speed of the rear wheels in a non-driven state in which the electromagnet 27 of the electromagnetic clutch mechanism 24 is not energized, the pilot may The friction clutch 26 may cause the inner plate to be dragged by the outer plate and rotate. In that case, for example, drag torque t in the direction shown in FIG. Due to the drag torque t, the torque amplified by the cam mechanism 23 (the main cam body 31, the spherical cam body 38, and the pilot cam body 32) is generated as the thrust S as in the case shown in FIG. 22 is connected, and an unintended driving force is transmitted between the outer case 14 and the inner case 17. Therefore, there is a problem that the transmission of the driving force when the driving force transmission device 1 is not driven is unstable.

  Therefore, in the driving force transmission device 1, the return spring 48 such as a disc spring that urges the main cam body 31 of the cam mechanism 23 on the outer periphery of the inner case 17 in the direction of the rotation center lines 14 a and 17 a so as to oppose the thrust S. The return spring 48 prevents the main friction clutch 22 from being connected. However, when this return spring 48 is adopted, there are the following problems *.

  * In order to reduce the rolling resistance of the needle bearing 35 that receives the pilot cam body 32 of the cam mechanism 23, it is necessary to reduce the elastic force of the return spring 48. Conversely, in order to prevent drag torque t caused by various causes such as oil viscosity increase at low temperatures, it is necessary to increase the elastic force of the return spring 48. Since they are contradictory events, it is impossible to lower the rolling resistance and at the same time prevent the drag torque t.

  * After the drag torque t generated in the pilot cam body 32 in the cam mechanism 23 is amplified and converted as the thrust S of the main cam body 31, the return spring 48 opposes the thrust S of the main cam body 31. Since the return spring 48 has an elastic force that urges the main cam body 31 in the direction of the rotation center lines 14 a and 17 a so as to oppose the thrust S, the pilot cam body 32 opposes the thrust S of the main cam body 31. The elastic force of the return spring 48 is received. Accordingly, the rolling resistance (friction resistance) of the needle bearing 35 that receives the pilot cam body 32 increases.

  * Not only in the non-driving state shown in FIG. 15 (d) but also in the driving state shown in FIGS. 15 (b) and 15 (c), the rotation center line 14a so that the elastic force of the return spring 48 opposes the main cam body 31 to the thrust S. , 17a. For this reason, the control of the driving force transmission device 1 in the driving state tends to become unstable due to the non-uniformity of the elastic force of the return spring 48 (a disc spring or the like).

  On the other hand, in the driving force transmission device 1, if the distance between the contact surfaces of the main friction clutch 22 is increased, the connection of the main friction clutch 22 is suppressed, so that it is possible to prevent the adverse effects associated with the generation of the drag torque t. it can. However, if this interval is increased, there is the following problem *.

  * In the cam mechanism 23, the inclination angles θ36 and θ37 with respect to the rotation direction R on the cam surface 36 of the main cam body 31 and the cam surface 37 of the pilot cam body 32 are applied to some extent in order to increase the thrust S by applying the lever principle. It is necessary to set a small value. However, when the interval is increased, the stroke of the main cam body 31 must be increased in the direction of the rotation centerlines 14a and 17a accordingly, and the rotation direction R of the cam surfaces 36 and 37 remains at the inclination angles θ36 and θ37. It is necessary to increase the length of the extension. For this reason, the rotation angle of the pilot cam body 32 becomes excessive, the responsiveness of the cam mechanism 23 deteriorates, and the formation and arrangement of the cam surfaces 36 and 37 become difficult.

  * When the interval is increased, the degree of freedom of each component such as the main cam body 31 is increased, and an unbalance such as eccentricity is likely to occur. Therefore, conventionally, unlike the actual usage state, the outer case 14 and the inner case 17 are rotated relative to each other without being energized while the electromagnet 27 of the electromagnetic clutch mechanism 24 is removed. As a result, the unbalance was confirmed. Therefore, each component member moved during the unbalance confirmation, and the unbalance could not be confirmed reliably.

  An object of the present invention is to reduce drag resistance (friction resistance) in a pilot cam body and a main cam body of a cam mechanism and at the same time prevent drag torque and improve drag resistance. Another object of the present invention is to reliably check the imbalance of the driving force transmission device.

The present invention will be described with reference to the drawings of the following embodiments (first embodiment shown in FIGS. 1 to 7 and second embodiment shown in FIGS. 8 to 14).
* Invention of Claim 1 (corresponding to the first and second embodiments)
The driving force transmission device (1) according to the invention of claim 1 is configured as follows.

The driving force transmission device (1) includes a main clutch (22) that transmits driving force between a first rotating member (12) and a second rotating member (15) that can rotate relative to each other, and a pilot clutch (26). ) and a clutch mechanism (24) for actuating the, and a cam mechanism (23) connecting the main clutch (22) during operation of the clutch mechanism connecting the pilot clutch (26) (24), said first rotary Generated in the main cam body (31) according to the torque (T) generated in the pilot cam body (32) via the pilot clutch (26) with relative rotation of the member (12) and the second rotating member (15). The main clutch (22) is connected by a thrust (S) in the direction of the rotation center line (14a, 17a) . The cam mechanism (23) includes a pilot cam body (32), a main cam body (31), a stopper body (33), a pilot cam body (32), a main cam body (31), and a stopper body ( 33) and to the each other initiative engaging locked to the rotation direction (R) and a biasing means (34) for biasing the stopper body (33). During the relative rotation in one direction between the first rotating member (12) and the second rotating member (15), the main cam body is caused by the relative rotation between the pilot cam body (32) and the main cam body (31). (31) is configured to generate a thrust (S) in the direction of the rotation center line (14a, 17a), and the pilot cam body (32) is rotated during relative rotation with the main cam body (31). The urging force by the urging means (34) is not generated in the direction. At the time of relative rotation in the other direction between the first rotating member (12) and the second rotating member (15), the stopper body (33) in which the biasing force (E) is generated by the biasing means (34) is generated. The relative rotation between the pilot cam body (32) and the main cam body (31) is restricted to suppress the thrust (S) in the direction of the rotation center line (14a, 17a) generated in the main cam body (31).

The biasing means is not limited to the torsion spring (34) according to the invention of claim 6 as long as it can generate a biasing force (E) in the rotational direction (R) on the stopper body (33). Other springs such as a tension coil spring and a compression coil spring may be employed. The torsion spring (34) may be a torsion coil spring having an increased number of turns in addition to a single notch ring (40). Although not shown, in addition to the invention of claim 6 below, one end (40a) of one notch ring (40) is supported by the pilot cam body (32) and supported by the pilot cam body (32). The other end (40b) of the notch ring (40) may be supported by the stopper body (33).
Further, in the first aspect of the invention, the following structure may be adopted (claim 2).
The stopper body is engaged with the main cam body and the pilot cam body when the relative rotation between the pilot cam body and the main cam body is restricted by the urging force of the urging means. A locking portion for restricting relative rotation between the stopper body and the biasing means for biasing the locking portion of the stopper body in a direction of engaging with the main cam body in the rotation direction; Is biased in the direction of engaging the pilot cam body in the rotational direction. In addition, during the relative rotation in one direction between the first rotating member and the second rotating member, the pilot cam body engages with the engaging portion of the stopper body in which the urging force is generated by the urging means in the rotation direction. Relative rotation with the main cam body is possible without matching.

The invention of claim 1 has the following effects *.
* Before the torque (drag torque t) generated in the pilot cam body (32) in the cam mechanism (23) is converted as the thrust (S) of the main cam body (31), the biasing means (34) stops the stopper body (33 The energizing force (E) generated on the pilot cam body (32) opposes the torque (drag torque t) of the pilot cam body (32), and therefore the thrust force (S) is received by the pilot cam body (32) and the main cam body (31). Suppress. Further, since the biasing means (34) has a biasing force (E) that biases the stopper body (33) in the rotational direction (R), the pilot cam body (32) and the main cam body (31) This urging means (34) does not receive the urging force in the direction of the rotation center line (14a, 17a). Furthermore, even if a return spring (48) similar to the prior art is added to further increase the stability of control, the function against the torque of the pilot cam body (32) (the drag torque t) is 33), the return spring (48) having a small elastic force can be used. Therefore, the rotational resistance (friction resistance) in the pilot cam body (32) and the main cam body (31) can be reduced regardless of the presence or absence of the return spring (48).

  * In the non-driving state shown in FIGS. 7 and 14, the torque (drag torque t) generated in the pilot cam body (32) is prevented from being converted as the thrust (S) of the main cam body (31). On the other hand, in the driving states shown in FIGS. 5 and 6 and FIGS. 12 and 13, the torque (T) generated in the pilot cam body (32) by the cam mechanism (23) is converted as the thrust (S) of the main cam body (31). Thus, the urging means (34) for urging the stopper body (33) in the rotation direction (R) is unlikely to have a direct adverse effect on the thrust (S) of the main cam body (31). Therefore, the control of the driving force transmission device (1) in the driving state can be stabilized.

  * Since the stopper body (33) biased in the rotational direction (R) by the biasing means (34) functions to prevent drag torque (t) caused by various causes such as oil viscosity increase at low temperatures, The rotational resistance (friction resistance) of the pilot cam body (32) and the main cam body (31) is not influenced by the biasing means (34), and the drag resistance (t) is prevented at the same time the rotation resistance (friction resistance) is lowered. It becomes possible to do.

* Inventions of claims 3 and 4 (corresponding to the second embodiment)
The invention of claim 3 is configured as follows on the premise of the invention of claim 1 or claim 2 .
Before SL main clutch (22) is a friction clutch, a non-connection state in which the spacing between the contact surfaces becomes a maximum value, the connection start state in which the drive force starts to increase its contact surface is transmitted in proximity And a connection state in which the distance between the contact surfaces is a minimum value and an intermediate state between these states. In the cam mechanism (23), the pilot cam body (32) and the main cam body (31) are provided with cam surfaces (36, 37) that sandwich the interlocking body (38). The cam surface (37) of the pilot cam body (32) and the cam surface (36) of the main cam body (31) are respectively the first stage cams that bring the main clutch (22) from the non-connected state to the connection start state. It is divided into a surface (50, 54) and a second stage cam surface (52, 56) that brings the main clutch (22) from the connection start state to the connection state.

The invention of claim 4 is configured as follows based on the invention of claim 3 .
In the cam mechanism (23), the main cam body (31) is supported so as to be rotatable relative to the first rotating member (12) and the second rotating member (15) and movable in the direction of the rotation center line (14a, 17a). ing. Regarding the cam surface (37) of the pilot cam body (32) with respect to the rotation direction (R), the cam surface (54) of the first stage is greater than the tilt angle (θ56) of the cam surface (56) of the second stage. The inclination angle (θ54) is set large. The inclination angle of the cam surface (36) of the main cam body (31) with respect to the rotation direction (R) is that of the first stage cam surface (50) relative to the inclination angle (θ52) of the second stage cam surface (52). The inclination angle (θ50) is set large.

In the third and fourth aspects of the invention, the first stage cam surface (50, 54) having a large inclination angle (θ50, θ54) functions from the disconnected state to the connected start state of the main clutch (22). Even if the extension length in the rotation direction (R) on the cam surfaces (50, 54) is reduced to reduce the rotation angle of the pilot cam body (32), the stroke of the main cam body (31) is reduced to the rotation center line (14a). 17a) to increase the responsiveness of the cam mechanism (23) and facilitate the formation and arrangement of the cam surfaces (36, 37). Further, since the second stage cam surface (52, 56) having a small inclination angle (θ52, θ56) functions from the connection start state to the connection state of the main clutch (22), the thrust (S) is the same as in the prior art. Can be increased. Therefore, by increasing the distance between the main clutches (22), it is possible to prevent adverse effects associated with the generation of drag torque (t). Incidentally, in the Japanese Patent Laid-Open 4-151031 discloses a clutch device meshing different cam surface of the cam angle shifts are disclosed by deflection of the disc spring by the thrust force, with the invention of claim 3 and 4, the main clutch The first stage cam surface (50, 54) that changes (22) from the non-connected state to the connection start state and the second stage cam surface (52, 54) that changes the main clutch (22) from the connection start state to the connected state. 56), which is different from JP-A-4-151031.

* Invention of claim 5 (corresponding to the second embodiment)
In the cam mechanism (23) according to the invention of claim 5 based on the invention of any one of claims 1 to 4 , torque (T, t) generated in the pilot cam body (32) Accordingly, a return spring (48) for urging the main cam body (31) is provided so as to oppose the thrust (S) in the direction of the rotation center line (14a, 17a) generated in the main cam body (31).

In the fifth aspect of the invention, the positions of the main cam body (31), the pilot cam body (32), and the stopper body (33) are fixed by the elastic force of the return spring (48) in a state where no thrust (S) is generated. The generated torque (T) can be stabilized.

* Invention of Claim 6 (corresponding to the first and second embodiments)
The invention of claim 6 is configured as follows based on the invention of any one of claims 1 to 5 .

  The biasing means is a torsion spring (34). One end (40a) of the torsion spring (34) is supported by the main cam body (31), and the torsion spring (34) The other end (40b) is supported by the stopper body (33). For example, the torsion spring (34) is composed of one notch ring (40) in which a bending allowance space (39) is notched between one end (40a) and the other end (40b).

In the invention of claim 6, the biasing means good and simple structure uniformity of elasticity than the disc spring (torsion spring 34, such as a notch ring 40), of the claims 1 to 5 The effect of the invention of any claim can be exhibited.

* Invention of Claim 7 (corresponding to the first and second embodiments)
In the invention of claim 7 based on the invention of claim 6, the stopper body (33) and the torsion spring (34) are assembled to the main cam body (31), and the stopper body (33) A restricting body (for example, a snap ring 45) that restricts movement of the main cam body (31) in the direction of the rotation center line (14a, 17a) is attached to the main cam body (31), and the stopper body (33) and the screw are tightened. The torsion spring (34) and the restricting body (45) can move together with the main cam body (31) in the direction of the rotation center line (14a, 17a).

According to the seventh aspect of the present invention, even if the movement stroke of the main cam body (31) is increased when the interval of the main clutch (22) is increased in order to prevent the adverse effects associated with the generation of the drag torque (t), the stopper Since the body (33) and the torsion spring (34) move integrally with the main cam body (31), they can be firmly assembled to prevent inadvertent disassembly. Further, since the assembly unit (U) in which the main cam body (31), the stopper body (33), and the torsion spring (34) are integrated, and the pilot cam body (32) are assembled, the cam mechanism (23) Assembling property can be improved.

* Invention of claim 8 (corresponding to the second embodiment)
According to an eighth aspect of the invention based on the seventh aspect, one end (40a) of the torsion spring (34) is provided on the main cam body (31) with the elasticity of the torsion spring (34). A locking portion (61) that is pressed against the force (E) is provided, and the other end (40b) of the torsion spring (34) is connected to the torsion spring (33). 34) is provided with a locking portion (62) pressed against the elastic force (E), and the main cam body (31) is provided with a torsion spring (61) to the locking portion (61) of the main cam body (31). An opening (63) corresponding to the other end (40b) of the torsion spring (34) is provided in a state where the one end (40a) of 34) is supported.

In the invention of claim 8 , a jig (not shown) is inserted into the opening (63) of the main cam body (31), and one end (40a) and the other end (40b) of the torsion spring (34). Can be expanded to each other, so that the assembling property of the cam mechanism (23) can be improved.

* Invention of Claim 9 (corresponding to the second embodiment)
The invention of claim 9, the driving force transmitting device according to the invention of 請 Motomeko 1 (1), a method of confirming the unbalance, when performing the unbalance check, the first rotary member (12) first The electromagnet (27) or the electromagnet substitute component of the electromagnetic clutch mechanism (24) is energized while the two-rotating member (15) is rotatably supported.

In the invention of claim 9 , since the unbalance of the driving force transmission device (1) is confirmed in a state similar to the actual use state, the main friction clutch (in order to prevent adverse effects caused by the generation of the drag torque (t) 22) When the interval of 22) is expanded, the degree of freedom of each component (for example, the main cam body 31) becomes large, and even when the unbalance such as the eccentricity is likely to occur, the confirmation of the unbalance such as the eccentricity is ensured. Can go to prevent imbalance.

  The present invention reduces the rotational resistance (friction resistance) in the pilot cam body (32) and the main cam body (31) of the cam mechanism (23) and at the same time prevents drag torque (t) and improves drag resistance performance. it can. Moreover, this invention can perform unbalance confirmation of a driving force transmission device (1) reliably.

[First embodiment]
First, a driving force transmission device according to a first embodiment of the present invention will be described with reference to FIGS.

  In the four-wheel drive vehicle schematically shown in FIG. 1, the driving force transmission device 1 also shown in FIGS. 2 and 3 is an electronically controlled torque transmission device that generates torque according to the current applied to the electromagnet 27. Used in drive-based four-wheel drive vehicles. The driving force transmission device 1 is connected to a rear differential 3 via a drive pinion shaft 2 and is supported by a differential carrier 4 that accommodates the rear differential 3 and is attached to a vehicle body. The driving force of the engine 5 is output to the axle shaft 7 via the transaxle 6 to drive both front wheels 8. The transaxle 6 is connected to the driving force transmission device 1 through a propeller shaft 9. When the propeller shaft 9 and the drive pinion shaft 2 are coupled so that torque can be transmitted by the driving force transmission device 1, the driving force of the engine 5 is transmitted from the rear differential 3 to both rear wheels 11 via the axle shaft 10. Communicated.

  The first rotating member 12 includes an outer case 14 connected to the propeller shaft 9 that is linked to a driving system on the front wheel 8 side that is a driving wheel. The second rotating member 15 includes an inner case 17 connected to the drive pinion shaft 2 that is interlocked with a drive system on the rear wheel 11 side that is a driven wheel. The outer case 14 includes an outer front housing 18 and an inner rear housing 19, and can rotate relative to the inner case 17 about the same rotation center line 14 a as the rotation center line 17 a of the inner case 17. A rear housing chamber 20 is provided in the rear housing 19 in the entire circumferential direction of the inner case 17. Between the inner case 17, the front housing 18 and the rear housing 19, a front storage chamber 21 is provided in the entire circumferential direction of the inner case 17 in a closed state. Lubricating oil and air are enclosed in the front housing chamber 21, and a main friction clutch 22 and a cam mechanism 23 are built in. An armature 25 and a pilot friction clutch 26 of the electromagnetic clutch mechanism 24 are provided. Built in. An electromagnet 27 and a yoke 28 of the electromagnetic clutch mechanism 24 are fitted in the rear housing chamber 20 in the rear housing 19.

  The main friction clutch 22 is a multi-plate clutch and includes a plurality of outer plates 29 and a plurality of inner plates 30. Each outer plate 29 is splined to the inner periphery of the front housing 18 of the outer case 14 and is juxtaposed in the direction of the rotation center line 14a of the outer case 14 so as to rotate integrally with the outer case 14 and to the outer case 14. On the other hand, it can move relatively in the direction of the rotation center line 14a. The inner plates 30 are spline-coupled to the outer periphery of the inner case 17 and are arranged in parallel in the direction of the rotation center line 17a of the inner case 17 alternately with the outer plates 29. It can move relative to the case 17 in the direction of the rotation center line 17a.

  As shown in FIG. 4, the cam mechanism 23 has a main cam body 31, a pilot cam body 32, a stopper body 33 and a stopper body 33 that can be rotated relative to each other about the rotation center lines 14 a and 17 a, and the stopper body 33 in the rotation direction R. And a torsion spring 34 (biasing means) for biasing. The main cam body 31 is juxtaposed in the direction of the rotation center lines 14 a and 17 a adjacent to the main friction clutch 22. The pilot cam body 32 is arranged in parallel with the rear housing 19 via a needle bearing 35 in the direction of the rotation center lines 14a and 17a. The pilot cam body 32 is supported by a needle bearing 35, is rotatable relative to the inner case 17 and the outer case 14, and is restricted from moving in the direction of the rotation center lines 14a and 17a. The main cam body 31 is spline-coupled to the outer periphery of the inner case 17 and can rotate integrally with the inner case 17 and can press the inner plate 30 of the main friction clutch 22.

  In the cam mechanism 23, a plurality of cam surfaces 36, 37 are formed on the main cam body 31 and the pilot cam body 32 in the vicinity of the outer periphery of the inner case 17 so as to face each other, and the rotation center lines 14a, 17a are the center. They are arranged in the rotation direction R at equal intervals. A spherical cam body 38 (interlocking body) is fitted between the cam surfaces 36 and 37 of each set so as to come into contact with the cam surfaces 36 and 37. The cross-sectional shape cut | disconnected in the rotation direction R in these cam surfaces 36 and 37 is a shape which piled up a pair of semiconical surface in the rotation direction R on the bottom side. The radii of the inner circular arc surfaces of the cam surfaces 36 and 37 are substantially equal to each other, and are also set to be approximately equal to the radius of the outer peripheral spherical surface of the spherical cam body 38.

  The torsion spring 34 is composed of a notch ring 40 in which a bending allowance space 39 is notched between one end 40a and the other end 40b. The notch ring 40 is supported by the main cam body 31. The shaft portion 31a of the main cam body 31 is inserted into the locking hole 34a of the one end portion 40a of the notch ring 40 in a state where the bending allowance space 39 of the notch ring 40 is widened, and the notch ring 40 The shaft portion 33a of the stopper body 33 is inserted into the locking hole 34b of the other end portion 40b. Therefore, the notch ring 40 has a rotational elasticity that narrows the bending allowance space 39.

  The stopper body 33 has locking projections 41 and 42 (locking portions), and the main cam body 31 and the pilot cam body 32 have locking protrusions 43 and 44 (locking portions), respectively. . The locking projection 41 of the stopper body 33 and the locking projection 43 of the main cam body 31 are urged toward each other by the elastic force E of the notch ring 40 and the stopper body 33 is locked. The protrusion 42 and the locking protrusion 44 of the pilot cam body 32 are urged so as to approach each other.

  The main cam body 31 is attached with a snap ring 45 (regulator body) that restricts the stopper body 33 from moving from the main cam body 31 by moving in the direction of the rotation center lines 14a and 17a.

  The armature 25 of the electromagnetic clutch mechanism 24 is fitted between the main cam body 31 and the rear housing 19 on the outer periphery of the pilot cam body 32. The armature 25 is splined to the inner periphery of the front housing 18 and can rotate integrally with the outer case 14 and can move in the direction of the rotation center line 14 a of the outer case 14. The pilot friction clutch 26 of the electromagnetic clutch mechanism 24 includes three outer plates 46 and two inner plates 47, and is fitted between the armature 25 and the rear housing 19 on the outer periphery of the pilot cam body 32. It is. The three outer plates 46 are splined to the inner periphery of the front housing 18 and can rotate together with the outer case 14 and can move in the direction of the rotation center line 14 a of the outer case 14. The two inner plates 47 are splined to the outer periphery of the pilot cam body 32 between the three outer plates 46 and can rotate together with the pilot cam body 32 and move in the direction of the rotation center line 17a of the inner case 17. Can do.

  When the electromagnet 27 is energized by the electromagnetic clutch mechanism 24, a magnetic path M schematically shown by a broken line in FIG. Due to the generation of the magnetic path M, when the armature 25 is attracted by the electromagnet 27 and the pilot friction clutch 26 is in frictional contact, the pilot cam body 32 can rotate in the rotation direction R of the outer case 14 in the cam mechanism 23. When relative rotation occurs between the outer case 14 that rotates integrally with the propeller shaft 9 and the inner case 17 that rotates integrally with the drive pinion shaft 2, torque is applied to the pilot cam body 32 by frictional contact of the pilot friction clutch 26. appear. For example, when the torque T in the direction shown in FIG. 5 is generated in the pilot cam body 32 during forward drive, the locking projection 41 of the stopper body 33 is applied to the locking projection 43 of the main cam body 31 by the elastic force E of the notch ring 40. The locking projection 44 of the pilot cam body 32 is separated from the locking projection 42 of the stopper body 33 by approaching and substantially contacting. Further, for example, when the torque T in the direction shown in FIG. 6 is generated in the pilot cam body 32 during reverse drive or engine braking, if the torque T is greater than the elastic force E of the notch ring 40, the pilot cam body 32. The locking projection 44 presses the locking projection 42 of the stopper body 33 in the direction of the torque T. Therefore, the locking projection 41 of the stopper body 33 is separated from the locking projection 43 of the main cam body 31. In any driving state, the spherical cam body 38 contacts the cam surfaces 36 and 37 provided between the pilot cam body 32 and the main cam body 31 that rotates integrally with the inner case 17. As a result, the main friction clutch connection state P is reached, and a thrust S in the direction of the rotation center lines 14a and 17a is generated in the main cam body 31 due to the relative rotation generated between the pilot cam body 32 and the main cam body 31. In accordance with the thrust S, the main friction clutch 22 is connected, and driving force is transmitted between the outer case 14 that rotates integrally with the propeller shaft 9 and the inner case 17 that rotates integrally with the drive pinion shaft 2. Is called. Note that the attraction force changes according to the value of the applied current to the electromagnet 27, and the torque T of the cam mechanism 23 also changes to adjust the transmission driving force.

  On the other hand, in the non-driven state where the electromagnet 27 is not energized in the electromagnetic clutch mechanism 24, the magnetic path M described above is not generated around the electromagnet 27, and the attraction of the electromagnet 27 to the armature 25 is released. Then, the pilot friction clutch 26 causes relative rotation between the outer plate 46 and the inner plate 47, and the pilot cam body 32 and the main cam body 31 rotate integrally with each other via the spherical cam body 38 in the cam mechanism 23. In this case, for example, even if the drag torque t in the direction shown in FIG. 7 is generated in the pilot cam body 32 due to various reasons such as oil viscosity increase at low temperatures, the drag torque t is larger than the elastic force E of the notch ring 40. When it is small, the locking projection 42 of the stopper body 33 opposes the locking projection 44 of the pilot cam body 32. Therefore, the thrust generation suppression state Q is entered regardless of the generation of the drag torque t. Accordingly, the pilot cam body 32 and the main cam body 31 are integrally rotated, the connection of the main friction clutch 22 is released, the outer case 14 that rotates integrally with the propeller shaft 9, and the inner case that rotates integrally with the drive pinion shaft 2. The transmission of the driving force to and from 17 is released.

[Second Embodiment]
Next, a driving force transmission device according to a second embodiment of the present invention will be described with reference to FIGS. This second embodiment is mainly different from the first embodiment in the following * points. 2, 3, 4, 5, 6, and 7 in the first embodiment correspond to FIGS. 8, 10, 11, 12, 13, and 14 in the second embodiment, respectively.

* Attaching the return spring 48 in the cam mechanism 23 The return spring 48 is a disc spring, and is inserted into the outer peripheral portion of the inner case 17 inside the main cam body 31, and is in pressure contact with the main cam body 31. When the electromagnet 27 is not energized, the main cam body 31 is urged toward the pilot cam body 32 in a direction parallel to the rotation center lines 14a and 17a by the elastic force of the return spring 48. The main cam body 31 causes the pilot cam body 32 to be spherical. The pilot cam body 32 is pressed against the needle bearing 35 which is pushed through the cam body 38 and supported by the rear housing 19.

  When the electromagnet 27 is energized, there is no degree of freedom in which the main cam body 31, the pilot cam body 32, and the stopper body 33 can move in the directions of the rotation center lines 14a and 17a. If the distance between the contact surfaces of the main friction clutch 22 is increased in order to improve drag resistance, this degree of freedom increases when the electromagnet 27 is not energized. In the first embodiment, since the return spring 48 is not employed, the positions of the main cam body 31, the pilot cam body 32, and the stopper body 33 are set within the range of their degrees of freedom when the electromagnet 27 is not energized. When the electromagnet 27 is energized and de-energized repeatedly, the generated torque T may become unstable.

  In the second embodiment, since the return spring 48 that can counter the thrust S is employed, the main cam body 31, the pilot cam body 32, and the stopper body 33 are connected to the return spring 48 and the needle bearing 35 when the electromagnet 27 is not energized. They are sandwiched between (supporting portions) and their positions are fixed. Therefore, the generated torque T is stabilized when the electromagnet 27 is energized and de-energized repeatedly. Incidentally, since the stopper body 33 functions to counteract the torque of the pilot cam body 32 (the drag torque t), the return spring 48 has a small elastic force to reduce the rolling resistance with the needle bearing 35. can do.

* Improvement of the cam surfaces 36 and 37 of the main cam body 31 and the pilot cam body 32 The cam surface 36 of the main cam body 31 is inclined with respect to the rotation direction R and the arcuate first cam surface 36a inclined with respect to the rotation direction R. In addition, it has an arcuate second cam surface 36b having an inclination direction opposite to the inclination direction of the first cam surface 36a. The cam surface 37 of the pilot cam body 32 also has an arcuate first cam surface 37a inclined with respect to the rotation direction R, and an inclination direction that is inclined with respect to the rotation direction R and opposite to the inclination direction of the first cam surface 37a. And an arcuate second cam surface 37b.

  A first-stage pressure contact surface 50 extending from a boundary portion 49 between the first cam surface 36a and the second cam surface 36b is respectively formed on the first cam surface 36a and the second cam surface 36b of the cam surface 36 of the main cam body 31. And a second-stage pressure contact surface 52 extending from the boundary portion 51 with the first-stage pressure contact surface 50 are formed separately from each other. On the first cam surface 37a and the second cam surface 37b of the cam surface 37 of the pilot cam body 32, a first-stage pressure contact surface extending from the boundary portion 53 between the first cam surface 37a and the second cam surface 37b, respectively. 54 and a second-stage pressure contact surface 56 extending from a boundary portion 55 between the first-stage pressure contact surface 54 and the first-stage pressure contact surface 54 are formed separately from each other. The inclination angle of the first cam surface 36a and the second cam surface 36b of the cam surface 36 of the main cam body 31 with respect to the rotation direction R is higher than the inclination angle θ52 (<θ50) of the second-stage pressure contact surface 52. The inclination angle θ50 (> θ52) is set large. The inclination angle of the first cam surface 37a and the second cam surface 37b of the cam surface 37 of the pilot cam body 32 with respect to the rotation direction R is greater than the inclination angle θ56 (= θ52 <θ54) of the second-stage pressure contact surface 56. The inclination angle θ54 (= θ50> θ56) of the one-stage pressure contact surface 54 is set large. The boundary portions 51 and 55 between the first-stage pressure contact surfaces 50 and 54 and the second-stage pressure contact surfaces 52 and 56 are appropriately rounded.

  The switching position of the inclination angle is determined in the transition from the disconnected state where the distance between the outer plate 29 and the inner plate 30 of the main friction clutch 22 is maximum to the connected state where the distance is minimum. , 30 are set at positions where the driving force transmitted in close proximity begins to increase (positions in the connection start state). That is, the spherical cam body 38 moves along the first-stage pressure contact surfaces 50 and 54 having a relatively large inclination angle from the non-connection state to the connection start state, and the inclination angle is relatively small from the connection start state to the connection state. The spherical cam body 38 moves along the small second-stage pressure contact surfaces 52 and 56. Therefore, the spherical cam body 38 and the main cam body 31 move quickly until the distance between the outer plate 29 and the inner plate 30 becomes almost zero, and thereafter, the main cam body 31 moves these plates 29 and 30 by a large thrust. Move in the direction of pressure contact.

Note that the inclination angles θ50 and θ54 of the first-stage pressure contact surfaces 50 and 54 and the inclination angles θ52 and θ56 of the second-stage pressure contact surfaces 52 and 56 may be set to a plurality of inclination angles.
* Assembly of the stopper body 33 and the torsion spring 34 to the main cam body 31 The main cam body 31 includes a boss wall portion 57 into which the inner case 17 is inserted, and an end wall extending in the radial direction from the outer peripheral portion of the boss wall portion 57. Part 58, an outer peripheral wall part 59 projecting from the outer peripheral part of the end wall part 58 so as to face the boss wall part 57, and a storage chamber formed between the outer peripheral wall part 59 and the boss wall part 57 60. The stopper body 33 and the torsion spring 34 are fitted in the accommodation chamber 60 of the main cam body 31, and are assembled so as to be relatively rotatable with respect to the main cam body 31 and to be movable in the directions of the rotation center lines 14a and 17a. The torsion spring 34 is sandwiched between the end wall portion 58 of the main cam body 31 and the stopper body 33. A hole snap ring 45 (regulator) is fitted into the outer peripheral wall portion 59 of the main cam body 31. The snap ring 45 sandwiches the stopper body 33 and the torsion spring 34 between the end wall portion 58 of the main cam body 31, and the stopper body 33 and the torsion spring 34 rotate relative to the main cam body 31. , 17a is restricted. The stopper body 33, the torsion spring 34, and the snap ring 45 can move together with the main cam body 31 in the directions of the rotation center lines 14a and 17a. Each cam surface 36 and the locking projection 43 are formed on the boss wall 57 of the main cam body 31. The above points are the same in the case of the first embodiment.

  In the first embodiment, the shaft portion 31 a protruding from the end wall portion 58 of the main cam body 31 is inserted into the locking hole 34 a of the one end portion 40 a of the notch ring 40 in the torsion spring 34, and The shaft portion 33 a of the stopper body 33 is inserted into the locking hole 34 b of the other end portion 40 b of the notch ring 40. Instead of this configuration, one end portion 40a of the notch ring 40 is pressed against the elastic force E against a locking step portion 61 (locking portion) formed on the boss wall portion 57 of the main cam body 31, and the stopper The other end portion 40b of the notch ring 40 is pressed against the elastic force E against a locking step portion 62 (locking portion) formed on the body 33.

  An opening 63 is formed in the outer peripheral wall portion 59 of the main cam body 31 in the vicinity of the locking step portion 61 of the main cam body 31. When assembling the cam mechanism 23, first, the torsion spring 34 is fitted into the housing chamber 60 of the main cam body 31, and the one end portion 40a of the notch ring 40 is brought into pressure contact with the locking step portion 61. A jig (not shown) is inserted from the opening 63 to widen the other end 40b of the notch ring 40 with respect to the one end 40a. Next, the stopper body 33 is also fitted into the housing chamber 60 of the main cam body 31, and a jig (not shown) is removed from the opening 63 so that the other end 40 b of the notch ring 40 is also brought into pressure contact with the locking step 62. In this way, the pilot cam body 32 is assembled to the assembly unit U in which the main cam body 31, the stopper body 33, and the torsion spring 34 are integrated. Incidentally, the opening 63 is also used as a hole for circulating the lubricating oil.

* Method for confirming the unbalance of the driving force transmission device 1 When confirming the unbalance of the driving force transmission device 1, first, the first rotating member 12 and the second rotating member 15 are rotated by the jig 64 indicated by a two-dot chain line. Support as possible. Next, in the supporting state, the first rotating member 12 and the second rotating member 15 are relatively rotated, and the electromagnet 27 or the electromagnet substitute component of the electromagnetic clutch mechanism 24 is energized so that the driving force transmission device 1 Generate torque. That is, the imbalance of the driving force transmission device 1 is confirmed in a state where the positional freedom of each member constituting the pilot friction clutch 26, the main friction clutch 22, and the cam mechanism 23 is limited. The electromagnet substitute component is a test component that brings the pilot friction clutch 26 into a connected state by the magnetic force of a permanent magnet, for example.

  In the first embodiment and the second embodiment described above, the driving force transmission device for a four-wheel drive vehicle has been described. However, the present invention is not limited to this, and is also applicable to a torque transmission mechanism between two shafts such as a starting clutch. Is possible.

It is the schematic which shows the drive system of a four-wheel drive vehicle. It is sectional drawing which shows the driving force transmission apparatus concerning 1st embodiment. FIG. 3 is a partially enlarged sectional view of FIG. 2. FIG. 4 is a partially omitted reference perspective view showing an exploded state of the cam mechanism of FIG. 3. (A) and (b) are operation | movement explanatory drawings of the cam mechanism shown in FIG. (A) and (b) are operation | movement explanatory drawings of the cam mechanism shown in FIG. (A) and (b) are operation | movement explanatory drawings of the cam mechanism shown in FIG. It is sectional drawing which shows the driving force transmission apparatus concerning 2nd embodiment. FIG. 11 is a partial plan view showing a state where the cam mechanism of FIG. 10 is being assembled. It is a partial expanded sectional view of FIG. FIG. 10 is a partially omitted reference perspective view showing an exploded state of the cam mechanism of FIG. 9. (A) and (b) are operation | movement explanatory drawings of the cam mechanism shown in FIG. (A) and (b) are operation | movement explanatory drawings of the cam mechanism shown in FIG. (A) and (b) are operation | movement explanatory drawings of the cam mechanism shown in FIG. (A) is sectional drawing which shows the conventional driving force transmission apparatus, (b) (c) (d) is an effect | action explanatory drawing of the conventional cam mechanism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Driving force transmission device, 12 ... 1st rotation member, 14a ... Rotation center line, 15 ... 2nd rotation member, 17a ... Rotation center line, 22 ... Main friction clutch (main clutch), 23 ... Cam mechanism, 24 ... Electromagnetic clutch mechanism (clutch mechanism), 26 ... pilot friction clutch (pilot clutch), 27 ... electromagnet, 31 ... main cam body, 32 ... pilot cam body, 33 ... stopper body, 34 ... torsion spring (biasing means) 36, 36a, 36b ... cam surface, 37, 37a, 37b ... cam surface, 38 ... spherical cam body (interlocking body), 40a ... one end, 40b ... other end, 41, 42, 43, 44 ... locking Projection (locking portion), 45 ... Snap ring (regulator), 48 ... Return spring, 50, 54 ... First stage pressure contact surface, 52,56 ... Second stage pressure contact surface, 61,62 ... Locking step Department (person Part) 63 ... opening, E ... elastic force, P ... main friction clutch connected state, Q ... thrust generation restrained state, T ... torque, S ... thrust, t ... drag torque, θ50, θ52, θ54, θ56 ... inclination angle .

Claims (9)

The main clutch that transmits a driving force between the first rotating member and the second rotating member that can rotate relative to each other, a clutch mechanism that operates the pilot clutch, and a clutch mechanism that connects the pilot clutch are operated when the main clutch is operated. And a cam mechanism that connects the first rotating member and the second rotating member in the direction of the rotation center line generated in the main cam body in response to the torque generated in the pilot cam body via the pilot clutch with relative rotation of the first rotating member and the second rotating member. In the driving force transmission device configured to connect the main clutch by thrust,
The cam mechanism includes a pilot cam body, a main cam body, and a stopper body that can rotate relative to each other, and an urging means that urges the stopper body in a rotational direction that locks the pilot cam body, the main cam body, and the stopper body. With
At the time of relative rotation in one direction between the first rotating member and the second rotating member, the main cam body generates thrust in the direction of the rotation center line due to the relative rotation between the pilot cam body and the main cam body. In addition, the pilot cam body is configured so that the biasing force by the biasing means is not generated in the rotation direction at the time of relative rotation with the main cam body,
At the time of relative rotation in the other direction between the first rotating member and the second rotating member, the stopper body in which the biasing force is generated by the biasing means restricts the relative rotation between the pilot cam body and the main cam body. Thus, the thrust in the direction of the rotation center line generated in the main cam body is suppressed.
A driving force transmission device characterized by that. The stopper body is engaged with the main cam body and the pilot cam body when the relative rotation between the pilot cam body and the main cam body is restricted by the urging force of the urging means. A locking portion for restricting relative rotation between the stopper body and the biasing means for biasing the locking portion of the stopper body in a direction of engaging with the main cam body in the rotation direction; Urging the engaging part of the
At the time of relative rotation in one direction between the first rotating member and the second rotating member, the pilot cam body engages with a locking portion of the stopper body in which the biasing force is generated by the biasing means in the rotation direction. Relative rotation with the main cam body without
The driving force transmission device according to claim 1. The main clutch is a friction clutch, in a non-connected state in which the distance between the contact surfaces reaches a maximum value, a connection start state in which the driving force transmitted in close proximity to the contact surfaces starts to increase, and the contact Take the connection state where the distance between the surfaces is the minimum value and the intermediate state between these states,
In the cam mechanism, the pilot cam body and the main cam body are provided with cam surfaces that sandwich the interlocking body, and the cam surface of the pilot cam body and the cam surface of the main cam body start the connection of the main clutch from the disconnected state, respectively. It is divided into a first-stage pressure contact surface for bringing the main clutch into a state and a second-stage pressure contact surface for bringing the main clutch from the connection start state to the connection state.
The driving force transmission device according to claim 1 or 2, wherein In the cam mechanism, the main cam body is supported so as to be rotatable relative to the first rotating member and the second rotating member and movable in the direction of the rotation center line,
The inclination angle of the pilot cam body with respect to the rotational direction is set to be greater than the inclination angle of the first stage pressure contact surface than the second stage pressure contact surface,
For the cam surface of the main cam body, the tilt angle of the first stage pressure contact surface is set larger than the tilt angle of the second stage pressure contact surface with respect to the rotation direction.
The driving force transmission device according to claim 3. 2. The cam mechanism according to claim 1, further comprising a return spring that biases the main cam body so as to oppose a thrust in a rotation center line direction generated in the main cam body in accordance with a torque generated in the pilot cam body. The driving force transmission device according to any one of claims 1 to 4. The biasing means is a torsion spring, and one end of the torsion spring is supported by the main cam body, and the other end of the torsion spring is supported by the stopper body. The driving force transmission device according to any one of claims 1 to 5. The stopper body and the torsion spring are assembled to the main cam body, and a restricting body for restricting the stopper body from moving in the direction of the rotation center line with respect to the main cam body is attached to the main cam body. 7. The driving force transmission device according to claim 6, wherein the torsion spring and the regulating body can move integrally with the main cam body in the direction of the rotation center line. The main cam body is provided with a locking portion where one end of the torsion spring is pressed against the elastic force of the torsion spring, and the other end of the torsion spring is provided on the stopper body. Is provided with a locking portion that is pressed against the elastic force of the torsion spring, and the main cam body has an end portion of the torsion spring supported by the locking portion of the main cam body. The driving force transmission device according to claim 7, wherein an opening corresponding to the other end is provided. The main clutch that transmits a driving force between the first rotating member and the second rotating member that can rotate relative to each other, a clutch mechanism that operates the pilot clutch, and a clutch mechanism that connects the pilot clutch are operated when the main clutch is operated. And a cam mechanism that connects the first rotating member and the second rotating member in the direction of the rotation center line generated in the main cam body in response to the torque generated in the pilot cam body via the pilot clutch with relative rotation of the first rotating member and the second rotating member. A driving force transmission device configured to connect the main clutch by thrust,
The cam mechanism includes a pilot cam body, a main cam body, and a stopper body that can rotate relative to each other, and an urging means that urges the stopper body in a rotational direction that locks the pilot cam body, the main cam body, and the stopper body. With
At the time of relative rotation in one direction between the first rotating member and the second rotating member, the main cam body generates thrust in the direction of the rotation center line due to the relative rotation between the pilot cam body and the main cam body. In addition, the pilot cam body is configured so that the biasing force by the biasing means is not generated in the rotation direction at the time of relative rotation with the main cam body,
At the time of relative rotation in the other direction between the first rotating member and the second rotating member, the stopper body in which the biasing force is generated by the biasing means restricts the relative rotation between the pilot cam body and the main cam body. And suppress the thrust in the direction of the rotation center line generated in the main cam body,
The main clutch is a main friction clutch, the pilot clutch is a pilot friction clutch, and the clutch mechanism is an electromagnetic clutch mechanism.
A driving force transmission device characterized in that an electromagnet or an electromagnet substitute part of an electromagnetic clutch mechanism is energized in a state where the first rotating member and the second rotating member are rotatably supported when the unbalance is confirmed. Unbalance check method.

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