JP5289025B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device.

  Patent Document 1 describes a “driving force transmission device”.

  The driving force transmission device sucks an armature by a main clutch in which an outer plate and an inner plate are splined to an outer rotating member and an inner rotating member, a pilot clutch splined to an outer rotating member and a cam ring, and an armature, respectively. The electromagnet for fastening the pilot clutch and the differential clutch between the outer rotating member and the inner rotating member are operated when the pilot clutch is fastened, and the pressure ring connected to the inner rotating member by the spline is pressed. And a cam mechanism (ball cam) for fastening the main clutch.

  Such a power transmission device is used, for example, in a four-wheel drive vehicle with a rear wheel drive base, and the outer rotating member is connected to the rear wheel side and the inner rotating member is connected to the front wheel side. When this four-wheel drive vehicle is traveling with the main clutch engaged, the outer rotating member rotates ahead of the inner rotating member during straight traveling, but when turning begins, the rear wheel side and the front wheel side Due to the difference in the turning radius, the rotation speed of the inner rotation member becomes larger than the rotation speed of the outer rotation member, and the inner rotation member overtakes the outer rotation member and tries to rotate in advance. At this time, the cam from the inner rotation member and the outer rotation member The direction of torque applied to the mechanism is reversed. Such reversal of the outer rotating member and the inner rotating member can cause the four-wheel drive vehicle configured to transmit the driving force on the front wheel side to the rear wheel side via the power transmission device from the forward travel to the reverse travel. This occurs even when switching from reverse travel to forward travel, and accompanying this, noise called “buzzing” is generated. This noise is considered to be caused by the cam thrust force remaining in the cam mechanism during reverse rotation.

  In the driving force transmission device disclosed in Patent Document 1, the rotation direction clearance L4 (rotational backlash amount) of the spline portion that connects the inner rotating member and the pressure ring is connected to the inner rotating member and the inner clutch inner plate. This noise is reduced by reducing the remaining cam thrust force as shown in each time chart of FIG. 4 by setting it smaller than the rotation direction gap L5 (rotational backlash amount) of the spline portion.

  The broken line in FIG. 4 shows the change (effect) caused by making L4 smaller than L5, and time chart (2) shows that the attractive force of the armature by the electromagnet is constant (the main clutch is in the engaged state). The range indicated as reverse in the time chart (1) showing the phase change of the inner rotating member is the range until the inner rotating member accelerates and precedes the outer rotating member as the vehicle turns, A range indicated as normal rotation indicates a range from the time when the vehicle returns to straight traveling, the outer rotating member accelerates again, and the preceding rotating operation before the inner rotating member.

  When the inner rotating member starts accelerating in this way along with turning, the backlash starts and ends at the spline portion between the inner rotating member and the inner plate as shown in the time chart (3) from time point a to time point b. At the same time, the backlash filling starts and ends at the spline portion between the inner rotating member and the pressure ring as shown from the time point e to the time point f in the time chart (5). As shown in the chart (4), from the time point c to the time point d, the backlash starts and ends at the spline portion between the outer rotating member and the outer plate. Further, with the rotation of the pressure ring in the time chart (5), the cam surface formed on the pressure ring rotates as in the time chart (6), and from the time point g in the operating state to the time point h in the neutral position. The transition is made and after the time point i at which the cam surface and the ball start to come into contact again, the time point j is reached. The time chart (7) shows the change over time of the cam thrust force F generated by the cam mechanism, and the cam thrust force F starts to decrease at the time point k corresponding to the time point g (operating state) of the time chart (6). The cam thrust force F becomes zero (0) at a time point l corresponding to a time point h (neutral position) in (6). The time chart (8) shows the change with time of the torque generated in the main clutch. At the time point (d) when the play on the outer plate side is finished in the time chart (4), the torque m still remains. It is considered that the above-mentioned sound is generated by the residual torque (cuttering torque: hail torque) m.

In the driving force transmission device of Patent Document 1, L4 (the amount of rotation backlash between the inner rotating member and the pressure ring) is made smaller than L5 (the amount of rotation backlash between the inner rotating member and the inner plate) as described above. In the chart (5), the end point f of the backlashing is promoted to the time point f1, and accordingly, in the time chart (7), the decrease start of the cam thrust force F of the cam mechanism is promoted from the time point k to the time point k1. In 8), the residual torque is reduced to a residual torque n smaller than the conventional residual torque m, and the noise is reduced accordingly.
JP 2002-188656 A

  However, since the spline portion formed between the inner rotary member and the inner plate and the pressure ring has a small diameter, the small back spline portion (L4 and L5) ), It is extremely difficult to manage the dimensions of the spline portions of the inner rotating member, inner plate, and pressure ring, which increases processing costs and management costs, and even if the folding angles, L4 and L5 are processed to set values. The dimensions change over time due to the load applied during operation, the residual torque increases, and the effect of reducing the noise is impaired.

  In particular, in the case of a pressure ring, there is generally one spline portion, and the transmission load per unit area is large. Therefore, if the rotational backlash amount (L4) is set small here, a large dimensional change is likely to occur and The reduction effect is easily impaired.

  Therefore, the present invention reduces the residual torque in the cam mechanism when the torque is reversed to reduce noise (buzzing noise), and maintains this reduction effect. It aims at providing the power transmission device which can reduce processing and management cost.

The power transmission device according to claim 1 includes an outer rotating member, an inner rotating member disposed coaxially with the outer rotating member, and an outer clutch that engages with the outer rotating member in the rotational direction and is relatively movable in the axial direction. A friction clutch that engages with the inner rotating member in the rotational direction and is movable relative to the axial direction, and that can be intermittently connected between the two rotating members. And a pressure ring capable of relatively moving in the axial direction to press the friction clutch, a cam mechanism for applying a thrust force to the pressure ring, and a pilot clutch mechanism for operating the cam mechanism to generate a thrust force, A power transmission device comprising:
The rotation backlash amount of the engagement portion between the inner rotation member and the pressure ring is L1, the rotation backlash amount of the engagement portion between the inner rotation member and the inner clutch member is L2, and the outer rotation member and the outer side. The values of L1, L2, and L3 are set so that L1 <L3 and L2 <L3 are satisfied when the amount of rotation backlash of the engaging portion with the clutch member is L3. .

The power transmission device according to claim 2 is the power transmission device according to claim 1,
The values of L1, L2, and L3 are set so that L1 <(L2 + L3) / 2 holds.

The power transmission apparatus of claim 3 is a power transmission device according to claim 1 or claim 2, characterized in that the front Symbol L 1 and the previous SL L 2 is equal rather set.

  A power transmission device according to a fourth aspect is the invention according to any one of the first to third aspects, wherein the engaging portion between the outer rotating member and the outer clutch member, the inner rotating member, The engaging portion with the inner clutch member and the engaging portion between the inner rotating member and the pressure ring are each formed by an engaging spline, and the number of teeth of the spline of the outer rotating member is the number of teeth of the inner rotating member. Fewer than spline teeth.

The power transmission apparatus of claim 1, the rotation amount of play between the outer rotary member and the outer clutch member (L3), greater set than the rotational amount of play of the engagement portion between the inner rotating member and the pressure rings (L1), the inner By setting it larger than the amount of rotation backlash (L2) between the rotating member and the inner clutch member, the time point when the backlash between the outer rotating member and the outer clutch member ends is delayed by that amount, and the inner rotating member and the pressure ring Since the start of the reduction of the cam thrust force in the cam mechanism is accelerated by the acceleration of the end of the backlash between the clutches (main clutch) when the backlash between the outer rotating member and the outer clutch member is finished. The torque remaining in the is greatly reduced, and the noise is reduced accordingly.
Also, by setting the large-diameter side rotation play amount L3 to be larger than the small-diameter side rotation play amount, the spline portion between the outer rotation member and the outer clutch member can be easily manufactured with a multiple of the diameter ratio of the small-diameter side spline portion Dimension management is possible.
Further, by setting the rotation backlash amount L3 large in the large-diameter side spline portion having a large engagement area compared to the small-diameter side, the engagement surface pressure between the outer rotating member and the outer clutch member is reduced, and the unit area area is reduced. Since the transmission load is reduced, a change with time of the set rotation backlash amount L3 is suppressed, and the reduction effect of the noise is kept high.

  Also, unlike the conventional example in which the backlash of two places is performed by the small-diameter engaging portion (spline portion), in the case of the power transmission device of the present invention in which backlash is packed by the outer rotating member, the size management of the spline portion is only that. As a result, the manufacturing cost and the management cost are reduced, the transmission load per unit area is reduced, the dimensional change with time is suppressed, and the reduction effect of the noise is kept high.

  In the power transmission device according to claim 2, the amount of rotation play between the inner rotation member and the pressure ring is L1, the amount of rotation play between the inner rotation member and the inner clutch member is L2, and the amount of rotation play between the outer rotation member and the outer clutch member. When L3 is L3, L1 <(L2 + L3) / 2. Thus, by setting the rotation backlash amount L1 between the inner rotating member and the pressure ring to be relatively small, the cam thrust force starts to decrease with a change in the rotation angle of the cam surface, and L1 is set to (L2 + L3) / When the backlash amount of the rotation backlash amount L2 between the inner rotating member and the inner clutch member and the backlash amount L3 between the outer rotating member and the outer clutch member are finished, respectively, the clutch portion (main clutch) Since the residual torque is reduced, the noise is also reduced.

  The invention of claim 3 can obtain the same effect as that of the structure of claim 1 or claim 2.

  In addition, by setting the rotation backlash L1 and L2 of the small-diameter side engaging part (spline part) to the same value, it is possible to share the shape of these spline parts, reducing manufacturing man-hours and dimensional control man-hours, etc. can do.

  According to the invention of claim 4, the same effect as that of the structure of claims 1 to 3 can be obtained.

  Further, since the number of teeth of the spline of the outer rotating member is set to be smaller than the number of teeth of the inner rotating member, it is possible to provide a larger extra portion in the rotating direction in the outer rotating member, and the amount of rotation backlash is desired. It becomes easy to set the value of.

<One Example>
The power transmission device 1 (one embodiment of the present invention) will be described with reference to FIGS. 1 is a cross-sectional view of the power transmission device 1, FIG. 2 is a cross-sectional view taken along line XX and YY of FIG. 1 as viewed from the Z direction, and FIG. The power transmission device 1 is used in a four-wheel drive vehicle based on a rear wheel drive.

[Features of power transmission device 1]
The power transmission device 1 includes a housing 3 (outer rotating member), a hub 5 (inner rotating member) arranged coaxially with the housing 3, an outer engaging with the housing 3 in the rotational direction and relatively movable in the axial direction. It consists of a plate 7 (outer clutch member) and an inner plate 9 (inner clutch member) that engages with the hub 5 in the rotational direction and is relatively movable in the axial direction. A plate-type main clutch 11 (friction clutch), a pressure ring 13 that engages with the hub 5 in the rotational direction, and moves relative to the axial direction to press the main clutch 11, and a ball cam that applies a thrust force to the pressure ring 13 15 (cam mechanism) and a multi-plate pilot clutch 17 that operates the ball cam 15 to generate a thrust force,
The rotational backlash amount L3 of the engaging portion between the housing 3 and the outer plate 7 is set larger than the rotational backlash amount L1 of the engaging portion between the hub 5 and the pressure ring 13;
Further, when the rotation backlash amount of the engaging portion between the hub 5 and the inner plate 9 is L2, the values of L1, L2, and L3 are set so that L1 <(L2 + L3) / 2 holds.

  Further, the rotation backlash amount L1 and the rotation backlash amount L2 are set to the same value, and the rotation backlash amount L3 is set to be larger than the rotation backlash amounts L1 and L2.

  Further, the engaging portion between the housing 3 and the outer plate 7, the engaging portion between the hub 5 and the inner plate 9, and the engaging portion between the hub 5 and the pressure ring 13 are each formed by an engaging spline. The number of teeth Z1 of the spline portion 19 of the housing 3 is set to be smaller than the number of teeth Z2 of the spline portion 21 of the hub 5.

  In addition to the housing 3, the hub 5, the main clutch 11, the pressure ring 13, the ball cam 15, and the pilot clutch 17, the power transmission device 1 sucks the armature 23 and the pilot clutch 17 by sucking it. An electromagnet 25 to be fastened and a cam ring 27 are provided, and the cam surface of the ball cam 15 is provided on the pressure ring 13 and the cam ring 27, respectively.

  The housing 3 includes an aluminum alloy cylindrical member 29, a strength member flange 31 and a magnetic rotor 33. The spline portion 19 of the housing 3 is formed on the inner periphery of the cylindrical member 29. The spline portion 19 is engaged and positioned at the front opening of the cylindrical member 29 by the retaining ring 35, and the rotor 33 is welded to the rear opening of the cylindrical member 29. The flange 31 is connected to the rear wheel side, and the hub 5 is connected to the front wheel side.

  The outer plate 7 of the main clutch 11 is engaged with the spline portion 19 of the cylindrical member 29, the inner plate 9 and the pressure ring 13 are engaged with the spline portion 21 of the hub 5, and the outer plate of the pilot clutch 17 is engaged with the spline portion 19. The inner plate is engaged with a spline portion 37 provided on the outer periphery of the cam ring 27.

  The armature 23 is arranged between the pressure ring 13 and the pilot clutch 17, the electromagnet 25 is supported by the rotor 33 by a double-side sealed ball bearing 39, and the meshing reaction force of the ball cam 15 is applied between the rotor 33 and the cam ring 27. A thrust bearing 41 is disposed, and a return spring 43 is disposed between the hub 5 and the pressure ring 13 to urge the pressure ring 13 in the direction in which the main clutch 11 is released.

  When the electromagnet 25 is excited, the armature 23 is attracted, the pilot clutch 17 is pressed and fastened, the ball cam 15 is actuated by receiving the differential torque between the housing 3 and the hub 5, and the pressure ring 13 is generated by the generated cam thrust force. Presses and fastens the main clutch 11 to connect the power transmission device 1 to bring the vehicle into a four-wheel drive state.

  When the excitation of the electromagnet 25 is stopped, the engagement of the pilot clutch 17 is released and the cam thrust force of the ball cam 15 disappears. Is released, and the vehicle enters the rear wheel drive state.

  In addition, oil flows into and out of the power transmission device 1 from the opening 45 of the cylindrical member 29 and the opening 47 of the hub 5, and lubricates and cools the main clutch 11, the pilot clutch 17, the ball cam 15, and the like.

  While the rear wheel drive-based four-wheel drive vehicle on which the power transmission device 1 is mounted is traveling straight with the main clutch 11 engaged, the rear wheel housing 3 rotates ahead of the front wheel hub 5. However, when the vehicle starts turning, the hub 5 starts accelerating due to the difference in turning radius between the rear wheels and the front wheels, and tries to advance ahead by overtaking the housing 3, so that the direction of the torque applied to the ball cam 15 is reversed.

  The power transmission device 1 has the following effects by setting the rotational backlash amounts L1, L2, and L3 in each spline portion as described above.

  Hereinafter, this effect will be described with reference to each time chart of FIG.

  When the hub 5 starts accelerating as the vehicle turns, as shown in the time chart (3), the backlash amount L2 between the spline portion 21 of the hub 5 and the spline portion of the inner plate 9 is reduced from the time point a. At the same time, it ends at time point b. At the same time, as shown in the time chart (5), the play of the rotation play amount L1 occurs between the spline portion 21 of the hub 5 and the spline portion of the pressure ring 13 as the pressure ring 13 rotates. When the filling starts from the time point e and ends at the time point f, and when the backlash filling of the rotation backlash amount L2 ends at the time point b, the spline portion 19 of the housing 3 and the spline portion of the outer plate 7 as shown in the time chart (4). Rotation backlash amount L3 filling starts from time point c and ends at time point d.

  Further, as the pressure ring 13 rotates in the time chart (5), the cam surface formed on the pressure ring 13 rotates as shown in the time chart (6), and the ball cam 15 is in operation. The time point g shifts to the neutral position time point h, and the time point i at which the ball cam 15 starts to operate again passes through the time point j in the operating state. The time chart (7) shows the change over time of the cam thrust force F generated by the ball cam 15, and the cam thrust force F starts to decrease at the time point k corresponding to the time point g (operating state) of the time chart (6). The cam thrust force F becomes zero (0) at a time point l corresponding to a time point h (neutral position) in (6). The time chart (8) shows the change over time of the torque generated in the main clutch 11, and the torque p remains at the time point d when the backlash amount L3 on the outer plate 7 side is finished in the time chart (4). To do.

  In the power transmission device 1, as described above, the rotational backlash amount of each spline portion is set as L1 <L3, L1 <(L2 + L3) / 2, and L1 = L2 <L3, so that the time chart (5) , By setting the rotational play amount L1 on the pressure ring 13 side to be small, reaching the end point f of the backlashing is promoted, and the rotation of the cam surface (pressure ring 13) is promoted in the time chart (6), Accordingly, the time point g at which the cam thrust force F of the ball cam 15 starts decreasing is promoted in the time chart (7). Further, in the time chart (4), the rotation backlash amount L3 is set to be large, so that the arrival at the backlash finishing time point d is delayed. As a result, the time charts (7) and (8) correspond to this time point d. The residual torque p is greatly reduced as compared with the conventional residual torque m, and the noise is also greatly reduced.

  In addition, the oil that has flowed into the power transmission device 1 stays in the spline portion 19 of the housing 3 due to gravity or centrifugal force, and becomes a resistance for backlash of the rotational backlash amount L3 between the housing 3 and the outer plate 7. It can be expected that the arrival at the closing end point d is greatly delayed, the residual torque in the time chart (8) becomes smaller than p, and the noise is further reduced.

  In the present invention, the amount of rotation play is the amount of play in each of the engaging portions in the rotation direction, and the gap dimension is such that one of the two members that rotate relative to each other is in contact with the other in the rotation direction. Or a gap size existing between two members, or calculated by using a rotation backlash angle when one of the relative rotation members is fixed and the other is rotated, and the engagement radius of the engagement portion. It is a gap dimension obtained or a gap dimension obtained based on each spline specification used for the engaging portion. Therefore, the setting and measurement of the rotation play amount are easy.

[Effect of power transmission device 1]
When the rotation backlash amount L3 between the housing 3 and the outer plate 7 is set to be larger than the rotation backlash amount L1 between the hub 5 and the pressure ring 13, the time point d when the backlash of the rotation backlash L3 between the housing 3 and the outer plate 7 ends. Since the delay 5 is delayed and the end point f of the backlash amount L1 is accelerated by the hub 5 and the pressure ring 13, the cam thrust force F of the ball cam 15 starts to decrease more quickly. The torque p remaining in the main clutch 11 is reduced at the time point d when the backlash is finished, and the noise is reduced.

  Further, unlike the conventional example in which the backlash of two places is performed on the side of the small-diameter spline part, in the power transmission device 1 that performs backlashing on the side of the spline part of the large-diameter housing 3 (spline part 19) and the outer plate 7, The dimensional management of each spline part is made easier, the manufacturing cost and the management cost are reduced, the transmission load per unit area is reduced, the dimensional change with time is suppressed, and the effect of reducing the noise is kept high. Be drunk.

  Further, when the rotation backlash amount between the hub 5 and the inner plate 9 is L2, the rotation backlash amount L1 between the hub 5 and the pressure ring 13 is set relatively to L2 and L3 by setting L1 <(L2 + L3) / 2. Since the reduction of the cam thrust force F accompanying the change of the cam surface rotation angle is accelerated, the hub 5 and the inner plate 9 and the housing 3 and the outer plate 7 are reduced by making L1 smaller than (L2 + L3) / 2. When the backlash of the rotational backlash amounts L2 and L3 is finished, the residual torque of the main clutch 11 is reduced and the noise is reduced.

  Further, by setting the rotation backlash amounts L1 and L2 of the small-diameter side engaging portion (spline portion 21) to the same value and sharing the shape between both the spline portions, it is possible to reduce manufacturing man-hours and dimensional control man-hours.

  Further, since the large-diameter side rotation play amount L3 is set to be larger than the small-diameter side rotation play amounts L1 and L2, the large-diameter side engaging portion (spline portion 19 and the like) is changed to the small-diameter side engaging portion (spline portion). 21) and the like, and can be easily manufactured and controlled in size.

  In addition, since the large amount of rotation play L3 is set in the large-diameter spline portion 19 having a larger engagement area than the small-diameter spline portion 21, the engagement surface pressure between the housing 3 and the outer plate 7 is reduced, and the unit per unit area is reduced. Since the transmission load is reduced, a change with time of the set rotation backlash amount L3 is suppressed, and the reduction effect of the noise is kept high.

  In addition, since the number of teeth Z1 of the spline portion 19 of the housing 3 is set to be smaller than the number of teeth Z2 of the spline portion 21 of the hub 5, a larger surplus portion 49 can be provided in the rotation direction in the housing 3, and the amount of rotation backlash Can be easily set to a desired value (L3).

  [Other Embodiments Included within the Scope of the Present Invention]

  The power transmission device of the present invention may be used for a differential limiting mechanism of a differential device.

1 is a cross-sectional view of a power transmission device 1. FIG. It is XX sectional drawing and YY sectional drawing of FIG. 1 seen from the Z direction. 3 is a time chart of the power transmission device 1; It is a time chart of a prior art example.

Explanation of symbols

1 Power transmission device 3 Housing (outside rotating member)
5 Hub (inner rotating member)
7 Outer plate (outer clutch member)
9 Inner plate (inner clutch member)
11 Main clutch (friction clutch)
13 Pressure ring 15 Ball cam (cam mechanism)
17 Pilot clutch L1 Backlash amount L2 between hub 5 and pressure ring 13 Backlash amount L3 between hub 5 and inner plate 9 Backlash amount Z1 between housing 3 and outer plate 7 Z1 Number of teeth of spline portion 19 Z2 Number of teeth of spline portion 21

Claims (4)

An outer rotating member, an inner rotating member arranged coaxially with the outer rotating member, an outer clutch member that engages with the outer rotating member in the rotational direction and is relatively movable in the axial direction, and rotates with the inner rotating member A friction clutch that can be intermittently engaged between the two rotating members, and the inner rotating member that engages in the rotational direction and relatively moves in the axial direction. A pressure ring capable of pressing the friction clutch, a cam mechanism for applying a thrust force to the pressure ring, and a pilot clutch mechanism for generating a thrust force by operating the cam mechanism. ,
The rotation backlash amount of the engagement portion between the inner rotation member and the pressure ring is L1, the rotation backlash amount of the engagement portion between the inner rotation member and the inner clutch member is L2, and the outer rotation member and the outer side. The values of L1, L2, and L3 are set so that L1 <L3 and L2 <L3 are satisfied when the amount of rotation backlash of the engaging portion with the clutch member is L3. Power transmission device. The power transmission device according to claim 1,
A power transmission device in which values of L1, L2, and L3 are set so that L1 <(L2 + L3) / 2 is established. The power transmission device according to claim 1 or 2,
Power transmission device, characterized in that the front Symbol L 1 and the previous SL L 2 is equal rather set. The power transmission device according to any one of claims 1 to 3,
The engaging portion of the outer rotating member and the outer clutch member, the engaging portion of the inner rotating member and the inner clutch member, and the engaging portion of the inner rotating member and the pressure ring are respectively engaged. The power transmission device is formed of splines, and the number of teeth of the splines of the outer rotating member is smaller than the number of teeth of the splines of the inner rotating member.

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