JP4192955B2 - Driving force transmission device - Google Patents

Description

  The present invention relates to a driving force transmission device.

  As one type of driving force transmission device, a main clutch having a plurality of inner clutch plates and a plurality of outer clutch plates positioned alternately with the inner clutch plates between the outer rotating member and the inner rotating member, an electromagnet, and a friction clutch And an electromagnetic pilot clutch mechanism having an armature, a cam mechanism having a first cam member and a second cam member and positioned between the main clutch and the pilot clutch mechanism, and an electromagnetic coil of the pilot clutch mechanism A pilot torque generated by applying an electric current is converted into an axial cam thrust by the cam mechanism, and the main clutch is pressed and engaged by the cam thrust to generate a torque between the rotating members. There is a driving force transmission device of a type that performs transmission (see Patent Document 1).

In this type of driving force transmission device, each inner clutch plate constituting the main clutch is spline-fitted to the outer spline of the inner rotating member, and each outer clutch plate is connected to the inner spline of the outer rotating member. The first cam member constituting the cam mechanism is rotatably positioned on the inner rotating member, and the second cam member is spline fitted to the outer spline of the inner rotating member. The inner clutch plate of the friction clutch constituting the pilot clutch mechanism is splined to the outer spline of the first cam member, and the outer clutch plate of the friction clutch is splined to the inner spline of the outer rotating member. Some are configured to fit.
JP 2000-234635 A

  By the way, in the driving force transmission device, a usage pattern is adopted in which the vehicle is configured as a four-wheel drive vehicle by being mounted on a power transmission system of the vehicle. In this usage pattern, the cam mechanism is in an operating state by a pilot torque. Thus, when torque is transmitted between the rotating members, a reverse state may occur in the differential rotation of the rotating members. When a reverse state occurs in the differential rotation of both rotating members, an abnormal noise, a so-called buzzing sound, is generated from the driving force transmission device and surrounding devices connected thereto.

  For example, in a four-wheel drive vehicle based on a rear wheel drive equipped with the driving force transmission device, the rotation speed of the rear wheel is faster than the rotation speed of the front wheel, particularly at the time of starting. When the state shifts, the rotational speed of the front wheels becomes faster than the rotational speed of the rear wheels due to the turning radius, and a state in which the differential rotation of both rotating members is reversed occurs. When the differential rotation of both rotating members is reversed, the play of the spline fitting portion of each component member that is spline-fitted to each rotating member, the cam rotation angle in the cam mechanism, the friction of each component member, etc. act synergistically. Then, an abnormal noise, so-called buzzing noise, may occur. In addition, when the vehicle is returned from the cornering to the starting state, an inversion state occurs in the differential rotation during cornering.

  In addition, in both the four-wheel drive vehicle based on the rear wheel drive and the four-wheel drive vehicle based on the front wheel drive, a state in which the differential rotation of both rotating members of the driving force transmission device is reversed occurs. In some cases, a transition from forward travel to reverse travel and a transition from reverse travel to forward travel may occur. Even in such a case, the spline fitting portion of each component member that is spline-fitted to each rotary member In other cases, the noise, the cam rotation angle in the cam mechanism, the friction of each component member, and the like act synergistically to generate abnormal noise, so-called “buzzing noise”.

  As a result of earnestly examining the cause of occurrence of the abnormal noise, the present inventors have found that when the differential rotation is reversed while the cam thrust is held during torque transmission by the driving force transmission device, the cam thrust is reduced. In this state, the differential rotation is reversed. At this time, the backlash of the spline fitting portion between the constituent members constituting the driving force transmission device, the cam rotation angle in the cam mechanism, the friction of the constituent members, etc. Obtained synergistic action, generating abnormal noise, so-called buzzing noise.

  The present invention has been made on the basis of such knowledge, and the object thereof is to provide differential rotation of both rotating members by providing technical means based on the knowledge to the driving force transmission device of the type. The object is to effectively prevent the generation of abnormal noise when is reversed.

  The present invention relates to a driving force transmission device. A first driving force transmission device according to the present invention is a driving force transmission device of the type described above, and each inner clutch plate constituting the main clutch is spline-fitted to an outer spline of the inner rotating member. The outer clutch plates are spline-fitted to the inner splines of the outer rotating member, and the first cam member constituting the cam mechanism is rotatably positioned on the inner rotating member, and the second cam member Is engaged with the outer spline of the inner rotating member and is positioned so as to face the inner clutch plate on one end side of each inner clutch plate so as to be able to directly press the inner clutch plate, and constitute the pilot clutch mechanism. The inner clutch plate of the clutch is sprinkled on the outer spline of the first cam member. And the outer clutch plate of the friction clutch is a driving force transmission device that is spline-fitted to the inner spline of the outer rotating member, and the second cam member constituting the cam mechanism and the inner rotation The spline gap L1 between the outer splines of the member is set smaller than the spline gap L2 between the inner clutch plate constituting the main clutch and the outer spline of the inner rotary member.

  The second driving force transmission device according to the present invention is a driving force transmission device of the type described above, wherein each inner clutch plate constituting the main clutch is spline-fitted to an outer spline of the inner rotating member. In addition, each outer clutch plate is spline-fitted to an inner spline of the outer rotating member, and the first cam member constituting the cam mechanism is rotatably positioned on the inner rotating member, and the second The cam member is spline fitted to the outer spline of the inner rotating member, and the inner clutch plate of the friction clutch constituting the pilot clutch mechanism is spline fitted to the outer spline of the first cam member, and the friction clutch The outer clutch plate is splined to the inner spline of the outer rotating member. A driving force transmission device, wherein the cam angle θ1 of the cam mechanism is determined by a rotation angle θ2 caused by a spline gap between the first cam member constituting the cam mechanism and the inner clutch plate constituting the pilot clutch mechanism. It is characterized by a large setting.

  In the first driving force transmission device according to the present invention, the inner clutch plate that constitutes the main clutch uses the spline gap L1 between the second cam member that constitutes the cam mechanism and the outer spline of the inner rotating member. And a means for setting smaller than the spline gap L2 between the outer splines of the inner rotating member exerts a cam thrust remaining control function for controlling the remaining cam thrust. In the second driving force transmission device according to the present invention, the cam angle θ1 of the cam mechanism is set between the first cam member constituting the cam mechanism and the inner clutch plate constituting the pilot clutch mechanism. The means for setting larger than the rotation angle θ2 caused by the spline gap exhibits a cam thrust remaining control function for controlling the remaining cam thrust. Therefore, in each driving force transmission device according to the present invention, when the differential rotation of both rotating members is reversed, the cam thrust remaining control function can reduce or eliminate the remaining amount of cam thrust. Thus, when torque is transmitted by each of these driving force transmission devices, the generation of abnormal noise such as a cracking noise caused by the remaining cam thrust when the differential rotation is reversed while the cam thrust is held is prevented. be able to.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 shows a partial cross section of a driving force transmission device according to an example of the present invention. The driving force transmission device 10 has a substantially symmetrical structure around the axis, and FIG. 1 shows a substantially half cross section around the axis. As shown in FIG. 2, the driving force transmission device 10 is mounted as a component part of a transfer constituting a four-wheel drive vehicle based on a rear wheel drive.

  The four-wheel drive vehicle is a four-wheel drive vehicle based on a rear wheel drive on which a vertical engine 21 is mounted, and includes a transfer 23 on the rear side of a transmission 22 disposed on the rear side of the engine 21. . The transfer 23 is disposed between the rear propeller shaft 24a and the front propeller shaft 24b and intermittently connects the two propeller shafts 24a and 24b. The driving force of the engine 21 is always applied to the rear propeller shaft 24a. When the two propeller shafts 24a and 24b are connected to each other, the driving force of the engine 21 is distributed and output to the front propeller shaft 24b.

  In the four-wheel drive vehicle, when both propeller shafts 24a and 24b are in a disconnected state, the driving force of the engine 21 is output only to the rear propeller shaft 24a, and the driving force is applied to the rear differential 25a. And output to both axle shafts 26a, 26a to drive the left and right rear wheels 26b, 26b. Thus, the four-wheel drive vehicle constitutes a two-wheel drive state in which the rear wheels 26b and 26b are driven. Further, in the four-wheel drive vehicle, when both propeller shafts 24a and 24b are in the connected state, the driving force of the engine 21 is distributed to the rear propeller shaft 24a and the front propeller shaft 24b and to the front propeller shaft 24b. The output driving force is output to both axle shafts 27a and 27a via the front differential 25b to drive the left and right front wheels 27b and 27b. Thus, the four-wheel drive vehicle constitutes a four-wheel drive state.

  The driving force transmission device 10 constitutes a transfer integrally with a coupling mechanism (not shown), and as shown in FIG. 1, the outer case 10a, the inner shaft 10b, the main clutch 10c, the pilot clutch mechanism 10d, and the cam mechanism 10e. It has.

  The outer case 10a constituting the driving force transmission device 10 constitutes the outer rotating member in the present invention. The outer case 10a is fitted and screwed into the cylindrical housing 11a and the rear end opening of the housing 11a so that the opening is formed. The rear cover 11b covers the cover. The housing 11a is made of an aluminum alloy that is a nonmagnetic material, and the rear cover 11b is made of iron that is a magnetic material. A stainless steel cylinder 11c, which is a nonmagnetic material, is embedded in the middle portion of the rear cover 11b, and the cylinder 11c forms an annular nonmagnetic portion. The inner shaft 10b penetrates the central portion of the rear cover 11b in a liquid-tight manner and is coaxially inserted into the outer case 10a. The inner shaft 10b is connected to the front side wall portion of the housing 11a and the rear cover 11b in a state where the axial direction is restricted. It is rotatably supported.

  The inner shaft 10b constitutes an inner rotating member in the present invention, and is spline-fitted to the rear propeller shaft 24a penetrating the inner hole, and is connected to the rear propeller shaft 24a so as to transmit torque. A drive sprocket (not shown) is attached to the front side wall of the housing 11a so as to be integrally rotatable, and a driven sprocket (not shown) is attached to the outer periphery of the front propeller shaft 24b so as to be integrally rotatable. A drive chain (not shown) is suspended between these two sprockets to form a transfer coupling mechanism. The coupling mechanism functions to transmit the driving force of the outer case 10a to the front propeller shaft 24b.

  The main clutch 10c is a wet multi-plate friction clutch, and includes a large number of clutch plates (an inner clutch plate 12a and an outer clutch plate 12b), and is disposed in the housing 11a. Each inner clutch plate 12a constituting the main clutch 10c is assembled to the outer spline 11d of the inner shaft 10b by spline fitting so as to be movable in the axial direction, and each outer clutch plate 12b is connected to the inner spline 11e of the housing 11a. It is assembled so that it can be moved in the axial direction by spline fitting. The inner clutch plates 12a and the outer clutch plates 12b are alternately positioned, abut against each other and frictionally engage with each other, and are separated from each other to be in a free state.

  The pilot clutch mechanism 10 d includes an electromagnet 13, a friction clutch 14, an armature 15, and a yoke 16. The electromagnet 13 has an annular shape, and is fitted in the annular recess of the rear cover 11b while being fitted to the yoke 16. The yoke 16 is fixed to the vehicle body side while being rotatably supported on the outer periphery of the rear end portion of the rear cover 11b.

  The friction clutch 14 is a wet friction clutch including a plurality of outer clutch plates 14a and an inner clutch plate 14b. Each outer clutch plate 14a is spline-fitted to the inner spline 11e of the housing 11a and can move in the axial direction. In addition, each inner clutch plate 14b is assembled so as to be movable in the axial direction by spline fitting with an outer spline 17a1 of a first cam member 17a constituting a cam mechanism 10e described later. The armature 15 has an annular shape, and is assembled to the inner spline 11e of the housing 11a so as to be spline-fitted and movable in the axial direction. The armature 15 is located on the front side of the friction clutch 14 and faces it.

  In the pilot clutch mechanism 10d configured as described above, a loop-shaped circulation through which the magnetic flux circulating through the yoke 16, the rear cover 11b, the friction clutch 14, and the armature 15 starts from the electromagnet 13 by energizing the electromagnetic coil of the electromagnet 13. A magnetic path is formed. The current applied to the electromagnetic coil of the electromagnet 13 is controlled to a predetermined current value set by duty control.

  The energization of the electromagnetic coil of the electromagnet 13 is intermittently performed by a manual switch switching operation, and three drive modes described later can be selected. The switch is arranged in the vicinity of the driver's seat in the passenger compartment so that the driver can easily operate it. Note that if the driving force transmission device 10 is configured only in the second driving mode described later, the switch can be omitted.

  The cam mechanism 10e includes a first cam member 17a, a second cam member 17b, and a cam follower 17c. The first cam member 17a is rotatably fitted to the outer periphery of the inner shaft 10b, and is rotatably supported by the rear cover 11b. The inner clutch plate 14b of the friction clutch 14 is spline-fitted to the outer spline 17a1. is doing. The second cam member 17b is spline-fitted to the outer spline 11d of the inner shaft 10b and assembled so as to be integrally rotatable, and is positioned opposite to the rear side of the inner clutch plate 12a of the main clutch 10c. A ball-shaped cam follower 17c is interposed in the cam grooves of the first cam member 17a and the second cam member 17b facing each other.

  In the driving force transmission device 10, when the electromagnetic coil of the electromagnet 13 constituting the pilot clutch mechanism 10d is in a non-energized state, no magnetic path is formed and the friction clutch 14 is in a non-engaged state. For this reason, the pilot clutch mechanism 10d is in an inoperative state, the first cam member 17a constituting the cam mechanism 10e can rotate integrally with the second cam member 17b via the cam follower 17c, and the main clutch 10c is not operated. In operation. Therefore, the outer case 10a and the inner shaft 10b are in a disconnected state, and the vehicle constitutes a first drive mode that is a two-wheel drive in which the rear wheels 26b and 26b are driven.

  On the other hand, in the driving force transmission device 10, when the electromagnetic coil of the electromagnet 13 of the pilot clutch mechanism 10d is energized, a loop-shaped circulation magnetic path with the electromagnet 13 as a starting point is formed, and magnetic force is generated. The armature 15 is sucked. As a result, the armature 15 presses the friction clutch 14 to frictionally engage it, and connects the first cam member 17a of the cam mechanism 10e to the outer case 10a side, thereby causing relative rotation with the second cam member 17b. Let As a result, in the cam mechanism 10e, the cam follower 17c presses both the cam members 17a and 17b away from each other.

  For this reason, the second cam member 17b is pushed toward the main clutch 10c and presses the main clutch 10c with the front side wall portion of the housing 11a to be frictionally engaged according to the friction engagement force of the friction clutch 14. As a result, torque is transmitted between the outer case 10a and the inner shaft 10b, and the vehicle constitutes a second drive mode in which the propeller shafts 24a and 24b are four-wheel drive between the non-directly connected state and the directly connected state. In this drive mode, the driving force distribution ratio between the rear front wheels can be controlled in a range from 100: 0 (two-wheel drive state) to a direct connection state according to the traveling state of the vehicle.

  In this second drive mode, the current applied to the electromagnetic coil is duty-controlled based on signals from various sensors such as a wheel speed sensor, an accelerator opening sensor, and a rudder angle sensor in accordance with the traveling state and road surface state of the vehicle. Thus, the cam thrust due to the frictional engagement force of the friction clutch 14 is controlled, and the transmission torque to the front wheels 27b and 27b is controlled.

  Further, when the current applied to the electromagnetic coil of the electromagnet 13 is increased to a predetermined value, the attractive force of the electromagnet 13 with respect to the armature 15 is increased, and the armature 15 is strongly attracted to increase the frictional engagement force of the friction clutch 14, and both cams The relative rotation between the members 17a and 17b is increased. As a result, the cam follower 17c increases the pressing force (cam thrust) against the second cam member 17b, and brings the main clutch mechanism 10c into a coupled state. For this reason, the vehicle constitutes a third drive mode that is a four-wheel drive in which both propeller shafts 24a and 24b are directly connected.

  As shown in FIG. 2, the driving force transmission device 10 is mounted as a component part of a transfer constituting a four-wheel drive vehicle based on rear wheel driving. The driving force transmission device 10A is changed to a configuration that can be disposed in the middle of the driving force transmission path on the rear wheel side of the four-wheel drive vehicle based on the front wheel drive, as shown in FIG. By disposing in the middle of the driving force transmission path to the rear wheel side, a four-wheel drive vehicle based on the front wheel drive can be configured.

  In the driving force transmission device 10A, the outer case 10a constituting the driving force transmission device 10 shown in FIG. 1 is changed to a configuration in which torque transmission can be performed to a first propeller shaft 24c described later, and the inner shaft 10b is described later. The second propeller shaft 24d is inserted and connected to be able to transmit torque. The driving force transmission device 10A is connected to the outer case 10a by connecting the first propeller shaft 24c so that torque can be transmitted, and by connecting the second propeller shaft 24d to the inner shaft 10b so that torque can be transmitted, to the rear wheel side. The four-wheel drive vehicle based on the front wheel drive is arranged in the middle of the drive force transmission path.

  In the four-wheel drive vehicle, the transaxle 28 is integrally provided with a transmission, a transfer, and a front differential, and the driving force of the engine 21 is output to both axle shafts 27a and 27a via the front differential 25b of the transaxle 28. The left and right front wheels 27b and 27b are driven and output to the first propeller shaft 24c side. The first propeller shaft 24c is connected to the second propeller shaft 24d via the driving force transmission device 10A, and when both the propeller shafts 24c and 24d are connected so as to be able to transmit torque, the driving force is rear differential. 25a and output from the rear differential 25a to both axle shafts 26a, 26a to drive the left and right rear wheels 26b, 26b.

Accordingly, the driving force transmission devices 10 and 10A are provided with cam thrust remaining restricting means which is means for preventing abnormal noise. FIG. 4 shows the first remaining thrust control means, and FIG. 5 shows the second remaining thrust control means. As shown in FIG. 4, the first thrust remaining regulating means includes a spline gap L1 between the second cam member 17b constituting the cam mechanism 10e and the inner shaft 10b, an inner clutch plate 12a constituting the main clutch 10c, and the inner shaft. This is a mechanical means for setting the spline clearance L2 smaller than 10b. Further, as shown in FIG. 5 (a), the second thrust remaining restricting means is configured such that the cam angle θ1 of the cam mechanism 10e is set to the first cam member 17a constituting the cam mechanism 10e and the inner constituting the pilot clutch mechanism 10d. It is cam thrust residual control means that is set larger than the rotation angle caused by the spline clearance of the clutch plate 14b. In general, the cam angle of the cam mechanism and the rotation angle caused by the spline gap are set to the same angle, and the cam angle in the normal cam mechanism is set to the cam angle θ2 as shown in FIG. 5B , for example . Has been. In other words, the second cam thrust remaining regulating means, the cam angle θ1 of the cam mechanism 10e is set larger than the cam angle θ2 of the conventional cam Organization.

  6 to 8 show the operation of each component when the differential rotation between the outer case 10a and the inner shaft 10b is reversed in the driving force transmission device 10 constituting the four-wheel drive vehicle based on the rear wheel drive. It is an example of the time chart which shows a state with time. The time chart of FIG. 6 shows a case where the cam thrust remaining control means is not provided. The time chart of FIG. 7 shows a case where the first cam thrust remaining control means is provided. The time chart of FIG. 8 shows a case where the second cam thrust remaining control means is provided. In the driving force transmission device 10, the inner shaft 10b is on the input side and the outer case 10a is on the output side.

  In FIG. 6 which shows a time chart when the cam thrust remaining control means is not provided, ten kinds of time charts (1) to (10) are shown. Among these time charts, time chart (1) shows a change with time in the rotation direction of the inner shaft 10b during reversal. In this time chart (1), when the inner shaft 10b rotates in the + θ to −θ direction, the rotation in the reverse direction (reverse) is performed, and when the inner shaft 10b rotates in the direction opposite to the rotation direction, the rotation in the forward direction (forward) ).

  The time chart (2) shows a change with time of the attractive force with respect to the armature 15 in the pilot clutch mechanism 10d. This time chart (2) is set to a lock mode (the above-described third drive mode) in which the outer case 10a and the inner shaft 10b are coupled with the suction force F to the armature 15 being constant.

  The time chart (3) shows the change over time of the rotation angle of the spline gap between the inner shaft 10b and the inner clutch plate 12a of the main clutch 10c. In the time chart (3), at the time point (a) at which the transition from + θ to −θ starts, the inner shaft 10b is reversed (reversed), and the spline of the inner clutch plate 12a of the main clutch 10c is turned to the opposite side. The time point (b) at which −θ is reached is the time point when the spline of the inner clutch plate 12a is completely jammed to the opposite side.

  The time chart (4) shows the change over time of the rotation angle of the spline gap between the outer clutch plate 12b of the main clutch 10c and the housing 11a of the outer case 10a. In this time chart (4), the time point (c) at which the transition from + θ to −θ starts is the time point when the spline gap between the outer clutch plate 12b and the housing 11a starts, and the spline of the inner clutch plate 12a is opposite. It coincides with the time point (b) when it is completely clogged to the side. The time point (d) at which −θ is reached is the time point when the spline of the outer clutch plate 12b is completely jammed to the opposite side.

  The time chart (5) shows the change over time of the rotation angle of the spline gap between the inner shaft 10b and the second cam member 17b of the cam mechanism 10e. In the time chart (5), the time point (e) at which the transition from + θ to −θ starts is the time point at which the spline gap between the inner shaft 10b and the second cam member 17b starts, and the time point at which −θ is reached ( f) is a point in time when the spline gap between the inner shaft 10b and the second cam member 17b is completely jammed. In the conventional driving force transmission device, these time points (e) and (f) are set to coincide with the time points (a) and (b) in the time chart (3).

  The time chart (6) shows the change over time of the cam rotation angle in the cam mechanism 10e. In this time chart (6), the time point (g) at which the transition from + θ to −θ is started is the time point when the cam mechanism 10e starts to shift from the operating state to the neutral state, and the time point (h) is the neutral state. The time point (i) is the time point when the transition from the neutral state to the operating state is started, and the time point (j) is the time point when the operation state is completely restored. In the time chart (6), the time point (g) at which the cam mechanism 10e starts to shift from the operating state to the neutral state is the time point (b) at which the spline of the inner clutch plate 12a is completely jammed to the opposite side (b). The timing coincides with the time point (c) when the spline gap between the clutch plate 12b and the housing 11a begins to clog, and the time point (f) when the spline gap between the inner shaft 10b and the second cam member 17b is completely jammed.

  The time chart (7) shows the change over time of the rotation angle of the spline gap between the first cam member 17a and the inner clutch plate 14b of the friction clutch 14 in the pilot clutch mechanism 10d. In this time chart (7), the time point (k) at which the transition from + θ to −θ starts is the time point when the spline gap between the first cam member 17a and the inner clutch plate 14b starts to clog on the opposite side, and the time point ( 1) is a point in time when the spline gap between the first cam member 17a and the inner clutch plate 14b is completely clogged. The time point (k) at which the spline gap between the first cam member 17a and the inner clutch plate 14b starts to clog on the opposite side coincides with the time point (h) when the cam mechanism 10e reaches the neutral state.

  The time chart (8) shows the change over time of the rotational angle of the spline gap between the outer clutch plate 14a of the friction clutch 14 and the housing 11a of the outer case 10a in the pilot clutch mechanism 10d. In this time chart (8), the time point (m) at which the transition from + θ to −θ starts is the time point when the spline gap between the outer clutch plate 14a and the housing 11a begins to clog, and the time point (n) when it reaches −θ. Is a point in time when the spline gap between the outer clutch plate 14a and the housing 11a is completely jammed to the opposite side. The time point (m) at which the spline gap between the outer clutch plate 14a and the housing 11a begins to clog coincide with the time point (l) at which the spline gap between the first cam member 17a and the inner clutch plate 14b is completely jammed. .

  The time chart (9) shows the change over time of the cam thrust. The cam thrust F is proportional to the absolute value of the cam rotation angle. The time point (o) at which the cam thrust force F starts to decrease and the time point (p) at which the cam thrust force F becomes zero are shown in the time chart (6). The timing coincides with the time point (g) when the cam mechanism 10e starts transition from the operating state to the neutral state and the time point (h) when the cam mechanism 10e reaches the neutral state. The cam thrust F remains between the time point when the cam thrust F starts decreasing (o) and the time point when the cam thrust F becomes zero (p).

  The time point (q) and the time point (r) in the time chart (9) are time points corresponding to the time point (o) when the cam thrust force F starts to drop and the time point (p) when the cam thrust force F becomes zero. 10b shows the remaining range of the cam thrust F accompanying the reversal that occurs when the vehicle 10b switches from reverse to forward.

  The time chart (10) shows the change over time of the torque in the main clutch 10c. This time chart (10) shows that torque is generated from time (s) to time (t). The torque is generated due to the remaining amount f of the cam thrust that exists after the time point (d) when the spline gap of the inner clutch plate 12a of the main clutch 10c and the inner shaft 10b of the main clutch 10c are completely filled in the time chart (4). . The generation of torque from time (u) to time (v) is the same. These torques are the cause of abnormal noise.

  Therefore, the remaining cam thrust amount f between the time point (o) and the time point (p) shown in the time chart (9) and the remaining cam thrust amount between the time point (q) and the time point (r) are expressed as follows. If a means for reducing or eliminating (cam thrust remaining control means) is adopted, the generated torque shown in the time chart (10) can be reduced or eliminated.

  The above relationship of the time chart is similarly established in the driving force transmission device 10A constituting the four-wheel drive vehicle based on the front wheel drive. By adopting the cam thrust remaining restricting means, the time chart (10 ) Generated torque can be reduced or eliminated. As the cam thrust remaining regulating means, the first cam thrust remaining regulating means shown in FIG. 4 can be adopted, and the second cam thrust remaining regulating means shown in FIG. 5 can be adopted.

  The first cam thrust remaining restricting means shown in FIG. 4 includes a spline gap L1 between the second cam member 17b constituting the cam mechanism 10e and the inner shaft 10b, an inner clutch plate 12a constituting the main clutch 10c, and an inner shaft 10b. This is cam residual thrust regulating means that is set smaller than the spline clearance L2. By adopting the first cam thrust remaining control means, the change over time of the operation of each component constituting the driving force transmission devices 10 and 10A is shown in FIG. 7 from the state of the time chart shown in FIG. Changed to the state of the time chart.

  That is, since the spline clearance L1 between the second cam member 17b and the inner shaft 10b is set smaller than the spline clearance L2 between the inner clutch plate 12a and the inner shaft 10b constituting the main clutch 10c, the time chart (3) shows. The point (b) at which the spline of the inner clutch plate 12a abuts and the point (f) at which the second cam member 17b abuts as shown in the time chart (5) are the same timing. The point in time (f ′) is earlier. As a result, the timing (g ′) at which the cam mechanism 10e starts to return to the neutral state shown in the time chart (6) is earlier, in other words, the cam rotation is started earlier and the cam mechanism 10e is brought into the neutral state. The remaining speed f1 of the cam thrust at the time point (d) when the outer clutch plate 12b abuts as shown in the time chart (4) is smaller than the remaining cam thrust f shown in FIG. . Note that the time point (g ′) to the time point (r ′) are also at an early timing because the time point (f ′) is at an early timing.

  As a result, according to the first cam thrust remaining control means, when the differential rotation between the outer case 10a and the inner shaft 10b is reversed in the driving force transmission devices 10 and 10A, the remaining amount of cam thrust is reduced. It is possible to control the torque t1 generated in the main clutch 10c while the cam thrust remains, and to prevent the occurrence of a cracking sound.

Further, as shown in FIG. 5A, the second cam thrust remaining restricting means configures the cam angle θ1 of the cam mechanism 10e, the first cam member 17a constituting the cam mechanism 10e, and the pilot clutch mechanism 10d. This is cam remaining thrust regulating means that is set to be larger than the rotation angle θ2 caused by the spline clearance of the inner clutch plate 14b. In general, the cam angle of the cam mechanism and the rotation angle caused by the spline gap are set to the same angle, and the cam angle in the normal cam mechanism is set to the cam angle θ2 as shown in FIG. 5B , for example . Has been. In other words, the second cam thrust remaining regulating means, the cam angle θ1 of the cam mechanism 10e is set larger than the cam angle θ2 of the conventional cam Organization. By adopting the second cam thrust remaining control means, the time-dependent change in the operation of each constituent member constituting the driving force transmission devices 10 and 10A is shown in FIG. 8 from the state of the time chart shown in FIG. Changed to the state of the time chart.

  That is, the time point (h ″) at which the cam mechanism 10e reaches the neutral state shown in the time chart (6) of FIG. 8 is earlier than the simultaneous point (h) shown in the time chart (6) of FIG. In other words, the return to the neutral state of the cam is accelerated, and the remaining amount f2 of the cam thrust at the time point (d) when the outer clutch plate 12b contacts as shown in the time chart (4) is the cam shown in FIG. This is smaller than the remaining amount of thrust f. Due to the earlier timing of time (h ″), time (i ″) to time (p ″) and time (r ″) are the same. It will be early.

  As a result, according to the second cam thrust remaining control means, when the differential rotation between the outer case 10a and the inner shaft 10b is reversed in the driving force transmission devices 10 and 10A, it is a cause of the generation of the noise. The cam thrust remaining amount f2 can be controlled to be small, and the torque t2 generated in the main clutch 10c while the cam thrust remains is smaller than the torque t shown in the time chart (10) of the time chart of FIG. In other words, it is possible to prevent the occurrence of a crackle sound.

It is a fragmentary sectional view of the driving force transmission device concerning an example of the present invention. It is a skeleton figure of the four-wheel drive vehicle based on the rear-wheel drive which mounted the drive force transmission device incorporated in the transfer. It is a skeleton figure of the four-wheel drive vehicle based on the front wheel drive which changed and mounted the drive force transmission device. It is explanatory drawing which shows schematically the structure of a 1st cam thrust remaining control means. It is explanatory drawing which shows schematically the structure of a 2nd cam thrust remaining control means. It is a time chart which shows a time-dependent change of operation | movement of each structural member of the conventional driving force transmission apparatus. It is a time chart which shows the time-dependent change of operation | movement of each structural member of the driving force transmission apparatus which provided the 1st cam thrust remaining control means. It is a time chart which shows a time-dependent change of operation | movement of each structural member of the driving force transmission apparatus which provided the 2nd cam thrust remaining control means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10A ... Driving force transmission apparatus, 10a ... Outer case, 10b ... Inner shaft, 10c ... Main clutch, 10d ... Pilot clutch mechanism, 10e ... Cam mechanism, 11a ... Housing, 11b ... Rear cover, 11c ... Cylindrical body, 11d ... Outer spline, 11e ... Inner spline, 12a ... Inner clutch plate, 12b ... Outer clutch plate, 13 ... Electromagnet, 13a ... Electromagnetic coil, 14 ... Friction clutch, 14a ... Outer clutch plate, 14b ... Inner clutch plate, 15 ... Armature, 16 ... Yoke, 17a ... First cam member, 17b ... Second cam member, 17c ... Cam follower, 21 ... Engine, 22 ... Transmission, 23 ... Transfer, 24a ... Rear propeller shaft, 24b ... Front propeller shaft, 24c ... First 1 pro Lashaft, 24d ... second propeller shaft, 25a ... rear differential, 25b ... front differential, 26a ... rear axle shaft, 26b ... rear wheel, 27a ... front axle shaft, 27b ... front wheel, 28 ... transaxle, L1, L2 … Spline clearance, θ1, θ2… Cam angle. f, f1, f2 ... remaining cam thrust, t, t1, t2 ... generated torque.

Claims (2)

A main clutch having a plurality of inner clutch plates and a plurality of outer clutch plates positioned alternately between the outer rotating member and the inner rotating member, and an electromagnetic pilot clutch having an electromagnet, a friction clutch, and an armature And a pilot torque generated by applying a current to an electromagnetic coil of the pilot clutch mechanism, comprising a mechanism, a cam mechanism having a first cam member and a second cam member and positioned between the main clutch and the pilot clutch mechanism. Is converted into an axial cam thrust by the cam mechanism, and the main clutch is pressed and engaged by the cam thrust to transmit torque between the rotating members. Each inner clutch plate constituting the main clutch is in front The outer clutch plate is spline fitted to the outer spline of the inner rotating member, and each outer clutch plate is spline fitted to the inner spline of the outer rotating member, and the first cam member constituting the cam mechanism is placed on the inner rotating member. The second cam member is spline-fitted to the outer spline of the inner rotating member and faces the inner clutch plate on one end side of each inner clutch plate so as to be able to directly press the inner clutch plate. And the inner clutch plate of the friction clutch constituting the pilot clutch mechanism is splined to the outer spline of the first cam member, and the outer clutch plate of the friction clutch is splined to the inner spline of the outer rotating member. With the mating driving force transmission device It, between the outer splines of the spline clearance between the outer splines of the second cam member and the inner rotational member (L1), said inner clutch plate and the inner rotational member constituting the main clutch constituting the cam mechanism The driving force transmission device is characterized by being set smaller than the spline clearance (L2) . A main clutch having a plurality of inner clutch plates and a plurality of outer clutch plates positioned alternately between the outer rotating member and the inner rotating member, and an electromagnetic pilot clutch having an electromagnet, a friction clutch, and an armature And a pilot torque generated by applying a current to an electromagnetic coil of the pilot clutch mechanism, comprising a mechanism and a cam mechanism having a first cam member and a second cam member and positioned between the main clutch and the pilot clutch mechanism. Is converted into an axial cam thrust by the cam mechanism, and the main clutch is pressed and engaged by the cam thrust to transmit torque between the rotating members. Each inner clutch plate constituting the main clutch is in front The outer clutch plate is spline fitted to the outer spline of the inner rotating member, and each outer clutch plate is spline fitted to the inner spline of the outer rotating member, and the first cam member constituting the cam mechanism is placed on the inner rotating member. The second cam member is spline-fitted to the outer spline of the inner rotating member, and the inner clutch plate of the friction clutch constituting the pilot clutch mechanism is attached to the outer spline of the first cam member. A driving force transmission device in which the outer clutch plate of the friction clutch is spline-fitted to the inner spline of the outer rotating member, and the cam angle (θ1) of the cam mechanism is set to the cam mechanism. The first cam member constituting the pilot clutch mechanism and the inboard constituting the pilot clutch mechanism Driving force transmission device, characterized in that is set larger than the rotation angle (.theta.2) due to the spline clearance between the clutch plates.