JP2009019659A - Driving force transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a shock caused by residual torsion of a driving system due to rotation speed difference between a front wheel (left wheel) and a rear wheel (right wheel) while a vehicle is travelling. <P>SOLUTION: A torsional angle of the driving system is detected and, when an angle on reversing a torsional direction becomes close to zero, a control is conducted so that an applied current on an electromagnetic coil 13a is reduced, the residual torque remaining in a main clutch mechanism 10c is released and then a current is applied on the electromagnetic coil 13a and the main clutch mechanism 10c is reengaged. Thus, as torque is reduced in the main clutch mechanism 10c while torsion of the driving system is almost eliminated, shock generation due to torque release is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a driving force transmission device arranged in a power transmission path of front and rear wheels of a vehicle to constitute a front and rear wheel drive vehicle, and a driving force transmission arranged in a power transmission path of left and right wheels of the vehicle to constitute a limited slip differential. Relates to the device.

  As a type of driving force transmission device for a vehicle, a main clutch mechanism, a cam mechanism, and an electromagnetic pilot are provided between an outer rotating member and an inner rotating member positioned coaxially and rotatably in the outer rotating member. A clutch mechanism is provided, and a pilot torque generated by applying an electric current to an electromagnetic coil of the pilot clutch mechanism is converted into an axial cam thrust by the cam mechanism, and the main thrust is converted by the cam thrust. A driving force transmission device that performs torque transmission between the rotating members by pressing and engaging the clutch mechanism, and coupling transmission generated in the main clutch mechanism by increasing or decreasing an applied current to the electromagnetic coil There is a driving force transmission device of a type provided with a control device for controlling torque (see Patent Document 1).

  By the way, in the usage form in which the driving force transmission device of this type is arranged in the power transmission path of the front and rear wheels of the vehicle and the vehicle is configured as a four-wheel drive vehicle, the cam mechanism is in an operating state by a pilot torque and both rotating members When torque is transmitted between the rotating members, a reverse state (torque reversal) may occur in the differential rotation of both rotating members. When reversing the transmission torque that causes a reverse state in the differential rotation of both rotating members, fluctuations in the transmission torque (torque fluctuations) occur due to stickiness, friction, etc. of each component member constituting the drive system In addition, the torque fluctuation may cause abnormal noise.

  For example, in a four-wheel drive vehicle based on a rear wheel drive equipped with a driving force transmission device of this type, 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 traveling state is shifted, 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, fluctuations in transmission torque (torque fluctuations) occur due to stickiness lip caused by backlash, friction, and the like of the constituent members constituting the drive system. 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, the vehicle travels from forward travel to reverse travel, and the vehicle travels from reverse travel to forward travel.

Further, in the usage mode in which the driving force transmission device of this type is arranged in the power transmission path of the left and right wheels of the vehicle to constitute a limited slip differential, there is a difference in rotational speed between the left and right wheels when the vehicle is turning. Differential rotation occurs in both rotating members, but when the turning direction of the vehicle is reversed, a state in which the differential rotation of both rotating members of the driving force transmission device is reversed (torque reversal) occurs. At the time of reversal of the transmission torque in which a reverse state occurs in the differential rotation of the motor, fluctuations in the transmission torque (torque fluctuation) may occur due to stickiness lip caused by play or friction of each component member constituting the drive system, Moreover, the torque fluctuation may cause abnormal noise.
Japanese Patent No. 3848835

  As described above, in the driving force transmission device of this type, when the transmission torque is reversed, the transmission torque fluctuates (torque fluctuation) due to stickiness or friction caused by play or friction of each component constituting the driving system. In addition, the torque fluctuation may cause abnormal noise. In order to cope with such a problem, the driving force transmission device proposed in Patent Document 1 described above employs means for reducing the torque in the main clutch mechanism when the direction of the transmission torque is reversed. Yes. However, when such a torque reducing means is employed, the torque is reduced while the twist remains in the drive system, so that a shock due to torque loss may occur. Accordingly, an object of the present invention is to prevent the occurrence of shock due to such torque loss.

  The present invention relates to a driving force transmission device. The driving force transmission device to which the present invention is applied includes a main clutch mechanism, a cam mechanism, and an electromagnetic type motor between an outer rotating member and an inner rotating member that is coaxially and rotatably positioned in the outer rotating member. A pilot clutch mechanism is provided, and a pilot torque generated by applying a current to an electromagnetic coil of the pilot clutch mechanism is converted into an axial cam thrust by the cam mechanism, and the cam thrust A driving force transmission device that presses and engages a main clutch mechanism to transmit torque between the rotating members, and the coupling generated in the main clutch mechanism by increasing or decreasing an applied current to the electromagnetic coil It is a drive force transmission device of a type provided with a control device for controlling transmission torque.

  Thus, a first driving force transmission device according to the present invention is a driving force transmission device of the type described above, and a driving path connected to the outer rotating member or the outer rotating member and the inner rotating member or the same. A torsion angle detecting means for detecting a torsion angle between the drive path connected to the inner rotating member and the control device when the torsion direction of the torsion angle detected by the torsion angle detecting means is reversed; When the twist angle reaches near zero, the applied current to the electromagnetic coil is reduced, the cam thrust remaining in the cam mechanism is released, and then the current is applied to the electromagnetic coil to apply the main clutch mechanism. The control for re-engaging is performed.

  The second driving force transmission device according to the present invention is a driving force transmission device of the above-described type, wherein the driving path is connected to the outer rotating member or the outer rotating member and the inner rotating member or the same inner member. A torsion angle detecting means for detecting a torsion angle between the drive path and the drive path connected to the rotating member, wherein the control device is a torsion when the torsion direction of the torsion angle detected by the torsion angle detecting means is reversed; When the angle exceeds zero and reaches a predetermined angle in the reverse direction, the applied current to the electromagnetic coil is reduced, the cam thrust remaining in the cam mechanism is released, and then the current is applied to the electromagnetic coil. Then, control for re-engaging the main clutch mechanism is performed.

  In these driving force transmission devices according to the present invention, the front and rear wheel drive vehicles based on the rear wheel drive are configured by disposing the engine driving force to the front wheel side and the rear wheel side. It is possible to adopt a configuration in which a front and rear wheel drive vehicle based on a front wheel drive is configured by being disposed in a drive path that transmits the driving force of the engine to the rear wheel side. It is possible to adopt a usage form in which a limited slip differential is configured by being disposed on a drive path that transmits the drive force to the left wheel side and the right wheel side.

  In the first driving force transmission device according to the present invention, the torsion angle between the outer rotating member or the driving path connected to the outer rotating member and the driving path connected to the inner rotating member or the inner rotating member is detected. When the angle when the twist direction is reversed reaches near zero, the applied current to the electromagnetic coil is reduced to release the cam thrust remaining in the cam mechanism, and then the current is applied to the electromagnetic coil. Since the main clutch mechanism is controlled to be re-engaged, the torque in the main clutch mechanism is reduced in a state where the twist of the drive system is almost eliminated, so that the occurrence of shock due to torque loss is prevented. Can do.

  Further, in the second driving force transmission device according to the present invention, the twist angle between the outer rotating member or the driving path connected to the outer rotating member and the driving path connected to the inner rotating member or the inner rotating member is set. When the angle at which the twist direction reverses exceeds zero and reaches a predetermined angle in the reverse direction, the applied current to the electromagnetic coil is reduced, and the cam thrust remaining in the cam mechanism is released. After that, since control is performed to re-engage the main clutch by applying current to the electromagnetic coil, as in the first driving force transmission device described above, the main clutch mechanism is in a state in which the twist of the driving system is substantially eliminated. Therefore, the occurrence of shock due to torque loss can be prevented.

  Particularly when the control means for controlling the applied current of the electromagnetic coil is employed as in the second driving force transmission device according to the present invention, the vehicle is once changed to a traveling state in which the twist direction of the drive system is reversed. In the case of adopting a traveling state in which the vehicle is quickly returned to the original traveling state, there is an advantage that unnecessary control of the current applied to the electromagnetic coil can be avoided.

  A driving force transmission device according to the present invention includes a main clutch mechanism, a cam mechanism, and an electromagnetic pilot clutch mechanism between an outer rotating member and an inner rotating member positioned coaxially and rotatably in the outer rotating member. The pilot clutch generated by applying a current to the electromagnetic coil of the pilot clutch mechanism is converted into an axial cam thrust by the cam mechanism, and the main clutch mechanism is converted by the cam thrust. Is a driving force transmission device that performs torque transmission between the rotating members by pressing and engaging the coupling transmission torque generated in the main clutch mechanism by increasing or decreasing the applied current to the electromagnetic coil. It is a driving force transmission device provided with the control apparatus to control.

  FIG. 1 shows a driving force transmission device according to an embodiment of the present invention. The driving force transmission device 10 is configured substantially symmetrically about the axis, and FIG. 1 shows a substantially half cross section about the axis. As shown in FIG. 2, the driving force transmission device 10 is used as a transfer component constituting a four-wheel drive vehicle based on a rear wheel drive, and as shown in FIG. In addition, it is used in the middle of the power transmission path on the rear wheel side of the four-wheel drive vehicle based on the front wheel drive, and although not shown, it is arranged on the power transmission path of the left and right wheels of the vehicle. Then, a usage pattern for constituting the limited slip differential is adopted.

  The four-wheel drive vehicle shown in FIG. 2 is a four-wheel drive vehicle based on a rear wheel drive on which a vertical engine 21 is mounted, and a transfer 23 is provided on the rear side of the transmission 22 disposed on the rear side of the engine 21. I have. 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 transfer 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, an outer case 10a as an outer rotating member, an inner shaft 10b as an inner rotating member, and a main clutch mechanism 10c. The pilot clutch mechanism 10d and the cam mechanism 10e are provided.

  The outer case 10a constituting the driving force transmission device 10 is formed by a cylindrical housing 11a and a rear cover 11b fitted and screwed to a rear end opening of the housing 11a to cover the opening. 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, and the front side wall portion of the housing 11a, the rear cover 11b, Is rotatably supported.

  The inner shaft 10b is spline-fitted with the rear propeller shaft 24a penetrating the inner hole, and is connected to the rear propeller shaft 24a so as to be able 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 mechanism 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 mechanism 10c is assembled to the outer spline 11d of the inner shaft 10b so as to be spline-fitted and movable in the axial direction, and each outer clutch plate 12b is an inner spline of the housing 11a. 11e is spline-fitted and assembled so as to be movable in the axial direction. 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 having the above-described configuration, by energizing the electromagnetic coil 13a of the electromagnet 13, a loop shape through which the magnetic flux circulating through the yoke 16, the rear cover 11b, the friction clutch 14, and the armature 15 passes through the electromagnet 13 as a base point. A circulating magnetic path is formed. The current applied to the electromagnetic coil 13a of the electromagnet 13 is controlled to a predetermined current value set by duty control.

  The energization of the electromagnet 13 with respect to the electromagnetic coil 13a (interruption of applied current) is performed by a manual switch switching operation, and three drive modes to be 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. 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 splined to the outer spline 17a1. It is mated. 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 mechanism 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 13a 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. Therefore, the pilot clutch mechanism 10d is in an inoperative state, and 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 mechanism 10c Inactive state. 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 13 a of the electromagnet 13 of the pilot clutch mechanism 10 d is energized, a loop-shaped circulation magnetic path having the electromagnet 13 as a base point is formed, and magnetic force is generated. Sucks the armature 15. 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 mechanism 10c, presses the main clutch mechanism 10c with the front side wall portion of the housing 11a, and frictionally engages according to the frictional engagement force of the friction clutch 14. Let 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 13a is duty-cycled 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. By controlling, the cam thrust due to the friction 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 13a of the electromagnet 13 is increased to a predetermined value, the attractive force of the electromagnet 13 to the armature 15 increases, and the armature 15 is strongly attracted to increase the frictional engagement force of the friction clutch 14, and both The relative rotation between the cam 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 arranged 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 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 be configured to be connected to a first propeller shaft 24c described later so that torque can be transmitted, 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 outputs the driving force of the engine 21 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.

  Therefore, the driving force transmission device 10 includes an electrical control device 30 that controls transmission torque (coupling transmission torque) generated in the main clutch mechanism 10c by increasing or decreasing the current applied to the electromagnetic coil 13a of the electromagnet 13. ing. As shown in FIG. 4, the electrical control device 30 includes a control device 31 incorporating a microcomputer and a drive circuit, and a front wheel side (left wheel side) and a rear wheel side (right wheel) with the drive force transmission device 10 as a center. The angular velocity detecting means 32a and 32b for detecting the angular velocity of the side) are essential, and the control device 31 controls the increase and decrease of the current applied from the power source 33 to the electromagnetic coil 13a.

  FIG. 5 illustrates elements indispensable for controlling the increase / decrease of the applied current to the electromagnetic coil 13a of the electromagnet 13 by the control device 31. FIG. 5 (a) shows the driving force transmission device 10 as a front wheel-rear wheel (left wheel). (Right wheel) is schematically shown in a state where the coupling transmission torque T and the front-rear wheel (left wheel-right wheel) drive system twist angle Δθ. It is a graph which shows the relationship. Note that ωF displayed in FIG. 5A indicates the angular velocity on the front wheel (left wheel) side, and ωR indicates the angular velocity on the rear wheel (right wheel) side. Further, Tc displayed in FIG. 2B represents the coupling control torque Tc of the coupling transmission torque T, and Δθmax represents the maximum value of the drive system torsion angle that can remain with the coupling control torque Tc.

  The microcomputer constituting the control device 31 starts its operation by starting the engine, executes the control program (A) based on the flowchart shown in FIG. 6, and executes one of the control programs (B) and (C). , Based on the flowchart shown in FIG. 7 or FIG. The control device 31 also executes other control programs for controlling the driving state of the vehicle on which the driving force transmission device 10 is mounted, but the display of the flowchart for executing the control programs is omitted. . The definitions of the elements essential to the control shown in FIGS. 5 to 8 are collectively shown in Table 1.

  The electrical control device 30 increases or decreases the current applied to the electromagnetic coil 13a constituting the pilot clutch mechanism 10d, thereby increasing the torque (cup) between the front wheel (left wheel) and the rear wheel (right wheel) (between the outer case 10a and the inner shaft 10b). The ring transmission torque T) is controlled, and the microcomputer constituting the control device 31 starts operation by starting the engine. First, the control program (A) is executed based on the flowchart shown in FIG. The maximum value Δθs of the torsion angle of the front wheel (left wheel) -rear wheel (right wheel) drive system is stored, and then either of the control programs (B) and (C) is based on the flowchart shown in FIG. 7 or FIG. This is executed to control the coupling transmission torque T.

  In the control program (B) for the coupling transmission torque T shown in FIG. 7, the drive system torsion angle Δθ when the torsion direction of the front wheel (left wheel) -rear wheel (right wheel) drive system is reversed has come close to zero. At this time, the current applied to the electromagnetic coil 13a is reduced to release the cam thrust force remaining in the cam mechanism 10e, and then the main clutch mechanism 10c is reengaged. On the other hand, in the control program (C) for the coupling transmission torque T shown in FIG. 8, the drive system twist angle Δθ when the twist direction of the front wheel (left wheel) -rear wheel (right wheel) drive system is reversed exceeds zero. When a predetermined angle in the reverse direction is reached, the applied current to the electromagnetic coil 13a is reduced, the cam thrust remaining in the cam mechanism 10e is released, and then the main clutch mechanism 10c is reengaged. It is.

  In the execution of the control program (A) that stores the maximum value Δθs of the torsion angle of the front wheel (left wheel) -rear wheel (right wheel) drive system, the microcomputer that constitutes the control device 31 has an angular velocity ωF of the front wheel (left wheel) and From the angular velocity ωR of the rear wheel (right wheel), the relative angle θw of the front wheel (left wheel) -rear wheel (right wheel) drive system is calculated (step 101), and from the coupling control torque Tc and the drive system rigidity characteristics, The drive system maximum torsion angle Δθmax that can remain with the ring control torque Tc is calculated (step 102). The drive system maximum torsion angle Δθmax may be calculated from the graph (mapped) shown in FIG. 5B or may be calculated.

  Next, in step 103, the microcomputer compares the calculated absolute value of the drive system relative angle θw with the calculated absolute value of the remaining drive system maximum torsion angle Δθmax (step 103), and the drive system relative angle. If the absolute value of θw is smaller than the remaining drive system maximum twist angle Δθmax, the front wheel (left wheel) -rear wheel (right wheel) drive system twist angle Δθ is equal to the drive system relative angle θw (step 104). ), If the drive system relative angle θw is equal to or greater than the remaining drive system maximum twist angle Δθmax, the front wheel (left wheel) -rear wheel (right wheel) drive system twist angle Δθ and the remaining drive system maximum Assuming that the twist angle Δθmax is equal (step 105), the control program is advanced to step 106.

  In step 106, the microcomputer determines whether or not the absolute value of the remaining drive system maximum twist angle Δθmax is equal to or greater than a predetermined angle Δθ1, and the absolute value of the remaining drive system maximum twist angle Δθmax is the predetermined angle Δθ1. If it is determined that the absolute value of the drive system torsion angle Δθ is not less than a predetermined angle Δθ2, it is determined in step 107 that the absolute value of the drive system torsion angle Δθ is not less than the predetermined angle Δθ2. If it is determined that the maximum value Δθs of the drive system twist angle is stored in step 108 as the drive system twist angle Δθ.

  On the other hand, if the microcomputer determines in step 106 that the absolute value of the remaining drive system maximum twist angle Δθmax is less than the predetermined angle Δθ1, the microcomputer determines in step 109 the maximum value of the drive system twist angle. Assuming that Δθs is 0, the storage of the maximum value Δθs of the drive system torsion angle is cleared. That is, if the absolute value of the remaining drive system maximum torsion angle Δθmax is less than the predetermined angle Δθ1, it is determined that the energy due to torsion is small, and the storage of the maximum value Δθs of the drive system torsion angle is cleared. . If the microcomputer determines in step 107 that the absolute value of the drive system torsion angle Δθ is less than the predetermined angle Δθ2, the microcomputer stores the control program without storing the maximum value Δθs of the drive system torsion angle. The execution of is terminated.

  When the microcomputer finishes the control of whether or not to store the maximum value Δθs of the drive system torsion angle, either one of the control programs (B) and (C) for the coupling transmission torque T is shown in FIG. Or it performs based on the flowchart shown in FIG.

  In the control program (B) for the coupling transmission torque T shown in FIG. 7, the drive system torsion angle Δθ when the torsion direction of the front wheel (left wheel) -rear wheel (right wheel) drive system is reversed has come close to zero. At this time, the current applied to the electromagnetic coil 13a is reduced to release the cam thrust force remaining in the cam mechanism 10e, and then the main clutch mechanism 10c is reengaged.

  In step 201, the microcomputer determines whether or not the maximum value Δθs of the drive system torsion angle is stored. If the microcomputer determines that the maximum value Δθs of the drive system torsion angle is stored, step 202. To determine whether or not the absolute value of the drive system torsion angle Δθ is equal to or smaller than the predetermined angle Δθ3, and if it is determined that the absolute value of the drive system torsion angle Δθ is equal to or less than the predetermined angle Δθ3, It is determined that the drive system torsion angle Δθ when the direction is reversed has approached zero, and in step 203, the control torque is reduced for a predetermined time to release the cam thrust remaining in the cam mechanism 10e, Thereafter, the main clutch mechanism 10c is re-engaged.

  On the other hand, if the microcomputer determines in step 201 that the maximum value Δθs of the drive system torsion angle is not stored, and in step 202, the microcomputer determines that the absolute value of the drive system torsion angle Δθ is a predetermined angle Δθ3. If it is determined that the control torque is exceeded, execution of the control program is terminated without performing control for reducing the control torque for a predetermined time.

  Thus, in the execution of the control program (B), the applied current to the electromagnetic coil 13a is reduced when the drive system torsion angle Δθ when the torsion direction of the drive system is reversed reaches near zero, and the cam Since the control of releasing the cam thrust remaining in the mechanism 10e and then re-engaging the main clutch mechanism 10c is performed, torque reduction in the main clutch mechanism 10c can be performed in a state in which the twist of the drive system is substantially eliminated. As a result, the occurrence of shock due to torque loss can be prevented.

  The control program (C) for the coupling transmission torque T shown in FIG. 8 is such that the drive system torsion angle Δθ when the torsion direction of the front wheel (left wheel) -rear wheel (right wheel) drive system reverses exceeds zero and the reverse direction When the predetermined angle is reached, the applied current to the electromagnetic coil 13a is reduced, the cam thrust remaining in the cam mechanism 10e is released, and then the main clutch mechanism 10c is re-engaged. .

  In step 301, the microcomputer determines whether or not the maximum value Δθs of the drive system twist angle is stored. If the microcomputer determines that the maximum value Δθs of the drive system twist angle is stored, step 302. To determine whether (drive system twist angle Δθ × maximum value of drive system twist angle Δθs) is less than zero, and (drive system twist angle Δθ × maximum value of drive system twist angle Δθs) is less than zero. In step 303, it is determined whether or not the absolute value of the drive system torsion angle Δθ is equal to or greater than a predetermined angle Δθ4. If it is determined that the angle is equal to or greater than the predetermined angle Δθ4, it is determined that the drive system twist angle Δθ when the twist direction of the drive system is reversed exceeds zero and reaches a predetermined angle in the reverse direction. At 304, the control torque is set for a predetermined time. Hesi and opens the cam thrust remaining in the cam mechanism 10e, then re-engaging the main clutch mechanism 10c.

  On the other hand, if it is determined in step 301 that the maximum value Δθs of the drive system torsion angle is not stored, the microcomputer determines in step 302 (the torsion angle Δθ of the drive system × the maximum value of the drive system torsion angle). If it is determined that (Δθs) is equal to or greater than zero, and if it is determined in step 303 that the absolute value of the drive system torsion angle Δθ is less than the predetermined angle Δθ4, the control torque is reduced by a predetermined time. The execution of the control program is terminated without performing

  Thus, according to the execution of the control program (C), when the drive system twist angle Δθ when the twist direction of the drive system is reversed exceeds zero and reaches a predetermined angle in the reverse direction, the electromagnetic coil The applied current to 13a is reduced, the cam thrust remaining in the cam mechanism 10e is released, and then the main clutch mechanism 10c is re-engaged, so that the twist of the drive system is almost eliminated. In this state, the torque in the main clutch mechanism 10c is reduced, and the occurrence of shock due to torque loss can be prevented. According to the control program (C), in particular, when the driving state is changed to the driving state in which the rotation direction of the drive system is reversed, but the driving state in which the vehicle is immediately returned to the original driving state is adopted, the electromagnetic coil There is an advantage that it is possible to avoid unnecessary control of the applied current to 13a.

It is a fragmentary sectional view of the driving force transmission device concerning one embodiment 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 mounts the drive force transmission device. It is a block diagram which shows the outline of the electrical control apparatus which comprises the driving force transmission apparatus. FIG. 4 is a schematic diagram (a) schematically showing a configuration of a drive system provided with the drive force transmission device, and a graph (b) showing a relationship between the coupling torque T and the drive system twist angle Δθ. 4 is a flowchart for executing a control program (A) for storing a maximum value Δθs of a drive system torsion angle in the drive force transmission device. It is a flowchart for implementing the control program (B) of the coupling transmission torque T in the same driving force transmission device. FIG. 9 is a flowchart for executing a control program (C) for coupling transmission torque T in the driving force transmission apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10A ... Driving force transmission apparatus, 10a ... Outer case, 10b ... Inner shaft, 10c ... Main clutch mechanism, 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 2nd propeller shaft, 25a ... rear differential, 25b ... front differential, 26a ... rear axle shaft, 26b ... rear wheel, 27a ... front axle shaft, 27b ... front wheel, 28 ... transaxle, 30 ... Electrical control means, 31 ... control device, 32a, 32b ... angular velocity detection means, 33 ... power source.

Claims (5)

A main clutch mechanism, a cam mechanism and an electromagnetic pilot clutch mechanism are arranged between the outer rotating member and the inner rotating member positioned coaxially and rotatably in the outer rotating member. A pilot torque generated by applying a current to the electromagnetic coil of the clutch mechanism is converted into an axial cam thrust by the cam mechanism, and the main clutch mechanism is pressed and engaged by the cam thrust. A driving force transmission device that transmits torque between the rotating members, the driving force transmission device including a control device that controls coupling transmission torque generated in the main clutch mechanism by increasing or decreasing an applied current to the electromagnetic coil. The driving force transmission device includes the outer rotating member or the driving path connected to the outer rotating member and the inner rotating member. Or a torsion angle detection means for detecting a torsion angle between the drive path connected to the inner rotating member and the control device reverses the torsion direction of the torsion angle detected by the torsion angle detection means. When the torsion angle at the time of reaching the vicinity of zero, the applied current to the electromagnetic coil is reduced, the cam thrust remaining in the cam mechanism is released, and then the current is applied to the electromagnetic coil to A driving force transmission device that performs control to re-engage a main clutch mechanism. A main clutch mechanism, a cam mechanism and an electromagnetic pilot clutch mechanism are arranged between the outer rotating member and the inner rotating member positioned coaxially and rotatably in the outer rotating member. A pilot torque generated by applying a current to the electromagnetic coil of the clutch mechanism is converted into an axial cam thrust by the cam mechanism, and the main clutch mechanism is pressed and engaged by the cam thrust. A driving force transmission device that transmits torque between the rotating members, the driving force transmission device including a control device that controls coupling transmission torque generated in the main clutch mechanism by increasing or decreasing an applied current to the electromagnetic coil. The driving force transmission device includes the outer rotating member or the driving path connected to the outer rotating member and the inner rotating member. Or a torsion angle detecting means for detecting a torsion angle with respect to the drive path connected to the inner rotating member, and the control device is adapted to reverse the torsion direction detected by the torsion angle detecting means. When the twist angle exceeds zero and reaches a predetermined angle in the reverse direction, the applied current to the electromagnetic coil is reduced, the cam thrust remaining in the cam mechanism is released, and then the current is supplied to the electromagnetic coil. A driving force transmission device that performs application and re-engagement of the main clutch mechanism. The driving force transmission device according to claim 1 or 2 is disposed in a driving path for transmitting the driving force of the engine to the front wheel side and the rear wheel side, and constitutes a front and rear wheel drive vehicle based on the rear wheel drive. A driving force transmission device characterized by that. The driving force transmission device according to claim 1 or 2 is disposed in a driving path for transmitting the driving force of the engine to the rear wheel side, and constitutes a front and rear wheel driving vehicle based on front wheel driving. Driving force transmission device. The driving force transmission device according to claim 1 or 2, wherein the driving force transmission device is disposed in a driving path for transmitting the driving force of the engine to the left wheel side and the right wheel side to constitute a limited slip differential. apparatus.

Images