JPS6364826A - Power transmission for four-wheel drive car - Google Patents

Abstract

PURPOSE:To enable effective transmission of a drive force and engine brake to four wheels, by a method wherein an engaging part, regulating the one rotation of a one-way clutch is mounted to a slide sleeve. CONSTITUTION:Clutch cone parts 35c and 36c are formed in the middle of the outer periphery of outer races 35a and 36a mounted to one-way clutches 35 and 36 for forward running and reversing. An inner spline 39a, selectively engageably and disengageably with the one of the two outer races 35d and 36d, is formed approximately to the central part of a slide sleeve 39, into which outer races 35a and 36a of one-way clutches 35 and 36. Axial movement of clutch balls 40c and 41c of cam grooves 40b and 41b of outer races 40a and 41a of free running clutches 40 and 41 for direct coupling during reversing and forward running secured to both end parts of a slide sleeve 39 is regulated by means of retainers 40d and 41d.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a power transmission device for a four-wheel drive vehicle that can selectively switch engine drive modes with a simple operation. [Problems solved by conventional technology and inventions] In general, when steering an IJJ vehicle, the turning radius of the front wheels is larger than that of the rear wheels, and the average rotation speed of the front wheels is lower than the average rotation speed of the rear wheels. Become more than numbers. Therefore, for example, in a power transmission system for a four-wheel drive vehicle disclosed in Japanese Patent Application Laid-Open No. 55-4292, in which the front wheel drive system and the rear wheel drive system are directly connected via a gangway, Since the front wheels and rear wheels are always driven at the same rotation speed, tight corner braking occurs when the vehicle speed is below a predetermined speed during steering. As a result, the internal circulation torque of the drive system increases, resulting in an increase in steering force, a decrease in driving force, and a deterioration in fuel consumption. To deal with this, for example, Japanese Patent Application Laid-Open No. IJri60-1522
The June bulletin states that the driving force of the rear wheels is transmitted to the front wheels through a transfer device that uses a one-way clutch to the right.
A technique for avoiding a tight corner braking phenomenon during steering has been disclosed. By the way, in this prior art, the inner spline of the slide sleeve inserted into the one-way clutch and connected to the rear wheel drive system is connected to the forward one-way clutch and
By selectively engaging the outer splines formed in the one-way clutch for reverse, the one-way clutch for forward movement or
This allows for an increase in the rotational speed of the front wheels relative to the rear wheels when turning when reversing. However, when driving on a road with a low friction coefficient in the above-mentioned four-wheel drive mode or transitioning from high-speed driving to deceleration driving, the engine brake is applied to the rear wheels, while the front wheels rotate when the one-way clutch is OFF. This makes it difficult to effectively transmit the engine brake to the front wheels. In order to transmit the engine brake to not only the rear wheels but also the front wheels, the rotation of the front wheels can be restricted by connecting the slide sleeve to the one-way clutch for reverse during deceleration, but the one-way clutch for forward When driving in direct four-wheel drive by switching the inner spline of the slide sleeve that is fed to the outer spline of the above to the outer spline of the non-way clutch for reversing during deceleration or while driving on a low friction coefficient road surface. , Since the rotation speeds of both one-way clutches are relatively fluctuating, the reverse one-way clutch is changed to Il[ to release the direct four-wheel drive state.
= When you do this, so-called sticking occurs and the direct 4W
There may be cases where it becomes difficult to smoothly perform the switching operation to cancel D. [Object of the Invention] The present invention has been made in view of the above circumstances, and it not only allows good drivability to be obtained by freeing the rotation of the front wheels by using one forward clutch when steering in a constant four-wheel drive state. , effectively prevents a decrease in driving force and deterioration of fuel consumption rate, and also allows for low friction coefficient road running.
Alternatively, when driving at deceleration, you can automatically switch to so-called direct-coupled 4WD, or switch from direct-coupling 4WD to free 4WD.
When switching to the front wheel, the switching operation can be performed quickly without causing any jamming between the sleeves, and the driving force and engine brake can be effectively transmitted not only to the rear wheels but also to the front wheels. - The object of the present invention is to provide a power transmission device for a four-wheel drive vehicle that eliminates the nabraking phenomenon. [Means for Solving the Problems] The power transmission device for a four-wheel drive vehicle according to the present invention has three
A pair of one-way clutches, one for forward and one for reverse, which allow rotation in opposite directions, are installed on one side of the drive shift II lift connected to the front drive system and the drive shift shift connected to the front drive system. A slide sleeve 1 is connected to the other of the two shafts and is inserted through the one-way clutches so as to be movable in the axial direction. The engaging part that restricts the rotation of one side and the clutch cone part formed on both one-way clutches are engaged with each other.
A pair of contact-type free-running clamps are provided to support a removable clutch roller. However, when driving on a road with a low friction coefficient or decelerating in a straight line, when the engaging part of the slide sleeve is engaged with the one-way clutch for Moedo, the contact type provided on this slide sleeve Clutch [1-L] of the free running clutch is sandwiched between the clutch cone of the IU one-way clutch, and the simultaneous movement of both one-way clutches is regulated, so that a so-called direct-coupled four-wheel drive mode is performed. Furthermore, during steering, the clutch roller of the contact type free running clamp slides against the clutch cone of the reverse one-way clamp while the engaging part of the slide sleeve remains engaged with the forward one-way clamp. freely

[ru. As a result, the increase in the number of rotations of the front wheels relative to the rear wheels during steering is reduced to an appropriate level of 21 by the frictional transfer of the clutch roller, and tight corner braking is avoided. [Embodiments of the Invention] The present invention will be described in detail below with reference to the drawings. The drawings relate to one embodiment of the present invention, and FIG. 1 is a sectional view of the transfer device, FIG. 2 is an enlarged view of the main parts of the transfer device during forward direct coupling four-wheel drive, and FIG. 3 is an enlarged view of the same during steering. Figure 4 is an enlarged view of the same when 4-wheel drive is directly connected to reverse, Figure 5 is an enlarged view of the same when reverse steering is performed, Figure 6 is an enlarged view of the same when 2-wheel drive is driven, and Figure 7 is an enlarged view of the same when reverse steering is performed.
The figure is a circuit diagram of the hydraulic control system, Figure 8 is a schematic diagram of the drive system, Figure 9 is a TX-IX sectional view of Figure 3, Figure 10 is a sectional view from X to X of Figure 2, and Figure 11. is a sectional view taken along line XI-XI in FIG. 5, FIG. 12 is a sectional view taken along line x-xi in FIG. 4, FIG.
Fig. 15 is an enlarged view of section XV in Fig. 3, Fig. 16 is an enlarged view of section XVI in Fig. 14, and Fig. 17 is an enlarged view of section X in Fig. 3.
Fig. 18 is an enlarged view of part XVI in Fig. 12, Fig. 1
FIG. 9 is a characteristic diagram showing the opening degree of the bypass passage on the vertical axis and the steering angle of the front wheels on the horizontal axis. As shown in FIG. 8, the four-wheel drive vehicle according to the present invention is constructed based on a rear engine rear drive (RR) vehicle, and includes an X-engine body 1 mounted at the rear of the φ body.
1 is connected to a drive device 12 equipped with a clutch, a transmission, etc. Furthermore, this drive 8 device 12 transmits power to the rear wheels 13,
3 in the II differential arrangement pull device 15! I
! It is set up. Marζ, top deal 1? A differential device 15 is connected to the propeller shaft II shaft 17 via a transnoring device r116. Furthermore, this propeller shirt 1-17 is connected to a front differential device 18, and a front wheel 19 is connected to this front differential device 518 via a front axle 20. Further, the counter shirts 1 to 21 are mounted on the transfer case 16 a of the transfer device 16 with a bearing 22 .
It is rotatably arranged through the . A transfer clutch 23 and a direction changing gear r24 are mounted on the counter shift shaft 21, and the transfer clutch 23 is connected to the V differential VlE.
15 ring gear 15a, transformer 77 gear\no 25
are connected via. Further, a bevel gear 27a formed at the base end of a bevel gear driven shaft 27 supported by the transfer case 16a via a bearing 26 is meshed with the direction conversion gear 24 that is mounted on the counter shaft 11 foot 21. There is. On the other hand, a front drive spline 28 is installed at the distal end of the bevel gear driven shaft 27, and the movement of the front drive spline 28 in the thrust direction is restricted by the holding portions U29a and 29b. Further, the tip 2 of the bevel gear driven shaft 27
7b is the bearing 3 attached to the transformer 77 case 16a.
The bevel 1 is relatively rotatably supported via a needle bearing 32 in a recess 31a bored at the proximal end of the noft 31 of the bevel 1, which is supported via the bevel 1. The surface is a locking member 33 such as a retainer plate or a needle bearing.
It is locked to. Furthermore, the front drive seat P
A tip 31b of the foot 31 is splined to a universal joint 34 connected to the propeller shirt 17. In addition, (in part 1) of the front drive shift 31,
A forward one-way clutch 35 and a reverse one-way clutch 36 are each mounted on a shaft, and one end surfaces of outer races 35a and 36a of each one-way clutch 35, 36 are opposed to each other via a needle bearing 37 so as to be relatively rotatable. ing. Further, sprags 35b, 36 are provided between the outer races 35a, 36a and the front drive shaft 31.
b are each interposed with τ. The sprag 35b of the forward one-way clap 35 (
Moreover, the rotation of the outer race 35E1 only in the direction around the opposite portion 81 (normal rotation direction) in FIG. 9 is transmitted to the front drive shift 31. In addition, the sprag 3 of the one-way clap 36 for reversing
6b rotates the outer race 36a only in the clockwise direction in FIG.
1. Furthermore, each one-way clutch 3 for forward and reverse
5. The above outer races 35a and 36a provided in 36
Clutch cone portions 35c, 36c are formed midway around the outer periphery of the outer races 35a, 36a and expand toward the axially opposing end surfaces of the outer races 35a, 36a. Furthermore, outer splines 35d and 36d are formed on the outer peripheries of mutually opposing ends of each of the outer races 35a and 36a, respectively. Furthermore, a slide sleeve 39 is inserted through the outer races 35a and 36a of both one-way clutches 35 and 36. Almost in the center of this slide sleeve 39,
The above-mentioned inner and outer splines 35d. Internal spline 3 that selectively engages with one side of 36d @releasable
9a is formed. Further, at both ends of the slide sleeve 39, a free running clutch 40 for direct connection during backward movement and a free running clutch 4 for direct connection during forward movement are provided.
One outer race 40a, 41a is fixedly installed, and redevelop plates 40d, 41d are abutted on both sides thereof. On the outer race 41a of the free running clutch 41 for direct connection during forward movement, a plurality of cams tM41b each having an arcuate outer circumference are formed at regular intervals as shown in FIG. As shown in FIG. 12, the above-mentioned free running clutch 40 for use with
b are formed at regular intervals. Furthermore, the cam grooves 4 of each of the outer races 40a and 41a are
A clutch ball 40C141C is attached to 0b and 41b, and the movement of this clutch ball 40C941c in the axial direction is caused by the retainer 40d. 41d. In addition, the cam grooves 40b of the outer races 40a and 41a
, 41b and the narrow side wall surface at one end of the cam grooves 40b, 41b. A compression spring 42 that presses in the direction is interposed in each case. In addition, as shown in FIGS. 15 and 17, the outer races 35a and 36a of both one-way clutches 35 and 36 are
The clutch cone portions 35c and 36C provided in the outer races 35a and 36a have flange portions 35f and 36f continuously formed from the shaft diameter portions 35e and 36e to the diameter φd1 on the right side of the diameter φdO of the outer races 35a and 36a, and the flange portion 35f. , 36f to the diameter φd2, and the sliding semi-connections 35q, 36o further expand to the diameter φd3.
The stopper portions 35i, 36i are further expanded by a diameter φd4 from the lock portions 35h, 36h (φdo).
(φdl<φd2<φd3 (φd+). On the other hand, as shown in FIGS. 16 and 18, the seven outer races 40a of both free running clutches 40 and 41,
The inner diameter portion of 41a is the one-way clutch 35.36.
Maximum diameter parts 35i, 36 of 7 outer races 35a, 36a
The diameter φd5, which is larger than the diameter φd4 of i, is on the right (φd
4<φds). Furthermore, the cam Fm4 of the outer races 40a and 41a
0b, 41b are the sliding guide parts 40e, 41e, and the sliding guide parts 40a, 41e are 3! T! Continuing cam part 4
It is composed of 0f and 41f. When the clutch balls 40c, 41G are located in the sliding guide portions 40e, 41e, the diameter φd6 of the portion of the clutch balls 40C, 41C that faces the shaft diameter portions 35e, 36e of the outer races 35a, 36a is , is larger than the diameter φd of the shaft diameter portions 35e and 36e, and is set to be the minimum sliding cone portion φd1 of the sliding semi-coupled portions 35CJ and 36g (φdo<φd6
．． φd6−φdl). Further, when the clutch balls 40c, 41c are moved to the cam portions 40f, 41f of the cam grooves 40b, 41b, the clutch balls 40c. The diameter φdb of the outer race 35a, 3
The lock portions 35h and 36h of 6a are held in the middle of the diameter between φd2 and φd3 (φd2, φd6<φd3).
). Further, as shown in FIG. 6, the slide sleeve 39
When the inner spline 39a formed approximately at the center of the outer races 35a, 36a is located at the center of the outer races 35a, 36a, the inner spline 39a
It does not engage with any of the outer splines 35d and 36C1 formed on the spline 6a, and is held at a neutral position. Further, the span L between the clutch balls 40c and 41a held at both ends of the slide sleeve 39 is equal to the span L between the clutch cone portions 3 of the outer races 35a and 36a.
It is wider than the span A1 between the inclined bases of the outer races 35a and 36C, and narrower than the distance J22 between the end faces of the outer races 35a and 36a (J2t<L<j22). On the other hand, the tip of a connecting drum 43 is fixed to the end surface of the slide sleeve 39 on the side on which the free running clutch 40 is fixed via a guide rail 44 formed in an annular shape. Further, an internal spline 43a is formed at the base of the connecting drum 43, and this internal spline 43a is slidably engaged in the axial direction with an external spline 28a of a front drive spline 28 mounted on the bevel gear driven shaft 27. has been done. In addition, selectoff, 1-945 is attached to the guide rail 44.
A fork portion 45a formed at the tip of is engaged to be slidable in the circumferential direction. In addition, this selectoff A-ri 45
One end of a select rod 46 is fixed to the base end of the select rod 46, and the other end of the select rod 46 penetrates the transfer case 16a and projects outward, and is attached to the transfer case 16a via a bracket 47. The plunger 1v48a of the vacuum actuator 48 is connected via a select 1-arm 49. Further, a locking groove 46a having a V-shaped cross section is formed in the middle of the select rod 46 to set the 2WD position. Furthermore, the locking iM of the select rod 46
A protrusion 46b indicating the 2WD position is formed on the circumferentially opposite side of the protrusion 46a. Furthermore, recesses 46c and 46d of a predetermined width are continuously formed on both sides of the protrusion 46b in the axial direction. Furthermore, in the locking groove 46a of the select rod 46V),
A plunger 50 connected to a 2WD position setting solenoid 50 fixed to the transfer case 16a.
a are arranged opposite to each other so that they can be freely engaged and detached. Further, a protrusion 46b formed on the select rod 46
A lock ball 52 is attached to the transfer case 16a via a return spring 51 so as to be able to move forward and backward.
are arranged opposite to each other, and this lock ball 52 is connected to the protrusion 4.
6b, the plunger 50a of the solenoid 50 is set to be opposed to the locking member M46a. Further, as shown in FIG. 7, operating chambers (not shown) partitioned on both sides of the diaphragm in which the plunger 48a of the vacuum actuator 48 is fixedly installed move forward through the passages 53a and 53b. and a vacuum switching valve (VSV) 54 for retraction and a vacuum switching valve (VSV) 55 for retraction, respectively. Each of the VSVs 54 and 55 is connected to the passages 53a and 53b.
On the other hand, the atmospheric passages 56a and 56b are selectively connected to a negative pressure passage 58 communicating with a negative pressure source 57 such as a vacuum pump, and when the coils 54a and 55a are excited, the passage 53a . 53b and the negative pressure source 57 are communicated. Furthermore, the passages 53a and 53b communicating with the respective operating chambers formed across the diaphragm (not shown) of the vacuum actuator 48 are communicated via a bypass passage 53c, and a control solenoid is directly connected to the bypass passage 53c. The needle valve 59a connected to 59 is
The bypass passage 53C is faced so that b1 can be freely closed. Further, referring to FIG. 7, the control circuit 60 will be explained as follows.
A coil 64a of a forward/reverse switching relay 64 is connected to the brake valve 61 via an ignition switch 62 and a reverse switch 63, and the coil 64a is roughly connected to ground 65. Further, a reverse lamp 66 is connected between the reverse switch 63 and the coil 64a of the forward/reverse switching relay 64. Further, the 2WD position fixing solenoid 50 and a coil 68a of a 2WD relay 68 are connected in parallel to the ignition switch 62 and reverse switch 63 via a 2WD holding switch 67. Furthermore, the coil 68a of this 2WD relay 68 is connected to the 2WD relay 68.
A 2WD position switch 71 is connected via a No. 11 warning light 69 and a timer 70. Further, the contact 71a of this 2WD position switch 71 is connected to the select rod 4.
The lock ball 52 is connected to the lock ball 52 which is provided opposite to the protrusion 46b of No. 6. Further, a steering angle sensor 72 is connected between the ignition switch 62 and the reverse switch 63, and this steering angle sensor 72 is connected to a control circuit 73. This control circuit 73 also includes a 4WD direct connection switch 74.
The direct control solenoid 59 is connected through the solenoid 59. The steering angle sensor 72 is a rotary or linear potentiometer that detects the steering angle of the front wheels 19, and as shown in FIG. 19, a signal corresponding to the steering angle of the front wheels 19 is sent to the control circuit. 73. Further, a changeover switch 68b of the 2WD relay 68 is connected between the ignition switch 62 and the steering angle sensor 72, and the changeover switch 68b
One contact 68c of the VSV 54.55 is connected to the terminals 54a and 55a of the VSVs 54 and 55, respectively. Furthermore, both coils 54a. 55a is the contact 5s 64 of the forward/reverse switching relay 6/1.
The changeover switch 64d connected to the ground 65 of the forward/reverse changeover relay 64 is the contact 64b. 64c. Next, the operation of the power transmission device with the above configuration will be explained. (Operation in forward direct-coupling 4WD mode) When driving straight, when the 4WD direct-coupling switch 74 is turned on, the front wheel 1
9 is directed straight ahead, the turning angle sensor 72 that detects the turning angle of the front wheels 19 does not output a reliable μ signal, and therefore the control circuit 73 outputs the υ11i0 signal for direct control. No output to solenoid 59. As a result, the 4WD direct coupling switch 74 remains in the ON state, the needle valve 59a of the direct coupling control solenoid 59 remains protruded, and the vacuum actuator 48
passages 5 communicating with mutually opposing movements 9 (not shown) of the
A bypass passage 53c communicating between 3a and 53b is blocked. On the other hand, in this state, the coil 68a of the 2WD relay 68
X and the coil 64a of the forward/backward switching relay 64 are not excited, and the changeover switches 64d, 68b of both the relays 64, 68 remain connected to the contacts 64b, 68c. Therefore, the current from the battery 61 is applied to the coil 64a of the forward vacuum switch valve (VSV) 54, and this coil 54a is energized, causing the plunger 48a of the vacuum actuator 48 to move backward (towards the left in the figure). ) is connected to a negative pressure 1I9157 such as a vacuum pump. As a result, the negative pressure generated in the negative pressure source 57 is transferred to the operating chamber through the negative pressure passage 58, the forward movement section 5v54, and the passage 53.
It flows in through a. Then, the brange 48a/fiI of the bar 48 moves backward, and this plunge? A select rod 46 connected to 48a via a select arm 49 is moved in the same direction, and the select fork 4 connected to this select rod 46
The fork portion 45a of No. 5 presses and urges the connecting drum 43 to the left in FIG. 1 via the guide rail 44. ξ, the inner spline 43a formed on the connecting drum 43 is connected to the outer spline 28 of the front drive spline 28 which is mounted on the bevel gear driven shaft V-lift 27.
a and moved in the same direction, and at the same time, this connected drum 43) 1! The installed slide sleeve 39 is moved in the same direction. During this time, the 2WD holding switch 67 of the control circuit 6o is in the OFF state, and the plunger 50a of the solenoid 50 communicating with the 2WD holding switch 67 receives the force of the solenoid spring (not shown) and moves upward in FIG. The locking groove 46a formed in the direct rod 46 is spaced apart from the locking groove 46a. In addition, the above select 0
The lock ball 52 pressed against the protrusion 46b formed on the circumferential side of the protrusion 46 is in the recess 4 formed next to it.
The contact 71a of the 2WD position switch 71 connected to the lock ball 52 is turned off by being relatively moved toward the 6d side and projected by the biasing force of the return spring 51. An inner spline 39a formed approximately at the center of the slide sleeve 39 is engaged with an outer spline 35d formed on the outer periphery of an outer race 35a of a forward one-way clutch 35 mounted on the base of the front drive shaft 31. Ru. At the same time, the clutch ball 40c of the free running clutch 40 for direct connection during reverse, which is provided at one end of the slide sleeve 39, is moved to the shaft diameter portion 35e of the outer race 35a, while the clutch ball 40c is provided at the other end of the slide sleeve 39. The clutch ball 41C of the free running clutch 41 that has been moved is transferred to the lock portion 36h formed in the flag-cone portion 36c of the outer race 36a of the II running one-way clutch 367 installed opposite to the forward one-way clutch 35 (the second (Status shown in Figure 2). A gap equal to φd6 minus φd is formed between the shaft diameter portion 35e of the outer race 35a and the clutch ball 40C of the free running clutch 40, so the clutch ball 40C becomes free. This clutch ball 40C is a cam tfls4 formed on the outer race 40a of the free running clutch 40.
0b, the Pi moving element 11 portion 40e is moved under the urging force of the compression spring 42, and the free running clutch 40 for direct connection during this backward movement is turned off. On the other hand, the free running clutch 4 has been moved to the lock portion 36h of the clutch cone portion 36c formed on the outer race 36a of the one-way clutch 36 for reverse.
The clutch ball 41C of No. 1 is connected to this Otsukku part 36h,
Outer race 41 of the free running clutch 41
The direct connection 4 when moving forward is sandwiched between the cam grooves 41b formed in the
Wheel drive condition is obtained. At this time, approximately half of the driving force output from the engine body 11 is transferred from the rear differential device 15 to the bevel gear driven shaft 27 of the transfer device 16 via the transfer lug 23, the counter shaft 21, and the direction conversion gear 24. The signal is transmitted via a bevel gear 27a formed at the base end of the bevel gear driven shaft 27. Then, the bevel gear driven shaft 27 rotates, and the bevel gear driven shaft 27 rotates.
The connecting drum 43, which is spline-coupled to the front drive spline 28, rotates in the same direction. As a result, the slide sleeve 39 connected to the connecting drum 43 rotates counterclockwise in FIG. 9. Then, the outer race 35a of the forward one-way clutch 35 is rotated in the same direction via the outer spline 35d that meshes with the inner spline 39a of the slide sleeve 39, and the rotational force of the outer race 35a is applied to the sprag 35.
b to the front drive shaft 31. Then, the driving force is applied to the front drive shaft 3.
From the tip of E31b to the universal joint 34 and the propeller shaft 17, connect the front differential to the front differential 7 range V1.
Aifi18, this front differential 62f18. Front wheel 19 via front axle 20
is rotated. As a result, the above-mentioned rear wheel 1 in steady running on flat ground
3 and the front wheels 19 are rotationally driven at a ratio of approximately 1:1. Also, if the mode shifts to deceleration operation in this state, the front wheels 19
And rotational force is reversely applied from the rear wheel 13 to the engine main body 11. Meanwhile, driving force is transmitted from the front wheels 19 to the front drive shaft 31 via the front axle 20, the front differential device 18, the propeller shaft 17, and the universal joint 34. The rotational force from the front wheel 19 transmitted to the front drive shaft 31 is transmitted to the outer race 36a via the sprag 36b of the IIJI one-way clutch 36. Then, this outer race 36a is rotated in the counterclockwise direction in FIG. is moved in the same direction by frictional force against the urging force of . As a result, this clutch ball 41c is attached to the cam portion 4 of the cam groove 41b formed in the outer race 41a of the free running clutch 41.
1f (see Fig. 16), and the outer race 3
The rotational force from 6a is applied to the outer race 4 of the free running clutch 41 via the clutch ball 41C.
1a. In this manner, the clutch ball 41c is engaged with the cam portion 41f of the cam groove 41b by the counterclockwise rotation of the outer race 36a, so that the axial inclination of the clutch cone portion 36c can be reduced. Accordingly, the thrust reaction force from the clutch ball 41C during switching during 4WD direct coupling operation is reduced, and operability is improved. Then, the rotational force transmitted to the outer race 41a is transmitted from the connecting drum 43 to the rear differential arrangement 11 in a light road, which is opposite to the transmission direction during steady running on a flat surface. This rear differential arrangement 11 device 15 is connected to the driving force from the rear wheels 13 to the ψ axle 1.
4, and the driving force of this rear wheel 13,
The resultant force of the driving forces of the front wheels 19 is transmitted to the engine body 11 via the drive device 12, and engine braking is applied. (Operation in forward semi-coupled 4WD mode) Furthermore, when moving from straight running to cornering, the steering angle sensor 72 of the control circuit 60 detects the steering angle of one of the front wheels, and adjusts the turning angle of the corner. A suitable signal is output to the control circuit 73. Then, from this control circuit 73, a 4WD direct connection switch 74 is connected.
The @4 control signal is output to the direct-coupling control solenoid 59 via the direct-coupling control solenoid 59, and the needle pulp 59a of the direct-coupling control solenoid 59 moves backward by an amount corresponding to the υ control signal, opening the bypass passage 53C. do. As shown in FIG. 19, the opening degree of the bypass passage 53c is determined when the steering angle of the front wheels 19 is 01. It gradually increases in proportion to θ2 and θ3. Then, the bypass passage 53c communicating with the negative pressure source 57
A part of the negative pressure flowing into the negative pressure chamber of the vacuum actuator 48 is transferred to the atmosphere from the atmosphere passage 56b provided in the retreating VSV 55 via the bypass passage 53C1 and the communication passage 53b. leaked to. As a result, the negative pressure m flowing into a negative pressure chamber (not shown) communicating with the bypass passage 53c of the vacuum actuator 48 is reduced, and the plunger 48a of the vacuum actuator 48 moves in the protruding direction by that amount. be done. Then, the selection fork 45 is attached to this plunger 48a.
The slide sleeve 39 connected to the front wheel 19 is moved to the right in FIG. 2 by an amount corresponding to the steering angle of the front wheel 19 while being supported by the connecting drum 43. As a result, the clutch ball 40c of the free running clutch 40 for direct connection during reverse, which is provided on one side of the slide sleeve 39, is pressed by the retainer plate 1-406, and is formed on the outer race 35a of the one-way clutch 35 for forward movement. The clutch cone portion 35 is placed on the shaft diameter portion 35e.
Transfer to direction c. At fi1, the clutch ball 41C of the free running clutch 41 for city road direct connection provided at the other end of the slide sleeve 39 is pressed against the retainer plate 41d, and the clutch cone portion 36C of the outer race 36a is pressed.
From the lock portion 36h formed in the sliding semi-coupled portion 36g (
(see FIG. 15) and is transferred to 1FII (state in FIG. 3). Then, the clutch ball 41c becomes in a sliding semi-coupled state with the outer race 36Q of the one-way reverse clutch 36. Meanwhile, the inner spline 39a formed on the slide sleeve 39 is connected to the outer spline 3 formed on the outer race 35a of the forward one-way clutch 35.
5d remains engaged. During cornering, when the front wheel 19 tries to turn with a larger curvature than the rear wheel 13, the rotation speed of the front wheel 19 becomes higher than the rotation speed of the rear wheel 13, and the front wheel 19 is connected to the front wheel 19. The rotation speed of the front drive shaft 31 becomes higher than the rotation speed of the bevel gear driven shaft 27. Then, the front dry foot 31 rotates counterclockwise relatively faster than the bevel gear driven shaft 27. As a result, the outer race 36a of the one-way clutch 36 for reverse rotation rotates relatively quickly via the sprag 36b, and the clutch ball 41C of the free running clutch 41 for direct connection during forward movement is semi-coupled, so that the front drive By appropriately transmitting power to the shaft 31, the so-called tight corner braking phenomenon during cornering can be avoided, and smooth cornering performance can be achieved without slipping. Then, when the cornering travel returns to straight travel, the detection output signal of the steering angle sensor 72 becomes static, and the direct connection control solenoid 59 turns OFF. As a result of step A, the needle valve 59a of the direct control solenoid 59 operates to project, thereby blocking the bypass passage 53C. In other words, the vacuum actuator 48 moves backward by the plunge +p 48 Q /fi, and the clutch ball 41C of the free running clutch 41 moves at the mW
The running one-way clutch 6 is stopped by being stopped by a stopper portion 361 formed on the outer race 36a. As a result, the slide sleeve 39 is returned to the state shown in FIG. 2, and the 4WD direct connection need is set again. At this time, the inner spline 39a formed on the slide sleeve 39 remains engaged with the outer spline 35d formed on the outer race 35a of the forward one-way clutch 35, and only the clutch ball 41C is transferred. Therefore, switching can be done smoothly. (Operation in FF2 direct-reverse 4WD mode) In addition, when the reverse straight drive is turned on, when the reverse switch 63 of the control circuit 60 is turned on, the reverse lamp 66 is turned on and the forward/reverse switching relay 64 is turned on. The coil 64a is excited and the changeover switch 64d is connected to the contact 64c. As a result, the power supply to the coil 54a of the forward VSV 54 is cut off, and the atmospheric passage 5 of the forward VSV 54 is cut off.
6a, a negative pressure chamber (
(not shown) is connected to the passage 53a. At the same time, the coil 558 of the retreating VSV 55 is excited, and the negative pressure passage 58 communicating with the negative pressure source 57 operates in a negative pressure chamber (not shown) that operates in the direction of protruding the plunge 1/48a of the vacuum actuator 48. ) Passageway 5 communicating with
3b. Then, the plunger 48a is projected, and the selection rod 46 is moved in the same direction as the plunger 48a is projected, and the lock ball 5 is moved in the same direction.
2 is moved relative to the recess 46G formed on the circumferential side of the select rod 46, and the 2WD position switch 71 is turned OFF. Note that at this time, the lock ball 52 is inserted into the recess 46.
When relatively moving from d to the recess 46c side, the protrusion 46
b, the 2WD position switch 71 is turned O once.
However, since the timer 70 is connected to the 2WD position switch 71, no current flows immediately and the coil 68a of the 2WD relay 68 is not excited. Then, a select fork 45 fixed to the select rod 46 gradually moves the slide sleeve 39 to the right in FIG. 3 while being supported by the connecting drum 43. Then, the inner spline 39a formed approximately at the center of the slide sleeve 39 comes off from the outer spline 35d formed on the outer race 35a of the forward one-way clutch 35, and then this inner spline 3
9a is engaged with an outer spline 36d formed on the outer race 36a of the reverse one-way clutch 36. At the same time, the clutch ball 40c of the free running clutch 40 for reverse direct connection fixed to one side of the slide sleeve 39 is connected to the one-way clutch 35 for forward movement.
The clutch cone portion 3 formed on the outer race 35Q of
5c (see FIG. 17), and the clutch ball 41c of the free-running clutch 41 for direct connection during forward movement, which is fixed on the other side of the slide sleeve 39, is engaged with the lock portion 35h (see FIG. 17) of the one-way clutch 36 for reverse movement. is moved to the shaft diameter portion 36e formed on the outer race 36a (the state shown in FIG. 4). A gap equal to φd6 minus φd is formed between the shaft diameter portion 36e of the outer race 36a and the clutch ball 41c of the free running clutch 41 for direct connection during forward movement.
is moved within the cam f14Ib formed on the outer race 41a of the free running clutch 41 to the sliding guide portion 41e under the urging force of the compression spring 42,
The clutch of the free running clamp 41 for direct connection during forward movement is released. Next, when the direct-coupled 4WD travels backward, the rear wheels 13 are rotated in the opposite direction, and the connecting drum 43 is rotated through the bevel gear driven shaft 27 at the time 51 in FIG.
The rotational force is applied to the inner spline 3.
It is transmitted to the outer race 36a of the reverse one-way clutch 36 via the 9a1 outer spline 36d. As a result, this rotational force is transmitted to the front drive shaft 31 via the sprag 36b, and the front drive shaft 31 is rotated in the opposite direction. The front wheels 19 are rotated in the opposite direction, and the vehicle is driven straight in reverse. (Operation in reverse semi-coupled 4WD mode) Then, when the front wheels 19 are steered when reversing, the steered angle sensor 72 of the control circuit 60 detects the steered angle and outputs it to the control circuit 73. . Then, the above f, control circuit 7
3, the i control signal is output to the directly connected υ control solenoid 59, and the needle valve 59a of the directly connected all+ control solenoid 59 opens the bypass passage 53c in accordance with the turning angle of one of the front wheels. Then, the negative pressure flowing from the passage 53b into the negative pressure chamber of the vacuum actuator 48 is attenuated, and the plunge p of the vacuum actuator 48 is reduced accordingly.
48a performs a backward movement. Then, the slide sleeve 39 connected to this plunge 1748a is moved to the left in FIG. 4 by an amount corresponding to the steering angle of the front wheel 19, and as a result, the free running clutch for direct connection during forward movement is moved. 41 clutch balls 41C are pressed by the retainer plate 41d, and the clutch cone portion 36 passes over the shaft diameter portion 360 formed on the outer race 36a of the IJ raw one-way clutch 6.
Transferred to G direction. At the same time, the clutch ball 40C of the free running clutch 40 is pressed by the retainer plate 40d and moves from the lock portion 36h formed in the clutch cone portion 35c of the outer race 35a to the sliding semi-coupled portion 35q (see FIG. 17). Saroku No. 5
state). The clutch ball 40c is PIIF against the outer race 35a of the one-way clutch 35 for turning.
This causes J1 semi-binding. During this period, the inner spline 39a formed on the slide sleeve 39 remains engaged with the outer spline 36d formed on the outer race 36a of the one-way retraction clutch 36. When the vehicle turns, the front wheels 19 turn with a large turning radius, so the number of rotations of the front wheels 19 becomes higher than the number of rotations of the rear wheels 13, and the front drive shaft 31 rotates accordingly. Compared to the bevel gear driven shaft 27, it rotates relatively quickly in the clockwise direction in FIG. As a result, the seven outer races 35a of the forward one-way clutch 35 rotate relatively quickly via the sprags 35b, but since the clutch ball 40c of the free running clutch 40 is semi-coupled, this rotational force is not allowed. In addition, an appropriate driving force is transmitted to the front drive shaft 31 via the clutch ball 40c, so that a smooth direction change operation can be performed without slipping. And 1. When the direction change operation L is completed and the front wheels 19 are returned to their original positions, the detection signal of the steering angle sensor 72 becomes zero, and the needle valves 59a of the five direct-coupled control solenoids operate to protrude, causing the bypass The passage 53c is closed. As a result, the plunger 48a of the vacuum actuator 48 moves forward, and the slide sleeve 39 is returned to the state shown in FIG. 4, and the reverse 4WD direct connection mode is again set. (Operation in 2WD mode) On the other hand, when trying to obtain 2WD:U needle when being towed, speedometer verification, or brake performance verification, first set the 2WD holding switch 67 to 0N.
-Jru. Next, the shift lever is switched slowly several times from a desired forward range or from neutral to reverse range. Then, the control circuit 60
The reverse switch 63 is operated 0N10FF, during which time the negative pressure generated in the negative pressure source 57 is selectively flowed into the negative pressure chamber (not shown) of the vacuum actuator 48 through the VSVs 54 and 55. The plunger 48a of the vacuum actuator 48 repeatedly protrudes or retreats. The select rod 46 reciprocates in conjunction with the plunge t48a. During this time, since the 2WD holding switch 67 is turned on, the plunger 50a is urged in the projecting direction, and the tip of the plunger tP50a is connected to the select rod 46.
It is engaged with a locking groove 46a formed in. Then, the position of the select rod 46 is fixed, and at the same time, the lock ball 52 is engaged with the protrusion 46b formed on the select rod 46, and the lock ball 52 is engaged with the protrusion 46b formed on the select rod 46.
Contact point 71 of 2WD position switch 71 connected to 2
a is pressed against the urging force of the return spring 51, and the 2WD position switch 71 is turned on. Then, the timer 70 is activated, and after a predetermined period of time has elapsed, the contact of the timer 70 is turned ON, the coil 68a of the 2WD relay 68 is energized, and the 2WD warning light 69 is activated.
is lit. When the coil 68a is excited, the changeover switch 68
b is separated from the contact 68c, and both of the above ■5V54.55
The current to the coils 54a and 55a is cut off,
Plunger 48a of the vacuum actuator 48
is held in a neutral position. On the other hand, when the plunger 50a of the solenoid 50 is engaged with the locking groove 46a of the select rod 46, the slide sleeve 39 is moved to the neutral position via the select fork 45 connected to the select rod 46. The inner splines 398 formed on the three slide sleeves face between the outer splines 35d and 36d formed on the one-way clutch 35, 36, and are fixed to both ends of the slide sleeve 39. Clutch balls 40c, 41c of both free running clutches 40.41 are connected to both one-way clutches 35.
36 to the shaft diameter portions 35e, 36c of the outer races 35a, 36a. As a result, the space between the slide sleeve 39 and both one-way clutches 35 and 36 becomes free, and the transmission of driving force from the beveled driven shafts 1 to 27 to the front drive shaft 31 is cut off, and the transmission of driving force to the front drive shaft 31 is cut off. Only 13 rotates in 2WD mode. Note that the power transmission device according to the present invention is not limited to the above-mentioned practical example. For example, the one-way clutch 35, 36 is not limited to a sprag type clutch, but may be a ball type clutch if the driving force is relatively low, such as a light suspended vehicle. It may be. In addition, a forward one-way clutch 35 and a reverse one-way clutch 36 are connected to the bevel gear driven shaft 27.
H, and a slide sleeve 39 may be provided on the front drive shaft 31. [Effects of the Invention] As explained above, according to the present invention, one of the drive shaft connected to the power transmission system of the rear wheel drive section and the drive shaft connected to the front wheel drive system has a drive shaft connected to the drive shaft connected to the power transmission system of the rear wheel drive section and a drive shaft connected to the front wheel drive system. A pair of one-way clutches for forward movement and one for reverse movement are provided, and a slide sleeve is connected to the other of the two shafts and is inserted through the two one-way clutches so as to be movable in the axial direction. Furthermore, this slide sleeve has an engaging part that restricts the rotation of one of the two one-way clutches, and a clutch roller that can be freely engaged and disengaged from the clutch cone part formed on both one-way clutches. Since a pair of contact type free running clutches are provided, during steady running or decelerating operation, the engaging portion of the slide sleeve is engaged with one of the one-way clutches to control rotation. By controlling the rotation of the other one-way clutch by the clutch ball of the contact-type free running clutch that engages the clutch cone, so-called direct four-wheel drive is obtained, and the driving force and engine brake are controlled by four-wheel drive. It can be effectively transmitted to the circle. Furthermore, when steering, the engagement part of the slide sleeve is engaged with one of the one-way clutches, and the clutch ball of the free running clutch is released from the clutch two part of the other one-way clutch, thereby steering the front wheels. Allows an increase in rotation speed for the rear wheels of
Tight corner braking phenomenon can be avoided. As a result, the internal circulation torque is reduced and the steering force during steering is reduced, preventing slippage and not only providing good drivability but also reducing driving force and fuel consumption. is prevented. Furthermore, since the rotation of one side of each one-way clutch is selectively regulated by the clutch ball of the free-running clutch, it is impossible to switch between direct-coupled four-wheel drive and so-called sliding semi-coupled four-wheel drive. It can be done smoothly without any problems. In addition, by transferring the clutch ball in the rotational direction and regulating its rotation, the thrust load against the clutch cone can be reduced, which reduces the clutch operation load and improves operability. . Furthermore, by releasing the engagement of the slide sleeves with respect to each of the one-way clutches and the rotation restriction by the free running clutch, the two-wheel drive mode can be selected in the cylinder. As a result, the power transmission device according to the present invention can switch from four-wheel drive in a free state using a one-way forward clutch to direct four-wheel drive when traveling straight, semi-coupled four-wheel drive when turning, and two-wheel drive. , an excellent effect can be achieved in that the switching operation can be performed easily and smoothly.

[Brief explanation of the drawing]

The drawings relate to one embodiment of the present invention, and FIG. 1 is a sectional view of the transfer device, FIG. 2 is an enlarged view of the main parts of the transfer device during forward direct coupling four-wheel drive, and FIG. The same enlarged view, Fig. 4 is the same enlarged view when 4-wheel drive is directly connected to reverse, Fig. 5 is the same enlarged view when reverse steering is performed, Fig. 6 is the same enlarged view when 2-wheel drive is applied,
Fig. 7 is a circuit diagram of the hydraulic ITL control system, Fig. 8 is a schematic diagram of the drive system, Fig. 9 is a sectional view taken along line IX-IX in Fig. 3, and Fig. 10 is a sectional view taken along line XX in Fig. 3. Figure 11 is XI-X in Figure 5.
IX cross-sectional view Figure 12 is the xn-xm cross-sectional view of Figure 4,
Figure 3 is Figure 3 (7) XIII-XIII location plan, No. 14
The figure is an enlarged view of section XIV in Figure 10, and Figure 15 is an enlarged view of section X in Figure 3.
An enlarged view of the v part, Figure 16 is an enlarged view of the X V1 part of Figure 14,
Figure 17 is an enlarged view of section XVI in Figure 3, and Figure 18 is an enlarged view of section 12.
FIG. 19, which is an enlarged view of the X section in the figure, is a characteristic diagram in which the vertical axis shows the opening degree of the bypass passage and the horizontal axis shows the steering angle of the front wheels. 15.18...Power transmission system, 1G...Transfer uffl, 27...Drab shaft, 31...Drive shaft, 35.36...One-way clutch,
35a, 36a-outer lace, 35c, 36c...
Clutch cone part, 39...Slide sleeve, 39
a... Engaging portion, 40.41... Contact type free running clutch, 40c, 41c... Clutch ball. Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18

Claims (1)

[Claims] One of the driven shaft connected to the power transmission system of the rear wheel drive section and the drive shaft connected to the front wheel drive system,
A pair of forward and reverse one-way clutches that allow rotation in opposite directions are arranged in series, and a slide sleeve is inserted into the other of the two shafts so as to be movable in the axial direction with respect to the two one-way clutches. The slide sleeve further includes an engaging portion that restricts the rotation of one of the two one-way clutches, and a clutch roller that can be freely engaged and disengaged from the clutch cone portion formed on the two one-way clutches. A power transmission device for a four-wheel drive vehicle, characterized in that a pair of contact free running clutches are provided.