JPH0451697B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a power transmission device disposed between the rear axles of, for example, a front-wheel drive part-time four-wheel drive vehicle.

(b) Technical background and problems As a conventional power transmission device of this type,
-There is one described in Publication No. 184322. That is,
A clutch is provided between an input member that receives rotational input and first and second output members consisting of a rotating shaft, and during normal driving, rotational input from the input member is transmitted through both clutches, When one wheel falls on muddy ground and the other wheel is on a paved road, the driving force of the input member can be transmitted to, for example, the first output member corresponding to the wheel on the paved road side. Further, when the vehicle is cornering, the clutch on the side corresponding to the increase in the angular velocity of the outer wheel is automatically disengaged, so that, for example, the second output member corresponding to the outer wheel can be idled.

However, in such conventional power transmission devices, the input member and both output members are connected by a clutch unless there is a difference in angular velocity between the first output member and the second output member. When the engine is installed between the rear axles of a 4-wheel drive and is used for 2-wheel drive driving, the interlock between the engine and the input member can be cut off by disconnecting the 2-wheel or 4-wheel switching clutch. 1. The propeller shaft is rotated via the second output member and the input member, resulting in extremely large running resistance.
Therefore, this type of power transmission device also requires a rear wheel hub clutch.

(c) Purpose of the Invention The present invention was devised in view of the above-mentioned conventional problems, and an object of the present invention is to provide a power transmission device that combines the functions of a differential control type differential device and a hub clutch.

(d) Structure of the Invention In order to achieve the above object, the present invention provides an input member that receives rotational input, first and second output members rotatably supported with respect to the input member, and the input member and the input member. First and second clutch members are provided between the first and second output members and are movable relative to the first and second output members to connect and disconnect the input member and the first and second output members; , by moving the first and second clutch members when the input member rotates faster than the first and second clutch members, the input member and the first and second output members are connected via the first and second clutch members. and a first cam means connecting the first and second output members when the first and second output members rotate faster than the input member.
The present invention is configured to include a second cam means for releasing the connection by the second clutch member, and a brake means for applying a braking force in the rotational direction to the first and second clutch members.

(E) Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows an embodiment of the invention, for example
It is placed between the rear axles of FF part-time four-wheel drive vehicles. That is, a case 1 serving as an input member receiving a rotational input is rotatably provided in a housing 3 on the vehicle body side via a bearing 5. A ring gear (not shown) is attached to the flange 2 of the case 1, and this ring gear is engaged with a drive pinion (not shown).

At the center of rotation of the case 1, first and second output members 7 and 9 are provided which are rotatably supported with respect to the case 1. Nuts 11 and 13 are rotatably provided on the back sides of the first and second output members 7 and 9, and left and right rear wheel shafts (not shown) are spline-fitted to the first and second output members 7 and 9. ) are screwed together. , Therefore, the left and right wheel axles are the first and second wheel axles.
It is constructed integrally with the output members 7 and 9. First and second clutches A and B are provided between the first and second output members 7 and 9 and the case 1. Specifically, the outer peripheral surfaces of the first output members 7 and 9 are formed with tapered surfaces 7a and 9a whose diameters decrease toward the center of the case 1.

On the other hand, a second
As shown in the figure, an annular cam body 15 constituting the cam means is spline-fitted, and mountain-shaped cam surfaces 15a are formed on both left and right sides of the cam body 15, as shown in Figure 3. has been done. Said first,
Cone clutch bodies 17 and 19 as first and second clutch members are rotatably fitted to the outer circumferential surfaces of the second output members 7 and 9, that is, the tapered surfaces 7a and 9a, respectively. The inner circumferential surfaces of the cone clutch bodies 17 and 19 have approximately the same taper as the tapered surfaces 7a and 9a of the first and second output members 7 and 9. Tapered surfaces 17a and 19a are formed to reduce the diameter, and are configured to be movable in the thrust direction relative to the tapered surfaces 7a and 9a of the corresponding first and second output members 7 and 9. Cone clutch body 17,
As shown in FIG. 3, the base end surface of the cam member 19 has a driven concave surface 2 which is cam-coupled with the cam surface 15a of the cam body 15.
1 is formed. A cam mechanism 2 for releasing the clutch is provided between the left and right outer end surfaces of the cone clutch bodies 17, 19 and the inner end surface 1a of the case 1 facing the outer end surfaces of the cone clutch bodies 17, 19.
3 is provided. As shown in FIG. 3, this cam mechanism 23 consists of a cam 25 on the inner end surface 1a and a driven cam 27 on the cone clutch bodies 17, 19.
The cam 25 faces the cam body 15, and the driven cam 2
7 is arranged to correspond to the driven concave surface 21 in position. A return spring 28 is disposed between the cone clutch bodies 17, 19 and the inner end surface 1a of the case 1, which always biases the cone clutch bodies 17, 19 in the direction of releasing the clutch. Also,
An arm bar 29 is fixed to the outer surface of the cone clutch bodies 17, 19, and constitutes a brake means together with a brake shoe, which will be described later, and its tip end is shown in FIG.
As shown in FIG. 4, it passes through an arc-shaped elongated hole 31 provided in the side wall 1a of the case 1 and protrudes outward from the left and right.

On the other hand, a brake holding frame 33 is fitted to the outer circumferential surface of both sides of the case 1 so as to be rotatable relative to the case 1. As shown in FIG. 5, a plurality of brake shoes 35 are fitted into the stepped outer circumferential engagement surface 33a of the brake holding frame 33 so as to be slidable relative to the engagement surface 33a. An annular spring 37 is fitted on the outer peripheral surface of the brake shoe 35.
The brake shoe 35 presses against the engagement surface 33 with its pressing force.
It is pressed against a. A plurality of locking recesses 39 are provided in the inner surface of the brake shoe 35 in the circumferential direction, and the distal end portion of the arm bar 29 is fitted and locked in the locking recesses 39.

In addition, on the base end surface of the brake holding frame 33,
As shown in FIG. 6, a plurality of engagement protrusions 41 are formed at equal intervals on the circumference, and on the other hand, engagement receiving portions corresponding to the engagement protrusions 41 are provided on the end face on the housing 3 side. 43 is formed. The engaging protrusion 41 is removably fitted into the engaging receiving portion 43, and the brake holding frame 33 is held non-rotatably by the housing 3.

One embodiment of the present invention has the above configuration, and its operation will be explained next.

First, when the vehicle runs in four-wheel drive, the case 1 receives rotational input via a ring gear (not shown). And, along with the rotation of this case 1,
A cam body 15 spline-coupled to the case 1
will also rotate as a unit. This cam body 15
As the cone clutch bodies 17 and 19 are cam-connected to the cam body 15, the cone clutch bodies 17 and 19 also tend to rotate. However, this cone clutch body 17, 19
The brake shoe 35 connected to the arm bar 29 receives frictional resistance from the engaging surface 33a of the brake holding frame 33, so that the arm bar 29 moves from the position indicated by the chain line in FIG. 4 to the position indicated by the solid line. , the case 1 and the cone clutch bodies 17, 19 rotate relative to each other. Due to this relative rotation, the cam surface 15a and the driven concave surface 21
3, the driven concave surface 21 runs over the cam surface 15a, and the cone clutch bodies 17, 19 move outward in the left-right direction. and cone clutch bodies 17, 19 and the first
Each tapered surface 7a and 17a of the second output member 7, 9,
9a and 19a are pressed together as shown in the right half of Figure 1,
Rotational input from the case 1 is transmitted to left and right axles (not shown) via left and right clutches A and B, and first and second output members 7 and 9.

During this four-wheel drive driving, when the vehicle turns a curve, a differential is generated between the inner and outer wheels, and for example, the angular velocity of the first output member 7 on the inner wheel side is smaller than the angular velocity of case 1, so the above effect is maintained. Continued case 1
The driving force from the cone clutch body 17 is continuously transmitted to the inner axle. On the other hand, since the angular velocity of the second output member 9 on the outer ring side is greater than the angular velocity of the case 1, the cam body 15 in FIG.
The cone clutch body 19 rotates in the opposite direction. At this time, the cam mechanism 23 for releasing the clutch is actuated by the relative movement between the case 1 and the cone clutch body 19, and the cone clutch body 19 is pushed toward the cam body 15 side as shown in FIGS. 7 and 8. do. Due to this pressure, the clutch is reliably released even if the tapered surfaces 9a and 19a are tightly attached, and the driven concave surface 21 is completely fitted into the cam surface 15a with the help of the bias of the return spring 28. . As a result, cone clutch body 1
A gap is created between the tapered surface 19a of the second output member 9 and the tapered surface 9a of the second output member 9 as shown in the left half of FIG. It is possible to drive smoothly around curves.

Furthermore, even when one rear wheel, for example the left rear wheel, falls into muddy ground and slips during four-wheel drive driving, the right rear wheel receives resistance from the road surface, so the first output member 7 Since the angular velocity never becomes greater than the angular velocity in case 1, the corresponding clutch A remains engaged. Therefore, it is easy to drive on rough roads.

Next, when driving by switching from four-wheel drive to two-wheel drive, a well-known switching device cuts off the power connection between the engine and the rear drive shaft, and the rotation input to case 1 is stopped. Ru. On the other hand, the left and right wheels receive driving force from the road surface, and the first and second output members 7 and 9 are rotationally driven. Therefore, due to this switching from four wheels to two wheels, the angular velocity of the first and second output members 7 and 9 becomes larger than the angular velocity of the case 1 (ultimately zero), and as a result,
As mentioned above, the cam body 15 and the cone clutch body 1
7 and 19 becomes the state shown on the left side of FIG. 3, and both clutches A and B are disconnected.

Therefore, from the first and second output members 7 and 9 to the left and right wheels idle, it is possible to reduce running resistance. In this case, the cam mechanism 23 for releasing the clutch
The tapered surfaces 7a, 9a and the tapered surface 17a,
19a is reliably disconnected, there is no variation in idling of the left and right wheels, and running stability is improved.

9 and 10 show a second embodiment of the invention, in which dog clutches are used as clutches A and B. FIG. In this case, the dog clutch bodies 17 and 19 as the first and second clutch members are the first and second clutch members.
The second output members 7 and 9 are engaged with claws, and compared to frictional engagement using cone clutch bodies, power transmission to the left and right wheels is more reliable, and further stability in running direction can be achieved. In addition, in the case of this dog clutch, the claws 45, 47 that constitute the clutch part
Inclined surfaces 45a and 47a are formed on the sides and serve as a cam mechanism for releasing the clutch. other configurations,
Since the operation is substantially the same as that of the above-mentioned embodiment, the same reference numerals are given and the explanation will be omitted.

Note that this invention is not limited to the above embodiments. For example, it can be applied to full-time four-wheel drive vehicles, etc. In this case, the wheels automatically spin when the vehicle decelerates, making it possible to avoid a decrease in the vehicle's retained energy and contributing to improved fuel efficiency.

(F) Effects of the Invention As is clear from the above, according to the configuration of the present invention, it is possible to provide the function of a limited-slip differential differential device and the function of a hub clutch. Therefore, when applied to a part-time four-wheel drive vehicle, the hub clutch can be omitted, and when applied to a full-time four-wheel drive vehicle, fuel efficiency can be improved.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a differential device showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line - - in Fig. 1, and Fig. 3 shows a cam joint between a cone clutch body and a cam body. Detailed sectional view, FIG. 4 is a sectional view taken along the - line in FIG. 1, FIG. 5 is a sectional view taken along the - line in FIG. 1, FIG. 6 is a sectional view taken along the - line in FIG.
FIG. 8 is an explanatory view of the operation, FIG. 9 is a cross-sectional view of another embodiment, and FIG. 10 is a detailed cross-sectional view showing the cam coupling portion. 1... Case (input member), 7... First output member,
9...Second output member, A...First clutch, B...Second
Clutch.

Claims (1)

[Claims] 1. An input member that receives rotational input, first and second output members that are rotatably supported with respect to the input member, and a first and second output member that is provided at each part between the input member and the first and second output members. 1. First and second clutch members that can move relative to the second output member to connect and disconnect the input member and the first and second output members, and the input member rotates faster than the first and second clutch members. By moving the first and second clutch members, the input member and the first,
a first cam means for connecting the second output member; and a second cam means for releasing the connection by the first and second clutch members when the first and second output members rotate faster than the input member; A power transmission device comprising a brake means for applying a braking force in a rotational direction to the first and second clutch members.