JPH0331611Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a power transmission device disposed, for example, between the rear axles of 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 first shaft consisting of an input shaft receiving rotational input and a rotating shaft;
A clutch is provided between each clutch and the second output member, and during normal driving, the rotational input from the input member is transmitted through both clutches, and one wheel falls into the mud and the other wheel falls onto the paved road. In some cases, the driving force of the input member can be transmitted to, for example, a first output member corresponding to a wheel on the pavement 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 This invention was devised in view of the above-mentioned conventional problems, and combines the functions of a limited-slip differential differential device and an automatically disconnecting hub clutch.
Moreover, it is an object of the present invention to provide a power transmission device that can improve the running stability by reliable connection of the clutch.

(d) Structure of the invention In order to achieve the above object, this invention includes an input member that receives rotational input, and a separate first member that is rotatable and movable in the axial direction with respect to the input member.
a second output member; first and second output members rotatable and axially movable relative to the first and second output members;
a dog clutch body, the input member and first and second
a cam mechanism provided between the first and second dog clutch bodies; a clutch mechanism provided between the first and second output members and the first and second dog clutch bodies for coupling and releasing the two; a brake means that applies braking force to the second dog clutch body; a shift spring that biases the first and second output members in the clutch engagement direction; and a return bias that biases the first and second dog clutch bodies in the clutch release direction. The structure consists of a spring.

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

FIG. 1 shows an embodiment of this invention, for example
It is placed between the rear axles of FF part-time four-wheel drive vehicles. That is, the case 1, which serves as an input member that receives rotational input, is rotatably provided in the vehicle housing 3 via a bearing 5. A ring gear (not shown) is attached to the flange 7 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 9 and 11 are provided which are rotatably supported with respect to the case 1. The left and right wheel axles are integrally constructed with the first and second output members 9 and 11. Between the first and second output members 9 and 11 and the case 1, there are first and second dog clutches A and B.
is provided.

On the other hand, a second
As shown in the figure, an annular cam body 17 constituting the cam means is spline-fitted, and the left and right sides of this cam body 17 are inclined at a predetermined pressure angle as shown in FIG. A cam surface 17c is formed of a surface 17a and a vertical surface 17b having a pressure angle of approximately zero. In addition, the first and second dog clutches A,
B has first and second dog clutch bodies 19 and 21, as well as first and second driven members 23 and 25 spline-fitted to the first and second output members 9 and 11.

Between the left and right outer end surfaces of the first and second driven members 23 and 25 and the flanges 9a and 11a provided on the outer peripheral surfaces of the first and second output members 9 and 11, a first plate spring is provided. , second elastic body (shift spring)
27 and 29 are interposed, and the first one as the locking claw side,
The second driven members 23 and 25 are elastically supported in the longitudinal direction of the connection movement.

On the cam body 17 side of the first and second dog clutch bodies 19 and 21, as shown in FIG.
5 is formed, and this cam surface 17a and the driven convex surface 35
and constitute a cam mechanism. The first and second dog clutch bodies 19 and 21 and the first and second driven members 23 and 25 are respectively formed with engaging pawls 31a and 33a and locking pawls 23a and 25a which constitute a clutch mechanism. The driven convex surface 35, the locking claws 23a, 25a, and the engaging claws 31a, 33a are formed so that their pressure angles are approximately zero. Reference numeral 37 represents a stopper ring for restricting inward movement of the first and second driven members 23 and 25, and reference numeral 38 represents a return spring for the first and second dog clutch bodies 19 and 21. Further, the first and second dog clutch bodies 1
An arm bar 39, which constitutes a brake means together with a brake shoe to be described later, is fixed to the outer surface of each of the arms 9 and 21, and its tip end is provided on the left and right side walls of the case 1, as shown in FIGS. 1 and 4. It passes through an arcuate long hole 41 and projects outward to the left and right.

On the other hand, a brake holding frame 43 is fitted to the outer circumferential surface of both ends of the case 1 so as to be rotatable relative to the case 1. As shown in FIG. 5, a brake shoe 45 is fitted to the stepped outer circumferential engagement surface 43a of the brake holding frame 43 so as to be slidable relative to the engagement surface 43a. An annular spring 47 is fitted to the outer circumferential surface of the brake shoe 45, and the brake shoe 45 is pressed against the engagement surface 43a by its pressing force. A plurality of locking recesses 49 are provided in the inner surface of the brake shoe 45 in the circumferential direction, and the distal end portion of the arm bar 39 is fitted and locked in the locking recesses 49 .

In addition, on the base end surface of the brake holding frame 43,
As shown in FIG. 6, a plurality of engagement protrusions 51 are formed at equal intervals on the circumference, and on the end face on the housing 3 side, engagement receiving portions corresponding to the engagement protrusions 51 are formed. 53 is formed. The engaging protrusion 51 is removably fitted into the engaging receiving portion 53, and the brake holding frame 43 is held non-rotatably by the housing 3.

One embodiment of this 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 17 spline-coupled to the case 1;
will also rotate as a unit. This cam body 17
As a result of this rotation, the first and second dog clutch bodies 19 and 21, which are cam-engaged with the cam body 17, also tend to rotate. However, in the first and second dog clutch bodies 19 and 21, the brake shoe 45 linked to the arm bar 39 receives frictional resistance from the engagement surface 43a of the brake holding frame 43, and the arm bar 39 moves from the chain line position in FIG. The case 1 and the first and second dog clutch bodies 1 are placed in the relative positions shown by solid lines.
9 and 21 rotate relative to each other. Due to this relative rotation, the cam surface 17c and the driven convex surface 35 are brought into the state shown on the right side in FIG.
9 and 21 move outward in the left and right direction. Then, the engaging claws 3 of the first and second dog clutch bodies 19 and 21
1a, 33a and the locking claws 23a, 25a of the first and second driven members 23, 25 are connected as shown in the right half of FIG. First and second output members 9, 11
is transmitted to the left and right axles (not shown). In this case, the engaging claws 31a, 33a of the first and second dog clutch bodies 19, 21 and the first and second driven members 23,
When the locking claws 23a, 25a of 25 are engaged with each other in a differential manner as shown in FIG. Because it will be done,
The first and second dog clutch bodies 19, 21 receive only rotational force. Then, due to the rotation of the first and second dog clutches 19 and 21, the first and second driven members 2
3 and 25 are retracted in one direction in the direction of arrow P in FIG.
When the locking claws 23a, 25a are opposed to each other between the locking claws 23a, 25a, the urging forces of the first and second elastic bodies 27, 29 cause the locking claws 31a, 33a and the locking claws 23a,
25a is smoothly connected. Therefore, even if the rotational input to the input member 1 causes frequent torque fluctuations due to the accelerator operation of the vehicle, the two claws will not easily become disconnected from each other. Therefore, inconveniences such as the driving force being transmitted to only one wheel when the vehicle is running straight ahead are reduced, and running stability can be improved.

Furthermore, the locking claws 23a, 25a, the engaging claw 31a,
33a is prevented from being damaged. Furthermore, even when the vehicle suddenly starts, the locking claws 23a, 25a and the engaging claws 31
A, 33a can be reliably joined, and the impact at the time of engagement can be alleviated.

During four-wheel drive driving, when the vehicle turns a curve, a difference occurs between the inner and outer wheels. For example, the angular velocity of the first output member 9 on the inner wheel side is smaller than the angular velocity in case 1, so the above action is maintained. , the driving force from the case 1 is continuously transmitted to the inner axle via the first dog clutch body 19. On the other hand, since the angular velocity of the second output member 11 on the outer ring side is greater than the angular velocity of the case 1, in FIG.
7, the second dog clutch body 21 rotates in a direction opposite to that described above. Then, due to the biasing force of the return spring 38, the second dog clutch body 2
The driven convex surface 35 of No. 1 is removed from the cam surface 17 of the cam body 17. As a result, as shown on the left side of FIG. 3, the pawl 33a of the second dog clutch body 21 and the second driven member 2
The engagement of the pawl 25a of No. 5 is released, the left rear wheel axle becomes in a free rotating state, and the differential between the two rear wheels is absorbed, allowing smooth curve travel.

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 9 Since the angular velocity never becomes greater than the angular velocity in case 1, the connection of the corresponding first dog clutch A is maintained. 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 rotational input to case 1 is stopped. Ru.
On the other hand, the first and second output members 9 and 11 are rotationally driven by receiving driving force from the road surface of the left and right wheels.
Therefore, due to this switching from four wheels to two wheels, the angular velocity of the first and second output members 9 and 11 becomes larger than the angular velocity of case 1 (ultimately zero), and as a result, as described above, Then, the relationship between the cam body 17 and the first and second dog clutches 19 and 21 becomes the state shown on the left side of FIG. 3, and the first and second dog clutches A and B are disconnected. Therefore, the first and second output members 9, 11
The left and right wheels spin freely, reducing running resistance.

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. It can also be placed between the front wheel axles.

(f) Effects of the invention As is clear from the above, according to the structure of this invention, it is possible to provide the function of a limited-slip differential differential device and the function of an auto hub. 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. Furthermore, by reliable connection of the clutch, it is possible to prevent the driving force from being transmitted only to one side during straight running, etc., and it is possible to improve running stability.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted sectional view of a differential device showing a first embodiment of this invention, and Fig. 2 is a partially omitted cross-sectional view of a differential device showing a first embodiment of this invention.
Fig. 3 is a detailed sectional view showing the cam joint between the dog clutch body and the cam body;
1, FIG. 5 is a cross-sectional view taken along the line -- in FIG. 1, FIG. 6 is a cross-sectional view taken along the line -- in FIG. 1, and FIG. 7 is an explanatory view of the operation. DESCRIPTION OF SYMBOLS 1... Case (input member), 9... First output member, 11... Second output member, 17... Cam body (cam means), 19... First dog clutch body, 21
...Second dog clutch body, 27...First elastic body, 29...Second elastic body, 23a, 25a...Latching claw, 31a, 33a...Engaging claw, A...First dog clutch, B... ...Second Dog Clutch.

Claims (1)

[Scope of utility model registration request] an input member that receives rotational input; separate first and second output members that are rotatable with respect to the input member and movable in the axial direction; and rotatable with respect to the first and second output members. a cam mechanism provided between the input member and the first and second dog clutch bodies; a cam mechanism provided between the first and second output members and a first , second
a clutch mechanism provided between the dog clutch body and the clutch mechanism for coupling and releasing the two;
a brake means for applying a braking force to the dog clutch body; a shift spring for biasing the first and second output members in the clutch coupling direction;
A power transmission device consisting of a return spring that biases the dog clutch body in the direction of releasing the clutch.