JPS60237242A - Differential device for vehicle - Google Patents

Abstract

PURPOSE:To achieve a smaller differential limiting torque at low speeds and a larger torque at intermediate and high speeds by an arrangement in which the differential limiting torque is transmitted between differential gears and a differential large gear at a predetermined vehicle speed. CONSTITUTION:Friction plates 17, 18 which are slidable in the axial direction are disposed in a bulging part 131 of the differential gear box 13, and a friction plate 19 is slidably attached to the shaft 163 of the differential large gear 161 between the friction plates 17, 18. A pressure plate 20 is also attached to the shaft 163 with its movement to the right being limited, and the friction plates 17, 18, 19 are pressed by a disc spring 21 against the pressure plate to form a friction clutch (a). When a differential movement is generated between the wheel axles 81, 82 to cause the differential large gear 161 to rotate relative to the differential gear box 13, a friction force is generated between the friction plates 17, 18, 19 and the pressure plate 20, and the resultant torque Ta is transmitted to the differential large gear 161.

Description

[Detailed Description of the Invention] Relating to a differential device that enables left and right drive wheels to be differentially operated by a differential gear mechanism - When a vehicle as described above performs a turning motion, the rolling distance of the left and right drive wheels is In order to prevent either one of the drive wheels from slipping due to the difference in radius, a differential device is provided that enables differential movement of the left and right drive wheels. A differential gear mechanism consisting of a differential gear box, a small differential gear, and a large differential gear is usually used as this differential device, but in such a differential device, both drive wheels always have the same As the torque is increased, one of the drive wheels may become stuck in mud, snow, or ice.
Also, when one drive wheel lifts during hooning, the transmission torque of the other wheel decreases.1. Driving performance deteriorates. Therefore, a differential limiting device is known as a differential limiting device that generates effective friction torque within the differential to increase the torque transmitted to the wheels on the low speed rotation side.

In the present invention, in such a differential limiting device, when the running speeds of the two vehicles are low, the differential limiting torque (the above-mentioned friction torque) l is reduced to sufficiently match the differential between the left and right driven wheels,
In medium and high speed ranges, the differential limiting torque is increased so that, for example, when one wheel floats, a large torque can be transmitted to the grounded wheel.The present invention is particularly suitable for use in motor tricycles. . That is, in a tricycle, turning in medium to high speed ranges is often performed with one wheel floating, and at this time, it is desirable to be able to transmit large torque to the drive wheel on the ground contact side. Furthermore, turns at low speeds are performed with both drive wheels in contact with the ground, and turns with a large difference in rotational speed between the left and right drive wheels, such as U-turns and small turns, are performed at low speeds. It is desirable that movement is not hindered12
stomach. The present invention satisfies these requirements; in addition, even when turning with both wheels on the ground at medium to high speeds, a differential effect can be obtained when driving on areas where the friction coefficient of the road surface is large ( If the coefficient of stretch on the road surface is relatively small, it is possible to turn the vehicle sufficiently due to tire slip even without a differential effect).

The present invention will be explained below with reference to illustrated embodiments. Fig. 1 is an overall perspective view of a tricycle to which the present invention is applied.

This tricycle has one steering wheel 3 linked to a handle 2 at the front of a body 1, and a pair of left and right driving wheels 5.5 linked to an engine 4vC at the rear, each wheel 3.5. 5
is constructed with relatively wide balloon tire wheels. 6
is a saddle, and steps 7 for a pair of left and right feet f2 are provided below both sides of the saddle. Axle 8 of each drive wheel 5.5
．． 8, they are connected to each other via a differential gear 10 driven by a propulsion shaft 9.

In step 7, the ground contact center of the turning wheel 3 and the driving wheel 5 are
If the driver shifts his weight to either of the steps 6 and 7, the vehicle body 1
tilts to the same side, and the drive wheels 5 on the opposite side leave the road surface, and the vehicle body 1 is in a state where it is in contact with the ground with two wheels: the steering wheel 3 on the morning side and the drive wheel 5 on the rear side that is in contact with the ground. In this state, by swinging the front steering wheel 3, the running direction of the entire vehicle body 1 can be changed, and at medium to high speeds, turning is mainly performed by tilting the vehicle body 1 in this manner.

FIG. 2 is a sectional view of the differential gear 1o. The reduction/JN gear 11 fixed to the propulsion shaft 9 meshes with the large reduction gear 12, and the large reduction gear 12 is fixed to the differential gear box 13. A small differential gear shaft 14 that is perpendicular to the rotational axis of the large reduction gear 12 is pivotally mounted on the differential gear box 13, and a small differential gear shaft 14 is mounted on both ends of the small differential gear shaft 4, respectively. Gear +11+! 5. A differential large gear 16. is fixed and mounted on the right axle 81. and a large differential gear 16 mounted on the left axle 8□. It meshes with the two.

In such a differential device, as is well known, the drive torque of the propulsion shaft 9 is combined with the drive torque of the axle 8. and 82. is transmitted evenly to
Normally, each member from the differential gear box 13 to the axle 8 rotates as a unit, but when turning, the differential pinion 15 rotates on the shaft 14.
Both vehicles 11118.
+ s, are differential (rotate at different rotational speeds). However, one axle, for example 8. Both axles 8. even when the load is reduced. , s.

produces a differential and axle 8. rotates at high speed and axle 8. L rotates at a low speed, but at this time the axle 8. [The transmitted torque is the axle 8. is limited and reduced by the torque transmitted to the A differential limiting device is therefore provided in such a case to limit the differential movement between the two axles 81.8 and increase the torque transmitted to the axle 82.

That is, in the illustrated embodiment, the differential gear box 13 has a t2 constant portion 13□ that projects leftward in the figure, and this projecting portion 13. A friction plate 17 that is slidable in the axial direction, [
A friction plate [9 is a large differential gear 16. Shaft 16. VC is also a pressure plate m
ICN shown in FIG. 1 is mounted so that its rightward movement is restricted, and the friction plates 17, 8, 19 are pushed toward the pressure plate side by a disc spring 21 to form a friction clutch a. Therefore, a frictional force is generated between both axles 8+-8t, and the resulting torque Tα is transmitted to the large differential gear ■61.
This torque Ta is, for example, the axle 8. is on the high speed side, the axle 8. It acts in the direction of decelerating the differential pinion 1.
The torque through I7 increases by Tα. At the same time, both axles 8. ．． 8. The rotational speed difference between the two cars also decreases, and when the wheel behavior torque is smaller than the torque Ta, both cars fi11
18182 rotates as a unit.

In this embodiment, the differential limiting torque Tα provided by the friction clutch a is set to a relatively low value, and both axles 8. - 82 is a comb that is easy to differentially move - A second friction clutch b is also provided, and this friction clutch b is activated during medium to high speed driving.

The friction clutch b includes the pressure plate 20 and the differential gear box portion 1.
3. Friction plates η1, η2 and 24+-, 24 are interposed between the pressure plate 22 loosely fitted into the cylindrical inner hole 26 of the cylindrical inner hole 26, and these are pressed against each other by disc springs. , the inner hole 26 also has a pressure plate 22vC adjacent to it.
- The engagement ring 27 is loosely fitted in the same way, and as shown in FIG. 29 IF
,, are engaged.

Differential gear box part 13. There is also a centrifugal weight 3 inside the
0 is swingably supported by a support shaft 31.

The centrifugal weight recesses are provided in two as shown in FIG. is provided with a stepped portion 33 for engagement, and as the vehicle speed and the rotational speed of the differential gear box 13 increases, the centrifugal weight 3
0 overcomes the force of the spring 32 due to the centrifugal force and floats outward, and when the rotational speed reaches a predetermined value, the engaging portion 34 of the centrifugal weight 30 engages with the stepped portion 33, and the engaging ring 27 rotates integrally with the differential gear box 13 via the centrifugal weight 30.

The differential limiting torque Tb is applied to the differential large gear 16 by the friction force generated in the friction clutch b by the pressing force of the disc spring.
VCC express delivery available.

The engagement ring 27 and the pressure plate 22 are connected to the protrusion path and V as described above.
Since they are connected by the letter-shaped groove 29, the engagement ring 2
At the same time as 70 rotational force is delivered to the pressure plate 22vC, the fourth
As shown in the figure, the pressure plate 22 is pushed toward the pressure plate by the tangential force F of the engagement ring 27 with a pressing force P corresponding to tanO. Therefore, the pressing force P is applied to the friction clutch b in addition to the pressing force of the disc spring B, and the differential limiting torque transmitted via the friction clutch b is T A +
& = b. ΔTA is proportional to the driving torque.

The pressing force P is also transmitted to the friction clutch a through the pressure plate 20g, so the friction clutch a is similarly moved to 4F1-
The differential limiting torque transmitted is TfZ+△Ta,
△T (Z is proportional to the driving torque. Figures 5 and 6 are diagrams showing the relationship between the differential limiting torque and the driving torque described above. In other words, the differential limiting torque causes one wheel to float. The driving torque transmitted from the engine, that is, the pinion shaft torque Tρ, is the ordinate of the maximum driving torque TL on the ground side in
The horizontal coordinate can be considered to be the coefficient of friction of the road surface.

In FIG. 5, the differential limiting torque TL that can be transmitted when the centrifugal way 30 is associated with the engagement ring 27 is indicated by the line AECD.

The line AE indicates the maximum torque Ta+'l'5 that can be transmitted by the friction clutches α and b only by the pressing forces of the disc springs 21 and 5, but in this section, the driving torque TD
is smaller than the above Tα+T6, so one differential large gear 16+
, L5a and the differential gear box 13 rotate together. , 1ilBo, the increasing torque △Ta+△TA is proportional to the above-mentioned initial torque Ta+Tb and driving torque TI).
is added, and TL increases in proportion to TI). In this section, TL≧Tp (TL-Tc in M))
Then, as in section AB, the differential gear 16. S16. The differential gear box 13 rotates as a unit, and if TL<T, then -T exceeds TL, as shown by point iBo', and differential movement between the two axles 81.8□ becomes possible. When one wheel floats, the torque TL shown by the dotted line BO' is transmitted to the wheel on the ground side.

When the differential limiting torque TL- reaches the zero point, T does not increase any further due to the characteristics of the disc spring 21. Therefore, from now on, when the jumping torque T increases, both axles 8. ．． 82 differentials are possible. This means that the differential gear is activated when the vehicle is traveling on a road surface with a large coefficient of friction.

Figure 6 shows the relationship between differential limiting torque and drive torque at low speed (that is, centrifugal way) when 30 is not connected to engagement ring n.In this case, differential limiting torque is equal to Since there is only a small friction torque TIZ, the differential device works effectively except when the driving torque is extremely small.

Furthermore, as can be seen from FIGS. 5 and 6, when one wheel floats at medium or high speeds, a relatively large sliding torque h'' is transmitted to the ground-contacting wheel.

As described above, the drive device of the present invention transmits the differential limiting torque between the differential gear box and the large differential gear in response to the vehicle speed when the vehicle speed exceeds a predetermined value. When the vehicle is running at low speed with the left and right drive wheels in contact with the ground,
Both drive wheels are relatively freely and lightly differential 1. In addition to being able to respond to the turning movement of the vehicle at medium to high speeds, when turning with one wheel floating, it is possible to transmit a relatively large drive torque to the drive wheel on the ground side. It is particularly excellent as a differential device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a tricycle equipped with a differential device according to the present invention, FIG. 2 is a cross-sectional view of the differential device according to the present invention, and FIG. 3 is a cross-sectional view taken along line m-■ in FIG. Figure 4 is IV- of Figure 2.
5 and 6 are diagrams showing the relationship between differential limiting torque and drive torque. DESCRIPTION OF SYMBOLS 1...Vehicle body, 2...Nohendru, 3...Steering wheel, 4...Engine, 5...Driving wheel, 6...-Saddle, 7...Step, 8... Axle , 9... Propulsion shaft, 10... Differential device, 11... Reduction small gear, 12...
...Reduction large gear, I3...Differential gear box, 14...Differential small gear shaft, 15...Differential small gear, 16...Differential large gear, 17, [8,19... ...Friction plate, pressure plate, 21...disc spring, 22...pressure plate-23-24.
...[4 plates, 5...disc springs, songs...inner holes, 27...
・Engagement ring, ah...protrusion, 29...groove, (9)・
... Centrifugal weight, 31... Support shaft, 32... Spring,
33... Engagement stepped portion, 34... Engagement portion. Agent: Patent Attorney Nozomi Ehara, 2 people Figure 3 11 Figure 4 M5! D・

Claims (1)

[Claims] In a vehicle differential device that enables differential gearing between left and right drive wheels using a differential gear, when the vehicle speed exceeds a predetermined value, a differential gear box and a large differential gear are connected in response to the vehicle speed. A differential device for a vehicle, characterized in that a differential limiting torque is achieved between 5 vct,y,=.