JPS6015011Y2 - Deflock device of two-stage reduction type reduction differential device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a differential lock device for a vehicle, particularly a two-stage reduction differential.

As is well known, a differential device is installed on the drive axle of a vehicle to allow the difference in rotational speed between the left and right wheels when the vehicle turns to smooth the turn, but only one wheel of the drive axle has a groove. In the case of a cave-in in mud, etc., due to the action of the differential device, only the wheel on the cave-in side, which has a smaller load torque than the wheel on the opposite side, receives driving force and spins, and the wheel on the opposite side receives no driving force. Since the transmission is not transmitted, the wheels will not be able to escape from the depression and the vehicle will be unable to drive.

In light vehicles such as passenger cars, it is possible to push the vehicle body manually to get the wheels out of the depression, but in large vehicles such as trucks, it is impossible to deal with this problem with human power alone.

For this reason, in large vehicles, in such an emergency, the relative rotation of the left and right axle shafts (axles) connected to the side gears of the differential is locked, so that the driving force is transmitted to both the left and right wheels as one unit, so that the driving force is transmitted from the depressed portion to the left and right wheels. A differential lock device is provided to allow the wheels to escape.

Conventionally, there are various types of differential lock devices for differential gears.

The one shown in FIG. 1 is formed by dividing the end of one axle shaft 1 on the differential device 2 side, and forms an end shaft member 1a spline-fitted to a side gear 3 and a shaft main body 1.
A spline hole 6a is formed in the center of a spider shaft 6, which is spline-fitted to allow free movement in the axial direction and supports the pinion gear 4 in the differential case 5.

When the differential is locked, the end shaft member 1a is moved leftward from the illustrated state to fit the spline of the end shaft member 1a into the spline hole 6a of the spider shaft 6, so that the spider shaft 6 and the axle shaft 1 are Accordingly, the relative rotation of the side gears on both sides, that is, the relative rotation of the left and right axle shafts 1.7 is locked.

However, this configuration in which the axle shaft is divided and splined together for the differential lock device, which is only used in emergencies, has the disadvantage that large torque is constantly applied to the splines of the axle shaft, resulting in poor durability.

Also, as shown in Figure 2, one axle shirt!・1
By fitting the spline 12a formed on the large diameter part of the sleeve 12 which is spline-fitted to the spline 1 and the spline 13a formed on the peripheral wall of the boss portion of the differential case 13 at the time of differential locking, the connection between the one axle shaft 11 and the differential case 13 is There is also one in which the relative rotation is locked, and the relative rotation of the left and right axle shafts 11, 14 is accordingly locked.

Although this can be applied to a type of reduction differential in which the differential case 13 is directly bearing on the axle 1 housing or carrier cover, this is a two-stage reduction type reduction differential in which the rotation of the ring gear is reduced by a planetary gear and transmitted to the differential case. The device is practically difficult to apply.

That is, in this type of reduction differential device, the differential case is housed in a support case that is integrated with the ring gear, and is pivotally supported by the axle housing or carrier cover via the support, so the configuration of the differential lock device described above cannot be applied.・
In order to do this, it is necessary to install a bearing between the differential case and the support case, which rotate relative to each other, extend the peripheral wall of the boss part of the differential case, and then install a sleeve for differential locking between the axle shaft and the structure, which is extremely complicated and complicated. This is because it becomes large.

Also, although it is different from the so-called differential lock mechanism, there is also a structure in which the left and right side gears are free to move in the axial direction relative to the axle shaft, and are formed into latch gears that can be connected to and connected to the pinion gear, driving only the left or right axle shaft. Therefore, for example, by separating the clutch gear of the axle shaft on the side of the sunken wheel from the pinion gear, the driving force can be transmitted only to the other axle shaft, thereby allowing the wheel to escape from the sunken part.

However, in addition to the complexity of this type of structure,
Since the driving force is transmitted only to the axle shaft on one side, a large load is applied to the axle shaft, which poses problems in terms of durability and strength, and also has the disadvantage that good steering stability cannot be obtained.

The present invention was developed in view of these conventional drawbacks, and is applied to a two-stage reduction type reduction gear in which the rotation of a ring gear transmitted by a pinion drive gear is decelerated by a planetary gear and transmitted to a differential gear. To provide a differential lock device with a simple structure, which can smoothly operate and provide a good differential lock function in an emergency without adversely affecting the deceleration differential function of the vehicle.

The present invention will be described in detail below based on illustrated embodiments.

In the figure, a pinion drive gear 21, which is connected to the output shaft of a transmission (not shown) via a propulsion shaft, is supported by a sleeve 24 through tapered bearings 22 and 23.
The sleeve 24 is attached to the front end of the carrier cover 25 with bolts 26.

A carrier cover 25 is attached to the pinion drive gear 21.
External teeth 29a of a ring gear 29 supported on the rear side wall via side bearings 27, 28 mesh with each other, and as the binion drive gear 21 rotates, the ring gear 29 is rotated at a reduced speed.

A sleeve rod 3, which is a constituent member of a differential lock device to be described later, is attached to a bearing cylinder portion 31a of the left side support case 31, which is integrally fixed to the ring gear 29 by bolts 30.
2 is spline-coupled with an adjustment nut 33 for adjusting the preload of the side bearing 27, and is fitted into the adjustment nut 33 so as to be freely movable in the axial direction.

The inner circumferential wall of a cylindrical sun gear 34 is spline-fitted to the outer circumferential wall of the end of the sleeve rod 32 facing the inner space of the support case 31 and is assembled to the carrier cover 25 in a substantially fixed state. A plurality of planetary gears 35 meshing with the teeth 34a formed on the outer peripheral wall and the inner teeth 29b of the ring gear 29 are attached to a shaft 37 fixed to the side wall of the differential case 36 via bearings 38. The planetary gear 35 rotates around the shaft 37 and also revolves around the sun gear 34 at a rotational speed that is lower than the rotational speed of the ring gear 29.

Inside the differential case 36, there are a pair of side gears 39 and 40 which are coaxially supported with the sun gear 34, and four (two in the figure) pinion gears 42 which are rotatably supported by a cross-shaped spider shaft 41 at right angles thereto. The inner ends of axle shafts (not shown), which are connected to the left and right wheels, respectively, are fitted into the pair of side gears 39 and 40 and are spline-coupled.

When the vehicle is running straight, the pinion gear 42 rotates around the spider shaft 41. Therefore, the pair of side gears 39 and 40 rotate in synchronization with the rotation of the differential case 36, and when the vehicle is turning, the pinion gear 42 rotates around the spider shaft 41. A pair of side gears rotates around 3
It is well known that a rotational speed difference of 9.40° is allowed.

Furthermore, a cylindrical right support case 43 that covers the differential case 36 and is fixed to the right side of the ring gear 29 with a bolt 49 is supported on one side wall of the rear part of the carrier cover 25 via a side bearing 28.

Like the side bearing 27, the side bearing 28 is attached to the carrier cover 25 with a preload defined by an adjustment nut 50.

The differential lock device according to the present invention is attached to the speed reduction differential device having such a configuration.

That is, a spline 39a is formed on the outer circumferential wall of a boss portion of the left side gear 39 that protrudes outward from the side wall of the differential case 36, and a spline 44a formed at one end of the inner circumferential wall is fitted into the spline 39a so as to be freely movable in the axial direction. 44, a return spring 45 is fitted between the inner circumferential surface of a flange 44b formed at the outer end of the sleeve 44 and the outer end surface of the side gear 39, and the clutch sleeve 44 is attached to the end surface of the sleeve rod 32. It is strongly encouraged.

Furthermore, radial tooth portions 44c and 36a are formed on the inner end wall of the clutch sleeve 44 and the outer wall portion of the differential case 36 opposing thereto, respectively, which engage with each other as the clutch sleeve 44 moves in the direction shown.

On the other hand, one end of a lever 47 is pivotally supported on the outer peripheral wall of the end of the sleeve rod 32 that protrudes outward from the carrier cover 25 via a pin 46, and the other end of the lever 47 is attached to the outer wall of the carrier cover 25. It is rotatably supported via a pin 48.

The end of the lever 47 is connected to a differential lock operating rod in the driver's cab via a link mechanism (not shown).

In the differential lock device having such a configuration, during normal driving, the lever 47 is in the illustrated position, and the biasing force of the spring 45 causes the sleeve rod 32 and the adjacent clutch sleeve 4 to be closed.
4 is at the left end position where the large-diameter flange surface of the sleeve rod 32 contacts the inner wall of the support case 31, and the teeth 44c of the clutch sleeve 44 and the teeth 36a of the differential case 36 are separated, so the side gear 39 and differential case 36
Relative rotation between the left and right axle shafts and, therefore, the left and right wheels is allowed to function normally.

On the other hand, as mentioned above, in an emergency such as when either the left or right drive wheel sinks into a groove, mud, etc., when the differential lock operation is performed in the driver's cab, the lever 47 is rotated around the pin 48 via a link mechanism (not shown). Swing counterclockwise from the position shown.

Then, the sleeve rod 32 connected to the lever 47 moves to the right in the drawing, and the clutch sleeve 44 that contacts the end surface of the sleeve rod 32 also moves in the axial direction while rotating together with the side gear 39, so that the teeth of the sleeve 44 move. Since the portion 44c and the tooth portion 36a on the side wall of the differential case 36 mesh with each other, the side gear 39 and the differential case 36 are locked so that they cannot rotate relative to each other via the sleeve 44. The wheels become a body and rotate at the same speed.

Here, the clutch sleeve 44 and the sleeve rod 32, which is provided concentrically in series with the clutch sleeve 44, operate smoothly without causing vibration in the axial direction.Since the return spring 45 is also provided concentrically, uneven wear of each member occurs. can be prevented and durability is improved.

Furthermore, if the sleeve rod 32 that is fitted and attached to the inside of the sun gear 34 is originally provided with a differential lock mechanism in a separate part, the part that is integrally formed as the base of the sun gear 34 can be made into a separate part so that it can move freely in the axial direction. Since it is provided in the main body, it can be configured extremely compactly.

As explained above, the differential lock device of the present invention does not require dividing the axle shaft, so it has excellent durability and strength, provides a stable deceleration differential function during normal driving, and is extremely simple and compact. The configuration allows for smooth operation and reliable differential lock function.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a differential lock device in a conventional differential gear, Fig. 2 is a sectional view showing another example of a conventional differential lock device, and Fig. 3 is an embodiment of a differential lock device according to the present invention. FIG. 4 is an enlarged view of the main part of FIG. 3. 21...Pinion drive gear, 25...
...Carrier cover 29...Ring gear, 3
1...Left side support case, 32...
Sleeve rod, 34...Sun gear, 34a...
...spline, 35...planetary gear,
36... Differential case, 36a... Teeth, 39... Side gear, 43... Right side support case, 44... Clutch sleeve,
44a...Spline, 44c...Tooth section, 5'' return spring, 47...Lever.

Claims (1)

[Scope of utility model registration request] A pinion gear that rotates when the engine driving force is transmitted to it.
The ring gear rotates by meshing with the pinion gear, and the inner and outer circumferences of the cylindrical sun gear mesh with the outer teeth and inner teeth of the ring gear, respectively, and the ring gear rotates on its own axis. A planetary gear that revolves with the
A differential case that pivotally supports the planetary gear and rotates as the planetary gear revolves, a support case that covers the outside of the differential case and is fixed to the ring gear, and a carrier cover and housing that rotatably enclose each of these components. In the two-stage reduction type reduction differential device configured, the differential case and a side gear rotatably supported by the differential case and connected to an inner end of an axle shaft on a side closer to the sun gear are made non-rotatable relative to each other. A latch sleeve that can be freely engaged or disconnected is spline-engaged with a boss portion protruding to the outside of the differential case of the side gear so as to be freely movable in the axial direction, and fitted into the axle shaft on the side gear connection side. a return spring that is provided with teeth that engage when the differential is locked, and that normally biases the clutch sleeve in a direction to separate it from the teeth of the differential case;
a sleeve rod whose one end surface abuts the clutch sleeve biased by the return spring, which is fitted inside the sun gear and is attached to the carrier cover so as to be freely movable only in the axial direction; and a carrier cover of the sleeve rod; It is composed of a link mechanism that engages with the end that protrudes outside the housing and moves the clutch sleeve in the axial direction via the sleeve rod.During normal driving, the differential case and side gear are disengaged, and when the differential lock is operated. A differential lock device for a two-stage reduction type reduction differential device, characterized in that a switching device is provided for switching by moving a clutch sleeve in the axial direction to engage the two.