JPS6023212Y2 - Transfer case for permanent four-wheel drive vehicles - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transfer case for a permanent four-wheel drive vehicle that can stop differential operation when driving on rough terrain, has a simple structure, and can be made compact.

As a four-wheel drive device with a conventional differential mechanism, for example,
Utility Model Publication No. 47-1694 and Utility Model Number 51-2586
There is something written in the Hajime gazette.

The former includes a front-wheel output shaft, a rear-wheel output shaft disposed parallel to the front-wheel output shaft, and an input shaft disposed coaxially with the rear-wheel output shaft.

A differential mechanism is arranged from the input shaft to the output shaft on the rear wheel side, one bevel gear (side gear) of the differential mechanism is loosely fitted onto the input shaft, and from the one bevel gear to the output shaft on the front wheel side. It has a configuration that transmits power.

Further, the latter device has a differential mechanism attached across two driven shafts arranged on the same axis, and has a configuration in which power is input from a differential case of the differential mechanism.

However, in the invention of Utility Model Publication No. 47-1695, the output from the input shaft 2 to the second output shaft 7 is performed by a bevel gear 12 loosely fitted on the input shaft 2, and the axial direction of the bevel gear 12 is On the input side (left side), a collar 14, a sleeve 15, and a bearing (the two on the left that support the input shaft 2) are further arranged in a row, so the overall device size is reduced by the collar 14, sleeve 15, and bearing. The axial length must become longer.

In addition, in the invention of Utility Model Publication No. 47-1694, the input shaft 2 is supported by a bearing supported by the casing 1, and a transmission gear is mounted on the outer periphery of a bevel gear 12 loosely fitted onto the input shaft 2. 13 to output to the second output shaft 7.

Therefore, the transmission gear 13 is supported by a loosely fitting part between the bevel gear 12 and the input shaft 2, and in order to ensure strength and to secure a support part sufficient to prevent falling, it is necessary to support the transmission gear 13 in the axial direction. I have no choice but to make it longer.

In addition, the input shaft 2 is in a cantilevered state with respect to the position (load point) where the transmission gear 13 is disposed, resulting in a large bending moment, which may generate vibrations and noise due to changes in the meshing of the gears.

Furthermore, since the bevel gear 12 is displaced in the axial direction due to the thrust force generated by the small bevel gear 10 and the bevel gear 12, the meshing state of the transmission gear 13 may change or There is also a problem in durability since a load is applied to the bearing.

In addition, since the differential mechanism and the lock mechanism are connected on the same axis and both ends are supported by bearing members,
Since a large number of parts are supported by two pairs of bearing members, it is easy to be affected by accuracy errors of each part.

In addition, Utility Model Publication No. 51-25860 has a configuration in which torque is input from the differential case and distributed to two driven shafts that are coaxial, so the front driven shaft and rear driven wheels are arranged in parallel. Therefore, the differential mechanism is located below the input shaft, and the differential mechanism is close to the ground.

As a four-wheel drive vehicle, it is important to have a sufficiently high ground clearance at the bottom of the vehicle when driving off-road, so having the differential mechanism at the bottom is a fatal flaw.

The present invention was developed in view of the above, and aims to simplify the configuration of the differential mechanism, minimize the influence of accuracy errors in component parts, and place the differential mechanism as high as possible from the ground. In order to enable
The input shaft and the rear export force shaft are arranged on the same axis, and the pinion shaft that makes up the differential mechanism is integrated with the input shaft, and the pinion shaft does not directly engage with the differential case. A transfer case for a full-time four-wheel drive vehicle, which is integrated with the differential case and connects the differential case to the front wheel drive shaft, and another side wheel is fixed to the outer periphery of the rear wheel drive shaft, and bearings support both axial ends of the differential case. This is what we provide.

Although the purpose and structure of the present invention have been briefly explained above,
An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Torque from the transmission is transmitted to the input shaft 1 and then to the pinion shaft 2 via the spline 1a.

The movement of the pinion shaft 2 is equally divided and transmitted from the pinion mate 3 to a pair of side gears 4.5.

The rotational torque of one side gear 4 is transmitted to a first axle 6 that transmits it to the rear wheels.

On the other hand, the torque transmitted to the side gear 5 is transmitted to the differential case 7 via the spline 5a.

A sprocket 8 is fixed on the outer periphery of the middle part of the differential case 7 with bolts 9, and the other sprocket 1
0 by a chain (not shown).

Therefore, the rotational torque of differential case 7 is -8
, 10 (via a route perpendicular to the input shaft 1 and the second axle 11), the signal is transmitted to the second axle 11 (front wheel drive shaft 11), and from there to the front wheels.

Reference numeral 20 is a bearing that supports both ends of the differential case 7;
The bearing 20 itself is a differential mechanism (consisting of pinion mate 2, pinion gear 3, side gear 4.5, differential case 7, etc.)
It is supported by a casing 21 that holds the whole.

Further, a cylinder 12a is formed in the cover 12, and a piston 13 is fitted into the cylinder 12a.

The piston 13 is fixed to the sleeve 14 by a retaining ring 15 in the axial direction.

A spline 14a is formed on the inner periphery of the sleeve 14, and is fitted into a spline shaft 7b formed on an extension 7a of the differential case 7.

The piston 13 is forced to move leftward by a spring 16, and a negative pressure introduction hole 12b is formed in the cylinder 12a.

In the above configuration, the illustrated state is a state in which the differential is functioning, and the rotational torque applied to the shaft 1 is applied to the pinion shaft 2, pinion mate 3, pair of side gears 4, and After the torque is distributed by 5,
A predetermined torque is applied to the axle 6°11 for the front and rear wheels.

However, when the front wheels or rear wheels slip while driving on rough terrain, the axle 6 and the differential case 7 are mechanically engaged to stop the differential.

That is, when negative pressure from an appropriate negative pressure source, for example, negative pressure from a manifold, is introduced into the negative pressure introduction hole 12b of the cylinder 12a, the piston 13 is moved to the right against the elastic force of the spring 16. It will be done.

Due to this movement of the piston 13, the sleeve 14 also moves to the right, and its spline 14a couples with the spline 6a formed on the first axle 6, and as a result, the sleeve 14
Mechanical integral engagement between the first axle 6 and the differential case 7 is achieved via the first axle 6 and the differential case 7.

Due to the mechanical coupling, the rotational torque applied to the shaft 1 is equally applied to the first and second axles 6 and 11 via the differential case 7, and the differentials are stopped by driving at the same rotation speed. .

In addition, a bearing 20 (a casing 2 that holds the entire differential mechanism)
1) supports both ends of the differential case, so by arranging bearings in series in the axial direction (input side) of the differential mechanism, as proposed in Utility Model Publication No. 47-1694, There is no risk of increase in axial length.

Torque is transmitted from the input shaft 1 to the front wheel drive shaft 11 via a sprocket 8 on the outer periphery of the central large-diameter portion (middle portion) of the differential case 7 and a chain (not shown) (the chain and the like are referred to as power transmission means). Moreover, since the power transmission means such as a chain is located on a straight line orthogonal to the input shaft 1 and the front wheel drive shaft 11, the power transmission means is located on a straight line orthogonal to the input shaft 1 and the front wheel drive shaft 11, so that the power transmission means is located on a straight line orthogonal to the input shaft 1 and the front wheel drive shaft 11. , an increase in the axial length due to sequential arrangement of members such as the power transmission means can be avoided.

That is, in the above-mentioned Japanese Utility Model Publication No. 47-1694, torque is output directly from the outer periphery of the bevel gear 12 that constitutes the differential mechanism (the torque transmission route is directly from the outer periphery of the bevel gear 12 without going through the differential case). 2), it is impossible to support the bevel gear 12 itself with a bearing.

Therefore, it is necessary to arrange the bevel gear 12 and the bearing (the left bearing) in series in the axial direction, so that the bevel gear 12 is not supported by the bearing.

In contrast, in the present invention, the side gear 5 is connected to the inner circumference of the input side end of the differential case 7 via the spline 5a on its outer circumference (the side gear 5 is directly connected to the front wheel drive shaft 11). The outer periphery of the side gear 5 (via the outer periphery of the small diameter part of the differential case)
Bearing support is possible.

Therefore, there is no need to position the bearing closer to the axial input side than the side gear 5, and the axial length can be shortened.

Torque is transmitted from the input shaft 1 to the front wheel drive shaft 11 using a sprocket 8 provided on the outer periphery of the intermediate portion of the differential case 7 whose both ends are supported by bearings, a chain (not shown), etc. (the chain and the like are referred to as power transmission means). It is done through

Therefore, since the side gear 5 loosely fitted to the input shaft 1 only needs to have a torque transmission function between the input shaft 1 and the differential case 7 (in other words, it only needs to be integrated with the differential case 7), the illustrated As in the case of the bevel gear 12 with the support part of the transmission gear 13 in Japanese Utility Model Publication No. 47-1694, it is not necessary to use spline engagement on the bearing support part, and the length in the axial direction is not necessarily required. This is essentially different from the case where the axial length is required.

Furthermore, the torque transmission to the front wheel drive shaft 11 is carried out by the differential case 7.
The load is applied via a sprocket provided on the outer periphery of the middle part of the differential case 7, and the middle part becomes the load point.However, since the differential case 7 is supported at both ends by bearings (that is, supported on both sides), it is resistant to the bending moment. It is also strong and can suppress vibration and noise caused by changes in gear meshing.

In addition, in the present invention, since the side gear 5 is built into the differential case 7, the thrust force due to meshing with the pinion mate 3 is received within the differential case, so it does not affect the bearings that support the differential case 7.

As a result, it becomes possible to shorten the axial length of the differential mechanism.

In addition, since the differential case 7 is directly supported by bearing members at both ends, it is affected by accuracy errors in the parts that make up the differential mechanism (for example, rattling due to gaps in the meshing parts of each gear, vibration and noise). occurrence) is low.

In addition, since the differential mechanism is located above (higher than the ground) and the front wheel drive shaft 11 is located below, the ground clearance of the bottom of the vehicle can be maintained high, providing excellent characteristics as a four-wheel drive vehicle. demonstrate.

In other words, the differential mechanism has a large diameter and a large axial length, so if it is located downward, there is a high risk of contact with the ground on uneven ground, whereas in the present application, the front wheel drive shaft 11 is There is no such fear since it is only located below.

In addition, conventional part-time (continuously switching) four-wheel drive vehicles have a single gear and an on/off switching clutch in the position where the differential mechanism of the present invention is installed; Since the drive mechanism is compact, it is possible to replace the gears and clutch parts of a part-time model with minimal modification or design changes.

However, it should be understood that the above description of the embodiments does not limit the scope of the present invention, and that various changes may be made within the scope of the claims for utility model registration.

[Brief explanation of the drawing]

The accompanying drawings are cross-sectional views showing one embodiment of the present invention. Explanation of symbols: 1...Axis, 1a...Spline, 2...Pinion shaft, 3...
...Pinion mate, 4,5...Side gear, 6...1st axle, 6a...Spline, 7...Differential case, 7a... ...Differential case extension, 8...Sprocket, 9...
...Bolt, 10...Sprocket, 11
...Second axle, 12...Cover, 1
2a...Cylinder, 12b...Negative pressure introduction hole, 13...Piston, 14...
Sleeve, 14a...Spline, 15...
... Retaining ring, 16... Spring.

Claims (1)

[Claim for Utility Model Registration] Differential rotational torque of the differential mechanism based on the input torque from the input shaft is transmitted to the front wheel drive shaft via the rear wheel drive shaft and a differential case supported by bearings attached to the casing. , a transfer case for a four-wheel drive vehicle in which the two drive shafts are locked by a locking mechanism when the differential operation is stopped, the rear drive shaft being disposed coaxially with the input shaft; The front wheel drive shaft is arranged parallel to the input shaft, the differential mechanism is located from the outer periphery of the input shaft to the outer periphery of the rear wheel drive shaft, and both ends are supported by bearings, and an intermediate portion is arranged parallel to the front wheel drive shaft. a differential case directly connected to a power transmission means perpendicular to the differential case; a plurality of pinion shafts located inside the differential case and fixed to the outer periphery of the input shaft without directly engaging the differential case; and a plurality of pinion shafts rotatably attached to the pinion shaft. one side gear that is rotatably supported on the input shaft while meshing with the pinion mate and integrally connected to the input side of the differential case; and a side gear that meshes with the pinion mate and is rotatably supported on the input shaft; A transfer case for a permanent four-wheel drive vehicle, characterized in that it consists of a side gear and another side gear integrated into the transfer case.