JPH023069B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a freewheel type axle differential used in vehicles and the like, and particularly relates to a freewheel type axle differential that can switch and control power transmission to an axle.

[Conventional technology]

A so-called differential gear system using a differential gear mechanism has been used for many years as an axle differential system for vehicles, but according to this system, if one wheel loses its ground contact force, the other wheels The disadvantage is that the driving force is lost. Therefore, recently, a freewheel type axle differential device has been proposed, which uses a freewheel mechanism to drive the left and right wheels independently and allows each wheel to rotate freely, allowing differential movement between the left and right axles. This type of prior art is known, for example, as described in US Pat. No. 3,124,972.

[Problems to be solved by the invention]

However, in the conventionally known freewheel type axle differential device, the left and right axles cannot be freely rotated at the same time, so the axle side and the drive system thereto are always connected. Therefore, when this is applied, for example, to the axle side after the transfer mechanism in a vehicle that switches between two-wheel drive and four-wheel drive via a transfer mechanism, when the two-wheel drive mode is running, In addition, the drive system after the transfer is reversely driven by non-driven wheels, which is disadvantageous in that it not only increases running resistance but also generates noise. The present invention has been made to solve the above-mentioned disadvantages, and can be applied to vehicles that switch between two-wheel drive and four-wheel drive to reduce running resistance during two-wheel drive and enable quiet running. An object of the present invention is to provide a freewheel type axle differential.

[Means to solve the problem]

For this purpose, the present invention transmits power by rotating the retainer divided into left and right parts in the normal and reverse directions, and restricts the relative rotation of one of the retainers beyond the neutral position of the other, thereby making a difference between the left and right axles. In a freewheel type axle differential device that allows movement, a neutral holding member is provided to elastically hold the left and right retainers at neutral positions, and a neutral holding member is provided between these retainers and the axle side to allow differential rotation of the axle. and a friction clutch that receives a switching operation between a predetermined pressure contact against the elastic holding force of the neutral holding member and its release.

【Example】

The present invention will be described below based on an embodiment shown in the drawings. FIG. 1 shows a drive system of a four-wheel drive vehicle to which the present invention is applied, in which reference numeral 1 is an engine, 2 is a transmission to which power is transmitted via a clutch device (not shown), and an axle 4 for front wheels 3, 3 is shown. , 4 are directly connected to and driven by the transmission 2. Furthermore, for the axles 6a and 6b of the rear wheels 5a and 5b, a freewheel type axle differential is connected to the drive system consisting of the transmission 7, the propeller shaft 8, the drive pinion shaft 9, etc. Power is transmitted through the device 10. In the figure, reference numeral U indicates a universal joint, and reference numeral 11 indicates a housing that accommodates the above-mentioned differential device, and as shown in FIG. It is rotatably supported. To explain the freewheel type axle differential device 10 in detail here, the casing 14 is equipped with a crown gear 13 that meshes with the drive pinion 12.
The angular bearing 15 is attached to the housing 11 above.
are supported through the left and right axles 6a, 6b.
The inner surface of the casing 14 is formed into an uneven shape with a corrugated cross section as shown in FIG. 3, and forms the outer ring of the freewheel. On the other hand, the inner ring 18 of the freewheel, which forms the moving chamber 17 of the roller 16 between the uneven inner surface of the casing 14, is formed in a cylindrical shape, and the left and right axles 6a, 6b are connected to each other at the opposite ends of the axles 6a, 6b. It is spline connected to the axle and integrated with the axle. In this way, the casing 14, which is the outer ring of the freewheel, and its inner ring 18
One roller 16 is arranged in each half-moon-shaped roller movement chamber 17 formed between the
These are restrained from moving in the axial direction by a roller retainer 19, and their positions are maintained in accordance with the pitch of the moving chamber 17 in the rolling direction.
When the roller retainer 19 is in the positional relationship with respect to the casing 14 as shown in FIG.
9 rotates in the forward or reverse direction, each roller 16 moves toward the casing 14 at the end of the moving chamber 17.
and the inner ring 18 are connected to each other. The roller retainer 19 described above has the left and right inner rings 1
8 and 18, respectively, and their opposing end surfaces are engaged with claws in a dog clutch shape with a gap that allows a predetermined relative rotation, and one of them engages with the casing 14 by a claw. When the roller retainer 19 is in the engaged position where the casing 14 and the inner ring 18 are coupled together through the rollers 16, the other roller retainer 19 is allowed to rotate to the neutral position and further rotation is restricted. It's becoming like that. The structure of the freewheel described above is substantially the same as that of the conventional one, but according to the present invention, there is provided a neutral holding member 20 that resiliently supports the roller retainer 19 in a neutral position, and a neutral holding member 20 that resiliently supports the roller retainer 19 in a neutral position.
A friction clutch 21 is provided which rotates the roller retainer 19 against zero. As shown in FIG. 4, this neutral holding member 20 is made of spring steel formed into a ring shape, the abutting ends of which are bent diametrically outward to form two engaging pieces 20a at a predetermined interval. ，
20b, the ring-shaped portion of which is in close contact with the inner circumferential surface of the roller retainer 19. Further, the engaging pieces 20a and 20b are connected to the roller retainer 1.
An engagement groove 23 is formed on the inner surface of the casing 14 and protrudes outward from a window hole 22 bored at one location on the circumference of the casing 14.
In this state, the roller retainer 19 is held in a neutral position.
Moreover, if the elastic force of the neutral holding member 20 in the circumferential direction is resisted, the roller retainer 19 rotates normally.
It is held so that it can rotate in the reverse direction and take the engagement position. Such a neutral holding member 20 has left and right roller retainers 19,
A pair is provided corresponding to No. 19. Next, as shown in FIG. 5, the friction clutch 21 engages with the outer end of the roller retainer 19 via a clutch plate 24 which is loosely fitted onto the axle 6b and can be pressed against the end surface of the inner ring 18. Such a clutch plate 24 is similarly arranged on the axle 6a side.
In order to press the clutch plate 24 against the end surface of the inner ring 18, a pressure ring 25 is loosely fitted to the axle 6b and is screw-fitted to the housing 11 so as to be freely movable in the axial direction of the axle 6b. The pressure ring 25 is connected via bearings arranged between the end face and the clutch plate 24 on the axle 6b side, between the left and right inner rings 18, 18, and further between the clutch plate 24 on the axle 6a side and the side wall of the casing 14. It is constructed so that the pressure force accompanying the advance is applied to the left and right clutch plates 24, 24. The left and right end surfaces of the bearings are in contact with each other, one at the outer ring and the other at the inner ring, allowing the left and right members with the bearing in between to freely rotate relative to each other. Here, the outer end of the pressure ring 25 faces the outside of the housing 11 via an O-ring 26, and a lever 27 for advancing and retracting the pressure ring 25 is attached thereto. The friction clutch 21 that is
By rotating clockwise in the figure, the pressure ring 25 advances and the left and right clutch plates 24, 24
is pressed against the inner rings 18, 18, and the pressing force is released by counterclockwise rotation of the lever 27. The frictional engagement force due to the pressure contact of the clutch plate 24 is large enough to resist the elastic force of the neutral holding member 20, and one of the left and right roller retainers 19, 19 is regulated by the other to maintain the neutral position. When maintained, the size is set so that slippage occurs between the inner ring 18 and the axle 6a or 6b to rotate freely. Further, the lever 27 is connected through a long hole to an operating rod 29 of a negative pressure actuator 28 that is perpendicular to the lever 27, and the lever 27 is rotated clockwise and counterclockwise depending on whether the actuator 28 is activated or deactivated. It is connected so that The operating negative pressure passage 30 to the negative pressure actuator 28 includes:
An electromagnetic on-off valve 32 is provided which is energized to open the passage 29 when a switch 31 is turned on in conjunction with the switching operation from two-wheel drive to four-wheel drive. In the above configuration, when the switch 31 is turned on, the electromagnetic on-off valve 32 opens the passage 30, and the intake negative pressure for operation reaches the negative pressure actuator 28 to pull the operating rod 29. As a result, the lever 27 rotates clockwise in FIG.
9 and 19 are integrated on the left and right axles 6a and 6b, respectively. On the other hand, with the switching operation to four-wheel drive, the power of the engine 1 is transmitted to the casing 14 via the transmission 2, the transfer transmission 7, the propeller shaft 8, and the drive pinion shaft 9. The left and right axles 6a, which have stopped rotating,
6b, the left and right roller retainers 19, 19 integrated with the axles 6a, 6b are rotated against the casing 14 against the elastic force of the neutral holding member 20. The engagement position shown in FIG. 7 is reached by relative rotation in the direction shown in FIG. Therefore, from now on, the roller 16, the inner ring 18,
The rotational power of the casing 14 is transmitted to the axles 6a and 6b via the axles 18, and the vehicle travels in four-wheel drive. Such four-wheel drive running is not limited to forward running of the vehicle, but also applies to backward running, and in this case, the roller retainer 19 assumes the engagement position shown in FIG. 8. When traveling downhill in the above-mentioned four-wheel drive state, the left and right rear wheels 5a, 5b try to rotate at a higher speed than the drive rotation speed due to gravity acceleration, but they are integrated with the axles 6a, 6b. The locked roller retainers 19, 19 rotate relative to the casing 14 in the normal rotation direction and reach the locking position.
As shown in the figure, the rotation of the axles 6a and 6b is
8. It is regulated by the casing 14 via the rollers 16, and engine braking is activated. In addition, in this four-wheel drive driving, when making a right turn, for example, the left rear wheel 5a passes through a longer path than the right rear wheel 5b, so the rotational speed increases slightly, but along with this, the left axle The roller retainer 19 on the right axle 6a side rotates in the normal rotation direction from the engagement position, and when it reaches the neutral position, its rotation is regulated by the roller retainer 19 on the right axle 6b side, which assumes the locking position. never get into a state. When the roller retainer 19 is in the neutral position, the inner ring 18 is free to rotate relative to the casing 14, and the frictional engagement force with the clutch plate 24 is set to a relatively small value that allows rotation of the inner ring 18. Therefore, the left axle 6a can freely rotate following the left rear wheel 5a, and the vehicle can turn smoothly. It goes without saying that the same applies when turning left. Next, the drive system consisting of the propeller shaft 8 drive pinion shaft 9, casing 14, etc. after the transfer station 7 becomes inoperable.
To explain wheel drive driving, when the switch 31 is opened in conjunction with the switching operation to two-wheel drive, the electromagnetic on-off valve 32 closes the passage 30 and deactivates the negative pressure actuator 28. The lever 27 is rotated counterclockwise in FIG. 6 via the lever 27. As a result, the friction clutch 21 releases the pressing force of the clutch plates 24, 24, and the left and right roller retainers 19, 19, together with the clutch plates 24, 24, are separated from the inner races 18, 18 and, in turn, from the axles 6a, 6b, and rotate. It becomes movable, and the neutral position is maintained by the elastic holding force of the neutral holding member 20. Therefore, the left and right axles 6a, 6b
is rotatable, and the rotation of the inner rings 18, 18 of the freewheel is no longer transmitted to the casing 14 side, so the drive pinion shaft 9 and propeller shaft 8 are reversely driven by the rotation of the non-driven rear wheel axles 6a, 6b. Nothing will happen at all. the result,
Running resistance during two-wheel drive running is reduced and noise generation is also prevented.

【Effect of the invention】

As explained above, according to the present invention, the retainer can be rotated in both forward and reverse directions with respect to the casing against the neutral holding member by pressing the friction clutch, so that power transmission for forward and backward movement of the vehicle is ensured. Of course, engine braking can also be applied. In addition, even when the axle is driven in this way, the left and right retainers can maintain a neutral position by being regulated by the other, and in this state the axle can freely rotate against the pressure contact force of the friction clutch. This allows for smooth turning. In particular, when the friction clutch is released from pressure, the left and right retainers are held in the neutral position by the elastic force of the neutral holding member, so the left and right axles can freely rotate independently of the drive system. can. Therefore, in a vehicle that switches between two-wheel drive and four-wheel drive via a transfer mechanism, for example, by applying this to the axle side after the transfer mechanism, the above-mentioned The drive system after the transfer station is no longer reversely driven by non-driven wheels, reducing running resistance during two-wheel drive driving, and also reducing noise caused by reverse drive of the drive system. Effects such as prevention can be obtained.

[Brief explanation of drawings]

Fig. 1 is a drive system diagram of a vehicle to which an embodiment of the present invention is applied, Fig. 2 is a sectional view of the main parts, and Fig. 3 is a diagram of the
A sectional view along the - line in the figure, Figure 4 is the same -
5 is a sectional view taken along the same line, FIG. 6 is a diagram illustrating the configuration of the operation system of the friction clutch, and FIGS. 7 and 8 are diagrams illustrating the operation of the roller retainer. 1...Engine, 2...Mission, 3...Front wheel, 4...Axle, 5a, 5b...Rear wheel, 6a, 6
b... Axle, 7... Transfer transmission, 8
... propeller shaft, 9 ... drive pinion shaft, 10 ... freewheel type axle differential, 1
1...Housing, 12...Drive pinion,
13...Crown gear, 14...Casing, 1
5... Anguilla bearing, 16... Roller,
17...Moving chamber, 18...Inner ring, 19...Roller retainer, 20...Neutral holding member, 21
... Friction clutch, 22 ... Window hole, 23 ... Engagement groove, 24 ... Clutch plate, 25 ... Pressure ring, 26 ... O-ring, 27 ... Lever, 28
... Negative pressure actuator, 29 ... Operation rod,
30... passage, 31... switch, 32... electromagnetic on-off valve.

Claims (1)

[Claims] 1. A freewheel is provided between the rotationally driven casing and the axle side, which engages the two by rotating the retainer in both forward and reverse directions, and in the middle of the rotation, the axle is in a neutral position where the axle is free to rotate. In the above-mentioned freewheel type axle differential device, the retainer is configured to be divided corresponding to the left and right axles, and is associated so that when one of them is in the engaged position, the other can take the neutral position, thereby allowing differential movement between the left and right axles. A neutral holding member is provided to elastically hold the left and right retainers at neutral positions, and a neutral holding member is provided between these retainers and the left and right axles to allow differential rotation of the axles and to resist the elastic force of the neutral holding members. 1. A freewheel type axle differential device comprising a friction clutch that receives a switching operation between predetermined pressure contact and release thereof.