JPS6345378Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a front wheel drive switching device for a four-wheel drive vehicle.

Recently, four-wheel drive vehicles, especially light vehicles such as work trucks, have become popular. A four-wheel drive vehicle is a vehicle that can drive the front wheels in addition to the conventional rear-wheel drive vehicle, so it has strong running power and is convenient for driving freely on uneven roads (construction sites, farm roads, farmland, etc.) It has a certain quality. Normally, when driving on a level surface such as a paved road, only rear wheel drive is used, but conventionally, even when the rear wheels are in drive mode, the front wheel drive shafts are rotated at the same time. Even during wheel drive, the front wheel drive shaft and the front wheels are usually always linked. This causes problems such as not only poor fuel efficiency when driving the rear wheels, but also a heavy steering wheel, a shallow steering angle, and an increase in noise and vibration. Therefore, some vehicles generally use a freehub wheel mechanism, which allows the front wheels to be freely connected to the front wheel drive shaft, so that when the rear wheels are driven, the rotation of the front wheels is not transmitted to the front wheel drive shaft. However, when switching from four-wheel drive to only rear-wheel drive, this freehub wheel mechanism requires the driver to get out of the vehicle and engage/disengage the hub using the front wheel portion each time. Therefore, switching from four-wheel drive to rear-wheel drive was inconvenient and extremely difficult to use.

Furthermore, in Japanese Utility Model Application No. 60-132920, a cylindrical control tube is rotatably fitted between the spindle and the drive shaft, and the control tube is rotated by operating a lever near the driver's seat. At the same time, an axially movable operating member is moved in the axial direction by an inclined cam mechanism formed at the other end of the control tube, and the movement of the operating member is transmitted to the clutch member. By engaging spline teeth on the member with the spring shaft of the freewheel hub body, the drive shaft and the freewheel hub body are connected, and by performing the opposite operation to the above, the two are disconnected. The configuration is disclosed. However, with such means, the operating force of the operating lever must be converted into rotation of the control tube, so
It has the disadvantages of large energy loss, complicated structure, and high cost.

Therefore, the present invention eliminates the problems of the front wheel drive shaft switching device in conventional four-wheel drive vehicles and provides a mechanism for freeing the front wheel drive shaft via a lever installed near the driver's seat. This is a system that provides a
By moving the front wheel drive shaft itself in the axial direction, the front wheel drive shaft is configured to be able to engage and disengage from the wheel portion, thereby breaking the linkage between the front wheel drive shaft and the wheel, thereby simplifying the configuration and reducing energy loss. The purpose of this invention is to provide a front wheel drive shaft switching device with a small number of units.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the main parts of the front wheel drive mechanism, where 1 is a differential gear, 2 is a first front wheel drive shaft, 3 and 3a are a pair of cylinders arranged near the wheel 4, 5 is a front wheel mounting part, 6 is a steering knuckle, 7 is a strut, and 8 is a front tire. At one end of the first front wheel drive shaft 2 on the differential gear 1 side, there is a convex joint 16 as shown in FIG.
A first universal joint 12a is formed of a concave joint 14 that is spline-engaged with and expands and contracts in the vehicle width direction.
A second universal joint 12 is formed at one end on the vehicle width side of the vehicle, and includes a similar convex joint 13 and a concave joint 10 that engages with the convex joint 13 and is expandable and retractable in the vehicle width direction. Said first universal joint 12
A shaft 17 that engages with the differential gear 1 is fixed to the concave joint 14 constituting the second
A second front wheel drive shaft 11 is fixed to a concave joint 10 constituting a universal joint 12. That is, in the case of the present invention, the front wheel drive shaft is the first front wheel drive shaft 2.
and a second front wheel drive shaft 11, and the first front wheel drive shaft 2 and the second front wheel drive shaft 11 are connected to the vehicle by a first universal joint 12a and a second universal joint 12. It is connected so that it can expand and contract in the width direction.
An external gear 9 is fixed to an end portion of the second front wheel drive shaft 11 in the vehicle width direction. Further, 18 is a cover that covers the first universal joint 12a.

Next, using FIG. 3, the second front wheel drive shaft 11
The connection structure between the wheel 4 and the wheel 4 will be explained.

In the figure, reference numeral 5 denotes a front wheel mounting portion that rotatably supports the second front wheel drive shaft 11. The front wheel mounting portion 5 is pivotally supported by a steering knuckle 5 and connected to the wheel 4 with a bolt 19 and a nut 20. ing. 2
1 is a bearing. Further, a cap 23 equipped with an internal gear 22 that engages and disengages from the external gear 9 fixed to the end of the second front wheel drive shaft 11 in the vehicle width direction is integrally attached to the front wheel mounting portion 5 using bolts 24. It is fixed to. 22a is a toothless part, and the external gear 9
This is the part where you can idle. Further, the pair of cylinders 3 and 3a described above are arranged around the second front wheel drive shaft 11 between the front wheel mounting portion 5 and the second concave joint 10. The tubes 3 and 3a mentioned above each have a sliding engagement portion cut diagonally with respect to the axis, and are arranged so that the cut surfaces face each other, and the tube 3 on the wheel 4 side is It is fixed to the front wheel mounting portion 5 via a flange 25, and this protrusion 26 is provided with a wire connection portion 27. A wire 28 is connected to this wire connecting portion 27 . As shown in FIG. 6, the wire 28 is connected to a switching lever 30 at an operating section where a shift lever 29 is swingably mounted near the driver's seat. The switching lever 30 is attached to a bracket 32 fixed to an operation plate 31.
is rotatably supported via a shaft 32a.
A hook 33 is pivotably supported by a lever base 35 via a shaft 34, one end of which extends into the switching lever 30 and is pivotally connected to a locking rod 36.
The locking rod 36 projects from the tip of the grip 37 along the axis of the switching lever 30, pulls the hook 33 with a spring 38, and applies a counterclockwise rotational force. Nao 39
Reference numeral 40 is a lock portion to which the hook 33 is engaged, and 40 is a pulley that wraps around the wire 28 and changes the pulling direction of the wire 28.

Next, using FIG. 4 to explain the connection structure between the first front wheel drive shaft 2 and the differential gear 1, one end of the first front wheel drive shaft 2 on the differential gear 1 side has a A convex joint 16 is formed, and the shaft 17 protruding from the differential gear 1 is provided with a concave joint 14 that is spline engaged with the convex joint 16 and allows the convex joint 16 to move in the vehicle width direction. A first universal joint 12a is formed. A stopper 42 is provided on the first front wheel drive shaft 2, and a spring 43 is elastically mounted between the stopper 42 and the concave joint 14. The spring 43 is biased with a force that constantly presses the first front wheel drive shaft 2 in the vehicle width direction. 44 is a retaining ring for the convex joint 16, which is fixed to the inner wall of the concave joint 14.

To explain the operation of the above embodiment, first, when traveling in four-wheel drive, the switching lever 30 is set up as shown in FIG. 6, and the wire 28 is loosened. Then, as shown in FIG. 2, the cylinders 3 and 3a come into contact with each other at their obliquely cut ends to form a complementary body, and the external gear 9 connects to the cap 23.
Enter the inside of the cap 2 as shown in Figure 3.
It meshes with an internal gear 22 formed at 3. This is because, as shown in FIG. 4, under normal conditions, the first front wheel drive shaft 2 is pressed in the vehicle width direction by the spring 43, so the second front wheel drive shaft is pressed in the vehicle width direction. Depends on what is being done. Therefore, when the first front wheel drive shaft 2 rotates, the wheels 4 also rotate, and the vehicle runs in a four-wheel drive state.

On the other hand, to switch from four-wheel drive to rear-wheel drive, when the switching lever 30 is pulled down and the wire 28 is pulled, the cylinder 3a is rotated by the protrusion 26, and as shown in FIG. The sliding contact and engagement portions that are cut are separated so that they face each other at their sharp points. Then, the cylinder 3a pushes the concave joint 10 constituting the second universal joint 12 toward the differential gear 1, and the convex joint 13 of the first front wheel drive shaft 2 is pushed by the concave joint 10, and the first front wheel The convex joint 16 on the other side of the drive shaft 2 resists the biasing force of the spring 43, and the second front wheel drive shaft 11, which is fixed to the concave joint 10 of the first universal joint 12a, moves toward the differential gear 1 as a whole. As the second front wheel drive shaft 11 moves, the external gear 9 fixed to the end of the second front wheel drive shaft 11 in the vehicle width direction comes off the internal gear 22 of the cap 23 and becomes toothless.
Enter a. When the external gear 9 and the internal toothed portion 22a are disengaged, the wheel 4 and the second front wheel drive shaft 11 become free, and even if the first front wheel drive shaft 2 rotates, the external gear 9 does not move. The toothless portion 22a of the cap 23
It just stops spinning.

When switching to four-wheel drive again, the switching lever 30 is raised as shown in FIG. 6, and the wire 28 is loosened, so that the first Moves the front wheel drive shaft 2 in the vehicle width direction, and uses that force to move the cylinders 3, 3a
The wheel 4 is rotationally driven by returning the external gear 9 to the state shown in FIG. 2 and meshing the external gear 9 with the internal gear 22 of the cap 23 again. The switching lever 30 is operated by grasping the grip 37 with the hand, and when the locking rod 36 is pressed with the finger, the hook 33 and the locking portion 39 are disengaged, and the locking rod 36 is pushed down with the finger. When the push is stopped, the hook 33 engages above or below the lock portion 39 by the force of the spring 38, thereby locking the switching lever 30. When the switching lever 30 is folded down, it is rear wheel drive (two wheel drive), and when it is upright, it is four wheel drive. However, the relationship between the switching lever 30 and two-wheel or four-wheel drive is not limited to the above, and may be of a type that functions in the opposite manner to the above. That is, the switching lever 30 may be folded down for four-wheel drive, and upright for two-wheel drive.

According to the present invention described in detail above, switching between four-wheel drive and two-wheel drive can be performed only by operating a switching lever installed near the driver's seat, and when operating, the first and second front wheel drive axles can be switched between four-wheel drive and two-wheel drive. moves in the vehicle width direction to engage and disengage the external gear fixed to the end of the second front wheel drive shaft in the vehicle width direction with the internal gear formed on the cap on the wheel side.
This eliminates the conventional inconvenience in which the driver has to get out of the vehicle and manually engage and disengage the hub each time the vehicle is switched. In addition, since the drive switching of the front wheels is carried out based on the driver's direct drive method, operating efficiency is extremely high.
It is possible to speed up the switching operation and to minimize energy loss during the switching operation. Furthermore, since the configuration of the entire device is simplified, it has the advantage of being easy to manufacture.
Therefore, it is easier for the user to handle the four-wheel drive vehicle, and when driving with rear-wheel drive, the steering wheel becomes lighter, the steering angle becomes deeper, fuel consumption is lowered, and vibration and noise are reduced. It is something that plays.

[Brief explanation of drawings]

FIG. 1 is a front view of essential parts showing an embodiment of the front wheel drive switching device according to the present invention, FIG. 2 is a partial front view showing an example of the structure of the front wheel drive shaft, and FIGS. 2 is an enlarged cross-sectional view of the main part of FIG. 2, FIG. 5 is an explanatory diagram of the operation of the present invention, and FIG. 6 is a longitudinal cross-sectional view of the main part of the switching lever. DESCRIPTION OF SYMBOLS 1... Working gear, 2... (first) front wheel drive shaft, 3, 3a... Cylinder, 4... Wheel, 5...
Front wheel mounting part, 6... Steering knuckle, 8...
...Front tire, 9... External gear, 10, 14...
Concave joint, 11... (second) front wheel drive shaft,
12a...(first) universal joint, 12...(second) universal joint
) Universal joint, 13, 16... Convex joint, 2
2...Internal gear, 22a...Toothless part, 23...Cap, 26...Protrusion, 27...Wire connection part,
28...Wire, 29...Shift lever, 30...
...Switching lever, 31...Operation plate, 33...Hook, 36...Lock rod, 38, 43...Spring.

Claims (1)

[Scope of utility model registration request] In an automobile capable of switching between two-wheel drive and four-wheel drive, the front wheel drive shaft is divided into a first front wheel drive shaft and a second front wheel drive shaft, and the differential gear and the first front wheel drive shaft are connected to each other. The first front wheel drive shaft is extendable and retractable in the vehicle width direction and is connected using a first universal joint that presses and biases the first front wheel drive shaft in the vehicle width direction under normal conditions. A second front wheel drive shaft is connected to the front wheel drive shaft using a second universal joint that is expandable and retractable in the vehicle width direction, and an external gear is fixed to an end portion of the second front wheel drive shaft in the vehicle width direction. On the other hand, the wheel is provided with a front wheel mounting portion that rotatably supports the second front wheel drive shaft, and the second front wheel drive shaft is integrally provided with the front wheel mounting portion.
a cap having an internal gear that engages and disengages from the external gear of the second front wheel drive shaft; A pair of tubes having mating portions are arranged so that their cut surfaces face each other, and the tube on the wheel side is fixed to the front wheel mounting portion, while the tube on the differential gear side is in contact with the second universal joint. By bringing it into contact with
When the tube on the differential gear side is rotated by operating a lever provided near the driver's seat, the external toothed gear of the second front wheel drive shaft that the tube comes into contact with is removed from the internal teeth formed on the cap. A front wheel drive switching device characterized by being configured to engage and disengage.