JPH039441Y2 - - Google Patents

Description

[Detailed Description of the Invention] "1" Technical Field of the Invention The present invention relates to a support structure for a rear axle shaft used in a four-wheel drive vehicle that can freely switch between so-called two-wheel drive and four-wheel drive.

"2" Background of the present invention As a result of past research, the applicant has developed a four-wheel drive vehicle as shown in Fig. 1. This is a pair of left and right front axle shafts 2 as shown in the figure.
a and 2b are connected to the engine 1 via a front differential 3. The front differential 3 is connected to a rear differential 6 via a transfer shaft 4 and a propeller shaft 5, and left and right rear axle shafts 7a and 7b are connected to the rear differential 6. 8a and 8b are front axle shaft 2
These are the front wheels attached to a and 2b. One side 7a of the rear axle shafts is divided into a distal end shaft 7a' and a distal end shaft 7a'', and a remotely controllable clutch 9 is interposed between them, and the shaft ends of the rear axle shafts 7a and 7b are respectively Rear wheels 10a and 10b are attached.

In such a four-wheel drive vehicle, a dog-type clutch is used as the clutch 9, which is driven by an actuator _AC2 using negative pressure, and the clutch 9 is turned on (connected) by supplying the negative pressure. Various sources of negative pressure can be considered to operate the clutch 9, but in this four-wheel drive vehicle, the intake manifold 11 of the engine 1 is used, and the intake manifold 11 of the engine 1 is used as the negative pressure source that operates the clutch 9. Vacuum switch valve VSV ₂ is installed in the middle. Further, the transferor 4 employs a synchronizing mechanism, and a vacuum switch valve VSV ₁ is interposed in the middle of a pipe 13 that connects the intake manifold 11 and the actuator AC ₁ that is the drive source of the transferor 4. Both vacuum switch valves VSV ₁ and
Between the VSV ₂ and the power supply that excites it, there is a self-holding 4-wheel/2-wheel selector switch 14 located at an appropriate location in the vehicle interior, for example, on the front panel of the driver's seat.
is intervening. In addition, in this example, the 4-wheel to 2-wheel changeover switch 14 and the vacuum switch valve are
A delay circuit D is interposed between the VSV2 and the _VSV2 .

When switching such a four-wheel drive vehicle from a two-wheel drive state with the transfer 4 turned off and the clutch 9 turned off, the driver must
The wheel changeover switch 14 is closed. This switching is possible even while the vehicle is running. As a result, the vacuum switch valve VSV ₁ is first opened, the negative pressure of the intake manifold 11 acts on the actuator AC ₁ , the transfer 4 becomes connected, and the rotation of the front differential 3 is transmitted to the propeller shaft 5. , the propeller shaft 5 begins to rotate in synchronization with the traveling speed. The vacuum switch valve VSV ₂ is switched to the open state later than the switching of the vacuum switch valve VSV ₁ by the delay rotation D. When the vacuum switch valve VSV ₂ is switched to open as described above, the propeller shaft 5 has already begun to rotate in synchronization with the vehicle's running speed, and this causes the end of the rear axle shaft 7a on the side of the rear differential 6 to Since the rotational speed of the shaft 7a' is equal to the rotational speed of the tip end shaft 7a'' on the rear wheel 10a side and the rear axle shaft 7b, the clutch 9 can be engaged at this point, and the clutch 9 can be engaged at this time without any impact. It never occurs.

In this way, this four-wheel drive vehicle has the advantage of having less power loss when driving two wheels and being able to switch from two to four wheels, with less shock being applied to the clutch. A clutch 9 is interposed between the tip end shaft 7a'' and the distal shaft 7a', and in particular, the tip end shaft 7a'' has one end connected to the rear wheel 10a and the other end connected to the clutch 9. Since they are only connected, they tend to whirl around and vibrate, which accelerates wear on the various connecting parts, adversely affecting riding comfort and causing poor engagement of the clutch.

3. Structure and Effects of the Present Invention The present invention aims to eliminate the above-mentioned drawbacks, and the main point of its structure is to improve the structure of the rear axle shaft that connects the rear differential and the rear wheels. In a support structure for a rear axle shaft in a four-wheel drive vehicle with a clutch interposed in the middle, the rear axle housing that covers the rear axle shaft is divided into left and right parts between the clutch and the rear wheel mounting part, and the divided parts are welded. At the same time, a ring member is press-fitted inside the divided portion across both of the left and right divided rear axle housings, and a bearing fitted to the inner surface of the ring member connects the clutch of the rear axle shaft and the rear wheel. This is the point where the parts to be connected are supported.

The bearings in the above-mentioned components can be constituted by ball bearings, roller bearings, other bearings and bushes, metal or other bearing means.

Since the present invention is constructed in this way,
In addition to reliably supporting the rear axle shaft that connects the clutch and the rear wheel and preventing vibration, the ring member also reinforces the welded structure of the divided portion of the rear axle housing and prevents distortion during welding, thereby improving the stability of the left and right housings. It plays the role of centering and prevents damage caused by clutches, etc. that can easily occur at the split part.

``4'' Embodiment Next, an embodiment embodying the present invention will be described using the attached drawings starting from FIG. 2 to provide an understanding of the present invention. Note that this embodiment is a specific example of the present invention, and does not limit the technical scope of the present invention.

FIG. 2 is a partial side view of a rear axle housing showing a support structure for a rear axle shaft according to an embodiment of the present invention (however, the well-known differential mechanism and clutch mechanism are partially omitted); 3 is a sectional view taken in the direction of the arrow in FIG. 2, FIG. 4 is a sectional view taken in the direction of the arrow in FIG. 3,
5 is a partial cross-sectional view taken along the arrow 3 in FIG. 3, FIG. 6a is a schematic side view of the entire rear differential housing, and FIG. 6b is a schematic plan view thereof.

Rear axle housing shown in Figures 6a and b
20 is a pressed product, which includes the center housing 21, right housing 22, and left housing 2 in FIG.
As shown in FIG. 6a, the central housing 21 consists of an upper housing 21a and a lower housing 21a, both of which are joined at a parting line 24 by welding. Further, the center housing 21 and the right housing 22 are connected at the dividing line (junction 25), and the central housing 21 and the left housing 23 are connected at the dividing line (junction 26).
Each is welded.

As shown in FIG. 2, one side wall 27 of the central housing 21 divided by the dividing line 24 is provided with a rear differential mounting hole 28 and a clutch mounting hole 29, respectively. A reinforcing ring 30 is welded to the outer edge of the rear differential mounting hole 28, and a reinforcing ring 31 is welded to the outer edge of the clutch mounting hole 29, respectively. The upper surfaces 30a and 31a of these reinforcing rings 30 and 31 (see FIG. 4) are
1 is welded to the planar side wall 27, so that it exists on approximately the same plane and can be processed continuously by milling, etc., and moreover, the parting line 24, which is structurally weak due to welding, Welded, dividing line 24
This prevents clutches, etc. in the parts. The rear differential mounting hole 28 and the clutch mounting hole 29 are respectively closed by a rear differential carrier 32 and a clutch cover 33. 34 is a rear differential back cover.

A rear differential (not shown) housed in the rear differential carrier 32 and the left and right rear wheels 10a, 10a are connected by a rear axle shaft. The rear axle shaft is divided into a distal shaft 7a' and a distal shaft 7a'' at the clutch 9. That is, the distal end 37 of the distal shaft 7a'' is connected to the distal shaft 7 via a bush 38.
The outer peripheral teeth 41 of the clutch gear 40 are fitted coaxially with the distal end portion 39 of the distal shaft 7a′ and are spline-fitted to the distal shaft 7a″, and the outer peripheral teeth formed on the outer periphery of the distal end portion 39 of the distal shaft 7a′. The clutch hub 4 has the same shape as 42 and meshes with the clutch gear 40.
By sliding 3 in the axial direction, the outer tooth 4
2 and the clutch hub 43 are engaged and separated, and the clutch 9 is engaged and disengaged.

The center housing 21 and the left housing 23
A centering and auxiliary ring member 44 that spans both the center housing 21 and the left housing 23 is press-fitted into the inner surface of the joint portion 26 with the center housing 21 and the left housing 23. Therefore, the bending stress applied to the joint 26 by the ring member 44 is alleviated, and the welded joint 26
This prevents clutches from occurring.

A bushing 45 (bearing) is fitted into the inner surface of the ring member 44, and the bushing 45 rotatably supports the tip end shaft 7a''.Therefore, support of the tip end shaft 7a'' is ensured. This prevents whirling and vibration.

As shown in FIGS. 3 to 5, a guide shaft 46 parallel to the rear axle shaft is slidably attached to the clutch cover 33 in the axial direction, and a fork 47 fixed to the guide shaft 46 is attached to the clutch hub 43. It fits into the outer circumferential groove 48 of. In addition, the drive groove 49 provided in the fork 47
A tip 51 of a swingable lever 50 attached to the clutch cover 33 is fitted into the lever 5.
0 as shown by the arrow 52 in FIG. 5, the fork 47 is slid in the axial direction of the rear axle shaft, and the engagement between the clutch hub 43 and the outer tooth 42 provided at the tip of the distal shaft 7a' is established. If,
Disconnection, that is, connection/disconnection of the shaft 9 is performed.

[Brief explanation of drawings]

Fig. 1 is a drive system diagram of a four-wheel drive vehicle, and Fig. 2 is a partial side view of a rear axle housing showing a support structure for a rear axle shaft according to an embodiment of the present invention (however, a well-known differential mechanism and clutch are shown). (Part of the mechanical part is omitted), Fig. 3 is a sectional view taken along the - arrow in Fig. 2, and Fig. 4 is a sectional view taken along the - arrow in Fig.
5 is a partial sectional view taken in the direction shown in FIG. 3, FIG. 6a is a schematic side view of the entire rear differential housing, and FIG. 6b is a schematic plan view thereof. Explanation of symbols, 6... Rear differential, 1
0a, 10b... Rear wheel, 7a, 7b... Rear axle shaft, 9... Clutch, 21, 22, 2
3... Rear axle housing, (21... Center housing, 22... Right side housing,) 23...
...Left side housing, 25, 26...Joint part (divided part), 44...Ring member, 45...Bushion (bearing).

Claims (1)

[Scope of utility model registration request] In a support structure for a rear axle shaft in a four-wheel drive vehicle in which a clutch is interposed between the rear axle shaft that connects a rear differential and the rear wheels, a rear axle housing that covers the rear axle shaft is placed between the clutch and the rear wheel mounting portion. The rear axle housing is divided into left and right parts, the divided parts are joined by welding, and a ring member is press-fitted inside the divided part across both of the left and right parts of the rear axle housing, and the bearing is fitted on the inner surface of the ring member. A support structure for a rear axle shaft in a four-wheel drive vehicle, characterized in that a portion of the rear axle shaft connecting a clutch and a rear wheel is supported by a support structure for a rear axle shaft in a four-wheel drive vehicle.