JPH0960658A - Synchro-mechanism of transfer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a transfer used for a four-wheel drive vehicle so as to reduce the operating physical force of a driver, and also prevent the sleeve of a switching mechanism from being slipped off without providing a special mechanism. SOLUTION: In a hub 40 which is a member on the driven wheel side of a transfer, a movable member 43 which is moved by centrifugal force, and by which a sleeve 31 is pushed to the connecting position of a four-wheel drive vehicle by the plate body 45 which is a part thereof when the movable member 43 is moved, is attached to the projected part 42 of the hub 40 by a shaft 44. Therefore, the movement of the movable member 43 helps the operating physical force of a driver by the centrifugal force, and the sleeve 31 is retained in the connecting position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer synchronizing mechanism applied to a four-wheel drive vehicle in which a driven wheel side is provided with a free axle mechanism or a freewheel hub mechanism.

[0002]

2. Description of the Related Art Among four-wheel drive vehicles, so-called full-time type vehicles do not require a two-wheel / four-wheel switching mechanism because the four wheels are always driven. Since a person switches between four-wheel drive and two-wheel drive as needed, a transfer (sub-transmission) as a mechanism for that is required. When the transfer is operated for two-wheel drive, the separated wheel (following wheel during four-wheel drive) rotates when the vehicle is running, and when it reaches the part separated by the transfer, the bearing and other parts wear. It also causes noise. Therefore, even if the wheels separated by transfer rotate due to the running of the vehicle,
A so-called free axle mechanism or a freewheel hub mechanism is used which cuts off power transmission before the rotation is transmitted to the transfer.

FIG. 3 shows a drive system layout of a four-wheel drive vehicle. Reference numeral 1 is an engine, and 2 is a transmission coupled to the engine. The output shaft 3 of the transmission 2 is connected to the input shaft 6 of the transfer 5 via a propeller shaft 4. The transfer 5 is provided with two output shafts 7 and 8. With a known structure, the rotational force of the input shaft 6 is transmitted to both output shafts 7 and 8, and only one output shaft 8 is transmitted. The switching between the operation and the operation is performed. An input shaft 11 of a differential gear 10 is connected to the output shaft 8 via a propeller shaft 9. Left and right driving wheels 13 are attached to the output shaft 12 of the differential gear 10.

An output shaft 7 of the transfer 5 is connected to an input shaft 16 of a differential gear 15 via a propeller shaft 14. One of the output shafts 17 of the differential gear 15 is connected to the axle 20 via a free axle mechanism 18, and the other is directly connected to an axle 20 via a propeller shaft 19, and driven wheels 21 are attached to the axle 20.

In this layout, the rotational force generated by the engine 1 is decelerated by the transmission 2 to an appropriate rotational speed and input to the transfer 5. In the transfer 5, two-wheel drive and four-wheel drive are switched by the driver's operation. In the case of two-wheel drive, output is generated only on the output shaft 8, and in the case of four-wheel drive, output is generated on both output shafts 7 and 8. Therefore, in the case of two-wheel drive, the driving wheel 13
Power is applied only to the drive wheels 13 when four-wheel drive is used.
Both the driven wheel 21 and the driven wheel 21 are powered to travel.

There are two types of mechanisms of the transfer 5, that is, the input is performed through a chain and the input is performed through a gear. FIG. 4 shows the structure around the output shaft on the driven wheel side of the one using the chain in different states from the half to the upper side and the lower side. The output shaft on the main driving wheel side is not shown. As shown in the drawing, the output shaft 7 on the driven wheel side is supported by a housing (not shown) by a ball bearing 22, and is opposed to a drive shaft 24 similarly supported by a ball bearing 23. A sprocket 25 is attached to the outer periphery of the drive shaft 24, and receives a rotational force from the transmission 2 (see FIG. 3) via a chain 26 and an input shaft (not shown).

A hub 27 is coupled to the tip portion of the output shaft 7 supported by the ball bearing 22.
A hub 28 is attached to the end of 4 so as to face the hub 27. Splines 29 and 30 are engraved on the outer peripheries of the hubs 27 and 28, and a sleeve 31 is slidably fitted to the spline 29 and moves to the spline 30 side as described later. A recess 32 is formed on the outer circumference of the sleeve 31.
Is provided, and the projection 35 of the shifter 34 attached to the switching lever 33 engages with the recess 32.

In this mechanism, the switching lever 33 is moved to the right, and the sleeve 31 moves the hub 2 as shown in the lower part of the figure.
When engaged with both 7, 28, the rotational force of the drive shaft 24 rotating from the chain 26 via the sprocket 25 is transmitted to the output shaft 7 via the hub 28, the sleeve 31, and the hub 27. The output shaft 7 is rotated. In this state, four-wheel drive is used. Next, the switching lever 33 is moved to the left, and the sleeve 31 moves to the hub 28 as shown in the upper part of the drawing.
If the drive shaft 24 and the output shaft 7 are disengaged from each other and engage only with the hub 27, the output shaft 7 does not rotate because the drive shaft 24 and the output shaft 7 are disconnected.

[0009]

In the above-described operation, the force for moving the sleeve 31 is applied by the driver by operating an operation lever (not shown) linked to the switching lever 33. Therefore, when the vehicle speed is high, the resistance against the movement of the sleeve 31 increases, so that the operation force of the operation lever increases and the driver is fatigued. Also, when switching from two-wheel drive to four-wheel drive, the sleeve 31 causes both hubs 27, 28 to
Since the operating force cannot be loosened until it is securely connected to the above, there is a problem that the operation becomes complicated. Furthermore, in order to prevent the sleeve 31 from coming off the hub 28 during traveling,
It is necessary to form a taper on the spline 30 to prevent the sleeve 31 from coming off, or to harden the connection between the spline 30 and the sleeve 31.

The present invention has been made in view of this point, and reduces the switching operation force of the driver and, in particular,
Even if the spline 30 is not formed with a taper for preventing the sleeve 31 from coming off or the spline 30 and the sleeve 31 are not firmly coupled, the sleeve does not come off from the hub during traveling of the vehicle. , Is intended to provide a transfer synchronization mechanism.

[0011]

In order to solve the above-mentioned problems, the present invention provides a four-wheel drive vehicle having a free axle mechanism or the like on the driven wheel side in the invention described in claim 1. In the transfer, a movable member that moves to the driven wheel side of the transfer by a centrifugal force and a part of which pushes the sleeve to the four-wheel drive coupling position during the movement is pivotally supported.

Further, in the invention described in claim 2, in a transfer of a four-wheel drive vehicle in which a free axle mechanism or the like is provided on the driven wheel side, the driven wheel side of the transfer is moved by centrifugal force, A part of the driven wheel side member is formed as a stopper part for restricting the movement of the movable member, while a part of the driven wheel side member pivotally supports a movable member that presses the sleeve to a four-wheel drive coupling position during movement. And

When the driver operates the operation lever in order to switch from the two-wheel drive to the four-wheel drive, the sleeve, which has been on the driven wheel side until then, moves to the four-wheel drive coupling position. When the sleeve starts to apply the rotational force to the driven wheel side, the movable member provided on the driven wheel side moves by receiving the centrifugal force and presses the sleeve to the four-wheel drive coupling position. This pressing force reduces the force to move the operation lever. If a part of the driven wheel side member is formed as a stopper portion that restricts the movement of the movable member, the movable member will not push the sleeve more than necessary.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG. 1 and with the same parts as in FIG. The switch lever is not shown. In this figure, input is performed via gears, and the drive shaft 36 receives rotational force from the transmission 2 (see FIG. 3) via an input shaft (not shown). A hub 37 is integrally provided on the drive shaft 36, and a spline 30 is engraved on the outer periphery thereof. A reduced diameter portion 38 is provided in a portion of the drive shaft 36 ahead of the hub 37, and a hub 40 integrally formed with the output shaft 7 is formed on the outer periphery of the reduced diameter portion 38 via a needle bearing 39, and a recess 41 is formed. It is rotatably supported by the part.

A spline 29 is engraved on the outer periphery of the hub 40, and a sleeve 31 is slidably fitted to the spline 29 and moves to the spline 30 side as described later. A concave portion 32 is provided on the outer circumference of the sleeve 31, and the convex portion 35 of the shifter attached to the switching lever engages with the concave portion 32.

A part of the hub 40 radially projects to the outer periphery of the output shaft 7, and the base of the projecting portion 42 has the base of the movable member 43 pivotally supported by the shaft 44. The movable member 43 is composed of a substantially L-shaped plate body 45 and a weight 46 provided on the bending portion thereof. Weight 4
6 has a rectangular shape, and as shown in the upper half of the figure, when the plate body 45 does not push the sleeve 31 because the centrifugal force does not act, the lower corner portion 46a contacts the upper side of the protrusion 42. Further, the clockwise rotation of the movable member 43 is restricted. At this time, the sleeve 31 is the plate body 45.
Since there is no further leftward movement, the so-called gear loss does not occur.

When the plate member 45 pushes the sleeve 31 by the centrifugal force as shown in the lower half of the figure, the inner side 45a of the plate member 45 contacts the side surface 40a of the hub 40, and the movable member 43 is moved.
Is formed on the stopper portion that does not push the sleeve 31 any further. In other words, the movable member 43 moves only in the range surrounded by the sleeve 31 and the protrusion 42 of the hub 40. Further, since the sleeve 31 constantly pushes the plate body 45 of the movable member 43 by the locating mechanism (not shown) of the switching lever system, the movable member 43 does not vibrate,
No abnormal noise is generated.

In this structure, the switching lever is operated to shift from the two-wheel drive state to the four-wheel drive state, and the sleeve 3
1 is moved to the right in FIG. 1, a member on the driven wheel side (hub 40
Part of it) begins to rotate. The movable member 4 is attached to the hub 40.
Since 3 is pivotally supported, centrifugal force acts on it. Due to the positional relationship between the shaft 44 and the weight 46, the centrifugal force moves (rotates) clockwise around the shaft 44 from the state shown in the upper half of FIG. The tip of 45 contacts the sleeve 31.

The state shown in the lower half of this figure is the sleeve 3
Although 1 has moved sufficiently and is in the four-wheel drive coupling position, the centrifugal force acting on the movable member 43 in this process adds to the moving force of the sleeve 31. Therefore, the force required by the driver to move the sleeve 31 can be reduced. When the movable member 43 is in the state shown in the lower half of the figure, the inner side 45a of the plate body 45 contacts the side surface 40a of the hub 40, so that the plate body 45 does not push the sleeve 31 any further. Therefore, no extra force is applied to the sleeve 31. Further, since the sleeve 31 is held in that position, the sleeve is separated from the hub during the traveling of the vehicle without the need to take measures such as hardening the connection between the spline 30 and the sleeve 31, which has been conventionally done. There is no such thing.

FIG. 2 shows another example of the embodiment of the present invention. This is an application of the present invention to the chain drive type transfer shown in FIG. 1 except that the input is via the chain 26 and the sprocket 25.
Since there is no difference from the one shown in FIG. 2, the same reference numerals as those in FIGS.

[0021]

The present invention is a transfer synchronizing mechanism constructed as described above. According to the invention described in claim 1, since the movable member provided on the driven wheel side of the transfer reduces the driving force of the operation lever, if a centrifugal force acts on the movable member, the force applied to the operation lever thereafter is applied. Even if you pull it out, the conversion operation will be performed automatically.
The switching is completed in a short time. During two-wheel drive, the movable member prevents so-called gear loss.

According to the invention described in claim 2, in addition to the above effect, since the movable member hits a part of the driven wheel side member to restrict the movement, it is possible to push the sleeve with an excessive force. In addition, abrasion resistance is improved and abnormal noise can be prevented.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a main part of an embodiment of the present invention in different states from an upper part to a lower part.

FIG. 2 is a partial cross-sectional view showing a main part of another embodiment of the present invention in a different state from the center to the upper part and the lower part.

FIG. 3 is an explanatory diagram showing a drive system layout of a four-wheel drive vehicle.

FIG. 4 is a partial cross-sectional view showing a conventional transfer.

[Explanation of symbols]

 5 Transfer 7 Output Shaft 31 Sleeve 36 Drive Shaft 37 Hub 40 Hub 40a Side of Hub 43 Movable Member 44 Shaft 45 Plate 45a Inner Side of Plate 46 Weight

Claims (2)

[Claims] 1. A transfer of a four-wheel drive vehicle in which a free wheel mechanism or the like is interposed on the driven wheel side, is moved by centrifugal force to the driven wheel side of the transfer, and at the time of the movement, a part of the sleeve is a four-wheeled vehicle. A transfer synchronizing mechanism characterized in that a movable member that is pressed against a drive connecting position is pivotally supported. 2. A transfer of a four-wheel drive vehicle in which a free axle mechanism or the like is interposed on the driven wheel side, is moved by centrifugal force to the driven wheel side of the transfer, and at the time of the movement, a part of the sleeve is a four-wheeled vehicle. A synchro mechanism for a transfer characterized in that a movable member which is pressed against a drive coupling position is axially supported, and a part of the driven wheel side member is formed as a stopper portion for restricting movement of the movable member.