JP2518821B2 - Drive system for four-wheel drive vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention provides a remote controlled electromagnetic lock hub.
The present invention relates to a drive system for a wheel drive vehicle.

(Prior Art) Conventionally, in a drive system for a four-wheel drive vehicle, for example,
Taking the method of switching between FR-2WD and 4WD as an example, one with a manual hub that connects and disconnects the front wheel axle shaft and the wheel side by manual operation, or automatically starts when running in four-wheel drive state 2. Description of the Related Art There is known a vehicle including an auto hub that connects between a front wheel axle shaft that receives torque transmission and a wheel.

(Problems to be Solved by the Invention) However, in a four-wheel drive vehicle equipped with a manual hub, it is necessary to get off each time to switch hubs. The vehicle operation required that the vehicle be backed in the two-wheel drive state after the vehicle was stopped to release the hub lock.

(Means for Solving Problems) The present invention has been made in view of such conventional problems, and locks the hub only by the switch operation without getting off the vehicle or requiring special vehicle operation. Another object of the present invention is to provide a drive system for a four-wheel drive vehicle that can be easily unlocked.

In order to achieve this object, the present invention has a transfer having a shift mechanism that switches between two-wheel drive and four-wheel drive, and from the transfer, a front wheel and a propeller shaft, a differential device, and an axle shaft are used. Alternatively, in a drive system for a four-wheel drive vehicle that transmits power rotation to each of the rear wheels, a lock hub provided on the front wheel or the rear wheel to connect the axle shaft and the wheel by a differential of a hub actuator, and a shift switch are used. Two
When the shift switch is operated at the time of instructing to shift from four-wheel drive to four-wheel drive, the hub actuator is operated to the hub lock position, and then the shift actuator that switches the transfer shifts from two-wheel drive to four-wheel drive. When a shift switch operation is performed at the time of a shift instruction from four-wheel drive to two-wheel drive, the hub actuator is operated to the unlocked position, and then the shift actuator that switches the transfer shifts from four-wheel drive to two-wheel drive. And a control means.

(Embodiment) FIG. 1 is an explanatory view of a four-wheel drive system showing an embodiment of the present invention.

First, the structure will be described. 1 is a transfer, which receives a power rotation from an engine through a transmission with a main drive shaft 2 and switches to a four-wheel drive at a high speed (4H), a neutral (N) and a low speed (4L). The power rotation is transmitted to the rear drive shaft 4 arranged in the center through system via the speed change mechanism 3 for switching the speed. A sprocket gear 6 is coaxially and relatively rotatably provided on the rear drive shaft 4, and a chain 9 is provided between the sprocket gear 8 and a sprocket gear 8 fixed to a front drive shaft 7 which is arranged in parallel with a predetermined axial distance from the sprocket gear 6. Are running around. A clutch gear 10 is integrally provided on the right side of the sprocket gear 6, a spline hub 11 fixed to the rear drive shaft 4 is provided facing the clutch gear 10, and two wheels are provided around the clutch gear 10 and the spline hub 11. A coupling sleeve 12 for switching between drive and four-wheel drive is fitted so as to be movable in the axial direction.

As such a transfer 1, for example, JP-A-60
The one disclosed in No. 215160 can be used.

The rear propeller shaft 13 is connected to the rear drive shaft 4 of the transfer 1, and the rear propeller shaft 13
The power rotation is distributed to the left and right rear axle shafts 15R, 15L via the rear differential device 14, and the left and right rear wheels 16
R and 16L are directly connected.

On the other hand, the front drive shaft 7 of the transfer 1
A front propeller shaft 17 is connected to the front propeller shaft 17, and the power rotation of the front propeller shaft 17 is performed via a front differential device 18 on the left and right front accelerator shafts 19.
It is transmitted to R and 19L. The transmission of power rotation from the front axle shafts 19R, 19L to the left and right front wheels 21R, 21L is performed by lock hubs 20R, 20L that are remotely operated by a hub actuator that will be described later.

Each of the lock hubs 20R, 20L has, for example, a spline shaft portion on the side of the axle shafts 19R, 19L, and a coupling sleeve provided with a spline shaft hole slidable in the axial direction with respect to the spline shaft portion of the wheel 21R, It is located on the 21L side, and while the wheel-side coupling sleeve is built in, it is moved axially by a hub actuator that is operated by hydraulic pressure or air pressure so that it can be engaged with the spline shaft on the axle shaft side. Of course, when the supply of the hydraulic pressure or the pneumatic pressure to the hub actuator is cut off, the coupling sleeve meshed with the spline shaft is pushed back to the wheel side by the force of the return spring to be in the unlocked state.

2 shows a lock hub 20 provided in the drive system shown in FIG.
FIG. 3 is a block diagram showing an embodiment of a control device for performing shift switching between two-wheel drive and four-wheel drive in R, 20L and transfer 1.

In FIG. 2, 22 is a shift switch, which is 2WD and 4
A switch output corresponding to each shift operation of 4H-N-4L in the state of switching WD and switching to 4WD is generated. As the shift switch 22, for example, the one having the structure shown in FIG. 3 is used.

In FIG. 3, reference numeral 24 is a shift lever, and the shift lever 24 can be rotated around a shaft 25 to perform an operation to any of the illustrated 2W-4H-N-4L shift positions in accordance with a linear shift pattern. By doing so, the protrusions 26a of the cam plate 26 fixed to the shift lever 24 actuate the limit switches 27a to 27d provided at each shift position to generate a switch output corresponding to each shift position. Of course, the shift switch 22 is not limited to the structure shown in FIG. 3, and may be a push button switch.

Referring again to FIG. 2, reference numeral 28 is a traveling sensor, which produces a detection output indicating whether the vehicle is in a stopped state or in a traveling state. The outputs of the shift switch 22 and the travel sensor 28 are given to the controller 30, which then controls the left and right front wheels 21R, 21L under the control conditions shown in the flowchart of FIG.
2W-4H-N-4 in the transfer 1 and hub actuators 32R, 32L for driving the lock hubs 20R, 20L
The shift actuator 34 for switching L is driven.

Next, shift control of the lock hubs 20R, 20L and the transfer 1 by the controller 30 shown in FIG. 2 will be described with reference to the flowchart of FIG.

Now, as shown in Fig. 3, the shift lever is in the 2W position.
Assuming that a shift operation of switching 24 to, for example, 4H is performed, the determination block 40 determines the shift operation based on the switch input from the shift switch 22, and the determination block 41
Go to and check if it is a shift operation from 2W to 4W. At this time, since the shift is from 2W to 4H, the process proceeds to a determination block 42, and it is checked whether or not the vehicle is traveling based on the detection output of the traveling sensor 28 at that time. If the vehicle is running, proceed to block 43, first output a control signal for hub lock to the hub actuators 32R, 32L to operate the lock hubs 20R, 20L in the locked state, and lock hub 2
The left and right front wheels 21R, 21L are connected to the front axle shafts 19R, 19L via 0R, 20L.

When the block lock shown in this block 43 is completed, the process proceeds to the next block 44, which is a shift operation to 4W,
The shift actuator 34 is operated to switch the speed change mechanism 3 of the transfer 1 to the 4H shift position, and the coupling sleeve 12 is switched to the 4W shift position where the illustrated clutch gear 10 and the spline hub 11 mesh with each other.

On the other hand, when the determination block 42 determines that the vehicle is in the stopped state, the process proceeds to block 45, the hub actuators 32R and 32L and the shift actuator 34 are simultaneously actuated, and the lock hubs 20R and 20L have the hub lock state and the transfer 1 4H. Creates a shift state of. In other words, when the vehicle is traveling, be sure to
Although the shift to 4W is performed, when the vehicle is stopped, either the haslock or the shift to 4W may be preceded or may be performed simultaneously.

Next, if the shift state from 4H is returned to 2W, the process proceeds from the determination block 41 to the determination block 46, and the determination block
The shift to 2W is judged to be 46, and the process proceeds to a judgment block 47,
Check if you are driving. If it is running, proceed to block 48, release the block, and then shift to 2W at the next block 49. On the other hand, when the vehicle is in the stopped state, the routine proceeds to block 50, where the unlocking and the shift to 2W are simultaneously performed.

For this shift to 2W as well as the shift to 4W
When the vehicle is running, first release the hublock and then shift to 2W.When the vehicle is stopped, either release the hublock or shift to 2W may precede. You may do it.

Further, when the shift operation is performed within the range of 4H-N-4L in the state of being switched to 4W, the process proceeds to the block 51 through the determination blocks 41 and 46 to move to one of the shift positions of 4H-N-4L. The shift is switched to the 4W state accordingly.

In the above embodiment, the transfer 1 is 2W-4H-
The N-4L switching is performed by the shift actuator 34, but as another embodiment, the transfer 1
The shift operation may be performed mechanically by transmitting the movement of the shift lever 24 to the transfer 1 by the control rod. In this case, the shift mechanism of the transfer 1 is provided with an interlock mechanism, and the interlock mechanism is provided during traveling. The lock hubs 20R and 20L are locked and unlocked prior to the shift operation.

In addition, the above-mentioned embodiment was an example of the switching system of 2W-FR and 4W, but in the drive system of 2W-FF and 4W, a hub actuator is used between the rear axle shaft and the wheels. It suffices to provide an activated lock hub.

(Effect of the Invention) As described above, according to the present invention, the lock hub that connects the axle shaft and the wheel is provided by the operation of the front wheel or rear wheel hub actuator, and the shift operation from the two-wheel drive to the four-wheel drive is performed. Based on the operation of the hub actuator, the lock hub is operated to have the hub lock, and the hub actuator is released based on the shift operation from the four-wheel drive to the two-wheel drive to unlock the lock hub. It is not necessary to get off and operate the hub like a conventional manual hub, and the vehicle operation to release the hub lock by backing the vehicle while switching to two-wheel drive like an auto hub is also unnecessary. The hub can be locked and unlocked only by operating the shift lever or push button switch. The operability of the four-wheel drive system can be greatly improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a system showing an embodiment of the present invention, FIG. 2 is a block diagram showing an embodiment of a control device for the lock hub of FIG. 1, and FIG. 3 is a diagram of the shift switch of FIG. FIG. 4 is an explanatory diagram showing an example, and FIG. 4 is a flowchart showing the lock hub control of the present invention by the control device of FIG. 1: Transfer 2: Main drive shaft 3: Transmission 4: Rear drive shaft 6,8: Sprocket gear 7: Front drive shaft 9: Chain 10: Clutch gear 11: Spline hub 12: Coupling sleeve 13: Rear propeller shaft 14 : Rear differential device 15R, 15L: Rear axle shaft 16R, 16L: Rear wheel 17: Front propeller shaft 18: Front differential device 19R, 19L: Front axle shaft 20R, 20L: Lock hub 21R, 21L: Front wheel 22: Shift switch 24: Shift lever 25: Axis 26: Cam plate 27a to 27d: Limit switch 28: Controller 32R, 32L: Hub actuator 34: Shift actuator

Claims (1)

(57) [Claims] Claim: What is claimed is: 1. A transfer having a shift mechanism for switching between two-wheel drive and four-wheel drive, wherein power is rotated from the transfer to a front wheel and / or a rear wheel through a propeller shaft, a differential device, and an axle shaft. In a drive system for a four-wheel drive vehicle that transmits power, a lock hub that is provided on the front wheel or the rear wheel and connects the axle shaft and the wheel with a differential of a hub actuator, and a two-wheel drive to a four-wheel drive by a shift switch 2) by operating the hub actuator to the hub lock position after operating the shift switch when the shift instruction is issued, and then switching the transfer.
A shift actuator that shifts from four-wheel drive to four-wheel drive and operates the hub actuator to the unlocked position after operating a shift switch when a shift instruction from four-wheel drive to two-wheel drive is performed, and then switches the transfer. A drive system for a four-wheel drive vehicle, which is provided with control means for shifting from four-wheel drive to two-wheel drive.