JPS6340686B2 - - Google Patents

Description

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

The present invention is applicable to a part-time type that has a transfer device for switching between two and four-wheel drive and switches to four-wheel drive when necessary, or a full-time type that does not have a transfer device and constantly drives four wheels. This invention relates to drive vehicles, and particularly relates to vehicles with one-way clutches installed in the middle of the transmission system for front and rear wheels.

[Conventional technology and issues]

As a four-wheel drive vehicle without a center differential, a vehicle in which the transmission systems of the front and rear wheels are directly connected by a clutch has been proposed, for example, as shown in Japanese Patent Application Laid-open No. 55-4292. However, with this front and rear wheel direct connection type, 4
When turning with wheel drive, if there is a difference in the turning radius of the front and rear wheels, a so-called tight corner braking phenomenon occurs. Therefore, in order to avoid such a braking phenomenon, an automatic switching device to two-wheel drive based on the steering angle is required, as shown in Japanese Patent Application Laid-Open No. 57-15019, which makes the structure complicated and further improves the road surface. When the occurrence of a braking phenomenon changes depending on the state, etc., there is a problem that it is difficult to avoid it accurately. Furthermore, Japanese Patent Publication No. 48-42137 has a one-way clutch. In view of these circumstances, the present invention is a four-wheel drive system in which the front and rear wheels are directly connected without having a center differential, and the present invention automatically avoids braking phenomena depending on the occurrence of the phenomenon when turning.
To provide a four-wheel drive vehicle in which engine braking is applied during forward deceleration by four-wheel drive.

[Means to solve the problem]

In order to achieve the above object, the present invention provides direct transmission to one of the front and rear wheels via a differential device, and a transfer device consisting of a two- and four-wheel switching clutch and a direction changing gear to the other wheel. In a two- or four-wheel drive device, the gear shaft of the direction conversion gear and the drive shaft for driving the other of the front and rear wheels are disposed on the same axis, and a drum connected to the gear shaft. A forward one-way clutch and a reverse one-way clutch are provided adjacent to each other on the drive shaft, and a slide sleeve is provided between the forward one-way clutch, the reverse one-way clutch, and the connecting drum. One of the forward one-way clutch and the reverse one-way clutch is selectively fitted onto the connecting drum by the slide sleeve.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. To explain the transmission system of a four-wheel drive vehicle according to the present invention in FIG. 1, it is based on the two-wheel drive of RR, and reference numeral 1 is a drive system having an engine, a clutch, and a transmission. Transmission is directly transmitted to the rear wheels 4 via the differential device 2 and the rear wheel axle 3. The rear wheel differential device 2 is connected to two sets of one-way clutches 8 and 9 via a transfer device 5, a transfer clutch 6 for switching four wheels, and a gear 7 for changing direction, and is further connected to a propeller shaft 10, a front wheel Transmission is configured to the front wheels 13 via the differential device 11 and the front wheel axle 12. In FIG. 2, the one-way clutches 8 and 9 will be described in detail. The gear shaft 14 and the drive shaft 15 to the propeller shaft 10 are arranged coaxially,
A connecting drum 16 is integrally coupled to the gear shaft 14,
A reverse one-way clutch 8 and a forward one-way clutch 9 are disposed adjacent to the drive shaft 15, and a slide sleeve 17 is mounted between these one-way clutches 8, 9 and the connecting drum 16. This sleeve 17 has spline internal teeth 17a, 1 at the front and rear.
7b, and is moved in the axial direction with the rear spline internal teeth 17b always fitted to the external teeth 16a of the connecting drum 16, and the front spline internal teeth 17a are connected to the external teeth 8a, 9a of the one-way clutches 8, 9. It is designed to selectively fit into one of the two. Here, when the forward one-way clutch 9 rotates the outer race 9b, for example, in the forward rotation direction shown by the solid line arrow A in FIG. 1, it integrates the inner race 9c and transmits power.
c is allowed to rotate faster than outer race 9b. Further, the one-way clutch 8 for reverse movement operates in exactly the same manner when the outer race 8b and the inner race 8c are rotated in the opposite direction to that described above. Next, to explain the control system, a negative pressure actuator 20 is connected to the sleeve 17 via a connecting rod 21, and a passage 22 from the actuator 20 is connected to the suction pipe side passage 24 or the atmosphere by energizing or de-energizing the solenoid valve 23. Switched to port 25. A reverse switch 26 that is turned on when shifting to reverse gear and a 4WD switch 27 that is turned on when driving four wheels are connected to an OR circuit 30 via an AND circuit 29. In addition, code 2 in the figure
Reference numerals 8 and 28 indicate indicator lamps that are grounded via the switches 26 and 27, respectively, and are lit when turned on. The 4WD switch 27 also includes an accelerator switch 31 that is turned on when the accelerator pedal is fully closed;
and a vehicle speed switch 32 that turns on at a predetermined vehicle speed or higher.
and is connected to the OR circuit 30 through an AND circuit 33, and this OR circuit 30 is connected to the transistor 34.
The solenoid valve 23 is connected to the solenoid valve 23 via the solenoid valve 23. With this configuration, when driving forward with the transfer clutch 6 switched to two-wheel drive, the reverse switch 26 and the accelerator switch 3 are activated.
1 is turned off and the outputs of the AND circuits 29 and 33 both become L level, so that the solenoid valve 23 is de-energized. Then, the actuator 20 communicates with the atmospheric port 25 and becomes atmospheric pressure, so that the sleeve 17 moves rearward (to the position shown in FIG. 2) due to the spring force of the spring (not shown) inside the actuator 20 and connects with the connecting drum 16. The forward one-way clutch 9 is integrally connected. Thus vehicle 2
When the wheels are running forward, the clutch 6 of the transfer device 5
When these are coupled, the power of the drive device 1 is transmitted to the rear wheels 4, and also to the front wheels 13 via the clutch 6, one-way clutch 9, and propeller shaft 10, so that four-wheel drive forward travel is performed. At this time, when the steering is carried out, the integration of the outer race 9b and the inner race 9c of the one-way clutch 9 is dissolved based on the difference in the turning radius of the front and rear wheels 13 and 4, and the front wheel 13 rotates quickly together with the inner race 9c. This allows the vehicle to turn smoothly without causing any braking phenomena. In addition, when decelerating when moving forward with this four-wheel drive,
When the accelerator switch 31 is turned on together with the 4WD switch 27 and the vehicle speed switch 32, the AND circuit 3
The output of No. 3 becomes H level and the solenoid valve 23 is energized. Therefore, suction pipe negative pressure is introduced into the actuator 20 to move the sleeve 17 forward (to the left in FIG. 2), so that the connecting drum 16 is integrally connected to the one-way clutch 8 for reverse movement. Here, the one-way clutch 8 is such that when moving backward, the rotation of the inner race 8c is caused by the rotation of the outer race 8b.
Inner race 8 when slowing down or moving forward
Since the one-way clutch 8 is integrated when the rotation of the outer race 8b becomes faster than the outer race 8b, when the one-way clutch 8 for reverse is selected during forward driving in four-wheel drive,
The inner race 8c is no longer allowed to rotate faster than the outer race 8b, and the action of this one-way clutch 8 keeps the front wheels 13 in a directly connected state during deceleration.
Engine braking also works on 3. Next, the reverse switch 26 is turned on as the shift operation is performed when going backwards, and if the 4WD is in the 4WD state at this time, the 4WD switch 27 is also turned on, and the output of the AND circuit 29 becomes H level, and the solenoid valve 2
3 is energized. Therefore, the one-way clutch 8 for reverse is selected as in the case of deceleration, and the one-way clutch 8 is integrated with the rotation of the gear shaft 14 in the opposite direction to that during forward movement, and power is transmitted to the front wheels 13 as well, thereby transmitting power to the four wheels. The drive is running backwards. Also in this case, when steering, the front wheel 1 is smaller than the rear wheel 4.
When the turning radius of No. 3 becomes larger, the outer race 8b and inner race 8c of the one-way clutch 8 are no longer integrated, and the front wheel 13 rotates quickly and smoothly without any braking phenomenon, just like when moving forward. Turn around. Although the above embodiment describes a RR-based part-time type, it can also be applied to a FF-based part-time type, and even to a full-time type that does not have a transfer device for switching between 2- and 4-wheel drive. It is possible.

【Effect of the invention】

As is clear from the above description, according to the four-wheel drive vehicle of the present invention, direct transmission is provided to one of the front and rear wheels via a differential device, and the other is provided with a two- and four-wheel switching clutch and a direction changer. In a two- or four-wheel drive device, the gear shaft of the direction changing gear and the drive shaft for driving the other of the front and rear wheels are disposed on the same axis, and the transmission is configured via a transfer device consisting of a gear. The connecting drum is integrally connected to the gear shaft, and the drive shaft is
A forward one-way clutch and a reverse one-way clutch are provided adjacent to each other, and a slide sleeve is installed between the forward one-way clutch, the reverse one-way clutch, and the connecting drum. Since either one is selectively fitted to the connecting drum using a slide sleeve, it is possible to automatically avoid a braking phenomenon when turning during forward and backward movement of the four-wheel drive. Furthermore, when decelerating when moving forward with four-wheel drive,
Since the engine brake acts on all four wheels, the engine brake acts effectively. Furthermore, the simple construction of the connecting drum, the forward and reverse one-way clutches, and the slide sleeve allows for a compact structure and reliable operation.

[Brief explanation of drawings]

FIG. 1 is a skeleton diagram schematically showing an embodiment of a four-wheel drive vehicle according to the present invention, and FIG. 2 is a configuration diagram showing the configuration and control system of the main parts. 1... Drive device, 2... Rear wheel differential device, 4...
Rear wheel, 5... Transfer device, 8... Reverse one-way clutch, 9... Forward one-way clutch, 13... Front wheel, 14... Gear shaft, 15...
Drive shaft, 16... Connection drum, 17... Slide sleeve, 20... Actuator, 23...
... Solenoid valve, 26 ... Reverse switch, 2
7...4WD switch, 31...Accelerator switch, 32...Vehicle speed switch.

Claims (1)

[Claims] 1. Direct transmission to one of the front and rear wheels through a differential device, and transmission to the other through a transfer device consisting of a two- or four-wheel switching clutch and a direction changing gear. In a two- or four-wheel drive device in which a gear shaft of the direction conversion gear and a drive shaft for driving the other of the front and rear wheels are arranged on the same axis, a connecting drum is integrally connected to the gear shaft. a forward one-way clutch and a reverse one-way clutch are provided adjacent to each other on the drive shaft, and a slide sleeve is mounted between the forward one-way clutch, the reverse one-way clutch and the connecting drum, A four-wheel drive vehicle characterized in that one of the forward one-way clutch and the reverse one-way clutch is selectively fitted to the coupling drum by the slide sleeve.