JPH0239872Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a part-time 4-wheel drive system that operates in two-wheel drive (2WD) using one of the front and rear wheels or in four-wheel drive (4WD) using both the front and rear wheels. In the drive vehicle, 2WD or
Regarding the switching device that switches to each driving mode of 4WD,
In particular, it relates to a system using a diaphragm actuator that uses negative pressure.

[Conventional technology]

As a switching device for this type of four-wheel drive vehicle, a system using a diaphragm actuator that uses the engine's intake manifold negative pressure has been proposed, for example, as shown in Japanese Utility Model Publication No. 48-8821.
In this prior art, in particular, a specific shift position of the transmission is electrically detected and automatically shifted. On the other hand, when switching is to be performed by manual operation of a button switch, the applicant of the present invention has proposed that the switching be performed using a diaphragm actuator using negative pressure as in the prior art described above.

[The problem that the idea aims to solve]

Incidentally, in all of the above systems, the actuator switches by introducing negative pressure into the negative pressure chamber on one side of the diaphragm, and thereafter continues to introduce negative pressure to maintain the switched state. Therefore, the diaphragm lacks durability, and there are problems such as problems caused by the mixture of negative pressure and gasoline in the intake manifold.

In view of these problems in the conventional technology, the present invention is based on a diaphragm actuator that uses negative pressure.The negative pressure acts on the diaphragm only when switching to each driving mode, thereby reducing the durability of the diaphragm, etc. It is an object of the present invention to provide a switching device for a four-wheel drive vehicle that is designed to improve performance and reliability of the entire device.

[Means to solve the problem]

For this purpose, the configuration of the present invention is such that the output shaft side of the transmission is configured to transmit power directly to one of the front and rear wheels, and to the other wheel through a transfer clutch, and the output shaft of the transmission is configured to transmit power to the other wheel through a transfer clutch. A shift rail from a diaphragm actuator is connected to the shift rail, and check ball means for positioning 2-wheel drive and 4-wheel drive is provided in the middle of the shift rail, and a first negative pressure chamber and a second negative pressure chamber are provided on both sides of the diaphragm of the actuator. a first solenoid valve that communicates with the first negative pressure chamber and a second solenoid valve that communicates with the second negative pressure chamber, and energizes the first and second solenoid valves. Connects to a 2-wheel drive and 4-wheel drive selector switch that selectively switches between
In a two-wheel drive/four-wheel drive switching device in which a confirmation switch that is turned on when the shift rail is in the four-wheel drive position is provided at the end of the shift rail, negative pressure is applied to the actuator after switching the changeover switch. One end side of the electric circuit of the first and second solenoid valves is connected to a power source, and the other end side of the first solenoid valve is connected to the first and second solenoid valves. the other end of the electrical circuit of the second solenoid valve via the second contact;
A relay is connected to the changeover switch and opens the second contact when the changeover switch is selected to the four-wheel drive side and the shift rail is positioned in the four-wheel drive position, and one end of the relay is connected to the power source. ,
The other end is connected to the confirmation switch, and a timer is provided to open the first contact after a predetermined time has elapsed since the changeover switch is selected to the two-wheel drive side and the shift rail is positioned at the two-wheel drive position. One end of the timer is connected to a power source, and the other end is connected to a normally closed third contact that is opened by the relay.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described based on the drawings.

In Fig. 1, a four-wheel drive vehicle to which the present invention is applied is based on a transverse transaxle type FF vehicle.An engine 1, a clutch 2, and a transmission 3 are located at the front of the vehicle body in the left-right direction. A front differential device 4 and a transfer device 5 are sequentially arranged from the transmission 3 to the rear of the vehicle body. And transmission 3, front differential device 4
The transfer device 5 includes a clutch housing 6, a transmission case 7, and an extension case 8.
It is installed inside the engine and forms a transaxle type.

The transmission 3 is configured to have a plurality of sets of shift gears 12 and a synchronizer 13 on an input shaft 10 and an output shaft 11 from the clutch 2 so as to obtain multiple gear stages, and the front differential device 4 has the above-mentioned output. The drive gear 14 of the shaft 11 meshes with the final gear 15, and the differential device 1 is attached to the final gear 15.
6 to the left and right front wheels 18 via an axle 17. In the transfer device 5, a transfer gear 19 that meshes with the final gear 15 is rotatably fitted on a transfer shaft 20, and a meshing type transfer clutch 21 is provided between the two, and the transfer shaft 20 is connected to a rear drive shaft 23 via a pair of bevel gears 22. The rear drive shaft 23 is further configured to transmit power to left and right rear wheels 27 via a propeller shaft 24, a rear differential device 25, and an axle 26.

In the transfer clutch 21, a sleeve 31 is spline-fitted to a hub 30 integral with the transfer shaft 20, and the sleeve 31 is moved and engaged by meshing with the spline portion 19a of the transfer gear 19. It is designed to connect the rings directly.

In FIG. 2, the transfer clutch 2
To explain the switching operation system 1, a shift rail 32 is arranged parallel to the transfer shaft 20, and a fork 3 fixed to the shift rail 32.
3 engages the sleeve 31 of the transfer clutch 21, and the shift rail 32 is connected via a scale lever 34 to a rod 37 integral with a diaphragm 36 of an actuator 35. The fork 33 on the shift rail 32 is as shown in the figure.
It has the function of a stopper that comes into contact with the transmission case 7 side at the 4WD position and restricts further movement, and similarly, the shift rail 32 is provided with a stopper 38 that restricts movement beyond the 2WD position. Furthermore, check ball means 39 are provided between the clutch housing 6 and the shift rail 32 for positioning and holding the shift rail 32 at each position.

The first and second negative pressure chambers 40a and 40b on both sides of the diaphragm 36 of the actuator 35 are connected to a passage 41.
The first and second solenoid valves 42 via a and 41b
A passage 43 from a negative pressure source such as an engine intake manifold communicates with the first and second solenoid valves 42a and 42b. When the first and second solenoid valves 42a and 42b are energized, they close the atmospheric side port and open the first and second negative pressure chambers 42a and 42b.
Negative pressure is introduced into a and 40b, and when the electricity is turned off, the atmospheric side port is opened and the first and second negative pressure chambers 40a and 40b are opened.
leaks into the atmosphere.

In addition, the first and second solenoid valves 42a and 42b
To explain the electrical control system, battery 4
A key switch 46 from 5 is connected to a changeover switch 48 via a first solenoid valve 42a for 2WD, a contact (first contact) 47' of a timer 47, and a second solenoid valve 42b for 4WD, and a relay 4.
Similarly, it is connected to the changeover switch 48 via a contact point (second contact point) 49' at No. 9. Furthermore, key switch 46
is grounded via the timer 47 and the other contact (third contact) 49'' of the relay 49, and is grounded via the relay 49 connected in parallel, the indicator lamp 50, and the 4WD confirmation switch 51 installed at the end of the shift rail 32. Here, when the timer 47 is excited by electricity, it turns off the contact 47' after a certain period of time, and
Contact 47' is turned ON when the power is not energized. relay 4
9 turns on contacts 49' and 49'' when not energized
When energized, contacts 49' and 49'' are turned OFF.
The confirmation switch 51 is turned on in the 4WD position.

Next, the operation of the switching device configured in this way will be explained. First, key switch 46
In the OFF state, timer 47 and relay 4
9 is de-energized, and each contact 47', 49'4
9″ is ON, and the first and second solenoid valves 4
2a and 42b can now be energized.

Therefore, if the changeover switch 48 is in 2WD when the key switch 46 is turned on, the first solenoid valve 42a is energized by the changeover switch 48 and the ON contact 47', and the first negative pressure chamber 40a of the actuator 35 is energized. Negative pressure is introduced into the Therefore, by moving the shift rail 32 to the right side in FIG. 2, the sleeve 31 of the transfer clutch 21 engages only with the hub 30, and the rear wheel side after the transfer shaft 20 is separated. It will be wheel drive.

At this time, the 4WD confirmation switch 51 is activated.
OFF, relay 49 is de-energized and contact 49'' is closed.
Since the ON state is maintained, the timer 47 is energized and after a certain period of time, the contact 47' is turned OFF to de-energize the first solenoid valve 42a. Then, the negative pressure in the first negative pressure chamber 40a of the actuator 35 leaks to the atmosphere and the diaphragm 36 becomes free, but from then on it is maintained at this 2WD position by the check ball means 39.

In the above state, when the changeover switch 48 is manually operated to switch to the 4WD side, the second solenoid valve 42b is energized by the ON contact 49'. Therefore, the second negative pressure chamber 4 of the actuator 35
By introducing negative pressure to 0b, the shift rail 3
2 moves to the left side in FIG. 2, and the sleeve 31 of the transfer clutch 21 meshes with the spline portion 19a, thereby directly connecting the front and rear wheels.
It will be wheel drive.

When the change to 4WD is completed in this way, the second
As shown in the figure, the confirmation switch 51 is turned on, the indicator lamp 50 is lit, and the relay 49 is energized, which turns off the contact 49' and de-energizes the second solenoid valve 42b. Therefore, as in the case of 2WD, the negative pressure in the second negative pressure chamber 40b leaks to the atmosphere, and from then on, the check ball means 39
It is held in 4WD position.

On the other hand, at this time, due to the energization of the relay 49, the contact 4
9″ is also turned off to de-energize timer 47,
The contact 47' returns to ON, allowing switching to 2WD.

In this way, when switching to 2WD or 4WD driving mode, negative pressure is temporarily introduced into the first negative pressure chamber 40a or second negative pressure chamber 40b of the actuator 35 by energizing the first solenoid valve 42a or the second solenoid valve 42b. After the switching, the introduction of negative pressure to the actuator 35 is cut off and the check ball means maintains each switching state.

Although one embodiment of the present invention has been described above, RR
It is equally applicable to base or longitudinal transaxle types. Further, it is also possible to apply automatic switching methods other than manual operation.

[Effect of idea]

As is clear from the above explanation, according to the present invention, when switching is performed using a diaphragm actuator method using negative pressure in a part-time four-wheel drive vehicle, negative pressure is used temporarily only during switching. The durability of the diaphragm is increased, and the contamination of gasoline in the intake manifold is significantly reduced, eliminating the associated problems. The structure is simple because only a timer, a relay, and contacts operated by them are added to the electrical control system.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram showing an example of a four-wheel drive vehicle to which the present invention is applied, and FIG. 2 is a configuration diagram showing an embodiment of the device according to the present invention. 3...Transmission, 4...Front differential device, 5...
...transfer device, 21...transfer clutch, 25...rear differential device, 32...shift rail, 35...actuator, 40a, 40b
...First and second negative pressure chambers, 41a, 41b...Passage, 42a, 42b...First and second solenoid valves, 47...Timer, 47'...First contact, 48
...Selector switch, 49...Relay, 49', 4
9″...Second and third contacts, 51...Confirmation switch.

Claims (1)

[Claims for Utility Model Registration] The output shaft of the transmission is configured to transmit power directly to one of the front and rear wheels, and to the other through a transfer clutch, and a diaphragm is installed in the sleeve of the transfer clutch. The shift rail from the actuator is connected, and check ball means for positioning 2-wheel drive and 4-wheel drive is provided in the middle of the shift rail, and a first negative pressure chamber and a second negative pressure chamber are provided on both sides of the diaphragm of the actuator. and a first solenoid valve that communicates with the first negative pressure chamber and a second solenoid valve that communicates with the second negative pressure chamber, and selects energization of the first and second solenoid valves. Switching between 2-wheel drive and 4-wheel drive by installing a confirmation switch at the end of the shift rail that connects to the 2-wheel drive and 4-wheel drive changeover switch and turns on when the shift rail is in the 4-wheel drive position. In the device, after switching the changeover switch, the first and second contacts, which are normally closed contacts that cut off the introduction of negative pressure to the actuator, are connected to one end side of the electric circuit of the first and second solenoid valves. connected to a power source, the other end of the first solenoid valve is connected to the changeover switch via a first contact, and the other end of the electric circuit of the second solenoid valve is connected to the changeover switch via a second contact; is selected to the 4-wheel drive side and the shift rail is positioned at the 4-wheel drive position, a relay is provided that opens the second contact, one end of the relay is connected to the power source, and the other end is connected to the confirmation switch. , providing a timer that opens the first contact after a predetermined time has elapsed since the changeover switch is selected to the two-wheel drive side and the shift rail is positioned at the two-wheel drive position, and one end of the timer is connected to a power source; A switching device for a four-wheel drive vehicle, characterized in that a normally closed third contact opened by the relay is connected to the other end of the switch.