JPH0632437Y2 - Front drive switching device for all-wheel drive system of vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an all-wheel drive device for a vehicle, and more particularly to a front drive used when selecting a front and rear all-wheel drive or a rear-only drive. Switching device.

<Prior Art> Conventionally, a device as shown in FIG. 3 has been known as a device for driving all wheels in a vehicle such as a truck.

That is, a transfer 5 as a power distribution device is arranged between the final reduction gear 2 connected to the front wheels 1 by a drive shaft (not shown) and the final reduction gear 4 similarly connected to the rear wheels 3 by a drive shaft (not shown). Installed, the output of the engine 6 is the transmission 7 and the transfer 5
It is adapted to be transmitted to each of the front wheel and rear wheel final reduction gears 2, 4 via.

In such an all-wheel drive device, it is possible to switch between front and rear all-wheel drive and rear-only drive,
The transfer 5 is equipped with ON / OFF switching means for the front drive.

Here, an example of the transfer is shown in FIG.

In the figure, the transfer is composed of six gears 8 to 13, four shafts 14 to 17, and two clutch gears (sleeve) 1
It consists of 8,19 and case 20, cover 21, bearing 22, etc., and two main gears 8 on the main shaft 14,
9 is idling through the bearing 22. A clutch gear 18 for switching between low speed and high speed is provided between the two main gears 8 and 9 and is spline-fitted to the main shaft 14 so that it can slide back and forth on the shaft 14.

Three gears 10 to 12 are spline-fitted to the idler shaft 15, and the reduction gears 10 and 11 mesh with the main gears 8 and 9, respectively. The idler gear 12 meshes with the output gear 13. Output shaft
A front drive shaft 17 is provided in front of 16, and a clutch gear 19 is provided between the two.

The output from the trasmission enters the main shaft 14, and the clutch gear 18, the main gear 8 or 9 (the side where the clutch gear 18 meshes), the reduction gear 10 or 1
1, the idler shaft 15, the idler gear 12, and the output shaft 16 are transmitted. Output is transmitted from the output shaft 16 to the rear axle.

The front drive shaft 17 normally idles, but when the clutch gear 19 (front drive ON / OFF sleeve) is moved forward and meshed with the front drive shaft 17, it becomes integral with the output shaft 16 and the transmission mission. The output from is transmitted to the output shaft 16 and the front drive shaft 17 at the same time as the above-described route, and all-wheel drive becomes possible.

And the front drive ON / OFF sleeve 19
Is operated by an air shift mechanism using an air cylinder 23 as shown in FIG.

That is, when the front drive ON / OFF switch (manual switch) 24 is turned ON, the magnetic valve 25 opens, and air flows from the air reservoir 26 to the air cylinder 23,
Push the piston 23a of this.

Therefore, the shift fork shaft 27 connected to the piston 23a is pulled, the shift fork 28 slides the front drive ON / OFF sleeve 19 of the transfer, and the front drive is turned ON.

Next, when the switch 24 is turned off, the magnetic valve 25 is closed and the air supply from the air reservoir 26 is cut off. At the same time, the air in the air cylinder is discharged from the exhaust port of the magnetic valve 25 to the atmosphere. Therefore, the return spring 23b extends and returns the piston 23a,
Shift fork shaft connected to the piston 23a
27 is returned, the sleeve 19 connected to the shift fork 28 is returned, and the front drive is turned off.

<Problems to be Solved by the Invention> However, in such a conventional all-wheel drive device, ON / OFF switching operation of the front drive is possible even while the vehicle is running, and the shift fork is operated when the vehicle is running.
Transfer front drive ON / OF by 28
Sliding of the F-sleeve 19 may cause noise and spline breakage due to biting of the spline.

In view of the conventional situation, the present invention has an object to solve the above-mentioned conventional problems by configuring the ON / OFF switching operation of the front drive only when the vehicle is stopped.

<Means for Solving Problems> Therefore, in the present invention, the front and rear all-wheel drive and the rear-only drive are turned ON / O of the front drive.
In a all-wheel drive device for a vehicle that can be selected by FF switching, a first relay that is closed when the vehicle speed is zero and is opened when the vehicle is traveling based on a switching operation switch and a vehicle speed detection signal output from the vehicle speed detection switch. A front drive ON / OFF switching means by switching the switching operation switch only when the first relay switch is ON while the vehicle is stopped based on the signal from the vehicle speed detection switch. An electric circuit for driving front drive ON / OFF switching means configured to be driven, wherein coils of the vehicle speed detection switch and the first relay switch are connected in series to a power supply, and the vehicle speed detection switch is closed at zero vehicle speed. When it is turned on, the coil is excited,
When the contact of the first relay switch is closed and the vehicle speed detection switch detects vehicle running and is turned off, the coil is de-excited and the contact is opened, and the power source is the contact of the second relay switch. Is connected to the ON / OFF switching means of the front drive via one terminal of the coil of the second relay switch is connected to the contact of the first relay switch via the switching operation switch, and Is grounded via a contact of a third relay switch, and the coil of the third relay switch is connected to an OFF contact provided for the changeover operation switch,
When the coil is normally closed and the coil is excited, the contact is opened. The second relay switch is always opened, and when the coil is excited, the contact is closed and once the When the coil is excited and the contact is closed, and the coil is energized through the contact, the front drive ON / OFF switching means is configured to maintain the contact in the closed state and the ON state. A front drive switching device in an all-wheel drive system for a vehicle, characterized by comprising an electric circuit for use.

<Operation> In such a configuration, when the vehicle speed detection switch detects zero vehicle speed (vehicle speed stop) and the first relay switch is turned ON, the front drive ON / OFF is switched when the switching operation switch is turned ON / OFF. Done.
Further, when the vehicle is run in this state, the vehicle speed detection switch detects the vehicle running state, so the first relay switch is turned off and the changeover operation switch is turned on or OF.
Even if F is applied, the front drive ON / OFF switching means is not driven, and the drive state is maintained.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show the front and rear all-wheel drive and the rear-only drive with the front drive ON / O.
1 shows an embodiment of an electric circuit for driving a front drive ON / OFF switching means in an all-wheel drive system for a vehicle that can be selected by FF switching.

In the figure, 29 is the front drive ON / OF of the transfer.
An air cylinder incorporating a piston 29a connected to a shift fork shaft 30 for operating the F sleeve, 31 is an air reservoir for supplying air to the air cylinder 29 via a magnetic valve 32, and 33 is a front drive ON / O.
It is an FF switch (manual switch).

The circuit is closed when the vehicle speed is zero based on a vehicle speed detection signal output from the front drive ON / OFF switch 33 as a changeover operation switch and a vehicle speed detection switch 35 as a vehicle speed detection means, and when the vehicle is traveling. A first relay switch 36 that is opened, and switches the front drive ON / OFF switch 33 only when the relay switch is ON while the vehicle is stopped based on a signal from the vehicle speed detection switch 35. The magnetic valve 32 as a switching means can be driven by.

Here, the vehicle speed detection switch 35 and the coil 36a of the relay switch 36 are connected in series to the power supply 34. When the vehicle speed detection switch 35 is closed at the vehicle speed 0 and turned on, the coil 36a is turned on.
Is excited, the contact 36b of the relay switch 36 is closed,
When the vehicle speed detection switch 35 detects vehicle running and is turned off, the coil 36a is de-excited and the contact 36b is opened. On the other hand, the power source 34 is the contact 37b of the second relay switch 37.
Is connected to the magnetic valve 32 via. One terminal of the coil 37a of the relay switch 37 is connected to the contact 36b of the relay switch 36 via the front drive ON / OFF switch 33, and the other terminal is connected to the contact 38b of the third relay switch 38. It is grounded.
The coil 38a of the relay switch 38 is an OF provided for the front drive ON / OFF switch 33.
It is connected to the F contact. And the relay switch 37
Is normally opened, and when the coil 37a is excited, the contact 37
b is closed, the relay switch 38 is normally closed, and when the coil 38a is excited, the contact 38b is opened.

Further, the relay switch 37 keeps the contact 37b closed and self-maintained in the ON state when the coil 37a is excited and the contact 37b is closed once, and the coil 37a is energized via the contact 37b. To do.

In this case, the contact 37b of the relay switch 37 and the magnetic valve 32 are connected to one terminal of the coil 37a, and a diode is interposed here.

The operation of the drive electric circuit of the ON / OFF switching means of the front drive having such a configuration will be described.

First, in FIG. 1, since the vehicle speed is 0 when the vehicle is stopped, the vehicle speed detection switch 35 is closed and turned on as shown by the solid line.
Then, the coil 36a of the relay switch 36 is excited, and the contact 36b is closed as shown by the solid line. When the front drive ON / OFF switch 33 is turned ON in this state,
Since the contact 38b of the relay switch 38 is closed and the coil 37a of the relay switch 37 is excited, the contact 37b of the relay switch 37 is closed. As a result, the magnetic valve 32 is energized to be turned on and opened. Therefore, the air from the air reservoir 31 is transferred to the air cylinder 29.
And push the piston 29a of this. Therefore, the piston
The shift fork shaft 30 connected to 29a is pushed,
The shift fork slides the front drive ON / OFF sleeve of the transfer, turning the front drive ON.

Also, in FIG. 2, when the vehicle is stopped, the front drive is turned on.
・ When the OFF switch 33 is turned OFF, the relay switch
Since the coil 38a of 38 is excited and the contact 38b is opened, the coil 37a of the relay switch 37 is non-excited and the contact 37b is opened.
b is opened. Therefore, the magnetic valve 32 is OF
At F, the valve is closed and the air supply from the air reservoir 31 is cut off. At the same time, the air in the air cylinder 29 is discharged from the exhaust port of the magnetic valve 32 to the atmosphere.

Therefore, the return spring 29b extends and the piston 29a
Is returned, the shift fork shaft 30 connected to the piston 29a is returned, the sleeve connected to the shift fork is returned, and the front drive is turned off.

On the other hand, as described above, front drive ON / OFF
Switch 33 ON / OFF, front drive ON
-When the vehicle is driven in the OFF state, the ON / OFF state of the front drive is maintained as it is and the ON / OFF switching of the front drive cannot be performed.

That is, in FIG. 1, when the vehicle is run with the front drive turned on, the vehicle speed detection switch 35 opens as shown by the dotted line, the coil 36a of the relay switch 36 becomes non-excited, and the contact 36b shows by the dotted line. It is opened like this. However, when the vehicle is stopped, as described above, the relay switch 37
The coil 37a is excited and the contact 37b is closed, so that the coil 37a is connected via the contact 37b and the diode 39.
Since the contact 37b is kept closed and the relay switch 37 is kept in the ON state by itself, the magnetic valve 32 is kept in the ON state and the front drive is switched to OFF. I can't.

Further, in FIG. 2, when the vehicle is run with the front drive turned off, the vehicle speed detection switch 35 is opened, the coil 36a of the relay switch 36 is de-energized, and the contact 36b is opened. However, when the vehicle is stopped, the coil 38a of the relay switch 38 is in an excited state and the contact 38b of the relay switch 38 is opened, so that the coil 37a of the relay switch 37 is not excited and the contact 37b is opened. Therefore, the magnetic valve 32 is held in the OFF state and the front drive cannot be switched to the ON state.

According to this configuration, as described above, since the ON / OFF switching operation of the front drive can be performed only when the vehicle is stopped, the ON / OFF switching operation is impossible in the traveling state of the vehicle. In this state, the shift fork does not slide the front drive ON / OFF sleeve of the transfer, and there is no risk of abnormal noise or spline damage due to biting of the spline.

<Effects of Device> As described above, according to the present invention, the ON / OFF switching operation of the front drive can be performed only when the vehicle is stopped. The inconvenience given to the ON / OFF switching means can be eliminated, and in particular, according to the present invention, the switching operation switch, the vehicle speed detection switch, and the first to third relay switches are used to drive the front drive ON / OFF switching means. Since the circuit is configured, it is not necessary to provide a complicated and expensive control device, and it can be provided to the market at low cost, which is a great practical effect.

[Brief description of drawings]

1 and 2 respectively show an electric circuit diagram for driving the ON / OFF switching means of the front drive showing an embodiment of the front drive switching device in the all-wheel drive system for a vehicle according to the present invention, and FIG. FIG. 4 is an overall configuration diagram of a wheel drive device, FIG. 4 is a sectional view of a transfer in the same device, and FIG. 29 ... Air cylinder, 30 ... Shift fork shaft, 31 ...
Air reservoir, 32 ... Magnetic valve, 33 ... Front drive ON / OFF switch, 34 ... Power supply, 35 ... Vehicle speed detection switch, 36, 37, 38 ... Relay switch, 39 ... Diode

Claims (1)

[Scope of utility model registration request] 1. A all-wheel drive system for a vehicle, in which front and rear all-wheel drive and rear-only drive can be selected by switching the front drive ON / OFF, and output from a switching operation switch and a vehicle speed detection switch. A first relay switch that is closed when the vehicle speed is zero based on a vehicle speed detection signal and is opened when the vehicle is running, and the first relay switch is opened when the vehicle is stopped based on a signal from the vehicle speed detection switch. An electric circuit for driving the front drive ON / OFF switching means configured to drive the ON / OFF switching means of the front drive only by switching the switching operation switch when the relay switch is turned ON. The detection switch and the coil of the first relay switch are connected, and the vehicle speed detection switch closes at zero vehicle speed and turns on. Serving as the coil is excited,
When the contact of the first relay switch is closed and the vehicle speed detection switch detects vehicle running and is turned off, the coil is de-excited and the contact is opened, and the power source is the contact of the second relay switch. Is connected to the ON / OFF switching means of the front drive via one terminal of the coil of the second relay switch is connected to the contact of the first relay switch via the switching operation switch, and Is grounded via a contact of a third relay switch, and the coil of the third relay switch is connected to an OFF contact provided for the changeover operation switch,
When the coil is normally closed and the coil is excited, the contact is opened. The second relay switch is always opened, and when the coil is excited, the contact is closed and once the When the coil is excited and the contact is closed, and the coil is energized through the contact, the front drive ON / OFF switching means is configured to maintain the contact in the closed state and the ON state. A front drive switching device for an all-wheel drive system of a vehicle, comprising an electric circuit for use in a vehicle.