JP2706092B2 - Four-wheel drive vehicles - Google Patents

Description

The present invention relates to a four-wheel drive vehicle in which a differential mechanism of a viscous coupling and a transfer clutch such as a dog clutch are arranged in series in a power transmission system between front and rear wheels. For details,
A manual operation mechanism for holding the transfer clutch in a disengaged state by manual operation of an operator disposed at a position where it is difficult for the driver to visually recognize the outer wall of the case in which the transfer clutch is housed, and an operation state of the manual operation mechanism And a display for notifying the driver of the situation.

(Prior Art) In a four-wheel drive vehicle, the front and rear wheels are generally connected via a transfer clutch such as a hydraulic clutch, and the transfer clutch controls the drive force distribution ratio between the front and rear wheels. Conventionally, as a four-wheel drive vehicle of this type, as described in Japanese Utility Model Laid-Open No. 59-188731,
A clutch that can connect and disconnect the transmission system between the front and rear wheels and a viscous coupling having a differential function are interposed in series, and the clutch is disconnected during braking to maintain stability during braking. Things are known.

By the way, in the four-wheel drive vehicle as described above, it is desirable to shut off the power transmission system of the front and rear wheels during traction or inspection of the drive system at the time of failure, and the transfer clutch is manually disengaged. Is provided with a manual operation mechanism that can be held at the same time. Since such a manual operation mechanism is not operated in normal time and operability is not considered, the operation element is arranged near the transfer clutch such as an outer wall of a case housing the transfer clutch, thereby simplifying the structure. .

(Problems to be Solved by the Invention) However, in the four-wheel drive vehicle having the above-described manual operation mechanism of the transfer clutch, the operator of the manual operation mechanism is difficult to be visually recognized by the driver such as the outer wall of the case. The driver may forget to return the manual operation mechanism when performing normal driving after operating the manual operation mechanism to disengage the transfer clutch during towing, etc. There was a problem.

The present invention has been made in view of the above problems, and provides a four-wheel drive vehicle that informs a driver of an operation state of a manual operation mechanism in which an operator is arranged at a position where it is difficult for the driver to visually recognize the driver, It is an object of the present invention to enable a driver to quickly perform a return operation of a manual operation mechanism.

(Means for Solving the Problems) A four-wheel drive vehicle according to the present invention includes a clutch state detecting means for detecting a disengaged state of a transfer clutch, a state of the transfer clutch detected by the clutch state detecting means and a command signal. The operation state of the manual operation means is determined based on whether or not the command content matches.If the transfer clutch is in the disengaged state despite the command signal instructing connection, the transfer clutch is disengaged by the manual operation means. Operating state detecting means for determining that the state is maintained.

(Operation) According to the four-wheel drive vehicle of the present invention, the two-wheel drive state can be maintained by holding the transfer clutch in the disengaged state with a simple structure of the manual operation mechanism, and traction and the like can be easily performed. Then, the operation state of the manual operation mechanism is detected, and when the transfer clutch is disengaged by the manual operation mechanism, this is notified to the driver by a lamp or sound. Therefore, even during normal traveling after towing or the like, the operation state of the manual operation mechanism can be confirmed, and the returning operation is not forgotten.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 show a four-wheel drive vehicle according to an embodiment of the present invention. FIG. 1 is a schematic diagram of a power transmission system, and FIG. 2 (a) is a partially enlarged cross-sectional view of a main mechanism. , FIG. 2 (b)
3A is a partially enlarged sectional view of a main mechanism portion in a different differential state, and FIG. 3B is a III view of FIG. 3A. FIG. 4 is a flowchart of the control process.

In FIG. 1, reference numeral 11 denotes a power unit in which an engine and a transmission are integrally assembled, and a bevel gear 12a and a spur gear 13a are fixed to an output shaft 11a of the power unit 11. This power unit 11 has a bevel gear 12
a is a bevel gear 12b fixed to the front end of the propeller shaft 14
And the spur gear 13a meshes with the front differential 15 and the driven gear 13b, and the output shaft 11a
And the front differential 15 so as to be able to transmit power. The front differential 15 is connected to the left and right front wheels 16F via axles 17F, respectively, and connects the left and right front wheels 16F to the power unit 11 while allowing a differential. The propeller shaft 14 has a rear end connected to a viscous coupling 19 functioning as a center differential and a rear differential via a dog clutch 18 serving as a two-wheel / four-wheel switching transfer clutch. These dog clutch 18 and viscous coupling
19 is attached to the rear of the propeller shaft 14, and the viscous coupling 19 is attached to each of the left and right rear wheels 16R with an axle 1
It is linked via 7R.

The dog clutch 18 is shown in FIGS. 2 (a) and 2 (b) and FIG.
As shown in FIGS. 1A and 1B, an input shaft 21 connected to a propeller shaft 14 and an output shaft 22 connected to a viscous coupling 19 are coaxially and rotatably supported in a case 20. The input shaft 21 has a hub 23 by spline coupling on the outer periphery of the end facing the output shaft 22, and the output shaft 22 has a piece 25 via the torsion damper 24 on the outer periphery of the end facing the input shaft 21. Dog teeth 23a, 25a are formed on opposite end surfaces of the hub 23 and the piece 25, respectively, so as to be able to engage and disengage with each other. A groove 21a is formed on the input shaft 21 at a position corresponding to the end of the hub 23, and the hub 21 is provided in the groove 21a.
A plurality of steel balls 26a contacting the ends of the steel balls 26a are provided, and a holder 21b is provided adjacent to the groove 21a, and the plurality of steel balls 26b are supported by the holder 21b. Outside the steel ball 2
The sleeve 27 is loosely fitted so as to be axially movable by engaging with the sleeves 6a and 26b. The sleeve 27 is driven by the shift fork 28 in the axial direction with the claw 28a at the tip of the shift fork 28 engaged with the outer peripheral surface, and guides the steel ball 26a to restrict the movement of the hub 23.

The shift fork 28 has a cylindrical tubular portion 28b at the base end, and the above-described claw portion 28a extends integrally from the outer periphery of the tubular portion 28b,
The cylindrical portion 28b is fixed to the shift shaft 29. Also,
A projection 28c is provided on the outer peripheral surface of the cylindrical portion 28b of the shift fork 28.
Are formed so as to be engageable with the stroke switch 30, and an engagement protrusion 28d which engages with the manual switching mechanism 31 is formed integrally. The shift shaft 29 is connected to the input / output shaft 2 described above.
1, 22 are supported in the direction of axial movement and one end is engaged with the electromagnetic actuator 32 to
The return spring 33 is compressed in the axial direction between the end surface of the cylindrical portion 28b of the shift fork 28 and the inner wall of the case 20 on the other end side, and opposes the electromagnetic actuator 32 by the spring 33. Axial urging force acts. The stroke switch 30 is connected to the controller 34, and the detector is engaged with the projection 28c of the shift fork 28 to detect the operating position of the shift fork 28. As shown in FIG. 3 (a), the stroke switch 30 is operated when the shift fork 28 is operated to the left position in the figure, that is, when the shift fork 28 is at a position where the dog clutch 18 is disengaged as described later. The protruding piece of shift fork 28
28c is engaged and the built-in switch is turned on. The electromagnetic actuator 32 has a plunger that engages with the shift shaft 29 and a solenoid that biases the plunger. The solenoid is connected to the controller 34. As shown in FIG. 1, the controller 34 is connected to the input system in addition to the stroke switch 30 described above, various sensors 35 for detecting a running state of the vehicle, and a selection switch 36 for two-wheel / four-wheel manual switching. A display 37 is connected to the output system together with the electromagnetic actuator 32, and the electromagnetic actuator 32 and the display are connected based on the output signals of the sensors 30, 35 and the selection switch 36.
Controls the operation of 37. Display 37. It is arranged in the vicinity of the driver's seat in the vehicle cabin, etc., and notifies the driver of the disengagement state of the dog clutch 18 by a sound such as a buzzer or lighting of a lamp when the dog clutch 18 is disengaged in response to a signal output by the controller 34.

The manual switching mechanism 31 is provided in the state shown in FIGS.
As shown in FIGS. 7A and 7B, a column 38 penetrating through the case 20 and rotatably provided in the case 20 is provided. The pressing element 38a engaging with the projection 28d is formed eccentrically,
A hexagonal column-shaped operation portion 38b is formed on an end surface of the column 38 outside the case 20. The column 38 is manually operated by a wrench or the like fitted to the operation portion 38b and rotated, and the pressing element 38a presses the shift fork 28 via the protrusion 28d, and the shift fork 28 is shown in FIG. The dog clutch 18 is held in the disengaged state. Further, marks 2 , 4 engraved on the outer wall surface of the case 20 as shown in FIGS. 2 (b) and 3 (b) are provided on the end surface of the column 38 outside the case 20.
Colored mark 39 at the position corresponding to
The notches 40a and 40b are formed, and the mark 39 indicates the mark 4 or 2 in accordance with the turning position of the column 38, that is, the connection and disconnection of the dog clutch 18, and the notches 40a and 40b have the outer wall of the case 20. Is fitted with a holder plate 41 detachably attached with bolts. This holder plate
41 fits into the notches 40a, 40b to hold the column 38 in that position.

In this four-wheel drive vehicle, the column of the manual switching mechanism 31
2A and 2B, when the solenoid of the electromagnetic actuator 32 is not energized, the shift fork 28 is urged by the spring 33 to be integrated with the shift fork 28. An actuating sleeve 27 holds the steel ball 26a in the groove 21a, the hub 23 and the piece 25
The dog teeth 23a and 25a mesh with each other to keep the dog clutch 18 in the connected state, but when the solenoid of the electromagnetic actuator 32 is energized, the shift fork 28
33 is pressed by the electromagnetic actuator 32 against the elastic force of 33, the sleeve 27 is displaced together with the shift fork 28, the steel ball 26a jumps out of the groove 21a, and the dog clutch
In the case of 18, the dog teeth 23a and 25a are disengaged and disengaged. In this four-wheel drive vehicle, when the dog clutch 18 is held in the disengaged state by towing or inspection, the driver or the operator operates the column 38 of the manual switching mechanism 31 by using the operating unit 38b.
Is rotated by a tool such as a wrench fitted to
The shift fork 28 is pressed against the spring 33 to the left end position in the figure by a, and the column 38 is fixed by the plate 41. For this reason, the dog clutch 18 is
Regardless of the operation of the rear wheel 16R
Is released from the front wheel 16F and the engine 11, and traction and the like can be easily performed.

On the other hand, in the four-wheel drive vehicle, the running state of the vehicle is detected by various sensors 35 during normal running, and the controller 34 controls the energization of the solenoid of the electromagnetic actuator 32 according to the running state, and the dog clutch 18 Automatic control of connection and disconnection, that is, switching between two-wheel drive and four-wheel drive. At this time, the stroke switch 30 is
Operation (position) of dog clutch 18 (connection, disconnection)
Controller 34 detects that the stroke switch 30
The feedback control of the electromagnetic actuator 32 is performed based on the detection signal. Then, the controller 34 controls the stroke switch 30
The operation state of the manual switching mechanism 31 is determined based on whether or not the output signal of the electromagnetic switch 32 corresponds to whether or not the solenoid of the electromagnetic actuator 32 is energized. The determination of the operation state is performed by a series of processes in the flowchart of FIG. First, step
In P1, the counter T functioning as a timer is reset, and then in step P2, it is determined whether or not the stroke switch 30 is ON, that is, whether or not the stroke switch 30 is in contact with the shift fork 28G detector. In this step P2, if it is determined that the stroke switch 30 is not ON, the processing from step P1 is repeatedly executed again.
If it is determined that the
It is determined whether or not the 32 solenoids are energized. Then, in step P3, if it is determined that the solenoid of the electromagnetic actuator 32 is energized, the process from step P1 is performed.If it is determined that the solenoid of the electromagnetic actuator 32 is not energized, the counter is determined in step P4. Add 1 to T. Subsequently, in step P5, it is determined whether or not the count value of the counter T is equal to or greater than the set value N. If the count value T does not reach the set value N, the processing from step P2 is executed again, and the count value T is set. If the value is equal to or more than the value N, the driver is notified that the manual switching mechanism 31 is operated by turning on a lamp or the like. That is, even though the solenoid of the electromagnetic actuator 32 is not energized, the stroke switch 30
When the state of outputting the ON signal continues for a predetermined time, the dog clutch 18 is determined to be disengaged by the manual switching mechanism 31, and the driver is notified by a lamp or the like. Measures after the return operation and the like can be easily performed, and the return operation is not forgotten. In addition, by performing the above-described flowchart, abnormality diagnosis can be performed, and the reliability thereof can be improved.

(Effects of the Invention) As described above, according to the four-wheel drive vehicle of the present invention, a manual switching mechanism having a simple structure is provided so that the transfer clutch can be maintained in the disengaged state by manual operation of the mechanism. In addition, since the operation state of the manual switching mechanism is detected and notified to the driver, it is possible to easily perform towing or the like in the two-wheel drive state and to prevent forgetting to return the manual switching mechanism. can get.

[Brief description of the drawings]

1 to 4 show a four-wheel drive vehicle according to an embodiment of the present invention. FIG. 1 is a schematic diagram of a power transmission system, FIG. 2 (a) is a cross-sectional view of a main mechanism, FIG. FIG. 2 (b) is a view taken in the direction of the arrow II in FIG. 2 (a), FIG. 3 (a) is a sectional view of the main mechanism, FIG. 3 (b) is a view taken in the direction of the arrow III in FIG. FIG. 4 is a flowchart of the control process. 11 Power unit 16F Front wheel, 16R Rear wheel 18 Dog clutch (transfer clutch) 19 Viscous coupling (Canda differential) 30 Stroke switch 31 Manual switching mechanism 32 Electromagnetic actuator 34 … Controller 37 …… Display

Claims (1)

(57) [Claims] 1. A power transmission system for connecting a front wheel and a rear wheel with a transfer clutch capable of connecting / disconnecting the power transmission system and a center differential allowing a differential,
A controller for connecting / disconnecting the transfer clutch according to a command signal; and manual operating means capable of holding the transfer clutch in a disengaged state by manual operation of an operator mechanically connected to the transfer clutch. In a four-wheel drive vehicle, a clutch state detecting means for detecting a disengaged state of the transfer clutch, and whether or not the state of the transfer clutch detected by the clutch state detecting means matches the command content of the command signal. In the operation state of the manual operation means is determined,
If the transfer clutch is in the disengaged state despite the command signal instructs connection, an operation state detecting means for determining that the transfer clutch is held in the disengaged state by the manual operation means; A four-wheel drive vehicle characterized by comprising: