JPH01114531A - Drive mode selection controller for four-wheel-drive vehicle - Google Patents

Abstract

PURPOSE:To alarm a driver for the selection operation in the prohibited drive mode by installing a drive mode selecting mechanism, actuator, operating means and a control means. CONSTITUTION:When an operating means 65 (transfer selection operating device) is operated so that the selection to the allowable drive mode is performed, a control means 64 operation-controls an actuator (motor) 32, generating an operation receiving sound. When the operating means 65 is erroneously operated so that the selection to the prohibited drive mode is performed, the control means 64 generates an erroneous operation sound, and informs a driver of anomaly. Therefore, the driver is protected from being informed of the operation in erroneous drive mode.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is capable of switching the drive state of a vehicle between a two-wheel drive state and a four-wheel drive state, and locks the center differential when in the four-wheel drive state. The present invention relates to a drive mode switching control device for a four-wheel drive vehicle that can switch to a free state.

(Prior Art) Conventionally, so-called part-time four-wheel drive vehicles in which the driving state of the vehicle can be switched between two-wheel drive state and four-wheel drive state are known, for example, as shown in Japanese Utility Model Publication No. 61-9791. The system is equipped with a fluid actuator that drives an operating member for switching to a two-wheel drive state or a four-wheel drive state, and a solenoid valve that operates the actuator. When the vehicle speed is high, the system is in two-wheel drive mode, while at low vehicle speeds, it detects the switching state of the transmission mechanism that switches the engine's output rotation between a low speed state and a high speed state. There is a known vehicle that controls switching between a two-wheel drive state and a four-wheel drive state depending on the switching state of a manual selection switch operated by a driver.

Additionally, in the past, a transfer device having a center differential was provided to change the driving state of the vehicle between two-wheel drive and four-wheel drive.
Part-time four-wheel drive vehicles are also known that are capable of switching to a wheel drive state and, when in a four-wheel drive state, can switch the center differential between a locked state and a free state. For 4-wheel drive vehicles, there are three drive modes: 2-wheel drive mode, 4-wheel drive mode with center differential free, and 4-wheel drive mode with center differential lock, depending on the switching position of the drive mode switching mechanism attached to the center differential. can be set.

In a four-wheel drive vehicle having such a drive mode switching mechanism, if the drive mode switching mechanism is configured to be electrically controlled as in the conventional example, the switching between the drive modes can be controlled. Switching can be done easily and quickly.

(Problems to be Solved by the Invention) By the way, when the drive mode switching mechanism is electrically controlled, it is difficult to switch between the two-wheel drive state and the four-wheel drive state, and between the locked and free states of the center differential. It is common to switch between the three drive modes by using corresponding changeover switches, but among the three drive modes mentioned above, the center differential lock When changing from 4-wheel drive mode to 2-wheel drive mode, the driving force of the idle wheel is lost, causing a sudden drop in traction.
As a result, the driving conditions of the vehicle suddenly change and the vehicle's driving stability cannot be maintained at a high level, so even if the driver switches the drive mode from 4-wheel drive mode with center differential lock to 2-wheel drive mode. However, this is not accepted and is prohibited.

However, since the operating system operated by the driver has selection positions corresponding to each drive mode,
If the driver performs the above operation, there is a risk that there will be a mismatch between the actual drive mode and the selected position of the operating system, and the driver may misunderstand that the mode has been switched to two-wheel drive mode. There was a fear that he might give it away.

The present invention has been made in view of the above circumstances, and its purpose is to warn the driver and make him/her aware of this when the driver performs a switching operation that prohibits the change of the drive mode. An object of the present invention is to provide a drive mode switching υ control device for a four-wheel drive vehicle.

(Means for Solving the Problems) In order to solve the above object, the present invention changes the drive state of a transfer device having a center differential to a two-wheel drive state,
4 wheel drive/seta differential lock condition.

A drive mode switching mechanism that switches between four-wheel drive and a center differential free state, an actuator that switches the drive mode switching mechanism, an operating means that selects each of the drive modes, and an output signal from the operating means. The actuator controls the operation of the actuator, and if the drive mode newly selected by the operating means is one that allows switching from the current drive mode, it generates an operation acceptance sound. controlling the operation of the actuator based on the output signal;
A drive mode of a four-wheel drive vehicle is provided with a control means that, if the newly selected drive mode to which the switch is to be changed is prohibited, does not accept the switch and generates an erroneous operation sound to warn the drive mode of the four-wheel drive vehicle. Configure the switching control device.

(Function) According to the present invention having the above configuration, when the operating means is operated to change to a drive mode for which switching is allowed, the control means generates the operation acceptance sound and controls the actuator. On the other hand, if the operating means is erroneously operated to change to a drive mode for which switching is prohibited, the control means generates an erroneous operation sound to warn the driver.
It is possible to prevent the driver from misunderstanding the actual driving mode as much as possible.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a part-time four-wheel drive vehicle according to an embodiment of the present invention, where 1 is the vehicle body, 2 is an engine mounted in a so-called vertical position at the front end of the vehicle body 1, and 3 is the engine 2.
This is a manual transmission that changes the output rotation of the transmission 3, and a transfer device 6 is disposed at the rear of the transmission 3. It is connected to wheels 5.5 via front and rear differential mechanisms 35, 36, respectively.

As shown in enlarged detail in FIG. 4, the transfer device 6 has a transfer case 7 connected to a case 3a of the transmission 3, and an output shaft 3b of the transmission 3 is disposed in the transfer case 7. Input shaft 8 arranged on the same axis
, a front wheel side output shaft 9 arranged parallel to the input shaft 8 on the side of the input shaft 8, and a model arranged on the same axis as the input shaft 8 behind the input shaft 8 (to the right in the figure). The wheel side output shafts 10 are each rotatably supported. 1yi of the input shaft 8 above
At the end, that is, at the end of the transmission 3, there is a connection from the engine 2 to the wheels 4.
．． An H-1 switching mechanism 11 is provided for switching the transmission ratio of power transmitted to the engine 5 from high speed mode to low speed mode. This H-1 switching mechanism 11 includes a sun gear 13 that is rotatably supported on an input shaft 8, and a plurality of pinions that are spline-coupled to the input shaft 8 at the rear of the sun gear 13 to rotate integrally, and mesh with the ring gear 13. 14.14.・・・
· A pinion carrier 15 carrying the pinion 1 and the pinion 1
The ring gear 16 has teeth 1'6a formed on its outer peripheral surface that mesh with teeth 7a formed on the inner surface of the transfer case 7. and is fixed to the transfer case 7 in a non-rotatable manner. on the other hand,
Sun gear spline teeth 13a are formed on the outer periphery of the front end of the sun gear 13, and spline teeth 15a for pinion carrier are formed on the inner periphery of the front end of the pinion carrier 15, respectively. Further, a cylindrical member 17 whose front end is spline-coupled to the output shaft 3b of the transmission 3 to rotate integrally is disposed around the front end of the input shaft 8, and the outer circumferential surface of the rear end of the cylindrical member 17 is for use with the sun gear. A spline tooth portion 17a having the same diameter as the spline tooth portion 13a is formed, and the spline tooth portion 17a has a sun gear spline tooth portion 13a at its rear end.
A sleeve 18 having an inner peripheral spline tooth portion 18a that can be engaged with the spline tooth portion 18a is slidably and integrally spline connected to the rear end of the sleeve 18. A spline tooth portion 18b is formed. Then, this sleeve 18 is slid on the cylindrical member 17, and the outer peripheral spline tooth portion 18b is connected to the spline tooth portion 15a for the binion carrier.
Alternatively, by selectively meshing the inner spline teeth 18a with the sun gear spline teeth 13a, the power transmission ratio is switched to low speed mode or high speed mode, and the sleeve 18 is moved to the front high speed mode as shown by the solid line in the figure. When positioned at position PH and the outer peripheral spline tooth portion 18b is engaged with the pinion carrier tooth portion 5a,
The output shaft 3b of the transmission 3 is directly and rotationally connected to the transfer human power shaft 8 via the pinion carrier 15, and the rotation of the output shaft 3b is directly transmitted to the input shaft 8 without deceleration, thereby improving the power transmission ratio. is the high-speed mode. On the other hand, when the sleeve 18 is positioned at the rear low speed position flPL as shown by the imaginary line and the inner peripheral spline tooth portion 18a is engaged with the sun gear tooth portion 13a, the transmission output shaft 3
b is transmitted to the transfer human power shaft 8 via the sun gear 13, each pinion 14 and the pinion carrier 15,
By decelerating the rotation, the power transmission ratio is set to a low speed mode.

On the other hand, a planetary gear type center differential 19 is disposed at the rear end of the transfer input shaft 8. A sun gear 20 of the center differential 19 is rotatably supported on the input shaft 8, and a pinion carrier 22 supports each pinion 21.
is rotatably spline-coupled to the input shaft 8 on the rear side of the sun gear 2o, and the ring gear 23 is rotatably coupled to the rear-wheel-side output shaft 11.

Further, a drive sprocket 24 is rotatably supported on the input shaft 8 on the front side of the center differential 19, and between the sprocket 24 and a driven sprocket 25 rotatably coupled to the front wheel side output shaft 9. A chain 26 is wound around the wheel, and the chain 26 transmits the rotation of the input shaft 8 to the output shaft 9 of the front wheel.

Further, the sun gear 20 and ring gear 23 of the center differential 19 are each extended forward, and a clutch hub 27 having spline teeth 29a on the outer peripheral surface is connected to the rotating body at the front end of the extended portion of the sun gear 20. on the other hand,
The extension part of the ring gear 23 is supported on the outer periphery of the extension part of the sun gear 20 so as to be relatively rotatable, and a spline tooth part 23a having the same diameter as the spline tooth part 27a on the outer periphery of the clutch hub 27 is formed on the outer periphery of the extension part. ing. moreover,
The driving sprocket 24 is extended rearward, and a spline tooth portion 24a having the same diameter as a spline tooth portion 27a on the outer periphery of the clutch hub 27 is formed on the outer periphery of the extended portion. Furthermore, each spline tooth portion 17a, 23a, 24a of the clutch hub 27, the ring gear 23 of the center differential 19, and the drive sprocket 24 is provided with a sleeve 2.
8 is slidably spline-coupled at its inner circumferential spline tooth portion 28a, and the shift rod 2 is connected to this sleeve 28.
A shift fork 30 fixed to 9 is movably locked, and the shift rod 29 is movably connected to a control rod 31 that is moved by an electric motor 32. The rotation of the motor 32 in one direction (CCW direction) moves the sleeve 28 forward (to the left in the figure) and in the other direction (CCW direction).
The sleeve 28 is moved backward (to the right in the figure) by rotation in the W force direction.
By operating the sleeve 28, the center differential 19 is switched to a free state, a locked state, a two-wheel drive state, or a four-wheel drive state, and the sleeve 28 is moved to the four wheels at the front end as shown by imaginary lines in the figure. When the drive/center differential is positioned at the free position r11p4F, the clutch hub 27 and the drive sprocket 24 are rotationally connected to
In addition to setting the wheel drive mode, the ring gear 23 of the center differential 19 and the sun gear 20 are disconnected, so that the center differential 19 is set in a free state. Also, yJ114)li5
When the four-wheel drive/center differential lock position P4L is positioned, the clutch hub 27 and the drive sprocket 24 are rotationally connected to each other in the same way as described above to set the four-wheel drive mode, and the ring gear 23 and sun gear of the center differential 19 are 20 to lock the center differential 19. Further, when the sleeve 28 is positioned at the rear end two-wheel drive position P2 as shown by the solid line in the figure, the ring gear 23 of the center differential 19 and the sun gear 20 are connected to lock the center differential 19, and the clutch hub A drive mode switching mechanism 33 is configured to disconnect the drive sprocket 27 from the drive sprocket 24 and switch to a two-wheel drive mode.

In FIG. 4, reference numeral 34 denotes a center differential switching detection switch that detects the switching position of the drive mode switching mechanism 33 based on the movement position of the shift rod 29.

The front and rear output shafts 9.10 of the transfer device 6 are connected to the front and rear differential mechanisms 35.3 via propeller shafts (not shown), respectively.
6. The front differential mechanism 35 includes a housing 37 as shown in enlarged detail in FIG.
A differential gear mechanism 38 is rotatably supported within the housing 37. This gear mechanism 38 is spline-coupled to a differential case 39 that is rotatably supported by a housing 37, and to each inner end of left and right axle shafts 46 and 46 that extend in the left-right direction (vertical direction in the figure) inside the differential case 39. A pair of opposing side gears 4
0.40, a binion shaft 41 rotatably supported by the differential case 39, and a pair of opposing binions 42, 42 that are rotatably fixed to the binion shaft 41 and mesh with each of the side gears 40. A ring gear 43 made of a bevel gear is rotatably fixed to the outer periphery of the differential case 39, and a drive pinion 44 is attached to the ring gear 34.
The pinion 44 is integrally formed with an input shaft 45 connected to the front wheel side output shaft 9 of the transfer device 6.

Further, in the front differential mechanism 35, a joint shaft 47 connecting the axle shaft 46 and the right front wheel 4 is concentrically arranged on the outer extension line of the axle shaft 46 on the right side (upper side in the figure), which is the output part of the front differential mechanism 35. It is located. A small diameter portion 47a smaller in diameter than other portions is formed at the portion of the joint shaft 47 facing the axle shaft 46, while a smaller diameter portion 47a is formed at the outer end (right end portion) of the axle shaft 46 than the other portion. A large-diameter portion 46a is formed, and a fitting recess 46b is provided on the end face of the large-diameter portion 46a, into which the tip of the small-diameter portion 47a of the joint shaft 47 is fitted relatively rotatably. Further, the large diameter portion 46a of the axle shaft 46
While a spline tooth portion 46C is formed on the outer periphery,
A spline member 48 having a spline tooth portion 48a corresponding to the spline portion 46c of the axle shaft 46 on the outer periphery is rotatably fixed to the outer periphery of the small diameter portion 47a of the joint shaft 47. Further, a sleeve 49 is attached to the outer peripheral spline tooth portion 48a of the spline member 48 and the spline tooth portion 46c of the axle shaft 46.
8a and 46C are slidably spline-coupled, and the sliding of this sleeve 49 causes the spline member 48
and spline tooth portions 48a, 46C of the axle shaft 46
By switching between the meshing state and the non-meshing state,
A clutch mechanism 50 is configured to connect the differential seven-wheel barrel mechanism 35 and the front wheels 4, 4 so as to enable power transmission or to interrupt the power transmission.

A fork 51 is movably locked to the sleeve 49, and the fork 51 is attached to a shift rod 52 which can be moved in the same direction (left and right direction) as the sleeve 49.
-@ (left end) of the shift rod 52, and the thin end (right end) of the shift rod 52 is fixed to the diaphragm device 5 as an actuator.
It is connected to 3. This diaphragm device 53 includes a diaphragm 54 connected to the shift rod 52, and two negative pressure chambers 55 and 56, a first and a second negative pressure chamber, defined by the diaphragm 54, as shown in FIG. As shown in FIG.
The intake negative pressure is introduced into the intake air. In addition, normally closed first and second solenoid valves 59 and 60 are respectively disposed in each of the negative pressure passages 57 and 58, and the clutch mechanism 50 is actuated by VRM control of these solenoid valves 59 and 60. When the control is performed to open the first solenoid valve 59, the clutch mechanism 50 is disengaged and the right axle shaft 46 connected to the front differential mechanism 35 and the joint connected to the right front wheel 4 are connected. When the connection with the shaft 47 is cut off and the front wheels 4.4 (idling wheels) rotate, each side gear 4 of the differential mechanism 35
By rotating only the zero and binion 42,
While preventing the rotation of the front wheel 4.4 from being transmitted to the transfer device 6, on the other hand, when the second solenoid valve 60 is opened, the clutch mechanism 50 is connected and the axle shaft 46 and the joint are connected. A freewheel device 61 that is rotatably connected to the shaft 47.
is configured.

In FIG. 3, 62 is a clutch connection detection switch that detects whether the clutch mechanism 50 of the freewheel device 61 is in a connected state based on the movement position of the shift rod 52, and 63 is a clutch connection detection switch of the same clutch mechanism. 50 is a letter of withdrawal
This is a clutch l!I disengagement detection switch that detects when the clutch l!I is disconnected.

an electric motor 32 for controlling the drive mode switching mechanism 33;
The operation of the first and second solenoid valves 59 and 60 is controlled by a controller 64 as shown in FIG. The controller 64 receives output signals from the three detection switches 34, 62, and 63, and a transfer switching operation device (operation means) 65, which is operated to switch the drive mode by the driver. As shown in FIG. 5, the transfer switching operation device 65 includes a 2/4 changeover switch 66 and a center differential lock changeover switch 67, and the 2/4 changeover switch 66 is connected to a steering shaft (see FIG. (not shown) is attached to a column change lever 69 for switching and controlling the HL switching mechanism 11 of the transfer device 6, which is rotatably provided around the transfer device 6. As shown in enlarged detail in FIG. 6, the 2/4 changeover switch 66 is a momentary type slide switch that is always biased and held in the right-hand steady position, and is moved from the normal position to the left-hand switching position. The first slide operation outputs a command signal to switch from 2-wheel drive state to 4-wheel drive state, and the second slide operation thereafter outputs a command signal to cancel the switching (from 4-wheel drive state to 2-wheel drive state). It is configured to output a return signal).

On the other hand, the center differential lock changeover switch 67 is attached to the instrument panel 70. This center differential lock changeover switch 67 consists of a push button switch, and when pressed for the first time, it is held in the pressed position and outputs a command signal to switch and maintain the center differential 19 in the locked state, and then when pressed again. Then, it jumps back to its original state and outputs a command signal to switch and maintain the center differential 19 in the free state.

Then, the HL switching mechanism 11 of the transfer device 6
is positioned at the high speed position P■ and in the high speed mode, by switching the 2/4 changeover switch 66 and the center differential lock changeover switch 67, the two-wheel drive/B speed mode 2H is set.

Switch between 3 modes: 4-wheel drive/high-speed/center differential free mode 4HF and 4-wheel drive/high-speed/center differential lock mode 4HL, and as shown in Figure 7, 2-wheel drive/high-speed mode 2H and 4-wheel drive/high-speed/ When switching between center differential free mode 48F and 2-wheel drive/A speed mode 2nd and 4-wheel drive/high speed/center differential lock mode 4HL by sliding the 2/4 changeover switch 66.
When switching between the four-wheel drive/high speed/center differential lock mode 48F and the center differential lock mode 4HL, the center differential lock changeover switch 67 is operated.

Further, connected to the controller 64 are a buzzer device 71 that notifies the driver of the switching of the drive mode by sounding, and a lighting display device 72 that indicates the switching of the drive mode by lighting a lamp. As shown in FIG. 5, the lighting display device 72 includes a four-wheel drive indicator lamp 73 (4WD lamp) and a center differential indicator lamp 74 (C/D lamp) arranged on the instrument panel 70. The four-wheel drive indicator lamp 73 lights up in four-wheel drive mode, and the two
The center differential display lamp 74 is set to be turned off in the wheel drive mode, turned on in the center differential lock mode, and turned off in the free mode.

The controller 64 constitutes the electrical control means in the present invention, and the operation control procedure for the motor 32, solenoid valve 59, 60, buzzer device 71, and lighting display device 72 in the high-speed mode will be explained in the eighth section below. This will be explained with reference to FIGS.

Figure 8 shows 2-wheel drive mode from 2nd to 4th with center differential free.
The flow of a subroutine when switching to wheel drive mode 4HF is shown. In this flow, by receiving a command signal accompanying the switching operation of the 2/4 changeover switch 66, first,
In the first step S1, the buzzer device @71 is sounded for, for example, 150 m seconds to generate an operation acceptance sound, and in the next step S2, the four-wheel drive display lamp 73 in the lighting display device 72 is blinked. This blinking is performed, for example, in a blinking form in which the ratio of the lighting time is greater than the turning-off time, and this blinking form indicates to the driver that the switching from the two-wheel drive mode to the four-wheel drive mode is in progress.

After that, the process proceeds to step S3, where the motor 32 is connected to the CC
Electrification is applied so that the sleeve 28 of the drive mode switching mechanism 33 rotates in the W direction (the direction in which the sleeve 28 of the drive mode switching mechanism 33 moves forward), and the drive mode switching mechanism 33 is moved from the rear two-wheel drive position P2 to the front middle four-width side vJ. /Switch to center differential lock position P4L to lock center differential 19. After that, in step S4, the drive mode switching mechanism 33 is actually switched to the four-wheel drive center differential lock position P4L based on the output signal of the center differential change detection switch 34, and the drive mode is changed to four-wheel drive/high speed/center. Differential lock mode 4H
It is determined whether it has become L, and steps 83 and 84 are repeated until this determination becomes YES. If the determination is YES, in step S5, an ON signal is output to the second solenoid valve 60 to connect the clutch mechanism 50 of the freewheel device 61, and the freewheel device 6
1 to lock state. After that, in step S6, based on the output signal of the clutch connection detection switch 62, it is determined whether the clutch mechanism 50 has actually been switched to the connected state and the freewheel device 61 has entered the locked state. Step 85 until the determination is YES.
Repeat 86. If the determination is YES, in step S1, the motor 32 is energized again to rotate in the CCW direction, and the drive mode switching mechanism 33 is set to the four-wheel drive/center differential lock position rI! Switch from IP4L to the front four-wheel drive position/center differential free position fltP4F to put the center differential 19 in the free state. After this, in step S8, the center differential changeover detection switch 3
Based on the output signal of No. 4, the drive mode switching mechanism 33 determines whether the four-wheel drive center differential free position P4F has actually been switched and the drive mode has become four-wheel drive/high speed/center differential free mode 48F. , this semi-definite is YE
Repeat steps 87 and 88 until S is reached, and the determination is Y.
It ends when it reaches ES.

Figure 9 shows 4 from 2-wheel drive mode 2H to center differential lock.
The flow of a subroutine when switching to wheel drive mode 48L is shown. In this flow, by receiving each command signal accompanying the switching operations of the 2/4 changeover switch 66 and the center differential lock changeover switch 67, first, in the first step S11, the buzzer device 71 is
The sound is blown for 0 m seconds to generate an operation acceptance sound in the same manner as above, and in the next step 812, the four-wheel drive indicator lamp 73 and center differential indicator lamp 74 in the lighting display device 72 are blinked in the same manner as above, and after that, Step 81 similar to steps 83 to S6 in the above subroutine
Execute steps 3 to 316. That is, the process proceeds to step S13, where the motor 32 is energized to rotate in the CCW direction to lock the center differential 19, and then, at step 814, the drive mode is set based on the output signal of the center differential changeover detection switch 34. It is determined whether or not the vehicle is in the four-wheel drive/high speed/center differential lock mode 4HL, and steps 813 and 814 are repeated until this determination becomes YES. If the determination is YES, in step 816, an ON signal is output to the second solenoid valve 60,
In step 816, it is determined based on the output signal of the clutch connection detection switch 62 whether or not the freewheel device 61 is actually in the locked state, and if this determination is Y.
Steps 815 and 816 are repeated until the determination is YES, and the process ends when the determination is YES.

Also, Figure 10 shows four-wheel drive mode 4 with center differential lock.
The flow of the subroutine when switching from 8L to center differential free four-wheel drive mode 48F is shown. This 70
- In response to the reception of a command signal accompanying the switching operation of the center differential lock changeover switch 67, first, in the first step 821, the buzzer device 171 is activated,
A sound is blown for 07 FL seconds to generate an operation acceptance sound in the same manner as above, and in the next step 822, the center differential display lamp 74 is blinked.After this, the process proceeds to step 823, and the motor 32 is caused to rotate in the CCW direction. The drive mode switching mechanism 33 is switched from the 4-wheel drive/center differential lock position fip4L to the 4-width side e/center differential free position p4F on the front side, and the center differential 19 is set in a free state. Then, in step 824, it is determined whether or not the drive mode has become 4-wheel section fJ]/high speed/center differential free mode 4) (F), and this determination is YES.
Steps 823 and 824 are repeated until S is reached, and when the determination becomes YES, the process ends.

Further, FIG. 11 shows the flow of a subroutine when switching from the center differential free four-wheel drive mode 48F to the center differential lock four-wheel drive mode 48L, contrary to the above. In this flow, upon reception of a command signal accompanying the switching operation of the center differential lock changeover switch 67, in the first step 831, the buzzer device d71 is made to sound for, for example, 150 TrL seconds to generate an operation acceptance sound in the same manner as above; In the next step 832, the center differential display lamp 74 is made to blink, and in the next step 833, the CW force direction drive mode switching mechanism 33 is switched to the motor 32.
The sleeve 28 is energized to rotate in the direction in which the sleeve 28 moves rearward), and the drive mode switching mechanism 33 is switched from the 4-wheel drive/center differential free position 1tP4F to the rear 4-width side a/center differential lock position P4L, Center differential 19
to the locked state.

Then, in step 834, it is determined whether the drive mode is 4-wheel drive/high speed/center differential lock mode 4HL, and step 834 is continued until this determination becomes YES.
3. Repeat 834 and end when the determination becomes YES.

FIG. 12 shows the flow of a subroutine when switching from the center differential free four-wheel drive mode 4HF to the two-wheel drive mode 2H. In this flow, the buzzer device! 71 for, for example, 150 m seconds, the next step 84
2, the four-wheel drive indicator lamp 73 in the lighting display device 72 is blinked. This flashing is performed in the opposite manner from the above-mentioned transition from 2-wheel drive mode to 4-wheel drive mode, for example, in a flashing format in which the ratio of off time is greater than on time, and this flashing format allows switching from 4-wheel drive mode to 2-wheel drive mode. Display to the driver that switching is in progress.

At step 843, the motor 32 is energized to rotate in the CW force direction, and the drive mode switching mechanism 33 is set to the front end four-wheel drive/center differential free position! ! ! Switch from P4F to the intermediate 4-wheel drive/center differential lock position fiP to the rear end 2-wheel drive position IP2, and set the center differential 19 to 2.
Set to wheel drive. Then, in step 844, the drive mode switching mechanism 33 is actually switched to the two-wheel drive position P2 based on the output signal of the center differential changeover detection switch 34, and the drive mode is changed to the two-wheel drive position P2.
The above steps 843 and 844 are repeated until the determination becomes YES. Then, if the determination becomes YES, the process moves to step S45, and the first
The process ends after outputting an ON signal to the solenoid valve 59 to disengage the clutch mechanism 50 of the freewheel device 61 and bringing the freewheel device 161 into an unlocked state.

By the way, each of the subroutines shown in FIGS. 8 to 12 above shows all the cases where the change destination drive mode is allowed to be changed. Therefore, if the drive mode to be changed newly selected by the transfer switching operation device 65 does not correspond to each of the above-mentioned subroutines, the switching operation is not accepted. In other words, in the case of this embodiment, the transfer switching operation device 65
is operated to change the drive mode from 4-wheel drive/IX speed/center differential lock mode 48L to 2-wheel drive mode 2H (i.e., center differential lock changeover switch 6
This occurs when the 2/4 changeover switch 66 is slid while the switch 7 is pressed in.

When such an operation is performed, the control means executes an erroneous operation subroutine shown in FIG. 13. That is, in the first step 851 of this erroneous operation subroutine, the buzzer device 7 is activated.
1 is blown three times at intervals of 150 msec, for example, to generate an erroneous operation sound, and the control is terminated without performing any switching operation control.

In the case of this embodiment, the 2/4 changeover switch 66 is a momentary type, so when the switching operation is performed from the 4-wheel drive/high speed/center differential lock mode 4HL to the 2-wheel drive mode 2nd, the switch 66 is of a momentary type. Even if no switching command is received, there will be no unmatching between the drive mode selection position of the transfer switching operation device 65 and the actual drive mode, and therefore it is possible to prevent the drive mode from being changed by generating an erroneous operation sound. All you need to do is warn the driver. However, if the 2/4 changeover switch 66 is a state holding type, or each of the three drive modes 2H
, 4HL, and 4HF are directly selected using three selection switches, etc., when the selection position of the transfer switching operation device 65 (two-wheel drive mode position fi2) is selected.
This means that it is positioned at H. ) and actual drive mode (4-wheel drive/high speed/center differential lock mode 4HL)
It remains as it is. ), if unmatching occurs between
It is better to make the buzzer device 71 sound and continue to generate the warning sound until the state is returned to 4HL.

Therefore, as is clear from the above explanation, in this example,
The drive mode selection position of the transfer switching operation device 65 is 4-wheel drive/high speed/center differential lock mode 4H.
If the driver accidentally operates the transfer switching operation device 65 and switches to 2-wheel drive mode 2H while the vehicle is running in 4-wheel drive/high speed/center differential lock state in L mode, the Generates a warning sound for erroneous operation without switching. When the transfer switching operation device 65 is operated to switch to a drive mode that is permitted to switch to another drive mode, an operation acceptance sound is generated to accept the switch, and the actuator is actuated to switch to the drive mode to which the switch is to be made. do. Therefore, when the driver makes an incorrect operation, it is possible to reliably warn the driver, and it is possible to prevent the driver from misrecognizing the drive mode while driving as much as possible. It becomes like this.

(Effects) In summary, according to the present invention, when the operating means is erroneously operated and a command to change to a drive mode for which switching is prohibited is issued, the command for the switching operation is not accepted and an erroneous operation sound is generated. On the other hand, when a command to change to a drive mode that is allowed is issued, an operation acceptance sound for the switching operation is generated and the drive mode switching mechanism is switched to the drive mode to which it is to be changed. This makes it possible to reliably warn the driver of erroneous operation of the operating means, and to prevent the driver from misrecognizing the drive mode while driving as much as possible. Become.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the present invention, in which Fig. 1 is a schematic side view of a four-wheel drive vehicle, Fig. 2 is an overall configuration diagram of the operating means, and Fig. 3 is a front differential mechanism and freewheel device. 4 is a sectional view of the transfer device, FIG. 5 is a front view showing the arrangement of the transfer switching operation system, FIG. 6 is an enlarged view of the 2/4 changeover switch mounting part, and FIG. 7 is a sectional view of the transfer device. An explanatory diagram showing the drive mode switching path. Fig. 8 is a flowchart showing a subroutine for switching from 2-wheel drive mode to center differential-free 4-wheel drive mode. Fig. 9 is a flowchart showing a subroutine for switching from 2-wheel drive mode to center differential-free 4-wheel drive mode.
A flowchart diagram showing a subroutine for switching to wheel drive mode, Figure 10 is a flowchart diagram showing a subroutine for switching from a four-wheel drive mode with a center differential lock to a center differential free mode, and Figure 11 is a four-wheel drive mode with a center differential free. Fig. 12 is a flowchart showing the subroutine for switching from center differential free 4-wheel drive mode to 2-wheel drive mode, and Fig. 13 is a flowchart showing the subroutine for erroneous operation. It is. 6... Transfer device 19... Center differential 32... Actuator motor 33...
... Drive mode switching mechanism 64 ... Controller 65 as control means...
... Patent applicant for the transfer switching operation device which is the operation means Agent of Mazda Co., Ltd.
Patent Attorney - Ken Iro Patent Attorney Masatoshi Matsumoto (Figure 8, Figure 9, Figure 10, procedural amendment oral format) February 24, 1988 Commissioner of the Patent Office Kunio Ogawa, 1, Indication of Cases 1988 Patent Application No. 271700 2, Name of the invention: Drive mode switching control device for four-wheel drive vehicles 3, Relationship with the person making the amendment Case Patent applicant address: Rokin Shinbashi Building, 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture 7th Floor Name (8768) Patent Attorney Matsumoto
Masari 5. Date of amendment order: January 26, 1986 (dispatch) 6. Subject of amendment (1) Drawing 7. Contents of amendment (1) Drawings 3 and 4 originally attached to the application. Engraving of the figure, as shown in the attached sheet (no changes to the content)

Claims (1)

[Claims] The driving state of a transfer device having a center differential is two.
A drive mode switching mechanism for switching between a wheel drive state, a four-wheel drive/seta differential lock state, and a four-wheel drive/center differential free state; an actuator for switching the drive mode switching mechanism; and an operating means for selecting each of the drive modes. , the operation of the actuator is controlled based on an output signal from the operating means, and the drive mode to be changed newly selected by the operating means is a drive mode that is permitted to be changed from the current drive mode. If so, generate the operation acceptance sound and control the operation of the actuator based on the output signal, and if the newly selected change destination drive mode is the one for which switching is prohibited, the change is accepted. 1. A drive mode switching control device for a four-wheel drive vehicle, comprising: a control means for generating a warning by generating an erroneous operation sound.