JPS62237152A - Control device for four wheel drive transmission provided with auxiliary transmission - Google Patents

Abstract

PURPOSE:To make it possible eliminate a shift lever from an auxiliary transmission, by controlling the change-over operation of a high/low speed stage change- over valve and a two/four wheel drive change-over valve with the use of solenoid valves, respectively. CONSTITUTION:A microcomputer 50 controls the change-over operation of a change-over valve 20 for changing over between higher and lower speed stages and a drive force distributing valve 70 for changing over between two and four wheel drive modes in accordance with a signal from a selection switch 90, withe the use of solenoid valves 60, 80 which are provided for both valves, respectively. Accordingly, it is possible to eliminate a shift lever from an auxiliary transmission and a link mechanism accompanied with the lever, which have been conventionally required, so that the restriction to the space occupied by the automatic transmission may be alleviated, and further, it is possible to facilitate the assembly of the vehicle. Further, if there is provided such an arrangement that the two wheel device mode may have a high rotational speed when the associated solenoid valve is turned off, a fail safe measure may be taken upon abnormality such as failure of an electrical system for the like.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a control device for a four-wheel drive transmission, and particularly to a control device for a four-wheel drive transmission, and in particular a control system for controlling front and rear wheels, including high-speed drive and deceleration drive by an auxiliary transmission, and two-wheel drive by a drive force distribution mechanism. This relates to a device that controls the distribution rate of force.

Conventional technology Automatic transmission for four-wheel drive is disclosed in Japanese Patent Application No. 59-2754, for example.
It is proposed by No. 83. This system automatically switches the main transmission, which is connected to the engine via a torque converter, depending on the range selected by the shift lever, throttle opening, or vehicle speed, and also transfers the output of the main transmission to the auxiliary transmission. High speed (reduction ratio = 1) and deceleration (
This is a configuration in which the output of the auxiliary transmission is roughly transmitted to either or both of the front export power shaft and the rear export power shaft. Conventionally, the shift lever for the main transmission and the high speed two-wheel drive (H2) transmission,
Two shift levers are provided, one for switching to high-speed four-wheel drive (H4) and one for switching to deceleration four-wheel drive (L4), and the drive state that matches the driving conditions is selected using these two shift levers. The manual valve connected to the valve is configured to be operated by switching the manual valve.

Problems to be Solved by the Invention In the above-mentioned conventional automatic transmissions, the shift lever is provided in the driver's seat and connected to the manual valve by a wire or link, or two shift levers are installed in the driver's seat in an extremely limited space. It is difficult to arrange a book shift lever without impairing its operability, and there is a risk that the shift lever may not be placed in the correct position due to interference with other operating devices. Additionally, the wire link device that transmits the movement of the shift lever to the manual valve also has problems in its handling and placement.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a control device capable of setting a driving state by operating a switch in a four-wheel drive sub-transmission gearbox.

Means for Solving the Problems In order to achieve the above object, the present invention provides an L-transmission system that performs a switching operation of an auxiliary transmission capable of changing a plurality of gear stages.
An H switching valve, a first electromagnetic valve that operates this L-H switching valve, a driving force distribution switching valve that operates a driving force distribution mechanism that changes the distribution ratio of driving force to front and rear wheels, and this driving force distribution switching valve. A second solenoid valve is provided, and by controlling each solenoid valve on and off, it is possible to change gears in the sub-transmission and change the distribution ratio of driving force to the front and rear wheels, including two-wheel drive. It is designed to do so.

In addition, when each solenoid valve is turned off, the L-H switching valve is operated so that the auxiliary transmission is in a higher gear, and the driving force distribution groove is in a state where power is transmitted only to either the front or rear wheels. The driving force distribution switching valve is configured to perform a switching operation so as to achieve the following.

Function: In the control ffI device of the present invention, when the first solenoid valve is turned on or off by switch operation, L
The -H switching valve operates in a state corresponding to the first electromagnetic valve, and accordingly, the 01 transmission is set to one of the gears depending on the state of oil pressure supplied from the L-H switching valve. Also, if the second solenoid valve is turned on or off by switch operation, it will operate in a state corresponding to the state of the driving force distribution switching valve or the second N solenoid valve, and accordingly, the driving force distribution mechanism will drive the front and rear wheels. The power distribution ratio changes and is set from a four-wheel drive ratio of 1:1 to a two-wheel drive ratio of 1:0. Therefore, each drive state, such as high-speed two-wheel drive or deceleration four-wheel drive, can be set by operating a switch.

For example, if each solenoid valve is turned off due to an abnormality in the electrical system,
The sub-transmission shifts to a higher gear, and the drive force distribution mechanism switches to transmit power to only one of the front and rear wheels, resulting in a two-wheel drive with a high rotational speed.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram showing one embodiment of the present invention.
The figure is a schematic diagram showing an example of a transmission targeted by the control device. First, to explain the structure of the transmission, the structure shown in FIG.
This is a simplified version of the configuration shown in the drawing of No. 1, in which a main transmission 1 that performs multiple forward gears and one reverse gear shift is connected to an engine 3 via a torque converter 2. The output shaft of the machine 1 serves as the input shaft of the sub-transmission 4. This input shaft 5 is directly connected to a sun gear 6 of a planetary gear mechanism, and is also connected to a planetary carrier 7 via a hydraulic clutch C3. Also, a ring gear 9 that engages with the pinion 8 and a fixed part 10 such as a casing
A hydraulic brake B4 for stopping the rotation of the ring gear 9 is provided between the ring gear 9 and the ring gear 9. The rear export power shaft 11 is directly connected to the carrier 7, and the power transmission groove 12 is further connected to the carrier 7 via a hydraulic clutch C4 for switching between two-wheel drive and four-wheel drive. The power transmission groove 12 is for transmitting power to the front export force shaft 13, and each row is composed of a pair of sprockets and a chain wound around the sprockets. That is, the configuration is such that each drive state of high-speed two-wheel drive (H2>), high-speed four-wheel drive (g14), and deceleration four-wheel drive (L4) is achieved by engaging and releasing the clutches C3, C4 and brake B4. Therefore, the clutch C4 and the power transmission mechanism 12 function as a driving force distribution mechanism.

The configuration of the control device for controlling the sub-transmission 4 of the above-mentioned transmission is as shown in FIG. That is, L-H switching valve 2
0 is for controlling engagement and release of the clutch C3 and brake B4 in the sub-transmission 4 described above to switch the sub-transmission 4 to a high-speed drive state and a deceleration drive state, and a line oil pressure supply port 21; 22 to the C3 boat 1 communicated with the clutch C3, the B4 boat 23 communicated with the brake B4, the first drain boats 1 to 24 that communicate the C3 boat 22, the second drain boat 25 that communicates the B4 boat 23, and the line hydraulic pressure. It is a one-channel configuration having each control port 26 for supplying and moving the valve body.

A line hydraulic oil line 40 is connected to the line hydraulic pressure supply boat 21, which supplies line hydraulic pressure regulated by a primary regulator valve (not shown) in the main transmission hydraulic control device 30. The control port 26 communicates with a line hydraulic oil passage 40 via an orifice 41. This L-H switching valve 20 is shown in more detail in FIG. 3. That is, the example shown here is configured as a spool valve, and the spool 27 having three lands is movably accommodated in the valve body 28, and the face areas of the lands at both ends are set equal. Furthermore, a spring 29 is arranged on the opposite side of the control boat 26 to press the spool 27 in the axial direction. Therefore, when line hydraulic pressure is supplied to the control boat 26, the spool 27 moves in the direction of compressing the spring 29,
The C3 boat 22 communicates with the line hydraulic supply boat 21 and the 84 boat 23 communicates with the second drain boat 25. Conversely, when the control boat 26 is depressurized, the spool 27 is pushed by the spring 29. Move, C3
The boat 22 is configured to communicate with the first drain boat 24, and the B4 port 23 communicates with the line oil pressure supply ports i-21.

The main transmission hydraulic bullet suppressor @ 30 is controlled by an output signal from the microcomputer 50 based on a transmission diagram preset in relation to the throttle opening and the output shaft rotation speed, and controls the hydraulic pressure supply path. The gear position of the main transmission 1 is changed by switching. In the main transmission hydraulic control device 30, the oil pressure pumped up from an oil reservoir 32 by an oil pump 31 and generated is regulated to predetermined line oil pressure and throttle oil pressure.

An S4 solenoid valve 60 that is controlled on and off by an output signal from the microcomputer 50 is interposed in the oil path between the control port 26 and the orifice 41 for the L-H switching valve 20. ing. This S4
The electromagnetic valve 60 includes a plunger-type valve body 62 that opens and closes the port 61, a spring 63 that presses the valve body 62 in the direction of closing the port 61, and a spring 63 that presses the valve body 62 against the spring 63 when turned on, that is, when it is energized. In the OFF state, the valve body 62 closes the port 61 to apply line hydraulic pressure to the control port 26, and on the other hand, in the ON state, the valve body 62 closes the port 61. is configured to drain the line hydraulic pressure acting on the control port 26 by opening the port 61.

On the other hand, the engagement of the clutch C4 forming the driving force distribution mechanism
The driving force distribution switching valve 70, which performs release control and switches between a two-wheel drive state and a four-wheel drive state, has a line oil pressure supply port 71 that supplies line oil pressure, and the clutch C4.
The valve body is configured to have a C4 port 72 connected to the valve body, a drain port 73, a first control boat 74 for moving the valve body, and a second control boat 75 provided on the opposite side. To show this more specifically, as shown in Figure 3, the example shown here is necessarily constructed as a spool valve, and the spools 77 housed in the valve body 76 are composed of three spools, all of which have the same face area. A spring 78 that presses the spool 77 is disposed on the end face side of the land on the one end side where the second control boat 75 is open, and a spring 78 that presses the spool 77 is arranged roughly on the other end side. 1ilI gobo 1
~74 are open. and line hydraulic supply port 7
1 is connected to the line hydraulic oil passage 40, and
The first control boat 74 is connected to the line hydraulic oil passage 40 via the orifice 42, and the second control boat 75 is connected to the oil passage 79, which is opened in the L-H switching valve 20 and communicates with the B4 boat 23. It is connected. Therefore, when line hydraulic pressure is supplied to the first control boat 74, the spool 77 moves against the spring 78 to communicate with the C4 port 72 or the drain port 73, and the first control boat 74 is depressurized. In this case, the C4 boat 72 is configured to communicate with the line oil pressure supply port 71 by moving the spool 77 while being pushed by the spring 78. Note that the oil passage 79 is for prohibiting the deceleration two-wheel drive state, and when the L-H switching valve 20 is switched to set the deceleration drive state, the B4
The line hydraulic pressure is applied to the second control boat 75 from the port 23, and even if the line hydraulic pressure is not supplied to the first control boat 74, the spool 77 is pressed and moved toward the first control port 74, and the C4 port 72 is controlled to the line hydraulic pressure. It is configured to communicate with the supply port 71.

The first of the oil passages for this driving force distribution switching valve 70
An 85 solenoid valve 80 having the same configuration as the S4 solenoid valve 60 described above is installed in the oil passage between the control boat 74 and the orifice 42 . That is, this S5 solenoid valve 80 is also controlled on and off by the microcomputer 50, and in the on state, the coil 81 is excited and pulls back the plunger type valve body 82 against the spring 83, and as a result, the port is closed. 84 is opened and the first control boat 74
The coil 81 is demagnetized in the OFF state, the valve body 82 is pushed by the spring 83 to close the port 84, and the line hydraulic pressure is supplied to the first control port 74. .

A microcomputer 50 controls each electromagnetic valve 60, 80 in conjunction with the main transmission hydraulic control device 30.
A selection switch 90 is connected to select each drive state of high-speed two-wheel drive (H2), high-speed four-wheel drive (H4), and deceleration four-wheel drive (L4). That is, the selection switch 90 has three contacts H2, H4 and L4,
If H2 is selected, each solenoid valve 60.80 is turned off, if G14 is selected, only S5 solenoid valve 80 is turned on, and if L4 is selected, each N solenoid valve 60 is turned off.
．． 80 is turned on. Next, the operation of the control device having the above configuration will be explained with reference to the flowchart shown in FIG. If the result is "yes", each solenoid valve 60° 80 is energized and turned on, and as a result, pressure is exhausted from the control port 26 in the L-H switching valve 20. The spool 27 is pushed by two springs and moves to the position shown in the right half of FIG. It is communicated with the line hydraulic pressure supply port 21, and line hydraulic pressure is supplied to the brake B4.

That is, in the sub-transmission 4, the clutch C3 is released and the brake B4 is engaged, so that the sub-transmission 4 enters a deceleration drive state in which the reduction ratio is greater than 1. On the other hand, in the driving force distribution switching valve 70, the pressure is discharged from the first control boat 74, and the line oil pressure is supplied to the second control board 5 via an oil passage 79 branched from the oil passage leading to the brake B4. acts, the spool 77 moves to the position shown in the left half of FIG. 3, and accordingly, the C4 boat 72 communicates with the line oil pressure supply boat 71, and line oil pressure is supplied to the clutch C4. Therefore, in the sub-transmission 4, the clutch C4
are engaged, and driving force is transmitted to both the rear export force shaft 11 and the front export force shaft 13. That is, the vehicle enters a deceleration four-wheel drive (L4) state.

Also, the rL4'? If the result of J's judgment process is "no", rH4? If the result is "yes", the S4 solenoid valve 60 is switched off and the 85
Only the solenoid valve 80 is turned on.

Therefore, in the L-H switching valve 20, since the line hydraulic pressure acts on the control boat 26, the spool 27 moves against the spring 29 to the position shown in the left half of FIG. The hydraulic supply port 21 communicates with the B4 port 23, and the B4 port 23 communicates with the second drain boat 25.

Therefore, in the auxiliary transmission 4, the clutch C3 is engaged and the brake B4 is released, so that the entire planetary gear gate structure is integrated, and a high-speed driving state is established in which the input from the main transmission 1 is directly output. Furthermore, since the S5 solenoid valve 80 remains the same as before, the vehicle will end up in the high-speed four-wheel drive (H4) state.

Zarani rH4? If the judgment result of J is "no", each solenoid valve 60, 80 is set to OFF, and each valve body 62, 8
2 is pushed by spring 63.83 and boat 61.84
Close. As a result, the control port 26 of the L-H switching valve 20 and the first control port 7 of the driving force distribution switching valve 70
4, and the spool 27 of the L-H switching valve 20 is in the state shown in the left half of FIG. Then, the brake B4 is discharged and released, and the entire planetary gear gate structure is brought into a high-speed driving state. In addition, in the driving force distribution switching valve 70, line hydraulic pressure is supplied to the first control boat 74 and pressure is discharged from the second control port 75, so that the spool 77
moves in the direction of compressing the spring 78 and moves to the position shown in the right half of FIG. Since it is released, it becomes two-wheel drive. As a result, the drive state becomes a high-speed two-wheel drive state in which the output of the main transmission 1 is directly transmitted only to the rear export force N11.

Incidentally, in the deceleration driving state where line oil pressure is supplied to the brake B4, the line oil pressure acts on the second control port 75 of the driving force distribution switching valve 70 via the seven oil passages, so the driving force distribution switching is performed. In the valve 70, the spool 7
Regardless of the presence or absence of line oil pressure to the first control boat 74, it is maintained at the position shown in the left half of Figure 3. Therefore, in the case of deceleration drive, it is always in four-wheel drive mode, and abnormalities such as electrical system failures are avoided. Even if there is, deceleration two-wheel drive is prohibited.

Table 1 shows the driving states set by turning on and off the electromagnetic valves 60 and 80 described above, and the engagement and release states of the clutches C3 and C4 and brake B4 that achieve the driving states. That's right.

The reason why the S5 solenoid valve 80 marked * in Table 1 is turned off and the clutch C4 is engaged is because line oil pressure is supplied to the second port 75 of the driving force distribution switching valve 70 by the seven oil passages. This is because that.

In the above-mentioned control device, if each solenoid valve 60.80 stops operating due to an electrical abnormality such as a disconnection,
Each electromagnetic valve 60.80 is turned off and the boat 61.84 is closed, resulting in a high-speed two-wheel drive state as shown in Table 1 above. In other words, in a high-speed two-wheel drive state, the driving force that moves the vehicle is weaker than in other drive states, such as a deceleration four-wheel drive state, so even if the above abnormality occurs while driving, the braking effect will not be affected. It is possible to prevent excessive reaction force acting on the transmission and the transmission, and abnormal behavior associated with these.

In the embodiments described above, the object to be controlled is a so-called part-time four-wheel drive transmission, and accordingly, the driving force distribution switching valve 70 operates only in two ways, opening and closing, with respect to the clutch C4. The control device of the present invention can be applied to various four-wheel drive transmissions, for example, to a full-time four-wheel drive transmission having a center differential mechanism that distributes driving force between front wheels and rear wheels. 1
In that case, the differential lock mechanism that limits the action of the center differential mechanism is controlled by a friction engagement device.
If configured, the driving force distribution switching valve 70 is used as a pressure regulating valve to appropriately adjust the friction force at the differential lock gate structure, and change the driving force distribution ratio between the front and rear wheels from 1:1 four-wheel drive. It can be changed in the two-wheel drive range of 1:0. Furthermore, in the above embodiment, the solenoid valves 60, 80 are directly controlled by the microcomputer 50, but if a microcomputer is used, switching to deceleration four-wheel drive during high-speed driving may be necessary. It is effective to control the regulation of switching of the drive state according to the driving state, such as by preventing this. Further, in the present invention, each solenoid valve may be directly controlled on/off by a switch.

Effects of the Invention As is clear from the above description, the control device of the present invention has a switching valve for switching between a high gear stage and a low gear stage, and a switching valve for switching between two-wheel drive and four-wheel drive. The configuration is such that the switching control is performed using a corresponding solenoid valve, so drive states such as high-speed two-wheel drive, high-speed four-wheel drive, or deceleration four-wheel drive can be controlled electrically via switches. Therefore, it is possible to omit a shift lever for an auxiliary transmission and a link mechanism associated therewith, which were conventionally required, thereby reducing space constraints and improving the ease of assembling the vehicle. Furthermore, since this invention is configured so that two-wheel drive occurs at a high rotation speed when each solenoid valve is turned off, it is possible to establish reliability, that is, fail-safe, in the event of an abnormality such as a failure of the electrical system. can.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing an embodiment of the present invention, Fig. 2 is a schematic diagram of a transmission which is an example of a controlled object, Fig. 3 is an explanatory diagram showing each switching valve in more detail, and Fig. 4 is the control flowchart 1 for each solenoid valve. 4... Sub-transmission, 11... Rear export power shaft, 12.
...power transmission mechanism, 13...front export force shaft, 20.
...L-H switching valve, 60...S4 solenoid valve, 7
0... Driving force distribution switching valve, 80... S5 solenoid valve, 90... Selection switch, C3, C4... Clutch, B4... Brake. Figure 1 Figure 2 1○ Figure 4

Claims (2)

[Claims] (1) A sub-transmission equipped with a sub-transmission that is operated by hydraulic pressure to change gears into multiple gears, and a driving force distribution mechanism that distributes and transmits the output of the sub-transmission to the front and rear wheels. The transmission for four-wheel drive with a gearbox includes an L-H switching valve that switches the auxiliary transmission to change its gear stage, and an L-H switching valve that is controlled on and off to operate the sub-transmission to change its gear stage.
A first solenoid valve that switches the H switching valve; a driving force distribution switching valve that operates the driving force distribution mechanism by hydraulic pressure to change the distribution ratio of driving force to the front and rear wheels; 1. A control device for a four-wheel drive transmission with an auxiliary transmission, comprising a second solenoid valve for switching a distribution switching valve. (2) the first electromagnetic valve is in an off state, and the L-H switching valve is operated so that the sub-transmission is in a high gear;
and the second solenoid valve is in an off state, and the driving force distribution mechanism switches the driving force distribution switching valve so as to distribute driving force only to either the front or rear wheels. A control device for a four-wheel drive transmission with an auxiliary transmission according to scope 1.