JPH059657B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a control device for a vehicle transmission equipped with an auxiliary transmission capable of switching between high speed and low speed.
In particular, the present invention relates to a control device for a vehicle transmission suitable for automatically switching a sub-transmission depending on road conditions to ensure appropriate driving force. [Prior Art] Conventionally, vehicles capable of running in four-wheel drive mode often run on rough roads such as steep slopes, uneven terrain, or steep slopes, and high traversal ability is required. In addition to the main transmission that has multiple gears, the vehicle transmission installed in such a vehicle is equipped with an auxiliary transmission that can switch between high and low gears, and the auxiliary transmission is capable of switching between high and low gears. It has been proposed that by switching to the stage side, a large driving force or a large braking force due to engine braking can be obtained. Such switching of the sub-transmission is performed by operating a shift lever etc. installed in the driver's seat, and when large driving force is required,
The driver operated the shift lever etc. to shift the auxiliary transmission to a lower gear. [Problems to be Solved by the Invention] However, when it is necessary to shift the auxiliary transmission to the lower gear side, it is necessary to move the auxiliary transmission to the low gear side when driving on rough roads such as the above-mentioned steep slopes, uneven terrain, or steep slopes. This is when driving under road conditions, and under these conditions, the driver must be skilled in operating the shift lever manually in order to obtain the appropriate driving and braking force. There was a problem with this. In order to solve this problem, it is possible to detect the slope angle of the road surface on which the vehicle is traveling and automatically switch the sub-transmission to a low gear when the slope angle is large. Forgetting to switch to drive2
If the auxiliary transmission is automatically switched to a lower gear as described above when driving in wheel drive, the increased driving force will be transmitted to the road only from the two wheels. When the vehicle is traveling on a steep slope, the tires may slip, causing a problem in which the vehicle's running ability is reduced. SUMMARY OF THE INVENTION Therefore, the present invention provides a control device for a vehicle transmission capable of switching between two-wheel drive and four-wheel drive, which secures appropriate braking force by engine braking on steeply descending slopes while preventing tire slip. The purpose is to improve the vehicle's ability to travel on steep slopes by ensuring appropriate driving force. [Means for Solving the Problems] A control device for a vehicle transmission according to the present invention includes a main transmission having a plurality of gears, and a sub-transmission having a high gear and a low gear which are switched by operating a frictional engagement element. For vehicles that are equipped with a transmission and a control device that controls the operation of the frictional engagement element for switching between a high speed gear and a low speed gear of the sub-transmission, and are capable of switching between two-wheel drive and four-wheel drive. In the transmission control device, the control device includes a drive state determining means for determining whether two-wheel drive is selected, a tilt angle detecting means for detecting a tilt angle of a vehicle body, and a tilt angle detecting means for detecting a tilt angle of the vehicle body. an inclination angle determining means for determining whether the detected inclination angle is greater than or equal to a predetermined value; and the drive state determining means determines that two-wheel drive is not selected, and the inclination angle determining means determines whether the inclination angle is a predetermined value. The present invention is characterized in that it includes a switching means that controls the operation of the friction engagement element to switch the auxiliary transmission from a high speed gear to a low speed gear when the above determination is made. [Operations and Effects of the Invention] With the above configuration, in the vehicle transmission control device of the present invention, the drive state determining means determines that two-wheel drive is not selected, and the tilt angle determining means determines that two-wheel drive is not selected, and the tilt angle determining means determines that two-wheel drive is not selected. If the angle of inclination of the slope on which the vehicle is traveling is determined to be greater than a predetermined angle of inclination, the auxiliary transmission is switched from a high gear to a low gear by controlling the operation of a frictional engagement element. When two-wheel drive is selected, where it is difficult to sufficiently transmit driving force to the road surface, such as on rough terrain, the auxiliary transmission is not switched; at other times, i.e. Only when four-wheel drive is selected, the auxiliary transmission is switched to the gear side depending on the vehicle's inclination angle, so the increased drive power prevents the tires from slipping and provides appropriate drive on steep slopes. power, and on steeply descending slopes, you can obtain appropriate braking force from the engine brake,
It is possible to improve the running ability of the vehicle on rough roads such as steep slopes, uneven terrain, or road conditions such as steep slopes without requiring any operation by the driver. [Example] A control device for a vehicle transmission according to the present invention will be described based on an example shown in the drawings. Figure 1 is a gear train of an automatic transmission for four-wheel drive, Figure 2 is a cross-sectional view of an auxiliary transmission for four-wheel drive, and Figure 3 is a cross-sectional view of an auxiliary transmission for four-wheel drive.
The figure shows a schematic diagram of a motor vehicle with an automatic transmission for four-wheel drive. 10 is a main transmission, which is an automatic transmission with 3 forward speeds and 1 reverse speed; 40 is a 4-wheel drive sub-transmission, which is a 4-wheel drive sub-transmission connected to the rear part of the main transmission 1 (right side in Figure 2); a. 2 is the output shaft of the transmission 1 and the input shaft of the transfer 10; 3 is the input shaft 2;
This is the first output shaft of the transfer that is arranged in series behind (right side in Figure 2). The main transmission 10 includes a fluid torque converter T0, which is a fluid transmission device, and a planetary gear transmission mechanism 10A with three forward stages and one reverse stage. The torque converter T0 consists of a pump 11 connected to the output shaft of the engine, a turbine 13 connected to the output shaft 12 of the torque converter T, a stator 15 connected to a fixed part via a one-way clutch 14,
The output shaft 12 of the torque converter T serves as the input shaft of the planetary gear transmission mechanism 10A. The planetary gear transmission mechanism 10A includes multi-disc clutches C1 and C2, which are frictional engagement elements, and a multi-disc brake.
B1, B2, and B3 and one-way clutch F1 and
F2, a front planetary gear set Pf1, and a rear planetary gear set Pf2. Rear planetary gear set Pf2 is clutch C1
A ring gear 31 is connected to the input shaft 12 via a ring gear 31, a carrier 33 is connected to the output shaft 2 of the planetary gear transmission mechanism 10A, and a brake is connected to the input shaft 12 via a clutch C2.
B1, a sun gear 34 fixed to the transmission case via a brake B2 parallel to the brake B1, and a one-way clutch F1 connected in series with the brake B2;
It consists of a planetary pinion 35 rotatably supported by the carrier 33 and meshed with a sun gear 34 and a ring gear 31. Front planetary gear set Pf1 is brake B3
and a carrier 36 fixed to the transmission case via a one-way clutch F2 parallel to the brake B3, and a sun gear 37 integrally formed with the sun gear 34 of the rear planetary gear set Pf2.
, a ring gear 38 connected to the input shaft 2 , and a planetary pinion 39 rotatably supported by the carrier 36 and meshed with the sun gear 37 and the ring gear 38 . Pf is a planetary gear set of the transfer shaft 40, which includes a sun gear S1 spline-fitted to the rear of the input shaft 2, a planetary gear P that meshes with the sun gear S1, a ring gear R1 that meshes with the planetary gear P, and It consists of a carrier P1 that rotatably holds the planetary gear P and is connected to the tip of the first output shaft 3 of the transfer shaft 40. B4 is a multi-plate brake for engaging the ring gear R1 with the transfer case 94, and B-4 is the cylinder 5 formed inside the transfer case 94.
This is a hydraulic servo for the brake B4, which is composed of a piston 5A mounted in the cylinder 5. C3
is a multi-plate clutch operated by a hydraulic servo C-3 consisting of a cylinder 6 connected to a carrier P1 and a piston 6A installed in the cylinder 6, and is connected to the gear transmission side of the planetary gear set Pf. It is arranged to connect and connect sun gear S1 and carrier P1. C4 is a multi-plate clutch for connecting and disconnecting the first output shaft 3 connected to the carrier P1 and a sleeve 72 connected to one sprocket 71 of a link configuration for driving the other output shaft of the transfer, which will be described later. -4 is a hydraulic servo comprised of a cylinder 7 welded to a sleeve 72 rotatably held within a transfer case 94 and a piston 7A mounted within the cylinder 7. Reference numeral 8 indicates a second output shaft of a transfer that is arranged parallel to the first output shaft 3, and reference numeral 73 indicates a sprocket 7 that is spline-fitted to the sleeve 72.
1. A link mechanism consisting of a sprocket 75 spline-fitted to the second output shaft 8 and a chain 76 stretched between these sprockets. A parking gear 61 is provided around the outer periphery of the hydraulic cylinder 6 of the multi-disc clutch C3, and when the shift lever of the automatic transmission is selected to the parking position, the pawl 62 engages with the parking gear 61 and the first output shaft 3 to be fixed. 110 is a governor valve fixed to the input shaft 2; 90
200 is the automatic transmission oil pan, 200 is the 4-wheel drive transfer clutch C3, C4, and brake.
A hydraulic control device 92 is an oil pan of the hydraulic control device 200 that supplies and discharges hydraulic pressure to and from hydraulic servos C-3, C-4, and B-4 of B4. Kuratsuchi C3,
C4 and brake B4 hydraulic servo C-3, C-
4 and B-4 is guided from an oil pan 90 through a hydraulic control device 200 via a pipe 95 attached to an automatic transmission case 93 and a transfer case 94. This transfer is attached to an automatic transmission T attached to the engine E of the vehicle as shown in A shown in Fig. 3, and the first output shaft 3 is connected to the propeller shaft C for driving the rear wheels. A certain second output shaft 8 is used while being connected to a propeller shaft B for driving the front wheels. During normal driving, line pressure supplied to the hydraulic control device 100 of the automatic transmission is supplied to hydraulic servo C-3 to engage clutch C3, and hydraulic servos B-4 and C-4 are exhausted to brake.
Release B4 and clutch C4. As a result, sun gear S1 and carrier P1 of planetary gear set Pf are connected, and power is transmitted from the input shaft 2 to the first output shaft 3 for driving the rear wheels at a reduction ratio of 1.
Direct wheel drive driving is achieved. At this time, the power from the input shaft 2 is transmitted from the carrier P1 to the first output shaft 3 via the clutch C3 without passing through the gears S1, R1, and P, so no load is applied to the tooth surfaces of each gear. ,
Gear life increases. If 4-wheel drive is required during this 2-wheel drive, the hydraulic servo C-
When line pressure is gradually supplied to C4 and the clutch C4 is smoothly engaged, the first output shaft 3 and the sleeve 72
The power is also transmitted to the front wheels via the link mechanism 73, the second output shaft 8 and the propeller shaft B, and the power is transmitted from the input shaft 2 to the first output shaft 3 for rear wheel drive and the second output shaft 8 for front wheel drive. Directly connected four-wheel drive driving is achieved in which power is transmitted at a reduction ratio of 1. This 4
When it is necessary to increase the output torque, such as when driving on a steep slope while driving with wheel drive, line pressure is gradually supplied to hydraulic servo B-4, and the hydraulic pressure of hydraulic servo C-3 is discharged at an appropriate timing, and brake B4 is gradually applied. To engage the clutch C3 and smoothly release the clutch C3. As a result, sun gear S1 and carrier P1 are released, and ring gear R1 is fixed.
Power is decelerated from the input shaft 2 via the sun gear S1, planetary gear P, and carrier P1, and is transmitted to the first output shaft 3 and the second output shaft 8, resulting in a four-wheel drive deceleration state with large torque. Table 1 shows the engagement and release of brake B4, clutches C3 and C4, and the running conditions of the vehicle.

[Table] In Table 1 and in the following explanation, 2H
is directly connected to 2-wheel drive, 4H is directly connected to 4-wheel drive,
4L indicates a four-wheel drive deceleration state, ○ indicates an engaged state of the friction engagement element, and × indicates a released state. λ of reduction ratio
are the sun gear S1 and ring gear R1 of the planetary gear mechanism
The value of the reduction ratio is calculated as reduction ratio = (1 + λ) / λ = 3.0 when λ is 0.5. Next, a hydraulic control system for a four-wheel drive transmission equipped with a four-wheel drive transmission control system according to the present invention will be explained with reference to FIG. In the figure, 100 is an example of a known hydraulic control device for an automatic transmission with three forward speeds and one reverse speed.
The oil sucked up by the oil pump 102 is
A predetermined oil pressure (line pressure) is set by the oil pressure control valve 103.
The pressure is regulated and the oil is guided to the oil passage 104. The pressure oil led to the oil passage 104 passes through the manual valve 105 to the 1-
2 shift valve 106 and 2-3 shift valve 107. A throttle valve 108 generates oil pressure (throttle pressure) in an oil passage 109 according to the throttle opening. A governor valve 110 generates oil pressure (governor pressure) in an oil passage 111 according to the vehicle speed. 1-2 shift valve 106 and 2-3 shift valve 1
07 controls the opening and closing of oil passages 112, 113, and 114 in relation to the magnitude of the throttle pressure and governor pressure supplied from oil passage 109 and oil passage 111, and controls hydraulic servo C-07 for the clutch and brake.
1, C-2, B-1, B-2, and B-3. In this embodiment, pressure oil is supplied to the hydraulic servo C-1 during the first forward speed, and pressure oil is supplied to the hydraulic servos C-1 and B-2 during the second forward speed.
At 3rd forward speed, hydraulic servos C-1, C-2, B
Pressure oil is supplied to -2, and when moving backward, hydraulic servo C
Pressure oil is supplied to -2 and B-3. Four-wheel drive transfer hydraulic control device 200
are a first solenoid valve 210, a second solenoid valve 220, a switching valve 230, an inhibitor valve 240,
A downshift timing valve 2 provided in the oil drain path 207 for direct coupling engagement pressure via the inhibitor valve 240.
60. Direct coupling friction engagement element, i.e. multi-plate clutch
The first oil passage 20 that connects to the hydraulic servo C-3 of C3
1. Frictional engagement element for deceleration, i.e. multi-disc brake
2nd oil passage 20 that connects to hydraulic servo B-4 of B4
2. Third oil passage 2 that connects to the hydraulic servo C-4 of the four-wheel drive frictional engagement element, that is, the multi-disc clutch C4.
03 A fourth oil passage 204 connecting the predetermined oil chambers of the switching valve 230 and the inhibitor valve 240;
A check valve 310 provided in each of the three oil passages,
320, 330, a line pressure oil passage 104, a first solenoid pressure oil passage 205, and a second solenoid pressure oil passage 206 via orifices 340, 350. The first and second solenoid valves 210 and 220 have moving cores 211 and 221, and solenoid 2, respectively.
12, 222, springs 213, 223, openings 214, 224, and oil drain ports 215, 225. When the solenoids 212, 222 are energized, the moving cores 211, 221 are moved upward in the figure to open the openings 214, 224, and the orifice 34
Pressure oil in oil passages 205 and 206 separated from line pressure oil passage 104 by
Discharge from 25. When the solenoids 212 and 222 are de-energized, the moving cores 211 and 221
are moved downward in the drawing by springs 213 and 223 to close the openings 214 and 224, and the oil passage 20
5, generates high level solenoid oil pressure (line pressure) at 206. The inhibitor pressure 240 is applied to three spools 241, 242 in the order of first, second and third from the bottom in the figure.
243, the first spool 241 has a sleeve-like land 245 with a spring 244 on its lower end.
and two lands 246, 247, a lower end oil chamber 248, a sleeve-shaped land 245 and a land 246.
and an intermediate oil chamber 249, 250 between the land 247,
An oil chamber 251 between the first spool 241 and the second spool 242, an oil chamber 252 between the second spool 242 and the third spool 243, and an upper end oil chamber 253 are formed. In the inhibitor valve 240, when the first spool 241 is set upward in the figure, the lower end oil chamber 248 communicates with the governor pressure oil passage 111 via the oil port 254A of the sleeve-shaped land, and the intermediate oil chamber 2
49 communicates the line pressure oil passage 104 and the second oil passage 202, the intermediate oil chamber 250 communicates the first oil passage 201 and the oil drain port 256, and when the first spool 241 is set downward in the figure, The lower end oil chamber 248 communicates with the oil drain port 254 via the oil port 254A of the sleeve-shaped land, the intermediate oil chamber 249 communicates the second oil passage 202 and the oil drain port 255, and the intermediate oil chamber 250 communicates with the oil drain port 254 through the oil port 254A of the sleeve-shaped land. It communicates with the road 104 and the first oil road 201. Also,
The oil chamber 251 is always in communication with the governor pressure oil passage 111,
The oil chamber 252 is always in communication with the fourth oil passage 204, and the upper end oil chamber 253 is always in communication with the oil passage 206. The switching valve 230 has a spring 23 at the bottom in the figure.
2 on the back and 3 lands provided on the spool 23
1, and from the bottom in the figure are a lower end oil chamber 233, a first intermediate oil chamber 234, a second intermediate oil chamber 235, and an upper end oil chamber 2.
36 are formed. In the switching valve 230, when a high level solenoid pressure is applied to the upper end oil chamber 236 to which the first solenoid pressure oil passage 205 is connected, the spool 231 moves downward in the drawing, and the spool 231 moves downward in the figure, and the spool 231 moves downward in the figure. line pressure oil passage 104 and the third
The oil passage 203 is connected to supply line pressure to the hydraulic servo C-4 of the clutch C4, and the fourth oil passage 204 and the orifice 23 are connected via the first intermediate oil chamber 234
9, the oil chamber 252 of the inhibitor valve is evacuated, and the upper end oil chamber 23
When the solenoid pressure applied to 6 falls to a low level, the spool 231 is moved upward in the drawing by the spring 232, and the line pressure oil passage 104 and the fourth oil passage are connected through the first intermediate oil chamber 234. Line pressure is supplied to the oil chamber 252 of the inhibitor valve,
The third oil passage 203 and the oil drain port 238 are communicated with each other via the second intermediate oil chamber 235, and the pressure of the hydraulic servo C-4 is exhausted. The downshift timing valve 260 has a spool 261 with a spring 262 mounted on its back in the lower part of the figure, and two lands.
5 is formed. The downshift timing valve 260 has a lower end oil chamber 263 that is always connected to the deceleration oil passage 2.
02, the upper end oil chamber 265 is always in communication with the line pressure oil passage 104, and the middle oil chamber 264 is in constant communication with the oil drain passage 207 and an oil drain port 266 provided with an orifice 267 for slowly draining pressure. At the same time, when the spool 261 is set upward in the figure, it also communicates with an oil drain port 268 in order to quickly discharge pressure. The spool 261 is set upward in the figure when the line pressure applied to the upper end oil chamber 265 is lower than the set value (that is, the throttle opening is small) and is weaker than the spring load of the spring 262, or when the line pressure applied to the upper end oil chamber 265 is lower than the spring load of the spring 262. This is when the engagement pressure of multi-disc brake B4 is introduced. Operate the manual shift such as the changeover lever or changeover switch installed in the driver's seat to select H2, H4,
Alternatively, when the L4 range is set, the first and second solenoid valves 210 and 220 are activated as shown in Table 2 according to the comparison result of the manual shift setting range, the detected tilt angle value, and the detected tilt angle value by the electronic control device (to be described later).
Each hydraulic servo B-4, C-3, C- is controlled ON and OFF from the transfer hydraulic control device 200.
Each frictional engagement element is actuated by the hydraulic oil selectively sent to the transfer gear 40, and the transfer gear 40 is shifted to each shift state (2H, 4H, or 4L). Also, as described above, due to the hydraulic circuit configuration, the first solenoid valve 2
10 is turned on, the second solenoid valve 220
Transfer is set to H2 regardless of ON or OFF. The operation of the solenoid valves 210 and 220 is as shown in Table 2. ON means energized, OFF means not energized. Furthermore, A is a manual shift of transfer 40,
B is the gear shift state of the transfer shaft 40.

[Table] The operation of the transfer manual shift in each setting range is explained. (A) When the manual shift is in the H2 range, the first solenoid valve 210 → ON and the second solenoid valve 220 → OFF, so the line pressure is guided from the oil passage 104 through the orifice 340 to the oil passage 205, but is not energized. Since the oil is drained by the first solenoid valve 210 and is not output to the upper end oil chamber 236,
In the switching valve 230, the spool 231 is set upward in the figure by a spring 232, and line pressure is applied to the oil chamber 252 through the oil passage 104, the oil chamber 234, and the fourth oil passage 204, and the second
The spool 242 and the first spool 241 are set downward in the drawing. Therefore, the line pressure is introduced to the hydraulic servo C-3 of the clutch C3 via the oil passage 104, the oil chamber 250, the first oil passage 201 and the check valve 310. Also, hydraulic servo C-
The oil pressure of 4 and B-4 are respectively drained from the oil drain port 238.
and drained from 255. Therefore, the transfer gear 40 becomes 2H (two-wheel drive directly connected state). (B) When the manual shift is in the H4 range and the tilt angle is below the set value, the first solenoid valve 210 → OFF and the second solenoid valve 220 → OFF, so the line pressure flows from the oil passage 104 through the orifice 340. However, since the first solenoid valve 210 is not energized, it is output to the upper end oil chamber 236, and the spool 231 of the switching valve 230 is set at the lower side in the figure. Therefore, the line pressure is in the oil passage 104 and the second intermediate oil chamber 23.
5. The oil is introduced into the hydraulic servo C-4 of the clutch C4 via the third oil passage 203 and the check valve 330. On the other hand, the line pressure is also guided from the oil passage 104 through the orifice 350 to the oil passage 206.
Since the second solenoid valve 220 is de-energized,
Output to the upper end oil chamber 253 and inhibit valve 240
are the third, second, and first spools 243, 242,
241 is set at the bottom in the figure. Line pressure is therefore introduced into the clutch hydraulic servo C-4. Also, the oil pressure of hydraulic servo B-4 is at oil drain port 2.
Drained from 55. Therefore, the transfer 10 becomes 4H (four-wheel drive directly connected state). (C) When the manual shift is in the L4 range or H4 range and the tilt angle is above the set value and the vehicle speed is above the set value, the first solenoid valve 210 → OFF and the second solenoid valve 220 → ON, so the line The pressure is guided from the oil passage 104 through the orifice 340 to the oil passage 205, but since the first solenoid valve 210 is de-energized, it is input to the upper end oil chamber 236, and the switching valve 230 is set so that the spool 231 is positioned downward in the figure. Ru. Therefore, line pressure is controlled by hydraulic servo C-4 of clutch C4.
will be introduced in On the other hand, the line pressure is also guided from the oil passage 104 through the orifice 350 to the oil passage 206, but is drained by the energized solenoid valve 220 and is not input to the upper end oil chamber 253 of the inhibitor valve 240. Also, no line pressure is input to the oil chamber 252. Here, since the governor pressure is input to the oil chamber 251, the second and third spools 242 and 243 move upward in the figure, and since the governor pressure is above the set value, the spring 24
In order to overcome the spring load of 4, the first spool 241 is set downward in the drawing. Line pressure is therefore introduced into hydraulic servo C-3 of clutch C3.
Further, the oil pressure of the hydraulic servo B-4 is drained from the oil drain port 255. Therefore, transfer 4
0 is 4H (four-wheel drive direct connection state). (D) When the manual shift is in the L4 or H4 range and the tilt angle is above the set value and the vehicle speed is below the set value, the first solenoid valve 210 → OFF and the second solenoid valve 220 → ON, so the line pressure is The oil is guided from the oil passage 104 through the orifice 340 to the oil passage 205, but since the first solenoid valve 210 is not energized, the oil is input to the upper end oil chamber 236, and the switching valve 230 is set so that the spool 231 is positioned downward in the figure. Therefore, line pressure is controlled by hydraulic servo C-4 of clutch C4.
will be introduced in On the other hand, line pressure is also guided from the oil passage 104 through the orifice 350 to 206, but is drained by the energized solenoid valve 220 and is not input to the upper end oil chamber 253 of the inhibitor valve 240. Also, line pressure is not input to the oil chamber 252. Since the governor pressure is input to the oil chamber 251 here, the second and third spools 24
2, 243 moves upward in the figure, and since the governor pressure is below the set value, the first spool 241 is set upward in the figure by the spring load of the spring 244, and the first spool 241 is moved upward in the figure through the oil port 254A of the sleeve. Governor pressure is input to 248. Therefore, the line pressure is
The oil is introduced into the hydraulic servo B-4 of the multi-disc brake B4 via the oil passage 202 and the check valve 320. In addition, the oil pressure of the hydraulic servo C-3 is controlled by a direct connection oil passage 201, a second intermediate oil chamber 250, a drain oil passage 207,
The oil is drained from oil drain ports 266 and 268 via an oil chamber 264 located in the middle of the doubt shift timing valve 260. Therefore, transfer 40 is
It becomes 4L (four-wheel drive deceleration state). Also, the first spool 241 of the inhibitor valve 240
Since the areas of the upper and lower end faces facing the oil chamber 251 and the lower end oil chamber 248 are the same, when the governor pressure is introduced into both the oil chamber 251 and the lower end oil chamber 248 by moving upward in the figure, the governor pressure (Vehicle speed) does not move downward in the figure even if the speed increases, and unless the manual shift is set to the H2 range or H4 range and line pressure is introduced into the oil chamber 252 or the upper end oil chamber 253,
Due to the spring load of the spring 244, it remains set upward in the drawing. Therefore, the manual shift is set to the L4 range, and once the vehicle speed (governor pressure) falls below a predetermined value and reaches 4L, 4L is maintained even if the vehicle speed (governor pressure) increases. An electronic control device 500 relating to a control device for a four-wheel drive transmission of a vehicle according to the present invention will be explained based on the block diagram shown in FIG. The electronic control device 500 uses a gyrometer 501, which is a vehicle body tilt angle detection means, to determine both the pitch angle (θ), which is the front and rear tilt angle of the vehicle, and the rolling angle (φ), which is the left and right tilt angle of the vehicle (or the pitch angle). (θ) only) signal, the manual shift switch 502 installed in the driver's seat switches to H2 range.
H4 range, L4 range automatic selection switch
Input port 511 that inputs a set position signal only for the AUTOH4 range, output port 512 that outputs to the first solenoid valve 210 and second solenoid valve 220 in the hydraulic control device 200, central processing unit
It consists of a CPU, a read-only memory ROM that stores preset tilt angle settings, and a random access memory RAM. FIG. 6 shows a first embodiment of an operation flowchart of the electronic control device 500. First, the initial value F is set to 0 (601), a pitch angle ( ) signal is inputted from the gyrometer 501 and a shift switch signal is inputted from the manual shift switch 502 (602), and the current manual shift switch 502 is set to the H2 range in the drive state determining means. 603. When the H2 range is set, the solenoid valve 210 is set to ON and the solenoid valve 220 is set to OFF so that the gear is set to 2H, and the vehicle is run for 2H (604), and then 613
Proceed to. When the H2 range is not set, determine whether the L4 range is set or not 605;
When the L4 range is set, the solenoid valve 210 is set to OFF and the solenoid valve 220 is set to ON so that the gear stage is 4L, and the hydraulic control device 2
00 governor pressure is below the set value (below the set vehicle speed)
At this time, the vehicle runs 4L and proceeds to 606 and then to 613. When it is not in the L4 range, it is determined whether the manual shift switch 502 is set to AUTO or not (607), and when it is not AUTO, the solenoid valves 210 and 220 are both set to OFF so that the gear position is 4H, and the vehicle is driven in 4H. Then, the initial value F is set to 1 (613). This initial value F prevents the operation from being undetermined and becoming unstable when the pitch angle () is in the hysteresis region (FIG. 9A) at the time of the first determination. This allows the gear position to be changed in the hysteresis region at the time of the first judgment.
It will be 4H. When the manual shift switch 502 is set to AUTO, the pitch angle () setting value (γ) (δ)
(FIG. 9) is read from the ROM (609), and the tilt angle determining means determines whether or not the pitch angle (θ) is larger than the set value (γ) (610). If it is, the process proceeds to the switching means 606. When the pitch angle () is smaller than the set value (γ), it is determined whether the pitch angle () is smaller than the set value (δ), and 611 <δ
If not, proceed to 608. <δ, the current gear stage is maintained, and then it is determined whether the initial value F is 1 or not (612), and when F=1, the process proceeds to 613 and F=1
If not, proceed to 608. 60 after doing 613
Repeat steps 2 onwards. FIG. 7 shows a second embodiment of the operation flowchart of the electronic control device 500. First, the initial value F is set to 0 (701), a pitch angle ( ) signal, a rolling angle (φ) signal from the gyrometer 501, and a shift switch signal from the manual shift switch 502 are input (702), and the current manual shift is determined by the drive state determining means. switch 502
Determine whether or not is set to H2 range 7
03.When set to H2 range, the gear position is
The solenoid valve 210 is set to ON and the solenoid valve 220 is set to OFF for 2H, and the vehicle travels for 2H (704), and then proceeds to 716. When the H2 range is not set, it is determined whether the L4 range is set or not. When the L4 range is set, the solenoid valve 210 is turned OFF and the solenoid valve 220 is turned ON so that the gear position is 4L. Further, when the governor pressure of the hydraulic control device 200 is less than the set value (less than the set vehicle speed), the vehicle travels 4L and then proceeds to 706 and then to 716. When not in the L4 range, it is determined whether the manual shift switch 502 is set to AUTO 707, and the manual shift switch 502 is set to AUTO.
When the vehicle is not in 4H, both solenoid valves 210 and 220 are set to OFF so that the gear is in 4H.
The vehicle is run (708), and the initial value F is set to 1 (716). When the manual shift switch 502 is set to AUTO, the pitch angle () setting value (γ) (δ)
(Fig. 10) is read from the ROM 710, and the pitch angle (θ) is set to the set value (γ) in the inclination angle determining means.
It is determined whether or not the value is larger than 711, and when θ>γ, the process proceeds to switching means 706. If not >γ, it is determined whether the rolling angle (φ) is larger than the set value (γ) at 712, and if φ>γ, the process proceeds to 706. φ>
When it is not γ, it is determined whether the pitch angle () is smaller than the set value (δ) 713, and when it is not <δ, the current gear is maintained, and then the initial value F is set to 1.
It is determined 715 whether F=1, the process advances to 716, and if F=1, the process advances to 708. When <δ, it is determined whether the rolling angle (φ) is smaller than the set value (δ) or not (714), and when φ<δ, the process proceeds to 708, and when φ<δ does not, the process proceeds to 715. After performing step 716, steps 702 and subsequent steps are repeated again. FIG. 8 shows a third embodiment of the operation flowchart of the electronic control device 500. First, the initial value F is set to 0 (801), the pitch angle ( ) signal from the gyrometer 501, the rolling angle signal (φ), and the shift switch signal from the manual shift switch 502 are inputted (802), and the current manual shift switch is determined by the drive state determining means. 502 is
Determine whether it is set to H2 range or not 80
3. When set to H2 range, the gear is 2H
The solenoid valve 210 is set to ON and the solenoid valve 220 is set to OFF so that the vehicle runs for 2 hours at 804, and then proceeds to 813. When the H2 range is not set, the solenoid valve 21 determines whether the L4 range is set or not, and when the L4 range is set, the solenoid valve 21
Set 0 to OFF, solenoid valve 220 to ON,
Furthermore, when the governor pressure of the hydraulic control device 200 is below the set value (below the set vehicle speed), the vehicle is driven 4L and 8
06, then proceed to 813. When it is not in the L4 range, it is determined whether the manual shift switch 502 is set to AUTO 807, and when it is not AUTO, the solenoid valve 21 is set so that the gear is set to 4H.
Set both 0 and 220 to OFF, run the vehicle for 4 hours 808, and then set the initial value F to 1 81
3. When the manual shift switch 502 is set to AUTO, the tilt angle setting values (α) (β) (11th
) is read from the ROM 809, and the inclination angle determining means determines whether the pitch angle (θ) + rolling angle (φ) is larger than the set value (α) 810;
When θ+φ>α, the process proceeds to switching means 806. +φ
>α, it is determined whether the pitch angle ()+rolling angle (φ) is smaller than the set value (β) (step 811); if +φ<β, the process proceeds to step 808.
When +φ<β, the current gear stage is maintained, and then it is determined whether the initial value F is 1 or not (812), and when F=1, the process proceeds to 813, and when F=1, the process proceeds to 808. After performing step 813, steps 802 and subsequent steps are repeated again. Although a gyrometer is used as the inclination angle sensor in this embodiment, other inclination angle meters may be used.

[Brief explanation of the drawing]

Fig. 1 is a skeletal diagram of a transfer related to the control device for a vehicle transmission of the present invention and a known automatic transmission, Fig. 2 is a sectional view thereof, and Fig. 3 is a schematic diagram showing a power transmission system of a vehicle. , FIG. 4 is a circuit diagram of a four-wheel drive transfer hydraulic control device according to the vehicle transmission control device of the present invention when applied to an automatic transmission with three forward speeds and one reverse speed. FIG. 6 is a block diagram of the control device for a vehicle transmission according to the present invention, FIG. FIG. 8 is an operation flowchart of a second embodiment of an electronic control device for a control device for a vehicle transmission, and FIG. 8 is an operation flowchart for a third embodiment of the electronic control device for a control device for a vehicle transmission of the present invention. , 9, 10, and 11 are shift diagrams relating to the control device for a vehicle transmission according to the present invention. In the figure, 5...Multi-disc brake which is a frictional engagement element for deceleration, 7...Multi-disc clutch which is a frictional engagement element for direct coupling, 8...Multi-disc clutch which is a frictional engagement element for four-wheel drive, B-4, C-3, C-4...Hydraulic servo, 10...Main transmission, 40...4-wheel drive transfer, 100...4-speed automatic transmission hydraulic control device, 104...Line Pressure oil path, 105...Manual valve, 111...Governor pressure oil path, 200...
…Four-wheel drive transfer hydraulic control device, 20
1...First oil passage, 202...Second oil passage, 203...
...Third oil passage, 204...Fourth oil passage, 210...First solenoid valve, 220...Solenoid valve, 23
0...Switching valve, 240...Inhibitor valve, 24
1...first spool, 242...second spool,
243...Third spool, 252...Oil chamber which is a predetermined oil chamber of the inhibitor valve, 500...Electronic control device, 501...Gyrometer (inclination angle detection means), 502...Manual shift switch, 603,
603, 803... Drive state determining means, 606,
706, 806... switching means, 610, 711,
810...Inclination angle determination means.

Claims (1)

[Scope of Claims] 1. A main transmission having a plurality of gears, a sub-transmission having a high-speed gear and a low-speed gear that can be switched by operating a frictional engagement element, and a high-speed gear and a low-speed gear of the sub-transmission. A control device for a vehicle transmission capable of switching between two-wheel drive and four-wheel drive, comprising a control device that controls the operation of the frictional engagement element for switching between two-wheel drive and four-wheel drive. drive state determining means for determining whether drive is selected; tilt angle detecting means for detecting a tilt angle of the vehicle body; and determining whether the tilt angle detected by the tilt angle detecting means is equal to or greater than a predetermined value. operation of the friction engagement element when the tilt angle determining means and the drive state determining means determine that two-wheel drive is not selected, and the tilt angle determining means determines that the tilt angle is a predetermined value or more; A control device for a vehicle transmission, comprising a switching means for controlling the sub-transmission to switch the sub-transmission from a high speed gear to a low speed gear. 2. The control device for a vehicle transmission according to claim 1, wherein the vehicle body inclination angle detection means detects a pitch angle that is a longitudinal inclination angle of the vehicle. 3. Control of a vehicle transmission according to claim 1, wherein the vehicle body tilt angle detection means detects a rolling angle, which is a left and right tilt angle of the vehicle, and the pitch angle. Device.