JPS6144031A - Control device for vehicle four wheel speed change gear unit - Google Patents

Abstract

PURPOSE:To simplify a complicated power transmission path, by estimating that a four wheel drive operation is required when the vehicle speed is lower than a predetermined value while the throttle valve opening degree is small so that a change-over mechanism is changed over from its four wheel drive condition to its two wheel drive condition in accordance with a predetermined change-over diagram. CONSTITUTION:In a control device for a vehicle four wheel speed change gear unit, in which solenoid valves 210, 220 are turned on and off, respectively, upon two wheel drive operation while both solenoid valves 210, 220 are turned off upon four wheel drive operation, upon operation of an engine E, an electronic control device 200 receives outputs from an output shaft rotational speed sensor 501, a throttle valve opening degree sensor 502 and a transfer shift lever position sensor 504. If a transfer shift lever is set at its H4 range, a change-over diagram having a change-over area with which the speed change gear is set to H2 when the outputs from the sensors 510, 520 are predetermined values, is read from a ROM. Further, when it is determined that the operation is in a change-over area in which the gear is changed-over to H2, the solenoid valves 210, 220 are turned on an off, respectively, to change-over the gear into the H2 range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a four-wheel drive transmission for a vehicle that automatically switches from a four-wheel drive state to a two-wheel drive state.

[Prior Art] Generally, a sub-transmission for four-wheel drive is capable of switching between a two-wheel drive state and a four-wheel drive state, and in order to achieve the two-wheel drive state and the four-wheel drive state, the driver has to operate the shift lever according to his will. - or is set so that the desired driving state can be obtained by operating the switch.

[Problems to be solved by the invention] Conventionally, four-wheel drive systems capable of switching between two-wheel drive state and four-wheel drive state
If a vehicle equipped with a wheel drive transmission does not have a center differential gear and makes a small turn while driving in four-wheel drive mode, a difference in rotational speed will occur between the front and rear wheels due to the difference in turning radius. 1 torsion between the front and rear drive wheels, 1 rotation to 0, running performance 0 deterioration, tire wear,
Problems such as durability arise (Tie 1 - Cornering brake phenomenon). For this reason, in four-wheel drive mode, it is difficult to turn with a small radius, so we switch to two-wheel drive mode (1
When turned to h, it is easier to drive.

The present invention automatically detects a state where four-wheel drive is not required and switches from four-wheel drive to two-wheel drive.
The purpose of the present invention is to provide a control device for a four-wheel drive transmission for a vehicle, which simplifies a complicated power transmission path, improves power transmission efficiency, and improves fuel efficiency.

[Means for Solving the Problems 1] A control device for a four-wheel drive transmission for a vehicle according to the present invention comprises a transmission, a two-wheel drive and four-wheel drive capable of switching between a two-wheel drive state and a four-wheel drive state. In a control device for a four-wheel drive transmission line for a vehicle, which includes a switching mechanism and a control device for controlling the 11 switching mechanisms, the illumination device includes a means for detecting a speed, and an engine throttle control device. means for detecting an opening degree, and the switching mechanism is configured to switch from a four-wheel drive state to a two-wheel drive state based on a switching diagram corresponding to a preset vehicle speed and throttle opening degree, and further comprises a transmission. , a 2-wheel drive/4-wheel drive steering mechanism that can switch between a 2-wheel drive state and a 4-wheel drive state, and the switching mechanism! In the control device for a vehicle four-wheel drive transmission, the control device includes a control device that controls Ij.
The device includes a first means for detecting vehicle speed, a second means for detecting vehicle speed, and a means for detecting a throttle opening of the engine.
A means for comparing vehicle speed signals from the first vehicle speed detecting means and the second vehicle speed detecting means is provided, and when the comparison result satisfies a preset condition, it corresponds to a preset vehicle speed and throttle opening. switching the switching mechanism from a four-wheel drive state to a two-wheel drive state based on the switching diagram obtained;
composition.

[Effect] The present invention will be described in detail.

A state in which the vehicle speed is lower than the set value and the throttle opening is small is set as a state in which 4-wheel drive is not required, and the switching mechanism is set to 4-wheel drive based on the switching diagram corresponding to the preset vehicle speed and throttle opening. By switching from a drive state to a two-wheel drive state, a complicated power transmission path is simplified.

[Effects of the Invention] As described above, the control device for a four-wheel drive transmission for a vehicle according to the present invention has the following effects.

By automatically detecting when 4-wheel drive is not required and switching the sub-transmission from 4-wheel drive to 2-wheel drive, complex 4T power transmission on light roads is simplified and power transmission efficiency is improved. This will improve fuel efficiency.

[Example] Next, the present invention will be explained based on embodiments shown in the drawings.

Figure 1 shows a four-wheel drive automatic transmission, and Figure 2 shows its gear train. Reference numeral 10 indicates a three-speed forward and one-speed reverse automatic transmission which is a main transmission, and 404 indicates a four-wheel drive transfer connected to the output shaft 32 of the planetary gear transmission of the automatic transmission 10.

The automatic transmission 10 includes a hydraulic torque converter T and a planetary gear transmission mechanism 10A with three forward speeds and one reverse speed.

The torque converter T consists of a pump 11.1 connected to the output shaft of the engine, a turbine 13 connected to the output shaft 12 of the engine, and a stator 15 connected to a fixed part via a one-way clutch 14. The output shaft 12 of the torque converter T is aligned with the input shaft 12 of the planetary gear transmission mechanism 10A.

The planetary gear transmission mechanism 10A includes multi-disc clutches ClF3 and C2, which are frictional engagement elements, multi-disc brakes B1, B2 and B3, one-way clutches F1 and F2, a front planetary gear set P1, and a rear planetary gear set. It consists of P2.

The rear planetary gear set P2 includes a ring gear 31 connected to the input shaft (12) via a clutch C1,
A carrier 33 connected to the output shaft 32 of the planetary gear transmission mechanism 10A and the input shaft (12) via the clutch C2.
A sun gear 34 is connected to the transmission case and is fixed to the transmission case via a brake B1, brakes [3, 2 parallel to the brake B1, and a one-way latch F1 directly connected to the brake B2, and the carrier 33. It is rotatably supported by a sun gear 34 and a planetary pinion 35 meshed with a ring gear 31.

The front planetary gear set P1 is integrally formed with a gear rear 36 fixed to the transmission case via a brake B3 and a one-layer latch F2 parallel to the brake B3, and a sun gear 34 of the rear planetary gear set P2. It consists of a sun gear 37, a ring gear 38 connected to the output shaft 32, and a planetary pinion 39 rotatably supported by the gear/rear 36 and meshed with the sun gear 37 and the ring gear 38.

This four-wheel drive automatic transmission is operated by a hydraulic control device 100 of a four-speed automatic transmission 10 shown in FIG. Clutches and brakes are selectively engaged or released, resulting in three automatic forward speeds and one rapid speed change using only manual shifting.

A shift 1 lever (not shown) provided in the driver's seat for manual valve drive of the hydraulic control device 100 is used for P (parking), R (reverse), neutral (N), D (drive), and 2 (second shift). ), L (low) ranges, and this shift position SP and the gear stages 4th speed (4), 3rd speed (3), 2nd speed (2), and 1st speed (1 ), and the operational relationships of the clutch and brake are shown in Table 1.

In Table 1, O indicates engagement of the friction engagement element, × indicates release, F (free) indicates free rotation of the one-way clutch, and L (lock) indicates engagement of the one-way clutch.

Table 1 Reference numeral 100 in the figure is an example of a hydraulic control device for a known automatic transmission with three forward speeds and one reverse speed. The pressure is regulated and the oil is guided to the oil passage 104. The pressure oil led to the oil passage 104 is led to the 1-2 shift valve 106 and the 2-3 shift valve 1.7 via the manual valve 105.

A throttle valve 108 generates oil pressure (throttle pressure) in an oil passage 109 according to the throttle opening degree.

110 is a governor valve, which has oil pressure (governor pressure) depending on the vehicle speed.
is occurring in the oil passage 111.

The 1-2 shift valve 106 and the 2-3 shift valve 107 are
Oil passage 112.11 in relation to the magnitude of the throttle pressure and governor pressure supplied from oil passage 109 and oil passage 111.
3.114, and controls the supply and discharge of pressure oil to the clutch and brake hydraulic servos C-1, C-2, Bl, B-2, and 3-3.

In this embodiment, at the first forward speed, the hydraulic servo C
Pressure oil is supplied to -1, and at the second forward speed, hydraulic servo C
Pressure oil is supplied to -1 and B-2, and during third forward speed, pressure oil is supplied to hydraulic servos C-1, C-2, and B-2, and during reverse, hydraulic servos C, -2, and B-3. Pressure oil is supplied to

The manual valve 105 is connected to a shift lever provided on the driver's seat, and is manually operated to change the settings between P (parking), R (reverse), and N (reverse) depending on the range of the shift lever.
Neutral), D (drive), 2 (second), L
(Low) Move to W8.

The transfer shown in Figure 1? Reference numeral 40 denotes a clutch C3, which is a friction engagement element, a brake B4, and a clutch C4, which is a two-wheel drive four-wheel drive switching device I14'c, as shown in FIG.
and the output shafts 32 of the front and rear planetary gear sets P1 and P2 are used as input shafts, and the gapeau valve 110 fixed to the input shafts (32) is arranged in series with the input shafts (32). a first output shaft 42, a planetary gearlet PI disposed between the input shaft (32) and the first output shaft 42, and a four-wheel drive sleeve rotatably fitted onto the first output shaft 42. 51, a second output shaft 52 parallel to the input shaft (32) (attached in the opposite direction to the parallel first output shaft 42); It has a transmission W153.The planetary gear hit P[ is a sun gear 44 spline-fitted to the end of the input shaft (32), a planetary binion 45 that meshes with the sun gear 44, and a planetary binion 45 that meshes with the planetary binion 45. Link gear 46 and planetary binion 45
The key 1! is rotatably held and connected to the tip of the first output shaft 42 of the transfer 40! Consists of rear 47.

In this embodiment, the brake 84 is a multi-disc friction brake for engaging the ring gear 46 with the transfer case 48 , and the brake 84 is a multi-disc friction brake that engages the ring gear 46 with the transfer case 48 .
and the piston 49P installed in the cylinder 49.
It is operated by a hydraulic servo B-4. Clutch C3 is a 4-speed automatic transmission 1 with planetary gear set Pf.
It is arranged on the 0 side and connects and disconnects the sun gear 44 and the carrier 47, and includes a cylinder 50 connected to the carrier 47 and a piston 50P installed in the cylinder 50.
It is operated by a hydraulic servo C-3 consisting of. Clutch C4 is a first output shaft 42 connected to a carrier 41.
and a sleeve 51 connected to one sprocket 56 of a transmission device 53 for driving the second output shaft 52 of the transfer 40, and is rotatably supported by the transfer case 48. cylinder 58 and the 84Ei screw inside the cylinder 58]・
It is operated by a hydraulic servo C-4 consisting of a cylinder 58P. The transmission device 53 includes subblocks i to 56 that are spline-fitted to the sleeve 51, a sprocket 55 that is spline-fitted to the second prong shaft 52, and f and r-rings 57 stretched between these subblocks 1 to 1. It roars.

A parking gear 59 is provided around the outer circumferential side of the cylinder 50 of the hydraulic servo C-3. automatic transmission 10
When the shift lever is set to the parking position, the pawl engages the parking pawl (not shown) and the first output shaft 42
to be fixed.

60 is the clutch C3, C of the four-wheel drive transfer 40
A transfer control device 20 that supplies and discharges hydraulic pressure to and from cylinders C-3, C-4, and 8-4.
0 is the transfer/valve body, and 61 is its oil pan. Pressure oil supplied to hydraulic servos C-3, C-4 and B-4 of clutches C3 and C4 and brake B4 is connected to transmission case 62 and transfer case 48 by oil pan 62A fastened to transmission case 62. The transformer 77 is guided through the vibro 4 to the transfer valve body 60 in which the control device 200 is installed.

This transfer is carried out by the vehicle's engine 1 as shown in FIG.
11E, and the first
The output shaft 42 is connected to the propeller shaft C for driving the rear wheels, and the second output shaft 52, which is the other output shaft, is connected to the propeller shaft B for driving the front wheels.

During normal driving, line pressure supplied to the hydraulic control device of the automatic transmission is supplied to hydraulic servo C-3 to engage clutch C3, and pressure is discharged from hydraulic servos B-46 and C-4 to control brake B4 and clarifier. : Chi C4
to release. As a result, planetary gear set Pf
The sun gear 44 and the carrier 47 are connected, and power is transmitted from the input shaft (32) to the first output shaft 42 at a reduction ratio of 1, so that two-wheel drive running with only the rear wheels is achieved. At this time, the input shaft (
32) is transmitted from the carrier 47 to the first output shaft 42 via the clutch C3 without going through the sun gear 44, planetary anion 45, or ring gear 4G.
No load is applied to the south side of each gear, increasing the life of the gears. When four-wheel drive driving becomes necessary during this two-wheel drive driving, use the shift lever (not shown) installed on the driver's seat to manually shift l-L, and use the hydraulic servo C of the trans seven-door control device 200.
-4 is gradually supplied with line pressure to smoothly engage the clutch C4, the first output shaft 42 and the sleeve 51 are connected, and the transmission B position 53, the second output shaft 52 and the propeller shaft B (the third The power is also transmitted to the front wheels via the input shaft (32) to the first output horn shaft 42 and the second output shaft 52 at a reduction ratio of 1, and the 4-wheel drive directly coupled driving state ( high-speed four-wheel drive). During this 4-wheel drive driving, when an increase in output torque is required such as on a steep slope, the hydraulic pressure to the hydraulic servo is controlled by a manual switch using the inhibitor valve 240, which is a switching valve between high-speed 4-wheel drive state and low-speed 4-wheel drive state. The downshift timing valve 260 is activated to gradually supply line pressure to the hydraulic servo B-4, and at the same time, the hydraulic pressure is supplied and discharged from the hydraulic servo C-3 at appropriate timing, and the brake B4 is gradually engaged, and the clutch and C3 are activated. be released smoothly.

As a result, the sun gear 44 and the carrier 47 are released, the ring gear 46 is fixed, and the power is transferred to the input shaft (32
) through the sun gear 44, planetary binion 45, and carrier 47! The torque is transmitted to the No. 11 output shaft 42 and the second output shaft 52, and a four-wheel drive deceleration traveling state (low-speed four-wheel drive state ta) with large torque is obtained.

Table 2 shows the running state of the transfer 40 and the operating states of the brake B4 and clutches C3 and C4.

Table 2 In Table 2, ◯ indicates the engaged state of the friction engagement element, and × indicates the released state. For the reduction ratio (3.0 in the example), the ratio of the number of teeth between the sun gear 44 and the ring gear 46 of the planetary gear mechanism is λ,
Reduction ratio -(1+λ)/λ when tooth ratio λ is 0.5
-3.0.

The four-wheel drive transfer control device 200 includes a first solenoid valve 210, a second solenoid valve 220, and a switching valve 2.
30, an inhibitor valve 240, a downshift timing valve 260 provided in the oil drain path 207 for direct coupling engagement pressure via the inhibitor valve 240, and a hydraulic turbo C-3 of the direct coupling friction engagement element, that is, the multi-disc clutch C3. 1st oil road 2 to communicate
01, Hydraulic servo of the multi-disc brake B4, which is a frictional engagement element for deceleration [2nd oil passage 202 connected to 3-4. 4, the third oil passage 203 and the switching valve 230
and a fourth oil passage 2 that communicates with a predetermined oil chamber of the inhibitor valve 240.
04, check valves 310, 320, and 330 installed in the 1.2.3 oil passages, respectively, and line pressure oil passage 104
and an oil passage 205 for the first solenoid pressure and an oil passage 206 for the second solenoid pressure via orifices 340 and 350.

The 1.2 solenoid valves 210 and 220 have a moving core 211.221 and a solenoid 212.222, respectively.
, spring 213.223, opening 214.224,
It consists of oil drain ports 215 and 225, and a solenoid 212.
222 is energized, the moving core 211.221 is moved upward in the drawing to open the opening 214.224, and the pressure oil in the oil passage 205.206 separated from the line pressure oil passage 104 by the orifice 340.350 is drained to the oil drain port 215. .225
Discharge 1 more. Solenoid 21
When moving core 211.222 is de-energized, moving core 211.222 is de-energized.
221 is moved downward in the figure by springs 213.223 to close the openings 214.224 and open the oil passages 205.20.
6, generates high level solenoid oil pressure (line pressure).

The inhibitor valves 240 have three first and second
, spools 241 , 242 , 243 in a third order, the first spool 241 has a sleeve-shaped land 245 with a spring 244 loaded at the lower end and two lands 246 .
, 247, a lower end oil chamber 248, and a sleeve-shaped land 2.
45 and the intermediate oil chamber 24 between the land 246 and the land 247
9.250, first spool 241 and second spool 24
An oil chamber 251 between the second spool 242 and the third spool 243, an oil chamber 252 between the second spool 242 and the third spool 243, and an upper end oil chamber 253 are formed. The inhibitor valve 240 is connected to the first spool 241
is set upward in the figure, the lower end oil chamber 248 connects to the governor pressure oil passage 11 through the curve 254A of the sleeve-shaped land.
1, the intermediate oil chamber 249 communicates the line pressure oil passage 104 and the second oil passage 202, and the intermediate oil chamber 250 communicates with the first oil passage 20.
1 and the oil drain port 266, and when the first susol 241 is set downward in the figure, the lower end oil chamber 248 communicates with the oil drain port 254 via the curve 254A of the sleeve-shaped land, and the intermediate oil chamber 249 communicates with the oil drain port 266. The second Ga oil passage 202 communicates with the oil drain port 255, and the intermediate oil chamber 250 communicates the line pressure oil passage 104 with the first oil passage 201. Further, the oil chamber 251 is always in communication with the governor pressure oil passage 111, and the oil chamber 252 is always in communication with the fourth oil passage 20.
4, and the upper end oil chamber 253 is always in communication with the oil passage 206.

The switching valve 230 has a spool 231 with a spring 232 installed at the bottom in the figure and three lands, and includes, from the bottom in the figure, a lower end chamber A 233, a first intermediate oil chamber 234, a second intermediate oil chamber 235, An upper end oil chamber 236 is 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 third oil passage 2
03 is connected, line pressure is supplied to hydraulic servo C-4 of clutch C4, and line pressure is supplied to hydraulic servo C-4 of clutch C4.
The oil passage 204 and the oil drain port 237 equipped with the orifice 239 are communicated, and the oil chamber 252 of the inhibitor valve is drained. When the solenoid applied to the upper oil chamber 236 is turned to the low level, the spring 232 closes the spool. 231
moves upward in the figure, the line pressure oil passage 104 and the fourth oil passage 204 are connected via the first intermediate oil passage 234, line pressure is supplied to the oil chamber 252 of the inhibitor valve, and the line pressure is supplied to the oil chamber 252 of the inhibitor valve. 235, the first third oil passage 203 and the oil drain port 238 are communicated with each other, and the pressure of the hydraulic servo C-4 is exhausted.

The downshift timing valve 260 has a spool 261 with a spring 262 installed at the lower side in the figure and two lands. A chamber 265 is formed. In the downshift timing valve 260, a lower end oil chamber 263 is always in communication with the deceleration oil passage 202, an upper end oil chamber 265 is always in communication with the line pressure oil passage 104, and an intermediate oil chamber 264 is always in communication with the drain oil passage 207 and It communicates with an oil drain port 266 provided with an A refit 261 for slowly discharging pressure, and also communicates with an oil drain port 268 for quickly discharging pressure when the spool 261 is set upward in the figure.The spool 26
1 is set upward in the figure when the line pressure applied to the upper 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 oil chamber 265 is lower than the spring load of the spring 262. This is the time when the engagement pressure of the plate brake B4 is introduced.

When the manual shifter on the driver's seat is operated to set the H2, H4, or L4 range, the electronic control device (described later) activates the 1.2 solenoid valve 210.22 as shown in Table 2.
0 is ON and OFF controlled, and each frictional engagement element is operated by hydraulic oil selectively sent from the hydraulic control device 200 of the transfer 1 to each hydraulic servo B-4, C-3, and C-4, and the transfer 10 is each transmission type! (H2, H4, or L4). Further, when the first solenoid valve 210 is turned on by the hydraulic circuit configuration as described above, the transfer is set to H2 regardless of whether the second solenoid valve 220 is turned on or off.

The operation of solenoid valves 210 and 220 is as shown in Table 3. ON means energized, and OFF means not energized.

In general, A is a manual shift of the transfer 10, and B is a shift state from 1 to the transfer 110.

Table 3 describes the operation of the transfer manual shift in each setting range.

(A) Manual shift is in H2 range or H4 range,
When the transformer 7 is in H2 (two-wheel drive direct connection state), the first solenoid valve 210 → ON and the second solenoid valve 220 → OFF, so the line pressure is transferred from the oil path 104 to the orifice 34.
0 to the oil passage 205, but is drained by the energized first solenoid valve 210, and is drained from the upper end oil chamber 236.
Therefore, in the switching valve 230, the spool 231 is set upward in the drawing by the spring 232, and the 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 2 spool 242
Then, the first spool 241 is set to the lower blade shown in the figure. 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-4
and B-4 oil pressure are oil drain ports 238 and 25, respectively.
Drained from 5. Therefore, the transfer 10 becomes H2 (two-wheel drive direct connection type l1l).

(B) Manual shift is in H4 range, transfer is in H4 range
(4-wheel drive direct connection type 1), the first solenoid valve 210
→OFF Since the second solenoid valve 220 →OFF, the line pressure is transferred from the oil passage 104 to the orifice 34.
0 to the oil passage 205, but the first solenoid valve 2
10 is de-energized, the oil is output to the upper end oil chamber 236, and the spool 231 of the switching valve 230 is set to the lower side in the figure. Therefore, the line pressure is the oil passage 104, 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 passes from the oil passage 104 through the orifice 350 to the oil passage 20.
6, but since the second solenoid valve 220 is de-energized, the output is output to the upper end oil chamber 253 and the inhibitor valve 24
0 is the third, second, first spool 243.242.241
is set at the bottom in the figure. Therefore, line pressure is introduced into the clutch hydraulic servo C-3. In addition, the hydraulic servo [
The oil pressure of 3-4 is drained from the oil drain port 255. Therefore, the transfer 10 becomes H4 (four-wheel drive directly connected state).

(C) When the manual shift is in the L4 range, the vehicle speed is above the set value, and H4 (four-wheel drive direct connection state), the first solenoid valve 210 → OFF and the second solenoid valve 220 → ON, so the line pressure is Orifice 34 from oil passage 104
0 to the oil passage 205, but the first solenoid valve 2
10 is not energized, the upper end oil chamber 236 is inputted, and the switching valve 230 is set so that the spool 231 is positioned at the lower side in the figure. Therefore, the line pressure is the hydraulic servo C- of clutch C4.
4 will be introduced. On the other hand, the line pressure is also guided from the oil passage 104 through the orifice 350 to the oil passage 2 (16), 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. No line pressure is input to oil chamber 2.
51, the second and third spools 242 and 243 move upward in the figure, and since the governor pressure is above the set value, the first spool 241 overcomes the spring load of the spring 244. It is set at the bottom of the figure. Therefore, line pressure is introduced into hydraulic servo C-3 of clutch C3. Also, the oil pressure of hydraulic servo B-4 is at the oil drain port 25.
Drained from 5. Therefore, the transfer 10 becomes H4 (four-wheel drive directly connected state).

(D) When the manual shift is in the L4 range, the vehicle speed is below the set value, and the vehicle is in L4 (four-wheel drive deceleration state), the first solenoid valve 210 → OFF and the second solenoid valve 220 → ON, so the line pressure is Orifice 34 from oil passage 104
0 to the oil passage 205, but the first solenoid valve 2
10 is not energized, the upper end oil chamber 236 is input, and the switching valve 230 is set so that the spool 231 is in the downward direction as shown. Therefore, the line pressure is the hydraulic servo C- of clutch C4.
4 will be introduced. On the other hand, 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, 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 spool 242
．． 243 moves upward in the figure, and since the governor pressure is below the set value, it is defeated by the spring load of spring 244 and moves to the first position.
The spool 241 is set upward in the figure, and governor pressure is input to the lower end oil chamber 248 via the sleeve curve 254A. Therefore, the line pressure is
The hydraulic pressure of the multi-disc brake B4 is introduced into the brake cylinder B-4 via the oil passage 202 and the check valve 320.

In addition, the oil pressure of the hydraulic servo C-3 is directly connected to the oil passage 201,
Drain oil q266 via intermediate oil chamber 250, oil drain passage 207, and oil chamber 264 between downshift 1 and timing valve 260.
．． Drained from 268. Therefore, the transfer 10 becomes L4 (four-wheel drive deceleration state).

Also, the first spool 241 of the inhibitor valve 240 is connected to the oil chamber 2.
51 and the lower end oil chamber 248, the areas of the upper and lower end surfaces facing the oil chamber 251 and the lower end oil chamber 248 are the same, so 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 (I
Even if the I speed) increases, it does not move downward as shown in the figure, and the manual shift is set to the H2 range or H4 range and the oil chamber 252
Alternatively, unless line pressure is introduced into the upper end oil chamber 253, it remains set at the upper position in the figure due to the spring load of the spring 244. Therefore, the manual shift is set to range 14, and once the vehicle speed (governor pressure) falls below the predetermined value, L4 is set.
When this happens, L4 is maintained even if the vehicle speed (governor pressure) increases.

Electronic control device @50 that opens and closes the first solenoid valve 210 and the second solenoid valve 220 according to vehicle running conditions.
As shown in FIG. 5, the first embodiment of No. 0 includes an output shaft rotation speed sensor 501 that detects the rotation speed of the first output shaft 42 of the transfer 40, a throttle opening sensor 502 that detects the throttle opening of the engine E, and a transfer An input boat 511 that inputs the output from the transfer shift 1 to lever position sensor 504 that detects the set position of the shift lever 40, an output boat 512 that outputs to the first solenoid valve 210 and the second solenoid valve 220, and the center Arithmetic processing unit flcPU (hereinafter referred to as CPU), switching diagram corresponding to preset medium speed and throttle opening (Figure 6)
Read-only memory ROM (hereinafter referred to as ROM) and random access memory RAM (hereinafter referred to as RAM)
).

A first embodiment of the electronic control device @500 of this embodiment will be described based on the flowchart shown in FIG.

Turn the starter key ONL to operate engine E (60
1), the rotational speed signal of the first output horn shaft 42 of the transfer 40 from the output shaft rotational speed sensor 501, the throttle opening signal from the throttle opening sensor 502, the transfer shift lever position [1] To input the lever position signal 602), to judge whether the shift lever of the T-ranch 740 is set to the H2 range 603), when in the H2 range, the first solenoid valve 210 → ON, the second solenoid valve 220 → OFF The gears of the transfer 40 are H2 and 4 (6
04), and then returns to (602). When it is not in the H2 range, it is difficult to judge whether the shift lever of the transfer 40 is set to the H4 range (605), and when it is not in the H4 range, the first solenoid valve 210 → OFF and the second solenoid valve 220 → ON, and the transfer 40 The gear stage is 1. ．． 4 (
606), and then returns to (602). When in the H4 range, the rotational speed signal of the first output shaft 42 of the transfer 40 is converted into a vehicle speed (607), and then, when the vehicle speed and throttle opening are below the set values, the clutch C4 is released, that is, the gear position of the transfer 40 is changed. A switching diagram (Fig. 6) having a switching area where H2 is set to H2 is read from the ROM (6
08), determine whether it is in the switching area or not 609)
, when in the switching region, proceed to (604), and when not in the switching region, the first solenoid valve 210 → OFF and the second solenoid valve 220 → OFF, and the gear stage of the transfer 40 becomes 84 (13
10), and then returns to (602).

Next, a second embodiment of the electronic control device 500 is shown in FIG.

In this embodiment, the electronic control unit @ 500 includes the output shaft rotational speed sensor 501, which is the first means for detecting the vehicle speed;
The throttle opening sensor 502 is a second sensor that detects vehicle speed.
an actual vehicle speedometer 503, which is a means of
M, consists of RAM.

A second embodiment of the electronic control device 500 of this embodiment will be described based on the operation flowchart shown in FIG.

Turn the starter key ONL to start engine E (7
01), rotational speed signal of the first output shaft 42 of the transfer 40 from the output shaft rotational speed sensor 501 (N>, throttle opening signal from the throttle opening sensor 502,
The actual vehicle speed (Vl) from the actual vehicle speedometer 503, the transfer shift lever position signal from the transfer shift lever position sensor 504 are input (702), and the transfer? 4
0 shift lever is set to H2 range (703), when in H2 range, first solenoid valve 210 → ON, second solenoid valve 220 → OFF, and the gear position of transfer 40 becomes H2 (703).
4), and then returns to (702). When it is not in the H2 range, it is difficult to judge whether the shift lever of the transfer 40 is set to the H4 range.705>, when it is not in the H4 range, the first solenoid valve 210 → OFF, the second solenoid valve 220 → ON, and the transfer 40 The gear position is L4 (70
6), and then returns to (702). When in the H4 range, the rotational speed signal of the first output shaft 42 of the transfer 40 (
Convert N) to vehicle speed (■2) 707), 1 vehicle speed (■
2) - Actual vehicle speed (Vl) 1 < Set value (X) 708), l (V2) - (Vl) 1 x
Proceed to the time when it is not (711). 1V21(Vl)l<(
A switching diagram (
6) is read from the ROM (709), and it is determined whether or not it is in the switching area (710), and when it is in the switching area, (7
04), and when it is not in the switching region, the first solenoid valve 210 → OFF and the second solenoid valve 220 → OFF, and the gear stage of the transfer 40 becomes t14 (7
11), and then returns to (702).

[Brief explanation of the drawing]

FIG. 1 is a skeletal diagram of a known automatic transmission and a transfer related to the control v4 position of the vehicle four-wheel drive transmission of the present invention,
Fig. 2 is a sectional view thereof, Fig. 3 is a schematic diagram showing the power transmission system of the vehicle, and the fourth factor is the four-wheel drive of the present invention when applied to an automatic transmission with three forward speeds and one reverse speed. FIG. 5 is a circuit diagram of a four-wheel drive transfer hydraulic control device related to a transmission control device, and shows a first embodiment of an electronic control device related to control 8N of a vehicle four-wheel drive transmission of the present invention. Block Diagram,
Fig. 6 shows the control '4A of the vehicle four-wheel drive transmission of the present invention.
FIG. 7 is an operation flowchart of the first embodiment of the electronic control device of the control device for the vehicle four-wheel drive transmission of the present invention, and FIG. FIG. 9 is a block diagram of a second embodiment of an electronic control device for a control device for a wheel drive transmission. It is an operation flowchart of the second embodiment. In the figure 84...Multi-disc brake which is a frictional engagement element for deceleration C3...Multi-disc clutch which is a frictional engagement element for direct coupling C4...Multi-disc clutch which is a frictional engagement element for four-wheel drive B -4, C-3, C-4... Hydraulic servo 104
...Line pressure oil path 105...Manual valve 111
...Gover thick pressure oil passage 200...Hydraulic control of four-wheel drive transfer '@ position 201...First oil passage 202
...Second oil passage 203...Third oil passage 204...
4th oil path 210... 1st solenoid valve 220...
・Second solenoid valve 230...Switching valve 240...
・Inhibitor valve 241...first spool 242・
...Second spool 243...Third spool 252
・・・The oil chamber which is the designated oil chamber of the inhibitor valve

Claims (1)

[Claims] 1) For a vehicle equipped with a transmission, a two-wheel drive/four-wheel drive switching mechanism capable of switching between a two-wheel drive state and a four-wheel drive state, and a control device that controls the switching mechanism. A control device for a four-wheel drive transmission, wherein the control device includes means for detecting vehicle speed and means for detecting a throttle opening of an engine, and a switching diagram corresponding to a preset vehicle speed and throttle opening. A control device for a four-wheel drive transmission for a vehicle, characterized in that the switching mechanism is switched from a four-wheel drive state to a two-wheel drive state based on the following. 2) A four-wheel drive transmission for a vehicle, comprising a transmission, a two-wheel drive four-wheel drive switching mechanism capable of switching between a two-wheel drive state and a four-wheel drive state, and a control device that controls the switching mechanism. In the control device, the control device includes a first means for detecting vehicle speed, a second means for detecting vehicle speed, a means for detecting a throttle opening of an engine, and a first means for detecting vehicle speed and a second means for detecting vehicle speed. means for comparing the vehicle speed signals from the second vehicle speed detection means, and when the comparison result satisfies a preset condition, said switching is performed based on a switching diagram corresponding to a preset vehicle speed and throttle opening. A control device for a four-wheel drive transmission for a vehicle, characterized in that the mechanism is switched from a four-wheel drive state to a two-wheel drive state. 3) The four-wheel drive transmission for a vehicle according to claim 1, wherein the switching diagram includes a region in which a two-wheel drive state is set when the vehicle speed and throttle opening are below a set value. Control device. 4) The four-wheel drive transmission for a vehicle according to claim 2, wherein the switching diagram includes a region in which a two-wheel drive state is set when the vehicle speed and throttle opening are below a set value. Control device.