JPH0520622B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a vehicular automatic transmission equipped with an auxiliary transmission capable of switching between a high speed gear and a low speed gear. [Prior Art] Conventionally, vehicles capable of running in four-wheel drive mode often run on road conditions such as steep slopes, and high running ability is required, so they are installed in such vehicles. As an automatic transmission for vehicles, in addition to a main transmission with multiple gears, it is equipped with a sub-transmission that can switch between high and low gears, and by switching the sub-transmission to the low gear side, large drive Something that can give you power is proposed. The main transmission is switched according to vehicle driving conditions such as vehicle speed and throttle opening, and the auxiliary transmission is switched by operating a shift lever installed in the driver's seat, which produces a large driving force. When necessary, the driver operates a shift lever or the like to shift the sub-transmission to a lower speed side. [Problems to be Solved by the Invention] However, in conventional automatic transmissions for vehicles, the main transmission is switched depending on the vehicle running conditions such as vehicle speed and throttle opening, so the driver cannot switch the main transmission. It is necessary to switch the auxiliary transmission while taking into consideration the gear position of the auxiliary transmission, which is extremely difficult to judge, and requires skilled operation in order to obtain the appropriate driving force. In order to solve this problem, it is possible to automatically shift the auxiliary transmission according to the driving conditions of the vehicle. The problem is that more driving force than necessary is generated, resulting in poor gear shifting and poor fuel efficiency. Therefore, the present invention provides an automatic transmission for a vehicle having a main transmission having a plurality of gears and a sub-transmission capable of switching between a low gear and a high gear. If required,
The sub-transmission automatically shifts gears according to the vehicle driving conditions, and also prevents the sub-transmission from automatically shifting to lower gears during normal driving, such as on flat ground, to prevent the generation of more driving force than necessary. The purpose is to prevent deterioration in gear shifting shock and fuel efficiency. [Means for Solving the Problems] The vehicle transmission of the present invention includes a main transmission 10 having a plurality of gears, and a main transmission 10 that is drivingly connected to the main transmission and capable of switching between a high gear and a low gear. A sub-transmission 40,
In an automatic transmission for a vehicle comprising an electronic control device 600 that controls the gear shifts of each of the main transmission and the sub-transmission, automatic gear shifting is performed between a plurality of gear stages of the main transmission. a forward range D in which the main transmission can shift, and a low speed range 2, L in which the gears are mainly shifted to the lower gear side among the plurality of gears of the main transmission.
The electronic control unit 600 includes a shift switch 503 that detects the selected range of the shift lever, and a shift lever that is operated to select the forward and low speed ranges by the driver, and a shift switch 503 that detects the vehicle speed. A vehicle speed sensor 501 , a throttle opening sensor 502 that detects the throttle opening, and a low gear of the auxiliary transmission 40 within a shift range of the lowest gear of the main transmission 10 determined by the vehicle speed and the throttle opening. setting means 706, 706' for setting a shift line between the high speed gear and the first determining means 705, 711 for determining whether or not the low speed range 2, L is selected based on the signal from the shift switch 503; , the signals from the vehicle speed sensor 501 and the throttle opening sensor 502 are compared with the shift line set by the setting means 706, 706', and it is determined whether or not the sub-transmission 40 is in a low gear shift range. a second determining means 707 to
When the first determining means 705, 711 determines that the low speed range 2, L is not selected, the first determining means 705, 711 shifts the sub-transmission 40 to a high speed gear.
The speed change executing means 709, 710 and the first determining means 705, 711 determine that the low speed range 2, L is selected, and the second determining means 707 determines that the low speed range of the auxiliary transmission 40 is selected. The second shift execution means 704 shifts the auxiliary transmission 40 to a lower gear when it is determined that the gear is in the lower gear shift range. [Operations and Effects of the Invention] With the above configuration, in the automatic transmission for a vehicle of the present invention, the first determining means determines whether or not the driver has selected the low speed range with the shift lever, that is,
The driver determines whether or not the driver has selected a shift mainly in the low gear range of the main transmission because driving force is required, and when it is determined that the driver has not selected the low speed range, the second shift execution means Since the auxiliary transmission is shifted to a high speed gear, it does not generate more driving force than necessary, and it is possible to prevent gear shift shock and deterioration of fuel efficiency during normal driving on flat ground. If it is determined that the low speed range is selected, the second determining means compares the signals from the vehicle speed sensor and the throttle opening sensor with the shift line of the sub-transmission set by the setting means. If it is determined that the gear is in the low gear shift range, the second
The auxiliary transmission is automatically shifted to a low gear by the shift execution means, and a large driving force is obtained, thereby improving the ability to travel on steep slopes, etc. In addition, at this time, since the shift line of the sub-transmission set by the setting means is set within the shift range of the lowest gear of the main transmission, the sub-transmission will be activated only when the throttle opening is high and the vehicle speed is low. If the driver does not press the accelerator pedal significantly at low vehicle speeds, the auxiliary transmission will maintain the high gear and normal driving force will be obtained from the main transmission alone. When the accelerator pedal is fully depressed, the auxiliary transmission is shifted to a low gear and a large driving force is obtained, so that the driving force that meets the demand can be obtained. [Example] Next, the present invention will be explained based on an example shown in the drawings. Figure 1 shows a multi-stage four-wheel drive automatic transmission with three forward speeds and one reverse speed, and Figure 2 shows its gear train. Reference numeral 10 indicates a 3-speed forward automatic transmission with 1 reverse speed, which is a main transmission, and 40 indicates a 4-wheel drive transfer, which is an auxiliary transmission, which is 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 D. The torque converter T includes 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, 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
It serves as the input shaft 12 of the planetary gear transmission mechanism D. The planetary gear transmission mechanism D includes multi-plate clutches C1 and C2, which are frictional engagement elements, and a multi-plate flake B.
1, B2 and B3, one-way clutches F1 and F2, a front planetary gear set P1, and a rear planetary gear set P2. The rear planetary gear set P2 is the clutch C.
A ring gear 31 is connected to the input shaft 12 through a clutch C2, a carrier 33 is connected to an output shaft 32 of a planetary gear transmission mechanism D, and a brake is connected to the input shaft 12 through a clutch C2. B
1. A brake B2 parallel to the brake B1,
A sun gear 34 is fixed to the transmission case via a one-way clutch F1 directly connected to B3 and a brake B2, and a sun gear 34 and a ring gear 31 are rotatably supported by the carrier 33.
It consists of a planetary pinion 35 meshed with. The front planetary gear set P1 is the brake B
3, 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 P2.
and a ring gear 38 connected to the output shaft 32,
It consists of a planetary pinion 39 rotatably supported by a carrier 36 and meshed with a sun gear 37 and a ring gear 38. This four-wheel drive automatic transmission uses a hydraulic control device 100 of the automatic transmission 10 shown in FIG. Selective engagement or disengagement is performed, resulting in three automatic forward gear shifts and one reverse gear shift using only manual gear shifting. A shift lever (not shown) provided at the driver's seat for driving the manual valve of the hydraulic control device 100
has shift positions SP in each range: P (parking), R (reverse), N (neutral), forward range D (drive), low speed range 2 (second) and L (low). , this shift position SP and gears, 3rd gear (3), 2nd gear (2),
Table 1 shows the operational relationship between the first speed (1) and the clutch and brake. In Table 1, ◯ 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] Reference numeral 100 in the figure is an example of a known hydraulic control device for an automatic transmission with three forward speeds and one reverse speed. The pressure is regulated to oil pressure (line pressure) and guided to the oil passage 104. The pressure oil led to the oil passage 104 passes through the manual valve 105 to 1-2.
It is guided to 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. The manual valve 105 is connected to a shift lever provided on the driver's seat, and is manually operated to switch between P (parking) and R depending on the range of the shift lever.
(Reverse), N (Neutral), D (Drive),
Move to the 2 (second) and L (low) positions. As shown in FIG. 2, the transfer shaft 40 in FIG. a cabana valve 110 fixed to the input shaft 32;
An output shaft 42, a planetary gear set Pf disposed between the input shaft 32 and the first output shaft 42, a four-wheel drive sleeve 51 rotatably fitted around the first output shaft 42, and the input shaft. 32, a second output shaft 52 is installed in the opposite direction to the first output shaft 42, and a transmission device 53 is provided between the sleeve 51 and the second output shaft 52. The planetary gear set Pf includes a sun gear 44 spline-fitted to the end of the input shaft 32, a planetary pinion 45 that meshes with the sun gear 44, a ring gear 46 that meshes with the planetary pinion 45, and rotates the planetary pinion 45. It consists of a carrier 47 which is freely held and connected to the tip of the first output shaft 42 of the transfer shaft 40. In this embodiment, the brake B4 is a multi-plate friction brake for engaging the ring gear 46 with the truss case 48, and includes a cylinder 49 formed in the transfer case 48 and a piston 49P mounted in the cylinder 49. It is operated by a hydraulic servo B-4 consisting of. The clutch C3 is arranged on the automatic transmission 10 side of the planetary gear set Pf, and connects and disconnects the sun gear 44 and the carrier 47, and connects the cylinder 50 connected to the carrier 47 and the piston 50P installed in the cylinder 50. It is operated by a hydraulic servo C-3 consisting of.
The clutch C4 is a multi-plate type clutch for connecting and disconnecting the first output shaft 42 connected to the carrier 47 and the sleeve 51 connected to one sprocket 56 of the transmission device 53 for driving the second output shaft 52 of the transfer 40. It is a friction clutch and is operated by a hydraulic servo C-4, which is comprised of a cylinder 58 rotatably supported by the transfer case 48 and a piston 58P mounted within the cylinder 58.
The transmission device 53 includes a sprocket 56 formed with the sleeve 51, a sprocket 55 spline-fitted to the second output shaft 52, and a chain 57 stretched between these sprockets. A parking gear 59 is provided around the outer circumferential side of the cylinder 50 of the hydraulic servo C-3, and when the shift lever of the automatic transmission 10 is selected to the parking position, the pawl engages with a parking pawl (not shown) and the parking gear 59 engages with the parking pawl (not shown). 1. The output shaft 42 is fixed. 60 is a hydraulic servo C- for clutches C3 and C4 of the four-wheel drive transfer 40 and brake B4.
A transfer valve body is provided with a transfer control device 200 for supplying and discharging hydraulic pressure to 3, C-4 and B-4, and 61 is its oil pan. Pressure oil supplied to the hydraulic servos C-3, C-4 and B-4 of the clutches C3 and C4 and the brake B4 is connected between the transmission case 62 and the transfer case by an oil pan 62A fastened to the transmission case 62. It is led through a pipe 64 attached to the case 48 to a transfer valve body 60 in which a transfer control device 200 is provided. This transfer is attached to an automatic transmission D attached to a vehicle engine E as shown in FIG. A certain second output shaft 52 is used while being connected to the front wheel drive propeller shaft B. During normal driving, the line pressure supplied to the hydraulic control device 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 engage brake B4 and clutch. Release C4. As a result, the sun gear 44 and carrier 47 of the planetary gear set Pf are connected, and power is transmitted from the input shaft 32 to the first output shaft 42.
The transmission is transmitted at a reduction ratio of 1 to achieve two-wheel drive driving using only the rear wheels. At this time, the power from the input shaft 32 is transmitted from the carrier 47 to the first output shaft 42 via the clutch C3 without passing through the sun gear 44, planetary gear pinion 45, or ring gear 46.
No load is applied to the tooth surface of each gear, increasing the life of the gear. If 4-wheel drive is required during this 2-wheel drive driving, manually shift the shift lever (not shown) provided on the driver's seat to gradually apply line pressure to the transfer control device 200 hydraulic servo C-4. When the clutch C4 is smoothly engaged, the first output shaft 42 and the sleeve 51 are connected, and the transmission device 53, the second output shaft 52 and the propeller shaft B are connected.
(shown in Fig. 1), the power is also transmitted to the front wheels, and the power is transmitted from the input shaft 32 to the first output shaft 42 and the second output shaft 52 at a reduction ratio of 1. wheel drive condition). During this four-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 to the inhibitor valve 240, which is a switching valve between a high-speed four-wheel drive state and a low-speed four-wheel drive state. Activate the shift timing valve 260 to gradually supply line pressure to the hydraulic servo B-4, supply and discharge hydraulic pressure from the hydraulic servo C-3 at appropriate timing, gradually engage the brake B4, and smoothly operate the clutch C3. to be released. As a result, sun gear 44 and carrier 47 are released, ring gear 46 is fixed, and power is transferred to input shaft 32.
is decelerated and transmitted to the first output shaft 42 and second output shaft 52 via the sun gear 44, planetary pinion 45, and carrier 47.
A wheel drive deceleration traveling state (low speed four-wheel drive state) is obtained. Table 2 shows the running conditions and the engagement and release states of brake B-4 and clutches C3 and C4.

[Table] In Table 2, ○ indicates the engaged state of the friction engagement element, and × indicates the released state. The reduction ratio (3.0 in the example) is
The ratio of the number of teeth between the sun gear 44 and the ring gear 46 of the planetary gear mechanism is λ, and the reduction ratio is calculated as follows: (1+λ)/λ=3.0, where λ is 0.5. The four-wheel drive transfer control device 200 includes a first solenoid valve 210 and a second solenoid valve 22.
0, the switching valve 230, the inhibitor valve 240, and the downshift timing valve 26 provided in the oil drain passage 207 for the engagement pressure for direct connection via the inhibitor valve 240.
0. Direct coupling friction engagement element, that is, multi-plate clutch C
The first oil passage 20 that connects to the hydraulic surfactant C-3 of No. 3
1. Frictional engagement element for deceleration, that is, multi-disc brake B
4 hydraulic servo B-4.
2. Third oil passage 2 connected to hydraulic servo C-4 of four-wheel drive frictional engagement element, ie, multi-disc clutch C4.
03, a fourth oil passage 204 connecting a predetermined oil chamber of the switching valve 230 and the inhibitor valve 240;
Check valve 31 provided in each of the 2nd and 3rd oil passages
0, 320, 330, a line hydraulic path 104 and a first solenoid pressure oil path 205 and a second solenoid pressure oil path 20 via orifices 340, 350.
Consists of 6. 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
The oil pressure in the oil passages 205 and 206 separated from the 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 valve 240 has three spools 241, 24 in the order of first, second, and third from the bottom in the figure.
2,243, and the first spool 241 has a sleeve-shaped land 2 with a spring 244 on its lower end.
45 and two lands 246, 247, a lower end oil chamber 248, a sleeve-shaped land 245 and land 2.
Intermediate oil chambers 249, 25 between 46 and land 247
0, 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. The inhibitor valve 240 has a first
When the spool 241 is set upward in the figure,
The lower end oil chamber 248 has an oil port 254 in a sleeve-like land.
The intermediate oil chamber 249 communicates with the governor pressure oil passage 111 via A, and the intermediate oil chamber 249 communicates with the line pressure oil passage 104 and the second oil passage 202.
The intermediate oil chamber 250 connects the first oil passage 201 and the oil drain port 266, and when the first spool 241 is set downward in the figure, the lower end oil chamber 248 connects the oil port 254A of the sleeve-shaped land. Through the oil drain port 254
The intermediate oil chamber 249 communicates with the second oil passage 202 and the oil drain port 255, and the intermediate oil chamber 250 communicates with the line pressure oil passage 104 and the first oil passage 201. Further, 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 pressure 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 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 figure by the spring 232, and the line hydraulic path 104 and the fourth hydraulic path 204 are connected via the first intermediate oil chamber 234, and the inhibitor is connected. Line pressure is supplied to the oil chamber 252 of the valve, and the third oil passage 2 is supplied via the second intermediate hydraulic chamber 235.
03 and the oil drain port 238 are communicated, and the hydraulic servo C
-4 is depressurized. 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.
is formed. The downshift timing valve 260 has a lower end oil chamber 263 that is always connected to the deceleration oil passage 20.
2, the upper end oil chamber 265 is always in communication with the line pressure oil passage 104, and the intermediate oil chamber 264 is always in communication with the line pressure oil passage 2.
07 and an oil drain port 266 provided with an orifice 267 for slowly discharging pressure, and
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 the multi-disc brake B4 is introduced. When you operate the manual shift on the driver's seat and set the H2, H4, or L4 range, the first and second solenoid valves 210 and 220 are controlled ON and OFF as shown in Table 2 by the electronic control device described later, and the transfer From the control device 200 to each hydraulic servo B-
4, C-3, and C-4 are selectively sent to each frictional engagement element to actuate the transfer 4.
0 is shifted to each shift state (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 the solenoid valves 210 and 220 is as shown in Table 3. 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 and the transfer 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 passage 104 to the orifice 340. The oil is guided to the oil passage 205 through the energized first solenoid valve 210 and is not output to the upper 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 40 is H2 (two-wheel drive direct connection state)
become. (B) When the manual shift is in the H4 range and the transfer is in H4 (4-wheel drive direct connection state): The first solenoid valve 210 → OFF The second solenoid valve 220 → OFF, so the line pressure is transferred from the oil passage 104 to 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-3. Also, the oil pressure of hydraulic servo B-4 is at oil drain port 2.
Drained from 55. Therefore, the transfer gear 40 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 the vehicle is in H4 (4-wheel drive directly connected state).The first solenoid valve 210→OFF and the second solenoid valve 220→ON, so the line pressure is 104, is guided to the oil path 205 through the orifice 340, but since the first solenoid valve 210 is not energized, it is input to the upper end oil chamber 236, and the switching valve 230 is set so that the spool 231 is at the lower side in the figure. Therefore, the 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, 243 move upward in the figure, and since the governor pressure is above the set value, the spring 242
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. Also, the oil pressure of hydraulic servo B-4 is at the oil drain port 25.
Drained from 5. Therefore, the transfer gear 40 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 (4-wheel drive directly connected state).The first solenoid valve 210→OFF and the second solenoid valve 220→ON, so the line pressure is 104, is guided to the oil path 205 through the orifice 340, but since the first solenoid valve 210 is not energized, it is input to the upper end oil chamber 236, and the switching valve 230 is set so that the spool 231 is at the lower side in the figure. Therefore, the 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, 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 2
42 and 243 move 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 lower end oil chamber is moved through the oil port 254A of the sleeve. Governor pressure is input to 248. Therefore, the line pressure is introduced to the hydraulic servo B-4 of the multi-disc brake B4 via the oil passage 104, the oil chamber 249, the second oil passage 202 and the check valve 320. In addition, the oil pressure of the hydraulic servo C-3 is applied to the direct connection oil passage 201, the second intermediate oil chamber 250, and the drainage oil passage 201.
7. The oil is drained from the oil drain ports 266 and 268 via the oil chamber 264 located in the middle of the downshift timing valve 260. Therefore, transfer 40
becomes L4 (four-wheel drive deceleration state). Also, the first spool 24 of the inhibitor valve 240
1 has the same area of the upper and lower end surfaces facing the oil chamber 251 and the lower end oil chamber 248, 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 Even if the pressure (vehicle speed) increases, it does not move downward in the figure, 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, the spring load of the spring 244 It remains set at the top in the figure. Therefore, the manual shift is set to L4 range, and once the vehicle speed (governor pressure) falls below a predetermined value and reaches L4, even if the vehicle speed (governor pressure) increases, it will shift to L4.
is maintained. When the manual shift is in the H2 or H4 range, the vehicle speed is low, and the throttle opening is large (when a large driving force is required), the first solenoid valve 210 → OFF and the second solenoid valve 220 → ON, so the line pressure is 104 through the orifice 340, but since the first solenoid valve 210 is not energized, the input is input to the upper end oil chamber 236, and the switching valve 230 is guided to the spool 23.
1 is set at the bottom in the figure. Line pressure is therefore introduced into hydraulic servo C-4 of clutch C4. On the other hand, the line pressure is from the oil passage 104 to the orifice 3.
50 and is also guided to the oil passage 206, but is drained by the energized solenoid valve 220.
No input is made to the upper end oil chamber 253 of the inhibitor valve 240. Also, line pressure is not input to the oil chamber 252.
Here, since the governor pressure is input to the oil chamber 251, the second and third spools 242, 243 move upward in the figure, and since the governor pressure is below the set value, the spring load of the spring 244 is applied to the first spool. The spool 241 is set upward in the figure, and governor pressure is input to the lower end oil chamber 248 through the oil port 254A of the sleeve. Therefore, the line pressure is
is introduced into the hydraulic servo B-4 of the multi-disc brake B4. In addition, the oil pressure of the hydraulic servo C-3 is applied to the direct connection oil passage 201, the second intermediate oil chamber 250, and the drainage oil passage 201.
7. The oil is drained from the oil drain ports 266 and 268 via the oil chamber 264 located in the middle of the downshift timing valve 260. Therefore, transfer 40 is L4
(4-wheel drive deceleration state). The electronic control device will be explained based on the block diagram shown in FIG. The electronic control device 600 controls a vehicle speed sensor 501 that detects the vehicle speed, a throttle opening sensor 502 that detects the throttle opening, and a shift position of a shift lever that sets the transmission means to detect the torque ratio of the automatic transmission 10. Shift switch 503 to detect, shift switch 50 of transfer 40
an input port 611 for inputting the output signal from 4;
A shift diagram of the four-wheel drive transmission preset in the output port 612 that outputs to the solenoid valves 210 and 220, the central processing unit CPU, and the memory circuit (the case where the automatic transmission 10 is set in the 2nd range is shown below). 6 shows a case where the setting range of the automatic transmission 10 is L range is shown in FIG. 7), a read-on memory ROM, and a random access memory RAM.
Consisting of The shift diagram in the case of two ranges shown in FIG. 6 is set on the lower vehicle speed side than the shift line for shifting between the first and second speeds of the main transmission. Also, L shown in Figure 7
The shift diagram for range is set on the higher vehicle speed side than the shift diagram for two ranges. Here, the shift diagrams shown in Figures 6 and 7 are H2, H
4←→L4 is provided with hysteresis to prevent frequent gear changes. FIG. 8 shows an operational flowchart of the electronic control unit 600. Turn on the starter key to start the engine E (701), then receive a vehicle speed signal from the vehicle speed sensor 501, a throttle opening signal from the throttle opening sensor 502, and a shift switch 50 of the automatic transmission 10.
3 inputs the automatic transmission shift range signal and the transfer shift range signal from the shift switch 504 of the transfer 40, determines whether the manual shift of the transfer 40 is set to the L4 range 703, and inputs the transfer shift range signal from the shift switch 504 of the transfer 40. At this time, the first solenoid valve 210 → OFF and the second solenoid valve 220 → ON, and the transfer gear 40 is shifted to L4 and 70
4. Then return to 702. When it is not in the L4 range, it is determined whether the shift lever of the automatic transmission 10 is set in the 2nd range (705), and when it is in the 2nd range, the 2nd range shift diagram shown in FIG. 6 is read from the ROM, and the sub-shift is performed. The gear shift diagram of the machine is set (setting means 706), and it is determined whether or not it is in the H4→L4 shift range. When the vehicle speed is high and the throttle opening is small (when a small driving force is sufficient), the process proceeds to the second shift execution means 704, when the vehicle speed is high and the throttle opening is small (when a small driving force is sufficient). It is determined that the manual shift of the transfer shaft 40 is set to the H4 range (708), and when the manual shift of the transfer gear 40 is set to the H4 range, the first solenoid valve is turned off in the first shift execution means 709, and the second solenoid is turned OFF. The valve is turned OFF, the transfer 40 is shifted to the H4 range, and then returns to the H4 range. When it is not in the H4 range, the first solenoid valve 210 is turned ON and the second solenoid valve 220 is turned OFF in the first shift execution means 710, and the transfer gear 40 is shifted to H2.
4. Then return to 702. First judgment means 7
At 05, the shift lever of the automatic transmission 10 is set to 2.
When the range is not set, the first judgment means 7
11, the shift lever of the automatic transmission 10 is in the L position.
It is determined whether or not it is set in the range, and if it is not in the L range, the process goes to 708, and if it is in the L range, the L range shift diagram (Fig. 7) is read from the ROM in the setting means 706', and then the second Judgment means 7
Proceed to 07. Thereafter, processing is performed in the same manner as in the case of two ranges described above. FIG. 9 shows a V-belt type continuously variable transmission used as a main transmission of an automatic transmission for a vehicle according to the present invention. 800 is the engine, 802 is the carburetor, 82
0 is a transmission device provided between the engine 800 and the drive side axle, and the output shaft 801 of the engine
a fluid coupling 821 connected to a differential gear 822, a reduction gear mechanism 823 connected to a differential gear 822, and a V-belt continuously variable transmission 830.
and a planetary gear transmission 840 for new switching after forward movement. Fluid coupling 821 is well known and consists of a pump impeller 821A and a turbine runner 821B connected to an output shaft 821D. Note that a fluid torque converter or a mechanical clutch may be used instead of the fluid coupling. The V-belt type continuously variable transmission 830 includes a fixed flange 831A connected to a fluid coupling output shaft 821D, which is an input shaft of the continuously variable transmission 830;
A movable flange 831 provided to face the fixed flange 831A and form a V-shaped space.
B, and an input pulley 831 consisting of a hydraulic servo 831C that drives the movable flange 831B.
and an intermediate shaft 82 which is the output shaft of the continuously variable transmission 830.
6, a movable flange 832B provided to face the fixed flange 832A to form a V-shaped space, and a hydraulic servo 8 that drives the movable flange 832B.
This is a well-known device consisting of an output pulley 832 made of 32C, and a V-belt 833 connecting these input pulley 831 and output pulley 832. The planetary gear transmission 840 for forward/reverse switching is
Sun gear 841 connected to intermediate shaft 826, which is the output shaft of continuously variable transmission 830, and transmission case 9
00 through a multi-disc brake 842, a ring gear 843, a sun gear 841 and a ring gear 8.
43, a double planetary gear 844 rotatably meshed with the double planetary gear 844;
The multi-disc clutch 84 rotatably supports the
A second intermediate shaft 847 is connected to the intermediate shaft 826 via a second intermediate shaft 847 and is an output shaft of the planetary gear transmission 840.
A hydraulic servo 848 that operates a multi-disc brake 842 and a hydraulic servo 849 that operates a multi-disc clutch 845 are connected to the planetary carrier 846 . This planetary gear transmission 840 for forward/reverse switching provides a forward gear with a reduction ratio of 1 when the multi-disc clutch 845 is engaged and the multi-disc brake 842 is released;
5 is released and the multi-plate brake 842 is engaged, it becomes a reverse gear with a reduction ratio of 1.02. This reduction ratio of 1.02 in reverse is small compared to the reduction ratio in reverse of the image transmission for automobiles, but in this example, the reduction ratio obtained in the V-belt continuously variable transmission (for example, 2.4 ), and the reduction gear mechanism 823 described later performs the reduction, so that an appropriate reduction ratio can be obtained as a whole. The reduction gear mechanism 823 is intended to compensate for the fact that the speed change range obtained by the V-belt continuously variable transmission 830 is lower than the speed change range achieved by a normal vehicle transmission, and the reduction gear mechanism 823 changes the reduction ratio between the input and output shafts. A 1.45 speed change is performed to increase torque. 902 is a rotation speed sensor that detects the rotation speed of the input pulley 831; 903 is a vehicle speed sensor; 90
A throttle opening sensor 4 detects the throttle opening of the carburetor 801. Furthermore, 950
is an auxiliary transmission, and includes a sun gear 951 connected to the third hollow output shaft 823A of the reduction gear mechanism 823;
Planetary pinion 9 meshed with sun gear 951
52, a ring gear 953 meshed with the planetary pinion 952, a carrier 954 that rotatably supports the planetary pinion 952, and a clutch 9;
55. A high speed/low speed switching mechanism 960 consisting of a brake 957 that fixes the ring gear 953 to the case 956, and a carrier 954 of the switching mechanism 960.
The first output shaft 958 and the clutch 95 are always connected to the
9 Second output shaft 9 connected to carrier 954 when engaged
61 and a two-wheel/four-wheel switching mechanism 970. Also in this embodiment, FIGS. 5, 6, 7,
It is similarly controlled by the control device shown in FIG. However, the shift switch 5 is a continuously variable transmission 830.
A shift lever (not shown) that sets the torque ratio of
Detect shift position. In the above embodiments, the torque ratio of the main transmission is detected from the shift position of the shift lever of the main transmission, but in addition, (a) the torque or rotational speed of the input shaft and output shaft of the main transmission is detected. (b) Detects the hydraulic pressure of the hydraulic servo that determines the gear position of the main transmission. (c) If the main transmission is controlled by an electronic control device, detect the shift signal of the control device. It can be similarly controlled by, etc.

[Brief explanation of the drawing]

Fig. 1 is a skeletal diagram of a known automatic transmission and a transfer related to the shift control device of an automatic transmission for a vehicle according to the present invention, Fig. 2 is a sectional view thereof, and Fig. 3 is a power transmission system of a vehicle. A schematic diagram, FIG. 4 is a circuit diagram of a hydraulic control device for a four-wheel drive transfer according to a shift control device for an automatic transmission for a vehicle according to the present invention when applied to an automatic transmission with three forward speeds and one reverse speed; FIG. 5 is a block diagram of a shift control device for an automatic transmission for a vehicle according to the present invention, FIG. 6 is a shift diagram for the shift control device for an automatic transmission for a vehicle according to the present invention, and FIG. 7 is a diagram for a vehicle according to the present invention. FIG. 8 is an operation flowchart of the electronic control device for the automatic transmission for vehicles of the present invention, and FIG. 9 is a shift diagram for the automatic transmission for vehicles of the present invention. FIG. 2 is a skeletal diagram of a V-belt continuously variable transmission used as a main transmission of a control device. In the diagram, 10... automatic transmission (main transmission), 40...
...4-wheel drive transfer (auxiliary transmission), 501
... Vehicle speed sensor, 502 ... Throttle opening sensor, 503 ... Shift switch, 600 ... Electronic control device, 704 ... Second shift execution means, 70
5,711...first determination means, 706,70
6'...Setting means, 707...Second judgment means,
709, 710...first shift execution means, D...
Forward range, 2, L...Low speed range.

Claims (1)

[Scope of Claims] 1. A main transmission having a plurality of gears, a sub-transmission that is drivingly connected to the main transmission and capable of switching between a high speed gear and a low gear, and the main transmission and the sub-transmission. An automatic transmission for a vehicle comprising: an electronic control device that controls the shifting of each gear of the main transmission; The electronic control device includes a shift lever that is operated to select between the forward speed range and the low speed range by the driver, and the electronic control device has a low speed range that mainly changes the low speed side among the plurality of speeds of the machine, and the shift lever is selectively operated by the driver between the forward speed range and the low speed range. a shift switch that detects the selected range of the main transmission; a vehicle speed sensor that detects the vehicle speed; a throttle opening sensor that detects the throttle opening; and a lowest gear position of the main transmission determined by the vehicle speed and the throttle opening. a setting means for setting a shift line between a low gear and a high gear of the auxiliary transmission within a gear shifting range; and a first determining unit for determining whether or not the low gear range is selected based on a signal from the shift switch. a second determining unit that compares the signals from the vehicle speed sensor and the throttle opening sensor with the shift line set by the setting unit to determine whether or not the sub-transmission is in a low gear shift range. determination means; first shift execution means for shifting the auxiliary transmission to a high gear when the first determination means determines that the low speed range is not selected; and the first determination means a second step for shifting the sub-transmission to a low speed when it is determined that the low-speed range is selected and the second determining means determines that the sub-transmission is in a low-speed gear shift range;
An automatic transmission for a vehicle, characterized in that it has a speed change execution means. 2. The low speed range of the shift lever consists of the 2nd range and the L range, and the L range is the 2nd range.
Shifting is performed mainly on the lowest gear side of the main transmission further than the range, and the setting means sets shift lines corresponding to the two ranges and the L range, respectively, and the set shift lines are 2. The control device for a vehicle transmission according to claim 1, wherein the L range is set at a higher vehicle speed than the 2nd range.