JPS6147352B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a control device for an electronically controlled automatic transmission used in automobiles and the like. [Prior Art] [Problems to be Solved by the Invention] A control device for an electronically controlled automatic transmission is provided with a solenoid valve in an oil path of a hydraulic circuit, and operates the solenoid valve to open and close according to the output of an electric circuit. Controlling the transmission mechanism by discharging or maintaining the hydraulic pressure in the oil passage, switching and controlling the shift valve using the hydraulic pressure in the oil passage, and supplying and discharging the hydraulic pressure generated by the oil pump to a predetermined hydraulic servo. is being carried out. [Problems to be Solved by the Invention] Since the oil pump of such an automatic transmission is driven by the engine, the amount of oil discharged is proportional to the rotational speed of the engine. Therefore, if the amount of oil discharged from the solenoid valve is large when the vehicle is stopped and the engine rotation is low, a problem arises in that the amount of lubricating oil or hydraulic oil pressure is likely to be insufficient when the vehicle starts. To solve this problem, for example, it is possible to use a large oil pump with a large discharge volume, or to de-energize all the solenoid valves when the solenoid valves are operated to achieve the low gear set when the vehicle is stopped. It is conceivable to reduce the amount of oil discharged from the hydraulic circuit when the vehicle is stopped by configuring the hydraulic pressure in the oil passage to be maintained, but the former method uses the driving force from the engine required to drive the oil pump. Naturally, the disadvantage is that the transmission efficiency of the automatic transmission deteriorates due to the large size of the transmission, and the latter method requires that the transmission mechanism be shifted to a lower gear when a failure such as a disconnection occurs in the electric circuit that operates the solenoid valve. If such a failure occurs while driving at high speed, the gear will be immediately shifted from a high speed to a low speed, resulting in sudden engine braking or engine overrun, which is undesirable. The present invention has been made in view of the above problems, and it reduces the amount of oil discharged from the solenoid valve when the transmission mechanism is set to a low gear, thereby reducing the amount of lubricating oil or the lack of hydraulic oil pressure when starting the vehicle. An automatic transmission control device that can prevent sudden engine braking or engine overrun during high-speed driving by shifting the transmission mechanism to a high gear in the event of an electrical circuit failure. The purpose is to provide. [Means for Solving the Problems] The automatic transmission control device of the present invention has a plurality of hydraulic servos, and selectively supplies and discharges hydraulic pressure to the hydraulic servos to control at least low and middle gears. In a control device for an automatic transmission equipped with a transmission mechanism capable of achieving gears and high gears, a means for generating an electric signal according to a vehicle running state and an output signal corresponding to each gear by input from the means and a hydraulic circuit that selectively supplies and discharges hydraulic pressure to the hydraulic servo according to an output signal of the electric circuit, and the hydraulic circuit is a hydraulic power source driven by an engine. , first and second oil passages supplied with oil pressure from the oil pressure source; when energized by the output signal of the electric circuit, the oil pressure of the first oil passage is exhausted, and when not energized, the oil pressure of the first oil passage is discharged; a first solenoid valve disposed to maintain hydraulic pressure in the first oil passage; and a first solenoid valve disposed to maintain hydraulic pressure in the second oil passage when energized by the output signal of the electric circuit, and discharge the oil pressure in the second oil passage when not energized. a second solenoid valve disposed to maintain hydraulic pressure in the second oil passage; and a second solenoid valve that is switched to one position and discharged when the oil pressure in the first oil passage is maintained; The first, sometimes switched to the other position.
and a second shift valve that is switched to one position when the hydraulic pressure in the second oil passage is discharged and switched to the other position when the pressure is maintained, The transmission mechanism achieves a low gear when the first shift valve is in the one position and the second shift valve is in the one position, and the first shift valve is in the other position and the second shift valve is in the one position. When the second shift valve is in the one position, the transmission mechanism achieves the middle gear, and the second shift valve is in the first position.
Hydraulic pressure from the hydraulic source is supplied to and discharged from the hydraulic servo so that the transmission mechanism achieves a high speed gear when the shift valve is in the other position and the second shift valve is in the other position. The first shift valve is characterized in that when the second shift valve is in the other position, the first shift valve is switched to the other position regardless of the oil pressure in the first oil passage. [Operation and Effects of the Invention] According to the automatic transmission control device of the present invention, it is possible to reduce the discharge flow rate from the first solenoid valve in the low gear stage, thereby reducing the amount of lubricating oil when starting the vehicle. Alternatively, the second shift valve can be switched to the other position when the second solenoid valve is de-energized in the event of a failure of the electric circuit, while preventing a shortage of hydraulic fluid pressure from occurring. At the same time, the first shift valve can be switched to the other position regardless of the operation of the first solenoid valve, and the transmission mechanism can be shifted to a high gear. It is possible to prevent overruns from occurring. [Example] Next, the present invention will be explained based on an example shown in the drawings. FIG. 1 is a schematic diagram showing an example of a planetary gear unit of a hydraulic four-speed automatic transmission with an overdrive device. The planetary gear unit of this automatic transmission includes a torque converter 1, an overdrive mechanism 2, and a planetary gear transmission mechanism 3 with three forward speeds and one reverse speed, and is controlled by a hydraulic circuit device as shown in FIG. It's becoming like that. The torque converter 1 is a well-known type that includes a pump 5, a turbine 6, and a stator 7. The pump 5 is connected to an engine crankshaft 8, and the turbine 6 is connected to a turbine shaft 9. The turbine shaft 9 constitutes the output shaft of the torque converter 1, which also serves as the input shaft of the overdrive mechanism 2, and is connected to a carrier 10 of a planetary gear system in the overdrive mechanism. A planetary pinion 14 rotatably supported by a carrier 10 meshes with a sun gear 11 and a ring gear 15. sun gear 11
A multi-disc clutch 12 and a one-way clutch 13 are provided between the sun gear 11 and the carrier 10, and a multi-disc brake 19 is provided between the sun gear 11 and a housing or overdrive case 16 that encloses the overdrive mechanism. It is being The ring gear 15 of the overdrive mechanism 2 is the input shaft 23 of the planetary gear transmission mechanism 3 with three forward speeds and one reverse speed.
is connected to. A multi-disc clutch 24 is provided between the input shaft 23 and the intermediate shaft 29, and a multi-disc clutch 25 is provided between the input shaft 23 and the sun gear shaft 30. A multi-disc brake 2 is provided between the sun gear shaft 30 and the transmission case 18.
6. Multi-disc clutch 40 and one-way clutch 41
is provided. The sun gear 32 provided on the sun gear shaft 30 includes a carrier 33, a planetary pinion 34 supported by the carrier, a ring gear 35 meshing with the pinion, another carrier 36, and a planetary pinion 37 supported by the carrier. , a ring gear 3 that meshes with the pinion.
Together with 8, it constitutes a two-row planetary gear system. A ring gear 35 in one of the planetary gears is connected to an intermediate shaft 29. Further, the carrier 33 in this planetary gear device is connected to a ring gear 38 in the other planetary gear device, and these carrier and ring gear are connected to an output shaft 39.
Further, a multi-disc brake 27 and a one-way clutch 28 are provided between the carrier 36 and the transmission case 18 in the other planetary gear set. The planetary gear unit of such a hydraulic automatic transmission with an overdrive device engages or releases each clutch and brake according to the engine output and vehicle speed by a hydraulic circuit device, which will be explained in detail below. 4 forward speeds including drive (O/D) or reverse 1 with manual switching
It is designed to shift gears. The table shows the position of the transmission gear and the operating status of the clutch and brake.

【table】

[Table] Here, ◯ indicates that each clutch and brake are in an engaged state, and × indicates that they are in a released state. The above clutch and brake 12, 19, 2
A hydraulic circuit of a control device of the present invention, which selectively operates the gears 4, 25, 26, 27, and 40 to perform an automatic or manual speed change operation, will be described based on an embodiment shown in FIG. The hydraulic circuit includes an oil reservoir 100, an oil pump 101, a pressure regulating valve 102, a second pressure regulating valve 103, a throttle valve 200, a manual valve 210, a 1-2 shift valve 220, a 2-3 shift valve 230, and a 3-4 shift valve. 240, a low coast modulator valve 250 that adjusts the hydraulic pressure supplied to the brake 27, an accumulator 2 that smoothly engages the clutch 24;
60. Accumulator 270 for smoothly engaging the clutch 25; Accumulator 280 for smoothly engaging the brake 40; Clutch 2;
4, 25, and a flow control valve 29 with a check valve that controls the flow rate of pressure oil supplied to the brake 27.
0,300,310, a first solenoid valve 320 that is opened and closed by the output of an electric circuit (computer) to be described later and controls the 2-3 shift valve, and controls both the 1-2 shift valve and the 3-4 shift valve. It consists of a second solenoid valve 330 and oil passages that communicate between each valve and the hydraulic servo of the clutch and brake. The hydraulic oil pumped up from the oil reservoir 100 by the oil pump 101 is adjusted to a predetermined oil pressure (line pressure) by the pressure regulating valve 102, and then flows into the oil passages 104 and 10.
3'. The pressure oil supplied to the second pressure regulating valve 103 via the oil passage 103' is supplied to the throttle valve 20.
Depending on the throttle pressure of 0, the torque converter pressure, oil oil pressure, and cooler pressure are regulated to predetermined values. The manual valve 210, which is connected to the oil passage 104, is connected to the shift lever, and is manually operated to switch between P, R, N, D, and the like depending on the range of the shift lever.
Move to positions 3, 2, and L. The table shows oil passage 104 and oil passage 105 to 1 at each shift lever position.
10 is shown. ○ indicates that they are connected.

[Table] The first solenoid valve 320 that controls the 2-3 shift valve 230 closes the valve port 321 when not energized and generates hydraulic pressure in the oil passage 111 that communicates with the oil passage 106 via the orifice 322, and when energized Benguchi 3
21 is opened to discharge the pressure oil in the oil passage 111 from the oil drain port 323. 1-2 shift valve 220 and 3-
The second solenoid valve 330 that controls the 4-shift valve 240 closes the valve port 331 when not energized and opens the oil passage 11 in communication with the oil passage 106 via the orifice 332.
Pressure oil is generated in the oil passage 112, and when energized, the valve port 331 is opened and the pressure oil in the oil passage 112 is discharged from the oil drain port 333. The table shows the relationship between energization and de-energization of the solenoid valves 320 and 330 controlled by the electronic circuit described later in the table and the gear state of the automatic transmission.

[Table] The 1-2 shift valve 220 is equipped with a spool 222 with a spring 221 on one side, and in the first gear, the solenoid valve 330 is de-energized and oil pressure is generated in the oil passage 112, so the spool 222 is moved to the right in the figure. In the second speed, the solenoid valve 330 is energized, the oil passage 112 is evacuated, and the spool 222 is set to the left in the figure. Oil passage 113 in 3rd and 4th speed
Through this, line pressure enters the right end oil chamber 223, and the spool 222 is fixed to the left in the figure. The 2-3 shift valve 230 includes a spool 232 with a spring 231 on one side, and in the first and second speeds, the solenoid valve 320 is energized and the oil passage 111 is energized.
Since no hydraulic pressure is generated, the spool 232 is set to the left in the figure by the action of the spring 231, and in the third and fourth gears, the solenoid valve 320 is de-energized and the oil passage 111 is
Hydraulic pressure is generated and the position is set to the right in the figure. The 3-4 shift valve 240 includes a spool 242 with a spring 241 on one side, and in the first and second speeds, line pressure enters the oil chamber 243 through the oil path 114, and the spool 242 is fixed to the left in the figure. In the third speed, the solenoid valve 330 is energized and the oil passage 112 is depressurized, so the action of the spring 241 causes the spool 2 to
42 is set to the left in the figure, and in the fourth speed, the solenoid valve 330 is de-energized and the spool 242 is set to the right in the figure. In the throttle valve 200, the indicator valve 201 strokes in response to the amount of depression of the accelerator pedal, compressing the spring 203 between the valve 201 and the valve spool 202, etc.
22. When manual valve 210 is in the N position, oil passage 104 communicates with oil passage 115 and clutch 12 is engaged. When manually shifted to D position, oil passage 106
Hydraulic pressure is supplied to the clutch 24, and the first clutch 24 is engaged.
At high speed, the spool 222 of the 1-2 shift valve 220 is on the right side in the figure, the oil passages 116 and 117 communicating with the brakes 26 and 40 are exhausted, and the oil passage 118 communicating with the brake 27 is also supplied with hydraulic pressure. Therefore, the brakes 26, 40, and 27 are released. When the vehicle speed reaches a predetermined level, the solenoid valve 330 is energized by the output of the computer, and 1-
The spool 222 of the second shift valve 220 moves to the left in the figure, and hydraulic pressure is supplied through the oil passages 105 and 117, the brake 40 is engaged, and the oil passage 118 is discharged, causing a shift to the second gear. When the vehicle speed, throttle opening, etc. reach predetermined values, the solenoid valve 320 is de-energized by the output of the computer, and the spool 23 of the 2-3 shift valve 230 is shifted to the 2-3 shift valve 230.
2 moves to the right in the figure, hydraulic pressure is supplied through the oil passages 106 and 113, and the clutch 25 is engaged. At the same time, hydraulic pressure is supplied to the oil chamber 223, and the spool 222 of the 1-2 shift valve 220 moves to the left in the figure. It is fixed in one direction. To shift to the 4th speed, similarly to the above, the solenoid valve 330 is de-energized by the output of the computer, the spool 242 of the 3-4 shift valve moves to the right in the figure, the oil passage 115 is evacuated, and the oil passage 1
20 is supplied with hydraulic pressure, the clutch 12 is released, and the brake 19 is engaged. When the manual valve 210 is in the 3rd position, the 1st, 2nd, and 3rd gears are shifted in the same way as in the D position, but the 3rd to 4th gears are shifted through the oil passages 107 and 114.
Since line pressure enters the right end oil chamber 243 of the shift valve and the spool 242 is fixed to the left in the drawing, no shift to fourth speed occurs. Further, when the manual valve 210 is in the D position and a manual shift to D-3 is performed while the vehicle is running in the fourth speed, a downshift to the third speed is immediately performed. When the manual valve 210 is in the 2nd position, the first
The speed is the same as when the manual valve is in the D position, and in the second speed, oil pressure enters the oil passage 108 and the oil passage 12
1,116, the brake 26 is engaged to apply engine braking. Also the third
When manually shifting to position 2 while driving at high speed,
Upon deceleration to the predetermined speed, the computer output energizes solenoid valve 320, causing a 3-2 downshift. When the manual valve 210 is shifted to the 1 position, oil pressure enters the oil passage 109, line pressure is supplied to the right end oil chamber 233 of the 2-3 shift valve 230, the spool 232 is fixed to the left in the figure, and the spool 232 is immediately 4-
A 2 or 3-2 downshift occurs. The 2-1 downshift is performed by de-energizing the solenoid valve 330 using the output of the computer when the vehicle has decelerated to a predetermined speed. At the same time, the oil pressure in oil passage 109 engages brake 27 via oil passages 119 and 118. An electric circuit (computer) that opens and closes the first and second solenoid valves 320 and 330 as shown in the table in accordance with the vehicle running state will be described with reference to FIG. The electric circuit includes a power supply device 420, a vehicle speed and throttle opening detection device, and solenoid valves 320, 3.
30, and a computer circuit 400 that leads to the driving of 30. The power supply device 420 is connected to a battery via a switch 421, and a position switch 422 attached to a manual lever connects a wire 520 to set the D, 3, 2, and L positions and connect the wire 521.
More power supply (constant voltage power supply device) 42
3, and a constant voltage is supplied from the power supply 423 to each component of the computer 400 through a connection 523. The computer circuit 400 includes a vehicle speed detection device 401, a waveform amplification shaping circuit 402,
DA (digital-analog) conversion circuit 40
3. Throttle position switch 413, throttle opening voltage generation circuit 414, 1-2 shift discrimination circuit 404, 2-3 shift discrimination circuit 406, 3
-4 shift discrimination circuit 408, hysteresis circuit 4
05, 407, 409, solenoid valve 320 opening/closing determination circuit 410, solenoid valve 330 opening/closing determination circuit 412, N-D shift signal generator 415, timer 411, amplifiers 416, 417, and solenoid valves 320, 330. Vehicle speed detection device 401
The detected vehicle speed becomes a sinusoidal waveform signal, which is shaped and amplified into a positive rectangular wave signal by a waveform amplification shaping circuit 402, converted to a DC voltage signal according to the vehicle speed by a D-A conversion circuit 403, and then converted to a DC voltage signal according to the engine load state. The throttle position switch 413 that detects the throttle position is composed of a variable resistor according to the throttle opening degree, and the signal corresponding to the throttle opening degree is converted into a DC voltage by the throttle opening voltage generation circuit 414, and the signal is converted into a DC voltage by the 1st and 2nd shift discrimination circuits. 404, 2-3 shift determination circuit 406, and 3-4 shift determination circuit 408 are entered.
Each discrimination circuit compares the magnitude of the vehicle speed voltage signal and throttle opening voltage signal using, for example, a differential amplifier circuit, and sets the condition for 1-2 shift, 2-3 shift, or 3-4 shift. do. Hysteresis circuits 405, 407, and 409 are used to provide downshift conditions for 2-1 shift, 3-2 shift, and 4-3 shift, respectively. To enable downshifting and prevent hunting in the gear shift range. The solenoid valve 320 opening/closing determination circuit 410 emits an output of 0 (OFF) or 1 (ON) depending on the output of the 2-3 shift discrimination circuit,
The solenoid valve 320 is opened and closed via the amplifier 416. The solenoid valve 330 opening/closing determination circuit 412 uses the outputs of the 1-2 shift discrimination circuit 404, the 3-4 shift discrimination circuit 408, and the timer 41.
An output of 0 or 1 is generated by the output of the N-D shift signal generator via 1, and the solenoid valve 330 is opened/closed via the amplifier 417. The automatic transmission control device of this embodiment uses an electric circuit to open and close two solenoid valves 320 and 330 as shown in the table, and only one solenoid valve is energized in the first gear where the engine speed is low. Since the hydraulic pressure is discharged from the oil passage, the amount of drained oil (drain) in the hydraulic circuit is small, and insufficient supply of pressure oil is prevented. In addition, even if power to the solenoid valve stops due to a failure in the electric circuit during high-speed operation, the manual valve will shift to 4th gear when it is in the D position, and to 3rd gear when it is in the 3rd position, so if the engine is suddenly No brake or engine overruns occur. In addition, in the automatic transmission control device of the present invention, which is equipped with three or more solenoid valves, one solenoid valve is energized in the first gear, and the solenoid valve is de-energized, so that the exhaust gas in the first gear, when the engine speed is low, is energized. Reduce the amount of oil.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing an example of a planetary gear unit of a hydraulic four-speed automatic transmission, FIG. 2 is a block diagram showing the configuration of a hydraulic circuit, and FIG. 3 is a block diagram showing the configuration of an electric circuit. In the figure, 320, 330...Solenoid valve, 40
0...Electric circuit.

Claims (1)

[Claims] 1. An automatic transmission mechanism that has a plurality of hydraulic servos and is capable of achieving at least a low gear, a middle gear, and a high gear by selectively supplying and discharging hydraulic pressure to the hydraulic servos. In a control device for a transmission, an electric circuit has means for generating an electric signal according to the running state of the vehicle, a logic means for generating an output signal according to each gear position based on input from the means, and an output of the electric circuit. a hydraulic circuit that selectively supplies and discharges hydraulic pressure to the hydraulic servo according to a signal; the hydraulic circuit includes a hydraulic power source driven by an engine; 2 oil passage, and is arranged so as to discharge the hydraulic pressure of the first oil passage when energized by the output signal of the electric circuit, and maintain the oil pressure of the first oil passage when not energized. and a first solenoid valve arranged to discharge the hydraulic pressure in the second oil passage when energized by the output signal of the electric circuit and maintain the oil pressure in the second oil passage when not energized. a second solenoid valve provided therein; a first shift valve that is switched to one position when the hydraulic pressure in the first oil passage is maintained and to the other position when the hydraulic pressure is exhausted; a second shift valve that is switched to one position when the hydraulic pressure in the second oil passage is exhausted and switched to the other position when the pressure is maintained; The transmission mechanism achieves a low gear when the first shift valve is in the one position and the second shift valve is in the one position, and the first shift valve is in the other position and the second shift valve is in the one position. When the transmission mechanism is in the one position, the transmission mechanism achieves a middle gear, and when the first shift valve is in the other position and the second shift valve is in the other position, the transmission mechanism achieves a high speed. Hydraulic pressure from the hydraulic source is supplied to and discharged from the hydraulic servo to achieve a shift, and when the second shift valve is in the other position, the first shift valve is in the other position. A control device for an automatic transmission, characterized in that the control device can be switched to the other position regardless of oil pressure in an oil passage. 2. The first shift valve has an oil chamber, and when oil pressure is supplied to the oil chamber, it is switched to the other position regardless of the oil pressure in the first oil path, and the second shift valve is switched to the other position when oil pressure is supplied to the oil chamber. 2. The control device for an automatic transmission according to claim 1, wherein the control device for an automatic transmission is configured to supply hydraulic pressure from the hydraulic pressure source to the oil chamber when the hydraulic pressure source is in the other position.