JPS5917050A - Neutral controller of automatic speed change gear for car - Google Patents

Abstract

PURPOSE:To permit traveling of a car with the effect of engine brake, by preventing a shift lever from being positioned at neutral position so far as the shift lever is positioned within a low-speed range even if the car travels in a low speed and brake operation is executed. CONSTITUTION:A car-speed switch 205 transmits ''0'' signal when a car speed is high and transmits ''1'' signal when the car speed is low. An accelerator switch 207 transmits ''1'' signal when an accelerating pedal is not stepped-in. An OR- circuit 208 transmits ''1'' signal when a brake pedal is stepped-in or a hand brake is pulled, and transmits ''0'' signal in other cases. An OR-circuit 213 transmits ''1'' signal when shift position is D or 2 position. When a shift lever is in the low-speed range position other than D range or 2 range, the output of the OR-circuit 213 is 0, so each input to an AND circuit 203 does not accord, so neutral state is not formed even if other inputs accord each other. Therefore, traveling with the effect of engine brake is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a neutral control device for an automatic transmission that automatically puts the automatic transmission into a neutral state under certain conditions.

Automatic transmissions that combine a fluid torque converter and a gear transmission mechanism such as a planetary gear mechanism are widely used.・
The engine-driven pump inflator circulates fluid, or hydraulic oil, to transmit power to the turbine.

In such an automatic transmission, when the vehicle is stopped,
It is also possible to put the automatic transmission into neutral by manually cutting off the power transmission between the torque converter and the gear transmission mechanism, or by letting the gear transmission mechanism itself idle, but this will prevent the vehicle from starting and stopping. In frequently repeated driving situations, it is difficult to manually put the transmission into neutral each time the axle stops, but by stopping the transmission output shaft with the brake and placing the torque converter in a stall state, the axle can be brought into a stopped state. It is common to maintain However, under such a torque converter stall condition, there are problems such as vibrations occurring in the converter and vehicle creep, and the torque converter drive load on the engine is inevitably large. This results in increased fuel consumption.

As an automatic speed train intended to solve such problems, Tokko Akira <I! There is something written in 7-/q9 Otsu λ Koha. This automatic transmission automatically shifts to neutral when the accelerator pedal is released, that is, it is fully closed, the brake pedal is depressed, and the vehicle speed is low. It has become. However, with this known system, there is a problem in that the engine brake becomes ineffective because the vehicle may enter a neutral state even when descending a downhill slope by shifting to a low speed range.

Therefore, the present invention provides neutral control for an automatic transmission that can sufficiently apply engine braking, and also automatically puts the transmission into a neutral state when appropriate, thereby eliminating torque converter vibration and vehicle creep. The purpose is to provide equipment.

The configuration features of the neutral control device of the present invention include a vehicle speed sensor that detects that the vehicle speed is below a set vehicle speed, an accelerator fully closed sensor that detects that the amount of accelerator pedal depression is zero, and a brake pedal sensor that detects that the accelerator pedal depression amount is zero. A brake sensor detects that the shift lever is depressed, a shift range sensor detects that the shift lever is in the low speed range, and the remaining three shift range sensors do not output any output.
The present invention is characterized by comprising a controller that determines a condition under which all outputs from two sensors are generated and issues a signal to place the automatic transmission in a neutral state.

According to the present invention, even if the vehicle is traveling at low speed while applying the brakes, the neutral state will not occur if the shift lever is in the low speed range. Therefore, in such a case, by keeping the gear shift lever in the low speed position, it is possible to shift the vehicle while applying the brake.

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

Referring to FIG. 1, there is shown a schematic diagram of an automatic transmission according to an embodiment of the present invention, which includes a fluid torque converter 10, a first planetary gear mechanism 12, a λ planetary gear mechanism 14, the rotational force of the crankshaft 16 is transmitted to the torque converter 10 via the torque converter 10.
is transmitted to the output shaft 18 of. The output shaft 18 is connected to a connecting shell 22 via a front clutch 20 and to an internal gear 26 of the first planetary gear mechanism 12 via a rear clutch 24. The connecting shell 22 is the first planetary gear mechanism Sangya 2.
1,28.

Furthermore, the connecting shell 22 is connected to the brake band 2.
5, and when engaged, its movement is restricted. The planetary carrier 28 of the first planetary gear mechanism 12 is connected to the internal gear 30 and output gear 82 of the second planetary gear mechanism. Second
The planetary carrier 34 of the planetary gear mechanism 14 has a low and reverse brake 36 and a one-way clutch 88.
It is now possible to be restrained by Further, the internal gear 80 of the second planetary gear mechanism is designed to be able to engage with the king gear 40, and when both engage, the movement of the output gear 32 is restricted. Oil pump 4 supplies hydraulic oil to gear 10.
2.

FIG. 2 shows a hydraulic control circuit for operating each clutch and brake to obtain a required gear stage. In this control circuit, a pressure line 1 (l to The pressure of the discharged operating shaft is adjusted by the pressure regulating valve 102 and guided to the select valve 103.

The select valve 108 is /,2. D, N, R, P positions, and when the select valve 108 is in the /, 2 and D positions, the pressure line 1'01 is connected to the ports (a, b) of valve 1()3.
, c. Port a is connected via line 126 to actuator 104 for actuating rear clutch 24, and when valve 108 is in the above-mentioned position, rear clutch 24 is held in an engaged state. Further, port a is connected to the first governor valve 106 via the first governor valve 106, and when the vehicle speed exceeds a set value, a vehicle speed signal pressure is generated in the line 107. The vehicle speed signal pressure on line 107 is /
-2 shift valve 1081.2-3 shift valve 109 and pressure modifier valve 122 to operate these valves according to vehicle speed.

Port c is connected to second lock valve 111 and line 1
A pressure of 0.01 is applied to the valve 111 to maintain the valve spool in the upper position in the figure.

The pressure at port b is applied to second lock valve 111 and acts to push the spool of valve Ill downward when pressure from port c is not acting on valve 111. Port a is further connected via a line 112 to the λ shift valve 108, from which the line 118 is connected to the engagement of the actuator 114+ of the brake band 25 when the spool of the second lock valve 111 is in the upper position. It is connected to a line 115 leading to the mating pressure chamber. Furthermore, port C is connected to the λ-3 shift valve 109 via a line 116, and this line 116 indicates that when the vehicle speed exceeds the set value -C, the 2-3 shift valve 109 is activated.
Connected to line 117 at 9 o'clock.

Line 117 is actuator 1 of brake band 25
When hydraulic pressure is introduced into the pressure chamber, the actuator 1]4 operates the brake band 25 in the release direction against the pressure in the engagement pressure chamber. Also, the pressure in line 117 is
This clutch 20 is also guided to the actuator 118 of
engage.

The select valve 1()3 is connected to the pressure line 10 in the 1 position.
1, and this port d leads to line 1
It reaches the /-2 shift valve 108 via line 19 and is further connected to the actuator 121 of the low and reverse brake 36 via line 120. Furthermore, the hydraulic control circuit includes a pressure cammodifier valve 122, a downshift valve 1
23, a throttle backup valve 124 and a vacuum throttle valve 125 are provided, but the configuration and operation of the control circuit described above are the same as those conventionally known, so a detailed explanation will be omitted.

In this example, a neutral valve 1 is further connected to the pressure line 126.
80 are provided. Neutral valve 130 is a solenoid valve that is normally open and shuts off line 126 when solenoid 180a is energized by a signal.

In the above control circuit, the relationship between the gear position and the operation of the clutch and brake is shown in the table.

The ■ symbol in the table indicates that even if it operates, it does not contribute to power transmission. Note that when pressure is introduced to both the engagement side and the release side of the brake band 25, the brake operates on the release side due to the difference in area of the actuator. Furthermore, the l-λ shift valve 108 and the 2-3 shift valve 109 can be configured to be solenoid valves and operated using an appropriate electronic circuit to obtain the required gear stage. is panaben 1
05.1.06 becomes unnecessary.

The third (refer to section I) is the neutral control valve 1, 30.
The control circuit for the neutral control valve 180 is shown.
The solenoid 130a is connected to the power supply terminal 200 at one end, and the other end is connected to the collector of the transistor 201. A diode 202 is connected in parallel with this solenoid 130a. Solenoid 130a is energized when transistor 201 becomes conductive, thereby actuating neutral control valve 130 to close pressure line 1.
26 is cut off, hydraulic pressure supply to the rear clutch 24 is stopped, and the automatic transmission is placed in a neutral state. In this case, the diode 202 serves to prevent overcurrent from flowing into the transistor 201 due to the back electromotive force of the solenoid. The transistor 201 is of the NPN type and becomes conductive when a predetermined voltage and voltage are applied to the base. The emitter of this transistor 20'1 is grounded, and the base is connected to the output terminal of the AND circuit 203.
When the output of B is /, the base voltage exceeds a predetermined value and transistor 201 becomes conductive. One input terminal of the AND circuit 203 is connected to the vehicle speed switch 20 via a buffer 204.
5. The vehicle speed switch 205 is attached to the governor valve 105 or 106, and when the vehicle speed becomes low, for example, 10 km/h or less, the vehicle speed switch 205Id, / outputs a signal of 0 when the vehicle speed is higher than that.

One input terminal of the AND circuit 20B is connected to an accelerator switch 207 via a buffer 206, and the accelerator switch 207 outputs a signal when the accelerator pedal is not depressed. One input terminal of the AND circuit 20B is connected to the output terminal of the OR circuit 208, one input terminal of the OR circuit 208 is connected to the brake switch 210 via the buffer 209, and the other input terminal is connected to the brake switch 210. via handbrake switch 2
12. The brake switch 211 outputs a signal when the brake lever is depressed; and the handbrake switch 212 outputs a signal when the handbrake is pulled. Therefore, the OR1ift path 208 outputs a signal of 1 when the brake is stepped on or the handbrake is pulled, and a signal of 0 otherwise. Furthermore, the seven terminals of the AND circuit 203 are connected to the output terminals of another OR circuit 218, and one input terminal of this OR circuit 213 is connected to the inverter 2.
] 1 to a shift range sensor 215 that indicates whether or not the 7-ft position of the shift lever is in the D range;
The other input terminal is connected via an inverter 216 to a left range sensor 217 that indicates whether the shift position is in the 2nd range. , the shift lens sensor 217 outputs a signal when the shift position is in the forward position. In other words, there is no output indicating the /range position. Therefore, the OR circuit 213 indicates that the shift position is D or! Gives a signal when in position.

Therefore, when the shift position is in the D range or J range, the vehicle speed becomes low or the accelerator pedal is released, and when the brake pedal is depressed, the AND circuit inputs match and the automatic transmission is in the neutral state. be made into However, if the shift lever is in a low speed range position other than D range or lunge, for example / range position, an output indicating the / range position is generated. In the circuit of this embodiment, the output of the OR circuit 213 is 0, so the AND circuit 2
The input of 08 does not match, and even if the other inputs match, the neutral state will not be achieved. In this case,
It is possible to drive while applying engine braking.

Note that the neutral control valve 130 is not limited to the illustrated position, but may be installed in the pressure line 101.

In the above embodiment, only / is detected as a low-speed lens, but / / lens is detected as low-speed lens.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an automatic transmission according to an embodiment of the present invention, FIG. 2 is a hydraulic control circuit diagram of the automatic transmission of FIG. 1,
FIG. 3 shows a control circuit for a neutral control solenoid valve according to a -/l embodiment of the present invention. Explanation of symbols 10...torque converter, 12.first planetary gear mechanism, ■4...first planetary gear mechanism, 20..front clutch, 24..rear clutch, 25.brake band, 86..・Low and reverse brake, ■80・
...neutral control valve, 205...vehicle speed switch,
207... Accelerator switch, 21O... Brake switch, 212... Handbrake switch, 21
5.217...Shift range sensor. Patent applicant: Toyo Kogyo Co., Ltd.

Claims (1)

[Claims] A fluid torque converter, a planetary gear mechanism, a plurality of frictional engagement members for switching a power transmission path of the planetary gear mechanism, a frictional engagement member for intermittent transmission of the fluid torque converter output to the planetary gear mechanism; A fluid actuator for operating the frictional engagement member, an electromagnetic means for controlling supply and discharge of fluid to the fluid actuator, and at least a D lens, lunge, and range for limiting the highest speed of the planetary gear mechanism. In an automatic transmission equipped with a gear shift lever, the automatic transmission includes a vehicle speed sensor that detects that the vehicle speed is below a set vehicle speed, an accelerator fully closed sensor that detects that the amount of accelerator pedal depression is zero, and a brake pedal that is A brake sensor detects that the gear lever is depressed, a shift range sensor detects that the shift lever is in the low speed range, and an output from the shift range sensor is not emitted, and output from the remaining three sensors is detected. 1. A neutral control device for an automatic transmission, comprising: a controller that issues a signal to activate an electromagnetic means and place the automatic transmission in a neutral state by determining conditions under which all of the above occur.