JPS5917052A - Neutral controller for automatic speed change gear for car - Google Patents

Abstract

PURPOSE:To prevent a car from going back when the car starts on an upward slope by preventing a gear from being set in neutral position even if speed is reduced on the upward slope and stop operation is performed. CONSTITUTION:A car-speed switch 205 transmits ''1'' signal when the car speed is low, and transmits ''0'' signal when the car speed is high. An accelerator switch 207 transmits ''1'' signal when an acclerator 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 tranmits ''0'' signal in other cases. When a car travels on an upward slope, a foam 220 shifts rightward in the figure, and light transmits through said foam part and reaches a transistor 214, which is brought into conduction. When the transistor 214 is in conductive state, ''0'' signal showing the upward slope is output thereby, each input to an AND-circuit 203 does not accord, so the gear is not set in neutral state.

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, which are composed of a torque converter and a gear transmission mechanism such as a planetary gear mechanism, are widely used.
The torque converter used for this purpose includes a pump invera, a turbine runner, and a stator disposed between them, and transmits power to the turbine by circulating fluid, that is, hydraulic oil, from the pump invera driven by an engine.

In such an automatic transmission, when the vehicle is stopped,
Manually 5) It is also possible to put the automatic transmission into neutral by cutting off the power transmission between the gear transmission mechanism and the gear transmission mechanism, or by putting the gear transmission mechanism itself into a idling state. In driving situations where the vehicle starts and stops frequently, it is common practice to maintain the stopped state by stopping the manual operation of shifting the transmission to neutral and placing the torque converter in a stall state each time the vehicle stops. Te. However, due to the stall condition of the torque converter, there are problems such as vibrations occurring in the converter and clipping of the vehicle, and the load for driving the torque converter that is applied to the engine is unavoidable. This will result in an increase in consumption by state.

An automatic transmission intended to solve such problems is described in Japanese Patent Publication No. 11'7-19941. This automatic transmission is designed to automatically shift to neutral under the conditions that the actuator lever is released, the brake pedal is depressed, and the vehicle speed is low.

However, with this known device, even if the vehicle is stopped and swept while traveling uphill at low speed, the vehicle enters a neutral state, which causes the vehicle to move backwards when starting.

Therefore, the present invention utilizes one of the advantages of a transmission using a torque converter, which is that it does not cause backward movement when starting up an uphill slope, while also providing an automatic system that automatically puts the transmission into a neutral state as needed. The purpose is to sweep the neutral control device of the transmission.

The structural features of the present invention include a vehicle speed sensor that detects that the vehicle speed is below a set vehicle speed, a stop operation detection sensor that detects the operation of a device to stop the vehicle, and an inclination sensor that detects that the vehicle is on an uphill slope. The present invention includes a controller that determines a condition in which no output from the inclination sensor is generated and all outputs from the remaining λ sensors are generated, and generates a signal to place the automatic transmission in a neutral state.

According to the present invention, if the vehicle is traveling at a speed lower than the set vehicle speed and the vehicle is traveling uphill even if a stop operation is performed, the transmission is not brought into the neutral state. Therefore, when a starting operation is performed from this state, there is no problem of the axle moving backward, which is preferable in terms of safety.

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 torque converter 10X, a first planetary gear mechanism 12, a λ-th planetary gear mechanism 14, The rotational force of the crankshaft 16 is transmitted to the output side +18 of the torque converter 10 via the torque converter ]O. The output shaft 18 is connected to the connecting gear 22 via the front clutch 2° and to the internal gear 2 (3) of the first planetary gear mechanism 12 via the rear clutch 24I. 22 is connected to the sun gears 21 and 23 of the seventh and first planetary gear mechanisms.Furthermore, the connecting gear 22 is adapted to engage with the brake pant 25, and when engaged, its movement is prevented. be restrained.

The planetary carrier 28 of the first planetary gear mechanism 12 is connected to the internal gear 3° and the output gear 0 of the first planetary gear mechanism.
It is connected to the gear 32. 2nd planetary gear mechanism 1
4, a planetary carrier 84i7J, an o-and-reverse brake 86, and a one-way clutch 88. Further, the internal gear 30 of the first planetary gear mechanism is capable of engaging with the parking gear 40, and when the two engage, the movement of the automatic gear 32 is restricted. Note that the supply of hydraulic oil to the torque converter 10 is performed by an oil pump f+2.

Figure 2 shows a hydraulic control circuit for operating each clutch and brake to obtain the required gear. The hydraulic oil is
The pressure is adjusted by the pressure regulating valve 102 and the select valve 103
guided by.

The select valve 103 has positions /, U, D, N, R, and P, and when the select valve 108 is in the /2.2 and D positions, the pressure line 101t/'i port a of the valve 108
, b, and c. Port a is connected via line 126 to actuator 104 for operating rear clutch 24, and when valve 108 is in the above-mentioned position, rear clutch 24 is held in an engaged state. In addition, port a is connected to the seventh governor valve 106 via the first governor valve 105, and when the vehicle speed exceeds the set value, the line 107
Vehicle speed signal pressure is generated. The vehicle speed signal pressure on the line 107 is determined by the no-yu shift valve 1081. ! -3 is applied to the lift valve 109 and the pressure modifier valve 122 to operate these valves according to the vehicle speed.

Port C is connected to a second lock valve 111, and pressure in line 101 is applied to the extranuclear 111 to maintain the spool of this valve in the upper position in the figure.

The pressure at port b is applied to the second lock valve 111, and when the pressure from port C is not acting on the outer core 111, it acts to push down the spool of the outer core 111 (port a is further connected to the line 112 to the soft valve 108, from which the line 113 is connected to the actuator 1 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 that leads to the maintenance side pressure chamber of No. 14. Furthermore, port C is connected to a 2-3 noft valve 109 via a line 116, and this line 116 is connected to a line 117 when the vehicle speed exceeds a set value and the 2-3 noft valve 109 is activated. .

Line 117 is actuator 1 of brake band 25
When hydraulic pressure is introduced into the pressure chamber, the actuator 114 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 103 connects the pressure line 101 in the / position to
and has a port d leading to line 11
9 and reaches the /-Ω shift valve 108, and then the line 1
20 and is connected to the actuator 121 of the low and reverse brake 86. Furthermore, the hydraulic control circuit includes a pressure cammodifier valve 122 and a downshift valve 12.
3. Although a throttle backup valve 124 and a vacuum throttle valve 125 are provided, 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 control 130 is further provided in the pressure line 126.
0 is a solenoid valve, which is normally open (solenoid)
” line 126 when 1808 is energized by the signal
cut off.

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 it does not contribute to operating power transmission. Note that when pressure is introduced to both the engagement side and the release side of the brake gun 25, the brake operates on the release side due to the difference in area of the actuator.

Furthermore, the /-λ shift valve 108 and the 2-3 lift valve 1
09 is a solenoid valve, and a suitable electronic circuit can be used to operate these to obtain the required gear stage.
In this case, the governor valves 105, 106 are not required.

Referring to FIG. 3, the control circuit for the neutral control valve 130 is shown, and the solenoid 130a for the neutral control valve 130 is connected to the power source terminal 200 on one side, and the traction nostar 201 on the other side. connected to the collector. A diode 202 is connected in parallel with this solenoid 1308. Solenoid 180a is energized when transistor 201 conducts, thereby actuating neutral control valve 130 and closing pressure line 12.
6 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. Transistor 201 is of NPN type and becomes conductive when a predetermined voltage is applied to its base. This transistor Z
The base of OI is connected to the output terminal of AND circuit 203, and when the output of AND circuit 203 is /, the base voltage exceeds a predetermined value and transistor 201 becomes conductive.

One input terminal of AND circuit 2.03 is connected to vehicle speed switch 205 via amplifier 204. The vehicle speed switch 205 is attached to the governor valve 105 or 106 and changes the vehicle speed or low speed, for example /Q Km/h.
When the vehicle speed is below, the vehicle speed switch 205 outputs a signal of /, and when the vehicle speed is higher than that, a signal of 0 is output. The seven input terminals of the AND circuit 203 are connected via an amplifier 206 to an accelerator switch 207 as one of the stop operation detection sensors, and the accelerator switch 207 outputs a signal of l when the accelerator pedal is not depressed. . AND circuit 203
The seven input terminals are connected to the output terminal of the OR circuit 2()8, and one input terminal of the OR circuit 208 is connected to the brake switch 210 as one of the stop operation detection sensors via the amplifier 209. The other input terminal is connected via an amplifier 211 to a handbrake switch 212 as one of the stop operation detection sensors.

The brake switch 211 outputs a signal when the brake is fully depressed, and the handbrake switch 212 outputs a signal when the handbrake is pulled. Therefore, the OR circuit 208 outputs a signal of / when the brake is stepped on or the handbrake is pulled, and a signal of 0 otherwise. Furthermore, the seven input terminals of the AND circuit 203 are connected to the collector of a phototransistor 214, such as a light receiving element, via a low pass filter 218. transistor 21
4 is also connected to the power supply terminal 21 via a resistor 215.
6 and its emitter is grounded. When the phototransistor 214 receives light, the base becomes a predetermined voltage and becomes conductive. When the transistor 214 becomes conductive, the potential at the collector decreases due to the voltage drop across the resistor 215, and a low level signal, that is, a 0 signal is output.

In other words, an output indicating an uphill slope is being emitted. For example, a light emitting diode 217 is used as a light emitting element connected to the base of this transistor 214, and this light emitting diode 217 is connected to a suitable power supply terminal 218. This light emitting diode 217 is connected to the phototransistor 2
A shielding case 221 containing a light-shielding liquid 219 and air bubbles 220 is provided between 14 and 14. When the vehicle runs on a flat road or downhill, this liquid 218 By light emitting diode 217-7
Light to the autotransnoster 214 is blocked, and the transistor 214 is in a non-conducting state. When the vehicle travels uphill, the bubble 220 moves to the right in the diagram, allowing light to pass through the bubble and reach the transistor 214, which becomes conductive.

When the transistor 214 is conductive, a 0 signal indicating that the slope is uphill is output, so the inputs of the AND circuit 203 do not match and the neutral state does not occur. That is, the diode 217, the transistor 214, and the case 221 constitute a tilt sensor.1. The vehicle speed becomes low on an uphill slope, and even if a stop operation is performed, the vehicle does not return to a neutral state.Therefore, there is no problem of the vehicle backing up when starting on an uphill slope. In addition,
Low·'? The filter 213 is affected by vibrations of the vehicle body, etc.
This serves to prevent malfunctions such as when the bubble 22J0 moves and the transistor 214 becomes conductive, resulting in a neutral state.

Further, the neutral control valve 130 may be installed in the pressure line 1ull.

In the above embodiment, all three switches, the accelerator switch, the brake switch, and the handbrake switch, are used as the stop operation detection sensor, but it is also possible to use only one switch (

[Brief explanation of drawings]

FIG. 1 is a pressure control circuit diagram of an automatic transmission according to an embodiment of the present invention, and FIG. 3 is a control circuit for a solenoid valve for neutral control according to an embodiment of the present invention. Description of symbols 10...Torque converter, 12...First planetary gear mechanism, 14...Year planetary gear mechanism, -20...Front clutch, 24...Rear clutch, 25...Brake band, 36...Low and reverse brake, 13
0...Neutral control valve, 205...Vehicle speed switch,
207...Accelerator switch, 21O...Brake switch, 212...Handbrake switch, 213
...Rono! Sfilter, 214... Phototransnoster, 217... Light emitting diode. Patent applicant: Toyo Kogyo Co., Ltd.

Claims (1)

[Claims] In the automatic transmission comprising a torque converter, a planetary gear mechanism, a plurality of frictional engagement members for switching a power transmission path of the planetary gear mechanism, and a fluid actuator for operating on/off of the frictional engagement members, An electromagnetic means for controlling the supply and discharge of fluid to the fluid actuator, a vehicle speed sensor for detecting that the vehicle speed is lower than a set vehicle speed, a stop operation detection sensor for detecting the operation of a device to stop the vehicle, and the fact that the vehicle is on an uphill slope. an inclination sensor that detects the inclination sensor, and determines a condition under which the inclination sensor does not generate an output and all outputs from the remaining λ sensors are generated, and generates a signal that activates the electromagnetic means and places the automatic transmission in a neutral state. A neutral control device for an automatic transmission, characterized in that it is equipped with a controller that generates a signal.