JPS6333585B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a control device for an automatic transmission, and more particularly 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 constructed by combining a torque converter and a gear transmission mechanism such as a planetary gear mechanism, are widely used in automobiles. , which circulates fluid, ie, hydraulic oil, from a pump impeller driven by the engine to the turbine to transmit power to the turbine. In such an automatic transmission, when the vehicle is stopped, power transmission between the torque converter and the planetary transmission mechanism is manually cut off, or the planetary transmission mechanism itself is put into a idling state to stop the automatic transmission. It is possible to set the transmission to neutral, but in driving conditions where the vehicle starts and stops frequently, it is cumbersome to manually set the transmission to neutral each time the vehicle stops, and it is necessary to use the brake to stop the transmission output shaft and reduce torque. It is common to maintain a stopped state of the vehicle by placing the converter in a stalled state. However, under such a torque converter stall condition, there are problems such as vibrations occurring in the converter and vehicle creep, and the load on the engine to drive the torque converter inevitably increases. This results in increased fuel consumption. An automatic transmission intended to solve these problems is described in Japanese Patent Publication No. 19962/1983. This automatic transmission automatically shifts to neutral under the conditions that the accelerator pedal is released, that is, the accelerator is fully closed, the brake pedal is depressed, and the vehicle speed is low. It's summery. Therefore,
In this device, when the vehicle is stopped or at an extremely low speed, depressing the brake pedal brings the vehicle into a neutral state, and when the vehicle is released from the pedal, the neutral state is released. in this case,
Is the idle speed set high due to the operation of the idle up mechanism like when operating the cooler?
Alternatively, under driving conditions where the engine speed is rising due to the operation of the brake pedal, etc., when the brake pedal is released the next time the brake pedal is started, the transmission changes from neutral to forward drive, so the high engine speed is directly transmitted to the vehicle. You will feel a shock as if it suddenly jumps out. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a neutral control device that can automatically bring an automatic transmission into a neutral state as needed and can prevent a shock when starting the vehicle. The present invention provides an automatic transmission including a fluid torque converter, a planetary gear mechanism, and a plurality of frictional engagement members for switching a power transmission path of the planetary gear mechanism, in which an output of the fluid converter is transferred to the planetary gear mechanism. A friction engagement member for intermittent transmission, a fluid actuator for operating the friction engagement member, an electromagnetic means for controlling supply and discharge of fluid to the fluid actuator, and a vehicle speed detection means for detecting a vehicle speed below a set vehicle speed. , an accelerator fully closed detection means for detecting a fully closed accelerator, a brake detection means for detecting brake operation, an idling detection means for detecting an idling state when the idle is not turned up, and receiving outputs from the four detection means. The automatic transmission is characterized by comprising a controller that determines only the conditions under which all outputs are generated and issues a signal to operate the electromagnetic means and bring the automatic transmission into a neutral state. Therefore, in the present invention, even if the vehicle speed decreases below a predetermined value and the brake pedal is depressed, the state is not set to neutral, and further, the engine speed is reduced to the normal idling speed. be placed in a neutral state. That is, when the engine speed is higher than the normal idling speed during idling up, for example, when the engine brake is activated, the transmission is not brought into a neutral state but is placed into a stall state, that is, a forward drive state. Therefore, in this case, when the brake is released, the vehicle continues to move forward. As a result, it is possible to eliminate the problem of the vehicle jumping out, which occurs when switching from a neutral state to a forward drive state at a high engine speed. and,
If the accelerator pedal is not depressed, the vehicle speed is below the set vehicle speed, the brakes are activated, and the engine speed has fallen to the normal idling speed, the gear shift Since the machine is brought into a neutral state, problems such as torque converter vibration and vehicle creep can be resolved, and fuel consumption during stoppage can be reduced. Furthermore, even if the transmission is switched from such a neutral state to a forward drive state at the time of starting, since the engine speed is low in the idling state at this time, no shock occurs at the time of starting. 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 10, a first planetary gear mechanism 12, a second planetary gear mechanism 14, The rotational force of the crankshaft 16 is transferred to the torque converter 1.
0 to the output shaft 18 of the torque converter 10. 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 connected to sun gears 21 and 23 of the first and second planetary gear mechanisms. Furthermore, the connecting shell 22 is adapted to engage with the brake band 25, 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 of the second planetary gear mechanism.
and an output gear 32. Planetary carrier 34 of second planetary gear mechanism 14
can be restrained by a low and reverse brake 36 and a one-way clutch 38. Further, the internal gear 30 of the second planetary gear mechanism is adapted to engage with the parking gear 40, and when the two engage, the movement of the output gear 32 is restricted. Note that hydraulic oil is supplied to the torque converter 10 by an oil pump 42. FIG. 2 shows a hydraulic control circuit for operating each clutch and brake to obtain a required gear. In this control circuit, a pressure line 1 is connected to an oil pump 42 driven by an engine output shaft.
The pressure of the hydraulic oil discharged at 01 is adjusted by a pressure regulating valve 102 and guided to a select valve 103.
The select valve 103 has positions 1, 2, D, N, R, and P, and when the select valve 103 is in the 1, 2, and D positions, the pressure line 101 is connected to the valve 103.
It communicates with ports a, b, and c of. Port a is connected via line 126 to actuator 104 for actuating rear clutch 24, which is held engaged when valve 103 is in the position described above. Further, port a is connected to the first governor valve 106 via the second governor valve 105, and when the vehicle speed exceeds a set value, the line 10
7, a vehicle speed signal pressure is generated. The vehicle speed signal pressure on the line 107 is applied to the 1-2 shift valve 108, the 2-3 shift 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 the pressure in line 101 is applied to the valve 111 to maintain its spool in the upper position in the figure. The pressure at port b is controlled by the second lock valve 111.
is applied to the valve 111 so that pressure from port c is applied to the valve 111.
When the valve 111 is not acting, it acts to push the spool of the valve 111 downward. Port a is further connected to the 1-2 shift valve 108 via a line 112, and a line 113 from the shift valve 108.
When the spool of the second lock valve 111 is in the upper position, the line 115 leading to the engagement side pressure chamber of the actuator 114 of the brake band 25 is
connected to. Additionally, port c is line 116
It is connected to the 2-3 shift valve 109 through
This line 116 indicates that the vehicle speed exceeds the set value by 2-3
It is connected to line 117 when shift valve 109 is actuated. The line 117 is connected to the release side pressure chamber of the actuator 114 of the brake band 25, and when hydraulic pressure is introduced into the pressure chamber, the actuator 114 moves the brake band 25 in the release direction against the pressure of the engagement side pressure chamber. Activate. Also,
Pressure in line 117 is also directed to actuator 118 of front clutch 20, causing it to engage. The select valve 103 has a port d leading to the pressure line 101 in one position, and this port d
reaches the 1-2 shift valve 108 via line 119, and further via line 120 to the low and
A reverse brake 36 is connected to the actuator 121. Further, the hydraulic control circuit is provided with a pressure modifier valve 122, a downshift valve 123, a throttle backup valve 124, and a vacuum throttle valve 125, but the configuration and operation of the control circuit described above are conventional. Since it is the same as a known one, detailed explanation will be omitted. In this example, a neutral valve 130 is further provided in the pressure line 126. This neutral valve 130 is a solenoid valve, and is normally in an open state.
Solenoid 130a interrupts line 126 when energized by the 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 below.

【table】

[Table] The mark 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 band 25, the brake operates on the release side due to the difference in area of the actuator.
Furthermore, the 1-2 shift valve 108 and the 2-3 shift valve 109 can be configured to be electromagnetic valves and can be operated using an appropriate electronic circuit to obtain a desired gear stage. In this case, the governor valve 105,1
06 becomes unnecessary. Referring to FIG. 3, a control circuit for a solenoid 130a for a neutral control valve is shown in accordance with one embodiment of the present invention. One terminal 2 of ignition switch 201
01a is connected to a battery power supply 202.
When the ignition switch 201 is activated, the contacts 201b, 201c, 201d, 20
They are connected in the order of terminals 1e and 2e.
When the power terminal 201b is connected to 01e, the starter is activated and the engine is started. Vehicle speed switch 203, accelerator switch 205, brake switch 207, handbrake switch 208
and one terminal of the switch 209 are connected to resistors 220, 221, 222, 223, 22, respectively.
4 to the terminal 201b of the ignition switch 201, and the other terminals of these switches are each grounded. moreover,
One terminal of the vehicle speed switch 203 is connected to one terminal 204a of an AND circuit 204 via an inverter. This vehicle speed switch 203 is turned ON when the vehicle speed is low, for example, 8 to 15 km/h or less. In addition, the accelerator switch 20
One terminal of 5 is also connected to one input terminal 204b of the AND circuit 204 via an inverter. This accelerator switch 205 is turned on when the accelerator pedal is not depressed. Brake switch 207 connects to OR circuit 21 via an inverter.
1, and remains ON when the brake pedal is depressed. The handbrake switch 208 is connected to the OR circuit 211 via an inverter.
It is connected to and turns ON when the handbrake is applied. The switch 209 connects one input terminal 20 of the AND circuit via an inverter.
4d, and this switch 209 is turned on when the switch 209 is not operating. OR
The output terminal of the circuit 211 is connected to one input terminal 204c of the AND circuit 204. The output terminal of the AND circuit 204 is connected to the input terminal of another AND circuit 210. The output terminal of the timer 206 is connected to the other input terminal of the AND circuit 210.
The output terminal of the AND circuit 210 is connected to the base of an NPN transistor 212. The emitter of the transistor 212 is grounded, and the collector is connected via a terminal A to a solenoid 130a of a solenoid valve 130 for neutral control, and this solenoid 130a is connected to a power terminal 201b of an ignition switch 201. The terminal 201b of the ignition switch 201 is connected to a fast idle solenoid 214 and a control solenoid 215 for a magnetic clutch for the compressor of the cooler via a relay 213 for the air conditioner. When the fast idle solenoid 214 is energized, the engine is in an idle up state. Further, when the solenoid 215 is energized, the magnetic clutch is connected and the compressor for the cooler is operated by the engine power. The ignition switch 201 has yet another terminal 20
1d, and this terminal 201d is connected to relay 2.
It is connected to an air conditioner switch 217 via a No. 13 solenoid 213a. Further, a terminal 201d of the ignition switch 201 is connected to an indicator light 216 indicating that the air conditioner is operating, and the other terminal of the indicator light 216 is connected to an air conditioner switch 217. This air conditioner switch 217 is further connected to one input terminal 204e of the AND circuit 204. Now, by operating the ignition switch 201, when the terminals 201a and 201b are connected, each switch 203, 205, 207, 2
Power and voltage are applied to one terminal of 08 and 209, respectively. In this case, when the vehicle is running at normal speed, at least the vehicle speed switch 203 is
Since it is OFF, the voltage signal input to one input terminal 204a of the AND circuit 204 is inverted and becomes a low level. Therefore, AND circuit 20
Since the inputs of 4 do not match and the output thereof becomes low level, the inputs of AND circuit 210 also do not match, and a low level signal is applied to the base of transistor 212, making transistor 212 non-conductive.
That is, the solenoid 130a is not energized and the automatic transmission is not in the neutral state. In this driving state, for example, when attempting to stop the vehicle at a traffic light, the driver takes his foot off the accelerator pedal and depresses the brake pedal. By this operation, the accelerator switch 205
and the brake oil pressure switch is turned on. If this state continues, the vehicle speed decreases and eventually reaches zero. In this case, the vehicle speed is a constant value, for example 8~
Vehicle speed switch 203 turns on when the speed is below 15km/h.
become. In this case, due to the voltage drop across the resistors 220 and 221, the input terminals 204a and 204a of the AND circuit 204
The signal input to 204b becomes high level. Furthermore, since the OR circuit 211 outputs a high level signal, the input terminal 204 of the AND circuit 204
A high level signal is input to 4c. At this time, if the switch is not operating, the switch 209 is on, so it is inverted and becomes a high level, which is input to the AND circuit 204. Also,
In this case, the air conditioner switch is turned off, so the input to terminal 204e is at a high level. Therefore, at this time, the output of the AND circuit 204 becomes high level and is input to the AND circuit 210. One terminal of the accelerator switch 205 and the brake switch 207 is also connected to a timer 206, and this timer 206 sets the time when one terminal of these switches 205, 207 becomes low level for a predetermined period of time, e.g. 0.1~ Emit an output signal when 0.2 seconds have elapsed. Due to this
The inputs of AND circuit 210 match, and its output becomes high level. Therefore, a high level voltage is applied to the base of transistor 212, transistor 212 becomes conductive, and solenoid 130a is energized. As a result, the solenoid valve 1 for neutral control
30 is activated, the hydraulic pressure supply to the rear clutch 24 is cut off, and the automatic transmission is placed in a neutral state. In this case, the hydraulic pressure is applied to the rear clutch 24.
Only the supply to is cut off. The reason for this is that when performing the neutral control in this example, when the speed is low,
That is, this is because the automatic transmission is in the first gear. However, a solenoid valve 130 for neutral control can also be provided in the pressure line 101, in which case the hydraulic pressure supply to all friction elements of the gear transmission mechanism can be cut off. Next, operate the ignition switch 201 to connect the power terminal 201a to the other terminals 201c and 201a.
01d, when the air conditioner switch 217 is turned on, the relay 213 is activated, the magnet solenoid 215 and the fast idle solenoid 214 are energized, and the indicator light 216 lights up. This results in
The compressor clutch of the cooler is connected to the engine, the compressor is started, and the fast idle solenoid is energized to activate the idle up mechanism and increase the idle speed. At this time, since the air conditioner switch 217 is turned on, the terminal 204e of the AND circuit 204 goes to a low level, so the inputs of the AND circuit 204 do not match and the automatic transmission is not in the neutral state. It should be noted that when the chi-yoke is operating, the chi-yoke switch is turned off, and in this case as well, the inputs of the AND circuit 204 do not match, so the neutral state is not achieved as described above. In this example, the signals input to the AND circuit 204, that is, the vehicle speed switch 203, the accelerator switch 205, the brake switch 207,
Handbrake switch 208, brake switch 209, and fast idle solenoid 21
The signal from 4 essentially constitutes a normal, ie, non-idle-up, idle state detection means. When the signal for detecting this idling state satisfies a predetermined condition, the solenoid 1 of the solenoid valve 130 for neutral control is activated.
30a is excited and a neutral state is achieved. In other words, even if the vehicle speed is below a predetermined value, the accelerator is released, and the brake is depressed, if the engine brake, cooler, etc. are operating, the idle speed will be higher than normal, so the neutral controlled to prevent this from happening. This makes it possible to solve the problem of the vehicle jumping out or the like due to switching from the neutral state to the forward drive state when the engine speed is high. Further, under normal idling conditions, the transmission can be reliably shifted to a neutral condition, thereby improving fuel efficiency and eliminating problems such as creep. FIG. 4 is a flowchart when the above control is performed using a microcomputer. In this case, similar effects can be obtained by incorporating the above control contents into a microcomputer.

[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, and FIG. 3 is a diagram of a hydraulic control circuit of the automatic transmission according to an embodiment of the present invention. FIG. 4, a control circuit diagram of a solenoid valve for neutral control, is a flowchart when performing neutral control according to the present invention using a microcomputer. Explanation of symbols, 10...Torque converter, 12
...First planetary gear mechanism, 14...Second planetary gear mechanism, 20...Front clutch, 24...Rear clutch, 25...Brake band, 36...Low and reverse brake, 130...Neutral control valve, 201 ...Ignition switch,
202...Battery, 203...Vehicle speed switch,
205...Accelerator switch, 207...Brake oil pressure switch, 208...Hand brake switch, 209...Yoke switch, 214...
Fast idle solenoid.

Claims (1)

[Claims] 1 Fluid torque converter, planetary gear mechanism,
In an automatic transmission consisting of a plurality of frictional engagement members that switch the power transmission path of the planetary gear mechanism,
a friction engagement member for intermittent transmission of the fluid converter output to the planetary gear mechanism; a fluid actuator for operating the friction engagement member; and electromagnetic means for controlling supply and discharge of fluid to the fluid actuator; A vehicle speed detection means for detecting a vehicle speed below a set vehicle speed, an accelerator fully closed detection means for detecting a fully closed accelerator, a brake detection means for detecting brake operation, and an idling detection means for detecting an idling state when the vehicle is not idling up. The automatic transmission is characterized by comprising a controller that receives outputs from the four detection means, determines only the conditions under which all outputs are generated, and issues a signal to activate the electromagnetic means and bring the automatic transmission into a neutral state. Neutral control device for vehicle automatic transmission.