JPS5934050A - Neutral control device of automatic speed change gear for car - Google Patents

Abstract

PURPOSE:To prevent unnecessary and frequent changeover between neutral condition and a traveling range by setting an automatic speed change gear in the neutral condition through use of a timer part only when a stoppage operation is maintained for a definite time during a low car speed. CONSTITUTION:An automatic speed change gear is changed over to neutral condition by cutting off a rear clutch through exciting a solenoid valve 27 provided in an oil pressure circuit to a rear clutch. Further, the captioned gear is provided with a car speed sensor 58 which detects the car speed being below the set speed, accelerator full closure detection sensor 59, footbrake operation detection sensor 60 and parking brake operation detection sensor 61. When output is sent out from each sensor 58, 59 and also from at least one of sensors 60, 61, a timer circuit 72 is operated through AND circuit 67, and a transistor 73 is placed in ON state by means of an output of AND circuit 71 after the set time of the circuit 72, the solenoid valve 27 being excited.

Description

[Detailed description of the invention] Regarding a control device.

In a vehicle automatic transmission using a fluid torque converter, as long as the shift position is set to a driving range such as D range, the engine can be operated without load (even if the engine is stopped at a certain temperature or temperature). When driving at low speeds, the force that attempts to drive the vehicle acts on the transmission output shaft considerably, causing a so-called creep phenomenon, which causes the engine load to increase relative to the idling speed, causing the idling speed to increase. Problems arise in that the power consumption range fluctuates widely, the power reduction distance becomes longer, or the amount of fuel consumed during no-load operation increases.

As a solution to the above-mentioned problems, as shown in Japanese Patent Publication No. 47-19962, when the brake is operated at low vehicle speed, the automatic transmission is automatically set to neutral (neutral). A device has been proposed in which settings can be made.

However, in the above-mentioned conventional neutral control device, when the brake is operated at low vehicle speed, the automatic transmission is immediately set to the neutral state, so if the brake is repeatedly applied and released within a short period of time, the neutral state There was a problem in that the drivability was impaired due to frequent switching between the two, causing hunting.

An object of the present invention is to provide a neutral control device for an automatic transmission for a vehicle, which eliminates the problems occurring in the conventional device described above and prevents unnecessary frequent switching between the neutral state and the driving range. This is the purpose.

The neutral control device for a vehicle automatic transmission of the present invention includes:
The automatic transmission is characterized by using a timer section to set the automatic transmission to the neutral state only when the vehicle is stopped for a certain period of time at low vehicle speeds (including when stopped).

By providing a timer section as described above, the automatic transmission will not shift to the neutral state even if the brake is applied and released repeatedly within a short period of time (and the occurrence of the above-mentioned crank) will be prevented. Prevented.

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

Figure 1 shows 6 positions (P) by manual operation.

R, N, D, 2. 1 shows a power transmission mechanism portion of an automatic transmission with three forward speeds and one reverse speed, in which shift position 1) is selected. In FIG. 1, a pump latch 2 of a fluid torque converter 1 is connected to an engine crankshaft 3 serving as an input shaft, and a hollow shaft 5 that rotates integrally with a turbine runner 4 of the torque converter 1 extends to the left in the figure. There is. A planetary gear mechanism 6 is arranged on the left side of the torque converter 1. The planetary gear mechanism 6 includes a front planetary gear mechanism 6A and a rear planetary gear mechanism 6B, both of which share a sun gear 7.

The hollow shaft 5 is connected to the front clutch 8 via the front clutch 8.
Connecting shell 9 that rotates integrally with the sun gear 7
The connecting shell 9 is fixed to or released from the case 11 by a brake band 10. The hollow shaft 5 is also connected to a front ring gear (internal gear) 13 of a front planetary gear mechanism 6A via a rear clutch 12.

A front binion gear 14 that meshes with the front ring gear l3 and the sun gear 7 is rotatably held by a front planet carrier l5, and an output gear 16 of an automatic transmission is provided on the outer periphery of the end of the front planet carrier l5. is installed.

The front planet carrier 15 is provided with a rear ring gear 17, and a rear pinion gear 18 that meshes with the rear ring gear 17 and the sun gear 7 is rotatably held by the rear planet carrier 19. This rear planet carrier 19 is fixed to or released from the case 11 by a low and reverse brake 20, and is connected to the case 11 via a one-way clutch 21.

In FIG. 1, 22 is a parking gear, 23 is a stator connected to the case 11 via a one-way clutch 24, and 25 is rotationally driven by a crankshaft l-3 via a shaft 26 disposed within the hollow shaft 5. This is an oil pump.

The power transmission mechanism with the above configuration includes a clutch 8゜12 and a brake band 1 which are operated by hydraulic pressure.
0 and the low and reverse brake 20, the gears are set to 1st speed, 2nd speed, etc. as appropriate, and the relationship between these is shown in FIG.

The following description will be made with reference to the clutches 8 and 12, the brake band 10, and the brake and reverse spray. In FIG. 3, reference numeral 29 is a pressure regulating valve that regulates the pressure of the pressure oil discharged from the oil pump 25 in the oil passage 3 to a predetermined pressure, and 31 and 32 are the output 7 and gear 1, respectively.
First and second governor valves are fixed to an output shaft (not shown) connected to 6 and generate hydraulic pressure (governor pressure) according to the vehicle speed, and 33 is a hydraulic pressure proportional to the throttle angle of the carburetor throttle valve. Throttle valve that generates (throttle pressure)
Reference numeral 34 denotes a manual valve having a spool 34a that is linked to a shift lever, and when the manual pulp 34 is positioned at each predetermined range position, the oil passage 3 whose pressure is regulated by the pressure regulating valve 29 is
A hydraulic pressure (line pressure) of 0 is applied to the spool 34- of the plurality of oil passages 35 to 39 connected to the manual pulp 34.
The oil is introduced into communication with the predetermined oil passage selected by a.

One oil passage 35 among the oil passages 35 to 39 is connected to the rear clutch 12 via a solenoid valve 27, which will be described in detail below.

The solenoid valve 27 has an outlet boat 27a to which the oil passage 35a on the manual valve 34 side of the oil passage 35 is connected, and an outlet boat 27b to which the oil passage 35b on the rear clutch 12 side of the oil passage 35 is connected. . The solenoid 2'7C is normally demagnetized, and in that case, the spool 27d is urged by the return spring 27e and moves to the right to the position shown in the figure, thereby communicating the oil passage 35a and the oil passage 35b. The manual pulp 34 includes 1.2. It is configured to discharge pressure oil to the oil passage 35 when in the D range, and therefore, if the oil passage 35a and the oil passage 35b are communicated as described above, the rear clutch 12 is normally operated from 1st gear onwards. The connected state is set through the third speed state.

Further, 40 is a 1-2 shift valve, and the 1-2 shift valve 40 is Suge-/L/4. Oa and the spool 40
A spring 40c is compressed into a spring chamber 40b at one end of the spool 40a, and the first governor valve 3 is mounted at the other end of the spool 40a.
A single governor pressure is applied through the oil passage 41, and the force relationship between the governor pressure and the biasing force of the spring 40C causes the spool 40a to move left and right.

Further, a manual pulp 34 is connected to the 1-2 shift valve 40 via an oil passage 35, and an oil passage 42
A second lock valve 49, which will be described later, is connected to the engagement side 4.3a of a servo piston (hydraulic actuator that operates the brake band 1o) 43 of the brake band 1o via an oil passage 50. ,
Spool 40 moved to the right by the urging force of spring 40c
a closes the oil passage 35 to the manual pulp 34, and at the same time closes the brake band l.

Open the oil passage 42 to the drain and remove the brake band 1.
0 is not engaged, while in the second forward speed, the spool 40a moved to the left by the governor pressure connects and communicates the oil passage 42 to the brake band 1° with the oil passage 35 to the manual valve 34 to introduce line pressure. By doing so,
It is configured to fasten the brake band 10.

Further, the low and reverse brake 20 is connected to the 122 shift valve 40 via an oil line 44, and a manual pulp 34 is connected via an oil line 36. At times, while the spool 40a is moving to the right by the force of the spring 40c, the spool 40a connects and communicates the oil passage 44 to the low and reverse brake 20 with the oil passage 36 to the manual valve 34. By introducing line pressure, low and reverse brake 20
It is configured to conclude. Further, the 1-2 shift valve 40 has an oil passage 45 communicating with the spring chamber 40b, and when the manual pulp 34 is in the "1" range position,
Spool 4 moved to the right by the biasing force of spring 40c
By connecting and communicating the oil passage 36 to the manual pulp 34 with the oil passage 45 through 0a, the spring chamber 40
1) Line pressure is introduced to shift the shift point from the first gear to the second gear at a high vehicle speed.

Furthermore, 46 is a 2-3 shift valve, and the 2-3 shift valve 46 has a first spool/I6a and a second spool 46.
b, and a spring 46d compressed into a spring chamber 46c formed between the two spools 46a, 46b, and the end surface of the first spool 46a opposite to the spring chamber 4. While the governor pressure of the first governor valve 31 acts, the throttle pressure of the throttle valve 33 acts on the end face of the second governor 461) opposite to the spring chamber 46c via the oil passage 47, and the throttle pressure and The first and second spools 46a and 46b are moved left and right by the force relationship between the urging force of the spring 46d and the governor pressure. Further, the 2-3 shift valve 46 is connected to the front clutch 8 and the release side 43b of the servo piston 43 of the brake band 1o through an oil path 48, and the manual valve 34 is connected to the 2-3 shift valve 46 through an oil path 37 and an oil path 38. The oil passage to one manual pulp 34 is connected to the first spool 46a, which moves to the right under the force of the throttle pressure and the urging force of the spring 46d during the first forward speed and the second forward speed. 37 and connect the oil passage 48 to the front clutch 8 and the brake band 10 to the oil passage 38 to the other manual valve 34 and open it to the drain, thereby releasing the front clutch 8 and at the same time opening the brake band. The hand 10 is engaged or released depending on the presence or absence of hydraulic pressure acting on the engagement side 43a of the servo piston 43. On the other hand, in the third forward speed, the first spool 46a is biased by the governor pressure and moves to the left.
Conversely, the oil passage 38 to the other manual valve 34 is closed, and the oil passage 48 to the front clutch 8 and the brake cylinder 10 is connected to the oil passage 37 to the one manual valve 34, thereby opening the line. By introducing pressure, the front clutch 8 is engaged and the brake band 1o is simultaneously released.

Further, reference numeral 49 denotes a second lock valve for starting at the second forward speed when the manual valve 34 is in the "2" range position, and the second lock valve 49 is connected to the spool 49a and the bottom of the spool 4-9a. and a spring 49b that urges the end face upward. The second lock valve 4
The spring chambers 4.9C of 9 are connected to the manual valve 34 through the oil passage 37, and the oil chambers 4.9D opposite to the spring chambers 4 and 9c shown in ± are connected to the manual pulp 34 through the oil passage 39, respectively. Further, the engagement side 43a of the servo piston 43 of the brake band 1o is connected to the second lock valve 49 via an oil passage 50, and the 1-2 shift valve 40 is connected via an oil passage 42, respectively. Spring 49 at all times
The oil passage 50 of the brake bunt 10 is connected to the 1-2 shift valve 4 by the spool 49a located above and biased by the spool 49a.
When the manual pulp 34 is switched to the "2" range position,
By opening the oil passage 37 communicating with the spring chamber 49C- to a drain and moving the spool 49a downward while resisting the biasing force of the spring 49b with the line pressure acting on the oil chamber 49d, the brake band The brake band 10 is forcibly fastened by communicating the oil passage 50 to the brake band 10 with the oil chamber 49d and applying line pressure.

Here, when the above-mentioned automatic transmission is in the D range and the vehicle speed is low (
1st gear), this D range can be changed manually to N.
In order to set the vehicle to neutral without switching to the neutral range, the hydraulic pressure supply to the rear clutch 12 may be cut to keep the rear clutch 12 in the disengaged state. For this reason, a solenoid valve 27 as an electromagnetic means as shown in FIG. 3 is interposed in the hydraulic circuit to the rear clutch 12. That is, when the solenoid 27C is energized to set the neutral state, the spool 27d
is pushed to the left in the figure by the rod 27f, and the outlet port 27b is disconnected from the inlet port 27a and communicated with the drain port 27g. Therefore, the rear clutch]
The line pressure supply to 2 is cut off, the rear clutch 12 is disengaged, and the automatic transmission is set to a neutral state.

FIG. 4 shows a controller that controls the operation of the solenoid valve 27. The controller is provided with four sensors 58, 59, 60, and 61 to detect a stopping operation in which a device for stopping the vehicle is operated at low vehicle speeds. Among these four sensors, sensor 5
8 detects the vehicle speed and selects a predetermined low speed (for example, 8 to 1.5 m).
/h) A vehicle speed detection sensor that turns ON in the following cases and is configured to detect the output of a speedometer oscillator or a governor incorporated in the hydraulic circuit of an automatic transmission. Sensors 59 to 61 are sensors for detecting that a stop operation is being performed, and sensor 59 is an accelerator fully closed detection sensor that turns on when the accelerator pedal 62 is released and the accelerator is fully closed. The sensor 60 is
The foot brake operation detection sensor turns on when the foot brake 63 is depressed, and the sensor 61 is a parking brake operation detection sensor that turns on when the parking brake lever 64 is applied.

The outputs of the sensors 58 and 59 are fed to the amplifier 65 or 6.
6, the output of the sensor 60.
Alternatively, it is input to the two-man OR gate 70 via the AND gate 69, and the output of the OR gate 70 is the AND gate 67.
is input. Therefore, the AND gate 67 determines that the vehicle speed is below a predetermined low speed and the accelerator 62 is fully closed.
Moreover, the output is only generated when at least one of the foot brake 63 and the parking brake lever 64 is operated.

The output from the AND gate 67 is directly input to a two-man power AND gate 71, while a timer circuit 72 consisting of a one-shot multivibrator as a timer section
is also input, and the output of this timer circuit 72 is
The signal is input to the D gate 71. Therefore, the AND gate 71 outputs the output from the AND gate 67 to the timer circuit 72.
It emits an output only when it lasts for a predetermined period of time. The output from this AND gate 71 is input to the base of the switching transistor 730.

The switching transistor 73 has a switching function to control the energization of the solenoid 27a of the solenoid valve 27 described above, and energizes the solenoid 27a when the output from the AND gate 71 is input. When the solenoid 27a is energized and energized, the rear clutch 12 is disengaged as described above, and the automatic transmission automatically enters the neutral state.

Both AND gates 67 and 71 mentioned above and the timer circuit 72
The relationship between ρ and ρ is shown in FIGS. 5(a), (b), and (c) and FIG. That is, AND gate 7
1 continues for a predetermined time T determined by the timer circuit 72, it is output from the AND gate 71 for the first time.
Even if an output with a duration shorter than 1 is repeatedly issued, the timer circuit 72 does not output any output, so the output from the AND gate 71 is suppressed. Of course, if any one of the following three conditions is satisfied: both brakes 63 and 64 are released, the accelerator 62 is depressed, or the vehicle speed exceeds a predetermined speed, the AND gate is activated. There is no output from 67, the rear clutch 12 is connected, and the automatic transmission automatically returns to the driving range.

In the above embodiment, the controller for controlling the valve 27 is constituted by a hardware circuit including a logic circuit, but it is of course possible to constitute this controller by a microcomputer.

As described in detail below, the neutral control device for an automatic transmission for a vehicle of the present invention includes a timer unit and sets the automatic transmission to the neutral state only when a stopping operation continues for a certain period of time at a low vehicle speed. Therefore, the automatic transmission does not shift to the neutral state even if the foot brake is operated repeatedly within a short period of time, eg, by repeatedly pressing the foot brake in a short period of time, the automatic transmission does not shift to the neutral state. Unnecessary and frequent switching between neutral and driving range can be prevented, ensuring good drivability.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the power transmission mechanism portion of an automatic transmission to which the present invention is applied, and FIG. 2 shows the relationship between the operating state of each component of the automatic transmission shown in FIG. 1 and the shift position. 3 is a sectional view showing an example of a solenoid valve that sets an automatic transmission to a neutral state, FIG. 4 is a circuit diagram showing an example of a controller that controls the solenoid valve, and FIG. ), (/→ and FIG. 6 (A), (B), (/→ are graphs explaining the operation of the solenoid valve controller. 1... Torque converter 12... Rear clutch 27... - Solenoid valve 58...Vehicle speed detection sensor 59...Accelerator fully closed detection sensor 60...Foot brake operation detection sensor 61...Parking brake operation detection sensor 67.71...AN
D gate 70...OR gate 72...timer circuit

Claims (1)

[Claims] In an automatic transmission comprising a liquid converter, a planetary gear mechanism, and a plurality of friction engagement members that switch a power transmission path of the planetary gear mechanism, a friction engagement that connects and disconnects transmission of the output of the fluid converter 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, a vehicle speed sensor for detecting that the vehicle speed is below a set speed, and It consists of a stop operation detection sensor that detects the operation of the equipment to be stopped, a determination unit that determines the conditions under which the outputs of these sensors are issued together, and a timer unit that detects that the output of this determination unit continues for a certain period of time. A neutral control device for an automatic transmission for a vehicle, comprising: a controller that generates an output signal for operating the electromagnetic means to bring the automatic transmission into a neutral state according to an output from the controller.