JPH02154858A - Automatic transmission control device for automobile - Google Patents

Abstract

PURPOSE:To apply a brake together with the brake force by an engine bake by operating a preset shift valve and performing the down shift of an automatic transmission when the brake signal value is larger than the initial preset value. CONSTITUTION:When a foot bake is depressed and a foot brake device 2 is operated, the brake signal 10 corresponding to the brake operation is compared with the initial preset value 17 by a comparing means 12. When the brake signal is larger and a quick brake is judged, an actuator 26 is operated. A preset shift valve 37 is operated, an automatic transmission 36a is forcibly down-shifted to the preset shift stage, and an engine brake is generated. The braking performance and safety of an automobile can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to an automatic transmission control device for an automobile.
More specifically, the present invention relates to an automatic transmission control device that downshifts the transmission to a predetermined gear position in response to the sudden braking operation using the foot brake to generate engine jerk.

(Old Conventional Technology) In the past, downshift control of automatic transmissions was performed based on the balance between throttle opening and vehicle speed, and was performed regardless of the speed and speed of brake operation.
When a car is running at high speed and the brake pedal is pressed to apply a sudden brake, all the energy from the car's running must be absorbed by the foot brake system. There was no room to operate the lever, so engine braking could not be used in the event of sudden braking.

(C) Problems to be Solved by the Invention Conventional vehicles equipped with automatic transmissions used only the foot brake to perform braking action during sudden braking, as described above. There was a problem that the brake capacity was lower than that of a car, and that it required a large brake capacity.

In addition, vehicles equipped with automatic transmissions in particular have a larger inertial mass in the drive system and must absorb more energy than vehicles equipped with manual transmissions, so with the same brake capacity as a vehicle equipped with manual transmissions, There is a problem in that a great force is required to press the brake pedal, and the life of the brake pedal device is shortened.

Therefore, the present invention is designed to generate engine braking when sudden braking is applied to a running vehicle.
- It is an object of the present invention to provide an automatic transmission control device for an automobile, which brakes the automobile by using the braking force from an engine brake in combination with the braking force from a brake device.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIGS. Multiple shift valves for (
37) automatic transmissions (36a), (36b) having
In an automobile having a foot brake device (2) for braking the automobile, the brake signals (10) and (41) corresponding to the operating amount of the foot brake device (2) are set to preset initial setting values (17). ), (52), and the brake signal values (10), (41) are compared with the initial setting values (17), (52).
), shift control means (26), (53) for operating a predetermined shift valve (37) to downshift the automatic transmissions (36a), (36b);
It is characterized by comprising the following.

(e) Effect Based on the J2 configuration, when the foot pedal of the brake device (2) is depressed and the brake is activated, the brake signals (10) and (41) corresponding to this brake activation are generated.
occurs. Comparing these brake signals (10) and (41) with preset initial setting values (17) and (52),
Brake signal (to), (41) is the initial setting value (17)
, (52) and the braking is sudden, the downshift control means (26) or (53) operates to select a predetermined shift valve (3) from among the plurality of shift valves.
7) Operate. By operating this shift valve (37), the automatic transmission (36a) (36b) is forcibly shifted to a predetermined gear position and engine braking is generated. Braking is performed in cooperation with the engine brake.

Note that the symbols in parentheses above are shown for reference and do not limit the configuration in any way.) Example The first example of the present invention will be described below based on FIGS. 1 and 2. I will explain.

In this embodiment, a hydraulically controlled automatic transmission 36a is used. A foot brake device W2 is connected to the automatic transmission control device 1 as described later. As shown in FIG. 2, this foot brake device 2 has a brake master cylinder 5 on the brake pedal 3 side, and a wheel side brake cylinder 7 connected to the cylinder 5 through a pipe 6. Brake master cylinder 5
When the inner piston 5a moves in the direction of arrow 9 in response to the brake pedal force of the foot brake 3 and generates brake working pressure 10, the piston 7a of the wheel side brake cylinder 7 moves in the direction of arrow 11 due to this brake working pressure 10. This applies brakes to wheels (not shown). That is, the brake operating pressure 10 is used as a brake signal when the foot brake device 2 performs a brake action.

One end of the switching valve 12 is connected to the pipe 6 via a pipe 13, and the other end is connected to the brake oil reservoir tank 15. Due to the elasticity of the provided compression spring 15, it is biased in a direction opposing the brake operating pressure 10. The biasing force of the compression spring 15 against the piston 12a can be adjusted in advance to a predetermined magnitude by operating an adjustment handle (path shown) provided outside the switching valve 12.

A discharge port 12b is provided at a suitable location in the middle of the switching valve 12, and this discharge port 12b is connected to one end of a pipe 16. When stepping on the foot brake 3 is a normal brake operation and the brake operating pressure 10 is the normal brake operating pressure, the piston 12a of the switching valve 12
is located at the position indicated by the solid line in FIG. In addition, if the brake operating pressure of 1° is the high operating pressure during sudden braking,
The piston 12a is pressed by the brake operating pressure 10 and moves to the operating position shown by the chain line 12A in FIG. 2, opening the discharge port 12b. piston 12
a is pressed by the brake operating pressure 10 and the discharge port 12b
When the switching valve 12 is opened, the value of the biasing force of the compression spring 15 acting on the piston 12a immediately before the opening is set as the initial setting value 17 (see FIG. 1) of the switching valve 12. Then, the brake operating pressure 10 is compared with the predetermined initial setting 17 of the switching valve 12, and if it is larger than the initial setting 17, that is, if the braking is more than a certain level, the brake operation pressure 10 is determined as described above. The discharge port 12b opens and outputs the signal pressure lea. The switching valve 12 serves as a comparing means (see FIG. 1) for comparing the brake operating pressure generated when the foot brake device 2 is activated with a preset initial setting value 17.

The throttle assembly 19 includes upper and lower compression springs 20,
21, and a downshift plug 26 that faces the throttle valve 23 via the compression spring 21 and is loosely inserted into the sleeve 25. A trochanter 27 provided at the lower end of the downshift plug 26 is in pressure contact with the circumferential surface of a throttle cam (not shown), and this throttle cam rotates in response to the degree of depression of the accelerator pedal to shift the downshift. While the shift plug 26 is moved up and down, the throttle valve 23 is also moved up and down via the compression spring 21.

Line pressure 29 supplied from a primary regulator valve (not shown) to the throttle valve 23 is connected to the boat 29.
The throttle pressure 30 that is supplied to a and discharged from the boat 3Oa is a shift valve in the direction of arrow 30b, a secondary regulator valve in the direction of 30c,
Each acts on the primary regulator valve in the 30d direction. The governor modulator pressure 28 and the throttle pressure 30 act on the cutback valve 31 to generate cutback pressure 32, and the cutback pressure 32 acts on the throttle valve 23 to increase the throttle pressure. By adjusting the pressure at 30, the two line pressures are adjusted.

Detent pressure 33a from a detent regulator valve (path shown) acts on the downshift plug 26. Furthermore, a stepped portion 26c formed by the large diameter portion 26a and the small diameter portion 26b of the downshift plug 26 is provided with the pipe 1.
The signal pressure 16Q from 6 acts at a predetermined time to be described later to bias the town shift plug 26 in the direction of arrow 35. Therefore, the signal pressure 16a from the pipe 16
The downshift plug 26 operated by the downshift plug 26 constitutes an actuator. When the downshift plug 26 moves in the direction of an arrow 35 due to the action of a signal pressure 16a to be described later, a detent pressure 33b that functions as a town shift pressure is generated, and this detent pressure 33b is applied to the automatic transmission 36a.
It acts on a predetermined shift valve 37 among a plurality of shift valves included in the hydraulic control device (see FIG. 1). By operating this predetermined shift valve 37, the automatic transmission 36
The transmission device a is forcibly downshifted to a predetermined gear position. The downshift plug (26) is used as shift control means.

Next, the operation of the above-mentioned device will be explained. The driver presses the brake pedal 3 of the foot brake device 2 while the car is running.
When you step on the brake, the brake operating pressure 1 corresponds to the brake pedal force.
0 occurs and the car is braked. When this brake operating pressure 10 is the normal brake pressure, the piston 12a of the switching valve 12 is at the solid line position in FIG.
The discharge port 12b is in a closed state. However, if the brake pedal force is large and the brake operating pressure 10 is larger than the preset value set in the compression spring 15, the piston 12b moves to the operating position shown by the chain line 12A and opens the discharge port 12b. It is opened and a part of the brake operating pressure 10 is discharged to the pipe 16 as a signal pressure (brake signal value) 16a.

The signal pressure 16a from the limb tube 16 is applied to the downshift plug 26.
The downshift plug 26 is moved in the direction of the arrow 35 by acting on the stepped portion 26c, and the detent pressure 33a acting from the detent regulator valve is conducted to the discharge side boat, thereby increasing the detent pressure (downshift signal) 33b. occurs. By this detent pressure 33b acting on predetermined shift 1 to valve 37, the transmission device of the automatic transmission 36a is forcibly downshifted to a predetermined gear position, and the engine ( (not shown), engine braking occurs. As a result, a running car receives a braking action from the foot brake device 2 when the brake pedal 3 is depressed, and a braking action from the above-mentioned engine brake, so that the car can stop quickly in an emergency. At the same time, the burden on the brake braking device 2 is reduced and its lifespan is extended.

3 and 4 show a second embodiment of the invention.

In this embodiment, an electronically controlled automatic transmission 36b
is used. The automatic transmission control device 1 shown in the schematic diagram of FIG. 3 includes a brake detection section 40 and a downshift signal 43 that outputs a downshift signal 43 when a brake signal 41 detected by the brake detection section 40 is determined to be a sudden brake. It has an electronic control device 45 that outputs an output, and a predetermined shift solenoid 46 and a predetermined shift valve 37 that are operated in response to the downshift signal 43. Further, the electronic control section 45
A comparison circuit, which will be described later, compares a preset initial setting value and the brake signal 41, and the brake signal 4
If 1 is large, it is determined that a sudden brake has been applied to the vehicle, and the control section 42 outputs a predetermined downshift signal 43.

As a means for detecting the braking action by the brake detecting section 40, for example, a foot brake device is used! ! (Brake operating pressure 1° generated during brake operation in step 2 (see Figure 2)
Pressure sensor 47a or pressure switch 47b that detects
A speed sensor 49 that detects vehicle speed, a travel sensor 50a or potentiometer 50b that detects brake pedal travel, etc. are used as appropriate.

Foot pedal 3 of foot brake device 2 (see Figure 2)
The brake signal 41 generated by stepping on the foot brake device 2 is the brake operating pressure 4 of the foot brake device 2 detected by the pressure sensor 47a or the pressure switch 47b.
1a, vehicle deceleration (negative acceleration) 41b measured by the detection signal of the speed sensor 49, and pedal travel 41c or pedal depression speed (acceleration) 41d measured by the detection signals of the travel sensor 50a and potentiometer 50b, etc. There is. After one of these is converted into an electrical signal, it is output to a comparator circuit 51 and compared with a preset initial setting value 52, as shown in FIG.

The brake signal 41 compared in the comparison circuit 51 is
When the initial setting value 52 is exceeded, it is determined that the foot brake device 2 has been suddenly braked, and a signal is output to the downshift control device 53. Downshift control device 5
3 determines the gear stage of the automatic transmission 36b that will prevent the engine from over-balancing in accordance with the vehicle speed when the sudden brake is operated, and outputs a predetermined downshift signal 43.

A predetermined shift solenoid 46 of the automatic transmission 36b is activated by the downshift signal 43 described above.

It acts on the predetermined shift valve 37 to forcibly downshift the transmission device of the automatic transmission 36b to a predetermined gear position. Due to this downshift action, engine braking is generated in the engine connected to the automatic transmission 36b, and the running vehicle is affected by the cooperation between the braking force from the foot brake device 2 described above and the braking force from the engine brake. It is braked by the action.

(g) As described in detail, according to the present invention, the brake signal (1) generated when the foot brake device (2) brakes is operated.
0) is larger than the preset initial setting value (16), it is determined that the brake operation is a sudden brake, and a predetermined shift valve (37) is activated to change the transmission of the automatic transmission (36a). Since the vehicle is downshifted to a predetermined gear position and engine braking is generated, the running automobile can also utilize the braking force from the engine brake in addition to the braking force from the foot brake device (2). As a result, it is possible to improve the braking effectiveness of an automobile equipped with an automatic transmission whose drive system has a larger inertial mass than a manual transmission, and to reduce the capacity of the foot brake device (2). Particularly in automobiles equipped with anti-lock brakes, the wheels do not lock, so if the present invention is applied to the above-mentioned automobiles, the effects will be great. In addition, in the event of an emergency for a car traveling at high speed, a portion of the energy that the car has when suddenly stepping on the brakes is absorbed by the engine brake, which improves the braking performance and safety of the car, and improves the foot brake system. It is possible to extend the life of the

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an automatic transmission control device for an automobile showing a first embodiment of the present invention, and FIG. 2 is a partially cutaway front view showing the foot brake device and downshift plug of the device in FIG. 3 and 3 are schematic configuration diagrams of an automatic transmission control device for an automobile showing a second embodiment of the present invention, and FIG. 4 is a block diagram as well. 1... Automatic transmission control device 2... Foot brake device 3... Brake pedal 1°...
・Brake signal (brake operating pressure) 12... Comparison means (switching valve) 15... Compression spring 17
... Initial setting value (biasing force at a predetermined length of compression spring 15) 26 ... Shift control means (downshift plug) 30b ... Downshift signal (detent pressure) 36a ... Hydraulic-controlled automatic transmission 36b
...Electronically controlled automatic transmission 37...Predetermined shift valve 40...Brake detection section 41.
... Brake signal 42 ... Control section 43.
...Downshift signal 45...Electronic control device 4
6...Shift solenoid 51...Comparison circuit
52...Initial setting value, 53...Downshift control device

Claims (1)

[Scope of Claims] 1. An automobile having an automatic transmission connected to an automobile engine and having a plurality of shift valves for changing gears, and a foot brake device for controlling the automobile, comprising: a comparison means for comparing a brake signal corresponding to an actuation amount with a preset initial setting value; and when the brake signal value is larger than the initial setting value, operating a predetermined shift valve to downshift the automatic transmission. An automatic transmission control device for an automobile, comprising: shift control means for performing the following steps. 2. The comparing means is a switching valve that is switched by the brake operating pressure and a spring opposing the operating pressure, and the shift control means is a hydraulic pressure that operates the predetermined shift valve using hydraulic pressure from the switching valve. The automatic transmission control device for an automobile according to claim 1, wherein the automatic transmission control device is a downshift plug that generates a downshift plug. 3. The comparison means is a comparison circuit that compares the brake signal value with the initial setting value and outputs an electric signal when the brake signal value is large; The automatic transmission control device for an automobile according to claim 1, wherein the automatic transmission control device for an automobile is a shift control circuit that selects an optimum gear position based on an input signal and operates a predetermined shift valve.