JPH0562095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a braking force retention control device for vehicles and the like.

(Prior art) When starting a vehicle from a stopped position on an uphill road, conventionally the driver operates the handbrake with one hand to apply braking force to the vehicle to keep it stationary, and then depresses the accelerator pedal with his foot. The operation involved gradually releasing the handbrake while gradually engaging the clutch. Since complex operations are required while maintaining the connection between the brake and accelerator, if you are not used to the operations, you may experience the inconvenience of stalling or the vehicle moving backwards, and it may take some time until you can start smoothly. The disadvantage was that it required considerable skill.

(Problems to be solved by the invention) In order to solve the above problems, for example,
An electronic automatic transmission device with a braking force holding device as disclosed in Japanese Patent No. 11719 has been proposed. This device, in vehicles equipped with a synchronized mesh automatic transmission with a friction clutch controlled by an electronic control device, centrally controls signals from various detection devices in the vehicle and transmits them to the fluid actuator for the clutch. The system is designed to hold the braking force until the clutch engages, thereby appropriately controlling the holding of the braking force and making it possible to start up on an uphill slope smoothly without requiring any skill. ing. However, in the above braking force holding device, the brake check valve is always released at a fixed clutch engagement position, so the release of the brake may vary depending on the loading condition of the vehicle, that is, whether it is loaded or empty. There were drawbacks such as the vehicle moving backwards too quickly, or the brakes being released too late causing the vehicle to start suddenly.

The present invention has been made in view of the above points, and
Depending on the empty load state reported by the driver or the empty load state detected by means for detecting the loaded state,
It is an object of the present invention to provide a braking force retention control device that changes the clutch connection position for releasing the braking force, thereby facilitating smooth starting at all times.

(Means for Solving the Problems) According to the present invention, when the brake pedal is depressed while the vehicle is stopped, the engine is rotating with the clutch off, and the gear position is other than neutral, the brake hydraulic pressure is reduced. In the braking force retention control device in which the braking force is maintained by the action of the check valve 3a, there is a loading state detection means for detecting the loading state of the vehicle, and as the weight of the loaded vehicle increases, the same accelerator pedal depression amount is applied. The map includes a map showing the amount of clutch engagement corresponding to the amount of depression of the accelerator pedal, which increases the amount of engagement of the clutch. It is characterized by comprising a braking force release means that releases the braking force by circulating brake oil regardless of the presence of the check valve when the engaged state is equal to or higher than the engaged state taking into account the load capacity determined by the map. A braking force retention control device is provided.

(Function) The present invention is a braking force holding control device that temporarily holds the braking force when a stopped vehicle depresses the brake in order to start. In addition to signals related to the vehicle's loading status, the loading status of the vehicle is also read, and as the accelerator pedal is depressed, the optimal clutch position is selected. Since the system is automatically released in this state, it is possible to prevent the vehicle from backing up or suddenly starting when starting on an uphill road.

(Embodiment) Fig. 1 is a configuration diagram of an embodiment of the present invention, in which A is a brake actuation device (braking device), B is a clutch actuation device, 1 is a brake pedal, 2 is a master cylinder, 2a 2 is an oil pressure sensor, 22 is a vehicle loading state detection means, 3 is an electromagnetic check valve device for braking, 3
a is a check valve, 3b is a switching valve, 4 is a wheel cylinder, and 5 is a solenoid, which together form the braking device A.
It consists of 7 is a fluid pressure source, 8 is a tank,
9 is a solenoid valve for a clutch actuator, 10 is a clutch actuator, and 11 is a friction clutch, which constitute a clutch actuating device B. 12 is a transmission, 12a is a transmission output shaft, and the output from the output shaft is transmitted to wheels 15 via differential gears 14. Reference numeral 19 denotes an engine, which controls the opening and closing of a throttle valve 19b by pressing an accelerator pedal 20 to control the engine speed. Reference numeral 6 is an electronic control device that outputs an output signal from a vehicle speed sensor 16 provided on the output shaft side of the transmission, an output signal from the shift actuator 13, an output signal from the select position switch 18 of the select lever 17, and an output signal from the engine 19. An output signal from an engine rotation sensor 19a provided in the engine rotation sensor 19a, an output signal from an accelerator pedal sensor 20a provided in the accelerator pedal 20, an output signal from the brake pedal switch 1a provided in the brake pedal 1, and an output signal from the brake pedal switch 1a provided in the parking brake 30. The output signals from various sensors including the output signal from the parking brake switch 31, the output signal from the oil pressure sensor 2a, and the output signal from the loading state detection means 22, and the output signal from the clutch stroke sensor 10a are input, and the output signals from the clutch stroke sensor 10a are input. By processing the signals, it outputs control signals and controls the driving of the vehicle. Also, when the vehicle is stopped, the clutch is off, the engine is running, and the brake pedal is depressed while the gear is in a position other than neutral.
Brake oil pressure is maintained by the check valve 3a to ensure braking force, but when the accelerator pedal is depressed to start the vehicle, the brake is automatically released in an optimal state depending on the loading condition of the vehicle. It is configured as follows.

The vehicle loading state detection means 22 may report the loading amount set by a manual notification switch to the electronic control unit 6, or may be a sensor using a piezoelectric element such as crystal or ceramic, or a spring type sensor. Alternatively, a strain meter type sensor may be used.

FIG. 2 is a configuration diagram of another embodiment of the present invention applied to a large vehicle using pneumatic control. Components that are the same as those in FIG. The following points are different in the configuration. That is, instead of the master cylinder 2 in the embodiment shown in FIG. 1, a depression amount detector 1b, an air tank 40, and an air master 41 are provided. , an air pressure control path reaching the wheel cylinder 4 via the air master 41 is provided.

Fig. 3 is a flowchart showing the control steps, and Fig. 4 shows the position of the clutch at which the brake is released (hereinafter referred to as the "released clutch position") CLTi.
This map shows changes in the amount of clutch engagement relative to the amount of accelerator pedal depression depending on whether the vehicle is loaded or empty. That is, when the vehicle is loaded, the amount of clutch engagement relative to the amount of depression of the accelerator pedal is greater than when the vehicle is empty.

The control steps of the present invention will be explained based on the flowchart of FIG. 3 and FIG. 16. The current gear is read from the select position switch 18, the parking brake switch 31, the accelerator pedal sensor 20a, and the loading state detection means (declaration switch or sensor) 22 (step a to step e'), and then the current gear is transmitted to the transmission actuator 13. (step f).

Next, the select lever 17 is set to neutral (=
0) (step g), whether the parking brake 30 is in operation (step h), and whether the vehicle speed is equal to or higher than the set value SPD1 (step i). When these are YES, the device does not operate and the braking force of the braking device is released (step n).

Select lever 17 is not neutral,
When the parking brake 30 is released and the vehicle speed is less than the set value SPD1, a map is selected for the release clutch position of the braking device according to the current gear, vehicle speed, and loading status (step j), and from this map the accelerator pedal is released. The release clutch position is determined using the amount of depression as an argument (step k).

Next, it is determined whether the position CLT of the friction clutch 11 is closer to the engagement side than the release clutch position CLTi shown in FIG. 4 described above (step 1). If the release clutch is not closer to the release clutch position CLTi, the braking device A is maintained in the braking force holding state (step m). On the other hand, when the engagement position CLT of the clutch 11 is closer to the disengaged clutch position CLTi, or when the select lever 17 is in neutral at step g, or when the parking brake 30 is operating at step h, or when the vehicle speed is set When the value SPD is 1 or more, the electromagnetic check valve device 3 for braking
The solenoid 5 is operated to allow brake oil to flow regardless of the presence of the check valve 3a. In either case, the braking force is released (step n). Further, the engagement operation of the friction clutch 11 is automatically performed in response to a predetermined signal from the electronic control device.

(Effects of the Invention) As described above, the electronic control device of the present invention first reads signals related to brakes, accelerators, etc., especially signals detecting the vehicle loading state, and then operates the select lever, parking brake, etc. Since the optimum clutch position is selected and the brake is released according to the state of the vehicle speed, it is possible to sufficiently prevent the vehicle from retreating or suddenly starting even when starting on an uphill road.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a configuration diagram showing another embodiment, Figure 3 is a flowchart for explaining the braking force holding operation, and Figure 4 is a diagram showing the difference in the release clutch position depending on the vehicle loading state (empty or loaded). This is an example of a map shown. 6...Electronic control device, 9...Solenoid valve for clutch actuator, 10...Clutch actuator, 2
2...Vehicle loading state detection means.

Claims (1)

[Claims] 1 When the vehicle is stopped, the engine is rotating with the clutch off, and the brake pedal is depressed while the gear position is in a position other than neutral, the brake oil pressure is maintained by the action of the check valve 3a, ensuring braking force. The braking force retention control device includes a loading state detection means for detecting the loaded state of the vehicle, and an accelerator pedal depression amount in which the greater the weight of the loaded vehicle, the greater the clutch engagement amount corresponding to the same accelerator pedal depression amount. The clutch has a map indicating the amount of clutch engagement to be performed, and when the accelerator pedal is depressed from the braking force securing state, the clutch is in an engaged state corresponding to the amount of depression, taking into account the load amount determined by the map. A braking force retention control device characterized in that it comprises a braking force release means for releasing the braking force by circulating brake oil regardless of the presence of the check valve.