JPH03121960A - Braking force holding device - Google Patents

Abstract

PURPOSE:To detect a braking force releasing point automatically with accuracy by setting a point, obtained by adding the correction value corresponding to the clutch connecting speed to a clutch stroke at the time of an input shaft starting its rotation by clutch connection with a gear in the neutral position, as the braking force releasing point for learning. CONSTITUTION:A control unit 14, upon detecting the output of a neutral switch 9 turned on at the time of detecting gear-neutral, receives, from a clutch stroke sensor 3, the input of a clutch stroke at the time of the input shaft of a transmission (T/M) 10 starting its rotation by clutch connection. A point obtained by adding the correction quantity corresponding to the clutch connecting speed to this clutch stroke is set as a braking force releasing point for learning. In other words, the clutch stroke quantity for transmitting sufficient torque by a clutch is changed according to the clutch connecting speed, and the necessity to correct this stroke quantity from the rotation starting of the input shaft to the cutoff side is increased as the clutch connecting speed becomes larger.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a braking force retention device. This invention relates to a device for smoothly and safely releasing the braking force of a vehicle. [Conventional technology] When starting a vehicle stopped on a road, in conventional vehicles, the driver uses the parking brake (handbrake) with one hand to apply braking force to the vehicle and keep it in a stopped state while pressing the clutch. gradually connect them, and at the same time press the accelerator pedal. During this time, the parking brake is gradually loosened. However, since such complicated operations are required while coordinating the brake and accelerator, skill is required to perform a smooth start111, which may result in so-called engine stalling or backward movement of the vehicle. Therefore, in Japanese Patent Application No. 58-117483 (Japanese Unexamined Patent Publication No. 11719-1983), the present applicant proposed an electromagnetic check valve for braking between a mask cylinder and a wheel cylinder that cooperates with a brake pedal and an actuator. In order to make this electromagnetic reverse 11-valve smoothly start from a stopped state on the boarding road, the accelerator pedal sensor, craftist [1-x sensor, Bonjin times, etc.]
, G1.・-kipetalus inch, gear A2 ij'lia
Output signals from the switch, select position switch, and vehicle speed sensor are input to the electronic control unit (CPU). Based on these input signals, the electronic control unit determines: ■ The gear select position is not neutral; ■ The vehicle speed is "0"; ■ The end of gear shifting; ■ The idle state of the engine; ■ The depression of the foot brake; ■ The release of the accelerator. and ■The clutch has a retention amount less than the half-clutch state (
clutch disengagement), and only when all of these conditions (1) to (2) are satisfied, the electromagnetic check valve is energized to maintain the braking force at the wheel cylinder. In addition, the braking force of the wheel cylinder cylinder is released when the engagement amount becomes larger than the half-clutch state (clutch engagement), or when the gear is in the neutral position, or when the [phase] vehicles are in the neutral position. This is done by deenergizing the electromagnetic check valve when the electronic control unit determines that the accelerator pedal is being depressed when the vehicle speed is higher than the set speed. However, with this braking force holding device, due to wear of the clutch driven plate, changes over time, and variations during assembly, the braking force may be released too quickly at the time of starting, causing the vehicle to back up on the uphill road. Or it's too slow and the brakes drag. Therefore, in Japanese Patent Application No. 62-94042 (Japanese Unexamined Patent Publication No. 63-25824), the present applicant provided a variable resistor as a clutch connection determination adjustment element to the above-mentioned braking force holding device, and set the setting by this variable resistor. The electronic control device compares the value with the actual clutch stroke, and only when the clutch plate returns to the point where the latter becomes smaller than the former, the electromagnetic check valve is deenergized to release the braking force. . [Problem to be Solved by the Invention] As described above, in the braking force holding device of Patent No. 1111-2-94042, the half-clutch position, that is, the braking force release point changes due to wear of the wire and clutch plate. Adjustments had to be made each time, and furthermore, the braking adjustment operation caused a problem in that the feeling at the moment the braking force was released varied slightly from driver to driver. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a braking force holding device that can automatically and accurately detect the point at which the braking force is released without using a manual adjustment element. (Means for Solving 1m11) As a means for solving the above problems, the braking force holding device according to the present invention includes an electromagnetic check valve, a clutch stroke sensor, an input shaft rotation sensor, The gear position sensor and the brake force release point are learned by adding a correction amount according to the clutch engagement speed to the clutch stroke at which the input shaft starts rotating when the clutch is engaged when the gear position is neutral, and the braking force release point is determined when the brake force is released under certain conditions. A control means is provided that energizes the check valve to generate braking force and deenergizes the check valve when the clutch stroke reaches the braking force release point. 4-

[For production]

In the braking force holding device of the present invention, the control means controls the input shirt of the transmission to start rotating due to clutch contact when the output of the gear position sensor indicates that the gear is in a neutral state. Clutch stroke is input from the brake sensor, and the point obtained by adding a correction amount according to the clutch connection speed to this 9,000 stroke is learned as the braking force release point #4°, that is, this is the 4th stroke. As shown in the figure, this is because the amount of clutch stroke at which the clutch actually transmits sufficient torque changes depending on the clutch engagement speed, and as the clutch engagement speed increases, the clutch stroke amount changes from the start of rotation of the input shaft. It can be seen that the need for correction increases. The control means energizes the electromagnetic check valve under predetermined conditions to generate braking force, and then activates the electromagnetic check valve when the clutch is returned to the extent that the clutch stroke reaches the braking force release point learned as described above. The braking force is released by deenergizing the stop valve. In this way, the point at which the braking force is released is automatically determined, so that it is possible to automatically respond to wear of the clutch plates, etc. [Embodiment] Fig. 1 is a diagram showing the hardware configuration of an embodiment of the braking force holding device according to the present invention. Accelerator switch that turns off, 3 is a variable resistance clutch stroke sensor that detects the stroke amount when clutch pedal 4 is depressed, 5 is parking (hand)
The parking brake switch is turned on when the brake switch is pulled and the brake is operated, and 7 is the foot brake (stop lamp) that is turned on when the brake pedal 8 is depressed.
The switch 9 is a gear position sensor that detects the gear position of the transmission (T/M) 10.
A neutral switch that turns on when neutral is detected; 11 is a vehicle speed sensor that detects the speed of the vehicle from the rotation of the output shaft (output shaft) 12 of the transmission 10; 13 is the start of rotation of the input shaft (power shaft) when the clutch is engaged. The input shaft 9 that detects the input shaft 9 and the control unit 15 as a control means that inputs the detection amount 5'f of the sensor 3, 11.13 are already activated when the brake pedal 8 is deenergized by the output signal from the control unit 14. By depressing the brake, the brake fluid sent to the wheel brake 17 through the hydraulic route +6a flows backward through the route 16b to release the braking force.
This is an electromagnetic check valve for braking that, together with a, prevents backflow of control oil and maintains braking force. Note that the output signal of each sensor is processed by the control unit 14 in the same way as normal analog signal processing.
The signal is once A/D converted at the entrance of the system and then used for control. FIGS. 2 and 3 are flowcharts of a program stored in advance in the control unit 14, and the operation of the embodiment of the present invention will be described below with reference to flowchart 1. In FIG. 2, first, the control unit 14
Check whether the gear of transmission (T/M) 10 is in the neutral position (step S21 in Fig. 2).
. When it is determined that the input shaft is not in the neutral position, the input shaft is rotated from the wheel side by the gears of the transmission 10, so it is not possible to detect the clutch engagement state due to the rotation of the input shaft, and the process proceeds to step 326. Go ahead and reset the flag. When it is determined that the input shaft is in the neutral position, the state of the input shaft is checked (step S2
2). When the input shaft (not shown) of the transmission 10 is not rotating and is at °0, a flag is set (step 327), and the process proceeds to the control routine shown in FIG. 3; however, if the input shaft has started rotating, the flag is set. Next, the flag is checked (step S23). As a result of checking the flag here, if the flag is set, this indicates that the rotation of the input shaft has just started, and the process proceeds to step S24. However, if the flag has been reset, as will be described later, Since at least one cycle of this program has elapsed since the first rotation, the program proceeds to the control routine shown in FIG. In step 324, the current clutch stroke X is read from the amount detected by the clutch stroke sensor 3 (step S24). Here, the start of rotation of the implant I shaft due to clutch engagement differs depending on the clutch engagement speed. When the clutch is engaged, the difference between the contact of the clutch and the start of rotation is small, but when the clutch is engaged at high speed, the start of rotation is delayed due to inertia in the clutch plate and transmission, and is on the engagement side. Therefore, the amount of correction according to the speed of clutch engagement is stored in advance in the controller/roll unit 4 as a correction lamp (Fig. 4 (C)), and the clutch stroke The value obtained by adding the correction value obtained from the correction map of Fig. 4 (C) corresponding to the clutch speed (dx/dt) at that time obtained from the output of step 3 (when the clutch stroke amount of the new example is increased) is The braking force release point is learned as 5TII (step 525). Then, it is assumed that the learning has been completed and the flag is cleared (step 526), and thereafter the operations shown in the flowchart shown in FIG. 3 are performed. The learning operation shown in Figure 2 is performed on the premise that the driver may change the gear to neutral and release the clutch while the driver is stopped; otherwise, the learning operation is performed in some way. An instruction may be given to prompt the user to perform the operation. After the above steps, the normal braking force holding/release control shown in FIG. 3 is executed. Note that this control can use the well-known control already disclosed in the above-mentioned publication, but in the present invention, steps S2 and 31 are performed as described below.
Step 1: Stroke value for braking force release learned above STI+
The difference is that it uses In Fig. 3, the control I/roll unit 14 first determines whether the accelerator pedal 2 is not depressed and is released and the accelerator switch (SW) 1 is in the on state. (Step 31 in Figure 3). When it is determined that the clutch is on, the clutch operation is checked (step S2). That is, the A/D converted value of the resistance value of the clutch stroke sensor 3 that detects the stroke amount of the clutch pedal 4 is compared with the braking force release stroke value 5TII obtained in step S25 in FIG. When the value is larger than the braking force release value STI+, it is determined that the clutch is in the "disengaged" state. In this step S2, the gear is in the neutral position regardless of the position of the clutch, so even if the neutral switch 9 is on, it may be 1-. When it is determined in step S2 that the vehicle is not driven, it is checked whether the brake pedal 8 is depressed and the foot brake switch 7 is turned on (step S3). When the brake pedal is depressed, it is preferable to check whether the parking brake 6 is pulled and the parking brake switch 5 is turned off (step S4). This is because the parking brake generates braking force in a completely different system, and when the driver pulls the parking brake halfway, if the wheel brake is applied by the foot brake, the check valve 14 This is because there is a risk that the holding pressure will drop due to valve leaks, etc., and the braking state will collapse. Therefore, when the parking brake 6 is not applied and the parking brake switch 5 is off, the braking is permitted and the process proceeds to step S5. 12- In step S'5, it is determined whether the vehicle speed signal (pulse 1 signal) from the speed sensor 111 indicates the predetermined speed. - Predetermined series and degrees of this station, each vehicle speed sensor 1.1 degrees, □°pa 0,
The vehicle speed is as close to 0 as possible, so the speed is as close as possible to 0. The vehicle speed is 0.
When the vehicle is almost at a standstill,
Hiro ``Qj Hayabusa 1's deceleration is less than the predetermined deceleration''->''
2. It is preferable to blow apricots. (same stage rev 'S6)'. ：The problem is that if you turn on the control while the vehicle is driving in the rain or snow, the tires will slip and lock up, and it is dangerous to maintain this braking condition. It is. After this, a diagnosis is made to see if there is any abnormality in the vehicle speed sensor 11 (step S7 of the same step). This is the I] level of the pulse signal normally generated by the vehicle speed sensor (for example, 14).
When a pulse other than the intermediate level between the low level and the low level (for example, 2V) is generated, it is determined that the sensor is abnormal. When all of the braking permissible states in steps 81 to S7 are satisfied, it is preferable to check whether this state continues for a certain period of time (step S8
). This certain period of time means a common-sense delay time (grace) for assuming that the driver intends to maintain the braking force. Furthermore, this duration can be determined more accurately in step S5 by using another delay time when the vehicle is considered to have stopped. After a certain period of time has elapsed in this manner, the control unit 15 generates a signal for energizing the braking electromagnetic check valve 16 (step 39). Through the processing up to this point, the braking force is applied and the vehicle comes to a stop. Next, when starting the vehicle, the accelerator pedal 2 must be depressed and the engine must be able to drive the vehicle, so if the accelerator switch 1 is off, Proceeding from step S1 to step Sll, the neutral switch 9 is not in the neutral position and is therefore off, and the clutch pedal 4 is returned and the amount of flow is equal to the braking force release value STH of step S25 in FIG. If it is detected that the braking force has become smaller, it is preferable to check the duration time in order to assume that there is an intention to start (remove the braking force) (step 510), and then check the duration time. If the elapsed time has elapsed, the braking electromagnetic check valve 16 is deenergized and the braking force is released from the same step S]
2), Yf' for departure! Do 6tM. Even if the accelerator pedal 2 is not depressed, the neutral switch 9 is not in the neutral position and is therefore off, and the old clutch pedal 4 is returned and its stroke amount is equal to the braking force in step 325 in FIG. Release value 5
If it is detected that it is smaller than T11,
Again, the check valve 1G is deenergized, the braking force is released, and the vehicle prepares for departure. It is preferable to set a certain duration time (a delay time when the transmission 10 is considered to be in a state other than neutral and a delay time when it is considered that there is an intention to start) in this step as well (step S5 10 in the same step). ). That is, at least the clutch stroke is equal to the braking force release value S
If the gear is not in the neutral state, the braking force will be released. Finally, if the parking brake 6 is pulled in step S4 and the parking brake switch 5 is turned on, the process proceeds to step 310 as in the case of the accelerator switch l, and it is assumed that the parking brake 6 has been applied. It is preferable to check the duration of the failure. [Effects of the Invention] As described above, the braking force retention device of the present invention has the advantage that a correction amount corresponding to the clutch engagement speed is added to the clutch stroke at which the input shaft begins to rotate when the clutch is engaged when the gear position is in the neutral state. The brake force is learned as the braking force release point, and the braking force is released when the clutch stroke reaches this braking force release point, so even if the clutch plate wears out, the braking force is automatically adjusted in response to this learning. Can be released accurately. 6

[Brief explanation of drawings]

FIG. 1 is a hardware configuration diagram showing an embodiment of the braking force holding device according to the present invention, and FIG. 2 is a diagram of a program stored and executed in the control unit of the present invention.・FIG. 3 is a diagram of a program for normal braking force retention/release control that is stored in the control unit of the present invention and is executed, and FIG. It is a graph diagram for explaining the relationship between connection speed and braking force release. In FIG. 1, numeral 3 represents a clutch stroke sensor, numeral 9 represents a neutral switch as a gear position sensor, numeral 13 represents an input shaft rotation speed sensor, and numeral 14 represents an electromagnetic check valve of a control unit. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] An electromagnetic check valve, a clutch stroke sensor, an input shaft rotation speed sensor, a gear position sensor, and a clutch stroke in which the input shaft starts rotating when the clutch is engaged when the gear position is in the neutral state, depending on the clutch engagement speed. The point where the correction amount is added is learned as the braking force release point, and under predetermined conditions, the check valve is energized to generate braking force, and when the clutch stroke reaches the braking force release point, the check valve is activated. A braking force holding device comprising: a control means for deenergizing the braking force holding device.