JP2748365B2 - Braking force holding device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a braking force holding device, and more particularly to a device for smoothly and safely releasing a braking force of a vehicle. [Prior Art] When starting a vehicle stopped on an uphill road, in a conventional vehicle, a driver uses a parking brake (handbrake) with one hand, gradually applies a braking force to the vehicle, and gradually releases a clutch while maintaining the vehicle in a stopped state. And go down the accelerator pedal at the same time. During this time, the parking brake is gradually released. However, since a complicated operation is required while coordinating such a brake and an accelerator, skill is required to perform a smooth start, and a so-called engine stall or vehicle retreat is caused. Accordingly, the present applicant has filed Japanese Patent Application No. 58-117483 (Japanese Unexamined Patent Application Publication No.
No. 11719), a control electromagnetic check valve is provided between a master cylinder and a wheel cylinder associated with a brake pedal, and this electromagnetic check valve can be started smoothly from a stopped state on an uphill road. Accelerator pedal sensor, clutch stroke sensor, engine rotation sensor,
Output signals from the brake pedal switch, gear position switch, select position switch, and vehicle speed sensor are input to the electronic control unit (CPU), and the electronic control unit applies an electromagnetic check valve under certain conditions based on these input signals. The braking force is held or released by the wheel cylinder by vibrating or deenergizing. Such a braking force holding device is excellent in that the operation of the electromagnetic check valve and the operation of the friction clutch can be controlled synchronously, so that starting on an uphill road can be performed smoothly without any skill. However, due to wear of the clutch driven plate, changes over time, and variations, as well as variations in the clutch stroke sensor and variations during assembly, the braking force at the start was released too early, causing the vehicle to retreat on an uphill road. There was a drawback that the brake was dragged because it was too slow. In order to solve this drawback, the present inventor has previously proposed a braking force holding device shown in FIG. 5 in Japanese Patent Application No. 62-94042 of the present applicant. Hereinafter, this apparatus will be schematically described. In FIG. 5, reference numeral 1 denotes an accelerator switch which is turned on (contact connection) when the accelerator pedal 2 is released, and turned off when a depression is detected, and 3 is a variable resistance clutch which detects a stroke amount when the clutch pedal 4 is depressed. A stroke sensor, 5 is a parking brake switch that is turned on when a parking (hand) brake 6 is pulled and a braking operation is performed, 7 is a foot brake (stop lamp) switch that is turned on when a brake pedal 8 is depressed, and 9 is a transmission (T / M) Neutral switch that turns on when gear neutral of 10 is detected.
A vehicle speed sensor for detecting the speed of the vehicle from the rotation of the output shaft 12 of the vehicle, 13 is a variable resistor for manual setting as a clutch connection determination adjusting element provided near the driver's seat, 14 is a switch 1,
5, 7, 9, 11 and detection signal of sensor 3 and variable resistor 13
A control unit (CPU) 15 as a control means for inputting the output signal of the wheel 15 has been depressed by the output signal from the control unit 14, and has already depressed the brake pedal 8 so that the wheel 15 passes through the hydraulic routes 16a and 16b. When the brake petal 8 is released, the braking oil sent back to the brake 17 is caused to flow back through the route 16b to release the braking force, and when energized, the braking oil is prevented together with the hydraulic route 16a to prevent the control oil from flowing back. Is a solenoid check valve for braking (a valve for holding braking force). The output signal of the sensor 3 and the output signal of the variable resistor 13 are once A / D converted by an A / D converter at the entrance of the control unit 14 and used for control in the same manner as ordinary analog signal processing. ing. FIG. 6 is a diagram showing a flowchart of a program stored in the control unit 14 in advance. In this device, the accelerator 2 is depressed as an essential condition for putting the electromagnetic check valve 15 for holding the braking force in the braking state. Is not engaged (step S1), the clutch stroke is greater than the set value, the clutch is in a disconnected state, or the gear is in a neutral state (step S2), the foot brake is depressed (step S3), and the vehicle speed is below a certain value. (Step S5). When the gear is not in the neutral state and the clutch stroke is smaller than the set value and the clutch is in the engaged state (step
S2, S11) are required conditions. In addition, preferably, whether the parking brake is applied (step S4), whether the deceleration of the vehicle speed has fallen below a predetermined value (step S6), whether the vehicle speed sensor is normal (step S7), and a series of steps It is checked whether or not has continued for a predetermined time (steps S8 and S10). As described above, the variable resistor 13 for manual setting as the clutch connection determination adjusting element is used to enable the driver to adjust the determination of the amount of depression of the clutch, and this is compared with the output of the clutch stroke sensor 3 so that there is no variation. The braking force is maintained. [Problems to be Solved by the Invention] Such a braking force holding device proposed earlier by the present inventor uses a variable resistor for manual setting as a clutch connection determination adjusting element, and therefore, as shown in FIG. In addition, if the manual setting is set to an abnormal value, the braking force is released at the time of adjustment, and there is a new problem that a very dangerous state is caused. Therefore, an object of the present invention is to realize a braking force holding device that can absorb variations in clutch operation and that does not cause erroneous release of braking force. [Means for Solving the Problems] As means for solving the above problems, in the braking force holding device according to the present invention, between the braking fluid pressure generating means linked to the brake pedal and the brake operating means, A braking force holding valve for holding and releasing a braking force under predetermined conditions; a clutch position sensor for detecting a position of a clutch pedal; a neutral position detecting means for detecting a neutral state of a transmission; When the clutch position detected by the position sensor becomes closer to the set braking force release clutch position and the non-neutral state of the transmission is detected, the braking force holding valve is held by the braking force holding valve. A braking force release clutch position adjusting means for changing the position of the braking force release clutch. The braking force is released by the adjusting means only in the range of the clutch contact side with respect to the reference, based on the position where the gear is returned to the clutch contact side by a predetermined stroke from the current clutch position detected by the clutch position sensor. It is characterized in that the clutch position can be adjusted. [Operation] In the braking force holding device of the present invention, when the neutral state detecting means indicates the gear-in state, the control means controls the actual clutch position indicated by the clutch position sensor,
When the actual clutch position is closer to the connection side of the clutch than the adjustment position set by the braking force release clutch position adjusting means, the braking force holding valve is deenergized to reduce the braking force. Cancel. In this case, the adjustment position by the adjusting means is determined based on a position at which the control means is returned to the clutch engagement side by a predetermined stroke from the current clutch position detected by the clutch position sensor. Since the adjustment of the braking force release clutch position by the adjustment means is enabled only in the range on the side, unnecessary release of the braking force can be prevented even if the adjustment of the adjustment means is erroneous. [Embodiment] Hereinafter, an embodiment of the braking force holding device according to the present invention will be described. FIG. 1 is a diagram showing a hardware configuration of an embodiment of a braking force holding device according to the present invention. The difference from FIG. 5 is that a braking force release clutch position adjusting element is adjusted instead of a manually-set variable resistor. That is, the switch SW is used. The adjustment switch SW is a so-called seesaw type automatic return switch (a well-known switch used for an auto cruise coast switch, a resume switch, or a side mirror adjustment switch) as shown in FIG. As shown in FIG. 7A, the switching contact is not connected to either the fixed contact or the fixed contact, and the clutch position for releasing the braking force is not adjusted at all. FIG. 2 (b) shows a state in which the switching contact is connected to the fixed contact, and this state shifts the clutch position for releasing the braking force to the side where the clutch is released (hereinafter simply referred to as the disconnected side) as described later. Made to adjust. However, since this switch is of the automatic return type, it is necessary to push the switch after tilting the switch to the left as shown in the figure. Adjustment of the clutch position for releasing the braking force
Executed in response to the time the SW is pressed. FIG. 2 (c) shows a state in which the switching contact is connected to the fixed contact, and this state changes the braking force release clutch position to the clutch connecting side (hereinafter simply referred to as the contact side) as described later. It is done to adjust to).
Others are the same as the case of FIG. 2 (b). As described above, when the clutch is connected from the clutch position corrected and set by the adjustment switch SW, the braking force is released. The value corrected by this adjustment switch SW is stored in the RAM (first
(See the figure) and retains that value until reset. However, when the correction value has not been set due to the removal of the battery or the control unit, the braking force is released using the backup value. The larger value of the value (adjustment position) stored in the RAM and the value indicating the actual clutch position detected by the clutch sensor 3 indicates the clutch disengagement side. The clutch stroke sensor 3 in FIG. 1 is a clutch position sensor for detecting a clutch position. FIG. 3 is a diagram showing a flowchart of a program stored in the control unit 14 in advance. The operation of the embodiment of the braking force holding device of the present invention will be described with reference to this flowchart. Note that the output signal of the accelerator switch 1 does not have to be particularly used. First, the control unit 14 reads output signals from the vehicle speed sensor 11, the clutch sensor 3, the parking brake switch 5, and the neutral switch 9 at regular intervals, and adjusts the adjustment switch SW held in the RAM in the control unit 14. The value, that is, the adjustment position is read (step T1 in FIG. 3). Next, it is checked whether the electromagnetic check valve (M / V) 15 for holding the braking force is currently on (braking force holding state) or off (braking force release state) (step T2). If it is on, it is checked from the output of the neutral switch 9 whether the gear is in neutral (step 3). When the gear is not in neutral, the adjustment switch
Check if SW is pressed (same step
T4, 5). In step T4, it is checked whether or not the adjustment switch SW is pressed for the clutch contact side adjustment (the state shown in FIG. 2 (c)).
SW is pushed for clutch side adjustment (Fig. 2 (b)
State). When the adjustment switch SW is operated to adjust the braking force release clutch position to the clutch contact side, the adjustment position corresponding to the value stored in the RAM is compared with a constant value β (step T6). As shown in FIG. 4, this constant value β is set to a value slightly closer to the “disengaged side” than a known position where the clutch has returned, and a contact side condition is provided. As a result of this comparison, when the adjustment position is larger than β and the braking force release clutch position is still on the disengaged side, subtract a constant value x from the current adjustment position toward the contact side, and use this as a new adjustment position. Store in RAM (Step T
7). If the constant value x is set to, for example, "1", the adjustment position stored in the RAM decreases by "1" every time the routine shown in FIG. 3 is executed at regular intervals. When the adjustment position is smaller than β, as shown in FIG. 4, since the adjustment position is adjusted to the contact side so that it is not necessary to move the adjustment position to the contact side, the process proceeds to step T8 as in the case where step T7 is executed. In step T4, when the adjustment switch SW is not pushed to the contact side but is pushed to the disconnected side (in the case of FIG. 2 (b)),
This is detected in step T5, and it is checked in step T9 how the adjustment position is in relation to the actual clutch position detected by the clutch sensor 3. That is,
As shown in FIG. 4, assuming that the actual clutch position is shifted toward the contact side by a margin value (margin) for setting the disengagement condition of α as shown in FIG. 4, the adjustment position is closer to the adjustment position than this simulated clutch position. When is smaller, it is determined that there is still enough margin on the disengaged side, and a fixed value x is added to the adjustment position, and the adjustment position is shifted to the disengaged side (the same step T10). Then, the process proceeds to step T8. When the adjustment position is larger, the adjustment position falls within the α region shown in FIG. 4, and therefore the process proceeds to step T8 without moving the adjustment position to the disconnected side. When no adjustment switch SW is operated, step T4
And go directly to step T8 through T5. In step T8, the actual clutch position detected by the clutch sensor 3 is compared with the above-mentioned adjustment position held in the RAM, and when the value indicating the clutch position by the clutch sensor 3 is smaller than the value of the adjustment position, the clutch Is connected and turns off check valve 15 (step
T11) When the braking force is released and the clutch position value is equal to or greater than the adjustment position value, it is assumed that the clutch is disengaged. If the parking brake 5 is in the released state (the same step T12), a check is made. The valve 15 is maintained in the ON state (step T13), and the braking force is maintained. However, if the parking brake 5 is in the braking state, the braking force is released in step 11. The state of the parking brake 5 is also checked when the gear is in a neutral state (step T3). This parking brake check step is not essential, but the parking brake is a completely separate system that generates braking force, and when the driver applies the parking brake halfway, the foot brake This is because, if the wheel brake is applied, the holding pressure may decrease due to valve leak of the check valve 15 or the like, and the braking state may be broken. In addition, the following steps are preferably performed. It is checked whether the brake pedal 8 is depressed and the foot brake switch 7 is turned on (step T14). In step T15, it is checked whether the vehicle speed signal (pulse signal) from the vehicle speed sensor 11 indicates a predetermined speed V or less. The predetermined speed in this case is a speed as close as possible to “0” because the vehicle speed sensor 11 cannot detect the speed “0”. When the vehicle speed is close to "0", that is, when the vehicle is almost stopped, it is preferable to check whether the vehicle speed is lower than a predetermined deceleration (step T16). This is because, when the vehicle is braked in rain or snow, if the brake is applied, the tires slip and the wheel clock state is exhibited, and it is dangerous to maintain the brake state. In these steps T14 to T16, the foot brake 8 is released, and the vehicle speed is not close to "0".
When the deceleration is still large, the routine shown in FIG. 3 ends. At other times, it is checked whether the gear is in a neutral state (step T17). If the gear is in a neutral state, the process proceeds to step T12. If not, the process proceeds to step T8 to reduce the braking force as described above. Release or hold. Needless to say, it is easy for those skilled in the art to configure the above software control with a heart wear circuit as shown in Japanese Patent Application No. 62-94042. [Effects of the Invention] As described above, in the braking force holding device of the present invention, in order to release the braking force, the gear is not in the neutral state and the actual clutch position is more than the adjustment position by the braking force release clutch position adjusting means. The brake force is released when the clutch is on the clutch contact side, and the adjustment position of the adjusting means can be limited, so that the braking force is not accidentally released at the time of adjustment. Thus, the effect that the optimum braking force release clutch position can be known can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a hardware configuration diagram showing an embodiment of a braking force holding device according to the present invention, and FIG. 2 is an operation of an adjustment switch used in the braking force holding device according to the present invention. FIG. 3 is a flowchart of a program stored in the control unit of the present invention, FIG. 4 is a diagram showing adjustment of a braking force release clutch position in the present invention, and FIG. FIG. 6 is a hardware configuration diagram showing an embodiment of a braking force holding device disclosed in Japanese Patent Application No. 62-94042 of the present applicant. FIG. 6 is a flowchart diagram of a program used in FIG. In FIG. 1, 3 is a clutch sensor, 9 is a neutral switch, 14 is a control unit, 15 is an electromagnetic check valve for braking, and SW is an adjustment switch as a braking force release clutch position adjusting element. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] A braking force holding valve provided between the braking fluid pressure generating means and the brake operating means associated with the brake pedal for holding and releasing the braking force under predetermined conditions, and a clutch position for detecting the position of the clutch pedal A clutch, a neutral position detecting means for detecting a neutral state of the transmission, and a clutch position detected by the clutch position sensor being closer to a contact side than a set braking force release clutch position, and a non-neutral of the transmission. Control means for canceling the holding of the braking force by the braking force holding valve when a state is detected, comprising: a braking force release clutch position adjusting means for changing the position of the braking force release clutch. The control means returns to the clutch contact side by a predetermined stroke from the current clutch position detected by the clutch position sensor. A braking force holding device characterized in that it is possible to adjust the braking force release clutch position by the adjusting means only in the range of the clutch contact side with respect to the reference.