JPS59130771A - Proportional controller for brake - Google Patents

Abstract

PURPOSE:To have optimum proportion of distributed braking force in accordance with the load applied to a car, by furnishing a solenoid-operated valve between the inlet to a proportioning valve and the control chamber, and by controlling this opening/closing valve so as to present a performance with a transition of curvature as in correspondence to the load applied to the car. CONSTITUTION:A solenoid valve 29 is interposed in a communication line to connect a control chamber 282 and a plunger chamber 281 leading to the inlet port of a proportioning valve 28. The transition point of curvatures of the front wheel braking pressure and rear wheel braking pressure is changed by a push force, at which a spring pressure adjusting plunger 284 pushes a coil spring 285 operated by a pressure from the above-mentioned control chamber 282. The pressure in the control chamber 282 is controlled by the above-mentioned solenoid valve 29, which is in turn controlled by CPU. That is, the CPU senses the load applied to the car as well as the brake operating speed and the deceleration, the latter two being made during brake application, and these three values shall serve setting of the transition point, and when the input port pressure has attained this transition point, current is supplied to the solenoid valve 29.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to proportional control of vehicle brakes, and more particularly to a proportional control device that automatically generates just the right amount of braking force depending on the magnitude of vehicle load such as live load.

The braking system of a vehicle is divided into the front wheel system and the rear axle system, and in order to properly distribute the braking force between the front wheel system and the rear axle system, a proportion is generally set between the brake mask cylinder and the rear wheel brake system. A brake pressure control valve device called a braking valve is inserted. This applies a relatively high pressure proportional to the output pressure of the mask cylinder to the rear wheel brake system up to a certain pressure, but once the output pressure of the mask cylinder rises to the set pressure, from there the output pressure increases. Apply a proportional and relatively low pressure to the rear axle brake system. This is to prevent the rear wheels from locking up. However, even with this proportional control, the distribution of braking force is not sufficient. In other words, the distribution of the braking force on the front wheels and the braking force on the rear wheels is as shown in the solid line A shown in Fig. 3 when the vehicle is empty.
The one indicated by j is ideal; the further below the solid line Ai, the insufficient braking force, and the higher the position above the solid line Ai, the more likely the rear axle will be locked. The aforementioned provisioning valve distributes the braking force as indicated by the dotted line Aa in FIG. 3, for example. In this example, the provisioning valve reduces the upward slope of the rear wheel braking force at point Pc1. However, when the braking force distribution is adjusted in this way when the vehicle is empty, as the vehicle load increases, the ideal distribution becomes B i, ci, Di.

E", the weight becomes higher on the rear wheel side, and with the characteristics of Aa, the braking force of the rear wheels becomes insufficient. Conventionally, an inflection point is set that is considered to be the safest, but no matter which setting is made, if the vehicle load deviates significantly from the planned value, the distribution of braking force between the front and rear wheels will deteriorate. . Therefore, the pressure in the control chamber of the proportioning valve is controlled by an inertia pole to reach the inflection points (Pc1', pc2.Pc3...
・) An inertia valve is sometimes used, which changes the amount depending on the vehicle load. When using this inertia valve, the inflection point is determined by the inertia force of the inertia pole due to deceleration during braking, so it is easily affected by vibration, and it is also affected by the speed at which the brake is depressed. Because of this, sudden braking at low loads and high speeds can easily cause the rear wheels to lock. Also, the brakes are not effective under high loads and low speeds.

The first object of the present invention is to provide a proportional control device that accurately exerts a well-balanced braking force without excess or deficiency from an empty vehicle to a heavily loaded vehicle. A second object of the present invention is to provide a proportional control device that is highly resistant to disturbances such as vibration.

In order to achieve the above object, in the present invention, a solenoid on-off valve is inserted between the input pressure of the provisioning valve and the control chamber, and the vehicle load is detected and the inflection point corresponding to the vehicle load is determined. When the brake pressure reaches the inflection point, the solenoid valve is closed and the braking force distribution ratio is changed. That is, the inflection point is changed according to the vehicle load.

When the speed of applying the brake is high, it is generally preferable to apply the brake quickly. Therefore, in a preferred embodiment of the present invention, the rate of increase in brake pressure is detected and a corresponding correction is made at the inflection point. Add. Further, it is preferable to adjust the braking force with respect to the depression of the brake depending on whether the brake force is good or bad, so in a preferred embodiment of the present invention, the deceleration at a predetermined brake pressure is detected and the deceleration is reduced. Correct the inflection point accordingly.

In one aspect of the vehicle load, the load is repeatedly detected before the vehicle runs, and the detected value immediately before the vehicle starts is used as the detected load. Load detection is done by detecting the vehicle height with a vehicle height detector in vehicles without vehicle height adjustment, or by detecting the support pressure of the suspension system, and in vehicles with vehicle height adjustment, by detecting the vehicle height and load. Since there is no correlation between the two, the support pressure of the suspension system is detected.

In other embodiments, for example, as disclosed in Japanese Patent Application No. 56-45322, the vehicle load may be detected based on the rate of change in engine speed when the vehicle begins to move slightly by applying slight pressure to the clutch. good. The deceleration of the vehicle is detected by an acceleration detector or by calculating the acceleration (deceleration) of the vehicle speed. Brake system pressure is detected by a pressure sensor.

Inflection point equivalent pressure corresponding to vehicle load (Pc1゜Pc2 r
P C3+...) may be obtained by substituting the load value into a predetermined formula and calculating it, or it may be stored in a memory such as ROM in advance in association with the load and accessed using the detected load value. It may also be read out. The inflection point correction value depending on the brake depression speed and the inflection point correction value depending on the brake application may also be obtained by calculation, or may be read out from memory.

FIG. 1 shows the configuration of an embodiment of the present invention. In this embodiment, the present invention is applied to a vehicle that automatically adjusts the vehicle height. First, the configuration of the vehicle height adjustment system will be explained. 1 is a front right suspension system, 2 is a front left suspension system, 3 is a rear right suspension system, and 4 is a rear left suspension system. The air compressor 5 is driven by a motor M and supplies air to the front suspension systems 1, 2- through an on-off valve 7, and to the rear suspension systems 3, 4 through an on-off valve 8. 9 is an air dryer, and 10 is a main system supply/exhaust valve. Energization and deenergization of the motor 6 is controlled by a relay 11. The on-off valves 7 and 8 and the supply/exhaust valve 10 are of the solenoid energized type; the former opens (input/output communication) when the solenoid is energized, and the latter switches to exhaust to the atmosphere and the solenoid is deenergized. In this state, the former is closed (input/output cutoff), and the latter is in communication with the input and output ports. These relays 11 and air control valves 7, 8, 1.0 are connected to the amplifier 3512 of the control unit CMU.
~3515. 4t of potentiometers 12 to 15 are respectively attached to the vehicle body near the suspension systems 1 to 4 in association with each other. The rotary shaft (slider) of the potentiometer is connected to the axle via a link. Potentiometers 12 to 4 are control devices that control the voltage according to the height between the axle and the vehicle body c) xi
V is applied to the amplifiers 351 to 354.

The details will be described later, but the control device CM 1. J reads the vehicle height with potentiometers 12 and 13, and sets the target vehicle speed from the vehicle speed.
0 is opened to lower the vehicle height, and when the detected vehicle height is lower than the target value, the motor 6 is driven to open the valve -' to raise the vehicle height. Similarly, to adjust the rear vehicle height, refer to the detected vehicle height value of potentiometer 14.15. If the detected vehicle height is higher than the target value, valves 8 and 10 are opened to lower the vehicle height, and the detected vehicle height is lower than the target value. If the height is too low, the motor 6 is driven to open the valve 8 and raise the vehicle height.

Next, the configuration of the proportional control system will be explained. When the brake 25 is depressed to the foot 1, the booster 26 and the mask cylinder 27 generate brake hydraulic pressure, and the brake 2 of the front axle is activated.
1.22 and the rear axle brakes 23, 24. A proportional valve 28 is inserted in the hydraulic line between the mask cylinder 27 and the rear brakes 23, 24, and a pressure sensor 30 detects the hydraulic pressure of the rear brake system.

Input hydraulic boat of proportional valve 28
~ There is a solenoid between the roll chamber input boat.

A closed valve 29 is inserted. A pressure sensor 16 is connected to the air line of the front suspension system, and a pressure sensor 17 is connected to the air line of the rear suspension system to detect the support pressure of the suspension system. The detection signal of sensor 6 indicates the front load, and the detection signal of sensor 17 indicates the rear load.

In addition to the above-mentioned elements, the vehicle includes a switch 1 to a brake operation detection switch 31. Door open/close detector DSi-DS
4. Parking brake operation detection switch 32. An acceleration/deceleration detector 33 and a vehicle speed pulse generator 34 are provided. The acceleration/deceleration detector 33 movably supports the rear end of a leaf spring having a steel ball fixed to its tip, and connects the leaf spring with a spring.
It has a rain gauge attached to it, and when acceleration or deceleration is applied, a plate spring is bent by a steel ball, generating a voltage corresponding to the acceleration or deceleration. In vertical vibration, the leaf spring slides up and down and no bending force is applied to the temporary spring, so it is applied.

Virtually no deceleration voltage is generated.

The vehicle speed pulse generator 34 has a magnetic gear fixed to a vehicle speed cable driven by the output shaft of the transmission, and generates electric pulses by rotation of the gear with a coil.

” Dual solenoid valve 29. Foot brake switch 3
1. Parking placket inch, door switch DSL
~DS4. Pressure sensor 30. Acceleration and deceleration detectors and a vehicle speed pulse generator 34 are also connected to the amplifier of the control device CMtJ.

In this embodiment, the micro-booster 37 of the control device CMU performs automatic vehicle height adjustment and brake proportional control.

Of the various detectors mentioned above, the signals processed by the amplifier are applied to an 8-channel A/D converter 36, which generates analog signals, and the processor 37 specifies each of the six channels under A/D conversion control. Read the detected value with digital data. Among the above-mentioned various detectors, the waveform shaping signal from the amplifier that generates a binary signal is applied to the processor 37, and controlled elements (actuators) such as relays and solenoid valves are connected to two output ports of the processor 37.
The activation is controlled via an amplifier depending on the value signal level.

The signals on each signal line in the control unit CMU of FIG. 1 are as follows.

31 to S4: Vehicle height detection signal (analog) Pl: Front load of the vehicle (analog) PP: Rear load of the vehicle (analog) P3: Hydraulic pressure from the mask cylinder to the rear brake system (
(Input pressure) SG: Acceleration, deceleration (analog) FB: Foot brake operation detection signal (binary) 11B: Parking brake operation detection signal (binary) PP: Vehicle speed pulse (binary) D1 to D4: 1 to Lua open Signals (binary) A-C, E: Solenoid valve direction signal (binary) D = Relay energizing signal (binary) FIG. 2 shows the structures of the proportional valve 28 and the solenoid valve 29. The proportional valve 28 has substantially the same structure as a conventional proportional valve, and the plunger chamber 281 communicating with the input boat and the control chamber 282 are connected through a solenoid valve 29, whereas in the past, the plunger chamber 281 communicates with the control chamber 282. I try to do this. The distribution of the braking force of the rear brake, that is, the slope between the origin O and Pc1 in Fig. 3 is the same as that of the front wheel braking force according to the input oil pressure with the slope shown by the broken line in Fig. 3, and each inflection point Pc
l, Pc2, Pc3, Pc4.

From Pc5 onwards, the slope is the diameter A of the core of the plunger 283 and the diameter B of the flange, as shown by the dotted lines in Fig. 3.
A pressure obtained by multiplying the input oil pressure by a coefficient determined by the slope is applied to the brakes 23 and 24. When the solenoid valve is closed when the input oil pressure is equivalent to the Pc1 point shown in FIG. 3, the braking force distribution becomes the dotted line Aa, and when it is closed at a value equivalent to the Pc2 point, the braking force distribution becomes the dotted line Ba. In other words, the more the solenoid valve 29 is closed after the input oil pressure becomes high, the more the control chamber 282
, the force of the spring pressure adjustment plunger 284 pushing the coil spring 285 is large, and the inflection point is on the high oil pressure side (
(Large rear brake force distribution). Note that the plunger 283 of the proportional valve 28 is connected to the plunger chamber 28.
1 moves left and right while hydraulic pressure is applied to the brakes 23 and 24, and when the brakes 23 and 24 are opened and closed, the hydraulic pressure applied to the brakes 23 and 24 becomes a pressure at a predetermined ratio to the input hydraulic pressure. That is, the brake 23
．． The hydraulic pressure applied to 24 vibrates as shown in FIG.

The solenoid valve 29 has a valve plunger 291 pushed in the valve opening direction by a coil spring 292, and when the solenoid is energized, the plunger 291 is attracted by the core 293 and the valve is closed. When the valve closes, the plunger 29
The hydraulic pressure applied to the left end of 1 is greater than the hydraulic pressure applied to the right end (valve part), and the difference between them is also greater than the repulsive force of the coil spring, so even if the solenoid is de-energized afterwards, the hydraulic pressure is maintained. Keep the valve closed while

When the pressure in the plunger chamber 281 falls below the pressure in the control chamber and the solenoid is de-energized, the plunger is pushed to the left and the valve returns to the open state. In this way, the solenoid valve 29 is of a normally open type, and is also of a self-closing type.

Although the details will be described later, the control device CM'U detects the vehicle load, detects the brake operation speed and deceleration during braking, and detects the brake pressure bending point (inflection point) at the vehicle load, brake operation speed, and deceleration. point), and when the mask cylinder output oil pressure reaches the breaking point, solenoid #29 is energized,
Power is cut off after the valve is closed.

FIG. 5 shows the main flow of the brake pressure proportional control and vehicle height control of the control unit CMU, and FIG. 6 shows the interrupt control flow related to the brake pressure proportional control.

FIG. 7 shows the vehicle height control subflow.

The microprocessor 37 of the control device CMU performs vehicle height detection reading, vehicle load detection reading, and setting of a bending point (inflection point) corresponding to the vehicle load in the main flow shown in FIG. Proceed to the interrupt control flow shown in Figure 6, detect the brake operation speed and deceleration, find the corresponding correction values, perform the bending point correction, and when the flake oil pressure reaches the bending point pressure, solenoid 1 is activated. valve 29
energize. When the main flow (FIG. 5) proceeds to vehicle height adjustment, vehicle speed detection and vehicle height adjustment are performed in the flow shown in FIG. 7, and when this is completed, the main flow returns.

Even while the main flow is being executed or vehicle height adjustment is being executed, if a brake operation is performed, interrupt control is entered.

First, the main flow will be explained with reference to FIG.

When the device power (not shown) is turned on and the processor 37 is powered on, the processor 37 sets the input/output board to the initial state (the output cap-1- sets the output level at which safety is maintained). ) and registers.

Set flags and counters to conditions before starting control.

Next, a system check is performed, and if the system is in a normal state, the process proceeds to vehicle load detection and vehicle height detection. When a system abnormality is detected, an alarm (indicator light, buzzer, sound, etc.)
and continue the system check. Although not shown, in a detection system where a disconnection or the like causes a detection error and control to proceed in a dangerous direction, the system check will be correct.

An electric circuit and a checkerboard are set up to detect whether or not the system is operating properly, and only when the system check determines that the system is normal, the process proceeds to the following control.

Now, if the system is normal, the vehicle load detection value memoria1-resj is set to 1, P1 and P2 are digitally converted, and their sum is stored in register PL2i. P
l designates the input channel of the A/D converter as 4, instructs the converter 36 to perform conversion, and also provides a conversion synchronization clock to the converter 36, and reads the data that the converter 36 serially outputs in synchronization with the clock. Do it by doing this. A/1] conversion of other analog signals is performed in the same manner.

P ], + P After completing the memory of the digital data (vehicle load) indicating 2, this time SL and 82 are respectively A,
/ D conversion and the sum (front vehicle height) of register 51
21, then A/D conversion is performed on each of 83 and 84, and the sum thereof (rear vehicle height) is stored in a register 5341.

When the vehicle load and vehicle height are read and stored in memory in this way, memory address 1 is incremented by 1 and the timer (program timer) J″S that determines the reading cycle is set to cell 1.
- Opening/closing of all doors (Di~I]4) and status of foot brake and parking brake (FB, 1-I)
Referring to B), if either the foot brake or the parking brake is on (brake compression), the vehicle can be considered to be stopped, so proceed to adjust the vehicle height. After exiting the vehicle height adjustment, the program proceeds to the vehicle load reading memory and the vehicle height reading memory on the condition that the timer TS has timed out. Therefore, while the vehicle is stopped, the vehicle load and vehicle height are repeatedly read and stored in memory.

When memory address 1 becomes 5, it is reset to 1 again. As a result, when the machine is stopped, the data read four times most recently is held.

If someone gets on or off during this time, the read data will be rewritten to a corresponding value.Also, with vehicle height adjustment, which will be explained in detail later, the vehicle height will remain at the desired height when stopped even if someone gets on or off. automatically adjusted.

Now, when all the doors are closed, the parking brake is released, and the foot brake is also released, the processor 37 A/D converts the SG (acceleration, deceleration) and stores it in the register SGI. First, the contents of register SGI are moved to register SG2. Then, the difference 5GI-8G2 between the contents of registers SGI and SG2 (this is SGI in the first time, but becomes the increase in acceleration in the second and subsequent times) is compared with a predetermined value a, and it is determined that it is smaller than a. It is assumed that the vehicle has not started yet, and the process goes through the vehicle height adjustment step to the vehicle load reading memory and vehicle height reading memory, reads SG, and transfers the contents of register SGI to register S.
G2 and memorize the read data in register SGI,
Let's compare 5GI-8G2 and a. While repeating this, when 5GI-3G2≧a, that is, when the vehicle clearly starts, register PL2i (i = 1 to 4)
Calculate the sum of the contents (the latest four vehicle load readings),
The address is determined using the calculated value (digital data), and the bending point pressure data Pj (P in Fig. 3) is determined from the data table A in the ROM.
Equivalent to cl, Pc2, Pc3, =-...

These ideal values are stored in advance in the ROM in association with the load. ) is read and stored in the break point register. Note that if this memory is not stored (the car starts very slowly) and then the brake is pressed, the interrupt enable is not set, so even if the foot brake is pressed, the processor 37 is an interrupt (solenoid 29
The proportional valve 28, which enters the A' mode), operates in the same manner as a conventional proportional valve.

As mentioned above, when there is a memory of the turning point Pj (when the car starts normally), when the brake is stepped on, the solenoid valve 29, which will be described later, is energized when the input oil pressure is Pj. (To be precise, this is corrected.).

Now, when Pj is stored in the breakpoint register as described above, the processor 37 sets the interrupt response of the interrupt port T1 to enable. Since the detection signal FB of the brake operation detection switch is applied to port TI to foot 1, the FB
When the level reaches a level indicating that the brake is on (depression), the processor 37 proceeds to the interrupt process shown in FIG.

When the foot brake is not operated, the vehicle height (Sl
-S4), proceed to vehicle height adjustment, read the brake status and 1A opening/closing, and confirm that the brake is operated.
Moreover, if the door remains closed, that is, if the vehicle is moving without braking, only the vehicle height is read and the vehicle height is adjusted. When the foot brake is operated, the process proceeds to Figure 6, so step a1 of the main routine
The answer will never be yes. Yes to these steps
This is because the interrupt enable is not set (the car started very slowly), the driving is abnormal, or there is a system error, so proceed to the initialization at the beginning of the main flow and proceed to the system check. . In any case, when the interrupt does not work, the plunger chamber 281 of the proportional valve 28 and the control chamber 28□ remain in communication, and the brake is applied with the same braking force distribution as the conventional proportional valve.

When the foot brake is operated, the solenoid valve 29 is raised and closed at the set bending point Pj (more precisely, the value after the correction described later) by the interrupt processing shown in FIG. 6, and then the foot brake is released. Then, the process returns to the flow step immediately before entering the interrupt in the main routine (FIG. 5). If the parking brake is operated or the door is opened, the vehicle load may increase or decrease, so the process returns to the initialization at the beginning of the main flow via step a2 or step a3.

Next, interrupt control will be explained with reference to FIG.

As mentioned above, the interrupt is enabled only after the fold point pressure PJ corresponding to the load is stored in the fold point register. Now, when the footbrake is stepped on in this state, the FB is inverted to the interrupt level, and the processor 37 saves the current value of the execution address of the main program to the memory, and executes the interrupt processing program (the interrupt processing program shown in FIG. 6). Proceed to (include processing).

In the interrupt processing, first, the vehicle height adjustment is set to stop (valve 7, 8 and 10 are closed, motor 6 is stopped), and the output oil pressure P3 of the master cylinder is read and stored in the register P32. Then, the contents of register P32 are compared with a predetermined value, and if it is smaller than b, P32 is read and the memory is updated. When the foot brake becomes more than b, it can be considered that the foot brake has been depressed to the effective range and the brake oil pressure has started to rise. Therefore, read the SG at that time and set the timer Td from 1 to 1 to detect the brake depression speed. When the time is over, P again
3 and stores it in register P3]. The value obtained by dividing P3]-P32 by the time limit value of the timer Td is the rising speed of the brake oil pressure (output oil pressure of the mask cylinder), and the time limit value is constant.

P31-P32 indicates the brake depression speed. Further, the contents of the register SG indicate the deceleration when the brake pressure reaches a predetermined level, and this roughly indicates the force of the brake. Therefore, the processor 37 retrieves P31 from the data table B in the ROM.
- Read the bending point correction value Pm corresponding to P32, and
Read the breaking point correction value Pn corresponding to SG from the data table C of OM, and pan to the breaking point register contents ■] J.
and Pn are updated and stored in the break point register, and while the brake is on, the output oil pressure P3 of the mask cylinder is repeatedly read, and when P3 becomes equal to the contents of the break point register, the solenoid valve 29 energize.

Then, the timer 1'bs is set to zero, and when it times out (when the time 'rbs that is longer than the time to complete the valve closing has elapsed), the energization is cut off. After that, the flow waits for the brake on the runner 1 to be released, and when the brake is released, the flow returns to the main flow. Note that if the foot brake is released before the solenoid 29 is energized, the flow returns to the main flow.

Next, vehicle height adjustment will be explained with reference to FIG.

Proceeding to vehicle height adjustment, Prose, Tsusa 37 is 50 m5ec
Set the program timer execution count N to 10, clear the contents of the vehicle speed pulse counter I to register A (set to 0), and set the 50m5ec program timer. Then, wait for the human-powered boat T2 to change from rOJ low level to r]J high level, and when it goes from 0 to 1, the contents of the vehicle speed register 1-1 are incremented by 1 (A+1→A
). Then, wait until the vehicle speed pulse becomes a low level "0". When it becomes "0", it is checked whether or not the 50m5ec Progera 11 timer has timed out, and if the timer 11 has exceeded, the number of executions N is decremented by 1 (N-1-
+N), and if N is not O, the 50m5ec program timer is set to Sera 1 again to count and amplify the vehicle speed pulse.

When it becomes N or 0, the contents of the vehicle speed count register are memorized in the vehicle speed register, and if the detected vehicle speed (vehicle speed run 1 - register contents) A is 1100 K/h or more, the vehicle height target value is set to 113, A is less than 100 K m/h6
If the speed is over 0 km/h, the vehicle height target value is set to 119. If the speed is less than 60 km/h, the vehicle height target value is set to 1.
Change to Sera 1 on 25. As a result of the above, the vehicle speed pulse count number for 0.5 seconds, that is, the vehicle speed is stored in the vehicle speed register. This memory is retained until the next vehicle speed pulse count, so once the vehicle height adjustment has proceeded, the vehicle speed value will be retained in the vehicle speed register.

Now, when the vehicle height target value is set as described above, the processor 37 first enters the vehicle height adjustment of Freon 1~, adds and subtracts the upper and lower tolerance values X/2 to the set target value, and sets the vehicle height upper limit value LL. Calculate the lower limit value UL and register S12j, i = 1
Calculate the average F1 of the contents of ~4 (four front vehicle height target values). This number 1 is the current actual front vehicle height. Therefore, the processor 37 performs the following steps.

Then, compare the lower limit value with the actual front vehicle height, and if the actual vehicle height is less than the lower limit value, set the motor 6 to IW operation, set the solenoid If 7 to open, and turn on for 5 seconds. Set the program timer to 1-. This is 50 m s e
This is done by setting the number of executions of the c program timer to 100 and setting the 50m5ec program timer to 1. When the time is over, valves 7 and 8 are closed, motor 6 is set to stop (output cleared), and the rear (
Rear) Proceed to vehicle height adjustment. When the actual vehicle height is both at the upper limit value, the solenoid valves 7 and 8 are opened to Sera I, and a 1 sec program timer is set. This is done by setting the number of executions of the 50m5ec program timer to 20 and setting the 50m5ec program timer. Then, when the time is over, valves 7 and 8
Close, set motor 6 to stop (output clear), and proceed to rear vehicle height adjustment. When the actual vehicle height is between the upper and lower limit values, just to be safe, the valves 7 and 8 are closed, the motor 6 is set to stop (output cleared), and the process proceeds to rear vehicle height adjustment.

The rear vehicle height adjustment is similar to the front vehicle height adjustment described above (target value setting and front vehicle height adjustment), and when the rear vehicle height adjustment is completed, the process returns to the main routine.

However, the vehicle height target value for the 5th vehicle speed is not necessarily the same as the front target value. In order to optimize the vehicle's posture (leaning forward or leaning backwards) depending on the vehicle speed, target vehicle height values for the front and rear are determined independently.

Next, other embodiments and modifications of the present invention will be described.

In the above embodiment, since the vehicle height is adjusted, the vehicle height does not correspond to the vehicle load, so the load is detected by detecting the air pressure of the suspension system. For example, the load may be detected based on the detected values of the vehicle height detectors 12 to 14.

In the embodiment described above, acceleration/deceleration is detected by a so-called G sensor, but for example, in the vehicle speed detection of the embodiment described above, the vehicle speed is detected at a predetermined time interval and the difference between the two detected values before and after is calculated. Acceleration/deceleration detection may be performed using acceleration and deceleration. Further, as in the above embodiment, when obtaining a vehicle speed pulse, the period of the pulse (reciprocal of the vehicle speed) is counted,
The difference between two period detection values before and after a predetermined time interval may be detected as the acceleration/deceleration.

Furthermore, in the above embodiment, when the acceleration exceeds a predetermined value, load detection is stopped and the bending point pressure Pj corresponding to the load is set. You may do so.

Furthermore, in the above embodiment, the operation of the foot brake is detected by the foot brake switch, but the operation of the foot brake is detected when the output oil pressure of the mask cylinder 30 exceeds a predetermined value. Good too.

In the above-mentioned embodiment, the vehicle load is obtained by detecting the air pressure of the suspension system, but the present invention also includes an engine rotation speed detection means and a throttle valve opening/closing detection means to detect the rate of decrease in the engine rotation speed at the time of starting. The vehicle load may also be detected by

Furthermore, in the above-mentioned embodiment, the bending point pressure is set according to the vehicle load, the application of the brakes, and the speed at which the brakes are depressed. The point pressure may also be corrected. In the present invention, since the breaking point pressure is determined by the activation timing of the solenoid valve, it is also easy to correct the breaking point based on the amount of computer processing.

As described above, according to the present invention, it is possible to arbitrarily set the bending point pressure in accordance with the vehicle load and other conditions to obtain a desired proportional control characteristic. Especially when using an advanced electronic control device such as a microprocessor, various proportional control characteristics can be set accurately and precisely based on many parameters.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention;
FIG. 2 is an enlarged sectional view showing the structure of the proportioning valve 28 and solenoid valve 29 shown in FIG. 1, and FIG.
Figure 4 is a graph showing the ideal distribution of braking force between the front and rear wheels (solid line) and the actual distribution by the provisioning valve (dotted line). 5, FIG. 6, and FIG. 7 are flowcharts 1- showing the control operation of the processor 37 shown in FIG. 1-4: IV! ! Elevation device 5: Compressor 6: Motor 7.8, 10.29: Solenoid valve 9: Air dryer 11: Relay 12-15: Potentiometer (vehicle height detector) 16.1
．． 7: Pressure sensor (means for detecting vehicle load) 21-2
4 Ni brake 25: Knot brake pedal 26: Booster 27: Mask cylinder 28: Proportioning valve (proportional control valve) 30: Pressure sensor (means for detecting input pressure) 31: Foot 1-Brake operation detection switch 32: Parking brake operation Detection switch 33: Acceleration and deceleration detector CMU: Control device (control means) Patent applicant Aisin Seiki Co., Ltd.

Claims (11)

[Claims] (1) It is inserted in the pressure transmission line between the brake mask cylinder and the axle brake, and increases the output pressure in response to the increase in input pressure, and increases the input pressure - output pressure in response to the pressure in the control chamber. A proportional control valve that increases the inflection point of the input pressure; A solenoid valve that controls communication and isolation between the input pressure and the control room; A means for detecting vehicle load; A means for detecting human pressure; A proportional control device for a brake, comprising: control means for shutting off a solenoid valve when a predetermined pressure as a parameter is reached. (2) The proportional brake control device according to claim 1, wherein the predetermined pressure is a predetermined pressure determined by the vehicle load and the rising speed of the input pressure. (3) The predetermined pressure is a predetermined pressure determined by the vehicle load, the rate of increase in input pressure, and the deceleration of the vehicle.
The proportional control device for the brake described in item 1). (4) The proportional brake control device according to claim (1), wherein the means for detecting the vehicle load is a pressure detector that detects the pressure of the suspension system. (5) The proportional brake control device according to claim (1), wherein the means for detecting vehicle load is a vehicle height detection device for detecting vehicle height. (6) The control means repeatedly reads the vehicle load when the vehicle is not substantially traveling by referring to the detection state of the state detection means such as a door opening/closing detector, a brake operation detector, and a vehicle running detector; The proportional brake control device according to claim 1, wherein reading of the vehicle load is stopped when the vehicle is substantially running, and a predetermined pressure is determined from the read vehicle load. (7) The control means calculates a correction value from the rate of increase in input pressure in response to a brake operation, and performs proportional control of the brake according to claim (2), which corrects a predetermined pressure corresponding to the vehicle load. Device. (8) The control means determines a first correction value from the rising rate of input pressure in response to the brake operation, determines a second correction value from the vehicle deceleration, and adjusts the first and second correction values to a predetermined pressure corresponding to the vehicle load. 2. A brake proportional control device according to claim (3), wherein the brake proportional control device adds the correction of 2. (9) The solenoid valve is a normally open solenoid valve that closes when energized, and the control device energizes the solenoid valve when the input pressure reaches a predetermined pressure.
Proportional brake control device as described in . (10) The solenoid valve is a normally open type and closed self-holding type solenoid valve that closes when energized and then self-maintains open as long as the input pressure is above a predetermined pressure. The proportional brake control device according to claim 1, wherein when a predetermined pressure is reached, the solenoid valve is energized at least until it self-holds. (11) The vehicle is equipped with a vehicle height adjustment device that automatically maintains the vehicle height at a predetermined value.
) Brake proportional control device as described in item ).