Summary of the invention
Consider above-mentioned shortcoming, the purpose of this invention is to provide a kind of braking force control system, even when pressure-modulation valve or transfer valve break down, described braking force control system also can be carried out accurately diagnosis to the failure condition of pressure-modulation valve or transfer valve, so that corresponding to the suitable output hydraulic pressure of brake-pedal travel amount output.
According to a first aspect of the invention, braking force control system comprises:
The hydraulic pressure generation device, this hydraulic pressure generation device comprises: the pump that is used for extracting from reservoir (reservoir) working fluid; With the accumulator that is used to put aside the described working fluid that extracts by described pump;
Pressure-modulation valve, described pressure-modulation valve are used for the hydraulic pressure that path increment is regulated and output provides from described accumulator corresponding to the brake operating parts; With
By output hydraulically operated apply device from pressure-modulation valve output;
Usually close and be arranged on the valve on the hydraulic path, described hydraulic path allows the accumulator side to be communicated with described apply device through the hydraulic pressure input side of described pressure-modulation valve;
Hydraulic pressure value detection device, described hydraulic pressure value detection device are used for detecting the hydraulic pressure value that is fed to described pressure-modulation valve from described accumulator;
Output hydraulic pressure value detection device, described output hydraulic pressure value detection device is used for detecting the value that outputs to the described output hydraulic pressure of described apply device from the hydraulic pressure outgoing side of described pressure-modulation valve;
Be used to detect the path increment detecting device of the path increment of described brake operating parts; With
Control setup, described control setup are used for controlling the opening and closing of described valve according to each value from described hydraulic pressure value detection device, described output hydraulic pressure value detection device and the detection of described path increment detecting device,
Wherein: when definite described pressure-modulation valve has broken down, the described opening of valves that described control setup control is closed usually, so that will output in the described apply device through the described hydraulic pressure input side of described pressure-modulation valve from the hydraulic pressure of described accumulator side output
Wherein: if determine following situation, described control setup determines that described fault appears in described pressure-modulation valve:
Based on the information of relevant detected value from the input of described hydraulic pressure value detection device, be fit to described hydraulic pressure in the scope outputs to described pressure-modulation valve from described accumulator described hydraulic pressure input side;
Information based on relevant detected value from the input of described output hydraulic pressure value detection device, when utilizing the brake operating of described brake operating parts, be lower than reference delivery pressure according to the information of the described path increment of relevant described brake operating from described path increment detecting device input from the value of the described output hydraulic pressure of the described hydraulic pressure outgoing side output of described pressure-modulation valve; With
The value of described output hydraulic pressure and described with reference to the difference between the delivery pressure greater than predetermined value.
Braking force control system according to a first aspect of the invention also comprises: valve, described valve are closed usually and are arranged on and make on the hydraulic path that hydraulic path that described reservoir and the hydraulic pressure outgoing side that makes described pressure-modulation valve be communicated with described apply device is communicated with;
Wherein: when definite described pressure-modulation valve has broken down, the described valve that described control setup control is closed usually is to open, so that through described valve described hydraulic path disposed thereon, to output to the described reservoir from the part of the described output hydraulic pressure of the described hydraulic pressure input side output of described pressure-modulation valve
Wherein: if determine following situation, described control setup determines that described pressure-modulation valve breaks down:
Based on the information of relevant detected value from the input of described hydraulic pressure value detection device, be fit to described hydraulic pressure in the scope outputs to described pressure-modulation valve from described accumulator described hydraulic pressure input side;
Information based on relevant detected value from the input of described output hydraulic pressure value detection device, when utilizing the brake operating of described brake operating parts, be higher than reference delivery pressure according to the information of the described path increment of relevant described brake operating from described path increment detecting device input from the value of the described output hydraulic pressure of the described hydraulic pressure outgoing side output of described pressure-modulation valve; With
The value of described output hydraulic pressure and describedly be higher than predetermined value with reference to the difference between the delivery pressure.
According to a second aspect of the invention, a kind of braking force control system comprises:
The hydraulic pressure generation device, this hydraulic pressure generation device comprises: the pump that is used for extracting from reservoir working fluid; With the accumulator that is used to put aside the described working fluid that extracts by described pump;
Pressure-modulation valve, described pressure-modulation valve is regulated the hydraulic pressure that provides from described accumulator corresponding to the path increment of brake operating parts; With
By output hydraulically operated apply device from pressure-modulation valve output;
Autobrake control selector valve device, described autobrake control selector valve device can switch to current state wherein said apply device at least and be communicated with described pressure-modulation valve, and from the state of described accumulator cut-out; And current state can be switched to wherein said apply device and be communicated with, and the state that cuts off from described pressure-modulation valve with described accumulator;
The hydraulic pressure value detection device, described hydraulic pressure value detection device is used for detecting the value that is fed to the hydraulic pressure of described pressure-modulation valve from described accumulator;
The first output hydraulic pressure value detection device, the described first output hydraulic pressure value detection device is used to detect the value of the described output hydraulic pressure of exporting from the described hydraulic pressure outgoing side of described pressure-modulation valve;
The second output hydraulic pressure value detection device, the described second output hydraulic pressure value detection device is used for the value of the hydraulic pressure of the described apply device of detecting operation;
Be used to detect the path increment detecting device of the path increment of described brake operating parts; With
Control setup, described control setup comprises:
Reference pressure deciding section, described reference pressure deciding section are used for according to the path increment by described path increment detecting device detection, decision predetermined reference delivery pressure; With
The fault determining section, according to the detected value of the described first output hydraulic pressure value detection device, the detected value of the second output hydraulic pressure value detection device and the described interrelation with reference to delivery pressure that is determined by described reference pressure deciding section, described fault determining section is determined fault.
Braking force control system according to a second aspect of the invention also comprises: regenerative cooperative control selector valve device, described regenerative cooperative control selector valve device can switch to current state wherein said apply device at least and be communicated with described pressure-modulation valve, and from the open circuited state of described reservoir; And current state can be switched to wherein said apply device and be communicated with, and the state that cuts off from described pressure-modulation valve with described reservoir.
If determine following situation, described fault determining section is determined described fault:
The described detected value of the described first output hydraulic pressure value detection device described approximately equal with by described reference pressure deciding section decision with reference to delivery pressure; With
The described detected value of the described second output hydraulic pressure value detection device is greater than the described detected value of the described first output hydraulic pressure value detection device and described with reference to delivery pressure by described reference pressure deciding section decision; With
Wherein: described control setup also comprises control part, and when described fault was determined, described control part was controlled described regenerative cooperative control selector valve device, so that reduce to operate the described hydraulic pressure of described apply device.
If determine following situation, described fault determining section is also determined described fault:
The described detected value of the described first output hydraulic pressure value detection device described approximately equal with by described reference pressure deciding section decision with reference to delivery pressure; With
The described detected value of the described second output hydraulic pressure value detection device is less than the described detected value of the described first output hydraulic pressure value detection device and described with reference to delivery pressure by described reference pressure deciding section decision; With
Wherein: when described fault was determined, described control part was controlled described autobrake control selector valve device, so that increase the described hydraulic pressure of the described apply device of operation.
If determine following situation, described fault determining section is also determined described fault:
The described detected value of the described detected value of the described first output hydraulic pressure value detection device and the described second output hydraulic pressure value detection device is approximately equal;
The described described detected value of exporting the hydraulic pressure value detection device with reference to delivery pressure greater than the described detected value and described second of the described first output hydraulic pressure value detection device by described reference pressure deciding section decision; With
Each detected value of described first output hydraulic pressure value detection device and the described second output hydraulic pressure value detection device is in the state that does not increase; With
Wherein: when described fault was determined, described control part was controlled described autobrake control selector valve device, so that increase the described hydraulic pressure of the described apply device of operation.
If determine following situation, described fault determining section is also determined described fault:
The described detected value of the described detected value of the described first output hydraulic pressure value detection device and the described second output hydraulic pressure value detection device is approximately equal; With the described described detected value of exporting the hydraulic pressure value detection device with reference to delivery pressure less than the described detected value and described second of the described first output hydraulic pressure value detection device by described reference pressure deciding section decision; With
The detected value of described device for detecting distance of travel diminish and
Wherein: when described fault was determined, described control part was controlled described regenerative cooperative control selector valve device, so that reduce to operate the described hydraulic pressure of described apply device.
The specific embodiment
Hereinafter with reference to Fig. 1 to 4 embodiments of the invention are described.
Fig. 1 is to show the block diagram of braking force control system according to an embodiment of the invention to Fig. 3.Every figure has shown the sketch map of each braking force control system, comprises the cutaway view of the hydraulic booster of power actuated vehicle configuration.Attention: the parts of second embodiment identical with the parts of first embodiment are by the same numeral indication of first embodiment.
(first embodiment)
Braking force control system 1 mainly comprises: hydraulic power source 10; Pressure-modulation valve 20; Auxiliary hydraulic pressure chamber 61; Master cylinder 50; Wheel braking cylinder 70a, 70b, 71a, 71b; And ECU (electronic control unit) 80.
With reference to Fig. 1, below will each parts of braking force control system 1 be described in detail.
<parts 〉
This hydraulic power source 10 produces the working fluid that is used for wheel braking of predetermined hydraulic pressure.Particularly, hydraulic power source 10 comprises: accumulator 10a; Pressure sensor 10b; DC motor 10c; Hydraulic Pump 10d; And reservoir 10e.This accumulator 10a is with the set pressure savings and keep working fluid.This pressure sensor 10b (being also referred to as " hydraulic pressure value detection device ") detects the hydraulic pressure P1 of the working fluid of savings in accumulator 10a.
This reservoir 10e stores and is in atmospheric working fluid.DC motor 10c drives according to the instruction of ECU80 and stops.When DC motor 10c drives, utilize Hydraulic Pump 10d, working fluid 10a is fed to accumulator 10a.According to the value that pressure sensor 10b detects, ECU 80 sends instruction.
Pressure-modulation valve 20 is constructed as follows: according to the path increment of brake pedal (being also referred to as " brake operating parts ") 30, be adjusted to hydraulic pressure P2 from the hydraulic pressure P1 of the working fluid of accumulator 10a supply.The details of relevant this mechanism will describe afterwards.This pressure-modulation valve 20 comprises: be contained in the valve body 20a in the cylinder 60; Can be along x1 and x2 direction sliding motion pressure control valve core 20b with the open end of sealed valve body 20a; With the spring 20c that promotes pressure control valve core 20b along the x1 direction.These springs 20c is contained among the output chamber 20f that is determined by the end of the inwall of valve body 20a and pressure control valve core 20b.Valve opening 203 through forming on valve 20a, output chamber 20f is communicated with the hydraulic path R5 that leads to auxiliary hydraulic pressure chamber 61 (describing later on).
By holding valve 20a and pressure control valve core 20b, pressure-modulation valve 20 utilizes the inwall of valve body 20a, the inwall of cylinder 60 and the periphery wall of pressure control valve core 20b to determine low-pressure chamber 20e.Low-pressure chamber 20e remains on bar pressure through hydraulic path R2 and reservoir 10e permanent communication and press in it.Valve opening 201 through forming on valve 20a respectively and through hole 204, low-pressure chamber 20e further are communicated with output chamber 20f.
Utilize the inwall of cylinder 60 and the periphery wall of pressure control valve core 20b, pressure-modulation valve 20 has also been determined hyperbaric chamber 20d.Hyperbaric chamber 20d is through hydraulic path R1 and accumulator 10a permanent communication.Hyperbaric chamber 20d is permanent to be kept from the hydraulic pressure P1 of the working fluid of accumulator 10a supply.
Supply valve 20g is fed to output chamber 20f side with hydraulic pressure P1.The hydraulic pressure P2 that via through holes 204, blowoff valve 20h will be exported among the 20f of chamber is discharged into low-pressure chamber 20e side.
In cylinder 60, auxiliary hydraulic pressure chamber 61 is determined by the outer end of the inwall of cylinder 60, valve 20a and the outer surface of first piston 50a (describing later on).Auxiliary hydraulic pressure chamber 61 is communicated with hydraulic path R5, and hydraulic path R5 is communicated with output chamber 20f.
Master cylinder 50 comprises: the first piston 50a and the second piston 50b, and the first piston 50a and the second piston 50b all are slidingly matched to cylinder 60; Face the first master cylinder hydraulic pressure chamber 50e of the recess of first piston 50a; The second master cylinder hydraulic pressure chamber 50f with the recess of facing the second piston 50b.
First master cylinder hydraulic pressure chamber 50e storage promotes first piston 50a and promotes the spring 50c of the second piston 50b to the x2 direction along the x1 direction.The second master cylinder hydraulic pressure chamber 50f holds the spring 50d that promotes the second piston 50b to the x1 direction.
Intercommunicating pore 501 is arranged on the first piston 50a, and this intercommunicating pore 501 is communicated with the hydraulic path R8 that leads to reservoir 10e.Intercommunicating pore 502 is arranged on the second piston 50b, and intercommunicating pore 502 is communicated with the hydraulic path R9 that leads to reservoir 10e.Therefore, as in the state of Fig. 1, when brake pedal 30 did not activated, the first master cylinder hydraulic pressure chamber 50e and the second master cylinder hydraulic pressure chamber 50f were communicated with reservoir 10e.
The first master cylinder hydraulic pressure chamber 50e with lead to wheel braking cylinder 70a, the hydraulic path R4 of 70b is communicated with, and is used for braking force is applied to two trailing wheels.The second master cylinder hydraulic pressure chamber 50f with lead to wheel braking cylinder 71a, the hydraulic path R6 of 71b is communicated with, and is used for braking force is applied to two front-wheels.
Pressure sensor 32 (being also referred to as " output hydraulic detection device ") is arranged on the hydraulic path R5 that is communicated with auxiliary hydraulic pressure chamber 61.The hyperbaric chamber 20d of pressure-modulation valve 20 is communicated with hydraulic path R3, and hydraulic path R3 is provided with electromagnetic valve 34 (closing i.e. Fig. 1, the EV 34 in 2 usually).Through the hydraulic path R7 from hydraulic path R5 branch, the low-pressure chamber 20e of pressure-modulation valve 20 is communicated with hydraulic path R5.Electromagnetic valve 36 (path blockade, i.e. Fig. 1, the EV36 in 2) is arranged on this hydraulic path R7.
Below, the main points of braking force control system 1 will be described at the general operation of braking force control system 1.
The general operation of<braking force control system 1 〉
At first, will the principle of pressure-modulation valve 20 be described.
According to along the power of x1 direction and along the relation between the power of x2 direction, pressure-modulation valve 20 is adjusted to hydraulic pressure P2 with the hydraulic pressure P1 among the 20d of hyperbaric chamber.
Particularly, by balance by the stroke of brake pedal 30 produce along the forward thrust of the pressure control valve core 20b of x2 direction with along the thrust backward of x1 direction, conduct { pressure of output chamber 20f * in the face of the restoring force of area+spring 20c of the pressure control valve core 20b that exports chamber 20f }, obtain hydraulic pressure P2.
Hereinafter with reference to Fig. 2, provide when brake pedal 30 activated the explanation of the operation of relevant braking force control system.
In this case, when pressure control valve core 20b moved to position among Fig. 2 along the position of x2 direction from Fig. 1, output chamber 20f cut off from low-pressure chamber 20e, is communicated with hyperbaric chamber 20d and export chamber 20f then.At this moment, by pedal 30, pressure control valve core 20b is pushed to the x2 direction, and also applies power by hydraulic pressure P2 and spring 20c along the x1 direction.
This motion is closed blowoff valve 20h, and supply valve 20g opens then, so that the hydraulic pressure P1 among the 20d of hyperbaric chamber, is imported into output chamber 20f through supply valve 20g and through hole 204, at output chamber 20f, P1 is adjusted to hydraulic pressure P2's.Through valve opening 203 and hydraulic path R5, the hydraulic pressure P2 after the adjusting is output in the auxiliary hydraulic pressure chamber 61.In the second embodiment of the present invention of Miao Shuing, electromagnetic valve 32 and electromagnetic proportional valve 31 are arranged on this hydraulic path R5 in the back.
In auxiliary hydraulic pressure chamber 61, hydraulic pressure P3 is by producing from output chamber 20f input hydraulic pressure P2, and hydraulic pressure P3 promotes piston 50a along the x2 direction like this.Along with the motion of first piston 50a, the intercommunicating pore 501 of first piston 50a also moves along the x2 direction, so that intercommunicating pore 501 is cut off from the hydraulic path R8 that leads to reservoir 10e.Then, through hydraulic path R4, the hydraulic pressure P4 of the first master cylinder hydraulic pressure chamber 50e is output to wheel braking cylinder 70a, 70b.Thus, braking force is applied on two trailing wheels.
Simultaneously, along with the motion of first piston 50a, the second piston 50b moves along the x2 direction, so that the intercommunicating pore 502 of the second piston 50b cuts off from the hydraulic path R9 that leads to reservoir 10e.Then, through hydraulic path R6, the hydraulic pressure P4 of the second master cylinder hydraulic pressure chamber 50f is output to wheel braking cylinder 71a, 71b.Thus, braking force is applied on two front-wheels.
<pressure-modulation valve 20 breaks down 〉
Situation 1 descends from the P2 that exports chamber 20f
Below will illustrate: break down owing to pressure-modulation valve 20 under the situation about descending at hydraulic pressure P2, how control brake control setup 1 from output chamber 20f.
Suppose: though hydraulic pressure P1 outputs to the 20d of hyperbaric chamber from accumulator 10a with suitable pressure, foreign matter etc. are blocked in the valve opening 203 of valve body 20a.In this case, when brake operating as shown in Figure 2, although the hydraulic pressure P2 that outputs to the auxiliary hydraulic pressure chamber 61 from output chamber 20f considered to be in suitable pressure, serious decline may appear.As a result, hydraulic pressure P2 can not be to export with the cooresponding suitable pressure of the path increment of brake pedal 30.
According to the first embodiment of the present invention, under the hydraulic pressure P2 from pressure-modulation valve 20 output has dropped to situation below the predetermined pressure range, at first, according to the information of relevant pressure from pressure sensor 10b input, ECU 80 determines whether hydraulic pressure P1 output to the hyperbaric chamber 20d of pressure-modulation valve 20 from accumulator 10a with the pressure that is fit to.Next, if ECU 80 is according to the information of relevant pressure from pressure sensor 32 inputs, definite hydraulic pressure P2 from output chamber 20f output descends and is lower than preset range (being also referred to as " detected value "), if and ECU 80 is according to the information of the path increment of relevant brake pedal 30, also determine detected value than current with reference to output hydraulic pressure low predetermined value, then ECU 80 determines to break down at pressure-modulation valve 20.
If determine that pressure-modulation valve 20 breaks down, then ECU 80 sends signal to open its valve to electromagnetic valve 34.At this moment, electromagnetic valve 36 keeps closing.When electromagnetic valve 34 these unblankings of response, hyperbaric chamber 20d is allowed to be communicated with hydraulic path R3.Therefore, through hydraulic path R3 and R5, be output in the auxiliary hydraulic pressure chamber 61 with the hydraulic pressure P1 that outputs to the suitable pressure the 20d of hyperbaric chamber from accumulator 10a.Simultaneously, the hydraulic pressure that is lower than preset range is output in the auxiliary hydraulic pressure chamber 61 also through hydraulic path R5.
Then, information according to relevant pressure from pressure sensor 32 input, the On/Off operation of ECU 80 control electromagnetic valve 34, so that information according to relevant pressure from pressure sensor 41 input, output to and equal current pressure in the auxiliary hydraulic pressure chamber 61, this current information that depends on relevant brake pedal 30 path increments of importing from stroke sensor 51 with reference to output hydraulic pressure value with reference to output hydraulic pressure value.
As mentioned above, if when brake operating, become from the hydraulic pressure P2 of pressure-modulation valve 20 output and to be lower than predetermined pressure range, the operation of electromagnetic valve 34 Be Controlled On/Off, so that output to and equal current pressure in the auxiliary hydraulic pressure chamber 61 with reference to output hydraulic pressure value, this is current to depend on information from the path increment of the relevant brake pedal 30 of stroke sensor 51 inputs with reference to output hydraulic pressure value, thereby can output to the auxiliary hydraulic pressure chamber 61 from hyperbaric chamber 20d side corresponding to the hydraulic pressure of the path increment of brake pedal 30.Correspondingly,, thereby when brake operating, become when being lower than preset range, can guarantee that also the braking force that will be fit to is applied to wheel braking cylinder 70a, 70b, 71a, each of 71b from the hydraulic pressure P2 of pressure-modulation valve 20 outputs even when breaking down.
If when brake operating, become from the hydraulic pressure P2 of pressure-modulation valve 20 output and to be lower than preset range, ECU 80 also can be according to the information of relevant pressure from pressure sensor 32 input, the On/Off operation of control electromagnetic valve 34, so that output to the pressure that is higher than current reference output hydraulic pressure value in the auxiliary hydraulic pressure chamber 61, this current reference output hydraulic pressure value depends on the information about the path increment of the brake pedal of importing from stroke sensor 51 30.In this case,, thereby when brake operating, become when being lower than preset range, can guarantee more that also the braking force that will be fit to is applied to wheel braking cylinder 70a, 70b, 71a, each of 71b from the hydraulic pressure P2 of pressure-modulation valve 20 outputs even when breaking down.
Situation 2: the P2 that exports chamber 20f certainly reduces deficiency
Hereinafter, explanation is reduced under the not enough situation at the hydraulic pressure P2 that exports chamber 20f output certainly, how control brake control setup 1.
Suppose and following fault occurs: when brake operating as shown in Figure 2, though hydraulic pressure P1 outputs to the hyperbaric chamber 20d of pressure-modulation valve 20 with the pressure that is fit to from accumulator 10a, but, therefore hindered the motion of pressure control valve core 20b because for example spring 20c is stuck on the perisporium of output chamber 20f.In this case, because the motion of pressure control valve core 20b is obstructed, therefore can not export the hydraulic pressure that is fit to corresponding to the path increment of brake pedal 30.That is, even the stroke of brake pedal 30 reduces, it is not enough that the returning of pressure control valve core 20b also becomes, thus fully the reducing of the hydraulic pressure can't obtaining from output chamber 20f to auxiliary hydraulic pressure chamber 61.As a result, just can not be with suitable pressure output hydraulic pressure P2 corresponding to the path increment of brake pedal 30.
According to the first embodiment of the present invention, if information based on relevant pressure from pressure sensor 32 input, definite becoming from the value of exporting the hydraulic pressure P2 of chamber 20f exceeds predetermined value than current output reference value, ECU 80 determines to break down from the hydraulic pressure P2 that exports chamber 20f output, and wherein current output reference value depends on the information from the path increment of the relevant brake pedal 30 of stroke sensor 51 inputs.
If as mentioned above, determine that pressure-modulation valve 20 hydraulic pressure occurs and reduces not enough fault, then ECU 80 sends signal to open its valve to electromagnetic valve 36.At this moment, electromagnetic valve 34 keeps closing.When these unblankings of electromagnetic valve 36 response, hyperbaric chamber 20d is allowed to be communicated with reservoir 10e through hydraulic path R5, hydraulic path R7, low-pressure chamber 20e and hydraulic path R2 from hydraulic path R5 branch.Therefore, through hydraulic path R5, hydraulic path R7, low-pressure chamber 20e and hydraulic path R2, export the part that chamber 20f outputs to the hydraulic pressure of hydraulic path R5 certainly and be released among the reservoir 10e from hydraulic path R5 branch.Therefore, just can reduce to export hydraulic pressure among the 20f of chamber.
The On/Off operation of ECU 80 control electromagnetic valve 36, equal current hydraulic pressure in the auxiliary hydraulic pressure chamber 61 so that output to, this current information that depends on the path increment of the relevant brake pedal of importing from stroke sensor 51 30 with reference to output hydraulic pressure value with reference to output hydraulic pressure value.Thereby through hydraulic path R7 side, a part that outputs to the hydraulic pressure of hydraulic path R5 from output chamber 20f is discharged into the reservoir 10e.Correspondingly, the hydraulic pressure that can solve among the output chamber 20f reduces not enough fault.
As mentioned above, if appearring in pressure-modulation valve 20, hydraulic pressure reduces not enough fault, the On/Off operation of ECU 80 control electromagnetic valve 36, equal current pressure in the auxiliary hydraulic pressure chamber 61 so that output to, this current information that depends on the path increment of the relevant brake pedal of importing from stroke sensor 51 30 with reference to output hydraulic pressure value with reference to output hydraulic pressure value.Therefore, can solve hydraulic pressure and reduce not enough fault, and can be output in the auxiliary hydraulic pressure chamber 61 corresponding to the hydraulic pressure that is fit to of the path increment of brake pedal 30.Therefore, even when pressure-modulation valve 20 hydraulic pressure occurs and reduces not enough fault during brake operating, can guarantee that the braking force that will be fit to is applied to wheel braking cylinder 70a, 70b, 71a, each among the 71b.
The On/Off operation of ECU 80 all right control electromagnetic valve 36, be lower than current pressure in the auxiliary hydraulic pressure chamber 61 so that output to, this current information that depends on the path increment of the relevant brake pedal of importing from stroke sensor 51 30 with reference to output hydraulic pressure value with reference to output hydraulic pressure value.In this case, can weaken since in the pressure-modulation valve 20 hydraulic pressure reduce the influence that deficiency causes, and will output in the auxiliary hydraulic pressure chamber 61 corresponding to the hydraulic pressure of the path increment of brake pedal 30.
Second kind of embodiment
Below, with reference to Fig. 3 and Fig. 4 the second embodiment of the present invention is described.
Major part is similar to the braking force control system 1 among first embodiment, and braking force control system 100 mainly comprises: hydraulic power source 10; Pressure-modulation valve 20; Auxiliary hydraulic pressure chamber 61; Master cylinder 50; Wheel braking cylinder 70a, 70b, 71a, 71b; With ECU 80;
With reference to Fig. 3, below will be described in detail braking force control system 100.
<parts 〉
Except electromagnetic valve 34; Electromagnetic valve 32; Electromagnetic proportional valve 31,33; Be used for detecting the pressure sensor 40,41 of each hydraulic pressure in output chamber 20f and the auxiliary hydraulic pressure chamber 61, be similar to identical according to each parts of the braking force control system 100 of second embodiment with the parts of braking force control system 1 among first embodiment.Therefore, only these different parts are specifically described.As shown in Figure 1, like be considered to first embodiment<parts in can see.
At first, will be described electromagnetic valve 34,32 and electromagnetic proportional valve 31,33.
Usually the electromagnetic proportional valve 31 (being also referred to as " first apportioning valve ", i.e. EPV31 among Fig. 3) of electromagnetic valve of opening 32 (being also referred to as " second valve ", i.e. EV among Fig. 3 32) and unlatching usually is arranged on the hydraulic path R5.Boiler check valve 32a and electromagnetic valve 32 are arranged in parallel, so that only allow from the upstream flowing downstream, and boiler check valve 31a also is arranged in parallel with electromagnetic valve 31, so that only allow upstream the flowing from the downstream.
In the downstream of electromagnetic proportional valve 31, hydraulic path R5 is from leading to the hydraulic path R3 branch of hyperbaric chamber 20d.Usually electromagnetic valve closed 34 (being also referred to as " first valve ", i.e. EV in Fig. 3 34) is arranged on this hydraulic path R3.In a second embodiment, these two electromagnetic valves 32,34 have the autobrake controllable function, and hereinafter, comprise that the electromagnetic valve 32,34 of this autobrake controllable function (describing later on) is known as autobrake control selector valve device.
In the downstream of electromagnetic proportional valve 31, hydraulic path R7 is from leading to the hydraulic path R5 branch of low-pressure chamber 20e.The electromagnetic proportional valve 33 of closing usually (being also referred to as " second apportioning valve ", i.e. EPV among Fig. 3 33) is arranged on this hydraulic path R7.In a second embodiment, these two electromagnetic proportional valves 31,33 have regenerative cooperative brake control function (describing afterwards), and hereinafter, comprise that the valve 31,33 of this regenerative cooperative brake control function is known as regenerative cooperative control selector valve device.Attention: by load control (duty control) is provided thereon, electromagnetic proportional valve 31,33 also can be used as electromagnetic valve.
Below will detect among the output chamber 20f and the pressure sensor 40,41 of the pressure in the auxiliary hydraulic pressure chamber 61 is described to being respectively applied for.
Pressure sensor 40 (being also referred to as " the first output hydraulic pressure value detection device ") and pressure sensor 41 (being also referred to as " the second hydraulic pressure value detection device ") are configured so that: pressure sensor 40 detects the hydraulic pressure P2 among the output chamber 20f, and the hydraulic pressure P3 that pressure sensor 41 detects in the auxiliary hydraulic pressure chamber 61.Each of pressure sensor 40,41 outputs to ECU 80 with its detected value.
Stroke sensor 51 detects the path increment of brake pedal 30 and its detected value is outputed to ECU80.
ECU 80 not only has such as the conventional func that sends driving command to DC motor 10c, and as reference pressure determining section 80a, fault determining section 80b and control part 80c.These parts 80a will be described later to the function of 80c.
The general operation of<braking force control system 100 〉
Because the general operation of the braking force control system 100 among second embodiment is identical with the general operation of first embodiment, thus its description will omit in the present embodiment (referring among first embodiment<general operation of braking force control system 1)
The fault of<relevant pressure-modulation valve 20 〉
Situation 1: the decline of exporting the P2 of chamber 20f certainly
Below will be to because the obstruction in the pressure-modulation valve 20 and under the situation about descending from the hydraulic pressure P2 of output chamber 20f output, how control brake control setup 100 describes for example.
In order to solve the decline of exporting the hydraulic pressure P2 of chamber 20f output for above-mentioned reasons certainly, ECU80 control electromagnetic valve 32 is closed and control electromagnetic valve 34 is opened.This control makes the hydraulic pressure P1 among the 20d of hyperbaric chamber be supplied to the auxiliary hydraulic pressure chamber 61 from electromagnetic valve 34 through hydraulic path R3 and R5.In order to keep the hydraulic pressure P3 of this increase, electromagnetic valve 32 and 34 can Be Controlled be closed.
Situation 2: the hydraulic pressure P2 that exports chamber 20f certainly reduces deficiency
Below, will be to occurring reducing under the not enough situation at hydraulic pressure P2 from output chamber 20f output, how control brake control setup 100 describes.This fault is because for example on the accidental perisporium that is stuck in output chamber 20f of spring 20c, hinders pressure control valve core 20b smooth motion and occurs.
Hydraulic pressure P3 reduces deficiency in auxiliary hydraulic pressure chamber 61 in order to solve for above-mentioned reasons, and ECU80 control electromagnetic valve 32 is opened and control electromagnetic valve 34 is closed.
This control makes the hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61 be imported among the output chamber 20f through electromagnetic valve 32, then through blowoff valve 20h to low-pressure chamber 20e side, thereby reduce hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61.
If during the autobrake control operation, depress brake pedal 30, exceed hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61 of autobrake control operation from the hydraulic pressure P2 of pressure-modulation valve 20 output, so that other pressure is through imposing on hydraulic pressure P3 with electromagnetic valve 32 check valve in parallel 32a.
<regenerative cooperative controllable function 〉
Below, will be to describing by the relevant regenerative cooperative controllable function of using electromagnetic proportional valve 31,33.
During operation regenerative cooperative controllable function, for required brakig force distribution precedent such as the regenerative brake power in the elec. vehicle and friction (hydraulic pressure) braking force that will be caused by the stroke of brake pedal 30, ECU 80 provides following control.
In this function, for example, ECU 80 control electromagnetic proportional valves 31 are closed, and 33 unlatchings of control electromagnetic proportional valve, thereby through electromagnetic proportional valve 33, the hydraulic pressure P3 in the hydraulic pressure chamber 61 is discharged in the low-pressure chamber 20e side.Therefore, the hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61 is reduced, can be with the distribution corresponding to the ratiometric friction brake force of regenerative brake power of the ratio control of expectation thereby make.
Attention: if carry out regenerative brake control in the initial period that depresses brake pedal 30, by control electromagnetic proportional valve 31, the hydraulic pressure that flows into the auxiliary hydraulic pressure chamber 61 from output chamber 20f can cut off or reduce.This means: if the path increment of brake pedal 30 is reduced during the regenerative brake control operation, and during the regenerative brake control operation, hydraulic pressure P2 from pressure-modulation valve 20 outputs becomes less than the hydraulic pressure P3 of auxiliary hydraulic pressure chamber 61, the boiler check valve 31a by being arranged in parallel with electromagnetic proportional valve 31 then, hydraulic pressure P3 reduces.
Below, will the typical performance of the ECU 80 of braking force control system 100 be described.
Fig. 4 has shown a series of treatment step of ECU 80.To describe the situation of suitable detected value below from pressure sensor 40,41 and stroke sensor 51 input ECU 80.
More specifically, ECU 80 receives the detected value of the hydraulic pressure P2 among the output chamber 20f and the detected value of the hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61.ECU 80 also receives the detected value of indication as the path increment of the brake pedal 30 of the operational ton of brake pedal 30.
Then, according to the detected value of stroke sensor 51, the reference pressure deciding section 80a of ECU 80 decision reference pressure value.In hydraulic power source 10 normal operation and under the suitable hydraulic pressure savings situation in accumulator 10a, this decision depends on that predetermined detection value and oneself export the relation between the hydraulic pressure of chamber 20f.
In this case, according to the hydraulic pressure P2 that indicates in the detected value of pressure sensor 40, the hydraulic pressure P3 that indicates in the detected value of pressure sensor 41 and the interrelation of reference pressure, the fault determining section 80b of ECU 80 determines whether only hydraulic pressure P3 excessive (S1).Here " only hydraulic pressure P3 is excessive " representative: hydraulic pressure P2 and reference pressure are approximately equal, and hydraulic pressure P3 is bigger than these two values.
Whether about the judgement of " P2 and reference pressure are approximately equal " or " P3 is greater than them " can use threshold value to carry out.For example, if the difference between hydraulic pressure P2 and the reference pressure less than threshold value, determines to belong to " P2 and reference pressure are approximately equal ".If poor between P2 and the P3, and the difference between reference pressure and the P3 all is equal to or greater than threshold value, determines to belong to " P3 is greater than these two values ".
If determine it is " only P3 is excessive " (in "Yes" of S1), fault determining section 80b determines that fault is to block (S2) in electromagnetic valve 34 leakages or the electromagnetic valve 32, proceeds to S3 then.
At S3, by control electromagnetic proportional valve 33, the control part 80c of ECU 80 carries out the FS operation to reduce hydraulic pressure P3.Attention: FS is the abbreviation of " fail safe ".Or rather, electromagnetic proportional valve 33 Be Controlled are opened.Therefore, through electromagnetic proportional valve 33, low-pressure chamber 20e, the working fluid in the auxiliary hydraulic pressure chamber 61 is discharged among the reservoir 20e, thereby the hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61 is reduced.
Otherwise at the S1 place, if ECU 80 determines it is not P3 excessive (in the "No" of S1) only, according to the relation of above-mentioned P2, P3 and reference pressure, fault determining section 80b determines whether that only P3 is too little.Here " only P3 is too little " refers to that hydraulic pressure P2 is approximate identical with reference pressure, and hydraulic pressure P3 is littler than these two values.
The determining of " P2 is approximately equal with reference pressure " about whether with identical at S1, and relevant whether the definite of " P3 is less than them " can use threshold value to determine.For example, if poor between P2 and the P3, and the difference between reference pressure and the P3 would belong to " P3 is less than these two values " all less than threshold value.
If determine " only P3 is too little " (in "Yes" of S4), fault determining section 80b determines that fault is to block (S5) in electromagnetic proportional valve 33 leakages or the electromagnetic proportional valve 31, proceeds to S6 then.
At S6, by control electromagnetic valve 34, fault determining section 80b carries out the FS action so that other pressure is applied to hydraulic pressure P3.Particularly, electromagnetic valve 34 Be Controlled are opened, thereby the working fluid among the 20d of hyperbaric chamber is supplied in the auxiliary hydraulic pressure chamber 61 through electromagnetic valve 34, are applied to hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61 with other pressure.
Otherwise to the judgement of S4, if judge it is not P3 too little (in the "No" of S4) only, then fault determining section 80b proceeds to S11, so that according to above-mentioned three's interrelation, determine whether that only reference pressure is excessive, that is, only the stroke of brake pedal 30 is excessive.Here " only reference pressure is excessive " refers to that P2 and P3 are approximately equal, and reference pressure is greater than these two values.In this case, by using threshold value to carry out this judgement.
If determine it is " only the stroke of brake pedal 30 is excessive " (in "Yes" of S7), fault determining section 80b proceeds to S8 so that determine whether P2 and P3 is in the situation that they do not rise.If they do not rise fault determining section 80b judgement (in the "Yes" of S8), then it proceeds to S9.
At S9, fault determining section 80b determines that fault is to block among the supply valve 20g, proceeds to S10 then.
At S10, by control electromagnetic valve 34, control part 80c carries out the FS action to apply other pressure to hydraulic pressure P3.Particularly, electromagnetic valve 34 Be Controlled are opened, thereby the working fluid among the 20d of hyperbaric chamber is supplied in the auxiliary hydraulic pressure chamber 61 through electromagnetic valve 34.Therefore, other pressure (further pressure) is applied to the hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61.
On the other hand, for determining of S7, if determine the only stroke excessive (in the "No" of S7) of brake pedal 30, fault determining section 80b proceeds to S11, so that according to above-mentioned three's interrelation, determine whether that only the stroke of brake pedal 30 is too little.Here " stroke that is not only brake pedal 30 is too little " refers to that P2 and P3 are approximately equal, and reference pressure is less than these two values.In this case, by using threshold value to carry out this judgement.
If determine it is " only the stroke of brake pedal 30 is too little " (in "Yes" of S11), fault determining section 80b proceeds to S12, and determines whether to exist stroke (variation that reduces).In this step, if the detected value of relevant stroke sensor 51 is not " 0 ", fault determining section 80b determines to exist stroke.
If determine " having stroke " (in "Yes" of S12), fault determining section 80b proceeds to S13, and definite fault is to block among the blowoff valve 20h, proceeds to S14 then.
At S14, open by control electromagnetic proportional valve 33, the fault determining section 80b of ECU 80 carries out the FS action to reduce hydraulic pressure P3.Therefore, through electromagnetic valve 33, the working fluid in the auxiliary hydraulic pressure chamber 61 is discharged into low-pressure chamber 20e side, so that the hydraulic pressure P3 in the auxiliary hydraulic pressure chamber 61 is reduced.
For example, if according to above-mentioned three's interrelation, determine it is " only P2 is excessive ", fault determining section 80b determines that pressure sensor 40 breaks down.
As mentioned above, the pressure-modulation valve 20 of ECU 80 diagnosis such as supply valve 20g, there are the possibility of fault in electromagnetic valve 32,34 or electromagnetic proportional valve 31,33, and according to diagnostic result, by the suitable operation of FS action execution to fault is provided.
Attention: the present invention is not limited to above-mentioned specific embodiment, and under the situation that does not deviate from the claim scope and spirit of determining of the present invention, can carry out various modifications to the structure according to the braking force control system of the embodiment of the invention.For example, though above-mentioned explanation has shown the example that wherein disposes master cylinder 50, do not use master cylinder 50, hydraulic pressure P2 can be applied directly to wheel braking cylinder 70a, 70b, and 71a is on each of 71b.
The sensor that is used to the foot-operated power on the brake pedal 30 that detects can be provided with together with stroke sensor 51.
When at S2, S5, when S9 or S13 determined fault, fault determining section 80b also can output to this result far read out instrument (not shown).The possibility of this permission chaufeur check boost function inefficacy etc.Stroke sensor 51 can have dual-use function to carry out selfdiagnosis to determine its " normally " or " unusually ".In this case, S8 and S12 can be left in the basket.
By other pressure being applied to the hydraulic pressure P2 of self-hydraulic control cock 20 outputs, the autobrake controllable function can increase the hydraulic pressure P3 of wheel braking cylinder side (auxiliary hydraulic pressure chamber 61).Therefore, this function can be used for increasing usually the control by the fixing multiplication of voltage ratio of the structure of pressure-modulation valve 20, or braking aux. controls when being used for promptly stepping on brake pedal 30.
Braking force control system is described as their examples of being configured on the vehicle wherein according to an embodiment of the invention, but they also may be applied on other mobile object such as aircraft.
If pressure-modulation valve breaks down, the invention provides the accurate diagnosis of failure condition so that carry out suitable operation to fault.Therefore, even when brake operating, becoming from the output hydraulic pressure of pressure-modulation valve is lower than preset range, even or can not reduce fully from the output hydraulic pressure of pressure-modulation valve, also can export suitable output hydraulic pressure corresponding to the path increment of brake pedal.