JP2017178156A - Brake control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake control device of a vehicle which can enhance a suppression effect of a phenomenon that a brake operation member is pushed and returned due to an increase of an operation reaction force with respect to the brake operation member which is operated by a driver during the execution of ABS control.SOLUTION: In a situation that ABS control is performed, when a holding valve is valve-closed from first timing t1 up to second timing t2 and so forth, a control device being one embodiment of a brake control device of a vehicle performs valve adjustment control for reducing an opening of a differential pressure control valve more than the case that the holding valve is not valve-closed from the second timing t2 up to fourth timing t4 and so forth.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a braking control device for a vehicle that performs antilock brake control.

  Anti-lock brake control (hereinafter referred to as “ABS control”) secures the braking force applied to the vehicle by decreasing or increasing the WC pressure, which is the hydraulic pressure in the wheel cylinder. However, it is control which suppresses the increase in the lock tendency of a wheel. When such ABS control is performed, as described in Patent Document 1, in the braking device, the holding valve and the pressure reducing valve are operated in a state where the pump is operated. That is, when the WC pressure is decreased, the holding valve is closed and the pressure reducing valve is opened. On the other hand, when increasing the WC pressure, the pressure reducing valve is closed and the opening degree of the holding valve is adjusted.

  During the ABS control, when the pressure reducing valve is opened, the brake fluid in the wheel cylinder flows into the reservoir through the pressure reducing valve. Then, the brake fluid in the reservoir is supplied to the fluid path between the master cylinder and the holding valve by the pump. Therefore, when the holding valve is closed, most of the brake fluid supplied from the pump flows into the master cylinder. In this case, since the MC pressure, which is the hydraulic pressure in the master cylinder, increases, the reaction force against the braking operation member operated by the driver increases, and a phenomenon may occur in which the braking operation member is pushed back.

  Therefore, in the apparatus described in Patent Document 1, the increase gradient of the WC pressure in the wheel cylinder during the ABS control is calculated, and the pump operation is stopped when the increase gradient is equal to or less than a predetermined gradient. . As a result, the supply of the brake fluid from the pump to the fluid path between the master cylinder and the holding valve is stopped, so that the reaction force against the braking operation member operated by the driver increases, and the braking operation member The phenomenon of being pushed back can be suppressed. Such a phenomenon is sometimes referred to as “kickback”.

JP 2001-146154 A

  By the way, if the operation of the pump is stopped during the ABS control, the amount of brake fluid in the reservoir cannot be reduced. Therefore, in the device described in Patent Document 1, when the amount of brake fluid in the reservoir exceeds a predetermined amount, the pump increases regardless of whether the increasing gradient of the WC pressure in the wheel cylinder is equal to or less than the predetermined gradient. Is activated. When the pump is operated in this way, an increase in the MC pressure in the master cylinder cannot be suppressed, and thus an increase in the operation reaction force on the braking operation member cannot be suppressed. Therefore, in the apparatus described in Patent Document 1, the operation reaction force on the braking operation member operated by the driver is increased during the ABS control, and the effect of suppressing the phenomenon in which the braking operation member is pushed back is sufficient. Is hard to say.

  An object of the present invention is to provide a braking control device for a vehicle capable of enhancing the effect of suppressing a phenomenon in which an operation reaction force on a braking operation member operated by a driver increases during ABS control and the braking operation member is pushed back. Is to provide.

  A vehicle braking control apparatus for solving the above-described problems is applied to a master cylinder in which a braking operation member is drivingly connected, and a larger hydraulic pressure is generated internally as the operation amount of the braking operation member is increased. And a hydraulic circuit disposed between the wheel cylinder and the master cylinder that are provided. The hydraulic pressure circuit is provided in a fluid passage that connects the master cylinder and the wheel cylinder, and a differential pressure adjusting valve that reduces the opening when the differential pressure between the master cylinder side and the wheel cylinder side is increased. A holding valve, which is provided in a fluid passage connecting the pressure regulating valve and the wheel cylinder and is closed when the fluid pressure in the wheel cylinder is not increased, is connected to the wheel cylinder through the fluid passage, When the brake fluid in the wheel cylinder is allowed to flow out to the reservoir side, the reservoir is connected to the fluid passage connecting the differential pressure regulating valve via the connecting fluid passage, and the fluid passage connecting the wheel cylinder and the reservoir. And a pump for supplying the brake fluid pumped from the reservoir to the fluid path between the differential pressure adjusting valve and the holding valve. The vehicle braking control device controls an anti-lock brake control (hereinafter referred to as “ABS control”) that controls the braking device to adjust the hydraulic pressure in the wheel cylinder when the braking operation member is operated while the vehicle is running. It is also assumed that the apparatus is provided with an ABS control unit that implements. In this vehicle braking control device, when the ABS is controlled by the ABS controller, when the holding valve is closed, the differential pressure adjusting valve is more effective than when the holding valve is not closed. A differential pressure control unit that performs valve adjustment control to reduce the opening is provided.

  When the holding valve is closed under the situation where the ABS control is being performed, the opening degree of the differential pressure adjusting valve is reduced. Thereby, even if the brake fluid in the reservoir is supplied to the fluid passage between the differential pressure adjusting valve and the holding valve by the operation of the pump, the brake fluid is less likely to flow into the master cylinder from the fluid passage. As a result, an increase in the hydraulic pressure in the master cylinder is suppressed, so that an increase in the operation reaction force on the braking operation member can be suppressed. As a result, an operation reaction force on the braking operation member operated by the driver increases. The phenomenon that the braking operation member is pushed back can be suppressed.

  On the other hand, when the holding valve is not closed, the brake fluid flows out from the fluid path between the differential pressure adjusting valve and the holding valve to the wheel cylinder side via the holding valve. Therefore, compared with the case where the holding valve is closed, the amount of brake fluid flowing out from the fluid passage to the master cylinder side via the differential pressure regulating valve is reduced. Therefore, even if the opening degree of the differential pressure adjustment valve when the holding valve is not closed is larger than the opening degree when the holding valve is closed, the operation reaction force against the braking operation member is greatly increased. do not do.

  By the way, during the ABS control, since the pump is operating, the amount of brake fluid in the reservoir increases as the duration of the state in which the holding valve is not closed and the pressure reducing valve is closed becomes longer. Less. When the brake fluid in the reservoir runs out, the pump draws the brake fluid from the master cylinder and supplies the brake fluid to the fluid path between the differential pressure adjusting valve and the holding valve. In such a situation, since the amount of brake fluid in the master cylinder decreases, the operation reaction force on the braking operation member decreases, and the operation amount of the braking operation member tends to increase.

  Therefore, in the braking control device for a vehicle described above, the differential pressure valve control unit is configured such that, in the valve adjustment control, the longer the duration of the state in which the holding valve is not closed and the pressure reducing valve is closed, the longer the differential pressure regulating valve is. It is preferable to increase the opening. According to this configuration, there is a possibility that the opening degree of the differential pressure adjustment valve is larger than the initial period during the same period at the end of the period in which the holding valve is not opened and the pressure reducing valve is closed. is there. That is, when there is no brake fluid in the reservoir, there is a possibility that the opening of the differential pressure adjusting valve is increased. When this situation is realized, even if the brake fluid in the master cylinder is pumped up by the pump, the opening of the differential pressure adjustment valve is large and the brake fluid is adjusted to adjust the differential pressure. Since it is easy to return to the master cylinder side via the valve, a decrease in the hydraulic pressure in the master cylinder is suppressed. Therefore, it is possible to suppress the occurrence of an event that increases the amount of operation of the braking operation member.

  A plurality of wheel cylinders may be connected to the hydraulic circuit. In this case, the hydraulic pressure circuit is provided with a holding valve and a pressure reducing valve for each wheel cylinder connected to the hydraulic pressure circuit. Thus, when a plurality of holding valves are provided in the hydraulic circuit, each holding valve may be closed during the ABS control, or only one holding valve is closed. Sometimes. When each holding valve is closed, the intermediate hydraulic pressure, which is the liquid pressure in the liquid path between the differential pressure adjusting valve and the holding valve, is higher than when only one holding valve is closed. Prone.

  Therefore, in the braking control device for a vehicle described above, the differential pressure valve control unit is configured such that, in the valve adjustment control, when each holding valve is closed, only one of the holding valves is closed. It is preferable to make the opening degree of the differential pressure regulating valve smaller than when it is. According to this configuration, the opening degree of the differential pressure adjusting valve is reduced as each holding valve is closed and the intermediate hydraulic pressure is likely to increase. Therefore, even if the intermediate fluid pressure in the fluid passage is high, it is difficult for the brake fluid to flow out from the fluid passage to the master cylinder side. As a result, an increase in the hydraulic pressure in the master cylinder is suppressed, and an increase in the reaction force against the braking operation member can be appropriately suppressed. Therefore, even in a braking device in which a plurality of holding valves are provided in one hydraulic circuit, an operation reaction force on the braking operation member operated by the driver is increased during the ABS control, and the braking operation is performed. The phenomenon that the member is pushed back can be suppressed.

The block diagram which shows typically the braking device for motorcycles provided with the control apparatus which is the braking control apparatus of the vehicle of 1st Embodiment. The flowchart explaining the processing routine which the same control apparatus performs. When antilock brake control is performed while the motorcycle is running, (a) is a timing chart showing the transition of the pump operation, and (b) is the transition of the differential pressure command current value for the differential pressure regulating valve. 4 is a timing chart showing the transition of the command current value for the holding valve, and FIG. 4D is a timing chart showing the transition of the hydraulic pressure in the wheel cylinder and the hydraulic pressure in the master cylinder. The block diagram which shows typically a part of vehicle braking device provided with the control apparatus which is the braking control apparatus of the vehicle of 2nd Embodiment. The flowchart explaining the processing routine which the same control apparatus performs. In the case where the vehicle braking control device of another embodiment performs anti-lock brake control, (a) is a timing chart showing the transition of a differential pressure command current value with respect to the differential pressure regulating valve, and (b) is a diagram in the wheel cylinder. The timing chart which shows transition of a hydraulic pressure and the hydraulic pressure in a master cylinder.

(First embodiment)
Hereinafter, an embodiment in which a vehicle braking control device is embodied as a braking control device for a motorcycle will be described with reference to FIGS.

  FIG. 1 shows an example of a braking device 10 for a motorcycle including a control device 50 that is a vehicle braking control device of the present embodiment. As shown in FIG. 1, the braking device 10 includes a first master cylinder 12F to which a driver's right hand first brake lever 11F is drivingly connected, and a driver's left hand second brake lever 11R that is drivingly connected. And a second master cylinder 12R. That is, in the present embodiment, each brake lever 11F, 11R is an example of a “braking operation member” in which the brake cylinders 11F, 11R are drivingly connected to the master cylinders 12F, 12R. The MC pressure Pmc that is the hydraulic pressure of the first master cylinder 12F increases as the operation amount of the first brake lever 11F increases, and the MC pressure Pmc of the second master cylinder 12R increases the operation amount of the second brake lever 11R. It gets higher.

  Further, the brake actuator 20 of the braking device 10 is connected to the first hydraulic circuit 21F disposed between the wheel cylinder 40F and the first master cylinder 12F provided for the front wheel FW and the rear wheel RW. And a second hydraulic circuit 21R disposed between the wheel cylinder 40R and the second master cylinder 12R.

  In each hydraulic circuit 21F, 21R, the fluid path connecting the master cylinders 12F, 12R and the wheel cylinders 40F, 40R operates to adjust the differential pressure between the master cylinders 12F, 12R side and the wheel cylinders 40F, 40R side. Differential pressure regulating valves 22F and 22R are provided. These differential pressure regulating valves 22F and 22R are normally open linear electromagnetic valves, and are configured such that the degree of opening decreases as the input differential pressure command current value Ism increases.

  In each of the hydraulic pressure circuits 21F and 21R, the fluid path connecting the differential pressure regulating valves 22F and 22R and the wheel cylinders 40F and 40R is closed when the WC pressure Pwc in the wheel cylinders 40F and 40R is not increased. Holding valves 23F and 23R, which are normally closed electromagnetic valves, are provided. The hydraulic pressure circuits 21F and 21R are provided with pressure reducing valves 24F and 24R, which are normally closed electromagnetic valves that are opened when the WC pressure Pwc in the wheel cylinders 40F and 40R is reduced. When the pressure reducing valves 24F and 24R are opened, the brake fluid in the wheel cylinders 40F and 40R flows out to the reservoirs 25F and 25R via the pressure reducing valves 24F and 24R. That is, the pressure reducing valves 24F and 24R are arranged in a liquid path that connects the wheel cylinders 40F and 40R and the reservoirs 25F and 25R.

  The hydraulic circuits 21F and 21R are provided with pumps 27F and 27R using the electric motor 26 as a drive source. These pumps 27F and 27R are connected to connection portions 29F and 29R between the differential pressure regulating valves 22F and 22R and the holding valves 23F and 23R through the supply flow paths 28F and 28R. Note that the reservoirs 25F and 25R are connected to the liquid passages on the master cylinders 12F and 12R side of the differential pressure regulating valves 22F and 22R through the master side flow passages 30F and 30R which are examples of the connecting liquid passages. Therefore, the pumps 27F and 27R pump the brake fluid when the brake fluid remains in the reservoirs 25F and 25R, while the brakes in the master cylinders 12F and 12R when the brake fluid does not remain in the reservoirs 25F and 25R. The liquid is pumped through the master side flow paths 30F and 30R. When the differential pressure regulating valves 22F and 22R and the pumps 27F and 27R are operated, the fluid path on the wheel cylinders 40F and 40R side than the differential pressure regulating valves 22F and 22R, and the master than the differential pressure regulating valves 22F and 22R. A differential pressure is generated between the fluid passages on the cylinders 12F and 12R side. In addition, the said differential pressure becomes large, so that the opening degree of the differential pressure regulation valves 22F and 22R is small.

  As shown in FIG. 1, the control device 50 includes a wheel speed sensor 51F that detects a wheel speed VW that is the rotational speed of the front wheel FW, and a wheel speed sensor 51R that detects a wheel speed VW that is the rotational speed of the rear wheel RW. And are electrically connected. The control device 50 calculates the vehicle body speed VS based on the wheel speed VW of at least one of the wheels FW and RW, and calculates the slip amount Slp (= VS−VW) of the wheels FW and RW. . When the anti-lock brake control start condition is satisfied, for example, when the slip amount Slp becomes equal to or greater than the determination slip amount, the control device 50 performs the anti-lock brake control for adjusting the slip amount Slp of the corresponding wheel. It has become. In this specification, anti-lock brake control is abbreviated as “ABS control”.

Next, a processing routine executed by the control device 50 when it is determined that the driver is performing a brake operation will be described with reference to a flowchart shown in FIG.
As shown in FIG. 2, in the present processing routine, the control device 50 determines whether or not the ABS control start condition is satisfied (step S11). When the start condition is not satisfied (step S11: NO), the control device 50 repeatedly executes the determination process of step S11 until the start condition is satisfied. On the other hand, when the start condition is satisfied (step S11: YES), the control device 50 performs ABS control (step S12). In this regard, in the present embodiment, the ABS control that controls the braking device 10 to adjust the WC pressure Pwc in the wheel cylinders 40F and 40R by the control device 50 when the brake operation is performed while the vehicle is running. An example of an “ABS control unit” that implements is configured.

  Here, an example of ABS control will be described. That is, when the target wheel is a wheel that requires adjustment of the WC pressure Pwc by performing the ABS control, the control device 50 determines that the holding valve 23F, when the slip amount Slp of the target wheel is larger than the reference slip amount, The valve 23R is closed and the pressure reducing valves 24F and 24R are opened (decrease mode). Further, when the slip amount Slp of the target wheel is equal to the reference slip amount, the control device 50 closes the holding valves 23F and 23R and the pressure reducing valves 24F and 24R (holding mode). When the slip amount Slp of the target wheel is smaller than the reference slip amount, the control device 50 closes the pressure reducing valves 24F and 24R and gradually increases the opening degree of the holding valves 23F and 23R (increases). mode).

  When the ABS control is performed as described above, the control device 50 determines whether or not the holding valves 23F and 23R for the target wheel are closed (step S13). For example, when the target wheel is the front wheel FW, the control device 50 determines whether or not the holding valve 23F is closed. In this case, the control device 50 can determine that the holding valve 23F is closed when the command current value Ino for the holding valve 23F is equal to or greater than the valve closing current value Inoc. The valve closing current value Inoc is set to a current value that can generate the electromagnetic force necessary for closing the holding valves 23F and 23R by the holding valves 23F and 23R. When the target wheel holding valves 23F and 23R are closed (step S13: YES), the control device 50 sets the differential pressure command current value Ism for the target wheel differential pressure adjusting valves 22F and 22R to the first value. The differential pressure current value Ism1 is 1 (step S14), and the process proceeds to step S18 described later.

  Here, when the holding valves 23F and 23R are closed during the ABS control, a liquid path (hereinafter referred to as “intermediate liquid path”) between the holding valves 23F and 23R and the differential pressure regulating valves 22F and 22R. The brake fluid tends to flow out to the master cylinders 12F and 12R through the differential pressure regulating valves 22F and 22R that are not closed. When the MC pressure Pmc in the master cylinders 12F and 12R increases, the reaction force against the brake levers 11F and 11R increases, and a phenomenon that the brake levers 11F and 11R are pushed back easily occurs. Therefore, in the present embodiment, when the holding valves 23F and 23R are closed and the brake fluid in the intermediate fluid passage cannot be discharged to the wheel cylinders 40F and 40R side, the master cylinder 12F from the intermediate fluid passage. The opening of the differential pressure regulating valves 22F, 22R is made small so that the amount of brake fluid flowing out to the 12R side can be kept within an allowable range. That is, the first differential pressure current value Ism1 is set to a value that can suppress the increase in the operational reaction force on the brake levers 11F and 11R when the holding valves 23F and 23R are closed to an allowable range. Has been.

  On the other hand, if the holding valves 23F and 23R are not closed in step S13 (NO), the control device 50 acquires the duration TM when the holding valves 23F and 23R are not closed. It is determined whether or not the duration time TM is equal to or shorter than the switching determination time TMTH (step S15). When the ABS control is being performed and the holding valves 23F and 23R are not closed, the pressure reducing valves 24F and 24R are closed. Therefore, it can also be said that the duration TM is the duration of the state in which the holding valves 23F and 23R are not closed and the pressure reducing valves 24F and 24R are closed. When the duration time TM is equal to or shorter than the switching determination time TMTH (step S15: YES), the control device 50 sets the differential pressure command current value Ism for the differential pressure regulating valves 22F and 22R for the target wheel to the first difference. The second differential pressure current value Ism2 is smaller than the piezoelectric current value Ism1 (step S16), and the process proceeds to step S18 described later. On the other hand, when the duration TM exceeds the switching determination time TMTH (step S15: NO), the control device 50 sets the differential pressure command current value Ism for the differential pressure regulating valves 22F and 22R for the target wheel to the second value. The third differential pressure current value Ism3 is smaller than the differential pressure current value Ism2 (step S17), and the process proceeds to step S18 described later.

  Here, in the non-valve closing period in which the holding valves 23F and 23R are not closed during the ABS control, the pumps 27F and 27R are operating and the pressure reducing valves 24F and 24R are closed. Therefore, it can be determined that the longer the non-valve closing period, the smaller the amount of brake fluid in the reservoirs 25F, 25R. As described above, when no brake fluid remains in the reservoirs 25F and 25R, the brake fluid in the master cylinders 12F and 12R is pumped by the pumps 27F and 27R. In this case, since the brake fluid in the master cylinders 12F and 12R decreases, the MC pressure Pmc decreases, and the reaction force against the brake levers 11F and 11R may decrease. In this case, although the driver's brake operation force is constant, the brake operation amount may increase.

  Therefore, in this embodiment, the switching determination time TMTH is set to a value that can determine whether or not the brake fluid remains in the reservoirs 25F and 25R based on the duration time TM. In this case, when the duration time TM is equal to or shorter than the switching determination time TMTH, it can be determined that the brake fluid still remains in the reservoirs 25F and 25R. Therefore, the differential pressure command current value Ism (= second differential pressure current value Ism2 ) Is not so small. On the other hand, when the duration TM exceeds the switching determination time TMTH, it can be determined that there is a possibility that no brake fluid remains in the reservoirs 25F and 25R, and therefore the differential pressure command current value Ism (= third differential pressure) The current value Ism3) is reduced. Therefore, in the present embodiment, when the holding valves 23F and 23R are closed under the situation where the ABS control is being performed by the control device 50, than when the holding valves 23F and 23R are not closed. An example of a “differential pressure valve control unit” that performs valve adjustment control to reduce the opening degree of the differential pressure adjusting valves 22F and 22R is configured. Further, when the holding valves 23F and 23R are not closed, the control device 50 increases the opening of the differential pressure adjusting valves 22F and 22R as the duration time TM is longer.

  In step S18, the control device 50 determines whether or not an ABS control end condition is satisfied. An example of the termination condition is that the vehicle is stopped. If the end condition has not yet been satisfied (step S18: NO), the control device 50 proceeds to step S12 described above. On the other hand, when the end condition is satisfied (step S18: YES), the control device 50 ends the present processing routine.

  Next, with reference to the timing chart shown in FIG. 3, the operation when the WC pressure Pwc in the wheel cylinder 40F for the front wheels is adjusted by performing the ABS control will be described together with effects. In addition, the slip amount Slp of the rear wheel RW is increased by the operation of the second brake lever 11R by the driver, and the WC pressure Pwc in the wheel cylinder 40R for the rear wheel may be adjusted by performing the ABS control. However, since the operation and effect in this case are almost the same as the case where the WC pressure Pwc in the wheel cylinder 40F for the front wheels is adjusted by performing the ABS control, the description thereof will be omitted in this specification.

  As shown in FIGS. 3 (a), (b), (c), and (d), the MC pressure Pmc in the first master cylinder 12F and the WC in the wheel cylinder 40F are caused by a brake operation while the motorcycle is running. The ABS control start condition is satisfied at the first timing t1 when the pressure Pwc increases. Then, the pumps 27F and 27R are operated, the holding valve 23F is closed, and the pressure reducing valve 24F is opened, so that the WC pressure Pwc in the wheel cylinder 40F is reduced. Further, when the differential pressure command current value Ism for the differential pressure regulating valve 22F before the start of the ABS control is “0” in this way, for example, during a period from the first timing t1 to the second timing t2. When the holding valve 23F is closed, the differential pressure command current value Ism for the differential pressure regulating valve 22F is set to the first differential pressure current value Ism1.

  Here, when the differential pressure command current value Ism is “0” even when the holding valve 23F is closed, that is, when the differential pressure adjustment valve 22F is fully open, most of the brake fluid discharged from the pump 27F is It flows to the first master cylinder 12F side through the differential pressure regulating valve 22F. Therefore, as indicated by a broken line in FIG. 3D, the MC pressure Pmc in the first master cylinder 12F is gradually increased from the time (for example, the first timing t1) when the holding valve 23F is closed. .

  On the other hand, in this embodiment, the differential pressure DPmc between the liquid path on the first master cylinder 12F side with respect to the differential pressure adjusting valve 22F and the liquid path on the holding valve 23F side with respect to the differential pressure adjusting valve 22F is the differential pressure. When it is smaller than the command differential pressure DPmcTH, which is a differential pressure corresponding to the command current value Ism (= first differential pressure current value Ism1), the MC pressure Pmc in the first master cylinder 12F does not increase. However, when the differential pressure DPmc reaches the command differential pressure DPmcTH, thereafter, the MC pressure Pmc gradually increases so that the differential pressure DPmc is maintained equal to the command differential pressure DPmcTH.

  Then, the closed state of the holding valve 23F is released at the second timing t2, and the opening degree of the holding valve 23F is gradually increased after the second timing t2. At this time, the MC pressure Pmc at the second timing t2 is lower than when the opening of the differential pressure regulating valve 22F is not reduced (indicated by a broken line in FIG. 3D). That is, the increase in the operation reaction force on the first brake lever 11F can be suppressed by the amount by which the increase amount of the MC pressure Pmc in the first master cylinder 12F during the period in which the holding valve 23F is closed decreases. As a result, the operation reaction force with respect to the braking operation member operated by the driver increases, and the phenomenon in which the braking operation member is pushed back can be suppressed.

  In a motorcycle, unlike a general passenger car, a driver may operate a braking operation member with a hand instead of a foot. Further, the amount of brake fluid used in the braking device 10 for motorcycles is smaller than the amount of brake fluid used in the braking device for general passenger cars. Therefore, the increase amount of the operation reaction force on the first brake lever 11F when the holding valve 23F is closed is larger than the increase amount of the operation reaction force in the general passenger car. Feeling that is easy to get worse. In this regard, by adjusting the opening degree of the differential pressure adjusting valve 22F during the ABS control as in the present embodiment, it is possible to suitably suppress the deterioration of the feeling even in a motorcycle.

  In the non-valve closing period after the second timing t2, the opening degree of the holding valve 23F is increased while the pressure reducing valve 24F is closed. At this time, as shown in FIG. 3C, the decrease rate of the command current value Ino with respect to the pressure reducing valve 24F is large at the initial stage of the non-valve closing period, whereas the decrease of the command current value Ino after the initial period. Speed is reduced. In the present embodiment, the hydraulic pressure in the intermediate liquid passage is relatively high because the opening degree of the differential pressure regulating valve 22F is adjusted during the ABS control. Therefore, for example, in the non-valve closing period such as from the second timing t2 to the fourth timing t4, the command current value Ino is corrected according to the fluid pressure in the intermediate liquid passage at the start of the non-valve closing period. Yes.

  Further, in the present embodiment, in the non-valve closing period, the opening degree of the differential pressure adjusting valve 22F is larger than when it is not (that is, when the holding valve 23F is closed). Here, since the holding valve 23F is not closed during the non-valve closing period, the brake fluid flows out from the intermediate liquid passage to the wheel cylinder 40F side through the holding valve 23F. Therefore, the amount of brake outflow from the intermediate liquid passage to the first master cylinder 12F side via the differential pressure regulating valve 22F is smaller than when the holding valve 23F is closed. That is, in the non-valve closing period, the operation reaction force on the first brake lever 11F is less likely to increase than when this is not the case. Therefore, in this non-valve period, even if the differential pressure adjustment valve 22F is increased, the operation reaction force is unlikely to increase.

  Specifically, when the increase in the operation reaction force on the first brake lever 11F can be suppressed without reducing the opening of the differential pressure adjustment valve 22F, the differential pressure adjustment valve 22F is a normally open linear solenoid valve. Therefore, the opening degree is increased by reducing the differential pressure command current value Ism. Therefore, compared with the case where the differential pressure command current value Ism is held at the first differential pressure current value Ism1 even during the non-valve closing period, an increase in power consumption of the brake actuator 20 during the ABS control can be suppressed. . Moreover, the shortening of the period during which a large current flows through the differential pressure adjusting valve 22F can be shortened, so that the shortening of the life of the differential pressure adjusting valve 22F can be suppressed.

  In the non-valve closing period, the pressure reducing valve 24F is closed, while the operations of the pumps 27F and 27R are continued. Therefore, the amount of brake fluid in the reservoir 25F is decreasing. When the brake fluid in the reservoir 25F runs out, the pump 27F draws the brake fluid from the first master cylinder 12F and supplies the brake fluid to the intermediate fluid passage.

  In this regard, in the present embodiment, even if it is the non-valve closing period, when the continuation time TM elapses the switching determination time TMTH, the differential pressure command current value Ism is further increased, for example, after the third timing t3. It is made smaller. In this case, just before the end of the non-valve closing period, the opening degree of the differential pressure adjusting valve 22F is larger than that in the initial period during the same period. Therefore, when there is no brake fluid in the reservoir 25F, the opening of the differential pressure adjustment valve 22F may be large. When such a situation is realized, even if the brake fluid in the first master cylinder 12F is pumped by the pump 27F, the brake fluid is pumped through the differential pressure regulating valve 22F to the first master cylinder 12F. It is easy to return to the side. Therefore, since the decrease in the MC pressure Pmc in the first master cylinder 12F is suppressed, it is possible to suppress the occurrence of an event that increases the operation amount of the first brake lever 11F.

  However, the length of the non-valve closing period varies depending on the degree of change in the slip amount Slp of the front wheel FW. Therefore, when the non-closing period ends at the sixth timing t6 before the continuation time TM passes the switching determination time TMTH as in the non-closing period starting from the fifth timing t5, the non-closing period Then, the differential pressure command current value Ism does not become the third differential pressure current value Ism3.

(Second Embodiment)
Next, a second embodiment in which the vehicle braking control device is embodied as a vehicle braking control device having four wheels will be described with reference to FIGS. 4 and 5. In the following description, parts different from those of the first embodiment will be mainly described, and the same or corresponding member configurations as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. is there.

  FIG. 4 shows a part of a vehicle braking device 110 having four wheels (FL, FR, RL, RR). As shown in FIG. 4, the braking device 110 includes a booster 113 that assists a brake operation force that is an operation force of a brake pedal 111 that is an example of a brake operation member by a driver, and a brake operation force that is assisted by the booster 113. Is input, and an atmospheric pressure reservoir 114 in which brake fluid is stored. Even in this case, the brake pedal 111 is drivingly connected to the master cylinder 112. The brake actuator 120 of the braking device 110 includes two hydraulic circuits 211 and 212. The first hydraulic circuit 211 includes a wheel cylinder 140a for the left front wheel and a wheel cylinder 140d for the right rear wheel. It is arranged between the master cylinder 112. The second hydraulic circuit 212 is disposed between the wheel cylinder for the right front wheel and the wheel cylinder for the left rear wheel, and the master cylinder 112.

  Next, the configuration of the first hydraulic circuit 211 will be described. In FIG. 4, the configuration of the first hydraulic circuit 211 is illustrated, but the configuration of the second hydraulic circuit 212 is substantially the same as that of the first hydraulic circuit 211, and thus the specific configuration thereof is illustrated. The illustration of the configuration is omitted. Therefore, a specific description of the configuration of the second hydraulic circuit 212 is also omitted in this specification.

  As shown in FIG. 4, the first hydraulic circuit 211 has a differential pressure adjusting valve 221 that operates to adjust the differential pressure between the master cylinder 112 side and the wheel cylinders 140a and 140d side. A holding valve 123a that is closed when the WC pressure Pwc in the wheel cylinder 140a is not increased is provided in the fluid path that connects the differential pressure adjusting valve 221 and the wheel cylinder 140a for the left front wheel. In addition, a holding valve 123d that is closed when the WC pressure Pwc in the wheel cylinder 140d is not increased is provided in a liquid path that connects the differential pressure adjusting valve 221 and the wheel cylinder 140d for the right rear wheel. In addition, a pressure reducing valve 124a is provided in the fluid path connecting the wheel cylinder 140a for the left front wheel and the reservoir 251, and a pressure reducing valve 124d is provided in the fluid path connecting the wheel cylinder 140d for the right rear wheel and the reservoir 251. Is provided.

  The first hydraulic pressure circuit 211 is provided with a reservoir 251 into which brake fluid in the wheel cylinders 140a and 140d flows when the pressure reducing valves 124a and 124d are opened. The reservoir 251 is connected to a liquid path that connects the differential pressure regulating valve 221 and the master cylinder 112 via a master-side flow path 301 that is a connected liquid path. Then, by the operation of the pump 271 using the electric motor 261 as a drive source, the brake fluid in the reservoir 251 and the master cylinder 112 is pumped up, and the brake fluid is supplied to the differential pressure adjusting valve 221 via the supply passage 281. Are supplied to a liquid path connecting the holding valves 123a and 123d.

Next, a processing routine executed by the control device 50 when it is determined that the driver is performing a brake operation will be described with reference to a flowchart shown in FIG.
As shown in FIG. 5, in this processing routine, when the ABS control start condition is not satisfied (step S31: NO), the control device 50 repeatedly executes the determination process of step S31 until the start condition is satisfied. To do. On the other hand, when the start condition is satisfied (step S31: YES), the control device 50 performs ABS control (step S32). Then, the control device 50 determines whether or not both holding valves provided in one hydraulic circuit (211 or 212) are closed (step S33). In addition, the control apparatus 50 performs valve adjustment control including the series of processes of steps S33 to S37 for each of the hydraulic circuits 211 and 212.

  That is, when both the holding valves 123a and 123d provided in the first hydraulic circuit 211 are closed, the determination result of step S33 is “YES”. On the other hand, when only one of the holding valves 123a and 123d is closed, and when both the holding valves 123a and 123d are not closed, the determination result of step S33 is “ NO ”. The second hydraulic pressure circuit 212 is provided with a holding valve for the right front wheel and a holding valve for the left rear wheel. If both the holding valves are closed, the determination result of step S33 is shown. Becomes “YES”. On the other hand, when only one of the two holding valves of the second hydraulic circuit 212 is closed, and when both the holding valves are not closed, the determination result of step S33 is “NO”.

  When the determination result in step S33 is “NO”, the control device 50 determines whether only one of the two holding valves provided in one hydraulic circuit (211 or 212) is closed. It is determined whether or not (step S34). That is, when determining with respect to the 1st hydraulic pressure circuit 211, the control apparatus 50 determines whether only one of both the holding valves 123a and 123d of the 1st hydraulic pressure circuit 211 is closed. . Further, when the determination is made on the second hydraulic circuit 212, the control device 50 closes only one of the holding valve for the right front wheel and the holding valve for the left rear wheel in the first hydraulic circuit 211. Determine whether or not

  If the determination result in step S34 is “YES”, the control device 50 sets the differential pressure command current value Ism for the differential pressure regulating valve to the twelfth differential pressure current value Ism12 (step S35). That is, when only one of the two holding valves 123 a and 123 d of the first hydraulic circuit 211 is closed, the control device 50 causes the differential pressure command current to the differential pressure adjustment valve 221 of the first hydraulic circuit 211. The value Ism is set as a twelfth differential pressure current value Ism12. Similarly, when only one of the two holding valves of the second hydraulic circuit 212 is closed, the control device 50 sets the differential pressure command current value Ism for the differential pressure adjustment valve of the second hydraulic circuit 212. The twelfth differential pressure current value Ism12 is assumed. Thereafter, the control device 50 proceeds to step S38, which will be described later.

  On the other hand, when the determination result of step S34 is “NO”, the control device 50 sets the differential pressure command current value Ism for the differential pressure regulating valve to the thirteenth differential pressure current smaller than the twelfth differential pressure current value Ism12. The value Ism13 is set (step S36). That is, when both the holding valves 123a and 123d of the first hydraulic circuit 211 are not closed, the control device 50 sets the differential pressure command current value Ism for the differential pressure adjusting valve 221 of the first hydraulic circuit 211 to the thirteenth. The differential pressure current value Ism13. Similarly, when both the holding valves of the second hydraulic pressure circuit 212 are not closed, the control device 50 sets the differential pressure command current value Ism for the differential pressure regulating valve of the second hydraulic pressure circuit 212 to the thirteenth differential pressure. The current value is Ism13. Thereafter, the control device 50 proceeds to step S38, which will be described later.

  On the other hand, when the determination result of step S33 is “YES”, the control device 50 sets the differential pressure command current value Ism for the differential pressure regulating valve to an eleventh difference greater than the twelfth differential pressure current value Ism12. The piezoelectric current value Ism11 is set (step S37). That is, when both the holding valves 123a and 123d of the first hydraulic circuit 211 are closed, the control device 50 sets the differential pressure command current value Ism for the differential pressure adjustment valve 221 of the first hydraulic circuit 211 to the eleventh. The differential pressure current value Ism11. Similarly, when both the holding valves of the second hydraulic pressure circuit 212 are closed, the control device 50 sets the differential pressure command current value Ism for the differential pressure regulating valve of the second hydraulic pressure circuit 212 to the eleventh differential pressure. The current value is Ism11. Thereafter, the control device 50 moves the process to the next step S38.

  If the ABS control end condition is not yet satisfied in step S38 (NO), the control device 50 proceeds to step S32 described above. On the other hand, when the end condition is satisfied (step S38: YES), the control device 50 ends the present processing routine.

Next, the operation when the ABS control is performed by the driver's brake operation will be described together with effects.
When the slip amount Slp of the left front wheel FL increases during vehicle braking by the driver's braking operation, the WC pressure Pwc in the wheel cylinder 140a for the left front wheel is adjusted by performing the ABS control. When it is not necessary to adjust the WC pressure Pwc in the wheel cylinder 140a for the right rear wheel connected to the first hydraulic circuit 211, the holding valve 123d for the right rear wheel is not closed. When the holding valve 123a is closed, the differential pressure command current value Ism for the differential pressure adjusting valve 221 of the first hydraulic circuit 211 is set to the twelfth differential pressure current value Ism12. As a result, the opening degree of the differential pressure adjusting valve 221 becomes an opening degree corresponding to the twelfth differential pressure current value Ism12, and compared with the case where the differential pressure command current value Ism is “0”, the pressure is discharged from the pump 271. The brake fluid is less likely to flow out to the master cylinder 112 side via the differential pressure adjustment valve 221. As a result, an increase in the MC pressure in the master cylinder 112 is suppressed, and an increase in the operation reaction force against the brake pedal 111 is suppressed. Therefore, the reaction force against the braking operation member operated by the driver is increased, and the phenomenon in which the braking operation member is pushed back can be suppressed.

  On the other hand, when the adjustment of the WC pressure Pwc in the wheel cylinder 140a for the right rear wheel is unnecessary, when the holding valve 123a for the left front wheel is not closed, that is, the opening degree of the holding valve 123a is increased. The differential pressure command current value Ism for the differential pressure regulating valve 221 is set to the thirteenth differential pressure current value Ism13. Thereby, the opening degree of the differential pressure regulating valve 221 becomes larger than when the holding valve 123a is closed. In this case, as the holding valves 123a and 123d are not closed and the duration of the state in which the pressure reducing valves 124a and 124d are closed is longer, the differential pressure command current value Ism is reduced to reduce the differential pressure. The opening degree of the regulating valve 221 may be increased.

  Further, under the situation where the WC pressure Pwc in the wheel cylinder 140a for the left front wheel is adjusted by performing the ABS control as described above, it is also necessary to adjust the WC pressure Pwc in the wheel cylinder 140a for the right rear wheel. Sometimes. In this case, the right rear wheel holding valve 123d and the pressure reducing valve 124d are operated. Then, both the holding valves 123a and 123d of the first hydraulic circuit 211 may be in a closed state. In this case, compared with the case where only one of the holding valves is closed, the liquid pressure in the intermediate liquid passage that is the liquid passage between the differential pressure adjusting valve 221 and the two holding valves 123a and 123d is likely to increase. Brake fluid easily flows into the master cylinder 112 side from the intermediate fluid passage via the differential pressure regulating valve 221.

  Therefore, in the present embodiment, when both the holding valves 123a and 123d of the first hydraulic circuit 211 are closed, the differential pressure command current value is greater than when only one holding valve is closed. Ism is increased and the opening of the differential pressure regulating valve 221 is decreased. As a result, even if the fluid pressure in the intermediate fluid passage is high, an increase in the amount of brake fluid inflow from the intermediate fluid passage to the master cylinder 112 via the differential pressure regulating valve 221 is suppressed. As a result, an increase in the MC pressure Pmc in the master cylinder 112 is suppressed, and an increase in the operation reaction force against the brake pedal 111 can be appropriately suppressed. Therefore, even when a plurality of holding valves are provided in one hydraulic circuit (211 or 212), an operation reaction force to the braking operation member operated by the driver during the ABS control is increased. The phenomenon that the braking operation member is pushed back can be suppressed.

In addition, you may change each said embodiment into another embodiment as follows.
In each of the above embodiments, the third differential pressure current value Ism3 may be equal to “0”. That is, when the duration time TM exceeds the switching determination time TMTH (step S15: NO), the differential pressure regulating valves 22F, 22R, 221 may be fully opened.

  In each of the above embodiments, when the holding valve is not closed, the differential pressure command current value Ism is variably set depending on whether the duration time TM is equal to or shorter than the switching determination time TMTH. In this way, the differential pressure command current value Ism when the holding valve is not closed may be changed. For example, as shown in FIGS. 6A and 6B, when the pressure reducing valve is closed at the 21st timing t21 and the opening degree of the holding valve is started to increase, the differential pressure command is increased as the duration time TM becomes longer. The current value Ism may be gradually decreased, that is, the opening degree of the differential pressure regulating valves 22F, 22R, 221 may be gradually increased. The broken line shown in FIG. 6B shows the transition of the MC pressure Pmc in the master cylinders 12F, 12R, 112 when the differential pressure regulating valves 22F, 22R, 221 are not operated during the ABS control. .

-The opening degree of the differential pressure regulating valves 22F, 22R, 221 when the holding valve to be controlled by the ABS control is not closed may be increased as the opening degree of the holding valve increases. .
When the holding valve is not closed, the differential pressure command current value Ism is set to the current value when the holding valve is closed (that is, the first differential pressure current value Ism1 in the first embodiment). In the second embodiment, it is the twelfth differential pressure current value Ism12).

  In the second embodiment, the differential pressure command current value Ism when both holding valves of one hydraulic circuit are closed is the difference when only one of the holding valves is closed. The pressure command current value Ism may be equal.

  In each of the above embodiments, the differential pressure regulating valves 22F, 22R, 221 may be normally closed linear solenoid valves. In this case, the differential pressure command current value Ism when the holding valve is closed is made smaller than the differential pressure command current value Ism when the holding valve is open. Thereby, the opening degree of the differential pressure regulating valves 22F, 22R, 221 when the holding valve is closed can be made smaller than the opening degree when the holding valve is opened.

  DESCRIPTION OF SYMBOLS 10,110 ... Brake device, 11F, 11R ... Brake lever which is an example of braking operation member, 111 ... Brake pedal which is an example of braking operation member, 12F, 12R, 112 ... Master cylinder, 21F, 21R, 211, 212 ... Fluid pressure circuit, 22F, 22R, 221 ... differential pressure regulating valve, 23F, 23R, 123a, 123d ... holding valve, 24F, 24R, 124a, 124d ... pressure reducing valve, 25F, 25R, 251 ... reservoir, 27F, 27R, 271 ... Pump, 30F, 30R, 301 ... Master side flow path as an example of a connecting fluid path, 40F, 40R, 140a, 140d ... Wheel cylinder, 50 ... Control device (ABS control unit and Differential pressure valve control unit), FW, RW, FL, RR ... front wheels.

Claims (3)

A master cylinder in which a braking operation member is driven and connected, and a larger hydraulic pressure is generated internally as the operation amount of the braking operation member increases;
A hydraulic circuit disposed between a wheel cylinder provided for a vehicle wheel and the master cylinder;
In the hydraulic circuit,
A differential pressure adjusting valve that is provided in a liquid path connecting the master cylinder and the wheel cylinder, and whose opening is reduced when increasing the differential pressure between the master cylinder side and the wheel cylinder side;
A holding valve that is provided in a fluid path connecting the differential pressure regulating valve and the wheel cylinder and is closed when the fluid pressure in the wheel cylinder is not increased;
A reservoir connected to the wheel cylinder through a liquid path, and connected to a liquid path connecting the master cylinder and the differential pressure regulating valve via a connecting liquid path;
A pressure reducing valve that is disposed in a fluid path connecting the wheel cylinder and the reservoir, and is opened when the brake fluid in the wheel cylinder flows out to the reservoir side;
A pump for supplying the brake fluid pumped from the reservoir to a fluid path between the differential pressure adjusting valve and the holding valve; and
Brake control of a vehicle provided with an ABS control unit that performs anti-lock brake control that controls the brake device and adjusts the hydraulic pressure in the wheel cylinder when the brake operation member is operated while the vehicle is running In the device
In the situation where the anti-lock brake control is performed by the ABS control unit, when the holding valve is closed, the opening degree of the differential pressure adjusting valve is larger than when the holding valve is not closed. A braking control device for a vehicle, comprising: a differential pressure valve control unit that performs valve adjustment control for reducing the pressure. In the valve adjustment control, the differential pressure control unit increases the opening of the differential pressure control valve as the duration time of the state in which the holding valve is not closed and the pressure reducing valve is closed is longer. The vehicle braking control device according to claim 1. A plurality of the wheel cylinders are connected to the hydraulic circuit,
In the hydraulic circuit, the holding valve and the pressure reducing valve are provided for each of the wheel cylinders connected to the hydraulic circuit,
In the valve adjustment control, the differential pressure valve control unit is configured such that when each holding valve is closed, the differential pressure is higher than when only one holding valve is closed among the holding valves. The braking control device for a vehicle according to claim 1 or 2, wherein the opening degree of the regulating valve is reduced.

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