JP2006029484A - Control apparatus for vehicle operating liquid accumulating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive vehicle operating liquid accumulating device, wherein an accumulator which accumulates operating liquid discharged from a hydraulic pump is reliably shifted from a non-operated condition into an operated condition in which operating liquid accumulating function is developed, right after starting energization of an ECU which controls the hydraulic pump. <P>SOLUTION: This control apparatus initially controls the hydraulic pump to be certainly driven over at least a preset initial time after an ignition switch is changed into an ON-state, independently of accumulator hydraulic pressure Pac. Thus, the accumulator is reliably shifted from the non-operated condition into the operated condition even when fixation occurs in a partition member which partitions the accumulator into a gas chamber and an operating liquid chamber. After finishing the initial control, normal control is executed to keep the accumulator hydraulic pressure Pac between lower limit pressure Pon and upper limit pressure Poff in accordance with a signal only from an inexpensive pressure switch PS which selectively generates signals corresponding to the accumulator hydraulic pressure Pac whether the lower limit pressure Pon or higher or not. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention controls a hydraulic fluid storage device for a vehicle that includes a hydraulic pump that discharges hydraulic fluid to a hydraulic circuit and an accumulator that accumulates hydraulic fluid discharged to the hydraulic circuit by the operation of the hydraulic pump. The present invention relates to a control device.

  This type of hydraulic fluid storage device stores high-pressure brake fluid (hydraulic fluid) required by a vehicle hydraulic actuator used in, for example, a brake hydraulic pressure control device that controls the brake hydraulic pressure of the vehicle. Widely used.

  In general, an accumulator used in such a hydraulic fluid storage device includes a shell that forms a pressure space, and a partition member (movable member) that partitions the pressure space into a gas chamber and a hydraulic fluid chamber. As this type of accumulator, various accumulators such as a bladder type accumulator, a piston type accumulator, and a bellows type accumulator are known depending on the type of the partition member.

  A gas having a predetermined pressure (hereinafter referred to as “gas filling pressure”) is sealed in advance in the gas chamber of the accumulator. Therefore, when the pressure in the hydraulic circuit, that is, the pressure in the hydraulic fluid chamber (hereinafter referred to as “accumulator hydraulic pressure”) is equal to or lower than the gas filling pressure, the partition member is changed even if the accumulator hydraulic pressure changes. Is maintained at the position at the time of gas filling (the position at which the volume of the hydraulic fluid chamber is minimized, hereinafter referred to as “original position”). In this state, such an accumulator cannot exhibit the function of accumulating hydraulic fluid. Hereinafter, this state is referred to as an “inactive state”.

  On the other hand, when the accumulator hydraulic pressure becomes larger than the gas charging pressure (a pressure slightly higher than the gas charging pressure depending on the structure of the accumulator), the partition member moves away from the original position, and the pressure in the gas chamber becomes the accumulator hydraulic pressure. It moves (deforms) in the pressure space according to the change in the accumulator hydraulic pressure so as to be equal. In other words, the amount of hydraulic fluid in the hydraulic circuit increases as the accumulator hydraulic pressure increases. As a result, the accumulator exhibits a function of accumulating hydraulic fluid. Hereinafter, this state is referred to as an “operating state”.

  Therefore, in order to maintain the hydraulic fluid accumulation function of the accumulator having the above-described configuration (and hence to maintain the accumulator in the operating state), it is necessary to maintain at least the accumulator hydraulic pressure at a pressure higher than the gas charging pressure. For this reason, in general, the hydraulic pump used in the hydraulic fluid storage device is configured to drive and control the hydraulic pump (specifically, the motor that drives the hydraulic pump) when the ignition switch of the vehicle is in the ON state. In the state where the ECU is energized), it is driven when the accumulator hydraulic pressure becomes less than a predetermined lower limit pressure greater than the gas filling pressure, and the accumulator hydraulic pressure exceeds a predetermined upper limit pressure greater than the lower limit pressure. Sometimes it can be stopped. The upper limit pressure and the lower limit pressure are determined according to the request on the hydraulic actuator side.

  As a result, the accumulator hydraulic pressure raised to the upper limit pressure decreases due to supply of hydraulic fluid to the hydraulic actuator, leakage of hydraulic fluid in the hydraulic circuit, and the like. When the accumulator hydraulic pressure decreases to the lower limit pressure, the hydraulic pump is driven to increase the accumulator hydraulic pressure to the upper limit pressure again.

  From the above, when the ignition switch of the vehicle is in the ON state, the accumulator hydraulic pressure is maintained at a pressure between the lower limit pressure and the upper limit pressure, and the accumulator is maintained in the operating state. ing.

  By the way, for example, when the ignition switch of the vehicle is maintained in the OFF state for a long time (therefore, the hydraulic pump is stopped for a long time), the accumulator hydraulic pressure is higher than the gas filling pressure. The accumulator having the above configuration is maintained in a non-operating state for a long time by being maintained at a low pressure. In other words, the partition member is fixed at the original position for a long time.

  In this case, the partition member may adhere to the shell (or the fixing member on the shell side) in the original position. This is inevitably interposed between the partition member and the shell (or the fixing member on the shell side) for the purpose of separating the gas chamber and the hydraulic fluid chamber in the accumulator having the above-described configuration. This is mainly due to sticking occurring on the sealing surface of the sealing member.

  Hereinafter, a case will be considered in which the ignition switch of the vehicle is changed from the OFF state to the ON state in a state where the partition member is fixed. In this case, since the accumulator hydraulic pressure is lower than the lower limit pressure (for example, a low pressure in the vicinity of atmospheric pressure), the hydraulic pump is immediately driven.

  Here, when the partition member is maintained at the original position, the volume of the hydraulic fluid in the hydraulic circuit cannot substantially expand. Furthermore, the bulk modulus of hydraulic fluid (for example, brake fluid) is a fairly high value. Accordingly, when the hydraulic pump is driven as long as the partition member is fixed in place, the pressure in the hydraulic circuit (that is, the accumulator hydraulic pressure) increases rapidly. In other words, the increasing gradient of the accumulator hydraulic pressure is a very large value.

  At this time, if the degree of fixation of the partition member is considerably large and the fixation is not canceled until the accumulator hydraulic pressure reaches a certain pressure exceeding the upper limit pressure, when the accumulator hydraulic pressure reaches the upper limit pressure, There may occur a situation in which the hydraulic pump is stopped while the fixing of the partition member is not eliminated (that is, the accumulator is in an inoperative state).

  In this case, the same situation repeatedly occurs each time the hydraulic pump is driven by the accumulator hydraulic pressure being lowered to the lower limit pressure thereafter. That is, after the ignition of the vehicle is changed from the OFF state to the ON state, the accumulator is continuously maintained in the non-operating state, so that the hydraulic fluid is not accumulated in the accumulator. Accordingly, there arises a problem that the hydraulic fluid accumulation function of the accumulator cannot be exhibited.

In order to cope with such a problem, the hydraulic fluid storage device (vehicle auxiliary hydraulic pressure source device) described in Patent Document 1 includes a pressure sensor that can constantly monitor the change of the accumulator hydraulic pressure every time, and the ignition switch is OFF. Only when the hydraulic pump is driven for the first time immediately after being changed from the state to the ON state, if the increasing gradient of the accumulator hydraulic pressure exceeds a predetermined value, the hydraulic pressure does not exceed the above upper limit pressure. The drive of the pump is further continued for a predetermined time. As a result, the accumulator hydraulic pressure can be increased to a pressure at which the fixing of the partition member larger than the upper limit pressure is eliminated, and the partition member can be fixed (the accumulator is changed from the non-operating state to the operating state). Can migrate).
JP 2002-187541 A

  However, the apparatus described in the above document requires an expensive pressure sensor that can constantly monitor the change of the accumulator hydraulic pressure every time in order to detect the increasing gradient of the accumulator hydraulic pressure. Therefore, there is a problem that the manufacturing cost of the entire apparatus increases.

  The present invention has been made to cope with the above-described problems. For example, immediately after the ignition switch of the vehicle is changed from the OFF state to the ON state, the control means for controlling the hydraulic pump is energized. It is an object of the present invention to provide a control device for controlling an inexpensive hydraulic fluid storage device capable of reliably shifting an accumulator from a non-operating state to an operating state immediately after changing from a non-operating state to an energized state. .

  The control device of the hydraulic fluid storage device according to the present invention includes a hydraulic pump that discharges the hydraulic fluid to the hydraulic circuit, an accumulator that stores the hydraulic fluid discharged to the hydraulic circuit by the operation of the hydraulic pump, The present invention is applied to a hydraulic fluid storage device for a vehicle including hydraulic pressure signal generating means for generating a signal related to an accumulator hydraulic pressure which is a pressure of the hydraulic fluid stored in the accumulator.

  Here, the accumulator may be an accumulator provided with a partition member (for example, a piston, a bellows, etc.) that partitions a hydraulic fluid chamber communicated with a hydraulic circuit and a gas chamber filled with gas, Provided with a partition member (for example, a piston or the like) that partitions the hydraulic fluid chamber communicated with the hydraulic circuit and the open air chamber open to the atmosphere, and constantly biases the partition member in the direction of decreasing the volume of the hydraulic fluid chamber The accumulator may be provided with an elastic member (for example, a coil spring or the like) that generates an urging force.

  When the control device for the hydraulic fluid storage device according to the present invention determines that the accumulator fluid pressure is less than a predetermined lower limit pressure based on a signal related to the accumulator fluid pressure in the energized state, Executes normal control to drive the hydraulic pump and stop the hydraulic pump when it is determined that the accumulator hydraulic pressure exceeds a predetermined upper limit pressure that is greater than the lower limit pressure based on a signal related to the accumulator hydraulic pressure The control means (microcomputer, ECU, etc.) to perform is provided.

  Further, the control means includes the hydraulic pressure regardless of the accumulator hydraulic pressure within the initial time for a predetermined initial time after the time when the control means changes from the non-energized state to the energized state. The initial control for driving the pump is executed instead of the normal control.

  Here, the state in which the control means (microcomputer, ECU, etc. that controls driving of the hydraulic pump) is not energized corresponds to, for example, the case where the ignition switch of the vehicle is in the OFF state, and the control means is energized. For example, the state where the vehicle is on corresponds to the case where the ignition switch of the vehicle is in the ON state. Therefore, the “time when the control means changes from the non-energized state to the energized state” (hereinafter referred to as “the energization start time”) is, for example, that the ignition switch of the vehicle is changed from the OFF state to the ON state. Corresponds to the point of change.

  In addition, “to drive the hydraulic pump regardless of the accumulator hydraulic pressure within the initial time period” includes determining whether the accumulator hydraulic pressure is less than the lower limit pressure within the initial time period, and determining whether the accumulator hydraulic pressure is greater than the upper limit. This includes not only the case where the hydraulic pump is always driven without determining whether the pressure is higher than the pressure, but also the case where the above determination is made within the initial time but the hydraulic pump is always driven regardless of the result of the determination. It is.

  According to this, the hydraulic pump is always driven as an initial control for at least a predetermined initial time after the start of energization. Therefore, for example, when the partition member of the accumulator is fixed at the original position (position where the volume of the hydraulic fluid chamber is minimized), the initial time rapidly increases as the hydraulic pump is driven as described above. More than the time (actually, a very short time) required for the accumulator hydraulic pressure to reach a large pressure (at least a pressure greater than the above-mentioned upper limit pressure) that can surely eliminate the sticking of the partition member from “0”. If the time is set to a long time, the partition member can be reliably fixed before the initial time elapses.

  Further, in the normal control that is started from the time when the initial time has elapsed and the initial control is completed, the determination result of whether or not the accumulator hydraulic pressure is less than the lower limit pressure, and the accumulator hydraulic pressure is higher than the upper limit. The drive / stop of the hydraulic pump is controlled based on the determination result of whether or not the pressure is higher than the pressure.

  Therefore, when performing such normal control, it is not necessary to use an expensive pressure sensor capable of constantly monitoring the change in accumulator hydraulic pressure as the hydraulic pressure signal generating means, and whether the pressure is equal to or higher than the set pressure. An inexpensive pressure switch that selectively generates a signal corresponding to whether or not can be used.

  From the above, according to the present invention, immediately after the start of energization, a control device (liquid control device) that controls an inexpensive hydraulic fluid storage device that can reliably move the accumulator from the non-operating state to the operating state. A microcomputer, ECU, etc. for driving and controlling the pressure pump can be provided.

  In this case, the hydraulic fluid storage device of the vehicle further includes a relief valve that opens when the accumulator hydraulic pressure exceeds a predetermined relief pressure greater than the upper limit pressure to release the hydraulic fluid in the hydraulic pressure circuit. The control means includes a time required for the accumulator hydraulic pressure to reach the relief pressure from the upper limit pressure by the operation of the hydraulic pump (when the accumulator is in operation) as the initial time. It is preferred to be configured to use a preset time that does not exceed (and is longer than the very short time).

  In general, in order to protect the hydraulic circuit, the relief valve is often provided in the hydraulic circuit. Operating the relief valve leads to generation of noise and wasteful consumption of energy of the high-pressure hydraulic fluid. Therefore, it is preferable to control the hydraulic pump so that the relief valve is not operated as much as possible.

  On the other hand, since the accumulator hydraulic pressure is maintained at a pressure between the lower limit pressure and the upper limit pressure during the normal control, the accumulator hydraulic pressure at the start of energization is lower than the upper limit pressure. Conceivable.

  From the above, the initial time does not exceed the time required for the accumulator hydraulic pressure to reach the relief pressure from the upper limit pressure by the operation of the hydraulic pump (when the accumulator is in operation) as in the above configuration. By setting the time, it can be avoided that the accumulator hydraulic pressure reaches the relief pressure before the initial time elapses, and therefore the relief valve can be prevented from operating during the initial control.

  In the control device for a hydraulic fluid storage device according to the present invention, the control means is configured such that the accumulator hydraulic pressure becomes equal to or higher than the lower limit pressure based on a signal related to the accumulator hydraulic pressure when the initial time has elapsed. It is preferable that the hydraulic pump is configured to stop at the same time when it is determined that the hydraulic pump is present.

  The lower limit pressure and the upper limit pressure are determined in accordance with a request on the side of a hydraulic actuator (for example, a hydraulic pressure booster of a brake hydraulic pressure control device) that consumes high-pressure hydraulic fluid accumulated in the accumulator. That is, that the accumulator hydraulic pressure is equal to or higher than the lower limit pressure means that the demand on the hydraulic actuator side is satisfied.

  Therefore, as in the above configuration, when the initial time has elapsed and the initial control has been completed, when the accumulator hydraulic pressure is equal to or higher than the lower limit pressure, the hydraulic pump is stopped at the same point. By doing so, it is possible to ensure the accumulator hydraulic pressure that satisfies the requirements on the hydraulic actuator side without unnecessarily continuing the driving of the hydraulic pump (and thus without consuming energy unnecessarily).

  If the accumulator hydraulic pressure is less than the lower limit at the time when the initial time has elapsed, the hydraulic pump continues to be driven according to the normal control that starts after the same point, and the accumulator hydraulic pressure reaches the upper limit. At this point, the hydraulic pump is stopped.

  In the control device for the hydraulic fluid storage device according to the present invention, the hydraulic pressure signal generating means selectively generates a signal corresponding to whether or not the accumulator hydraulic pressure is equal to or higher than the lower limit pressure. The control means includes a side pressure switch, and the control means (when the accumulator is in operation) requires the accumulator hydraulic pressure to reach the upper limit pressure from the lower limit pressure by the operation of the hydraulic pump. Further, a storage means for storing time as a normal pump operating time in advance is provided, and a signal generated by the lower limit side pressure switch when executing the normal control indicates that the accumulator hydraulic pressure is less than the lower limit pressure. The accumulator fluid pressure is less than the lower limit pressure, and the accumulator fluid pressure is less than the lower limit pressure. The determined point on, the stored normal pump operation time the accumulator pressure when the elapsed said is preferably configured to determine that a limit on the pressure or.

  According to this, when the normal control is executed, when the signal generated by the lower limit pressure switch becomes a signal indicating that the accumulator hydraulic pressure is less than the lower limit pressure (that is, the accumulator hydraulic pressure is lower than the lower limit pressure). When the signal indicating the above is changed to a signal indicating that the pressure is less than the lower limit pressure), the hydraulic pump is driven, and thereafter, when the “normal pump operation time” has elapsed, the hydraulic pump is stopped. Thereby, the accumulator hydraulic pressure can be controlled to a pressure between the lower limit pressure and the upper limit pressure.

  In other words, normal control can be achieved only by a signal generated by the lower limit side pressure switch. Accordingly, the upper limit pressure switch that selectively generates a signal corresponding to whether or not the accumulator hydraulic pressure is equal to or higher than the upper limit pressure can be omitted, and the control device for the hydraulic fluid storage device according to the present invention is applied. The hydraulic fluid storage device can be made even cheaper.

  Thus, when the hydraulic pressure signal generating means is composed of only the lower limit side pressure switch, the control means is configured such that the signal generated by the lower limit side pressure switch when the initial time elapses indicates that the accumulator hydraulic pressure is the lower limit pressure. It is preferable that the hydraulic pump is stopped at the same time when the signal indicates that the pressure is higher than the pressure.

  According to this, as described above, the accumulator hydraulic pressure that meets the requirements on the hydraulic actuator side is ensured without unnecessarily continuing the driving of the hydraulic pump (and thus without consuming unnecessary energy). be able to.

  Further, in the case where the hydraulic pressure signal generating means is composed of only the lower limit side pressure switch, the signal generated by the lower limit side pressure switch when the initial time has elapsed is that the accumulator hydraulic pressure is less than the lower limit pressure. The control means continues to drive the hydraulic pressure pump as the initial control after the simultaneous point, and the signal generated by the lower limit pressure switch indicates that the accumulator hydraulic pressure is From the time when a signal indicating that the pressure is equal to or higher than the lower limit pressure (ie, when the signal changes from a signal indicating that the accumulator hydraulic pressure is lower than the lower limit pressure to a signal indicating higher than the lower limit pressure) When the “normal pump operating time” has elapsed, the hydraulic pump is stopped, the initial control is terminated, and the normal control is started. It is preferably configured.

  According to this, when the accumulator hydraulic pressure is less than the lower limit pressure when the initial time has elapsed, the driving of the hydraulic pump is further continued as the initial control, and then the accumulator hydraulic pressure reaches the upper limit pressure. Thus, the hydraulic pump is stopped and the initial control is finished. Therefore, at the end of the initial control, the accumulator can be in the same state as when the hydraulic pump driven during the normal control is stopped, and a smooth transition from the initial control to the normal control is achieved. obtain.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a vehicle brake fluid pressure control device to which a hydraulic fluid storage device (control device) A according to an embodiment of the present invention is applied.

  The brake fluid pressure control device includes a hydraulic fluid storage device A that stores high-pressure brake fluid (hydraulic fluid), and a brake fluid pressure generator B that generates brake fluid pressure according to the operating force of the brake pedal BP. It consists of

  The hydraulic fluid storage device A includes an electric motor M, a hydraulic pump P that is driven by the electric motor M and sucks and discharges brake fluid (hydraulic fluid) in the reservoir R, and a discharge side of the hydraulic pump P Are connected via a check valve V and accumulate accumulator Acc discharged from the hydraulic pump P, a pressure switch PS (hydraulic pressure signal generating means, lower limit pressure switch), a relief valve RV, And an ECU (control device, control means) including a CPU.

  As will be described later, in principle, the electric motor M (and hence the hydraulic pump P) has a predetermined pressure in the hydraulic circuit to which the accumulator Acc is connected (hereinafter referred to as “accumulator pressure Pac”). The drive is controlled according to a drive signal from the CPU so that the pressure (high pressure) is between the lower limit pressure Pon and the predetermined upper limit pressure Poff.

  The pressure switch PS generates an ON signal (High signal) when the accumulator hydraulic pressure Pac is equal to or higher than the lower limit pressure Pon, and generates an OFF signal (Low signal) when the accumulator hydraulic pressure Pac is lower than the lower limit pressure Pon. It is like that. A signal generated by the pressure switch PS is supplied to the CPU.

  The relief valve RV is opened when the accumulator hydraulic pressure Pac reaches a predetermined abnormal pressure (relief pressure Prel) higher than the upper limit pressure Poff, and the hydraulic fluid in the hydraulic circuit to which the accumulator Acc is connected is opened. It opens to the reservoir R. Thereby, the hydraulic circuit to which the accumulator Acc is connected is protected.

  Further, the CPU is energized based on electric power from a battery (not shown) and executes various calculations, determinations, drive instructions for the hydraulic pump P, and the like only when the ignition switch IG of the vehicle is in the ON state. It is supposed to be. The configuration of the accumulator Acc will be described in detail later.

  The brake fluid pressure generator B is composed of a fluid pressure booster HB that responds when the brake pedal BP is operated, and a master cylinder MC that is connected to the fluid pressure booster HB.

  The hydraulic booster HB is connected to the hydraulic fluid storage device A (the hydraulic pressure circuit to which the accumulator Acc is connected), and uses the high pressure supplied from the hydraulic fluid storage device A to operate the brake pedal BP. Is assisted at a predetermined rate, and the assisted operating force is transmitted to the master cylinder MC.

  The master cylinder MC generates a master cylinder hydraulic pressure corresponding to the assisted operating force, and this master cylinder hydraulic pressure is supplied to the wheel cylinder WC. As a result, a braking force corresponding to the operating force of the brake pedal BP is applied to the wheels.

  Hereinafter, the configuration and operation of the accumulator Acc will be described with reference to FIGS. The accumulator Acc is a metal bellows type hydraulic accumulator and includes a shell 11 forming a pressure space Ro and a bellows-shaped bellows 12 disposed in the pressure space Ro as shown in FIGS. ing. The shell 11 is composed of two upper and lower members, and these members are joined and connected in a liquid-tight manner, and a plug member 13 for sealing the gas filling port 11a1 is hermetically attached to the upper end wall 11a. ing.

  The bellows 12 includes a cylindrical metal-made bellows-like portion 12a that can be expanded and contracted in the illustrated vertical direction, and a metal movable plate 12b that is airtight and liquid-tightly coupled to the upper end of the bellows-like portion 12a. The lower end of the bellows-like portion 12a is fixed to the lower end wall 11b of the shell 11 in an air-tight and liquid-tight manner. Accordingly, the bellows 12 communicates the pressure space Ro with the outer gas chamber R1 in which a predetermined gas (for example, nitrogen gas) is sealed, and the other end of the communication path S, one end of which communicates with the hydraulic circuit. It is divided into an inner working fluid chamber R2. A stay 14 and a cylindrical body 15 are disposed in the inner space of the bellows 12, that is, in the hydraulic fluid chamber R2.

  The stay 14 divides the hydraulic fluid chamber R2 in the bellows 12 into an outer hydraulic fluid chamber R2a and an inner hydraulic fluid chamber R2b, and restricts the contraction movement of the bellows 12. The lower end in the drawing is the lower end wall of the shell 11. It has a cylindrical wall portion 14a that is liquid-tightly fixed to 11b, and an upper bottom wall portion 14b that is integrally formed at the upper end of the cylindrical wall portion 14a. In addition, a communication hole 14b1 for communicating the outer working fluid chamber R2a and the inner working fluid chamber R2b is formed in the upper bottom wall portion 14b of the stay 14.

  The tubular body 15 is fixed in a liquid-tight manner to the lower end wall 11b of the shell 11 and the cylindrical wall portion 14a of the stay 14 by the annular flange portion 15a, and penetrates the lower end wall 11b of the shell 11 downward. The lower cylinder part 15b is extended. In addition, the communication path S described above is formed in the center of the cylindrical body 15.

  Further, an O-ring mounting groove 15c and a mounting male screw 15d are formed in the lower cylindrical portion 15b of the cylindrical body 15, and the mounting male screw 15d is mounted with the O-ring 17 mounted in the O-ring mounting groove 15c. The accumulator Acc is detachably attached to the support body 21 by screwing it into the female screw 21a of the support body 21.

  An annular seal member 12 c is provided on the lower surface of the movable plate 12 b in the bellows 12. The annular seal member 12c can be seated and separated with respect to the upper bottom wall portion 14b of the stay 14 in accordance with the movement of the movable plate 12b in the illustrated vertical direction. In other words, the communication hole 14b1 (that is, the inner working fluid chamber R2b) and the outer working fluid chamber R2a of the upper bottom wall portion 14b of the stay 14 are separated and communicated (communication) according to the vertical movement of the movable plate 12b in the figure.・ Can be blocked).

  A gas having a predetermined pressure (hereinafter referred to as “gas filling pressure Pg0”) is sealed in advance in the gas chamber R1 of the accumulator Acc. Therefore, when the pressure in the hydraulic fluid chamber R2 (that is, the accumulator hydraulic pressure Pac) exceeds the gas sealing pressure Pg0 and becomes the gas sealing pressure Pg0 or less, the annular seal member 12c is against the upper bottom wall portion 14b of the stay 14. Sit down.

  As a result, even if the accumulator hydraulic pressure Pac changes, the bellows 12 (movable plate 12b) is in the gas-filled position (the position shown in FIG. 2; the position where the volume of the hydraulic fluid chamber R2 is minimized. May be said to be maintained). In this state, the accumulator Acc cannot exhibit the function of accumulating hydraulic fluid. Hereinafter, this state is referred to as an “inactive state”.

  In this non-operating state, the outer hydraulic fluid chamber R2a is blocked from the inner hydraulic fluid chamber R2b. Therefore, even if the pressure in the inner working fluid chamber R2b (that is, the accumulator fluid pressure Pac) decreases from the gas filling pressure Pg0, the pressure in the outer working fluid chamber R2a can be maintained at the gas filling pressure Pg0 (see FIG. 2). ). Further, the pressure in the gas chamber R1 (gas pressure Pg) is maintained at the gas charging pressure Pg0.

  As a result, no pressure difference is generated between the radially inner side and the radially outer side of the bellows-like portion 12a of the bellows 12. Accordingly, the bellows-like portion 12a is prevented from contracting inward in the radial direction, so that the bellows-like portion 12a is protected in the non-operating state.

  On the other hand, once the accumulator Acc is deactivated, the pressure receiving area where the movable plate 12b of the bellows 12 receives the accumulator hydraulic pressure Pac from the lower side in the figure is the inner diameter d (see FIG. 2) of the annular seal member 12c. The area of the circle. Further, as described above, in the non-operating state, both the gas pressure Pg and the pressure in the outer working fluid chamber R2a are maintained at the gas filling pressure Pg0.

  Therefore, the pressure receiving area where the movable plate 12b substantially receives the gas sealing pressure Pg0 from above is the area of a circle whose diameter is the outer diameter D (see FIG. 2) of the annular seal member 12c. From the above, the accumulator hydraulic pressure Pac required for moving the annular seal member 12c from the original position (that is, the annular seal member 12c seated on the upper bottom wall portion 14b of the stay 14 is removed from the upper bottom wall portion 14b. The accumulator hydraulic pressure Pac necessary for separating the seat (hereinafter referred to as “valve opening pressure Pvo”) can be expressed by the following equation (1). In this example, the valve opening pressure Pvo is set to a pressure smaller than the lower limit pressure Pon.

Pvo = Pg0 ・ (D / d) ² ... (1)

  Therefore, when the accumulator hydraulic pressure Pac becomes larger than the valve opening pressure Pvo by the operation of the hydraulic pressure pump P when the accumulator Acc is in an inoperative state, the movable plate 12b is basically moved upward from the original position in the figure. Move to. Thereafter, the movable plate 12b freely moves in the vertical direction in the figure according to the change of the accumulator hydraulic pressure Pac so that the gas pressure Pg becomes equal to the accumulator hydraulic pressure Pac (see FIG. 3). ). In other words, the amount of hydraulic fluid in the hydraulic circuit to which the accumulator Acc is connected increases as the accumulator hydraulic pressure Pac increases.

  As a result, the accumulator Acc exhibits the function of accumulating hydraulic fluid. Hereinafter, this state is referred to as an “operating state”. Thus, the accumulator Acc in the non-operating state normally shifts to the operating state when the accumulator hydraulic pressure Pac rises to the valve opening pressure Pvo.

  By the way, for example, when the ignition switch IG of the vehicle is maintained in the OFF state for a long time (therefore, the hydraulic pump P is stopped for a long time) or the like, the hydraulic circuit (in particular, The state where the accumulator hydraulic pressure Pac is reduced to substantially atmospheric pressure due to leakage of hydraulic fluid at the seal portion of the check valve V and the seal portion of the hydraulic pressure booster HB can be continued for a long time. In this case, the accumulator Acc is maintained in a non-operating state for a long time.

  In such a case, the annular seal member 12c (the seal surface (lower surface)) is maintained in a state where it is pressed against the upper bottom wall portion 14b of the stay 14 with a strong force over a long period of time. As a result, the annular seal member 12c may stick to the upper bottom wall portion 14b of the stay 14 in some cases. When the annular seal member 12c is fixed, the accumulator Acc may be maintained in the non-operating state even when the accumulator hydraulic pressure Pac rises to the valve opening pressure Pvo.

  The hydraulic fluid storage device (control device thereof) (hereinafter referred to as “this device”) according to the present invention turns the ignition switch IG from the OFF state to the ON state even when the annular seal member 12c is stuck. Immediately after changing to the state, the accumulator Acc is reliably transferred from the non-operating state to the operating state.

(Outline of drive control of hydraulic pump P)
Hereinafter, drive control of the hydraulic pump P by the present apparatus (CPU shown in FIG. 1) will be described with reference to the time charts of FIGS. First, reference is made to the time chart of FIG. FIG. 4 shows that the ignition switch IG is maintained in the OFF state for a long time before the time t1, and as a result, the driver moves the vehicle at the time t1 while the accumulator hydraulic pressure Pac is maintained at the atmospheric pressure. Shows change of accumulator hydraulic pressure Pac, driving (ON) / stopped (OFF) state of hydraulic pump P, and change of signal of pressure switch PS when changing ignition switch IG from OFF to ON Yes.

  When the ignition switch IG is changed from the OFF state to the ON state and energization of the CPU is started, the apparatus first executes initial control. In principle, the initial control is control that continues to drive the electric motor M and therefore the hydraulic pump P only during the initial time Ts, regardless of the accumulator hydraulic pressure Pac.

  Here, the initial time Ts is set to a time required for the accumulator hydraulic pressure Pac to reach the relief pressure Pref from the upper limit pressure Poff by the operation of the hydraulic pump P when the accumulator Acc is in an operating state. This initial time Ts can be measured and acquired in advance through experiments or the like.

  Hereinafter, first, the case where the “adhesion of the annular seal member 12c” has not occurred at time t1 will be described. When the hydraulic pump P is started to be driven at time t1, the accumulator is maintained after time t1 until time t2 when the accumulator hydraulic pressure Pac reaches the valve opening pressure Pvo (time when a very short time has elapsed from time t1). The hydraulic pressure Pac rises rapidly. This is because the volume of the hydraulic fluid in the hydraulic circuit to which the accumulator Acc is connected cannot substantially expand since the accumulator Acc is maintained in the non-operating state at times t1 to t2. The bulk modulus of hydraulic fluid (brake fluid) is based on a considerably high value.

  In this case, at time t2, the annular seal member 12c immediately moves away from the upper bottom wall portion 14b of the stay 14, so that the accumulator Acc immediately shifts from the inoperative state to the activated state. As a result, from time t2 to time t3 when the initial time Ts elapses, the accumulator hydraulic pressure Pac is changed between the hydraulic fluid discharge amount per unit time by the hydraulic pump P and the gas state of the gas chamber R1. It rises relatively slowly according to the relationship determined accordingly (see solid line). Thereby, the working fluid is gradually accumulated in the working fluid chamber R2 of the accumulator Acc.

  On the other hand, when the above-mentioned “adhesion of the annular seal member 12c” occurs at time t1, the accumulator Acc is maintained in the inactive state even at time t2 when the accumulator hydraulic pressure Pac reaches the valve opening pressure Pvo. . As a result, the accumulator hydraulic pressure Pac continues to increase further after time t2, and is a pressure at which the “adhesion of the annular seal member 12c” is eliminated immediately after time t2 (in this example, the relief pressure is larger than the upper limit pressure Poff). (Pressure less than Pref) is reached (see dashed line).

  As a result, the “adhesion of the annular seal member 12c” is eliminated, and the accumulator Acc shifts to the operating state. Thereafter, as the movable plate 12b of the bellows 12 suddenly moves upward from the original position in FIG. 2, the volume of the hydraulic fluid in the hydraulic circuit increases rapidly. As a result, the accumulator hydraulic pressure Pac suddenly decreases toward the accumulator hydraulic pressure Pac between times t2 and t3 when the above “adhesion of the annular seal member 12c” has not occurred (see the broken line).

  As described above, even when the above-mentioned “adhesion of the annular seal member 12c” occurs at the time t1, the “adhesion of the annular seal member 12c” can be surely eliminated by executing this initial control. At time t3 when the initial time Ts elapses, the accumulator hydraulic pressure Pac becomes the value P1 regardless of the presence or absence of the “adhesion of the annular seal member 12c”.

  In this example, the value P1 is smaller than the lower limit pressure Pon. That is, at time t3, the pressure switch PS generates an OFF signal. As described above, when the pressure switch PS generates an OFF signal when the initial time Ts has elapsed, the present apparatus does not end the initial control, and until the accumulator hydraulic pressure Pac reaches the upper limit pressure Poff. Meanwhile, the driving of the hydraulic pump P is further continued as the initial control. As a result, the accumulator hydraulic pressure Pac rises relatively slowly after time t3 according to the relationship determined according to the discharge amount of hydraulic fluid per unit time by the hydraulic pump P and the gas state of the gas chamber R1. Keep doing.

  More specifically, after the time t3, the apparatus recognizes whether or not the signal generated by the pressure switch PS has become an ON signal in order to recognize when the accumulator hydraulic pressure Pac has reached the lower limit pressure Pon. Monitor. When the signal generated by the pressure switch PS becomes the ON signal at time t4, the apparatus continues to drive the hydraulic pump P until the normal pump operation time Ta elapses from time t4. At time t5 when the normal pump operating time Ta elapses, the apparatus stops the hydraulic pump P and ends the initial control.

  Here, the normal pump operating time Ta is set to a time required for the accumulator hydraulic pressure Pac to reach the upper limit pressure Poff from the lower limit pressure Pon by the operation of the hydraulic pump P when the accumulator Acc is in the operating state. Yes. The normal pump operating time Ta can also be measured and acquired in advance by experiments or the like, similar to the initial time Ts. Thereby, the time t5 coincides with the time when the accumulator hydraulic pressure Pac reaches the upper limit pressure Poff.

  When the initial control is finished, the apparatus immediately executes normal control. The normal control is a control that drives the hydraulic pump P when the accumulator hydraulic pressure Pac becomes less than the lower limit pressure Pon and stops the hydraulic pump P when the accumulator hydraulic pressure Pac exceeds the upper limit pressure Poff. is there.

  More specifically, the accumulator hydraulic pressure Pac boosted to the upper limit pressure Poff at time t5 is a hydraulic pressure circuit to which hydraulic fluid is supplied to the hydraulic booster HB and the accumulator Acc is connected after time t5. It decreases due to leakage of hydraulic fluid. At this time, this apparatus first monitors whether or not the signal generated by the pressure switch PS is an OFF signal in order to recognize the time point when the accumulator hydraulic pressure Pac has decreased to the lower limit pressure Pon (less than).

  When the signal generated by the pressure switch PS becomes an OFF signal at time t6, the apparatus continues to drive the hydraulic pump P from time t6 to time t7 when the normal pump operating time Ta elapses. At time t7, the present apparatus stops the hydraulic pump P. Thereby, the time t7 coincides with the time when the accumulator hydraulic pressure Pac reaches the upper limit pressure Poff.

  Even after time t7, until the ignition switch IG is turned off, the apparatus continues normal control by repeatedly executing the operation from time t5 to t7 described above. The case where the accumulator hydraulic pressure Pac (= P1) at the time when the initial time Ts has elapsed (time t3 in FIG. 4) is less than the lower limit pressure Pon has been described with reference to FIG.

  Next, referring to the time charts of FIGS. 5 and 6, the accumulator hydraulic pressure Pac (= P1) at the time when the initial time Ts has elapsed (time t13 in FIG. 5, time t23 in FIG. 6) is the lower limit pressure. The case where it becomes Pon or more will be described. First, reference is made to the time chart of FIG. Times t11, t13, t16, and t17 in FIG. 5 correspond to times t1, t3, t6, and t7 in FIG. 4, respectively.

  FIG. 5 shows that the ignition switch IG is changed from the ON state to the OFF state at a relatively short time before the time t11, the normal control is terminated, and the accumulator hydraulic pressure Pac that gradually decreases after the simultaneous point is Accumulator hydraulic pressure when the driver changes the ignition switch IG of the vehicle from the OFF state to the ON state at time t11 in a state where the valve opening pressure Pvo and the lower limit pressure Pon are at t11. A change in Pac, a drive (ON) / stop (OFF) state of the hydraulic pump P, and a change in the signal of the pressure switch PS are shown.

  In this case, the accumulator Acc is still maintained in the operating state at time t11. Accordingly, during the initial time Ts (time t11 to t13) when the hydraulic pump P is driven by the initial control, the accumulator hydraulic pressure Pac is determined by the amount of hydraulic fluid discharged by the hydraulic pump P per unit time and the gas chamber R1. It rises relatively slowly according to the relationship determined according to the gas state. Thereby, the working fluid is gradually accumulated in the working fluid chamber R2 of the accumulator Acc.

  In this example, the accumulator hydraulic pressure Pac reaches the lower limit pressure Pon at time t12 before time t13 when the initial time Ts elapses, and is equal to or higher than the lower limit pressure Pon at time t13 (P1> Pon). That is, at time t13, the pressure switch PS generates an ON signal. As described above, when the pressure switch PS generates the ON signal when the initial time Ts has elapsed, the present apparatus immediately stops the hydraulic pump P and immediately ends the initial control as a rule. Thereby, the accumulator hydraulic pressure Pac equal to or higher than the lower limit pressure Pon can be secured without unnecessarily continuing the driving of the hydraulic pump P.

  The apparatus immediately starts normal control at time t13 and continues this normal control until the ignition switch IG is turned off, as in the case shown in FIG.

  FIG. 6 shows a state in which the ignition switch IG is changed from the ON state to the OFF state just before time t21, the normal control is finished, and the accumulator hydraulic pressure Pac is slightly lower than the upper limit pressure Poff at time t21. At time t21, when the driver changes the ignition switch IG of the vehicle from the OFF state to the ON state, the change in the accumulator hydraulic pressure Pac, the driving (ON) / stopping (OFF) state of the hydraulic pump P, And the change of the signal of pressure switch PS is shown. Times t21, t23, t26, and t27 in FIG. 6 correspond to times t11, t13, t16, and t17 in FIG. 5, respectively.

  Also in this case, as in the case shown in FIG. 5 described above, the accumulator hydraulic pressure Pac becomes equal to or higher than the lower limit pressure Pon at time t23 when the initial time Ts elapses (P1> Pon). Accordingly, the present apparatus immediately stops the hydraulic pump P at time t23, immediately ends the initial control as a rule, and immediately starts the normal control described above.

  Here, the accumulator hydraulic pressure Pac (= P1) at time t23 does not exceed the relief pressure Prel. As described above, the initial time Ts is set to the time required for the accumulator hydraulic pressure Pac to reach the relief pressure Pref from the upper limit pressure Poff by the operation of the hydraulic pump P when the accumulator Acc is in the operating state. And the accumulator hydraulic pressure Pac at the time when the ignition switch is changed from the OFF state to the ON state (time t21 in FIG. 6) is at least lower than the upper limit pressure Poff by the normal control executed before that. Is based on. Thereby, generation | occurrence | production of the noise by valve opening of the relief valve RV, and useless consumption of the energy which a high pressure hydraulic fluid has can be prevented.

  The case where the accumulator hydraulic pressure Pac (= P1) at the time when the initial time Ts has elapsed (time t13 in FIG. 5 and time t23 in FIG. 6) is equal to or higher than the lower limit pressure Pon is described with reference to FIGS. Explained.

(Actual operation)
Next, the actual operation of the control device (CPU) of the hydraulic fluid storage device A configured as described above according to the present invention will be described with reference to FIGS. explain. The CPU executes the routines shown in FIGS. 7 and 8 only when the ignition switch IG is in the ON state.

  The CPU repeatedly executes a routine for executing the initial control shown in FIG. 7 every elapse of a predetermined time (for example, 6 msec). Therefore, when the predetermined timing comes, the CPU starts the process from step 700 and proceeds to step 705 to determine whether or not the ignition switch IG has been changed from the OFF state to the ON state.

  Assuming that the driver has just changed the ignition switch IG from the OFF state to the ON state, the CPU makes a “Yes” determination at step 705 to proceed to step 710 to set the value of the initial control execution flag INI. The value of the variable Mode is set to “1”, the value of the counter N is set to “0”, “1”.

  Here, the initial control execution flag INI indicates that the initial control is being executed when the value is “1”, and the normal control is being executed when the value is “0”. The variable Mode is “1” until the initial time Ts elapses during execution of the initial control (for example, time t1 to t3 in FIG. 4, time t11 to t13 in FIG. 5, time t21 to t23 in FIG. 6), The period corresponding to times t3 to t4 in FIG. 4 is set to “2”, and the period corresponding to times t4 to t5 in FIG. 4 is set to “3”. The value of the counter N represents the elapsed time from the time when the ignition switch IG is changed from the OFF state to the ON state.

  Next, the CPU proceeds to step 715 to instruct the motor M to drive the hydraulic pump P. Thereby, the driving of the hydraulic pump P is started and the initial control is started (see time t1 in FIG. 4, time t11 in FIG. 5, and time t21 in FIG. 6). Next, the CPU proceeds to step 720 to determine whether or not the value of the initial control execution flag INI is “1”. If the determination is “No”, the CPU immediately proceeds to step 799 and temporarily ends this routine.

  At present, the value of the initial control execution flag INI is “1”. Therefore, the CPU makes a “Yes” determination at step 720 to proceed to step 725 to determine whether or not the value of the variable Mode is “1”, and again determines “Yes” to proceed to step 730. move on.

  In step 730, the CPU determines whether the value of the counter N is equal to the initial time corresponding value Ns corresponding to the initial time Ts. Since the value of the counter N is currently “0”, the CPU 61 determines “No” in step 730 and proceeds to step 735, increments the value of the counter N by “1”, and then proceeds to step 799. This routine is temporarily terminated.

  Thereafter, the CPU repeatedly executes the processing of steps 705 and 720 to 735 until the value of the counter N becomes equal to the initial time corresponding value Ns. During this time, the drive of the hydraulic pump P is continued. As a result, by repeating the processing of step 735, when the value of the counter N becomes equal to the initial time corresponding value Ns (thus, when the initial time Ts elapses) (time t3 in FIG. 4, time t13 in FIG. 5, FIG. 6), the CPU determines “Yes” when it proceeds to step 730, and proceeds to step 740.

  In step 740, the CPU determines whether or not the pressure switch PS is generating an ON signal. Now, as shown at time t3 in FIG. 4, the description will be continued assuming that the current accumulator hydraulic pressure Pac is lower than the lower limit pressure Pon.

  In this case, the current pressure switch PS generates an OFF signal. Accordingly, the CPU makes a “No” determination at step 740 to proceed to step 745, and after changing the value of the variable Mode from “1” to “2”, proceeds to step 799 to end the present routine tentatively. As a result, the driving of the hydraulic pump P is further continued.

  Thereafter, when the CPU proceeds to step 725, the CPU makes a “No” determination to proceed to step 750. In step 750, the CPU determines whether or not the value of the variable Mode is “2”, and here “Yes”. And the process proceeds to step 755.

  In step 755, the CPU determines whether or not the pressure switch PS is generating an ON signal. Since the present time is immediately after the initial time Ts has elapsed (immediately after time t3 in FIG. 4), the accumulator hydraulic pressure Pac is still less than the lower limit pressure Pon. Accordingly, the CPU makes a “No” determination at step 755 to immediately proceed to step 799 to end the present routine tentatively.

  Thereafter, the CPU repeatedly executes the processes of steps 705, 720, 725, 750, and 755 until the pressure switch PS generates an ON signal. During this time, the drive of the hydraulic pump P is continued. Accordingly, when the accumulator hydraulic pressure Pac becomes equal to or higher than the lower limit pressure Pon (see time t4 in FIG. 4), the CPU determines “Yes” when the process proceeds to step 755, and proceeds to step 760.

  In step 760, the CPU changes the value of the variable Mode from “2” to “3”, sets the value of the counter M to “0” in the subsequent step 765, and then proceeds to step 799 to execute this routine. Exit once. Here, the value of the counter M represents an elapsed time from when the accumulator hydraulic pressure Pac becomes the lower limit pressure Pon.

  As a result, after that, when the CPU proceeds to step 750, the CPU makes a “No” determination to proceed to step 770, where the value of the counter M corresponds to the normal pump operation time Ta in step 770. It is determined whether or not it is equal to the time correspondence value Ma. Since the value of the counter M is “0” at this time, the CPU makes a “No” determination at step 770 to proceed to step 775 to increment the value of the counter M by “1”.

  Thereafter, the CPU repeatedly executes the processing of steps 705, 720, 725, 750, 770, and 775 until the value of the counter M becomes equal to the normal pump operation time corresponding value Ma. During this time, the driving of the hydraulic pump P is continued. As a result, by repeating the processing of step 775, when the value of the counter M becomes equal to the normal pump operation time corresponding value Ma (thus, when the normal pump operation time Ta elapses) (see time t5 in FIG. 4), When the CPU proceeds to step 770, the CPU determines “Yes”, and proceeds to step 780.

  In step 780, the CPU instructs the motor M to stop the hydraulic pump P, and in step 785, the value of the initial control execution flag INI is changed from “1” to “0”. Thereby, the hydraulic pump P is stopped and the initial control is ended (see time t5 in FIG. 4). Thereafter (that is, during execution of normal control), the CPU makes a “No” determination when it proceeds from step 705 to step 720, and immediately proceeds to step 799 to end this routine once.

  Next, as shown at time t13 in FIG. 5 and time t23 in FIG. 6, the case where the accumulator hydraulic pressure Pac is equal to or higher than the lower limit pressure Pon when the initial time Ts has elapsed will be described. In this case, the CPU that has determined “Yes” in step 730 after the elapse of the initial time Ts proceeds to step 740, determines “Yes” in step 740, and then proceeds to step 790.

  In step 790, the CPU immediately instructs the motor M to stop the hydraulic pump P. In the next step 795, the CPU immediately changes the value of the initial control execution flag INI from “1” to “0”. Thereby, the hydraulic pump P is stopped and the initial control is ended (see time t13 in FIG. 5 and time t23 in FIG. 6). Thereafter (that is, during execution of normal control), the CPU makes a “No” determination when it proceeds from step 705 to step 720, and immediately proceeds to step 799 to end this routine once. The operation in the initial control has been described above.

  Next, the operation in normal control will be described. The CPU repeatedly executes the routine for executing the normal control shown in FIG. 8 every elapse of a predetermined time (for example, 6 msec). Therefore, when the predetermined timing comes, the CPU starts the process from step 800, proceeds to step 805, determines whether or not the value of the initial control execution flag INI is “0”, and determines “No”. (When INI = 1, that is, when initial control is being executed), the routine immediately proceeds to step 895, and this routine is once terminated.

  Now, immediately after the end of the initial control (that is, immediately after step 785 or 795 in FIG. 7 is executed. For example, see time t5 in FIG. 4, time t13 in FIG. 5, and time t23 in FIG. 6). Then, the CPU makes a “Yes” determination at step 805 to proceed to step 810 to determine whether or not the hydraulic pump P is stopped.

  At the present time, since the hydraulic pump P is stopped by the execution of the previous step 780 or step 790, the CPU makes a “Yes” determination at step 810 to proceed to step 815, and the pressure switch PS outputs an OFF signal. Determine whether it has occurred.

  Since the present time is immediately after the end of the initial control, the accumulator hydraulic pressure Pac is equal to or higher than the lower limit pressure Pon. Therefore, the CPU makes a “No” determination at step 815 to immediately proceed to step 895 to end the present routine tentatively.

  Thereafter, the CPU steps until the accumulator hydraulic pressure Pac, which decreases due to leakage of hydraulic fluid in the hydraulic circuit to which the accumulator Acc is connected, and the supply of hydraulic fluid to the hydraulic booster HB becomes less than the lower limit pressure Pon. The processes of 805 to 815 are repeatedly executed.

  When the accumulator hydraulic pressure Pac becomes lower than the lower limit pressure Pon (see, for example, time t6 in FIG. 4, time t16 in FIG. 5, time t26 in FIG. 6), the CPU determines “Yes” when the process proceeds to step 815. In step 820, the drive instruction of the hydraulic pump P is given to the motor M, and in step 825, the value of the counter M is initialized to “0”. Thereby, the driving of the hydraulic pump P is started. Note that the value of the counter M represents the elapsed time from when the accumulator hydraulic pressure Pac becomes the lower limit pressure Pon, as in the routine of FIG.

  As a result, after that, when the CPU proceeds to step 810, the CPU makes a “No” determination to proceed to step 830, where the value of the counter M corresponds to the normal pump operating time Ta in step 830. It is determined whether or not the operation time corresponding value Ma is equal. Since the value of the counter M is “0” at this time, the CPU makes a “No” determination at step 830 to proceed to step 835 to increment the value of the counter M by “1”.

  Thereafter, the CPU repeatedly executes the processing of steps 805, 810, 830, and 835 until the value of the counter M becomes equal to the normal pump operation time corresponding value Ma. During this time, the driving of the hydraulic pump P is continued. As a result, when the process of step 835 is repeated, the value of the counter M becomes equal to the normal pump operation time corresponding value Ma (thus, when the normal pump operation time Ta elapses) (time t7 in FIG. 4 and FIG. 5). At time t17, see time t27 in FIG. 6), the CPU determines “Yes” when it proceeds to step 830, and proceeds to step 840.

  In step 840, the CPU instructs the motor M to stop the hydraulic pump P. Thereby, the hydraulic pump P is stopped. Thereafter, when the CPU proceeds to step 810, the CPU again determines “Yes”, and starts again monitoring whether the pressure switch PS generates an OFF signal. As described above, the CPU repeatedly executes such processing until the ignition switch IG is turned off. Thereby, normal control is achieved.

  As described above, according to the control device for a hydraulic fluid storage device for a vehicle according to the invention, the accumulator hydraulic pressure is maintained for at least a predetermined initial time Ts after the ignition switch IG is changed from the OFF state to the ON state. Regardless of the Pac, the hydraulic pump P is always driven as the initial control. Therefore, when the partition member of the accumulator Acc is fixed at the original position (position corresponding to the non-actuated state) (specifically, the annular seal member 12c provided on the lower surface of the possible plate 12b of the bellows 12). Even when the sealing surface is fixed to the upper bottom wall portion 14b of the stay 14, the fixing of the partition member can be surely eliminated before the initial time Ts elapses. As a result, the accumulator Acc Can be reliably shifted from the non-operating state to the operating state.

  Further, after the end of the initial control, normal control for maintaining the accumulator hydraulic pressure Pac at a pressure between the lower limit pressure Pon and the upper limit pressure Poff is executed. In this normal control, the accumulator hydraulic pressure Pac is set to the lower limit pressure Pon based only on the signal of the inexpensive pressure switch PS that selectively generates a signal corresponding to whether or not the accumulator hydraulic pressure Pac is equal to or higher than the lower limit pressure Pon. The hydraulic pump P is driven when a signal indicating that it is less than (OFF signal) is generated, and the accumulator hydraulic pressure Pac is increased from the lower limit pressure Pon by the operation of the hydraulic pump P from the time when the OFF signal is generated. The hydraulic pump P is stopped when a preset normal pump operating time Ta corresponding to the time required to reach the pressure Poff has elapsed. Therefore, it is possible to provide an inexpensive hydraulic fluid storage device that does not require an expensive pressure sensor in normal control.

Further, the partition member of the accumulator Acc is fixed, that is, the annular seal member 12c is fixed, as the seal area Z of the annular seal member 12c is increased (that is, Z = π / 4 · (D ² -d ² )). It tends to be difficult to occur. This is based on the fact that the larger the seal area Z, the smaller the surface pressure when the seal surface is pressed against the upper bottom wall portion 14b of the stay 14. Therefore, in order to suppress the occurrence of the sticking of the annular seal member 12c, it is preferable to increase the seal area Z.

  On the other hand, as can be understood from the above equation (1), generally increasing the seal area Z leads to increasing the valve opening pressure Pvo. Increasing the valve opening pressure Pvo means that it becomes difficult for the accumulator Acc to shift from the non-operating state to the operating state. However, according to the control device for a hydraulic fluid storage device for a vehicle according to the present invention, even when the valve opening pressure Pvo increases (for example, even when the valve opening pressure Pvo exceeds the upper limit pressure Poff), The accumulator Acc can be reliably shifted from the non-operating state to the operating state before the initial time Ts elapses. Therefore, the seal area Z can be set larger, and as a result, the occurrence of the sticking of the annular seal member 12c can be suppressed.

  The present invention is not limited to the above embodiment, and various modifications can be employed within the scope of the present invention. For example, in the above embodiment, a metal bellows type accumulator is used as the accumulator Acc, but a bladder type accumulator, a piston type accumulator, or the like may be used.

  In the above embodiment, the accumulator hydraulic pressure Pac (= P1) at the time when the initial time Ts has elapsed is equal to or higher than the lower limit pressure Pon (see time t13 in FIG. 5 and time t23 in FIG. 6). The hydraulic pump P is immediately stopped and the initial control is immediately terminated, but the driving of the hydraulic pump P is continued as the initial control until the accumulator hydraulic pressure Pac becomes equal to or higher than the upper limit pressure Poff. May be.

  In the above embodiment, when the accumulator hydraulic pressure Pac (= P1) at the time when the initial time Ts has elapsed is less than the lower limit pressure Pon (see time t3 in FIG. 4), the accumulator hydraulic pressure Pac is Until the upper limit pressure Poff is reached, the driving of the hydraulic pump P is further continued as the initial control. However, the accumulator hydraulic pressure Pac is a predetermined value between the lower limit pressure Poff and the upper limit pressure Pon. Until the pressure is reached, the driving of the hydraulic pump P may be further continued as the initial control.

  In the above-described embodiment, the initial time Ts and the normal pump operation time Ta are set to constant times, respectively, but the initial time Ts and / or the normal pump operation time Ta are set to the vehicle state (for example, The battery voltage, the temperature of the hydraulic fluid, etc.) may be changed.

  In the above embodiment, in normal control, the accumulator hydraulic pressure Pac is equal to or higher than the upper limit pressure Poff. When the signal of the lower limit pressure switch (pressure switch PS) changes (the accumulator hydraulic pressure Pac is lower limit pressure). A signal corresponding to whether or not the accumulator hydraulic pressure Pac is equal to or higher than the upper limit pressure Poff is determined using the fact that a predetermined time (normal pump operating time Ta) has elapsed since the time when the pressure became less than Pon. May be configured to determine that the accumulator hydraulic pressure Pac is equal to or higher than the upper limit pressure Poff based on a signal from the upper limit pressure switch.

1 is a schematic configuration diagram of a vehicle brake fluid pressure control device to which a hydraulic fluid storage device according to an embodiment of the present invention is applied. FIG. 2 is an enlarged cross-sectional view of the accumulator shown in FIG. 1 in a state where hydraulic fluid is not accumulated in the hydraulic fluid chamber (non-actuated state). It is an expanded sectional view of the accumulator shown in Drawing 1 in the state (operating state) where hydraulic fluid is accumulated in the hydraulic fluid chamber. The change in accumulator hydraulic pressure, hydraulic pump when the hydraulic pump is controlled by the hydraulic fluid storage device shown in FIG. 1 and the accumulator hydraulic pressure is less than the lower limit pressure when the initial time has elapsed. It is the time chart which showed the change of the drive / stop state of this, and the signal of a pressure switch. The change in accumulator hydraulic pressure when the hydraulic pump is controlled by the hydraulic fluid storage device shown in FIG. 1 and the accumulator hydraulic pressure exceeds the lower limit when the initial time has elapsed, the hydraulic pump It is the time chart which showed the change of the drive / stop state of this, and the signal of a pressure switch. The change in accumulator hydraulic pressure when the hydraulic pump is controlled by the hydraulic fluid storage device shown in FIG. 1 and the accumulator hydraulic pressure exceeds the lower limit when the initial time has elapsed, the hydraulic pump It is the time chart which showed the change of the drive / stop state of this, and the signal of a pressure switch. 2 is a flowchart showing a routine for performing initial control executed by a CPU shown in FIG. 1. 2 is a flowchart showing a routine for performing normal control executed by a CPU shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Shell, 12 ... Bellows, 12a ... Bellows-shaped part, 12b ... Movable plate, 12c ... Annular seal member, 14 ... Stay, 14b ... Upper bottom wall part, Ro ... Pressure space, R1 ... Gas chamber, R2 ... Hydraulic fluid Chamber, R2a ... internal hydraulic fluid chamber, R2b ... external hydraulic fluid chamber, Acc ... accumulator, P ... hydraulic pump, M ... electric motor, V ... check valve, PS ... pressure sensor, ECU ... electric control device (CPU), R ... reservoir, BP ... brake pedal, HB ... hydraulic booster (hydraulic actuator), MC ... master cylinder, WC ... wheel cylinder

Claims (7)

A hydraulic pump that discharges the hydraulic fluid to the hydraulic circuit, an accumulator that accumulates the hydraulic fluid discharged to the hydraulic circuit by the operation of the hydraulic pump, and a pressure of the hydraulic fluid that is accumulated in the accumulator Applied to a vehicle hydraulic fluid storage device having a hydraulic pressure signal generating means for generating a signal related to a certain accumulator hydraulic pressure,
When it is determined that the accumulator hydraulic pressure is less than a predetermined lower limit pressure based on the signal related to the accumulator hydraulic pressure in the energized state, the hydraulic pump is driven and the signal related to the accumulator hydraulic pressure is The control device for the hydraulic fluid storage device of the vehicle provided with control means for executing the normal control for stopping the hydraulic pressure pump when it is determined that the accumulator hydraulic pressure is equal to or higher than a predetermined upper limit pressure greater than the lower limit pressure In
The control means includes
Initial control is performed to drive the hydraulic pump for a predetermined initial time regardless of the accumulator hydraulic pressure for a predetermined initial time after the control means changes from the non-energized state to the energized state. A control device for a hydraulic fluid storage device for a vehicle configured to execute instead of the normal control. The control device for a hydraulic fluid storage device for a vehicle according to claim 1,
The hydraulic fluid storage device of the vehicle further includes a relief valve that opens when the accumulator hydraulic pressure exceeds a predetermined relief pressure greater than the upper limit pressure to release the hydraulic fluid in the hydraulic circuit. ,
The control means includes
As the initial time, the hydraulic fluid of the vehicle configured to use a preset time not exceeding the time required for the accumulator hydraulic pressure to reach the relief pressure from the upper limit pressure by the operation of the hydraulic pump. Storage device control device. In the control device for the hydraulic fluid storage device for a vehicle according to claim 1 or 2,
The control means includes
When it is determined that the accumulator hydraulic pressure is equal to or higher than the lower limit pressure based on a signal related to the accumulator hydraulic pressure when the initial time has elapsed, the hydraulic pump is stopped at the same point. The control apparatus of the hydraulic fluid storage device of the comprised vehicle. In the control device for the hydraulic fluid storage device for a vehicle according to claim 1 or 2,
The hydraulic pressure signal generating means includes a lower limit pressure switch that selectively generates a signal corresponding to whether or not the accumulator hydraulic pressure is equal to or higher than the lower limit pressure,
The control means includes
A storage means for preliminarily storing, as a normal pump operating time, a time required for the accumulator hydraulic pressure to reach the upper limit pressure from the lower limit pressure by the operation of the hydraulic pump;
When executing the normal control,
When the signal generated by the lower limit side pressure switch is a signal indicating that the accumulator hydraulic pressure is less than the lower limit pressure, it is determined that the accumulator hydraulic pressure is less than the lower limit pressure, and the accumulator hydraulic pressure From the time when it is determined that the pressure is less than the lower limit pressure, the accumulator fluid pressure is determined to be equal to or higher than the upper limit pressure when the stored normal pump operating time has elapsed. Control device for the device. The control device for a hydraulic fluid storage device for a vehicle according to claim 4,
The control means includes
When the signal generated by the lower limit pressure switch when the initial time has elapsed is a signal indicating that the accumulator hydraulic pressure is equal to or higher than the lower limit pressure, the hydraulic pump is stopped at the same point. The control apparatus of the hydraulic fluid storage apparatus of the vehicle comprised as follows. In the control device for the hydraulic fluid storage device for a vehicle according to claim 4 or 5,
The control means includes
When the signal generated by the lower limit side pressure switch when the initial time has elapsed is a signal indicating that the accumulator hydraulic pressure is less than the lower limit pressure, the hydraulic pressure is also used as the initial control after the same point. The pump is driven further continuously, and the stored normal pump operating time has elapsed since the signal generated by the lower limit pressure switch becomes a signal indicating that the accumulator hydraulic pressure is equal to or higher than the lower limit pressure. And a control device for the hydraulic fluid storage device of the vehicle configured to stop the fluid pressure pump and terminate the initial control and start execution of the normal control. A vehicle hydraulic fluid storage device to which the vehicle hydraulic fluid storage device control device according to any one of claims 1 to 6 is applied, wherein the vehicle operation includes the control means of the control device. Liquid storage device.

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