JP5440403B2 - Braking device for vehicle - Google Patents

Description

  The present invention relates to a braking device for a vehicle such as an automobile, and more particularly to a braking device for a vehicle that increases or decreases the pressure in a wheel cylinder.

  As one of the braking devices for vehicles such as automobiles, a shut-off valve that shuts off the flow of oil as a working fluid from the wheel cylinder to the master cylinder as necessary, and an increase / decrease control valve that increases or decreases the pressure in the wheel cylinder A reservoir that receives and stores oil from the wheel cylinder in the reservoir chamber when the pressure increasing / decreasing control valve is in the pressure reducing position, and a pressure that is sucked and pressurized from the reservoir chamber and the pressure increasing / decreasing control valve is in the pressure increasing position. A vehicle braking device having a pump as a pressure supply means for supplying oil to a wheel cylinder through an increase / decrease control valve and a communication control valve for controlling communication between the master cylinder and the reservoir chamber is already known, For example, it is described in Patent Document 1 and Patent Document 2 below.

  In this type of braking device, in the normal braking mode, the pressure in the master cylinder is introduced into the wheel cylinder through the shut-off valve, so that the pressure in the wheel cylinder is increased or decreased by the pressure in the master cylinder. In the braking mode in which the pressure in the master cylinder must be higher than the pressure in the master cylinder, the shutoff valve shuts off the oil flow from the wheel cylinder to the master cylinder, and the pump is driven. Is supplied to and discharged from the wheel cylinder by the pressure increasing / decreasing control valve, and thereby the pressure in the wheel cylinder is controlled to a desired pressure.

  Further, according to this type of braking device, the communication control valve automatically opens and closes in accordance with the pressure in the master cylinder and the suction pressure of the pump, whereby the reservoir control valve in accordance with the pressure in the master cylinder and the suction pressure of the pump. Compared to the configuration in which the communication control valve is an electromagnetic valve and the electromagnetic valve is controlled based on the detection results of various sensors in order to function as a pressure adjusting valve that automatically adjusts the indoor pressure. Cost can be reduced, and control of the braking device can be simplified by reducing the control target of the braking device.

  By the way, in these conventional braking devices, the communication control valve is a normally open check valve in which the valve element is separated from the valve seat during non-braking when the driver does not perform braking operation. The master cylinder and the reservoir chamber are in communication with each other. When the brake operation is started by the driver and the pressure in the master cylinder is increased, the valve element of the check valve is caused to flow by the oil flow due to the differential pressure between the pressure in the master cylinder and the pressure in the reservoir chamber. The check valve is closed by sitting on the seat, and the communication between the master cylinder and the reservoir chamber is blocked.

  However, in the above-described conventional braking device, the check valve as the communication control valve is a normally-open check valve. Therefore, even if the braking operation is started by the driver, the amount of oil in the reservoir chamber increases and the reservoir valve increases. The check valve does not close until the piston moves to a position allowing the check valve to close and the differential pressure between the pressure in the master cylinder and the pressure in the reservoir chamber reaches a predetermined value. For this reason, the oil may flow from the master cylinder toward the reservoir chamber. As a result, the feeling is deteriorated due to a delay in the pressure increase in the wheel cylinder with respect to the driver's braking operation or a delay in the actual braking action. Therefore, it is necessary to improve the braking response when the driver starts the braking operation.

  In this regard, the applicant of the present application uses a communication control valve that controls communication between the master cylinder and the reservoir chamber as a normally closed valve as shown in Patent Document 3 below, and accompanies that the pump sucks oil from the reservoir chamber. Has proposed a vehicular braking device that opens the communication control valve by the suction pressure of the generated pump.

Japanese Patent Laid-Open No. 5-116607 JP-A-10-264801 JP 2008-7080 A

  By the way, in the conventional vehicle braking device, the pump sucks oil from the reservoir chamber, and the communication control valve controls the communication between the master cylinder and the reservoir chamber by the suction pressure accompanying the suction. When the communication control valve is in the open state, oil flows from the master cylinder (upstream side) to the reservoir chamber (downstream side) via the communication control valve, and the pump sucks the oil that has flowed into the reservoir chamber. In this case, the flow direction of oil from the master cylinder to the reservoir chamber is different from the opening direction of the communication control valve, and the pressure accompanying the flow of oil may act to close the communication control valve. Thus, when the pressure accompanying the flow of oil acts to close the communication control valve, the communication control valve repeatedly closes and opens in small increments according to the pressure change in the reservoir chamber. There is a possibility that so-called hunting is likely to occur, and there is a concern that the pump may affect the stable supply of oil under pressure.

  The present invention has been made to address the above-described problems, and an object of the present invention is to provide a vehicle braking device that stabilizes the operation of a communication control valve and stabilizes braking control.

  In order to achieve the above object, a shutoff valve that shuts off the flow of the working liquid from the wheel cylinder to the master cylinder as necessary, a pressure increase / decrease control valve that increases or decreases the pressure in the wheel cylinder, and the pressure increase / decrease control valve A reservoir that receives and stores the working fluid from the wheel cylinder in the reservoir chamber when the is in the decompression position, and at least the suction fluid is sucked and pressurized from the reservoir chamber and the pressure increase / decrease control valve is in the pressure increase position And a pressure supply means for supplying the working liquid to the wheel cylinder via the pressure increase / decrease control valve, and a communication control valve for controlling communication between the master cylinder and the pressure supply means. The communication control valve has a normally closed on-off valve and a valve-opening means that is driven by the suction pressure of the pressurizing supply means to open the on-off valve, The on-off valve is opened by the valve means the pressure of the working fluid flowing toward the pressurizing supply means from the master cylinder is in the act in a direction to open the on-off valve.

  In this case, the on-off valve has a valve element and valve element urging means for urging the valve element against the valve seat, and the valve element is applied to the valve seat by urging by the valve element urging means. The valve element may be a check valve that contacts and closes, and the valve element opens away from the valve seat by driving the valve opening means. In this case, the valve element has, for example, a poppet shape having a head portion and a spool portion having a smaller diameter than the head portion, and is supported by the valve housing so as to be able to reciprocate by the spool portion. Preferably, the valve element abuts against the valve seat by urging by the valve element urging means, and the head portion is opened away from the valve seat by pressing of the spool portion by driving of the valve opening means. In this case, an annular passage communicating with the master cylinder is formed in the spool portion, and when the head portion is opened away from the valve seat, the working liquid is transferred to the annular passage and the head. It is good to flow toward the pressurization supply means through the valve seat spaced apart from the part.

  In these cases, the reservoir is reciprocally disposed in the housing and cooperates with the housing to define the reservoir chamber, and the volume of the reservoir chamber is reduced. Piston biasing means for biasing the reservoir piston in the direction may be provided. In this case, the reservoir piston has a portion that functions as the valve opening means, and the range in which the piston biasing means biases the reservoir piston is related to the range in which the reservoir piston reciprocates. It is preferable to provide an urging restriction means for restricting a portion functioning as a range in which the on-off valve is not opened. Further, when the on-off valve is in a closed state and the biasing limiting means limits the biasing of the piston biasing means with respect to the reservoir piston, the pressurization supply to the reservoir chamber When the suction pressure of the means acts, the reservoir piston may be displaced in a direction to open the on-off valve.

  According to these, since the valve opening means is driven by the suction pressure of the pressure supply means and the normally closed communication control valve, specifically, the on-off valve is opened, the pressure supply means is driven. The on-off valve can be opened via the valve opening means. Further, the pressure of the working liquid that flows from the master cylinder to the pressurizing supply means when the on-off valve is in the open state can be applied in a direction to open the on-off valve. For this reason, if the on-off valve is open, the open state is stably maintained by the flow of the working liquid. For example, the drive of the valve opening means becomes unstable due to a pressure change in the reservoir chamber. Even if it becomes, it can prevent effectively that hunting generate | occur | produces in an on-off valve (communication control valve). Therefore, the pressurized supply means can stably supply the working liquid to the wheel cylinder, and stable braking control is possible.

  Further, since the poppet shape can be adopted as the valve element of the on-off valve, the on-off valve can be opened away from the valve seat only by slightly moving the head portion in the valve opening direction. Thereby, the on-off valve can be efficiently opened and closed by the suction pressure of the pressure supply means. Further, since the spool portion is supported by the valve housing so as to be able to reciprocate, the movement of the head portion in the opening / closing direction can be stabilized. Therefore, the opening / closing of the on-off valve due to the suction pressure of the pressurizing supply means can be stabilized.

  Further, an annular passage communicating with the master cylinder can be formed in the spool portion, and the working liquid can be supplied to the pressurizing supply means through a valve seat in which the annular passage and the head portion are separated. Accordingly, the pressure accompanying the flow of the working liquid can be reliably applied in the direction in which the head portion is separated from the valve seat, that is, in the direction in which the on-off valve is opened, thereby effectively preventing the occurrence of hunting. Can do.

  Further, by providing the urging restriction means, it is possible to appropriately restrict the range in which the piston urging means urges the reservoir piston. Thereby, the position of the reservoir piston at the time of non-braking can be set to a predetermined position, and the reciprocation of the reservoir piston can be stabilized as compared with the case where the biasing limiting means is not provided.

  Further, even in the case where the urging restriction means is provided as described above, in a situation where the on-off valve is in a closed state and the urging restriction means restricts the urging of the piston urging means to the reservoir piston. When the suction pressure of the pressurized supply means acts on the reservoir chamber, the reservoir piston can be displaced in a direction to open the on-off valve. Therefore, the valve opening means can be driven by the suction pressure of the pressure supply means, and the on-off valve can be opened reliably.

1 is a schematic configuration diagram schematically illustrating a configuration of a vehicle braking device according to an embodiment of the present invention. It is the schematic for demonstrating the action | operation of the communication control valve of FIG.

  Hereinafter, a vehicle braking device according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows a system configuration of a vehicular braking apparatus 10 including a communication control valve that is a poppet type on-off valve according to the present embodiment.

  As shown in FIG. 1, the vehicle braking apparatus 10 includes a master cylinder 14 having a master cylinder chamber 12. The piston 14A of the master cylinder 14 is connected to the brake pedal 16, and the hydraulic pressure (hereinafter referred to as master cylinder pressure Pm) corresponding to the driver's stepping force in response to the driver's depression operation of the brake pedal 16 is the master cylinder. It is generated in the chamber 12. Although not shown, the master cylinder 14 may include a known booster that increases the pressure in the master cylinder chamber 12 as compared with the depression force applied to the brake pedal 16.

  One end of a master conduit 18 is connected to the master cylinder chamber 12, and the other end of the master conduit 18 is connected to a communication control valve 20. The communication control valve 20 is a normally closed check valve having a poppet type valve element 22. The valve element 22 is formed of a large-diameter, substantially hemispherical head portion 22A, and a small-diameter spool portion 22B extending integrally from the hemispherical portion with respect to the head portion 22A. An annular passage 24 is formed in the spool portion 22 </ b> B and communicates with the other end of the master conduit 18.

  Further, the housing of the communication control valve 20 is integrated with the housing 28 of the reservoir 26, whereby the communication control valve 20 and the reservoir 26 are assembled to the vehicle brake device 10 as one unit. A valve housing member 30 is disposed in the housing 28 in a state of being fixed in alignment with the axis 32 of the communication control valve 20 by press-fitting, for example, and forms a valve chamber 34 in cooperation with the housing 28. Yes. The valve housing member 30 has a conical valve seat 30A that is loosely fitted to the head portion 22A of the valve element 22, and a through hole 30B that supports the spool portion 22B of the valve element 22 so that the spool portion 22B can be inserted along the axis 32. doing. Here, the head portion 22A of the valve element 22 is urged against the valve seat 30A by a compression coil spring 36 as a valve element urging means elastically mounted between the end face of the housing 28. Yes. As a result, the communication control valve 20 is normally closed when the head portion 22A of the valve element 22 contacts the valve seat 30A. Further, the valve housing member 30 is formed with a radial passage 30C formed in the housing 28 and connected to the inner passage connected to the master conduit 18 and the annular passage 24, and is formed in the housing 28 and will be described later. A radial passage 30 </ b> D that connects the internal passage connected to the oil suction conduit 72 and the valve chamber 34 is formed.

  A cylinder bore 28 </ b> A is formed in the housing 28 of the reservoir 26, and a reservoir piston 38 is disposed in the cylinder bore 28 </ b> A so as to reciprocate along the axis 32. The reservoir piston 38 is formed in a substantially cylindrical shape, and cooperates with the housing 28 to define a variable volume reservoir chamber 40. Further, a protrusion 38B that extends along the axis 32 toward the communication control valve 20 and contacts the end of the spool portion 22B of the valve element 22 is integrally formed on the disk portion 38A of the reservoir piston 38. Yes. Here, the length of the protrusion 38B is set to such a length that the front end of the protrusion 38B abuts without pressing the end of the spool 22B during non-braking.

  An end cap 42 is fixed to the end of the cylinder bore 28A on the side opposite to the reservoir chamber 40 with respect to the reservoir piston 38 by, for example, press-fitting or screwing. A compression coil spring 44 as a piston urging means is elastically mounted between the reservoir piston 38 and the end cap 42, and the reservoir piston 38 has an axis line in a direction in which the volume of the reservoir chamber 40 decreases by the compression coil spring 44. 32 is urged along. The reservoir piston 38 and the end cap 42 cooperate with the housing 28 to define an air chamber 46 having a variable volume, and the air chamber 46 is opened to the atmosphere through a communication hole (not shown).

  Here, between the reservoir piston 38 and the end cap 42, an urging restriction device 50 is arranged as an urging restriction means for restricting the urging of the compression coil spring 44 against the reservoir piston 38. In the bias limiting device 50, the rib portion 52A of the cup-shaped member 52 abuts on the inner surface of the disk portion 38A of the reservoir piston 38, and the tip portion of the shaft portion 54 extends through the raised portion 42A of the end cap 42. The nut 56 is fixed to the end cap 42. The compression coil spring 44 is elastically mounted between the rim portion 52 </ b> A of the cup-shaped member 52 and the base portion 42 </ b> B of the end cap 42. With this configuration, in the bias limiting device 50, in a situation where the amount of oil in the reservoir chamber 40 increases and the reservoir piston 38 is pushed down, the cup-type member 52 moves along the axis 32 with respect to the shaft portion 54 and the end cap 42. The cup-shaped member 52 slides in the direction of the communication control valve 20 along the axis 32 with respect to the shaft portion 54 when the amount of oil in the reservoir chamber 40 is reduced. The reservoir piston 38 can be pushed up to a predetermined position.

  The valve chamber 34 and the reservoir chamber 40 are filled with oil as a working liquid. For this reason, although description is abbreviate | omitted, the code | symbol 60-68 shown in FIG. 1 has shown the seal ring which prevents the leakage of the oil between each corresponding member, respectively. In FIG. 1, reference numeral 70 denotes a master cylinder reservoir that supplies oil to the master cylinder chamber 12 as needed.

  As shown in FIG. 1, one end of an oil suction conduit 72 is connected to the valve chamber 34 and the reservoir chamber 40 through an internal passage formed in the housing 28, and the other end of the oil suction conduit 72 is connected to an electric motor (not shown). It is connected to the suction side of an oil pump 74 as a pressurized supply means to be driven. The oil pump 74 is controlled by controlling the drive current to the motor by an electronic control device (not shown).

  An oil supply conduit 76 is connected to the discharge side of the oil pump 74, and one end of an oil supply / discharge conduit 78 is connected to the oil supply conduit 76. The other end of the oil supply / discharge conduit 78 is connected to the wheel cylinder 80, and a normally open type electromagnetic opening / closing valve 82 serving as a pressure increase control valve for controlling the supply of oil to the wheel cylinder 80 is provided in the middle of the oil supply / discharge conduit 78. Is provided. Connected to the oil supply / discharge conduits 78 on both sides of the electromagnetic on-off valve 82 are check bypass conduits 84 that allow only the flow of oil from the wheel cylinder 80 toward the oil supply conduit 76.

  One end of an oil discharge conduit 86 is connected to the oil supply / discharge conduit 78 between the electromagnetic on-off valve 82 and the wheel cylinder 80, and the other end of the oil discharge conduit 86 is an oil intake conduit between the reservoir 26 and the oil pump 74. 72. In the middle of the oil discharge conduit 86, a normally closed electromagnetic on-off valve 88 is provided as a pressure reducing control valve for controlling the discharge of oil from the wheel cylinder 80. Opening and closing of the electromagnetic open / close valve 82 and the electromagnetic open / close valve 88 is achieved by controlling a control current for each solenoid (not shown) by an electronic control unit.

  One end of a connection conduit 90 is connected to the oil supply conduit 76, and the other end of the connection conduit 90 is connected to the master conduit 18. A linear solenoid valve 92 having a well-known configuration is provided in the middle of the connecting conduit 90. The linear solenoid valve 92 allows only the flow of oil from the oil supply conduit 76 side to the master conduit 18 side at normal times, and the drive current for the solenoid (not shown) is controlled by the electronic control unit so as to be linear. The differential pressure across the solenoid valve 92 (ie, the differential pressure at which the oil supply conduit 76 side is higher than the connection conduit 90 side) is controlled.

  Connected to the connecting conduits 90 on both sides of the linear solenoid valve 92 are non-return bypass conduits 94 that allow only the flow of oil from the master conduit 18 toward the oil supply conduit 76. A pressure sensor 96 is connected to the connection conduit 90 between the linear solenoid valve 92 and the master conduit 18, and the pressure sensor 96 detects the pressure in the connection conduit 90 as the master cylinder pressure Pm. Yes. Thus, the linear solenoid valve 92 and the check bypass conduit 94 block the flow of oil from the wheel cylinder 80 to the master cylinder 14 as necessary, and control the differential pressure across the linear solenoid valve 92 as necessary. Functions as a shutoff valve.

  Although not shown in FIG. 1, the oil supply / discharge conduit 78, the oil discharge conduit 86, the wheel cylinder 80, the electromagnetic on-off valves 82 and 88, the check bypass conduit 84, and the like are provided corresponding to each wheel. Needless to say. The linear solenoid valve 92 and the check bypass conduit 94 may also be provided corresponding to each wheel, but the vehicle braking device 10 is a front wheel system corresponding to the left and right front wheels and a rear wheel system corresponding to the left and right rear wheels. Are provided with a linear solenoid valve 92 and a check bypass conduit 94 for the front wheel system and the rear wheel system, and the vehicle brake device 10 is provided on the left front wheel and the right rear wheel. In the case of a two-system braking device comprising a corresponding first system and a second system corresponding to the right front wheel and the left rear wheel, linear solenoid valves 92 and check bypass for the first system and the second system A conduit 94 may be provided.

  Next, the operation of the vehicular braking apparatus 10 configured as described above will be described for each case of braking start, normal braking, anti-skid control (hereinafter referred to as ABS control), and automatic braking.

(1) When braking is started Even when a braking operation is started by the driver, no drive current is supplied to the electric motor of the oil pump 74, and no control current is supplied to the electromagnetic on-off valves 82 and 88 and the linear solenoid valve 92. Accordingly, since the oil pump 74 is not driven, the communication control valve 20 is maintained in the closed state shown in FIG. 1, the electromagnetic on-off valve 82 is maintained in the open state, and the electromagnetic on-off valve 88 is maintained in the closed state. The As a result, all the oil flowing out from the master cylinder chamber 12 to the master conduit 18 is supplied to the wheel cylinder 80 via the check bypass conduit 94 and the electromagnetic on-off valve 82, and the pressure in the wheel cylinder 80 is efficiently increased. Can do.

(2) During normal braking Even when the braking operation is performed by the driver but the ABS control is not performed, the drive current is not supplied to the motor of the oil pump 74 and the electromagnetic on-off valve 82 is not supplied. , 88 and the linear solenoid valve 92 are not supplied with a control current. As a result, the master cylinder chamber 12 and the wheel cylinder 80 are maintained in communication with each other via the check bypass conduit 94 and the electromagnetic on-off valve 82, so that the pressure in the wheel cylinder 80 is maintained at the master cylinder chamber 12. It is controlled to the same pressure as the internal pressure.

(3) At the time of ABS control When the braking slip of the wheel becomes excessive due to the excessive braking operation amount by the driver, the ABS control for reducing the braking slip of the wheel is performed. In this ABS control, since the pressure in the wheel cylinder 80 needs to be controlled independently of the pressure in the master cylinder chamber 12, if the well-known ABS control start condition is satisfied, the ABS control start condition is also satisfied. Until then, the drive current is supplied to the electric motor of the oil pump 74, and the solenoid on / off valves 82 and 88 are opened and closed according to the braking slip rate or the braking slip amount of the wheel without supplying the control current to the solenoid of the linear solenoid valve 92. Is done. As a result, the pressure in the wheel cylinder 80 is increased or decreased so as to be a value corresponding to the master cylinder pressure Pm and required to suppress the braking slip of the wheel, and the braking slip of the wheel is reduced.

  In this case, the ABS control is started by first reducing the pressure in the wheel cylinder 80. At this time, since the oil in the wheel cylinder 80 flows into the reservoir chamber 40 through the electromagnetic on-off valve 88 switched to the valve open state, the amount of oil in the reservoir chamber 40 temporarily increases. On the other hand, when the pressure in the wheel cylinder 80 is increased, the oil is sucked from the reservoir chamber 40 through the oil suction conduit 72 by the oil pump 74, so that the amount of oil in the reservoir chamber 40 decreases. However, even when the amount of oil in the reservoir chamber 40 decreases in this way, the amount of oil in the reservoir chamber 40 does not become smaller than the amount during normal braking where ABS control is not performed. The valve element 22 of the communication control valve 20 is not opened by the reservoir piston 38 and is kept closed.

  In addition, when hydro assist brake control is performed in which the pressure in the wheel cylinder 80 is higher than the master cylinder pressure Pm and is increased or decreased in response to the increase or decrease in the master cylinder pressure Pm, the wheel cylinder of each wheel is controlled. A control current is applied to the solenoid of the linear solenoid valve 92 so that the pressure in 80 becomes the target wheel cylinder pressure based on the master cylinder pressure Pm, and the oil pump 74 is driven in accordance with the differential pressure control by the linear solenoid valve 92. .

(4) At the time of automatic braking When automatic braking such as vehicle behavior control, auto cruise control, and inter-vehicle distance control by controlling at least braking force is performed, a drive current is applied to the electric motor of the oil pump 74 and linear A control current is applied to the solenoid of the linear solenoid valve 92 so that the differential pressure across the solenoid valve 92 becomes a predetermined value based on a target pressure in the wheel cylinder 80 required by automatic braking, for example. The electromagnetic on-off valves 82 and 88 are opened and closed so that the pressure in the wheel cylinder 80 becomes the target pressure. Thereby, automatic braking can be achieved.

  In this case, since the amount of oil sucked from the reservoir chamber 40 by the oil pump 74 is large, that is, a negative pressure is generated in the oil suction conduit 72, the pressure in the reservoir chamber 40 is maintained during normal braking or ABS control. Less than. Thus, in the situation where the pressure in the reservoir chamber 40 decreases, the communication control valve 20 changes from the closed state to the open state. Hereinafter, the transition from the closed state to the open state of the communication control valve 20 will be specifically described.

  When the pressure in the reservoir chamber 40 decreases, the reservoir piston 38 is displaced along the axis 32 toward the communication control valve 20 relative to the housing 28 as shown in FIG. Thereby, in the reservoir piston 38, the disk part 38A is disengaged from the rim part 52A of the cup-type member 52 of the urging restriction device 50, and the protrusion 38B constitutes the valve element 22 of the communication control valve 20 at its tip. The end of the spool portion 22B is pressed. When the protrusion 38B of the reservoir piston 38 presses the end of the spool portion 22B against the spring force of the compression coil spring 36, the head portion 22A of the valve element 22 is a valve seat 30A formed on the valve housing member 30. Separate from. That is, the reservoir piston 38 functions as a valve opening means that opens the communication control valve 20 by being driven by a decrease in the pressure in the reservoir chamber 40.

  When the head portion 22A and the spool portion 22B of the valve element 22 are displaced along the axis 32, the oil in the master cylinder chamber 12 is transferred to the master conduit 18, the internal passage, and the valve housing as indicated by the thick arrow in FIG. The oil that flows into the valve chamber 34 through the radial passage 30C formed in the member 30 and the annular passage 24 formed in the spool portion 22B, and the oil that flows into the valve chamber 34 is formed in the valve housing member 30. Suction (suction) is performed by the oil pump 74 via the radial passage 30 </ b> D, the internal passage, and the oil suction conduit 72.

  At this time, the pressure of the oil flowing from the master cylinder 14 toward the oil pump 74 as the oil is sucked (suctioned) by the oil pump 74 causes the head portion 22A of the valve element 22 to move through the valve seat 30A as shown in FIG. In other words, the communication control valve 20 is opened. Thereby, when the oil pump 74 sucks (suctions) oil from the master cylinder 14 via the communication control valve 20, for example, the drive of the reservoir piston 38 becomes unstable due to a pressure change in the reservoir chamber 40. Even in this case, the head portion 22A of the valve element 22 can be stably separated from the valve seat 30A, that is, the communication control valve 20 can be stably maintained in the open state. Therefore, even when the oil pump 74 sucks (sucks) oil from the master cylinder 14, the communication control valve 20 is repeatedly opened and closed as the oil flows, so-called Hunting can be reliably prevented. As a result, oil can be stably supplied to the oil pump 74, and the pressure in the wheel cylinder 80 can be appropriately controlled.

  At the end of automatic braking, surplus oil in the vehicle braking device 10 is returned to the master cylinder reservoir 70 via the connection conduit 90 by opening the linear solenoid valve 92.

  As can be understood from the above description, when the reservoir piston 38 is driven by the suction pressure of the oil pump 74, the normally closed communication control valve 20, specifically, the head portion 22A of the valve element 22 is moved to the valve seat. Since the valve is opened away from 30A, the communication control valve 20 can be opened via the reservoir piston 38 when the oil pump 74 is driven. As a result, the opening timing of the communication control valve 20 can be adjusted by setting the relationship between the spool portion 22B of the valve element 22 and the protrusion 38B of the reservoir piston 38. Further, when the communication control valve 20 is in the open state, the oil that flows from the master cylinder 14 (more specifically, the master cylinder chamber 12 via the master conduit 18) to the oil pump 74 via the oil suction conduit 72. Can be applied in a direction in which the communication control valve 20 is opened, specifically, in a direction in which the head portion 22A of the valve element 22 is separated from the valve seat 30A. For this reason, if the communication control valve 20 is opened, the valve opening state is stably maintained by the flow of oil. For example, the reservoir piston 38 is driven due to a pressure change in the reservoir chamber 40. Even if it becomes unstable, it is possible to effectively prevent hunting from occurring in the communication control valve 20. Therefore, the oil pump 74 can stably supply oil to the wheel cylinder 80, and stable braking control is possible.

  Further, since the poppet shape can be adopted as the valve element 22 of the communication control valve 20, the communication control valve 20 is opened only by moving the head portion 22A slightly in the valve opening direction away from the valve seat 30A. Can do. Thereby, the communication control valve 20 can be efficiently opened and closed by the suction pressure of the oil pump 74. Further, since the spool portion 22B is supported by the through hole 30B formed in the valve housing 30 so as to be able to reciprocate, it is possible to stabilize the movement of the head portion 22A toward or away from the valve seat 30A. Therefore, the opening and closing of the communication control valve 20 due to the suction pressure of the oil pump 74 can be stabilized.

  An annular passage 24 communicating with the master cylinder 14 can be formed in the spool portion 22B, and oil can be supplied to the oil pump 74 via the valve seat 30A in which the annular passage 24 and the head portion 22A are separated. . Thereby, the pressure accompanying the flow of oil can be reliably applied in the direction in which the head portion 22A is separated from the valve seat 30A, so that occurrence of hunting can be effectively prevented.

  Further, by providing the biasing restriction device 50, the range in which the compression coil spring 44 biases the reservoir piston 38 can be appropriately limited. Thereby, the position of the reservoir piston 38 at the time of non-braking can be set to a predetermined position, and the reciprocation of the reservoir piston 38 can be stabilized as compared with the case where the urging restriction device 50 is not provided. .

  Further, even when the urging restriction device 50 is provided as described above, the communication control valve 20 is in the closed state, and the urging restriction device 50 restricts the urging of the compression coil spring 44 against the reservoir piston 38. In this situation, when the suction pressure of the oil pump 74 acts on the reservoir chamber 40, the reservoir piston 38 may be displaced in the direction of opening the communication control valve 20, that is, in the direction of separating the head portion 22A from the valve seat 30A. it can. Therefore, the reservoir piston 38 can be driven by the suction pressure of the oil pump 74, and the communication control valve 20 can be opened reliably.

  The implementation of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the object of the present invention.

  For example, in the said embodiment, it implemented as an on-off valve (check valve) which employ | adopted the poppet type valve element 22 as the communication control valve 20. FIG. In this case, at least when the pressure in the reservoir chamber decreases, the normally closed communication control valve can be opened, and the pressure of the oil flowing through the communication control valve can be applied in the direction of separating from the valve seat. Any type of opening / closing valve (check valve) may be employed. In this case, for example, a ball type check valve or a spool type check valve can be employed.

  In the above embodiment, the urging restriction device 50 is configured using the slidable cup-type member 52. However, as long as the urging of the compression coil spring 44 to the reservoir piston 38 can be restricted, any one may be used, and further, the urging restriction device 50 may be omitted.

  In the above-described embodiment, the protrusion 38B formed on the reservoir piston 38 is slightly spaced from the end of the spool portion 22B of the valve element 22 during non-braking and comes into contact without pressing. In this case, for example, an elastic material may be provided between the tip of the protrusion 38B and the end of the spool portion 22B.

  Further, in the above-described embodiment, the linear solenoid valve 92 and the check bypass that allow only the oil flow from the oil supply conduit 76 side to the master conduit 18 side during normal operation and control the differential pressure by controlling the control current. Conducted with conduit 94. However, in the situation where the oil pump 74 is driven, any configuration is possible as long as the communication between the master cylinder and the wheel cylinder is cut off and the oil can be circulated from the wheel cylinder side to the master cylinder side as necessary. It may be adopted.

DESCRIPTION OF SYMBOLS 10 ... Vehicle brake device, 14 ... Master cylinder, 20 ... Communication control valve, 22 ... Valve element (poppet type), 22A ... Head part, 22B ... Spool part, 24 ... Annular passage, 26 ... Reservoir, 36 ... Compression coil Spring, 38 ... reservoir piston, 40 ... reservoir chamber, 44 ... compression coil spring, 50 ... bias limiter, 74 ... oil pump, 80 ... wheel cylinder, 82, 88 ... electromagnetic on-off valve, 92 ... linear solenoid valve, 96 ... Pressure sensor

Claims (7)

A shut-off valve that shuts off the flow of the working liquid from the wheel cylinder to the master cylinder as necessary, an increase / decrease control valve that increases / decreases the pressure in the wheel cylinder, and the increase / decrease control valve A reservoir for receiving and storing the working liquid from the wheel cylinder in the reservoir chamber; and at least when the working pressure is sucked and pressurized from the reservoir chamber and the pressure increasing / decreasing control valve is in the pressure increasing position, A vehicular braking device comprising a pressure supply means for supplying a working liquid to the wheel cylinder, and a communication control valve for controlling communication between the master cylinder and the pressure supply means,
The communication control valve has a normally closed on-off valve and a valve-opening means that is driven by the suction pressure of the pressurizing supply means to open the on-off valve. The valve-opening means opens the on-off valve. And the pressure of the working fluid flowing from the master cylinder toward the pressurizing supply means acts in a direction to open the on-off valve. The vehicle braking device according to claim 1,
The on-off valve has a valve element and valve element urging means for urging the valve element against a valve seat, and the valve element abuts on the valve seat by urging by the valve element urging means. A vehicular braking device, wherein the check valve is closed and the valve element is opened away from the valve seat by driving of the valve opening means. The vehicle braking device according to claim 2,
The valve element has a poppet shape having a head part and a spool part having a smaller diameter than the head part, and is supported by the valve housing so as to be reciprocable by the spool part, and the head part is urged by the valve element. Brake for a vehicle, wherein the valve seat is brought into contact with the valve seat by urging of the valve and closed, and the head portion is opened away from the valve seat by pressing of the spool portion by driving of the valve opening means. apparatus. The vehicle braking device according to claim 3,
The spool portion is formed with an annular passage communicating with the master cylinder, and when the head portion is opened away from the valve seat, the working liquid is separated from the annular passage and the head portion. A vehicular braking device that flows toward the pressurizing supply means via a valve seat. The vehicle braking device according to any one of claims 1 to 4, wherein:
The reservoir is reciprocally disposed in the housing, and cooperates with the housing to define the reservoir chamber, and urges the reservoir piston in a direction in which the volume of the reservoir chamber decreases. And a piston urging means. The vehicle braking device according to claim 5,
The reservoir piston has a portion that functions as the valve opening means,
An urging restriction means for restricting a range in which the piston urging means urges the reservoir piston to a range in which a portion functioning as the valve opening means does not open the on-off valve with respect to a range in which the reservoir piston reciprocates; The vehicle braking device according to claim 5, wherein the vehicle braking device is provided. The vehicle braking device according to claim 6,
When the on-off valve is in a closed state and the biasing limiting means limits the biasing of the piston biasing means with respect to the reservoir piston, When the suction pressure acts, the reservoir piston is displaced in a direction to open the on-off valve.

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