JP4449433B2 - Brake hydraulic pressure generator for vehicles - Google Patents

Description

  The present invention relates to a vehicle brake hydraulic pressure generator, and more particularly to a vehicle brake hydraulic pressure generator provided with a stroke simulator.

  Various types of vehicle brake hydraulic pressure generators equipped with a stroke simulator are known. Usually, a hydraulic pressure source including a hydraulic pressure source is used to control the hydraulic pressure source according to the operation of the brake operating member. Regulates the hydraulic pressure and supplies it to the wheel cylinder, shuts off the communication between the master cylinder and the wheel cylinder, and connects the master cylinder to the wheel cylinder when the hydraulic pressure control means is abnormal. The hydraulic pressure according to the operating force of the brake operating member is supplied to the wheel cylinder.

  The first master liquid is slidably accommodated in the cylinder housing and moved back and forth in conjunction with the brake operation member, and the first piston is slidably accommodated in the cylinder housing. A pressure chamber is formed, and a second piston that forms a second master hydraulic pressure chamber between the pressure chamber and the cylinder housing communicates with the first master hydraulic pressure chamber in accordance with an output hydraulic pressure of the first master hydraulic pressure chamber. A stroke simulator that absorbs the liquid volume and applies a stroke corresponding to the operating force of the brake operating member to the first piston, and is configured to selectively switch the operation / non-operation of the stroke simulator by the switching means. Things are known.

  In such an apparatus, in order to obtain a good brake feeling when the hydraulic pressure control means is normal, an abnormality occurs in the switching means and the hydraulic pressure is supplied from the first master hydraulic pressure chamber to the stroke simulator. In order to be able to supply the wheel cylinder with the minimum amount of fluid necessary to stop the vehicle when the fluid pressure control means is abnormal even if the fluid pressure control means cannot be shut off, the maximum stroke of the first piston relative to the second piston is increased. It is desirable to set it sufficiently large. For example, it is understood that it is set as such in Patent Document 1 below.

JP 2001-526150 A

  By the way, in general, so-called air bleeding work is performed to remove air mixed in brake fluid in the brake fluid pressure system. When the brake operation is performed with force, it is necessary to prevent the brake operation member from interfering with the floor of the vehicle. For this reason, when the maximum stroke of the first piston relative to the second piston is set as described above as described in Patent Document 1, the maximum stroke of the second piston relative to the cylinder housing is the hydraulic pressure control means. It can only be set to such an extent that the minimum amount of fluid required to stop the vehicle in the event of an abnormality is supplied to the wheel cylinder.

  For this reason, when the hydraulic pressure control means is abnormal, if the switching means operates normally, a sufficient amount of liquid can be supplied to the wheel cylinder connected to the first master hydraulic pressure chamber to obtain a large braking force. However, the wheel cylinder connected to the second master hydraulic pressure chamber can supply only the minimum amount of fluid necessary to stop the vehicle, and there is room for further improvement in terms of maintaining the stability of the vehicle.

  Therefore, the present invention provides a vehicle brake hydraulic pressure generator equipped with a stroke simulator, which can ensure a good brake feeling when the hydraulic pressure control means disposed in the brake hydraulic pressure system is normal, and can control the hydraulic pressure. An object of the present invention is to provide a vehicular brake hydraulic pressure generator capable of supplying a sufficient amount of fluid to a wheel cylinder to obtain a large braking force when the means is abnormal.

In order to achieve the above object, the present invention provides a first piston that is slidably accommodated in a cylinder housing and moves back and forth in conjunction with a brake operation member, and the cylinder housing. A second piston that is slidably received in the first piston and forms a first master hydraulic chamber with the first piston, and a second master hydraulic chamber with the cylinder housing; The first master hydraulic chamber communicates with the first master hydraulic chamber, absorbs the amount of fluid corresponding to the output hydraulic pressure of the first master hydraulic chamber, and applies a stroke corresponding to the operating force of the brake operating member to the first piston. In a vehicular brake hydraulic pressure generating device including a stroke simulator and switching means for selectively switching between operation and non-operation of the stroke simulator, the first for the cylinder housing is provided. The maximum stroke of the piston, with a value smaller than the sum of the maximum stroke of the first piston to the maximum stroke of the second piston relative to the cylinder housing to the second piston and the first piston to said second piston Stroke restricting means for restricting to a value larger than the maximum stroke is provided.

According to a second aspect of the present invention, the first piston is slidably accommodated in the cylinder housing and moved back and forth in conjunction with the brake operation member, and is slidable in the cylinder housing. A second piston that is housed to form a first master hydraulic chamber between the first piston and a second master hydraulic chamber between the cylinder housing and the second master hydraulic chamber. A stroke simulator that absorbs a fluid amount corresponding to an output fluid pressure of the second master fluid pressure chamber and applies a stroke corresponding to an operation force of the brake operation member to the second piston, and the stroke In a vehicular brake hydraulic pressure generator having switching means for selectively switching operation / non-operation of a simulator, a maximum stroke of the first piston relative to the cylinder housing is provided. The click, at a value smaller than the sum of the maximum stroke of the first piston to the maximum stroke of the second piston relative to the cylinder housing to the second piston, than and the maximum stroke of the second piston relative to the cylinder housing It may be provided with a stroke restricting means for restricting to a large value .

In the vehicular brake hydraulic pressure generating device, as described in claim 3, the stroke restricting means sets a maximum stroke of the second piston relative to the cylinder housing to a maximum stroke of the first piston relative to the cylinder housing. It should be larger than half . Further, in the vehicle brake hydraulic pressure generating device according to claim 2, the stroke restricting means, as set forth in claim 4, allows the maximum stroke of the second piston relative to the first piston to be determined relative to the cylinder housing. It may be larger than half of the maximum stroke of the first piston.

According to a fifth aspect of the present invention, the stroke restriction means includes a restriction stroke setting means for adjusting a maximum stroke of the first piston relative to the cylinder housing, and the restriction stroke setting means includes the first restriction stroke setting means. A piston stopper fixed to one piston may be provided. The restriction stroke setting means includes a piston stopper fixed to the first piston and an extension of the cylinder housing from the brake operation member side end to the brake operation member side. A stopper that contacts the piston stopper may be provided.

Since this invention is comprised as mentioned above, there exist the following effects. That is, in the apparatus provided with the stroke restricting means according to claims 1 to 4 , a good brake feeling can be secured when the hydraulic pressure control means is normal, and an abnormality occurs in the switching means. Even if the hydraulic pressure supply from the first master hydraulic chamber or the second master hydraulic chamber to the stroke simulator cannot be cut off, the minimum amount of fluid required to stop the vehicle when the hydraulic control means is abnormal Even if the maximum stroke of the 1st master hydraulic chamber or the 2nd master hydraulic chamber is set so that it can be supplied to the cylinder, the brake operation is performed with a strong operating force when performing air venting or when the hydraulic control means is abnormal. In this case, the stroke restricting means can prevent the brake operating member from interfering with the vehicle floor or the like. Sufficient liquid volume to obtain a large braking force when the abnormality may be configured to supply to the wheel cylinder. Therefore, when the fluid pressure control means is abnormal, a sufficient amount of fluid to obtain a large braking force can be supplied to the wheel cylinder almost evenly, so that the stability of the vehicle can be reliably maintained and the reliability can be improved. improves.

And if the said stroke control means is provided with the control stroke setting means as described in Claim 5 , it can set the control stroke for every vehicle type easily. If this restriction stroke setting means is configured as described in claim 6 , it is possible to easily adjust the restriction stroke for each vehicle type, resulting in an inexpensive apparatus.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the vehicular brake hydraulic pressure generator according to the present embodiment includes a master piston MP1, which is a first piston of the present invention, slidably accommodated in a cylinder housing (hereinafter simply referred to as a housing) HS. The brake pedal BP which is a brake operation member is connected. Further, the master piston MP2 as the second piston of the present invention is slidably accommodated in the housing HS, and a first master hydraulic chamber C1 is formed between the master piston MP1 and the housing HS. A second master hydraulic pressure chamber C2 is formed in the second. The first master hydraulic chamber C1 is provided with a stroke simulator AB that absorbs the amount of fluid corresponding to the output hydraulic pressure and applies a stroke corresponding to the operating force of the brake pedal BP to the master piston MP1. .

  The housing HS is a bottomed cylindrical body whose front (left side in FIG. 1) is closed, and a cylinder hole (a stepped hole including a recess B1, a small diameter hole B2, a large diameter hole B3, a small diameter hole B4, and a large diameter hole B5). Cylinder bore) is formed, and a screw groove is formed on the inner surface of the rear opening end B6. An annular groove for accommodating the annular seal members S1 to S5 having a cup-shaped cross section is formed on the inner surface of the cylinder hole. An atmospheric pressure chamber C3 is formed between the seal members S1 and S2, and the seal An atmospheric pressure chamber C4 is formed between the members S3 and S4. In addition, since these annular grooves and large-diameter holes B3 can be formed by boring along the axis of the housing HS, the housing HS can be constituted by a single metal part.

  Further, on the side surface of the housing HS, ports P0 and P1 that open before and after the seal member S5 in the large-diameter hole B3, a port P2 that opens to the second master hydraulic chamber C2 of the recess B1, and an atmospheric pressure chamber C3. And a port P4 opened to the atmospheric pressure chamber C4. The ports P3 and P4 are connected to an atmospheric pressure reservoir (hereinafter simply referred to as a reservoir) RS.

  On the other hand, the master piston MP1 has a recessed portion M1 that opens forward, and a shaft portion RD that extends rearward. A port P5 that opens to the recessed portion M1 is formed on the side surface of the master piston MP1. . The master piston MP2 has a recess M2 that opens forward, and an annular groove GR having a predetermined width in the axial direction is formed on the outer peripheral surface of the main body. A port P6 that opens to the recess M2 is also formed on the side surface of the master piston MP2. A compression spring E1 functioning as a return spring is mounted between the master pistons MP1 and MP2 via a retainer RT, and the compression spring E2 functioning as a return spring is also provided in the recess M2 of the master piston MP2. Contained.

  When the components having the above-described configuration are described along with an assembly procedure example, first, the seal members S1 to S5 are mounted in the annular groove of the housing HS. Next, the compression spring E2 is accommodated in the recess B1 of the housing HS and the recess M2 of the master piston MP2, and the master piston MP2 is accommodated in the cylinder hole through the seal members S1 and S2 so as to be liquid-tightly slidable. Thus, a second master hydraulic chamber C2 is formed in front of the master piston MP2. Then, in a state where the compression spring E1 is stretched through the retainer RT in the recess M1 of the master piston MP1, the liquid is slidably accommodated in the cylinder hole through the seal members S3 and S4. The first master hydraulic chamber C1 is formed between the master piston MP1 and the master piston MP2. Thereby, it can adjust so that the maximum stroke (D3) of master piston MP1 (1st piston) with respect to master piston MP2 (2nd piston) mentioned later can be ensured.

  In this state where the master pistons MP1 and MP2 are accommodated in the cylinder hole of the housing HS, a nut-shaped stopper NH having a screw groove formed on the outer peripheral surface is screwed into the open end B6, and the compression spring E2 The backward movement of the master pistons MP1 and MP2 due to the urging force is prevented. As a result, the desired port idle (distance until the ports P5 and P6 are closed) is secured and the maximum stroke (D2) of the master piston MP2 (second piston) with respect to the housing HS described later can be secured. can do.

  The maximum stroke (D1) of the master piston MP1 (first piston) with respect to the stopper NH (and consequently the housing HS) is set by the piston stopper NS. The piston stopper NS is composed of a pair of nuts and is screwed into the shaft portion RD behind the master piston MP1, and is configured to be tightened from both sides, for example, so that it can be easily rotated after being fixed at a predetermined position. do not do.

  The distance (D1) between the stopper NH and the piston stopper NS is adjusted so as to have the following relationship with respect to each part having a preset size. That is, the maximum stroke (D1) of the master piston MP1 (first piston) with respect to the housing HS (stopper NH in FIG. 1) is adjusted to the master with respect to the housing HS by adjusting the fixed position of the master piston MP1 with respect to the rear shaft portion RD. A value smaller than the sum of the maximum stroke (D2) of the piston MP (second piston) and the maximum stroke (D3) of the master piston MP1 (first piston) with respect to the master piston MP (second piston) (D1 <(D2 + D3) ). Thus, the restriction stroke setting means is constituted by the piston stopper NS, and the stroke restriction means is constituted by adjusting the dimensional relationship of the respective parts including the piston stopper NS.

Further, it is desirable that the maximum stroke (D2) of the master piston MP2 (second piston) with respect to the housing HS is set to a value larger than half of the maximum stroke (D1) of the master piston MP1 (first piston) with respect to the housing HS. This is because when the restriction stroke is set for each vehicle type, the maximum stroke (D2) of the master piston MP2 with respect to the housing HS is not set for each vehicle type, and when the hydraulic pressure control means (PC in FIG. 2 described later) is abnormal. This is because the maximum amount of fluid that can ensure a large braking force can be supplied to the wheel cylinders (WC1 and WC2 in FIG. 2 described later) .

The maximum stroke (D2) of the master piston MP2 (second piston) and the maximum stroke (D3) of the master piston MP1 (first piston) with respect to the master piston MP2 are the same as those of the master piston M1 (first piston) with respect to the housing HS. A value smaller than the maximum stroke (D1) may be set or a larger value may be set . However, in order to supply the maximum amount of fluid to the wheel cylinder even in the case of an abnormality similar to the above, FIG. As shown, D1 is set to a value larger than D3 .

  Furthermore, in the present embodiment, the amount of fluid corresponding to the output fluid pressure of the first master fluid pressure chamber C1 is absorbed, and a stroke corresponding to the operating force of the brake pedal BP is applied to the master piston MP1 (first piston). A stroke simulator AB is provided. Then, the absorption operation of the stroke simulator AB is performed by the seal member S5 disposed in the large-diameter hole B3 of the housing HS and the annular groove GR formed at a position facing the seal member S5 when the master piston MP2 is in the initial position. And switching means for selectively switching between non-operation and non-operation.

  In the stroke simulator AB, a piston member AP is accommodated in a cylindrical housing AH through a seal member S6 so as to be fluid-tightly slidable, and is pressed toward the hydraulic chamber C5 by a compression spring E3 as an elastic member. It is composed of. In this stroke simulator AB, the gap CL between the seal member S5 and the annular groove GR is maintained until the master piston MP2 moves a predetermined distance (second stroke D5) from the initial position and the outer peripheral surface thereof abuts on the seal member S5. The hydraulic chamber C5 of the stroke simulator AB is configured to communicate with the first master hydraulic chamber C1.

  When assembled as described above, the first master hydraulic chamber C1 and the second master hydraulic chamber C2 are formed in front of the master pistons MP1 and MP2 in the housing HS, respectively, and hydraulic systems are respectively connected from the ports P1 and P2. It is configured to communicate with the wheel cylinders WC1 and WC2 of FIG. 2 via H1 and H2. When the master pistons MP1 and MP2 are in the initial positions shown in FIG. 1, the master hydraulic pressure chambers C1 and C2 communicate with the atmospheric pressure chambers C4 and C3 via the ports P5 and P6, and eventually via the ports P4 and P3. To the atmospheric pressure reservoir RS.

  When the master piston MP2 is at the initial position shown in FIG. 1, the first master hydraulic chamber C1 under atmospheric pressure communicates with the hydraulic chamber C5 of the stroke simulator AB via the gap CL. When the master piston MP2 moves forward from the initial position by a distance equal to or longer than the first stroke D4 (port idle), the opening of the port P6 is shielded by the seal member S1, and the second master hydraulic chamber C2 and the atmospheric pressure chamber C3. Communication with is interrupted. Similarly, when the master piston MP1 moves forward from the initial position by the first stroke D4 (port idle) or more, the opening of the port P5 is shielded by the seal member S3, and the first master hydraulic chamber C1 and the atmospheric pressure chamber C4. Communication with is interrupted.

  As the master piston MP1 moves forward, the piston member AP is pushed against the urging force of the compression spring E3 to expand the hydraulic chamber C5, and a stroke is applied to the master piston MP1. Then, until the master piston MP2 moves from the initial position by a predetermined distance (second stroke D5) and the outer peripheral surface comes into contact with the seal member S5, the hydraulic chamber C5 becomes the first master hydraulic chamber via the gap CL. The stroke simulator AB is configured to operate in communication with C1.

  Accordingly, when the hydraulic pressure control means PC (described later) is normal, the hydraulic systems H1 and H2 are closed (open / close valves NO1 and NO2 (described later) are closed), so that the master piston MP2 has the first stroke D4. From this point, the master piston MP1 only moves forward, and the stroke simulator AB operates as described above. When the hydraulic pressure control means PC is abnormal, the hydraulic pressure systems H1 and H2 are opened (the on-off valves NO1 and NO2 are in the open position), so that the master pistons MP1 and MP2 move forward substantially evenly and the master piston MP1. Is moved forward from the initial position by the second stroke D5 or more, the gap CL is blocked by the seal member S5, and the stroke simulator AB does not operate, and the first master hydraulic pressure is changed according to the forward movement of the master pistons MP1 and MP2. The brake fluid pressure is directly output from the chamber C1 and the second master fluid pressure chamber C2 to the fluid pressure systems H1 and H2.

  The vehicle brake hydraulic pressure generator configured as described above is connected as shown in FIG. 2 to form a vehicle hydraulic brake device. In FIG. 2, a normally-open electromagnetic on-off valve NO1 is interposed in the hydraulic system H1, and connected to a system of wheel cylinders (typically represented by WC1) via the electromagnetic on-off valve NO1 and operated. A hydraulic pressure source PG that generates and outputs a predetermined hydraulic pressure regardless of the person's brake operation is connected. Similarly, a normally open electromagnetic on-off valve NO2 is interposed in the hydraulic system H2, and connected to a wheel cylinder of another system (typically represented by WC2) through this electromagnetic on-off valve NO2. A hydraulic pressure source PG is connected.

  The hydraulic pressure source PG includes an electric motor M controlled by the electronic control unit ECU, and a hydraulic pump HP driven by the electric motor M. The input side is connected to the atmospheric pressure reservoir RS, and the output side is an accumulator. Connected to AC. In the present embodiment, the pressure sensor Sps is connected to the output side, and the detected pressure of the pressure sensor Sps is monitored by the electronic control unit ECU. Based on this monitoring result, the electric motor M is controlled by the electronic control unit ECU so that the hydraulic pressure of the accumulator AC is maintained at a pressure between a predetermined upper limit value and a lower limit value.

  An accumulator AC is connected between the electromagnetic on-off valve NO1 of the hydraulic system H1 and the wheel cylinder WC1 via a normally closed first proportional electromagnetic valve SV1, and the output hydraulic pressure of the hydraulic pressure source PG is The pressure is adjusted and supplied to the wheel cylinder WC1. Further, the electromagnetic on-off valve NO1 and the wheel cylinder WC1 are connected to the atmospheric pressure reservoir RS via a normally closed second proportional electromagnetic valve SV2, and the hydraulic pressure of the wheel cylinder WC1 is reduced and regulated. It is comprised so that. Similarly, an accumulator AC is connected between the electromagnetic on-off valve NO2 of the hydraulic system H2 and the wheel cylinder WC2 via a normally-closed first proportional solenoid valve SV3, and the output hydraulic pressure of the hydraulic pressure source PG. Is regulated and supplied to the wheel cylinder WC2. Further, the electromagnetic on-off valve NO2 and the wheel cylinder WC2 are connected to the atmospheric pressure reservoir RS via a normally closed second proportional electromagnetic valve SV4, and the hydraulic pressure of the wheel cylinder WC2 is reduced and regulated. It is comprised so that. Thus, the hydraulic pressure control means PC is constituted by the hydraulic pressure source PG, the first proportional solenoid valves SV1 and SV3, the second proportional solenoid valves SV2 and SV4, the electronic control unit ECU, the following sensors, and the like.

  In the present embodiment, for example, the pressure sensor Smc is connected to the upstream side of the electromagnetic on-off valve NO2 in the hydraulic system H2, and the pressure sensor Swc is connected to the downstream side and the downstream side of the electromagnetic on-off valve NO1 in the hydraulic system H1. It is connected. The brake pedal BP is provided with a stroke sensor BS for detecting the stroke, and these detection signals are input to the electronic control unit ECU. By these sensors, the output hydraulic pressure of the second master hydraulic chamber C2, the brake hydraulic pressure of the wheel cylinders WC2 and WC1, and the stroke of the brake pedal BP are monitored (the pressure sensor Smc is on the hydraulic system H1 side). Or may be provided in both hydraulic systems). Further, sensors (typically represented by SN) such as wheel speed sensors and acceleration sensors used for various controls such as anti-lock control are provided, and these detection signals are also input to the electronic control unit ECU. It is configured.

  The operation of the hydraulic brake device including the vehicle brake hydraulic pressure generator of the present embodiment having the above-described configuration will be described. First, when the hydraulic pressure control means PC is normal, the electromagnetic on-off valves NO1 and NO2 in FIG. 2 are turned on to shut off the hydraulic pressure systems H1 and H2, and the brake operation amount is based on the detected values of the stroke sensor BS and the pressure sensor Smc. The hydraulic pressure corresponding to is supplied from the hydraulic pressure source PG to the wheel cylinders WC1 and WC2. That is, the output current to the first proportional solenoid valves SV1 and SV3 and the second proportional solenoid valves SV2 and SV4 is appropriately controlled so that the wheel cylinder hydraulic pressure detected by the pressure sensor Swc becomes the target wheel cylinder hydraulic pressure. Is done. Thus, the hydraulic pressure corresponding to the operation of the brake pedal BP is supplied to the wheel cylinders WC1 and WC2 by the hydraulic pressure control means PC.

  In this case, the master piston MP2 (second piston) only moves forward by approximately the port idle amount (first stroke D4), and the communication between the second master hydraulic chamber C2 and the atmospheric pressure chamber C3 is cut off. After that, the master piston MP1 (first piston) hardly moves forward, and only the master piston MP1 (first piston) moves forward. At this time, since the first master hydraulic chamber C1 and the hydraulic chamber C5 communicate with each other through the gap CL between the seal member S5 and the annular groove GR, the stroke simulator AB is operated according to the operation of the brake pedal BP. When the force due to the brake fluid pressure applied to the piston member AP becomes equal to or greater than the attachment load of the compression spring E3, the compression spring E3 is compressed, and a stroke corresponding to the brake operation force is generated in the master piston MP1.

  On the other hand, when an abnormality occurs in the hydraulic pressure control means PC such as the hydraulic pressure source PG, the electromagnetic on-off valves NO1 and NO2 are de-energized (OFF) to the open position, as shown in FIG. The systems H1 and H2 are in communication. Also, the first proportional solenoid valves SV1 and SV3 and the second proportional solenoid valves SV2 and SV4 are also de-energized (OFF) to the closed position, and the hydraulic pressure from the hydraulic pressure source PG with respect to the wheel cylinders WC1 and WC2 Is not supplied. When the brake pedal BP is operated in this state and the master piston MP2 moves forward by a predetermined distance (second stroke D5) or more, the outer peripheral surface comes into contact with the seal member S5, and the first master hydraulic chamber C1 and the stroke simulator AB are The communication with the hydraulic chamber C5 is cut off, and the master piston MP1 (first piston) and the master piston MP2 (second piston) move forward, compressing the first master hydraulic chamber C1 and the second master hydraulic chamber C2, respectively. Will do. Thus, the hydraulic pressure is output to the hydraulic pressure systems H1 and H2 according to the operation of the brake pedal BP.

  Next, the operation when performing a so-called air bleeding operation for removing air mixed in the brake fluid of the brake fluid pressure system will be described. When the brake pedal BP, which is a brake operation member, is depressed with the bleeder plug (not shown) of the wheel cylinder WC1 or WC2 known in the art opened, both the master pistons MP1 and MP2 move forward, but the piston stopper NS Is in contact with the stopper NH screwed to the housing HS, the depression of the brake pedal BP is prevented. Accordingly, it is possible to appropriately prevent the brake pedal BP from interfering with the vehicle floor or the like during the operation of removing the air mixed in the brake fluid. Similarly, when the brake operation is performed with a strong operating force when the hydraulic pressure control means is abnormal, both the master pistons MP1 and MP2 move forward, but the piston stopper NS contacts the stopper NH screwed to the housing HS. When the contact is made, the depression of the brake pedal BP is prevented, so that the brake pedal BP can be appropriately prevented from interfering with the vehicle floor or the like. Further, as described above, the maximum stroke (D2) of the master piston MP2 relative to the housing HS is set to a value larger than half of the maximum stroke (D1) of the master piston MP1 relative to the housing HS. Without setting the maximum stroke (D2) of the master piston MP2, the maximum amount of fluid that can ensure a large braking force can be supplied to the wheel cylinders WC1 and WC2 when the fluid pressure control means PC is abnormal.

  FIG. 3 shows another embodiment of the present invention. Components substantially the same as those in FIG. 1 are denoted by the same reference numerals and are arranged in the same manner as in FIG. In the present embodiment, a stroke simulator AB2 is provided, and a switching valve CH composed of a normally closed electromagnetic on-off valve is provided as a switching means for selectively switching between absorption operation and non-operation of the stroke simulator AB2. The second master hydraulic chamber C2 is connected to the hydraulic chamber C5 of the stroke simulator AB2.

  For this reason, since the annular groove GR of the master piston MP2 in FIG. 1 is not required for the second piston, in the present embodiment, the second piston is the master piston MP3, and the recess is represented by M3. Unlike FIG. 1, a piston stopper NK is fixed to the shaft portion RD of the master piston MP1 (first piston) by press-fitting. As for this piston stopper, as shown in FIG. 4, in either embodiment of FIGS. 1 and 3, the piston stopper NC is deformed and fixed to the shaft portion RD of the master piston MP1 (a caulking portion is formed). Can be fixed in the same manner as in FIG.

  In the stroke simulator AB2 of FIG. 3, a piston member AP2 is accommodated in a cylinder-shaped housing AH2 through a seal member S11 and S12 so as to be slidable in a liquid-tight manner, and is pressed toward the hydraulic chamber C5 by a compression spring E4. It is comprised so that. Further, a control chamber C8 and an atmospheric pressure chamber C9 are formed before and after the seal member S12 of the piston member AP2, and the atmospheric pressure chamber C9 is always connected to the atmospheric pressure reservoir RS, and the initial position of the piston member AP2 is set. Is connected to the atmospheric pressure reservoir RS via the port P7, and the opening of the port P7 is shielded by the seal member S12 in accordance with the movement of the piston member AP2, and the communication between the control chamber C8 and the atmospheric pressure reservoir RS is established. It is configured to be blocked. Further, the control chamber C8 and the atmospheric pressure reservoir RS can be communicated and blocked by the switching valve CH.

  Thus, first, when the hydraulic pressure control means PC of FIG. 2 is normal, the switching valve CH of FIG. 3 is switched to the open position, and the electromagnetic on-off valves NO1 and NO2 of FIG. 2 are turned on (closed position). Communication between the ports P1 and P2 and the wheel cylinders WC1 and WC2 is blocked. In this state, the hydraulic pressure control means PC is controlled in the same manner as in the above-described embodiment, and the hydraulic pressure corresponding to the operation of the brake pedal BP is supplied to the wheel cylinders WC1 and WC2. In this case, since the first master hydraulic chamber C1 is in a sealed state after the master piston MP1 has advanced approximately by the amount of port idle, the master piston MP1 does not substantially move forward with respect to the master piston MP3 and is integrated. Will move forward. On the other hand, in the stroke simulator AB2, the control chamber C8 and the atmospheric pressure reservoir RS communicate with each other via the switching valve CH in the open position, and the control chamber C8 is under atmospheric pressure. Accordingly, in response to the operation of the brake pedal BP, brake fluid pressure is generated in the second master fluid pressure chamber C2 via the master pistons MP1 and MP3, and the force due to the brake fluid pressure applied to the piston member AP2 is compressed spring. If it becomes more than the attachment load of E4, the compression spring E4 will be compressed and the stroke according to brake operation force will arise in piston member AP2 (as a result, master piston MP3 and MP1).

  On the other hand, when an abnormality occurs in the hydraulic pressure control means PC such as the hydraulic pressure source PG, the switching valve CH in FIG. 3 is de-energized and switched to the closed position, and the electromagnetic on-off valves NO1 and NO2 in FIG. Is opened, and the first master hydraulic chamber C1 and the second master hydraulic chamber C2 are in communication with the wheel cylinders WC1 and WC2, respectively, as shown in FIG. Also, the first proportional solenoid valves SV1 and SV3 and the second proportional solenoid valves SV2 and SV4 are also de-energized (OFF) to the closed position, and the hydraulic pressure from the hydraulic pressure source PG with respect to the wheel cylinders WC1 and WC2 Is not supplied. Accordingly, after the piston member AP2 has moved by a distance until the port P7 is closed, the communication between the control chamber C8 and the atmospheric pressure reservoir RS is cut off, and the piston member AP2 does not move even when the brake pedal BP is operated. The master pistons MP1 and MP3 move forward according to the operation of the brake pedal BP, and hydraulic pressure is supplied only from the first master hydraulic chamber C1 and the second master hydraulic chamber C2 to the wheel cylinders WC1 and WC2.

Also in the embodiment of FIG. 3, the maximum stroke (d1) of the master piston MP1 (first piston) relative to the housing HS (stopper NH) is the maximum stroke (d2) of the master piston MP3 (second piston) relative to the housing HS. Is smaller than the sum of the maximum stroke (d3) of the master piston MP1 (first piston) with respect to the master piston MP3 (second piston) (d1 <(d2 + d3)), and d1 is restricted to a value greater than d2. Yes. Further, the maximum stroke (d3) of the master piston MP3 (second piston) with respect to the master piston MP1 (first piston) is half of the maximum stroke (d1) of the master piston MP1 (first piston) with respect to the housing HS (stopper NH). It is desirable to set a larger value .

  Thus, also in the present embodiment, when performing the air bleeding operation to remove the air mixed in the brake fluid of the brake fluid pressure system or when the brake operation is performed with a strong operation force when the fluid pressure control means is abnormal, When the brake pedal BP is depressed, the master piston MP1, which is the first piston, and the master piston MP3, which is the second piston, both move forward, but when the piston stopper NK comes into contact with the stopper NH of the housing HS, the depression of the brake pedal BP is prevented. Therefore, it is possible to appropriately prevent the brake pedal BP from interfering with the vehicle floor or the like. Further, since the maximum stroke (d3) of the master piston MP3 with respect to the master piston MP1 is set to a value larger than half of the maximum stroke (d1) of the master piston MP1 with respect to the housing HS, the master piston for the master piston MP1 for each vehicle type. Without setting the maximum stroke (d3) of MP3, the maximum amount of fluid that can ensure a large braking force can be supplied to the wheel cylinders WC1 and WC2 (FIG. 2) when the fluid pressure control means PC is abnormal. .

It is sectional drawing of the brake hydraulic pressure generator for vehicles which concerns on one Embodiment of this invention. It is a lineblock diagram showing an outline of a hydraulic brake device for vehicles provided with a brake fluid pressure generator for vehicles concerning one embodiment of the present invention. It is sectional drawing of the brake hydraulic pressure generator for vehicles which concerns on other embodiment of this invention. In each embodiment of this invention, it is sectional drawing which shows an example of the piston stopper deform | transformed and fixed to the axial part of a master piston.

Explanation of symbols

HS housing BP Brake pedal MP1, MP2, MP3 Master piston GR Annular groove C1 First master hydraulic chamber C2 Second master hydraulic chamber C3, C4, C9 Atmospheric chamber C5 Hydraulic chamber C8 Control chamber PG Hydraulic source RS Large Pressure reservoir E1, E2, E3, E4 Compression spring AB, AB2 Stroke simulator AP, AP2 Piston member CH Switching valve NO1, NO2 Solenoid open / close valve SV1, SV3 First proportional solenoid valve SV2, SV4 Second proportional solenoid valve

Claims (6)

A first master liquid is slidably accommodated in the cylinder housing and moved back and forth in conjunction with the brake operation member, and slidably accommodated in the cylinder housing and the first piston. A pressure chamber is formed, and a second piston that forms a second master hydraulic pressure chamber with the cylinder housing, and an output hydraulic pressure of the first master hydraulic pressure chamber communicated with the first master hydraulic pressure chamber A stroke simulator that absorbs the amount of fluid corresponding to the first piston and applies a stroke corresponding to the operating force of the brake operating member to the first piston, and a switching means that selectively switches between operation and non-operation of the stroke simulator. In the vehicular brake hydraulic pressure generator, the maximum stroke of the first piston with respect to the cylinder housing is set to a front of the cylinder housing. In smaller than the sum of the maximum stroke of the first piston with respect to the maximum stroke of the second piston the second piston, and the stroke restriction which restricts to a value greater than the maximum stroke of said first piston to said second piston A vehicle brake fluid pressure generating device comprising means. A first master liquid is slidably accommodated in the cylinder housing and moved back and forth in conjunction with the brake operation member, and slidably accommodated in the cylinder housing and the first piston. A pressure chamber is formed, and a second piston is formed between the cylinder housing and a second master hydraulic pressure chamber, and is communicated with the second master hydraulic pressure chamber, and an output hydraulic pressure of the second master hydraulic pressure chamber A stroke simulator that absorbs the amount of liquid according to the pressure and applies a stroke according to the operating force of the brake operating member to the second piston, and a switching means that selectively switches between operation and non-operation of the stroke simulator. In the vehicular brake hydraulic pressure generator, the maximum stroke of the first piston with respect to the cylinder housing is set to a front of the cylinder housing. In smaller than the sum of the maximum stroke of the first piston with respect to the maximum stroke of the second piston the second piston stroke regulating means and regulated to a value greater than the maximum stroke of the second piston relative to the cylinder housing A brake fluid pressure generator for vehicles, comprising: The stroke restricting means, the maximum stroke of the second piston relative to the cylinder housing, the vehicular brake fluid pressure according to claim 1, wherein a greater than half of the maximum stroke of the first piston relative to the cylinder housing Generator. 3. The vehicle brake fluid according to claim 2 , wherein the stroke restricting means has a maximum stroke of the second piston with respect to the first piston larger than half of a maximum stroke of the first piston with respect to the cylinder housing. Pressure generator. The stroke restricting means comprises a restricting stroke setting means for adjusting the maximum stroke of the first piston relative to the cylinder housing, the regulating stroke setting means, and further comprising a piston stopper that is fixed to the first piston The brake fluid pressure generating device for vehicles according to any one of claims 1 to 4 . The restriction stroke setting means includes a piston stopper fixed to the first piston , and a stopper that extends from the end of the cylinder housing on the brake operation member side to the brake operation member side and contacts the piston stopper. The brake fluid pressure generator for vehicles according to claim 5 characterized by things.

Images