JP2007145043A - Brake fluid pressure control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake fluid pressure control device capable of certainly preventing leaked brake fluid from flowing into a motor, without being influenced by vibrations or tilting of a vehicle. <P>SOLUTION: The brake fluid control device mainly comprises an eccentric cam 15 attached to an output shaft 12a of an electric motor 12, a cam storage chamber 14 storing the cam, a pair of a body 15 and a plunger 18 reciprocating with rotation drive of the cam, a pump element 11 storing the body and composed of a plunger storage chamber 16 communicating with the cam storage chamber 14, and the electric motor 12 attached to a pump housing 13 of the pump element. A gasket 32 having a collecting groove 33 formed so as to project to the motor side is provided between the pump housing and the electric motor, and thereby the brake fluid which is going to flow into the motor side is collected by the collecting groove, and prevented from flowing into the motor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brake fluid pressure control device that is used in an anti-lock brake device, a vehicle behavior control device, a traction control device, and the like to control a brake fluid pressure.

  As a conventional brake fluid pressure control device, for example, one described in Patent Document 1 below has been proposed.

  As shown in FIG. 5, the brake fluid pressure control device is attached to the motor 2 attached to the outer surface of the housing 1 and the cam housing chamber 3 in the housing 1 and attached to the output shaft 2 a of the motor 2. And a plunger 5 that is accommodated in a plunger housing chamber (not shown) that communicates with the cam housing chamber 3 and that reciprocates as the eccentric cam 4 is driven to perform a pumping action. ing.

  In addition, the brake fluid pressure control device causes the brake fluid to leak from the gap between the plunger housing chamber and the plunger 5 due to wear of a seal member (not shown) provided in the plunger 5 and flow into the cam housing chamber 3. May end up. Therefore, in order to prevent the leaked brake fluid from flowing into the motor 2, a discharge hole 6 that communicates the cam housing chamber 3 with the outer lower end side is provided, and the leaked brake fluid is supplied from the discharge hole 6 to the housing. 1 is discharged to the outside.

Further, a cylindrical member 7 made of a porous sintered alloy is press-fitted into the lower end of the discharge hole 6, and the brake fluid leaked into the cam housing chamber 3 is discharged while moisture from the outside is discharged. And intrusion of foreign matter can be prevented.
Japanese Patent Laid-Open No. 10-273039

  However, in the conventional brake fluid pressure control device, it is possible to discharge the brake fluid stored in the cam housing chamber 3 through the discharge hole 6, but depending on the behavior of the running vehicle, slope parking, etc. When the vehicle is tilted, the discharge hole 6 may not function.

  That is, depending on the inclination of the vehicle, brake fluid leaking from the gap between the plunger housing chamber and the plunger 5 may flow into the motor 2 and affect the electromagnetic force of the electromagnetic coil of the motor 2. is there.

  The present invention has been devised by paying attention to such a technical problem, and the brake fluid leaking from the gap between the plunger and the plunger housing chamber is not affected by the vibration or inclination of the vehicle. A brake fluid pressure control device that can surely prevent inflow into the vehicle is provided.

  According to the first aspect of the present invention, there is provided a motor attached to an outer surface of the housing via a motor casing, a cam housing chamber formed in the housing, an output shaft of the motor, and the cam housing. An eccentric cam accommodated in the chamber; a plunger accommodating chamber disposed opposite to the cam accommodating chamber from a direction perpendicular to the axis; and communicated with the cam accommodating chamber; and the eccentric cam accommodated in the plunger accommodating chamber; A brake fluid pressure control device provided with a plunger that reciprocates by a rotational drive to perform a pump action, and is sandwiched between the housing and the motor casing, and is inserted into the motor from the cam housing chamber. And a gasket having a collecting groove for collecting the brake fluid to be introduced.

  According to this invention, by providing the gasket having the collecting groove, it becomes possible to discharge the brake fluid leaking into the cam housing chamber from the boundary between the motor and the housing, and a new housing is provided. It is possible to reliably prevent the brake fluid from flowing into the motor without drilling holes.

  According to a second aspect of the present invention, there is provided a vehicle body mounting hole formed in a lower portion of the housing, into which an end of a mounting shaft for mounting the brake hydraulic pressure control device to the vehicle body is inserted and fixed, and the vehicle body mounting hole extending A fluid reservoir chamber for storing brake fluid leaking into the cam housing chamber from between the plunger and the plunger housing chamber, the lower end portion thereof being closed by the mounting shaft and communicating with the cam housing chamber. The side is in communication with the liquid reservoir, and the other end is provided with a communication hole in communication with the lower end of the collection groove.

  According to the present invention, the brake fluid can be discharged from the cam storage chamber also by the liquid storage chamber, and the brake fluid is discharged from the front and rear in the axial direction of the cam storage chamber together with the collection groove. Therefore, it is possible to more reliably prevent the brake fluid from flowing into the motor.

  Further, by providing the communication hole, the brake fluid collected by the collection groove can be guided and stored in the liquid storage chamber, and the brake fluid is also stored in the communication hole. Therefore, a sufficient amount of brake fluid can be secured, and overflow of the brake fluid stored in the collecting groove can be prevented.

  Then, the bottomed liquid reservoir chamber can be formed only by communicating the vehicle body mounting hole and the cam housing chamber, and the brake fluid can be stored without adding new holes or adding parts. Is possible. As a result, the manufacturing cost can be reduced, and problems associated with the external discharge of the brake fluid do not occur.

  The invention described in claim 3 is characterized in that a communication groove is provided on the outer surface of the housing opposite to the collection groove to communicate the open end of the cam housing chamber with the communication hole.

  According to the present invention, since the communication groove is provided, the flow passage opening area for discharging the brake fluid provided at the boundary between the cam housing chamber and the motor is enlarged. Thus, the brake fluid can be easily discharged from the vehicle, and the inflow of the brake fluid into the motor can be more reliably prevented.

  Embodiments of a brake fluid pressure control device for a vehicle according to the present invention will be described below in detail with reference to the drawings.

  This brake fluid pressure control device applies the brake fluid pressure from the master body to the wheel body of each wheel brake according to the depression pressure of the brake pedal during normal braking, and during anti-lock control and vehicle behavior stabilization control, In accordance with an output signal from the electronic control unit, the brake pressure is reduced, maintained or increased again by controlling the pressure reducing valve and the plunger pump.

  As shown in FIG. 1, the plunger pump is composed of a pump element 11 and an electric motor 12 that drives the pump element 11.

  As shown in FIGS. 1, 3 and 4, the pump element 11 includes a pump housing 13 having a substantially L-shaped longitudinal section having a protrusion 13a on the upper end side, and a protrusion 13a of the pump housing 13. A cam housing chamber 14 having a step shape provided at a substantially central position on the outer side surface of the side and a front end side of the drive shaft 12a of the electric motor 12 are accommodated in the cam housing chamber 14 together with the drive shaft 12a. The eccentric cam 15 is provided.

  Further, as shown in FIG. 2, the pump element 11 is provided on both side surfaces orthogonal to the outer surface protrusion 13 a side of the pump housing 13, respectively, so as to be substantially in the center position of the cam housing chamber 14. Plunger housing chambers 16, 16 formed so as to penetrate toward each other, a pair of bodies 17, 17 that are provided in each plunger housing chamber 16, 16 and perform a pump action, and are slidable in the bodies 17, 17. And the holders 19 and 19 for holding the bodies 17 and 17 in the plunger housing chambers 16 and 16, respectively.

  As shown in FIG. 1, the eccentric cam 15 is attached to an eccentric pin 20 provided on the distal end side of the output shaft 12a of the motor 12, and is offset by α with respect to the axis C1 of the output shaft 12a. The cam housing chamber 14 is housed and arranged so as to be orthogonal to the axis C2 of the plungers 18 and 18.

  A tolerance ring 21 is provided at the distal end of the output shaft 12a, which is the distal end side of the eccentric cam 15, to suppress vibration associated with the rotation of the eccentric cam 15.

  As shown in FIG. 2, the body 17 is formed in a substantially bottomed cylindrical shape, and the body 17 and the holder 19 are sequentially inserted into the plunger housing chamber 16 from the outer surface side of the pump housing 13, The plunger housing chamber 16 is held and fixed in the plunger housing chamber 16 via the holder 19 by caulking the outer surface of the opening end of the plunger housing chamber 16.

  The body 17 has a reservoir chamber 22 closed by the plunger 18 in the body 17, and the reservoir chamber 22 is braked only from the passage 18 a of the plunger 18, which will be described later, to the reservoir chamber 22 side. A check valve 23 for receiving the inflow of liquid is provided, and a passage hole 17 a is formed in the bottom of the body 17.

  Further, the body 17 has a pressure chamber 24 formed between the body 17 and the holder 19, and the pressure chamber 24 also extends from the reservoir chamber 22 to the pressure chamber 24 side via the passage hole 17 a. A check valve 25 for receiving the inflow of brake fluid is provided.

  The plunger 18 is urged in a direction protruding from the body 17 via a retainer by a urging member 26 accommodated in the plunger accommodating chamber 16, and the tip thereof is directed to the outer ring outer peripheral surface 15 a of the eccentric cam 15. It is press-contacted and slides in the axial direction following the rotation of the eccentric cam 15.

  The plunger 18 is formed therein with a passage 18a that is opened and closed by the check valve 23, and a through hole 18b communicating with the passage 18a is formed in the outer peripheral surface of the plunger 18.

  Inside the pump housing 13, there are provided a suction port 27 a that communicates with the through hole 18 b and a discharge port 27 b that communicates with the pressure chamber 24, as shown by a two-dot chain line in FIG. 2.

  Therefore, the brake fluid sent into the reservoir chamber 22 by pushing the check valve 23 through the through hole 18b and the passage 18a from the suction port 27a is rotated by the driving force of the electric motor 12. Accordingly, the plungers 18 and 18 reciprocate to push open the check valve 25 and flow into the pressure chamber 24 to be discharged from the discharge port 27b.

  Since the plunger 18 is slidably held by the opening tip 16a in the plunger receiving chamber 16, there is a slight gap between the inner periphery of the opening tip 16a and the outer periphery of the plunger 18. Since the clearance C is provided, the O-ring 28 is provided on the outer peripheral side to prevent leakage of the brake fluid from the clearance C into the cam housing chamber 14.

  As shown in FIGS. 1 and 2, the pump housing 13 is provided with a vehicle body mounting hole 29 at the bottom, and the brake fluid pressure control device is installed at the lower end of the vehicle body mounting hole 29. A mounting shaft 30 is press-fitted for mounting.

  As shown in FIG. 1, the vehicle body mounting hole 29 provided in the pump housing 13 communicates with the bottom side of the lower end portion in the cam housing chamber 14 in the vertical direction from the bottom side of the pump housing 13. Thus, the cam housing chamber 14 is formed so as to penetrate therethrough. As a result, the brake fluid leaking into the cam housing chamber 14 can be received not only into the cam housing chamber 14 but also into the vehicle body mounting hole 29.

  That is, the vehicle body mounting hole 29 is closed at the lower end portion by the mounting shaft 30 to form a bottomed space, thereby forming a liquid reservoir chamber 31 for storing the leaked brake fluid in the cam housing chamber 14. Has been.

  Accordingly, the brake fluid leaked into the cam housing chamber 14 is received by the liquid reservoir chamber 31, so that the leaked brake fluid is not discharged to the outside, and the cam housing chamber 14 is filled with the brake fluid. In addition, it is possible to reliably store in the pump housing 13.

  As shown in FIG. 1, the electric motor 12 is attached to the pump housing 11 via a cup-shaped motor casing 12b, and includes the output shaft 12a, a magnet (not shown), an armature, and the like. The pump element 11 is driven in response to an output signal from the electronic control unit.

  Further, as shown in FIGS. 3 and 4, the motor casing 12b has three bolt insertion holes (not shown) formed at substantially equal intervals in a flange portion provided at the opening edge. It is fixed to the pump housing 13 by a bolt (not shown) through the insertion hole.

  As shown in FIGS. 1, 3 and 4, the electric motor 12 includes a motor casing 12 b which is used to prevent foreign matter from entering the pump housing 13 or the motor casing 12 b from the outside. The pump housing 13 is attached to the outer side surface of the pump housing 13 via the gasket 32.

  The gasket 32 is formed by press-molding a substantially circular metal plate. As shown in FIGS. 1 and 4, an insertion hole 32a for inserting the bearing portion of the electric motor 12 is formed at the center position. In addition, a collecting groove 33 is formed in a convex shape on the electric motor 12 side in the lower half of the hole edge of the insertion hole 32a.

  Further, as shown in FIG. 3, the gasket 32 has three mounting holes 32b having substantially the same diameter as the bolt insertion holes at positions matching the bolt insertion holes of the motor casing 12b. The vicinity of the mounting hole 32b is slightly enlarged in diameter, and is fastened and fixed to the outer surface of the pump housing 13 on the protruding portion 13a side by a bolt for mounting and fixing the motor casing 12b.

  As shown in FIGS. 3 and 4, the collection groove 33 is formed in a substantially triangular shape in cross section in which the groove width gradually decreases downward from the lower half of the hole edge of the insertion hole 32 a, and The outer peripheral edge of the collection groove 33 is slightly inclined.

  As a result, the brake fluid leaking into the cam housing chamber 14 via the gap C is guided and stored in the collecting groove 33 at the boundary between the pump housing 13 and the motor casing 12b. Yes.

  As shown in FIGS. 1 and 4, a communication hole 34 is formed in the outer surface of the pump housing 13 at a position facing the lower end of the collection groove 33.

  The communication hole 34 is provided substantially horizontally along the thickness direction of the pump housing 13 and is formed to have substantially the same diameter as the arc portion on the lower end side of the collection groove 33, and one end side is the collection groove. 33 communicates with the liquid reservoir chamber 31 at the other end.

  Thus, the brake fluid collected by the collection groove 33 can be stored in the communication hole 34 or the liquid reservoir chamber 31.

  Further, on the outer surface of the pump housing 13 facing the collection groove 33, one end side communicates with the opening edge of the cam housing chamber 14 and the other end side, as shown in FIGS. 1, 3, and 4. A communication groove 35 communicating with the communication hole 34 is notched.

  As shown in FIGS. 3 and 4, the communication groove 35 is formed in a vertical cross-sectional concave shape having substantially the same groove width as the diameter of the communication hole 34, and is suspended from the opening edge of the cam housing chamber 14. In addition, a cutout is formed along the vertical direction of the pump housing 13 to substantially the same position as the lower end of the collection groove 33.

  Hereinafter, the operation of the brake fluid pressure control apparatus according to this embodiment will be described with reference to FIGS.

  As shown in FIG. 2, the brake fluid pressure control device is configured such that the gap C between the opening tip 16a of the plunger housing chamber 16 and the plunger 18 is sealed by the O-ring 28. The brake fluid leaks into the cam housing chamber 14 through the gap C and is stored in the cam housing chamber 14 when the wear deterioration occurs with time due to sliding.

  Eventually, when the amount of brake fluid stored in the cam housing chamber 14 increases, the brake fluid in the cam housing chamber 14 normally enters the liquid reservoir chamber 31 as shown by the thin dotted line in FIG. Inflow and storage are prevented, and overflow in the cam housing chamber 14 is prevented. When the brake fluid in the liquid reservoir 31 overflows, it flows into the communication hole 34 and is stored.

  When the brake fluid pressure control device is tilted toward the electric motor 12 due to, for example, vibration or running on a hill and parking, the brake fluid in the cam housing chamber 14 is indicated by a thick dotted line in FIG. At the same time, it tends to flow into the electric motor 12 through the opening end of the cam housing chamber 14, but it flows down into the collection groove 33 and the communication groove 35 at the boundary between the pump housing 13 and the motor casing 12 b. The inflow of the brake fluid into the electric motor 12 is prevented.

  Further, the brake fluid collected through the collection groove 33 and the communication groove 35 flows into the communication hole 34, and overflow from the collection groove 33 and the communication groove 35 is prevented.

  According to this embodiment, the O-ring 28 deteriorates and brake fluid leaks into the cam housing chamber 14 through the gap C, and the brake fluid pressure control device causes the electric motor 12 to change depending on the behavior of the vehicle body. Even if tilted to the side, the brake fluid stored in the cam housing chamber 14 is reliably prevented from flowing into the electric motor 12.

  Further, when the collecting groove 33 is provided, the gasket 32 is manufactured by press molding, so that the manufacturing cost is low and it is necessary to newly drill the pump housing 13 having a large number of passage holes. Therefore, the manufacturing cost can be reduced without increasing the size of the pump housing 13.

  By providing the communication hole 34, the brake fluid collected by the collection groove 33 can be stored in the liquid reservoir chamber 31, and the brake fluid in the pump housing 13 can be stored. Since the storage allowance also increases, the brake fluid leaked into the cam housing chamber 14 is not discharged to the outside, and the leaked brake fluid is reliably discharged without overflowing into the cam housing chamber 14 and the electric motor 12. It can be recovered.

  Further, since the communication groove 35 is provided on the opposing surface of the collection groove 33 and the opening cross-sectional area of the groove where the brake fluid is collected together with the collection groove 33 is expanded, the electric motor 12 The inflow of brake fluid into the interior is more reliably prevented.

  Further, since the opening of the collecting groove 33 extends over the entire lower half of the opening edge of the cam housing chamber 14, the brake fluid flowing out from the cam housing chamber 14 toward the electric motor 12 is more reliably collected. Thus, the brake fluid can be reliably prevented from flowing into the electric motor 12.

  And since the said communication groove 35 is provided in the outer surface of the said pump housing 13, since it is not necessary to give a new hole processing in the pump housing 13, without enlarging this pump housing 13, This can contribute to preventing the brake fluid from flowing into the electric motor 12.

  The present invention is not limited to the configuration of each of the embodiments described above, and for example, the shape and size of the pump element 11 and the electric motor 12 can be freely changed according to the specification and size of the automobile.

  Further, the communication hole 34 can be provided to be inclined toward the liquid reservoir 30, and further, the communication groove 35 can be formed in a vertical U-shape. The mounting shaft 30 may be screwed into the vehicle body mounting hole 29.

1 is a partial cross-sectional view of a brake fluid pressure control device illustrating an embodiment according to the present invention and explaining a main part of the present invention. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is an arrow view of the arrow C of FIG. It is a fragmentary sectional view of a brake fluid pressure control device explaining a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Motor 12a ... Output shaft 12b ... Motor casing 13 ... Pump housing (housing)
DESCRIPTION OF SYMBOLS 14 ... Cam accommodation chamber 15 ... Eccentric cam 16 ... Plunger accommodation chamber 17 ... Body 18 ... Plunger 29 ... Car body mounting hole 30 ... Mounting shaft 31 ... Liquid reservoir chamber 32 ... Gasket 33 ... Collection groove 34 ... Communication hole 35 ... Communication groove

Claims (3)

A motor attached to the outer surface of the housing via a motor casing;
A cam housing chamber formed inside the housing;
An eccentric cam attached to the output shaft of the motor and housed in the cam housing chamber;
A plunger housing chamber disposed opposite to the cam housing chamber from a direction perpendicular to the axis and communicating with the cam housing chamber;
A plunger housed in the plunger housing chamber and reciprocatingly driven by the rotational drive of the eccentric cam to perform a pump action;
A brake fluid pressure control device provided with
A gasket that is sandwiched between the housing and the motor casing and has a collection groove for collecting brake fluid that is about to flow into the motor from the cam housing chamber;
A brake fluid pressure control device comprising: A vehicle body mounting hole formed in a lower portion of the housing and into which an end of a mounting shaft for mounting the brake hydraulic pressure control device to the vehicle body is inserted and fixed;
The vehicle body mounting hole extends to communicate with the cam housing chamber, and the lower end portion is closed by the mounting shaft, and brake fluid leaking into the cam housing chamber from between the plunger and the plunger housing chamber is stored. A liquid reservoir chamber,
One end side communicates with the liquid reservoir, and the other end communicates with the lower end of the collection groove,
The brake hydraulic pressure control device according to claim 1, further comprising: The brake fluid according to claim 1, wherein a communication groove that communicates the opening end of the cam housing chamber and the communication hole is provided on an outer surface of the housing that faces the collection groove. Pressure control device.

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