CA2000386A1 - Integral metering valve with reservoir-balanced pressure for bleed procedure - Google Patents
Integral metering valve with reservoir-balanced pressure for bleed procedureInfo
- Publication number
- CA2000386A1 CA2000386A1 CA 2000386 CA2000386A CA2000386A1 CA 2000386 A1 CA2000386 A1 CA 2000386A1 CA 2000386 CA2000386 CA 2000386 CA 2000386 A CA2000386 A CA 2000386A CA 2000386 A1 CA2000386 A1 CA 2000386A1
- Authority
- CA
- Canada
- Prior art keywords
- bore
- metering valve
- master cylinder
- reservoir
- pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 16
- 239000012530 fluid Substances 0.000 claims abstract description 29
- 241001052209 Cylinder Species 0.000 claims 1
- 239000012298 atmosphere Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000006854 communication Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000000994 depressogenic effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
- B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
- B60T11/16—Master control, e.g. master cylinders
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/26—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels
- B60T8/262—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels using valves with stepped characteristics
- B60T8/265—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels using valves with stepped characteristics for hydraulic brake systems
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Transmission Of Braking Force In Braking Systems (AREA)
Abstract
INTEGRAL METERING VALVE WITH RESERVOIR-BALANCED PRESSURE
FOR BLEED PROCEDURE
ABSTRACT
A master cylinder (10) includes a housing (14) having a metering valve (40) integral therewith. The master cylinder housing (14) has a boss (18) which de-fines a transverse bore (20) that communicates at one end (24) with a chamber (12) of the master cylinder (10) and at a second end (28) with a reservoir (16) positioned on the master cylinder housing (14). The bore (20) has a outlet opening (30) which communicates with front brakes of the vehicle. The metering valve (40) is disposed within the bore (20) and during a bleed-and-fill proce-dure is subjected to approximately equal pressures within the reservoir (16) and at the one end (24) of the bore (20) so that the metering valve (40) remains open for fluid flow thereat.
FOR BLEED PROCEDURE
ABSTRACT
A master cylinder (10) includes a housing (14) having a metering valve (40) integral therewith. The master cylinder housing (14) has a boss (18) which de-fines a transverse bore (20) that communicates at one end (24) with a chamber (12) of the master cylinder (10) and at a second end (28) with a reservoir (16) positioned on the master cylinder housing (14). The bore (20) has a outlet opening (30) which communicates with front brakes of the vehicle. The metering valve (40) is disposed within the bore (20) and during a bleed-and-fill proce-dure is subjected to approximately equal pressures within the reservoir (16) and at the one end (24) of the bore (20) so that the metering valve (40) remains open for fluid flow thereat.
Description
Zt)(H?~fi , INTEGRAL METERING VALVE WITH RESERVOIR-BAL~ANCED PRESSURE
FOR ~I,EED PROCEDURE
Th~ present invention relates generally to a metering valve disposed within a master cylinder housing, and in particular to a metering valve that is vented to the reservoir of the master cylinder.
Metering valves have been provided in order to effect a hold off of pressure to the front disc brakes of a vehicle in order to avoid a skidding condition. Because the front disc brakes of a vehicle may be actuated to effect braking at a much lower pressure than the pressure required to actuate rear drum brakes, it has been neces-sary in certain braking systems to hold off the communi-cation of certain levels of brake pressure to the front disc brakes until a higher braking pressure is attained by the master cylinder so that the front and rear brakes are actuated at approximately the same time. Metering valves accomplish this by permitting, first of all, a very low fluid pressure to be communicated therethrough, and then closing to hold off the brake fluid pressure until a higher pressure is reached, at which time both the disc brakes and rear drum brakes are actuated by the higher fluid pressure. Prior metering valves have been contained typically within a housing that is remote from the master cylinder. One reason for the remote housing is that the metering valve is typically vented to atmos-phere, with the portion of the metering valve vented toatmosphere providing in effect a "button" that needs to be depressed whenever the master cylinder and braking system experiences a pressure bleed procedure. As the pressure bleed procedure proceeds, the valve is held open so that the brake fluid can flow therethrough. Without the metering valve being held open, the valve would see the pressurized brake fluid received via the master cy-linder chamber as a higher pressure and would close, thereby preventing the flow of brake fluid therethrough to the associated brake lines. Metering valves have been contained within a master cylinder housing, but have continued to be vented conventionally to atmosphere.
. ~.. . ..
. ~ ... .
.~: .. ... .
FOR ~I,EED PROCEDURE
Th~ present invention relates generally to a metering valve disposed within a master cylinder housing, and in particular to a metering valve that is vented to the reservoir of the master cylinder.
Metering valves have been provided in order to effect a hold off of pressure to the front disc brakes of a vehicle in order to avoid a skidding condition. Because the front disc brakes of a vehicle may be actuated to effect braking at a much lower pressure than the pressure required to actuate rear drum brakes, it has been neces-sary in certain braking systems to hold off the communi-cation of certain levels of brake pressure to the front disc brakes until a higher braking pressure is attained by the master cylinder so that the front and rear brakes are actuated at approximately the same time. Metering valves accomplish this by permitting, first of all, a very low fluid pressure to be communicated therethrough, and then closing to hold off the brake fluid pressure until a higher pressure is reached, at which time both the disc brakes and rear drum brakes are actuated by the higher fluid pressure. Prior metering valves have been contained typically within a housing that is remote from the master cylinder. One reason for the remote housing is that the metering valve is typically vented to atmos-phere, with the portion of the metering valve vented toatmosphere providing in effect a "button" that needs to be depressed whenever the master cylinder and braking system experiences a pressure bleed procedure. As the pressure bleed procedure proceeds, the valve is held open so that the brake fluid can flow therethrough. Without the metering valve being held open, the valve would see the pressurized brake fluid received via the master cy-linder chamber as a higher pressure and would close, thereby preventing the flow of brake fluid therethrough to the associated brake lines. Metering valves have been contained within a master cylinder housing, but have continued to be vented conventionally to atmosphere.
. ~.. . ..
. ~ ... .
.~: .. ... .
2(~(?:3fil~;
.`- -- 2 --It is highly desirable to provide a metering valve that is housed integral with the master cylinder so that a remote housing is not necessary. It would be advantageous if the metering valve is provided in the master cylinder housing so that there is eliminated any external leakage paths. It is also highly desirable to provide a metering valve that does not have to be held open during a pressure bleed procedure.
The present invention provides solutions to the above problems by providing a master cylinder with an integral metering valve, comprising a master cylinder housing having a pressure chamber therein, a bore having one part communicating with said chamber, a second part communicating with a fluid reservoir, and the bore also communicating with an outlet, metering valve means dis-posed within said bore so that during a bleed-and-fill procedure fluid in the reservoir and at the one part of the bore exerts a balanced pressure on said metering valve means such that the valve means remains open for 20 fluid flow thereat. - -One way of carrying out the invention is des-cribed in detail with reference to the drawings which illustrate a specific embodiment in which~
Figure 1 is a cross-section of a master cylinder 25 housing with an integral metering valve. -Figure 1 represents a section view of a recessed cartridge master cylinder such as that disclosed in Steer United States Patent No. 4,475,005. The master cylinder is designated generally by reference numeral 10 in Figure 1. Master cylinder 10 contains two pressure chambers, one of which is shown in Figure 1 and identified by re-ference numeral 12. Master cylinder 10 includes a hous-ing 14 to which is attached a reservoir 16. Contained within reservoir 16 is brake fluid (not shown). Master cylinder housing 14 includes a boss 18 which extends transversely to the chambers of the master cylinder. The ~-~
boss 18 includes a transverse bore 20 which extends from an opening 22 at one end 24 to an opening 26 at the zn~ fi second end 28 of bore 20. An outlet 30 communicates bore 20 with the front brakes of the vehicle. Located within bore 20 i8 a metering valve designated generally by re-ference numeral 40. Metering valve 40 comprises a prior and well known production metering valve. It should be clearly understood that the present invention may include any type of valving mechanism which preforms a metering function and therefore may be designated a "metering valve". Netering valve 40 includes a valve member 42 which includes end piece 44 disposed adjacent seal 46 which seals on seat 15. Valve member 42 is captured within an end member 48 located fixedly within bore 20 by means of ring 50. End member 48 is abutted by flexible seal 52 which provides a seat for a retainer 54. A re-tainer 56 is located over flexible seal 46 and about valvemember 42 to provide a seat for exterior spring 60. The retainers 54 and 56 also provide seats for an interior spring 58. Retainer 56 includes a side opening 57.
Metering valve 40 operates in conventional manner wherein at a very low brake pressure level, fluid pressure is free to flow through opening 22, about end member 44, through the central opening of seal 46, through side open-ing 57 and out through outlet 30 to the front brakes. Upon the communication of a slightly higher pressure to bore 20 by means of an initial actuation of the master cylinder 10, the slightly higher pressure causes flexible seal 52 to deform upwardly so that end member 44 is brought into contact with flexible seal 46 thereby closing bore 20 to fluid flow therethrough to the outlet 30. However, as then a further higher pressure is communicated to bore 20 by means of the actuation of the master cylinder, the higher pressure causes the exterior spring 60 to be com-pressed so that the flexible seal 46 and retainer 56 are lifted off of valve seat 15 and fluid may flow around end member 44, flexible seal 46, past seat 15, into bore 20 and outwardly to the brakes through outlet 30.
v " . - . , . ~. .- :
2n(u~
It is during a bleed-and-fill procedure effected in order to fill the braking system with brake fluid that the master cylinder and integral metering valve of the present invention provide substantial advantages over prior designs. Because the fluid contained within reser-voir 16 is essentially at the same pressure as fluid present at opening 22 during the bleed-and-fill proce-dure, metering valve 40 remains in the unactuated posi-tion illustrated in Figure 1. This permits brake fluid to flow freely in and through the metering valve and to the associated brake lines. This is accomplished because the metering valve is vented to the reservoir, rather than being vented to atmosphere as has been typical in prior designs. Thus, during a pressure bleed-and-fill procedure, it is not necessary to utilize a fixture to hold the metering valve in an open position during the bleed-and-fill procedure. Additionally, the provision of a metering valve vented to a reservoir permits the meter-ing valve to be accommodated and contained readily within the housing of the master cylinder. This provides a further advantage in that there are eliminated any exter-nal brake fluid leakage paths. If the flexible seal 52 should leak during any high pressure fluid application, the fluid leaks into the reservoir. This is contrary to conventional designs wherein the fluid leakage would result in fluid leaking out of the brake system and being lost.
Various modifications of the above-described embodiment o the invention will be apparent to those skilled in the art. It is to be understood that such modifications can be made without departing from the scope of the invention.
.`- -- 2 --It is highly desirable to provide a metering valve that is housed integral with the master cylinder so that a remote housing is not necessary. It would be advantageous if the metering valve is provided in the master cylinder housing so that there is eliminated any external leakage paths. It is also highly desirable to provide a metering valve that does not have to be held open during a pressure bleed procedure.
The present invention provides solutions to the above problems by providing a master cylinder with an integral metering valve, comprising a master cylinder housing having a pressure chamber therein, a bore having one part communicating with said chamber, a second part communicating with a fluid reservoir, and the bore also communicating with an outlet, metering valve means dis-posed within said bore so that during a bleed-and-fill procedure fluid in the reservoir and at the one part of the bore exerts a balanced pressure on said metering valve means such that the valve means remains open for 20 fluid flow thereat. - -One way of carrying out the invention is des-cribed in detail with reference to the drawings which illustrate a specific embodiment in which~
Figure 1 is a cross-section of a master cylinder 25 housing with an integral metering valve. -Figure 1 represents a section view of a recessed cartridge master cylinder such as that disclosed in Steer United States Patent No. 4,475,005. The master cylinder is designated generally by reference numeral 10 in Figure 1. Master cylinder 10 contains two pressure chambers, one of which is shown in Figure 1 and identified by re-ference numeral 12. Master cylinder 10 includes a hous-ing 14 to which is attached a reservoir 16. Contained within reservoir 16 is brake fluid (not shown). Master cylinder housing 14 includes a boss 18 which extends transversely to the chambers of the master cylinder. The ~-~
boss 18 includes a transverse bore 20 which extends from an opening 22 at one end 24 to an opening 26 at the zn~ fi second end 28 of bore 20. An outlet 30 communicates bore 20 with the front brakes of the vehicle. Located within bore 20 i8 a metering valve designated generally by re-ference numeral 40. Metering valve 40 comprises a prior and well known production metering valve. It should be clearly understood that the present invention may include any type of valving mechanism which preforms a metering function and therefore may be designated a "metering valve". Netering valve 40 includes a valve member 42 which includes end piece 44 disposed adjacent seal 46 which seals on seat 15. Valve member 42 is captured within an end member 48 located fixedly within bore 20 by means of ring 50. End member 48 is abutted by flexible seal 52 which provides a seat for a retainer 54. A re-tainer 56 is located over flexible seal 46 and about valvemember 42 to provide a seat for exterior spring 60. The retainers 54 and 56 also provide seats for an interior spring 58. Retainer 56 includes a side opening 57.
Metering valve 40 operates in conventional manner wherein at a very low brake pressure level, fluid pressure is free to flow through opening 22, about end member 44, through the central opening of seal 46, through side open-ing 57 and out through outlet 30 to the front brakes. Upon the communication of a slightly higher pressure to bore 20 by means of an initial actuation of the master cylinder 10, the slightly higher pressure causes flexible seal 52 to deform upwardly so that end member 44 is brought into contact with flexible seal 46 thereby closing bore 20 to fluid flow therethrough to the outlet 30. However, as then a further higher pressure is communicated to bore 20 by means of the actuation of the master cylinder, the higher pressure causes the exterior spring 60 to be com-pressed so that the flexible seal 46 and retainer 56 are lifted off of valve seat 15 and fluid may flow around end member 44, flexible seal 46, past seat 15, into bore 20 and outwardly to the brakes through outlet 30.
v " . - . , . ~. .- :
2n(u~
It is during a bleed-and-fill procedure effected in order to fill the braking system with brake fluid that the master cylinder and integral metering valve of the present invention provide substantial advantages over prior designs. Because the fluid contained within reser-voir 16 is essentially at the same pressure as fluid present at opening 22 during the bleed-and-fill proce-dure, metering valve 40 remains in the unactuated posi-tion illustrated in Figure 1. This permits brake fluid to flow freely in and through the metering valve and to the associated brake lines. This is accomplished because the metering valve is vented to the reservoir, rather than being vented to atmosphere as has been typical in prior designs. Thus, during a pressure bleed-and-fill procedure, it is not necessary to utilize a fixture to hold the metering valve in an open position during the bleed-and-fill procedure. Additionally, the provision of a metering valve vented to a reservoir permits the meter-ing valve to be accommodated and contained readily within the housing of the master cylinder. This provides a further advantage in that there are eliminated any exter-nal brake fluid leakage paths. If the flexible seal 52 should leak during any high pressure fluid application, the fluid leaks into the reservoir. This is contrary to conventional designs wherein the fluid leakage would result in fluid leaking out of the brake system and being lost.
Various modifications of the above-described embodiment o the invention will be apparent to those skilled in the art. It is to be understood that such modifications can be made without departing from the scope of the invention.
Claims (6)
1. A master cylinder with an integral metering valve, comprising a master cylinder housing having a pressure chamber therein, a bore having one part communi-cating with said chamber, a second part communicating with a fluid reservoir, and the bore also communicating with an outlet, metering valve means disposed within said bore so that during a bleed-and-fill procedure fluid in the reservoir and at the one part of the bore exerts a balanced pressure on said metering valve means such that the valve means remains open for fluid flow thereat.
2. A master cylinder and integral metering valve in accordance with claim 1, wherein said one part comprises one end of the bore and the second part com-prises an opposite end of the bore, the opposite end of the bore communicating directly with said reservoir and the one end of the bore communicating with said chamber via a opening.
3. A master cylinder and integral metering valve in accordance with claim 2, wherein said outlet communi-cates with front brakes of a vehicle.
4. A master cylinder and integral metering valve in accordance with claim 3, wherein said bore is disposed within a boss of said housing, the boss having an open end comprising said opposite end of the bore and the reservoir positioned about the open end.
5. A method for effecting a bleed-and-fill pro-cedure of a master cylinder and metering valve, compris-ing the steps of: (1) providing fluid to a master cylin-der having a bore with a metering valve disposed therein, the bore disposed within a housing of the master cylinder and having one end communicating with a pressure chamber of the master cylinder a second end communicating with a reservoir of the master cylinder, and the bore also com-municating with an outlet, and (2) effecting fluid flow in the chamber and bore at a pressure such that pressure in the reservoir and one end of the bore are substantially equal so that the metering valve is essentially pressure balanced and fluid may flow therethrough.
6. The method in accordance with claim 5, wherein the outlet communicates with a brake of a vehicle.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US27407788A | 1988-11-21 | 1988-11-21 | |
| US274,077 | 1988-11-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2000386A1 true CA2000386A1 (en) | 1990-05-21 |
Family
ID=23046660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2000386 Abandoned CA2000386A1 (en) | 1988-11-21 | 1989-10-10 | Integral metering valve with reservoir-balanced pressure for bleed procedure |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU4642189A (en) |
| CA (1) | CA2000386A1 (en) |
| WO (1) | WO1990005656A1 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3321914A (en) * | 1965-04-19 | 1967-05-30 | Bendix Corp | Braking system for vehicles |
| US3522706A (en) * | 1968-08-15 | 1970-08-04 | Wagner Electric Corp | Tandem master cylinder |
| US4154260A (en) * | 1977-03-10 | 1979-05-15 | The Bendix Corporation | Master cylinder having a proportioning and metering valve encapsulated in separate outlet ports |
| EP0049185A3 (en) * | 1980-09-29 | 1982-09-08 | The Bendix Corporation | Compensator valve for a fluid pressurizing device |
| DE3244563A1 (en) * | 1982-12-02 | 1984-06-07 | Alfred Teves Gmbh, 6000 Frankfurt | PRINT CONTROL UNIT |
-
1989
- 1989-10-10 CA CA 2000386 patent/CA2000386A1/en not_active Abandoned
- 1989-11-17 AU AU46421/89A patent/AU4642189A/en not_active Abandoned
- 1989-11-17 WO PCT/US1989/005093 patent/WO1990005656A1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| AU4642189A (en) | 1990-06-12 |
| WO1990005656A1 (en) | 1990-05-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |