GB2588221A - Pedal feel simulator and an assembly process thereof - Google Patents
Pedal feel simulator and an assembly process thereof Download PDFInfo
- Publication number
- GB2588221A GB2588221A GB1915022.6A GB201915022A GB2588221A GB 2588221 A GB2588221 A GB 2588221A GB 201915022 A GB201915022 A GB 201915022A GB 2588221 A GB2588221 A GB 2588221A
- Authority
- GB
- United Kingdom
- Prior art keywords
- piston
- plug
- pressure piece
- spring
- steel spring
- 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.)
- Withdrawn
Links
- 238000000034 method Methods 0.000 title claims abstract description 18
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 27
- 239000010959 steel Substances 0.000 claims abstract description 27
- 230000000717 retained effect Effects 0.000 claims abstract description 5
- 238000005219 brazing Methods 0.000 claims abstract description 3
- 238000004023 plastic welding Methods 0.000 claims abstract description 3
- 239000002184 metal Substances 0.000 claims description 2
- 239000004033 plastic Substances 0.000 claims description 2
- 239000012530 fluid Substances 0.000 description 6
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000000750 progressive effect Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002991 molded plastic Substances 0.000 description 1
- 230000003387 muscular Effects 0.000 description 1
- 239000002245 particle Substances 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
- 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
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
- B60T8/40—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system
- B60T8/4072—Systems in which a driver input signal is used as a control signal for the additional fluid circuit which is normally used for braking
- B60T8/4081—Systems with stroke simulating devices for driver input
- B60T8/409—Systems with stroke simulating devices for driver input characterised by details of the stroke simulating device
-
- 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
- B60T2270/00—Further aspects of brake control systems not otherwise provided for
- B60T2270/82—Brake-by-Wire, EHB
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Braking Elements And Transmission Devices (AREA)
- Regulating Braking Force (AREA)
Abstract
A pedal feel simulator (PFS) for automotive braking systems, e.g. a brake-by-wire (BBW) system and an assembly process for the simulator. The stroke simulator comprises a housing 7 with a bore b in which is located a piston 6 (labelled 4 in description) with an end subject to hydraulic pressure, e.g. from a master cylinder of the braking system. The simulator also includes a rubber spring 2, a steel spring 4 (labelled 6 in description), a closing cover 1, a pressure piece 3 and a plug 8. The steel spring 4 is retained between the pressure piece 3 and the piston 6 by the plug 8, which is inserted into the piston. The pressure piece is located between the steel spring 4 and rubber spring 2. The piston and plug may be tightly connected, e.g. by clamping, a press fit connection, laser brazing or ultrasonic plastic welding. The steel spring, pressure piece and piston form a sub-assembly which is connected together before placing in the bore in order for the spring to remain the same length throughout assembly.
Description
Description
Pedal feel simulator and an assembly process thereof The present invention generally relates to a pedal feel simulator for automotive braking systems, and an assembly process thereof.
By means of currently known electrohydraulic braking systems, the driver can be decoupled from the direct access to the wheel brakes, this function being used in a "brake-by-wire" operating mode. Pressure is actively build-up in the brake circuits with the aid of a driver-independent pressure generator, usually driven by an electric motor. This is generally done by coupling the pressure chamber of a master cylinder to a hydraulic consumer called "pedal feel simulator". Also, a hydraulic fallback mode is provided, in which the driver can decelerate or stop the vehicle by muscular force on actuation of the brake pedal; in this case, the pressure chamber of the master cylinder is coupled to one of the hydraulic circuits feeding the brake wheels cylinders.
Prior art is published e.g. under EP1802504B1, U89555786B2, W02015022264A1, W02018172060A1.
The simulator is custom-built for each customer and ensures a specific force versus stroke curve at compression, which accurately reproduces the customer-required force versus stroke curve at pedal. Usually, a simulator comprises a piston, a steel spring, a rubber spring and a pressure piece within a housing. The most significant elements playing a role in the modelling the characteristic curve of stroke versus force are the rubber spring element and the pressure piece, which are custom-built for each single different brake pedal characteristic curve.
As shown in the figure illustrating the characteristic curve of stroke versus force of the brake pedal, the stroke is linear only in a first stage that corresponds to the pedal travel required to bring the brake pads in contact with the brake disk and depends on the steel spring design. The simulator reproduces the linear stroke of the brake pedal at the start of the braking phase.
Afterwards a transition stage follows, whithin which the stroke is influenced by the design of the pressure piece, whereas for the next stages of progressive force increase, the stroke is accomplished exclusively by the rubber spring's design and volumetric compression.
However, during the simulator assembly, because the steel spring is not compressed, the pressure piece and the rubber spring are not yet mounted, there are measurements to be done first. The assembly is done only on a final line of manufacturing, with a risk for the steel spring and the pressure piece to fall off during the manipulation of parts and assembly, thus the cycle time of production is not optimized.
The technical problem to be solved is to reduce the production 20 cycle time and to increase the speed and precision of the assembly.
Therefore, the objective of the invention is to solve the deficiencies of the mentioned prior art and to provide a 25 redesigned pedal feel simulator and an assembly process thereof.
This objective is achieved according to the invention by means of the technical characteristics mentioned in the independent claims, namely a pedal feel simulator and an assembly process 30 thereof.
Further advantageous embodiments are the subject matter of the dependent claims.
A first subject-matter of this invention is a pedal feel simulator comprising a housing provided with an axial bore throughout its entire length, a piston with an end subjected to hydraulic pressure, a rubber spring deformable up to a limited extend, a pressure piece placed between the steel spring and the rubber spring, a steel spring positioned into the bore and placed between the pressure piece and the piston, and a closing cover closing the bore and limiting the travel of the rubber spring inside the bore, wherein the steel spring, the pressure piece and the piston forma sub-assembly, the steel spring being retained between the piston and the pressure piece by means of a plug inserted into the piston.
Theadvantagesof the pedal feel simulatoraccordingto invention 15 are the following: - the obtained one-pack design enables a more precise measurement of the simulator that can be analyzed and manipulated as a package; - the components used are standardized; -the installed dimension of the steel spring is always constant, not affected by the assembly process itself.
A second subject-matter of invention is an assembly process of a pedal feel simulator, comprising the steps of: providing a tight connection between a plug and a piston; providing a sub-assembly formed by a steel spring, a pressure piece and the piston provided with the plug, wherein the steel spring is retained between the pressure piece and the piston by means of the plug, and providing a final assembly by introducing the sub-assembly and a rubber spring in a housing provided with a bore and closing them inside with a closing cover.
The advantages of the assembly process according to invention are the following: - optimized cycle time, an improved logistic chain and elimination of design and purchasing efforts for the introduction and management of customized components; - low tooling cost; - allows a very fine adjustment during the assembly process; - high volumes capabilities can be achieved by allowing part suppliers to pre-assembly the components and adjusting the simulator gap at the final assembly location or at supplier.
Further special features and advantages of the present invention can be taken from the following description of advantageous embodiments by way of the accompanying drawings.
Fig. 1 is a schematic block diagram of a prior art pedal feel simulator integrated in an electronic braking system; Fig. 2 shows a characteristic curve of stroke versus force at 20 brake pedal; Fig. 3 is a schematic section through a prior art pedal feel simulator; Fig. 4 is a schematic section through a first embodiment of a pedal feel simulator according to invention; Fig. 5 is a schematic section through a second embodiment of a pedal feel simulator according to invention.
Referring now to Fig. 1, a schematic diagram of a prior art pedal feel simulator integrated in an electronic braking system is shown, in a simplified manner, e.g. to illustrate the connections of the pedal feel simulator PFS with a brake fluid reservoir R and a tandem master cylinder TMC. The tandem master cylinder comprises a primary piston P1 and a secondary one (not referenced) that travels within a pressure chamber PC, afferent piston springs (it is referenced only the secondary piston spring SS) and sealing rings SR. The connection with the brake fluid reservoir is made through compensations ports cp, and the hydraulic connection with the rest of the braking system is made by opening a cut valve CV. A brake pedal push rod PR transmits the motion applied on the brake pedal to the primary piston P1 of the tandem master cylinder TMC. In the normal braking function of the braking system (the so-called "brake-by-wire" operating mode), the tandem master cylinder TMC is decoupled from the wheel brakes (not shown), instead the pedal feel simulator PE'S is connected through an afferent doenedvalveV, and the brake fluid volume displaced in the tandem master cylinder by the actuation of the brake pedal by the driver is received by the pedal feel simulator, so the driver is given the familiar pedal feel.
Fig. 2 shows a characteristic curve of the pedal feel simulator, representing the dependence of 7he stroke versus pedal force. The main components of the known pedal feel simulator involved in this are a rubber spring RS, a pressure piece PP, and a piston P by means of which the simulator reproduces the stroke of the brake pedal at the start of the braking phase. This stroke is linear only in a first stage that corresponds to the pedal travel required to bring the brake pads in contact with the brake disk. A transition stage follows, whithin which the stroke is influenced by the design of the pressure piece, whereas for the next stages of progressive force increase, the stroke is accomplished exclusively by the rubber spring's design and volumetric compression.
Fig. 3 shows more details about the design of a prior art pedal feel simulator. More specific, such a known simulator comprises a closing cover 1, a rubber spring 2, a pressure piece 3, a piston 4, a seal ring 5, and a steel spring 6 within a housing 7. Each part is an individual component and custom-built for each different brake pedal characteristic curve.
Fig. 4 shows a first embodiment of the inventive pedal feel simulator. Mainly, in this case, the pedal feel simulator comprises a sub-assembly wherein steel spring 6 is kept between the pressure piece 3 and the piston 4 by means of a plug E inserted into the piston 4. During the pre-assembling process, the installed dimension of the steel spring, namely its nominal length referenced by LO in Fig. 4, remain constant and not affected.
The plug 8 engages the end of the pressure piece 3 and is tight connected to the piston 4 either as a press fit connection or as a fix-in-place connection using glue or other filling material able to seal any gap and hold in place both components over the entire required range of temperature and pressure. Other possible technologies of connecting the plug to the piston are laser brazing for the case both plug 8 and piston 4 are made of metal, or ultrasonic plastic welding for the case both plug 8 and piston 4 are made of plastic. Using a molded plastic pressure piece 3, for example, with an end of a shaped profile inserted and clamped into the plug 8, costs can be kept low, and the assembling to the plug 8 can be done without creating any extra burs or particles on insertion. A particular mention is that the plug external diameter is larger than the main engagement diameter with the piston, this design having the purpose to ensure the integrity of the assembly in the event of higher-than-expected brake fluid pressures, which can push the plug completely into the piston, in which case the brake fluid has limited space to fill in the bore and act against the piston surface.
Fig. 5 illustrates a second embodiment of a pedal feel simulator according to invention, wherein the end of the pressure piece engages 3 a shaped profile of the plug 8.
However, while certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.
List of reference numbers 1 Closing cover 2 Rubber spring 3 Pressure piece Piston Sealing ring 6 Steel spring 7 Housing 8 Plug Brake fluid reservoir TMC Tandem master cylinder PE'S Pedal feel simulator PR Brake pedal piston rod P1 Primary piston PC Pressure chamber SS Secondary piston spring CV Cut valve V Simulator valve cp compensation port LS Linear stroke LO Nominal length of steel spring
Claims (10)
- Patent claims 1. Pedal feel simulator for an automotive electronic braking system, comprising: -a housing provided with an axial bore throughout its entire length, - a piston with an end subjected to hydraulic pressure, - a rubber spring deformable up to a limited extend, - a pressure piece placed between the steel spring and the rubber 10 spring, and - a steel spring positioned into the bore and placed between the pressure piece and the piston, - a closing cover closing the bore and limiting the travel of the rubber spring inside the bore, wherein the steel spring, the pressure piece and the piston form a sub-assembly, the steel spring being retained between the piston and the pressure piece by means of a plug inserted into the piston.
- 2. Pedal feel simulator according to claim 1, wherein the plug is inserted into the piston and tightly connected to the piston.
- 3. Pedal feel simulator according to claim 1, wherein the plug and the pressure piece are shaped profile and clamped together. 25
- 4. Assembly process of a pedal feel simulator, comprising the steps of: - providing a tight connection between a plug and a piston; - providing a sub-assembly formed by a steel spring, a pressure 30 piece and the piston provided with the plug, wherein the steel spring is retained between the pressure piece and the piston by means of the plug, -providing a final assembly by introducing the sub-assembly and a rubber spring in a housing provided with a bore and closing them inside with a closing cover.
- 5. Assembly process according to claim 4, whereby the installed dimension of the steel spring, namely its nominal length, remain constant during assembling.
- 6. Assembly process according to claim 4, whereby the connection 10 between the piston and the plug is a press fit connection.
- 7. Assembly process according to claim 4, whereby the connection between the piston and the plug is fix-in-place connection.
- 8. Assembly process according to claim 4, whereby in case the piston and the plug are both made of metal, the connection is obtained by laser brazing.
- 9. Assembly process according to claim 4, whereby in case the 20 piston and the plug are both made of plastic, the connection is obtained by ultrasonic plastic welding.
- 10. Assembly process according to claim 4, whereby the plug and the pressure piece have shaped profiles and are interconnected 25 by clamping.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1915022.6A GB2588221A (en) | 2019-10-17 | 2019-10-17 | Pedal feel simulator and an assembly process thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1915022.6A GB2588221A (en) | 2019-10-17 | 2019-10-17 | Pedal feel simulator and an assembly process thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201915022D0 GB201915022D0 (en) | 2019-12-04 |
| GB2588221A true GB2588221A (en) | 2021-04-21 |
Family
ID=68728387
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1915022.6A Withdrawn GB2588221A (en) | 2019-10-17 | 2019-10-17 | Pedal feel simulator and an assembly process thereof |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2588221A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114619047A (en) * | 2022-02-21 | 2022-06-14 | 国营芜湖机械厂 | Manufacturing method of rubber piston rod mold of opening mechanism |
| DE102023205385A1 (en) | 2023-06-07 | 2024-12-12 | Continental Automotive Technologies GmbH | simulator unit for a hydraulic braking device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030205932A1 (en) * | 2002-02-25 | 2003-11-06 | Chris Anderson | Master cylinder for an electro-hydraulic braking system comprising improved means of simulating the pedal feel and an electro-hydraulic braking system comprising such a master cylinder |
| JP2016078763A (en) * | 2014-10-21 | 2016-05-16 | 日信工業株式会社 | Stroke simulator and vehicle brake system |
| JP2017039409A (en) * | 2015-08-20 | 2017-02-23 | 日立オートモティブシステムズ株式会社 | Stroke simulator |
| US20180215361A1 (en) * | 2015-07-31 | 2018-08-02 | Hitachi Automotive Systems, Ltd. | Master cylinder unit |
-
2019
- 2019-10-17 GB GB1915022.6A patent/GB2588221A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030205932A1 (en) * | 2002-02-25 | 2003-11-06 | Chris Anderson | Master cylinder for an electro-hydraulic braking system comprising improved means of simulating the pedal feel and an electro-hydraulic braking system comprising such a master cylinder |
| JP2016078763A (en) * | 2014-10-21 | 2016-05-16 | 日信工業株式会社 | Stroke simulator and vehicle brake system |
| US20180215361A1 (en) * | 2015-07-31 | 2018-08-02 | Hitachi Automotive Systems, Ltd. | Master cylinder unit |
| JP2017039409A (en) * | 2015-08-20 | 2017-02-23 | 日立オートモティブシステムズ株式会社 | Stroke simulator |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114619047A (en) * | 2022-02-21 | 2022-06-14 | 国营芜湖机械厂 | Manufacturing method of rubber piston rod mold of opening mechanism |
| CN114619047B (en) * | 2022-02-21 | 2023-08-01 | 国营芜湖机械厂 | Manufacturing method of rubber piston rod die of opening mechanism |
| DE102023205385A1 (en) | 2023-06-07 | 2024-12-12 | Continental Automotive Technologies GmbH | simulator unit for a hydraulic braking device |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201915022D0 (en) | 2019-12-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100694524B1 (en) | Piston pump | |
| US5711151A (en) | Brake-pressure modulation device | |
| US10507812B2 (en) | Pedal travel simulator and hydraulic block including a pedal travel simulator | |
| EP2835297B1 (en) | Piston push rod assembly, master cylinder, and manufacturing method for piston push rod assembly | |
| MXPA06001733A (en) | Cylinder, in particular for a motor vehicle hydraulic brake system. | |
| US11180129B2 (en) | Hydraulic block for a hydraulic unit of a brake control system and method for the manufacture thereof | |
| GB2588221A (en) | Pedal feel simulator and an assembly process thereof | |
| CN114206696B (en) | Hydraulic block for a hydraulic unit of a hydraulic vehicle brake system | |
| JP2003508297A (en) | Brake booster with wall mounting means | |
| US20240017705A1 (en) | Pedal feel simulator | |
| EP2832597B1 (en) | Stroke simulator and bush for stroke simulator | |
| CN110525402B (en) | Master cylinder and brake-by-wire system | |
| EP0185165A1 (en) | Plastic master cylinder | |
| GB2241293A (en) | Actuating unit for an automotive vehicle anti-lock brake system | |
| CN114667245B (en) | Valve device | |
| CN110114252B (en) | Hydraulic block for a hydraulic unit of a brake actuating device of a hydraulic vehicle brake system | |
| US4669268A (en) | Master cylinder-reducing valve assembly | |
| EP4476105B1 (en) | Brake modulator with a relay valve cover plate | |
| CN107539299B (en) | Hydraulic block with hydraulic structural elements | |
| KR100987146B1 (en) | Master cylinder for electric hydraulic brake | |
| US5946914A (en) | Master cylinder reservoir retention means | |
| GB2588617A (en) | Pedal feel simulator | |
| JP6273820B2 (en) | Press fit fixing structure of valve unit | |
| GB2588222A (en) | Braking system with split stroke function for motor vehicles | |
| CN102416936A (en) | Fast fill tandem master cylinder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |