MASTER CYLINDER FOR BRAKING SYSTEM

Abstract

A double-entry master cylinder may comprise a housing having a first inlet, a piston base located within the housing, and a piston rod having a first end and a second end, where the first end of the piston rod is in contact with the piston base and the second end of the piston rod acts as a second inlet of the double-entry master cylinder, where the piston rod can be separated from the piston base.

Description

description; Figure 2C shows a schematic view of a third modality of a braking control system of the present description; Figure 3 shows a perspective view of a first modality of a double-entry master cylinder of the present description; Figure 4 shows an exploded view of the double-entry master cylinder from Figure 3; Figure 5 shows a cross-sectional view of the double-entry master cylinder of Figure 3 made along line 5-5 of Figure 3; Figure 6 shows a perspective view of a second modality of a double-entry master cylinder of the present description; and Figure 7 shows a cross-sectional view of the double-entry master cylinder of Figure 6 made along line 7-7 of Figure 6. Corresponding reference characters indicate corresponding parts in all different views. Although the figures represent variations of different features and components according to this description, the figures are not necessarily to scale, and certain features may have been exaggerated to better illustrate and explain this description. The examples presented herein are -5 illustrate embodiments of the invention, and the examples should not be interpreted as limiting the scope of the invention in any way. Detailed Description of the Invention To facilitate a better understanding of the principal elements of the invention, reference will now be made to the embodiments illustrated in the figures, which are described below. The embodiments described below are not intended to be exhaustive, nor to limit the invention to the precise form described in the following detailed description. Rather, the embodiments have been chosen and described so that others skilled in the art may benefit from their teachings. It is understood that this is not intended to limit the scope of the invention. The invention includes any further alterations and modifications to the illustrative devices and methods, and any further applications of the principles of the invention described that a person skilled in the art to which the invention relates could normally conceive. As shown in Figure 1, a vehicle 2 is described and configured for off-road vehicle applications, such that vehicle 2 is configured to traverse trails and other unpaved terrain. Although vehicle 2 is shown as a utility vehicle (UTV), it is within the scope of this description. -6that vehicle 2 may also be an all-terrain vehicle (ATV) with a saddle-type seat and handlebars, an electric vehicle, a tractor, a mechanically driven vehicle, or another type of motorized sports vehicle. Vehicle 2 generally includes a frame assembly 4 supporting a plurality of body panels 6 and supported on a ground surface by a plurality of ground contact elements 8. By way of illustration, the ground contact elements 8 include front ground contact elements 10 and rear ground contact elements 12. In one embodiment of vehicle 2, each of the front ground contact elements 10 includes a wheel assembly 10a and a tire 10b supported thereon. Similarly, each of the rear ground contact elements 12 may include a wheel assembly 12a and a tire 12b supported thereon.A front suspension assembly 27 can be operatively coupled to the front ground contact elements 10 and a rear suspension assembly 28 can be operatively coupled to the rear ground contact elements 12. Referring again to figure 1, vehicle 2 extends between a front part 14 and a rear part 16 along a longitudinal geometric axis L and supports an area -7 of the operator 18 between them. The operator area 18 includes seat 20 for at least the operator and can also accommodate one or more passengers. In one configuration, seat 20 includes baguette-type seats side by side, while in another configuration, seat 20 includes a bench-type seat. Behind the operator area 18 is a cargo area 22, supported by frame assembly 4 at the rear 16. As shown in Figure 1, the operator area 18 includes operator controls 24, such as the steering assembly 26, which may be operatively coupled to one or more of the ground contact elements 8. Additional operator controls 24 may include other inputs for controlling the operation of vehicle 2, as described later herein, such as an accelerator element or pedal (not shown), a foot brake element or pedal (not shown), and / or a handbrake actuator 28 (Figure 2A). More specifically, various operator controls 24 may affect the operation of a powertrain assembly (not shown) of vehicle 2.The powertrain assembly can be supported by the rear 16 of vehicle 2 and generally includes an engine (not shown), a transmission (not shown) operatively coupled to the engine, a front final drive element (not shown) operatively coupled to the frZfrenn / zznz / E / YiAi. -8 front ground contact elements 10 via the front half-shafts or axle shafts (not shown), and a rear final drive element (not shown) operatively coupled to the rear ground contact elements 12 via the rear half-shafts or axle shafts (not shown). A drive shaft (not shown) may be operatively coupled to the front final drive element at an input (not shown) to supply motive power from the engine and / or transmission to the front ground contact elements 10. The rear final drive element is operatively coupled to the engine and / or transmission to supply power from it to the rear ground contact elements 12. Referring now to Figures 2A-2C, vehicle 2 includes a braking system 40, comprising a front braking unit 42 and a rear braking unit 44. For illustrative purposes, the front braking unit 42 is generally located at the front 14 of vehicle 2 and is operatively coupled to the front ground contact elements 10, while the rear braking unit 44 is generally located at the rear 16 of vehicle 2 and is operatively coupled to the rear ground contact elements 12. The front braking unit 42 includes front brake discs (not shown) and front brake calipers (not shown). -9 operationally coupled to the front wheel assemblies 10a. The rear braking portion 44 includes rear brake discs (not shown) and rear brake calipers (not shown) operationally coupled to the rear wheel assemblies 12a. Referring to Figure 2A, a schematic view of a first modality 40a of the braking system 40 is shown, which is configured to provide single-application multi-wheel braking and a hydraulic locking mechanism. In this way, the braking system 40a is configured to apply braking force to all ground contact elements 10, 12 with a single input, as described later herein.The braking system 40a includes a handbrake master cylinder 4 6 coupled to the handbrake actuator 28 and a hydraulic locking mechanism 48 to provide a first input, a dual-input master cylinder 50, 50', which may or may not be operatively coupled to a braking control system (not shown), which may or may not include an anti-lock braking system (ABS) control module (not shown), and a foot brake element or pedal to provide a second input, a first splitter or linking element 52 configured to split the first input of the handbrake master cylinder 46 between the front ground contact elements 10 and / or the master cylinder. - 10 double inlet 50, 50', a hydraulic fluid reservoir 54, coupled to the double inlet master cylinder 50, 50' and configured to supply hydraulic fluid to the double inlet master cylinder 50, 50' when required, and a second splitter or linking element 56 configured to split an outlet of the double inlet master cylinder 50, 50' between the rear ground contact elements 12. For illustrative purposes, as shown in Figure 2A, the braking system 40a further includes a left front line or duct 64, a right front line or duct 66, a left rear line or duct 68 and a right rear line or duct 70, which are seamlessly coupled to the dual-inlet master cylinder 50, 50' through the splitters 52 and 56.In this way, the front left duct 64 smoothly couples the brake caliper of the front left ground contact element 10L with the double-entry master cylinder 50, 50', the front right duct 66 smoothly couples the brake caliper of the front right ground contact element 10R with the brake master cylinder 50, 50', the rear left duct 68 smoothly couples the brake caliper of the rear left ground contact element 12L with the double-entry master cylinder 50, 50', and the rear right duct 70 smoothly couples the brake caliper of the contact element with. - 11 the right rear floor 12R with the double-entry master cylinder 50, 50'. Referring again to Figure 2A, with respect to the rear braking unit 44, the lines 68, 70 are seamlessly coupled to the dual-inlet master cylinder 50, 50' via the splitter or linking element 56. For illustrative purposes, at least one line or linking duct 74 extends from the dual-inlet master cylinder 50, 50' to the linking element 56, so that the dual-inlet master cylinder 50, 50' is seamlessly coupled to both rear ground contact elements 12 via the linking duct 74 and the respective left and right rear lines 68, 70. Similarly, with respect to the front braking unit 42, the lines 64, 66 are seamlessly coupled to the dual-inlet master cylinder 50, 50' via the splitter or linking element 52.For illustrative purposes, at least one linking line or conduit 76 extends from the splitter element 52 to the dual-inlet master cylinder 50, 50', so that the handbrake master cylinder 46 is smoothly coupled to the dual-inlet master cylinder 50. Referring now to Figure 2B, a schematic view of a second mode 40b of the braking system 40 of vehicle 2 is shown, which is configured to provide single-application braking in frZfrenn / zznz / E / YiAi - 12 multiple wheels with a secondary braking and hydraulic locking mechanism. The second modality 40b is substantially similar to the first modality 40a of Figure 2A, except that the first divider 52 has been eliminated and the force from the handbrake element 28 (Figure 2A) is supplied to a tandem master cylinder 78 having a first outlet 80 fluidly coupled to the front ground contact elements 10 and a second outlet 82 fluidly coupled to the dual-inlet master cylinder 50, 50'. In addition, the second modality 40b includes a line or conduit 76' that couples the dual-inlet master cylinder 50, 50' to the tandem master cylinder 78 instead of the first divider 52, since the first divider 52 is eliminated. Referring now to Figure 2C, a schematic view of a third mode 40c of the vehicle 2 braking system 40 is shown, which is configured to provide an additional braking device for monitoring circuit failure. The third mode 40c is substantially similar to the second mode 40b, except that the third mode 40c includes a first divider 52, similar to the first mode 40a, and a differential pressure valve, switch, or combination valve 84 fluidly coupled to the tandem master cylinder 78, dual-inlet master cylinder 50, 50', and the first divider 52. Additionally, the third mode 40c includes - 13 two lines 76a and 76b that couple the double-entry master cylinder 50, 50' to the first divider 52 through the differential pressure switch 84. Specifically, a first of the lines 76, 76a couples the double-entry master cylinder 50, 50' to the differential pressure switch 84 and a second of the lines 76, 76b couples the differential pressure switch 84 to the first divider 52. Referring now to Figures 3-5, a first embodiment 50 of the double-entry master cylinder is shown in detail. In general, the double-entry master cylinder 50 includes a housing 90, a piston base 92 (Figures 4 and 5) located within the housing 90, a piston rod 94 in contact with the piston base 92, a thrust element 96 (i.e., a piston return spring) (Figure 5) received around a portion of the piston base 92, an end cap 98 located within the housing 90 around the piston rod 94, and an internal retaining element 100 (e.g., a snap ring) in contact with a first end 97 of the end cap 98 and configured to retain the end cap 98 within the housing 90. The housing 90 generally includes a first inlet 102 (Figure 3), a second inlet 104, a bleed screw opening 106 to receive a bleed screw 108, and a hydraulic fluid reservoir connector opening 110 configured to receive a connector from the reservoir. - 14 hydraulic fluid 112, an outlet 113, configured so as to provide pressurized hydraulic fluid to the divider 56, and ultimately to the rear ground contact elements 12, and at least one, illustratively two, mounting holes 115. As shown, the first inlet 102 of the housing 90 can be located along a side surface of the housing 90, such that a geometric center axis of the first inlet 102 is substantially perpendicular to a geometric center axis of the bleed screw opening 106.Furthermore, the mounting holes 115 of the housing 90 may be located along an upper surface of the housing 90 or along the same surface as the openings 106 and 108, as shown, whereas in other embodiments, the mounting holes 115 may be located along a lower surface of the housing 90 or along a surface opposite the openings 106 and 108, so that the mounting holes do not interfere with the inlets, etc., along the same surface. In various embodiments, the hydraulic fluid reservoir connector 112 may be incorporated into the housing 90 at a 90-degree angle, as shown, whereas in other embodiments, the connector 112 may be incorporated into the housing 90 at other angles or inclinations, such as 45 degrees, to allow for various packing constraints. - 15 The piston base 92 generally includes a first end 91 that is in contact with the piston rod 94, and a second end 93 that has an extension 114 received within the thrust element 96. The piston rod 94 generally includes a head 116 that is in contact with the first end 91 of the piston base 92 and a piston body 118 that extends out of the housing 90. The head 116 includes a collar 120 configured to be in contact with a second end 99 of the end cap 98. In this way, the piston rod 94 is separate and distinct from the piston base 92, so that the double-entry master cylinder 50 includes a two-piece piston assembly, rather than a one-piece assembly. Referring to Figures 6 and 7, a second embodiment 50' of the double-entry master cylinder is shown in detail. In general, the double-entry master cylinder 50' is substantially similar to the double-entry master cylinder 50, except that the first inlet 102' of the housing 90' of the double-entry master cylinder 50' coincides with the opening of the bleed screw 106', so that a geometric center axis of the first inlet 102' is coaxial with a geometric center axis of the opening of the bleed screw 106'. A bleed assembly 122, such as a bolt drilled with the bleed screw 108, may be used along the first inlet 102' so that the inlet and bleed coincide. - 16 During operation, and referring by way of example to figures 2A or 2C, as the operator applies a force Fi to the handbrake element 28, pressurized hydraulic fluid is transmitted to the divider 52 and subsequently, at least partially, to the dual-inlet master cylinder 50, 50' via pressurized hydraulic fluid. The pressurized hydraulic fluid enters the dual-inlet master cylinder 50, 50' through the first inlet 102, 102' and causes the piston base 92 to separate from the piston rod 94. The separation of the piston base 92 from the piston rod 94 results in the entire surface of the piston base 92 being exposed to the pressurized hydraulic fluid, causing the piston base 92 to transmit more force within the housing 90 of the dual-inlet master cylinder 50, 50'.That is, the pressurized hydraulic fluid is forced out through outlet 113 of the double-inlet master cylinder 50, 50' and towards the rear ground contact elements 12 with greater force and efficiency, resulting in uniform braking of the front and rear ground contact elements 10, 12. In other words, the interface between the piston rod head 116 of the piston rod 94 and the first end 91 of the piston base 92 can be separated so that the entire first end 91 of the piston base 92 is exposed to the pressurized hydraulic fluid. Because the hydraulic fluid - 17 from inlet 102, 102' is pressurized and is applied over the entire surface of the first end 91, the piston base 92 moves towards outlet 113 to provide hydraulic brake fluid to outlet 113 in order to brake the rear ground contact elements 12. That is, the braking of the rear ground contact elements 12 occurs at approximately the same time and with the same braking pressure as that applied to the front ground contact elements 10. Therefore, through the double-inlet master cylinder 50, 50', the ratio between the braking pressure applied to the front ground contact elements 10 and the braking pressure applied to the rear ground contact elements 12 is approximately 1:1. Referring again to Figures 2A-2C, an additional or alternative force F2 can be applied to the dual-inlet master cylinder 50, 50' through the foot brake element. When force F2 is applied to the foot brake element, a mechanical force is applied to the second inlet 104 at a first end 93 of the piston rod 94, so that the piston rod 94 and piston base 92 are moved within the housing 90 of the dual-inlet master cylinder 50, 50' and cause the pressurized hydraulic fluid to be transmitted to the rear ground contact element 12 through outlet 113. - 18 Additional details of the braking assembly 40 may be described in U.S. patent application serial number 15 / 471,469, filed March 28, 2017, entitled ANTI-LOCK BRAKE SYSTEM FOR ALL-TERRAIN VEHICLE (file number PLR-02-27 800.OOP), and U.S. patent application serial number 16 / 197,497, filed November 21, 2018, entitled ANTI-LOCK BRAKE SYSTEM FOR UTILITY VEHICLE (file number PLR-06-28332.02P), descriptions of which are expressly incorporated herein by reference in their entirety. Although the present invention has been described as having an exemplary design, it may be further modified within the nature and scope of this description. Therefore, this application is intended to cover any variations, uses, or adaptations of the invention that utilize its general principles. It is also intended to cover deviations from the present description that are within the customary or known practice of the art to which this invention belongs. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

Having described the invention as above, the following claims are claimed as property:

1. A double-entry master cylinder, characterized in that it comprises: a housing having a first inlet configured to transmit a hydraulic input and an outlet configured to transmit a hydraulic output; a piston base located within the housing; and a piston rod having a first end and a second end, wherein the first end of the piston rod is in contact with the piston base and the second end of the piston rod acts as a second inlet of the double-entry master cylinder, the second inlet being configured to transmit a mechanical input, wherein the piston rod can be separated from the piston base.

2. The double-entry master cylinder according to claim 1, characterized in that the piston base is located entirely within the housing.

3. The double-entry master cylinder according to claim 1, characterized in that it further comprises a thrust element, wherein the thrust element is received around at least a portion of the piston base. frZfrenn / zznz / E / YiAi 4. The double-inlet master cylinder according to claim 1, characterized in that it further comprises a bleed screw opening configured to receive a bleed screw and a hydraulic fluid reservoir connector opening configured to receive a hydraulic fluid reservoir connector.

5. The double-inlet master cylinder according to claim 4, characterized in that a central geometric axis of the first inlet is substantially perpendicular to a central geometric axis of the purge screw opening.

6. The double-inlet master cylinder according to claim 4, characterized in that a central geometric axis of the first inlet is coaxial with a central geometric axis of the purge screw opening.

7. The double-inlet master cylinder according to claim 1, characterized in that it further comprises an outlet, wherein a portion of the piston rod extends out of a first end of the housing and the outlet is situated around a second end of the housing.

8. A braking system, characterized in that it comprises: a first user inlet; a first master cylinder operatively coupled to the first user inlet; a second user inlet; a dual-inlet master cylinder operatively coupled to the first and second user inlets, wherein the dual-inlet master cylinder includes a housing having a first inlet, a piston base located within the housing, a piston rod in contact with the piston base, the piston rod being separable from the piston base within the housing, and an outlet configured to transmit a hydraulic output located downstream with respect to the piston rod and the piston base; and at least one splitter operatively coupled to the dual-inlet master cylinder.

9. The braking system according to claim 8, characterized in that the piston base is located entirely within the housing.

10. The braking system according to claim 8, characterized in that the double-inlet master cylinder further comprises a thrust element that is received around at least a portion of the piston base.

11. The braking system according to claim 8, characterized in that the at least one divider includes a first divider and a second divider, the first divider being located upstream with respect to the first inlet and the second divider being located downstream frZfrenn / zznz / E / YiAi -22 with respect to the outlet.

12. The braking system according to claim 8, characterized in that the piston base can be separated from the piston rod.

13. The braking system according to claim 8, characterized in that the first inlet is located along a first side of the housing.

14. The braking system according to claim 8, characterized in that the first inlet is located along an upper side of the housing.

15. The double-entry master cylinder according to claim 1, characterized in that the first entry is a first user entry and the second entry is a second user entry.

16. The double-inlet master cylinder according to claim 4, characterized in that a central geometric axis of the hydraulic fluid reservoir connector is substantially coaxial with a central geometric axis of the bleed screw opening.

17. The double-entry master cylinder according to claim 1, characterized in that the second end of the rod is directly coupled with the majority of a first side of the piston base.

18. The braking system according to claim 8, characterized in that the first user input is configured to transmit a hydraulic input and the second user input is configured to transmit a mechanical input.

19. The braking system according to claim 8, characterized in that the second end of the stem is directly coupled with the majority of a first side of the piston base.

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