DESC:DESCRIPTION

A HYDRO-PNEUMATIC PARKING BRAKE SYSTEM AND PROCESS FOR MOTOR GRADERS

FIELD OF INVENTION
[001] The present subject matter described herein, relates to a hydro-pneumatic parking brake system and process for motor graders. The present subject matter, in particularly, relates to a hydro-pneumatic parking brake system and process to improve the holding performance and reduce operator fatigue on motor graders equipped with air operated brake system
BACKGROUND
[002] Background description includes information that may be useful in understanding the present subject matter. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed subject matter, or that any publication specifically or implicitly referenced is prior art.

[003] Motor graders are used in various applications in the Mining and Construction fields. In India, graders need to meet the RTO and DGMS regulations. Small and midsized graders are used for operations like Material spreading, moving rolling, mixing and grading in construction fields. Larger graders are used in various surface opencast mines for making the roads on which heavy trucks and dumpers are transporting coal and other minerals extracted from the earth.
[004] In graders, hydraulic or air operated brake system is installed for slowing down and stopping. Air brake system is preferred for its simple construction, low cost and easy serviceability. Parking brake is used to hold the equipment in slopes and for parking.
[005] As per the vehicle safety standards, parking brakes are designed to be fail safe. To meet this, spring applied air / hydraulic release type parking brakes are used. Motor grader having medium size work blade uses the air system for regular service brakes and internally expandable shoe type parking brake which is actuated by ratchet pinion mechanism.
[006] Presently, disc type spring applied hydraulically released parking brake in place of internally expandable shoe type parking brake is being designed for improved holding performance, resulting in need of new actuation system.
[007] As an example of the prior art, US Patent. No: US8663058B2 discloses a brake assembly for a mobile machine is disclosed. The brake assembly may have a stationary spindle, and a main brake housing annularly connected at a first axial end to the stationary spindle and at least partially forming a first control chamber. The brake assembly may also have a park brake housing annularly connected to a second axial end of the main brake housing and at least partially forming a second control chamber, and at least one piloting feature disposed between an inner annular surface of the park brake housing and an outer annular surface of the stationary spindle.
[008] Existing prior art such as US8924115B2 describes control system for controlling a braking system. The control system includes a parking brake operatively to at least one wheel, a park brake override mechanism operatively associated with the parking brake, an inching pedal operatively coupled to a transmission, a shift lever operatively coupled to the transmission, at least one sensor operatively coupled to the parking brake to detect when the parking brake is engaged, at least one sensor operatively coupled to the inching pedal to detect a depression of the inching pedal, and at least one sensor operatively coupled to the shift lever for detecting at least one of a forward or reverse gear selection. The control system further includes a controller operatively coupled to the at least one sensors to receive corresponding signals and adapted to control the engagement of the parking brake when the inching pedal is depressed and the at least one of the forward or reverse gear selections is desired.
[009] Most of the present day motor graders are equipped with hydraulically operated accumulator assisted parking brake system only. But additional cooling system needs to be introduced in hydraulic brake system due to its higher heat generation. Also, complexity of the system is high resulting in need of higher skill for maintenance and service.
[0010] Pneumatic or air operated brake system offers ease of maintenance and low cost over hydraulic brake system due to its simplicity.
[0011] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
[0012] Thus, there remains a need for an air actuated hydraulically released type parking brake system. Also, there remains a need for process to improve the holding performance and reduce operator fatigue on motor graders.

OBJECTS OF THE DISCLOSURE
[0013] In view of the foregoing limitations inherent in the state of the art, some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[0014] It is an object of the present disclosure to propose a hydro-pneumatic parking brake system and process for motor graders.

[0015] It is another object of the present disclosure to propose a system which uses a spring applied hydraulically released type parking brake in an air operated brake system motor graders.
[0016] It is yet another object of the present disclosure to propose a hydro-pneumatic parking brake system and process for motor graders which ensures safety when main line air pressure drops below prescribed limit.

[0017] It is yet another object of the present disclosure to propose a hydro-pneumatic parking brake system and process with soft finger touch apply / release of parking brake.

[0018] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY
[0019] One or more drawbacks of existing parking brake system, and additional advantages are provided through the present hydro-pneumatic parking brake system and process for motor graders as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
[0020] The present disclosure relates to a hydro-pneumatic parking brake system comprising a compressor configured to be driven by engine which generates pressurized air. An air dryer configured to remove the moisture contents and function as a safety valve by maintaining system pressure. A main reservoir configured to store the compressed air. A system protection valve configured with inbuilt non return valves and supply air to parking brake line. A parking brake switch configured to operate inside a cabin. A parking brake solenoid valve configured to be energized and cuts the air supply to a booster. The booster configured to receive pressurized air supply from parking brake solenoid valve and convert the air pressure into hydraulic pressure required to release the parking brake on other side at a spring brake. Spring force comes into action which leads to application of parking brake due to the lack of air pressure and oil return to the brake oil tank.
[0021] The present disclosure relates to a process for operating hydro-pneumatic parking brake system for motor grader, comprising the steps of: configuring a compressor driven by engine which generates pressurized air. Configuring an air dryer to remove the moisture contents and function as a safety valve by maintaining system pressure. Configuring a main reservoir to store the compressed air. Configuring a system protection valve with inbuilt non return valves and supply air to parking brake line. Configuring a parking brake switch for operating inside a cabin. Configuring a parking brake solenoid valve to be energized and cutting the air supply to a booster. Configuring the booster to receive pressurized air supply from parking brake solenoid valve and converting the air pressure into hydraulic pressure required for releasing the parking brake on other side at a spring brake actuator and actuating the spring force which leads to application of parking brake due to the lack of air pressure and returning the oil to the brake oil tank.

[0022] Other objects, features and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF DRAWINGS
[0023] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0024] FIG. 1 illustrates hydro-pneumatic parking brake system for motor grader in accordance with an embodiment of the present disclosure;
[0025] FIG. 2 illustrates flow chart of hydro-pneumatic parking brake process for motor grader in accordance with an exemplary embodiment of the present disclosure.
[0026] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0027] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0028] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.

[0029] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

[0030] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0031] Embodiments explained herein pertain to a hydro-pneumatic parking brake system 100 for motor grader 102. FIG. 1 illustrates hydro-pneumatic parking brake system hydro-pneumatic parking brake system 100for motor grader102in accordance with an embodiment of the present disclosure. The hydro-pneumatic parking brake system 100includes a compressor 1, an air dryer 2, a main reservoir 3, a system protection valve 4, a parking brake switch 5,a parking brake solenoid valve 6, a booster 7, a brake oil tank 8 and a spring brake actuator 9.

[0032] In one embodiment the compressed air from compressor 1 enters the parking brake solenoid valve 6 through the air dryer 2, the main reservoir 3 and the system protection valve 4. The parking brake solenoid valve 6 controls the flow of air from system protection valve to the booster 7. The booster 7 receives pressurized air supply from the parking brake solenoid valve 6 and convert the air pressure into hydraulic pressure required to release the parking brake on other side at the spring brake actuator 9. When the parking brake switch 5 is operated inside the cabin, the parking brake solenoid valve 6 is energized and cuts the air supply to the booster 7. Due to the lack of air pressure, spring force comes into action which leads to application of the parking brake. Further, the oil return to the brake oil tank 8.

[0033] In one embodiment the hydro-pneumatic parking brake system 100 and process 200 for motor graders 102is disclosed. To improve the holding performance and reduce operator fatigue on motor graders 102equipped with air operated brake system, hydro-pneumatic parking brake system 100 is disclosed. The spring applied hydraulically released disc type is used for parking brake application. When the vehicle is in OFF condition, due to the spring force the parking brake is applied on condition only. When engine starts, the compressor 1 builds the air pressure inside the system. The compressed air enters the parking brake solenoid valve6through the air dryer 2, the main reservoir 3 and the protection valve 4. The booster 7 receives pressurized air supply from parking brake solenoid valve 6and boosts the hydraulic pressure on other side required to soft finger touch apply at spring brake actuator 9.

[0034] In one embodiment the process 200 for operating hydro-pneumatic parking brake system 100 for motor grader 102, comprising the steps of: configuring a compressor 1driven by engine which generates pressurized air. Configuring an air dryer 2 to remove the moisture contents and function as a safety valve by maintaining system pressure. Configuring a main reservoir 3 to store the compressed air. Configuring a system protection valve 4with inbuilt non return valves and supply air to parking brake line. Configuring a parking brake switch 5 for operating inside a cabin; configuring a parking brake solenoid valve 6to be energized and cutting the air supply to a booster 7.Configuring the booster 7 to receive pressurized air supply from parking brake solenoid valve 6 and converting the air pressure into hydraulic pressure required for releasing the parking brake on other side at a spring brake actuator 9 and actuating the spring force which leads to application of parking brake due to the lack of air pressure and returning the oil to the brake oil tank 8.

[0035] Referring to FIG. 2 illustrating flow chart of hydro-pneumatic parking brake process 200for motor grader102. At step 201, compressor 1 driven by engine generates pressurized air. At step 202, air dryer 2 removes the moisture contents and acts like safety valve by maintaining the system pressure. At step 203, main reservoir 3 stores the compressed air. At step 204, a system protection valve 4fitted with inbuilt non return valves ensures system safety and supply air to parking brake line. At step 205, parking brake solenoid valve6connect / disconnects the pressurized air to booster 7based on the parking brake switch signal. At step 206, booster 7converts air pressure in to hydraulic pressure by drawing the brake oil from the brake oil tank8. At step 207, the spring brake actuator9 releases the parking brake when hydraulic pressure is available and applies the parking brake through spring force when there is no hydraulic pressure.
[0036] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0037] Although the above detailed description illustrates hydro-pneumatic parking brake system for motor grader. It will be clear to one of skill in the art that the invention discloses about motor graders equipped with air operated brake system Thus, the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given above.
TECHNICAL ADVANTAGE
[0038] The present disclosure proposes a hydro-pneumatic parking brake system with simple construction, low cost and easy serviceability.
[0039] The present disclosure proposes the hydro-pneumatic parking brake system for producing enough pressure.
[0040] The present disclosure proposes the hydro-pneumatic parking brake system without cooling system.
[0041] The present disclosure proposes the hydro-pneumatic parking brake system which improves holding performance.

[0042] Furthermore, each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0043] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0044] Furthermore, those skilled in the art can appreciate that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0045] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0046] While the foregoing describes various embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. The scope of the present disclosure is determined by the claims that follow. The present disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
,CLAIMS:WE CLAIM:

1. A hydro-pneumatic parking brake system (100), comprising
a compressor (1) configured to be driven by engine which generates pressurized air;
an air dryer (2) configured to remove the moisture contents and function as a safety valve by maintaining system pressure;
a main reservoir (3) configured to store the compressed air,;
a system protection valve (4) configured with inbuilt non return valves and supply air to parking brake line;
a parking brake switch (5) configured to operate inside a cabin;
a parking brake solenoid valve (6) configured to be energized and cuts the air supply to a booster (7);
the booster (7) configured to receive pressurized air supply from parking brake solenoid valve (6) and convert the air pressure into hydraulic pressure required to release the parking brake on other side at a spring brake actuator (9); wherein
spring force leads to application of parking brake due to the lack of air pressure and oil return to the brake oil tank (8).
2. The hydro-pneumatic parking brake system (100) as claimed in claim 1, wherein the compressed air from the compressor (1) enters the parking brake solenoid valve (6) through air dryer (2), the main reservoir (3) and the system protection valve (4).
3. The hydro-pneumatic parking brake system (100) as claimed in claim 1, wherein the parking brake solenoid valve (6) connect and disconnects the pressurized air to the booster (7) based on the parking brake switch signal.
4. The hydro-pneumatic parking brake system (100) as claimed in claim 1, wherein the booster (7) converts air pressure in to hydraulic pressure by drawing the brake oil from the brake oil tank (8).
5. A process (200) for operating hydro-pneumatic parking brake system (100) for motor grader (102), comprising the steps of:
configuring a compressor (1) driven by engine which generates pressurized air;
configuring an air dryer (2) to remove the moisture contents and function as a safety valve by maintaining system pressure;
configuring a main reservoir (3) to store the compressed air;
configuring a system protection valve (4) with inbuilt non return valves and supply air to parking brake line;
configuring a parking brake switch (5) for operating inside a cabin;
configuring a parking brake solenoid valve (6) to be energized and cutting the air supply to a booster (7);
configuring the booster (7) to receive pressurized air supply from parking brake solenoid valve (6) and converting the air pressure into hydraulic pressure required for releasing the parking brake on other side at a spring brake actuator (9); and
actuating the spring force which leads to application of parking brake due to the lack of air pressure and returning the oil to the brake oil tank (8).