DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
MODULAR TEST RIG SYSTEM FOR TESTING STEERING CYLINDER WITH INTEGRAL VALVE

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, India

The following specification particularly describes the invention and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

[001] The present invention claims priority from Indian patent Provisional Application 202041008963 filed on 02 March 2020.

TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to a test rig system to evaluate load characteristics of a steering cylinder with integral directional control valve.
BACKGROUND
[003] Generally, no-load functional test is carried out by actuating the input pins of a steering cylinder with the help of a long suitable mechanical lever and continuous supply of hydraulic oil to the inlet port of the steering cylinder. Therefore, evaluation of the output force of the steering cylinder becomes difficult. In addition, in present practice a mechanical lever is used to actuate input pin of the steering cylinder thereby extension and retraction stroke of the steering cylinder is checked separately. Thus, there is a need to carry out load testing easily in order to evaluate load characteristics of steering cylinder.
OBJECT OF THE INVENTION
[004] It is an object of the present invention to measure output force of a steering cylinder.
[005] It is an object of the present invention to measure actual steering efforts done by steering wheel when steering cylinder is loaded.
[006] It is an object of the present invention to calculate value of force generated at out pin by actuating input pin (part of directional control valve) to overcome the resistive load.
[007] It is an object of the present invention to build support from a base plate assembly and a box structure assembly for modular test rig for the steering cylinder.
SUMMARY
[008] Before the present system and method are described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to modular test rig for load testing of steering wheel, and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[009] A modular test rig assembly comprises a steering wheel, a steering cylinder, a hydraulic power pack, a loading master cylinder, a gear box, a connecting rod, shutoff valves, a pressure sensor, a torque sensor, Hydraulic hoses, a pitman arm, an immersion type thermometer. A rigid box structure configured with linkage mechanism to actuate input pin of the steering cylinder with in-built valve. A steering wheel is mounted on a gear box and the steering cylinder configured with a hydraulic loading master cylinder in order to evaluate actual output force of the steering cylinder. The output force of the steering cylinder is calculated by multiplying the load pressure value with the corresponding piston area and annular area of the loading master cylinder

BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing:
[0011] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0012] Figure 1 illustrates a frame assembly of a modular test rig system.
[0013] Figure 2 illustrates a test set up of modular test rig system with frame assembly.
[0014] Figure 3 illustrates a coupling of steering cylinder and loading master cylinder.
[0015] Figure 4 illustrates a hydraulic test circuit to evaluate load test for steering cylinder.
[0016] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion 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
[0017] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0018] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0019] Referring now to figure 1, in one aspect of present subject matter, a modular test rig is mounted on a cylinder test rig. The modular test rig comprises a base plate assembly (1), a box structure assembly (4) and a tie-rod of cylinder (3) test rig. The base plate (1) is clamped on the tie rods (3) of cylinder test rig and the box structure assembly (4) is mounted on the base plate assembly (1). Therefore, the reaction force generated during a load test of a steering cylinder is smoothly transferred to the cylinder test rig.
[0020] Referring to figure 2 and 3, the test set-up comprises of a base plate assembly (1), a steering gear box (2), a steering cylinder tie rod (3), a box structure (4), a loading master cylinder (5), a steering wheel (6), a steering effort measurement wheel (7), a steering cylinder (8) and a pitman arm (9). The steering wheel (6), gear box assembly (2), pitman arm (9) and one end of steering cylinder (8) is configured to the box structure assembly (4) and the other end of steering cylinder (8) is configured with master cylinder, wherein master cylinder acts as a variable hydraulic loading device.
[0021] Referring to figure 4, a hydraulic test circuit comprises of a pump (20), a motor (21), a power pack (13), a tank (14), a relief valve (15), a steering cylinder (8), a piston (16), piston rod (17), a directional control valve (18), a non-return valve (19), a output pin (12), input pin (11), V1, V2, V3 – shutoff valves. The Rotary motion of the steering wheel (6) gets converted into linear motion through steering gear box (2), pitman arm (9) and steering cylinder tie rod (3) linkages. The clockwise and anti-clockwise rotation of the steering wheel (6) causes steering cylinder (8) to extend and retract respectively.
[0022] A input pin (11) (part of directional control valve) is configured with steering wheel (6) by using the mechanical linkages in order to control the distribution of pressurized oil, which further fed to the relevant side of the steering cylinder piston (16) and enables power steering control. By using hydraulic power pack (13), pressurized oil is supplied to inlet port of steering cylinder (8) and piston side and / or rod side of loading master cylinder (5). Once the pressurized oil is supplied the steering wheel (6) is rotated fully in forward and reverse directions in order to measure and store the values of steering cylinder (8) inlet pressure, loading master cylinder (5) pressure and steering effort. The steering wheel sensor is configured on the steering wheel (6) to measure actual steering effort, the pressure transducers are mounted on loading master cylinder (5) and on steering cylinder inlet port line to measure pressure of loaded steering cylinder (8). Applied inlet pressure to the steering cylinder (8) is directly proportional to the force required to overcome the resistive load. The output force of steering cylinder (8) may be calculated by multiplying the load pressure value with the corresponding piston area and annular area of the loading master cylinder (5). The process or methodology to determine load characteristic of steering cylinder (8) is mention below.
[0023] At first step, the shut off valves V2 and V3 may be closed. At second step, the shut off valve V1 may open and prefill the load master cylinder (5) using the hydraulic power pack (13). At third step, once the pre-filling gets completed, the valve V1 may be closed. At fourth step the valve V3 may open completely. At fifth step the steering cylinder input pressure may be set by adjusting the power pack relief valve (15). At sixth step the steering wheel (6) may be operated during which the valve V2 gets gradually open at predefined load value with respect to input pressure. At seventh step the valve V3 may be closed completely. At eighth step, repeat the step two to five and the steering wheel (6) may be operated in order to capture the load characteristics and the steering effort, wherein captured data is stored into a storage unit. At ninth step repeat steps one to eight by applying different range of pressures.
[0024] Further, the invention can be used, but not limited to, in the following applications.
[0025] A test rig system for testing steering cylinder with integral valve comprises of input pin (11) is configured to be connected to steering wheel (6) by mechanical linkages to control distribution of pressurized oil to steering cylinder piston (16) for enabling power steering control. The rotary motion of said steering wheel (6) is configured to be converted into linear motion through steering gear box (2), a pitman arm (9) and steering tie rod (3) linkages. The power pack is configured to supply pressurized oil to inlet port of steering cylinder (8) and piston side and / or rod side of loading master cylinder (5). The steering wheel (6) is configured to rotate fully in forward and reverse direction on receiving pressurized oil in steering cylinder to measure and store the values of steering cylinder inlet pressure, loading master cylinder pressure and steering effort. The steering wheel (6) is configured with steering wheel sensor to measure actual steering effort. The loading master cylinder (5) and steering cylinder inlet port line are configured with pressure transducers to measure pressure of loaded steering cylinder (8). The output force of steering cylinder (8) is configured to be calculated by multiplying the load pressure value with the corresponding piston area and annular area of the loading master cylinder (5). The applied inlet pressure to the steering cylinder (8) is configured to be directly proportional to the force required to overcome the resistive load.
[0026] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0027] Some object of the present invention is suitable to evaluate load testing of hydraulic actuators.
[0028] Some object of the present invention enables easily add-on to the existing cylinder test rig.
[0029] REFERENCE NUMERALS:

Element Description Reference Numeral
Base plate assembly 1
Steering gear box 2
Steering cylinder tie rod 3
Box structure 4
Loading master cylinder 5
Steering wheel 6
Steering effort measurement wheel 7
Steering cylinder 8
Pitman arm 9
Connecting rod 10
Input pin 11
Output pin 12
Power pack 13
Tank 14
Relief valve 15
Piston 16
Piston rod 17
Direction control valve 18
Non return valve 19
Pump 20
Motor 21
Shut-off valves V1,V2,V3

,CLAIMS:
1. A test rig system for testing steering cylinder with integral valve comprises of:
a box structure assembly (4) configured for mounting a steering wheel (6), a gear box assembly (2), a pitman arm (9), a steering tie rod (3) and one end of a steering cylinder (8);
a base plate assembly (1) configured for a mounting connecting rod (10) and box structure assembly (4);
a steering cylinder (8) configured with a piston (16), a piston rod (17), a direction control valve (18), a non-return valve (19), a input pin (11) and output pin (12);
a loading master cylinder (5) configured to act as a variable hydraulic loading device and for mounting other end of the steering cylinder (8);
plurality of shut-off valves (V1.V2,V3) to stop the supply of oil; and
a power pack (13) configured with a tank (14), a pump (20) , a motor (21) and relief valve (15) to supply oil for testing.
2. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein rotary motion of said steering wheel (6) is configured to be converted into linear motion through steering gear box (2), a pitman arm (9) and steering tie rod (3) linkages.
3. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein said input pin (11) is configured to be connected to steering wheel (6) by mechanical linkages to control distribution of pressurized oil to steering cylinder piston (16) for enabling power steering control.
4. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein said power pack is configured to supply pressurized oil to inlet port of steering cylinder (8) and piston side and / or rod side of loading master cylinder (5).
5. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein said steering wheel (6) is configured to rotate fully in forward and reverse direction on receiving pressurized oil in steering cylinder to measure and store the values of steering cylinder inlet pressure, loading master cylinder pressure and steering effort.
6. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein said steering wheel (6) is configured with steering wheel sensor to measure actual steering effort.
7. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein said loading master cylinder (5) and steering cylinder inlet port line are configured with pressure transducers to measure pressure of loaded steering cylinder (8).
8. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein the output force of said steering cylinder (8) is configured to be calculated by multiplying the load pressure value with the corresponding piston area and annular area of the loading master cylinder (5).
9. The test rig system for testing steering cylinder with integral valve as claimed in claim 1, wherein applied inlet pressure to the said steering cylinder (8) is configured to be directly proportional to the force required to overcome the resistive load.