DESC:FORM 2

THE PATENTS ACT 1970
(39 OF 1970)
AND
THE PATENTS RULES 2003

COMPLETE SPECIFICATION
(see Section 10; Rule 13)

A TEST RIG FOR PRESSURE TESTING OF VARIOUS ALUMINIUM CASTING USED IN HIGH POWER DIESEL ENGINE

ENGINE FACTORY AVADI
Unit OF Armoured Vehicle Nigam Limited
Government of India Enterprise
Ministry of Defence
Avadi, Chennai, 600054
Tamil Nadu, India

The following specification particularly describes the invention and the manner in which it is to be performed.
A TEST RIG FOR PRESSURE TESTING OF VARIOUS ALUMINIUM CASTING USED IN HIGH POWER DIESEL ENGINE

TECHNICAL FIELD
[0001] The present invention pertains to the field of mechanical engineering. More particularly the present invention relates to the design and development of a specialized test rig for conducting pressure tests on critical castings used in high-power diesel engines.

BACKGROUND OF THE INVENTION
[0002] In the manufacturing industry, particularly in the production of high-power diesel engines for military applications, the quality and integrity of engine components are of utmost importance. These engines are designed with a high proportion of aluminum castings to minimize weight while maximizing performance. However, the sourcing of these castings from various vendors has led to the recurrent issue of casting defects.
[0003] The defects observed in the castings, including blowholes, hot tears, internal cracks, and porosity, pose a substantial risk to the operational efficiency and safety of the engines. These defects often become apparent during the machining process, leading to delays in production schedules and increased manufacturing costs. The presence of such flaws not only compromises the structural integrity of the engine components but also results in engines being sent back to the manufacturing unit for rectification. This rework process is both time-consuming and costly, undermining the overall efficiency of the production line.
[0004] To address these challenges, a reliable method for detecting casting defects before machining becomes imperative. The solution lies in the development of a pressure testing test rig specifically designed for the rigorous testing of these critical castings.
[0005] The development and implementation of this pressure testing rig are driven by the need to ensure the highest quality standards in engine manufacturing. By rigorously testing each casting, the invention aims to eliminate the occurrence of defects, thereby reducing the likelihood of engine failures and the associated rework costs. This proactive approach not only enhances the reliability and performance of the engines but also contributes to the overall efficiency and cost-effectiveness of the manufacturing process.

OBJECTS OF THE INVENTION
[0006] The primary object of this invention is to provide a specialized test rig for the pressure testing of critical castings used in high-power diesel engines.
[0007] Yet another object is to facilitate a comprehensive quality control process that enhances the reliability and performance of diesel engines.
[0008] Another objective is to reduce the incidence of engine failures and the associated costs of rework by ensuring that all castings are thoroughly tested and verified to be defect-free before being inducted into the assembly unit.
[0009] Yet another object of the invention is to provide a cost-effective and efficient method for pressure testing castings, thereby improving the overall manufacturing process, reducing production delays, and enhancing the operational efficiency of the manufacturing unit.

SUMMARY OF THE INVENTION
[0010] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
[0011] According to an embodiment of the present invention, a test rig for pressure testing critical castings used in high-power diesel engines comprises a stainless steel water tank with a heat-resistant coating. This tank features a low-level alarm, an inner tank isolated from an outer tank, and heat-resistant insulated material packed between the walls of the outer and inner tank. Additionally, the rig includes a polypropylene water pump with a capacity of 5 cubic meters per hour, a motor with a power rating of 3 HP, an air compressor, hydraulic and air hoses with quick-release couplings for easy connection and disconnection, a water level indicator, glycerine-filled pressure gauges, a digital temperature indicator, an oil immersion type tubular heater with a digital temperature controller designed to achieve a temperature of 90°C within approximately 30 minutes, water hoses and connectors with quick-release couplings, and ball valve controls, water return pipes, tank drain plugs, a motor switch board, water inlet and outlet hoses, and a compressed air line.
[0012] According to an embodiment of the present invention, the test rig includes a low-level alarm that activates when the water level is just above the heater level, ensuring protection against dry running. Additionally, the heater is capable of heating the water to a temperature range between 80°C and 95°C. A digital temperature controller is also incorporated to maintain the water temperature within this specified range.
[0013] According to an embodiment of the present invention, the hydraulic hoses are connected through connectors designed to suit the inlet and outlet passages of the components being tested, ensuring a secure and leak-free connection. Furthermore, ball valve controls are included for regulating the flow of water into and out of the castings being tested.
[0014] According to an embodiment of the present invention, a method for pressure testing critical castings used in high-power diesel engines using the described test rig comprises the steps of filling the water tank with water and heating it to a temperature of 80°C to 95°C using the oil immersion type tubular heater. Hot water is then circulated through the casting inlet at a pressure of 3 to 5 Kgf/cm² for a duration of 5 minutes. The water pressure and temperature are monitored using pressure gauges and a digital temperature indicator to ensure consistent testing conditions. Defects such as blowholes, hot tears, internal cracks, and porosity are detected by observing for leaks or drops in pressure during the test duration.
[0015] According to an embodiment of the present invention, different types of castings are tested under specific conditions. For example, the upper crank case is tested at 2.5 to 3 Kgf/cm² pressure and 70°C to 80°C temperature for 4 minutes, the lower crank case at the same pressure and temperature for 2 minutes, the cylinder head at 4 to 5 Kgf/cm² pressure and 80°C to 90°C temperature for 4 minutes, the cylinder jacket at 3 to 5 Kgf/cm² pressure and 80°C to 90°C temperature for 5 minutes, and the cylinder block crank case at 5 Kgf/cm² pressure and 80°C to 90°C temperature for 5 minutes.
[0016] According to an embodiment of the present invention, the method further includes the step of using the compressed air line to assist in the circulation of water through the casting, ensuring thorough testing and detection of defects.
[0017] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating the preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0019] FIG. 1 illustrates a test rig for pressure testing of various aluminium casting used in high power diesel engine, according to the present invention.
[0020] Although the specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.

LIST OF ITEMS
No. Description
1 Water tank
2 Ball valve control
3 Pressure gauges
4 Water return pipe
5 Water pump
6 Motor
7 Tank drain plug
8 Motor switch board
9 Water inlet hose
10 Water close valve
11 Digital temperature indicator
12 Water heater
13 Water level indicator
14 Water outlet hose
15 Compressed air line
16 Quick release coupling
17 Water return pipe

DETAILED DESCRIPTION OF THE INVENTION
[0021] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practised are shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense. The various embodiments of the present invention provide for a test rig for pressure testing of various aluminium casting used in high power diesel engine.
[0022] According to an embodiment of the present invention, a test rig for pressure testing critical castings used in high-power diesel engines comprises a stainless steel water tank with a heat-resistant coating and a capacity of approximately 1000 liters. The tank dimensions are 1500 x 1000 x 750 mm, featuring a low-level alarm, an inner tank isolated from an outer tank, and heat-resistant insulated material packed between the walls of the outer and inner tank.
[0023] According to an embodiment of the present invention, the test rig includes a polypropylene water pump with suction and discharge ports of 1 inch each, capable of handling water temperatures up to 100°C and pressures up to 6 bar, with a capacity of 5 cubic meters per hour. Additionally, a motor with a power rating of 3 HP, operating at 2850 RPM, and designed for a 3-phase, 415 V, 50 Hz power supply is incorporated.
[0024] According to an embodiment of the present invention, the test rig further includes an air compressor, hydraulic and air hoses specifically high-pressure double wire braided steam hydraulic hoses with quick-release couplings for easy connection and disconnection. It also features a water level indicator, glycerine-filled pressure gauges with a 10 bar dial, a digital temperature indicator, and an oil immersion type tubular heater operating at 230 V. This heater has a digital temperature controller designed to achieve a temperature of 90°C within approximately 30 minutes.
[0025] According to an embodiment of the present invention, the test rig also features water hoses and connectors, including quick-release couplings and galvanized iron pipelines with a size of ¾ inch. Furthermore, it includes ball valve controls, water return pipes, tank drain plugs, a motor switch board, water inlet and outlet hoses, and a compressed air line.
[0026] According to an embodiment of the present invention, the water tank further includes a low-level alarm that activates when the water level is just above the heater level, ensuring protection against dry running. Moreover, the heater is capable of heating the water to a temperature range between 80°C and 95°C.
[0027] According to an embodiment of the present invention, the test rig comprises a digital temperature controller that maintains the water temperature within the range of 80°C to 95°C. The hydraulic hoses are connected through connectors designed to suit the inlet and outlet passages of the components being tested, ensuring a secure and leak-free connection. Additionally, ball valve controls are included for regulating the flow of water into and out of the castings being tested.
[0028] According to an exemplary embodiment of the present invention, the testing rig for the evaluation of critical castings utilized in high-power diesel engines prior to machining processes. These castings, comprising five distinct types, exhibit substantial dimensions and mass, with measurements approximately 1 meter in length, 0.5 meters in height, and a weight of 135 kilograms. Recurring defects reported by end-users, particularly seepages within the castings, necessitate the return of engines to the manufacturing facility for rectification.
[0029] According to an embodiment of the present invention, a method for pressure testing critical castings used in high-power diesel engines using the described test rig comprises the steps of filling the water tank with water and heating it to a temperature of 80°C to 95°C using the oil immersion type tubular heater. Hot water is circulated through the casting inlet at a pressure of 3 to 5 Kgf/cm² for a duration of 5 minutes. Water pressure and temperature are monitored using pressure gauges and a digital temperature indicator to ensure consistent testing conditions. Defects such as blowholes, hot tears, internal cracks, and porosity are detected by observing for leaks or drops in pressure during the test duration.
[0030] According to an embodiment of the present invention, different types of castings are tested under specific conditions. For instance, the upper crank case is tested at 2.5 to 3 Kgf/cm² pressure and 70°C to 80°C temperature for 4 minutes, while the lower crank case is tested at the same pressure and temperature for 2 minutes. The cylinder head is tested at 4 to 5 Kgf/cm² pressure and 80°C to 90°C temperature for 4 minutes, the cylinder jacket at 3 to 5 Kgf/cm² pressure and 80°C to 90°C temperature for 5 minutes, and the cylinder block crank case at 5 Kgf/cm² pressure and 80°C to 90°C temperature for 5 minutes.

Type of casting Testing parameters
Pressure
(Kgf/cm2) Temperature
(oC) Duration
(minutes)
Upper crank case 2.5 to 3 70 to 80 4
Lower crank case 2.5 to 3 70 to 80 2
Cylinder head 4 to 5 80 to 90 4
Cylinder Jacket 3 to 5 80 to 90 5
Cylinder block crank case 5 80 to 90 5

[0031] According to an embodiment of the present invention, the method further comprises the step of isolating the inner tank from the outer tank using heat-resistant insulated material to maintain the desired water temperature and prevent heat loss. Quick-release couplings facilitate easy connection and disconnection of the water hoses, enhancing the efficiency of the testing process. Additionally, the method includes using the compressed air line to assist in the circulation of water through the casting, ensuring thorough testing and detection of defects.
[0032] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such as specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.
[0033] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications. However, all such modifications are deemed to be within the scope of the claims.
,CLAIMS:We Claim:
1. A test rig for pressure testing critical castings used in high-power diesel engines, comprising:
a stainless steel water tank with a heat-resistant coating, featuring a low-level alarm, an inner tank isolated from an outer tank, and heat-resistant insulated material packed between the walls of the outer and inner tank;
a polypropylene water pump with a capacity of 5 cubic meters per hour;
a motor with a power rating of 3 HP;
an air compressor;
a hydraulic and air hoses, with quick-release couplings for easy connection and disconnection;
a water level indicator;
a glycerine-filled pressure gauges;
a digital temperature indicator;
an oil immersion type tubular heater operating with a digital temperature controller designed to achieve a temperature of 90°C within approximately 30 minutes;
a water hoses and connectors, including quick-release couplings; and
a ball valve controls, water return pipes, tank drain plugs, motor switch board, water inlet and outlet hoses, and a compressed air line.
2. The test rig of claim 1, wherein the low-level alarm that activates when the water level is just above the heater level, ensuring protection against dry running.
3. The test rig of claim 1, wherein the heater is capable of heating the water to a temperature range between 80°C and 95°C.
4. The test rig of claim 1, the digital temperature controller that maintains the water temperature within the range of 80°C to 95°C.
5. The test rig of claim 1, wherein the hydraulic hoses are connected through connectors designed to suit the inlet and outlet passages of the components being tested, ensuring a secure and leak-free connection.
6. The test rig of claim 1, the ball valve controls for regulating the flow of water into and out of the castings being tested.
7. A method for pressure testing critical castings used in high-power diesel engines using the test rig of claim 1, comprising the steps of:
filling the water tank with water and heating it to a temperature of 80°C to 95°C using the oil immersion type tubular heater;
circulating hot water through the casting inlet at a pressure of 3 to 5 Kgf/cm² for a duration of 5 minutes;
monitoring the water pressure and temperature using the pressure gauges and digital temperature indicator to ensure consistent testing conditions;
detecting any defects such as blowholes, hot tears, internal cracks, and porosity by observing for leaks or drops in pressure during the test duration.
8. The method of claim 7, wherein different types of castings are tested under specific conditions, including:
Upper crank case: 2.5 to 3 Kgf/cm² pressure, 70°C to 80°C temperature, 4 minutes duration;
Lower crank case: 2.5 to 3 Kgf/cm² pressure, 70°C to 80°C temperature, 2 minutes duration;
Cylinder head: 4 to 5 Kgf/cm² pressure, 80°C to 90°C temperature, 4 minutes duration;
Cylinder jacket: 3 to 5 Kgf/cm² pressure, 80°C to 90°C temperature, 5 minutes duration;
Cylinder block crank case: 5 Kgf/cm² pressure, 80°C to 90°C temperature, 5 minutes duration.
9. The method of claim 7, further including the step of:
using the compressed air line to assist in the circulation of water through the casting, ensuring thorough testing and detection of defects.

Dated this 29th day of August 2024.

Saravanan Gopalan
Registered Patent Agent
(INPA – 3249)