DESC:“SYSTEM AND METHOD FOR VOLUMETRIC MEASUREMENT OF WATER JACKETS”
Field of the invention
The present invention relates to cylinder blocks of an internal combustion engine, and more particularly provides a system and a method for volumetric measurement of water jackets of the cylinder blocks at the end of production line.
Background of the invention
An internal combustion engine discharges high amount of heat energy thereby increasing the overall temperature of the engine. Excessive thermal expansion reduces the overall efficiency and performance of the internal combustion engine, and may also lead to engine failure. Hence, it is desired for the internal combustion engine to have an internal cooling system to achieve uniform cooling of the cylinder blocks for preventing undue or local thermal expansions of various parts of the cylinder block.
Water-cooled internal combustion engine are available in the market wherein the cylinder block is constructed to have therein a water jacket through which cooling water from the radiator flows therebetween the cylinder blocks for achieving uniform cooling of the cylinder blocks and thereby cooling the engine. However, in the water-cooled internal combustion engine, any interruption or blockages in the flow of cooling water leads to ineffective cooling of the cylinder block and the combustion chamber situated therein, thereby affecting the engine performance and causing failure of the engine. Hence, the water-cooled internal combustion engine requires constant monitoring of the volume and flow of the coolant, i.e. continuous monitoring of the level and flow of the cooling water present inside the water jacket is required to avoid engine failures.
Prior art patent US4430891A discloses a method of measuring the volume of a test chamber by comparing it with a reference chamber of known volume. The method includes sealingly closing both chambers, maintaining the temperatures of the two chambers substantially equal, injecting accurately related quantities of a gas into each chamber, comparing the pressures in each chamber and then reading the difference as a function of the volume of the test chamber, and thereafter reading the rate of change of the pressure difference in the two chambers as a function of chamber leakage and disregarding the volume measurement if the rate exceeds a determined value.
Prior art patent US4448065A discloses a method and an apparatus for pneumatically measuring the volume of combustion chamber spaces in cylinder heads. Accordingly, pressurized air is supplied to the workpiece space and the pressure is compared with the predetermined nominal pressure corresponding to a known nominal combustion chamber volume.
Prior art patent US2270505A disclosesa volume checking fixture and particularly relates to checking, comparing, and measuring the volumes of the combustion chambers of an internal combustion engine in the cylinder head.
The above cited prior arts disclose various methods and apparatus for measuring volume inside cylinder head compression chamber. However, none of the above cited prior arts discloses a method for constant monitoring and measurement of the internal volume of the water jacket which is present surrounding the cylinder blocks. The internal volume of the water jacket variesdue to accumulation of sand in the internal cavities of water jackets during casting process, leading to either reduction or an increase in the volume of the water jacket which ultimately affects circulation of the flow of cooling liquid inside the water gallery. Further, accumulation of hard sand particles or formation of large cavities during casting process in the cooling medium of the water jackets also leads to blockages in the water pump and also inside the water jacket, thereby restricting uniform flow of coolant therebetween the cylinder blocks affecting cooling of the engine. Although there have been a number of prior arts relating to the volume measurement of the cylinder head spaces, such configurations does not provides full or partilal blockages detection in water jackets of cylinder block on production line. Further, the conventional water jacket leak test machine available in the market can check only the leak rate of the water jackets, though there may be accumulation of sand or large cavities formed during casting process that goes undetected. Accumulation of sand particles in the water jackets can lead to improper flow of cooling media inside the water jacket, leading to rejection of the cylinder blocks at final buyoff stage of machining line, and also affecting the engine performance by causing engine over-heating, and affecting friction and mileage parameters of the engine.
Therefore, there exists a need to provide a testing setup addressing the aforementioned drawbacks of existing technologies and products. Accordingly, there exists a need to provide a system and a method for monitoring and measuring the internal water gallery of the cylinder blocks, and measuring and detecting the blockages present inside the water jackets for allowing free flow of the coolant therebetween the cylinder blocks thereby improving performance of the internal combustion engine.
Objects of the invention
The primary object of present invention is to detect and prevent blockages in a water jacket of the cylinder blocks in water-cooled internal combustion engine.
Another object of the present invention is to prevent engine overheating and engine failure by ensuring effective cooling of an internal combustion engine.
Yet another objective of the present invention is to reduce rejection of internal combustion engine components at final buyoff stage of machining line.
Still another objective of the present invention is to minimize the occurrence of failure in water pump and other internal combustion engine parts at the time of engine testing.
Still another objective of the present invention is to address shortcoming associated with interrupted flow of coolant and improper volume of water gallery, affecting other engine parameters including friction, exhaust gas temperature, lubricating oil and viscosity effect on engine torque.
Summary of the invention
The present invention provides a system for volumetric measurement of water jacket of a cylinder block in a water-cooled internal combustion engine, and a method thereof. The system is useful for detection of blockages in the water jackets if any. The system for volumetric measurement of water jacket is installed and integrated within a differential pressure leak testing unit of the production line, which is conventionally used for testing water jacket leakages. Once the test component enters the leak testing unit embodying the volumetric measurement system, the volumetric testing of water jacket is done first and then the component undergoes differential pressure leak testing. If the water jacket volume is less than the standard value and it is not showing any leakages in the differential pressure leak test, then it is concluded that the discrepancy in volume reading is due to blockages in the water jacket.
Brief description of the drawings
The objectives and advantages of the present invention will be more clearly understood from the following description of the invention taken in conjunction with the accompanying drawings, wherein;
Figure 1 shows a flow chart of a machining process of a diesel engine cylinder block including the step of volumetric testing of a water jacket followed by water jacket leakage testing, in accordance with the present invention;
Figure 2 shows the details of leak test measurement step integrated with volumetric measurement of water jacket, in accordance with the present invention;
Figure 3 shows a block diagram of a system for volumetric measurement of water jackets of a cylinder block, in accordance with the present invention;
Figure 4 shows a top view of a cylinder block with water jackets, in accordance with the present invention;
Figure 5 shows a perspective view of a cylinder block with water jackets, in accordance with the present invention; and
Figure 6 shows a flow chart of method for volumetric measurement of water jackets of a cylinder block, in accordance with the present invention.
Detailed description of the invention
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
The present invention provides a system and a method for volumetric measurement of water jackets of cylinder block in an internal combustion engine. The system and the method are used in conjunction with the existing water jacket leak testing unit. The system and the method help in monitoring the volume of the water jacket, along with detection of blockages inside the water jacket, thereby allowing uninterrupted flow of cooling water for improving engine performance and reducing engine failure due to overheating.
The term “engine” used herein refers to an internal combustion engine where combustion of fuel occurs with an oxidizer, usually air, in a combustion chamber that is an integral part of the engine. As the engine generates a high amount of heat energy, leading to overheating, a mechanism is needed for cooling the engine and preventing failure of the engine, preferably using either water, or air as the coolants to reduce the temperature of the engine. In a water-cooled engine, a water jacket (50), as shown in figure 4 and figure 5 is provided surrounding the cylinder blocks (60) present within the engine, for circulating a cooling fluid, particularly for circulating cooling water therein, thereby directly transferring heat generated by the engine to the cooling water.
The term “master component” used herein refers to a reference water jacket of a cylinder block and the “test component” refers to the cylinder block water jacket under test. Volume of the water jacket of the master component is taken as a reference volume for comparing it with the volume of test component.
The term “master chamber” used herein refers to a chamber having volume same as that of the water jacket of master component. In pneumatic circuit, the first master chamber and the second master chamber are connected to the volumetric testing unit in parallel along with the master component and the test component. The first master chamber and the second master chamber are constantly maintained at test pressure between two measurement cycles.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Referring to figure 1A, there is shown a flow chart of a machining process of a diesel engine cylinder block including the step (200) of volumetric testing of a water jacket followed by water jacket leakage testing. In a conventional operation sequence, leakage testing of the water jacket is done using a differential pressure method. However, conventional leakage testing using the differential pressure method in an existing leak testing system detects only the leakages present in the water jackets, whereas any blockages in the water jackets is left undetected. The proposed invention adds a step (200) of volumetric testing of water jackets to the conventional machining process of a diesel engine cylinder block. Details of step (200) are shown in figure 2.
Now, referring to figure 3, a system (100) for volumetric measurement of the water jacket of cylinder block (hereinafter referred as, “the system (100)”), in accordance with the present invention is disclosed. The system (100) is integrated and installed within an existing water jacket leak testing unit in a production process along with differential pressure leak testing unit, for check the internal volume of the water jackets of the cylinder block after final machining. The system (100) comprises of a volumetric test unit (10), a first master chamber (20A), a second master chamber (20B), a master component (30) and a test component (40). In an embodiment, the first master chamber (20A) and the second master chamber (20B) are of a volume same as that of the master component (30). The volumetric test unit (10) is adapted for comparing the pressure between two master chambers (20A and 20B) and also between the master component (30) and the test component (40). The master chambers (20A and 20B) and the master component (30) have a predetermined known control volume, and are used as controls for comparing and measuring the volume of the test component (40). The system further comprises of an air injecting means (5) adapted for injecting accurately measured quantities of pressurized air into the master chambers (20A and 20B), the master component (30) and into the test component (40). . In pneumatic circuit, the first master chamber (20A) and the second master chamber (20B) are connected to the volumetric testing unit in parallel along with the master component (30) and the test component (40). The first master chamber (20A) and the second master chamber (20B) are constantly maintained at test pressure between two measurement cycles. The first master chamber (20A) and the second master chamber (20B), being maintained at constant pressure, charge the master component (30) and the test component (40) respectively, and the volumes of the master component (30) and the test component (40) are compared by the volumetric test unit (10). After a short stabilization time, the new differential pressure measurement is proportional to the difference between test component (40) and the master component (40). Then system shows the leak rate in CC/min or in Pascal or in selected unit.
In another aspect, the invention provides a method (300) for volumetric measurement of the water jackets (hereinafter referred as “the method (300)”). The method (300) is used for detection of blockages within the water jacket. The method (300) is explained in conjunction with the system (100).
The method (300) includes a calibration cycle and a test cycle. The system (100) is first calibrated before actual use for measuring volume of the test component (40).
At step (210), the method (200) includes connecting the volumetric test unit (10) with the first master chamber (20A) and the second master chamber (20B).
At step (220), the master chambers (20A and 20B) are charged with pressurized air having 0.7 bar pressure.
At step (230), the air supply is cut off and the system is kept for balancing and testing. Differential pressure transducer compares the volume of master chambers (20A and 20B), if the volume difference is within specified limit then the system is at equilibrium state. With step (130), the method (200) completes the calibration cycle, after which, a test cycle starts for measurement of volume of the test component (40).
At step (240), the method (200) includes connecting the volumetric test unit (10) with the master component (30) and the test component (40).
At step (250), the pressurized air having 0.7 bar pressure from the first master chamber (20A) and the second master chamber (20B) is dumped into the master component (30) and the test component (40) respectively, with constant pressure.
At step (260), the differential pressure transducer measures the he pressure between master component (30) and test component (40) by back pressure method and gives result in terms of pressure loss or volume loss. If the difference between back pressures is within limit then the test component volume is said to be within specified limit.
If the difference is within specified limit then volume of the test component (40) is said to be within limit ( ± 15cc/min), and it is sent further for assembly
Thus, the present invention provides a system (100) and a method (300) for volumetric measurement along with leakage testing of the water jackets of the cylinder block in an internal combustion engine. The system can be retrofitted within an existing leakage testing machine.
Advantages of the present invention
• The system and the method help in reducing rejection of engine components at final buyoff stage of machining line.
• Minimization of water pump and other engine parts failure in engine testing and field.
• Uniform cooling of engine due to efficient flow and quantity of cooling media in clean water jacket ports.
• The system and the method help in maintaining uniform performance of engine and optimum qu helps to overcome engine issues occurring due to poor water gallery quality particularly engine overheating, friction, exhaust gas temperature, lubricating oil viscosity and effect on engine torque.
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.
,CLAIMS:We Claim:
1. A system (100) for volumetric measurement of a test component (40), the test component being a water jacket under test, of a cylinder block in an internal combustion engine, the system (100) integrated within a differential pressure leak testing unit, the system (100) comprising:
a master component (30) being a reference water jacket of known volume,
at least two identical master chambers (20 A and 20B) adapted for pressurizing the master component (30) and the test component (40) respectively, and having volume same as the master component (30);
an air injecting means (5) being capable of injecting pressurized air into master chambers (20A and 20B);
a volumetric test unit (10) being adapted for comparing the pressures within two master chambers (20A and 20B) and also the pressures within the master component (30) and the test component (40);
wherein, the first master chamber (20A) and the second master chamber (20B) are connected to the volumetric testing unit in parallel, along with the master component (30) and the test component (40), in the pneumatic circuit;
the first master chamber (20A) and the second master chamber (20B), being maintained at constant pressure, charge the master component (30) and the test component (40) respectively, and the pressures and volumes of the master component (30) and the test component (40) are compared by the volumetric test unit (10).

2. A method (300) for volumetric measurement of test component (40) for assessment of blockages therein , the test component (40) being a water jacket of a cylinder block in an internal combustion engine, the method (300) comprising:
connecting the volumetric test unit (10) with the first master chamber (20A) and the second master chamber (20B);
charging the master chambers (20A and 20B) with pressurized air having 0.7 bar pressure;
cutting off the air supply and allowing the system to attain equilibrium;
connecting the volumetric test unit (10) with the master component (30) and the test component (40);
charging the master component (30) and the test component (40) with the pressurized air from the first master chamber (20A) and the second master chamber (20B) respectively;
measuring the pressure difference between the master component (30) and test component (40) by back pressure method to give the result in terms of pressure loss or volume loss.
Dated this 29th day of July 2017
Prafulla Wange
(Agent for Applicant)
IN-PA/2058