TH33202A - Method for testing the internal combustion engine that is assembled - Google Patents

Abstract

DC60 (15/10/40) Method of testing the assembled state of an internal combustion engine and quickly and accurately judging whether there is at least one fault with the engine assembly. While the exhaust valve clearance (100) is closed and the crankshaft (18) is rotated at constant speed, the pressure in the exhaust valve clearance and the surge tank pressure (96) are detected by pressure detectors (106, 98) respectively. The assembled state of the engine (90) is tested according to the defined conditions of the two detected pressures. These defined conditions will be the crankshaft angle when the two pressures are at their maximum values, the crankshaft angle when the two pressures change from a steady state to an increasing or decreasing state, and so on. Based on those values, incorrect phase of the crankshaft and camshaft pulleys, incorrect clearance of the intake and exhaust valves, missing compression rings, etc., can be demonstrated. Method of testing the assembled state of an internal combustion engine and quickly and accurately judging whether there is at least one fault with the engine assembly. While the exhaust valve clearance (100) is closed and the crankshaft (18) is rotated at constant speed, the pressure in the exhaust valve clearance and the pressure in the surge tank (96) are detected by pressure sensors (106, 98), respectively. The assembled engine state (90) is tested according to the defined conditions of the two detected pressures. These defined conditions are the crankshaft angle when the two pressures are at their maximum values, the crankshaft angle when the two pressures change from a steady state to an increasing or decreasing state, and so on. According to these, incorrect phase of the crankshaft and camshaft pulleys, incorrect clearance of the intake and exhaust valves, missing compression rings, and so on can be demonstrated.

Claims (18)

1. The method of testing a at least partially assembled internal combustion engine with intake and exhaust valves consists of the following steps: driving the at least partially assembled engine with an external power source to increase engine pressure; continuously measuring the engine pressure while the at least partially assembled engine is driving; determining the engine timing based on the measured engine pressure when at least one defined condition of engine pressure change occurs in at least one of (a) the external intake valve clearance, which is connected to the intake valve and is not fed with externally pressurized air of the at least partially assembled engine, and (b) the external exhaust valve clearance, which is connected to the external valve and is not fed with externally pressurized air of the at least partially assembled engine; and judging, based on the determined engine timing, whether there is at least one error in the at least partially assembled engine. 2. Method under Claim 1: The decision-making process involves comparing the specified engine timing with a reference timing and deciding, based on the comparison, whether there is at least one error with the engine that is at least partially assembled. 3. The method under Claim 1, in which the measurement procedure consists of measurements depending on whether the engine timing is measured for (a) or (b) or both (a) and (b); at least one of the first engine timings when the release pressure in the release valve clearance is at its maximum value; the second engine timing when the external pressure changes from the first decreasing state to a steady state in which the release pressure does not change over time; the third engine timing when the release pressure changes from a steady state to the second decreasing state; the fourth engine timing when the intake pressure in the intake valve clearance is at its maximum value; and the fifth engine timing when the intake pressure changes from a steady state in which the intake pressure does not change over time to an increasing state. 4. Method pursuant to Claim 3: The determination procedure consists of demonstrating at least one error with the assembled engine, at least partially, by at least one of the positive or negative signs, and the actual value of the difference between at least one measured timing set from the first to fifth engine timings and one corresponding to the first, second, third, fourth, and fifth reference timings. 5. The method under Claim 3, in which the determination procedure involves the presentation of at least one fault with the assembled engine, at least partially, based on the combination of several defined engine timings selected from engine timings one through five, each of which shall differ from one corresponding reference timing first, second, third, fourth, and fifth. 6. The method under claim 1, in which at least one fault is found, includes at least one of the following: incorrect intake valve clearance; incorrect exhaust valve clearance; incorrect phase relationship between the crankshaft and camshaft; and a missing compression ring. 7. The method under claim 6 in which the phase relationship is incorrect between the crankshaft and camshaft consists of at least one phase relationship incorrect between the crankshaft and crankshaft pulley; phase relationship incorrect between the camshaft pulley and camshaft; and phase relationship incorrect between the driving gear and the driven gear. 8. The procedure under Claim 1, which also includes a procedure to close at least one passageway on the discharge valve side connecting the discharge valve and the discharge manifold, and the passageway on the inlet valve side connecting the inlet valve and the inlet manifold, where at least one of the external discharge valve passages and the external inlet valve passage contain at least one portion of the discharge valve side section of the closed discharge valve passage, respectively. 9. The method under Claim 1, which involves a procedure for determining the engine timing when at least one predetermined condition of engine pressure change occurs in the outside vent valve clearance, including the vent valve chamber and the vent manifold with a closed outlet. 10. The method under Claim 1, which includes a determination procedure consisting of setting engine timing in which at least one predetermined condition of engine pressure change occurs in the outside intake valve clearance as well as the internal clearance of the surge tank. 11. The method pursuant to claim 1, the determination procedure, consists of showing at least two faults from several engine faults which are at least partially assembled. 12. A method under Claim 1 in which at least one defined condition of engine timing change can occur at multiple engine timings corresponding to at least one of the following engine faults, and where the decision procedure includes the expression of at least one of the several faults based on at least one of (a) the defined engine timing deviation of at least one defined condition of change from the reference timing, and (b) a combination of at least two defined engine timing change preconditions that deviate from at least two reference timings, respectively. 13. The procedure under claim 12 also includes a procedure for determining that there is no fault with at least two predetermined engine assemblies when the engine timing of each of the two predetermined conditions of engine pressure change is equal to the reference timing and the cancellation of the determination procedure. 14. The procedure under Claim 12, in which multiple engine timings are performed, consists of at least one engine timing that corresponds to each of at least two of the multiple faults, and where the procedure is demonstrated by applying one of the multiple engine timings that corresponds to the smallest number of faults before the other engine timings. 15. The method pursuant to claim 12, the procedure of which involves using one of several engine timing settings corresponding to at least one fault that has been displayed and confirmed as easily identifiable by the operator before setting any other engine timings. 16. The procedure under claim 12, which involves performing one of several engine timing settings corresponding to at least one fault most easily corrected by the operator, before performing any other engine timing settings. 17. The procedure under Claim 1, where the driving procedure consists of rotation, using a freely rotating device, of the crankshaft of the engine that is at least partially assembled and causing oscillation to occur on the piston of the engine in the cylinder of the engine that is at least partially assembled while at least one of such intake valve clearances and exhaust valve clearances is isolated from the atmosphere, and where the judgment procedure consists of determining that there is at least one fault with the at least partially assembled state of the engine according to at least one of (a) the pressure in at least one of such intake valve clearances and exhaust valve clearances and is measured while one corresponding intake and exhaust valves are closed, and (b) at least one of the engine start and end times of the closed state of one of the intake and exhaust valves which corresponds to one of such intake and exhaust valve clearances. 18. The procedure under Claim 1, in which an assembled engine, at least partially, consists of several cylinders, each containing an intake and exhaust valve, whereby the measurement procedure consists of measuring, for each at least two of such several cylinders, at least one of (a) the pressure value in at least one of the outside intake valve clearances for each at least two cylinders and the outside exhaust valve clearance for each at least two cylinders, where such pressure value is sufficient for at least one of the predetermined conditions of such change, and (b) the engine timing, where such pressure value is sufficient for at least one of the predetermined conditions of such change; whereby the procedure consists of comparing at least one of the pressure values and engine timing of the first one of at least two cylinders with at least one of the pressure values and engine timing of the second one of at least two such cylinders; and whereby the judgment procedure consists of determining that there is at least one fault with the assembled engine when at least one such pressure value and engine timing of such first cylinder is not equal to at least one such pressure value and engine timing of such second cylinder.