US 6,711,944 B2Granted

Method of testing assembled internal combustion engine

AssigneeToyota Jidosha Kabushiki Kaisha

InventorsNaoyuki Maruta, Nobuaki Suzuki

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Abstract

A 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 assembling of the engine. While an exhaust-valve side space is closed and a crank shaft is rotated at a constant speed, the pressure in the exhaust-valve side space and the pressure in a surge tank are detected by pressure sensors, respectively. The assembled state of an engine is tested based on the predetermined conditions of the detected two pressures. Those predetermined conditions may be the crank-shaft angles when the two pressures take respective maximal values, the crank-shaft angles when the two pressures change from their constant states to their increasing or decreasing states, etc. Based on those values, incorrect phases of crank and cam pulleys, incorrect clearances of intake and exhaust valves, missing of a compression ring, etc. can be identified.

Claims13

Dependent claims

A method of testing an engine including a cylinder, a piston, a crank shaft, an intake valve and an exhaust valve, comprising the steps of:

rotating the crank shaft using an external power source and thereby reciprocating the piston in the cylinder while at least one of (i) an external intake-valve side space communicating with the intake valve and not supplied with pressurized air and depressurized air from outside the engine and (ii) an external exhaust-valve side space communicating with the exhaust valve and not supplied with pressurized air and depressurized air from outside the engine is isolated from an atmosphere,
continuously measuring, while the crank shaft is rotated, a pressure in said at least one of the intake-valve side and exhaust-valve side spares that is isolated from the atmosphere,
determining, based on the continuously measured pressure, at least one of (a) a pressure occurring to said at least one of the intake-valve side and exhaust-valve side spaces, when at least one of the corresponding intake and exhaust valves is closed, and (b) at least one of a starting and an ending timing of a closed state of at least one of the corresponding intake and exhaust valves, and
evaluating a state of the engine based on the determined at least one of (a) the pressure in said at least one of the intake-valve side and exhaust-valve side spaces and (b) the at least one of the starting and ending timings of the closed state of the at least one of the corresponding intake and exhaust valves.

1 more element

A method of testing an engine including a cylinder, a piston, a crank shaft, an intake valve and an exhaust valve, comprising the steps of:

rotating the crank shaft using an external power source and thereby reciprocating the piston in the cylinder while at least one of (i) an external intake-valve side space communicating with the intake valve and not supplied with pressurized air from outside the engine and (ii) an external exhaust-valve side space communicating with the exhaust valve and not supplied with pressurized air from outside the engine is isolated from an atmosphere,
continuously measuring, while the crank shaft is rotated, a pressure in said at least one of the intake-valve side and exhaust-valve side shapes that is isolated from the atmosphere,
determining, based on the continuously measured pressure, at least one of (a) a pressure occurring to said at least one of the intake-valve side and exhaust-valve side spaces, when at least one of the corresponding intake and exhaust valves is closed, and (b) at least one of a starting and an ending timing of a closed state of at least one of the corresponding intake and exhaust valves, and
evaluating a state of the engine based on the determined at least one of (a) the pressure in said at least one of the intake-valve side and exhaust-valve side spaces and (b) the at least one of the starting and ending timings of the closed state of the at least one of the corresponding intake and exhaust valves,
wherein said at least one of the intake-valve and exhaust-valve side spaces comprises the exhaust-valve side space, and the evaluating step comprises evaluating the state of the engine based on the pressure in the exhaust-valve side space that is measured while the exhaust valve should have closed,
wherein the evaluating step comprises judging that the exhaust valve has closed incompletely, when the pressure in the exhaust-valve side space changes while the exhaust valve should have closed.

3 more elements

A method of testing an engine including a cylinder, a piston, a crank shaft, an intake valve and an exhaust valve, comprising the steps of:

rotating the crank shaft using an external power source and thereby reciprocating the piston in the cylinder while at least one of (i) an external intake-valve side space communicating with the intake valve and not supplied with pressurized air from outside the engine and (ii) an external exhaust-valve side space communicating with the exhaust valve and not supplied with pressurized air from outside the engine is isolated from an atmosphere,
continuously measuring, while the crank shaft is rotated, a pressure in said at least one of the intake-valve side and exhaust-valve side spaces that is isolated from the atmosphere,
determining, based on the continuously measured pressure, at least one of (a) a pressure occurring to said at least one of the intake-valve side and exhaust-valve side spaces, when at least one of the corresponding intake and exhaust valves is closed, and (b) at least one of a starting and an ending timing of a closed state of at least one of the corresponding intake and exhaust valves, and
evaluating a state of the engine based on the determined at least one of (a) the pressure in said at least one of the intake-vale side and exhaust-valve side spaces and (b) the at least one of the starting and ending timings of the closed state of the at least one of the corresponding intake and exhaust valves,
wherein the evaluating step comprises a state-change-timing depending evaluating step for evaluating the state of the engine based on said at least one of the starting and ending timings of the closed state of said at least one of the intake and exhaust valves that corresponds to said at least one of the intake-valve and exhaust valve-side spaces that is isolated from the atmosphere, said at least one of the starting and ending timings of the closed state of said at least one valve comprising at least one of a first state-change timing when the pressure in said at least one space changes from a changing state to a constant state and a second state-change timing when the pressure in said at least one space changes from the constant state to the changing state.

2 more elements

A method of testing an engine including a cylinder, a piston, a crank shaft, an intake valve and an exhaust valve, comprising the steps of:

rotating the crank shaft using an external power source and thereby reciprocating the piston in the cylinder while at least one of (i) an external intake-valve side space communicating with the intake valve and not supplied with pressurized air from outside the engine and (ii) an external exhaust-valve side space communicating with the exhaust valve and not supplied with pressurized air from outside the engine is isolated from an atmosphere,
continuously measuring, while the crank shaft is rotated, a pressure in said at least one of the intake-valve side and exhaust-valve side spaces that is isolated from the atmosphere,
determining, based on the continuously measured pressure, at least one of (a) a pressure occurring to said at least one of the intake-valve side and exhaust-valve side spaces, when at least one of the corresponding intake and exhaust valves is closed, and (b) at least one of a starting and an ending timing of a closed state of at least one of the corresponding intake and exhaust valves, and
evaluating a state of the engine based on the determined at least one of (a) the pressure in said at least one of the intake-valve side and exhaust-valve side spaces and (b) the at least one of the starting and ending timings of the closed state of the at least one of the corresponding intake and exhaust valves,
wherein the rotating step comprises an opposite-direction rotating step for rotating, using the external power source, the crank shaft of the engine in an opposite direction opposite to a normal direction in which the crank shaft is rotated when the engine is actually operated by firing.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/244,387Filed 17 Sep 2002 · division
Priority: JP 8-19085819 Jul 1996
Published: US 2003/0019283 A130 Jan 2003
Granted: 30 Mar 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01M 15/09
Testing internal-combustion engines: by monitoring pressure in fluid ducts, e.g. in lubrication or cooling parts
G01M 15/106
By monitoring exhaust gases: using pressure sensors
F02B 2275/18
Other engines, components or details, not provided for in other groups of this subclass: dOHC [Double overhead camshaft]
G01M
Testing static or dynamic balance of machines or structures

Family

PCT/JP97/02463Parent of this division · filed 15 Jul 1997
US 2003/0019283 A1Pre-grant publication · published 30 Jan 2003
Application09/214,936Parent of this division
US 2002/0007668 A1Published application
US 6,481,269 B2Related patent
US 6,711,944 B2This patent

From the US filing history. Foreign family members aren’t listed.