{
  "$type": "site.standard.document",
  "description": "A combustion pressure data collection system for a multi-cylinder engine. The cylinder pressure sensors directly detect a combustion pressure of respect cylinders, the charge amplifier unit (10) converts a charge signal into a voltage signal and has an automatic correction function for…",
  "path": "/patents/1078948",
  "publishedAt": "2005-03-30T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F02D35/023",
    "FUJI HEAVY IND LTD [JP]"
  ],
  "textContent": "A combustion pressure data collection system for a multi-cylinder engine. The cylinder pressure sensors directly detect a combustion pressure of respect cylinders, the charge amplifier unit (10) converts a charge signal into a voltage signal and has an automatic correction function for automatically correcting the voltage output level so that the level is set to the same level before and after cylinder pressure sensor generates a charge signal. Negative drifts at the zero point (2mV) are due to charge leakage from capacitance Cx. Correction is with amplifier A2 and field effect transistor Q1. Positive drifts at the zero point are due to the large temperature changes. Correction is with comparators C1, C2 and timer T1. The charge amplifier unit (10) of the of the respective cylinder is connected to the channel switching unit (MUX) (Multiplexer). A channel for actuating to be measured is selected from signals of a plurality of channels supplied from the charge amplifier units (10) in response to a channel selection signal output from an electronic engine control unit, and combustion pressure data are output to the electronic engine control unit from the cylinder of the channel, thereby combustion pressure data can be effectively collected by a simple arrangement without complex processing, for improving combustion efficiency to reduce harmful exhaust emissions.",
  "title": "Combustion pressure data collection system with multi-cylinder engine with charge amplifiers with correction circuits"
}