CN2037468U

CN2037468U - Blow-by detector of engine

Info

Publication number: CN2037468U
Application number: CN 88207677
Authority: CN
Inventors: 李昕沂
Original assignee: COMMUNICATIONS SCIENCE INST OF HEBEI PROV
Current assignee: COMMUNICATIONS SCIENCE INST OF HEBEI PROV
Priority date: 1988-06-25
Filing date: 1988-06-25
Publication date: 1989-05-10

Abstract

The utility model relates to a blow-by detector of engine, which comprises a sensor and a hot bulb breeze device. The hot bulb breeze device is a product sold in market, and the sensor is composed of sampling tube, a side pipe, a wind speed probe, an air inlet pipe and a communicating tube. The blow-by detector of engine can exactly measure fluid of ultratelescopic meteor level, and can effectively separate foul fluid from instruments to be measured. The utility model can be widely used to detect the intervals among the engine pistons, piston rings and cylinder jackets as well as to test the flow rate of foul gas.

Description

Blow-by detector of engine

A kind of pick-up unit that is used for detection of engine cylinder blow by amount belongs to field of measuring technique.

At present, do not understand body measurement piston, piston ring and steel-jacket gap and often adopt indirect method, promptly obtained related parameter by the approach of measuring crankcase gas leakage.Because no instrumentation, often with gas meter, diaphragm flowmeter, small-bore worm gear flowmeter or float type flow meter are used as substituting instrument.But have dirt (interior oily, impurity, moisture content etc. are easy to the measuring contamination instrument because of measured.) pulse and measure little characteristics, thereby be difficult to utilize and substitute instrument and accurately measure, perhaps cause instrument damage; In addition, because surveying instrument is easy to contaminatedly, also be not easy to routine inspection instrument as engine.

The purpose of this utility model provides a kind of engine air leak amount pick-up unit of special use, and it can accurately measure the air leak amount between piston and cylinder sleeve, and has the pollution of not being afraid of, the advantage of easy operating.

The purpose of this utility model realizes in the following manner.Design a kind of gas blowby sensor of special use, it becomes the dirty gas blowby of engine into a kind of flow parameter that is easy to measure, and by the measurement to the latter, obtains the gas blowby parameter of engine.

The utility model is described in further detail below in conjunction with accompanying drawing.

Fig. 1 is a structural representation of the present utility model.

Engine air leak amount pick-up unit is made up of air leak amount sensor and hot-bulb air meter two large divisions.Wherein, the latter is a kind of commercially available prod, and the former is then by sampling pipe 1, side pipe 2, wind speed probe 5, draft tube 7 and formed communicating pipe 8.Sampling pipe 1 is a through hole, and the one end is connected with crankcase, and the other end leads to atmosphere.Its effect is to gather the gas that engine leaks, and in order to make steady air current, its end by crankcase can be made flue.Side pipe 2 is orthogonal with sampling pipe 1, can adopt to be threaded, can adopt alternate manner.Its effect is that a part of dynamic pressure with sampling pipe 1 inner fluid becomes the negative pressure in the side pipe 2.The effect of draft tube 7 is that cleaned air is imported, and it is a blind hole, and sidewall is opened a hole, by communicating with side pipe 2 communicating pipe 8, is connected with therebetween and visits seat 6.Visiting seat 6 is a closed chamber, gas in the draft tube 7 can flow into sampling pipe 1 by it, chamber internal fixation wind speed probe 5, the gas blowby of crankcase is by the flow through sampling pipe 1 of sensor of machine oil filler port, in side pipe 2, form negative pressure, clean air is just flowed through by draft tube 7 and is visited seat 6, and it is 5 measured to be popped one's head in by wind speed.

In order to prevent the influence of extraneous wind, sampling pipe 1 and draft tube 7 configured in parallel, separated by a distance therebetween, be about 10-70mm, and the former air outlet and the latter's air inlet places same plane.

Wind speed probe 5 is encapsulated in the ballotini, in one group of heater coil and a pair of thermoelectric corner are arranged, the hot junction in thermoelectric corner is placed on the center of heater coil, cold junction is welded on the phosphor-copper pillar, when a certain size electric current flows through heater coil, glass bead is heated, temperature raises, and in the still air of visiting seat 6 chambers, reach a stationary value, at this moment produce certain thermoelectrical potential at two ends, thermoelectric corner, the benchmark back-emf in this electromotive force and the metering circuit offsets, and making output signal is zero, at this moment, the ammeter on the hot-bulb air meter 3 is designated as zero.When air flow, the glass bead temperature reduces, and thermoelectrical potential changes thereupon, the thermoelectrical potential of its variation is compared with the benchmark back-emf in the metering circuit, just obtain a difference signal, after the testing circuit of hot-bulb air meter 3 detects, on ammeter, demonstrate the flow parameter of fluid.

Hot-bulb air meter 3 optional EY3-2A types, supporting with it wind speed probe can be by the requirement transformation of the way of the present utility model, the glass bead (including coil and thermoelectric corner etc.) that is about in the former measuring staff pipe takes out and is fixed in the chamber of visiting seat 6, and its corresponding wiring is by the relevant circuit connection on lead 4 and the hot-bulb air meter.

During operation, return to zero, give heat, choose the wind speed gear: the sampling pipe 1 and the engine crankcase oil hole of sensor are connected together, can measure by the instructions requirement of hot-bulb air meter 3.

The utility model can be measured 0.67 liter/min air quantity, the degree of accuracy less than the full scale value of corresponding range ± 2%. By detecting the air leak amount of engine crankcase, can in internal combustion engine running-in, performance mensuration, reliability test, monitor the wearing and tearing between piston, piston ring and cylinder sleeve, also can before the internal combustion engine overhaul, identify cylinder wearing and tearing degree, also can be used as the auxiliary equipment that engine failure is judged; In addition, because tested gas does not directly contact wind speed probe 5, can the measuring instrument of costliness not polluted, therefore, the utility model also can be widely used in the accurate measurement of dirty gas.

Claims

1, a kind of engine air leak amount pick-up unit that comprises wind speed probe 5 and hot-bulb air meter 3, it is characterized in that hot-bulb air meter 3 obtains signal by sensor, sensor is by sampling pipe 1, side pipe 2, visit seat 6, draft tube 7 and communicating pipe 8 are formed, sampling pipe 1 is orthogonal with side pipe 2, draft tube 7 and sampling pipe 1 configured in parallel, the gas outlet of the air intake opening of draft tube 7 and sampling pipe 1 is on same plane, draft tube 7 is joined by communicating pipe 8 and spy seat 6, the latter communicates with side pipe 2 again, wind speed probe 5 is fixed in the chamber of visiting seat 6, and its heater coil is connected with the relevant circuit of hot-bulb air meter 3 by lead 4 with thermoelectric corner.

2, engine air leak amount pick-up unit according to claim 1 is characterized in that the end that sampling pipe 1 communicates with crankcase can make flue.