WO2008051108A1

WO2008051108A1 - Cylinder pressure test device

Info

Publication number: WO2008051108A1
Application number: PCT/RU2007/000064
Authority: WO
Original assignee: Isaev, Vladimir Afanacevich
Priority date: 2006-10-27
Filing date: 2007-02-02
Publication date: 2008-05-02
Also published as: RU2006137959A

Abstract

The inventive device comprises electropneumatic pressure sensors, which are arranged in the cylinder of an engine and are connected with a pressure gauge and a valve by means of a common main, and a pressure recorder, wherein each electropneumatic sensor comprises a body provided with a nipple and an electric contact connectable to the recorder, a reversing disc valve, which is arranged in the body between a measurable pressure cavity and a comparable pressure cavity communicating with the common main, and a coiled spring, one end of which is placed on a pin insulated from the body and connected to the electric contact, whilst the other end of which is placed on the centring element of the disc valve, which is arranged with a space in a ring groove, embodied in the internal cylindrical surface of the body, in such a way that top and lower seats are formed. The inventive device is characterised in that a reversible element is embodied in the form of a flat disc, the side surface of which is shaped in the form of a truncated cone oriented towards the spring.

Description

Device for monitoring cylinder pressure

Technical field

The invention relates to devices for monitoring the condition of internal combustion engines. This invention can be successfully used to control cylinder pressure both during engine start-up and during its operation.

State of the art

It is known that before starting the engine after a long standstill, it is necessary to crank the engine and remove from the cylinders the liquid that is there for any reason: water, fuel, oil. If this is not done, then a water hammer may occur.

On engines of medium and high power in the cylinders there are special purge channels with indicator valves, through which this liquid is removed.

The operation of opening and closing valves, carried out manually, is time-consuming, especially for multi-cylinder engines (16-18 cylinders), so motorists in every possible way avoid it, which leads to a great risk of getting a water hammer.

Also known are devices and systems for monitoring cylinder pressure of an engine during its operation, for example, portable devices from Maygak, Kistler, or stationary systems from Autronika and ABB Tsildet.

The most perfect of them is the system of the company Autronika (prospectus of the company Autopisa AS MΙP-Calculator NK-100; N-7005 Тpopheim. Norwow. 1997). This system provides information about both peak pressures - combustion, compression, and intermediate ones.

In addition, it informs about the average indicator pressure and the operation of the fuel injection. However, this system does not take any part in operations when starting the engine. At the same time, this system has a very complex design, in which several types of sensors are involved,

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including analog. The process of setting up the system - zero adjustment, is very complicated. The presence of electronic elements that are installed in the engine room close to sensors reduces its operational reliability. In addition, the system has a high cost. As a result of all this, the system is not widely used.

A device is also known for monitoring an internal combustion engine (SU 1245901 A1, MKI G 01 L 23/00). The device contains electro-pneumatic pressure sensors with flapper valves installed in the engine cylinders, and combined by a common line with a pressure gauge and bleed valve, as well as a pressure value recorder.

The disadvantage of this device is that the valve design does not provide the device with reliable registration of cylinder pressure in individual engine operating modes.

Disclosure of invention

The present invention was based on the task of designing a cylinder pressure monitoring device in which the pressure sensor was designed in such a way as to ensure reliable continuous monitoring of cylinder pressure in all engine operating modes.

The problem is solved in that in a device for monitoring cylinder pressure containing electro-pneumatic pressure sensors installed in the engine cylinders and combined by a common line with a manometer and valve, as well as a pressure recorder, each of the electro-pneumatic sensors contains a housing with a fitting and an electrical contact connected to a recorder installed in the housing, a flapper disk valve located between the cavity of the measured pressure communicated through the inlet channel of the fitting with the cavity purge channel engine cylinder, and the cavity pressure being compared, com- device aboard a common manifold, and a coil spring, different

SUBSTITUTE SHEET (RULE 26) placed at one end on a pin isolated from the body, connected to an electrical contact, and the other on the centering element of the disk valve mounted with a gap in the annular groove made on the inner cylindrical surface of the body with the formation of the upper and lower seats, new is that the cross over element is made in the form of a flat disk, the side surface of which has the form of a truncated cone, facing the spring side. Thanks to this combination of design features, it became possible to provide timely opening and closing of the measured and compared pressures during operation of the device and centering of the valve relative to the housing at all engine operating modes, which ensures the solution of the problem posed.

The essence of the present invention is explained in more detail below with a detailed example of its implementation, with reference to the accompanying drawings, in which: The list of figures in the drawings of figure 1 schematically depicts the construction of a sensor for monitoring cylinder pressure mounted on the engine, in accordance with the claimed invention, a longitudinal section; 2 is a general diagram of the inventive device for monitoring cylinder pressure.

The device comprises pressure sensors 1 (FIG. 1) of pressure installed in each cylinder 2 of the engine. Each pressure sensor 1 contains a housing 3, cap 4, valve 5, spring 6, pin 7, electrical contact - terminal 8 and nipple 9. Terminal 8 is pressed onto the shank of pin 7. Pin 7 with terminal 8 is isolated from cap 4 by sleeve 10.

The sensor housing 3 with its fitting 11 is screwed into the socket 12 of the head 13 of the cylinder 2 of the engine, into which the indicator valve was previously screwed. In this case, the camera 14

SUBSTITUTE SHEET (RULE 26) cylinder 2 of the engine through the purge channel 15 is connected to the cavity 16 of the compared pressure.

The cavity 17 of the compared pressure of the sensor 1 through the nipple 9 is connected to a common highway 19 (figure 2). The cavity 17 (FIG. 1) of the measured pressure and the cavity 18 of the compared pressure are separated from each other by the valve 5.

The valve 5 of the sensor 1, depending on the operating mode of the engine, can be stationary on its lower seat 18 of the cavity of the compared pressure, or alternately tear off from it, or be transferred from the lower seat 18 to the upper saddle 19 and vice versa. Through the spring 6, the valve 5 is in constant contact with the pin 7 and the terminal 8. The valve 5 relative to the housing 3 is centered using a flat seat having a lateral surface in the form of a truncated cone, facing the spring 6. The taper angle is in the range of 10 - 20 degrees. At other taper angles, an exact fit of the crossover valve is not ensured, as a result of which accurate measurement of cylinder pressure in individual engine operating modes is not ensured. The common highway 20 (FIG. 2) is constantly connected to the pressure gauge 21 of the pressure recorder 22, and through the valve 23 it can be connected to the atmosphere. To the pressure recorder 23 are also connected terminals 8 (FIG. 1) of the pressure sensors 1 and a power supply 24 (FIG. 2). On the housing of the recorder 22 is a display panel 25.

The device operates as follows. Before starting the engine, close the bleed valve 23 and begin cranking the crankshaft with a starting device.

The air compressed in the chamber 14 (fir. 1) through the channel 15 will enter the cavity 17 of the measured pressure and, overcoming the force of the spring 6, will lift the valve 5. In this case, the excess air through the formed annular gap will enter the cavity 16, and from there through the nipple 9 ( figure 1) to the highway

SUBSTITUTE SHEET (RULE 26) 20 (FIG. 2). The registrar 22 at this moment will record a rupture of a single-wire electrical circuit with a valve 5 (figure 1).

Compressed air from the cylinders will enter the system through sensors and briefly block the access of gases by means of a toggle valve. As soon as the system is filled with cylinder pressure and the pressure gauge indicates steady pressure, regular flashes on the display panel 22 will stop. The indication (flashes) of only those cylinders in which the pressure is greatest will remain, and the difference between the flashes will be no more than 1 - 2 kg / cm.

In order to measure the cylinder pressure, it is enough to open the bleed valve 23 and observing the indication of the control pressure gauge to determine the maximum cylinder pressure for each individual cylinder. It is allowed to open the bleed valve from zero to completely purge the system, but the opening time of the system should not exceed one minute. After measuring the cylinder pressure, the pressure gauge will again return to its original position. If you turn off the fuel supply to the cylinder, you can also determine the compression ratio in the cylinder.

Industrial applicability

The inventive device has a simple design and manufacturable. The device is reliable in operation and does not require highly qualified service. It was made several prototypes of the claimed device, which are currently in trial operation and confirm their reliability.

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Claims

Claim

A device for monitoring cylinder pressure, containing electro-pneumatic pressure sensors installed in the engine cylinders and combined by a common line with a manometer and valve, as well as a pressure recorder, each of the electro-pneumatic sensors contains a housing with a fitting and an electrical contact connected to the recorder mounted in the housing the cross over disk valve located between the measured pressure cavity and the compared pressure cavity communicated with the common line, and a cylindrical inu, placed at one end on a pin isolated from the body connected to an electrical contact, and the other on the centering element of the disk valve installed with a gap in the annular groove made on the inner cylindrical surface of the body with the formation of the upper and lower seats, about t and moreover, the flip element is made in the form of a flat disk (5), the lateral surface of which has the form of a truncated cone facing the spring.

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