RU2185519C1 - Engine emergency shutdown mechanism - Google Patents

Abstract

FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: invention relates to control systems of internal combustion engines. Proposed emergency shutdown mechanism has housing, head coupled with lever of high-pressure fuel injection pump drive, lock, balls, spring and electromagnet. Fuel system includes additionally a device with housing and spring-loaded spool coupled hydraulically with oil and fuel systems and coupled mechanically with electromagnetic which is electrically coupled with tank electric circuit through switch. EFFECT: simplified design of device, improved reliability, increased service life and efficiency of engine. 2 dwg

Description

 The invention relates to the field of armored vehicles, in particular to the power plants of tanks.

 Known analogues provide engine shutdown only when the collective protection system (RMS) is triggered or when the "Emergency engine shutdown" button is pressed.

 Meanwhile, the known engine shutdown mechanisms (MOD) do not respond to other disturbances, in particular, to a drop in oil pressure in the oil system below a limit value, which usually leads to engine failure. Thus, to ensure engine shutdown in the event of a decrease in oil pressure, the development of a special automatic device is necessary.

 From the studied analogues, the engine shutdown mechanism of the T-72 tank was selected as a prototype (see T-72 tank. Technical description and operating instructions. Book two. M.: Military Publishing House, 1975, pp. 99-101), consisting of a hull, the tip associated with the lever of the high pressure fuel pump, lock, balls, springs and electromagnet.

 The analysis of military operation of BTT armored vehicles facilities shows that one of the main reasons for engine failure is its operation without oil due to the destruction of the rubber plug (UTD-20) or the drive of the oil pump (B-84-1), oil leak, etc. .

 To increase engine reliability in the process of military operation, industrial enterprises systematically carry out the identification and investigation of engine defects, develop measures to eliminate them and introduce these measures into mass production. So, on the T-72 engine, the oil system is equipped with a limit pressure switch, consisting of a sensor mounted on the eighth main bearing of the crankshaft and a signal lamp "Pressure DV" on the remote control of the driver. When the oil pressure on the eighth support drops below 0.04 MPa, the remote control lamp lights up, signaling the need to stop the engine. All this helps to increase the reliability and durability of the T-72 engine.

 However, the use of a device that provides automatic engine shutdown in an emergency (oil pressure drop in the lubrication system) during operation can be more effective, as it helps prevent the cause of failure.

 Therefore, at present, there is an urgent need to develop and implement additional automatic devices that increase the reliability of the engine during operation of the BTT.

 The objective of this technical solution is to develop an emergency engine shutdown mechanism if the oil pressure in the oil system decreases below the permissible value by installing an additional device in the fuel system having a housing and a spring-loaded spool hydraulically connected to the oil and fuel systems, and mechanically to an electromagnet, moreover the latter has an electrical connection with the onboard network of the tank through a switch.

 The proposed device is shown in figure 1. It consists of a housing 1, a spool 2 and a spring 3, as well as (see FIG. 2) an electromagnet 5 and a switch 6.

 In FIG. 2 is a layout diagram of an emergency engine stop device.

 An emergency stop device for the engine 4 (see Fig. 2) is installed between the fuel fine filter 3 and the high-pressure fuel pump 2, which ensures a quick stop of the engine 1 in the event of a decrease in oil pressure in the oil system by stopping the supply of fuel to the engine.

 The spool of the emergency stop device is mechanically connected by an electromagnet 5, which has an electrical connection with the on-board network through a switch 6.

 The operation of the proposed device is as follows. Before starting the engine after a long standstill, the fuel system is pumped by the BTsN-1 pump or the RNM-1 manual fuel priming pump, for which the handle of the fuel distribution valve is set to the "Tanks are on" position and the toggle switch 6 is turned on. At the same time, the air release valve button must be recessed. With the inclusion of the toggle switch 6, the voltage of the on-board network is supplied to the winding of the electromagnet 5. As a result, the electromagnet arm, compressing the spring 3 (see Fig. 1), moves the spool 2 and connects the fuel channel "a" in the spool with the pipeline, providing fuel from the thin filter cleaning to the high pressure pump.

 After removing air from the fuel system and creating an oil pressure in the oil system by the MZN-2 pump, the driver starts the engine and turns off the toggle switch 6, disconnecting the electromagnet winding. Moreover, after starting the engine and putting it to the minimum stable idle speed by the manual feed handle, the spool 2 under the influence of oil pressure (above 0.1 MPA) remains in the same position, compressing the spring 3 and providing fuel to the injection pump.

When the engine is running at the operating speed of the crankshaft (n = 1600-1900 min ^-1 ), the oil pressure in the oil system is 0.5-1.0 MPa, which reliably holds the spool 2 in the position shown in FIG. 1. At the same time, channel "a" of spool 2 remains connected to the fuel pipeline and connects the fine filter to the high-pressure fuel pump.

 In the case of a decrease in oil pressure in the oil system for various reasons below 0.2 MPa, the spool 2 moves under the action of a spring 3, blocking the fuel pipe with its body. The fuel supply stops and the engine stops.

 After identifying the cause of the decrease in oil pressure and eliminating the malfunction, the engine starts. To do this, you must turn on the switch 6, pump the fuel system, as discussed above, start the engine and turn off the switch 6.

 The proposed device was experimentally tested at the Combined Arms Academy. The results of the experiment confirmed the feasibility of its use in the power plants of tanks and infantry fighting vehicles to prevent the failure of engines with a decrease in oil pressure during operation.

 The simplicity of the proposed device allows its implementation without special economic costs both during the modernization of BTT facilities, and when creating new power plants.

 The adjustment of the spring 3 (see figure 1) (0.2 MPa or 0.04 MPa) depends on the connection point of the emergency engine stop mechanism in the oil system.

Claims (1)

 The emergency stop mechanism of an internal combustion engine, consisting of a housing, a tip connected to a lever of a high pressure fuel pump drive, a lock, balls, a spring and an electromagnet, characterized in that the fuel system further includes a device having a housing and a spring-loaded spool hydraulically connected to oil and fuel systems, and mechanically - with an electromagnet, the latter having electrical communication with the on-board network of the tank through a switch.

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