CN1187580A - Two-Stage Boost Compensation System Device for Diesel Engines - Google Patents

Abstract

A two-stage supercharging compensation system device for a diesel engine, even if there is a momentary high pressure when the vehicle starts or suddenly accelerates, the air-fuel ratio can be maintained by the combined force of two springs, so that the maximum torque can be obtained. Among them, the BCS device includes: the upper part forms an inlet for the high-pressure air compressed by the compressor to flow in, and the inner bottom surface is concentrically formed to form a spring installation groove; a diaphragm arranged in the middle part of the inner part of the case; An actuator that operates the fuel injection pump; a two-stage spring that overlaps in double in the spring groove of the casing, has a set height difference, and supports the diaphragm at the same time by one of them.

Description

Two-Stage Boost Compensation System Device for Diesel Engines

The invention relates to a two-stage boost compensating system (BOOST COMPENSATOR SYSTEM, hereinafter referred to as BCS) device of a diesel engine, which is suitable for turbocharger engines and turbocharged intercooler engines such as diesel engines.

Fig. 3 is a schematic configuration diagram showing a conventional turbocharged intercooler engine. It works like this, that is, when the high-temperature and high-pressure exhaust gas (2) discharged into the exhaust pipe (1b) of the cylinder (1) is used to make the turbine (3) rotate, the turbine (3) A coaxially connected compressor (4) rotates, this compressor (4) sucks in atmospheric air (5) and pressurizes it, injecting it forcibly into the cylinders (1) of the engine through the suction pipe (1a) Here, at this moment, the fuel injection pump (6) and the BCS device (7) are automatically adjusted, and the fuel quantity can be increased or decreased at a lower speed in linkage with the increase of the air quantity.

In an engine with the same displacement, when a large amount of air flows in, a corresponding amount of fuel can flow in, so that compared with early naturally aspirated engines, engine performance with higher output power can be obtained.

In the above description, the air pressure formed by the rotation of the compressor (4) is introduced into the BCS device (7) of the fuel injection pump (6), so that the pressure in the BCS device (7) increases, and the increased pressure acts on the diaphragm. On the (7a) side, the fuel quantity of the fuel injection pump (6) does not change until the preset initial tension of the spring (7b) is overcome.

This is because the turbocharger of the turbocharger engine is in the low-speed region with low speed, and the amount of air sucked by the inertial force of the turbocharger is smaller than that of the naturally aspirated type. It will cause problems such as excessive black smoke, so in order to suppress such problems, the above-mentioned mechanism is adopted to make it work.

Therefore, the BCS device (7) is a device for operating the injection pump (6) in a direction in which the amount of fuel increases according to a preset spring constant characteristic when the performance of the turbocharger is exerted to a certain extent.

However, the BCS device (7) of the prior art uses only one spring (7b) to sense the pressure of the compressor (4) to activate the fuel injection pump (7). The original function of turbocharger (8), but BCS device (7) can not make the function of turbocharger fully bring into play with 1 spring (7b) linear characteristic.

That is, when the vehicle is started or accelerated suddenly, a large amount of air is sucked in instantly by the compressor (4) and supplied to the cylinder (1) and the BCS device (7) respectively, thus high pressure acts on the BCS device (7), One spring (7b) is momentarily compressed by the high pressure of the BCS device (7) to reduce its volume, thereby operating the fuel injection pump (6) and supplying more fuel than the air volume to the cylinder (1) . Therefore, although a very large amount of fuel is supplied compared to the amount of air, substantially as shown in the graph of FIG. 4 , since the torque increases slowly compared with the increase in pressure, high output cannot be obtained.

The present invention is made in order to solve the problems of the above-mentioned prior art, and its purpose is to provide a two-stage BCS device for a diesel engine, which doubles two springs in the BCA device so that the two springs have Set height difference. In this way, even if there is a momentary high pressure when the vehicle is started or accelerated suddenly, the air-fuel ratio can be maintained by the combined force of the two springs, so that the maximum torque can be obtained.

The two-stage BCS device of the diesel engine of the present invention is made in order to achieve the above object. In the turbocharged engine of the diesel engine, the turbocharged engine is composed of the following parts, that is, connected to the exhaust pipe of the cylinder, powered by high temperature and high pressure The exhaust gas drives the rotating turbine; the compressor that is coaxially connected with the turbine, accepts the rotating force and compresses the air and supplies it to the suction pipe of the cylinder; the BCS device that is operated by the compressed air output by the compressor; The BCS device is a fuel injection pump that adjusts the fuel quantity of the cylinder; it is characterized in that: the above-mentioned BCS device is composed of the following parts, that is, an inlet is formed on the upper part so as to flow into the high-pressure air compressed by the compressor, and the inner bottom surface is concentric. A housing that forms a double spring setting groove; a diaphragm that is airtightly arranged in the middle part of the inside of the housing; an actuator that is integrally connected with the middle part of the diaphragm to make the fuel injection pump actuate; overlapped in the double spring groove of the housing to form a double, A two-stage spring that elastically supports the diaphragm with a set height difference between them.

Fig. 1 is a structural diagram of the present invention.

Figure 2 is a graph showing the relationship between air pressure and torque using the present invention.

Fig. 3 is a schematic configuration diagram of a conventional turbocharger engine.

Fig. 4 is a graph showing the relationship between air pressure and fuel quantity developed with a prior BCS device.

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 3 is a configuration diagram showing an outline of a turbocharged engine for a diesel engine. Fig. 3 will be described in combination with Fig. 1. The symbol (1) represents the engine cylinder, which is formed with an air intake pipe (1a) and an exhaust pipe (1b), and the reciprocating movement of the piston (1c) performs suction, compression, Explosion, exhaust and other 4 strokes.

Symbol (3) is a turbine, which is connected to the exhaust pipe (1b), and is rotated by high-temperature, high-pressure exhaust gas (2). Symbol (4) is a compressor, which is coaxially connected with the turbine (3), accepts the turning force and compresses the air (5) and supplies it to the suction pipe (1a) of the cylinder (1). Fig. 1 is the structural diagram showing the 2-stage BCS device (7) of the present invention, and symbol (71) is the casing that inner air chamber (71d) is formed, and the air inflow port that links to each other with the compressor (4) of Fig. 3 is formed on the top (71a), double spring installation grooves (71b) (71c) are formed concentrically on the inner bottom surface.

Symbol (72) is a diaphragm arranged airtightly in the middle part inside the housing (71), and when the high-pressure air pressure flowing into the air chamber (71d) on the upper side from the compressor (4) through the inlet (71a) acts, the diaphragm (72) is bent downwards, and at this time, it is supported by the resultant force of the spring constant by the two-stage spring (74) (75) in stages, so that the actuator (73) is gradually proportional to the air pressure is pressurized.

The symbol (73) is an actuator integrally connected with the middle part of the diaphragm (72), and operates the fuel injection pump (6) to adjust the fuel quantity when the turbine (3) is in a low-speed region.

Symbols (74)(75) are 2-stage springs, they are overlapped to be double-placed in the double-spring setting groove (71b)(71c) of housing (71), there is a height difference of setting, at the same time, one of them is used Elastic support diaphragm (72).

Next, the function of the embodiment of the present invention will be described with reference to FIG. 3 .

When the turbine (3) is rotated by the high-temperature and high-pressure exhaust gas (2) discharged into the exhaust pipe (1b) of the cylinder (1), the compressor (3) coaxially connected with the turbine (3) is 4) Turning, the compressor (4) sucks in the air (5) in the atmosphere and pressurizes it, and then supplies the air forcibly into the cylinder (1) of the engine through the suction pipe (1a).

On the other hand, the pressure of the compressed air formed by the rotation of the compressor (4) is introduced into the two-stage BCS device (7) shown in Fig. 1 of the present invention, so that the pressure in the BCS device (7) rises, and the The pressure acts on the side of the diaphragm (72) and there is no change in the fuel quantity of the fuel injection pump (6) until the set initial tension of the stage 1 spring (74) is overcome.

However, when the vehicle starts or suddenly accelerates, a large amount of air inhaled by the compressor (4) is supplied to the cylinder (1) and the two-stage BCS device (7) in Figure 2 respectively, and the high pressure acts on the BCS device (7) Above, the diaphragm (72) is momentarily compressed by the high-pressure compressed air flowing into the upper air chamber (71d), and once the first-stage spring (74) is compressed to the set interval (X), Diaphragm (72) just contacts with 2 stage springs (75), compresses 2 springs (74) (75) simultaneously.

At this time, the actuator (73) is pressurized, exerting pressure on the fuel injection pump (6) to the extent that it is lowered.

However, the two springs (74) (75) compressed by high-pressure compressed air elastically support the diaphragm (72) with the resultant force of the spring constant, so that the sudden high-pressure air pressure is gradually relieved, so that the actuator (73) The steep decline turned into a gradual decline. Therefore, by actuating the fuel injection pump (6) in proportion to the gradual lowering of the actuator (73), the amount of air supplied by the compressor (4) and the amount of fuel supplied by the fuel injection pump (6) can be adjusted. The air-fuel ratio is maintained at the set value to fully burn in the cylinder (1), so as to obtain the maximum torque.

It can be seen that, as shown in the curve of Figure 2, when the air pressure rises sharply, the first-stage spring (74) is compressed, and a larger amount of fuel is suddenly supplied in proportion to the air volume, and the second-stage spring (75) ) is compressed, and the two springs (74) (75) are compressed at the same time, the resultant force determined by the spring constant slowly supplies the amount of fuel in proportion to the amount of air. Therefore, compared with the torque of the prior art, The torque of the present invention is gradually increased by the rise of the pressure.

When two springs are double-stacked in the BCS device, and they have a set height difference, even if a momentary high pressure is applied when the vehicle is started or suddenly accelerated, the set force can be maintained by the combined force of the two springs. The air-fuel ratio can obtain the maximum torque, so the output power can be effectively increased in the low-speed region of the engine.

Claims (1)

1, a kind of 2 stage pressurizing compensating systems of diesel engine, in the turbosupercharged engine of diesel engine, this turbosupercharged engine is by constituting with the bottom, promptly, be connected with the outlet pipe of cylinder, by the rotating turbine of discharge gas-powered of High Temperature High Pressure; Join coaxially with turbine, accept turning power and be fed to the compressor of the sucking pipe of cylinder after making air compression; The BCS device that moves by the pressurized air of compressor output; Regulate the fuel-injection pump of the fuel quantity of cylinder by the BCS device; It is characterized in that: above-mentioned BCS device is by constituting with the bottom, promptly, form inflow entrance on top so as to flow into the high-pressure air of compressed machine compression, in inner bottom surface, be the shell that the concentric circle ground dual spring of formation is provided with ditch; Be arranged on the barrier film of the intermediate portion of enclosure hermetically; Link to each other, make the actuator of fuel-injection pump action with the barrier film intermediate portion with being integral; In the dual spring ditch of shell, be overlapped into dual, make height difference that setting is arranged between them, flexibly support 2 grades of springs of barrier film by one of them simultaneously.

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