KR20030034356A - Cylinder Oil Injection Nozzle and Cylinder lubrication system for marine diesel Engine - Google Patents

Abstract

PURPOSE: An injection nozzle and a supplying system for lubricating oil of a large ship is provided to reduce the abrasion degree of a cylinder liner and minimize the lubricating oil supplying amount by forming a uniform lubricating oil film by injecting the liquid of lubricating oil to a wall of a cylinder in a high speed. CONSTITUTION: A lubricating oil injecting nozzle(100) for a large ship is composed of two orifice pipes(131) injecting lubricating oil to a tip of the nozzle(130) and each pipe putting an injection angle of an acute angle upward. A lubricating oil supplying system is installed with the injection nozzle along the circumference of a cylinder liner at regular intervals and provided with a cut receded angle at a commissure of the cylinder liner and the nozzle tip in a direction of the injection angle of lubricating oil.

Description

Cylinder Oil Injection Nozzle and Cylinder lubrication system for marine diesel engine}

The present invention relates to an injection nozzle and a lubricating oil supply system designed to uniformly form an oil film between a cylinder liner and a piston ring in a large marine engine.

In large marine engines, it is necessary to supply lubricating oil to form a constant oil film between the cylinder and the piston ring in order to reduce wear due to solid friction between the cylinder and the piston. The lubricating oil supply method currently used in large marine engines is a system for directly injecting lubricating oil by a lubricating pump between the piston ring and the cylinder liner, or a differential pressure system injected by the pressure difference between the pressure in the cylinder and the lubricating oil system.

Figure 1 shows a conventional lubricating oil supply system.

The prior art is provided along the circumferential surface of the cylinder liner 2 in a constant form such as a spiral type by digging the lubricant supply groove 3 on the wall surface of the liner 2 in the cylinder block, as shown in FIG. The lubricating oil supplied through the nozzle on the vertex (4), the lubricating oil is supplied in the vertical reciprocating motion of the piston (1).

The system is a pump with high viscosity such as grease, a semi-solid lubricant used in large internal combustion engines, which is difficult to supply to the friction surface due to its slow diffusion rate, and changes according to the change of engine load and rotational speed. Depending on the load, it supplies a five-step flow rate that is increased for a certain time set when the load rises above the preset value, but it is supplied at low pressure by a simple check valve. A certain amount of cylinder oil should always be lubricated at the top and bottom. Moreover, in order to reduce the amount of wear of the cylinder, it is necessary to inject a long injection time of the lubricating oil, so that excessive lubricating oil is consumed more than necessary. It is reported that the cost of excessive consumption of lubricating oil reaches the total cylinder safety maintenance cost, and as the ship engine is enlarged, excessive consumption of lubricating oil is more serious, and it is urgent to develop an appropriate lubricating oil supply system. .

In order to solve the above problems, the present invention provides a spray nozzle capable of forming a uniform film of lubricant by spraying a liquid column of the lubricating oil at high speed and a system for disposing the spray nozzle, thereby reducing the amount of wear of the cylinder liner and reducing the amount of lubricant The purpose is to minimize the supply of water.

Figure 1 is a schematic diagram showing a conventional large lubrication system for ships

Figure 2 (a) (b) (c) is a detailed cross-sectional view showing a lubricant injection nozzle according to the present invention

Figure 3 (a) is a cross-sectional view of the lubricant supply system according to the present invention, (b) an enlarged cross-sectional view of the lubricant supply system according to the present invention.

(Detailed Description of the Drawings)

1: piston

2: cylinder liner

3: lubricant supply groove

4: vertex

100 : lubricant injection nozzle

110: barrel

120: needle

130: tips

131: orifice articles

140: lubricant supply pipe

150: spring

210: liner

211: liner bond surface

212: infeed

220: cylinder block

230: lubricant

Hereinafter, the present invention will be described in detail with reference to the drawings.

Each figure of FIG. 2 shows a lubricating oil spray nozzle according to the invention.

Fig. 2A is a schematic diagram showing the configuration of the injection nozzle according to the present invention, which explains the simple configuration of the injection nozzle and the function of the injection nozzle in the lubrication flow supply system.

The lubricating oil injection nozzle 100 is surrounded by a barrel 110, a needle 120 having a spring 150 therein, a tip 130 composed of two orifice tubes 131, and a lubricating oil inlet pipe for supplying lubricating oil. 140.

The lubricating oil injection nozzle supplies lubricating oil in such a way that the lubricating oil is injected into the cylinder when the hydraulic pressure in the pipe is higher than the needle opening pressure by the lubrication pump while the needle is normally closed by the elastic force of the compression spring 150. .

The reason for choosing this approach is that the structure is simpler than the electrohydraulic, which normally uses solenoids to control the opening and closing, and can reduce the failure rate of the entire lubrication system as well as the maintenance and repair is relatively easy.

The flow rate supplied by the nozzle varies with the output of each engine to be applied, and in general, the average injection amount varies in relation to the shape change of the nozzle and the oil pump characteristics. In addition, the flow rate characteristic is expressed as the amount of lubricating oil injected per camshaft rotation angle of the fuel pump, which is one of the factors to maximize the lubrication efficiency.

The constant of the compression spring 150 has a great influence on the nozzle response and flow rate characteristics. If the spring 150 force is too large for the hydraulic pressure, not only the injection time and rise time will be delayed, but also the injection time is relatively small for the same injection amount, so that smooth lubrication cannot be expected. Due to the relatively long period, smooth lubrication cannot be expected. .

In general, the constant of the spring 150 can obtain the initial tension of the spring as shown in Equation 1 by substituting the stationary condition in the equilibrium relationship of the force acting on the needle 120 in the stationary state. Where Po and Pс represent the starting pressure and the combustion chamber pressure, respectively.

On the other hand, Figure 2 (b) (c) shows a front view and a side view of the tip according to the present invention, respectively.

The injection nozzle is equipped with a needle valve that opens and closes the lubrication jet hole, so that the hole is opened only when necessary, and the nozzle, pintle nozzle and sto are formed according to the tip (TIP) shape of the tip of the needle valve. Separated by.

The present invention can be said to be a hole nozzle of the division, the tip 130 portion of the nozzle is two orifices (orifice) to form an oil film on the cylinder wall surface within a short time, the axial spacing (b) and radius It is formed in the interval (c), respectively, and the closer the axial spacing and the radial spacing to within 5mm, respectively.

The tip 130 of the nozzle is convex, and two orifice tube 131 is formed. In order to maintain the injection angle of the lubricating flow in the convex portion of the tip to have an injection angle a °, a '°, wherein the injection angle a °, a' ° is preferably about 2 ° ~ 6 °.

In addition, the diameter of the orifice tube 131 of the nozzle may be expressed by an equation including an oil transfer pressure, a combustion chamber pressure, a needle shape and a head of the pump, as shown in Equation 2. (The head is the needle lift of the nozzle, where X is the needle lift, kx is the spring constant, D is the maximum diameter of the needle, d is the seat contact direct, Q is the volumetric flow rate, μ is the flow coefficient, A is the orifice cross-sectional area, Po is the opening pressure, θ is the needle cone angle, and Pc is the combustion chamber pressure.

The lubricating oil supplied through the lubricating oil injection pipe 140 is sprayed onto the liner 210 surface through the orifice positive pipe 131 of the tip to form an oil film.

Since forming an oil film in the cylinder can greatly reduce the oil consumption compared to the conventional method, it is necessary to effectively form an appropriate amount of the oil film in the cylinder. The film thickness is a function of the average dosage and the gap length and angle. In general, the minimum oil film thickness required for smooth lubrication is 1.25㎛, but since the frictional force increases as the engine speed is low, the oil film thickness that is formed according to the engine speed should be thickened.

The lubricant supply system according to the present invention will be described with reference to FIG. 3.

Figure 3 (a) shows the arrangement of the injection nozzle and the lubricant injection in the lubricant supply system according to the present invention.

Injection nozzles for supplying lubrication are arranged at regular intervals along the circumference of the liner 210 inside the cylinder. At this time, the number and spacing of the injection nozzles are determined by the size of the engine, that is, the cylinder diameter.

The force that can proceed until the particles of the injected lubricant form a lubrication membrane is called penetration or the reach of the lubricant particles. The factors constituting the penetration are lubricant viscosity, particle size, nozzle diameter, and spraying. There are angle, injection pressure and spring constant.

The reach of the lubricating oil ejected from the two orifice tube 131 of each nozzle is as follows. That is, the lubricating oil ejected from the orifice tube of one of the orifice tubes 131 located on one side of the nozzle tip is injected to the first nozzle to the right side of the nozzle, and the lubricating oil ejected from the other orifice of the tube is the right side of the nozzle. Sprayed between the first and second nozzles.

Thereby, even if one injection nozzle mounted to the cylinder liner fails and a state which cannot inject lubricating oil can form a lubricating film.

Fig. 3B is an enlarged view showing the joining surface between the tip and the cylinder liner in the arrangement of the injection nozzle.

The tip 130 of the injection nozzle is mounted by cutting in the spraying direction of the lubricant 230 from the liner 210 and the liner bonding surface 211. To this end, the liner bonding surface 211 is provided with an incision 212 of an appropriate angle so that the lubrication flow from the tip of the injection nozzle can be injected in the injection angle direction. The cutout portion is formed to have an inclination angle d.

Accordingly, the lubricant injected from the orifice tube 131 is sprayed onto the liner surface, and the lubricant 230 injected from the orifice tube 131 forms an oil film without colliding with the wall surface of the cylinder lining 210.

The present invention forms a uniform oil film along the wall by hitting the optimum amount of lubricating oil against the wall of the cylinder at high speed, thereby greatly reducing the consumption of lubricating oil and improving the wear characteristics of the cylinder.

In the lubrication system that is currently commercialized, the consumption flow rate is 1.2g / HP.h, but in the lubricating oil supply system according to the present invention, the consumption can be reduced by about 30% to 50%. Large container ships that are being consumed can save about 200 million won per year per chuck.

Claims (2)

In a large ship lubricating oil injection nozzle; Lubricating oil injection nozzle, characterized in that to form two orifice pipes for injecting lubricating oil on one side of the nozzle tip, each of the pipes to the upward angle as shown in Fig. 2 (b). Arranging the injection nozzle of claim 1 to construct a lubricating oil supply system, wherein the nozzles are mounted at regular intervals along the circumference of the cylinder liner, and a cutting angle in the direction of the lubricating oil spraying angle is formed on the cylinder liner and the nozzle tip joint surface. Lubricating oil supply system.