KR100420588B1 - Cylinder Oil Injection Nozzle and Cylinder lubrication system for marine diesel Engine - Google Patents

Abstract

The present invention relates to a lubricating oil 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.

The present invention provides a spray nozzle which can spray a liquid column of lubricating oil to the cylinder wall surface at a high speed to form a film of uniform lubricating oil, and a system for disposing the spray nozzle, thereby reducing the amount of wear of the cylinder liner and minimizing the amount of lubricating oil supplied thereto. There is a purpose.

Description

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

The present invention relates to a lubricating oil 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 a piston ring and a cylinder liner, or a differential pressure system injected by a pressure difference between a pressure in a cylinder and a lubricating oil supply system.

Figure 1 shows a conventional lubricating oil supply system.

The prior art, as shown in Figure 1, the lubricating oil supply groove (3) in the wall surface of the liner (2) in the cylinder block, but formed along the circumferential surface of the cylinder liner (2) in a constant shape, such as screw, The supply is supplied through the nozzle on the vertex 4 of the supply groove 3, the lubricating oil is used to supply the lubricating oil in the up and down movement of the piston (1).

However, in the case of highly viscous lubricants, such as grease, which is a semi-solid lubricant used in large internal combustion engines, the system has a low diffusion rate and is difficult to supply to the friction surface as a whole. And it is controlled according to the change of rotational speed, and depending on the load, if the load exceeds the preset value in the process of raising the load, the flow rate is increased in 5 stages for a predetermined time, but it is supplied at low pressure by a simple check valve. In order to ensure smooth lubrication with longer injection time, a certain amount of cylinder oil must be continuously supplied at the upper and lower parts of the piston regardless of the engine operating condition.To reduce the amount of wear of the cylinder, Too much injection time, so much more than necessary Lubricant is consumed. It is reported that the cost of excessive consumption of lubricating oil reaches the total cylinder safety maintenance cost, and as the ship engine becomes larger, 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 reduces the amount of wear of the cylinder liner by providing a spray nozzle and a system for dispensing the spray nozzle and the spray nozzle that can form a film of a uniform lubricant by spraying the liquid column of the lubricant to the cylinder wall at high speed The purpose is to minimize the amount of lubricant supplied.

1 is a schematic diagram showing a conventional large lubricant supply 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 lubricating oil supply system.

The lubricating oil injection nozzle 100 is installed in the barrel 110, the spring 120 and the needle 120 to move forward / backward by the spring, the nozzle tip 130 is disposed at the tip of the barrel 110, the barrel A hydraulic forming lubricant injection tube 140 is formed on the 110 to move the needle 120 forward and backward, and two orifice tube 131 for injecting lubricant is formed on one side of the nozzle tip 130. On the other hand, each orifice tube is formed to have a different acute angle with respect to the vertical line of the barrel axis and to be spaced apart in the barrel axial direction.

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 it is relatively easy to maintain and maintain, as well as to reduce the failure rate of the entire lubrication system.

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. This is relatively long and smooth lubrication cannot be expected.

In general, the force of the compression spring 150 can be obtained by initializing the spring as shown in Equation 1 by substituting the static condition in the equilibrium relationship of the force acting on the needle 120 in the stopped state.

In the above Equation 1, Po and Pс represent the starting pressure and the combustion chamber pressure, respectively, D represents the maximum diameter of the needle, d represents the seat contact diameter of the needle.

On the other hand, (b) (c) of FIG. 2 shows the front view and the side view of the tip by this invention, respectively.

The injection nozzle is equipped with a needle valve that opens and closes the lubricating oil ejection hole so that the hole is opened only when necessary. According to the shape of the tip (TIP), which is the end of the needle valve, the nozzle has a hole nozzle, a pintle nozzle, and a sto Are distinguished.

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. The convex portion of the tip has a spray angle a °, a '° so that the spray angle of the lubricating oil can be maintained upward, wherein the spray 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. Here, the head is the needle lift of the nozzle. In Equation 2, X is the needle lift, k _s X is the spring constant, D is the maximum diameter of the needle, d is the seat contact diameter, Q is the volumetric flow rate, μ is the flow coefficient, A is the orifice cross-sectional area, Po is Transformation pressure, θ is the needle cone angle, 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 lubricating oil 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.

As a result, even if a failure occurs in one injection nozzle mounted on the cylinder liner, the lubricating film can be formed even in a state in which the lubricating oil cannot be injected.

FIG. 3B is a partially enlarged view showing the joining surface of the tip and the cylinder liner part in disposing the injection nozzle. FIG.

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 joint surface 211. To this end, the liner bonding surface 211 is provided with a cutout portion 212 of an appropriate angle so that the lubricant oil can be injected in the direction of the injection angle at the tip of the injection nozzle. 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 is to hit the optimum amount of lubricant on the wall of the cylinder at high speed to form a uniform oil film along the wall, greatly reducing the consumption of lubricant and improve the wear characteristics of the cylinder.

In the case of the lubrication device 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%, consuming 14 drums of lubricant per day. In the case of large container ships, the cost per year can be reduced by about 200 million won per chuck.

Claims (2)

In a large ship lubricating oil injection nozzle; A spring is installed inside the barrel and a needle forward / reversed by the spring, a nozzle tip is disposed at the tip of the barrel, and a barrel is formed with a hydraulic oil lubricating oil injection tube for forward / backward of the needle. Two orifice tubes are formed on one side of the tip to inject lubricant, and each orifice tube has a different acute angle with respect to the vertical line of the barrel axis, and is placed upwardly to be spaced apart in the barrel axial direction. Lubricant injection nozzles that allow the lubricant from the orifice tube to be sprayed in different locations. In the arrangement of the injection nozzle of claim 1 to configure the lubricant supply system, the nozzle is mounted at regular intervals along the circumference of the cylinder liner, characterized in that the cutting angle in the lubricating oil injection angle direction on the cylinder liner and the nozzle tip joint surface Lubricant supply system.