JPH04318276A - Lubricating device for piston member of fuel injection pump - Google Patents

Abstract

PURPOSE: To prevent reaction between lubricant and fuel from forming adhesive lacquer and carbon deposit, by improving lubrication between a cylinder element and a piston member of a fuel injection pump. CONSTITUTION: A lubrication arrangement for a piston member 2 is arranged to be reciprocatingly movable in a cylinder element 1 of an injection pump for fuel or the like pressure medium. Lubricant is supplied under pressure into a lubrication groove 5 arranged in the cylinder element 1 and encircling the piston member 2. The flow-through of the lubricant is improved by providing the cylinder element 1 with at least one channel 6 extending in the longitudinal direction of the cylinder element 1, which channel 6 is connected with the lubrication groove 5 for leading lubricant continuously into another position on the mantle surface of the piston member 2 at a distance from the lubrication groove 5 further to be recovered and for possible recirculation.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION The present invention relates to a device according to the preamble of claim 1 for lubricating a piston member of an injection pump of a pressure medium, such as fuel.

0002

BACKGROUND OF THE INVENTION The supply of fuel to the cylinders of internal combustion engines by injection pumps takes place under high pressure. For this reason,
The gap between the sliding surfaces of the cylinder element and the piston member of the pump is very tight, only a few thousandths of a millimeter, so that almost no fuel can leak through the gap into the interior of the pump. Generally, the purpose of the lubrication system for the piston member of an injection pump, in addition to providing lubrication of the piston member, is to tighten the gap and thus prevent fuel leakage in that area. Additionally, the lubrication provides cooling, protection, and cleaning.

In known lubrication systems, lubricating oil is introduced into the gap using pressure. However, due to the narrowness of the gap, the oil flow is slow even when the oil delivery pressure is increased. Furthermore, the lubricating oil is sufficiently warmed in the narrow gap and thus exceeds the desired value of about 110°C to 115°C for mineral oil, which makes it sufficiently warm, especially when heavy oil is used as fuel in large diesel engines. Lubricating oil that is warmed up reacts more easily with the fuel to form sticky lacquer and carbon deposits, which make it more difficult for the piston member to move within the cylinder and reduce the lubricating oil delivery. Even ducts can become completely obstructed. It should be recognized that the large diesel engine referred to here is an engine that can be applied as a main propulsion engine or auxiliary engine for ships in diesel heating power plants and the like.

0004

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new and improved lubrication system for piston members of injection pumps, which largely eliminates the drawbacks present in known systems, especially those associated with large diesel engines using heavy oil as fuel. It is to be.

[0005] The object of the invention is achieved in the embodiments specified in claim 1 and the dependent claims. With the lubrication system according to the invention, the flow of the lubricating oil may be made more efficient, so that the temperature of the lubricating oil remains lower and impurities are removed more effectively. Improved effectiveness may be obtained with lower pressures than in known systems.

[0006] The flow of lubricating oil may be made even more effective, so that the channels extending in the longitudinal direction of the cylinder element are arranged at least on opposite sides of the cylinder element with respect to the position of supplying the lubricating oil.

An advantageous solution from the point of view of lubrication and cleaning is that the cylinder element has a separate lubrication channel surrounding the piston member and arranged at a predetermined distance from said lubricating oil, said lubrication channel is obtained when the piston member is connected to said longitudinally extending channel and arranged in relation to the jacket surface of the piston member so as to effect lubrication. The lubrication channel may be coupled to the jacket surface of the piston member via one or several nozzle orifices or the like to achieve splash lubrication in the lower portion of the piston.

Furthermore, the substantial gap is such that the lubricating oil is freely channeled from the lubricating channel along the jacket surface of the piston member into a collecting sump or corresponding space in which the lubricating oil to be collected is collected. It may extend from the oil recovery space to the location of the lubrication channel and be located between the cylinder element and the piston member.

The present invention will now be described in more detail with reference to the accompanying drawings.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the figure, reference numeral 1 designates a cylinder element of a fuel injection pump which surrounds a movable piston member 2 in reciprocating motion. Although the present invention does not concern the actual delivery of fuel by an injection pump, this may be carried out in a known manner by making use of such structural solutions as are known. Therefore, these structures are not shown in detail in the drawings and will not be described herein.

As a result of the normal operation of the injection pump, the fuel flows away from the fuel injection chamber into the inner part of the pump due to the high pressure, ie downwards in FIG. It tends to flow into the gap 3 between them. When heavy oil is used as fuel, especially in large diesel engines, the mixture of fuel and oil used to lubricate the gap 3 tends to form carbon deposits or become sticky lacquer due to high temperatures. There is. According to the invention, prevention of this phenomenon is achieved by making the flow of the lubricating oil effective, so that the temperature of the oil can be lowered and the impurities that give rise to carbon deposits can be removed. be.

According to FIG. 1, lubricating oil is applied to the piston member 2.
along the channel 4 into a lubricating groove 5 which is arranged in the cylinder element 1 surrounding the lubrication groove. The lubricating oil is conducted from the lubricating groove 5 along a channel 6 extending in the longitudinal direction of the cylinder element into a lubricating channel 7 which likewise surrounds the piston member 2 and which extends in the direction remote from the pressure chamber of the pump. is arranged at a predetermined distance from the lubricating groove 5. Several nozzle orifices 8 are provided around the lubrication channel 7 , through which the channel 7 is connected to the jacket surface of the piston member 2 . Due to the nozzle orifice 8, the cross-sectional area of the orifice 8 is better limited compared to the channel 7, and the jacket surface is under splash lubrication, thereby correspondingly more effective lubricating oil. Spraying makes lubrication and forward removal of impurities effective. At the same time, the nozzle orifice 8 allows the lubricating oil to fully act on the jacket surface of the piston member and serves to limit excessive flow of the lubricating oil through the lubricating groove 5 .

[0013] After the nozzle orifice 8, the lubricating oil is conducted through a gap 9 into a space 10 inside the pump, from which it may be recovered and, after purification, recycled.

In FIG. 2, the circulation of lubricating oil according to the embodiment of FIG. 1 is illustrated by showing only the lubricating oil channels and flows.

In principle, the nozzle orifice 8 may be formed in different ways, but a circular hole is of a rather optimal shape in order to remove even large particles of impurities. For example, instead of a hole, one or several slots surrounding the piston member can be implemented as well, but the width of the slot for a flow rate corresponding to the flow rate through a nozzle orifice with a particular diameter may be significantly smaller than the diameter, thereby allowing the slot to be penetrated by impurity particles having only a correspondingly small cross section.

Cylinder element 1 for feed channel 4
The arrangement of the channels 6 on opposite sides provides favorable oil flow and lubrication around the jacket surface of the piston member 2. However, the arrangement of channels 6 may be changed as necessary. It is also possible to provide the cylinder element 1 with several channels 6 as well as several feed channels 4, when only the dimensions of the channels are taken into account to provide suitable circulation and lubrication.

[0017] The invention is not limited to the illustrated embodiments; certain modifications can be made within the scope of the appended claims.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a lubricating device of the invention for a piston member of an injection pump.

FIG. 2 is a schematic representation of the circulation of lubricating oil in the cylinder element of the pump according to the device of FIG. 1;

[Explanation of symbols]

1 Cylinder element 2 Piston member 5 Lubrication groove 6 Channel 7 Lubrication channel 8 Nozzle orifice 9 Gap 10 Space

Claims (5)

[Claims] 1. A lubricating device for a piston member (2) arranged to reciprocate within a cylinder element (1) of an injection pump for a pressure medium such as fuel, wherein a lubricant is applied to the cylinder element (1). The lubricant is supplied under pressure to a lubricating groove (5) arranged and surrounding said piston member (2), said lubricant flowing through at least one channel (6) extending in the longitudinal direction of said cylinder element. (1), said channel (6) furthermore collects and recirculates the lubricating groove (5).
A lubricating device, characterized in that it is connected to said lubricating groove (5) in order to continuously lead lubricant to another position on the jacket surface of said piston member (2) at a predetermined distance from ). [Claim 2] The lubricating device according to claim 1,
the channel extending in the longitudinal direction of the cylinder element (
6) is arranged at least substantially opposite the cylinder element (1) with respect to the position of supplying said lubricating oil. 3. The lubricating device according to claim 1,
Said cylinder element (1) has a separate lubrication channel (7) surrounding said piston member (2) and arranged at a predetermined distance from said lubrication groove (5), said lubrication channel (7) , a lubricating device connected to the longitudinally extending channel (6) of the cylinder element and arranged in relation to the covered surface of the piston member (2) to effect lubrication. 4. The lubricating device according to claim 3,
Said lubrication channel (7) connects said piston member (2) via one or several nozzle orifices (8) etc.
A lubricating device connected to the outer covering surface of the 5. A lubricating device according to claim 3 or 4, comprising a lubricant recovery space (
10) on said cylinder element (1) or said element (
1), furthermore a substantial gap (9) is arranged between said cylinder element (1) and said piston member (2) for collecting the lubricant to be collected. From said space (10) collecting lubricant so as to freely conduct the lubricant from said lubrication channel (7) along the jacket surface of said piston member (2) into said space (10). ) a lubricating device extending to the position.