JP2686636B2 - Oil leakage prevention device for fuel injection pump in diesel engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an oil leakage prevention device for preventing leakage of lubricating oil from a fuel injection pump provided outside a main body of an engine in a diesel engine. .

(Prior Art) For example, in a fuel injection device of a diesel engine, a cam shaft of a fuel injection pump is forcibly lubricated with engine lubricating oil. Conventionally, the shaft end of the cam shaft is sealed by an oil seal having a rubber lip.

(Problems to be Solved by the Invention) In the above-described conventional structure, when the engine is operated for a long time, the sliding portion between the cam shaft and the lip portion of the oil seal is abraded to cause oil leakage, which reduces the consumption of lubricating oil. At the same time, the lubricating oil splashes to the outside and pollutes the surrounding area. For this reason, it is necessary to regularly check for oil leakage, and when oil leakage occurs, remove the fuel injection pump, disassemble it, and replace the oil seal.

This is not a big problem when the operating time is short, such as an engine that drives an emergency generator, but for example, a system that drives a regular generator by the engine and recovers waste heat from the engine. In this case, since it is necessary to drive for a long time without stopping the engine, it becomes a big problem.

(Means for Solving the Problem) According to the present invention, the cam of the fuel injection pump 1 is arranged in the fuel injection pump 1 outside the engine body 2 and is located at a position higher than the oil level of the oil pan 7 in the crankcase 6. Axis 12
The bearing 13 that supports the bearing 13 to the support member 14, and the bearing 13 is provided on the circumferential side surfaces of the two rings 15 and 16 fixed to the camshaft 12 so as to be connected to the end surface of the bearing 13 on the camshaft tip side. And the ring 15 from the support member 14 fitted and supported by the case body 11.
A labyrinth seal 17 is formed by projecting an inward projection 14a that is inserted between the opposing surfaces of the support member 14, and the coupling 3 that is located on the shaft end side of the cam shaft 12 and rotates integrally with the cam shaft 12. An annular closed space 18 is formed between the case main body and the outer peripheral edge of the side surface of the coupling 3 facing the closed space 18, and an annular oil draining portion 19 protruding outward in the radial direction is provided to face the bearing 13.
11 The lubricating oil discharged from the lubricating oil pump 21 supplied from the oil pan 7 leaks inside the labyrinth seal 17, and then the leaked lubricating oil is circulated to the oil pan 7 from the hole 14b provided in the support member 14 through the pipe 8. In addition, the inside of the case body 11 is connected to the oil pan 7 through the overflow pipe 24, which is an oil leakage prevention device for a fuel injection pump in a diesel engine.

(Operation) Lubricating oil that has leaked from the labyrinth seal 17 to the shaft end side enters the closed space 18, and is splashed to the inner peripheral wall of the closed space 18 by the centrifugal force generated by the rotation of the oil draining portion 19 of the coupling 3 and the peripheral wall. And flows into the pipe 8, and returns to the inside of the oil pan 7 through the pipe 8.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 is a schematic front view of a diesel engine equipped with an oil leakage prevention device according to an embodiment of the present invention, in which 1 is a fuel injection pump as an example of an auxiliary machine, and the fuel injection pump 1 is outside the engine body 2. The cam shaft (not shown in FIG. 2) of the fuel injection pump 1 installed in the drive shaft 4 is connected to the drive shaft 4 by the coupling 3 as an example of the rotating body. It is driven by the output shaft of the engine through the gears and the like. An oil pan 7 for storing lubricating oil is provided inside the crankcase 6 of the engine body 2.
Is installed, and a pipe 8 is connected to the bottom of the oil pan 7.

FIG. 1 is a cross-sectional view of a main part of an oil leakage prevention device according to an embodiment of the present invention. Inside a case body 11 of a fuel injection pump 1, a cam shaft 12 as an example of a rotating shaft is arranged.
The cam shaft 12 is located at a position higher than the oil surface of the oil pan 7, and the shaft end is rotatably supported by a bearing 13. The bearing 13 is a support member fixed to the end of the case body 11.
The cam shaft 12 is supported by 14, and rings 15, 16 are fitted and fixed on the outer periphery of the cam shaft 12 on the shaft end side of the bearing 13. An annular protrusion 14a that fits into an annular groove formed by the rings 15 and 16 is integrally provided on the inner periphery of the support member 14, and the protrusion 14a and the groove serve as an example of a seal portion. The labyrinth seal 17 of is constructed. An annular closed space 18 is formed on the shaft end side of the labyrinth seal 17 by the support member 14 and the coupling 3, and the closed space 18 communicates with the labyrinth seal 17. An annular protrusion is integrally provided at the end of the coupling 3, and the protrusion constitutes an oil draining portion 19. The case body 11 and the support member 14 constitute a casing 20 of the fuel injection pump 1. One end of the pipe 8 is connected to the bottom of the support member 14, and the other end of the pipe 8 is located in the lubricating oil stored in the oil pan 7. That is, the bottom of the closed space 18 and the lubricating oil in the oil pan 7 communicate with each other through the hole 14b formed in the support member 14 and the pipe 8. The first
In the figure, 21 is a lubricating oil pump for supplying the lubricating oil of the oil pan 7 to the cam shaft 12, 22 is a check valve for preventing the discharge pressure of the lubricating oil pump 21 from exceeding a predetermined value, and 23 is A strainer for removing impurities in the lubricating oil, 24 is an overflow pipe for returning the lubricating oil overflowed in the fuel injection pump 1 to the oil pan 7, and 25 is a coupling 3
Is a nut for fixing the cam shaft 12 to the cam shaft 12, and 26 is a key for transmitting the rotational power from the coupling 3 to the cam shaft 12.

Next, the operation will be described. The lubricating oil leaking from the labyrinth seal 17 to the shaft end side enters the closed space 18. here,
Since the coupling 3 rotates integrally with the cam shaft 12, the centrifugal force of the oil removing portion 19 formed in the coupling 3 causes the lubricating oil to fly to the peripheral wall of the closed space 18, and the lubricating oil flows down along the peripheral wall due to gravity. It flows into the pipe 8 and returns to the oil pan 7 through the pipe 8 due to gravity. At this time, since the other end of the pipe 8 is located in the lubricating oil of the oil pan 7, it is possible to favorably prevent the lubricating oil from flowing backward through the pipe 8 and blowing out into the closed space 18 due to the air pressure in the crankcase 6. .

In this way, the lubricating oil that has leaked from the labyrinth seal 17 can be collected in the oil pan 7 satisfactorily, so it is possible to eliminate the wasteful consumption of lubricating oil due to the leakage of oil, which is economical, and at the same time, the leakage of oil can prevent the surrounding environment. Therefore, the engine can be continuously operated for a long period of time. Further, it is not necessary to regularly check the presence or absence of oil leakage, or to disassemble the fuel injection pump 1 and replace the oil seal of the seal portion, so that labor can be saved.

(Effects of the Invention) As described above, according to the present invention, the lubricating oil leaking from the labyrinth seal 17 can be favorably collected in the oil pan 7, so that the wasteful consumption of the lubricating oil due to the oil leakage can be eliminated. It is economical, and at the same time, does not pollute the surroundings with oil leaks, thus enabling long-term continuous operation of the engine. Further, it is not necessary to regularly check the presence or absence of oil leakage or disassemble the fuel injection pump and replace the labyrinth seal 17, thus saving labor.

The gap of the labyrinth seal 17, that is, the facing gap formed by the rings 15 and 16 and the protrusion 14a is the bearing 1 of the camshaft 12.
3 Adjacent to the end face. Therefore, the lubricating oil leaking from the above-mentioned gap surely lubricates and passes through the bearing 13, and returns to the oil pan 7 through the pipe 8 without stagnation. Further, since the annular oil draining portion 19 projecting outward in the radial direction is provided on the outer peripheral edge of the side surface of the coupling 3 facing the closed space 18, oil passing through the labyrinth seal 17 and adhering to the coupling 3 is drained. Department
It is flown outward in the radial direction at 19 and is reliably captured in the closed space 18 and is prevented from leaking outward (rightward in FIG. 1) from the closed space 18. Further, according to the present invention, no repair is required due to the deterioration of the rubber seal material due to aging, no sludge (residual sand) is attached to the bearing 13 due to the stagnation of the lubricating oil, and the bearing 13 is well lubricated for a long period of time. There is an advantage that the performance of can be maintained.

Since the casing 20 of the fuel injection pump 1 is set with a high injection pressure in order to improve the combustion performance by atomizing the sprayed fuel into the combustion chamber of the internal combustion engine, from the start to the end of the fuel pressure stroke In the meantime, the bearing 13 and the cam shaft 12 receive heat generated by mechanical loss and conduction of heat during engine combustion,
The lubricating oil inside the case body 11 becomes hot, and the seal part (labyrinth seal) provided on the shaft end side of the bearing 13 of the camshaft 12
Oil leakage from 17) is inevitable. The present invention is a casing
While the lubricating oil pumped by the lubricating oil pump 21 at high pressure is positively overflowed into the casing 20, the labyrinth seal 17 is also caused to leak oil to form a closed circuit. It is possible to prevent the occurrence and to circulate and supply the low-temperature and clean lubricating oil from the oil pan 7 to the outside for a long period of time without leaking.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an oil leakage prevention device according to an embodiment of the present invention, and FIG. 2 is a schematic front view of a diesel engine equipped with the oil leakage prevention device according to an embodiment of the present invention. 1 ... Fuel injection pump (auxiliary equipment), 2 ... Engine body,
3 ... Coupling (rotating body), 6 ... Crankcase, 7 ... Oil pan, 8 ... Pipe, 12 ... Cam shaft (rotating shaft), 17 ... Labyrinth seal (seal part), 18
...... closed space, 20 ...... casing

Claims (1)

(57) [Claims] 1. A fuel injection pump (1) arranged on a fuel injection pump (1) outside an engine body (2) and located at a position higher than an oil level of an oil pan (7) in a crankcase (6). (13) for supporting the cam shaft (12) of the bearing to the support member (14), and two fixed to the cam shaft (12) so as to be connected to the end surface of the bearing (13) on the tip side of the cam shaft. Inward from the support member (14), which has a bearing (13) built in and is fitted and supported by the case body (11), on the peripheral side surface of the ring (15, 16) of the ring (15, 16). Protrusion (14a)
To form a labyrinth seal (17), a support member (14), and a coupling (3) located on the shaft end side of the cam shaft (12) and rotating integrally with the cam shaft (12). Between,
An annular closed space (18) is formed, and an annular oil draining portion (19) protruding outward in the radial direction is provided on the outer peripheral edge of the side surface of the coupling (3) facing the closed space (18). ), The discharge lubricating oil from the lubricating oil pump (21) supplied from the oil pan (7) inside the case body (11) leaks from the labyrinth seal (17) and then a hole () is formed in the support member (14). 14
The leakage lubricant from b) is circulated through the pipe (8) to the oil pan (7), and the inside of the case body (11) is connected to the oil pan (7) through the overflow pipe (24). An oil leakage prevention device for a fuel injection pump in a diesel engine.