JP3691244B2 - Piston type internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piston-type internal combustion engine having at least one piston provided with a piston rod, in particular a large diesel engine.
The piston has at least one cooling chamber, and the cooling chamber includes a heat transfer agent. This heat transfer agent can be cooled in a cooling device to which the coolant is sprayed.
[0002]
[Prior art]
A similar arrangement is known from EP 0 074 156. In this known configuration, a heat exchanger that closes the cooling chamber is provided in the piston. This arrangement is therefore relatively expensive to manufacture and requires additional components. Moreover, the cooling surface obtained by this configuration is relatively small. In addition, the heat exchanger has a risk of breaking due to high load. Therefore, there is a great risk of leakage.
[0003]
[Problems to be solved by the invention]
Therefore, the object of the present invention is to improve the above-mentioned type of apparatus by simple and inexpensive means so that high reliability and excellent cooling effect can be obtained even with a simple and inexpensive structure.
[0004]
[Means for Solving the Problems]
The above problems are solved by the present invention as follows. That is, a recess is provided in at least a part of the piston rod in the longitudinal direction. The recess is connected to the cooling chamber of the piston and forms a closed hollow system with the cooling chamber. The hollow system is partially filled with the heat transfer agent. Furthermore, the stone bar has a cooling surface on which coolant is sprayed corresponding to the recess.
[0005]
In the present invention, the piston rod is preferably used as a heat exchanger. Therefore, it is not necessary to use an additional member. The necessary recess can be easily formed. At the same time, a high degree of robustness and safety against leakage is guaranteed. The piston rod also has a relatively large heat transfer surface. That is, the piston rod is a relatively long and thick component. In the present invention, the heat transfer agent is moved according to the principle of a cocktail shaker by the back-and-forth movement of the piston and the piston rod, thereby achieving a good heat transfer, good heat uniformity, and reliable piston. To be cooled. For the above reasons, the present invention guarantees high efficiency and excellent economic efficiency.
[0006]
Preferred configurations and further formations of the means of the upper claim are set forth in the subclaims. Thus, the recesses of the piston rod are preferably formed as axial blind holes emanating from the cooling chamber, and these recesses reach the bottom of the piston rod on the cross rod side, away from the piston. . As a result, the recess penetrates substantially the entire length of the piston rod, and a groove is formed in a suitable manner extending parallel to the direction of movement of the piston rod. This ensures good exchange of the heat transfer agent. In addition, a coating as a desirable casing is automatically provided.
[0007]
For the purpose of giving direction to the flow and increasing the residence time of the heat transfer agent, the recesses of the piston rods may be joined to each other to form a single through groove. In that case, opposing check valves are provided at the inlet and the outlet on the piston side of the groove.
[0008]
The recess of the piston rod is preferably provided in the vicinity of the periphery of the piston rod. As a result, the entire relatively large circumferential surface of the piston rod functions as a heat release surface.
[0009]
As a further preferred form, at least a part of the length of the piston rod is sprayed with coolant from the outside via an injection nozzle. This promotes heat release outside the piston rod and ensures reliable cooling of the heat transfer agent.
[0010]
As another preferred means, the piston rod is provided with a cooling groove on which a coolant is sprayed adjacent to the recess corresponding to the heat transfer agent. Thereby, internal heat release is also suitably performed.
[0011]
The cooling groove is formed as an axial blind hole emanating from the end of the piston rod on the crosshead side. Lubricating oil can be sprayed into the blind hole by a crosshead lubricating oil system. This measure allows a particularly simple implementation with a high cooling effect.
[0012]
For the purpose of giving direction to the flow and increasing the residence time of the coolant inside the piston rod, several cooling grooves are connected to each other to form a single through groove. And a check valve that opposes the outlet.
[0013]
Other suitable configurations for the means described in the upper claims and further forms suitable for the purpose are described in the subclaims. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Several embodiments of the present invention will be described below in detail with reference to the drawings. The drawings show the following.
FIG. 1 shows a first embodiment according to a vertical section of the structure of a large two-stroke diesel engine consisting of a piston, a piston rod and a crosshead;
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a horizontal sectional view of a piston rod formed from a plurality of members;
FIG. 4 shows a second embodiment of the invention shown corresponding to FIG.
FIG. 5 is a sectional view taken along line VV in FIG.
[0015]
The structure and working of a large two-cycle diesel engine and the methods used to drive ships and others are well known. This type of engine has a plurality of driving devices each provided with a piston 2 provided in a corresponding cylinder 1. The piston is fixed to a corresponding cross head 5 slidably supported on the engine frame via a piston rod 3. The piston rod 3 transmits the reciprocal motion of the piston 2 to the crosshead 5. The cross head is coupled to a crankshaft (not shown) provided in a lower region of the engine frame 4 through driving of a connecting rod not shown in detail. The crosshead 5 has a slide shoe that is slid onto a guide 6 in the vertical direction of the engine frame 4. The slide shoe is supplied with lubricating oil by a lubricating oil device 7.
[0016]
The head of the piston rod 3 is fixed to the piston 2 with a bolt. The bottom portion of the piston rod 3 is fixed to a lateral member (Joch) of the crosshead 5 that bridges the slide shoe with a bolt. The piston 2 defines a combustion chamber on its upper side, and since the inside is cooled, a relatively thin wall thickness is realized. Furthermore, the piston 2 has a defined internal cooling chamber 8 at the upper part by the bottom part of the piston and at the lower part by the head part of the piston rod 3. A branch pipe formed by a recess 9 provided in the axial direction in the piston rod 3 protrudes from the internal cooling chamber. The branch pipe is in this case formed as an axial blind hole that penetrates substantially the entire length of the piston rod 3 and terminates at the bottom of the piston rod. As shown in FIG. 2, the blind holes in the axial direction are provided on an arc concentric with the axis of the piston rod with the same angular distribution. In the illustrated example, eight recesses 9 are provided that are shifted from each other by 45 °. These recesses have a small diameter of 15-50 mm, preferably 25 mm.
[0017]
The cooling chamber 8 and the recess 9 form a hollow system that is closed to the outside. The hollow system contains a heat transfer agent, such as water or glycol, which is only partially filled and has excellent heat transfer properties, as indicated by the level line 10. The filling level indicated by the level line 10 is 60-90% of the volume of this hollow system. While the engine is running, the back-and-forth movement of the piston 2 and piston rod 3 produces the same effect as seen in a cocktail shaker. Accordingly, the heat transfer agent contained in the cooling chamber 8 is constantly exchanged. The heat transfer agent is supplied with heat in the region of the piston 2 and releases the heat again in the region of the piston rod 3, thereby ensuring that the piston 2 is cooled.
[0018]
Since the piston rod 3 is a very long and relatively thick component, a relatively large outer surface is produced. Through this outer surface, the heat released from the heat transfer agent is released to the surroundings. 1 to 3 are based on this type of implementation. In this case, the recess 9 of the piston rod 3 is provided in the outer edge region of the piston rod 3 with a slight wall thickness. Accordingly, the corresponding arc also extends near the outer edge. The circumferential surface of the piston rod 3 is sprayed with coolant from the outside in order to enhance the heat release. As the coolant, the lubricant that is originally used in the engine can be used as it is.
[0019]
For this purpose, as can be seen from FIG. 1, a large number of injection nozzles 11 to which a coolant such as lubricating oil is sprayed are provided, and the piston rod 3 in the region of the guide 6 of the corresponding crosshead 5 is provided by these injection nozzles. The coolant is sprayed on the area of the above, thereby cooling from the outside.
[0020]
It is preferable that the injection nozzles 11 are provided so that several each face each other on the circumferential side. In the illustrated example, as can be seen from FIG. 2, the guide 6 is provided on both sides, and a nozzle bar having a plurality of overlapping injection nozzles 11 is provided in all the four corners of the shaft through which the piston rod passes. It has been. As a result, the coolant is sprayed uniformly over the entire circumference of the piston rod 3 and a relatively large length. The injection nozzles 11 are connected to the corresponding crosshead lubricating oil devices 7 via corresponding supply lines 12, whereby the coolant is supplied in a simple manner. The oil injected into the piston rod for cooling the piston rod 3 is easily discharged into the crank chamber. In a simple configuration, it is sufficient to apply cooling air to the piston rod 3 here.
[0021]
The recess 9 is simply formed as a blind hole. This manufacturing method becomes a problem when the piston rod 3 is formed integrally. In the embodiment according to FIG. 3, the piston rod 3 consists of an inner core 14, which is surrounded by a sleeve 15. In this case, the inner core 14 and / or the sleeve 15 is provided with a groove for forming the recess in the region of the outer peripheral surface or inner peripheral surface thereof. The groove is provided from the casting stage and is then subjected to finish cutting or formed entirely by cutting.
[0022]
Alternatively, some or all of the recesses in the piston rod 3 are each joined together in a distal region away from the lower piston, as indicated by the dashed line 16 in FIG. As a result, a through groove having a branch for traveling and retrograde is provided. As shown by a broken line in FIG. 1, a check valve 17 or 18 in the reverse direction is provided in the region of the through groove inlet or outlet. These check valves are opened only in the inflow direction or only in the outflow direction. This directs the flow. Even if a plurality of recesses are combined to provide a single groove, the residence time of the heat transfer agent in the piston rod 3 region is increased, thereby improving the cooling effect as a whole. Furthermore, in such an embodiment, the filling level of the closed system consisting of the cooling chamber 8 and the recess 9 is relatively high.
[0023]
In the embodiment according to FIGS. 4 and 5, the piston rod 3 is internally cooled. For this purpose, a recess 19 is provided adjacent to the recess 9 of the piston rod 3 emanating from the cooling chamber 8. These recesses 19 function as cooling grooves into which a coolant such as lubricating oil is sprayed. As can be seen from FIG. 5, these recesses 19 are provided on an arc concentric with the arc of the recess 9. In the illustrated embodiment, the recess 9 emanating from the cooling chamber 8 is provided on the inner arc, and the recess 19 forming the cooling groove is provided on the outer arc.
[0024]
The recess 19 forming the cooling groove is formed as a blind hole emanating from the end of the piston rod 3 on the crosshead side. The blind hole reaches the head of the piston rod 3 and terminates below the end surface of the piston rod that defines the cooling chamber 8 at the head of the piston rod. The recess 19 can be formed as a blind hole like the recess 9, but it is also conceivable to form it as shown in FIG. In that case, it seems that two jackets are necessary. In order to supply lubricating oil to the recesses 19 functioning as cooling grooves, the recesses are simply connected to the corresponding lubricating oil device 7 of the crosshead 5. For this purpose, the crosshead 5 is provided with a branch pipe that leads to the recess 19 open on the crosshead side.
[0025]
In order to extend the residence time of the lubricating oil and to give direction to the flow, several or all of the cooling grooves are connected to each other so that an inlet and an outlet on the crosshead side are formed. Is also possible. The same applies to the recess 9 emanating from the cooling chamber 8. As already described in detail with reference to FIG. 1, the recesses can be connected to each other such that an inlet and an outlet on the piston side are provided, respectively, and 17 and 18 in FIG. As shown, a reverse check valve is provided. In the region of the groove formed by the recesses 19 connected to each other, there is already a flow directed by the hydraulic pressure, so one check valve is sufficient or no check valve is required.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a structure of a large two-cycle diesel engine according to a first embodiment of the present invention.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a horizontal sectional view of a piston rod according to the present invention formed from a plurality of members.
FIG. 4 is a longitudinal sectional view of a structure of a large two-cycle diesel engine according to a second embodiment of the present invention.
5 is a cross-sectional view taken along line VV in FIG.
[Explanation of symbols]
2 Piston 3 Piston rod 5 Crosshead 8 Cooling chambers 9 and 19 Recess 11 Injection nozzle 14 Internal core 15 Sleeves 17 and 18 Check valve

Claims (19)

At least one piston (2) with a piston rod (3), said piston having at least one cooling chamber (8), a heat transfer agent being contained in the cooling chamber, the heat transfer agent being A piston-type internal combustion engine, particularly a large diesel engine, capable of being cooled in a cooling device to which a coolant is sprayed,
A recess is provided in at least a part of the longitudinal direction of the piston rod (3), and the recess is connected to the cooling chamber (8) of the piston (2) and closed together with the cooling chamber. Forming a system, the hollow system being partially filled with the heat transfer agent, the piston rod (3) having a cooling surface corresponding to the recess into which the coolant is sprayed Piston type internal combustion engine.   2. A piston-type internal combustion engine according to claim 1, wherein the recess (9) of the piston rod (3) is formed as an axial blind hole extending from the cooling chamber (8).   The recess (9) of the piston rod (3) reaches the bottom on the crosshead side of the piston rod (3), which is separated from the piston (2). 2. A piston-type internal combustion engine according to 2. At least some of said recess (9) of the piston rod (3) is, according to any one of claims 1 to 3, characterized in that it is coupled together at an end region remote from the at least a piston Piston type internal combustion engine.   5. A piston-type internal combustion engine according to claim 4, wherein a check valve (17, 18) in the reverse direction is provided at the piston inlet and outlet of the recess (9) connected to each other. .   6. The piston type internal combustion engine according to claim 1, wherein the recess (9) is provided on an arc concentric with the axis of the piston rod (3).   The piston type according to any one of claims 1 to 6, wherein the recess (9) is provided in the vicinity of an outer edge of the piston rod (3), and an outer surface of the piston rod can be cooled. Internal combustion engine.   The piston type internal combustion engine according to claim 7, wherein at least a part of the piston rod (3) in the longitudinal direction is sprayed with a coolant from outside by an injection nozzle (11). A plurality of injection nozzles (11) provided in multiple stages are respectively disposed in the four corner regions of the shaft having a rectangular cross section formed in the engine frame so that the piston rod (3) is inserted. 9. A piston type internal combustion engine according to claim 8, wherein:   The piston type internal combustion engine according to any one of claims 1 to 9, wherein the injection nozzle (11) is sprayed with lubricating oil through a lubricating oil system on the engine side. 11. The piston rod (3) is provided with a recess (19) close to a recess (9) corresponding to the heat transfer agent and to which a coolant is sprayed. A piston type internal combustion engine according to any one of the descriptions.   The piston-type internal combustion engine according to claim 11, wherein the recess (19) is provided on an arc concentric with the axis of the piston rod (3).   The piston-type internal combustion engine according to claim 11 or 12, characterized in that the recess (19) is formed as a blind hole emanating from an end of the piston rod (3) on the crosshead side.   The said recess (19) has penetrated in the longitudinal direction of the said piston rod (3) to just before the piston side edge part of this piston rod (3), Any one of Claim 11 thru | or 14 characterized by the above-mentioned. A piston-type internal combustion engine according to claim 1. 15. Piston according to any one of claims 11 to 14 , characterized in that the recess (19) is sprayed with lubricating oil via a lubricating oil device (7) provided in the crosshead (5). Internal combustion engine.   16. The piston-type internal combustion engine according to claim 11, wherein at least some of the recesses (19) are connected to each other at least at the piston end.   17. The piston type internal combustion engine according to claim 16, wherein a check valve is provided in the recesses (19) connected to each other in the inlet region on the crosshead side.   18. The piston-type internal combustion engine according to claim 1, wherein at least a part of the recess (9 or 19) of the piston rod (3) is formed as an axial through hole. . The piston rod (3) comprises an inner core (14) and at least one sleeve (15) surrounding the inner core, and at least a part of the recess (9 or 19) of the piston rod (3) is The piston-type internal combustion engine according to any one of claims 1 to 18, wherein the piston-type internal combustion engine is formed by a groove formed in an outer surface of the inner core or an inner surface of the sleeve .

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