JP3905636B2 - Lateral vibration damping device for tension bolts of diesel engine frames - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a frame of a crosshead type diesel engine, and more particularly to a structure of a tension bolt mounting portion thereof.
[0002]
[Prior art]
FIG. 3 is a schematic configuration diagram of a crosshead type diesel engine. In FIG. 3, 1 is a base plate, 7 is a crankshaft, and the crankshaft 7 is supported by the base plate 1 via a main bearing (not shown). 2 is a frame, 3 is a jacket, and the jacket 3, frame 2 and base plate 1 are fastened together by a long tension bolt 4 and upper and lower nuts 6 and 5.
[0003]
A plurality of tension bolts 4 are provided on both sides of the cylinder, receiving the explosion pressure in the combustion chamber formed by the cylinder liner, cylinder cover and piston (all not shown), and the base plate 1, the frame 2 and the jacket. 3 is fixed.
[0004]
4 to 5 show a conventional example of the frame of the crosshead type diesel engine and the tension bolt mounting portion thereof, FIG. 4 is a cross-sectional view of the vicinity of the tension bolt mounting portion of the frame, and FIG. FIG. 4 to 5, 2 is a frame, 4 is a tension bolt, and the tension bolt 4 is inserted through the tension bolt insertion space 9 of the frame 2 so as to penetrate vertically. 3 is a jacket, 16 is a top plate to which the jacket 3 is attached, 1 is a base plate, and 17 is a bottom plate for attaching the frame 2 to the base plate 1.
[0005]
The space 9 for inserting the tension bolt 4 is partitioned and formed by an inner partition plate 12, an outer partition plate 13, a lower partition plate 18 and front and rear partition plates 14 and 15, and the tension bolt 4 as described later. Filling oil 8 for attenuating the vibration of the is filled.
[0006]
In the crosshead type diesel engine equipped with the frame 2 and the tension bolt 4 as shown in FIGS. 4 to 5, the tension bolt 4 is subjected to a large tensile load due to the explosion pressure and is long as described above. As a result, lateral vibration due to engine vibration occurs. In order to attenuate the transverse vibration, the filling oil 8 is filled into the space 9.
[0007]
[Problems to be solved by the invention]
As described above, the space 9 through which the tension bolt 4 of the frame of the crosshead type diesel engine is inserted is filled with the filling oil 8 in order to reduce the lateral vibration of the tension bolt 4. However, in the conventional frame, when the space 9 filled with the filling oil 8 is very large compared to the diameter of the tension bolt 4, the vibration of the tension bolt 4 generated during the operation of the engine is sufficiently damped. As a result, the stress acting on the tension bolt 4 becomes excessive, and a failure such as breakage of the tension bolt 4 is observed.
[0008]
The object of the present invention is to obtain a tension bolt mounting structure that can reliably dampen the vibration of the tension bolt without being affected by the size of the tension bolt insertion space of the frame. An object of the present invention is to provide a crosshead type diesel engine in which generation is prevented.
[0009]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and the gist thereof includes a plurality of tensions vertically passing through a base plate that supports a crankshaft via a bearing , a frame and a jacket, and these three members. In a frame for a diesel engine, which is tightened and fixed with bolts, and the space for inserting the tension bolt in the frame is filled with oil that attenuates the lateral vibration of the tension bolt, in each space, on the outer periphery of the tension bolt and exist a small gap is provided a tubular body which is fitted, by the lower end portion of the cylindrical body is secured on the lower surface plate which is provided between the Frame and the base plate, the base plate that the lateral vibration of the tension bolts passing through the Frame and the jacket as received by the tubular body through the fluid film of the filling oil in the gap, to attenuate the transverse vibration of the tension bolt Next vibration damping device of the tension bolt Frames for diesel engines, characterized.
[0010]
According to the above means, in the space of the frame through which the tension bolt is inserted, the gap between the inner periphery of the cylinder provided by being fitted on the outer periphery of the tension bolt and the outer periphery of the tension bolt is as small as about 10 μm. It is formed in a gap, and oil in the space enters the gap to form an oil film. When a lateral vibration is generated in the tension bolt, the lateral vibration is reliably damped by being received by the cylinder through the fluid frictional action of the oil and the cushion film in the minute gap.
[0011]
That is, according to the above means, the oil is caused to enter the minute gap between the inner periphery of the cylinder provided in the space for inserting the tension bolt and the outer periphery of the tension bolt, and the lateral vibration of the tension bolt is caused to enter the gap. Therefore, the vibration damping effect can be greatly increased as compared with the conventional one.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. FIG. 1 is a sectional view of the vicinity of a tension bolt mounting portion in a frame of a crosshead type diesel engine according to an embodiment of the present invention, and FIG. 2 is a view taken along the line BB in FIG.
[0013]
1 and 2, reference numeral 2 denotes a frame, 4 denotes a tension bolt, and the tension bolt 4 is inserted vertically through a space 9 for inserting the tension bolt of the frame 2 so that the frame 2, The jacket 3 and the base plate 1 are tightened together.
[0014]
In the structure of the frame 2, 16 is an upper surface plate to which the jacket 3 (see FIG. 3) is attached, and 17 is a lower surface plate for attaching the frame 2 to the base plate 1 (see FIG. 3). 12 is an inner vertical partition plate, 13 is an outer vertical partition plate, 18 is a lower partition plate, 13 and 14 are front and rear partition plates, and the space 9 for inserting the tension bolt 4 is defined by these It is partitioned by the partition plate. The space 9 is filled with a filling oil 8 for vibration damping. The above configuration is the same as the conventional one shown in FIGS.
[0015]
Reference numeral 10 denotes a spacing cylinder, which is provided in the lower part of the space 9 for inserting each tension bolt. The spacing cylinder 10 is a cylinder fitted to the outer periphery of the tension bolt 4, and the lower end of the spacing cylinder 10 is welded to the lower surface plate 17 and is erected in the lower portion of the space 9. Further, the outer cylinder 10 is welded to the lower partition plate 18 or the outer and front and rear partitions 13, 14, 15 directly or via ribs as required.
[0016]
Further, the inner diameter D ₁ and the height H of the spacing cylinder 10 are (the inner diameter D ₁ ) − (the outer diameter d ₁ of the tension bolt 4) = 10 μ or less, and the height H is equal to the outer diameter d ₁ of the tension bolt. It is preferable to configure it twice or more.
[0017]
As described above, a plurality of tension bolts 4 are provided so as to pass vertically through both sides of the cylinder, and receive an explosion pressure in the combustion chamber formed by a cylinder liner, a cylinder cover, and a piston (all not shown). Thus, the base plate 1, the frame 2, and the jacket 3 are fixed. Therefore, a large tensile load due to the explosion pressure acts on the tension bolt 4 and a lateral vibration due to the engine vibration occurs.
[0018]
As described above, the space 9 is filled with the filling oil 8 in order to attenuate the lateral vibration. However, the spacing cylinder 10 is fixed to the lower portion of the space 9, and the gap 20 between the inner circumference (inner diameter D ₁ ) of the spacing cylinder 10 and the outer circumference (outer diameter d ₁ ) of the tension bolt 4 is as described above. Thus, the filling oil 8 enters the gap 20 and attenuates the lateral vibration of the tension bolt 4 by fluid friction and cushion action. Therefore, as described above, a very small narrowed gap 20 is formed on the outer periphery of the tension bolt 4, and the filling oil 8 is allowed to enter the gap to cause lateral vibration of the tension bolt 4 to cause the filling oil 8 in the gap 20. The damping effect of the vibration is greatly increased by being received by the spacing cylinder 10 via the fluid film. Thereby, the stress (vibration stress) due to the lateral vibration of the tension bolt 4 is significantly reduced.
[0019]
【The invention's effect】
The present invention is configured as described above. According to the present invention, oil is allowed to enter a minute gap between the inner periphery of the cylinder and the outer periphery of the tension bolt provided in the lower part of the space for inserting the tension bolt. Thus, the lateral vibration of the tension bolt is received by the cylinder through the fluid friction of the oil in the gap and the cushion film, so that the vibration damping effect can be greatly increased compared to the conventional one. . Thereby, the stress of the tension bolt is reduced, and the breakage of the tension bolt due to excessive vibration stress can be prevented in advance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a vicinity of a tension bolt mounting portion in a crosshead type diesel engine frame according to an embodiment of the present invention.
FIG. 2 is a view taken along arrow BB in FIG.
FIG. 3 is a schematic configuration diagram showing a tension bolt tightening state of a crosshead type diesel engine.
FIG. 4 is a diagram corresponding to FIG. 1 showing a conventional example.
5 is a view taken along the line AA in FIG.
[Explanation of symbols]
1 Base plate 2 Frame 3 Jacket 4 Tension bolt 5 Lower nut 6 Upper nut 7 Crankshaft 8 Filling oil 9 Space 10 Spacing cylinder 12, 13, 14, 15 Partition plate 16 Top plate 17 Bottom plate 18 Partition plate

Claims (1)

The base plate that supports the crankshaft through the bearing , the frame and the jacket are fastened and fixed by a plurality of tension bolts that penetrate the three members up and down, and the tension is inserted into the space for inserting the tension bolt in the frame. In a diesel engine frame that is filled with oil that attenuates the lateral vibration of the bolt, each cylinder is provided with a cylindrical body that is fitted with a small gap around the outer periphery of the tension bolt. the lower end by fixing on the lower surface plate which is provided between the Frame and the base plate, the lateral vibration of the tension bolts passing through the said base plate and Frames and the jacket in the gap of as received by the tubular body through the fluid film of the filling oil, transverse vibration of the tension bolt of Frames for diesel engines, characterized in that for attenuating the transverse vibration of the tension bolt Decay apparatus.

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