JP4499959B2 - Mounting structure of internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mounting structure for an combustion engine.
[0002]
[Prior art]
Since the cost of an internal combustion engine with a lot of anti-vibration rubber under a common bed (which is fairly sturdy) is high, a direct anti-vibration internal combustion engine with an anti-vibration rubber directly under the mounting foot has recently been introduced. Is becoming popular. In an internal combustion engine of a type that has a sturdy common platform, the common platform absorbs vibration during operation, so there is no problem that the connecting part of the cylinder block and flywheel housing will resonate. In the vibration-proof internal combustion engine, the problem of resonance is serious, and improvements have been attempted by reinforcing the connecting portion between the cylinder block and the flywheel housing.
[0003]
FIG. 4 is a schematic front view of a conventional internal combustion engine 500. In FIG. 4, an internal combustion engine 500 is provided in a cylinder block 80 having a piston 82 and the like that reciprocate up and down by a crankshaft 83, a flywheel housing 81 that houses a flywheel 84 connected to the crankshaft 83, and the cylinder block 80. The mounting foot 85, the mounting foot 86 provided on the flywheel housing 81, and the anti-vibration rubbers 86 and 87 provided below the mounting feet 85 and 86. The cylinder block 80 and the flywheel housing 81 are fastened with bolts 89 and 90.
[0004]
FIG. 5 is a schematic front view of a conventional internal combustion engine 600 different from the internal combustion engine 500. The internal combustion engine 600 is different from the configuration of the internal combustion engine 500 only in that spacers 91 and 92 are provided between the mounting feet 85 and 86 and the anti-vibration rubbers 87 and 88, respectively. Same as the configuration.
[0005]
In the internal combustion engine 500 and the internal combustion engine 600, vibrations generated during operation are transmitted from the mounting feet 85 and 86 (via the spacers 91 and 92 in the internal combustion engine 600) to the anti-vibration rubbers 87 and 88. Incidentally, the cylinder block 80 and the flywheel housing 81 are fastened by the bolts 89 and 90 as described above, and are structurally relatively weak.
[0006]
If the fastening of these two parts is made more rigid, the strength against vibration can be increased and a structure with excellent durability can be realized. However, in reality, various members are mixed in this connecting portion. The structure is such that the rib is difficult to be provided due to interference with the member. Therefore, it is difficult to directly reinforce this connecting portion.
[0007]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a mounting structure for an internal combustion engine in which the connecting portion between the cylinder block and the flywheel housing is not easily damaged.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the invention of claim 1, the cylinder block and the flywheel housing are connected by a mating surface in the longitudinal direction parallel to the crankshaft, and the cylinder block and the flywheel housing are each perpendicular to the crankshaft. has two mounting foot which are spaced along the direction, vibration isolation rubber beneath each mounting foot is disposed, in the mounting structure of the inner combustion engine, mounting foot and anti thereunder between the vibration rubber, is provided with a common shared platform floor at all mounting foot, said common base floor, the natural frequency does not resonate with the vibration generated upon operating an internal combustion engine, the internal combustion engine The common bed is a welded integrated structure, and is formed by a top plate and a bottom plate. Has a structure in which channel-shaped steel or extending H-shaped steel and the widthwise grooves type steel or H-section steel and the formation of the four sides by a frame extending direction is clamped, the common platform bed, occurs upon operating an internal combustion engine It is configured to give the internal combustion engine a natural frequency that does not resonate with the vibration that occurs .
In the invention of claim 2, the cylinder block and the flywheel housing are connected by a mating surface in the longitudinal direction parallel to the crankshaft, and the cylinder block and the flywheel housing are respectively spaced along the width direction perpendicular to the crankshaft. spaced equipped with arranged two mounting foot, the vibration isolation rubber beneath each mounting foot is disposed, in the mounting structure of the inner combustion engine, between the mounting foot and the vibration damping rubber thereunder A spacer is provided for each mounting foot, and the two spacers facing in the longitudinal direction are connected by welding groove steel or H-shaped steel, and the groove steel or H-shaped steel is connected to the internal combustion engine. the natural frequency that does not resonate with the vibration generated upon driving so as to apply to the internal combustion engine It has been made.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment of Invention of Claim 1)
Figure 1 is a schematic front view of the combustion engine 100 among embodying the invention of claim 1. FIG. 2 is a right side view of FIG. In the internal combustion engine 100, a cylinder block 1 is disposed below a cylinder head (not shown), and in the cylinder block 1, there are several pistons 3 that reciprocate in a vertical direction on a crankshaft 4 (six cylinders because there are six cylinders). It is provided.
[0010]
The crankshaft 4 is provided with a flywheel 5 housed in the flywheel housing 2. The cylinder block 1 and the flywheel housing 2 are joined at their mating surfaces 27 with bolts 6 and 7 (actually a larger number of bolts).
[0011]
On the lower side of the cylinder block 1 on the side opposite to the flywheel (left side in FIG. 1), mounting feet 8 and 9 (9 is the other side of the page) are provided. In addition, mounting feet 10 and 11 are provided at the lower portion of the flywheel housing 2. The internal combustion engine 100 is supported by these mounting feet 8-11.
[0012]
A simple common bed 12 is provided under the four mounting feet 8-11. The simple common bed 12 has a structure in which a frame having four sides is sandwiched between an upper plate 13 and a lower plate 14 with groove steels 15 and 16 extending in the longitudinal direction and groove steels 17 and 18 extending in the width direction. Yes. The simple common bed 12 has a welded integrated structure.
[0013]
Furthermore, vibration-proof rubbers 23 to 26 are provided under the simple common base 12. The anti-vibration rubbers 23 to 26 are respectively disposed directly below the mounting feet 8 to 11.
[0014]
As described above, the mating surface 27 of the cylinder block 1 and the flywheel housing 2 is connected by the bolts 6 and 7, has a lower strength than the other parts, and has a deformation pattern unique to the internal combustion engine 100. ing.
[0015]
When vibration of the operating internal combustion engine 100 is transmitted to the mating surface 27, forces (deformation modes) of “vertical bending” and “lateral bending” are applied to the mating surface 27. “Vertical bending” refers to the force with which the mating surface 27 tends to bend in the direction indicated by the arrow 28 in FIG. 1, and “lateral bending” refers to bending from the opposite side of the page to the near side (or vice versa). Refers to the power of
[0016]
On the mating surface 27, an exciting force having a proportional component mainly of primary and tertiary (in the case of 6 cylinders) is generated. When this vibration force increases, the mating surface 27 is greatly deformed and easily damaged. Conventionally, in order to avoid damage (in order to increase the rigidity of the connecting portion), attempts have been made to increase the thickness of the connecting portion of the mating surface 27 or to provide ribs. Nothing is applied to surface 27). Instead, a simple common platform 12 is provided to avoid resonance of the connecting portion.
[0017]
If the resonance frequency during operation of the internal combustion engine 100 is about 45 Hz, the simple common bed 12 is configured so that the natural frequency is 45 ± 5 Hz, for example. The simple common bed 12 is configured to have a natural frequency that does not resonate with vibration according to the engine speed at which the internal combustion engine 100 may be operated. In the example of FIGS. 1 and 2, the grooved steels 15 to 18 are arranged between the upper plate 13 and the lower plate 14. However, instead of the grooved steel, H-shaped steel is used, or the shape of the simple common platform 12 is Any shape can be selected so that the natural frequency does not resonate with the vibration generated by the operation of the internal combustion engine 100.
[0018]
By the inner combustion engine 100 provided with simple common base bed 12, the mating surface 27 can be avoided resonance without untouched, it is possible to prevent damage to the connecting portion of the mating surface 27.
[0019]
As a result of performing FEM analysis with one model pattern, the vertical bending of the mating surface 27 was 50.9 Hz in the state where the simple common base 12 was not provided. 4 Hz. In addition, the lateral bending was 49.9 Hz to 57.6 Hz. Assuming that the resonance frequency is in the vicinity of 45 to 55 Hz, it can be seen that the internal combustion engine 100 has a structure that can reliably avoid resonance by providing the simple common platform 12.
[0020]
(Embodiment of Invention of Claim 2)
Figure 3 is a schematic front view of the combustion engine 200 among embodying the invention of claim 2. In the internal combustion engine 200 of FIG. 3, the same components as those of the internal combustion engine 100 of FIG.
[0021]
The internal combustion engine 200 is different from the internal combustion engine 100 of FIG. 1 only in that spacers 31 to 34 are provided below the mounting feet 8 to 11, respectively. In the internal combustion engine 200, the four spacers 31 to 34 are connected by the simple common platform 30.
[0022]
The simple common platform 30 has no members corresponding to the upper plate 13 and the lower plate 14 provided on the simple common platform 12, and two groove steels 37 and 38 (FIG. 3 shows only the groove steel 37). Are not connected to each other, spacers 31 and 33 are connected (welded) to both ends of the groove steel 37, and spacers 32 and 34 are connected (welded) to both ends of the groove steel 38. Yes.
[0023]
The simple common platform 30 can adopt an arbitrary configuration (for example, adopt an H-shape steel instead of the groove-shaped steel) similarly to the simple common platform 12, but the cylinder block 1 and the flywheel housing 2 are aligned. The surface 27 is configured to have a natural frequency that does not resonate with vibration generated during operation of the internal combustion engine 200.
[0024]
【The invention's effect】
In the present invention, it is possible to prevent damage to the connecting portion without reinforcing the consolidated portion (mating surface 27) directly.
[0025]
[Brief description of the drawings]
1 is a schematic front view of the combustion engine among embodying the invention of claim 1.
FIG. 2 is a right side view of FIG.
Figure 3 is a schematic front view of the combustion engine among embodying the invention of claim 2.
FIG. 4 is a schematic front view of a conventional direct vibration isolation type internal combustion engine.
FIG. 5 is a schematic front view of a conventional direct vibration isolation internal combustion engine different from FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Flywheel housing 5 Flywheel 6, 7 Bolts 8 and 9 Mounting foot 10 and 11 on the cylinder block side Mounting foot 12 on the flywheel housing side Simplified common platform 13 Upper plate 14 Lower plates 15 to 18 Groove type steel 19 to 22 ribs 23 and 24 cylinder block rubber cushion 25 flywheel housing side rubber cushion 27 mating surface 30 simple common base floor 31 to 34 between seat 37 and grooved steel 100, 200 in the combustion engine

Claims (2)

The cylinder block and the flywheel housing are connected by a mating surface in the longitudinal direction parallel to the crankshaft, and the cylinder block and the flywheel housing are respectively spaced apart along the width direction perpendicular to the crankshaft. includes a mounting foot, and rubber vibration isolator is disposed beneath each mounting foot, in mounting structures of the inner combustion engine,
Between the mounting foot and the anti-vibration rubber below it, a common common floor is provided for all mounting feet.
The common bed gives the internal combustion engine a natural frequency that does not resonate with vibration generated when the internal combustion engine is operated ,
The common bed has a welded integrated structure, and a frame having four sides formed by a grooved steel or H-shaped steel extending in the longitudinal direction and a grooved steel or H-shaped steel extending in the width direction is sandwiched between the upper plate and the lower plate. Has a structure
Mounting structure combustion engine among said common base floor, the natural frequency does not resonate with the vibration generated upon operating an internal combustion engine is configured to impart to the internal combustion engine, characterized in that. The cylinder block and the flywheel housing are connected by a mating surface in the longitudinal direction parallel to the crankshaft, and the cylinder block and the flywheel housing are respectively spaced apart along the width direction perpendicular to the crankshaft. includes a mounting foot, and rubber vibration isolator is disposed beneath each mounting foot, in mounting structures of the inner combustion engine,
A spacer is provided for each mounting foot between the mounting foot and the anti-vibration rubber below it.
The two spacers facing each other in the longitudinal direction are connected by welding groove steel or H steel ,
Mounting structure combustion engine inner groove-type steel or H-shaped steel, a natural frequency which does not resonate with the vibration generated upon operating an internal combustion engine is configured to impart to the internal combustion engine, characterized in that.

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