JPH0124357Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an internal combustion engine in which cylinder liners are assembled with tension applied in opposite axial directions.

(Prior Art) In conventional internal combustion engines, the cylinder liner is attached to the cylinder block using a dry or wet structure, but these structures have the following problems.

(a) Conventional cylinder liners use Fe castings, such as centrifugal castings, due to sliding surface characteristics.
It had to be thick because it needed to maintain its own rigidity. Therefore, the cylinder spacing was large for both dry and wet liners.

(b) The dry liner structure requires an extra pilot hole to be bored in the cylinder block, which increases costs, and the cast-in installation method has poor workability and is a factor in increasing manufacturing costs.

(c) Wet liners require consideration for a watertight structure, leading to increased costs.

(Purpose of the invention) This invention is intended to solve the above problem, and improves the rigidity of the cylinder liner by applying tension to the cylinder liner in opposite axial directions and assembling it into a split cylinder block. It is an object of the present invention to provide an internal combustion engine which can thereby achieve thinner walls, improve watertightness by ensuring the connection between a cylinder block and a cylinder liner, and achieve a reduction in size and weight.

(Structure of the Invention) In order to achieve the above object, the internal combustion engine of the present invention includes outward facing flanges formed on the circumferential edges of both ends of a cylinder liner made of a steel pipe so as to apply tension to the cylinder liner in its axial direction. The cylinder liner is assembled into a split cylinder block that is either integral with the cylinder head or separate from the cylinder head.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2 showing a first embodiment of the present invention, 1 is a cylinder block, and 2 is a cylinder liner made of a steel pipe. This steel pipe also means a steel pipe made of a composite material with iron-based sintered material.

The cylinder block 1 consists of a first cylinder block body 3 and a second cylinder block body 4, which are vertically divided into two along the two-dot chain line A in FIG. The first and second cylinder block bodies 3 and 4 are connected in a watertight manner by intervening and tightening both ends of the split surface with fasteners 6 made of bolts and nuts.

The cylinder liner 2 has outwardly facing annular flange portions 2a formed on the periphery of both upper and lower ends, and both annular flange portions 2a are
The cylinder liner 2 is locked to the first and second cylinder block bodies 3 and 4 so that tension is applied to the cylinder liner 2 in opposite axial directions when the first and second cylinder block bodies 3 and 4 are connected, cylinder block 1
It is assembled into. The locking of the flanges 2a at both ends of the cylinder liner 2 is achieved by semicircular stepped portions 7 formed at the upper ends of the inner peripheral surfaces of the first and second cylinder block bodies 3 and 4, respectively, which form the cylinder liner insertion bore.
When the first and second cylinder block bodies 3, 4 are connected to the semicircular groove 8 formed near the lower end,
These flanges 2a are arranged so that there is a gap e between the outer circumferential surface of the cylinder liner 2 and the outer circumferential surface of the bore portion of the cylinder block 1.
This is done by temperature differential fitting to form a . The temperature difference level during temperature difference fitting shall be at least the maximum value under the engine operating environment. Note that the cylinder block 1 exerts a tensile force on the cylinder liner 2.
Since the contact surfaces of the stepped portion 7 and the groove portion 8 with the flange portion 2a are sufficiently finished, watertightness at these portions is maintained.

In an internal combustion engine having such a configuration, the cylinder liner 2
Since axial tension is applied to the cylinder liner 2, the rigidity of the cylinder liner 2 is improved together with its own material, and the connection between the cylinder block 1 and the cylinder liner 2 is ensured. It is also possible to make the wall thin enough to withstand explosive force. For example, the conventional cylinder liner 2 made of Fe casting had a wall thickness of 4 to 5 mm, but with the present invention, it can be made extremely thin to 3 mm or less. This extremely thin wall improves cooling performance. Furthermore, the cylinder interval C shown in FIG. 1 can also be made smaller.

In FIGS. 1 and 2, 9 is a positioning pin hole of the cylinder block 1, 10 is a threaded hole for a tension bolt, 11 is a water jacket, and 12 is a cooling water passage.

Next, a second embodiment of the present invention is shown in FIG. 3, and a third embodiment of the present invention is shown in FIG. 4. In both the second and third embodiments, the cylinder liner 2 of the first embodiment is combined with cylinder blocks 13, 13' integrated into the cylinder head.
This block 13,1
The structure is the same except that 3' has a wet liner structure or a dry liner structure, and the other structure is the same as that of the first embodiment. Below, the second and third
Examples will also be described.

The cylinder blocks 13 and 13' are formed by integral first cylinder block bodies 14 and 1, which are vertically divided into two by the packing 5 in FIGS. 3 and 4, respectively.
4' and integrated second cylinder block body 15,1
5', and as in the first embodiment, the first and second cylinder block bodies 14, 15 and 14',1
5' are integrated. Then, when assembling the unit, the cylinder liner 2 is fitted with a temperature difference,
As in the first embodiment, the cylinder liner 2 is assembled with tension applied in the axial direction.

In such a configuration, the integrated first cylinder block bodies 14, 14' and the integrated second cylinder block bodies 15, 15' are capable of absorbing a horizontal tightening force by the fastener 6 and a longitudinal tightening force by the cylinder liner 2. are firmly connected.

In this split-type cylinder head-integrated cylinder block 13, 13, a cooling water passage can be easily formed, the casting can be made thinner and more uniform, and cracks due to uneven thickness do not occur, and the casting method is also improved. Moreover, because it is integrated, it has high rigidity and exhibits excellent natural frequency characteristics.

FIG. 5 shows a fourth embodiment of the present invention. This internal combustion engine consists of parts obtained by dividing the cylinder block horizontally and vertically into four parts, that is, the left and right cylinder block bodies 16 and 17 with integral cylinder heads on the upper side in FIG. 5, and the left and right cylinder block bodies 18 on the lower side in FIG.
19, to which the cylinder liner 2 is mechanically assembled at room temperature, and the other configurations are the same as in the first to third embodiments.

To assemble the cylinder liner 2 to this cylinder block, first attach the flanges 2a at both ends of the cylinder liner 2 to the upper left and right integrated cylinder block body 1.
When joining 6 and 17, fit it into the stepped part 7,
It is fitted into the groove 8 when the lower left and right cylinder blocks 18 and 19 are joined together. Watertight spacers 21 are interposed between the horizontally dividing surfaces of these cylinder block bodies 16, 17, 18, and 19, and are formed alternately on the horizontally dividing surfaces of these cylinder block bodies 16, 17, 18, and 19. Of the flange parts D and E (see Fig. 6), the flange part E is tightened with a fastener 6 as shown in Fig. 5. More specifically, by rotating the bolt 20 screwed into the flanges of the lower cylinder blocks 18, 19 at the flange D, the corresponding flanges of the upper cylinder blocks 16, 17 are pushed up, and the space is By inserting the spacer 21 shown in FIG. 7 so that each bolt 20 fits into the bolt notch 21a, the flanges 2a at both ends of the cylinder liner 2 are removed.
The cylinder liner 2 is pressed in opposite directions so as to apply tension in the axial direction. Finally, the flange E is tightened with the fastener 6 while the cylinder liner 2 is pretensioned, and the integrated cylinder bodies 16, 17 and the cylinder block body 1 are assembled.
Combine 8 and 19.

In this internal combustion engine, the cylinder liner 2 can be easily mechanically assembled into a pretensioned state at room temperature without temperature differential fitting.

(Effects of the invention) As explained above, according to the invention, since the cylinder liner is assembled to the split type cylinder block while applying tension in the axial direction, the rigidity of the cylinder liner can be improved together with the material of the cylinder liner itself. This makes it possible to make the cylinder liner itself thinner and improve its cooling performance, as well as ensure the connection between the cylinder block and cylinder liner, and ensure that the flange of the cylinder liner and the part of the cylinder block that locks it are tightly connected. Contact improves watertightness. Furthermore, since the cylinder liner can be made thinner, the cylinder spacing can be reduced, and the internal combustion engine itself can be made smaller and lighter.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the first embodiment of the present invention, Fig. 2 is a sectional view taken along the line - - in Fig. 1, Fig. 3 is a sectional view showing the second embodiment of the invention, and Fig. 4. is a sectional view showing the third embodiment of the present invention, FIG. 5 is a sectional view showing the fourth embodiment of the invention, FIG. 6 is a schematic diagram showing the cylinder block of FIG. 5, and FIG. It is a perspective view which shows the spacer attached to the thing of a figure. 1...Cylinder block, 2...Cylinder liner, 2a...Flames at both ends of cylinder liner, 3...
First cylinder block body, 4... Second cylinder block body, 7... Step portion, 8... Groove portion.

Claims (1)

[Scope of utility model registration request] The outward facing flanges formed on the periphery of both ends of a cylinder liner made of a steel pipe are locked so as to apply tension to the cylinder liner in its axial direction, and the cylinder liner can be attached to a cylinder head either integrally or separately from the cylinder head. An internal combustion engine assembled into a cylinder block.