JPH1061485A - Cylinder block of v-type dry liner engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the stiffness of a jacket inner wall of a cylinder block, and lower vibration, by arranging intermediate decks between a top deck and a lower deck of the cylinder block having the dry liner structure of a V-type engine, and also connecting intermediate deck parts to each other by a connecting member. SOLUTION: Intermediate decks 4 are arranged among top decks 2 and lower decks 3 so as to surround the peripheries of cylinder liners 7, so that a water jacket 6 formed in the cylinder block 1 of a V-type engine, is divided into two in a piston sliding direction. Then, the parts of the intermediate decks 4 on right and left banks are connected to each other through a connecting member 5. Hereby, the structure of the parts of the inner circumferential walls 8a and peripheral walls 8b of the water jackets 6a, 6b can be reinforced, and also the right and left banks of these intermediate deck 4 parts are connected to each other by the connecting member 5, thereby stiffness is enhanced and vibration is suppressed. Also, vibration in water jackets 6a, 6b is reduced, thereby cavitation erosion can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-type engine employing a dry liner system in which a cylinder liner is inserted into a cylinder block of a V-type engine and the outer periphery of the cylinder liner is indirectly cooled through the inner peripheral wall of a water jacket. The present invention relates to improvement of a cylinder block of a dry liner engine.

[0002]

2. Description of the Related Art A cylinder cooling system for a cylinder block of a small water-cooled engine such as an automobile has a cylinder portion as a separate body, a wet liner system provided with a cylinder liner, and a cylinder portion formed integrally with the block. The inserted dry liner method is often used.

A dry liner type cylinder block is
A water jacket for passing cooling water for cooling the cylinder is provided. The water jacket is formed by being surrounded by an inner peripheral wall of the jacket, an outer peripheral wall of the jacket, a top deck as a cylinder head mounting surface, and a lower deck. As one of the conventional techniques of a cylinder block structure of a V-type engine employing such a dry liner system, as shown in FIGS. 7 and 8, between a top deck 2 and a lower deck 3 of a cylinder block 1. Are formed to form a water jacket 6, and a middle block of an outer peripheral wall 8 b of the water jacket 6 is connected to the left and right banks by a connecting member 5.

[0004]

However, in the case of a cylinder block structure in which the connecting member 5 is connected to an intermediate position of the water jacket 6 as shown in FIGS. 7 and 8, the side wall of the water jacket 6 reduces the engine weight. Therefore, since the span L is long and the rigidity of the outer peripheral wall 8b of the jacket is small, the connecting portion 5a to which the connecting member 5 is connected when the engine is operating.
Then, a displacement of compression and tension occurs in the direction of arrow ZW,
Jacket outer peripheral wall 8b of the opposite bank via connecting member 5
Excitation of the center of. Due to the interaction between the left and right banks, vibrations in the X-Y directions are likely to occur on the jacket outer peripheral wall 8b,
Engine noise increases.

[0005] In addition, cavitation occurs in the jacket inner peripheral wall 8a due to vibration caused by fluctuations in piston side pressure. Due to this cavitation, erosion occurs on the inner surface of the water jacket 6 of the cylinder block 1, and in the worst case, the erosion develops, causing perforations and cracks in the inner circumferential wall 8a of the jacket, causing a major engine trouble. I was

In order to suppress these vibrations, the rigidity of the cylinder block has been increased by increasing the thickness of the inner and side walls of the water jacket and the top deck and the lower deck, and by adding reinforcing ribs. All of these measures have the problem of increasing the weight of the engine and are not effective. Regarding the above problem, FIGS. 9 and 10
It is conceivable to reduce the length L of the water jacket 6 to increase the rigidity of the jacket inner peripheral wall 8a and the jacket outer peripheral wall 8b of the water jacket 6, thereby reducing vibration and noise.

However, in the structure of the cylinder block, in order to increase the thickness of the robbed portion 11 of the cylinder side wall 8c at the lower portion of the cylinder and to form the cylinder block with a thin wall due to manufacturing problems, the shape of the core must be reduced. It is necessary to make it with high accuracy and hold it accurately, but there is a limit in the point of accurate position holding due to the problem of the strength of the core, and the metal part of the cross section of the cylinder block 1 in FIGS. As can be clearly understood from the comparison of the areas of the above, simply stealing the meat from the outside increases the metal part of the cylinder block 1 as shown in FIG. 10 and greatly increases the weight. Does not solve.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve the rigidity of the inner wall of a jacket of a cylinder block and suppress the vibration of the side wall of the jacket while minimizing the increase in the weight of the engine. Another object of the present invention is to provide a lightweight V-type dry liner engine cylinder block which can prevent damage due to cavitation erosion and reduce noise, and is easy to cast.

[0009]

In order to achieve the above object, in a cylinder block having a dry liner structure of a V-type engine, an intermediate deck is provided between a top deck and a lower deck of the cylinder block. The present invention further provides a cylinder block of a V-type dry liner engine in which the intermediate deck portions of the left and right banks of the V-type engine are connected by a connection member.

[0010] A hollow portion is provided between the intermediate deck and the lower deck. This hollow portion may be a completely closed space, but it may have an opening on the outer surface of the cylinder block and be connected to the outside air, or may have an opening on the oil pan side and have the inside of the crankcase. You may be connected with. In any case, the intermediate deck and the lower deck are formed so as to be connected by a thin inner peripheral wall and an outer peripheral wall. Preferably, the cavity has an opening in the cylinder-side inner peripheral wall, and the opening is formed so as to be closed by a cylinder liner.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In the first embodiment, the right and left cylinder blocks 1 and the crankcase 10 are integrally formed in a cylinder having a dry liner structure of a V-type engine, as in a normal water-cooled engine.

The cylinder block 1 is provided with a top deck 2 which is a cylinder head mounting surface and a lower deck 3 which constitutes a lower portion of the cylinder.
A lower surface oil pan mounting portion 18 for mounting an oil pan is provided at a lower part of the oil pan 10. A dry liner 7 forming an inner peripheral surface of the cylinder is fitted on the inner surface side of the cylinder 9 of the cylinder block 1, and a water jacket 6 for passing cooling water for cooling the cylinder 9 is provided around the dry liner 7. This water jacket 6 is a jacket inner peripheral wall 8.
a, the jacket outer peripheral wall 8b, the top deck 2, and the lower deck 3.

In the cylinder block 1, an intermediate deck 4 is provided between the top deck 2 and the lower deck 3 so as to surround the outer periphery of the cylinder liner 7 so as to bisect the water jacket 6 in the sliding direction of the piston. And the middle deck 4 of the left and right banks of the V-type engine
Are connected by the connecting member 5. The crankcase 10 at the lower portion of the cylinder block 1 supports the crank journal 12 for holding the crankshaft and the cam journal 14 for holding the camshaft by tightening the main bearing cap 13 from below, and these are integrally supported. A partition 16, a reinforcing member rib 15 for reinforcing the partition 16, a crankcase side wall 17, a lower oil pan attachment 18, a tappet 19, and the like are provided.

With the above construction, the inner jacket wall 8a and outer jacket wall 8b are provided between the top deck 2 and the lower deck 3 of the cylinder block 1 by the intermediate deck 4 provided so as to divide the water jacket 6 in the vertical direction.
Since the left and right banks are connected by the connecting member 5 at the solid intermediate deck 4 part, the rigidity against vibration can be increased and the vibration can be reduced.

Then, the water jackets 6a, 6b
The cavitation erosion can be suppressed along with the reduction of the vibration of the inner peripheral portion of the inner portion, and damage to the inner peripheral surface of the water jacket 6 can be prevented. Further, since the rigidity of the jacket outer peripheral wall 8b is increased and the vibration of this portion is suppressed, the vibration of the connecting member 5 connected thereto is also reduced, and the noise generated from these portions can be reduced.

Further, by providing the intermediate deck 4, the deformation of the cylinder bore when the cylinder head is tightened can be reduced by increasing the rigidity of the jacket inner peripheral wall 8a, so that the clearance between the cylinder liner 7 and the piston can be set small. Therefore, the piston slap sound can be reduced. Next, a second embodiment of the present invention will be described with reference to FIGS.

In the second embodiment, a cavity 8 is provided between the intermediate deck 4 and the lower deck 3 of the first embodiment.
And The hollow portion 8 may be a completely closed space, but may have an opening on the outer surface of the cylinder block and be connected to outside air, or may have an opening on the oil pan side, Although it may be connected to the inside of the crankcase, it is formed so that the intermediate deck and the lower deck are connected by thin inner and outer peripheral walls. Preferably, the cavity 8 has an opening 8e in the cylinder-side inner peripheral wall 8a, and the opening 8e is formed so as to be closed by the cylinder liner 7.

With such a configuration, the following effects can be achieved in the second embodiment as well as in the first embodiment. Although it has an opening, since the left and right banks are connected by the connecting member 5 at the solid intermediate deck 4, the rigidity against vibration can be increased, the vibration can be reduced, and the vibration of the cooling water can be reduced. Since it can be reduced, cavitation erosion generated on the inner peripheral surface of the water jacket 6a can be suppressed, and damage to the cylinder block can be prevented.

Further, since the intermediate deck 4 is provided for efficient reinforcement, the rigidity of the cylinder block can be increased without substantially increasing the weight of the engine, and the vibration of this portion can be suppressed. Therefore, the vibration of the connecting member 5 connected thereto can be reduced, and the noise generated from these portions can be reduced. In the second embodiment, as shown in FIGS. 3 and 4, an opening 8 e of the cavity 8 is provided inside the cylinder, and the opening 8 e is formed so as to be closed by the cylinder liner 7. The following effects can be obtained from the viewpoint of strength and production of the cylinder block.

With respect to the rigidity of the cylinder block, the rigidity of the cylinder block is less reduced than in the case where the opening 8e of the cavity 8 is opened on the outer wall of the cylinder block, which is advantageous in strength. Normally, the cylinder block is manufactured by casting, and if there is an isolated cavity, it is difficult to hold the hollow core, so it is connected to another adjacent core, etc., and occurs at the connection portion after casting. It is necessary to remove sand from the hole and then close the hole with a closing plug, which complicates the operation.

In the first embodiment, usually two upper and lower cores are required, and it becomes difficult to maintain the precision of the casting due to an increase in cost with a plug or the like and a decrease in the strength of the core. Also in the second embodiment, from outside the cylinder block,
When supporting the core for the cavity 8, only a small opening is provided in order to maintain the rigidity of the cylinder block. The core itself is thin and has low rigidity, which makes it difficult to cast with high accuracy.
Even if the opening is provided, it is difficult to support the core for the cavity 8 from the small opening in the narrow portion on the crankcase side, and accurate casting cannot be expected. In addition, if the crankcase is left open, oil enters the cavity 8 when the engine is running, and the sand remaining in the cavity 8 may be mixed with the lubricating oil. It is necessary to strictly remove the sand, which complicates the casting operation.

In order to solve these problems, in the second embodiment in which the opening 8e of the cavity 8 is provided inside the cylinder,
As shown in FIG. 9, the hollow portion 8 between the intermediate deck 4 and the lower deck 3 is a part of a space connected to the cylinder core 27 by integrating the lower hollow core 28 with the cylinder core 27 at the opening core 28e. After casting, sanding of the hollow portion 8 can be performed from the opening 8e following the sanding of the cylinder bore.

In addition, since the opening 8e can be closed by the cylinder liner 7, no closing member is required, the cylinder block 1 can be manufactured easily, and oil can be prevented from entering the hollow portion 8. In addition, it is possible to prevent sand remaining during sand removal during casting from being mixed with the lubricating oil. The core 26 for the water jacket shown in FIG.
Are for forming the upper water jacket 6 of the intermediate deck 4, and these cores 26, 27, 28,
28e is connected to the rail 20, and a normal casting operation is performed.

FIG. 5 and FIG. 6 show a third embodiment of the present invention. In the third embodiment, the cavities 8 between the intermediate deck 4 and the lower deck 3 of the second embodiment are not integrated but are dispersedly arranged.
Stealing meat from the inside of the cylinder 9 and opening the opening 8
e is closed by the cinder liner 7.

With such a configuration, the same effects as those of the second embodiment can be obtained in the third embodiment, and the cores 28 for the hollow portions 8 can be replaced with cylinder cores. Since it can be easily formed integrally with 27, the casting operation can be significantly simplified.

[0026]

As described above, according to the first aspect of the present invention, the rigidity of the side wall portion of the water jacket and the connecting portion of the left and right banks is increased by the intermediate deck while keeping the increase in the weight of the engine small. Since the vibrations of these members can be reduced, cavitation erosion on the inner surface of the water jacket can be suppressed to prevent damage, and furthermore, noise generated from these side walls and the connecting members can be reduced.

According to the second aspect of the present invention, the effect of the first aspect of the present invention can be obtained. Further, since the space provided between the intermediate deck and the lower deck is a hollow portion, the efficiency is improved. While cooling the cylinder, the amount of cooling water in the water jacket can be reduced to about half, so the weight during engine maintenance can be reduced and work efficiency can be increased, and the engine can be warmed up quickly when the engine is running .

Further, according to the third aspect of the present invention, the effects of the first and second aspects of the present invention can be obtained, and further, the hollow portion provided between the intermediate deck and the lower deck has a cylinder interior. Since the opening on the side is provided, the mold at the time of casting becomes a simple shape, sanding becomes easy, and further,
Since a closing member for closing the hollow portion is not required, the cylinder block manufacturing process can be simplified, and the working efficiency can be improved.

Accordingly, while minimizing the increase in the weight of the engine, the rigidity of the inner wall of the jacket of the cylinder block is improved and the vibration of the side wall of the jacket is suppressed, thereby preventing damage due to cavitation erosion, reducing noise, and facilitating casting. A lightweight cylinder block of a V-type dry liner engine can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylinder block showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of a cylinder block showing a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a sectional view of a cylinder block showing a third embodiment of the present invention.

6 is a sectional view taken along line AA of FIG.

FIG. 7 is a sectional view of a cylinder block showing a conventional cylinder block structure.

FIG. 8 is a sectional view taken along line AA of FIG. 5;

FIG. 9 is a cross-sectional view of a cylinder block showing a cylinder block structure of a study plan.

FIG. 10 is a sectional view taken along line AA of FIG. 9;

FIG. 11 is an explanatory diagram of a core used when casting a cylinder block according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylinder block 2 ... Top deck 3 ... Lower deck 4 ... Intermediate deck 5 ... Connecting member 5a ... Connecting part 6 ... Water jacket 6a ... Upper water jacket 6b ... Lower water jacket 7 ... Cylinder liner 8a ... Jacket inner peripheral wall 8b ... Jacket outer periphery Wall 8c ... Cylinder side wall 8e ... Opening 9 ... Cylinder 10 ... Crankcase

Claims (3)

[Claims] 1. A cylinder block having a dry liner structure for a V-type engine, wherein an intermediate deck is provided between a top deck and a lower deck of the cylinder block.
Further, a cylinder block of a V-type dry liner engine in which the intermediate deck portions of the left and right banks of the V-type engine are connected by a connecting member. 2. The cylinder block of a V-type dry liner engine according to claim 1, wherein a hollow portion is provided between the intermediate deck and the lower deck. 3. The cylinder block of a V-type dry liner engine according to claim 2, wherein the hollow portion has an opening in an inner peripheral wall on a cylinder side, and the opening is formed to be closed by a cylinder liner.