JPH04103245U - cylinder block of internal combustion engine - Google Patents

Abstract

(57) [Summary] (with amendments) [Structure] The rib 21 connects the cylinder bore wall 2 of each cylinder and the cylinder block outer wall 8 around each cylinder, and the fastening hole 9 and the center axis 23 of each cylinder are connected to each other. The lower end 21b is formed integrally with the closed bottom portion 4, and the upper end 21a is located at approximately the upper end position 12a of the female screw portion 12. [Effect] The rib 21 is a short planar rib, and the lower end 21b is formed integrally with the closed bottom portion 4 and connected to the cylinder block outer wall 8, thereby improving the rigidity. Also, rib
Since the upper end 21a of the head bolt 11 is aligned with the position where the fastening force of the head bolt 11 is large, the fastening force of the head bolt 11 is effectively exerted, and the sealing performance between the cylinder block 1 and the cylinder head is improved. Furthermore, since the upper end 21a is at approximately the middle height of the water jacket 6, the water jacket upper part 6a fully exhibits the cooling effect of the cooling water, promoting equalization of temperature at the upper and lower parts of the cylinder, and thereby reducing friction. Can reduce resistance.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a cylinder block for an internal combustion engine.

0002

[Conventional technology]

Recently, there has been an urgent need to reduce the weight of internal combustion engines, and for this reason, conventional materials such as cast iron are no longer manufactured. Light alloy cylinder blocks have become commonplace in place of conventional cylinder blocks. Ru. By the way, a cylinder block made of light alloy has a lighter weight, but the Young's modulus of the material Since the cylinder block is small, various reinforcements are used to increase the rigidity of the cylinder block. (See Utility Model Application Publication No. 56-71936, etc.).

0003 That is, as shown in FIGS. 7, 8, and 9, at least the cylinder head bolt Cylinder block 60 forming cooling water passage 63 on top deck surface 62 around space part 61 , the cylinder head bolt boss portion 61 on the cylinder block outer wall 64 side and this A rib 67 connecting the boss portion 61 and an inter-bore connecting portion 66 on the opposite cylinder bore wall 65 side is provided. or each cylinder head bolt boss part 61 on the cylinder block outer wall 64 side. By providing a rib 68 that connects the vicinity of the intermediate position and the cylinder bore wall 65, , which increases rigidity.

0004 The cylinder head bolt bosses 61 are arranged at predetermined intervals. By inserting a head bolt (not shown) into the fastening hole 69, the cylinder head can be attached. A cylinder (not shown) is fastened to the top deck surface 62 of the cylinder block 60.

[0005]

[Problem that the idea aims to solve]

By the way, as shown in Figure 10, the cylinder head gasket is attached to the cylinder block 60. (not shown) and when installing the cylinder head 70 and tightening it with the head bolts 71. In addition, the fastening force by the head bolt 71 is large near the head bolt 71, On the other hand, it becomes smaller near the center of the cylinder bore wall 65. Therefore, the cylinder head The surface pressure generated between the bottom surface 72 of the deck 70 and the top deck surface 62 of the cylinder block 60 is It is high near the head bolt 71 and near the center of the cylinder bore wall 65. becomes lower. Furthermore, although the above-mentioned fastening force is generated at the threaded portion, the fastening force is The binding force can be efficiently propagated to the vicinity of the center of the cylinder bore wall 65 via the rib. do not have. Additionally, the fastening force from the head bolt 71 is transmitted to the cylinder bore wall 65. Since the rib 67 connects the boss portion 61 and the farthest inter-bore connecting portion 66, the rib 67 Since the length of 67 is long and it is rod-shaped, it is difficult to sufficiently increase the rigidity.

[0006] Therefore, by providing the ribs 67 and 68 mentioned above, the entire cylinder block 60 is Although the rigidity of the ribs 67 and 68 increases, the fastening force is transmitted through the ribs 67 and 68. Therefore, it is difficult to improve the sealing performance of the cylinder head gasket. Furthermore, when manufacturing cylinder blocks made of aluminum as a light alloy, for example, Since the water jacket is manufactured using a mold, the upper end of the water jacket covers a wide area. It is a so-called open deck type light alloy cylinder block that is open across the entire length. Therefore, the surface pressure of each cylinder head bolt boss on the outer wall of the cylinder block is Since it becomes more difficult to increase the size of the Therefore, no efforts were made to increase the rigidity of the cylinder block.

[0007] This invention was devised in view of the existing circumstances, and was developed to improve the cylinder block. The rigidity has been sufficiently improved so that the fastening force of the head bolt can be effectively exerted. , an internal combustion engine with sufficiently improved sealing between the cylinder block and cylinder head. The purpose is to provide cylinder blocks of.

[0008]

[Means to solve the problem]

For this reason, the present invention provides a bridge between the cylinder bore wall of each cylinder and the outer wall of the cylinder block. The cylinder head has a water jacket and a head bolt inserted through the cylinder head. The external threaded portion of the cylinder block is formed at a position between adjacent cylinders on the outer wall of the cylinder block. The cylinder head can be fastened by screwing into the female thread of the bolt fastening hole. In the cylinder block of an internal combustion engine, The rib connecting the cylinder bore wall and the cylinder block outer wall is connected to the bolt fastening hole. and the central axis of each cylinder, and the lower end of the rib is located on the surface connecting the central axis of each cylinder, and the lower end of the rib It is connected to the bottom wall of the jacket and arranged so that its upper end is located approximately at the upper end of the female threaded portion. Ta.

[0009]

[Effect]

In such a configuration, a rib connecting the cylinder bore wall and the cylinder block outer wall is Located on the plane connecting the head bolt fastening hole and the center axis of each cylinder Therefore, a short rib is extended, and the rigidity of the rib itself increases. Ru.

0010 In addition, since the lower end of the rib is connected to the bottom wall of the water jacket, the rib The cylinder bore wall and cylinder block outer wall are integrated, and the cylinder block This greatly contributes to improving the rigidity of the entire structure. Furthermore, the rib is arranged such that the upper end of the rib is located substantially at the upper end of the female threaded portion. Therefore, the ribs are extended from the fastening part that exerts a greater effect on the fastened member. Therefore, the fastening force is most efficiently transmitted to the rib.

[0011] Therefore, the fastening force is efficiently transmitted to the cylinder bore wall via the ribs, and more The transmitted fastening force equalizes the surface pressure around the cylinder bore. Furthermore, by providing the rib near the bottom wall of the water jacket, Cooling water stagnates near the bottom wall of the water jacket, reducing the amount of heat transfer. As a result, the amount of heat transferred between the cooling water and the cylinder covered by the cylinder bore wall is reduced. This prevents the temperature below the cylinder bore from dropping too much.

0012

【Example】

Hereinafter, embodiments of the present invention will be described based on the drawings. The embodiment shown in FIGS. 1 and 2 is an aluminum alloy cylinder block 1, in which iron liners 3 are cast or inserted into cylinder bore walls 2 (hereinafter the center line is indicated by _C2 ) arranged at predetermined intervals L. It is a dry liner type cylinder with four cylinder bore walls 2 connected to each other. It also has a cylinder block outer wall 8 that forms a water jacket 6 having a closed bottom 4 between the cylinder bore wall 2 and the cylinder bore wall 2, and the upper end of the water jacket 6 is open over a wide range. It has a so-called open deck type water jacket structure. A boss 10 having a bolt fastening hole 9 is formed in the cylinder block outer wall 8 at a position between adjacent cylinders and at the side end of each of the #1 and #4 cylinders, and is inserted into a cylinder head (not shown). The cylinder head is fastened to the top deck 13 of the cylinder block 1 by screwing the male threaded part of the head bolt 11 into the female threaded part 12 formed in the fastening hole 9.

[0013] In addition, the cylinder block 1 is equipped with oil that supplies lubricating oil to the crankshaft 14. Lubricating oil to the passage 15 and the valve mechanism (not shown) provided in the cylinder head. An oil drop passage 16 is provided for the oil to return to the oil pan (not shown). , the oil drop passage 16, etc. has a boss portion 17 protruding from the outer surface 8a of the cylinder block outer wall 8. It is formed as follows.

[0014] Here, as a configuration according to the present invention, the cylinder bore wall 2 of each cylinder and the surrounding area of each cylinder are The rib 21 connecting the outer wall 8 of the cylinder block is inserted between the fastening hole 9 and the center of each cylinder. It is provided so as to be located on a surface 24 connecting with the shaft 23. Further, the fastening hole 9 has an enlarged diameter portion 26 whose diameter is slightly larger than the diameter φd of the head bolt 11. (diameter φD, where d<D) and a male thread formed at the tip of the head bolt 11. The lower end 21b of the rib 21 is connected to the closed bottom. 4, and the upper end 21a is located at approximately the upper end position 12a of the female threaded portion 12.

[0015] Next, the effect will be explained. The rib 21 is provided so as to be located on a surface 24 connecting the fastening hole 9 and the central axis 23 of each cylinder. Therefore, the rib 21 is provided perpendicularly to the cylinder bore wall 2 of each cylinder. That will happen. Therefore, the distance between the cylinder bore wall 2 and the cylinder block outer wall 8 is short. The rib 21 will be provided at a different position, and the rib 21 will be short. 21 is a rib with high rigidity. Further, in this embodiment, the fastening hole 9 Since the boss 10 is located between the cylinders, the cylinder bore wall 2 and the cylinder The distance from the double block outer wall 8 is shorter, and the rib 21 has higher rigidity. It becomes possible to provide

[0016] Further, the lower end 21b of the rib 21 is formed integrally with the closed bottom portion 4 of the water jacket 6. By doing so, the cylinder bore wall 2, the rib 21, and the cylinder block outer wall 8 are connected. The rib 21 is a surface, which greatly improves the rigidity of the entire cylinder block 1. contributes to Therefore, according to the configuration according to this embodiment, the cylinder block outer wall 8 and the cylinder Rigidity can be increased without increasing the thickness of A-wall 2, etc., resulting in increased weight. Furthermore, rigidity can be increased while suppressing cost increases.

[0017] Next, we will discuss the construction in which the upper end 21a of the rib 21 is set at approximately the upper end position 12a of the female threaded portion 12. Explain the purpose. Figure 3 shows the fastening force for each fastening point of a typical bolt. As shown, compared to the tip 52 of the bolt 51, the location is closer to the source, which is the direction in which the load is applied. 53 has a higher load sharing ratio f, which exerts a greater effect on the fastened members. It is something. Therefore, the head bolt 11 is inserted into the fastening hole 9, and the cylinder block is Connect the cylinder head (not shown) to the cylinder head gasket (not shown) etc. The tightening force by the head bolt 11 is generated at the female threaded portion 12 when tightening the As described above, the approximately upper end position 12a of the female threaded portion 12 becomes the largest. .

[0018] Here, the rib 21 is provided on the surface including the female threaded portion 12, and the rib 21 By setting the upper end 21a at approximately the upper end position 12a of the female threaded portion 12, the head bolt The fastening force acting on the boss 10 provided on the cylinder block outer wall 8 due to the It is efficiently transmitted to the rib 21 and transmitted to the cylinder bore wall 2 via the rib 21. That will happen. That is, the heads shown in FIG. 4 with and without ribs 21 It is clear from the measurement results of grommet surface pressure P, which corresponds to the fastening force by bolt 11. Of course, the measurement points located on the surface 24 (point b, point d, point f, point h), The surface pressure P has also improved at other measurement points, and the tightening force of the head bolt 11 has increased. The seal between the cylinder block 1 and the cylinder head has become more effective. The flexibility has been sufficiently improved.

[0019] By the way, in each cylinder, the temperature of the cylinder bore wall upper part 2a near the combustion chamber is Although the temperature is higher than that of the lower part 2b of the cylinder bore wall, the temperature of the upper part 2a of the cylinder bore wall is higher than that of the lower part 2b of the cylinder bore wall. When cooling with cooling water based on the temperature, the temperature difference causes the underside of the cylinder bore wall. The temperature of the portion 2b becomes too low, and the frictional resistance with the piston (not shown) becomes large. The loss will become large.

[0020] In this embodiment, the lower end 21b of the rib 21 is connected to the closed bottom 4 of the water jacket 6. is formed integrally with the water jacket 6, and its upper end 21a is located at approximately the middle height of the water jacket 6. As shown in FIG. a is the position below the piston lower end 31b when the piston 31 is located at the top dead center. ing.

[0021] Therefore, the flow rate of the cooling water flowing through the water jacket 6 is near the top deck 13. In the upper part 6a of the water jacket, there is a rib 21 that acts as a resistance to the flow. On the other hand, at the lower part 6b of the water jacket, The presence of ribs 21 that act as resistance slows down the process. Water jacket upper part 6a The cooling water flows evenly in the vicinity, and the area is covered by the cooling water and the cylinder bore wall 2. The heat exchange with the piston 31 is performed efficiently, and the cooling effect of the cooling water is fully demonstrated. As a result, the piston 31 and the cylinder bore wall upper part 2a are sufficiently cooled. On the other hand, The cooling water will stagnate near the lower part of the water jacket 6b, causing the cooling water and the cylinder cylinder to stagnate. The amount of heat transferred to the piston 31 covered by the a wall 2 is reduced, and cooling by the cooling water The effect is reduced, and the temperature of the lower part 2b of the cylinder bore wall does not drop too much. . Therefore, as shown in FIG. 6, the upper part of the cylinder bore wall 2a, which is the upper part of the cylinder, and the lower part of the cylinder This promotes equalization of temperature with the cylinder bore wall lower part 2b, which suppresses thermal deformation of the cylinder. Even if the clearance between the piston 31 and the cylinder bore wall 2 is reduced, the frictional resistance is It is possible to prevent losses from increasing without increasing resistance.

[0022] Furthermore, in this embodiment, the closed bottom portion 4 of the water jacket 6 is connected to the piston. 31, but it is located at the bottom of the top land 32 installed on the piston 31. The temperature rises the highest up to the bottom of the top land 32, which is attached to the top. , even if the piston 31 is at the bottom dead center, the piston 31 is always cooled by the cooling water. Therefore, cooling is performed and seizure resistance is ensured.

[0023] Furthermore, the so-called siyamise portion 35 adjacent to the cylinder bore wall 2 is cooled by cooling water. Although the cooling effect is difficult to act and the temperature easily rises, in this example, the siyamise part 35's water jacket lower part 6c is further lowered, so the cooling range is widened. By increasing the cooling effect, it is possible to equalize the temperature distribution and improve seizure resistance.

[0024]

[Effect of the idea]

As explained above, according to the present invention, the cylinder bore wall and the outside of the cylinder block The rib connecting the wall is positioned on the plane connecting the bolt fastening hole and the central axis of each cylinder. and the lower end of the rib is connected to the bottom wall of the water jacket, and the upper end is connected to the bottom wall of the water jacket. Since it is located almost at the upper end of the threaded part, the rigidity of the rib itself and the cylinder bush are The rigidity of the entire lock is greatly improved. Therefore, the tightening force of the head bolt is more efficient. is transmitted to the entire cylinder block, and is efficiently transmitted to the top deck of the cylinder block. As a result, the surface pressure around the cylinder bore is uniform due to the transmitted fastening force. The tightening force of the head bolt can now be effectively exerted, and the cylinder blow The sealing performance between the cylinder head and the cylinder head is sufficiently improved.

[0025] Furthermore, by providing the ribs near the bottom wall of the water jacket, the air This promotes equalization of temperature between the upper and lower parts of the cylinder, suppresses thermal deformation of the cylinder, and reduces friction. It becomes possible to reduce losses.

[Brief explanation of drawings]

[Fig. 1] A plan view of a cylinder block of an internal combustion engine according to the present invention.

[Figure 2] A-A sectional view in Figure 1

[Figure 3] Diagram showing the fastening force for each bolt fastening location

[Fig. 4] A diagram showing the measurement results of grommet surface pressure P to explain the action of the present invention.

[Fig. 5] Arrow view when a part of the cylinder block outer wall is removed as seen from direction B in Fig. 1

[Fig. 6] A diagram showing the temperature of the cylinder bore wall of a cylinder to explain the action of the present invention.

[Fig. 7] Partial plan view of a cylinder block of an internal combustion engine showing a conventional example

[Figure 8] FF sectional view in Figure 7

[Figure 9] GG sectional view in Figure 7

[Figure 10] Action diagram to explain conventional issues

[Explanation of symbols]

1 cylinder block 2 Cylinder bore wall 4 Closed bottom 6 Water jacket 8 Cylinder block outer wall 9 Fastening hole 10 boss 11 head bolt 12 Female thread part 13 Top Deck 21 ribs 21a Upper end 21b Bottom end 23 Center of cylinder 35 Saiyamiz Club

Claims (1)

[Scope of utility model registration request] Claim 1: A water jacket is provided between the cylinder bore wall of each cylinder and the outer wall of the cylinder block, and
An internal combustion engine in which a cylinder head is fastened by screwing a male threaded part of a head bolt inserted into the cylinder head into a female threaded part of a bolt fastening hole formed at a position between adjacent cylinders on the outer wall of the cylinder block. In the cylinder block, a rib connecting the cylinder bore wall and the cylinder block outer wall is located on a plane connecting the bolt fastening hole and the central axis of each cylinder, and the lower end of the rib is connected to the bottom wall of the water jacket. A cylinder block for an internal combustion engine, wherein the cylinder block is arranged such that the upper end thereof is located substantially at the upper end of the female threaded portion.