JP2015004333A - Cylinder block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder block capable of achieving cooling more effectively.SOLUTION: A cylinder block 10 has a block W/J12 sectioned by a spacer 13 into two water channel areas in a bore height direction, and two holes 22, 23 which are open upward in the block and have ends connected to each other are bored in their inter-bore parts, and serve as inter-bore cooling water channels for supplying cooling water to the inter-bore parts.

Description

  The present invention relates to a cylinder block of a water-cooled engine, and more particularly to improvement of a water channel structure for cooling the cylinder block.

  A water jacket is provided around the bore of a cylinder block of a water-cooled engine. The engine is cooled by circulating cooling water through the water jacket.

  Conventionally, as seen in, for example, Patent Document 1, the water jacket is separated into two water channel regions by the spacer installed in the water jacket, that is, the upper water channel region above the spacer (cylinder head side) and the lower side of the spacer (crank A cylinder block partitioned into a lower water channel region on the case side) is known. In such a cylinder block, by restricting the amount of cooling water flowing through the lower water channel region, a larger amount of cooling water can flow through the upper water channel region and the cylinder head. Thus, it is possible to more effectively cool the portion in the vicinity of the combustion chamber where the temperature tends to be particularly high.

JP 2002-303137 A

  By the way, in a cylinder block of a multi-cylinder engine, a small-diameter hole is drilled in a portion between two adjacent bores (hereinafter referred to as “bore portion”) by drilling, and the hole is formed in the portion between the bores. There is a water channel for cooling. This water channel is generally called a drill path.

  As shown in FIG. 6, the drill path 50 is usually formed so as to pass from the deck surface 52 of the cylinder block 51 to a water jacket (hereinafter referred to as “block W / J53”) of the cylinder block 51. Then, the opening of the drill path 50 in the deck surface 52 is connected to a water jacket (hereinafter referred to as “head W / J55”) of the cylinder head 54 so that the cooling water flows through the drill path 50 to the portion between the bores. It is supposed to be.

  When the cylinder block 51 having such a drill path 50 adopts the upper and lower sections of the block W / J53 as described above, the section position of the block W / J53 is lower than the opening of the drill path 50 on the block W / J53 side. Will have to. If the drill path 50 is opened below the partition position, the upper water channel region 56 and the lower water channel region 57 of the block W / J 53 partitioned by the spacer 58 through the drill path 50 and the head W / J 55 This is because of communication.

  On the other hand, the drill path 50 cannot make the angle with respect to the deck surface 52 too shallow due to processing limitations. Therefore, as shown in FIG. 7, if the position of the opening of the drill path 50 to the block W / J53 is increased, the drill path 50 cannot pass through the portion S that needs the most cooling. Therefore, in the cylinder block 51 having the drill path 50, the partition position of the block W / J53 must be lowered. In such a case, the lower water channel region 57 of the block W / J 53 becomes narrow, and even if the flow rate of the cooling water is limited, the flow rate of the cooling water in the upper water channel region 56 cannot be increased too much. The effect of improving the cooling efficiency due to this section is limited.

  The present invention has been made in view of such circumstances, and a problem to be solved is to provide a cylinder block capable of performing cooling more effectively.

  A cylinder block that solves the above-described problems is a cylinder block in which water jackets partitioned in the bore height direction are provided on both sides of the bore row, and adjacent to each other, two holes that are opened and connected to each other above the block. Provided in the part between the two bores, and when the end on the side opened above the block is the start end and the opposite end is the end, the end of each hole is a closed end, or One of them is connected to one hole.

  In the cylinder block configured as described above, the portion between the bores of the cylinder block is cooled by flowing cooling water through two holes connected to each other. The ends of these two holes are either closed or connected to the other hole, and neither hole communicates with the water jacket. For this reason, even if the partition position of the water jacket in the bore height direction is increased, the two water channel regions formed by the partition are not communicated with each other. Therefore, the partition position of the water jacket is not limited by the cooling water channel in the portion between the bores, and the setting of the partition position where high cooling efficiency can be obtained is allowed even in the cylinder block having such a water channel. Therefore, according to such a cylinder block, it becomes possible to perform cooling more effectively.

The top view which shows partially the planar structure of the block top surface about one Embodiment of a cylinder block. The figure which shows typically the cooling water channel structure of the cylinder block of the same embodiment, and the cylinder head attached to the cylinder block. Sectional drawing which shows the cross-section of the cylinder head attached to the upper part of the cylinder block of the same embodiment and its cylinder block along the AA line of FIG. Sectional drawing which shows the cross-section of the part between the bores of the cylinder block in the modification of the embodiment. Sectional drawing which shows the cross-section of the part between the bores of the cylinder block in another modification of the embodiment. Sectional drawing which shows the sectional structure of the part between the bores of the conventional cylinder block and the cylinder head attached to the conventional cylinder block which has the division structure of a water jacket, and the cooling water path between boss | hubs, and its cylinder block. Sectional drawing which shows the cross-section of the part between bores when the division position of block W / J is changed upwards in the conventional cylinder block.

Hereinafter, an embodiment of a cylinder block will be described in detail with reference to FIGS. The cylinder block of this embodiment is used for a water-cooled multi-cylinder engine.
In the following description, the extending direction of the bore of the cylinder block is referred to as “bore height direction”, and the direction orthogonal to the bore arrangement direction on the block top surface of the cylinder block is referred to as “block left-right direction”. In the following description, the cylinder head side in the bore height direction of the cylinder block is the upper side of the cylinder block, and the crankcase side is the lower side of the cylinder block.

  As shown in FIG. 1, the cylinder block 10 is provided with a plurality of cylindrical bores 11 (two of which are shown in the figure) arranged in series. A water jacket (hereinafter referred to as “block W / J12”) through which cooling water is circulated is formed around the bore row.

  As shown in FIG. 2, the block W / J 12 has two water channel regions in the height direction of the bore 11, that is, an upper water channel region 14 on the upper side of the spacer 13 and a lower part of the spacer 13 by a spacer 13 installed in the block W / J 12. It is partitioned into a lower water channel region 15 on the side. The spacer 13 is installed by being inserted from the opening of the block W / J 12 in the deck surface 17 of the cylinder block 10 and pushed into a predetermined position.

  On the other hand, a cylinder head 18 is attached to the deck surface 17 of the cylinder block 10 via a head gasket 16. The upper water channel region 14 of the block W / J 12 communicates with a water jacket (hereinafter referred to as “head W / J 19”) of the cylinder head 18.

  Cooling water is introduced into the upper water channel region 14 and the lower water channel region 15 of the block W / J 12 through the cooling water supply pipe 20. The cooling water supply pipe 20 is provided with a switching valve 21 for switching between supply and stop of the cooling water to the lower water channel region 15.

  The cylinder block 10 is provided with an inter-bore cooling channel for flowing cooling water for cooling the portion between the bores in a portion between the two adjacent bores 11 (hereinafter referred to as “portion between the bores”). It has been. The details of the interbore cooling water channel will be described below.

  As shown in FIG. 3, two holes 22 and 23 having a circular cross section are provided in the portion between the bores of the cylinder block 10 so as to open above the block. In the following description, the ends of the holes 22 and 23 that are opened above the block are referred to as “start ends”, and the opposite ends are referred to as “end ends”.

  These holes 22 and 23 are drilled in a straight line from the deck surface 17 in an oblique direction with respect to the deck surface 17 by drilling. And these two holes 22 and 23 are mutually connected in each terminal. Further, these holes 22 and 23 are connected to the head W / J 19 on the start end side.

Next, the operation of the cylinder block 10 of the present embodiment configured as described above will be described.
In the cylinder block 10 of this embodiment, a part of the cooling water of the head W / J 19 flows through the holes 22 and 23 formed in the portion between the bores of the cylinder block 10, and the portion between the bores is cooled by the cooling water. Will come to be. That is, in the cylinder block 10, an inter-bore cooling water channel (drill path) for cooling the portion between the bores is formed by the two holes 22 and 23.

  On the other hand, in the engine provided with the cylinder block 10 of the present embodiment, when the temperature around the combustion chamber becomes high, such as during high-speed operation, the switching valve 21 is closed and the cooling water to the lower water channel region 15 is closed. Is stopped. At this time, the cooling water is sent to the upper water channel region 14 until it has been turned to the lower water channel region 15 until then. As a result, the cooling water is concentrated on the upper water channel region 14 of the block W / J 12 positioned around the combustion chamber and the head W / J 19 communicated therewith, and the cooling performance around the combustion chamber is improved.

  In addition, the improvement of the cooling performance around the combustion chamber by the concentration of the cooling water can be effectively performed as the difference in the cooling water flow rate in the upper water channel region 14 between the normal time and the time of the concentrated cooling is larger. And in order to ensure the flow volume difference, it is necessary to make the flow path area of the lower channel area 15 of the block W / J12 sufficiently wide.

  However, as described above, if the cooling water channel between the bores communicates with the block W / J12, the partition position of the block W / J12 in the bore height direction (installation position of the spacer 13) is the bore with respect to the block W / J12. It can be set only at a position lower than the opening of the intercooling water channel. Therefore, in such a case, the flow area of the lower water channel region 15 cannot be made sufficiently large.

  In that respect, in the cylinder block 10 of the present embodiment, since neither of the two holes 22 and 23 constituting the inter-bore cooling water channel is communicated with the block W / J12, the block W / J12 has such a position. There is no restriction imposed by the opening position of the cooling water channel between the bores. Therefore, in the cylinder block 10, the partition position of the block W / J12 can be increased, and the cooling water can be more effectively concentrated around the combustion chamber.

According to the cylinder block 10 of this embodiment demonstrated above, there can exist the following effects.
(1) In this embodiment, since neither of the two holes 22 and 23 constituting the inter-bore cooling water channel is communicated with the block W / J12, the bore height is provided even if the inter-bore cooling water channel is provided. The partition position of the block W / J12 in the direction can be increased. As a result, the flow area of the lower water channel region 15 of the block W / J 12 can be increased, and the cooling water can be more effectively concentrated during the central cooling around the combustion chamber. Therefore, according to the cylinder block of this embodiment, cooling can be performed more effectively.

  (2) Since the two bores 22 and 23 extending linearly from above the block are connected to form an inter-bore cooling water channel, an inter-bore cooling water channel that does not communicate with the block W / J 12 is provided without using special processing. It is possible to perform the processing for the formation easily and inexpensively.

In addition, the said embodiment can also be changed and implemented as follows.
In the above embodiment, the holes 22 and 23 are formed by drilling, but the holes 22 and 23 may be formed by other processing methods such as laser processing.

  As shown in FIG. 4, one of the holes 22 and 23 (hole 22 in the figure) extends beyond the connecting portion with the other hole, or both holes 22 as shown in FIG. 5. , 23 may be extended beyond their connecting portions. Even in such a case, if the end of the extended hole is set as a closed end so as not to communicate with the block W / J12, the partition position of the block W / J12 is set to an appropriate position where effective cooling performance can be obtained. It becomes possible.

  In the above embodiment, the holes 22 and 23 are formed so as to open in the deck surface 17, but they may be formed so as to open in the upper end portion of the block W / J 12. In such a case, the holes 22 and 23 are opened above the block through the opening of the block W / J 12 on the deck surface 17. Incidentally, “opening above the block” of the holes 22 and 23 in the present invention means that the holes 22 and 23 are formed by drilling from above the block.

  In the above embodiment, the switching valve 21 switches between supply and stop of the cooling water to the lower water channel region 15. A flow rate adjustment valve may be provided in place of the switching valve 21, and the flow rate of the cooling water in the lower water channel region 15 may be adjusted according to the operating condition of the engine.

  In the above embodiment, the supply state of the cooling water to the lower water channel region 15 is controlled according to the operating state of the engine. However, the partition structure of the block W / J12 may be adopted for purposes other than such control. is there. For example, the block W / J12 is divided into two water channel regions in the bore height direction, and the bore water height is always increased by causing the cooling water flow rate in the upper water channel region near the combustion chamber to be larger than that in the lower water channel region. The temperature gradient of the bore wall surface in the direction may be smoothed. Even in such a case, if the cooling water channel between the bores is formed by the two holes 22 and 23 as described above, it becomes possible to set the partition position of the block W / J12 more freely and to perform more effective engine cooling. become.

  DESCRIPTION OF SYMBOLS 10 ... Cylinder block, 11 ... Bore, 12 ... Block W / J (water jacket), 13 ... Spacer, 14 ... Upper channel area, 15 ... Lower channel area, 16 ... Head gasket, 17 ... Deck surface, 18 ... Cylinder head , 19... Head W / J, 20. Cooling water supply pipe, 21... Switching valve, 22, 23.

Claims (1)

In the cylinder block in which the water jacket defined in the bore height direction is provided around the bore row,
Two holes opened above the block and connected to each other are provided in the part between two adjacent bores, and the end on the side opened above the block is the starting end and the opposite end is terminated The cylinder block is characterized in that the end of each hole is either a closed end or connected to the other hole.