JP6225971B2 - Cylinder body structure of multi-cylinder engine - Google Patents

Description

  The present invention relates to a cylinder body structure of a multi-cylinder engine.

  Conventionally, as a cylinder main body structure of a multi-cylinder engine, a structure in which a plurality of cylinder liners are cast with a metal such as an aluminum alloy, and a cooling water passage through which cooling water flows is formed in a wall portion between cylinder bores of the cylinder liner. Are known. For example, Patent Document 1 discloses a cylinder body structure having a drill passage hole as a cooling water channel provided in a wall portion between cylinder bores between adjacent cylinder liners and communicating with a water jacket, and the drill passage hole includes: From the upper surface of the wall portion between the cylinder bores, the approaching portion where the cylinder liners in the wall portion are closest to each other passes obliquely with respect to the axial direction of the cylinder liner and communicates with the water jacket at the lower end portion. A cylinder body structure is disclosed in which a groove portion is formed on the outer peripheral surface of each cylinder liner so as to increase a distance from the drill passage hole in a portion corresponding to the approaching portion.

Japanese Patent No. 4378863

  By the way, in order to improve the adhesiveness with the aluminum alloy etc. which casts a cylinder liner, the outer peripheral surface of a cylinder liner may be provided with the contact | adherence process which forms many convex parts. On the other hand, when forming a groove part on the outer peripheral surface of a cylinder like the cylinder of patent document 1, the said convex part is not formed in a groove part also in order to expand a space | interval with a drill passage hole. Therefore, when such close contact processing is applied to the cylinder liner, in order to improve cast adhesiveness of the cylinder liner, the close contact processing is performed with the region where the groove is formed as small as possible. It is desirable not to reduce the area that is present as much as possible.

  In the cylinder described in Patent Document 1, a drill passage hole serving as a cooling water passage passes obliquely with respect to the axial direction of the cylinder liner from the upper surface of the wall portion between the cylinder bores, and the lower end of the drill passage hole. Since the portion is formed so as to communicate with the water jacket, if the drill passage hole is formed over the entire width direction of the cylinder block, the axial length of the cylinder liner in the drill passage hole becomes relatively long. . As a result, it is necessary to increase the size in the axial direction of the groove formed in the cylinder liner by the length that the drill passage hole passes, and the cylinder liner adheres to the groove formed thereby. The processing area may be reduced, and the casting adhesion of the cylinder liner may be reduced.

  In addition, when the drill passage hole becomes long, the rotational blur of the drill during processing becomes large. Therefore, the interval between the grooves must be increased in consideration of the rotational blur.

  The present invention has been made in view of such a point, and an object of the present invention is to facilitate the processing when the space between the bores of the cylinder liner is narrowed and to improve the casting adhesion of the cylinder liner. There is.

  In order to solve the above problems, a cylinder body structure of a multi-cylinder engine according to the present invention includes a cylinder block having a plurality of cylinder liners that are formed by casting a cylinder bore, a cylinder head attached to the cylinder block, and A cylinder body structure of a multi-cylinder engine provided with a crank chamber formed on the side opposite to the cylinder head in the cylinder block, and provided on the wall portion between adjacent cylinder bores in the cylinder block, A first machining hole formed to be inclined from the surface on the cylinder head side toward the crank chamber side in the width direction of the cylinder block, and the wall portion on which the first machining hole is formed. On the surface on the cylinder head side, from a position different from the first processing hole in the width direction, Inclined toward the crank chamber side in the width direction opposite to the first processing hole so that the end portion on the rank chamber side merges with the end portion on the crank chamber side of the first processing hole. Each of the second processing holes formed is provided with a V-shaped water channel formed by a cross-section, and an outer peripheral surface of the cylinder liner is provided to widen a space between the first processing hole and the second processing hole. A groove portion is formed, and a joining portion where an end portion on the crank chamber side of the first processing hole and an end portion on the crank chamber side of the second processing hole join each other in the width direction of the cylinder block, A configuration in which the cylinder liners in the wall are closest to each other and are formed in the vicinity of the closest approach, and are formed at positions overlapping with the grooves in the axial direction of the cylinder liner; did.

  According to this configuration, the water channel is not formed in a straight line inclined from the surface on the cylinder head side of the wall portion between the cylinder bores toward the crank chamber side, but from different positions in the width direction of the cylinder block, The ends on the crank chamber side are formed so as to approach each other.

  Specifically, the first wall is formed to be inclined toward the crank chamber side from the surface of the wall portion on the cylinder head side toward the cylinder block width direction (hereinafter sometimes simply referred to as “block width direction”). From the position where the machining hole and the first machining hole on the cylinder head side surface of the wall portion differ in the block width direction, the crank chamber side toward the block width direction opposite to the first machining hole A water channel is formed by the second processed hole formed so as to be inclined. Therefore, even when a water channel is formed over the entire width direction of the cylinder block, as in the conventional case, the wall is inclined in a straight line from the cylinder head side surface toward the crank chamber side. In comparison with the above, the length of the cylinder liner in the axial direction from the surface on the cylinder head side of the wall portion (hereinafter sometimes simply referred to as “liner axial direction”) is about half. Therefore, the influence of the processing blur at the time of processing becomes smaller than before, and the water channel can be easily formed.

  The joining portion where the crank chamber side end of the first machining hole and the crank chamber side end of the second machining hole join is the cylinder liner in the wall in the width direction of the cylinder block. It is formed in the closest part and the vicinity of the closest part that are closest to each other, and is formed at a position that overlaps the groove part in the axial direction of the cylinder liner.

  That is, the size of the groove portion in the liner axial direction needs to be increased by the length in the liner axis direction in the vicinity of the machining hole and in the vicinity of the closest portion. In the direction, the cylinder liners in the wall portion are formed in the closest approach portion and the vicinity of the closest approach portion, and in the liner axial direction, if formed in a position overlapping the groove portion, Only the end of the first machining hole on the crank chamber side and the end of the second machining hole on the crank chamber side pass through the closest part and the vicinity of the closest part, Since the length in the liner axial direction of the machining hole passing through the vicinity near the closest part and the vicinity of the closest part is shortened, the size of the groove part in the liner axial direction can be reduced. As a result, it is possible to reduce the decrease in the contact processing area on the outer peripheral surface of the cylinder liner due to the formation of the groove, and it is possible to improve the casting adhesion of the cylinder liner.

  In one embodiment of the cylinder main body structure of the multi-cylinder engine, the merging portion is formed at a position closer to the crank chamber side than the central position in the axial direction of the cylinder liner in the groove portion.

  That is, if the junction is formed at a position closer to the crank chamber than the axial position of the cylinder liner in the groove, the depth of the water channel is maximized while reducing the width of the groove in the liner axial direction as much as possible. Therefore, cooling of the cylinder bore by the water channel can be efficiently performed while improving the casting adhesion of the cylinder liner.

  In the cylinder body structure of the multi-cylinder engine, a cylinder block side water jacket provided around the cylinder bore in the cylinder block and through which cooling water flows, and a cylinder head side water provided in the cylinder head and through which cooling water flows. The cylinder block-side water jacket, and the cylinder block-side water jacket is configured such that after the cooling water has circulated through the upstream-side water flow channel which is a water channel on one side in the width direction of the cylinder block in the cylinder block-side water jacket, The block-side water jacket is configured to flow through a downstream flow channel that is the other channel in the width direction of the cylinder block in the block-side water jacket, and the cylinder head-side water jacket is cooled after flowing through the downstream flow channel. Configured to flow in The first processing hole is formed at a position near the downstream flow channel in the width direction of the cylinder block of the wall portion, communicates with the cylinder head side water jacket, and The processing hole is formed at a position near the upstream flow channel in the width direction of the cylinder block of the wall portion, communicates with the water jacket, and the cylinder head side water jacket includes the second hole. It is desirable that the cooling water that has flowed into the first processing hole further flows through the processing hole and the merging portion.

  According to this configuration, the cooling water flows into the water channel through the second processing hole communicated with the cylinder block-side water jacket, passes through the junction, and passes through the first machining hole communicated with the cylinder head-side water jacket. Through the waterway.

  That is, in general, the cooling water first flows into the cylinder block side water jacket, flows through the cylinder block side water jacket, and then flows into the cylinder head side cylinder head. The pressure of the cooling water flowing through the cylinder block side water jacket is higher than the pressure of. For this reason, if the second machining hole is configured to communicate with the cylinder block-side water jacket, while the first machining hole is configured to communicate with the cylinder head-side water jacket, the second machining hole is configured to be in contact with the pressure on the first machining hole side. The pressure on the machining hole side becomes higher, and the cooling water flows in from the second machining hole side having a relatively high pressure and flows out from the first machining hole side having a relatively low pressure. As a result, the cooling water can easily pass through the water channel in the width direction of the cylinder block, and the cooling efficiency of the cylinder bore using the water channel can be improved.

  Moreover, since the 2nd process hole is formed in the position near the upstream flow path in the wall part between cylinder bores, a cooling water flows in into a 2nd process hole from an upstream flow path. In general, the upstream flow channel has a higher pressure than the downstream flow channel, so that the cooling water easily flows into the second machining hole. As a result, the cooling efficiency of the cylinder bore can be improved.

  In the cylinder body structure of the multi-cylinder engine, the cylinder head includes an intake port and an exhaust port, and the intake port is provided with the first machining hole of the cylinder block in the width direction of the cylinder head. It is desirable that the exhaust port is disposed on the same side as the side where the second machining hole of the cylinder block is disposed in the width direction of the cylinder head.

  According to this configuration, since the exhaust port is arranged on the same side as the side where the second machining hole of the cylinder block is arranged in the width direction of the cylinder head, the exhaust port is arranged on the upstream flow channel side. It becomes like this. That is, the side of the cylinder bore whose temperature is likely to rise due to the exhaust heat is positioned on the upstream flow channel side where the flow of the cooling water is intense, so that the cylinder bore can be efficiently cooled by the cooling water.

  As described above, according to the cylinder body structure of the multi-cylinder engine of the present invention, the length from the cylinder head side surface of the wall portion in the machining hole can be reduced compared to the conventional case. In this case, there is less blurring and a water channel can be easily formed. In addition, since the size of the groove portion formed on the outer peripheral surface of the cylinder liner in the liner axial direction can be made as small as possible, the formation of the groove portion reduces the adhesion treatment area on the outer peripheral surface of the cylinder liner. Can be reduced as much as possible. As a result, the casting adhesion of the cylinder liner can be improved.

It is sectional drawing which shows schematic structure of the engine provided with the cylinder main body structure of the multicylinder engine which concerns on embodiment of this invention. It is a top view of a cylinder block. It is a top view of the gasket attached to the upper part of a cylinder block. It is sectional drawing of the engine which attached the gasket and cylinder head cut | disconnected in the location equivalent to the IV-IV line | wire of FIG. It is a side view of the cylinder liner used for a cylinder block. It is sectional drawing equivalent to the VI-VI line of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a multi-cylinder engine 2 (hereinafter referred to as engine 2). The engine 2 is an in-line four-cylinder gasoline engine in which first to fourth cylinders are sequentially arranged in series in a direction perpendicular to the paper surface of FIG. 1, and is mounted on a vehicle such as an automobile. In the following description, for convenience of explanation, with the engine 2 mounted on the vehicle, the axial direction of the cylinder liner 51 is referred to as the vertical direction, the cylinder row direction is referred to as the left-right direction of the vehicle, and is orthogonal to the cylinder row direction. The direction to do is called the block width direction. In the axial direction of the cylinder liner 51, the cylinder head 3 side is referred to as the upper side, and the crank chamber 5a side is referred to as the lower side. Further, a transmission (not shown) is disposed on the right side of the engine 2, and in the cylinder row direction, the non-transmission side of the engine 2 is referred to as the left side, and the transmission side of the engine 2 is referred to as the right side of the vehicle.

  In the engine 2, a cylinder head 3, a gasket 4, a cylinder block 5, and a crankcase 6 that form a cylinder body 1 are connected vertically, and an oil pan 7 is attached to the lower surface of the crankcase 6.

  The cylinder block 5 is a liner cast aluminum block in which four cylinder liners 51 are cast with an aluminum alloy using a mold. Cylinder liners 51 are respectively arranged at the upper part of the cylinder block 5, and the lower part of the cylinder block 5 forms a crank chamber 5 a together with the crankcase 6.

  In the cylinder block 5, the cylinder liners 51 are arranged side by side in the cylinder row direction, whereby four cylinder bores 53 corresponding to the four cylinders are formed side by side in the cylinder row direction (see FIG. 2). The cylinder bore 53 is provided with a piston 9 that can slide the cylinder bore 53. The piston 9 and the crankshaft 10 rotatably supported by the crankcase 6 in the crank chamber 5 a are connected by a connecting rod 11. Has been. In addition, the combustion chamber 12 is partitioned for each cylinder by the cylinder bore 53 of the cylinder block 5, the piston 9, and the cylinder head 3. The four cylinder bores 53 correspond to a first cylinder, a second cylinder, a third cylinder, and a fourth cylinder in order from the left side.

  Since the cylinder liner 51 in the cylinder block 5 is cast with an aluminum alloy, the outer peripheral surface of the cylinder liner 51 is covered with an aluminum wall 54 (wall portion). Inside the aluminum wall 54, a cylinder block side water jacket (hereinafter referred to as “block side WJ”) 55 through which cooling water for cooling the cylinder bore 53 circulates surrounds the cylinder liner 51, that is, the cylinder bore 53. It is formed around.

  A gasket 4 provided with a bore communication hole 44 (see FIG. 3) corresponding to each cylinder bore 53 is attached to the upper surface of the cylinder block 5 (ie, the surface on the cylinder head side). Further, the cylinder head 3 is attached to the upper surface of the gasket 4.

  The cylinder head 3 is provided with an intake port 13 and an exhaust port 14 that open to the combustion chamber 12 so as to extend in the block width direction. The intake port 13 is provided with an intake valve 15 that opens and closes the intake port 13, and the exhaust port 14 is provided with an exhaust valve 16 that opens and closes the exhaust port 14. The intake valve 15 and the exhaust valve 16 are driven by cam portions 19 a and 20 a provided on the outer periphery of the rotating cam shafts 19 and 20.

  Specifically, the intake valve 15 and the exhaust valve 16 are urged in the closing direction (upward in FIG. 1) by valve springs 17 and 18, respectively. Swing arms 21 and 22 are interposed between the intake valve 13 and the exhaust valve 14 and the cam portions 19a and 20a, respectively. One end portions of the swing arms 21 and 22 are supported on top portions of hydraulic lash adjusters (hereinafter referred to as HLA) 24 and 25, respectively. The swing arms 21, 22 swing about the tops of the HLAs 24, 25 as cam followers 21 a, 22 a rotatably provided at substantially central portions thereof are pushed downward by the cams 19 a, 20 a, respectively. By swinging in this way, the swing arms 21 and 22 open the intake valve 15 and the exhaust valve 16 at the other end against the urging force of the valve springs 17 and 18, respectively (downward in FIG. 1). Move to. The HLAs 24 and 25 automatically adjust the valve clearance to zero by hydraulic pressure.

  A cam cap 8 is attached to the upper part of the cylinder head 3. The cam shafts 19 and 20 are rotatably supported by the cylinder head 3 and the cam cap 8.

  A cylinder head side water jacket (hereinafter referred to as “head side WJ”) 41 through which cooling water for cooling the intake port 11, the exhaust port 12, etc. flows is formed at the lower part of the cylinder head 3. The head side WJ 31 communicates with the block side WJ 55 via a first WJ communication hole 41 provided in the gasket 4. Cooling water is supplied to the head side WJ 31 from the block side WJ 55 through the WJ communication hole 41 formed in the gasket 4.

  Next, the configuration around the cylinder liner 51 of the cylinder block 5 in the engine 2 will be described in detail with reference to FIGS. In addition, the arrow described in FIG. 2 shows the flow of the cooling water mentioned later.

  As described above, the engine 2 is a four-cylinder engine, and the cylinder block 5 is formed with four cylinder bores 53 in the cylinder row direction. In the cylinder block 5, the outer peripheral surface of the cylinder liner 51 is covered with an aluminum wall 54.

  In the cylinder block 5, the aluminum wall 54 is surrounded by four cylinder bores 53, that is, the intake side in the block width direction (upper side in FIG. 2) than the four cylinder bores 53 and the block width direction more than the four cylinder bores 53. Block sides WJ55 through which cooling water flows are formed on the exhaust side (lower side in FIG. 2), the left side of the leftmost cylinder bore 53, and the right side of the rightmost cylinder bore 53. The block side WJ55 at each position communicates without being partitioned from each other. The block side WJ 55 is formed so as to substantially follow the outer shape of the cylinder bore 53. In particular, the water channel located on the exhaust side which is one side of the block side WJ55 (hereinafter referred to as the exhaust side WJ portion 55b) and the water channel located on the intake side which is the other side (hereinafter referred to as the intake side WJ portion 55a). Are portions corresponding to the aluminum walls 54 between the cylinder bores 53, that is, the aluminum walls 54 between the two adjacent cylinder liners 51 (hereinafter referred to as the bore-to-bore wall portions 54a), and the intake side and exhaust side WJ portions 55a, It is formed so as to protrude closer to the center in the width direction of the cylinder block 5 than the other portions in 55b. In the present embodiment, the intake-side WJ portion 55a corresponds to a downstream flow channel, and the exhaust-side WJ portion 55b corresponds to an upstream flow channel.

  A plurality (ten in FIG. 2) of bolt holes 68 are formed in the cylinder block 5 on the intake side of the intake side WJ portion 55a and on the exhaust side of the exhaust side WJ portion 55a. The bolt hole 68 is a portion into which a head bolt (not shown) for fastening the cylinder head 3 and the cylinder block 5 via the gasket 4 is inserted, and the bolt hole 48 in the cylinder head 3 and the gasket 4 is inserted into the bolt hole 48. Similar bolt holes 32 and 42 (see FIG. 4) are also opened at corresponding positions.

  In each bore wall 54a of the cylinder block 5, a first drill hole 61 as a first processing hole for forming a cooling water channel 60 (see FIG. 4) and a second processing for forming the cooling water channel 60 are also provided. A second drill hole 62 is formed as a hole. Specifically, the first drill hole 61 is located at a position closer to the intake side WJ portion 55a in the block width direction of the inter-bore wall portion 54a, and the second drill hole 62 is located in the block width direction of the inter-bore wall portion 54a. It is formed at a position near the exhaust side WJ portion 55b. Further, the second drill holes 62 and the block side WJ 55 (in detail) are located at positions closer to the exhaust side than the second drill holes 62 on the upper surface (the surface on the cylinder head 3 side) of each bore wall 54a. In addition, a water channel groove 63 is formed for communicating a part of the cooling water flowing through the block side WJ55 into the second drill hole 62 so as to communicate with the exhaust side WJ portion 55b).

  As shown in FIG. 4, the first drill hole 61 is inclined downward (crank chamber side) from the intake side in the block width direction on the upper surface of the inter-bore wall portion 54a toward the exhaust side in the block width direction. Is formed. On the other hand, as shown in FIG. 4, the second drill hole 62 has a lower end (from the exhaust side, which is a position different from the first drill hole 61 in the block width direction, on the upper surface of the inter-bore wall portion 54a. The crank chamber side end) is formed so as to be inclined downward toward the intake side so as to join the lower end portion of the first drill hole 61. That is, the 1st and 2nd drill holes 61 and 62 are formed so that it may go to the direction which mutually approaches. The 1st and 2nd drill holes 61 and 62 form the confluence | merging part 64 in which a mutual lower end part merges. Thereby, the cooling water channel 60 formed by the first drill hole 61, the second drill hole 62, the merging portion 64, and the water channel groove 52 is a water channel having a substantially V-shaped section cut along the block width direction. It has become.

  At this time, the 1st and 2nd drill holes 61 and 62 consist of the confluence | merging part 64 in the inter-bore wall part 54a and the vicinity of the closest approach part to which the adjacent cylinder liners 51 approach most closely. It forms so that it may be located in the approach part 54b (refer FIG. 4). Further, as shown in FIGS. 4 and 6, the merging portion 64 overlaps with a portion (a position closer to the crank chamber side) below the center position in the vertical direction of a liner groove 51 a to be described later in the vertical direction. Formed as follows.

  As shown in FIG. 4, a water channel communication hole 43 that flows out from the first drill hole 61 is formed at a position corresponding to the upper end portion of the first drill hole 61 in the gasket 4. Further, a water channel communication hole 33 is formed in the cylinder head 3 at a position corresponding to the water channel communication hole 43. The water channel communication hole 33 communicates with the head side WJ31. That is, the first drill hole 61 communicates with the head side WJ 31 via the water channel communication holes 33 and 43.

  As shown in FIG. 5, each cylinder liner 51 is a cast iron liner formed into a cylindrical shape by centrifugal casting or the like. The outer peripheral surface of each cylinder liner 51 is subjected to an adhesion process for forming a large number of convex portions (not shown) in order to improve cast adhesion with an aluminum alloy except for a liner groove 51a described later. Yes.

  In the upper part of each cylinder liner 51, one circumferential groove-like liner groove 51 a (groove part) is formed extending over the entire circumference of the cylinder liner 51. Specifically, the liner groove 51a is formed to have a diameter reduced radially inward from other regions on the outer peripheral surface of the cylinder liner 51, and the first and second outer surfaces of the cylinder liners 51 in the inter-bore wall portion 54a. And in the part where the space | interval between the 2nd drill holes 61 and 62 becomes small, it forms in order to expand this space | interval, respectively. In particular, as shown in FIG. 6, each liner groove 51 a is formed so as to increase the distance between the outer peripheral surface of each cylinder liner 51 and the merging portion 64 at the approaching portion 54 b. Thereby, the contact between the first or second drill hole 61, 62 and the outer peripheral surface of the cylinder liner 51 is prevented at the approaching portion 54b.

  At this time, the size of the liner groove 51a in the vertical direction needs to be provided by the vertical length of the first and second drill holes 61 and 62 passing through the approach portion 54b in the approach portion 54b. . As in the present embodiment, in the block width direction, when the merging portion 64 is configured to be positioned at the approaching portion 54b, the vertical lengths of the first and second drill holes 61 and 62 that pass through the approaching portion 54b. Therefore, the size of the liner groove 51a in the vertical direction can be made relatively small.

  Next, the flow of the cooling water of the engine 2 according to the present embodiment will be described with reference to FIGS.

  The cooling water first flows into the block side WJ55. Specifically, the air flows from an inflow port (not shown) formed on the intake side in the block width direction on the rightmost side of the block side WJ55. After flowing in from the inflow port, the cooling water flows toward the exhaust side WJ portion 55b through the right side portion of the block side WJ55 as indicated by an arrow in FIG. After passing through the exhaust side WJ portion 55b, the coolant flows through the left side portion of the block side WJ55 to the intake side WJ portion 55a, and corresponds to the position of the gasket 4 on the right side of the intake side WJ portion 55a. It flows to the head side WJ31 through the second WJ communication hole 45 provided at the position. Thereafter, the cooling water circulates in the head side WJ31. That is, the cooling water flows in the block side WJ 55 such that the exhaust side WJ portion 55b is on the upstream side and the intake side WJ portion 55a is on the downstream side. As a result, the exhaust side in the block width direction, the temperature of which tends to rise due to the exhaust heat, can be cooled with the cooling water having a low water temperature, so that the cylinder bore 53 can be efficiently cooled.

  When the cooling water flows through the exhaust side WJ portion 55b, a part of the cooling water flows from the block side WJ55 (specifically, the exhaust side WJ portion 55b) to the cooling water channel 60 through the water channel groove 53. Specifically, the cooling water that has passed through the water channel groove 53 flows into the second drill hole 62. After flowing into the second drill hole 62, the cooling water flows obliquely downward in the second drill hole 62 toward the joining portion 64 and reaches the joining portion 64. The cooling water flows in the first drill hole 61 in an obliquely upward direction toward the upper surface of the bore wall portion 54a after reaching the junction 64. After reaching the upper surface of the bore wall portion 54a, the cooling water passes through the water channel communication hole 43 of the gasket 4 and flows through the water channel communication hole 33 of the cylinder head 3 to the head side WJ31. In other words, in addition to the cooling water flowing from the second WJ communication hole 45, the cooling water flowing into the first drill hole 61 via the second drill hole 62 and the merging portion 64 is supplied to the head side WJ portion 31. Further flows in. Thus, the cooling water flows through the cooling water passage 60 in the inter-bore wall portion 54a from the exhaust side to the intake side, thereby cooling the upper portion of the cylinder bore 53 from the position of the inter-bore wall portion 54a. be able to.

  Further, as described above, when the cooling water flows through the exhaust-side WJ portion 55b, the cooling water separates from the second WJ communication hole 45 and the cooling water channel 60, and the first WJ communication of the gasket 4 is performed. It flows from the block side WJ55 to the head side WJ31 through the hole 41 (see FIGS. 1 and 3).

  As described above, the second drill hole 62 communicates with the exhaust side WJ portion 55b, which is the upstream side of the block side WJ55, while the first drill hole 61 communicates with the head side WJ31. Further, since the cooling water after flowing through the cylinder side WJ55 flows into the head side WJ31, the head side WJ31 is on the downstream side in the flow of the cooling water. That is, the first drill hole 61 communicates with the downstream side in the flow of the cooling water, and the second drill hole 62 communicates with the upstream side in the flow of the cooling water. In general, since the pressure on the upstream side is higher than that on the downstream side, the cooling water flows in from the second drill hole 62 side having a relatively high pressure, and the first drill hole having a relatively low pressure. Outflow from 61 side. As a result, the cooling water easily passes in the width direction of the cylinder block 5 through the cooling water channel 60, and the cooling efficiency of the cylinder bore 53 using the cooling water channel 60 can be improved.

  Next, the manufacturing method of the cylinder block 5 in the cylinder main body 1 comprised as mentioned above is demonstrated.

  To manufacture the cylinder block 5 configured as described above, first, four cylindrical cylinder liners 51 are manufactured by centrifugal casting or the like. During the casting process, the outer peripheral surface of each cylinder liner 51 is subjected to a close contact process, and a large number of convex portions are formed on the outer peripheral surface of each cylinder liner 51.

  Next, an upper portion of the outer peripheral surface of each cylinder liner 51 is shaved over the entire circumference, and a liner groove 51 a is formed in each cylinder liner 51. As a result, no convex portion is formed on the liner groove 51 a on the outer peripheral surface of the cylinder liner 51. At this time, the liner groove 51a is formed so that the size in the vertical direction is approximately the same as the length in the vertical direction at the approach portion 54b of the first and second drill holes 61 and 62.

  Next, each cylinder liner 51 is set in a mold and cast with an aluminum alloy. By this step, the cylinder liner 51 is surrounded by the aluminum wall 54, and between the adjacent cylinder liners 51, the inter-bore wall portions 54a are formed. The block side WJ55, the bolt hole 68, and the like are also formed in this step.

  After the outer shape of the cylinder block 5 is completed, the first drill hole 61 is formed.

  Specifically, first, when the first drill hole 61 is formed from a predetermined position near the intake side in the block width direction on the upper surface of the bore wall portion 54a toward the exhaust side in the block width direction, The lower end portion of the first drill hole 61 is located at a position corresponding to the approaching portion 54b of the inter-bore wall portion 54a in the block width direction of the cylinder block 5, and in the liner groove 51a in the vertical direction of the cylinder block 5. The angle and length of the hole to be processed are calculated by a computer or the like so as to be formed at a position overlapping with the lower side of the center position in the vertical direction in the liner groove 51a within the vertical direction. At this time, the length of the hole is calculated in consideration of the formation of the merging portion 64.

  After the calculation, the first drill is mounted on the machine tool, and the predetermined length is obtained at the calculated angle from the predetermined position near the intake side on the upper surface of the bore wall 54a toward the exhaust side. The hole is formed by counterboring by the amount of. The length of the counterbored hole may be calculated by the above calculation, or may be arbitrarily determined by the manufacturer. When the manufacturer arbitrarily determines, it is desirable for the manufacturer to input the length of the hole by counterboring in advance to a computer or the like.

  After counterbore processing, a second drill having a diameter smaller than that of the first drill is attached to the machine tool, and the calculated length is calculated from the bottom of the counterbored hole toward the exhaust side at the calculated angle. The hole is formed by this processing by the amount of. Thereby, the first drill hole 61 is formed.

  After the first drill hole 61 is formed, the second drill hole 62 is formed.

  Specifically, first, when the second drill hole 62 is formed from a predetermined position near the exhaust side on the upper surface of the inter-bore wall portion 54a toward the intake side, the second drill hole 62 The lower end portion merges with the lower end portion of the first drill hole 61, and the merge portion 64 is located at a position corresponding to the approaching portion 54b in the inter-bore wall portion 54a in the block width direction of the cylinder block 5, In the vertical direction of the cylinder block 5, the angle of the hole to be machined so as to be formed within the range in the vertical direction of the liner groove 51 a and overlapping with the lower side of the center position in the vertical direction of the liner groove 51 a The length is calculated by a calculator or the like.

  After the above calculation, as in the case of the first drill hole 61, the first drill is mounted on the machine tool, and the first drill hole 61 starts from a predetermined position near the exhaust side on the upper surface of the inter-bore wall portion 54a. A hole is formed by counterbore processing by a predetermined length at the calculated angle toward the intake side in the block width direction opposite to that of the block width direction.

  After the counterboring process, similarly to the case of the first drill hole 61, a second drill having a diameter smaller than that of the first drill is attached to the machine tool, and the above-mentioned hole is formed from the counterbored hole toward the intake side. At the calculated angle, the hole is formed by this processing for the calculated length. Thereby, the second drill hole 62 is formed. When the second drill hole 62 is formed, the lower end portion of the first drill hole 61 and the lower end portion of the second drill hole 62 merge to form a merge portion 64.

  After the second drill hole 62 is formed, the water channel groove 53 is formed. In the present embodiment, the second drill hole 62 on the upper surface portion of the inter-bore wall portion 54a is communicated with the second drill hole 62 and the block side WJ55 by using the machining device on which the second drill is mounted. Also, the exhaust side portion is formed by cutting two portions at a predetermined depth at the tip of the second drill. Thereby, the cooling water channel 60 is completed.

  Thus, the cylinder block 5 in the cylinder body 1 is completed.

  By forming the cooling water channel 60 as described above, the merging portion 64 where the lower end portion of the first drill hole 61 and the lower end portion of the second drill hole 62 merge together is an approaching portion 54b in the inter-bore wall portion 54a. In FIG. 3, the liner groove 51a is formed at a position within the range in the vertical direction and at a position overlapping the lower side of the center position in the vertical direction of the liner groove 51a. Thereby, since the vertical length of the approaching portion of the drill holes 61 and 62 passing through the approaching portion 54b can be made relatively small, the size of the liner groove 51a can be made relatively small. it can. As a result, it is possible to reduce the decrease in the contact processing region on the outer peripheral surface of the cylinder liner 51 due to the formation of the liner groove 51a, and to improve the casting adhesion of the cylinder liner 51.

  In addition, since the merge portion 64 is formed so as to overlap with the lower side of the center position in the vertical direction of the liner groove 51a in the vertical direction, the size of the liner groove 51a in the vertical direction is made as small as possible. The depth of the cooling water channel 60 can be ensured to the maximum, and as a result, the cylinder bore 53 can be cooled by the cooling water channel 60 while improving the casting adhesion of the cylinder liner 51.

  Therefore, according to the present embodiment, the cylinder block 5 is provided on the bore wall portion 54a, and is inclined from the upper surface of the bore wall portion 54a toward the crank chamber 6 toward the exhaust side in the block width direction. In the upper surface of the first drill hole 61 and the inter-bore wall portion 54a where the first drill hole 61 is formed, the lower end portion of the first drill hole 61 has a first lower end from a position different from the first drill hole 61 in the block width direction. Second drills formed to be inclined toward the crank chamber 6 toward the intake side which is the block width direction opposite to the first drill hole 61 so as to merge with the lower end portion of the drill hole 61 of the first drill hole 61. Since the cooling water channels 60 formed by the holes 62 are provided, even when the cooling water channel 60 is formed over the entire width direction of the cylinder block 5, the And the vertical length of the second borehole 61, 62 becomes about half. Therefore, there is less blurring during processing than in the past, and the cooling water channel 60 can be easily formed.

  A liner groove 51a is formed on the outer peripheral surface of the cylinder liner 51 to widen the gap between the first and second drill holes 61 and 62. The lower end of the first drill hole 61 and the second The joining portion 64 where the lower end portion of the machining hole 62 joins is formed in the approaching portion 54b of the inter-bore wall portion 54a in the block width direction and at a position overlapping the liner groove 51a in the vertical direction. Therefore, only a part of the first drill hole 61 and a part of the second 42 hole pass through the approach part 54b, and the first and second drill holes 61, 62 passing through the approach part 54b. The length of the approaching portion 54b in the vertical direction is reduced. Thereby, the size of the liner groove 51a in the vertical direction can be reduced, and the decrease in the contact processing area on the outer peripheral surface of the cylinder liner 51 due to the formation of the liner groove 51a can be reduced. The casting adhesion can be improved.

  The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above embodiment, an in-line four-cylinder gasoline engine is targeted, but the number of cylinders of the engine may be five or more.

  In addition, the liner groove 51a is formed over the entire circumference of the outer peripheral surface of the cylinder liner 51. However, the present invention is not limited thereto, and the liner groove 51a may be provided only in a portion corresponding to the approaching portion 54b.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention is useful as a cylinder body structure of a multi-cylinder engine.

DESCRIPTION OF SYMBOLS 1 Cylinder main body 2 Engine 3 Cylinder head 5 Cylinder block 5a Crank chamber 13 Intake port 14 Exhaust port 31 Head side WJ (Cylinder head side water jacket)
51 Cylinder liner 51a Liner groove (groove)
53 Cylinder bore 54 Aluminum wall (wall)
54a Bore wall (wall between adjacent cylinder bores)
54b Approaching part (the closest part and the vicinity of the closest part)
55 Block side WJ (Cylinder block side water jacket)
55a Exhaust side WJ section (upstream flow channel)
55b Intake side WJ section (downstream flow channel)
60 Cooling water channel (water channel)
61 1st drill hole (1st processing hole)
62 2nd drill hole (1st processing hole)
64 Junction

Claims (4)

A cylinder block having a plurality of cylinder liners forming a cylinder bore and being cast;
A cylinder head attached to the cylinder block;
A cylinder body structure of a multi-cylinder engine provided with a crank chamber formed on the side opposite to the cylinder head in the cylinder block,
First provided respectively on a wall portion between adjacent cylinder bores in the cylinder block and inclined from the surface on the cylinder head side of the wall portion toward the crank chamber side in the width direction of the cylinder block. On the cylinder head side surface of the wall where the first machining hole is formed, and from the position different from the first machining hole in the width direction of the cylinder block, the crank chamber side Are formed so as to be inclined toward the crank chamber side in the width direction opposite to the first processing hole so that the end portion of the first processing hole merges with the end portion of the first processing hole on the crank chamber side. A second processing hole and a water channel respectively formed by
Grooves are formed on the outer peripheral surface of the cylinder liner to widen the distance between the first and second machining holes.
The joining portion where the end portion on the crank chamber side of the first processing hole and the end portion on the crank chamber side of the second processing hole join is the cylinder liner in the wall portion in the width direction of the cylinder block. A cylinder of a multi-cylinder engine, which is formed in a position closest to each other and in the vicinity of the closest portion, and formed in a position overlapping with the groove in the axial direction of the cylinder liner Body structure. The cylinder body structure of the multi-cylinder engine according to claim 1,
The cylinder main body structure of a multi-cylinder engine, wherein the merging portion is formed at a position closer to the crank chamber side than a central position in the axial direction of the cylinder liner in the groove portion. The cylinder body structure of the multi-cylinder engine according to claim 1 or 2,
A cylinder block-side water jacket provided around the cylinder bore in the cylinder block, through which cooling water flows;
A cylinder head-side water jacket provided in the cylinder head and through which cooling water flows,
The cylinder block-side water jacket is configured such that the cooling water flows through an upstream-side flow channel that is a water channel on one side in the width direction of the cylinder block in the cylinder block-side water jacket, and then the cylinder in the cylinder block-side water jacket. It is configured to circulate through the downstream flow channel that is the other channel in the width direction of the block,
The cylinder head-side water jacket is configured such that cooling water after flowing through the downstream-side flow channel flows in.
The first processing hole is formed at a position near the downstream water channel in the width direction of the cylinder block of the wall portion, and communicates with the cylinder head side water jacket.
The second machining hole is formed at a position near the upstream flow channel in the width direction of the cylinder block of the wall portion, and communicates with the cylinder block-side water jacket,
A cylinder main body structure for a multi-cylinder engine, wherein cooling water that has flowed into the first processing hole further flows into the cylinder head side water jacket through the second processing hole and the merging portion. The cylinder main body structure of the multi-cylinder engine according to any one of claims 1 to 3,
The cylinder head includes an intake port and an exhaust port,
The intake port is disposed on the same side as the side on which the first processing hole of the cylinder block is disposed in the width direction of the cylinder head.
The cylinder body structure of a multi-cylinder engine, wherein the exhaust port is arranged on the same side as the side where the second machining hole of the cylinder block is arranged in the width direction of the cylinder head.

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