JP5060414B2 - Closed deck type cylinder block and manufacturing method thereof - Google Patents

Description

  The present invention relates to a closed deck type cylinder block in which a water jacket is formed by casting an insert member and a manufacturing method thereof.

  A cylinder block used in a water-cooled engine has a water jacket for engine cooling. The water jacket is formed between the cylinder and the outer wall of the block, and cooling water flows through the water jacket. By flowing the cooling water through the water jacket, the effect of cooling the cylinder can be obtained, and the noise generated in the cylinder bore can be absorbed to reduce the noise.

  Here, the cylinder block is roughly classified into two types, a closed deck type and an open deck type. The closed deck type includes a bridge connecting a cylinder having a cylinder bore and a block outer wall on the upper deck surface on the cylinder head fastening side. On the other hand, the open deck type does not have a bridge and the cylinder and the block outer wall are separated on the upper deck surface. The closed deck type cylinder has a merit such that the cylinder and the block outer wall are joined by providing a bridge on the upper deck surface of the cylinder block, which improves vibration resistance and reduces noise. Has the disadvantage of becoming difficult.

  In recent years, cylinder blocks are often manufactured by die casting from the viewpoint of production efficiency. However, in order to form a water jacket provided in a closed deck type cylinder block, it is necessary to use a collapsible core, and the advantages of die casting cannot be utilized. That is, at the time of die-casting the cylinder block, it is necessary to supply the molten metal with a casting pressure that does not break the core that forms the water jacket, and it is necessary to slow the molten metal flow rate. For this reason, the production speed is reduced, and it becomes difficult to obtain the mass production effect that is considered to be a merit in die casting.

  For these reasons, it is not uncommon for the closed deck type cylinder block to be molded by casting. Also, there is a case where rigidity is secured by reinforcing another part of the cylinder block and an open deck type cylinder block is adopted for the engine.

However, when a higher rigidity is desired (for example, when used for a diesel engine), a closed deck type cylinder block is more advantageous. Therefore, improvement in production efficiency is also required for the closed deck type cylinder block. And regarding a closed deck type cylinder block, for example, Patent Document 1 discloses a technique in which a hollow insert member is cast and the inside of the insert member is used as a water jacket.
JP 2000-230455 A

  However, in the technique disclosed in Patent Document 1 described above, it is necessary to prevent deformation of the insert member when performing high-pressure die casting where the casting pressure is 50 to 80 MPa. When forming a water jacket in the cylinder block by casting the insert member, if the insert member is deformed and a part of the cooling water passage is blocked, the flow of the cooling water deteriorates and the cooling performance of the cylinder block is reduced. Deteriorates significantly. For this reason, in the technique disclosed in Patent Document 1, when high pressure die casting is performed, a filler such as metal particles or sand is disposed inside the insert member in order to prevent deformation of the insert member. In this case, since a step of taking out the filler after casting is necessary, there is a problem that the number of steps increases and productivity decreases.

  Here, if the casting pressure is lowered, it is not necessary to arrange the filler inside the insert member, and the number of steps can be prevented from increasing. However, the die casting product improves the quality by improving the casting pressure and improves the quality. Therefore, when the casting pressure is lowered, the molding condition deteriorates and a high quality die casting product (cylinder block) can be obtained. become unable.

  In addition, as described in the cited document 1, there is a technique in which a reinforcing rib is provided inside the insert member to increase the strength of the insert member. However, when a relatively large cavity such as a water jacket is secured by high pressure die casting, there is a possibility that a portion where no reinforcing rib is provided is deformed. In order to prevent such deformation, a plurality of reinforcing ribs may be provided. However, if a plurality of reinforcing ribs are provided, the cooling performance deteriorates due to the disturbance of the flow of cooling water in the water jacket, and a sufficient cooling effect cannot be obtained.

  Further, when the insert member is cast, positioning of the insert member is required. However, in Patent Document 1, the lower part of the insert member is only held by the annular holding member. For this reason, when performing high pressure die-casting, there exists a possibility of shifting | deviating with the pressure of a molten metal. In recent years, both higher output and improved fuel efficiency are required for engines, and the thickness of the cylinder block is reduced. Therefore, a certain degree of accuracy is required for the position of the water jacket. From such a situation, it is desired that the insert member to be cast for casting the cylinder block is appropriately held so as not to be displaced and the insert member to be cast is appropriately positioned and cast.

  Therefore, the present invention has been made to solve the above-described problems, and it is possible to form a water jacket having a desired shape even in high-pressure die casting without placing a filler inside the insert member. It is an object of the present invention to provide a closed deck type cylinder block and a method for manufacturing the same.

  A closed deck type cylinder block according to the present invention made to solve the above problems is a closed deck type comprising a plurality of cylinders in which pistons slide, and a water jacket for circulating cooling water for cooling the cylinders. The cylinder block includes an inner cylinder portion and an outer cylinder portion, and has a hollow member that is disposed around the cylinder to form a water jacket, and the hollow member includes an inner wall surface of the inner cylinder portion and the A plurality of connecting members that connect the inner wall surface of the outer cylinder portion are provided in a dispersed manner.

  This cylinder block is formed by die casting, in which a hollow member (insert member) serving as a water jacket is cast. In the hollow member, a plurality of connecting members that connect the inner wall surface of the inner cylinder portion and the inner wall surface of the outer cylinder portion are provided in a dispersed manner. As a result, the mechanical strength of the hollow member can be greatly improved, and even in high-pressure die casting where the casting pressure is 50 to 80 MPa, the hollow member is deformed and partially passes through the cooling water passage in the water jacket. Can be blocked. Therefore, a water jacket having a desired shape can be formed by high-pressure die casting without disposing a filler inside the hollow member.

Further, since the connecting members are provided in a distributed manner, the flow of the cooling water in the water jacket can be prevented from being disturbed. That is, even if the connecting member is provided, the dispersive arrangement causes the cooling water to flow smoothly and no separation flow occurs, so that no cavitation occurs and the cooling effect of the cylinder block is not reduced.
In addition, as a dispersion | distribution (arrangement | positioning) form of a connection member, it is good also as a form with a certain regularity like a zigzag shape, or as a form which changes the flow of the cooling water in a water jacket intentionally. Also good.

In closed deck type cylinder block according to the present invention, it communicates with the hollow member, that having a water channel projections of the plurality of hollow shape provided on the upper deck surface side with an opening facing said cylinder.

  By having such a waterway protrusion, a part of the mold (insertion protrusion) can be inserted into the waterway protrusion to fix the hollow member to the mold. Thus, the casting can be appropriately positioned and cast so that the hollow member to be cast is not displaced by the pressure of the molten metal during casting. Therefore, the position accuracy of the water jacket in the cylinder block can be increased.

  In addition, although the protrusion for water channels is hollow shape, since a part of metal mold | die is inserted in a hollow part, even if it is a high pressure die-casting, it does not deform | transform by the pressure of a molten metal, and a molten metal does not penetrate | invade. The water channel protrusion may be formed by connecting a pipe to the hollow member, or may be formed integrally with the hollow member.

In the closed deck type cylinder block according to the present invention, the connecting member, at least one of the inner cylinder part or the outer cylindrical portion, that is formed by the provided sticking the hollow member inner protrusions .

  By forming the connecting member with such protrusions, the connecting member can be easily formed by press molding or the like. Thereby, by providing a connection member, it can prevent that productivity of a hollow member falls and a production cost rises. Therefore, by carrying out high-pressure die casting by casting a hollow member having such a connecting member, it is possible to prevent a decrease in productivity and an increase in production cost, and a high-quality cylinder block in which a water jacket having a desired shape is formed. Obtainable.

  Here, when the connecting member is formed by a projection formed by pressing or the like, the molten metal flows into the inside (recessed portion) of the projection. For this reason, if a protrusion is provided only on the inner cylinder part or only the outer cylinder part of the hollow member, a difference occurs between the pressure of the molten metal received from the inner cylinder part side of the hollow member and the pressure of the molten metal received from the outer cylinder part side. Therefore, the hollow member may be deformed by the pressure difference.

  Therefore, in the closed deck type cylinder block according to the present invention, the connecting member abuts the front end portions of the protrusions provided on both the inner tube portion and the outer tube portion so as to protrude inside the hollow member. It is preferable that the protrusion provided on the inner cylinder part and the protrusion provided on the outer cylinder part are symmetrical.

  In this way, the connecting member is formed by abutting the tip portions of the protrusions provided on the inner cylinder part and the outer cylinder part so as to protrude inside the hollow member, and the protrusion provided on the inner cylinder part, By making the protrusion provided on the outer cylinder part symmetrical, the pressure of the molten metal received from the inner cylinder part side of the hollow member and the pressure of the molten metal received from the outer cylinder part side can be made equal. The deformation of the hollow member due to pressure can be reliably prevented.

  Further, in the closed deck type cylinder block according to the present invention, it is desirable to have a cooling water inlet provided in the outer wall of the outer cylinder portion in order to introduce the cooling water into the hollow member.

  By providing such a cooling water introduction port, there is no need to process the cooling water introduction port after molding the cylinder block, and a part of the mold (insertion protrusion) is inserted into the cooling water introduction port to form a hollow member in the mold. The positioning accuracy when fixing can be further improved. That is, since the hollow member is positioned by the water channel protrusion and the cooling water introduction port and held by the mold, the hollow member to be cast can be more reliably prevented from being displaced by the pressure of the molten metal during casting. As a result, the productivity of the cylinder block can be improved, and the position accuracy of the water jacket in the cylinder block can be further increased. Although the inside of the cooling water inlet is hollow, a part of the mold is inserted into the hollow portion, so even in high-pressure die casting, it does not deform due to the pressure of the molten metal, and the molten metal enters. There is nothing.

Further, in the closed deck type cylinder block according to the present invention, the hollow member includes a plurality of metal plates formed in a U-shaped cross-section by bending both ends in the cylinder axial direction, and the bent portions are overlapped with each other. that is formed by joining together.

  The hollow member can be formed using a pipe material. However, when production efficiency and production cost are taken into consideration, formation using a metal plate is advantageous in terms of production efficiency and production cost. That is, in order to form a hollow member into the shape of a water jacket using a pipe material, a complicated molding process is required, so that production efficiency is reduced and production cost is increased. On the other hand, when a hollow member is formed using a metal plate, a press-formed metal plate can be joined to obtain a hollow member having a predetermined shape, thereby improving production efficiency and reducing production cost. can do.

  Then, both ends of the metal plate in the cylinder axial direction are bent to form a U-shaped cross section, and the bent portions are overlapped with each other to form a hollow member, thereby forming both ends of the hollow member in the cylinder axial direction. The mechanical strength in the portion (upper and lower ends) can be increased. Thereby, the mechanical strength of the entire hollow member can be further increased. In addition, what is necessary is just to perform joining of metal members by welding, brazing, etc.

  A closed deck type cylinder block manufacturing method according to the present invention made to solve the above problems includes a plurality of cylinders in which pistons slide inside, and a water jacket for circulating cooling water for cooling the cylinders. In the manufacturing method of manufacturing a closed deck type cylinder block by casting using a mold, as an insert member for forming a water jacket arranged around the cylinder, an inner cylinder part, an outer cylinder part, A plurality of dispersed connection members that connect the inner wall surface of the inner cylinder part and the inner wall surface of the outer cylinder part, and a hollow water channel provided on the upper deck surface side facing the opening of the cylinder A hollow member forming step for forming a hollow member having a protrusion, and the water channel protrusion of the hollow member formed in the hollow member forming step. A hollow member disposing step of inserting an insertion projection formed on the mold into the hollow portion to hold the hollow member, positioning the hollow member in the cavity of the mold, and disposing the hollow member A casting step of casting the hollow member held in the mold in a step and die-casting a cylinder block.

  In this cylinder block manufacturing method, in the hollow member forming step, a hollow member serving as an insert member for forming the water jacket is formed. At this time, a plurality of connecting members that connect the inner wall surface of the inner cylinder part and the inner wall surface of the outer cylinder part are formed in the hollow member in a dispersed manner. For this reason, the mechanical strength of the hollow member can be increased. Further, a hollow water channel projection is provided on the upper deck surface side.

  And such a hollow member is arrange | positioned in the cavity of a metal mold | die at a hollow member arrangement | positioning process. At this time, the insertion member formed in the mold is inserted into the hollow part of the water channel protrusion provided in the hollow member to hold the hollow member. Thereby, the hollow member is positioned in the cavity of the mold.

  Thereafter, in the casting process, the hollow member held in the mold in the hollow member arranging process is cast and the cylinder block is die-cast. At this time, since the mechanical strength of the hollow member is increased by the connecting member even when high pressure die casting at a casting pressure of 50 to 80 MPa is performed, the hollow member is deformed and the cooling water passage is partially formed in the water jacket. Can be blocked. In addition, since the insertion member of the mold is inserted into the projection for the water channel and the hollow member is fixed to the mold, the hollow member to be cast is properly positioned without being displaced by the pressure of the molten metal during casting. can do.

  As described above, according to the manufacturing method of the present invention, it is possible to manufacture a high-quality cylinder block in which a water jacket having a desired shape is formed by high-pressure die casting without placing a filler inside the hollow member. . And in this manufacturing method, since the taking-out process of a filler is unnecessary, production efficiency improves.

In the closed deck type cylinder block manufacturing method according to the present invention, in the hollow member forming step, a plurality of metal plates formed into a U-shaped cross section by bending both ends in the cylinder axial direction are joined to each other. forming the hollow member by joining superposed.

  In this way, by forming a plurality of metal plates by pressing or the like and forming a hollow member by overlapping and joining the bent portions, the production efficiency is improved and the production cost is reduced compared to the case of using a pipe material. Can be reduced. Further, the mechanical strength at both ends (upper and lower ends) of the hollow member in the cylinder axial direction can be increased, and the mechanical strength of the entire hollow member can be further increased.

Further, in the closed deck type cylinder block manufacturing method according to the present invention, in the hollow member forming step, at least one of the inner cylinder part or the outer cylinder part is provided so as to protrude inside the hollow member. forming the connecting member by the projection.

  By forming the connecting member with such protrusions, the connecting member can be easily provided inside the hollow member by press molding or the like. Thereby, it can prevent that productivity of a hollow member falls and a production cost rises by providing a connection member.

  According to the closed deck type cylinder block and the manufacturing method thereof according to the present invention, as described above, a water jacket having a desired shape can be formed by high pressure die casting without placing a filler inside the hollow member which is an insert member. A high quality cylinder block can be obtained by forming.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a most preferred embodiment that embodies a closed deck type cylinder block and a manufacturing method thereof according to the present invention will be described in detail based on the drawings. Here, a case where the present invention is applied to a cylinder block used in an in-line four-cylinder engine is illustrated.

  First, the cylinder block which concerns on this Embodiment is demonstrated, referring FIGS. 1-3. FIG. 1 is a top view showing a schematic configuration of a cylinder block according to the embodiment. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a perspective view showing a water jacket in the cylinder block.

  As shown in FIGS. 1 and 2, a cylinder block 10 according to the present embodiment is used for an in-line four-cylinder engine, and four cylinder bores 11 are formed inside a cylinder 12. The cylinder block 10 is a closed deck type, and a cylinder 12 and a block outer wall 13 are connected by a bridge 14.

  A plurality of head bolt holes 15 are provided in the upper deck surface 10a of the cylinder block 10 so that a cylinder head (not shown) can be fastened with the head bolts. Here, four head bolt holes 15 are provided around the cylinder bore 11. However, since the adjacent cylinder bores 11 share the bolt holes as shown in FIG. 1, two head bolt holes 15 are provided between the first cylinder bore 11a and the second cylinder bore 11b.

  On the other hand, as shown in FIG. 2, a crank bolt hole 17 for attaching a crank cap is provided in the lower portion of the cylinder block 10. The crank bolt hole 17 is a bolt hole for fixing the crank cap to the cylinder block 10 so as to hold the crank shaft between a crank cap (not shown) and the journal portion 19 of the cylinder block 10.

  Further, as shown in FIG. 1, a water jacket 16 is formed around the cylinder 12 in the cylinder block 10. The water jacket 16 is provided for cooling the cylinder 12, and cooling water flows inside the engine when the engine is operating. Here, the water jacket 16 is formed of the cooling hollow material 30 shown in FIG. That is, the cooling hollow member 30 is cast in the cylinder block 10, and the inside of the cooling hollow member 30 is the water jacket 16. The cooling hollow material 30 can be made of stainless steel in consideration of corrosion resistance, or can be made of aluminum alloy in the same manner as the material of the cylinder block 10 in consideration of recyclability.

  Here, the cooling hollow material 30 forming the water jacket 16 will be described with reference to FIGS. 3 and 4 to 7. FIG. 4 is an exploded perspective view of the cooling hollow material. FIG. 5 is a perspective view showing a cross section of the cooling hollow material. FIG. 6 is a view showing a gas vent groove formed in a concave portion of a protrusion provided in the cooling hollow material. 7 is a cross-sectional view taken along line VII-VII in FIG.

  The cooling hollow member 30 is composed of a plurality of metal plates. That is, the cooling hollow material 30 is formed by joining metal plates processed into a predetermined shape to each other. In the present embodiment, as shown in FIG. 4, the cooling hollow member 30 includes four metal plates 31 to 34 constituting the water jacket 16 and a cooling water inlet for introducing cooling water into the water jacket 16. It is formed by a connection member 35 and a water intake 36 for constituting 46.

  Each of the metal plates 31 to 34 is press-molded into a predetermined shape as shown in FIG. 4 so as to have the shape of the water jacket 16 when they are combined. The inner cylinder metal plates 31 and 32 constituting the inner cylinder portion 30a disposed on the cylinder 12 side are provided with protrusions 37 having a substantially circular cross section in a staggered manner by embossing. The protrusion 37 is formed outward so as to protrude into the water jacket 16. The inner cylindrical metal plates 31 and 32 are formed with bent portions 31a, 31b, 32a, and 32b in which both ends (upper and lower ends) in the axial direction of the cylinder 12 are bent outward. And the through-hole 41 is formed in the bending part 31a, 32a in the position corresponding to the water jacket protrusion 40 mentioned later. Thus, when the metal plates 31 to 34 are combined, the lower opening of the water jacket projection 40 is positioned in the through hole 41, and the water channel opening 16a in the water jacket projection 40 (see FIG. 2). ) And the inside of the cooling hollow material 30 (water jacket 16) communicate with each other. In place of the through hole 41, a notch may be provided.

  On the other hand, the outer cylinder metal plates 33 and 34 constituting the outer cylinder portion 30b arranged on the block outer wall 13 side are provided with protrusions 38 having a substantially circular cross section in a staggered manner by embossing. The protrusion 38 is formed inward so as to protrude into the water jacket 16. The protrusion 38 and the protrusion 37 are substantially symmetrical (identical). And the protrusion 38 is arrange | positioned so that it may contact | abut the protrusion 37, when each metal plate 31-34 is combined. Further, the outer cylindrical metal plates 33, 34 are formed with bent portions 33a, 33b, 34a, 34b in which both axial ends (upper and lower ends) of the cylinder 12 are bent inward. A plurality of water jacket protrusions 40 are provided in the bent portions 33a and 34a. The water jacket projection 40 has a hollow shape and allows the inside of the water jacket 16 and the upper deck surface 10a of the cylinder block 10 to communicate with each other. And the inside of the water jacket protrusion 40 serves as the water channel opening 16a. As a result, only the water channel opening 16 a appears as an opening of the water jacket 16 on the upper deck surface 10 a of the cylinder block 10. Therefore, the cylinder block 10 is configured as a closed deck type. And the water channel opening part 16a is connected with the water jacket provided in the cylinder head which is not shown in figure, and flows cooling water. Furthermore, the outer cylinder metal plate 33 is provided with an opening 39 communicating with the cooling water inlet 46.

  And the hollow material 30 for cooling is formed by combining and joining such metal plates 31-34. Specifically, as shown in FIG. 5, the projection 37 provided on the inner cylinder metal plates 31 and 32 and the projection 38 provided on the outer cylinder metal plates 33 and 34 are abutted with each other, and the bent portions 31a and 31a, 31b, 32a, 32b and the bent portions 33a, 33b, 34a, 34b are superposed and joined together to form the cooling hollow material 30. As a result, a connecting member 45 that connects the inner wall surfaces of the inner cylindrical metal plates 31 and 32 and the inner wall surfaces of the outer cylindrical metal plates 33 and 34 is formed in the cooling hollow member 30 by the protrusions 37 and 38. Is done. Since the protrusions 37 and 38 are provided in a staggered manner, the connecting member 45 is also arranged in a staggered manner. That is, a plurality of connecting members 45 are dispersed and arranged in the cooling hollow material 30. With these connecting members 45, the mechanical strength of the cooling hollow member 30 is increased. Further, since the bent portions 31a, 31b, 32a, and 32b and the bent portions 33a, 33b, 34a, and 34b are overlapped at the upper and lower ends of the cooling hollow material 30, the mechanical strength is increased. As a result, the mechanical strength of the cooling hollow member 30 is enhanced as a whole.

  Further, as shown in FIGS. 6 and 7, a plurality of gas vent grooves 42 are formed in the recesses 37 a and 38 a of the protrusions 37 and 38. The gas vent groove 42 may be formed by coining or the like. In the present embodiment, five gas vent grooves arranged in parallel to one projection 37, 38 are formed, three of which are provided in the recesses 37a, 38a of the projections 37, 38. The remaining two are provided outside the recesses 37a and 38a.

  Further, as shown in FIG. 3, the cooling hollow material 30 is provided with a cooling water inlet 46 for introducing cooling water therein. The cooling water inlet 46 is provided on the outer wall of the outer cylinder metal plate 33 that becomes the outer cylinder part 30 b of the cooling hollow material 30. As shown in FIG. 4, the cooling water inlet 46 is formed by joining a connecting member 35 and a water intake 36. The connecting member 35 is joined along the outer edge portion of the opening 39 of the outer cylindrical metal plate 33, and the cooling water inlet 46 is attached to the cooling hollow material 30.

  Next, a method for manufacturing the cylinder block 10 will be described with reference to FIGS. FIG. 8 is a diagram illustrating a state in which the cooling hollow material is fixed to the upper mold. FIG. 9 is a diagram illustrating a state where the insertion pin provided in the slide mold is inserted into the cooling water introduction port. In the manufacture of the cylinder block 10, a hollow material forming step for forming the cooling hollow material 30, a hollow material arrangement step for positioning and arranging the cooling hollow material 30 in the mold, and a cylinder block is die-cast by casting the cooling hollow material 30. A casting process for forming is performed.

  First, in the hollow material forming step, the cooling hollow material 30 is manufactured. Specifically, as shown in FIG. 4, among the four metal plates 31 to 34 that are preliminarily formed into a predetermined shape, first, the end portions of the inner cylinder metal plate 31 and the inner cylinder metal plate 32 are joined to each other. And the inner cylinder part 30a of the hollow material 30 for cooling is formed. And while joining the outer cylinder metal plates 33 and 34 with respect to the inner cylinder part 30a formed with the inner cylinder metal plates 31 and 32, the edge parts of the outer cylinder metal plates 33 and 34 are joined. At this time, the projections 37 provided on the inner cylinder metal plates 31 and 32 and the projections 38 provided on the outer cylinder metal plates 33 and 34 are brought into contact with each other, and the bent portions 31a, 31b, 32a and 32b and the bent portion 33a are brought together. , 33b, 34a, 34b are superimposed. In this way, the inner cylinder part 30a formed by the inner cylinder metal plates 31 and 32, the outer cylinder part 30b formed by the outer cylinder metal plates 33 and 34, and the connecting member 45 formed by the protrusions 37 and 38. The part which becomes the water jacket 16 of the hollow material 30 for cooling is completed. Thereafter, the water intake 36 is joined to the connecting member 35 to form the cooling water inlet 46, which is joined along the outer edge portion of the opening 39 provided in the outer cylinder metal plate 33. Thus, the cooling hollow material 30 is formed. In addition, what is necessary is just to perform joining of each member 31-36 which comprises the hollow material 30 for cooling by welding or brazing.

  Here, the cooling hollow material 30 can be manufactured using a pipe material. However, in consideration of production efficiency and production cost, by using the metal plate as described above, production efficiency and production cost can be reduced. It will be advantageous. That is, in order to form the cooling hollow material 30 into the shape of the water jacket using the pipe material, a complicated forming process is required, so that the production efficiency is lowered and the production cost is raised. On the other hand, when the cooling hollow member 30 is manufactured using a metal plate, it is only necessary to join the press-formed metal plate, so that the production efficiency can be improved and the production cost can be reduced.

  Next, in the hollow material arranging step, the cooling hollow material 30 manufactured as described above is set in a mold. Here, as shown in FIG. 8, the mold 50 used for die casting is a split mold including a fixed mold 52, a slide mold 53, an upper mold 51, and the like. In FIG. 8, the upper die 51 is indicated by a solid line, and the others are indicated by two-dot chain lines.

  The upper die 51 is provided with a cylinder bore protrusion 51a and a positioning pin 51b. The cylinder bore protrusions 51a are protrusions for holding the cylinder liner 12a, and four cylinder bore protrusions 51a are provided for an inline 4-cylinder engine. In the case where the cylinder liner 12a is not used, the projections that form the cylinder bores 11 are formed. The positioning pin 51b is a protrusion for positioning the cooling hollow member 30 and preventing the water jacket protrusion 40 from being deformed during die casting, and is fitted to the water channel opening 16a of the water jacket protrusion 40. It is supposed to be.

  As shown in FIG. 9, the slide mold 53 is provided with an insertion pin 54a. The insertion pin 54a is a protrusion for positioning the cooling hollow member 30 and preventing the cooling water introduction port 46 from being deformed during die casting, so that the insertion pin 54a is fitted to the cooling water introduction port 46. It has become.

  As shown in FIG. 8, first, the cooling hollow member 30 is set in the mold 50 by fitting the water channel opening 16a of the water jacket projection 40 to the positioning pin 51b of the upper mold 51 to cool the mold. The hollow material 30 is positioned. Further, the cylinder liner 12a is held by the cylinder bore protrusion 51a. Thereby, the cooling hollow material 30 and the cylinder liner 12a are held in the upper mold 51.

  Thereafter, the upper mold 51 holding the cooling hollow material 30 and the cylinder liner 12a is set close to the fixed mold 52 and set at a predetermined position. Next, as shown in FIGS. 8 and 9, a slide mold 53 disposed on a plane parallel to the cylinder arrangement direction of the cylinder block 10 and a slide mold 54 disposed on a plane orthogonal to the cylinder arrangement direction of the cylinder block 10. Are respectively slid to predetermined positions to form cavities in the mold 50.

  Here, when the slide mold 54 is slid, the insertion pin 54 a provided in the slide mold 54 is inserted into the cooling water inlet 46 of the cooling hollow material 30 held by the upper mold 51. Accordingly, the cooling hollow material 30 is also positioned and held by the slide die 54. In this way, the cooling hollow material 30 is held in the mold 50 in a properly positioned state in the cavity of the mold 50.

  Then, in the casting process, the cylinder block 10 is die-cast by casting the cooling hollow material 30 held in the mold 50 by injecting and filling molten metal into the cavity of the mold 50. Here, the die-cast product improves the quality by improving the casting pressure and improves the quality. Therefore, when the casting pressure is lowered, the molding conditions deteriorate and a high-quality product (cylinder block) can be obtained. become unable. For this reason, in this Embodiment, the high pressure die-casting whose casting pressure is 50-80 Mpa is performed. Thereby, the quality of the cylinder block 10 is improved.

  Further, the cooling member 30 is provided with the connecting members 45 formed by the protrusions 37 and 38 in a distributed manner, thereby increasing the mechanical strength. In particular, in the present embodiment, the protrusions 37 and 38 have a symmetrical shape (the same shape). Thereby, in the projection part, the pressure of the molten metal received from the inner cylinder part 30a side of the cooling hollow member 30 can be made equal to the pressure of the molten metal received from the outer cylinder part 30b side. In the present embodiment, the metal plates 31, 32 and the bent portions 31a, 31b, 32a, 32b of the metal plates 33, 34 and the bent portions 33a, 33b, 34a, 34b are overlapped and joined. As a result, the mechanical strength at both ends (upper and lower ends) of the cooling hollow material 30 in the cylinder axial direction is increased. Therefore, deformation of the cooling hollow material 30 due to the pressure of the molten metal can be reliably prevented.

  Therefore, even if the cooling hollow material 30 is cast and high-pressure die casting is performed, the cooling hollow material 30 is not deformed and the cooling water passage is not partially blocked in the water jacket 16. Therefore, the water jacket 16 having a desired shape can be provided even if the cylinder block 10 is formed by high-pressure die casting without disposing a filler inside the cooling hollow material 30. Accordingly, the closed deck type cylinder block 10 can be manufactured by high-pressure die casting without reducing the productivity.

  Further, since the cooling hollow material 30 is firmly held in the mold 50 by the positioning pins 51b of the upper mold 51 and the insertion pins 54a of the slide mold 54, the cooling hollow material 30 is caused by the pressure of the molten metal during casting. The position of will not shift. Therefore, the position accuracy of the water jacket 16 in the cylinder block 10 can be increased.

  Further, since the positioning pin 51b and the insertion pin 54a are inserted into the water jacket projection 40 and the cooling water introduction port 46 of the cooling hollow material 30, respectively, the water jacket projection 40 and the cooling water introduction port 46 are deformed during casting. Intrusion of the molten metal into the water jacket projection 40 and the cooling water inlet 46 can be prevented.

  Further, a plurality of gas vent grooves 42 are formed in the recesses 37 a and 38 a of the protrusions 37 and 38 provided on the cooling hollow material 30. Accordingly, when the molten metal flows into the recesses 37a and 38a, the gas is efficiently vented by the plurality of gas vent grooves 42 provided in the recesses 37a and 38a. Thereby, generation | occurrence | production of a casting defect can be prevented.

  In the cylinder block 10 manufactured in this way, the inner side of the cooling hollow material 30 becomes the water jacket 16. Here, the connecting member 45 is disposed in the cooling hollow member 30. However, since the connecting member 45 is substantially circular and distributed, the flow of the cooling water in the water jacket 16 may be disturbed. Without being able to flow cooling water smoothly. For this reason, the provision of the connecting member 45 in the cooling hollow member 30 does not generate a separation flow in the cooling water, so that cavitation does not occur and the cooling effect of the cylinder block 10 does not deteriorate.

  As described above in detail, in the cylinder block 10 according to the present embodiment, the cooling hollow material 30 serving as the water jacket 16 is cast and formed by high pressure die casting. The cooling hollow member 30 is provided with a plurality of connecting members 45 (projections 37 and 38) that connect the inner wall surface of the inner cylinder part 30a and the inner wall surface of the outer cylinder part 30b. As a result, the mechanical strength of the cooling hollow member 30 can be greatly improved, and even in high-pressure die casting where the casting pressure is 50 to 80 MPa, the cooling hollow member 30 is deformed and the water jacket 16 has It is possible to prevent the cooling water passage from being partially blocked. Therefore, the water jacket 16 having a desired shape can be formed by high-pressure die casting without disposing a filler inside the cooling hollow material 30.

  Since the connecting members 45 are provided in a distributed manner, the flow of cooling water in the water jacket 16 can be prevented from being disturbed. That is, even if the connecting member 45 is provided in the cooling hollow member 30, the cooling water flows smoothly and no separation flow occurs, so that no cavitation occurs and the cylinder block 10 is cooled. The effect is not reduced.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the cooling hollow member 30 is formed of a plurality of metal plates, but the cooling hollow member 30 can be formed by processing a pipe member as shown in FIG. . Further, when the cooling hollow member 30 is formed of a metal plate, the number of metal plates to be used is not limited to four. For example, two metal plates (one inner metal part and one outer cylinder part each of one metal) It is also possible to use three metal plates (one inner plate portion is composed of one metal plate and outer cylinder portion is composed of two metal plates), or four or more metal plates.

  Further, in the above-described embodiment, the protrusions 37 and 38 have a substantially circular (ellipse) shape, but the shape is not limited to this, and any shape that does not generate a separation flow in the cooling water. It may be. For example, an ellipse can be formed as shown in FIG. 11, or a streamline can be formed as shown in FIG.

In the above-described embodiment, the connecting member 45 is formed by the protrusion 37 provided on the inner cylinder metal plates 31 and 32 and the protrusion 38 provided on the outer cylinder metal plates 33 and 34. It is also possible to provide projections only on the 31 and 32 or the outer cylindrical metal plates 33 and 34 and to form the connecting member 45 with the projections .

  In the above-described embodiment, the five gas vent grooves 42 arranged in parallel with the concave portions 37a and 38a of the projections 37 and 38 are provided. However, the arrangement, shape, and number of the gas vent grooves 42 are not limited thereto. Without being limited thereto, for example, as shown in FIGS. 13 and 14, the two gas vent grooves 42 may be arranged so as to intersect with each other.

  Furthermore, in the above-described embodiment, the case where the present invention is applied to an in-line four-cylinder engine is illustrated, but the present invention can also be applied to engines other than the in-line four-cylinder engine. For example, the present invention can be applied to an engine in which the number of cylinders is increased or decreased, such as V-type or horizontally opposed, and the number of cylinders.

It is a top view which shows schematic structure of the cylinder block which concerns on embodiment. It is sectional drawing in the II-II line of FIG. It is a perspective view which shows the water jacket in a cylinder block. It is a disassembled perspective view of the hollow material for cooling. It is the perspective view which showed the cross section of the hollow material for cooling. It is a figure which shows the degassing groove | channel formed in the recessed part of the processus | protrusion provided in the hollow material for cooling. It is sectional drawing in the VII-VII line of FIG. It is a figure which shows a mode that the hollow material for cooling was fixed to the upper mold | type. It is a figure which shows a mode that the insertion pin with which a slide type is equipped is inserted in a cooling water inlet. It is the perspective view which showed the cross section of the modification of the hollow material for cooling. It is a figure which shows the deformation | transformation shape of a processus | protrusion. It is a figure which shows the deformation | transformation shape of a processus | protrusion. It is a figure which shows the modification of a gas vent groove. It is sectional drawing in the XIV-XIV line | wire of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cylinder block 10a Upper deck surface 11 Cylinder bore 12 Cylinder 13 Block outer wall 14 Bridge 16 Water jacket 16a Water channel opening part 30 Cooling hollow material 30a Inner cylinder part 30b Outer cylinder part 31 Inner cylinder metal plate 31a Bending part 31b Bending part 32 Inner cylinder Metal plate 32a Bending part 32b Bending part 33 Outer cylinder metal plate 33a Bending part 33b Bending part 34 Outer cylinder metal plate 34a Bending part 34b Bending part 35 Connecting member 36 Water intake 37 Projection 38 Projection 39 Opening 40 Water jacket projection 41 Through hole 45 Connecting member 46 Cooling water inlet 50 Mold 51 Upper mold 51a Cylinder bore protrusion 51b Positioning pin 52 Fixed mold 53 Slide mold 54 Slide mold 54a Insertion pin

Claims (4)

In a closed deck type cylinder block comprising a plurality of cylinders in which pistons slide inside and a water jacket for circulating cooling water for cooling the cylinders,
The inner cylinder part and the outer cylinder part formed by bending both ends in the cylinder axial direction and having a U-shaped cross section are joined by overlapping the bent parts and arranged around the cylinder. A hollow member that forms a water jacket,
The hollow member has an inner wall surface of the inner cylinder portion and an inner wall surface of the outer cylinder portion by a protrusion provided on at least one of the inner cylinder portion or the outer cylinder portion so as to protrude inside the hollow member. A plurality of connecting members to be connected are provided in a dispersed manner ,
A closed deck type wherein a plurality of hollow water channel protrusions communicating with the hollow member are provided in the bent portion on the upper deck surface side facing the opening of the cylinder Cylinder block. In the closed deck type cylinder block according to claim 1 ,
The connecting member is formed by abutting the tip portions of the protrusions provided to protrude inside the hollow member on both the inner cylinder part and the outer cylinder part,
A closed deck type cylinder block characterized in that a protrusion provided on the inner cylinder part and a protrusion provided on the outer cylinder part are symmetrical. In the closed deck type cylinder block according to claim 1 or 2 ,
A closed deck type cylinder block having a cooling water inlet provided in an outer wall of the outer cylinder part for introducing cooling water into the hollow member. In a manufacturing method for manufacturing a cylinder block of a closed deck type including a plurality of cylinders in which pistons slide inside and a water jacket for circulating cooling water for cooling the cylinders by casting using a mold,
As an insert member for forming a water jacket disposed around the cylinder, a plurality of inner cylinder parts, outer cylinder parts, an inner wall surface of the inner cylinder part, and an inner wall surface of the outer cylinder part are connected. and distributed by a connecting member, and the hollow member forming step of forming a hollow member and a waterway projection of the middle empty shape,
An insertion protrusion formed on the mold is inserted into a hollow portion of the water channel protrusion of the hollow member formed in the hollow member forming step to hold the hollow member, and the hollow member is inserted into a cavity of the mold. A hollow member arrangement step of positioning and arranging
A casting step of die-casting a cylinder block by casting the hollow member held in the mold in the hollow member arranging step;
I have a,
In the hollow member forming step, the hollow member is formed by joining the inner cylinder part and the outer cylinder part formed by bending both ends in the cylinder axial direction so as to have a U-shaped cross section and overlapping the folded parts. In addition, a water channel protrusion is provided at the bent portion on the upper deck surface side facing the opening of the cylinder,
The closed member is characterized in that, in the hollow member forming step, the connecting member is formed by a protrusion provided on at least one of the inner cylinder part or the outer cylinder part so as to protrude inside the hollow member. Manufacturing method for deck type cylinder block.

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