JP2005133688A - Engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine capable of increasing degree of freedom in design by facilitating molding property of a part dividing and forming a water jacket and realizing a highly reliable structure easily. <P>SOLUTION: A part constituting a cylinder block 10 of the engine is composed of divided bodies divided into a cylinder block main body 4 constituting a wall face on a cylinder side and an outer side wall 6 surrounding the water jacket 50 using a section of the water jacket 50 as boundary. The outer side wall 6 is formed as a structural body integral with a cylinder head 7 provided in an upper part of the cylinder block main body 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine mounted on a vehicle or the like, and more particularly to improvement of a main body structure as the engine.

In general, in this type of engine, that is, a gasoline engine or a diesel engine, a water jacket for circulating cooling water is usually formed in the cylinder block so as to surround the cylinder. Conventionally, as an engine having a cylinder block structure in which such a water jacket is formed around a cylinder, there is an engine described in Patent Document 1, for example. In the engine described in the document, the cylinder wall and the water jacket wall are integrally formed, and the resin casing is attached to the portion where the thickness of the water jacket wall increases with a bolt to reduce the weight.
JP-A-5-296103

  By the way, if you do not want to cool the cylinder more than necessary from the viewpoint of flammability because of sufficient cooling capacity with cooling water, or if you want to reduce the size of the engine or reduce the weight mentioned above, It is desirable to form it narrowly.

  In this regard, as in Patent Document 1, in the case where the water jacket is integrally formed in the cylinder block by casting, in order to reduce the width of the water jacket, the casting mold of the portion for forming the water jacket is also used. It is necessary to make it thinner.

  However, if such a thin part is provided in the casting mold, the mold part of the water jacket tends to be easily damaged or worn during the casting of the cylinder block, which causes a problem that the mold life is shortened. That is, there is a limit to reducing the thickness of the water jacket mold. For this reason, the water jacket inevitably has a certain size in the width direction, and the degree of freedom of the shape in the width direction is naturally low. As a result, the overall size of the engine is increased, or inconveniences such as overcooling and overheating of the cylinder are likely to occur.

  The present invention has been made in view of such circumstances, and the object thereof is to facilitate the formability of the portion forming the water jacket to increase the degree of freedom of design, and thus to facilitate a more reliable structure. It is to provide an engine that can be realized.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is formed by dividing a cylinder block body constituting a wall surface on the cylinder side and an outer wall surrounding the portion to be the water jacket, with the portion to be the water jacket as a boundary, and The gist of the invention is that the outer wall is an engine formed integrally with a cylinder head disposed on the upper portion of the cylinder block body.

  According to a second aspect of the present invention, there is provided a cylinder block main body that forms a wall surface on the cylinder side with respect to a portion that is a water jacket, and an outer wall that surrounds the portion that is the water jacket. The gist of the present invention is an engine including a cylinder head provided on the upper portion.

  According to a third aspect of the present invention, the portion constituting the cylinder block is divided into a cylinder block main body constituting the wall surface on the cylinder side and an outer wall surrounding the water jacket, with a portion to be the water jacket as a boundary. The gist of the present invention is that the outer wall is formed as a structure integrated with a cylinder head provided on the upper portion of the cylinder block body.

  In any of the first to third aspects of the present invention, the cylinder-side wall surface defining the water jacket and the outer side wall are separately formed. For this reason, when forming each wall surface, especially when forming by casting, it is not necessary to make the mold part for forming the water jacket thin in the casting mold. In other words, the casting die of the cylinder block main body only needs to be molded on the surface of the portion corresponding to the inside of the water jacket, and therefore the casting die itself can be made sufficiently thick regardless of the width of the water jacket. it can. Similarly, when casting the outer wall, the surface of the portion corresponding to the outer side of the water jacket may be formed in the casting mold, so the width direction of the casting mold itself is related to the width of the water jacket. It can be made thick enough. Thus, even when the width of the water jacket is narrowed, the casting molds themselves can be formed thick, so that deterioration of the mold life is suppressed. Moreover, in any of these engines, the outer wall is formed as a structure integrally formed with the cylinder head. Therefore, compared to the case where the outer wall and the cylinder head are formed separately, for example, the number of casting molds, the number of assembly steps of the engine, and the like can be eliminated. As a result, the manufacturing cost can be reduced, the moldability of the section for forming the water jacket can be made easy, the degree of freedom in design can be increased, and an engine having a highly reliable structure can be easily realized. Will be able to.

Also,
According to a fourth aspect of the present invention, in the engine according to any one of the first to third aspects, the cylinder block body and the cylinder head are fastened and fixed by a bolt inserted in an axial direction of the cylinder. It becomes the gist.

  In this configuration, the cylinder block body and the cylinder head are fastened and fixed by bolts inserted in the axial direction of the cylinder. Therefore, in the combustion / compression stroke, a force that pushes the cylinder head upward acts, and even if a force that pushes the cylinder block body downward acts, these forces are applied to the cylinder wall and the outside of the cylinder block body via the bolts. It does not act on the wall, so that it is possible to improve the reliability against deformation of the cylinder.

  According to a fifth aspect of the present invention, in the engine according to any one of the first to fourth aspects, the cylinder block body is provided with a surface joined to the bottom surface of the outer wall, and the cylinder block The gist of the present invention is that the joint surface between the main body and the outer wall is provided with positioning means for positioning the joint positions.

  According to this configuration, since the positioning means is formed, the cylinder block body and the outer wall can be quickly and accurately combined. That is, the manufacturing cost can be reduced also by this.

  According to a sixth aspect of the present invention, in the engine according to any one of the first to fifth aspects, the cylinder block body is formed by casting using one of an aluminum alloy and a magnesium alloy. The gist.

According to this configuration, the engine can be further reduced in weight.
The gist of the invention according to claim 7 is that, in the engine according to claim 6, a cylinder liner is cast into a bore portion of the cylinder block body.

  According to this configuration, the cylinder liner is cast into the cylinder block body that is a casting. Therefore, it is possible to reduce the wall thickness while ensuring the strength (wear resistance) as a cylinder liner, and to reduce the weight as the engine.

  The gist of the invention according to claim 8 is that, in the engine according to claim 6, the bore portion of the cylinder block body is subjected to a surface treatment for imparting wear resistance.

According to this configuration, it is possible to ensure the wear resistance without casting a cylinder liner into the cylinder block body, and it is possible to further reduce the weight of the engine.
The invention according to claim 9 is the engine according to any one of claims 1 to 8, wherein the cylinder head is formed by casting using any one of an aluminum alloy and a magnesium alloy. The gist.

  This configuration also makes it possible to reduce the weight of the engine. In particular, according to the combination with the inventions described in claims 6 to 8, the weight reduction can be further promoted.

Hereinafter, an embodiment of an engine according to the present invention will be described in detail with reference to FIGS.
FIG. 1 shows the external structure of an in-line four-cylinder engine that is an engine according to this embodiment. As shown in an exploded perspective view in FIG. 2, this engine is configured by dividing a cylinder block body 4 and a cylinder head portion 8 formed of an integral structure of an outer wall 6 of the cylinder block and a cylinder head 7.

  Here, the cylinder block body 4 is integrally cast from an aluminum alloy or a magnesium alloy. As shown in FIG. 2, the cylinder block body 4 is provided in the middle of the four cylinders 12 provided in the upper portion, the skirt 14 provided in the lower portion, and the cylinder 12 and the skirt 14. The outer wall placing portion 16 is provided. A plurality of ribs 18 and 20 for reinforcement are provided outside the skirt 14 and the outer wall mounting portion 16.

  A cylinder liner 22 is cast on the inner peripheral surface side of each cylinder 12 at a portion where a bore is formed. As the cylinder liner 22, a material having high wear resistance such as an iron alloy having a specific gravity higher than that of an aluminum alloy or a magnesium alloy is used.

  On the other hand, a mounting surface 24 orthogonal to the axial direction of the cylinder 12 is formed on the outer wall mounting portion 16 so as to surround all the cylinders 12. Further, on the mounting surface 24, bolt screw holes 26 are provided at 10 positions around the cylinder 12. Similarly, on the mounting surface 24, knock pins 28 for positioning the outer wall 6 are provided so as to protrude at two diagonal positions.

  On the other hand, as shown in FIG. 3 and as described above, the cylinder head portion 8 has a structure in which the cylinder head 7 disposed on the upper portion of the cylinder block body 4 and the outer wall 6 of the cylinder block are integrally formed. Has been.

  Here, the outer wall 6 has an inner peripheral surface 30 that forms a water jacket, which will be described later, facing the outer peripheral wall surface 12a (see FIG. 2) of the cylinder 12, and is formed in an annular shape. The inner peripheral surface 30 includes an upper inner peripheral surface 30a and a lower inner peripheral surface 30b. The lower inner peripheral surface 30b is closer to the outer peripheral wall surface 12a of the cylinder 12 than the upper inner peripheral surface 30a. It is molded with a predetermined level difference. Further, a cooling water port 44 used for inflow or outflow of cooling water to / from the plurality of ribs 40 and 42 and the water jacket is provided on the outer periphery of the outer wall 6. The cylinder head portion 8 is also cast from an aluminum alloy or a magnesium alloy. Further, bolt insertion holes 36 are formed through the cylinder head portion 8 at ten locations along the axial direction of the inner peripheral surface 30. These bolt insertion holes 36 are provided corresponding to the ten bolt screw holes 26 provided in the cylinder block body 4.

  FIG. 4 shows a bottom view of such a cylinder head portion 8. As shown in FIG. 4, a flat bottom surface 34 is formed at the lower end of the cylinder head portion 8 (outer wall 6), and the above-described knock pin 28 on the cylinder block body 4 side is inserted into the bottom surface 34. The positioning hole 38 is formed at a position corresponding to the knock pin 28 on the cylinder block body 4 side. Note that a metal sheath tube may be separately provided in the bolt insertion hole 36.

  With such a configuration, as shown in FIG. 1, the cylinder block body 4 and the outer wall 6 formed integrally with the cylinder head 7 are separated from the knock pin 28 on the cylinder block body 4 side and the positioning hole 38 on the outer wall 6 side. And combined by positioning. The knock pin 28 and the positioning hole 38 are provided on the joint surface between the cylinder block body 4 and the outer wall 6 to constitute a positioning means for positioning the joint position.

  And the engine of this embodiment combined in this way, as shown in the longitudinal section of the cylinder part in FIG. 5, the outer peripheral wall surface 12 a of the cylinder 12 in the cylinder block body 4 and the inner peripheral surface 30 of the outer wall 6. A water jacket 50 is formed therebetween, and the outer peripheral wall surface 12a and the inner peripheral surface 30 face each other with the water jacket 50 interposed therebetween. And the upper inner peripheral surface 30a side is lower inner peripheral surface 30b side by the above-mentioned level | step difference among the inner peripheral surfaces 30 of the outer side wall 6 so that a bigger cooling effect may be acquired by the side near the combustion chamber of the cylinder 12. The width of the water jacket 50 is set to be larger than that of FIG.

  In this embodiment, as described above, the portion constituting the cylinder block 10 of the engine is the outer side surrounding the water jacket 50 and the cylinder block body 4 constituting the wall surface on the cylinder 12 side with the water jacket 50 as a boundary. It is comprised from the division body divided | segmented into the wall 6. FIG. Further, the outer wall 6 is formed as a structure integrated with a cylinder head 7 provided on the upper portion of the cylinder block body 4.

  Incidentally, as shown in FIG. 5 or FIG. 2, the gasket 11 is sandwiched between the inner peripheral deck surface 12b at the upper end of the cylinder 12 in the cylinder block body 4 and the cylinder head 7. Airtightness in the cylinder is ensured.

  Further, a liquid sealing material (for example, a silicon-based sealing material) is applied in advance to one or both of the mounting surface 24 of the cylinder block body 4 and the bottom surface 34 of the outer wall 6. Thereby, the space between the placement surface 24 and the bottom surface 34 is sealed, and water leakage from the water jacket 50 is prevented. Note that a gasket may be provided instead of the liquid sealing material.

  Further, when the outer wall 6 is made of a metal such as an aluminum alloy or a magnesium alloy, welding for sealing purposes (for example, TIG welding, MIG welding, laser welding, friction stir welding, etc.) may be performed. That is, as shown in FIG. 5, welding is performed from the outer peripheral side to the boundary portion between the cylinder block body 4 and the outer wall 6 in a state where the mounting surface 24 of the cylinder block body 4 and the bottom surface 34 of the outer wall 6 are in contact with each other. You may give it.

  Then, as shown in a longitudinal sectional perspective view between the cylinders in FIG. 6, fastening bolts 52 are respectively inserted into the bolt insertion holes 36 of the cylinder head portion 8, and these fastening bolts 52 are screwed into the bolt screw holes 26 of the cylinder block body 4. Entered. As a result, the cylinder block body 4 and the cylinder head portion 8 are fastened and fixed by the fastening bolts 52.

  In this embodiment, the cylinder block main body 4 and the cylinder head portion 8 are fastened with the fastening bolts 52 inserted in the axial direction of the cylinder 12 in this way. Therefore, in the combustion / compression stroke, a force that pushes up the cylinder head portion 8 acts, and even when a force that pushes down the cylinder block body 4 acts, these forces are applied to the cylinder 12 and the It does not act on the outer side wall 6, so that a decrease in reliability as an engine can be suppressed. Further, since the axial direction of the fastening bolt 52 and the direction in which the force is applied are substantially parallel, deformation of the bolt screw hole 26 and the bolt insertion hole 36 is also suppressed.

As described above, according to the engine according to the present embodiment, the following effects can be obtained.
(1) At least a portion constituting the cylinder block 10 is divided into the cylinder block body 4 and the outer wall 6 with the water jacket 50 interposed therebetween. For this reason, when forming the cylinder block main body 4 and the outer wall 6, especially when molding the cylinder block main body 4 and the outer wall 6 by casting, the mold portion for forming the water jacket 50 as a casting mold is thinly formed. There is no need to do it. That is, since the casting molds of the cylinder block body 4 and the outer wall 6 only need to form the inner and outer surfaces of the water jacket 50, the width direction of the casting mold itself is sufficient regardless of the width of the water jacket 50. Can be thicker. For this reason, deterioration of the mold life can be suitably suppressed. In addition, since the wall surface on the cylinder 12 side and the outer wall 6 forming the water jacket 50 are separately formed, the formability of the portion forming the water jacket 50 is facilitated. That is, the degree of freedom in designing them is increased, and as a result, an engine having a highly reliable structure can be easily realized.

  (2) Since the cylinder block main body 4 and the outer wall 6 are formed separately, the interiors of the casting molds do not have a complicated shape, and the structure can be simplified. For this reason, the molten metal flows smoothly in the casting mold at the time of casting, so that a cast hole or the like hardly occurs in the cast product. That is, the cylinder block body 4 and the outer wall 6 can be manufactured with a high yield, and the manufacturing cost can be reduced.

  (3) Moreover, the outer wall 6 and the cylinder head 7 are formed as an integral structure as the cylinder head portion 8. Therefore, compared with the case where the outer wall 6 and the cylinder head 7 are formed separately, the number of casting dies, the number of assembling steps of the engine, and the like can be reduced. Also in this respect, the manufacturing cost can be reduced as a result. be able to.

  (4) As shown in FIG. 2, the cylinder 12 of the cast cylinder block body 4 is completely exposed. For this reason, various processing (for example, screw processing, processing for cooling between bores) for the cylinder 12 from the inner peripheral surface and the outer peripheral surface, processing for the cylinder liner 22 from the inner peripheral surface and the outer peripheral surface, and processing around the cylinder 12 Can be easily performed. Similarly, various types of processing can be easily performed on the inner peripheral surface 30 of the outer wall 6. For these reasons, the water channel formation of the water jacket 50 has a very high degree of freedom, and the temperature around the bores and between the bores can be easily adjusted. In other words, the temperature distribution around the bores and between the bores can be optimized to control the shape distortion of the bore and the influence on combustion, and the engine performance can be made more suitable.

  (5) A knock pin 28 is provided on the mounting surface 24 of the cylinder block body 4 and a positioning hole 38 is provided on the bottom surface 34 of the outer wall 6. Therefore, the outer wall 6 can be easily and accurately arranged with respect to the mounting surface 24 of the cylinder block body 4. That is, the manufacturing cost can be reduced also by this.

(6) The cylinder block body 4 and the cylinder head portion 8 are cast from an aluminum alloy or a magnesium alloy. For this reason, weight reduction of an engine can be achieved.
(7) The cylinder liner 22 is cast into the cylinder block body 4. As a result, the durability of the cylinder 12 is improved, and the cylinder liner 22 itself can be thin. This can also contribute to weight reduction of the engine.

  (8) The cylinder block body 4 and the cylinder head portion 8 are fixed by the fastening bolts 52 inserted into the bolt insertion holes 36. That is, the cylinder block body 4 and the cylinder head portion 8 are fastened by the fastening bolts 52 inserted in the axial direction of the cylinder 12. Therefore, in the combustion / compression stroke, a force that pushes up the cylinder head portion 8 acts, and even if a force that pushes down the cylinder block body 4 acts, these forces are applied to the cylinder 12 and the outside via the fastening bolts 52. It does not act on the wall 6, so that it is possible to suppress a decrease in reliability against deformation or the like of the cylinder.

In addition, the said embodiment can also be changed and implemented as follows.
-A water jacket may be formed in the aspect extended above the inner peripheral deck surface 12b of the cylinder 12 so that the water jacket shown by the said embodiment may function also as a water jacket of the cylinder head 7. FIG. That is, for example, as shown in FIG. 7 as a cross-sectional view corresponding to FIG. 5, the cylinder head portion 8 in the above embodiment may be changed to a cylinder head portion 8 ′ shown in FIG. The cylinder head portion 8 'is formed with a groove 60 through which cooling water flows inside a cylinder head 7' constituting a part of the cylinder head portion 8 '. The groove 60 is formed between the cylinder head portion 8' and the cylinder block body 4. When combined, it becomes part of the water jacket 50 '. Even with such a structure, it is possible to obtain the same effect as or equivalent to that of the above embodiment, and to further promote the cooling effect on the cylinder head side.

  In the above embodiment, as described above, since the cast block is less likely to occur in the cylinder block body 4, defects due to the cast hole are less likely to occur on the inner peripheral surface of the cylinder 12. For this reason, a sufficiently smooth surface can be formed as a bore by surface treatment such as thermal spraying. Therefore, the casting of the cylinder liner 22 into the cylinder 12 of the cylinder block body 4 may be omitted, and the inner peripheral surface of the cylinder 12 may be subjected to surface treatment such as thermal spraying to provide wear resistance. In this case, the manufacturing cost can be further reduced, and the weight of the entire engine can be further reduced.

  In the above embodiment, the outer wall 6 is positioned with respect to the cylinder block body 4 by engaging the two knock pins with the two positioning holes. However, the knock pins 28 and the positioning holes 38 are further increased. Also good. Further, the positioning means may be constituted by means other than the combination of the knock pin 28 and the positioning hole 38. For example, you may make it provide the frame etc. in which the bottom part of the outer side wall 6 is accommodated in the outer peripheral surface of the cylinder block main body 4. FIG.

-You may make it form the cylinder block main body 4 and the cylinder head part 8 with cast iron.
In addition, the technical idea that can be grasped from the above embodiment will be described below together with the effects thereof.

(A) An engine cylinder head in which an outer wall surrounding a water jacket formed in a cylinder block of an engine is formed as an integral structure.
According to such a cylinder head, the same effect as that of the engine according to the first to third aspects can be obtained by adopting the cylinder head.

  (B) The engine cylinder head according to (a), wherein the cylinder head is formed by casting using one of an aluminum alloy and a magnesium alloy.

  According to such a cylinder head, the suitable weight reduction comes to be achieved.

1 is a perspective view showing an embodiment of an engine according to the present invention. The disassembled perspective view of the engine concerning the embodiment. The fragmentary broken perspective view of the cylinder head part in the embodiment. The bottom view of the cylinder head part in the embodiment. Sectional drawing cut | disconnected along the axis | shaft of a cylinder about the engine concerning the embodiment. The partially broken perspective view cut | disconnected between cylinders about the engine concerning the embodiment. Sectional drawing cut | disconnected along the axis | shaft of a cylinder about the modification of the engine concerning the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 4 ... Cylinder block main body, 6 ... Outer wall, 7, 7 '... Cylinder head, 8, 8' ... Cylinder head part, 10 ... Cylinder block, 11 ... Gasket, 12 ... Cylinder, 12a ... Outer peripheral surface, 12b ... Inner circumference Deck surface, 14 ... skirt, 16 ... outer wall mounting portion, 18, 20 ... rib, 22 ... cylinder liner, 24 ... mounting surface, 26 ... bolt screw hole, 28 ... knock pin, 30 ... inner peripheral surface, 30a ... inside upper part Peripheral surface, 30b ... lower inner peripheral surface, 34 ... bottom surface, 36 ... bolt insertion hole, 38 ... positioning hole, 40, 42 ... rib, 44 ... cooling water port, 50, 50 '... water jacket, 52 ... fastening bolt, 60 …groove.

Claims (9)

The cylinder block main body constituting the cylinder side wall and the outer wall surrounding the water jacket portion are divided with the water jacket portion as a boundary, and the outer wall is an upper portion of the cylinder block main body. An engine formed integrally with a cylinder head arranged in the engine. A cylinder block body constituting a wall surface on the cylinder side with respect to a portion to be a water jacket;
A cylinder head provided on an upper portion of the cylinder block body having an outer wall surrounding a portion to be the water jacket;
An engine equipped with. The cylinder block part is an engine composed of a divided body divided into a cylinder block main body that forms a wall surface on the cylinder side and an outer wall that surrounds the water jacket, with a portion to be a water jacket as a boundary,
The engine, wherein the outer wall is formed as a structure integrated with a cylinder head provided at an upper portion of the cylinder block body. The engine according to any one of claims 1 to 3,
The engine, wherein the cylinder block body and the cylinder head are fastened and fixed by a bolt inserted in an axial direction of the cylinder. In the engine according to any one of claims 1 to 4,
The cylinder block main body is provided with a surface to be joined to the bottom surface of the outer wall, and the joining surface between the cylinder block main body and the outer wall is provided with positioning means for positioning the mutual joining position. An engine characterized by that. In the engine according to any one of claims 1 to 5,
The engine, wherein the cylinder block body is formed by casting using either an aluminum alloy or a magnesium alloy. The engine according to claim 6, wherein a cylinder liner is cast into a bore portion of the cylinder block body. The engine according to claim 6, wherein the bore portion of the cylinder block body is subjected to a surface treatment that imparts wear resistance. The engine according to any one of claims 1 to 8,
The engine is characterized in that the cylinder head is formed by casting using either an aluminum alloy or a magnesium alloy.

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