JP6569725B2 - Multi-cylinder engine - Google Patents

Description

  The present invention relates to a multi-cylinder engine, and more particularly to a structure of a side wall surface in a cylinder block.

  BACKGROUND ART An engine such as a vehicle includes a cylinder block formed with cylinders, a cylinder head attached above the cylinder block, and an engine output shaft supported at the lower part of the cylinder block. The cylinder block and the cylinder head are fastened using a plurality of head bolts.

  By the way, high sealing performance is required for the contact portion between the cylinder block and the cylinder head. This is to prevent gas leakage, coolant leakage, oil leakage, and the like at that portion.

  In Patent Document 1, ribs are provided on the side wall surface of the cylinder block, and compressive stress due to the fastening of the head bolt is transmitted to the region between the head bolts by the rib, and thereby, between the cylinder block and the cylinder head. We are trying to improve the sealing performance.

Japanese Utility Model Publication No. 03-114557

  By the way, when the engine is driven, a load in the cylinder axial direction is applied to the cylinder block. This is due to the fact that the piston moves up and down in the cylinder and the engine output shaft rotates accordingly.

  The load proposed in the cylinder axis direction accompanying the rotation of the engine output shaft is not considered at all in the technique proposed in Patent Document 1. Therefore, in the technique proposed in Patent Document 1, a load is locally applied to a part of the cylinder block due to the rotation of the engine output shaft when the engine is driven, and the gas from the contact portion between the cylinder block and the cylinder head is detected. There is a concern that leakage or coolant leakage may occur.

  However, increasing the thickness of the cylinder block in order to suppress the above-described gas leakage and coolant leakage should increase the weight of the engine and must be avoided as much as possible.

  The present invention has been made to solve the above-described problems, and it is possible to ensure high sealing performance by suppressing the local application of a load accompanying rotation of the engine output shaft during driving. An object of the present invention is to provide a multi-cylinder engine capable of suppressing an increase in weight.

A multi-cylinder engine according to an aspect of the present invention includes an engine output shaft of the multi-cylinder engine, each extending in a direction orthogonal to the engine output shaft, each forming a cylinder and continuously forming each other three or more cylinders forming part which is, in the engine output shaft direction, a connecting portion for connecting the cylinder forming portion adjacent a plurality of arranged below the cylinder forming part of the cylinder axis a connecting portion for each of said plurality of connecting portions, with and extends toward the lower side side in the cylinder axis direction, a plurality of engine output shaft supporting portion having a portion for supporting the engine output shaft The side wall surface of at least one of the three or more cylinder forming portions has a base end at each of the connecting portions on both sides in the engine output shaft direction of the cylinder forming portion, respectively. Said mind Extend obliquely upward with respect to the axial direction, having two first ribs intersecting each other.

  In the multi-cylinder engine according to the above aspect, the two first ribs having the base ends at the connection portions on both sides thereof are provided on the side wall surface of at least one cylinder forming portion. The two first ribs intersect each other. For this reason, in the multi-cylinder engine according to the above aspect, when the engine output shaft supported by the engine output shaft support portion rotates, the load input in the cylinder axis direction to the engine output shaft support portion is connected to both sides. Is transmitted to the two first ribs and dispersed in the circumferential direction of the side wall surface in the cylinder forming portion. Therefore, in the multi-cylinder engine according to the above aspect, high sealing performance can be ensured by dispersing the load accompanying the rotation of the engine output shaft.

  Further, since the two first ribs are provided so as to intersect with each other, the loads transmitted through the first ribs are once gathered at the intersection. For this reason, even when there is a difference in the load transmitted between the two first ribs, the load is equalized by once gathering at the intersection, and the circumferential direction of the side wall surface in the cylinder forming portion To be distributed.

  Further, in the multi-cylinder engine according to the above aspect, since the load can be dispersed by forming the first rib, the thickness of the portion other than the first rib in the cylinder forming portion is increased in order to cope with the load. There is no need, and an increase in weight can be suppressed.

  Therefore, in the multi-cylinder engine according to the above aspect, it is possible to prevent a load from being locally applied to the cylinder block at the time of driving to ensure high sealing performance and to suppress an increase in weight.

  In the above aspect, the vertical direction is defined based on the direction related to the reciprocating motion of the piston in the cylinder. This is the same in the following embodiments.

  A multi-cylinder engine according to another aspect of the present invention is the above-described aspect, wherein a side wall surface of the cylinder forming portion having the first rib is defined from a direction orthogonal to both the cylinder axis direction and the engine output axis direction. When viewed from the side, the portion where the two first ribs intersect is located on the central axis of the cylinder of the cylinder forming portion.

  In the multi-cylinder engine according to the above aspect, since the location where the two first ribs intersect is defined on the central axis of the cylinder in a side view, the load distributed by the two first ribs is the cylinder. It is evenly distributed in the circumferential direction of the side wall surface in the formation part.

  The multi-cylinder engine according to another aspect of the present invention is the above aspect, further comprising a cylinder head attached to the three or more cylinder forming portions in the cylinder axial direction, and the two first ribs The location where the two intersect with each other is a location below the mating surface with the cylinder head in the cylinder forming portion.

  In the multi-cylinder engine according to the above aspect, the location where the first ribs intersect is a location below the mating surface with the cylinder head in the cylinder forming portion. Stress concentration in the circumferential direction can be suppressed. That is, if the first rib extends to the mating surface, stress concentrates on the end of the first rib, and as a result, the circumferential surface of the side wall surface in the cylinder forming portion of the mating surface. This causes non-uniform pressure and leads to a decrease in sealing performance.

  On the other hand, in the multi-cylinder engine according to the above aspect, the portion where the first ribs intersect is a portion below the mating surface with the cylinder head in the cylinder forming portion, so the surface around the cylinder in the mating surface The occurrence of non-uniform pressure can be suppressed, and high sealing performance can be ensured.

  The multi-cylinder engine according to another aspect of the present invention is the above aspect, further comprising a cap portion connected to each of the plurality of engine output shaft support portions below in the cylinder axis direction, wherein the engine The output support portion and the cap portion are portions corresponding to the diameter center in the cylinder axis direction of the engine output shaft, and are connected so as to sandwich the engine output shaft, and the three or more cylinder forming portions The plurality of connection portions and the plurality of engine output support portions constitute a cylinder block.

  In the multi-cylinder engine according to the above aspect, since the engine output shaft is supported by the engine output shaft support portion and the cap portion, the engine output shaft can be easily assembled to the cylinder block when the engine is assembled. it can.

A multi-cylinder engine according to another aspect of the present invention is the above aspect, further comprising a plurality of head bolts for attaching the cylinder head to the cylinder block, wherein the cylinder block is adjacent to the engine output shaft direction. In each of the portions where the matching cylinder forming portions are connected to each other, the cylinder head has a first head bolt hole that penetrates from the mating surface to the lower end in the cylinder axial direction and through which the head bolt is inserted. Is continuous with the plurality of first head bolt holes and has a plurality of second head bolt holes through which the head bolts are inserted, and each of the plurality of cap portions is continuous with the first head bolt holes. A screw hole screwed to the head bolt, and each of the plurality of head bolts includes the first head bolt hole and the head bolt. The second head bolt hole is inserted and screwed into the female screw of the screw hole, and the cylinder block is tightly sandwiched between the cylinder head and the cap portion by the screwing. .

  In the multi-cylinder engine according to the above aspect, the cylinder block is sandwiched between the cylinder head and the cap portion by screwing the head bolt and the screw hole of the cap portion. In such a state, high compressive stress is likely to act around the portion through which the head bolt is inserted. However, in the multi-cylinder engine according to the above aspect, a plurality of first ribs are provided on the side wall surface of the cylinder forming portion. As a result, the load is dispersed and stress concentration is avoided. Therefore, in the multi-cylinder engine according to the above aspect, an increase in weight can be suppressed while ensuring high sealing performance.

  The multi-cylinder engine according to another aspect of the present invention is the above-described aspect, wherein the plurality of cap portions are not connected to each other at lower ends in the cylinder axial direction, and each of the lower ends is a free end. Is in a state.

  In the multi-cylinder engine according to the above aspect, the lower end portion of the cap portion is a free end, and the load (vertical load) in the cylinder axis direction accompanying the rotation of the engine output shaft is transmitted to the connection portion. Even in this case, in the multi-cylinder engine according to the above aspect, by providing the two first ribs intersecting each other on the side wall surface of the cylinder forming portion, it is possible to achieve the dispersion of the compressive stress and ensure high sealing performance. be able to.

A multi-cylinder engine according to another aspect of the present invention is an engine output shaft of the multi-cylinder engine, each extending in a direction orthogonal to the engine output shaft, each of which forms a cylinder. In addition, a plurality of connecting portions arranged at a lower portion in the cylinder axial direction in a portion where the three or more cylinder forming portions continuously formed with each other and the adjacent cylinder forming portions connected in the engine output shaft direction are connected. And a plurality of engine output shaft support portions that extend toward the lower side in the cylinder axis direction with respect to each of the plurality of connection portions and have a portion that supports the engine output shaft. And the side wall surface of at least one of the three or more cylinder forming portions has a base end at each of the connecting portions on both sides of the cylinder forming portion in the engine output shaft direction. Extend obliquely upward with respect to the cylinder axial direction, has two first ribs intersecting each other, the cylinder forming part having said first ribs, among the three or more cylinders forming portion, said engine An inner cylinder forming portion excluding end cylinder forming portions at both ends in the output shaft direction, and extending downward from each outer portion of the end cylinder forming portion in the cylinder axial direction; and the engine Two end engine output shaft support portions having a portion for supporting the output shaft are further provided, and each side wall surface of the two end engine output shaft support portions has a second rib extending in the cylinder axis direction.

  In the multi-cylinder engine according to the above aspect, since the second rib, which is a longitudinal rib, is formed on the side wall surface of the end engine output shaft support portion, the end engine output shaft support portion accompanying the rotation of the engine output shaft is formed. Even when a bending stress with the upper end portion of the shaft as a fulcrum is applied, deformation of the end engine output shaft support portion in the bending direction (elastic deformation and plastic deformation) is suppressed by the formation of the second rib.

  A multi-cylinder engine according to another aspect of the present invention is the above-described aspect, formed using a resin material, and the three or more cylinder forming portions, the plurality of connection portions, and the plurality of engine output shaft support portions. And a cylinder block outer wall that surrounds from the outside.

  Since the multi-cylinder engine according to the above aspect includes the cylinder block outer wall formed using a resin material, the weight of the engine can be reduced as compared with the case where the entire cylinder block is formed using a metal material. Moreover, high sealing performance can be ensured by forming the first rib on the side wall surface of the cylinder forming portion while reducing the weight by using the cylinder block outer wall made of the resin material.

  In the multi-cylinder engine according to each of the above-described aspects, it is possible to suppress a local load due to the rotation of the engine output shaft during driving, and to ensure high sealing performance at the mating surface with the cylinder head in the cylinder block. In addition, the weight increase can be suppressed.

1 is a schematic front view (partially sectional view) showing a schematic configuration of an engine according to an embodiment. It is a model side view which shows schematic structure of an engine. It is a figure which shows the III-III cross section of FIG. 2, Comprising: It is a schematic cross section which shows the attachment structure of a cylinder head, a block core, and a bearing cap. It is a model perspective view which shows the structure of a block core and a bearing cap. It is a model side view which shows the structure of a block core and a bearing cap. It is a model side view which expands and shows a part of FIG. It is a figure which shows the VII-VII cross section of FIG. 5, Comprising: It is a schematic cross section which shows the structure of a block core and a bearing cap. It is a schematic diagram which shows the transmission form of the load from a shaft support part to a cylinder formation part. It is a model perspective view which shows the structure of the cylinder formation part and shaft support part in a X direction edge part. It is a schematic diagram for demonstrating the role which the longitudinal rib plays when a bending load is applied with respect to the shaft support part in the X direction end part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The form described below is one embodiment of the present invention, and the present invention is not limited to the following form except for the essential configuration.

  In the drawings used in the following description, the X direction is the engine output shaft direction, the Y direction is the intake / exhaust direction, and the Z direction is the cylinder shaft direction.

[Embodiment]
1. Schematic Configuration of Engine 1 A schematic configuration of the engine 1 will be described with reference to FIGS. 1 and 2.

  The engine 1 according to this embodiment employs a four-cylinder gasoline engine as an example. As shown in FIG. 1, as shown in FIG. 1, a cylinder block 10, a cylinder head 13, a head cover 14, and a bearing cap (cap portion) 15. A crankshaft (engine output shaft) 16 and an oil pan 17.

  The cylinder block 10 includes a block core 11 formed using a metal material and a cylinder block outer wall 12 formed using a resin material. The detailed configuration of the block core 11 will be described later.

  The cylinder block outer wall 12 is formed so as to surround the block core 11, the bearing cap 15, and a part of the crankshaft 16 from the outside, and an oil pan 17 is connected to the −Z side. In FIG. 1, although not shown in detail, a water jacket, which is a path through which the coolant flows, is formed on the cylinder block outer wall 12.

  The cylinder head 13 is attached to the + Z side of the cylinder block 10. Although not shown in FIG. 1, the cylinder head 13 is provided with a camshaft, intake / exhaust valves, intake / exhaust manifolds, and the like.

  The head cover 14 is attached to the + Z side of the cylinder head 13 and closes the + Z side opening of the cylinder head 13.

  The bearing cap (cap portion) 15 is attached to the −Z side of the block core 11 and supports the crankshaft 16 in a rotatable state with the block core 11.

  As shown in FIG. 2, the crankshaft 16 extends along the X direction. The crankshaft 16 includes a crank journal 16a supported by the block core 11 and the bearing cap 15, a crank arm 16b provided between the crank journals 16a adjacent in the X direction, and a pair adjacent to each other in the X direction. Crank pins 16c provided between the formed crank arms 16b, and counterweights 16d continuously formed on the crank arms 16b.

  A connecting rod (connecting rod) 18 is attached to each crank pin 16 c in a rotatable state, and a piston 19 is attached to the other end of the connecting rod 18. The piston 19 can reciprocate in each cylinder in the Z direction. The crankshaft 16 rotates as the piston 19 reciprocates.

2. Mounting Configuration of Cylinder Head 13, Block Core 11 and Bearing Cap 15 The mounting configuration of the cylinder head 13, block core 11 and bearing cap 15 will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view showing a III-III cross section of FIG. 2.

  As shown in FIG. 3, the block core 11 is provided with a plurality of head bolt holes 11a. The plurality of head bolt holes 11a are provided in a pair in the Y direction, and each penetrates in the Y direction both side portions (radially outer portions) of the bearing portion 11b through which the crankshaft 16 is inserted in the Z direction. It is provided in the state.

  The cylinder head 13 is also provided with a plurality of head bolt holes 13a. The plurality of head bolt holes 13 a of the cylinder head 13 are provided so as to be continuous with the head bolt holes 11 a of the block core 11. The plurality of head bolt holes 13a are also provided so as to penetrate each other in the Z direction.

  The bearing cap 15 has a portion where the crankshaft 16 is inserted (a portion that supports the crankshaft 16) on both sides in the Y direction (radially outer portion) of the bearing portion 15b. A plurality of screw holes 15a continuous to the bolt holes 11a are provided. The plurality of screw holes 15a are provided so as to penetrate each other in the Z direction.

  In the engine 1, a plurality of head bolts 20 are inserted into the head bolt hole 13 a and the head bolt hole 11 a from the + Z side of the cylinder head 13, and the screw portion 20 b provided at the tip portion on the −Z side is the bearing cap 15. It is screwed with the female screw of the screw hole 15a.

  As shown in FIG. 3, in the engine 1 according to this embodiment, the cylinder head 13, the block core 11, and the bearing cap 15 are fastened together by a head bolt 20. For this reason, in the engine 1, the cylinder head 13 and the block core 11 are sandwiched between the bolt head 20 a of the head bolt 20 and the screwed portion of the screw portion 20 b and the screw hole 15 a of the bearing cap 15. It is in a state. More specifically, the block core 11 is sandwiched between the cylinder block 13 and the bearing cap 15 in the Z direction.

  In FIG. 3, one section of the engine 1 (III-III section in FIG. 2) is illustrated as an example, but other fastening portions by the head bolt 20 have the same configuration.

3. Configuration of Block Core 11 and Bearing Cap 15 The configuration of the block core 11 and the bearing cap 15 will be described with reference to FIGS. FIG. 4 is a schematic perspective view showing the configuration of the block core 11 and the bearing cap 15, and FIG. 5 is a schematic side view.

  As shown in FIG. 4, the block core 11 in the cylinder block 10 includes four cylinder forming portions 111 to 114, three connecting portions 115 to 117, and five shaft support portions (engine output shaft support portions) 118 to 122. And having. In the block core 11, the four cylinder forming portions 111 to 114, the three connecting portions 115 to 117, and the five shaft support portions (engine output shaft support portions) 118 to 122 are integrally formed using a metal material. ing.

  Each of the four cylinder forming portions 111 to 114 has cylinders 123 to 126. The cylinders 123 to 126 are arranged in the X direction. In the following, among the four cylinder forming portions 111 to 114, the cylinder forming portions 111 and 114 at both ends in the X direction are described as end cylinder forming portions, and the cylinder forming portions 112 and 113 are described as inner cylinder forming portions. There is a case.

  In the block core 11, a plurality of head bolt holes 127 to 136 are provided so as to penetrate in the Z direction. Of the plurality of head bolt holes 127 to 136, head bolt holes 127, 129, 131, 133, and 135 are provided on the side wall on the + Y side of the block core 11, and the head bolt holes 128, 130, 132, 134 and 136 are provided on the side wall of the block core 11 on the −Y side.

  Further, the head bolt holes 129 to 134 are provided in a portion between adjacent cylinders 123 to 126 in the X direction, and the head bolt holes 127, 128, 135, 136 are formed in the cylinder 123, 126 is provided at both ends.

  In the Y direction, the head bolt hole 127 and the head bolt hole 128 make a pair, the head bolt hole 129 and the head bolt hole 130 make a pair, and the head bolt hole 131 and the head bolt hole 132 make a pair. The head bolt 133 and the head bolt 134 make a pair, and the head bolt 135 and the head bolt 136 make a pair.

  As shown in FIG. 5, the connecting portion 115 is provided at the −Z side portion of the adjacent portion (connecting portion) of the cylinder forming portion 111 and the cylinder forming portion 112 in the X direction, and the connecting portion 116 is in the X direction. Provided in a portion on the −Z side of an adjacent portion (connecting portion) between the cylinder forming portion 112 and the cylinder forming portion 113, and a connecting portion 117 is an adjacent portion (connecting) between the cylinder forming portion 113 and the cylinder forming portion 114 in the X direction. Part) on the -Z side.

  The shaft support portions 119 to 121 are extended from the −Z side portion of the connection portions 115 to 117 toward the −Z side, respectively.

  On the other hand, the shaft support portions 118 and 122 are extended from both outer sides of the cylinder forming portions 111 and 114 toward the −Z side in the X direction.

  In FIG. 5, only the −Y side wall surface of the block core 11 is illustrated, but the connection portion is formed with the same configuration on the opposite + Y side.

  As shown in FIG. 5, on the side wall surface of the block core 11, head bolt hole forming portions 137 to 139 are formed in the + Z side portions of the connecting portions 115 to 117. The head bolt hole forming portions 137 to 139 are portions protruding in a semi-cylindrical rib shape on the front side (-Y side) of FIG. The head bolt hole 130 is provided in the head bolt hole forming part 137, the head bolt hole 132 is provided in the head bolt hole forming part 138, and the head bolt hole 134 is provided in the head bolt hole forming part 139.

  In FIG. 5, only the −Y side wall surface of the block core 11 is illustrated, but the head bolt hole forming portion is formed with the same configuration on the + Y side which is the opposite side. .

  As shown in FIGS. 4 and 5, bearing caps 151 to 155 are attached to portions on the −Z side of the shaft support portions 118 to 122, respectively. These bearing caps 151 to 155 may be collectively referred to as “bearing cap 15”.

  In the following, among the five shaft support portions 118 to 122, the shaft support portions 118 and 122 at both ends in the X direction may be referred to as end shaft support portions (corresponding to end engine output shaft support portions). .

  The bearing caps 151 to 155 are attached to the shaft support portions 118 to 122 by fastening with the head bolt 20 as described with reference to FIG. Here, the compressive stress generated by fastening the head bolt 20 and the screw hole 15a of the bearing cap 15 (bearing caps 151 to 155) is applied to the + Z side.

4). Configuration of Side Wall Surface in Inner Cylinder Forming Units 112 and 113 The configuration of the side wall surface in inner cylinder forming units 112 and 113 will be described with reference to FIG. In FIG. 6, the inner cylinder forming portion 112 is illustrated as an example, but the side wall surface of the inner cylinder forming portion 113 has the same configuration.

  As shown in FIG. 6, on the side wall surface of the inner cylinder forming portion 112 (the wall surface on the front side in FIG. 6), an oblique rib (inclined upward) with respect to both the X direction and the Z direction ( (Corresponding to the first rib) 140 and 141 are provided.

The oblique rib 140 extends in the oblique direction (obliquely upward direction) on the + X side and toward the + Z side with the connection portion 115 as a base end. The oblique rib 141 extends in the oblique direction (obliquely upward direction) on the −X side and toward the + Z side with the connection portion 116 as a base end. In the block core 11 according to the present embodiment, the oblique rib 140 and the oblique rib 141 are based on the central axis (cylinder central axis) Ax ₁₁₂ extending in the Z direction of the cylinder 124 (see FIG. 4) included in the inner cylinder forming portion 112. Are formed in a line-symmetric relationship.

The oblique rib 140 and the diagonal rib 141, intersect at intersection _{P 1.} Intersection _{P 1} is positioned on the cylinder center axis _{Ax 112} in the inner cylinder forming portion 112. Further, intersection _{P 1} from the mating surface 11c of the cylinder head 13 in the block core 11 of the cylinder block 10 is located at a position spaced -Z side distance _{H 1.} In other words, the intersection _{P 1,} rather than the mating surface 11c located below (-Z side).

Diagonal rib 140 extends toward the on more obliquely from intersection P ₁ (+ A X side + Z side), is connected to the head bolt hole forming portion 138 at the connection point P _3. Diagonal rib 141 also extends toward the further diagonally from the intersection point P ₁ (a -X side + Z side), is connected to the head bolt hole forming portion 137 at the connection point P _2.

In the block core 11 according to the present embodiment, the connection locations P ₂ and P ₃ are located at locations separated from the mating surface 11 c of the block core 11 with the cylinder head 13 by a distance H ₂ on the −Z side. That is, the connection locations P ₂ and P ₃ are located below (−Z side) from the mating surface 11 c.

  In the block core 11, the oblique ribs 140 and 141 are formed in the same manner as described above on the side wall surface of the cylinder forming portion 112 located on the back side in FIG. The same applies to the cylinder forming unit 113.

5. Configuration of Bearing Caps 151 to 155 The configuration of the bearing caps 151 to 155 will be described with reference to FIGS. FIG. 7 is a schematic cross-sectional view showing a VII-VII cross section of FIG. 5.

  As shown in FIG. 6, each of the bearin caps 152 and 153 is attached to the shaft support portions 119 and 120 at the end on the + Z side. The lower end portions (end portions on the −Z side) 152a and 153a of the bearing caps 152 and 153 are not connected to the bearing caps 151 to 154 adjacent in the X direction, and are in a so-called free end state. It has become. The same applies to the other bearing caps 151, 154, and 155.

  The reason why the lower ends of the bearing caps 151 to 155 become free ends as described above is due to the adoption of the cylinder block outer wall 12 made of a resin material. That is, in this embodiment, the cylinder block outer wall 12 formed using a resin material is employed, and the bearing caps 151 to 155 are connected by beams in order to reduce the weight of the engine 1 (bearing beam, bearing cap bridge). , Ladder frames, etc.) are not used.

  Next, as shown in FIG. 7, the bearing cap 151 on the −X side is provided with a cavity 151 a in the −Z side portion. The hollow portion 151a is a hole that penetrates the bearing cap 151 in the plate thickness direction (X direction). The cavity 151a is configured as an oval or an ellipse in a front view from the X direction. Although not shown in FIG. 7, the + X side bearing cap 155 is also provided with a cavity having the same configuration.

  The bearing caps 152 and 153 are also provided with cavities 152b and 153b. The hollow portions 152b and 153b are also holes that penetrate the bearing caps 152 and 153 in the plate thickness direction (X direction). When viewed from the front in the X direction, the cavities 152b and 153b are configured with rounded isosceles triangles.

  Although not shown in FIG. 7, the bearing cap 154 is also provided with a cavity having the same configuration.

6). A transmission form of a load generated along with the rotation of the crankshaft 16 A transmission form of a load generated along with the rotation of the crankshaft 16 will be described with reference to FIG. FIG. 8 is a schematic diagram showing a load transmission form from the shaft support portions 119 and 120 to the inner cylinder forming portion 112.

As shown in FIG. 8, loads F _1U and F _2U and loads F _1L and F _2L are applied to the shaft support portions 119 and 120 according to the phase angle of the crankshaft 16 (not shown in FIG. 8). The loads F _1U and F _2U are compressive loads that work toward the + Z side, and the loads F _1L and F _2L are tensile loads that work toward the −Z side. Among these, the loads F _1L and F _2L which are tensile loads are such that the load acting on the bearing caps 152 and 153 from the crankshaft 16 is via the mating surfaces 11d of the shaft support portions 119 and 120 with the bearing caps 152 and 153. Acting on the shaft support portions 119 and 120.

The loads F _1U and F _2U and the loads F _1L and F _2L are transmitted from the shaft support portions 119 and 120 to the connection portions 115 and 116. Then, each of the loads F _1U and F _2U and the loads F _1L and F _2L transmitted to the connecting portions 115 and 116 is transmitted to the + Z side via the head bolt hole forming portions 137 and 138 and their peripheral portions. Is done.

On the other hand, the remaining loads of the loads F _1U and F _2U and the loads F _1L and F _2L transmitted to the connecting portions 115 and 116 are transmitted through the oblique ribs 140 and 141. The load transmitted through the oblique ribs 140 and 141 is dispersed in the region between the head bolt hole forming portion 137 and the head bolt hole forming portion 138 (part of the side wall surface of the inner cylinder forming portion 112). _Is transmitted toward + Z side (load F _com ).

Note that the loads transmitted load and oblique ribs 141 transmitted the oblique ribs 140 is temporarily assembled in intersection P _1. Therefore, between each of the connecting portions 115 and 116 to the intersection P _1, even if there is variation between the loads transmitted load and oblique ribs 141 transmitted the oblique ribs 140, as described above load also force by a set once at the intersection P _1, the leveling of the force is made.

Therefore, in the region between the head bolt hole forming portion 137 and the head bolt hole forming portion 138 on the side wall surface of the inner cylinder forming portion 112, the load F _com transmitted toward the + Z side varies in the X direction. Suppressed and equalized.

In the block core 11 according to the present embodiment, since is positioned by -Z side distance H ₁ the intersection P ₁ from the mating surface mating surface 11c, to the mating surface 11c of intersection P ₁ in the Z-direction The load is further distributed in the region between them, and the local application of the load on the mating surface 11c is suppressed.

Further, part of the load transmitted through the oblique ribs 140 and 141 is transmitted to the head bolt hole forming portions 137 and 138 via the connection points P ₂ and P ₃ . Also in this case, since the connection places P ₂ and P ₃ are positioned on the −Z side by the distance H ₂ from the mating surface 11c, it is possible to suppress a local load from acting on the mating surface 11c as described above. .

  Furthermore, the oblique ribs 140 and 141 provided on the side wall surfaces of the inner cylinder forming portions 112 and 113 of the block core 11 according to the present embodiment are provided with compressive stress (cylinder head 13 and bearing cap 15 between the cylinder head 13 and the bearing cap 15). (Compressive stress acting on the block core 11 sandwiched between them) is also effective from the viewpoint of ensuring the sealing performance between the cylinder head 13 and the block core 11 at the mating surface 11c.

  That is, the portion (head bolt hole) through which the head bolt 20 is inserted into the block core 11 sandwiched between the cylinder head 13 and the bearing cap 15 by screwing between the head bolt 20 and the screw hole 15a of the bearing cap 15. High compressive stress is likely to act on the peripheral portions 127 to 136), but the inclined ribs 140 and 141 provided on the side wall surfaces of the inner cylinder forming portions 112 and 113 can distribute the compressive stress, and the cylinder head 13 And a high sealing property between the block core 11 can be ensured.

7). Configuration of End Shaft Supports 118 and 122 and Bearing Caps 151 and 155 The configuration of the end shaft support 118 and 122 and bearing caps 151 and 155 will be described with reference to FIG. FIG. 9 is a schematic perspective view showing configurations of the end shaft support portion 118 and the bearing cap 151. In FIG. 9, the end shaft support portion 122 and the bearing cap 155 are not shown, but have the same configuration as the end shaft support portion 118 and the bearing cap 151.

  As shown in FIG. 9, the end shaft support portion 118 is provided with vertical ribs (corresponding to second ribs) 146 and 147 protruding from both side portions in the Y direction to the + Y side and the −Y side. The vertical ribs 146 and 147 have a thin plate shape or a fin shape.

  The bearing cap 151 is provided with vertical ribs 156 and 157 protruding from both sides in the Y direction to the + Y side and the −Y side. The vertical ribs 156 and 157 are in contact with the vertical ribs 146 and 147 on the + Z side, and have a thin plate shape or a fin shape like the vertical ribs 146 and 147.

  Head bolt hole forming portions 144 and 145 are provided on the end wall surface 111 a on the −X side of the cylinder forming portion (end cylinder forming portion) 111. The head bolt hole forming portion 144 is provided at the end on the + Y side, and the head bolt hole forming portion 145 is provided at the end on the −Y side.

The head bolt hole forming portions 144 and 145 have a semi-cylindrical rib shape protruding from the bolt hole central axes Ax ₁₂₇ and Ax ₁₂₈ of the head bolt holes ₁₂₇ and ₁₂₈ to the −X side. The head bolt hole 127 is provided in the head bolt hole forming part 144, and the head bolt hole 128 is provided in the head bolt hole forming part 145.

  The end wall surface on the −X side of the shaft support portion 118 includes an end wall reinforcing rib 148 extending from the outer edge portion of the bearing portion 11b to the + Y side and extending obliquely to the + Z side, and the −Y side from the outer edge portion of the bearing portion 11b. An end wall reinforcing rib 149 extending obliquely on the + Z side is provided.

  The end wall reinforcing ribs 148 and 149 have a semi-cylindrical rib-like configuration protruding to the −X side. The end wall reinforcing rib 148 has an end on the + Z side connected to the head bolt hole forming portion 144, and the end wall reinforcing rib 149 has an end on the + Z side connected to the head bolt hole forming portion 145. Yes.

  The end wall surface on the −X side of the bearing cap 151 includes an end wall reinforcing rib 158 that extends from the outer edge portion of the bearing portion 15 b to the + Y side and obliquely extends to the −Z side, and the outer edge portion of the bearing portion 15 b to the −Y side. An end wall reinforcing rib 159 extending obliquely on the −Z side is provided.

  The end wall reinforcing ribs 158 and 159 have a semi-cylindrical rib-like configuration protruding to the −X side. The end wall reinforcing rib 158 and the end wall reinforcing rib 159 are provided in a state where the cavity 151a is sandwiched between each other in the Y direction.

8). The role played by the longitudinal ribs 156 and 157 with respect to the bending load caused by the rotation of the crankshaft 16 will be described with reference to FIG. FIG. 10 is a schematic diagram for explaining the role played by the longitudinal ribs 156 and 157 when a bending load is applied to the shaft support portion 118. In FIG. 10, only the vertical ribs 157 of the vertical ribs 156 and 157 are illustrated and the vertical ribs 156 are not illustrated, but the vertical ribs 156 are the same as the vertical ribs 157 described below. To play a role.

As shown in FIG. 10, a bending load F _BE as shown by an arrow acts on the shaft support portion 118 located at the end portion in the X direction of the block core 11 as the crankshaft 16 rotates.

As described above, since the shaft support portion 118 is provided with the longitudinal ribs 156 and 157, the bending rigidity with respect to the bending load F _BE is improved. That is, the shaft support portion 118 provided with the vertical ribs 156 and 157 is reinforced in terms of rigidity with respect to the bending load F _BE compared to the case where the vertical rib is not provided.

As described above, in the engine 1 according to this embodiment, since the lower end portion 151b of the bearing cap 151 is a free end, the shaft support portion 118 is easily deformed by the bending load F _BE , and such deformation The role played by the vertical ribs 156 and 157 is particularly important from the viewpoint of preventing the above.

Further, end wall reinforcing ribs 148 and 149 (the illustration of the end wall reinforcing ribs 149 is omitted in FIG. 10) are provided on the end wall surface of the shaft support portion 118, and this also _applies to the bending load F _BE . Reinforcement on the rigid surface is achieved.

  Further, with respect to the end wall reinforcing ribs 148 and 149, the compression stress acting on the block core 11 by tightening the head bolt 20, that is, the tightening of the head bolt 20 causes the block core 11 to move between the cylinder head 13 and the bearing cap 151. Even with respect to the compressive stress received at, the stress is dispersed by the end wall reinforcing ribs 148 and 149 provided on the end wall surface of the shaft support portion 118. Therefore, the sealing performance between the cylinder head 13 and the block core 11 can be ensured.

9. Effect In the engine 1 according to the present embodiment, the connection portions 115 to 117 provided on both sides in the X direction are provided on the side wall surfaces (the + Y side wall surface and the −Y side wall surface) of the inner cylinder forming portions 112 and 113, respectively. Two oblique ribs 140 and 141 are provided as base ends. Then, the two diagonal ribs 140 and 141 intersect at intersection _{P 1} together. For this reason, in the engine 1 according to the present embodiment, when the crankshaft 16 supported by the shaft support portions 118 to 122 and the bearing cap 15 rotates, it is transmitted to the shaft support portions 119 to 121 in the Z direction. Loads F _1U , F _2U , F _1L and F _2L are transmitted from the connecting portions 115 to 117 to the oblique ribs 140 and 141, and are distributed in the circumferential direction of the inner cylinder forming portions 112 and 113 (the X direction in FIG. 8). Will be. Therefore, in the engine 1 according to the present embodiment, a high seal between the cylinder head 13 and the block core 11 is obtained by dispersing the loads F _1U , F _2U , F _1L and F _2L accompanying the rotation of the crankshaft 16. Sex can be secured.

In the engine 1 according to the present embodiment, the loads F _1U , F _2U , F _1L , and F _2L can be dispersed by forming the oblique ribs 140 and 141 on the side wall surfaces of the inner cylinder forming portions 112 and 113. In order to cope with the loads F _1U , F _2U , F _1L , and F _2L , it is not necessary to increase the thickness of the inner cylinder forming portions 112 and 113 as a whole, and an increase in weight can be suppressed.

Further, in the engine 1 according to the present embodiment, the intersection P ₁ of the oblique ribs 140 and diagonal ribs 141 intersect, as shown in FIG. 8, since the set on a bore central axis Ax _112, oblique The load (load F _com ) distributed by the ribs 140 and 141 is evenly distributed in the circumferential direction of the inner cylinder forming portions 112 and 113.

Further, in the engine 1 according to this embodiment, as described referring to FIG. 6, since the position of the distance H ₁ by -Z side (lower side) of the mating surface 11c of intersection P _1, the mating surface 11c Thus, the load concentration in the circumferential direction of the cylinders 124 and 125 can be suppressed. That is, if the upper end portion of the oblique rib is located on the mating surface 11c, stress concentrates on the upper end portion of the oblique rib, and as a result, the surface of the mating surface 11c in the circumferential direction of the cylinders 124 and 125. This causes non-uniform pressure and leads to a decrease in sealing performance.

On the other hand, in the engine 1 according to this embodiment, as shown in FIG. 6, since the position of only the -Z side (lower side) distance H ₁ from the mating surface 11c of intersection P _1, mating surface 11c in the Z-direction since the dispersion of the load is achieved between the intersection P ₁ and, it is possible to suppress the nonuniformity of the surface pressure in the circumferential direction of the cylinder 124, 125 in the mating surface 11c occurs, the high sealing property Can be secured.

  Further, in the engine 1 according to the present embodiment, since the crankshaft 16 is supported by attaching the bearing caps 151 to 155 to the shaft support portions 118 to 122, the cylinder block 10 is assembled when the engine 1 is assembled. In contrast, the crankshaft 16 can be easily assembled.

  In the engine 1 according to this embodiment, the block core 11 of the cylinder block 10 is sandwiched between the cylinder head 13 and the bearing cap 15 by screwing the head bolt 20 and the screw hole 15a of the bearing cap 15. It is in a state. In such a state, a high compressive stress is likely to act on a portion through which the head bolt 20 is inserted (peripheral portions of the head bolt holes 127 to 136). However, in the engine 1 according to the present embodiment, the inner cylinder forming portions 112 and 113. Since the slanted ribs 140 and 141 are provided on the side wall surface, the compressive stress is dispersed and stress concentration is avoided. Therefore, in the engine 1 according to the present embodiment, an increase in weight can be suppressed while ensuring high sealing performance.

Further, in the engine 1 according to the present embodiment, the lower ends 152a and 153a of the bearing caps 151 to 155 are free ends, and loads in the Z direction F _1U , F _2U , F _1L , F _2L is transmitted to the connecting portions 115 to 117. Even in this case, in the engine 1 according to the present embodiment, by providing the oblique ribs 140 and 141 intersecting each other on the side wall surfaces of the inner cylinder forming portions 112 and 113, the load can be distributed, and the cylinder head 13 can be dispersed. And high sealing performance between the block core 11 can be ensured.

Further, in the engine 1 according to the present embodiment, since the longitudinal ribs 156 and 157 extending in the Z direction are formed on the side wall surfaces of the end shaft support portions 118 and 122, the shaft support portion 118 accompanying the rotation of the crankshaft 16. , 119, even when a bending stress F _BE is used as a fulcrum, deformation of the shaft support portions 118, 122 in the bending direction (elastic deformation and plastic deformation) is caused by the formation of the longitudinal ribs 156, 157. It is suppressed.

  In addition, since the engine 1 according to the present embodiment includes the cylinder block outer wall 12 formed using a resin material, the weight of the engine 1 can be reduced compared to the case where the entire cylinder block 10 is formed using a metal material. Can do. Further, the cylinder head 13 is formed by forming the oblique ribs 140 and 141 on the side wall surfaces of the inner cylinder forming portions 112 and 113 as described above while reducing the weight using the cylinder block outer wall 12 made of the resin material. And high sealing performance between the block core 11 can be ensured.

  As described above, in the engine 1 according to the present embodiment, the load accompanying the rotation of the crankshaft 16 during driving is prevented from acting locally on the mating surface 11c in the cylinder block 11, and the cylinder head 13 It is possible to ensure high sealing performance with the cylinder block 10 and to suppress increase in weight.

[Modification]
In the engine 1 according to the above-described embodiment, the two oblique ribs 140 and 141 are provided on the side wall surfaces of the inner cylinder forming portions 112 and 113 of the block core 11, but the present invention is not limited thereto. Absent. For example, three or more oblique ribs may be provided, and at least two oblique ribs may intersect.

  In the engine 1 according to the above-described embodiment, each of the oblique ribs 140 and 141 employs a rib having a shape that extends straight in a side view from the Y direction, but the present invention is not limited thereto. For example, a rib extending so as to be curved in a side view can be employed.

  In addition, oblique ribs may be provided on the side wall surfaces of the cylinder forming portions 111 and 114.

  In the engine 1 according to the above embodiment, the form in which the + Z side ends of the oblique ribs 140 and 141 are connected to the head bolt hole forming portions 137 and 138 is adopted, but the present invention is not limited to this. . For example, a configuration in which a gap exists between the end portion of the oblique rib and the head bolt hole forming portion can be employed.

  In the engine 1 according to the above embodiment, the lower end portions of the bearing caps 151 to 155 are not connected to each other, and the respective lower end portions are in a free end state, but the present invention is limited to this. It is not something to receive. For example, it is good also as connecting the lower end parts of a bearing cap mutually with a beam-shaped member.

  In the above embodiment, the head bolt 20 is inserted through the cylinder head 13 and the block core 11 and screwed into the screw hole 20b provided in the bearing cap 15. However, the present invention is not limited to this. It is not something to receive. For example, the head bolt may be inserted through a cylinder head, a block core, and a bearing cap and screwed to a nut disposed below the bearing cap. In addition, a screw hole is provided in the block core, and the bolt through which the cylinder head is inserted is screwed into the screw hole of the block core. On the other hand, the bolt through which the bearing cap is inserted is inserted from below the bearing cap. It is good also as making it screw in a screw hole.

  In the engine 1 according to the above-described embodiment, no particular mention has been made as to whether or not the head gasket is interposed between the cylinder head 13 and the cylinder block 10, but it may be inserted.

  In the above embodiment, a 4-cylinder gasoline engine is used as the engine 1 as an example, but the present invention is not limited to this. For example, an engine having 3 cylinders or 5 cylinders or more can be employed, and a diesel engine can also be employed.

DESCRIPTION OF SYMBOLS 1 Engine 10 Cylinder block 11 Block core 11a, 13a, 127-136 Head bolt hole 12 Cylinder block outer wall 13 Cylinder head 15, 151-155 Bearing cap (cap part)
15a Screw hole 20 Head bolt 111-114 Cylinder formation part 115-117 Connection part 118-122 Shaft support part (engine output shaft support part)
123-126 Cylinder 140, 141 Diagonal rib (first rib)
146, 147 Vertical rib (second rib)
156,157 Vertical rib

Claims (8)

In multi-cylinder engines,
An engine output shaft of the multi-cylinder engine;
Three or more cylinder forming portions each extending in a direction orthogonal to the engine output shaft, each forming a cylinder, and continuously formed with each other;
In the engine output shaft direction, a connecting portion that connects the cylinder forming portions adjacent to each other , and a plurality of connecting portions disposed below the cylinder forming portion in the cylinder axial direction;
For each of said plurality of connecting portions, with and extends toward the lower side side in the cylinder axis direction, and a plurality of engine output shaft supporting portion having a portion for supporting the engine output shaft ,
The side wall surface of at least one of the three or more cylinder forming portions is in the cylinder axial direction with the connecting portions on both sides of the cylinder forming portion in the engine output shaft direction as base ends, respectively. Two first ribs extending obliquely upward and intersecting each other,
Multi-cylinder engine. The multi-cylinder engine according to claim 1,
When the side wall surface of the cylinder forming portion having the first rib is viewed from the side perpendicular to both the cylinder axis direction and the engine output axis direction, the location where the two first ribs intersect is Located on the central axis of the cylinder of the cylinder forming portion,
Multi-cylinder engine. The multi-cylinder engine according to claim 1 or 2,
A cylinder head mounted on the three or more cylinder forming portions in the cylinder axial direction;
The location where the two first ribs intersect is a location below the mating surface with the cylinder head in the cylinder forming portion.
Multi-cylinder engine. The multi-cylinder engine according to claim 3,
A cap portion connected to each of the plurality of engine output shaft support portions below the cylinder axis direction is further provided,
The engine output support portion and the cap portion are connected to sandwich the engine output shaft at a portion corresponding to the diameter center of the engine output shaft in the cylinder axis direction,
The three or more cylinder forming portions, the plurality of connection portions, and the plurality of engine output support portions constitute a cylinder block.
Multi-cylinder engine. The multi-cylinder engine according to claim 4,
A plurality of head bolts for attaching the cylinder head to the cylinder block;
The cylinder block penetrates from the mating surface to the lower end in the cylinder axis direction at each of the portions where the adjacent cylinder forming portions are connected in the engine output axis direction, and the head bolt is inserted through the first cylinder block. Has a head bolt hole,
Each of the cylinder heads has a plurality of second head bolt holes through which the head bolts are inserted, each of which is continuous with the plurality of first head bolt holes.
Each of the plurality of cap portions is continuous with the first head bolt hole and has a screw hole screwed to the head bolt.
Each of the plurality of head bolts is inserted through the first head bolt hole and the second head bolt hole, and is screwed to a female screw of the screw hole. By the screwing, the cylinder block is In a state of being tightly sandwiched between the cylinder head and the cap portion,
Multi-cylinder engine. The multi-cylinder engine according to claim 4 or 5,
The plurality of cap portions are not connected to each other at the lower end portions thereof in the cylinder axial direction, and each of the lower end portions is in a free end state.
Multi-cylinder engine. In multi-cylinder engines,
An engine output shaft of the multi-cylinder engine;
Three or more cylinder forming portions each extending in a direction orthogonal to the engine output shaft, each forming a cylinder, and continuously formed with each other;
A plurality of connecting portions disposed at a lower portion in the cylinder axial direction in a portion where the adjacent cylinder forming portions are connected in the engine output shaft direction;
A plurality of engine output shaft support portions that extend toward the lower side in the cylinder axis direction with respect to each of the plurality of connection portions, and have a portion that supports the engine output shaft;
With
The side wall surface of at least one of the three or more cylinder forming portions is in the cylinder axial direction with the connecting portions on both sides of the cylinder forming portion in the engine output shaft direction as base ends, respectively. Two first ribs extending diagonally upward and intersecting each other,
The cylinder forming portion having the first rib is an inner cylinder forming portion excluding end cylinder forming portions at both ends in the engine output shaft direction among the three or more cylinder forming portions,
The engine further includes two end engine output shaft support portions that extend from the outer portions of the end cylinder forming portion toward the lower side in the cylinder axis direction and have a portion that supports the engine output shaft. ,
Each side wall surface of the two end engine output shaft support portions has a second rib extending in the cylinder axis direction.
Multi-cylinder engine. A multi-cylinder engine according to any one of claims 1 to 7,
A cylinder block outer wall that is formed using a resin material and surrounds the three or more cylinder forming portions, the plurality of connection portions, and the plurality of engine output shaft support portions from the outside;
Multi-cylinder engine.

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