JP2005201084A - Cylinder block - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder block being easy to form a water jacket at the surroundings of a cylinder and suppress transmission of vibration of a cylinder liner to the outer wall part of a cylinder. <P>SOLUTION: A water-cooled engine is constituted such that the middle stage part of a cylinder block 3 where a water jacket is formed at the periphery of a cylinder is divided into a cylinder line part 20 of which the wall surface on the cylinder side is formed, and a cylinder outer wall part 32 of which an outer wall surrounds a portion of which the water jacket consists, in a manner that a portion consists of the water jacket forms a boundary, and when a cylinder coupling body 21 is assembled to the cylinder outer wall part 32, a damping rubber 43 is supported between a protrusion part 41 on the liner part side situated the side above a cylinder coupling body 21 and a surface opposed thereto. The damping rubber 43 is disposed in a position (on the side situated above the water jacket) corresponding to a side when a piston 40 is positioned at a top dead center. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cylinder block used in an engine formed by assembling a cylinder block having a water jacket defined around a cylinder to a cylinder head.

  The engine cylinder block is formed with a water jacket that circulates cooling water around the cylinder. The cylinder block includes a cylinder portion in which a cylinder bore is formed at an upper portion thereof, and a crankcase portion constituting a crankcase at a lower portion thereof. Incidentally, the water jacket structure in the cylinder block of such an engine includes an open deck structure in which the water jacket is opened on the top surface of the cylinder block and a closed deck structure in which the water jacket is closed without being opened on the top surface of the cylinder block. is there.

For example, Patent Document 1 discloses a liner having a separate structure from a cylinder block. When such a separate structure is adopted, it is necessary to appropriately support the liner with respect to the cylinder block. Therefore, in the above-described document, the liner is elastically supported by an elastic mount member disposed at the lower portion of the liner.
JP-A-5-5457

  According to such a conventional configuration, for example, a certain degree of suppression effect can be expected with respect to the vibration of the liner accompanying the vertical movement of the piston, that is, the vibration in the cylinder axis direction. However, since this elastic mounting member also has the sealing function of the water jacket, it must be disposed at the lowest position. For this reason, the elastic mount member cannot effectively suppress vibration in the cylinder radial direction, and still leaves room for improvement in this respect.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a cylinder block that can suitably suppress the vibration of the cylinder liner portion and thus the vibration from being transmitted to the cylinder block body.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
The invention according to claim 1 is a cylinder block that forms a main body of an engine by forming a water jacket around the cylinder and assembling the cylinder head, and the cylinder block serves as the water jacket. It consists of a separate structure of the cylinder liner part that constitutes the cylinder side and the cylinder block body that constitutes the outer wall of the water jacket, with the part as a boundary, and between the cylinder liner part and the cylinder block body. The gist is that an elastic member is supported at a position where the water jacket is partitioned vertically.

  According to the above configuration, the vibration of the cylinder liner portion is caused by the damping action of the elastic member interposed at the position where the water jacket is partitioned vertically, that is, at the position where the amplitude of vibration is larger than the end portion of the water jacket. It can suppress suitably that the vibration is transmitted to a cylinder block main body.

  By the way, the vibration of the cylinder liner portion is caused by the fact that the piston of the engine is in the vicinity of the top dead center and the piston swings strongly due to the action of the combustion pressure, so-called piston swinging phenomenon occurs. large. Accordingly, the gist of the invention according to claim 2 is that, in the cylinder block according to claim 1, the elastic member is arranged above the cylinder liner portion.

  According to a third aspect of the present invention, in the cylinder block according to the first aspect, the elastic member corresponds to a side surface of the piston when the piston reciprocating inside the cylinder liner portion is located at a top dead center. The gist is that it is disposed at a position to be operated.

  According to the configuration described in each of these claims, even if such a piston swing phenomenon occurs, the vibration of the cylinder liner portion caused by such a swing phenomenon, and further, this is transmitted to the cylinder block body. Vibration can be suitably suppressed.

  In addition, the piston swinging phenomenon has the largest vibration component in the direction orthogonal to the cylinder arrangement direction. Therefore, according to a fourth aspect of the present invention, in the cylinder block according to any one of the first to third aspects, at least a part of the elastic member is disposed on a line orthogonal to the arrangement direction of the cylinders. This is the gist. According to this configuration, it is possible to more effectively suppress the vibration generated due to the swinging phenomenon of the piston.

  The gist of the invention described in claim 5 is that the elastic member is supported between a projecting portion extending from at least one of the cylinder liner portion and the cylinder block body into the water jacket and the other.

  According to the above configuration, even if the size and shape of the elastic member interposed between the gaps forming the water jacket are limited, this can be appropriately adjusted by the protrusion. Furthermore, by appropriately setting the damping action by the elastic member and the rigidity by the protrusion, the natural frequency of the vibration system including the elastic member and the protrusion is adjusted, and the vibration generated in the cylinder liner portion is more effective. It is also possible to suppress it.

  According to a sixth aspect of the present invention, in the cylinder block according to any one of the first to fifth aspects, the support surface that supports the elastic member of the protrusion is an inner periphery of the cylinder block main body toward the upper side. It is assumed that it is formed in an oblique shape so as to be close to the surface.

  According to the above configuration, the elastic member is gradually pressed by the protrusion when the cylinder liner portion is inserted into the cylinder block main body from above, so that the position of the elastic member is prevented from shifting to the upper side of the cylinder. Will be able to.

The gist of a seventh aspect of the present invention is that, in the cylinder block according to any one of the first to sixth aspects, the protrusion has an annular shape surrounding the cylinder.
According to the said structure, this can be easily formed compared with the case where a protrusion is selectively formed around a cylinder, for example.

According to an eighth aspect of the present invention, in the cylinder block according to the seventh aspect, the elastic member has an annular shape that is supported over the entire circumference by the annular projecting portion.
According to the above configuration, even if the vibration generated in the cylinder liner portion has various modes, such vibration can be effectively suppressed by the elastic member provided over the entire circumference of the cylinder liner portion. become able to.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment embodying a cylinder block according to the present invention will be described in detail based on the drawings.
FIG. 1 shows a perspective structure of a main body 1 of an in-line four-cylinder water-cooled engine employing the cylinder block of this embodiment. The main body 1 of the water-cooled engine is roughly configured to include a cylinder head 2 and a cylinder block 3. The cylinder head 2 and the cylinder block 3 are assembled by bolt fastening via a gasket 4. A head cover is attached above the cylinder head 2, and an oil pan is attached below the cylinder block 3.

  2A shows a perspective structure of the cylinder block 3, and FIG. 2B shows a side structure thereof. As shown in these drawings, the cylinder block 3 is formed with four cylinders 5 at the upper portion thereof, and a crankcase portion 31, that is, a so-called cylinder block skirt portion is provided at the lower portion thereof. The crankcase portion 31 forms a crankcase in which the crankshaft is housed together with the oil pan attached below the crankcase portion 31. Further, on the top of the cylinder block 3, there is provided a flat upper deck portion 22 on which the cylinder head 2 is placed and abutted against the bottom surface thereof.

  FIG. 3 shows an exploded perspective view of the cylinder block 3. As shown in the figure, the cylinder block 3 constitutes a cylinder liner portion 20 constituting the cylinder side and an outer wall of the water jacket, with a portion serving as a water jacket formed around the cylinder 5 as a boundary. A separate structure from the cylinder block body 30 is provided. The cylinder liner portion 20 is integrally formed with a cylinder coupling body 21 in which the cylinders 5 are integrally coupled, and the upper deck portion 22 provided at the upper end thereof. The cylinder block body 30 is integrally formed with a cylinder outer wall portion 32 surrounding the outer periphery of the cylinder coupling body 21 and the crankcase portion 31.

  The cylinder liner part 20 which comprises the cylinder coupling body 21 and the upper deck part 22 consists of an aluminum alloy or a magnesium alloy, for example, and is integrally cast using the die-casting manufacturing method. The cylinder block body 30 constituting the crankcase portion 31 and the cylinder outer wall portion 32 is made of an aluminum alloy, a magnesium alloy, or the like, like the cylinder liner portion 20, and is integrally cast using a die casting method or the like. A plurality of ribs 3a for reinforcement are formed on the outer circumferences of the crankcase portion 31 and the cylinder outer wall portion 32 of the cylinder block body 30 so as to extend vertically and horizontally.

  4A shows a perspective structure of the cylinder liner portion 20, and FIG. 4B shows a side structure thereof. As shown in these drawings, the cylinder coupling body 21 of the cylinder liner portion 20 is formed in a shape in which four cylindrical bodies serving as cylinder liners of the respective cylinders are continuously connected in series. The outer peripheral surface of this cylinder coupling body 21 constitutes the wall surface on the cylinder side of the water jacket.

  The upper deck portion 22 has a flat plate shape, and is formed in a flange shape at the upper end portion of the cylinder coupling body 21. The upper deck portion 22 constitutes the top surface portion of the cylinder block 3. The upper surface of the upper deck portion 22 is a mounting surface 26 on which the cylinder head 2 is mounted. When the cylinder head 2 and the cylinder block 3 are assembled, the bottom surface of the cylinder head 2 is mounted via the gasket 4. Placed. Further, the upper deck portion 22 is formed with a plurality of bolt insertion holes 27 through which head bolts used for fastening the cylinder head 2 and the cylinder block 3 are inserted. Further, the upper deck portion 22 has a plurality of through holes such as a cooling water hole 28, an oil hole 29a, and a blow-by gas hole 29b.

  A plurality of (three in this embodiment) liner portion side protrusions 41 are formed on the upper side of the outer peripheral surface 24 of the cylinder coupling body 21. These liner side protrusions 41 protrude in a direction perpendicular to the axis of the cylindrical body, that is, the cylinder 5. The liner-side protrusion 41 is formed in an annular shape over the outer periphery of the cylinder coupling body 21 so as to surround the cylinder 5. Moreover, the said liner part side protrusion 41 is provided in the up-down direction (axial direction of the cylinder 5) at predetermined intervals. These liner part side protrusions 41 are formed on the upper side of each cylinder 5, in other words, at a position corresponding to the side surface when the piston 40 is located at its top dead center (see FIG. 6).

  Moreover, the front-end | tip part of each liner part side protrusion 41 is formed in the slant shape so that it may reduce in diameter as it goes to the downward side from the upper side. Furthermore, the front end surface of each liner part side protrusion 41 is a support surface 41a that supports a vibration-proof rubber described later. As a result, the support surface 41a comes closer to the inner peripheral surface 35 of the cylinder outer wall portion 32 toward the upper side (see FIG. 6). The rigidity of the cylinder liner portion 20 is increased by the liner portion side protrusions 41.

On the other hand, a taper portion 25 whose diameter decreases as it goes downward in the axial direction of the cylinder 5 is provided at the lower portion of the outer peripheral surface 24 of the cylinder coupling body 21.
5A shows a perspective structure of the cylinder block body 30, and FIG. 5B shows a side structure thereof. As shown in these drawings, a cylinder outer wall portion 32 is formed at the upper portion of the crankcase portion 31. The cylinder outer wall portion 32 has a substantially annular inner peripheral surface 35 formed so as to face the outer peripheral surface 24 of the cylinder coupling body 21 of the cylinder liner portion 20. The inner peripheral surface 35 of the cylinder outer wall portion 32 constitutes an outer wall of a water jacket formed around the cylinder.

  A plurality of bolt fastening holes 37 for fastening the head bolts are formed in the cylinder outer wall portion 32 from the upper receiving surface 32a. Further, an oil passage 38a for returning excess oil from the cylinder head 2 to the oil pan and a blow-by gas passage 38b extending from the crankcase into the cylinder head 2 and allowing blow-by gas to pass therethrough are provided in the cylinder outer wall portion 32. The passages are formed in the receiving surface 32a. In addition, a cooling water port 39 used for inflow or outflow of cooling water with respect to the water jacket is formed on the side of the cylinder outer wall portion 32.

  The cylinder coupling body 21 of the cylinder liner portion 20 is inserted and mounted in the cylinder outer wall portion 32 from above. In this state, a gap is formed between the opposing surfaces of the outer peripheral surface 24 of the cylinder coupling body 21 and the inner peripheral surface 35 of the cylinder outer wall portion 32. And the cooling water hole 28 formed in the upper deck part 22 is opened by the part of such a gap | interval in the upper deck part 22 lower surface side. Further, each bolt fastening hole 37 of the cylinder outer wall portion 32 and each opening of the oil passage 38a and blow-by gas passage 38b are respectively connected to each bolt insertion hole 27, oil hole 29a and blow-by gas hole 29b formed in the upper deck portion 22. Each is located at the same position.

  FIG. 6 shows a cross-sectional structure of the cylinder block 3 along the line VI-VI in FIG. 2B in a state where the cylinder liner portion 20 is mounted on the cylinder block body 30. As shown in the figure, at the lower end of the inner peripheral surface 35 of the cylinder outer wall portion 32, a support portion 42 that protrudes toward the outer peripheral surface 24 of the cylinder coupling body 21 of the cylinder liner portion 20 extends along the inner peripheral surface 35. Around. The inner surface of the support portion 42, that is, the front end surface thereof, abuts the outer peripheral surface 24 (tapered surface 25) of the cylinder coupling body 21 of the cylinder liner portion 20 from the outer peripheral side below the portion serving as the water jacket. The lower receiving surface 42a to support is comprised.

  A step 35a is provided at substantially the center in the vertical direction of the inner peripheral surface 35 of the cylinder outer wall portion 32, and a portion below the step 35a of the inner peripheral surface 35 is compared with a portion above the cylinder connecting body. It is formed so as to be close to the outer peripheral surface 24 of 21.

  A flange 36 is formed at the upper end of the cylinder outer wall 32 so as to protrude from the outer periphery to the cylinder outer periphery. The flange 36 is connected to the rib 3a formed on the outer periphery of the cylinder outer wall 32, and the rigidity thereof is enhanced (see FIG. 5A). The top surface of the cylinder outer wall portion 32 where the flange 36 is formed is an upper receiving surface 32 a that abuts and supports the upper deck portion 22 of the cylinder liner portion 20. In this embodiment, the area of the receiving surface is increased by forming the flange 36 at the upper end of the cylinder outer wall 32.

  As shown in the figure, the cylinder coupling body 21 of the cylinder liner portion 20 is inserted into the cylinder outer wall portion 32 up to a position where the upper receiving surface 32a of the cylinder outer wall portion 32 and the lower surface of the upper deck portion 22 come into contact with each other. Yes. Thus, the water jacket 6 is defined around the cylinder 5 by the outer peripheral surface 24 of the cylinder coupling body 21, the inner peripheral surface 35 of the cylinder outer wall portion 32, and the lower surface of the upper deck portion 22. . And the lower part of the water jacket 6 is obstruct | occluded by the said support part 42. FIG.

  In a state where the cylinder coupling body 21 is assembled to the cylinder outer wall portion 32, an elastic member is provided between the support surface 41a of each liner portion side protrusion 41 and the opposing surface (the inner peripheral surface 35 of the cylinder outer wall portion 32). The anti-vibration rubber 43 is supported by interposition or adhesion. These anti-vibration rubbers 43 are made of, for example, silicone resin, and are disposed on the upper side of the water jacket 6 so as to partition the water jacket 6 vertically. These anti-vibration rubbers 43 are disposed at positions corresponding to the side surfaces when the piston 40 is located at its top dead center. The anti-vibration rubber 43 is provided in an annular shape so as to surround each cylinder 5. These anti-vibration rubbers 43 are supported over the entire circumference by the support surface 41a of the corresponding liner-side protrusion 41. Each anti-vibration rubber 43 is supported in a compressed state by being sandwiched between the support surface 41a of the liner side protrusion 41 and its opposing surface during the assembly.

  On the other hand, a seal ring 44 is interposed between the contact surface between the lower receiving surface 42 a of the support portion 42 and the outer peripheral surface 24 of the cylinder coupling body 21 below the water jacket 6. The seal ring 44 is supported in a compressed state by being sandwiched between the lower receiving surface 42a and the outer peripheral surface 24 during the assembly. The seal ring 44 seals between the contact surfaces that close the lower portion of the water jacket 6.

  FIG. 7 shows a cross-sectional structure of a main part of the water-cooled engine along the line VII-VII in FIG. 1 in a state where the cylinder block 3 is assembled to the cylinder head 2. As shown in the figure, the cylinder block 3 is assembled to the cylinder head 2 through fastening of head bolts 7.

  Here, the head bolt 7 is inserted into a bolt fastening hole 37 provided in the cylinder block body 30 through a bolt insertion hole 27 formed in the upper deck portion 22 of the cylinder liner portion 20 and is screwed. At this time, the upper deck portion 22 of the cylinder liner portion 20 is sandwiched between the bottom surface 2 a of the cylinder head 2 and the receiving surface 32 a of the cylinder outer wall portion 32 of the cylinder block body 30, and the head bolt 7 is tightened. The bottom surface 2a and the receiving surface 32a receive a compressive force and are fastened and fixed.

  A water jacket, an oil passage, and a blow-by gas passage formed in the cylinder head 2 are opened on the bottom surface 2a of the cylinder head 2. After the assembly, the openings are located at the same positions as the corresponding through holes of the upper deck portion 22, that is, the cooling water hole 28, the oil hole 29a, and the blow-by gas hole 29b. The passages on the cylinder head 2 side and the passages on the cylinder block body 30 side are connected to each other through the through holes.

Next, the operation of the cylinder block 3 will be described below.
First, when the cylinder coupling body 21 is assembled to the cylinder outer wall portion 32, the cylinder coupling body 21 is mounted in a state in which the vibration-proof rubber 43 is attached in advance to the support surface 41a of the liner-side protrusion 41 or slightly below it. Insert into the cylinder outer wall 32. When each anti-vibration rubber 43 is in sliding contact with the inner peripheral surface 35 of the cylinder outer wall portion 32, the anti-vibration rubber 43 is pressed toward the inner peripheral surface 35 of the cylinder outer wall portion 32 by the support surface 41 a of the liner-side protrusion 41. Is done.

  When the vibration isolating rubber 43 is attached in advance to the lower side of the support surface 41a of the liner side projection 41, the vibration isolating rubber 43 is inserted when the cylinder coupling body 21 is further inserted into the cylinder outer wall 32. A part of the cylinder moves to the support surface 41a side as it slides on the inner peripheral surface 35 of the cylinder outer wall 32, and is finally interposed between the support surface 41a and the inner peripheral surface 35 of the cylinder outer wall 32. It becomes a state.

  When the lower surface of the upper deck portion 22 of the cylinder liner portion 20 comes into contact with the upper receiving surface 32a of the cylinder outer wall portion 32, the vibration isolating rubber 43 is positioned with respect to the support surface 41a, and the entire surface of the support surface 41a is vibration proof. The rubber 43 is supported.

  In a normal water-cooled engine, when the piston 40 is located at the top dead center and swings due to the combustion pressure of the air-fuel mixture, that is, when a swinging phenomenon occurs, the cylinder liner 20 vibrates accordingly. Try to occur. However, in the present embodiment, such vibration generated in the cylinder liner portion 20 is attenuated by the vibration isolating rubber 43. Here, in the cylinder block 3 according to the present embodiment, the natural frequency of the vibration system including the anti-vibration rubber 43 and the liner-side protrusion 41 is adjusted, and the main vibration of the vibration caused by such a swinging phenomenon. It is made to substantially coincide with the frequency. For this reason, the vibration which generate | occur | produces in the cylinder liner part 20 can be suppressed more effectively.

  Further, the cylinder liner portion 20 is enhanced in rigidity by forming the liner portion side protrusion 41, thereby further reducing the amplitude of vibration. Further, the vibration of the cylinder liner portion 20 transmitted to the cylinder outer wall portion 32 is naturally suppressed.

The effects obtained by the embodiment described above will be described below.
(1) The cylinder liner portion 20 is held in the cylinder block body 30 in a state in which the vibration isolating rubber 43 is interposed between the support surface 41a of the liner portion side protrusion 41 and the opposing surface. Therefore, the vibration generated in the cylinder liner portion 20 is weakened by the damping action of the anti-vibration rubber 43, so that the vibration is hardly transmitted to the cylinder outer wall portion 32. Therefore, engine noise can be easily and reliably reduced.

  (2) Furthermore, a liner part side protrusion 41 is provided, the natural frequency of the vibration system including the vibration isolating rubber 43 and the liner part side protrusion 41 is adjusted, and the main vibration of the vibration caused by such a swinging phenomenon. It is made to substantially coincide with the frequency. For this reason, the vibration which generate | occur | produces in the cylinder liner part 20 can be suppressed more effectively.

  (3) The anti-vibration rubber 43 is disposed above each cylinder 5 (a position corresponding to a side surface when the piston 40 is located at the top dead center). That is, since the anti-vibration rubber 43 is provided at a position where the vibration amplitude of the cylinder liner portion 20 is increased due to the swinging phenomenon of the piston 40, the vibration generated in the cylinder liner portion 20 is suitably damped. Can do.

  (4) The tip of the liner side protrusion 41 has an oblique shape with a diameter decreasing from the upper side toward the lower side. In the above assembly, the vibration isolating rubber 43 is guided and gradually pressed by the support surface 41a of the liner side protrusion 41. For this reason, there is no possibility that the anti-vibration rubber 43 is displaced upward from the support surface 41a of the liner side projection 41 during the assembly, and the cylinder coupling body 21 can be assembled smoothly.

  (5) The anti-vibration rubber 43 is provided in an annular shape so as to surround the circumference of each cylinder 5, and is supported on the entire circumference by the support surface 41 a of the corresponding liner portion side protrusion 41. Therefore, vibration generated in each part in the circumferential direction of the cylinder liner portion 20 can be attenuated.

  (6) A substantially flat upper deck portion 22 on which the cylinder head 2 is placed is integrally formed at the upper end of the cylinder liner portion 20 so that the upper deck portion 22 is narrowed between the cylinder head 2 and the upper receiving surface 32a. The cylinder liner portion 20 is fixed to the cylinder block body 30 while being held. Further, the cylinder liner portion 20 is also supported by contact with the lower receiving surface 42a from the outer peripheral side below the cylinder liner portion 20. Therefore, the cylinder liner portion 20 can be stably fixed to the cylinder block body 30 against deformation and vibration due to thermal expansion.

  (7) When inserting and assembling the cylinder coupling body 21 into the cylinder outer wall portion 32, the tapered portion 25 serves as an insertion guide for the cylinder coupling body 21. For this reason, the assembly | attachment of the cylinder coupling body 21 and the cylinder outer wall part 32 can be made easy.

In addition, this embodiment can also be changed and embodied as follows.
As shown in FIG. 8, instead of providing the liner portion side protrusion, a configuration in which an outer wall portion side protrusion 101 protrudes above the inner peripheral surface 35 of the cylinder outer wall portion 32 may be employed. The outer wall portion side protrusions 101 are provided in a plurality (three in the figure) in an annular shape along the inner peripheral surface 35 of the cylinder outer wall portion 32. In this case, in order to facilitate insertion and assembly of the cylinder liner portion 20 into the cylinder block main body 30, the diameter of the distal end portion of the outer wall portion side projection 101 is increased from the upper side toward the lower side. It is preferable to form it diagonally. And an elastic member is interposed between the front end surface of this outer wall part side protrusion part 101 and its opposing surface (outer peripheral surface 24 of the cylinder coupling body 21).

  Further, in this case, it is preferable to use a curable liquid gasket (Formed In Place Gasket) as the elastic member. The curable liquid gasket 102 is made of, for example, a silicone resin, and is applied to the distal end surface of the outer wall side protrusion 101 in a liquid state prior to the assembly. The applied curable liquid gasket 102 in a liquid state is sandwiched between the front end surface of the outer wall-side protrusion 101 and its opposite surface (the outer peripheral surface 24 of the cylinder liner portion 20) during the assembly, so that Deforms according to the clearance shape. After that, by setting the necessary conditions by leaving it for a long time or applying heat, the curable liquid gasket 102 in the liquid state is cured and becomes a solid. As a result, a gasket having a shape that matches the clearance shape is self-formed between the abutting surfaces of the front end surface of the outer wall side protrusion 101 and the outer peripheral surface 24 of the cylinder liner portion 20. The curable liquid gasket 102 exhibits the same function and effect as the anti-vibration rubber in the present embodiment.

  Instead of the seal ring 44 used in this embodiment, the curable liquid gasket 102 may be interposed between the lower receiving surface 42a and the outer peripheral surface 24 of the cylinder liner portion 20.

  In the present embodiment, the anti-vibration rubber 43 is provided in an annular shape so as to surround the circumference of each cylinder 5, but it may be provided for each cylindrical body of the cylinder coupling body 21 as shown in FIG. 9. Good. In this case, it is preferable to arrange the vibration isolating rubber 43 on a line extending in the cylinder radial direction orthogonal to the arrangement direction of the cylinders 5. When configured in this way, the vibration isolating rubber 43 is provided at a position where the amplitude of the vibration of the cylinder liner portion 20 based on the swing of the crankshaft becomes large (on a line perpendicular to the arrangement direction of the cylinders 5). It becomes. Thereby, the vibration which generate | occur | produced in the cylinder liner part 20 can be suppressed more effectively. At this time, the liner side protrusion 41 may be provided in an annular shape as in the above embodiment, or may be provided only at a position corresponding to the vibration isolating rubber 43 (on a line orthogonal to the arrangement direction of the cylinders 5).

  The at least one anti-vibration rubber 43 may be provided at a position corresponding to the side surface when the piston 40 is located at the top dead center (above the water jacket 6). In addition to this, the anti-vibration rubber 43 may be provided on the lower side or the center of the water jacket 6.

  When the cylinder coupling body 21 is assembled to the cylinder outer wall portion 32, the cylinder coupling body 21 is inserted into the cylinder outer wall portion 32 with the vibration isolating rubber 43 bonded in advance to the support surface 41 a of the liner side protrusion 41. You may do it. When comprised in this way, the slip of the vibration-proof rubber 43 at the time of the said assembly | attachment can be suppressed.

-The number of anti-vibration rubber 43 is not limited to three, and may be two or less, or four or more.
The tip surface (support surface 41a) of the liner portion side protrusion 41 and the outer wall portion side protrusion 101 in the present embodiment may be a plane parallel to the axis of the cylinder 5.

  As shown by the two-dot chain line in FIG. 6, the liner portion side protrusion 41 may be integrally formed on the lower surface of the upper deck portion 22. At this time, the anti-vibration rubber 43 is supported between the front end surface of the liner portion side protrusion 41 and its opposing surface. In addition, it is preferable that the said liner part side protrusion 41 integrated with the lower surface of the upper deck part 22 is provided in cyclic | annular form along the outer periphery of the cylinder coupling body 21. As shown in FIG.

  In the above embodiment, the upper deck portion 22 is integrally formed with the upper end portion of the cylinder coupling body 21, but the upper deck portion 22 and the cylinder coupling body 21 may be separately provided.

  In place of the vibration isolating rubber 43 and the seal ring 44 in the present embodiment, the curable liquid gasket may be used as an elastic member. That is, prior to the assembly, the curable liquid gasket is applied to the support surface 41a and the lower receiving surface 42a of the liner side protrusion 41. At this time, gaskets having shapes that match the respective clearance shapes are provided between the contact surface between the front end surface of the liner portion side protrusion 41 and the opposing surface, and the contact surface between the lower receiving surface 42a and the opposing surface. Become self-formed in between.

  -You may make it aim at the improvement of the damping property by adding inorganic fillers, such as a talc and a mica, to the raw material (silicone resin) of the vibration-proof rubber in this embodiment. When configured in this way, it is possible to further suppress the occurrence of vibration.

  A configuration in which the anti-vibration rubber 43 and the liner-side protrusion 41 are provided may also be adopted in a type (open deck structure) other than the water-cooled engine having the closed deck structure exemplified in the above embodiment.

  The cylinder block of the present invention can be applied to a water-cooled engine other than the in-line four-cylinder water-cooled engine exemplified in the above embodiment.

The perspective view of the main-body part of a water-cooled engine about one Embodiment of this invention. The figure which shows together (a) perspective structure and (b) side structure of the cylinder block of the embodiment. The exploded perspective view of the cylinder block. The figure which shows together (a) perspective structure and (b) side structure of the cylinder liner part which comprises the cylinder block. The figure which shows together (a) perspective structure and (b) side structure of the cylinder block main body which comprises the cylinder block. Sectional drawing along the VI-VI line of FIG.2 (b). Sectional drawing along the VII-VII line of FIG. The fragmentary sectional view which shows the cross-section of the cylinder block about another embodiment of this invention. The top view which shows the side structure of the cylinder liner part about another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Main part of water-cooled engine, 2 ... Cylinder head, 3 ... Cylinder block, 5 ... Cylinder, 6 ... Water jacket, 20 ... Cylinder liner part, 21 ... Cylinder coupling body, 22 ... Upper deck part, 23 ... Inner peripheral surface 24 ... Outer peripheral surface, 30 ... Cylinder block main body, 32 ... Cylinder outer wall portion, 32a ... Receiving surface, 35 ... Inner peripheral surface, 41 ... Liner side protrusion, 43 ... Anti-vibration rubber as elastic member, 101 ... Outer wall Part side protrusion 102, curable liquid gasket as an elastic member.

Claims (8)

A water jacket is defined around the cylinder and is assembled to the cylinder head to constitute a main body of the engine.
The cylinder block has a separate structure of a cylinder liner part constituting the cylinder side and a cylinder block body constituting the outer wall of the water jacket, with the water jacket as a boundary.
An elastic member is supported between the cylinder liner portion and the cylinder block main body at a position that divides the water jacket vertically. The cylinder block according to claim 1, wherein the elastic member is disposed above the cylinder liner portion. 2. The cylinder block according to claim 1, wherein the elastic member is disposed at a position corresponding to a side surface of the piston when the piston reciprocating inside the cylinder liner portion is located at a top dead center. The cylinder block according to any one of claims 1 to 3, wherein at least a part of the elastic member is disposed on a line orthogonal to the arrangement direction of the cylinders. The cylinder block according to any one of claims 1 to 4, wherein the elastic member is supported between a projecting portion that extends from at least one of the cylinder liner portion and the cylinder block body into the water jacket and the other. The support surface that supports the elastic member of the protrusion is formed in an oblique shape so as to be closer to the inner peripheral surface of the cylinder block body toward the upper side thereof. Cylinder block. The cylinder block according to claim 1, wherein the protrusion has an annular shape surrounding the periphery of the cylinder. The cylinder block according to claim 7, wherein the elastic member has an annular shape that is supported over the entire circumference by the annular projecting portion.

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