Patent Grant
10662873
The present invention relates to a thermal insulator disposed in contact with a wall surface on a groove-like cooling water channel of a cylinder bore wall of a cylinder block of an internal combustion engine, an internal combustion engine including the thermal insulator, and an automobile including the internal combustion engine.
In an internal combustion engine, the structure of which is such that an explosion of fuel occurs at a top dead point of a piston in a bore and the piston is pushed down by the explosion, temperature rises on an upper side of a cylinder bore wall and temperature falls on a lower side of the cylinder bore wall. Therefore, a difference occurs in a thermal deformation amount between the upper side and the lower side of the cylinder bore wall. Expansion is large on the upper side and, on the other hand, expansion is small on the lower side.
As a result, frictional resistance between the piston and the cylinder bore wall increases. This causes a decrease in fuel efficiency. Therefore, there is a need to reduce the difference in the thermal deformation amount between the upper side and the lower side of the cylinder bore wall.
Therefore, conventionally, in order to uniformize a wall temperature of the cylinder bore wall, it has been attempted to set a spacer in the groove-like cooling water channel for adjusting a water flow of cooling water in the groove-like cooling water channel and controlling cooling efficiency on the upper side and cooling efficiency on the lower side of the cylinder bore wall by the cooling water. For example, Patent Literature 1 discloses a heat medium channel partitioning member for internal combustion engine cooling including: a channel partitioning member disposed in a groove-like heat medium channel for cooling formed in a cylinder block of an internal combustion engine to partition the groove-like heat medium channel for cooling into a plurality of channels, the channel partitioning member being formed at height smaller than the depth of the groove-like heat medium channel for cooling and functioning as a wall section that divides the groove-like heat medium channel for cooling into a bore side channel and a counter-bore side channel; and a flexible rip member formed from the channel partitioning member toward an opening section direction of the groove-like heat medium channel for cooling and formed of a flexible material in a form with a distal end edge portion passing over one inner surface of the groove-like heat medium channel for cooling, whereby, after completion of insertion into the groove-like heat medium channel for cooling, the distal end edge portion comes into contact with the inner wall in an intermediate position in a depth direction of the groove-like heat medium channel for cooling with a deflection restoration force of the distal end edge portion to separate the bore side channel and the counter-bore side channel.
[Patent Literature 1]
Japanese Patent Laid-Open No. 2008-31939 (Claims)
With the heat medium channel partitioning member for internal combustion engine cooling of Cited Literature 1, a certain degree of uniformization of the wall temperature of the cylinder bore wall can be achieved. Therefore, it is possible to reduce the difference in the thermal deformation amount between the upper side and the lower side of the cylinder bore wall. However, in recent years, there is a need to further reduce the difference in the thermal deformation amount between the upper side and the lower side of the cylinder bore wall.
Therefore, an object of the present invention is to provide an internal combustion engine with high uniformity of a wall temperature of a cylinder bore wall.
The object is attained by the present invention explained below. Specifically, the present invention (1) is a cylinder bore wall thermal insulator set in a groove-like cooling water channel of a cylinder block of an internal combustion engine including cylinder bores to insulate a bore wall in a one-side half of bore walls of all the cylinder bores,
the thermal insulator including: one or more rubber sections in contact with a wall surface on the cylinder bore side of the groove-like cooling water channel to cover the wall surface on the cylinder bore side of the groove-like cooling water channel; a base section having a shape conforming to a shape of the one-side half of the groove-like cooling water channel, the one or more rubber sections or one or more members to which the one or more rubber sections are fixed being fixed to the base section; and one or more elastic members for urging the entire one or more rubber sections to be pressed from a rear surface side toward the wall surface on the cylinder bore side in a middle and lower part of the groove-like cooling water channel, wherein
the thermal insulator includes a vertical wall on a near side of a boundary of each bore section of the base section in a flowing direction of cooling water.
The present invention (2) provides the cylinder bore wall thermal insulator according to (1), wherein the base section and the vertical wall are made of a metal plate.
The present invention (3) provides the cylinder bore wall thermal insulator according to (1) or (2), wherein the rubber section is heat-sensitive expanding rubber or water-swelling rubber.
The present invention (4) provides an internal combustion engine, in a cylinder block of which a groove-like cooling water channel is formed, wherein
the cylinder bore wall thermal insulator according to any one of (1) to (3) is set in a groove-like cooling water channel in a one-side half in the groove-like cooling water channel.
The present invention (5) provides an internal combustion engine, a cylinder block of which a groove-like cooling water channel is formed, wherein
the groove-like cooling water channel is partitioned such that the cooling water flowing in the groove-like cooling water channel flows to a groove-like cooling water channel in one one-side half first and, thereafter, flows in a groove-like cooling water channel in another one-side half, and
the cylinder bore wall thermal insulator according to any one of (1) to (3) is set in the groove-like cooling water channel in the other one-side half.
The present invention (6) provides an automobile including the internal combustion engine according to (4) or (5).
According to the present invention, it is possible to improve uniformity of a wall temperature of a cylinder bore wall of an internal combustion engine. Therefore, according to the present invention, it is possible to reduce a difference in a thermal deformation amount on an upper side and a lower side of the cylinder bore wall.
A cylinder bore wall thermal insulator of the present invention and an internal combustion engine of the present invention are explained with reference to
As shown in
In the cylinder block 11, two or more bores 12 are formed side by side in series. Therefore, as the bores 12, there are end bores 12a1 and 12a2 adjacent to one bore and intermediate bores 12b1 and 12b2 sandwiched by two bores (note that, when the number of bores of the cylinder block is two, there are only the end bores). Among bores formed side by side in series, the end bores 12a1 and 12a2 are bores at both ends. The intermediate bores 12b1 and 12b2 are bores present between the end bore 12a1 at one end and the end bore 12a2 at the other end. A wall between the end bore 12a1 and the intermediate bore 12bl, a wall between the intermediate bore 12b1 and the intermediate bore 12b2, and a wall between the intermediate bore 12b2 and the end bore 12a2 (inter-bore walls 7) are portion sandwiched by two bores. Therefore, since heat is transmitted from two cylinder bores, wall temperature is higher than other walls. Therefore, on a wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14, temperature is the highest near the inter-bore walls 7. Therefore, the temperature of a boundary 6 of each bore section and the vicinity of the boundary 6 is the highest in the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14.
In the present invention, in a wall surface of the groove-like cooling water channel 14, a wall surface on the cylinder bore 13 side is described as wall surface 17 on the cylinder bore side of the groove-like cooling water channel. In the wall surface of the groove-like cooling water channel 14, a wall surface on the opposite side of the wall surface 17 on the cylinder bore side of the groove-like cooling water channel is described as wall surface 18.
The cylinder bore wall thermal insulator 20 shown in
When viewed from above, the rubber section 22 is molded into a shape of continuous four arcs. The shape on a contact surface 25 side of the rubber section 22 is a shape conforming to a wall surface on the cylinder bore side of the groove-like cooling water channel 14. The rubber section 22 is a member in direct contact with a wall surface on the cylinder bore side of the groove-like cooling water channel 14 to cover an insulating part of the wall surface on the cylinder bore side of the groove-like cooling water channel 14 and insulate the insulating part. Bending sections 24 formed on the upper side and the lower side of the base section 21 are bent. The rubber section 22 is sandwiched between the base section 21 and the bending sections 24 to thereby be fixed to the base section 21. In the rubber section 22, a surface of the rubber section 22 on the opposite side of the base section 21 side is the contact surface 25 in contact with the wall surface 17 on the cylinder bore side of the groove-like cooling water channel.
The base section 21 is made of a metal plate. When viewed from above, the base section 21 is molded into a shape of continuous four arcs. The shape of the base section 21 is a shape conforming to a rear surface side of the rubber section 22 (a surface on the opposite side of the contact surface 25 side).
The rubber section 22 of the cylinder bore wall thermal insulator 20 includes bore sections 35a1 of the rubber section in contact with a wall surface on the end bore 12a1 side at one end, bore sections 35a2 of the rubber section in contact with a wall surface on the end bore 12a2 side at the other end, and the bore sections 35b1 and 35b2 of the rubber section in contact with a wall surface on the intermediate bores 12b1 and 12b2 side in the wall surface on the bore side of the groove-like cooling water channel 14. The bore sections 35a1 of the rubber section are rubber section for insulating the wall surface on the end bore 12a1 side at one end. The bore sections 35a2 of the rubber section are rubber sections for insulating the wall surface on the end bore 12a2 side at the other end. The bore sections 35b1 and 35b2 of the rubber section are respectively rubber sections for insulating the wall surface on the intermediate bores 12b1 and 12b2 side.
The base section 21 of the cylinder bore wall thermal insulator 20 is formed of one metal plate from the end bore 12a1 side at one end to the end bore 12a2 side at the other end. Therefore, in the base section 21 of the cylinder bore wall thermal insulator 20, bore sections 29a1 of the base body section on the end bore 12a1 side at one end, bore sections 29b1 and 29b2 of the base section on the intermediate bores 12b1 and 12b2 side, and bore sections 29a2 of the base section on the end bore 12a2 side at the other end are connected. A boundary between the bore section 29a1 and 29b1 of the base section is a boundary 30a of each bore section of the base section. A boundary between the bore section 29b1 and 29b2 of the base section is a boundary 30b of each bore section of the base section. A boundary between the bore section 29b2 and 29a2 of the base section is a boundary 30c of each bore section of the base section.
The metal leaf spring 23 formed by being integrally molded with the base section 21 is attached to the base section 21. The material of the metal leaf spring 23 is metal. The metal leaf spring 23 is a tabular elastic body. The metal leaf spring 23 is attached to the base section 21 by being bent from the base section 21 on the other end side 27 connected to the base section 21 such that one end side 26 separates from the base section 21.
The cylinder bore wall thermal insulator 20 includes the vertical walls 28 on the rear surface side. Positions where the vertical walls 28 are set are on a near side of the boundary 30 of each bore section of the base section 21 in a flowing direction of the cooling water when the cylinder bore wall thermal insulator 20 is set in the groove-like cooling water channel of the cylinder block. As a setting range in the up-down direction of the vertical walls 28, a lower end is up to the lower end of the base section 21 and an upper end is up to slightly below the upper end of the base section 21.
Use forms of the cylinder bore wall thermal insulator 20 are explained with reference to
Note that, in the present invention, the wall surface on the one-side half side in the entire wall surface on the cylinder bore side of the groove-like cooling water channel indicates a wall surface in a half on one side at the time when a wall surface on the cylinder bore side of the groove-like cooling water channel is vertically divided into two in the direction in which the cylinder bores are disposed side by side. For example, in
At this time, in the cylinder bore wall thermal insulator 20, the metal leaf springs 23 are attached such that the distance from the contact surface 25 of the rubber section 22 to the one end side 26 of the metal leaf springs 23 is larger than the width of the groove-like cooling water channel 14. Therefore, when the cylinder bore wall thermal insulator 20 is set in the groove-like cooling water channel 14, the metal leaf springs 23 are sandwiched between the base section 21 and the rubber section 22 and the wall surface 18, whereby a force in a direction toward the base section 21 is applied to the one end side 26 of the metal leaf springs 23. Consequently, the metal leaf springs 23 are deformed such that the one end side 26 approaches the base section 21 side. Therefore, a restoring elastic force is generated in the metal leaf spring 23. The base section 21 is pushed by the elastic force toward the wall surface 17 on the cylinder bore side of the groove-like cooling water channel. As a result, the rubber section 22 is pressed against the wall surface 17 on the cylinder bore side of the groove-like cooling water channel by the base section 21. In other words, the cylinder bore wall thermal insulator 20 is set in the groove-like cooling water channel 14, whereby the metal leaf springs 23 are deformed. The base section 21 is urged by a restoring elastic force of the deformation to press the rubber section 22 against the wall surface 17 on the cylinder bore side of the groove-like cooling water channel. In this way, in the cylinder bore wall thermal insulator 20, the rubber section 22 comes into contact with the wall surface 17a in one one-side half in the entire wall surface 17 on the cylinder bore side of the groove-like cooling water channel. The same applies to the cylinder bore wall thermal insulator 40.
At this time, the cylinder bore wall thermal insulator 20 is set in the groove-like cooling water channel 14a in one one-side half. The vertical walls 28 are set on the rear surface side of the cylinder bore wall thermal insulator 20. When focusing on the bore sections 29b2 of the base section, the boundary 30c to the boundary 30b of each bore section of the base section are the bore sections 29b2 of the base section. The vertical walls 28b are set on the rear surface side of the bore sections 29b2 of the base section. In the groove-like cooling water channel 14a in one one-side half, the cooling water is flowing from the boundary 30c to the boundary 30b. Therefore, the vertical wall 28b is set on the near side of the boundary 30b of each bore section of the base section in the flowing direction of the cooling water. Most of the cooling water flowing on the rear surface side of the bore sections 29b2 of the base section hits the vertical wall 28b set before the boundary 30b of each core section of the base section.
Note that, in the form example shown in
A flow of the cooling water on the rear surface side of the base section 21 in the groove-like cooling water channel 14a, in which the cylinder bore wall thermal insulator 20 is set, is explained in detail.
The cooling water flowing on the rear surface side of the cylinder bore wall thermal insulator 20, in other words, in the middle and lower part of the groove-like cooling water channel has lower temperature compared with the cooling water flowing in the upper part of the groove-like cooling water channel. Therefore, with the cylinder bore wall thermal insulator 20, it is possible to cause, with the vertical wall 28, the cooling water on the rear surface side of the cylinder bore wall thermal insulator 20 having the low temperature to flow into the boundary 6 between the bore walls of the cylinder bores in the upper part where temperature is the highest in the wall surface on the cylinder bore side of the groove-like cooling water channel. Therefore, the cylinder bore wall thermal insulator 20 has high cooling efficiency of the wall surface on the cylinder bore side in the upper part of the groove-like cooling water channel.
Note that, as shown in
The cylinder bore wall thermal insulator 20 is manufactured by, for example, a method shown in
First, cut-off portions 32 and 33 indicated by dotted lines are cut off from a rectangular metal plate 34 shown in
Subsequently, as shown in
Subsequently, as shown in
Subsequently, as shown in
Another form example of the cylinder bore wall thermal insulator of the present invention is explained with reference to
The cylinder bore wall thermal insulator 56 is, for example, a thermal insulator for insulating the wall surface 17a on the cylinder bore side of the groove-like cooling water channel in one one-side half of the cylinder block 11 shown in
In the cylinder bore wall thermal insulator 56, a contact surface 46 of a rubber section 51 faces the wall surface side on the cylinder bore side of the groove-like cooling water channel. The bore wall insulating sections 55 are fixed such that the contact surface 46 of the rubber section 51 can come into contact with the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14. On the rear surface side of the cylinder bore wall thermal insulator 56, metal leaf springs 59 attached to the bore wall insulating sections 55 project toward the opposite side of the rubber section 51 through openings 62 of the base section 54. Projecting distal ends 63 of the metal leaf springs 59 come into contact with the wall surface 18 on the opposite side of the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14.
The bore wall insulating sections 55 fixed to the cylinder bore wall thermal insulator 56 include, as shown in
The rubber section 51 is molded into an arcuate shape when viewed from above. A shape on the contact surface 46 side of the rubber section 51 is a shape conforming to the wall surface on the cylinder bore side of the groove-like cooling water channel 14. The rubber section 51 is a member directly in contact with the bore sections of the wall surface on the cylinder bore side of the groove-like cooling water channel to cover insulating parts of the bore sections of the wall surface on the cylinder bore side of the groove-like cooling water channel and insulate the bore sections of the wall surface on the cylinder bore side of the groove-like cooling water channel. The rear surface pressing member 52 is molded into an arcuate shape when viewed from above. The rear surface pressing member 52 has a shape conforming to the rear surface side (a surface on the opposite side of the contact surface 46 side) of the rubber section 51 such that the entire rubber section 51 can be pressed from the rear surface side of the rubber section 51. The metal-leaf-spring attaching member 53 is molded into an arcuate shape when viewed from above. The metal-leaf-spring attaching member 53 has a shape conforming to the rear surface side (a surface on the opposite side of the rubber member 51) of the rear surface pressing member 52. The metal leaf spring 59, which is an elastic member, is attached to the metal-leaf-spring attaching member 53. The metal leaf spring 59 is a vertically long rectangular metal plate. One end in the longitudinal direction of the metal leaf spring 59 is connected to the metal-leaf-spring attaching member 53. The metal leaf spring 59 is attached to the metal-leaf-spring attaching member 53 by being bent from the metal-leaf-spring attaching member 53 on the other end side 64 connected to the metal-leaf-spring attaching member 53 such that a distal end 63 separates from the metal-leaf-spring attaching member 53. The bending sections 60 formed on the upper side and the lower side of the metal-leaf-spring attaching member 53 are bent. The rubber section 51 and the rear surface pressing member 52 are fixed to the metal-leaf-spring attaching member 53 by being sandwiched between the metal-leaf-spring attaching member 53 and the bending sections 60. In the rubber section 51, the surface of the rubber section 51 on the opposite side of the rear surface pressing member 52 side is a contact surface 56 that is in contact with the wall surface 17 on the cylinder bore side of the groove-like cooling water channel.
The bore wall insulating sections 55 are members for insulating the bore walls of the cylinder bores. When the cylinder bore wall thermal insulator 56 is set in the groove-like cooling water channel 14 of the cylinder block 11, the rubber section 51 comes into contact with the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14 and covers the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14. The rear surface pressing member 52 presses, with an urging force of the metal leaf spring 59, which is the elastic member, the rubber 51 toward the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14 from the rear surface side and causes the rubber section 51 to adhere to the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14, whereby the bore wall insulating sections 55 insulates the bore walls of the cylinder bores.
The base section 54 is molded into a shape of continuous four arcs when viewed from above. The shape of the base section 54 is a shape conforming to a one-side half of the groove-like cooling water channel 14. In the base section 54, the openings 62 are formed such that the metal leaf springs 59 attached to the bore wall insulating sections 55 can pass through the base section 54 from the rear surface side of the cylinder bore wall thermal insulator 56 and project toward the wall surface 18 on the opposite side of the wall surface 17 on the cylinder bore side of the groove-like cooling water channel 14.
The base section 54 is a member to which the bore wall insulating sections 55 are fixed. The base section 54 plays a role of deciding positions of the bore wall insulating sections 55 such that the positions of the bore wall insulating sections 55 do not deviate in the groove-like cooling water channel 14. The base section 54 is formed by a continuous metal plate from one end side to the other end side when viewed from above.
The cylinder bore wall thermal insulator 56 includes the vertical wall 28 on the rear surface side. A position where the vertical wall 28 is provided is on the near side of the boundary 30 of each bore section of the base section 54 in the flowing direction of the cooling water when the cylinder bore wall thermal insulator 56 is set in the groove-like cooling water channel of the cylinder block. As a setting range in the up-down direction of the vertical wall 28, a lower end is up to the lower end of the base section 54 and an upper end is up to slightly below the upper end of the base section 54.
A manufacturing procedure of the cylinder bore wall thermal insulator 56 is explained. As shown in
A cylinder bore wall thermal insulator of the present invention is a cylinder bore wall thermal insulator set in a groove-like cooling water channel of a cylinder block of an internal combustion engine including cylinder bores to insulate a bore wall in a one-side half of bore walls of all the cylinder bores.
The thermal insulator includes one or more rubber sections in contact with a wall surface on the cylinder bore side of the groove-like cooling water channel to cover the wall surface on the cylinder bore side of the groove-like cooling water channel, a base section having a shape conforming to a shape of the one-side half of the groove-like cooling water channel, the one or more rubber sections or one or more members to which the one or more rubber sections are fixed being fixed to the base section, and one or more elastic members for urging the entire one or more rubber sections to be pressed from a rear surface side toward the wall surface on the cylinder bore side of the groove-like cooling water channel.
The thermal insulator includes a vertical wall on a near side of a boundary of each bore section of the base section in a flowing direction of cooling water.
The cylinder bore wall thermal insulator of the present invention is set in the groove-like cooling water channel of the cylinder block of the internal combustion engine. The cylinder block in which the cylinder bore wall thermal insulator of the present invention is set is a cylinder block of an open deck type in which two or more cylinder bores are formed side by side in series. When the cylinder block is the cylinder block of an open deck type in which two cylinder bores are formed side by side in series, the cylinder block includes cylinder bores including two end bores. When the cylinder block is a cylinder block of an open deck type in which three or more cylinder bores are formed side by side in series, the cylinder block includes cylinder bores including two end bores and one or more intermediate bores. Note that, in the present invention, among the cylinder bores formed in series, bores at both ends are referred to as end bores and a bore sandwiched by other cylinder bores on both sides is referred to as intermediate bore.
A position where the cylinder bore wall thermal insulator of the present invention is set is a groove-like cooling water channel. In many internal combustion engines, a position equivalent to a middle and lower part of the groove-like cooling water channel of the cylinder bore is a position where the speed of a piston increases. Therefore, it is desirable to insulate the middle and lower part of the groove-like cooling water channel. In
The cylinder bore wall thermal insulator of the present invention is a thermal insulator for insulating a wall surface in a one-side half in the entire wall surface on the cylinder bore side of the groove-like cooling water channel. In other words, the cylinder bore wall thermal insulator of the present invention is a thermal insulator for insulating a bore wall in a one-side half of bore walls of all the cylinder bores.
The cylinder bore wall thermal insulator of the present invention includes one or more rubber sections, a base section, and one or more elastic members.
The rubber section is a member that is direct in contact with the wall surface on the cylinder bore side of the groove-like cooling water channel, covers the wall surface on the cylinder bore side of the groove-like cooling water channel, and insulates the cylinder bore wall. A member covering the rear surface side of the rubber section is pushed by an urging force of the elastic member. The rubber section is pressed against the wall surface on the cylinder bore side of the groove-like cooling water channel by the member. Therefore, the rubber section is molded into a shape conforming to the wall surface on the cylinder bore side of the groove-like cooling water channel when viewed from above. The shape of the rubber section viewed from a side is selected as appropriate according to a portion of the wall surface on the cylinder bore side of the groove-like cooling water channel covered by the rubber section.
Examples of the material of the rubber section include rubber such as solid rubber, expanding rubber, foamed rubber, and soft rubber and silicone-based gelatinous material. Heat-sensitive expanding rubber or water-swelling rubber that can expand a rubber member portion in the groove-like cooling water channel after setting of the cylinder bore wall thermal insulator is desirable in that the rubber member can strongly come into contact with the cylinder bore wall and prevent the rubber member from being shaved when the cylinder bore wall thermal insulator is set in the groove-like cooling water channel.
Examples of a composition of the solid rubber include natural rubber, butadiene rubber, ethylene propylene diene rubber (EPDM), nitrile butadiene rubber (NBR), silicone rubber, and fluorocarbon rubber.
Examples of the expanding rubber include heat-sensitive expanding rubber. The heat-sensitive expanding rubber is a composite body obtained by impregnating a thermoplastic substance having a lower melting point than a base form material in the base form material and compressing the thermoplastic substance. The heat-sensitive expanding rubber is a material, a compressed state of which is maintained by a hardened object of the thermoplastic substance present at least in a surface layer part thereof at the normal temperature and is released when the hardened object of the thermoplastic substance is softened by heating. Examples of the heat-sensitive expanding rubber include heat-sensitive expanding rubber described in Japanese Patent Laid-Open No. 2004-143262. When the material of the rubber member is the heat-sensitive expanding rubber, the cylinder bore wall thermal insulator of the present invention is set in the groove-like cooling water channel and heat is applied to the heat-sensitive expanding rubber, whereby the heat-sensitive expanding rubber expands to be deformed into a predetermined shape.
Examples of the base form material related to the heat-sensitive expanding rubber include various polymeric materials such as rubber, elastomer, thermoplastic resin, and thermosetting resin. Specifically, examples of the base form material include natural rubber, various synthetic rubbers such as chloropropylene rubber, styrene butadiene rubber, nitrile butadiene rubber, ethylene propylene diene terpolymer, silicone rubber, fluorocarbon rubber, and acrylic rubber, various elastomers such as soft urethane, and various thermosetting resins such as hard urethane, phenolic resin, and melamine resin.
As the thermoplastic substance related to the heat-sensitive expanding rubber, a thermoplastic substance, any one of a glass transition point, a melting point, and a softening temperature of which is lower than 120° C., is desirable. Examples of the thermoplastic substance related to the heat-sensitive expanding rubber include thermoplastic resin such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic ester, styrene butadiene copolymer, chlorinated polyethylene, polyvinylidene fluoride, ethylene-vinyl acetate copolymer, ethylene vinyl chloride acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, nylon, acrylonitrile-butadiene copolymer, polyacrylonitrile, polyvinyl chloride, polychloroprene, polybutadiene, thermoplastic polyimide, polyacetal, polyphenylene sulfide, polycarbonate, and thermoplastic polyurethane and various thermoplastic compounds such as low-melting point glass flit, starch, solder, and wax.
Examples of the expanding rubber include water-swelling rubber. The water swelling rubber is a material obtained by adding a water-absorbing substance to rubber and is a rubber material that absorbs water and swells and has firmness for retaining an expanded shape. Examples of the water-swelling rubber include rubber materials obtained by adding water-absorbing materials such as a crosslinking substance of a polyacrylic acid neutralized product, starch acrylic acid graft copolymer cross linking substance, cross-linked carboxymethyl cellulose salt, and polyvinyl alcohol to rubber. Examples of the water-swelling rubber include water-swelling rubber containing ketimine polyamide resin, glycidyl ethers, water-absorbing resin, and rubber described in Japanese Patent Laid-Open No. 9-208752. When the material of the rubber member is the water-swelling rubber, the cylinder bore wall thermal insulator of the present invention is set in the groove-like cooling water channel and the cooling water is fed and the water-swelling rubber absorbs the water, whereby the water-swelling rubber expands to be deformed into a predetermined shape.
The foamed rubber is porous rubber. Examples of the foamed rubber include sponge-like foamed rubber having an open-cell structure, foamed rubber having a closed-cell structure, and a semi-independent foamed rubber. Examples of the material of the foamed rubber include ethylene propylene diene terpolymer, silicone rubber, nitrile butadiene copolymer, silicone rubber, and fluorocarbon rubber. An expansion ratio of the foamed rubber is not particularly limited and is selected as appropriate. It is possible adjust a water content of the rubber member by adjusting the expansion ratio. Note that the expansion ratio of the foamed rubber indicates a density ratio before and after foaming represented by ((pre-foaming density−post-foaming density)/pre-foaming density)×100.
When the material of the rubber section is a material that can contain water such as the water-swelling rubber or the foamed rubber, when the cylinder bore wall thermal insulator of the present invention is set in the groove-like cooling water channel and the cooling water is fed to the groove-like cooling water channel, the rubber section contains water. In which range the water content of the rubber section is set when the cooling water is fed to the groove-like cooling water channel is selected as appropriate according to operation conditions and the like of the internal combustion engine. Note that the water content indicates a weight water content represented by (cooling water weight/(filler weight+cooling water weight))×100.
Note that the rubber section may have a shape covering a plurality of bore sections of the wall surface on the cylinder bore side of the groove-like cooling water channel as in the form example shown in
The thickness of the rubber member is not particularly limited and is selected as appropriate.
The base section is a member to which the rubber section or a member to which the rubber section is fixed is fixed. In other words, the base section is a member to which the rubber section is directly fixed or indirectly fixed via another member. Examples of a form example in which the rubber section is directly fixed to the base section include a form example in which, as in the form example shown in
The base section is a member for deciding a position of the rubber section such that the position of the rubber section in the groove-like cooling water channel does not deviate. Therefore, the base section has a shape conforming to the groove-like cooling water channel and continues from one end side to the other end side. The base section is molded into a shape of continuous arcs when viewed from above. Examples of the material of the base section include a metal plate of stainless steel (SUS), an aluminum alloy, or the like and synthetic resin. Note that, when the base section is made of the metal plate, the base section may be manufactured by molding one metal plate or may be manufactured by connecting a plurality of metal plates if the base section continues from one end side to the other end side. When the base section is made of the synthetic resin, the base section is usually an integrally molded body.
The elastic member is a member that is elastically deformed when the cylinder bore wall thermal insulator of the present invention is set in the groove-like cooling water channel and urges the rubber section with an elastic force to be pressed toward the wall surface on the cylinder bore side of the groove-like cooling water channel.
A form of the elastic member is not particularly limited. Examples of the form of the elastic member include a tabular elastic member, a coil-like elastic member, a leaf spring, a torsion spring, and elastic rubber. The material of the elastic member is not particularly limited. However, stainless steel (SUS), an aluminum alloy, or the like is desirable because LLC resistance is high and strength is high. As the elastic member, a metal elastic member such as a metal leaf spring, a coil spring, a leaf spring, or a torsion spring is desirable. When the elastic member is the metal leaf spring, it is desirable that a portion in contact with the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-like cooling water channel and the vicinity of the portion are molded into a curved surface shape swelling to the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-like cooling water channel because it is possible to prevent the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-like cooling water channel from being damaged by a contact portion with the wall surface of the elastic member when the cylinder bore wall thermal insulator of the present invention is inserted in to the groove-like cooling water channel. In other words, in the metal leaf spring, which is the elastic member, a distal end portion in contact with the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-like cooling water channel is formed in a curved surface shape swelling to the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-like cooling water channel.
In the cylinder bore wall thermal insulator of the present invention, a form, a shape, a size, a setting position, a setting number, and the like of the elastic members are selected as appropriate according to the shape and the like of the groove-like cooling water channel such that the rubber section is urged by an appropriate pressing force by the elastic members when the thermal insulator is set in the groove-like cooling water channel.
In the cylinder bore wall thermal insulator 20 shown in
The cylinder bore wall thermal insulator of the present invention includes the vertical wall on the rear surface side of the base section. The vertical wall plays a role of directing the cooling water flowing on the rear surface side of the cylinder bore wall thermal insulator of the present invention (in other words, the cooling water flowing in the middle and lower part of the groove-like cooling water channel) toward the upper part of the groove-like cooling water channel before the boundary of each bore section of the base section (in other words, before the boundary of each bore section of the wall surface on the cylinder bore side of the groove-like cooling water channel) and feeding the cooling water flowing on the rear surface side of the cylinder bore wall thermal insulator of the present invention to the upper part of the boundary of each bore section of the wall surface on the cylinder bore side of the groove-like cooling water channel or the vicinity of the upper part.
In the cylinder bore wall thermal insulator of the present invention, a setting position of the vertical wall when viewed from the above is the rear surface side of the base section and, in the flowing direction of the cooling water, the near side of the boundary of each bore section of the base section. The setting position of the vertical wall is explained with reference to
In the cylinder bore wall thermal insulator of the present invention, the setting position of the vertical wall when viewed from above only has to be before the boundary of each bore section of the base section in the flowing direction of the cooling water and have a distance from the boundary of each bore section of the base section in a degree for achieving the effect of the present invention. The setting position is selected as appropriate. Note that, in the present invention, as shown in
In the cylinder bore wall thermal insulator of the present invention, the setting range of the vertical wall in the up-down direction is selected as appropriate according to the setting of a cooling range in the upper part of the cylinder bore wall by the cooling water. In other words, the cooling range in the upper part of the cylinder bore wall by the cooling water is set. The vertical wall is set in a range further on the lower side than the cooling range. Therefore, the position of the upper end of the vertical wall is above the upper end of the base section in some cases and is the same position as the upper end of the base section or below the upper end of the base section in other cases. The position of the upper end of the vertical wall is selected as appropriate according to the setting of the cooling range in the upper part of the cylinder bore wall by the cooling water. The position of the lower end of the vertical wall is selected as appropriate in a range in which most of the cooling water flowing on the rear surface side of the cylinder bore wall thermal insulator of the present invention hits the vertical wall and changes the flow upward and the effect of the present invention is achieved. In other words, the position of the lower end of the vertical wall may be the same position as the lower end of the base section or may be above the lower end of the base section.
When there is no gap or a gap is very small between the vertical wall and the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-like cooling water channel, a pressure loss in the groove-like cooling water channel is excessively large. Therefore, in the cylinder bore wall thermal insulator of the present invention, the width (in
In the cylinder bore wall thermal insulator of the present invention, a setting number of the vertical walls is selected as appropriate. For example, as in the form example shown in
In the cylinder bore wall thermal insulator of the present invention, the base section and the vertical wall are desirably formed of a metal plate because it is easy to fix the vertical wall to the base section.
In the form example shown in
The cylinder bore wall thermal insulator of the present invention can include a cooling-water-flow partitioning member on one end side. In
As in the form example shown in
An internal combustion engine according to a first aspect of the present invention is an internal combustion engine, in a cylinder block of which a groove-like cooling water channel is formed.
The cylinder bore wall thermal insulator of the present invention is set in a groove-like cooling water channel in a one-side half in the groove-like cooling water channel.
An internal combustion engine according to a second aspect of the present invention is an internal combustion engine, a cylinder block of which a groove-like cooling water channel is formed.
The groove-like cooling water channel is partitioned such that the cooling water flowing in the groove-like cooling water channel flows to a groove-like cooling water channel in one one-side half first and, thereafter, flows in a groove-like cooling water channel in another one-side half.
The cylinder bore wall thermal insulator of the present invention is set in the groove-like cooling water channel in the other one-side half (the one-side half in the latter half). The internal combustion engine according to the second aspect of the present invention may include the cylinder bore wall thermal insulator in the groove-like cooling water channel in the one one-side half (the one-side half in the former half) or may not include the cylinder bore wall thermal insulator.
An automobile of the present invention is an automobile including the internal combustion engine according to the first aspect or the second aspect of the present invention.
According to the present invention, it is possible to reduce a difference in a deformation amount between the upper side and the lower side of the cylinder bore wall of the internal combustion engine. Therefore, since the friction of the piston can be reduced, it is possible to provide a fuel-saving internal combustion engine.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-217809 | Nov 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/082726 | 11/4/2016 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/078117 | 5/11/2017 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4569313 | Nobu | Feb 1986 | A |
| 4616600 | Hirano | Oct 1986 | A |
| 5558048 | Suzuki | Sep 1996 | A |
| 20050217614 | Matsutani | Oct 2005 | A1 |
| 20050235930 | Xin | Oct 2005 | A1 |
| 20080060593 | Nakada | Mar 2008 | A1 |
| 20090194046 | Shikida | Aug 2009 | A1 |
| 20090266315 | Hanai | Oct 2009 | A1 |
| 20100031902 | Alyanak | Feb 2010 | A1 |
| 20100242868 | Shikida | Sep 2010 | A1 |
| 20110114040 | Hashimoto | May 2011 | A1 |
| 20110114041 | Hamakawa | May 2011 | A1 |
| 20110114042 | Hamakawa | May 2011 | A1 |
| 20110114043 | Hamakawa | May 2011 | A1 |
| 20110132295 | Hamakawa | Jun 2011 | A1 |
| 20110214630 | Weed | Sep 2011 | A1 |
| 20120132157 | Matsuki | May 2012 | A1 |
| 20120204821 | Tofukuji | Aug 2012 | A1 |
| 20130160725 | Nishio | Jun 2013 | A1 |
| 20150075454 | Hamakawa | Mar 2015 | A1 |
| 20150240743 | Nishio | Aug 2015 | A1 |
| 20150285125 | Hayman | Oct 2015 | A1 |
| 20160017838 | Nishio | Jan 2016 | A1 |
| 20160195000 | Nakashima | Jul 2016 | A1 |
| 20170022929 | Karita | Jan 2017 | A1 |
| 20170030289 | Okawa | Feb 2017 | A1 |
| 20170045012 | Okawa | Feb 2017 | A1 |
| 20180355780 | Fujita | Dec 2018 | A1 |
| 20180363587 | Yoshimura | Dec 2018 | A1 |
| 20190032595 | Yoshimura | Jan 2019 | A1 |
| Number | Date | Country |
|---|---|---|
| 9-208752 | Aug 1997 | JP |
| 2004-143262 | May 2004 | JP |
| 2005-120944 | May 2005 | JP |
| 2005-315118 | Nov 2005 | JP |
| 2005315118 | Nov 2005 | JP |
| 2007-247590 | Sep 2007 | JP |
| 2008-31939 | Feb 2008 | JP |
| 2008128133 | Jun 2008 | JP |
| 2008-208744 | Sep 2008 | JP |
| 2012007478 | Jan 2012 | JP |
| 2013-217343 | Oct 2013 | JP |
| 2014-92031 | May 2014 | JP |
| 2014194219 | Oct 2014 | JP |
| 2015156207 | Oct 2015 | WO |
| WO-2015156207 | Oct 2015 | WO |
| WO-2015156208 | Oct 2015 | WO |
| Entry |
|---|
| International Search Report dated Dec. 27, 2016, issued in counterpart International Application No. PCT/JP2016/082726 (2 pages). |
| Extended (supplementary) European Search Report dated May 17, 2019, issued in counterpart EP Application No. 16862177.9. (7 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20180328277 A1 | Nov 2018 | US |
