WO2018225733A1

WO2018225733A1 - Cylinder bore wall warming tool

Info

Publication number: WO2018225733A1
Application number: PCT/JP2018/021562
Authority: WO
Inventors: 佐藤　絢也
Original assignee: ニチアス株式会社
Priority date: 2017-06-07
Filing date: 2018-06-05
Publication date: 2018-12-13

Abstract

This cylinder bore wall warming tool comprises: a substrate member shaped so as to surround the entire periphery of the wall surface of a groove-shaped coolant channel on the cylinder bore side when viewed from above; a first expanding rubber which is secured to the inside of the substrate member, contacts the wall surface of the groove-shaped coolant channel on the cylinder bore side by expanding inside the groove-shaped coolant channel, warms the bore wall of the cylinder bore, and presses one half of the substrate member on one side thereof toward the wall surface on the opposite side of the groove-shaped coolant channel from the wall surface on the cylinder bore side; and a second expanding rubber which is secured to the inside of the substrate member, contacts the wall surface of the groove-shaped coolant channel on the cylinder bore side by expanding inside the groove-shaped coolant channel, warms the bore wall of the cylinder bore, and presses the other half of the substrate member toward the wall surface on the opposite side of the groove-shaped coolant channel from the wall surface on the cylinder bore side. As a result, the present invention provides an easily producible cylinder bore wall warming tool which is capable of warming a cylinder bore wall and is unlikely to cause a positional shift caused by vibrations or coolant flow.

Description

[Name of invention determined by ISA based on Rule 37.2] Insulator for cylinder bore wall

The present invention relates to a heat insulator arranged in contact with a wall surface on the grooved coolant flow path side of a cylinder bore wall of a cylinder block of an internal combustion engine, an internal combustion engine including the same, and an automobile having the internal combustion engine.

In the internal combustion engine, fuel explosion occurs at the top dead center of the piston in the bore, and the piston is pushed down by the explosion, so that the temperature is higher on the upper side of the cylinder bore wall and the temperature is lower on the lower side. Therefore, there is a difference in the amount of thermal deformation between the upper side and the lower side of the cylinder bore wall, and the upper side expands greatly, while the lower side expansion decreases.

As a result, the frictional resistance with the cylinder bore wall of the piston increases, and this is a factor that lowers fuel consumption. Therefore, it is required to reduce the difference in thermal deformation between the upper side and the lower side of the cylinder bore wall. .

Therefore, conventionally, in order to make the wall temperature of the cylinder bore wall uniform, a spacer is installed in the grooved cooling water flow path, and the flow of the cooling water in the grooved cooling water flow path is adjusted so that the cylinder bore wall caused by the cooling water Attempts have been made to control the cooling efficiency on the upper side and the cooling efficiency on the lower side. For example, Patent Document 1 discloses a flow that divides a groove-shaped cooling heat medium flow path into a plurality of flow paths by being disposed in a groove-shaped cooling heat medium flow path formed in a cylinder block of an internal combustion engine. A channel partition member formed at a height less than a depth of the groove-shaped cooling heat medium flow path, and a bore-side flow path and an anti-bore-side flow path in the groove-shaped cooling heat medium flow path A flow path dividing member serving as a wall portion that is divided into a groove portion, a groove portion that is formed from the flow path dividing member toward the opening of the groove-shaped cooling heat medium flow channel, and a leading edge is the groove-shaped cooling heat medium. By being formed of a flexible material so as to extend beyond one inner surface of the flow path, the end edge portion is caused by its own bending restoring force after completion of insertion into the grooved cooling heat medium flow path. By contacting the inner surface at the intermediate position in the depth direction of the grooved cooling heat medium flow path, A flexible lip member that separates the A-side passage, the internal combustion engine cooling heat medium flow passage partition member comprising the disclosed.

JP 2008-31939 A (Claims)

However, since the internal combustion engine cooling heat medium flow path partition member disclosed in the cited document 1 cannot be strongly pressed against the cylinder bore wall, there is a problem that it moves in the grooved coolant flow path due to engine vibration.

Also, the cylinder bore wall heat insulator is required to be easily prepared from the viewpoint of manufacturing cost.

Accordingly, an object of the present invention is to provide a cylinder bore wall heat insulator that can keep the cylinder bore wall warm, hardly cause displacement due to vibration or the flow of cooling water, and can be easily manufactured. .

The problems in the above prior art are solved by the present invention described below.
That is, the present invention (1) is a cylinder bore wall heat insulator that is installed in a grooved coolant flow path of a cylinder block of an internal combustion engine having a cylinder bore and heats the bore walls of all the cylinder bores.
When viewed from above, a base member having a shape surrounding the wall surface on the cylinder bore side of the groove-like cooling water flow channel over the entire circumference;
It is fixed inside the base member, and expands in the grooved cooling water flow path to contact the wall surface of the grooved cooling water flow path on the cylinder bore side to keep the bore wall of the cylinder bore warm. A first inflating rubber that pushes one half of the first toward the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-shaped cooling water flow path;
It is fixed inside the base member, and expands in the grooved cooling water flow path to contact the wall surface of the grooved cooling water flow path on the cylinder bore side to keep the bore wall of the cylinder bore warm. A second expansion rubber that pushes the other half on the opposite side of the wall surface on the cylinder bore side of the groove-shaped cooling water flow path,
Consisting of,
A cylinder bore wall heat insulator characterized by the above is provided.

Further, in the present invention (2), the expanded rubber is a heat-sensitive expanded rubber composed of a base foam material and a thermoplastic substance, and the base foam material is made of silicon rubber, fluorine rubber, natural rubber, butadiene rubber, It is ethylene propylene diene rubber or nitrile butadiene rubber, and the thermoplastic substance is a resin or a metal material.

Further, the present invention (3) provides the heat insulator for the cylinder bore wall according to either (1) or (2), wherein the base member is made of a synthetic resin.

Further, in the present invention (4), the ratio ((t _i / t ₀ ) × 100) of the thickness (t _i ) of the expanded rubber before expansion to the open thickness (t ₀ ) of the expanded rubber is 12 The heat insulating device for a cylinder bore wall according to any one of (1) to (3), characterized in that it is ˜80%.

According to the present invention, it is possible to provide a warmer for a cylinder bore wall that can keep the cylinder bore wall warm, hardly cause displacement due to vibration or the flow of cooling water, and can be easily manufactured.

It is a typical top view which shows the form example of the cylinder block in which the heat insulating tool of the cylinder bore wall of this invention is installed. FIG. 2 is a sectional view taken along line XX in FIG. It is a perspective view of the cylinder block shown in FIG. It is a typical top view which shows the form example of the cylinder block in which the heat insulating tool of the cylinder bore wall of this invention is installed. It is a typical perspective view which shows the form example of the heat insulating tool of the cylinder bore wall of this invention. It is the top view which looked at the heat insulating tool of the cylinder bore wall shown in FIG. 5 from the upper side. FIG. 7 is a cross-sectional view taken along line YY in FIG. 6. It is a schematic diagram which shows a mode that the heat insulator 36a of a cylinder bore wall is installed in the cylinder block 11 shown in FIG. It is a schematic diagram which shows a mode after installing the thermal insulation 36a of a cylinder bore wall in the groove-shaped cooling water flow path 14 of the cylinder block 11 shown in FIG. 1, and before an expansion rubber expand | swells. It is a schematic diagram which shows a mode that the expansion | swelling rubber | gum of the heat insulating tool 36a of a cylinder bore wall expands in the groove-shaped cooling water flow path 14 of the cylinder block 11 shown in FIG. It is an end view of the heat insulator 36a on the cylinder bore wall. It is a typical perspective view which shows the other example of a heat retention tool of the cylinder bore wall of this invention. It is the top view which looked at the heat insulating tool of the cylinder bore wall shown in FIG. 12 from the upper side.

Referring to FIGS. 1 to 11, the cylinder bore wall heat insulator of the present invention and the internal combustion engine of the present invention will be described. 1 to 4 show an example of a cylinder block in which a cylinder bore wall heat insulator of the present invention is installed. FIGS. 1 and 4 show a cylinder in which a cylinder bore wall heat insulator of the present invention is installed. FIG. 2 is a schematic plan view showing the block, FIG. 2 is a sectional view taken along line XX of FIG. 1, and FIG. 3 is a perspective view of the cylinder block shown in FIG. FIG. 5 is a schematic perspective view showing an example of a form of a heat insulator for a cylinder bore wall according to the present invention. FIG. 6 is a view of the heat insulator 36a in FIG. 5 as viewed from above. 7 is a cross-sectional view taken along line YY of FIG. FIG. 8 is a schematic diagram showing a state in which the heat insulator 36a on the cylinder bore wall is inserted into the cylinder block 11 shown in FIG. FIG. 9 is a schematic view showing a state after the thermal insulation 36a on the cylinder bore wall is installed in the groove-like cooling water flow path 14 of the cylinder block 11 shown in FIG. 1 and before the expanded rubber is expanded. 10 is a schematic view showing a state in which the cylinder bore wall heat insulator 36a is installed in the cylinder block 11 shown in FIG. 1, and FIG. 10 (A) is an end view taken along the line ZZ in FIG. It is a figure which shows a mode before expansion | swelling rubber | gum is expanded, (B) is a figure which shows a mode after expansion | swelling rubber | gum is expanded.

As shown in FIGS. 1 to 3, an open deck type cylinder block 11 of a vehicle-mounted internal combustion engine in which a cylinder bore wall heat insulator is installed is provided with a bore 12 for moving a piston up and down and a cooling water flow. The groove-shaped cooling water flow path 14 is formed. A wall that separates the bore 12 and the grooved coolant flow path 14 is a cylinder bore wall 13. Further, the cylinder block 11 is formed with a cooling water supply port 15 for supplying cooling water to the grooved cooling water flow channel 11 and a cooling water discharge port 16 for discharging cooling water from the grooved cooling water flow channel 11. ing.

The cylinder block 11 is formed so that two or more bores 12 are arranged in series. Therefore, the bore 12 has end bores 12a1 and 12a2 adjacent to one bore and intermediate bores 12b1 and 12b2 sandwiched between the two bores (note that the number of bores in the cylinder block is two). In the case, only the end bore.) Of the bores arranged in series, the end bores 12a1 and 12a2 are bores at both ends, and the intermediate bores 12b1 and 12b2 are bores 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 12b1, 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 wall 191) are sandwiched between two bores. Therefore, since heat is transmitted from the two cylinder bores, the wall temperature is higher than other walls. Therefore, in the wall surface 17 on the cylinder bore side of the grooved cooling water flow path 14, the temperature is highest in the vicinity of the inter-bore wall 191. The temperature at the wall boundary 192 and its vicinity is highest.

In the present invention, among the wall surfaces of the grooved cooling water flow path 14, the wall surface on the cylinder bore 13 side is referred to as the cylinder bore wall 17 of the grooved cooling water flow path, and among the wall surfaces of the grooved cooling water flow path 14, the groove shape A wall surface on the opposite side of the cooling water passage from the cylinder bore wall 17 is referred to as a counter wall 18 of the cylinder bore wall.

In the present invention, the half on one side refers to a half on one side when the cylinder block is vertically divided into two in the direction in which the cylinder bores are arranged. Therefore, in the present invention, one half of the bore walls of all cylinder bores refers to one half of the bore wall when the whole cylinder bore wall is vertically divided into two in the direction in which the cylinder bores are arranged. For example, in FIG. 4, the direction in which the cylinder bores are lined up is the ZZ direction, and each of the half walls on one side when the two halves are vertically divided by the ZZ line represents the bore walls of all the cylinder bores. It is a half-bore wall on one side. That is, in FIG. 4, the one-side half bore wall 20a from the ZZ line is the one-side half bore wall 21a out of the bore walls of all cylinder bores, and the one-side half 20b from the ZZ line. This bore wall is the other half wall bore 21b of the bore walls of all cylinder bores.

In the present invention, the bore wall of each cylinder bore refers to each bore wall portion corresponding to each cylinder bore. In FIG. 4, the range indicated by the double arrow 22a1 is the bore wall 23a1 of the cylinder bore 12a1, The range indicated by the double arrow 22b1 is the bore wall 23b1 of the cylinder bore 12b1, the range indicated by the double arrow 22b2 is the bore wall 23b2 of the cylinder bore 12b2, and the range indicated by the double arrow 22a2 is the bore wall 23a2 of the cylinder bore 12a2. The range indicated by the double arrow 22b3 is the bore wall 23b3 of the cylinder bore 12b1, and the range indicated by the double arrow 22b4 is the bore wall 23b4 of the cylinder bore 12b2. That is, the bore wall 23a1 of the cylinder bore 12a1, the bore wall 23b1 of the cylinder bore 12b1, the bore wall 23b2 of the cylinder bore 12b2, the bore wall 23a2 of the cylinder bore 12a2, the bore wall 23b3 of the cylinder bore 12b1, and the bore wall 23b4 of the cylinder bore 12b2, respectively. Bore wall.

The cylinder bore wall heat insulator 36a shown in FIG. 5 is a heat insulator for keeping the bore wall 21 over the entire circumference in FIG. A cooling water flow partition member 38 is attached to the heat insulator 36a on the cylinder bore wall. In the cylinder block 11 shown in FIG. 4, the cooling water flow partition member 38 immediately discharges the cooling water supplied from the cooling water supply port 15 to the grooved cooling water channel 14 from the cooling water discharge port 16 in the vicinity. First, the one-half half groove-like cooling water flow path 14 on the 20b side flows toward the end opposite to the position of the cooling water supply port 15, and the one-half half groove-like cooling water flow path 14 on the 20b side When it reaches the end opposite to the position of the cooling water supply port 15, it goes around the groove-shaped cooling water flow path 14 on one side half on the side of 20 a, and then the groove-shaped cooling water flow path 14 on one side half on the side of 20 a It is a member for partitioning between the cooling water supply port 15 and the discharge port 16 so as to flow toward the discharge port 16 and finally to be discharged from the cooling water discharge port 16. Further, in FIG. 4, the cooling water that has flowed to the end through the groove-shaped cooling water flow path 14 on one side half of the 20 a side is discharged from the cooling water discharge port 16 formed on the side of the cylinder block 11. Although the cylinder block has been described, for example, the cooling water that has flowed from one end to the other end of the groove-like cooling water passage 14 on one half of the 20a side is discharged from the side of the cylinder block. Instead, there is a cylinder block configured to flow into a cooling water passage formed in the cylinder head.

As shown in FIGS. 5 to 7, the cylinder bore wall heat insulator 36a is attached to the inside of the base member 34a and one half 341a of the base member 34a, and is divided into four parts. It has an expanded rubber 351a and a second expanded rubber 352a that is attached to the inside of the other half 342a of the base member 34a and is divided into four parts. In the heat insulator 36a on the cylinder bore wall, the first expansion rubber 351a and the second expansion rubber 352a are attached to the inner surface of the base member 34a with, for example, an adhesive or an adhesive tape.

The cylinder bore wall heat retainer 36a is a heat retainer for keeping the bore wall 21 of the cylinder block 11 shown in FIG. A bore wall 23a1 of the cylinder bore 12a1, a bore wall 23b1 of the cylinder bore 12b1, a bore wall 23b2 of the cylinder bore 12b2, and a bore wall 23a2 of the cylinder bore 12a2 and the bore walls of each of the four cylinder bores are formed on the bore wall 21a on one half of the cylinder block 11. is there. The cylinder bore wall heat insulator 36a is provided with a first expansion rubber 351a for keeping warm the bore walls of the four cylinder bores of the bore wall 21a on one half of the cylinder block 11. Further, the bore wall 21b on one half of the cylinder block 11 includes a bore wall 23a1 of the cylinder bore 12a1, a bore wall 23b3 of the cylinder bore 12b1, a bore wall 23b4 of the cylinder bore 12b2, and a bore wall 23a2 of the cylinder bore 12a2, and the bores of the four cylinder bores. There is a wall. And in the cylinder bore wall heat insulator 36a, a second expansion rubber 352a is provided in order to keep the bore walls of the four cylinder bores of the bore wall 21b on one half of the cylinder block 11 warm.

The base member 34a, when viewed from above, has a circular arc shape and is formed in a shape that surrounds the wall surface 17 of the cylinder bore of the groove-shaped cooling water flow path. The shape of the base member 34a is the groove-shaped cooling water flow path 14 It is a shape along. The base member 34a is a member to which the first expanded rubber 351a and the second expanded rubber 352a are fixed inside. The base member 34a is a synthetic resin molded body.

In the heat insulator 36a on the cylinder bore wall, the contact surface 26 of the first expansion rubber 351a faces the wall surface 17 side on the cylinder bore side of the grooved coolant channel on the inner surface of one half 341a of the base member 34a. For example, the first expansion rubber 351a is adhered by an adhesive, an adhesive tape, or the like. Further, in the heat insulator 36a on the cylinder bore wall, the contact surface 26 of the second expansion rubber 352a faces the wall surface 17 side on the cylinder bore side of the grooved coolant passage on the inner surface of the other half 342a of the base member 34a. Thus, for example, the second expansion rubber 352a is adhered by an adhesive, an adhesive tape, or the like.

The first expanded rubber 351a and the second expanded rubber 352a are formed of expanded rubber. As this expanded rubber, before expansion, the base foam material is compressed and restrained by a thermoplastic substance, and is heated to release the restraint by the thermoplastic resin, that is, the state before being compressed, that is, A heat-sensitive expansion rubber that is a rubber material that expands to an open state; a rubber-added material with a water-absorbing substance, and a rubber material that retains its expanded shape by absorbing water and swelling. Water swellable rubber is mentioned. Therefore, the first expansion rubber 351a and the second expansion rubber 352a are members for keeping the bore walls of the respective cylinder bores, and the heat retaining tool 36a for the cylinder bore walls is installed in the grooved cooling water flow path 14 of the cylinder block 11. After that, in the case of heat-expandable rubber, it is heated, and in the case of water-swellable rubber, it expands by contact with cooling water. When the first expansion rubber 351a and the second expansion rubber 352a expand, the contact surface 26 comes into contact with the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path of the groove-shaped cooling water flow path 14, and the groove shape The wall surface of the wall surface 17 on the cylinder bore side of the cooling water passage 14 is covered.

When the first expansion rubber 351a and the second expansion rubber 352a start to expand in the grooved cooling water flow path 14, the first expansion rubber 351a and the second expansion rubber 352a have contact surfaces 26 of the grooved cooling water flow path. Since it expands until it comes into contact with the wall surface 17 on the cylinder bore side and further attempts to expand, the force that the expanded rubber further expands on the wall surface 17 on the cylinder bore side and the base member 34a of the grooved coolant channel, That is, the elastic force of the expanded rubber after expansion is applied. Then, due to the elastic force of the expanded rubber after expansion, the contact surfaces 26 of the first expanded rubber 351a and the second expanded rubber 352a are pressed against the wall surface 17 on the cylinder bore side of the grooved cooling water flow path, and the first expanded rubber. One side half 341a of the base member 34a is pushed toward the opposite wall 18 of the cylinder bore wall 17 by 351a, and the other side half 342a of the base member 34a is pushed by the cylinder bore wall 17 by the second expansion rubber 352a. Is pushed toward the opposite wall 18. With such an action, the cylinder bore wall heat insulator 36a is held in the grooved coolant flow path 14. Further, since the first expansion rubber 351a and the second expansion rubber 352a are in close contact with the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path and cover the wall surface 17 of the cylinder bore of the groove-shaped cooling water flow path, the groove-shaped cooling water flow path The wall surface 17 of the cylinder bore is kept warm by the first expanded rubber 351a and the second expanded rubber 352a.

The heat insulator 36a on the cylinder bore wall is installed, for example, in the grooved coolant flow path 14 of the cylinder block 11 shown in FIG. As shown in FIG. 8, the cylinder bore wall heat insulator 36a is inserted into the grooved cooling water channel 14 of the cylinder block 11, and the cylinder bore wall heat insulator 36a is inserted into the grooved cooling water channel 14 as shown in FIG. 14 is installed. When the heat insulator 36a on the cylinder bore wall is inserted into the groove-shaped cooling water flow path 14, the first expansion rubber 351a and the second expansion rubber 352a are not yet expanded. When inserted into the cooling water channel 14, the contact surfaces 26 of the first expansion rubber 351a and the second expansion rubber 352a do not contact the wall surface 17 on the cylinder bore side of the grooved cooling water channel.

Then, after the cylinder bore wall heat insulator 36a is installed in the grooved cooling water channel 14, before the expansion, as shown in FIG. 10A, the contact surface 26 of the cylinder bore wall heat retaining member and the grooved cooling water channel. There is a gap 30 between the wall surfaces 17 on the cylinder bore side of the first expansion rubber 351a and the first expansion rubber 351a when the expansion rubber is heated or contacted with cooling water as shown in FIG. The second expansion rubber 352a expands until it comes into contact with the wall surface 17 on the cylinder bore side of the grooved cooling water flow path.

A cylinder bore wall heat retaining device of the present invention is a cylinder bore wall heat retaining device that is installed in a groove-like cooling water flow path of a cylinder block of an internal combustion engine having a cylinder bore and heats the bore walls of all the cylinder bores.
When viewed from above, a base member having a shape surrounding the wall surface on the cylinder bore side of the groove-like cooling water flow channel over the entire circumference;
It is fixed inside the base member, and expands in the grooved cooling water flow path to contact the wall surface of the grooved cooling water flow path on the cylinder bore side to keep the bore wall of the cylinder bore warm. A first inflating rubber that pushes one half of the first toward the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-shaped cooling water flow path;
It is fixed inside the base member, and expands in the grooved cooling water flow path to contact the wall surface of the grooved cooling water flow path on the cylinder bore side to keep the bore wall of the cylinder bore warm. A second expansion rubber that pushes the other half on the opposite side of the wall surface on the cylinder bore side of the groove-shaped cooling water flow path,
Consisting of,
A cylinder bore wall heat insulator characterized by

The cylinder bore wall heat insulator of the present invention is installed in the grooved coolant flow path of the cylinder block of the internal combustion engine. The cylinder block in which the heat insulating device for the cylinder bore wall of the present invention is installed is an open deck type cylinder block in which two or more cylinder bores are formed in series. When the cylinder block is an open deck type cylinder block in which two cylinder bores are arranged in series, the cylinder block has a cylinder bore composed of two end bores. When the cylinder block is an open deck type cylinder block in which three or more cylinder bores are arranged in series, the cylinder block has a cylinder bore composed of two end bores and one or more intermediate bores. ing. In the present invention, among the cylinder bores arranged in series, the bores at both ends are called end bores, and the bores sandwiched between the other cylinder bores are called intermediate bores.

The position where the heat insulator for the cylinder bore wall of the present invention is installed is a grooved coolant flow path. In many internal combustion engines, the position corresponding to the middle and lower part of the groove-shaped cooling water flow path of the cylinder bore is a position where the speed of the piston increases, so it is preferable to keep the temperature of the middle and lower part of the groove-shaped cooling water flow path. In FIG. 2, a position 10 near the middle between the uppermost part 9 and the lowermost part 8 of the groove-like cooling water flow path 14 is indicated by a dotted line, but the groove-like cooling water flow path 14 on the lower side from the position 10 near the middle is shown. This portion is referred to as the middle lower portion of the grooved cooling water flow path. The middle and lower part of the grooved cooling water flow path does not mean the part below the middle part between the uppermost part and the lowermost part of the grooved cooling water flow path. It means the part. Further, depending on the structure of the internal combustion engine, the position where the piston speed increases may be a position where it hits the lower part of the grooved coolant flow path of the cylinder bore. In that case, the lower part of the grooved coolant flow path is kept warm. It is preferable. Therefore, the position from the lowermost part of the grooved cooling water flow path to the heat retention by the cylinder bore wall heat-insulating device of the present invention, that is, the position of the upper end of the rubber member in the vertical direction of the grooved cooling water flow path Is appropriately selected.

The heat insulating device for the cylinder bore wall according to the present invention is fixed to the base member, the first inflated rubber (before expansion) fixed to the inner side of one half of the base member, and the other half of the base member. Second expanded rubber (before expansion). The cylinder bore wall heat insulator of the present invention is a heat insulator for keeping the wall surface on the cylinder bore side of the grooved coolant flow channel over the entire circumference when viewed in the circumferential direction. That is, the cylinder bore wall heat insulator of the present invention is a heat insulator for keeping the entire bore wall of the cylinder bore when viewed in the circumferential direction.

The base member according to the heat insulator for the cylinder bore wall of the present invention is made of synthetic resin or metal. That is, the base member is made of synthetic resin or metal. The synthetic resin that forms the base member is not particularly limited as long as it is a synthetic resin that is normally used for a heat insulator or a water jacket spacer on a cylinder bore wall that is installed in a grooved cooling water flow path of a cylinder block of an internal combustion engine. It is selected appropriately. The metal forming the base member is usually a metal used for a heat insulator for a cylinder bore wall or a water jacket spacer installed in a grooved cooling water flow path of a cylinder block of an internal combustion engine, such as stainless steel (SUS), aluminum alloy. Etc. The shape of the base member is a shape along the shape of the groove-shaped cooling water flow path, and is a shape in which arcs are continuously connected around the circuit when viewed from above.

The base member is composed of one member, for example, the entire circumference is made by synthetic resin integral molding, or a plurality of metal plate molded bodies are integrated by caulking, welding, etc. It may be a shape, or it is a combination of divided bodies in which the entire circumference is divided into two or more parts, and two or more of them at the joint formed in each divided body These divided bodies may be combined and combined. When the base member is a combination of two or more divided bodies, the two or more divided bodies may be combined to form the entire circumference before being installed in the grooved cooling water flow path, or It is good also as a shape for all the circumferences combining a split body in the case of installation to a groove-shaped cooling water flow path.

The base member is composed of one half of the base member and the other half of the base member. The first expanded rubber is fixed to one half of the base member, and the second expanded rubber is fixed to the other half of the base member. In the present invention, the half on one side of the base member refers to a half base member on one side when the base member is vertically divided into two in the direction in which the cylinder bores are arranged. For example, in FIG. 6, the upper half of the base member in FIG. 6 is one half of the base member, and the lower half of the base member is the other half of the base member.

In the cylinder bore wall heat insulating device of the present invention, the first expansion rubber (before expansion) can cover a portion of the cylinder bore wall on one half side of the base member that is to be heated and then cover a portion of the cylinder bore wall to be kept warm. It is provided at a position where it can. Similarly, in the cylinder bore wall heat insulating device of the present invention, the second expanded rubber (before expansion) is the portion of the cylinder bore wall on the other half side of the base member that is to be expanded and then the portion of the cylinder bore wall that is to be kept warm. It is provided at a position where it can be covered. The installation position, shape, and installation range of the first expansion rubber and the second expansion rubber are appropriately selected depending on the number of the bore walls of each cylinder bore to be kept warm and the heat keeping site. For example, as in the embodiment shown in FIG. 5, one first expanded rubber and second expanded rubber may be provided for each bore wall of each cylinder bore. Moreover, the 1st expansion rubber and the 2nd expansion rubber of the shape connected over the bore wall of two or more cylinder bores may be provided. Moreover, like the example shown in FIG.12 and FIG.13, the 1st expansion rubber and the 2nd expansion rubber are connected and may be united. The cylinder bore wall heat insulator 36b shown in FIG. 12 and FIG. 13 has a base member 34b having a shape surrounding the cylinder bore side wall surface of the grooved cooling water flow channel over the entire circumference when viewed from above. The first expansion rubber 351b and the second expansion rubber 352b are connected to each other. In the present invention, each bore portion of the base member refers to one arc-shaped portion constituting the base member, and refers to a portion facing the bore wall of one cylinder bore.

The first expanded rubber (before expansion) and the second expanded rubber (before expansion) are not particularly limited as long as they are expandable rubbers, and examples thereof include heat-expandable rubber and water-swellable rubber.

When the expansion rubber is a heat-sensitive expansion rubber, the first expansion rubber (before expansion) and the second expansion rubber (before expansion) are formed of a heat-sensitive expansion rubber in a compressed state. Thermally-expandable rubber (compressed state) is a composite that is compressed by impregnating a base foam material with a thermoplastic material having a melting point lower than that of the base foam material. At room temperature, it is compressed by a cured product of at least the surface of the thermoplastic material. It is a material whose state is maintained and whose cured product of the thermoplastic material is softened by heating to release the compressed state. Examples of the heat-sensitive expansion rubber include heat-sensitive expansion rubber described in JP-A-2004-143262.

Examples of the base foam material relating to the heat-expandable rubber include various polymer materials such as rubber, elastomer, thermoplastic resin, and thermosetting resin. Specifically, natural rubber, chloropropylene rubber, styrene butadiene rubber, nitrile Examples include butadiene rubber, ethylene propylene diene terpolymer, various synthetic rubbers such as silicone rubber, fluoro rubber, and acrylic rubber, various elastomers such as soft urethane, various thermosetting resins such as hard urethane, phenol resin, and melamine resin. It is done.

As the thermoplastic material related to the heat-expandable rubber, those having any of glass transition point, melting point or softening temperature of less than 120 ° C are preferable. Thermoplastic materials related to heat-expandable rubber include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylate ester, styrene butadiene copolymer, chlorinated polyethylene, polyvinylidene fluoride, ethylene acetate Vinyl copolymer, ethylene vinyl acetate vinyl chloride acrylic ester copolymer, ethylene vinyl acetate acrylic ester copolymer, ethylene vinyl acetate vinyl chloride copolymer, nylon, acrylonitrile butadiene copolymer, polyacrylonitrile, polyvinyl chloride , Polychloroprene, polybutadiene, thermoplastic polyimide, polyacetal, polyphenylene sulfide, polycarbonate, thermoplastic resins such as thermoplastic polyurethane, low melting glass frit, starch Solder, wax, cast iron, stainless steel, and various thermoplastic materials metal material such as aluminum or the like.

When the expanded rubber is a water-swellable rubber, the first expanded rubber (before expansion) and the second expanded rubber (before expansion) are formed of the water-swellable rubber before expansion.

Water-swellable rubber is a material in which a water-absorbing substance is added to rubber, and is a rubber material that retains its expanded shape by absorbing water and swelling. Examples of the water-swellable rubber include a rubber material in which a water-absorbing substance such as a cross-linked product of neutralized polyacrylic acid, a cross-linked product of starch acrylic acid graft copolymer, a cross-linked carboxymethyl cellulose salt, and polyvinyl alcohol is added to the rubber. Can be mentioned. Examples of the water-swellable rubber include water-swellable rubbers containing ketiminated polyamide resins, glycidyl etherified products, water-absorbing resins and rubbers described in JP-A-9-208752. When the material of the expanded rubber is a water-swellable rubber, the heat insulator of the cylinder bore wall of the present invention is installed in the groove-like cooling water flow path, the cooling water is flowed, and the water-swellable rubber absorbs the water, Swellable rubber expands.

In the heat insulator for the cylinder bore wall according to the present invention, the first expanded rubber and the second expanded rubber are fixed to the inner surface of the base member. As a method of fixing the first expanded rubber and the second expanded rubber to the inner surface of the base member, a method of sticking with an adhesive, an adhesive tape, an adhesive, or the like, a separate resin or SUS is used for fixing. Examples thereof include a method, a method in which a part of an expanded rubber or a base member is melted and bonded. Further, when the base member is made of metal, a bent portion for sandwiching the expanded rubber is formed in the metal base member, and the expanded rubber is fixed between the main body portion of the base member and the fixing bent portion. A method is mentioned. In the present invention, the inner side of the base member refers to the side that becomes the cylinder bore wall side when installed in the grooved cooling water flow path, and the outer side of the base member refers to the inner side of the grooved cooling water flow path. When it is installed, it refers to the side of the cylinder bore wall that faces the wall.

The method for adhering the first expanded rubber and the second expanded rubber to the base member is not particularly limited and is appropriately selected. For example, the first expanded rubber and the second expanded rubber are bonded using an adhesive, an adhesive tape, an adhesive, or the like. A method of sticking the two-expansion rubber to the base member is mentioned. In the heat insulator for the cylinder bore wall according to the present invention, after the expansion rubber is expanded, the first expansion rubber and the second expansion rubber are pressed against the base member by the elastic force of the expansion rubber after expansion. Even if the adhesive strength of the adhesive or the like is not strong, the first expanded rubber and the second expanded rubber are not easily displaced from the position where they are adhered to the base member with the adhesive, adhesive tape, adhesive, or the like.

In particular, as will be described later, when a concave portion for preventing displacement of the first expanded rubber or the second expanded rubber is formed on the inner surface of the base member, the concave portion for preventing positional displacement causes the first Since the first expanded rubber and the second expanded rubber are prevented from being displaced from the position where they are fixed to the base member with an adhesive, an adhesive tape, an adhesive, etc., the adhesive force of the adhesive, the adhesive tape, the adhesive, etc. Even if the adhesive force is such that the first expanded rubber and the second expanded rubber are not peeled off from the surface of the base member until the cylinder bore wall heat insulator of the present invention is inserted into the grooved cooling water flow path. Good.

In the warmer of the cylinder bore wall of the present invention, the first expansion relative to the compression ratio of the first expansion rubber or the second expansion rubber before expansion, that is, the thickness (t ₀ ) of the first expansion rubber or the second expansion rubber in the open state. The ratio of the thickness (t _i ) before expansion of the rubber or the second expanded rubber ((t _i / t ₀ ) × 100) is preferably 12 to 80%, particularly preferably 19 to 46%. In the present invention, the open state thickness (t ₀ ) of the first expanded rubber or the second expanded rubber is, as shown in FIG. 11B, in the case of the thermally expanded rubber, the thermally expanded rubber is thermoplastic. After expansion of the heat-expandable rubber when unconstrained by the substance and expanded in an open state without any restrictions, in the case of water-swellable rubber, the water-swellable rubber is subject to any restrictions The thickness after expansion of the water-swellable rubber when it is in contact with water and absorbs and expands in an open state, that is, the first expanded rubber 351a (or the second expanded rubber 352a) in the open state It is thickness. FIG. 11 (B) is a diagram illustrating a state after the first expanded rubber 351a illustrated in FIG. 11 (A) has expanded in an open state in which expansion is not limited at all.

When the first expansion rubber expands, the contact surface comes into contact with the wall surface on the cylinder bore side of the groove-like cooling water flow path on the side where one half of the base member is disposed, so that the half of the base member is on one side. The wall surface on the cylinder bore side of the groove-like cooling water flow path on the side where the is disposed is covered. Further, when the second expanded rubber expands, the contact surface comes into contact with the wall surface on the cylinder bore side of the grooved cooling water flow channel on the side where the other half of the other side of the base member is disposed, and the other side of the base member The wall surface on the cylinder bore side of the grooved coolant flow path on the side where the half on one side is disposed is covered.

When the first expansion rubber and the second expansion rubber start to expand in the grooved cooling water flow path, the contact surfaces of the first expansion rubber and the second expansion rubber come into contact with the wall surface on the cylinder bore side of the grooved cooling water flow path. Since the expansion rubber continues to expand to the cylinder bore wall surface and the base member of the grooved cooling water flow path, the expansion rubber expands on the expansion rubber after expansion. The elastic force of is applied. Then, due to the elastic force of the expanded rubber after expansion, the contact surfaces of the first expanded rubber and the second expanded rubber are pressed against the wall surface on the cylinder bore side of the grooved cooling water flow path, so that the first expanded rubber and the second expanded rubber Since the rubber adheres closely to the wall surface of the grooved cooling water flow path on the cylinder bore side and covers the wall surface of the cylinder bore of the grooved cooling water flow path, the wall surface of the cylinder bore of the grooved cooling water flow path has the first expansion rubber and the second expansion Insulated with rubber. Further, due to the elastic force of the first expanded rubber after expansion, one half of the base member is opposed to the wall on the cylinder bore side wall of the grooved cooling water flow channel on the side where the one half of the base member is disposed. The other half of the base member is placed on the cylinder bore side of the groove-like cooling water flow channel on the side where the other half of the base member is disposed by the elastic force of the expanded second expanded rubber. It is pushed toward the opposite wall. Since one half of the base member is connected to the other half of the base member, the one half of the base member is directed toward the wall surface on the cylinder bore side of the grooved coolant flow path by the other half of the base member. The other half of the base member is attracted toward the cylinder bore side wall surface of the grooved coolant flow path by the one half of the base member. By such an action, the heat insulating device for the cylinder bore wall of the present invention is held in the grooved cooling water flow path. That is, the cylinder bore wall heat insulating device according to the present invention has a first expansion rubber and a second expansion rubber which are expanded inside the base member, so that they are not displaced in the grooved cooling water flow path and are kept at predetermined positions. Retained.

In the cylinder bore wall heat insulating device of the present invention, the first expansion rubber and the second expansion rubber, which are members for maintaining the temperature of the cylinder bore wall, also function to hold the cylinder bore wall heat insulating device of the present invention in a predetermined position. Therefore, the number of members can be reduced. Therefore, the cylinder bore wall heat insulator of the present invention can be easily produced.

Further, in the heat insulator for the cylinder bore wall according to the present invention, the base member is made of synthetic resin, and the first expanded rubber and the second expanded rubber are made of synthetic resin, such as an adhesive, an adhesive tape, and an adhesive. The base member is bonded to the base body member of the present invention, in which the base body member is made of metal, and a bent portion for sandwiching the expanded rubber is formed in the metal base member, and the expanded rubber is used as the base material. Compared to a mode in which the member is sandwiched and fixed between the main body portion and the bent portion, the member is easily manufactured.

Here, when the first expansion rubber and the second expansion rubber are fixed to the base member with an adhesive, an adhesive tape, an adhesive, welding such as integral molding, or a metal fixing bracket, the fixing force is applied to the base member. The first expansion rubber and the second expansion rubber are weaker than the fixing force in the case of fixing by bending a metal fixing bending portion. In addition, by expanding the first expanded rubber and the second expanded rubber in the grooved cooling water flow path, the first expanded rubber and the second expanded rubber generated by the expanded force of the expanded rubber press the cylinder bore wall and the base member. Is weaker than the biasing force of a metal elastic member such as a metal leaf spring. However, among the heat insulators of the cylinder bore wall of the present invention, the base member is made of synthetic resin, and the first expanded rubber and the second expanded rubber are welded with an adhesive, an adhesive tape, an adhesive, integral molding, etc. When the base member is formed of a synthetic resin that is lighter than the metal material in a form that is fixed to the base member made of synthetic resin with a metal fixing bracket or the like, the first expansion rubber is formed in the groove-shaped cooling water flow path. In addition, the elastic force of the expanded rubber after the second expanded rubber expands is added to the fixing force of the adhesive, adhesive tape, adhesive, integral molding, etc., metal fixing bracket, etc. The wall heat insulator can be made difficult to shift from the installation position in the grooved cooling water flow path, and the first expanded rubber and the second expanded rubber can be made difficult to shift from the attachment position to the base member.

The cylinder bore wall heat retaining device of the present invention has a recess for preventing displacement of the cylinder bore wall heat retaining member formed on the inner surface of the base member, and the first expansion rubber or the second expansion rubber prevents displacement. It is preferable that the concave portion for covering is covered with the first expansion rubber and the second expansion rubber from the position fixed to the base member in the grooved cooling water flow path. The first expansion rubber expanded in the state where the first expansion rubber or the second expansion rubber is expanded in the groove-shaped cooling water flow path in the recess for preventing displacement of the first expansion rubber or the second expansion rubber. Alternatively, since the second expanded rubber bites into the first expanded rubber or the second expanded rubber, the first expanded rubber or the second expanded rubber is less likely to be displaced from the fixing position of the base member than the concave portion for preventing the displacement of the first expanded rubber or the second expanded rubber. The shape of the recess for preventing misalignment is not particularly limited, and examples thereof include a circular recess, a rectangular recess, and a circular or rectangular through hole. The formation position and number of the recesses for preventing misalignment are appropriately selected.

The cylinder bore wall heat insulator of the present invention can have a cooling water flow partition member on one end side as in the embodiment shown in FIG. Further, the cylinder bore wall heat insulating device of the present invention is provided with a member for preventing the entire heat insulating device from shifting upward in the support portion, for example, on the upper side of both sides of the support portion, and the upper end is a cylinder head or a cylinder. A cylinder head abutting member that abuts the head gasket can be provided. In addition, the cylinder bore wall heat insulator of the present invention may have other members for adjusting the flow of the cooling water.

The internal combustion engine of the present invention has a cylinder block in which a grooved cooling water flow path is formed,
The cylinder bore wall heat insulator of the present invention is installed in the grooved cooling water flow path,
An internal combustion engine characterized by the above.

The cylinder block according to the internal combustion engine of the present invention is the same as the cylinder block according to the heat insulator for the cylinder bore wall according to the present invention.

The internal combustion engine of the present invention includes a cylinder head, a camshaft, a valve, a piston, a connecting rod, and a crankshaft in addition to the cylinder block and the cylinder bore wall heat retaining device of the present invention installed in the grooved coolant flow path. .

The automobile of the present invention is an automobile having the internal combustion engine of the present invention.

According to the present invention, a cylinder bore wall heat insulator that has high adhesion to the wall surface on the cylinder bore side of the grooved cooling water flow path of the cylinder block and is less likely to be displaced in the grooved cooling water flow path by a simple manufacturing process. Since it can be manufactured, it is possible to provide a heat insulator for the cylinder bore wall that has high adhesion to the wall surface on the cylinder bore side of the grooved cooling water flow path of the cylinder block and is less likely to be displaced in the grooved cooling water flow path.

8 Lowermost part 9 Uppermost part 10 Middle position 11 Cylinder block 12 Bore 12a1, 12a2 End bore 12b1, 12b2 Intermediate bore 13 Cylinder bore wall 14 Grooved cooling water flow path 15 Cooling water supply port 16 Cooling water discharge port 17 Grooved cooling water flow Wall surfaces 17a, 17b on the cylinder bore side of the passage 18 Wall surface 18 on the half side of the channel Wall surfaces 21a, 21b on the opposite side of the wall surface on the cylinder bore side of the grooved coolant flow channel Bore walls 23a1, 23a2, 23b1, 23b2 26 Expansive rubber contact surface 30

Crevice

34a,

34b Base member

36a, 36b Cylinder bore wall heat insulator 38 Cooling water flow partition member 191 Bore portion 192 Bore wall of each cylinder bore on the cylinder bore side wall surface of the grooved coolant passage Field 341a, one of the one half 342a of 341b the base member, half the other side of the

342b base member

351a, 351b

first expansion rubber

352a, 352b second expansion rubber O cylinder bore center axis _{t 0} thickness of the open state of expansion rubber t _i Thickness of expanded rubber before expansion

Claims

A cylinder bore wall heat insulator installed in a grooved coolant flow path of a cylinder block of an internal combustion engine having a cylinder bore for keeping the bore walls of all cylinder bores,
When viewed from above, a base member having a shape surrounding the wall surface on the cylinder bore side of the groove-like cooling water flow channel over the entire circumference;
It is fixed inside the base member, and expands in the grooved cooling water flow path to contact the wall surface of the grooved cooling water flow path on the cylinder bore side to keep the bore wall of the cylinder bore warm. A first inflating rubber that pushes one half of the first toward the wall surface on the opposite side of the wall surface on the cylinder bore side of the groove-shaped cooling water flow path;
It is fixed inside the base member, and expands in the grooved cooling water flow path to contact the wall surface of the grooved cooling water flow path on the cylinder bore side to keep the bore wall of the cylinder bore warm. A second expansion rubber that pushes the other half on the opposite side of the wall surface on the cylinder bore side of the groove-shaped cooling water flow path,
Consisting of,
Cylinder bore wall thermal insulation.
The expanded rubber is a heat-sensitive expanded rubber comprising a base foam material and a thermoplastic material, and the base foam material is silicon rubber, fluorine rubber, natural rubber, butadiene rubber, ethylene propylene diene rubber or nitrile butadiene rubber. The cylinder bore wall heat insulator according to claim 1, wherein the thermoplastic substance is a resin or a metal material.
3. The cylinder bore wall heat insulator according to claim 1, wherein the base member is made of synthetic resin.
The ratio ((t i / t 0 ) × 100) of the thickness (t i ) before expansion of the expanded rubber to the thickness (t 0 ) of the expanded rubber in an open state is 12 to 80%, The cylinder bore wall heat insulating device according to any one of claims 1 to 3.