JP2021127694A - Heat insulation tool of cylinder bore wall, internal combustion engine, and automobile - Google Patents

Abstract

To provide a heat insulation tool of a cylinder bore wall with reduced difference of a thermal deformation amount between upper and lower sides of the cylinder bore wall.SOLUTION: A heat insulation tool 36a of a cylinder bore wall has: an expansion member 31a made of an expansion material, having a space 25 serving as a cooling water holding part after expansion at a center, and contacting a cylinder bore side wall of a groove-like cooling water flow path after expansion; a back face side pressing part 32 provided with an elastic member 33 for press-energizing the expansion member 31a, and pressing the entire expansion member to the cylinder bore side wall of the groove-like cooling water flow path from the back face side; a front side patch plate 30 provided on a contact face side of the expansion member 31a, having a first opening 301 inside, and sandwiching an outer edge side of the expansion member 31a by the back face side pressing part 32; and one or more fixing parts for fixing the expansion part 31a, the back face side pressing part 32, and the front side patch plate 30 as an integral heat insulation part.SELECTED DRAWING: Figure 5

Description

The present invention relates to a cylinder bore wall heat insulating device in which a heat insulating portion is arranged in contact with a wall surface on the groove-shaped cooling water flow path side of the cylinder bore wall of the cylinder block of an internal combustion engine, and an internal combustion engine and an automobile provided with them.

In an internal combustion engine, a fuel explosion occurs at the top dead center of the piston in the bore, and the piston is pushed down by the explosion. Therefore, the temperature is high on the upper side of the cylinder bore wall and low 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 expands less.

As a result, the frictional resistance of the piston with the cylinder bore wall increases, which is a factor that reduces fuel consumption. Therefore, it is required to reduce the difference in the amount of 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 groove-shaped cooling water flow path, the flow of the cooling water in the groove-shaped cooling water flow path is adjusted, and the cylinder bore wall by the cooling water is used. Attempts have been made to control the cooling efficiency of the upper side and the cooling efficiency of the lower side. For example, in Patent Document 1, a flow that divides the groove-shaped cooling heat medium flow path into a plurality of flow paths by being arranged in the groove-shaped cooling heat medium flow path formed in the cylinder block of the internal combustion engine. It is a road partition member and is formed at a height less than the depth of the groove-shaped cooling heat medium flow path, and the inside of the groove-shaped cooling heat medium flow path includes a bore-side flow path and an anti-bore-side flow path. A flow path dividing member serving as a wall portion to be divided into the above, and a groove-shaped cooling heat medium formed from the flow path dividing member toward the opening of the groove-shaped cooling heat medium flow path and having a tip edge portion thereof. Since it is made of a flexible material so as to extend beyond one inner surface of the flow path, the tip edge portion is affected by its own bending restoring force after the insertion into the groove-shaped cooling heat medium flow path is completed. A flexible lip member that separates the bore-side flow path and the anti-bore-side flow path by contacting the inner surface at an intermediate position in the depth direction of the groove-shaped cooling heat medium flow path. A heat medium flow path partition member for cooling an internal combustion engine is disclosed.

JP-A-2008-31939 (Claims)

However, according to the heat medium flow path partition member for cooling the internal combustion engine of Reference 1, the wall temperature of the cylinder bore wall can be made uniform to some extent, so that the difference in the amount of thermal deformation between the upper side and the lower side of the cylinder bore wall is small. However, in recent years, it has been further required to reduce the difference in the amount of thermal deformation between the upper side and the lower side of the cylinder bore wall.

Therefore, an object of the present invention is to provide a heat insulating device for a cylinder bore wall in which the difference in the amount of thermal deformation between the upper side and the lower side of the cylinder bore wall is reduced.

The above problem is solved by the following invention. That is, the present invention (1) is a cylinder bore wall heat insulating tool which is installed in a groove-shaped cooling water flow path of a cylinder block of an internal combustion engine having a cylinder bore and for keeping a part of the bore walls of all cylinder bores warm. And
It is made of an inflatable material, has a space portion in the center that serves as a cooling water holding portion after expansion, an outer edge is located outside the first opening of the front side backing plate, and an inner edge is the first opening of the front side backing plate. An expansion member having a shape located inside one opening and contacting the wall surface on the cylinder bore side of the groove-shaped cooling water flow path after expansion.
An elastic member provided on the back surface side of the expansion member and urging the expansion member so as to press the expansion member is attached, and the entire expansion member is directed from the back surface side toward the wall surface of the groove-shaped cooling water flow path on the cylinder bore side. And the back side pressing part for pressing
The front side backing plate provided on the contact surface side of the expansion member, having the first opening inside, and sandwiching the outer edge side of the expansion member with the back side pressing member.
One or more fixing portions for fixing the expansion member, the back side pressing portion, and the front side backing plate as an integral heat retaining portion.
To have
Provided is a heat insulating device for a cylinder bore wall, which is characterized by the above.

Further, the present invention (2) is characterized in that the expansion member is composed of two or more divided bodies, and the shape of the outer edge and the shape of the inner edge of the expansion member are rectangular (1). It provides a heat insulator for a cylinder bore wall.

Further, in the present invention (3), the expansion member is provided on the front side backing plate at a position separated from the one or more fixing portions, protrudes toward the expansion member, and the expansion member is placed between the expansion member and the rear side pressing member. Provided is a warming device for a cylinder bore wall having one or more beads to be sandwiched.

Further, in the present invention (4), the expansion member is provided on the back surface pressing member at a position separated from the one or more fixing portions, projects toward the expansion member, and the expansion member is placed between the expansion member and the front support plate. Provided is a warming device for a cylinder bore wall having one or more beads to be sandwiched.

Further, the present invention (5) provides an internal combustion engine having a heat insulating device for a cylinder bore wall according to any one of (1) to (4).

Further, the present invention (6) provides an automobile having the internal combustion engine according to (5).

According to the present invention, it is possible to provide a heat insulating device for a cylinder bore wall in which the difference in the amount of thermal deformation between the upper side and the lower side of the cylinder bore wall is reduced.

It is a schematic plan view which shows the form example of the cylinder block in which the heat insulator of the cylinder bore wall of this invention is installed. It is a schematic cross-sectional view along the position of the F2-F2 line of FIG. It is a perspective view of the cylinder block shown in FIG. It is a schematic plan view which shows the form example of the cylinder block in which the heat insulator of the cylinder bore wall of this invention is installed. It is a schematic perspective view which shows the state of making the form example of the heat insulation part which concerns on the heat insulation tool of the cylinder bore wall of this invention. It is a schematic diagram which shows the heat insulation part which concerns on the heat insulation tool of the cylinder bore wall of this invention, and is the figure which was seen from the inside. It is sectional drawing which shows the heat insulator shown in FIG. 2 in more detail. It is a schematic diagram which shows the manufacturing procedure of the elastic member attachment member. It is a schematic front view which shows the form example of the heat insulation part which concerns on the heat insulation tool of the cylinder bore wall of this invention. It is a schematic perspective view which shows the back side pressing member to which an elastic member is attached. It is a schematic perspective view which shows the state of making the form example of the heat insulation part which concerns on the heat insulation tool of the cylinder bore wall of this invention. It is a schematic diagram which shows the morphological example of the expansion member. It is a schematic diagram which shows the morphological example of the expansion member. It is a schematic diagram which shows the morphological example of the expansion member. It is a schematic diagram which shows the morphological example of the expansion member. It is a schematic diagram which shows the morphological example of the expansion member. It is a schematic diagram which shows the morphological example of the expansion member. It is an enlarged view of the vicinity of the engaging portion of the expansion member in FIG. It is a schematic diagram which shows the morphological example of the expansion member. It is a schematic diagram which shows the manufacturing method of the divided body of an expansion member. It is a schematic diagram which shows the manufacturing method of the divided body of an expansion member. It is a schematic diagram which shows the manufacturing method of the divided body of an expansion member. It is a schematic front view which shows the 1st Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. FIG. 3 is a front view showing a state in which the front side backing plate is removed from the heat insulating portion shown in FIG. 23. It is a schematic front view which shows the 2nd Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. FIG. 5 is a front view showing a state in which the front side backing plate is removed from the heat insulating portion shown in FIG. 25. It is a schematic front view which shows the 3rd Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. It is a front view which shows the state which the front side backing plate was removed from the heat insulation part shown in FIG. It is sectional drawing which follows the position of the F29-F29 line of FIG. It is sectional drawing which shows the part A of FIG. 29 enlarged. It is a schematic front view which shows the 4th Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. FIG. 3 is a front view showing a state in which the front side backing plate is removed from the heat insulating portion shown in FIG. 31. It is a schematic front view which shows the 5th Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. FIG. 3 is a front view showing a state in which the front side backing plate is removed from the heat insulating portion shown in FIG. 33. It is a schematic front view which shows the 6th Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. FIG. 3 is a front view showing a state in which the front side backing plate is removed from the heat insulating portion shown in FIG. 35. It is a schematic front view which shows the 7th Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. FIG. 3 is a front view showing a state in which the front side backing plate and the expansion member are removed from the heat insulating portion shown in FIG. 37. It is sectional drawing which follows the position of the F39-F39 line of FIG. It is sectional drawing which shows the part B of FIG. 39 enlarged. It is a schematic cross-sectional view which shows the 8th Embodiment of the convex part of the heat insulating tool of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. It is a schematic front view which shows the 9th Embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention. It is a schematic front view which shows the tenth embodiment of the convex part of the heat insulating device of the cylinder bore wall of the 1st embodiment and the 2nd aspect of this invention.

The heat insulating device for the cylinder bore wall of the first aspect of the present invention and the internal combustion engine of the present invention will be described with reference to FIGS. 1 to 9. 1 to 4 show an example of a cylinder block in which the heat insulating device for the cylinder bore wall of the present invention is installed, and FIGS. 1 and 4 show a cylinder in which the heat insulating device for the cylinder bore wall of the present invention is installed. It is a schematic plan view showing a block, FIG. 2 is a cross-sectional view taken along the line F2-F2 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 a mode example of the heat insulating device for the cylinder bore wall of the present invention. FIG. 6 is a schematic view showing a heat insulating device for a cylinder bore wall of the present invention, and is a view seen from the inside. FIG. 7 is a cross-sectional view showing the details of the heat insulating device of FIG.

As shown in FIGS. 1 to 3, the bore 12 for the piston to move up and down and the cooling water to flow through the open deck type cylinder block 11 of the internal combustion engine for vehicle mounting in which the heat insulating device for the cylinder bore wall is installed. Groove-shaped cooling water flow path 14 is formed. The wall that separates the bore 12 and the groove-shaped cooling water flow path 14 is the cylinder bore wall 13. Further, the cylinder block 11 is formed with a cooling water supply port 15 for supplying cooling water to the groove-shaped cooling water flow path 11 and a cooling water discharge port 16 for discharging the cooling water from the groove-shaped cooling water flow path 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 one end bore 12a1 and the other end bore 12a2. The wall between the end bore 12a1 and the intermediate bore 12b1, the wall between the intermediate bore 12b1 and the intermediate bore 12b2, and the wall between the intermediate bore 12b2 and the end bore 12a2 (inter-bore wall 191) is a portion sandwiched between the two bores. Therefore, since heat is transferred from the two cylinder bores, the wall temperature is higher than that of the other walls. Therefore, on the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path 14, the temperature is highest in the vicinity of the bore wall 191. Therefore, among the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path 14, the bore of each cylinder bore The temperature at and near the wall boundary 192 is highest.

Further, in the present invention, among the wall surfaces of the groove-shaped cooling water flow path 14, the wall surface on the cylinder bore 13 side is described as the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path, and among the wall surfaces of the groove-shaped cooling water flow path 14. The wall surface on the side opposite to the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path is referred to as a wall surface 18.

Further, in the present invention, the bore wall of each cylinder bore refers to each bore wall portion corresponding to each cylinder bore, and in FIG. 4, the range indicated by the double-headed arrow 22a1 is the bore wall 23a1 of the cylinder bore 12a1. The range indicated by the double-headed arrow 22b1 is the bore wall 23b1 of the cylinder bore 12b1, the range indicated by the double-headed arrow 22b2 is the bore wall 23b2 of the cylinder bore 12b2, and the range indicated by the double-headed arrow 22a2 is the bore wall 23a2 of the cylinder bore 12a2. The range indicated by the double-headed arrow 22b3 is the bore wall 23b3 of the cylinder bore 12b1, and the range indicated by the double-headed 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 are each of the cylinder bores. It is a bore wall.

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, a bore wall 23a2 of the cylinder bore 12a2, and a bore wall of each of the four cylinder bores. included. On the other half of the bore wall 21a of the cylinder block 11, 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 and the bore wall 23a2 of the cylinder bore 12a2, and the bores of each of the four cylinder bores. There is a wall.

In the present embodiment, the heat insulating tool 36a is provided at a position corresponding to the bore wall 23a2 and at a position facing the cooling water supply port 15. In the present embodiment, the heat insulating device 36a is installed at this position, but the installation position of the heat insulating device 36a is not limited to this. That is, the heat insulating tool 36a may be provided at a position corresponding to the bore wall 23a1, the bore wall 23b3, or the bore wall 23b4 in the bore wall 21b on one side half where the cooling water supply port 15 is provided. Further, the heat insulating tool 36a is provided at a position corresponding to the bore wall 23a1, the bore wall 23b1, the bore wall 23b2, or the bore wall 23a2, among the other half bore walls 21a on which the cooling water supply port 15 is not provided. You may be.

As shown in FIG. 5, the heat insulating tool 36a includes an elastic member attachment member 33 to which a metal leaf spring 39 is attached and has an arcuate cross section, a back surface pressing plate 32 formed in an arcuate shape, an expansion member 31a, and the expansion member 31a. It has a front side backing plate 30 formed in an arc shape, and a fixing portion for fixing these as an integral heat insulating tool 36a. The fixing portion is formed at the bent portion 331a formed at the upper end of the elastic member attached member 33, the bent portion 331b formed at the lower end of the elastic member attached member 33, and the right end of the elastic member attached member 33. It has a bent portion 332a and a bent portion 332b formed at the left end of the elastic member attachment member 33.

As shown in FIG. 6, the bent portions 331a, 331b, 332a, and 332b are bent toward the front side backing plate 30, and between these and the elastic member attachment member 33, the back side pressing plate 32 and the expansion member 31a And sandwich the front side backing plate 30. In this way, the heat insulating device 36a is integrally manufactured. In the embodiment shown in FIG. 6, the elastic member attachment member 33 and the back side pressing plate 32 are combined to form the back side pressing portion.

The heat insulating tool 36a on the cylinder bore wall is provided with an expansion member 31a and a contact surface 26 thereof on the wall surface on the cylinder bore side. The contact surface 26 of the expansion member 31a can come into contact with the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path 14. Further, on the back side of the heat insulating portion 36a of the cylinder bore wall, the metal leaf spring 39 projects toward the side opposite to the expansion member 31a. Then, when the expansion member 31a expands in the groove-shaped cooling water flow path, the protruding tip 27 of the metal leaf spring 39 comes into contact with the wall surface 18 on the side opposite to the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path 14. ..

The expansion member 31a is composed of a frame-shaped elastic body having an opening in the center. The expansion member 31a is a member that expands in the groove-shaped cooling water flow path, directly contacts the bore wall 22 of each cylinder bore, and surrounds the heat retaining portion of the bore wall 22. Then, the expansion member 31a expands in the groove-shaped cooling water flow path and comes into contact with the bore wall 22 of the cylinder bore, so that the expansion member 31a, the bore wall 22 of the cylinder bore, and the back side pressing plate 32 hold the cooling water. Form a part. During the operation of the internal combustion engine, the cooling water held in the cooling water holding portion is heated to a temperature similar to that of the expansion member 31a, so that the bore wall 22 of each cylinder bore is kept warm. The expansion member 31a has a space portion 25 in the central portion for forming a cooling water holding portion by expanding in the groove-shaped cooling water flow path. Further, the back side pressing plate 32 has an arcuate cross section, and the back side of the expanding member 31a (opposite to the contact surface 26 side) so that the entire expanding member 31a can be pressed from the back side of the expanding member 31a. It has a shape along the side surface).

Further, the elastic member attachment member 33 has an arcuate cross section, has a shape along the back surface side (the surface opposite to the heat-sensitive expansion rubber 31) of the back surface side pressing plate 32, and is a metal leaf spring 39 which is an elastic member. Has. The metal leaf spring 39 is a vertically long rectangular metal plate, and one end in the longitudinal direction is connected to the elastic member attachment member 33. The metal leaf spring 39 is bent with respect to the elastic member attachment member 33 at the other end side 28 so that the tip 27 is separated from the metal leaf spring attachment member 33. The elastic member attachment member 33 may have a frame portion 33A having a frame shape. The elastic member attachment member may be formed so as to form an arc shape by connecting a plurality of plates. Even if the elastic member attachment member has one or more leg portions 100 projecting downward from the frame portion and one or more stopper portions 101 projecting upward from the frame portion to prevent lifting. good. The leg portion 100 may be bent in an “L” shape, for example, and may abut on the bottom of the groove-shaped cooling water flow path 14 to support the entire heat insulating tool 11. The stopper portion 101 may be bent in an inverted “L” shape, for example, and can prevent the heat insulating tool 11 from coming up from the groove-shaped cooling water flow path 14 when it comes into contact with the cylinder head. In FIG. 5, the leg portion 100 and the stopper portion 101 are shown one by one, but the number of the leg portion 100 and the stopper portion 101 may be two or more.

The front side backing plate 30 has an arcuate cross section, has a frame shape, and has a rectangular opening 301 inside. Then, the bent portions 332a and 332b formed at the upper end of the elastic member attached member 33, the bent portions 331a and 331b formed at the lower end of the elastic member attached member 33, and the right end of the elastic member attached member 33 are formed. The bent portion 332a and the bent portion 332b formed at the left end of the elastic member attachment member 33 are bent (caulked) toward the front side backing plate 30 side. As a result, the back side pressing member 32, the expansion member 31 and the front side backing plate 30 are sandwiched between the bent portions 332a, 332b, 331b, 332a, 332b and the elastic member attachment member 33, and these are fixed. There is. In the expansion member 31a, the surface opposite to the back surface side pressing member 32 side is the contact surface 26 in contact with the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path.

As shown in FIG. 6, when the heat insulating tool 36a is viewed from the inside, the inner edge of the expanding member 31a, that is, the contour of the space portion 25 of the expanding member 31a is located inside the opening 301 of the front backing plate 30. There is. Further, as shown in FIG. 7, the inner edge portion of the expansion member 31a is located outside the opening 301 of the front backing plate 30. As shown in FIG. 7, the inner edge portion of the expansion material 31a is not sandwiched between the front backing plate 30 and the back side pressing member 32, and protrudes from the opening 301 of the front backing plate 30 toward the wall surface 17 on the cylinder bore side. There is. The outer edge portion of the expansion member 31a is sandwiched and fixed by the front backing plate 30 and the back side pressing plate 32.

As shown in FIG. 6, the front side backing plate 30 has a portion whose outer end is sandwiched by the bent portion and a portion which is not sandwiched by the bent portion. That is, in the heat insulating tool 36a, the outer end is sandwiched between the bent portions 332a and 332b on the upper portion of the front side contact plate 30, and the outer end is the bent portion 331a on the lower portion of the front side contact plate 30. , The portion sandwiched between the front side backing plates 30 and the right side portion of the front side backing plate 30, the outer end is sandwiched between the bent portions 332a, and the outer end is the bent portion 332b on the left side portion of the front side backing plate 30. There is a part sandwiched between them. Further, in the heat insulating tool 36a, the outer end is not sandwiched between the bent portions 332a and 332b on the upper portion of the front side backing plate 30, and the outer end is bent on the lower portion 308b of the front side backing plate 30. There is a portion that is not sandwiched between 331a and 331b.

A convex portion is formed in a portion of the front side backing plate 30 whose outer end is not sandwiched between the bent portions. That is, in the portion of the front side backing plate 30 where the outer end of the upper side is not sandwiched between the bent portions 332a and 332b, a convex portion (bead) 302a extending in the longitudinal direction of the upper side of the front side backing plate 30 is provided. It is formed. Further, in the portion where the outer end of the lower side portion of the front side contact plate 30 is not sandwiched between the bent portions 331a and 331b, a convex portion (bead) 302b extending in the longitudinal direction of the lower side portion of the front side contact plate 30 is provided. It is formed.

As shown in FIG. 7, the convex portions 302a and 302b formed on the front backing plate 30 are recessed into the expansion member 31a. As a result, the expansion member 31a is strongly fixed to the heat retaining portion, so that misalignment is less likely to occur. When viewed from the inside, the position where the convex portion 302a is formed is inside the outer edge of the expansion material 31a.

The heat insulating tool 36a on the cylinder bore wall is installed, for example, in the groove-shaped cooling water flow path 14 of the cylinder block 11 shown in FIG.

When the automobile and the internal combustion engine are operated after the heat insulating tool 36a on the cylinder bore wall is installed in the groove-shaped cooling water flow path 14 of the cylinder block 11, the expansion material 31a expands. Then, as shown in FIG. 7, the inner edge portion of the expansion material 31a expands toward the wall surface 17 on the cylinder bore side through the opening 301 formed in the inner portion of the front side backing plate 30, and the contact surface 26 Contact the wall surface 17 on the cylinder bore side. At this time, the repulsive force of the metal leaf spring 39 pushes the elastic member attachment member 33 toward the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path. As a result, the back side pressing member 32 pushed by the elastic member attachment member 33 presses the expansion member 31a against the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path. That is, due to the expansion of the expansion member 31a and the repulsive force of the metal leaf spring 39, the expansion material 31a is further strongly pressed against the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path. In this way, the inner edge side 311 of the expansion material 31a of the heat insulating tool 36a of the cylinder bore wall comes into contact with the bore wall surface of the cylinder bore of the groove-shaped cooling water flow path.

At this time, the inner edge side 311 of the expansion material 31a expands and comes into contact with the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path, so that the inner edge side 311 of the expansion member 31a, the wall surface 17, and the back surface side pressing member 32 A cooling water holding portion 25 surrounded by and is formed. Cooling water is held in the cooling water holding portion 25 when the automobile and the internal combustion engine are being operated. Since the cooling water held in the cooling water holding portion 25 stays in the cooling water holding portion 25, the temperature gradually rises to the same temperature as the inner edge side of the expansion member 31a. As a result, the cooling water held in the cooling water holding portion 25 exhibits heat retention equal to or higher than that of the expansion material 31a (because the cooling water has a larger heat capacity than the expansion material 31a).

Therefore, the cooling water held by the cooling water holding portion 25 and the inner edge side 311 of the expansion member 31a function as a heat retaining portion. The cooling water holding unit 25 may maintain a completely sealed state when the internal combustion engine is operated, thereby restricting the movement of the cooling water inside and outside the cooling water holding unit 25. With this structure, it is possible to reliably keep the heat in the lower part and the middle part of the bore wall of the cylinder bore to be kept warm. The cooling water holding unit 25 may allow the cooling water to be replaced from a part of the expansion member 31a without being completely sealed when the internal combustion engine is operated. With this structure, when the internal combustion engine is being operated, the cooling water held in the cooling water holding portion 25 is replaced little by little inside and outside the cooling water holding portion 25. This prevents the temperature of the bore wall of the cylinder bore to be kept warm from rising too high by replacing the cooling water little by little when the internal combustion engine is operated for a long time or at a high rotation speed. Can be done.

The heat insulating device of the first aspect of the present invention is installed in a groove-shaped cooling water flow path of a cylinder block of an internal combustion engine having a cylinder bore, and is a cylinder bore wall for keeping a part of the bore walls of all cylinder bores warm. It is a heat insulator and
It is made of an inflatable material, has a space in the center that serves as a cooling water holding portion after expansion, the outer edge is located outside the opening of the front side backing plate, and the inner edge is the first opening of the front side backing plate. An expansion member that has a shape located more inside and that comes into contact with the wall surface on the cylinder bore side of the groove-shaped cooling water flow path after expansion.
An elastic member provided on the back surface side of the expansion member and urging the expansion member so as to press the expansion member is attached, and the entire expansion member is directed from the back surface side toward the wall surface of the groove-shaped cooling water flow path on the cylinder bore side. And the back side pressing part for pressing
The front side backing plate provided on the contact surface side of the expansion member, having a front opening inside, and sandwiching the outer edge side of the expansion member with the back side pressing member.
One or more fixing portions for fixing the expansion member, the back side pressing portion, and the front side backing plate as an integral heat retaining portion.
To have
It is a heat insulating device for a cylinder bore wall.

The heat insulating device for the cylinder bore wall of the first aspect of the present invention has an arcuate cross section, and has a back surface pressing portion to which an elastic member is attached and expands in a groove-shaped cooling water flow path, so that the contact surface is grooved. An expansion member that contacts the wall surface on the cylinder bore side of the cooling water flow path and a front side backing plate having an arcuate cross section are sequentially overlapped, and a bent portion and a back side that are formed at the upper end of the back side pressing portion. The bent portion formed at the lower end of the pressing portion, the bent portion formed at the right end of the back side pressing portion, and the bent portion formed at the left end of the back side pressing portion are bent toward the front side backing plate side. The expansion member and the front side backing plate are sandwiched between the back side pressing portion and the bending portion to fix them. In the present invention, the upper end, the lower end, the right end and the left end of the heat insulating portion refer to the upper end, the lower end, the right end and the left end when viewed from the inside, in other words, from the contact surface side of the expansion member. ..

The expansion member according to the heat insulating device of the cylinder bore wall of the first aspect of the present invention expands in the groove-shaped cooling water flow path, and the contact surface directly contacts the bore wall of each cylinder bore, so that the bore wall and the back side of the cylinder bore It is a member for forming the cooling water holding portion at the heat retaining portion of the bore wall by surrounding the cooling water holding portion with the pressing portion. In the expansion material, the surface opposite to the back surface pressing member side is the contact surface in contact with the cylinder bore wall of the groove-shaped cooling water flow path.

The expansion member is made of an expansion material (elastic body). Examples of the expansion material include heat-sensitive expansion rubber, water-swellable rubber, and cellulosic sponge.

The heat-sensitive expansion rubber is rubber that expands by being heated in the groove-shaped cooling water flow path. The heat-sensitive expansion rubber is a composite obtained by impregnating a base foam material with a thermoplastic substance having a melting point lower than that of the base foam material and compressing the rubber. Moreover, it is a material in which the cured product of the thermoplastic substance is softened by heating and the compressed state is released. Examples of the heat-sensitive expansion rubber include the heat-sensitive expansion rubber described in JP-A-2004-143262. When the material of the rubber member is heat-sensitive expansion rubber, the heat insulating device of the cylinder bore wall of the present invention is installed in the groove-shaped cooling water flow path, and heat is applied to the heat-sensitive expansion rubber, so that the heat-sensitive expansion rubber expands and is predetermined. It expands and deforms into the shape of.

Examples of the base foam material related to the heat-sensitive expansion rubber include various polymer materials such as rubber, elastomer, thermoplastic resin, and thermosetting resin. Specific examples thereof include natural rubber, chloropropylene rubber, styrene butadiene rubber, and nitrile. Examples include various synthetic rubbers such as butadiene rubber, ethylene propylene diene ternary copolymer, silicone rubber, fluororubber, and acrylic rubber, various elastomers such as soft urethane, and various thermosetting resins such as hard urethane, phenol resin, and melamine resin. Be done.

The thermoplastic substance for the heat-sensitive expansion rubber preferably has a glass transition point, a melting point, or a softening temperature of less than 120 ° C. Examples of the thermoplastic substance related to the heat-sensitive expansion rubber include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, vinyl acetate, polyacrylic acid ester, styrene-butadiene copolymer, chlorinated polyethylene, polyvinylidene fluoride, and ethylene-acetic acid. Vinyl copolymer, ethylene vinyl acetate vinyl acetate acrylic acid ester copolymer, ethylene vinyl acetate acrylic acid ester copolymer, ethylene vinyl acetate vinyl acetate copolymer, nylon, acrylonitrile butadiene copolymer, polyacrylonitrile, thermoplastic , Polychloroprene, polybutadiene, thermoplastic polyimide, polyacetal, polyphenylene sulfide, polycarbonate, thermoplastic resins such as thermoplastic polyurethane, and various thermoplastic compounds such as low melting point glass frit, starch, solder, and wax.

As the water-swellable rubber, the water-swellable rubber is a material to which a water-absorbing substance is added to the rubber, and is a rubber material having a shape-retaining property that absorbs water and swells to maintain the expanded shape. Examples of the water-swellable rubber include a rubber material in which a water-absorbent substance such as a crosslinked product of a polyacrylic acid neutralized product, a crosslinked product of a starch acrylic acid graft copolymer, a crosslinked carboxymethyl cellulose salt, and polyvinyl alcohol is added to the rubber. Can be mentioned. Examples of the water-swellable rubber include a water-swellable rubber containing a ketimated polyamide resin, a glycidyl etherified product, a water-absorbent resin, and a rubber described in JP-A-9-208752. When the material of the rubber member is water-swellable rubber, the heat insulator of the cylinder bore wall of the present invention is installed in the groove-shaped cooling water flow path to allow the cooling water to flow, and the water-swellable rubber absorbs water to cause water. The swellable rubber expands and expands and deforms into a predetermined shape.

The cellulosic sponge has a shape-retaining property that absorbs water, swells, and retains the swollen shape.

The expansion member has an arcuate cross section. When viewed from the front side, the expansion member has a space portion in the central portion that serves as a cooling water holding portion after expansion. The outer edge of the expansion member is located outside the opening of the front side backing plate, and the inner edge of the expansion material, that is, the contour of the space portion is located inside the opening of the front side backing plate. Therefore, since the outer edge side of the expansion member is sandwiched between the front side contact plate and the back side pressing member, the expansion member is fixed to the heat insulating portion, and the inner edge side of the expansion member is the opening of the front side contact plate. Since it protrudes from the outside, it expands in the groove-shaped cooling water flow path, and the contact surface contacts the wall surface of the cylinder bore.

Then, in the groove-shaped cooling water flow path, the inner edge side of the expansion material expands and comes into contact with the wall surface of the groove-shaped cooling water flow path on the cylinder bore side, so that the inner edge side of the expansion material, the bore wall of the cylinder bore, and the back surface are contacted. A cooling water holding portion surrounded by the side pressing member is formed. When the internal combustion engine is in operation, the cooling water holding portion holds the cooling water. Since the cooling water held in the cooling water holding portion stays in the cooling water holding portion, the temperature gradually rises to the same temperature as the inner edge side of the expansion material. As a result, the cooling water held in the cooling water holding portion exhibits heat retention equal to or higher than that of the expanding material, so that the cooling water held in the cooling water holding portion and the inner edge side of the expanding material retain heat. Functions as a part.

The back surface pressing portion of the heat insulating device of the cylinder bore wall of the first aspect of the present invention has an arcuate cross section, and the back surface of the expanding member can be pressed so that the entire expanding member can be pressed from the back surface side of the expanding member. It has a shape along the side (the surface opposite to the contact surface side) and covers the entire back surface side or almost the entire back surface side of the expanding material. The back surface pressing portion is also a material that closes the back surface side of the cooling water holding portion. Therefore, the entire space of the expansion member is covered from the back side.

Bent portions are formed at the upper end, the lower end, the right end, and the left end of the back pressing portion. The bent portion of the back pressing portion is formed between the bent portion and the back pressing portion by being bent toward the front pressing plate side in a state where the back pressing member, the expanding member, and the front pressing plate are stacked in this order. , A part for sandwiching the expansion member and the front side backing plate.

The back side pressing portion includes a member (for example, the back side pressing plate 32) that pushes the expansion member from the back side toward the wall surface on the cylinder bore side of the groove-shaped cooling water flow path, and a bent portion, as in the embodiment shown in FIG. It may be configured in combination with a member (for example, an elastic member attachment member 33) on which the expansion member is formed, or as in the morphological examples shown in FIGS. 10 and 11, the expansion member is groove-shaped cooled from the back surface side. It may be composed of one member having both a portion to be pressed toward the wall surface on the cylinder bore side of the water flow path and a bent portion. The back side pressing portion 47 shown in FIGS. 10 and 11 has a back side pressing portion 321 and is bent so as to sandwich the expansion member and the front side backing plate between the bent portion and the back pressing member. Bent portions 331c, 331d, 332e and 332f, and a bent portion 37a for fixing the heat insulating portion to the base member are formed, and an elastic member 39 is attached.

The material of the back side pressing portion may be any material as long as it can be deformed so that the expansion member can be pressed toward the wall surface on the cylinder bore side of the groove-shaped cooling water flow path when pushed from the back side by the elastic member. Although it is selected, a metal plate such as stainless steel or an aluminum alloy is preferable. The thickness of the back-side pressing portion may be appropriately deformed so as to be able to be deformed so that the elastic member can be pressed toward the wall surface on the cylinder bore side of the groove-shaped cooling water flow path when pressed from the back side by the elastic member. Be selected.

An elastic member is attached to the back pressing portion. As for the elastic member, the heat insulating device for the cylinder bore wall of the first aspect of the present invention is installed in the groove-shaped cooling water flow path, and is elastically deformed by the expansion of the expanding material, and the wall surface on the cylinder bore side of the groove-shaped cooling water flow path. It is a member for urging by elastic force so that the back side pressing member presses the heat-sensitive expansion rubber toward.

One or more elastic members are attached in the arc direction when the heat insulating portion is viewed from above. It is preferable that two or more elastic members are attached in the arc direction, because the force with which the expanding material is pressed toward the wall surface on the cylinder bore side of the groove-shaped cooling water flow path is less likely to vary, and heat retention is preferable. It is more preferable that the heat insulating portion is provided at one location in the center or near the center in the arc direction, one location near one end of the heat insulating portion, and one location near the other end, for a total of three locations. Further, in order to improve the adhesion of the expansion material to the wall surface on the cylinder bore side of the groove-shaped cooling water flow path, elastic members may be attached to four or more places in the arc direction of the heat insulating portion.

The form of the elastic member is not particularly limited, and examples thereof include a plate-shaped elastic member, a coil-shaped elastic member, a laminated leaf spring, a torsion spring, and an elastic rubber. The material of the elastic member is not particularly limited, but stainless steel (SUS), an aluminum alloy, or the like is preferable in terms of good LLC resistance and high strength. As the elastic member, a metal elastic member such as a metal leaf spring, a coil spring, a laminated leaf spring, and a torsion spring is preferable.

Of the bent portions formed on the back side pressing portion, the bent portions formed on the right end and the left end cover all of the right end or the left end of the back side pressing member in the vertical direction as shown in FIG. It may be formed over the entire surface, or it may be formed in a part of the right end or the left end of the back surface side pressing portion in the vertical direction as in the embodiment shown in FIG. Further, when the bent portion is formed on a part of the right end or the left end of the back side pressing portion, a convex portion is formed on the portion of the front side backing plate whose outer end is not sandwiched by the bent portion. It is preferable that the expansion member is less likely to be misaligned. In the heat insulating tool 36a of the embodiment shown in FIG. 9, of the right side portion of the front side contact plate 30a, the portion whose outer end is not sandwiched by the bent portion 332c is in the longitudinal direction of the right side portion of the front side contact plate 30a. An extending convex portion 302c is formed, and of the left side portion of the front side contact plate 30a, the portion whose outer end is not sandwiched by the bent portion 332d is in the longitudinal direction of the left side portion of the front side contact plate 30a. An extending convex portion 302d is formed.

Since the bent portions at the right end and the left end of the back side pressing portion are bent in a straight line, they are formed over the entire right end or the left end of the back side pressing portion in the vertical direction as shown in the embodiment shown in FIG. Can be bent normally. The bent portions at the right end and the left end of the back side pressing portion are formed over the entire vertical direction of the right end or the left end of the elastic member attachment member, and are formed in the vertical direction on the right side or the left side of the expansion material and the front side backing plate. It is preferable to sandwich all of the above in that the expanding member is less likely to be misaligned.

Since the upper and lower ends of the heat insulating device are arcuate when viewed from above, if the width of the bent portions formed at the upper and lower ends of the back pressing portion is too long, the bent portion cannot be bent normally. Also, the expansion material and the front side backing plate are not fixed normally. Therefore, the width of the bent portion formed at the upper end and the lower end of the back side pressing portion is appropriately selected within a range in which normal bending is possible and the expansion material and the front side backing plate can be normally fixed. .. The number of bent portions formed at the upper end and the lower end of the back surface side pressing portion is two or more in the arc direction of the heat insulating portion when the heat insulating portion is viewed from above.

As a method of manufacturing the back side pressing portion, for example, as shown in FIG. 8, a metal plate 43 is prepared, and the metal plate 43 is punched out at the position of the dotted line in FIG. 8 (A). As shown in (B), the metal leaf spring 39, the bent portion 332a, 332b, 331b, 332a, 332b and the bent portion 37 are formed to produce a punched product 45 of the metal plate. Next, the entire punched-out 45 of the metal plate is formed into an arc shape, and the metal leaf spring 39 is bent toward the back side to produce the elastic member attachment member 33. Next, the metal plate to be the back side pressing plate is formed into an arc shape to produce the back side pressing plate 32. Then, by combining the elastic member attachment member 33 and the back side pressing plate 32, the back side pressing member is formed.

The front side backing plate according to the heat insulating device of the cylinder bore wall of the first aspect of the present invention has an arc shape, and when viewed from the front side, a substantially rectangular opening is formed inside. Then, in the heat retaining portion, the expansion member is fixed by sandwiching the outer edge side of the expansion member between the back side pressing portion and the front side backing plate.

The front side backing plate has a portion in which the outer end is sandwiched by the bent portion and a portion in which the outer end is not sandwiched in the bent portion. In the heat insulating portion, at least the upper portion and the lower portion of the front side backing plate have a portion whose outer end is not sandwiched between the bent portions. Further, in the heat insulating portion, the right side portion and the left side portion of the front side backing plate may or may not have a portion whose outer end is not sandwiched between the bent portions. In other words, in the heat insulating portion, the right side portion and the left side portion of the front side backing plate may be entirely sandwiched between the bent portions in the vertical direction of the outer end, or may be partially sandwiched.

In the portion of the front side backing plate whose outer end is not sandwiched between the bent portions, a convex portion that is convex toward the back side pressing member may be formed, or the convex portion may not be formed. However, the fact that a convex portion that is convex toward the back side pressing member is formed means that the expanding member is strongly fixed to the heat insulating portion by the convex portion digging into the expanding member, and it is difficult for the expansion member to be displaced. It is preferable in that. When a convex portion is formed in a portion of the upper portion of the front side backing plate whose outer end is not sandwiched between the bent portions, a convex portion extending in the longitudinal direction of the upper portion of the front side backing plate is formed, and also. When a convex portion is formed in a portion of the lower portion of the front side backing plate whose outer end is not sandwiched between the bent portions, a convex portion extending in the longitudinal direction of the lower portion of the front side backing plate is formed. Further, when a convex portion is formed on the right side portion of the front side backing plate whose outer end is not sandwiched between the bent portions, a convex portion extending in the longitudinal direction of the right side portion of the front side backing plate is formed. Further, when a convex portion is formed on a portion of the left side portion of the front side backing plate whose outer end is not sandwiched between the bent portions, a convex portion extending in the longitudinal direction of the left side portion of the front side backing plate is formed. ..

The heat insulating device for the cylinder bore wall of the second aspect of the present invention will be described with reference to FIGS. 10 and 11.

As shown in FIG. 11, the heat insulating tool 36a includes a back side pressing member 33b and an expansion member 31a formed in an arc shape, a front side backing plate 30 formed in an arc shape, and a fixing portion for fixing these. And have. The heat insulating tool 36a is formed by stacking the back side pressing member 33b, the expanding member 31a, and the front side backing plate 30 in this order. The fixing portions are formed on the bent portions 332a and 332b formed at the upper end of the back side pressing member 33b, the bent portions 331a and 331b formed at the lower end of the back side pressing member 33b, and the right end of the back side pressing member 33b. It has a bent portion 332a formed and a bent portion 332b formed at the left end of the back surface side pressing member 33b. These included in the fixing portion are bent toward the front side backing plate 30 side. The fixing portion sandwiches the expansion member 31a and the front side backing plate 30 between the bent portion 332a, 332b, 331b, 332a, 332b and the back side pressing member 33b.

In the heat insulating tool 36b of the cylinder bore wall, the contact surface 26 of the expansion member 31a faces the wall surface on the cylinder bore side, and the contact surface 26 of the expansion member 31a can contact the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path 14. , The heat insulating device 36a is fixed.

As shown in FIG. 11, the heat insulating tool 36a fixed to the heat insulating portion 36b of the cylinder bore wall includes a front side backing plate 30, an expansion member 31a, a back side pressing member (rear side pressing portion) 33b, and these. It has a fixing portion for fixing. The fixing portion is formed at the bent portion 331a formed at the upper end of the back side pressing member 33b, the bent portion 331b formed at the lower end of the back side pressing member 33b, and the right end of the back side pressing member 33b. It has a bent portion 332a and a bent portion 332b formed at the left end of the back surface side pressing member 33b.

The expansion member 31a is a member that expands in the groove-shaped cooling water flow path, directly contacts the bore wall 22 of each cylinder bore, and surrounds the heat retaining portion of the bore wall 22. Then, when the expansion member 31a expands in the groove-shaped cooling water flow path and comes into contact with the bore wall 22 of the cylinder bore, the cooling water holding portion surrounded by the expansion member 31a, the bore wall 22 of the cylinder bore, and the back surface pressing member 33b. Is formed. The cooling water held in the cooling water holding portion can keep the bore wall 22 of each cylinder bore warm. The expansion member 31a has a space portion 25 for forming a cooling water holding portion in the central portion.

Further, the back side pressing member 33b has a shape along the back side (the surface opposite to the contact surface 26 side) of the expansion member 31a so that the entire expansion member 31a can be pressed from the back side of the expansion member 31a. Is. Further, the back surface side pressing member 33b has an arcuate cross section and has a shape along the back surface side of the expansion material 31a. As shown in FIG. 10, the back surface side pressing member 33b has a metal leaf spring 39 which is an elastic member. The metal leaf spring 39 is a vertically long rectangular metal plate, and one end in the longitudinal direction is connected to the back surface side pressing member 33b. The metal leaf spring 39 is provided obliquely with respect to the back side pressing member 33b so that the tip 27 is separated from the back side pressing member 33b.

As shown in FIG. 11, the front side backing plate 30 has an arcuate cross section, and when viewed from the inside, the outer edge is assembled and a rectangular opening 301 is formed.

When the heat insulating tool 36a is viewed from the inside, the inner edge of the expansion member 31a, that is, the contour of the space portion 25 of the expansion member 31a is located inside the opening 301 of the front backing plate 30. Further, the outer edge of the expansion member 31a is located outside the opening 301 of the front backing plate 30. Therefore, the outer edge side of the expansion member 31a is sandwiched and fixed by the front backing plate 30 and the back side pressing plate 32. Further, the inner edge side of the expansion material 31a is not sandwiched between the front backing plate 30 and the back side pressing member 33b, and protrudes from the opening 301 of the front backing plate 30.

The front side backing plate 30 has a portion whose outer end is sandwiched by the bent portion and a portion which is not sandwiched by the bent portion. That is, in the heat insulating tool 36a, the outer end is sandwiched between the bent portions 332a and 332b on the upper portion of the front side contact plate 30, and the outer end is the bent portion 331a on the lower portion of the front side contact plate 30. , The portion sandwiched between the front side backing plates 30 and the right side portion of the front side backing plate 30, the outer end is sandwiched between the bent portions 332a, and the outer end is the bent portion 332b on the left side portion of the front side backing plate 30. There is a part sandwiched between them. Further, in the heat insulating tool 36a, the outer end is not sandwiched between the bent portions 332a and 332b on the upper portion of the front side backing plate 30, and the outer end is bent on the lower portion 308b of the front side backing plate 30. There is a portion that is not sandwiched between 331a and 331b.

A convex portion is formed in a portion of the front side backing plate 30 whose outer end is not sandwiched between the bent portions. That is, in the portion of the front side backing plate 30 where the outer end of the upper side is not sandwiched between the bent portions 332a and 332b, a convex portion 302a extending in the longitudinal direction of the upper side of the front side backing plate 30 is formed. There is. Further, a convex portion 302b extending in the longitudinal direction of the lower portion of the front side backing plate 30 is formed in a portion where the outer end of the lower side of the front side backing plate 30 is not sandwiched between the bent portions 331a and 331b. There is.

The convex portion 302a formed on the front backing plate 30 is recessed into the expansion member 31a. As a result, the expansion member 31a is strongly fixed to the heat retaining portion, so that misalignment is less likely to occur. When viewed from the inside, the position where the convex portion 302a is formed is inside the outer edge of the expansion material 31a.

When the internal combustion engine is operated after the heat insulating tool 36b on the cylinder bore wall is installed in the groove-shaped cooling water flow path 14 of the cylinder block 11, the expansion material 31a expands. Then, the inner edge side of the expansion material 31a, which is not sandwiched between the front backing plate 30 and the back side pressing member 33b, passes through the opening 301 formed in the inner portion of the front side backing plate 30 and reaches the wall surface 17 on the cylinder bore side. It expands toward it, and the contact surface 26 comes into contact with the wall surface 17 on the cylinder bore side. At this time, the repulsive force of the metal leaf spring 39 pushes the back surface side pressing member 33b toward the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path. As a result, the expansion member 31a is further pressed against the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path. In this way, the inner edge side of the expansion material 31a of the heat insulating tool 36a of the heat insulating tool 36b of the cylinder bore wall comes into contact with the bore wall surface of the cylinder bore of the groove-shaped cooling water flow path 14.

At this time, the inner edge side of the expansion material 31a expands and comes into contact with the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path, so that the inner edge side of the expansion member 31a, the wall surface 17, and the back surface side pressing member 33b are formed. An enclosed cooling water holding portion is formed. When the internal combustion engine is in operation, the cooling water holding portion holds the cooling water. Since the cooling water held in the cooling water holding portion stays in the cooling water holding portion, the temperature gradually rises to the same temperature as the inner edge side of the expansion material 31a. As a result, the cooling water held in the cooling water holding portion 25 exhibits heat retention equal to or higher than that of the expansion material 31a (because the cooling water has a larger heat capacity than the expansion material 31a).

The cooling water held in the cooling water holding portion 25 and the inner edge side of the expansion material 31a function as a heat retaining portion. The cooling water holding unit 25 may maintain a completely sealed state when the internal combustion engine is operated, thereby restricting the movement of the cooling water inside and outside the cooling water holding unit 25. With this structure, it is possible to reliably keep the heat in the lower part and the middle part of the bore wall of the cylinder bore to be kept warm. The cooling water holding unit 25 may allow the cooling water to be replaced from a part of the expansion member 31a without being completely sealed when the internal combustion engine is operated. With this structure, when the internal combustion engine is being operated, the cooling water held in the cooling water holding portion 25 is replaced little by little inside and outside the cooling water holding portion 25. This prevents the temperature of the bore wall of the cylinder bore to be kept warm from rising too high by replacing the cooling water little by little when the internal combustion engine is operated for a long time or at a high rotation speed. Can be done.

Next, the form of the expansion member used for the cylinder bore wall heat insulating device of the first aspect of the present invention and the cylinder bore wall heat insulating device of the second aspect of the present invention will be described.

In the expansion member 31a shown in FIG. 12, the shape of the outer edge is rectangular, and the shape of the inner edge, that is, the outline of the space portion is rectangular. The expansion member 31a is composed of one member. That is, the expansion member 31a is not composed of a plurality of divided bodies.

In the expansion member 31b shown in FIG. 13, the shape of the outer edge is such that a part of the upper side and the lower side of the rectangle projects outward. The shape of the inner edge of the expansion member 31b is rectangular. The expansion member 31b is composed of one member. In the embodiment shown in FIG. 13, the overhanging portion is provided on the upper side and the lower side of the rectangle, but the shape is not limited to this, and the shape may have an overhanging portion on the right side and / or the left side of the rectangle. .. Further, in the embodiment shown in FIG. 27, two overhangs are provided on one side of the rectangle, but the present invention is not limited to this, and when the overhangs are provided, one or more overhangs can be provided on one side. ..

That is, the shape of the outer edge of the expansion member according to the heat insulating device for the cylinder bore wall of the first aspect of the present invention and the heat insulating device for the cylinder bore wall of the second aspect of the present invention is such that the outer edge is outside the opening of the front side backing plate. It may or may not be rectangular as long as it is located and can be sandwiched between the front side backing plate and the back side pressing member and fixed to the heat insulating portion.

As shown in (A), the expansion member 31c shown in FIG. 14 is composed of a first divided body 31c1 and a second divided body 31c2. Then, as shown in (B), the first divided body 31c1 and the second divided body 31c2 are joined by the mating portion 40c, so that the shape of the expansion member 31c is obtained. The shape of the outer edge of the expansion member 31c is rectangular, and the shape of the inner edge is rectangular. At this time, a gap may or may not be provided between the mating portions 40c. When no gap is provided, it is possible to reliably keep the heat in the lower part and the middle part of the bore wall of the cylinder bore to be kept warm. When a gap is provided between the mating portions 40c, it is desirable that the width dimension of the gap is, for example, about 0.5 to 2.0 mm. When such a gap is provided, the cooling water is replaced little by little from this gap. Therefore, when the internal combustion engine is operated for a long time or the internal combustion engine is operated at a high rotation speed, heat can be released to the outside of the cooling water holding portion 25 by the alternating cooling water, and the cylinder bore to be kept warm. It is possible to prevent the temperature of the bore wall of the internal combustion engine from rising too high.

As shown in (A), the expansion member 31d shown in FIG. 15 is composed of a first divided body 31d1 and a second divided body 31d2. Then, as shown in (B), the first divided body 31d1 and the second divided body 31d2 are joined by the mating portion 40d, so that the shape of the expansion member 31d is obtained. The shape of the outer edge of the expansion member 31d is rectangular, and the shape of the inner edge is rectangular. At this time, a gap may or may not be provided between the mating portions 40d. The effect when the gap is not provided and the effect when the gap is provided are the same as in the example of FIG.

As shown in (A), the expansion member 31e shown in FIG. 16 is composed of a first divided body 31e1, a second divided body 31e2, a third divided body 31e3, and a fourth divided body 31e4. Then, as shown in (B), the first divided body 31e1, the second divided body 31e2, the third divided body 31e3, and the fourth divided body 31e4 are joined by the mating portion 40e, so that the shape of the expansion member 31e is changed. Become. The shape of the outer edge of the expansion member 31e is rectangular, and the shape of the inner edge is rectangular. At this time, a gap may or may not be provided between the mating portions 40e. The effect when the gap is not provided and the effect when the gap is provided are the same as in the example of FIG.

That is, the expansion member related to the cylinder bore wall heat insulating device of the first aspect of the present invention and the cylinder bore wall heat insulating device of the second aspect of the present invention may be composed of a plurality of divided bodies. The number of the divided bodies is preferably 2 or 4, because the shapes of the divided bodies are the same or symmetrical to each other, so that the divided bodies can be easily produced or the manufacturing cost can be reduced.

As shown in (A), the expansion member 31f shown in FIG. 17 is composed of a first divided body 31f1 and a second divided body 31f2. Then, as shown in (B), the first divided body 31f1 and the second divided body 31f2 are joined by the mating portion 40f, so that the shape of the expansion member 31f is obtained. The shape of the outer edge of the expansion member 31f is rectangular, and the shape of the inner edge is rectangular. In the expansion member 31f, the convex portion 412 formed on one side of the divided body and the concave portion 411 formed on the other side of the divided body engage with each other to form the first divided body 31f1 and the second divided body 31f2. It is aligned by the mating portion 40f. At this time, a gap may or may not be provided between the mating portions 40f. The effect when the gap is not provided and the effect when the gap is provided are the same as in the example of FIG.

FIG. 18 shows an enlarged view of the vicinity of the mating portion 40f of the expansion member 31f. As shown in (A), the convex portion 412 formed in the first divided body 31f1 and the concave portion 411 formed in the second divided body 31f2 are engaged with each other. From this state, even if the first divided body 31f1 moves in the lateral direction 461, the convex portion 412 of the first divided body pushes the horizontal portion 401f of the concave portion 411 of the second divided body, so that the first divided body 31f and the first divided body 31f It is possible to prevent the dichotomous body 31f from separating. On the other hand, as shown in (B), when the second divided body 31f2 moves in the vertical direction 462, a gap 47 is generated between the first divided body 31f and the second divided body 31f. However, if the amount of movement of the second divided body 31f2 is within the length of the vertical portion 401f of the recess 411 of the second divided body, the first divided body 31f1 and the second divided body 31f2 are completely separated. There is no. Then, if the amount of movement of the second divided body 31f2 is within the range of the length of the vertical portion 401f of the recess 411 of the second divided body, the vertical portion 401f of the recess 411 of the second divided body is the first divided body. Since it is in contact with the convex portion 412 of the above, this contact portion serves as a sealing portion for preventing the cooling water from flowing out of the expansion member 31f from the cooling water holding portion.

As shown in (A), the expansion member 31g shown in FIG. 19 is composed of a first division body 31g1, a second division body 31g2, a third division body 31g3, and a fourth division body 31g4. Then, as shown in (B), the first divided body 31 g1, the second divided body 31 g2, the third divided body 31 g3, and the fourth divided body 31 g4 are joined by the mating portion 40 g, so that the shape of the expansion member 31 g is obtained. Become. The shape of the outer edge of the expansion member 31g is rectangular, and the shape of the inner edge is rectangular. In the expansion member 31g, the convex portion 412 formed on one side of the divided body and the concave portion 411 formed on the other side of the divided body are engaged with each other, so that the first divided body 31 g1 and the second divided body 31 g2 are second. The three-divided body 31g3 and the fourth divided body 31g4 are combined by the mating portion 40g. The functions of the convex portions or the concave portions formed in the first divided body 31 g1, the second divided body 31 g2, the third divided body 31 g3, and the fourth divided body 31 g4 are the same as the functions of the convex portions and the concave portions shown in FIG. .. At this time, a gap may or may not be provided between the mating portions 40g. The effect when the gap is not provided and the effect when the gap is provided are the same as in the example of FIG.

That is, the expansion member related to the cylinder bore wall heat insulating device of the first aspect of the present invention and the cylinder bore wall heat insulating device of the second aspect of the present invention is composed of a plurality of divided bodies, and one of the divided bodies is formed. The convex portion formed on the surface and the concave portion formed on the other side of the divided body are fitted by engaging with each other. Then, the expansion member is composed of a plurality of divided bodies, and the convex portion formed on one side of the divided body and the concave portion formed on the other side of the divided body are engaged with each other to be combined with each other. Even if a part of the body is moved by vibration, it is possible to prevent the split body from being completely separated and to prevent the cooling water from flowing out of the expansion member from the cooling water holding portion.

In the expansion member 31d shown in FIG. 15, since the shape of the outer edge and the shape of the inner edge are rectangular, as shown in FIG. 20, the expansion member 31d is cut out from one large expansion material sheet to form the first division 31d1 of the expansion member 31d. When the second divided body 31d2 is produced, the first divided body 31d1 is punched out in order from the left, and then the inner edge of the first divided body 31d1 is matched with the outer edge of the second divided body 31d2 to form the second divided body 31d2. Punching, then punching the first division 31d1 by matching the outer edge of the first division 31d1 with the inner edge of the second division 31d2, and then matching the outer edge of the second division 31d2 with the inner edge of the first division 31d1. The divided body can be produced by repeating the process of punching out the second divided body 31d2.

Further, in the expansion member 31f shown in FIG. 17, since the shape of the outer edge and the shape of the inner edge are rectangular, as shown in FIG. 21, a first divided body of the expansion member 31f is cut out from one large expansion material sheet. When the 31f1 and the second divided body 31f2 are produced, the first divided body 31f1 is punched out in order from the left, and then the outer edge of the second divided body 31f2 is positioned near the inner edge of the first divided body 31f1. The divided body 31d2 is punched out, then the outer edge of the first divided body 31f1 is positioned near the inner edge of the second divided body 31f2, and the first divided body 31f1 is punched out. The divided body can be produced by repeating the process of positioning the outer edge of the divided body 31f2 and punching out the second divided body 31f2.

In the expansion member 31e shown in FIG. 16, since the shape of the outer edge and the shape of the inner edge are rectangular, as shown in FIG. 22, the expansion member 31e is cut out from one large expansion material sheet to be combined with the first division 31e1 of the expansion member 31e. When the second divided body 31e2, the third divided body 31e3, and the fourth divided body 31e4 are produced, the first divided body 31e1 is punched out in order from the left, and then the third divided body 31e3 is formed on the inner edge of the first divided body 31e1. The outer edges of the first divided body 31e3 are matched with each other to punch out the third divided body 31e3, then the outer edge of the first divided body 31e1 is matched with the inner edge of the third divided body 31e3 to punch out the first divided body 31e1, and then the first divided body 31e1 is punched out. The outer edge of the third divided body 31e3 is matched with the inner edge of the third divided body 31e3, and the third divided body 31e3 is punched out repeatedly. The outer edges of the fourth divided body 31e4 are matched to punch out the fourth divided body 31e4, then the inner edge of the fourth divided body 31e4 is matched with the outer edge of the second divided body 31e2 to punch out the second divided body 31e2, and then the second divided body 31e2 is punched out. The divided body can be produced by repeating the process of matching the outer edge of the fourth divided body 31e4 with the inner edge of the second divided body 31e2 and punching out the fourth divided body 31e4.

That is, the expansion member related to the cylinder bore wall heat insulating device of the first aspect of the present invention and the cylinder bore wall heat insulating device of the second aspect of the present invention is composed of a plurality of divided bodies, and the outer edge and the inner edge are rectangular. Therefore, when the divided body is cut out from the raw material sheet for the expansion member to be produced, the inner edge of one divided body is made to match the outer edge of the other divided body, or the vicinity of the inner edge of the one divided body. Since the outer edge of the other divided body can be positioned in the divided body, the divided body can be manufactured from the raw material sheet for the expanding member having the same size as compared with the case where the expanding member is composed of one member. Many expansion members can be made. That is, when the expansion member is composed of one member, the portion cut out to form the space portion cannot be used for manufacturing another expansion member, so that the portion corresponding to the space portion is Everything is wasted. On the other hand, when the expansion member is composed of a plurality of divided bodies and the outer edge and the inner edge are rectangular, all or a part of the portion corresponding to the space portion of one divided body is the other one. Since it is used for producing the divided body of the above, there is little waste of the raw material sheet. Therefore, the expansion member related to the cylinder bore wall heat insulating device of the first aspect of the present invention and the cylinder bore wall heat insulating device of the second aspect of the present invention is composed of a plurality of divided bodies, and the outer edge and the inner edge are formed. The rectangular shape makes it possible to increase the yield of the raw material sheet of the expansion material.

Next, the first to eleventh embodiments of the convex portion (bead) and its peripheral structure relating to the cylinder bore wall heat insulating device of the first aspect of the present invention and the cylinder bore wall heat insulating device of the second aspect of the present invention will be described. do.
[First Embodiment of the convex portion]

A first embodiment of the convex portion (bead) of the heat insulating device 36a and its peripheral structure will be described with reference to FIGS. 23 and 24.
The heat insulating device 36a has a fixing member. As the fixing member, the elastic member attachment member 33, the back side pressing member 32, the expansion member 31a, and the front side backing plate 30 are fixed to each other. The fixing member is provided integrally with the elastic member attachment member 33 as an example, but may be provided separately from the elastic member attachment member 33.

The fixing member is provided corresponding to a plurality of bent portions 332a and 332b provided corresponding to the pair of non-curved sides 41 of the front side backing plate 30 and the pair of curved sides 42 of the front side backing plate 30. It has a plurality of bent portions 331a and 331b. The plurality of bent portions 332a and 332b and the plurality of bent portions 331a and 331b are all provided on the outer peripheral portion (near the outer edge) of the heat insulating tool 36a.

The bent portions 332a and 332b are formed as sheet metal extending in the vertical direction (direction orthogonal to the flow direction S of the cooling water), and are continuously provided over the entire length of the heat insulating tool 36a in the vertical direction. The bent portion 332a is provided at the right end portion of the heat insulating tool 36a, and the bent portion 332b is provided at the left end portion of the heat insulating tool 36a.

The bent portions 331a and 331b are formed in a strip shape as a sheet metal extending in the lateral direction (cooling water flow direction S) with a predetermined width. The plurality of bent portions 331a and 331b are located at positions moved from the left end of the curved side 42 of the front side backing plate 30 by a length of 1/3 of the total length of the curved side 42, and the curved side 42 of the front side backing plate 30. There are two locations (a total of four locations when the upper bent portion 331a and the lower bent portion 331b are combined) with the position moved from the right end of the curved side 42 by the length of 1/3 of the total length of the curved side 42. It is provided.

The bent portions 331a, 331b, 332a, and 332b are sheet metals formed so as to project from the elastic member attachment member 33, and are bent into a substantially U shape by being caulked (bent) by a press machine. Therefore, the bent portions 331a, 331b, 332a, and 332b form sandwiching portions. The bent portions 331a, 331b, 332a, and 332b sandwich the back side pressing member 32, the expanding member 31a, and the front side backing plate 30 between the bent portions 331a, 331b, 332a, and 332b and the elastic member attachment member 33. These can be retained. The bent portions 331a, 331b, 332a, and 332b fix the elastic member attachment member 33, the back side pressing member 232, the expansion member 31a, and the front side backing plate 30 to each other.

The bent portions 331a, 331b, 332a, and 332b are not limited to the bending process of the sheet metal, and may be formed by, for example, screws, rivets, eyelets, welding, brazing, burring, and the like.

As described above, the elastic member attachment member 33 is provided with a plurality of metal springs 39. The metal spring 39 has a shaft portion 28A and a contact portion 28B provided at the tip end portion of the shaft portion 28A. The contact portion 28B is arranged so as to bend with respect to the shaft portion 28A, and can contact the wall surface 18 on the side opposite to the wall surface 17 on the cylinder bore 13 side.

As shown in FIGS. 23 and 24, the front side backing plate 30 is formed by bending a square frame-shaped flat plate so as to be curved along the wall surface 17 of the cylinder bore wall 13. The front side backing plate 30 has a rectangular first opening 46. The front side backing plate 30 is formed of a metal plate, for example, a stainless steel plate. The front side backing plate 30 has a pair of non-curved sides 41 extending in the vertical direction and a pair of curved sides 42 extending in the horizontal direction. Further, the front side backing plate 30 has a pair of vertical frame portions 27A extending in the vertical direction corresponding to the pair of non-curved sides 41 and a pair of horizontal frame portions 27B extending in the horizontal direction corresponding to the pair of curved sides 42. And have. One vertical frame portion 27A on the left side is sandwiched and held by one bent portion 332b on the left side. One vertical frame portion 27A on the right side is sandwiched and held by one bent portion 332a on the right side.

The horizontal frame portion 27B of the front side backing plate 30 has a plurality of convex portions 302a and 302b. The plurality of convex portions 302a and 302b are provided on both sides of the bent portions 331a and 331b. Alternatively, it can be said that the plurality of convex portions 302a and 302b are provided between the bent portions 331a and 331b.

As shown in FIGS. 23 and 24, the convex portions 302a and 302b extend laterally along the curved side 42 of the front side backing plate 30. The convex portions 302a and 302b are provided so as to project toward the expansion member 31a (back surface side pressing member 32) so as to be convex. The plurality of convex portions 302a and 302b are provided in series in the horizontal frame portion 27B.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. In the present embodiment, since the convex portions 302a and 302b are provided on both sides of the bent portions 331a and 331b, the cooling water enters between the back surface side pressing member 32 and the expansion member 31a from this position. It is prevented from being stowed. As a result, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a at the positions where the convex portions 302a and 302b are provided. Therefore, it is possible to prevent the expansion member 31a floating from the back surface pressing member 32 from falling off.

The following second to seventh embodiments mainly describe parts different from the first embodiment of the convex portion, and illustration and description of parts common to the first embodiment of the convex portion will be omitted.
[Second Embodiment of Convex Part]

The heat insulating tool 36a of the cylinder bore wall of the second embodiment will be described with reference to FIGS. 25 and 26.

As shown in FIGS. 25 and 26, the expansion member 31a is formed to have a substantially rectangular flat plate shape and to be curved along the cylinder bore wall 15. The expansion member 31a is made of a rubber material that expands when the temperature rises. It is a member for directly contacting the cylinder bore wall 15 of the cylinder bore 13 to cover the heat retaining portion of the cylinder bore wall 15 and keeping the cylinder bore wall 15 of each cylinder bore 13 warm.

As shown in FIG. 26, the expansion member 31a has a space between a first notch 52 provided at a position corresponding to a corner of the square and a second notch 53 provided at a position between the bent portions 331a and 331b. It has a part 25 and. The first notch 52 is provided so as to remove the corner portion at a position separated from the plurality of fixed portions. The first notch 52 is located outside the bent portions 331a and 331b (on the end side with respect to the cooling water flow direction S). The first notch 52 is provided corresponding to the convex portions 302a and 302b, and the expansion member 31a is provided so as to avoid the convex portions 302a and 302b.

The second notch 53 is provided so as to retreat to the center side of the expansion member 31a from the portion corresponding to the bent portions 331a and 331b. However, the second notch 53 is not provided so as to avoid the convex portions 302a and 302b. Therefore, the expansion member 31a has a holding portion 54 that overlaps with the convex portions 302a and 302b at a position adjacent to the second notch portion 53. Therefore, at this position, the holding portion 54 constitutes the outer edge of the expansion member 31a. At this position, the expansion member 31a is not arranged outside the holding portion 54. The holding portion 54 of the expansion member 31a is sandwiched and held between the convex portions 302a and 302b and the back side pressing member 32.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. In the present embodiment, the first notch 52 is provided at the position of the corner where the influence of the flow velocity of the cooling water is large. Therefore, the expansion member 31a is not arranged at this position, and the expansion member 31a is prevented from being torn or damaged at this position. Further, on the outside of the first notch 52, convex portions 302a and 302b are arranged so as to protect the first notch 52. Therefore, it is further prevented that the expansion member 31a is torn or damaged at this position. The holding portion 54 adjacent to the second cutout portion 53 is sandwiched and held between the convex portions 302a and 302b and the back surface side pressing member 32. Therefore, at the position where the holding portion 54 is provided, the adhesion between the expansion member 31a and the back side pressing member 32 can be improved. As a result, it is possible to prevent the cooling water from entering between the expansion member 31a and the back surface pressing member 32 in the vicinity of the second notch 53. As a result, it is possible to prevent the expansion member 31a from falling off from the heat insulating tool 36a on the cylinder bore wall.

According to the second embodiment, the following can be said. The expansion member 31a has a first notch 52 provided so as to remove a corner portion at a position separated from the fixing portion. According to this configuration, since the cutout portion is provided at the position of the corner portion where tearing is likely to occur due to the influence of the flow of the cooling water, it is possible to prevent the expansion member 31a from having a problem such as tearing.

The expansion member 31a is provided with a second notch 53 provided at a position between the plurality of fixed portions, and the convex portions 302a and 302b provided adjacent to the second notch 53 and the back side pressing member. It has a holding portion 54 that is sandwiched and held between the 32 and the 32. According to this configuration, the expansion member 31a is not arranged on the outside of the holding portion 54. Therefore, it is possible to prevent the expansion member 31a from being torn around the holding portion 54 due to the influence of the flow of the cooling water. Further, since the holding portion 54 is sandwiched and held between the convex portions 302a and 302b and the back side pressing member 32, the adhesion between the back side pressing member 32 and the expansion member 31a is maintained at this position. improves. Therefore, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a. As a result, it is possible to prevent the expansion member 31a from being lifted from the back surface pressing member 32, and to prevent the expansion member 31a from falling off from the heat insulating tool 36a.
[Third Embodiment of the convex portion]

The heat insulating device 36a of the cylinder bore wall of the third embodiment will be described with reference to FIGS. 27 to 30.

As shown in FIGS. 27 to 30, the expansion member 31a has a plurality of through holes 55 provided so as to correspond to the plurality of convex portions 302a and 302b. The plurality of through holes 55 are formed in an elongated elongated hole shape along the pair of curved sides 42 of the front side backing plate 30 (along the flow direction S of the cooling water). Therefore, in the present embodiment, the plurality of convex portions 302a and 302b are inserted into the plurality of through holes 55. The plurality of through holes 55 provided in the expansion member 31a can be formed by punching the expansion member 31a in the thickness direction with, for example, an oval mold or the like.

As shown in FIG. 30, the height h of the convex portions 302a and 302b of the present embodiment is substantially the same as the thickness t of the expansion member 31a. In the present embodiment, as shown in FIGS. 29 and 30, the back side pressing member 32 may be omitted.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. In the present embodiment, the convex portions 302a and 302b are passed through the inside of the through hole 55. Therefore, the expansion member 31a will not fall off from the heat insulating tool 36a unless the expansion member 31a is torn off. Therefore, in the present embodiment, the position of the expansion member 31a is stable, and there is no problem that the expansion member 31a moves with respect to the heat insulating tool 36a.

According to the third embodiment, the following can be said. The heat insulating tool 36a on the cylinder bore wall is provided on the expansion member 31a and has one or more through holes 55 through which the one or more convex portions 302a and 302b are passed. According to this configuration, it is possible to prevent the expansion member 31a from falling off from the heat insulating device 36a as much as possible.
[Fourth Embodiment of the convex portion]

The heat insulating tool 36a of the cylinder bore wall of the fourth embodiment will be described with reference to FIGS. 31 and 32. In the following fourth to tenth embodiments, the illustration of the base member 34a is omitted.

The fixing member is provided corresponding to a plurality of bent portions 332a and 332b provided corresponding to the pair of non-curved sides 41 of the front side backing plate 30 and the pair of curved sides 42 of the front side backing plate 30. It has a plurality of bent portions 331a and 331b. The plurality of bent portions 332a and 332b and the plurality of bent portions 331a and 331b are all provided on the outer peripheral portion (near the outer edge) of the heat insulating tool 36a.

The bent portions 332a and 332b are formed as sheet metal extending in the vertical direction, and are continuously provided over the entire length of the heat insulating tool 36a in the vertical direction. One of the bent portions 332a and 332b is provided at the left end of the heat insulating device 36a, and the other one of the bent portions 332a and 332b is provided at the right end of the heat insulating device.

The bent portions 331a and 331b are formed in a strip shape as a sheet metal extending in the lateral direction with a predetermined width. The plurality of bent portions 331a and 331b are provided at two positions above and below the position corresponding to the intermediate portion of the curved side 42 of the front side backing plate 30.

The horizontal frame portion 27B of the front side backing plate 30 has a plurality of convex portions 302a and 302b. The plurality of convex portions 302a and 302b are provided on both sides of the bent portions 331a and 331b. The convex portions 302a and 302b extend laterally along the curved side 42 of the front side backing plate 30. The convex portions 302a and 302b are provided so as to project toward the expansion member 31a so as to be convex. The plurality of convex portions 302a and 302b are provided in series in the horizontal frame portion 27B.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. Since the convex portions 302a and 302b are provided on both sides of the bent portions 331a and 331b, it is possible to prevent the cooling water from entering between the back side pressing member 32 and the expanding member 31a from this position. NS. As a result, it is possible to prevent the expansion member 31a from floating from the back surface pressing member 32 and causing the expansion member 31a to fall off. Further, in the present embodiment, the number of bent portions 331a and 331b is reduced as compared with the first embodiment and the like. Therefore, the number of man-hours required for bending the bent portions 331a and 331b into a substantially U shape is reduced.

According to the fourth embodiment, the following can be said. The front side backing plate 30 has a pair of curved sides 42 and a pair of non-curved sides 41, and the plurality of fixing portions are provided at predetermined positions of the pair of curved sides 42, and the plurality of fixed portions are provided. The convex portions 302a and 302b of the above are provided on both sides of the pair of curved sides 42 with the predetermined position interposed therebetween.

According to this configuration, since the convex portions 302a and 302b are provided along the curved side 42, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a from this position. NS. As a result, it is possible to prevent the expansion member 31a that has risen from the back surface pressing member 32 from falling off from the heat insulating tool 36a on the cylinder bore wall. Further, by arranging the convex portions 302a and 302b instead of the fixed portions, the number of the fixed portions can be reduced. As a result, when assembling the heat insulating tool 36a on the cylinder bore wall, the man-hours required for fixing the fixing portion can be reduced, and the assembling work can be simplified.
[Fifth Embodiment of the convex portion]

The heat insulating tool 36a of the cylinder bore wall of the fifth embodiment will be described with reference to FIGS. 33 and 34.

The fixing member has a plurality of bent portions 332a and 332b provided corresponding to the pair of non-curved sides 41 of the front side backing plate 30. The fixing member of the present embodiment does not include the bent portions 331a and 331b extending in the lateral direction. The plurality of bent portions 332a and 332b are provided on the outer peripheral portion (near the outer edge) of the heat insulating tool 36a.

The bent portions 332a and 332b are formed as sheet metal extending in the vertical direction, and are continuously provided over the entire length of the heat insulating tool 36a in the vertical direction. One of the bent portions 332a and 332b is provided at the left end portion of the heat insulating tool 36a, and the other one of the first fixing portions is provided at the right end portion of the heat insulating tool 36a.

The horizontal frame portion 27B of the front side backing plate 30 has a plurality of convex portions 302a and 302b. The plurality of convex portions 302a and 302b are provided over substantially the entire width of the front side backing plate 30 in the lateral direction (cooling water flow direction S). The convex portions 302a and 302b extend laterally along the curved side 42 of the front side backing plate 30. The convex portions 302a and 302b are provided so as to project toward the expansion member 31a so as to be convex. The plurality of convex portions 302a and 302b are continuously provided in the horizontal frame portion 27B, but some of them may be discontinuous.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. Since the convex portions 302a and 302b are provided over substantially the entire width of the front side backing plate 30 in the lateral direction, cooling water may enter between the back side pressing member 32 and the expansion member 31a from this position. Be prevented. As a result, it is possible to prevent the expansion member 31a that has risen from the back surface pressing member 32 from falling off from the heat insulating tool 36a on the cylinder bore wall. Further, in the present embodiment, the bent portions 331a and 331b are omitted. Therefore, the work required for bending the bent portions 331a and 331b into a substantially U shape is reduced.

According to the fifth embodiment, the following can be said. In the cylinder bore wall heat insulating tool 36a, the front side backing plate 30 has a pair of curved sides 42 and a pair of non-curved sides 41, and the one or more fixing portions are the pair of non-curved sides 41. The one or more convex portions 302a and 302b are provided along the pair of curved sides 42, and are not provided at the positions corresponding to the pair of curved sides 42.

According to this configuration, since the convex portions 302a and 302b are provided along the curved side 42, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a from this position. NS. As a result, it is possible to prevent a problem that the expansion member 31a that has risen from the back surface pressing member 32 falls off. Further, by arranging the convex portions 302a and 302b instead of the fixed portions, the number of the fixed portions can be reduced. As a result, when assembling the heat insulating tool 36a on the cylinder bore wall, the man-hours required for fixing the fixing portion can be reduced, and the assembling work can be simplified.
[Sixth Embodiment of the convex portion]

The heat insulating device 36a of the cylinder bore wall of the sixth embodiment will be described with reference to FIGS. 35 and 36.

The fixing member has a plurality of bent portions 332a and 332b provided corresponding to the pair of non-curved sides 41 of the front side backing plate 30. The fixing member of the present embodiment does not include the bent portions 331a and 331b extending in the lateral direction. The plurality of bent portions 332a and 332b are all provided on the outer peripheral portion (near the outer edge) of the heat insulating tool 36a.

The vertical frame portion 27A and the horizontal frame portion 27B of the front side backing plate 30 have a plurality of convex portions 302a, 302b, and 302. The plurality of convex portions 302a and 302b are provided along the curved side 42 of the front side backing plate 30 over substantially the entire width in the lateral direction (cooling water flow direction S) of the front side backing plate 30. One of the convex portions 302a and 302b extending in the lateral direction is provided on the upper horizontal frame portion 27B, and the other one of the convex portions 302a and 302b extending in the lateral direction is provided on the lower horizontal frame portion 27B. ..

The plurality of convex portions 302 are provided along the non-curved side 41 of the front side backing plate 30 over substantially the entire width in the vertical direction (direction orthogonal to the cooling water flow direction S) of the front side backing plate 30. There is. One of the convex portions 302 extending in the vertical direction is provided in the vertical frame portion 27A on the left side, and the other one of the convex portions 302 extending in the vertical direction is provided in the vertical frame portion 27A on the right side. The convex portion 302 provided on the vertical frame portion 27A is provided between the bent portions 332a and 332b.

The convex portions 302a, 302b, and 302 are provided so as to project toward the expansion member 31a so as to be convex. The plurality of convex portions 302a, 302b, 302 are continuously provided in the horizontal frame portion 27B or the vertical frame portion 27A, but some of them may be discontinuous.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. Since the convex portions 302a and 302b are provided between the bent portions 332a and 332b, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a from this position. Further, a pair of convex portions 302a and 302b extending in the lateral direction along the curved side 42 are provided. As a result, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a at the positions where the convex portions 302a and 302b are provided. As a result, it is possible to prevent the expansion member 31a that has risen from the back surface pressing member 32 from falling off from the heat insulating tool 36a on the cylinder bore wall. Further, in the present embodiment, the bent portions 331a and 331b are omitted. Therefore, the work required for bending the bent portions 331a and 331b into a substantially U shape is reduced.

According to the sixth embodiment, the following can be said. The front side backing plate 30 has a pair of curved sides 42 and a pair of non-curved sides 41, and the plurality of fixing portions are provided at a plurality of positions on the pair of non-curved sides 41. One or more convex portions 302a and 302b are provided between the plurality of fixed portions along the pair of non-curved sides 41.

According to this configuration, since the convex portions 302a and 302b are provided along the non-curved side 41, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expanding member 31a from this position. Will be done. As a result, it is possible to prevent the expansion member 31a from floating from the back surface pressing member 32 and causing the expansion member 31a to fall off.
[7th embodiment of the convex portion]

The heat insulating tool 36a of the cylinder bore wall of the seventh embodiment will be described with reference to FIGS. 37 to 40.

As shown in FIGS. 37 and 38, the fixing member includes a plurality of bent portions 332a and 332b provided corresponding to the pair of non-curved sides 41 of the front side backing plate 30, and a pair of front side backing plates 30. It has a plurality of bent portions 331a and 331b provided corresponding to the curved side 42. The plurality of bent portions 332a and 332b and the plurality of bent portions 331a and 331b are all provided on the outer peripheral portion (near the outer edge) of the heat insulating tool 36a.

The bent portions 332a and 332b are formed as sheet metal extending in the vertical direction, and are continuously provided in the vertical direction of the heat insulating tool 36a. The bent portions 332a and 332b are provided in a substantially intermediate portion in the vertical direction of the heat insulating tool 36a. The bent portions 332a and 332b hold two-thirds or more of the length of the front side backing plate 30 in the vertical direction. One of the bent portions 332a and 332b is provided at the left end portion of the heat insulating tool 36a, and the other one of the bent portions 332a and 332b is provided at the right end portion of the heat insulating tool 36a.

The bent portions 331a and 331b are formed in a strip shape as a sheet metal extending in the lateral direction with a predetermined width. The plurality of bent portions 331a and 331b are discretely provided at predetermined positions on the curved side 42 of the front side backing plate 30.

As shown in FIG. 38, the back side pressing member 32 has a plurality of convex portions 302a and 302b at positions corresponding to the horizontal frame portion 27B of the front side backing plate 30. The plurality of convex portions 302a and 302b are provided on both sides of the bent portions 331a and 331b. Alternatively, it can be said that the plurality of convex portions 302a and 302b are provided between the bent portions 331a and 331b.

The convex portions 302a and 302b extend laterally along the curved side 42 of the front side backing plate 30. As shown in FIGS. 53 and 54, the convex portions 302a and 302b are provided so as to project so as to be convex toward the front side backing plate 30. The plurality of convex portions 302a and 302b are provided in series at positions corresponding to the horizontal frame portion 27B.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. Since the convex portions 302a and 302b are provided between the bent portions 331a and 331b, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a from this position. Therefore, it is possible to prevent the expansion member 31a floating from the back surface pressing member 32 from falling off from the heat insulating tool 36a on the cylinder bore wall.

According to the seventh embodiment, the following can be said. The heat insulating tool 36a on the cylinder bore wall has a shape in which a plurality of arcs are continuous, and has a base member 34a having a second opening 42 in each arc and at least one fixed to one of the plurality of arcs. It has a heat insulating device 36a and. The heat insulating tool 36a comes into contact with the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path 14, and is provided with an expansion member 31a for covering the wall surface 17 and an expansion member 31a on the back surface side of the expansion member 31a. It has a back side pressing member 32 for pressing from the back side toward the wall surface 17 on the cylinder bore side of the groove-shaped cooling water flow path 14, and a first opening 301 provided on the contact surface side of the expansion member 31a. A front side backing plate 30 for sandwiching the outer edge portion of the expansion member 31a between the back side pressing member 32, an elastic member attached member 33 provided on the back side of the back side pressing member 32, and the elastic member. An elastic member provided in the attachment member 33, which can be inserted into the opening, and which abuts on the opposite wall 23 of the groove-shaped cooling water flow path 14 facing the wall surface 22 so as to press the expansion member 31a toward the wall surface 22. One or more fixing members sandwiching the back surface pressing member 32, the expanding member 31a, and the front surface backing plate 30 between the 28 and the elastic member attachment member 33, and the one or more fixing members are separated from each other. One or more convex portions 302a, 302b, 302 provided on the back side pressing member 32 at a position, projecting toward the expanding member 31a, and sandwiching the expanding member 31a with the front side backing plate 30. Be prepared.

According to this configuration, since one or more convex portions 302a and 302b are provided at positions separated from the fixing member, the pressure for compressing the expansion member 31a can be increased at the positions of the convex portions 302a and 302b. Therefore, the adhesion of the expansion member 31a to the back side pressing member 32 is improved at the position where the convex portions 302a and 302b are provided, and it is possible to prevent a gap from being formed between the back side pressing member 32 and the expansion member 31a. NS. Therefore, the cooling water in the groove-shaped cooling water flow path 14 is prevented from entering between the back surface side pressing member 32 and the expansion member 31a. As a result, it is possible to prevent the expansion member 31a that has risen from the back surface pressing member 32 from falling off from the heat insulating device 36a. Further, since the holding force for holding the expansion member 31a between the back side pressing member 32 and the front side backing plate 30 increases, the expansion member 31a may be torn by the water flow of the cooling water, or the expansion member 36a may expand. It is possible to prevent the member 31a from falling off. Further, by arranging the convex portions 302a, 302b, 302 instead of the fixing member, the total number of the fixing members can be reduced, and thereby the man-hours required for fixing the fixing portion at the time of assembling the heat insulating tool 36a can be reduced. Therefore, the efficiency of the assembling work of the heat insulating tool 36a can be improved.

The following eighth and ninth embodiments mainly describe parts different from the above seventh embodiment, and illustration and description of parts common to the seventh embodiment will be omitted.
[Eighth embodiment of the convex portion]

The heat insulating device 36a of the cylinder bore wall of the eighth embodiment will be described with reference to FIG. 41.

The back side pressing member 32 has a plurality of convex portions 302a and 302b at positions corresponding to the horizontal frame portion 27B of the front side backing plate 30. The arrangement of the plurality of convex portions 302a and 302b is the same as that of FIG. 52 of the seventh embodiment. The plurality of convex portions 302a and 302b are provided on both sides of the bent portions 331a and 331b. Alternatively, it can be said that the plurality of convex portions 302a and 302b are provided between the bent portions 331a and 331b.

The expansion member 31a has a plurality of through holes 55 provided so as to correspond to the plurality of convex portions 302a and 302b. The plurality of through holes 55 are formed in an elongated elongated hole shape along the pair of curved sides 42 of the front side backing plate 30. The plurality of through holes 55 are provided at positions that overlap with the plurality of convex portions 302a and 302b in FIG. 52. In the present embodiment, the plurality of convex portions 302a and 302b are inserted into the plurality of through holes 55. An example of the structure is shown in FIG. 55. The plurality of through holes 55 provided in the expansion member 31a can be formed by punching the expansion member 31a in the thickness direction with, for example, an oval mold.

As shown in FIG. 41, the height h of the convex portions 302a and 302b of the present embodiment is substantially the same as the thickness t of the expansion member 31a.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. In the present embodiment, the convex portions 302a and 302b are passed through the inside of the through hole 55. Therefore, as long as the covering member is not torn, the covering member will not fall off from the heat insulating device. Therefore, in the present embodiment, the position of the covering member is stable, and there is no problem that the expansion member 31a moves with respect to the back surface side pressing member 32.

According to the eighth embodiment, the following can be said. The heat insulating tool 36a on the cylinder bore wall is provided on the expansion member 31a and has one or more through holes 55 through which the one or more convex portions 302a and 302b are passed. According to this configuration, it is possible to prevent as much as possible the risk that the expansion member 31a may fall off from between the back side pressing member 32 and the front side backing plate 30.
[9th embodiment of the convex portion]

The heat insulating device 36a of the cylinder bore wall of the ninth embodiment will be described with reference to FIG. 42. In FIG. 42, the expansion member 31a is not shown.

The fixing member has bent portions 332a and 332b provided corresponding to the pair of non-curved sides 41 of the front side backing plate 30. The fixing member of the present embodiment does not include the bent portions 331a and 331b extending in the lateral direction. The bent portions 332a and 332b are provided on the outer peripheral portion (near the outer edge) of the heat insulating tool 36a.

The bent portions 332a and 332b are formed as sheet metal extending in the vertical direction, and are continuously provided over the entire length of the heat insulating tool 36a in the vertical direction. The bent portion 332a is provided at the right end portion of the heat insulating tool 36a, and the bent portion 332b is provided at the left end portion of the heat insulating tool 36a.

The back side pressing member 32 has convex portions 302a and 302b at positions corresponding to the horizontal frame portion 27B of the front side backing plate 30. The convex portions 302a and 302b are provided over substantially the entire width of the back surface side pressing member 32 in the lateral direction (cooling water flow direction S). The convex portions 302a and 302b are provided so as to project toward the expansion member 31a so as to be convex. The convex portions 302a and 302b are continuously provided in the horizontal frame portion 27B, but some of them may be discontinuous.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. In the present embodiment, since the convex portions 302a and 302b are provided over substantially the entire width of the back side pressing member 32 in the lateral direction, cooling water enters between the back side pressing member 32 and the expansion member 31a from this position. It is prevented from doing so. As a result, it is possible to prevent the expansion member 31a from floating from the back surface pressing member 32 and causing the expansion member 31a to fall off. Further, in the present embodiment, the bent portions 331a and 331b are omitted. Therefore, the work required for bending the bent portions 331a and 331b into a substantially U shape is reduced.

According to the ninth embodiment, the following can be said. In the cylinder bore wall heat insulating tool 36a, the back side pressing member 32 has a pair of curved sides 42 and a pair of non-curved sides 41, and the one or more fixing portions are the pair of non-curved sides 41. The one or more convex portions 302a and 302b are provided along the pair of curved sides 42, and are not provided at the positions corresponding to the pair of curved sides 42. According to this configuration, since the convex portions 302a and 302b are provided along the curved side 42, the pressure at which the expansion member 31a is compressed at the positions of the convex portions 302a and 302b is improved. Therefore, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a from this position. As a result, it is possible to prevent the expansion member 31a that has risen from the back surface pressing member 32 from falling off from the heat insulating tool 36a on the cylinder bore wall. Further, by arranging the convex portions 302a and 302b instead of the fixed portions, the number of the fixed portions can be reduced. As a result, when assembling the heat insulating tool 36a on the cylinder bore wall, the man-hours required for fixing the fixing portion can be reduced, and the assembling work can be simplified.
[10th embodiment of the convex portion]

The heat insulating device 36a of the cylinder bore wall of the tenth embodiment will be described with reference to FIG. 43. In FIG. 43, the expansion member 31a is not shown.

The fixing member has a plurality of bent portions 332a and 332b provided corresponding to the pair of non-curved sides 41 of the front side backing plate 30. The fixing member of the present embodiment does not include the bent portions 331a and 331b extending in the lateral direction. The plurality of bent portions 332a and 332b are provided on the outer peripheral portion (near the outer edge) of the heat insulating tool 36a.

The bent portions 332a and 332b are formed as sheet metal extending in the vertical direction. A pair of bent portions 332a are provided at the right end portion of the heat insulating tool 36a. A pair of bent portions 332b are also provided at the left end portion of the heat insulating tool 36a. A pair of bent portions 332a provided at the right end portion are provided at both ends of the front side backing plate 30 in the vertical direction. The pair of bent portions 332b provided at the left end portion are provided at both ends of the front side backing plate 30 in the vertical direction.

The bent portions 332a and 332b are sheet metals formed so as to project from the elastic member attachment member 33, and are bent into a substantially U shape by being caulked by a press machine. Therefore, the bent portions 332a and 332b form sandwiching portions, and between the bent portions 332a and 332b and the elastic member attachment member 33, the back side pressing member 32, the expanding member 31a, and the front side backing plate 30 Hold these by sandwiching them.

The back side pressing member 32 has a plurality of convex portions 302a, 302b, 302 at positions corresponding to the vertical frame portion 27A and the horizontal frame portion 27B of the front side backing plate 30. The convex portions 302a and 302b are provided along the curved side 42 of the front side backing plate 30 over substantially the entire width in the lateral direction (cooling water flow direction S) of the back side pressing member 32. The convex portion 302a extending in the lateral direction is provided so as to correspond to the upper horizontal frame portion 27B, and the convex portion 302b extending in the lateral direction is provided so as to correspond to the lower horizontal frame portion 27B.

The plurality of convex portions 302 are provided along the non-curved side 41 of the front side backing plate 30 over substantially the entire width in the vertical direction (direction orthogonal to the cooling water flow direction S) of the back side pressing member 32. There is. One of the convex portions 302 extending in the vertical direction is provided so as to correspond to the vertical frame portion 27A on the right side, and the other one of the convex portions 302 extending in the vertical direction corresponds to the vertical frame portion 27A on the left side. It is provided in. The convex portion 302 provided at a position corresponding to the vertical frame portion 27A is provided between the bent portions 332a and 332b.

The convex portions 302a, 302b, and 302 are provided so as to project toward the expansion member 31a so as to be convex. The plurality of convex portions 302a, 302b, 302 are continuously provided at positions corresponding to the horizontal frame portion 27B or the vertical frame portion 27A, but some of them may be discontinuous.

The operation of the heat insulating tool 36a on the cylinder bore wall of the present embodiment will be described. Since the convex portions 302a, 302b, and 302 are provided between the bent portions 332a and 332b, it is possible to prevent the cooling water from entering between the back side pressing member 32 and the expanding member 31a from this position. .. Further, a pair of convex portions 302a and 302b extending in the lateral direction along the curved side 42 are provided. As a result, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expansion member 31a at the positions where the convex portions 302a and 302b are provided. Therefore, it is possible to prevent the expansion member 31a floating from the back surface pressing member 32 from falling off from the heat insulating tool 36a on the cylinder bore wall. Further, in the present embodiment, the bent portions 331a and 331b are omitted. Therefore, the work required for bending the bent portions 331a and 331b into a substantially U shape is reduced.

According to the tenth embodiment, the following can be said. In the cylinder bore wall heat insulating tool 36a, the front side backing plate 30 has a pair of curved sides 42 and a pair of non-curved sides 41, and the plurality of fixing portions are on the pair of non-curved sides 41. The one or more convex portions 302 are provided between the plurality of fixing members along the pair of non-curved sides 41.

According to this configuration, since the convex portion 302 is provided along the non-curved side 41, it is possible to prevent the cooling water from entering between the back surface side pressing member 32 and the expanding member 31a from this position. .. As a result, it is possible to prevent the expansion member 31a from floating from the back surface pressing member 32 and causing the expansion member 31a to fall off.

The internal combustion engine of the present invention is an internal combustion engine characterized in that a heat insulating device for a cylinder bore wall of the present invention is installed.

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

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 Cylinder bore side wall surface 17a, 17b of grooved cooling water flow path 14 One side Half side wall surface 18 Wall surface of grooved cooling water flow path 14 opposite to the cylinder bore side wall surface 21a, 21b One side half bore wall 23a1, 23a2, 23b1, 23b2 Bore wall of each cylinder bore 25 Space part 26 Contact surface 30 Front Side backing plates 31a, 31b, 31c, 31d, 31e, 31f, 31g Expansion member 32 Back side pressing plate 33 Elastic member attachment members 35a, 35b Heat insulating material cartridges 36a, 36b, 36c, 36d Cylinder bore wall heat insulating tools 37, 37a, 331a, 331b, 332a, 332b, 332c, 332d Bent part 38 Cooling water flow partition member 39 Metal leaf spring 40c, 40d, 40e, 40f, 40g Joint part 43 Metal plate 45 Metal plate punched part 191 Bore space 192 Groove shape Boundary of bore wall of each cylinder bore on the wall surface on the cylinder bore side of the cooling water flow path 301 Opening 302a, 302b, 302c, 302d Convex part 401f Vertical part of the concave part of the divided body 411 Recessed part of the divided body 412 Convex part of the divided body

Claims (6)

It is a cylinder bore wall heat insulator that is installed in the groove-shaped cooling water flow path of the cylinder block of an internal combustion engine having a cylinder bore and keeps some of the bore walls of all cylinder bores warm.
It is made of an inflatable material, has a space portion in the center that serves as a cooling water holding portion after expansion, an outer edge is located outside the first opening of the front side backing plate, and an inner edge is the first opening of the front side backing plate. An expansion member having a shape located inside one opening and contacting the wall surface on the cylinder bore side of the groove-shaped cooling water flow path after expansion.
An elastic member provided on the back surface side of the expansion member and urging the expansion member so as to press the expansion member is attached, and the entire expansion member is directed from the back surface side toward the wall surface of the groove-shaped cooling water flow path on the cylinder bore side. And the back side pressing part for pressing
The front side backing plate provided on the contact surface side of the expansion member, having the first opening inside, and sandwiching the outer edge side of the expansion member with the back side pressing member.
One or more fixing portions for integrally fixing the expansion member, the back side pressing portion, and the front side backing plate,
To have
Cylinder bore wall warming device featuring. The heat insulating device for a cylinder bore wall according to claim 1, wherein the expansion member is composed of two or more divided bodies, and the shape of the outer edge and the shape of the inner edge of the expansion member are rectangular. A claim having one or more beads provided on the front side backing plate at a position separated from the one or more fixing portions, protruding toward the expansion member, and sandwiching the covering member with the back side pressing member. The heat insulating device for the cylinder bore wall according to 1. A claim having one or more beads provided on the back surface pressing member at a position separated from the one or more fixing portions, projecting toward the expanding member, and sandwiching the covering member with the front surface backing plate. The heat insulating device for the cylinder bore wall according to 1. An internal combustion engine having a heat insulating device for a cylinder bore wall according to any one of claims 1 to 4. An automobile having an internal combustion engine according to claim 5.

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