JP6974837B2 - Spacer - Google Patents

Description

The present invention relates to a spacer arranged in a cooling water flow path formed in a cylinder block of an internal combustion engine so as to surround a cylinder bore.

In the cooling water flow path of the internal combustion engine, a spacer for regulating the flow (flow rate, flow velocity, etc.) of the circulating cooling water is inserted and arranged from the opening (see, for example, Patent Documents 1 to 3). In the spacers (regulatory members) disclosed in Patent Documents 1 to 3, the side surface of the spacer body (support, substrate) made of synthetic resin or the like on the cylinder bore side becomes enormous when it comes into contact with cooling water, and the cooling water flow path becomes enormous. A member that comes into contact with the wall surface on the cylinder bore side of the above is attached. Since the member attached to the spacer body in this way is bulky (thin) before it becomes enormous, when inserting the spacer into the cooling water flow path, the insertion resistance is reduced to facilitate the insertion. After arranging it in the cooling water flow path, it will be enormous and the flow of cooling water will be regulated.

Japanese Unexamined Patent Publication No. 2012-7478 Japanese Unexamined Patent Publication No. 2016-156277 Japanese Unexamined Patent Publication No. 2017-115613

By the way, the enormous member as described above comes into contact with the wall surface on the cylinder bore side due to the enormous growth, but it is difficult to adjust the degree of contact, and it is inevitable that the entire front surface comes into contact with the wall surface. .. Therefore, the flow of the cooling water is blocked by the member, and the cooling property of the cylinder bore wall at the contact portion is also lowered.

Further, since the enormous member as described above is attached to the surface of the spacer body on the cylinder bore side, the mounting surface side is restricted by the spacer body when enormous, so that the radius of curvature is small on the surface side. A force that tries to contract in the circumferential direction acts. As a result, concave (convex) wrinkles are randomly generated on the surface as the volume increases. The principle of this wrinkle generation will be schematically described with reference to FIGS. 8 (a) and 8 (b). 8 (a) and 8 (b) show a part of the cylinder block of the internal combustion engine (see FIG. 1 for the whole). In the cylinder block 100 of the illustrated example, a cooling water flow path 102 is formed so as to surround the cylinder bore 101, and a spacer 103 is arranged in the cooling water flow path 102. The spacer 103 includes a spacer main body 104 made of a molded resin body, and a porous body 105 attached to the side surface 104a of the spacer main body 104 on the cylinder bore 101 side. The porous body 105 of the example is made of a sheet-shaped cellulosic sponge as exemplified in Patent Documents 2 and 3. FIG. 8A shows a state in which the porous body 105 is maintained in a compressed state, and FIG. 8B shows a state in which the porous body 105 is restored to a state before compression by contacting with cooling water (enlarged). The states in which the cooling water flow path 102 is in contact with the inner wall surface 102a on the cylinder bore 101 side are shown. In the process of restoration of the porous body 105, a force that tends to contract in the circumferential direction so that the radius of curvature becomes smaller acts on the surface 105a side of the porous body 105, and a plurality of wrinkles 105b are randomly generated on the surface 105a. do. As described above, when a plurality of wrinkles 105b are randomly generated, the portion of the wrinkles 105b becomes a flow passage for cooling water, and the supercooling suppressing function of the cylinder bore wall 101a by the porous body 105 becomes unstable.

The present invention has been made in view of the above, and an object of the present invention is to provide a spacer capable of appropriately adjusting the cooling function by cooling water and the supercooling suppressing function by a porous body.

The spacer according to the present invention is a spacer arranged in a cooling water flow path formed in a cylinder block of an internal combustion engine so as to surround the cylinder bore, and includes a spacer main body including an arc portion having a shape corresponding to the cylinder bore, and the spacer body. A porous body attached to the side surface of the spacer body on the cylinder bore side and expanding in the width direction of the cooling water flow path when a predetermined external factor is added, and an arc portion of the spacer body. Is provided with a recess having a shape of being recessed on the side opposite to the cylinder bore, and the porous body is on the side opposite to the cylinder bore so as to imitate the recess in the portion corresponding to the recess of the spacer body. It is characterized by including a concave portion having a concave shape.

According to the spacer of the present invention, since the porous body includes a recess recessed on the side opposite to the cylinder bore, the curvature on the surface side thereof when the volume increases in the width direction of the cooling water flow path due to the addition of a predetermined external factor. The force that tends to contract so that the radius becomes smaller is absorbed by the recess. Therefore, it is possible to suppress the occurrence of wrinkles in the portion other than the concave portion, and it is possible to stabilize the supercooling suppressing function by the porous body. Further, by setting the concave portion at an appropriate place, the region where the cooling water is blocked by the porous body can be reduced, whereby the cooling performance by the cooling water can be finely adjusted.

In the spacer according to the present invention, the recess is formed to have a length extending in the depth direction of the cooling water flow path and not reaching both ends of the porous body in the depth direction of the cooling water flow path. May be good.
According to this, since the recess is formed to have a length that extends in the depth direction of the cooling water flow path but does not reach both ends in the depth direction, the cooling water flows along the depth direction through the recess. It can suppress the flow. This makes it possible to prevent the porous body from deteriorating the supercooling suppressing function of the cylinder bore wall.

In the spacer according to the present invention, the recess may be formed to have a length extending in the depth direction of the cooling water flow path and reaching both ends of the porous body in the depth direction of the cooling water flow path. good.
According to this, since the recess is formed to have a length extending in the depth direction of the cooling water flow path and reaching both ends in the depth direction, the cooling water flows along the depth direction through the recess. Can promote that. Therefore, by appropriately setting the number and position of the recesses, the cooling performance by the cooling water with respect to the cylinder bore wall in the depth direction and the circumferential direction of the cooling water flow path can be finely adjusted.
In this case, a drain hole for discharging the cooling water is provided on the wall surface of the cooling water flow path, and the recess extends from above the drain hole in the vertical direction so as to guide the cooling water to the drain hole. It may be shaped.
According to this, during normal operation of the internal combustion engine, the recess has the same function as described above, while when the cooling water is discharged from the drain hole when the cooling water is replaced, the cooling water drains along the recess. Since the guide is smoothly directed toward, the discharge of cooling water can be improved.

In the spacer according to the present invention, the recess may be formed to have a length extending in the circumferential direction of the cooling water flow path and reaching both ends of the porous body in the circumferential direction of the cooling water flow path.
According to this, since the recess extends in the circumferential direction of the cooling water flow path and is formed to have a length reaching both ends in the circumferential direction of the porous body, the inner wall surface of the cooling water flow path on the cylinder bore side and the porous body are formed. A cooling water flow path along the circumferential direction is formed between them. Therefore, by appropriately setting the number and position of the recesses, the cooling performance by the cooling water with respect to the cylinder bore wall in the depth direction and the circumferential direction of the cooling water flow path can be finely adjusted.

According to the spacer according to the present invention, the cooling function by the cooling water and the supercooling suppressing function by the porous body can be appropriately adjusted.

It is a schematic cross-sectional plan view which shows an example of the state which the spacer which concerns on this invention is arranged in the cooling water flow path of an internal combustion engine. The first embodiment of the spacer which concerns on this invention is shown, and (a) is an enlarged view of the X part of FIG. (B) is the same figure as (a) showing a state in which the cooling water comes into contact with the porous body from the state of (a) and the porous body becomes enormous. It is a development view seen from the Y direction in FIG. 2 (a). A second embodiment of the spacer according to the present invention is shown, and is a developed view seen from the direction corresponding to the Y direction in FIG. 2A. A third embodiment of the spacer according to the present invention is shown, and FIG. 1A is an enlarged view of a portion corresponding to a portion X in FIG. (B) is the same figure as (a) showing a state in which the cooling water comes into contact with the porous body from the state of (a) and the porous body becomes enormous. A fourth embodiment of the spacer according to the present invention is shown, and FIG. 1A is an enlarged view of a portion corresponding to a portion X in FIG. (B) is the same figure as (a) showing a state in which the cooling water comes into contact with the porous body from the state of (a) and the porous body becomes enormous. A fifth embodiment of the spacer according to the present invention is shown, and FIG. 2A is a development view seen from a direction corresponding to the Y direction of FIG. (B) is a cross-sectional view taken along the line ZZ of (a), and (c) shows a state in which the cooling water comes into contact with the porous body from the state of (b) and the porous body becomes enormous (). It is the same figure as b). (A) and (b) are diagrams for explaining the principle of wrinkle generation of a porous body in a conventional spacer.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 7. 1 to 3 show a first embodiment of the spacer according to the present invention, and FIG. 1 shows a state in which the spacer of the same embodiment is arranged in the cooling water flow path 3 of the cylinder block 1 in the internal combustion engine 10. Shows. The cylinder block 1 shown in FIG. 1 constitutes a three-cylinder automobile engine (internal combustion engine) 10, and is provided so that three cylinder bores (cylinders) 2 ... Are connected in series in an adjacent state. 1a ... Is an insertion hole for a bolt (not shown) for uniting and fastening the cylinder head (not shown) to the cylinder block 1 via a head gasket (not shown). Around the three cylinder bores 2 ... Is formed in a series of open deck type groove-shaped cooling water flow paths 3 so as to surround these cylinder bores 2 ... A cooling water outlet 5 is provided. The cooling water outlet 5 is connected by a pipe to a radiator (not shown), and the outlet side of the radiator is piped to the cooling water introduction port 4 via a water pump (not shown). It is connected so that the cooling water (including the antifreeze liquid) circulates between the cooling water flow path 3 and the radiator. When the cylinder head is also provided with the cooling water flow path (not shown). Is configured so that the cooling water flow path 3 of the cylinder block 1 and the cooling water flow path of the cylinder head communicate with each other. In this case, the cylinder block 1 may not have the cooling water outlet, and the cylinder head may not have the cooling water outlet. A cooling water outlet is provided at the site, and a pipe leading to the radiator is connected to this port.

The cooling water flow path 3 has an arc-shaped portion 3a formed so as to surround the cylinder bore 2 and a constricted portion 3b formed so as to be close to each other and form a pair with the adjacent cylinder bores 2 and 2. ing. The groove width of the constricted portion 3b ... Is larger than the groove width of the other arc-shaped portion 3a of the cooling water flow path 3. Both inner wall surfaces of the cooling water flow path 3 are formed so as to correspond to the arc-shaped portion 3a ... And the constricted-shaped portion 3b, and the inner wall surface (inner inner wall surface) 3c on the cylinder bore 2 side and the side opposite to the cylinder bore 2 It is composed of the inner wall surface (outer inner wall surface) 3d of the above. A piston (not shown) that reciprocates along its axial direction is provided in each cylinder bore 2, and the piston is placed on the inner circumference of the cylinder bore wall 2a via a piston ring (not shown) attached to the outer peripheral portion thereof. It is configured so that the surface 2aa can be slidably contacted. The circumferential direction c of the cooling water flow path 3 in the present embodiment is a direction based on the ring shape surrounding the cylinder bore 2 ... in a plan view of the cylinder bore 2 ... The depth direction (vertical direction) b of the cooling water flow path 3 is orthogonal to the circumferential direction c of the cooling water flow path 3 and is a direction parallel to the central axis of each cylinder bore 2 ... (See FIG. 3).

A spacer 6 is arranged in the cooling water flow path 3. The spacer 6 of the present embodiment is attached to the spacer main body 7 including the arc portion 7a having a shape corresponding to the cylinder bore 2 ... And the side surface 70 of the spacer main body 7 on the cylinder bore 2 side, and a predetermined external factor is added. A porous body 8 that becomes enormous in the width direction a of the cooling water flow path 3 is provided. Further, the arc portion 7a of the spacer main body 7 is provided with a recess 71 having a shape recessed on the side surface 70 on the cylinder bore 2 side opposite to the cylinder bore 2. The porous body 8 includes a recess 81 having a shape recessed on the opposite side of the cylinder bore 2 so as to imitate the recess 71 in the portion of the spacer body 7 corresponding to the recess 71. The recess 71 is formed so that the width of the cooling water flow path 3 along the circumferential direction c is at least twice the thickness of the compressed porous body 8. Further, the recess 71 is formed so that the width of the cooling water flow path 3 along the width direction a is equal to or larger than the thickness of the compressed porous body 8.

The spacer main body 7 of the spacer 6 in the present embodiment is made of a resin molded body, and has a semi-cylindrical shape arranged in a cooling water flow path 3 located on one side of a center line along a continuous direction of three cylinder bores 2 ... It is formed in a (half-split) shape. The spacer main body 7 of the present embodiment has three arc portions 7a ... located in the arc-shaped portion 3a of the cooling water flow path 3, and arc portions 7a located adjacent to the constricted shaped portions 3b and 3b of the cooling water flow path 3. It has two bent portions 7b and 7b connecting the 7a. Then, in each arc portion 7a, three recesses 71 having a rectangular cross section arranged at substantially equal intervals along the circumferential direction c are formed in the upper and lower end portions 70a and 70b of the spacer body 7 in the depth direction b. It is formed to a length that does not reach.

The porous body 8 of the spacer 6 in the present embodiment is made of a cellulosic sponge in a compressed state, and the cellulosic sponge is maintained in a compressed state, and when it comes into contact with water, this becomes an external factor, which is an opportunity. It has the property of restoring to the state before compression. More specifically, the cellulosic sponge is a natural material composed of pulp-derived cellulose and natural fibers (for example, cotton) added as reinforcing fibers. Cellulose has a hydrophilic group (OH) and has a property of being chemically compatible with water. In addition, the cellulose-based sponge is a porous material, and when it is dried under pressure, hydrogen bonds between the cellulose molecules are maintained in a compressed state, while when exposed to water from this state, the water molecules become cellulose. It has the property of dissociating hydrogen bonds between molecules and restoring them from a compressed state. The cellulosic sponge (porous body 8) is integrated with the spacer body 7 by insert molding the compressed cellulose sponge together with the spacer body 7. Therefore, the cellulosic sponge is fixed to the side surface 70 on the cylinder bore 2 side of the spacer body 7 in a state where a part of the resin material constituting the spacer body 7 is impregnated into the cellulose sponge. The recess 81 of the porous body 8 is recessed from the side surface 80 on the cylinder bore 2 side to the side opposite to the cylinder bore 2 in the portion corresponding to the recess 71 of the spacer body 7, and the insert molding is performed so as to imitate the recess 71. Sometimes it is shaped into a square cross section. The recess 81 of the porous body 8 in the present embodiment has a length that extends in the depth direction b of the cooling water flow path 3 but does not reach the upper and lower ends 80a and 80b of the porous body 8 in the depth direction b. It is formed in (a length shorter than the width along the depth direction b of the porous body 8).

The spacer 6 configured as described above is inserted and arranged in the cooling water flow path 3 in the internal combustion engine 10 from the opening 30 (see FIGS. 7 (b) and 7 (c)). 1 and 2 (a) show a state in which the spacer 6 is arranged in the cooling water flow path 3. When the spacer 6 is arranged in the cooling water flow path 3, the porous body 8 is maintained in a compressed state, so that the porous body 8 does not easily interfere with the inner inner wall portion 3c of the cooling water flow path 3 and is smoothly inserted. Will be done. Next, a cylinder head is fastened and integrated on the upper surface of the cylinder block 1 via a head gasket, and then cooling water is introduced into the cooling water flow path 3 from the cooling water introduction port 4. Then, due to the explosive action of the combustion gas in the combustion chamber of the cylinder head, the piston in the cylinder bore 2 repeatedly moves up and down, and the internal combustion engine 10 is put into operation.

As described above, when the cooling water is introduced into the cooling water flow path 3, the cooling water comes into contact with the porous body 8 made of a cellulosic sponge, the porous body 8 is restored, and the cylinder bore 2 side (anti-compression direction). ) Will be enormous. Along with this restoration, the surface (side surface on the cylinder bore 2 side) 80 of the porous body 8 comes into contact with the inner inner wall surface (wall surface on the cylinder bore 2 side) 3c of the cooling water flow path 3. FIG. 2B shows a state in which the porous body 8 is enormous. The porous body 8 is provided at a position where the cooling capacity of the cooling water flowing through the cooling water flow path 3 is excessive with respect to the cylinder bore wall 2a, and when the porous body 8 becomes enormous, the porous body 8 becomes the cooling water. Block the flow. Then, the porous body 8 comes to reduce the cooling capacity of the cooling water with respect to the cylinder bore wall 2a, exerts a supercooling suppressing function, and appropriately adjusts the cooling state with respect to the cylinder bore wall 2a. At the time of enlarging due to the restoration of the porous body 8, a force that tends to contract in the circumferential direction c acts on the surface 80 side of the porous body 8 so that the radius of curvature becomes smaller, and this force acts on the surface 80 side of the porous body 8. It is absorbed by the recess 81 provided on the surface 80 side of the surface. That is, the wrinkles generated when the porous body 8 becomes enormous are concentrated on the concave portion 81 side. Therefore, it is possible to suppress the occurrence of wrinkles in the portion other than the recess 81, and it is possible to stabilize the supercooling suppressing function by the porous body 8. Further, when the porous body 8 is enlarged, the porous body 8 in the concave portion 81 is restored in a direction other than the anti-compression direction because the shape of the porous body 8 is different from the portion other than the concave portion 81. Therefore, the recess 81 remains in a deformed state from the original shape as shown in FIG. 2 (b). Therefore, by setting the recess 81 at an appropriate position, the region where the cooling water is blocked by the porous body 8 can be reduced, whereby the cooling performance by the cooling water can be finely adjusted. Further, in the present embodiment, the recess 81 is formed to have a length extending in the depth direction b of the cooling water flow path 3 but not reaching the upper and lower ends 80a and 80b in the depth direction b of the porous body 8. Therefore, the cooling water tends to stay in the recess 81. Therefore, it is possible to prevent the cooling water from flowing along the depth direction b through the recess 81. As a result, it is possible to suppress the generation of wrinkles in the porous body 8 and prevent the supercooling suppressing function of the porous body 8 from being excessively lowered.

FIG. 4 shows a second embodiment of the spacer according to the present invention. In the spacer 6 of the present embodiment, the recess 81 provided in the porous body 8 extends in the depth direction b and is formed to have a length reaching the upper and lower end portions 80a and 80b in the depth direction b of the porous body 8. Has been done. Further, the recess 71 provided in the spacer main body 7 extends in the depth direction b of the spacer main body 7 and is formed to have a length reaching the upper and lower end portions 80a and 80b in the depth direction b of the spacer main body 7. .. Further, in the present embodiment, a drain hole 5a leading to the outside of the cylinder block 1 is provided at a position near the bottom wall surface 3e of the outer inner wall surface 3d in the cooling water flow path 3. The lower end of the central recess 71 among the three recesses 71 in the spacer body 7 is positioned so as to substantially correspond to the drain hole 5a. Then, the recess 81 provided in the porous body 8 so as to follow the central recess 71 provided in the spacer main body 7 extends from the upper side in the vertical direction with respect to the drain hole 5a so as to guide the cooling water to the drain hole 5a. It is said to be in shape. The drain hole 5a may be provided on the bottom wall surface 3e of the cooling water flow path 3 so as to lead to the outside of the cylinder block 1. The depth direction b of the cooling water flow path 3 in all the embodiments does not necessarily correspond to the vertical direction.

In the present embodiment, the recess 81 suppresses the generation of wrinkles in the porous body 8 in the same manner as described above. In addition, since the recess 81 extends in the depth direction b of the cooling water flow path 3 and is formed to have a length reaching the upper and lower end portions 80a and 80b in the depth direction b, the recess 81 is formed in the depth direction through the recess 81. It is possible to promote the flow of cooling water along b. In particular, even after the porous body 8 becomes enormous, a deformed recess 81 communicating between the upper and lower end portions 80a and 80b of the porous body 8 remains between the cylinder bore wall 2a and the porous body 8, so that the recess 81 remains. The 81 constitutes a cooling water flow path along the depth direction b. Therefore, by appropriately setting the number and position of the recesses 81, it becomes possible to finely adjust the cooling performance of the cylinder bore wall 2a in the depth direction b and the circumferential direction c of the cooling water flow path 3 by the cooling water.
Further, in the present embodiment, the drain hole 5a for the cooling water is provided on the outer inner wall surface 3d near the bottom wall surface 3e in the cooling water flow path 3, and when the cooling water in the cooling water flow path 3 is exchanged, the drain hole 5a is provided. , Cooling water is discharged by opening the plug (not shown) of the drain hole 5a. At this time, the cooling water is smoothly guided from the upper side in the vertical direction toward the drain hole 5a along the central recess 81 in the circumferential direction c of the porous body 8, so that the dischargeability of the cooling water is improved. Can be done.
The recess 81 corresponding to the drain hole 5a is not limited to the recess 81 in the central portion, but may be a recess 81 in another portion, and the position of the corresponding recess 81 is appropriately set according to the specifications of the cylinder block 1. NS.

5 (a) and 5 (b) show a third embodiment of the spacer according to the present invention. In the spacer 6 of the present embodiment, the recess 71 provided in the spacer main body 7 and the recess 81 provided in the porous body 8 have the depth of the cooling water flow path 3 as in the first embodiment or the second embodiment. It is formed so as to extend in the direction b. However, the spacer body 6 of the present embodiment is the first embodiment in that the cross-sectional shape of the recess 71 is substantially triangular and the cross-sectional shape of the recess 81 of the porous body 8 is substantially triangular following the recess 71. Alternatively, it is different from the second embodiment. Then, as shown in FIG. 5B, the recess 81 after the enlargement of the porous body 8 is deformed from the original triangular cross section, but is different from the first embodiment or the second embodiment. It remains in the cross-sectional shape. As a result, it is possible to secure a cooling water flow path between the recess 81 and the inner inner wall surface 3c of the cooling water flow path 3 as in the first embodiment or the second embodiment. This makes it possible to finely adjust the cooling performance of the cooling water.
Since the other configurations are the same as those of the first embodiment or the second embodiment, the same reference numerals are given to the common parts and the description thereof will be omitted.

6 (a) and 6 (b) show the fourth embodiment of the spacer which concerns on this invention. In the spacer 6 of the present embodiment, one recess 71 is provided in the spacer main body 7 so as to extend in the depth direction b of the cooling water flow path 3. However, the recess 71 has a substantially symmetrical two-stage shape in which the central portion of the cooling water flow path 3 in the circumferential direction c is deeply recessed on the side opposite to the cylinder bore 2. The recess 81 provided in the porous body 8 also has a two-stage shape that is recessed so as to follow the recess 71 of the spacer body 7. Then, as shown in FIG. 6B, the recess 81 after the enlargement of the porous body 8 is deformed from the original two-stage cross section, but has a cross section different from that of the first to third embodiments. It remains in shape and has a large cross-sectional area. As a result, it is possible to secure a cooling water flow path between the recess 81 and the inner inner wall surface 3c of the cooling water flow path 3 as in the first to third embodiments. As a result, the cooling performance by the cooling water can be finely adjusted in consideration of the large cross-sectional area of the cooling water flow passage due to the recess 81.
The number of such recesses 71 and 81 is not limited to one, and a plurality of such recesses 71 and 81 may be provided as in the above embodiment. Since the other configurations are the same as those of the first to third embodiments, the same reference numerals are given to the common parts and the description thereof will be omitted.

7 (a), (b) and (c) show a fifth embodiment of the spacer according to the present invention. In the spacer 6 of the present embodiment, a plurality of (three in the example) recesses 71 ... Extending in the circumferential direction c of the cooling water flow path 3 are opposite to the cylinder bore 2 on the side surface 70 of the spacer main body 7 on the cylinder bore 2 side. It is provided so as to be recessed on the side. The plurality of recesses 71 ... Have a rectangular cross section, and are provided parallel to the depth direction b of the cooling water flow path 3 and at equal intervals. Further, the same porous body 8 as described above is attached to the side surface 70 of the spacer main body 7 on the cylinder bore 2 side. The side surface 80 on the cylinder bore 2 side of the porous body 8 is provided with a plurality of (three in the example) recesses 81 having a shape recessed on the opposite side to the cylinder bore 2 so as to follow the recess 71. .. In the present embodiment, each of the plurality of recesses 81 ... Is formed to have a length reaching both ends 80c and 80d in the circumferential direction c of the porous body 8.

Also in this embodiment, when the cooling water is supplied to the cooling water flow path 3, the porous body 8 is restored and becomes enormous toward the cylinder bore 2 along the width direction a of the cooling water flow path 3. Then, the side surface (surface) 80 of the porous body 8 on the cylinder bore 2 side comes into contact with the inner inner wall surface 3c of the cooling water flow path 3. At this time, the recesses 81 ... Of the porous body 8 remain in a deformed state, and both ends 80c of the porous body 8 in the circumferential direction c due to the recesses 81 ... Between the porous body 8 and the inner inner wall surface 3c, A cooling water flow path leading to 80d is formed. Therefore, by appropriately setting the number and position of the recesses 81, the cooling performance by the cooling water with respect to the cylinder bore wall 2a in the depth direction b and the circumferential direction c of the cooling water flow path can be finely adjusted.
Since the other configurations are the same as those of the above-described embodiments, the same reference numerals are given to the common portions, and the description thereof will be omitted.

The number, shape, or position of the recesses 71 provided in the spacer body 7 and the recesses 81 provided in the porous body 8 are not limited to those exemplified, and wrinkle generation suppressing functions, cooling performance, and the like are further required. It is set appropriately according to the specifications. For example, the recess 71 and the recess 81 extending in the depth direction b of the cooling water flow path 3 shown in the second embodiment and the recess 71 extending in the circumferential direction c of the cooling water flow path 3 shown in the fifth embodiment. The recess 81 may be provided respectively. Further, the recess 71 and the recess 81 are exemplified along the depth direction b or the circumferential direction c, but are not limited to this, and may be inclined with respect to the depth direction b or the circumferential direction c, and further. Is not limited to continuous ones, but may be intermittent ones. Further, in the second embodiment, the positional relationship between the drain hole 5a provided in the cooling water flow path 3 and the recess 81 is defined, but when the drain hole 5a is present in the cooling water flow path 3, in another embodiment. The positional relationship between the drain hole 5a and the recess 81 may be similarly defined.

In addition to the cellulosic sponge, the material constituting the porous body 8 is a water-swellable sponge, a water-soluble binder, or a foam maintained in a compressed state by a binder that dissolves at a temperature equal to or higher than a predetermined temperature. It may be made of a non-foaming porous body.
Further, examples of the cellulosic sponge include various types, but the sponge is not particularly limited. For example, any of a fine particle product having a very small bubble size, a small particle product having a small bubble size, and a medium grain product having a medium bubble size may be used. Specifically, a cellulosic sponge having a bubble size (diameter) of about 0.1 to 5 mm may be used. The size of these bubbles is determined by the particle size of the crystalline niter used in the process of producing the cellulosic sponge. Further, the cellulosic sponge is preferably composed of cellulose and reinforcing fibers, but is not limited to this, and may be composed of cellulose alone. The cellulosic sponge is not only a sponge made of cellulose itself, but also a cellulosic derivative having a cellulosic hydroxyl group remaining to the extent that it can maintain a compressed state, for example, a sponge made of cellulose ethers, cellulose esters, or the like, or a sponge. It may be selected from any of the sponges composed of these mixtures.
Further, the porous body 8 is not limited to insert molding, and may be integrated with the support 7 by mechanically fixing with an adhesive or an appropriate jig.

In addition, the example in which the spacer body 7 is made of a molded body of synthetic resin has been described, but if the spacer body 7 is more rigid than the material constituting the porous body 8, such as metal, it may be made of another material. good. Further, the position where the porous body 8 is fixed to the spacer main body 7 (the position in the depth direction b of the cooling water flow path 3 and the position in the circumferential direction c) and the number of the porous bodies 8 (the depth of the cooling water flow path 3). The number of directions b and the number of circumferential directions c) are appropriately changed according to the required specifications such as the stability of the spacer 6 in the cooling water flow path 3 or the cooling function of the cooling water flowing in the cooling water flow path 3. You may. For example, in the above-described embodiment, the porous body 8 is provided for each arc portion 7a of the spacer main body 7, but a strip-shaped porous body corresponding to all (plural) arc portions 7a of the spacer main body 7. 8 may be attached to the spacer body 7. Further, although the shape of the spacer main body 7 is exemplified as a semi-cylindrical shape (half-split shape) in the embodiment, it may be a full-cylindrical shape covering the entire circumference of the cooling water flow path 3. Alternatively, the shape of the spacer main body 7 may form a partial spacer smaller than a half-split shape as long as it includes an arc portion corresponding to the cylinder bore 2. In the case of such a partial spacer, a plurality of such partial spacers may be arranged in the cooling water flow path 3, and the number of the partial spacers to be arranged may be appropriately set according to the space in the cooling water flow path 3, the required specifications, and the like. good.
Furthermore, although a three-cylinder internal combustion engine is exemplified as an internal combustion engine to which the spacer of the present invention is applied, the present invention is not limited to this and can be applied to an internal combustion engine having another number of cylinders.

10 Internal combustion engine 1 Cylinder block 2 Cylinder bore 3 Cooling water flow path 5a Drain hole 6 Spacer 7 Spacer body 7a Arc part 70 Cylinder bore side side surface 71 Recess 8 Porous body 81 Recess 80a, 80b Both ends 80c, 80d circumference in the depth direction Both ends in the direction a Width direction b Depth direction c Circumferential direction

Claims (5)

A spacer placed in a cooling water flow path formed in a cylinder block of an internal combustion engine so as to surround a cylinder bore.
A spacer body including an arc portion having a shape corresponding to the cylinder bore, and
It is provided with a porous body attached to the side surface of the spacer body on the cylinder bore side and expanding in the width direction of the cooling water flow path when a predetermined external factor is added.
The arc portion of the spacer body is provided with a recess having a shape recessed on the side opposite to the cylinder bore.
The porous body is characterized in that the portion corresponding to the recess of the spacer body includes a recess having a shape recessed on the opposite side of the cylinder bore so as to imitate the recess. In the spacer according to claim 1,
The spacer is characterized in that the recess extends in the depth direction of the cooling water flow path and is formed to a length that does not reach both ends of the porous body in the depth direction of the cooling water flow path. In the spacer according to claim 1,
The spacer is characterized in that the recess extends in the depth direction of the cooling water flow path and is formed to have a length reaching both ends of the porous body in the depth direction of the cooling water flow path. In the spacer according to claim 3,
A drain hole for discharging the cooling water is provided on the wall surface of the cooling water flow path.
The recess is a spacer characterized in that the concave portion extends from the upper side in the vertical direction with respect to the drain hole so as to guide the cooling water to the drain hole. In the spacer according to claim 1,
The spacer is characterized in that the recess extends in the circumferential direction of the cooling water flow path and is formed to have a length reaching both ends of the porous body in the circumferential direction of the cooling water flow path.

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