JP7705653B2 - Spacer and manufacturing method thereof - Google Patents

Description

The present invention relates to a spacer that is placed in a concave cooling water flow passage formed in a cylinder block of an internal combustion engine so as to surround the cylinder bore, and a method for manufacturing the same.

Examples of the above-mentioned spacer include Patent Documents 1 and 2 below. The spacers disclosed in Patent Documents 1 and 2 below have a porous body attached to the cylinder bore side surface of a molded body made of a resin material, which expands when it comes into contact with cooling water and comes into contact with the wall surface of the cylinder bore side of the cooling water flow path. The porous body attached to the molded body in this way has a thin thickness before it expands, so when the spacer is inserted into the cooling water flow path, the insertion resistance is small and it can be inserted smoothly, and after being placed in the cooling water flow path, it expands and can regulate the flow (flow rate, flow speed, etc.) of the cooling water.

JP 2020-122479 A JP 2021-080854 A

The above-mentioned spacer is manufactured by injection molding a resin material after placing the porous body in a predetermined position in the mold. At this time, when the end face of the porous body is impregnated with the resin material, even if a predetermined external factor is applied to the porous body, the porous body will grow in a kamaboko shape with a curved end face when viewed in cross section, and the desired thickness may not be achieved near the end face. In particular, in the vicinity of the positioning protrusion for positioning the porous body, a gap is likely to be formed between the porous body and the positioning protrusion due to the variation in the dimensions of the porous body and the positioning protrusion, and the resin material is likely to enter the end face of the porous body. For this reason, even if a predetermined external factor is applied as designed, the porous body may not grow to the desired thickness near the end face, and the flow of cooling water may not be regulated as specified. Furthermore, since the porous body grows in a kamaboko shape as described above, a certain distance is required from the end face to grow to a sufficient thickness, and the desired thickness may not be achieved in the area where the distance between the opposing end faces of the porous body is close.

The present invention was made in consideration of the above circumstances, and aims to provide a spacer and a manufacturing method thereof that can adjust the thickness of the porous body to a desired thickness and regulate the flow of cooling water through the cooling water flow path.

In order to achieve the above object, the spacer of the present invention is a spacer that is disposed in a cooling water flow path provided in a cylinder block of an internal combustion engine and regulates the flow of cooling water, and is characterized in that it comprises a molded body made of a resin material, a first porous body provided on one side of the molded body and having a through hole, a second porous body provided on the one side, and a concave recessed portion formed inside the through hole on the one side, the first porous body and the second porous body are partially impregnated with the resin material and molded integrally with the molded body, and have a characteristic that the thickness in the thickness direction increases when a predetermined external factor is applied, and the second porous body has an overlapping portion that overlaps a portion of the first porous body and the formation position of the recessed portion in the depth direction of the cooling water flow path.

In order to achieve the above object, according to another spacer of the present invention, a spacer is disposed in a cooling water flow path provided in a cylinder block of an internal combustion engine and regulates the flow of cooling water, comprising a molded body made of a resin material, a first porous body provided on one side of the molded body, a second porous body provided on the one side, and a concave recessed portion formed on the peripheral portion of the first porous body on the one side, the first porous body and the second porous body being partially impregnated with the resin material and molded integrally with the molded body, and having a characteristic that the thickness in the thickness direction increases when a predetermined external factor is applied, and the second porous body has a part that overlaps with a part of the first porous body and has an overlapping portion that overlaps the formation position of the recessed portion in the depth direction of the cooling water flow path.

In order to achieve the above object, the manufacturing method of the spacer of the present invention is a manufacturing method of a spacer that includes a molded body made of a resin material and a plurality of porous bodies that have a characteristic of increasing in thickness in the thickness direction when a predetermined external factor is applied, and is arranged in a cooling water flow path provided in a cylinder block of an internal combustion engine to regulate the flow of cooling water, and includes a first positioning step of positioning a first porous body among the plurality of porous bodies using a positioning protrusion provided in a molding die, a second positioning step of positioning a second porous body among the plurality of porous bodies on the first porous body, and a resin injection step of injecting the resin material into the cavity of the molding die after closing the die, and integrally molding the first porous body and the second porous body in a state in which the resin material is impregnated into a portion of the molded body, and the second positioning step is characterized in that a portion of the second porous body is overlapped with a portion of the first porous body and is positioned at a position that overlaps the formation position of the positioning protrusion and the depth direction of the cooling water flow path.

The spacer according to the present invention allows the thickness of the porous body to be adjusted to the desired thickness, and can regulate the flow of cooling water through the cooling water flow passage, particularly the flow in the depth direction of the cooling water flow passage.

In addition, the manufacturing method of the spacer according to the present invention allows the thickness of the porous body to be adjusted to the desired thickness, and a spacer can be obtained that can regulate the flow of cooling water passing through the cooling water flow passage, particularly the flow in the depth direction of the cooling water flow passage.

FIG. 1A is a schematic oblique view showing an example of a spacer according to a first embodiment of the present invention, FIG. 1B is an explanatory diagram for explaining a porous body provided in the spacer, and FIG. 1C is an explanatory diagram for explaining an overlapping portion of the porous body. 1A and 1B are partial cross-sectional views showing the overlapping portion when the spacer according to the embodiment is assembled in a cooling water flow path, where (a) shows the state before the porous body expands, and (b) shows the state after the porous body expands. 1A and 1B are partial longitudinal cross-sectional views showing the overlapping portion when the spacer according to the embodiment is assembled in a cooling water flow path, where (a) shows the state before the porous body expands, and (b) shows the state after the porous body expands. 2A to 2D are schematic cross-sectional views taken along the arrows of respective parts of the spacer shown in FIG. 1A in a state where the spacer is assembled in a cooling water flow path and the porous body is expanded. 11 is a flowchart illustrating an example of a method for manufacturing a spacer according to the embodiment. 1A to 1C are diagrams for explaining an example of a manufacturing method of a spacer according to the embodiment, and show schematic steps, in which (a) shows a first positioning step of arranging a first porous body in a mold, (b) shows a second positioning step of arranging a second porous body in the mold, and (c) shows a step of closing the mold and insert-molding the porous body and a resin material. 5A to 5C are diagrams for explaining modified examples of the spacer according to the same embodiment, and each diagram shows a schematic diagram of the positional relationship between the first porous body, the second porous body, and the positioning protrusion. 1A to 1C are diagrams for explaining a spacer according to a second embodiment of the present invention and its modified examples, and each diagram shows a schematic diagram of the positional relationship between a first porous body, a second porous body, and a positioning protrusion. 5A and 5B are diagrams for explaining modified examples of the spacer according to the same embodiment, and each diagram shows a schematic diagram of the positional relationship between the first porous body, the second porous body, and the positioning protrusion.

Hereinafter, the spacer according to the present embodiment will be described with reference to the drawings.
The spacer 10 according to this embodiment is disposed in a cooling water flow passage 3 provided in a cylinder block 1 of an internal combustion engine A in order to regulate the flow of cooling water. The spacer 10 includes a molded body 11 made of a resin material, a first porous body 12 provided on one side surface 11a of the molded body 11 and having a through hole 12c, and a second porous body 13 provided on the one side surface 11a. The spacer 10 also includes a concave recessed portion 14 formed inside the through hole 12c on the one side surface 11a. The first porous body 12 and the second porous body 13 are partially impregnated with the resin material and molded integrally with the molded body 11, and have a characteristic that the thickness in the thickness direction increases when a predetermined external factor is applied. The second porous body 13 has an overlapping portion 15 that overlaps a portion of the first porous body 12 and the formation position of the recessed portion 14 in the depth direction of the cooling water flow passage 3.
A detailed description will be given below. Note that some of the detailed reference numerals attached to some figures are omitted in other figures. In this specification, the flow direction and depth direction of each member are defined based on the state in which the spacer 10 is disposed in the cooling water flow path 3. In the depth direction of the cooling water flow path 3, the opening 3e side will be described as the upper side, and the opposite side will be described as the lower side. In the flow direction of the cooling water flow path 3, the right side on the paper of FIG. 1(a) will be described as one side, and the left side will be described as the other side.

First Embodiment
A spacer 10 according to the first embodiment will be described with reference to Figs. 1 to 7. Fig. 1(a) is a schematic perspective view showing the spacer 10, Fig. 1(b) is an explanatory view for explaining the first porous body 12 and the second porous body 13, and Fig. 1(c) is an explanatory view showing the positional relationship between the first porous body 12 and the second porous body 13. In Fig. 1(c), the overlapping portion of the first porous body 12 and the second porous body 13 is shown by hatching with oblique lines. Fig. 2(a) is an enlarged view corresponding to the cross-sectional view of the arrows X-X' in Fig. 1(a) in a state where the spacer 10 is disposed in the cooling water flow path 3, and Fig. 2(b) is a view showing a state where cooling water is supplied into the cooling water flow path 3 from the state shown in Fig. 2(a). Fig. 3(a) is a schematic vertical cross-sectional view of a position corresponding to the overlapping portion of the first porous body 12 and the second porous body 13 in Fig. 2(a), and Fig. 3(b) is a schematic vertical cross-sectional view of a position corresponding to the overlapping portion of the first porous body 12 and the second porous body 13 in Fig. 2(b). Fig. 4 is a cross-sectional view of the first porous body 12 and the second porous body 13 in Fig. 1(a) in an expanded state (the state shown in Fig. 3(b)), where (a) is a cross-sectional view taken along the line A-A', (b) is a cross-sectional view taken along the line B-B', (c) is a cross-sectional view taken along the line C-C', and (d) is a cross-sectional view taken along the line D-D'.

As shown in Figures 2 and 3, the spacer 10 is disposed in the cooling water flow path (water jacket) 3 of the cylinder block 1. A cylinder head 30 is disposed on the upper surface of the cylinder block 1, and an oil pan (not shown) is disposed on the lower surface of the cylinder block 1. The cylinder head 30 is integrally fastened to the cylinder block 1 so that the opening 3e of the cooling water flow path 3 is blocked, as shown in Figure 3 (b). The cylinder block 1 constitutes an internal combustion engine A having a plurality of cylinders, and a plurality of cylinder bores (cylinders) 2 are provided so as to be adjacent to each other and connected in series. Around the plurality of cylinder bores 2, an open deck type groove-shaped cooling water flow path 3 is formed in a series. In addition, a cooling water inlet (not shown) and a cooling water outlet (not shown) that communicate with the cooling water flow path 3 are provided at appropriate positions of the cylinder block 1. The cooling water outlet is connected to a radiator (not shown) by piping, and the outlet side of the radiator is connected to the cooling water inlet by piping via a water pump (not shown). This allows the coolant (including antifreeze) to circulate between the coolant flow path 3 and the radiator.

As shown in FIG. 3, a cylinder bore wall 20 is formed between the cylinder bore 2 and the cooling water flow path 3, and the two walls facing each other across the cooling water flow path 3 are composed of an inner wall surface 3c on the cylinder bore 2 side and an outer wall surface 3d on the opposite side to the cylinder bore 2. The cooling water flow path 3 is formed to efficiently cool the cylinder bore wall 20, and has a plurality of arc-shaped portions 3a formed to surround the cylinder bore 2 via the cylinder bore wall 20 as shown in FIG. 2, and a plurality of constricted portions 3b formed in pairs close to each other in the portion between the adjacent cylinder bores 2, 2. The groove width of the constricted portions 3b is larger than the groove width of the other arc-shaped portions 3a of the cooling water flow path 3.

<Spacer>
As shown in FIG. 1(a) and the like, the spacer 10 includes a molded body 11 made of a resin material, a first porous body 12, and a second porous body 13. The molded body 11 has a curved shape according to the shape of the cooling water flow path 3. Specifically, the molded body 11 has a plurality of arc portions 110 formed so as to surround a plurality of cylinder bores 2 via the cylinder bore wall 20, and a convex curved surface 111 formed between the arc portions 110 and the adjacent arc portions 110, and the convex curved surface 111 is disposed in a constricted shape portion 3b formed between the cylinder bore 2 and the adjacent cylinder bore 2 of the cooling water flow path 3. A cylindrical protrusion 112 is provided on the other side surface 11b of the molded body 11, and the protrusion 112 has a recess 14 formed therein, as shown in FIG. 3(a), FIG. 3(b), and FIG. 4(d). As shown in Fig. 3(a), Fig. 3(b) and Fig. 4(d), the protrusion 112 has a recess 14 formed therein. The tip of the protrusion 112 abuts against the outer wall surface 3d when the first porous body 12 and the second porous body 13 increase in thickness in the cooling water flow path 3 due to the addition of a predetermined external factor, so that the tip surface has a shape that conforms to the shape of the outer wall surface 3d. The protrusion 112 is formed by solidifying the resin material r that flows between the outer peripheral surface of the positioning protrusion 212 and the second cavity surface 221 of the second mold 220 during the manufacture of the spacer 10 described later. Therefore, a cavity is formed inside the protrusion 112 (at the position where the positioning protrusion 212 was arranged), and the cavity is configured as the recess 14. In addition, the recess 14 may be formed containing resin material r that flows and solidifies between the outer surface of the positioning protrusion 212 inserted into the through hole 12c of the first porous body 12 and the through hole 12c of the first porous body 12.

The first porous body 12 and the second porous body 13 are flexible sheets of approximately the same thickness, and have the property of increasing in thickness when a specific external factor is applied. The first porous body 12 is attached to one side 11a of the molded body 11, which includes a convex curved surface 111, specifically, to the cylinder bore 2 side. Therefore, the first porous body 12 is attached in a curved state along the convex curved surface 111, and is disposed in the constricted portion 3b, which is the portion formed between the cylinder bore 2 and the adjacent cylinder bore 2 of the cooling water flow path 3.

The first porous body 12 is a rectangular sheet body, and the dimension in the flow direction of the cooling water (longitudinal dimension) and the dimension in the depth direction of the cooling water flow path (shortitudinal dimension) are smaller than the dimension in the flow direction and the dimension in the depth direction of the second porous body 13. The first porous body 12 has two round through holes 12c arranged at a distance along the flow direction of the cooling water flow path 3. When viewed from above from the through hole 12c side, the inside of the through hole 12c has a recessed portion 14 formed in the protrusion 112 of the above-mentioned molded body 11. The first porous body 12 is impregnated with a resin material on the surface in contact with one side surface 11a of the molded body 11, the portion at the end portions 12b, 12b in the depth direction that does not overlap with the second porous body 13 in the thickness direction, and the edge of the through hole 12c, and is molded integrally with the molded body 11.

A plurality of second porous bodies 13 are provided with the first porous body 12 between them. In this embodiment, two second porous bodies 13, 13 are arranged so as to overlap the ends 12a, 12a on both sides of the flow direction of the first porous body 12 in the cooling water flow path 3. As shown in FIG. 1(b), the second porous body 13 has a concave portion 130 formed in a concave shape at the center of the depth direction of the end 13a in the flow direction located on the first porous body 12 side. When the second porous bodies 13, 13 are integrally molded with the molded body 11, the through hole 12c of the first porous body 12 is positioned in the concave portion 130 of the second porous body 13 (see FIG. 1(c)). As a result, the second porous body 13 has an overlapping portion 15 that overlaps a portion of the first porous body 12 and the formation position of the recessed portion 14 and the depth direction of the cooling water flow path 3. As shown in FIG. 1(c), the overlapping portion 15 is formed in a substantially inverted C-shape on one side in the flow direction when viewed from the side, and in a substantially C-shape on the other side in the flow direction, so as to sandwich the recessed portion 14 from both sides in the depth direction. The surface of the second porous body 13 that contacts one side surface 11a of the molded body 11 and the peripheral portion (ends 13a, 13a in the flow direction, ends 13b, 13b in the depth direction, and recessed portion 130) are impregnated with a resin material. The overlapping portion 15 of the second porous body 13 is provided between the molded body 11 and the first porous body 12, as shown in FIG. 2(a) and the like. Therefore, when the thicknesses of the first porous body 12 and the second porous body 13 increase in the thickness direction by the cooling water, the overlapping portion 15 of the second porous body 13 acts to push up the first porous body 12. Therefore, the combined thickness of the first porous body 12 and the second porous body 13 can be made to be a desired thickness. As shown in FIG. 3(a), the first porous body 12 and the second porous body 13 are configured to be flush with one side surface 11a of the molded body 11. Therefore, the overlapping portion 15 is configured to be located closer to the other side surface 11b than the first porous body 12.

The first porous body 12 and the second porous body 13 are not particularly limited as long as they have the property of increasing in thickness in the thickness direction when a certain external factor is added, but in this embodiment, a cellulose-based sponge is used. The cellulose-based sponge is made of a natural material consisting of cellulose derived from pulp and natural fibers (e.g., cotton, etc.) added as reinforcing fibers, and has an open-cell type and excellent water absorption. Here, cellulose has a hydrophilic group (OH) and is known to have a chemical property that is easily compatible with moisture. Therefore, when the cellulose-based sponge is dried under pressure, the cellulose molecules form hydrogen bonds to maintain the compressed state, while when it is exposed to moisture from this state, the water molecules dissociate the hydrogen bonds between the cellulose molecules and restore it from the compressed state. Therefore, the cellulose-based sponge is suitable as the first porous body 12 and the second porous body 13.

As shown in Figs. 2(a) and 3(a), the spacer 10 constructed as described above is easy to assemble in the cooling water flow path 3 because the first porous body 12 and the second porous body 13 are in a thin compressed state before being restored. When cooling water is supplied to the cooling water flow path 3, the first porous body 12 and the second porous body 13 come into contact with the cooling water, absorb the water, and expand, increasing their thickness in the thickness direction and becoming enlarged. As shown in Figs. 2(b) and 3(b), they come into contact with the inner wall surface 3c of the cooling water flow path 3, and can regulate the flow of the cooling water.

However, strictly speaking, as shown in Figures 3(b), 4(c), and 4(d), the edge and adjacent areas of the through hole 12c of the first porous body 12 are prevented from restoring due to the impregnated resin material, so they do not expand sufficiently and do not come into contact with the inner wall surface 3c of the cooling water flow path 3.

However, when the second porous body 13 expands, the overlapping portion 15 with the first porous body 12 pushes up the first porous body 12 arranged above, and the total amount of restoration can be set to the desired thickness, and the first porous body 12 contacts the inner wall surface 3c of the cooling water flow path 3. Therefore, the flow of the cooling water flowing through the cooling water flow path 3 can be regulated as designed. In addition, the portions of the first porous body 12 that overlap the second porous body 13 in the thickness direction at the ends 12a, 12a in the flow direction and the ends 12b, 12b in the depth direction are in contact with the molded body 11 made of a resin material via the second porous body 13, so that the resin material is not impregnated during manufacturing, and the first porous body 13 smoothly restores and expands easily.

In addition, in such a spacer, since the positioning protrusion 212 is inserted into the through hole 12c of the first porous body 12 to position it, it is inevitable that the resin material will be impregnated between the through hole 12c of the first porous body 12 and the positioning protrusion 212 during manufacturing. In addition, in the vicinity of the through hole 12c of the resin-impregnated porous body, it is difficult to restore to the desired thickness, and there is a risk that the porous body will not restore to the extent that it contacts the inner wall surface 3c. In that case, the cooling water may flow into the gap between the porous body and the inner wall surface 3c, and the cooling water may not be sufficiently regulated. Therefore, in this embodiment, a part of the second porous body 13 overlaps a part of the first porous body 12 and has an overlapping part 15 that overlaps the formation position of the recessed part 14 formed corresponding to the positioning protrusion 212 and the depth direction of the cooling water flow path 3. In this embodiment, a porous body is not arranged in the recessed part 14, but the overlapping part 15 is provided on both sides of the recessed part 14 in the depth direction. Therefore, when the thickness of the first porous body 12 and the second porous body 13 increases as a result of the supply of cooling water, the portions of the first porous body 12 that are difficult to restore can be compensated for by the overlapping portions 15 of the second porous body 13 to achieve the desired thickness, thereby regulating the flow rate and flow speed of the cooling water flowing through the cooling water flow passage 3, and in particular, regulating the flow of the cooling water up and down in the depth direction.

Furthermore, the molded body 11 of this embodiment has a convex curved surface 111 on one side 11a and is arranged in a portion formed between the cylinder bore 2 of the cooling water flow path 3 and the adjacent cylinder bore 2, and the first porous body 12 is attached in a curved state along the side of the molded body 11 including the convex curved surface 111. In particular, the curved portion arranged between the cylinder bores 2 has a larger curvature than other portions, and the first porous body 12 tends to be difficult to restore. In addition, the first porous body 12 attached to the convex curved surface 111 of the molded body 11 in this manner is difficult to stretch in the circumferential direction during restoration, so restoration in the thickness direction is suppressed. Therefore, in this embodiment, by overlapping a part of the second porous body 13 on a part of the first porous body 12 attached to one side 11a of the molded body 11 including the convex curved surface 111, the desired thickness can be obtained during restoration as described above. The first porous body 12 is attached in a curved state along the convex curved surface 111 of the molded body 11, and the second porous body 13 is arranged so as to overlap the ends on both sides of the first porous body 12. Therefore, by overlapping the second porous body 13 between the part of the first porous body 12 that is difficult to restore and the molded body 11, a part of the first porous body 12 is restored in a free state without being directly fixed to the molded body 11, so that it is easier to obtain the desired thickness of the porous body. In particular, the spacer 10 of this embodiment has overlapping parts 15, 15 on both sides of the flow direction of the first porous body 12, and the number of parts fixed to the molded body 11 is reduced, so that the difference in the circumferential length between the fixed side (one side 11a side of the molded body 11) and the surface side (side facing the inner wall surface 3c) of the first porous body 12 during restoration of the first porous body 12 is reduced, making it easier to restore in the thickness direction.

Next, a method for manufacturing the spacer 10 will be described with reference to FIGS.
The manufacturing method of the spacer 10 in this embodiment includes a first positioning step of positioning the first porous body 12 using a positioning protrusion 212 provided on the molding die 200 (first die 210), and a second positioning step of positioning the second porous body 13 of the multiple porous bodies on the first porous body 12. Furthermore, the manufacturing method of the spacer 10 in this embodiment includes a resin injection step of injecting a resin material r into the cavity 230 of the molding die 200 after closing the mold, and integrally molding the first porous body 12 and the second porous body 13 in a state where the resin material r is impregnated into a portion of the molded body 11. In the second positioning step, a portion of the second porous body 13 is overlapped with a portion of the first porous body 12, and is positioned at a position where the position where the positioning protrusion 212 is formed and the depth direction of the cooling water flow path 3 overlap.
A detailed description will be given below along the flow chart shown in steps S101 to S106 in Fig. 5. In the following description, the manufacturing steps in Fig. 5 will be abbreviated to "Sxxx" instead of "Step Sxxx".

<Mold>
First, the molding die 200 used in manufacturing the spacer 10 will be described. As shown in FIG. 6C, the molding die 200 is composed of a first die 210 which is a fixed die and a second die 220 which is a movable die which can move toward and away from the first die 210. The first die 210 has a first cavity surface 211 and a substantially cylindrical positioning protrusion 212 provided on a concave curved surface portion 211a of the first cavity surface 211. The second die 220 has a second cavity surface 221 and a resin supply portion 222 formed penetrating the second cavity surface 221. The molding die 200 forms a cavity 230 which is a space filled with the resin material r and is composed of the first cavity surface 211 and the second cavity surface 221 by clamping the first die 210 and the second die 220.

<Manufacturing method>
As shown in Fig. 6(a), in the mold open state, the through hole 12c of the first porous body 12 is inserted into the positioning protrusion 212 of the first mold 210, and the first porous body 12 is placed on the first cavity surface 211 of the first mold 210 in a first positioning step (S101). Since the first porous body 12 is a thin, flexible sheet, the first porous body 12 can be curved and placed along the concave curved surface portion 211a of the first cavity surface 211. Furthermore, by inserting the through hole 12c formed in the first porous body 12 into the positioning protrusion 212, the first porous body 12 can be easily positioned at a desired position, and in the resin injection step (S104) described later, the first porous body 12 can be prevented from moving under the injection pressure of the resin material r.

Next, as shown in FIG. 6(b), a second positioning step is performed in which the second porous body 13 is placed on top of the first porous body 12 (S102). At this time, since the second porous body 13 is a thin, flexible sheet, it can be curved and placed along the convex curved surface of the first cavity surface 211. The second porous body 13 is placed at a position where the recessed portion 130 overlaps with the position where the positioning protrusion 212 is formed in the depth direction of the cooling water flow path 3 while avoiding the through hole 12c of the first porous body 12. Therefore, the recessed portion 130 is placed so as to sandwich the positioning protrusion 212 from both sides in the depth direction of the cooling water flow path 3. In a similar manner, another sheet of the second porous body 13 is placed on top of the first porous body 12.

After the first positioning step and the second positioning step are performed, the second die 220 is brought close to the first die 210 and closed (S103). This forms a cavity 230. Then, as shown in FIG. 6(c), a resin injection step is performed in which the molten resin material r supplied from the outside via the resin supply unit 222 is injected into the cavity 230, and the resin material r is impregnated into a portion of the first porous body 12 and the second porous body 13, and the molded body 11 is integrally molded (S104). After that, the resin material r filled in the cavity 230 is cooled and solidified under a pressure holding state (S105). The molded body 11 is molded by solidifying the resin material r. In addition, the recessed portion 14 is formed by the resin material r that has flowed between the outer peripheral surface of the positioning protrusion 212 and the second die 220.

After the resin material r has solidified to form the molded body 11, the first die 210 and the second die 220 are separated to open the mold (S106). The molded body 11 is then removed from the first die 210, and the solidified portion in the resin supply section 222 is cut off to obtain the spacer 10.

According to the manufacturing method of the spacer 10 of this embodiment, the spacer 10 is manufactured by overlapping a part of the second porous body 13 with a part of the first porous body 12 and arranging it at a position where the positioning protrusion 212 is formed and overlaps in the depth direction of the cooling water flow path 3. Therefore, when the thickness of the first porous body 12 and the second porous body 13 increases due to the addition of a predetermined external factor, the part of the first porous body 12 that is difficult to restore can be compensated for by the overlapping part 15 of the second porous body 13 to achieve the desired thickness. Therefore, since the flow of cooling water in the depth direction of the recessed part 14 is restricted, it is possible to manufacture a spacer 10 that can regulate the flow rate and flow speed of the cooling water flowing through the cooling water flow path 3 as specified.

<Modification>
Next, a modified example of the spacer 10 according to the first embodiment will be described with reference to Figs. 7(a) to (c). Note that the description of the configuration and effects of the parts common to the first embodiment will be omitted. Figs. 7(a) to (c) each show a schematic diagram of the positional relationship between the first porous body 12 and the second porous body 13 of the spacer 10 according to the modified example and the recessed portion 14 (the positioning protrusion 212 of the mold 200), and the molded body 11 is omitted. In addition, the right side of Fig. 7 is one side in the flow direction of the cooling water flow path 3, and the left side is the other side. In addition, the upper side of Fig. 7 is the upper side in the depth direction of the cooling water flow path 3, and the opposite side is the lower side. In addition, in Figs. 7(a) to (c), the overlapping portion 15 where the first porous body 12 and the second porous body 13 overlap is shown by hatching with oblique lines.

The first porous body 12 shown in FIG. 7(a) is a rectangular sheet body with two round through holes 12c spaced apart along the depth direction, and the second porous body 13 has a depth dimension greater than the depth dimension of the first porous body 12, which is similar to the above embodiment. However, the second porous body 13 is disposed only on one side of the first porous body 12 in the flow direction, and the shape of the second porous body 13 is different from the above embodiment. The second porous body 13 shown here has a rectangular main body 13A and a protruding portion 13B that protrudes from approximately the center in the depth direction at the end 13Aa on the other side of the flow direction of the main body 13A to the other side in the flow direction.

The protrusion 13B of the second porous body 13 is disposed between the through holes 12c, 12c of the first porous body 12 and is integrally formed with the molded body 11. As a result, the overlapping portion 15 of the second porous body 13 is provided between the through holes 12c, 12c of the first porous body 12, and the overlapping portion 15 is horizontally formed into a substantially T-shape as shown in FIG. 7(a). During manufacturing, the positioning protrusion 212 is inserted into the through holes 12c, 12c of the first porous body 12, and after molding, the recessed portion 14 is formed by the positioning protrusion 212. Therefore, in the modified example, the recessed portions 14, 14 are formed at positions overlapping in the depth direction, and the overlapping portion 15 is located between these recessed portions 14, 14, so that the overlapping portion 15 of the second porous body 13 can push up the first porous body 12 during restoration and restore to the desired thickness as a whole. Therefore, even if there are recesses 14, 14, it is possible to prevent the cooling water from flowing up and down in the depth direction.

7(b), the through holes 12c, 12c are arranged in a line at a distance from each other along the flow direction of the cooling water flow passage 3, and are arranged on the upper side of the first porous body 12 in the depth direction, which is different from the above embodiment. The second porous body 13 has a rectangular main body 13A and a protruding portion 13B protruding from the lower portion of the end portion 13Aa on the other side of the flow direction of the main body 13A to the other side of the flow direction, and has an inverted L shape in a side view. The second porous body 13 is arranged so that the through holes 12c, 12c are located on the upper side of the protruding portion 13B in the depth direction, and thus the overlapping portion 15 is formed on the lower side of the through holes 12c, 12c in the depth direction. Therefore, even in this modified example, the overlapping portion 15 of the second porous body 13 pushes up the first porous body 12 when restored, and can restore the entire body to the desired thickness, so that even if there are recessed portions 14, 14, the cooling water can be restricted from flowing up and down in the depth direction.

In FIG. 7(c), a first porous body 12 and a second porous body 13, both of which are rectangular sheets, are used. The second porous body 13 is formed larger than the first porous body 12. The through hole 12c is provided at a position offset to one side of the flow direction of the cooling water flow passage 3 of the first porous body 12, and the second porous body 13 also has a round through hole 13c at a position offset to the other side of the flow direction of the cooling water flow passage 3. The through hole 13c of the second porous body 13 is formed to have a larger diameter than the through hole 12c of the first porous body 12, and the first porous body 12 and the second porous body 13 are arranged so that these through holes 12c, 13c overlap in the thickness direction. Therefore, in this case, during manufacturing, the positioning protrusion 212 is inserted into the through hole 12c of the first porous body 12 and the through hole 13c of the second porous body 13. In this case, the overlapping portion 15 is provided around the through hole 13c of the second porous body 13, and the surrounding area of the depression 14 formed inside the through hole 12c of the first porous body 12 becomes the overlapping portion 15. Therefore, even in this modified example, the overlapping portion 15 of the second porous body 13 pushes up the first porous body 12 when restored, and can restore the desired thickness as a whole, so that even if the depressions 14, 14 are present, it is possible to restrict the flow of cooling water up and down in the depth direction.

Second Embodiment
Next, a spacer 10 according to a second embodiment will be described with reference to Figures 8 and 9. Descriptions of the configuration and effects of parts common to the first embodiment will be omitted. Also, in Figure 8(a) and its modified examples, Figures 8(b) and 8(c) and Figures 9(a) and 9(b), the molded body 11 is not shown, and the positional relationship between the first porous body 12 and the second porous body 13 and the recessed portion 14 (the positioning protrusion 212 of the molding die 200) is shown in schematic form.

The spacer 10 of the second embodiment shown in FIG. 8(a) differs from the first embodiment in that it has a concave recess 14 on the periphery of the first porous body 12. The first porous body 12, which is made of a rectangular sheet body, is not positioned by inserting the positioning protrusion 212 into the through hole during manufacturing, but is positioned by the first positioning protrusions 212A, 212A along the upper corner in the depth direction and the second positioning protrusion 212B along approximately the center in the flow direction on the lower side in the depth direction. The first positioning protrusion 212A is formed in an approximately inverted L shape when viewed from the side, and the second positioning protrusion 212B is formed in a rectangular shape extending in the flow direction when viewed from the side.

The second porous body 13 is made of a rectangular sheet body of the same shape and size as the first porous body 12, and a part of the upper end 13b in the depth direction is in contact with the lower end of the first positioning protrusion 212A on one side in the flow direction, and is arranged to overlap a part of the first porous body 12 in the thickness direction. In this embodiment, the second porous body 13 is arranged without contacting the second positioning protrusion 212B, and has a rectangular overlapping part 15 in a side view. The overlapping part 15 overlaps a part of the first positioning protrusion 212A on one side in the flow direction in the depth direction. The first positioning protrusions 212A, 212A and the second positioning protrusion 212B that engage the peripheral part of the first porous body 12 during manufacturing become a recessed part 14 after molding. Then, the overlapping part 15 is provided by overlapping a part of the recessed part 14 configured to correspond to the first positioning protrusion 212A located on one side in the flow direction among these multiple recessed parts 14 in the depth direction.

8(a), the positioning protrusion 212A is aligned with the upper corner of the first porous body 12 in the depth direction, so there is a risk that the resin material r may get in between the end face of the first porous body 12 and the positioning protrusion 212A during manufacturing. Then, when the resin material r is impregnated into the end face of the first porous body 12, there is a risk that a part of the end face of the first porous body 12 or its vicinity may not be restored to the desired thickness. Therefore, in the spacer 10 of the second embodiment, as in the first embodiment, a part of the second porous body 13 overlaps a part of the first porous body 12 and has an overlapping part 15 that overlaps the formation position of the recessed part 14 and the depth direction of the cooling water flow path 3. Therefore, even if there is a concave recess 14 formed when the first porous body 12 is positioned during manufacturing, when the thickness of the first porous body 12 and the second porous body 13 increases as a result of the supply of cooling water to the cooling water flow path 3, the portion of the first porous body 12 that is difficult to restore can be compensated for by the overlapping portion 15 of the second porous body 13 to achieve the desired thickness. Therefore, the flow rate and flow speed of the cooling water flowing through the cooling water flow path 3 can be regulated by the spacer 10. More specifically, even in this second embodiment, the overlapping portion 15 of the second porous body 13 pushes up the first porous body 12 during restoration, so that the entire body can be restored to the desired thickness, so that even if there are recesses 14, 14, it is possible to regulate the flow of cooling water up and down in the depth direction.

In the second embodiment, unlike the first embodiment, there is no need to form through holes 12c in the first porous body 12, so the work process for forming through holes is unnecessary. Therefore, finishing processing when the through holes are not completely removed and are partially connected, and hole inspection are not required, and the work can be simplified. In addition, equipment for forming through holes in the first porous body 12 is not required, and further, the die does not have holes, which simplifies the process, reducing costs. Furthermore, if the die has holes, the sheet will clog the holes, so it is necessary to remove the debris. However, since the die does not have holes, there is also the advantage that the effort of removing debris from the holes in the die when opening the through holes is eliminated.

In the second embodiment, in the first positioning step, instead of inserting the through hole into the positioning protrusion 212, the peripheral portion of the first porous body 12 is abutted against the positioning protrusion 212 (first positioning protrusion 212A and second positioning protrusion 212B) and locked to position. Other than this step, the spacer 10 can be manufactured in a manner substantially similar to the manufacturing method of the spacer 10 of the first embodiment shown in Figures 5 and 6. In the step of positioning the peripheral portion of the first porous body 12 with the positioning protrusion 212 (first positioning protrusion 212A and second positioning protrusion 212B), the first porous body 12 can be easily positioned by arranging the first porous body 12 so that it is aligned with the positioning protrusion 212 provided on the molding die 200 according to the shape of the first porous body 12. Also in this embodiment, the first porous body 12 is held at multiple locations on the peripheral portion by multiple positioning protrusions 212, so that the first porous body 12 can be prevented from moving under the injection pressure of the resin material.

<Modification>
Next, the modified examples shown in Figures 8(b) and 8(c) will be described, in which the description of the configurations and effects of the parts common to the second embodiment shown in Figure 8(a) will be omitted.
The first porous body 12 in Fig. 8(b) has a cross shape in side view with multiple recessed portions 120 formed by recessing and cutting out the corners of a rectangular sheet body. The second porous body 13 has a rectangular main body 13A and a protruding portion 13B in which the approximate center in the depth direction at the end portion 13Aa on the other side in the flow direction of the main body 13A protrudes to the other side in the flow direction. The protruding portion 13B is formed so that its dimension in the depth direction is smaller than the dimension between the positioning protrusions 212, 212 aligned in the depth direction.

In this example, four positioning protrusions 212 are provided, and are rectangular in side view extending in the depth direction. To explain in more detail, the positioning protrusions 212 have a depth dimension that is approximately the same as the depth dimension of the recessed portion 120, and a flow direction dimension that is approximately half the flow direction dimension of the recessed portion 120. The first porous body 12 is arranged so that the four recessed portions 120 are aligned along the four positioning protrusions 212. The main body portion 13A of the second porous body 13 is arranged so that a part of one side of the flow direction of the first porous body 12 overlaps in the thickness direction. The protrusion portion 13B of the second porous body 13 is arranged so as to be located between the two positioning protrusions 212, 212 on one side of the flow direction. In addition, the end portion 13Aa on the other side of the flow direction of the main body portion 13A of the second porous body 13 is arranged so as to abut against the two positioning protrusions 212, 212 on one side of the flow direction. Therefore, the positioning protrusion 212 acts to position not only the first porous body 12 but also the second porous body 13. Therefore, after molding, a part of the second porous body 13 overlaps a part of the first porous body 12 in the thickness direction, and has an overlapping part 15 that overlaps with the two recessed parts 14, 14 on one side of the flow direction in the depth direction of the cooling water flow path 3. Even in this modified example of the second embodiment, the overlapping part 15 (protrusion 13B) of the second porous body 13 pushes up the first porous body 12 when restored, and can be restored to the desired thickness as a whole, so that even if the recessed parts 14, 14 are present, it is possible to restrict the flow of cooling water up and down in the depth direction.

Next, the modified example of FIG. 8(c) will be described. The first porous body 12 and the positioning protrusion 212 of FIG. 8(c) have substantially the same configuration as the modified example of FIG. 8(b). The second porous body 13 is a long rectangular sheet extending in the flow direction of the cooling water flow path 3, and is formed with a dimension in the flow direction larger than that of the first porous body 12. The second porous body 13 is formed so that the dimension in the depth direction of the cooling water flow path 3 is smaller than the dimension between the positioning protrusions 212, 212 arranged in the depth direction, and the second porous body 13 is arranged to pass between the positioning protrusions 212, 212 arranged in the depth direction. Even in this modified example of the second embodiment, the overlapping portion 15 of the second porous body 13 can push up the first porous body 12 when restored, and can restore the desired thickness as a whole, so that even if there are multiple recessed portions 14, it is possible to restrict the cooling water from flowing up and down in the depth direction.

Next, a modified example shown in FIG. 9(a) will be described. The first porous body 12 has a shape having a protruding portion 12d that protrudes upward in the depth direction of the rectangular sheet body on one side in the flow direction and overlaps with the formation position of the recessed portion 14 in the depth direction, and the second porous body 13 has a recessed portion 130 in which the center of the depth direction of the end portion 13a on the other side in the flow direction is recessed. During manufacture, the first porous body 12 is arranged so that the center of the depth direction at the end portions 12a, 12a on both sides in the flow direction is aligned with the first positioning protrusions 212A, 212A, and the center of the flow direction at the end portions 12b, 12b on both sides in the depth direction is aligned with the second positioning protrusions 212B, 212B. The second porous body 13 is arranged on one side in the flow direction of the first porous body 12, and the recessed portion 130 is arranged to surround the first positioning protrusion 212A on one side in the flow direction. The second porous body 13 is arranged so as not to come into contact with the first positioning protrusion 212A and the second positioning protrusion 212B. Here, the second porous body 13 has two overlapping portions spaced apart from each other in the depth direction of the second porous body 13 via the recessed portion 130, and the overlapping portion at the top of the depth direction is the overlapping portion 15a overlapping the recessed portion 14 in the depth direction. Therefore, after molding, the overlapping portion 15a overlapping the recessed portion 14 in the depth direction of the cooling water flow path 3 pushes up the first porous body 12 during restoration, so that the first porous body 12 can be restored to a desired thickness as a whole, and therefore, even if the recessed portion 14 is present, the cooling water can be restricted from flowing in the vertical direction in the depth direction. On the other hand, the overlapping portion 15b at the bottom of the depth direction does not overlap the recessed portion 14 in the depth direction, but overlaps with a part of the first porous body 12, so that it is restored more sufficiently than other portions, and therefore the flow of the cooling water can be restricted.
Furthermore, in the central portion of the first porous body 12 in the flow direction, the distance between the upper and lower depressions 14 is large, and even if the first porous body 12 is restored to a kamaboko shape, the central portion in the depth direction is sufficiently restored, so that the flow of cooling water in the depth direction can be regulated without overlapping the second porous body 13.

Next, a modified example shown in FIG. 9(b) will be described. The first porous body 12 has a shape in which both ends 12b, 12b in the depth direction are triangularly recessed toward the center in the depth direction. The positioning protrusions 212 are pentagonal in side view along the shape of both ends of the first porous body 12 in the depth direction, and two are provided side by side at a distance in the depth direction. The second porous body 13 has a rectangular shape extending in the flow direction, and its dimension in the depth direction is formed smaller than the distance between the positioning protrusions 212, 212 lined up in the depth direction. The second porous body 13 is arranged so that a part of it overlaps with the first porous body 12 in the thickness direction, and has an overlapping part 15 in which the other side part in the flow direction overlaps with the positioning protrusions 212, 212 in the depth direction. Therefore, the overlapping portion 15 that overlaps the recessed portion 14, 14 and the cooling water flow path 3 in the depth direction pushes up the first porous body 12 during restoration, and the entire body can be restored to the desired thickness. Therefore, even if the recessed portions 14, 14 are present, the restoration of the overlapping portion 15 can regulate the cooling water from flowing up and down in the depth direction.

As described above, the spacer 10 is not limited to the above-mentioned embodiments or those shown in the figures. In the above-mentioned embodiments, the first porous body 12 and the second porous body 13 are cellulose sponges, but are not limited to this and may be, for example, foamed rubber. In that case, the adhesion between the foamed rubber and the resin material r may be improved by applying an adhesive to the surface of the foamed rubber that contacts the resin material r during manufacturing. Furthermore, the multiple porous bodies may be made of different materials. The shapes of the first porous body 12 and the second porous body 13 are also not limited to the examples shown in the figures, and the location of the overlapping portion 15 is determined according to the area where the cooling water is to be regulated and the formation position of the recessed portion 14.

In addition, in each of the above-mentioned embodiments, the molded body 11 has a curved shape along the cylinder bore 2, but is not limited to this, and may have a shape corresponding to the cooling water flow path 3 and may be a flat shape. The positions at which the first porous body 12 and the second porous body 13 are fixed to the molded body 11 (positions in the depth direction of the cooling water flow path 3 and positions in the flow direction) may be appropriately changed according to the required specifications, such as the stability of the spacer 10 in the cooling water flow path 3 or the cooling function of the cooling water flowing through the cooling water flow path 3. Therefore, a plurality of first porous bodies 12 may be provided for one spacer 10, and although one second porous body 13 is provided for one first porous body 12 in Figures 7 to 9, a plurality of second porous bodies 13 may be provided. In addition, in the second embodiment and its modified example, the positioning protrusion 212 may act as a member for positioning not only the first porous body 12 but also the second porous body 13. The shape of the molded body 11 is exemplified as semi-cylindrical (split in half), but it may be a full cylinder that covers the entire circumference of the cooling water flow path 3, or it may be a partial cylinder. It goes without saying that a known cooling medium such as antifreeze can be used as the cooling water that flows through the cooling water flow path 3.

A Internal combustion engine 1 Cylinder block 2 Cylinder bore 3 Cooling water flow passage 10 Spacer 11 Molded body 11a One side surface 111 Convex curved surface 12 First porous body 12c Through hole 13 Second porous body 14 Depression portion 15 Overlap portion 200 Molding die 211a Concave curved surface portion 212 Positioning protrusion

Claims (13)

A spacer that is disposed in a cooling water flow passage provided in a cylinder block of an internal combustion engine and regulates the flow of cooling water,
A molded body made of a resin material;
A first porous body having a through hole provided on one side surface of the molded body;
A second porous body provided on the one side surface;
a concave recess portion formed inside the through hole on the one side surface,
The first porous body and the second porous body are partially impregnated with the resin material and molded integrally with the molded body, and have a characteristic that their thickness in the thickness direction increases when a predetermined external factor is applied;
A spacer characterized in that a portion of the second porous body overlaps a portion of the first porous body and has an overlapping portion that overlaps the formation position of the recess portion in the depth direction of the cooling water flow path. A spacer that is disposed in a cooling water flow passage provided in a cylinder block of an internal combustion engine and regulates the flow of cooling water,
A molded body made of a resin material;
A first porous body provided on one side of the molded body;
A second porous body provided on the one side surface;
a concave recess portion formed in a peripheral portion of the first porous body on the one side surface,
The first porous body and the second porous body are partially impregnated with the resin material and molded integrally with the molded body, and have a characteristic that their thickness in the thickness direction increases when a predetermined external factor is applied;
A spacer characterized in that a portion of the second porous body overlaps a portion of the first porous body and has an overlapping portion that overlaps the formation position of the recess portion in the depth direction of the cooling water flow path. In claim 1 or 2,
The molded body has a convex curved surface on the one side surface,
A spacer, characterized in that the first porous body is attached to the one side surface of the molded body including the convex curved surface. In claim 3,
A spacer, characterized in that the convex curved surface of the molded body is arranged in a portion formed between two cylinder bores in the cooling water flow path. In claim 3 or claim 4,
The first porous body is attached in a curved state along the convex curved surface of the molded body,
A spacer, characterized in that the second porous body is arranged so as to overlap both end portions of the first porous body. In any one of claims 1 to 5,
A spacer, characterized in that the overlapping portion is provided between the molded body and the first porous body. In any one of claims 1 to 6,
A spacer, characterized in that the overlapping portions are provided on both sides of the recessed portion in the depth direction. In any one of claims 1 to 7,
the first porous body and the second porous body are cellulose-based sponges,
A spacer, wherein the predetermined external factor is moisture. A method for manufacturing a spacer, which includes a molded body made of a resin material and a plurality of porous bodies having a property of increasing in thickness in a thickness direction when a predetermined external factor is applied, and which is disposed in a cooling water flow path provided in a cylinder block of an internal combustion engine and regulates the flow of cooling water, comprising:
a first positioning step of positioning a first porous body among the plurality of porous bodies using a positioning protrusion provided on a molding die;
a second positioning step of arranging a second porous body of the plurality of porous bodies on the first porous body;
a resin injection step of injecting the resin material into the cavity of the molding die after the mold is closed, and integrally molding the first porous body and the second porous body in a state where the resin material is impregnated into a part of the first porous body and the second porous body,
A method for manufacturing a spacer, characterized in that in the second positioning process, a portion of the second porous body is overlapped with a portion of the first porous body and positioned at a position overlapping with the formation position of the positioning protrusion and the depth direction of the cooling water flow path. In claim 9,
A method for manufacturing a spacer, characterized in that in the first positioning step, a through hole formed in the thickness direction of the first porous body is inserted into the positioning protrusion to perform positioning. In claim 9 or 10,
A method for manufacturing a spacer, wherein the first positioning step is performed by abutting a peripheral portion of the first porous body against the positioning protrusion. In any one of claims 9 to 11,
A method for manufacturing a spacer, comprising the steps of: providing the positioning protrusion on a concave curved surface of the molding die. In any one of claims 9 to 12,
A method for manufacturing a spacer, wherein the first porous body and the second porous body are made of a cellulose sponge formed into a thin sheet.

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