Spacer

Abstract

To provide a spacer which can be installed in a cooling water flow passage without combining a plurality of split bodies in advance.SOLUTION: A spacer 10 for regulating a flow of cooling water comprises: a spacer body 11 which is constructed by combining a plurality of split bodies 12A, 12B; and a porous sheet body 13 having a characteristic of expanding in a thickness direction from a compressed state to be restored in response to a prescribed external factor. The split bodies are provided with positioning parts 14A, 14B which can be engaged with the other adjacent split bodies. The spacer body has a positioning structure by which relative positions of one split body and the other split body are positioned by engaging with the positioning part of the other split body by displacement of the positioning part of the one split body upon restoration of the sheet body from the compressed state, with the positioning parts of the one split body and the other split body being arranged opposite each other in a cooling water flow passage 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a spacer that is disposed in a cooling water passage provided in a cylinder block of an internal combustion engine so as to surround a cylinder bore, and regulates the flow of cooling water. [Background Art]

[0002] In a cooling water passage provided in a cylinder block of an internal combustion engine so as to surround a cylinder bore, a spacer for regulating the flow rate, flow velocity and the like of circulating cooling water is inserted and disposed through an opening at an upper portion of the cooling water passage. In the following Patent Documents 1 and 2, a spacer shaped to surround cylinder bores of a plurality of cylinders is configured by combining a plurality of divided bodies. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Laying-Open No. 2008-208744 [Patent Document 2] Japanese Patent Laying-Open No. 2021-080856 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Incidentally, in a spacer configured by a plurality of divided bodies as in Patent Documents 1 and 2, a step of combining the plurality of divided bodies is required before the spacer is disposed in the cooling water passage. In Patent Document 1, a holder for connecting the plurality of divided bodies to each other is required, and a step of adjusting the relative positions of the divided bodies by this holder and connecting them is necessary. Further, in Patent Document 2, since the shapes of the end portions and the regulating portion are complicated, the shape of the mold for manufacturing tends to be complicated.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a spacer that can be disposed in a cooling water passage without previously combining a plurality of divided bodies. [Means for solving the problem]

[0006] To achieve the above objective, the spacer of the present invention is a spacer that is placed in a cooling water passage provided in the cylinder block of an internal combustion engine so as to surround the cylinder bore and restricts the flow of cooling water, and comprises a spacer body configured to conform to the shape of the cylinder bore by combining a plurality of rigid divided parts, and predetermined external factors Contact with the cooling water The spacer body comprises a porous sheet body having the characteristic of expanding in the thickness direction and restoring from a compressed state, the plurality of divided bodies are provided with positioning portions that can engage with each other adjacent divided bodies, at least one of the plurality of adjacent divided bodies has the sheet body in a compressed state on one side, and the spacer body has a positioning structure in which, when the positioning portions of the one divided body and the other divided body are arranged facing each other in the cooling water flow path, the positioning portion of the one divided body is displaced when the sheet body restores from a compressed state and engages with the positioning portion of the other divided body, thereby positioning the relative position of the one divided body and the other divided body.

[0007] In the above-described spacer, the positioning structure may be a structure that restricts the relative displacement of the plurality of divided bodies in the depth direction, circumferential direction, and groove width direction in the cooling water flow path when adjacent positioning portions are engaged with each other.

[0008] Furthermore, in the above-mentioned spacer, the positioning structure may be an uneven structure with recesses and protrusions that engage with each other.

[0009] Furthermore, in the above spacer, the divided body is such that when placed in the cooling water flow path, it engages with each other, thereby separating adjacent positioning portions. circumferential within the cooling water flow channel A separation restriction section may be provided to restrict displacement in that direction.

[0010] Furthermore, in the above-described spacer, the other side of the spacer body, which is the side opposite to the side on which the sheet body is provided, may abut against the wall surface of the cooling water channel.

[0011] Furthermore, in the above-described spacer, the sheet body may be provided in a position that overlaps with the positioning portion in the thickness direction of the divided body. [Effects of the Invention]

[0012] Since the spacer of the present invention has the above-described configuration, multiple divided parts can be placed in the cooling water flow path without having to combine them in advance. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional plan view illustrating the arrangement of a spacer according to the first embodiment within the cooling water passage provided in the cylinder block of an internal combustion engine. [Figure 2] This is a schematic, enlarged perspective view of the key parts illustrating the positioning structure of the spacer. [Figure 3] (a) to (c) are explanatory diagrams showing the process over time of the sheet body being restored from its compressed state and the positioning parts engaging with each other, in an enlarged view of section A in Figure 1. [Figure 4] (a) is a schematic side view of the main part of the spacer, and (b) is a cross-sectional view taken along the line B-B' when the sheet body of (a) is restored. [Figure 5] This figure shows a first modified example of the first embodiment, where (a) and (b) are schematic perspective views of the main part, (c) is a schematic plan view of the main part, and (d) is a schematic cross-sectional view of the main part in a state where the sheet body has been restored in the cooling water flow path. [Figure 6] This figure shows a second modified example of the first embodiment, where (a) and (b) are schematic exploded perspective views showing the main parts, and (c) is a schematic cross-sectional view of the main parts in a state where the sheet body has been restored in the cooling water flow path. [Figure 7](a) is a schematic exploded perspective view showing the main part of a third modified example of the first embodiment. (b) to (d) are figures showing a fourth modified example of the first embodiment, where (b) and (c) are schematic exploded perspective views showing the main part, and (d) is a schematic cross-sectional view of the main part in the state in which the sheet body has been restored in the cooling water flow path. [Figure 8] This figure shows a second embodiment, where (a) is a schematic perspective view showing the main part of one of the divided parts, (b) is a schematic perspective view showing the main part of the other divided part, and (c) is a schematic perspective view showing the positioning structure. [Figure 9] (a) is a schematic side view showing the positioning structure of the spacer, (b) is a schematic top view of (a), (c) is a cross-sectional view of (a) taken along the line C-C' when the sheet body is compressed, and (d) is a cross-sectional view of (a) taken along the line C-C' when the sheet body of (c) has recovered in the cooling water flow path. [Figure 10] (a) is a cross-sectional view taken along the line D-D' in Figure 9(c) within the cooling water flow path, and (b) is a cross-sectional view taken along the line E-E' in Figure 9(d). (c) is an explanatory diagram for illustrating the separation restriction section. [Figure 11] (a) is a schematic exploded perspective view showing the main part of the first modification of the second embodiment, (b) is a schematic perspective view showing the main part in the state in which the sheet body has been restored in the cooling water flow path, (c) is a schematic exploded perspective view showing the main part of the second modification of the second embodiment, and (d) is a schematic perspective view showing the main part in the state in which the sheet body has been restored in the cooling water flow path. [Figure 12] This figure shows a third modified example of the second embodiment, where (a) is a schematic exploded perspective view showing the main part, (b) is a schematic plan view of the main part, and (c) is a schematic cross-sectional view of the main part in a state where the sheet body has been restored in the cooling water flow path. [Figure 13] This figure shows a fourth modified example of the second embodiment, where (a) is an explanatory diagram showing one of the divided parts, (b) is a schematic perspective view showing the other divided part, (c) is a schematic cross-sectional view of the main part when the sheet body is compressed in the cooling water channel, and (d) is a schematic cross-sectional view of the main part when the sheet body is restored in the cooling water channel. [Figure 14]It is a diagram showing a spacer according to the third embodiment, where (a) is a schematic cross-sectional view of essential parts in a state where the sheet body is compressed in the cooling water channel, (b) is a schematic cross-sectional view of essential parts in a state where the sheet body is restored in the cooling water channel, (c) is a schematic side view of the other divided body as viewed along line F in (a), and (d) is a schematic side view of one divided body as viewed along line G in (a). [Figure 15] (a) to (c) are explanatory diagrams showing the process of engagement between positioning portions of a positioning structure over time. [Figure 16] It is a diagram showing a modified example of the same spacer, where (a) is a schematic perspective view showing essential parts of one divided body, and (b) is a schematic perspective view showing essential parts of the other divided body.

Mode for Carrying Out the Invention

[0014] The spacer 10 of the present embodiment is disposed in the cooling water channel 3 provided in the cylinder block 1 of the internal combustion engine 4 in a state surrounding the cylinder bore 2, and regulates the flow of cooling water. The spacer 10 includes: a spacer main body 11 configured to conform to the shape of the cylinder bore 2 by combining a plurality of rigid divided bodies 12; and a porous sheet body 13 having a property of expanding and restoring from a compressed state in the thickness direction due to a predetermined external factor. The plurality of divided bodies 12 are provided with positioning portions 14A and 14B that can mutually engage with another adjacent divided body 12. At least one divided body 12A among the plurality of adjacent divided bodies 12 is provided with the sheet body 13 in a compressed state on one surface thereof. In the spacer main body 11, the positioning portions 14A and 14B of the one divided body 12A and the other divided body 12B respectively face each other and are disposed in the cooling water channel 3. In this disposed state, when the sheet body 13 restores from the compressed state, the positioning portion 14A of the one divided body 12A displaces and engages with the positioning portion 14B of the other divided body 12B. Thereby, the spacer main body 11 has a positioning structure that positions the relative position between the one divided body 12A and the other divided body 12B. This will be described in detail below.

[0015] <First Embodiment> First, the spacer 10 according to the first embodiment will be described with reference to Figures 1 to 4. In the following description, the state in which the spacer is placed in the cooling water passage 3 will be used as a reference, with the opening 3e side of the cooling water passage 3 being the upper side in the depth direction and the opposite side being the lower side in the depth direction. In the cooling water passage 3, the side on which one divided body 12A (first divided body 12A) is placed will be the one side in the circumferential direction, and the side on which the other divided body 12B (second divided body 12B) is placed will be the other side in the circumferential direction. In other words, on the plane of Figure 1, the upper side will be the one side in the circumferential direction, and the opposite side will be the other side. Furthermore, in the groove width direction of the cooling water passage 3 (thickness direction of the spacer body 11 and divided body 12), the cylinder bore 2 side will be the one side, and the opposite side will be the other side.

[0016] <Internal Combustion Engine> As shown in Figure 1, the internal combustion engine 4 is composed of a cylinder block 1. The spacer 10, which is assembled to the internal combustion engine 4, is placed in the cooling water passage (water jacket) 3 of the cylinder block 1. A cylinder head (not shown) is placed on the upper surface of the cylinder block 1, and an oil pan (not shown) is placed on the lower surface of the cylinder block 1. The cylinder head is fastened integrally to the cylinder block 1 such that the opening 3e of the cooling water passage 3 is closed. The cylinder block 1 constitutes the internal combustion engine 4 having multiple cylinders, and multiple cylinder bores (cylinders) 2 are arranged in series adjacent to each other. In the following, the multiple cylinder bores (cylinders) 2 will be described as the 1st cylinder, 2nd cylinder, 3rd cylinder, etc., in order from the bottom of the plane of Figure 1. Multiple bolt insertion holes 1a are provided at appropriate locations on the cylinder block 1 for fastening to the cylinder head via a head gasket (not shown). Open deck type groove-shaped cooling water passages 3 are formed in a series around the multiple cylinder bores 2. Furthermore, a coolant inlet 3g and a coolant outlet 3h are provided at appropriate locations on the cylinder block 1, leading to the coolant passage 3. The coolant outlet 3h is connected by piping to a radiator (not shown), and the outlet side of the radiator is connected by piping to the coolant inlet 3g via a water pump (not shown). This configures the system to circulate coolant (including antifreeze) between the coolant passage 3 and the radiator. The white arrows in Figure 1 simply illustrate one example of the direction in which the coolant flows from the coolant inlet 3g to the coolant outlet 3h.

[0017] A cylinder bore wall 20 is formed between the cylinder bore 2 and the cooling water passage 3. The two wall surfaces facing each other across the cooling water passage 3 are composed of an inner circumferential wall 3c on the cylinder bore 2 side and an outer circumferential wall 3d on the opposite side of the cylinder bore 2. The cooling water passage 3 has a plurality of arc-shaped portions 3a formed to surround the cylinder bore 2 via the cylinder bore wall 20, and a plurality of constricted portions 3b formed in pairs and close to each other in the portions between adjacent cylinder bores 2, 2. The groove width of the constricted portions 3b is formed to be larger than the groove width of the other arc-shaped portions 3a of the cooling water passage 3. Since the cooling water passage 3 is formed along the cylinder bore wall 20, the cylinder bore wall 20 can be efficiently cooled by the flow of cooling water.

[0018] <Spacer> Next, the spacer 10 will be described. As shown in Figure 1, the spacer 10 is placed in the cooling water passage 3 to restrict the flow of cooling water flowing through the cooling water passage 3. The spacer 10 comprises a spacer body 11 and a sheet body 13. The spacer body 11 is configured to conform to the shape of the cylinder bore 2 by combining a plurality of rigid segmented bodies 12. The plurality of segmented bodies 12 are inserted from the opening 3e of the cooling water passage 3 and placed in the cooling water passage 3.

[0019] The multiple segmented bodies 12 constituting the spacer body 11 are made of a rigid material, and a hard resin material is preferred as such a material. Examples of resin materials include polyethylene, polypropylene, ABS, acrylic, polycarbonate, polyamide, polyacetal, polyphenylene sulfide, and polyether ether ketone. Examples of thermosetting resins include phenolic resin, epoxy resin, and polyurethane resin. Furthermore, the resin material may have various additives added to it, or it may be a resin composite material containing reinforcing fibers such as carbon fiber or glass fiber.

[0020] The spacer body 11 is divided approximately in the center in the circumferential direction. The spacer body 11 is composed of two divided parts 12: a first divided part 12A, which is one of the divided parts that includes a sheet body 13, and a second divided part 12B, which is the other divided part that does not include a sheet body 13. The circumferential length of the spacer body 11 in this embodiment is approximately half the circumferential length of the cooling water flow path 3.

[0021] The main body portion 120A of the first divided body 12A and the main body portion 120B of the second divided body 12B are each equipped with an arc-shaped portion 121 and a semi-arc-shaped portion 122 which is half the size of the arc-shaped portion 121 when viewed from above, and a connecting portion 123 which connects the arc-shaped portion 121 and the semi-arc-shaped portion 122. The tips of the respective semi-arc-shaped portions 122 of the first divided body 12A and the second divided body 12B overlap in the thickness direction and are arranged in the cooling water flow path 3, so that the spacer body 11 has a form in which three arc-shaped portions are arranged in the circumferential direction. In addition, the spacer body 11 is configured such that the other surface 11b, which is the surface opposite in the thickness direction to the one surface 11a on which the sheet body 13 is provided, comes into contact with the outer peripheral wall 3d of the cooling water flow path 3 when the sheet body 13 is restored. In other words, the other surfaces 12b, 12b in the thickness direction of the first divided body 12A and the second divided body 12B are configured to contact the outer peripheral wall 3d of the cooling water passage 3 when the sheet body 13 is restored. When the first divided body 12A and the second divided body 12B are engaged, the spacer body 11 is shaped to conform to the cooling water passage 3 that surrounds the multiple cylinder bores 2.

[0022] The positioning structure of the first divided body 12A and the second divided body 12B, provided by the positioning portions 14A and 14B, is positioned approximately at the circumferential center of the arc-shaped portion 3a of the cooling water passage 3 corresponding to the cylinder bore 2 of the second cylinder. As shown in Figures 1 and 2, the first divided body 12A has a recess 124 at the tip of the semi-arc-shaped portion 122 that is recessed on one side in the thickness direction, and when the sheet body 13 is restored, the end of the second divided body 12B overlaps with this recess 124. The recess 124 of the first divided body 12A is provided with two positioning portions 14A arranged at intervals in the depth direction. These positioning portions 14A are convex portions formed to protrude from the recess 124 in the thickness direction. The positioning portions 14A are formed in a pyramidal truncated shape and have a side surface 14Aa that is inclined to taper toward the tip side in a plan view.

[0023] Furthermore, one surface 12a of the first divided body 12A in the thickness direction is provided with a recess in the thickness direction that matches the thickness of the compressed sheet body 13, and the sheet body 13 is placed within this recess. As shown in Figure 3(a), one surface 12a of the first divided body 12A in the thickness direction and one surface 13a of the compressed sheet body 13 are substantially flush. The sheet body 13 has two protrusions 131 that project from the other end in the circumferential direction to the other side in the circumferential direction, spaced apart in the depth direction. The sheet body 13 is provided such that the two protrusions 131, 131 described above overlap with two positioning parts 14A, 14A in the thickness direction of the first divided body 12A.

[0024] The sheet body 13 only needs to have the property of expanding in the thickness direction and restoring due to predetermined external factors, and in this embodiment, a cellulose-based sponge that restores itself upon contact with moisture (cooling water) is used. The cellulose-based sponge is made of natural materials consisting of cellulose derived from pulp and natural fibers (e.g., cotton) added as reinforcing fibers, and has an open-cell structure and excellent water absorption. Here, cellulose has hydrophilic groups (OH) and is known to be chemically compatible with moisture. Therefore, when the cellulose-based sponge is dried under pressure, hydrogen bonds form between cellulose molecules and it is maintained in a compressed state, while when exposed to moisture from this state, water molecules break the hydrogen bonds between cellulose molecules and it restores itself from the compressed state.

[0025] The second divided body 12B has two positioning portions 14B arranged at a distance in the depth direction at one end in the circumferential direction, which is the side of the first divided body 12A. The positioning portions 14B are recesses that penetrate in the thickness direction, and are shaped so that the positioning portions 14A of the first divided body 12A can be inserted into them. Also, as shown by the dashed line in Figure 3(a), the positioning portions 14B have inclined side wall surfaces 14Ba such that, in a plan view, the opening width of the recess gradually decreases from one side to the other in the thickness direction. In the following description, the positioning portion 14A of the first divided body 12A is referred to as one positioning portion 14A, and the positioning portion 14B of the second divided body 12B is referred to as the other positioning portion 14B.

[0026] The spacer body 11 has a positioning structure in which the relative positions of the first divided body 12A and the second divided body 12B are positioned by one positioning portion 14A and the other positioning portion 14B. This positioning structure is configured as a concave-convex structure in which the other positioning portion 14B is a concave portion and the one positioning portion 14A is a convex portion that engages with each other.

[0027] One positioning section 14A has a shape in which the inclination of its side surface 14Aa matches the inclination of the side wall surface 14Ba of the other positioning section 14B. Furthermore, the projection dimension in the thickness direction of one positioning section 14A is approximately the same as the dimension in the thickness direction of the other positioning section 14B. And the depth dimension of one positioning section 14A is formed to be smaller than the depth dimension of the other positioning section 14B.

[0028] The other positioning section 14B has a side wall surface 14Ba that is inclined such that the opening width of the recess gradually decreases from one side to the other in the thickness direction. Therefore, the side wall surface 14Ba of the other positioning section 14B functions as a guide that guides the sheet body 13 into the other positioning section 14B when the sheet body 13 returns to its original position and the one positioning section 14A is displaced toward the positioning section 14B.

[0029] The side surface 14Aa of one positioning section 14A and the side wall surface 14Ba of the other positioning section 14B have the configuration described above. Therefore, even if the circumferential positions of one positioning section 14A and the other positioning section 14B are misaligned when they are placed in the cooling water flow path 3 as shown in Figure 3(a), one positioning section 14A can be guided into the other positioning section 14B as shown in Figures 3(b) and 3(c). Furthermore, when the relative positions of the first divided body 12A and the second divided body 12B are positioned, a gap is created between the other end face of the first divided body 12A in the circumferential direction and the side wall 124a of the recess 124 of the second divided body 12B.

[0030] Furthermore, as shown in Figure 4(b), the lower surface of one of the upper positioning sections 14A and the upper surface of one of the lower positioning sections 14A, as well as the lower surface of the other upper positioning section 14B and the upper surface of the other lower positioning section 14B, are inclined surfaces. Therefore, even if one positioning section 14A and the other positioning section 14B are misaligned in the depth direction, they can be guided by these inclined surfaces.

[0031] Furthermore, as shown in Figures 4(a) and 4(b), the other positioning portion 14B is formed with a greater depth dimension than the depth dimension of the first positioning portion 14A. Therefore, when the first positioning portion 14A is inserted with some play within the other positioning portion 14B, its displacement in the depth direction is restricted within the other positioning portion 14B. Also, when the first positioning portion 14A and the other positioning portion 14B are engaged, the two sides 14Aa, 14Aa of the first positioning portion 14A and the two side walls 14Ba, 14Ba of the other positioning portion 14B come into contact with each other, thus restricting circumferential displacement. When the sheet body 13 is restored to its original state, the first divided body 12A and the second divided body 12B are pressed against the outer peripheral wall 3d by the sheet body 13, thus restricting displacement in the groove width direction. Furthermore, if the pressure on the outer peripheral wall 3d is strong, the displacement in the depth direction will be restricted even if one of the positioning parts 14A is inserted with some play within the other positioning part 14B.

[0032] When one positioning section 14A and the other positioning section 14B are positioned facing each other within the cooling water flow path 3, the sheet body 13 expands and returns to its compressed state upon contact with the cooling water flowing through the cooling water flow path 3. Due to the expansion of the sheet body 13, one positioning section 14A, along with the first divided body 12A, is displaced toward the other positioning section 14B and guided into the other positioning section 14B. This guidance causes one positioning section 14A and the other positioning section 14B to engage with each other.

[0033] Thus, the spacer body 11 has a positioning structure that positions the relative positions of the first divided body 12A and the second divided body 12B. Since the multiple divided bodies 12 are positioned and engage with each other within the cooling water flow path 3, there is no need to pre-assemble the divided bodies 12 before placing them in the cooling water flow path 3. In addition, since the spacer 10 can be disassembled into the first divided body 12A and the second divided body 12B, the space required for transportation and storage can be reduced by stacking divided bodies of the same shape. When the spacer 10 is placed in the cooling water flow path 3, the relative position is positioned by the restoration of the sheet body 13, which causes one positioning portion 14A of the first divided body 12A to be displaced toward the other positioning portion 14B. Furthermore, since the sheet body 13 is provided so as to overlap one of the positioning portions 14A in the thickness direction of the first divided body 12A, the displacement of one of the positioning portions 14A in the thickness direction can be made more reliable. Therefore, positioning by the engagement of one positioning portion 14A and the other positioning portion 14B can be made more reliable.

[0034] In this embodiment, the spacer 10 positions the relative positions of the first divided body 12A and the second divided body 12B by the restoration of the sheet body 13, and the restoration of the sheet body 13 can regulate the flow rate and velocity of the cooling water flowing in the cooling water passage 3. This regulation optimizes the cooling of the cylinder bore 2. Furthermore, in the spacer 10 of this embodiment, the other surface 11b of the spacer body 11, which is opposite to the one surface 11a on which the sheet body 13 is provided, abuts against the outer peripheral wall 3d of the cooling water passage 3, thereby further regulating the flow of cooling water in the cooling water passage 3.

[0035] <Modified form of the first embodiment> Next, the first to third modifications of the first embodiment will be described with reference to Figures 5 to 7. Note that the configuration and effects of parts common to the first embodiment will be omitted. The spacer body 11 shown in Figures 5 to 7 is depicted in a non-curved configuration, but it may be formed with appropriate curvature to match the shape of the cooling water flow path 3. First, the modification shown in Figure 5 will be described. Figure 5(a) is a schematic perspective view showing the other side 11b of the spacer body 11, (b) is a schematic perspective view showing one side 11a of the spacer body 11, (c) is a schematic plan view, and (d) is a schematic cross-sectional view.

[0036] As shown in Figure 5(a), the first divided body 12A has three positioning portions 14A, which are recesses that match the other positioning portion 14B, spaced apart in the depth direction. Each positioning portion 14A is formed to penetrate in the thickness direction and is a frustoconical recess formed such that the diameter of the hole gradually decreases from one side to the other in the thickness direction.

[0037] The second divided body 12B has a stepped portion 125 formed on the side opposite to the first divided body 12A in the thickness direction, and as shown in Figure 5(c), the other positioning portion 14B is formed projecting in the thickness direction from the other surface 125b in the thickness direction of this stepped portion 125. As shown in Figure 5(a), there are three of the other positioning portions 14B, spaced apart in the depth direction. The other positioning portions 14B are formed projecting in a frustoconical shape that gradually tapers from one side to the other in the thickness direction. Also, as shown in Figures 5(b) and (d), the second divided body 12B has a sheet body 13 that is long in the depth direction on one surface 125a in the thickness direction of the stepped portion 125, so as to overlap the three other positioning portions 14B in the thickness direction.

[0038] As the sheet body 13 returns to its original position, the second divided body 12B is displaced toward the first divided body 12A, causing the other positioning part 14B to enter and engage with the other positioning part 14A, thereby positioning the relative positions of the first divided body 12A and the second divided body 12B. The first divided body 12A and the second divided body 12B have concave and convex shapes that match each other, and the surfaces that come into contact when engaged are formed to be inclined substantially parallel to each other. This allows them to be guided and positioned by the pressure exerted by the return of the sheet body 13. Furthermore, since there are three pairs of positioning parts 14A and positioning parts 14B, which is more than in the first embodiment, the first divided body 12A and the second divided body 12B are more firmly connected.

[0039] Furthermore, the pressing caused by the restoration of the sheet body 13 causes the other surfaces 12b, 12b in the thickness direction of the first divided body 12A and the second divided body 12B to come into contact with the outer peripheral wall 3d of the cooling water channel 3. As a result, the displacement in the thickness direction is restricted as the first divided body 12A and the second divided body 12B are sandwiched between the sheet body 13 and the outer peripheral wall 3d of the cooling water channel 3. In addition, the engagement of the first divided body 12A and the second divided body 12B causes the other surface 12b in the thickness direction of the first divided body 12A and the end surface 14Bb in the thickness direction of the other positioning portion 14B to be substantially flush.

[0040] As shown in Figure 5(d), when the spacer 10 of this embodiment is placed in the cooling water channel 3, the other surfaces 12b of the first divided body 12A and the second divided body 12B come into contact with the outer peripheral wall 3d of the cooling water channel 3, and the groove width of the cooling water channel 3 in the portion where the stepped portion 125 is located becomes smaller. The sheet body 13 provided on the stepped portion 125 comes into contact with the inner peripheral wall 3c of the cooling water channel 3. This makes it possible to regulate the flow rate and velocity of the cooling water flowing through the cooling water channel 3.

[0041] Next, a modified example shown in Figure 6 will be described. Figure 6(a) is a schematic perspective view showing one side of the spacer 10 in its disassembled state, (b) is a schematic perspective view showing the other side of the spacer 10 in (a), and (c) is a schematic cross-sectional view of the spacer 10 in the state in which the sheet body has been restored within the cooling water flow path 3.

[0042] The spacer 10 in Figure 6 comprises a first divided body 12A having one truncated square pyramidal positioning portion 14A protruding in the thickness direction, and a second divided body 12B having a concave positioning portion 14B that matches the shape of the first positioning portion 14A (see Figures 6(a) and 6(b)). The other positioning portion 14B is a truncated square pyramidal recess that is recessed to the extent that it does not penetrate the second divided body 12B. In addition, the second divided body 12B has a stepped portion 125 formed on the side opposite to the first divided body 12A in the thickness direction.

[0043] The first divided body 12A and the second divided body 12B are provided with sheet bodies 13A and 13B, respectively. Sheet body 13A is provided on substantially the entire thickness of one surface 12a of the first divided body 12A, and sheet body 13B is provided on the other surface 125b of the stepped portion 125 of the second divided body 12B so as to overlap with the other positioning portion 14B in the thickness direction.

[0044] When cooling water flows through the cooling water channel 3, as shown in Figure 6(c), the restored sheet bodies 13A and 13B press the first divided body 12A and the second divided body 12B away from the inner circumferential wall 3c and outer circumferential wall 3d of the cooling water channel 3. Since the first divided body 12A and the second divided body 12B are pressed from both sides in the thickness direction by the sheet bodies 13A and 13B, the displacement of their relative positions is restricted by this pressure. Even if there is only one pair of positioning parts 14A and 14B, fewer than in the first embodiment, they can engage with each other and be positioned by the pressure of the sheet bodies 13A and 13B.

[0045] Furthermore, the sheet body 13A that abuts the inner circumferential wall 3c of the cooling water channel 3 and the sheet body 13B that abuts the outer circumferential wall 3d can regulate the flow rate and velocity of the cooling water flowing through the cooling water channel 3. Since the sheet body 13B has smaller dimensions in the circumferential and depth directions, it tends to have a smaller effect in regulating the cooling water compared to the case where the first segment 12A and the second segment 12B abut the outer circumferential wall 3d. For this reason, it is more suitable when you want to flow more cooling water than when the first segment 12A and the second segment 12B abut the outer circumferential wall 3d.

[0046] Furthermore, the spacer 10 shown in Figure 7(a) is a further modification of the spacer 10 in Figure 6. Compared to the spacer in Figure 6, the spacer 10 in Figure 7(a) has larger dimensions in the depth direction and circumferential direction of one positioning portion 14A and the other positioning portion 14B. Moreover, unlike that in Figure 6, the other positioning portion 14B of the second divided body 12B penetrates the stepped portion 125 of the second divided body 12B in the thickness direction. On the other surface 125b of the stepped portion 125 of the second divided body 12B, a sheet body 13B is provided along the edge of the other positioning portion 14B. In this spacer 10 in Figure 7(a), the sheet body 13A may or may not be provided on the first divided body 12A. Also, although one positioning portion 14A is larger than that in Figure 6, it is similar to that in Figure 6 in that it protrudes in a truncated pyramidal shape. Furthermore, the other positioning portion 14B has a configuration that penetrates in the thickness direction, but it is a pyramidal recess, similar to that in Figure 6. The sheet body 13B is shaped to follow the edge of the other positioning portion 14B, and therefore has a hole that penetrates in the thickness direction in the center, but its external dimensions are larger than those of the sheet body 13B in Figure 6. As a result, the sheet body 13B in Figure 7(a) has a greater effect in restricting the flow of cooling water compared to the sheet body 13B in Figure 6.

[0047] Next, we will describe the modified examples shown in Figures 7(b) to 7(d). Figure 7(b) is a schematic perspective view showing one side 12a in the thickness direction of the first divided body 12A and the second divided body 12B in the spacer body 11 in its disassembled state, (c) is a schematic perspective view showing the other side 12b in the thickness direction of the first divided body 12A and the second divided body 12B in (b), and (d) is a schematic cross-sectional view of the spacer 10 in the state in which the sheet body has been restored in the cooling water flow path 3.

[0048] The spacer 10 shown in Figures 7(b) to 7(d) has a configuration in which the first divided body 12A is equipped with a sheet body 13 that is large enough to overlap one of the positioning portions 14A in the thickness direction, and the second divided body 12B is equipped with a sheet body 13. The first divided body 12A is equipped with one of the positioning portions 14A which is a pyramidal truncated shape and protrudes in the thickness direction on the other surface 12b in the thickness direction.

[0049] The second divided body 12B has a stepped portion 125 formed on the side opposite to the first divided body 12A in the thickness direction. One surface 125a of the stepped portion 125 in the thickness direction is provided with a concave positioning portion 14B that is recessed to the extent that it does not penetrate in the thickness direction. The shape of the recess of the other positioning portion 14B is substantially the same as the shape of the one positioning portion 14A.

[0050] Furthermore, four cylindrical portions 126 protruding in the thickness direction are provided on the other surface 125b of the stepped portion 125 of the second divided body 12B. As shown in Figure 7(d), when the sheet body 13 of the first divided body 12A expands, the cylindrical portions 126 come into contact with the outer peripheral wall 3d of the cooling water flow path 3, and the cylindrical portions 126 and the sheet body 13 are configured not to come into contact with the inner peripheral wall 3c and outer peripheral wall 3d of the cooling water flow path 3. A gap is created between the other surface 125b in the thickness direction of the stepped portion 125 and the outer peripheral wall 3d, so the cooling water flows through this gap, albeit restricted. As shown in Figure 7(d), the groove width of the cooling water flow path 3 is narrowed in the area where the stepped portion 125 is located, but the cooling water can still flow through the gap between the other surface 125b in the thickness direction of the stepped portion 125 and the outer peripheral wall 3d. Therefore, this configuration is suitable when it is desired to allow more cooling water to flow than in the first embodiment, while still restricting the flow of cooling water.

[0051] <Second Embodiment> Next, the spacer 10 according to the second embodiment will be described with reference to Figures 8 to 10. Note that the description of the configuration and effects of parts common to the first embodiment will be omitted. Figure 8(a) is a schematic perspective view showing the main part of the first divided body 12A, Figure 8(b) is a schematic perspective view showing the main part of the second divided body 12B, and (c) is a schematic perspective view showing the state in which the sheet body 13 is restored in the cooling water flow path 3 and the relative positions of the first divided body 12A and the second divided body 12B are positioned. Also, Figure 9(a) is a schematic side view showing the state in which the first divided body 12A and the second divided body 12B are arranged facing each other, (b) is a plan view of (a), (c) is a cross-sectional view taken along the line C-C' of (a), and (d) is a cross-sectional view taken along the line C-C' of (a) in the state in which the sheet bodies 13A and 13B are restored in the cooling water flow path 3. Figure 10(a) is a cross-sectional view taken along the line D-D' in Figure 9(c) within the cooling water flow path 3, (b) is a cross-sectional view taken along the line E-E' in Figure 9(d), and (c) is a schematic plan view to explain the effects of the separation restricting sections 15A and 15B. Note that in Figure 9(a), a spotted pattern has been added to the second segment 12B to distinguish it from the first segment 12A.

[0052] As shown in Figure 8(a), one positioning portion 14A is provided on the other circumferential side of the first divided body 12A. The one positioning portion 14A comprises a frame portion 141 that protrudes in a frame shape in the thickness direction from the other surface 12b, and a projection portion 142 that further protrudes in the thickness direction from the other circumferential end of the frame portion 141. Two projection portions 142 are formed with a gap between them in the depth direction, and are formed to protrude from the upper end and lower end of the other circumferential end of the frame portion 141, respectively. The gap between these projection portions 142, 142 is formed to be large enough for the connecting piece portion 144 of the other positioning portion 14B, which will be described later, to fit into.

[0053] Furthermore, as shown in Figures 9(a)(c) and 10, the frame portion 141 and the protruding portion 142 are inclined to gradually taper from one side to the other in the thickness direction. The inner wall surface 141a of the frame portion 141 is inclined so that the opening widens from one side to the other in the thickness direction, thus acting as a guide portion that guides the other positioning portion 14B when engaging with it. The surfaces of the protruding portions 142, 142 that face each other in the depth direction are also inclined to gradually taper from one side to the other in the thickness direction, thus acting as a guide portion for guiding the other positioning portion 14B.

[0054] In the first divided body 12A, a separation restricting portion 15A is provided at a position separated from one positioning portion 14A on the other side in the circumferential direction. The separation restricting portion 15A is formed on the upper side of the other end in the circumferential direction of the first divided body 12A. The separation restricting portion 15A includes an extension portion 151 extending to the other side in the circumferential direction and a projection portion 152 projecting from the other end in the circumferential direction of the extension portion 151 to the other side in the thickness direction. In the first divided body 12A, a sheet body 13A is provided on one surface 12a in the thickness direction of the main body portion 120A, overlapping with one positioning portion 14A in the thickness direction (see Figure 9(c)).

[0055] As shown in Figure 8(b), the second divided body 12B is provided with a positioning portion 14B and a separation restricting portion 15B at one end in the circumferential direction. The other positioning portion 14B and the separation restricting portion 15B are located on the other side in the thickness direction of the main body portion 120B of the second divided body 12B and are connected to the main body portion 120B by a connecting portion 123. This connecting portion 123 is formed inclined from one end in the circumferential direction of the main body portion 120B to the other side in the thickness direction. The connecting portion 123 has a depth dimension smaller than that of the main body portion 120B and is configured such that a protruding portion 152 is located above the connecting portion 123 when it engages with the first divided body 12A.

[0056] The other positioning portion 14B includes a trapezoidal portion 143 that fits into and engages with the frame portion 141, and a connecting piece portion 144 that connects the trapezoidal portion 143 to the second divided body 12B and fits into and engages between the protruding portions 142, 142. The trapezoidal portion 143 has a truncated square pyramidal shape that tapers to one side in the thickness direction, and is approximately the same shape as or smaller than the space inside the frame portion 141. The connecting piece portion 144 is formed with a depth dimension approximately the same as or smaller than the dimension between the protruding portions 142, 142.

[0057] A separation restricting portion 15B is provided adjacent to the connecting piece portion 144. The separation restricting portion 15B is located above the connecting piece portion 144 in the depth direction and is formed to protrude to one side in the thickness direction. The surface of the separation restricting portion 15B facing the trapezoidal portion 143 in the circumferential direction is formed at an inclination, and in cooperation with the trapezoidal portion 143, the upper protruding portion 142 can be guided into the space between the separation restricting portion 15B and the trapezoidal portion 143. In the second divided body 12B, a sheet body 13B is provided on one surface 12a in the thickness direction of the main body portion 120B, and this sheet body 13B is provided so as not to overlap with the other positioning portion 14B, separation restricting portion 15B and connecting portion 123 in the thickness direction.

[0058] As shown in Figures 9(a) to (c), the first divided body 12A and the second divided body 12B can be positioned facing each other without one positioning part 14A and the other positioning part 14B engaging. The sheet bodies 13A and 13B expand and return to their original size upon contact with the cooling water flowing in the cooling water channel 3, pressing the first divided body 12A and the second divided body 12B against the outer peripheral wall 3d of the cooling water channel 3. As a result, one positioning part 14A and the other positioning part 14B are displaced and engage with each other, thereby positioning the relative positions of the first divided body 12A and the second divided body 12B.

[0059] When positioning, even if the first divided body 12A and the second divided body 12B are positioned slightly misaligned, one positioning section 14A and the other positioning section 14B are equipped with inclined surfaces to guide each other to the appropriate position. The inner wall surface 141a of the frame section 141 of the one positioning section 14A is inclined such that the opening gradually increases from one side to the other in the thickness direction. The trapezoidal section 143 of the other positioning section 14B is inclined so that it gradually tapers from the other side to the one side in the thickness direction. The frame section 141 and the trapezoidal section 143 are concave and convex sections with matching shapes. Therefore, when the sheet bodies 13A and 13B are restored from the state shown in Figure 9(c) where they are separated and facing each other in the thickness direction, the inclination of the frame section 141 and the inclination of the trapezoidal section 143 can guide them to the appropriate relative position in the circumferential direction, as shown in Figure 9(d).

[0060] Furthermore, as shown in Figure 10(a), the upper and lower surfaces of one positioning section 14A and the other positioning section 14B are also inclined. Therefore, even if the first divided body 12A and the second divided body 12B are misaligned in the depth direction, they can be guided to the appropriate relative position in the depth direction, as shown in Figure 10(b). In addition, in this embodiment, the trapezoidal section 143 fits into the frame section 141 with virtually no gap and is engaged, so the relative displacement of the first divided body 12A and the second divided body 12B in the depth direction, circumferential direction and groove width direction in the cooling water flow path 3 can be restricted. Also, because the trapezoidal section 143 fits into the frame section 141 with virtually no gap and is engaged, the positioning accuracy of the relative position is improved.

[0061] Furthermore, when the separation restricting parts 15A and 15B are positioned within the cooling water flow path 3, they engage with each other, thereby restricting the displacement of adjacent positioning parts 14A and 14B in the direction of separation. As shown in Figure 10(c), even if the restorative balance of the sheet body 13A and sheet body 13B is disrupted and the positioning parts 14A and 14B are displaced in the direction of separation in the circumferential direction before they engage with each other, the separation restricting parts 15A and 15B restrict them from separating to a position where they can no longer engage with each other.

[0062] The separation restricting parts 15A and 15B restrict the separation of the positioning parts 14A and 14B to a position where they cannot engage with each other. Therefore, even if the restorative balance of the sheet body 13A and sheet body 13B is disrupted, the positioning parts 14A and 14B will not separate but will engage with each other. This determines the relative positions of the first divided body 12A and the second divided body 12B. Depending on the width of the groove in the cooling water flow path 3, there is a risk that the separation restricting part 15A and the connection part 123 may interfere when placed in the cooling water flow path 3. Therefore, it is preferable to place the first divided body 12A after placing the second divided body 12B.

[0063] Furthermore, as shown in Figure 9(d), the other positioning part 14B abuts against the outer peripheral wall 3d of the cooling water channel 3. When the other positioning part 14B abuts against the outer peripheral wall 3d of the cooling water channel 3, the separation restricting parts 15A, 15B and the connecting part 123 are arranged along the groove width direction of the cooling water channel 3, so the separation restricting parts 15A, 15B and the connecting part 123 act as obstacles to restrict the flow rate and velocity of the cooling water.

[0064] <Modified form of the second embodiment> Next, a modified example of the second embodiment will be described with reference to Figures 11 to 13. Note that the explanation of the configuration and effects of parts common to the second embodiment will be omitted. The spacer body 11 shown in Figures 12 and 13 is illustrated as a non-curved configuration, but it may be formed with an appropriate curve to match the shape of the cooling water flow path 3. First, the modified example shown in Figures 11(a) and 11(b) will be described.

[0065] In Figures 11(a) and 11(b), one positioning portion 14A is provided at the other end of the first divided body 12A in the circumferential direction. The one positioning portion 14A has a trapezoidal portion 143 in the shape of a pyramidal

[0066] In Figures 11(a) and 11(b), the other positioning portion 14B is provided at one end of the second divided body 12B in the circumferential direction. The other positioning portion 14B comprises a frame portion 141 that protrudes in a frame shape in the thickness direction from one surface 12a of the main body portion 120B, and a projection portion 142 that further protrudes in the thickness direction from one end of the frame portion 141 in the circumferential direction. Two projection portions 142 are formed on the frame portion 141 with a gap between them in the depth direction, and are formed protruding from the upper and lower ends of one end of the frame portion 141 in the circumferential direction, respectively. These projection portions 142, 142 are separated vertically with a gap between them.

[0067] As shown in Figures 11(a) and 11(b), the spacer 10 has a sheet body 13 provided on one surface 12a such that it overlaps with one positioning portion 14A in the thickness direction. Figure 11(b) schematically shows the intermediate state in which the sheet body 13 returns to its original position and the positioning portions 14A and 14B engage with each other. As the sheet body 13 returns to its original position, the first divided portion 12A is displaced in the thickness direction toward the second divided portion 12B. The connecting piece 144 of one positioning portion 14A engages between the protrusions 142, 142 of the other positioning portion 14B, and the trapezoidal portion 143 of one positioning portion 14A engages within the frame portion 141 of the other positioning portion 14B. Then, as the sheet body 13 returns to its original position, the plate portion 145 of one positioning portion 14A comes into contact with the frame portion 141 of the other positioning portion 14B.

[0068] The engagement of the positioning parts 14A and 14B restricts the relative positional displacement of the first divided body 12A and the second divided body 12B in the depth direction, circumferential direction, and groove width direction within the cooling water flow path 3. Furthermore, since no separation restricting part is provided in this modified example, the order in which the first divided body 12A and the second divided body 12B are placed within the cooling water flow path 3 does not need to be considered.

[0069] Next, a modified example shown in Figures 11(c) and 11(d) will be described. As shown in Figure 11(c), two positioning portions 14A are provided on one surface 12a of the first divided body 12A, spaced apart in the depth direction, and each has a shape that protrudes to one side in the thickness direction. The two positioning portions 14A, 14A have inclined surfaces on the surfaces facing each other in the depth direction, which allows the other positioning portion 14B to be guided between the two positioning portions 14A, 14A.

[0070] Furthermore, the other positioning portion 14B protrudes from one surface 12a of the main body portion 120B to one side in the thickness direction by the same dimension as the protrusion of the positioning portion 14A, and also protrudes in the circumferential direction. The upper and lower surfaces of the other positioning portion 14B in the depth direction are inclined to taper toward the other side in the thickness direction. The other positioning portion 14B is formed in a shape that fits into the space between the two positioning portions 14A.

[0071] In the spacer 10 shown in Figures 11(c) and 11(d), the sheet body 13 is provided on the other surface 12b in the thickness direction of the first divided body 12A. The sheet body 13 is positioned so as to overlap one of the positioning parts 14A, 14A in the thickness direction, and its dimension in the depth direction is formed to be larger than the dimension between the two positioning parts 14A, 14A. When the sheet body 13 expands as it returns to its original shape, the first divided body 12A is displaced toward the second divided body 12B, and one positioning part 14A and the other positioning part 14B engage. This positions the relative positions of the first divided body 12A and the second divided body 12B. Note that the positioning parts 14A and 14B are structured to position the depth direction by the inclined surface of the depth direction, but they are not structured to position the circumferential direction. Even if the positioning structure does not perform circumferential positioning, the circumferential displacement is restricted because the enlarged sheet body 13 presses the spacer body 11 against the inner circumferential wall 3c of the cooling water flow path 3.

[0072] In another modified configuration, the positioning parts 14A and 14B abut against the inner circumferential wall 3c of the cooling water flow path 3, and the sheet body 13 abuts against the outer circumferential wall 3d. Therefore, the flow rate and velocity of the cooling water can be regulated in the area where the positioning parts 14A and 14B and the sheet body 13 are located.

[0073] Next, the spacer 10 in Figure 12 will be described. As shown in Figure 12(a), the first divided body 12A is provided with one positioning portion 14A that protrudes from the other surface 12b in the thickness direction so as to taper. On one surface 12a of the first divided body 12A, a sheet body 13 is provided so as to overlap with the positioning portion 14A in the thickness direction.

[0074] As shown in Figures 12(a) and 12(b), one end of the main body portion 120B of the second divided body 12B is shaped as a bifurcated section extending in the circumferential direction when viewed from above, and this bifurcated section is referred to as the bifurcated portion 127. One of the bifurcated portions 127A of this bifurcated portion 127 has a hole that penetrates in the thickness direction, and this hole serves as the other positioning portion 14B. The other positioning portion 14B is a square pyramidal hole that is inclined so that the hole gradually becomes smaller from one side to the other in the thickness direction.

[0075] When the spacer 10 shown in Figure 12 is placed in the cooling water channel 3, the positioning portion 14A of the first divided body 12A is positioned between one branch 127A and the other branch 127B of the bifurcated portion 127 (see Figure 12(b)). Then, as the cooling water flows into the cooling water channel 3, the sheet body 13 of the first divided body 12A returns to its original position and comes into contact with the other branch 127B of the bifurcated portion 127 of the second divided body 12B. The sheet body 13 coming into contact with the other branch 127B displaces the first divided body 12A, causing one positioning portion 14A to enter the other positioning portion 14B, thereby positioning the relative positions of the first divided body 12A and the second divided body 12B.

[0076] In this modified example, the spacer 10 is not pressed against the inner circumferential wall 3c or outer circumferential wall 3d of the cooling water passage 3 when the sheet body 13 is restored. In the area where the bifurcated portion 127 is located, the groove width of the cooling water passage 3 is narrowed, restricting the flow rate and velocity of the cooling water, but the cooling water flows through the space between the bifurcated portion 127 and the inner circumferential wall 3c and outer circumferential wall 3d of the cooling water passage 3. Therefore, this modified example is suitable when it is desired to allow cooling water to flow through the inner circumferential wall 3c and outer circumferential wall 3d of the cooling water passage 3.

[0077] Next, the spacer 10 shown in Figure 13 will be described. The first divided body 12A shown in Figure 13(a) has three positioning portions 14A arranged in a line with spacing in the depth direction. Each positioning portion 14A is formed in a hemispherical shape and protrudes in the thickness direction from one surface 12a of the main body portion 120A of the first divided body 12A.

[0078] The second segment 12B shown in Figure 13(b) has a stepped portion 125 on one side in the thickness direction, and three other positioning portions 14B are formed on this stepped portion 125, spaced apart in the depth direction. The thickness of the stepped portion 125 is larger than the thickness dimension of one of the positioning portions 14A. The other positioning portion 14B is a recess that penetrates in the thickness direction, and one of the positioning portions 14A is housed within the other positioning portion 14B during positioning.

[0079] In the spacer 10 shown in Figure 13, the second divided body 12B is equipped with a sheet body 13, while the first divided body 12A is not equipped with a sheet body. The sheet body 13 is provided so as to cover the entire surface on one side in the thickness direction of the stepped portion 125 of the second divided body 12B. Therefore, the sheet body 13 covers one side of the opening of the other positioning portion 14B, and as shown in Figure 13(d), when the sheet body 13 is restored to its original position, a part of the sheet body 13 enters the other positioning portion 14B.

[0080] <Third Embodiment> Next, the spacer 10 of the third embodiment will be described with reference to Figures 14 and 15. The explanation of the configuration and effects of parts common to the first embodiment will be omitted. In Figures 14(a) and 14(b), the right side is the first divided body 12A, and the left side is the second divided body 12B. Figure 14(c) is a schematic side view of one side 12a in the thickness direction of the second divided body 12B, and Figure 14(d) is a schematic side view of the other side 12b in the thickness direction of the first divided body 12A. Furthermore, in the third embodiment, as in the first embodiment, the side where the first divided body 12A is located is one side in the circumferential direction of the cooling water flow path 3, and the side where the second divided body 12B is located is the other side in the circumferential direction of the cooling water flow path 3. That is, in Figures 14(a) and 14(b), the right side of the paper is one side in the circumferential direction, and the opposite direction is the other side. Figure 14(c) is a schematic side view of the other segment in the view along line F in (a), and (d) is a schematic side view of one of the segments in the view along line G in (a).

[0081] The spacer 10 of the third embodiment is positioned in the cooling water passage 3 of an internal combustion engine 4 having three cylinder bores 2, similar to the first embodiment. When the spacer 10 is positioned in the cooling water passage 3, one positioning part 14A and the other positioning part 14B are positioned approximately at the circumferential center of the arc-shaped portion 3a of the cooling water passage 3 along the third cylinder bore 2. The first divided body 12A and the second divided body 12B are each configured to include sheet bodies 13A and 13B.

[0082] One positioning portion 14A, located on the other circumferential side of the first divided body 12A, is formed to protrude in the thickness direction from the other surface 12b in the thickness direction of the main body 120A (see Figures 14(a) and 14(d)). One positioning portion 14A has three recessed portions 146, which are arc-shaped when viewed from the side, spaced apart in the depth direction on one circumferential side surface. The recessed portions 146 are recessed in the circumferential direction and open to the other side in the thickness direction.

[0083] The second divided body 12B has a stepped portion 125 formed in the thickness direction from one end of the main body 120B in the circumferential direction, and the other positioning portion 14B is formed protruding in the thickness direction from one surface of the stepped portion 125 in the thickness direction (see Figures 14(a) and (c)). The other positioning portion 14B has three protruding portions 147 that protrude in an arc shape when viewed from the side in the circumferential direction, spaced apart in the depth direction. The other surface of the protruding portions 147 in the thickness direction is flat. When the spacer 10 is placed in the cooling water flow path 3, one positioning portion 14A is positioned in the space between the one end of the main body 120B in the circumferential direction, the stepped portion 125, and the other positioning portion 14B.

[0084] The first segment 12A and the second segment 12B are provided with sheet bodies 13A and 13B respectively, so that they face each other via the cylinder bore 2 when placed in the cooling water passage 3. Therefore, when cooling water flows into the cooling water passage 3 and the sheet bodies 13A and 13B expand and return to their original size, the first segment 12A and the second segment 12B are displaced in directions that separate them from each other. In the plane of Figures 14(a)(b) and 15, the first segment 12A is displaced to the right and the second segment 12B is displaced to the left.

[0085] One positioning portion 14A is positioned in the space between the step portion 125 and the other positioning portion 14B of the main body portion 120B of the second divided body 12B. As a result, when the sheet bodies 13A and 13B are restored, the recessed portion 146 of one positioning portion 14A and the protruding portion 147 of the other positioning portion 14B are displaced to move closer together, and eventually the protruding portion 147 enters the recessed portion 146 and engages with it. At this time, even if there is a misalignment in the depth direction between the recessed portion 146 and the protruding portion 147, as shown in Figures 15(a) to (c), a part of the protruding portion 147 comes into contact with the curved edge of the recessed portion 146, guiding the protruding portion 147 into the recessed portion 146 and correcting the misalignment in the depth direction.

[0086] Furthermore, as shown in the modified example in Figure 16(a), the recessed portion 146 of one positioning portion 14A may be configured such that the other side in the thickness direction is not open. As a result, when the protruding portion 147 of the other positioning portion 14B in Figure 16(b) enters the recessed portion 146, the relative displacement in the thickness direction of the first divided body 12A and the second divided body 12B is restricted even before they come into contact with the outer peripheral wall 3d of the cooling water flow path 3. In addition, as the sheet bodies 13A and 13B return to their original state, the stepped portion 125 of the second divided body 12B comes into contact with the outer peripheral wall 3d of the cooling water flow path 3, thereby regulating the flow rate and velocity of the cooling water.

[0087] The configuration of each spacer 10 described above is not limited to those shown in the illustration. For example, the number of divided bodies 12 constituting the spacer 10 is not limited to two, and the spacer 10 may be composed of many more divided bodies 12. In that case, each divided body 12 may be provided with a positioning structure by a positioning part for positioning the relative positions of adjacent divided bodies 12. The sheet body 13 is not limited to a cellulose sponge, but may be a rubber foam or synthetic resin foam compressed with a water-soluble or heat-meltable binder, or it may have various other configurations. The shape of each positioning part 14A, 14B is not limited to those shown in the illustration, nor is it limited to an uneven structure with recesses and protrusions that engage with each other. The separation restricting parts 15A, 15B are also not limited to the shapes shown, and a spacer 10 in an embodiment without separation restricting parts 15A, 15B may also be provided with separation restricting parts 15A, 15B. Furthermore, the spacer 10 is not limited to being placed within the cooling water passage 3 of the three-cylinder cylinder bore 2; the spacer body 11 can be formed to match the shape of the cooling water passage 3 in which it is placed. The spacer 10 can be formed into various shapes depending on the desired regulation of the flow rate and velocity of the cooling water. [Explanation of Symbols]

[0088] 1 Cylinder Block 2 Cylinder bore 3 Cooling water flow path 3c Inner wall 3d outer wall 4. Internal combustion engine 10 Spacers 11 Spacer body 11a One side 11b Other side 12,12A,12B split body 12a One side 12b Other side 13, 13A, 13B Sheet Body 14A, 14B Positioning section 15A,15B Separation regulation part

Claims

1. A spacer that is placed in a cooling water passage surrounding the cylinder bore of the cylinder block of an internal combustion engine, and which restricts the flow of cooling water, The spacer body is configured to conform to the shape of the cylinder bore by combining a plurality of rigid segmented bodies, and the porous sheet body has the characteristic of expanding in the thickness direction and recovering from a compressed state upon contact with the cooling water, which is a predetermined external factor. Each of the plurality of divided bodies is provided with a positioning portion that can engage with an adjacent divided body, and at least one of the adjacent divided bodies is provided with the sheet body in a compressed state on one side. The spacer body is characterized by having a positioning structure in which, when the positioning portions of one divided body and the other divided body are arranged facing each other in the cooling water flow path, the positioning portion of one divided body is displaced when the sheet body is restored from a compressed state and engages with the positioning portion of the other divided body, thereby positioning the relative position of one divided body and the other divided body.

2. In claim 1, The positioning structure is characterized by being a spacer that restricts the relative displacement of the plurality of divided bodies in the depth direction, circumferential direction, and groove width direction in the cooling water flow path when adjacent positioning parts are engaged with each other.

3. In claim 1 or claim 2, The positioning structure is characterized by a spacer having an uneven structure with mutually engaging recesses and protrusions.

4. In claim 1 or claim 2, The spacer is characterized in that the divided body is provided with separation restricting portions that, when placed in the cooling water flow path, engage with each other to restrict circumferential displacement within the cooling water flow path, thereby separating adjacent positioning portions.

5. In claim 1 or claim 2, The spacer body is characterized in that the other side, which is the side opposite to the one side on which the sheet body is provided, abuts against the wall surface of the cooling water channel.

6. In claim 1 or claim 2, The spacer is characterized in that the sheet body is provided at a position overlapping with the positioning portion in the thickness direction of the divided body.

Images