JP7340239B2 - Spacer manufacturing method and spacer - Google Patents

Description

The present invention relates to a method for manufacturing a spacer and a spacer arranged in a cooling water passage provided in a cylinder block of an internal combustion engine so as to surround a cylinder bore.

A spacer is arranged in a cooling water passage provided in a cylinder block of an internal combustion engine to regulate the flow (flow rate, flow velocity, etc.) of the cooling water flowing through the cooling water passage. When inserting and assembling the spacer into the cooling water flow path, it is desirable to eliminate insertion load and improve assemblability. Therefore, as a spacer that takes into consideration the ease of assembly as described above, there is a spacer disclosed in Patent Document 1 below. Further, Patent Document 1 can be cited as a conventional method for manufacturing a composite molded product having a sheet-like foam and a resin molded product.

Patent Document 1 listed below discloses a spacer including a spacer body and a foam attached to the inner surface of the spacer body, and a method for manufacturing the spacer. When the spacer described here is assembled into the cooling water flow path, the foam is in a compressed state, and after assembly, when a predetermined external factor such as cooling water is added, the foam becomes compressed. Configured to restore to a previous state. Furthermore, in Patent Document 1, a foam is formed with a through hole, the foam is positioned by fitting into a protrusion of a lower mold, and then a molten resin is injected to mold the foam and a polymer material. A method for manufacturing a composite molded article having the following is described (see Patent Document 1, FIG. 14, etc.).

Japanese Patent Application Publication No. 2016-128256

When molding a spacer with foam in this way, the protrusions of the mold are fitted together in order to position the foam so that it will not shift even when subjected to injection pressure during injection molding. It is necessary to provide through holes in the foam. However, when a through hole is provided in a foam, the restorable area of the foam decreases because the hole becomes an area that cannot be restored. Furthermore, as disclosed in Patent Document 1, when molten resin is injected toward a foam placed so as to overlap the resin injection part, the molten resin tends to seep into the foam, so It may not be restored.

The present invention has been made in view of the above circumstances, and aims to provide a method for manufacturing a spacer and a spacer that can alleviate the decrease in the restoring area of the porous body while suppressing the displacement of the porous body. The purpose is

A method for manufacturing a spacer according to the present invention is a method for manufacturing a spacer that is disposed in a cooling water flow path provided in a cylinder block of an internal combustion engine so as to surround a cylinder bore, and the spacer is manufactured by adding a predetermined external factor. A processing step of forming a recess in the porous body which is expanded and restored to its pre-compression state, and a process of positioning the porous body by inserting the recess into a positioning protrusion provided on the mold, followed by melting. and a molding step of injecting a resin into a cavity of the mold, and the positioning protrusion is provided at a position facing a resin injection part that introduces molten resin into the cavity. .

Further, the spacer according to the present invention is arranged in a cooling water flow path provided in a cylinder block of an internal combustion engine so as to surround a cylinder bore, and includes a molded body made of resin and a porous body integrally fixed to the molded body. A spacer comprising: a molded body having a resin introduction part which is an introduction part for molten resin during injection molding and is provided at a position overlapping with the porous body; and a spacer provided on the inner or outer surface of the molded body. and a porous body that is capable of retaining at least a part of the compressed state and has the property of restoring to the state before compression and expanding when a predetermined external factor is applied, The porous body is provided with a recess into which a positioning protrusion for positioning the porous body in the mold is inserted when insert molding the porous body and the molded body, and the recess and the resin The introduction section is characterized in that it is arranged so as to overlap in the compression direction of the porous body.

The spacer manufacturing method and spacer according to the present invention can suppress the displacement of the porous body and reduce the reduction in the restoring area of the porous body.

(a) is a schematic perspective view showing an example of a spacer manufactured by the manufacturing method according to the first embodiment of the present invention, and (b) is a schematic perspective cross-sectional view of a mold used in the manufacturing method. (a) and (b) are diagrams schematically showing a method for manufacturing a spacer according to a first embodiment, and (a) shows a step of placing a compressed porous body in the same mold. FIG. 5B is a diagram showing a step of insert molding the same porous body and resin. (a) is a schematic cross-sectional view showing the spacer obtained by demolding from the same mold (XX cross-sectional view of FIG. FIG. 2 is a schematic cross-sectional view showing a mounted state in which the porous body is enlarged. (a) is a schematic cross-sectional view showing one manufacturing process of a spacer manufactured by the manufacturing method according to the second embodiment of the present invention, and (b) is a schematic perspective cross-sectional view of a mold used in the manufacturing method. be.

The manufacturing method according to the present embodiment relates to a method for manufacturing a spacer 5 disposed in a cooling water passage 3 provided in a cylinder block 1 of an internal combustion engine (not shown) such as an automobile engine so as to surround a cylinder bore 2.
The method for manufacturing the spacer 5 according to the present embodiment includes at least a processing step of forming a recess 70 in the porous body 7 and a molding step of integrally molding the resin molded body 6 onto the porous body 7.
In the processing step, a concave portion 70 is formed in the porous body 7, which is expanded and restored to its pre-compression state in response to the addition of a predetermined external factor. In the molding process, after positioning the porous body 7 by inserting the recess 70 of the porous body 7 into the positioning protrusion 110 provided on the mold 100, molten resin is injected into the cavity 102 of the mold 100. . The positioning protrusion 110 is provided at a position facing a resin injection section 120 that introduces molten resin into the cavity 102.
This will be explained below with reference to the drawings. Note that in some of the figures, some detailed symbols attached to other figures are omitted.

<First embodiment>
First, a method for manufacturing the spacer 5 according to the first embodiment will be described with reference to FIGS. 1 to 3.
As described above, the spacer 5 manufactured by the manufacturing method according to the first embodiment is placed in the cooling water flow path 3 provided in the cylinder block 1 of an internal combustion engine such as an automobile engine, and is This is to prevent overcooling by regulating the flow of cooling water that cools the cylinder bore wall 20, which is increasing in temperature (see FIG. 3(b)). Here, as the spacer 5, a partial spacer partially disposed at a proper position within the cooling water flow path 3 is shown as an example. The spacer 5 includes a molded body 6 made of synthetic resin and a porous body 7 that is integrally insert-molded on the inner surface 6a of the molded body 6.

The resin used for the molded body 6 is not particularly limited, and for example, thermoplastic resins such as polyethylene, polypropylene, ABS, acrylic, polycarbonate, polyamide, polyacetal, polyphenylene sulfide, and polyether ether ketone are preferable. Furthermore, the synthetic resin may be one to which various additives have been added, or may be a fiber-reinforced resin containing reinforcing fibers such as carbon fibers and glass fibers.

The porous body 7 changes from the compressed state triggered by the addition of a predetermined external factor to the width direction a of the groove-shaped cooling water flow path 3 (white arrow in FIG. 3(b), width direction a). (see) has the characteristic of increasing in size. As shown in FIG. 1(a), the porous body 7 is rectangular and flexible in the form of a sheet when viewed from the front. The porous body 7 is not particularly limited as long as it has the above characteristics, but for example, a cellulose sponge is used. When a cellulose sponge is dried under pressure, the cellulose molecules form hydrogen bonds and are maintained in a compressed state. However, when exposed to moisture from this state, the water molecules dissociate the hydrogen bonds between the cellulose molecules. It is suitable as the porous body 7 because it has the property of recovering from a compressed state. In this case, the predetermined external factor is cooling water, and when the cooling water comes into contact with the porous body 7, an external factor is added to the porous body 7, and the porous body 7 is affected by the cooling water flow. The width of the passageway 3 increases in the width direction a.

<Manufacturing method>
<Processing process>
First, a processing step for processing the porous body 7 is performed. In the processing step, a porous body 7 is prepared and cut into a predetermined shape, and a recess 70 is formed at a predetermined position. At this time, the porous body 7 used is one that has already been compressed and processed to maintain that state, and one that is in a state before being restored. The illustrated porous body 7 is cut into a rectangular shape when viewed from the front, and a circular through hole penetrating the porous body 7 is formed as a recess 70 approximately in the center thereof. This recess 70 is formed at a position assuming that resin is integrally molded with the recess 70 inserted into a positioning protrusion 110 formed on a lower die 101, which will be described later. The size and shape of the recess 70 are formed to match the size and shape of the positioning protrusion 110.

<Molding process>
Next, a molding process is performed. In the molding process, after positioning the porous body 7 by inserting the recess 70 of the porous body 7 into the positioning protrusion 110 provided on the mold 100, the molten resin 8 is injected from the resin injection section 120 into the cavity 102 of the mold 100. The molded resin body 6 is integrally injected into the porous body 7. The positioning protrusion 110 is formed so that its protrusion amount is larger than the depth dimension of the recess 70 of the porous body 7, and when inserted into the recess 70 of the porous body 7, its tip surface 110a is located closer to the resin injection section 120 than the porous body 7. The positioning protrusion 110 is provided at a position facing a resin injection section 120 that introduces molten resin into the cavity 102. Further, it is desirable that the tip end surface 110a of the positioning protrusion 110 be a substantially horizontal flat surface, and be formed so that the tip end surface 110a overlaps the entire opening of the resin injection section 120. More specifically, as shown in FIG. 2(b), it is desirable that the diameter d1 of the distal end surface 110a of the positioning protrusion 110 is larger than the diameter d2 of the resin injection part 120 (d1>d2). In this case, the entire surface of the tip surface 110a of the positioning protrusion 110 receives the injection pressure of the molten resin 8, and then the molten resin 8 spreads into the cavity 102, so that the function of guiding the flow of the molten resin 8 is actively exerted. can be done.

A mold 100 is used in the molding process. As shown in FIG. 1(b) and the like, the mold 100 has a lower mold 101 and an upper mold 103, and when the molds are clamped, an arc-shaped cavity 102 that imitates the molded body 6 of the spacer 5 is defined. The cavity 102 is composed of a convexly curved lower mold cavity 101a and an upper mold cavity 103a. A positioning protrusion 110 through which the recess 70 of the porous body 7 is inserted is provided at the most protruding arc-shaped portion of the lower mold cavity 101a, in other words, at the top 101b of the convex curved surface of the lower mold cavity 101a (see FIG. 1(b)). It is formed to protrude toward the upper mold 103. The upper mold cavity 103a has a holding pin 130 that serves as a holding member for the porous body 7, and a resin injection part 120 that serves as a gate for introducing the molten resin 8 into the cavity 102. As described above, the resin injection part 120 is provided facing the positioning protrusion 110, and in the illustrated example, the positioning protrusion 110 is provided directly below the resin injection part 120.

The recess 70 of the porous body 7 is fitted into the positioning protrusion 110 of the lower die 101 to position the porous body 7 (see FIG. 2(a)). Thereafter, the upper mold 103 is clamped to the lower mold 101, and the molten resin 8 is injected from the resin injection section 120 (see FIG. 2(b)). At this time, when the upper mold 103 is clamped to the lower mold 101, the presser pins 130 come into contact with the lower mold 101 via the porous body 7, and press the porous body 7. As a result, the porous body 7 is deformed into an arc shape along the shape of the lower mold cavity 101a. In this state, the molten resin 8 is injected from the resin injection section 120 into the cavity 102 for insert molding.

When the molten resin 8 is injected from the resin injection part 120, the porous body 7 is subjected to high injection pressure, but the porous body 7 is held with the recess 70 passing through the positioning protrusion 110 and is held down by the lower mold 101 with the presser pin 130. Since the porous body 7 is attached, insert molding can be performed without shifting the position of the porous body 7. Further, at this time, the resin injection part 120 and the positioning protrusion 110 are arranged to face each other. Therefore, after the molten resin 8 injected from the resin injection part 120 reaches the tip surface 110a of the positioning protrusion 110, it is filled into the cavity 102 (see arrows b1 and b2 in FIG. 2(b)). The molten resin 8 spreads over the entire area inside the cavity 102, and is then cooled under pressure to solidify the resin, and the mold is opened and demolded. After demolding, the remaining portion 120a of the gate injected from the resin injection part 120 is cut as shown in FIG. 3(a) to obtain the spacer 5 shown in FIG. 3(a).

Here, a resin introducing portion 60 is formed at the cut site of the gate remaining portion 120a. This resin introduction part 60 is an introduction site for the molten resin 8 during injection molding, and is provided at a position overlapping with the porous body 7. Therefore, in the spacer 5 which is a completed product, the recess 70 and the resin introduction part 60 are arranged so as to overlap in the compression direction of the porous body 7. Furthermore, a molded body recess 61 formed by a positioning protrusion 110 is formed in the molded body 6 of the illustrated example.

According to the above, since the resin injection part 120 and the positioning protrusion 110 are arranged to face each other, the regions of the porous body 7 that are not restored overlap. In other words, it is inevitable to form the recesses 70 in order to prevent the porous body 7 from shifting its position. In addition, since the injection pressure is high directly below the resin injection part 120, the resin may seep into the porous body 7, resulting in an area where the resin does not recover. However, if the resin injection part 120 and the positioning protrusion 110 are arranged to face each other as described above, it is possible to consolidate (overlap) the unrestored areas of the porous body 7 that are inevitably formed. Although the porous body 7 has a positionable structure, it is possible to alleviate the reduction in the restoring area of the porous body 7. Furthermore, when it becomes necessary to reduce the size of the porous body 7 due to manufacturing or economical reasons, conventionally, the position where the positioning protrusion 110 is inserted and the position where the resin injection part 120 faces the porous body 7 It was necessary to secure each separately. However, according to the present embodiment, the location where the positioning protrusion 110 is inserted and the location where the resin injection part 120 faces can be combined, so the porous body 7 can be further reduced in size as required.

In addition, the porous body 7 is positioned by fitting the recess 70 and the positioning protrusion 110 and is held down by the holding pin 130, so that the porous body 7 is not moved or rolled up by injection pressure or the like. Can be insert molded. Furthermore, when the molten resin 8 is injected from the resin injection part 120, the molten resin 8 reaches the tip surface 110a of the positioning protrusion 110, and then spreads into the cavity 102 (see arrows b1 and b2 in FIG. 2(b)). ). Therefore, the injection pressure of the molten resin 8 can be relaxed before the molten resin 8 reaches the porous body 7, and the amount of the molten resin 8 that permeates into the porous body 7 can be reduced.

In the spacer 5 obtained by the above manufacturing method, as shown in FIG. It is located. That is, when insert molding the porous body 7 and molded body 6 of this spacer 5, the resin injection part 120 and the positioning protrusion 110 face each other as shown in FIGS. 1(b) and 2(b). It becomes like this. Therefore, in the spacer 5 obtained by the above manufacturing method, the restoration of the porous body 7 as a whole is better than a spacer in which the resin introduction part 60 of the molded body 6 and the recess 70 of the porous body 7 do not overlap in the compression direction. The area can be increased and the flow of cooling water can be regulated as desired.

<About usage conditions>
The spacer 5 manufactured by the above manufacturing method is used as follows. The spacer 5 is formed in an arcuate shape along the arcuate portion 3a of the cooling water flow path 3. When the spacer 5 is arranged and assembled in the cooling water flow path 3, the porous body 7 is in a compressed state as shown in FIG. It is in. Therefore, when the spacer 5 is assembled into the cooling water passage 3, the spacer 5 can be smoothly assembled without interfering with the inner wall surface 30 and the outer wall surface 31 of the cooling water passage 3. On the other hand, after the spacer 5 is assembled into the cooling water flow path 3, the porous body 7 comes into contact with the cooling water flowing through the cooling water flow path 3, as shown in FIG. become When the porous body 7 expands, one side 71 of the expanded porous body 7 comes into contact with the inner wall surface 30. Then, the cooling water on the inner wall surface 30 side is dammed up, making it difficult for the cooling water to flow through the portion of the cooling water flow path 3 where the spacer 5 is arranged, and the spacer 5 installed in the cooling water flow path 3 prevents overcooling, etc. It can be prevented.

<Second embodiment>
Next, a second embodiment will be described as a modification of the above-described manufacturing method with reference to FIGS. 4(a) and 4(b). Common parts are given common symbols, and explanations of common effects and configurations will be omitted.
The manufacturing method according to the second embodiment differs from the first embodiment in that the distal end surface 110b of the positioning protrusion 110 is formed in an inclined shape. Another difference is that a plurality of positioning protrusions 110 are provided so as to correspond to the top of the cavity 102 partitioned into an arc shape. Therefore, the difference is that a plurality of recesses 70 formed in the porous body 7 are provided corresponding to the number and formation positions of the positioning protrusions 110.

As shown in FIGS. 4(a) and 4(b), the mold 100 in the second embodiment, specifically, the convexly curved top portion 101b of the lower mold cavity 101a (see FIG. 4(b)) includes: A plurality of positioning protrusions 110 into which the recesses 70 of the porous body 7 are inserted are formed to protrude toward the upper die 103. Among the plurality of positioning protrusions 110, 110 formed, the tip surface 110b of the positioning protrusion 110 provided directly below the resin injection part 120 is formed in an inclined shape as described above. The direction of inclination of the tip surface 110b is inclined so that the molten resin 8 is guided to the side where the cavity 102 is wider. On the other hand, among the plurality of positioning protrusions 110, 110, the tip surfaces 110a of the positioning protrusions 110 that are not directly below the resin injection part 120 are formed into substantially horizontal flat surfaces as in the first embodiment.

According to the above, since the tip surface 110b of the positioning protrusion 110 provided directly below the resin injection part 120 is formed in an inclined shape, after the molten resin 8 reaches the tip surface 110b, The direction of the flow of the molten resin 8 changes depending on (see arrows c1 and c2 in FIG. 4(a)). Therefore, the flow direction of the molten resin 8 in the cavity 102 can be adjusted by adjusting the inclination state (the direction of inclination, the inclination angle, etc.) of the tip end surface 110b of the positioning protrusion 110, and the shape of the spacer 5 (molded body 6) can be adjusted. Accordingly, a preferred resin flow can be induced.

Furthermore, according to the above, when manufacturing the spacer 5, when the molten resin 8 is injected from the resin injection part 120 and flows into the cavity 102, it may receive injection pressure in the direction of rotating the porous body 7. Even in such a case, since a plurality of positioning protrusions 110, 110 are provided and a plurality of corresponding recesses 70, 70 are also provided, the porous body 7 will rotate around the positioning protrusion 110. Never. That is, according to the above, positioning can be performed even with respect to the rotation of the porous body 7, which contributes to improving the quality of the spacer 5 in which the porous body 7 and the molded body 6 are integrally molded.

Note that the configuration, shape, etc. of the spacer 5 and the mold 100 are not limited to the above-described embodiments. For example, the position where the porous body 7 is fixed to the molded body 6 constituting the spacer 5 (the position in the depth direction of the cooling water flow path 3, the position in the circumferential direction) and the number of porous bodies 7 (the position in the depth direction of the cooling water flow path 3) The number of spacers in the depth direction and the number of spacers in the circumferential direction are determined by the specifications required, such as the stability of the spacer 5 disposed in the cooling water flow path 3 or the cooling function of the cooling water flowing in the cooling water flow path 3. It may be changed as appropriate. In addition, the shape of the molded body 6 is shown as a partial spacer in the embodiment, but it may be a fully cylindrical shape extending around the entire circumference of the cooling water flow path 3 or a half-cylindrical shape (half-split shape). Good too. Furthermore, the illustrated spacer 5 may be placed at one place in the cooling water flow path 3 or may be placed at multiple places, and the number of partial spacers to be placed depends on the space within the cooling water flow path 3 and the required number of spacers. It may be set as appropriate depending on the specifications and the like. The shape of the recess 70 provided in the porous body 7 is not particularly limited. For example, the recess 70 need not be circular in front view, but may be square or hexagonal. Further, the recess 70 does not need to be a through hole, but may be a hole with a bottom. In this case, the positioning protrusion 110 is provided so as to face the resin injection part 120 with the recess 70 interposed therebetween. In addition, if the tip surface 110b of the positioning projection 110 is formed in an inclined shape, even if the porous body 7 is interposed between the tip surface 110b of the positioning projection 110 and the resin injection part 120, the positioning Depending on the shape of the tip surface 110b of the protrusion 110, the flow of resin can be guided in a desired direction.

The porous body 7 is also not limited to the above embodiment. For example, as the porous body 7, any of fine particles with very small bubbles, small particles with small bubbles, and medium particles with medium bubbles may be used. Specifically, a cellulose sponge having a bubble size (diameter) of about 0.1 to 5 mm may be used. The size of these bubbles is determined by the particle size of the crystalline sulfate used in the process of making the cellulosic sponge. Further, the cellulose sponge is preferably made of cellulose and reinforcing fibers, but is not limited thereto, and may be made of cellulose alone. In addition to sponges made of cellulose itself, cellulose sponges include sponges made of cellulose derivatives that retain cellulose hydroxyl groups to the extent that they can maintain a compressed state, such as cellulose ethers, cellulose esters, etc. The sponge may be selected from any of these mixtures. Further, the porous body 7 is not limited to a cellulose sponge. As the porous body 7, for example, a water-swellable sheet, a porous sheet maintained in a compressed state by a water-soluble binder, or a binder that melts at a temperature equal to or higher than a predetermined temperature may be used. Furthermore, the predetermined external factor that causes the porous body 7 to expand is not limited to the cooling water flowing through the cooling water flow path 3, but may include cooling water that has been heated by the operation of the engine and has reached a predetermined temperature or higher. It's okay.
The structure of the spacer 5 is not limited to the illustrated example, and may include a part of a metal member by insert molding or the like. In addition, the porous body 7 in the illustrated example is explained as an example in which the porous body 7 itself is compressed and held, but a part of the porous body 7 is compressed and held. It may be processed into.

1 Cylinder block 3 Cooling water channel 5 Spacer 6 Molded body 60 Resin introduction part 7 Porous body 70 Recess (through hole)
8 Molten resin 100 Molding mold 102 Cavity 110 Positioning protrusion 110a, 110b Tip surface 120 Resin injection part

Claims (6)

A method for manufacturing a spacer disposed in a cooling water flow path provided in a cylinder block of an internal combustion engine so as to surround a cylinder bore, the spacer comprising:
A processing step of processing the porous body into a porous body that restores to its pre-compression state and expands upon the addition of a predetermined external factor, and forming recesses in the porous body;
a molding step of inserting the recess into a positioning protrusion provided on a mold to position the porous body, and then injecting and molding a molten resin into a cavity of the mold;
A method for manufacturing a spacer, characterized in that the positioning protrusion is provided at a position facing a resin injection part that introduces molten resin into the cavity. In claim 1,
The recess is a through hole penetrating the porous body,
A method for manufacturing a spacer, characterized in that molten resin is injected into the cavity while the positioning protrusion is inserted into the through hole. In claim 1 or claim 2,
The positioning protrusion has a tip end surface formed in an inclined shape,
A method for manufacturing a spacer, comprising injecting molten resin from the resin injection section toward the tip surface. In any one of claims 1 to 3,
The method for manufacturing a spacer, wherein the positioning protrusion is formed such that its tip end surface overlaps the entire opening of the resin injection section. In any one of claims 1 to 4,
The cavity is divided into an arc shape corresponding to the cylinder bore,
A plurality of the positioning protrusions are provided so as to correspond to the top of the cavity,
A method of manufacturing a spacer, wherein a plurality of the recesses are provided in the porous body in correspondence with the positioning protrusions. A spacer disposed in a cooling water flow path provided in a cylinder block of an internal combustion engine so as to surround a cylinder bore, and comprising a molded body made of resin and a porous body integrally fixed to the molded body,
A molded body having a resin introduction part that is an introduction site for molten resin during injection molding and is provided at a position overlapping with the porous body, and a molded body that is provided on the inner or outer surface of the molded body and at least a part thereof. a porous body that can maintain a compressed state and has the property of restoring to its pre-compression state and expanding when a predetermined external factor is added;
The porous body is provided with a recess into which a positioning protrusion for positioning the porous body in a mold is inserted when insert molding the porous body and the molded body,
The spacer is characterized in that the recess and the resin introduction part are arranged so as to overlap in the compression direction of the porous body.

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