JP2017150460A - Engine member, internal combustion engine with the engine member, and process of manufacture of engine member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique effective for improving castability of an engine member configured to guide and support an oil level gauge through a guide pipe.SOLUTION: A cylinder block 20 is provided with a supporting part 30 for guiding and supporting an oil level gauge 14 through an oil level gauge guide 16. The supporting part 30 has a cylindrical boss part 42 and a disk-like enclosing part 52 for enclosing the boss part. A lower end part 42b of the boss part 42 is formed with two recesses 44, 45. The recesses 44, 45 are formed at a circumferential position of the lower end part 42b corresponding to the most-downstream part in a flowing direction of molten metal flowing into a cavity for forming the boss part when the cylinder block 20 is casted and formed. With this arrangement as above, since it is not necessary to charge the molten metal to a portion where the molten metal is hardly charged, a charging efficiency of the molten metal into the cavity for forming the boss part is improved. As a result, it is possible to restrict preferably occurrence of shrinkage cavity at the boss part 42.SELECTED DRAWING: Figure 11

Description

  The present invention relates to an engine member configured to be capable of guiding and supporting an oil level gauge via a guide tube, an internal combustion engine including the engine member, and a method for manufacturing the engine member.

  Japanese Utility Model Publication No. 5-40245 (Patent Document 1) describes a crankcase as an engine member configured to be able to insert and support an oil level gauge for detecting the amount of lubricating oil of an internal combustion engine. . A thick boss portion is provided at the lower portion of the crankcase, and a guide tube is press-fitted and fixed to the boss portion.

  In the crankcase described in the above-mentioned publication, the oil level gauge can be satisfactorily guided into the oil pan by adopting a configuration in which the oil level gauge is guided and supported through the guide tube.

Japanese Utility Model Publication No. 5-40245

  By the way, the engine member such as a crankcase is generally cast and molded. In this case, the mold cavity forming the thick boss is not easily filled with the molten metal, and the nest Holes (cast holes) are likely to occur. Therefore, in the case of the crankcase described above, there is a high demand for improvement in castability by improving the fillability of the molten metal into the mold cavity constituting the boss portion.

  The present invention has been made in view of the above, and an object thereof is to provide a technique effective in improving the castability of an engine member configured to guide and support an oil level gauge through a guide tube. .

  The engine member of the present invention, the internal combustion engine including the engine member, and the method of manufacturing the engine member employ the following means in order to achieve the above-described object.

  According to the preferable form of the engine member according to the present invention, an engine member capable of guiding and supporting the oil level gauge through the guide tube is configured. The engine member includes a substantially cylindrical boss portion having a hole for inserting and supporting the guide tube. The boss portion has a protruding end portion that is configured to protrude toward the inside of the engine member. And the said protrusion edge part is comprised so that it may have a notch.

  Here, the “engine member” in the present invention corresponds to main members constituting the engine, for example, a cylinder head, a cylinder block, a crankcase, a chain cover, a rocker cover, an oil pan, and the like. Further, in the aspect of the present invention “configured to project toward the inside of the engine member”, the projecting end portion of the boss portion is a space configured inside the engine member (for example, a valve mechanism chamber or a crank). This is the case in which it is configured to protrude into the chamber, chain chamber, oil pan, etc.).

  According to the present invention, since the protruding end portion of the boss portion has a notch, in an engine member formed by casting, in the protruding end portion forming cavity for forming the protruding end portion during casting. The amount of molten metal that must be filled in can be reduced. Thereby, the filling efficiency of the molten metal into the projecting end portion forming cavity can be improved, and shrinkage cavities can be prevented from being generated in the boss portion, particularly the projecting end portion. As a result, the quality of the engine member can be improved.

  According to the further form of the engine member which concerns on this invention, the protrusion edge part is comprised so that it may have two or more notches.

  According to this embodiment, the amount of the molten metal that must be filled into the protruding end portion forming cavity can be further reduced, so that the efficiency of filling the molten metal into the protruding end portion forming cavity can be improved. Further, it is possible to further suppress the occurrence of shrinkage cavities at the boss portion, particularly at the protruding end portion. Note that if the notch is formed at a position corresponding to the most downstream portion in the flow direction of the molten metal flowing into the protruding end molding cavity, the filling efficiency of the molten metal into the protruding end molding cavity is effective. In addition, the heat capacity can be reduced, and it is possible to further suppress the formation of shrinkage cavities in the boss portion, particularly the protruding end portion.

  According to the further form of the engine member which concerns on this invention, the protrusion edge part is comprised so that the force which inclines the guide pipe | tube by the dead weight of an oil level gauge can be received. Moreover, the notch is provided in the position which opposes the direction where the said force acts of a protrusion end part. And it is comprised so that a guide tube may contact two corner | angular parts comprised at the protrusion end part by the said notch.

  According to the present embodiment, when a force for tilting the guide tube is applied to the guide tube, the guide tube can be brought into contact with the protruding end portion at two points. Thereby, there is no notch at the position facing the direction in which the force acts, and the stress acting on the projecting end can be reduced compared to the configuration in which the guide tube contacts the projecting end at one point, It becomes possible to reduce the thickness of the boss part. As a result, the filling efficiency of the molten metal into the projecting end portion forming cavity can be further improved, and the occurrence of shrinkage cavities in the boss portion, particularly the projecting end portion, can be further suppressed.

  According to the further form of the engine member according to the present invention, the boss portion is notched with respect to the central axis of the hole on the inner peripheral surface of the hole of the boss portion when the guide tube contacts the two corner portions. The guide tube is configured to be supported at three points by bringing the guide tube into contact with the inner circumferential surface opposite to the side on which the guide is formed.

  Here, as an aspect of “contacting the guide tube to the inner peripheral surface opposite to the side where the notch is formed”, the guide tube is connected to the inner peripheral surface of the hole of the boss portion through a seal member such as an oil ring. In addition to the mode in which the guide tube is brought into contact, a mode in which the guide tube is in direct contact with the inner peripheral surface of the hole of the boss portion is suitably included. According to this embodiment, since the guide tube is supported at three points, stable support of the guide tube can be realized. The position where the guide tube is brought into contact with the inner peripheral surface of the hole of the boss portion is a position away from the notch in the extending direction of the central axis of the hole, that is, the inner peripheral surface of the hole of the boss portion. It is preferable that the position be close to the opening on the side opposite to the notch side. Thereby, it can suppress that the inclination-angle of a guide tube increases.

  According to the further form of the engine member which concerns on this invention, it is further provided with the surrounding part comprised so that the protrusion edge part might be surrounded. And the surrounding part is comprised so that it may have a cross-sectional shape which becomes substantially left-right symmetric across the boss part.

  According to this embodiment, when the engine member is cast-molded, the cavity constituting the surrounding portion functions to guide the melt into the projecting end portion forming cavity, so that the molten metal into the projecting end portion forming cavity The filling efficiency is effectively improved. Moreover, since the surrounding portion has a cross-sectional shape that is substantially symmetrical with respect to the boss portion, the inflow of the molten metal into the projecting end portion forming cavity can be made uniform.

  According to a preferred embodiment of the internal combustion engine according to the present invention, the engine member according to any one of the above-described aspects, a guide tube inserted and supported in the hole of the boss portion of the engine member, and a lower portion of the engine member And an oil level gauge configured to be able to be inserted into the guide tube. Then, by inserting the oil level gauge into the guide pipe, after bringing the oil level gauge into contact with the lubricating oil stored in the oil pan, by removing the oil level gauge in contact with the lubricating oil from the guide pipe, It is configured to be able to detect the amount of lubricating oil.

  According to the present invention, since the oil level gauge is guided and supported using the engine member according to any one of the above-described aspects, the same effect as that produced by the engine member of the present invention, for example, a protrusion It is possible to effectively improve the filling efficiency of the molten metal into the end molding cavity and to suppress the occurrence of shrinkage cavities in the boss portion, particularly the protruding end portion. As a result, the quality of the internal combustion engine can be improved.

  According to the preferable form of the manufacturing method of the engine member which concerns on this invention, the manufacturing method of the engine member which casts and molds an engine member using a casting_mold | template is comprised. The engine member has a substantially cylindrical boss portion for inserting and supporting a guide tube capable of guiding and supporting the oil level gauge. Moreover, the boss | hub part has the protrusion edge part comprised in the shape of protrusion toward the inner side of an engine member. In the manufacturing method of the engine member, a projecting end portion that forms a projecting end portion by pouring molten metal into a substantially annular projecting end portion forming cavity for forming a projecting end portion of a cavity constituted by a mold. A molding process is provided. The protruding end portion forming step includes a notch forming step of forming a notch at a position corresponding to the most downstream portion in the flow direction of the molten metal flowing into the protruding end portion forming cavity of the protruding end portion.

  According to this embodiment, since the notch is formed in the portion of the boss portion corresponding to the most downstream portion in the flow direction of the molten metal among the protruding end forming cavities that is most difficult to be filled with the molten metal, the protruding end forming cavity The filling efficiency of the molten metal into the inside can be effectively improved. In addition, the heat capacity can be reduced, and thereby it is possible to further suppress the formation of shrinkage cavities in the boss portion, particularly the protruding end portion.

  According to the further form of the manufacturing method of the engine member which concerns on this invention, the part used as the most downstream part is provided in the protrusion end part formation cavity. And a notch formation process is a process of shape | molding a notch in each of the position corresponding to two most downstream parts among protrusion edge parts.

  According to this embodiment, in the case where there are two most downstream portions in the molten metal flow direction in which the molten metal is most difficult to be filled in the protruding end molding cavity, the efficiency of filling the molten metal into the protruding end molding cavity is effective. Can be improved. Thereby, it can further suppress that a shrinkage nest arises in a boss | hub part, especially a protrusion end part.

  ADVANTAGE OF THE INVENTION According to this invention, the technique effective in the improvement of the castability of the engine member comprised so that an oil level gauge may be guided and supported via a guide pipe can be provided.

1 is a configuration diagram showing an outline of a configuration of an internal combustion engine 1 according to an embodiment of the present invention. 2 is a perspective view illustrating an outline of a configuration of a cylinder block 20. FIG. 2 is a side view of a cylinder block 20. FIG. FIG. 4 is a bottom view of the cylinder block 20 as viewed from the direction of arrow V in FIG. 3. It is a principal part enlarged view which expands and shows the A section of FIG. It is sectional drawing which shows the BB cross section of FIG. It is sectional drawing which shows CC cross section of FIG. FIG. 5 is an explanatory diagram showing an outline of a support portion forming cavity CAB constituted by a lower die 82 and a slide core 84. It is sectional drawing which looked at the structure of cavity CAB for support part shaping | molding from the direction corresponding to the DD cross section of FIG. It is sectional drawing which looked at the structure of cavity CAB for support part shaping | molding from the direction corresponding to the EE cross section of FIG. FIG. 5 is an explanatory diagram showing a state of contact between the oil level gauge guide 16 and the boss portion 42 when a force for inclining the oil level gauge guide 16 acts on the oil level gauge guide 16. The figure which looked at the mode of contact with oil level gauge guide 16 and boss part 42 when the force which inclines oil level gauge guide 16 acted on oil level gauge guide 16 from the tip side of lower end part 42b of boss part 42 It is.

  Next, the best mode for carrying out the present invention will be described using examples.

  As shown in FIG. 1, the internal combustion engine 1 according to the present embodiment includes a cylinder head 2, a rocker cover 4 attached to the upper part of the cylinder head 2, and a cylinder block 20 attached to the lower part of the cylinder head 2. The upper oil pan 6 attached to the lower part of the cylinder block 20, the lower oil pan 8 attached to the lower part of the upper oil pan 6, the intake manifold 10 attached to the cylinder head 2, the cylinder head 2 and the rocker cover 4. A front cover 12 fastened to the cylinder block 20 and the upper oil pan 6 and an oil level gauge 14 supported by the cylinder block 20 via an oil level gauge guide 16 are provided. In the present embodiment, for convenience, the rocker cover 4 side, that is, the upper side of the paper surface in FIG. 1 is defined as “upper” or “upper”, and the lower oil pan 8 side, that is, the lower side of the paper surface in FIG. It is defined as “lower” or “lower”.

  The cylinder block 20 is one of the members constituting the skeleton of the internal combustion engine 1. As shown in FIG. 2, the cylinder block 22, a skirt portion 24 formed integrally with the lower portion of the cylinder portion 22, and a skirt And a flange portion 26 formed integrally with the portion 24. The cylinder block 20 according to the present embodiment is formed by pressure die casting using an aluminum alloy. The cylinder block 20 is an example of an implementation configuration corresponding to the “engine member” in the present invention.

  As shown in FIG. 2, the cylinder part 22 includes four cylinder bores 22a and a water jacket 22b configured to surround the four cylinder bores 22a.

  The skirt portion 24 is a portion constituting the crank chamber CR below the cylinder bore 22a. As shown in FIG. 4, the skirt portion 24 includes partition wall portions 24a, 24b, and 24c that partition the crank chamber CR for each cylinder bore 22a. The partition wall portions 24a, 24b, and 24c have bearing portions (not shown) for rotatably supporting a crankshaft (not shown).

  As shown in FIG. 2, the flange portion 26 is configured to protrude from the skirt portion 24, and the upper oil pan 6 is fastened to the flange portion 26.

  Further, as shown in FIGS. 2 and 3, a support portion 30 for supporting the oil level gauge guide 16 is provided at the connection portion between the skirt portion 24 and the flange portion 26. More specifically, as shown in FIG. 4, the support portion 30 is provided at a position adjacent to the partition wall portion 24 a. As shown in FIG. 7, the boss portion 42 and most of the boss portion 42 are provided. And an enclosure portion 52 configured to surround the enclosure. Thus, the strength of the support part 30 is improved by providing the support part 30 at a position adjacent to the partition wall part 24a.

  As shown in FIGS. 5 to 7, the boss portion 42 is formed in a substantially cylindrical shape having a through hole 42a therein. As shown in FIG. 11, an oil level gauge guide 16, which will be described later, is inserted into and supported by the through hole 42a via an oil ring OR. Further, as shown in FIGS. 6 and 7, the boss portion 42 is configured such that the lower end portion 42 b protrudes inside the cylinder block 20, more specifically, into a space S formed by the surrounding portion 52. Yes. The through hole 42a corresponds to the “hole” in the present invention, and the lower end portion 42b is an example of an implementation configuration corresponding to the “projecting end portion” in the present invention.

  As shown in FIGS. 5 and 6, the lower end portion 42 b of the boss portion 42 has notches 44 and 45. It can be said that the lower end portion 42b is divided into two in the circumferential direction by both notches 44 and 45. As shown in FIG. 5, the notches 44 and 45 are arranged in series along the extending direction of the partition wall portion 24a (the vertical direction in FIG. 5) on the circumference of the lower end portion 42b. The extending direction of both notches 44 and 45 is also along the direction in which the oil level gauge guide 16 is inclined when a force for inclining the oil level gauge guide 16 described later is applied.

  As shown in FIG. 7, the surrounding portion 52 has a substantially circular lid shape that bulges from the flange portion 26. The upper end of the surrounding portion 52 is connected to the upper portion of the boss portion 42, whereby the lower end portion 42 b of the boss portion 42 is surrounded by the surrounding portion 52. As shown in FIG. 7, the surrounding portion 52 is formed to be symmetrical with respect to the boss portion 42.

  Here, a method for forming the support portion 30 will be described. The support part 30 is shape | molded using the casting_mold | template 80, as shown in FIG. 8 and FIG. A mold 80 for forming the support portion 30 is mainly composed of a lower mold 82 and a slide core 84. The lower mold 82 is provided with a cylindrical core portion 86 for forming the through hole 42 a of the boss portion 42. As shown in FIGS. 8 to 10, a substantially annular groove 83 is formed around the cylindrical core portion 86.

  In addition, the groove | channel 83 is interrupted | disconnected in two places of the circumferential direction, as shown in FIG.8 and FIG.10. That is, it is divided into two parts by two ribs 86a integrally formed so as to protrude radially outward from the outer peripheral surface of the cylindrical core part 86. Although not shown, the two ribs 86a are provided in a straight line along the extending direction of the cavity constituting the partition wall portion 24a (the direction perpendicular to the arrangement direction of the cylinder bores 22a, the vertical direction in FIG. 10). It has been.

  Moreover, as shown in FIG. 9, the lower mold 82 is provided with a gate 90 for supplying molten metal. As shown in FIG. 4, four gates 90 are arranged on both sides of the cylinder bore 22a. More specifically, four gates 90 are arranged in the arrangement direction of the cylinder bores 22a in such a positional relationship as to sandwich the partition walls 24a, 24b, and 24c.

  By clamping the mold 80 thus configured, as shown in FIGS. 8 to 10, a support part forming cavity CAB for forming the support part 30 is formed. As shown in FIG. 9, the support portion forming cavity CAB includes a boss portion forming cavity CAB1 for forming the boss portion 42 and a surrounding portion forming cavity CAB2 for forming the surrounding portion 52. ing.

  The boss portion forming cavity CAB1 is configured as a substantially cylindrical space, and the surrounding portion forming cavity CAB2 is configured as a substantially cap-shaped space. As shown in FIG. 9, the upper end portion of the surrounding portion forming cavity CAB2 is connected to the upper portion of the boss portion forming cavity CAB1. The boss part forming cavity CAB1 is an example of an implementation configuration corresponding to the “projecting end part forming cavity” in the present invention.

  After the mold is clamped, the molten aluminum alloy is supplied into the support portion forming cavity CAB at a high pressure. As shown in FIG. 9, the molten metal supplied from the gate 90 into the support portion molding cavity CAB first flows into the surrounding portion molding cavity CAB2. At this time, since the surrounding part forming cavity CAB2 has a circular lid shape, the molten metal smoothly flows into the surrounding part forming cavity CAB2. Then, it flows into the boss portion forming cavity CAB1 from the surrounding portion forming cavity CAB2.

The molten metal that has flowed into the boss portion forming cavity CAB1 flows along the circumferential direction toward both ribs 86a, as indicated by arrows in FIG. Here, in the most downstream portion in the flow direction of the molten metal flowing through the boss portion forming cavity CAB1, the molten metal flow rate is reduced, so that the molten metal is difficult to be filled and causes shrinkage. In the present embodiment, Both ribs 86a are provided at a position corresponding to the most downstream portion of the metal, and it is not necessary to fill the molten metal in a portion that is difficult to be filled with the molten metal,
The molten metal can be sufficiently filled in the boss part forming cavity CAB1. Thereby, it is possible to satisfactorily prevent the shrinkage nest from occurring in the boss portion 42. The notches 44 and 45 are formed in the boss portion 42 by both ribs 86a.

  Further, as shown in FIG. 9, since the molten metal from the surrounding part molding cavity CAB2 flows from the upper part of the boss part forming cavity CAB1, the molten metal flow rate is lowered below the boss part forming cavity CAB1. The heading flow is promoted. This also improves the efficiency of filling the molten metal into the boss part forming cavity CAB1. As a result, it is possible to further suppress the occurrence of shrinkage nests in the boss portion 42.

  Next, how the oil level gauge 14 is supported by the support portion 30 thus formed will be described. As shown in FIG. 11, the oil level gauge 14 is guided and supported by the support portion 30 via the oil level gauge guide 16. The oil level gauge guide 16 is made of a pipe material, and is inserted and supported in the through hole 42a of the boss portion 42 via an oil ring OR. The oil level gauge guide 16 is an example of the implementation structure corresponding to the "guide pipe" in this invention.

  Here, a force is applied to the oil level gauge guide 16 to incline the oil level gauge guide 16 in the direction of the arrow in FIG. 11 due to the weight of the oil level gauge 14 and the oil level gauge guide 16. At this time, the oil level gauge guide 16 contacts the inner peripheral surface of the through hole 42a of the boss portion 42 at three points. More specifically, as shown in FIG. 11, the oil level gauge guide 16 is in contact with the inner peripheral surface of the through-hole 42a at one point through the oil ring OR in the upper portion of the through-hole 42a. As shown in FIG. 12, the two corners 45 a formed by the notches 45 in the front end portion of the lower end portion 42 b of the boss portion 42 come into contact with each other at two points.

  As described above, when a force that inclines the oil level gauge guide 16 is applied to the oil level gauge guide 16, the force is applied to the lower end portion 42 b of the boss portion 42 at two points. The stress acting on the lower end portion 42b can be reduced as compared with a configuration in which the notch 45 is not provided at a position facing the direction in which the oil level gauge guide 16 contacts the lower end portion 42b at one point. As a result, the thickness of the boss portion 42 can be reduced, and the filling efficiency of the molten metal into the boss portion forming cavity CAB1 can be further improved. Can be prevented from occurring.

  Since the lower end portion 42b of the boss portion 42 has the notch 45, the position where the oil level gauge guide 16 comes into contact with the lower end portion 42b changes when the above-described force is applied. Although it is conceivable that the inclination angle becomes larger than when the notch 45 is not provided, the inconvenience can be avoided by increasing the length of the boss portion 42 in the protruding direction.

  Here, the length of the boss portion 42 in the protruding direction is the same as the inclination angle of the oil level gauge guide 16 when the oil level gauge guide 16 is not provided with the notch 45 when the above-described force is applied. Can be set to such a value.

  In the present embodiment, when a force for inclining the oil level gauge guide 16 is applied, the circumferential direction of the lower end portion 42b of the boss portion 42 is set at two locations along the direction in which the oil level gauge guide 16 is inclined. The notches 44 and 45 are provided. However, the notches 44 and 45 may be provided along a direction unrelated to the direction in which the oil level gauge guide 16 is inclined. Only one of them may be provided along the direction in which the oil level gauge guide 16 is inclined.

  In the present embodiment, the notches 44 and 45 are provided at two locations in the circumferential direction of the lower end portion 42b of the boss portion 42. However, the present invention is not limited to this. The notch may be provided only at one place in the circumferential direction of the lower end portion 42b, or may be provided at three or more places in the circumferential direction of the lower end portion 42b.

  In this embodiment, the surrounding portion 52 is formed in a circular lid shape, but any shape can be used as long as it can induce the hot water flow to the boss portion 42 (the boss portion forming cavity CAB1) when casting. There may be.

  In the present embodiment, the surrounding portion 52 is configured to be symmetric with respect to the boss portion 42, but the present invention is not limited thereto. For example, the surrounding portion 52 may be configured asymmetrically across the boss portion 42.

  In the present embodiment, the surrounding portion 52 is provided, but the surrounding portion 52 may not be provided.

  This embodiment shows an example for carrying out the present invention. Therefore, the present invention is not limited to the configuration of the present embodiment. The correspondence between each component of the present embodiment and each component of the present invention is shown below.

1 Internal combustion engine (internal combustion engine)
2 Cylinder head 4 Rocker cover 6 Upper oil pan (oil pan)
8 Lower oil pan (oil pan)
10 Intake manifold 12 Front cover 14 Oil level gauge (oil level gauge)
16 Oil level gauge guide (guide pipe)
20 Cylinder block (engine member)
22 Cylinder part 22a Cylinder bore 22b Water jacket 24 Skirt part 24a Partition wall 24b Partition wall 24c Partition wall 26 Flange part 30 Support part 42 Boss part (boss part)
42a Through hole (hole)
42b Lower end (projecting end)
44 Notch (Notch)
45 Notch (Notch)
45a Corner 52 Go part (Go part)
80 Mold (mold)
82 Lower mold 83 Groove 84 Slide core 86 Cylindrical core portion 86a Rib 90 Spout CR Crank chamber OR Oil ring S Space (inside of engine member)
CAB Support part forming cavity CAB1 Boss part forming cavity (projecting end part forming cavity)
CAB2 Go molding cavity

Claims (8)

An engine member configured to be capable of guiding and supporting an oil level gauge through a guide tube,
A substantially cylindrical boss having a hole for inserting and supporting the guide tube;
The boss portion has a protruding end portion configured to protrude toward the inside of the engine member,
The engine member is configured such that the protruding end portion has a notch. The engine member according to claim 1, wherein the protruding end portion is configured to have a plurality of the notches. The projecting end portion is configured to receive a force for inclining the guide tube due to its own weight of the oil level gauge,
The notch is provided at a position facing the direction in which the force acts on the protruding end,
The engine member according to claim 1 or 2, wherein the guide tube is configured to come into contact with two corner portions formed at the protruding end portion by the notch. The boss portion is opposite to the side where the notch is formed with respect to the central axis of the hole on the inner peripheral surface of the hole of the boss portion when the guide tube contacts the two corner portions. The engine member according to claim 3, wherein the guide tube is supported at three points by bringing the guide tube into contact with an inner peripheral surface of the engine member. Further comprising an enclosure configured to enclose the protruding end;
The engine member according to any one of claims 1 to 4, wherein the surrounding portion is configured to have a cross-sectional shape that is substantially symmetrical with respect to the boss portion. The engine member according to any one of claims 1 to 5,
A guide tube inserted and supported in the hole of the boss portion of the engine member;
An oil pan fastened to the lower part of the engine member;
An oil level gauge configured to be insertable into the guide tube;
With
By inserting the oil level gauge into the guide tube, the oil level gauge is brought into contact with the lubricating oil stored in the oil pan, and then the oil level gauge in contact with the lubricating oil is removed from the guide tube. An internal combustion engine configured to be able to detect the amount of the lubricating oil by removing the lubricating oil. An engine member manufacturing method for casting an engine member using a mold,
The engine member has a substantially cylindrical boss portion for inserting and supporting a guide tube capable of guiding and supporting the oil level gauge,
The boss portion has a protruding end portion configured to protrude toward the inside of the engine member,
A projecting end molding step of molding the projecting end by pouring molten metal into a substantially annular projecting end molding cavity for molding the projecting end of the cavity constituted by the mold,
The protruding end portion forming step includes a notch forming step of forming a notch at a position corresponding to the most downstream portion in the flow direction of the molten metal flowing into the protruding end portion forming cavity of the protruding end portion. A method for manufacturing an engine member. The protruding end portion forming cavity is provided with two portions that become the most downstream portion,
The method for manufacturing an engine member according to claim 7, wherein the notch forming step is a step of forming the notch at each of positions corresponding to the two most downstream portions of the protruding end portions.

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