JP6628599B2 - Cover member and internal combustion engine having the same - Google Patents

Description

  The present invention relates to a cover member formed by casting and fastened to an internal combustion engine main body so as to cover a transmission member that transmits rotation of a crankshaft to a camshaft, and an internal combustion engine including the same.

  Japanese Utility Model Laid-Open Publication No. 50-119801 (Patent Document 1) discloses a cover member in which an indicator pin for adjusting ignition timing, valve timing, and the like in an internal combustion engine is integrally formed so as to project from a cover body. Has been described.

  In the cover member described in the above-mentioned publication, two indicator pins are provided in a projecting manner with respect to the cover main body, and the two indicator pins and the center of the crankshaft are arranged in a straight line. It is possible to accurately recognize the rotation angle of the crankshaft without reading errors due to the angle of the line of sight looking at the pin. This makes it possible to more accurately adjust the ignition timing, valve timing, and the like in the internal combustion engine.

Japanese Utility Model Publication No. 50-119801

  By the way, in the cover member as described above, it is general that casting is performed in consideration of manufacturability. However, in the cover member described in the above-mentioned publication, the indicator pin projects in a pin shape with respect to the cover body. Therefore, it is difficult for the molten metal to fill the mold cavity for molding the indicator pin in the mold for molding the cover member, and there is still room for improvement in castability. In addition, since the indicator pin is configured in a pin shape, there is room for improvement in strength.

  The present invention has been made in view of the above, and an object of the present invention is to provide a cover member having an indicator pin, which is capable of achieving both improvement in castability and improvement in strength of the indicator pin.

  The internal combustion engine of the present invention employs the following means to achieve the above object.

According to a preferred embodiment of the cover member according to the present invention, the cover member is formed by casting and fastened to the internal combustion engine main body so as to cover the transmission member that transmits the rotation of the crankshaft to the camshaft. The cover member includes a cover body, an indicator pin, a rib, and a second rib . The indicator pin is provided so as to protrude from the cover main body. The rib and the second rib are configured to connect the cover body and the indicator pin to reinforce the indicator pin. Further , the rib is arranged at a position corresponding to at least the front side in the molten metal flow direction when casting the cover member with the indicator pin interposed therebetween, and is configured so as to be along the molten metal flow direction, from the cover body to the indicator pin. It is configured in a shape having an upward slope. The second rib is arranged at a position corresponding to a rear side of the hot water flowing direction with respect to the indicator pin along the hot water flowing direction, and is configured along the hot water flowing direction. It is configured in a shape having a downward slope toward the part.

  Here, the “internal combustion engine body” in the present invention is defined as a main part constituting the internal combustion engine, and corresponds to, for example, a cylinder head, a rocker cover, a cylinder block, an upper oil pan, and the like. In addition, the “transmission member” in the present invention typically corresponds to a timing chain that connects a crankshaft and a camshaft, but a timing belt that connects a crankshaft and a camshaft, and a crankshaft It preferably includes a gear mechanism for connecting to the camshaft.

  In addition, the “melt flow direction” in the present invention preferably includes not only the main flow direction of the molten metal that has flowed into the mold cavity from the gate, but also the branch direction that flows from the main flow toward each mold cavity. In the present invention, "along the flow direction of molten metal" literally means not only a mode in which the ribs are along the main flow direction or tributary direction of the molten metal, but also a mode in which the ribs are generally along the main flow direction or tributary direction of the molten metal. Included.

According to the present invention, of the mold for casting and molding the cover member, the rib molding mold cavity for molding the rib is at least in the direction of hot water flow with the pin molding mold cavity for molding the indicator pin interposed therebetween. It is arranged at a position corresponding to the front side and is configured so as to be along the flow direction of the molten metal. That is, since the rib-forming mold cavity functions as a guide for guiding the molten metal to the pin-forming mold cavity, the molten metal easily flows into the pin-forming mold cavity. As a result, the molten metal can be satisfactorily filled up to the portion constituting the tip portion of the indicator pin in the mold cavity for pin molding. As a result, castability can be improved. Moreover, the strength of the indicator pin can be improved by the rib. Also, since the rib molding mold cavity is configured so that its depth becomes deeper as it goes toward the pin molding mold cavity, the molten metal reaches the portion of the pin molding mold cavity that constitutes the tip of the indicator pin. Metal can be poured smoothly. Further, the mold cavity for molding the second rib of the mold for molding the cover member is provided at least on the rear side of the mold cavity for molding the pin for molding the indicator pin. In addition to being arranged at a position corresponding to the direction of the molten metal flow, the molten metal that has flowed into the portion that constitutes the tip of the indicator pin in the mold cavity for pin molding is covered with the cover body. It can be smoothly returned to the mold cavity for main body molding for molding. That is, the rib-forming mold cavity for molding the second rib functions as a guide for guiding the molten metal from the pin-forming mold cavity to the body-forming mold cavity. Thereby, since the flow of the molten metal is improved, castability can be further improved. Further, since the rib molding mold cavity for molding the second rib is configured so that its depth becomes shallower toward the main body molding mold cavity, the indicator pin of the pin molding mold cavity is formed. The molten metal that has flowed into the portion constituting the tip portion can be smoothly returned to the cavity for molding the main body.

  According to a further aspect of the cover member according to the present invention, a plurality of ribs are provided.

  According to the present embodiment, the molten metal can be more appropriately poured into the portion constituting the tip end portion of the indicator pin in the pin molding mold cavity.

  According to a further aspect of the cover member according to the present invention, a plurality of second ribs are provided.

  According to the present embodiment, it is possible to improve the return of the molten metal that has flowed into the portion forming the tip portion of the indicator pin in the mold cavity for pin molding to the mold cavity for main body molding.

  According to a preferred embodiment of the internal combustion engine according to the present invention, a cylinder head, a cam shaft rotatably supported by the cylinder head, a cylinder block to which the cylinder head is fastened, and rotatably supported by the cylinder block A timing chain wound around the camshaft and the crankshaft and configured to transmit the rotation of the crankshaft to the camshaft, and fastened to the cylinder head and the cylinder block so as to cover the timing chain. And a crank pulley attached to a tip end of the crankshaft protruding from the cover member of the crankshaft. In the internal combustion engine, the indicator pin is arranged near the crank pulley, a timing mark is provided on the crank pulley, and at least one of the ignition timing and the valve timing can be adjusted by the indicator pin and the timing mark. Have been.

  According to the present invention, since the cover member according to any one of the above-described aspects is provided with the cover member according to the present invention, effects similar to the effects of the cover member of the present invention, for example, improvement in castability and strength of the indicator pin are provided. It is possible to obtain an effect that can achieve both improvement and improvement.

  ADVANTAGE OF THE INVENTION According to this invention, in the cover member which has an indicator pin, the technique which can aim at the improvement of the castability and the improvement of the intensity | strength of an indicator pin can be provided.

FIG. 1 is a schematic configuration diagram illustrating an outline of a configuration of an internal combustion engine 1 according to an embodiment of the present invention. FIG. 2 is a perspective view showing a state where the rocker cover 4, the chain cover 16, the intake manifold 6, and the exhaust manifold 8 have been removed from the internal combustion engine 1 according to the embodiment of the present invention. It is a front view of the chain cover 16. It is a perspective view which expands and shows the indicator pin 52 vicinity part in the chain cover. FIG. 4 is an enlarged view showing part A of FIG. 3 in an enlarged manner. FIG. 6 is a view as viewed from the direction of arrow B in FIG. 5. FIG. 4 is a cross-sectional view showing a CC cross section of FIG. 3.

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

  As shown in FIG. 1, an internal combustion engine 1 according to an embodiment of the present invention includes a cylinder head 2 according to the embodiment, a rocker cover 4 attached to an upper portion of the cylinder head 2, and a cylinder head 2. Intake manifold 6 and exhaust manifold 8 attached, cylinder block 10 attached to the lower part of cylinder head 2, upper oil pan 12 attached to the lower part of cylinder block 10, and attached to the lower part of upper oil pan 12. A lower oil pan 14 and a chain cover 16 according to the embodiment of the present invention.

  The cylinder head 2 is one of the main components of the internal combustion engine 1, and is configured to rotatably support the intake and exhaust camshafts 2a and 2b as shown in FIG. One end of the intake and exhaust camshafts 2a, 2b in the axial direction protrudes from the cylinder head 2, and the cam sprockets 3a, 3b are attached to the one end in the axial direction.

  Like the cylinder head 2, the cylinder block 10 is a main component of the internal combustion engine 1, and is configured to rotatably support a crankshaft 18, as shown in FIG. One end of the crankshaft 18 in the axial direction protrudes from the cylinder block 10, and a crank sprocket 19 is attached to one end of the crankshaft 18 in the axial direction. Further, one end in the axial direction of the crankshaft 18 penetrates through the crank sprocket 19 and the chain cover 16, and as shown in FIG.

  As shown in FIG. 2, a timing chain 22 is wound around the crank sprocket 19 and the cam sprockets 3a and 3b, and the rotation of the crankshaft 18 is transmitted to the intake camshaft 2a and the exhaust camshaft 2b. Thus, the intake valve and the exhaust valve (not shown) are driven to open and close as the crankshaft 18 rotates. The timing chain 22 is an example of an embodiment corresponding to the “transmission member” in the present invention.

  An oil pump (not shown) is attached to the upper oil pan 12, and a rotation shaft 21 of an oil pump (not shown) protrudes from the upper oil pan 12, as shown in FIG. An oil pump sprocket 23 is attached to a protruding end of the rotating shaft 21.

  As shown in FIG. 2, an oil pump chain 24 is wound around the crankshaft 18 and the oil pump sprocket 23, and rotation of the crankshaft 18 is transmitted to a rotating shaft 21 of an oil pump (not shown). Is done. Thus, an oil pump (not shown) is driven with the rotation of the crankshaft 18.

  The chain cover 16 is configured as a cover member that covers the timing chain 22 and the oil pump chain 24, and is formed by, for example, casting using an aluminum alloy. The chain cover 16 is fastened to the cylinder head 2, the rocker cover 4, the cylinder block 10 and the upper oil pan 12 by bolts (not shown). The cylinder head 2, the rocker cover 4, the cylinder block 10, and the upper oil pan 12 are an example of an embodiment corresponding to the "internal combustion engine body" in the present invention.

  As shown in FIG. 3, the casting of the chain cover 16 is performed by using a sprue 90 provided with a molten aluminum alloy (hereinafter, referred to as “molten metal”) provided in a mold (not shown). Is performed by pouring into the hollow portion of In the present embodiment, the gate 90 is disposed on the left side (the left side in FIG. 3) when the chain cover 16 is viewed from the front side in the axial direction of the crankshaft 18. The chain cover 16 is an example of an embodiment corresponding to a “cover member” in the present invention.

  As shown in FIG. 3, the chain cover 16 includes a base portion 32 and an engine mount bracket portion 34. The base portion 32 and the engine mount bracket portion 34 include a cylinder head 2 and a cylinder block 2, respectively. A bolt hole 16 a through which a bolt (not shown) for fastening to the upper oil pan 12 and the upper oil pan 12 is inserted is formed. Although not shown, a bolt hole for fastening to the rocker cover 4 is also formed in the engine mount bracket portion 34.

  As shown in FIG. 3, a through hole 32a for inserting the crankshaft 18 is formed in the lower portion of the base portion 32 in the longitudinal direction (vertical direction in FIG. 3), and an indicator pin portion 50 is provided. Have been. The base portion 32 is formed by pouring molten metal into a cavity of a mold for casting and molding the base portion 32 (hereinafter, referred to as a “base portion molding cavity”). The base 32 is an example of an embodiment corresponding to the “cover body” in the present invention.

  The indicator pin portion 50 is configured as an indicator for reading a timing mark provided on the crank pulley 20 to know the top dead center and the ignition timing of the piston (not shown) or the opening / closing timing of the intake / exhaust valve (not shown). As shown in the figure, the outer peripheral portion of the through hole 32a of the base portion 32 is provided at an obliquely upper right portion of the through hole 32a.

 As shown in FIGS. 4 and 5, the indicator pin portion 50 includes an indicator pin 52 and three ribs 54, 56, 58. The indicator pin 52 is formed in an elongated cylindrical shape, and stands upright on the base 32 so as to protrude from the base 32. As shown in FIG. 7, the projecting height of the indicator pin 52 is adjusted so that the timing mark provided on the crank pulley 20 can be read. Is set to be substantially the same as the position of the axial end face 20a.

  Here, the cavity of the mold for casting the indicator pin 52 (hereinafter, referred to as “pin molding mold cavity”) is formed in an elongated bottomed hole corresponding to the shape of the indicator pin 52.

  As shown in FIG. 5, the ribs 54, 56, 58 have a substantially collapsed Y-shape when viewed from above (when viewed in the direction of the paper surface of FIG. 5). As shown in FIGS. 3 and 5, the rib 54 is disposed on the front side in the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5) with the indicator pin 52 interposed therebetween. , And extend in a direction substantially along the outer peripheral surface of the crank pulley 20.

  As shown in FIGS. 4 and 6, the rib 54 is configured to connect the base 32 and the tip of the indicator pin 52, and is inclined upward toward the tip of the indicator pin 52. It is formed in a substantially triangular shape in a side view having an inclined surface (in other words, an inclined surface which is inclined downward from the tip end portion of the indicator pin 52 toward the base portion 32).

  Here, the cavity of the mold for casting and molding the rib 54 (hereinafter referred to as “mold cavity for molding the rib 54”) is formed in a triangular recess corresponding to the shape of the rib 54. That is, it is configured to have an inclined bottom whose depth gradually increases toward the bottom of the cavity of the pin molding mold. It is noted that the rib 54 molding mold cavity is configured to extend in a direction substantially along the flow direction of the molten metal from the gate 90 and in a direction substantially along the outer peripheral surface of the crank pulley 20. Needless to say.

  As described above, since the mold cavity for forming the rib 54 is formed substantially along the flow direction of the molten metal from the sprue 90, the molten metal flowing into the mold cavity for forming the base from the sprue 90 is removed by the rib. 54 easily flows into the mold cavity. Thereby, the inflow of the molten metal into the mold cavity for pin molding through the mold cavity for rib 54 can be promoted.

  In addition, since the depth of the mold cavity for forming the rib 54 gradually increases toward the bottom of the mold cavity for pin molding, the pin mold formed in the elongated bottomed hole through which the molten metal does not easily flow. The molten metal can be satisfactorily poured to the bottom of the mold cavity. Thereby, the castability of the indicator pin 52 can be improved.

  Further, the strength of the indicator pin 52 can be improved by the ribs 54 thus molded.

  As shown in FIGS. 3 and 5, the rib 56 is disposed on the rear side of the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5) with the indicator pin 52 interposed therebetween. It is configured to extend in a direction substantially along the direction and in a direction substantially along the outer peripheral surface of the crank pulley 20.

  4 and 6, similarly to the rib 54, the rib 56 is configured to connect the base 32 and the tip of the indicator pin 52. It is configured in a substantially triangular shape in a side view having an inclined surface that is inclined downward toward the portion 32 (in other words, an inclined surface that is inclined upward from the base portion 32 toward the tip end portion of the indicator pin 52). The rib 56 is an example of an embodiment corresponding to the “second rib” in the present invention.

  Here, the cavity of the mold for casting and molding the rib 56 (hereinafter, referred to as “mold cavity for molding the rib 56”) has basically the same configuration as the cavity of the mold for molding the rib 54. That is, the inclined bottom is formed in a triangular recess corresponding to the shape of the rib 56, and the depth gradually decreases from the bottom of the pin-forming mold cavity toward the base-forming mold cavity. (Inclined bottom) whose depth gradually increases toward the mold cavity. Further, the rib 56 molding cavity may be configured so as to extend in a direction substantially along the flow direction of the molten metal from the gate 90 and in a direction substantially along the outer peripheral surface of the crank pulley 20. The same as the mold cavity for molding the rib 54.

  In this way, the rib 56 molding mold cavity is formed so as to substantially follow the flow direction of the molten metal from the gate 90, so that the molten metal flowing into the pin molding mold cavity can be filled with the rib 56 molding mold cavity. It can be smoothly returned from the portion to the mold cavity for molding the base portion. Thereby, the castability of the indicator pin 52 can be further improved. The strength of the indicator pin 52 together with the rib 54 can be improved by the rib 56 thus configured.

  As shown in FIGS. 3 and 5, the rib 58 is disposed behind the indicator pin 52 in the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5). It is configured to extend in a direction substantially along the direction and in a direction away from the outer peripheral surface of the crank pulley 20. .

  As shown in FIG. 7, the rib 58 is configured to connect the base 32 and the tip of the indicator pin 52, similarly to the ribs 54 and 56. It is configured in a substantially triangular shape in a side view having an inclined surface which is inclined downward toward the direction 32 (in other words, an inclined surface which is inclined upward from the base portion 32 toward the distal end portion of the indicator pin 52). The rib 58 is an example of an embodiment corresponding to the “second rib” in the present invention.

  Here, the cavity of the mold for casting and molding the rib 58 (hereinafter, referred to as “mold cavity of the rib 58”) is basically the same as the mold cavity of the rib 54 and the mold of the rib 56. Configuration. That is, the inclined bottom is formed in a triangular recess corresponding to the shape of the rib 58, and the depth gradually decreases from the bottom of the pin-forming mold cavity toward the base-forming mold cavity (in other words, the pin-forming mold). (Inclined bottom) whose depth gradually increases toward the mold cavity. Note that the rib 58 molding mold cavity is configured to extend in a direction substantially along the flow direction of the molten metal from the sprue 90 and away from the outer peripheral surface of the crank pulley 20. Needless to say.

  By forming the mold cavity for forming the rib 58 so as to substantially follow the flow direction of the molten metal from the gate 90 in this manner, the same effect as that provided by the cavity for forming the rib 56, that is, the pin The molten metal that has flowed into the mold cavity for molding can be smoothly returned from the mold cavity for forming the rib 58 to the mold cavity for forming the base. Thereby, the castability of the indicator pin 52 can be further improved. The strength of the indicator pin 52 together with the ribs 54 and 56 can be improved by the rib 58 thus configured.

  According to the chain cover 16 according to the embodiment of the present invention described above, the ribs 54, 56, 58 connecting the indicator pin 52 and the base portion 32 of the chain cover 16 are connected to the flow direction of the molten metal from the gate 90. Since the ribs 54, 56 and 58 are merely formed in a substantially triangular shape in a side view having an inclined surface that is inclined upward toward the tip of the indicator pin 52, a simple configuration is provided. However, it is possible to achieve both improvement in the castability of the chain cover 16, particularly, the indicator pin 52, and improvement in the strength of the indicator pin 52.

  Further, according to the chain cover 16 according to the embodiment of the present invention, one rib 54 is arranged on the front side in the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5) with the indicator pin 52 interposed therebetween. Since the two ribs 56 and 58 are arranged on the rear side of the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5) with the indicator pin 52 interposed therebetween, when the chain cover 16 is cast-molded. Since the molten metal that has flowed into the mold cavity for pin molding can be favorably returned to the mold cavity for base molding without staying in the mold cavity for pin molding, the castability of the indicator pin 52 can be further improved. Can be improved. The strength of the indicator pin 52 can be improved by the ribs 54, 56, 58.

  In the present embodiment, the ribs 54, 56, 58 are formed in a substantially triangular shape when viewed from the side. However, the present invention is not limited to this, as long as the shape smoothly connects the base 32 and the tip of the indicator pin 52. For example, the ribs 54, 56, 58 may be formed in a substantially square shape in a side view, or may be formed in a substantially fan shape in a side view.

  In the present embodiment, the two ribs 56 and 58 are provided on the rear side of the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5) with the indicator pin 52 interposed therebetween, but the present invention is not limited to this. For example, a structure without ribs, a structure with only one rib, or a structure with three ribs is provided on the rear side of the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5) with the indicator pin 52 interposed therebetween. More than one may be provided.

  In the present embodiment, only one rib 54 is provided on the front side in the flow direction of the molten metal (in the direction of the dashed arrow in FIGS. 3 and 5) with the indicator pin 52 therebetween. In this case, a plurality of ribs may be provided on the front side in the flow direction of the molten metal (the direction of the dashed arrow in FIGS. 3 and 5).

  In the present embodiment, the chain cover 16 is configured to have the engine mount bracket 34, but may be configured to not have the engine mount bracket 34.

  The present embodiment shows an example of a mode for carrying out the present invention. Therefore, the present invention is not limited to the configuration of the present embodiment.

1 internal combustion engine (internal combustion engine)
2 Cylinder head (internal combustion engine body, cylinder head)
2a Intake camshaft (intake camshaft)
2b Exhaust camshaft (Exhaust camshaft)
3a cam sprocket 3b cam sprocket 4 rocker cover (internal combustion engine body)
6 Intake manifold 8 Exhaust manifold 10 Cylinder block (internal combustion engine body, cylinder block)
12 Upper oil pan (internal combustion engine body)
14 Lower oil pan 16 Chain cover (cover member)
16a bolt hole 18 crankshaft (crankshaft)
19 Crank sprocket 20 Crank pulley (Crank pulley)
20a Axial end face 22 Timing chain (transmission member, timing chain)
23 oil pump sprocket 24 oil pump chain 32 base (cover body)
32a Through hole 34 Engine mount bracket 50 Indicator pin 52 Indicator pin (indicator pin)
54 ribs
56 ribs (second rib)
58 rib (second rib)
90 gate

Claims (4)

A cover member molded by casting and fastened to the internal combustion engine body to cover a transmission member that transmits rotation of the crankshaft to the camshaft,
A cover body,
An indicator pin protruding from the cover body,
A rib and a second rib configured to connect the cover body and the indicator pin to reinforce the indicator pin ;
With
Said ribs, said disposed at least in a position corresponding to the front side of the hot water flow direction when casting the cover member relative to the indicator pin Rutotomoni, is configured along the melt flow direction, said from the cover main body It is configured in a shape having an upward slope toward the indicator pin,
The second rib is arranged at a position corresponding to a rear side of the hot water flow direction with respect to the indicator pin so as to be along the hot water flow direction, and is configured to run along the hot water flow direction. A cover member configured to have a downward slope toward the cover body . The cover member according to claim 1, wherein a plurality of the ribs are provided. Cover member according to claim 1 or 2, wherein the second rib is configured to be multiply provided. A cylinder head,
A camshaft rotatably supported by the cylinder head;
A cylinder block to which the cylinder head is fastened;
A crankshaft rotatably supported by the cylinder block;
A timing chain that is wound around the camshaft and the crankshaft and transmits rotation of the crankshaft to the camshaft;
The cover member according to any one of claims 1 to 3 , wherein the cover member is fastened to the cylinder head and the cylinder block so as to cover the timing chain.
A crank pulley attached to a tip end of the crankshaft of the crankshaft protruding from the cover member,
With
The indicator pin is configured to be arranged near the crank pulley, a timing mark is provided on the crank pulley, and at least one of ignition timing and valve timing is configured to be adjustable by the indicator pin and the timing mark. Is an internal combustion engine.

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