JP5592866B2 - Cover structure of internal combustion engine - Google Patents

Description

  The present invention relates to a cover structure for an internal combustion engine.

  Generally, a projecting portion that projects toward the internal combustion engine body is provided on the inner surface (back surface) of a chain case that covers a timing chain that transmits the rotation of the crankshaft of the engine to the camshaft.

  For example, in Patent Document 1, a plurality of central fastening portions that are formed to protrude from the inner surface of the chain case and are abutted against the engine body and fastened by bolts are formed between the central fastening portions that are formed to protrude from the inner surface of the chain case. An invention is disclosed that includes a connecting portion that is connected and abutted against an engine body.

JP 2002-130051 A

  By the way, when protrusion parts, such as the said center fastening part and a connection part, are provided, there exists a possibility that the lubricating oil which flowed along the inner surface of a chain case may retain on the upper surface of a protrusion part. For this reason, there has been a desire to suppress the retention of lubricating oil.

  The present invention has been developed from such a viewpoint, and an object of the present invention is to provide a cover structure for an internal combustion engine that can suppress the retention of lubricating oil in the protruding portion.

In order to solve the above problems, the present invention provides a timing train mechanism provided on one side wall of an internal combustion engine body, a cover member that forms a timing train chamber between the internal combustion engine body and covers the timing train mechanism, A cover structure for an internal combustion engine comprising: the cover member provided at a pair of side edges spaced apart from each other; a side fastening part fastened to the internal combustion engine body; and the pair of side edges Projecting from the inner surface of the connecting wall portion toward the internal combustion engine main body and having a lubricating oil retention portion in which lubricating oil for lubricating the timing train mechanism stays, and from the inner surface of the wall portion toward the internal combustion engine main body And an upper rib portion provided above the lubricating oil retention portion in the cylinder axial direction, and the upper rib portion covers the lubricating oil retention portion from above in the cylinder axial direction. Inclined downward toward either one of the pair of side edges and is formed in a substantially straight shape, and the inclined rib lower side of the upper rib portion is more than the pair of protrusions and the lubricating oil retaining portion. The protrusion extends to any one of the side edges, and the projecting portion includes a plurality of main body portions that are spaced apart from each other by a predetermined distance, and a connecting portion that connects the main body portions, and the lubricating oil The staying part is formed at an upper part of the main body part and the connecting part, and the upper rib part forms a part of a first rib provided so as to surround the main body part and the connecting part. To do.

According to the present invention, since the upper rib portion is provided above the lubricant oil retention portion of the protruding portion in the cylinder axial direction, the lubricating oil flowing along the inner surface of the wall portion of the cover member is guided to the upper rib portion, It will flow along the said upper rib part. Thereby, the retention of the lubricating oil in the lubricating oil retention part of a protrusion part can be suppressed.
Further, according to the present invention, the upper rib portion is inclined downward toward one of the pair of side edge portions and is formed in a substantially linear shape, so that the upper rib portion is formed along the inner surface of the wall portion of the cover member. The lubricating oil that has flowed will flow smoothly and reliably through the upper rib due to its own weight. Thereby, retention of the lubricating oil in the upper rib portion can be suppressed.
Furthermore, according to the present invention, since the first rib is provided so as to surround the periphery of the main body portion and the connecting portion of the protruding portion, the retention of the lubricating oil in the protruding portion can be further suppressed.

  The protruding end surface of the protruding portion is in contact with one side wall of the internal combustion engine main body, and the cover member further includes a seal member provided between the protruding portion and the internal combustion engine main body, It is preferable that the seal member is configured to be provided in the vicinity of the first rib.

  According to such a configuration, since the seal member provided between the protrusion and the internal combustion engine body is provided in the vicinity of the first rib, the rigidity in the vicinity of the seal member is improved, and the seal member with respect to the internal combustion engine body is improved. Since the adhesion is improved, a good sealing property can be secured.

  The cover member further includes a plurality of central fastening portions provided on the wall portion and fastened to the internal combustion engine main body, and the central fastening portions are spaced apart from each other by a predetermined interval around the protruding portion. It is preferable that the central fastening portion is provided so as to be connected by the first rib and at least a part of the seal member.

  According to such a configuration, the plurality of central fastening portions provided to be spaced apart from each other by a predetermined distance are connected by the first rib and at least a part of the seal member, so that between the central fastening portions, Since the first rib and at least a part of the seal member are disposed adjacent to each other, it is possible to secure even better sealing performance.

  The cover member further has a second rib protruding from the inner surface of the wall portion toward the internal combustion engine main body and extending along the cylinder axial direction, and the first rib has a substantially inverted triangular shape. Preferably, the lower end portion is formed and connected to the second rib.

  According to this configuration, since the first rib is formed in a substantially inverted triangular shape, the lubricating oil that has flowed along the inner surface of the wall of the cover member travels along the first rib and the lower end of the first rib. Will be collected. And since the lower end part of the 1st rib is connected with the 2nd rib extended along the direction of a cylinder axis, lubricating oil collected at the lower end part of the 1st rib is led to the 2nd rib. It becomes. Thereby, collection | recovery of lubricating oil can be performed rapidly.

  ADVANTAGE OF THE INVENTION According to this invention, the cover structure of the internal combustion engine which can suppress the retention of lubricating oil in a protrusion part can be provided.

It is a schematic block diagram of an engine provided with the cover structure of an internal combustion engine, (a) is a side view, (b) is a front view. It is a side view which shows the state which removed the chain case from the engine. It is a rear view of a chain case. It is a perspective view which shows the state which looked at the chain case from the cylinder axis direction diagonally downward. It is a partially omitted front view of the chain case. FIG. 4 is a partially enlarged perspective view showing the periphery of a first oil passage boss in FIG. 3. FIG. 4 is a partially enlarged perspective view showing the periphery of a variable valve boss part and a second oil passage boss part of FIG. 3. FIG. 8 is a partially enlarged perspective view showing a state in which a seal member is mounted on the variable valve boss portion and the second oil passage boss portion of FIG. 7. FIG. 6 is a partially enlarged perspective view showing the periphery of the strainer mounting portion of FIG. 5. It is the II sectional view taken on the line of FIG. It is the side view which showed the flow of lubricating oil typically. FIG. 12 is a partially enlarged side view of FIG. 11.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and redundant description is omitted. In the present embodiment, a case where the present invention is applied to an automobile engine will be described as an example. Moreover, when explaining a direction, it demonstrates based on the front-back, up-down, right-and-left of the vehicle shown in FIG.

  In the present embodiment, the vertical direction coincides with the vertical direction, and the cylinder axial direction is inclined forward by a predetermined angle with respect to the vertical direction (vertical direction). The axial direction is a direction parallel to the rotation centers of the crankshaft and the camshaft. Furthermore, the orthogonal direction is a direction orthogonal to the cylinder axial direction when viewed from the axial direction. The upper side is referred to as the upper side and the lower side is referred to as the lower side with respect to the cylinder orthogonal plane that is a plane orthogonal to the cylinder axial direction.

FIG. 1 is a schematic configuration diagram of an engine E provided with a cover structure for an internal combustion engine, in which (a) is a side view and (b) is a front view. FIG. 2 is a side view showing a state where the chain case 30 is removed from the engine E. FIG.
As shown in FIGS. 1 (a) and 1 (b), the engine E is, for example, a DOHC type in-line engine placed horizontally on a vehicle body. The engine E mainly includes an engine body 10, a timing train mechanism 20, and a chain case 30.

<Engine body>
As shown in FIG. 2, the engine body 10 includes a cylinder block 11, a lower block 12, a cylinder head 13, a head cover 14, and an oil pan 15.

<Cylinder block>
Although not shown, the cylinder block 11 is a member mainly constituting a cylinder bore and a crankcase. Inside the cylinder block 11, a piston, a connecting rod, a crankshaft 16 and the like are accommodated.

<Lower block>
The lower block 12 is a member that forms a crankcase together with the cylinder block 11, and is disposed below the cylinder block 11. An end portion of the crankshaft 16 is rotatably held between the side wall 11a of the cylinder block 11 and the side wall 12a of the lower block 12.

<Cylinder head>
The cylinder head 13 is a member that forms a combustion chamber together with the cylinder block 11, and is disposed above the cylinder block 11. Although not shown, an intake port and an exhaust port communicating with the combustion chamber are formed inside the cylinder head 13, and an intake valve, an exhaust valve, a rocker arm, and the like for opening and closing the intake port and the exhaust port are disposed. Is done. Two camshafts 17 are disposed above the cylinder head 13. The camshaft 17 constitutes an intake side camshaft 18 and an exhaust side camshaft 19. The intake side camshaft 18 and the exhaust side camshaft 19 are arranged side by side so that their axial directions are parallel to each other.

  A plurality of bolt insertion holes 10a, 10a are spaced along the extending direction at both ends in the width direction of the side wall 11a of the cylinder block 11, the side wall 12a of the lower block 12, and the side wall 13a of the cylinder head 13. It is formed by emptying.

<Head cover>
The head cover 14 is a lid-like member that closes the upper part of the cylinder head 13 and constitutes a valve operating chamber, and is disposed above the cylinder head 13. End portions of the intake side camshaft 18 and the exhaust side camshaft 19 are rotatably fixed to the side wall 14 a of the head cover 14.

<Oil pan>
The oil pan 15 is a member for receiving oil falling by lubricating each part in the engine E, and is disposed below the lower block 12. Inside the oil pan 15, an oil pump 15 a for pumping oil to each part in the engine E is disposed. One end side of the pump drive shaft 15 b of the oil pump 15 a protrudes from the side wall 15 c of the oil pan 15.

  The crankshaft 16 functions as a drive shaft, and the intake side camshaft 18, the exhaust side camshaft 19, and the pump drive shaft 15b each function as a driven shaft.

<Timing train mechanism>
The timing train mechanism 20 is a mechanism that transmits the rotational force of the crankshaft 16 to the pump drive shaft 15 b and the camshaft 17.
The timing train mechanism 20 includes a crank sprocket 21, cam sprockets 22A and 22B, an oil pump sprocket 23, a cam timing chain 24, an oil pump timing chain 25, a movable shoe 26A, and a first fixed shoe 26B. A second fixed shoe 26C, a first hydraulic tensioner device 27, a shoe 28, and a second hydraulic tensioner device 29.

<Crank sprocket>
The crank sprocket 21 that is a drive wheel is a gear member that is fixed to one end side of the crankshaft 16 protruding from the side surface of the engine body 10 and is configured to be rotatable integrally with the crankshaft 16. The crank sprocket 21 includes a first gear portion 21a having a large diameter and a second gear portion 21b having a small diameter. The first gear portion 21a is disposed closer to the engine body 10 than the second gear portion 21b. In the present embodiment, the crank sprocket 21 (crankshaft 16) rotates in the clockwise direction in FIG.

<Cam sprocket>
The cam sprockets 22 </ b> A and 22 </ b> B that are driven wheels are gear members that are fixed to one end sides of two camshafts 17 that protrude from the side surface of the engine body 10 and that can rotate integrally with the camshaft 17. . The cam sprocket 22 </ b> A is connected to the intake side camshaft 18, and the cam sprocket 22 </ b> B is connected to the exhaust side camshaft 19. As the cam sprockets 22A and 22B rotate, the intake side camshaft 18 and the exhaust side camshaft 19 rotate to open and close the intake and exhaust valves at a predetermined timing.

<Cam timing chain>
The cam timing chain 24 as a timing chain is an endless chain that transmits the rotational force of the crankshaft 16 to the camshaft 17, and is hung between the second gear portion 21b of the crank sprocket 21 and the cam sprockets 22A and 22B. Passed.

<Moving shoe>
The movable shoe 26 </ b> A serving as a sliding contact member is an elongate long member that is in sliding contact with the loose side (left side in FIG. 2) of the cam timing chain 24 and guides the cam timing chain 24. The upper end of the movable shoe 26A is fixed to the side wall 13a of the cylinder head 13 so as to be swingable. The lower end side of the movable shoe 26 </ b> A is urged toward the cam timing chain 24 by the first hydraulic tensioner device 27.

<First fixed shoe>
The first fixed shoe 26 </ b> B is a linear long member that slides into contact with the tension side portion of the cam timing chain 24 (the right side portion in FIG. 1) and guides the cam timing chain 24. The first fixed shoe 26 </ b> B is fixed by a plurality of bolts B and B across the side wall 11 a of the cylinder block 11 and the side wall 13 a of the cylinder head 13.

<Second fixed shoe>
The second fixed shoe 26C is a linear member that is disposed above the cam sprockets 22A and 22B, is in sliding contact with the cam timing chain 24, and guides the cam timing chain 24. The second fixed shoe 26C is fixed to the head cover 14.

<First hydraulic tensioner device>
The first hydraulic tensioner device 27 is a device that adjusts the tension of the cam timing chain 24 to be substantially constant by urging the movable shoe 26 </ b> A toward the cam timing chain 24. The first hydraulic tensioner device 27 includes a contact portion 27a that contacts the movable shoe 26A, a housing 27b that is fixed to the side wall 12a of the lower block 12, and a plunger 27c that protrudes from the housing 27b and presses the contact portion 27a. Have.

  The contact part 27a is a substantially triangular member disposed on the lower end side of the movable shoe 26A. The abutting portion 27 a has an inner lower end fixed to the side wall 11 a of the cylinder block 11 so as to be swingable. The outer lower end portion of the contact portion 27a is biased toward the movable shoe 26A by the plunger 27c.

  High pressure oil is supplied to the housing 27b from an oil supply oil passage (not shown) of the engine body 10. In this case, when the contact portion 27a is pressed toward the movable shoe 26A by the plunger 27c pushed out from the housing 27b (when it swings clockwise in FIG. 2), the movable shoe 26A is interposed via the contact portion 27a. Is pressed toward the cam timing chain 24, and the tension of the cam timing chain 24 is adjusted to be substantially constant.

<Sprocket for oil pump>
The oil pump sprocket 23 is a gear member fixed to the pump drive shaft 15 b protruding from the side wall 15 c of the oil pan 15. In this case, the pump drive shaft 15b rotates with the rotation of the oil pump sprocket 23, whereby the oil pump 15a is driven, and high-pressure oil passes through an oil supply passage (not shown) in various locations in the engine body 10. To be supplied.

<Timing chain for oil pump>
The oil pump timing chain 25 is an endless chain that transmits the rotational force of the crankshaft 16 to the pump drive shaft 15b, and is spanned between the first gear portion 21a of the crank sprocket 21 and the oil pump sprocket 23. It is.

<Shoe>
The shoe 28 is a member that contacts the loose side (the right side in FIG. 2) of the oil pump timing chain 25. The lower end of the shoe 28 is fixed to the second hydraulic tensioner device 29 so as to be swingable.

<Second hydraulic tensioner device>
The second hydraulic tensioner device 29 is a device that adjusts the tension of the oil pump timing chain 25 to be substantially constant by biasing the shoe 28 toward the oil pump timing chain 25. The second hydraulic tensioner device 29 includes a housing 29a fixed to the side wall 12a of the lower block 12, a plunger 29b that protrudes from the housing 29a and presses the shoe 28, and a hollow portion (not shown) formed in the housing 29a. A relief valve 29c to be accommodated.

  The housing 29a is a member that constitutes the body of the second hydraulic tensioner device 29, and includes an oil passage, a high hydraulic chamber, and the like therein. High pressure oil is supplied to the high hydraulic pressure chamber of the housing 29 a from an oil supply passage (not shown) of the engine body 10. In this case, the shoe 28 is pressed toward the oil pump timing chain 25 by the plunger 29b pushed out from the housing 29a, and the tension of the oil pump timing chain 25 is adjusted to be substantially constant.

  The relief valve 29c has a function of discharging oil from the relief hole 29c1 when the hydraulic pressure in the high hydraulic chamber of the housing 29a becomes equal to or higher than a predetermined value, and lubricating the timing train mechanism 20 using the discharged oil. The relief hole 29c1 of the relief valve 29c is formed so as to penetrate to the upper rear side of the housing 29a. The relief hole 29c1 can be provided at an arbitrary position of the housing 29a.

<Chain case>
Returning to FIG. 1, the chain case 30 as a cover member is fixed to one side surface of the engine body 10 and covers the cam timing chain 24 from the outside. That is, the chain case 30 forms a timing train chamber S (see FIG. 1B) with the engine body 10 and covers the cam timing chain 24.

FIG. 3 is a rear view of the chain case 30. FIG. 4 is a perspective view showing a state in which the chain case 30 is viewed obliquely from below in the cylinder axis direction. In FIG. 3, for convenience of explanation, the crankshaft 16, the second gear portion 21 b of the crank sprocket 21, and the cam timing chain 24 are drawn.
As shown in FIGS. 3 and 4, the chain case 30 is a member having a U shape in a sectional view, and a pair of side edge portions 31 and 32 that are separated from each other in the width direction (front-rear direction), and side edge portions. And a wall portion 33 that connects 31 and 32.

<Side edge>
The side edge portions 31, 32 are portions that protrude from the both end portions in the width direction of the wall portion 33 toward the engine body 10 and are abutted and fixed to the engine body 10. A plurality of bolt insertion holes 31a and 32a are formed through the side edge portions 31 and 32 at intervals along the extending direction. The bolt insertion holes 31a and 32a, which are side fastening portions, are provided at positions corresponding to the bolt insertion holes 10a (see FIG. 2) of the engine body 10.

<Wall>
FIG. 5 is a partially omitted front view of the chain case 30.
As shown in FIGS. 3 and 5, the wall 33 includes a hydraulic control valve mounting portion 34, a first oil passage boss portion 35, a variable valve boss portion 36, a strainer mounting portion 37, and a second oil. It mainly has a passage boss portion 38, a first fastening boss portion 39a to a third fastening boss portion 39c, and a plurality of ribs 40 and 40.

<Hydraulic control valve mounting part>
As shown in FIG. 5, the hydraulic control valve mounting portion 34 is provided on the upper side of the outer surface 33 a of the wall portion 33 and in the vicinity of the side edge portion 32, and is a portion to which a hydraulic control valve (not shown) is mounted. is there. The hydraulic control valve mounting portion 34 is formed to protrude from the outer surface 33a of the wall portion 33 by a predetermined length. Three circular holes 34a to 34c are formed through the hydraulic control valve mounting portion 34. The hole 34a communicates with the oil supply path of the hydraulic control valve, the hole 34b communicates with the oil discharge path of the hydraulic control valve, and the hole 34c communicates with the drain part of the hydraulic control valve.

<First oil passage boss>
FIG. 6 is a partially enlarged perspective view showing the periphery of the first oil passage boss portion 35 of FIG. 3.
As shown in FIG. 6, the first oil passage boss portion 35 is formed to protrude from the inner surface (the surface facing the engine body 10) 33 b of the wall portion 33 to the engine body 10 by a predetermined length. The protruding end surface of the first oil passage boss 35 abuts against one side surface of the engine body 10.
The first oil passage boss portion 35 includes an oil supply boss portion 35a and an oil discharge boss portion 35b.

  The oil supply boss portion 35a is a portion configured by arranging concentric and cylindrical portions having different diameters in an inner and outer double. A hole 35 a 1 communicating with a hole 34 a (see FIG. 5) of the hydraulic control valve mounting portion 34 and an oil passage (not shown) of the engine body 10 is formed in the inner cylindrical portion.

  The oil discharge boss portion 35b is formed in a substantially rectangular tube shape continuously from a concentric circular portion having different diameters arranged inside and outside and an outer peripheral surface of the outer cylindrical portion. And a portion. In the inner cylindrical portion, a hole portion 34b (see FIG. 5) of the hydraulic control valve mounting portion 34 and a hole portion 35b1 communicating with the oil passage (not shown) of the engine body 10 are formed. A hole 35b2 that communicates with the hole 34c of the hydraulic control valve mounting portion 34 is formed in the substantially square cylindrical portion.

  In this case, the hole 34a and the hole 35a1 function as an oil supply oil passage that supplies oil from the engine body 10 to the hydraulic control valve, and the hole 34b and the hole 35b1 oil from the hydraulic control valve to the engine body 10. It functions as an oil discharge oil passage that discharges oil. Further, the hole 34c and the hole 35b2 function as a drain oil passage D that supplies oil from the drain portion of the hydraulic control valve into the chain case 30.

<Voss for variable valve>
FIG. 7 is a partially enlarged perspective view showing the periphery of the variable valve boss portion 36 and the second oil passage boss portion 38 of FIG. 3.
As shown in FIG. 7, the variable valve boss portion 36 as the main body is a portion having a substantially egg-shaped hole portion 36d into which a control valve (not shown) for controlling the variable valve timing mechanism is inserted. The variable valve boss portion 36 is provided on the upper side of the wall portion 33 and in the center in the width direction. The variable valve boss 36 is formed to protrude from the inner surface 33b of the wall 33 to the engine main body 10 by a predetermined length, and to protrude from the opening edge of the hole 36d to the engine main body 10 by a predetermined length. And an inner edge portion 36b. The protruding end surfaces of the outer edge portion 36a and the inner edge portion 36b are in contact with one side surface of the engine body 10. A groove 36c is formed between the outer edge 36a and the inner edge 36b so as to be recessed toward the outer surface 33a of the wall 33. The control valve is attached to the cylinder head 13 (see FIG. 2) through the hole 36d of the variable valve boss 36.

<Second oil passage boss>
As shown in FIG. 7, the second oil passage boss portion 38 includes an oil supply boss portion 38 a provided at a predetermined distance on the lower rear side of the variable valve boss portion 36, and an oil supply boss portion. An oil return boss portion 38b for connecting the portion 38a and the variable valve boss portion 36 to each other.

  The oil supply boss 38a, which is the main body, is a portion having a substantially square cylindrical recess 38a4 communicating with an oil passage (not shown) of the engine main body 10. The oil supply boss 38a is formed to protrude from the inner surface 33b of the wall 33 to the engine body 10 by a predetermined length, and to protrude from the opening edge of the recess 38a4 to the engine body 10 by a predetermined length. An inner edge portion 38a2. The protruding end surfaces of the outer edge portion 38a1 and the inner edge portion 38a2 are in contact with one side surface of the engine body 10. A groove 38a3 is formed between the outer edge 38a1 and the inner edge 38a2 so as to be recessed toward the outer surface 33a of the wall 33.

  The oil return boss portion 38b as a connecting portion is a portion having a cylindrical hole portion 38b4 that communicates an oil passage (not shown) of the engine body 10 and a hole portion 37b of the strainer mounting portion 37. The oil return boss 38b is formed to protrude from the inner surface 33b of the wall 33 to the engine body 10 by a predetermined length, and to protrude from the opening edge of the hole 38b4 to the engine body 10 by a predetermined length. And an inner edge portion 38b2. The protruding end surfaces of the outer edge portion 38b1 and the inner edge portion 38b2 are in contact with one side surface of the engine body 10. A groove 38b3 is formed between the outer edge 38b1 and the inner edge 38b2 so as to be recessed toward the outer surface 33a of the wall 33.

FIG. 8 is a partially enlarged perspective view showing a state where the seal member 43 is mounted on the variable valve boss portion 36 and the second oil passage boss portion 38 of FIG. 7.
In the present embodiment, as shown in FIGS. 7 and 8, the outer edge portions 38a1 and 38b1 of the second oil passage boss portion 38 and the outer edge portion 36a of the variable valve boss portion 36 are integrally continuous (one stroke). Formed in a letter). Further, the groove portions 38a3, 38b3 of the second oil passage boss portion 38 and the groove portion 36c of the variable valve boss portion 36 are integrally formed continuously, and the groove portions 38a3, 38b3, 36c are formed of a single piece. The seal member 43 is attached (fitted).

  The seal member 43 is in close contact (pressure contact) with one side surface of the engine main body 10, and the inner space portions (hole portion 36d, recess portion 38a4, hole portion 38b4) and outer edge portions 36a, 38a1, and 38b1 of the inner edge portions 36b, 38a2, and 38b2. It is a member which seals between the outer space part of this airtight thru | or liquidtight. The seal member 43 has a shape corresponding to the groove portions 38 a 3, 38 b 3, and 36 c and is provided in the vicinity of the first rib 41.

<Strainer mounting part>
FIG. 9 is a partially enlarged perspective view showing the periphery of the strainer mounting portion 37 of FIG.
As shown in FIG. 9, the strainer attaching portion 37 is a portion provided below the variable valve boss portion 36 and to which a strainer (not shown) is attached. The strainer attachment portion 37 is formed to protrude from the outer surface 33a of the wall portion 33 by a predetermined length. The strainer mounting portion 37 is formed with a substantially square cylindrical concave portion 37a and a cylindrical hole portion 37b having a predetermined volume. The recess 37a and the hole 37b communicate with the strainer.

10 is a cross-sectional view taken along the line II of FIG.
As shown in FIGS. 5 and 10, the recess 38 a 4 of the second oil passage boss 38 is provided with a position shifted in the width direction with respect to the recess 37 a of the strainer mounting portion 37. As shown in FIG. 10, a communication path 33c is formed between the recess 38a4 and the recess 37a. One end of the communication path 33c opens to the side surface of the recess 38a4, and the other end opens to the bottom surface of the recess 37a.

  In this case, the recess 38a4, the communication path 33c, and the recess 37a function as an oil supply oil passage that supplies oil from the engine body 10 to the strainer, and the hole 37b and the hole 38b4 supply oil from the strainer to the engine body 10. It functions as a return oil passage. Further, the recess 38a4 also functions as a chamber.

<Boss part for fastening>
As shown in FIG. 7, the first fastening boss portion 39a to the third fastening boss portion 39c, which are central fastening portions, are cylindrical portions that are fixed to one side surface of the engine body 10 with bolts (not shown). . Each fastening boss portion 39 a-39 c is formed to protrude from the inner surface 33 b of the wall portion 33 to the engine main body 10 by a predetermined length, and its protruding end surface abuts against one side surface of the engine main body 10. The fastening boss portions 39a to 39c are provided around the variable valve boss portion 36 and the second oil passage boss portion 38 with a space therebetween. Specifically, the first fastening boss 39 a is disposed in front of the variable valve boss 36. The second fastening boss portion 39b is provided obliquely downward and rearwardly with respect to the first fastening boss portion 39a and is disposed obliquely upward and rearward of the oil supply boss portion 38a. The third fastening boss part 39c is provided between the first fastening boss part 39a and the second fastening boss part 39b, and is provided at a predetermined distance from the front diagonally downward or the rear diagonally downward. It arrange | positions under the boss | hub part 38 for oil passages.

  In the present embodiment, a recess 30A is formed between the chain case 30 and the engine body 10 so as to open upward. The recess 30A as a lubricating oil retaining portion is formed by being surrounded by the outer edge portion 36a of the variable valve boss portion 36, the outer edge portions 38a1 and 38b1 of the second oil passage boss portion 38, and the second fastening boss portion 39b. . The recess 30A is a portion where oil for lubricating the timing train mechanism 20 stays when the upper rib portion 41a of the first rib 41 described later is not provided.

<Rib>
As shown in FIGS. 3 and 4, the rib 40 protrudes from the inner surface 33 b of the wall portion 33 to the engine main body 10, and a plurality of ribs 40 are formed along the cylinder axial direction, the orthogonal direction, the vertical direction, the front-rear direction, and the like. .
The rib 40 mainly includes a first rib 41 and a second rib 42.

The first rib 41 is disposed so as to surround the variable valve boss portion 36 and the second oil passage boss portion 38, and connects the first fastening boss portion 39a and the third fastening boss portion 39c, respectively. It is a substantially inverted triangular rib.
As shown in FIGS. 7 and 8, the first rib 41 includes an upper rib portion 41a, a rear lower rib portion 41b, and a front lower rib portion 41c.

  The upper rib portion 41a is a substantially linear portion that is disposed between the first fastening boss portion 39a and the second fastening boss portion 39b and is provided above the concave portion 30A in the cylinder axial direction. The upper rib portion 41a is divided at one location in the length direction by the variable valve boss portion 36, and an upper end portion 41a1 positioned between the first fastening boss portion 39a and the variable valve boss portion 36, A lower end portion 41a2 positioned between the variable valve boss portion 36 and the second fastening boss portion 39b. The lower end portion 41a2 is inclined downward toward the side edge portion 31 from the variable valve boss portion 36 toward the second fastening boss portion 39b. A part of the seal member 43 is disposed between the upper end portion 41a1 and the lower end portion 41a2 (see FIG. 8). That is, in the present embodiment, the first fastening boss portion 39 a and the second fastening boss portion 39 b are connected by a part of the upper rib portion 41 a and the seal member 43.

  The rear lower rib portion 41b is a substantially linear portion disposed between the second fastening boss portion 39b and the third fastening boss portion 39c. The rear lower rib portion 41b is divided at one place in the length direction by an oil supply boss portion 38a, and an upper end portion 41b1 located between the second fastening boss portion 39b and the oil supply boss portion 38a. And a lower end 41b2 positioned between the oil supply boss 38a and the third fastening boss 39c. The upper end portion 41b1 is inclined downward toward the side edge portion 32 (see FIG. 3) as it goes from the second fastening boss portion 39b to the oil supply boss portion 38a. Further, the lower end portion 41b2 is inclined downward toward the side edge portion 32 as it goes from the oil supply boss portion 38a to the third fastening boss portion 39c. The lower end 41b2 is connected to the second rib 42 via the third fastening boss 39c. A part of the seal member 43 is disposed between the upper end portion 41b1 and the lower end portion 41b2 (see FIG. 8). That is, in the present embodiment, the second fastening boss portion 39 b and the third fastening boss portion 39 c are connected by the rear lower rib portion 41 b and a part of the seal member 43.

  The front lower rib portion 41c is a substantially linear portion disposed between the first fastening boss portion 39a and the third fastening boss portion 39c. The front lower rib portion 41c is divided at one place in the length direction by the variable valve boss portion 36, and an upper end portion 41c1 positioned between the first fastening boss portion 39a and the variable valve boss portion 36, And a lower end portion 41c2 located between the variable valve boss portion 36 and the third fastening boss portion 39c. The upper end portion 41 c 1 is inclined downward toward the side edge portion 31 as it goes from the first fastening boss portion 39 a toward the variable valve boss portion 36. Further, the lower end portion 41c2 is inclined downward toward the side edge portion 31 from the variable valve boss portion 36 toward the third fastening boss portion 39c. The lower end portion 41c2 is connected to the second rib 42 via the third fastening boss portion 39c. A part of the seal member 43 is disposed between the upper end portion 41c1 and the lower end portion 41c2 (see FIG. 8). That is, in the present embodiment, the first fastening boss portion 39 a and the third fastening boss portion 39 c are connected by a part of the front lower rib portion 41 c and the seal member 43.

  Returning to FIGS. 3 and 4, the second rib 42 has an upper end (one end) continuous to the third fastening boss 39 c and a lower end (the other end) positioned near (directly above) the crank sprocket 21. Thus, the rib extends along the cylinder axial direction. As shown in FIG. 3, the second rib 42 is provided inside the cam timing chain 24 (that is, an area surrounded by the cam timing chain 24).

  In addition, on the lower end side of the chain case 30, a crankshaft insertion hole 30 </ b> B into which the crankshaft 16 is inserted, an opening 30 </ b> C through which the first hydraulic tensioner device 27 (see FIG. 1A) can be visually recognized, etc. Is formed through.

  The engine E provided with the cover structure for the internal combustion engine according to the present embodiment is basically configured as described above. Next, mainly referring to FIGS. The effect will be described. FIG. 11 is a side view schematically showing the flow of the lubricating oil, and FIG. 12 is a partially enlarged side view of FIG.

  As shown in FIG. 2, when the crankshaft 16 is rotated by starting the engine E, the crank sprocket 21 attached to the crankshaft 16 is rotated, and the rotation is transmitted to the cam sprockets 22A and 22B by the cam timing chain 24. As the cam sprockets 22A and 22B rotate, the two camshafts 17 rotate. Thereby, an intake valve and an exhaust valve (not shown) are opened and closed at a predetermined timing.

  On the other hand, the rotation of the crank sprocket 21 is transmitted to the oil pump sprocket 23 by the oil pump timing chain 25, and the pump drive shaft 15b rotates with the rotation of the oil pump sprocket 23. As a result, the oil pump 15 a is driven, the oil in the oil pan 15 is pumped up, and the oil is supplied to each part of the engine E.

  A part of the oil is supplied into the chain case 30 via the meshing portions of the cam sprocket 22A and the cam timing chain 24.

As shown in FIG. 11, the oil supplied into the chain case 30 from the meshing portions of the cam sprocket 22 </ b> A and the cam timing chain 24 flows downward along the inner surface 33 b of the wall portion 33.
As shown in FIG. 12, when the oil flowing along the wall portion 33 reaches the lower end portion 41a2 of the upper rib portion 41a, it flows along the lower end portion 41a2 toward the second fastening boss portion 39b.

  At this time, since the lower end portion 41a2 of the upper rib portion 41a is inclined downward toward the side edge portion 31, the oil surely flows toward the second fastening boss portion 39b by its own weight.

  Subsequently, when the oil reaches the second fastening boss portion 39b, the oil flows along the outer peripheral surface of the second fastening boss portion 39b toward the upper end portion 41b1 of the rear lower rib portion 41b.

  Subsequently, when the oil reaches the upper end portion 41b1 of the rear lower rib portion 41b, it passes through the upper end portion 41b1, the outer edge portion 38a1 of the second oil passage boss portion 38, and the lower end portion 41b2 of the rear lower rib portion 41b. It flows toward the third fastening boss 39c.

  At this time, since the upper end portion 41b1 and the lower end portion 41b2 of the rear lower rib portion 41b are inclined downward toward the side edge portion 32, the oil surely moves toward the third fastening boss portion 39c by its own weight. Flowing.

Subsequently, when the oil reaches the third fastening boss portion 39c, the oil flows toward the second rib 42 along the outer peripheral surface of the third fastening boss portion 39c.
As shown in FIG. 11, when the oil reaches the second rib 42, the crank sprocket 21, the cam timing chain 24, and the oil pump timing chain 25 (see FIG. 2) mesh with each other through the second rib 42. It flows toward the part.

  On the other hand, as shown in FIG. 12, when the oil flowing along the wall portion 33 reaches the upper end portion 41a1 of the upper rib portion 41a and the first fastening boss portion 39a, the outer peripheral surface of the first fastening boss portion 39a. And flows toward the upper end portion 41c1 of the front lower rib portion 41c.

  Subsequently, when the oil reaches the upper end portion 41c1 of the front lower rib portion 41c, it is transferred to the upper end portion 41c1, the outer edge portion 36a of the variable valve boss portion 36, and the lower end portion 41c2 of the front lower rib portion 41c for the third fastening. It flows toward the boss part 39c.

  At this time, since the upper end portion 41c1 and the lower end portion 41c2 of the front lower rib portion 41c are inclined downward toward the side edge portion 31, the oil surely flows toward the third fastening boss portion 39c by its own weight. .

Subsequently, when the oil reaches the third fastening boss portion 39c, the oil flows toward the second rib 42 along the outer peripheral surface of the third fastening boss portion 39c.
As shown in FIG. 11, when the oil reaches the second rib 42, the oil flows toward the meshing portion of the crank sprocket 21, the cam timing chain 24, and the oil pump timing chain 25 through the second rib 42. .

According to the present embodiment described above, since the lower end portion 41a2 of the upper rib portion 41a is provided above the concave portion 30A serving as the lubricating oil retention portion in the cylinder axial direction, the lubricating oil flowing along the inner surface 33b of the wall portion 33 is provided. Is guided to the lower end portion 41a2 of the upper rib portion 41a and flows along the lower end portion 41a2 of the upper rib portion 41a. Thereby, the retention of oil in the recess 30A can be suppressed.
In particular, in the present embodiment, the first rib 41 is disposed so as to surround the periphery of the variable valve boss portion 36 and the second oil passage boss portion 38, so that the variable valve boss portion 36 including the recess 30A and Oil retention in the second oil passage boss 38 can be further suppressed.

  In this embodiment, each rib part 41a-41c which comprises the 1st rib 41 inclines downward toward either the side edge part 31 or the side edge part 32, and is formed in substantially linear form. The oil flows smoothly and reliably through the rib portions 41a-41c by its own weight. Thereby, the retention of oil in the first rib 41 can be suppressed.

In this embodiment, since the seal member 43 is provided in the vicinity of the first rib 41, the rigidity in the vicinity of the seal member 43 is improved, and the adhesion of the seal member 43 to the engine body 10 is improved. Secure sealing performance.
In particular, in this embodiment, between each fastening boss | hub part 39a-39c is connected by the 1st rib 41 and a part of seal member 43, the 1st rib 41 and a part of seal member 43 are connected. Since they are arranged adjacent to each other, it is possible to secure even better sealing performance.

  In this embodiment, since the 1st rib 41 is formed in a substantially inverted triangle shape, the oil which flowed along the inner surface 33b of the wall part 33 is transmitted along each rib part 41a-41c of the 1st rib 41. It will be collected by the lower end parts 41b2 and 41b3. Since the lower end portions 41b2 and 41b3 are connected to the upper end portion of the second rib 42 via the third fastening boss portion 39c, the oil collected in the lower end portions 41b2 and 41b3 is the second rib 42. Will be led to. Thereafter, the oil is guided to the meshing portions of the crank sprocket 21, the cam timing chain 24, and the oil pump timing chain 25 through the second rib 42. Thereby, oil can be collected quickly.

  As mentioned above, although embodiment of this invention was described in detail with reference to drawings, this invention is not limited to this, In the range which does not deviate from the main point of invention, it can change suitably.

  In the present embodiment, the present invention is applied to the engine E for automobiles, but may be applied to engines other than automobiles such as ships and general-purpose machines.

  In the present embodiment, the present invention is applied to the serial type engine E. However, the present invention may be applied to other types of engines (for example, a V-type engine).

  In the present embodiment, the cylinder axis direction is inclined at a predetermined angle forward with respect to the vertical direction (vertical direction), but the cylinder axis direction may be inclined at a predetermined angle rearward with respect to the vertical direction. It is good also as a structure corresponding to an up-down direction (vertical direction).

  In the present embodiment, the plurality of (two) protruding portions of the variable valve boss portion 36 and the second oil passage boss portion 38 form the lubricating oil retention portion (recessed portion 30A), but lubrication is performed by a single protruding portion. An oil retention part may be formed.

  In the present embodiment, the present invention is applied to the projecting portions of the variable valve boss portion 36 and the second oil passage boss portion 38 having portions that communicate between the inside and the outside of the chain case 30, but the inside and outside of the chain case 30 are communicated. You may apply this invention to the other protrusion part which does not have a part.

  In the present embodiment, the first rib 41 includes the upper rib portion 41a, the rear lower rib portion 41b, and the front lower rib portion 41c. However, the first rib 41 is a cylinder of at least the recess 30A. It may be configured to have an upper rib portion 41a disposed on the upper side in the axial direction, and both or one of the rear lower rib portion 41b and the front lower rib portion 41c may be omitted.

In the present embodiment, the upper rib portion 41a has been divided at one location in the longitudinal direction by the variable valve boss portion 36, the upper rib portion 41a is disposed on the upper side of the variable valve boss portion 36, an upper end parts 41a1 and the lower end portion 41a2 may be formed integrally and continuously.

E engine (internal combustion engine)
S Timing train chamber 10 Engine body (Internal combustion engine body)
20 Timing train mechanism 30 Chain case (cover member)
30A Concavity (lubricating oil retention part)
31 Side edge part 31a Bolt insertion hole (side fastening part)
32 Side edge portion 32a Bolt insertion hole (side fastening portion)
33 Wall portion 33b Inner surface 36 Variable valve boss portion (protruding portion, main body portion)
38 2nd oil passage boss 38a Oil supply boss (projection, body)
38b Boss part for oil return (connecting part)
39a First fastening boss part (central fastening part)
39b Second fastening boss part (central fastening part)
39c Third fastening boss part (central fastening part)
40 rib 41 first rib 41a upper rib portion 41a1 upper end portion 41a2 lower end portion 41b rear lower rib portion 41b1 upper end portion 41b2 lower end portion 41c front lower rib portion 41c1 upper end portion 41c2 lower end portion 42 second rib 43 seal member

Claims (4)

A cover structure for an internal combustion engine, comprising: a timing train mechanism provided on one side wall of the internal combustion engine body; and a cover member that forms a timing train chamber between the internal combustion engine body and covers the timing train mechanism. And
The cover member is
A side fastening portion provided at a pair of side edge portions spaced apart from each other and fastened to the internal combustion engine body;
A protruding portion having a lubricating oil retention portion that protrudes from the inner surface of the wall portion connecting the pair of side edge portions toward the internal combustion engine main body and in which lubricating oil for lubricating the timing train mechanism is retained;
An upper rib portion projecting from the inner surface of the wall portion toward the internal combustion engine main body and provided above the lubricating oil retention portion in the cylinder axial direction;
Have
The upper rib portion is inclined downward toward one of the pair of side edge portions so as to cover the lubricating oil retention portion from above in the cylinder axial direction, and is formed in a substantially linear shape,
The inclined lower side of the upper rib portion extends to either one of the pair of side edge portions rather than the protruding portion and the lubricating oil retention portion ,
The protruding portion has a plurality of main body portions provided at a predetermined interval, and a connecting portion that connects between the main body portions,
The lubricating oil retention part is formed on the main body part and the connection part,
The cover structure for an internal combustion engine, wherein the upper rib portion forms a part of a first rib provided so as to surround the main body portion and the connecting portion . The protruding end surface of the protruding portion is in contact with one side wall of the internal combustion engine body,
The cover member further includes a seal member provided between the protruding portion and the internal combustion engine main body,
The seal member, the cover structure for an internal combustion engine according to claim 1, characterized in that provided in the vicinity of the first rib. The cover member further includes a plurality of central fastening portions provided on the wall portion and fastened to the internal combustion engine body.
The central fastening portion is provided around the protrusion and spaced apart from each other by a predetermined distance.
The internal combustion engine cover structure according to claim 2 , wherein the central fastening portion is connected by the first rib and at least a part of the seal member. The cover member further has a second rib protruding from the inner surface of the wall portion toward the internal combustion engine body and extending along the cylinder axial direction,
Wherein the first rib is formed substantially in an inverted triangle shape, the cover of the internal combustion engine according to any one of claims 1 to 3 lower end, characterized in that it is connected to the second rib Construction.

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