JP5287313B2 - Internal combustion engine seal structure - Google Patents

Description

  The present invention relates to a seal structure for an internal combustion engine comprising a seal for preventing leakage of cooling water and a seal for preventing leakage of lubricating oil, which are disposed in a portion that defines a cooling water passage and a lubricating oil chamber of the internal combustion engine. The present invention relates to a seal structure of an internal combustion engine suitable for confirming the performance of both seals in the assembled state as an internal combustion engine.

  Conventionally, a seal structure has been proposed in which an internal combustion engine leakage prevention seal and a lubrication oil leakage prevention seal are arranged in series between a cooling water passage and a lubricating oil chamber (Patent Document 1). reference).

  This is because when the water pump is mounted on the cylinder block wall surface of the cam chain chamber, the cooling water leakage prevention seal and the lubricating oil are placed on the fitting portion between the cylinder block side mounting hole and the water pump side fitting protrusion. A leakage prevention seal is arranged in series. In other words, a cooling water sealing material is provided on the side where the cooling water passage is located, and an oil sealing material is provided on the chain chamber side. When it leaks from the seal part, the cooling water and the lubricating oil are prevented from mixing.

Japanese Patent Application Laid-Open No. 06-299851

  By the way, in an engine etc., the leakage of cooling water and lubricating oil is prevented by a large number of seal parts, so all supplementary items such as a water pump are assembled in the engine body and filled with cooling water and lubricating oil. After completion of the operation as an engine, in order to prevent leakage of cooling water and lubricating oil, pressure is applied to each fluid to check for leaks in a large number of seal portions.

  However, in the above conventional example, the seal for preventing leakage of the cooling water and the seal for preventing leakage of the lubricating oil are merely arranged in series with a space between the chain chamber and the cooling water passage. Therefore, if one of the sealing functions is incomplete and there is a leak, the leaked cooling water or lubricating oil will pass through the other seal, causing a problem that the cooling water and the lubricating oil are mixed. There is a problem that cannot be confirmed from the outside. In addition, the water pump can be disassembled to check for leaks, but this does not guarantee the sealing function after re-installation in the engine body. Even if is incomplete, there is a problem that cannot be confirmed from the outside.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a seal structure for an internal combustion engine suitable for confirmation of seal performance.

According to the present invention, a space is formed between a coolant leakage prevention seal and a lubricant leakage prevention seal disposed at a portion defining a cooling water passage and a lubricating oil chamber of an internal combustion engine, and One end is opened at the bottom of the space, and the other end is opened to the external space of the internal combustion engine. The seal for preventing leakage of cooling water and the seal for preventing leakage of lubricating oil It is arranged on the inner peripheral side and the outer peripheral side between the members to be contacted, and prevents leakage from the inner peripheral side to the outer peripheral side and leakage from the outer peripheral side to the inner peripheral side, respectively. The space portion is formed by an annular groove provided on the surface of at least one of the members facing each other between the seals, and the passage is formed by opening one end below the annular groove in the gravity direction. It was like that.

Therefore, in the present invention, a space is formed between the coolant leakage prevention seal and the lubricant leakage prevention seal, and one end is opened at the bottom of the space portion, and the other end is the external space of the internal combustion engine. Since the leaked cooling water or lubricating oil is discharged to the outside without passing through the O-ring that performs the other sealing function, the above-described lubricating oil and cooling water Mixing can be eliminated, and the leaked cooling water or lubricating oil is discharged to the external space through the hole, so that the sealing function is good only by checking the opening of the hole to the external space. The quality against the absence of leakage can be guaranteed.
Moreover, the coolant leakage prevention seal and the lubricating oil leakage prevention seal are arranged on the inner peripheral side and the outer peripheral side between the members that contact the end surfaces, and from the inner peripheral side to the outer peripheral side of the mutual contact surfaces. And the leakage from the outer peripheral side to the inner peripheral side, and the space portion is an annular groove provided on the surface of at least one member facing each other between the seals. The passage is formed by opening one end below the annular groove in the gravitational direction. Therefore, when one of the seals is defective and coolant or lubricating oil leaks, the passage is formed in the annular groove. Since it flows toward one end of the seal and does not remain in the middle of the annular groove even if it leaks at any part of the seal, it always comes out to the opening facing the external space through the passage. Goods can be confirmed, and there are no leaks There can be guaranteed.

The front view which shows the outline of the engine cooling piping by which the sealing structure of the internal combustion engine which shows one Embodiment of this invention is implemented. The schematic sectional drawing which follows the AA line in FIG. The perspective view which shows the outline of an engine cooling device. Sectional drawing of the seal structure of the internal combustion engine in this embodiment. The front view of the sealing surface (E arrow) in the sealing structure of the internal combustion engine in FIG. The transverse cross section of the seal structure of the internal-combustion engine of the 1st example in the 2nd embodiment of the present invention. The longitudinal cross-sectional view which follows the FF line | wire of FIG. The transverse cross section of the seal structure of the internal-combustion engine of the 2nd example in the 2nd embodiment of the present invention. The longitudinal cross-sectional view which follows the GG line of FIG.

  Hereinafter, the seal structure of the internal combustion engine of the present invention will be described based on each embodiment.

(First embodiment)
1 to 5 show a first embodiment of a seal structure of an internal combustion engine to which the present invention is applied, and FIGS. 1 to 3 are front views and schematic views showing an outline of an engine cooling pipe in which the seal structure of the internal combustion engine is implemented. Cross-sectional views and perspective views, FIGS. 4 and 5 are a cross-sectional view of a seal structure and a front view of a seal surface in the present embodiment.

  FIG. 1 is a schematic front view of a V-type multi-cylinder engine. A pair of silent chains 6 are arranged in front of a cylinder block 1 so as to be wound around a main sprocket 5 provided at the front end of a crankshaft. The other end of each silent chain 6 is wound around each driven sprocket 7 that drives a cam mechanism disposed on each cylinder head 2 (see FIG. 2) fixed on each bank of the V-shaped cylinder block 1. It is hung. And it is attached to the front end of the cylinder block 1 and the cylinder head 2 and covers the main sprocket 5, each driven sprocket 7, and each silent chain 6, and is housed in a chain case 4 whose outer shape is shown by a two-dot chain line. Is done. As shown in FIG. 2, the lower portion of the chain case 4 is also fixed to the front end of a ladder frame 3 (see FIG. 3 for a specific shape) constituting the crankcase. The chain case 4 is configured to be supplied with lubricating oil for lubricating the silent chain 6 and the sprockets 5 and 7. Therefore, the lubricating oil is scattered in the chain case 4.

  As shown in FIG. 3, a water pump 8 for supplying cooling water to the cylinder block 1 is disposed in the space between both banks of the cylinder block 1, and the cooling water discharged from the water pump 8 is discharged from the discharge pipe. 9 (see arrow C in FIG. 3) and the cooling water passage 10 (see arrow D in FIG. 3) are supplied to the water jackets 11 of the cylinder blocks 1 in both banks. That is, the discharge pipe 9 is located in front of the chain case 4 and is supplied to the water jacket 11 of the cylinder block 1 through a cooling water passage 10 provided through the chain case 4 as shown in FIG. . By providing the cooling water passage 10 through the chain case 4, the cooling water can be efficiently supplied to the water jacket 11 of the cylinder block 1 in the shortest distance.

  As shown in FIG. 4, the cooling water passage 10 provided in the chain case 4 has a part of the chain case 4 as a thick part 20 that contacts the cylinder block 1, and the cylinder block extends from the outer surface of the thick part 20. A through hole reaching 1 is formed, and this through hole is formed in communication with the cooling water passage 12 formed in the cylinder block 1. On the contact surface of the thick portion 20 with the cylinder block 1, the lubricating oil of the chain chamber 4 </ b> A exists on the outer periphery, and the cooling water flowing through the cooling water passage 10 exists on the inner periphery.

  On the contact surface of the thick portion 20 with the cylinder block 1, as shown in FIG. 5, an annular ring groove 21, an annular groove 23 for accommodating an oil-resistant O-ring 22 and a water-resistant structure are provided from the outer peripheral side. A ring groove 24 for receiving the O-ring 25 is formed. And the through-hole 26 which penetrates the thick part 20 and penetrates to the outer surface of the chain case 4 is formed in the state where the annular groove 23 is communicated with the lower end in the gravity direction of the annular groove 23 located in the middle. Yes. The through hole 26 has a small diameter on the cylinder block 1 side communicating with the annular groove 23, and is formed in a tapered shape having a large diameter on the outer surface side of the chain case 4. The lower surface is formed to have a continuous downward gradient from the cylinder block 1 side toward the outer surface of the chain case 4. Further, a step 27 formed by cutting out the thick portion 20 is formed at the lower end in the gravitational direction of the opening of the through hole 26 that is opened on the outer surface of the chain case 4.

  The chain case 4 is provided with a gasket having a sealing function on an outer peripheral edge (not shown), and an oil-resistant O-ring 22 is inserted into the ring groove 21 on the outer peripheral side of the thick wall portion 20. A water-resistant O-ring 25 is inserted into the ring groove 24. The main block of the cylinder block 1, the cylinder head 2, and the ladder frame 3 are not shown so that the main sprocket 5, each driven sprocket 7, and each silent chain 6 are accommodated inside the chain chamber 4A. By fixing with a fixing bolt, it is mounted on the engine body. Thereafter, the water pump 8 is fixed to the engine body, and a discharge port (not shown) of the water pump 8 and the cooling water passage 10 of the thick wall portion 20 of the chain case 4 are connected by the cooling water pipe 9 to cool the portion. Piping is completed.

  In the seal structure of the internal combustion engine having the above-described configuration, the cooling water discharged from the water pump 8 is introduced into the cooling water passage 10 through the cooling water pipe 9, and the water is passed through the cooling water passage 12 of the cylinder block 1. It is supplied to the jacket 11. The cooling water passing through the cooling water passage 10 is sealed by the O-ring 25 inserted into the ring groove 24 on the inner peripheral side of the thick part 20 of the chain case 4, and further leakage to the outer peripheral part is prevented. .

  The chain chamber 4A formed by the chain case 4 and the front ends of the cylinder block 1, the cylinder head 2 and the ladder frame 3 is supplied with lubricating oil to the meshing portions with the sprockets 5 and 7 of the timing chain 6. Is done. The lubricating oil in the chain chamber 4A is sealed by the O-ring 22 inserted in the ring groove 21 on the outer peripheral side of the thick portion 20 of the chain case 4, and further leakage to the inner peripheral portion is prevented.

  Therefore, in order to prevent leakage of cooling water and lubricating oil of the assembled engine, when both of the O-rings 22 are checked by applying pressure to each fluid and checking for leaks in a large number of seal portions. , 25, the annular groove 23 disposed between the O-rings 22 and 25 does not leak cooling water or lubricating oil. For this reason, by confirming that the coolant and the lubricating oil are not leaking from the through hole 26 communicating with the annular groove 23, it is confirmed that the both seal functions of this portion are complete. It can be confirmed visually from the outside.

  However, when either one of the sealing functions is incomplete or the O-rings 22 and 25 are not attached, leakage of cooling water or lubricating oil to be sealed occurs from the sealing portion. To do. The leaked cooling water or lubricating oil flows into the annular groove 23 provided between the seals 22 and 25, and the outside of the chain case 4 through the through-hole 26 communicating with the annular groove 23 in the lower part of the gravity direction. It accumulates in the stepped portion 27 on the surface.

  When the space between both O-rings is closed as in the prior art, the leaked cooling water or lubricating oil remains collected between the other O-rings, and the other O-ring Incomplete or exposed to a different liquid for a long period of time, the oil passes through the O-ring and leaches into the other liquid region, resulting in a problem that cooling water and lubricating oil are mixed. However, in the present embodiment, since the annular groove 23 communicating with the outside through the through hole 26 is formed between the O-rings 22 and 25, the leaked cooling water or lubricating oil performs the other sealing function. Since the oil is discharged to the outside without passing through the O-rings 25 and 22 to be exhibited, the above-described mixing of the lubricating oil and the cooling water can be eliminated.

  For this reason, it can be confirmed that an abnormality has occurred in one of the sealing functions by visually confirming that the liquid has accumulated in the stepped portion 27. Then, by confirming whether the liquid accumulated in the stepped portion 27 is cooling water or lubricating oil, it is possible to know which sealing function is defective. Moreover, when both sealing functions are incomplete, both cooling water and lubricating oil will accumulate in the level | step-difference part 27, and it can confirm that both sealing functions are incomplete.

  Therefore, when these sealing functions are incomplete, the chain case 4 is removed from the engine body and repaired / replaced to prevent the engine with the incomplete sealing function from flowing downstream in the manufacturing process. That is, at the time of completion inspection of the engine, it is possible to detect and repair defects due to o-rings 22 and 25 having a shape defect or forgotten assembly at an early stage. This also leads to a reduction in repair man-hours accompanied by significant disassembly.

  In addition, it can be confirmed at an early stage that deterioration has occurred in any of the sealing functions by visually confirming that liquid has accumulated in the stepped portion 27 during periodic inspections during use of the engine. Then, by confirming whether the liquid accumulated in the stepped portion 27 is cooling water or lubricating oil, it is possible to know which sealing function has deteriorated. Further, when both the sealing functions are deteriorated, both the cooling water and the lubricating oil are accumulated in the step portion 27, and it can be confirmed at an early stage that both the sealing functions are deteriorated.

  In the above-described embodiment, the O-rings 22 and 25 inserted into the ring grooves 21 and 24 have been described as exhibiting the sealing function. However, other methods that exhibit the sealing function, such as gaskets and seals, are used. It may be a ring.

  Further, the ring grooves 21 and 24 and the annular groove 23 provided on the end face of the thick part 20 have been described as having circular shapes, but may be elliptical or non-circular as long as they are annular. .

  In addition, although the description has been given of the tapered through hole 26 provided to communicate with the annular groove 23 of the thick wall portion 20 below in the gravity direction, the annular groove 23 extends from the lower end in the gravity direction toward the outer surface of the chain case 4. It may be a straight through hole such as a drill hole having a downward slope obliquely downward.

  Further, the ring grooves 21 and 24 for accommodating the O-rings 22 and 25 and the annular groove 23 have been described as being provided at the contact portion of the thick portion 20 of the chain case 4 to the cylinder block 1. It may be provided on the surface.

  In the present embodiment, the following effects can be achieved.

  (A) An O-ring 25 as a seal for preventing leakage of cooling water and a seal for preventing leakage of lubricating oil, which are arranged in a portion defining the cooling water passage 10 of the internal combustion engine and the chain chamber 4A which is a lubricating oil chamber. An annular groove 23 is formed as a space portion between the O-ring 22 and one end is opened at the bottom portion of the annular groove 23 as the space portion in the gravity direction, and the other end is opened in the external space of the internal combustion engine. Since the through-hole 26 is formed as a passage, the leaked cooling water or lubricating oil is discharged to the outside without passing through the O-rings 25 and 22 that perform the other sealing function. The leakage of the cooling water or lubricating oil is discharged to the external space through the passage 26, so that the opening of the passage 26 to the external space is confirmed. Only, can check the quality of the sealing function, it can guarantee the quality for the absence of leaks.

  (A) The coolant leakage prevention seal 25 and the lubricating oil leakage prevention seal 22 are disposed on the inner and outer peripheral sides between the members that contact the end faces, and from the inner peripheral side of the mutual contact surfaces. This prevents leakage to the outer peripheral side and leakage from the outer peripheral side to the inner peripheral side, and the space portion is a surface of at least one member facing between the seals 22 and 25. The passage 26 is formed by opening one end below the annular groove 23 in the gravitational direction, so that any one of the seals 22 and 25 is defective and cooling water or lubrication is performed. When oil leaks, it flows in the annular groove 23 toward one end of the passage 26, and even if it leaks in any part of the seals 22, 25, it does not remain in the middle of the annular groove 23. Be sure to go out through the opening facing the external space Because, can check the quality of the sealing function, it can guarantee the quality for the absence of leaks.

  (C) Since the opening to the external space at the other end of the passage 26 is located at a position where it can be seen from the outside of the internal combustion engine, leakage can occur without removing any parts in the assembled state as an engine. It can be confirmed visually whether there is.

  (D) Since at least the lower surface in the gravitational direction of the passage 26 is inclined downward from one end to the other end of the passage 26, leaked cooling water or lubricating oil travels along the lower surface of the downwardly inclined passage 26 to the external space. Since it flows toward the opening facing the surface, it is possible to confirm the quality of the sealing function reliably and to guarantee the quality against the absence of leakage. Further, by forming the passage 27 in a tapered shape whose inner diameter increases toward the outer surface, it can be removed with a molding die when the one member 4 is molded, and processing costs do not occur.

  (E) Since the step 27 is formed in the opening to the outside space at the other end of the passage 26 by a notch in the downward direction of the gravitational force, the liquid leaked at the corner of the step 27 is accumulated due to surface tension. This makes it easier to see the liquid.

(Second Embodiment)
6 to 9 show a second embodiment of the seal structure of the internal combustion engine to which the present invention is applied, and FIGS. 6 and 7 are a transverse sectional view and a longitudinal sectional view showing the first embodiment of the seal structure, FIG. FIG. 9 is a transverse sectional view and a longitudinal sectional view showing a second embodiment of the seal structure of the internal combustion engine. In this embodiment, the structure which a cooling water flow path forms with a hollow tube is added to 1st Embodiment. The same devices as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  In the seal structure of the first embodiment shown in FIGS. 6 and 7, the cooling water passage 10 has a through hole 30 provided in the thick portion 20 provided in the chain case 4 and an inner diameter of the through hole 30 on the cylinder block 1 side. A hollow that is inserted into the expanded diameter portion 31 that has been expanded and the expanded diameter portion 13 in which the inner diameter of the cooling water passage 12 of the cylinder block 1 on the side of the chain case 4 has been increased, with a water-resistant O-ring 32 interposed therebetween. And the tube 33. Further, only the annular ring groove 21 is formed on the contact surface of the thick part 20 of the chain case 4 with the cylinder block 1 so as to accommodate the oil-resistant O-ring 22.

  An annular space 34 defined in the axial direction by an O-ring 32 is formed on the outer peripheral side of the hollow tube 33 between the enlarged diameter portion 31 of the chain case 4 and the enlarged diameter portion 13 of the cylinder block 1. The The annular space 34 is sealed against the cooling water in the cooling water passage 10 by O-rings 32 provided on both sides in the axial direction, and is inserted into the ring groove 21 between the cylinder block 1 and the thick portion 20 of the chain case 4. The O-ring 22 arranged seals the lubricating oil in the chain chamber 4A and has the same function as the annular groove 23 of the first embodiment. The annular space 34 opens to the enlarged diameter portion 31 below in the direction of gravity, passes through the thick portion 20 of the chain case 4, and passes through the through hole 26 that opens to the outer surface of the chain case 4. It communicates with the space. The through hole 26 is formed by an inclined passage having a downward slope with the opening to the enlarged diameter portion 31 as the upper side and the opening to the outer surface of the chain case 4 as the lower side, and is formed by a drill hole or the like. Other configurations are the same as those in the first embodiment.

  In the seal structure of the present embodiment, the cooling water discharged from the water pump 8 is introduced into the cooling water passage 10 via the cooling water pipe 9, and is supplied to the water jacket 11 via the cooling water passage 12 of the cylinder block 1. Supplied. The cooling water passing through the cooling water passage 10 is sealed by an O-ring 32 interposed between the hollow tube 33, the chain case 4, and the enlarged diameter portions 31 and 13 of the cylinder block 1, and enters the annular space 34. Leakage is prevented.

  The chain chamber 4A formed by the chain case 4 and the front ends of the cylinder block 1, the cylinder head 2 and the ladder frame 3 is supplied with lubricating oil to the meshing portions with the sprockets 5 and 7 of the timing chain 6. Is done. Lubricating oil in the chain chamber 4A is sealed by the O-ring 22 inserted into the ring groove 21 of the thick part 20 of the chain case 4, and further leakage to the annular space 34, which is the inner peripheral part, is prevented. .

  Accordingly, in order to prevent leakage of cooling water and lubricating oil of the completed assembled engine, when checking the leakage of a large number of seal portions by applying pressure to each fluid, both O-rings 22 are used. , 32 does not cause leakage of cooling water or lubricating oil in the annular space 34 disposed between the O-rings 22, 32. For this reason, by confirming that no coolant or lubricating oil leaks from the through hole 26 communicating with the annular space 34, it is confirmed that the both seal functions of this portion are complete. It can be confirmed visually from the outside.

  However, when either one of the sealing functions after assembly is incomplete or the O-rings 22 and 32 are not attached (and the O-rings 22 and 32 are deteriorated during regular inspections for long-term use). In this case, leakage of cooling water or lubricating oil to be sealed occurs from the seal portion. The leaked cooling water or lubricating oil flows into the annular space 34 provided between the seals 22 and 32, and the outside of the chain case 4 through the through hole 26 communicating with the annular space 34 in the lower part in the gravity direction. It will leak to the surface. If the stepped portion 27 is provided on the outer surface of the through hole 26, the liquid leaking from the stepped portion 27 is accumulated, and the confirmation work can be further facilitated.

  For this reason, it can confirm that abnormality has generate | occur | produced in any one sealing function by confirming visually that the opening of the through-hole 26 is wet with the liquid. Then, by confirming whether the liquid in the opening of the through hole 26 is cooling water or lubricating oil, it is possible to know which sealing function is defective. Moreover, when both sealing functions are incomplete, both cooling water and lubricating oil will reach the opening of the through-hole 26, and it can be confirmed that both sealing functions are incomplete.

  Further, since the annular space 34 communicating with the outside through the through hole 26 is formed between the O-rings 22 and 32, the leaked cooling water or lubricating oil reaches the O-ring that performs the other sealing function. However, the leaked cooling water or lubricating oil remains in the annular space 34 between the other O-ring and the other O-ring is incomplete or has a long-term dissimilar liquid. It is possible to eliminate the mixing of the lubricating oil and the cooling water caused by passing through the O-ring and leaching out into the other liquid region when exposed to the water.

  In the present embodiment, the thick wall portion 20 of the chain case 4 is only provided with the ring groove 21 and the O-ring 22 for preventing leakage of the lubricating oil. The outer dimensions can be reduced, the volume of the chain chamber 4A can be sufficiently secured, and the degree of freedom of arrangement of the silent chain 6 can be improved.

  In the seal structure of the second embodiment shown in FIGS. 8 and 9, the cooling water passage 10 is a first stage in which the diameter of the cooling water passage 12 provided in the cylinder block 1 is increased by passing through the opening 4 </ b> B provided in the chain case 4. Is formed by an inner hollow tube 35 inserted through an O-ring 32.

  In the chain chamber 4A, an O-ring 41 is interposed between an opening 4B provided in the chain case 4 and a second-stage enlarged diameter portion 14 obtained by enlarging the cooling water passage 12 provided in the cylinder block 1. The outer hollow tube 40 inserted in this manner is defined by the chain case 4 and the front ends of the cylinder block 1, the cylinder head 2, and the ladder frame 3.

  The annular space 36 formed between the inner and outer hollow tubes 35, 40 is on the back side, which is the cylinder block 1 side, and the outer peripheral side is the second-stage expanded portion 14 of the outer hollow tube 40 and the cylinder block 1. Is sealed against the lubricating oil in the chain chamber 4A between the inner hollow tube 35 and the first-stage enlarged diameter portion 13 of the cylinder block 1. The O-ring 32 is arranged to seal the cooling water passage 10 against the cooling water. The annular space 36 communicates with the external space through the gap between the inner and outer hollow tubes 35 and 40 on the outer surface side of the chain case 4. Other configurations are the same as those in the first embodiment.

  Also in the seal structure of the present embodiment, the cooling water discharged from the water pump 8 to the cooling water passage 10 is introduced through the cooling water pipe 9 and is supplied to the water jacket 11 via the cooling water passage 12 of the cylinder block 1. Supplied. The cooling water passing through the cooling water passage 10 is sealed by an O-ring 32 inserted between the inner hollow tube 35 and the first-stage enlarged diameter portion 13 of the cylinder block 1, and leaks into the annular space 36. Is prevented.

  The chain chamber 4A formed by the chain case 4 and the outer hollow tube 40 and the front ends of the cylinder block 1, the cylinder head 2 and the ladder frame 3 is engaged with the sprockets 5 and 7 of the timing chain 6. Is supplied with lubricating oil. Lubricating oil in the chain chamber 4A is sealed by an O-ring 41 disposed between the opening 4B of the chain case 4 and the second-stage enlarged diameter portion 14 of the cylinder block 1 and the outer hollow tube 40, and the inner circumference Leakage into the annular space 36 as a part is prevented.

  Accordingly, in order to prevent leakage of cooling water and lubricating oil of the assembled engine, when checking the leakage of a large number of seal portions by applying pressure to each fluid, each O-ring 32, If the sealing function by 41 is perfect, no leakage of cooling water or lubricating oil occurs in the annular space 36 disposed between the O-rings 32 and 41. For this reason, it is confirmed that each sealing function is complete by confirming that the cooling water and the lubricating oil are not leaking from the annular space 36 opened on the outer surface of the chain case 4. It can be confirmed visually from the outside.

  However, if any of the sealing functions after assembly is incomplete or the O-rings 32 and 41 are not attached (and the O-rings 32 and 41 are deteriorated during regular inspection for long-term use). ), Leakage of cooling water or lubricating oil to be sealed occurs from the seal portion. The leaked cooling water or lubricating oil flows into the annular space 36 provided between the seals 32 and 41 and leaks to the outer surface of the chain case 4 where the annular space 36 is open.

  For this reason, it can confirm that abnormality has generate | occur | produced in any one sealing function by confirming visually that the opening end of the annular space 36 is wet with the liquid. Then, by confirming whether the liquid at the open end of the annular space 36 is cooling water or lubricating oil, it is possible to know which sealing function is defective. When both the sealing functions are incomplete, both the cooling water and the lubricating oil reach the opening end of the annular space 36, and it can be confirmed that both the sealing functions are incomplete.

  Further, since the annular space 36 between the O-rings 32 and 41 communicates with the outside, the leaked cooling water or lubricating oil is discharged outside without accumulating between the O-rings that perform the other sealing function. Therefore, the leaked cooling water or lubricating oil remains in the annular space 36 between the O-rings 32 and 41, and the other O-ring is incomplete or exposed to a different liquid for a long time. Mixing of the lubricating oil and the cooling water caused by passing through the O-rings 32 and 41 and leaching into the other liquid region can be eliminated.

  In the present embodiment, since the annular space 36 is formed by the inner and outer hollow tubes 35 and 40, the outer dimensions thereof can be further reduced, and a sufficient volume of the chain chamber 4A can be ensured. It is possible to further improve the degree of freedom of arrangement of the silent chain 6.

  In the present embodiment, in addition to the effects (a) to (e) in the first embodiment, the following effects can be achieved.

  (F) In the seal structure of the internal combustion engine shown in FIGS. 6 and 7, the lubricating oil leakage prevention seal is disposed between the members 20 and 1 for bringing the end surfaces into contact with each other, and from the outer peripheral side to the inner peripheral side of each contact surface. The cooling water leakage prevention seal is formed on both axial sides of the hollow tube 33 which is disposed by being fitted to the inner peripheral surfaces of the two members 20 and 1 that contact the end surfaces. It is disposed between the outer peripheral portion and the inner peripheral surfaces of both members 20 and 1 that bring the end surfaces into contact with each other, and is formed so as to prevent leakage from the axially opposite sides of the hollow tube 33 to the axially central portion on the outer peripheral side. The space portion 34 is formed as an annular space between the outer periphery of the hollow tube 33 and the inner periphery of the members 20 and 1 that bring the end faces into contact with each other. The passage 26 is formed in the annular space 34. Are formed with one end open at the bottom in the direction of gravity. The radius area to be touched can be reduced, the outer dimension of the thick portion 20 formed toward the other member 1 from the member 4 accommodating the lubricating oil can be reduced, and the layout of the accommodated component, for example, the silent chain 6 can be freely set. The degree can be improved.

  (G) In the seal structure of the internal combustion engine shown in FIGS. 8 and 9, the lubricating oil leakage prevention seal is provided in the holes 4B and 14 provided in the two members 4 and 1 forming the space 4A in which the lubricating oil is accommodated. The outer peripheral side of the outer hollow tube 40 is disposed between the outer peripheral portions of both sides in the axial direction of the outer hollow tube 40 arranged to be fitted to the peripheral surface and the inner peripheral surfaces of the holes 4B and 14 of both members. The cooling water leakage prevention seal is formed by fitting one end into the inner peripheral surface of one of the holes 13 of the two members 4 and 1, It is formed so as to prevent leakage from one end of the inner hollow tube 35 disposed inside the outer hollow tube 40 to the outer peripheral side of the inner hollow tube 35, and the space portion 36 is formed on the inner hollow tube 35. An annular space between the outer periphery and the inner periphery of the outer hollow tube 40 is formed, and the passage 26 is formed in the inner center. Since the end portion of the outer hollow tube 40 located on the outer periphery on the other end side of the tube 35 is formed to open at least in the lower part in the gravitational direction, the outer hollow tube 40 has a space for accommodating lubricating oil. The occupied volume and the outer diameter can be reduced, and the degree of freedom of layout of the parts arranged in the space 4A in which the lubricating oil is accommodated, for example, the silent chain 6 can be further improved.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder head 3 Ladder frame 4 Chain case 5, 7 Sprocket 6 Silent chain 8 Water pump 9 Cooling water piping 10 Cooling water passage 11 Water jacket 20 Thick part 21, 24 Ring groove 22, 25 O-ring 23 Annular groove 26 Through hole 27 Step

Claims (4)

A seal structure including a seal for preventing leakage of cooling water and a seal for preventing leakage of lubricating oil, which are disposed in a portion defining the cooling water passage and the lubricating oil chamber of the internal combustion engine;
A space portion is formed between the seal for preventing leakage of cooling water and the seal for preventing leakage of lubricating oil, and a passage having one end opened at the bottom of the space portion and the other end opened to the external space of the internal combustion engine. To form ,
The seal for preventing leakage of cooling water and the seal for preventing leakage of lubricating oil are arranged on the inner peripheral side and the outer peripheral side between the members that contact the end faces, and from the inner peripheral side of the contact surface to the outer peripheral side. To prevent leakage and leakage from the outer circumference side to the inner circumference side,
The space portion is formed by an annular groove provided on the surface of at least one member facing each other between the seals,
2. The internal combustion engine seal structure according to claim 1, wherein the passage is formed with one end opened below the annular groove in the direction of gravity . 2. The seal structure for an internal combustion engine according to claim 1, wherein the opening to the external space at the other end of the passage is disposed at a position that can be seen from the outside of the internal combustion engine. 3. The internal combustion engine seal structure according to claim 1 , wherein at least a lower surface in a gravitational direction of the passage is formed in a downward slope from one end to the other end . The internal combustion engine according to any one of claims 1 to 3, wherein the opening to the external space at the other end of the passage has a step formed by a notch downward in the gravitational direction. Seal structure.

Images