JP2686644B2 - Main bearing frame structure of engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a multi-cylinder V-type diesel engine and the like.
Regarding the structure of the main bearing frame forming the lower half of the crankcase part, more specifically, a peripheral wall that surrounds the lower half of the crank chamber and a plurality of partition walls that divide the crank chamber into a plurality of parts are integrally formed. TECHNICAL FIELD The present invention relates to an improved technology for a structure for preventing oil leakage from a crank chamber in a main bearing frame that the main bearing frame has, a structure of a lubricating oil-related device that is provided along with such a peripheral wall, and the like.

[Prior Art] Conventionally, the main bearing frame of the above-mentioned type is also called a ladder frame, and is disclosed in Japanese Utility Model No. 60-65417 and Japanese Utility Model No. 62-18683.
No. etc. In such a main bearing frame, since the bearing part of the crankshaft can be supported from below by the large partition which is integral with the peripheral wall parts (the pair of side walls and the pair of partition walls), the support strength of the crankshaft is enhanced. be able to.

And in recent years, in order to make the engine compact,
The crank chamber volume has been set to be relatively small with respect to the total displacement of the engine. For the same purpose, a shallow oil pan has been adopted.

[Problems to be Solved by the Invention] Since the crank chamber volume is relatively reduced in this way, the density of blow-by gas in the crank chamber tends to increase.

Especially in the V-type engine, compared to the in-line type engine,
The volume of the crank chamber is small, the pressure fluctuation range of the crank chamber due to the reciprocating motion of the piston is large, and the density of blow-by gas is high. On the other hand, in the structure adopting the partition wall as described above for supporting the crankshaft, it is desirable to set the partition wall width as large as possible in order to improve the supporting strength as much as possible. It is preferable that the upper edge and the lower edge of the partition wall, except for the recessed portion, are arranged substantially on the same plane as the upper edge and the lower edge of the peripheral wall over the entire length.

However, if the partition wall is set so wide, the crank chamber parts on both sides of the partition wall are completely blocked by the partition wall, and each crank chamber part is completely closed except its lower surface opening (the part communicating with the inside of the oil pan). To be sealed. As a result, when the oil level of the lubricating oil in the oil pan rises and enters the lower surface opening, each crank chamber portion becomes a completely closed space. As a result, the fluctuation range of the internal pressure becomes extremely large, and blow-by gas or lubricating oil is introduced between the cylinder block and the main bearing frame, the mating surface between the main shaft frame and the oil pan, or the oil seal at the crankshaft end. There is a risk of leakage from parts and the like, and in the worst case, a so-called oil-up phenomenon occurs in which lubricating oil rises from the crank chamber to the combustion chamber.

Further, in order to increase the rigidity of the main bearing frame, it is necessary to make the peripheral wall and the like compact, but in order to secure a predetermined capacity of the oil pan, the internal width of the oil pan is set to the above. It may be desirable to make it wider than the perimeter wall. However, if the opening width of the oil pan is made to correspond to the narrow width of the peripheral wall of the main bearing frame and the inner width of the oil pan is to be widened, the shape of the oil pan becomes complicated and its manufacture becomes difficult. It becomes a factor of cost increase.

Further, as described above, the V-shaped engine has a relatively small area of the outer wall of the crank chamber as compared with the in-line engine. Becomes very narrow.
Therefore, it may be difficult to attach the equipment related to the lubricating oil, that is, the lubricating oil pump, the lubricating oil filter, the lubricating oil cooler, the piping and the like to the outer surface of the main bearing frame. In particular, the lubricating oil filter is a component that needs to be replaced regularly, and it is necessary to install it in a place where it can be easily attached and detached, but it is difficult to satisfy such an attachment condition.

As a lubricating oil cooler, a large and heavy shell-and-tube heat exchanger that can be disassembled and cleaned is used in conventional marine engines, but such a large-sized lubricating oil cooler is installed. It is also difficult to do. Of course, when such a lubricating oil cooler is used, there are problems that the overall structure becomes large and the weight increases. In addition, a lightweight and compact multi-plate heat exchanger is used as a lubricating oil cooler in a vehicle engine or the like, but such a cooler cannot be disassembled and cleaned, and therefore cannot be used in a marine engine or the like.

[Means for Solving the Problem] According to the present invention, a peripheral wall formed of a pair of side walls and a pair of end walls surrounding a lower half of a crank chamber, and a lower half of the crank chamber corresponding to a cylinder are defined. A plurality of partition walls that form the crank chamber portion are integrally provided, and each partition wall has an upper edge and an entire lower edge that are substantially on the same plane as the upper edge and the lower edge of the peripheral wall excluding the bearing recess of the crankshaft. Is formed by a plate-shaped portion having a non-perforated structure arranged side by side, and a leg-shaped wall portion that projects outward and downward to form a gas space with the outer surface of the peripheral wall is provided on the outer surface of the peripheral wall, and at the lower end of the leg-shaped wall portion. It is characterized in that the upper end of the oil pan is fixed and a communication hole for connecting each crank chamber portion and the gas space is provided in the peripheral wall.

Further, according to the present invention, a peripheral wall formed of a pair of side walls and a pair of end walls surrounding a lower half portion of the crank chamber, and a plurality of crank chamber portions are formed by partitioning the lower half portion of the crank chamber corresponding to a cylinder. Is integrally formed with a partition wall of the peripheral wall to form a mounting seat of the lubricating oil cooler on the outer surface of the peripheral wall, and the peripheral wall is connected to a lubricating oil passage hole provided therein to form an inlet passage hole opening to the mounting seat. And an outlet passage hole are provided, and a plurality of cooling plates extending along the mounting seat are arranged in a stacked state with a space between each other, and a lubricating oil passage and a cooling water passage that are adjacent to each other with the cooling plate sandwiched are provided between the cooling plates. A seal that seals each lubricating oil passage and each cooling water passage from the outer circumference is provided between two adjacent cooling plates that are formed by a gap, and the cooling plate has lubricating oil passage holes for inlet and outlet and inlet and outlet. The cooling water passage hole and the gap forming the lubricating oil passage Each 2 that face each other across the said gap
A seal for sealing the space between each of the two inlet cooling water passage holes and each of the two outlet cooling water passage holes with respect to the lubricating oil passage is provided, and the gap is formed in the above-described gap forming the cooling water passage. Between each of the two lubricating oil passage holes for the inlet opening across
A seal for sealing the space between the individual outlet lubricating oil passage holes with respect to the cooling water passage is provided, and the inlet and outlet lubricating oil passage holes are connected to the lubricating oil passage holes inside the peripheral wall, And cooling water passage holes for the outlet are respectively connected to the cooling water supply passage and the discharge passage, and means for fixing the cooling plate farthest from the mounting seat to the mounting seat in a state in which the seals are compressed. The feature is that it is provided.

[Embodiment] FIG. 1 is a cross-sectional view showing a cross section of an engine employing an embodiment of the present invention from the side, FIG. 2 is a cross-sectional view of the engine of FIG. 1 viewed from the rear, and FIG. FIG. 4 is a front view of the engine of the example, and FIG. 4 is a plan view of the engine of the embodiment. 1 and 2, the illustrated engine is a V-type 8-cylinder diesel engine. Line A is a crankshaft center line, which is horizontal in the illustrated example. FIG. 2B is a cylinder center plane, which connects the center lines of four cylinders arranged in series. C is an engine center plane including the crankshaft center line A, and the pair of cylinder center planes B are inclined with respect to the engine center plane C in a symmetrical positional relationship.

As shown in Fig. 2, the engine block is a cylinder block
It comprises an assembly of 20, a cylinder head 21, and a main bearing frame 22. The cylinder block 20 includes a crankcase wall 24 surrounding the upper half of the crankcase 23 and a center plane B of each cylinder.
And a pair of cylinder wall portions 25 extending along the axis. Of course, there are four combustion chambers inside each cylinder wall 25.
26 are formed in a line. Each cylinder wall
A cylinder head 21 is fixed to the upper end of the cylinder 25, and a bank 28 (inclined block portion) is formed by each cylinder wall 25 and the cylinder head 21.

An air cooler 30 is disposed in a bank space between two banks 28 arranged in a V shape. The air cooler 30 is provided at the rear portion of the engine, that is, at a position close to the flywheel 32 attached to one end of the crankshaft 31. Air cooler 30 is a supercharger
It is a water-cooled heat exchanger for cooling the air supply from 33,
The overall shape is approximately box-shaped (cubic). The supercharger 33 is arranged at the rear of each cylinder head 21, and the rear curved extension (exhaust communication pipe) of the exhaust manifold 34 is connected to the turbine of the turbocharger 33. As shown in FIG. It is connected to the rear end inlet of the air cooler 30 via 35. An outlet duct 36 that projects forward and curves downward is provided on the front end face of the air cooler 30.

FIG. 5 is a schematic cross-sectional view taken along a line 5-5 in FIG. 4, and FIG.
FIG. 7 is an enlarged partial view of the drawing, FIG. 7 is a schematic plan view of the cylinder block 20 alone, and FIG. 8 is a schematic view taken along the line 8-8 in FIG. As is apparent from FIG. 5, the outlet duct 36 forms a supply air outlet passage opening downward, and its tip end is connected to the distribution chamber wall portion 40. As is clear from FIGS. 5 and 7, the distribution chamber wall portion 40 is formed by bulging the portion of the cylinder block 20 in the vicinity of the outlet duct 36 (FIG. 5) upward. 3 open openings 41, 42
Are provided at intervals in the engine width direction.

The outlet duct 36 is connected to the central opening 41 as described later, and an air supply outlet passage inside the outlet duct 36 communicates with the distribution chamber 43 inside the distribution chamber wall 40 via the opening 41.
The two left and right openings 42 are open at the inclined upper end surface of the distribution chamber wall 40. This inclined upper end surface is substantially coplanar with the inclined upper end surface of the cylinder block 20 main body.
The inlet wall portion 46 of the air supply manifold 45 provided on the inner side surface (V bank space side) is seated on the inclined upper end surface of the distribution chamber wall portion 40, and the distribution chamber 43 is supplied through the opening 42. It communicates with the air manifold 45 and an internal passage (air supply passage). According to this structure, the low-temperature air supplied from the air cooler 30 to the distribution chamber 43 through the opening 41 is distributed right and left in the distribution chamber 43, and is supplied to the air supply manifolds 45 of the two cylinder heads 21 through the opening 42. Flows into

Although the air supply manifold 45 is formed integrally with the cylinder head 21 in the illustrated structure, it may be formed separately.

As shown in FIG. 6, short pipes 50 and 51 are used in the connection structure at the openings 41 and 42. The distribution chamber wall portion 40 includes cylindrical portions surrounding the openings 41 and 42, respectively, and an annular step portion 52 is formed in the middle of the inner peripheral surface of the cylindrical portions. Pipe 5
Reference numerals 0 and 51 each have a lower half portion fitted to the inner periphery of the cylindrical portion via an O-ring 53, and a lower end surface in contact with or in proximity to the annular step portion 52. The upper half portions of the pipes 50 and 51 are fitted to the tubular inner peripheral surfaces of the outlet duct 36 and the inlet wall portion 46 of the air supply manifold 45 via the O-rings 54, and the upper end surfaces thereof are the above-mentioned inner portions. It is in contact with or close to the annular step portion 55 provided on the peripheral surface.

In the above-described structure, the distribution chamber wall 40 is
Instead of this structure, the distribution chamber wall 40 can be formed separately from the cylinder block 20, as shown in FIG.

5 and 7, a wall portion 56 forming the bottom surface of the distribution chamber 43 extends horizontally, and both ends thereof are continuous with a vertical intermediate portion of the cylinder wall portion 25. The wall portion 56 is provided over the entire length of the cylinder block 20. As shown in FIG. 5, between the two cylinder walls 25, two cooling water passages 60, 61 are provided below the wall 56 so as to be separated from each other by a vertical partition wall 62. The upper end of the partition wall 62 is continuous with the middle part in the width direction of the wall 56, and the lower end is continuous with the upper end of the crankcase wall 24. The cooling water passages 60 and 61 have rear ends serving as inlets. As shown in FIG. 1, cooling water flows into the inlets through the thermostat 64 alternatively.

The thermostat 64 is mounted using the rear of the wall 56 (the bottom wall of the V bank space). The chamber 65 in which the thermostat 64 is installed is formed in the cylinder block 20 above the rear part of the cooling water passages 60 and 61, and the cooling water that has cooled the cylinder block 20, the cylinder head 21, and the exhaust manifold 34 is provided in the chamber 65. It is designed to flow in. The thermostat 64 connects the chamber 65 to the cooling water passage 60 when the cooling water temperature is low, and connects the chamber 65 to the cooling water passage 61 when the cooling water temperature is high. The thermostat 64 and a case covering the thermostat 64 from above are located below the air cooler 30.
It is fixed to the cylinder block 20 from above.

As shown in FIGS. 7 and 8, the outlet side ends of the cooling water passages 60 and 61 are located near the front end of the cylinder block 20. The outlet end of the cooling water passage 60 is
20 communicates with a pump chamber 71 through an inlet hole 70 provided in the front end face. Cylinder block around pump chamber 71
A case of a cooling water pump 72 (FIG. 7) is fixed to the front end face of the pump 20. This pump case and cylinder block 20
The pump chamber 71 is formed by a recess provided in the front end surface of the pump chamber 71.

The pump chamber 71 has an inlet hole 70 in addition to the cooling water passage 60.
Is also connected through the inlet hole 73. The entrance hole 73 is the entrance hole 70
And extends upward in the cylinder inclination direction, and opens to the end surface of the adjacent cylinder block. Outlet passage 74 of pump chamber 71
(FIG. 8) is formed inside the cylinder block 20, and the cooling water discharged from the outlet passage 74 is used for cooling water jacket 75 inside the cylinder block 20, the cylinder head 21, and the exhaust manifold 34 (FIG. 1). After that, the flow returns to the thermostat chamber 65.

The outlet side end of the cooling water passage 61 is connected to a hose 81 via an outlet hole 80. The outlet hole 80 extends obliquely upward from the passage 61 and opens at the upper end surface of the cylinder block opposite to the inlet hole 73. The outlet of the hose 81 is the expansion tank 82
And a cooling water cooler 83. The cooling water cooler 83 is for cooling the cooling water with seawater, and has an outlet connected to the inlet hole 73 via a hose 84.

According to the above configuration, when the temperature of the cooling water after cooling the respective parts of the engine is relatively low, the thermostat 64 causes the cooling water to flow into the cooling water passage 60. Therefore, the cooling water is not sent to the cooling water cooler 83, but flows into the pump chamber 71 from the cooling water passage 60, where it is pressurized and sent to the jacket 75. When the cooling water temperature is high, the thermostat 64 sends the cooling water to the cooling water passage 61, and the cooling water is sent from there to the expansion tank 82 and the cooling water cooler 83 via the hose 81, and the cooling water cooler 83 After being cooled, it is sent from the hose 84 to the pump chamber 71 via the inlet holes 73 and 70.

As described above, the cooling water passages 60 and 61 are formed at the upper center of the cylinder block 20. To facilitate the casting operation, the following structure may be employed.
That is, as shown in FIG. 7, a relatively large slit-shaped sanding opening 85 is provided at the front of the wall portion 56, and the opening 85 is closed by a lid 86 after the casting operation.

At the front end of the crankshaft 31 below the cooling water cooler 83, various auxiliary devices and a timing belt mechanism for driving the camshaft 101 are provided. The timing belt mechanism includes two timing belts 102 and 103, two drive pulleys 104 and 105 (FIG. 1) for driving them, and a plurality of pulleys to be described later driven by them. .

The driving pulley 104 is fixed to the crankshaft 31 at a position adjacent to the front end surface of the engine block, and the driving pulley 105 is fixed to the crankshaft 31 at the front side of the driving pulley 104. Therefore, the timing belt 102
Is located closer to the engine block than the timing belt 103 is.

As is apparent from FIG. 1, the illustrated engine is of an overhead valve type. Therefore, the intake / exhaust valve driving camshaft 101 extends in the vicinity of the upper end of the cylinder head 21 substantially parallel to the crankshaft center line A over the entire length of the engine. Extends to.

In FIG. 3, a timing belt 102 close to the engine block is a cam pulley provided at the front end of both cam shafts 101.
The cooling water pump 72 is further bridged between an input pulley 111 of the cooling water pump 72 and an idle pulley 112 provided at the center of the front end face of the engine block.

The other timing belt 103 includes an input pulley 116 of a fuel injection pump 115 (FIG. 1) located directly above the crankshaft 31 and a main bearing frame 22 (a lower half wall of the crank chamber).
Of the lubricating oil pump 117 located on the left side of the front end face of the motor.

Further, the seawater pump 121 of the generator 120 is arranged on the left side of the crankshaft 31, and their input pulleys are
As shown in FIG. 1, it is connected to a pulley 123 on the crankshaft 31 by a V-belt 122. The pulley 123 is fixed to the front end of the crankshaft 31 in front of the drive pulley 105.

A belt cover 130 that covers the above-described timing belt mechanism is provided between the V-belt 122 and the pulley 123 and the engine block. The belt cover 130 covers the front and periphery of the timing belt mechanism, and its edge is fixed to the engine block. In FIG. 3, 130a indicates a central portion of the upper edge of the belt cover 130, 130b indicates an upper edge side portion, 130c indicates a side edge, and 130d indicates a lower edge. As is apparent from this figure, the outer periphery of the belt cover 130 has a shape that relatively accurately follows the installation range of the timing belts and the pulleys driven by the timing belts.

In FIG. 1, the pulley 11 for the fuel injection pump described above is used.
6 is a gear mechanism 131 with respect to the input shaft of the fuel injection pump 115.
Are connected via In the structure shown in the drawing, two fuel injection pumps 115 are used and are installed at the front of the V bank space, as is apparent from FIGS. The two fuel injection pumps 115 are juxtaposed in the engine width direction. As shown in FIG. 1, an input gear 132 attached to the front end of each of the input shafts is connected to an intermediate gear 133 common to both. The gear 133 is fixed to a rear end of a shaft 134 parallel to the crankshaft center line A. The shaft 134 has an intermediate portion supported by a gear case or a bracket portion on the engine block via a bearing, and the pulley 116 is fixed to a front end thereof.

In the above structure, the camshaft 101 and various accessories are driven by one end (front end) of the crankshaft 31. Therefore, among the bearing bushes 135 and 136 provided at a plurality of positions on the crankshaft 31, the frontmost bearing bush 135 is provided. Is subjected to a relatively large load. In view of this point, in the illustrated embodiment, the length of the bearing bush 135 at the front end portion is set to be longer than the length of the other bearing bushes 136, so that the surface pressure of each bearing bush 135, 136 is increased. Are equalized.

Next, the main bearing frame 22 and the oil pan 150 provided thereunder will be described. FIG. 10 is a schematic bottom view of the main bearing frame 22 of FIG. FIG. 11 is the same as FIG.
FIG. 12 is a partial sectional view taken along line 12-12 of FIG. As is clear from FIG. 10, the main bearing frame 22
A pair of side walls 151 extending substantially parallel to the engine center plane C
And a pair of (front and rear) end walls 152, 153 extending substantially perpendicular to the crankshaft center line A, and 3 extending parallel to the end walls.
Partition walls 154 and the side walls 151 and the end walls 15.
2, 153 form the peripheral wall of the main bearing frame 22. 3
Each of the partition walls 154 has both ends continuous with the side wall 151, and is separated from each other in the longitudinal direction of the crankshaft.

These partition walls 154 divide the crankcase 23 (more precisely, the lower half of the crankcase) into four crankcase portions 155. As shown in FIG. 12, each partition 154 has its entire upper surface flush with the upper end surfaces of the side walls 151 and the end walls 152, 153, except for a semicircular recess for supporting the bearing bush 136 for the crankshaft (FIG. 1). The lower end face is also flush with the lower end faces of the side walls 151 and the end walls 152 and 153. That is, the main bearing frame
The entire upper end surface of 22 has a single flat surface except for the above-mentioned bearing recess, and the entire lower end surface also forms a single flat surface.

In this way, since the partition wall 154 has a size sufficient to completely close each rank chamber portion 155 from the front or the rear,
Its strength is high, so the bulkhead 15 with respect to the crankshaft 31
4 (therefore, the main bearing frame 22) has high support strength and rigidity.

By adopting a structure in which each crank chamber part 155 is closed by the partition 154 in this manner, if the oil level in the oil pan 150 rises above the lower end of the partition 154 due to engine shake or the like, a pressure relief structure described later will be used. If you do not provide
Each crank chamber portion 155 is a closed space. Then, since the pressure in the crank chamber portion 155 periodically increases due to the reciprocating motion of the corresponding piston, etc., such a closed space causes a remarkable pressure increase, and the crank chamber portion 155
Lubricating oil droplets inside may leak to the outside.

In order to prevent such a situation, the above-mentioned pressure relief structure is provided, and the structure includes a leg-like wall portion 160, a communication hole 161 and a gas space 162. Leg-like wall 160 is side wall 151
And are integrally provided on the outer surfaces of the end walls 152 and 153.
As shown in the figure, a gas space 162 that extends obliquely downward from the upper part thereof and opens downward is formed between the corresponding wall (side wall 151, end walls 152 and 153). The leg-like wall 160 is provided over the entire circumference of the main bearing frame 22, so that the gas space 162 forms a substantially rectangular groove-like space extending over the entire circumference of the main bearing frame 22. The communication hole 161 is provided to allow the gas space 162 to communicate with each of the crank chamber portions 155, and is provided at one location on one of the side walls 151 for each of the crank chamber portions 155. With this structure, it is possible to prevent only the pressure in the specific crank chamber portion 155 from abnormally increasing.

Blow-by gas flows into each crank chamber portion 155. When this gas mixes with the lubricating oil in the oil pan 150, the lubricating oil deteriorates. The following structure is adopted to prevent such a situation. That is, as shown in FIG. 12, a protruding portion 163 that protrudes upward is provided at one location of the leg-like wall portion 160, and a space 164 that communicates with the gas space 162 is provided inside the protruding portion 163. Is formed. This space 164 has a perforated plate 165 (10th
As shown in the figure, the breather 167 is formed by accommodating a wire mesh member 166 therein. The space 164 is connected to an external blow-by gas discharge pipe 169 through a connection poi 168 attached to a hole on the side surface of the projecting portion 163. The outlet of the discharge pipe 169 is open to the atmosphere, for example.

The oil pan 150 has its upper end peripheral portion bolted to the lower end of the leg-like wall portion 160. The lubricating oil in the oil pan 150 is supplied from the suction pipe 170 (FIG. 1) to the lubricating oil pump 117 (FIG. 10) via the following route.

In FIG. 10, an inlet hole 171 to which the outlet of the suction pipe 170 (FIG. 1) connects is open on the lower surface of the front part of the side of the main bearing frame 22. This inlet hole 171 is used for the main bearing frame 2
2 extends to the front end face of one of its sides. First
As shown in FIGS. 0 and 11, the inlet hole 171 opens at the front end surface (the mounting seat 172) of the main bearing frame 22 to form a suction port of the lubricating oil pump 117. A pump casing of the lubricating oil pump 117 is fixed to the mounting seat 172. Inside the inlet hole 171 (on the side of the crankshaft center plane C), one end of the communication hole 173 opens in the mounting seat 172 to form a pump discharge port.

The communication hole 173 extends from the side on the lubricating oil pump 117 side to the other side through the inside of the front end wall portion (an aggregate of the end wall 152 and the leg-like wall portion 160) of the main bearing frame 22 and has a front end portion. Surface (mounting seat
174).

A lubricating oil filter 175 is mounted on the mounting seat 174. The outlet of the communication hole 173 is connected to the inlet of a filter installation space (filtration processing space) inside the lubricating oil filter 175. The outlet of the communication hole 173, that is, the inlet of the lubricating oil filter 175 is annular as shown in FIG. 11, and the outlet of the filter 175 (the inlet of the passage hole 176) is provided on the center side thereof.

According to this structure, the lubricating oil pressurized by the pump 117 is supplied to the lubricating oil filter 175 through the communication hole 173, but in order to prevent excessive hydraulic pressure from being supplied to the lubricating oil filter 175, A safety valve 180 is provided in the middle of the communication hole 173 (near the lubricating oil pump 117 in the embodiment). Tenth
As shown in FIG. 13, which is a schematic sectional view taken along the line 13-13 in FIG. 13, the safety valve 180 is configured as follows. That is, a vertical hole communicating with the communication hole 173 is provided on the lower surface of the main bearing frame 22,
A cylindrical case 181 is fixed to the hole from below. A ball 182 serving as a valve body, a compression coil spring 183 for urging the ball 182 from below, and a case
A spring support 184 fixed to the lower end of the 181 and supporting the spring 183 from below is attached.

In this structure, when the hydraulic pressure in the communication hole 173 exceeds a predetermined value, the ball 182 is pushed down by the hydraulic pressure, and a gap is formed between the case 181 and the ball 182. The lubricating oil in the communication hole 173 is released into the oil pan 150 through the gap.

As shown in FIG. 10, the passage hole 176 extends inside the side wall portion (an aggregate of the side wall 151 and the leg-like wall portion 160 continuous thereto) of the main bearing frame 22 on the filter 175 side to the vicinity of the rear end portion. .

In the passage hole 176, a differential pressure valve 190, a pressure regulator 191 and a lubricating oil cooler 192 are provided side by side. The side wall has a passage 176.
There are provided passage holes 193 and 194 extending from the front side to the outer side surface. The differential pressure valve 190 is located at a longitudinally intermediate portion of the passage hole 176, and the passage holes 193 and 194 are located upstream and downstream of the differential pressure valve 190, respectively. On the outer side surface of the side wall portion, around the passage holes 193 and 194 and between both,
A mounting seat 195 (flat surface) for mounting the lubricating oil cooler 192 is provided, and inside the lubricating oil cooler 192 mounted on the mounting seat 195, passage holes 193 and 194 are directly connected.

The differential pressure valve 190 is connected to the inlet passage hole 193 of the lubricating oil cooler 192.
And for eliminating the pressure difference between the two when the hydraulic pressure difference between the outlet passage hole 194 and the outlet passage hole 194 exceeds a predetermined value,
This prevents an excessive oil pressure from being applied to the lubricating oil cooler 192.

In FIG. 14, which is a schematic cross-sectional view taken along the line 14-14 in FIG. 10, the differential pressure valve 190 is provided with a cylindrical piston 200 having a closed upper end, a bolt-shaped case 201 disposed therebelow, and a piston 201 disposed therebetween. And a compression coil spring 202 which is attached to the inner periphery of a cylindrical boss 203 provided on the side wall. In the illustrated valve closed state, the piston 200
Is seated on an annular valve seat 204 (step) provided on the inner periphery of the boss 203. The upstream portion of the passage hole 176 extends substantially horizontally from the passage hole 193 to the differential pressure regulating valve 190, and the downstream end is curved downward and faces the upper end surface of the piston 200.
The downstream portion of the passage hole 176 is the piston 200 in the closed position.
The opening is formed at a position facing the outer peripheral surface of the upper portion, and extends obliquely upward from that position to reach the passage hole 194. Further, the boss 203 is provided with a back pressure relief passage 205 that connects the installation space of the spring 202 and a downstream portion of the passage hole 176.

According to this structure, when the oil pressure in the passage hole 193 is abnormally high, the piston 200 is pushed downward by the oil pressure, the differential pressure valve 190 is opened, and an excessive oil pressure is applied to the lubricating oil cooler 192 (FIG. 10). It can be prevented from joining. Further, as is apparent from the above, the portion of the normal hole 176 between the inlet passage hole 193 and the outlet passage hole 194 forms a bypass passage opened and closed by the differential pressure valve 190.

As shown in FIG. 15, which is a schematic cross-sectional view taken along a line 15-15 in FIG. 10, the pressure regulating device 191 is constituted by a valve basically similar to the differential pressure valve 190 in FIG. Case 2
11 and a compression coil spring 212 disposed between them are incorporated in an iron cylindrical insert 213.
The insert 213 is fixed in a cylindrical boss 214 provided on the main bearing frame 22. This boss 214 is used for passage hole 17
6 extends from the vicinity of 6 to the outside in the engine width direction.
The head 11 is exposed on the outer side surface of the main bearing frame 22.

The outer periphery of the tip of the piston 210 is adapted to be seated on the annular valve seat 215 on the inner periphery of the end of the insert 213, and the passage hole 176 faces the distal end surface of the piston 210 via the opening at the end of the insert 213. doing. Below the piston 210, the insert 213 and the boss 214 are provided with a discharge hole 216 and a back pressure relief passage 217. The discharge hole 216 extends downward from the lower side of the outer peripheral surface of the piston 210 in the illustrated closed state and communicates with the internal space of the oil pan 150. The back pressure relief passage 217 extends obliquely downward from the installation space of the spring 212 and communicates with the internal space of the oil pan 150.

Further, as is apparent from FIG.
A short oil passage 219 extending from the passage hole 176 to the upper end surface is provided in the vicinity of the pressure adjusting device 191, and the communication hole 176 is connected to the oil gallery in the cylinder block 20 via the oil passage 219. There is.

According to the above structure, when the oil pressure in the passage hole 176 becomes higher than a predetermined value, the piston 210 is pushed by the oil pressure to open the discharge hole 216, and the surplus lubricating oil is discharged from the discharge hole 216 into the oil pan 150. You. Therefore, the hydraulic pressure in the passage hole 176,
That is, the hydraulic pressure supplied to the oil gallery is always kept at an appropriate value.

16 is a view taken in the direction of arrows 16-16 in FIG. 10, and FIGS. 17 and 18 are schematic sectional views taken along lines 17-17 and 18-18 in FIG. 16, respectively. In these figures, the lubricating oil cooler 192 is
Cooling plates 230 parallel to
And a plate 231 opposed to the plate 231. The cooling plate 230
Seals 232, 233, and 234 are interposed between two adjacent cooling plates 230 and between the mounting seat 195 and the adjacent cooling plate 230. . These seals, in addition to their original sealing function, also function as spacers for maintaining an appropriate spacing between adjacent cooling plates 230.

Each cooling plate 23 except for the cooling plate 231 which is in contact with the plate 231.
On both sides of 0, a lubricating oil passage 235 and a cooling water passage 236 are formed by the gap. That is, the lubricating oil passage 235 and the cooling water passage 236 are formed alternately. The seal 232 extends in a rectangular shape along the outer periphery of each cooling plate 230. Inside the seal 232, two passage holes 237 and two passage holes 238 are provided at four corners of each cooling plate 230 so as to be arranged diagonally.

As shown in FIG. 17, in each cooling plate 230, two passage holes 2
One of the 37 is arranged on the same straight line as the inlet passage hole 193, and the other passage hole 237 is arranged on the same straight line as the outlet passage hole 194. The seal 233 is disposed only in the gap forming the cooling water passage 236, and shields the space between two adjacent passage holes 237 from the cooling water passage 236.

As shown in FIG. 18, the other seal 234 is disposed in a gap forming the lubricating oil passage 235, and two adjacent passage holes are provided.
The passage hole 238 is disposed around the 238 and shields the passage hole 238 from the lubricating oil passage 235. Therefore, a cooling water inlet passage and an outlet passage communicating with each cooling water passage 236 are formed by the space surrounded by the seal 234 and the passage hole 238. These cooling water passages are respectively connected to an inlet hose 84 and an outlet hose 87 attached to the plate 231.

The plate 231 is a mounting seat for the above assembly of the cooling plate 230.
195 is pressed from the opposite side, and the four corners are fixed to the mounting seat 195 by long bolts 242. A fixing means such as a bolt is not attached to each cooling plate 230, and the cooling plate 230 and the seal 2 are fixed by the bolt 242 and the plate 231.
32, 233, and 234 are maintained in the assembled state as shown.

As shown in FIG. 19, a plate 243 may be provided between the mounting seat 195 and the cooling plate 230, a bolt 242 may be fixed to the plate 243, and the plate 243 may be mounted to the mounting seat 195 with another bolt 244.

Also, as shown in FIG. 20, a lubricating oil passage hole 194 on the outlet side is provided outside the installation range of the lubricating oil cooler 192, and a lubricating oil outlet passage inside the lubricating oil cooler 192 is formed from the outer surface of the plate 231 through the passage hole. 1
It can also be connected by an external connection poi 245 extending to 94.

[Effect of the invention] According to the invention of claim 1, the gas space 162 is formed around the main bearing frame 22, and the gas space 162 and the crank chamber portion 155 are connected by the communication hole 161. Even if the oil level in the oil pan 150 rises, it is possible to prevent the crank chamber portion 155 from being completely sealed. Therefore, it is possible to reliably prevent the abnormal pressure rise in each crank chamber portion 155 and the oil leakage due to the abnormal pressure rise.

In other words, since the crank chamber portion 155 is completely sealed in this way by the communication hole 161 provided in the peripheral wall (side wall 151 in the embodiment), the partition wall 154 itself has a cutout for the communication hole. It is not necessary to provide a passage hole, so that the strength thereof can be increased and the rigidity of the entire main bearing frame 22 can be increased.

According to the structure of claim 2, the gas space 162
Is open to the external space through the breather 167, so that the harmful blow-by gas inside the crank chamber portion 155 can be discharged reliably and promptly. Moreover, since the breather 167 is provided using the gas space 162 outside the side wall 151, it is possible to reliably prevent the lubricating oil splash in the crank chamber portion 155 from directly splashing to the breather 167 on the side wall 151.

According to the invention of claim 3, a lubricating oil cooler is provided.
Since the 192 can be basically constructed by simply fixing the plurality of cooling plates 230 to the outer surface of the main bearing frame 22 in a laminated state,
The structure is simple and compact, and the plate 231 and the bolt 242 (the cooling plate 2 farthest from the mounting seat 195) are used.
The lubricating oil cooler 192 can be disassembled and cleaned simply by removing (fixing means 30) from the mounting seat 195. Also, since the lubricating oil cooler 192 is so compact,
Main bearing frame for V-engines with a relatively small outer surface area 22
It can be easily attached to the outer surface of.

According to the structure of claim 4, the lubricating oil cooler
It is possible to reliably prevent abnormal hydraulic pressure from being applied to the 192.

Further, in the structure of the embodiment, the pressure regulating device 192 is the main bearing frame 2
It is exposed on the outer surface (side surface) of 2 and has a safety valve 180 and a differential pressure valve.
Since 190 is also provided on the lower surface of the main bearing frame 22 (the surface exposed when the oil pan 150 is removed), maintenance and inspection of those devices is easy.

[Brief description of the drawings]

1 is a cross-sectional view showing a cross section of an engine employing an embodiment of the present invention from the side, FIG. 2 is a cross-sectional view of the engine of FIG. 1 as viewed from the rear, and FIG. FIG. 4 is a plan view of the engine of the embodiment, FIG.
6 is an enlarged partial view of FIG. 5, FIG. 7 is a schematic plan view of a single cylinder block, FIG. 8 is a schematic view taken along arrows 8-8 in FIG. 7, FIG. Is a schematic cross-sectional view of another embodiment, FIG. 10 is a schematic bottom view of the main bearing frame, FIG. 11 is a schematic view taken along the line 11-11 of FIG. 10, FIG. 12, FIG. 13, FIG. 14, FIG.
Fig. 15 shows 12-12, 13-13, 14-14, and Fig. 10 respectively.
FIG. 15 is a schematic cross-sectional view taken along line 15-15, FIG.
17 and 18 are schematic sectional views taken along lines 17-17 and 18-18 of FIG. 16, FIG. 19 is a schematic partial sectional view of another embodiment, and FIG. 20 is a schematic view of still another embodiment. 20 …… Cylinder block, 23 …… Crack chamber, 117 ……
Lubricating oil pump, 150 …… Oil pan, 151 …… Sidewall, 15
2, 153 ... End wall, 154 ... Partition wall, 155 ... Crank chamber part, 160 ... Leg wall part, 161 ... Gas space communication hole, 162 ...
… Gas space, 167 …… Breazer, 170 …… Lubricant oil suction pipe, 171 …… Lubricant oil inlet hole, 173 …… Lubricant oil passage hole, 17
5 ... Lubricant oil filter, 176 ... Lubricant oil passage hole, 190 ...
… Differential pressure valve, 230 …… Cooling plate, 232,233,234 …… Seal,
235 ... Lubricating oil passage, 236 ... Cooling water passage, 237 ... Lubricating oil passage hole, 238 ... Cooling water passage hole, 244 ... Bolt (fixing means)

Claims (4)

(57) [Claims] 1. A peripheral wall composed of a pair of side walls and a pair of end walls surrounding a lower half of the crank chamber, and a plurality of crank walls defining the lower half of the crank chamber corresponding to cylinders. A plate-shaped member having a non-hole structure in which the partition walls are integrally provided, and each partition wall has an entire upper edge and an entire lower edge excluding a recess for a bearing of a crankshaft that are substantially flush with the upper and lower edges of the peripheral wall. A leg-shaped wall portion that forms a gas space between the outer surface of the peripheral wall and the outer surface of the peripheral wall, and forms a gas space with the outer surface of the peripheral wall, and fixes the upper end of the oil pan to the lower end of the leg-shaped wall portion. A main bearing frame structure for an engine, characterized in that a communication hole that connects each crank chamber portion and a gas space is provided in the peripheral wall. 2. The main bearing frame structure for an engine according to claim 1, wherein a breather device for discharging blow-by gas in the crank chamber to the outside is provided in the gas space. 3. A peripheral wall consisting of a pair of side walls and a pair of end walls that surround the lower half of the crank chamber, and a plurality of peripheral walls that define the lower half of the crank chamber corresponding to cylinders to form a crank chamber portion. A partition wall is integrally provided, and a mounting seat for the lubricating oil cooler is formed on the outer surface of the peripheral wall, and an inlet passage hole is formed in the peripheral wall, which is connected to a lubricating oil passage hole provided therein and opens in the mounting seat. An outlet passage hole is provided, and a plurality of cooling plates extending along the mounting seat are arranged in a stacked state with a space between each other, and a lubricating oil passage and a cooling water passage that are adjacent to each other with the cooling plate sandwiched are provided between the cooling plates. And a seal for sealing each lubricating oil passage and each cooling water passage from the outer periphery is provided between two adjacent cooling plates, and the cooling plate is provided with an inlet and an outlet lubricating oil passage hole and an inlet and an outlet. A cooling water passage hole is provided, and in the gap that forms the lubricating oil passage, It provided a seal for sealing the space between the two between the inlet for the cooling water passage holes and each two outlets for the cooling water passage holes which face each other across a gap with respect to the lubricating oil passage,
A space between each of the two inlet lubricating oil passage holes and each of the two outlet lubricating oil passage holes, which are opened with the gap therebetween, is provided in the gap forming the cooling water passage with respect to the cooling water passage. A sealing oil seal is provided to connect the inlet and outlet lubricating oil passage holes to the lubricating oil passage holes inside the peripheral wall, and the inlet and outlet cooling water passage holes are respectively connected to the cooling water supply passage and the discharge passage. A lubricating oil cooling device for an engine, comprising means for fixing a cooling plate, which is most distant from the mounting seat, to the mounting seat, with the seals being compressed. 4. A bypass passage for connecting the inlet passage hole and the outlet passage hole for a lubricating oil cooler in the peripheral wall is provided inside the peripheral wall, and the inlet passage hole and the outlet passage hole are provided in the bypass passage. The engine lubricating oil cooling device according to claim 3, further comprising a differential pressure valve that opens when a pressure difference between the differential pressure and the pressure exceeds a predetermined value, and a mounting seat of the differential pressure valve is provided on the peripheral wall.