JP2005344660A - Turbocharger lubrication structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating structure for a turbocharger that can avoid problems such as oil leakage, can reduce the number of parts and simplify the configuration, and can be expected to reduce manufacturing costs.
SOLUTION: A turbocharger 10 is arranged at a lower part of an engine main body 21, and an oil collecting tank 31 to which oil OL discharged from the turbocharger 10 is supplied and oil OL in the oil collecting tank 31 are supplied. An oil recirculation pump 38 for feeding to the oil pan 25 is provided, the upper peripheral edge 33a of the oil collecting tank 31 is coupled to the bottom 26 of the oil pan 25, and the base end 34a of the pressure adjusting pipe 34 is connected to the oil pan 25 and the oil The oil tank 25 is coupled to the bottom 26 of the oil pan 25 that defines the inside of the collection tank 31, communicates with the oil collection tank 31, passes through the oil pan 25, and opens into the crankcase 22.
[Selection] Figure 1

Description

  The present invention relates to a turbocharger for a vehicle engine, and more particularly to a lubrication structure for a turbocharger disposed at a lower portion of an engine body.

  For example, as shown in a cross-sectional view in FIG. 4, a turbocharger disposed in a vehicle engine has a turbine chamber 11 and a compressor chamber 12 integrally coupled via a center housing 13, and a turbine wheel in the turbine chamber 11. 14 and a compressor wheel 15 in the compressor chamber 12 are connected by a turbine shaft 17 rotatably supported by a compressor wheel side bearing 16 a and a turbine wheel side bearing 16 b provided in the center housing 13. The turbocharger 10 rotates the compressor wheel 15 via the turbine shaft 17 by rotating the turbine wheel 14 with the exhaust gas from the exhaust manifold, and the intake air compressed by the rotating compressor wheel 15 is supplied to the intake manifold. It is sent and supercharged.

  Since the turbine shaft 17 of the turbocharger 10 rotates at a high speed and becomes high temperature, it is necessary to sufficiently lubricate and cool the turbine wheel side bearing 16a and the compressor wheel side bearing 16b.

  For this reason, the oil OL is supplied from an oil inlet 18a that opens to the top inside the center housing 13, and is supplied to the turbine wheel side bearing 16a and the compressor wheel side bearing 16b through an oil supply passage 19 provided in the center housing 13. The oil OL that has lubricated and cooled the turbine wheel side bearing 16 a and the compressor wheel side bearing 16 b is configured to be discharged from an oil outlet 18 b that opens at the lower portion of the center housing 13 and collected.

  An oil seal portion for preventing oil oil OL from leaking from between the center housing 13 and the turbine shaft 17 to the boundary portion between the center housing 13 and the turbine chamber 11 and the boundary portion between the center housing 13 and the compressor chamber 12. 20 is arranged. As shown in FIG. 5, the oil seal portion 20 disposed between the center housing 13 and the turbine shaft 17 is ring-shaped and prevents excessive pressure contact force from acting on the turbine shaft 17 that rotates at a high speed. The gap 20a is formed in a part thereof and is divided.

  However, since the pressure in the center housing 13 is higher than the pressure in the compressor chamber 12 in a low engine speed range, for example, 600 to 800 rpm, the oil OL supplied into the center housing 13 The supercharging performance is reduced by the oil OL leaking into the turbine chamber 11 and the compressor chamber 12 through the gap 20a and leaking into the turbine chamber 11 and the compressor chamber 12.

  As a countermeasure against this, as schematically shown in FIG. 6, the oil OL in the oil pan 100 is sent to each lubrication portion 102 of the engine by the oil pump 101, and a part of the oil OL passes through the check valve 103 and the turbocharger 10. Oil is sent to the oil inlet 18a. On the other hand, between the oil outlet 18 b of the turbocharger 10 and the oil pan 100, two systems of oil circuits, a first oil conduit 104 and a second oil conduit 106 provided with an oil pump 105, are arranged in parallel. . And normally, the oil OL from the oil outlet 18 b is discharged to the oil pan 100 through the first oil conduit 104. On the other hand, in the low engine speed range, the engine speed is detected by the engine speed sensor 107, and the electromagnetic control valve 110 is switched to the second oil pipe 106 side by the changeover switch 109 according to the signal from the electronic control unit 108. The oil pump 105 is operated to suck the oil OL in the turbocharger 10 and discharge it to the oil pan 100, thereby preventing the oil OL in the center housing 13 from leaking into the turbine chamber 11 and the compressor chamber 12. An oil leakage prevention device for a turbocharger is known (for example, see Patent Document 1).

  On the other hand, a turbocharger may be provided at the lower part of the engine body in order to lower the center of gravity of the vehicle body and improve running stability (for example, Patent Document 2).

  This type of turbocharger lubrication structure will be described with reference to FIG. 7, taking as an example a case where the turbocharger lubrication structure is mounted in the lower part of the engine body of a horizontally opposed engine. FIG. 7 is a front view showing an outline of a horizontally opposed engine equipped with a turbocharger. An oil pump is arranged inside the engine main body 111 and is attached directly below the crankcase 112 by the oil pump. The oil OL in the oil pan 113 is sucked up and guided to the gallery in the crankcase 112 and the left and right banks 115L and 115R, and the valve operating mechanism in the cylinder head 116L of the left bank 115L and the cylinder head 116R of the right bank 115R. Supplied to the valve mechanism.

  On the other hand, oil OL is supplied to the turbocharger 10 disposed on the lower surface of the right bank 115R through an oil passage branched from the gallery, and the turbocharger 10 is lubricated.

  The oil OL used for lubrication of the turbocharger 10, the air pressurized by the turbine wheel 14 in the turbine chamber 11, and the air pressurized by the compressor wheel 15 in the compressor chamber 12 are gaps between the seal portions 20. The high-pressure turbo blow-by gas that has leaked into the center housing 13 from 20a is located below the turbocharger 10 because the turbocharger 10 is located below the oil level La of the oil OL in the oil pan 113. After being collected in the disposed oil collection tank 121, it is sent from the oil collection tank 121 to the oil pan 113 by the oil circulation pump 122.

  An upper portion of the oil collecting tank 121 is communicated with the crankcase 112 by a pressure adjusting passage 123. As a result, even if the oil circulating pump 122 sucks air in the oil collection tank 121 and the center housing 13 when the oil OL in the oil collection tank 121 is small, the oil collection tank 121 and the center housing 13 The inside does not become negative pressure, and significant generation of turbo blow-by gas is suppressed.

  For example, as schematically shown in FIG. 8, the pressure adjusting passage 123 communicating with the oil collecting tank 121 and the crankcase 112 is a union attached at one end to a pipe 124 connected to the oil collecting tank 121. The union screw 128 is inserted through the banjo 125 and the gaskets 126 and 127, and the union screw 128 is screwed into a threaded portion of a through hole 112 a formed in the crankcase 112.

JP-A-6-257455 JP 2003-343274 A

  According to the turbocharger lubrication structure shown in FIGS. 7 and 8, the oil collection tank 121 for collecting the oil OL from the turbocharger 10 is provided, and the oil collected in the oil collection tank 121 is provided. By sending OL to the oil pan 113 by the oil recirculation pump 122, the turbocharger 10 can be disposed at a position lower than the oil level La of the oil pan 113, the vehicle body center of gravity position can be lowered, and oil collection is performed. By communicating the upper part of the tank 121 with the crankcase 112 through the pressure adjusting passage 123, the oil collection tank 121 and the center housing 13 do not become negative pressure, and significant generation of turbo blow-by gas is suppressed.

  However, a pressure adjusting passage 123 communicating with the inside of the oil collecting tank 121 and the crankcase 112 is formed separately from the engine main body 111 and attached at one end to a pipe 124 connected to the oil collecting tank 121. The union banjo 125 and the gaskets 126 and 127 are formed by inserting the union screw 128 and screwed into the threaded portion of the through hole 112a of the crankcase 112, so that the number of parts constituting the pressure adjusting passage 123 is large. In addition, the configuration becomes complicated, requiring a large number of assembly steps, which causes an increase in manufacturing cost. Furthermore, there is a concern that problems such as oil leakage due to the occurrence of seal failure of the portion due to insufficient tightening force of the union screw 128 or deformation of the gaskets 126 and 126 due to excessive tightening force may occur.

  Accordingly, an object of the present invention made in view of such a point is to avoid problems such as oil leakage from the pressure adjusting passage communicating the oil collecting tank and the crankcase, and to reduce the number of parts and simplify the configuration. It is an object of the present invention to provide a turbocharger lubrication structure that can reduce assembly man-hours and can be expected to reduce manufacturing costs.

  The invention of the lubricating structure of the turbocharger according to claim 1, which achieves the above object, supplies and lubricates oil from an oil pan to the turbocharger disposed at the lower part of the engine body, and An oil collecting tank to which oil discharged from the turbocharger and turbo blow-by gas are supplied, an oil recirculation pump for sending the oil in the oil collecting tank to the oil pan, and an oil collecting tank; In the turbocharger lubrication structure having a pressure adjustment passage communicating with the inside of the crankcase, the oil collection tank is integrally formed with the oil pan, and the pressure adjustment passage has a base end that is the oil collection portion. It is a pressure adjusting pipe that communicates with the inside of the tank and penetrates through the oil pan and is open to the inside of the crankcase.

  According to a second aspect of the present invention, in the lubricating structure for a turbocharger according to the first aspect, the oil collecting tank has a bottomed concave shape with an open top, and an upper edge is coupled to the bottom of the oil pan. The pressure adjusting pipe has a base end coupled to the bottom of the oil pan that divides the oil pan and the oil collecting tank and communicates with the oil collecting tank, and has a tip penetrating the oil pan. It is characterized by being opened in the crankcase.

  According to a third aspect of the present invention, in the lubricating structure of the turbocharger according to the first or second aspect, a base end of the pressure adjusting pipe is fitted into a through hole formed in an oil pan, and the base The entire circumference is brazed to an oil pan.

  According to the first aspect of the present invention, the oil collection tank for collecting the oil used for the turbocharger lubrication and the turbo blow-by gas is formed integrally with the oil pan, and the inside of the oil collection tank and the inside of the crankcase are formed. The pressure adjusting passage is formed by a pressure adjusting pipe whose base end communicates with the oil collecting tank and penetrates through the oil pan and whose tip is opened in the crankcase. It is possible to reliably avoid problems such as oil leakage, and to greatly reduce the number of parts and simplify the configuration as compared with the prior art.

  The oil collection tank and the pressure adjustment pipe are attached to the lower part of the engine body by a simple operation of attaching and connecting the oil pan, which is previously integrated with the oil collection tank and the pressure adjustment pipe, to the crankcase of the engine body. A significant reduction in man-hours can be obtained and a reduction in manufacturing costs can be expected.

  According to the second aspect of the present invention, the oil pan and the oil collection tank can be integrated by joining the upper end periphery of the oil collection tank, which is open at the top, to the bottom of the oil pan. The oil pan, the oil collecting tank, and the pressure adjusting pipe can be integrated by connecting the base end of the pressure adjusting pipe to the bottom of the oil pan that defines the collection tank.

  According to the third aspect of the present invention, the base end of the pressure adjusting pipe is fitted into the through hole formed in the oil pan, and the entire periphery of the base end is brazed to the oil pan. At the same time, the airtightness of the joint between the pressure adjusting pipe and the oil pan can be secured, and the oil in the oil pan can be reliably prevented from leaking into the oil collecting tank.

  Hereinafter, an embodiment of a lubricating structure of a turbocharger according to the present invention will be described with reference to FIGS. 1 to 3 by taking a horizontally opposed engine provided with a turbocharger as an example. In the present embodiment, the turbocharger has substantially the same configuration as the turbocharger shown in FIG. 4, and a detailed description thereof will be omitted.

  FIG. 1 is a partial cross-sectional front view showing an outline of a horizontally opposed engine equipped with a turbocharger, FIG. 2 is a cross-sectional view taken along line II of FIG. 1, and FIG. 3 is an oil system diagram.

  Left and right banks 23L, 23R are provided from a crankcase 22 disposed in the center of the engine body 21. An oil pan 25 serving as an oil reservoir is attached immediately below the crankcase 22, and the turbocharger 10 is disposed below the right bank 23 </ b> R. The turbocharger 10 is configured to store oil OL in the oil pan 25. It is located below the oil level La.

  As shown in FIG. 2, the oil pan 25 has a bottom 26 and a peripheral wall 27 and has a concave shape with its upper part open, and an upper end peripheral edge 27a is shown on the peripheral edge of an opening 22b formed on the lower surface 22a of the crankcase 22. Not attached with bolts.

  An oil collecting tank 31 is coupled to the lower surface of the bottom portion 26 of the oil pan 25. The oil collecting tank 31 is a bottomed concave shape having a bottom 32 and a peripheral wall 33 and opened upward, and the entire periphery of the upper peripheral edge 33a is airtight on the lower surface of the bottom 26 of the oil pan 25 by brazing or the like. Secured and combined.

  A through hole 26a is formed in the bottom 26 of the oil pan 25 that divides the oil pan 25 and the oil collecting tank 31, and the base end 34a of the pressure adjusting pipe 34 is fitted and joined to the through hole 26a. The tip 34b of the pressure adjusting pipe 34 passes through the oil pan 25 and is opened into the crankcase 22. The pressure adjusting pipe 34 passes through the oil pan 25 and passes through the oil collecting tank 31 and the crankcase 22. A pressure adjusting passage communicating with the inside is formed.

  The base end 34a of the pressure adjusting pipe 34 is brazed to the bottom portion 26 of the oil pan 25 over the entire circumference, and the airtightness of the joint portion between the pressure adjusting pipe 34 and the bottom portion 26 of the oil pan 25 is secured. The oil OL in the oil pan 25 is prevented from leaking to the oil collecting tank 31 side when the engine is stopped.

  An oil outlet 18b that opens to the lower part of the center housing 13 of the turbocharger 10 communicates with the upper part of the oil collecting tank 31 via the oil drain communication path 35, and the lower part of the oil collecting tank 31 is connected to the oil circulating pump 38. It communicates with the oil pan 25 through an oil passage 37 in which is interposed.

  An upper portion of the oil collecting tank 31 is communicated with the crankcase 22 by a pressure adjusting pipe 34. Since the inside of the crankcase 22 is always positive pressure, the oil collecting tank 31 and the center housing are not affected even if the oil collecting tank 31 has a small amount of oil OL and the oil circulating pump 38 sucks air in the oil collecting tank 31. The inside of 13 does not become negative pressure, and remarkable generation of turbo blow-by gas is suppressed.

  Next, the oil supply to each part of the oil OL will be described with reference to the oil system diagram shown in FIG.

  With the operation of the engine, the oil pump 39 and the oil recirculation pump 38 disposed inside the engine body 21 are operated, and the oil OL in the oil pan 25 is sucked by the oil pump 39. The oil OL sucked by the oil pump 39 is pumped to the oil cooler 40, the oil temperature is adjusted by the oil cooler 40, and the oil is fed from the oil gallery in the engine body 21 to the lubrication part.

  Specifically, the oil OL guided to the left and right main gallery 41L and 41R on the crankcase 22 side and supplied to the left main gallery 41L is applied to the crankshaft 43L, which is a lubrication portion disposed in the crankcase 22. Oil is fed to lubricate the crankshaft 43L, and is branched from the main gallery 41L to the valve operating mechanism 45L as a lubrication part via a gallery 44L disposed in the cylinder head 24L of the left bank 23L. Lubricate the valve operating mechanism 45L. The oil OL that has lubricated the crankshaft 43L and the valve operating mechanism 45L is collected in the oil pan 25.

  On the other hand, the oil OL supplied to the right main gallery 41R is fed to the crankshaft portion 43R disposed in the crankcase 22 to lubricate the crankshaft portion 43R as a lubrication portion and branch off from the main gallery 41R. Then, oil is fed to the valve operating mechanism 45R through the gallery 44R disposed in the cylinder head 24R of the right bank 23R, and the valve operating mechanism 45R is lubricated. The oil OL that has lubricated the crankshaft 43R and the valve operating mechanism 45R is collected in the oil pan 25.

  Further, the oil OL is supplied to the oil communication passage 47 through the gallery 46R branched from the gallery 44R in the cylinder head 24R. Here, the oil OL is sent from the gallery 40R to the oil inlet 18a of the turbocharger 10 through the oil passage 47.

  The oil OL supplied from the oil inlet 18a is fed through the oil supply passage 19 to the turbine wheel side bearing 16a and the compressor wheel side bearing 16b to lubricate the portion. The oil OL that has lubricated and cooled the turbine wheel side bearing 16a and the compressor wheel side bearing 16b is discharged from the oil outlet 18b that opens to the lower portion of the center housing 13 to the oil collecting tank 31 through the oil drain communication passage 35.

  Here, in the turbocharger 10, the air pressurized by the turbine wheel 14 in the turbine chamber 11 and the air pressurized by the compressor wheel 15 in the compressor chamber 12 pass through the gap 20 a of the seal portion 20 from the center housing 13. Turbo blow-by gas may leak inside.

  On the other hand, the oil OL used for lubrication and cooling of the turbocharger 10 is sucked up from the oil collection tank 31 by the oil circulation pump 38, passes through the crankcase 22, and is returned to the oil pan 25. Here, when there is no pressure adjusting pipe 34, if the oil OL in the oil collecting tank 31 is small, the oil circulating pump 38 sucks up the air in the oil collecting tank, so that the oil collecting tank 31 and the center housing 13 are negative. The pressure difference between the turbine chamber 11 and the compressor chamber 12 becomes large, and turbo blow-by gas is remarkably generated. The oil collection tank 31 has a bottom portion 32 and a peripheral wall 33, and an upper end edge 33 a is coupled to the bottom portion 26 of the oil pan 25 to be integrally formed with the oil pan 25, and the upper portion in the oil collection tank 31 is cranked. A pressure adjusting passage that opens into the case 22 has a base end 34 a coupled to the bottom 26 of the oil pan 25 that divides the oil pan 25 and the oil collecting tank 31, and communicates with the oil collecting tank 31. The tip 34b can be formed by a pressure adjusting pipe 34 that passes through the oil pan 25 and opens into the crankcase 22, and is disposed in the engine main body 21 to reliably avoid oil leakage. On the other hand, the connecting holes such as the union banjo 125 and gaskets 126, 127, etc., through which the union screw 128 drilled in the crankcase screwed in, and the connecting parts such as the union banjo 125 and gaskets 126, 127 are unnecessary, are required. Reduction and simplification of the configuration can be obtained.

  The oil pan 25, the oil collecting tank 31 and the pressure adjusting pipe 34 are coupled to the lower surface of the bottom 26 of the oil pan 25 in advance on the lower end 26a of the oil collecting tank 31 prior to attachment to the engine body 21. The base ends 34a of the pressure adjusting pipes 34 are fitted into the through holes 26a formed in the bottom portion 26 of the oil pan 25 to which the oil collecting tank 31 is connected. By brazing the bottom 26 of the oil pan 25 over the circumference and attaching the oil collecting tank 31 and the pressure adjusting pipe 34 to the oil pan 25, the workability can be improved without being affected by the engine body 21 and other devices. Can be secured easily and efficiently, and the oil pan 25, the oil collecting tank 31 and the pressure adjusting pipe 34 can be integrally coupled and brazed. Oil pan 25 and the coupling portion and the oil pan 25 and the reliability of the coupling portion can reliably ensure airtightness of the coupling portion of the pressure control pipe 34 between the oil collecting tank 31 can be ensured that.

  The oil pan 25, in which the oil collecting tank 31 and the pressure adjusting pipe 34 are integrally coupled, is connected to the tip 34b of the pressure adjusting pipe 34 from the opening 22b formed in the lower surface 22a of the crankcase 22 of the engine body 21. The oil collection tank 31 can be attached to the lower part of the engine body 21 with a simple operation by inserting it into the crankcase 22 and bolting the upper peripheral edge 27a of the oil pan 25 to the lower surface 22a of the crankcase 22. Reduction can be obtained, and a reduction in manufacturing cost can be expected.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above-described embodiment, a horizontally opposed engine provided with one turbocharger has been described as an example. However, application to a horizontally opposed engine provided with a plurality of turbochargers is also possible. The present invention can also be applied to a V-type engine equipped with a supercharger or other types of engines.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional front view showing an outline of a horizontally opposed engine equipped with a turbocharger showing an outline of an embodiment of a lubricating structure for a turbocharger according to the present invention. It is the II sectional view taken on the line of FIG. It is an oil system diagram. It is explanatory drawing of a turbocharger. It is explanatory drawing of the oil seal part used for a turbocharger. It is outline | summary explanatory drawing of the oil leak prevention apparatus of the conventional turbocharger. It is explanatory drawing which shows the outline of the horizontally opposed engine equipped with the turbocharger. It is explanatory drawing of the conventional pressure adjusting channel | path.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Turbocharger 21 Engine main body 22 Crankcase 22a Lower surface 22b Opening 23L, 23R Bank 24L, 24R Cylinder head 25 Oil pan 26 Bottom 26a Through-hole 27 Peripheral wall 27a Upper peripheral edge 31 Oil collection tank 32 Bottom 33 Peripheral wall 33a Upper peripheral edge 34 Pressure adjustment pipe (pressure adjustment passage)
34a Base end 34b Tip 35 Oil drain communication passage 37 Oil passage 38 Oil recirculation pump 39 Oil pump

Claims (3)

An oil collecting tank to which oil from an oil pan is supplied and lubricated to a turbocharger disposed at the lower part of the engine body, and oil discharged from the turbocharger and turbo blow-by gas is supplied. A turbocharger lubrication structure comprising an oil recirculation pump for sending oil in the oil collection tank to the oil pan and a pressure adjusting passage for communicating between the oil collection tank and the crankcase;
The oil collecting tank is integrally formed with the oil pan,
The turbocharger characterized in that the pressure adjusting passage is a pressure adjusting pipe having a base end communicating with the oil collecting tank and penetrating through the oil pan and having a distal end opened to the crankcase. Lubrication structure. The oil collection tank has a bottomed concave shape with an open top, and an upper edge is coupled to the bottom of the oil pan.
The pressure adjusting pipe has a base end coupled to the bottom of the oil pan that divides the oil pan and the oil collecting tank and communicates with the oil collecting tank, and has a tip penetrating the oil pan. 2. The turbocharger lubricating structure according to claim 1, wherein the lubricating structure is open in the crankcase.   The base end of the pressure adjusting pipe is fitted into a through-hole formed in an oil pan, and the entire base end is brazed to the oil pan. Turbocharger lubrication structure.

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