JP2015038331A - Lubrication oil supply system of turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication oil supply system of a turbocharger which limits an amount of a lubrication oil in the turbocharger and thereby improves the mechanical efficiency.SOLUTION: A lubrication oil supply system 1 of a turbocharger 5 supplies a lubrication oil to the turbocharger 5 and discharges the lubrication oil from the turbocharger 5. The lubrication oil supply system 1 of the turbocharger 5 includes: a flow control valve 4 which is disposed at the upstream side relative to the turbocharger 5 and limits a flow rate of the lubrication oil supplied to the turbocharger 5; and a second oil pump 6 which is disposed at the downstream side relative to the turbocharger 5 and generates a negative pressure to suction and discharge the lubrication oil in the turbocharger 5. The lubrication oil supply system 1 further includes an ECU 7 which controls the operation of the second oil pump 6 to control an amount of the lubrication oil discharged from the second oil pump 6.

Description

  The present invention relates to a technology of a lubricating oil supply system for a turbocharger that supplies lubricating oil to a turbocharger and discharges the lubricating oil from the turbocharger.

  2. Description of the Related Art Conventionally, a technology of a lubricating oil supply system for a turbocharger that supplies lubricating oil to a turbocharger and discharges the lubricating oil from the turbocharger is known. For example, as described in Patent Document 1.

  In the technique described in Patent Document 1, the oil stored in the oil pan is supplied to the turbocharger by driving the oil pump. The bearing portion of the turbocharger is lubricated by the lubricating oil. Further, the lubricating oil that has lubricated the bearing portion of the turbocharger travels downward in the turbocharger due to its own weight, and is collected again into the oil pan.

  However, in the technique described in Patent Document 1, since the lubricating oil pumped by the oil pump is supplied to the turbocharger without any limitation, an excessive amount of lubricating oil is supplied to the turbocharger. There is a case. When an excessive amount of lubricating oil is present in the turbocharger, the stirring resistance in the turbocharger increases, which is disadvantageous in that mechanical efficiency may be reduced.

JP 2012-21426 A

  The present invention has been made in view of the above situation, and the problem to be solved is that of a turbocharger capable of improving mechanical efficiency by limiting the amount of lubricating oil in the turbocharger. It is to provide a lubricating oil supply system.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, while supplying the lubricating oil to the turbocharger, the lubricating oil supply system of the turbocharger that discharges the lubricating oil from the turbocharger, which is disposed upstream of the turbocharger, Flow rate limiting means for limiting the flow rate of the lubricating oil supplied to the turbocharger and the downstream side of the turbocharger, and sucking the lubricating oil in the turbocharger by generating a negative pressure Negative pressure generating means for discharging.

  According to a second aspect of the present invention, the apparatus further comprises control means for controlling the operation of the negative pressure generating means and controlling the amount of lubricating oil discharged by the negative pressure generating means.

  According to a third aspect of the present invention, there is further provided control means for controlling the operation of the flow restriction means and controlling the restriction amount of the flow rate of the lubricating oil by the flow restriction means.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, while restricting the flow rate of the lubricating oil supplied to the turbocharger and forcibly discharging the lubricating oil in the turbocharger, the amount of lubricating oil in the turbocharger can be limited. The mechanical efficiency can be improved. In addition, it is possible to prevent problems (white smoke, coking, seizure) in which lubricating oil accumulates in the turbocharger bearing.

  In claim 2, the amount of lubricating oil in the turbocharger can be arbitrarily adjusted.

  In claim 3, the amount of lubricating oil in the turbocharger can be arbitrarily adjusted.

The schematic diagram which showed the whole structure of the lubricating oil supply system which concerns on 1st embodiment of this invention. Side surface sectional drawing of a turbocharger. The schematic diagram which showed the whole structure of the lubricating oil supply system which concerns on 2nd embodiment of this invention.

  In the following description, the front-rear direction and the vertical direction are defined according to the arrows shown in the figure.

  Below, the whole structure of the lubricating oil supply system 1 of the turbocharger 5 which concerns on one Embodiment (1st embodiment) of this invention is demonstrated.

  A lubricating oil supply system 1 shown in FIG. 1 supplies lubricating oil to the turbocharger 5 and discharges the lubricating oil from the turbocharger 5. The lubricating oil supply system 1 mainly includes an oil pan 2, a first oil pump 3, a flow rate control valve 4, a turbocharger 5, a second oil pump 6, and an ECU 7.

  The oil pan 2 is provided at the lower part of an engine (not shown) and stores lubricating oil.

The first oil pump 3 supplies (pressure feeds) lubricating oil stored in the oil pan 2 to a turbocharger 5 and a part (portion requiring lubrication) of the engine which will be described later.
In the drawing, only an oil passage for supplying lubricating oil from the first oil pump 3 to the turbocharger 5 is shown.

  The flow control valve 4 is an embodiment of the flow restriction means according to the present invention, and restricts the amount of lubricating oil (lubricant flow) supplied from the first oil pump 3 to the turbocharger 5. . The flow control valve 4 is connected to the downstream side of the first oil pump 3. The flow control valve 4 appropriately throttles the oil passage through which the lubricating oil flows based on the balance between the biasing force of the spring 4b that biases the spool 4a and the hydraulic pressure on the first oil pump 3 side (primary side). be able to. Accordingly, the flow control valve 4 can limit the amount of lubricating oil supplied from the first oil pump 3 to the turbocharger 5.

  The turbocharger 5 is for sending compressed air into the cylinder of the engine. The turbocharger 5 is connected to the downstream side of the flow control valve 4. A specific configuration of the turbocharger 5 will be described later.

  The second oil pump 6 is an embodiment of the negative pressure generating means according to the present invention, and sucks and discharges the lubricating oil in the turbocharger 5 by generating a negative pressure. The second oil pump 6 is connected to the downstream side of the turbocharger 5. The operation of the second oil pump 6 is configured to be electronically controllable. The lubricating oil discharged from the second oil pump 6 is returned again to the oil pan 2 through the oil passage.

  The ECU 7 is an embodiment of the control means according to the present invention, and controls the operation of the second oil pump 6. The ECU 7 includes a storage unit, an arithmetic processing unit, and the like, and stores a program for controlling the second oil pump 6 and various data. The ECU 7 is connected to the second oil pump 6 and can control the operation of the second oil pump 6, that is, the amount of lubricating oil sucked by the second oil pump 6.

  Next, a specific configuration of the turbocharger 5 will be described with reference to FIG. The turbocharger 5 mainly includes a shaft 11, a compressor wheel 12, a turbine wheel 13, a bearing housing 14, a compressor housing 15, a turbine housing 16, a slide bearing 17, a thrust collar 18, a thrust bearing 19, and a retainer seal 20.

  The shaft 11 is disposed with its longitudinal direction (axial direction) directed in the front-rear direction. A compressor wheel 12 is fixed to one end (rear end) of the shaft 11, and a turbine wheel 13 is fixed to the other end (front end) of the shaft 11. In this way, the shaft 11 connects the compressor wheel 12 and the turbine wheel 13.

  The bearing housing 14 is an embodiment of the housing according to the present invention, and includes the shaft 11 and supports the shaft 11 rotatably. A bearing portion 14 a is formed in the bearing housing 14.

  The bearing portion 14a is a portion that supports the shaft 11 so as to be indirectly rotatable. The bearing portion 14a has a circular cross section and is formed so as to penetrate the bearing housing 14 in the front-rear direction.

  The compressor housing 15 contains the compressor wheel 12. The compressor housing 15 is fixed to the rear portion of the bearing housing 14 and is formed so as to cover the compressor wheel 12.

  The turbine housing 16 contains the turbine wheel 13. The turbine housing 16 is fixed to the front portion of the bearing housing 14 and is formed so as to cover the turbine wheel 13.

  The slide bearing 17 is a substantially cylindrical bearing that rotatably supports the shaft 11. The slide bearing 17 is disposed in the bearing portion 14 a of the bearing housing 14. The shaft 11 is inserted into the slide bearing 17.

  The thrust collar 18 is disposed behind the slide bearing 17. The shaft 11 is inserted through the thrust collar 18. The thrust bearing 19 is fitted on the thrust collar 18. The axial bearing of the shaft 11 is received by the thrust bearing 19. The retainer seal 20 is fitted on the shaft 11 behind the thrust bearing 19.

  In the turbocharger 5 configured as described above, the turbine wheel 13 rotates by receiving high-temperature air (exhaust gas) after combustion in the cylinder of the engine. The rotation of the turbine wheel 13 is transmitted to the compressor wheel 12 via the shaft 11, and the compressor wheel 12 rotates. Then, the compressor wheel 12 rotates to compress the air, and the compressed air can be supplied to the engine cylinder.

  Next, the configuration of the flow path (oil path) through which the lubricating oil flows when circulating in the turbocharger 5 will be described. In FIG. 2, the state in which the lubricating oil is circulated is indicated by white arrows.

  An oil supply oil passage 14 b is formed in the upper portion of the bearing housing 14. The oil supply passage 14b communicates with an oil supply port 14e formed on the upper surface of the bearing housing 14 and an upper portion of the bearing portion 14a. The lubricating oil (see FIG. 1) supplied from the first oil pump 3 via the flow rate control valve 4 flows into the oil supply passage 14b from the oil supply port 14e and is supplied to the upper portion of the bearing portion 14a. .

  The lubricating oil supplied to the upper portion of the bearing portion 14a through the oil supply passage 14b lubricates between the inner peripheral surface of the bearing portion 14a and the outer peripheral surface of the slide bearing 17. Further, the sliding bearing 17 is formed with an oil passage 17a penetrating the outside (outer peripheral surface) and the inside (inner peripheral surface). The lubricating oil supplied to the bearing portion 14 a is supplied to the inside of the sliding bearing 17 through the oil passage 17 a and lubricates between the inner peripheral surface of the sliding bearing 17 and the shaft 11.

  A drain oil passage 14 c is formed in the lower portion of the bearing housing 14. The discharge oil passage 14c communicates the discharge port 14f formed on the bottom surface of the bearing housing 14 with both the front and rear end portions of the bearing portion 14a. The lubricating oil lubricated in the bearing portion 14a flows into the discharge oil passage 14c and is discharged from the discharge port 14f to the outside of the bearing housing 14 (more specifically, the second oil pump 6 (see FIG. 1)). Is done.

  Next, the configuration of the flow path (cooling water path) through which the cooling water passes when circulating in the turbocharger 5 will be described.

  A cooling water passage 14 d is formed in the bearing housing 14. The cooling water channel 14d is formed so as to surround the vicinity of the front end portion of the bearing portion 14a. The bearing housing 14 is formed with a water supply port (not shown) and a drainage port (not shown) that communicate the outside of the bearing housing 14 with the cooling water passage 14d.

  Cooling water supplied from the outside flows into the cooling water channel 14d through the water supply port. The cooling water that has flowed into the cooling water passage 14d cools the turbocharger 5 (particularly, the bearing portion 14a of the bearing housing 14), and is then discharged to the outside through the drainage port.

  Hereinafter, a state in which the amount of lubricating oil in the turbocharger 5 is limited in the lubricating oil supply system 1 configured as described above will be described with reference to FIG.

  The lubricating oil pumped at a predetermined pressure by the first oil pump 3 is supplied to the turbocharger 5 after the flow rate is limited by the flow rate control valve 4. Thereby, it is possible to prevent excessive lubricating oil from being supplied to the turbocharger 5.

  The lubricating oil in the turbocharger 5 is sucked by the negative pressure generated by the second oil pump 6 and discharged from the turbocharger 5. At this time, the lubricating oil in the lubricating oil formed in the turbocharger 5 is not necessarily filled, and the lubricating oil and air may be mixed. As a result, it is possible to prevent the lubricating oil from remaining excessively in the turbocharger 5, increasing the stirring resistance, and lowering the mechanical efficiency.

Further, the amount of lubricating oil leaking from the turbocharger 5 to the outside can be reduced by sucking the lubricating oil in the turbocharger 5 by the second oil pump 6.
Specifically, the lubricating oil in the turbocharger 5 may leak backward (compressor wheel 12 side) through a gap around the retainer seal 20. Further, the lubricating oil in the turbocharger 5 may leak forward (to the turbine wheel 13 side) via the bearing portion 14 a of the bearing housing 14. However, such a leakage of the lubricating oil from the turbocharger 5 can be suppressed by generating a negative pressure by the second oil pump 6 and sucking the lubricating oil in the turbocharger 5.

Further, since the lubricating oil in the turbocharger 5 is sucked and discharged by the second oil pump 6, the degree of freedom in the flow direction of the lubricating oil flowing in the turbocharger 5 (the degree of freedom in design) is increased. improves.
Specifically, when the second oil pump 6 is not used, it is usual to supply lubricating oil from above to the turbocharger 5 and transfer the lubricating oil from above to below by its own weight. However, by using the second oil pump 6 as in the present embodiment, it is possible to supply the lubricating oil from below to the turbocharger 5 and to discharge the lubricating oil from above the turbocharger 5. In addition, it is possible to supply lubricating oil from the side to the turbocharger 5 and discharge the lubricating oil from the side as well.

  Furthermore, the amount of lubricating oil in the turbocharger 5 can be arbitrarily adjusted by controlling the operation of the second oil pump 6 by the ECU 7.

  For example, by increasing the amount of lubricating oil sucked by the second oil pump 6, a large amount of lubricating oil in the turbocharger 5 can be discharged, and the amount of lubricating oil in the turbocharger 5 can be reduced. When sufficient lubrication is possible even with a small amount of lubricating oil in the turbocharger 5 (for example, when the rotational speed of the shaft 11 is low (during low rotation), etc.), the amount of lubricating oil in the turbocharger 5 is decreased, thereby stirring. Resistance can be reduced and mechanical efficiency can be improved.

  Further, by reducing the amount of lubricating oil sucked by the second oil pump 6, the amount of lubricating oil discharged in the turbocharger 5 can be reduced and the amount of lubricating oil in the turbocharger 5 can be increased. When a large amount of lubricating oil is required in the turbocharger 5 (for example, when the rotational speed of the shaft 11 is high (during high rotation)), the amount of lubricating oil in the turbocharger 5 is increased to increase the turbocharger 5. The charger 5 can be sufficiently lubricated.

  Further, when starting the engine, the amount of lubricating oil sucked by the second oil pump 6 is increased and the amount of lubricating oil in the turbocharger 5 is decreased, so that the lubricating oil in the turbocharger 5 can be quickly warmed. it can. As a result, the viscosity of the lubricating oil can be quickly reduced and the flow resistance can be reduced.

  If the amount of lubricating oil in the turbocharger 5 is limited as described above, the cooling effect of the turbocharger 5 by the lubricating oil is reduced. Therefore, it is desirable to provide a separate mechanism for cooling the turbocharger 5 (for example, a large flow rate cooling water channel) to sufficiently cool the turbocharger 5.

As described above, the lubricating oil supply system 1 for the turbocharger 5 according to the present embodiment supplies the lubricating oil to the turbocharger 5 and discharges the lubricating oil from the turbocharger 5. 1, which is disposed upstream of the turbocharger 5 and restricts the flow rate of the lubricating oil supplied to the turbocharger 5, and downstream of the turbocharger 5. And a second oil pump 6 (negative pressure generating means) that sucks and discharges lubricating oil in the turbocharger 5 by generating negative pressure.
With this configuration, the flow rate of the lubricating oil supplied to the turbocharger 5 is limited, and the lubricating oil in the turbocharger 5 is forcibly discharged to reduce the amount of lubricating oil in the turbocharger 5. It is possible to limit the mechanical efficiency. Moreover, the malfunction (white smoke, coking, seizure) which lubricating oil (oil) accumulates in the bearing part 14a of the turbocharger 5 can be prevented.

Further, the lubricating oil supply system 1 of the turbocharger 5 according to the present embodiment controls an operation of the second oil pump 6 and an ECU 7 (control means) that controls the amount of lubricating oil discharged by the second oil pump 6. Furthermore, it is equipped.
With this configuration, the amount of lubricating oil in the turbocharger 5 can be arbitrarily adjusted.

Below, the lubricating oil supply system 1 of the turbocharger 5 which concerns on 2nd embodiment of this invention is demonstrated using FIG.
The lubricating oil supply system 1 according to the second embodiment is mainly different from the lubricating oil supply system 1 according to the first embodiment (see FIG. 1) in that a flow control valve 8 is provided instead of the flow control valve 4. It is a point to do. Therefore, only the difference in the configuration will be described below.

  The flow rate control valve 8 is an embodiment of the flow rate limiting means according to the present invention, and limits the amount of lubricating oil supplied from the first oil pump 3 to the turbocharger 5. The flow control valve 8 is connected to the downstream side of the first oil pump 3 and to the upstream side of the turbocharger 5. The flow control valve 8 can appropriately throttle the oil passage through which the lubricating oil flows based on the balance between the urging force of the spring 8b that urges the spool 8a and the urging force of the solenoid 8c.

  The ECU 7 is connected to the solenoid 8c of the flow control valve 8 and can control the operation of the solenoid 8c.

  In the lubricating oil supply system 1 configured as described above, the amount of lubricating oil in the turbocharger 5 can be arbitrarily adjusted by controlling the operation of the flow control valve 8 (solenoid 8c) by the ECU 7.

For example, by narrowing the oil passage of the flow control valve 8, the amount of lubricating oil supplied from the first oil pump 3 to the turbocharger 5 can be reduced, and the amount of lubricating oil in the turbocharger 5 can be reduced. .
Further, by expanding the oil passage of the flow control valve 8, the amount of lubricating oil supplied from the first oil pump 3 to the turbocharger 5 can be increased, and the amount of lubricating oil in the turbocharger 5 can be increased. .

As described above, the lubricating oil supply system 1 of the turbocharger 5 according to the present embodiment controls the operation of the flow rate control valve 8 (flow rate restricting means), and controls the limit amount of the lubricating oil flow rate by the flow rate control valve 8. The ECU 7 (control means) is further provided.
With this configuration, the amount of lubricating oil in the turbocharger 5 can be arbitrarily adjusted.

  In the above embodiment, the flow rate control valve 4 and the flow rate control valve 8 are used as the flow rate limiting unit according to the present invention, but the configuration of the flow rate limiting unit is not limited to this. That is, the flow rate restricting means may be any means that can restrict the amount of lubricating oil supplied to the turbocharger 5.

  In the above embodiment, the second oil pump 6 is used as the negative pressure generating means according to the present invention. However, the configuration of the second oil pump 6 is not limited, and various types of pumps are used. Is possible. Further, the configuration of the negative pressure generating means is not limited to the pump. That is, the negative pressure generating means may be any means that can suck and discharge the lubricating oil in the turbocharger 5.

  Moreover, in the said embodiment, although ECU7 was used as a control means which concerns on this invention, the structure of a control means is not restricted to this. That is, the control means only needs to be able to control the operation of the second oil pump 6 and the flow rate control valve 8.

  Moreover, the part which attaches the flow control valve 4 (flow control valve 8) and the 2nd oil pump 6 in the said embodiment is not specifically limited. That is, the flow control valve 4 and the like can be fixed to the turbocharger 5 or to the engine, and can also be fixed to a device (for example, an automobile) provided with the engine.

Moreover, in the said embodiment, although the detail of the oil path which guides lubricating oil from the oil pan 2 to the flow control valve 4 (flow control valve 8) is not mentioned, the said oil path is not specifically limited. Absent. For example, the lubricating oil from the oil pan 2 may be supplied to the flow control valve 4 or the like after being fed by the first oil pump 3 and then flowing through the cylinder block of the engine. The configuration may be such that it is supplied to the flow control valve 4 or the like after flowing through the cylinder head instead of the block. In order to limit the amount of lubricating oil in the flow control valve 4 and the like with higher accuracy, it is desirable that the lubricating oil be supplied via a cylinder head with relatively less vibration than the cylinder block.
Further, since it is considered that the oil passage that circulates the cylinder head is relatively less contaminated than the oil passage that circulates the cylinder block, it is possible to prevent contamination and damage of the flow control valve 4 and the like due to the foreign matter. Therefore, it is desirable to supply the lubricating oil to the flow control valve 4 and the like through the cylinder head.

  In the above embodiment, the lubricating oil is supplied from the oil pan 2 of the engine to the turbocharger 5 and the lubricating oil discharged from the turbocharger 5 is returned to the oil pan 2 again. The invention is not limited to this. For example, it is possible to provide a configuration in which a lubricating oil for lubricating the turbocharger 5 and a tank for storing the lubricating oil are provided separately from the oil pan 2 and the lubricating oil of the engine. At this time, it is possible to control (limit) the amount of lubricating oil flowing through the turbocharger 5 with higher accuracy by installing the tank or the like in a place that is not easily affected by the vibration of the engine.

  Moreover, the control method of the 2nd oil pump 6 and the flow control valve 8 which were shown in the said embodiment is an example, and this invention does not limit the control method. That is, the amount of lubricating oil sucked by the second oil pump 6 can be increased or decreased at an arbitrary timing, or the amount of lubricating oil flowing through the flow control valve 8 can be increased or decreased. In addition to the suction timing of the lubricating oil by the negative pressure generating means (second oil pump 6), the negative pressure can be increased only under conditions where the lubricating oil is likely to leak by controlling the suction strength.

  Further, the oil amount control of the lubricating oil by the ECU 7 (control means) can be performed by sensing (detecting) the rotational speed of the engine, the rotational speed of the turbocharger 5 (turbo), the pressure, the flow rate, etc. Sensing (detection) targets for the control are not limited to those described here.

  Moreover, in the said embodiment, although it was set as the structure which provides the 2nd oil pump 6 for exclusive use for adjusting the amount of lubricating oil in the turbocharger 5, this invention is not limited to this. That is, the second oil pump 6 can be shared by a previously provided pump. For example, a configuration in which the amount of lubricating oil in the turbocharger 5 is adjusted using a vacuum pump or the like for assisting braking of an automobile provided with the engine may be employed. In this way, it is possible to reduce costs by also using parts.

  In addition, the specific configuration of the turbocharger 5 shown in the above embodiment is an example, and the present invention does not limit the configuration of the turbocharger 5. For example, the bearing housing 14 can be divided and configured by a plurality of members. Specifically, a part of the bearing housing 14 on the turbine wheel 13 side is configured as a separate body (separate member), and the member is formed of a highly heat-insulating material, so that the turbine wheel 13 side to the turbocharger 5 is formed. Heat transfer can be suppressed. Further, an oil passage for the lubricating oil and a cooling water passage that circulates in the turbocharger 5 can be arbitrarily formed.

1 Lubricating oil supply system 2 Oil pan 3 First oil pump 4 Flow control valve (flow restricting means)
5 Turbocharger 6 Second oil pump (negative pressure generating means)
7 ECU (control means)

Claims (3)

A lubricating oil supply system for a turbocharger that supplies lubricating oil to a turbocharger and discharges the lubricating oil from the turbocharger,
A flow rate limiting means that is arranged upstream of the turbocharger and limits the flow rate of lubricating oil supplied to the turbocharger;
A negative pressure generating means that is disposed downstream of the turbocharger and sucks and discharges the lubricating oil in the turbocharger by generating a negative pressure;
A turbocharger lubricating oil supply system. Further comprising control means for controlling the operation of the negative pressure generating means and controlling the amount of lubricant discharged by the negative pressure generating means.
The turbocharger lubricating oil supply system according to claim 1. Further comprising control means for controlling the operation of the flow restriction means and controlling the restriction amount of the flow rate of the lubricating oil by the flow restriction means.
The turbocharger lubricating oil supply system according to claim 1 or 2.

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