JP2005090403A - Lubrication control device for supercharger with electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supercharger with an electric motor capable of causing the electric motor supercharger to exhibit good performance by always supplying an optimum amount of lubricating oil to the supercharger with an electric motor. Providing a lubrication control device for
A lubrication control device for a supercharger with an electric motor according to the present invention is provided on an intake passage 3 of an internal combustion engine 1 mounted on a vehicle, and is driven by a rotary electric motor 2b. Lubricating oil supply means 8 to 10 for supplying lubricating oil to the vicinity of the rotating shaft 2a of the electric motor 2b, and control means 6 and 7 for controlling the supply of lubricating oil by the lubricating oil supply means 8 to 10 are provided. Nos. 6 and 7 are characterized in that, when the electric motor 2b is driven to rotate, the amount of lubricating oil supplied to the vicinity of the rotary shaft 2a increases as the rotational speed of the electric motor 2b increases.
[Selection] Figure 1

Description

  The present invention relates to a lubrication control device that controls the supply of lubricating oil to a supercharger with an electric motor disposed on an intake passage.

As described in [Patent Document 1], a supercharger driven by an electric motor is disposed on an intake passage of an engine, and high output (or low fuel consumption) is obtained by supercharging by the supercharger. Attempts have been known for a long time. In the turbo unit described in [Patent Document 1], engine lubricating oil is circulated around the motor to perform lubrication and cooling.
JP-T-2001-527613

  However, in the turbo unit described in [Patent Document 1], since the motor is lubricated and cooled using the engine lubricating oil, the lubricating oil is supplied with a constant circulation amount corresponding to the lubricating oil circulation on the engine side. It is only circulated. For this reason, the case where the amount of lubricating oil is not appropriate depending on the driving state of the electric motor is also assumed. For example, there is a concern that when the motor is driven at a high rotation speed under a high load to obtain the maximum turbocharging effect by the turbo unit, the lubricating oil amount is insufficient and sufficient lubrication / cooling is not performed. The Accordingly, an object of the present invention is to provide a supercharger with an electric motor that can cause the electric motor supercharger to exhibit good performance by always supplying an optimal amount of lubricating oil to the supercharger with an electric motor. The object is to provide a lubrication control device.

  A lubrication control device for a supercharger with an electric motor according to claim 1 is provided on an intake passage of an internal combustion engine mounted on a vehicle and is driven by a rotary electric motor, and in the vicinity of a rotation shaft of the electric motor And a control means for controlling the supply of the lubricating oil by the lubricating oil supply means, and the control means increases the rotational speed of the motor when the motor is driven to rotate. It is characterized by increasing the amount of lubricating oil supplied to the vicinity of the rotating shaft.

  According to a second aspect of the present invention, in the lubrication control device for a supercharger with an electric motor according to the first aspect, when the control means has the same driving rotational speed of the electric motor, the higher the lubricating oil temperature, the higher the rotating shaft. The amount of lubricating oil supplied to the vicinity is increased, and when the rotational speed of the electric motor is equal to or lower than the predetermined rotational speed, the supplied amount is set to the predetermined amount regardless of the driving rotational speed of the electric motor and the lubricating oil temperature. Yes.

  According to the lubrication control device for a supercharger with an electric motor according to claim 1, when the motor is driven to rotate, the control means adjusts the amount of lubricating oil supplied according to the number of revolutions of the motor (the higher the number of revolutions, the more lubricant oil is supplied. Therefore, the optimum amount of lubricating oil can always be supplied to the supercharger with electric motor, and the electric motor supercharger can exhibit good performance. For example, when the motor rotates at a high speed, the lubrication oil supply amount is increased so that reliable lubrication and sufficient cooling are performed, and at a low rotation, the lubrication oil supply amount is kept low while maintaining a lubrication / cooling amount. In this way, the motor supercharger exhibits good performance by suppressing the increase in motor rotation resistance due to the viscosity of the lubricating oil.

  According to the lubrication control device for a supercharger with an electric motor according to claim 2, when the drive rotational speed of the electric motor is the same, the supply amount of the lubricating oil to the vicinity of the rotation shaft is increased as the lubricating oil temperature is higher. . Even if the drive rotation speed of the electric motor is the same (equivalent), the oil film is more likely to be cut off as the lubricating oil temperature is higher. For this reason, as the lubricating oil temperature is higher, the supply amount is increased to prevent the oil film from running out, and the motor supercharger exhibits good performance. Further, when the amount of lubricating oil is large, the rotational resistance of the electric motor is likely to be caused by the viscosity of the lubricating oil. For this reason, when the lubricating oil temperature is low and the viscosity is high, the lubricating oil supply amount is suppressed (in other words, the lubricating oil supply amount is increased as the lubricating oil temperature increases and the viscosity decreases). Demonstrate good performance. That is, here, the supply of the lubricating oil to the electric motor is controlled in consideration of the lubricating oil temperature in addition to the rotational speed of the electric motor.

  Furthermore, when the rotational speed of the electric motor is equal to or lower than the predetermined rotational speed, it is easily affected by the viscosity of the lubricating oil. An increase in the rotational resistance of the motor due to the viscosity of the lubricating oil deteriorates the response of the supercharger (particularly, the response at the time of transient when supercharging using the motor is performed). For this reason, when the rotational speed of the motor is equal to or lower than the predetermined rotational speed, the motor rotation resistance increases due to the viscosity of the lubricating oil by setting the supply amount below the predetermined amount regardless of the driving rotational speed of the motor and the lubricating oil temperature. This makes the electric motor supercharger perform well.

  An embodiment of the control device of the present invention will be described below. An engine 1 having a control device of the present embodiment is shown in FIG. An engine (internal combustion engine) 1 described in the present embodiment is a multi-cylinder engine, but only one cylinder is shown in FIG. 1 as a cross-sectional view. The engine 1 has a turbo unit (supercharger) 2. In the turbo unit 2, a compressor wheel disposed on the intake passage 3 and a turbine wheel disposed on the exhaust passage 4 are connected by the same rotation shaft (hereinafter, this portion is simply referred to as a turbine / compressor 2a). . The turbo unit of the present embodiment incorporates a motor (electric motor) 2b so that the rotating shaft serves as an output shaft. That is, the turbo unit 2 of this embodiment is a turbocharger with an electric motor (compressor with an electric motor).

  The turbo unit 2 can function as a normal supercharger that performs supercharging with the energy (exhaust energy) of the exhaust flow, but forcibly drives the turbine / compressor 2a with electric energy supplied from the battery 5. It is possible to carry out further supercharging. Further, the exhaust energy can be used to cause the motor 2b to perform regenerative power generation via the turbine / compressor 2a to recover the electric power. That is, the turbocharger with electric motor of this embodiment can also function as a turbine with generator. For this reason, the motor 2b is sometimes called a motor generator (MG).

  The motor 2b has a rotor fixed to the rotating shaft of the turbine / compressor 2a and a stator disposed around the rotor as main components. Inside the motor 2b, a temperature sensor 2c for detecting the lubricating oil temperature of the rotating shaft portion of the turbine / compressor 2a is incorporated. In the present embodiment, the temperature sensor 2c is installed on the exhaust side of the rotating shaft that becomes high temperature, but may be installed on the intake side. The temperature sensor 2c is connected to a controller 6 that controls the turbo unit 2 having the motor 2b, and the controller 6 monitors the lubricating oil temperature of the rotating shaft portion.

  The motor 2b is also connected to the controller 6 described above. The controller 6 is connected to an electronic control unit (ECU) 7 that controls the entire engine 1. The controller 6 is also connected to the battery 5 and is supplied with power from the battery 5. In the motor 2b, the applied electric power and the like are controlled by the ECU 7 and the controller 6, and thereby the rotational speed control, that is, the supercharging pressure control is performed. The rotation speed of the turbine / compressor 2a (that is, the rotation speed of the motor 2b and the turbo rotation speed) can be detected by the motor 2b. This rotational speed detection can be performed even when the motor 2b is driven or not. The controller 6 not only controls the driving of the motor 2b, but also has a function as an inverter that performs voltage conversion of electric power regenerated by the motor 2b. The electric power generated by the regenerative power generation is converted into a voltage by the controller 6 and then charged into the battery 5 or directly consumed by the engine 1 and other electrical equipment.

  The turbo unit 2 is also connected with an oil flow path 8 for circulating lubricating oil in the vicinity of the rotating shaft of the turbine / compressor 2a. The turbo unit 2 of the present embodiment lubricates and cools the rotating shaft of the turbine / compressor 2a with the circulated lubricating oil. This lubricating oil circulation has an effect of cooling not only the rotating shaft of the turbine / compressor 2a but also the entire turbo unit 2. The oil flow path 8 is connected to an oil pan 9 that stores lubricating oil for circulation and cooling of the turbo unit 2. An electric pump 10 that sends lubricating oil from the oil pan 9 toward the turbo unit 2 is also disposed on the oil flow path 8.

  The pump 10 is also connected to the controller 6, and its driving is controlled by the controller 6. That is, by controlling the driving of the pump 10 by the controller 6, the circulation amount of the lubricating oil (the supply amount to the turbo unit 2) is controlled. These oil flow path 8, oil pan 9, pump 10, etc. function as lubricating oil supply means. Further, the controller 6 and the ECU 7 function as control means. The controller 6 and the ECU 7 are electronic control units including a CPU, a ROM, a RAM, and the like.

  FIG. 2 shows a flowchart when the amount of lubricating oil to the turbo unit (supercharger) 2 is controlled by the control device having the above-described configuration. First, the rotational speed of the motor 2b and the lubricating oil temperature, which are parameters for determining the amount of lubricating oil, are detected (step 200). As described above, the rotational speed of the motor 2b (the rotational speed of the turbine / compressor 2a [rotary shaft]: turbo rotational speed) can be detected by the motor 2b itself. The lubricating oil temperature is detected by the temperature sensor 2c at the exhaust side rotating shaft of the turbine / compressor 2a. Next, it is determined whether or not supercharging assist is being performed by the motor 2b (step 210).

  When supercharging assistance is performed by the motor 2b, the amount of lubricating oil is determined from the map shown in FIG. 3 based on the rotational speed of the motor 2b and the lubricating oil temperature detected in step 200 (step 220). As can be seen from the map in FIG. 3, the amount of lubricating oil is increased as the driving speed of the motor 2 b is higher. In this way, when the motor 2b is rotating at a high speed, the amount of lubricating oil is increased to prevent oil shortage and the like, thereby realizing reliable lubrication and taking away more heat from the turbo unit 2 for sufficient cooling. It is supposed to be. Further, during the low rotation of the motor 2b, the amount of lubricating oil is reduced while maintaining the amount necessary for lubrication and cooling, thereby suppressing an increase in rotational resistance due to the viscosity of the lubricating oil.

  Further, from the map of FIG. 3, it can be seen that when the driving speed of the motor 2 b is the same, the amount of lubricating oil increases as the lubricating oil temperature increases. Even if the driving speed of the motor 2b is constant, the oil film is more likely to be cut off as the lubricating oil temperature is higher. For this reason, the higher the lubricating oil temperature is, the more the amount of lubricating oil is increased to prevent oil film breakage. Further, if the amount of lubricating oil is large, the rotational resistance of the motor 2b is likely to be caused by the viscosity of the lubricating oil. For this reason, when the lubricating oil temperature is low and the viscosity is large, the lubricating oil supply amount is suppressed, that is, the lubricating oil amount is increased as the lubricating oil temperature becomes higher (viscosity becomes smaller). Turbo lag caused by increased rotation of the motor 2b is suppressed.

  Further, from the map of FIG. 3, when the rotational speed of the motor 2b is equal to or lower than the predetermined rotational speed, the lubricating oil amount is equal to or smaller than the predetermined amount (here, a constant value) regardless of the driving rotational speed of the motor 2b and the lubricating oil temperature. ). When the rotational speed of the motor 2b is low, it is easily affected by the viscosity of the lubricating oil. An increase in rotational resistance due to the viscosity of the lubricating oil causes turbo lag. In particular, the response at the time of transition of supercharging assistance by the motor 2b is deteriorated. For this reason, when the rotational speed of the motor 2b is low to some extent (here, this is equal to or lower than the predetermined rotational speed), the amount of lubricating oil is set regardless of the driving rotational speed of the motor 2b and the lubricating oil temperature. The rotation resistance increase due to the viscosity of the lubricating oil is suppressed below the fixed amount.

  After the lubricant amount is determined in step 220, the pump 10 is controlled by the controller 6 and the ECU 7 so that the determined lubricant amount is supplied to the turbo unit 2 (step 230). On the other hand, when supercharging assist by the motor 2b is not performed, that is, when step 210 is denied, the amount of lubricating oil is determined based on another map different from the map of FIG. 3 (step 240). ). In this embodiment, the lubricating oil amount is determined based on the rotational speed of the motor 2b and the lubricating oil temperature in this case as well, but the absolute amount is smaller than the supercharging assist by the motor 2b. When the motor 2b rotates only with exhaust energy and when further supercharging assist is performed with electric energy, the amount of lubricating oil in the latter case is increased even at the same rotation speed.

  The present invention is not limited to the embodiment described above. For example, in the above-described embodiment, the circulation system of the turbo unit 2 with the motor 2b and the circulation system of the engine 1 are made independent. However, if the amount of circulating oil to the turbo unit 2 can be controlled, the above-described two circulation systems may be integrated (the lubricating oil circulates both systems). In such a case, the lubricating oil on the engine 1 side may be circulated by a mechanical pump using the engine output, and the lubricating oil on the turbo unit 2 side may be circulated by a pump whose circulation amount can be easily adjusted. Further, the circulation of the lubricating oil on the turbo unit 2 side is performed with a pump whose adjustment of the circulation amount is easy only during the driving of the motor 2b, and is performed with a mechanical pump using the engine output while the motor 2b is not driven. May be.

  Alternatively, it is also conceivable to construct the control device of the present invention by providing a mechanical pump using the engine output and a flow rate adjusting mechanism without using the electric pump 10 as in the present embodiment. As the flow rate adjustment mechanism at this time, for example, it is conceivable to use a valve capable of controlling the DUTY ratio for flow rate adjustment. In addition, since the upper limit of the amount of lubricating oil delivered in this case depends on engine output fluctuation, in order to improve this, a lubricating oil sent by a mechanical pump is stored in a predetermined high pressure state. Things may be provided. Further, in the above-described embodiment, the turbo rotation speed is detected by the motor 2b. However, in order to detect the turbo rotation speed (that is, the rotation speed of the motor 2b), a sensor may be installed and detected by this sensor.

It is a block diagram which shows the structure of the internal combustion engine (engine) which has one Embodiment of the control apparatus of this invention. It is a flowchart which shows lubricating oil amount control by one Embodiment of the control apparatus of this invention. It is a map which shows the relationship between lubricating oil amount, motor rotation speed, and lubricating oil temperature.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Turbo unit (supercharger), 2a ... Turbine / compressor (rotating shaft), 2b ... Motor (electric motor), 2c ... Temperature sensor, 3 ... Intake passage, 4 ... Exhaust passage, 5 ... Battery, 6 ... Controller (control means), 7 ... ECU (control means), 8 ... Oil flow path (lubricating oil supply means), 9 ... Oil pan (lubricating oil supply means), 9 ... Turbo unit (lubricating oil supply means), 10: Pump (lubricating oil supply means).

Claims (2)

A supercharger disposed on an intake passage of an internal combustion engine mounted on a vehicle and driven by a rotary electric motor;
Lubricating oil supply means for supplying lubricating oil in the vicinity of the rotating shaft of the electric motor;
Control means for controlling the supply of lubricating oil by the lubricating oil supply means,
The lubrication control device for a supercharger with an electric motor, wherein the control means increases the supply amount of lubricating oil to the vicinity of the rotary shaft as the rotational speed of the electric motor increases when the electric motor is driven to rotate.   When the control means has the same drive rotational speed of the electric motor, the higher the lubricating oil temperature is, the more lubricant oil is supplied to the vicinity of the rotary shaft, and the rotational speed of the electric motor is not more than a predetermined rotational speed. 2. The lubrication control device for a supercharger with an electric motor according to claim 1, wherein the supply amount is set to a predetermined amount or less regardless of the drive rotational speed and the lubricating oil temperature of the electric motor.

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