JP2016130712A - Method of processing motor-assisted turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of processing a motor-assisted turbocharger capable of suppressing degradation in supercharging efficiency when the motor-assisted turbocharger is operated.SOLUTION: The motor-assisted turbocharger processing method of irradiating a motor-assisted turbocharger, which has a turbine, a compressor and a motor for driving the rotation of the compressor, with laser to process the turbine and the compressor includes: a step for rotating the motor-assisted turbocharger in a forward direction of air flowing into the compressor and being discharged from the turbine; a step for irradiating the turbine with laser with the use of a laser irradiation device for processing when the motor-assisted turbocharger rotates in the forward direction; a step for rotating the motor-assisted turbocharger in a direction opposite to the forward direction; and a step for irradiating the compressor with laser with the use of the laser irradiation device for processing when the motor-assisted turbocharger rotates in the reverse direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for processing a motor-assisted turbo.

  2. Description of the Related Art Conventionally, there is known a processing method for correcting a balance of a rotating body by irradiating a target to be removed of the rotating body provided in a rotating machine with a laser from a laser irradiation apparatus. For example, Patent Document 1 discloses a processing method for performing balance correction of a rotating body by irradiating a laser from a laser irradiation device onto a portion to be removed of the rotating body while rotating the rotating body. According to the processing method of Patent Document 1, since the processing can be performed while rotating the rotating body, it is not necessary to stop the rotation of the rotating body in order to remove the removal target portion of the rotating body. For this reason, the time required for balance correction can be shortened.

JP 2011-112514 A JP 2012-154671 A JP 2003-302304 A

  By the way, the rotating body provided in the internal combustion engine includes a motor assist turbo in which a motor is attached to a rotating shaft. When the machining method disclosed in Patent Document 1 is adopted for the balance correction of the motor-assisted turbo, an air flow sucked into the wheel is generated depending on the rotation direction. And the molten metal (henceforth sputter | spatter) generate | occur | produced at the time of a process may be sent by the said air flow, and may adhere to an impeller. As a result, the impeller may be damaged, and the supercharging efficiency at the time of operating the motor assist turbo may be lowered.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a motor-assisted turbo machining method capable of suppressing a reduction in supercharging efficiency when the motor-assisted turbo is operated. .

In order to achieve the above object, a first invention is a method for processing a motor-assisted turbo,
A motor-assisted turbo machining method for machining a turbine and the compressor by irradiating a laser from a laser irradiation device to a motor-assisted turbo including a turbine, a compressor, and a motor that rotationally drives the compressor. ,
Supplying air to the motor assist turbo or driving the motor so that the motor assist turbo rotates in a forward direction in which air flows into the compressor and air is discharged from the turbine;
When the motor-assisted turbo is rotating in the forward direction, irradiating the turbine with a laser by the laser irradiation device;
Driving the motor such that the motor-assisted turbo rotates in a direction opposite to the forward direction;
When the motor-assisted turbo is rotating in the reverse direction, irradiating the compressor with laser by the laser irradiation device;
It is characterized by providing.

  According to the first aspect, it is possible to suppress the spatter generated during laser irradiation from adhering to the compressor impeller and the turbine impeller. As a result, it is possible to prevent the supercharging efficiency of the motor assist turbo from decreasing.

1 is a diagram illustrating a balance correction apparatus according to a first embodiment. It is a figure for demonstrating the vibration characteristic of a supercharger and a motor assist turbo. In Embodiment 1, it is sectional drawing of the motor assist turbo by which balance correction | amendment is performed. In Embodiment 1, it is the figure showing about the airflow at the time of the process by the side of a turbine. In Embodiment 1, it is the figure showing about the airflow at the time of the process by the side of a compressor.

Embodiment 1 FIG.
[Configuration of balance correction device]
FIG. 1 is a diagram illustrating a balance correction apparatus according to the first embodiment. FIG. 1 shows a balance correction device 50. The balance correction device 50 is a device that performs cutting by laser irradiation while keeping the supercharger that is the target of balance correction in the final assembled state and rotating the supercharger. As shown in FIG. 1, the turbocharger turbine 12 is fixed to the gantry 14 of the balance correction device 50 by bolts. The supercharger has a structure in which the compressor 10 and the turbine 12 are connected via a rotating shaft. The compressor 10 includes a compressor housing 36 and a compressor impeller 28 stored in the compressor housing 36. Similarly, the turbine 12 includes a turbine housing 34 and a turbine impeller 26 stored in the turbine housing 34. In the present specification, in order to distinguish between a motor-assisted turbo having a motor attached to a rotating shaft, which will be described later, and a supercharger without a motor, the motor as shown in FIG. 1 is not attached. The supercharger is simply referred to as a supercharger.

  In the compressor 10, the compressor impeller 28 is fixed to the rotating shaft by a nut 40. The nut 40 is a part that is cut when the balance of the turbocharger is corrected. An advantage of cutting the nut 40 is that when the cutting position is not appropriate, the nut 40 can be redone by simply replacing the nut 40.

  A driving air supply unit 32 that supplies driving air is attached to the turbine 12. By supplying air to the drive air supply unit 32, the turbine impeller 26 can be rotated. When the turbine impeller 26 rotates, the compressor impeller 28 also rotates through the rotating shaft. In this way, it is possible to perform balance correction of the supercharger while rotating the supercharger.

  On the compressor side, a laser irradiation device 20 is installed. From the laser irradiation apparatus 20, a pulse laser (indicated by reference sign PL in FIG. 1) is irradiated. The removal target portion of the nut 40 is melted or evaporated by the pulse laser emitted from the laser irradiation device 20 and removed.

  Various sensors are attached to the turbocharger in order to measure data when performing balance correction. The rotation sensor 16 is attached to the compressor impeller 28. The rotation sensor 16 detects the rotation angle of the rotation shaft and outputs the detected rotation angle to the arithmetic device 60. The acceleration pickup 18 is attached to the turbine housing 34. The acceleration pickup 18 detects the vibration amount (acceleration) of the turbine housing 34 while the supercharger is rotating, and outputs the detected vibration amount to the arithmetic device 60.

  The arithmetic device 60 calculates vibration data representing the relationship between the rotation angle detected by the rotation sensor 16 and the vibration amount detected by the acceleration pickup 18. Based on the vibration data, the arithmetic device 60 estimates a correction position that is the position of the removal target portion, and further calculates an unbalance amount that is a cutting amount of the removal target portion. The arithmetic device 60 outputs the estimated correction position and the calculated unbalance amount to the control device 70.

  The control device 70 controls the laser irradiation device 20 so that the laser irradiation device 20 irradiates the laser when the correction position estimated by the arithmetic device 60 coincides. Then, the control device 70 controls the laser irradiation device 20 so that the laser irradiation device 20 continues to irradiate the laser until the unbalance amount calculated by the arithmetic device 60 becomes a predetermined value or less.

[Flow of turbocharger balance correction]
Hereinafter, the balance correction flow of the supercharger using the balance correction apparatus of the first embodiment will be described.

  First, air is supplied to the drive air supply unit 32. Thereby, a supercharger rotates.

  Next, the arithmetic device 60 calculates vibration data of the rotating supercharger from the outputs of the rotation sensor 16 and the acceleration pickup 18.

  Next, the arithmetic device 60 estimates the correction position of the rotating supercharger from the calculated vibration data, and calculates the unbalance amount.

  Next, the control device 70 outputs the correction position estimated by the arithmetic device 60 and the calculated unbalance amount as a signal to the laser irradiation device 20. The laser irradiation device 20 performs laser irradiation based on this signal output from the control device 70. Thereby, the balance correction of the supercharger by laser irradiation is started.

  When the balance correction is completed, vibration data is measured again. Then, it is determined whether or not the unbalance amount calculated from the measured vibration data is equal to or less than a predetermined value. When the unbalance amount is equal to or less than the predetermined value, the balance correction is finished. On the other hand, if the unbalance amount is larger than the predetermined value, the calculation device 60 again estimates the correction position and calculates the unbalance amount, and balance correction by laser irradiation is performed. The balance correction is repeated until the unbalance amount becomes a predetermined value or less.

[Motor assist turbo balance correction]
By the way, apart from the supercharger described in FIG. 1, there is a motor assist turbo in which a motor is attached to a rotating shaft. Due to the structure of the motor-assisted turbo, the balance correction cannot be performed completely only by cutting the nut 40 provided in the compressor 10. This will be described below with reference to FIG.

  FIG. 2 is a diagram for explaining vibration characteristics of the supercharger and the motor-assisted turbo. The vertical axis of FIG. 2 shows the magnitude of vibration amplitude (vibration amount), and the horizontal axis shows the rotation speed (frequency) of the supercharger and the motor-assisted turbo. The solid line and the broken line indicate changes in the vibration amount of the motor-assisted turbo that has been balanced by cutting the nut 40 on the compressor side. The alternate long and short dash line indicates the change in the vibration amount of the turbocharger that has been balance-corrected by cutting the nut 40 on the compressor side.

  As indicated by the alternate long and short dash line in FIG. 2, if the turbocharger corrects the balance by cutting the nut 40 on the compressor side, a vibration amount larger than the vibration standard will not occur in the turbo specification rotation region.

  On the other hand, as indicated by the solid line in FIG. 2, when the motor-assisted turbo is balanced on the compressor side so that the primary vibration (star Y) is below the vibration standard, the secondary vibration (star Y ′) vibrates. It becomes larger than the standard. On the other hand, as indicated by the broken line in FIG. 2, when the motor-assisted turbo is subjected to a balance correction so that the secondary vibration (star X ′) is below the vibration standard, the primary vibration (star X) is larger than the vibration standard. Become.

  The phenomenon in which the vibration amount of the motor-assisted turbo exceeds the vibration standard in the turbo use rotation region, as indicated by the solid line and the broken line in FIG. 2, is caused by the fact that the natural vibration period of the motor-assisted turbo is shorter than that of the turbocharger. It is. Here, the reason why the natural vibration of the motor-assisted turbo is generated in a shorter cycle than the vibration of the supercharger is that the rotating shaft is longer than that of the supercharger. This is because it is necessary to attach a motor to the rotating shaft of the motor-assisted turbo, and the rotating shaft is set longer by that amount. Thus, if only the nut 40 on the compressor side of the motor-assisted turbo is cut and the balance is corrected, a vibration amount larger than the vibration standard is generated in the turbo specification rotation region.

  Therefore, in the first embodiment, balance correction is performed not only on the compressor side of the motor assist turbo but also on the turbine side of the motor assist turbo in order to suppress the vibration in the turbo use rotation region of the motor assist turbo within the vibration standard. . By correcting the balance on both sides of the compressor side and the turbine side, the magnitude of the primary vibration and the secondary vibration can be adjusted, and vibration larger than the vibration standard in the turbo use rotation region can be suppressed.

  Hereinafter, balance correction of the motor-assisted turbo in Embodiment 1 will be described with reference to FIG. In FIG. 3, the same components as those described in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 3 is a cross-sectional view of the motor-assisted turbo in which balance correction is performed in the first embodiment. FIG. 3 shows the motor assist turbo 100. The motor assist turbo 100 is provided with a motor 30 for rotating the rotary shaft 24. By energizing the motor 30, the rotating shaft 24 can be rotated in the required direction. Although not shown in FIG. 3, the motor-assisted turbo 100 is fixed by the balance correction device 50 described in FIG. The motor-assisted turbo 100 is cut by laser irradiation in the final assembled state and while rotating, similarly to the supercharger of FIG.

  As shown in FIG. 3, a first laser irradiation device 20A is provided on the compressor side. On the other hand, a second laser irradiation device 20B is provided on the turbine side. The balance correction of the motor-assisted turbo 100 is performed by a pulse laser emitted from each of the first laser irradiation device 20A and the second laser irradiation device 20B. Note that the hub 42 is cut on the turbine side, and the nut 40 is cut on the compressor side.

  Here, when the removal target part is cut by irradiating the motor-assisted turbo 100 with laser, spatter that is a molten metal is generated. When this spatter is caused to flow in the airflow generated by the rotation of the motor-assisted turbo 100, there is a risk of adhering to the compressor impeller 28 and the turbine impeller 26.

  Therefore, in the balance correction of the motor-assisted turbo 100 according to the first embodiment, the motor 30 is controlled so that the direction of the airflow changes between when the laser is irradiated on the turbine side and when the laser is irradiated on the compressor side. By this control, the direction of the generated airflow can be changed by changing the rotation direction of the rotary shaft 24. Hereinafter, the change of the direction of the airflow at the time of balance correction will be described with reference to FIGS. 4 and 5. In FIGS. 4 and 5, the same components as those described in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

[Changing the direction of airflow when balancing the motor-assisted turbo]
FIG. 4 is a diagram illustrating the airflow during processing on the turbine side in the first embodiment. At the time of machining on the turbine side, first, the rotating shaft 24 is rotated by the motor 30. As a result, as indicated by the white arrows in FIG. 4, an airflow is generated in the forward direction in which air flows into the compressor 10 and air is discharged from the turbine 12. When the air flow is generated, the turbine 12 is irradiated with laser by the second laser irradiation device 20 </ b> B, thereby preventing spatter from adhering to the turbine impeller 26.

  FIG. 5 is a diagram illustrating the airflow during processing on the compressor side in the first embodiment. At the time of machining on the compressor side, first, the rotating shaft 24 is rotated by the motor 30 in the direction of rotation opposite to that at the time of turbine side machining. Thereby, as indicated by the white arrow in FIG. 5, an air flow is generated in the reverse direction in which air flows in from the turbine 12 and is discharged from the compressor 10. When the air flow is generated, the compressor 10 is irradiated with a laser beam by the first laser irradiation device 20 </ b> A, so that it is possible to suppress spatter from adhering to the compressor impeller 28.

  According to the balance correction method of the motor-assisted turbo 100 of the first embodiment, it is possible to suppress spatter generated during laser irradiation from adhering to the compressor impeller 28 and the turbine impeller 26. As a result, it is possible to prevent the supercharging efficiency of the motor assist turbo 100 from decreasing.

  In the description of FIG. 4, the rotating shaft 24 is rotated by driving the motor 30, but the present invention is not limited to this. As a method of rotating the rotating shaft 24, the turbine 12 may be rotated by supplying air to the driving air supply unit 32 provided in the turbine 12.

DESCRIPTION OF SYMBOLS 10 Compressor 12 Turbine 16 Rotation sensor 18 Acceleration pick-up 20A 1st laser irradiation apparatus 20B 2nd laser irradiation apparatus 26 Turbine impeller 28 Compressor impeller 30 Motor 32 Drive air supply part 50 Balance correction apparatus 60 Arithmetic apparatus 70 Control apparatus 100 Motor assist turbo

Claims (1)

A motor-assisted turbo machining method for machining a turbine and the compressor by irradiating a laser from a laser irradiation device to a motor-assisted turbo including a turbine, a compressor, and a motor that rotationally drives the compressor. ,
Supplying air to the motor assist turbo or driving the motor so that the motor assist turbo rotates in a forward direction in which air flows into the compressor and air is discharged from the turbine;
When the motor-assisted turbo is rotating in the forward direction, irradiating the turbine with a laser by the laser irradiation device;
Driving the motor such that the motor-assisted turbo rotates in a direction opposite to the forward direction;
When the motor-assisted turbo is rotating in the reverse direction, irradiating the compressor with laser by the laser irradiation device;
A method for machining a motor-assisted turbo, comprising:

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