JP6436340B2 - Rotation speed detector - Google Patents

Description

  The present invention relates to a rotational speed detection device. In particular, the present invention relates to a rotational speed detection device for a compressor or a turbine.

  2. Description of the Related Art Conventionally, a rotational speed detection device that detects a rotational speed of a compressor or a turbine using a change in a magnetic field is known. In the rotational speed detection device, a detection unit (sensor) including a coil that generates a magnetic field is provided in a casing of a compressor or a turbine. The rotational speed detection device indirectly detects an eddy current generated in the blade when the blade as the detection object passes through the magnetic field. The rotational speed of the compressor or turbine is calculated using this as the blade passage interval. For example, as in Patent Document 1.

  The rotational speed detection device described in Patent Document 1 generates a differential signal voltage from an output signal of an indirectly detected eddy current, and outputs a pulse waveform as a blade detection signal for a time longer than a threshold voltage. That is, the rotational speed detection device described in Patent Document 1 has a pulse waveform until the moment when the blade approaches the detection unit and the distance between the detection unit and the blade changes from a state where the distance is less than or equal to a predetermined value to a separated state. Is output. For this reason, the rotational speed detection device only detects the presence or absence of a blade within a predetermined range from the detection unit, and only calculates the rotational speed from the interval of the pulse waveform.

JP 2008-14656 A

  The present invention has been made in view of such problems, and an object of the present invention is to provide a rotational speed detection device that can determine the state of the compressor or turbine based on the rotational speed and thickness of the blades of the compressor or turbine.

  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 the present invention, there is provided a turbocharger rotation speed detection device in which a detection unit for detecting a blade by a change in inductance of a magnetic field is provided in a casing of a compressor or a turbine, wherein the detection unit does not detect the blade. When switching to the state where the blade is detected, it is considered that the side surface on the rotation direction side of the blade has been detected, and when the detection unit switches from detecting the blade to not detecting the blade, the blade rotates counterclockwise. and all that it has detected the side of the direction, calculates the blade thickness of the blade based on the time from the detection of the side surface of the rotational direction of the one blade before it considers that it has detected the side surface of the counter-rotating direction side, It is determined whether the calculated blade thickness is within a predetermined range, and the side surface on the rotational direction side of the first blade is detected. The time until it is determined that the side surface on the rotational direction side of the second blade is detected, and the side surface on the counter-rotation direction side of the second blade after assuming that the side surface on the counter-rotation direction side of the first blade is detected If the difference or ratio between the time until it is deemed to be detected and the ratio is equal to or greater than a predetermined value, it is determined that an abnormality has occurred in the detection unit .

That is, in the present invention, the first instantaneous rotational speed is calculated from the time from when it is determined that the side surface on the rotational direction side of the first blade is detected until the side surface on the rotational direction side of the second blade is detected. The second instantaneous rotation speed is calculated from the time from when it is determined that the side surface on the counter-rotation direction side of the first blade is detected until the side surface on the counter-rotation direction side of the second blade is detected, A turbocharger self-fault diagnosis is performed from the 1st instantaneous rotation speed and the 2nd instantaneous rotation speed, and the first instantaneous rotation speed and the second instantaneous rotation speed are used to control the opening / closing of the fuel injection valve, intake valve and exhaust valve of the engine. Are transmitted to the engine control device .

That is, in the present invention, an average rotational speed is calculated based on the first instantaneous rotational speed or the second instantaneous rotational speed, and an actual fuel injection amount when fuel is injected based on an arbitrary target injection amount is calculated. In order to do this, a signal about the amount of change in the average rotational speed is transmitted to the engine control device .

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

  According to the present invention, the time from when the side surface on the rotation direction side of the blade passes the detection unit to the time when the side surface on the counter rotation direction side passes the detection unit is detected. Thus, the state of the compressor or turbine can be determined based on the rotational speed and thickness of the blades of the compressor or turbine.

  According to the present invention, the instantaneous rotation speed on the side surface on the rotation direction side of the blade and the instantaneous rotation speed on the basis of the side surface on the anti-rotation direction side are calculated. Thus, the state of the compressor or turbine can be determined based on the rotational speed and thickness of the blades of the compressor or turbine.

  According to the present invention, an abnormality in the shape of the compressor or turbine is detected. Thus, the state of the compressor or turbine can be determined based on the rotational speed and thickness of the blades of the compressor or turbine.

  According to the present invention, the engine is controlled on the basis of the instantaneous rotational speed on the side surface on the rotational direction side of the blade and the instantaneous rotational speed on the basis of the side surface on the counter rotational direction side. As a result, the instantaneous rotational speed is fed back to control the fuel injection amount, the opening of the EGR valve, and the like, thereby accurately responding to changes in the engine load and reducing the variation in exhaust gas. The engine can be controlled.

1 is a cross-sectional view showing a configuration of a turbocharger and a rotation speed detection device according to an embodiment of the present invention. (A) The partial cross section figure which shows the positional relationship of the detection part and braid | blade of the rotational speed detection apparatus which concerns on one Embodiment of this invention. (A) Schematic diagram showing a state in which the blade of the rotational speed detection device according to an embodiment of the present invention does not pass through the detection region of the detection device, and a diagram showing a waveform diagram. (B) Similarly, the blade is the detection region of the detection device. (C) Schematic diagram and waveform diagram showing the state at the moment of entering the arm (c) Schematic diagram and waveform diagram showing the state where the blade passes through the detection region of the detector The figure which shows the schematic and waveform diagram showing the state of the moment which passed the detection area | region of the apparatus. The partial cross section figure which shows the structure of the detection part and the blade in the inspection process of the manufacturing stage of the rotational speed detection device which relates to one execution form of this invention. (A) The schematic diagram showing the concept for calculating the blade thickness and the waveform diagram in the rotational speed detection device according to the embodiment of the present invention, and (b) The schematic diagram showing the concept for calculating the blade pitch. And a waveform diagram. The figure which shows the flowchart showing the control which determines the state of the compressor or turbine in the rotational speed detection apparatus which concerns on one Embodiment of this invention. The figure which shows the flowchart showing the control which determines the blade thickness in the rotational speed detection apparatus which concerns on one Embodiment of this invention. The figure which shows the flowchart showing the control which determines the blade pitch in the rotational speed detection apparatus which concerns on one Embodiment of this invention. The figure which shows the block diagram showing the relationship between the rotational speed detection apparatus which concerns on one Embodiment of this invention, and an engine. The figure which shows the graph showing the valve opening time of a fuel injection valve, and the relationship of injection amount.

  Below, the turbocharger 1 which concerns on one Embodiment of this invention using FIG. 1 is demonstrated.

  As shown in FIG. 1, the turbocharger 1 supplies the engine 20 with intake air that has been compressed and compressed using the exhaust pressure of the exhaust discharged from the engine 20 (see FIG. 10) as a drive source. The turbocharger 1 includes a connecting portion 2, a turbine 6, a compressor 9, and the like.

  The connecting part 2 connects the turbine 6 and the compressor 9. The connecting portion 2 includes a center housing 3, a connecting shaft 4, a bearing 5, and the like. The center housing 3 has a turbine 6 connected to one side and a compressor 9 connected to the other side. The connecting shaft 4 connects a turbine wheel 8 described later and a compressor wheel 11 described later. The connecting shaft 4 is rotatably supported by the center housing 3 via a bearing 5.

  The turbine 6 converts the exhaust pressure of the engine 20 into a rotational driving force. The turbine 6 includes a turbine casing 7, a turbine wheel 8, and the like.

  The turbine casing 7 is a member formed in a bottomed cylindrical shape. One side (bottom side) of the turbine casing 7 is connected to the center housing 3. On one side of the turbine casing 7, an exhaust supply path 7 a is formed in which exhaust gas is supplied to the outer peripheral portion. On the other side (the opposite bottom side) of the turbine casing 7, an exhaust outlet 7 b is formed. A connecting shaft 4 is communicated with the bottom of the turbine casing 7. The exhaust supply path 7 a of the turbine casing 7 is formed so as to communicate with the inside of the turbine casing 7.

  The turbine wheel 8 includes a turbine hub 8a that is a base portion of the turbine wheel 8, and a plurality of turbine blades 8b that are arranged on the outer peripheral surface 8c of the turbine hub 8a at equal intervals in the circumferential direction. The turbine wheel 8 has a turbine hub 8a fixed to the connecting shaft 4 and supported rotatably. The turbine hub 8a has an outer peripheral surface 8c on the side opposite to the connecting shaft 4 that is parallel to the axis of the connecting shaft 4 expanding while curving toward the connecting shaft 4, and the connecting shaft 4 is connected to the end of the connecting shaft 4 side. A flange 8d is formed in a direction perpendicular to the axial center.

  In the turbine wheel 8, the outer periphery of the flange 8 d (expanded diameter side) of the turbine hub 8 a faces the exhaust supply path 7 a of the turbine casing 7, and the reduced diameter side end of the turbine hub 8 a faces the discharge port 7 b of the turbine casing 7. It arrange | positions inside the turbine casing 7 so that it may oppose. That is, the turbine wheel 8 is disposed so that the turbine hub 8a has a diameter decreasing from the exhaust supply side toward the exhaust side. With this configuration, the turbine wheel 8 is rotated by the exhaust pressure of the supplied exhaust gas, and the exhaust gas is guided from the outer peripheral surface 8c of the turbine hub 8a in a direction parallel to the rotation axis and discharged from the discharge port 7b. Let

  The compressor 9 compresses and compresses the supply air of the engine 20. The compressor 9 includes a compressor casing 10 and a compressor wheel 11.

  The compressor casing 10 is a member formed in a cylindrical shape. One side of the compressor casing 10 is connected to the center housing 3 to form a bottom portion. A connecting shaft 4 is communicated with a bottom portion constituted by the center housing 3. On one side (bottom side) of the compressor casing 10, there is formed an intake air discharge passage 10a through which the intake air is discharged to the outer periphery. An intake supply port 10 b is formed on the other side (the opposite bottom side) of the compressor casing 10. An inner wall 10c of the compressor casing 10 is formed so as to increase in diameter toward one side and communicated with the intake air discharge passage 10a.

  The compressor wheel 11 includes a compressor hub 11a that forms the base of the compressor wheel 11, a plurality of full blades 11b (all blades) and splitter blades that are alternately arranged in the circumferential direction on the outer peripheral surface 11d of the compressor hub 11a. 11c (short wing).

  The compressor wheel 11 has a compressor hub 11a fixed to the connecting shaft 4 and is rotatably supported. That is, the compressor wheel 11 is configured to be able to transmit the rotational power from the turbine wheel 8 via the connecting shaft 4. The compressor hub 11a expands in diameter while the outer peripheral surface 11d on the side opposite to the connecting shaft 4 parallel to the axis of the connecting shaft 4 is curved toward the connecting shaft 4, and the connecting shaft 4 is connected to the end of the connecting shaft 4 side. A flange 11e is formed in a direction perpendicular to the axial center. The outer edge shapes of the full blade 11b (all blades) and the splitter blade 11c (short blade) are formed along the inner wall 10c of the compressor casing 10 so as to form a minute gap. Further, the end of the splitter blade 11c on the reduced diameter side is disposed closer to the expanded diameter than the end of the full blade 11b on the reduced diameter side. The compressor wheel 11 may not have the splitter blade 11c.

  In the compressor wheel 11, the outer periphery of the flange 11 e (expansion side) of the compressor hub 11 a faces the intake air discharge passage 10 a of the compressor casing 10, and the end portion on the reduced diameter side of the compressor hub 11 a is the intake inlet of the compressor casing 10. It arrange | positions inside the compressor casing 10 so as to oppose 10b. That is, the compressor wheel 11 is arranged such that the compressor hub 11a expands from the intake supply side to the discharge side. At this time, the interval between the inner wall 10c of the compressor casing 10 and the compressor hub 11a is configured to become narrower as it approaches the intake air discharge passage 10a. That is, in the compressor casing 10, an intake compression passage 11f (see FIGS. 2 and 3) is configured by a space surrounded by the inner wall 10c of the compressor casing 10, the full blade 11b, the splitter blade 11c, and the outer peripheral surface 11d. . In the compressor wheel 11, a first blade BL1 and a second blade BL2 are composed of a full blade 11b or a splitter blade 11c.

  As described above, in the turbocharger 1, when the exhaust gas is supplied to the turbine 6, the turbine wheel 8 is rotated by the exhaust pressure. The compressor wheel 11 connected to the turbine wheel 8 is rotated by the rotational driving force of the turbine wheel 8. The compressor wheel 11 takes in intake air from the intake air supply port 10b. The taken-in intake air is discharged to the intake air discharge passage 10a by the compressor wheel 11 through the intake air compression passage 11f. At this time, the intake air is pressurized and compressed in the intake compression passage 11f, and compression heat is generated.

  Next, the rotational speed detection device 12 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the present embodiment, the rotation speed detection device 12 detects the rotation speed of the compressor 9, but is not limited to this, and may be configured to detect the rotation speed of the turbine.

  As shown in FIG. 1, the rotational speed detection device 12 detects the rotational speed of the compressor 9. The rotation speed detection device 12 includes a detection unit 13, an amplifier 14, a controller 15, and the like. The rotation speed detection device 12 detects the rotation speed of the compressor 9 by detecting the full blade 11 b and the splitter blade 11 c by the detection unit 13.

  The detection unit 13 detects the full blade 11b and the splitter blade 11c. The detection unit 13 is attached by being inserted into an insertion hole 10 d formed on the intake supply port 10 b side of the compressor casing 10. At this time, the detection unit 13 is arranged so that the tip thereof does not protrude from the inner wall 10 c of the compressor casing 10. The detection unit 13 has a coil (not shown) that generates a magnetic field inside a substantially cylindrical casing. When the full blade 11b or the splitter blade 11c passes through the magnetic field generated from the coil, the magnetic flux passes through the full blade 11b or the splitter blade 11c, and an eddy current is generated. The detection unit 13 detects the impedance of the coil that changes due to the eddy current and outputs a detection signal. Thereby, the detection unit 13 determines that the full blade 11b or the splitter blade 11c has passed in the vicinity of the detection unit 13.

  In order to detect the full blade 11b and the splitter blade 11c having different shapes, the detection unit 13 must be arranged so that both the full blade 11b and the splitter blade 11c pass the magnetic field. Therefore, as shown in FIG. 2, the detection unit 13 needs to be arranged so that the region A in which the full blade 11 b and the splitter blade 11 c are close to the compressor casing 10 is included in the magnetic field range. is there.

  The amplifier 14 amplifies the signal from the detection unit 13. The amplifier 14 is connected to the detection unit 13 and acquires a signal from the detection unit 13. The amplifier 14 amplifies the signal from the detection unit 13 and transmits the amplified signal to the controller 15.

  The controller 15 calculates the rotational speed of the compressor 9. The controller 15 stores various programs and data for processing the amplified signal from the amplifier 14. Specifically, the rotational speed detection device 12 may have a configuration in which a CPU, a ROM, a RAM, an HDD, and the like are connected by a bus, or may be configured by a one-chip LSI or the like.

  The controller 15 stores data on the diameter D of a detection region B of the detection unit 13 in which the magnetic flux density from the coil is high enough to generate a detectable eddy current. Further, the controller 15 stores a compressor rotation speed map M1 for calculating a target rotation speed Vt of the compressor 9 based on the rotation speed N of the engine 20 and the output torque Tq. The controller 15 is connected to the amplifier 14 and can acquire an amplified signal from the amplifier 14. The controller 15 calculates the rotation speed of the compressor 9 using the amplified signal from the amplifier 14. The controller 15 is connected to the ECU 25 that is a control device of the engine 20, and can transmit an amplified signal from the amplifier 14 subjected to predetermined processing to the ECU 25 (see FIG. 9).

  Next, the detection mode of the first blade BL1 composed of the full blade 11b or the splitter blade 11c in the detection unit 13 of the rotational speed detection device 12 will be specifically described with reference to FIG. In FIG. 3, a range indicated by a two-dot chain line indicates a detection region B of the detection unit 13. The rotational speed detection device 12 is generated in the full blade 11b or the splitter blade 11c when the distance from the center of the detection region B of the inspection unit 13 is equal to or less than a predetermined radius D / 2. Detect eddy current.

  As shown in FIG. 3A, in the detection unit 13, when the first blade BL1 composed of the full blade 11b or the splitter blade 11c has not entered the detection region B, magnetic flux penetrates the first blade BL1. No eddy currents are generated. Therefore, the detection unit 13 cannot detect a change in the impedance of the coil caused by the influence of the eddy current. Accordingly, the detection unit 13 does not output a detection signal on the assumption that the first blade BL1 does not pass through the vicinity of the detection unit 13. That is, the detection unit 13 is in a state where the first blade BL1 is not detected.

  As shown in FIG. 3B, in the detection unit 13, when the first blade BL1 enters from the counter rotation direction side of the detection region B, the magnetic flux penetrates the first blade BL1 at that moment, and the eddy current flows. Will occur. Therefore, the detection unit 13 detects a change in the impedance of the coil caused by the influence of the eddy current. Accordingly, the detection unit 13 outputs a detection signal at time T11 on the assumption that the side surface on the rotation direction side of the first blade BL1 has reached the vicinity of the detection unit 13. That is, the detection unit 13 switches from a state in which the first blade BL1 is not detected to a state in which the first blade BL1 is detected, and assumes that the side surface on the rotational direction side of the blade is detected at that moment.

  As shown in FIG. 3C, in the detection unit 13, when the first blade BL1 passes through the detection region B, magnetic flux passes through the first blade BL1, and an eddy current is generated. Therefore, the detection unit 13 detects a change in the impedance of the coil caused by the influence of the eddy current. As a result, the detection unit 13 continuously outputs the detection signal on the assumption that the first blade BL1 is passing in the vicinity of the detection unit 13. The detection unit 13 is in a state of detecting the first blade BL1.

  As shown in FIG. 3 (d), in the detection unit 13, when the part of the first blade BL1 that has entered the detection area B last comes off from the rotation direction side of the detection area B, the first blade BL1 Since magnetic flux does not penetrate, eddy current does not occur. Therefore, the detection unit 13 does not detect a change in the impedance of the coil caused by the influence of the eddy current. Accordingly, the detection unit 13 stops outputting the detection signal at time T12 on the assumption that the side surface on the counter-rotation direction side of the first blade BL1 has passed near the detection unit 13. In other words, the detection unit 13 switches from a state in which the first blade BL1 is detected to a state in which the first blade BL1 is not detected, and it is considered that the side surface on the side opposite to the rotation direction of the blade is detected at that moment.

In this way, the rotational speed detection device 12 determines that the side surface of the first blade BL1 on the counter-rotation direction side is the time T11 when the side surface of the first blade BL1 enters the counter-rotation direction side of the detection region B. A detection signal is output until time T12 when the detection region B is removed from the rotation direction side.
Further, the rotational speed detection device 12 determines that the side surface on the counter-rotation direction side of the second blade BL2 is the detection region B from the time T21 when the side surface on the rotation direction side of the second blade BL2 enters the counter-rotation direction side of the detection region B. The detection signal is output until time T22 when the rotation direction is removed (see FIG. 5B). Similarly, the rotational speed detection device 12 includes a side surface on the rotational direction side and a side opposite to the rotational direction side for the third blade BL3, the fourth blade BL4,... Of the compressor wheel 11 composed of the full blade 11b or the splitter blade 11c. Detect with the side of.

  Next, the non-defective product determination of the compressor wheel 11 using the detection signal of the rotation speed detection device 12 in the inspection process at the manufacturing stage of the compressor 9 will be described with reference to FIGS. In addition, although the quality determination of the compressor wheel 11 is performed about all from the 1st blade BL1 formed in the compressor wheel 11 to the nth blade, since it is the same aspect, the 1st blade BL1 and the 2nd blade BL2 The non-defective product determination will be described.

  As shown in FIG. 4, the compressor wheel 11 to be inspected is rotated at a predetermined inspection rotational speed Vc from the outside by a motor M or the like in the inspection process. The rotational speed detection device 12 includes a side surface on the rotational direction side of each of the first blade BL1, the second blade BL2, and the nth blade BL (n) constituting the compressor wheel 11 while the compressor wheel 11 is rotating. It is comprised so that the side surface of a counter-rotation direction side may be detected.

  First, the first blade thickness Th1 that is the thickness of the first blade BL1 of the compressor wheel 11, the second blade thickness Th2 that is the thickness of the second blade BL2, and the thickness of the nth blade BL (n). The non-defective product determination of the first blade thickness Th1 and the second blade thickness Th2 in a certain nth blade thickness Th (n) will be described.

  As shown in FIG. 5A, in the first blade thickness Th1 and second blade thickness Th2 non-defective product determination of the compressor wheel 11, the rotational speed detection device 12 is a side surface of the compressor wheel 11 on the rotational direction side of the first blade BL1. The blade passage time ΔTt1, which is the difference between the time T11 at which detection is performed and the time T12 at which the side surface on the counter-rotation direction side is detected, is calculated. The blade passage time ΔTt1 is the time from when the side surface on the rotation direction side of the first blade BL1 enters the detection region B until the side surface on the counter-rotation direction side passes through the detection region B. That is, the blade passage time ΔTt1 is the time during which the side surface on the rotation direction side of the first blade BL1 passes the diameter D of the detection region B that is a predetermined value indicating the range of the detection region B of the detection unit 13 at the inspection rotation speed Vc. And the time for the first blade BL1 to move by the first blade thickness Th1 at the rotational speed V and the side surface on the counter-rotating direction side to come out of the detection region B. Similarly, the rotational speed detection device 12 calculates the blade passage time ΔTt2 of the second blade BL2.

  The rotational speed detection device 12 acquires the inspection rotational speed Vc of the compressor wheel 11 and calculates and detects the passage distance Lt1 that the first blade BL1 moves in the blade passage time ΔTt1 from the inspection rotational speed Vc and the blade passage time ΔTt1. The first blade thickness Th1 is calculated by subtracting the diameter D of the region B. Similarly, the rotational speed detection device 12 calculates the passing distance Lt2 that the second blade BL2 moves in the blade passing time ΔTt2, and subtracts the diameter D of the detection region B to calculate the second blade thickness Th2.

  The rotational speed detection device 12 determines whether or not the first blade thickness Th1 and the second blade thickness Th2 are within a predetermined range. If one or more of the determined blade thicknesses are not within the predetermined range, the compressor wheel 11 is not used for manufacturing the compressor 9 because there is a blade whose blade thickness is not within the designed dimensional tolerance.

  Next, the rotation direction side pitch P11 and the counter-rotation direction side pitch P12 that are the distance between the first blade BL1 and the second blade BL2 of the compressor wheel 11, and the rotation direction side that is the distance between the second blade BL2 and the third blade. The pitch P21 and the counter-rotation direction side pitch P22,... The rotation direction side pitch P (n-1) 1 and the counter-rotation direction side pitch P (n), which are the distances between the (n-1) th blade and the (n) th blade. -1) The non-defective product determination for the rotation direction side pitch P11 and the counter rotation direction side pitch P12 will be described.

  As shown in FIG. 5B, in the non-defective product determination of the rotation direction side pitch P11 and the counter rotation direction side pitch P12 of the compressor wheel 11, the rotation speed detection device 12 detects the side surface of the first blade BL1 on the rotation direction side. The pitch passage time ΔTp11, which is the difference between the measured time T11 and the time T21 when the side surface on the rotation direction side of the second blade BL2 is detected, is calculated. In addition, the rotational speed detection device 12 passes the pitch, which is the difference between the time T12 when the side surface of the first blade BL1 on the counter-rotation direction side is detected and the time T22 when the side surface of the second blade BL2 on the counter-rotation direction side is detected. Time ΔTp12 is calculated.

  The rotational speed detection device 12 acquires the inspection rotational speed Vc of the compressor wheel 11, and based on the inspection rotational speed Vc and the pitch passage time ΔTp11, the side surface on the rotational direction side of the first blade BL1 and the rotational direction side of the second blade BL2. The rotation direction side pitch P11 with the side surface is calculated, and the counter rotation between the side surface on the counter-rotation direction side of the first blade BL1 and the side surface on the counter-rotation direction side of the second blade BL2 from the inspection rotation speed Vc and the pitch passage time ΔTp12. The direction side pitch P12 is calculated.

  The rotational speed detection device 12 determines whether or not the rotation direction side pitch P11 and the counter rotation direction side pitch P12 are within a predetermined range. If one or more of the determined rotation direction pitches or counter rotation direction side pitches of the blades are not within the predetermined range, the compressor wheel 11 determines that at least one of the blade thickness or blade pitch is not within the designed dimensional tolerance. Not used in the manufacture of. Further, when all of the determined rotation direction side pitch and counter rotation direction side pitch of the blade are within a predetermined range but rotation fluctuation occurs, the compressor wheel 11 is corrected for balance because the rotation balance is not achieved. Yes.

  In this way, in the inspection process at the manufacturing stage of the compressor 9, the rotational speed detection device 12 has the side surface on the counter-rotation direction side after the side surface on the rotation direction side of each blade of the compressor wheel 11 passes the detection unit 13. By detecting the time until it passes through the detector 13, it is used to determine whether or not the blade thickness and blade pitch of each blade of the compressor wheel 11 are formed with dimensions within a predetermined range. Thereby, the state of the compressor 9 or the turbine 6 can be determined based on the rotational speed and thickness of the blades of the compressor 9 or the turbine 6.

  Next, abnormality determination by self-diagnosis diagnosis of the compressor wheel 11 using the detection signal of the rotational speed detection device 12 in the operation stage of the compressor 9 will be described with reference to FIGS. It is assumed that the compressor wheel 11 is formed so that the blade thickness and the blade pitch of each blade are within a predetermined range in the operation stage, and the dimensions are set in the rotational speed detection device 12. In addition, the abnormality determination of the compressor wheel 11 is performed for all of the first blade BL1 to the nth blade BL (n) formed on the compressor wheel 11, but since it is the same mode, the first blade BL1 of the first blade BL1. The abnormality determination for 1 blade thickness Th1 and the rotation direction side pitch P11 and the counter rotation direction side pitch P12 of the first blade BL1 and the second blade BL2 will be described.

  The rotational speed detection device 12 is configured to calculate a first instantaneous rotational speed Vp11 (hereinafter simply referred to as a front first instantaneous moment) at a rotational direction pitch P11 from the pitch passing time ΔTp11 between the first blade BL1 and the second blade BL2 and the rotational direction pitch P11. Rotational speed Vp11) is calculated, and the second instantaneous rotational speed Vp12 (hereinafter simply referred to as the rear second instantaneous rotational speed Vp12) of the counter rotational direction side pitch P12 is calculated from the pitch passage time ΔTp12 and the counter rotational direction side pitch P12. ) Is calculated. Then, the rotational speed detection device 12 determines the abnormality of the compressor 9 and the replacement time of the compressor 9 from the difference (or ratio) between the first instantaneous rotational speed Vp11 and the second instantaneous rotational speed Vp12. The rotational speed detection device 12 calculates the first blade thickness Th1 from the blade passing time ΔTt1 of the first blade BL1, the first instantaneous rotational speed Vp11, and the diameter D of the detection region B, and the blade passing time of the second blade BL2. The second blade thickness Th2 is calculated from ΔTt2, the second instantaneous rotation speed Vp12, and the diameter D of the detection region B. Then, the rotational speed detection device 12 determines the abnormality of the compressor 9 and the replacement time of the compressor 9 from the first blade thickness Th1 and the second blade thickness Th2.

  Next, the abnormality determination of the compressor wheel 11 using the detection signal at the operation stage in the rotational speed detection device 12 according to the present invention will be specifically described. In the present embodiment, the rotational speed detection device 12 is configured such that the time T11 when the side surface on the rotation direction side of the first blade BL1 enters the counter rotation direction side of the detection region B, and the side surface on the counter rotation direction side of the first blade BL1. Is the time T12 when the first blade BL2 is removed from the rotation direction side of the detection region B, the time T21 when the side surface of the second blade BL2 is in the anti-rotation direction side, and the side surface of the second blade BL2 is the anti-rotation direction side. It is assumed that the time T22 from which the detection area B is removed from the rotation direction side is acquired.

  As shown in FIG. 6, in step S110, the rotational speed detection device 12 calculates the pitch passage time ΔTp11 from the detected time T11 and time T21, and calculates the pitch passage time ΔTp12 from the detected time T12 and time T22. Then, the step moves to step S120.

  In step S120, the rotational speed detection device 12 calculates the first instantaneous rotational speed Vp11 from the calculated pitch passage time ΔTp11 and the rotational direction side pitch P11 between the first blade BL1 and the second blade BL2 that are set, The second instantaneous rotation speed Vp12 is calculated from the calculated pitch passage time ΔTp12 and the set counter-rotation direction side pitch P12 between the first blade BL1 and the second blade BL2, and the step proceeds to step S130.

  In step S130, the rotational speed detection device 12 determines whether or not the absolute value of the difference between the calculated first instantaneous rotational speed Vp11 and the second instantaneous rotational speed Vp12 is less than the first reference value δ1. Here, the first reference value δ1 refers to a dimension that is determined to be aged deterioration of the compressor wheel 11. As a result, when it is determined that the absolute value of the difference between the calculated first instantaneous rotational speed Vp11 and the second instantaneous rotational speed Vp12 is less than the first reference value δ1, the rotational speed detection device 12 proceeds to step S200. Let On the other hand, when it is determined that the absolute value of the difference between the calculated first instantaneous rotation speed Vp11 and the second instantaneous rotation speed Vp12 is not less than the first reference value δ1, the rotation speed detection device 12 shifts the step to step S400.

  In step S200, the rotational speed detection device 12 starts blade thickness determination control A, and shifts the step to step 210 (see FIG. 7).

  In step S400, the rotational speed detection device 12 starts blade pitch determination control B, and shifts the step to step 410 (see FIG. 8).

  As shown in FIG. 7, in step S210, the rotational speed detection device 12 calculates the blade passing time ΔTt1 from the detected time T11 and time T12, and the process proceeds to step S220.

  In step S220, the rotational speed detection device 12 calculates the first instantaneous rotational speed Vp11 calculated from the calculated first instantaneous rotational speed Vp11 and the rotation direction side pitch P21 between the second blade BL2 and the third blade calculated in the same manner. The first instantaneous rotational speed Vp (n−1) 1 calculated from the rotational speed Vp21 and the rotational direction pitch P (n−1) 1 between the (n−1) th blade and the nth blade. The average rotational speed V1 is calculated from the above, and the process proceeds to step S230.

  In step S230, the rotational speed detection device 12 calculates the first blade thickness Th1 from the calculated average rotational speed V1 and the blade passing time ΔTt1, and the process proceeds to step S240.

  In step S240, the rotational speed detection device 12 determines whether or not the calculated first blade thickness Th1 is less than the reference thickness σ. Here, the reference thickness σ refers to a design dimensional tolerance of the compressor wheel 11. As a result, when it is determined that the calculated first blade thickness Th1 is less than the reference thickness σ, the rotational speed detection device 12 shifts the step to step S250. On the other hand, when it is determined that the calculated first blade thickness Th1 is not less than the reference thickness σ, the rotational speed detection device 12 shifts the step to step S350.

  In step S250, the rotational speed detection device 12 calculates the target rotational speed Vt of the compressor 9 based on the rotational speed N of the engine 20 and the output torque Tq acquired from the compressor rotational speed map M1, and the target rotational speed of the compressor 9 is calculated. It is determined whether or not the absolute value of the difference between Vt and average rotational speed V1 is less than the allowable speed difference λ. Here, the allowable speed difference λ refers to a speed error that is determined to be aged deterioration of the compressor 9. As a result, when it is determined that the absolute value of the difference between the calculated target rotational speed Vt of the compressor 9 and the average rotational speed V1 is less than the allowable speed difference λ, the rotational speed detection device 12 ends the blade thickness determination control A. The step is shifted to step S110. On the other hand, when it is determined that the absolute value of the difference between the target rotational speed Vt of the compressor 9 and the average rotational speed V1 is not less than the allowable speed difference λ, the rotational speed detection device 12 shifts the step to step S360.

  In step S350, the rotational speed detection device 12 determines that the compressor 9 (turbo 6) is abnormal, outputs a signal to that effect, ends the blade thickness determination control A, and shifts the step to step S110.

  In step S360, the rotational speed detection device 12 determines that it is time to replace the compressor 9 (turbo 6), outputs a signal to that effect, ends the blade thickness determination control A, and shifts the step to step S110. .

  As shown in FIG. 8, in step S410, the rotational speed detection device 12 determines that the absolute value of the difference between the calculated first instantaneous rotational speed Vp11 and the second instantaneous rotational speed Vp12 is greater than or equal to the first reference value δ1 and the second reference value δ2. Judge whether it is less than. Here, the second reference value δ2 refers to a design dimensional tolerance of the compressor wheel 11. As a result, when it is determined that the absolute value of the difference between the calculated first instantaneous rotational speed Vp11 and the second instantaneous rotational speed Vp12 is greater than or equal to the first reference value δ1 and less than the second reference value δ2, the rotational speed detection device 12 The step moves to step S420. On the other hand, when it is determined that the absolute value of the difference between the calculated first instantaneous rotation speed Vp11 and the second instantaneous rotation speed Vp12 is not greater than the first reference value δ1 and less than the second reference value δ2, the rotation speed detection device 12 performs steps. The process proceeds to step S520.

  In step S420, the rotational speed detection device 12 determines that it is time to replace the compressor 9 (turbo 6), outputs a signal to that effect, ends the blade pitch determination control B, and shifts the step to step S110. .

  In step S520, the rotational speed detection device 12 determines that the compressor 9 (turbo 6) is abnormal, outputs a signal to that effect, ends the blade pitch determination control B, and shifts the step to step S110.

  By configuring as described above, the rotational speed detection device 12 calculates the first instantaneous rotational speed Vp11 calculated on the basis of the side surface on the rotational direction side of the first blade BL1 and the second side calculated on the side surface on the counter-rotational direction side. Contrast with the instantaneous rotation speed Vp12 is performed. Thereby, the state of the compressor 9 (turbine 6) can be determined based on the first instantaneous rotational speed Vp11, the second instantaneous rotational speed Vp12, and the first blade thickness Th1 of the compressor 9 (turbine 6).

  Further, by calculating the first instantaneous rotational speed Vp11 and the second instantaneous rotational speed Vp12 of the first blade BL1 and the second blade BL2, which are detection signals in the operation stage in the rotational speed detection device 12 according to the present invention. The speed fluctuation of the compressor 9 can be grasped with higher accuracy. Thereby, in the control of the engine 20, the first instantaneous rotation speed Vp11 and the second instantaneous rotation speed Vp12 are fed back to open the fuel injection valve 21, the intake valve 22, the exhaust valve 23, the EGR valve 24, etc. By performing this control, it is possible to accurately cope with a change in the load of the engine 20 to reduce the variation in exhaust, and to control the engine 20 in an appropriate state according to the load.

  Further, in the compressor 9 having a mass sufficiently smaller than the mass of the engine 20, the average rotational speed V1 of the compressor 9 varies more sensitively than the rotational speed N of the engine 20 when the fuel injection amount varies. Therefore, based on the average rotational speed V1, it is possible to perform an injection amount correction that corrects the fuel injection amount from the rotational speed N of the engine 20 that has fluctuated due to the minute injection of fuel. Specifically, as shown in FIG. 10, the ECU 25 detects the target valve opening time from the average rotational speed V1 acquired from the rotational speed detection device 12 in addition to the rotational speed N of the engine 20 detected by the engine rotational speed detection sensor 16. The actual fuel injection amount Q1 at TQt is calculated. Then, the ECU 25 corrects the valve opening time TQ of the fuel injection valve 21 to the valve opening time TQr so that the actual fuel injection amount Q1 (two-dot chain line in FIG. 10) becomes the target injection amount Qt (solid line in FIG. 10). . Thereby, even in the large engine 20 having a large mass, the injection amount correction by the micro injection can be more accurately performed by using the average rotational speed V1 of the compressor 9.

DESCRIPTION OF SYMBOLS 1 Turbocharger 6 Turbine 7 Turbine casing 9 Compressor 10 Compressor casing 12 Rotational speed detection apparatus 13 Detection part BL1 1st blade

Claims (3)

A turbocharger rotation speed detection device provided with a detection unit for detecting a blade by changing a magnetic field inductance in a compressor or turbine casing,
When the detection unit switches from the state where the blade is not detected to the state where the blade is detected, it is assumed that the side surface on the rotational direction side of the blade has been detected,
Detector is all that detects a counter-rotating direction side surface of the blade when switching the state of not detecting a blade from a state in which to detect the blade,
The blade thickness of the blade is calculated based on the time from when the side surface on the rotation direction side of one blade is detected until the side surface on the side opposite to the rotation direction is detected,
Determine whether the calculated blade thickness is within the specified range,
The time from when it is determined that the side surface on the rotational direction side of the first blade is detected until the time when the side surface on the rotational direction side of the second blade is detected is detected, and the side surface on the non-rotational direction side of the first blade is detected. If the difference or ratio between the time when the second blade is considered to be detected and the time until it is determined that the side surface on the counter-rotation direction side is detected is greater than or equal to a predetermined value, it is determined that an abnormality has occurred in the detection unit. Rotational speed detection device. A first instantaneous rotational speed is calculated from a time from when it is regarded that the side surface on the rotational direction side of the first blade is detected until the side surface on the rotational direction side of the second blade is detected;
A second instantaneous rotational speed is calculated from the time from when it is regarded that the side surface on the counter-rotation direction side of the first blade is detected until the side surface on the counter-rotation direction side of the second blade is detected;
Self-failure diagnosis of the turbocharger is performed from the first instantaneous rotational speed and the second instantaneous rotational speed, and the first instantaneous rotational speed and the second instantaneous rotational speed are used to control the opening / closing of the fuel injection valve, intake valve and exhaust valve of the engine. The rotational speed detection device according to claim 1 , wherein a signal about the speed is transmitted to an engine control device. Calculating an average rotational speed based on the first instantaneous rotational speed or the second instantaneous rotational speed;
The rotational speed detection device according to claim 2 , wherein a signal about a change amount of the average rotational speed is transmitted to an engine control device in order to calculate an actual fuel injection amount when fuel is injected based on an arbitrary target injection amount. .

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