JP2019085904A - Abnormality detection device and abnormality detection method - Google Patents

Abstract

To easily detect an abnormality on an outer surface of or around a fuel injection section.SOLUTION: An abnormality detection device detects an abnormality on an outer surface of or around a fuel injection section 6 for injecting liquid fuel into a combustion chamber 20 of an engine. The abnormality detection device includes a temperature measurement section 51 and an abnormality determination section. In the engine, the fuel injection section 6 is fitted into a mounting hole 220 of a cylinder 2. The temperature measurement section 51 includes a temperature sensitive section 511 provided in a clearance between the mounting hole 220 and the fuel injection section 6. In the abnormality determination section, based on a temperature measurement value obtained by the temperature measurement section 51, whether or not an abnormality occurs on the outer surface of or around the fuel injection section 6 is determined.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for detecting an abnormality in the outer surface or the periphery of a fuel injection unit that injects liquid fuel into a combustion chamber of an engine.

  BACKGROUND Conventionally, a fuel injection unit that injects liquid fuel into a combustion chamber of an engine (internal combustion engine) has been used. In addition, it is also performed to detect an abnormality in a fuel injection unit. For example, in Patent Document 1, in a dual fuel injection structure in which liquid fuel and gas fuel are combined and used for an internal combustion engine, combustion gas leaking from a combustion chamber to a gas fuel line in the injection structure is detected by a thermal switch. In some cases, techniques for shutting down the internal combustion engine are disclosed. Further, according to Patent Document 2, in the fuel injection valve (injector) in which the excess fuel among the fuel pressure-fed from the fuel tank is returned to the fuel tank via the return line, the internal leak of the fuel reaching the return line A technique for inferring existence is disclosed. In this method, the temperature of the magnet coil provided inside the fuel injection valve is detected from the on / off ratio of holding current adjustment, and is used to estimate the presence of a leak.

Unexamined-Japanese-Patent No. 5-231199 Japanese Patent Publication No. 2008-520891

  By the way, in the fuel injection unit, liquid fuel is injected from the tip end portion disposed in the combustion chamber, but the liquid fuel may leak from the tip end portion due to a defect or the like inside the fuel injection portion. In this case, the liquid fuel adheres to the outer surface of the tip portion, or the liquid fuel adheres to a portion around the tip portion in the cylinder cover provided with the fuel injection portion, and the burnout of the liquid fuel occurs. Further, in the fuel injection portion inserted into the mounting hole portion of the cylinder cover, a contact portion is provided that contacts the entire inner periphery of the mounting hole portion along the entire circumference, but due to a defect in the contact portion In some cases, a blow through may occur in which the generated combustion gas passes between the contact portion and the inner circumferential surface of the mounting hole. These problems can not be found until the fuel injection unit is removed from the cylinder cover and checked, and if the problem continues, the use of the engine requires extensive repair and replacement of parts. Therefore, there is a need for a novel method of easily detecting an abnormality on the outer surface or the periphery of the fuel injection unit.

  The present invention has been made in view of the above problems, and has as its object to easily detect an abnormality on the outer surface or the periphery of a fuel injection unit.

  The invention according to claim 1 is an abnormality detection device for detecting an abnormality in an outer surface or the periphery of a fuel injection unit that injects liquid fuel into a combustion chamber of an engine, wherein the fuel injection unit in the engine has a cylinder mounting hole And inserted in the space between the mounting hole and the fuel injection part, provided on the outer surface of the fuel injection part, or embedded in the cylinder in the vicinity of the fuel injection part A temperature measurement unit having a temperature sensing unit, and an abnormality determination unit that determines the presence or absence of an abnormality on the outer surface or the periphery of the fuel injection unit based on the temperature measurement value obtained by the temperature measurement unit.

  The invention according to claim 2 is the abnormality detection device according to claim 1, wherein the temperature sensing unit is provided in the vicinity of the tip end portion disposed in the combustion chamber in the fuel injection unit, and the abnormality is The abnormality determined by the determination unit includes the combustion of the liquid fuel attached to the outer surface of the tip or the combustion of the liquid fuel attached to a portion around the tip in the cylinder.

  The invention according to claim 3 is the abnormality detection device according to claim 1 or 2, wherein the fuel injection portion has a contact portion that makes contact with the inner peripheral surface of the mounting hole over the entire circumference. The gap between the mounting hole portion and the fuel injection portion includes a first space continuous with the combustion chamber and a second space discontinuous with the combustion chamber by the contact portion The temperature sensing unit is disposed in the second space, and the abnormality determined by the abnormality determining unit is a blowout in which combustion gas passes between the contact portion and the inner peripheral surface of the mounting hole portion. including.

  The invention according to claim 4 is the abnormality detection device according to any one of claims 1 to 3, further comprising a temperature sensing portion provided in the cylinder at a position separated from the fuel injection portion. The abnormality determination unit further includes a temperature measurement unit, and the abnormality determination unit compares the temperature measurement value obtained by the temperature measurement unit with the temperature measurement value obtained by the other temperature measurement unit to determine the presence or absence of the abnormality. judge.

  The invention according to claim 5 is the abnormality detection device according to claim 4, wherein another fuel injection unit is inserted into another attachment hole of the cylinder, and the other temperature measurement unit A temperature sensing portion is provided on the outer surface of the other fuel injection portion provided in the gap between the other mounting hole portion and the other fuel injection portion, or in the vicinity of the other fuel injection portion And embedded in the cylinder.

  The invention according to claim 6 is the abnormality detection device according to any one of claims 1 to 3, wherein the abnormality determination unit is a temperature measurement value obtained by the temperature measurement unit; The presence or absence of the abnormality is determined based on the load factor.

  The invention according to claim 7 is the abnormality detection device according to any one of claims 1 to 3, wherein the abnormality determination unit is a temperature measurement value obtained by the temperature measurement unit, and the combustion chamber. The presence or absence of the said abnormality is determined based on the temperature of the exhaust_gas | exhaustion exhausted from this.

  The invention according to claim 8 is an abnormality detection method for detecting an abnormality in the outer surface or the periphery of a fuel injection unit that injects liquid fuel into a combustion chamber of an engine, wherein the fuel injection unit in the engine has a cylinder mounting hole And inserted in the space between the mounting hole and the fuel injection part, provided on the outer surface of the fuel injection part, or embedded in the cylinder in the vicinity of the fuel injection part The method includes the steps of obtaining a temperature measurement value by a temperature measurement unit having a temperature sensing unit, and determining the presence or absence of an abnormality on the outer surface or the periphery of the fuel injection unit based on the temperature measurement value.

  According to the present invention, it is possible to easily detect an abnormality on the outer surface or the periphery of the fuel injection unit.

It is a figure showing composition of an engine. It is a sectional view of a cylinder cover. It is a figure which shows the front-end | tip part of a fuel injection part, and the vicinity of an inclination part. It is a sectional view of a fuel injection part. It is a block diagram which shows the structure of an abnormality detection apparatus. It is a figure which shows the flow of operation | movement from which an abnormality detection apparatus detects abnormality. It is a block diagram which shows the other example of an abnormality detection apparatus. It is a block diagram which shows the other example of an abnormality detection apparatus. It is a figure which shows the other example of the attachment position of a temperature sensing part. It is a figure which shows the other example of the attachment position of a temperature sensing part.

  FIG. 1 is a view showing the configuration of an engine 1 according to an embodiment of the present invention. The engine 1 is an internal combustion engine for ships, and is a two-stroke diesel engine using a high pressure liquid fuel. The engine 1 includes a cylinder 2 and a piston 3 provided in the cylinder 2. The piston 3 is movable in the vertical direction in FIG. In addition, the up-down direction of FIG. 1 is not necessarily the gravity direction.

  The cylinder 2 includes a cylindrical cylinder liner 21 and a cylinder cover 22 attached to the top of the cylinder liner 21. The piston 3 includes a thick disk-like piston crown 31 inserted into the cylinder liner 21 and a piston rod 32 having one end connected to the lower surface of the piston crown 31. The other end of the piston rod 32 is connected to a crank mechanism (not shown).

  In the engine 1, a space surrounded by the cylinder liner 21, the cylinder cover 22, the exhaust valve 25 (described later), and the upper surface of the piston crown 31 (that is, the upper surface of the piston 3) is for burning liquid fuel and air. It is a combustion chamber 20. In the vicinity of the lower end portion of the cylinder liner 21, a large number of through holes are circumferentially arranged, and a collection of these through holes is a scavenging port 23 for supplying scavenging air described later into the combustion chamber 20. A scavenging chamber 231 is provided around the scavenging port 23, and the scavenging port 23 communicates with the scavenging pipe 41 via the scavenging chamber 231.

  The cylinder cover 22 is provided with an exhaust port 24 for exhausting the gas in the combustion chamber 20 to the outside of the combustion chamber 20, and the exhaust port 24 is provided with an exhaust valve 25 for opening and closing the exhaust port 24. Gas (hereinafter referred to as “exhaust”) discharged from the combustion chamber 20 via the exhaust port 24 is led to the exhaust pipe 42 via the exhaust passage 241. In the actual engine 1, a plurality of cylinders 2 are provided side by side, and the plurality of cylinders 2 are connected to one scavenging pipe 41 and one exhaust pipe 42. In the preferred engine 1, in the turbocharger (not shown), the intake air (air) taken in from the outside is pressurized using the exhaust gas and supplied into the scavenging air pipe 41 as scavenging air. The cylinder cover 22 is further provided with a plurality of fuel injection parts 6. The fuel injection unit 6 is a fuel injection valve that injects liquid fuel into the combustion chamber 20.

  FIG. 2 is a cross-sectional view of the cylinder cover 22 and shows the vicinity of one fuel injection unit 6. The fuel injection unit 6 includes a main body portion 61, an inclined portion 62, and a tip portion 63. The main body 61 has a substantially cylindrical shape having a substantially constant diameter. The tip portion 63 is disposed on the combustion chamber 20 side, and has a substantially cylindrical shape with a diameter sufficiently smaller than that of the main body portion 61. As described later, the tip portion 63 is an atomizer that injects liquid fuel. The inclined portion 62 is a frusto-conical portion disposed between the main body portion 61 and the tip portion 63, and is continuous with both. The diameter of the inclined portion 62 gradually decreases from the main body portion 61 side toward the tip portion 63.

  The cylinder cover 22 includes a plurality of mounting holes 220 around the exhaust port 24. Each mounting hole 220 penetrates from the upper surface of the cylinder cover 22 to the combustion chamber 20, and one fuel injection portion 6 is inserted into the mounting hole 220. In the fuel injection portion 6, a portion disposed on the outer side of the mounting hole portion 220 (upper surface side of the cylinder cover 22) is fixed to the cylinder cover 22 by a fixing portion (not shown) including a stud, a spring casing and a nut. Ru. The configuration of the fixing portion for fixing the fuel injection portion 6 to the cylinder cover 22 may be arbitrarily changed, and may be realized by, for example, a combination of a stud, a distance pipe and a nut. The mounting hole 220 includes a large diameter portion 221, an intermediate portion 222, and a small diameter portion 223. The large diameter portion 221 surrounds the main body 61 of the fuel injection portion 6 and has a diameter slightly larger than the diameter of the main body 61. The small diameter portion 223 surrounds the tip 63 and has a diameter slightly larger than the diameter of the tip 63. The middle portion 222 surrounds the periphery of the sloped portion 62. The diameter of the intermediate portion 222 gradually decreases from the large diameter portion 221 side toward the small diameter portion 223 in the same manner as the inclined portion 62.

  FIG. 3 is a view showing the vicinity of the tip end portion 63 of the fuel injection unit 6 and the inclined portion 62. As shown in FIG. In a state in which the fuel injection portion 6 is fixed to the cylinder cover 22, only a part of the tip portion 63 of the fuel injection portion 6 is disposed in the combustion chamber 20. A gap is provided between the tip end portion 63 and the inner peripheral surface of the small diameter portion 223 over the entire circumference. A portion to be contacted 224 is provided at a portion of the intermediate portion 222 on the small diameter portion 223 side. In the contacted portion 224, the diameter rapidly decreases toward the small diameter portion 223. A contact portion 621 is provided at a portion on the tip portion 63 side in the inclined portion 62. In the contact portion 621, the diameter decreases sharply toward the tip portion 63. The contact portion 621 of the fuel injection portion 6 contacts the contact portion 224 of the mounting hole 220 over the entire circumference. That is, the surface of the contact portion 621 which contacts each other, and the surface of the contacted portion 224 become an airtight surface. These faces are also called seat faces.

  In the inclined portion 62, a gap is provided between the portion excluding the contact portion 621 and the inner circumferential surface of the intermediate portion 222 (except for the contacted portion 224). Further, a gap is provided between the main body portion 61 and the inner peripheral surface of the large diameter portion 221 along the entire circumference. As described above, the gap between the outer surface of each fuel injection portion 6 and the inner circumferential surface of the mounting hole portion 220 is the first space 225 continuous with the combustion chamber 20 and the contact portion 621 And a second space 226 to be continuous. In the example of FIG. 2, an O-ring 611 is provided in the vicinity of the central portion of the main body section 61 in the longitudinal direction of the fuel injection section 6. The O-ring 611 prevents water and the like from entering the combustion chamber 20 from the outside of the cylinder 2 through the mounting hole 220.

  FIG. 4 is a view showing an internal configuration of the fuel injection unit 6, and shows a cross section in a plane including the central axis J1 of the fuel injection unit 6. As shown in FIG. In FIG. 4, the background of only the movable portion 65 described later is indicated by a broken line. Each component of the fuel injection unit 6 is mainly formed of metal.

  A body flow passage pipe 612 is provided in the main body 61 of the fuel injection unit 6. The body channel pipe 612 is cylindrical around the central axis J1 and extends along the central axis J1. A movable portion 65 is provided at an end of the body flow passage pipe 612 on the tip portion 63 side. The movable portion 65 is also called a spindle. The movable portion 65 has a tubular portion 651 surrounding the end of the trunk channel tube 612. At the end of the cylindrical portion 651 on the tip end 63 side, a lid 652 is provided to close the end. The lid portion 652 is provided with a projecting portion 654 that protrudes to the tip end 63 side.

  A plurality of through holes 653 are provided around the projecting portion 654 in the lid portion 652. The plurality of through holes 653 are arranged circumferentially about the central axis J1. Each through hole 653 communicates the inside and the outside of the cylindrical portion 651. The protrusion 654 extends from the lid 652 to the tip 63. The base 655 of the protrusion 654 disposed on the lid 652 side has a larger diameter than other portions of the protrusion 654. A hollow portion 656 is provided at a portion of the protruding portion 654 opposite to the lid portion 652. A plurality of openings 657 communicating with the inside of the hollow portion 656 are provided in the vicinity of the center of the projecting portion 654 in the direction of the central axis J1. In addition, the distal end surface of the projecting portion 654 is provided with one distal end opening 658 in communication with the inside of the hollow portion 656.

  In the main body section 61, a substantially cylindrical movable section guide 66 is further provided. The movable portion guide 66 surrounds the circumference of the cylindrical portion 651 of the movable portion 65. The inner circumferential surface of the movable portion guide 66 contacts the outer circumferential surface of the cylindrical portion 651. The movable portion guide 66 holds the movable portion 65 movably in the direction of the central axis J1. At the end of the movable portion guide 66 on the tip end 63 side, a guide end 661 whose inner diameter and outer diameter gradually decrease toward the tip end 63 is provided. The inner diameter of the portion of the guide end 661 on the tip 63 side is smaller than the diameter of the base 655 of the protrusion 654. The movable portion 65 is biased toward the tip end portion 63 by an elastic member (for example, a spring) (not shown), and a part of the outer peripheral surface of the base 655 and a part of the inner peripheral surface of the guide end 661 Contact around the circumference. In the following description, in the outer peripheral surface of the base portion 655 and the inner peripheral surface of the guide end portion 661, portions that contact each other are referred to as "contact portion 659" and "contacted portion 662", respectively. The surface of the contact portion 659 and the surface of the contacted portion 662 are also referred to as a sheet surface. In a state where the contact portion 659 of the base 655 and the contacted portion 662 of the guide end 661 are in contact with each other, the central axis J1 is centered between the outer peripheral surface of the base 655 and the inner peripheral surface of the guide end 661. An annular space 67 is formed.

  A substantially cylindrical tip portion main body 631 is provided around the protruding portion 654 of the movable portion 65. The tip end main body 631 surrounds the periphery of a portion on the tip end side of the base portion 655 in the projecting portion 654. The distal end side of the distal end portion main body 631 is closed. A minute gap is provided between a portion of the projecting portion 654 from the vicinity of the contact portion 659 to the plurality of openings 657 and the inner circumferential surface of the tip portion main body 631. On the other hand, the outer peripheral surface of a portion in the vicinity of the tip end of the projecting portion 654 substantially contacts the inner peripheral surface of the tip end portion main body 631. In the vicinity of the tip of the tip end portion main body 631, an injection port 632 is provided. In a state where the contact portion 659 of the base 655 and the contacted portion 662 of the guide end 661 are in contact with each other, the ejection port 632 is closed by the projection 654.

  In the engine 1, liquid fuel such as petroleum fuel is supplied from a fuel supply unit (not shown) to the body flow passage pipe 612 of the fuel injection unit 6, and through the cylindrical portion 651 of the movable portion 65 and the plurality of through holes 653. Thus, the annular space 67 is filled with the liquid fuel. In fact, the flow path from the fuel supply portion to the annular space 67 is filled with the liquid fuel without any gap. At the time of non-injection of liquid fuel in the fuel injection portion 6, the pressure of the liquid fuel in the flow path is equal to or less than a predetermined value, and the contact portion 659 of the base 655 and the contacted portion 662 of the guide end 661 are in contact Is kept.

  At the time of injection of the liquid fuel in the fuel injection unit 6, the pressure of the liquid fuel in the flow passage is increased by the fuel supply unit. As a result, the pressure in the annular space 67 becomes high, and the movable portion 65 moves to the opposite side to the tip portion 63, and the contact portion 659 of the base 655 separates from the contacted portion 662 of the guide end 661. The liquid fuel in the annular space 67 flows into the tip end main body 631 and reaches the hollow portion 656 through the plurality of openings 657 in the projecting portion 654. At this time, the tip end of the projecting portion 654 is disposed closer to the movable portion guide 66 than the injection port 632, and the injection port 632 is open. The liquid fuel in the hollow portion 656 flows out from the tip opening 658 and is injected into the combustion chamber 20 from the injection port 632. Actually, the liquid fuel is injected from the fuel injection unit 6 into the combustion chamber 20 in synchronization with the vertical movement of the piston 3 in FIG. 1.

  FIG. 5 is a block diagram showing the configuration of the abnormality detection device 5 provided in the engine 1. The abnormality detection device 5 detects an abnormality on the outer surface or the periphery of each fuel injection unit 6. The abnormality detection device 5 includes a plurality of temperature measurement units 51 and an abnormality determination unit 52. The plurality of temperature measurement units 51 are provided for each of the plurality of fuel injection units 6 (see FIG. 1). Although two temperature measurement units 51 are provided in FIG. 5, three or more temperature measurement units 51 may be provided.

  Each temperature measurement unit 51 includes a temperature sensing unit 511 and a temperature calculation unit 512. The temperature sensing unit 511 is, for example, a temperature measurement contact of a thermocouple. In the temperature measurement unit 51, a temperature sensor other than a thermocouple may be used. As shown in FIG. 3, the temperature sensing portion 511 is provided in a gap between the inner peripheral surface of the mounting hole portion 220 and the outer surface of the fuel injection portion 6. In detail, the temperature sensing portion 511 is attached to the outer surface of the contact portion 621 of the inclined portion 62 outside the contacted portion 224 (opposite to the combustion chamber 20). As a result, in the second space 226 discontinuous with the combustion chamber 20, the temperature sensing portion 511 is disposed in the vicinity of the tip portion 63.

  As described later, since the temperature sensing portion 511 senses a local temperature rise on the outer surface or the periphery of the tip portion 63, the temperature sensing portion 511 can sense the temperature rise, that is, the tip portion It may be disposed in the vicinity of 63. For example, when the distance between the temperature sensing portion 511 and the tip portion 63 is equal to or less than the diameter of the attachment hole 220, it can be considered that the temperature sensing portion 511 is disposed in the vicinity of the tip portion 63. The temperature sensing unit 511 is electrically connected to the temperature calculation unit 512. The temperature calculation unit 512 acquires a temperature measurement value described later, and outputs the temperature measurement value to the abnormality determination unit 52. In the plurality of temperature measurement units 51, one temperature calculation unit 512 may be shared. In addition, the wiring of the temperature sensing unit 511 may be connected to the temperature calculation unit 512 via the inside of the fuel injection unit 6, that is, the space in which the movable unit guide 66 and the like are disposed.

  Here, the abnormality detected by the abnormality detection device 5 will be described. Abnormality in the outer surface or periphery of the fuel injection portion 6 may be caused by the combustion of the liquid fuel attached to the outer surface of the tip portion 63 of the fuel injection portion 6 or the liquid fuel attached to a portion around the tip portion 63 in the cylinder cover 22. Includes combustion. Specifically, when foreign matter bites between the contact portion 659 of the movable portion 65 and the contacted portion 662 of the movable portion guide 66 in the fuel injection portion 6 shown in FIG. At the time of no fuel injection, liquid fuel leaks from the injection port 632. The liquid fuel adheres to the outer surface of the tip portion 63. In addition, it may adhere to a portion around the tip portion 63 in the cylinder cover 22. In the engine 1, in the combustion (explosion) process, the liquid fuel attached to the tip portion 63 or a part of the cylinder cover 22 burns together with the liquid fuel injected into the combustion chamber 20. As a result, the temperature of a portion of the tip portion 63 or the cylinder cover 22 locally rises, and the portion is burned out.

  Leakage of the liquid fuel from the injection port 632 also occurs when so-called contact failure (air tightness failure) occurs such that the contact portion 659 and the contacted portion 662 do not contact uniformly over the entire circumference. For example, when the contact portion 659 or the to-be-contacted portion 662 is partially worn due to insufficient hardness, the contact portion 659 and the to-be-contacted portion 662 do not contact uniformly over the entire circumference. Further, the liquid fuel injected from the one fuel injection portion 6 swirls in the combustion chamber 20, the outer surface of the tip portion 63 of the other fuel injection portion 6 or the tip portion 63 of the cylinder cover 22. It may be led to and attached to surrounding areas. Also in this case, combustion of the liquid fuel occurs on the outer surface of the tip portion 63 or on the corresponding portion of the cylinder cover 22 and burnout occurs. If the use of the engine 1 is continued while the above-described burnout occurs, the extent of the burnout becomes large, and extensive repair and replacement of parts become necessary.

  The abnormality on the outer surface or the periphery of the fuel injection portion 6 includes a blow through where the combustion gas passes between the contact portion 621 of the fuel injection portion 6 and the inner peripheral surface (contacted portion 224) of the mounting hole 220 May be Similar to the leakage of liquid fuel from the injection port 632 described above, foreign matter may bite between the contact portion 621 of the fuel injection portion 6 and the to-be-contacted portion 224 of the attachment hole 220, or the air tightness (for example, The combustion gas generated in the combustion chamber 20 is generated when a decrease in the tightening force of the fuel injection portion 6 to the cylinder cover 22 due to the fixed portion or a contact failure due to uneven tightening force in the circumferential direction is generated. A blow through occurs between the two. When the high temperature combustion gas passes between the contact surface of the contact portion 621 and the contact surface of the contact portion 224, the surface of the sheet is damaged and blowout is more likely to occur. If the engine 1 continues to be used when blow-by occurs, soot (carbon) adheres around the fuel injection unit 6 and it is difficult to remove the fuel injection unit 6 from the cylinder cover 22 during maintenance of the engine 1 It becomes. In addition, heat cracks may occur on the inner peripheral surface of the mounting hole 220 and the outer surface of the fuel injection portion 6 (in particular, corner portions or the like that are likely to become high temperature). In addition, when the pressure in the combustion chamber 20 becomes abnormally high, a blow through may occur.

  Next, detection of the abnormality by the abnormality detection device 5 will be described. FIG. 6 is a diagram showing the flow of an operation in which the abnormality detection device 5 detects an abnormality. In the detection of an abnormality by the abnormality detection device 5, a temperature measurement value in the temperature sensing unit 511 is obtained by the temperature calculation unit 512 (step S11). In the temperature calculation unit 512, the temperature in the temperature sensing unit 511 is always obtained, and in the present processing example, the maximum value of the temperature in a predetermined period (for example, several seconds) is obtained as a temperature measurement value. The temperature measurement may be other than the maximum value. The temperature measurement value in each temperature sensing unit 511 is input to the abnormality determination unit 52.

  The abnormality determination unit 52 determines the presence or absence of an abnormality on the outer surface or the periphery of each fuel injection unit 6 (step S12). In the determination of the presence or absence of abnormality, the temperature measurement value obtained by the temperature measurement unit 51 provided for each fuel injection unit 6 and the temperature measurement value obtained by the other temperature measurement unit 51 are compared. For example, a value obtained by subtracting the temperature measurement value of another temperature measurement unit 51 from the temperature measurement value of the temperature measurement unit 51 of each fuel injection unit 6 is acquired as an evaluation value for the fuel injection unit 6. When temperature measurement values of three or more temperature sensing units 511 are input to abnormality determination unit 52, the temperature measurement values of each temperature measurement unit 51 are the average value of the temperature measurement values of other temperature measurement units 51. It may be compared with etc.

  If the evaluation value of the fuel injection unit 6 is equal to or greater than a predetermined threshold value, it is determined that there is an abnormality on the outer surface or the periphery of the fuel injection unit 6. Then, as indicated by an arrow K1 in FIG. 5, the abnormality determination unit 52 outputs an abnormality detection signal. In the engine 1, the output of the abnormality detection signal K1 from the abnormality determination unit 52 causes, for example, a display provided in the control unit of the engine 1 to display the occurrence of the abnormality and to report it to the operator. The occurrence of an abnormality may be notified by a buzzer or the like. If the occurrence of an abnormality is detected, the fuel injection unit 6 is removed from the cylinder cover 22 and checked at an appropriate time, and repair or component replacement is performed as necessary.

  On the other hand, when the evaluation value is less than the threshold value, it is determined that there is no abnormality, and the abnormality determination unit 52 does not output the abnormality detection signal K1. In the abnormality detection device 5, while the engine 1 is driven, acquisition of a temperature measurement value by the temperature measurement unit 51 (step S11) and determination of the presence or absence of an abnormality (step S12) are constantly repeated.

  As described above, in the abnormality detection device 5, the temperature measurement unit 51 having the temperature sensing unit 511 provided in the gap between the attachment hole 220 and the fuel injection unit 6 is provided. Then, based on the temperature measurement value obtained by the temperature measurement unit 51, the abnormality determination unit 52 determines the presence or absence of an abnormality on the outer surface or the periphery of the fuel injection unit 6. Thus, the abnormality on the outer surface or the periphery of the fuel injection portion 6 can be easily detected without removing the fuel injection portion 6 from the cylinder cover 22. As a result, when an abnormality is detected, early inspection and repair of the fuel injection portion 6 and the like can be performed to avoid serious damage to parts, and the engine 1 can be extended in life. . The temperature measurement unit 51 and the abnormality determination unit 52 can be easily added to the existing engine, and an engine capable of detecting the abnormality can be realized at low cost.

  Further, a temperature sensing portion 511 is provided in the vicinity of the tip portion 63 disposed in the combustion chamber 20 in the fuel injection portion 6. Thus, the abnormality determination unit 52 can detect the combustion of the liquid fuel attached to the outer surface of the tip portion 63 or the combustion of the liquid fuel attached to a portion around the tip portion 63 in the cylinder 2 as an abnormality. As a result, early inspection and repair of the fuel injection portion 6 and the like can be performed to suppress the degree of burnout of the tip portion 63 or the portion of the cylinder 2.

  Furthermore, in the gap between the fuel injection portion 6 and the inner circumferential surface of the mounting hole portion 220, the temperature sensing in the second space 226 discontinuous with the combustion chamber 20 by the contact portion 621 provided in the fuel injection portion 6 The part 511 is arranged. Thus, the blowout through which the combustion gas passes between the contact portion 621 and the inner circumferential surface of the mounting hole portion 220 can be detected as abnormality in the abnormality determination unit 52. As a result, early inspection and repair of the fuel injection part 6 etc. is carried out, and removal of the fuel injection part 6 becomes difficult due to the adhesion of soot, and the inner peripheral surface of the mounting hole 220 and the outer surface of the fuel injection part 6 It is possible to suppress the occurrence of heat cracks in the

  When attention is paid to one temperature measurement unit 51 provided for one fuel injection unit 6, in the abnormality detection device 5, the temperature sensing unit 511 of the other temperature measurement unit 51 is connected to the one fuel injection unit 6. It is provided in the cylinder 2 at a distant position. Then, the abnormality determination unit 52 compares the temperature measurement value obtained by the one temperature measurement unit 51 with the temperature measurement value obtained by the other temperature measurement unit 51 to obtain the one fuel injection unit 6. The presence or absence of an abnormality on the outer surface or the periphery of can be accurately determined on the basis of the actual temperature of the cylinder 2.

  Further, the temperature sensing unit 511 of the other temperature measurement unit 51 is provided for the other fuel injection unit 6. Thus, the presence or absence of an abnormality on the outer surface or the periphery of each fuel injection portion 6 can be determined accurately with reference to the temperature around the other fuel injection portions 6. Note that depending on the design of the abnormality detection device 5, in the cylinder 2, the temperature sensing portion 511 is provided at a position apart from any of the fuel injection portions 6, and the temperature measurement value obtained using the temperature sensing portion 511 is used as a reference. The presence or absence of an abnormality on the outer surface or the periphery of each fuel injection unit 6 may be determined.

  FIG. 7 is a block diagram showing another example of the abnormality detection device 5. The abnormality detection device 5 of FIG. 7 further includes an exhaust temperature acquisition unit 53. The exhaust temperature acquisition unit 53 is provided, for example, in the exhaust passage 241 of FIG. 1 and acquires the temperature of the exhaust. The exhaust temperature acquisition unit 53 may be provided at another position. The temperature of the exhaust gas acquired by the exhaust gas temperature acquisition unit 53 is input to the abnormality determination unit 52. In the abnormality determination unit 52, for example, a plurality of ranges of exhaust temperature, and a threshold of the temperature to be determined as having an abnormality in each of the plurality of ranges (a threshold for the temperature obtained by the temperature measurement unit 51) A table showing the relationship of is prepared in advance. Then, a threshold is obtained from the table using the actual exhaust temperature (for example, the maximum value in a predetermined period), and the fuel injection unit 6 is obtained by comparing the temperature measurement value obtained by the temperature measurement unit 51 with the threshold. The presence or absence of an abnormality on the outer surface or periphery of the As described above, even when the abnormality determination unit 52 determines the presence or absence of an abnormality based on the temperature measurement value obtained by the temperature measurement unit 51 and the temperature of the exhaust gas discharged from the combustion chamber 20, the abnormality is accurate to some extent It can be detected well. The relationship between the temperature of the exhaust gas and the threshold may be prepared by a function or the like.

  FIG. 8 is a block diagram showing another example of the abnormality detection device 5. In the abnormality detection device 5 of FIG. 8, the current load factor of the engine 1 is input to the abnormality determination unit 52 from the engine control unit 10. In the engine 1, for example, the injection amount of liquid fuel by the fuel injection unit 6 in one explosion in the combustion chamber 20 is changed according to the load factor. In the abnormality determination unit 52, for example, a table indicating the relationship between a plurality of ranges of the load factor of the engine 1 and a threshold of the temperature to be determined as having an abnormality in each of the plurality of ranges is prepared in advance. . Then, the load factor of the engine 1 is used to obtain a threshold from the table, and by comparing the temperature measurement value obtained by the temperature measurement unit 51 with the threshold, the presence or absence of an abnormality on the outer surface or the periphery of the fuel injection unit 6 It is judged.

  As described above, the abnormality determination unit 52 accurately detects the abnormality based on the temperature measurement value obtained by the temperature measurement unit 51 and the load factor of the engine 1 to determine the presence or absence of the abnormality. it can. As in the case of FIG. 7, the relationship between the load factor of the engine 1 and the threshold may be prepared by a function or the like.

  Various modifications can be made to the abnormality detection device 5 described above.

  In the cylinder 2, the position at which the temperature sensing unit 511 is attached may be changed as appropriate. For example, as shown in FIG. 9, in the gap between the mounting hole 220 and the fuel injection portion 6, the temperature sensing portion 511 may be attached at a position away from the contact portion 621 of the fuel injection portion 6. In the example of FIG. 9, as in FIG. 3, since the temperature sensing portion 511 is disposed in the second space 226 in the vicinity of the tip 63, the outer surface of the tip 63 and the tip 63 of the cylinder 2 It is possible to detect the combustion of the liquid fuel adhering to the surrounding part of and the blow-by of the combustion gas between the contact portion 621 and the inner peripheral surface of the mounting hole portion 220.

  In FIG. 9, the temperature sensing portion 511 is attached to the inner peripheral surface of the attachment hole 220, but in view of easily attaching and detaching the temperature sensing portion 511 in the cylinder 2, as in the example of FIG. Preferably, the temperature sensing portion 511 is provided on the outer surface of the fuel injection portion 6. Further, the temperature sensing portion 511 and its wiring may be disposed in a groove formed on the outer surface of the fuel injection portion 6, for example, the outer surface of the inclined portion 62, and the groove may be filled with a putty. Also in this case, the temperature sensing unit 511 can be considered to be provided on the outer surface of the fuel injection unit 6, and the temperature sensing unit 511 senses a local temperature rise on the outer surface or the periphery of the fuel injection unit 6. It is possible. In the abnormality detection device 5, when only the blowout of the combustion gas is detected, an arbitrary position in the second space 226 between the mounting hole 220 and the fuel injection part 6, preferably, the contact part 621 and FIG. The temperature sensing unit 511 may be disposed at an arbitrary position between the O-ring 611 and the sensor.

  As shown in FIG. 10, in each temperature measurement unit 51, the temperature sensing unit 511 may be embedded in the cylinder 2 in the vicinity of the fuel injection unit 6. Since the temperature sensing portion 511 senses a local temperature rise on the outer surface or the periphery of the fuel injection portion 6, the temperature sensing portion 511 is a position where the temperature rise can be sensed, that is, the vicinity of the fuel injection portion 6. It should just be arrange | positioned. For example, when the distance between the temperature sensing portion 511 and the fuel injection portion 6 is equal to or less than the diameter of the mounting hole portion 220, it can be considered that the temperature sensing portion 511 is disposed in the vicinity of the fuel injection portion 6 . In FIG. 10, a dedicated hole is formed in the cylinder 2, and the temperature sensing portion 511 is provided in the hole so that the temperature sensing portion 511 is disposed in the vicinity of the fuel injection portion 6. Thereby, based on the temperature measurement value in the temperature sensing portion 511, it becomes possible to easily detect an abnormality on the outer surface or the periphery of the fuel injection portion 6.

  The engine having the abnormality detection device 5 may be used in various applications other than ships, such as a motor vehicle and a motor for power generation.

  The configurations in the above embodiment and each modification may be combined as appropriate as long as no contradiction arises.

DESCRIPTION OF SYMBOLS 1 engine 2 cylinder 5 abnormality detection apparatus 6 fuel injection part 20 combustion chamber 51 temperature measurement part 52 abnormality determination part 63 tip part 220 attachment hole part 224 contacted part 225 1st space 226 2nd space 511 temperature-sensitive part 621 contact Section S11, S12 step

Claims (8)

An abnormality detection device for detecting an abnormality in the outer surface or the periphery of a fuel injection unit that injects liquid fuel into a combustion chamber of an engine, comprising:
In the engine, the fuel injection portion is inserted into a mounting hole portion of a cylinder, and is provided on an outer surface of the fuel injection portion provided in a gap between the mounting hole portion and the fuel injection portion, or A temperature measurement unit having a temperature sensing unit embedded in the cylinder in the vicinity of the fuel injection unit;
An abnormality determination unit that determines the presence or absence of an abnormality on the outer surface or the periphery of the fuel injection unit based on a temperature measurement value obtained by the temperature measurement unit;
An anomaly detection apparatus comprising: The abnormality detection device according to claim 1, wherein
In the fuel injection unit, the temperature sensitive unit is provided in the vicinity of the tip end portion disposed in the combustion chamber,
The abnormality determined by the abnormality determination unit includes the combustion of liquid fuel attached to the outer surface of the tip or the combustion of liquid fuel attached to a portion around the tip in the cylinder. Anomaly detection device. The abnormality detection device according to claim 1 or 2, wherein
The fuel injection portion has a contact portion that contacts the inner peripheral surface of the mounting hole portion over the entire circumference,
The gap between the mounting hole portion and the fuel injection portion includes a first space continuous with the combustion chamber, and a second space discontinuous with the combustion chamber by the contact portion.
The temperature sensing unit is disposed in the second space,
The abnormality detection apparatus characterized in that the abnormality determined by the abnormality determination unit includes a blow through through which a combustion gas passes between the contact portion and the inner peripheral surface of the attachment hole. The abnormality detection device according to any one of claims 1 to 3, wherein
It further comprises another temperature measurement unit having a temperature sensing unit provided in the cylinder at a position separated from the fuel injection unit,
The abnormality determination unit determines the presence or absence of the abnormality by comparing the temperature measurement value obtained by the temperature measurement unit with the temperature measurement value obtained by the other temperature measurement unit. Detection device. The anomaly detection apparatus according to claim 4,
Another fuel injection part is inserted into another mounting hole of the cylinder,
The temperature sensing unit of the other temperature measurement unit is provided on the outer surface of the other fuel injection unit provided in a gap between the other attachment hole and the other fuel injection unit, or An abnormality detection device embedded in the cylinder in the vicinity of another fuel injection unit. The abnormality detection device according to any one of claims 1 to 3, wherein
The abnormality detection apparatus, wherein the abnormality determination unit determines the presence or absence of the abnormality based on a temperature measurement value obtained by the temperature measurement unit and a load factor of the engine. The abnormality detection device according to any one of claims 1 to 3, wherein
The abnormality detection device, wherein the abnormality determination unit determines the presence or absence of the abnormality based on the temperature measurement value obtained by the temperature measurement unit and the temperature of the exhaust gas discharged from the combustion chamber. An anomaly detection method for detecting an anomaly on the outer surface or the periphery of a fuel injection unit that injects liquid fuel into a combustion chamber of an engine.
In the engine, the fuel injection portion is inserted into a mounting hole portion of a cylinder, and is provided on an outer surface of the fuel injection portion provided in a gap between the mounting hole portion and the fuel injection portion, or Obtaining a temperature measurement value by a temperature measurement unit having a temperature sensing unit embedded in the cylinder in the vicinity of the fuel injection unit;
Determining the presence or absence of an abnormality on the outer surface or the periphery of the fuel injection unit based on the temperature measurement value;
An anomaly detection method comprising:

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