JP6551438B2 - Engine timing chain wear amount estimation method, engine timing chain lubrication method, and engine timing chain lubrication device - Google Patents

Description

  The technology disclosed herein relates to an engine timing chain wear amount estimation method, an engine timing chain lubrication method, and an engine timing chain lubrication apparatus.

  Patent Document 1 describes a chain tensioner device that detects that an engine timing chain has been extended. Specifically, this chain tensioner device derives part of the engine oil applied to the plunger to the outside when the plunger protrudes beyond a predetermined amount due to the extension of the timing chain, and reduces the pressure of the derived engine oil. The hydraulic sensor detects it. This makes it possible to determine that the timing chain has been extended. The timing chain elongates due to wear of a pin hole that supports the pin, for example. In the following, when the pin hole of the timing chain is worn, the timing chain is sometimes worn.

JP 2016-38077 A

  It is generally known that the wear of the timing chain has a correlation with the surface pressure between the pins of the timing chain and the speed at which the timing chain travels. The surface pressure is related to the torque generated by the engine, and the higher the torque, the higher the surface pressure. When the surface pressure is high, the timing chain is easily worn. The speed at which the timing chain travels is related to the engine speed, and the higher the engine speed, the higher the speed. The higher the travel speed of the timing chain, the easier it is for the timing chain to wear out. Also, the longer the timing chain travels, the easier it is to wear the timing chain. Therefore, theoretically, when the engine is frequently operated at high load, the wear of the timing chain is likely to progress, and when the engine is frequently operated at high speed, the wear of the timing chain is facilitated Become.

  However, according to the study by the inventors of the present application, it has been newly found that the timing chain is likely to be worn when the engine is operated frequently in the high load and low rotation region.

  The technology disclosed herein has been made in view of such a point, and an object thereof is to accurately estimate the amount of wear of an engine timing chain.

  As mentioned above, the actual wear progress of the timing chain is partly different from the theory, so it can be assumed that factors other than surface pressure and running speed have an influence on the wear of the timing chain. .

  As a result of repeated studies by the inventors of the present application, it has been found that the oil film thickness between the pin of the timing chain and the pin hole changes according to the operating state of the engine. If the oil film becomes thin without sufficient suction of lubricating oil between the pins and the pin holes, the timing chain is prone to wear. If the oil film is thickened by sufficient suction of lubricating oil between the pins and the pin holes, wear of the timing chain is suppressed.

  Here, the oil film thickness between the pin and the pin hole is determined by the amount of lubricating oil drawn between the pin and the pin hole. The lubricating oil is generated by the suction pressure generated between the pin and the pin hole by the relative movement between the pin and the pin hole when the timing chain is traveling (that is, when the suction pressure is negative pressure lower than atmospheric pressure), It is sucked between the pin holes.

  For relative movement between the pin and the pin hole, translational movement in which the pin and the pin hole move relative to each other in the direction orthogonal to the axis of the pin, and bending where the pin and the pin hole rotate relative to each other about the pin axis And exercise. The pins and pin holes translate, for example, as the timing chain travels on the tight or loose side between the sprockets. The pin and the pin hole perform a bending motion, for example, when the timing chain is wound around a sprocket. Therefore, while the timing chain is traveling along a predetermined path, the suction pressure between the pins and the pin holes changes, and the number of revolutions of the engine, the magnitude of the torque generated by the engine, and the torque The suction pressure between the pin and the pin hole fluctuates according to the magnitude of the fluctuation or the like.

  Conventionally, assuming that the oil film thickness between the pin and the pin hole is always constant regardless of the operating state of the engine, the surface pressure between the pin and the pin hole of the timing chain, and the timing chain The timing chain wear was estimated based on factors such as the speed at which the vehicle travels.

  As described above, the inventors of the present invention have high accuracy in timing chain wear by a new method of estimating timing chain wear in consideration of the oil film thickness between the pin and the pin hole during travel of the timing chain. The inventors have found that it can be estimated, and have completed the technique disclosed herein.

  Specifically, the technology disclosed herein provides a timing chain having a pin and a pin hole for supporting the pin, and a supply that supplies lubricating oil to a specific location of the timing chain traveling along a predetermined path. The present invention relates to a method of estimating the amount of wear of the timing chain in an engine equipped with a part.

This estimation method comprises the steps of acquiring the number of revolutions of the engine, acquiring the torque generated by the engine, and causing the pin and the pin hole to move relative to each other when the timing chain is traveling. The step of calculating the suction pressure generated between the pin holes and the number of revolutions of the engine and the torque generated by the engine, and the differential pressure between the calculated suction pressure and the atmospheric pressure, Using the step of calculating the suction amount of the lubricating oil drawn between the pins of the timing chain and the pin hole, the calculated suction amount, and the previously set calculation formula , the suction amount is large when the suction amount is large And estimating the amount of wear of the timing chain if the amount of wear of the timing chain is small and the amount of suction is small .

  According to this configuration, the suction pressure generated between the pin and the pin hole during traveling of the timing chain is calculated based on the engine speed and the torque generated by the engine.

  The oil film thickness between the pin and the pin hole varies depending on the differential pressure between the suction pressure and the atmospheric pressure. That is, if the differential pressure is large, the amount of lubricating oil sucked between the pins and the pin holes increases, so the oil film becomes thick. If the differential pressure is small, the amount of lubricating oil drawn between the pins and the pin holes is reduced, so the oil film becomes thinner. Therefore, the amount of lubricating oil sucked between the pin and the pin hole is calculated based on the differential pressure between the suction pressure and the atmospheric pressure, and the calculated amount of suction is used to calculate the wear amount of the timing chain (in other words, By estimating the wear amount of the pin hole), the wear amount of the timing chain can be estimated in consideration of the oil film thickness between the pin and the pin hole when the timing chain is running. Becomes higher.

  The estimation method includes the step of acquiring the supply pressure of the lubricant supplied by the supply unit to the specific portion of the timing chain, and the step of calculating the suction amount is performed by specifying the lubricant to be supplied At the location, the suction amount is computed based on the differential pressure between the computed suction pressure and the supply pressure of the lubricating oil, and at a location other than the specific location, the differential pressure between the computed suction pressure and the atmospheric pressure The suction amount may be calculated based on the above.

  The supply unit supplies the lubricating oil at a specific place in the travel route of the timing chain. At certain locations, lubricating oil is likely to be drawn between the pins and the pin holes. That is, the pressure of the lubricating oil at locations other than the specific location is the same as the atmospheric pressure. On the other hand, the pressure of the lubricating oil at the specific location corresponds to the supply pressure of the supply unit, and is higher than the pressure of the lubricating oil at locations other than the specific location.

  Therefore, the supply pressure of the lubricating oil is acquired, and the suction amount of the lubricating oil is calculated based on the differential pressure between the suction pressure generated between the pin and the pin hole and the supply pressure of the lubricating oil at a specific location. In the places other than the specific place, the suction amount is calculated based on the differential pressure between the suction pressure and the atmospheric pressure. As a result, the oil film thickness between the pin and the pin hole when the timing chain is running can be estimated more accurately, and as a result, the wear of the timing chain can be estimated with higher accuracy. Is possible.

  The step of calculating the suction amount may be performed such that the suction amount increases as the supply pressure of the lubricating oil increases.

  Since the amount of lubricating oil sucked between the pin and the pin hole is proportional to the differential pressure between the lubricating oil supply pressure and the suction pressure, the higher the lubricating oil supply pressure, the larger the amount of lubricating oil suctioned. The oil film thickness between the pin and the pin hole can be accurately estimated. As a result, it is possible to estimate the wear of the timing chain with higher accuracy.

  The step of calculating the suction amount may be performed such that the suction amount increases as the number of revolutions of the engine increases.

  As the engine speed increases, the number of relative movements between the pin and the pin hole per unit time increases. Further, in the configuration in which the supply unit includes the hydraulic pump driven by the engine, the higher the engine speed, the higher the rotational speed of the hydraulic pump, so the amount of lubricating oil supplied increases. Therefore, the oil film thickness between the pin and the pin hole can be accurately estimated by performing calculations so that the amount of suction of the lubricating oil increases as the number of revolutions of the engine increases. As a result, it is possible to estimate the wear of the timing chain with higher accuracy.

  The step of calculating the suction amount may be performed such that the suction amount increases as the torque generated by the engine increases.

  When the torque generated by the engine is high, the amount of torque fluctuation that can occur during operation of the engine increases. When the torque fluctuates greatly, the tension fluctuation of the timing chain occurs, causing a translational movement between the pin and the pin hole, and the amount of the lubricating oil sucked between the pin and the pin hole increases. Therefore, the oil film thickness between the pin and the pin hole can be accurately estimated by calculating so that the suction amount increases as the torque generated by the engine increases. As a result, it is possible to estimate the wear of the timing chain with higher accuracy.

  The step of calculating the amount of wear of the timing chain may be performed such that the amount of wear decreases as the amount of suction increases.

  When the amount of suction is large, the oil film thickness between the pins of the timing chain and the pin hole becomes thick, so that the wear of the timing chain is suppressed. Therefore, the wear of the timing chain can be accurately estimated by calculating so that the amount of wear decreases as the amount of suction increases.

  The method disclosed herein also includes a timing chain having a pin and a pin hole for supporting the pin, and a supply unit that supplies lubricating oil to a specific location of the timing chain traveling along a predetermined path. In another engine, the timing chain is lubricated.

In this lubrication method, the step of acquiring the rotational speed of the engine, the step of acquiring the torque generated by the engine, and the pin and the pin hole move relative to each other when the timing chain travels. The step of calculating the suction pressure generated between the pin holes and the number of revolutions of the engine and the torque generated by the engine, and the differential pressure between the calculated suction pressure and the atmospheric pressure, Using the step of calculating the suction amount of the lubricating oil drawn between the pins of the timing chain and the pin hole, the calculated suction amount, and the previously set calculation formula , the suction amount is large when the suction amount is large and less wear of the timing chain, a step of estimating the wear amount of the timing chain and the suction amount is small is large, the timing chain estimated Based on the amount of wear, and a, a step of the supply unit adjusts the supply amount of the lubricating oil supplied.

  As described above, by calculating the suction amount of the lubricating oil sucked between the pins and the pin holes and estimating the wear amount of the timing chain using the calculated suction amount, the wear amount of the timing chain can be accurately determined. It becomes possible to estimate well.

  Then, the supply amount of the lubricating oil supplied by the supply unit is adjusted based on the estimated wear amount of the timing chain. For example, when it is estimated that the progress of wear of the timing chain is fast, the supply amount of lubricating oil supplied by the supply unit is increased. By so doing, the oil film thickness between the pins and the pin holes can be increased, and the progress of wear on the timing chain can be suppressed.

  The lubrication method includes a step of acquiring a supply pressure of the lubricant supplied to the specific portion of the timing chain by the supply unit, and the step of calculating the suction amount includes the specification of the lubricant supplied At the location, the suction amount is computed based on the differential pressure between the computed suction pressure and the supply pressure of the lubricating oil, and at a location other than the specific location, the differential pressure between the computed suction pressure and the atmospheric pressure The suction amount may be calculated based on the above.

  By doing this, as described above, the oil film thickness between the pins and the pin holes can be more accurately estimated, and the wear of the timing chain can be estimated more accurately.

  As a result, the adjustment of the supply amount of the lubricating oil can also be properly performed, and the progress of the wear of the timing chain can be effectively suppressed.

The device disclosed herein is configured to supply lubricating oil to an engine timing chain having a pin and a pin hole that supports the pin, and to a specific portion of the timing chain that travels along a predetermined path. A lubrication system for a timing chain of an engine comprising: a rotation speed acquisition unit configured to acquire the rotation speed of the engine; and the engine generating based on parameters related to the operation of the engine A torque acquisition unit configured to acquire torque to be performed, and an estimation unit configured to estimate a wear amount of the timing chain, the estimation unit of the engine acquired by the rotation speed acquisition unit Based on the number of revolutions and the torque generated by the engine acquired by the torque acquisition unit, the timing chain travels A suction pressure calculation unit that calculates a suction pressure generated between the pin and the pin hole by the relative movement between the pin and the pin hole, and a suction pressure and an atmospheric pressure calculated by the suction pressure calculation unit based on the pressure difference, a suction amount calculator for calculating an intake quantity of the lubricating oil is sucked into between the pin and the pin hole of the timing chain, and the suction amount of the suction amount calculating unit has calculated in advance There is a wear amount estimation unit that estimates that the wear amount of the timing chain is small when the suction amount is large and the wear amount of the timing chain is large when the suction amount is small using the set computing equation. doing.

  According to this configuration, the wear amount of the timing chain can be accurately estimated as described above.

  The lubricating device may include a control unit configured to adjust a supply amount of the lubricating oil supplied by the supply unit based on the wear amount of the timing chain estimated by the estimation unit. .

  According to this configuration, it is possible to appropriately adjust the supply amount of the lubricating oil in accordance with the accurately estimated timing chain wear state. As a result, the progress of wear of the timing chain can be effectively suppressed.

  The lubricating device includes a supply pressure obtaining unit configured to obtain a supply pressure of the lubricating oil supplied by the supply unit to the specific portion of the timing chain, and the suction amount calculation unit is configured to receive the lubricating oil In the specific location to be supplied, the suction amount is calculated based on the differential pressure between the suction pressure calculated by the suction pressure calculation unit and the supply pressure of the lubricant acquired by the supply pressure acquisition unit, and In places other than the specific place, the suction amount may be calculated based on the differential pressure between the suction pressure and the atmospheric pressure calculated by the suction pressure calculation unit.

  In this way, the oil film thickness between the pin and the pin hole can be estimated more accurately at each position of the timing chain, and as a result, the wear of the timing chain can be estimated with higher accuracy. can do.

  The suction amount calculation unit may calculate such that the suction amount increases as the supply pressure of the lubricating oil increases.

  Thereby, the oil film thickness between a pin and a pin hole can be estimated correctly.

  The suction amount calculation unit may calculate so that the suction amount increases as the number of revolutions of the engine increases.

  Thereby, the oil film thickness between the pin and the pin hole when the timing chain is running can be accurately estimated.

  The suction amount calculation unit may calculate such that the suction amount increases as the torque generated by the engine increases.

  Thereby, the oil film thickness between the pin and the pin hole when the timing chain is running can be accurately estimated.

  The wear amount estimation unit may perform calculation so that the wear amount decreases as the suction amount increases.

  Thereby, the wear amount of the timing chain can be accurately estimated.

  As described above, according to the method for estimating the amount of wear on the timing chain of the engine, the method for lubricating the timing chain of the engine, and the timing chain lubrication device for the engine, the amount of wear on the timing chain can be estimated accurately.

FIG. 1 is a conceptual diagram illustrating an engine system. FIG. 2 is a front view of an engine illustrating the configuration of a timing chain system. FIG. 3 is a perspective view showing the structure of the timing chain. FIG. 4 is a block diagram showing a control configuration of the engine system. FIG. 5 is a block diagram showing the configuration of a timing chain wear amount estimation device. FIG. 6 is a diagram for explaining the principle of lubricating oil being sucked between the pin-pin holes of the timing chain. FIG. 7 is a diagram for explaining factors relating to a differential pressure that causes suction of lubricating oil. FIG. 8 is a diagram illustrating the relationship between each parameter and the amount of lubricating oil suction between the pin and the pin hole. FIG. 9 is a flowchart related to estimation of the wear amount of the timing chain. FIG. 10 is a diagram illustrating a comparison between the wear amount of the timing chain estimated based on the conventional theoretical formula and the wear amount estimated by the present estimation method. FIG. 11 is a flowchart relating to the estimation of the wear amount of the timing chain, which is different from FIG. FIG. 12 is a diagram illustrating a map used to estimate the amount of wear of the timing chain.

  Hereinafter, embodiments of the technology disclosed herein will be described in detail based on the drawings. The following description is an example of a timing chain wear amount estimation method, a timing chain lubrication method, and an engine timing chain lubrication device. FIG. 1 illustrates the configuration of the engine system 1.

  The engine system 1 includes an engine 2 configured as a spark ignition internal combustion engine. The engine 2 is a turbocharged engine. Although not shown, the engine 2 is mounted in a so-called horizontal position in a front engine room of a vehicle such as a car. The engine 2 may be installed vertically. A crankshaft 21 that is an output shaft of the engine 2 is connected to drive wheels via a transmission (not shown). The vehicle travels by transmitting the output of the engine 2 to the drive wheels.

  The engine 2 is provided with a cylinder block 22 and a cylinder head 23 mounted on the cylinder block 22, as also shown in FIG. A plurality of cylinders 24 are provided inside the cylinder block 22. In this example, the engine 2 has four cylinders 24. The four cylinders 24 are arranged side by side in a direction perpendicular to the paper surface in FIG. The number of cylinders 24 and the arrangement of the cylinders 24 included in the engine 2 are not limited to a specific number and arrangement.

  Below the cylinder block 22, an oil pan 29 for storing engine oil is attached. The cylinder block 22 divides a crankcase 26 accommodating the crankshaft 21. The engine 2 has a crank angle sensor 211 that detects the rotation speed of the crankshaft 21, that is, the rotation speed of the engine 2. The crank angle sensor 211 constitutes a rotation speed acquisition unit.

  The crankshaft 21 is connected to the piston 27 via a connecting rod 271 (not shown). The piston 27 is inserted in each cylinder 24 so as to be capable of reciprocating. The piston 27, the cylinder head 23 and the cylinder 24 define a combustion chamber 28.

  An intake port 231 is formed in the cylinder head 23 for each cylinder 24. The intake port 231 communicates with the combustion chamber 28. In the intake port 231, an intake valve 31 capable of blocking between the combustion chamber 28 and the intake port 231 is disposed. The intake valve 31 is driven by an intake valve mechanism 32. The intake valve 31 opens and closes the intake port 231 at a predetermined timing.

  An exhaust port 232 is also formed in the cylinder head 23 for each cylinder 24. The exhaust port 232 communicates with the combustion chamber 28. An exhaust valve 33 capable of blocking between the combustion chamber 28 and the exhaust port 232 is disposed in the exhaust port 232. The exhaust valve 33 is driven by an exhaust valve mechanism 34. The exhaust valve 33 opens and closes the exhaust port 232 at a predetermined timing.

  The intake valve operating mechanism 32 and the exhaust valve operating mechanism 34 respectively have an intake camshaft 321 and an exhaust camshaft 341 as shown in FIG. 1 and 2 are reversed from left to right. The intake camshaft 321 and the exhaust camshaft 341 are connected to each other via timing gears 322 and 342. A cam sprocket 343 is attached to the exhaust camshaft 341 coaxially with the exhaust camshaft 341. A crank sprocket 215 is attached to the crankshaft 21. A timing chain 210 is wound between the cam sprocket 343 and the crank sprocket 215.

  The piston 27 reciprocates in the axial direction of the cylinder by the combustion pressure, whereby the crankshaft 21 is rotated via the connecting rod 271. The driving force of the crankshaft 21 is transmitted to the cam sprocket 343 via the crank sprocket 215 and the timing chain 210. Accordingly, the exhaust camshaft 341 rotates in synchronization with the rotation of the crankshaft 21, and the intake camshaft 321 connected via the timing gears 322 and 342 also rotates in synchronization with the rotation of the crankshaft 21. (See arrow in FIG. 2).

  A guide 351 for guiding the timing chain 210 is provided on the tight side of the timing chain 210, that is, on the right side of the drawing in FIG. The guide 351 suppresses flapping of the timing chain 210. The guide 351 extends in the vertical direction along the tension side of the timing chain 210. The guide 351 is fixed to the cylinder head 23 and the cylinder block 22.

  On the loosening side of the timing chain 210, that is, on the left side of the drawing in FIG. 2, a hydraulic tensioner 352 which applies tension to the timing chain 210 and further has a damping function is disposed. The hydraulic tensioner 352 presses the timing chain 210 via the tension arm 353. The tension arm 353 extends in the vertical direction along the loose side of the timing chain 210. An upper end portion of the tension arm 353 is pivotally supported by the cylinder head 23. The hydraulic tensioner 352 is disposed such that the plunger pushes the lower end portion of the tension arm 353 inward of the engine 2.

  An oil jet 36 that supplies lubricating oil to the timing chain 210 is provided at an intermediate portion of the cylinder block 22. The oil jet 36 injects the lubricating oil toward a specific point 361 where the timing chain 210 bites into the crank sprocket 215 as shown by the white arrow. The oil jet 36 constitutes a part of a supply unit that supplies lubricating oil to a specific portion 361 of the timing chain 210.

  Although not shown, an oil pump 37 (see FIG. 4) for supplying lubricating oil to the oil jet 36 is driven by the engine 2. In the configuration example of the engine system 1 shown here, the oil pump 37 is configured as a variable displacement type. The oil pump 37 constitutes a part of the supply unit.

  The timing chain system of the engine 2 is not limited to the configuration shown in FIG.

  As an example, the intake valve operating mechanism 32 is configured to be able to change the phase of the intake camshaft 321, the lift amount of the intake valve 31, and the valve opening period of the intake valve 31. The intake valve mechanism 32 can adopt various known configurations. The intake valve mechanism 32 receives the signal from the engine control unit 7 (see FIG. 4), and changes the phase of the intake camshaft 321, the lift amount of the intake valve 31, and the valve opening period of the intake valve 31.

  For example, the exhaust valve mechanism 34 is configured to be able to change the phase of the exhaust camshaft 341, the lift amount of the exhaust valve 33, and the valve opening period of the exhaust valve 33. The exhaust valve mechanism 34 can adopt various known configurations. The exhaust valve mechanism 34 receives a signal from the engine control unit 7 and changes the phase of the exhaust camshaft 341, the lift amount of the exhaust valve 33, and the valve opening period of the exhaust valve 33.

  An intake passage 51 is connected to the intake port 231. The intake passage 51 guides intake air to the cylinder 24. A throttle valve 511 is interposed in the intake passage 51. The throttle valve 511 is an electric control type. The throttle actuator 512 that receives the control signal output from the engine control unit 7 adjusts the opening degree of the throttle valve 511.

  A compressor 91 of the turbocharger 9 is disposed upstream of the throttle valve 511 in the intake passage 51. When the compressor 91 is operated, intake air is supercharged. An intercooler 513 that cools the air compressed by the compressor 91 is disposed between the throttle valve 511 and the compressor 91.

  In the intake passage 51 downstream of the throttle valve 511, a surge tank 521 and an independent passage 522 branched to each of the four cylinders 24 on the downstream side of the surge tank 521 are provided.

  An air flow sensor 50 is disposed downstream of the compressor 91 in the intake passage 51 to detect the amount of intake air introduced into the cylinder 24 and the temperature of the intake air.

  An exhaust passage 53 is connected to the exhaust port 232. A turbine 92 of the turbocharger 9 is disposed in the exhaust passage 53. The turbine 92 is rotated by the exhaust gas flow, and the rotation of the turbine 92 operates a compressor 91 connected to the turbine 92.

  The exhaust passage 53 is provided with an exhaust bypass passage 531 for flowing exhaust gas by bypassing the turbine 92. A waste gate valve 93 is provided in the exhaust bypass passage 531. The waste gate valve 93 adjusts the flow rate of the exhaust gas flowing through the exhaust bypass passage 531. As the degree of opening of the waste gate valve 93 is larger, the flow rate of the exhaust gas flowing through the exhaust bypass passage 531 increases, and the flow rate flowing through the turbine 92 decreases.

In the exhaust passage 53, downstream of the turbine 92, a first catalytic device 81 and a second catalytic device 82, which are configured to purify the exhaust gas, are disposed. The exhaust passage 53 is also provided with two O ₂ sensors 83 and 84 for detecting the oxygen concentration in the exhaust gas. Each of the O ₂ sensors 83 and 84 outputs a detection signal to the engine control unit 7.

  An injector 41 is attached to the cylinder head 23 for each cylinder 24. The injector 41 is configured to inject fuel (here, gasoline or fuel containing gasoline) directly into the cylinder 24. The configuration of the injector 41 may be any, but may be, for example, a multi-hole injector. The injector 41 injects a predetermined amount of fuel into the cylinder 24 at a predetermined timing in accordance with a fuel injection pulse from the engine control unit 7. In the example of FIG. 1, the injector 41 is attached at a position closer to the intake side than the axis of the cylinder 24. The mounting position of the injector 41 in the cylinder 24 is not limited to the position shown in the figure.

  Further, an ignition plug 42 is attached to the cylinder head 23 for each cylinder 24. The spark plug 42 is mounted on the ceiling surface of the cylinder head 23 so that the electrode is on the axis of the cylinder 24. The spark plug 42 ignites the air-fuel mixture in the combustion chamber 28 by generating a spark in the combustion chamber 28. The spark plug 42 generates a spark at a desired ignition timing based on an ignition signal from the engine control unit 7.

  The engine 2 has a communication portion 64 for returning the blowby gas leaked from the combustion chamber 28 back to the intake passage 51. The communication portion 64 is configured by a hose that allows the crankcase 26 of the engine 2 and the surge tank 521 to communicate with each other. The communication part 64 introduces blow-by gas in the crankcase 26 into the surge tank 521. A PCV (Positive Crankcase Ventilation) valve 65 is attached to the surge tank 521. The communication part 64 is connected to the PCV valve 65. The PCV valve 65 adjusts the flow rate of the blowby gas flowing through the communication portion 64. In this configuration example, the PCV valve 65 is configured as a mechanical type that changes the opening according to the pressure difference between the crankcase 26 and the intake passage 51. The PCV valve 65 may be attached not to the surge tank 521 but to an oil separator (not shown) provided on the side surface of the cylinder block 22 of the engine 2.

  FIG. 4 shows a configuration related to engine control in the engine system 1. The engine system 1 includes an engine control unit 7.

The air flow sensor 50, the O ₂ sensor 83, the O ₂ sensor 84, and the crank angle sensor 211 are connected to the engine control unit 7 and output detection signals to the engine control unit 7.

  A coolant temperature sensor 20 that detects the coolant temperature is attached to the coolant passage of the engine 2 (not shown). The water temperature sensor 20 is also connected to the engine control unit 7 and outputs a detection signal to the engine control unit 7.

  In addition, an accelerator opening degree sensor 212 for detecting the opening degree of the accelerator pedal operated by the driver, a gear stage detection unit 213 for detecting the gear stage of the transmission, and a vehicle speed sensor 214 for detecting the vehicle speed of the vehicle It is connected to the control unit 7 and outputs a detection signal to the engine control unit 7.

  The engine control unit 7 determines the operating state of the engine 2 based on these detection signals, and applies the injector 41, spark plug 42, intake valve mechanism 32, exhaust valve mechanism 34, and throttle actuator 512 to each other. In contrast, a control signal is output.

  The variable displacement oil pump 37 is also connected to the engine control unit 7, and the engine control unit 7 outputs a control signal to the variable displacement oil pump 37. The variable displacement oil pump 37 receives the control signal of the engine control unit 7 and changes the capacity.

  The engine system 1 includes a wear estimation device 10 for estimating wear of the timing chain 210 (see FIG. 5). The wear estimation device 10 is configured by an engine control unit 7.

  Here, the configuration of the timing chain 210 will be briefly described. As shown in FIG. 3, the timing chain 210 is a known endless chain having a plurality of rollers 210a. A plurality of rollers 210a... 210a are configured to be able to mesh with tooth portions t... T formed on the outer peripheral portions of the sprockets 343 and 215 shown virtually in FIG. An outer plate 210b and an inner plate 210c constituting the timing chain 210 are disposed at both axial ends of the rollers 210a ... 210a, and the rollers 210a ... 210a are supported by pins 210d penetrating the outer plate 210b and the inner plate 210c. Ru. The outer plate 210b and the inner plate 210c are provided with pin holes 210e, and the pin holes 210e rotatably support the pins 210d. Engine oil is supplied as lubricating oil in order to suppress wear due to sliding friction between the pin 210d and the pin hole 210e. As the oil film between the pin 210d and the pin hole 210e becomes thinner, the pin hole 210e tends to expand (that is, wear of the pin hole 210e). If the timing chain 210 wears, the chain length will increase.

  The wear estimation device 10 estimates the wear of the timing chain 210 based on the operating state of the engine 2 including the rotational speed of the engine 2, the torque generated by the engine 2, and the operating time of the engine 2. In the wear estimation of the timing chain 210, the wear estimation device 10 takes into consideration the oil film thickness between the pin 210d and the pin hole 210e when the timing chain 210 travels.

  As shown in FIG. 5, the wear estimation apparatus 10 has a calculation unit 101 that calculates the lubricating oil pressure in the vicinity of the pin 210d and the pin hole 210e, and the suction of the lubricating oil between the pin 210d and the pin hole 210e. Using the calculation unit 102 that calculates the differential pressure P, the calculation unit 103 that calculates the suction amount of the lubricating oil sucked between the pin 210d and the pin hole 210e based on the differential pressure P, and the suction amount of the lubricating oil , And an estimation unit 104 for estimating the amount of wear of the timing chain 210.

  Here, estimation of the oil film thickness between the pin 210d and the pin hole 210e of the timing chain 210 by the wear estimation device 10 will be described with reference to the drawings.

  FIG. 6 is an enlarged view of the pin 210 d and the pin hole 210 e of the timing chain 210. The oil film thickness between the pin 210d and the pin hole 210e is determined by the amount of lubricating oil sucked between the pin 210d and the pin hole 210e. The lubricating oil is sucked between the pin 210 d and the pin hole 210 e by the suction pressure generated by the relative movement between the pin 210 d and the pin hole 210 e when the timing chain 210 travels. That is, as shown in FIG. 6, it is assumed that the pin 210d moves relative to the pin hole 210e in the upper right direction of the drawing. With this movement, suction pressure is generated between the pin 210 d and the pin hole 210 e. If the suction pressure is lower than the atmospheric pressure (that is, negative pressure), the lubricating oil flows from the moving source of the pin 210d to the moving destination, as indicated by the thick arrows in FIG. And between the pin holes 210e. If the suction pressure is higher than the atmospheric pressure (that is, positive pressure), the lubricating oil is discharged to the outside from between the pin 210d and the pin hole 210e.

  As shown in FIG. 7, in the relative movement between the pin 210d and the pin hole 210e when the timing chain 210 is traveling, the pin 210d and the pin hole 210e move relative to each other in the direction orthogonal to the axis of the pin 210d. And a bending movement in which the pin 210d and the pin hole 210e rotate relative to each other about the axis of the pin 210d. The pin 210d and the pin hole 210e translate when the timing chain 210 travels on the tight side and the loose side between the crank sprocket 215 and the cam sprocket 343, respectively. Also, the pin 210 d and the pin hole 210 e perform bending motion when the timing chain 210 is wound around the crank sprocket 215 and the cam sprocket 343. Therefore, while the timing chain 210 is traveling along a predetermined route, the suction pressure between the pin 210d and the pin hole 210e fluctuates, and the engine 2 generates high and low engine speeds. The suction pressure between the pin 210d and the pin hole 210e varies depending on the level of torque and the magnitude of torque fluctuation.

The amount of lubricating oil sucked between the pin 210d and the pin hole 210e depends on the magnitude of the differential pressure P. The differential pressure P is determined by the pressure term P _z , the pressure term P _r , and the pressure term P ₀ . As the differential pressure P becomes smaller than 0, the amount of lubricating oil sucked between the pin 210d and the pin hole 210e increases.

The pressure term P ₀ relates to the lubricating oil pressure in the vicinity of the pin 210d and the pin hole 210e. The calculation unit 101 of the wear estimation apparatus 10 calculates the pressure term P ₀ . The lubricating oil pressure is different between a specific portion 361 where the oil jet 36 supplies the lubricating oil to the timing chain 210 and a portion other than the specific portion. The pressure of the lubricating oil at the specific point 361 corresponds to the supply pressure of the oil jet 36. The calculation unit 101 estimates the lubricating oil pressure at the specific point 361 based on the number of rotations of the engine 2 and the capacity of the variable displacement oil pump 37, and the discharge flow rate of the oil jet 36 and a preset map or arithmetic expression Calculate according to The calculation unit 101 configures a supply pressure acquisition unit configured to acquire the supply pressure of the lubricating oil supplied to the specific portion 361 of the timing chain 210. On the other hand, the pressure of the lubricating oil in places other than the specific place 361 corresponds to atmospheric pressure. The calculation unit 101 sets the lubricating oil pressure at locations other than the specific location 361 to atmospheric pressure.

The pressure term _Pz is a pressure term due to relative translation between the pin 210d and the pin hole 210e. The pressure term P _z depends on the traveling speed of the timing chain 210, the tension fluctuation of the timing chain 210, and the clearance. The traveling speed of the timing chain 210 increases as the rotational speed of the engine 2 increases. When the traveling speed of the timing chain 210 is high, the pressure term _Pz decreases. Further, the tension fluctuation of the timing chain 210 increases as the torque generated by the engine 2 increases. When the tension fluctuation of the timing chain 210 is large, the pressure term _Pz becomes small.

Pressure term _{P r} is the pressure term due to the relative bending movement between the pin 210d and pin holes 210e. The pressure term P _r depends on the traveling speed of the timing chain 210, the number of teeth of the crank sprocket 215 and the cam sprocket 343, the chain pitch, and the average tension of the timing chain 210. As described above, the traveling speed of the timing chain 210 increases as the rotational speed of the engine 2 increases. When the running speed of the timing chain 210 is high, pressure term _{P r} decreases.

  Further, the greater the number of teeth of the crank sprocket 215 and the cam sprocket 343, the smaller the bending angle of the timing chain 210 when the pin 210d and the pin hole 210e are relatively bent, and the pin 210d The lubricating oil is less likely to be sucked into the space between the pin holes 210e. Further, the shorter the chain pitch, the smaller the bending angle of the timing chain 210 when the pin 210d and the pin hole 210e are relatively bent, and lubrication between the pin 210d and the pin hole 210e. It becomes difficult for oil to be sucked. Of course, the number of teeth of the sprockets 215 and 343 and the chain pitch do not change during operation of the engine 2.

The calculation unit 102 of the wear estimation device 10 calculates the differential pressure P from the pressure term P ₀ , the pressure term P _z , and the pressure term P _r described above. The calculating part 102 comprises the suction pressure calculating part which calculates the suction pressure which generate | occur | produces between the pin 210d and the pin hole 210e substantially.

The calculation unit 103 of the wear estimation device 10 calculates the suction amount of the lubricating oil sucked between the pin 210 d and the pin hole 210 e according to a previously set map or calculation formula based on the calculated differential pressure P. For example, as shown in the upper diagram of FIG. 8, as the pressure of the lubricating oil increases, the pressure term P ₀ increases and the differential pressure P becomes smaller than 0, so that it is sucked between the pin 210d and the pin hole 210e. The amount of lubricating oil increases. Further, as shown in Figure in Figure 8, as the rotation speed of the engine 2 is high, since the supply pressure of the lubricating oil increases the rotational speed of the variable displacement oil pump 37 becomes higher, the P ₀ is increased As described above, since the pressure term _Pz and the pressure term _Pr become smaller and the differential pressure P becomes smaller than 0, the amount of lubricating oil sucked between the pin 210d and the pin hole 210e increases. Further, as shown in the lower diagram of FIG. 8, as the torque generated by the engine 2 becomes higher, the tension fluctuation of the timing chain 210 becomes larger, so that the pressure term _Pz becomes smaller and the differential pressure P becomes smaller than 0. Therefore, the amount of lubricating oil sucked between the pin 210d and the pin hole 210e increases. The calculation unit 103 constitutes a suction amount calculation unit that calculates the suction amount of the lubricating oil drawn between the pin 210 d and the pin hole 210 e.

  The estimation unit 104 of the wear estimation device 10 is preset based on the operating state of the engine 2 in consideration of the oil film thickness between the pin 210 d and the pin hole 210 e of the timing chain 210 using the calculated suction amount. The wear amount of the timing chain 210 is estimated according to the equation. When the oil film thickness is large, the wear amount of the timing chain 210 can be estimated relatively small. Conversely, when the oil film thickness is thin, the amount of wear of the timing chain 210 is estimated relatively large. The estimation unit 104 configures a wear amount estimation unit that estimates the wear amount of the timing chain 210.

  FIG. 9 is a flowchart showing the procedure for estimating the wear amount of the timing chain 210, which is executed by the engine control unit 7 (that is, the wear estimation device 10). First, at step S91 after the start, the engine control unit 7 reads the operating state of the engine 2. In the following step S92, the computing unit 101 of the wear estimation device 10 estimates the discharge flow rate of the oil jet based on the rotational speed of the engine 2 and the capacity of the variable displacement oil pump 37 as described above.

In step S93, the computing unit 101 of the wear estimation device 10 computes the pressure term P ₀ based on the discharge flow rate of the oil jet estimated in step S92. That is, the computing unit 101 computes the lubricating oil pressure at the specific portion 361, and sets the lubricating oil pressure at other than the specific portion 361 to the atmospheric pressure.

  In step S94, the engine control unit 7 acquires the target torque of the engine 2. The target torque is set based on the accelerator opening detected by the accelerator opening sensor 212, the transmission gear detected by the gear detector 213, and the vehicle speed detected by the vehicle speed sensor 214 (see FIG. 5). . The accelerator opening degree sensor 212, the gear position detection unit 213, and the vehicle speed sensor 214 form part of a torque acquisition unit that acquires the torque generated by the engine 2 based on the parameters related to the operation of the engine 2. In addition, the torque which the engine 2 generate | occur | produces is not limited to acquiring by the method mentioned above. For example, the torque generated by the engine 2 may be acquired based on the fuel injection amount as one of the parameters related to the operation of the engine 2.

In step S95, the calculation unit 102 of the wear estimation device 10 calculates the rotational speed of the engine 2 acquired in step S91 and the target torque of the engine 2 acquired in step S94 (that is, the torque generated by the engine 2). , Suction pressure (that is, P _z + P _r ), and based on the calculated suction pressure and the lubricating oil pressure (that is, P ₀ ) calculated in step S93, the differential pressure P (= P _z + P _r Calculate -P ₀ ).

  In step S96, the computing unit 103 of the wear estimation device 10 computes the suction amount of the lubricating oil sucked between the pin 210d and the pin hole 210e based on the differential pressure P computed in step S95.

  In step S97, the estimation unit 104 of the wear estimation device 10 considers the amount of lubricating oil suction calculated in step S96, and based on the operating state of the engine 2, the wear amount of the timing chain 210 is determined according to a predetermined calculation formula. Estimate The wear estimation device 10 estimates the progress of wear of the timing chain 210 by accumulating the estimated wear amount.

  The wear estimation device 10 can increase the estimation accuracy because the wear amount of the timing chain 210 is estimated in consideration of the oil film thickness between the pin 210 d and the pin hole 210 e when the timing chain 210 travels. become.

  For example, FIG. 10 compares the case where the wear amount of the timing chain 210 is estimated based on the conventional theoretical formula and the case where the wear amount of the timing chain 210 is estimated according to the above-described procedure. FIG. 10 shows an estimation when the engine 2 is operated at a high load and a low rotation frequency.

  In the conventional estimation method, it is assumed that the oil film thickness between the pin 210 d and the pin hole 210 e is always constant regardless of the operating state of the engine 2, and the timing chain based on the operating state of the engine 2 The wear amount of 210 was estimated. When the rotational speed of the engine 2 is low, the traveling speed of the timing chain 210 is low. Therefore, it is estimated that the wear of the timing chain 210 hardly progresses with the conventional estimation method.

  On the other hand, in the estimation method disclosed herein, the oil film thickness between the pin 210d and the pin hole 210e is taken into consideration. If the rotational speed of the engine 2 is low, as apparent from the middle view of FIG. 8, the lubricating oil is less likely to be sucked between the pin 210d and the pin hole 210e, so the oil film becomes thin. Therefore, in the estimation method disclosed herein, it is estimated that the wear of the timing chain 210 proceeds more easily than the estimation amount in the conventional method when the rotation speed of the engine 2 is low. This is consistent with actual trends. Therefore, the new estimation method disclosed herein can accurately estimate the wear of the timing chain 210.

  As shown in FIG. 5, the engine system 1 includes an adjustment device 100 that adjusts the lubrication state of the timing chain 210 based on the estimation result of the wear estimation device 10. The adjusting device 100 constitutes a part of the lubricating device of the timing chain 210 and constitutes a control unit that adjusts the amount of lubricating oil supplied based on the amount of wear of the timing chain 210. Specifically, the adjustment device 100 adjusts the volume of the variable displacement oil pump 37. That is, when the wear estimation device 10 estimates that the wear of the timing chain 210 is likely to progress, the adjustment device 100 corrects the displacement of the variable displacement oil pump 37 so that the supply amount of lubricating oil increases. By doing this, the oil film between the pin 210 d of the timing chain 210 and the pin hole 210 e can be thickened, and the progress of the wear of the timing chain 210 can be suppressed.

( Reference example)
FIG. 11 shows a flowchart according to the reference example. In this reference example, the engine control unit 7 (wear estimation device 10) does not calculate the amount of lubricating oil sucked into the pin 210d and the pin hole 210e and the differential pressure P, for example, a map shown in FIG. The amount of wear of the timing chain 210 is estimated based on the rotational speed of the engine 2 and the torque generated by the engine 2. The map shown in FIG. 12 divides the two-dimensional plane, with the rotational speed of the engine 2 on the horizontal axis and the torque generated by the engine 2 on the vertical axis, into a plurality of areas. The amount of wear of the timing chain 210 in consideration of the oil film thickness between the hole 210e and the hole 210e is determined in advance.

  The wear estimation device 10 reads the operating state of the engine 2 in step S111. Step S111 is the same as step S91. In the following step S112, the wear estimation device 10 acquires a target torque of the engine 2. Step S112 is the same as step S94.

  Then, in step S113, the wear estimation apparatus 10 determines the timing chain 210 based on the rotational speed of the engine 2 acquired in step S111, the target torque of the engine 2 acquired in step S112, and the map shown in FIG. Estimate the amount of wear. The map shown in FIG. 12 takes into consideration the oil film thickness between the pin 210 d and the pin hole 210 e, so that the estimation accuracy of the timing chain 210 can be enhanced as described above.

  The technology disclosed herein is not limited to application to the engine system 1 configured as described above. The technology disclosed herein can be applied to engine systems 1 of various configurations.

1 Engine system 10 Wear estimation device (estimation unit)
100 Adjustment device (control unit)
101 Operation Unit (Supply Pressure Acquisition Unit)
102 Calculation unit (suction pressure calculation unit)
103 Operation Unit (Suction Amount Operation Unit)
104 Estimator (Abrasion Estimator)
2 Engine 210d Pin 210e Pin hole 210 Timing chain 211 Crank angle sensor (rotational speed acquisition unit)
212 Accelerator opening sensor (torque acquisition unit)
213 Gear detection unit (torque acquisition unit)
214 Vehicle speed sensor (torque acquisition unit)
36 Oil jet (supply part)
37 Variable displacement oil pump (supply part)
7 Engine control unit

Claims (15)

In an engine comprising a timing chain having a pin and a pin hole for supporting the pin, and a supply unit for supplying lubricating oil to a specific portion of the timing chain traveling along a predetermined path, the timing chain includes: A method of estimating the amount of wear,
Obtaining the number of revolutions of the engine;
Acquiring a torque generated by the engine;
The suction pressure generated between the pin and the pin hole by the relative movement of the pin and the pin hole when the timing chain is running is based on the rotational speed of the engine and the torque generated by the engine. Process of calculating
Calculating a suction amount of the lubricating oil sucked between the pin and the pin hole of the timing chain based on the calculated differential pressure between the suction pressure and the atmospheric pressure;
The amount of wear of the timing chain is small when the amount of suction is large, and it is estimated that the amount of wear of the timing chain is large when the amount of suction is small , using the calculated suction amount and a preset computing equation. And a timing chain wear amount estimating method for an engine comprising the steps.
In the engine timing chain wear amount estimation method according to claim 1,
A step of acquiring a supply pressure of the lubricating oil supplied to the specific part of the timing chain by the supply unit;
In the step of calculating the suction amount, the suction amount is calculated based on a differential pressure between the calculated suction pressure and the supply pressure of the lubricating oil at the specific location to which the lubricating oil is supplied, and the specifying The timing chain wear amount estimation method for an engine according to claim 1, wherein the suction amount is calculated based on a differential pressure between the calculated suction pressure and the atmospheric pressure at a position other than the position. The timing chain wear amount estimation method for an engine according to claim 2,
The step of calculating the suction amount is a timing chain wear amount estimation method for an engine, which calculates so that the suction amount increases as the supply pressure of the lubricating oil increases. The timing chain wear amount estimation method for an engine according to any one of claims 1 to 3,
The step of calculating the suction amount is a timing chain wear amount estimation method of an engine, which calculates so that the suction amount increases as the number of revolutions of the engine increases. The timing chain wear amount estimation method for an engine according to any one of claims 1 to 4,
The step of calculating the suction amount is a timing chain wear amount estimation method for an engine, wherein the suction amount is calculated to increase as the torque generated by the engine increases. In the engine timing chain wear amount estimation method according to any one of claims 1 to 5,
In the step of calculating the wear amount of the timing chain, a timing chain wear amount estimation method of an engine, which is calculated so that the wear amount decreases as the suction amount increases. An engine comprising: a timing chain having a pin and a pin hole for supporting the pin; and a supply unit for supplying a lubricating oil to a specific portion of the timing chain traveling along a predetermined path. How to lubricate,
Obtaining the number of revolutions of the engine;
Acquiring a torque generated by the engine;
The suction pressure generated between the pin and the pin hole by the relative movement of the pin and the pin hole when the timing chain is running is based on the rotational speed of the engine and the torque generated by the engine. Process of calculating
Calculating a suction amount of the lubricating oil sucked between the pin and the pin hole of the timing chain based on the calculated differential pressure between the suction pressure and the atmospheric pressure;
The amount of wear of the timing chain is small when the amount of suction is large, and it is estimated that the amount of wear of the timing chain is large when the amount of suction is small , using the calculated suction amount and a preset computing equation. Process,
Adjusting the amount of supply of the lubricating oil supplied by the supply unit based on the estimated amount of wear of the timing chain.
The engine timing chain lubrication method according to claim 7,
A step of acquiring a supply pressure of the lubricating oil supplied to the specific part of the timing chain by the supply unit;
In the step of calculating the suction amount, the suction amount is calculated based on a differential pressure between the calculated suction pressure and the supply pressure of the lubricating oil at the specific location to which the lubricating oil is supplied, and the specifying In a part other than the part, a method of lubricating an engine timing chain, which calculates the amount of suction based on the calculated differential pressure between the suction pressure and the atmospheric pressure. An engine timing chain having a pin and a pin hole for supporting the pin;
A lubrication system for an engine timing chain, comprising: a supply unit configured to supply lubricating oil to a specific portion of the timing chain traveling along a predetermined path;
A rotational speed acquisition unit configured to acquire the rotational speed of the engine;
A torque acquisition unit configured to acquire torque generated by the engine based on parameters relating to operation of the engine;
An estimation unit configured to estimate the amount of wear of the timing chain,
The estimation unit
Based on the rotation speed of the engine acquired by the rotation speed acquisition unit and the torque generated by the engine acquired by the torque acquisition unit, the pin and the pin hole move relative to each other when the timing chain travels. A suction pressure calculation unit for calculating a suction pressure generated between the pin and the pin hole,
A suction amount calculation unit for calculating a suction amount of the lubricating oil sucked between the pin and the pin hole of the timing chain based on a differential pressure between the suction pressure and the atmospheric pressure calculated by the suction pressure calculation unit; ,
Using the suction amount calculated by the suction amount calculation unit and a calculation formula set in advance , the wear amount of the timing chain is small when the suction amount is large and the wear of the timing chain is small when the suction amount is small A lubrication device for an engine timing chain, comprising: a wear amount estimation unit that estimates that the amount is large . The engine timing chain lubrication device according to claim 9,
An engine timing chain lubrication device comprising: a control unit configured to adjust a supply amount of the lubricating oil supplied by the supply unit based on a wear amount of the timing chain estimated by the estimation unit. The engine timing chain lubrication device according to claim 9 or 10,
A supply pressure acquisition unit configured to acquire the supply pressure of the lubricating oil supplied to the specific part of the timing chain by the supply unit;
The suction amount calculation unit is a differential pressure between the suction pressure calculated by the suction pressure calculation unit and the supply pressure of the lubricating oil acquired by the supply pressure acquisition unit at the specific location to which the lubricating oil is supplied. And calculating the suction amount based on the differential pressure between the suction pressure calculated by the suction pressure calculation unit and the atmospheric pressure at a location other than the specific location. Lubrication device. The lubrication system for an engine timing chain according to claim 11.
A lubrication system for an engine timing chain, wherein the suction amount calculation unit calculates so that the suction amount increases as the supply pressure of the lubricating oil increases. The engine timing chain lubrication device according to any one of claims 9 to 12,
The lubrication system for an engine timing chain, wherein the suction amount calculation unit calculates so that the suction amount increases as the number of revolutions of the engine increases. The engine timing chain lubrication device according to any one of claims 9 to 13,
The lubrication system for an engine timing chain, wherein the suction amount calculation unit calculates so that the suction amount increases as the torque generated by the engine increases. In the lubricating device of the timing chain of the engine according to any one of claims 9 to 14,
The wear amount estimation unit is a lubricating device for an engine timing chain that calculates so that the wear amount decreases as the suction amount increases.

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