JP4516393B2 - Supercharger seizure prevention device and control method thereof - Google Patents

Description

The present invention relates to a supercharger seizure prevention device used for a supercharger having a turbine flow rate characteristic variable mechanism and a control method therefor .

Conventionally, exhaust turbine superchargers are frequently used to improve engine output. Since such a supercharger is disposed at a relatively isolated position in the engine lubrication circuit, the lubricating oil is supplied to the supercharger bearing with a delay immediately after the engine is started. Therefore, when the engine is operated at a high rotation speed in a situation where the supply of lubricating oil is not sufficient, there arises a problem that the bearing is seized due to an increase in the rotation speed of the supercharger.
Especially in construction machinery used in cold regions, the engine rotation speed is too high to start engine warm-up promptly despite the fact that the supply of oil is delayed due to the increased viscosity of the lubricating oil. There is a tendency to immediately become a high idle from the start of low temperature, or to fly at a high speed, and such a problem is likely to occur.

In order to solve this problem, first, a three-way valve is provided at the exhaust gas inlet of the turbocharger, and the exhaust gas is supplied to the turbocharger immediately after the engine is started until the lubricating oil is sufficiently distributed to the bearing. It has been proposed to prevent bearing seizure by bypassing from the three-way valve to the exhaust muffler without supplying and preventing the turbocharger from rotating even if the engine is operated at a high speed (Patent Document 1). .
Secondly, immediately after the engine is started, until the lubricant is sufficiently distributed to the bearing, the fuel injection amount is forcibly suppressed to prevent the engine from rotating at a high speed, thereby preventing bearing seizure. It has been proposed (Patent Document 2).

JP-A-4-303128 JP-A-9-228860

However, in Patent Document 1, the three-way valve is provided only for the purpose of preventing the bearing of the supercharger from being seized, the structure is complicated, the purpose of use is limited, and the cost performance is poor.
Further, in Patent Document 2, since the fuel injection amount is inevitably limited when the engine is started, the warm-up operation cannot be performed in a short time, and there is a problem in usability.

An object of the present invention is to provide a supercharger seizure prevention device that can reliably prevent supercharger seizure, and that can improve cost performance and usability, and a control method thereof .

A supercharger seizure prevention device according to claim 1 of the present invention is a supercharger seizure prevention device (70) for preventing seizure of a supercharger (10) having a turbine flow rate characteristic variable mechanism (60). The turbine flow rate characteristic varying mechanism (60) makes the turbine flow rate variable by adjusting the inlet area of the nozzle portion provided in the supercharger (10), and the lubricating circuit (30 of the engine (1)) Pressure detecting means (37) provided between the lubricating oil outlet (2J) of the hydraulic pump (2B) incorporated in the hydraulic pump (2B) and the lubricating oil inlet (10A) of the supercharger (10), and this pressure The turbocharger (10) until the oil pressure (P) at the lubricating oil inlet (10A) is determined to have reached a predetermined pressure (P0) or more upon receiving a signal from the detection means (37). The turbine flow rate characteristic variable mechanism (in the direction in which the rotation of the 0), and the viscosity of the lubricating oil is at least one of the lubricating oil temperature (T), the engine cooling water temperature and the atmospheric temperature, and the lubricating oil type (A1). , A2, A3) and the control means (50) from the position where the pressure detection means (37) detects the pressure (P) to the lubricating oil inlet (10A) of the supercharger (10) The pressure at the lubricant inlet (10A) after reaching the predetermined pressure (P0) by the pressure detecting means (37) is determined by the length (LS) of the oil and the viscosity of the lubricant. determining delay time (DT) until the above, until the delay time (DT) has elapsed, by increasing the inlet area of the nozzle portion, control the system you increase the turbine flow It is characterized by maintaining.

A supercharger seizure preventing device according to claim 2 of the present invention is a supercharger seizure preventing device for preventing seizure of a supercharger having a turbine flow rate characteristic varying mechanism , wherein the turbine flow rate characteristic varying mechanism is provided. (60), a time measuring unit for measuring an elapsed time from the start of the engine, and the turbine in a direction in which the rotation of the supercharger is suppressed until the elapsed time reaches a predetermined arrival time or more. Control means for controlling the flow rate variable mechanism, the viscosity of the lubricating oil is determined by at least one of the oil temperature of the lubricating oil, the water temperature of the engine cooling water and the atmospheric temperature, and the oil type of the lubricating oil, The control means determines the arrival time based on the length from the lubricating oil outlet of the hydraulic pump to the lubricating oil inlet of the supercharger and the viscosity of the lubricating oil .

The supercharger seizure prevention device according to claim 3 of the present invention is the supercharger seizure prevention device according to claim 1 or 2, wherein the turbine flow rate characteristic variable mechanism is a variable in which the nozzle opening degree can be adjusted. It comprises a geometallic turbine nozzle, The said control means is comprised so that rotation of the said supercharger may be suppressed by controlling to the direction which enlarges a nozzle opening degree, It is characterized by the above-mentioned.

A control method of a supercharger seizure prevention device according to claim 4 of the present invention is a control method of a supercharger seizure prevention device for preventing seizure of a supercharger having a turbine flow rate characteristic variable mechanism, After the detected pressure of the pressure detecting means provided between the lubricating oil outlet of the hydraulic pump and the lubricating oil inlet of the supercharger becomes equal to or higher than a predetermined pressure, the control means for controlling the turbine flow rate variable mechanism is lubricated. The viscosity of the lubricating oil is determined based on the oil temperature, and the pressure detection is performed based on the viscosity of the lubricating oil and the length from the position where the pressure detecting means detects the pressure to the lubricating oil inlet of the supercharger. The delay time from when the predetermined pressure is reached by the means until the pressure at the lubricating oil inlet becomes equal to or higher than the predetermined pressure is determined, and by the time measuring unit, the detected pressure of the pressure detecting means becomes equal to or higher than the predetermined pressure. The later elapsed time reaches the delay time Characterized in that it measures up.

A control method for a supercharger seizure prevention device according to claim 5 of the present invention is a control method for a supercharger seizure prevention device for preventing seizure of a supercharger having a turbine flow rate characteristic variable mechanism, The control means for controlling the turbine flow rate variable mechanism determines the viscosity of the lubricating oil based on the oil temperature of the lubricating oil, and the lubricating oil viscosity and the lubricating oil inlet of the turbocharger from the lubricating oil outlet of the hydraulic pump The arrival time is determined based on the length until the time is reached, and the elapsed time is measured until the arrival time is reached by a timer that measures the elapsed time after the engine is started .

In the above, according to the first and second aspects of the invention, the control means causes the lubricating oil to reach the supercharger based on the pressure at the lubricating oil inlet of the supercharger and the elapsed time after the engine is started. If the engine speed is determined to be low, the turbocharger seizure occurs even if the engine speed is increased immediately after starting the engine in order to control the turbine flow rate variable mechanism to prevent the turbocharger speed from increasing. do not do. Accordingly, there is no possibility that the turbocharger will burn, and the engine speed can be increased. Therefore, the time required for the warm-up operation is shortened and the usability is good. In addition, the turbine flow rate variable mechanism and the control means are usually provided as a variable nozzle driving device or a nozzle opening controller for controlling the variable turbo drive in a so-called variable turbo, etc. There is no worry of increasing the complexity and cost.

Note that a wastegate valve generally provided at the exhaust gas inlet of the turbocharger bypasses a part of the exhaust gas when the boost pressure reaches a predetermined pressure or higher, thereby changing the turbine flow rate. Therefore, this wastegate valve is also included in the turbine flow rate variable mechanism according to the present invention. Therefore, you may achieve the objective of this invention by using the control means which can open | release such a waste gate valve large.
Since the wastegate valve is not provided only for preventing the supercharger from being seized, it can be said that the wastegate valve and the three-way valve described in Patent Document 1 are different in configuration in this respect.

Further, as in the first aspect of the invention, a delay time until the lubricating oil actually reaches the lubricating oil inlet is determined, and control is performed so that the rotation of the supercharger is suppressed while the delay time elapses. As a result, seizure of the supercharger can be prevented more reliably.

According to the first and second aspects of the invention, the delay time of the first aspect and the arrival time of the second aspect are the length from the lubricating oil outlet of the hydraulic pump to the lubricating oil inlet of the turbocharger, and pressure detecting means. To the turbocharger lubricating oil inlet, based on parameters such as lubricating oil type, lubricating oil type, lubricating oil temperature, engine coolant temperature, and atmospheric temperature , Those times will be determined more accurately.

According to the invention of claim 3 , since the turbine flow rate characteristic variable mechanism is composed of a variable geometallic turbine nozzle used for a variable turbo, the existing variable turbo can be changed only by changing the control software in the control means. Are also preferably used.

[First Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
FIG. 1 shows an entire diesel engine 1 equipped with a supercharger seizure prevention device 70 according to this embodiment.

  In FIG. 1, a diesel engine 1 is mounted on a hydraulic excavator, a bulldozer, a wheel loader, a dump truck, and other construction machines, and includes an engine main body 2 having a plurality of combustion chambers formed therein, and a combustion chamber. An intake pipe 3 for introducing intake air, an exhaust pipe 4 for discharging exhaust gas to the outside, a cooling mechanism 5 for cooling the diesel engine 1, and a supercharger 10 for compressing intake air for supercharging. A variable nozzle driving device 20 that adjusts the opening degree of the variable nozzle 80 (FIGS. 2 and 3) provided in the supercharger 10, and a lubricating circuit 30 (FIG. 4) that lubricates each driving part of the diesel engine 1. And an engine controller 40 that controls the operation of the diesel engine 1 and a nozzle opening controller 50 (control means) that controls the operation of the variable nozzle drive device 20.

In this embodiment, the turbine flow rate variable mechanism 60 includes the variable nozzle 80 and the variable nozzle driving device 20 of the supercharger 10.
Further, a supercharger seizure prevention device 70 is configured by including a pressure detection means 37 (FIG. 4) provided in the lubrication circuit 30, a nozzle opening controller 50, and a turbine flow rate characteristic variable mechanism 60. That is, the supercharger seizure prevention device 70 has a configuration in which a pressure detection means 37 is added in addition to a nozzle opening controller 50 and a turbine flow rate characteristic variable mechanism 60 that are normally provided as a so-called variable turbo. Is not complicated, and there is no worry of a significant cost increase.

  Among these, the cooling mechanism 5 includes a cooling water pump 8 driven by the power of the diesel engine 1, and the cooling water pumped by the cooling water pump 8 is supplied from the engine body 2, the supercharger 10, an oil cooler, and the like. After cooling a necessary part for cooling, heat is exchanged by a radiator 6 provided in the cooling mechanism 5. An aftercooler 7 for cooling the air compressed by the exhaust turbine supercharger 10 is provided in the middle of the intake pipe 3. The radiator 6 and the aftercooler 7 are cooled by a fan 9 that is rotationally driven.

  The supercharger 10 includes a compressor 11 provided in the middle of the intake pipe 3 and an exhaust turbine 12 provided in the middle of the exhaust pipe 4. As shown in FIG. 2, the compressor 11 has an impeller 13 that compresses intake air from the outside by rotating. The exhaust turbine 12 has a turbine wheel 14 that is rotated by inflowing exhaust gas. The turbine wheel 14 and the impeller 13 are connected by a shaft 15, and the shaft 15 is rotatably supported by a housing 16. At this time, a plurality of variable nozzles 80 along the outer periphery of the turbine wheel 14 are provided on the exhaust turbine 12 side. These variable nozzles 80 adjust the inlet area of the nozzle portion 17 for introducing exhaust gas, and are provided so that the variable nozzle driving device 20 can adjust the inlet area of the nozzle portion.

  2 and 3, specifically, the variable nozzle 80 is a variable geometallic turbine nozzle, and is installed along the outer periphery of the turbine wheel 14 at equal intervals. The plate 18 that forms a part of the nozzle portion 17 is rotatably supported through the plate 18. A connection ring 82 that can rotate on a concentric circle with the shaft 15 is provided inside a region surrounded by the rotation shafts 81 arranged on the circumference. A semi-long hole-shaped engagement hole 83 is formed on the outer periphery of the connection ring 82, and one end of a flat plate-like lever 84 is rotatable and slidable in the engagement hole 83. Is engaged. The other end of each lever 84 is fixed to each rotation shaft 81, and a connecting ring 82 is supported on the rotation shaft 81 via these levers 84. One of the plurality of rotation shafts 81 is a rotation drive shaft 81A that also penetrates the housing 16. Of the levers 84, the one connected to the rotation drive shaft 81A is a drive lever 84A.

  The rotation drive shaft 81A is pivotally supported through the housing 16 so that the rotation portion can be rotated, and the penetration portion is sealed by a simple ring-shaped seal member. Further, the rotational drive shaft 81A has a larger diameter than the other rotational shafts 81 and is formed with high rigidity. Thereby, the rotation drive shaft 81A has sufficient rigidity to rotate the connecting ring 82 to which all the rotation shafts 81 are connected via the drive lever 84A. Furthermore, the drive lever 84A is thicker and more rigid than the other levers 84 so as to have sufficient rigidity to transmit the rotational drive force from the rotational drive shaft 81A to the connecting ring 82. . Such a rotation drive shaft 81A is connected to the variable nozzle drive device 20 (FIG. 1) disposed outside the housing 16 and is driven to rotate.

  In addition, although the inlet area variable range of the nozzle part 17 is determined by the rotation range of the variable nozzle 80, this rotation range is the supercharging capability range of the exhaust turbine supercharger 10 or the use operation range of the diesel engine 1. It is appropriately set in advance in consideration of the above. As the rotation range of the variable nozzle 80 in the present embodiment, the angle that maximizes the inlet area of the nozzle portion 17 is fully opened (100%), the operation range of the diesel engine 1 and the exhaust turbine supercharger The angle which becomes the smallest possible entrance area in the 10 supercharging capacity ranges is set to be fully closed (0%). Therefore, in this embodiment, even if the opening degree of the variable nozzle 80 is set to 0%, the substantial inlet area of the nozzle portion 17 is not zero.

  The variable nozzle drive device 20 is provided so as to drive the rotation drive shaft 81 </ b> A according to an instruction from the nozzle opening controller 50. Here, the variable nozzle driving device 20 uses hydraulic pressure in this embodiment. That is, a hydraulic circuit 21 is connected to the variable nozzle driving device 20, and hydraulic pressure is supplied by a hydraulic pump 22 in the hydraulic circuit 21. The hydraulic circuit 21 includes a pressure adjustment valve 23 composed of a proportional solenoid valve or the like. A current I based on the fuel injection amount (engine load) and the engine rotation speed is supplied to the pressure adjustment valve 23 from the nozzle opening controller 50. , The hydraulic pressure corresponding to the value of the current I is supplied to the variable nozzle driving device 20, and the rotary drive shaft 81A is rotated via the rotor rotated by the hydraulic pressure. It has come to be adjusted. However, the hydraulic pressure may be changed by using the variable hydraulic pump 22 and controlling the swash plate. Further, the variable nozzle 80 may be driven using an electric motor or a supercharging pressure regardless of the hydraulic pressure.

  As shown in FIG. 4, the lubrication circuit 30 is configured to pump up the lubricating oil in the oil pan 2A with the hydraulic pump 2B and supply it to the main gallery 31 via the oil cooler 2C and the oil filter 2D. The lubricating oil from the main gallery 31 mainly lubricates the crankshaft 2E and the camshaft 2F. Further, the lubrication circuit 30 includes an injector side circuit 32 that branches from the main gallery 31 and lubricates the cam drive unit and the like in the fuel injector 42, and a transmission mechanism side circuit that lubricates the power transmission mechanism 2G including the timing gear. 33, a rocker arm side circuit 34 that lubricates the rocker arm 2H, a supercharger side circuit 35 that lubricates a bearing portion that supports the shaft 15 of the supercharger 10, and lubricating oil from the supercharger 10 and the fuel injection device 42. A drain circuit 36 for returning to the oil pan 2A is provided.

  Among these, in the middle of the supercharger side circuit 35, a pressure sensor for detecting the pressure of the lubricating oil is located at the position of the length LS on the near side (upstream side) from the lubricating oil inlet 10A of the supercharger 10. A pressure detection means 37 constituted by a pressure switch is provided. The lubricating oil pressure P detected by the pressure detecting means 37 is output to the nozzle opening controller 50 as a pressure signal. The oil pan 2A is provided with oil temperature detecting means 38 such as an oil temperature sensor, and the oil level T of the lubricating oil detected by the oil temperature detecting means 38 is also a nozzle opening controller as an oil temperature signal. 50 is output.

  The engine controller 40 is provided to control the fuel injection amount of the engine body 2 and the like, as shown in FIG. 1, the rotational speed N obtained from the rotational speed detection sensor 41 that detects the rotational speed of the diesel engine 1, A signal such as a fuel injection amount F from a rack voltage detection sensor 43 provided in the fuel injection device 42 is received. The engine controller 40 grasps the operating state of the diesel engine 1 based on these signals, and performs control such as adjustment of the fuel injection amount according to the state. In addition, a nozzle opening controller 50 is electrically connected to the engine controller 40, and signals of the rotational speed N and the fuel injection amount F are transmitted to the nozzle opening controller 50. However, these signals may be transmitted directly from the sensors 41 and 43 to the controllers 40 and 50.

  As shown in FIG. 5, the nozzle opening controller 50 receives the signals from the engine controller 40 and the signals from the detection means 37 and 38 and outputs the current I to the pressure regulating valve 23. 51, a calculation unit 52 for calculating an appropriate value of current I based on each signal, a storage unit 53 in which various control maps and control tables are stored, and various parameters can be input by an operator. And an operation panel 54 and a timer 55 constituted by a timer or the like.

  Of these, the calculation unit 52 is configured by a computer including an MPU or the like, and can execute a nozzle opening degree determination unit 56 and a control time determination unit 57 which are computer programs (software).

  Here, the nozzle opening degree determining means 56 is the optimum opening degree of the variable nozzle 80 at each operating point in the operating range of the diesel engine 1 during normal control after the lubricant has sufficiently spread to the supercharger 10. That is, it has the function of determining the optimum nozzle opening when operating at an arbitrary fuel injection amount and engine speed. As shown in FIG. 5, the optimum nozzle opening (0 to 100%) is defined as a function of the fuel injection amount and the engine speed, and this relationship is stored in the storage unit 53 as the first map MP1. Has been. For this reason, the nozzle opening determining means 56 can determine the optimum nozzle opening from the fuel injection amount F and the rotation speed N by calling this map MP1, and can calculate the current I according to this. is there.

  On the other hand, immediately after the diesel engine 1 is started, the nozzle opening degree determining means 56 waits until the pressure P detected by the pressure detecting means 37 of the supercharger side circuit 35 becomes equal to or higher than a predetermined pressure P0 set in advance. From the time when it is determined that the pressure P0 or more is reached and until the predetermined delay time DT elapses, the current I is calculated so as to maintain the opening degree of the variable nozzle 80 at 100%, and after the delay time DT elapses. It has a function to return to normal control. Such control is performed using an engine start signal K from an engine start switch (not shown) as a trigger. As described above, in this embodiment, immediately after starting, the nozzle opening is set to 100% to increase the turbine flow rate, thereby suppressing the increase in the rotational speed of the supercharger 10 and preventing seizure. Even when the existing nozzle opening controller 50 is used, it can be handled only by changing the control program.

  The control time determination unit 57 has a function of determining the delay time DT. The delay time DT is a time until the pressure at the lubricating oil inlet 10A reaches the predetermined pressure P0 or more after the pressure at the pressure detecting means 37 reaches the predetermined pressure P0. This is the time required to reliably reach the supercharger 10. Such a delay time DT is defined by a function of the length LS in the supercharger side circuit 35 that is known for each model of the diesel engine 1 and the viscosity of the lubricating oil. This relationship is stored in the storage unit 53 as a table TBL. The viscosity of the lubricating oil is determined by the oil temperature T for each of the lubricating oil types A1, A2, and A3 used. This relationship is stored in the storage unit 53 as the second map MP2. The oil types A1, A2 and A3 of the lubricating oil in use are selectively inputted from the operation panel 54 in advance, and the oil temperature T is a value detected by the oil temperature detecting means 38. . Therefore, from these relationships, the delay time DT can be easily obtained from the oil temperature T of the lubricating oil by using the map MP2 and the table TBL. The elapsed time PT until the delay time DT is reached is measured by the timer 55.

Below, with reference to the flowchart of FIG. 6, the control for the seizing prevention of the supercharger 10 is demonstrated.
First, when the start switch is operated when the diesel engine 1 is started, the nozzle opening controller 50 is started by using the start signal K from the start switch as a trigger (S1). Next, the nozzle opening determining means 56 of the calculation unit 52 provided in the nozzle opening controller 50 increases the turbine flow rate by setting the opening of the variable nozzle 80 to 100% immediately after the engine is started, and is ejected from the variable nozzle 80. The flow rate of the exhaust gas is decreased to prevent the rotation speed of the supercharger 10 from increasing (S2). Thereafter, the nozzle opening degree determining means 56 monitors whether or not the pressure P at the pressure detecting means 37 has reached a predetermined pressure P0, and until that time, the opening degree of the variable nozzle 80 is set to 100%. Maintain (S3). Therefore, even if the engine rotational speed is increased immediately after starting, for example, by high idling, the rotational speed of the supercharger 10 does not increase, so that the supercharger 10 is not seized. Further, since it is possible to increase the engine speed without worrying about the supercharger 10 being seized, the time required for the warm-up operation can be shortened.

  When it is determined that the detected pressure P has become equal to or higher than the predetermined pressure P0, the control time determination unit 57 of the calculation unit 52 refers to the map MP2 and the table TBL based on the oil temperature T of the lubricating oil, and delay time DT. To decide. And the time measuring part 55 starts and starts time-measurement of elapsed time PT (S4). Further, the nozzle opening degree determining means 56 monitors whether or not the elapsed time PT has reached the delay time DT, and the nozzle opening degree of the variable nozzle 80 is maintained at 100% until reaching the delay time DT. Return to control. That is, the control is switched to the control using the map MP1 (S5, S6). According to this, in order to maintain the nozzle opening at 100% by adopting the delay time DT, the length LS from the pressure detecting means 37 to the lubricating oil inlet 10A of the supercharger 10 is long, or in a cold region. Even when the viscosity of the lubricating oil is high and it takes a long time for the lubricating oil to reach the lubricating oil inlet, such as during low temperature starting, the rotation of the turbocharger 10 until the lubricating oil reaches the lubricating oil inlet 10A. Can be reliably suppressed, and seizure of the supercharger 10 can be more reliably prevented. In particular, the delay time DT in the present embodiment is the oil types A1, A2, A3, the oil temperature T of the lubricating oil at that time (that is, the viscosity of the lubricating oil), and the length LS in the supercharger side circuit 35. Since it is determined based on the parameter, the reliability of the delay time DT is high.

  When the diesel engine 1 that has been sufficiently operated is temporarily stopped and restarted without much time, the lubricating oil is considered to have a relatively high oil temperature and good fluidity. Therefore, even immediately after starting, the lubricating oil reaches the lubricating oil inlet 10A in a short time, and seizure in the supercharger 10 hardly occurs. In this embodiment, when the diesel engine 1 is restarted in such a situation, the nozzle opening is once controlled to 100%, but the pressure P immediately reaches the predetermined pressure P0 due to good fluidity, and Since the delay time DT required from the high oil temperature T is very short, the time during which the nozzle opening is maintained at 100% is very short, and it is switched to normal control within a few seconds immediately after starting. Become.

[Second Embodiment]
FIG. 7 shows a table TBL stored in the storage unit 53 of the nozzle opening controller 50 according to the second embodiment of the present invention. That is, in this embodiment, the table TBL shown in FIG. 7 is used instead of the table TBL in the first embodiment shown in FIG. Further, in this embodiment, the pressure detection means 37 used in the first embodiment is not necessary. Other configurations are the same as those of the first embodiment.
In the description of the present embodiment, the same reference numerals as those in the first embodiment are used for the configurations of the respective parts not shown.

  In FIG. 7, the “length LL from the lubricating oil outlet to the inlet” used in the table TBL will be described with reference to FIG. 4. The lubricating oil inlet 2J of the hydraulic pump 2B to the lubricating oil inlet of the supercharger 10 The length is up to 10A. The “arrival time AT” is a time determined by the viscosity of the lubricating oil, and is a time until the lubricating oil reaches the lubricating oil inlet 10A from the lubricating oil outlet 2J. The arrival time AT is determined based on parameters such as the oil temperature T of the lubricating oil at that time (that is, the viscosity of the lubricating oil) in addition to the length LL, as in the first embodiment. According to this embodiment, the elapsed time PT from immediately after the engine is started (that is, immediately after the hydraulic pump is started) is measured, and the nozzle opening is maintained at 100% until the elapsed time PT reaches the arrival time AT. Is done.

Hereinafter, the present embodiment will be described more specifically with reference to the flowchart of FIG.
First, when the start switch is operated when the engine is started, the nozzle opening controller 50 is activated by the start signal K (S1). Next, the nozzle opening degree determination means 56 of the calculation unit 52 sets the opening degree of the variable nozzle 80 to 100% immediately after the engine is started, and reduces the flow rate of the exhaust gas ejected from the variable nozzle 80 to rotate the rotational speed of the supercharger 10. Is suppressed from rising (S2). Thereafter, the control time determination means 57 of the calculation unit 52 determines the arrival time AT based on the oil temperature T of the lubricating oil with reference to the map MP2 and the table TBL. Then, the timer unit 55 is activated and starts counting the elapsed time PT (S3). Further, the nozzle opening degree determining means 56 monitors whether or not the elapsed time PT has reached the arrival time AT, and the nozzle opening degree of the variable nozzle 80 is maintained at 100% until reaching the arrival time AT. Return to control (S5).

According to the present embodiment, since the arrival time AT is adopted and the nozzle opening degree is maintained at 100%, after the engine is started, the lubricating oil does not reach the lubricating oil inlet 10A from the lubricating oil outlet 2J, and the supercharger 10 In a state where the oil is not lubricated, the rotational speed of the supercharger 10 can be suppressed, and seizure of the supercharger 10 can also be prevented.
Further, in the present embodiment, since the pressure detecting means 37 as in the first embodiment is unnecessary, there is nothing to add other than the configuration used in the conventional variable turbo, and the configuration can be further simplified. Economical.
In addition, since the control using the pressure P from the pressure detection means 37 is not necessary, the control step can be simplified.

In addition, this invention is not limited to the said embodiment, Including other structures etc. which can achieve the objective of this invention, the deformation | transformation etc. which are shown below are also contained in this invention.
For example, in each of the above embodiments, the oil types A1, A2, A3, the lengths LS, LL in the lubricating circuit 30 and the oil temperature T of the lubricating oil are used to determine the delay time DT and the arrival time AT. However, the present invention is not limited to this, and at least of oil types A1, A2, A3, lengths LS, LL, oil temperature T, water temperature of the cooling water of diesel engine 1, and atmospheric temperature. It is sufficient if one parameter is used. Moreover, you may use combining these parameters arbitrarily.

  In the first embodiment, the nozzle opening degree is set to 100% until the predetermined delay time DT elapses after the pressure P of the pressure detection means 37 is detected. For example, the pressure detection means 37 is lubricated. When it is provided at a position very close to the oil inlet 10A and it is considered that the time until the lubricating oil reaches the lubricating oil inlet 10A from this position is almost negligible, the step using the delay time DT may be omitted. . That is, it is sufficient to make the nozzle opening 100% until the pressure P reaches the predetermined pressure P0.

  In each of the above embodiments, the nozzle opening degree is controlled to 100% in order to prevent seizing of the supercharger 10, but it is sufficient that the nozzle opening degree is increased to a rotational speed at which seizure does not substantially occur. May be less than 100%.

  The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of quantity, method, and other detailed configurations.

  The present invention is used for preventing seizure of a supercharger provided in a diesel engine or a gasoline engine, and is particularly suitable for a supercharger of an engine operated in a cold region. In addition to a construction machine, an automobile, a truck for transportation, or the like may be installed as such an engine.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the whole engine by which the supercharger seizing prevention apparatus which concerns on 1st Embodiment of this invention is mounted. Sectional drawing which shows a supercharger. The front view which shows the component of a supercharger. The schematic diagram which shows the lubrication circuit of an engine. The block diagram which shows a control means. The flowchart for demonstrating the control method in 1st Embodiment. The figure which shows the control table used in 2nd Embodiment of this invention. The flowchart for demonstrating the control method in 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2B ... Hydraulic pump, 2J ... Lubricating oil outlet, 10 ... Supercharger, 10A ... Lubricating oil inlet, 30 ... Lubrication circuit, 37 ... Pressure detection means, 50 ... Nozzle opening controller (control means), 55 ... Time measuring part, 57 ... Control time determining means, 60 ... Turbine flow rate variable mechanism, 70 ... Supercharger seizure prevention device, 80 ... Variable nozzle (variable geometallic turbine nozzle), A1, A2, A3 ... Oil type, AT ... arrival time, DT ... delay time, PT ... elapsed time, LL, LS ... length, P ... pressure, T ... oil temperature.

Claims (5)

A supercharger seizure prevention device (70) for preventing seizure of a supercharger (10) having a turbine flow rate variable mechanism (60),
The turbine flow rate variable mechanism (60) makes the turbine flow rate variable by adjusting an inlet area of a nozzle portion provided in the supercharger (10),
Pressure provided between the lubricating oil outlet (2J) of the hydraulic pump (2B) incorporated in the lubricating circuit (30) of the engine (1) and the lubricating oil inlet (10A) of the supercharger (10). Detection means (37);
In response to the signal from the pressure detection means (37), until it is determined that the oil pressure (P) of the lubricating oil inlet (10A) has reached a predetermined pressure (P0) or more, the supercharger ( And 10) control means (50) for controlling the turbine flow rate characteristic variable mechanism (60) in a direction in which rotation is suppressed.
The viscosity of the lubricating oil is determined by at least one of the lubricating oil temperature (T), the engine cooling water temperature and the atmospheric temperature, and the lubricating oil type (A1, A2, A3),
The control means (50) includes the length (LS) from the position where the pressure detection means (37) detects the pressure (P) to the lubricating oil inlet (10A) of the supercharger (10) and the lubricating oil. Delay time (DT) from when the pressure detecting means (37) reaches the predetermined pressure (P0) until the pressure at the lubricating oil inlet (10A) becomes equal to or higher than the predetermined pressure (P0). It is determined and until this delay time (DT) has elapsed, the inlet area of the nozzle portion by a larger, supercharger and maintains control of the system you increase the turbine flow Anti-seizure device (70). A supercharger seizure prevention device (70) for preventing seizure of a supercharger (10) having a turbine flow rate variable mechanism (60),
The turbine flow rate characteristic variable mechanism (60);
A timer (55) for measuring the elapsed time (PT) from the start of the engine (1);
Control for controlling the turbine flow rate characteristic variable mechanism (60) in a direction in which the rotation of the supercharger (10) is suppressed until the elapsed time (PT) reaches a predetermined arrival time (AT) or more. Means (50) ,
The viscosity of the lubricating oil is determined by at least one of the lubricating oil temperature (T), the engine cooling water temperature and the atmospheric temperature, and the lubricating oil type (A1, A2, A3),
The control means (50) depends on the length (LL) from the lubricating oil outlet (2J) of the hydraulic pump (2B) to the lubricating oil inlet (10A) of the supercharger (10) and the viscosity of the lubricating oil. A supercharger seizure prevention device (70), characterized in that said arrival time (AT) is determined . In the supercharger seizure prevention device (70) according to claim 1 or 2 ,
The turbine flow rate variable mechanism (60) includes a variable geometallic turbine nozzle (80) whose nozzle opening is adjustable,
The said control means (50) is comprised so that rotation of the said supercharger (10) may be suppressed by controlling to the direction which enlarges a nozzle opening degree. 70). A control method for a supercharger seizure prevention device (70) for preventing seizure of a supercharger (10) having a turbine flow rate variable mechanism (60),
The detected pressure of the pressure detecting means (37) provided between the lubricating oil outlet (2J) of the hydraulic pump (2B) and the lubricating oil inlet (10A) of the supercharger (10) is equal to or higher than a predetermined pressure (P0). Then, the control means (50) for controlling the turbine flow rate variable mechanism (60) determines the viscosity of the lubricating oil based on the oil temperature (T) of the lubricating oil,
The pressure of the lubricating oil and the length (LS) from the position where the pressure detecting means (37) detects the pressure (P) to the lubricating oil inlet (10A) of the supercharger (10) A delay time (DT) from when the predetermined pressure (P0) is reached by the detection means (37) until the pressure at the lubricating oil inlet (10A) becomes equal to or higher than the predetermined pressure (P0) is determined,
The timer (55) measures the elapsed time (PT) after the detected pressure of the pressure detecting means (37) becomes equal to or higher than a predetermined pressure (P0) until the delay time (DT) is reached.
The supercharger seizure prevention device (70) control method characterized by the above-mentioned. A control method for a supercharger seizure prevention device (70) for preventing seizure of a supercharger (10) having a turbine flow rate variable mechanism (60),
The control means (50) for controlling the turbine flow rate variable mechanism (60) determines the viscosity of the lubricating oil based on the oil temperature (T) of the lubricating oil,
The arrival time (AT) is determined by the viscosity of the lubricating oil and the length (LL) from the lubricating oil outlet (2J) of the hydraulic pump (2B) to the lubricating oil inlet (10A) of the supercharger (10). do it,
A turbocharger that measures the elapsed time (PT) until the arrival time (AT) is reached by a timekeeping section (55) that measures the elapsed time (PT) from the start of the engine (1). Control method of seizure prevention device (70).

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