JP2021055607A - Engine system and engine system control device - Google Patents

Abstract

To provide an engine system and engine system control device capable of improving a turbo lag.SOLUTION: An engine system 1 comprises: an engine 10 mounted on a vehicle; and a turbocharger 40 which is driven with energy of exhaust discharged from the engine so as to supercharge intake air sucked into the engine. The engine system also has: an oil jet 74 which injects oil toward a piston 12 arranged inside a cylinder 11 of the engine; and a control device 60 which performs control to execute oil injection through the oil jet when an increase rate of an acceleration opening of a vehicle is lower than a preset reference value (S20) and stop the oil injection through the oil jet when the increase rate of the acceleration opening is equal to or larger than the reference value (S30).SELECTED DRAWING: Figure 3

Description

The present disclosure relates to an engine system and an engine system control device.

Conventionally, an engine system including an engine and a turbocharger that receives the energy of the exhaust discharged from the engine and drives the turbocharger to supercharge the intake air sucked into the engine is known (see, for example, Patent Document 1). .. Further, conventionally, as a mechanism for cooling the piston of an engine, an oil jet that injects oil toward the piston is known (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2012-7541 Japanese Unexamined Patent Publication No. 2015-71999

By applying an oil jet to a conventional engine system including an engine and a turbocharger as described above, the piston can be cooled. However, when the rate of increase in the accelerator opening of the vehicle exceeds the reference value (for example, when the accelerator pedal is suddenly depressed), when the oil is injected from the oil jet, it is injected from the oil jet. Cooling the piston with oil makes it easier for heat in the cylinder to escape to the piston, which makes it difficult for heat in the cylinder to escape to the exhaust, lowering the exhaust temperature and increasing the turbo lag of the turbocharger.

The present disclosure has been made in view of the above, and an object of the present disclosure is to provide an engine system capable of improving turbo lag and a control device for the engine system.

In order to achieve the above object, the engine system according to the present disclosure includes an engine mounted on a vehicle and a turbocharger that receives and drives the energy of the exhaust discharged from the engine to supercharge the intake air sucked into the engine. In an engine system including a charger, when the oil jet that injects oil toward a piston arranged in the cylinder of the engine and the rate of increase in the accelerator opening of the vehicle are lower than a preset reference value. Is a control device that executes the injection of oil from the oil jet and stops the injection of oil from the oil jet when the rate of increase in the accelerator opening is equal to or greater than the reference value. It is characterized by being prepared.

Further, in order to achieve the above object, the control device of the engine system according to the present disclosure is driven by receiving the energy of the engine mounted on the vehicle and the exhaust discharged from the engine, and is sucked into the engine. A control device for an engine system including a turbocharger for supercharging an engine and an oil jet for injecting oil toward a piston arranged in a cylinder of the engine. The control device is an accelerator for the vehicle. When the increase rate of the opening degree is lower than the preset reference value, the injection of oil from the oil jet is executed, and when the increase rate of the accelerator opening degree is equal to or more than the reference value, the oil jet is used. It is characterized by executing control to stop the injection of oil.

According to the present disclosure, turbo lag can be improved.

It is a block diagram which shows typically the whole structure of the engine system which concerns on embodiment. It is a block diagram for demonstrating the structure of the oil supply device which concerns on embodiment. This is an example of a flowchart for explaining the control of the oil jet according to the embodiment.

Hereinafter, the engine system 1 and the control device 60 of the engine system 1 according to the embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a configuration diagram schematically showing the overall configuration of the engine system 1 according to the present embodiment. The engine system 1 is mounted on the vehicle. The specific type of this vehicle is not particularly limited, and various vehicles such as passenger cars, trucks, and buses can be used. The engine system 1 illustrated in FIG. 1 includes an engine 10, an intake passage 20, an exhaust passage 30, a turbocharger 40, an accelerator pedal 50, an accelerator opening sensor 55, a control device 60, and an oil supply. It includes a device 70.

The type of the engine 10 is not particularly limited, but in the present embodiment, a diesel engine using light oil as a fuel is used as an example. As the engine 10, a gasoline engine using gasoline as fuel can also be used. The engine 10 includes a cylinder block having a cylinder 11, a cylinder head arranged on the upper part of the cylinder block, and a piston 12 arranged inside the cylinder 11 (hereinafter, referred to as “inside the cylinder”) (shown in FIG. 2 to be described later). ), A crankshaft connected to the piston 12 via a conrod, a fuel injection valve that injects fuel into each cylinder, an intake valve that opens and closes the intake port of the engine 10, and an exhaust that opens and closes the exhaust port of the engine 10. It is equipped with a valve drive mechanism (cam, camshaft, etc.) that drives valves, intake valves, and exhaust valves. The engine 10 according to the present embodiment has four cylinders 11 as an example, but the number of cylinders 11 is not limited to four, and may be one or more.

The intake passage 20 is a passage through which the intake air sucked into the engine 10 passes, and its downstream end is connected to the intake port of the engine 10. The exhaust passage 30 is a passage through which the exhaust gas discharged from the engine 10 passes, and its upstream end is connected to the exhaust port of the engine 10.

The turbocharger 40 is a device that receives and drives the energy of the exhaust gas discharged from the engine 10 to supercharge the intake air sucked into the engine 10. The turbocharger 40 includes a turbine 41 arranged in the exhaust passage 30, a compressor 42 arranged in the intake passage 20, and a connecting shaft 43 connecting the turbine 41 and the compressor 42. When the turbine 41 rotates by receiving the energy of the exhaust gas, the compressor 42 connected to the turbine 41 via the connecting shaft 43 rotates. The rotation of the compressor 42 supercharges the intake air taken into the engine 10.

The accelerator pedal 50 is arranged in the driver's seat of the vehicle. The driver of the vehicle can adjust the speed of the vehicle by adjusting the amount of depression of the accelerator pedal 50. The accelerator opening sensor 55 detects the opening degree of the accelerator pedal 50 and transmits this detected value to the control device 60. The greater the amount of depression of the accelerator pedal 50, the larger the accelerator opening. A brake pedal is also arranged in the driver's seat, but this illustration is omitted. In addition to the accelerator opening sensor 55, the engine system 1 is provided with various sensors such as a brake opening sensor for detecting the brake opening and a crank angle sensor for detecting the crank angle of the engine 10. Illustration of these sensors is omitted.

The control device 60 controls the operation of the engine 10 by controlling the fuel injection valve of the engine 10. The control device 60 also controls the operation of the oil jet 74 of the oil supply device 70, which will be described later. Such a control device 60 includes a microcomputer having a CPU (Central Processing Unit) 61 as a processor and a storage device 62 for storing various information and programs used for the operation of the CPU 61. The storage device 62 is composed of a storage medium such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

FIG. 2 is a configuration diagram for explaining the configuration of the oil supply device 70. The oil supply device 70 includes an oil pump 71, a first oil flow path 72, a second oil flow path 73, an oil jet 74, and an on-off valve 75.

The oil pump 71 is a device for pumping oil. The oil pump 71 according to the present embodiment is driven by the power of the engine 10 (specifically, the power of the crankshaft) to pump oil. The first oil flow path 72 is an oil flow path that communicates the oil pump 71 and the oil jet 74. Specifically, the first oil flow path 72 according to the present embodiment starts from the oil pump 71, then branches into a plurality of oil flow paths 72 in the middle, and communicates with each oil jet 74. The second oil flow path 73 is an oil flow path that connects the oil pump 71 and the lubricated portion 80 of the engine 10. Examples of the lubricated portion 80 include a crankshaft of the engine 10, a camshaft of the engine 10, and the like.

The oil jet 74 is a device that injects oil toward a piston 12 arranged in the cylinder of the engine 10. Specifically, the oil jets 74 according to the present embodiment are provided so as to correspond to the respective pistons 12, and a total of four oil jets 74 are provided. Further, the oil jet 74 is arranged at a position below the piston 12 in the cylinder block portion of the engine 10. The oil pumped from the oil pump 71 is supplied to the oil jet 74 via the first oil flow path 72. The oil jet 74 injects oil from the lower side toward the back surface of the piston 12 (the surface facing the crankshaft side). The oil injected from the oil jet 74 can effectively cool the piston 12.

The on-off valve 75 is arranged in the first oil flow path 72. Specifically, the on-off valve 75 according to the present embodiment is arranged at the "point where one joins" in the first oil flow path 72. However, the location of the on-off valve 75 is not limited to this. For example, the oil supply device 70 may be provided with an on-off valve 75 at each of the “plurality of branches” in the first oil flow path 72.

The on-off valve 75 is controlled by the control device 60 to switch between a valve open state and a valve closed state. When the control device 60 controls the on-off valve 75 to the valve open state, a part of the oil pumped from the oil pump 71 passes through the first oil flow path 72 and is supplied to each oil jet 74, respectively. Is injected from the oil jet 74 of the above toward each piston 12. On the other hand, when the control device 60 controls the on-off valve 75 to the closed state, the oil supply from the oil pump 71 to the oil jet 74 is stopped. As a result, the injection of oil from the oil jet 74 to the piston 12 is also stopped. That is, the control device 60 according to the present embodiment switches between executing the oil injection from the oil jet 74 and stopping the oil injection by controlling the on-off valve 75.

Subsequently, the details of the control of the oil jet 74 by the control device 60 will be described. FIG. 3 is an example of a flowchart for explaining the control of the oil jet 74 by the control device 60. Each step of FIG. 3 is executed by the CPU 61 of the control device 60 based on the program of the storage device 62. Further, the control device 60 starts the flowchart of FIG. 3 at the same time as the start of the engine 10. That is, the flowchart of FIG. 3 is executed during the operation of the engine 10.

In step S10, the control device 60 determines whether or not the increase rate of the accelerator opening degree of the vehicle (hereinafter, referred to as "accelerator opening degree increase rate") is lower than the preset reference value. The specific numerical value of the reference value according to step S10 is not particularly limited, but in the present embodiment, as the reference value related to this step S10, when the accelerator opening opening increase rate becomes equal to or higher than this reference value. A value that can be determined that the accelerator pedal 50 is suddenly depressed is used. That is, in the present embodiment, when NO is determined in step S10 (when the accelerator opening degree increase rate is equal to or higher than the reference value), it corresponds to the case where the accelerator pedal 50 is suddenly depressed. An appropriate value of this reference value is obtained by conducting an experiment, a simulation, or the like in advance, and is stored in a storage device 62 (for example, ROM).

The control device 60 according to the present embodiment acquires the accelerator opening degree based on the detected value of the accelerator opening degree sensor 55, and calculates the amount of increase in the acquired accelerator opening degree per unit time to open the accelerator. Get the rate of increase. Then, the control device 60 determines whether or not the accelerator opening degree increase rate is lower than the reference value by comparing the acquired accelerator opening degree increase rate with the reference value of the storage device 62.

If YES is determined in step S10 (when the accelerator opening opening rate increase rate is lower than the reference value, that is, when the accelerator pedal 50 is not suddenly depressed), the control device 60 injects oil from the oil jet 74. It is executed (step S20).

Specifically, the control device 60 according to the present embodiment controls the on-off valve 75 to the valve open state to execute oil injection from each oil jet 74. If the oil injection from the oil jet 74 has already been executed before the execution of step S20, the control device 60 continues the execution of the oil injection from the oil jet 74 in step S20. After step S20, the control device 60 re-executes the flowchart from the start (return). By executing the oil injection according to step S20, the piston 12 can be effectively cooled.

On the other hand, when NO is determined in step S10 (when the accelerator opening opening increase rate is equal to or higher than the reference value, that is, when the accelerator pedal 50 is suddenly depressed), the control device 60 determines that the oil from the oil jet 74 is used. The injection is stopped (step S30). Specifically, the control device 60 according to the present embodiment stops the oil injection from each oil jet 74 by controlling the on-off valve 75 in the closed state. After step S30, the control device 60 re-executes the flowchart from the start (return).

According to the present embodiment as described above, when the accelerator opening opening increase rate is equal to or higher than the reference value (NO in step S10), the oil injection from the oil jet 74 is stopped in step S30. As a result, cooling of the piston 12 by oil can be suppressed, and the amount of heat escaping from the cylinder of the engine 10 to the piston 12 can be reduced. Then, as the amount of heat escaping from the cylinder to the piston 12 is reduced, the amount of heat escaping from the cylinder to the exhaust is increased, so that the exhaust temperature can be raised. By raising the exhaust temperature in this way, the exhaust energy can be raised, so that the rotation speed of the turbocharger 40 (the rotation speed of the turbine 41 and the compressor 42) can be raised at an early stage. Thereby, the turbo lag can be improved (that is, the turbo lag can be reduced).

Further, according to the present embodiment, the acceleration performance of the engine 10 can be improved by improving the turbo lag as described above. Further, by improving the turbo lag, it is possible to reduce the amount of soot discharged from the engine 10, and it is also possible to suppress the deterioration of fuel efficiency.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the claims.

1 Engine system 10 Engine 11 Cylinder 12 Piston 40 Turbocharger 50 Accelerator pedal 60 Control device 70 Oil supply device 74 Oil jet

Claims (2)

In an engine system including an engine mounted on a vehicle and a turbocharger that receives and drives the energy of exhaust gas discharged from the engine to supercharge the intake air sucked into the engine.
An oil jet that injects oil toward a piston arranged in the cylinder of the engine, and
When the rate of increase in the accelerator opening of the vehicle is lower than the preset reference value, oil is injected from the oil jet, and when the rate of increase in the accelerator opening is equal to or greater than the reference value, the said An engine system characterized by comprising a control device that executes control for stopping oil injection from an oil jet. Toward the engine mounted on the vehicle, the turbocharger that receives the energy of the exhaust gas discharged from the engine and supercharges the intake air sucked into the engine, and the piston arranged in the cylinder of the engine. It is a control device of an engine system equipped with an oil jet that injects oil.
When the rate of increase in the accelerator opening of the vehicle is lower than a preset reference value, the control device executes oil injection from the oil jet, and the rate of increase in the accelerator opening is equal to or greater than the reference value. In the case of, the control device of the engine system, characterized in that the control for stopping the injection of oil from the oil jet is executed.

Images