KR20080055361A - Piston cooling jet system for automobile and method for controlling the same - Google Patents

Abstract

A variable type piston cooling jet apparatus for a vehicle is provided to prevent total oil pressure reduction and oil consumption increase while excluding unnecessary oil injection by using an electronic type control vale which is open/closed according to ECU control signals. A variable type piston cooling jet apparatus for a vehicle comprises an oil jet installed on each cylinder to inject engine oil supplied through an electronic control valve(20) and a cooling jet line into a piston, an ECU outputting control signal, an electronic control valve to selectively open an internal passage connected with the cooling jet line. The electronic control valve includes a housing(21) having an inlet connected to the oil supply line and a plurality of outlet connected to the cooling jet line, a supply control plate(22) formed with a penetration holes to open the outlet, and a step motor(23) to rotate the supply control plate.

Description

Piston cooling jet system for automobile and method for controlling the same

1 is a schematic view showing a piston cooling jet apparatus according to the prior art,

2 is a view for explaining the operating conditions of the piston cooling jet apparatus,

3 is a view showing the effect of the piston cooling jet device,

4 is a block diagram of a variable piston cooling jet apparatus according to the present invention,

Figure 5 is a cross-sectional view showing a state in which the oil injection by the oil jet in the variable piston cooling jet apparatus according to the present invention,

6 is a cross-sectional view showing an embodiment of an electronic control valve used in the present invention,

Figure 7 is an exploded perspective view of the electronic control valve shown in Figure 6,

8 is a state diagram showing an open state of the outlet part according to the rotational position of the supply control panel in the electronic control valve shown in FIG.

9 is a state diagram showing the oil supply state according to the rotational position of the supply control panel in the electronic control valve shown in FIG.

10 is an operating state according to the operating mode of the variable piston cooling jet apparatus according to the present invention,

11 is a view showing an example of mode conversion for variable control of a variable piston cooling jet according to the present invention;

12 is a flowchart illustrating a mode conversion process according to a reference speed and a reference temperature of a variable piston cooling jet according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: ECU 20: electronic control valve

21 housing 22 supply control panel

23: step motor 30: oil jet

The present invention relates to a variable piston cooling jet device for an automobile, and more particularly, by using an electronic control valve opened and closed by a control signal of an ECU instead of a conventional mechanical check valve opened and closed by an oil pressure of a main oil gallery. In addition, the present invention relates to a variable piston cooling jet device for an automobile, in which oil injection is possible in an optimal operating mode set according to an engine condition, and thus unnecessary oil injection can be prevented therefrom.

As the performance of automobile engines is improved, the thermal load received by the piston increases, and one of the methods for reducing the thermal load of the piston is a piston cooling jet device that supplies and cools the engine oil to the piston.

1 is a schematic view showing the configuration of a piston cooling jet device according to the prior art, Figure 2 is a view for explaining the operating conditions of the piston cooling jet device, Figure 3 is a view showing the effect of the piston cooling jet device to be.

The piston cooling jet device includes an oil jet (7) which is an oil injection part fastened to the cylinder block of the engine, and a mechanical check valve (6) is provided between the main oil gallery (4) and the oil jet (7). When the oil pressure is equal to or higher than a predetermined pressure (check valve opening pressure), the check valve 6 is opened and oil is injected through the oil jet 7.

As described above, in the conventional piston cooling jet apparatus, the opening and closing of the check valve 6 is determined by the oil pressure of the main oil gallery 4, but the engine oil temperature increases significantly in the engine high rotation / high load state requiring oil injection. Accordingly, the viscosity of the engine oil is lowered, resulting in an oil pressure drop.

Therefore, the check valve opening pressure, which is determined in consideration of the oil pressure drop described above, is usually set between 1.5 and 2 bar, and most operation except the hot idle state where the actual oil temperature is high by setting the opening pressure of the check valve. In this condition, the check valve 6 is opened so that oil is injected through the oil jet 7.

Accordingly, the conventional piston cooling jet apparatus has a disadvantage in that oil is injected while the check valve 6 is opened even in unnecessary conditions in addition to high rotation / high load conditions in which the actual piston 1 needs to be cooled.

In other words, in the conventional piston cooling jet apparatus, the mechanical check valve is operated at a predetermined oil pressure or higher, and in particular, the oil is sprayed only in dependence on the oil pressure regardless of the operating conditions of the engine. As can be said, this excess oil supply causes a reduction in the overall oil pressure and leads to increased fuel consumption and exhaust gas degradation due to increased oil consumption and cold piston overcooling.

Therefore, the present invention has been invented to solve the above problems, by using an electronic control valve that is opened and closed by the control signal of the ECU instead of the conventional mechanical check valve that is opened and closed by the oil pressure of the main oil gallery, It is possible to inject oil in the optimum operating mode set according to the condition, and to prevent unnecessary oil injection therefrom, to prevent the reduction of total oil pressure and increase of oil consumption, and to prevent piston supercooling due to unnecessary oil injection during cold operation. It is an object of the present invention to provide a variable piston cooling jet device for automobiles that can prevent fuel consumption and exhaust gas deterioration.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention is installed in each cylinder of the engine, each of which is connected to the following electronic control valve via a cooling jet line, the oil for injecting the engine oil supplied through the following electronic control valve and the cooling jet line for piston cooling for cooling With a jet; An ECU which receives a signal of a sensing element in which a vehicle is installed and outputs a control signal for each operation mode set according to an engine state; The engine oil is supplied through the oil supply line connected from the main oil gallery, and driven and controlled by a control signal for each operation mode according to the engine state output from the ECU, so that the supplied engine oil is selected cooling jet line and the final oil connected thereto. In order to be supplied to the jet, it provides a variable piston cooling jet device for an automobile comprising an; an electronic control valve that is open selectively the internal flow path connected to each cooling jet line.

Preferably, the electronic control valve, the housing having an inlet portion to which the oil supply line is connected, and a plurality of outlet portions to which the cooling jet line is connected; A supply control panel having a plurality of flow path holes for opening the outlet part and being rotatably embedded in the housing to close or open all the outlet parts or open only a selected part according to a rotation position; And a step motor for rotating the supply control panel while being driven and controlled by the control signal output from the ECU.

In addition, the cooling jet line is connected to a plurality of oil jets through branch lines, so that the electronic control valve is driven and controlled by the control signal output from the ECU so that engine oil can be simultaneously injected in the plurality of engine cylinders. It is characterized by.

In addition, the ECU controls the electronic control valve so that oil is supplied to the oil jet of the cylinder when the piston of each engine cylinder is in the top dead center position when it is determined that the initial start of the engine and the engine cold start time are based on the signal input from the sensing element. It characterized in that for outputting a control signal for controlling.

In addition, the ECU outputs a control signal for controlling the electronic control valve to block all internal flow paths connected to the cooling jet line to block engine electric oil injection when the engine warm load is determined based on a signal input from a sensing element. It is characterized by.

In addition, the ECU controls the electronic control valve to open all internal flow paths connected to the cooling jet line for the engine electric oil injection when determining the engine high rotation / high load based on a signal input from the sensing element.

In addition, the oil jet is characterized in that the nozzle direction is set to inject the engine oil between the piston and the bore in the cylinder.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

The present invention relates to a variable piston cooling jet apparatus using an electronic control valve that variably controls oil supply under the control of an ECU, excluding the use of a mechanical check valve that is always modified above a certain oil pressure (opening pressure of a set check valve). It is about.

4 is a block diagram of a variable piston cooling jet apparatus according to the present invention.

As shown in the drawing, in the variable piston cooling jet apparatus according to the present invention, instead of the conventional mechanical check valve which is opened and closed by the oil pressure of the main oil gallery 4, the oil supply passage is controlled by the control signal of the ECU 10. An electronic control valve 20 that can be opened and closed is employed.

Referring to FIG. 4, the variable piston cooling jet apparatus of the present invention receives engine oil supplied through the main oil gallery 4 as in the related art, and the main oil gallery 4 is provided by an oil pump 3. Engine oil will be supplied.

As described above, the engine oil supplied from the main oil gallery 4 is injected into the piston 1 of the engine cylinder through a flow path selected (opened) by the electronic control valve 20.

In a preferred embodiment according to the invention, two oil supply lines (hereinafter referred to as cooling jet lines) 24a and 25a are connected from the electronic control valve 20, and each cooling jet line 24a and 25a is connected to each other. Branched into two branching lines 24b and 25b, the ends of each branching line 24b and 25b are connected to an oil jet 30 installed in each cylinder.

Accordingly, the engine oil is simultaneously supplied to two engine cylinders through each cooling jet line 24a and 25a. When the engine oil is supplied through one or two cooling jet lines 24a and 25a, each cooling is performed. Engine oil is injected into two engine cylinders through two oil jets 30 finally connected to each of the jetlines 24a and 25a.

That is, when engine oil is supplied to one cooling jet line 24a and 25a, the engine oil is simultaneously injected into two cylinders through two oil jets 30, and the engine is applied to both cooling jet lines 24a and 25a. When oil is supplied, engine oil is simultaneously injected into four cylinders through four oil jets 30.

Here, the branch lines branched from the same cooling jet line are connected to the cylinders in the same phase, for example, the engine cylinders 1 and 4 and the engine cylinders 2 and 3, and each branch line 24b and 25b. At the end of the oil jet 30 for injecting oil to the piston (1) in the cylinder is installed.

The oil jet 30 sprays the supplied engine oil to the piston 1 when the engine oil is supplied through the cooling jet lines 24a and 25a and the branch lines 24b and 25b by the opening of the electronic control valve 20. It is a simple nozzle mechanism.

As a result, the engine oil supplied through the main oil gallery 4 is sequentially supplied to each of the cooling jet lines 24a and 25a, the branch lines 24b and 25b, and the oil jet 30 through the electronic control valve 20. It is finally injected to the piston 1 in each cylinder, the engine oil so injected to cool the piston (1).

In the present invention, each oil jet 30 is fixed to the cylinder block as in the prior art, but as shown in the accompanying Figure 5, the nozzle so as to spray the engine oil between the piston (1) and the bore (2) in the cylinder The direction is set.

Meanwhile, the ECU 10 controls the electronic control valve 20 to inject the engine oil in the injection mode set according to the state of the engine. For example, the ECU 10 includes the engine speed, the intake air amount, and the main oil gallery. The oil pressure and oil temperature supplied to the piston, the piston position is input to control the electronic control valve 20 so that the engine oil can be injected in the injection mode set based on this.

Hereinafter, the electronic control valve used in the present invention will be described in detail.

6 is a cross-sectional view showing an embodiment of the electronic control valve used in the present invention, Figure 7 is an exploded perspective view of the electronic control valve shown in FIG.

In addition, FIG. 8 is a state diagram illustrating an outlet part according to a rotational position of the supply control panel 22 in the electronic control valve 20 shown in FIG. 6, and FIG. 9 is an oil supply according to the rotational position of the supply control panel. It is a state diagram which shows the state.

As shown, the electronic control valve 20 is largely composed of a housing 21, a supply control plate 22, a step motor 23, the inlet portion 21a formed in the front side in the housing 21 An oil supply line 5 is connected to the engine oil supply from the main oil gallery 4, and the two outlet portions 21b and 21c formed at the rear side supply the engine oil to the oil jet 30 of the engine cylinder. Cooling jet lines 24a and 25a are connected to each other.

The housing 21 is rotatably provided with a supply control panel 22 that selectively connects the inlet portion 21a and the outlet portions 21b and 21c according to the rotational position. A plurality of flow path holes 22a through which the two outlet portions 21b and 21c can be selectively opened are formed through the rotation position.

In the illustrated embodiment, a total of three flow path holes 22a are formed in the supply control panel 22 so as to simultaneously open two outlets 21b and 21c or selectively open one of them.

In addition, a step motor 23 is installed outside the housing 21 as an actuator for rotating the supply control panel 22, and the rotation shaft 23a of the step motor 23 is integral to the rotation center of the supply control panel 22. Is fixed.

The step motor 23 is provided such that forward and reverse rotation is controlled by a control signal output from the ECU 10, and driven and controlled by the control signal output by the ECU 10, while the supply control panel 22 inside the housing 21 is controlled. Rotated).

 As a result, while the step motor 23 is driven forward and backward under the control of the ECU 10, the rotational position of the supply control panel 22 is controlled, and the outlet of the electronic control valve 20 is controlled in accordance with the rotational position of the controlled supply control panel 22. Either one of the two outlets 21b and 21c, which are flow paths, may be selectively opened or two outlets 21b and 21c may be simultaneously opened.

Of course, the supply control panel 22 is rotated to a position in which both the outlet portions 21b and 21c are closed by the step motor 23 driven under the control of the ECU 10 in an engine state where oil injection is unnecessary.

On the other hand, in the variable piston cooling jet apparatus of the present invention configured as described above, when the ECU 10 receives a signal from each sensing element pre-mounted in the vehicle, the ECU 10 is applied to each engine state based on the input signal. The control signal is outputted accordingly, and the control signal is operated in the preset operation mode.

Here, in order to operate the piston cooling jet device in each operation mode by the ECU 10, the ECU 10 outputs a control signal according to the operation mode to control the step motor 23, which is a step motor 23 Each operation mode is implemented while the operating state and the open path state of the electronic control valve 20 are controlled by the drive control.

As described above, the ECU 10 includes the engine speed detected by the engine speed sensor, the intake air amount detected by the air flow meter, the oil temperature and oil pressure detected by the temperature sensor and the pressure sensor, the crank position sensor and the cam. The electronic control valve 20 allows the piston cooling jet device to operate in a preset operation mode according to the engine condition according to the position of the piston 1 detected by the position sensor and the coolant temperature (engine temperature) detected by the water temperature sensor. To control the operation of the step motor 23 more clearly.

Table 1 shows the operating state of the piston cooling jet device according to the engine condition, the piston cooling jet device is operated in three operating modes, each operation mode by the ECU 10 controls the electronic control valve 20 It works as

As the operation mode, a first operation mode in which the engine oil is injected only at the top dead center position of the piston (1) of each cylinder when the engine is cold including the initial start, and a second that blocks the engine oil injection during the engine warm low load operation. In the operation mode, the engine is operated in a third operation mode in which the engine oil is simultaneously sprayed to the engine cylinder at high rotation / high load.

10 is an operation state diagram according to each operation mode. As shown in (a) and (b) of FIG. 10, the number 1 and the number 1 present in the same phase during engine cold injection of the engine oil only at the piston top dead center position. When the piston 1 of the 4th cylinder is in the top dead center position (Fig. 10 (a) position) and when the piston 1 of the 2nd and 3rd cylinders is in the top dead center position (Fig. 10 ( b) position, respectively, to inject the engine oil through the oil jet 30 of the corresponding cylinder (first operation mode).

At this time, the first cooling jet line 24a connected through the branch lines 24b and 25b to the oil jet 30 installed in the first and fourth cylinders so that the engine oil is injected into the first and fourth cylinders. (A) of FIG. 9, the supply control panel 22 of the electronic control valve 20 opens only the first outlet 21b to which the first cooling jet line 24a is connected. It is in the rotation position (state of Fig. 8A).

Of course, the ECU 10 controls the step motor 23 by determining when the engine 1 is cold by the respective sensing elements and the pistons 1 and 4 of the cylinder 1 are in the top dead center position. While the motor 23 is drive controlled, the rotational position of the supply control panel 22 is controlled to a predetermined position (position (a) of FIG. 8).

In addition, the second cooling jet line 25a connected through the branch lines 24b and 25b to the oil jets 30 installed in the second and third cylinders so that the engine oil is injected into the second and third cylinders. The oil must be supplied to the state ((b) of FIG. 9), and the supply control panel 22 of the electronic control valve 20 opens only the second outlet 21c to which the second cooling jet line 25a is connected. It is in the rotation position (state of Fig. 8B).

In this way, since the oil should be supplied only through one of the two cooling jet lines 24a and 25a, the supply control panel 22 may be any one selected from the first outlet 21b and the second outlet 21c of the housing 21. Only one should be opened, so that when the engine oil is injected into cylinders 1 and 4, oil injection is blocked in cylinders 2 and 3, and on the contrary, the engine oil is injected into cylinders 2 and 3. In the 1st and 4th cylinders, the oil injection is blocked.

And, as shown in (c) of FIG. 10, the ECU 10 is an electronic control valve because an operation of the piston cooling jet is unnecessary in order to prevent oil pressure loss and reduce oil consumption during the engine warm low load where all oil injection is stopped. The internal flow path is shut off by controlling the control unit 20 (second operation mode). At this time, the electronic control valve 20 supplies the oil to the first cooling jet line 24a and the second cooling jet line 25a. All of them should be shut off (the state (c) of FIG. 9), and the supply control panel 22 of the electronic control valve 20 is in a rotational position that closes both the first outlet portion 21b and the second outlet portion 21c. (State (c) of FIG. 8).

And, as shown in Fig. 10 (d), when the engine at high rotation / high load to inject the engine oil in all cylinders, it is necessary to simultaneously spray a large amount of engine oil into each cylinder for cooling the piston (1), ECU 10 controls the electronic control valve 20 to open all the internal flow paths (third operation mode), in which case the first cooling jet line 24a and the second cooling jet line are controlled by the electronic control valve 20. All of the oil must be supplied to (25a) (d) in FIG. 9, and the supply control panel 22 of the electronic control valve 20 has both the first outlet portion 21b and the second outlet portion 21c. It is in the rotational position to open (state of Fig. 8 (d)).

As described above, in the piston cooling jet apparatus according to the present invention, the ECU 10 outputs a control signal according to the engine state based on the signal of each sensing element, and the electronic control valve 20 according to the control signal output from the ECU 10. Is controlled, the engine oil supplied from the main oil gallery (4) via the oil supply line (5) is one of both cooling jet lines (24a, 25a) or selected one of the two cooling jet lines (24a, 25a). While selectively supplied, the third operation mode of the electric cylinder injection or the first operation mode of the partial cylinder injection in which only the cylinder in which the piston 1 is in the top dead center position is selectively performed.

Of course, in the engine state such as low engine warm load, the second operation mode in which oil injection of all cylinders is stopped is performed.

11 shows an example of mode conversion for variable control of a variable piston cooling jet according to the present invention, and shows an example in which an operation mode is converted according to a reference speed and a reference temperature obtained through experiments. .

That is, in the low rotation mode where the engine speed becomes less than the reference rotation speed, the second operation mode stops oil injection in all cylinders, and in the high rotation mode higher than the reference rotation speed, the operation mode changes to the third operation mode in which oil is injected into the cylinder. You can do that.

In addition, in order to reduce the piston slab and piston scuffing that occur at low temperature of the engine, the oil supply is effective, but the effect decreases as the oil temperature increases, so if the piston 1 is lower than the reference temperature, the top dead center The first operation mode in which oil is injected only in the cylinder in the position, and when the temperature is above the reference temperature, the operation can be switched to the second operation mode in which the oil injection of all cylinders is stopped.

As shown the mode change process according to the number 12 is rotated based on attachment and a reference temperature a flow chart, the number of current engine speed (RPM) is in the third operating mode is higher than the reference rotation speed (RPM _mode), engine speed (RPM ) Is below the reference speed (RPM _mode ) and the oil temperature (Toil) is above the reference temperature (Toil _mode ), the engine operating speed (RPM) is below the reference speed (RPM _mode ) and the oil temperature ( If Toil) is less than the reference temperature (Toil _mode ) shows an example of switching to the second operating mode.

As described above, according to the variable piston cooling jet device for automobiles according to the present invention, instead of the conventional mechanical check valve that is opened and closed by the oil pressure of the main oil gallery, the electronic control valve is opened and closed by the control signal of the ECU By means of this, oil injection is possible in each operating mode set according to the engine condition, especially in the cylinder where the piston is in the top dead center position to prevent piston scuffing and piston slab noise, especially in the initial start and engine cold zones. In the high rotation / high load area of the engine where piston cooling is required due to the large piston heat load, oil is injected into the entire cylinder regardless of the position of the piston. Unnecessary oil as oil injection control is possible with optimum operating mode Injection can be prevented.

In this way, it is possible to prevent unnecessary oil injection, to prevent the reduction of the overall oil pressure and increase the oil consumption, and to prevent fuel overheating and exhaust gas deterioration by preventing the piston overcooling due to unnecessary oil injection during cold. .

Claims (7)

An oil jet installed in each cylinder of the engine and connected to each of the following electronic control valves through a cooling jet line to inject engine oil supplied through the following electronic control valve and the cooling jet line for piston cooling; An ECU which receives a signal of a sensing element in which a vehicle is installed and outputs a control signal for each operation mode set according to an engine state; The engine oil is supplied through the oil supply line connected from the main oil gallery, and driven and controlled by a control signal for each operation mode according to the engine state output from the ECU, so that the supplied engine oil is selected cooling jet line and the final oil connected thereto. An electronic control valve in which an internal flow path connected to each cooling jet line is selectively opened to be supplied to the jet; Variable piston cooling jet device for a vehicle comprising a. The method according to claim 1, The electronic control valve, A housing having an inlet portion to which the oil supply line is connected, and a plurality of outlet portions to which the cooling jet line is connected; A supply control panel having a plurality of flow path holes for opening the outlet and rotatably embedded in the housing to close or open all of the plurality of outlets or to open only a selected portion according to a rotation position; A step motor rotating the supply control panel while being driven and controlled by a control signal output from the ECU; Variable piston cooling jet device for a vehicle comprising a. The method according to claim 2, The cooling jet line is connected to a plurality of oil jets through branch lines, so that the electronic control valve is driven and controlled by the control signal output from the ECU so that engine oil can be simultaneously injected in the plurality of engine cylinders. A variable piston cooling jet device for an automobile. The method according to any one of claims 1 to 3, The ECU controls the electronic control valve so that oil is supplied to the oil jet of the cylinder when the piston of each engine cylinder is in the top dead center position when it is determined that the initial start of the engine and the engine cold start are based on the signal input from the sensing element. Variable piston cooling jet device for a vehicle, characterized in that for outputting a control signal. The method according to any one of claims 1 to 3, The ECU outputs a control signal for controlling the electronic control valve to block all internal flow paths connected to the cooling jet line to block engine electric oil injection when the engine warm low load is determined based on a signal input from a sensing element. A variable piston cooling jet device for an automobile. The method according to any one of claims 1 to 3, The ECU controls the electronic control valve to open all the internal flow paths connected to the cooling jet line for the engine electric oil injection when the engine determines the high rotation / high load based on a signal input from the sensing element. Variable cooling jet device. The method according to claim 1, Wherein each of the oil jets has a nozzle direction set to inject engine oil between the piston and the bore in the cylinder.

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