JPH0821239A - Piston cooling controller of engine - Google Patents

Abstract

PURPOSE:To improve all performance of an engine by securing oil pressure in the low rotational range as well as positively cooling a piston of the engine by oil. CONSTITUTION:An oil temperature sensor 40 for detecting the temperature of oil is provided, and an oil check valve 36 is provided between a main gallery 16 and a piston cooling oil passage 30, and a control means 38 for controlling supply or stop of oil to the piston through a process of operating the oil check valve 36 by the state of the oil temperature detected by the oil temperature sensor 40 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston cooling control device for an engine, and more particularly to positively cooling the piston with oil and securing hydraulic pressure in a low rotation range to improve various performances of the engine. The present invention relates to an engine piston cooling control device.

[0002]

2. Description of the Related Art In a vehicle engine, oil is circulated in order to lubricate various parts such as a valve operating mechanism of a cylinder head and to cool each part such as a piston.

That is, as shown in FIGS.
02 is the cylinder block 104 and the cylinder head 10.
6, cylinder 108, piston 110, connecting rod 11
2, crankshaft 114, cam shaft 116, valve mechanism 118
It has a cylinder head cover 120 and an oil pan 122.

In the engine 102,
As shown in FIG. 9, the oil in the oil pan 122 is sucked by the oil pump 126 through the oil strainer 124, and is pressure-fed to the main gallery 130 formed in the cylinder block 104 through the oil filter 128, and then the oil jet. Valve operating mechanism 11 via 132
8 is supplied to each of the parts 134 for lubrication, and the crank journal bearing 136 of the crankshaft 114 is provided.
And the piston 1 through the large end 138 of the connecting rod 112.
10 is supplied to the piston pin and the inner wall 140 of the cylinder sleeve, and is also supplied to the piston cooling oil passage 142 formed in the cylinder block 104, and the piston jet nozzle 146 and the back side portion 148 of the piston 110 are supplied via the relief valve 144. Then, it is supplied to the above-mentioned piston pin and the inner wall 140 of the sealing sleeve. That is, as a measure for increasing the rotation speed and output of the engine 102, the temperature of the piston 110 is lowered by directly spraying the oil on the back side portion of the piston 110.

Further, as shown in FIG. 11, the piston 110
If the cooled oil is returned to the oil pan 122 at a high temperature, the oil temperature becomes very high. Therefore, in order to prevent this, the oil cooler 15 is provided in the middle of the oil passage.
0 is provided.

Further, such a cooling control device for a piston is disclosed in, for example, JP-A-6-42346 and JP-A-4-318215. JP-A-6
No. 42346 discloses an oil jet mechanism that injects lubricating oil toward the lower surface side of a piston, and an on-off valve that stops lubricating oil injection from the oil jet mechanism.
An operating state detecting means for detecting an engine operating state including at least the catalyst temperature of the exhaust system, and a control means for opening and closing the on-off valve when the catalyst temperature becomes equal to or higher than the catalyst activation temperature based on the engine operating state, As a result, the supercooling of the piston is suppressed when the engine is in a cold state, particularly when the catalyst has not reached the activation temperature, and an increase in the amount of HC discharged is avoided. What is described in Japanese Patent Laid-Open No. 4-318215 is
A first control valve that adjusts the amount of oil supplied to a liner oil supply oil gallery that communicates with the cooling oil groove on the outer peripheral surface of the cylinder liner, and an oil jet gallery that communicates with an oil jet that injects cooling oil on the inner surface of the piston. A second control valve for adjusting the amount of oil supplied to the
Also, the oil amount of the second control valve is controlled according to the operating state of the engine.

[0007]

However, in the conventional piston cooling control device, since the control is not performed so that the optimum piston temperature that matches the operating conditions of the engine is not performed, the viscosity at low temperature is not controlled. If high oil is supplied, the mechanical loss (mechanical loss) increases, which deteriorates the startability of the engine.

Further, if oil of low viscosity at high temperature is supplied, the oil pressure is lowered in the low engine speed region, and there is a problem that seizure of the engine is caused.

Further, in cooling the piston, the oil is heated to a high temperature, so that an auxiliary machine such as an oil cooler is required, resulting in a complicated structure and an increase in cost.

Further, in each of the above-mentioned publications, in consideration of reduction of HC and reduction of mechanical loss (mechanical loss), whether or not the piston is cooled is controlled by electric control. Since the (factor) is obtained from various sensors such as a hydraulic pressure sensor, an oil temperature sensor, and a catalyst temperature sensor, there is a disadvantage that a large number of sensors are required.

Further, if the cooling of the piston is controlled by the catalyst temperature, depending on the layout of the vehicle body, the position of the engine and the catalyst may be greatly changed depending on whether they are close to each other. It cannot be said that this is a reliable method for knowing the state, and there was the inconvenience of losing the superiority of the piston. Therefore, the cooling of the piston controlled by the map of the low speed region, the medium speed region, the high speed region of the engine and the catalyst temperature greatly varies depending on the layout of the exhaust system, which causes the inconvenience of uneven combustion.

Furthermore, when the piston cooling is controlled by the engine speed, the engine load and the oil temperature from the oil temperature sensor, the logic capacity in the control means (ECM) increases due to an increase in the number of calculation items. There was an inconvenience that it was disadvantageous in terms of cost.

[0013]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention firstly provides a main gallery for circulating oil in a cylinder block of an engine, and a piston cooling which communicates with the main gallery. An oil passage for the engine is provided in the cylinder block, and a piston cooling control device for an engine that controls cooling of the piston by oil from the main gallery and the oil passage for piston cooling is provided with an oil temperature sensor for detecting the temperature of the oil. An oil check valve is provided between the main gallery and the piston cooling oil passage, and a control means for controlling the oil supply to the piston by operating the oil check valve at least according to the oil temperature state detected by the oil temperature sensor is provided. It is characterized by being provided.

Secondly, the control means actuates the oil check valve in accordance with the oil temperature state detected by the oil temperature sensor and the exhaust temperature state of the engine detected by the exhaust temperature sensor to remove oil to the piston. It is characterized by controlling the supply and disconnection.

Thirdly, the control means operates the oil check valve according to the oil temperature state detected by the oil temperature sensor and the throttle opening state of the throttle valve detected by the throttle opening sensor to operate the oil check valve. It is characterized by controlling the supply and disconnection of oil.

Fourthly, the control means operates the oil check valve according to the oil temperature state detected by the oil temperature sensor and the intake pipe pressure state of the engine detected by the intake pressure sensor to operate the oil to the piston. It is characterized in that the power supply is cut off.

[0017]

According to the structure of the present invention, since the oil to the piston is cut off at least depending on the oil temperature state,
It is possible to stop the piston cooling in the operating range when the viscosity of the oil at low oil temperature and high oil temperature is extreme, and while maintaining the superiority of cooling the piston, the hydraulic pressure in the low rotation range is maintained. To secure the piston temperature optimally to improve various engine performance, and to control oil viscosity according to engine operating conditions to improve oil loss and reduce mechanical loss. An auxiliary machine such as an oil cooler is not required, and a large number of sensors are not required, which can prevent an increase in cost.

[0018]

Embodiments of the present invention will be described in detail and specifically with reference to the drawings. 1 to 4 show a first embodiment of the present invention. In FIG. 2, 2 is an engine mounted on a vehicle (not shown), 4 is a cylinder block,
6 is a cylinder.

In this engine 2, as shown in FIG. 1, the oil in the oil pump 8 is the oil strainer 1
0 is sucked by the oil pump 12 and is then pressure-fed to the main gallery 16 formed in the cylinder block 4 via the oil filter 14, and then the oil jet 1
8 to supply each component of the valve mechanism 20 installed in the cylinder head (not shown) to perform lubrication, and the crank journal bearing 2 of the crankshaft (not shown).
2 and the large end of the connecting rod 24, and is supplied to the piston pin of the piston (not shown) and the cylinder sleeve inner wall 26.

Further, as shown in FIG. 2, in the cylinder block 4, a piston cooling oil passage 30 is formed in the main gallery 16 via a connecting oil passage 28.
Main gallery 16 to piston cooling oil passage 30
The oil that has reached the above state is supplied to the above-mentioned piston pin and the cylinder sleeve inner wall 26 via the piston jet nozzle 32 and the back side portion 34 of the piston.

By the way, in this embodiment, as shown in FIG.
As shown in FIG. 2, an oil check valve (solenoid valve) 36 that is electrically on / off controlled to open / close the communication oil passage 28 is provided in the communication oil passage 28 between the main gallery 16 and the piston cooling oil passage 30. Is provided.

The operation of the oil check valve 36 is controlled (ON / OFF) by a control means (ECM) 38. The control means 38 is attached to the main gallery 16 and is attached to an oil temperature sensor 40 for detecting the temperature of oil during operation of the engine 2 and an inlet portion of an exhaust manifold (not shown) to detect the exhaust temperature. Exhaust temperature sensor 42
Have been contacted. The control means 38 uses the exhaust temperature from the exhaust temperature sensor 42 to calculate the combustion state of the engine instead of the combustion temperature.

As shown in FIG. 3, the control means 38 controls the low oil temperature (oil temperature is less than T ₁ ) and the high oil temperature depending on the relationship between the oil temperature which is the oil temperature and the oil pressure which is the oil pressure. In the operating region where the viscosity of the oil is extreme (the oil temperature is T ₂ or higher) at least, the piston cooling is stopped (cut) at least depending on the oil temperature state, and as shown in FIG. Depending on the condition and exhaust temperature condition,
The oil check valve 36 is operated and controlled.

That is, the area A in FIG. 4 (for example, oil temperature of -30 ° C.
In the region between 20 ° C and exhaust temperature 0 to 500 ° C), the piston temperature is originally low, so cooling of the piston increases mechanical loss (mechanical loss) by directly spraying low-viscosity oil. Engine 2
Therefore, the startability of the engine 2 is improved by suspending (cutting) the cooling of the piston to prevent an increase in mechanical loss.

Further, in the region B of FIG. 4 (for example, oil temperature 100 to 1)
In a range between 50 ° C. and exhaust temperature 0 to 400 ° C., the high temperature and low viscosity oil causes seizure in the engine 2 by promoting a decrease in hydraulic pressure during low rotation and low load operation of the engine 2. Therefore, by stopping (cutting) the cooling of the piston in this B region where the temperature of the piston is decreasing, the decrease in hydraulic pressure is prevented and the occurrence of seizure is avoided.

Further, in the region C of FIG. 4 (regions other than the regions A and B described above), the piston is normally cooled to stabilize combustion.

Next, the operation of the first embodiment will be described.

As shown in FIG. 3, the viscosity of the oil is extremely high or low, such as when the oil temperature is lower than T ₁ and the viscosity of the oil is low, and when the oil temperature is T ₂ or higher and the viscosity of the oil is low. In the operating region of the case, the control means 38 turns off the oil check valve 36, whereby the communication oil passage 28 is closed and cooling of the piston is stopped.

The control means 38, as shown in FIG.
Based on the relationship between the oil temperature and the exhaust temperature, in the region A, the oil check valve 36 is turned off, the cooling of the piston is stopped to prevent an increase in mechanical loss, and the startability of the engine 2 is improved. Also in the region, the oil check valve 36 is turned off to stop the cooling of the piston and prevent the decrease of the hydraulic pressure in the low rotation region to avoid the occurrence of seizure.

On the other hand, the control means 38, as shown in FIG.
In the C range, the oil check valve 36 is turned on, the communication oil passage 28 is opened, the piston is normally cooled, and combustion is stabilized.

As a result, when the temperature is low, the piston is not cooled by the highly viscous oil, so that it is possible to prevent an increase in mechanical loss and improve the startability of the engine 2. Further, since oil having low viscosity is not supplied to the piston at a high temperature, the oil pressure is not reduced in the low engine speed range, and seizure of the engine 2 does not occur. Therefore, while maintaining the superiority by cooling the piston, the hydraulic pressure in the low rotation range can be secured, and the piston can always be held at the optimum temperature, so that various performances of the engine 2 can be improved.

Further, as shown in FIG. 4, since the viscosity of the oil can be controlled by the operating condition of the engine 2, that is, the relation between the oil temperature and the exhaust temperature, the oil loss is improved and the mechanical loss (mechanical loss) is increased. Can be prevented.

Further, it is possible to prevent the temperature of the oil from becoming excessively high, to eliminate the need for auxiliary equipment such as an oil cooler, simplify the construction, and prevent the cost from increasing.

Furthermore, an exhaust temperature sensor 4 equipped with an exhaust temperature comparable to the piston temperature at the inlet of the exhaust manifold.
2 to notify the combustion state of the engine 2 at an early stage, and the presence or absence of cooling of the piston is executed only by the relationship between the exhaust temperature and the oil temperature. It is possible to reduce the cost by eliminating the need for sensors and the like and reducing the number of sensors.

Further, regardless of the combustion state of the engine 2 regardless of the layout of the exhaust system, as a method for immediately determining whether or not the piston is cooled, the exhaust sensor 4 is provided at the inlet of the exhaust manifold.
Since the engine No. 2 is used, the output of the engine 2 can be improved and the occurrence of seizure can be avoided.

Further, since the oil pressure is substantially determined by the level of the oil temperature regardless of the engine speed, it can be controlled by the oil temperature sensor 40 and the engine load or the intake negative pressure. This can prevent an increase in cost without increasing the capacity.

5 and 6 show a second embodiment of the present invention.

In the second embodiment and the following embodiments, the parts having the same functions and functions as those of the first embodiment described above will be designated by the same reference numerals.

The features of the second embodiment are as follows. That is, as shown in FIG. 5, the control means 38 is connected to a throttle opening sensor 52 for detecting the opening state of a throttle valve (not shown), instead of the exhaust temperature sensor of the first embodiment. Are provided.

As described above, the reason why the throttle opening is used instead of the exhaust temperature is that the exhaust temperature tends to be different when the operating state of the engine changes due to weather conditions (temperature, temperature, etc.). Therefore, an error on the boundary line between the on / off state of the oil check valve 36 is likely to occur and the exhaust temperature is considerably high (800-
900 ° C.), there is a disadvantage that the durability of the exhaust gas temperature sensor decreases, so that accurate control can be performed compared to the fluctuation rate of the exhaust gas temperature, and the temperature of the installation position of the throttle opening sensor 52 is low This is because the sex can be improved.

According to the configuration of the second embodiment, the same effect as that of the first embodiment described above is obtained, and the fluctuation rate is small,
Accurately operate the oil check valve 36,
Since the piston is properly cooled and the throttle opening sensor 52 is not exposed to heat, durability can be improved.

7 and 8 show a third embodiment of the present invention.

The features of the third embodiment are as follows. That is, as shown in FIG. 7, the control means 38 is provided with an intake pressure sensor 62 for detecting the intake pipe pressure in communication therewith, instead of the exhaust temperature sensor of the first embodiment described above. The intake pressure sensor 62 is attached to the vehicle body, not the engine 2.

According to the structure of the third embodiment, the same effect as that of the first embodiment is obtained, and since the intake pressure sensor 62 is attached to the vehicle body, it is not directly subjected to the vibration of the engine 2, Further, since the thermal influence is small, the operation control of the oil check valve 36 can be performed with higher accuracy.

[0045]

As is apparent from the above detailed description, according to the present invention, an oil temperature sensor for detecting the temperature of oil is provided, and an oil check valve is provided between the main gallery and the oil passage for cooling the piston, and at least the oil is provided. When the oil viscosity at both low and high oil temperatures is extreme, due to the provision of control means that controls the oil supply to the piston by operating the oil check valve according to the oil temperature detected by the temperature sensor. It is possible to stop the piston cooling in the operating range of the engine, and while maintaining the advantage of cooling the piston, secure the oil pressure in the low rotation range and maintain the piston temperature optimally to improve various engine performance. Improved and also
Controls oil viscosity according to engine operating conditions to improve oil loss, reduce mechanical loss, and eliminate the need for auxiliary equipment such as an oil cooler, as well as the large number of sensors that increase costs. Can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram of a piston cooling control device according to a first embodiment.

FIG. 2 is a schematic view of a cylinder block.

FIG. 3 is a diagram showing a relationship between oil temperature and oil pressure.

FIG. 4 is a diagram showing a cooling region of a piston in the first embodiment.

FIG. 5 is a block diagram of a piston cooling control device according to a second embodiment.

FIG. 6 is a diagram showing a cooling region of a piston in the second embodiment.

FIG. 7 is a block diagram of a piston cooling control device according to a third embodiment.

FIG. 8 is a diagram showing a piston cooling area in the third embodiment.

FIG. 9 is a block diagram of a conventional piston cooling control device.

FIG. 10 is a sectional view of an engine incorporating a conventional piston cooling control device.

FIG. 11 is a schematic configuration diagram of a conventional piston cooling control device.

[Explanation of symbols]

 2 engine 4 cylinder block 8 oil pan 16 main gallery 28 connecting oil passage 30 piston cooling oil passage 36 oil check valve 38 control means 40 oil temperature sensor 42 exhaust temperature sensor

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[Procedure amendment]

[Submission date] August 26, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

Claims (4)

[Claims] 1. A main gallery for circulating oil is provided in a cylinder block of an engine, a piston cooling oil passage communicating with the main gallery is provided in the cylinder block, and oil from the main gallery and the piston cooling oil passage is provided. In a piston cooling control device for an engine that controls cooling of a piston by an oil temperature sensor that detects the temperature of oil, an oil check valve is provided between the main gallery and the piston cooling oil passage, and at least the oil temperature sensor A piston cooling control device for an engine, comprising: a control means for operating the oil check valve according to the detected oil temperature state to control the supply and disconnection of oil to the piston. 2. The control means actuates the oil check valve according to the oil temperature state detected by the oil temperature sensor and the exhaust temperature state of the engine detected by the exhaust temperature sensor to supply or disconnect the oil to the piston. The piston cooling control device for an engine according to claim 1, wherein the piston cooling control device is controlled. 3. The control means actuates the oil check valve according to the oil temperature state detected by the oil temperature sensor and the throttle opening state of the throttle valve detected by the throttle opening sensor to supply oil to the piston. The piston cooling control device for the engine according to claim 1, wherein the supply and disconnection control is performed. 4. The control means operates the oil check valve to supply oil to the piston according to an oil temperature state detected by the oil temperature sensor and an intake pipe pressure state of the engine detected by an intake pressure sensor. The piston cooling control device for the engine according to claim 1, wherein the piston cooling control device controls disconnection.