JP2007138760A - Engine lubrication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine lubrication system reducing bubbling of oil and air suction in an engine equipped with a two-sump type oil pan and a balance shaft. <P>SOLUTION: The engine lubrication system (1) comprises a gear pump (8) formed of driven gears (9a, 9b) enclosed by a case (10) having an oil suction opening (10a), which drive gears are installed on a pair of balance shafts (9) driven by a drive gear (12a) installed on a crankshaft (12), the oil pan (3), and an oil pan separator disposed in the oil pan (3) and dividing an interior into a first chamber (6) and a second chamber (7), wherein the gear pump (8) is received in the first chamber (6). In such an operation state that oil in the first chamber (6) is bubbled, an electromagnetic clutch (16) is engaged and oil is sucked up from the second chamber (7) by an oil pump (15). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an engine lubrication device that supplies oil to various parts of an engine lubrication from within an oil pan (two tank type oil pan) partitioned into a first chamber and a second chamber by an oil pan separator.

  Conventionally, engine oil has been used for engine lubrication and cooling. This engine oil is stored in an oil pan provided in the lower part of the engine, and is circulated to each part of the engine by an oil pump. The engine oil that has circulated through each part of the engine is dripped into the lower oil pan. And the engine oil dripped in the oil pan is circulated to each part of the engine again by the oil pump. During this time, the engine oil receives heat from each part of the engine and cools each part. The engine oil also has a role of forming an oil film in each part of the engine to promote lubrication between the parts and preventing oxidation of the parts.

  Here, immediately after the cold start of the engine, the engine oil stored in the oil pan is cold, the viscosity is high, and it is not in a state suitable for circulating each part of the engine and lubricating each part. Therefore, immediately after the cold start, it is desired to raise the temperature of the engine oil as soon as possible so that it has an appropriate viscosity. For this purpose, the oil pan is divided into a plurality of compartments, and immediately after the cold start, the engine oil in one compartment is easily circulated, and the engine oil in this compartment is heated earlier, After warming-up is complete, it has already been studied to avoid overheating of the engine oil and make the engine oil in a preferable state (Patent Document 1). Such an early temperature rise of engine oil contributes to an improvement in fuel efficiency due to an early reduction of friction, and an improvement is also desired from the recent strong demand for an improvement in fuel efficiency.

  FIG. 4 is a cross-sectional view for explaining the structure of the oil pan 50 described in Patent Document 1. In order to effectively increase the temperature of the engine oil, the oil pan separator 51 having the recess 51a is placed in the oil pan 52. The strainer 53 is disposed so that the engine oil suction port 53a is positioned in the recess 51a, and communication holes 54 and 55 are provided in the upper and lower portions of the side wall 51a1 of the recess 51a to communicate the inside and outside of the recess 51a. The configuration is adopted. Among the communication holes 54 and 55, the communication hole 55 provided in the lower part of the side wall 51a1 of the recess 51a controls the circulation of the engine oil inside and outside the recess 51a using the viscosity change of the engine oil. Yes. That is, the diameter of the communication hole 55 is set to a small diameter, and the engine oil having a high viscosity during warm-up prevents the mixing of the engine oil inside and outside the recess 51a by utilizing the large oil resistance when passing through the communication hole 55. On the other hand, low-viscosity engine oil after completion of warm-up can pass through the communication hole 55, and the engine oil inside and outside the recess 51a is mixed. If the engine oil is mixed inside and outside the recess 51a, the temperature of the engine oil inside the recess 51a that has become hot can be lowered by the oil outside the recess 51a at a low temperature.

  On the other hand, the communication hole 54 provided in the upper part of the side wall 51a1 of the recess 51a can circulate the engine oil inside and outside the recess 51a regardless of the viscosity of the engine oil. The engine oil dropped into the pan separator 51 (inside the recess 51a) is caused to flow from the inside to the outside of the recess 51a of the oil pan separator 51. Therefore, as shown by an arrow 57, an engine oil circulation path is formed in which the engine oil flowing out from the upper portion of the recess 51a flows again into the recess 51a from the lower portion of the recess 51a according to the viscosity of the engine oil. It is designed to promote engine oil mixing and cool engine oil. The mixed engine oil is sucked up from the suction port 53a and supplied into the engine block 56 from above.

  On the other hand, some engines include a driven gear and a pair of balance shafts that are driven by a drive gear attached to a crankshaft. FIG. 5 is an exploded perspective view showing an example of the configuration of the balance shaft. Each balance shaft 60 has an unbalance weight 60a that is biased to one side. A first driven gear 60d is attached to one balance shaft 60, and a second driven gear 60e that meshes with the first driven gear 60d is attached to the other balance shaft 60. The balance shaft 60 is mounted on the bearing portion 60c, and a drive gear 62a that meshes with the first driven gear 60d is mounted on the crankshaft 62 that is supported by the housing 60b. When the first driven gear 60d rotates with the rotation of the drive gear 62a of the crankshaft 62, the second driven gear 60e meshing with the first driven gear 60d rotates in the opposite direction to the first driven gear 60d. The balance shaft 60 cancels the secondary inertia force generated by the rotation of the crankshaft 62 by performing such an operation.

JP 2003-222012 A

  The balance shaft 60 as described above may be installed in an engine to which the oil pan 50 of Patent Document 1 is attached. In this case, the balance shaft 60 driven by the crankshaft 62 is the oil pan separator 51. It will be accommodated in the recess 51a.

  However, if the balance shaft 60 is housed in the recess 51a in this way, the following inconvenience may occur. That is, if the unbalance weight 60a rotates in the recess 51a in which the suction port 53a of the strainer 53 is arranged, the oil surface in the recess 51a is struck to cause the oil to foam, and the strainer 53 may cause air to be sucked. Such a fear increases particularly when the engine is in a high load and high rotation state. Inhalation of air is a cause of poor lubrication and should be eliminated as much as possible. However, in a so-called two-tank oil pan such as the oil pan 50, the volume of the recess 51a tends to be low. 60a becomes close to the oil level or is soaked and oil is easily bubbled.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine lubrication device capable of reducing foaming of oil and consequently suction of air in an engine including a two-tank oil pan and a balance shaft.

  In order to achieve this object, an engine lubrication device of the present invention covers a driven gear mounted on each of a pair of balance shafts driven by a drive gear mounted on a crankshaft with a case having an oil suction port. A gear pump configured, an oil pan attached to the lower part of the engine block, and an oil pan separator disposed in the oil pan and partitioning the oil pan into a first chamber and a second chamber, One chamber communicates with the interior of the engine block and houses the gear pump (claim 1). By adopting such a configuration, the oil in the first chamber of the two-tank type oil pan partitioned by the oil pan separator in the oil pan is not an oil pump, but a gear pump that uses a driven gear that is used to drive a balance shaft. Can be sucked up. That is, it can be set as the structure which does not arrange | position the inlet of a strainer in a 1st chamber. The second chamber is preferably arranged so as to cover the periphery of the first chamber.

  In such an engine lubrication device, a strainer in which a suction port is arranged in the second chamber, an oil pump that sucks oil in the second chamber from the suction port of the strainer, and a first oil that sucks oil from the first chamber A suction path, a second oil suction path for sucking oil from the second chamber, and an oil suction path switching means for switching between the first oil suction path and the second oil suction path. It can be set as a structure (Claim 2). With such a configuration, by switching the oil suction route by the oil suction route switching means, for example, at the time of high engine load, high rotation, etc., the second chamber disposed outside the first chamber on the outside Oil can be actively sucked from. The oil in the second chamber, which does not contain the balance shaft, avoids the inhalation of air without causing oil bubbling due to the unbalanced weight hitting the oil surface even when the engine is heavily loaded and running at high speed. be able to.

  In such an engine lubrication device, the oil suction path switching means may be an electromagnetic clutch that turns on and off the drive of the oil pump. If you install an electromagnetic clutch on the drive shaft of the oil pump and want to suck up oil from the second chamber, connect this electromagnetic clutch and drive the oil pump. can do. In short, the oil suction path switching means is only required to be able to switch the oil suction path according to the operating condition of the engine. Therefore, the oil suction path switching means can be an electric oil pump capable of driving and controlling the oil pump, or the second oil suction path switching means. It is also possible to use a relief valve installed on the route that can be opened and closed. For example, when the relief valve is an electromagnetic relief valve and you want to stop sucking up oil from the second chamber, the oil released by the oil pump is released by opening the electromagnetic relief valve. It is possible to prevent oil from being sent.

  The oil suction path switching means may be a three-way valve installed at the junction of the first oil suction path and the second oil suction path (Claim 5). By switching the three-way valve, oil can be sucked from either chamber and sent to each part of the engine lubrication. Moreover, if it is set as the structure which mounted | wore with such a three-way valve, it can eliminate that oil flows back through the 1st oil suction path. In other words, there is a concern that oil may flow into the first oil suction path (backflow) when the operating condition is such that the oil pumping capacity of the oil pump exceeds the oil pumping capacity of the gear pump, but the three-way valve is switched. Thus, such a back flow of oil can be eliminated.

  When the three-way valve is installed in this way, when the oil suction from the first chamber is cut off, the oil pressure of the oil that has lost its place in the first oil suction path increases, and the drive resistance of the gear pump It is possible to become. Therefore, it is desirable that a relief valve be installed in the first oil suction path together with the three-way valve (claim 6).

  According to the present invention, by a gear pump configured by covering a driven gear attached to each of a pair of balance shafts driven by a drive gear attached to a crankshaft of a two-tank oil pan with a case having an oil suction port. While sucking up oil in the first chamber that communicates with the inside of the engine block and sucking in oil from the second chamber by the strainer according to the operating situation, try not to suck up foamy oil in the first chamber as much as possible, Air mixing can be avoided. In addition, since a two-tank oil pan is used, early warm-up can be achieved by circulating the oil in the first chamber that has a small capacity and is covered by the second chamber when warming up. Appropriate oil circulation can be realized by circulating oil in the second chamber having a low temperature.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  First, the engine lubrication apparatus 1 of the present invention will be described. FIG. 1 is a cross-sectional view illustrating a schematic configuration of a two-tank oil pan 2 equipped with a lubricating device 1. The two-tank oil pan 2 is provided with an oil pan separator 4 having a recess 4 a inside the oil pan 3. The oil pan 3 is attached to the lower part of the engine block 5, and the recess 4 a of the oil pan separator 4 forms a first chamber 6 that communicates with the interior of the engine block 5. That is, the oil pan 3 is partitioned into a first chamber 6 and a second chamber 7 by an oil pan separator 4.

  The side wall 4a1 of the recess 4a is provided with a first series of through holes 20 that allow the first chamber 5 and the second chamber 6 to communicate with each other. This first series of through holes 20 is preferably provided as high as possible on the side wall 4a1 of the recess 4a. In the two-tank oil pan 2 of this embodiment, the amount of oil stored in the first chamber 5 and the second chamber 6 is It is provided near the lower limit level. Further, a second communication hole 21 for controlling the flow of oil between the first chamber 5 and the second chamber 6 using a change in the viscosity of the oil is provided at the lower portion of the side wall 4a1 of the recess 4a.

  A gear pump 8 is accommodated in the first chamber 6. The gear pump 8 is configured by covering a first driven gear 9a and a second driven gear 9b mounted on each of a pair of balance shafts 9 with a case 10 having an oil suction port 10a. In such a case 10, a first oil suction path 11 for sucking oil from the first chamber is formed. Each of the pair of balance shafts 9 includes an unbalance weight. The first driven gear 9a mounted on one balance shaft meshes with the drive gear 12a mounted on the crankshaft 12, and rotates as the engine starts and the crankshaft 12 rotates. In addition, the driven gear 9b attached to the other balance shaft meshes only with the driven gear 9a. For this reason, the first driven gear 9a and the second driven gear 9b rotate in opposite directions. As described above, the first driven gear 9a and the second driven gear 9b rotate in the opposite directions, whereby the oil in the first chamber 6 is sucked up from the oil suction port 10a and sent to the first oil suction path 11.

On the other hand, a suction port 13 a of the strainer 13 is disposed in the second chamber 7. A second oil wicking path 14 is formed in the strainer 13, and an oil pump 15 is installed on the second oil wicking path 14. The oil pump 15 is driven by the crankshaft 12, but includes an electromagnetic clutch 16, and oil supply from the oil pump 15 can be controlled by turning on and off the electromagnetic clutch 16. In order to perform such control, the ECU 17 is connected to the electromagnetic clutch 16. The ECU 17 is connected to a hydraulic pressure sensor 18 for acquiring hydraulic pressure for controlling the electromagnetic clutch 16 and a sensor group 19 for acquiring various other data such as water temperature and accelerator opening.
The second oil suction path 14 joins the first oil suction path 11 downstream of the oil pump 15.

  Hereinafter, the operation of the lubricating device 1 configured as described above will be described. First, when the engine is started in the cold state, when the crankshaft 12 rotates, the first driven gear 9a meshed with the drive gear 12a and further the second driven gear 9b meshed with the first driven gear 9a start to rotate. As a result, the oil in the first chamber 6 is sucked up from the oil suction port 10a of the gear pump 8, sent to the first oil suction path 11, and supplied to each part of the engine lubrication. On the other hand, when it is determined from the data such as the water temperature from the sensor group 19 that the ECU 17 is in a cold state, and it is determined that the engine is not at a high load and high speed based on the data such as the accelerator opening. The electromagnetic clutch 16 is disconnected by a command from the ECU 17. As a result, the oil pump 15 is not driven, and no oil is sucked up from the second chamber 7.

Since the lubrication apparatus 1 operates as described above from the cold start to the completion of warm-up, oil is supplied to each part of the engine lubrication only from the first chamber 6. Since the amount of oil in the first chamber 6 is small, it is possible to raise the temperature quickly and to improve fuel efficiency. Note that the oil level is not struck violently by the unbalanced weight of the balance shaft when warming up and high rotation is not used, so there is little risk of oil bubbling and air inhalation.
In this way, the electromagnetic clutch 16 is disengaged during warm-up, and the oil pump 15 is not driven, but the ECU 17 detects a state in which the hydraulic pressure has decreased based on data from the hydraulic sensor 18. Then, the electromagnetic clutch 16 is connected and the oil pump 15 is driven to start supplying oil from the second chamber 7. Thereby, it is possible to avoid poor lubrication in each part of the engine lubrication.

  On the other hand, after the warm-up is completed or when the engine is operated under a high load and high rotation state, and the amount of oil is insufficient with only the oil in the first chamber 6, the ECU 17 switches to the electromagnetic clutch 16. A command is issued, the clutch is engaged, and the oil pump 15 is driven. When the engine is operated under a high load and high rotation state, the oil level of the oil in the first chamber 6 may be beaten and foamed by the unbalanced weight, but by sufficiently sucking up the oil from the second chamber 7 Lubrication failure in each part of the engine lubrication can be avoided.

  Thus, according to the present invention, early warm-up can be achieved by using the two-tank oil pan 2. Further, the problem of oil bubbling caused by the unbalanced weight of the balance shaft 9 mounted to reduce vibrations hitting the oil surface and the accompanying air suction can be solved.

  Next, a second embodiment of the present invention will be described with reference to FIG. The lubrication device 30 of the second embodiment is different from the lubrication device 1 of the first embodiment in that the lubrication device 30 of the second embodiment replaces the electromagnetic clutch 16 in the lubrication device 1 of the first embodiment and is downstream of the oil pump 15. The electromagnetic relief valve 31 is installed upstream of the junction of the first oil suction path 11 and the second oil suction path 14. As a result, the oil pump 15 is always driven when the engine is operating. The electromagnetic relief valve 31 is controlled to open by the ECU 17. The electromagnetic relief valve 31 is opened during cold start and during warm-up. Accordingly, the oil sucked up by the oil pump 15 from the second chamber 7 is released into the second chamber 7, and only the oil in the first chamber 6 is supplied to each part of the engine lubrication. As a result, as in the case of the first embodiment, a small amount of oil in the first chamber 6 circulates during the warming up in the cold state, so that the early warming up is possible.

  On the other hand, after the warm-up is completed or when the engine is operated under a high load and high rotation state, and the amount of oil is insufficient with only the oil in the first chamber 6, the ECU 17 performs the electromagnetic relief valve 31. To close the valve. Thereby, the oil sucked up by the oil pump 15 is supplied to each part of the engine lubrication through the second oil suction path 14.

  Since other configurations are the same as those in the first embodiment, the same components are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted.

  Next, Embodiment 3 of the present invention will be described with reference to FIG. The lubrication device 40 of the third embodiment is different from the lubrication device 1 of the first embodiment in that the lubrication device 40 of the third embodiment replaces the electromagnetic clutch 16 in the lubrication device 1 of the first embodiment with the first oil suction path 11. The three-way valve 41 installed at the junction with the second oil suction path 13 and the relief valve 42 installed on the first oil suction path 11 are used. The three-way valve 41 is connected to the ECU 17. The relief valve 42 is of a type that is opened when a predetermined pressure P is reached.

  In the lubricating device 40 having such a configuration, at the time of cold start and during warm-up, the three-way valve 41 is switched to allow the oil flow in the first oil suction path 11 according to a command from the ECU 17. On the other hand, after the warm-up is completed, switching is performed so as to allow the oil flow in the second oil suction path 14 according to a command from the ECU 17. By switching the oil suction path by switching the three-way valve 41 in this way, the first oil suction path 11 and the second oil suction path are caused by the difference in suction capacity between the oil pump 15 and the gear pump 8. Even if the hydraulic pressure in the upper path 14 is generated, the backflow of oil can be prevented.

  Further, since the gear pump 8 is always driven while the engine is running, when the oil flow in the first oil suction path 11 is interrupted, the hydraulic pressure in the first oil suction path 11 increases, and the balance shaft Although this may result in a rotational resistance of 9, which may impair the operation efficiency of the engine, when the oil pressure in the first oil suction path 11 reaches a predetermined pressure P, the relief valve 42 opens and the oil pressure decreases. So this situation can be avoided.

  Since other configurations are the same as those in the first embodiment, the same components are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.

It is sectional drawing explaining schematic structure of the 2 tank type oil pan equipped with the lubricating device of Example 1. FIG. It is sectional drawing explaining schematic structure of the 2 tank type oil pan equipped with the lubricating device of Example 2. FIG. It is sectional drawing explaining schematic structure of the 2 tank type oil pan equipped with the lubricating device of Example 3. FIG. It is sectional drawing which shows schematic structure of the conventional 2 tank type oil pan. It is a disassembled perspective view which shows the structure of a balance shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 30, 40 Lubrication device 2 Two tank type oil pan 3 Oil pan 4 Oil pan separator 4a Recess 4a1 Side wall 5 Engine block 6 First chamber 7 Second chamber 8 Gear pump 9 Balance shaft 9a First driven gear 9b Second driven gear 10 Case 10a Oil Suction Port 11 First Oil Suction Path 12 Crankshaft 12a Drive Gear 13 Strainer 13a Suction Port 14 Second Oil Suction Path 15 Oil Pump 16 Electromagnetic Clutch 17 ECU
18 Pressure sensor 19 Sensor group

Claims (6)

A gear pump configured by covering a driven gear mounted on each of a pair of balance shafts driven by a drive gear mounted on a crankshaft with a case having an oil suction port;
An oil pan attached to the lower part of the engine block;
An oil pan separator disposed in the oil pan and partitioning the oil pan into a first chamber and a second chamber;
The first chamber is in communication with the interior of the engine block and houses the gear pump. The engine lubrication device according to claim 1,
A strainer having a suction port disposed in the second chamber;
An oil pump for sucking up oil in the second chamber from the suction port of the strainer;
A first oil suction path for sucking oil from the first chamber;
A second oil suction path for sucking oil from the second chamber;
Oil suction path switching means for switching between the first oil suction path and the second oil suction path;
An engine lubrication device comprising: The engine lubrication device according to claim 2,
The engine lubrication device according to claim 1, wherein the oil suction path switching means is an electromagnetic clutch for turning on and off the driving of the oil pump. The engine lubrication device according to claim 2,
The engine lubrication device, wherein the oil suction path switching means is a relief valve installed on the second oil suction path. The engine lubrication device according to claim 2,
The engine oil lubrication path switching means is a three-way valve installed at a junction of the first oil suction path and the second oil suction path. The engine lubrication device according to claim 5, wherein
An engine lubrication device comprising a relief valve installed in the first oil suction path.

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