JP2021156167A - Structure of cooling water pump for internal combustion engine - Google Patents

Abstract

To avoid such a problem that a cooling water pump is wrongly recognized as defective one because the leakage of cooling water is noticeable.SOLUTION: A structure of a cooling water pump includes a pump housing 5 fixed to an internal combustion engine body, a pulley 32 to be rotated following a crankshaft, a rotary shaft 3 connected to the pulley 32 and rotatably supported in the pump housing 5 via a bearing 56, and having an impeller 31 at the end, a seal 52 provided on a site between the impeller 31 and the bearing 56 for suppressing the flow of cooling water from the impeller 31 side to the bearing 56 side, a flow-down passage 59 along which the cooling water leaking through the site where the seal 52 is provided flows down, a first leakage water storage part 50 for storing the cooling water flowing down along the flow-down passage 59, a discharge passage 8 opened in the direction of separating from the pulley 32 for discharging cooling water overflowing from the first leakage water storage part 50, and a second leakage water storage part 21 for storing the cooling water discharged through the discharge passage 8.SELECTED DRAWING: Figure 1

Description

The present invention relates to the structure of a mechanical cooling water pump in a water-cooled internal combustion engine.

Internal combustion engines installed in vehicles, especially four-wheeled vehicles, are generally water-cooled. Therefore, a cooling water pump that sucks in, discharges, and circulates the cooling water of the internal combustion engine is attached to the internal combustion engine.

A mechanical cooling water pump in a widely used internal combustion engine is driven by a crankshaft, which is an output shaft of an internal combustion engine, and rotates by receiving engine torque supplied from the crankshaft. A winding transmission mechanism having a pulley and a belt as elements is interposed between the crankshaft and the rotating shaft of the cooling water pump.

The rotating shaft of the cooling water pump is provided with an impeller for pumping cooling water to its end. The rotating shaft is rotatably supported by a pump housing (body) via bearings. A seal, typically a mechanical seal, is provided between the pump chamber in which the impeller is arranged and the shaft branch chamber in which the bearing is installed to prevent the cooling water in the pump chamber from flowing into the shaft branch chamber.

Sealing of cooling water by a seal is not perfect in reality, and leakage of cooling water from the pump chamber is inevitable. In order to prevent the leaked cooling water from filling the shaft branch chamber and impairing the function of the bearing, the pump housing has a flow-down passage through which the leaked cooling water flows down through a portion provided with a seal in advance, and the flow-down cooling water. A leak reservoir is formed to temporarily store the water.

In a conventional cooling water pump (see, for example, the following patent document), the leak reservoir is open forward toward the pulley. A plug is press-fitted into the opening. The plug is formed with a cylindrical portion that penetrates the plug. When the water level of the cooling water collected in the leaked water reservoir reaches the height of the shaft hole of the cylindrical portion of the plug, the cooling water overflowing from the leaked water reservoir portion is discharged to the outside of the pump housing through the shaft hole. The vapor of the cooling water vaporized in the leak reservoir is also discharged to the outside of the pump housing through the shaft hole of the plug.

JP-A-2019-113034

With a conventional cooling water pump, only a small amount of cooling water can be stored in the leaked water reservoir. Moreover, the shaft hole of the plug attached to the water leakage reservoir is open to the space inside the bowl-shaped pulley.

Therefore, when a certain amount or more of the cooling water leaks through the portion where the seal is provided, the cooling water is discharged from the leaking reservoir into the inner space of the pulley and scattered around by the rotating pulley. Then, the user who opens the hood of the vehicle and visually recognizes the inside of the engine room (engine compartment) will see the scattered cooling water, which is mistaken as an initial failure or failure of the cooling water pump. ..

As a result, the dealer or the maintenance shop will take measures such as replacing the cooling water pump. However, as already mentioned, the leakage of cooling water is an unavoidable event even in a normal cooling water pump without any problems, and wasteful costs are incurred due to originally unnecessary treatment.

An object of the present invention is to avoid a problem that a cooling water pump having no defect is mistaken as having a defect due to a conspicuous leakage of cooling water.

The cooling water pump of an internal combustion engine according to the present invention has a pump housing fixed to the main body of the internal combustion engine, a pulley that rotates in accordance with the crankshaft of the internal combustion engine, and a bearing connected to the pulley and contained in the pump housing. A rotating shaft that is rotatably supported via an impeller and has an impeller at its end, and a portion between the impeller and the bearing that prevents cooling water from flowing from the impeller side to the bearing side. A seal, a flow-down passage through which the cooling water leaked through the portion provided with the seal flows down, a first water leakage reservoir that can store a predetermined amount of cooling water flowing down the flow-down passage, and the first water leakage. It is provided with a discharge passage that is open in a direction away from the pulley for discharging the cooling water overflowing from the reservoir, and a second leak reservoir that can store a predetermined amount of the cooling water discharged through the discharge passage. do.

According to the present invention, it is possible to avoid a problem that a cooling water pump having no defect is mistakenly regarded as having a defect due to a conspicuous leakage of cooling water.

The cross-sectional view which shows the structure of the cooling water pump of the internal combustion engine of one Embodiment of this invention. The figure which shows typically the positional relationship between the discharge passage of the cooling water pump of the same embodiment, the second water leakage reservoir, and the main body of an internal combustion engine.

An embodiment of the present invention will be described with reference to the drawings. The cooling water pump of the internal combustion engine of the present embodiment is a mechanical type that rotates by receiving the supply of engine torque from the crankshaft, which is the output shaft of the internal combustion engine, and sucks, discharges, and circulates the cooling water. A winding transmission mechanism having a pulley 32 and a belt 4 as elements is interposed between the crankshaft and the rotating shaft 3 of the cooling water pump.

As is well known, the main body of an internal combustion engine, which is a 4-stroke reciprocating engine, is a cylinder block 1 containing a cylinder, a cylinder head mounted and fixed on the upper part of the cylinder block 1, and a crank fixed on the lower part of the cylinder block 1. It includes a case, an oil pan, and a front cover (timing chain cover or chain case) 2 attached to the front of the cylinder block 1, the cylinder head, and the crank case. A cylinder head cover is attached to the cylinder head from above.

The cooling water pump is arranged at an intermediate portion in the vertical direction of the front cover 2 and a portion on the left side on the intake side when facing the front cover 2 of the internal combustion engine main body. A pulley 32 is fixed to each of the crankshaft protruding forward from the front cover 2 and the rotating shaft 3 of the cooling water pump, and a belt 4 is wound around the pulley 32 to form a transmission mechanism from the crankshaft. The engine torque can be transmitted to the rotating shaft 3.

The basic structure of the cooling water pump of the present embodiment shown in FIG. 1 largely follows that of the existing one. This cooling water pump is attached to a pump housing (body) 5 fixed to the outer surface of the front cover 2, that is, to the front surface, a substantially bowl-shaped pulley 32 arranged so as to surround the front end portion of the pump housing 5, and the pump housing 5. A rotary shaft 3 to which a pulley 32 is inserted and fixed to its front end and an impeller 31 to its rear end, a seal 52 provided between the impeller 31 and the bearing 56, and a portion where the seal 52 is provided. A flow-down passage 59 for flowing down the cooling water leaking through, a first water leakage reservoir 50 for collecting the cooling water flowing down the flow-down passage 59, and a discharge passage 8 for discharging the cooling water overflowing from the first water leakage reservoir 50. A second leak reservoir 21 for accumulating the cooling water discharged through the discharge passage 8 is provided.

The pulley 32 has a peripheral wall 321 around which the belt 4 is wound, and a front wall 322 connected to the leading edge of the peripheral wall 321. A shaft hole is provided in the central portion of the front wall 322, and the front end portion of the rotating shaft 3 of the cooling water pump is inserted into the shaft hole and fixed. The front wall 322 of the pulley 32 is provided with a through hole 323 for weight reduction.

The impeller 31 is positioned in the pump chamber 6 formed between the front cover 2 of the internal combustion engine main body and the cylinder block 1. A cooling water suction port 7 and a discharge port communicate with the pump chamber 6. The suction port 7 opens rearward along the axial direction of the rotating shaft 3 of the cooling water pump. The discharge port opens in the direction orthogonal to the axial direction of the rotating shaft 3, that is, in the direction orthogonal to the paper surface of FIG. When the impeller 31 rotates around the axis along with the rotating shaft 3, the cooling water of the internal combustion engine is sucked from the suction port 7 and discharged from the discharge port.

In the pump housing 5, a hollow portion chamber 51 connected to the pump chamber 6 and a shaft branch chamber 53 connected to the hollow portion chamber 51 and having a smaller inner diameter are formed. An outer race is fitted in the inner circumference of the shaft support chamber 53, and the rotating shaft 3 is rotatably supported by a bearing 56 held by the outer race.

The seal 52 is installed at the rear end of the shaft branch chamber 53 near the pump chamber 6. The seal 52 is typically a so-called mechanical seal, and plays a role of suppressing the inflow of cooling water from the pump chamber 6 and the cavity chamber 51 into the shaft support chamber 53. Further, a seal ring 55 is also provided on the rear end side of the outer race and the bearing 56 as an auxiliary seal that is in sliding contact with the rotating shaft 3. A buffer (gap) 57 separated along the axial direction of the rotating shaft 3 is opened between the seal ring 55 and the mechanical seal 52. The cooling water leaking from the pump chamber 6 and the cavity chamber 51 through the seal 52 first flows into the buffer 57.

On top of that, a steam vent passage 581 and a leak flow flow passage 59 communicating with the buffer 57 are provided in the pump housing 5. The steam vent passage 581 extends upward or forward and upward away from the axis of the rotating shaft 3, and its upper end is connected to the steam dissipation passage 582 formed in the pump housing 5. The steam dissipation passage 582 extends substantially parallel to the axial direction of the rotating shaft 3 and opens to the front end surface of the pump housing 5. The opening is located in the inner space 324 surrounded by the pulley 32, that is, surrounded by the peripheral wall 321 and the front wall 322 of the pulley 32. The vapor of the cooling water vaporized after leaking through the seal 52 reaches the steam dissipation passage 582 from the buffer 57 via the steam vent passage 581, and is discharged to the outside of the pump housing 5.

The water leakage flow passage 59 extends downward or rearward and downward away from the axis of the rotating shaft 3, and its lower end is connected to the first water leakage reservoir 50 formed in the pump housing 5. The first water leakage reservoir 50 extends substantially parallel to the axial direction of the rotating shaft 3 and opens to the front end surface of the pump housing 5. The opening is located in the space 324 inside the pulley 32.

However, in the present embodiment, the plug 54 is press-fitted into the first water leakage reservoir 50 from the front and attached. The plug 54 does not have a hole through which it penetrates. That is, the opening in front of the first leak reservoir 50 is closed by the plug 54, and the cooling water hardly or not leaks from the opening in front of the first leak reservoir 50. As shown by an arrow in FIG. 1, the cooling water of the liquid phase leaked through the seal 52 flows down from the buffer 57 via the leak flow passage 59, and once reaches the first leak reservoir 50. Accumulate.

The flange portion of the pump housing 5 facing the first water leakage reservoir 50 and the flange portion of the front cover 2 joined to the flange portion are provided with a discharge passage 8 penetrating them. The discharge passage 8 is connected to the first water leakage reservoir 50, extends rearward or rearward and downward away from the pulley 32, and is connected to the second water leakage reservoir 21 located behind the flange portion of the front cover 2. doing. When the cooling water flowing down to the first leak reservoir 50 accumulates up to the height of the discharge passage 8 communicating with the leak reservoir 50, the accumulated cooling water is shown by an arrow in FIG. Is discharged to the second leak reservoir 21 through the discharge passage 8.

FIG. 2 schematically shows the positional relationship between the discharge passage 8 of the cooling water pump and the second water leakage reservoir 21 and the main body of the internal combustion engine. FIG. 2 is also a state in which the discharge passage 8 of the cooling water pump shown in FIG. 1 and the second water leakage reservoir 21 are viewed from the right side of FIG. The internal combustion engine mounted in the engine room takes a posture in which the axis of the cylinder bore of the cylinder is slightly inclined. In the present embodiment, the second water leakage reservoir 21 is formed in the front cover 2 by utilizing the inclined mounting angle of the internal combustion engine.

As shown by an arrow in FIG. 2, the cooling water overflowing from the second water leakage reservoir 21 leaks by flowing down through the gap between the front cover 2 and the cylinder block 1 of the main body of the internal combustion engine. The leaked cooling water comes into contact with the high-temperature cylinder block 1 or is rapidly vaporized and evaporated by the heat generated from the cylinder block 1. Moreover, the part where the cooling water leaks does not intersect with the line of sight E of the person who opens the hood of the vehicle and visually recognizes the inside of the engine room (the person cannot see the part), and the cooling water leaked by the person is leaked. It is extremely difficult to see directly.

The cooling water pump of the present embodiment includes a pump housing 5 fixed to the main body of the internal combustion engine, a pulley 32 arranged so as to surround a part of the pump housing 5 and rotating in accordance with the crankshaft of the internal combustion engine, and the above. A rotary shaft 3 connected to a pulley 32 and rotatably supported in the pump housing 5 via a bearing 56 and provided with an impeller 31 at an end thereof, and between the impeller 31 and the bearing 56. A seal 52 provided at a portion to prevent the cooling water from flowing from the impeller 31 side to the bearing 56 side, a flow passage 59 for allowing the cooling water leaked through the portion provided with the seal 52 to flow down, and a flow passage 59. A first water leakage reservoir 50 capable of storing a predetermined amount of the cooling water flowing down the engine, and a discharge opening in a direction away from the pulley 32 for discharging the cooling water overflowing from the first water leakage reservoir 50. A passage 8 and a second water leakage reservoir 21 capable of storing a predetermined amount of cooling water discharged through the discharge passage 8 are provided.

According to the present embodiment, since the leakage of the cooling water is conspicuous, the problem that the user or the dealer mistakes the cooling water pump without the defect as the cooling water pump with the defect can be effectively avoided. Therefore, it is not necessary to replace the cooling water pump which is originally unnecessary.

The present invention is not limited to the embodiments described in detail above. The specific configuration of each part and the content of the process can be variously modified without departing from the spirit of the present invention.

1 ... Cylinder block 2 ... Front cover 21 ... Second leak reservoir 3 ... Rotating shaft 31 ... Impeller 32 ... Pulley 5 ... Pump housing 52 ... Seal 56 ... Bearing 59 ... Flow passage 50 ... First leak reservoir 8 ... Discharge passage

Claims (1)

The pump housing fixed to the main body of the internal combustion engine and
A pulley that rotates according to the crankshaft of an internal combustion engine,
A rotating shaft connected to the pulley and rotatably supported in the pump housing via a bearing and provided with an impeller at its end.
A seal provided at a portion between the impeller and the bearing to prevent cooling water from flowing from the impeller side to the bearing side.
A flow passage for allowing the cooling water leaked through the portion provided with the seal to flow down, and a flow passage.
A first water leakage reservoir that can store a predetermined amount of cooling water that has flowed down the flow passage, and
A discharge passage that is open in a direction away from the pulley and discharges the cooling water that overflows from the first leak reservoir.
A structure of a cooling water pump of an internal combustion engine including a second water leakage reservoir capable of storing a predetermined amount of cooling water discharged through the discharge passage.

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