JP7132890B2 - water cooled engine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled engine, and more particularly to a water-cooled engine that can reduce horsepower loss when the engine rotates at low speeds and can provide high output at low speeds and high loads.

Conventionally, a water pump and a cooling water jacket around the combustion chamber are provided, and the engine cooling water is circulated between the water pump and the cooling water jacket, and the water pump is inserted into the pump housing and the pump housing. There is a water-cooled engine with a rotating shaft mounted on a pump housing and an impeller mounted on the rotating shaft within a pump housing (see, for example, Patent Document 1).

Japanese Utility Model Laid-Open No. 62-40219 (see FIGS. 1 to 3)

<Problem 1> There is a possibility that the horsepower loss increases when the engine rotates at low speeds.
In the engine disclosed in Patent Literature 1, the impeller blades are fixed to the base plate in an upright posture parallel to the rotation axis. In this engine, when the engine is running at low speeds, the blades in the upright position are subjected to a large pumping resistance of the engine cooling water, and there is a possibility that the horsepower loss increases.

<Problem 2> There is a possibility that high output cannot be obtained at low rotation speed and high load.
In the engine of Patent Document 1, when the piston moves slowly up and down, heat is released from the combustion chamber over a long period of time at low rpm and high load. , there is a risk that high output cannot be obtained due to unstable combustion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water-cooled engine that can reduce horsepower loss at low engine speeds and obtain high output at low speeds and high loads.

The main configuration of the present invention is as follows.
As illustrated in FIG. 2, it comprises a water pump (1) and a cooling water jacket (3) around the combustion chamber (2), and between the water pump (1) and the cooling water jacket (3) the engine cooling water is pumped. (4) is configured to circulate,
The water pump (1) comprises a pump housing (5), a rotating shaft (6) inserted into the pump housing (5), and an impeller (7) attached to the rotating shaft (6) within the pump housing (5). ),
As illustrated in FIG. 1(B), when the engine is running at low speed, an unbalanced force (16) based on the biasing force (11a) of the biasing means (11) and the centrifugal force (9a) acting on the blades (9) The blade (9) is in a lodging posture (12),
When the engine rotates at high speed, the unbalanced force (16) causes the blades (9) in the lying posture (12) to approach the standing posture (13) along the direction parallel to the rotation axis (6) ,
As illustrated in FIG. 2, the pump housing (5) comprises a front housing (5a) and a rear housing (5b) covering the front housing (5a) from the rear side. (5c), the bearing (27) is accommodated in the bearing boss (5c), the rotating shaft (6) is supported by the bearing (27),
As exemplified in FIGS. 4(A) and 4(B), a radiating fin (5g) protruding along a corner (5h) of the surface of the front housing (5a) and the peripheral surface of the bearing boss (5c) is provided, A water-cooled engine, wherein a plurality of radiating fins (5g) are radially formed along the surface of the front housing (5a) from the peripheral surface of the bearing boss (5c) .

The present invention has the following effects.
<Effect 1> It is possible to reduce horsepower loss when the engine rotates at low speeds.
In this engine, when the engine speed is low, the blades (9) shown in FIG. It can reduce horsepower loss.

<Effect 2> A high output can be obtained at low rotation speed and high load.
In this engine, at low rotation and high load, the blades (9) illustrated in FIG. Since the pumping amount of the piston (14) is slow, the amount of heat released from the combustion chamber (2) is reduced even at low rotation and high load, which lengthens the heat release time from the combustion chamber (2). High output can be obtained by combustion.

<Effect 3> Appropriate cooling performance can be obtained when the engine rotates at high speed.
In this engine, when the engine rotates at high speed when the amount of heat generated increases, the blades (9) in the lying posture (12) illustrated in FIG. 1(B) approach the standing posture (13), and the coolant jacket ( The amount of pumped engine cooling water (4) to 3) is increased, and proper engine cooling performance is obtained.

1(A) is a front view and FIG. 1(B) is a cross-sectional view taken along the line BB of FIG. 1(A). FIG. 1 is a side elevational cross-sectional view of a main part of a water-cooled engine according to an embodiment of the present invention; FIG. 3 is a side elevational cross-sectional view of the water-cooled engine of FIG. 2; FIG. 2, FIG. 4(A) is a front view of the front housing, FIG. 4(B) is a cross-sectional view taken along line BB of FIG. 4(A), and FIG. (C) is an illustration of a low-friction coating on the surface of the impeller.

1 to 4 are diagrams for explaining a water-cooled engine according to an embodiment of the present invention. In this embodiment, a water-cooled vertical in-line multi-cylinder diesel engine will be explained.

As shown in FIG. 3, this engine includes a cylinder block (17), a cylinder head (18) assembled to the upper part of the cylinder block (17), and a cylinder head cover (18) assembled to the upper part of the cylinder head (18). 19), the crankshaft 10 installed in the crankcase 20 of the cylinder block 17, and the installation direction of the crankshaft 10 being the front-rear direction. ), an engine cooling fan (21) assembled in front of the water pump (1), and a radiator (22) located in front of the engine cooling fan (21). ), a flywheel (23) arranged in the rear part of the cylinder block (17), and an oil pan (24) assembled in the lower part of the cylinder block (17).

This engine is equipped with a water cooling system.
As shown in FIG. 3, the water cooling system includes a water pump (1), a cooling water jacket (3) to which engine cooling water (4) of the water pump (1) is pumped, and an engine cooling water jacket (3). It has a thermostat housing pipe (25) for leading out cooling water (4), a thermostat (26) housed in the thermostat housing pipe (25), and a radiator (22). When the water temperature of the engine cooling water (4) in the cooling water jacket (3) is low, the thermostat (26) returns the engine cooling water (4) in the cooling water jacket (3) to the water pump (1), is high, the engine cooling water (4) in the cooling water jacket (3) is led out to the radiator (22).

As shown in FIG. 2, the cooling water jacket (3) comprises a cylinder jacket (3a) provided inside the cylinder block (17) and a head jacket (3b) provided inside the cylinder head (18), The engine cooling water (4) pumped from the water pump (1) flows from the cylinder jacket (3a) through the head jacket (3b) into the thermostat housing pipe (25).

As shown in FIG. 2, this engine is equipped with a water pump (1) and a cooling water jacket (3) around the combustion chamber (2), and between the water pump (1) and the cooling water jacket (3) The engine cooling water (4) is configured to circulate.
The water pump (1) comprises a pump housing (5), a rotating shaft (6) inserted into the pump housing (5), and an impeller (7) attached to the rotating shaft (6) within the pump housing (5). ).
The impeller (7) has a base plate (8) mounted in a posture perpendicular to the rotating shaft (6) and blades (9) provided on the base plate (8). It is driven by the shaft (10), and as shown in FIG. 2, the engine cooling water (4) is pumped by the vanes (9) in the centrifugal direction of the impeller (7).

As shown in FIG. 1(B), the blades (9) are attached to the base plate (8) so as to be able to rise and fall, and are biased to the lying posture by the biasing force (11a) of the biasing means (11).
As shown in FIG. 1(B), when the engine rotates at a low speed, the unbalanced force (16) based on the biasing force (11a) of the biasing means (11) and the centrifugal force (9a) acting on the blades (9) causes the blades to (9) is brought to the lying posture (12). This unbalanced force (16) generates an unbalanced moment based on the urging force (11a) of the urging means (11) and the centrifugal force (9a) acting on the blades (9), causing the blades (9) to fall down ( 12).
When the engine rotates at high speed, the unbalanced force (16) causes the blades (9) in the lying posture (12) to approach the standing posture (13) along the direction parallel to the rotating shaft (6).

In this engine, when the engine speed is low, the blades (9) shown in FIG. loss can be reduced.

In addition, in this engine, the blades (9) shown in FIG. 1(B) are in a lodging posture (12) at low rotation and high load, and the engine cooling water (4) to the cooling water jacket (3) shown in FIG. Since the pumping amount of the piston (14) is slow, the amount of heat released from the combustion chamber (2) is reduced even at low rotation and high load, which lengthens the heat release time from the combustion chamber (2). High output can be obtained by combustion.

In addition, in this engine, when the engine rotates at high speed when the amount of heat generated increases, the blades (9) in the lying posture (12) shown in FIG. The amount of pumped engine cooling water (4) to 3) is increased, and proper engine cooling performance is obtained.

As shown in FIG. 1(B), the vane (9) has a locked portion (15), and the locked portion (15) is locked to the base plate (8) when the engine speed exceeds a predetermined number of revolutions. , and the blades (9) are configured to maintain the standing posture (13).

In this engine, when the engine speed exceeds a predetermined speed, the engaged portion 15 is engaged with the base plate 8 shown in FIG. Pulsation of the water (4) is less likely to occur, and the pump efficiency of the water pump (1) shown in FIG. 2 can be increased at high engine speeds.

As shown in FIG. 2, the pump housing (5) comprises a front housing (5a) and a rear housing (5b) covering the front housing (5a) from the rear side. 5c), a cooling water introduction pipe (5d) for introducing engine cooling water (4) from the radiator (22), and the engine cooling water (4) in the thermostat housing pipe (25) bypassing the radiator (22). A cooling water bypass pipe (5e) bypassing the pump (1) is provided, and the rear housing (5b) is provided with a cooling water outlet passage (5f) for leading the engine cooling water (4) to the cooling water jacket (3). there is

A bearing (27) is housed in the bearing boss (5c) of the front housing (5a), and the rotating shaft (6) supported by the bearing (27) is inserted into the pump housing (5), and the rotating shaft (6) is rotated. An input pulley (28) and an engine cooling fan (21) are attached to the front end, and an impeller (7) is attached to the rear end of the rotating shaft (6) in the rear housing (5b). It is watertightly sealed by a mechanical seal (29) in the front housing (5a).

As shown in FIG. 1(A), the impeller (7) comprises a base plate (8), six blades (9), and biasing means (11).
The base plate (8) includes a plate boss (8b) protruding perpendicularly from the center of a flat plate body (8a) shown in FIGS. 1(A) and (B), and a plate body (8a) shown in FIG. A standing piece (8c) erected in a perpendicular direction from the periphery of the shaft (8c), a pivot support boss (8d) fixed to the standing piece (8c), and a pivot (8e) internally supported by the pivot support boss (8d) ing.

The vane (9) has a loose fitting boss (9b) attached to the base end and a locked portion (15) attached to the loose fitting boss (9b). ), and is attached to the base plate (8) so that it can rise and fall with its tip as a swinging free end. By being locked, the upright posture (13) of the blades (9) is maintained.
The biasing means (11) is a tension spring, which is installed between the plate body (8a) and the blades (9).

As shown in FIG. 1(A), the impeller (7) rotates clockwise as indicated by an arrow (7a) when viewed from the front, and the engine coolant (4) shown in FIG. Pump in the centrifugal direction. As shown in FIG. 3, the impeller (7) is driven from the crankshaft (10) via a fan belt (30).

A water-repellent film is formed on the surfaces of the base plate (8) and blades (9) that constitute the impeller (7) shown in FIGS. 1(A) and (B).
Therefore, the water-repellent film reduces the flow resistance of the engine cooling water (4) against the impeller (7), thereby increasing the pump efficiency.
In addition, the impeller (7) with reduced water flow resistance reduces vibrations and reduces pump noise.
A fluorine resin film can be used as the water-repellent film.

The surface of the impeller (7) may be a low-friction surface.
In this case as well, the low-friction surface reduces the frictional resistance of the engine cooling water (4) against the impeller (7), as in the case of the water-repellent film, thereby increasing the pump efficiency.
In addition, the impeller (7), in which the frictional resistance of the engine cooling water (4) is reduced, reduces vibration and pump noise.

Specific examples of the low-friction surface include a glass coat, a metal mirror-finished surface, and a low-friction coating (33) shown in FIG. 4(C).
The low friction coating (33) will be described later.

As shown in FIGS. 4(A) and 4(B), the front housing (5a) constituting the pump housing (5) of the water pump (1) is composed of the surface of the front housing (5a) and the peripheral surface of the bearing boss (5c). It has a radiating fin (5g) protruding along the corner (5h).
Therefore, the cooling efficiency of the engine cooling water (4) and the bearing (27) shown in FIG.

A plurality of radiation fins (5g) shown in FIG. 4(B) are radially formed along the surface of the front housing (5a) from the peripheral surface of the bearing boss (5c) as shown in FIG. 4(A). .
Therefore, the rigidity of the front housing (5a) shown in FIG. 4(A) is increased by the plurality of radiation fins (5g), vibration is reduced, and pump noise is reduced.
Also, the engine cooling water (4) leaking from the bearing boss (5c) shown in FIGS. Intensive contamination around the water pump (1) by leaking engine cooling water (4) can be avoided.

The low-friction film (33) shown in FIG. 4(C) is formed of a film of a material selected from resin containing solid lubricant, fluororesin, diamond-like carbon, molybdenum disulfide, graphite, manganese phosphate, and chromium. It is Therefore, the low-friction coating (33) can be easily formed by surface treatment.

Examples of solid lubricants include inorganic solid lubricants such as transition metal oxides and graphite.
Resins include polyamide resins, epoxy resins, phenol resins, silicone resins, polyimide resins, and the like.

As shown in FIG. 4(C), a plurality of low-friction coatings (33) (33) are arranged in a spotted manner, and the grooves (34) between the coatings are formed in a mesh pattern.
Each of the plurality of low-friction coatings (33) (33) is formed in a regular hexagonal shape.
The plurality of low-friction coatings (33) (33) are not limited to regular hexagons, and may have various polygonal shapes and circular shapes.
When the impeller (7) rotates in the direction of the arrow (7a) on the left side of FIG. 4(C), the engine cooling water (4) flows in the inter-film groove (34) as shown by the arrow (4a).

(1) Water pump (2) Combustion chamber (3) Cooling water jacket (4) Engine cooling water (5) Pump housing (6) Rotating shaft (7) Impeller (8) Base plate (9) Blade (9a) Centrifugal force (10) Crankshaft (11) Biasing means (11a) Biasing force (12) Laying posture (13) ) ... standing posture, (15) ... engaged portion, (16) ... unbalanced force.

Claims (5)

Equipped with a water pump (1) and a cooling water jacket (3) around the combustion chamber (2) such that engine cooling water (4) circulates between the water pump (1) and the cooling water jacket (3) configured,
The water pump (1) comprises a pump housing (5), a rotating shaft (6) inserted into the pump housing (5), and an impeller (7) attached to the rotating shaft (6) within the pump housing (5). ),
The impeller (7) has a base plate (8) mounted in a posture orthogonal to the rotating shaft (6) and blades (9) provided on the base plate (8). and the engine cooling water (4) is pumped in the centrifugal direction of the impeller (7) by the vanes (9),
The blades (9) are attached to the base plate (8) so as to be able to rise and fall, and are biased to the lying posture by the biasing force (11a) of the biasing means (11),
When the engine is running at low speed, the unbalanced force (16) based on the biasing force (11a) of the biasing means (11) and the centrifugal force (9a) acting on the blades (9) causes the blades (9) to fall down (12). become,
When the engine rotates at high speed, the unbalanced force (16) causes the blades (9) in the lying posture (12) to approach the standing posture (13) along the direction parallel to the rotation axis (6) ,
The pump housing (5) includes a front housing (5a) and a rear housing (5b) covering the front housing (5a) from the rear side. The front housing (5a) includes a bearing boss (5c). The bearing (27) is accommodated in (5c), and the rotating shaft (6) is supported in the bearing (27),
A radiating fin (5g) protrudes along a corner (5h) between the surface of the front housing (5a) and the peripheral surface of the bearing boss (5c). A water-cooled engine characterized by a plurality of radially formed along the surface of a front housing (5a) from a plane . A water-cooled engine according to claim 1,
A water-cooled engine characterized in that a water-repellent film is formed on the surface of the impeller (7). A water-cooled engine according to claim 1,
A water-cooled engine characterized in that the surface of an impeller (7) is a low-friction surface, and the low-friction surface is formed of a glass coat or a mirror-finished surface of metal. A water-cooled engine according to claim 1,
A low-friction film (33) is formed on the surface of the impeller (7), and the low-friction film (33) is made of resin containing a solid lubricant, fluororesin, diamond-like carbon, molybdenum disulfide, graphite, manganese phosphate, A water-cooled engine, characterized in that it is formed of any one of a film made of a material selected from chromium. In the engine according to any one of claims 1 to 4 ,
The blade (9) has a locked portion (15), and when the engine speed exceeds a predetermined number of revolutions, the locked portion (15) is locked to the base plate (8), and the blade (9) is in an upright posture ( 13 ).

Images