JP7349265B2 - Internal combustion engine with integrated water pump for automobiles - Google Patents

Description

The present invention relates to an internal combustion engine for an automobile in which a water pump is integrated into an engine body.

Internal combustion engines for automobiles are generally water-cooled and are therefore equipped with a water pump driven by a crankshaft. The water pump is driven by a crank pulley, but as disclosed in Patent Document 1, the entire water pump has a structure independent from the engine body, and as disclosed in Patent Document 2, the water pump has a structure independent from the engine body. There is also an integrated type in which the pump chamber is formed in the engine body.

In any case, the water pump includes a rotating shaft to which an impeller is fixed at one end, and the rotating shaft is rotatably held in the cover housing by a bearing. The cover housing is equipped with a sealing material (mechanical seal) that prevents cooling water from flowing to the bearing side, but the sealing material's water-sealing function is not perfect, and a small amount of water leaks (drainage). water) is likely to occur.

Therefore, in order to prevent the cooling water that has passed through the gap between the rotating shaft and the sealing material from reaching the bearing, a drain passage is formed in the cover housing to discharge leaked drain water, but the drain water remains as it is. If water drops fall onto the ground, for example when the vehicle is being warmed up while the vehicle is parked in a garage, it may be mistaken for a defect or malfunction, so a drainage basin is provided in the drain passage.

As an example, in Patent Document 1, a drain water reservoir is formed on the mating surface of a cover housing in which a rotating shaft is rotatably held and a pump housing in which a pump chamber is formed, and a discharge port is provided at the upper end of the drain water reservoir. It is disclosed that a control wall is formed at a mid-height position of the drain water reservoir to prevent the drain water from flowing directly to the discharge port.

On the other hand, in Patent Document 2, a drain water reservoir is formed in a cover housing in which a rotating shaft is rotatably held, and a drain water outlet is formed in a mating surface of the cover housing and the front cover. As in Patent Document 2, when the front cover is also used as a part of the housing of the water pump, there is an advantage that the number of parts can be reduced and the weight of the internal combustion engine can be reduced.

Japanese Patent Application Publication No. 2011-247179 Japanese Patent Application Publication No. 2016-070094

Now, as mentioned above, the purpose of forming the drain water reservoir in the drain passage is to store the drain water to prevent it from flowing down as much as possible, so it is desirable that the capacity of the drain water reservoir is as large as possible. In this respect, in an external water pump such as that disclosed in Patent Document 1, since the housing cannot be made large, there is a limit to how much the capacity of the drain water reservoir can be increased.

On the other hand, in a system in which a water pump is incorporated into the engine body as in Patent Document 2, it can be said that a large capacity drain water reservoir can be formed by using a front cover and a cylinder block.

The present invention was made against the background of this current situation, and in a configuration in which the water pump component is also used in the engine body as in Patent Document 2, the invention effectively utilizes the engine body to drain the drain water pool. The aim is to increase the capacity of

The present invention is
"It is equipped with a cylinder block, a front cover that is fixed to the front of the cylinder block and covers the timing chain, and a water pump that is driven by a crank pulley.
The water pump has a rotating shaft that passes through the front cover, and a cover housing that is fixed to the outer surface of the front cover and rotatably holds the rotating shaft. forming a pump chamber of the water pump.
This is the basic configuration.

In the above basic configuration,
A drain passage through which cooling water leaked from the pump chamber through the seal portion of the rotating shaft is communicated with a downward drain passage provided in the cover housing and a lower end of the downward drain passage, and Consisting of a horizontal drain passage penetrating the cover and the cylinder block,
A drain water reservoir portion having a large cross-sectional area of the horizontal drain passage is formed on a mating surface between the front cover and the cylinder block and a mating surface between the cover housing and the front cover ,
A partition wall is formed on the front cover to partition the two drain water reservoirs, and a communication hole is formed in the upper part of the partition wall, and
A discharge hole constituting an end of the horizontal drain passage is formed in the cylinder block at approximately the same height as the communication hole.
This configuration is added.

Therefore, in the present invention, the drain water reservoir is formed not only on the mating surface of the cylinder block and the front cover, but also on the mating surface of the cover housing and the front cover.

In the present invention, since the cylinder block and front cover have a large volume, if the cylinder block and front cover are used to form the drain water pool as in the present invention, the capacity of the drain water pool can be made much larger than in the past. can.

Therefore, it is possible to suppress drain water from flowing down to the ground, and to prevent or significantly suppress a situation where the drain water is mistakenly recognized as a defect or malfunction. Water pumps are also equipped with an upward drain passage, which evaporates and dissipates drain water. Since the function of evaporating drain water is also improved, it is possible to prevent the drain water reservoir from becoming full. In this respect as well, dripping of drain water can be suppressed.

What's more, the cylinder block and front cover are lighter by making the drain water reservoir larger, which can also contribute to improved fuel efficiency.

According to the present invention , the drain water pool is formed by a second drain water pool formed on the mating surface between the cylinder block and the front cover, and a first drain water pool formed on the mating surface between the front cover and the cover housing. By forming a communication hole in the partition wall that partitions the two, it is possible to prevent drain water from moving from the first drain water pool to the second drain water pool due to vibrations of the internal combustion engine or vibrations of the vehicle body. This can greatly reduce the problem of drain water falling to the ground due to shaking or vibration even though it is not full. Therefore, the effect of increasing the capacity of the drain water reservoir can be accurately enjoyed.

FIG. 2 is a longitudinal sectional side view of the main parts of the embodiment as viewed from the direction of the intake side of the internal combustion engine. It is a perspective view of the main part, and only the flange of the cover housing is shown. FIG. 2 is a view of the cover housing viewed from the III-III viewing direction in FIG. 1; FIG. 3 is a cutaway perspective view of main parts.

Next, embodiments of the present invention will be described based on the drawings. In the following, words such as "front and rear" and "left and right" are used to specify the direction, but the front and rear direction is the direction of the crank axis, and the left and right direction is the direction perpendicular to the crank axis and the cylinder bore axis. Regarding the front and rear, the side where the timing chain is located is the front, and the side where the transmission is located is the rear.

In this embodiment, the internal combustion engine is disposed in the engine room in a horizontal front exhaust position with the crankshaft oriented in the vehicle width direction and the exhaust side of the engine body oriented in the forward direction of the vehicle body. Therefore, the front, rear, left, and right sides of the internal combustion engine are different from the front, rear, left, and right sides of the vehicle body by 90 degrees. Also, based on the direction of the car body, the intake side of the engine body faces toward the rear.

(1).Basic structure Figure 1 is a longitudinal side view of the arrangement part of the water pump 1 viewed from the exhaust side. As shown in this figure, the engine body is fixed to the cylinder block 2 and its front surface. A cover housing 4, which is a component of the water pump 1, is fixed to the front surface of the front cover 3.

As shown in FIG. 2, the cylinder block 2 and the front cover 3 are formed with sideways projecting parts 5 and 6 that project toward the intake side beyond the arrangement space of the timing chain. A cover housing 4 is fixed to. A boss portion 8 having a built-in cooling water return passage 7 is integrally connected to the horizontally extending portion 5 of the cylinder block 2. In FIG. 2, reference numeral 9 indicates a separator chamber for removing oil mist from the blow-by gas, and the separator chamber 9 is closed with a lid.

As shown in FIG. 1, a rotary shaft 10 is rotatably held in the cover housing 4 via a ball bearing 11, and a pulley 12 is attached to one end of the rotary shaft 10 that protrudes outward from the cover housing 4. Fixed. An accessory drive belt (not shown) is wound around the pulley 12 of the water pump 1 and a crank pulley (not shown). The pulley 12 is formed into a bowl shape so as to partially surround the cover housing 4, and is fixed to the rotating shaft 10 via a reinforcing disk 13. The ball bearing 11 has an outer race 14 press-fitted into the cover housing 4.

The cover housing 4 has a thick portion that holds the rotating shaft 10 and a flange 4b having a plurality of bolt insertion holes 4a (see FIG. 2), and the flange 4b is elongated downward.

The rotating shaft 10 has the other end that passes through the front cover 3 and faces the cooling water return passage 7, and an impeller 15 is fixed to this other end. A pump chamber 16 is formed in the front cover 3. Therefore, a part of the front cover 3 constitutes a part of the pump housing of the water pump 1. Water pump 1 is arranged at the top of cylinder block 2.

In this embodiment, the cooling water flows into the pump chamber 16 from the axial direction of the rotating shaft 10 and is discharged in the outer circumferential direction (tangential direction) of the rotation locus of the impeller 15 . Therefore, a cooling water sending passage 17 is formed in the upper part of the cooling water return passage 7 in the cylinder block 2 . Although not shown, the cooling water feed passage 17 is branched into a portion facing the water jacket formed in the cylinder block 2 and a portion facing the cylinder head. The state is such that most of it flows into the water jacket of the cylinder head, and a state where most of it flows into the water jacket of the cylinder block.

In order to prevent the cooling water in the pump chamber 16 from flowing toward the ball bearing 11, first and second sealing materials 18 and 19 are fitted onto the rotating shaft 10 with a certain distance between them. There is. The first sealing material 18 is non-rotatably fitted to the cover housing 4, and the second sealing material 19 is non-rotatably fitted to the outer race 14. Therefore, the rotating shaft 10 is rotatably fitted in both sealing materials 18 and 19, and the pump chamber 16 is water-sealed by a mechanical seal structure including the two sealing materials 18 and 19.

(2) Drain passage There is an upward drain passage 20 and a downward drain passage in order to discharge the cooling water (drain water) that has leaked from the first sealing material 18 to a portion of the cover housing 4 between both sealing materials 18 and 19. A drain passage 21 is formed. The upward drain passage 20 evaporates and discharges the cooling water, and the outlet 20a opens toward the inside of the pulley 12. Therefore, the water vapor is sucked in by the rotation of the pulley 12 and dissipated to the outside. Reference numeral 22 indicates a plug that closes the hole formed by drilling.

The lower end of the downward drain passage 21 communicates with a horizontal drain passage 23 that penetrates the front cover 3 and the horizontal extensions 5 and 6 of the cylinder block 2 . The horizontal drain passage 23 includes a first drain water reservoir 24 formed on the mating surface between the cover housing 4 and the front cover 3, and a second drain water reservoir 25 formed on the mating surface between the front cover 3 and the cylinder block 2. , a partition wall 26 formed in the front cover 3 to partition both drain water reservoirs 24 and 25 , a communication hole 27 formed in the upper part of the partition wall 26 , and a discharge hole formed in the horizontally extending portion 5 of the cylinder block 2 It has 28.

The upper surfaces of the two drain water pools 24 and 25 are approximately at the same height, but when looking at the bottom surface, the bottom surface of the second drain water pool 25 is slightly lower than the bottom surface of the first drain water pool 24. (They may be the same height.) The communication hole 27 and the discharge hole 28 are at approximately the same height and are located near the upper ends of both drain water reservoirs 24 and 25. The capacity of the second drain water reservoir section 25 is larger than that of the first drain water reservoir section 24.

In this configuration, a part of the cooling water leaking through the first sealing material 18 evaporates and is dissipated from the upward drain passage 20, and the rest flows down to the downward drain passage 21 and once accumulates in the first drain water reservoir 24, When the first drain water pool 24 is full, it flows into the second drain water pool 25 from the communication hole 27, and when the second drain water pool 25 is full, it flows down to the outside from the discharge hole 28.

In this case, both the drain water reservoirs 24 and 25 are formed in the horizontally extending parts 5 and 6 of the front cover 3 and the cylinder block 2, but since the horizontally extending parts 5 and 6 have a certain width in the front and rear, Since both the drain water reservoirs 24 and 25 can secure a certain amount of front and rear width, and the lower surfaces of both the drain water reservoirs 24 and 25 can be lowered without any problem, the capacities of both the drain water reservoirs 24 and 25 can be set arbitrarily. can. Therefore, sufficient amount of drain water can be stored so that it does not easily drip onto the ground. Furthermore, by increasing the capacity of the drain water reservoirs 24 and 25, the weight of the front cover 3 and cylinder block 2 can be reduced, contributing to improved fuel efficiency.

In addition, by storing a large amount of drain water in both drain water reservoirs 24 and 25, the function of evaporating the drain water and discharging it from the upper drain passage 20 can be improved, so that the second drain water reservoir 25 becomes full. can be suppressed. In this respect as well, dripping of drain water can be significantly suppressed.

Unlike the embodiment, it is also possible to partially penetrate the front cover 3 to form one drain water reservoir. That is, it is also possible to form the front cover 3 without the partition wall 26. However, in this case, there is a possibility that the drain water may easily move to the discharge hole 28 due to vibration of the vehicle body or the like.

In this regard, if the two drain water reservoirs 24, 25 are separated by the partition wall 26 as in the embodiment, the movement of the cooling water is suppressed, and the cooling water drips down before both the drain water reservoirs 24, 25 are full. This has the advantage of preventing this phenomenon. Note that the drain water reservoirs 24 and 25 can be easily formed when manufacturing each member by die-casting or casting.

In the internal combustion engine of this embodiment, the cylinder bore axis is slanted forward at a slight angle (for example, several degrees to 10 degrees) with respect to the vertical line. On the other hand, since the sideways projecting portion 5 of the cylinder block 2 is located at the upper part of the cylinder block 2, the drain water flowing down from the discharge hole 28 of the sideways drain passage 23 is prevented from flowing down to the intake side of the cylinder block 2. can.

Since the temperature of the cylinder block 2 increases during operation, the drain water can be evaporated while flowing along the intake side of the cylinder block 2. For example, in FIG. 2, reference numeral 29 indicates a boss portion for attaching the alternator, and drain water flows from the discharge port 28 of the horizontal drain passage 23 to the boss portion 29, and further flows into the crankcase etc. In order to obtain this, evaporation due to contact with the cylinder block 2 can be promoted. In this embodiment, dripping of drain water onto the ground can be prevented or significantly suppressed in this respect as well.

Although the embodiments of the present invention have been described above, the present invention can be embodied in various other ways. For example, when providing two drain water pools, the first drain water pool 24 and the second drain water pool 25, it is possible to form the first drain water pool 24 deeper than the second drain water pool 25. The rotating shaft may be rotatably held by a resin ring or the like.

The present invention can be embodied in an internal combustion engine for an automobile. Therefore, it can be used industrially.

1 Water pump 2 Cylinder block 3 Front cover 4 Cover housing 5, 6 Lateral overhang 7 Cooling water return passage 10 Rotating shaft 11 Ball bearing 12 Pulley 15 Impeller 16 Pump chamber 17 Cooling water feed passage 18, 19 Seal material 20 Upward drain passage 21 Downward drain passage 23 Sideways drain passage 24, 25 Drain water reservoir 26 Partition wall 27 Communication hole 28 Discharge hole

Claims (1)

It is equipped with a cylinder block, a front cover that is fixed to the front of the cylinder block and covers the timing chain, and a water pump that is driven by a crank pulley.
The water pump has a rotating shaft that passes through the front cover, and a cover housing that is fixed to the outer surface of the front cover and rotatably holds the rotating shaft. A configuration forming a pump chamber of the water pump,
A drain passage through which cooling water leaked from the pump chamber through the seal portion of the rotating shaft is communicated with a downward drain passage provided in the cover housing and a lower end of the downward drain passage, and is connected to the front cover. and a horizontal drain passage penetrating the cylinder block ,
A drain water reservoir portion having a large cross-sectional area of the horizontal drain passage is formed on a mating surface between the front cover and the cylinder block and a mating surface between the cover housing and the front cover ,
A partition wall is formed on the front cover to partition the two drain water reservoirs, and a communication hole is formed in the upper part of the partition wall, and
A discharge hole constituting an end of the horizontal drain passage is formed in the cylinder block at approximately the same height as the communication hole.
Internal combustion engine with integrated water pump for automobiles.

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