JPH06101472A - Timing belt cooling structure of engine - Google Patents

Abstract

PURPOSE:To provide the timing belt cooling structure of an engine which is caused to introduce running air in a timing belt cover with high efficiency, separate dust in running air away from air by utilizing an existing device, and lead out the running air, by means of which a timing belt is cooled, with high efficiency. CONSTITUTION:An air introduction port 9 is formed in the lower part of a timing belt fronting on a motor-operated fan and dust and air are separated away from each other by means of a rib 14 for reinforcing an oil pump arranged downstream therefrom. Running air separated away from dust flows through a space part 17, surrounded with the outer surface of a timing belt 7, one end surface of an engine l, and a timing belt cover, to cool the timing belt 7. An air lead-out port through which air is lead out to the outside of the timing belt cover is formed in a position being a shortmost distance between a bonnet 10 and the timing belt cover, and a wide space part is formed in rear of the air lead-out port.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cooling of a timing belt for transmitting a driving force of an engine to a cam pulley.

[0002]

2. Description of the Related Art Generally, a timing belt, a chain or the like is used for transmitting a driving force of an engine to a cam pulley. Of these, the timing belt is generally often used because the noise when driving is quiet. Further, since the timing belt is made of resin and the durability of the belt itself deteriorates due to the adhesion of water, dust, etc., the timing belt cover is provided to seal the belt. However, with the above-mentioned configuration, hot air is likely to be trapped inside the cover, and durability of the belt due to heat becomes a problem. To solve this problem, as shown in Japanese Utility Model Laid-Open No. 63-98429, the timing belt cover portion facing the front surface of the cam pulley is cooled in a space formed between the timing belt cover and one end surface of the engine. A hole for introducing wind (running wind) is provided, and a fan is provided in front of the cam pulley. Cooling wind is introduced by the fan into the space through the hole to cool the belt, and then the crankshaft is cooled. It is known that the cooling air is discharged from an air discharge port near a crank pulley attached to one end.

[0003]

However, when the technique of the above publication is applied to a vertical engine in which the front surface of the cover faces the direction in which the cooling air flows, the direction in which the cooling air flows and the cooling air flow are The cooling air can be easily introduced into the space because it is introduced in the same direction as the space, but the cooling air is discharged in the direction in which the cooling air flows and the direction in which the cooling air is discharged from the space. Since and are the opposite directions, the cooling air is not efficiently discharged.

When this technique is applied to a horizontal engine, the cooling air flowing from the space near the air outlet efficiently discharges the cooling air from the space. Since the flowing direction and the direction of introducing the cooling air into the space are substantially orthogonal to each other, the air is not efficiently introduced into the space. In order to solve this, it is necessary to provide a guide plate so as to guide the cooling air to the air introduction port, and it is impossible to achieve a compact layout in the engine room and a reduction in the number of parts, which has been said in recent years.

Therefore, in order to solve such a problem, an object of the present invention is to provide a horizontal engine in which the cooling air efficiently introduced into the timing belt cover cools the timing belt and then the cover of the cover. An object is to provide a timing belt cooling structure for an engine that is efficiently led out to the outside.

[0006]

To achieve the above object, the constitution of the present invention is as follows.

According to the first aspect of the present invention, the crankshaft of the engine is arranged in the vehicle width direction, the one end surface of the engine main body is provided with the crank pulley provided at the end of the crankshaft, and the camshaft end of the engine. A power transmission device including a cam pulley provided in the section and a timing belt that transmits a driving force from the crank pulley to the cam pulley is provided, and in front of the engine, a radiator that cools the engine cooling water is arranged. A timing belt cover is provided downstream of the cooling air that has passed through an electric fan that introduces the cooling air to the radiator and that covers the power transmission device. The timing belt cover is attached to one end surface of the engine body to provide an engine. Form a space with the main body,
In a timing belt cooling structure of an engine, in which an air inlet for introducing cooling air into a space inside the timing belt cover is provided in a lower portion of the timing belt cover,

On the upper surface of the timing belt cover, which is the shortest distance between the hood located above the engine and the timing belt cover, there is provided an air outlet for discharging the cooling air in the space to the outside of the timing belt cover, and the air inlet. At a position below the crank pulley,
Provided in a direction substantially orthogonal to the flow of the cooling air introduced into the timing belt cover, provided with a dust separating means for separating air and dust, and surrounded by an engine and a bonnet on the vehicle rear side from the air outlet. In addition, the space portion formed wider than the shortest distance is located.

According to the second aspect, the dust separating means is a plurality of reinforcing ribs formed integrally with the one end surface of the engine body, and the reinforcing ribs are provided from the one end surface side of the engine body in timing. It is projected toward the belt cover side.

According to the third aspect of the present invention, the drive shaft for transmitting the engine driving force to the tire is located behind the engine, and the air introduction port is provided on the front surface of the timing belt cover facing the electric fan. The air outlet is provided on the upper surface of the timing belt cover.

According to the fourth aspect of the present invention, the engine is a V-type engine having a front bank arranged closer to the bonnet and a rear bank arranged farther from the bonnet than the front bank. The air outlet is provided on the upper surface of the timing belt cover of the front bank, and the timing belt rotates in the direction from the rear bank to the front bank via the space between the banks.

[0012]

According to the structure of claim 1,
Cooling introduced from the air inlet provided on the lower front surface of the timing belt cover facing the electric fan to the space formed between the timing belt cover and the engine by attaching the timing belt cover to one end surface of the engine body. An air outlet for discharging the cooling air in the space to the outside of the timing belt cover is provided on the upper surface of the timing belt cover, which is the shortest distance between the bonnet and the timing belt cover, downstream of the wind, and the vehicle is rearward of the air outlet. Has
Since the space surrounded by the engine and the bonnet and wider than the shortest distance is located, that is, the air outlet is provided at the shortest distance between the bonnet and the timing belt cover, and the rear is wide. Since the space is formed, negative pressure is generated in the vicinity of the air outlet, and the ventilating effect allows the cooling air to be efficiently derived from the space in the timing belt cover, thus cooling the timing belt. be able to.

Further, since the air inlet is provided on the timing belt cover surface facing the electric fan, the traveling wind can be introduced into the timing belt cover without using a guide plate or the like.

Further, since dust separating means is provided downstream of the air inlet and below the crank pulley, dust and water in the traveling wind introduced into the cover are separated here, and the belt is separated. It is possible to improve the durability of the belt without sticking to.

According to the second aspect of the invention, the dust separating means is a plurality of reinforcing ribs formed integrally with one end surface of the engine body, and the reinforcing ribs are provided from the one end surface side of the engine body. Since it is projected toward the timing belt cover side, without separately providing another separating means,
Dust can be separated using existing ones.

According to the third aspect of the present invention, the drive shaft for transmitting the engine driving force to the tire is located at the rear of the engine, and the air introduction port is on the front surface of the timing belt cover facing the electric fan. Since the air outlet is provided on the upper surface of the timing belt cover, that is, since there is no air inlet or air outlet at the position facing the drive shaft, mud or dust that the drive shaft bounces up , There is no danger of entering from the air inlet and air outlet.

According to the fourth aspect of the present invention, the engine is a V-type engine having a front bank arranged closer to the bonnet and a rear bank arranged farther from the bonnet than the front bank. , The air outlet is provided on the upper surface of the timing belt cover of the front bank, and since the timing belt rotates in the direction from the rear bank to the front bank through the space between the banks, the timing belt is cooled. The distance of the air passage can be made longer, and the cooling performance of the timing belt can be improved.

Further, even if the mud or dust caused by the jumping up of the drive shaft gets over the rear bank, it does not enter the air outlet provided on the upper surface of the timing belt cover on the front bank side and falls between the banks. The mud and dust are less likely to enter the air outlet.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall configuration diagram of a laterally mounted engine mounted on a vehicle, FIG. 2 is a diagram in which a timing belt cover and an accessory drive belt of the engine of FIG. 1 are removed, and FIG. 3 is a main part of dust separating means. Sectional view, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, FIG. 5 is a plan view of FIG. 1, FIG. 6 is a view of arrow C of FIG. 1, and FIG. 7 is a filter fitted to an air outlet. It is a perspective view of a part.

V-type engine 1 (hereinafter referred to as engine 1)
In a vehicle A having a front grill, the crankshaft 18 is arranged so as to face the vehicle width direction. Then, the drive shaft 2 is driven via a transmission (not shown). The drive shaft 2 is located behind the engine 1.

An electric fan 4 for introducing cooling air to the radiator 3 is provided on the front surface of the engine 1. On one end surface of the engine 1 main body, a crank pulley 5 provided at an end portion of a crank shaft 18, a cam pulley 6 provided at an end portion of a cam shaft of the engine 1, and a driving force from the crank pulley 5 to the cam pulley 6. And a timing belt 7 for transmitting the power.
A seal surface 20 with which the timing belt cover 8 abuts is formed on one end surface of the engine 1 around the power transmission device, and a lower portion extends to the vicinity of the rib 14 described below. The timing belt cover 8 is bolted to the sealing surface 20.
The space 17 is formed by the timing belt cover 8 and the one end surface of the engine 1 mounted on the upper side. here,
The timing belt 7 rotates in the direction from the rear bank to the front bank via the space between the banks in FIG. 2, and transmits power.

The timing belt cover 8 is the engine 1
Is formed by a flat surface portion 8a parallel to one end surface of the engine 1 and a flange portion 8b which is located around the flat surface portion 8a except the lower portion thereof and which is perpendicular to the end surface of the engine 1. An opening is formed in the lower portion of the flat surface portion 8a.

An air inlet 9 for introducing cooling air (running air) into the timing belt cover 8 is formed in the lower portion of the flange portion 8b located downstream of the electric fan 4.
Further, the flange portion 8b located in the front bank of the engine 1
At the position of the shortest distance between the timing belt cover 8 and the bonnet 10 on the upper surface of the, the air for cooling the timing belt 7 from the space 17 in the timing belt cover 8 to the outside of the timing belt cover 8 is drawn out. The outlet 11 is formed. The air outlet 11 has a rectangular shape, and the air outlet 11 is provided with a filter portion 22 around which a fitting rubber 21 is arranged.

On the crankshaft 18, the crank pulley 5
An oil pump 12 that supplies oil from the oil pan 19 to each part of the engine 1 is disposed between the engine 1 and the end surface of the engine 1. In order to prevent vibration and noise of the oil pump casing 13 due to the driving of the oil pump 12, a plurality of ribs 14 project below the crank pulley 5 from the oil pump casing 13 toward the timing belt cover 8. It is set up. Crankshaft 18
At the position above and outside the crank pulley 5, an accessory driving pulley 15 having a size that covers the rib 14 is attached. Therefore, the portion formed by the lower portion of the flange portion 8b of the timing belt cover 8, the ribs 14, the accessory drive pulley 15, and the one end surface of the engine 1 is used as the air introduction port 9.

The rib 14 connects the semicircular ribs 14a, 14a and 14b having a diameter larger than that of the semicircular ribs 14a, 14a located below the crankshaft 18, and
The ribs 14c are formed radially.

Timing belt cover 8 and bonnet 1
Behind the air outlet 11 provided at the shortest distance from 0, a wide space 23 is formed so that the distance between the timing belt cover 8 and the hood 10 is larger than the shortest distance. An intake pipe 16 is arranged between the front bank and the rear bank of the engine 1.

Cooling air introduced into the vehicle A through the front grill passes through a radiator 3 and an electric fan 4 arranged in front of the engine 1 to ventilate various parts in the engine room. The cooling air also hits the timing belt cover 8 located downstream of the electric fan 4, and the cooling air is introduced from the air introduction port 9. The cooling air introduced from the air inlet 9 flows in the same direction as the rotation direction of the timing belt 7 (clockwise in FIG. 1) along the ribs 14a and 14b. After passing through the air introduction port 9, the cooling wind hits the ribs 14c formed in a radial direction at substantially right angles to separate dust and air, and then the ribs 14c.
a, rib 14b, rib 14c, accessory drive pulley 15
It flows through the space B surrounded by and. After that, each time it hits the plurality of ribs 14c, air and dust are separated as described above. As a result, the ribs 14 act as dust separating means. The dust separated from the air falls to the lower portion of the rib 14b and is then discharged from between the rib 14b and the accessory drive pulley 15.

The cooling air, which is introduced from the air introduction port 9 and flows under the crank pulley 5 while being separated from the dust, is a space in the timing belt cover 8 through an opening formed in the lower portion of the timing belt cover 8. It is introduced into the space 17 and flows in the space 17 in the direction of arrow E in FIG. The cooling air flowing through the space 17 cools the timing belt 7.

As shown in FIG. 2, the cooling air obtained by cooling the timing belt 7 along the arrow E for a relatively long distance is supplied from the air outlet 11 located on the upper surface of the timing belt cover 8 of the front bank. Is derived. The air outlet 11 is provided at the position of the shortest distance between the timing belt cover 8 and the bonnet 10 on the upper surface of the timing belt cover 8 of the front bank, and further, behind the air outlet 11 is the shortest distance. Since the wider space 23 is formed, a negative pressure is generated in the vicinity of the air outlet 11, and the venturi effect acts to suck the cooling air from the space 17 in the timing belt cover 8, thereby cooling the air. Make it easy to derive the wind. In addition, the air outlet 11
The filter portion 22 attached to the belt prevents dust from entering the timing belt cover 8 from the outside of the timing belt cover 8 and damaging the belt.

According to this embodiment, since the air inlet 9 is provided below the flange portion 8b of the timing belt cover 8 facing the electric fan 4, the cooling air can be easily introduced without using a guide plate or the like. You can

In this embodiment, the air introduction port 9 is provided at the lower portion of the flange portion 8b of the timing belt cover 8 and the rib 1.
4, the auxiliary device driving pulley 15, and the end surface of the engine 1 are used as the parts, but they may be provided in the middle of the flange portion 8b of the timing belt cover 8 instead.

Further, the cooling air introduced from the air inlet 9 flows in the same direction as the rotation direction of the timing belt 7,
Downstream of the air inlet 9 and the crank pulley 5
A rib 14 as a reinforcement of the oil pump casing 13 is provided at a lower position of the timing belt cover, and the rib 14 is used as a dust separating means. Dust, water, etc. in the cooling air introduced into the inside 8 are separated here and do not adhere to the timing belt 7, and the durability of the timing belt 7 can be improved. Further, since the dust separating means (rib 14) is provided below the crank pulley 5, the dust separated from the air does not drop downward and does not adhere to the timing belt 7 located above. Although the dust separating means B is the rib 14 here, another filter may be provided to separate air from dust.

The cooling air separated from the dust is introduced into the space 17 inside the timing belt cover 8 through the opening at the bottom of the V-shaped timing belt cover 8, and the inside of the timing belt cover 8 is indicated by an arrow. As indicated by E, particularly in a portion surrounded by the outer surface of the timing belt 7, the one end surface of the engine 1 main body, and the timing belt cover 8, as the timing belt 7 rotates, the front portion is passed from the rear bank to the front portion between the banks. Since it flows toward the bank, the timing belt 7 is cooled over a longer distance as compared with the in-line engine, and the deterioration of the timing belt 7 due to heat can be further prevented. still,
Although the embodiment of the V-type engine is shown here, the above technique can also be applied to other in-line type engines.

Further, on the upper surface of the timing belt cover 8 located in the front bank and at the position of the shortest distance between the bonnet 10 and the timing belt cover 8, from the space 17 in the timing belt cover 8 to the outside of the timing belt cover 8. Since the air outlet 11 for discharging the cooling air is provided, and the space portion 23 wider than the shortest distance is formed behind the air outlet 11, a negative pressure is generated at this portion, and the venturi effect causes the inside of the timing belt cover 8 to be closed. Space part 1
Since the cooling air is sucked out from 7, the cooling air can be efficiently derived, and the timing belt cover 8
The hot air inside can be prevented.

A drive shaft 2 for transmitting the engine driving force to the tire is located behind the engine 1,
The air inlet 9 is provided on the front surface of the flange portion 8b of the timing belt cover 8 facing the electric fan 4, and the air outlet 11 is provided on the upper surface of the flange portion 8b of the timing belt cover 8, that is, Since the air inlet 9 and the air outlet 11 are not located at the position facing the drive shaft, there is no possibility that mud or dust splashed up by the drive shaft 2 will enter through the air inlet or the air outlet. Further, since the above-mentioned embodiment is the V-type engine,
Even if the mud or dust caused by the flip-up of the drive shaft 2 gets over the rear bank, it falls between the banks and does not enter the air outlet 11 provided on the upper surface of the timing belt cover 8 on the front bank side. The mud and dust are less likely to enter the air outlet 11.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a horizontal engine mounted on a vehicle.

FIG. 2 is a diagram in which a timing belt cover and an accessory drive belt of the engine of FIG. 1 are removed.

FIG. 3 is a sectional view of a main part of a dust separating unit.

4 is a sectional view taken along line IV-IV in FIG.

5 is a plan view of FIG. 1. FIG.

FIG. 6 is a view on arrow C in FIG.

FIG. 7 is a perspective view of a filter portion fitted into an air outlet.

[Explanation of symbols]

V-type engine ... 1, drive shaft ... 2, crank pulley ... 5, cam pulley ... 6, timing belt ...
7, timing belt cover ... 8, air inlet ... 9, bonnet ... 10, air outlet ... 11, rib (dust separating means) ... 14, space ... 17, space ... 23.

Claims (4)

[Claims] 1. A crankshaft of an engine is arranged in a vehicle width direction, and a crank pulley provided at an end portion of a crankshaft and a cam pulley provided at an end portion of a camshaft of the engine are provided on one end surface of the engine body. And a timing belt for transmitting the driving force from the crank pulley to the cam pulley, a power transmission device is provided, and a radiator for cooling the engine cooling water is arranged in front of the engine, and cooling air is introduced into the radiator. A timing belt cover is provided downstream of the cooling air that has passed through the electric fan and covers the power transmission device. By attaching the cover to one end surface of the engine body, a space is formed between the engine body and the engine belt. Air that is formed and that introduces cooling air into the space inside the timing belt cover at the bottom of the timing belt cover. In a timing belt cooling structure for an engine having an inlet, air for discharging the cooling air in the space above the timing belt cover on the upper surface of the timing belt cover at the shortest distance between the bonnet located above the engine and the timing belt cover. Provided with an outlet, provided downstream of the air inlet below the crank pulley in a direction substantially orthogonal to the flow of the cooling air introduced into the timing belt cover, to separate dust from air. Means for providing a timing belt cooling of the engine, characterized in that a space portion, which is surrounded by the engine and the bonnet and is formed wider than the shortest distance, is located behind the air outlet from the vehicle. Construction. 2. The dust separating means is a plurality of reinforcing ribs formed integrally with one end surface of the engine body, and the reinforcing ribs project from the one end surface side of the engine body toward the timing belt cover side. The timing belt cooling structure for an engine according to claim 1, wherein the timing belt cooling structure is provided. 3. A drive shaft for transmitting engine driving force to tires is located at the rear of the engine, the air inlet is provided on the front surface of a timing belt cover facing the electric fan, and the air outlet is provided. The timing belt cooling structure for an engine according to claim 1, wherein is provided on an upper surface of the timing belt cover. 4. The engine is a V-type engine having a front bank arranged closer to the bonnet and a rear bank arranged farther from the bonnet than the front bank, and the air outlet is The timing belt for an engine according to claim 3, wherein the timing belt is provided on an upper surface of a timing belt cover of the front bank, and the timing belt rotates in a direction from a rear bank to a front bank via a space between the banks. Cooling structure.