JPH0586975A - Case structure for engine - Google Patents

Abstract

PURPOSE:To provide the case structure of an engine which effectively suppresses vibration of a front case through simple constitution. CONSTITUTION:A confluence passage 20 communicated to a cooling water takeoff port 18 and served to cause joining of cooling water from a water jacket 19 of a cylinder head 2a to return it to a radiator provided between cylinder heads 2a. The confluence passage 20 runs in an arch-form manner across the front side of a cylinder head front case 3. Since a wall part 37 is formed integrally with the front case 3 so that a through-hole 23 for the flow of cooling water is formed, rigidity of the front case 3 itself is increased. Simultaneously, since this part is fixed to an engine body 2 by means of a through- bolt 27 togetherwith the confluence passage, a problem on membrane vibration of the front case 3 can be solved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case structure of an engine, and more particularly to a front case for covering a timing chain or a timing belt provided on the front side of the engine.

[0002]

2. Description of the Related Art In an engine cooling mechanism, cooling water is introduced into the engine from a cooling water inlet provided in a cylinder block by a cooling water pump, taken out from a cooling water outlet provided in a cylinder head, and then discharged to a radiator. Sent. The cooling water outlet of the V-type engine is provided in the cylinder head of each bank. Therefore, in order to return the cooling water from the engine to the radiator, it is common to combine the cooling water from each bank and then return the cooling water to the radiator.

Such a confluent passage for the cooling water is actually developed by Shokai 59.
-88213. In this disclosure, the cooling water outlet and the merging passage are provided on the rear side of the engine, that is, on the flywheel side. Also,
A timing chain or timing belt is provided on the front side of the engine, and a front case is attached to cover these mechanisms. This front case is mounted by fixing the peripheral part to the engine.

[0004]

[Problems to be Solved] However, since the central portion of the front case is not supported, the central portion of the front case vibrates during operation of the engine, so-called membrane vibration occurs,
There is a problem that it becomes a noise source. The present invention has been made in view of the above circumstances, and an object thereof is to provide an engine case structure capable of effectively suppressing the above-mentioned membrane vibration of the front case with a simple structure.

[0005]

In order to solve the above problems, the present invention is configured as follows. An engine case structure according to the present invention includes a V-type engine having a cooling water outlet on the front side of a cylinder head of each bank, a front case for covering a mechanism on the front side of the engine, and an outside of the front case. And a merging passage that extends through the bank and connects the cooling water outlet of each bank.

In a preferred aspect, a part of the confluence passage is formed in the front case, and the passage portion formed in the front case is connected to the cooling water outlet. In still another aspect, the merging passage extends through the front case and is connected to the cooling water outlet. Further, preferably, the combined cooling water outlet is provided in the vicinity of the connecting portion of the cylinder head with the cylinder block.

The present invention can be suitably used when the front side mechanism is a chain mechanism.

[0008]

According to the above-mentioned structure of the present invention, the front case is connected with the confluence passage which is connected to the cooling water outlet formed on the front side of the engine cylinder head, and is preferably a pipe member. .. The merging passage is located relatively in the center of the front case. Therefore, the front case is supported by the merging passage in the central portion thereof, and conversely, the merging passage is supported by the front case in the vicinity of the cooling water outlet. Cooling water is introduced from the radiator to the water pump, goes around from the water jacket of the cylinder block to the water jacket of the cylinder head, and from the cooling water outlet provided on the front side of the cylinder head through the confluence passage to cool from each bank. After the water is collected, it is returned to the radiator. In the configuration of this example, the cooling water outlet is provided near the connection portion of the cylinder head with the relatively high-strength cylinder block, so that the support portion of the merging passage is strong, and therefore the support state of the front case is also strong. Becomes Furthermore, the mechanism housed in the front case is a chain.
In the case of the chain mechanism, the oil dispersedly supplied to the front case for lubricating the chain mechanism adheres by colliding with the confluence passage passing through the inside of the front case, so that the dispersed oil is easily collected. There are also advantages. Further, by providing the cooling water outlet on the front side rather than the rear side, the layout of the communication passage to the radiator can be made compact.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The engine according to one embodiment of the present invention is a V-type 6 cylinder engine. In this structure, the cylinder head is attached to each bank. FIG. 1 shows an engine 1
FIG. 3 is an elevation view of the front side of FIG. The front side of the engine body 2 is covered with a front case, and a chain mechanism for driving a valve mechanism is housed in a space surrounded by the end surface of the engine body and the front case. The front case includes two cylinder head front cases 3 attached to the front surfaces of the cylinder heads 2a of each bank,
It consists of three cylinder block front cases 4 mounted on the front surface of the cylinder block.

The cylinder head front case 3 is provided with projections 3a and 3b for accommodating drive mechanisms for an intake camshaft (not shown) and an exhaust camshaft (not shown), respectively. The front cases 3 and 4 are attached to the front end surface of the engine body 2 by bolts 5 around the peripheries. A crankshaft 6 of the engine extends through the cylinder block front case 4, and a pulley 7 for transmitting a driving force to an auxiliary machine is attached to a front end of the crankshaft 6. An oil pan 8 is attached to the lower part of the cylinder block, and a pulley 9 for driving an oil pump projects from the oil pan 8 to the front side. An oil filter 10 is provided on the side of the oil pan 8.

An alternator 13 is attached to one side of the engine 1 via brackets 11 and 12. A drive pulley 14 is attached to the front side of the alternator 13. Alternator 13
On the side of the engine 1 opposite to the side where
An air conditioner driving pulley 15 is arranged. A mechanical supercharger 16 is provided between the banks at a position slightly offset from the symmetry axis L of the engine toward one of the banks. On the side of the supercharger 16, a supercharged air outlet pipe 1 is provided.
7 are arranged adjacent to each other.

Further, between the two cylinder heads 2a,
A merging passage 20 is provided which communicates with the cooling water outlet 18 from the cylinder head 2a and joins the cooling water from the water jacket 19 of the cylinder head 2a to return it to a radiator (not shown). The merging passage 20 crosses the front side of the cylinder head front case 3 in an arch shape. A cooling water outlet pipe 21 for returning the cooling water from the merging passage 20 to a radiator (not shown) is connected to one end of the merging passage 20, and a cooling water return pipe 22 for connecting the heater is connected. To be done. Referring to FIG. 2, the front end of the merge passage 20 is connected to the front case 3 in a fitted state. The front case 3 is formed with a through hole, that is, a cooling water passage 23, which connects the confluence passage 20 and the water jacket 19 of the cylinder head 2a. A flange portion 25 having a bolt hole 24 is formed at the tip of the confluence passage 20, and a through bolt hole 26 corresponding to the bolt hole 24 is formed in the front case 3. And the merging passage 20 is
It is fixed to the engine body 2, that is, the cylinder head 2a by a through bolt 27 extending from the flange portion 25 through the through hole 26. In addition, this cylinder head 2
The cooling water outlet of a is provided in the vicinity of a highly rigid portion of the connecting portion between the cylinder head 2a and the cylinder block.

A water pump 28 having a center on the axis of symmetry L is provided in the valley portion of the bank below the merging passage 20, and the water pump 28 is provided between the merging passage 20 and the front end surface of the engine body. Cooling water intake pipe 2
9 is located. This pipe 29 has a turbocharger 1 with respect to the symmetry axis L.
It is offset to the side opposite to the side where 6 is arranged. The pipe 29 has a cooling water pipe 3 to a heater (not shown).
0 is connected.

The belt 31 for driving the supercharger travels from the crank pulley 7 to a pulley (not shown) coaxial with the air conditioner drive pulley 15 (not shown) to drive the supercharger.
Have been hung over. An idler pulley 32 is provided between the crank pulley 7 and the supercharger driving pulley 16a to adjust the tension of the belt 31. In this case, the supercharger drive pulley 16a and the air conditioner drive pulley 15 are located on the opposite sides of the axis of symmetry L, so that interference with other auxiliaries is avoided and the belt 31 is stretched. The angle can be made acute, and power can be efficiently transmitted.

The air conditioner driving pulley 15 is connected to the crank pulley 7 by a belt 33, and an idler pulley 34 is provided between them to adjust the belt tension. The alternator 13 and the drive pulley 9 of the oil pump are driven via a belt 35 by a drive pulley (not shown) provided coaxially with the air conditioner drive pulley 15. In this case, the tension is adjusted by the idler pulley 36.

According to the above construction, the front case 3 is integrally provided with the wall portion 37 for forming the through hole 23 for circulating the cooling water, so that the rigidity of the front case 3 itself is increased and this portion is passed through. Since it is fixed to the engine body 2 together with the merging passage by the bolt 27, the problem of membrane vibration of the front case 3 can be solved. Further, since such a strong merging passage is provided so as to connect the highly rigid portion of the cylinder head 2a, it is possible to improve the support strength of the cylinder head 3 of the engine.

Referring to FIG. 3, there is shown another structure of the connection portion of the merge passage 20 according to the present invention. In the structure of this example, the front end of the confluence passage 20 penetrates the front case 3 and is directly connected to the cooling water outlet 18 of the cylinder head 2a.
Connected to. Also in this case, the merging passage 20 is provided with the flange portion 25 having the bolt hole 24 as in the previous example, while the front case 3 is provided with the bolt through hole 26. And, the front case 3 is the through bolt 2
It is attached to the engine body 2 integrally with the confluence passage 20 by 7.

Also in this example, the reinforcing effect of supporting the cylinder head 2a as well as the reinforcing effect of the front case 3 similar to the previous example can be obtained.

[0019]

According to the present invention, since the merging passage is fixed to the front case, the front case can be supported, and the merging passage is also supported by the front case. In other words, because the structure supports each other,
The problem of surface vibration of the front case can be solved, and the supporting rigidity of the cylinder head can be improved.

Preferably, the merging passage is provided in a portion having a high strength of the cylinder head, and thus, the strength of supporting the cylinder head can be further improved by doing so. By providing a part of the merging passage in the front case, the rigidity of the front case itself can be increased, and therefore the problem of membrane vibration can be effectively solved. If the mechanism housed in the front case is a chain mechanism, the chain mechanism is lubricated so that the oil dispersedly supplied to the front case does not adhere to the confluence passage passing through the front case. This makes it easier to collect the dispersed oil. Further, by providing the cooling water outlet on the front side rather than the rear side, the layout of the communication passage to the radiator can be made compact.

[Brief description of drawings]

FIG. 1 is an elevation view of an engine front side according to an embodiment of the present invention,

FIG. 2 is a partial cross-sectional view of a connection portion of a merging passage,

FIG. 3 is a partial cross-sectional view of a connecting portion of a merging passage according to another embodiment.

[Explanation of symbols]

 1 Engine 2 Engine Main Body 3 Cylinder Head Front Case 4 Cylinder Block Front Case 5 Bolt 6 Crank Shaft 7 Crank Pulley 8 Oil Pan 9 Pulley 10 Oil Filter 11 Bracket 12 Bracket 13 Alternator 14 Pulley 15 Pulley 16 Supercharger 17 Supercharger Outlet Piping 18 Cooling water outlet 19 Water jacket 20 Confluence passage.

Claims (5)

[Claims] 1. A V-type engine having a cooling water outlet on the front side of a cylinder head of each bank, and a front case for covering a mechanism on the front side of the engine.
An engine case structure comprising: a converging passage extending through the outside of the front case to connect the cooling water outlets of the banks. 2. The engine according to claim 1, wherein a part of the confluence passage is formed in the front case, and a passage portion formed in the front case is connected to the cooling water outlet. Case structure. 3. The engine case structure according to claim 1, wherein the merging passage extends through the front case and is connected to the cooling water outlet. 4. The engine case structure according to claim 1, wherein the combined cooling water outlet is provided in the vicinity of a connecting portion of the cylinder head with the cylinder block. 5. The engine case structure according to claim 1, wherein the front side mechanism is a chain mechanism.