JP2001303965A - Dohc multicylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DOHC multicylinder engine miniaturizing the size by reducing the whole width and reducing the number of parts and the cost. SOLUTION: In this DOHC multicylinder engine, a camshaft is rotatably arranged in the top of an engine body, a plurality of auxiliary machines (water pump 44, power steering pump 45, etc.), rotated and driven by the crankshaft 6 are disposed in one side of the engine body, and a front cover 54 is attached to the side of the engine body where the auxiliary machines are disposed. The plurality of auxiliary machines are disposed within the width b of the engine body and one of the auxiliary machines (power steering pump 45) is attached to the front cover 54.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a DOHC multi-cylinder engine.

[0002]

2. Description of the Related Art For example, in an automobile engine, auxiliary equipment such as a power steering pump, a water pump, an alternator, and a compressor for an air conditioner are arranged on one side of the engine body, and these are rotated by a crankshaft.

[0003]

However, in the conventional engine, since a plurality of accessories are mounted on the side of the engine body via brackets, these accessories exceed the width of the engine body and extend outside the engine body. And the width of the entire engine is increased.

[0004] Further, since a bracket for attaching an auxiliary machine is required for each auxiliary machine, there is a problem that the number of parts increases and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a DOHC multi-cylinder capable of reducing the number of parts and cost while reducing the overall width and size. To provide an engine.

[0006]

According to a first aspect of the present invention, a camshaft is rotatably arranged on an upper portion of an engine body, and a plurality of auxiliary machines rotatably driven by a crankshaft are provided. Placed on one side of the engine body,
In a DOHC multi-cylinder engine in which a front cover is attached to one side of an engine body on which the auxiliary machine is arranged, the plurality of auxiliary machines are arranged within the width of the engine main body, and one of the auxiliary machines is connected to the engine. It is characterized by being attached to the front cover.

According to a second aspect of the present invention, in the first aspect of the invention, an auxiliary device attached to the front cover is a power steering pump.
According to a third aspect of the present invention, in the first or second aspect of the present invention, a bracket for attaching the accessory to the front cover is integrally formed, and the bracket is formed integrally with a cam bearing cap. It is characterized by being attached.

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, a housing of an auxiliary machine is formed integrally with the front cover.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the housing of the auxiliary machine is a volute of a water pump.

Therefore, according to the first or second aspect of the present invention, one of the accessories (power steering pump) is attached to the front cover, and all the accessories are arranged within the width of the engine body. The overall width of the cylinder engine can be reduced to reduce its size, and the number of brackets for attaching auxiliary equipment can be reduced to reduce the cost of the engine.

According to the third aspect of the present invention, since the accessory mounting portion of the front cover is supported by the cam bearing cap, the mounting rigidity of the accessory (power steering pump) is enhanced.

According to the invention described in claim 4 or 5, since the housing of the auxiliary equipment (the volute of the water pump) is formed integrally with the front cover, the number of parts can be further reduced and the cost can be reduced.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front view showing an arrangement structure of accessories of a DOHC multi-cylinder engine according to the present invention, FIG. 2 is a front sectional view of the DOHC multi-cylinder engine, and FIG. 3 is a valve mechanism of the DOHC multi-cylinder engine. It is a plane sectional view showing composition of.

V-type multi-cylinder engine 1 according to the present embodiment
Is a water-cooled four-cycle V-type eight-cylinder engine for an automobile, which is disposed horizontally at the front of the body of the automobile as shown in FIG. In FIG. 1, reference numeral 100 denotes a hood of an automobile, and 101 denotes a radiator.

Here, the internal structure of the V-type multi-cylinder engine 1 will be described with reference to FIG.

In the cylinder block 2 of the V-type multi-cylinder engine 1, four cylinders are arranged in a V-shape in a direction perpendicular to the paper surface of FIG. 2 (in the width direction of the vehicle body). 3 are formed respectively. And each cylinder 3
The piston 4 is slidably fitted to each of the
Each piston 4 is connected to a crankshaft 6 via a connecting rod 5. The crankshaft 6 is disposed in the crank chamber 7 in the direction perpendicular to the paper surface of FIG. 2 (vehicle width direction). The reciprocating linear motion of each piston 4 is converted into the rotational motion of the crankshaft 6 by the connecting rod 5. . Water jackets 8 are formed around the cylinders 3 of the cylinder block 2 so that cooling water can pass therethrough.

An oil pan 9 is attached to a lower portion of the cylinder block 2, and a cylinder head 10 is attached to an upper portion of each of the V-shaped cylinders of the cylinder block 2. An intake passage 11 is formed in each cylinder head 10 on the inner side (V bank side) of each cylinder, and an exhaust passage 12 is formed on the outer side. These intake passages 11 and exhaust passages 12 are Each is opened and closed at an appropriate timing by the exhaust valve 14,
Thereby, required gas exchange is performed in each cylinder 3.

That is, the intake valve 13 and the exhaust valve 14 are slidably inserted into and held by the cylinder head 10.
These are always urged to the closing side by the valve springs 15 and 16.

As shown in FIG. 3, an intake cam shaft 17 and an exhaust cam shaft 18 are provided on the intake side and the exhaust side of the upper surface of each cylinder head 10 in a direction perpendicular to the plane of FIG. The intake cam 17a and the exhaust cam 18a are formed in parallel and rotatable with each other, and are integrally formed for each cylinder.
Are in contact with valve lifters 19 and 20 which are respectively covered by upper ends of the intake valve 13 and the exhaust valve 14.
The intake camshaft 17 and the exhaust camshaft 18 are rotatably supported at their upper halves by bearing caps 21 and 22, respectively. The intake camshaft 17, the exhaust camshaft 18 and the bearing caps 21 and 22 are Each cylinder head 10 is covered by a head cover 23 attached to the upper surface.

In the V-type multi-cylinder engine 1 according to this embodiment, the intake valve 13 and the exhaust valve 1
The opening / closing timing of the valve 4 is variable. As shown in FIG. 3, a variable valve timing mechanism (hereinafter abbreviated as VVT) 2 is provided at each end of the intake camshaft 17 and the exhaust camshaft 18.
4, 25 are provided respectively. A sprocket 26 is provided on the VVT 25 on the exhaust side, and a sprocket 27 is connected to the exhaust camshaft 18.

A sprocket 28 having the same diameter as the sprocket 27 is provided on the VVT 24 on the intake side.
Timing chain 2 between both sprockets 27, 28
9 are wound.

On the other hand, as shown in FIG. 7, a sprocket 30 is attached to an end of the crankshaft 6,
A timing chain 31 is wound between the sprocket 30 and the sprocket 26. The timing chain 31 meshes with a sprocket 32 attached to the end of the balancer shaft.

When the V-type multi-cylinder engine 1 is started and the crankshaft 6 is driven to rotate, the rotation of the crankshaft 6 is controlled by the sprocket 30 and the timing chain 3.
1, transmitted through the sprocket 27 and the VVT 25 to the exhaust camshaft 18, and the rotation of the exhaust camshaft 18 is controlled by the sprocket 27, the timing chain 29, the sprocket 28
, And transmitted to the intake camshaft 17 via the VVT 24, and the two camshafts 17, 18 are rotationally driven. Then, the intake cam 17a and the exhaust cam 18a formed on the intake camshaft 17 and the exhaust camshaft 18 respectively press the valve lifters 19 and 20 against the urging forces of the valve springs 15 and 16 at appropriate timings, so that the intake valve 17 As described above, necessary gas exchange is performed in the cylinder 3 of each cylinder to push and open the exhaust valve 13 and the exhaust valve 14, and the opening and closing timing of the intake valve 13 and the exhaust valve 14 is controlled by the VVTs 24 and 25, respectively.

As shown in FIG. 2, a water jacket 33 through which cooling water passes is formed around the intake passage 11 and the exhaust passage of each cylinder head 10. A spark plug 34 is screwed to the top of the cylinder.
The electrode part at the tip of 4 faces the top of the combustion chamber S as shown. And, on the intake side of each cylinder head 10,
An injector 35 for injecting fuel is attached to each cylinder, and a fuel injection port (not shown) formed at the tip of each injector 35 opens to each intake passage 11.

An exhaust manifold 36 is connected to the exhaust passages 12 formed in the respective cylinder heads 10. The exhaust manifolds 36 join and are connected to an exhaust muffler (not shown).

On the other hand, an intake manifold 39 is connected to each of the intake passages 11 formed in each of the cylinder heads 10, and one end of each of the intake manifolds 39 opens into a surge tank 40 as shown in the figure. Although not shown, a throttle body and an air cleaner (not shown) are connected to the surge tank 40. The throttle body has a built-in throttle valve (not shown) that opens and closes by operating an accelerator.

Next, the gist of the present invention will be described with reference to FIGS.
It will be described based on. 4 is a perspective view of the front cover, FIGS. 5 and 6 are exploded perspective views of the cylinder head and the cam bearing cap, FIG. 7 is a front view of the front cover,
8 is a sectional view taken along line AA of FIG. 7, FIG. 9 is a sectional view taken along line BB of FIG. 7, and FIG. 10 is a sectional view taken along line CC of FIG.

V-type multi-cylinder engine 1 according to the present embodiment
As shown in FIG. 1, an air conditioner compressor 42, an alternator 43, a water pump 44, and a power steering pump (hereinafter referred to as a P / S pump) ) Is arranged within the width b of the engine body.
That is, the air conditioner compressor 42 and the alternator 43
Are arranged before and after the crankshaft 6 at the lower part of the engine body, the water pump 44 is arranged above the crankshaft 6 at the upper part of the engine body, and the P / S pump 45 is
Is disposed diagonally above the rear side of the vehicle body.

The pulleys 46, 47, 48, and 49 are respectively connected to the input shaft ends of the compressor 42 for the air conditioner, the alternator 43, the water pump 44, and the P / S pump 45. A V-belt 51 is wound between 46 to 49 and a pulley 50 connected to the crankshaft 6. Here, a desired tension is applied to the V-belt 51 by a tension pulley 52. Incidentally, 53 is an idler pulley.

Therefore, the rotation of the crankshaft 6 is controlled by the V-belt 5
1 and the pulleys 46 to 49, the air conditioner compressor 42, the alternator 43, the water pump 44
The air conditioner compressor 42, the alternator 43, the water pump 44, and the P / S pump 45 are respectively driven.

Here, the air conditioner compressor 42
The alternator 43 is disposed before and after the crankshaft 6 with the crankshaft 6 interposed therebetween, and these are attached to a lower portion of the cylinder block 2 via a bracket (not shown).

A front cover 54 for covering the VVTs 24 and 25 and the timing chain 31 is attached to one end of the engine body. As shown in FIG.
Cylindrical convex portions 54a, 54 for accommodating 4, 4 and 25
and a housing 54c and a housing 54c which constitute a volute of the water pump 44 in the upper center.
The discharge passage 54d connected to c is formed integrally. Here, the housing 54c is opened outward, and a cylindrical water inlet 54e and a semi-cylindrical bracket 54f are integrally formed before and after the housing 54c above the front cover 54. I have.
The bracket 54f is for mounting and supporting the P / S pump 45, and has three circular holes 5a.
5 are drilled.

On the other hand, as shown in FIG. 5, an end of an intake camshaft 17 and an end of an exhaust camshaft 18 are supported on one end (rear side of the vehicle body) of the cylinder head 10 on the side where the accessory is provided. A common cam bearing cap 56 is attached, but two brackets 56a and 56b are integrally provided upright on the upper portion of the cam bearing cap 56, and two circular holes 57 are vertically formed in one bracket 56a. One circular hole 57 is formed in the other bracket 56b.

As shown in FIG. 6, the other side (front of the vehicle body)
A common cam bearing cap 58 for supporting the ends of the intake camshaft 17 and the exhaust camshaft 18 is also mounted on one end of the cylinder head 10 on the side where the auxiliary equipment is provided. A thermostat housing 58a is formed integrally with the upper part.
As shown in FIGS. 5 and 6, solenoids 59 and 60 for controlling the VVTs 24 and 25 are attached to the cam bearing caps 56 and 58, respectively.

The water pump 45 has a housing (swirl chamber) 5 formed integrally with the front cover 54.
As shown in FIG. 10, the impeller 61 is accommodated in the housing 4c, and the housing 54c is assembled by covering the opening of the housing 54c with a cover 62. One end of a cooling water pipe 63 is connected to a suction port 54g opened in the housing 54c. ing. The other end of the cooling water pipe 63 is shown in FIGS.
Is connected to a thermostat 64 housed in a thermostat housing 58a formed integrally with the cam bearing cap 58, and the thermostat housing 58a is attached to the water inlet 54e formed integrally with the front cover 54. Have been.

The P / S pump 45 is supported by a bracket 54f formed integrally with the front cover 54, and is attached by a bolt (not shown) inserted into the circular hole 55 formed on the bracket 54f. The portion of the front cover 54 where the bracket 54f is formed is attached to the brackets 56a and 56b (only one is shown in FIG. 8) integrally formed with the cam bearing cap 56 as shown in FIG. That is, as shown in FIG. 7, three circular holes 65 are formed around the bracket 54 f of the front cover 54, and the bracket 54 f of the front cover 54 includes the circular hole 65 and the bracket of the cam bearing cap 56. The brackets 56a and 56b are attached to the brackets 56a and 56b by bolts (not shown) that pass through circular holes 57 formed in the holes 56a and 56b.

Thus, in the V-type multi-cylinder engine 1 according to the present embodiment, the auxiliary device (P / S pump) 45 is attached to the bracket 54f of the front cover 54, and the auxiliary All of the machines (that is, P / S
The pump 45, the compressor 42 for the air conditioner, the alternator 43, and the water pump 44) are connected to the width b of the engine body.
The DOHC multi-cylinder engine 1 can be reduced in size by reducing the overall width thereof, and a bracket for mounting the P / S pump 45 and the water pump 44 becomes unnecessary. Thus, the cost of the engine 1 can be reduced.

In the present embodiment, the front cover 5
Bracket 54f which is a mounting portion of the P / S pump 45 of No. 4
The mounting rigidity of the P / S pump 45 is increased because the configuration is adopted in which the parts are attached to brackets 56a and 56b formed integrally with the cam bearing cap 56 and are supported by the cam bearing cap 56.

Further, in this embodiment, the housing 54c constituting the volute of the water pump 44 is formed integrally with the front cover 54, so that the number of parts can be further reduced and the cost can be reduced.

It should be noted that the present invention has been described with particular reference to the V-type 8 for automobiles.
Although described as applied to a cylinder engine, the invention is equally applicable to any other application and type of DOHC multi-cylinder engine.

[0042]

As is apparent from the above description, according to the present invention, the camshaft is rotatably arranged on the upper part of the engine main body, and a plurality of auxiliary machines driven by the crankshaft are connected to one part of the engine main body. A DOHC multi-cylinder engine having a front cover attached to one side of the engine body on the side where the auxiliary machine is arranged, and arranging the plurality of auxiliary machines within the width of the engine body. Auxiliary equipment 1
Is attached to the front cover, the DOHC
The overall width of the multi-cylinder engine can be reduced to reduce its size, and the number of parts can be reduced and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing an arrangement structure of accessories of a DOHC multi-cylinder engine according to the present invention.

FIG. 2 is a front sectional view of a DOHC multi-cylinder engine according to the present invention.

FIG. 3 is a plan sectional view showing a configuration of a valve operating mechanism of the DOHC multi-cylinder engine according to the present invention.

FIG. 4 is a perspective view of a front cover of the DOHC multi-cylinder engine according to the present invention.

FIG. 5 is an exploded perspective view of a cylinder head and a cam bearing cap of the DOHC multi-cylinder engine according to the present invention.

FIG. 6 is an exploded perspective view of a cylinder head and a cam bearing cap of the DOHC multi-cylinder engine according to the present invention.

FIG. 7 is a front view of a front cover of the DOHC multi-cylinder engine according to the present invention.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

FIG. 9 is a sectional view taken along line BB of FIG. 7;

FIG. 10 is a sectional view taken along line CC of FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 V-type multi-cylinder engine 2 Cylinder block (engine body) 6 Crankshaft 10 Cylinder head (engine body) 17 Intake camshaft (camshaft) 18 Exhaust camshaft (camshaft) 42 Compressor (auxiliary equipment) for air conditioner 43 Alternator ( Auxiliary equipment) 44 Water pump (Auxiliary equipment) 45 Power steering pump (Auxiliary equipment) 54 Front cover 54c Housing (Swirl chamber of water pump) 54f Bracket 56 Cam bearing cap 56a, 56b Bracket b Engine body width

Claims (5)

[Claims] 1. A camshaft is rotatably arranged on an upper portion of an engine body, a plurality of auxiliary machines rotationally driven by a crankshaft are arranged on one side of the engine body, and a plurality of auxiliary machines are arranged on a side on which the auxiliary machines are arranged. In a DOHC multi-cylinder engine having a front cover attached to one side of an engine body, the plurality of accessories are arranged within the width of the engine body, and one of the accessories is attached to the front cover. DOHC multi-cylinder engine. 2. The DOHC multi-cylinder engine according to claim 1, wherein the auxiliary device attached to the front cover is a power steering pump. 3. The front cover according to claim 1, wherein a bracket for attaching the auxiliary device is formed integrally with the front cover, and the bracket is attached to a bracket formed integrally with the cam bearing cap. D
OHC multi-cylinder engine. 4. A housing according to claim 1, wherein an auxiliary machine housing is formed integrally with said front cover.
The DOHC multi-cylinder engine described. 5. The DO according to claim 4, wherein the housing of the accessory is a volute of a water pump.
HC multi-cylinder engine.