JPH08312311A - Cam shaft driving device of v-engine - Google Patents

Abstract

PURPOSE: To make an engine compact and taper a bon-net line toward the front side of a vehicle by shortening the body of the vehicle in the longitudinal direction in the case where a V-engine is placed in the cross direction of the vehicle. CONSTITUTION: A V-engine 1 comprises a first cylinder head 3 and a second cylinder head 4 tiltedly arranged on the cylinder block 2 at the lower section at the center section of the V-engine 1, a first bank F and a second bank R having a cylinder, in which a piston slides at an angle, formed. The V-engine 1 in this example is of a transverse type with a crank shaft being orthogonal to the longitudinal direction of the vehicle and the first bank F positioned frontward and a bon-net line B tiltedly arranged upward. The cylinder block 2 divided into an upper block 2a and lower block 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has two cylinder rows, and a VHC of the DOHC system in which the intake and exhaust camshafts are arranged on the cylinder heads of the respective cylinder rows.
Type engine camshaft drive device. More specifically, V when placed in the engine room of a car
Layout of a power transmission mechanism for driving a camshaft of a type engine.

[0002]

2. Description of the Related Art Conventionally, in order to drive the cam shaft of each bank in synchronism with the crank shaft in this type of V-type engine, as shown in, for example, Japanese Patent Laid-Open No. 60-230503, each bank has Of the two cam shafts provided,
It is known that either one is connected to a crankshaft via a timing belt, and the other camshaft is connected to one camshaft by a power transmission means such as another chain.

As a camshaft driving device for such a V-type engine, in addition to the type in which the camshafts located inside the Vbank are driven via the crankshaft as in the above publication, the camshaft is located outside the Vbank. There have been various proposals such as a type of driving cam shafts which are driven by a crankshaft (see Japanese Patent Application Laid-Open No. 60-261911).

[0004]

By the way, when an engine is mounted on an automobile, it is generally arranged in an engine room provided at the front of the automobile. Regarding the disposition direction, the crankshaft direction may be oriented in the front-rear direction of the vehicle body, or may be oriented in the orthogonal direction. Of these, the orientation in the orthogonal direction is generally referred to as a horizontal type.

In order to make the cabin, which is the occupant's living space, as wide as possible, in a vehicle employing this horizontal type, there is generally a demand for the power plant including the engine and the drive system to be as compact as possible in the longitudinal direction of the vehicle. is there.

In addition, when designing a vehicle body, there is a demand to widen the driver's field of view as much as possible in order to enhance safety, and also a demand to lower the bonnet line as much as possible toward the front side of the vehicle.

When a V-type engine as in the above-mentioned reference is mounted on a laterally mounted vehicle, a crankshaft rotates twice for a pulley (for belt driving) and a sprocket (for chain driving) provided on a camshaft. In the meantime, since the speed is reduced so as to make one rotation, the diameter becomes inevitably large. Therefore, in the case of driving the camshafts located inside the V bank, there is a problem that the overall height becomes high and it is difficult to lower the bonnet, or the case where the camshafts located outside the V bank are driven. However, there is a problem in that it is difficult to make the engine compact because the length in the vehicle front-rear direction becomes long.

The present invention has been conceived in order to solve the above problems. When a V-type engine is mounted on a laterally mounted vehicle, the length in the vehicle front-rear direction is shortened as much as possible to make the engine compact. It is an object of the present invention to provide a camshaft drive device for a V-type engine in which the hood line can be lowered toward the front side of the vehicle.

[0009]

The V of the invention according to claim 1
In a camshaft drive of a type engine, a first bank and a second bank each having a cylinder on which a piston slides are formed at an angle to each other, and a crankshaft direction is orthogonal to a vehicle front-rear direction. In the camshaft drive device of the V-type engine disposed inside, two camshafts are provided for each bank, and the camshafts located outside the Vbank of the first bank and the Vbanks of the second bank are provided. First power transmission wheels respectively provided on the cam shafts located inside,
Power transmission means engaged with the first power transmission wheel so as to transmit the rotational driving force of the crankshaft to the camshaft provided with the first power transmission wheel, and first power transmission in each bank. A second power transmission wheel which is provided on each cam shaft so as to transmit the rotational driving force transmitted to the cam shaft provided with the wheel to the other cam shaft and which has a diameter smaller than that of the first power transmission wheel; And the first bank is arranged on the front side of the vehicle and the second bank is arranged on the rear side of the vehicle. According to a second aspect of the present invention, there is provided a camshaft drive device for a V-type engine, wherein the second power transmission wheel is a gear.

[0010]

According to the first aspect of the present invention, the first bank having the first power transmission wheel on the camshaft located outside the V bank is arranged in the front, and the first bank is provided inside the V bank. Since the second bank in which the first power transmission wheels are provided on the camshaft located is arranged rearward, the bonnet can be inclined along the outer shape of the engine and lowered as it goes toward the front of the vehicle, and in the second bank Since the first power transmission wheels can be laid out inside the V bank, the length in the vehicle front-rear direction can be shortened, and the engine itself can be made compact.

According to the second aspect of the invention, since the second power transmission wheel is a gear, like a chain drive,
Even if the camshaft is not composed of at least three parts such as a sprocket and a chain part, it is composed of two parts of a gear provided on each camshaft, so that the upper part of the engine, which is strict in terms of layout, can be made compact. The invention according to claim 1 can be made more effective.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a schematic front view of a V-type DOHC engine, and FIG.
Is a front view of the main part with the belt cover removed, and FIG. 3 is a plan view of the main part with the head cover removed.

In a V-type engine 1, a first cylinder head 3 and a second cylinder head 4 are arranged on a lower cylinder block 2 in a slanted manner, and a piston (not shown) slides at an angle to each other. The first bank F and the second bank R that it has are formed. The V-type engine 1 of this example is of a horizontal type in which the crankshaft direction is mounted orthogonally to the front-rear direction of the vehicle, the first bank F is located at the front, and the bonnet line B is inclined upward. Is established. The cylinder block 2 is the upper block 2a.
And a lower block 2b.

Intake and exhaust valves (not shown) arranged in each cylinder
The valve operating mechanism for opening and closing is configured as a DOHC type in which two first to fourth cam shafts 6 to 9 are arranged in parallel on both upper sides of both cylinder heads 3 and 4, respectively. Then, at each end of the first cam shaft 6 on the exhaust valve side of the first bank F and the third cam shaft 8 on the intake valve side of the second bank R, there is a position protruding to one side of the banks F, R. The driving force of the crankshaft 10 is transmitted. That is, the cam pulleys 13 and 14 fixed to the end portions of both cam shafts 6 and 8 are engaged with the winding member 11 by the timing belt from the crank pulley 12 of the crank shaft 10, and the cam pulleys are synchronized with the engine rotation. The shafts 6, 8 are driven. In addition, 15 has shown the idle pulley.

Further, the second and fourth cam shafts 7 and 9 which are shorter than the first and third cam shafts 6 and 8 and are formed to have the length of the cylinder heads 3 and 4 have one side on each side. Inter-cam gear 16 for transmitting power between cam shafts in banks F and R
19 (helical gear) is arranged so that the second cam shaft 7 rotates at the same rotation speed with respect to the first cam shaft 6 and the fourth cam shaft 9 rotates at the same rotation speed with respect to the third cam shaft 8. It is meshed.

On the other hand, the cam shafts 6 to 9 are supported on the respective cylinder heads 3 and 4 by an integrated bearing member 21 at one end where the winding member 11 is engaged, and The tops of the cylinder heads 3 and 4 are covered with a head cover 22. The cam pulleys 13 and 14 and the winding member 11 are covered with a belt cover 23 attached to the side surfaces of the cylinder block 2 from the cylinder heads 3 and 4.

The detailed structure of the bearing member 21 is that of the first bank F, as shown in FIGS. 4 and 5, a first bearing portion 25 for the first cam shaft 6 and a second bearing portion 26 for the second cam shaft 7. And are connected and integrally formed. Then, fastening bolts are applied to the bolt holes 25a and 26a of the bearing portions 25 and 26, and the lower surface 21a is brought into contact with the upper surface of the cylinder head 3 to be fastened and fixed. The first cam shaft 6 has a first bearing portion 25.
The cam pulley 13 is disposed on the protruding portion. Further, the portion of the second bearing portion 26 corresponding to the shaft end portion of the second cam shaft 7 is a closing member 27 (see FIG. 3).
Is blocked by. Further, the seal portion 31a extends upward from the center side of the second bearing portion 26 and projects toward the front side, and is formed at the same height as the end surface of the second bearing portion 26. Further, a boss portion 28 for connection with the head cover 22 is formed in the upper center portion.

On the other hand, the detailed structure of the head cover 22 is that of the first bank F, as shown in FIG. 6 and FIG.
Has an opening 22a corresponding to the shape of the cylinder head 3
To the bearing member 21 in the opening 22a.
And the fastening bolt is tightened from the outer bolt hole 29 to integrally form the end face portion. Also,
A seal portion 31b is formed on the head cover 22 so as to protrude to the front side thereof along the protruding portion of the first cam shaft 6, that is, the outer circumference of the cam pulley 13. The end of the seal portion 31b on the center side is the seal portion 31 of the bearing member 21.
It is formed so as to be continuous with a.

The bearing member 21 and the head cover 22
The seal portions 31a and 31b of the above seal the outer peripheral portion of the belt cover 23, and as shown in FIG. 2, the end face of the cylinder head 3 is continuously sealed to the seal portion 31a of the bearing member 21. The portion 31c is formed, and the seal plate 30 is disposed on the other portions, straddling the cylinder heads 3 and 4 on both sides, and the seal portion 3 formed on the edge thereof.
1d, and further in the lower part, it is continuous with the seal portion 31e (see FIG. 1) formed on the cylinder block 2. Then, the peripheral edge of the belt cover 23 is pressed against the seal portions 31a to 31e, which are continuously formed along the outside of the winding member 11 as described above, via the seal material (rubber) to seal.

The bearing member 21 in the second bank R
The head cover 22 is basically the same as that of the first bank F, and the detailed description of the structure is omitted.
According to the structure of the above-described embodiment, the seal plate 3 is not installed on the head cover 22 and the seal portion 3 is not provided.
1a to 31c are directly formed on the bearing member 21, the head cover 22, and the cylinder heads 3 and 4, and the seal plate 30
It is designed to be compact by suppressing an increase in the axial length due to the formation of a gap when installing. Further, the support rigidity can be improved by integrally forming the bearing portions of the two cam shafts on the bearing member 21, and the rigidity can be increased by forming the seal portion 31a in a rib shape. Although the above-mentioned embodiment shows an example of a V-type engine, a DOHC engine such as an in-line engine can be similarly configured.

[Brief description of drawings]

FIG. 1 is a schematic front view of a V-DOHC engine according to an embodiment of the present invention.

FIG. 2 is a front view of a main part with a belt cover removed.

FIG. 3 is a plan view of an essential part with a head cover removed.

FIG. 4 is a front view of the bearing member.

FIG. 5 is a plan view of the bearing member.

FIG. 6 is a front view of a head cover.

FIG. 7 is a plan view of a main part of a head cover.

[Explanation of symbols]

 1 Engine 2 Cylinder Block 3, 4 Cylinder Head F, R Bank 6-9 Cam Shaft 10 Crank Shaft 11 Winding Member 12 Crank Pulley 13, 14 Cam Pulley 16-19 Cam Gear 21 Bearing Member 22 Head Cover 23 Belt Cover 25 1st Bearing portion 26 Second bearing portion 30 Seal plate 31a to 31e Seal portion

Claims (2)

[Claims] 1. A first cylinder having a cylinder on which a piston slides.
In the camshaft drive device of the V-type engine, in which the bank and the second bank are formed at an angle to each other, and the crankshaft direction is orthogonal to the vehicle front-rear direction and are arranged in the engine room, Two cam shafts are provided, and a first power transmission wheel and a crank are respectively provided on the cam shaft located outside the V bank of the first bank and the cam shaft located inside the V bank of the second bank. Power transmission means engaged with the first power transmission wheel so as to transmit the rotational driving force of the shaft to the cam shaft provided with the first power transmission wheel;
In each bank, each cam shaft is provided with a diameter smaller than that of the first power transmission wheel so that the rotational driving force transmitted to the cam shaft provided with the first power transmission wheel is transmitted to the other cam shaft. A second power transmission wheel, and the first bank is arranged on the front side of the vehicle, and the second bank is arranged on the rear side of the vehicle. 2. The camshaft drive device for a V-type engine according to claim 1, wherein the second power transmission wheel is a gear.