JPH08105306A - V-engine for automobile - Google Patents

Abstract

PURPOSE: To provide a compact cylinder head while reducing the disorder in the opening and closing timing of respective intake valves and the opening and closing timing of respective exhaust valves. CONSTITUTION: Two rows of cylinders are disposed in V-type and two cam shafts, cam shaft 19 for driving an intake valve and a cam shaft 20 for driving an exhaust valve are provided on the respective rows of cylinders. The cam shaft for driving the same kind valve of two cam shafts on the respective rows of cylinders is connected to a crankshaft 8 through a first transmitting means for receiving power from a single endless transmitting belt 26, while two cam shafts, the cam shaft for driving the intake valve and the cam shaft for driving the exhaust valve on the respective rows of cylinder are connected to each other through an endless transmitting belt 29 of a portion of a second transmitting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-type engine for an automobile, in which each cylinder row is provided with an intake valve driving cam shaft and an exhaust valve driving cam shaft, and particularly to an intake valve driving cam shaft and an exhaust valve driving engine. The present invention relates to the structure of a transmission device that drives a valve operating device such as a cam shaft.

[0002]

2. Description of the Related Art Conventionally, a V-type engine provided with an intake valve driving cam shaft and an exhaust valve driving cam shaft for each cylinder row is disclosed, for example, in Japanese Utility Model Laid-Open No. 57-176604. There is. This V-type engine valve operating device has two valve-driving camshafts provided in each cylinder row.
The structure is such that it is connected to the crankshaft via a book timing chain, and a timing chain is provided for each cylinder row.

[Problems to be Solved by the Invention]

However, the conventional V having such a configuration is used.
In a type engine, two valve driving cam shafts in each cylinder row are equipped with sprockets each having an outer diameter approximately twice that of a crank chain timing chain sprocket. The sprockets must be separated from each other so they do not touch each other. Therefore, there is a limit to downsizing the cylinder head.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to reduce the size of the cylinder head, open / close timing of each intake valve, and each exhaust. An object of the present invention is to provide a V-type engine for an automobile in which the valve opening / closing timing is less likely to occur.

[0005]

In order to achieve the above-mentioned object, a V-type engine for an automobile according to the present invention has two cylinder rows arranged in V-type, and an intake valve driving camshaft for each cylinder row. And a camshaft for driving an exhaust valve, the V-type engine for an automobile, wherein the camshaft for driving the same valve and the crankshaft of the two camshafts in each cylinder row are combined into a single engine. The first transmission means to which power is transmitted by the endless transmission belt is connected, and the two cam shafts of the intake valve driving cam shaft and the exhaust valve driving cam shaft of each of the cylinder rows are connected to each other by the second transmission means. It is characterized by being connected by an endless power transmission band which is a part.

[0006]

Since it is the V-type engine for an automobile constructed as described above, the power transmission rotor of the second transmission means coupled to the camshaft is replaced with the power transmission rotor of the camshaft in the first transmission means. By forming it with a smaller diameter, the outer dimensions of the second transmission means are reduced. Further, in the first transmission means, the valve drive camshaft which is interlocked with the rotation of the crankshaft is the same type valve drive camshaft. Therefore, the endless transmission bands of the first transmission means and the second transmission means are slightly expanded and contracted. Even if there is a difference, the intake valve driving cam shaft and the exhaust valve driving cam shaft are simultaneously rotated by the first transmission means and the second transmission means simultaneously between the same type valve drive cam shafts.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of an engine compartment of an automobile, in which an engine 3 and a transmission 4 are mounted inside a left and right wheel wall 2, 2 by an auxiliary frame 5. 6
Is a radiator disposed in front of the engine compartment, and 7 is an electric cooling fan.

The engine 3 is a V-type 6-cylinder engine in which the crankshaft 8 is arranged in the left-right direction of the vehicle, and cylinder rows are arranged in front of and behind it. That is, as shown in FIG.
The front and rear cylinder rows each have a combustion chamber 14 formed by a cylinder 10, a cylinder head 12 and a piston 13, and each combustion chamber 14 has two intake passages 16 via two intake valves 15. Similarly, two exhaust passages 18 are connected to each other via two exhaust valves 17.

Reference numeral 19 is an intake valve driving cam shaft for driving the intake valve 15, 20 is an exhaust valve driving cam shaft for driving the exhaust valve 17, and the intake valve driving cam shaft 19 is arranged in a V shape. The cylinders 10, 10 are arranged inside, and the exhaust valve driving cam shaft 20 is arranged outside.

The intake passage 16 is provided with two pipe lines having different lengths for each combustion chamber. Reference numerals 21 and 21 denote intake distribution boxes that form the upstream ends of the intake passages 16 and are attached to the upper portions of the cylinder heads 12 of the respective cylinder rows. Of the two intake passages 16, one short pipe path is directly above the intake passages. One long pipeline is connected to the intake distribution box 21, and is connected to the intake distribution box 21 of the cylinder row on the other side.

An exhaust pipe 22 forms a part of the exhaust passage 18 and extends downward from each cylinder row. The exhaust pipe 22 of the front cylinder row extends rearward via an exhaust purification catalyst 24 arranged on the lower surface of the crank box 23, and the exhaust pipe 22 of the rear cylinder row has an exhaust purification catalyst 25 arranged rearward of the crank box 23. Through the back, after the two have joined,
It is opened to the atmosphere through an exhaust silencer (not shown).

Next, the structure of the device for driving the intake valve driving cam shaft 19 and the exhaust valve driving cam shaft 20 will be described. The two intake valve driving cam shafts 19 arranged inside the V bank protrude outward from one side of the cylinder head 12, and the first driven pulley 19a is fixed thereto.
The first driven pulley 19a is driven by the first drive pulley 8a attached to the crankshaft 8 via the first timing belt 26 with teeth which constitutes a part of the first transmission means. Reference numeral 27 is a tension pulley for tensioning the belt 26 during the first adjustment, and 28 is a belt cover.

The first transmission means according to the present invention is a first driven pulley 1 attached to each intake valve driving cam shaft 19, 19.
9a, a first drive pulley 8a for the crankshaft 8, the first drive pulley 8a and the first driven pulleys 19a, 19a.
It is composed of a single first timing belt 26 and the like as a single endless power transmission belt wound around and.

From the other side of the cylinder head 12, an intake valve driving cam shaft 19 and an exhaust valve driving cam shaft 20 project to the outside, and the intake valve driving cam shaft 19 has a second driving pulley. 19b, and the exhaust valve driving cam shaft 20 has a second
The driven pulleys 20a are fixed. And
The two pulleys are connected to each other by a second timing belt 29 of an endless transmission belt which constitutes a part of the second transmission means.
30 is a belt cover and 31 is a tension pulley.

The second transmission means according to the present invention comprises a second drive pulley 19b mounted on the side of the intake valve drive camshaft 19 opposite to the first driven pulley 19a, and an exhaust valve drive means. Second driven pulley 20a attached to the camshaft 20
And a second timing belt 29 of an endless transmission belt wound around these pulleys. And the second
The second drive pulley 19b and the second driven pulley 20a of the transmission means are formed to have the same diameter as each other and have a smaller diameter than the first driven pulley 19a of the first transmission means.

In the V-type engine constructed as described above,
The rotation of the crankshaft 8 is transmitted to the two intake valve driving cam shafts 19 arranged inside the V bank by one first timing belt 26 and the first driven pulley 19a. Two intake valve driving cam shafts 19 and two exhaust valve driving cam shafts 2
0 is the second drive pulley 19b and the second driven pulley 2 arranged on the other side of the engine (the side opposite to the first transmission means).
0a and the second timing belt 29 of the endless transmission band wound around them rotate while maintaining a specific phase.

As described above, the intake valve driving cam shaft 19 and the exhaust valve driving cam shaft 20 of each cylinder row rotate in association with the rotation of the crankshaft 8. Therefore, the second drive pulley 19b and the second driven pulley 2 of the second transmission means connected to the intake valve driving cam shaft 19 and the exhaust valve driving cam shaft 20.
0a is the intake valve drive cam shaft 19 in the first transmission means.
By forming the first driven pulley 19a to have a smaller diameter than the first driven pulley 19a, the outer dimensions of the entire second transmission means can be reduced.

In the above embodiment, the intake valve drive cam shafts 19 and 19 are used as the valve drive cam shafts interlocked with the rotation of the crankshaft 8 in the first transmission means. The exhaust valve driving cam shafts 20, 20 may be selected. In any case, since the same type valve driving camshafts are simultaneously rotated by the first or second transmission means, the opening and closing intervals of the same type valves and the opening and closing phase difference between the different valves of both banks are exceptional. No unevenness occurs.

[0019]

The V-type engine for an automobile according to the present invention is
The same type valve driving camshaft of the two camshafts of each cylinder row and the crankshaft are connected by the first transmission means through which power is transmitted by a single endless transmission band, and the intake valve drive of each cylinder row is performed. Since the two cam shafts of the driving cam shaft and the exhaust valve driving cam shaft are connected by the endless transmission belt which is a part of the second transmission device, the rotation of the second transmission device coupled to the cam shaft for power transmission. By forming the body to have a smaller diameter than the rotary body for power transmission of the camshaft in the first transmission means, the external dimensions of the second transmission means become smaller, so that the camshaft on the V bank side approaches the other camshaft. Therefore, the distance between the two cam shafts can be narrowed. Therefore, the cylinder head can be downsized.

Further, in the first transmission means, the valve driving camshaft which is interlocked with the rotation of the crankshaft is the same kind of valve driving camshaft, so that the endless transmission bands in the first transmission means and the second transmission means are slightly different from each other. Even if there is a difference in expansion and contraction between the intake valve driving camshaft and the exhaust valve driving camshaft, the same valve driving camshafts are simultaneously rotated by the first or second transmission means. There is no particular unevenness in the opening / closing interval between the same type valves and the opening / closing phase difference between different types of valves in both banks, and the intake valve and the exhaust valve reliably perform the desired opening / closing operation, and are excellent V-type engines for automobiles. Become.

[Brief description of drawings]

FIG. 1 is a plan view of an engine compartment of an automobile equipped with an automobile V-type engine according to the present invention.

FIG. 2 is a side view in which a part of the engine compartment in FIG. 1 is cut away.

3 is a cutaway side view of the engine compartment of FIG. 1. FIG.

FIG. 4 is a layout view showing a layout of belts.

5 is a sectional view taken along line VV in FIG.

[Explanation of symbols]

 8 Crankshaft 8a 1st drive pulley 19 Intake valve drive camshaft 19a 1st driven pulley 19b 2nd drive pulley 20 Exhaust valve drive camshaft 20a 2nd driven pulley 26 1st timing Belt 29 Belt for second adjustment

Claims (1)

[Claims] Claims: 1. Two cylinder rows are arranged in a V-shape, and each cylinder row has an intake valve driving cam shaft and an exhaust valve driving cam shaft.
A V-type engine for an automobile provided with two camshafts, wherein power is transmitted by a single endless transmission band between the camshafts for driving similar valves of the two camshafts of each cylinder row and the crankshaft. In addition to being connected by the first transmission means, the two cam shafts of the intake valve driving cam shaft and the exhaust valve driving cam shaft of each of the cylinder rows are connected by an endless transmission band which is a part of the second transmission means. A V-type engine for automobiles characterized by the following.