JPH08270410A - Auxiliary drive device of internal combustion engine - Google Patents

Abstract

PURPOSE: To improve a structure for driving a fuel pump or the like with a camshaft in an engine of an automobile. CONSTITUTION: While a cam shaft 10 is provided on the end with a camshaft journal 20, the outer periphery of the camshaft journal 20 is supported on a cam housing 22. The camshaft journal 20 is formed on the end with a recessed groove 21 in which a shaft 17 of a coupling 16 mounted on a rotary shaft of a fuel pump 18 is fitted connectively. Since vibrations in the rotation of the cam shaft 10 are received by the cam housing 22, the vibration is not generated in the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary machine drive device for an internal combustion engine, which drives a fuel pump, a distributor, a rotation angle sensor or the like.

[0002]

2. Description of the Related Art An auxiliary machine such as a fuel pump, a distributor or a rotation angle sensor needs to be driven in synchronization with the rotation of the crankshaft of an engine. Therefore, for example, an auxiliary machine such as a fuel pump is driven by driving a sprocket attached to its drive shaft and a sprocket attached to a crankshaft by a chain. In this way, the auxiliary machinery may be directly driven by the crankshaft, but it may be synchronized with the rotation of the camshaft provided so as to rotate synchronously with the crankshaft from the beginning. When synchronizing the rotation of the camshaft in this way, it is usual to connect the accessory directly to the camshaft.

Referring to FIG. 4, a conventional one in which an auxiliary machine is driven by a camshaft will be described. Reference numeral 1 is a cylinder head, and 2 is a cylinder head cover provided above the cylinder head cover. A plurality of vertical holes 3 are formed in the cylinder head 1, and a stem 6 of a valve 5 passes through the hole 3 via a stem guide 4 so as to be vertically movable. Reference numeral 7 is a valve head, and 8 is a valve lifter. A cam housing 9 is provided inside the cylinder head cover 2 at a position between the two valves 5, and rotatably supports the cam shaft journal 11 of the cam shaft 10. The valve lifter 8 is in contact with the cam 12 of the camshaft 10. Reference numeral 13 is a spring that presses the valve lifter 8 toward the camshaft 10.

A camshaft journal 14 is also provided at the end of the camshaft 10, and the shaft 1 of the coupling 16 is fitted in a groove 15 provided in the camshaft journal 14.
7 is inserted. A fuel pump 18 as an auxiliary machine is supported on the side portions of the cylinder head 1 and the cylinder head cover 2, and a drive shaft (not shown) of the fuel pump 18 is connected to the coupling 16. As a result, when the camshaft 10 rotates, its rotational force is transmitted to the fuel pump 18 via the coupling 16. An oil passage 19 is provided inside the camshaft 10 as indicated by a broken line.

[0005]

In the conventional accessory drive system having such a structure, particularly in the case of a four-valve type engine as shown in the drawings, the cams 9 are provided on both sides of the cam housing 9, so that the rotation of the cams causes the cams 12 to rotate. There is a problem in that vibration is likely to occur around the cam housing 9 as a fulcrum. Therefore, it is necessary to increase the strength of this portion to suppress the vibration. The present invention has been made in view of this point, and it is an object of the present invention to provide an accessory drive device for an internal combustion engine, which suppresses vibration when the accessory is driven without particularly increasing strength. Is.

Examples of those in which a distributor as an auxiliary machine is connected to a camshaft are Japanese Utility Model Publication Nos. 5-41265, 5-41267 and 61-61.
It is disclosed in Japanese Patent No. 32574. However, these inventions are all devised so that the length of the engine is not increased by mounting the distributor on the camshaft, and when the auxiliary machine is driven, which is intended by the present invention. It is not intended to suppress the vibration of.

[0007]

As a means for solving the above-mentioned problems, the present invention provides a camshaft journal at the end of a camshaft and supports the outer periphery of the camshaft journal with a cam housing. It is characterized in that a groove is formed at the end of the journal and a coupling shaft attached to the rotary shaft of the auxiliary machine is inserted and coupled.

[0008]

By virtue of the camshaft journal provided at the end of the camshaft and supported by the cam housing, and the auxiliary machinery connected to the camshaft journal via a coupling, vibration generated when the camshaft rotates can be received by the cam housing. Therefore, no external vibration is generated. The auxiliary machine is rotationally driven by the rotational force of the cam shaft given through the coupling.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described with reference to FIG.
The same parts as those in FIG. In the present invention, the camshaft journal 20 is provided at the end of the camshaft 10. As shown in FIGS. 2 and 3, a substantially rectangular concave groove 21 is formed in the end of the camshaft journal 20. Groove 21
A shaft 17 of the coupling 16 is fitted in the shaft. In addition,
A cam housing 22 is provided on the outer periphery of the camshaft journal 20 and rotatably supports the camshaft journal 20.

A fuel pump 18 as an auxiliary machine is supported on the side portions of the cylinder head 1 and the cylinder head cover 2, and a drive shaft (not shown) of the fuel pump 18 is connected to the coupling 16. . As a result, when the camshaft 10 rotates, its rotational force is transmitted to the fuel pump 18 via the coupling 16. An oil passage 19 is provided inside the camshaft 10 as indicated by a broken line.
Is provided and is connected to a branch portion 19a that is obliquely provided so as to avoid the concave groove 15 as shown in FIG. As a result, the lubricating oil is discharged between the cam housing 22 and the camshaft journal 20.

In such a structure, the camshaft 10
When is rotated, the rotational force is transmitted from the camshaft 10 to the fuel pump 18 via the coupling 16.
The coupling of the coupling 16 to the camshaft 10 is performed by the camshaft journal 20 supported by the cam housing 22.
Since the vibration is generated in the portion (1), the vibration generated by the rotation of the camshaft 10 is suppressed by the cam housing 22 and is not transmitted to the outside.

In the embodiment described above, the fuel pump is used as an auxiliary machine, but the present invention is not limited to this, and any type can be used as long as it is driven by a shaft. In addition to fuel pumps, distributors and rotation angle sensors can be considered.

[0013]

As described above, the present invention occurs when the camshaft rotates by providing the camshaft journal at the end of the camshaft and supporting it by the cam housing, and connecting the auxiliary machine to that portion. Since the vibration is received by the cam housing, no vibration is generated outside. By providing a camshaft journal at the end of the camshaft and supporting that part with a cam housing,
The camshaft does not have to have a particularly high strength, and the total length of the camshaft does not become larger than that of the conventional one.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a front view of the camshaft journal in FIG. 2 as viewed from the right side.

FIG. 4 is a sectional view showing a conventional structure corresponding to FIG.

[Explanation of symbols]

 1 Cylinder Head 2 Cylinder Head Cover 5 Valve 9 Cam Housing 10 Cam Shaft 11 Cam Shaft Journal 12 Cam 16 Coupling 17 Shaft 18 Fuel Pump 20 Cam Shaft Journal 21 Recessed Groove 22 Cam Housing

Claims (1)

[Claims] 1. A camshaft journal is provided at an end of a camshaft, the outer periphery of the camshaft journal is supported by a cam housing, and a groove is formed at an end of the camshaft journal to form a rotary shaft of an auxiliary machine. An auxiliary machine drive device for an internal combustion engine, characterized in that a shaft of an attached coupling is inserted and coupled.