JPH08296540A - Signal rotor - Google Patents

Abstract

PURPOSE: To provide structure without the dislocation of a crank angle position by providing a signal rotor fitted to a camshaft sprocket, with holes having inner peripheral parts positioned at the same place or outside of the inner peripheral parts of engaging holes. CONSTITUTION: A signal rotor 11 is provided with through holes 13 with the inner peripheral parts 14 larger than the inner peripheral parts 15 of engaging holes 8 for inserting a fixed tool 39, provided at a camshaft sprocket 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the shape of a signal rotor mounted on a camshaft sprocket of an engine.

[0002]

2. Description of the Related Art An example of a timing belt train of an OHC engine is shown in FIG. 3 and 4, reference numeral 30 is a crankshaft sprocket, 31 is a camshaft sprocket, 32 is a signal rotor, and 33 is a timing belt. The camshaft sprocket 31 is fixed to the front end portion of the camshaft by a mounting bolt 34, and is wound by the crankshaft sprocket 30 and the timing belt 33. Further, the tensioner pulley 35 is in contact with the timing belt 33 from the outside. The number of teeth on the camshaft sprocket 31 is set to twice the number of teeth on the crankshaft sprocket 30. With such a configuration, the rotation of the crankshaft sprocket 30 is transmitted to the camshaft sprocket 31 via the timing belt 33 so that the camshaft sprocket 31 rotates once while the crankshaft sprocket 30 rotates twice.

As a result, since the crankshaft rotation angle can be detected from the rotation state of the crankshaft sprocket 30 or the camshaft sprocket 31, the prior art is disclosed in Japanese Patent Laid-Open No. 60-256009. The signal rotor is sandwiched between the camshaft and the camshaft sprocket, or the signal rotor 32 is attached to the camshaft sprocket 31 as shown in FIG. 4 to generate a crank angle signal. That is, to explain with the example of FIG. 4, a signal rotor 32 made of sheet metal is attached to the camshaft sprocket 31 so as to be superposed on it by a plurality of bolts 37 at predetermined positions via positioning pins 36. Further, the signal rotor 32 is provided with a plurality of projections 38 for generating a crank angle signal on the outer peripheral portion thereof, and a magnetic detection type sensor for crank angle detection (illustrated in the figure) provided on the fixed side of the engine. (No)) is detected and the crank angle signal is extracted by detecting the fluctuation of the magnetism generated as it passes near.

On the other hand, when the camshaft sprocket 31 to which the signal rotor 32 is attached is attached to the camshaft, as shown in FIG. 5, the fixed tool 39 is engaged with the engagement hole 40 to hold it in the immovable state and fastened. Ingredient 4
The mounting bolt 34 was tightened with 1. The fixed tool 39 has two pins that are inserted into the engagement holes 40 by pointing to the center of the camshaft sprocket 31, and are supported by the crotch part. Are formed.

[0005]

However, since the hole 42 formed in the overlapping surface of the signal rotor 32 is formed smaller than the engaging hole 40, the mounting bolt 3
When tightening 4, the inserted fixing tool 39 may directly contact the inner circumference of the hole 42 of the signal rotor 32, and the reaction force of the tightening load may act on it to cause the signal rotor 32 to be displaced. There is a problem that the installation position of the signal rotor 32 with respect to the sprocket 31 is deviated and an error occurs in the generation timing of the crank angle signal, which adversely affects the control of the engine.

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, in a signal rotor mounted in a superposed manner on a camshaft sprocket fixed to an end of a camshaft of an engine, the camshaft sprocket is provided with an engaging hole for inserting a tool. The signal rotor is provided with a hole having an inner peripheral portion that is the same as or outside the inner peripheral portion that abuts the tool engaged with the signal rotor.

[0007]

In the signal rotor mounted on the camshaft sprocket so as to be superposed on the camshaft sprocket, a hole having an inner peripheral portion that is the same as the inner peripheral portion of the engaging hole provided on the camshaft sprocket or is located outside of the inner peripheral portion is formed. Since it is provided on the signal rotor, when the fixed tool is inserted and held in the engagement hole and the camshaft sprocket is tightened to the camshaft, the fixed tool contacts the inner peripheral portion of the engagement hole and rotates in the tightening direction. Stop the. Further, since the inner peripheral portion acts so as to receive the restraining load, the action of the load on the signal rotor is prevented, and the displacement of the signal rotor with respect to the camshaft sprocket in the circumferential direction is prevented.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is A of FIG.
It is sectional drawing which follows the -A line. Since the embodiments of the present invention are substantially the same in construction as the above-mentioned conventional ones, the same reference numerals are given to those having the same construction, and different portions will be described. In FIGS. 1 and 2, a camshaft sprocket 3 constituting a timing belt train of the OHC engine of this embodiment is fixed to a camshaft 2 installed on a cylinder head 1. This camshaft sprocket 3 has an insertion hole 4 at the center for inserting the camshaft 2, and a fitting hole 6 for a knock pin 5 is provided close to the insertion hole 4.
Is provided. Also, camshaft sprocket 3
A boss 7 into which a center hole 12 of a signal rotor 11 described later is fitted is formed on the outer peripheral side of the insertion hole 4 on the back surface of the. Further, in the rib portion of the camshaft sprocket 3, six engaging holes 8 into which the fixing tool 39 is inserted are provided at concentric circles at equal intervals in the rib portion of the camshaft sprocket 3, and bolts 16 for attaching the signal rotor 11 to the rib portion therebetween are provided. 3 female screws 9 for fastening and the positioning pin 1 that determines the mounting position
0 is provided.

The signal rotor 11 is formed in a flat-bottom plate shape made of sheet metal, and the bottom portion is formed so as to be closely attached to the back surface of the camshaft sprocket 3. A central hole 12 that fits into the boss 7 of the camshaft sprocket 3 is formed in the center of the bottom portion, and six insertion holes 13 into which the fixing tool 39 can be inserted are formed in the rib portion.
Is provided at a position matching the engagement hole 8 of the camshaft sprocket 3, and the inner peripheral portion 14 of the insertion hole 13 is located outside the inner peripheral portion 15 of the engagement hole 8, that is,
It is formed larger than the engagement hole 8. Then, the insertion holes 17 of the three bolts 16 and the pin holes 18 are formed in the rib portion.
Is a female screw 9 provided on the camshaft sprocket 3,
And, it is provided so as to match with each of the positioning pins 10. Further, a plurality of protrusions 19 are arranged on the outer peripheral portion of the signal rotor 11.

The signal rotor 1 formed as described above
1 is superposed on the back surface of the camshaft sprocket 3, the pin hole 18 is fitted into the positioning pin 10, and the bolt 1 is fixed at a predetermined crank angle position of the camshaft sprocket 3. Thereby, the shaft center between the camshaft sprocket 3 and the signal rotor 11 and the phase in the circumferential direction are matched.

When the camshaft sprocket 3 thus superposed is fitted to the boss portion of the front end portion of the camshaft 2 with the knock pin 5 fitted and tightened with the mounting bolt 20, the camshaft 2 and the camshaft sprocket 3 are separated from each other. The camshaft sprocket 3 is configured to match the axial center and the phase in the circumferential direction, and the stationary tool 39 is inserted into the engagement hole 8 so that the camshaft sprocket 3 does not rotate together with the tightening of the mounting bolt 20. When tightening with the fastener 41 while holding the fixing tool 39,
It is configured to contact the inner peripheral portion 15 of the. With the above configuration, even when the camshaft sprocket 3 is fastened to the camshaft 2, the axial center between the signal rotor 11 and the camshaft 2 and the phase in the circumferential direction are not shifted, and a predetermined crank An angular position crank angle signal can be generated.

[0012]

According to the above construction, when the camshaft sprocket having the signal rotor attached thereto is fastened to the camshaft, the fixed tool is inserted into the engagement hole and provided to the signal rotor when a tightening load is applied. Since the inner peripheral part of the insertion hole of the fixed tool located outside is located outside the inner peripheral part of the engagement hole formed in the camshaft sprocket, the fixed tool abuts on this inner peripheral part, and the tightening load counteracts. It is possible to receive the force, there is no problem that the load is applied only to the signal rotor, and it is possible to prevent the displacement of the signal rotor in the circumferential direction with respect to the camshaft sprocket. As a result, it is possible to prevent an error from occurring in the generation timing of the crank angle signal generated by the signal rotor, and to obtain the effect of improving the accuracy of engine control.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an explanatory diagram of a timing belt train according to a conventional example.

FIG. 4 is a front view of a conventional example.

FIG. 5 is an explanatory view of a camshaft sprocket mounting operation.

[Explanation of symbols]

 2 camshaft 3 camshaft sprocket 8 engaging hole 11 signal rotor 13 hole (insertion hole) 14 inner peripheral part (signal rotor) 15 inner peripheral part (camshaft sprocket)

Claims (1)

[Claims] 1. A signal rotor mounted on a camshaft sprocket fixed to an end of a camshaft of an engine in an overlapping manner, wherein a camshaft sprocket is provided with an engaging hole for inserting a tool. A signal rotor characterized in that the signal rotor is provided with a hole having an inner peripheral portion that is the same as the outer peripheral portion that abuts against the tool or that is located outside thereof.