JPH06288329A - Attaching construction of crank rotary angle sensor - Google Patents

Abstract

PURPOSE:To attach a rotational angle sensor easily without hanging circumference parts largely and detect the rotational angle accurately. CONSTITUTION:A signal rotor unit 3 is provided behind a crank shaft 1 within a crank case 9 and a rotational angle sensor 4 for detecting crank rotational angle by giving/receiving signals to/from the signal rotor unit 3 is fit on the back wall part 7 of a cylinder block 6. As the signal rotor unit 3 is mounted directly to the crank shaft 1, generation of rotational run-out is suppressed and an accurate rotational angle detecting signal can be obtained. As interference with circumference parts is prevented by inserting and fitting the rotational angle sensor 4 on the back wall part 7 of the cylinder block 6 as well as providing the signal rotor unit 3 behind the crank shaft 1, it is not necessary to change the circumference parts largely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank rotation angle sensor mounting structure used in an internal combustion engine.

[0002]

2. Description of the Related Art Recently, the rotation angle of an internal combustion engine may be detected for use in computer control. As a device for detecting a rotation pulse corresponding to a rotation angle from the crankshaft, a signal rotor portion 3 is provided around a crank pulley 2 or the like attached to the front portion of the crankshaft 1 as shown in FIG. Rotation angle sensor 4
And a device in which the ring gear of the flywheel 5 provided at the rear end of the crankshaft (not shown) is used as the signal rotor unit 3 and the rotation angle sensor 4 is installed on the circumference thereof.

[0003]

By the way, the rotation angle detection signal may be used for detecting misfire and the like. In this case, it is desired that the rotation angle detection signal has a particularly high accuracy. However,
In the above-described conventional technique, since the signal rotor unit 3 is provided on the crank pulley 2 or the flywheel 5, there is a risk of rattling at the time of rotation. When such rattling occurs, the accuracy of the rotation angle signal may decrease. there were. In addition, when mounting the rotation angle sensor 4, in many cases, a dedicated bracket is required, and there is a possibility that the peripheral parts may be significantly changed in shape in order to avoid interference with other parts.

The present invention has been made in view of the above circumstances, and a crank rotation angle sensor capable of easily mounting the rotation angle sensor without causing a significant change in surrounding parts and capable of detecting the rotation angle with high accuracy. The purpose is to provide a mounting structure.

[0005]

In order to achieve the above object, the present invention provides a signal rotor portion at the rear of a crankshaft in a crankcase and transmits / receives a signal to / from the signal rotor portion on a rear wall portion of a cylinder block. It is characterized in that a rotation angle sensor for detecting the crank rotation angle is inserted. In this case, a lightening portion is formed on the cylinder block side of a flywheel provided behind the crankshaft, and a rotation angle sensor is provided at the lightening portion.

[0006]

With this structure, since the signal rotor portion is directly provided on the crankshaft, the occurrence of rotational shake can be suppressed. Since the signal rotor portion is provided behind the crankshaft and the rotation angle sensor is fitted in the rear wall portion of the cylinder block, interference with surrounding parts can be suppressed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mounting structure for a crank rotation angle sensor according to an embodiment of the present invention will be described below with reference to FIGS.
In the figure, a flywheel 5 is attached to the crankshaft 1 so as to be positioned outside the rear wall portion 7 of the cylinder block 6. A lightening portion 8 is formed on a surface portion of the flywheel 5 on the cylinder block 6 side. A signal rotor portion 3 is integrally formed or press-fitted behind the crankshaft 1 in the crankcase 9, and a rotation pulse is generated when the crankshaft 1 rotates.

A through hole is formed in a portion of the rear wall portion 7 of the cylinder block 6 facing the lightening portion 8 of the flywheel 5.
10 are formed. A rotation angle sensor 4 that receives a rotation pulse from the signal rotor unit 3 to detect a rotation angle and transfers the rotation angle signal to a control unit (not shown) is fitted into the through hole 10. This rotation angle sensor 4 is a through hole
A screw (not shown) is screwed into a screw hole 11 provided in the vicinity of 10 to fix the screw.

In the mounting structure of the crank rotation angle sensor 4 configured as described above, since the signal rotor portion 3 is provided on the crankshaft 1 by integral processing or press fitting, it is possible to suppress the occurrence of rotational shake, and this is not necessary. An accurate rotation angle detection signal can be obtained. Further, since the rotation angle sensor 4 is directly attached to the cylinder block 6 without using a bracket or the like, the signal can be detected with higher accuracy.

Since the signal rotor portion 3 is provided behind the crankshaft 1 and the rotation angle sensor 4 is fitted in the rear wall portion 7 of the cylinder block 6, interference with surrounding components can be suppressed and the surrounding components can be changed significantly. Will not be invited.
Further, since the rotation angle sensor 4 is positioned and arranged in the space formed by the lightening portion 8, the rotation angle sensor 4
There is no need to take measures such as increasing the total length of the engine by installing the.

Further, since the bolt is screwed into the screw hole 11 provided in the cylinder block 6 to mount the rotation angle sensor 4, it is not necessary to separately prepare a dedicated bracket. Therefore, the number of parts can be reduced.

[0012]

As described above, according to the present invention, since the signal rotor portion is directly provided on the crankshaft, it is possible to suppress the occurrence of rotational shake and obtain a highly accurate rotational angle detection signal. Since the signal rotor portion is provided at the rear of the crankshaft and the rotation angle sensor is fitted in the rear wall portion of the cylinder block to prevent interference with surrounding components, the surrounding components are not significantly changed. Further, since the lightening portion is formed on the cylinder block side of the flywheel provided at the rear of the crankshaft, and the rotation angle sensor is provided at the lightening portion, the rotation angle sensor can be attached to extend the entire engine length. Can be achieved without

[Brief description of drawings]

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

FIG. 2 is a view showing a rear wall portion of a cylinder block of the embodiment.

FIG. 3 is an exploded perspective view showing an example of an arrangement state of a conventional rotation angle sensor.

FIG. 4 is an exploded perspective view showing another conventional example of an arrangement state of a rotation angle sensor.

[Explanation of symbols]

 1 Crankshaft 3 Signal rotor part 4 Rotation angle sensor 5 Flywheel 6 Cylinder block 7 Rear wall part 8 Thinned part 9 Crankcase

Claims (2)

[Claims] 1. A signal rotor portion is provided behind a crankshaft in a crankcase, and a rotation angle sensor for detecting a crank rotation angle by transmitting and receiving a signal to and from the signal rotor portion is fitted on a rear wall portion of a cylinder block. Characteristic crank rotation angle sensor mounting structure. 2. The attachment of a crank rotation angle sensor according to claim 1, wherein a cutout portion is formed on a cylinder block side of a flywheel provided behind the crankshaft, and a rotation angle sensor is provided at the cutout portion. Construction.