JPH0431588Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a rotation speed detector for a rotating body.

(Prior Art) Conventionally, a method for detecting the rotational speed of a rotating body uses a magnetic or Detected by optical or other methods,
A method is known in which the rotational speed of a rotating body is determined from the phase difference between a pair of detection signals for the same detection point.
However, in the conventional method, the arrangement positions of the pair of detectors were fixed with respect to the center of rotation of the rotating body.

(Problems to be solved by the invention) Fig. 2 is a diagram showing a conventional example using a photodetection method, in which protrusions 1 ₂ are formed at predetermined intervals on the outer periphery of a rotating body 1, and the rotation thereof is Accompanied by a light-receiving element
Light from light emitting elements (not shown) disposed opposite P ₁ and P ₂ with the rotating body 1 interposed therebetween is intermittently blocked.
Therefore, the light receiving elements P ₁ and P ₂ are configured to be able to detect interruptions in light as the rotating body 1 rotates.

In this case, when the light-receiving elements P ₁ and P ₂ are fixedly arranged on arcs R ₁ and R ₂ that are different distances from the rotation center of the rotating body 1, the different points of the protrusion 1 ₂ of the rotating body 1 are Since the light passes through the light receiving elements P ₁ and P ₂ , unless the edge 1 ₃ of the protrusion 1 ₂ is on the ray from the center of rotation as shown by the dotted line, each light receiving element P ₁ and P ₂
It is not possible to accurately detect the rotational speed from the phase difference signal indicating the time difference between the passing times of the rotating body.

(Means for solving the problem) Detecting time information when a detection point provided on a rotating body whose rotational speed is to be detected passes between a pair of detectors placed at different positions, and using the time information to detect the rotation speed. In a rotational speed detector that detects the rotational speed of a body, the pair of detectors are held on the same plane substantially parallel to the rotational plane of the rotating body, and the pair of detectors are integrally held on the same plane. a holding member rotatably held about an axis perpendicular to the rotation plane to enable concentric movement; a biasing means for biasing the holding member in one rotational direction; It has a rotation regulating means which regulates the rotation of the holding member against the biasing force of the means and whose regulation position can be adjusted.

(Function) By adjusting and arranging a pair of detectors at equal distances from the rotation center of the rotating body, the phase difference signal can be accurately detected regardless of manufacturing variations in the detection points formed on the outer periphery of the rotating body. It is possible to detect rotational speed.

(Embodiment) FIG. 1 shows an embodiment of the present invention using optical detection.

Reference numeral 1 denotes a rotating body on which rotational speed is detected, and is configured to be rotatable around its center ₁₄ .
1 ₁ is the tooth profile formed on its outer periphery, as shown in Figure 1 b
A desired number of protrusions ₁₂ are formed at approximately equal intervals as shown in FIG. 2 is a light receiving substrate holding light receiving elements P ₁ and P ₂ at a predetermined distance; the light receiving elements P ₁ and P ₂ are arranged near the top of the toothed part 1 ₁ of the rotating body;
It is held by the block ₄ so as to be rotatable about the screw ₅₁ so that the distances from the rotation center 14 are approximately equal.

Reference numeral 6 denotes a coil spring which is compressed and held between the head of the screw ₅₁ and the light receiving board 2, and whose both ends are installed between the block 4 and the light receiving board 2. Apply rotational force counterclockwise around point ₁ .

The tip of ₅₃ contacts one side of the light receiving board 2, and is screwed into the block 4 with an adjustment screw that restricts its rotation.

Numeral 5 ₂ is a fixing screw for fixing the light receiving board 2 to the block 4 after the position of the light receiving board 2 has been adjusted with the adjusting screw 5 ₃ , and is engaged with a long hole 2 ₁ formed in the light receiving board 2 .

Reference numeral 3 denotes a light emitting substrate holding two light emitting elements (not _shown ) at _a predetermined distance. The distances between them are approximately equal, and the light receiving elements P ₁ and P ₂ are fixedly held at positions opposite to the light receiving elements P 1 and P 2 via the rotating body 1 .

Since it is configured as described above, the adjustment screw 5 ₃
By turning the light-receiving substrate 2 around the screw ₅₁ , the light-receiving elements _P1 and _P2 can be brought to the same distance from the rotation center ₁₄ of the rotating body 1.

In the embodiment, a photodetection method using tooth profile formation is shown, but the present invention is not limited to this, and it goes without saying that it can also be used in a magnetic detection method.

(Effect of the invention) According to the invention, the pair of detectors can be brought to the same distance from the center of the rotating body by adjusting the restriction position of the rotation restriction means. Furthermore, since these pair of detectors are integrally held by the holding member, when both detectors are arranged at the same distance by adjustment, the detection point of the rotating body moves between the two detectors. The distance when doing so is always constant.

Further, according to the present application, these effects can be achieved with a simple configuration, and furthermore, it is possible to easily arrange a pair of detectors in the vicinity.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG. 2 is a diagram for explaining a conventional example, in which 1...rotating body, 2...light receiving board, 3...light emitting board, 4...block, 5 ₃ ...adjustment screw, 6...
Coil spring, P ₁ , P ₂ ... light receiving element.

Claims (1)

[Claims for Utility Model Registration] Time information is detected when a detection point provided on a rotating body whose rotational speed is to be detected passes between a pair of detectors placed at different positions, and the detection point of the rotating body is detected based on the time information. In a rotation speed detector that detects rotation speed, the pair of detectors are held on the same plane substantially parallel to the rotation plane of the rotating body, and integral concentric circles of the pair of detectors are held on the same plane. a holding member rotatably held about an axis perpendicular to the plane of rotation to enable movement; a biasing means for biasing the holding member in one rotational direction; A rotational speed detector comprising a rotation regulating means which regulates the rotation of the holding member against an urging force and whose regulation position can be adjusted.