JPH0228458Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation direction detection sensor that detects the rotation direction of a rotating body.

Conventionally, this type of detection sensor has been provided with gear-like teeth on a rotating part that rotates following the rotating body, and two electromagnetic pickups are provided at a predetermined interval in the rotational direction of the teeth. It is common to have a configuration in which the rotation direction of the rotating body is detected by separating the phase difference between the output pulses of the two electromagnetic pickups generated by the rotation of the teeth using a phase discrimination circuit.

However, the above configuration has a problem in that the configuration of the phase discrimination circuit is complicated and the manufacturing cost is high.

The present invention has been made in view of the above circumstances, and its purpose is to provide a rotational direction detection sensor that can simplify the configuration and reduce manufacturing costs.

A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. 1 and 2 are first and second detection bodies facing each other with a predetermined interval,
Both of them are formed in the shape of a disk with the same diameter from a magnetic material, and the first detection body 1 is fixed to a rotating body (not shown) via a first rotating shaft 3 protruding from the center of the right side surface. The second detection body 2 is rotatably supported by a frame (not shown) via a second rotation shaft 4 protruding from the center of the left side surface. Reference numeral 5 denotes a first cylindrical body made of a non-magnetic material such as plastic that protrudes from the center of the left side of the first detection body 1, and a protrusion 6 having a predetermined width dimension is integrally formed at the tip of this cylindrical body. It has been extended. 7 is a second sensor made of non-magnetic material such as plastic that protrudes from the center of the right side of the second detection object 2.
This is a cylindrical body having the same diameter as the first cylindrical body 5, and a recess 8 having a width larger than the convex part 6 is formed at the tip, and the recess 8 has the same diameter as the first cylindrical body 5. The convex portion 6 of the first cylindrical body 5 is loosely fitted. The second detecting body 2 is mechanically linked to the first detecting body 1 by these concave portions 8 and convex portions 6, so that the rotary body and thus the first detecting body 1 rotate in one direction. When rotating in the direction indicated by arrow A in FIG. 1, one side of the convex portion 6 abuts one side of the concave portion 8 in a first state and follows the rotation, and the rotating body rotates in the other direction, that is, in a second state. A second state in which the other side of the convex portion 6 abuts the other side of the concave portion 8 when rotating in the direction shown by arrow B in the figure, that is, a predetermined angle with respect to the first detection object 1 compared to the first state. It exhibits a rotated state and follows the rotation. Reference numerals 9 and 10 denote first and second rod-shaped parts made of magnetic material that protrude from the side surfaces of the first and second detection bodies 1 and 2, respectively, and these rod-shaped parts 9 and 10 are shown in FIG. In the first state, the tips thereof face each other and are close to each other, and in the second state shown in FIG. It consists of 12 is a substantially U-shaped magnet that generates magnetic flux as a detection medium, and its S pole 1
3 and N pole 14 are the first and second detection bodies 1, respectively.
It is located close to and opposite to the circumferential side of No. 2. Reference numeral 15 denotes a normally open type reed switch serving as a magnetic detection means provided close to the peripheral side of the first and second detecting bodies 1 and 2 on the opposite side of the magnet 12. is detected.

Next, the operation of the above configuration will be explained. Now, the rotating body (not shown) rotates in one direction, that is, arrow A in FIG.
When it rotates in the direction shown, the first detection body 1 rotates integrally with this rotating body, and the second detection body 2 exhibits the first state with respect to the first detection body 1. Follow rotation. In such a first state, the tips of the first and second rod-shaped parts 9 and 10 made of magnetic material are in a state where they face each other and are close to each other. 1st and 2nd
The detection bodies 1 and 2 are magnetically short-circuited to each other, and the N pole 14 of the magnet 12 → the second detection body 2 →
A magnetic circuit is formed from the second rod-shaped portion 10 to the first rod-shaped portion 9 to the first detection body 1 to the S pole 13 of the magnet 12. When such a magnetic circuit is formed, the magnetic flux emitted from the magnet 12 is prevented as much as possible from leaking out from the magnetic circuit.
Since the magnetic flux from the reed switch 15 is prevented from reaching the reed switch 15, the reed switch 15 remains in the OFF state, and based on the OFF state of the reed switch 15, the rotation direction of the rotating body is detected as unidirectional rotation. be done.

However, when the rotating body rotates in the other direction, that is, in the direction indicated by arrow B in FIG. 2, the second detecting body 2 assumes a second state and rotates to follow the first detecting body 1. In such a second state, the first and second
Since the tips of the rod-shaped parts 9 and 10 are separated from each other and are in a non-opposing state, the magnetic flux emitted from the magnet 12 cannot pass through both the rod-shaped parts 9 and 10, so that both the first and second detection bodies 1 and 2 becomes magnetically open, and instead, the N pole 14 of the magnet 12 → the second detection object 2 → the reed switch 15 → the first detection object 1
→It passes through the magnetic circuit leading to the S pole 13 of the magnet 12. That is, the magnetic flux emitted from the magnet 12 reaches the reed switch 15 via the first and second detection bodies 1 and 2, and when the magnetic flux passes through the reed switch 15 in this way, the reed switch 15 This ON operation causes the rotating direction of the rotating body to be detected as rotation in the other direction.

According to the above configuration, the direction of rotation of the rotating body can be identified by the ON or OFF operation of the reed switch 15. There is no need to provide a phase discrimination circuit, the structure is simple, and manufacturing costs can be reduced.

FIG. 3 shows a second embodiment of the present invention, in which the same parts as those in the first embodiment are given the same reference numerals and explanations will be omitted, and only the different parts will be explained.
That is, in the first embodiment, the magnetic path opening/closing means 11 was composed of the first and second rod-shaped parts 9, 10, but in the third embodiment, the magnetic path opening/closing means 29 was composed of the first and second detecting bodies. It is composed of first and second engagement protrusions 30 and 31 made of a magnetic material and protruding from the side portions 1 and 2, respectively. These two engagement protrusions 30 and 31 are such that when the first detection body 1 rotates in one direction, that is, in the direction of arrow G, the tip side surface of the first engagement protrusion 30 becomes the second engagement protrusion 31. The second detecting body 2 comes into contact with the side surface of the distal end of the second detecting body 2, so that the second detecting body 2 assumes the first state and rotates to follow the first detecting body 1. 32 is a spacer made of a non-magnetic material located between the first and second detection bodies 1 and 2 and fixed to the side surface of the second detection body 2 by adhesive or the like; An engaging protrusion 33 is provided to protrude and oppose the protrusion 31 with a predetermined interval in the radial direction, so that when the first detection body 1 rotates in the other direction, that is, in the opposite direction of arrow G, The first engagement protrusion 30 contacts the end of the engagement protrusion 33 and is separated from the second engagement protrusion 31 as shown by the two-dot chain line, that is, rotates by a predetermined angle from the first state. In the displaced second state, the second detection object 2 is connected to the first detection object 1.
The rotation is made to follow.

In the second embodiment configured in this manner, when the rotating body (not shown) and the first detecting body 1 rotate in one direction, that is, in the direction of arrow G, the first and second engaging protrusions 30 and 31 are brought into contact with each other. The first and second detecting bodies 1 and 2 are in contact with each other and are magnetically short-circuited, and the N pole 14 of the magnet 12 → the second detecting body 2 → the second
A magnetic circuit is formed from the engaging protrusion 31 → the first engaging protrusion 30 → the first detection body 1 → the S pole 13 of the magnet 12, and the magnetic flux from the magnet 12 is transferred to the reed switch 1.
5 is prevented from reaching 5. On the other hand, when the rotating body rotates in the other direction, that is, in the opposite direction of arrow G, the first engagement protrusion 30 and the second engagement protrusion 31 become separated from each other, so that magnetic flux is emitted from the magnet 12. cannot pass through both the engaging protrusions 30, 31, and the space between the first and second detecting bodies 1, 2 becomes magnetically open, and instead, the N pole 14 of the magnet 12
→ second detecting body 2 → reed switch 15 → first detecting body 1 → it passes through a magnetic circuit leading to S pole 13 of magnet 12. Therefore, the same effects as in the first embodiment can be obtained in the second embodiment as well.

As is clear from the above description, the present invention includes a first detecting body provided on a rotating body whose rotational direction is to be detected, and a first detecting body provided mechanically linked to the first detecting body to detect the rotating body. When the rotating body rotates in one direction, it exhibits a first state with the first detecting body and rotates to follow it, and when the rotating body rotates in the other direction, it assumes a second state that is rotationally displaced by a predetermined angle from the first state. 1st
a second detection body that rotates to follow the detection body; a magnet that exerts magnetic flux of different polarity on both the first and second detection bodies; magnetic detecting means arranged so as to be interlinked through the body and whose output state changes depending on the magnetic flux; and magnetically short-circuiting between the first and second detecting bodies when in the first state. Preventing the magnetic flux from the magnet from reaching the magnetic detecting means, and magnetically opening the gap between both detecting bodies in the second state to allow the magnetic flux from the magnet to reach the magnetic detecting means. Since the structure is equipped with a magnetic path opening/closing means, the structure is simplified and the manufacturing cost can be reduced compared to the conventional structure consisting of two electromagnetic pickups and a phase discrimination circuit. A rotation direction detection sensor can be provided.

[Brief explanation of drawings]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a perspective view showing the state when rotating in one direction, and FIG. 2 is a perspective view showing the state when rotating in the other direction. 3 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention. In the figure, 1 and 2 are the first and second detection bodies, respectively;
5 is a first cylindrical body, 6 is a convex portion, 7 is a second cylindrical body, 8 is a concave portion, 9 and 10 are first and second bar-shaped portions, respectively, 11 is a magnetic path opening/closing means, and 12 is a concave portion. magnet, 15
29 is a magnetic path opening/closing means, 30 and 31 are first and second engaging convex portions, 32 is a spacer, and 33 is an engaging convex portion.

Claims (1)

[Scope of utility model registration request] A first device provided on the rotating body whose rotational direction is to be detected.
a detecting body, which is provided mechanically in conjunction with the first detecting body, and when the rotating body rotates in one direction, it assumes a first state with the first detecting body and rotates in accordance with the first detecting body, and the rotating body a second detection body that rotates to follow the first detection body in a second state rotated by a predetermined angle from the first state when the body rotates in the other direction; and both the first and second detection bodies a magnet that exerts magnetic flux of different polarity to each other, and a magnetic detection means arranged so that the magnetic flux from the magnet can be interlinked via both the first and second detecting bodies, and whose output state changes depending on the magnetic flux. , when in the first state, the first
and a second magnetically short-circuiting between both detecting bodies to prevent the magnetic flux from the magnet from reaching the magnetic detecting means, and magnetically opening between both detecting bodies when in the second state. A rotation direction detection sensor comprising: magnetic path opening/closing means for allowing magnetic flux from the magnet to reach the magnetic detection means.