JPH0651810U - Position detector - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a position detection device that can be configured in a small size to increase the degree of freedom of mounting and to not affect the operation characteristics of the movable member. The purpose is to A magnet 13 mounted on a movable member 12, MI elements 14 and 15 arranged at positions corresponding to the magnet at a moving position to be detected by the movable member, and the MI element are operated. And a control circuit 1 for processing the signal from the MI element
The position detection device 10 is configured so as to include 6 and 17.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a position detecting device for detecting the moving position of a movable member such as an air cylinder or a hydraulic cylinder.

[0002]

[Prior art]

 Conventionally, such a position detecting device is configured as shown in FIG. That is, in FIG. 3, the position detecting device 1 includes a magnet 4 mounted on a piston 3 slidably arranged in the cylinder 2 in the direction of the arrow X, and an outer surface of the cylinder 2. The HIC module 5 is arranged at a position corresponding to the magnet 4 at the moving position of the piston 3 to be detected.

The HIC module 5 includes a magnetic sensor such as an MR element or a Hall element, and an amplifier that amplifies a signal from the magnetic sensor. As a result, when the piston 3 moves to the position to be detected, the magnet 4 mounted on the piston 3 approaches the magnetic sensor, so that the magnetic sensor detects the magnetism of the magnet 4 and outputs a signal. Is to occur.

According to the position detecting device 1 having such a configuration, when the piston 3 of the cylinder 2 moves to a predetermined position set in advance, the magnetic sensor of the HIC module 5 operates The magnetism of the magnet 4 of the piston 3 is detected to generate a signal. This signal is further amplified by the amplifier of the HIC module 5 and then sent to a processing circuit (not shown) or the like so that various controls can be performed.

[0005]

[Problems to be solved by the device]

 However, in the position detecting device 1 configured as described above, since the magnetic sensor of the HIC module 5 is an MR element, a Hall element or the like, its output signal is weak. Therefore, it is necessary to dispose a high-gain amplifier adjacent to the magnetic sensor, and the HIC module 5 as a whole becomes relatively large. However, there was a problem that the degree of freedom in mounting was reduced due to the restriction on mounting.

Further, the magnetic sensor has a relatively low sensitivity, and therefore a relatively large magnet is required as the magnet 4 to be mounted on the piston. Therefore, in the case of a small cylinder, the piston becomes large or heavy. This could affect the operating characteristics of the cylinder.

In view of the above points, the present invention provides a position detecting device that can be configured in a small size to increase the degree of freedom of mounting and not to affect the operation characteristics of the movable member. The purpose is to do.

[0008]

[Means for Solving the Problems]

 According to the present invention, the above object is to provide a magnet attached to a movable member and an amorphous magnetic inductance element (hereinafter, MI Element) and a control circuit for activating the MI element and processing a signal from the MI element.

[0009]

[Action]

 According to the above configuration, since the MI element is used as the magnetic sensor, the MI element has high sensitivity, so that the magnet mounted on the movable member can be downsized, and the size of the movable member can be reduced. Or the impact on operating characteristics can be reduced.

Further, since the MI element has a relatively large output signal, a control circuit such as an amplifier for amplifying the output signal can be separated from the MI element. Accordingly, since only the MI element needs to be disposed adjacent to the movable member, the degree of freedom in mounting the MI element becomes relatively high. Therefore, for example, when the position detecting device is attached to the cylinder, the mounting is not restricted by the diameter and size of the cylinder, the stroke of the piston, and the like.

[0011]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 shows an example of a position detecting device according to the present invention mounted on a cylinder. The position detecting device 10 is slidable in the cylinder 11 along the direction of arrow X. A small magnet 13 mounted on the piston 12, and a first MI element 14 disposed inside the cylinder 11 at positions corresponding to the two moving positions of the piston 12 to be detected. It is composed of a second MI element 15.

The first MI element 14 and the second MI element 15 are operated by the power supply control circuit 16 by applying an AC voltage of, for example, about 30 mA and 10 kHz, and the AC power supply A signal proportional to the external magnetic field superposed on, that is, the magnetic field generated by the magnet 13 is generated.

Output signals from the first MI element 14 and the second MI element 15 are respectively taken out by the power supply control circuit 16 and sent to the processing circuit 17. When the piston 12 moves to the left and the magnet 13 approaches the first MI element 14, the level of the output signal is inverted to L, and the processing circuit 17 moves the piston 12 to the right. Then, when the magnet 13 approaches the second MI element 15, the output is appropriately switched so that the level of the output signal is inverted to H.

The position detecting device 10 according to the present invention is configured as described above, and when the piston 12 moves to the left when moving in the cylinder 11, the piston 12 moves the piston 12 to the first position. When approaching the MI element 14, the output signal level of the processing circuit 17 is inverted to L so that the position of the piston 12 can be detected. When the piston 12 moves to the right inside the cylinder 11, when the piston 12 approaches the second MI element 15, the output signal level of the processing circuit 17 is inverted to H, The position of the piston 12 will be detected. Thus, the position of the piston 12 can be detected when the piston 12 approaches the first MI element 14 and the second MI element 15.

Further, the output signal of the processing circuit 17 is sent to an automatic control device (not shown) or the like so that automatic control including the cylinder 11 can be performed.

In this embodiment, since the two MI elements 14 and 15 are mounted inside the cylinder 11, the magnetic sensor portion does not project outside the cylinder 11, and accordingly, , Any position of the piston 12 can be easily detected.

FIG. 2 shows another embodiment of the position detecting device according to the present invention. In FIG. 2, the position detection device 20 includes a small magnet 23 mounted near the tip of a swing lever 22 rotatably supported around a shaft 21 and two swing levers 22 to be detected. It is composed of a first MI element 24 and a second MI element 25 which are respectively arranged at positions corresponding to the moving position.

The first MI element 24 and the second MI element 25 are operated by a circuit (not shown) similar to the power supply control circuit 16 and the processing circuit 17 in the embodiment of FIG. The signal is ready to be processed.

According to the position detecting device 20 having such a configuration, the movement of the swing lever 22 to the position to be detected or the position confirmation can be easily detected.

[0020]

As described above, according to the present invention, since it can be configured in a small size, the degree of freedom in mounting is increased and the operation characteristics of the movable member are not affected. Therefore, an excellent position detecting device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a state in which a position detecting device according to an embodiment of the present invention is incorporated in a cylinder.

FIG. 2 is a schematic diagram showing another example of use of the position detection device of FIG.

FIG. 3 is a schematic view showing an example of a conventional position detecting device in a cylinder.

[Explanation of symbols]

 10, 20 Position detection device 11 Cylinder 12 Piston 13,23 Magnet 14,24 First MI element 15,25 Second MI element 16 Power supply control circuit 17 Processing circuit 21 Axis 22 Swing lever

Claims (1)

[Scope of utility model registration request] 1. A magnet mounted on a movable member, an MI element disposed at a position corresponding to the magnet at a movement position of the movable member to be detected, and the MI element for operating and MI. A position detection device including a control circuit that processes a signal from the element.