JP7256974B2 - Mobile object detection device - Google Patents

Description

The present invention relates to a moving body detection device.

2. Description of the Related Art A moving body detection device is used to detect the movement of a moving body that moves linearly or rotationally. For example, in the fixing structure of the moving body detection device disclosed in Patent Document 1, a detection unit including a magnetic detection element, a magnet that applies a magnetic field to the magnetic detection element, and a substrate connected to the magnetic detection element is attached to a sensor main body. , the detection part is covered with a cover connected to the main body of the sensor, and fixed to the device through the cover, so as to detect changes in the magnetic field caused by the movement of the moving body.

Japanese Patent Application Laid-Open No. 2006-208023

In the fixing structure of the moving body detection device disclosed in Patent Document 1, the magnetic detection element and the like may be displaced within the cover due to vibration of the device, etc., resulting in a decrease in detection accuracy.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a moving body detection apparatus that alleviates the effects of vibrations that cause deterioration in detection accuracy and that has a high vibration reduction effect.

In order to achieve the above object, the moving body detection device of the present invention includes: a magnetic detection element that outputs an electric signal according to the movement of a detection target; a magnet that applies a magnetic field to the magnetic detection element; a housing arranged to face an object to be detected, wherein the housing has a cylindrical portion that covers the magnetic detection element and the magnet, and the cylindrical portion has reinforcing ribs on an outer circumference thereof in a circumferential direction. A plurality of ribs are integrally formed at equal intervals, and an O-ring groove is formed in the rear of the rib, and an O-ring is mounted thereon.

Advantageous Effects of Invention According to the present invention, it is possible to provide a moving body detection device that mitigates the effects of vibrations that cause deterioration in detection accuracy and that has a high vibration reduction effect.

1 is a schematic perspective view of an exploded state according to an embodiment of a moving body detection device of the present invention; FIG. 1 is a schematic perspective view according to one embodiment of the present invention; FIG. 1 is a schematic cross-sectional view according to one embodiment of the present invention; FIG.

Hereinafter, a moving body detection device according to a mode for carrying out the present invention will be described with reference to the drawings. In the following description, the front-rear direction is the X direction, the left-right direction is the Y direction, and the up-down direction is the Z direction, based on the state of the moving object detection device 100 shown in FIG. Also, the direction in which the arrows indicating the X direction, Y direction, and Z direction point is the + (plus) direction, and the opposite direction is the - (minus) direction. A moving body detection apparatus 100 of the present invention includes a magnetic detection element 10 that outputs an electric signal according to the movement of a detection target, a magnet 20 that applies a magnetic field to the magnetic detection element 10, and the detection target positioned in front. The housing 50 has a cylindrical portion 51 that covers the magnetic detecting element 10 and the magnet 20, and the cylindrical portion 51 has reinforcing ribs 51a on its outer periphery in the circumferential direction. A plurality of ribs 51a are integrally formed at intervals, and an O-ring groove 51b is formed behind the rib 51a, and an O-ring 53 is mounted thereon.

The moving body detection device 100 according to the present embodiment is configured as, for example, a rotation detection device provided near the axle of the front wheel of a two-wheeled vehicle, and measures the vehicle speed from the detected rotation speed of the front wheel. That is, in the moving object detection device 100, the axle of the front wheel is the object to be detected, the vehicle body in the vicinity of the axle is the fixed object 70, the fixed part 42 of the first housing 40 is fixed to the fixed object 70, and the first A second housing 50 that is fitted and connected to the housing 40 is arranged to face the axle.

The magnetic detection element 10 is composed of a Hall IC or the like that senses changes in the magnetic field that accompany the movement of a moving object, which is an object to be detected. The magnetic detecting element 10 is provided with a terminal 10b protruding rearward (-X direction) at a right angle from the upper end of the detecting portion 10a on the vertical plane (YZ plane) of the tip. The magnetic detection element 10 is housed in the housing portion 43 of the first housing 40 . The accommodating portion 43 is molded integrally with the first housing 40 and is molded to protrude forward (+X direction). The accommodating portion 43 is formed with a first concave portion 43a which is open at the center portion on the front side and is open upward (in the +Z direction). is accommodated, and the tip end face (the end face in the +X direction) of the detection part 10a is positioned in the opening in the center on the front side and arranged to face the object to be detected.

The magnet 20 is for applying a magnetic field to the magnetic detection element 10 . The magnet 20 is composed of, for example, a rectangular parallelepiped ferrite magnet. The magnet 20 is housed from below in a second recess 43b provided in the rear (-X direction) adjacent to the first recess 43a in which the magnetic detecting element 10 is housed and opened downward (-Z direction).

The lead terminal 30 is arranged parallel to the upper surface of a housing portion 43 that is integrally molded with the first housing 40, and is embedded in the first housing 40 and the housing portion 43 by insert molding. is connected to the terminal 10b of the magnetism detecting element 10 by soldering or the like, and the rear end 30a (see FIG. 3) protrudes into the connector 44 behind the first housing 40 as a connector pin for outputting the detection signal to the outside. can be derived from A substrate is provided between the front end of the lead terminal 30 and the terminal 10b of the magnetic detection element 10, and electronic parts such as an IC and a chip element for processing the detection signal of the magnetic detection element 10 are mounted. An output signal processing circuit is provided so that the output signal processed by the substrate processing circuit can be led out from the connector section 44 via the lead terminal 30, or the detection signal from the magnetic detection element 10 can be output. is output, it is processed by an external processing circuit.

As shown in FIG. 1, the first housing 40 is formed concentrically with a main body portion 41 having a substantially oval outer shape connecting two large and small circular arc portions, and a central portion of the small circular arc portion of the main body portion 41. A fixed portion 42, a housing portion 43 integrally formed by protruding forward (+X direction) from the central portion of the large arc portion of the main body portion 41, and a rearward (−X direction) protruding portion from the large arc portion of the main body portion 41. and a connector portion 44 integrally formed with the connector, and is made of synthetic resin such as polybutylene terephthalate (PBT) resin. Note that the two arc portions may have the same size.

The fixed portion 42 is made of metal and has a cylindrical collar 42 a , and is integrated with a downward projecting portion of the main body portion 41 of the first housing 40 . The fixed portion 42 is integrated with a small circular arc portion of the body portion 41 by insert-molding a metallic cylindrical collar 42a. As shown in FIG. 3, the first housing 40 can be fixed by inserting a fixing bolt into the collar 42a from the rear (-X direction) and tightening it to the fixing object 70. As shown in FIG. The body portion 41 has a side wall portion 41a defined by the inner edge portion of the large arc portion and the semicircular portion of the small arc portion side of the collar 42a. The rear (−X direction) side is closed with a flat plate-shaped bottom plate portion 41b which is a concave portion.

The accommodating portion 43 is integrally formed of synthetic resin in a substantially rectangular parallelepiped shape, protruding forward through a cylindrical portion 43c on the front side of the bottom plate portion 41b of the main body portion 41 . An O-ring groove is formed in the outer peripheral portion of the columnar portion 43c, and an O-ring 45 is mounted thereon to seal with a second housing 50 to be fitted and connected, which will be described later. As already described, the accommodation portion 43 is provided with the first recess 43a and the second recess 43b, and the magnetic detection element 10 is mounted in the first recess 43a and the magnet 20 is mounted in the second recess 43b. be done.

The connector portion 44 has a hollow rectangular tubular shape and is open at the rear (-X direction), and is formed integrally with the bottom plate portion 41b of the main body portion 41 so as to protrude rearward. (not shown)) can be connected in a predetermined direction, and the locking concave/convex portion can maintain the locked and connected state of the connectors.

The second housing 50 includes a bottomed cylindrical portion 51 that covers one side (front side (+X direction)) of the first housing 40 and is fitted and connected to face the object to be detected. 51 and a flange portion 52 formed integrally with the open end thereof. The second housing 50 is made of the same synthetic resin as the first housing 40, such as polybutylene terephthalate (PBT) resin. The second housing 50 (simply called a housing) has a cylindrical portion 51 functioning as a cover for covering the magnetic detecting element 10 and the magnet 20 housed in a housing portion 43 formed integrally with the first housing 40 . A plurality of reinforcing ribs 51a are integrally formed on the outer periphery of the cylindrical portion 51 at equal intervals in the circumferential direction. The ribs 51 a increase the rigidity and reduce the influence of vibrations from the fixed object 70 . Further, the rib 51 a has a function of guiding when attaching the O-ring 53 and of guiding when attaching the moving object detection device 100 to the fixed object 70 . An O-ring groove 51b is formed in the rear portion of the rib 51a of the cylindrical portion 51, and an O-ring 53 is mounted thereon to seal with the fixed object 70. transmission to the housing 40 is suppressed. The flange portion 52 is formed in an outer shape that follows the inner shape of the side wall portion 41a of the first housing 40, closes the surrounding side wall portion 52a and the front opening of the side wall portion 52a, and is cylindrical. It is composed of a cover plate portion 52b integrally provided with the portion 51. As shown in FIG. As a result, the flange portion 52 of the second housing 50 is mounted inside the side wall portion 41 a of the first housing 40 by connecting the second housing 50 so as to cover the inside of the first housing 40 . The opening of the side wall portion 41a is closed by the cover plate portion 52b, and the flange portion 52 has the same thickness as the fixing portion 42 of the first housing 40. . That is, when the height of the side wall portion 41a of the main body portion 41 of the first housing 40 and the height of the side wall portion 52a of the flange portion 52 of the second housing 50 are in a fitting connection state, the cover plate portion 52b is It is set to have the same thickness as the fixed portion 42 of the first housing 40 . In addition, when the first housing 40 is fixedly installed on the fixed object 70 by the fixing part 42, the flange portion 52 of the second housing 50 is sandwiched between the first housing 40 and the fixed object 70, resulting in a moving object. The detection device 100 can be reliably held on the fixed target 70 .

A connection holding mechanism 60 is provided between the first housing 40 and the second housing 50 to hold the fitted connection state. Four engaging recesses 61 are formed as substantially rectangular holes in the side wall portion 41a of the first housing 40, which is the fixed side to be fixed to the object to be fixed 70. As shown in FIG. On the side wall 52a of the second housing 50 that is to be fitted and connected to the first housing 40, there is an engagement projection 62 having a hook that engages the engagement recess 61 from the inside to the outside. integrally formed. Accordingly, by attaching and connecting the side wall portion 52a of the second housing 50 to the inner side of the side wall portion 41a of the first housing 40, the hook of the engaging convex portion 62 of the second housing 50 is connected to the first housing. The fitting and connection state of the first housing 40 and the second housing 50 is held by the connection holding mechanism 60 by engaging with the hole of the engagement recess 61 of the housing 40 . The engagement recess 61 and the engagement protrusion 62 may be reversed by providing the engagement protrusion 62 on the first housing 40 and providing the engagement recess 61 on the second housing 50 . Furthermore, in this moving body detection device 100, when the first housing 40 is fixedly installed on the fixed object 70 via the fixing portion 42, the flange portion 52 of the second housing 50 fitted and connected to the first housing 40 is To ensure that the moving object detection device 100 is held by the fixed object 70 even if a problem arises in the fitting connection state of the connection holding mechanism 60 due to being sandwiched between the first housing 40 and the fixed object 70 . can be done.

As shown in FIG. 3, such a moving object detection device 100 includes a first housing 40 in which an O-ring 45 is attached to a columnar portion 43c, and a magnetic detecting element 10 and a magnet 20 are accommodated in an accommodating portion 43. are fitted and connected so as to cover the housing 50, and the engaging concave portion 61 and the engaging convex portion 62 of the connection holding mechanism 60 are engaged to maintain the connected state. Also, the O-ring 53 is attached to the O-ring groove 51b of the second housing 50. As shown in FIG. Next, the second housing 50 is attached to the mounting hole 71 formed in the fixed object 70 facing the object to be detected (not shown), and the collar 42a of the fixed portion 42 of the first housing 40 is mounted. The mounting bolt inserted in is tightened to the fixed object 70 to fix it. A connector for attachment is connected to the connector portion 44 from the outside so that a detection signal can be output to the outside. As a result, the moving object detection device 100 is fixed to the fixed object 70 by the mounting bolts, and the object to be detected and the magnetic detection element 10 face each other. is detected (measured) by For example, when the moving object detection device 100 is a rotation detection device, the axle of the front wheel of a two-wheeled vehicle is the object to be detected, the vehicle body in the vicinity of the axle is the object to be fixed 70 , and the object to be fixed 70 is the first housing 40 . By fixing the fixing portion 42 , the tip of the second housing 50 fitted and connected to the first housing 40 is arranged in the mounting hole 71 so as to face the axle. As a result, the number of rotations of the axle is measured from the magnetic change caused by the rotation of the axle of the two-wheeled vehicle, which is the object to be detected, and the vehicle speed is calculated and output to the outside, or the number of rotations of the axle is detected and output. be done.

As specifically described above together with the embodiments, according to the moving object detection device 100 of the present invention, the magnetic detection element 10 that outputs an electric signal corresponding to the movement of the object to be detected, and the magnetic detection element 10 a magnet 20 that applies a magnetic field to the body, and a housing 50 that is arranged facing the object to be detected located in front, the housing 50 having a cylindrical portion 51 that covers the magnetic detection element 10 and the magnet 20, A plurality of ribs 51a for reinforcement are integrally formed on the outer circumference of the cylindrical portion 51 at equal intervals in the circumferential direction, and an O-ring groove 51b is formed behind the ribs 51a, and an O-ring 53 is mounted thereon. In the moving object detection device 100 , the housing 50 has ribs 51 a of the cylindrical portion 51 to increase rigidity and reduce the influence of vibration from the fixed object 70 . Further, since the housing 50 is attached to the mounting hole 71 of the fixed object 70 via the O-ring 53 attached to the outer periphery of the O-ring groove 51b, the vibration from the fixed object 70 can be reduced by the O-ring 53. It is possible to expect a vibration reduction effect. As a result, the moving object detection device 100 can alleviate the influence of vibrations that cause a decrease in detection accuracy, and can provide a moving object detection device that is highly effective in reducing vibrations.

In the above-described embodiment, the mobile object detection device 100 is used as a rotation detection device to detect an object rotating in motion. can be Further, the magnetic detecting element 10 has been described as an example in which it is configured by a Hall IC, but it is not limited to this and may be of any other type. Further, the materials of the first housing 40, the second housing 50, etc. are not particularly limited, and commonly used synthetic resins and the like can be used. Also, the X, Y, and Z directions in the moving body detection device 100 are set for explanation, and the mounting direction of the moving body detection device 100 is not limited to these directions. Moreover, the present invention is not limited to the above embodiments.

100 moving body detection device 10 magnetic detection element 10a detection portion 10b terminal 20 magnet 30 lead terminal 30a terminal 40 first housing 41 main body portion 41a side wall portion 41b bottom plate portion 42 fixing portion 42a collar 43 housing portion 43a first concave portion 43b second second Recessed portion 43c Cylindrical portion 44 Connector portion 45 O-ring 50 Second housing (housing) 51 Cylindrical portion 51a Rib 51b O-ring groove 52 Flange portion 52a Side wall portion 52b Cover plate portion 53 O-ring 60 Connection holding mechanism 61 Engaging recessed portion 62 Engagement Joint protrusion 70 Fixed object 71 Mounting hole

Claims (1)

a magnetic detection element that outputs an electric signal according to the movement of an object to be detected ; a magnet that applies a magnetic field to the magnetic detection element; The housing has a cylindrical portion that covers the magnetic detecting element and the magnet, and the cylindrical portion has a plurality of reinforcing ribs integrally formed on the outer circumference thereof at equal intervals in the circumferential direction. , an O-ring groove is formed, and an O-ring is mounted .

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