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EP-4737944-A1 - RANGING DEVICE

EP4737944A1EP 4737944 A1EP4737944 A1EP 4737944A1EP-4737944-A1

Abstract

A ranging device (1) is configured to measure a distance to an object by scanning an outside with light and detecting the light reflected by the object. The ranging device includes a mirror (18), an oscillating shaft (13), and an actuator (20). The mirror is configured to oscillate to scan the outside with the light. The mirror is fixed to the oscillating shaft. The actuator includes a rotor magnet (22) and a rotor fixing portion (31, 37, 41, 46, 48). The rotor magnet has a tubular shape and the oscillating shaft is inserted through the rotor magnet. The rotor fixing portion fixes the rotor magnet to the oscillating shaft. The actuator is configured to drive the oscillating shaft to oscillate by being energized. The rotor fixing portion restricts the rotor magnet from moving in an axial direction, a radial direction, and a rotational direction of the oscillating shaft.

Inventors

  • IMAI, TSUYOSHI
  • OKADA, KEITA
  • TOMITA, SHODAI

Assignees

  • DENSO CORPORATION

Dates

Publication Date
20260506
Application Date
20240613

Claims (8)

  1. A ranging device configured to measure a distance to an object by scanning an outside with light and detecting the light reflected from the object, the ranging device comprising: a mirror (18) configured to oscillate to scan the outside with the light; an oscillating shaft (13) to which the mirror is fixed; and an actuator (20) configured to drive the oscillating shaft to oscillate by being energized, wherein the actuator includes: a rotor magnet (22) having a tubular shape, the rotor magnet through which the oscillating shaft is inserted; and a rotor fixing portion (31, 37, 41, 46, 48) fixing the rotor magnet to the oscillating shaft, and the rotor fixing portion restricts the rotor magnet from moving in an axial direction, a radial direction, and a rotational direction of the oscillating shaft.
  2. The ranging device according to claim 1, wherein the rotor fixing portion includes a retaining plate (32, 38) fixed to the oscillating shaft, the rotor magnet has an end surface in the axial direction, and the end surface of the rotor magnet is fixed to the retaining plate by an interposed member (33).
  3. The ranging device according to claim 2, wherein the retaining plate has an adhesive surface (385) that faces the rotor magnet, and a magnet contact portion (381) that protrudes from the adhesive surface, and the magnet contact portion is in contact with the rotor magnet without the interposed member.
  4. The ranging device according to claim 3, wherein the adhesive surface defines a groove (382).
  5. The ranging device according to claim 1, wherein the rotor magnet has an end surface in the axial direction which defines a fitting groove (222, 223, 224), the rotor fixing portion (41, 46, 48) includes a retaining plate (42, 47, 49) having: a base portion (421) fixed to the oscillating shaft; and a protruding portion (422, 423, 492) protruding from the base portion, and the protruding portion of the retaining plate is fitted into the fitting groove of the rotor magnet.
  6. The ranging device according to claim 5, wherein the protruding portion is one of a plurality of protruding portions (422) and the fitting groove is one of a plurality of fitting grooves (222), and each of the plurality of protruding portions and each of the plurality of fitting grooves extends linearly and radially outward of the oscillating shaft.
  7. The ranging device according to claim 5, wherein the protruding portion (423, 492) is formed in a columnar shape.
  8. The ranging device according to any one of claims 2 to 7, wherein the rotor fixing portion includes an elastic member (35, 44), and the rotor magnet is disposed between the retaining plate and the elastic member.

Description

CROSS REFERENCE TO RELATED APPLICATION This application is based on Japanese Patent Application No. 2023-107966, filed on June 30, 2023. The entire disclosure of which is incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to a ranging device. BACKGROUND ART Ranging devices are known that detect the distance to an object by emitting a transmission wave and detecting a reflected wave of the transmission wave from the object. For example, a rotary reciprocating drive actuator disclosed in Patent Document 1 is used in a LiDAR (Light Detection and Ranging) device and is reciprocated by magnetic flux generated by a magnet fixed to a rotary shaft. PRIOR ART LITERATURE PATENT LITERATURE Patent Document 1: JP 2023-043027 A SUMMARY OF INVENTION In patent document 1, movement of the rotary shaft and the magnet in a thrust direction is restricted by a spacer and a preload spring. However, movement in a rotational direction or a radial direction is not restricted. An object of the present disclosure is to provide a ranging device capable of restricting a movement of a rotor magnet. The ranging device of the present disclosure is a device configured to measure a distance to an object by scanning an outside with light and detecting the light reflected by the object. The ranging device includes a mirror, an oscillating shaft, and an actuator. The mirror is configured to oscillate to scan the outside with the light. The mirror is fixed to the oscillating shaft. The actuator includes a rotor magnet and a rotor fixing portion. The rotor magnet has a tubular shape and the oscillating shaft is inserted through the rotor magnet. The rotor fixing portion fixes the rotor magnet to the oscillating shaft. The actuator is configured to drive the oscillating shaft to oscillate by being energized. The rotor fixing portion restricts the rotor magnet from moving in an axial direction, a radial direction, and a rotational direction of the oscillating shaft. As a result, the movement of the rotor magnet can be properly restricted. BRIEF DESCRIPTION OF DRAWINGS The above and other objectives, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the drawings, FIG. 1 is a schematic diagram showing a ranging device according to a first embodiment,FIG. 2 is a cross-sectional view showing an oscillating actuator of the ranging device according to the first embodiment,FIG. 3 is a cross-sectional view showing a rotor fixing portion according to the first embodiment,FIG. 4 is a cross-sectional view showing the rotor fixing portion according to a second embodiment,FIG. 5 is a cross-sectional view showing the rotor fixing portion according to a third embodiment,FIG. 6 is a cross-sectional view taken along a line VI-VI of FIG. 5,FIG. 7 is a view in a VII direction of FIG. 6,FIG. 8 is a cross-sectional view showing the rotor fixing portion according to a fourth embodiment,FIG. 9 is a cross-sectional view showing a protruding portion and a groove according to a fifth embodiment, andFIG. 10 is a cross-sectional view showing the rotor fixing portion according to a sixth embodiment. EMBODIMENTS FOR CARRYING OUT THE INVENTION Hereinafter, a ranging device of the present disclosure will be described with reference to the drawings. Hereinafter, in a plurality of embodiments, substantially the same components are denoted by the same reference signs, and the description thereof is omitted. (First Embodiment) The first embodiment is shown in FIGS. 1 to 3. As shown in FIG. 1, a ranging device 1 is a LiDAR (Light Detection and Ranging) device configured to measure a distance to an object by emitting light and detecting the light reflected from the object that is irradiated with the light. The ranging device 1 may be mounted on a vehicle and is used to detect objects that present in front of the vehicle. The ranging device 1 includes a light emitting unit 91, a light receiving unit 92, and an oscillating actuator 5, all of which are accommodated in a housing 93. The light emitting unit 91 intermittently emits a light beam B. The emitted light beam B is reflected by a mirror 18 that is oscillated, and is emitted to the outside through an optical window 94. The light receiving unit 92 receives the light reflected from an object irradiated with the light beam B. The light detected by the light receiving unit 92 is converted into an electrical signal, which is used for calculating the distance to the object. As shown in FIG. 2, the oscillating actuator 5 includes a mirror unit 10, an oscillating motor 20, and an encoder 25. The mirror unit 10 includes a base 11, a spindle 13, a holder 17, and a mirror 18. The base 11 includes a mounting portion 111 and retaining walls 112 and 113. The mounting portion 111 and the retaining walls 112 and 113 are integrally formed with each other from metal or the like. The mounting portion 111 is a