JP2010014607A - Rotational angle detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotational angle detection apparatus excellent in both assemblability and maintainability and provided with an input shaft structure in which the occurrent of abnormal noises is suppressed. <P>SOLUTION: The rotational angle detection apparatus includes: an input shaft 20 rotatably supported at a housing 10 via a bearing in such a way as to input rotational displacement to a rotational angle detection sensor 2 arranged in the housing; a rotation input member 30 fixed to a protrusion part 21 of the input shaft protruding from a tube end part 11 of the housing; and an elastic oil seal 40 for sealing a ring-like space between the input shaft and the tube end part. An extension part 44 of the oil seal on the side of the tube end part is interposed as an elastic member between the rotation input member and the tube end part with the sliding member 50 superposed in the shaft direction of the input shaft. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device including an input shaft rotatably supported by a housing via a bearing so as to input rotation displacement to a rotation angle detection sensor disposed in the housing.

  In the rotation angle detecting device of the type described above, the input shaft protrudes from the cylindrical end of the housing, and a rotating lever or swing that transmits the movement of the detection target object to the input shaft as a rotational displacement is projected to the protruding portion. A moving lever is provided as a rotation input member. In such a configuration, when displacement is transmitted from the rotary input member to the input shaft, an eccentric load is applied to the input shaft, and abnormal noise is generated due to the eccentric contact (twist) between the input shaft and the bearing. The problem arises. In order to suppress this eccentric contact, an elastic member is interposed between the rotary input member and the end of the housing to suppress the eccentric load from being applied to the input shaft, and between the input shaft and the bearing. It is conceivable to reduce the eccentric contact. However, in this configuration, when the rotary input member rotates together with the input shaft, a relative movement occurs with the elastic member that cannot rotate so smoothly, and this relative movement leads to abnormal noise. Cause serious problems.

In order to reduce relative movement between the rotating member and the holding member that holds the rotating member, a sandwich structure including a sliding member, a spacer, and a rubber plate is interposed between the rotating member and the holding member. A rotating device (ultrasonic motor) to be worn is known (see, for example, Patent Document 1). In this rotating device, smooth sliding is realized between the rotating member and the holding member by the sandwich structure. However, since this sandwich structure is disposed inside the housing, there is a problem that the assembling property and the maintenance property are poor.
JP-A-5-137357 (paragraph numbers 0011-0013, FIGS. 1 and 2)

  In view of the above situation, an object of the present invention is to provide a rotation angle detection device having an input shaft structure that is excellent in assembling property and maintainability and in which abnormal noise generation is suppressed.

  In order to achieve the above-mentioned object, the rotation detecting device according to the present invention includes a rotation angle detection sensor disposed in a housing, and a bearing in the housing so as to input rotational displacement to the rotation angle detection sensor. An input shaft rotatably supported via the input shaft, a rotation input member fixed to a protruding portion of the input shaft protruding from the cylindrical end portion of the housing, and an annular space between the input shaft and the cylindrical end portion An elastic oil seal for sealing the cylinder, and an extension of the oil seal on the cylinder end side as an elastic member together with a sliding member overlapped in the axial direction of the input shaft, the rotating input member and the cylinder end of the housing It is interposed between the parts.

  According to this characteristic configuration, the extension portion of the oil seal is interposed as an elastic member between the cylindrical end portion of the housing and the rotation input member fixed to the protruding portion of the input shaft protruding from the cylindrical end portion. Therefore, the swing of the rotary input member in the input shaft core direction is suppressed, and the eccentric load applied to the input shaft due to this swing is reduced. As a result, generation of abnormal noise due to eccentric contact between the input shaft and the bearing is also suppressed. Further, since the sliding member is interposed so as to overlap the extension portion in the axial direction of the input shaft, relative rotation between the sliding member and the member in contact with the sliding member is prevented. It is done smoothly. As a result, it is possible to suppress the occurrence of unsmooth slipping accompanied by generation of abnormal noise between the extension portion as the elastic member and the rotation input member or between the extension portion and the cylindrical end portion of the housing. Moreover, the member functioning as an elastic member is formed as an extension of the oil seal, and there is no problem of newly preparing an elastic member and increasing the number of parts. In addition, since both the extension portion and the sliding member as the elastic member are disposed outside the cylindrical end portion of the housing, the assembling property and maintenance property of these members are also good.

  Since the extension portion of the oil seal is effectively applied as an elastic member interposed between the rotation input member and the cylindrical end portion of the housing, in a further characteristic configuration of the present invention, the extension portion of the oil seal is It is formed in a ring collar shape that is bent and extended at right angles from the fitting portion with the inner surface of the cylindrical end portion, and the sliding member is sandwiched between the upper surface of the extension portion and the lower surface of the rotation input member. Yes. In this feature configuration, the extension portion of the ring collar shape that is bent at a right angle from the fitting portion of the oil seal that is firmly inserted into the inner surface of the cylindrical end portion of the housing as a mounting base is securely attached to the cylindrical end portion. Touch the end face. Thereby, this extension part can reliably fulfill the function of the extension part of the oil seal as an elastic member between the rotation input member and the cylindrical end part of the housing.

  Embodiments of a rotation angle detection device of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of the rotation angle detection device 1, and FIG. 2 is an axial cross-sectional view showing a part of the rotation angle detection device 1 in an enlarged view. The rotation angle detection device 1 includes a housing 10, a rotation angle detection sensor 2 disposed in the housing 10, and a bearing 3 inside the housing 10 so as to input rotational displacement to the rotation angle detection sensor 2. And an input shaft 20 that is rotatably supported. The input shaft 20 has a protruding portion 21 that passes through the cylindrical end portion 11 of the housing 10 and extends further outward. The protrusion 21 is formed with a screw. In order to transmit the displacement from the member to be detected to the input shaft 20, a rotation arm 30 as a rotation input member is fixed to the protruding portion 21 of the input shaft 20. The base 31 of the rotating arm 30 is provided with a rectangular hole that can be fitted into a rectangular base 22 provided at the stepped portion of the protrusion 21. The rotating arm 30 fitted into the rectangular base 22 is fixed to the step portion of the protruding portion 21 by being tightened by the nut 23.

  In this embodiment, the free end 32 of the rotating arm 30 is connected to a link mechanism for detecting the height of an automobile, which is not shown here. The displacement from the link mechanism is converted into the rotation angle displacement of the input shaft 20, and the vehicle height value is calculated based on the output signal of the rotation angle detection sensor 2. Therefore, the rotation angle detection device 1 in this embodiment is used as a vehicle height detection device.

  Further, in the rotation angle detection device 1, an elastic oil seal (hereinafter simply referred to as an oil seal) 40 is loaded in an annular space created by the tube end portion 11 of the housing 10 and the input shaft 20. As apparent from FIGS. 2 and 3, the oil seal 40 includes a dust lip 41, a seal lip 42, a fitting part 43, an extension 44, a spring 45, and a metal ring 46. Except for the extension 44, the elastic oil seal 40 has a normal oil seal structure. The spring 45 has a function of pressing the dust lip portion 41 and the seal lip portion 42 against the input shaft 20. The metal ring 46 functions as a core material of the fitting portion 43 and ensures that the fitting portion 43 is fitted into the inner surface of the tube end portion 11 of the housing 10. Except for the spring 45 and the metal ring 46, they are made of rubber.

  The extension 44 characterizing the oil seal 40 is bent at a right angle from the fitting portion 43 having a cylindrical shape and extends radially outward in a ring collar shape. Therefore, in a state where the oil seal 40 is loaded on the cylinder end 11 of the housing 10, the lower surface of the extension 44 contacts the end surface 11 a of the cylinder end 11. The length of the extension part 44 is set so that the end surface 11a of the tube end part 11 can be substantially covered. The extension portion 44 has a thickness between the end surface 11 a of the tube end portion 11 and the rotation arm 30 so that the extension portion 44 can function as an elastic member that suppresses application of an eccentric load to the input shaft 20 of the rotation arm 30. It is set to fill the gap. In this embodiment, a sliding member 50 formed as a thin ring plate is interposed between the extension portion 44 and the rotating arm 30 so as to overlap the surface of the extension portion 44.

  In the rotation angle detection device 1, the rotation of the rotating arm 30 in the axial direction of the input shaft 20 is suppressed by the extension 44 of the oil seal 40 that functions as an elastic member, and the input shaft 20, the bearing 3, Generation of abnormal noise due to eccentric contact between the two is suppressed. Further, the relative rotation between the elastic member 40 and the sliding member 50 is smoothly performed by the interposition of the sliding member 50, and the extension portion 44 and the rotating arm 30 or between the extension portion 44 and the housing 10. Generation of abnormal noise between the two is suppressed.

  In the rotation angle detection device 1 described above, the extension portion 44 of the oil seal 40 as an elastic member is in contact with the end surface 11a of the cylindrical end portion 11 of the housing 10 by loading the oil seal 40 as in the related art. Is positioned. Further, the sliding member 50 disposed so as to overlap the extension portion 44 is disposed outside the tube end portion 11 of the housing 10. Thereby, the assembly | attachment operation | work of the extension part 44 and the sliding member 50 as an elastic member becomes easy. Further, whether or not the sliding member 50 is mounted can be easily confirmed visually from the outside.

  As the rotation angle detection sensor, a rotation angle detection format using a Hall element and a magnet is preferable, but in the present invention, the format of the rotation angle detection sensor is not limited. In addition, the rotation angle detection device 1 can be applied not only to vehicle height detection but also to rotation angle detection in various fields.

1 is an exploded perspective view of a rotation angle detection device according to the present invention. Sectional drawing which expands and shows the housing cylinder edge part area of a rotation angle detector Side view of oil seal

Explanation of symbols

1: Rotation angle detection device 2: Rotation angle detection sensor 3: Bearing 10: Housing 11: Tube end 20: Input shaft 21: Projection 30: Rotating arm (rotation input member)
40: Oil seal (elastic oil seal)
44: Extension part 50: Sliding member

Claims (2)

  A rotation angle detection sensor disposed in the housing; an input shaft rotatably supported by the housing via a bearing so as to input rotational displacement to the rotation angle detection sensor; and a cylinder of the housing of the input shaft. A rotation input member fixed to a projecting portion protruding from the end portion, and an elastic oil seal that seals an annular space between the input shaft and the tube end portion, on the tube end side of the oil seal A rotation angle detection device in which an extension portion is interposed between the rotation input member and a cylindrical end portion of the housing together with a sliding member superimposed in the axial direction of the input shaft as an elastic member.   The extension portion of the oil seal is formed in a ring collar shape extending at a right angle from the fitting portion with the inner surface of the cylinder end portion, and the oil seal is formed between the upper surface of the extension portion and the lower surface of the rotary input member. The rotation angle detection device according to claim 1, wherein the sliding member is clamped.

Images