JPH0718269U - Servo acceleration sensor - Google Patents

Abstract

(57) [Abstract] [Purpose] Aim to make the structure simple and thin. [Structure] 3 is a yoke, 4 is a spacing block for holding the spacing between opposing yokes, 5 is a leaf spring, and 10 is a weight having a coil bobbin 11 around which a coil is wound. Then, a mounting portion 14 to which the leaf spring 5 is attached is provided on the end surface of the coil bobbin 11 in the swinging direction, and the leaf spring 5 has a weight 1
They are arranged to face each other within a swing locus of zero.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a servo acceleration sensor applied to detection of acceleration, inclination angle, etc. of automobiles, agricultural machines, construction work machines, etc., and particularly to a weight support structure.

[0002]

[Prior art]

 In general, a servo acceleration sensor of this type is known to be configured as shown in FIGS. 4 to 6. That is, FIG. 4 is a front view of the conventional servo acceleration sensor from which the front yoke is removed, FIG. 5 is a sectional view taken along line VV of FIG. 4, and FIG. 6 is a sectional view taken along line VI-VI of FIG. In these figures, 2 and 3 are a pair of flat plate-shaped yokes which are arranged to face each other, 4 is a spacing block which is attached to the upper ends of the yokes 2 and 3, and which maintains the spacing between the yokes 2 and 3, and has a length of It is formed in about half the width of the yokes 2, 3.

Reference numeral 5 denotes a pair of conductive leaf springs whose upper portions are cantilevered on both sides of the end surface of the spacing block 4 and to which a coil 12 described later is electrically connected, and 7 is fixed to the inner surface of one yoke 2. A magnet, 8 is a light emitting element fixed to the inner surface side of the yoke 2, and 9 is a light receiving element which is arranged facing the light emitting element 8 and fixed to the yoke 3 side. A weight, which is indicated by reference numeral 10 in its entirety, is composed of a coil bobbin 11 and a coil 12 wound around the coil bobbin 11. The coil bobbin 11 is provided with a slit 13 corresponding to the light emitting and light receiving elements 8 and 9, and a mounting portion 20 which is vertically provided outward in a substantially central portion of the outer surface. By attaching the mounting portion 20 to the lower free end of the leaf spring 5, the weight 10 is swingably supported in the arrow A direction between the yokes 2 and 3.

In such a configuration, a static magnetic field is applied to the coil 12 by the magnetic circuit including the magnets 7 and 7 and the yokes 2 and 3. When a current is passed through the coil 12, the weight 10 has a large current. Receives a force proportional to When acceleration α is applied to the weight 10, a force mα (m is a mass of the weight 10) and a restoring force −kx (k is a spring constant, x is a displacement of the weight) by the leaf spring 5 are applied to the weight 10. Will join. The displacement of the weight 10 due to the external force is detected by the optical system including the light emitting element 8, the slit 13, and the light receiving element 9, and a current is passed through the coil 12 so that the displacement x = 0. The acceleration is detected by utilizing the fact that this current value is proportional to the acceleration α.

[0005]

[Problems to be solved by the device]

 However, in the above-mentioned conventional servo acceleration sensor, the structure for supporting the weight 10 is arranged so that the leaf springs 5 and 5 are arranged on the same plane orthogonal to the swinging direction of the weight 10. However, the distance between the yokes 2 and 3 is at least the sum of the thickness of the weight 10 and the width of the two leaf springs 5, resulting in a large thickness as a whole. Further, since the gap between the yokes 2 and 3 is widened, the magnetic resistance of the magnetic circuit is increased, and in order to improve this, the yoke 3 must be provided with the protruding portion 3a, which has a drawback that the structure is complicated.

Therefore, the present invention has been made in view of the above-mentioned conventional drawbacks, and an object of the present invention is to provide a servo acceleration sensor having a simple structure and a thin structure.

[0007]

[Means for Solving the Problems]

 In order to achieve this object, the sensor in servo acceleration according to the present invention has a weight on which a coil is arranged, a pair of leaf springs for swingably supporting the weight, and a coil surface of the coil. A magnetic circuit that generates a magnetic flux in the vertical direction and a displacement detection unit that detects the amount of displacement of the weight, and the pair of leaf springs are arranged to face each other in the swing trajectory of the weight and support the weight. .

[0008]

[Action]

 According to the present invention, the installation position of the leaf spring is within the range of the thickness of the weight.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a servo acceleration sensor according to the present invention from which a front yoke is removed, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. In these figures, the same components as those in the conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted. In the present invention, the length of the spacing block 4 is formed to be substantially the same as the width of the yokes 2, 3. The coil bobbin 11 is provided with a pair of opposing mounting portions 14 that are formed by bending inwardly of the coil bobbin 11 at both ends in the swinging direction.

The upper parts of the pair of leaf springs 5 are attached to both end faces of the spacing block 4 so as to be cantilevered, and the lower free ends thereof are attached to the attachment portion 14. Since the leaf springs 5 thus mounted are arranged to face each other in the swing trajectory of the weight 10, the yokes 2 and 3 need not be arranged avoiding the leaf springs 5 attached. As a result, the distance between the yokes 2 and 3 can be narrowed and the overall thickness can be reduced. Further, since the gap between the yokes 2 and 3 is narrow, the magnetic resistance is low, and the yoke 3 may be in the shape of a flat plate, which simplifies the structure.

[0011]

[Effect of device]

 As described above, according to the present invention, a weight on which a coil is arranged, a pair of leaf springs that swingably supports the weight, and a magnetic flux is generated in a direction perpendicular to the coil surface of the coil. A pair of leaf springs are placed opposite to each other in the swing trajectory of the weight to support the weight, and the york is placed avoiding the leaf spring. Therefore, the distance between the yokes can be reduced, and the overall thickness can be reduced. Also, since the gap between the yokes is narrow, the magnetic resistance can be kept low while the yoke remains flat, and the structure is simple.

[Brief description of drawings]

FIG. 1 is a front view of a servo acceleration sensor according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a front view of a conventional servo acceleration sensor.

5 is a sectional view taken along line VV of FIG.

6 is a sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

 2, 3 yoke 5 leaf spring 7 magnet 8 light emitting element 9 light receiving element 10 weight 11 coil bobbin 12 coil 13 slit 14 mounting portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Katsumi Yokota, 1-4, Fujimi-cho, Gyoda-shi, Saitama Prefecture, Jeco Co., Ltd. (72) Hiroshi Iiyama, 1-4-1, Fujimi-cho, Gyoda, Saitama Prefecture, Jeco Within the corporation

Claims (1)

[Scope of utility model registration request] 1. A weight provided with a coil, a pair of leaf springs swingably supporting the weight, a magnetic circuit for generating a magnetic flux in a direction perpendicular to a coil surface of the coil, and a weight. A servo acceleration sensor, comprising: a displacement detecting means for detecting a displacement amount, wherein the pair of leaf springs are arranged to face each other within a swing locus of the weight and support the weight.