JPS59128408A - Slant angle sensor - Google Patents

Abstract

PURPOSE:To make a slant angle output large and to expand its linear region, by fixing and holding one of Hall elements between a pair of permanent magnets, elastically supporting the other at a fixing part, and changing the relative positions of both elements in response to the slant. CONSTITUTION:Hall element 11 are mounted on a supporting table 14, which is fixed to a base 13. The Hall elements 11 are positioned between a pair of permanent magnets 10a and 10b, which are embedded in both sides of a weight 3 that is elastically supported by a plate spring 4 on the table 14. With the elements 11 being located in between the magnets 10a and 10b in response to the slant, the relative positions between the magnets 10a and 10b and the elements 11 are changed, and the detected voltage is outputted from the elements 11 in response to the slant. Based on the relative position change between the permanent magnets and the Hall elements under the positional state in between the pair of the permanent magnets, the outputs of the Hall elements become large, the linear regions are expanded, resolution is improved, the effect on the outputs due to dispersion in characteristics is decreased, and the structure can be simplified. When the Hall elements are elastically supported, the same result is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inclination angle sensor for detecting the inclination of an object, and more particularly to an inclination angle sensor in which the mounting of its detection element is characterized by its structure.

Prior Art and its Problems Among the conventional tilt angle sensors that use Hall elements as detection elements, one using two Hall elements is known. 1st
The figure shows an example of such a tilt angle sensor, in which Hall elements 2a and 2b driven by a constant current source are provided at symmetrical positions on the inner wall of a housing 1. Inside the housing 1, a weight 3 is suspended and held by a leaf spring 4, and on the left and right sides of the weight 3, permanent magnets 5a and jb are connected to Hall elements 2a and 2.
b. Here, this inclination angle sensor is tilted left and right on the paper (and the weight 3 is tilted in the direction of arrow A according to the tilt angle, and the Hall element 2a is tilted.

The distance between Hall elements 2b and permanent magnets 5a and 5b changes, and the magnetic flux density passing through Hall elements 2a and 2b changes.

Therefore, the voltage output obtained from the ball elements 2a and 2b is as shown in FIG. So, if we take the sum of this output, we get
As shown by the straight line 6 in FIG. 2, an output signal proportional to the tilt angle is obtained. 'However, in such a conventional tilt angle sensor, it is necessary to make the distance between the Hall element and the permanent magnet sufficiently close, otherwise there is a drawback that a sufficient output due to the tilt cannot be obtained. Also, the linear region is narrow (,
There was a problem with low resolution. In addition, two Hall elements are required and the configuration of the output circuit becomes complicated in order to eliminate mutual influence, and if there are variations in characteristics between Hall elements, the symmetry from the horizontal position will be lost, so each device It was necessary to check and correct the output value each time.

Purpose of the Invention The present invention solves these conventional problems by increasing the output of the tilt angle, expanding its linear region and improving the resolution, and by reducing the number of ball elements to one. It is an object of the present invention to provide an inclination angle sensor that can eliminate the influence on output due to variations in characteristics and can simplify the configuration of an output circuit.

Structure and Effects of the Invention The present invention is an inclination angle sensor that detects inclination based on an output obtained from a Hall element placed in a magnetic field, which includes at least one pair of permanent magnets and a pair of permanent magnets when held in a horizontal position. A Hall element placed in the center position between
holding means for holding one of the pair of permanent magnets and the Hall element on a fixed part, and holding the other on the fixed part via an elastic member, and the holding means holds one of the pair of permanent magnets and the Hall element on the fixed part through an elastic member. It is characterized in that the relative position with respect to the Hall element changes.

In the inclination angle sensor of the present invention having such characteristics, since the output voltage obtained from the Hall element is large, the sensitivity is good, the linear region is expanded, and the resolution is also improved. Furthermore, since only one Hall element is used, there is no need to consider variations in the characteristics of the Hall element, and the circuit configuration for receiving the output of the Hall element is also much simpler than that of the conventional one. Furthermore, it is not necessary to strictly adjust the distance between the Hall element and the permanent magnet, D, which facilitates adjustment work during manufacturing.

DESCRIPTION OF EMBODIMENTS FIGS. 3(a) and 3(Tb) are cross-sectional views taken in different vertical planes showing an embodiment of the inclination angle sensor according to the present invention, and the same parts as in the conventional example are designated by the same reference numerals. It is shown using Further, FIG. 4 is a diagram showing the relative positional relationship between the Hall element and the permanent magnet in this embodiment. In these figures, permanent magnets 10a and 10b are arranged to sandwich the Hall element 11. That is, as shown in FIG. 3, the weight 3 is provided with a cutout 3a at the lower center thereof, and permanent magnets IQa and lOb are embedded on the left and right sides of the cutout 3a. On the other hand, the cover 1 is divided into a lower sensor section and an upper detection circuit section by an inner M12, and a base 1 is provided below the inner cover 12.
3 is provided with a U-shaped Hall element support substrate 14 as shown in FIG. In the center of the support substrate 14, the Hall element 11 is connected to the permanent magnet 1 (la, 10b) of the weight 3.
is held facing the The Hall element 11 is driven by a constant current source (not shown), and the voltage across it is extracted via an amplifier. In this way, in the output circuit of this embodiment, unlike the conventional example, there is no need to combine the outputs of two ball elements, so the structure of the output circuit is simplified.

Next, the operation of this tilt angle sensor will be explained.

The broken lines in FIG. 4 indicate lines of magnetic force caused by the permanent magnets 10a and 10b, and since the magnetic flux density penetrating the Hall element 11 shown by the solid line is zero at the position shown, no output voltage can be obtained from the Hall element. However, when the inclination angle sensor is tilted, the leaf spring 4 is bent by the gravity applied to the weight 3 in accordance with the angle of inclination. Therefore, the permanent magnets 10a, 1
The relative position between 0b and the Hall element 11 will change. Now, when the tilt angle sensor tilts in the direction not shown by arrow B in FIG. 3 (bl) and the weight 3 swings, the permanent magnet 10a.

10b moves in the direction of arrow B in FIG.
The relative position with the Therefore, the magnetic flux density passing through the Hall element 11 changes depending on the inclination angle of the inclination angle sensor, and an output voltage corresponding to the inclination angle is obtained from the Hall element 11. Assuming that the Hall element 11 has come to the position shown by the broken line in FIG. 4 due to this change in relative positional relationship,
The magnetic flux density passing through the Hall element 11 becomes maximum, and the output voltage obtained from the Hall element 11 also becomes maximum. Furthermore, when the tilt angle sensor is tilted in the opposite direction, the direction of the magnetic field lines passing through the Hall element 11 is reversed, and the output voltage is also of the opposite sign. Therefore, the change in the output voltage obtained from the Hall element 11 with respect to the inclination angle θ is as shown in FIG. Therefore, in the region shown by the broken line in the center, a substantially linear relationship is obtained between the inclination of the inclination angle sensor and the output.

This linear region is wider than that of conventional tilt angle sensors.

Since the tilt angle sensor of the present invention uses only one Hall element, there is no need to consider variations in the characteristics of the Hall element, and the circuit configuration that receives the output of the Hall element is also significantly larger than that of conventional ones. becomes easy. Furthermore, there is no need to strictly adjust the distance between the Hall element and the permanent magnet, making adjustment work easier during manufacturing. Furthermore, since the output voltage obtained from the Hall element is large, the sensitivity is good and the resolution is also improved. FIG. 6 shows another embodiment of the present invention.

In this figure, four permanent magnets 15a, 15b and 15a, 16b are provided around the Hall element 11. The permanent magnets 15a, 15b and the permanent magnets 16a, 16b are integrally formed by a holding member 17, and are assumed to be displaced in the left-right direction on the plane of the paper due to inclination, as in the previous embodiment. Even with this configuration, the magnetic flux density passing through the Hall element 11 changes in the same way due to changes in the relative positions of the Hall element 11 and the permanent magnets 15a, 15b, 16a, 16b, and the output characteristics are as described above. As in the embodiment, an output proportional to the tilt angle is output f44.

In these examples, the Hall element is fixed to the support substrate, and the permanent magnet embedded in the weight is moved relative to the Hall element to change its relative position. A similar effect can be obtained even if the Hall element is fixed and moved according to the inclination.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the configuration of a conventional tilt angle sensor;
The figure is a graph showing the output characteristics, Figure 3 (a), (b
1 is a sectional view showing the structure of the inclination angle sensor according to the present invention, FIG. 4 is a diagram showing the positional relationship between the Hall element and the permanent magnet, FIG. 5 is a graph showing its output characteristics, and FIG. It is a figure showing the positional relationship of the Hall element and the permanent magnet of an example. 1-1---Housing 2 a, 2 b, 11
-----Hall element 3-1---Weight 4---
- Single leaf spring 5a, 5b, 10a, 10b15a, 1
5b----Permanent magnet patent applicant Tateishi Electric Co., Ltd. agent Patent attorney Yoshiki Okamoto (1 person) Figure 1 Figure 2 Figure 3 (3), 5108.3814 former 101) Figure 3 ( b)

Claims (1)

[Claims] (1) In a tilt angle sensor that detects tilt based on the output obtained from a Hall element placed in a magnetic field, at least one permanent magnet and a central position between the pair of permanent magnets when held in a horizontal position. holding means for holding one of the pair of permanent magnet and Hall element on a fixed part and holding the other on the fixed part via an elastic member, f, characterized in that the relative position of the pair of permanent magnets and the Hall element changes according to
Around bevel angle sensor.