JPS61191969A - Acceleration detector - Google Patents

Abstract

PURPOSE:To achieve a smaller size, by placing a weight base tiltably according to acceleration to detect changes in the emitted light from a tilted surface of the weight base by a light detecting means. CONSTITUTION:A weight base 3a is placed tiltably in a container 1 according to acceleration and reflects light at the center portion of the top thereof 3a while is colored black so as not to reflect light. When acceleration exceeding a specified value is applied horizontally to the base 3a, the base 3a tilts turning. As with the tilting thereof, the point where the light emitted from a light emitting element 9 is incident shifts to the black part from the center portion of the top of the base 3a, no light is received with a light receiving element 10 nulifying the potential difference in a voltometer 21. The inner surface of the container 1 is so formed that the base 3a returns to the original position by own gravity with no acceleration applied. The use of such a truncated pyramid- shaped base 3a enables the checking to see if the acceleration exceeding a specified value is applied in a horizontal plane about a plurality of directions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an acceleration detection device used, for example, to control the suspension of an automobile.

[Conventional technology]

When a car is driving on a convex circuit or an oil road, and the car body is subjected to a certain amount of acceleration in the horizontal or vertical direction, the spring constant of the suspension is increased to reduce the shaking of the car body and improve ride comfort. Suspension control systems have been used in recent years. One of these components is an acceleration detector that detects whether an acceleration of a predetermined value or more is applied.

FIGS. 4 and 5 are cross-sectional views showing an acceleration detector that is already installed in a passenger car and used for the above purpose, for example. In the figure, (1) is a hollow cylindrical container with the bottom closed;
(2) is a universal joint that has a fulcrum that can swing in any direction in the horizontal plane by a groove provided in the upper part of the container (1). It is also possible to move. (3) is a weight attached to the lower part of the fulcrum of the universal joint (2) and acts as a pendulum; (4) is a push-up plate attached to the upper part of the fulcrum of the universal joint (2); Swinging member (3b)
has been fixed through. The weight (3) and the push-up plate (4) can swing in any direction within the horizontal plane and can move upward.

[5] is a body, (6) is a rod supported by the body (5) and can slide only in the vertical direction, and (7) is a presser plate.

(8) is an adjustment spring. The rod (6) receives the force of the adjustment spring (8) via the presser plate (7) to restrict the movement of the aforementioned push-up plate (4). The shape of the push-up plate (0) is determined so that the plate operates when the acceleration determined for each direction is exceeded. (8) is a light-emitting element such as a light-emitting diode, (
10) is a light-receiving element such as a phototransistor that is energized when receiving light, and these light-emitting element (3) and light-receiving element (10) are activated when the rod (6) is raised by the operation of the push-up plate (4). 8) and the light receiving element (10).

(11) is the positive power supply terminal, (12) is the lead wire, (13)
) is a resistor, (14) is a 7-node terminal of the light emitting element (8), and (15).

is the collector terminal of the light receiving element (10). The lead wire (12) connected to the positive power terminal (11) is connected to the resistor (1
3) through the 7 node terminal (14) of the light emitting element (9),
and is connected to the collector terminal (15) of the light receiving element (lO). Further, (16) is a negative power supply terminal, (17) is a lead wire, (18) is a cathode terminal of the light emitting element (8),
(19) is a resistor, (20) is an emitter terminal of the light receiving element (10), and (21) is a voltmeter. Negative power terminal (1
The lead wire (17) connected to the light emitting element (8)
is connected to the emitter terminal (20) of the light receiving element (lO) through the cathode terminal (1B) and the resistor (18). A voltmeter (21) is connected in parallel with a resistor (19).

Next, the operation will be explained. In the aforementioned acceleration sensor, the center of gravity and fulcrum of the weight (3) are always on the vertical line as shown in Figure 4, so the rod (6) is connected to the light emitting element (
9) and the light receiving element (10) are not blocked.

Therefore, since the light receiving element (lO) receives light from the light emitting element (9), the collector terminal (15) of the light receiving element (lO)
The voltages at the emitter terminal (20) and the emitter terminal (20) become approximately equal. Therefore, a potential difference occurs between both ends of the resistor (19), that is, across the voltmeter (21).

However, when an acceleration of more than a predetermined value is applied to the weight (3) in any direction within the horizontal plane, a force is generated that causes the weight (3) to rotate around the fulcrum due to inertial force.
Since this force overcomes the pressing force from above, the line connecting the fulcrum and the center of gravity of the weight (3) is tilted from the vertical line, as shown in Figure 5, and the push-up plate (4) is pushed up against the rod (
6), and as a result, the light emitting element (3) and the light receiving element (
The optical path between the two (1O) is blocked. Therefore, the light from the light-emitting element (3) no longer reaches the light-receiving element (lO), and the voltage between the collector terminal (15) and emitter terminal (20) of the light-receiving element (10) becomes approximately equal to the applied voltage. There is no potential difference between both ends of the voltage meter (18), that is, across the voltmeter (21). On the other hand, the push-up plate (4) is shaped so that the distance from the fulcrum to the end of the push-up plate is selected so that it operates with a predetermined acceleration in each direction, so that when the potential difference on the voltmeter (21) becomes zero, It is now possible to detect when an acceleration greater than a predetermined value is applied in each direction.

[Problem that the invention seeks to solve]

In the above-mentioned acceleration sensor, the fulcrum of the universal joint (2) supporting the weight (3), the contact area between the push-up plate (4) and the rod (6), the body (5) and the rod (6) ) Frictional force acts on each sliding part, and since the way the frictional force acts is not constant, there is a problem that the detected acceleration value varies considerably over time or from individual to individual. there were. Another problem is that even a slight change in the adjustment of the adjustment spring (8) causes a large change in the holding force against the rod (6), so setting the detected acceleration to a predetermined value is time consuming and prone to errors. There were also points.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide an acceleration detector that has a simpler structure and eliminates the effects of frictional force and spring force.

[Means for solving problems]

The acceleration detector according to the present invention allows the weight table to be tilted according to acceleration. The light detecting means detects a change in the light emitted from the tilted surface of the weight table.

[Effect]

In this invention, when an acceleration of a predetermined value or more is applied to the weight table in the horizontal direction, the weight table tilts while rotating around one side or one point of the bottom surface,
As a result, the light detection means detects the presence or absence of acceleration by detecting a change in the light emitted from the tilting surface of the weight table, so that the influence of frictional force on the detected acceleration is almost eliminated. Furthermore, since no spring is used, there is no variation in detected acceleration due to the influence of spring force.

〔Example〕

FIG. 1 is a sectional view showing an embodiment of the present invention. (
3a) is a truncated pyramid-shaped weight table placed so as to be tiltable according to acceleration, and in this embodiment, a truncated pyramid-shaped weight table will be described. (1) is a container whose inner bottom surface is slightly larger than the bottom surface of the weight table (3a) and whose shape limits the inclination angle of the weight table (3a); 3a) from springing upward, and the photodetector element (9);
This is a cover that also serves as a stay for attaching (10). (9) and (10) are photodetecting elements constituting the photodetecting means; in this example, (9) is a light emitting element;
) uses a light receiving element. Reference numerals (11) to 21) represent voltage conversion means constituting the photodetection means, which are the same as those in the conventional device described above. In this example, the light emitting element (9
) and the light-receiving element (10), and at normal times, the center of the upper surface (the surface with larger area in the figure) of the tilted surfaces (upper surface, lower surface, and side surfaces) of the weight table (3a) is used. It is set up so that the light is reflected. These (8)
A change in reflected light, which is light emitted from the tilted surface of the weight table (3a), is detected by the light detection means constituted by (21) to (21).

As shown in FIG. 3, the upper surface of the weight table (3a) is designed so that light is reflected at the center part, and other parts are colored, for example, black to prevent light from being reflected. However,
When the weight table (3a) is tilted, the point of incidence of light shifts from the central portion to the black portion. Note that since the path of the emitted light changes when the weight table (3a) is tilted, the upper surface of the weight table (3a) does not need to be partially colored.

In the acceleration detector configured as above, the weight table (3a) is normally placed in the container (1) as shown in FIG.
The container (1) and the weight table (3a) are placed inside the container (1) and the weight table (3a).
It is stable because the bottom surfaces (the surfaces with smaller area) are in contact with each other. At this time, the light emitted from the light emitting element (9) hits the center part of the upper surface of the weight table (3a), is reflected, becomes reflected light that is the light emitted from the weight table (3a), and is received. Since the light is incident on the element (10), a potential difference occurs between both ends of the voltmeter (21) as explained in the example of the conventional device.

However, as shown in Fig. 2, when an acceleration of more than a predetermined value is applied to the weight table (3a) in the horizontal direction, one side of the bottom (3a)
In Fig. 2, the weight table (3a) rotates and tilts around point A). During this troublesome process, the light emitted from the light emitting element (9) enters the weight table (3a).
3a) To move from the center part to the black part of the upper surface,
No light is received by the light receiving element (10), and there is no potential difference between both ends of the voltmeter (21).

Next, the inner shape of the container (1) is adjusted so that the inclination of the weight stand (3a) is adjusted so that when the horizontal acceleration disappears, the weight stand (3a) returns to its original position by the moment due to its own weight with respect to the center of rotation (A). If the shape is such that the angle is restricted, there is no need to apply restoring force to the weight stand (3a) from the outside.By using the principle of 0 or more, the weight stand (3a) in the shape of a truncated pyramid can be used to It is possible to detect whether an acceleration of a predetermined value or more is applied in multiple directions within the truncated area.In this embodiment, as shown in Figs. As a weight table, it is possible to detect the presence or absence of acceleration exceeding a predetermined value in two directions perpendicular to each other in a horizontal plane.Incidentally, if a truncated cone shape or a truncated elliptical shape is used as the weight table (3a), , it is possible to detect whether an acceleration of a predetermined value or more is applied not only to two mutually orthogonal directions (components) in the horizontal plane but also to any direction in the horizontal plane.Also, the shape of the weight table (3a) is not limited to the shape of a truncated pyramid, but may be a cylinder, a prism, etc., as long as it is tilted at a certain angle and can be restored.Also, the height of the center of gravity of the weight table (3a) and the distance to the center of rotation are By appropriately changing the ratio to the arm length, the value of acceleration to be detected can be changed.

Furthermore, in the above embodiment, the light-emitting element (9) and the light-receiving element (10), which are photo-detecting elements, were considered as separate elements.
A combination of these two may also be used.

Also, the photodetector is a weight stand (3a) instead of a reflective type.
It may also be a method of detecting transmitted light or refracted light that has passed through the interior. In this case, the weight stand (3a) needs to be made of a material that transmits light (eg, glass, plastic, etc.).

Furthermore, in the above embodiment, the detection result by the photodetector is taken out as a change in voltage, but instead of a change in voltage,
It may also be taken out as a change in current.

Further, as shown in FIG. 3, in this embodiment, the upper surface of the weight table (3a) is partially colored black, but the first color is not limited to black, and may be any color.

Furthermore, the inclined surface of the weight table (3d) through which light is incident is not limited to the top surface, but may be either the side surface or the bottom surface.

In addition, in the above embodiment, the case where it is used for the suspension control of an automobile was explained, but it can also be used for the operation or anti-vibration control of other vehicles such as railway cars and aircraft, or escalators and elevators. , the same effect as the above embodiment is achieved.

〔Effect of the invention〕

As explained above, the present invention includes a weight table mounted so as to be tiltable according to acceleration, and changes in the light emitted from the tilting surface of the weight table when acceleration of a predetermined value or more is applied in the horizontal direction. Since it has a simple configuration in which detection is performed using a detection means, the effects of frictional force and spring force are eliminated, and there is no need to apply restoring force using springs, etc., making it possible to obtain a highly accurate, compact, and inexpensive product. effective.

[Brief explanation of drawings]

1 and 2 are cross-sectional side views showing an acceleration detector according to an embodiment of the present invention, and FIG. 3 is a plane view showing the upper surface of the weight table (3a) in FIGS. 1 and 2. 4 and 5 are cross-sectional side views showing conventional acceleration detectors. (1)... Container, (3a)... Weight stand. (ll), (10)...photodetection element, (11) or 21)...voltage conversion means. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 4 Figure 5 Figure 3

Claims (6)

[Claims] (1) An acceleration detector characterized by comprising a weight table mounted so as to be tiltable according to acceleration, and a light detection means for detecting a change in light emitted from the tilting surface of the weight table. (2) The acceleration detector according to claim 1, wherein the weight pedestal has a truncated cone shape. (3) The acceleration detector according to claim 2, wherein the weight pedestal has a truncated pyramid shape. (4) Any one of claims 1 to 3, characterized in that the weight table is housed in a container having an inner surface shape that limits the inclination angle of the weight table to a predetermined value or less. Acceleration detector described in Crab. (5) The light detection means is constituted by a reflective light detection element that detects a change in the light reflected from the top surface of the weight table, and a voltage conversion means that converts the detection result into a change in voltage. An acceleration detector according to any one of claims 1 to 4. (6) The light detection means is constituted by a reflective light detection element that detects a change in the light reflected from the top surface of the weight table, and a current conversion means that converts the detection result into a change in current. An acceleration detector according to any one of claims 1 to 4.